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Some mutations that lead to this disorder are:
# a Cytosine (C) to Guanine (G) substitution which converts a tyrosine to stop codon
# a 39 base pair deletion
# a 2 base pair deletion which creates an early stop codon
Endoglin levels have been found to be elevated in pregnant women who subsequently develop preeclampsia. | 1 | Gene expression + Signal Transduction |
An anodized oxide layer has a thickness in the range of to several micrometers. Standards for titanium anodizing are given by AMS 2487 and AMS 2488.
AMS 2488 Type III anodizing of titanium generates an array of different colours without dyes, for which it is sometimes used in art, costume jewellery, body piercing jewellery and wedding rings. The colour formed is dependent on the thickness of the oxide (which is determined by the anodizing voltage); it is caused by the interference of light reflecting off the oxide surface with light travelling through it and reflecting off the underlying metal surface. AMS 2488 Type II anodizing produces a thicker matte grey finish with higher wear resistance. | 0 | Metallurgy |
Transcriptome instability is a genome-wide, pre-mRNA splicing-related characteristic of certain cancers. In general, pre-mRNA splicing is dysregulated in a high proportion of cancerous cells. For certain types of cancer, like in colorectal and prostate, the number of splicing errors per cancer has been shown to vary greatly between individual cancers, a phenomenon referred to as transcriptome instability. Transcriptome instability correlates significantly with reduced expression level of splicing factor genes. Mutation of DNMT3A contributes to development of hematologic malignancies, and DNMT3A-mutated cell lines exhibit transcriptome instability as compared to their isogenic wildtype counterparts. | 1 | Gene expression + Signal Transduction |
Oxidised copper ores include carbonates such as azurite and malachite, the silicate chrysocolla, and sulfates such as atacamite. In some cases, sulfide ores are allowed to degrade to oxides. Such ores are amenable to hydrometallurgy. Specifically, such oxide ores are usually extracted into aqueous sulfuric acid, usually in a heap leaching or dump leaching. The resulting pregnant leach solution is purified by solvent extraction (SX). It is treated with an organic solvent and an organic chelators. The chelators bind the copper ions (and no other ions, ideally), the resulting complexes dissolve in the organic phase. This organic solvent is evaporated, leaving a residue of the copper complexes. The copper ions are liberated from the residue with sulfuric acid. The barred (denuded) sulfuric acid recycled back on to the heaps. The organic ligands are recovered and recycled as well. Alternatively, the copper can be precipitated out of the pregnant solution by contacting it with scrap iron; a process called cementation. Cement copper is normally less pure than SX-EW copper. | 0 | Metallurgy |
The 17-bp transcriptional complex has an 8-bp DNA-RNA hybrid, that is, 8 base-pairs involve the RNA transcript bound to the DNA template strand. As transcription progresses, ribonucleotides are added to the 3′ end of the RNA transcript and the RNAP complex moves along the DNA. The characteristic elongation rates in prokaryotes and eukaryotes are about 10–100 nts/sec.
Aspartyl (asp) residues in the RNAP will hold on to Mg ions, which will, in turn, coordinate the phosphates of the ribonucleotides. The first Mg will hold on to the α-phosphate of the NTP to be added. This allows the nucleophilic attack of the 3′-OH from the RNA transcript, adding another NTP to the chain. The second Mg will hold on to the pyrophosphate of the NTP. The overall reaction equation is:
:(NMP) + NTP → (NMP) + PP | 1 | Gene expression + Signal Transduction |
FAIRE uses the biochemical properties of protein-bound DNA to separate nucleosome-depleted regions in the genome. Cells will be subjected to cross-linking, ensuring that the interaction between the nucleosomes and DNA are fixed. After sonication, the fragmented and fixed DNA is separated using a phenol-chloroform extraction. This method creates two phases, an organic and an aqueous phase. Due to their biochemical properties, the DNA fragments cross-linked to nucleosomes will preferentially sit in the organic phase. Nucleosome depleted or ‘open’ regions on the other hand will be found in the aqueous phase. By specifically extracting the aqueous phase, only nucleosome-depleted regions will be purified and enriched. | 1 | Gene expression + Signal Transduction |
* Amit Chatterjee, Sponge Iron Production By Direct Reduction Of Iron Oxide, PHI Learning Private Limited, 2010, 353 p. (, [https://books.google.fr/books?id=IcT6-tg1uz4C&printsec=frontcover read online] [https://archive.wikiwix.com/cache/?url=https%3A%2F%2Fbooks.google.fr%2Fbooks%3Fid%3DIcT6-tg1uz4C%26printsec%3Dfrontcover archive])
* "[http://www.ecacwb.org/editor_upload/files/Process%20Technology.pdf Process technology followed for sponge iron]" [https://archive.wikiwix.com/cache/?url=http%3A%2F%2Fwww.ecacwb.org%2Feditor_upload%2Ffiles%2FProcess%2520Technology.pdf archive], Environment Compliance Assistance Centre (ECAC)
* "[http://www.recyclingtoday.com/news/images/dri.pdf World direct reduction statistics]" [https://web.archive.org/web/20050829184014/http://www.recyclingtoday.com/news/images/dri.pdf archive of August 29th, 2005], Midrex, 2001.
* "[http://www.midrex.com/uploads/documents/MDX%20STATS%202012%207-3-13Final.pdf World direct reduction statistics] " [https://archive.wikiwix.com/cache/?url=http%3A%2F%2Fwww.midrex.com%2Fuploads%2Fdocuments%2FMDX%2520STATS%25202012%25207-3-13Final.pdf archive], Midrex, 2012.
* J. Feinman, "[http://jpkc.gsut.edu.cn/upload/20120523/20120523181034985.pdf Direct Reduction and Smelting Processes] " [https://archive.wikiwix.com/cache/?url=http%3A%2F%2Fjpkc.gsut.edu.cn%2Fupload%2F20120523%2F20120523181034985.pdf archive], The AISE Steel Foundation, 1999.
* "[http://ietd.iipnetwork.org/content/direct-reduced-iron Direct Reduced Iron] " [https://archive.wikiwix.com/cache/?url=http%3A%2F%2Fietd.iipnetwork.org%2Fcontent%2Fdirect-reduced-iron archive], The Institute for Industrial Productivity. | 0 | Metallurgy |
This style is traditional to suburbs of Philadelphia, Pennsylvania, including Chester, Bucks, and Montgomery Counties. The amount of the required offset is divided evenly between the hinge and the pintle. | 0 | Metallurgy |
Global steel production grew enormously in the 20th century from a mere 28 million tonnes at the beginning of the century to 781 million tons at the end. Per-capita steel consumption in the US peaked in 1977, then fell by half before staging a modest recovery to levels well below the peak. | 0 | Metallurgy |
CTCF insulators affect the expression of genes implicated in cell cycle regulation processes that are important for cell growth, cell differentiation, and programmed cell death (apoptosis). Two of these cell cycle regulation genes that are known to interact with CTCF are hTERT and C-MYC. In these cases, a loss of function mutation to the CTCF insulator gene changes the expression patterns and may affect the interplay between cell growth, differentiation and apoptosis and lead to tumourigenesis or other problems.
CTCF is also required for the expression of tumour repressor retinoblastoma (Rb) gene and mutations and deletions of this gene are associated with inherited malignancies. When the CTCF binding site is removed expression of Rb is decreased and tumours are able to thrive.
Other genes that encode cell cycle regulators include BRCA1, and p53, which are growth suppressors that are silenced in many cancer types, and whose expression is controlled by CTCF. Loss of function of CTCF in these genes leads to the silencing of the growth suppressor and contributes to the formation of cancer.
The aberrant activation of insulators can modulate the expression of cancer-related genes, including matrix metalloproteinases involved in cancer cell invasion. | 1 | Gene expression + Signal Transduction |
ADAM17 is understood to be involved in the processing of tumor necrosis factor alpha (TNF-α) at the surface of the cell, and from within the intracellular membranes of the trans-Golgi network. This process, which is also known as shedding, involves the cleavage and release of a soluble ectodomain from membrane-bound pro-proteins (such as pro-TNF-α), and is of known physiological importance. ADAM17 was the first sheddase to be identified, and is also understood to play a role in the release of a diverse variety of membrane-anchored cytokines, cell adhesion molecules, receptors, ligands, and enzymes.
Cloning of the TNF-α gene revealed it to encode a 26 kDa type II transmembrane pro-polypeptide that becomes inserted into the cell membrane during its maturation. At the cell surface, pro-TNF-α is biologically active, and is able to induce immune responses via juxtacrine intercellular signaling. However, pro-TNF-α can undergo a proteolytic cleavage at its Ala76-Val77 amide bond, which releases a soluble 17kDa extracellular domain (ectodomain) from the pro-TNF-α molecule. This soluble ectodomain is the cytokine commonly known as TNF-α, which is of pivotal importance in paracrine signaling. This proteolytic liberation of soluble TNF-α is catalyzed by ADAM17.
Recently, ADAM17 was discovered as a crucial mediator of resistance to radiotherapy. Radiotherapy can induce a dose-dependent increase of furin-mediated cleavage of the ADAM17 proform to active ADAM17, which results in enhanced ADAM17 activity in vitro and in vivo. It was also shown that radiotherapy activates ADAM17 in non-small cell lung cancer, which results in shedding of multiple survival factors, growth factor pathway activation, and radiotherapy-induced treatment resistance.
ADAM17 may play a prominent role in the Notch signaling pathway, during the proteolytic release of the Notch intracellular domain (from the Notch1 receptor) that occurs following ligand binding. ADAM17 also regulates the MAP kinase signaling pathway by regulating shedding of the EGFR ligand amphiregulin in the mammary gland. ADAM17 also has a role in the shedding of L-selectin, a cellular adhesion molecule. | 1 | Gene expression + Signal Transduction |
Middle and Late Minoan and Mycenaean vessels are many. First in size are some basins found at Tylissos in Crete, the largest measuring 1.40 metres in diameter. They are shallow hemispherical bowls with two or three loop-handles riveted on their edges, and are made in several sections. The largest is composed of seven hammered sheets, three at the lip, three in the body, and one at the base. This method of construction is usual in large complicated forms. The joints of necks and bodies of jugs and jars were often masked with a roll-moulding. Simpler and smaller forms were also cast. The finest specimens of such vases come from houses and tombs at Knossos. Their ornament is applied in separate bands, hammered or cast and chased, and soldered on the lip or shoulder of the vessel. A richly decorated form is a shallow bowl with wide ring-handle and flat lip, on both of which are foliate or floral patterns in relief.
A notable shape, connecting prehistoric with Hellenic metallurgy is a tripod-bowl, a hammered globular body with upright ring-handles on the lip and heavy cast legs attached to the shoulder. | 0 | Metallurgy |
Below 912 °C (1,674 °F), iron has a body-centered cubic (bcc) crystal structure and is known as α-iron or ferrite. It is thermodynamically stable and a fairly soft metal. α-Fe can be subjected to pressures up to ca. 15 GPa before transforming into a high-pressure form termed ε-Fe discussed below.
