A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
GLOSSARY
AFM Atomic Force Microscopy
Adatom. Atom adsorbed on a surface. Adsorption is a phenomenon in which the atoms or molecules of a gas or liquid fix onto a solid surface through van der Waals interactions.
Adenosine triphosphate (ATP). A molecule which, in all living organisms, supplies by hydrolysis the energy required for the chemical reactions of the metabolism.
Aggregate. Object resulting when a set of distinct entities, which may or may not be of the same kind, adhere to one another to form a single ensemble.
Alkane. Saturated hydrocarbon with only single carbon-carbon bonds.
Alkene. Unsaturated hydrocarbon with one carbon-carbon double bond.
Alkoxide. Organic group bonded to a negatively charged oxygen atom (R-O-).
Alkoxyamine group. Chemical group initiating nitroxide-mediated polymerization (NMP).
Alkyne. Unsaturated hydrocarbon with a carbon-carbon triple bond.
Alkyl group. These derive from alkanes by loss of one hydrogen atom. They may be radicals or substituents on complex organic molecules.
Allotrope. Chemical element in one of its possible crystal structures, e.g., carbon in the form of graphite, diamond, or graphene.
Amide. Organic compound derived from a carboxylic acid which has a nitrogen atom bonded to its carbonyl group.
Amine group. Functional group derived from ammonia, e.g., - NH2.
Amino acid. Chemical compounds with two functional groups, viz., a carboxyl group and an amine group. These are the elementary building blocks of proteins.
Amphiphile. A molecule with a hydrophilic polar head and a hydrophobic
nonpolar tail.
Antibody. Substance synthesised by a living being in response to stimulation by an antigen whose toxic effects are thereby neutralised.
Antigen. An antigen is a natural or synthetic macromolecule, recognised by antibodies or cells of the immune system and able to generate an immune response.
Apoptosis. Programmed cell death.
Aromatic compound. In chemistry, a planar ring system with 4n + 2 delocalised electrons, where n is the number of rings.
Aryl group. In chemistry, a functional group which derives from an aromatic hydrocarbon such as benzene.
Atheroma. An accumulation of various materials (fats, _brous tissues, calcium deposits, blood) on part of the inner wall of an artery.
Bacterium. Single-celled organism or prokaryote present in all environments. Sizes range from 100 nm up to 2 microns.
Band gap. In a solid, the energy or frequency spacing between the valence and conduction bands. In terms of energy, it is the energy that must be given to an electron before it can contribute to conduction in the material.
Biofilm. A biofilm is a multicellular community of microorganisms such as bacteria, fungi, algae, or protozoa, sticking together and to a surface, where adhesion gives rise to the secretion of an adhesive and protective matrix. Biofilms generally form in an aqueous medium.
Biopsy. Tissue sample on a living being, taken for microscopic examination.
Bipyridines. Heterocyclic organic compounds with formula (C5H4N)2, comprising two coupled pyridines. They are colourless solids, soluble in organic solvents, and slightly soluble in water.
Bit/byte. The bit is the elementary unit of information, which can assume the values 0 or 1. A byte contains 8 bits and is the basic unit used to measure the amount of data in computing.
Cage molecule. A molecule able to encapsulate another molecule.
Carbonyl. Organic compound containing a double bond between a carbon atom and an oxygen atom, with the carbon atom bonded exclusively to hydrogen or carbon atoms.
Carboxyl group. Functional group with general formula {COOH, comprising a carbon atom bound by a double bond to a first oxygen atom and by a single bond to a second oxygen atom.
Caspase assay. Method for detecting cells and tissues undergoing apoptosis
by identifying a molecular marker for apoptosis, viz., caspase 3.
Catalysis. Process in which the rate of a chemical reaction is modified by the effects of a substance known as a catalyst.
Cement. Powdery material which, when mixed with water or a saline solution, forms a plastic binding paste that can agglomerate various substances to produce a hard solid.
Chirality. A chiral object is one that cannot be superposed on its mirror image.
Chromatography. Physical technique for separating chemical species.
Clearance. Ability to eliminate a substance or corpuscle from an organic fluid.
