text
stringlengths 105
13.7k
| label
int64 0
1
| label_text
stringclasses 2
values |
|---|---|---|
Autoreceptor inhibition leads to increase respective neurotransmitter release. Major autoreceptor which clinically important are alpha 2(adrenergic receptor subtype 2), H 3(histamine receptor subtype 3), 5 HT 1(serotonin receptor subtype 1). In which respective drugs act are Clonidine on alpha 2 as Agonist used in hypertension which reduce release of norepinephrine and epinephrine from presynaptic neurons. Tizanidine used as centrally acting skeletal muscle relaxant is also act on alpha 2. 5 HT 1A is target of Buspirone which act as a partial Agonist and used as Atypical non sedative anxiolytic.5HT 1B/1D receptor Agonist are Triptans and Ergot alkaloids which used in treatment of migraine. 5 HT 1F receptor subtype Agonist drug lesmiditan also used in treatment of migraine. H 3 receptor antagonist Pitolisant used in narcolepsy. As an example, norepinephrine released from sympathetic neurons may interact with the alpha-2A and alpha-2C adrenoreceptors to inhibit further release of norepinephrine. Similarly, acetylcholine released from parasympathetic neurons may interact with M and M receptors to inhibit further release of acetylcholine. An atypical example is given by the β-adrenergic autoreceptor in the sympathetic peripheral nervous system, which acts to increase transmitter release.
The D2sh autoreceptor has been shown recently to interact with the trace amine-assorted receptor 1 (TAAR1), a G-Coupled Protein Receptor GPCR, to regulate monoaminergic systems in the brain. Active TAAR1 opposes the autoreceptor's activity by inactivating the dopamine transporter (DAT). In their review of TAAR1 in monoaminergic systems, Xie and Miller proposed this schematic: synaptic dopamine binds to the dopamine autoreceptor, which activates the DAT. Dopamine enters the presynaptic cells and binds to TAAR1, which increases adenylyl cyclase activity. This eventually allows for the translation of trace amines in the cytoplasm and activation of cyclic nucleotide-gated ion channels, which further activate TAAR1 and dump dopamine into the synapse. Through a series of phosphorylation events related to PKA and PKC, active TAAR1 inactivates DAT, preventing uptake of dopamine from the synapse. The presence of two Postsynaptic receptors with opposite abilities to regulate monoamine transporter function allows for regulation of the monoaminergic system.
Autoreceptor activity may also decrease paired-pulse facilitation (PPF). A feedback cell is activated by the (partially) depolarized post-synaptic neuron. The feedback cell releases a neurotransmitter to which the autoreceptor of the presynaptic neuron is receptive. The autoreceptor causes the inhibition of calcium channels (slowing calcium ion influx) and the opening of potassium channels (increasing potassium ion efflux) in the presynaptic membrane. These changes in ion concentration effectively diminish the amount of the original neurotransmitter released by the presynaptic terminal into the synaptic cleft. This causes a final depression on the activity of the postsynaptic neuron. Thus the feedback cycle is complete. | 1 | Gene expression + Signal Transduction |
Tinning is the process of thinly coating sheets of wrought iron or steel with tin, and the resulting product is known as tinplate. The term is also widely used for the different process of coating a metal with solder before soldering.
It is most often used to prevent rust, but is also commonly applied to the ends of stranded wire used as electrical conductors to prevent oxidation (which increases electrical resistance), and to keep them from fraying or unraveling when used in various wire connectors like twist-ons, binding posts, or terminal blocks, where stray strands can cause a short circuit.
While once more widely used, the primary use of tinplate now is the manufacture of tin cans. Formerly, tinplate was used for cheap pots, pans, and other holloware. This kind of holloware was also known as tinware and the people who made it were tinplate workers.
The untinned sheets employed in the manufacture are known as black plates. They are now made of steel, either Bessemer steel or open-hearth. Formerly iron was used, and was of two grades, coke iron and charcoal iron; the latter, being the better, received a heavier coating of tin, and this circumstance is the origin of the terms coke plates and charcoal plates by which the quality of tinplate is still designated, although iron is no longer used. Tinplate was consumed in enormous quantities for the manufacture of the tin cans in which preserved meat, fish, fruit, biscuits, cigarettes, and numerous other products are packed, and also for the household utensils of various kinds made by the tinsmith. | 0 | Metallurgy |
Multiple isoforms of the Fas receptor protein are produced by alternative splicing. Two normally occurring isoforms in humans are produced by an exon-skipping mechanism. An mRNA including exon 6 encodes the membrane-bound form of the Fas receptor, which promotes apoptosis, or programmed cell death. Increased expression of Fas receptor in skin cells chronically exposed to the sun, and absence of expression in skin cancer cells, suggests that this mechanism may be important in elimination of pre-cancerous cells in humans. If exon 6 is skipped, the resulting mRNA encodes a soluble Fas protein that does not promote apoptosis. The inclusion or skipping of the exon depends on two antagonistic proteins, TIA-1 and polypyrimidine tract-binding protein (PTB).
* The 5' donor site in the intron downstream from exon 6 in the pre-mRNA has a weak agreement with the consensus sequence, and is not bound usually by the U1 snRNP. If U1 does not bind, the exon is skipped (see "a" in accompanying figure).
* Binding of TIA-1 protein to an intronic splicing enhancer site stabilizes binding of the U1 snRNP. The resulting 5 donor site complex assists in binding of the splicing factor U2AF to the 3 splice site upstream of the exon, through a mechanism that is not yet known (see b).
* Exon 6 contains a pyrimidine-rich exonic splicing silencer, ure6, where PTB can bind. If PTB binds, it inhibits the effect of the 5' donor complex on the binding of U2AF to the acceptor site, resulting in exon skipping (see c).
This mechanism is an example of exon definition in splicing. A spliceosome assembles on an intron, and the snRNP subunits fold the RNA so that the 5 and 3 ends of the intron are joined. However, recently studied examples such as this one show that there are also interactions between the ends of the exon. In this particular case, these exon definition interactions are necessary to allow the binding of core splicing factors prior to assembly of the spliceosomes on the two flanking introns. | 1 | Gene expression + Signal Transduction |
Viral/prokaryotic RNA-directed RNA polymerases, along with many single-subunit DNA-directed polymerases, employ a fold whose organization has been linked to the shape of a right hand with three subdomains termed fingers, palm, and thumb. Only the palm subdomain, composed of a four-stranded antiparallel beta sheet with two alpha helices, is well conserved among all of these enzymes. In RdRp, the palm subdomain comprises three well-conserved motifs (A, B, and C). Motif A (D-x(4,5)-D) and motif C (GDD) are spatially juxtaposed; the aspartic acid residues of these motifs are implied in the binding of Mg and/or Mn. The asparagine residue of motif B is involved in selection of ribonucleoside triphosphates over dNTPs and, thus, determines whether RNA rather than DNA is synthesized. The domain organization and the 3D structure of the catalytic centre of a wide range of RdRps, even those with a low overall sequence homology, are conserved. The catalytic center is formed by several motifs containing a number of conserved amino acid residues.
Eukaryotic RNA interference requires a cellular RNA-dependent RNA polymerase (c RdRp). Unlike the "hand" polymerases, they resemble simplified multi-subunit DNA-dependent RNA polymerases (DdRPs), specifically in the catalytic β/β subunits, in that they use two sets of double-psi β-barrels in the active site. QDE1 () in Neurospora crassa', which has both barrels in the same chain, is an example of such a c RdRp enzyme. Bacteriophage homologs of c RdRp, including the similarly single-chain DdRp yonO (), appear to be closer to c RdRps than DdRPs are. | 1 | Gene expression + Signal Transduction |
The Albion process is an atmospheric leaching process for processing zinc concentrate, refractory copper and refractory gold. The process is important because it is the most cost-effective method currently in use for extracting both the zinc and lead from concentrates that contain high lead levels (7% or greater). Zinc and lead often occur together and large remaining zinc deposits contain levels of lead that exceed what can be economically extracted through other techniques. The Albion process is not sensitive to the concentration grade and gives favorable recovery with both low grade and dirty concentrates. Environmental impact is also claimed to be mitigated using this technology because in contrast to other methods, sulfur dioxide is not emitted and less energy is consumed over all. | 0 | Metallurgy |
* Platyhelminthes (flatworms) and Nematoda (roundworms).
Code 14 differs from code 9 (the echinoderm and flatworm mitochondrial code) only by translating UAA to Tyr rather than STOP. A study in 2000 has found no evidence that the codon UAA codes for Tyr in the flatworms but other opinions exist. There are very few GenBank records that are translated with code 14 but a test translation shows that re-translating these records with code 9 can cause premature terminations. More recently, UAA has been found to code for tyrosine in the nematodes Radopholus similis and Radopholus arabocoffeae. | 1 | Gene expression + Signal Transduction |
Bainite can essentially be regarded as martensite that tempers during the course of transformation. It forms at a higher temperature than martensite, and even the latter can autotemper. Because the transformation temperature is higher, the austenite itself is mechanically weak so that the shape deformation due to bainite is relaxed by the plastic deformation of the adjacent austenite. As a consequence, the growing plate of bainite is confronted by a forest of dislocations that eventually terminates its growth even before the plate has hit an austenite grain boundary. Plates of bainite can therefore be smaller than those of martensite in the same steel. The transformation then proceeds by a sub-unit mechanism involving the successive nucleation of new plates. | 0 | Metallurgy |
Chelating agents, natural zeolite, activated carbon, resins, and liquid organics impregnated with chelating agents are all used to exchange cations or anions with the solution. Selectivity and recovery are a function of the reagents used and the contaminants present. | 0 | Metallurgy |
In bacteria, such as E. coli, genes, are regulated by sequence elements in promoters and related binding sites). RegulonDB provides a database of such regulatory elements, their binding sites and the transcription factors that bind to these sites in E. coli. RegulonDB 9.0 includes 184 experimentally determined transcription factors (TFs) as well as 120 computationally predicted TFs, that is, a total of 304.
The complete repertoire of 189 genetic sensory-response units (GENSOR units) are reported, integrating their signal, regulatory interactions, and metabolic pathways. A total of 78 GENSOR units have their four components highlighted; 119 include the genetic switch and the response, and 2 contain only the genetic switch.
A total of 103 TFs have a known effector in RegulonDB, including 25 two-component systems. There were enough sites to build a motif for 93 TFs to infer 16,207 predicted TF binding sites. This set of predicted binding sites corresponds to 12,574 TF → gene regulatory interactions; this represents a recovery of 52% of the 1592 annotated regulatory interactions in the database for the 93 TFs for which RegulonDB has a position-weight matrix (PWM). If only TFs with a good-quality PWM are taken into account, the total number of predicted TF → gene interactions is 8,714, recovering 672 (57%) of annotated interactions for this TF subset. Semi-automatic curation produced a total of 3,195 regulatory interactions for 199 TFs. | 1 | Gene expression + Signal Transduction |
Beryllides of cobalt and nickel have metallurgical importance as the precipitated phase in beryllium copper alloys. These materials are nonsparking, which allows them to be used in certain hazardous environments.