Magnetically, α-iron is paramagnetic at high temperatures. However, below its Curie temperature (T or A) of 771 °C (1044K or 1420 °F), it becomes ferromagnetic. In the past, the paramagnetic form of α-iron was known as beta iron (β-Fe). Even though the slight tetragonal distortion in the ferromagnetic state does constitute a true phase transition, the continuous nature of this transition results in only minor importance in steel heat treating. The A line forms the boundary between the beta iron and alpha fields in the phase diagram in Figure 1.
Similarly, the A boundary is of only minor importance compared to the A (eutectoid), A and A critical temperatures. The A, where austenite is in equilibrium with cementite + γ-Fe, is beyond the right edge in Fig. 1. The α + γ phase field is, technically, the β + γ field above the A. The beta designation maintains continuity of the Greek-letter progression of phases in iron and steel: α-Fe, β-Fe, austenite (γ-Fe), high-temperature δ-Fe, and high-pressure hexaferrum (ε-Fe).
The primary phase of low-carbon or mild steel and most cast irons at room temperature is ferromagnetic α-Fe. It has a hardness of approximately 80 Brinell. The maximum solubility of carbon is about 0.02 wt% at and 0.001% at . When it dissolves in iron, carbon atoms occupy interstitial "holes". Being about twice the diameter of the tetrahedral hole, the carbon introduces a strong local strain field.
Mild steel (carbon steel with up to about 0.2 wt% C) consists mostly of α-Fe and increasing amounts of cementite (FeC, an iron carbide). The mixture adopts a lamellar structure called pearlite. Since bainite and pearlite each contain α-Fe as a component, any iron-carbon alloy will contain some amount of α-Fe if it is allowed to reach equilibrium at room temperature. The amount of α-Fe depends on the cooling process. | 0 | Metallurgy |
Polyadenylation is the covalent linkage of a polyadenylyl moiety to a messenger RNA molecule. In eukaryotic organisms most messenger RNA (mRNA) molecules are polyadenylated at the 3' end, but recent studies have shown that short stretches of uridine (oligouridylation) are also common. The poly(A) tail and the protein bound to it aid in protecting mRNA from degradation by exonucleases. Polyadenylation is also important for transcription termination, export of the mRNA from the nucleus, and translation. mRNA can also be polyadenylated in prokaryotic organisms, where poly(A) tails act to facilitate, rather than impede, exonucleolytic degradation.
Polyadenylation occurs during and/or immediately after transcription of DNA into RNA. After transcription has been terminated, the mRNA chain is cleaved through the action of an endonuclease complex associated with RNA polymerase. After the mRNA has been cleaved, around 250 adenosine residues are added to the free 3' end at the cleavage site. This reaction is catalyzed by polyadenylate polymerase. Just as in alternative splicing, there can be more than one polyadenylation variant of an mRNA.
Polyadenylation site mutations also occur. The primary RNA transcript of a gene is cleaved at the poly-A addition site, and 100–200 As are added to the 3 end of the RNA. If this site is altered, an abnormally long and unstable mRNA construct will be formed. | 1 | Gene expression + Signal Transduction |
According to Frankel (1998) who performed a review on pitting corrosion, it develops in three successive steps: (or nucleation) by breakdown of the passive film protecting the metal surface from oxidation, (2) growth of metastable pits (growing up to the micron scale and then repassivating), and (3) the growth of larger and stable pits.
The evolution of the pit density (number of pits per surface area) as a function of time follows a sigmoid curve with the characteristic shape of a logistic function curve, or a hyperbolic tangent. Guo et al. (2018), after a statistical analysis of hundreds of individual pits observed on carbon steel surfaces at the nano-to-micro- scales, distinguish three stages of pitting corrosion: induction, propagation, and saturation. | 0 | Metallurgy |
The process was invented in Hanau, Germany in 1917. Heraeus Vacuumschmelze and Dr. Wilhelm Rohn applied for a patent on vacuum melting on 12 January 1918 and were granted a German patent DE 345161.
Edwin Fitch Northrup built the first prototype of a vacuum induction furnace in the United States of America in 1920.
Medium frequency furnaces were seen soon afterwards in England and Sweden in 1927.
The process was initially developed to refine certain special metals such as cobalt and nickel. As these metals and alloys became more common, the process of VIM became more widely used.
VIM now helps to melt a variety of metals for aircraft and nuclear applications. | 0 | Metallurgy |
Coil coating is the continuous and highly automated industrial process for efficiently coating metal coils. Because the metal is treated before it is cut and formed, the entire surface is cleaned and treated, providing tightly-bonded finishes. (Formed parts can have many holes, recessed areas, valleys, and hidden areas that make it difficult to clean and uniformly paint.) Coil-coated metal (often called prepainted metal) is often considered more durable and more corrosion-resistant than most post painted metal.
Annually, 4.5 million tons of coil-coated steel and aluminum are produced and shipped in North America, and 5 million tons in Europe. In almost every five-year period since the early 1980s, the growth rate of coil-coated metal has exceeded the growth rates of either steel and/or aluminum production. | 0 | Metallurgy |
When Bacillus subtilis is not under stress conditions, it is negatively regulated by the anti-sigma factor, Rsbw. RsbW is an anti-sigma factor that regulates another anti-sigma factor, sigma B. RsbW binds to sigma B and prevents it from forming an RNA polymerase holoenzyme. However, in stressed conditions, the unphosphorylated form of the protein, RsbV, competes with Sigma B for binding to RsbW. RsbV binds to RsbW, allowing sigma B to bind to the core RNA polymerase, resulting in the expression of stress response. | 1 | Gene expression + Signal Transduction |
Cleveland Potash Limited extracts and refines sylvinite ore from a deposit in North Yorkshire, England. Its processing plant uses froth flotation to produce a product rich in potassium chloride ("KCl"). After a test work campaign in which it compared the performance of the Cell with mechanical flotation cells in various duties in the flotation circuit, Cleveland Potash ordered a Cell with 6 downcomers for recovering potash slimes. The test work had shown a 4.8% increase in the recovery of potash slimes, equivalent at the time to an increase in revenue of approximately £518,000 per year. | 0 | Metallurgy |
Tissue fixation is performed by chemical fixation using formalin. This prevents the postmortem degeneration of the tissue and hardens soft tissue. The tissue is dehydrated using ethanol and the alcohol is cleared using an organic solvent such as xylene. The tissue is embedded in paraffin which infiltrates the microscopic spaces present throughout the tissue. The embedded tissue is sliced using a microtome and subsequently stained to produce contrast needed to visualize the tissue. | 1 | Gene expression + Signal Transduction |
Lead and LBE coolant are more corrosive to steel than sodium, and this puts an upper limit on the velocity of coolant flow through the reactor due to safety considerations. Furthermore, the higher melting points of lead and LBE (327 °C and 123.5 °C respectively) may mean that solidification of the coolant may be a greater problem when the reactor is operated at lower temperatures.
Finally, upon neutron radiation bismuth-209, the main isotope of bismuth present in LBE coolant, undergoes neutron capture and subsequent beta decay, forming polonium-210, a potent alpha emitter. The presence of radioactive polonium in the coolant would require special precautions to control alpha contamination during refueling of the reactor and handling components in contact with LBE. | 0 | Metallurgy |
In August 1997, the plant was included in the list of enterprises of strategic importance for the economy and security of Ukraine.
In 1998, for the first time, the plant was certified as a manufacturer of steel and semi-finished products from it (slabs and open-hearth ingots from carbon and carbon-manganese steel grades of normal and increased strength) according to the rules of the English Lloyd's Register.
In August 2002, on the basis of the blast-furnace and open-hearth shops of the Donetsk Metallurgical Plant, the Donetskstal Metallurgical Plant PJSC was established. The company specializes in the production of:
* foundry and pig iron
* more than 100 varieties of carbon, structural, low-alloyed, alloyed ordinary quality, high-quality and high-quality steel grades
* church bells made of non-ferrous high-quality alloy
* steel electric-welded longitudinal pipes and metal furniture frames
* slag-forming mixtures, granulated slag and building materials
Slabs made of normal strength marine structural steel grades GL-A and GL-B are certified according to the rules of Deutsche Lloyd.
In 2003, the church of St. Ignatius of Mariupol was built on the territory of the plant.
The plant completed 2013 with a net profit of UAH 83.322 million. | 0 | Metallurgy |
Mining is among the first steps of producing metal and as such is one of the foci of experimental archaeometallurgy. However, experimental research on mining is mostly limited to firesetting and the reproduction and use of mining tools. | 0 | Metallurgy |
*PPID Peptidyl-prolyl cis-trans isomerase D
*PPIE Peptidyl-prolyl cis-trans isomerase E
*PPIF Peptidyl-prolyl cis-trans isomerase F
*PPIG Peptidyl-prolyl cis-trans isomerase G
*PPIH Cyclophilin H
*CANX Calnexin. Folding of glycoproteins within endoplasmic reticulum
*CAPN1 Calpain subunit
*CAPN7
*CAPNS1 Calpain protease subunit
*NACA Nascent polypeptide associated complex alpha polypeptide
*NACA2
*PFDN2 Prefoldin 2
*PFDN4 Prefoldin 4
*PFDN5 Prefoldin 5
*PFDN6 Prefoldin 6
*SNX2 Sorting nexin 2
*SNX3 Sorting nexin 3
*SNX4 Sorting nexin 4
*SNX5 Sorting nexin 5
*SNX6 Sorting nexin 6
*SNX9 Sorting nexin 9
*SNX12 Sorting nexin 12
*SNX13 Sorting nexin 13
*SNX17 Sorting nexin 17
*SNX18 Sorting nexin 18
*SNX19 Sorting nexin 19
*SNX25 Sorting nexin 25
*SSR1 Translocon-associated protein TRAPA. Protein translocation in ER
*SSR2 Translocon-associated protein TRAPB. Protein translocation in ER
*SSR3 Translocon-associated protein TRAPG. Protein translocation in ER
*SUMO1 Protein targeting
*SUMO3 Protein targeting | 1 | Gene expression + Signal Transduction |
Problems with mRNA stability have been identified in viral genomes, cancer cells, and various diseases. Research shows that many of these problems arise because of faulty ARE function. Some of these problems have been listed below:
* The c-fos gene produces a transcription factor that is activated in several cancers, and it lacks the ARE elements.
* c-myc gene, also responsible for producing transcription factors found in several cancers, has also been reported to lack the ARE elements.
* The Cox-2 gene catalyses the production of prostaglandins—it overexpresses in several cancers, and is stabilized by the binding of CUGBP2 RNA-binding protein to ARE | 1 | Gene expression + Signal Transduction |
The Early Iron Age at Norşuntepe (1150–800 BC) is characterized by a shift away from Hittite material culture, possibly as a result of the influx of immigrants such as the Mushki. The settlement seems to have been restricted to the south terrace and may have had a rural character. During its final occupation phases (800–600 BC), Norşuntepe was part of Urartu. A building with a large, columned hall was located on the mail hill, whereas a second large building, possibly a caravanserai, was excavated on the south terrace. A cemetery located on the hill top included a burial chamber where three horses together with gear and weapons were buried.
The hilltop was again used as a cemetery during the Medieval Period. | 0 | Metallurgy |
Half-metallic ferromagnets exhibit a metallic behavior in one spin channel and an insulating behavior in the other spin channel. The first example of Heusler half-metallic ferromagnets was first investigated by de Groot et al., with the case of NiMnSb. Half-metallicity leads to the full polarization of the conducting electrons. Half metallic ferromagnets are therefore promising for spintronics applications. | 0 | Metallurgy |
By sequence similarity, most sigma factors are σ-like (). They have four main regions (domains) that are generally conserved:
N-terminus --------------------- C-terminus
The regions are further subdivided. For example, region 2 includes 1.2 and 2.1 through 2.4.
