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In biochemical engineering, sparging can remove low-boiling liquids from a solution. The low-boiling components evaporate more rapidly, so the gas bubbles remove more of them from the bulk solution containing higher-boiling components. It is an alternative to distillation, and it does not require heat. | 0 | Metallurgy |
Most MAPKs have a number of shared characteristics, such as the activation dependent on two phosphorylation events, a three-tiered pathway architecture and similar substrate recognition sites. These are the "classical" MAP kinases. But there are also some ancient outliers from the group as sketched above, that do not have dual phosphorylation sites, only form two-tiered pathways, and lack the features required by other MAPKs for substrate binding. These are usually referred to as "atypical" MAPKs. It is yet unclear if the atypical MAPKs form a single group as opposed to the classical ones.
The mammalian MAPK family of kinases includes three subfamilies:
# Extracellular signal-regulated kinases (ERKs)
# c-Jun N-terminal kinases (JNKs)
# p38 mitogen-activated protein kinases (p38s)
Generally, ERKs are activated by growth factors and mitogens, whereas cellular stresses and inflammatory cytokines activate JNKs and p38s. | 1 | Gene expression + Signal Transduction |
The expression of VMAT1 in healthy endocrine cells was compared to VMAT1 expression in infants with hyperinsulinemic hypoglycemia and adults with pancreatic endocrine tumors. Through immunohistochemistry (IHC) and in situ hybridization (ISH), they found VMAT1 and VMAT2 were located in mutually exclusive cell types, and that in insulinomas VMAT2 activity disappeared, suggesting that if only VMAT1 activity is present in the endocrine system, this type of cancer is likely. | 1 | Gene expression + Signal Transduction |
β-Catenin is a proto-oncogene. Mutations of this gene are commonly found in a variety of cancers: in primary hepatocellular carcinoma, colorectal cancer, ovarian carcinoma, breast cancer, lung cancer and glioblastoma. It has been estimated that approximately 10% of all tissue samples sequenced from all cancers display mutations in the CTNNB1 gene. Most of these mutations cluster on a tiny area of the N-terminal segment of β-catenin: the β-TrCP binding motif. Loss-of-function mutations of this motif essentially make ubiquitinylation and degradation of β-catenin impossible. It will cause β-catenin to translocate to the nucleus without any external stimulus and continuously drive transcription of its target genes. Increased nuclear β-catenin levels have also been noted in basal cell carcinoma (BCC), head and neck squamous cell carcinoma (HNSCC), prostate cancer (CaP), pilomatrixoma (PTR) and medulloblastoma (MDB) These observations may or may not implicate a mutation in the β-catenin gene: other Wnt pathway components can also be faulty.
Similar mutations are also frequently seen in the β-catenin recruiting motifs of APC. Hereditary loss-of-function mutations of APC cause a condition known as familial adenomatous polyposis. Affected individuals develop hundreds of polyps in their large intestine. Most of these polyps are benign in nature, but they have the potential to transform into deadly cancer as time progresses. Somatic mutations of APC in colorectal cancer are also not uncommon. β-Catenin and APC are among the key genes (together with others, like K-Ras and SMAD4) involved in colorectal cancer development. The potential of β-catenin to change the previously epithelial phenotype of affected cells into an invasive, mesenchyme-like type contributes greatly to metastasis formation. | 1 | Gene expression + Signal Transduction |
Observations of an extracellularly secreted glucosyltransferase (gtfG) sequentially proximal to and activated by an rgg gene with inverted repeats in the intergenic region of Streptococcus gordonii served as a basis for studying its homology between Streptococcus pyogenes. It was discovered that S. pyogenes also shared an rgg/ropB gene located directly next to the subject of its transcriptional regulation, in this case speB protease, with intergenic inverted repeats. Confirmation of linkage between rgg/ropB and speB secretion activation was achieved by means of ropB insertional disruption which resulted in decreased speB production. | 1 | Gene expression + Signal Transduction |
The C/EBPα, C/EBPβ, C/EBPγ and C/EBPδ genes are without introns. C/EBPζ has four exons; C/EBPε has two, which lead to four isoforms due to an alternative use of promoters and splicing. For C/EBPα and C/EBPβ, different sizes of polypeptides can be produced by alternative use of initiation codons. This is thought to be due to weak ribosome scanning mechanisms. The mRNA of C/EBPα can transcribe into two polypeptides. For C/EBPβ, three different polypeptides are made: LAP* (38 kDa), LAP (35 kDa) and LIP (20 kDa). The most translated isoform is LAP, then LAP* and LIP. LIP can act as an inhibitor of the other C/EBPs by forming non-functional heterodimers. | 1 | Gene expression + Signal Transduction |
Hormonal imprinting (HI) is a phenomenon which takes place at the first encounter between a hormone and its developing receptor in the critical periods of life (in unicellulars during the whole life) and determines the later signal transduction capacity of the cell. The most important period in mammals is the perinatal one, however this system can be imprinted at weaning, at puberty and in case of continuously dividing cells during the whole life. Faulty imprinting is caused by drugs, environmental pollutants and other hormone-like molecules present in excess at the critical periods with lifelong receptorial, morphological, biochemical and behavioral consequences. HI is transmitted to the hundreds of progeny generations in unicellulars and (as proved) to a few generations also in mammals. | 1 | Gene expression + Signal Transduction |
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. Blast refers to the combustion air being supplied above atmospheric pressure.
In a blast furnace, fuel (coke), ores, and flux (limestone) are continuously supplied through the top of the furnace, while a hot blast of air (sometimes with oxygen enrichment) is blown into the lower section of the furnace through a series of pipes called tuyeres, so that the chemical reactions take place throughout the furnace as the material falls downward. The end products are usually molten metal and slag phases tapped from the bottom, and waste gases (flue gas) exiting from the top of the furnace. The downward flow of the ore along with the flux in contact with an upflow of hot, carbon monoxide-rich combustion gases is a countercurrent exchange and chemical reaction process.
In contrast, air furnaces (such as reverberatory furnaces) are naturally aspirated, usually by the convection of hot gases in a chimney flue. According to this broad definition, bloomeries for iron, blowing houses for tin, and smelt mills for lead would be classified as blast furnaces. However, the term has usually been limited to those used for smelting iron ore to produce pig iron, an intermediate material used in the production of commercial iron and steel, and the shaft furnaces used in combination with sinter plants in base metals smelting.
Blast furnaces are estimated to have been responsible for over 4% of global greenhouse gas emissions between 1900 and 2015, but are difficult to decarbonize. | 0 | Metallurgy |
The rank product is a biologically motivated rank test for the detection of differentially expressed genes in replicated microarray experiments.
It is a simple non-parametric statistical method based on ranks of fold changes. In addition to its use in expression profiling, it can be used to combine ranked lists in various application domains, including proteomics, metabolomics, statistical meta-analysis, and general feature selection. | 1 | Gene expression + Signal Transduction |
An example of an autocrine agent is the cytokine interleukin-1 in monocytes. When interleukin-1 is produced in response to external stimuli, it can bind to cell-surface receptors on the same cell that produced it.
Another example occurs in activated T cell lymphocytes, i.e., when a T cell is induced to mature by binding to a peptide:MHC complex on a professional antigen-presenting cell and by the B7:CD28 costimulatory signal. Upon activation, "low-affinity" IL-2 receptors are replaced by "high-affinity" IL-2 receptors consisting of α, β, and γ chains. The cell then releases IL-2, which binds to its own new IL-2 receptors, causing self-stimulation and ultimately a monoclonal population of T cells. These T cells can then go on to perform effector functions such as macrophage activation, B cell activation, and cell-mediated cytoxicity. | 1 | Gene expression + Signal Transduction |
Paired receptors are membrane proteins with extracellular domains that interact with extracellular ligands. The extracellular region may contain multiple repeating protein domains and may be members of either the immunoglobulin or C-type lectin families. The extracellular domains of homologous paired receptors are typically very similar in sequence but have different binding affinity for their shared ligands, with the inhibitory member of the pair binding more tightly.
Homologous paired receptors have characteristic differences in their transmembrane and cytoplasmic regions that distinguish the activating and inhibiting members of the pair. Inhibitory receptors have a cytoplasmic sequence typically containing at least one immunoreceptor tyrosine-based inhibitory motif (ITIM). Activating receptors have a truncated cytoplasmic sequence compared to their corresponding inhibitory receptor and feature a positively charged amino acid residue in their transmembrane domain, enabling protein-protein interaction with an adaptor protein that possesses a immunoreceptor tyrosine-based activation motif (ITAM). | 1 | Gene expression + Signal Transduction |
Many co-receptor-related disorders occur due to mutations in the receptor's coding gene. LRP5 (low-density lipoprotein receptor-related protein 5) acts as a co-receptor for the Wnt-family of glycoproteins which regulate bone mass. Malfunctions in this co-receptor lead to lower bone density and strength which contribute to osteoporosis.
Loss of function mutations in LRP5 have been implicated in Osteoporosis-pseudoglioma syndrome, Familial exudative vitreoretinopathy, and a specific missense mutation in the first β-propeller region of LRP5 can lead to abnormally high bone density or osteopetrosis. Mutations in LRP1 have also been found in cases of Familial Alzheimer's disease
Loss of function mutations in the Cryptic co-receptor can lead to random organ positioning due to developmental left-right orientation defects.
Gigantism is believed to be caused, in some cases, by a loss of function of the Glypican 3 co-receptor. | 1 | Gene expression + Signal Transduction |
ASTM G85 is the most popular global test standard covering modified salt spray tests. There are five such tests altogether, referred to in ASTM G85 as annexes A1 through to A5. Many of these modified tests originally arose within particular industry sector, in order to address the need for a corrosion test capable of replicating the effects of naturally occurring corrosion and accelerate these effects.
This acceleration arises through the use of chemically altered salt spray solutions, often combined with other test climates and in most cases, the relatively rapid cycling of these test climates over time. Although popular in certain industries, modified salt spray testing has in many cases been superseded by cyclic corrosion testing (CCT)
The type of environmental test chambers used for modified salt spray testing to ASTM G85 are generally similar to the chambers used for testing to ASTM B117, but will often have some additional features, such as an automatic climate cycling control system.
ASTM G85 Annex A1 – Acetic Acid Salt Spray Test (non-cyclic)
This test can be used to determine the relative resistance to corrosion of decorative chromium plating on steel and zinc based die casting when exposed to an acetic acid salt spray climate at an elevated temperature. This test is also referred to as an ASS test.
Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of salt water solution, prepared in accordance with the requirements of the test standard and acidified (pH 3.1–3.3) by the addition of acetic acid. This spray is set to fall-out on to the specimens at a rate of 1–2 ml/80 cm/hour, in a chamber temperature of 35 °C. This climate is maintained under constant steady state conditions. The test duration is variable.
ASTM G85 Annex A2 – Acidified Salt Fog Test (cyclic).
This test can be used to test the relative resistance to corrosion of aluminium alloys when exposed to a changing climate of acetic acid salt spray, followed by air drying, followed by high humidity, all at an elevated temperature. This test is also referred to as a MASTMAASIS test.
Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises the following 3 part repeating cycle. 0.75 hours exposure to a continuous indirect spray of salt water solution, prepared in accordance with the requirements of the test standard and acidified (pH 2.8–3.0) by the addition of acetic acid. This spray is set to fall-out on to the specimens at a rate of 1–2 ml/80 cm/hour. This is followed by a 2 hour exposure to an air drying (purge) climate. This is followed by 3.25 hours exposure to a high humidity climate which gradually rises to between 65% RH and 95% RH. The entire test cycle is at a constant chamber temperature of 49 °C. The number of cycle repeats and therefore the test duration is variable.
