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Agroinfiltration is a method used in plant biology and especially lately in plant biotechnology to induce transient expression of genes in a plant, or isolated leaves from a plant, or even in cultures of plant cells, in order to produce a desired protein. In the method, a suspension of Agrobacterium tumefaciens is introduced into a plant leaf by direct injection or by vacuum infiltration, or brought into association with plant cells immobilised on a porous support (plant cell packs), whereafter the bacteria transfer the desired gene into the plant cells via transfer of T-DNA. The main benefit of agroinfiltration when compared to the more traditional plant transformation is speed and convenience, although yields of the recombinant protein are generally also higher and more consistent.
The first step is to introduce a gene of interest to a strain of Agrobacterium tumefaciens. Subsequently, the strain is grown in a liquid culture and the resulting bacteria are washed and suspended into a suitable buffer solution. For injection, this solution is then placed in a syringe (without a needle). The tip of the syringe is pressed against the underside of a leaf while simultaneously applying gentle counterpressure to the other side of the leaf. The Agrobacterium suspension is then injected into the airspaces inside the leaf through stomata, or sometimes through a tiny incision made to the underside of the leaf.
Vacuum infiltration is another way to introduce Agrobacterium deep into plant tissue. In this procedure, leaf disks, leaves, or whole plants are submerged in a beaker containing the solution, and the beaker is placed in a vacuum chamber. The vacuum is then applied, forcing air out of the intercellular spaces within the leaves via the stomata. When the vacuum is released, the pressure difference forces the "Agrobacterium" suspension into the leaves through the stomata into the mesophyll tissue. This can result in nearly all of the cells in any given leaf being in contact with the bacteria.
Once inside the leaf the Agrobacterium remains in the intercellular space and transfers the gene of interest as part of the Ti plasmid-derived T-DNA in high copy numbers into the plant cells. The gene transfer occurs when the plant signals are induced and physical contact is made between the plant cells and the bacteria. The bacteria create a mechanism that burrows a hole and transfers the new T-DNA strand into the plant cell. The T-DNA moves into the nucleus of the plant and begins to integrate into the plants chromosome. The gene is then transiently expressed through RNA synthesis from appropriate promoter sequences in all transfected cells (no selection for stable integration is performed). The plant can be monitored for a possible effect in the phenotype, subjected to experimental conditions or harvested and used for purification of the protein of interest. Many plant species can be processed using this method, but the most common ones are Nicotiana benthamiana and less often, Nicotiana tabacum'.
Transient expression in cultured plant cell packs is a new procedure, recently patented by the Fraunhofer Institute IVV, Germany. For this technique, suspension cultured cells of tobacco (e.g.: NT1 or BY2 cell lines of Nicotiana tabacum) are immobilised by filtration onto a porous support to form a well-aerated cell pack, then incubated with recombinant Agrobacterium for a time to allow T-DNA transfer, before refiltration to remove excess bacteria and liquid. Incubation of the cell pack in a humid environment for time periods up to several days allows transient expression of protein. Secreted proteins can be washed out of the cell pack by application of buffer and further filtration. | 1 | Gene expression + Signal Transduction |
To produce a ton of steel in an electric arc furnace requires approximately 400 kilowatt-hours (1.44 gigajoules) per short ton or about 440 kWh (1.6 GJ) per tonne. The theoretical minimum amount of energy required to melt a tonne of scrap steel is 300 kWh (1.09 GJ) (melting point ). Therefore, a 300-tonne, 300 MVA EAF will require approximately 132 MWh of energy to melt the steel, and a "power-on time" (the time that steel is being melted with an arc) of approximately 37 minutes.
Electric arc steelmaking is only economical where there is plentiful, reliable electricity, with a well-developed electrical grid. In many locations, mills operate during off-peak hours when utilities have surplus power generating capacity and the price of electricity is less. This compares very favourably with energy consumption of global steel production by all methods estimated at some 5,555 kWh (20 GJ) per tonne (1 gigajoule is equal to approximately 270 kWh). | 0 | Metallurgy |
PT clearly plays a central role in the pathogenesis of pertussis although this was discovered only in the early 1980s. The appearance of pertussis is quite recent, compared with other epidemic infectious diseases. The earliest mention of pertussis, or whooping cough, is of an outbreak in Paris in 1414. This was published in Moultons The Mirror of Health, in 1640. Another epidemic of pertussis took place in Paris in 1578 and was described by a contemporary observer, Guillaume de Baillou. Pertussis was well known throughout Europe by the middle of the 18th century. Jules Bordet and Octave Gengou described in 1900 the finding of a new “ovoid bacillus” in the sputum of a 6-month-old infant with whooping cough. They were also the first to cultivate Bordetella pertussis' at the Pasteur Institute in Brussels in 1906.
One difference between the different species of Bordetella is that B. pertussis produces PT and the other species do not. Bordetella parapertussis shows the most similarity to B. pertussis and was therefore used for research determining the role of PT in causing the typical symptoms of whooping cough. Rat studies showed the development of paroxysmal coughing, a characteristic for whooping cough, occurred in rats infected with B. pertussis. Rats infected with B. parapertussis or a PT-deficient mutant of B. pertussis did not show this symptom; neither of these two strains produced PT. | 1 | Gene expression + Signal Transduction |
Corepressors are known to regulate transcription through different activation and inactivation states.
NCoR and SMRT act as a corepressor complex to regulate transcription by becoming activated once the ligand is bound. Knockouts of NCoR resulted in embryo death, indicating its importance in erythrocytic, thymic, and neural system development.
Mutations in certain corepressors can result in deregulation of signals. SMRT contributes to cardiac muscle development, with knockouts of the complex resulting in less developed muscle and improper development.
NCoR has also been found to be an important checkpoint in processes such as inflammation and macrophage activation.
Recent evidence also suggests the role of corepressor RIP140 in metabolic regulation of energy homeostasis. | 1 | Gene expression + Signal Transduction |
While repeatedly reversed loading commonly leads to localisation of dislocation glide, creating linear extrusions and intrusions on a free surface, similar features can arise even if there is no load reversal. These arise from dislocations gliding on a particular slip plane, in a particular slip direction (within a single grain), under an external load. Steps can be created on the free surface as a consequence of the tendency for dislocations to follow one another along a glide path, of which there may be several in parallel with each other in the grain concerned. Prior passage of dislocations apparently makes glide easier for subsequent ones, and the effect may also be associated with dislocation sources, such as a Frank-Read source, acting in particular planes.
The appearance of such bands, which are sometimes termed “persistent slip lines”, is similar to that of those arising from cyclic loading, but the resultant steps are usually more localised and have lower heights. They also reveal the grain structure. They can often be seen on free surfaces that were polished before the deformation took place. For example, the figure shows micrographs (taken with different magnifications) of the region around an indent created in a copper sample with a spherical indenter. The parallel lines within individual grains are each the result of several hundred dislocations of the same type reaching the free surface, creating steps with a height of the order of a few microns. If a single slip system was operational within a grain, then there is just one set of lines, but it is common for more than one system to be activated within a grain (particularly when the strain is relatively high), leading to two or more sets of parallel lines. Other features indicative of the details of how the plastic deformation took place, such as a region of cooperative shear caused by deformation twinning, can also sometimes be seen on such surfaces. In the optical micrograph shown, there is also evidence of grain rotations – for example, at the “rim” of the indent and in the form of depressions at grain boundaries. Such images can thus be very informative. | 0 | Metallurgy |
The old MIL-F-14256 and QQ-S-571 standards defined fluxes as:
*R (rosin)
*RMA (rosin mildly activated)
*RA (rosin activated)
*WS (water-soluble)
Any of these categories may be no-clean, or not, depending on the chemistry selected and the standard that the manufacturer requires. | 0 | Metallurgy |
When an initially homogenous alloy is placed in an acid that can preferentially dissolve one or more components out of the alloy, the remaining component will diffuse and organize into a unique, nano-porous microstructure. The resulting material will have ligaments, formed by the remaining material, surrounded by pores, empty space from which atoms were leached/diffused away. | 0 | Metallurgy |
Masahiro Ishiura, Takao Kondo, Susan S. Golden, Carl H. Johnson, and their colleagues discovered the gene cluster in 1998 and named the gene cluster kaiABC, as "kai" means “cycle” in Japanese. They generated 19 different clock mutants that were mapped to kaiA, kaiB, and kaiC genes, and successfully cloned the gene cluster in the cyanobacteria Synechococcus elongatus. Using a bacterial luciferase reporter to monitor the expression of clock-controlled gene psbAI in Synechococcus, they investigated and reported on the rescue to normal rhythmicity of long-period clock mutant C44a (with a period of 44 hours) by kaiABC. They inserted wild-type DNA through a pNIBB7942 plasmid vector into the C44a mutant, and generated clones that restored normal period (a period of 25 hours). They were eventually able to localize the gene region causing this rescue, and observed circadian rhythmicity in upstream promotor activity of kaiA and kaiB, as well as in the expression of kaiA and kaiBC messenger RNA. They determined abolishing any of the three kai genes would cause arrhythmicity in the circadian clock and reduce kaiBC promoter activity. KaiC was later found to have both autokinase and autophosphatase activity. These findings suggested that circadian rhythm was controlled by a TTFL mechanism, which is consistent with other known biological clocks.
In 2000, S. elongatus was observed in constant dark (DD) and constant light (LL). In DD, transcription and translation halted due to the absence of light but the circadian mechanism showed no significant phase shift after transitioning to constant light. In 2005, after closer examination of the KaiABC protein interactions, the phosphorylation of KaiC proved to oscillate with daily rhythms in the absence of light. In addition to the TTFL model, the PTO model was hypothesized for the KaiABC phosphorylation cycle.
Also in 2005, Nakajima et al. lysed S. elongatus and isolated KaiABC proteins. In test tubes containing only KaiABC proteins and ATP, in vitro phosphorylation of KaiC oscillated with a near 24 hour period with a slightly smaller amplitude than in vivo oscillation, proving that the KaiABC proteins are sufficient for circadian rhythm solely in the presence of ATP. Combined with the TTFL model, KaiABC as a circadian PTO was shown to be the fundamental clock regulator in S. elongatus | 1 | Gene expression + Signal Transduction |
While tribocorrosion phenomena may affect many materials, they are most critical for metals, especially the normally corrosion resistant so-called passive metals. The vast majority of corrosion resistant metals and alloys used in engineering (stainless steels, titanium, aluminium etc.) fall into this category. These metals are thermodynamically unstable in the presence of oxygen or water, and they derive their corrosion resistance from the presence at the surface of a thin oxide film, called the passive film, which acts as a protective barrier between the metal and its environment. Passive films are usually just a few atomic layers thick. Nevertheless, they can provide excellent corrosion protection because if damaged accidentally they spontaneously self-heal by metal oxidation. However, when a metal surface is subjected to severe rubbing or to a stream of impacting particles the passive film damage becomes continuous and extensive. The self-healing process may no longer be effective and in addition it requires a high rate of metal oxidation. In other words, the underlying metal will strongly corrode before the protective passive film is reformed, if at all. In such a case, the total material loss due to tribocorrosion will be much higher than the sum of wear and corrosion one would measure in experiments with the same metal where only wear or only corrosion takes place. The example illustrates the fact that the rate of tribocorrosion is not simply the addition of the rate of wear and the rate of corrosion but it is strongly affected by synergistic and antagonistic effects between mechanical and chemical mechanisms. To study such effects in the laboratory, one most often uses mechanical wear testing rigs which are equipped with an electrochemical cell. This permits one to control independently the mechanical and chemical parameters. For example, by imposing a given potential to the rubbing metal one can simulate the oxidation potential of the environment and in addition, under certain conditions, the current flow is a measure of the instantaneous corrosion rate. Volume loss due to electrochemical dissolution can be measured by Faraday's laws of electrolysis and subtracted from total volume loss in tribocorrosion so the sum of mechanical wear loss and the synergies can be calculated. For a deeper understanding tribocorrosion experiments are supplemented by detailed microscopic and analytical studies of the contacting surfaces.
