Chemistry terminology · MLC-0109

Chemistry terms: H (535)

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• H-2The major histocompatibility complex (MHC) found in mice, located on chromosome 17. This gene complex encodes...
• H-2 complexThe major histocompatibility complex (MHC) found in mice, a cluster of genes on chromosome 17 that encode...
• Haber-Weiss reactionA catalytic cycle involving the interconversion of superoxide and hydrogen peroxide, generating highly...
• HabitatThe specific physical and chemical environment where an organism or population naturally lives and develops...
• HabituationA behavioral change in which an organism's response to a repeated, non-threatening stimulus diminishes over...
• Hadamard transform spectrometerAn optical instrument that uses a Hadamard encoding mask to modulate the light from a source before it...
• HaemA prosthetic group consisting of an iron atom coordinated within a porphyrin ring, specifically...
• Hairy cell leukemiaA rare, chronic lymphoid leukemia characterized by the accumulation of abnormal B lymphocytes with fine...
• Halato-telechelic polymerA telechelic polymer possessing ionic groups, specifically carboxylate or sulfonate groups, at both chain...
• Half lifeThe time required for the concentration of a reactant to decrease to half its initial value in a chemical...
• Half thicknessThe thickness of a specific material required to reduce the intensity of incident radiation, such as X-rays...
• Half-chairA conformation of a six-membered ring, such as cyclohexane, that is intermediate between the chair and boat...
• Half-peak potentialThe potential at which the current in a voltammetric peak, such as in cyclic voltammetry, reaches half of its...
• Half-value thicknessThe thickness of a specified material required to reduce the intensity of incident radiation to one-half of...
• Half-wave potentialThe potential at which the current in a polarographic or voltammetric experiment reaches exactly half of its...
• Half-widthThe width of a spectral band or peak measured at half of its maximum intensity. This parameter, also known as...
• Halirenium ionsCyclic, three-membered cationic intermediates formed during the electrophilic addition of a halogen to an...
• HallucinationA sensory experience that appears real but is not caused by an external stimulus. These perceptions can...
• HalochromismThe phenomenon where a substance changes color upon a change in pH, specifically when interacting with an...
• HaloformsOrganic compounds with the general formula CHX3, where X represents a halogen atom (fluorine, chlorine...
• Halogen bondA non-covalent interaction between an electrophilic region on a halogen atom (X) and a nucleophilic region on...
• HalohydrinsOrganic compounds containing both a hydroxyl group (-OH) and a halogen atom (F, Cl, Br, or I) on adjacent...
• Halonium ionsCationic species in which a halogen atom bears a positive charge and is bonded to two carbon atoms, forming a...
• HalophilesA class of extremophilic microorganisms that thrive and multiply in environments with very high...
• Hamiltonian operatorA quantum mechanical operator that corresponds to the total energy of a system, including both kinetic and...
• Hammett equationA linear free-energy relationship that correlates the reaction rates or equilibrium constants for a series of...
• Hammond principleA postulate in physical organic chemistry stating that the transition state of a reaction resembles the...
• HandednessA property of an object or molecule that describes its non-superimposable mirror image relationship...
• Hansch analysisA quantitative structure-activity relationship (QSAR) method that correlates the biological activity of a...
• Hansch constantA parameter that quantifies the lipophilicity of a substituent in a molecule, derived from partition...
• Hansch equationA quantitative structure-activity relationship (QSAR) model that correlates the biological activity of a...
• Hansch-Fujita π-constantA substituent constant that quantifies the lipophilicity or hydrophobicity of a chemical group relative to...
• Hantzsch-Widman nameA systematic nomenclature system for monocyclic heterocyclic compounds containing up to ten ring members...
• HaploidDescribing a cell or organism that possesses a single set of unpaired chromosomes. This state is represented...
• HaplotypeA set of DNA variations, or polymorphisms, that tend to be inherited together on the same chromosome. It...
• HaptenA small molecule that can provoke an immune response only when it is bound to a larger carrier molecule, such...
• HaptenicDescribing a substance that is capable of binding to specific antibodies but cannot, by itself, induce an...
• HapticityThe number of atoms in a ligand that are directly bonded to a central metal atom in a coordination complex...
• Hard acidA Lewis acid characterized by a small atomic or ionic radius, a high positive oxidation state, and low...
• Hard amorphous carbon filmsThin films of carbon that exhibit high hardness, low friction, and chemical inertness, lacking long-range...
• Hard baseA Lewis base characterized by a donor atom of high electronegativity, low polarizability, and high resistance...
• Hard ionizationAn ionization process in mass spectrometry that imparts a large amount of internal energy to an analyte...
• Hard waterWater that contains a high concentration of dissolved mineral ions, primarily calcium and magnesium. These...
• HardnessA measure of the concentration of dissolved multivalent metallic cations, primarily calcium and magnesium...
• Hard-segment phase domainA distinct region within a block copolymer, particularly in segmented polyurethanes or polyureas, formed by...
• Hardy-Weinberg equilibriumA theoretical state where allele and genotype frequencies within a population remain constant from one...
• HarmAn adverse effect on the health of an organism, population, or ecosystem, resulting from exposure to a...
• Harmful occupational factorAny agent, condition, or exposure in the workplace that has the potential to cause adverse health effects or...
• Harmful substanceA chemical or material that, through its inherent properties, can cause adverse effects to human health or...
• Harmonic approximationA simplification in molecular mechanics and quantum chemistry where the potential energy surface around an...
• Harmonic constantA parameter that describes the curvature of the potential energy surface near the equilibrium geometry of a...
• Harmonic frequency generationA nonlinear optical process where light interacting with a material generates new light waves at integer...
• Harmonic meanA type of average that is calculated as the reciprocal of the arithmetic mean of the reciprocals of a given...
• Harpoon mechanismA reaction mechanism in which a long-range electron transfer occurs between two species, typically an alkali...
• HartreeThe unit of energy in the Hartree atomic units system, also known as the hartree energy. It is defined as...
• Hartree energyThe atomic unit of energy, defined as the absolute value of the ground state energy of the hydrogen atom in...
• Hashimoto thyroiditisAn autoimmune disorder characterized by chronic inflammation of the thyroid gland, leading to its gradual...
• HashingThe process of converting a chemical structure into a fixed-size string of characters or a numerical value...
• Haworth representationA common method for depicting the cyclic structure of monosaccharides, particularly pyranoses and furanoses...
• Hay feverAn allergic reaction to airborne particles, such as pollen, dust mites, or pet dander, primarily affecting...
• HazardThe inherent property of a chemical agent to cause an adverse effect when a particular organism is exposed to...
• Hazard assessmentThe process of determining the intrinsic adverse effects a substance is capable of causing in an organism...
• Hazard communication standardA regulatory framework that mandates the provision of information about hazardous chemicals to workers and...
• Hazard evaluationThe scientific process of determining the intrinsic properties of a substance or agent that can cause adverse...