ASTM G85 Annex A3 – Seawater Acidified Test (cyclic)
This test can be used to test the relative resistance to corrosion of coated or uncoated aluminium alloys and other metals, when exposed to a changing climate of acidified synthetic seawater spray, followed by a high humidity, both at an elevated temperature. This test is also referred to as a SWAAT test.
Test specimens are placed in an enclosed chamber, and exposed to a changing climate that comprises the following 2 part repeating cycle. First, a 30 minute exposure to a continuous indirect spray of synthetic seawater solution, prepared in accordance with the requirements of the test standard and acidified (pH 2.8–3.0) by the addition of acetic acid. This spray is set to fall-out on to the specimens at a rate of 1–2 ml/80 cm/hour. This is followed by a 90 minute exposure to a high humidity climate (above 98% RH). The entire test cycle is at a constant chamber temperature of 49 °C (may be reduced to 24–35 °C for organically coated specimens). The number of cycle repeats and therefore the test duration is variable.
ASTM G85 Annex A4 – Salt Spray Test (cyclic)
This test can be used to test the relative resistance to corrosion of product samples that are likely to encounter a combined /salt spray/acid rain environment during their usual service life.
Test specimens are placed in an enclosed chamber, and exposed to 1 of 2 possible changing climate cycles. In either case, the exposure to salt spray may be salt water spray or synthetic sea water prepared in accordance with the requirements of the test standard. The most appropriate test cycle and spray solutions are to be agreed between parties.
The first climate cycle comprises a continuous indirect spray of neutral (pH 6.5–7.2) salt water/synthetic seawater solution, which falls-out on to the specimens at a rate of 1–2 ml/80 cm/hour. During this spraying, the chamber is dosed with gas at a rate of 35 cm/minute/m of chamber volume, for 1 hour in every 6 hours of spraying. The entire test cycle is at a constant chamber temperature of 35 °C. The number of cycle repeats and therefore the test duration is variable.
The second climate cycle comprises 0.5 hours of continuous indirect spray of neutral (pH 6.5–7.2) salt water/synthetic seawater solution, which falls-out on to the specimens at a rate of 1–2 ml/80 cm/hour. This is followed by 0.5 hours of dosing with gas at a rate of 35 cm/minute/m of chamber volume. This is followed by 2 hours of high humidity soak. The entire test cycle is at a constant chamber temperature of 35 °C. The number of cycle repeats and therefore the test duration is variable.
ASTM G85 Annex A5 – Dilute Electrolyte Salt Fog/Dry Test (cyclic)
This test can be used to test the relative resistance to corrosion of paints on steel when exposed to a changing climate of dilute salt spray at ambient temperature, followed by air drying at elevated temperature.
It is a popular test in the surface coatings industry, where it is also referred to as the PROHESION test.
Test specimens are placed in an enclosed chamber, and exposed to a changing climate with the following 2-part cycle.
First, a 1-hour exposure to a continuous indirect spray of salt water solution, prepared in accordance with the requirements of the test standard and acidified (pH 3.1–3.3) by the addition of acetic acid.
This spray is set to fall on the specimens at a rate of 1–2 ml/80 cm/hour, in an ambient chamber temperature (21–27 °C). This is followed by a 1-hour exposure to an air drying (purge) climate at 35 °C.
The cycle repeats until the desired duration has been achieved. | 0 | Metallurgy |
pRb is a multifunctional protein with many binding and phosphorylation sites. Although its common function is seen as binding and repressing E2F targets, pRb is likely a multifunctional protein as it binds to at least 100 other proteins.
pRb has three major structural components: a carboxy-terminus, a "pocket" subunit, and an amino-terminus. Within each domain, there are a variety of protein binding sites, as well as a total of 15 possible phosphorylation sites. Generally, phosphorylation causes interdomain locking, which changes pRb's conformation and prevents binding to target proteins. Different sites may be phosphorylated at different times, giving rise to many possible conformations and likely many functions/activity levels. | 1 | Gene expression + Signal Transduction |
One of the most well discussed, and detrimental, embrittlement is hydrogen embrittlement in metals. There are multiple ways that hydrogen atoms can diffuse into metals, including from environment or during processing (eg. electroplating). The exact mechanism that causes hydrogen embrittlement is still not determined, but many theories are proposed and are still undergoing verification. Hydrogen atoms are likely to diffuse to grain boundaries of metals, which becomes a barrier for dislocation motion and builds up stress near the atoms. When the metal is stressed, the stress is concentrated near the grain boundaries due to hydrogen atoms, allowing a crack to nucleate and propagate along the grain boundaries to relieve the built-up stress.
There are many ways to prevent or reduce the impact of hydrogen embrittlement in metals. One of the more conventional ways is to place coatings around the metal, which will act as diffusion barriers that prevents hydrogen from being introduced from the environment into the material. Another way is to add traps or absorbers in the alloy which takes into the hydrogen atom and forms another compound. | 0 | Metallurgy |
From about the 14th century, water-power began to be applied to bloomeries, but fewer than ten such sites are suspected. | 0 | Metallurgy |
Calcineurin inhibitors are prescribed for adult rheumatoid arthritis (RA) as a single drug or in combination with methotrexate. The microemulsion formulation is approved by the U.S. Food and Drug Administration for treatment of severely active RA. It is also prescribed for: psoriatic arthritis, psoriasis, acute ocular Behçets disease, juvenile idiopathic arthritis, adult and juvenile polymyositis and dermatomyositis, adult and juvenile systemic lupus erythematosus, adult lupus membranous nephritis, systemic sclerosis, aplastic anemia, steroid-resistant nephrotic syndrome, atopic dermatitis, severe corticosteroid-dependent asthma, severe ulcerative colitis, pemphigus vulgaris, myasthenia gravis, and dry eye disease, with or without Sjögrens syndrome (administered as ophthalmic emulsion). | 1 | Gene expression + Signal Transduction |
The first observations of an autoinducer-controlled phenotype in bacteria were reported in 1970, by Kenneth Nealson, Terry Platt, and J. Woodland Hastings, who observed what they described as a conditioning of the medium in which they had grown the bioluminescent marine bacterium Aliivibrio fischeri. These bacteria did not synthesize luciferase—and therefore did not luminesce—in freshly inoculated culture but only after the bacterial population had increased significantly. Because they attributed this conditioning of the medium to the growing population of cells itself, they referred to the phenomenon as autoinduction. In 1994, after study of the autoinduction phenomenon had expanded into several additional bacteria, the term "quorum sensing" was coined in a review by W. Claiborne Fuqua, Stephen C. Winans, and E. Peter Greenberg.
Dr. Stephen Winnans did not believe the word "autoinducer" fully enveloped the true process, so introduced the world to the term "Quorum Sensing" in 1994 through his article review of autoinduction in bacteria. This new phrase helped relieve confusion between 'autoinduction" and "autoregulation". The phrase "Quorum Sensing" was not stumbled onto, but rather created through trial and error. Dr. Winnans created many options, such as "gridlockins", "communiolins", and "quoromones". Eventually, it was "Quorum Sensing that stuck, and Dr. Stephen Winnans phrase spread quickly into the world. Quorum Sensing is now involved in practically every article written about autoinduction throughout the scientific community. | 1 | Gene expression + Signal Transduction |
In vertebrates, the majority of gene promoters contain a CpG island with numerous CpG sites. When many of a gene's promoter CpG sites are methylated the gene becomes silenced. Colorectal cancers typically have 3 to 6 driver mutations and 33 to 66 hitchhiker or passenger mutations. However, transcriptional silencing may be of more importance than mutation in causing progression to cancer. For example, in colorectal cancers about 600 to 800 genes are transcriptionally silenced by CpG island methylation (see regulation of transcription in cancer). Transcriptional repression in cancer can also occur by other epigenetic mechanisms, such as altered expression of microRNAs. In breast cancer, transcriptional repression of BRCA1 may occur more frequently by over-expressed microRNA-182 than by hypermethylation of the BRCA1 promoter (see Low expression of BRCA1 in breast and ovarian cancers). | 1 | Gene expression + Signal Transduction |
There is much debate to whether transcription factories assemble because of the transcriptional demands of the genome or if they are stable structures that are conserved over time. Experimentally, it appears that they remain fixed over a short period of time; newly made mRNA were pulse labelled over 15 minutes and it showed no new transcription factories appearing. This is also supported by inhibition experiments. In these studies heat shock was used to turn off transcription which resulted in no change in the number of polymerases detected. Upon further analysis of western blot data it was suggested that there was in fact a slight decrease over time of transcription factories. Therefore, it could be claimed that polymerase molecules are released gently over time from the factory when there is a lack of transcription which would eventually lead to the complete loss of the transcription factory.
There is also several pieces of evidence that promotes the idea of transcription factories assembling de novo due to transcriptional demands. GFP polymerase fluorescence experiments have shown that the inducement of transcription in Drosophila polytene nuclei leads to the formation of a factory which contradicts the notion of a stable and secure structure. | 1 | Gene expression + Signal Transduction |
Panel edge staining is the by-product of the build-up of dirt and pollution. It is especially more noticeable on buildings using metallic façades in Asia, and regions close to the equator (such as Florida or South East Asia), as higher rates of air pollution, high levels of humidity and consistent rainfall encourage panel edge staining to develop.
The unique top-to-bottom stain pattern of panel edge staining is caused when the build-up of dirt and pollution is washed from the higher panels to the lower panels of a surface by natural precipitation. | 0 | Metallurgy |
Leaching is done in long pressure vessels which are cylindrical (horizontal or vertical) or of horizontal tube form known as autoclaves. A good example of the autoclave leach process can also be found in the metallurgy of zinc. It is best described by the following chemical reaction:
This reaction proceeds at temperatures above the boiling point of water, thus creating a vapour pressure inside the vessel. Oxygen is injected under pressure, making the total pressure in the autoclave more than 0.6 MPa and temperature at 473-523 K .
The leaching of precious metals such as gold can be carried out with cyanide or ozone under mild conditions. | 0 | Metallurgy |
Crosstalk can even be observed across membranes. Membrane interactions with the extracellular matrix (ECM) and with neighboring cells can trigger a variety of responses within the cell. However, the topography and mechanical properties of the ECM also come to play an important role in powerful, complex crosstalk with the cells growing on or inside the matrix. For example, integrin-mediated cytoskeleton assembly and even cell motility are affected by the physical state of the ECM. Binding of the α5β1 integrin to its ligand (fibronectin) activates the formation of fibrillar adhesions and actin filaments. Yet, if the ECM is immobilized, matrix reorganization of this kind and formation of fibrillar adhesions is inhibited. In turn, binding of the same integrin (α5β1) to an immobilized fibronectin ligand is seen to form highly phosphorylated focal contacts/focal adhesion (cells involved in matrix adhesion) within the membrane and reduces cell migration rates In another example of crosstalk, this change in the composition of focal contacts in the cytoskeleton can be inhibited by members of yet another pathway: inhibitors of myosin light-chain kinases or Rho kinases, H-7 or ML-7, which reduce cell contractility and consequently motility. (see figure 2). | 1 | Gene expression + Signal Transduction |
Oregrounds iron was a grade of iron that was regarded as the best grade available in 18th century England. The term was derived from the small Swedish city of Öregrund, the port from which the bar iron was shipped. It was produced using the Walloon process.