At high temperatures, the more rapid generation of oxide due to a combination of temperature and tribological action during sliding wear can generate potentially wear resistant oxide layers known as glazes. Under such circumstances, tribocorrosion can be used potentially in a beneficial way. | 0 | Metallurgy |
The FSP is used when metals properties want to be improved using other metals for support and improvement of the first. This is promising process for the automotive and aerospace industries where new material will need to be developed to improve resistance to wear, creep, and fatigue. (Misha) Examples of materials successfully processed using the friction stir technique include AA 2519, AA 5083 and AA 7075 aluminum alloys, AZ61 magnesium alloy, nickel-aluminium bronze and 304L stainless steel. | 0 | Metallurgy |
In 1982, Koiti Titanis lab identified an "N-terminal blocking group" on the catalytic subunit of cyclic AMP-dependent protein kinase in cows as n-tetradecanoyl. Almost simultaneously in Claude B. Klees lab, this same N-terminal blocking group was further characterized as myristic acid. Both labs made this discovery utilizing similar techniques: mass spectrometry and gas chromatography. | 1 | Gene expression + Signal Transduction |
Like its counterpart, RB-E2F, the DREAM complex is also affected by similar growth stimuli and subsequent cyclin-CDK activity. Increasing cyclin D-CDK4 and cyclin E-CDK2 activity dissociates the DREAM complex from the promoter by phosphorylation of p130. Hyper-phosphorylated p130 is subsequently degraded and E2F4 exported from the nucleus. Once the repressive E2Fs are vacated, activating E2Fs bind to the promoter to up-regulate G1/S genes that promote DNA synthesis and transition of the cell cycle. BMYB is also up-regulated during this time, which then binds to genes that peak at G2/M phase. Binding of BMYB to late cell cycle genes is dependent on its association with the MuvB core to form the BMYB-MuvB complex, which is then able to up-regulate genes in the G2/M phase. | 1 | Gene expression + Signal Transduction |
Sinter plants agglomerate iron ore fines (dust) with other fine materials at high temperature, to create a product that can be used in a blast furnace. The final product, a sinter, is a small, irregular nodule of iron mixed with small amounts of other minerals. The process, called sintering, causes the constituent materials to fuse to make a single porous mass with little change in the chemical properties of the ingredients. The purpose of sinter are to be used converting iron into steel.
Sinter plants, in combination with blast furnaces, are also used in non-ferrous smelting. About 70% of the world's primary lead production is still produced using the sinter plant–blast furnace combination, and this combination was formerly often used in copper smelting (at the Electrolytic Refining and Smelting smelter in Wollongong, New South Wales, for example). | 0 | Metallurgy |
The repressor is an allosteric protein, i.e. it can assume either one of two slightly different shapes, which are in equilibrium with each other. In one form the repressor will bind to the operator DNA with high specificity, and in the other form it has lost its specificity. According to the classical model of induction, binding of the inducer, either allolactose or IPTG, to the repressor affects the distribution of repressor between the two shapes. Thus, repressor with inducer bound is stabilized in the non-DNA-binding conformation. However, this simple model cannot be the whole story, because repressor is bound quite stably to DNA, yet it is released rapidly by addition of inducer. Therefore, it seems clear that an inducer can also bind to the repressor when the repressor is already bound to DNA. It is still not entirely known what the exact mechanism of binding is. | 1 | Gene expression + Signal Transduction |
NUT carcinoma is a rare, highly aggressive malignancy. Initially, it was regarded as occurring in the midline areas of the upper respiratory tract, upper digestive tract, and mediastinum (i.e. central compartment of the thoracic cavity) of young adults and to lesser extents children and infants. It was therefore termed NUT midline granuloma. However, subsequent studies defined these carcinomas based on the presence of a NUT fusion gene in their malignant cells. As so defined, this malignancy occurs in individuals of all ages and, while most commonly developing in the cited respiratory, gastrointestinal, and mediastinal areas, occasionally develops in the salivary glands, pancreas, urinary bladder, retroperitoneum (i.e. space behind the peritoneum of the abdominal cavity), endometrium, kidneys, ovaries, and other organs. Consequently, the name of this disorder was changed form NUT midline carcinoma to NUT carcinoma by the World Health Organization, 2015. NUT carcinomas are characterized histologically as tumors containing
primitive epithelioid cells (i.e. derived from activated macrophages and resembling epithelial cells) admixed with foci of keratinization (i.e. tissue areas that are rich in keratin fibers); NUT carcinomas are considered variants of squamous cell carcinomas. Studies have found that ~66 tp 80% of NUT carcinomas harbor a BRD4-NUTM1 fusion gene while the remaining NUT carcinomas, sometimes termed NUT variant carcinomas, involve the BRD3-NUTM1 (~10 to 25% of cases) or, rarely, the NSD3-NUTM1, ZNF532-NUTM1,, or ZNF592-NUTM1 fusion gene. It is thought that the latter fusions genes promote NUT carcinomas in manners at least somewhat similar to the BRD4-NUTM1 fusion gene. | 1 | Gene expression + Signal Transduction |
Wire arc spray is a form of thermal spraying where two consumable metal wires are fed independently into the spray gun. These wires are then charged and an arc is generated between them. The heat from this arc melts the incoming wire, which is then entrained in an air jet from the gun. This entrained molten feedstock is then deposited onto a substrate with the help of compressed air. This process is commonly used for metallic, heavy coatings. | 0 | Metallurgy |
miRNA-324-5p is a relatively new and understudied microRNA. It is an important regulator in several diseases, and its effects span across the body from neuronal dysregulation in seizure to hepatocellular carcinoma and cardiac disease. Because microRNAs have numerous targets, they are capable of regulating multiple pathways and circuits, an ability that may be useful in the treatment of complex disorders like epilepsy in which many subsystems are dysregulated. However, the wide-ranging functions of miRNAs may be limiting as well. microRNA expression modulation could lead to unanticipated physiological effects and not provide adequate specificity. | 1 | Gene expression + Signal Transduction |
* Railway - gearboxes, wheels, transmissions
* Machine tools - lathe gearboxes, mills
* Steel works - roll bearings, roll neck rings
* Power generation - various generator components
Due to the need to insert a core and also that to be effective, the core has to be in relatively close proximity to the bore of the part to be heated, there are many application in which the above bearing heater type approach is not feasible. | 0 | Metallurgy |
The role of the activators is primarily disruption and removal of the oxide layer on the metal surface (and also the molten solder), to facilitate direct contact between the molten solder and metal. The reaction product is usually soluble or at least dispersible in the molten vehicle. The activators are usually either acids, or compounds that release acids at elevated temperature.
The general reaction of oxide removal is:
:Metal oxide + Acid → Salt + Water
Salts are ionic in nature and can cause problems from metallic leaching or dendrite growth, with possible product failure. In some cases, particularly in high-reliability applications, flux residues must be removed.
The activity of the activator generally increases with temperature, up to a certain value where activity ceases, either due to thermal decomposition or excessive volatilization. However the oxidation rate of the metals also increases with temperature.
At high temperatures, copper oxide reacts with hydrogen chloride to water-soluble and mechanically weak copper chloride, and with rosin to salts of copper and abietic acid which is soluble in molten rosin.
Some activators may also contain metal ions, capable of exchange reaction with the underlying metal; such fluxes aid soldering by chemically depositing a thin layer of easier solderable metal on the exposed base metal. An example is the group of fluxes containing zinc, tin or cadmium compounds, usually chlorides, sometimes fluorides or fluoroborates. | 0 | Metallurgy |
The meteorite fell to Earth after the retreat of glaciers from the area. All fragments recovered were found at the surface, partly buried, some on unstable terrain. The largest fragment was recovered in an area where the landscape consists of "flowing" gravel or clay-like sediments on permafrost, indicating that it had been in place for no more than a few thousand years. Other estimates have put the date of the fall as 10,000 years ago.
The iron masses were known to Inuit as Saviksoah (Great Iron, later renamed Ahnighito by Robert Edwin Peary) weighing ; the Woman, weighing ; and the Dog, weighing . For centuries, Inuit living near the meteorites used them as a source of metal for tools and harpoons. The Inuit would work the metal using cold forging—that is, by hammering the metal with stones. Excavations of a Norse farm in 1976 located an arrowhead made of iron from the meteorite, dating from the 11th to 14th century AD; its presence is evidence of Norse journeys to northern Greenland. Other pieces of Cape York meteoritic iron dating prior to 1450 (i.e. before the Little Ice Age) have been found throughout the Arctic Archipelago and on the North American mainland, and are evidence of an extensive Thule culture trade network which supplied iron to First Nations peoples prior to European contact.
In 1818, the British First Ross Expedition (led by Captain John Ross) made contact with Inuit on the northern shore of Melville Bay, who stated they had settled in the area to exploit a nearby source of iron. The Inuit described the location of this iron, but poor weather and sea ice prevented Ross from investigating further. Ross correctly surmised that the large iron rocks described by the Inuit were meteorites, and purchased several tools with blades made of the meteoritic iron.
Between 1818 and 1883, five further expeditions to the area were mounted by Britain, Sweden, and Denmark, which all failed to find the source of the iron. Only in 1894 did a Western explorer reach the meteorite: Robert E. Peary, of the US Navy. Peary enlisted the help of a local Inuit guide, who brought him to Saviksoah Island, just off northern Greenlands Cape York. Peary dedicated three years to planning and executing the removal of the meteorite, a process which required the building of a short railroad. Peary sold the pieces for $40,000 (equivalent to $ in ) to the American Museum of Natural History in New York City, where they are still on display. The piece named Ahnighito is on display in the Arthur Ross Hall of the American Museum of Natural History. Ahnighito' is the second-heaviest meteorite to have been relocated. It is so heavy that it was necessary to build its display stand so that the supports reached directly to the bedrock below the museum.
Peary has received significant criticism for his removal of the meteorite and treatment of the Inuit (including Minik Wallace). During his expedition to retrieve the meteorite, Peary convinced six Inughuit Greenlandic Inuit people ("three men, one woman, a boy, and a girl") to travel with him for study at the American Museum of Natural History in the United States, where four died within a few months.
In 1963, a fourth major piece of the Cape York meteorite was discovered by on Agpalilik peninsula. The , also known as the Man, weighs about , and it is currently on display in the Geological Museum of the University of Copenhagen, Denmark. Other smaller pieces have also been found, such as the Savik I meteorite found in 1911 and the Tunorput fragment found in 1984. Surveys of the area with a magnetometer in 2012 and georadar in 2014 found no evidence of further large iron fragments, either buried or on the surface. | 0 | Metallurgy |
The way that porosity develops during the dealloying process has been studied computationally to understand the diffusional pathways on an atomistic level. Firstly, the less noble atoms must be dissolved away from the surface of the alloy. This process is easiest for the lower coordinated atoms, i.e., those bonded to fewer other atoms, usually found as single atoms sitting on the surface ("adatoms"), but it is more difficult for higher coordinated atoms, i.e., those sitting at "steps" or in the bulk of the material. Thus, the slowest step, and that which is most important for determining rate of porosity evolution is the dissolution of these higher coordinated less noble atoms. Just as the less noble metal is less stable as an adatom on the surface, so is an atom of the more noble metal. Therefore, as dissolution proceeds, any more noble atoms will move to more stable positions, like steps, where its coordination is higher. This diffusion process is similar to spinodal decomposition. Eventually, clusters of more noble atoms form this way, and surrounding less noble atoms dissolve away, leaving behind a "bicontinuous structure" and providing a pathway for dissolution to continue deeper into the metal. | 0 | Metallurgy |
Activating Protein 2 (AP-2) is a family of closely related transcription factors which plays a critical role in regulating gene expression during early development. | 1 | Gene expression + Signal Transduction |
In many cases, gatekeeper genes encode a system of checks and balances that monitor cell division and death. When tissue damage occurs, for example, products of gatekeeper genes ensure that balance of cell growth over cellular death remains in check. In the presence of competent gatekeeper genes, mutations of other genes do not lead to on-going growth imbalances.
