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Endoreduplication (also referred to as endoreplication or endocycling) is replication of the nuclear genome in the absence of mitosis, which leads to elevated nuclear gene content and polyploidy. Endoreplication can be understood simply as a variant form of the mitotic cell cycle (G1-S-G2-M) in which mitosis is circumvented entirely, due to modulation of cyclin-dependent kinase (CDK) activity. Examples of endoreplication characterized in arthropod, mammalian, and plant species suggest that it is a universal developmental mechanism responsible for the differentiation and morphogenesis of cell types that fulfill an array of biological functions | https://huggingface.co/datasets/fmars/wiki_stem |
Fission, in biology, is the division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original. The object experiencing fission is usually a cell, but the term may also refer to how organisms, bodies, populations, or species split into discrete parts. The fission may be binary fission, in which a single organism produces two parts, or multiple fission, in which a single entity produces multiple parts | https://huggingface.co/datasets/fmars/wiki_stem |
The G0 phase describes a cellular state outside of the replicative cell cycle. Classically, cells were thought to enter G0 primarily due to environmental factors, like nutrient deprivation, that limited the resources necessary for proliferation. Thus it was thought of as a resting phase | https://huggingface.co/datasets/fmars/wiki_stem |
Cln1, Cln2, and Cln3 are cyclin proteins expressed in the G1-phase of the cell cycle of budding yeast. Like other cyclins, they function by binding and activating cyclin-dependent kinase. They are responsible for initiating entry into a new mitotic cell cycle at Start | https://huggingface.co/datasets/fmars/wiki_stem |
The G1 phase, gap 1 phase, or growth 1 phase, is the first of four phases of the cell cycle that takes place in eukaryotic cell division. In this part of interphase, the cell synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis. G1 phase ends when the cell moves into the S phase of interphase | https://huggingface.co/datasets/fmars/wiki_stem |
The G1/S transition is a stage in the cell cycle at the boundary between the G1 phase, in which the cell grows, and the S phase, during which DNA is replicated. It is governed by cell cycle checkpoints to ensure cell cycle integrity and the subsequent S phase can pause in response to improperly or partially replicated DNA. During this transition the cell makes decisions to become quiescent (enter G0), differentiate, make DNA repairs, or proliferate based on environmental cues and molecular signaling inputs | https://huggingface.co/datasets/fmars/wiki_stem |
G2 phase, Gap 2 phase, or Growth 2 phase, is the third subphase of interphase in the cell cycle directly preceding mitosis. It follows the successful completion of S phase, during which the cell’s DNA is replicated. G2 phase ends with the onset of prophase, the first phase of mitosis in which the cell’s chromatin condenses into chromosomes | https://huggingface.co/datasets/fmars/wiki_stem |
Hyperphosphorylation occurs when a biochemical with multiple phosphorylation sites is fully saturated. Hyperphosphorylation is one of the signaling mechanisms used by the cell to regulate mitosis. When these mechanisms fail, developmental problems or cancer are a likely outcome | https://huggingface.co/datasets/fmars/wiki_stem |
Induced cell cycle arrest is the use of a chemical or genetic manipulation to artificially halt progression through the cell cycle. Cellular processes like genome duplication and cell division stop. It can be temporary or permanent | https://huggingface.co/datasets/fmars/wiki_stem |
INK4 is a family of cyclin-dependent kinase inhibitors (CKIs). The members of this family (p16INK4a, p15INK4b, p18INK4c, p19INK4d) are inhibitors of CDK4 (hence their name INhibitors of CDK4), and of CDK6. The other family of CKIs, CIP/KIP proteins are capable of inhibiting all CDKs | https://huggingface.co/datasets/fmars/wiki_stem |
Antigen KI-67, also known as Ki-67, Ki-67 or MKI67 (Marker Of Proliferation Ki-67), is a protein that in humans is encoded by the MKI67 gene (antigen identified by monoclonal antibody Ki-67).
Function
Antigen KI-67 is a nuclear protein that is associated with cellular proliferation and ribosomal RNA transcription. Inactivation of antigen KI-67 leads to inhibition of ribosomal RNA synthesis, but does not significantly affect cell proliferation in vivo: Ki-67 mutant mice developed normally and cells lacking Ki-67 proliferated efficiently | https://huggingface.co/datasets/fmars/wiki_stem |
Mad1 is a non-essential protein which in yeast has a function in the spindle assembly checkpoint (SAC).