Oregrounds iron is the equivalent of the Swedish vallonjärn, which literally translates as Walloon iron. The Swedish name derives from the iron being produced by the Walloon version of the finery forge process, the Walloon process as opposed to the German method, which was more common in Sweden. Actually, the term is more specialised, as all the Swedish Walloon forges made iron from ore ultimately derived from the Dannemora mine. It was made in about 20 forges mainly in Uppland.
Many of the ironworks were founded by Louis de Geer and other Dutch entrepreneurs who set up ironworks in Sweden in the 1610s and 1620s, with blast furnaces and finery forges. Most of the early forgemen were also from Wallonia. | 0 | Metallurgy |
The SECIS element is found in a wide variety of organisms from all three domains of life (including their viruses). | 1 | Gene expression + Signal Transduction |
The central solenoid and toroidal field superconducting magnets for the planned experimental ITER fusion reactor use niobium–tin as a superconductor. The central solenoid coil will produce a field of . The toroidal field coils will operate at a maximum field of 11.8 T. Estimated use is of NbSn strands and 250 metric tonnes of NbTi strands.
At the Large Hadron Collider at CERN, extra-strong quadrupole magnets (for focussing beams) made with niobium–tin are being installed in key points of the accelerator between late 2018 and early 2020. Niobium tin had been proposed in 1986 as an alternative to niobium–titanium, since it allowed coolants less complex than superfluid helium, but this was not pursued in order to avoid delays while competing with the then-planned US-led Superconducting Super Collider. | 0 | Metallurgy |
Norşuntepe was occupied from the Chalcolithic to the Iron Age. The excavators have recognized 40 different occupation levels ranging in date from the fifth millennium BC to ca. 600 BC. Its occupation levels overlap to a large degree with those excavated at nearby Arslantepe. | 0 | Metallurgy |
This chemogenetic technique can be used for remote manipulation of cells, in particular excitable cells like neurons, both in vitro and in vivo with the administration of specific ligands. Similar techniques in this field include thermogenetics and optogenetics, the control of neurons with temperature or light, respectively.
Viral expression of DREADD proteins, both in-vivo enhancers and inhibitors of neuronal function, have been used to bidirectionally control behaviors in mice (e.g odor discrimination). Due to their ability to modulate neuronal activity, DREADDs are used as a tool to evaluate both the neuronal pathways and behaviors associated with drug-cues and drug addiction. | 1 | Gene expression + Signal Transduction |
Different processes and techniques have been developed around melt spinning which offer advantages to the industrial applications and product consistency. | 0 | Metallurgy |
Type E (chromel–constantan) has a high output (68 μV/°C), which makes it well suited to cryogenic use. Additionally, it is non-magnetic.
Wide range is −270 °C to +740 °C
and narrow range is −110 °C to +140 °C. | 0 | Metallurgy |
RNA interference has been used to silence genes associated with several cancers. In in vitro studies of chronic myelogenous leukemia (CML), siRNA was used to cleave the fusion protein, BCR-ABL, which prevents the drug Gleevec (imatinib) from binding to the cancer cells. Cleaving the fusion protein reduced the amount of transformed hematopoietic cells that spread throughout the body by increasing the sensitivity of the cells to the drug. RNA interference can also be used to target specific mutants. For instance, siRNAs were able to bind specifically to tumor suppressor p53 molecules containing a single point mutation and destroy it, while leaving the wild-type suppressor intact.
Receptors involved in mitogenic pathways that lead to the increased production of cancer cells there have also been targeted by siRNA molecules. The chemokine receptor chemokine receptor 4 (CXCR4), associated with the proliferation of breast cancer, was cleaved by siRNA molecules that reduced the number of divisions commonly observed by the cancer cells. Researchers have also used siRNAs to selectively regulate the expression of cancer-related genes. Antiapoptotic proteins, such as clusterin and survivin, are often expressed in cancer cells. Clusterin and survivin-targeting siRNAs were used to reduce the number of antiapoptotic proteins and, thus, increase the sensitivity of the cancer cells to chemotherapy treatments. In vivo studies are also being increasingly utilized to study the potential use of siRNA molecules in cancer therapeutics. For instance, mice implanted with colon adenocarcinoma cells were found to survive longer when the cells were pretreated with siRNAs that targeted B-catenin in the cancer cells. | 1 | Gene expression + Signal Transduction |
Despite current understanding of 3′-UTRs, they are still relative mysteries. Since mRNAs usually contain several overlapping control elements, it is often difficult to specify the identity and function of each 3′-UTR element, let alone the regulatory factors that may bind at these sites. Additionally, each 3′-UTR contains many alternative AU-rich elements and polyadenylation signals. These cis- and trans-acting elements, along with miRNAs, offer a virtually limitless range of control possibilities within a single mRNA. Future research through the increased use of deep-sequencing based ribosome profiling will reveal more regulatory subtleties as well as new control elements and AUBPs. | 1 | Gene expression + Signal Transduction |
For an extreme example, in a tensile test a bar of steel is strained to just before the length at which it usually fractures. The load is released smoothly and the material relieves some of its strain by decreasing in length. The decrease in length is called the elastic recovery, and the result is a work-hardened steel bar. The fraction of length recovered (length recovered/original length) is equal to the yield-stress divided by the modulus of elasticity. (Here we discuss true stress in order to account for the drastic decrease in diameter in this tensile test.) The length recovered after removing a load from a material just before it breaks is equal to the length recovered after removing a load just before it enters plastic deformation.
The work-hardened steel bar has a large enough number of dislocations that the strain field interaction prevents all plastic deformation. Subsequent deformation requires a stress that varies linearly with the strain observed, the slope of the graph of stress vs. strain is the modulus of elasticity, as usual.
The work-hardened steel bar fractures when the applied stress exceeds the usual fracture stress and the strain exceeds usual fracture strain. This may be considered to be the elastic limit and the yield stress is now equal to the fracture toughness, which is much higher than a non-work-hardened steel yield stress.
The amount of plastic deformation possible is zero, which is less than the amount of plastic deformation possible for a non-work-hardened material. Thus, the ductility of the cold-worked bar is reduced.
Substantial and prolonged cavitation can also produce strain hardening. | 0 | Metallurgy |
Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).
Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), Valine (Val, V). | 1 | Gene expression + Signal Transduction |
In biology, scaffold proteins are crucial regulators of many key signalling pathways. Although scaffolds are not strictly defined in function, they are known to interact and/or bind with multiple members of a signalling pathway, tethering them into complexes. In such pathways, they regulate signal transduction and help localize pathway components (organized in complexes) to specific areas of the cell such as the plasma membrane, the cytoplasm, the nucleus, the Golgi, endosomes, and the mitochondria. | 1 | Gene expression + Signal Transduction |
Casting in bronze reached high perfection in England, where a number of monuments yet remain. William Torel, goldsmith and citizen of London, made a bronze effigy of Henry III, and later that of Queen Eleanor for their tombs in Westminster Abbey; the effigy of Edward III was probably the work of one of his pupils. No bronze fonts are found in English churches, but a number of processional crucifixes have survived from the 15th century, all following the same design and of crude execution. Sanctuary rings or knockers exist at Norwich, Gloucester and elsewhere; the most remarkable is that on the north door of the nave of Durham Cathedral which has sufficient character of its own to differentiate it from its Continental brothers and to suggest a Northern origin.
The Gloucester Candlestick in the Victoria and Albert Museum in South Kensington, displays the power and imagination of the designer as well as an extraordinary manipulative skill on the part of the founder. According to an inscription on the object, this candlestick, which stands some high and is made of an alloy allied to bronze, was made for Abbot Peter who ruled from 1109 to 1112. While the outline is carefully preserved, the ornament consists of a mass of figures of monsters, birds and men, mixed and intertwined to the verge of confusion. As a piece of casting it is a triumph of technical ability. For secular use the mortar was one of the commonest of objects in England as on the Continent; early examples of Gothic design are of great beauty. In later examples a mixture of styles is found in the bands of Gothic and Renaissance ornament, which are freely used in combination. Bronze ewers must have been common; of the more ornate kind two may be seen, one at South Kensington and a second at the British Museum. These are large vessels of about in height, with shields of arms and inscriptions in bell-founders' lettering. Many objects for domestic use, such as mortars, skillets, etc., were produced in later centuries. | 0 | Metallurgy |
* Cathodic arc deposition
* Electron beam physical vapor deposition (EBPVD)
* Ion plating
* Ion beam assisted deposition (IBAD)
* Magnetron sputtering
* Pulsed laser deposition
* Sputter deposition
* Vacuum deposition
* Vacuum evaporation, evaporation (deposition)
* Pulsed electron deposition (PED) | 0 | Metallurgy |
In 1941, Beadle and Tatum proposed on the basis of their study of mutants of the fungus Neurospora sitophila that genes control specific biochemical reactions. They suggested that the functioning of an organism depends on an integrated system of chemical reactions controlled in some manner by genes. They further noted that “It is entirely tenable to suppose that these genes, which are themselves a part of the system, control or regulate specific reactions in the system either by acting directly as enzymes or by determining the specificity of enzymes.” This line of reasoning gave rise to the “one gene–one enzyme hypothesis”. In a retrospective article, Beadle discussed the status of the one gene-one enzyme hypothesis 10 years after it was proposed. Beadle commented on the Cold Spring Harbor Symposium meeting of biologists in 1951. He noted “I have the impression that the number whose faith in one gene-one enzyme remained steadfast could be counted on the fingers of one hand—with a couple of fingers left over.” However by the early 1960s the concept that the DNA base sequence of a gene specifies the amino acid sequence of a protein became well established on the basis of numerous experiments. For example, an experiment by Crick, Brenner, Barnett and Watts-Tobin in 1961 demonstrated that each amino acid in a protein is encoded by a corresponding sequence of three bases in DNA (called a codon). Soon after this, the specific codon assignments for each amino acid were determined (see Genetic code). | 1 | Gene expression + Signal Transduction |
The lactate shuttle hypothesis describes the movement of lactate intracellularly (within a cell) and intercellularly (between cells). The hypothesis is based on the observation that lactate is formed and utilized continuously in diverse cells under both anaerobic and aerobic conditions. Further, lactate produced at sites with high rates of glycolysis and glycogenolysis can be shuttled to adjacent or remote sites including heart or skeletal muscles where the lactate can be used as a gluconeogenic precursor or substrate for oxidation. The hypothesis was proposed by professor George Brooks of the University of California at Berkeley.
In addition to its role as a fuel source predominantly in the muscles, heart, brain, and liver, the lactate shuttle hypothesis also relates the role of lactate in redox signalling, gene expression, and lipolytic control. These additional roles of lactate have given rise to the term ‘lactormone’, pertaining to the role of lactate as a signalling hormone. | 1 | Gene expression + Signal Transduction |
Aside from decorative dentistry which they wore in life and carried the grave with them, ranking datus were often buried with items of gold, either in the form of gold burial goods, or as specifically designed funerary art such as death masks.
Burial goods found in graves from early Philippine history includes various beads earrings rings pendants, combs, strips, and other ornaments.
Another gold feature commonly discovered in elite burials from early historic Philippines are death mask artifacts, meant to cover either part or all of the deceased's face in the grave
When this practice was discovered by the Spanish colonizers, they created a rule that a government representative should always be present whenever the Spanish settlers dug up a grave - so that the Spanish government could get its designated 1/5 of the dug up goods.
Burial goods are among the most common surviving gold artifacts in the Philippines because gold which was not buried was typically eventually reforged into other forms as the colonial period proceeded. | 0 | Metallurgy |
According to EN 13523-0, a prepainted metal (or coil coated metal) is a ‘metal on which a coating material (e.g. paint, film…) has been applied by coil coating’. When applied onto the metallic substrate, the coating material (in liquid, in paste or powder form) forms a film possessing protective, decorative and/or other specific properties.