In nuclear technology, beryllides are investigated as neutron multipliers. Unlike metallic Be, materials such as BeTi are more resistant to oxidation by water but retain the neutron-multiplying properties of the predominant isotope Be. | 0 | Metallurgy |
In general terms, chemotaxis is a biological process where living entities, such as cells or organisms, detect, maneuver, and react in response to a chemical signal in their environment. Such a phenomenon is critical for many biological processes, including but not limited to wound healing, detection of food, and avoidance of many toxins. Chemotaxis also plays an essential role in serval diseases, such as tumor metastasis, the recruitment of T-lymphocytes during inflammation, and HIV-1 entry into T cells. At the core of chemotaxis are specialized sensory cells called chemoreceptors. These cells allow an organism to detect chemical molecules within its environment and respond accordingly. Such chemical molecules are either known as chemoattractants or chemorepellents, which play a crucial role in attracting or repelling the organism towards or away from the source of the chemical signal, respectively. Thus, with this natural process of chemotaxis in mind, researchers have sought to apply the same phenomenon to targeted drug delivery, a medical technique aimed at delivering drugs to a specific cell, tissue, or organ within the body while minimizing its disruptive effects on healthy tissue. By using both chemotaxes to help guide the drug delivery process, researchers aim to reduce toxicity by avoiding healthy tissues, improve drug efficacy by focusing only on the intended site, and decrease drug dosage by delivering the directly rather than throughout the whole body. | 1 | Gene expression + Signal Transduction |
Crack growth is reported to be very slow by Luxfer, a major manufacturer of aluminium high-pressure cylinders. Cracks are reported to develop over periods in the order of 8 or more years before reaching a stage where the cylinder is likely to leak, which allows timely detection by properly trained inspectors using eddy-current crack-detection equipment.
SLC cracks have been detected in cylinders produced by several manufacturers, including Luxfer, Walter Kidde, and CIG gas cylinders.
Most of the cracking has been observed in the neck and shoulder areas of cylinders, though some cracks in the cylindrical part have also been reported. | 0 | Metallurgy |
In 1780, Luigi Galvani discovered that when two different metals (e.g., copper and zinc) are in contact and then both are touched at the same time to two different parts of a muscle of a frog leg, to close the circuit, the frogs leg contracts. He called this "animal electricity". The frogs leg, as well as being a detector of electrical current, was also the electrolyte (to use the language of modern chemistry).
A year after Galvani published his work (1790), Alessandro Volta showed that the frog was not necessary, using instead a force-based detector and brine-soaked paper (as electrolyte). (Earlier Volta had established the law of capacitance with force-based detectors). In 1799 Volta invented the voltaic pile, which is a stack of galvanic cells each consisting of a metal disk, an electrolyte layer, and a disk of a different metal. He built it entirely out of non-biological material to challenge Galvanis (and the later experimenter Leopoldo Nobili)s animal electricity theory in favor of his own metal-metal contact electricity theory. Carlo Matteucci in his turn constructed a battery entirely out of biological material in answer to Volta. Voltas contact electricity view characterized each electrode with a number that we would now call the work function of the electrode. This view ignored the chemical reactions at the electrode-electrolyte interfaces, which include H formation on the more noble metal in Voltas pile.
Although Volta did not understand the operation of the battery or the galvanic cell, these discoveries paved the way for electrical batteries; Volta's cell was named an IEEE Milestone in 1999.
Some forty years later, Faraday (see Faraday's laws of electrolysis) showed that the galvanic cell—now often called a voltaic cell—was chemical in nature. Faraday introduced new terminology to the language of chemistry: electrode (cathode and anode), electrolyte, and ion (cation and anion). Thus Galvani incorrectly thought the source of electricity (or source of electromotive force (emf), or seat of emf) was in the animal, Volta incorrectly thought it was in the physical properties of the isolated electrodes, but Faraday correctly identified the source of emf as the chemical reactions at the two electrode-electrolyte interfaces. The authoritative work on the intellectual history of the voltaic cell remains that by Ostwald.
It was suggested by Wilhelm König in 1940 that the object known as the Baghdad battery might represent galvanic cell technology from ancient Parthia. Replicas filled with citric acid or grape juice have been shown to produce a voltage. However, it is far from certain that this was its purpose—other scholars have pointed out that it is very similar to vessels known to have been used for storing parchment scrolls. | 0 | Metallurgy |
When choosing between inducing transient or stable expression in cells, time frame and experimental goal must be taken into consideration. Transiently transfected cells are often used to study the effects of short-term gene expression, perform RNA interference (RNAi)‑mediated gene silencing, or quickly generate small-scale recombinant proteins. This rapid generation small quantities of recombinant proteins can be applied towards evaluating their potential as drug candidates or examining their integrity of constructs during stages of vector development. Additionally, transient expression can be a useful tool when aiming to optimize selected parameters before undergoing the time-consuming process of scale-up in stably transfected cells. Typically, the cells are harvested within 1-4 days after successful transfection. For even quicker results, replacing DNA with mRNA can result in transient expression within minutes after successful transfection in some systems; this process bypasses translocation to the nucleus and transcription.
If stable, long-term gene expression is desired, stable transfection of cells is more useful. However, since successful integration of a DNA vector into the chromosome is a rare occurrence, this process is more difficult and time-consuming, and is reserved for large-scale protein production, gene therapies, and long-term pharmacology studies. | 1 | Gene expression + Signal Transduction |
The project is open source - all data and all software that is produced in the project can be freely accessed and used. | 1 | Gene expression + Signal Transduction |
Centromeres are the sites where spindle fibers attach to newly replicated chromosomes in order to segregate them into daughter cells when the cell divides. Each eukaryotic chromosome has a single functional centromere that is seen as a constricted region in a condensed metaphase chromosome. Centromeric DNA consists of a number of repetitive DNA sequences that often take up a significant fraction of the genome because each centromere can be millions of base pairs in length. In humans, for example, the sequences of all 24 centromeres have been determined and they account for about 6% of the genome. However, it is unlikely that all of this noncoding DNA is essential since there is considerable variation in the total amount of centromeric DNA in different individuals. Centromeres are another example of functional noncoding DNA sequences that have been known for almost half a century and it is likely that they are more abundant than coding DNA. | 1 | Gene expression + Signal Transduction |
Neurotransmitters bind to ionotropic receptors on postsynaptic neurons, either causing their opening or closing. The variations in the quantities of neurotransmitters released from the presynaptic neuron may play a role in regulating the effectiveness of synaptic transmission. In fact, the concentration of cytoplasmic calcium is involved in regulating the release of neurotransmitters from presynaptic neurons.
The chemical transmission involves several sequential processes:
# Synthesizing neurotransmitters within the presynaptic neuron.
# Loading the neurotransmitters into secretory vesicles.
# Controlling the release of neurotransmitters into the synaptic cleft.
# Binding of neurotransmitters to postsynaptic receptors.
# Ceasing the activity of the released neurotransmitters. | 1 | Gene expression + Signal Transduction |
Lowthian Bell (1816–1904) was, like Abraham Darby, the forceful patriarch of an ironmaking dynasty. Both his son Hugh Bell and his grandson Maurice Bell were directors of the Bell iron and steel company. His father, Thomas Bell, was a founder of Losh, Wilson and Bell, an iron and alkali company. The firm had works at Walker, near Newcastle upon Tyne, and at Port Clarence, Middlesbrough, contributing largely to the growth of those towns and of the economy of the northeast of England. Bell accumulated a large fortune, with mansions including Washington New Hall, Rounton Grange near Northallerton, and the mediaeval Mount Grace Priory near Osmotherley. | 0 | Metallurgy |
Riboses 2 hydroxy group reacts with the phosphate linked 3 hydroxy group, making RNA too unstable to be used or synthesized reliably. To overcome this, a ribose analogue can be used. The most common RNA analogues are 2-O-methyl-substituted RNA, locked nucleic acid (LNA) or bridged nucleic acid (BNA), morpholino, and peptide nucleic acid (PNA). Although these oligonucleotides have a different backbone sugar—or, in the case of PNA, an amino acid residue in place of the ribose phosphate—they still bind to RNA or DNA according to Watson and Crick pairing while being immune to nuclease activity. They cannot be synthesized enzymatically and can only be obtained synthetically using the phosphoramidite strategy or, for PNA, other methods of peptide synthesis. | 1 | Gene expression + Signal Transduction |
The Krupp-Renn process, which specialized in the beneficiation of poor ores, was the logical basis for the development of recycling processes for ferrous by-products. In 1957, Krupp tested a furnace at for the treatment of roasted pyrites to extract iron (in the form of Luppen) and zinc (vaporized in the flue gases). This process is therefore a hybrid of the Waelz and Krupp-Renn processes, which is why it is called the "Krupp-Waelz" (or "Renn-Waelz") process. The trials were limited to a single 2.75 m × 40 m demonstrator capable of processing 70 to 80 t/day and were not followed up.
The technical relationship between Krupp-Renn and Japanese direct reduction production processes is often cited. In the 1960s, Japanese steelmakers, sharing the observation that furnace plugging was difficult to control, developed their own low-temperature variants of the Krupp-Renn process. Kawasaki Steel commissioned a direct-reduction furnace at its (1968) and (1975) plants, the most visible feature of which was a pelletizing unit for the site's steelmaking by-products (sludge and dust from the cleaning of converter and blast furnace gases). The "Kawasaki process" also incorporates other developments, such as the combustion of oil instead of pulverized coal and the use of coke powder instead of coal mixed with ore... Almost identical to the Kawasaki process (with a more elaborate pelletizing unit), the "Koho process" was adopted by Nippon Steel, which commissioned a plant of this type at the in 1971. | 0 | Metallurgy |
Grinding is abrasion of the surface of interest by abrasive particles, usually diamond, that are bonded to paper or a metal disc. Grinding erases saw marks, coarsely smooths the surface, and removes stock to a desired depth. A typical grinding sequence for ceramics is one minute on a 240-grit metal-bonded diamond wheel rotating at 240 rpm and lubricated by flowing water, followed by a similar treatment on a 400-grit wheel. The specimen is washed in an ultrasonic bath after each step. | 0 | Metallurgy |
There are many theories on the kinetics of the bonding process but the most common theory divides the process into four main stages.
The stages are:
# dissolution of the interlayer
# homogenization of the liquid
# isothermal solidification
# homogenization of the bond region | 0 | Metallurgy |
There are several textures that are commonly found in processed (cubic) materials. They are named either by the scientist that discovered them, or by the material they are most found in. These are given in Miller indices for simplification purposes.
*Cube component: (001)[100]
*Brass component: (110)[-112]
*Copper component: (112)[11-1]
*S component: (123)[63-4] | 0 | Metallurgy |
Hot isostatic pressing (HIP) is a manufacturing process, used to reduce the porosity of metals and increase the density of many ceramic materials. This improves the material's mechanical properties and workability.
