Nikiya Anton Bettey 2021: 06/25/22

Saturday, June 25, 2022

06-25-2022-0547 - memory t cell

Memory T cells are a subset of T lymphocytes that might have some of the same functions as memory B cells. Their lineage is unclear.

https://en.wikipedia.org/wiki/Memory_T_cell

https://en.wikipedia.org/wiki/Pyroptosis

Clonal selection theory is a scientific theory in immunology that explains the functions of cells of the immune system (lymphocytes) in response to specific antigens invading the body. The concept was introduced by Australian doctor Frank Macfarlane Burnet in 1957, in an attempt to explain the great diversity of antibodies formed during initiation of the immune response.^[1]^[2] The theory has become the widely accepted model for how the human immune system responds to infection and how certain types of B and T lymphocytes are selected for destruction of specific antigens.^[3]

https://en.wikipedia.org/wiki/Clonal_selection

M1 macrophages[edit]

Classically activated macrophages (M1) were named by G. B. Mackaness in the 1960s.^[20] M1-activation in vitro is evoked by treatment with TLR ligands such as bacterial lipopolysaccharide (LPS) - typical for Gram-negative bacteria and lipoteichoic acid (LTA) - typical for Gram-positive bacteria, granulocyte-macrophage colony-stimulating factor(GM-CSF) or combination of LPS and interferon-gamma (IFN-γ).^[2]^[21]^[22] Similarly in vivo, classically activated macrophages arise in response to IFN-γ produced by Th1 lymphocytes or by natural killer cells (NK), and tumor-necrosis factor (TNF), produced by antigen-presenting cells (APCs).^[22]

M1-activated macrophages express transcription factors such as Interferon-Regulatory Factor (IRF5), Nuclear Factor of kappa light polypeptide gene enhancer (NF-κB), Activator-Protein (AP-1) and STAT1. This leads to enhanced microbicidal capacity and secretion of high levels of pro-inflammatory cytokines: e.g. IFN-γ, IL-1, IL-6, IL-12, IL-23and TNFα. Moreover, to increase their pathogen-killing ability, they produce increased amounts of chemicals called reactive oxygen species (ROS) and nitrogen radicals (caused by upregulation of inducible NO synthase iNOS).^[5]^[23] Thanks to their ability to fight pathogens, M1 macrophages are present during acute infectious diseases. A number of studies have shown that bacterial infection induces polarization of macrophages toward the M1 phenotype, resulting in phagocytosis and intracellular killing of bacteria in vitroand in vivo. For instance, Listeria monocytogenes, a Gram positive bacteria causing listeriosis is shown to induce an M1 polarization,^[24]^[25] as well as Salmonella typhi (the agent of typhoid fever) and Salmonella typhimurium (causing gastroenteritis), which are shown to induce the M1 polarization of human and murine macrophages.^[25] Macrophages are polarized toward the M1 profile during the early phase of Mycobacterium tuberculosis infection,^[26] as well as other mycobacterial species such as Mycobacterium ulcerans(causing Buruli ulcer disease) and Mycobacterium avium.^[25]

Improper and untimely control of M1 macrophage-mediated inflammatory response can lead to disruption of normal tissue homeostasis and impede vascular repair. An uncontrolled production of pro-inflammatory cytokines during the inflammation can lead to the formation of cytokine storm, thereby contributing to the pathogenesis of severe sepsis.^[27] In order to counteract the inflammatory response, macrophages undergo apoptosis or polarize to an M2 phenotype to protect the host from the excessive injury.^[23]

https://en.wikipedia.org/wiki/Macrophage_polarization#M1_macrophages

Leukocyte extravasation (also commonly known as leukocyte adhesion cascade or diapedesis – the passage of cells through the intact vessel wall) is the movement of leukocytes out of the circulatory system and towards the site of tissue damage or infection. This process forms part of the innate immune response, involving the recruitment of non-specific leukocytes. Monocytes also use this process in the absence of infection or tissue damage during their development into macrophages.

https://en.wikipedia.org/wiki/Leukocyte_extravasation

Chemotaxis (from chemo- + taxis) is the movement of an organism or entity in response to a chemical stimulus.^[1] Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food (e.g., glucose) by swimming toward the highest concentration of food molecules, or to flee from poisons (e.g., phenol). In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and development (e.g., migration of neurons or lymphocytes) as well as in normal function and health (e.g., migration of leukocytes during injury or infection).^[2] In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis.^[3] The aberrant chemotaxis of leukocytes and lymphocytes also contribute to inflammatory diseases such as atherosclerosis, asthma, and arthritis.^[4]^[5]^[6]^[7] Sub-cellular components, such as the polarity patch generated by mating yeast, may also display chemotactic behavior.^[8]

https://en.wikipedia.org/wiki/Chemotaxis

In chemistry, phosphorylation of is the attachment of a phosphate group to a molecule or an ion. This process (and its inverse, dephosphorylation) are common in biology. Protein phosphorylation often activates (or deactivates) many enzymes.^[1]^[2]

Glucose[edit]

Phosphorylation of sugars is often the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by

D-glucose + ATP → D-glucose-6-phosphate + ADP

ΔG° = −16.7 kJ/mol (° indicates measurement at standard condition)

Hepatic cells are freely permeable to glucose, and the initial rate of phosphorylation of glucose is the rate-limiting step in glucose metabolism by the liver (ATP-D-glucose 6-phosphotransferase) and non-specific hexokinase (ATP-D-hexose 6-phosphotransferase).^[3]

The role of glucose 6-phosphate in glycogen synthase: High blood glucose concentration causes an increase in intracellular levels of glucose 6 phosphate in liver, skeletal muscle and fat (adipose) tissue. (ATP-D-glucose 6-phosphotransferase) and non-specific hexokinase (ATP-D-hexose 6-phosphotransferase). In liver, synthesis of glycogen is directly correlated by blood glucose concentration and in skeletal muscle and adipocytes, glucose has a minor effect on glycogen synthase. High blood glucose releases insulin, stimulating the trans location of specific glucose transporters to the cell membrane.^[3]^[4]

The liver's crucial role in controlling blood sugar concentrations by breaking down glucose into carbon dioxide and glycogen is characterized by the negative delta G value, which indicates that this is a point of regulation with. The hexokinase enzyme has a low Km, indicating a high affinity for glucose, so this initial phosphorylation can proceed even when glucose levels at nanoscopic scale within the blood.