• Hazard identificationThe initial step in risk assessment, involving the recognition of a substance or agent's inherent capacity to...
• Hazard indexA numerical value representing the sum of hazard quotients for multiple substances or multiple exposure...
• Hazard quotientA ratio comparing the estimated exposure to a substance with a reference dose or concentration below which...
• Hazardous concentrationA statistically derived concentration of a substance in an environmental medium that is predicted to cause...
• Hazardous production factorA numerical value used in risk assessment to account for uncertainties when extrapolating toxicity data from...
• HazeAn atmospheric condition characterized by reduced visibility due to the scattering of light by a suspension...
• Haze horizonThe apparent boundary in the atmosphere where visibility is significantly reduced due to the presence of...
• HBA solventA hydrogen bond acceptor solvent, characterized by the presence of electronegative atoms (like oxygen or...
• HBD solventA hydrogen bond donor solvent, characterized by the presence of hydrogen atoms bonded to highly...
• HBHA(CO)NHA three-dimensional nuclear magnetic resonance spectroscopy experiment used to correlate the chemical shifts...
• HCCH-COSYA three-dimensional nuclear magnetic resonance (NMR) experiment designed to correlate the chemical shifts of...
• HCCH-TOCSYA three-dimensional nuclear magnetic resonance (NMR) experiment that provides through-bond correlations...
• H(CCO)NHA three-dimensional nuclear magnetic resonance (NMR) experiment used to correlate chemical shifts in proteins...
• HeadacheA sensation of pain or discomfort in the head or face, which can arise from a multitude of causes. This pain...
• HeadspaceThe gaseous phase above a condensed liquid or solid sample within a sealed container. This gas contains...
• Headspace solid-phase microextractionA sampling technique where a solid-phase microextraction fiber is exposed to the headspace above a sample to...
• Head-tail isomerismA type of structural isomerism in polymers that arises from the different ways monomer units can link...
• HealthA state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity...
• Health advisory levelA non-regulatory concentration of a contaminant in drinking water at which adverse health effects are not...
• Health hazardThe inherent potential of a chemical agent, physical agent, or mixture to cause adverse health effects in...
• Health surveillanceThe systematic and ongoing collection, analysis, and interpretation of health data for specific populations...
• Health-based exposure limitA concentration of a chemical in air, water, or food that is derived from toxicological data and is intended...
• Healthy worker effectA phenomenon observed in occupational epidemiology where the mortality or morbidity rates of an employed...
• Heart-cut separationsA technique in chromatography where a specific fraction or 'heart' of an eluting peak, containing the analyte...
• HeatThe transfer of energy between a system and its surroundings due to a temperature difference. This energy...
• Heat capacityA measure of the amount of energy required to change the temperature of a substance by a specific amount. It...
• Heat capacity of activationThe change in heat capacity between the reactants and the transition state of a chemical reaction. This...
• Heat fluxThe rate of heat energy transfer per unit area, typically measured in watts per square meter (W m^-2). It...
• Heat of polymerisationThe enthalpy change that occurs during the polymerization of a given amount of monomer to form a polymer...
• Heat shock proteinsA family of proteins that are expressed by cells in response to exposure to stressful conditions, including...
• Heat-flow differential scanning calorimetryA thermal analysis technique that measures the difference in heat flow to a sample and a reference as they...
• Heavy atom effectAn increase in the rate of intersystem crossing (ISC) and phosphorescence in a molecule when a heavy atom...
• Heavy atom isotope effectA kinetic isotope effect observed when an atom heavier than hydrogen is substituted with one of its isotopes...
• Heavy chainOne of the two types of polypeptide chains that make up an antibody molecule, larger than the light chain...
• Heavy metalA metallic element with a relatively high density, atomic weight, or atomic number, which can be toxic even...
• Heavy waterWater in which the hydrogen atoms are predominantly the deuterium isotope, ²H or D, instead of the common...
• HectoThe SI prefix used to denote a factor of 10², or one hundred. It is represented by the symbol 'h' and is...
• HedriteA specific type of polymer single crystal characterized by a lamellar morphology with a distinct central...
• Height equivalent to a theoretical plateA measure of the efficiency of a chromatographic column, representing the length of column required for one...
• Height equivalent to an effective theoretical plateA measure of chromatographic column efficiency that accounts for the dead volume in the system, reflecting...
• Helical polymerA polymer molecule whose constituent atoms trace a helical path in space, with the repeating units arranged...
• HelicenesA class of polycyclic aromatic hydrocarbons characterized by ortho-fused benzene rings or other aromatic...
• HelicityThe sense of twist or handedness of a helical structure, such as a screw, a spring, or a molecular helix. It...
• HeliochromismA reversible change in color of a substance upon exposure to sunlight or ultraviolet radiation, which then...
• HelionThe nucleus of a helium-3 (³He) atom, consisting of two protons and one neutron. It is the cation He²⁺ with...
• Helium dead-spaceThe volume within an apparatus that is not occupied by the sample and is accessible to helium gas during a...
• Helium ionization detectorAn analytical device for gas chromatography that ionizes sample components using metastable helium atoms. A...
• Helium-cadmium laserA type of gas laser that uses a mixture of helium and cadmium vapor as its active medium to produce coherent...
• Helium-neon laserA type of gas laser that uses a mixture of helium and neon gases as the active medium to produce a continuous...
• HelixA three-dimensional conformation of a polymer chain characterized by a spiral or screw-like arrangement of...
• Helix pitchThe axial distance covered by one complete turn of a helical polymer chain. This parameter quantifies the...
• Helix residueA repeating monomer unit within a polymer chain that is incorporated into a helical conformation. Each...
• Helix senseThe direction of rotation of a helical polymer chain, which can be either right-handed (clockwise) or...
• Helmholtz energyA thermodynamic potential that quantifies the useful work obtainable from a closed system at constant...
• Helper T lymphocyteA type of T lymphocyte that orchestrates the adaptive immune response by activating and directing other...
• HemagglutinationThe clumping or aggregation of red blood cells (erythrocytes). This process is induced by specific binding...
• HemagglutininA glycoprotein found on the surface of certain viruses, particularly influenza viruses, that binds to sialic...
• HemangiomaA benign tumor composed of an abnormal proliferation of blood vessels, often appearing as a red or purplish...
• HematemesisThe vomiting of blood, indicating bleeding in the upper gastrointestinal tract. The appearance of the vomited...
• HematomaA localized collection of blood outside of blood vessels, typically in liquid form within the tissue. It...
• HematopoiesisThe physiological process of blood cell formation and development, encompassing all types of blood cells...
• Hematopoietic stem cellA multipotent stem cell that gives rise to all other blood cells through the process of hematopoiesis. These...
• HematotoxicityThe adverse effects of a substance on the blood or blood-forming organs, such as the bone marrow. This can...
• HematuriaThe presence of blood in the urine, which can be either macroscopic (visible to the naked eye) or microscopic...