This checkpoint monitors chromosome attachment to spindle microtubules and prevents cells from starting anaphase until the spindle is built up. The name Mad refers to the observation that mutant cells are mitotic arrest deficient (MAD) during microtubule depolymerization | https://huggingface.co/datasets/fmars/wiki_stem |
Maturation-promoting factor (abbreviated MPF, also called mitosis-promoting factor or M-Phase-promoting factor) is the cyclin-Cdk complex that was discovered first in frog eggs. It stimulates the mitotic and meiotic phases of the cell cycle. MPF promotes the entrance into mitosis (the M phase) from the G2 phase by phosphorylating multiple proteins needed during mitosis | https://huggingface.co/datasets/fmars/wiki_stem |
mDia1 (also known as Dia1, Drf1 for Diaphanous-related formin-1, Diaph1, KIAA4062, p140mDia, mKIAA4062, or D18Wsu154e) is a member of the protein family called the formins and is a Rho effector. It is the mouse version of the diaphanous homolog 1 of Drosophila. mDia1 localizes to cells' mitotic spindle and midbody, plays a role in stress fiber and filopodia formation, phagocytosis, activation of serum response factor, formation of adherens junctions, and it can act as a transcription factor | https://huggingface.co/datasets/fmars/wiki_stem |
In cell biology, Meiomitosis is an aberrant cellular division pathway that combines normal mitosis pathways with ectopically expressed meiotic machinery resulting in genomic instability.
Description
Meiotic pathways are normally restricted to germ cells. Meiotic proteins drive double stranded DNA breaks, chiasma formation, sister chromatid adhesion and rearrange the spindle apparatus | https://huggingface.co/datasets/fmars/wiki_stem |
In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maintained. Therefore, mitosis is also known as equational division | https://huggingface.co/datasets/fmars/wiki_stem |
Multipolar spindles are spindle formations characteristic of cancer cells. Spindle formation is mostly conducted by the aster of the centrosome which it forms around itself. In a mitotic cell wherever two asters convene the formation of a spindle occurs | https://huggingface.co/datasets/fmars/wiki_stem |
NDR (nuclear dbf2-related) kinases, are an ancient and highly conserved subclass of AGC protein kinases that control diverse processes related to cell morphogenesis, proliferation, and mitotic events.
Function and medical relevance
Like most AGC kinases, the NDR kinase subclass is activated by phosphorylation of a conserved serine or threonine in an activation region C-terminal to the kinase catalytic domain. The NDR kinases are distinguished by an apparently functionally essential binding of MOB co-activator proteins that are also widely present in eukaryotes | https://huggingface.co/datasets/fmars/wiki_stem |
The Neuronal cell cycle represents the life cycle of the biological cell, its creation, reproduction and eventual death. The process by which cells divide into two daughter cells is called mitosis. Once these cells are formed they enter G1, the phase in which many of the proteins needed to replicate DNA are made | https://huggingface.co/datasets/fmars/wiki_stem |
Polo-like kinases (Plks) are regulatory serine/threonin kinases of the cell cycle involved in mitotic entry, mitotic exit, spindle formation, cytokinesis, and meiosis. Only one Plk is found in the genomes of the fly Drosophila melanogaster (Polo), budding yeast (Cdc5) and fission yeast (Plo1). Vertebrates and other animals, however, have many Plk family members including Plk1 (Xenopus Plx1), Plk2/Snk (Xenopus Plx2), Plk3/Prk/FnK (Xenopus Plx3), Plk4/Sak and Plk5 | https://huggingface.co/datasets/fmars/wiki_stem |
Preimplantation factor (PIF) is a peptide secreted by trophoblast cells prior to placenta formation in early embryonic development. Human embryos begin to express PIF at the 4-cell stage, with expression increasing by the morula stage and continuing to do so throughout the first trimester. Expression of preimplantation factor in the blastocyst was discovered as an early correlate of the viability of the eventual pregnancy | https://huggingface.co/datasets/fmars/wiki_stem |
The restriction point (R), also known as the Start or G1/S checkpoint, is a cell cycle checkpoint in the G1 phase of the animal cell cycle at which the cell becomes "committed" to the cell cycle, and after which extracellular signals are no longer required to stimulate proliferation. The defining biochemical feature of the restriction point is the activation of G1/S- and S-phase cyclin-CDK complexes, which in turn phosphorylate proteins that initiate DNA replication, centrosome duplication, and other early cell cycle events. It is one of three main cell cycle checkpoints, the other two being the G2-M DNA damage checkpoint and the spindle checkpoint | https://huggingface.co/datasets/fmars/wiki_stem |
Rho-associated protein kinase (ROCK) is a kinase belonging to the AGC (PKA/ PKG/PKC) family of serine-threonine specific protein kinases. It is involved mainly in regulating the shape and movement of cells by acting on the cytoskeleton.
ROCKs (ROCK1 and ROCK2) occur in mammals (human, rat, mouse, cow), zebrafish, Xenopus, invertebrates (C | https://huggingface.co/datasets/fmars/wiki_stem |
S phase (Synthesis Phase) is the phase of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Since accurate duplication of the genome is critical to successful cell division, the processes that occur during S-phase are tightly regulated and widely conserved.