Domain 1.1 is found only in "primary sigma factors" (RpoD, RpoS in E.coli; "Group 1"). It is involved in ensuring the sigma factor will only bind the promoter when it is complexed with the RNA polymerase. Domains 2-4 each interact with specific promoter elements and with RNAP. Region 2.4 recognizes and binds to the promoter −10 element (called the "Pribnow box"). Region 4.2 recognizes and binds to the promoter −35 element.
Not every sigma factor of the σ family contains all the domains. Group 2, which includes RpoS, is very similar to Group 1 but lacks domain 1. Group 3 also lacks domain 1, and includes σ. Group 4, also known as the Extracytoplasmic Function (ECF) group, lack both σ1.1 and σ3. RpoE is a member.
Other known sigma factors are of the σ/RpoN () type. They are functional sigma factors, but they have significantly different primary amino acid sequences. | 1 | Gene expression + Signal Transduction |
The first potash application was in England in 1993, where Jameson Cells were used to treat potash slimes (see Potash flotation). It has subsequently been applied at Israel Chemicals Limited's Dead Sea Works and by an unnamed producer in the Saskatchewan province of Canada. | 0 | Metallurgy |
Microphthalmia-associated transcription factor also known as class E basic helix-loop-helix protein 32 or bHLHe32 is a protein that in humans is encoded by the MITF gene.
MITF is a basic helix-loop-helix leucine zipper transcription factor involved in lineage-specific pathway regulation of many types of cells including melanocytes, osteoclasts, and mast cells. The term "lineage-specific", since it relates to MITF, means genes or traits that are only found in a certain cell type. Therefore, MITF may be involved in the rewiring of signaling cascades that are specifically required for the survival and physiological function of their normal cell precursors.
MITF, together with transcription factor EB (TFEB), TFE3 and TFEC, belong to a subfamily of related bHLHZip proteins, termed the MiT-TFE family of transcription factors. The factors are able to form stable DNA-binding homo- and heterodimers. The gene that encodes for MITF resides at the mi locus in mice, and its protumorogenic targets include factors involved in cell death, DNA replication, repair, mitosis, microRNA production, membrane trafficking, mitochondrial metabolism, and much more. Mutation of this gene results in deafness, bone loss, small eyes, and poorly pigmented eyes and skin. In human subjects, because it is known that MITF controls the expression of various genes that are essential for normal melanin synthesis in melanocytes, mutations of MITF can lead to diseases such as melanoma, Waardenburg syndrome, and Tietz syndrome. Its function is conserved across vertebrates, including in fishes such as zebrafish and Xiphophorus.
An understanding of MITF is necessary to understand how certain lineage-specific cancers and other diseases progress. In addition, current and future research can lead to potential avenues to target this transcription factor mechanism for cancer prevention. | 1 | Gene expression + Signal Transduction |
Antisense oligonucleotides were discovered in 1978 by Paul Zamecnik and Mary Stephenson. Oligonucleotides, which are short nucleic acid fragments, bind to complementary target mRNA molecules when added to the cell. These molecules can be composed of single-stranded DNA or RNA and are generally 13–25 nucleotides long. The antisense oligonucleotides can affect gene expression in two ways: by using an RNase H-dependent mechanism or by using a steric blocking mechanism. RNase H-dependent oligonucleotides cause the target mRNA molecules to be degraded, while steric-blocker oligonucleotides prevent translation of the mRNA molecule. The majority of antisense drugs function through the RNase H-dependent mechanism, in which RNase H hydrolyzes the RNA strand of the DNA/RNA heteroduplex. expression. | 1 | Gene expression + Signal Transduction |
Signal transducer and activator of transcription 6 (STAT6) is a transcription factor that belongs to the Signal Transducer and Activator of Transcription (STAT) family of proteins. The proteins of STAT family transmit signals from a receptor complex to the nucleus and activate gene expression. Similarly as other STAT family proteins, STAT6 is also activated by growth factors and cytokines. STAT6 is mainly activated by cytokines interleukin-4 and interleukin-13. | 1 | Gene expression + Signal Transduction |
Senapathy proposed that the gene-expression regulatory sequences (promoter and poly-A addition site sequences) also could have originated from stop codons. A conserved sequence, AATAAA, exists in almost every gene a short distance downstream from the end of the protein-coding message and serves as a signal for the addition of poly(A) in the mRNA copy of the gene. This poly(A) sequence signal contains a stop codon, TAA. A sequence shortly downstream from this signal, thought to be part of the complete poly(A) signal, also contains the TAG and TGA stop codons.
Eukaryotic RNA-polymerase-II-dependent promoters can contain a TATA box (consensus sequence TATAAA), which contains the stop codon TAA. Bacterial promoter elements at ~10 bases exhibits a TATA box with a consensus of TATAAT (which contains the stop codon TAA), and at -35 bases exhibits a consensus of TTGACA (containing the stop codon TGA). Thus, the evolution of the whole RNA processing mechanism seems to have been influenced by the too-frequent occurrence of stop codons, thus making the stop codons the focal points for RNA processing. | 1 | Gene expression + Signal Transduction |
Prodynorphin, also known as proenkephalin B, is an opioid polypeptide hormone involved with chemical signal transduction and cell communication. The gene for prodynorphin is expressed in the endometrium and the striatum, and its gene map locus is 20pter-p12. Prodynorphin is a basic building-block of endorphins, the chemical messengers in the brain that appear most heavily involved in the anticipation and experience of pain and the formation of deep emotional bonds, and that are also critical in learning and memory.
The gene is thought to influence perception, as well as susceptibility to drug dependence, and is expressed more readily in human beings than in other primates. | 1 | Gene expression + Signal Transduction |
In the year 1995, it was reported that the costs of corrosion nationwide in the USA were nearly $300 billion per year. This confirmed earlier reports of damage to the world economy caused by corrosion.
Zaki Ahmad, in his book Principles of corrosion engineering and corrosion control,
states that "Corrosion engineering is the application of the principles evolved from corrosion science to minimize or prevent corrosion". Shreir et al. suggest likewise in their large, two volume work entitled Corrosion. Corrosion engineering involves designing of corrosion prevention schemes and implementation of specific codes and practices. Corrosion prevention measures, including Cathodic protection, designing to prevent corrosion and coating of structures fall within the regime of corrosion engineering. However, corrosion science and engineering go hand-in-hand and they cannot be separated: it is a permanent marriage to produce new and better methods of protection from time to time. This may include the use of Corrosion inhibitors. In the Handbook of corrosion engineering, the author Pierre R. Roberge states "Corrosion is the destructive attack of a material by reaction with its environment. The serious consequences of the corrosion process have become a problem of worldwide significance."
Costs are not only monetary. There is a financial cost and also a waste of natural resources. In 1988 it was estimated that one tonne of metal was converted completely to rust every ninety seconds in the United Kingdom. There is also the cost of human lives. Failure whether catastrophic or otherwise due to corrosion has cost human lives. | 0 | Metallurgy |
When it is time for a cell to enter S phase, complexes of cyclin-dependent kinases (CDK) and cyclins phosphorylate pRb, allowing E2F-DP to dissociate from pRb and become active. When E2F is free it activates factors like cyclins (e.g. cyclin E and cyclin A), which push the cell through the cell cycle by activating cyclin-dependent kinases, and a molecule called proliferating cell nuclear antigen, or PCNA, which speeds DNA replication and repair by helping to attach polymerase to DNA. | 1 | Gene expression + Signal Transduction |
The process of creating these luxuriously inlaid objects is somewhat complicated and has multiple stages. First, designs are formed on the surface of the metal (usually copper or brass) by relief, piercing, engraving, or chasing. Color is then added to the crevices of the surface by encrustation, overlay or, most commonly, inlay of precious metals. These metal inlays could be sheets or wires hammered into place. The area around the inlaid design was often roughened or covered with some sort of black material. Each craftsman in the industry had their own personal specialization. This specialization could be in a particular metal, technique, object, or step in the process. There are two reasons the casting step of the process usually took place in an urban workshop. The first is simply because most patrons were located in these urban areas. The second is because it would be too difficult to move all of the heavy equipment necessary for casting from one rural location to the next. Inlayers and precious metalworkers were able to travel with ease and were not confined to the workshops as casters were. There were three main inlay innovations that are believed to have originated in Mosul in the thirteenth century- gold inlays, black inlay, and background scrolls inlaid with silver.
The designs themselves are quite varied in subject matter. Some of the popular motifs include: astrology, hunting, enthronements, battles, court life, and genre scenes. Genre scenes, images of everyday life are particularly prominent. Among the original design traditions there is evidence that can trace them to East Asia through the designs within textiles. Mosul was a great textile industry during the same period that they were producing these inlaid objects and they happened to specialize in reproductions of Chinese silks. It is speculated that many of the traditional metalwork designs were heavily influenced or even direct copies of these silk reproductions.
Historically, many scholars have argued that the Mongol sack of Mosul led to the demise of the luxury metalworking industry, however modern scholarship and an abundance of evidence disproves this. For example, it is known that Mosul metalworkers received an imperial commission by Il-Khan Abu Sa'id in the last years of the Ilkanate. Not only did Mosul continue to produce elaborate inlaid objects after the Mongol sack, they also altered their traditional stylistic choices to coalesce with Mongol taste. There was a new emphasis on minuscule style, the figures represented reflect the Ilkanhid fashion of the period, and they started to put more emphasis on pattern over figuration.
One of the finest examples of the Mosul school of metalworking is the Blacas Ewer.
Another item tentatively attributed to Mosul is the Courtauld bag, which is thought to be the world's oldest surviving handbag. | 0 | Metallurgy |
All family members are capable of catalyzing the hydrolysis of PIP, a phosphatidylinositol at the inner leaflet of the plasma membrane into the two second messengers, inositol trisphosphate (IP) and diacylglycerol (DAG).
The chemical reaction may be expressed as:
:1-phosphatidyl-1-myo-inositol 4,5-bisphosphate + HO -myo-inositol 1,4,5-trisphosphate + diacylglycerol
PLCs catalyze the reaction in two sequential steps. The first reaction is a phosphotransferase step that involves an intramolecular attack between the hydroxyl group at the 2 position on the inositol ring and the adjacent phosphate group resulting in a cyclic IP intermediate. At this point, DAG is generated. However, in the second phosphodiesterase step, the cyclic intermediate is held within the active site long enough to be attacked by a molecule of water, resulting in a final acyclic IP product. It should be mentioned that bacterial forms of the enzyme, which contain only the catalytic lipase domain, produce cyclic intermediates exclusively, whereas the mammalian isoforms generate predominantly the acyclic product. However, it is possible to alter experimental conditions (e.g., temperature, pH) in vitro' such that some mammalian isoforms will alter the degree to which they produce mixtures of cyclic/acyclic products along with DAG. This catalytic process is tightly regulated by reversible phosphorylation of different phosphoinositides and their affinity for different regulatory proteins. | 1 | Gene expression + Signal Transduction |
The ores used in ancient smelting processes were rarely pure metal compounds. Impurities were removed from the ore through the process of slagging, which involves adding heat and chemicals. Slag is the material in which the impurities from ores (known as gangue), as well as furnace lining and charcoal ash, collect. The study of slag can reveal information about the smelting process used at the time of its formation.