The process can be used to produce waste form classes. Calcined radioactive waste (waste with additives) is packed into a thin walled metal canister. The adsorbed gases are removed with high heat and the remaining material compressed to full density using argon gas during the heat cycle. This process can shrink steel canisters to minimize space in disposal containers and during transport. It was invented in the 1950s at the Battelle Memorial Institute and has been used to prepare nuclear fuel for submarines since the 1960s. It is used to prepare inactive ceramics as well, and the Idaho National Laboratory has validated it for the consolidation of radioactive ceramic waste forms. ANSTO (Australian Nuclear Science and Technology Organisation) is using HIP as part of a process to immobilize waste radionuclides from molybdenum-99 production.
The HIP process subjects a component to both elevated temperature and isostatic gas pressure in a high pressure containment vessel. The pressurizing gas most widely used is argon. An inert gas is used so that the material does not chemically react. The choice of metal can minimize negative effects of chemical reactions. Nickel, stainless or mild steel, or other metals can be chosen depending on the desired redox conditions. The chamber is heated, causing the pressure inside the vessel to increase. Many systems use associated gas pumping to achieve the necessary pressure level. Pressure is applied to the material from all directions (hence the term "isostatic").
For processing castings, metal powders can also be turned to compact solids by this method, the inert gas is applied between and , with being most common. Process soak temperatures range from for aluminium castings to for nickel-based superalloys. When castings are treated with HIP, the simultaneous application of heat and pressure eliminates internal voids and microporosity through a combination of plastic deformation, creep, and diffusion bonding; this process improves fatigue resistance of the component. Primary applications are the reduction of microshrinkage, the consolidation of powder metals, ceramic composites and metal cladding. Hot isostatic pressing is thus also used as part of a sintering (powder metallurgy) process and for fabrication of metal matrix composites,
often being used for postprocessing in additive manufacturing. | 0 | Metallurgy |
Ribosomal RNA (rRNA) includes non-coding RNAs that play essential roles in rRNA regulation. Ribosomal RNA (rRNA) takes part in protein synthesis. Occasional RNA molecules act catalytically, as RNA enzymes (ribozymes) or take part in protein export. The most important ribozyme is the major rRNA of the large subunit of the ribosome (28s rRNA in eukaryotes). It is now accepted that 28S rRNA catalyzes the critical step in polypeptide synthesis in addition to playing a major structural role. | 1 | Gene expression + Signal Transduction |
Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (FeO·nHO) and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)), and is typically associated with the corrosion of refined iron.
Given sufficient time, any iron mass, in the presence of water and oxygen, could eventually convert entirely to rust. Surface rust is commonly flaky and friable, and provides no passivational protection to the underlying iron, unlike the formation of patina on copper surfaces. Rusting is the common term for corrosion of elemental iron and its alloys such as steel. Many other metals undergo similar corrosion, but the resulting oxides are not commonly called "rust".
Several forms of rust are distinguishable both visually and by spectroscopy, and form under different circumstances. Other forms of rust include the result of reactions between iron and chloride in an environment deprived of oxygen. Rebar used in underwater concrete pillars, which generates green rust, is an example. Although rusting is generally a negative aspect of iron, a particular form of rusting, known as stable rust, causes the object to have a thin coating of rust over the top. If kept in low relative humidity, it makes the "stable" layer protective to the iron below, but not to the extent of other oxides such as aluminium oxide on aluminium. | 0 | Metallurgy |
The initiation time is related to the rate at which carbonation propagates in the concrete cover thickness. Once that carbonation reaches the steel surface, altering the local pH value of the environment, the protective thin film of oxides on the steel surface becomes instable, and corrosion initiates involving an extended portion of the steel surface. One of the most simplified and accredited models describing the propagation of carbonation in time is to consider penetration depth proportional to the square root of time, following the correlation
where is the carbonation depth, is time, and is the carbonation coefficient. The corrosion onset takes place when the carbonation depth reaches the concrete cover thickness, and therefore can be evaluated as
where is the concrete cover thickness.
is the key design parameter to assess initiation time in the case of carbonation-induced corrosion. It is expressed in mm/year and depends on the characteristics of concrete and the exposure conditions. The penetration of gaseous CO in a porous medium such as concrete occurs via diffusion. The humidity content of concrete is one of the main influencing factors of CO diffusion in concrete. If concrete pores are completely and permanently saturated (for instance in submerged structures) CO diffusion is prevented. On the other hand, for completely dry concrete, the chemical reaction of carbonation cannot occur. Another influencing factor for CO diffusion rate is concrete porosity. Concrete obtained with higher w/c ratio or obtained with an incorrect curing process presents higher porosity at hardened state, and is therefore subjected to a higher carbonation rate. The influencing factors concerning the exposure conditions are the environmental temperature, humidity and concentration of CO. Carbonation rate is higher for environments with higher humidity and temperature, and increases in polluted environments such as urban centres and inside close spaces as tunnels.
To evaluate propagation time in the case of carbonation-induced corrosion, several models have been proposed. In a simplified but commonly accepted method, the propagation time is evaluated as function of the corrosion propagation rate. If the corrosion rate is considered constant, t can be estimated as:
where is the limit corrosion penetration in steel and is the corrosion propagation rate.
must be defined in function of the limit state considered. Generally for carbonation-induced corrosion the concrete cover cracking is considered as limit state, and in this case a equal to 100 μm is considered. depends on the environmental factors in proximity of the corrosion process, such as the availability of oxygen and water at concrete cover depth. Oxygen is generally available at the steel surface, except for submerged structures. If pores are constantly fully saturated, a very low amount of oxygen reaches the steel surface and corrosion rate can be considered negligible. For very dry concretes is negligible due to the absence of water which prevents the chemical reaction of corrosion. For intermediate concrete humidity content, corrosion rate increases with increasing the concrete humidity content. Since the humidity content in a concrete can significantly vary along the year, it is general not possible to define a constant . One possible approach is to consider a mean annual value of . | 0 | Metallurgy |
Typical coatings that can be evaluated with this method are:
*Phosphated (pre-treated) surfaces (with subsequent paint/primer/lacquer/rust preventive)
*Zinc and zinc-alloy plating (see also electroplating). See ISO 4042 for guidance
*Electroplated chromium, nickel, copper, tin
*Coatings not applied electrolytically, such as zinc flake coatings according to ISO 10683
*Organic coatings, such as rust preventives
*Paint Coating
Hot-dip galvanized surfaces are not generally tested in a salt spray test (see ISO 1461 or ISO 10684). Hot-dip galvanizing produces zinc carbonates when exposed to a natural environment, thus protecting the coating metal and reducing the corrosion rate. The zinc carbonates are not produced when a hot-dip galvanized specimen is exposed to a salt spray fog, therefore this testing method does not give an accurate measurement of corrosion protection. ISO 9223 gives the guidelines for proper measurement of corrosion resistance for hot-dip galvanized specimens.
Painted surfaces with an underlying hot-dip galvanized coating can be tested according to this method. See ISO 12944-6.
Testing periods range from a few hours (e.g. 8 or 24 hours of phosphated steel) to more than a month (e.g. 720 hours of zinc-nickel coatings, 1000 hours of certain zinc flake coatings). | 0 | Metallurgy |
Non-stop decay (NSD) is a cellular pathway that identifies and degrades aberrant mRNA transcripts that do not contain a proper stop codon. Stop codons are signals in messenger RNA that signal for synthesis of proteins to end. Aberrant transcripts are identified during translation when the ribosome translates into the poly A tail at the 3' end of mRNA. A non-stop transcript can occur when point mutations damage the normal stop codon. Moreover, some transcriptional events are more likely to preserve gene expression on a lower scale in particular states.
The NSD pathway discharges ribosomes that have stalled at the 3' end of mRNA and directs the mRNA to the exosome complex in eukaryotes or RNase R in bacteria. Once directed to their appropriate sites, the transcripts are then degraded. The NSD mechanism requires the interaction of RNA exosome with the Ski complex, a multi-protein structure that includes the Ski2p helicase and (notably) Ski7p. The combination of these proteins and subsequent complex formation activates the degradation of aberrant mRNAs. Ski7p is thought to bind the ribosome stalled at the 3’ end of the mRNA poly(A) tail and recruit the exosome to degrade the aberrant mRNA. However in mammalian cells, Ski7p is not found, and even the presence of the NSD mechanism itself has remained relatively unclear. The short splicing isoform of HBS1L (HBS1LV3) was found to be the long-sought after human homologue of Ski7p, linking the exosome and SKI complexes. Recently, it has been reported that NSD also occurs in mammalian cells, albeit through a slightly different system. In mammals, due to the absence of Ski7, the GTPase Hbs1, as well as its binding partner Dom34, were identified as potential regulators of decay. Together, Hbs1/Dom34 are capable of binding to the 3’ end of an mis-regulated mRNA, facilitating the dissociation of malfunctioning or inactive ribosomes in order to restart the process of translation. In addition, once the Hbs1/Dom34 complex has dissociated and recycled a ribosome, it has also been shown to recruit the exosome/Ski complex. | 1 | Gene expression + Signal Transduction |
Orthopoxviruses and some other nucleocytoplasmic large DNA viruses synthesize RNA using a virally encoded multi-subunit RNAP. They are most similar to eukaryotic RNAPs, with some subunits minified or removed. Exactly which RNAP they are most similar to is a topic of debate. Most other viruses that synthesize RNA use unrelated mechanics.
Many viruses use a single-subunit DNA-dependent RNAP (ssRNAP) that is structurally and mechanistically related to the single-subunit RNAP of eukaryotic chloroplasts (RpoT) and mitochondria (POLRMT) and, more distantly, to DNA polymerases and reverse transcriptases. Perhaps the most widely studied such single-subunit RNAP is bacteriophage T7 RNA polymerase. ssRNAPs cannot proofread.
B. subtilis prophage SPβ uses YonO, a homolog of the β+β′ subunits of msRNAPs to form a monomeric (both barrels on the same chain) RNAP distinct from the usual "right hand" ssRNAP. It probably diverged very long ago from the canonical five-unit msRNAP, before the time of the last universal common ancestor.
Other viruses use an RNA-dependent RNAP (an RNAP that employs RNA as a template instead of DNA). This occurs in negative strand RNA viruses and dsRNA viruses, both of which exist for a portion of their life cycle as double-stranded RNA. However, some positive strand RNA viruses, such as poliovirus, also contain RNA-dependent RNAP. | 1 | Gene expression + Signal Transduction |
Bidirectional transcription at enhancer sites generates comparatively shorter (0.5-2kb) and non-polyadenylated eRNAs. Enhancers that generate polyA- eRNAs have a chromatin signature with a higher H3K4me1/me3 ratio than 1D-eRNAs. In general, enhancer transcription and production of bidirectional eRNAs demonstrate a strong correlation of enhancer activity on gene transcription. | 1 | Gene expression + Signal Transduction |
The copper-bronze metallurgy in the Harappan civilization was widespread and had a high variety and quality. The early use of iron may have developed from the practice of copper-smelting. While there is to date no proven evidence for smelted iron in the Indus Valley civilization, iron ore and iron items have been unearthed in eight Indus Valley sites, some of them dating to before 2600 BCE. There remains the possibility that some of these items were made of smelted iron, and the term "kṛṣṇa-ayas" might possibly also refer to these iron items, even if they are not made of smelted iron.