Mutations altering these genes lead to irregular growth regulation and differentiation. Each cell type has only one, or at least only very few, gatekeeper genes. If a person is predisposed to cancer, they have inherited a mutation in one of two copies of a gatekeeper gene. Mutation of the alternate allele leads to progression to neoplasia.
Historically, the term gatekeeper gene was first coined in association with the APC gene, a tumor suppressor that is consistently found to be mutated in colorectal tumors. Gatekeeper genes are in fact specific to the tissues in which they reside.
The probability that mutations occur in other genes increases when DNA repair pathway mechanisms are damaged as a result of mutations in caretaker genes. Thus, the probability that a mutation will take place in a gatekeeper gene increases when the caretaker gene has been mutated.
Apoptosis, or induced cell suicide, usually serves as a mechanism to prevent excessive cellular growth. Gatekeeper genes regulate apoptosis. However, in instances where tissue growth or regrowth is warranted, these signals must be inactivated or net tissue regeneration would be impossible. Thus, mutations in growth-controlling genes would lead to the characteristics of uncontrolled cellular proliferation, neoplasia, while in a parallel cell that had no mutations in the gatekeeper function, simple cell death would ensue. | 1 | Gene expression + Signal Transduction |
Mutations in TCF4 cause Pitt-Hopkins Syndrome (PTHS). These mutations cause TCF4 proteins to not bind to DNA properly and control the differentiation of the nervous system. It has been suggested that TCF4 loss-of-function leads to decreased Wnt signaling and, consequently, a reduced neural progenitor proliferation. In most cases that have been studied, the mutations were de novo, meaning it was a new mutation not found in other family members of the patient. Common symptoms of Pitt-Hopkins Syndrome include a wide mouth, gastrointestinal problems, developmental delay of fine motor skills, speech and breathing problems, epilepsy, and other brain defects. | 1 | Gene expression + Signal Transduction |
* DUSP1, DUSP2, DUSP3, DUSP4, DUSP5, DUSP6, DUSP7, DUSP8, DUSP9
* DUSP10, DUSP11, DUSP12, DUSP13, DUSP14, DUSP15, DUSP16, DUSP18, DUSP19
* DUSP21, DUSP22, DUSP23, DUSP26, DUSP27, DUSP28 | 1 | Gene expression + Signal Transduction |
Beryllide is an intermetallic compound of beryllium with other metals, e.g. zirconium, tantalum, titanium, nickel, or cobalt. Typical chemical formulae are BeTi and FeBe. These are hard, metal-like materials that display properties distinct from the constituents, especially with regards to their resilience toward oxidation. | 0 | Metallurgy |
Caustic embrittlement is the phenomenon in which the material of a boiler becomes brittle due to the accumulation of caustic substances. | 0 | Metallurgy |
C/EBPβ has been found to have a role in the development of osteoporosis. The full-length isoform of the C/EBPβ protein (LAP) activates the MafB gene, whereas the short isoform (LIP) suppresses it. MafB gene activation suppresses the formation of osteoclasts. Thus, upregulation of LAP diminishes the number of osteoclasts, and this weakens the osteoporotic process, whereas upregulation of LIP does the opposite, increasing loss of bone mass.
The LAP/LIP balance is determined by the mTOR protein. Inhibition of the expression of mTOR can stop osteoclast activity. | 1 | Gene expression + Signal Transduction |
The phosphatome of an organism is the set of phosphatase genes in its genome. Phosphatases are enzymes that catalyze the removal of phosphate from biomolecules. Over half of all cellular proteins are modified by phosphorylation which typically controls their functions. Protein phosphorylation is controlled by the opposing actions of protein phosphatases and protein kinases.
Most phosphorylation sites are not linked to a specific phosphatase, so the phosphatome approach allows a global analysis of dephosphorylation, screening to find the phosphatase responsible for a given reaction, and comparative studies between different phosphatases, similar to how protein kinase research has been impacted by the kinome approach. | 1 | Gene expression + Signal Transduction |
Sigma-2 receptors have been found to be highly expressed in proliferating cells, including tumor cells, and to play a role in the differentiation, morphology, and survival of those cells. By interacting with EGFR membrane proteins sigma-2 receptors play a role in the regulation of signals further downstream such as PKC and RAF. Both PKC and Raf kinase up regulate transcription and cell proliferation. | 1 | Gene expression + Signal Transduction |
The SH2 domain of Grb2 binds to phosphorylated tyrosine-containing peptides on receptors or scaffold proteins with a preference for pY-X-N-X, where X is generally a hydrophobic residue such as valine (see [http://sh2domain.org]).
The N-terminal SH3 domain binds to proline-rich peptides and can bind to the Ras-guanine exchange factor SOS.
The C-terminal SH3 domain binds to peptides conforming to a P-X-I/L/V/-D/N-R-X-X-K-P motif that allows it to specifically bind to proteins such as Gab-1. | 1 | Gene expression + Signal Transduction |
Vacuum induction melting (VIM) utilizes electric currents to melt metal within a vacuum. The first prototype was developed in 1920. Induction heating induces eddy currents within conductors. Eddy currents create heating effects to melt the metal. Vacuum induction melting has been used in both the aerospace and nuclear industries. | 0 | Metallurgy |
This pathway has a significant effect in the way genes are translated, restricting the amount of gene expression. It is still a new field in genetics, but its role in research has already led scientists to uncover numerous explanations for gene regulation. Studying nonsense-mediated decay has allowed scientists to determine the causes for certain heritable diseases and dosage compensation in mammals. | 1 | Gene expression + Signal Transduction |
Two Soviet scientists, B. R. Lazarenko and N. I. Lazarenko, were tasked in 1943 to investigate ways of preventing the erosion of tungsten electrical contacts due to sparking. They failed in this task but found that the erosion was more precisely controlled if the electrodes were immersed in a dielectric fluid. This led them to invent an EDM machine used for working difficult-to-machine materials such as tungsten. The Lazarenkos' machine is known as an R-C-type machine, after the resistor–capacitor circuit (RC circuit) used to charge the electrodes.
Simultaneously but independently, an American team, Harold Stark, Victor Harding, and Jack Beaver, developed an EDM machine for removing broken drills and taps from aluminium castings. Initially constructing their machines from under-powered electric-etching tools, they were not very successful. But more powerful sparking units, combined with automatic spark repetition and fluid replacement with an electromagnetic interrupter arrangement produced practical machines. Stark, Harding, and Beaver's machines produced 60 sparks per second. Later machines based on their design used vacuum tube circuits that produced thousands of sparks per second, significantly increasing the speed of cutting. | 0 | Metallurgy |
Shrinkage defects
can occur when standard feed metal is not available to compensate for shrinkage as the thick metal solidifies. Shrinkage defects will have jagged or linear appearance. Shrinkage defects usually occur in either the cope or drag portion of the casting. Shrinkage defects can be split into two different types: open shrinkage defects and closed shrinkage defects. Open shrinkage defects are open to the atmosphere, therefore as the shrinkage cavity forms, air compensates. There are two types of open air defects: pipes and caved surfaces. Pipes form at the surface of the casting and burrow into the casting, while caved surfaces are shallow cavities that form across the surface of the casting.
Closed shrinkage defects, also known as shrinkage porosity, are defects that form within the casting. Isolated pools of liquid form inside solidified metal, which are called hot spots. The shrinkage defect usually forms at the top of the hot spots. They require a nucleation point, so impurities and dissolved gas can induce closed shrinkage defects. The defects are broken up into macroporosity and microporosity (or micro shrinkage), where macroporosity can be seen by the naked eye and microporosity cannot. | 0 | Metallurgy |
Inhibition of proton pumps significantly decreases the acidity of the gastrointestinal tract, reducing the symptoms of acid-related diseases. The resulting change in pH decreases survival of the bacteria H.pylori, a major cause of peptic ulcer disease. Once the proton pump inhibitor eradicates this bacteria within the gut, reversing erosive reflux.
Treating heart disease has improved with the use of drugs that inhibit AMPK via dephosphorylation.
In the treatment of diabetes, sulfonylurea drugs are able to stimulate dephosphorylation of the glucose transporter GLUT4, decreasing insulin resistance and increasing and glucose utilization. | 1 | Gene expression + Signal Transduction |
Brazing (sometimes known as silver soldering or hard soldering) requires a higher temperature than soft soldering (> 450 °C). As well as removing existing oxides, rapid oxidation of the metal at the elevated temperatures has to be avoided. This means that fluxes need to be more aggressive and to provide a physical barrier. Traditionally borax was used as a flux for brazing, but there are now many different fluxes available, often using active chemicals such as fluorides as well as wetting agents. Many of these chemicals are toxic and due care should be taken during their use. | 0 | Metallurgy |
Liquation is a metallurgical method for separating metals from an ore or alloy. The material must be heated until one of the metals starts to melt and drain away from the other and can be collected. This method was largely used to remove lead containing silver from copper, but it can also be used to remove antimony from ore minerals, and refine tin.
The 16th-century process of separating copper and silver using liquation, described by Georg Agricola in his 1556 treatise De re metallica, remained almost unchanged until the 19th century when it was replaced by cheaper and more efficient processes such as sulphatization and eventually electrolytic methods. | 0 | Metallurgy |
Alclad is a corrosion-resistant aluminium sheet formed from high-purity aluminium surface layers metallurgically bonded (rolled onto) to high-strength aluminium alloy core material. It has a melting point of about . Alclad is a trademark of Alcoa but the term is also used generically.
Since the late 1920s, Alclad has been produced as an aviation-grade material, being first used by the sector in the construction of the ZMC-2 airship. The material has significantly more resistance to corrosion than most aluminium-based alloys, for only a modest increase in weight, making Alclad attractive for building various elements of aircraft, such as the fuselage, structural members, skin, and cowling. Accordingly, it became a relatively popular material for aircraft manufacturing. | 0 | Metallurgy |
For technical reasons, synaptic structure and function have been historically studied at unusually large model synapses, for example:
* Squid giant synapse
* Neuromuscular junction (NMJ), a cholinergic synapse in vertebrates, glutamatergic in insects
* Ciliary calyx in the ciliary ganglion of chicks
* Calyx of Held in the brainstem
* Ribbon synapse in the retina
* Schaffer collateral synapses in the hippocampus. These synapses are small, but their pre- and postsynaptic neurons are well separated (CA3 and CA1, respectively). | 1 | Gene expression + Signal Transduction |
Chemical synapses are biological junctions through which neurons' signals can be sent to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system to connect to and control other systems of the body.
At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis. These molecules then bind to neurotransmitter receptors on the postsynaptic cell. Finally, the neurotransmitters are cleared from the synapse through one of several potential mechanisms including enzymatic degradation or re-uptake by specific transporters either on the presynaptic cell or on some other neuroglia to terminate the action of the neurotransmitter.