• HemesPorphyrin complexes containing an iron ion, which are prosthetic groups found in many proteins involved in...
• HemiacetalsOrganic compounds formed by the reversible reaction between an aldehyde or ketone and an alcohol, resulting...
• HemiaminalsOrganic compounds formed by the reversible addition of an amine to a carbonyl group (aldehyde or ketone)...
• HemicarceplexA host-guest complex where a guest molecule is partially encapsulated within a hemicarcerand, a molecular...
• HemicarcerandA molecular host compound that possesses an internal cavity capable of encapsulating guest molecules, but...
• HemiketalsOrganic compounds formed by the reversible reaction between a ketone and an alcohol, resulting in a molecule...
• HemimeliaA congenital malformation characterized by the partial or total absence of the distal part of a limb. This...
• Hemi-micelleAn ordered aggregation of surfactant molecules adsorbed onto a solid surface, forming a half-micelle-like...
• HeminsA class of iron-containing porphyrin complexes where the iron atom is in the ferric (Fe(III)) oxidation state...
• HemiplegiaParalysis affecting one side of the body, typically resulting from damage to the brain or spinal cord on the...
• HemivertebraA congenital anomaly of the spine where only one half of a vertebral body develops, leading to a wedge-shaped...
• HemochromatosisA genetic disorder characterized by excessive absorption and accumulation of iron in the body's tissues and...
• HemochromesLow-spin compounds of heme in which the fifth and sixth coordination positions on the central iron atom are...
• HemodialysisA medical procedure that removes waste products, such as urea and creatinine, and excess fluid from the blood...
• HemoglobinsMetalloproteins found in red blood cells that are responsible for transporting oxygen from the lungs to the...
• HemoglobinuriaThe excretion of free hemoglobin in the urine, resulting from the intravascular hemolysis of red blood cells...
• HemolysinA substance, often a protein or lipid, that causes the lysis of red blood cells by damaging their cell...
• HemolysisThe rupture of red blood cells and the subsequent release of their intracellular contents, primarily...
• Hemolytic anemiaA type of anemia characterized by the premature destruction of red blood cells, leading to a reduction in...
• Hemolytic disease of the newbornA condition in which a mother's antibodies cross the placenta and attack the red blood cells of her fetus or...
• HemoperfusionA medical procedure used to remove toxic substances from the blood by passing it over an adsorbent material...
• HemorrhageThe escape of blood from a ruptured blood vessel, either internally into tissues or externally from the body...
• HemosiderinAn iron-storage complex formed within cells, particularly macrophages, when there is an excess of iron. It is...
• Hen testA neurotoxicity assay used to evaluate the potential of a chemical to cause delayed neurotoxicity...
• Henderson-Hasselbalch equationAn equation that relates the pH of a buffer solution to the acid dissociation constant (pKa) of the weak acid...
• HenryThe SI unit of inductance, representing the inductance of a closed circuit in which an electromotive force of...
• Henry's lawA principle stating that the concentration of a gas dissolved in a liquid is directly proportional to the...
• Henry’s law constantA proportionality constant that relates the partial pressure of a gas above a liquid to its concentration or...
• Henry’s law solubility constantA specific form of the Henry's law constant that relates the partial pressure of a gas to its concentration...
• Henry’s law solubility constant (via b and p), see Henry’s law solubility constant
• Henry’s law solubility constant (via c and p), see Henry’s law solubility constant
• Henry’s law solubility constant (via x and p), see Henry’s law solubility constant
• Henry’s law volatility constantA specific form of the Henry's law constant that relates the concentration of a dissolved gas in the liquid...
• Henry’s law volatility constant (via p and c), see Henry’s law volatility constant
• Henry’s law volatility constant (via p and w), see Henry’s law volatility constant
• Henry’s law volatility constant (via p and x), see Henry’s law volatility constant
• Heparin-induced thrombocytopeniaAn adverse drug reaction characterized by a decrease in platelet count following exposure to heparin, an...
• HepaticRelating to or affecting the liver. In toxicology and medicine, this adjective describes processes...
• Hepatic flexureThe sharp bend in the colon located at the junction of the ascending colon and the transverse colon. This...
• HepatosplenomegalyA medical condition defined by the concurrent swelling and enlargement of the liver (hepatomegaly) and the...
• HepatotoxicDescribing a substance or agent that causes damage or injury to liver cells, leading to impaired liver...
• HerbicideA chemical substance or mixture of substances used to control, suppress, or kill unwanted plants. Herbicides...
• Hereditary angioneurotic edemaA rare genetic disorder characterized by recurrent episodes of severe swelling (edema) in the limbs, face...
• HermaphroditeAn individual possessing both male and female gonadal tissue, meaning both ovarian and testicular structures...
• HermaphroditismA biological condition characterized by the presence of both male and female reproductive organs or tissues...
• HerniaThe protrusion of an organ or tissue through an abnormal opening or weakness in the wall of the cavity that...
• HerpesA group of viral infections caused by herpes simplex viruses (HSV), characterized by outbreaks of painful...
• Hershberger bioassayA standardized in vivo assay used to detect the androgenic or antiandrogenic activity of chemical substances...
• HertzThe SI derived unit of frequency, defined as one cycle per second. Its symbol is Hz, and it quantifies the...
• Herz compoundsA class of cationic heterocyclic compounds, specifically 1,2,3-dithiazolylium salts, which contain a...
• HetarenesA class of aromatic heterocyclic compounds where one or more carbon atoms in an aromatic ring system are...
• HetarynesHighly reactive, transient intermediates that are cyclic unsaturated compounds containing a triple bond...
• HeteroalkenesAlkenes in which one or more carbon atoms in the double bond are replaced by a heteroatom. The most common...
• HeteroantigenAn antigen that is shared between different species, meaning it can elicit an immune response in one species...
• HeteroarenesAromatic heterocyclic compounds that contain at least one heteroatom (e.g., nitrogen, oxygen, sulfur) within...
• Heteroaryl groupsUnivalent groups derived from heteroarenes by the formal removal of a hydrogen atom from any position on the...
• HeteroarynesUnsaturated cyclic compounds containing at least one heteroatom within the ring and a formal triple bond...
• Heterochain polymerA polymer whose main chain contains atoms of at least two different elements, typically carbon and one or...
• HeterocoagulationThe aggregation of colloidal particles of different chemical compositions or surface properties. This process...
• HeteroconjugationThe formation of a hydrogen-bonded complex between an acid and a base that are different chemical species...
• HeterocumulenesOrganic compounds characterized by a chain of three or more cumulatively double-bonded atoms, where at least...
• Heterocyclic compoundsCyclic organic compounds where at least one atom in the ring is not carbon, but typically nitrogen, oxygen...
• Heterocyclyl groupsUnivalent groups derived from heterocyclic compounds by removing one hydrogen atom from any ring atom. These...
• Heterodetic cyclic peptideA cyclic peptide that contains at least one non-peptide bond in its ring structure, in addition to the amide...