Lothali copper is unusually pure, lacking the arsenic typically used by coppersmiths across the rest of the Indus valley. Workers mixed tin with copper for the manufacture of celts, arrowheads, fishhooks, chisels, bangles, rings, drills and spearheads, although weapon manufacturing was minor. They also employed advanced metallurgy in following the cire perdue technique of casting, and used more than one-piece moulds for casting birds and animals. They also invented new tools such as curved saws and twisted drills unknown to other civilizations at the time. | 0 | Metallurgy |
These second generation mTOR inhibitors bind to ATP-binding site in mTOR kinase domain required for the functions of both mTORC1 and mTORC2, and result in downregulation of mTOR signaling pathway. Due to PI3K and mTORC2 ability to regulate AKT phosphorylation, these two compounds play a key role in minimizing the feedback activation of AKT. | 1 | Gene expression + Signal Transduction |
An example of a repressor protein is the methionine repressor MetJ. MetJ interacts with DNA bases via a ribbon-helix-helix (RHH) motif. MetJ is a homodimer consisting of two monomers, which each provides a beta ribbon and an alpha helix. Together, the beta ribbons of each monomer come together to form an antiparallel beta-sheet which binds to the DNA operator ("Met box") in its major groove. Once bound, the MetJ dimer interacts with another MetJ dimer bound to the complementary strand of the operator via its alpha helices. AdoMet binds to a pocket in MetJ that does not overlap the site of DNA binding.
The Met box has the DNA sequence AGACGTCT, a palindrome (it shows dyad symmetry) allowing the same sequence to be recognized on either strand of the DNA. The junction between C and G in the middle of the Met box contains a pyrimidine-purine step that becomes positively supercoiled forming a kink in the phosphodiester backbone. This is how the protein checks for the recognition site as it allows the DNA duplex to follow the shape of the protein. In other words, recognition happens through indirect readout of the structural parameters of the DNA, rather than via specific base sequence recognition.
Each MetJ dimer contains two binding sites for the cofactor S-Adenosyl methionine (SAM) which is a product in the biosynthesis of methionine. When SAM is present, it binds to the MetJ protein, increasing its affinity for its cognate operator site, which halts transcription of genes involved in methionine synthesis. When SAM concentration becomes low, the repressor dissociates from the operator site, allowing more methionine to be produced. | 1 | Gene expression + Signal Transduction |
* The compressive residual stresses imparted by laser peening are precisely controlled both in location and intensity and can be applied to mitigate sharp transitions into tensile regions. Laser peening imparts deep compressive residual stresses on the order of 10 to 20 times deeper than conventional shot peening, making them significantly more beneficial at preventing SCC. Laser peening is widely used in the aerospace and power generation industries in gas fired turbine engines.
* Material Selection: Choosing the right material for a specific environment can help prevent SCC. Materials with higher resistance to corrosion and stress corrosion cracking should be used in corrosive environments. For example, using stainless steel instead of carbon steel in a marine environment can reduce the likelihood of SCC.
* Protective Coatings: Applying a protective coating or barrier can help prevent corrosive substances from coming into contact with the metal surface, thus reducing the likelihood of SCC. For example, using an epoxy coating on the interior surface of a pipeline can reduce the likelihood of SCC.
* Cathodic Protection: Cathodic protection is a technique used to protect metals from corrosion by applying a small electrical current to the metal surface. This technique can also help prevent SCC by reducing the corrosion potential of the metal.
* Environmental Controls: Controlling the environment around the metal can help prevent SCC. For example, reducing the temperature or acidity of the environment can help prevent SCC.
* Inspection and Maintenance: Regular inspections and maintenance can help detect SCC before it causes a failure. This includes visual inspections, non-destructive testing, and monitoring of environmental factors. | 0 | Metallurgy |
The enzyme rhodanase (thiosulfate sulfurtransferase) catalyzes the detoxification of cyanide ion by thiosulfate ion by transforming them into thiocyanate ion and sulfite ion:
Sodium thiosulfate has been considered as an empirical treatment for cyanide poisoning, along with hydroxocobalamin. It is most effective in a pre-hospital setting, since immediate administration by emergency personnel is necessary to reverse rapid intracellular hypoxia caused by the inhibition of cellular respiration, at complex IV.
It activates thiosulfate sulfurtransferase (TST) in mitochondria. TST is associated with protection against obesity and type II (insulin resistant) diabetes.
Thiosulfate can also work as electron donor for growth of bacteria oxidizing sulfur, such as Chlorobium limicola forma thiosulfatophilum. These bacteria use electrons from thiosulfate (and other sources) and carbon from carbon dioxide to synthesize carbon compounds through reverse Krebs cycle. | 0 | Metallurgy |
Terfenol-D, an alloy of the formula (x ≈ 0.3), is a magnetostrictive material. It was initially developed in the 1970s by the Naval Ordnance Laboratory in the United States. The technology for manufacturing the material efficiently was developed in the 1980s at Ames Laboratory under a U.S. Navy-funded program. It is named after terbium, iron (Fe), Naval Ordnance Laboratory (NOL), and the D comes from dysprosium. | 0 | Metallurgy |
Phosphorylation and dephosphorylation of hydroxyl groups belonging to neutral but polar amino acids such as serine, threonine, and tyrosine within specific target proteins is a fundamental part of the regulation of every physiologic process. Phosphorylation involves the covalent modification of the hydroxyl with a phosphate group through the nucleophilic attack of the alpha phosphate in ATP by the oxygen in the hydroxyl. Dephosphorylation involves removal of the phosphate group through a hydration reaction by addition of a molecule of water and release of the original phosphate group, regenerating the hydroxyl. Both processes are reversible and either mechanism can be used to activate or deactivate a protein. Phosphorylation of a protein produces many biochemical effects, such as changing its conformation to alter its binding to a specific ligand to increase or reduce its activity. Phosphorylation and dephosphorylation can be used on all types of substrates, such as structural proteins, enzymes, membrane channels, signaling molecules, and other kinases and phosphatases. The sum of these processes is referred to as phosphoregulation. The deregulation of phosphorylation can lead to disease. | 1 | Gene expression + Signal Transduction |
The principal technology is the cyanide process, in which gold is leached from the ore by treatment with a solution of cyanide. The first step is comminution (grinding) to increase surface area and expose the gold to the extracting solution. The extraction is conducted by dump leaching or heap leaching processes. Sodium cyanide is produced on a billion-ton/year scale mainly for this purpose. "Black cyanide", a carbon-contaminated form of calcium cyanide (Ca(CN)) is often used because it is cheap. The crude ore is washed with a c. 0.3% solution of cyanide in air, often repeatedly, and the aqueous extract is collected and refined further. Recovery from solution typically involves adsorption on activated carbon, the carbon in pulp process.
Thiosulfate leaching has been proven to be effective on ores with high soluble copper values or ores which experience preg-robbing.
Leaching through bulk leach extractable gold, or BLEG, is also a process that is used to test an area for gold concentrations where gold may not be immediately visible. | 0 | Metallurgy |
The solidifying behavior depends on the alloy composition. Pure metals solidify at a certain temperature, forming crystals of one phase. Eutectic alloys also solidify at a single temperature, all components precipitating simultaneously in so-called coupled growth. Non-eutectic compositions on cooling start to first precipitate the non-eutectic phase; dendrites when it is a metal, large crystals when it is an intermetallic compound. Such a mixture of solid particles in a molten eutectic is referred to as a mushy state. Even a relatively small proportion of solids in the liquid can dramatically lower its fluidity.
The temperature of total solidification is the solidus of the alloy, the temperature at which all components are molten is the liquidus.
The mushy state is desired where a degree of plasticity is beneficial for creating the joint, allowing filling larger gaps or being wiped over the joint (e.g. when soldering pipes). In hand soldering of electronics it may be detrimental as the joint may appear solidified while it is not yet. Premature handling of such joint then disrupts its internal structure and leads to compromised mechanical integrity. | 0 | Metallurgy |
PHLPP1 and 2 also dephosphorylate the hydrophobic motifs of two classes of the protein kinase C (PKC) family: the conventional PKCs and the novel PKCs. (The third class of PKCs, known as the atypicals, have a phospho-mimetic at the hydrophobic motif, rendering them insensitive to PHLPP.)
The PKC family of kinases consists of 10 isoforms, whose sensitivity to various second messengers is dictated by their domain structure. The conventional PKCs can be activated by calcium and diacylglycerol, two important mediators of G protein-coupled receptor signaling. The novel PKCs are activated by diacylglycerol but not calcium, while the atypical PKCs are activated by neither.
The PKC family, like Akt, plays roles in cell survival and motility. Most PKC isoforms are anti-apoptotic, although PKCδ (a novel PKC isoform) is pro-apoptotic in some systems.
Although PKC possesses the same phosphorylation sites as Akt, its regulation is quite different. PKC is constitutively phosphorylated, and its acute activity is regulated by binding of the enzyme to membranes. Dephosphorylation of PKC at the hydrophobic motif by PHLPP allows PKC to be dephosphorylated at two other sites (the activation loop and the turn motif). This in turn renders PKC sensitive to degradation. Thus, prolonged increases in PHLPP expression or activity inhibit PKC phosphorylation and stability, decreasing the total levels of PKC over time. | 1 | Gene expression + Signal Transduction |
STAT3 has been shown to interact with:
* AR,
* ELP2,
* EP300,
* EGFR,
* HIF1A,
* JAK1,
* JUN
* KHDRBS1,
* mTOR,
* MYOD1,
* NDUFA13,
* NFKB1,
* NR3C1,
* NCOA1,
* PML,
* RAC1,
* RELA,
* RET,
* RPA2,
* STAT1,
* Stathmin,
* Src, and
* TRIP10.
* KPNA4.
Niclosamide seems to inhibit the STAT3 signalling pathway.