The adult human brain is estimated to contain from 10 to 5 × 10 (100–500 trillion) synapses. Every cubic millimeter of cerebral cortex contains roughly a billion (short scale, i.e. 10) of them. The number of synapses in the human cerebral cortex has separately been estimated at 0.15 quadrillion (150 trillion)
The word "synapse" was introduced by Sir Charles Scott Sherrington in 1897. Chemical synapses are not the only type of biological synapse: electrical and immunological synapses also exist. Without a qualifier, however, "synapse" commonly refers to chemical synapses. | 1 | Gene expression + Signal Transduction |
A coating or paint is usually a fluid applied covering applied to a surface in contact with a corrosive situation such as the atmosphere. The surface is usually called the substrate. In corrosion prevention applications the purpose of applying the coating is mainly functional rather than decorative. Paints and lacquers are coatings that have dual uses of protecting the substrate and being decorative, but paint on large industrial pipes as well as preventing corrosion is also used for identification e.g. red for fire-fighting control etc. Functional coatings may be applied to change the surface properties of the substrate, such as adhesion, wettability, corrosion resistance, or wear resistance. In the automotive industry, coatings are used to control corrosion but also for aesthetic reasons. Coatings are also extensively used in marine environments to control corrosion in an oceanic environment. Corrosion will eventually breakthrough a coating and so have a design life before maintenance. | 0 | Metallurgy |
Carbon dioxide () from air and bicarbonate () or carbonate () anions dissolved in water react with the calcium hydroxide (, portlandite) produced by Portland cement hydration in concrete to form calcium carbonate () while releasing a water molecule in the following reaction:
Exception made of the water molecule, the carbonation reaction is essentially the reverse of the process of calcination of limestone taking place in a cement kiln:
Carbonation of concrete is a slow and continuous process of atmospheric diffusing from the outer surface of concrete exposed to air into its mass and chemically reacting with the mineral phases of the hydrated cement paste. Carbonation slows down with increasing diffusion depth.
Carbonation has two antagonist effects for (1) the concrete strength, and (2) its durability:
# The precipitation of calcite filling the microscopic voids in the concrete pore space decreases the concrete matrix porosity: so, it increases the mechanical strength of concrete;
# At the same time carbonation consumes portlandite and therefore decreases the concrete alkalinity reserve buffer. Hyper-alkaline conditions (i.e., basic chemical conditions) characterized by a high pH (typically 12.5 – 13.5) are needed to passivate the steel surface of the reinforcement bars (rebar) and to protect them from corrosion. Below a pH of 10, the solubility of the iron oxides forming a protective thin coating at the surface of carbon steel increases. The thin protective oxide layer starts to dissolve, and corrosion is then promoted. As the volumetric mass of iron oxides can be as high as 6 – 7 times that of metallic iron (Fe), a detrimental consequence is the expansion of the corrosion products around the rebar. This causes the development of a tensile stress in the concrete matrix around the rebar. When the tensile strength of concrete is exceeded in the concrete cover above the rebar, concrete starts to spall. Cracks appear in the concrete cover protecting the rebar against corrosion and constitute preferential pathways for direct ingress towards the rebar. This accelerates the carbonation reaction and in turn the corrosion process speeds up.
This explain why the carbonation reaction of reinforced concrete is an undesirable process in concrete chemistry. Concrete carbonation can be visually revealed by applying a phenolphthalein solution over the fresh surface of a concrete samples (concrete core, prism, freshly fractured bar). Phenolphthalein is a pH indicator, whose color turns from colorless at pH < 8.5 to pink-fuchsia at pH > 9.5. A violet color indicates still alkaline areas and thus non-carbonated concrete. Carbonated zones favorable for steel corrosion and concrete degradation are colorless.
The presence of water in carbonated concrete is necessary to lower the pH of concrete pore water around rebar and to depassivate the carbon steel surface at low pH. Water is central to corrosion processes. Without water, the steel corrosion is very limited and rebar present in dry carbonated concrete structures, or components, not affected by water infiltration do not suffer from significant corrosion. | 0 | Metallurgy |
Material properties such as strength, chemical reactivity, stress corrosion cracking resistance, weldability, deformation behavior, resistance to radiation damage, and magnetic susceptibility can be highly dependent on the material’s texture and related changes in microstructure. In many materials, properties are texture-specific, and development of unfavorable textures when the material is fabricated or in use can create weaknesses that can initiate or exacerbate failures. Parts can fail to perform due to unfavorable textures in their component materials. Failures can correlate with the crystalline textures formed during fabrication or use of that component. Consequently, consideration of textures that are present in and that could form in engineered components while in use can be a critical when making decisions about the selection of some materials and methods employed to manufacture parts with those materials. When parts fail during use or abuse, understanding the textures that occur within those parts can be crucial to meaningful interpretation of failure analysis data. | 0 | Metallurgy |
Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) is a protein that in humans is encoded by the PPARGC1A gene. PPARGC1A is also known as human accelerated region 20 (HAR20). It may, therefore, have played a key role in differentiating humans from apes.
PGC-1α is the master regulator of mitochondrial biogenesis. PGC-1α is also the primary regulator of liver gluconeogenesis, inducing increased gene expression for gluconeogenesis. | 1 | Gene expression + Signal Transduction |
An intermediate stage in the process of eukaryotic RNA splicing is the formation of a lariat structure. It is anchored at an adenosine residue in intron between 10 and 50 nucleotides upstream of the 3' splice site. A short conserved sequence (the branch point sequence) functions as the recognition signal for the site of lariat formation. During the splicing process, this conserved sequence towards the end of the intron forms a lariat structure with the beginning of the intron. The final step of the splicing process occurs when the two exons are joined and the intron is released as a lariat RNA.
Several investigators found the branch point sequences in different organisms including yeast, human, fruit fly, rat, and plants. Senapathy found that, in all of these sequences, the codon ending at the branch point adenosine is consistently a stop codon. What is interesting is that two of the three stop codons (TAA and TGA) occur almost all of the time at this position.
These findings led Senapathy to propose that the branch point signal originated from stop codons. The finding that two different stop codons (TAA and TGA) occur within the lariat signal with the branching point as the third base of the stop codons corroborates this proposal. As the branching point of the lariat occurs at the last adenine of the stop codon, it is possible that the spliceosome machinery that originated for the elimination of the stop codons from the primary RNA sequence created an auxiliary stop-codon sequence signal as the lariat sequence to aid its splicing function.
The small nuclear U2 RNA found in splicing complexes is thought to aid splicing by interacting with the lariat sequence. Complementary sequences for both the lariat sequence and the acceptor signal are present in a segment of only 15 nucleotides in U2 RNA. Further, the U1 RNA has been proposed to function as a guide in splicing to identify the precise donor splice junction by complementary base-pairing. The conserved regions of the U1 RNA thus include sequences complementary to the stop codons. These observations enabled Senapathy to predict that stop codons had operated in the origin of not only the splice-junction signals and the lariat signal, but also some small nuclear RNAs. | 1 | Gene expression + Signal Transduction |
The problem of landslides in spoil tips was first brought to public attention in October 1966 in English speaking world when a spoil tip at Aberfan in Wales gave way, killing 144 people, 116 of them children. The tip was built over a spring, increasing its instability, and its height exceeded guidelines. Water from heavy rainfall had built up inside the tip, weakening the structure, until it suddenly collapsed onto a school below.
The wider issue of stability had been known about prior to the Aberfan disaster; for example, it was discussed in a paper by Professor George Knox in 1927, but received little serious consideration by professional engineers and geologists — even to those directly concerned with mining. Also Aberfan disaster was not the first landslide with casualties: for example, in 1955 two successive landslides killed 73 people in Sasebo, Nagasaki in Japan.[ja]
In February 2013, a spoil tip landslip caused the temporary closure of the Scunthorpe to Doncaster railway line in England.
Landslides are rare in spoil tips after settling and vegetation growth act to stabilise the spoil. However, when heavy rain falls on spoil tips that are undergoing combustion, infiltrated water changes to steam; increasing pressure that may lead to a landslide. In Herstal, Belgium, a landslide on the Petite Bacnure spoil tip in April 1999 closed off a street for many years. | 0 | Metallurgy |
Modulation of neurotransmitter release by G-protein-coupled receptors (GPCRs) is a prominent presynaptic mechanism for regulation of synaptic transmission. The activation of GPCRs located at the presynaptic terminal, can decrease the probability of neurotransmitter release. This presynaptic depression involves activation of Gi/o-type G-proteins that mediate different inhibitory mechanisms, including inhibition of voltage-gated calcium channels, activation of potassium channels, and direct inhibition of the vesicle fusion process. Endocannabinoids, synthesized in and released from postsynaptic neuronal elements, and their cognate receptors, including the (GPCR) CB1 receptor, located at the presynaptic terminal, are involved in this modulation by a retrograde signaling process, in which these compounds are synthesized in and released from postsynaptic neuronal elements, and travel back to the presynaptic terminal to act on the CB1 receptor for short-term or long-term synaptic depression, that cause a short or long lasting decrease in neurotransmitter release. | 1 | Gene expression + Signal Transduction |
According to a research study conducted Hutton, M et al, a missense mutation occurring on the 5 region of the RNA associated with the tau protein was found to be correlated with inherited dementia (known as FTDP-17). The splice-site mutations all destabilize a potential stem–loop structure which is most likely involved in regulating the alternative splicing of exon10 in chromosome 17. Consequently, more usage occurs on the 5 splice site and an increased proportion of tau transcripts that include exon 10 are created. Such drastic increase in mRNA will increase the proportion of Tau containing four microtubule-binding repeats, which is consistent with the neuropathology described in several families with FTDP-17, a type inherited dementia. | 1 | Gene expression + Signal Transduction |
Pattinson's process or pattinsonisation is a method for removing silver from lead, discovered by Hugh Lee Pattinson in 1829 and patented in 1833.
The process is dependent on the fact that lead which has least silver in it solidifies first on liquefaction, leaving the remaining liquid richer in silver.
In practice several crystallisations were required, so Pattinson's equipment consisted basically of nothing more complex than a row of up to 13 iron pots, which were heated from below. Some lead, naturally containing a small percentage of silver, was loaded into the central pot and melted. This was then allowed to cool. As the lead solidified it was removed using large perforated iron ladles and moved to the next pot in one direction, and the remaining metal which was now richer in silver was then transferred to the next pot in the opposite direction. The process was repeated from one pot to the next, the lead accumulating in the pot at one end and metal enriched in silver in the pot at the other.
The level of enrichment possible is limited by the lead-silver eutectic and typically the silver content of the silver-rich melt could not be raised above 2% (around 600 to 700 ounces per ton), so further separation is carried out by cupellation.
The process was economic for lead containing at least 250 grams of silver per ton. Being the first process applicable to low-grade lead, it supplemented earlier patio process and pan amalgamation.
It was replaced by the Parkes process in the mid-19th century. | 0 | Metallurgy |
Titanium boride (TiB) is intentionally added to the melt for grain refinement to improve mechanical properties.
Phosphorus is added to the melt hypereutectic alloys for modification of the silicon phase for better mechanical properties. This creates AlP inclusions.
Boron treatment inclusions ( (Ti, V)B ) form when boron is added to the melt to increase conductivity by precipitating vanadium and titanium. | 0 | Metallurgy |
Precipitation in hydrometallurgy involves the chemical precipitation from aqueous solutions, either of metals and their compounds or of the contaminants. Precipitation will proceed when, through reagent addition, evaporation, pH change or temperature manipulation, the amount of a species present in the solution exceeds the maximum determined by its solubility. | 0 | Metallurgy |
The pan amalgamation process is a method to extract silver from ore, using salt and copper(II) sulfate in addition to mercury. The process was widely used from 1609 through the 19th century; it is no longer used.
The patio process had been used to extract silver from ore since its invention in 1557. One drawback of the patio process was the long treatment time, usually weeks. Alvaro Alonso Barba invented the faster pan process (in Spanish the cazo or fondo process) in 1609 in Potosí, Bolivia, in which ore was mixed with salt and mercury (and sometimes copper(II) sulfate) and heated in shallow copper vessels. The treatment time was reduced to 10 to 20 hours. Whether patio or pan amalgamation was used at a particular location often depended on climate (warmer conditions speeded the patio process) and the availability and cost of fuel to heat the pans.