The finding of slag is direct evidence of smelting having occurred in that place as slag was not removed from the smelting site. Through slag analysis, archaeologists can reconstruct ancient human activities concerned with metal work such as its organization and specialization.
The contemporary knowledge of slagging gives insights into ancient iron production. In a smelting furnace, up to four different phases might co-exist. From the top of the furnace to the bottom, the phases are slag, matte, speiss, and liquid metal.
Slag can be classified as furnace slag, tapping slag or crucible slag depending on the mechanism of production. The slag has three functions. The first is to protect the melt from contamination. The second is to accept unwanted liquid and solid impurities. Finally, slag can help to control the supply of refining media to the melt.
These functions are achieved if the slag has a low melting temperature, low density and high viscosity which ensure a liquid slag that separates well from the melting metal. Slag should also maintain its correct composition so that it can collect more impurities and be immiscible in the melt.
Through chemical and mineralogical analysis of slag, factors such as the identity of the smelted metal, the types of ore used and technical parameters such as working temperature, gas atmosphere and slag viscosity can be learned. | 0 | Metallurgy |
Rasaratna Samuccaya ( Devanagari: रसरत्न समुच्चय) is an Indian Sanskrit treatise on alchemy. The text is dated between 13th to 16th century CE.
The text contains detailed descriptions of various complex metallurgical processes, as well as descriptions of how to set up and equip a laboratory and other topics concerning Indian alchemy. It is a work that synthesises the writings and opinions of several earlier authors and presents a coherent account of medieval Indian alchemy. | 0 | Metallurgy |
ASF/SF2, in the presence of elF4E, promotes the initiation of translation of ribosome-bound mRNA by suppressing the activity of 4E-BP and recruiting molecules for further regulation of translation. ASF/SF2 interacts with the nuclear export protein TAP in a regulated manner, controlling the export of mature mRNA from the nucleus. An increase in cellular ASF/SF2 also will increase the efficiency of nonsense-mediated mRNA decay (NMD), favoring NMD that occurs before mRNA release from the nucleus over NMD that occurs after mRNA export from the nucleus to the cytoplasm. This shift in NMD caused by increased ASF/SF2 is accompanied by overall enhancement of the pioneer round of translation, through elF4E-bound mRNA translation and subsequent translationally active ribosomes, increased association of pioneer translation initiation complexes with ASF/SF2, and increased levels of active TAP. | 1 | Gene expression + Signal Transduction |
Cast gold knucklebones, beads, and bracelets, found in graves at Bulgaria's Varna Necropolis, have been dated to approximately 6500 years BP. They are believed to be both some of the oldest known manufactured golden objects, and the oldest objects known to have been made using lost wax casting. | 0 | Metallurgy |
Ribosomal pause refers to the queueing or stacking of ribosomes during translation of the nucleotide sequence of mRNA transcripts. These transcripts are decoded and converted into an amino acid sequence during protein synthesis by ribosomes. Due to the pause sites of some mRNA's, there is a disturbance caused in translation. Ribosomal pausing occurs in both eukaryotes and prokaryotes. A more severe pause is known as a ribosomal stall.
Its been known since the 1980s that different mRNAs are translated at different rates. The main reason for these differences was thought to be the concentration of varieties of rare tRNAs limiting the rate at which some transcripts could be decoded. However, with research techniques such as ribosome profiling, it was found that at certain sites there were higher concentrations of ribosomes than average, and these pause sites were tested with specific codons. No link was found between the occupancy of specific codons and amount of their tRNAs. Thus, the early findings about rare tRNAs causing pause sites doesnt seem plausible.
Two techniques can localize the ribosomal pause site in vivo; a micrococcal nuclease protection assay and isolation of polysomal transcript. Isolation of polysomal transcripts occurs by centrifuging tissue extracts through a sucrose cushion with translation elongation inhibitors, for example cycloheximide.
Ribosome pausing can be detected during preprolactin synthesis on free polysomes, when the ribosome is paused the other ribosomes are tightly stacked together. When the ribosome pauses, during translation, the fragments that started to translate before the pause took place are overrepresented. However, along with the mRNA if the ribosome pauses then specific bands will be improved in the trailing edge of the ribosome.
Some of the elongation inhibitors, such as: cycloheximide (in eukaryotes) or chloramphenicol, cause the ribosomes to pause and to accumulate in the start codons. Elongation Factor P regulates the ribosomal pause at polyproline in bacteria, and when there is no EFP the density of ribosomes decreases from the polyproline motifs. If there are multiple ribosome pauses, then the EFP won't resolve it. | 1 | Gene expression + Signal Transduction |
Plasma spraying systems can be categorized by several criteria.
Plasma jet generation:
*direct current (DC plasma), where the energy is transferred to the plasma jet by a direct current, high-power electric arc
*induction plasma or RF plasma, where the energy is transferred by induction from a coil around the plasma jet, through which a radio-frequency current passes. This electrode-free technology allows to produce coatings with high purity and high density.
Plasma-forming medium:
*gas-stabilized plasma (GSP), where the plasma forms from a gas; typically argon, hydrogen, helium or their mixtures
*water-stabilized plasma (WSP), where plasma forms from water (through evaporation, dissociation and ionization) or other suitable liquid
*hybrid plasma – with combined gas and liquid stabilization, typically argon and water
Spraying environment:
*atmospheric plasma spraying (APS), performed in ambient air
*controlled atmosphere plasma spraying (CAPS), usually performed in a closed chamber, either filled with inert gas or evacuated
*variations of CAPS: high-pressure plasma spraying (HPPS), low-pressure plasma spraying (LPPS), the extreme case of which is vacuum plasma spraying (VPS, see below)
*underwater plasma spraying
Another variation consists of having a liquid feedstock instead of a solid powder for melting, this technique is known as Solution precursor plasma spray | 0 | Metallurgy |
Uranium rhodium germanium (URhGe) is the first discovered metal that becomes superconducting in the presence of an extremely strong electromagnetic field. Very unlike other superconducting materials, whose superconducting properties can be lost due to strong magnetic fields, uranium rhodium germanium actually regains superconducting abilities at about 8 teslas. | 0 | Metallurgy |
Recrystallization is defined as the process in which grains of a crystal structure come in a new structure or new crystal shape.
A precise definition of recrystallization is difficult to state as the process is strongly related to several other processes, most notably recovery and grain growth. In some cases it is difficult to precisely define the point at which one process begins and another ends. Doherty et al. defined recrystallization as:
Thus the process can be differentiated from recovery (where high angle grain boundaries do not migrate) and grain growth (where the driving force is only due to the reduction in boundary area).
Recrystallization may occur during or after deformation (during cooling or subsequent heat treatment, for example). The former is termed dynamic while the latter is termed static. In addition, recrystallization may occur in a discontinuous manner, where distinct new grains form and grow, or a continuous manner, where the microstructure gradually evolves into a recrystallized microstructure. The different mechanisms by which recrystallization and recovery occur are complex and in many cases remain controversial. The following description is primarily applicable to static discontinuous recrystallization, which is the most classical variety and probably the most understood. Additional mechanisms include (geometric) dynamic recrystallization and strain induced boundary migration.
Secondary recrystallization occurs when a certain very small number of {110}<001> (Goss) grains grow selectively, about one in 106 primary grains, at the expense of many other primary recrystallized grains. This results in abnormal grain growth, which may be beneficial or detrimental for product material properties. The mechanism of secondary recrystallization is a small and uniform primary grain size, achieved through the inhibition of normal grain growth by fine precipitates called inhibitors. Goss grains are named in honor of Norman P. Goss, the inventor of grain-oriented electrical steel circa 1934. | 0 | Metallurgy |
Eshelby was clear and amusing as a lecturer, and prepared his lectures with great care, but was not keen on doing experimental work. He was well versed in Sanskrit (among other classical languages) and was an avid second-hand book buyer.
Eshelby died on 10 December 1981. | 0 | Metallurgy |
An example of aluminum alloys where solid solution strengthening happens by adding magnesium and manganese into the aluminum matrix. Commercially Mn can be added to the AA3xxx series and Mg can be added to the AA5xxx series. Mn addition to the Aluminum alloys assists in the recrystallization and recovery of the alloy which influences the grain size as well. Both of these systems are used in low to medium-strength applications, with appreciable formability and corrosion resistance. | 0 | Metallurgy |
PABPII, or polyadenine binding protein II, is a protein involved in the assembly of the polyadenine tail added to newly synthesized pre-messenger RNA (mRNA) molecules during the process of gene transcription. It is a regulatory protein that controls the rate at which polyadenine polymerase (PAP) adds adenine nucleotides to the 3' end of the growing tail within the nucleus of the cell. In the absence of PABPII, PAP adds adenines slowly, typically about 12. PABPII then binds to the short polyadenine tail and induces an acceleration in the rate of addition by PAP until the tail has grown to about 200 adenines long. The mechanism by which PABPII signals the termination of the polymerization reaction once the tail has reached its required length is not clearly understood.
PABPII is distinct from the related protein PABPI in being localized to the cell nucleus rather than the cytoplasm. | 1 | Gene expression + Signal Transduction |
The Jameson Cell can be used for the reverse flotation of silica from iron ore, where flotation columns have traditionally been used. | 0 | Metallurgy |
Introns may be lost or gained over evolutionary time, as shown by many comparative studies of orthologous genes. Subsequent analyses have identified thousands of examples of intron loss and gain events, and it has been proposed that the emergence of eukaryotes, or the initial stages of eukaryotic evolution, involved an intron invasion. Two definitive mechanisms of intron loss, reverse transcriptase-mediated intron loss (RTMIL) and genomic deletions, have been identified, and are known to occur. The definitive mechanisms of intron gain, however, remain elusive and controversial. At least seven mechanisms of intron gain have been reported thus far: intron transposition, transposon insertion, tandem genomic duplication, intron transfer, intron gain during double-strand break repair (DSBR), insertion of a group II intron, and intronization. In theory it should be easiest to deduce the origin of recently gained introns due to the lack of host-induced mutations, yet even introns gained recently did not arise from any of the aforementioned mechanisms. These findings thus raise the question of whether or not the proposed mechanisms of intron gain fail to describe the mechanistic origin of many novel introns because they are not accurate mechanisms of intron gain, or if there are other, yet to be discovered, processes generating novel introns.
In intron transposition, the most commonly purported intron gain mechanism, a spliced intron is thought to reverse splice into either its own mRNA or another mRNA at a previously intron-less position. This intron-containing mRNA is then reverse transcribed and the resulting intron-containing cDNA may then cause intron gain via complete or partial recombination with its original genomic locus. Transposon insertions can also result in intron creation. Such an insertion could intronize the transposon without disrupting the coding sequence when a transposon inserts into the sequence AGGT, resulting in the duplication of this sequence on each side of the transposon. It is not yet understood why these elements are spliced, whether by chance, or by some preferential action by the transposon. In tandem genomic duplication, due to the similarity between consensus donor and acceptor splice sites, which both closely resemble AGGT, the tandem genomic duplication of an exonic segment harboring an AGGT sequence generates two potential splice sites. When recognized by the spliceosome, the sequence between the original and duplicated AGGT will be spliced, resulting in the creation of an intron without alteration of the coding sequence of the gene. Double-stranded break repair via non-homologous end joining was recently identified as a source of intron gain when researchers identified short direct repeats flanking 43% of gained introns in Daphnia. These numbers must be compared to the number of conserved introns flanked by repeats in other organisms, though, for statistical relevance. For group II intron insertion, the retrohoming of a group II intron into a nuclear gene was proposed to cause recent spliceosomal intron gain.