Regulation
Entry into S-phase is controlled by the G1 restriction point (R), which commits cells to the remainder of the cell-cycle if there is adequate nutrients and growth signaling | https://huggingface.co/datasets/fmars/wiki_stem |
Introduction:
S-phase-promoting factor(SPF) is varying Cdk/cyclin complexes in eukaryotes that initiates the S-phase in the cell cycle. SPF is at its peak when the cell cycle is transiting from G1 phase to the S-phase. The SPF is at its lowest during the cell cycle once the cyclin subunits are used up, and broken down | https://huggingface.co/datasets/fmars/wiki_stem |
Salvage enzymes are enzymes, nucleoside kinases, required during cell division to "salvage" nucleotides, present in body fluids, for the manufacture of DNA. They catalyze the phosphorylation of nucleosides to nucleoside - 5'-phosphates, that are further phosphorylated to triphosphates, that can be built into the growing DNA chain. The salvage enzymes are synthesized during the G1 phase in anticipation of DNA synthesis | https://huggingface.co/datasets/fmars/wiki_stem |
Septins are a group of GTP-binding proteins expressed in all eukaryotic cells except plants. Different septins form protein complexes with each other. These complexes can further assemble into filaments, rings and gauzes | https://huggingface.co/datasets/fmars/wiki_stem |
Sic1, a protein, is a stoichiometric inhibitor of Cdk1-Clb (B-type cyclins) complexes in the budding yeast Saccharomyces cerevisiae. Because B-type cyclin-Cdk1 complexes are the drivers of S-phase initiation, Sic1 prevents premature S-phase entry. Multisite phosphorylation of Sic1 is thought to time Sic1 ubiquitination and destruction, and by extension, the timing of S-phase entry | https://huggingface.co/datasets/fmars/wiki_stem |
SMC complexes represent a large family of ATPases that participate in many aspects of higher-order chromosome organization and dynamics. SMC stands for Structural Maintenance of Chromosomes.
Classification
Eukaryotic SMCs
Eukaryotes have at least six SMC proteins in individual organisms, and they form three distinct heterodimers with specialized functions:
A pair of SMC1 and SMC3 constitutes the core subunits of the cohesin complexes involved in sister chromatid cohesion | https://huggingface.co/datasets/fmars/wiki_stem |
The spindle checkpoint, also known as the metaphase-to-anaphase transition, the spindle assembly checkpoint (SAC), the metaphase checkpoint, or the mitotic checkpoint, is a cell cycle checkpoint during mitosis or meiosis that prevents the separation of the duplicated chromosomes (anaphase) until each chromosome is properly attached to the spindle. To achieve proper segregation, the two kinetochores on the sister chromatids must be attached to opposite spindle poles (bipolar orientation). Only this pattern of attachment will ensure that each daughter cell receives one copy of the chromosome | https://huggingface.co/datasets/fmars/wiki_stem |
The Start checkpoint is a major cell cycle checkpoint in yeast. The Start checkpoint ensures irreversible cell-cycle entry even if conditions later become unfavorable. The physiological factors that control passage through the Start checkpoint include external nutrient concentrations, presence of mating factor/ pheromone, forms of stress, and size control | https://huggingface.co/datasets/fmars/wiki_stem |
Tissue growth is the process by which a tissue increases its size. In animals, tissue growth occurs during embryonic development, post-natal growth, and tissue regeneration. The fundamental cellular basis for tissue growth is the process of cell proliferation, which involves both cell growth and cell division occurring in parallel | https://huggingface.co/datasets/fmars/wiki_stem |
Wee1 is a nuclear kinase belonging to the Ser/Thr family of protein kinases in the fission yeast Schizosaccharomyces pombe (S. pombe). Wee1 has a molecular mass of 96 kDa and is a key regulator of cell cycle progression | https://huggingface.co/datasets/fmars/wiki_stem |
Xenopus egg extract is a lysate that is prepared by crushing the eggs of the African clawed frog Xenopus laevis. It offers a powerful cell-free (or in vitro) system for studying various cell biological processes, including cell cycle progression, nuclear transport, DNA replication and chromosome segregation. It is also called Xenopus egg cell-free system or Xenopus egg cell-free extract | https://huggingface.co/datasets/fmars/wiki_stem |
Cellular senescence is a phenomenon characterized by the cessation of cell division. In their experiments during the early 1960s, Leonard Hayflick and Paul Moorhead found that normal human fetal fibroblasts in culture reach a maximum of approximately 50 cell population doublings before becoming senescent. This process is known as "replicative senescence", or the Hayflick limit | https://huggingface.co/datasets/fmars/wiki_stem |
The cell cycle, or cell-division cycle, is the series of events that take place in a cell that causes it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called cell division.