The phosphorylation of glucose can be enhanced by the binding of Fructose-6-phosphate, and lessened by the binding fructose-1-phosphate. Fructose consumed in the diet is converted to F1P in the liver. This negates the action of F6P on glucokinase,^[5] which ultimately favors the forward reaction. The capacity of liver cells to phosphorylate fructose exceeds capacity to metabolize fructose-1-phosphate. Consuming excess fructose ultimately results in an imbalance in liver metabolism, which indirectly exhausts the liver cell's supply of ATP.^[6]

Allosteric activation by glucose 6 phosphate, which acts as an effector, stimulates glycogen synthase, and glucose 6 phosphate may inhibit the phosphorylation of glycogen synthase by cyclic AMP-stimulated protein kinase.^[4]

Phosphorylation of glucose is imperative in processes within the body. For example, phosphorylating glucose is necessary for insulin-dependent mechanistic target of rapamycinpathway activity within the heart. This further suggests a link between intermediary metabolism and cardiac growth.^[7]

Protein phosphorylation[edit]

Protein phosphorylation is the most abundant post-translational modification in eukaryotes. Phosphorylation can occur on serine, threonine and tyrosine side chains (often called 'residues') through phosphoester bond formation, on histidine, lysine and arginine through phosphoramidate bonds, and on aspartic acid and glutamic acid through mixed anhydride linkages. Recent evidence confirms widespread histidine phosphorylation at both the 1 and 3 N-atoms of the imidazole ring.^[12]^[13] Recent work demonstrates widespread human protein phosphorylation on multiple non-canonical amino acids, including motifs containing phosphorylated histidine, aspartate, glutamate, cysteine, arginine and lysine in HeLa cell extracts.^[14] However, due to the chemical lability of these phosphorylated residues, and in marked contrast to Ser, Thr and Tyr phosphorylation, the analysis of phosphorylated histidine (and other non-canonical amino acids) using standard biochemical and mass spectrometric approaches is much more challenging^[14]^[15]^[16]and special procedures and separation techniques are required for their preservation alongside classical Ser, Thr and Tyr phosphorylation.^[17]

The prominent role of protein phosphorylation in biochemistry is illustrated by the huge body of studies published on the subject (as of March 2015, the MEDLINE database returns over 240,000 articles, mostly on protein phosphorylation).

ATP[edit]

ATP, the "high-energy" exchange medium in the cell, is synthesized in the mitochondrion by addition of a third phosphate group to ADP in a process referred to as oxidative phosphorylation. ATP is also synthesized by substrate-level phosphorylation during glycolysis. ATP is synthesized at the expense of solar energy by photophosphorylation in the chloroplasts of plant cells.

https://en.wikipedia.org/wiki/Phosphorylation

Moiety conservation is the conservation of a subgroup in a chemical species, which is cyclically transferred from one molecule to another.

Example[edit]

Adenosine diphosphate (ADP) is a subgroup that remains unchanged when it is phosphorylated to create adenosine triphosphate (ATP) and then dephosphorylated back to ADP forming a conserved cycle. Moiety-conserved cycles in nature exhibit unique network control features which can be elucidated using techniques such as metabolic control analysis.

https://en.wikipedia.org/wiki/Moiety_conservation

Paramecium (/ˌpærəˈmiːʃ(i)əm/ PARR-ə-MEE-sh(ee-)əm, /-siəm/ -⁠see-əm; also spelled Paramoecium)^[1] is a genus of eukaryotic, unicellular ciliates, commonly studied as a representative of the ciliate group. Paramecia are widespread in freshwater, brackish, and marine environments and are often very abundant in stagnant basins and ponds. Because some species are readily cultivated and easily induced to conjugate and divide, it has been widely used in classrooms and laboratories to study biological processes. Its usefulness as a model organism has caused one ciliate researcher to characterize it as the "white rat" of the phylum Ciliophora.^[2]

https://en.wikipedia.org/wiki/Paramecium

Necrotaxis embodies a special type of chemotaxis when the chemoattractant molecules are released from necrotic or apoptotic cells.^[1]^[2] Investigations of necrotaxis proved that ability to sense substances released from dying cells is present in unicellular level (e.g. Paramecium) as well as in vertebrates (see interactions of leukocytes with corpse of dead cells). Composition of the substances inducing necrotaxis is rather complex, some of them are still obscure. However, depending on the chemical character of molecules released, necrotaxis can accumulate or repel cells,^[3] which underlines the pathophysiological significance of the phenomenon.^[4] Model experiments of necrotaxis deal with special way of killing the target cells. For this purpose laser irradiation is used frequently. Several mathematical models are also available to describe the special locomotor characteristics of this migratory response of cells.^[5]

https://en.wikipedia.org/wiki/Necrotaxis

A cyclic nucleotide (cNMP) is a single-phosphate nucleotide with a cyclic bond arrangement between the sugar and phosphate groups. Like other nucleotides, cyclic nucleotides are composed of three functional groups: a sugar, a nitrogenous base, and a single phosphate group. As can be seen in the cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) images, the 'cyclic' portion consists of two bonds between the phosphate group and the 3' and 5' hydroxyl groups of the sugar, very often a ribose.

Their biological significance includes a broad range of protein-ligand interactions. They have been identified as secondary messengers in both hormone and ion-channel signalling in eukaryotic cells, as well as allosteric effector compounds of DNA binding proteins in prokaryotic cells. cAMP and cGMP are currently the most well documented cyclic nucleotides, however there is evidence that cCMP(cytosine) is also involved in eukaryotic cellular messaging. The role of cyclic uridine monophosphate (cUMP) is even less well known.

Discovery of cyclic nucleotides has contributed greatly to the understanding of kinase and phosphatase mechanisms, as well as protein regulation in general. Although more than 50 years have passed since their initial discovery, interest in cyclic nucleotides and their biochemical and physiological significance continues.

https://en.wikipedia.org/wiki/Cyclic_nucleotide

**Chemotaxis in diseases**^{[citation needed]}
Type of disease	Chemotaxis increased	Chemotaxis decreased
Infections	Inflammations	AIDS, Brucellosis
Chemotaxis results in the disease	—	Chédiak–Higashi syndrome, Kartagener syndrome
Chemotaxis is affected	Atherosclerosis, arthritis, periodontitis, psoriasis, reperfusion injury, metastatic tumors	Multiple sclerosis, Hodgkin disease, male infertility
Intoxications	Asbestos, benzpyrene	Hg and Cr salts, ozone

Mathematical models[edit]

Several mathematical models of chemotaxis were developed depending on the type of

Migration (e.g., basic differences of bacterial swimming, movement of unicellular eukaryotes with cilia/flagellum and amoeboid migration)
Physico-chemical characteristics of the chemicals (e.g., diffusion) working as ligands
Biological characteristics of the ligands (attractant, neutral, and repellent molecules)
Assay systems applied to evaluate chemotaxis (see incubation times, development, and stability of concentration gradients)
Other environmental effects possessing direct or indirect influence on the migration (lighting, temperature, magnetic fields, etc.)

Although interactions of the factors listed above make the behavior of the solutions of mathematical models of chemotaxis rather complex, it is possible to describe the basic phenomenon of chemotaxis-driven motion in a straightforward way. Indeed, let us denote with $\varphi$ the spatially non-uniform concentration of the chemo-attractant and $\nabla \varphi$ as its gradient. Then the chemotactic cellular flow (also called current) ${\bf {J}}$ that is generated by the chemotaxis is linked to the above gradient by the law:^[70]

{\bf {J}}=C\chi (\varphi )\nabla \varphi

where $C$ is the spatial density of the cells and $\chi$ is the so-called ’Chemotactic coefficient’ - $\chi$ is often not constant, but a decreasing function of the chemo-attractant. For some quantity $\rho$ that is subject to total flux ${\bf {J}}$ and generation/destruction term $S$ , it is possible to formulate a continuity equation:

{\partial \rho  \over {\partial t}}+\nabla \cdot {\bf {J}}=S

where $\nabla \cdot ()$ is the divergence. This general equation applies to both the cell density and the chemo-attractant. Therefore, incorporating a diffusion flux into the total flux term, the interactions between these quantities are governed by a set of coupled reaction-diffusion partial differential equations describing the change in $C$ and $\varphi$ :^[70]

{\begin{aligned}{\partial C \over {\partial t}}&=f(C)+\nabla \cdot \left[D_{C}\nabla C-C\chi (\varphi )\nabla \varphi \right]\\{\partial \varphi  \over {\partial t}}&=g(\varphi ,C)+\nabla \cdot (D_{\varphi }\nabla \varphi )\end{aligned}}

where $f(C)$ describes the growth in cell density, $g(\varphi ,C)$ is the kinetics/source term for the chemo-attractant, and the diffusion coefficients for cell density and the chemo-attractant are respectively $D_{C}$ and $D_{\varphi }$ .