• HeterodisperseDescribing a system, such as a colloid or polymer solution, in which the dispersed particles or molecules...
• HeteroepitaxyThe growth of a crystalline polymer layer on a substrate of a different chemical nature, where the crystal...
• HeteroexcimerAn excited-state complex formed between two different chemical species, where at least one of the species is...
• Heterogeneous assayAn analytical method in which the reactants are in different phases, requiring a physical separation step to...
• Heterogeneous binding assayA method for measuring the binding affinity or concentration of a ligand to a receptor, where the bound and...
• Heterogeneous catalysis coordination polymerizationA type of coordination polymerization where the active catalyst species are immobilized on a solid support...
• Heterogeneous crystalline membrane electrodesIon-selective electrodes constructed by incorporating finely ground crystalline material into an inert...
• Heterogeneous crystalline membrane ion-selective electrodeAn ion-selective electrode where the active sensing element consists of a finely divided crystalline...
• Heterogeneous degradationA degradation process in polymers where the chemical or physical changes occur unevenly throughout the...
• Heterogeneous diffusion rate constantA parameter that quantifies the rate of mass transport of a species to or from an electrode surface, where...
• Heterogeneous photocatalysisA catalytic process where light energy drives a chemical reaction at the surface of a solid catalyst, which...
• Heterogeneous radiation catalysisA form of radiation catalysis where the catalyst exists in a different phase from the reactants and products...
• HeterojunctionA boundary formed between two dissimilar semiconductor materials, which have different band gaps. This...
• HeterolepticDescribing a coordination compound or complex that contains two or more different types of ligands bound to...
• Heterologous antibodyAn antibody produced in a species different from the species that provided the antigen used to elicit the...
• Heterologous antigenAn antigen that is derived from a species different from the host organism, or an antigen that is...
• HeterolysisThe cleavage of a covalent bond in which both of the bonding electrons are retained by one of the fragments...
• Heterolytic bond-dissociation energyThe energy required to break a specific bond in a molecule such that both electrons from the bond remain with...
• Heterolytic dissociative adsorptionA type of adsorption where a molecule breaks into two or more fragments upon binding to a surface, with the...
• Heteronuclear decouplingA technique in nuclear magnetic resonance (NMR) spectroscopy where a strong radiofrequency field is applied...
• Heteronuclear multiple bond correlation NMRA two-dimensional nuclear magnetic resonance (NMR) experiment that correlates the chemical shifts of two...
• Heteronuclear multiple-bond correlation over two bondsA two-dimensional nuclear magnetic resonance (NMR) experiment that correlates the chemical shifts of two...
• Heteronuclear multiple-quantum correlation NMRA two-dimensional nuclear magnetic resonance (NMR) experiment that correlates the chemical shifts of two...
• Heteronuclear multiple-quantum correlation with additional TOCSY transferA two-dimensional nuclear magnetic resonance (NMR) experiment that combines heteronuclear multiple-quantum...
• Heteronuclear Overhauser effect spectroscopyA two-dimensional nuclear magnetic resonance (NMR) experiment that measures cross-relaxation rates between...
• Heteronuclear shift correlation NMRA class of two-dimensional nuclear magnetic resonance (NMR) experiments that establish correlations between...
• Heteronuclear single quantum correlationA two-dimensional nuclear magnetic resonance (NMR) experiment that correlates the chemical shifts of directly...
• Heteronuclear single quantum correlation with additional TOCSY transferA nuclear magnetic resonance (NMR) experiment that combines heteronuclear single quantum correlation (HSQC)...
• Heteronuclear single quantum multiple-bond correlationA two-dimensional nuclear magnetic resonance (NMR) experiment that correlates the chemical shift of a proton...
• HeterophagyThe process by which a cell engulfs and degrades extracellular material, such as pathogens or cellular...
• Heterophile antibodyAn antibody that reacts with antigens from unrelated species, or with antigens that are structurally similar...
• Heterophile antigenAn antigen that is present in more than one species but is structurally similar enough to elicit...
• HeteropolysaccharideA polysaccharide composed of two or more different types of monosaccharide units. These monomers are joined...
• Heterotactic macromoleculeA macromolecule in which the relative configurations of adjacent configurational repeating units are not all...
• HeterothermAn animal that exhibits different thermal relations, behaving as an endotherm at some times and as an...
• HeterotrophAn organism that obtains its necessary chemical energy and carbon for growth by consuming organic matter from...
• HeterotrophicDescribing an organism that obtains its carbon and energy by consuming organic compounds produced by other...
• Heterotrophic successionA type of ecological succession that occurs in an environment rich in organic matter, where the initial...
• HeterozygoteAn individual organism that possesses two different alleles for a particular gene at corresponding loci on...
• Heterozygote advantageA phenomenon in genetics where individuals who are heterozygous for a particular gene have a higher fitness...
• HeterozygousDescribing an individual organism that carries two different alleles for a specific gene at the corresponding...
• Hexagonal graphiteThe most common and stable allotrope of graphite, characterized by a crystal structure where the carbon atoms...
• Hexagonal mesophaseA liquid crystalline phase characterized by a hexagonal arrangement of cylindrical aggregates. These...
• Hexahedro-A polyhedral prefix used in systematic nomenclature to denote a molecular cage structure with the topology of...
• Hexaprismo-A polyhedral prefix used in systematic nomenclature to denote a molecular cage structure with the topology of...
• Heyrovský-Ilkovič equationAn equation that describes the current-potential curve for a reversible electrode reaction at a dropping...
• Hiatal herniaA condition where a portion of the stomach protrudes upward through the diaphragm into the chest cavity. This...
• Hidden layerA layer of interconnected nodes in an artificial neural network that lies between the input layer and the...
• Hierarchical clusteringA method of cluster analysis that builds a hierarchy of clusters, either by starting with individual data...
• High endothelial venuleSpecialized post-capillary venous swellings that function as gateways for lymphocytes to move from the blood...
• High throughputA methodology or technology designed to rapidly perform a large number of experiments or analyses in a short...
• High-content screening assayA method that uses automated microscopy and image analysis to extract multiple quantitative measurements from...
• Higher-energy collision dissociationA fragmentation method in tandem mass spectrometry where ions are accelerated to high kinetic energy and then...
• Higher-order systemA chemical system composed of more than three independent components. This classification extends beyond...
• Higher-order transitionA phase transition where the first derivatives of the Gibbs energy with respect to temperature and pressure...
• High-field asymmetric waveform ion mobility spectrometryAn ion mobility spectrometry technique that separates ions based on their differential mobility in high and...
• Highly active antiretroviral therapyA combination of several antiretroviral drugs used to treat human immunodeficiency virus (HIV) infection...
• Highly oriented pyrolytic graphiteA form of pyrolytic graphite that has undergone post-deposition heat treatment and mechanical compression to...