The amount of salt and copper(II) sulfate varied from one-quarter to ten pounds of one or the other, or both, per ton of ore treated. The loss of mercury in amalgamation processes was generally one to two times the weight of silver recovered. | 0 | Metallurgy |
When an antigen-presenting cell interacts with a T cell receptor on T cells, there is an increase in the cytoplasmic level of calcium, which activates calcineurin by binding a regulatory subunit and activating calmodulin binding. Calcineurin induces transcription factors (NFATs) that are important in the transcription of IL-2 genes. IL-2 activates T-helper lymphocytes and induces the production of other cytokines. In this way, it governs the action of cytotoxic lymphocytes. The amount of IL-2 being produced by the T-helper cells is believed to influence the extent of the immune response significantly. | 1 | Gene expression + Signal Transduction |
Histidine phosphotransfer domains and histidine phosphotransferases (both often abbreviated HPt) are protein domains involved in the "phosphorelay" form of two-component regulatory systems. These proteins possess a phosphorylatable histidine residue and are responsible for transferring a phosphoryl group from an aspartate residue on an intermediate "receiver" domain, typically part of a hybrid histidine kinase, to an aspartate on a final response regulator. | 1 | Gene expression + Signal Transduction |
*NDUFA2NM_002488
*NDUFA3 NM_004542
*NDUFA4 NM_002489
*NDUFA5 NM_005000
*NDUFA6 NM_002490
*NDUFA7 NM_005001 Homo sapiens NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 7, 14.5kDa
*NDUFA8 NM_014222
*NDUFA9 NM_005002
*NDUFA10 NM_004544
*NDUFA11 NM_175614
*NDUFA12 NM_018838
*NDUFA13 NM_015965
*NDUFAF2 NM_174889
*NDUFAF3 NM_199069
*NDUFAF4 NM_014165
*NDUFB2 NM_004546
*NDUFB3 NM_002491
*NDUFB4 NM_004547
*NDUFB5 NM_002492
*NDUFB6 NM_002493
*NDUFB7 NM_004146 Homo sapiens NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 7, 18kDa
*NDUFB10 NM_004548
*NDUFB11 NM_019056
*NDUFB8 NM_005004
*NDUFB9 NM_005005
*NDUFC1 NM_002494Homo sapiens NADH dehydrogenase (ubiquinone) 1, subcomplex unknown, 1, 6kDa
*NDUFC2 NM_004549
*NDUFC2-KCTD14 NM_001203260
*NDUFS5
*NDUFV2
*NDUFS2 NM_004550
*NDUFS3 NM_004551
*NDUFS4 NM_002495
*NDUFS5 NM_004552 Homo sapiens NADH dehydrogenase (ubiquinone) Fe-S protein 5, 15kDa
*NDUFS6 NM_004553
*NDUFS7 NM_024407
*NDUFS8 NM_002496
*NDUFV1 NM_007103 Homo sapiens NADH dehydrogenase (ubiquinone) flavoprotein 1, 51kDa (NDUFV1),
*NDUFV2 NM_021074 Homo sapiens NADH dehydrogenase (ubiquinone) flavoprotein 2, 24kDa (NDUFV2), | 1 | Gene expression + Signal Transduction |
Rose's metal has several common uses:
#As a solder. It was used to secure cast iron railings and balusters in pockets in stone bases and steps.
#As a heat transfer medium in heating baths.
#As a malleable filling to prevent tubes and pipes from crimping when bent. Roses metal is melted and poured into the tube. It then solidifies in place but remains malleable. This allows the tube or pipe to be bent and reworked without crimping. After the desired shape is achieved the Roses metal is remelted and removed, leaving the pipe or tube in its modified shape. | 0 | Metallurgy |
Advantages cited for the IsaKidd technology include:
* long life – the operational life of the permanent cathodes without repair is said to be over seven years under correct operating conditions for electrowinning applications and over 15 years for electrorefining applications
* reduced labour costs – due to the elimination of the starter-sheet production process and the automation of cathode stripping. The average labour requirement for refineries based on the IsaKidd technology is 0.9 man-hours per tonne of cathode, compared to 2.4 man-hours/t for tank houses using starter sheets. Atlantic Copper personnel reported a figure of 0.43 man-hours/t for the Huelva refinery in Spain in 1998
* no suspension loops – the suspension loops of starter sheets can corrode and thus cause cutting of the electrolytic cell liners. The lack of suspension loops also makes crane handling easier
* improved cathode quality – due to the straight cathode plates, which eliminates short-circuiting, and the lack of bends and other surface irregularities reduces the capture of contaminants such as floating arsenic, antimony and bismuth and other slimes compounds. The elimination of the starter-sheet suspension loops also improved cathode quality. In SX–EW operations, the use of stainless-steel cathode plates eliminates lead flakes and other debris from the cathode copper.
* improved current efficiency – this arises both from eliminating short circuits caused by bent and irregular electrodes and from the shorter cathode cycles possible with the use of the reusable cathode plates. Current efficiencies of over 98% are claimed
* increased refining intensity – this reduces the number of electrolytic cells needed in a refinery and its capital cost because the gap between the anodes and the cathodes can be narrower due to the lower risk of short circuits and because the current density can be increased, making the refining process faster. Refineries operating with the IsaKidd technology can achieve current densities of 330 amperes per square meter (“A/m”) of cathode area, whereas a refinery using starter sheets can only operate at around 240 A/m
* shorter cathode cycles – shorter cathode cycles are possible using the IsaKidd technology, which reduces the metal inventory and means that the refinery or SX–EW operator is paid more quickly
* shorter anode cycles – the higher intensity of the refining also results in about a 12% reduction in anode cycle time, also reducing the metal inventory
* uniform cathode copper sheets for ease of transport – the control over the dimensions of the copper sheets made possible by the IsaKidd technology, provides uniform cathode bundles that can be securely strapped and easily transported (see Figure 7)
* improved safety – elimination of much of the manual handling leads to improved safety conditions in the workplace.
Staff of the Cyprus Miami copper refinery wrote after their installation of the Isa Process technology that: “It is now well proven that tankhouses applying stainless steel cathode technology can consistently produce high quality cathodes while operating at higher cathode current density and at a lower cathode spacing than those used in conventional tankhouses.” | 0 | Metallurgy |
In recent publications, prof. Sindo Kou has proposed an approach to evaluate susceptibility to solidification cracking; this approach is based on a similar approach where a quantity, , which has the dimensions of a temperature is proposed as an index of the cracking susceptibility. Again one could exploit Scheil based solidification curves to link this index to the slope of the (Scheil) solidification curve:
∂T/(∂(fS)^1/2)=
∂T/(∂(fS)*(∂(fS)^1/2)/∂(fS))=
(1/2)∂T/∂(fS)*(fS)^1/2= | 0 | Metallurgy |
* 999.99—five nines fine: The purest silver ever produced. This was achieved by the Royal Silver Company of Bolivia.
* 999.9—four nines fine: ultra-fine silver used by the Royal Canadian Mint for their Silver Maple Leaf and other silver coins
* 999—fine silver or three nines fine: used in Good Delivery bullion bars and most current silver bullion coins. Used in U.S. silver commemorative coins and silver proof coins starting in 2019.
* 980: common standard used in Mexico ca. 1930–1945
* 958: () Britannia silver
* 950: French 1st Standard
* 947.9: 91 zolotnik Russian silver
* 935: Swiss standard for watchcases after 1887, to meet the British Merchandise Marks Act and to be of equal grade to 925 sterling. Sometimes claimed to have arisen as a Swiss misunderstanding of the standard required for British sterling. Usually marked with three Swiss bears.
* 935: used in the Art Deco period in Austria and Germany. Scandinavian silver jewellers used 935 silver after the 2nd World War
* 925: () Sterling silver The UK has used this alloy from the early 12th century. Equivalent to plata de primera ley in Spain (first law silver)
* 917: a standard used for the minting of Indian silver (rupees), during the British raj and for some coins during the first Brazilian Republic.
* 916: 88 zolotnik Russian silver
* 900: one nine fine, coin-silver, or 90% silver: e.g. Flowing Hair and 1837–1964 U.S. silver coins. Also used in U.S. silver commemorative coins and silver proof coins 1982–2018.
* 892.4: US coinage fine "standard silver" as defined by the Coinage Act of 1792: e.g. Draped Bust and Capped Bust U.S. silver coins (1795–1836)
* 875: 84 zolotnik is the most common fineness for Russian silver. Swiss standard, commonly used for export watchcases (also 800 and later 935).
* 868: 83 zolotnik. Imperial Russian coinage between 1797 and 1885.
* 835: A standard predominantly used in Germany after 1884, and for some Dutch silver; and for the minting of coins in countries of the Latin Monetary Union
* 833: () a common standard for continental silver especially among the Dutch, Swedish, and Germans
* 830: A common standard used in older Scandinavian silver
* 800: The minimum standard for silver in Germany after 1884; the French 2nd standard for silver; "plata de segunda ley" in Spain (second law silver); Egyptian silver; Canadian silver circulating coinage from 1920-1966/7
* 750: An uncommon silver standard found in older German, Swiss and Austro-Hungarian silver
* 720: Decoplata: many Mexican and Dutch silver coins use this standard, as well as some coins from Portugal's former colonies, Japan, Uruguay, Ecuador, Egypt, and Morocco.
* 600: Used in some examples of postwar Japanese coins, such as the 1957-1966 100 yen coin
* 500: Standard used for making British coinage 1920–1946 as well as Canadian coins from 1967-1968, and some coins from Colombia and Brazil.
* 400: Standard used for US half dollars between 1965 and 1970, and commemorative issue Eisenhower dollars between 1971 and 1978. Also used in some Swedish Krona coins.
* 350: Standard used for US Jefferson "war nickels" minted between 1942 and 1945. | 0 | Metallurgy |
G stimulates the membrane-bound phospholipase C beta, which then cleaves PIP (a minor membrane phosphoinositol) into two second messengers, IP3 and diacylglycerol (DAG).
The Inositol Phospholipid Dependent Pathway is used as a signal transduction pathway for many hormones including:
* ADH (Vasopressin/AVP) – Induces the synthesis and release of glucocorticoids (Zona fasciculata of adrenal cortex); Induces vasoconstriction (V1 Cells of Posterior pituitary)
* TRH – Induces the synthesis and release of TSH (Anterior pituitary gland)
* TSH – Induces the synthesis and release of a small amount of T4 (Thyroid Gland)
* Angiotensin II – Induces Aldosterone synthesis and release (zona glomerulosa of adrenal cortex in kidney)
* GnRH – Induces the synthesis and release of FSH and LH (Anterior Pituitary) | 1 | Gene expression + Signal Transduction |
* Hepatitis C infection
* Antisocial personality disorder
* Borderline personality traits
* Schizoid/avoidant behavior
Given that the A1+ allele is associated with antisocial personality disorder, one may infer that the allele is also associated with narcissistic personality disorder and histrionic personality disorder. However, these predictions have not yet been empirically verified. | 1 | Gene expression + Signal Transduction |
Genetic regulatory circuits (also referred to as transcriptional regulatory circuits) is a concept that evolved from the Operon Model discovered by François Jacob and Jacques Monod. They are functional clusters of genes that impact each other's expression through inducible transcription factors and cis-regulatory elements.