Intron transfer has been hypothesized to result in intron gain when a paralog or pseudogene gains an intron and then transfers this intron via recombination to an intron-absent location in its sister paralog. Intronization is the process by which mutations create novel introns from formerly exonic sequence. Thus, unlike other proposed mechanisms of intron gain, this mechanism does not require the insertion or generation of DNA to create a novel intron.
The only hypothesized mechanism of recent intron gain lacking any direct evidence is that of group II intron insertion, which when demonstrated in vivo, abolishes gene expression. Group II introns are therefore likely the presumed ancestors of spliceosomal introns, acting as site-specific retroelements, and are no longer responsible for intron gain. Tandem genomic duplication is the only proposed mechanism with supporting in vivo experimental evidence: a short intragenic tandem duplication can insert a novel intron into a protein-coding gene, leaving the corresponding peptide sequence unchanged. This mechanism also has extensive indirect evidence lending support to the idea that tandem genomic duplication is a prevalent mechanism for intron gain. The testing of other proposed mechanisms in vivo, particularly intron gain during DSBR, intron transfer, and intronization, is possible, although these mechanisms must be demonstrated in vivo to solidify them as actual mechanisms of intron gain. Further genomic analyses, especially when executed at the population level, may then quantify the relative contribution of each mechanism, possibly identifying species-specific biases that may shed light on varied rates of intron gain amongst different species. | 1 | Gene expression + Signal Transduction |
This book is a description of the various types of veins that can be found. There are 30 illustrations of different forms of these veins, forming the majority of Book III. Agricola also describes a compass to determine the direction of veins and mentions that some writers claim that veins lying in certain directions are richer, although he provides counter-examples. He also mentions the theory that the sun draws the metals in veins to the surface, although he himself doubts this. Finally he explains that gold is not generated in the beds of streams and rivers and east-west streams are not more productive than others inherently. Gold occurs in streams because it is torn from veins by the water. | 0 | Metallurgy |
Many metals have several different crystal structures at the same composition, but most metals do not show this shape-memory effect. The special property that allows shape-memory alloys to revert to their original shape after heating is that their crystal transformation is fully reversible. In most crystal transformations, the atoms in the structure will travel through the metal by diffusion, changing the composition locally, even though the metal as a whole is made of the same atoms. A reversible transformation does not involve this diffusion of atoms, instead all the atoms shift at the same time to form a new structure, much in the way a parallelogram can be made out of a square by pushing on two opposing sides. At different temperatures, different structures are preferred and when the structure is cooled through the transition temperature, the martensitic structure forms from the austenitic phase. | 0 | Metallurgy |
A subgrain is a part of the grain that is only slightly disoriented from other parts of the grain. Current research is being done to see the effect of subgrain strengthening in materials. Depending on the processing of the material, subgrains can form within the grains of the material. For example, when Fe-based material is ball-milled for long periods of time (e.g. 100+ hours), subgrains of 60–90 nm are formed. It has been shown that the higher the density of the subgrains, the higher the yield stress of the material due to the increased subgrain boundary. The strength of the metal was found to vary reciprocally with the size of the subgrain, which is analogous to the Hall–Petch equation. The subgrain boundary strengthening also has a breakdown point of around a subgrain size of 0.1 µm, which is the size where any subgrains smaller than that size would decrease yield strength. | 0 | Metallurgy |
Firesetting is the process of exposing a rock face to high temperatures to induce cracking, spalling, and an overall increase to the brittleness of the rock in order to make it more susceptible to mining processes. Understanding the process of firesetting has been a crucial element to the development of an archaeological history of mining and as such has been the subject of several experiments to reproduce the technique. Typically firesetting experiments are conducted by setting a fire next to a predetermined rock face while taking measurements on the amount of and type of fuel used, temperatures of the fire and rock face, the amount of spalling before and after excavation, as well as the amount of time required for the different procedures. This examination allows for several possible inferences to be made about the mining process including the total amount of fuel a mining site may have needed to complete and its effects on the surrounding environment as well as how mining labor could have been organized. One outcome of firesetting experimentation is the realization that the quenching, or dousing the rock face with water after heating, is not necessary to making the rock face easier to excavate. The quenching process had been a standard step in most experiments with firesetting, but now more research is necessary to answer the new question of why quenching was used if it was not effective. | 0 | Metallurgy |
Pelletizing is the process of compressing or molding a material into the shape of a pellet. A wide range of different materials are pelletized including chemicals, iron ore, animal compound feed, plastics, waste materials, and more. The process is considered an excellent option for the storage and transport of said materials. The technology is widely used in the powder metallurgy engineering and medicine industries. | 0 | Metallurgy |
The term "inclusion" is also used in the context of metallurgy and metals processing. During the melt stage of processing particles such as oxides can enter or form in the liquid metal which are subsequently trapped when the melt solidifies. The term is usually used negatively such as when the particle could act as a fatigue crack nucleator or as an area of high stress intensity. | 0 | Metallurgy |
In flash smelting, the concentrate is dispersed in an air or oxygen stream and the smelting reactions are largely completed while the mineral particles are still in flight. The reacted particles then settle in a bath at the bottom of the furnace, where they behave like calcine in a reverberatory furnace. A slag layer forms on top of the matte layer, and they can separately be tapped from the furnace. | 0 | Metallurgy |
After the DNA-gelatin mixture preparation, the mixture is pipetted onto a slide surface and the slide is placed in a covered petri dish. A desiccant is added to the dish to dry up the solution. Finally, cultured cells are poured into the dish for plasmid uptake. However, with the invention of different types of microarray printing systems, hundreds of transfection mixes (containing different DNA of interest) may be printed on the same slide for cell uptake of plasmids. There are two major types of microarray printing systems manufactured by different companies: contact and non-contact printing systems.
An example of a non-contact printing system is the Piezorray Flexible Non-contact Microarraying System. It uses pressure control and a piezoelectric collar to squeeze out consistent drops of approximately 333 pL in volume. The PiezoTip dispensers do not contact the surface to which the sample is dispensed; thus, contamination potential is reduced and the risk of disrupting the target surface is eliminated. An example of a contact printing system is the SpotArray 72 (Perkin Elmer Life Sciences) contact-spotting system. Its printhead can accommodate up to 48 pins, and creates compact arrays by selectively raising and lowering subsets of pins during printing. After printing, the pins are washed with a powerful pressure-jet pin washer and vacuum-dried, eliminating carryover. Another example of a contact printing system is the Qarray system (Genetix). It has three types of printing systems: QArray Mini, QArray 2 and QArray Max. After printing, the solution is allowed to dry up and the DNA-gelatin is stuck tightly in position on the array. | 1 | Gene expression + Signal Transduction |
Rust can be avoided by controlling the moisture in the atmosphere. An example of this is the use of silica gel packets to control humidity in equipment shipped by sea. | 0 | Metallurgy |
Shrinkage after solidification can be dealt with by using an oversized pattern designed specifically for the alloy used. s, or s, are used to make the patterns oversized to compensate for this type of shrinkage. These rulers are up to 2.5% oversize, depending on the material being cast. These rulers are mainly referred to by their percentage change. A pattern made to match an existing part would be made as follows: First, the existing part would be measured using a standard ruler, then when constructing the pattern, the pattern maker would use a contraction rule, ensuring that the casting would contract to the correct size.
Note that patternmaker's shrinkage does not take phase change transformations into account. For example, eutectic reactions, martensitic reactions, and graphitization can cause expansions or contractions. | 0 | Metallurgy |
Ferrosilicon is produced by reduction of silica or sand with coke in the presence of iron. Typical sources of iron are scrap iron or millscale. Ferrosilicons with silicon content up to about 15% are made in blast furnaces lined with acid fire bricks.
Ferrosilicons with higher silicon content are made in electric arc furnaces. The usual formulations on the market are ferrosilicons with 15%, 45%, 75%, and 90% silicon. The remainder is iron, with about 2% consisting of other elements like aluminium and calcium. An overabundance of silica is used to prevent formation of silicon carbide. Microsilica is a useful byproduct.
A mineral perryite is similar to ferrosilicon, with its composition FeSi. In contact with water, ferrosilicon may slowly produce hydrogen. The reaction, which is accelerated in the presence of base, is used for hydrogen production. The melting point and density of ferrosilicon depends on its silicon content, with two nearly-eutectic areas, one near FeSi and second spanning FeSi-FeSi composition range. | 0 | Metallurgy |
Near the end of mitosis, p130 and p107 are dephosphorylated from their hyperphosphorylated state by the phosphatase PP2a. Inhibition of PP2a activity reduced promoter binding of some of the proteins of the DREAM complex in the subsequent G1 phase and de-repression of gene expression.
Other components have been shown to be phosphorylated for DREAM complex assembly to occur. Of these, LIN52 phosphorylation on its S28 residue is the most well-understood. Substitution of this serine to alanine led to reduced binding of the MuvB core to p130 and impaired the ability of cells to enter quiescence. This indicates that LIN52 S28 phosphorylation is required for proper association and function of the DREAM complex via binding with p130.
One known regulator of phosphorylation of the S28 residue is the DYRK1A. The loss of this kinase leads to decreased phosphorylation of the S28 residue and association of p130 with MuvB. DYRK1A was also found to degrade cyclin D1, which would increase p21 levels – both of which contribute to cell cycle exit.
The DREAM complex was also shown to regulate cytokinesis through GAS2L3. | 1 | Gene expression + Signal Transduction |
Different types of corrosion inhibitor exist. Among them, oxidizing species such as chromate () and nitrite () were the first used to re-establish the state of passivation in the protective oxide layer. In the specific case of steel, the cation being a relatively soluble species, it contributes to favor the dissolution of the oxide layer which so loses its passivity. To restore the passivity, the principle simply consists to prevent the dissolution of the oxide layer by converting the soluble divalent cation into the much less soluble trivalent cation. This approach is also at the basis of the chromate conversion coating used to passivate steel, aluminium, zinc, cadmium, copper, silver, titanium, magnesium, and tin alloys.
As hexavalent chromate is a known carcinogen, its aqueous effluents can no longer be freely discharged into the environment and its maximum concentration acceptable in water is very low.
Nitrite is also an oxidizing species and has been used as corrosion inhibitor since the 1950's.
Under the basic conditions prevailing in concrete pore water nitrite converts the relatively soluble ions into the much less soluble ions, and so protects the carbon-steel reinforcement bars by forming a new and denser layer of γ- as follows:
Corrosion inhibitors, when present in sufficient amount, can provide protection against pitting. However, too low level of them can aggravate pitting by forming local anodes. | 0 | Metallurgy |
Frzb (pronounced like the toy frisbee) is a Wnt-binding protein especially important in embryonic development. It is a competitor for the cell-surface G-protein receptor Frizzled.