• Highly oriented pyrolytic graphite electrodeAn electrode fabricated from graphite that has been subjected to high temperatures and pressures, resulting...
• High-mobility group box proteinA family of non-histone, DNA-binding proteins that can bind to the minor groove of the DNA helix, inducing...
• High-pass filterAn electronic filter that allows signals with frequencies higher than a certain cutoff frequency to pass...
• High-performance liquid chromatography assayAn analytical technique that separates, identifies, and quantifies components in a mixture by pumping a...
• High-pressure graphitizationA process of transforming carbon materials into a graphitic structure by applying high pressures, typically...
• High-pressure mercury lampA type of gas-discharge lamp that produces light by passing an electric arc through vaporized mercury at high...
• High-speed counter-current chromatographyA liquid-liquid chromatography technique that separates compounds based on their differential partitioning...
• High-throughput screeningA method for rapidly testing a large number of chemical or biological samples for a specific activity or...
• Hilbert transformsA mathematical operation that shifts the phase of every frequency component of a signal by 90 degrees without...
• Hildebrand parameterA quantitative measure of the cohesive energy density of a material, often used to predict the solubility of...
• Hill plotA graphical representation used in biochemistry to analyze the cooperativity of ligand binding to a...
• Hinge regionA flexible polypeptide segment within an antibody molecule, located between the Fab and Fc regions of the...
• HippingA process for densifying a porous material by subjecting it to high isostatic pressure at an elevated...
• Hippocampal slice cultureAn ex vivo preparation involving thin sections of hippocampal tissue maintained in a nutrient medium. This...
• HippocampusA major component of the limbic system in the vertebrate brain, located in the medial temporal lobe. It is...
• Hirschsprung syndromeA congenital condition characterized by the absence of nerve cells (ganglion cells) in a segment of the...
• HirsutismA condition in women characterized by excessive growth of coarse, dark hair in a male-like pattern, such as...
• HistamineA biogenic amine derived from the amino acid histidine, involved in local immune responses, acting as a...
• HistaminergicRelating to neurons, receptors, or other biological systems that involve histamine as a neurotransmitter or...
• HistaminosisA condition characterized by an accumulation of histamine in the body, often due to an imbalance between...
• HistocompatibilityThe property of tissues being immunologically tolerated when transplanted from a donor to a recipient. This...
• Histogenic originThe specific tissue from which a biological structure, particularly a tumor, develops. This classification is...
• HistoincompatibilityThe state in which tissues from a donor are immunologically recognized as foreign and rejected by a...
• HistologyThe scientific study of the microscopic structure of biological tissues and organs. This field involves...
• HistonesA family of small, basic proteins found in the nuclei of eukaryotic cells, responsible for packaging...
• HistopathologyThe microscopic examination of tissue to study the manifestations of disease. Tissue samples obtained through...
• HitA compound that demonstrates a predefined level of activity in a screening assay during a drug discovery...
• Hit expansionThe process of synthesizing and testing a series of structurally related compounds around an initial 'hit'...
• Hit rateThe proportion of compounds tested in a screening assay that exhibit a desired activity above a predefined...
• Hit thresholdA predefined statistical or biological cutoff value used to distinguish active compounds (hits) from inactive...
• Hit-and-run effectA toxicological phenomenon where a transient exposure to a substance causes persistent or delayed adverse...
• Hit-to-lead chemistryThe process in drug discovery that transforms a compound identified in a primary screen, known as a 'hit'...
• HivesAn allergic skin reaction characterized by the sudden appearance of itchy, raised, red welts (wheals) on the...
• HNCAA three-dimensional nuclear magnetic resonance (NMR) experiment employed for backbone assignment in proteins...
• HN(CA)COA three-dimensional nuclear magnetic resonance (NMR) experiment used to correlate the amide proton (H) and...
• HNCOA three-dimensional nuclear magnetic resonance spectroscopy experiment that correlates the chemical shift of...
• HN(CO)CAA three-dimensional nuclear magnetic resonance spectroscopy experiment that correlates the chemical shift of...
• Hodgkin diseaseA type of lymphoma, which is a cancer originating from the lymphatic system, a part of the body's immune...
• Hoffman-Weeks plotA graphical method used to determine the equilibrium melting temperature of a semicrystalline polymer. The...
• Hofmann ruleA regioselectivity rule in elimination reactions, particularly for the Hofmann elimination of quaternary...
• Hold-back carrierA non-radioactive substance added to a solution to prevent the precipitation or co-precipitation of a...
• Hold-up timeThe time required for an unretained component to pass through a chromatographic column from the point of...
• Hold-up volumeThe total volume of the mobile phase within a chromatographic column, including the interstitial volume...
• HoleA conceptual positive charge carrier in a semiconductor or insulator, representing the absence of an electron...
• Hole burningA spectroscopic technique where a narrow spectral feature, or 'hole', is created in the absorption band of a...
• Hole transferThe movement of a positive charge (a 'hole') from one molecular entity to another, often occurring in...
• Hole-transporting materialA substance, often a polymer or organic small molecule, in which the dominant charge carriers are holes...
• Hollow fibreA semi-permeable membrane in the form of a fine tube, with a diameter typically ranging from tens to hundreds...
• Hollow-cathode discharge sourceA type of glow discharge source where the cathode is constructed as a hollow cylinder or cup, which confines...
• Hollow-cathode lampA light source used in atomic absorption spectroscopy that consists of a cathode made of the analyte element...
• Hollow-fibre liquid-phase microextractionA microextraction technique where a porous hollow fibre acts as a support for a thin layer of organic...
• Holoblastic cleavageA type of cell division (cleavage) that occurs during early embryonic development, where the entire egg or...
• HoloenzymeA biochemically active compound formed by the combination of an apoenzyme (the protein component) and a...
• HoloprosencephalyA congenital disorder resulting from the failure of the embryonic forebrain, or prosencephalon, to divide...
• HomeoboxA specific DNA sequence, approximately 180 base pairs long, found within genes that regulate anatomical...
• Homeobox geneA gene that contains a homeobox sequence, which is a DNA segment encoding a protein domain called a...
• HomeosisThe transformation of one serially repeated body part into another, such as the development of a leg in place...
• HomeostasisThe maintenance of a stable, constant internal environment within a living organism, counteracting external...
• HomingThe process by which circulating cells, such as lymphocytes or hematopoietic stem cells, migrate from the...
• Homing receptorA cell surface receptor that mediates the directed migration of cells, particularly leukocytes, to specific...
• HomoA prefix used in organic nomenclature to denote a homologue of a parent compound containing one additional...
• HomoaromaticDescribing a cyclic conjugated system that exhibits aromatic character despite having one or more saturated...
• Homochain polymerA polymer whose main chain is composed solely of atoms of a single element. This means the backbone of the...
• HomocoagulationThe aggregation of dispersed particles of the same chemical composition or surface properties. This process...
• HomoconjugationThe interaction between a pi-electron system and an isolated double bond or aromatic ring through space...