Nicotinamide (a type of vitamin B) naturally inhibits STAT3. However NAC (Acetylcysteine) inhibits STAT3 inhibitors. | 1 | Gene expression + Signal Transduction |
Upregulation refers to the increase in the number of receptor sites on the membrane. Estrogen and FSH upregulate LHCGR sites in preparation for ovulation. After ovulation, the luteinized ovary maintains LHCGR s that allow activation in case there is an implantation. Upregulation in males requires gene transcription to synthesize LH receptors within the cell cytoplasm. Some reasons as to why downregulated LH receptors are not upregulated are: lack of gene transcription, lack of RNA to protein conversion and lack of cell membrane targeted shipments from Golgi. | 1 | Gene expression + Signal Transduction |
An application of dendritic growth in directional solidification is gas turbine engine blades which are used at high temperatures and must handle high stresses along the major axes. At high temperatures, grain boundaries are weaker than grains. In order to minimize the effect on properties, grain boundaries are aligned parallel to the dendrites. The first alloy used in this application was a nickel-based alloy (MAR M-200) with 12.5% tungsten, which accumulated in the dendrites during solidification. This resulted in blades with high strength and creep resistance extending along the length of the casting, giving improved properties compared to the traditionally-cast equivalent. | 0 | Metallurgy |
Currently, the stability of most ionic liquids under practical electrochemical conditions is unknown, and the fundamental choice of ionic fluid is still empirical as there is almost no data on metal ion thermodynamics to feed into solubility and speciation models. Also, there are no Pourbaix diagrams available, no standard redox potentials, and bare knowledge of speciation or pH-values. It must be noticed that most processes reported in the literature involving ionic fluids have a Technology Readiness Level (TRL) 3 (experimental proof-of-concept) or 4 (technology validated in the lab), which is a disadvantage for short-term implementation. However, ionometallurgy has the potential to effectively recover metals in a more selective and sustainable way, as it considers environmentally benign solvents, reduction of greenhouse gas emissions and avoidance of corrosive and harmful reagents. | 0 | Metallurgy |
Geometric Dynamic Recrystallization (GDR) is a recrystallization mechanism that has been proposed to occur in several alloys, particularly aluminium, at high temperatures and low strain rates. It is a variant of dynamic recrystallization.
The basic mechanism is that during deformation the grains will be increasingly flattened until the boundaries on each side are separated by only a small distance. The deformation is accompanied by the serration of the grain boundaries due to surface tension effects where they are in contact with low-angle grain boundaries belonging to sub-grains.
Eventually the points of the serrations will come into contact. Since the contacting boundaries are defects of opposite sign they are able to annihilate and so reduce the total energy in the system. In effect the grain will pinch in two new grains.
The grain size is known to decrease as the applied stress is increased. However, high stresses require a high strain rate and at some point statically recrystallized grains will begin to nucleate and consume the GDRX microstructure.
There are features that are unique to GDRX:
* The recrystallisation spreads throughout the specimen over a strain range (0.5-1 in Al-Mg-Mn alloys) without any change in flow stress. This is in contrast to discontinuous mechanisms where the flow stress normally decreases by ~25% as the recrystallized grains form.
* GDRX results in grains that are around 3 times the sub-grain size. Statically recrystallized grains are normally 20-30 times the sub-grain size. | 0 | Metallurgy |
In 1961, Israeli archaeologist Pessah Bar-Adon discovered a hoard of Chalcolithic artifacts in a cave on the northern side of Nahal Mishmar, known since as the Treasure Cave. The hoard consisted of 442 decorated objects made of copper and bronze (429 of them), ivory and stone, including 240 mace heads, about 100 scepters, 5 crowns, powder horns, tools and weapons. Archaeologist David Ussishkin has suggested the hoard was the cultic furniture of the abandoned Chalcolithic Temple of Ein Gedi. Prominent finds from the hoard are currently on display in the archaeology wing of the Israel Museum in Jerusalem.
Items in the hoard belong to the Ghassulian culture and the Nahal Mishmar hoard is the only hoard of this culture. It is probable that the copper used for producing them was mined in Wadi Feynan.
Due to the dry climate numerous textile and plaited remains were found at the site. The remains of over 20 individuals were found in the caves. They were members of a sedentary Chalcolithic population who became refugees and their lives ended under tragic circumstances which is indicated by the fact they had numerous injuries and that the wrappings were stained with blood.
Many of these copper objects were made using the lost-wax process, one of the earliest known uses of this complex technique. Carbon-14 dating of the reed mat which was used to wrap the objects points that it was used circa 3500 B.C.E. During this period the use of copper became widespread throughout the Levant which also led to social changes in the region. | 0 | Metallurgy |
The eFS assay could be used to analyze other cell or tissue types. By assessing enrichment in GFP-expressing CD2-negative as well as CD2-positive cells, and by crossing a common pool of reporter transformant male flies to females expressing CD2 in different cell types, it is possible to assay specificity as well as activity. Accelerating the annotation of the regulatory genome in Drosophila should in principle generate the kind of large-scale regulatory interaction data that would allow exploring the network properties of transcriptional regulation. | 1 | Gene expression + Signal Transduction |
Much of the SIMIBI class of GTPases is activated by dimerization. Named after the signal recognition particle (SRP), MinD, and BioD, the class is involved in protein localization, chromosome partitioning, and membrane transport. Several members of this class, including MinD and Get3, has shifted in substrate specificity to become ATPases. | 1 | Gene expression + Signal Transduction |
There has been a significant amount of work experimentally to observe both the structure and measure the properties of grain boundaries but the five dimensional degrees of freedom of grain boundaries within complex polycrystalline networks has not yet been fully understood and thus there is currently no method to control the structure and properties of most metals and alloys with atomic precision. Part of the problem is related to the fact that much of the theoretical work to understand grain boundaries is based upon construction of bicrystal (two) grains which do not represent the network of grains typically found in a real system and the use of classical force fields such as the embedded atom method often do not describe the physics near the grains correctly and density functional theory could be required to give realistic insights. Accurate modelling of grain boundaries both in terms of structure and atomic interactions could have the effect of improving engineering which could reduce waste and increase efficiency in terms of material usage and performance. From a computational point of view much of the research on grain boundaries has focused on bi-crystal systems, these are systems which only consider two grain boundaries. There has been recent work which has made use of novel grain evolution models which show that there are substantial differences in the material properties associated with whether curved or planar grains are present. | 0 | Metallurgy |
Biological probe or bio-probes are used to collect samples for microbiological analysis. Microorganisms can accelerate the corrosion process, so monitoring the corrosion caused by them is effective in timely notification and preventive measures. | 0 | Metallurgy |
Gene knockout by mutation is commonly carried out in bacteria. An early instance of the use of this technique in Escherichia coli was published in 1989 by Hamilton, et al. In this experiment, two sequential recombinations were used to delete the gene. This work established the feasibility of removing or replacing a functional gene in bacteria. That method has since been developed for other organisms, particularly research animals, like mice. Knockout mice are commonly used to study genes with human equivalents that may have significance for disease. An example of a study using knockout mice is an investigation of the roles of Xirp proteins in Sudden Unexplained Nocturnal Death Syndrome (SUNDS) and Brugada Syndrome in the Chinese Han Population. | 1 | Gene expression + Signal Transduction |
A coating is a covering that is applied to the surface of an object, or substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. powder coatings.
Paints and lacquers are coatings that mostly have dual uses, which are protecting the substrate and being decorative, although some artists paints are only for decoration, and the paint on large industrial pipes is for identification (e.g. blue for process water, red for fire-fighting control) in addition to preventing corrosion. Along with corrosion resistance, functional coatings may also be applied to change the surface properties of the substrate, such as adhesion, wettability, or wear resistance. In other cases the coating adds a completely new property, such as a magnetic response or electrical conductivity (as in semiconductor device fabrication, where the substrate is a wafer), and forms an essential part of the finished product.
A major consideration for most coating processes is controlling coating thickness. Methods of achieving this range from a simple brush to expensive precision machinery in the electronics industry. Limiting coating area is crucial in some applications, such as printing.
"roll-to-roll" or "web-based" coating is the process of applying a thin film of functional material to a substrate on a roll, such as paper, fabric, film, foil, or sheet stock. | 0 | Metallurgy |
Plithotaxis, from the Greek word "πλήΘος", denotes a crowd, swarm, or throng. In collective cellular migration, plithotaxis is the tendency for each individual cell within a monolayer to migrate along the local orientation of the maximal principal stress, or equivalently, minimal intercellular shear stress. Plithotaxis requires force transmission across many cell-cell junctions and therefore is an emergent property of the cell group.
Plithotaxis is found to hold at the level of both a subcellular grid point and an individual cell of a confluent monolayer, and the stresses must be tensile. | 1 | Gene expression + Signal Transduction |
The tin belt of Southeast Asia extends all the way down to Tasmania, but metals were not exploited in Australia until the arrival of Europeans in the 1780s. | 0 | Metallurgy |
Secreted frizzled-related protein 1 (SFRP1) is a member of the SFRP family that contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzled proteins. SFRPs act as soluble modulators of Wnt signaling. SFRP1 and SFRP5 may be involved in determining the polarity of photoreceptor cells in the retina. SFRP1 is expressed in several human tissues, with the highest levels in the heart.
The Secreted frizzled-related protein (SFRP) family consists of five secreted glycoproteins in humans (SFRP1, SFRP2, SFRP3, SFRP4, SFRP5) that act as extracellular signaling ligands. Each SFRP is ~300 amino acids in length and contains a cysteine-rich domain (CRD) that shares 30-50% sequence homology with the CRD of Frizzled (Fz) receptors. SFRPs are able to bind Wnt proteins and Fz receptors in the extracellular compartment. The interaction between SFRPs and Wnt proteins prevents the latter from binding the Fz receptors. SFRPs are also able to downregulate Wnt signaling by the formation of an inhibitory complex with the Frizzled receptors. The Wnt pathway plays a key role in embryonic development, cell differentiation and cell proliferation. It has been shown that the deregulation of this critical developmental pathway occurs in several human tumor entities.
SFRP1 is a 35 kDa prototypical member of the SFRP family. It acts as a biphasic modulator of Wnt signaling, counteracting Wnt-induced effects at high concentrations and promoting them at lower concentrations. It is located in a chromosomal region (8p12-p11.1) that is frequently deleted in breast cancer and is thought to harbour a tumor suppressor gene. | 1 | Gene expression + Signal Transduction |
Ariconium was a road station of Roman Britain mentioned in Iter XIII of the Iter Britanniarum of the Antonine Itineraries. It was located at Bury Hill in the parish of Weston under Penyard, about east of Ross on Wye, Herefordshire, and about southeast of Hereford. The site existed prior to the Roman era, and then came under Roman control. It was abandoned, perhaps shortly after 360, but precisely when and under what circumstances is unknown.
Discovered as a result of efforts to map the stations of the Antonine Itineraries, research and excavation have provided the only information on its history, to date showing it to have been a place of bloom furnaces, forges, and iron working throughout its existence. | 0 | Metallurgy |
Chemical metallurgy is the science of obtaining metals from their concentrates, semi products, recycled bodies and solutions, and of considering reactions of metals with an approach of disciplines belonging to chemistry. As such, it involves reactivity of metals and it is especially concerned with the reduction and oxidation, and the chemical performance of metals.