In 40 years, the European prepainted metal production has multiplied by 18. | 0 | Metallurgy |
Because of the specificity of toll-like receptors (and other innate immune receptors) they cannot easily be changed in the course of evolution, these receptors recognize molecules that are constantly associated with threats (i.e., pathogen or cell stress) and are highly specific to these threats (i.e., cannot be mistaken for self molecules that are normally expressed under physiological conditions). Pathogen-associated molecules that meet this requirement are thought to be critical to the pathogens function and difficult to change through mutation; they are said to be evolutionarily conserved. Somewhat conserved features in pathogens include bacterial cell-surface lipopolysaccharides (LPS), lipoproteins, lipopeptides, and lipoarabinomannan; proteins such as flagellin from bacterial flagella; double-stranded RNA of viruses; or the unmethylated CpG islands of bacterial and viral DNA; and also of the CpG islands found in the promoters of eukaryotic DNA; as well as certain other RNA and DNA molecules. As TLR ligands are present in most pathogens, they may also be present in pathogen-derived vaccines (e.g. MMR, influenza, polio vaccines) most commercially available vaccines have been assessed for their inherent TLR ligands capacity to activate distinct subsets of immune cells. For most of the TLRs, ligand recognition specificity has now been established by gene targeting (also known as "gene knockout"): a technique by which individual genes may be selectively deleted in mice. See the table above for a summary of known TLR ligands. | 1 | Gene expression + Signal Transduction |
* Calmodulin 1 ()
* Calmodulin 2 ()
* Calmodulin 3 ()
* calmodulin 1 pseudogene 1 ()
* Calmodulin-like 3 ()
* Calmodulin-like 4 ()
* Calmodulin-like 5 ()
* Calmodulin-like 6 () | 1 | Gene expression + Signal Transduction |
In 1856, Robert Forester Mushet "used manganese to improve the ability of steel produced by the Bessemer process to withstand rolling and forging at elevated temperatures."
In 1860, Henry Bessemer invented the use of ferromanganese as a method of introducing manganese in controlled proportions during the production of steel. The advantage of combining powdered iron oxide and manganese oxide together is the lower melting point of the combined alloy compared to pure manganese oxide.
In 1872, Lambert von Pantz produced ferromanganese in a blast furnace, with significantly higher manganese content than was previously possible (37% instead of the previous 12%). This won his company international recognition, including a gold medal at the 1873 World Exposition in Vienna and a certificate of award at the 1876 Centennial Exposition in Pennsylvania.
In an 1876 article, MF Gautier explained that the magnetic oxide needs to be slagged off by the addition of manganese (then in the form of spiegel iron) in order to befit it for rolling. | 0 | Metallurgy |
Signaling action in neurons by sigma-2 receptors and their associated ligands results in modulation of action potential firing by regulation of calcium and potassium channels. They also are involved in synaptic vesicular release and modulation of dopamine, serotonin, and glutamate, with activation and increase of the dopaminergic, serotonergic, and noradrenergic activity of neurons. | 1 | Gene expression + Signal Transduction |
Pol I is a 590 kDa enzyme that consists of 14 protein subunits (polypeptides), and its crystal structure in the yeast Saccharomyces cerevisiae was solved at 2.8Å resolution in 2013. Twelve of its subunits have identical or related counterparts in RNA polymerase II (Pol II) and RNA polymerase III (Pol III). The other two subunits are related to Pol II initiation factors and have structural homologues in Pol III.
Ribosomal DNA transcription is confined to the nucleolus, where about 400 copies of the 42.9-kb rDNA gene are present, arranged as tandem repeats in nucleolus organizer regions. Each copy contains a ~13.3 kb sequence encoding the 18S, the 5.8S, and the 28S RNA molecules, interlaced with two internal transcribed spacers, ITS1 and ITS2, and flanked upstream by a 5 external transcribed spacer and a downstream 3 external transcribed spacer. These components are transcribed together to form the 45S pre-rRNA. The 45S pre-rRNA is then post-transcriptionally cleaved by C/D box and H/ACA box snoRNAs, removing the two spacers and resulting in the three rRNAs by a complex series of steps. The 5S ribosomal RNA is transcribed by Pol III. Because of the simplicity of Pol I transcription, it is the fastest-acting polymerase and contributes up to 60% of cellular transcription levels in exponentially growing cells.
In Saccharomyces cerevisiae, the 5S rDNA has the unusual feature of lying inside the rDNA repeat. It is flanked by non-transcribed spacers NTS1 and NTS2, and is transcribed backwards by Pol III, separately from the rest of the rDNA. | 1 | Gene expression + Signal Transduction |
While this emerging field of drug delivery shows excellent promise in targeting specific cells and locations within the body, understanding current challenges and drawbacks can allow researchers to optimize design, development, and delivery to improve the overall outcome of their medical treatment. | 1 | Gene expression + Signal Transduction |
The hardenability of a ferrous alloy is measured by a Jominy test: a round metal bar of standard size (indicated in the top image) is transformed to 100% austenite through heat treatment, and is then quenched on one end with room-temperature water. The cooling rate will be highest at the end being quenched, and will decrease as distance from the end increases. Subsequent to cooling a flat surface is ground on the test piece and the hardenability is then found by measuring the hardness along the bar. The farther away from the quenched end that the hardness extends, the higher the hardenability. This information is plotted on a hardenability graph.
The Jominy end-quench test was invented by Walter E. Jominy (1893-1976) and A.L. Boegehold, metallurgists in the Research Laboratories Division of General Motors Corp., in 1937. For his pioneering work in heat treating, Jominy was recognized by the American Society for Metals (ASM) with its Albert Sauveur Achievement Award in 1944. Jominy served as president of ASM in 1951. | 0 | Metallurgy |
Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).
Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), Valine (Val, V) | 1 | Gene expression + Signal Transduction |
FAIRE-extracted DNA fragments can be analyzed in a high-throughput way using next-generation sequencing techniques. In general, libraries are made by ligating specific adapters to the DNA fragments that allow them to cluster on a platform and be amplified resulting in the DNA sequences being read/determined, and this in parallel for millions of the DNA fragments.
Depending on the size of the genome FAIRE-seq is performed on, a minimum of reads is required to create an appropriate coverage of the data, ensuring a proper signal can be determined. In addition, a reference or input genome, which has not been cross-linked, is often sequenced alongside to determine the level of background noise.
Note that the extracted FAIRE-fragments can be quantified in an alternative method by using quantitative PCR. However, this method does not allow a genome wide / high-throughput quantification of the extracted fragments. | 1 | Gene expression + Signal Transduction |
The Pederson process is a process of refining aluminum that first separates iron by reducing it to metal, and reacting alumina with lime to produce calcium aluminate, which is then leached with sodium hydroxide. It is more environmentally friendly than the more well-known Bayer process. This is because instead of producing alumina slag, also known as red mud, it produces pig iron as a byproduct. Red mud is considered both an economic and environmental challenge in the aluminum industry because it is considered a waste, with little benefit. It destroys the environment with its high pH, and is costly to maintain, even when in a landfill. Iron, however, is used in the manufacture of steel, and has structural uses in civil engineering and chemical uses as a catalyst. | 0 | Metallurgy |
Many of the noble metals can act as catalysts. For example, platinum is used in catalytic converters, devices which convert toxic gases produced in car engines, such as the oxides of nitrogen, into non-polluting substances.
Gold has many industrial applications; it is used as a catalyst in hydrogenation and the water gas shift reaction. | 0 | Metallurgy |
*CTSD can degrade insulin in hepatocytes
*CSTB May protect cell from leaking lysosomes
*LAMP1
*LAMP2
*M6PR | 1 | Gene expression + Signal Transduction |
Marion McQuillan (30 October 1921 – 24 June 1998) was a British metallurgist who specialised in the engineering uses for titanium and its alloys. She researched jet engine metals and was on the first team to research titanium for the Royal Aircraft Establishment Farnborough (RAE). | 0 | Metallurgy |
This process was the main process used in Britain from the mid-19th century until 1951. The process was very inefficient as it was designed as a small scale batch operation. Each retort only produced so companies would put them together in banks and used one large gas burner to heat all of them. The Belgian process requires redistillation to remove impurities of lead, cadmium, iron, copper, and arsenic. | 0 | Metallurgy |
The Hoopes process is a metallurgical process, used to obtain aluminium metal of very high purity (about 99.99% pure). The process was patented by William Hoopes, a chemist of the Aluminum Company of America (ALCOA), in 1925. | 0 | Metallurgy |
In metallurgy, recovery is a process by which a metal or alloys deformed grains can reduce their stored energy by the removal or rearrangement of defects in their crystal structure. These defects, primarily dislocations, are introduced by plastic deformation of the material and act to increase the yield strength of a material. Since recovery reduces the dislocation density, the process is normally accompanied by a reduction in a materials strength and a simultaneous increase in the ductility. As a result, recovery may be considered beneficial or detrimental depending on the circumstances.
Recovery is related to the similar processes of recrystallization and grain growth, each of them being stages of annealing. Recovery competes with recrystallization, as both are driven by the stored energy, but is also thought to be a necessary prerequisite for the nucleation of recrystallized grains. It is so called because there is a recovery of the electrical conductivity due to a reduction in dislocations. This creates defect-free channels, giving electrons an increased mean free path. | 0 | Metallurgy |
Transcriptional initiation, termination and regulation are mediated by “DNA looping” which brings together promoters, enhancers, transcription factors and RNA processing factors to accurately regulate gene expression. Chromosome conformation capture (3C) and more recently Hi-C techniques provided evidence that active chromatin regions are “compacted” in nuclear domains or bodies where transcriptional regulation is enhanced. The configuration of the genome is essential for enhancer-promoter proximity. Cell-fate decisions are mediated upon highly dynamic genomic reorganizations at interphase to modularly switch on or off entire gene regulatory networks through short to long range chromatin rearrangements. Related studies demonstrate that metazoan genomes are partitioned in structural and functional units around a megabase long called Topological association domains (TADs) containing dozens of genes regulated by hundreds of enhancers distributed within large genomic regions containing only non-coding sequences. The function of TADs is to regroup enhancers and promoters interacting together within a single large functional domain instead of having them spread in different TADs. However, studies of mouse development point out that two adjacent TADs may regulate the same gene cluster. The most relevant study on limb evolution shows that the TAD at the 5’ of the HoxD gene cluster in tetrapod genomes drives its expression in the distal limb bud embryos, giving rise to the hand, while the one located at 3’ side does it in the proximal limb bud, giving rise to the arm. Still, it is not known whether TADs are an adaptive strategy to enhance regulatory interactions or an effect of the constrains on these same interactions.