• Homocyclic compoundsMolecules containing a ring structure composed solely of atoms of the same element. In the vast majority of...
• Homocytotropic antibodyAn antibody that binds to cells of the same species, particularly mast cells and basophils, through its Fc...
• Homodesmotic reactionA hypothetical reaction in which the number of bonds of a given type (e.g., C-C, C=C, C-H) and the...
• Homodetic cyclic peptideA cyclic peptide in which the ring structure is formed exclusively by peptide bonds between amino acid...
• HomoepitaxyThe growth of a crystalline polymer layer on a substrate of the same chemical nature, where the crystal...
• HomogeneityThe uniformity of a property or constituent throughout a material. In the context of sampling, a material is...
• Homogeneous assayA type of bioassay where all components of the reaction, including the sample, reagents, and the product...
• Homogeneous binding assayA type of biochemical assay that measures the interaction between two or more molecules in a single solution...
• Homogeneous catalysis coordination polymerizationA type of coordination polymerization where the active catalyst species are dissolved uniformly in the...
• Homogeneous crystalline membrane electrodesIon-selective electrodes where the membrane consists of a single, continuous crystalline phase that is...
• Homogeneous crystalline membrane ion-selective electrodeAn ion-selective electrode featuring a membrane made from a single, continuous crystalline material, such as...
• Homogeneous degradationA type of polymer degradation where the entire bulk of the material undergoes chemical breakdown at a...
• Homogeneous line-broadeningThe broadening of a spectral line where all individual atoms or molecules in the sample contribute equally to...
• Homogeneous micellisation nucleationThe formation of new polymer particles in emulsion polymerization that occurs within the aqueous phase...
• Homogeneous particleA particle in a dispersed system that possesses uniform chemical composition and physical properties...
• Homogeneous photocatalysisA catalytic process where light energy drives a chemical reaction, and the photocatalyst is in the same phase...
• Homogeneous polymer blendA mixture of two or more polymers that is miscible at the molecular level, forming a single phase. This means...
• Homogeneous precipitationA precipitation technique where the precipitating agent is generated slowly and uniformly throughout the...
• Homogeneous radiation catalysisA catalytic process where ionizing radiation, such as gamma rays or electron beams, initiates or accelerates...
• HomojunctionAn interface formed between two regions of the same semiconductor material, but with different doping...
• HomologousRelating to structures, genes, or proteins in different species that are derived from a common ancestor...
• Homologous polymer blendA polymer blend composed of two or more polymers that are chemically identical but differ in their molecular...
• Homologous recombinationA genetic recombination process where nucleotide sequences are exchanged between two similar or identical DNA...
• HomologyThe state of having a shared ancestry between a pair of structures or genes in different taxa. It is an...
• Homology modelA three-dimensional structural model of a protein constructed based on its amino acid sequence similarity to...
• HomolysisThe cleavage of a covalent bond in which each of the bonding electrons is retained by one of the fragments...
• Homolytic dissociative adsorptionA type of adsorption where a molecule breaks into two or more fragments upon binding to a surface, with the...
• HomomorphicDescribing two or more ligands or groups attached to a central atom that are constitutionally identical but...
• Homonuclear decouplingA nuclear magnetic resonance (NMR) technique that removes scalar coupling between nuclei of the same isotope...
• HomopolymerA polymer derived from a single type of monomer unit, which is repeated along the polymer chain. The monomer...
• Homopolymer isomorphismThe phenomenon where two chemically distinct homopolymers can crystallize together to form a single, mixed...
• HomopolymerizationA polymerization process in which a single type of monomer molecule reacts to form a polymer chain. This...
• HomopolysaccharideA polysaccharide composed of a single type of monosaccharide repeating unit, also known as a homoglycan...
• HomopropagationA propagation step in a copolymerization reaction where a growing polymer chain adds a monomer unit of the...
• HomotopicDescribing two atoms or groups within a molecule that are interchangeable by a C2 rotational axis of symmetry...
• HomozygoteAn individual organism that has two identical alleles for a particular gene at corresponding loci on...
• HomozygousDescribing an individual or a cell that possesses two identical alleles for a specific gene at the...
• Honey bee larval toxicity testA standardized bioassay used to assess the toxic effects of chemical substances on the developing larvae of...
• Honeycomb polymer filmA polymer film characterized by a highly ordered, porous structure resembling a honeycomb pattern on its...
• Hopping transportA mechanism of charge carrier movement in disordered or amorphous materials, such as many organic...
• Horizontal elutionA chromatographic technique where the mobile phase flows horizontally across a stationary phase. This method...
• HormesisA dose-response phenomenon characterized by a low-dose stimulation and a high-dose inhibition, resulting in a...
• HormoneA signaling molecule produced by glands in multicellular organisms, transported by the circulatory system to...
• Horror autotoxicusA concept describing the body's innate mechanism to prevent the immune system from attacking its own tissues...
• Horwitz equationAn empirical equation that describes the relationship between the interlaboratory coefficient of variation...
• Horwitz ratioA metric used to compare the observed interlaboratory reproducibility standard deviation of an analytical...
• HostA molecular entity that forms a non-covalent complex with another molecular entity, known as the guest...
• Host defenseThe collective mechanisms by which an organism protects itself from infection by pathogens and from the...
• Host responseThe reaction of a living system to the presence of a foreign material, such as a polymer implant or device...
• Host-resistance assayA laboratory test used to evaluate the ability of an organism to resist infection or disease after exposure...
• Host-vector systemA combination of a host organism and a vector, such as a plasmid or virus, used in genetic engineering to...
• Hot atomAn atom possessing kinetic energy significantly greater than the thermal energy of its surroundings...
• Hot cellA heavily shielded enclosure designed to safely handle and manipulate highly radioactive materials...
• Hot electronA charge carrier, specifically an electron, in a solid that possesses a kinetic energy significantly greater...
• Hot ground state reactionA chemical reaction that occurs from a vibrationally excited state of the ground electronic state of a...
• Hot state reactionA photochemical reaction that proceeds from a vibrationally excited electronic state of a reactant molecule...
• Hot transitionAn electronic transition that originates from an excited vibrational state of the initial electronic state...
• HourA unit of time accepted for use with the International System of Units (SI), with the symbol h. It is not an...
• Hückel (4n + 2) ruleA rule used to predict the aromaticity of planar, cyclic, conjugated systems. According to this rule, a...
• Hückel molecular orbital theoryA simplified molecular orbital theory used to describe the pi electron systems of conjugated hydrocarbons. It...
• Huggins coefficientAn empirical parameter that quantifies the polymer-solvent interactions in dilute polymer solutions...
• Huggins equationAn empirical equation that describes the concentration dependence of the reduced viscosity for dilute polymer...
• Huisgen reactionA cycloaddition process involving the combination of a three-atom component, known as a 1,3-dipole, with a...
• Hula-twist mechanismA specific pathway for photochemical isomerization around a double bond, where one half of the molecule...