Frizzled is a tissue polarity gene in Drosophila melanogaster and encodes integral proteins that function as cell-surface receptors for Wnts called serpentine receptors. The integral membrane proteins contain a cysteine-rich domain thought to be the Wnt binding domain in extracellular region. The signals are initiated at the 7 transmembrane domain and transmitted through receptor coupling to G-proteins.
This protein is expressed in chondrocytes making it important in skeletal development in the embryo and fetus. Frzb is localized in the extracellular plasma membrane. Unlike frizzled, frzb lacks the 7 transmembrane domains normally found in G-protein-coupled receptors. It is still considered a homolog of frizzled because it contains a Cysteine Rich Domain (CRD), and because of its intracellular C-terminus which is crucial for signaling. The CRD is highly conserved in diverse proteins, such as receptor tyrosine kinases and functions as a ligand binding domain. The C-terminal is a carboxyl terminus located intracellularly and is required for canonical signaling.
The serpentine receptors (frzb) couple binds to ligand (Wnt protein) and activates G-proteins. A signal transduction cascade results in the secretion of first and second group antagonists. First group antagonists are composed of secreted Frizzled Related protein family (Sfrp) and Wnt inhibitory factor (Wif). Both Srfp and Wif bind directly to Wnt proteins blocking activation of the receptor. Second group of antagonists contains a class of Wnt inhibitory proteins known as Frizzled Receptor-like Proteins (FRPs). FRPs bind to the LRP (low-density-lipoprotein-related protein) co-receptors blocking activation of the Wnt signaling pathway.
One such pathway that involves Frizzled (Fz) family is the Wnt/β-Catenin (β-Cat) signaling. β-Cat is an intracellular signal that is held in check by axin. In this pathway, the activation of Wnt receptors can be transduced by the canonical pathway via a series of phosphorylation steps leading to stabilization and nuclear import of β-Cat into the nucleus where β-Cat associates with T-cell factor (TCF), a DNA-binding protein family. The β-Cat and TCF complex activates target genes of the Wnt pathway. In the absence of Wnt, β-Catenin is phosphorylated by complex containing GSK3 (glycogen synthase kinase 3) which targets β-Cat for proteosomal degradation. In the nucleus, members of the T-cell factor (TCF) family of DNA-binding proteins repress Wnt targets along with co-repressors such as Groucho (Gro).
If Wnt is present it binds to Fz-LRP receptors causing axin to bind to intracellular domain of LRP and Fz. Dishevelled (Dvl) is a protein required for Wnt-dependent inhibition complex. The combination of LRP-axin induces Dvl phosphorylation (P) which blocks the APC-axin-GSK3 complex from phosphorylating β-Cat. The accumulated β-Cat then enters the nucleus and converts TCF into a transcriptional activator.
Defects in Frzb are associated with female-specific osteoarthritis (OA) susceptibility which is the most prevalent form of arthritis and common cause of disability.
https://web.archive.org/web/20070930043451/http://jcs.biologists.org/content/vol119/issue3/images/large/JCS02826F1.jpeg
Frzb (known as Frzb1 or Sfrp3, Secreted Frizzled Related Protein 3) was initially identified as a chondrogenic factor during bone morphogenesis, and was described as a novel marker of the neural crest-derived mesenchymal cells that contribute to dental follicle formation, the future periodontium. | 1 | Gene expression + Signal Transduction |
The matte, which is produced in the smelter, contains 30–70% copper (depending on the process used and the operating philosophy of the smelter), primarily as copper sulfide, as well as iron sulfide. The sulfur is removed at a high temperature as sulfur dioxide by blowing air through molten matte:
:2 CuS + 3 O → 2 CuO + 2 SO
:CuS + O → Cu + SO
In a parallel reaction the iron sulfide is converted to slag:
:2 FeS + 3 O → 2 FeO + 2 SO
:2 FeO + SiO → FeSiO
The purity of this product is 98%, it is known as blister because of the broken surface created by the escape of sulfur dioxide gas as blister copper pigs or ingots are cooled. By-products generated in the process are sulfur dioxide and slag. The sulfur dioxide is captured and converted to sulfuric acid and either sold on the open market or used in copper leaching processes. | 0 | Metallurgy |
There are a number of problems that can be encountered during the casting process. The main types are: gas porosity, shrinkage defects, mold material defects, pouring metal defects, and metallurgical defects. | 0 | Metallurgy |
They were the first set of nonsense mutations to be discovered, isolated by Richard H. Epstein and Charles Steinberg and named after their friend and graduate Caltech student Harris Bernstein, whose last name means "amber" in German (cf. Bernstein).
Viruses with amber mutations are characterized by their ability to infect only certain strains of bacteria, known as amber suppressors. These bacteria carry their own mutation that allows a recovery of function in the mutant viruses. For example, a mutation in the tRNA that recognizes the amber stop codon allows translation to "read through" the codon and produce a full-length protein, thereby recovering the normal form of the protein and "suppressing" the amber mutation.
Thus, amber mutants are an entire class of virus mutants that can grow in bacteria that contain amber suppressor mutations. Similar suppressors are known for ochre and opal stop codons as well.
tRNA molecules carrying unnatural aminoacids have been designed to recognize the amber stop codon in bacterial RNA. This technology allows for incorporation of orthogonal aminoacids (such as p-azidophenylalanine) at specific locations of the target protein. | 1 | Gene expression + Signal Transduction |
The minor spliceosome is a ribonucleoprotein complex that catalyses the removal (splicing) of an atypical class of spliceosomal introns (U12-type) from messenger RNAs in some clades of eukaryotes. This process is called noncanonical splicing, as opposed to U2-dependent canonical splicing. U12-type introns represent less than 1% of all introns in human cells. However they are found in genes performing essential cellular functions. | 1 | Gene expression + Signal Transduction |
Semi-solid metal (SSM) casting is a modified die casting process that reduces or eliminates the residual porosity present in most die castings. Rather than using liquid metal as the feed material, SSM casting uses a higher viscosity feed material that is partially solid and partially liquid. A modified die casting machine is used to inject the semi-solid slurry into reusable hardened steel dies. The high viscosity of the semi-solid metal, along with the use of controlled die filling conditions, ensures that the semi-solid metal fills the die in a non-turbulent manner so that harmful porosity can be essentially eliminated.
Used commercially mainly for aluminium and magnesium alloys, SSM castings can be heat treated to the T4, T5 or T6 tempers. The combination of heat treatment, fast cooling rates (from using uncoated steel dies) and minimal porosity provides excellent combinations of strength and ductility. Other advantages of SSM casting include the ability to produce complex shaped parts net shape, pressure tightness, tight dimensional tolerances and the ability to cast thin walls. | 0 | Metallurgy |
Static fatigue tests can estimate a material’s lifetime and hardness to different environments. However, measuring a static fatigue limit can take a long time, and it is hard to measure a material’s true static fatigue limit with full certainty. | 0 | Metallurgy |
Corrosion mapping by ultrasonics is a nonintrusive (noninvasive) technique which maps material thickness using ultrasonic techniques.
Variations in material thickness due to corrosion can be identified and graphically portrayed as an image.
The technique is widely used in the oil and gas industries for the in-service detection and characterization of corrosion in pipes and vessels.
The data is stored on a computer and may be color coded to show differences in thickness readings.
Corrosion may be mapped using Zero degree ultrasonic probes, an Eddy current array and/or Time of flight detection methods.
The book Nondestructive Examination of Underwater Welded Structures by Victor S. Davey describes a "fully automated dual axis robotic scanner used for corrosion mapping normally using a single zero degree compression probe scanned in a raster pattern over the area of interest."
He also goes on to explain that "typically a 4 mm by 4 mm raster" is used. | 0 | Metallurgy |
The first class of adenylyl cyclases occur in many bacteria including E. coli (as CyaA [unrelated to the Class II enzyme]). This was the first class of AC to be characterized. It was observed that E. coli deprived of glucose produce cAMP that serves as an internal signal to activate expression of genes for importing and metabolizing other sugars. cAMP exerts this effect by binding the transcription factor CRP, also known as CAP. Class I AC's are large cytosolic enzymes (~100 kDa) with a large regulatory domain (~50 kDa) that indirectly senses glucose levels. , no crystal structure is available for class I AC.
Some indirect structural information is available for this class. It is known that the N-terminal half is the catalytic portion, and that it requires two Mg ions. S103, S113, D114, D116 and W118 are the five absolutely essential residues. The class I catalytic domain () belongs to the same superfamily () as the palm domain of DNA polymerase beta (). Aligning its sequence onto the structure onto a related archaeal CCA tRNA nucleotidyltransferase () allows for assignment of the residues to specific functions: γ-phosphate binding, structural stabilization, DxD motif for metal ion binding, and finally ribose binding. | 1 | Gene expression + Signal Transduction |
Alvaro Alonso Barba was a secular Catholic priest and metallurgist born in Lepe in 1569.
Antonio (1786) says, "Baeticus ex oppido Lepe, apud Potosi"; hence Barba is assumed to be of Andalusian origin, from the ancient Roman province of Baetica.
He lived at Potosí during the period when its silver mines were most productive and luxury among the Spanish residents and mine owners had nearly reached its height. Barba divided his time between his priestly duties and a close study of the ores of this region and their treatment. There had been, since 1570, a complete revolution in the treatment of silver ores, through the application of mercury, and a number of improvements followed, of which Barba had knowledge.
In 1609, he invented the pan amalgamation process (in Spanish the cazo or fondo process) for extracting silver from ore by mixing it with salt and mercury and heating it in shallow copper vessels. In 1640 he published in Madrid a book entitled Arte de los Metales, the earliest work on South American ores and minerals. It includes information on mineral localities in Bolivia. The book has been republished in Spanish, French, English and German. | 0 | Metallurgy |
A study researching the role of splice site mutations in cancer supported that a splice site mutation was common in a set of women who were positive for breast and ovarian cancer. These women had the same mutation, according to the findings. An intronic single base-pair substitution destroys an acceptor site, thus activating a cryptic splice site, leading to a 59 base-pair insertion and chain termination. The four families with both breast and ovarian cancer had chain termination mutations in the N-terminal half of the protein. The mutation in this research example was located within the splice-site.
Splice-site mutations are recurrently found in key lymphoma genes like BCL7A or CD79B due to aberrant somatic hypermutation as the sequence targeted by AID overlaps with the sequences of the splice-sites. | 1 | Gene expression + Signal Transduction |
* Conversion coating
** Autophoretic, the registered trade name of a proprietary series of auto-depositing coatings specifically for ferrous metal substrates
** Anodising
** Chromate conversion coating
** Plasma electrolytic oxidation
** Phosphate (coating)
* Ion beam mixing
* Pickled and oiled, a type of plate steel coating
* Plating
** Electroless plating
** nickel plating coating using a different material to preserve mechanical properties
** Electroplating | 0 | Metallurgy |
The administration of a nucleoside-modified messenger RNA sequence can cause a cell to make a protein, which in turn could directly treat a disease or could function as a vaccine; more indirectly the protein could drive an endogenous stem cell to differentiate in a desired way.