Subjects of study in chemical metallurgy include the extraction of metals, thermodynamics, electrochemistry, and chemical degradation (corrosion). | 0 | Metallurgy |
The name NANOG derives from Tír na nÓg (Irish for "Land of the Young"), a name given to the Celtic Otherworld in Irish and Scottish mythology. | 1 | Gene expression + Signal Transduction |
Removal of the chlorides is essential. In practice this first involves physical cleaning (with a wooden or even metal pick) to remove the bulk of the chlorides and then chemical treatment. One chemical treatment is soaking the object in a 5% sodium sesquicarbonate solution. This serves to neutralize the acid that attacks the metal as well as converting the reactive cuprous chloride to largely inert cuprous oxide. The oxide may coat the artefact with unsightly but harmless black spots or generally darken the metal.
The duration of soaking may be days to weeks or even a year for severely contaminated objects. The sesquicarbonate may remove copper from the artefact as it forms a complex ion with copper. Amateurs report that the patina may be stripped from the artefact but this is when the solution is boiled so that the carbonate rinse removes the chlorides in hours rather than the cool bath of long duration used by professional conservators.
Soaking in sodium carbonate—which does not form a complex ion with copper and is unlikely to affect the patina but is slower than the sesquicarbonate—or benzotriazole aqueous solutions may also be used. The carbonate is similar in effect to the sesquicarbonate. The benzotriazole does not remove the chlorides or neutralize the acid present but acts as a physical barrier to water, oxygen, and chlorides and so can be used as a final step in all cases but as a first or only step in only minor cases.
Use of tap water for initial carbonate rinses is fine as any chloride content in the water is low compared to the content found when the chlorides from the contaminated artefact have dissolved into the water. Later rinses should be with distilled water though the chlorine of a chlorinated town water supply is likely to have evaporated from tap water inside 24 hours and therefore will not further contaminate the object.
Instead of rinses, electrolysis may be used, often with sodium carbonate as the electrolyte and mild or stainless steel as the anode. This converts the cuprous ions to elemental copper. Elemental copper released from the chlorides may be redeposited on the artefact as a pinkish coating. A coin may take only hours, whereas a large artefact, such as a cannon, may take months.
Once treated, the specimen should be held in a dry environment and periodically inspected for recurrence of bronze disease as no long-term treatment has been confirmed. | 0 | Metallurgy |
Fretting decreases fatigue strength of materials operating under cycling stress. This can result in fretting fatigue, whereby fatigue cracks can initiate in the fretting zone. Afterwards, the crack propagates into the material. Lap joints, common on airframe surfaces, are a prime location for fretting corrosion. This is also known as frettage or fretting corrosion. | 0 | Metallurgy |
The candidate editing sites were determined experimentally by comparison of cDNA sequences and genomically encoded DNA from the same individual to avoid single nucleotide polymorphisms (SNPs). Two of the three editing sites found in mouse gene were found in the human transcript.
However, only the Q/R site was detected in all RNA, with the T/A site detected just once. Both sites are found within exon 1.
Q/R site
This site is found in exon 1 at position 66. Editing results in a codon change from a Glutamine codon to an Arginine codon.
T/A site
This site is also found in exon 1, at position 63. It was only detected in one genomic sample indicating that the edited residue may be an SNP. However, the secondary structure of the RNA is predicted, around the editing site, to be highly conserved in mice and humans. This indicates that the T/A site may still be shown to be a site of A to I RNA editing. Editing at this site would result in an amino acid change from a Threonine to an Alanine.
The ECS is also predicted to be found within exon 1 at a location 5' to the editing region. | 1 | Gene expression + Signal Transduction |
Permeability is a property of foundry sand with respect to how well the sand can vent, i.e. how well gases pass through the sand. And in other words, permeability is the property by which we can know the ability of material to transmit fluid/gases. The permeability is commonly tested to see if it is correct for the casting conditions. | 0 | Metallurgy |
Due to their extensive use, non-ferrous scrap metals are usually recycled. The secondary materials in scrap are vital to the metallurgy industry, as the production of new metals often needs them. Some recycling facilities re-smelt and recast non-ferrous materials; the dross is collected and stored onsite while the metal fumes are filtered and collected. Non-ferrous scrap metals are sourced from industrial scrap materials, particle emissions and obsolete technology (for example, copper cables) scrap. | 0 | Metallurgy |
Zinc-finger nucleases consist of DNA binding domains that can precisely target a DNA sequence. Each zinc-finger can recognize codons of a desired DNA sequence, and therefore can be modularly assembled to bind to a particular sequence. These binding domains are coupled with a restriction endonuclease that can cause a double stranded break (DSB) in the DNA. Repair processes may introduce mutations that destroy functionality of the gene. | 1 | Gene expression + Signal Transduction |
In the 1990s, the Niihama copper refinery, owned by Sumitomo Metal Mining Company Limited (“Sumitomo”), treated copper anode slimes generated in-house, together with anode slimes from Sumitomo’s Toyo refinery and lead refinery slime from the Harima Imperial Smelting Process smelter. A total of 1200 tonnes per year (“t/y”) of anode slimes and 400 t/y of lead refinery slimes were treated using a process flow sheet that included a chloridizing step to remove separate the lead as lead chloride (PbCl) and a reverberatory-type doré furnace. It produced about 200 t of silver, 22 t of gold, 1.5 t of palladium, 300 kilograms (“kg”) of platinum and 40 kg of rhodium, as well as 60 t of selenium, 50 t of bismuth, 900 kg of tellurium and 150 t of antimony alloy annually.
The gold production doubled during the decade to 1996, as its concentration in anode slimes and the quantity of anode slimes increased. To enable this, Sumitomo decided in 1990 to upgrade the refinery, and as part of that upgrade, installed a 3.5 t-capacity BBOC to replace its reverberatory doré furnace in October 1992.
Sumitomo reported that, while the old oil-fired reverberatory furnace had served it well for many years, it had the following drawbacks:
* its operation was labor-intensive
* it had a low fuel efficiency
* there was a high waste gas volume
* the reaction rate was low.
Sumitomo investigated both the TBRC and BBOC furnaces before making a selection. It chose the BBOC over the TBRC technology because of the ease of control of the bath temperature, its high oxygen efficiency and its simple maintenance.
Sumitomo found that the impurity contents of BBOC doré anodes was high when the furnace was first commissioned. This was because it was important to determine the endpoint of the oxidation reactions to maximize the quality of the anodes. Sumitomo found that this could be determined by measuring the oxygen content of the off-gas using oxygen sensors based on stabilized zirconia with an Fe/FeO reference electrode.
Sumitomo subsequently adapted the BBOC to allow the chloridizing step to be undertaken in the furnace, thus eliminating the need for a separate chloridizing furnace for lead chloride production. This was done in February 1994 and was reported to be “giving very good results.” | 0 | Metallurgy |
CCCTC-Binding factor or CTCF was initially discovered as a negative regulator of the chicken c-myc gene. This protein was found to be binding to three regularly spaced repeats of the core sequence CCCTC and thus was named CCCTC binding factor. | 1 | Gene expression + Signal Transduction |
A grain boundary (GB) is the transition area or interface between adjacent crystallites (or grains) of the same chemical and lattice composition, not to be confused with a phase boundary. The adjacent grains do not have the same orientation of the lattice, thus giving the atoms in GB shifted positions relative to the lattice in the crystals. Due to the shifted positioning of the atoms in the GB they have a higher energy state when compared with the atoms in the crystal lattice of the grains. It is this imperfection that makes it possible to selectively etch the GBs when one wants the microstructure to be visible.
Striving to minimize its energy leads to the coarsening of the microstructure to reach a metastable state within the specimen. This involves minimizing its GB area and changing its topological structure to minimize its energy. This grain growth can either be normal or abnormal, a normal grain growth is characterized by the uniform growth and size of all the grains in the specimen. Abnormal grain growth is when a few grains grow much larger than the remaining majority. | 0 | Metallurgy |
Geneticist Dean Hamer has suggested that a particular allele of the SLC18A2 gene correlates with spirituality using data from a smoking survey, which included questions intended to measure "self-transcendence". Hamer performed the spirituality study on the side, independently of the National Cancer Institute smoking study. His findings were published in the mass-market book The God Gene: How Faith Is Hard-Wired into Our Genes. Hamer himself notes that SLC18A2 plays at most a minor role in influencing spirituality. Furthermore, Hamers claim that the SLC18A2 gene contributes to spirituality is controversial. Hamers study has not been published in a peer-reviewed journal and a reanalysis of the correlation demonstrates that it is not statistically significant. | 1 | Gene expression + Signal Transduction |
The Westinghouse Lamp Plant located in Bloomfield, New Jersey, was one of the lamp manufacturing plants of Westinghouse Electric Corporation. The plant had a major involvement in supplying uranium metal for the world's first self-sustaining chain reaction in Chicago (Chicago Pile-1) in the early phase of the Manhattan Project to create the first atomic bomb. | 0 | Metallurgy |
There is an inverse relationship between delta yield strength and grain size to some power, x.
where k is the strengthening coefficient and both k and x are material specific. Assuming a narrow monodisperse grain size distribution in a polycrystalline material, the smaller the grain size, the smaller the repulsion stress felt by a grain boundary dislocation and the higher the applied stress needed to propagate dislocations through the material.
The relation between yield stress and grain size is described mathematically by the Hall–Petch equation:
where σ is the yield stress, σ is a materials constant for the starting stress for dislocation movement (or the resistance of the lattice to dislocation motion), k is the strengthening coefficient (a constant specific to each material), and d is the average grain diameter. It is important to note that the H-P relationship is an empirical fit to experimental data, and that the notion that a pileup length of half the grain diameter causes a critical stress for transmission to or generation in an adjacent grain has not been verified by actual observation in the microstructure.
Theoretically, a material could be made infinitely strong if the grains are made infinitely small. This is impossible though, because the lower limit of grain size is a single unit cell of the material. Even then, if the grains of a material are the size of a single unit cell, then the material is in fact amorphous, not crystalline, since there is no long range order, and dislocations can not be defined in an amorphous material. It has been observed experimentally that the microstructure with the highest yield strength is a grain size of about , because grains smaller than this undergo another yielding mechanism, grain boundary sliding. Producing engineering materials with this ideal grain size is difficult because only thin films can be reliably produced with grains of this size. In materials having a bi-disperse grain size distribution, for example those exhibiting abnormal grain growth, hardening mechanisms do not strictly follow the Hall–Petch relationship and divergent behavior is observed. | 0 | Metallurgy |
Copper extraction refers to the methods used to obtain copper from its ores. The conversion of copper ores consists of a series of physical, chemical and electrochemical processes. Methods have evolved and vary with country depending on the ore source, local environmental regulations, and other factors. | 0 | Metallurgy |
The Iron & Steel Museum of Alabama, also known as the Tannehill Museum, is an industrial museum that demonstrates iron production in the nineteenth-century Alabama located at Tannehill Ironworks Historical State Park in McCalla, Tuscaloosa County, Alabama. Opened in 1981, it covers .