• Human chorionic somatomammotropinA polypeptide hormone produced by the placenta during pregnancy that modifies the mother's metabolic state...
• Human ecologyThe interdisciplinary study of the dynamic interrelationships between human populations and their surrounding...
• Human equivalent doseA dose of a substance in humans that is predicted to produce the same effect as a given dose in an animal...
• Human exposure thresholdThe lowest concentration or amount of a substance to which humans can be exposed without experiencing an...
• Human Genome ProjectA large-scale international scientific research endeavor initiated in 1990 with the goal of determining the...
• Human immunodeficiency virusA retrovirus that targets and destroys specific cells of the immune system, primarily CD4+ T cells, leading...
• Human leukocyte antigenA set of cell surface proteins encoded by genes on chromosome 6 in humans, responsible for the regulation of...
• Human leukocyte antigen polymorphismThe existence of multiple alleles for human leukocyte antigen (HLA) genes within the human population...
• Human leukocyte antigen type IA class of major histocompatibility complex (MHC) proteins expressed on the surface of nearly all nucleated...
• Human leukocyte antigen type IIA class of human leukocyte antigen (HLA) molecules primarily expressed on antigen-presenting cells such as B...
• Humanized antibodyA type of monoclonal antibody engineered to reduce immunogenicity when administered to humans, typically...
• Humic substancesComplex, heterogeneous organic compounds formed from the decomposition of plant and animal matter in soils...
• HumidityA measure of the amount of water vapor present in a gas, particularly in the air. It can be expressed in...
• HumoralRelating to the components within body fluids (humors), such as blood plasma, lymph, and tissue fluids, as...
• Humoral immune responseAn immune response mediated by macromolecules, primarily antibodies, circulating in the extracellular fluids...
• Humoral immunityA component of the adaptive immune system that involves the action of antibodies and other soluble molecules...
• Hund rulesA set of principles used to determine the ground state electron configuration of an atom or molecule when...
• Huntington diseaseA progressive neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive...
• Hutchinsonian nicheA conceptual framework that defines a species' niche as an n-dimensional hypervolume, where each dimension...
• HybridAn offspring resulting from the interbreeding of two genetically distinct individuals, often from different...
• Hybrid artificial organAn artificial organ that combines synthetic materials with living biological components, such as cells or...
• Hybrid latexA colloidal dispersion of polymer particles formed by a multi-stage polymerization process, where at least...
• Hybrid mass spectrometerA mass spectrometer that combines two or more different types of mass analyzers in series, allowing for...
• Hybrid materialA material composed of two or more distinct phases, at least one of which is organic and another inorganic...
• Hybrid orbitalA conceptual orbital formed by the mathematical combination of atomic orbitals on the same atom. This mixing...
• Hybrid polymerA macromolecular substance that incorporates both organic and inorganic components within its structure...
• HybridizationThe process of mixing atomic orbitals on a central atom to form new hybrid orbitals that are degenerate and...
• Hybridization assayAn analytical method that detects specific nucleotide sequences (DNA or RNA) by exploiting their ability to...
• HybridomaA hybrid cell line produced by fusing an antibody-producing B lymphocyte with a myeloma (cancer) cell. This...
• Hydatidiform moleA rare complication of pregnancy characterized by the abnormal growth of trophoblasts, the cells that...
• HydranencephalyA rare congenital condition in which the cerebral hemispheres are absent or severely reduced and replaced by...
• HydrateA crystalline solid compound in which water molecules are incorporated into the crystal lattice structure...
• HydrationThe process by which water molecules associate with a solute or a surface, forming a hydration shell or...
• HydrazidesOrganic compounds containing the functional group R-CO-NH-NH2, derived from carboxylic acids where the...
• HydrazidinesA class of organic compounds characterized by a carbon atom double-bonded to a nitrogen atom, which is also...
• HydrazinesA class of organic compounds containing the N-N single bond, derived from hydrazine (H2N-NH2) by replacement...
• Hydrazo compoundsOrganic compounds containing the -NH-NH- functional group, where both nitrogen atoms are bonded to organic...
• HydrazonesOrganic compounds formed by the condensation reaction of a hydrazine with an aldehyde or a ketone, containing...
• Hydrazonic acidsA class of organic compounds that are derivatives of carboxylic acids, where the carbonyl oxygen is replaced...
• HydrocarbonsOrganic compounds composed entirely of carbon and hydrogen atoms. They are classified into major groups based...
• Hydrocarbyl groupsUnivalent groups composed solely of carbon and hydrogen atoms, derived from hydrocarbons by the removal of...
• Hydrocarbylene groupsBivalent groups derived from hydrocarbons by the removal of two hydrogen atoms from different carbon atoms or...
• Hydrocarbylidene groupsDivalent groups derived from hydrocarbons by the removal of two hydrogen atoms from the same carbon atom...
• Hydrocarbylidyne groupsTrivalent groups derived from hydrocarbons by the removal of three hydrogen atoms from the same carbon atom...
• HydroceleAn accumulation of serous fluid within a body cavity, specifically the tunica vaginalis, which is the...
• HydrocephalusAn abnormal accumulation of cerebrospinal fluid within the ventricles of the brain, leading to increased...
• Hydrocracking unitA refinery processing unit that converts heavy petroleum fractions into lighter, more valuable products such...
• Hydrodynamic chromatographyA separation technique for macromolecules and particles based on their size in a flowing liquid within a...
• Hydrodynamic injectionA method of introducing a sample into a capillary electrophoresis system by applying a pressure difference...
• Hydrodynamic interactionThe influence of a polymer chain's movement on the solvent flow field, which in turn affects the motion of...
• Hydrodynamic voltammetryAn electrochemical technique that combines voltammetry with controlled fluid flow past an electrode surface...
• Hydrodynamic volumeThe effective volume occupied by a macromolecule in solution, including the volume of the polymer itself and...
• Hydrodynamically equivalent sphereA hypothetical sphere that exhibits the same hydrodynamic properties, such as sedimentation coefficient or...
• HydrogelA three-dimensional network of hydrophilic polymer chains that can absorb and retain large amounts of water...
• HydrogenThe chemical element with atomic number 1, the lightest and most abundant element in the universe. It...
• Hydrogen bondAn attractive interaction between a hydrogen atom covalently bonded to a highly electronegative atom (such as...
• Hydrogen gas electrodeA type of electrode that involves the equilibrium between hydrogen gas and hydrogen ions in an acidic...
• Hydrogen shiftsA type of rearrangement reaction observed in mass spectrometry where a hydrogen atom or proton migrates...
• Hydrogen/deuterium exchangeA method in mass spectrometry where labile hydrogen atoms in a molecule are replaced by deuterium atoms. This...
• HydrolasesA class of enzymes that catalyze the hydrolysis of a chemical bond, a reaction where a water molecule is used...
• HydrolysisA chemical reaction in which water reacts with a compound, breaking one or more chemical bonds and often...