Spatial ecology of soil microorganisms is a function of their chemotactic sensitivities towards substrate and fellow organisms.^[71]^{[non-primary source needed]}^{[non-primary source needed]} The chemotactic behavior of the bacteria was proven to lead to non-trivial population patterns even in the absence of environmental heterogeneities. The presence of structural pore scale heterogeneities has an extra impact on the emerging bacterial patterns.

Types of taxes (directional movements in Biology)

Aerotaxis (stimulation by oxygen)
Anemotaxis (by wind)
Barotaxis (by pressure)
Chemotaxis (by chemicals)
Durotaxis (by stiffness)
Electrotaxis or Galvanotaxis (by electric current)
Gravitaxis (by gravity)
Hydrotaxis (by moisture)
Magnetotaxis (by magnetic field)
Phototaxis (by light)
Rheotaxis (by fluid flow)
Thermotaxis (by changes in temperature)
Thigmotaxis (by physical contact)

Categories:

https://en.wikipedia.org/wiki/Chemotaxis

An amoeba (/əˈmiːbə/; less commonly spelled ameba or amœba; plural am(o)ebas or am(o)ebae /əˈmiːbi/),^[1] often called an amoeboid, is a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods.^[2] Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals.^[3]^[4]^[5]^[6]^[7]

https://en.wikipedia.org/wiki/Amoeba

Magnetotaxis is a process implemented by a diverse group of Gram-negative bacteria that involves orienting and coordinating movement in response to Earth's magnetic field.^[1]This process is mainly carried out by microaerophilic and anaerobic bacteria found in aquatic environments such as salt marshes, seawater, and freshwater lakes.^[2] By sensing the magnetic field, the bacteria are able to orient themselves towards environments with more favorable oxygen concentrations. This orientation towards more favorable oxygen concentrations allows the bacteria to reach these environments faster as opposed to random movement through Brownian motion.^[3]

https://en.wikipedia.org/wiki/Magnetotaxis

Magnetospirillum is a Gram-negative, microaerophilic genus of magnetotactic bacterium, first isolated from pond water by the microbiologist R. P. Blakemore in 1975.^[2]^[3] They have a spiral (helical) shape and are propelled by a polar flagellum at each end of their cells. Four species have been described: M. magnetotacticum strain MS-1 (originally classified as Aquaspirillum magnetotacticum;^[4] M. magneticum strain AMB-1;^[5] M. gryphiswaldense^[6] and M. bellicus.^[7]

https://en.wikipedia.org/wiki/Magnetospirillum

Magnetosomes are membranous structures present in magnetotactic bacteria (MTB). They contain iron-rich magnetic particles that are enclosed within a lipid bilayer membrane. Each magnetosome can often contain 15 to 20 magnetite crystals that form a chain which acts like a compass needle to orient magnetotactic bacteria in geomagnetic fields, thereby simplifying their search for their preferred microaerophilic environments. Recent research has shown that magnetosomes are invaginations of the inner membrane and not freestanding vesicles.^[2] Magnetite-bearing magnetosomes have also been found in eukaryotic magnetotactic algae, with each cell containing several thousand crystals.

Overall, magnetosome crystals have high chemical purity, narrow size ranges, species-specific crystal morphologies and exhibit specific arrangements within the cell. These features indicate that the formation of magnetosomes is under precise biological control and is mediated biomineralization.

Magnetotactic bacteria usually mineralize either iron oxide magnetosomes, which contain crystals of magnetite (Fe3O4), or iron sulfide magnetosomes, which contain crystals of greigite (Fe3S4). Several other iron sulfide minerals have also been identified in iron sulfide magnetosomes—including mackinawite (tetragonal FeS) and a cubic FeS—which are thought to be precursors of Fe3S4. One type of magnetotactic bacterium present at the oxic-anoxic transition zone (OATZ) of the southern basin of the Pettaquamscutt River Estuary, Narragansett, Rhode Island, United States is known to produce both iron oxide and iron sulfide magnetosomes.^[3]^[4]

Magnetotactic bacteria are widespread, motile, diverse prokaryotes that biomineralize a unique organelle called the magnetosome. A magnetosome consists of a nano-sized crystal of a magnetic iron mineral, which is enveloped by a lipid bilayer membrane. In the cells of most all magnetotactic bacteria, magnetosomes are organized as well-ordered chains. The magnetosome chain causes the cell to behave as a motile, miniature compass needle where the cell aligns and swims parallel to magnetic field lines.^[5]

The magnetic dipole moment of the cell is often large enough that its interaction with Earth’s magnetic field overcomes the thermal forces that tend to randomize the orientation of the cell in its aqueous surroundings. Magnetotactic bacteria use aerotaxis as well. Aerotaxis is a response to changes in oxygen concentration that will favor swimming towards a zone of optimal oxygen concentration. Lakes or oceans oxygen concentration is commonly dependent on depth. If the Earth’s magnetic field has a significant downward slant, the orientation along field lines aids in the search for the optimal concentration; this process is called magneto-aerotaxis.

Magnetites[edit]

Lab Growth of magnetite crystals under controlled conditions to simulate growth within the magnetosome.^[10]

Magnetite crystals are encased in the magnetosome giving the MTB its magnetic properties. These crystals can either be made of iron oxide or sulfide. The MTB may either have iron oxide or sulfide but not both. Certain subgroups of the Pseudomonadota in the domain of Bacteria have been found through analyses of the MTB’s RNA to only use iron oxide which is the more common material. Another smaller subdivision of the Pseudomonadota that are part of a sulfide reducing bacteria use iron sulfide. Scientists say this suggests independent evolution of the same trait. The magnetite crystals have been observed in three different morphologies, cuboid, rectangular, and arrowhead shaped.^[10]

When the magnetotactic crystals are in an unstable arrangement the whole magnetosome will collapse without additional support. The collapse can occur during diagenesis and dolomitization. The magnetosome shape and elastic properties of biological membranes are what is holding the chains together, as well as the linearity and the connection to the cytoskeleton. With how much the geometries effect the stabilization of the chains of magnetosomes shows that they are intrinsically unstable. The cell wall and associated membrane structures have been thought to act to prevent magnetosome chain collapse. There has been data collected that indicates that magnetosome linearity persists long after cells are disrupted. Consistent with prior observations, in some magnetococcus, the magnetosome chains pass through the cell interior, precluding continuous contact with the cell wall and imply additional support structures exist in some species.^[11]

https://en.wikipedia.org/wiki/Magnetosome

Pages in category "Magnetoreception"

The following 5 pages are in this category, out of 5 total. This list may not reflect recent changes (learn more).