In cells with nuclei (eukaryotes, i | https://huggingface.co/datasets/fmars/wiki_stem |
Cell damage (also known as cell injury) is a variety of changes of stress that a cell suffers due to external as well as internal environmental changes. Amongst other causes, this can be due to physical, chemical, infectious, biological, nutritional or immunological factors. Cell damage can be reversible or irreversible | https://huggingface.co/datasets/fmars/wiki_stem |
DNA-SCARS (short for DNA segments with chromatin alterations reinforcing senescence) are nuclear substructures with persistent DNA damage and DNA damage response proteins found in senescent cells. DNA-SCARS are associated with PML nuclear bodies and the accumulation of activated ATM, ATR, CHK2 and p53 proteins. DNA-SCARS lack most of the characteristics of transient, reversible DNA damage foci, such as single-stranded DNA, active DNA synthesis, and DNA repair proteins RPA and RAD51 | https://huggingface.co/datasets/fmars/wiki_stem |
Eat-me signals are molecules exposed on the surface of a cell to induce phagocytes to phagocytose (eat) that cell. Currently known eat-me signals include: phosphatidylserine, oxidized phospholipids, sugar residues (such as galactose), deoxyribonucleic acid (DNA), calreticulin, annexin A1, histones and pentraxin-3 (PTX3). The most well characterised eat-me signal is the phospholipid phosphatidylserine | https://huggingface.co/datasets/fmars/wiki_stem |
An immortalised cell line is a population of cells from a multicellular organism which would normally not proliferate indefinitely but, due to mutation, have evaded normal cellular senescence and instead can keep undergoing division. The cells can therefore be grown for prolonged periods in vitro. The mutations required for immortality can occur naturally or be intentionally induced for experimental purposes | https://huggingface.co/datasets/fmars/wiki_stem |
Jurkat cells are an immortalized line of human T lymphocyte cells that are used to study acute T cell leukemia, T cell signaling, and the expression of various chemokine receptors susceptible to viral entry, particularly HIV. Jurkat cells can produce interleukin 2, and are used in research involving the susceptibility of cancers to drugs and radiation.
History
The Jurkat cell line (originally called JM) was established in the mid-1970s from the peripheral blood of a 14-year-old boy with T cell leukemia | https://huggingface.co/datasets/fmars/wiki_stem |
Senescence-associated secretory phenotype (SASP) is a phenotype associated with senescent cells wherein those cells secrete high levels of inflammatory cytokines, immune modulators, growth factors, and proteases. SASP may also consist of exosomes and ectosomes containing enzymes, microRNA, DNA fragments, chemokines, and other bioactive factors. Soluble urokinase plasminogen activator surface receptor is part of SASP, and has been used to identify senescent cells for senolytic therapy | https://huggingface.co/datasets/fmars/wiki_stem |
In the field of genetics, a suicide gene is a gene that will cause a cell to kill itself through the process of apoptosis (programmed cell death). Activation of a suicide gene can cause death through a variety of pathways, but one important cellular "switch" to induce apoptosis is the p53 protein. Stimulation or introduction (through gene therapy) of suicide genes is a potential way of treating cancer or other proliferative diseases | https://huggingface.co/datasets/fmars/wiki_stem |
Telomeres, the caps on the ends of eukaryotic chromosomes, play critical roles in cellular aging and cancer. An important facet to how telomeres function in these roles is their involvement in cell cycle regulation.
Eukaryotic cells
Because eukaryotic chromosomes are linear and because DNA replication by DNA polymerase requires the presence of an RNA primer that is later degraded, eukaryotic cells face the end-replication problem | https://huggingface.co/datasets/fmars/wiki_stem |
Acute necrotizing ulcerative gingivitis (ANUG) is a common, non-contagious infection of the gums with sudden onset. The main features are painful, bleeding gums, and ulceration of inter-dental papillae (the sections of gum between adjacent teeth). This disease, along with necrotizing (ulcerative) periodontitis (NP or NUP) is classified as a necrotizing periodontal disease, one of the seven general types of gum disease caused by inflammation of the gums (periodontitis) | https://huggingface.co/datasets/fmars/wiki_stem |
Caseous necrosis or caseous degeneration () is a unique form of cell death in which the tissue maintains a cheese-like appearance. It is also a distinctive form of coagulative necrosis. The dead tissue appears as a soft and white proteinaceous dead cell mass | https://huggingface.co/datasets/fmars/wiki_stem |
A chronic wound is a wound that does not heal in an orderly set of stages and in a predictable amount of time the way most wounds do; wounds that do not heal within three months are often considered chronic.
Chronic wounds seem to be detained in one or more of the phases of wound healing. For example, chronic wounds often remain in the inflammatory stage for too long | https://huggingface.co/datasets/fmars/wiki_stem |
In quantum mechanics, a triplet state, or spin triplet, is the quantum state of an object such as an electron, atom, or molecule, having a quantum spin S = 1. It has three allowed values of the spin's projection along a given axis mS = −1, 0, or +1, giving the name "triplet".