Click chemistry. Set of chemical reactions able to create substances quickly, efficiently, and in a modulatable way by connecting up preexisting molecular fragments or ensembles. The starting materials are freely available and generate only harmless byproducts after the reaction.
Coating. Treatment of a surface by applying a liquid coating to a substrate. Coating is generally followed by drying and possibly reticulation.
Colloid. Substance made up of small particles (micelles) suspended in a medium. It reflects light rays when the medium is a liquid.
Complexing molecule. In chemistry, a molecule that can capture and bond to ions (often metal ions) to form a complex.
Concrete. Composite construction material made from natural granular substances (sand, gravel) or artificial granular substances (lightweight aggregates) held together by a binder which is usually cement.
Covalent bond. A chemical bond between two atoms in which each atom shares one of the electrons in its outer shell to form an electron doublet which constitutes the bond.
Cracking. A technique for breaking a complex organic molecule into smaller ones.
Cross-linking. Transition of a polymer from a state in which the macromolecules are independent to one in which they are linked by chemical bonds.
Cryptography. Discipline of cryptology dedicated to the protection of messages to ensure confidentiality, authenticity, and integrity, often using secret codes or keys. The information contained in the message can then only be decoded by the sender or the recipient.
Cyclisation. Process whereby part of an organic molecule adopts a closed ring shape.
Cycloaddition. Cyclisation reaction in which unsaturated molecules, or parts of the same molecule, combine to form a cyclic product with a reduction in bond multiplicity.
Cytotoxicity. Toxicity for a species of cell. An example is genotoxicity, involving alteration of the genome.
Dendrimer. Molecule that has a branched site with reactive endpoints and another site able to attach itself to a molecular or solid support.
Deoxycytidine deaminase. Enzyme catalysing the metabolisation of gemcitabine.
Diamagnetic material. A material which, when subjected to an external magnetic field, produces another magnetic field to oppose it.
Diffusion length. Length over which a physical quantity, a number of particles, etc., drops off by a factor of e, where e ≈2.7 is the base of the natural logarithm.
Dihydroxylation. Reaction fixing an OH group on each carbon atom of the double bond in an alkene.
Drug delivery. Technique for modulating and controlling the distribution of an active principle with respect to a target by associating it with a carrier.
Electrolyte. Electrically conducting liquid or solid substance, thanks to the presence of mobile ions.
Electronvolt. Unit of energy equal to the energy acquired by an electron when it moves through a potential di_erence of one volt. Its value is 1 eV =1.6 ´10–19 joule.
Electrophilic compound. A compound attracted by negatively charged species, as opposed to a nucleophilic compound.
Emulsion. Macroscopically homogeneous mixture of two immiscible liquids.
Endocytosis. Mechanism of capture and transport of molecules and particles inside a cell.
Endogenous (exogenous) process. One whose causes lie inside (outside) a given biological entity.
Energy. See the entry for power/energy.
Equilibrative nucleoside transporter 1 (ENT1). Protein for intracellular transport of a nucleoside or nucleoside analogue.
Enzyme. Protein playing the role of a biological catalyst.
Epigenetics. Study of ways in which the environment and individual history can influence gene expression. This concerns all modifications of gene expression that are transmissible from one generation to the next, without alteration of nucleotide sequences, and reversible.
Epitaxy. Technique for growing a monocrystalline film on a substrate that is itself monocrystalline. When the substrate and the film are made from the same material, this is called homoepitaxy, while heteroepitaxy refers to the opposite case.
Epoxidation. Certain oxidation reactions of alkenes produce cyclic ethers in which the two carbon atoms connected by a double bond become bonded to the same oxygen atom. These products are known as epoxides.
Exciton. A quasiparticle that can be represented as an electron–hole pair, bound together by the Coulomb force.
Exeresis. Surgical removal of some harmful or useless element, such as an organ, a tumour, a foreign body, etc.
Exfoliation. Removal of sheets one at a time from a layered structure.
Exogenous process. See the entry for endogenous/exogenous process.
Extrusion. Mechanical or thermomechanical fabrication process used to create objects of a fixed cross-sectional profile. A material is pushed or pulled through a die with the desired cross-section.