The museum is an interpretive center focusing on 19th-century iron-making technology. It features an extensive collection of machinery and other iron industry artifacts spanning from the time of the American Civil War until the 1960s, including belt-driven machines, a reconstruction of an 1870s machine shop, and four steam engines. The collection also houses over ten thousand artifacts and other items sourced from archaeological digs at various iron-making sites in Alabama such as the Roupes Valley Ironworks, and from the Alabama Department of Archives and History, the Henry Ford Museum, and the Washington Navy Yard. The collection includes rare steam engines, forge cams and war materials manufactured at the CS Naval Gun Works at Selma, Alabama.
In the museum, the collections and displays feature both belt-driven machines and the nineteenth century iron-making tools and products. The museum preserves more than 10,000 historical relics, including collections from the Washington Navy Yard and the Henry Ford Museum, as well as rare iron-making machinery from the Tredegar Ironworks from Virginia. The displayed ironworks show how iron making developed during the period from the Civil war to the 1960s. By visiting the museum, visitors can understand how iron making in this area grows into the later Birmingham District. This site preserves and demonstrates thousands of artefacts from archaeological digs in this area, showing the previous human activities in Alabama from the end of the Civil war to the middle of the 20 centuries. On top of that, 16 slave cabins have also been unearthed on the site in more recent excavations. The museum is connected with the best preserved furnaces at Tannehill Ironworks by the Tram Track Hiking Trail. Various interactive displays are available in the museum, which can enable the visitors to go back into the historical environments in the nineteenth-century Alabama. Visitors can follow the timeline of industrial growth to trace how iron trade developed from the ancient Egypt to modern Fairfield Works in Birmingham. The Tannehill Learning Centre currently offers educational programmes and tours to school children in this region. Museum visitors are provided with field trips during the spring and fall.
The museum underwent a major renovation of its exhibits in 2004–05. The site also has a 30-seat theatre which plays a short video on the park's history. | 0 | Metallurgy |
A number of examples of molecular mimicry by pathogens, emulating natural endogenous ligands of paired receptors for immune evasion, have been described in the literature. Such interactions are particularly common with the inhibitory members of receptor pairs, bolstering the hypothesis that activating partners are a later evolutionary response to this immune escape strategy.
The first described interaction between a paired receptor and a viral protein identified ILT-2 and ILR-4 (LILRB1 and LILRB2) as targets for herpes simplex virus UL18 protein, which resembles an MHC-I molecule. Variations in susceptibility to mouse cytomegalovirus infection due to differences in Ly49-family paired receptors among mouse strains are well-characterized, and are attributed to the structural resemblance between the viral protein m157 and MHC-I molecules. The pathogenic bacterium Escherichia coli K1 exposes surface polysialic acid molecules that serve as a molecular mimic for the native ligand of the inhibitory receptor Siglec-11, but induces an opposing response through interactions with the paired activating receptor Siglec-16, exemplifying the benefit of activating receptors as defense mechanisms against molecular mimicry by pathogens.
Paired receptors are also used as viral entry receptors by a number of viruses and occasionally as entry mechanisms for other pathogens. Sialylation is common among mammalian cell-surface proteins and a number of pathogens use sialic acid - either self-synthesized or obtained from the host cell - to evade host immunity, including by interacting with inhibitory siglec receptors. | 1 | Gene expression + Signal Transduction |
The growth of Alabamas iron and steel industry was significantly influenced by Tannehill iron-making practices, such as using distilled coal residues as a furnace fuel, making early experimentation with coke, and reducing red iron ore from Red Mountain in a blast furnace. Due to the significant role that Tannehill pays in Alabamas iron and steel industry, the Alabama Central District of Civitan International and the representatives of the University of Alabama first proposed in the late 1960s that a state park should be built to preserve the site of Tannehill Ironworks, the birthplace of the Birmingham Iron industry. The proposal was approved by the state in 1969, and in the following year 1970, the Tannehill Historical State Parkopened to the public. There are more than 45 historical buildings in this state park, including the May Plantation Cotton Gin House, the John Wesley Hall Gristmill, as well as a collection of log cabins that trace back to the nineteenth century. Among the efforts to preserve the historical buildings and Tannehill artifacts, the Iron and Steel Museum of Alabama was built, and it opened in 1981. At present, the Tannehill Ironworks state park has been listed on the National Register of Historic Places and the Civil War Discovery Trail. In particular, the museum demonstrates how 13 iron manufacturers and 6 rolling mills worked to produce iron during the Civil war, making the Tannehill Ironworks among the best-preserved and oldest historical sites in the Southeastern part of this country. From 2004 to 2005, the museum had a significant make-over to introduce more new exhibits to the site, including an old rice-plantation-owned power source, and one of the oldest steam engines in this country. In 2017, Tannehill Ironworks, containing the Iron and Steel Museum of Alabama, became one of the six Birmingham historical sites which contributed to the creation of the Birmingham Industrial Heritage Trail. More recently, the Tannehill Furnace memorial park has become one of the most visited sites in Alabama, and the number of visitors each year exceeds 425,000. This is mainly due to the park's organisation of a variety of outdoor events and activities; for example, the Trade Days event is organised monthly from March to November each year, and visitors also have an opportunity to participant in a Civil War battle re-enactment. | 0 | Metallurgy |
The oxidizing gases flow upward, i.e., counter-current to the descending charge. In a well-insulated roaster, external heating is unnecessary except when the charge is highly moist. The hearth at the top of the roaster dries and heats the charge. Ignition and oxidation of the charge occur lower down. | 0 | Metallurgy |
A finery forge is a forge used to produce wrought iron from pig iron by decarburization in a process called "fining" which involved liquifying cast iron in a fining hearth and removing carbon from the molten cast iron through oxidation. Finery forges were used as early as the 3rd century BC in China. The finery forge process was replaced by the puddling process and the roller mill, both developed by Henry Cort in 1783–4, but not becoming widespread until after 1800. | 0 | Metallurgy |
A fourth group has also been discovered and members have three amino acids between the two cysteines and is termed CXC chemokine (or d-chemokines). The only CXC chemokine discovered to date is called fractalkine (or CXCL1). It is both secreted and tethered to the surface of the cell that expresses it, thereby serving as both a chemoattractant and as an adhesion molecule. | 1 | Gene expression + Signal Transduction |
Marrow is part of I'm a Scientist, Get me out of here! energy generation zone. He has also been a key developer and academic consultant for the Dissemination of IT for the Promotion of Materials Science (DoITPoMS). Global Cycle Network Technology (GCN Tech) interviewed James about carbon fibre fatigue and strain in 2022. | 0 | Metallurgy |
In the early 1990s, technical personnel from the then Union Miniére worked with MIM Holdings personnel to develop an ISASMELT-based process to treat scrap materials and residues containing copper and lead. Union Miniére operated a smelter at Hoboken, near Antwerpen in Belgium, that specialised in recycling scrap non-ferrous materials. The test work program was undertaken using an ISASMELT test rig at MIM Holdings’ lead refinery, Britannia Refined Metals, at Northfleet in the United Kingdom.
A demonstration plant was designed by MIM Holdings personnel and operated for several months at the Hoboken smelter site. The new smelter was commissioned in the final quarter of 1997 and in 2007 was treating up to 300,000 t/y of secondary materials. The installation of the ISASMELT furnace replaced a roasting plant, a sinter plant, 1 of two sulfuric acid plants, a copper blast furnace and four Hoboken converters. It substantially reduced operating costs at the Hoboken smelter.
Umicore's Hoboken plant uses a two-step process in a single furnace. The first step involves the oxidation of the feed to form a copper matte and a lead-rich slag. The slag is then tapped and the remaining copper matte is then converted to blister copper. The lead-rich slag is subsequently reduced in a blast furnace to produce lead metal, while the copper is refined and the contained precious metals recovered. | 0 | Metallurgy |
Members of the chemokine family are divided into four groups depending on the spacing of their first two cysteine residues. Thus the nomenclature for chemokines is, e.g.: CCL1 for the ligand 1 of the CC-family of chemokines, and CCR1 for its respective receptor. | 1 | Gene expression + Signal Transduction |
SAC solders have outperformed high-Pb solders C4 joints in ceramic ball grid array (CBGA) systems, which are ball-grid arrays with a ceramic substrate. The CBGA showed consistently better results in thermal cycling for Pb-free alloys. The findings also show that SAC alloys are proportionately better in thermal fatigue as the thermal cycling range decreases. SAC performs better than Sn-Pb at the less extreme cycling conditions. Another advantage of SAC is that it appears to be more resistant to gold embrittlement than Sn-Pb. In test results, the strength of the joints is substantially higher for the SAC alloys than the Sn-Pb alloy. Also, the failure mode is changed from a partially brittle joint separation to a ductile tearing with the SAC. | 0 | Metallurgy |
Barrier activity has been linked to the disruption of specific processes in the heterochromatin formation pathway. These types of insulators modify the nucleosomal substrate in the reaction cycle that is central to heterochromatin formation. Modifications are achieved through various mechanisms including nucleosome removal, in which nucleosome-excluding elements disrupt heterochromatin from spreading and silencing (chromatin-mediated silencing). Modification can also be done through recruitment of histone acetyltransferase(s) and ATP-dependent nucleosome remodelling complexes. | 1 | Gene expression + Signal Transduction |
Pitting corrosion is defined by localized attack, ranging from microns to millimeters in diameter, in an otherwise passive surface and only occurs for specific alloy and environmental combinations. Thus, this type of corrosion typically occurs in alloys that are protected by a tenacious (passivating) oxide film such as stainless steels, nickel alloys, aluminum alloys in environments that contain an aggressive species such as chlorides (Cl) or thiosulfates (SO). In contrast, alloy/environment combinations where the passive film is not very protective usually will not produce pitting corrosion. A good example of the importance of alloy/environment combinations is carbon steel. In environments where the pH value is lower than 10, carbon steel does not form a passivating oxide film and the addition of chloride results in uniform attack over the entire surface. However, at pH greater than 10 (alkaline) the oxide is protective and the addition of chloride results in pitting corrosion.
Besides chlorides, other anions implicated in pitting include thiosulfates (SO), fluorides and iodides. Stagnant water conditions with low concentrations of dissolved oxygen also favor pitting. Thiosulfates are particularly aggressive species and are formed by partial oxidation of pyrite (pyrite|, a ferrous disulfide), or partial sulfate reduction by microorganisms, a.o. by sulfate reducing bacteria (SRB). Thiosulfates are a concern for corrosion in many industries handling sulfur-derived compounds: sulfide ores processing, oil wells and pipelines transporting soured oils, kraft paper production plants, photographic industry, methionine and lysine factories. | 0 | Metallurgy |
Epigenetic Therapy is the use of drugs or other epigenome-influencing techniques to treat medical conditions.
It is recently regarded as promising therapy to NSCLC.