Spin, in the context of quantum mechanics, is not a mechanical rotation but a more abstract concept that characterizes a particle's intrinsic angular momentum | https://huggingface.co/datasets/fmars/wiki_stem |
Triplet-triplet annihilation (TTA) is an energy transfer mechanism where two molecules in their triplet excited states interact to form a ground state molecule and an excited molecule in its singlet state. This mechanism is example of Dexter energy transfer mechanism. In triplet-triplet annihilation, one molecule transfers its excited state energy to the second molecule, resulting in the first molecule returning to its ground state and the second molecule being promoted to a higher excited singlet state | https://huggingface.co/datasets/fmars/wiki_stem |
Two dimensional correlation analysis is a mathematical technique that is used to study changes in measured signals. As mostly spectroscopic signals are discussed, sometime also two dimensional correlation spectroscopy is used and refers to the same technique.
In 2D correlation analysis, a sample is subjected to an external perturbation while all other parameters of the system are kept at the same value | https://huggingface.co/datasets/fmars/wiki_stem |
Ultraviolet–visible spectroscopy (UV–vis) can distinguish between enantiomers by showing a distinct Cotton effect for each isomer. UV–vis spectroscopy sees only chromophores, so other molecules must be prepared for analysis by chemical addition of a chromophore such as anthracene. Two methods are reported: the octant rule and the exciton chirality method | https://huggingface.co/datasets/fmars/wiki_stem |
Ultraviolet-visible (UV-Vis) absorption spectroelectrochemistry (SEC) is a multiresponse technique that analyzes the evolution of the absorption spectra in UV-Vis regions during an electrode process. This technique provides information from an electrochemical and spectroscopic point of view. In this way, it enables a better perception about the chemical system of interest | https://huggingface.co/datasets/fmars/wiki_stem |
The technique of vibrational analysis with scanning probe microscopy allows probing vibrational properties of materials at the submicrometer scale, and even of individual molecules. This is accomplished by integrating scanning probe microscopy (SPM) and vibrational spectroscopy (Raman scattering or/and Fourier transform infrared spectroscopy, FTIR). This combination allows for much higher spatial resolution than can be achieved with conventional Raman/FTIR instrumentation | https://huggingface.co/datasets/fmars/wiki_stem |
Vibronic spectroscopy is a branch of molecular spectroscopy concerned with vibronic transitions: the simultaneous changes in electronic and vibrational energy levels of a molecule due to the absorption or emission of a photon of the appropriate energy. In the gas phase, vibronic transitions are accompanied by changes in rotational energy also.
Vibronic spectra of diatomic molecules have been analysed in detail; emission spectra are more complicated than absorption spectra | https://huggingface.co/datasets/fmars/wiki_stem |
Video spectroscopy combines spectroscopic measurements with video technique. This technology has resulted from recent developments in hyperspectral imaging. A video capable imaging spectrometer can work like a camcorder and provide full frame spectral images in real-time that enables advanced (vehicle based) mobility and hand-held imaging spectroscopy | https://huggingface.co/datasets/fmars/wiki_stem |
A virtually imaged phased array (VIPA) is an angular dispersive device that, like a prism or a diffraction grating, splits light into its spectral components. It works almost independently of polarization. In contrast to prisms or regular diffraction gratings, it has a much higher angular dispersion but has a smaller free spectral range | https://huggingface.co/datasets/fmars/wiki_stem |
The Voigt profile (named after Woldemar Voigt) is a probability distribution given by a convolution of a Cauchy-Lorentz distribution and a Gaussian distribution. It is often used in analyzing data from spectroscopy or diffraction.
Definition
Without loss of generality, we can consider only centered profiles, which peak at zero | https://huggingface.co/datasets/fmars/wiki_stem |
The zero-phonon line and the phonon sideband jointly constitute the line shape of individual light absorbing and emitting molecules (chromophores) embedded into a transparent solid matrix. When the host matrix contains many chromophores, each will contribute a zero-phonon line and a phonon sideband to the absorption and emission spectra. The spectra originating from a collection of identical chromophores in a matrix is said to be inhomogeneously broadened because each chromophore is surrounded by a somewhat different matrix environment which modifies the energy required for an electronic transition | https://huggingface.co/datasets/fmars/wiki_stem |
Surface science is the study of physical and chemical phenomena that occur at the interface of two phases, including solid–liquid interfaces, solid–gas interfaces, solid–vacuum interfaces, and liquid–gas interfaces. It includes the fields of surface chemistry and surface physics. Some related practical applications are classed as surface engineering | https://huggingface.co/datasets/fmars/wiki_stem |
An adatom is an atom that lies on a crystal surface, and can be thought of as the opposite of a surface vacancy. This term is used in surface chemistry and epitaxy, when describing single atoms lying on surfaces and surface roughness. The word is a portmanteau of "adsorbed atom" | https://huggingface.co/datasets/fmars/wiki_stem |
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. This process differs from absorption, in which a fluid (the absorbate) is dissolved by or permeates a liquid or solid (the absorbent) | https://huggingface.co/datasets/fmars/wiki_stem |
An anti-graffiti coating is a coating that prevents graffiti paint from bonding to surfaces.