Ferroelectric material. A material in which spontaneous electric polarisation can occur.
Ferromagnetic material. A material that can be very strongly magnetised under the effect of an external magnetic field and retain a significant magnetisation even when the field is removed (see the discussion of spin and magnetic domains in Sect. 1.5.2).
Fibrosis. Anomalous increase in the amount of fibrous conjunctive tissue in a tissue or organ.
Fluorescence. Light emission caused by excitation of a molecule (generally by absorption of a photon), immediately followed by spontaneous emission.
Fluorescence imaging. Imaging of cells or tissues through the presence of fluorescent entities which may either be present from the start or introduced into the organism artificially.
Fullerene. Molecule made from carbon atoms and which can assume a geometric shape resembling a sphere, an ellipsoid, a tube, or a ring.
Fullerol. A hydroxylated fullerene.
Galenic pharmacy. Pharmaceutical discipline which studies drug formulation.
Gemcitabine. Chemotherapy drug used in the treatment of non-small cell lung cancer, pancreatic cancer, breast cancer, and bladder cancer.
Gene therapy. Therapeutic strategy in which genes are placed in the cells or tissues of a patient to treat a disease.
Genome. Complete set of chromosomes and genes.
Genotoxicity. See entry for cytoxicity.
Hall effect. Discovered by Edwin Herbert Hall in 1879, this effect results from the force exerted by a magnetic field on electrons (the Lorentz force). When the field is normal to the direction of the electron current, the trajectory of the electrons bends and this leads to a potential difference in the perpendicular direction. This potential difference is proportional to the injected current and the magnetic field.
Helicity. For a carbon nanotube, this is the angle between the nanotube axis and one of the carbon bonds. More precisely, it is a reference direction parallel to one of the sides of the hexagons in the unit cell.
Hematoxylin-eosin (HE) stain. Classic histological staining method.
Heterostructure. Term generally used to describe multilayers of different semiconductor materials.
Histology. Branch of biology and medicine which studies biological tissues.
Hole. Particle with a positive charge equal and opposite to that of the electron. A hole results from the absence of an electron.
Hydration. In chemistry, hydration has three different meanings:
· When a product is soluble in water, the water molecules bind to the ion
or the molecule to form a sort of layer.
· When a product can absorb water, hydration is the opposite of desiccation
(dehydration, drying, lyophilisation).
· Reaction in which a water molecule is added to an organic molecule.
Hydrolysis. Decomposition of a substance by H3O+ and HO– ions produced by dissociation of water.
Hydroxylation. Chemical treatment in which a hydroxyl group OH is fixed onto a surface.
ICT. Information and communication technologies.
Immunohistochemistry. Method for detecting proteins in the cells of a tissue section by marking with antibodies.
Indentation. Technique for measuring the hardness of a material.
Intracellular enzyme. Protein synthesised by living cells which catalyse one or more biochemical reactions within the cell.
Ionic–covalent bond. An ionic–covalent bond between two atoms is a covalent bond in which there is a higher probability of finding the electron in the vicinity of one atom rather than the other.
Ionic strength. Main factor influencing the activity of ions in an aqueous solution, expressed in mol l–1.
Junction oncogene. Fused genes favouring the occurrence of cancers.
Ki67 staining. Ki67 antigen is a marker for cell proliferation.
Lifetime. Time after which a time-dependent quantity drops by a factor e, where e ≈ 2.7 is the base of the natural logarithm.
Ligand. Chemical species used by other molecules to bond together.
Lipophile. Substance with an affinity for apolar solvents like lipids.
Liposome. Vesicle made from lipids.
Lithography/nanolithography. Process for imprinting motifs in a resist, used to reproduce large numbers of nanoscale and microscale devices.
Local hyperthermia. Local rise in the temperature of the body above the normal value of 37 to 37.5°C due to the accumulation of exogenous heat. This is also the name for the cancer treatment in which the local temperature of the body is raised by subjecting implanted nanoparticles to a magnetic field, if the particles are magnetic, or infrared radiation, if the particles are sensitive to those wavelengths. The nanoparticles then become a heat source which can destroy tumour cells, for example.