Genetic regulatory circuits are analogous in many ways to electronic circuits in how they use signal inputs and outputs to determine gene regulation. Like electronic circuits, their organization determines their efficiency, and this has been demonstrated in circuits working in series to have a greater sensitivity of gene regulation. They also use inputs such as trans and cis sequence regulators of genes, and outputs such as gene expression level. Depending on the type of circuit, they respond constantly to outside signals, such as sugars and hormone levels, that determine how the circuit will return to its fixed point or periodic equilibrium state. Genetic regulatory circuits also have an ability to be evolutionarily rewired without the loss of the original transcriptional output level. This rewiring is defined by the change in regulatory-target gene interactions, while there is still conservation of regulatory factors and target genes. | 1 | Gene expression + Signal Transduction |
In winter conditions, or in cold climates, when the temperature falls below , the crystallization of ice in the pores of concrete is also a physical mechanism (change of state) responsible for the volumetric expansion of a substance exerting a high tensile strength inside the concrete matrix. When the tensile strength of concrete is exceeded, cracks appear. Adding an air entrainment agent during the mixing of fresh concrete induces the formation of tiny air bubbles in the fresh concrete slurry. This creates numerous small air-filled micro-cavities in the hardened concrete serving as empty volume reserve to accommodate the volumetric expansion of ice and delays the moment tensile stress will develop. Air entrainment makes concrete more workable during placement, and increases its durability when hardened, particularly in climates subject to freeze-thaw cycles. | 0 | Metallurgy |
The expansion of gold mining in the Rand of South Africa began to slow down in the 1880s, as the new deposits being found tended to contain pyritic ore. The gold could not be extracted from this compound with any of the then available chemical processes or technologies.
In 1887, John Stewart MacArthur, working in collaboration with brothers Robert and William Forrest for the Tennant Company in Glasgow, Scotland, developed the MacArthur–Forrest process for the extraction of gold from gold ores. Several patents were issued in the same year. By suspending the crushed ore in a cyanide solution, a separation of up to 96 percent pure gold was achieved.
The process was first used on the Rand in 1890 and, despite operational imperfections, led to a boom of investment as larger gold mines were opened up.
By 1891, Nebraska pharmacist Gilbert S. Peyton had refined the process at his Mercur Mine in Utah, "the first mining plant in the United States to make a commercial success of the cyanide process on gold ores." In 1896, Bodländer confirmed that oxygen was necessary for the process, something that had been doubted by MacArthur, and discovered that hydrogen peroxide was formed as an intermediate.
Around 1900, the American metallurgist Charles Washington Merrill (1869–1956) and his engineer Thomas Bennett Crowe improved the treatment of the cyanide leachate, by using vacuum and zinc dust. Their process is the Merrill–Crowe process. | 0 | Metallurgy |
In the adult brain, PPs are essential for synaptic functions and are involved in the negative regulation of higher-order brain functions such as learning and memory. Dysregulation of their activity has been linked to several disorders including cognitive ageing and neurodegeneration, as well as cancer, diabetes and obesity. | 1 | Gene expression + Signal Transduction |
Light microscopes are designed for placement of the specimen's polished surface on the specimen stage either upright or inverted. Each type has advantages and disadvantages. Most LOM work is done at magnifications between 50 and 1000X. However, with a good microscope, it is possible to perform examination at higher magnifications, e.g., 2000X, and even higher, as long as diffraction fringes are not present to distort the image. However, the resolution limit of the LOM will not be better than about 0.2 to 0.3 micrometers. Special methods are used at magnifications below 50X, which can be very helpful when examining the microstructure of cast specimens where greater spatial coverage in the field of view may be required to observe features such as dendrites.
Besides considering the resolution of the optics, one must also maximize visibility by maximizing image contrast. A microscope with excellent resolution may not be able to image a structure, that is there is no visibility, if image contrast is poor. Image contrast depends upon the quality of the optics, coatings on the lenses, and reduction of flare and glare; but, it also requires proper specimen preparation and good etching techniques. So, obtaining good images requires maximum resolution and image contrast. | 0 | Metallurgy |
FSP has benefits for when two materials' would be needed to be mixed. “FSP is a short route, solid state processing technique with one-step processing that achieves microstructural refinement densification and homogeneity” (Ma) FSW helps modify materials so that metaling down or changing the material drastically does not have to take place. FSP, for example, can easily change the form of a piece of material as sheets of metal, where before it may have had to be melted down before and put into a mold for it to cool and form. (Smith, Mishra) “The microstructure and mechanical properties of the processed zone can be accurately controlled by optimizing the tool design, FSP parameters an active cooling/heating.” (Ma) The same sheet of metal can be modified to fit various situations with the proper modification of the tool. FSP has shown to make metallic alloys bendable as for example an alloy modified with FSP would be able to bend to 30 degrees as before it could only bend to seven. | 0 | Metallurgy |
The model represents individuals as networks of interacting transcriptional regulators. Each individual expresses genes encoding transcription factors. The product of each gene can regulate the expression level of itself and/or the other genes through cis-regulatory elements. The interactions among genes constitute a gene network that is represented by a × regulatory matrix in the model. The elements in matrix R represent the interaction strength. Positive values within the matrix represent the activation of the target gene, while negative ones represent repression. Matrix elements with value 0 indicate the absence of interactions between two genes. | 1 | Gene expression + Signal Transduction |
The outbreak of hostilities in eastern Ukraine in 2014 complicated the activities of the enterprise. As a result, the plant ended 2014 with a net loss of UAH 4,871.533 million. In the first nine months of 2015, the plant produced 426 thousand tons of pig iron and 1.664 million tons of grade K coal concentrate, but losses continued to increase.
In June 2016, the leadership of the unrecognized DPR introduced external management at the plant, by which time its communications and a significant part of the equipment had become unusable due to repeated shutdowns and long downtime.
Also in June 2016, on the basis of the Donetsk Electrometallurgical Plant (DEMP), the state enterprise Yuzovsky Metallurgical Plant was opened. The YuMZ industrial complex is located on the same territory as the Donetsk Metallurgical Plant, which, in turn, is located in three districts of the DPR capital at once - Voroshilovsky, Budenovsky, Leninsk.
It was Re-launched on October 5, 2017.
In 2018 YuMZ began to supply products to Turkey, Iran and Syria.
Since May 1, 2019, blast-furnace production has been stopped. The company does not manufacture products. During the heating period of 2019–2020, only the factory CHPP-PVS and related power plants worked, in order to supply heat to part of the above three districts of the city of Donetsk.
From March to August 2020, the plant suspended work due to a shortage of raw materials. As of November 2020, the YuMZ complex, separated from the main part of the plant, continues to produce steel, specializing in the production of continuously cast square billets. The workforce consists of 858 people.
At the DMZ, there are energy workshops that provide transit and supply to factory consumers and sub-consumers of drinking and industrial water, electricity, natural gas, steam and hot water. | 0 | Metallurgy |
Thermal spraying need not be a dangerous process if the equipment is treated with care and correct spraying practices are followed. As with any industrial process, there are a number of hazards of which the operator should be aware and against which specific precautions should be taken. Ideally, equipment should be operated automatically in enclosures specially designed to extract fumes, reduce noise levels, and prevent direct viewing of the spraying head. Such techniques will also produce coatings that are more consistent. There are occasions when the type of components being treated, or their low production levels, require manual equipment operation. Under these conditions, a number of hazards peculiar to thermal spraying are experienced in addition to those commonly encountered in production or processing industries. | 0 | Metallurgy |
Metal smiths demonstrated increasing technical sophistication, producing both utilitarian and status-linked items. During the latter phase, Michoacán emerged as a technological hub, with metal artifacts also appearing at the adjacent zones of Guerrero and Jalisco.
Alloys became more prevalent during the second phase, as metal workers experimented with color, strength and fluidity. Formerly utilitarian assemblages transformed, with new focus placed upon metallic status objects. Further, the appearance of a copper-tin bronze alloy suggests contact between West Mexico and Peru during this period. However, many of the alloys/alloy concentrations used in West Mexico appear to reflect local innovation.
Scholars such as Dorothy Hosler suggest that ancient Mesoamericans were unique in their attention to the peculiar aesthetic properties of metals, such as the brilliant sounds and colors evoked through the movement of metallic objects. The rather late emergence of metallurgy in ancient Mesoamerica likely contributed to its novelty and subsequent role as a marker of elite status.
It has been suggested that Mesoamerican metal smiths produced particular alloys with the chief aim of exploiting the alloys’ emergent color properties, particularly the vivid gold tones produced through infusion of tin, and the silver shades that develop at high arsenic concentrations. Notably, certain artifacts from West Mexico contain tin or arsenic at concentrations as high as 23 weight percent, while concentrations of alloying elements at roughly 2 to 5 weight percent are typically adequate for augmented strength and mechanical utility.
Metal smiths in pre-Columbian West Mexico particularly exploited the brilliance inherent in metallic sound and sheen, suggesting that their creations tended to occupy a sacred and symbolic space. Metallic colors, gold and silver, might have been connected with solar and lunar deities while bell sounds have been associated with fertility rituals and protection in warfare. | 0 | Metallurgy |
Platinum-samarium is a binary inorganic compound of platinum and samarium with the chemical formula PtSm. This intermetallic compound forms crystals. | 0 | Metallurgy |
In heap leaching processes, crushed (and sometimes agglomerated) ore is piled in a heap which is lined with an impervious layer. Leach solution is sprayed over the top of the heap, and allowed to percolate downward through the heap. The heap design usually incorporates collection sumps, which allow the "pregnant" leach solution (i.e. solution with dissolved valuable metals) to be pumped for further processing. An example is gold cyanidation, where pulverized ores are extracted with a solution of sodium cyanide, which, in the presence of air, dissolves the gold, leaving behind the nonprecious residue. | 0 | Metallurgy |
Pyrometallurgy involves high temperature processes where chemical reactions take place among gases, solids, and molten materials. Solids containing valuable metals are treated to form intermediate compounds for further processing or converted into their elemental or metallic state. Pyrometallurgical processes that involve gases and solids are typified by calcining and roasting operations. Processes that produce molten products are collectively referred to as smelting operations. The energy required to sustain the high temperature pyrometallurgical processes may derive from the exothermic nature of the chemical reactions taking place. Typically, these reactions are oxidation, e.g. of sulfide to sulfur dioxide . Often, however, energy must be added to the process by combustion of fuel or, in the case of some smelting processes, by the direct application of electrical energy.
Ellingham diagrams are a useful way of analysing the possible reactions, and so predicting their outcome. | 0 | Metallurgy |
The following example illustrates how a Boolean network can model a GRN together with its gene products (the outputs) and the substances from the environment that affect it (the inputs). Stuart Kauffman was amongst the first biologists to use the metaphor of Boolean networks to model genetic regulatory networks.
# Each gene, each input, and each output is represented by a node in a directed graph in which there is an arrow from one node to another if and only if there is a causal link between the two nodes.
# Each node in the graph can be in one of two states: on or off.
# For a gene, "on" corresponds to the gene being expressed; for inputs and outputs, "on" corresponds to the substance being present.
# Time is viewed as proceeding in discrete steps. At each step, the new state of a node is a Boolean function of the prior states of the nodes with arrows pointing towards it.
The validity of the model can be tested by comparing simulation results with time series observations. A partial validation of a Boolean network model can also come from testing the predicted existence of a yet unknown regulatory connection between two particular transcription factors that each are nodes of the model. | 1 | Gene expression + Signal Transduction |
HIV, the retrovirus that causes AIDS in humans, produces a single primary RNA transcript, which is alternatively spliced in multiple ways to produce over 40 different mRNAs. Equilibrium among differentially spliced transcripts provides multiple mRNAs encoding different products that are required for viral multiplication. One of the differentially spliced transcripts contains the tat gene, in which exon 2 is a cassette exon that may be skipped or included. The inclusion of tat exon 2 in the RNA is regulated by competition between the splicing repressor hnRNP A1 and the SR protein SC35. Within exon 2 an exonic splicing silencer sequence (ESS) and an exonic splicing enhancer sequence (ESE) overlap. If A1 repressor protein binds to the ESS, it initiates cooperative binding of multiple A1 molecules, extending into the 5’ donor site upstream of exon 2 and preventing the binding of the core splicing factor U2AF35 to the polypyrimidine tract. If SC35 binds to the ESE, it prevents A1 binding and maintains the 5’ donor site in an accessible state for assembly of the spliceosome. Competition between the activator and repressor ensures that both mRNA types (with and without exon 2) are produced. | 1 | Gene expression + Signal Transduction |
In its earliest forms, most hardware was simple and hand-made – usually of readily available materials such as wood or leather. A patch of leather spanning between the stile and jamb and fastened with wooden pegs served to hinge a door or shutter. Hand-carved wooden hinges and pintles, slide bolts and lift-latches were whittled from a variety of woods.