M

Categories:

https://en.wikipedia.org/wiki/Category:Magnetoreception

Magnetic storage or magnetic recording is the storage of data on a magnetized medium. Magnetic storage uses different patterns of magnetisation in a magnetizable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads.

https://en.wikipedia.org/wiki/Magnetic_storage

Cartridge memory and self-identification[edit]

Some tape cartridges, notably LTO cartridges, have small associated data storage chips built into the cartridges to record metadata about the tape, such as the type of encoding, the size of the storage, dates and other information. It is also common^{[citation needed]} for tape cartridges to have bar codes on their labels in order to assist an automated tape library.

In 2014, Sony announced that they had developed, using a new vacuum thin-film forming technology able to form extremely fine crystal particles, a tape storage technology with the highest reported magnetic tape data density, 148 Gbit/in² (23 Gbit/cm²), potentially allowing a native tape capacity of 185 TB.^[26] It was further developed by Sony, with announcement in 2017, about reported data density of 201 Gbit/in² (31 Gbit/cm²), giving standard compressed tape capacity of 330 TB.^[27]

https://en.wikipedia.org/wiki/Magnetic-tape_data_storage#Cartridge_memory_and_self-identification

Ferrocement or ferro-cement^[1] is a system of construction using reinforced mortar^[2] or plaster (lime or cement, sand, and water) applied over an "armature" of metal mesh, woven, expanded metal, or metal-fibers, and closely spaced thin steel rods such as rebar. The metal commonly used is iron or some type of steel, and the mesh is made with wire with a diameter between 0.5 mm and 1 mm. The cement is typically a very rich mix of sand and cement in a 3:1 ratio; when used for making boards, no gravel is used, so that the material is not concrete.

https://en.wikipedia.org/wiki/Ferrocement

Thiocyanate (also known as rhodanide) is the anion [SCN]⁻. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Mercury(II) thiocyanate was formerly used in pyrotechnics.

Thiocyanate is analogous to the cyanate ion, [OCN]⁻, wherein oxygen is replaced by sulfur. [SCN]⁻ is one of the pseudohalides, due to the similarity of its reactions to that of halide ions. Thiocyanate used to be known as rhodanide (from a Greek word for rose) because of the red colour of its complexes with iron. Thiocyanate is produced by the reaction of elemental sulfur or thiosulfate with cyanide:

8 CN⁻ + S₈ → 8 SCN⁻

CN⁻ + S
2O2−
3 → SCN⁻ + SO2−
3

The second reaction is catalyzed by thiosulfate sulfurtransferase, a hepatic mitochondrial enzyme, and by other sulfur transferases, which together are responsible for around 80% of cyanide metabolism in the body.^[2]

https://en.wikipedia.org/wiki/Thiocyanate

Pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens in several classes of chemical compounds.^[1] Pseudohalogens occur in pseudohalogen molecules, inorganic molecules of the general forms Ps–Ps or Ps–X (where Ps is a pseudohalogen group), such as cyanogen; pseudohalide anions, such as cyanide ion; inorganic acids, such as hydrogen cyanide; as ligands in coordination complexes, such as ferricyanide; and as functional groups in organic molecules, such as the nitrile group. Well-known pseudohalogen functional groups include cyanide, cyanate, thiocyanate, and azide.

https://en.wikipedia.org/wiki/Pseudohalogen

In chemistry, an interhalogen compound is a molecule which contains two or more different halogen atoms (fluorine, chlorine, bromine, iodine, or astatine) and no atoms of elements from any other group.

Some interhalogens, such as BrF3, IF5, and ICl, are good halogenating agents. BrF5 is too reactive to generate fluorine. Beyond that, iodine monochloride has several applications, including helping to measure the saturation of fats and oils, and as a catalyst for some reactions. A number of interhalogens, including IF7, are used to form polyhalides.^[1]

Similar compounds exist with various pseudohalogens, such as the halogen azides (FN3, ClN3, BrN3, and IN3) and cyanogen halides (FCN, ClCN, BrCN, and ICN).

https://en.wikipedia.org/wiki/Interhalogen

No astatine fluorides have been discovered yet. Their absence has been speculatively attributed to the extreme reactivity of such compounds, including the reaction of an initially formed fluoride with the walls of the glass container to form a non-volatile product.^[a] Thus, although the synthesis of an astatine fluoride is thought to be possible, it may require a liquid halogen fluoride solvent, as has already been used for the characterization of radon fluorides.^[10]^[11]

In addition, there exist analogous molecules involving pseudohalogens, such as the cyanogen halides.

Tetratomic interhalogens[edit]

Chlorine trifluoride

Chlorine trifluoride (ClF₃) is a colourless gas that condenses to a green liquid, and freezes to a white solid. It is made by reacting chlorine with an excess of fluorine at 250 °C in a nickel tube. It reacts more violently than fluorine, often explosively. The molecule is planar and T-shaped. It is used in the manufacture of uranium hexafluoride.
Bromine trifluoride (BrF₃) is a yellow-green liquid that conducts electricity — it self-ionises to form [BrF₂]⁺ and [BrF₄]⁻. It reacts with many metals and metal oxides to form similar ionised entities; with some others it forms the metal fluoride plus free bromine and oxygen. It is used in organic chemistry as a fluorinating agent. It has the same molecular shape as chlorine trifluoride.
Iodine trifluoride (IF₃) is a yellow solid that decomposes above −28 °C. It can be synthesised from the elements, but care must be taken to avoid the formation of IF₅. F₂ attacks I₂ to yield IF₃ at −45 °C in CCl₃F. Alternatively, at low temperatures, the fluorination reaction

I₂ + 3 XeF₂ → 2 IF₃ + 3 Xe

can be used. Not much is known about iodine trifluoride as it is so unstable.

Iodine trichloride (ICl₃) forms lemon yellow crystals that melt under pressure to a brown liquid. It can be made from the elements at low temperature, or from iodine pentoxide and hydrogen chloride. It reacts with many metal chlorides to form tetrachloroiodides (ICl−
4), and hydrolyses in water. The molecule is a planar dimer (ICl₃)₂, with each iodine atom surrounded by four chlorine atoms.
Iodine tribromide (IBr₃) is a dark brown liquid.

Hexatomic interhalogens[edit]

Bromine pentafluoride

All stable hexatomic and octatomic interhalogens involve a heavier halogen combined with five or seven fluorine atoms. Unlike the other halogens, fluorine atoms have high electronegativity and small size which is able to stabilize them.