Luminescence. Generic name for light emission by a source excited by light (photoluminescence), heat (thermoluminescence), chemical reaction (chemiluminescence), or electricity (electroluminescence).
Lymphoid organs. Organs containing lymphocytes or other cells of the immune system.
Lysosome. The digestive organs of the cell, these are intracellular vesicles characterised by an acidic pH and filled with enzymes.
Macrophage. Cell carrying out phagocytosis within tissues. Arising from differentiation of blood leucocytes (monocytes), they contribute to innate immunity as a non-specific defence system.
Magnetic resonance imaging (MRI). A medical imaging technique producing 2D or 3D visualisations of the inside of the body in a non-invasive way and with relatively high contrast resolution.
Magnetoresistance. Resistance whose value depends on the applied magnetic field. Classically, the magnetic field modifies the electric field lines and thus modulates the value of the resistance by a few percent.
Maleimide. Contraction of maleic acid and imide, the –CNHC functional group.
Mechanochemical polishing. Process for smoothing surfaces involving the combined action of mechanical and chemical forces. It uses a polishing cloth and a chemical solution.
Mechanosynthesis. Chemical synthesis in which reaction products result from the use of mechanical constraints to direct reactive molecules to specific molecular sites.
Memory. There are three main types of semiconductor memory: read only memory (ROM) and random access memory (RAM), which is usually volatile.
Magnetoresistive random-access memory (MRAM) is a non-volatile version of RAM.
Mesocosm. Small controlled or semicontrolled part of the natural environment in which the experimenter can vary one or more parameters, such as the soil, hygrometry, temperature, CO2 content of the air, concentration of other pollutants, etc.
Metabolisation. Transformation of substances in a living organism under the effect of enzymes.
Metal. Good electrical conductor thanks to the high density of quasi-free electrons. Unlike semiconductors, this density cannot be modulated.
Metamaterial. In physics and electromagnetism, a metamaterial is an artificial composite with electromagnetic properties that cannot be found in natural materials. A negative index metamaterial is one for which, at the interface between the metamaterial and a natural medium, the incident and refracted waves both lie at the same side of the normal to the interface.
Mobility. Parameter expressing the ability of charge carriers to move under the effects of an electric field. It is defined as the ratio of the carrier speed and the electric field, expressed in metres per second divided by volts per metre (m2v–1s–1).
Monocrystal. Crystal in which the unit cell repeats in a strictly identical way throughout, and over distances that may include several billion crystal planes.
Mucus. Viscous substance secreted by the mucous glands and serving as a protective coating for the mucous membrane. The secretion products are rich in glycoproteins and water.
Nanocarrier. Molecular assembly for transporting drugs in the body. Also called nanodroplets, nanodrugs, etc.
NBIC technologies. Nanotechnology, biotechnology, information technology, and cognitive science.
Nuclear magnetic resonance (NMR). Property of certain atomic nuclei which happen to have a magnetic moment, e.g., the proton, to resonate with radiofrequency radiation at a very precise frequency when they are placed in a magnetic field. The frequency depends on the magnetic field and other atomic or molecular factors, and in particular, the environment of the atomic nucleus. This phenomenon gave rise to magnetic resonance imaging (MRI).
Nucleophilic compound. A compound attracted by positively charged species, as opposed to an electrophilic compound.
Nucleoside. Constitutive element of RNA and DNA, comprising a base associated with a sugar.
Nucleoside analogue. Synthetic compound resembling natural nucleosides, used in the treatment of serious diseases (mainly cancers and viral infections).
Opsonisation. Immunological process used by organisms to mark exogenous particles such as bacteria, viruses, and nanoparticles, by adsorption of specific proteins called opsonins (Fc fragments of immunoglobulins, fibronectin, complement, etc.). The particles are opsonised then recognised by certain macrophages in the organism which eliminate them.
Orthotopic mouse model. Animal experimentation model using transplantation on mice.
Oxidative stress. A form of aggression on cell constituents by reactive oxygen species.
Oxidosqualene cyclase. Enzyme catalysing the cyclisation of squalene.