The primary challenges of RNA therapy center on delivering the RNA to the appropriate cells. Challenges include the fact that naked RNA sequences naturally degrade after preparation; they may trigger the bodys immune system to attack them as an invader; and they are impermeable to the cell membrane. Once within the cell, they must then leave the cells transport mechanism to take action within the cytoplasm, which houses the necessary ribosomes.
Overcoming these challenges, mRNA as a therapeutic was first put forward in 1989 "after the development of a broadly applicable in vitro transfection technique." In the 1990s, mRNA vaccines for personalized cancer have been developed, relying on non-nucleoside modified mRNA. mRNA based therapies continue to be investigated as a method of treatment or therapy for both cancer as well as auto-immune, metabolic, and respiratory inflammatory diseases. Gene editing therapies such as CRISPR may also benefit from using mRNA to induce cells to make the desired Cas protein.
Since the 2010s, RNA vaccines and other RNA therapeutics have been considered to be "a new class of drugs". The first mRNA-based vaccines received restricted authorization and were rolled out across the world during the COVID-19 pandemic by Pfizer–BioNTech COVID-19 vaccine and Moderna, for example.
The 2023 Nobel Prize in Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman for the development of effective mRNA vaccines against COVID-19. | 1 | Gene expression + Signal Transduction |
NRIP1 has been shown to interact with:
* AHR,
* CTBP1
* CTBP2,
* DAX1,
* HDAC5,
* NR1B1,
* NR2B1,
* NR3A1,
* NR3C1,
* NR5A1, and
* YWHAQ. | 1 | Gene expression + Signal Transduction |
Paracrine signaling of growth factors between nearby cells has been shown to exacerbate carcinogenesis. In fact, mutant forms of a single RTK may play a causal role in very different types of cancer. The Kit proto-oncogene encodes a tyrosine kinase receptor whose ligand is a paracrine protein called stem cell factor (SCF), which is important in hematopoiesis (formation of cells in blood). The Kit receptor and related tyrosine kinase receptors actually are inhibitory and effectively suppresses receptor firing. Mutant forms of the Kit receptor, which fire constitutively in a ligand-independent fashion, are found in a diverse array of cancerous malignancies. | 1 | Gene expression + Signal Transduction |
CooA is a heme-containing transcription factor that responds to the presence of carbon monoxide. This protein forms homodimers and is a homolog of cAMP receptor protein. CooA regulates the expression of carbon monoxide dehydrogenase, an enzyme that catalyzes the oxidation of CO to CO. The most well-studied CooA homolog comes from Rhodospirillum rubrum (RrCooA), but the CooA homolog from Carboxydothermus hydrogenoformans (ChCooA) has been studied as well. The main difference between these two CooA homologs is the ferric heme coordination. For RrCooA, the ferric heme iron is bound to a cysteine and the amine of the N-terminal proline, while, in the ferrous state, a ligand switch occurs where a nearby histidine displaces the thiolate. For ChCooA, the heme iron is ligated by a histidine and the N-terminal amine in both the ferric and ferrous states. For both homologs, CO displaces the amine ligand and activates the protein to bind to its target DNA sequence. Several structures of CooA exist: RrCooA in the ferrous state (1FT9), ChCooA in the ferrous, imidazole-bound state (2FMY), and ChCooA in the ferrous, CO-bound state (2HKX). | 1 | Gene expression + Signal Transduction |
*ALDOA
*B3GALT6 NM_080605
*B4GALT3 NM_003779 Homo sapiens UDP-Gal:betaGlcNAc beta 1,4- galactosyltransferase, polypeptide 3
*B4GALT5 NM_004776
*B4GALT7 NM_007255
*GSK3A
*GSK3B
*TPI1
*PGK1 Phosphoglycerate kinase
*PGAM5
*ENOPH1 Enolase phosphatase
*LDHA Lactate dehydrogenase
*TALDO1 Transaldolase in pentose shunt
*TSTA3 Mannose metabolism | 1 | Gene expression + Signal Transduction |
After a hiatus, Norşuntepe was again occupied during the Early Bronze Age. During this period, the site was surrounded by a mudbrick city wall built on a stone foundation. There is evidence for copper production and some sort of palace or large, central building appears at the site in the final phases. In terms of material culture and architecture, there are clear parallels with Transcaucasia, and the Kura–Araxes culture. The latest Early Bronze Age phase in Norşuntepe ends in fire. | 0 | Metallurgy |
In mammals, microRNAs (miRNAs) regulate the transcriptional activity of about 60% of protein-encoding genes. Individual miRNAs can each target, and repress transcription of, on average, roughly 200 messenger RNAs of protein coding genes. The promoters of about one third of the 167 miRNAs evaluated by Vrba et al. in normal breast tissues were differentially hyper/hypo-methylated in breast cancers. A more recent study pointed out that the 167 miRNAs evaluated by Vrba et al. were only 10% of the miRNAs found expressed in breast tissues. This later study found that 58% of the miRNAs in breast tissue had differentially methylated regions in their promoters in breast cancers, including 278 hypermethylated miRNAs and 802 hypomethylated miRNAs.
One miRNA that is over-expressed about 100-fold in breast cancers is miR-182. MiR-182 targets the BRCA1 messenger RNA and may be a major cause of reduced BRCA1 protein expression in many breast cancers (also see BRCA1). | 1 | Gene expression + Signal Transduction |
* An array or slide is a collection of features spatially arranged in a two dimensional grid, arranged in columns and rows.
* Block or subarray: a group of spots, typically made in one print round; several subarrays/ blocks form an array.
* Case/control: an experimental design paradigm especially suited to the two-colour array system, in which a condition chosen as control (such as healthy tissue or state) is compared to an altered condition (such as a diseased tissue or state).
* Channel: the fluorescence output recorded in the scanner for an individual fluorophore and can even be ultraviolet.
* Dye flip or dye swap or fluor reversal: reciprocal labelling of DNA targets with the two dyes to account for dye bias in experiments.
* Scanner: an instrument used to detect and quantify the intensity of fluorescence of spots on a microarray slide, by selectively exciting fluorophores with a laser and measuring the fluorescence with a filter (optics) photomultiplier system.
* Spot or feature: a small area on an array slide that contains picomoles of specific DNA samples.
* For other relevant terms see:
** Glossary of gene expression terms
** Protocol (natural sciences) | 1 | Gene expression + Signal Transduction |
It has been discovered that this protein has a catalytic activity, in other words, it has the ability to increase the speed of chemical reactions which would not occur so fast. It is known to catalysis the following reaction (which requires the following cofactor: Mg(2+)):
ATP + RNA(n) ⇄ diphosphate + RNA(n+1)
Depending on the surroundings the optimal pH varies from 8 in the cytoplasm to 8.3 in the nucleus. | 1 | Gene expression + Signal Transduction |
Pure copper. Unlike other metals, copper is frequently used in its pure (99.9% Cu) unalloyed form for sheet and strip applications in roofing, exterior cladding, and flashing.
Tempering is a heat treatment technique used to increase the toughness of metals. Tempers determine the ductility of the metal, and therefore how well it forms and will hold its shape without additional support. In the U.S., copper is available in six tempers: 060 soft, hard cold rolled, cold rolled high yield, half hard, three quarter hard, and hard. In the U.K., only three designations exist: soft, half-hard, and hard. Copper and its alloys are defined in the U.S. in Standard Designations for Copper and Copper Alloys by ASTM; in Europe by BS EN 1172: 1997 - Copper and Copper Alloys in Europe; and in the U.K. by the British Standard Code of Practice CP143: Part12: 1970.
Cold rolled copper temper is by far the most popular in building construction in the U.S. It is less malleable than soft copper but is far stronger. Cold rolled hard tempered copper is often recommended for roofing and flashing installations. Roof sheets with higher tempers may be specified for certain applications.
Soft tempered copper is extremely malleable and offers far less resistance than cold rolled copper to the stresses induced by expansion and contraction. It is used for intricate ornamental work and where extreme forming is required, such as in complicated thru-wall flashing conditions.
The major use for high-yield copper is in flashing products, where malleability and strength are both important.
The thickness of sheet and strip copper is measured in the U.S. by its weight in ounces per square foot. Thicknesses commonly used in construction in the U.S. are between and . Since the industry often uses gauge numbers or actual thicknesses for sheet metal or other building materials, it is necessary to convert between the different measurement systems.
In Europe, phosphorus de-oxidized non-arsenical copper is used with the designation C106. The copper is rolled to thicknesses ranging between ( for curtain walling) but a thickness is usually used for roofing.
Alloyed copper. Copper alloys, such as brass and bronze, are also used in residential and commercial building structures. Variations in color stem primarily from differences in the alloy chemical composition.
Some of the more popular copper alloys and their associated Unified Numbering System (UNS) numbers developed by ASTM and SAE are as follows:
In practice, the term bronze may be used for a variety of copper alloys with little or no tin if they resemble true bronzes in color.
Further information on architectural copper alloys is available. | 0 | Metallurgy |
These proteins were originally characterized by their capacity to induce oncogenic transformation in a specific cell culture system, rat kidney fibroblasts. Application of the transforming growth factors to normal rat kidney fibroblasts induces the cultured cells to proliferate and overgrow, no longer subject to the normal inhibition caused by contact between cells. | 1 | Gene expression + Signal Transduction |
An Ellingham diagram is a graph showing the temperature dependence of the stability of compounds. This analysis is usually used to evaluate the ease of reduction of metal oxides and sulfides. These diagrams were first constructed by Harold Ellingham in 1944. In metallurgy, the Ellingham diagram is used to predict the equilibrium temperature between a metal, its oxide, and oxygen — and by extension, reactions of a metal with sulfur, nitrogen, and other non-metals. The diagrams are useful in predicting the conditions under which an ore will be reduced to its metal. The analysis is thermodynamic in nature and ignores reaction kinetics. Thus, processes that are predicted to be favourable by the Ellingham diagram can still be slow. | 0 | Metallurgy |
The durability assessment has been implemented in European design codes at the beginning of the 90s. It is required for designers to include the effects of long-term corrosion of steel rebar during the design stage, in order to avoid unacceptable damages during the service life of the structure. Different approaches are then available for the durability design. | 0 | Metallurgy |
The earliest sources of tin in the Early Bronze Age in the Near East are still unknown and the subject of much debate in archaeology.) Possibilities include minor now-depleted sources in the Near East, trade from Central Asia, Sub-Saharan Africa, Europe, or elsewhere.
It is possible that as early as 2500 BC, the Ore Mountains had begun exporting tin, using the well established Baltic amber trade route to supply Scandinavia as well as the Mediterranean with tin. By 2000 BC, the extraction of tin in Britain, France, Spain, and Portugal had begun and tin was traded to the Mediterranean sporadically from all these sources. Evidence of tin trade in the Mediterranean can be seen in a number of Bronze Age shipwrecks containing tin ingots such as the Uluburun off the coast of Turkey dated 1300 BC which carried over 300 copper bars weighing 10 tons, and approximately 40 tin bars weighing 1 ton. Evidence of direct tin trade between Europe and the Eastern Mediterranean has been demonstrated through the analysis of tin ingots dated to the 13th-12th centuries BC from sites in Israel, Turkey and modern-day Greece; tin ingots from Israel, for example, have been found to share chemical composition with tin from Cornwall and Devon (Great Britain).