Chlorine pentafluoride (ClF₅) is a colourless gas, made by reacting chlorine trifluoride with fluorine at high temperatures and high pressures. It reacts violently with water and most metals and nonmetals.
Bromine pentafluoride (BrF₅) is a colourless fuming liquid, made by reacting bromine trifluoride with fluorine at 200 °C. It is physically stable, but reacts violently with water and most metals and nonmetals.
Iodine pentafluoride (IF₅) is a colourless liquid, made by reacting iodine pentoxide with fluorine, or iodine with silver(II) fluoride. It is highly reactive, even slowly with glass. It reacts with water to form hydrofluoric acid and with fluorine gas to form iodine heptafluoride. The molecule has the form of a tetragonal pyramid.
Octatomic interhalogens[edit]
Iodine heptafluoride
- Iodine heptafluoride (IF₇) is a colourless gas and a strong fluorinating agent. It is made by reacting iodine pentafluoride with fluorine gas. The molecule is a pentagonal bipyramid. This compound is the only known interhalogen compound where the larger atom is carrying seven of the smaller atoms.
- All attempts to synthesize bromine or chlorine heptafluoride have met with failure; instead, bromine pentafluoride or chlorine pentafluoride is produced, along with fluorine gas.

Properties[edit]

Typically, interhalogen bonds are more reactive than diatomic halogen bonds—because interhalogen bonds are weaker than diatomic halogen bonds, except for F₂. If interhalogens are exposed to water, they convert to halide and oxyhalide ions. With BrF₅, this reaction can be explosive. If interhalogens are exposed to silicon dioxide, or metal oxides, then silicon or metal respectively bond with one of the types of halogen, leaving free diatomic halogens and diatomic oxygen. Most interhalogens are halogen fluorides, and all but three (IBr, AtBr, and AtI) of the remainder are halogen chlorides. Chlorine and bromine can each bond to five fluorine atoms, and iodine can bond to seven. AX and AX₃ interhalogens can form between two halogens whose electronegativities are relatively close to one another. When interhalogens are exposed to metals, they react to form metal halides of the constituent halogens. The oxidation power of an interhalogen increases with the number of halogens attached to the central atom of the interhalogen, as well as with the decreasing size of the central atom of the compound. Interhalogens containing fluorine are more likely to be volatile than interhalogens containing heavier halogens.^[1]

Interhalogens with one or three halogens bonded to a central atom are formed by two elements whose electronegativities are not far apart. Interhalogens with five or seven halogens bonded to a central atom are formed by two elements whose sizes are very different. The number of smaller halogens that can bond to a large central halogen is guided by the ratio of the atomic radius of the larger halogen over the atomic radius of the smaller halogen. A number of interhalogens, such as IF₇, react with all metals except for those in the platinum group. IF₇, unlike interhalogens in the XY₅ series, does not react with the fluorides of the alkali metals.^[1]

ClF₃ is the most reactive of the XY₃ interhalogens. ICl₃ is the least reactive. BrF₃ has the highest thermal stability of the interhalogens with four atoms. ICl₃ has the lowest. Chlorine trifluoride has a boiling point of −12 °C. Bromine trifluoride has a boiling point of 127 °C and is a liquid at room temperature. Iodine trichloride melts at 101 °C.^[1]

Most interhalogens are covalent gases. Some interhalogens, especially those containing bromine, are liquids, and most iodine-containing interhalogens are solids. Most of the interhalogens composed of lighter halogens are fairly colorless, but the interhalogens containing heavier halogens are deeper in color due to their higher molecular weight. In this respect, the interhalogens are similar to the halogens. The greater the difference between the electronegativities of the two halogens in an interhalogen, the higher the boiling point of the interhalogen. All interhalogens are diamagnetic. The bond length of interhalogens in the XY series increases with the size of the constituent halogens. For instance, ClF has a bond length of 1.628 Å, and IBr has a bond length of 2.47 Å.^[1]

Production[edit]

It is possible to produce larger interhalogens, such as ClF₃, by exposing smaller interhalogens, such as ClF, to pure diatomic halogens, such as F₂. This method of production is especially useful for generating halogen fluorides. At temperatures of 250 to 300 °C, this type of production method can also convert larger interhalogens into smaller ones. It is also possible to produce interhalogens by combining two pure halogens at various conditions. This method can generate any interhalogen save for IF₇.^[1]

Smaller interhalogens, such as ClF, can form by direct reaction with pure halogens. For instance, F₂ reacts with Cl₂ at 250 °C to form two molecules of ClF. Br₂ reacts with diatomic fluorine in the same way, but at 60 °C. I₂ reacts with diatomic fluorine at only 35 °C. ClF and BrF can both be produced by the reaction of a larger interhalogen, such as ClF₃ or BrF₃ and a diatomic molecule of the element lower in the periodic table. Among the hexatomic interhalogens, IF₅ has a higher boiling point (97 °C) than BrF₅ (40.5 °C), although both compounds are liquids at room temperature. The interhalogen IF₇ can be formed by reacting palladium iodide with fluorine.^[1]

Notes[edit]

^ An initial attempt to fluoridate astatine using chlorine trifluoride resulted in formation of a product which became stuck to the glass. Chlorine monofluoride, chlorine, and tetrafluorosilane were formed. The authors called the effect "puzzling", admitting they had expected formation of a volatile fluoride.^[7] Ten years later, the compound was predicted to be non-volatile, out of line with the other halogens but similar to radon difluoride;^[8] by this time, the latter had been shown to be ionic.^[9]

https://en.wikipedia.org/wiki/Interhalogen#Hexatomic_interhalogens

Fulminic acid is an acid with the formula HCNO, more specifically H–C≡N⁺–O⁻. It is an isomer of isocyanic acid H–N=C=O and of its elusive tautomer cyanic acid H–O–C≡N, and also of isofulminic acid H–O–N⁺≡C⁻.^[1]

Fulminate is the anion [C⁻≡N⁺–O⁻] or any of its salts. For historical reasons, the fulminate functional group is understood to be –O–N⁺≡C⁻ as in isofulminic acid;^[2] whereas the group –C≡N⁺O⁻ is called nitrile oxide.

History[edit]

This chemical was known since the early 1800s through its salts and via the products of reactions in which it was proposed to exist,^[3] but the acid itself was not detected until 1966.^[1]

Structure[edit]

Fulminic acid was long believed to have a structure of H–O–N⁺≡C⁻. It wasn't until the 1966 isolation and analysis of a pure sample of fulminic acid that this structural idea was conclusively disproven.^[3] The chemical that actually has that structure, isofulminic acid (a tautomer of the actual fulminic acid structure) was eventually detected in 1988.^[3]

The structure of the molecule has been determined by microwave spectroscopy with the following bond-lengths - C-H: 1.027(1)Å, C-N: 1.161(15)Å, N-O: 1.207(15)Å.^[4]

Synthesis[edit]

A convenient synthesis involves flash pyrolysis of certain oximes. In contrast to earlier syntheses, this method avoids the use of highly explosive metal fulminates.^[5]

https://en.wikipedia.org/wiki/Fulminic_acid

Flash vacuum pyrolysis (FVP) is a technique in organic synthesis. It entails heating a precursor molecule intensely and briefly. Two key parameters are the temperature and duration (or residence time), which are adjusted to optimize yield, conversion, and avoidance of intractable products.^[1] Often the experiment entails volatilizing a precursor, which is drawn through a "hot zone" followed by rapid condensation. The apparatus typically is conducted under dynamic vacuum. The hot zone must impart heat to the gaseous molecules, so it is generally packed with solids to induce gas-solid collisions. The packing material is generally chemically inert, such as quartz.^[2] The precursor (i) volatilizes with gentle heating and under vacuum, (ii) the precursor fragments or rearranges in the hot zone, and finally (iii) the products are collected by rapid cooling. Rapid post-reaction cooling and the dilution inherent in gases both suppress bimolecular degradation pathways.