The earliest examples of iron hardware were sponsored by the nobility. Iron itself was expensive and a valued resource for any kingdom and had many other more valuable uses in weaponry and tools.
In the post-Renaissance period industrial advances provided more iron and the emerging merchant/tradesman classes had money to purchase hardware for their homes and warehouses. Examples of hardware excavated from the Jamestown and Plymouth colonies of the 17th century were very ornate in design – typical of that being produced in England at the time.
In Colonial America, hardware was made in England and imported to the colonies. It was illegal for the colonials to produce manufactured goods. America sold iron and charcoal to the British, who used those raw materials and their resident labor force to produce hardware which was then sold back to the captive market in the colonies. Virtually all of the early hardware in New York, Philadelphia, Annapolis, Alexandria, Key West, or anyplace else where British ships could berth, was made in England. Away from the ports and cities where British authority was centered, many locally-made examples of early hardware can be found. Examples of German, French, and Dutch hardware remain in the inland river valleys – the homelands of the early settlers. English hardware, however, was the overwhelming standard in colonial America and set the pattern for all that evolved.
Virtually all of the shutters in colonial times were hung with strap hinges – following the examples in Britain. Strap hinges were strong and secure. The frames of windows were hewn from a single heavy piece of wood into which a heavy pintle could be driven. The rails of the shutter were often six or eight inches high and provided room to position the strap hinge across most of the width of the shutter. The hinges were fastened to the shutters with rivets or nails driven through and clinched on the inside of the closed shutter. Locks of the period followed the form of the strap hinges. The rolled barrel was replaced by a pin of about " in diameter and twice the length of the thickness of the shutter mounted perpendicular to the face of the lock. The lock would be nailed or riveted on the lock rail of one shutter with the pin positioned about two inches beyond the edge of the shutter. The opposite shutter would be drilled through with a hole to accept the pin protruding from the lock.
To close and secure the shutter: from the inside close the shutter with the hole then close the shutter with the lock. The lock pin passes through the hole and the user drops a simple nail-like key into the hole in the lock pin. The shutter is virtually impregnable from the exterior.
Tie-backs of the Colonial era were mostly of English origin and many were of the "Rattail" style. Variations are noted as different British manufacturers vied to produce a less expensive product. Inland, where local smiths were producing hardware on their own, a wide range of patterns have been noted. | 0 | Metallurgy |
A partially coherent interphase boundary is an intermediate type of IPB that lies between the completely coherent and non-coherent IPBs. In this type of boundary, there is a partial match between the atomic arrangements of the particle and the matrix, but not a perfect match. As a result, coherency strains are partially relieved, but not completely eliminated. The periodic introduction of dislocations along the boundary plays a key role in partially relieving the coherency strains. These dislocations act as periodic defects that accommodate the lattice mismatch between the particle and the matrix. The dislocations can be introduced during the precipitation process or during subsequent annealing treatments. | 0 | Metallurgy |
Copperas works are manufactories where copperas (iron(II) sulfate) is produced from pyrite, often obtained as a byproduct during coal mining, and iron. The history of producing green vitriol, as it was known, goes back hundreds of years in Scotland. In 1814 the wool-producing city of Steubenville, Ohio had seven copperas-producing manufacturers.
Pyrite has been used since classical times to manufacture copperas. Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching). The acidic runoff from the heap was then boiled with iron to produce iron sulfate.
Containment of leachate is important due to its toxicity; a fish kill that occurred in the 1890s in the Kanawha River was attributed to copperas solution release from the mines in Cannelton, West Virginia.
The "vitriolic waters of Fahlun" (Falun, Sweden), according to Murray (1844), annually produced "about 600 quintals of green vitriol" (sulfate of iron), as well as a "small quantity of blue vitriol" (sulfate of copper). These may have been obtained through evaporation of the groundwater associated with mines in order to yield the crystalline form of copperas. | 0 | Metallurgy |
Scrubbers are material washers used to break down and disperse clays in order to prepare mineral ores or construction aggregates for further processing. Sepro Tyre Drive Scrubbers are manufactured up to 3.6m in diameter and are capable of processing up to 1500 tonnes per hour of material. Shell supported Scrubbers such as the Sepro PTD Scrubber minimize stress on the shell by spreading the power drive over the full length of the washing drum. These scrubbers operate in many applications on feeds with high clay content, and are commonly used for difficult ore and stone washing duties. A few specified applications of Sepro Scrubbers include removal of gold “robbing” carboniferous material and other contaminants from gold ores, the processing of bauxite ores for aluminum production, the washing of laterites (gold, nickel, cobalt) to liberate fine metals for gravity recovery, and the washing of crushed aggregate, gravel and sand to remove clay contamination. | 0 | Metallurgy |
Gas phase coating is carried out at higher temperatures, about 1080 °C. The coating material is usually loaded onto trays without physical contact with the parts to be coated. The coating mixture contains active coating material and activator, but usually not thermal ballast. As in the pack cementation process, gaseous aluminium chloride (or fluoride) is transferred to the surface of the part. However, in this case the diffusion is outwards. This kind of coating also requires diffusion heat treatment. | 0 | Metallurgy |
* [https://www.wikidata.org/wiki/Q101294270 Васина Т. А.] Формирование горнозаводских округов в конце XVIII — первой половине XIX веков на территории современной Удмуртии // Научный диалог — 2019. — вып. 7. — С. 222—239. — ISSN 2227-1295 — [https://www.nauka-dialog.ru/jour/article/view/1254 doi:10.24224/2227-1295-2019-7-222-239]
* Запарий В. В. [https://cyberleninka.ru/article/n/predystoriya-sozdaniya-metallurgii-na-urale|Предыстория создания металлургии на Урале] // Историко-экономические исследования : журнал. — Иркутск: Федеральное государственное бюджетное образовательное учреждение высшего образования «Байкальский государственный университет», 2015. — Т. 16, № 2. — С. 349—365. — ISSN 2308-2488. — doi:10.17150/2308-2588.2015.16(2).349-365.
* Запарий В. В. [https://cyberleninka.ru/article/n/metallurgiya-urala-v-epohu-potryaseniy-pervaya-mirovaya-i-grazhdanskaya-voyny Металлургия Урала в эпоху потрясений Первая мировая и Гражданская войны] // Историко-экономические исследования : журнал. — Иркутск: Федеральное государственное бюджетное образовательное учреждение высшего образования «Байкальский государственный университет», 2015. — Т. 16, № 1. — С. 67—108. — ISSN 2308-2488. — doi:10.17150/2308-2588.2015.16(1).67-108.
* Запарий В. В. [https://cyberleninka.ru/article/n/petrovskaya-modernizatsiya-i-metallurgiya-urala-1700-1725 Петровская модернизация и металлургия Урала (1700–1725)] // Историко-экономические исследования : журнал. — Иркутск: Федеральное государственное бюджетное образовательное учреждение высшего образования «Байкальский государственный университет», 2016. — Т. 17, № 1. — С. 95—140. — ISSN 2308-2488. — doi:10.17150/2308-2588.2016.17(1).95-140.
* Мударисов Р. З. [https://elar.urfu.ru/handle/10995/64248 К вопросу о кризисе горнозаводской промышленности Южного Урала в первой половине XIX века] // Урал индустриальный. Бакунинские чтения. Индустриальная модернизация России в XVIII–XXI вв.: материалы XIII Всероссийской научной конференции, Екатеринбург, 18—19 октября 2018 г.: в 2-х томах. — Екатеринбург: УрО РАН, 2018. — Т. 1. — С. 63—72. — ISBN 978-5-7691-2504-1.
* Пыхалов И. В. [https://cyberleninka.ru/article/n/razvitie-chyornoy-metallurgii-v-rossiyskoy-imperii Развитие чёрной металлургии в Российской империи] // Проблемы современной экономики : журнал. — СПб.: ООО «Научно-производственная компания «РОСТ», 2017. — № 1 (61). — С. 95—140. — ISSN 1818-3395. | 0 | Metallurgy |
Eukaryotic RNA must undergo a series of modifications in order to be exported from the nucleus and successfully translated into function proteins, many of which are dependent on mRNA capping, the first mRNA modification to take place. 5 capping is essential for mRNA stability, enhancing mRNA processing, mRNA export and translation. After successful capping, an additional phosphorylation event initiates the recruitment of machinery necessary for RNA splicing, a process by which introns are removed to produce a mature mRNA. The addition of the cap onto mRNA confers protection to the transcript from exonucleases that degrade unprotected RNA and assist in the nuclear export transport process so that the mRNA can be translated to form proteins. The function of the 5 cap is essential to the ultimate expression of the RNA. | 1 | Gene expression + Signal Transduction |
When replicating its (+)ssRNA genome, the poliovirus RdRp is able to carry out recombination. Recombination appears to occur by a copy choice mechanism in which the RdRp switches (+)ssRNA templates during negative strand synthesis. Recombination frequency is determined in part by the fidelity of RdRp replication. RdRp variants with high replication fidelity show reduced recombination, and low fidelity RdRps exhibit increased recombination. Recombination by RdRp strand switching also occurs frequently during replication in the (+)ssRNA plant carmoviruses and tombusviruses. | 1 | Gene expression + Signal Transduction |
*RPL5
*RPL8
*RPL9
*RPL10A
*RPL11
*RPL14
*RPL25
*RPL26L1
*RPL27
*RPL30
*RPL32
*RPL34
*RPL35
*RPL35A
*RPL36AL
*RPS5
*RPS6
*RPS6KA3
*RPS6KB1
*RPS6KB2
*RPS13
RPS19BP1
*RPS20
*RPS23
*RPS24
*RPS27 transcribed with ubiquitin (see FAU (gene))
*RPN1 Ribophorin anchors the ribosome to rough endoplasmic reticulum | 1 | Gene expression + Signal Transduction |
In nerve terminals, synaptic vesicles are produced quickly to compensate for their rapid depletion during neurotransmitter release. Their biogenesis involves segregating synaptic vesicle membrane proteins from other cellular proteins and packaging those distinct proteins into vesicles of appropriate size. Besides, it entails the endocytosis of synaptic vesicle membrane proteins from the plasma membrane.
Synaptoblastic and synaptoclastic refer to synapse-producing and synapse-removing activities within the biochemical signalling chain. This terminology is associated with the Bredesen Protocol for treating Alzheimers disease, which conceptualizes Alzheimers as an imbalance between these processes. As of October 2023, studies concerning this protocol remain small and few results have been obtained within a standardized control framework. | 1 | Gene expression + Signal Transduction |
Thermal barrier coatings (TBCs) are used extensively in gas turbine engines to increase component life and engine performance. A coating of about 1-200 µm can reduce the temperature at the superalloy surface by up to 200 K. TBCs are a system of coatings consisting of a bond coat, a thermally grown oxide (TGO), and a thermally insulating ceramic top coat. In most applications, the bond coat is either a MCrAlY (where M=Ni or NiCo) or a Pt modified aluminide coating. A dense bond coat is required to provide protection of the superalloy substrate from oxidation and hot corrosion attack and to form an adherent, slow-growing surface TGO. The TGO is formed by oxidation of the aluminum that is contained in the bond coat. The current (first generation) thermal insulation layer is composed of 7wt % yttria-stabilized zirconia (7YSZ) with a typical thickness of 100–300 µm. Yttria-stabilized zirconia is used due to its low thermal conductivity (2.6W/mK for fully dense material), relatively high coefficient of thermal expansion, and high temperature stability. The electron beam-directed vapor deposition (EB-DVD) process used to apply the TBC to turbine airfoils produces a columnar microstructure with multiple porosity levels. Inter-column porosity is critical to providing strain tolerance (via a low in-plane modulus), as it would otherwise spall on thermal cycling due to thermal expansion mismatch with the superalloy substrate. This porosity reduces the thermal coating's conductivity. | 0 | Metallurgy |
Chemical messengers bind to metabotropic receptors to initiate a diversity of effects caused by biochemical signaling cascades. G protein-coupled receptors are all metabotropic receptors. When a ligand binds to a G protein-coupled receptor, a guanine nucleotide-binding protein, or G protein, activates a second messenger cascade which can alter gene transcription, regulate other proteins in the cell, release intracellular Ca, or directly affect ion channels on the membrane. These receptors can remain open from seconds to minutes and are associated with long-lasting effects, such as modifying synaptic strength and modulating short- and long-term synaptic plasticity.