Cleaning graffiti off buildings costs billions of dollars annually. Many cities have started anti-graffiti programs but vandalism is still a problem | https://huggingface.co/datasets/fmars/wiki_stem |
Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube such as a straw, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces | https://huggingface.co/datasets/fmars/wiki_stem |
The captive bubble method is a method for measuring contact angle between a liquid and a solid, by using drop shape analysis. In this method, a bubble of air is injected beneath a solid, the surface of which is located in the liquid, instead of placing a drop on the solid as in the case of the sessile drop technique.
The method is particularly suitable for solids with high surface free energy on which liquids spread out | https://huggingface.co/datasets/fmars/wiki_stem |
Cassie's law, or the Cassie equation, describes the effective contact angle θc for a liquid on a chemically heterogeneous surface, i. e. the surface of a composite material consisting of different chemistries, that is non uniform throughout | https://huggingface.co/datasets/fmars/wiki_stem |
Desorption is the physical process where adsorbed atoms or molecules are released from a surface into the surrounding vacuum or fluid. This occurs when a molecule gains enough energy to overcome the activation barrier and the binding energy that keep it attached to the surface. Desorption is the reverse of the process of adsorption, which differs from absorption in that adsorption it refers to substances bound to the surface, rather than being absorbed into the bulk | https://huggingface.co/datasets/fmars/wiki_stem |
In fluid mechanics, dewetting is one of the processes that can occur at a solid–liquid, solid–solid or liquid–liquid interface. Generally, dewetting describes the process of retraction of a fluid from a non-wettable surface it was forced to cover. The opposite process—spreading of a liquid on a substrate—is called wetting | https://huggingface.co/datasets/fmars/wiki_stem |
In surface chemistry, disjoining pressure (symbol Πd) according to an IUPAC definition arises from an attractive interaction between two surfaces. For two flat and parallel surfaces, the value of the disjoining pressure (i. e | https://huggingface.co/datasets/fmars/wiki_stem |
In surface science, a double layer (DL, also called an electrical double layer, EDL) is a structure that appears on the surface of an object when it is exposed to a fluid. The object might be a solid particle, a gas bubble, a liquid droplet, or a porous body. The DL refers to two parallel layers of charge surrounding the object | https://huggingface.co/datasets/fmars/wiki_stem |
The du Noüy–Padday method is a minimized version of the du Noüy ring method replacing the large platinum ring with a thin rod that is used to measure equilibrium surface tension or dynamic surface tension at an air–liquid interface. In this method, the rod is oriented perpendicular to the interface, and the force exerted on it is measured. Based on the work of Padday, this method finds wide use in the preparation and monitoring of Langmuir–Blodgett films, ink & coating development, pharmaceutical screening, and academic research | https://huggingface.co/datasets/fmars/wiki_stem |
Electroviscous effects, in chemistry of colloids and surface chemistry, according to an IUPAC definition, are the effects of the particle surface charge on viscosity of a fluid.
Viscoelectric is an effect by which an electric field near a charged interface influences the structure of the surrounding fluid and affects the viscosity of the fluid. Kinematic viscosity of a fluid, η, can be expressed as a function of electric potential gradient (electric field),
E
→
{\textstyle {\vec {E}}}
, by an equation in the form:
where f is the viscoelectric coefficient of the fluid | https://huggingface.co/datasets/fmars/wiki_stem |
The Fowkes hypothesis (after F. M. Fowkes) is a first order approximation for surface energy | https://huggingface.co/datasets/fmars/wiki_stem |
Galling is a form of wear caused by adhesion between sliding surfaces. When a material galls, some of it is pulled with the contacting surface, especially if there is a large amount of force compressing the surfaces together. Galling is caused by a combination of friction and adhesion between the surfaces, followed by slipping and tearing of crystal structure beneath the surface | https://huggingface.co/datasets/fmars/wiki_stem |
The Gibbs–Thomson effect, in common physics usage, refers to variations in vapor pressure or chemical potential across a curved surface or interface. The existence of a positive interfacial energy will increase the energy required to form small particles with high curvature, and these particles will exhibit an increased vapor pressure. See Ostwald–Freundlich equation | https://huggingface.co/datasets/fmars/wiki_stem |
A Guinier–Preston zone, or GP-zone, is a fine-scale metallurgical phenomenon, involving early stage precipitation. GP-zones are associated with the phenomenon of age hardening, whereby room-temperature reactions continue to occur within a material through time, resulting in changing physical properties. In particular, this occurs in several aluminium series, such as the 6000 and 7000 series alloys | https://huggingface.co/datasets/fmars/wiki_stem |
Helium-3 surface spin echo (HeSE) is an inelastic scattering technique in surface science that has been used to measure microscopic dynamics at well-defined surfaces in ultra-high vacuum. The information available from HeSE complements and extends that available from other inelastic scattering techniques such as neutron spin echo and traditional helium-4 atom scattering (HAS).