TAD boundaries are often composed by housekeeping genes, tRNAs, other highly expressed sequences and Short Interspersed Elements (SINE). While these genes may take advantage of their border position to be ubiquitously expressed, they are not directly linked with TAD edge formation. The specific molecules identified at boundaries of TADs are called insulators or architectural proteins because they not only block enhancer leaky expression but also ensure an accurate compartmentalization of cis-regulatory inputs to the targeted promoter. These insulators are DNA-binding proteins like CTCF and TFIIIC that help recruiting structural partners such as cohesins and condensins. The localization and binding of architectural proteins to their corresponding binding sites is regulated by post-translational modifications. DNA binding motifs recognized by architectural proteins are either of high occupancy and at around a megabase of each other or of low occupancy and inside TADs. High occupancy sites are usually conserved and static while intra-TADs sites are dynamic according to the state of the cell therefore TADs themselves are compartmentalized in subdomains that can be called subTADs from few kb up to a TAD long (19). When architectural binding sites are at less than 100 kb from each other, Mediator proteins are the architectural proteins cooperate with cohesin. For subTADs larger than 100 kb and TAD boundaries, CTCF is the typical insulator found to interact with cohesion. | 1 | Gene expression + Signal Transduction |
Initiation factor IF3 is a small protein of 21 kDa containing two compact α/β domains (IF3C and IF3N) connected by a flexible lysine-rich linker. Most IF3 functions are mediated by the IF3C domain, while IF3N regulates 30S subunit binding. Bacterial initiation factor 3 (infC) is not universally found in all bacterial species but in E. coli it is required for the 30S subunit to bind to the initiation site in mRNA. IF3 is required by the small subunit to form initiation complexes, but has to be released to allow the 50S subunit to bind. IF3 attaches to the platform side of the 30S subunit, close to helices 23, 24, 25, 26 and 45 of 16S rRNA, as well as ribosomal proteins S7, S11, and S12. The IF3C domain interacts with the 30S subunit via its conserved basic residues R99, R116, R147 and R168 . A major function of IF3 is inspecting codon-anticodon pairing at the P-site during start codon selection. It accelerates the dissociation of non-canonical initiation complexes containing mismatched or incorrect tRNAs. IF3 also inspects the initiator tRNA, rejecting elongator tRNAs and it also promotes the dissociation of the 70S ribosome into subunits, providing a pool of free 30S subunits for initiation. Another key role of IF3 is repositioning mRNA on the 30S subunit from a standby site to the P-site decoding site for start codon selection. IF3 works cooperatively with IF1 and IF2 during initiation and modulates IF2 binding and enhances the fidelity of start codon selection. | 1 | Gene expression + Signal Transduction |
A study demonstrates how the autocrine production of the IL-7 cytokine mediated by T-cell acute lymphoblastic leukemia (T-ALL) can be involved in the oncogenic development of T-ALL and offer novel insights into T-ALL spreading. | 1 | Gene expression + Signal Transduction |
Intermetallic particles often form during solidification of metallic alloys, and can be used as a dispersion strengthening mechanism. | 0 | Metallurgy |
Receptor-linked tyrosine kinases, such as the epidermal growth factor receptor (EGFR), are activated by extracellular ligands, such as the epidermal growth factor (EGF). Binding of EGF to the EGFR activates the tyrosine kinase activity of the cytoplasmic domain of the receptor. The EGFR becomes phosphorylated on tyrosine residues. Docking proteins such as GRB2 contain an SH2 domain that binds to the phosphotyrosine residues of the activated receptor. GRB2 binds to the guanine nucleotide exchange factor SOS by way of the two SH3 domains of GRB2. When the GRB2-SOS complex docks to phosphorylated EGFR, SOS becomes activated. Activated SOS then promotes the removal of GDP from a member of the Ras subfamily (most notably H-Ras or K-Ras). The Ras protein can then bind GTP and become active.
Apart from EGFR, other cell surface receptors that can activate this pathway via GRB2 include Trk A/B, Fibroblast growth factor receptor (FGFR) and PDGFR. | 1 | Gene expression + Signal Transduction |
In a two-dimensional isotropic material the grain boundary tension would be the same for the grains. This would give angle of 120° at GB junction where three grains meet. This would give the structure a hexagonal pattern which is the metastable state (or mechanical equilibrium) of the 2D specimen. A consequence of this is that, to keep trying to be as close to the equilibrium as possible, grains with fewer sides than six will bend the GB to try keep the 120° angle between each other. This results in a curved boundary with its curvature towards itself. A grain with six sides will, as mentioned, have straight boundaries, while a grain with more than six sides will have curved boundaries with its curvature away from itself. A grain with six boundaries (i.e. hexagonal structure) is in a metastable state (i.e. local equilibrium) within the 2D structure. In three dimensions structural details are similar but much more complex and the metastable structure for a grain is a non-regular 14-sided polyhedra with doubly curved faces. In practice all arrays of grains are always unstable and thus always grow until prevented by a counterforce.
Grains strive to minimize their energy, and a curved boundary has a higher energy than a straight boundary. This means that the grain boundary will migrate towards the curvature. The consequence of this is that grains with less than 6 sides will decrease in size while grains with more than 6 sides will increase in size.
Grain growth occurs due to motion of atoms across a grain boundary. Convex surfaces have a higher chemical potential than concave surfaces, therefore grain boundaries will move toward their center of curvature. As smaller particles tend to have a higher radius of curvature and this results in smaller grains losing atoms to larger grains and shrinking. This is a process called Ostwald ripening. Large grains grow at the expense of small grains.
Grain growth in a simple model is found to follow:
Here G is final average grain size, G is the initial average grain size, t is time, m is a factor between 2 and 4, and K is a factor given by:
Here Q is the molar activation energy, R is the ideal gas constant, T is absolute temperature, and K is a material dependent factor. In most materials the sintered grain size is proportional to the inverse square root of the fractional porosity, implying that pores are the most effective retardant for grain growth during sintering. | 0 | Metallurgy |
Queen's Metal, an alloy of nine parts tin and one each of antimony, lead, and bismuth, is intermediate in hardness between pewter and britannia metal. It was developed by English pewtersmiths in the 16th century; the recipe was initially a secret and was reserved for pieces made for the English royal family. | 0 | Metallurgy |
While traditional nucleic acid synthesis only uses 4 base pairs - adenine, thymine, guanine and cytosine, oligonucleotide synthesis in the future could incorporate the use of unnatural base pairs, which are artificially designed and synthesized nucleobases that do not occur in nature.
In 2012, a group of American scientists led by Floyd Romesberg, a chemical biologist at the Scripps Research Institute in San Diego, California, published that his team designed an unnatural base pair (UBP). The two new artificial nucleotides or Unnatural Base Pair (UBP) were named d5SICS and dNaM. More technically, these artificial nucleotides bearing hydrophobic nucleobases, feature two fused aromatic rings that form a (d5SICS–dNaM) complex or base pair in DNA. In 2014 the same team from the Scripps Research Institute reported that they synthesized a stretch of circular DNA known as a plasmid containing natural T-A and C-G base pairs along with the best-performing UBP Romesbergs laboratory had designed, and inserted it into cells of the common bacterium E. coli that successfully replicated the unnatural base pairs through multiple generations. This is the first known example of a living organism passing along an expanded genetic code to subsequent generations. This was in part achieved by the addition of a supportive algal gene that expresses a nucleotide triphosphate transporter which efficiently imports the triphosphates of both d5SICSTP and dNaMTP into E. coli' bacteria. Then, the natural bacterial replication pathways use them to accurately replicate the plasmid containing d5SICS–dNaM.
The successful incorporation of a third base pair is a significant breakthrough toward the goal of greatly expanding the number of amino acids which can be encoded by DNA, from the existing 20 amino acids to a theoretically possible 172, thereby expanding the potential for living organisms to produce novel proteins. In the future, these unnatural base pairs could be synthesised and incorporated into oligonucleotides via DNA printing methods. | 1 | Gene expression + Signal Transduction |
Bacterial anaerobic corrosion typically impacts metallic substrates but may also occur in concrete. Corrosion of concrete mediums leads to considerable losses in industrial settings. When considering the corrosion of concrete there is significant documentation of structural degradation in concrete wastewater infrastructure where wastewater is collected or treated. Similarly, biofilms are important for bacterial anaerobic corrosion of metals in wastewater pipes.
For bacterial anaerobic corrosion there is general corrosion of substrates as well as another form of corrosion known as pitting. In both general or pitting corrosion, the breakdown process occurs in aqueous conditions. Bacteria tend to form biofilms as their primary means of corroding metals, with different bacteria dominating across different settings. In municipal wastewater, Desulfovibrio desulfuricans is the main contributor to corrosion. | 0 | Metallurgy |
Tools and weapons, chisels and axe-heads, spearheads or dagger-blades, are the only surviving artifacts of the Copper Age, and do not show artistic treatment. But some Early Minoan pottery forms are plainly copied from metal prototypes, cups and jugs of simple construction and rather elaborate design. The cups are conical and sometimes a stem-foot; there are oval jars with long tubular spouts, and beaked jugs with round shoulders set on conical bodies. Heads of rivets which tie the metal parts together are often reproduced as a decorative element in clay. The spouted jars and pierced type of axe-head indicate that metallurgical connections of Early Minoan Crete were partly Mesopotamian. | 0 | Metallurgy |
In vertebrates, the region of the mRNA that codes for the signal peptide (i.e. the signal sequence coding region, or SSCR) can function as an RNA element with specific activities. SSCRs promote nuclear mRNA export and the proper localization to the surface of the endoplasmic reticulum. In addition SSCRs have specific sequence features: they have low adenine-content, are enriched in certain motifs, and tend to be present in the first exon at a frequency that is higher than expected. | 1 | Gene expression + Signal Transduction |
In 1985, MIM commissioned Jameson to undertake a project to improve the sparger design for flotation columns. Instead, he developed the concept of using a jet in a downcomer to create the bubbles and eliminate the need for a sparger in conventional flotation columns.
The concept of the Cell followed when further investigations showed that most of the bubble–particle interactions were occurring in the downcomer, rendering unnecessary the collection zone of flotation columns. The idea of the downcomer and short separation tank was developed and a provisional patent application was lodged in 1986. This patent was later assigned to TUNRA Limited ("TUNRA"), the technology transfer company of the University of Newcastle that is now known as "Newcastle Innovation".
A pilot two tonne per hour (t/h) Jameson Cell with a 100 mm downcomer and using an orifice plate to create the jet was tested in MIM's lead–zinc concentrator. Subsequently, in 1988, MIM tested the flotation of a stream of fine lead-bearing particles in a conventional mechanical flotation cell, a conventional column and the Jameson Cell. The Cell gave the best recoveries. This was thought to be a combination of the short residence time of the particles in the Cell and the fact that the hydrophobicity of the lead particles decreased over time.
As a result of this work, in 1989 MIM ordered four full-scale Cells, two for the Mount Isa lead–zinc concentrator and another two for the new Hilton lead–zinc concentrator to be built at the Hilton Mine, located about 20 kilometers north of Mount Isa. The Mount Isa cells had diameters of 1.9 m, with three downcomers each, while those at Hilton were 1.3 m in diameter and had two downcomers each. | 0 | Metallurgy |
The 600 or so subscribing members formed Industry Committees representing each of the main metal interests which discussed and agreed the topics for technical work to be done and a Council that controlled overall finances. Initially there was an annual government grant towards the work but this was changed to support funding for individual projects. When topics for research were agreed and funded by the industry they were then submitted to the government for approval of matching support funding but after the 1960s policy dictated that this became more and more difficult to obtain. The BNF also took on some contracts wholly sponsored by organisations which included some government departments. Individual technical enquiries from members were answered on a free and confidential basis. | 0 | Metallurgy |
Growth factor receptor-bound protein 2, also known as Grb2, is an adaptor protein involved in signal transduction/cell communication. In humans, the GRB2 protein is encoded by the GRB2 gene.