https://en.wikipedia.org/wiki/Flash_vacuum_pyrolysis

09-08-2021-1856 - fusion gene hybrid gene formed from two previously independent genes. It can occur as a result of translocation, interstitial deletion, or chromosomal inversion
A fusion gene is a hybrid gene formed from two previously independent genes. It can occur as a result of translocation, interstitial deletion, or chromosomal inversion. Fusion genes have been found to be prevalent in all main types of human neoplasia.[1] The identification of these fusion genes play a prominent role in being a diagnostic and prognostic marker.[2] 

Showing posts sorted by relevance for query magnetogenetics. Sort by date Show all posts
Sunday, April 10, 202204-10-2022-0739 - neurotrop vir neurotrophic factor NTF

Magnetogenetics refers to a biological technique that involves the use of magnetic fields to remotely control cell activity.

In most cases, magnetic stimulation is transformed into either force (magneto-mechanical genetics) or heat (magneto-thermal genetics), which depends on the applied magnetic field. Therefore, cells are usually genetically modified to express ion channels that are either mechanically or thermally gated. As such, magnetogenetics is a cellular modulation method that uses a combination of techniques from magnetism and genetics to control activities of individual cells in living tissue – even within freely moving animals. This technique is comparable to optogenetics, which is the manipulation of cell behavior using light. In magnetogenetics, magnetic stimulation is used instead of light, a characteristic that allows for a less invasive, less toxic, and wireless modulation of cell activity.

Cell activity control is achieved using magnetic compounds such as ferritin or magnetic nanoparticles. These compounds are designed to link to the ion channels that are genetically expressed on specific cells. Control of activity is thus restricted to genetically pre-defined cells and performed in a spatiotemporal-specific manner by magnetic stimulation.

https://en.wikipedia.org/wiki/Magnetogenetics

https://en.wikipedia.org/wiki/Optogenetics

https://en.wikipedia.org/wiki/Optogenetic_methods_to_record_cellular_activity

09-18-2021-0754 - ferrite core Magnetic-core memory 
09-18-2021-0754 - ferrite core Magnetic-core memory 
 In electronics, a ferrite core is a type of magnetic core made of ferrite on which the windings of electric transformers and other wound components such as inductors are formed. It is used for its properties of high magnetic permeability coupled with low electrical conductivity (which helps prevent eddy currents). Because of their comparatively low losses at high frequencies, they are extensively used in the cores of RF transformers and inductors in applications such as switched-mode power supplies, and ferrite loopstick antennas for AM radio receivers.
Ferrites are ceramic compounds of the transition metals with oxygen, which are ferrimagnetic but nonconductive. Ferrites that are used in transformer or electromagnetic cores contain iron oxides combined with nickel, zinc, and/or manganese compounds. They have a low coercivity and are called "soft ferrites" to distinguish them from "hard ferrites", which have a high coercivity and are used to make ferrite magnets. The low coercivity means the material's magnetization can easily reverse direction while dissipating very little energy (hysteresis losses), at the same time the material's high resistivity prevents eddy currents in the core, another source of energy loss. The most common soft ferrites are: 
Manganese-zinc ferrite (MnZn, with the formula MnaZn(1−a)Fe2O4). MnZn have higher permeability and saturation levels than NiZn.
Nickel-zinc ferrite (NiZn, with the formula NiaZn(1−a)Fe2O4). NiZn ferrites exhibit higher resistivity than MnZn, and are therefore more suitable for frequencies above 1 MHz.
For applications below 5 MHz, MnZn ferrites are used; above that, NiZn is the usual choice. The exception is with common mode inductors, where the threshold of choice is at 70 MHz.[1]
As any given blend has a trade off of maximum usable frequency, versus a higher mu value, within each of these sub-groups manufacturers produce a wide range materials for different applications blended to give either a high initial (low frequency) inductance, or lower inductance and higher maximum frequency, or for interference suppression ferrites, a very wide frequency range, but often with a very high loss factor (low Q).
It is important to select the right material for the application, as the correct ferrite for a 100 kHz switching supply (high inductance, low loss, low frequency) is quite different from that for an RF transformer or ferrite rod antenna, (high frequency, low loss, but lower inductance), and different again from a suppression ferrite (high loss, broadband)
https://en.wikipedia.org/wiki/Ferrite_core

Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core.
Core memory uses toroids (rings) of a hard magnetic material (usually a semi-hard ferrite) as transformer cores, where each wire threaded through the core serves as a transformer winding. Three or four wires pass through each core. Magnetic hysteresis allows each of the cores to "remember", or store a state.
Each core stores one bit of information. A core can be magnetized in either the clockwise or counter-clockwise direction. The value of the bit stored in a core is zero or one according to the direction of that core's magnetization. Electric current pulses in some of the wires through a core allow the direction of the magnetization in that core to be set in either direction, thus storing a one or a zero. Another wire through each core, the sense wire, is used to detect whether the core changed state.
The process of reading the core causes the core to be reset to a zero, thus erasing it. This is called destructive readout. When not being read or written, the cores maintain the last value they had, even if the power is turned off. Therefore they are a type of non-volatile memory.
Using smaller cores and wires, the memory density of core slowly increased, and by the late 1960s a density of about 32 kilobits per cubic foot (about 0.9 kilobits per litre) was typical. However, reaching this density required extremely careful manufacture, which was almost always carried out by hand in spite of repeated major efforts to automate the process. The cost declined over this period from about $1 per bit to about 1 cent per bit. The introduction of the first semiconductor memory chips in the late 1960s, which initially created static random-access memory (SRAM), began to erode the market for core memory. The first successful dynamic random-access memory (DRAM), the Intel 1103, followed in 1970. Its availability in quantity at 1 cent per bit marked the beginning of the end for core memory.[1]
Improvements in semiconductor manufacturing led to rapid increases in storage capacity and decreases in price per kilobyte, while the costs and specs of core memory changed little. Core memory was driven from the market gradually between 1973 and 1978.
Depending on how it was wired, core memory could be exceptionally reliable. Read-only core rope memory, for example, was used on the mission-critical Apollo Guidance Computer essential to NASA's successful Moon landings.
Although core memory is obsolete, computer memory is still sometimes called "core" even though it is made of semiconductors, particularly by people who had worked with machines having actual core memory. The files that result from saving the entire contents of memory to disk for inspection, which is nowadays commonly performed automatically when a major error occurs in a computer program, are still called "core dumps".
https://en.wikipedia.org/wiki/Magnetic-core_memory

https://en.wikipedia.org/wiki/Prussian_blue
https://en.wikipedia.org/wiki/Sodium_ferrocyanide

Core rope memory is a form of read-only memory (ROM) for computers, first used in the 1960s by early NASA Mars space probes and then in the Apollo Guidance Computer (AGC)^[1] and programmed by the Massachusetts Institute of Technology (MIT) Instrumentation Lab and built by Raytheon.