Principles
The experimental principles of the HeSE experiment are analogous to those of neutron spin echo, differing in details such as the nature of the probe/sample interactions that give rise to scattering | https://huggingface.co/datasets/fmars/wiki_stem |
Heterogeneous gold catalysis refers to the use of elemental gold as a heterogeneous catalyst. As in most heterogeneous catalysis, the metal is typically supported on metal oxide. Furthermore, as seen in other heterogeneous catalysts, activity increases with a decreasing diameter of supported gold clusters | https://huggingface.co/datasets/fmars/wiki_stem |
The behavior of quantum dots (QDs) in solution and their interaction with other surfaces is of great importance to biological and industrial applications, such as optical displays, animal tagging, anti-counterfeiting dyes and paints, chemical sensing, and fluorescent tagging. However, unmodified quantum dots tend to be hydrophobic, which precludes their use in stable, water-based colloids. Furthermore, because the ratio of surface area to volume in a quantum dot is much higher than for larger particles, the thermodynamic free energy associated with dangling bonds on the surface is sufficient to impede the quantum confinement of excitons | https://huggingface.co/datasets/fmars/wiki_stem |
Hydrosilylation, also called catalytic hydrosilation, describes the addition of Si-H bonds across unsaturated bonds. Ordinarily the reaction is conducted catalytically and usually the substrates are unsaturated organic compounds. Alkenes and alkynes give alkyl and vinyl silanes; aldehydes and ketones give silyl ethers | https://huggingface.co/datasets/fmars/wiki_stem |
An ideal solid surface is flat, rigid, perfectly smooth, and chemically homogeneous, and has zero contact angle hysteresis. Zero hysteresis implies the advancing and receding contact angles are equal.
In other words, only one thermodynamically stable contact angle exists | https://huggingface.co/datasets/fmars/wiki_stem |
In the physical sciences, an interface is the boundary between two spatial regions occupied by different matter, or by matter in different physical states. The interface between matter and air, or matter and vacuum, is called a surface, and studied in surface science. In thermal equilibrium, the regions in contact are called phases, and the interface is called a phase boundary | https://huggingface.co/datasets/fmars/wiki_stem |
Interfacial rheology is a branch of rheology that studies the flow of matter at the interface between a gas and a liquid or at the interface between two immiscible liquids. The measurement is done while having surfactants, nanoparticles or other surface active compounds present at the interface. Unlike in bulk rheology, the deformation of the bulk phase is not of interest in interfacial rheology and its effect is aimed to be minimized | https://huggingface.co/datasets/fmars/wiki_stem |
Inverse photoemission spectroscopy (IPES) is a surface science technique used to study the unoccupied electronic structure of surfaces, thin films, and adsorbates. A well-collimated beam of electrons of a well defined energy (< 20 eV) is directed at the sample. These electrons couple to high-lying unoccupied electronic states and decay to low-lying unoccupied states, with a subset of these transitions being radiative | https://huggingface.co/datasets/fmars/wiki_stem |
Köhler theory describes the process in which water vapor condenses and forms liquid cloud drops, and is based on equilibrium thermodynamics. It combines the Kelvin effect, which describes the change in saturation vapor pressure due to a curved surface, and Raoult's Law, which relates the saturation vapor pressure to the solute. It is an important process in the field of cloud physics | https://huggingface.co/datasets/fmars/wiki_stem |
In petroleum engineering, Lak wettability index is a quantitative indicator to measure wettability of rocks from relative permeability data. This index is based on a combination of Craig's first rule. and modified Craig's second rule
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Liquid marbles are non-stick droplets (normally aqueous) wrapped by micro- or nano-metrically scaled hydrophobic, colloidal particles (Teflon, polyethylene, lycopodium powder, carbon black, etc. ); representing a platform for a diversity of chemical and biological applications. Liquid marbles are also found naturally; aphids convert honeydew droplets into marbles | https://huggingface.co/datasets/fmars/wiki_stem |
The lotus effect refers to self-cleaning properties that are a result of ultrahydrophobicity as exhibited by the leaves of Nelumbo, the lotus flower. Dirt particles are picked up by water droplets due to the micro- and nanoscopic architecture on the surface, which minimizes the droplet's adhesion to that surface. Ultrahydrophobicity and self-cleaning properties are also found in other plants, such as Tropaeolum (nasturtium), Opuntia (prickly pear), Alchemilla, cane, and also on the wings of certain insects | https://huggingface.co/datasets/fmars/wiki_stem |
A nanotextured surface (NTS) is a surface which is covered with nano-sized structures. Such surfaces have one dimension on the nanoscale, i. e | https://huggingface.co/datasets/fmars/wiki_stem |
A number of processes of surface growth in areas ranging from mechanics of growing gravitational bodies through propagating fronts of phase transitions, epitaxial growth of nanostructures and 3D printing, growth of plants, and cell mobility require non-Euclidean description because of incompatibility of boundary conditions and different mechanisms of developing stresses at interfaces. Indeed, these mechanisms result in the curving of initially flat elements of the body and changing separation between different elements of it (especially in the soft matter). Gradual accumulation of deformations under the influx of accumulating mass results in the memory-conscious grows of the body and makes strains the subject of long-range forces | https://huggingface.co/datasets/fmars/wiki_stem |
An overlayer is a layer of adatoms adsorbed onto a surface, for instance onto the surface of a single crystal.