As can be seen in the above, SFRP1 was downregulated epigenetically in NSCLC and was recently proposed as one of epigenetic therapy target. | 1 | Gene expression + Signal Transduction |
Corrosion in space is the corrosion of materials occurring in outer space. Instead of moisture and oxygen acting as the primary corrosion causes, the materials exposed to outer space are subjected to vacuum, bombardment by ultraviolet and X-rays, and high-energy charged particles (mostly electrons and protons from solar wind). In the upper layers of the atmosphere (between 90–800 km), the atmospheric atoms, ions, and free radicals, most notably atomic oxygen, play a major role. The concentration of atomic oxygen depends on altitude and solar activity, as the bursts of ultraviolet radiation cause photodissociation of molecular oxygen. Between 160 and 560 km, the atmosphere consists of about 90% atomic oxygen. | 0 | Metallurgy |
* ATRX-syndrome (α-thalassemia X-linked mental retardation) and α-thalassemia myelodysplasia syndrome are caused by mutations in ATRX, a SNF2-related ATPase with a PHD finger domain.
* CHARGE syndrome, an autosomal dominant disorder, has been linked recently to haploinsufficiency of CHD7, which encodes the CHD family ATPase CHD7. | 1 | Gene expression + Signal Transduction |
VIM involves placing a core-less induction furnace into a vacuum chamber. The melting and casting operations are carried out at low pressures to control the entire alloy chemistry process. | 0 | Metallurgy |
Signal transducer and activator of transcription 3 (STAT3) is a transcription factor which in humans is encoded by the STAT3 gene. It is a member of the STAT protein family. | 1 | Gene expression + Signal Transduction |
Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ball bearing). Spalling and spallation both describe the process of surface failure in which spall is shed.
The terms spall, spalling, and spallation have been adopted by particle physicists; in neutron scattering instruments, neutrons are generated by bombarding a uranium (or other) target with a stream of atoms. The neutrons that are ejected from the target are known as "spall". | 0 | Metallurgy |
In modern gas turbines, the turbine entry temperature (~1750K) exceeds superalloy incipient melting temperature (~1600K), with the help of surface engineering. | 0 | Metallurgy |
TLRs are a type of pattern recognition receptor (PRR) and recognize molecules that are broadly shared by pathogens but distinguishable from host molecules, collectively referred to as pathogen-associated molecular patterns (PAMPs). In addition to the recognition of exogenous PAMPs, TLRs can also bind to endogenous damage-associated molecular patterns (DAMPs) such as heat shock proteins (HSPs) or plasma membrane constituents. TLRs together with the Interleukin-1 receptors form a receptor superfamily, known as the "interleukin-1 receptor / toll-like receptor superfamily"; all members of this family have in common a so-called TIR (toll-IL-1 receptor) domain.
Three subgroups of TIR domains exist. Proteins with subgroup 1 TIR domains are receptors for interleukins that are produced by macrophages, monocytes, and dendritic cells and all have extracellular Immunoglobulin (Ig) domains. Proteins with subgroup 2 TIR domains are classical TLRs, and bind directly or indirectly to molecules of microbial origin. A third subgroup of proteins containing TIR domains consists of adaptor proteins that are exclusively cytosolic and mediate signaling from proteins of subgroups 1 and 2. | 1 | Gene expression + Signal Transduction |
Ceramide-1-phosphate (C1P) is formed by the action of ceramide kinase (CK) enzymes on Cer. C1P carry ionic charge at neutral pH and contain two hydrophobic chains making it relatively insoluble in aqueous environment. Thus, C1P reside in the organelle where it was formed and is unlikely to spontaneously flip-flop across membrane bilayers.
C1P activate phospholipase A2 and is found, along with CK, to be a mediator of arachidonic acid released in cells in response to a protein called interleukin-1β (IL-1β) and a lipid-soluble molecule that transports calcium ions (Ca) across the bilayer, also known as calcium ionophore. C1P was also previously reported to encourage cell division (mitogenic) in fibroblasts, block apoptosis by inhibiting acid SMase in white blood cells within tissues (macrophages) and increase intracellular free calcium concentrations in thyroid cells. C1P also has known roles in vesicular trafficking, cell survival, phagocytosis ("cell eating") and macrophage degranulation. | 1 | Gene expression + Signal Transduction |
Most transcription factors function in cooperation with other factors by protein–protein interactions. Association of MITF with other proteins is a critical step in the regulation of MITF-mediated transcriptional activity. Some commonly studied MITF interactions include those with MAZR, PIAS3, Tfe3, hUBC9, PKC1, and LEF1. Looking at the variety of structures gives insight into MITF's varied roles in the cell.
The Myc-associated zinc-finger protein related factor (MAZR) interacts with the Zip domain of MITF. When expressed together, both MAZR and MITF increase promoter activity of the mMCP-6 gene. MAZR and MITF together transactivate the mMCP-6 gene. MAZR also plays a role in the phenotypic expression of mast cells in association with MITF.
PIAS3 is a transcriptional inhibiter that acts by inhibiting STAT3's DNA binding activity. PIAS3 directly interacts with MITF, and STAT3 does not interfere with the interaction between PIAS3 and MITF. PIAS3 functions as a key molecule in suppressing the transcriptional activity of MITF. This is important when considering mast cell and melanocyte development.
MITF, TFE3 and TFEB are part of the basic helix-loop-helix-leucine zipper family of transcription factors. Each protein encoded by the family of transcription factors can bind DNA. MITF is necessary for melanocyte and eye development and new research suggests that TFE3 is also required for osteoclast development, a function redundant of MITF. The combined loss of both genes results in severe osteopetrosis, pointing to an interaction between MITF and other members of its transcription factor family. In turn, TFEB has been termed as the master regulator of lysosome biogenesis and autophagy. Interestingly, MITF, TFEB and TFE3 separate roles in modulating starvation-induced autophagy have been described in melanoma. Moreover, MITF and TFEB proteins, directly regulate each other’s mRNA and protein expression while their subcellular localization and transcriptional activity are subject to similar modulation, such as the mTOR signaling pathway.
UBC9 is a ubiquitin conjugating enzyme whose proteins associates with MITF. Although hUBC9 is known to act preferentially with SENTRIN/SUMO1, an in vitro analysis demonstrated greater actual association with MITF. hUBC9 is a critical regulator of melanocyte differentiation. To do this, it targets MITF for proteasome degradation.
Protein kinase C-interacting protein 1 (PKC1) associates with MITF. Their association is reduced upon cell activation. When this happens MITF disengages from PKC1. PKC1 by itself, found in the cytosol and nucleus, has no known physiological function. It does, however, have the ability to suppress MITF transcriptional activity and can function as an in vivo negative regulator of MITF induced transcriptional activity.
The functional cooperation between MITF and the lymphoid enhancing factor (LEF-1) results in a synergistic transactivation of the dopachrome tautomerase gene promoter, which is an early melanoblast marker. LEF-1 is involved in the process of regulation by Wnt signaling. LEF-1 also cooperates with MITF-related proteins like TFE3. MITF is a modulator of LEF-1, and this regulation ensures efficient propagation of Wnt signals in many cells. | 1 | Gene expression + Signal Transduction |
Altered expression profiles in β-catenin have been associated with dilated cardiomyopathy in humans. β-Catenin upregulation of expression has generally been observed in patients with dilated cardiomyopathy. In a particular study, patients with end-stage dilated cardiomyopathy showed almost doubled estrogen receptor alpha (ER-alpha) mRNA and protein levels, and the ER-alpha/beta-catenin interaction, present at intercalated discs of control, non-diseased human hearts was lost, suggesting that the loss of this interaction at the intercalated disc may play a role in the progression of heart failure. Together with BCL9 and PYGO proteins, β-catenin coordinates different aspects of heard development, and mutations in Bcl9 or Pygo in model organisms - such as the mouse and zebrafish - cause phenotypes that are very similar to human congenital heart disorders. | 1 | Gene expression + Signal Transduction |
Carbon Catabolite Repression—Negative On TATA-less, or CCR4-Not, is a multiprotein complex that functions in gene expression. The complex has multiple enzymatic activities as both a poly(A) 3′-5′ exonuclease and a ubiquitin ligase. The exonuclease activity of CCR4-Not shortens the poly(A) tail found at 3' end of almost every eukaryotic mRNA. The complex is present both in the nucleus where it regulates transcription and in the cytoplasm where it associates with translating ribosomes and RNA processing bodies. In mammalian cell, it has a function in the regulation of the cell cycle, chromatin modification, activation and inhibition of transcription initiation, control of transcription elongation, RNA export, nuclear RNA surveillance, and DNA damage repair in nucleus. Ccr4–Not complex plays an important role in mRNA decay and protein quality control in the cytoplasm. | 1 | Gene expression + Signal Transduction |
Drosha shares striking structural similarity with the downstream ribonuclease Dicer, suggesting an evolutionary relationship, though Drosha and related enzymes are found only in animals while Dicer relatives are widely distributed, including among protozoans. Both components of the microprocessor complex are conserved among the vast majority of metazoans with known genomes. Mnemiopsis leidyi, a ctenophore, lacks both Drosha and DGCR8 homologs, as well as recognizable miRNAs, and is the only known metazoan with no detectable genomic evidence of Drosha. In plants, the miRNA biogenesis pathway is somewhat different; neither Drosha nor DGCR8 has a homolog in plant cells, where the first step in miRNA processing is usually executed by a different nuclear ribonuclease, DCL1, a homolog of Dicer.
It has been suggested based on phylogenetic analysis that the key components of RNA interference based on exogenous substrates were present in the ancestral eukaryote, likely as an immune mechanism against viruses and transposable elements. Elaboration of this pathway for miRNA-mediated gene regulation is thought to have evolved later. | 1 | Gene expression + Signal Transduction |
For gene knockout investigations, RNA interference (RNAi), a more recent method, also known as gene silencing, has gained popularity. In RNA interference (RNAi), messenger RNA for a particular gene is inactivated using small interfering RNA (siRNA) or short hairpin RNA (shRNA). This effectively stops the gene from being expressed. Oncogenes like Bcl-2 and p53, as well as genes linked to neurological disease, genetic disorders, and viral infections, have all been targeted for gene silencing utilizing RNA interference (RNAi). | 1 | Gene expression + Signal Transduction |
In environmental chemistry, air sparging is an in situ remediation technique that removes volatile pollutants from contaminated groundwater and soil. | 0 | Metallurgy |
For many non-coding RNAs, including tRNA, rRNA, snRNA, and snoRNA, polyadenylation is a way of marking the RNA for degradation, at least in yeast. This polyadenylation is done in the nucleus by the TRAMP complex, which maintains a tail that is around 4 nucleotides long to the 3′ end. The RNA is then degraded by the exosome. Poly(A) tails have also been found on human rRNA fragments, both the form of homopolymeric (A only) and heterpolymeric (mostly A) tails. | 1 | Gene expression + Signal Transduction |
Subsets and Splits