Software written by MIT programmers was woven into core rope memory by female workers in factories. Some programmers nicknamed the finished product LOL memory, for Little Old Lady memory.^[2]

https://en.wikipedia.org/wiki/Core_rope_memory

Reversal[edit]

Magnetization reversal, also known as switching, refers to the process that leads to a 180° (arc) re-orientation of the magnetization vector with respect to its initial direction, from one stable orientation to the opposite one. Technologically, this is one of the most important processes in magnetism that is linked to the magnetic data storage process such as used in modern hard disk drives.^[5] As it is known today, there are only a few possible ways to reverse the magnetization of a metallic magnet:

an applied magnetic field^[5]
spin injection via a beam of particles with spin^[5]
magnetization reversal by circularly polarized light;^[6] i.e., incident electromagnetic radiation that is circularly polarized

https://en.wikipedia.org/wiki/Magnetization

https://en.wikipedia.org/wiki/Spinor

Magnetostatics is the study of magnetic fields in systems where the currents are steady (not changing with time). It is the magnetic analogue of electrostatics, where the charges are stationary. The magnetization need not be static; the equations of magnetostatics can be used to predict fast magnetic switching events that occur on time scales of nanoseconds or less.^[1] Magnetostatics is even a good approximation when the currents are not static — as long as the currents do not alternate rapidly. Magnetostatics is widely used in applications of micromagnetics such as models of magnetic storage devices as in computer memory.

https://en.wikipedia.org/wiki/Magnetostatics

In physics, the magnetomotive force (mmf) is a quantity appearing in the equation for the magnetic flux in a magnetic circuit, often called Ohm's law for magnetic circuits.^[1] It is the property of certain substances or phenomena that give rise to magnetic fields:

{\mathcal {F}}=\Phi {\mathcal {R}},

where

Φ

is the magnetic flux and

{\mathcal {R}}

is the reluctance of the circuit. It can be seen that the magnetomotive force plays a role in this equation analogous to the voltage

V

in Ohm's law:

V = IR

, since it is the cause of magnetic flux in a magnetic circuit:^[2]

${\mathcal {F}}=NI$
where $N$ is the number of turns in the coil and $I$ is the electric current through the circuit.
${\mathcal {F}}=\Phi {\mathcal {R}}$
where $Φ$ is the magnetic flux and ${\mathcal {R}}$ is the magnetic reluctance
${\mathcal {F}}=HL$
where $H$ is the magnetizing force (the strength of the magnetizing field) and $L$ is the mean length of a solenoid or the circumference of a toroid.

https://en.wikipedia.org/wiki/Magnetomotive_force

In electromagnetism, permeability is the measure of magnetization that a material obtains in response to an applied magnetic field. Permeability is typically represented by the (italicized) Greek letter μ. The term was coined in September 1885 by Oliver Heaviside. The reciprocal of permeability is magnetic reluctivity.

In SI units, permeability is measured in henries per meter (H/m), or equivalently in newtons per ampere squared (N/A²). The permeability constant μ₀, also known as the magnetic constant or the permeability of free space, is the proportionality between magnetic induction and magnetizing force when forming a magnetic field in a classical vacuum.

A closely related property of materials is magnetic susceptibility, which is a dimensionless proportionality factor that indicates the degree of magnetization of a material in response to an applied magnetic field.

https://en.wikipedia.org/wiki/Permeability_(electromagnetism)

Spinodal decomposition is a mechanism by which a single thermodynamic phase spontaneously (i.e., without nucleation) separates into two phases.^[1] Decomposition occurs when there is no thermodynamic barrier to phase separation. As a result, phase separation via decomposition does not require the nucleation events resulting from thermodynamic fluctuations which normally trigger phase separation.

Spinodal decomposition is observed, for example, when mixtures of metals or polymers separate into two co-existing phases, each rich in one species and poor in the other.^[2] When the two phases emerge in approximately equal proportion (each occupying about the same volume or area), they form characteristic intertwined structures that gradually coarsen (see animation). The dynamics of spinodal decomposition are commonly modeled using the Cahn–Hilliard equation.

Spinodal decomposition is fundamentally different from nucleation and growth. When there is a nucleation barrier to the formation of a second phase, the system takes time to overcome that barrier. As there is no barrier (by definition) to spinodal decomposition, some fluctuations (in the order parameter that characterizes the phase) start growing instantly. Furthermore, in spinodal decomposition the two distinct phases start growing in any location uniformly throughout the volume, whereas a nucleated phase change begins at a discrete number of points.

Spinodal decomposition occurs when a homogenous phase becomes thermodynamically unstable. An unstable phase lies at a maximum in free energy. In contrast, nucleation and growth occurs when a homogenous phase becomes metastable. That is, another biphasic system becomes lower in free energy but, the homogenous phase remains at a local minimum in free energy, and so is resistant to small fluctuations. J. Willard Gibbs described two criteria for a metastable phase: that it must remain stable against a small change over a large area.^[3]

Microstructural evolution under the Cahn–Hilliard equation, demonstrating distinctive coarsening and phase separation.

In the early 1940s, Bradley reported the observation of sidebands around the Bragg peaks of the X-ray diffraction pattern from a Cu-Ni-Fe alloy that had been quenched and then annealed inside the miscibility gap. Further observations on the same alloy were made by Daniel and Lipson, who demonstrated that the sidebands could be explained by a periodic modulation of composition in the <100> directions. From the spacing of the sidebands, they were able to determine the wavelength of the modulation, which was of the order of 100 angstroms.

To reach the spinodal region of the phase diagram, a transition must take the material through the binodal region or the critical point. Often phase separation will occur via nucleation during this transition, and spinodal decomposition will not be observed. To observe spinodal decomposition, a very fast transition, often called a quench, is required to move from the stable to the spinodal unstable region of the phase diagram.

In some systems, ordering of the material leads to a compositional instability and this is known as a conditional spinodal, e.g. in the feldspars.^[15]^[16]^[17]^[18]^[19]

Spinodal Architected Materials[edit]

Example design of a spinodal architected material.

Spinodal phase decomposition has been used to generate architected materials by interpreting one phase as solid, and the other phase as void. These spinodal architected materials present interesting mechanical properties, such as high energy absorption,^[26]insensitivity to imperfections,^[27] and high stiffness-to-weight ratio.^[28] Furthermore, by controlling the phase separation, i.e. controlling the proportion of materials, and/or imposing preferential directions in the decompositions, one can control the density, and preferential directions effectively tuning the strength, weight, and anisotropy of the resulting architected material.^[29] Another interesting property of spinodal materials is the capability of seamlessly transition between different classes, orientations, and densities,^[29] thereby enabling manufacturing of effectively multi-material structures.^[30]

References[edit]