The protein encoded by this gene binds receptors such as the epidermal growth factor receptor and contains one SH2 domain and two SH3 domains. Its two SH3 domains direct complex formation with proline-rich regions of other proteins, and its SH2 domain binds tyrosine phosphorylated sequences. This gene is similar to the sem-5 gene of Caenorhabditis elegans, which is involved in the signal transduction pathway. Two alternatively spliced transcript variants encoding different isoforms have been found for this gene. | 1 | Gene expression + Signal Transduction |
*Spark plug
*Water cooled barrel
*Nitrogen inlet valve
*Fuel inlet valve
*Oxygen inlet valve
*Powder feedstock inlet valve | 0 | Metallurgy |
Retinal is bound to opsins, which are G protein-coupled receptors (GPCRs). Opsins, like other GPCRs, have seven transmembrane alpha-helices connected by six loops. They are found in the photoreceptor cells in the retina of eye. The opsin in the vertebrate rod cells is rhodopsin. The rods form disks, which contain the rhodopsin molecules in their membranes and which are entirely inside of the cell. The N-terminus head of the molecule extends into the interior of the disk, and the C-terminus tail extends into the cytoplasm of the cell. The opsins in the cone cells are OPN1SW, OPN1MW, and OPN1LW. The cones form incomplete disks that are part of the plasma membrane, so that the N-terminus head extends outside of the cell. In opsins, retinal binds covalently to a lysine in the seventh transmembrane helix through a Schiff base. Forming the Schiff base linkage involves removing the oxygen atom from retinal and two hydrogen atoms from the free amino group of lysine, giving HO. Retinylidene is the divalent group formed by removing the oxygen atom from retinal, and so opsins have been called retinylidene proteins.
Opsins are prototypical G protein-coupled receptors (GPCRs). Cattle rhodopsin, the opsin of the rod cells, was the first GPCR to have its amino acid sequence and 3D-structure (via X-ray crystallography) determined. Cattle rhodopsin contains 348 amino acid residues. Retinal binds as chromophore at Lys. This lysine is conserved in almost all opsins, only a few opsins have lost it during evolution. Opsins without the retinal binding lysine are not light sensitive. Such opsins may have other functions.
Although mammals use retinal exclusively as the opsin chromophore, other groups of animals additionally use four chromophores closely related to retinal: 3,4-didehydroretinal (vitamin A), (3R)-3-hydroxyretinal, (3S)-3-hydroxyretinal (both vitamin A), and (4R)-4-hydroxyretinal (vitamin A). Many fish and amphibians use 3,4-didehydroretinal, also called dehydroretinal. With the exception of the dipteran suborder Cyclorrhapha (the so-called higher flies), all insects examined use the (R)-enantiomer of 3-hydroxyretinal. The (R)-enantiomer is to be expected if 3-hydroxyretinal is produced directly from xanthophyll carotenoids. Cyclorrhaphans, including Drosophila, use (3S)-3-hydroxyretinal. Firefly squid have been found to use (4R)-4-hydroxyretinal. | 1 | Gene expression + Signal Transduction |
Electrolyte: The electrolyte is a molten bath of cryolite (NaAlF) and dissolved alumina. Cryolite is a good solvent for alumina with low melting point, satisfactory viscosity, and low vapour pressure. Its density is also lower than that of liquid aluminium (2 vs 2.3 g/cm), which allows natural separation of the product from the salt at the bottom of the cell. The cryolite ratio (NaF/AlF) in pure cryolite is 3, with a melting temperature of 1010 °C, and it forms a eutectic with 11% alumina at 960 °C. In industrial cells the cryolite ratio is kept between 2 and 3 to decrease its melting temperature to 940–980 °C.
Cathode: Carbon cathodes are essentially made of anthracite, graphite and petroleum coke, which are calcined at around 1200 °C and crushed and sieved prior to being used in cathode manufacturing. Aggregates are mixed with coal-tar pitch, formed, and baked. Carbon purity is not as stringent as for anode, because metal contamination from cathode is not significant. Carbon cathode must have adequate strength, good electrical conductivity and high resistance to wear and sodium penetration. Anthracite cathodes have higher wear resistance and slower creep with lower amplitude [15] than graphitic and graphitized petroleum coke cathodes. Instead, dense cathodes with more graphitic order have higher electrical conductivity, lower energy consumption [14], and lower swelling due to sodium penetration. Swelling results in early and non-uniform deterioration of cathode blocks.
Anode: Carbon anodes have a specific situation in aluminium smelting and depending on the type of anode, aluminium smelting is divided in two different technologies; “Soderberg” and “prebaked” anodes. Anodes are also made of petroleum coke, mixed with coal-tar-pitch, followed by forming and baking at elevated temperatures. The quality of anode affects technological, economical and environmental aspects of aluminium production. Energy efficiency is related to the nature of anode materials, as well as the porosity of baked anodes. Around 10% of cell power is consumed to overcome the electrical resistance of prebaked anode (50–60 μΩm). Carbon is consumed more than theoretical value due to a low current efficiency and non-electrolytic consumption. Inhomogeneous anode quality due to the variation in raw materials and production parameters also affects its performance and the cell stability.
Prebaked consumable carbon anodes are divided into graphitized and coke types. For manufacturing of the graphitized anodes, anthracite and petroleum coke are calcined and classified. They are then mixed with coal-tar pitch and pressed. The pressed green anode is then baked at 1200 °C and graphitized. Coke anodes are made of calcined petroleum coke, recycled anode butts, and coal-tar pitch (binder). The anodes are manufactured by mixing aggregates with coal tar pitch to form a paste with a doughy consistency. This material is most often vibro-compacted but in some plants pressed. The green anode is then sintered at 1100–1200 °C for 300–400 hours, without graphitization, to increase its strength through decomposition and carbonization of the binder. Higher baking temperatures increase the mechanical properties and thermal conductivity, and decrease the air and CO reactivity. The specific electrical resistance of the coke-type anodes is higher than that of the graphitized ones, but they have higher compressive strength and lower porosity.
Soderberg electrodes (in-situ baking), used for the first time in 1923 in Norway, are composed of a steel shell and a carbonaceous mass which is baked by the heat being escaped from the electrolysis cell. Soderberg Carbon-based materials such as coke and anthracite are crushed, heat-treated, and classified. These aggregates are mixed with pitch or oil as binder, briquetted and loaded into the shell. Temperature increases bottom to the top of the column and in-situ baking takes place as the anode is lowered into the bath. Significant amount of hydrocarbons are emitted during baking which is a disadvantage of this type of electrodes. Most of the modern smelters use prebaked anodes since the process control is easier and a slightly better energy efficiency is achieved, compared to Soderberg anodes. | 0 | Metallurgy |
As discussed by Jin and Roberston in their review, silencing of a DNA repair gene by hypermethylation may be a very early step in progression to cancer. Such silencing is proposed to act similarly to a germ-line mutation in a DNA repair gene, and predisposes the cell and its descendants to progression to cancer. Another review also indicated an early role for hypermethylation of DNA repair genes in cancer. If a gene necessary for DNA repair is hypermethylated, resulting in deficient DNA repair, DNA damages will accumulate. Increased DNA damage tends to cause increased errors during DNA synthesis, leading to mutations that can give rise to cancer.
If hypermethylation of a DNA repair gene is an early step in carcinogenesis, then it may also occur in the normal-appearing tissues surrounding the cancer from which the cancer arose (the field defect). See the table below.
While DNA damages may give rise to mutations through error prone translesion synthesis, DNA damages can also give rise to epigenetic alterations during faulty DNA repair processes. The DNA damages that accumulate due to hypermethylation of the promoters of DNA repair genes can be a source of the increased epigenetic alterations found in many genes in cancers.
In an early study, looking at a limited set of transcriptional promoters, Fernandez et al. examined the DNA methylation profiles of 855 primary tumors. Comparing each tumor type with its corresponding normal tissue, 729 CpG island sites (55% of the 1322 CpG island sites evaluated) showed differential DNA methylation. Of these sites, 496 were hypermethylated (repressed) and 233 were hypomethylated (activated). Thus, there is a high level of promoter methylation alterations in tumors. Some of these alterations may contribute to cancer progression. | 1 | Gene expression + Signal Transduction |
*Bayley, J. (1990) "The Production of Brass in Antiquity with Particular Reference to Roman Britain" in Craddock, P.T. (ed.) 2000 Years of Zinc and Brass London: British Museum
*Craddock, P.T. and Eckstein, K (2003) "Production of Brass in Antiquity by Direct Reduction" in Craddock, P.T. and Lang, J. (eds) Mining and Metal Production Through the Ages London: British Museum
*Day, J. (1990) "Brass and Zinc in Europe from the Middle Ages until the 19th century" in Craddock, P.T. (ed.) 2000 Years of Zinc and Brass London: British Museum
*Day, J (1991) "Copper, Zinc and Brass Production" in Day, J and Tylecote, R.F (eds) The Industrial Revolution in Metals London: The Institute of Metals
*Rehren, T. and Martinon Torres, M. (2008) "Naturam ars imitate: European brassmaking between craft and science" in Martinon-Torres, M and Rehren, T. (eds) Archaeology, History and Science Integrating Approaches to Ancient Material: Left Coast Press | 0 | Metallurgy |
In most cases Type 1 pitting can be avoided by good working practices. Always use tubes that have been manufactured to BS EN 1057. Tubes greater than 10 mm in diameter made to this standard will always be marked the number of the standard, the nominal size, wall thickness and temper of the tube, the manufacturer’s identification mark and the date of production at least every 600 mm. Tubes less than 10 mm in diameter will be similarly marked at each end.
Once a system has been commissioned it should be either put immediately into service or drained down and dried. If either of these options is not possible then the system should be flushed though regularly until it is put into use. It should not be left to stand for more than a week. At present stagnation is the most common cause of Type 1 pitting.
Flux should be used sparingly. A small quantity should be painted over the areas to be joined and any excess removed after the joint has been made. Some fluxes are marked as water-soluble but under some circumstances they are not removed before pitting has initiated. | 0 | Metallurgy |
Internal corrosion is occasioned by the combined effects and severity of four modes of material deterioration, namely: general corrosion, pitting corrosion, microbial corrosion, and fluid corrosivity. The same principals of external corrosion control can be applied to internal corrosion but due to accessibility, the approaches can be different. Thus special instruments for internal corrosion control and inspection are used that are not used in external corrosion control. Video scoping of pipes and high tech smart pigs are used for internal inspections. The smart pigs can be inserted into a pipe system at one point and "caught" far down the line. The use of corrosion inhibitors, material selection, and internal coatings are mainly used to control corrosion in piping while anodes along with coatings are used to control corrosion in tanks.
Internal corrosion challenges apply to the following amongst others: Water pipes; Gas pipes; Oil pipes and Water tank reservoirs. | 0 | Metallurgy |
The severity of injuries to the mucosa of the gastrointestinal tract is commonly rated using the Zargar criteria. | 0 | Metallurgy |
Interferome is managed by a team at Monash University :Monash Institute of Medical Research and the University of Cambridge | 1 | Gene expression + Signal Transduction |
REST/NRSF in conjunction with RE1/NRSE also acts outside the nervous system as regulators and repressors. Current research has linked RE1/NRSE activity with the regulation of the expression of the atrial natriuretic peptide (ANP) gene. An NRSE regulatory region is present in the 3’ untranslated region of the ANP gene and acts as a mediator for its appropriate expression. The protein encoded by the ANP gene is important during embryonic development for the maturation and development of cardiac myocytes. However, during early childhood and throughout adulthood, ANP expression is suppressed or kept to a minimum in the ventricle. Thus, an abnormal induction of the ANP gene can lead to ventricular hypertrophy and severe cardiac consequences. In order to maintain the repression of the gene, NRSF (neuron-restrictive silencer factor) or REST binds to the NRSE region in the 3’untranslated region of the ANP gene. Furthermore, the NRSF-NRSE complex recruits a transcriptional corepressor known as mSin3. This leads to the activity of histone deacetylase in the region and the repression of the gene. Therefore, studies have revealed the correlation between REST/NRSF and RE1/NRSE in regulating the ANP gene expression in ventricular myocytes. A mutation in either the NRSF or NRSE can lead to an undesirable development of ventricular myocytes, due to lack of repression, which can then cause ventricular hypertrophy. Left ventricular hypertrophy, for example, increases an individuals chance of sudden death due to a ventricular arrhythmia resulting from the increased ventricular mass. In addition to the influence on the ANP' gene, the NRSE sequence regulates other cardiac embryonic genes, such as brain natriuretic peptide BNP, skeletal α-actin, and Na, K – ATPase α3 subunit. Hence, the regulatory activity of both NRSE and NRSF in mammals prevents not only neural dysfunctions but also physiological and phenotypical abnormalities in other non-neuronal regions of the body. | 1 | Gene expression + Signal Transduction |
The role of PA in the cell can be divided into three categories:
* PA is the precursor for the biosynthesis of many other lipids.