• Hydrolysis ratioThe proportion of hydrolyzable groups in a precursor molecule that have undergone hydrolysis in a given...
• HydrometeorAn atmospheric particle composed of liquid water or ice that is formed through condensation or deposition of...
• HydromicrocephalyA developmental abnormality characterized by the concurrent presence of microcephaly, an abnormally small...
• HydromyeliaA neurological condition characterized by the abnormal widening of the central canal of the spinal cord...
• HydronationThe addition of a hydron (H+) to a substrate. This process increases the number of hydrons attached to the...
• HydronephrosisThe swelling of a kidney due to a backup of urine, caused by an obstruction in the urinary tract. This...
• HydroperoxidesOrganic compounds containing the hydroperoxy group, -OOH, attached to an organic radical. These compounds are...
• Hydrophile-lipophile balance systemA numerical scale used to classify surfactants based on their relative affinity for water (hydrophilic)...
• HydrophilicDescribing a molecular entity or a part of a molecule that has an affinity for water and tends to dissolve...
• Hydrophilic interactionAn energetically favorable interaction between polar groups on a polymer chain and a surrounding aqueous...
• Hydrophilic-interaction liquid chromatographyA chromatographic technique for separating polar and hydrophilic compounds using a polar stationary phase and...
• HydrophilicityThe physicochemical property of a molecule or a molecular entity that describes its tendency to associate...
• HydrophobicDescribing a substance or a part of a molecule that lacks affinity for water and tends to repel it. These...
• Hydrophobic fragmental constantA numerical value representing the contribution of a specific molecular fragment to the overall...
• Hydrophobic interactionThe tendency of nonpolar molecules or nonpolar parts of molecules to aggregate in an aqueous solution...
• Hydrophobic-interaction chromatographyA chromatographic method for separating biomolecules, primarily proteins, based on differences in their...
• HydrophobicityThe physicochemical property of a molecule or a molecular entity that describes its tendency to avoid water...
• HydropolysulfidesOrganic compounds containing a chain of sulfur atoms with hydrogen atoms attached to the terminal sulfur...
• HydropsAn excessive accumulation of serous fluid in one or more body cavities or tissues, leading to generalized...
• HydrosphereThe total mass of water on a planet, including water in liquid, solid, and gaseous forms. This encompasses...
• HydrosulfidesOrganic compounds containing the -SH functional group, where a hydrocarbyl group is attached to a sulfur atom...
• HydroureterThe dilation and distension of the ureter, the tube that carries urine from the kidney to the bladder, due to...
• Hydroxamic acidsOrganic compounds characterized by the functional group R-CO-NH-OH, where R is an organic radical. These are...
• Hydroximic acidsOrganic compounds containing the functional group R-C(=N-OH)-OH, where R is an organic radical. These are...
• HydroxylaminesOrganic compounds containing the -NH-OH functional group, where an organic group is attached to the nitrogen...
• HygienePractices and conditions that promote health and prevent the spread of disease, particularly through...
• HygrometerAn instrument for measuring the amount of water vapor in the air or another gas, expressing the result as...
• HygroscopicityThe property of a substance to attract and hold water molecules from the surrounding environment, typically...
• Hyoid archThe second of the embryonic pharyngeal arches, also known as branchial arches, which appears in the...
• HypaxialRelating to the musculature and skeletal elements situated ventral to the vertebral column in vertebrates...
• Hyper-A prefix denoting 'above', 'over', or 'in excess of' a normal or reference state. In toxicology and clinical...
• HyperalimentationThe administration of nutrients beyond the normal dietary intake, typically intravenously, to provide...
• HyperbilirubinemiaAn elevated concentration of bilirubin in the blood, exceeding the normal physiological range. This condition...
• Hyperbranched macromoleculeA macromolecule characterized by a highly branched, tree-like structure with a large number of terminal...
• Hyperbranched oligomerA macromolecule with a highly branched, irregular structure, typically formed by a single monomer type or a...
• Hyperbranched oligomer moleculeA single molecule of a hyperbranched oligomer, characterized by its low molecular weight and a highly...
• Hyperbranched polymerA polymer possessing a highly branched, irregular, tree-like structure with numerous terminal groups, but...
• HypercalcemiaAn abnormally high concentration of calcium ions in the blood. This condition arises when the rate of calcium...
• HypercapniaAn abnormally elevated concentration of carbon dioxide in the arterial blood, resulting from inadequate...
• Hyperchromic effectAn increase in the absorption of ultraviolet light by a substance, such as DNA, due to changes in its...
• HyperconjugationThe stabilizing interaction that arises from the delocalization of electrons from a filled sigma (σ) bond...
• HypercoordinationA state in which an atom forms more bonds than predicted by the octet rule, or more bonds than its typical...
• HyperemiaAn increased blood flow to a specific tissue or organ, resulting from the dilation of arterioles and...
• HyperesthesiaAn abnormal increase in sensitivity to sensory stimuli, particularly touch or pain, without a specific nerve...
• HyperextensionThe movement of a joint beyond its normal anatomical range of extension, often resulting in injury to...
• HyperfineRelating to the interactions between the magnetic moments of electrons and atomic nuclei, which cause...
• Hyperfine couplingThe interaction between the magnetic moment of an electron and the magnetic moment of an atomic nucleus...
• HyperflexionThe movement of a joint beyond its normal anatomical range of flexion, which can lead to tissue damage or...
• HyperglycemiaA condition characterized by an abnormally high concentration of glucose in the blood. It is a hallmark of...
• Hyperimmunoglobulin E syndromeA rare primary immunodeficiency disorder characterized by extremely high levels of immunoglobulin E (IgE) in...
• Hyperimmunoglobulin M syndromeA rare primary immunodeficiency disorder characterized by normal or elevated levels of immunoglobulin M (IgM)...
• HyperkalemiaAn elevated concentration of potassium ions in the blood serum, surpassing the normal physiological range...
• Hyperlayer focusing field-flow fractionationA variant of field-flow fractionation where particles are focused into a narrow layer within the channel by...
• HypernatremiaAn electrolyte disturbance characterized by an elevated sodium concentration in the blood plasma, exceeding...
• HyperparathyroidismA condition resulting from excessive secretion of parathyroid hormone (PTH) by the parathyroid glands. This...
• HyperplasiaAn increase in the number of cells in an organ or tissue, leading to an increase in its overall size. This...
• HyperpolarizabilityA measure of the non-linear response of a molecule's induced dipole moment to an external electric field...
• HyperpolarizationA change in a cell's membrane potential that makes it more negative than its resting potential. This occurs...
• hyper-Raman spectroscopyA non-linear optical spectroscopic technique that involves the inelastic scattering of two photons, resulting...
• HyperreactivityAn exaggerated or abnormally strong response of an organism or its immune system to a stimulus that would...

535 of 13,678 terms in Chemistry terminology (MLC-0109). Request the full dataset.