On single crystals
Adsorbed species on single crystal surfaces are frequently found to exhibit long-range ordering; that is to say that the adsorbed species form a well-defined overlayer structure. Each particular structure may only exist over a limited coverage range of the adsorbate, and in some adsorbate/substrate systems a whole progression of adsorbate structure are formed as the surface coverage is gradually increased | https://huggingface.co/datasets/fmars/wiki_stem |
The oxhydroelectric effect consists in the generation of voltage and electric current in pure liquid water, without any electrolyte, upon exposure to electromagnetic radiation in the infrared range, after creating a physical (not chemical) asymmetry in liquid water e. g. thanks to a strongly hydrophile polymer, such as Nafion | https://huggingface.co/datasets/fmars/wiki_stem |
The surface chemistry of paper is responsible for many important paper properties, such as gloss, waterproofing, and printability. Many components are used in the paper-making process that affect the surface.
Pigment and dispersion medium
Coating components are subject to particle-particle, particle-solvent, and particle-polymer interactions | https://huggingface.co/datasets/fmars/wiki_stem |
Particle-induced X-ray emission or proton-induced X-ray emission (PIXE) is a technique used for determining the elemental composition of a material or a sample. When a material is exposed to an ion beam, atomic interactions occur that give off EM radiation of wavelengths in the x-ray part of the electromagnetic spectrum specific to an element. PIXE is a powerful yet non-destructive elemental analysis technique now used routinely by geologists, archaeologists, art conservators and others to help answer questions of provenance, dating and authenticity | https://huggingface.co/datasets/fmars/wiki_stem |
Physisorption, also called physical adsorption, is a process in which the electronic structure of the atom or molecule is barely perturbed upon adsorption.
Overview
The fundamental interacting force of physisorption is Van der Waals force. Even though the interaction energy is very weak (~10–100 meV), physisorption plays an important role in nature | https://huggingface.co/datasets/fmars/wiki_stem |
A polymer brush is the name given to a surface coating consisting of polymers tethered to a surface. The brush may be either in a solvated state, where the tethered polymer layer consists of polymer and solvent, or in a melt state, where the tethered chains completely fill up the space available. These polymer layers can be tethered to flat substrates such as silicon wafers, or highly curved substrates such as nanoparticles | https://huggingface.co/datasets/fmars/wiki_stem |
The potential theory of Polanyi, also called Polanyi adsorption potential theory, is a model of adsorption proposed by Michael Polanyi where adsorption can be measured through the equilibrium between the chemical potential of a gas near the surface and the chemical potential of the gas from a large distance away. In this model, he assumed that the attraction largely due to Van Der Waals forces of the gas to the surface is determined by the position of the gas particle from the surface, and that the gas behaves as an ideal gas until condensation where the gas exceeds its equilibrium vapor pressure. While the adsorption theory of Henry is more applicable in low pressure and BET adsorption isotherm equation is more useful at from 0 | https://huggingface.co/datasets/fmars/wiki_stem |
Reactions on surfaces are reactions in which at least one of the steps of the reaction mechanism is the adsorption of one or more reactants. The mechanisms for these reactions, and the rate equations are of extreme importance for heterogeneous catalysis. Via scanning tunneling microscopy, it is possible to observe reactions at the solid gas interface in real space, if the time scale of the reaction is in the correct range | https://huggingface.co/datasets/fmars/wiki_stem |
The Rehbinder effect in physics is the reduction in the hardness and ductility of a material, particularly metals, by a surfactant film. A proposed explanation for this effect is the disruption of surface oxide films, and the reduction of surface energy by surfactants. The effect is of particular importance in machining, as lubricants reduce cutting forces | https://huggingface.co/datasets/fmars/wiki_stem |
The Salvinia effect describes the permanent stabilization of an air layer upon a hierarchically structured surface submerged in water. Based on biological models (e. g | https://huggingface.co/datasets/fmars/wiki_stem |
The sea surface microlayer (SML) is the boundary interface between the atmosphere and ocean, covering about 70% of Earth's surface. With an operationally defined thickness between 1 and 1,000 μm (1. 0 mm), the SML has physicochemical and biological properties that are measurably distinct from underlying waters | https://huggingface.co/datasets/fmars/wiki_stem |
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