^ Binder, K (1987-07-01). "Theory of first-order phase transitions". Reports on Progress in Physics. 50 (7): 783–859. doi:10.1088/0034-4885/50/7/001. ISSN 0034-4885.
^ Gennes, Pierre-Gilles de. (1979). Scaling concepts in polymer physics. Ithaca, N.Y.: Cornell University Press. ISBN 0-8014-1203-X. OCLC 4494721.
^ Gibbs, J.W., Scientific Papers of J Willard Gibbs, 2 vols. Bumstead, H. A., and Van Name, R. G., eds. (Dover, New York, 1961) ISBN 0-918024-77-3
^ Hillert, M., A Theory of Nucleation for Solid Metallic Solutions, Sc. D. Thesis (MIT, 1955)
^ Hillert, M (1961). "A solid-solution model for inhomogeneous systems". Acta Metallurgica. Elsevier BV. 9 (6): 525–535. doi:10.1016/0001-6160(61)90155-9. ISSN 0001-6160.
^ Cahn, John W (1961). "On spinodal decomposition". Acta Metallurgica. Elsevier BV. 9 (9): 795–801. doi:10.1016/0001-6160(61)90182-1. ISSN 0001-6160.
^ Cahn, John W (1962). "On spinodal decomposition in cubic crystals". Acta Metallurgica. Elsevier BV. 10 (3): 179–183. doi:10.1016/0001-6160(62)90114-1. ISSN 0001-6160.
^ Cahn, John W (1962). "Coherent fluctuations and nucleation in isotropic solids". Acta Metallurgica. Elsevier BV. 10 (10): 907–913. doi:10.1016/0001-6160(62)90140-2. ISSN 0001-6160.
^ Cahn, John W.; Hilliard, John E. (1958). "Free Energy of a Nonuniform System. I. Interfacial Free Energy". The Journal of Chemical Physics. AIP Publishing. 28 (2): 258–267. Bibcode:1958JChPh..28..258C. doi:10.1063/1.1744102. ISSN 0021-9606.
^ Jump up to: ^a ^b Bray, A. J. (2002-03-01). "Theory of phase-ordering kinetics". Advances in Physics. 51 (2): 481–587. arXiv:cond-mat/9501089. Bibcode:2002AdPhy..51..481B. doi:10.1080/00018730110117433. ISSN 0001-8732. S2CID 218646292.
^ Jump up to: ^a ^b Hilliard, J.E., Spinodal Decomposition, in Phase Transformations p. 497 (American Society of Metals, Metals Park, 1970)
^ Bray, A. J. (1994). "Theory of phase ordering kinetics". Physica A: Statistical Mechanics and Its Applications. 194 (1): 41–52. arXiv:cond-mat/9501089. doi:10.1016/0378-4371(93)90338-5. ISSN 0378-4371.
^ Jump up to: ^a ^b ^c Cahn, J.W., Spinodal Decomposition, 1967 Institute of Metals Lecture, Trans. Met. Soc. AIME, Vol. 242, p. 168 (1968)
^ Jones, Richard A. L. (2004) [2002]. Soft Condensed Matter. Oxford University Press. p. 33. ISBN 978-0-19-850589-1. Retrieved 2007-10-22.
^ Cook, H.E (1973). "A lattice model of structural and dislocation transformations". Acta Metallurgica. Elsevier BV. 21 (10): 1431–1444. doi:10.1016/0001-6160(73)90092-8. ISSN 0001-6160.
^ Cook, H.E (1973). "On the nature of the omega transformation". Acta Metallurgica. Elsevier BV. 21 (10): 1445–1449. doi:10.1016/0001-6160(73)90093-x. ISSN 0001-6160.
^ Cook, H.E (1975). "On first-order structural phase transitions—I. General considerations of pre-transition and nucleation phenomena". Acta Metallurgica. Elsevier BV. 23 (9): 1027–1039. doi:10.1016/0001-6160(75)90107-8. ISSN 0001-6160.
^ Suzuki, T . and Wuttig, M., Analogy between spinodal decomposition and martensitic transformation, Acta Met., Vol. 23, p.1069 (1975)
^ Carpenter, M. A. (1981). "A "conditional spinodal" within the peristerite miscibility gap of plagioclase feldspars" (PDF). Journal of the American Mineralogist. 66: 553–560.
^ de Fontaine, D (1969). "An approximate criterion for the loss of coherency in modulated structures". Acta Metallurgica. Elsevier BV. 17 (4): 477–482. doi:10.1016/0001-6160(69)90029-7. ISSN 0001-6160.
^ Cook, H.E; De Fontaine, D; Hilliard, J.e (1969). "A model for diffusion on cubic lattices and its application to the early stages of ordering". Acta Metallurgica. Elsevier BV. 17 (6): 765–773. doi:10.1016/0001-6160(69)90083-2. ISSN 0001-6160.
^ Cook, H.E; de Fontaine, D (1969). "On the elastic free energy of solid solutions—I. Microscopic theory". Acta Metallurgica. Elsevier BV. 17 (7): 915–924. doi:10.1016/0001-6160(69)90112-6. ISSN 0001-6160.
^ De Fontaine, D. (1970). "Mechanical instabilities in the b.c.c. lattice and the beta to omega phase transformation". Acta Metallurgica. Elsevier BV. 18 (2): 275–279. doi:10.1016/0001-6160(70)90035-0. ISSN 0001-6160.
^ Cook, H.E.; De Fontaine, D. (1971). "On the elastic free energy of solid solutions—II. Influence of the effective modulus on precipitation from solution and the order-disorder reaction". Acta Metallurgica. Elsevier BV. 19 (7): 607–616. doi:10.1016/0001-6160(71)90013-7. ISSN 0001-6160.
^ De Fontaine, D; Paton, N.E; Williams, J.C (1971). "The omega phase transformation in titanium alloys as an example of displacement controlled reactions". Acta Metallurgica. Elsevier BV. 19 (11): 1153–1162. doi:10.1016/0001-6160(71)90047-2. ISSN 0001-6160.
^ Guell Izard, Anna; Bauer, Jens; Crook, Cameron; Turlo, Vladyslav; Valdevit, Lorenzo (November 2019). "Ultrahigh Energy Absorption Multifunctional Spinodal Nanoarchitectures". Small. 15 (45): 1903834. doi:10.1002/smll.201903834.
^ Hsieh, Meng-Ting; Endo, Bianca; Zhang, Yunfei; Bauer, Jens; Valdevit, Lorenzo (1 April 2019). "The mechanical response of cellular materials with spinodal topologies". Journal of the Mechanics and Physics of Solids. 125: 401–419. doi:10.1016/j.jmps.2019.01.002.
^ Zheng, Li; Kumar, Siddhant; Kochmann, Dennis M. (September 2021). "Data-driven topology optimization of spinodoid metamaterials with seamlessly tunable anisotropy". Computer Methods in Applied Mechanics and Engineering. 383: 113894. doi:10.1016/j.cma.2021.113894.
^ Jump up to: ^a ^b Kumar, Siddhant; Tan, Stephanie; Zheng, Li; Kochmann, Dennis M. (December 2020). "Inverse-designed spinodoid metamaterials". npj Computational Materials. 6 (1): 73. doi:10.1038/s41524-020-0341-6.
^ Senhora, Fernando V.; Sanders, Emily D.; Paulino, Glaucio H. (27 April 2022). "Optimally‐Tailored Spinodal Architected Materials for Multiscale Design and Manufacturing". Advanced Materials: 2109304. doi:10.1002/adma.202109304. PMID 35297113.

Nikiya Anton Bettey 2021

Blog Archive