* The physical properties of PA influence membrane curvature.
* PA acts as a signaling lipid, recruiting cytosolic proteins to appropriate membranes (e.g., sphingosine kinase 1).
* PA plays very important role in phototransduction in Drosophila.
* PA is a lipid ligand that gates ion channels. See also lipid-gated ion channels.
The first three roles are not mutually exclusive. For example, PA may be involved in vesicle formation by promoting membrane curvature and by recruiting the proteins to carry out the much more energetically unfavourable task of neck formation and pinching. | 1 | Gene expression + Signal Transduction |
Amongst members of the ETS family, there is extensive conservation in the DNA-binding ETS domain and, therefore, a lot of redundancy in DNA binding. It is thought that interactions with other proteins (eg: Modulator of the activity of Ets called Mae) is one way in which specific binding to DNA is achieved. Transcription factor Ets are a site of signalling convergence.
ETS factors act as transcriptional repressors, transcriptional activators, or both. | 1 | Gene expression + Signal Transduction |
CTCF binds to itself to form homodimers. CTCF has also been shown to interact with Y box binding protein 1. CTCF also co-localizes with cohesin, which extrudes chromatin loops by actively translocating one or two DNA strands through its ring-shaped structure, until it meets CTCF in a proper orientation. CTCF is also known to interact with chromatin remodellers such as Chd4 and Snf2h (SMARCA5). | 1 | Gene expression + Signal Transduction |
Another example of a demethylase is protein-glutamate methylesterase, also known as CheB protein (EC 3.1.1.61), which demethylates MCPs (methyl-accepting chemotaxis proteins) through hydrolysis of carboxylic ester bonds. The association of a chemotaxis receptor with an agonist leads to the phosphorylation of CheB. Phosphorylation of CheB protein enhances its catalytic MCP demethylating activity resulting in adaption of the cell to environmental stimuli. MCPs respond to extracellular attractants and repellents in bacteria like E. coli in chemotaxis regulation. CheB is more specifically termed a methylesterase, as it removes methyl groups from methylglutamate residues located on the MCPs through hydrolysis, producing glutamate accompanied by the release of methanol.
CheB is of particular interest to researchers as it may be a therapeutic target for mitigating the spread of bacterial infections. | 1 | Gene expression + Signal Transduction |
*Bayley, J. 1995. Precious Metal Refining, in Historical Metallurgy Society Datasheets: https://web.archive.org/web/20160418021923/http://hist-met.org/hmsdatasheet02.pdf (accessed January 13, 2010)
*Bayley, J. 2008 Medieval precious metal refining: archaeology and contemporary texts compared, in Martinón-Torres, M and Rehren, Th (eds) Archaeology, history and science: integrating approaches to ancient materials by. Left Coast Press: 131-150.
*[http://ifc.dpz.es/recursos/publicaciones/26/10/_ebook.pdf Bayley, J.,Eckstein, K. 2006. Roman and medieval litharge cakes: structure and composition, in J. Pérez-Arantegui (ed) Proc. 34th Int. Symposium on Archaeometry. Institución Fernando el Católito, CSIC, Zaragoza: 145-153. (PDF)]
*Bayley, J., Rehren, Th. 2007. Towards a functional and Typological classification of crucibles, in La Niece, S and Craddock, P (eds) Metals and Mines. Studies in Archaeometallurgy. Archetype Books: 46-55
*Bayley, J., Crossley, D. and Ponting, M. (eds). 2008. Metals and Metalworking. A research framework for archaeometallurgy. Historical Metallurgy Society 6.
*Craddock, P. T. 1991. Mining and smelting in Antiquity, in Bowman, S. (ed), Science and the Past, London: British Museum Press: 57-73..
*Craddock, P. T. 1995. Early metal mining and production. Edinburgh: Edinburgh University Press.
*Hoover, H. and Hoover, H. 1950 [1556]. Georgius Agricola De Re Metallica. New York: Dover.
*Howe, E., Petersen, U. 1994. Silver and Lead in late Prehistory of the Montaro Valley, Peru. In Scott, D., and Meyers P. (eds.) Archaeometry of Pre-Columbian Sites and Artifacts: 183-197. The Getty Conservation Institute.
*[http://www.ancientgreece.com/essay/v/laurion_and_thorikos/ Laurion and Thorikos] (accessed January 15, 2010)
*Jones, G.D. 1980. The Roman Mines at Riotinto, in The Journal of Roman Studies 70: 146-165. Society for the promotion of Roman Studies.
*Jones, D. (ed) 2001. Archaeometallurgy. Centre for Archaeological Guidelines. English Heritage publications. London.
*Karsten, H., Hauptmann, H., Wright, H., Whallon, R. 1998. Evidence of fourth millennium BC silver production at Fatmali-Kalecik, East Anatolia. in Metallurgica Antiqua: in honour of Hans-Gert Bachmann and Robert Maddin by Bachmann, H. G, Maddin, Robert, Rehren, Thilo, Hauptmann, Andreas, Muhly, James David, Deutsches Bergbau-Museum: 57-67
*Kassianidou, V. 2003. Early Extraction of Silver from Complex Polymetallic Ores, in Craddock, P.T. and Lang, J (eds) Mining and Metal production through the Ages. London, British Museum Press: 198-206
*Lechtman, H. 1976. A metallurgical site survey in the Peruvian Andes, in Journal of field Archaeology 3 (1): 1-42.
*Martinón-Torres, M., Rehren, Th. 2005a. Ceramic materials in fire assay practices: a case study of 16th-century laboratory equipment, in M. I. Prudencio, M. I. Dias and J. C. Waerenborgh (eds), Understanding people through their pottery, 139-149 (Trabalhos de Arqueologia 42). Lisbon: Instituto Portugues de Arqueologia.
*Martinón-Torres, M., Rehren, Th. 2005b. Alchemy, chemistry and metallurgy in Renaissance Europe. A wider context for fire assay remains, in Historical Metallurgy: journal of the Historical Metallurgy Society, 39(1): 14-31.
*Martinón-Torres, M., Rehren, Th., Thomas, N., Mongiatti, A. 2009. Identifying materials, recipes and choices: Some suggestions for the study of Archaeological cupels. In Giumla-Mair, A. et al., Archaeometallurgy in Europe: 1-11 Milan: AIM
*Pernicka, E., Rehren, Th., Schmitt-Strecker, S. 1998. Late Uruk silver production by cupellation at Habuba Kabira, Syria in Metallurgica Antiqua : in honour of Hans-Gert Bachmann and Robert Maddin by Bachmann, H. G, Maddin, Robert, Rehren, Thilo, Hauptmann, Andreas, Muhly, James David, Deutsches Bergbau-Museum: 123-134.
*Rehren, Th.1996. Alchemy and Fire Assay – An Analytical Approach, in Historical Metallurgy 30: 136-142.
*Rehren, Th. 2003. Crucibles as reaction vessels in ancient metallurgy, in P.T. Craddock and J. Lang (eds), Mining and Metal Production through the Ages, 207-215. London. The British Museum Press.
*Rehren, Th., Eckstein, K 2002. The development of analytical cupellation in the Middle Ages, in E Jerem and K T Biró (eds) Archaeometry 98. Proceedings of the 31 st Symposium, Budapest, April 26 – May 3, 1998 (Oxford BAR International Series 1043 – Central European Series 1), 2: 445-448.
*Rehren, Th., Schneider, J., Bartels, Chr. 1999. Medieval lead-silver smelting in the Siegerland, West Germany. In Historical Metallurgy: journal of the Historical Metallurgy Society. 33: 73-84. Sheffield: Historical Metallurgy Society.
*Tylecote, R.F. 1992. A History of Metallurgy. Second Edition Maney for the Institute of Materials. London.
*Van Buren, M., Mills, B. 2005. Huayrachinas and Tocochimbos: Traditional Smelting Technology of the Southern Andes, in Latin American Antiquity 16(1):3-25
*Wood J. R., Hsu, Y-T and Bell, C. 2021 Sending Laurion Back to the Future: Bronze Age Silver and the Source of Confusion, Internet Archaeology 56. https://doi.org/10.11141/ia.56.9 | 0 | Metallurgy |
Thomas and George Cranege (also spelled Cranage), who worked in the ironworking industry in England in the 1760s, are notable for introducing a new method of producing wrought iron from pig iron. | 0 | Metallurgy |
The increased complexity of the phosphorelay system compared to orthodox two-component signaling provides additional opportunities for regulation and improves the specificity of the response. Although there is very little cross-talk between orthodox two-component systems, phosphorelays allow more complex signaling pathways; examples include a bifurcated pathway with multiple downstream outputs, as in the case of the Caulobacter crescentus ChpT HPt involved in cell cycle regulation, or, alternatively, pathways in which more than one histidine kinase controls a single response regulator, such as the sporulation pathway in Bacillus subtilis, which can give rise to complex temporal variations. In some known cases, there is an additional form of regulation in phosphohistidine phosphatase enzymes that act on HPt, such as the Escherichia coli protein SixA which targets ArcB. | 1 | Gene expression + Signal Transduction |
The gonadotropin receptors are a group of receptors that bind a group of pituitary hormones called gonadotropins. They include the:
* Follicle-stimulating hormone receptor (FSHR) - binds follicle-stimulating hormone (FSH)
* Luteinizing hormone receptor (LHR) - binds luteinizing hormone (LH) and human chorionic gonadotropin (hCG) | 1 | Gene expression + Signal Transduction |
The atomization of molten materials produces a large amount of dust and fumes made up of very fine particles (ca. 80–95% of the particles by number <100 nm). Proper extraction facilities are vital not only for personal safety, but to minimize entrapment of re-frozen particles in the sprayed coatings. The use of respirators fitted with suitable filters is strongly recommended where equipment cannot be isolated.
Certain materials offer specific known hazards:. The Toxicity from thermal spray aerosols is dependent on the metal profile of the thermal spray.
#Finely divided metal particles are potentially pyrophoric and harmful when accumulated in the body.
#Certain materials e.g. aluminum, zinc and other base metals may react with water to evolve hydrogen. This is potentially explosive and special precautions are necessary in fume extraction equipment.
#Fumes of certain materials, notably zinc and copper alloys, have a disagreeable odour and may cause a fever-type reaction in certain individuals (known as metal fume fever). This may occur some time after spraying and usually subsides rapidly. If it does not, medical advice must be sought.