Metabotropic receptors have a diversity of ligands, including but not limited to: small molecule transmitters, monoamines, peptides, hormones, and even gases. In comparison to fast-acting neurotransmitters, these ligands are not taken up again or degraded quickly. They can also enter the circulatory system to globalize a signal. Most metabotropic ligands have unique receptors. Some examples include: metabotropic glutamate receptors, muscarinic acetylcholine receptors, GABA receptors. | 1 | Gene expression + Signal Transduction |
The release of neurotransmitter is accomplished by the fusion of neurotransmitter vesicles to the presynaptic membrane. Although the details of this mechanism are still being studied there is a consensus on some details of the process. Synaptic vesicle fusion with the presynaptic membrane is known to require a local increase of calcium from as few as a single, closely associated calcium channels and the formation of highly stable SNARE complexes. One prevailing model of synaptic vesicle fusion is that SNARE complex formation is catalyzed by the proteins of the active zone such as Munc18, Munc13, and RIM. The formation of this complex is thought to "prime" the vesicle to be ready for vesicle fusion and release of neurotransmitter (see below: releasable pool). After the vesicle is primed then complexin binds to the SNARE complex this is called "superprimed". The vesicles that are superprimed are within the readily releasable pool (see below) and are ready to be rapidly released. The arrival of an action potential opens voltage gated calcium channels near the SNARE/complexin complex. Calcium then binds to change the conformation of synaptotagmin. This change in conformation of allows synaptotagmin to then dislodge complexin, bind to the SNARE complex, and bind to the target membrane. When synaptotagmin binds to both the SNARE complex and the membrane this induces a mechanical force on the membrane so that it causes the vesicle membrane and presynaptic membrane to fuse. This fusion opens a membrane pore that releases the neurotransmitter. The pore increases in size until the entire vesicle membrane is indistinguishable from the presynaptic membrane. | 1 | Gene expression + Signal Transduction |
The bioluminescent bacterium A. fischeri is the first organism in which QS was observed. It lives as a mutualistic symbiont in the photophore (or light-producing organ) of the Hawaiian bobtail squid. When A. fischeri cells are free-living (or planktonic), the autoinducer is at low concentration, and, thus, cells do not show luminescence. However, when the population reaches the threshold in the photophore (about cells/ml), transcription of luciferase is induced, leading to bioluminescence.
In A. fischeri bioluminescence is regulated by AHLs (N-acyl-homoserine lactones) which is a product of the LuxI gene whose transcription is regulated by the LuxR activator. LuxR works only when AHLs binds to the LuxR. | 1 | Gene expression + Signal Transduction |
The Dunaverney (1050–910 BC) and Little Thetford (1000–701 BC) flesh-hooks have been shown to be made using a lost-wax process. The Little Thetford flesh-hook, in particular, employed distinctly inventive construction methods. The intricate Gloucester Candlestick (1104–1113 AD) was made as a single-piece wax model, then given a complex system of gates and vents before being invested in a mould. | 0 | Metallurgy |
The core of the signal peptide contains a long stretch of hydrophobic amino acids (about 5–16 residues long) that has a tendency to form a single alpha-helix and is also referred to as the "h-region". In addition, many signal peptides begin with a short positively charged stretch of amino acids, which may help to enforce proper topology of the polypeptide during translocation by what is known as the positive-inside rule. Because of its close location to the N-terminus it is called the "n-region". At the end of the signal peptide there is typically a stretch of amino acids that is recognized and cleaved by signal peptidase and therefore named cleavage site. This cleavage site is absent from transmembrane-domains that serve as signal peptides, which are sometimes referred to as signal anchor sequences. Signal peptidase may cleave either during or after completion of translocation to generate a free signal peptide and a mature protein. The free signal peptides are then digested by specific proteases.
Moreover, different target locations are aimed by different types of signal peptides. For example, the structure of a target peptide aiming for the mitochondrial environment differs in terms of length and shows an alternating pattern of small positively charged and hydrophobic stretches. Nucleus aiming signal peptides can be found at both the N-terminus and the C-terminus of a protein and are in most cases retained in the mature protein.
It is possible to determine the amino acid sequence of the N-terminal signal peptide by Edman degradation, a cyclic procedure that cleaves off the amino acids one at a time. | 1 | Gene expression + Signal Transduction |
The introduction of atom into a crystal of atom creates a pinning point for multiple reasons. An alloying atom is by nature a point defect, thus it must create a stress field when placed into a foreign crystallographic position, which could block the passage of a dislocation. However, it is possible that the alloying material is approximately the same size as the atom that is replaced, and thus its presence would not stress the lattice (as occurs in cobalt alloyed nickel). The different atom would, though, have a different elastic modulus, which would create a different terrain for the moving dislocation. A higher modulus would look like an energy barrier, and a lower like an energy trough – both of which would stop its movement. | 0 | Metallurgy |
MIM signed the first ISASMELT licence agreement with Agip Australia Proprietary Limited ("Agip") in July 1990. Agip, a subsidiary of the Italian oil company ENI, was developing the Radio Hill nickel-copper deposit near Karratha in Western Australia. MIM and representatives of Agip conducted a series of trials in which 4 tonnes of Radio Hill concentrate was smelted in the 250 kg/h test rig at Mount Isa.
The Agip ISASMELT plant was designed to treat 7.5 t/h of the Radio Hill concentrate and produce 1.5 t/h of granulated matte with a combined nickel and copper content of 45% for sale., It was the same size as the copper ISASMELT demonstration plant (2.3 m internal diameter) and had a 5.5 Nm3/s blower to provide the lance air. Commissioning of the plant began in September 1991; however, the Radio Hill mine and smelter complex were forced to close by low nickel prices after less than six months, before commissioning was completed. The ISASMELT furnace achieved its design capacity within three months. Subsequent owners of the mine focussed on mining and mineral processing only, and the ISASMELT plant has been dismantled. | 0 | Metallurgy |
Degrading concrete has been the focus of many studies and the most obvious sign is calcium-rich leachate seeping from a concrete structure.
Calthemite stalactites can form on concrete structures and "artificial caves" lined with concrete (e.g. mines and tunnels) significantly faster than those in limestone, marble or dolomite caves. This is because the majority of calthemites are created by chemical reactions which are different from normal "speleothem" chemistry.
Calthemites are usually the result of hyperalkaline solution (pH 9–14) seeping through a calcareous man-made structure until it comes into contact with the atmosphere on the underside of the structure, where carbon dioxide (CO) from the surrounding air facilitates the reactions to deposit calcium carbonate as a secondary deposit. CO is the reactant (diffuses into solution) as opposed to speleothem chemistry where CO is the product (degassed from solution).
It is most likely that the majority of calcium carbonate (CaCO) creating calthemites in shapes which, mimicking speleothems, is precipitated from solution as calcite as opposed to the other, less stable, polymorphs of aragonite and vaterite.
Calthemites are generally composed of calcium carbonate (CaCO) which is predominantly coloured white, but may be coloured red, orange or yellow due to iron oxide (from rusting reinforcing) being transported by the leachate and deposited along with the CaCO. Copper oxide from copper pipes may cause calthemites to be coloured green or blue. Calthemites may also contain minerals such as gypsum.
The definition of calthemites also includes secondary deposits which may occur in manmade mines and tunnels with no concrete lining, where the secondary deposit is derived from limestone, dolomite or other calcareous natural rock into which the cavity has been hollowed out. In this instance the chemistry is the same as that which creates speleothems in natural limestone caves (equations 5 to 8) below. It has been suggested the deposition of calthemite formations are one example of a natural process which has not previously occurred prior to the human modification of the Earth's surface, and therefore represents a unique process of the Anthropocene. | 0 | Metallurgy |
The replication of technique in copper production includes a vast number of possibilities in trying to recreate what has been found through archaeological excavation. Tylecote and Boydell have experimented on possible explanations for the levels of iron found in certain copper objects and the possibility of removing excess iron through the re-melting of the copper. Crew has also done experimental work on iron to show possible loss in iron mass due to the processes involved with working the metal from bloom to billet which concluded with a loss of 75% in slag, impurities, and iron metal. | 0 | Metallurgy |
This class is defined by loss of two beta-strands and additional N-terminal strands. Both namesakes of this superfamily, myosin and kinesin, have shifted to use ATP. | 1 | Gene expression + Signal Transduction |
Trommel screens have a rotating drum on a shallow angle with screen panels around the diameter of the drum. The feed material always sits at the bottom of the drum and, as the drum rotates, always comes into contact with clean screen. The oversize travels to the end of the drum as it does not pass through the screen, while the undersize passes through the screen into a launder below. | 0 | Metallurgy |
The lactose operon (lac operon) is an operon required for the transport and metabolism of lactose in E. coli and many other enteric bacteria. Although glucose is the preferred carbon source for most enteric bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available through the activity of beta-galactosidase. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes for this reason. This lactose metabolism system was used by François Jacob and Jacques Monod to determine how a biological cell knows which enzyme to synthesize. Their work on the lac operon won them the Nobel Prize in Physiology in 1965.
Most bacterial cells including E. coli lack introns in their genome. They also lack a nuclear membrane. Hence the gene regulation by lac operon occurs at the transcriptional level, by preventing conversion of DNA into mRNA.
Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. In this case, when lactose is required as a sugar source for the bacterium, the three genes of the lac operon can be expressed and their subsequent proteins translated: lacZ, lacY, and lacA. The gene product of lacZ is β-galactosidase which cleaves lactose, a disaccharide, into glucose and galactose. lacY encodes β-galactoside permease, a membrane protein which becomes embedded in the Plasma membrane to enable the cellular transport of lactose into the cell. Finally, lacA encodes β-galactoside transacetylase.
Note that the number of base pairs in diagram given above are not for scale.
It would be wasteful to produce enzymes when no lactose is available or if a preferable energy source such as glucose were available. The lac operon uses a two-part control mechanism to ensure that the cell expends energy producing the enzymes encoded by the lac operon only when necessary.
In the absence of lactose, the lac repressor, encoded by lacI, halts production of the enzymes and transport proteins encoded by the lac operon. It does so by blocking the DNA dependent RNA polymerase. This blocking/ halting is not perfect, and a minimal amount of gene expression does take place all the time. The repressor protein is always expressed, but the lac operon (enzymes and transport proteins) are repressed. (But not completely stopped)
When lactose is available but not glucose, then some lactose enters the cell using pre-existing transport protein encoded by lacY. This lactose then combines with the repressor and inactivates it, hence allowing the lac operon to be expressed. Then more β-galactoside permease is synthesized allowing even more lactose to enter and the enzymes encoded by lacZ and lacA can digest it.
However, In the presence of glucose, regardless of the presence of lactose, the operon will be repressed. This is because the catabolite activator protein (CAP), required for production of the enzymes, remains inactive, and EIIA shuts down lactose permease to prevent transport of lactose into the cell. This dual control mechanism causes the sequential utilization of glucose and lactose in two distinct growth phases, known as diauxie. | 1 | Gene expression + Signal Transduction |
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