While Sardinia does not appear to have much in terms of significant sources of tin, it does have rich copper and other mineral wealth and served as a centre for metals trade during the Bronze Age and likely actively imported tin from the Iberian Peninsula for export to the rest of the Mediterranean.
By classical Greek times, the tin sources were well established. Greece and the Western Mediterranean appear to have traded their tin from European sources, while the Middle East acquired their tin from Central Asian sources through the Silk Road. For example, Iron Age Greece had access to tin from Iberia by way of the Phoenicians who traded extensively there, from the Erzgebirge by way of the Baltic Amber Road overland route, or from Brittany and Cornwall through overland routes from their colony at Massalia (modern day Marseilles) established in the 6th century BC. In 450 BC, Herodotus described tin as coming from Northern European islands named the Cassiterides along the extreme borders of the world, suggesting very long-distance trade, likely from Britain, northwestern Iberia, or Brittany, supplying tin to Greece and other Mediterranean cultures. The idea that the Phoenicians went to Cornwall for its tin and supplied it to the whole of the Mediterranean has no archaeological basis and is largely considered a myth.
The early Roman world was mainly supplied with tin from its Iberian provinces of Gallaecia and Lusitania and to a lesser extent Tuscany. Pliny mentions that in 80 BC, a senatorial decree halted all mining on the Italian Peninsula, stopping any tin mining activity in Tuscany and increasing Roman dependence on tin from Brittany, Iberia, and Cornwall. After the Roman conquest of Gaul, Brittany's tin deposits saw intensified exploitation after the first century BC. With the exhaustion of the Iberian tin mines, Cornwall became a major supplier of tin for the Romans after the 3rd century AD.
Throughout the medieval period, demand for tin increased as pewter gained popularity. Brittany and Cornwall remained the major producers and exporters of tin throughout the Mediterranean through to modern times. | 0 | Metallurgy |
The earliest evidence for iron-making is a small number of iron fragments with the appropriate amounts of carbon admixture found in the Proto-Hittite layers at Kaman-Kalehöyük and dated to 2200–2000 BCE. Souckova-Siegolová (2001) shows that iron implements were made in Central Anatolia in very limited quantities around 1800 BCE and were in general use by elites, though not by commoners, during the New Hittite Empire (~1400–1200 BCE).
Archaeologists have found indications of iron working in Ancient Egypt, somewhere between the Third Intermediate Period and 23rd Dynasty (ca. 1100–750 BCE). Significantly though, they have found no evidence of iron ore smelting in any (pre-modern) period. In addition, very early instances of carbon steel were in production around 2000 years ago (around the first-century CE.) in northwest Tanzania, based on complex preheating principles. These discoveries are significant for the history of metallurgy.
Most early processes in Europe and Africa involved smelting iron ore in a bloomery, where the temperature is kept low enough so that the iron does not melt. This produces a spongy mass of iron called a bloom, which then must be consolidated with a hammer to produce wrought iron. The earliest evidence to date for the bloomery smelting of iron is found at Tell Hammeh, Jordan ([http://www.ironsmelting.net/www/smelting/]), and dates to 930 BCE (C14 dating). | 0 | Metallurgy |
One of the methods of archaeometallurgy is the study of modern metals and alloys to explain and understand the use of metals in the past. A study conducted by the department of Particle Physics and Astrophysics at Weizmann Institute of Science and the department of Archaeology at the University of Haifia analyzed the chemical composition and the mass of different denominations of Euro coinage. They concluded that even with modern standards and technology, there is a considerable variation within the "same" denomination of coin. This simple conclusion can be used to further analyze discoveries of ancient currency. | 0 | Metallurgy |
The source material was pig iron produced by a blast furnace using charcoal and the manganese rich iron ore from the Dannemora mine. A V-shaped hearth using charcoal was used to heat up the pig iron bar that was presented to a tuyere that decarbonized it and made it melt and fall in drops that solidified in a pool of slag where the decarburization continued. The iron drops were picked up with an iron bar and presented again in front of the tuyere and one by one agglomerated into a ball. That heterogeneous iron was full of slag and the carbon content ranged from pure iron to nearly pig iron. It was therefore reheated in a chafery and hammered and folded using a waterwheel powered trip hammer.
The ore from Dannemora was very low in sulphur and high in manganese. It is possible the manganese bonded with the impurities during the oxidation, creating a pretty pure wrought iron. The use of charcoal prevented the contamination with impurities usually associated with the usage of coal or coke, of which Sweden has none. In England, the chafery might use coal or coke, as in this stage the iron is solidified and the contamination remain low.
The iron was sold to England, where it was recarbonized into blister steel using the cementation process. This steel still contain some slag, and if the carbon was around 1% at the surface, it was lower in the center. The blister steel was than purchased by Benjamin Huntsman who melted it in a crucible heated using coke and poured it. This modern crucible steel was different from the medieval wootz, but was homogeneous and without slag. | 0 | Metallurgy |
In the brewing industry flocculation has a different meaning. It is a very important process in fermentation during the production of beer where cells form macroscopic flocs. These flocs cause the yeast to sediment or rise to the top of a fermentation at the end of the fermentation. Subsequently, the yeast can be collected (cropped) from the top (ale fermentation) or the bottom (lager fermentation) of the fermenter in order to be reused for the next fermentation.
Yeast flocculation is primarily determined by the calcium concentration, often in the 50-100ppm range. Calcium salts can be added to cause flocculation, or the process can be reversed by removing calcium by adding phosphate to form insolubable calcium phosphate, adding excess sulfate to form insoluble calcium sulfate, or adding EDTA to chelate the calcium ions. While it appears similar to sedimentation in colloidal dispersions, the mechanisms are different. | 0 | Metallurgy |
Carbonyl metallurgy is used to manufacture products of iron, nickel, steel, and other metals. Coatings are produced by vapor plating using metal carbonyl vapors. These are metal-ligand complexes where carbon monoxide is bonded to individual atoms of metals .
Iron carbonyl is stable as iron pentacarbonyl, where five carbon monoxide molecules are pendently bonded to the iron atom, while nickel carbonyl is stable as nickel tetracarbonyl, which has four carbon monoxide molecules pendantly bonded to the nickel atom. Both can be formed by the exposure of the powdered metal to carbon monoxide gas at temperatures of around 75 degrees Celsius. Both the metal carbonyls decompose near 175 °C, resulting in a vapor plated metallic coating. The thickness of the vapor plated deposit can be increased to desired thicknesses by controlling the amount of metal carbonyl used and the duration of the plating process.
Vale Inco produces over 100 million pounds (ca. 45000 tonnes) of nickel metal annually by the carbonyl process. The carbonyl process has been used to produce molds in custom shapes for industry. Such molds have been used in plastic molding and other manufacturing techniques.
William Jenkin developed many of the techniques and procedures used in carbonyl metallurgy.
Carbonyl metallurgy is useful as a low-temperature metal coating technique that may find many applications in the future. | 0 | Metallurgy |
The Jameson Cell grew out of a long-term research program aimed at improving the recovery of fine particles by flotation. The work started at Imperial College London, and continued when Jameson moved in 1978 to the University of Newcastle, NSW, Australia, where he is Laureate Professor (2015). | 0 | Metallurgy |
Expression of genes in mammals can be upregulated when signals are transmitted to the promoters associated with the genes. Cis-regulatory DNA sequences that are located in DNA regions distant from the promoters of genes can have very large effects on gene expression, with some genes undergoing up to 100-fold increased expression due to such a cis-regulatory sequence. These cis-regulatory sequences include enhancers, silencers, insulators and tethering elements. Among this constellation of sequences, enhancers and their associated transcription factor proteins have a leading role in the regulation of gene expression.
Enhancers are sequences of the genome that are major gene-regulatory elements. Enhancers control cell-type-specific gene expression programs, most often by looping through long distances to come in physical proximity with the promoters of their target genes. In a study of brain cortical neurons, 24,937 loops were found, bringing enhancers to promoters. Multiple enhancers, each often at tens or hundred of thousands of nucleotides distant from their target genes, loop to their target gene promoters and coordinate with each other to control expression of their common target gene.
The schematic illustration in this section shows an enhancer looping around to come into close physical proximity with the promoter of a target gene. The loop is stabilized by a dimer of a connector protein (e.g. dimer of CTCF or YY1), with one member of the dimer anchored to its binding motif on the enhancer and the other member anchored to its binding motif on the promoter (represented by the red zigzags in the illustration). Several cell function specific transcription factor proteins (in 2018 Lambert et al. indicated there were about 1,600 transcription factors in a human cell) generally bind to specific motifs on an enhancer and a small combination of these enhancer-bound transcription factors, when brought close to a promoter by a DNA loop, govern the level of transcription of the target gene. Mediator (coactivator) (a complex usually consisting of about 26 proteins in an interacting structure) communicates regulatory signals from enhancer DNA-bound transcription factors directly to the RNA polymerase II (RNAP II) enzyme bound to the promoter.
Enhancers, when active, are generally transcribed from both strands of DNA with RNA polymerases acting in two different directions, producing two eRNAs as illustrated in the Figure. An inactive enhancer may be bound by an inactive transcription factor. Phosphorylation of the transcription factor may activate it and that activated transcription factor may then activate the enhancer to which it is bound (see small red star representing phosphorylation of a transcription factor bound to an enhancer in the illustration). An activated enhancer begins transcription of its RNA before activating a promoter to initiate transcription of messenger RNA from its target gene. | 1 | Gene expression + Signal Transduction |
Copper technology may date back to the 4th millennium BCE in the Himalaya region.
It is the first element to be discovered in metallurgy,
Copper and its alloys were also used to create copper-bronze images such as Buddhas or Hindu/Mahayana Buddhist deities. Xuanzang also noted that there were copper-bronze Buddha images in Magadha. In Varanasi, each stage of the image manufacturing process is handled by a specialist.
Other metal objects made by Indian artisans include lamps. Copper was also a component in the razors for the tonsure ceremony.
One of the most important sources of history in the Indian subcontinent are the royal records of grants engraved on copper-plate grants (tamra-shasan or tamra-patra). Because copper does not rust or decay, they can survive indefinitely. Collections of archaeological texts from the copper-plates and rock-inscriptions have been compiled and published by the Archaeological Survey of India during the past century. The earliest known copper-plate known as the Sohgaura copper-plate is a Maurya record that mentions famine relief efforts. It is one of the very few pre-Ashoka Brahmi inscriptions in India. | 0 | Metallurgy |
Arsenical bronze has seen little use in the modern period. It appears that the closest equivalent goes by the name of arsenical copper, defined as copper with under 0.5 wt% As, below the accepted percentage in archaeological artefacts. The presence of 0.5 wt% arsenic in copper lowers the electrical conductivity to 34% of that of pure copper, and even as little as 0.05 wt% decreases it by 15%. | 0 | Metallurgy |
Gold extraction is the extraction of gold from dilute ores using a combination of chemical processes. Gold mining produces about 3600 tons annually, and another 300 tons is produced from recycling.
Since the 20th century, gold has been principally extracted in a cyanide process by leaching the ore with cyanide solution. The gold may then be further refined by gold parting, which removes other metals (principally silver) by blowing chlorine gas through the molten metal. Historically, small particles of gold were amalgamated with mercury, and then concentrated by boiling away the mercury. The mercury method is still used in some small operations. | 0 | Metallurgy |
Subsets and Splits