#Fumes of reactive compounds can dissociate and create harmful gasses. Respirators should be worn in these areas and gas meters should be used to monitor the air before respirators are removed. | 0 | Metallurgy |
The preinitiation complex, which contains a mediator, transcription factors, a nucleosome and RNA polymerase II, is important to position the polymerase for the start of transcription. Before RNA synthesis can occur, the polymerase must dissociate from mediator. This appears to be accomplished by phosphorylation of part of the polymerase by a kinase. Importantly, mediator and transcription factors do not dissociate from the DNA at the time polymerase begins transcription. Rather, the complex remains at the promoter to recruit another RNA polymerase to begin another round of transcription.
There is some evidence to suggest that mediator in a yeast is involved in regulating RNA polymerase III (Pol III) transcripts of tRNAs In support of that evidence, an independent report showed specific association of mediator with Pol III in Saccharomyces cerevisiae. Those authors also reported specific associations with RNA polymerase I and proteins involved in transcription elongation and RNA processing, supporting other evidence of mediator's involvement in elongation and processing. | 1 | Gene expression + Signal Transduction |
B. subtilis is a soil-dwelling microbe that uses quorum sensing to regulate two different biological processes: competence and sporulation. During stationary growth phase when B. subtilis are at high cell density, approximately 10% of the cells in a population are induced to become competent. It is believed that this subpopulation becomes competent to take up DNA that could potentially be used for the repair of damaged (mutated) chromosomes. ComX (also known as competence factor) is a 10-amino acid peptide that is processed from a 55-amino acid peptide precursor. Like most autoinducers, ComX is secreted and accumulates as a function of cell density. Once a threshold extracellular level is achieved, ComX is detected by a two-component ComP/ComA sensor kinase/response regulator pair. Phosphorylation of ComA activates the expression of comS gene, ComS inhibits the degradation of ComK, and finally ComK activates the expression of a number of genes required for competence.
Sporulation, on the other hand, is a physiological response of B. subtilis to depletion of nutrients within a particular environment. It is also regulated by extracellular signaling. When B. subtilis populations sense waning conditions, they respond by undergoing asymmetric cell division. This ultimately produces spores that are adapted for dispersal and survival in unfavorable conditions. Sporulation in B. subtilis is mediated by CSF (sporulation factor), a pentapeptide cleaved from the precursor peptide PhrC. CSF is secreted into the extracellular environment and is taken back up into cells via the ABC transporter Opp where it acts intracellularly. While low internal concentrations of CSF contribute to competence, high concentrations induce sporulation. CSF inhibits a phosphatase, RabB, which increases the activity of Spo0A, favoring a switch in commitment from competence to the sporulation pathway | 1 | Gene expression + Signal Transduction |
Mars Guy Fontana graduated with a Bachelor of Science followed by a Master of Science and then awarded a Doctor of Philosophy in the field of metallurgical engineering from the University of Michigan. He was known as a researcher/engineer who added to the field of knowledge in the fairly specialized area of corrosion and its various applications in engineering – corrosion engineering. As well as writing numerous papers he wrote the textbook Corrosion Engineering which was first published in 1967 ; there have been a number of updated editions since then. This book has been used as the primary textbook and recommended reading for at least one highly ranked University masters degree course. In his lifetime he wrote many papers in various scientific and engineering journals/periodicals. He also authored Corrosion: A Compilation.
In the late 1940s, he was given the chair in the Corrosion Center at Ohio State University. At the time it was the largest university corrosion research department in the United States. He combined the disciplines of engineering design, Material Science and Corrosion so they could be viewed together.
His contribution at the university was of such significance that he has a building named after him - the Fontana Laboratories. He also has a professorship named after him. | 0 | Metallurgy |
The measure of the promoter activity has a broad meaning. The promoter activity could be measured for different situations or research questions, such as:
* estimation of the level of expression in comparison (relative) to some known value
* how fast a gene is expressed after induction
* the timing of expression relative to others genes
* the specific spatial location of expression
Methods to study promoter activity commonly are based in the expression of a reporter gene from the promoter of the gene of interest. Mutations and deletions are made in a promoter region, and their changes on couple expression of the reporter gene are measured.
The most important reporter genes are the fluorescence proteins as GFP. These reporters allow to measure promoter activation by increasing fluorescent signals, and deactivation by decrease in the rate of fluorescence. | 1 | Gene expression + Signal Transduction |
Swamy and Jurjees (1986) have pointed out the limitations of sulfur concrete. They questioned the stability and the long-term durability of sulfur concrete beams with steel reinforcement, especially for sulfur concrete modified with dicyclopentadiene and dipentene. Even when dry, modified concrete beams show strength loss with ageing. Ageing in a wet environment leads to softening of sulfur concrete and loss of strength. It causes structural damages in sulfur concrete beams leading to shear failures and cracking. Swamy and Jurjees (1986) also observed severe corrosion of steel reinforcements. They concluded that the stability of reinforced sulfur concrete beams can only be guaranteed when they are unmodified and kept dry.
Being based on the use of elemental sulfur (S, or S) as a binder, sulfur concrete applications are expected to suffer the same limitations as those of elemental sulfur which is not a really inert material, can burn, and is also known to be a potent corrosive agent.
In case of fire, this concrete is flammable and will generate toxic and corrosive fumes of sulfur dioxide (), and sulfur trioxide (), ultimately leading to the formation of sulfuric acid ().
According to Maldonado-Zagal and Boden (1982), the hydrolysis of elemental sulfur (octa-atomic sulphur, S) in water is driven by its disproportionation into oxidised and reduced forms in the ratio / = 3/1. Hydrogen sulfide () causes sulfide stress cracking (SSC) and in contact with air is also easily oxidized into thiosulfate (), responsible for pitting corrosion.
Like pyrite (, iron(II) disulfide), in the presence of moisture, sulfur is also sensitive to oxidation by atmospheric oxygen and could ultimately produce sulfuric acid (), sulfate (), and intermediate chemical species such as thiosulfates (), or tetrathionates (), which are also strongly corrosive substances (pitting corrosion), as all the reduced species of sulfur. Therefore, long-term corrosion problems of steels and other metals (aluminium, copper...) need to be anticipated, and correctly addressed, before selecting sulfur concrete for specific applications.
The formation of sulfuric acid could also attack and dissolve limestone () and concrete structures while also producing expansive gypsum (), aggravating the formation of cracks and fissures in these materials.
If the local physico-chemical conditions are conducive (sufficient space and water available for their growth), sulfur-oxidizing bacteria (microbial oxidation of sulfur) could also thrive at the expense of concrete sulfur and contribute to aggravate potential corrosion problems.
The degradation rate of elemental sulfur depends on its specific surface area. The degradation reactions are the fastest with sulfur dust, or crushed powder of sulfur, while intact compact blocks of sulfur concrete are expected to react more slowly. The service life of components made of sulfur concrete depends thus on the degradation kinetics of elemental sulfur exposed to atmospheric oxygen, moisture and microorganisms, on the density/concentration of microcracks in the material, and on the accessibility of the carbon-steel surface to the corrosive degradation products present in aqueous solution in case of macrocracks or technical voids exposed to water ingress. All these factors need to be taken into account when designing structures, systems and components (SSC) based on sulfur concrete, certainly if they are reinforced, or pre-stressed, with steel elements (rebar or tensioning cables respectively).
While the process of elemental sulfur oxidation will also lower the pH value, aggravating carbon steel corrosion, in contrast to ordinary Portland cement and classical concrete, fresh sulfur concrete does not contain alkali hydroxides (KOH, NaOH), nor calcium hydroxide (), and therefore does not provide any buffering capacity to maintain a high pH passivating the steel surface. In other words, intact sulfur concrete does not chemically protect steel reinforcement bars (rebar) against corrosion. The corrosion of steel elements embedded into sulfur concrete will thus depends on water ingress through cracks and to their exposure to aggressive chemical species of sulfur dissolved in the seeping water. The presence of microorganisms fuelled by elemental sulfur could also play a role and accelerate the corrosion rate. | 0 | Metallurgy |
T4 bacteriophage uses anti-sigma factor to ruin the Escherichia coli polymerase in order that direct exclusive transcription of its own genes.
AsiA is an anti-sigma factor gene that is required for bacteriophage T4 to be developed). Which means that AsiA is an essential anti-sigma factor in bacteriophage. | 1 | Gene expression + Signal Transduction |
Methylations are epigenetic modification that, in eukaryotes, regulates processes as cell differentiation, and embryogenesis, while in prokaryotes can have a role in self recognition, protecting the DNA from being cleaved by the restriction endonuclease system, or for gene regulation. The first function is controlled by the restriction methylation system while the second by Orphan MTases as Dam and CcrM.
CcrM role have been characterized in the marine model organism Caulobacter crescentus, which is suitable for the study of cell cycle and epigenetics as it asymmetrically divides generating different progeny, a stalked and a swarmer cell, with different phenotypes and gene regulation. The swarmer cell has a single flagellum and polar pili and is characterized by its mobility, while the stacked cell has a stalk and is fixed to the substrate. The stacked cell enters immediately in S-phase, while the swarmer cell stays in G1-phase and will differentiate to a stacked cell before entering the S-phase again.
The stacked cell in S phase will replicate its DNA in a semiconservative manner producing two hemimethylated DNA double strands that will be rapidly methylated by the Methyltransferase CcrM, which is only produced at the end of the S phase. The enzyme will methylate more than 4 thousand 5-GANTC-3 sites in around 20 minutes, and then it will be degraded by the LON protease. This fast methylation plays an important role in the transcriptional control of several genes and controls the cell differentiation. CcrM expression is regulated by the CtrA master regulator, and in addition various 5-GANTC-3 sites methylation sites regulate CcrM expression, which will only occur at the end of the S phase when this sites are hemimethylated. In this process CtrA regulates the expression of CcrM and more than 1000 genes in the pre-divisional state, and SciP prevents the activation of CcrM transcription in non replicative cells. | 1 | Gene expression + Signal Transduction |
A bar of brass (70% Cu, 30% Zn) was used as a core, with molybdenum wires stretched along its length, and then coated in a layer of pure copper. Molybdenum was chosen as the marker material due to it being very insoluble in brass, eliminating any error due to the markers diffusing themselves. Diffusion was allowed to take place at 785 °C over the course of 56 days, with cross-sections being taken at six times throughout the span of the experiment. Over time, it was observed that the wire markers moved closer together as the zinc diffused out of the brass and into the copper. A difference in location of the interface was visible in cross sections of different times. Compositional change of the material from diffusion was confirmed by x-ray diffraction. | 0 | Metallurgy |
Eyeglass frames made from titanium-containing SMAs are marketed under the trademarks Flexon and TITANflex. These frames are usually made out of shape-memory alloys that have their transition temperature set below the expected room temperature. This allows the frames to undergo large deformation under stress, yet regain their intended shape once the metal is unloaded again. The very large apparently elastic strains are due to the stress-induced martensitic effect, where the crystal structure can transform under loading, allowing the shape to change temporarily under load. This means that eyeglasses made of shape-memory alloys are more robust against being accidentally damaged. | 0 | Metallurgy |
Due to the proximity of the Westinghouse site and other former manufacturing sites to the Watsessing Station, the Township of Bloomfield worked on the plan for transit-oriented development in that area. The Westinghouse site, although a brownfield site with ongoing remediation at the time, was re-zoned into Commuter Oriented Residential District which was a mixed-use concept that included high-density residential units which would be close to the train station.
The redevelopment was completed. The luxury apartments were marketed as "The Grove at Watsessing" which was part of the "Grove Crossing" complex. | 0 | Metallurgy |
Subsets and Splits