Paramagnetic material. A material with no spontaneous magnetisation but which, when subjected to an external magnetic field, acquires a magnetisation directed in the same direction as that field.
Pascal. The pascal (Pa) is the SI unit of pressure (newton per square metre). Further, 100 kPa = 1 bar = 760 mmHg = 10 m of H2O ≈ 1 atm.
PEGylation. PEGylated particles are coated with polyethylene glycol to reduce their elimination by macrophages in the organism.
Pellet. Wood granules.
Phagocytosis. Cell process in which microbes are destroyed by certain kinds
of leucocytes, called phagocytes.
Phonon. Quantum of vibration energy in a crystalline solid.
Phosphorylation. Enzyme mechanism adding a phosphate group to an endogenous or exogenous molecule.
Photon. Quantum of light energy.
Photonics. Study of devices for generating, transmitting, processing (modulation, amplification), or converting optical signals. Photons are treated indifferently as wave or particle.
Piezoelectric effect. Property of certain bodies to become electrically polarised under mechanical stress.
Plasma. Fluid, often a gas, made up of charged particles, ions, and electrons.
Pneumocyte. Cells lining the alveoli (air sacs) of the lungs and contributing to their function.
Power/energy. Power is the ratio of energy to the time required to dissipate it. It is given in watts (W). Energy can be expressed in joules (J), electronvolts (eV), or watt hours (Wh).
Protease. Enzyme which hydrolyses proteins and polypeptides.
Protein. Large molecules, made up of amino acids, and constituting the main part of organic matter and living beings.
Pyridines. Simple heterocyclic organic compounds with similar structure to benzene, where one of the CH groups is replaced by a nitrogen atom.
Pyrolysis. Decomposition of an organic compound by heat to produce products (gas and solids) that it did not contain previously.
Quality factor. Quantity characterising the damping of an oscillator or resonator. The bigger it is, the greater the resonance of the oscillator and the narrower its bandwidth. A high quality factor is also a characteristic of a good frequency filter.
Quantum cascade. Process in which, under an electric potential, an electron falls into a series of semiconductor quantum wells. In a quantum cascade laser, the energy lost by the electron within each quantum well is converted into emission of a photon.
Quantum dot. A semiconductor nano-object which, thanks to its size, of the order of the electron wavelength, behaves as a potential well (quantum well) for electrons in the three space dimensions.
Quantum fluctuation. In quantum physics, energy can be created at a point in space over a very short time, and this happens without violating energy conservation. This fluctuation obeys Heisenberg's uncertainty principle
∆E ´ ∆t ≈ h, where h is Planck's constant.
Quantum well. A potential well with width less than the wavelength of the relevant particle (here, an electron or a hole). A semiconductor quantum well is obtained by stacking three semiconductor layers in such a way that the middle layer has lower band gap energy than the outer layers.
Rack. Metal cabinet in which standard size boxes containing electronic or computer equipment can be slid on rails.
Raman effect. Inelastic scattering of light by molecules or atoms.
Redox reactions. Any reactions in which atoms are reduced or oxidised, i.e., electrons are transferred between chemical species. Reduction involves a gain of electrons and a decrease in the oxidation state of the molecule, atom, or ion. Oxidation involves a loss of electrons or an increase in the oxidation state of the molecule, atom, or ion. The redox potential is an empirical quantity measured in volts relative to the proton/hydrogen (H+/H2) pair, with zero potential. A positive redox potential corresponds to a strong oxidiser. A negative redox potential corresponds to a strong reducer.
Refraction. Deflection of a wave when it crosses a surface separating two media in which it propagates at different speeds (quantified by the refractive index).
Registration, evaluation and authorization of chemicals (REACH). Regulations for registration, assessment, authorisation, and restrictions on chemical substances, adopted on 18 December 2006 by the European Parliament and the Council of Europe.
Ribosome. A small structure in the cell cytoplasm which serves to assemble amino acids to form proteins.
Scale. The macroscopic is our own scale. The microscopic is the scale of the microscope (the micrometre or above). The mesoscopic is the scale between quantum and classical physics (from the atom to the micrometre) and the nanoscopic is the scale of the nanometre, hence in the middle of the mesoscopic.
Semiconductor. Material in which the density of mobile charge carriers can be varied, thereby modulating the conductivity. There are n-type and p-type semiconductors. In the former, the moving charges are negatively charged electrons, and in the latter, they are positively charged holes. A III–V semiconductor is a material made up of atoms from columns III and V of the periodic table, with as many from column III as from column V.
Speciation. In chemistry, distribution of an element depending on its state in the medium. In biology, evolutionary process whereby new living species arise.
S phase. Synthesis and replication of DNA during cell division.
Spin. Intrinsic angular momentum of a particle.
Spintronics. Spintronics or spin electronics is an area of physics which studies and exploits the quantum properties of electron spin.
Squalene. Lipid which can adopt a highly compact molecular conformation and which can be coupled to anticancer or anti-infection molecules, thus playing the role of a nanocarrier.
Stereochemistry. A subdiscipline of chemistry, involving the study of the relative spatial arrangement of atoms within molecules. An important branch of stereochemistry is the study of chiral molecules.
Stereospecificity. A chemical reaction is said to be stereospecific if reagents differing only in their stereochemistry are preferentially or exclusively transformed into products which only themselves differ by their stereochemistry.
Steric effect. The steric effect arises from the fact that each atom contained in a molecule occupies a certain space. If some atoms are brought too close to others, there will be an energy cost associated with this.
Sublimation. Direct transition from a solid to a gaseous state.
Semiconductor superlattice. Periodic structure obtained from alternating multilayers of semiconductors with different band gaps. The thickness of a pair of different layers determines the period of the superlattice.
Superconductor. Material with electrical resistance very close to zero at low temperatures.
Supramolecular chemistry. Branch of chemistry, beyond molecular chemistry, which studies non-covalent or weak interactions between molecules within a molecular system.
Surface plasmon. Collective oscillation of an electron plasma at the interface between two media. The surface plasmon is also the particular solution of the equations of propagation of electromagnetic waves or Maxwell's equations at the interface between these two media. The corresponding electromagnetic field is evanescent on either side of the interface.
Surfactant. Compound modifying the surface tension between two surfaces.
Synapse. Region of contact between two neurons or between a neuron and a cell.
Synthetic biology. Cross-disciplinary branch of molecular biology using physics, computing, and chemistry to invent genomes, obtain new enzyme reactions, and create cells capable of novel functional and metabolic activities.
Theranostics. Contraction of therapy and diagnostics.
Thermoelectricity. Study of the relation between electrical and thermal phenomena.
Thesaurismosis. Accumulation of drugs, excipients, or materials in cells, bringing about cell death (iatrogenic effect).
Thiol. Organic compound carrying a sulfhydryl group –SH attached to a carbon atom.
Translocation. Transfer of nanoparticles across cell or tissue barriers. More commonly, genetic translocation is a genetic mutation characterised by mutual exchange of chromosome material between non-homologous chromosomes, i.e., not belonging to the same pair.
Triazole. Cyclic organic compound containing a five-atom ring with two double bonds and three nitrogen atoms, hence with formula C2H3N3.
Tribology. Science of friction, wear, and lubrication.
Trophic chain. Network of food chains connected together within an ecosystem and through which energy and biomass circulate.
TUNEL assay. Method for detecting cells undergoing apoptosis.
Ultrafine particle. Defined traditionally as a particle with diameter less than 0.1 mm.
Van der Waals force. Attractive force between closely spaced atoms and molecules (at nanometric distances or less).
Virus. Agent of infection requiring a host, often a cell, whose constituents it uses to replicate. It has a size in the range 10–300 nm.
Vortex. Rotating motion of fluid or particles.
Waveguide. Device for guiding electromagnetic or acoustic waves, confining them in a particular medium over a certain distance. An optical waveguide is usually obtained from a material with high refractive index inserted in one or more materials of lower index, e.g., an optical fibre.
Xenograft. Transplantation of a graft, e.g., a tumour, in which the donor belongs to a different biological species to the recipient.
Young's modulus. Constant relating the stress and strain for an isotropic elastic material.
