Showing papers on "Nanomedicine published in 1999"

Nanomedicine, Volume I: Basic Capabilities

Abstract: ion — specific removal of bonded atom from a structure. A reaction that removes an atom from a structure. AC — alternating current. Accommodation — voluntarily thickening the lens of the eye to focus diverging rays of light from nearby objects on the fovea of the retina; visual focusing on nearby objects. Acellular — cell-free. Acetylcholine — a chemical neurotransmitter. Acetylcholinesterase — enzyme that rapidly degrades acetylcholine. Acidophilic — acid-loving. Acoustomechanical conversion — conversion of acoustic energy into mechanical energy. Action potential — complete sequence of electrical events accompanying and following the nerve impulse. Active site — the restricted part of a protein to which a substrate binds. Adduct — in chemistry, an addition product or complex; in biomechanics, to draw together physically separated components. Adiabatic — change in pressure or volume without loss or gain of heat. Adipocyte — fat cell. Adipose — fatty; pertaining to fat. ADP — adenosine diphosphate; has one energy-rich phosphate bond. Adrenergic — activated or energized by adrenalin (epinephrine). Adsorption — attachment of a substance to the surface of another material. Aerobic — needing oxygen to live or function. Aerobots (aerobotics) — aerial (flying) robots. Afferent — in relation to nerves or blood vessels, conducting toward structure or organ; carrying impulses toward a center, as when sensory nerves carry sensory information toward the brain or spinal cord. Affinity (constant) — the strength of the binding of a ligand to a receptor, or the reciprocal of the dissociation rate constant; a measure of the binding energy of a ligand in a receptor; the greater the affinity, the more securely the receptor binds the ligand. AFM — see Atomic Force Microscope. Aft — toward the rear. Agglutinin — an antibody present in the blood that attaches to antigens, such as those found on the surfaces of red blood cells, causing them to clump together; agglutinins cause transfusion reactions when blood from a different group is given. Agonist — in pharmacology, a drug which binds to a receptor and thus stimulates the receptor’s function, possibly mimicking the body’s own regulatory function. Compare antagonist. Albumin — one of a group of simple proteins widely distributed in plant and animal tissues. ALC — airborne lethal concentration. Algorithm — in general, a formula or set of rules for solving a particular problem; in medicine, a set of steps used in diagnosing and treating a disease. Alimentary — pertaining to the digestive tract. Nanomedicine • Volume I 398 Alimentography — a physical description (and mapping) of the human alimentary canal. Aliquot — a portion obtained by dividing the whole into equal parts without a remainder; loosely, any one of two or more samples of something, of the same volume or weight. Alkali — strongly basic substance, especially the metal hydroxides, usually associated with the alkali metals (e.g. sodium and potassium). Allele — one of several alternative forms of a gene occupying a given locus on paired chromosomes. Alloantigen — a substance present in certain individuals that stimulates antibody production in other members of the same species, but not in the original donor. See also antiserum. Allometric scaling laws — in biology, scaling laws that involve a biological variable that is an exponential function of the mass of the organism. Allosteric control — the ability of an interaction at one site of a protein to influence the activity of another site. Allotropic — pertains to the existence of a chemical element or compound in two or more distinct forms with different physical and chemical properties (e.g. diamond and graphite are allotropes of C). Alphanumeric — able to contain both alphabetic and numeric characters. Alveolus (alveolar) — in anatomy, a small cell or cavity; a saclike dilation. Most commonly, a small air sac found at the lowest levels of the branching tube system comprising the lungs. AM — amplitude modulation. Amide — a molecule containing an amine bonded to a carboxyl group (e.g. CONH2). Amide bonds link amino acids in peptides and proteins. Amine — a molecule containing N with a single bond to C and two other single bonds to H or C (but not an amide); the amine group or moiety (e.g. -NH2). Amino acid — a molecule containing both an amine and a carboxylic acid group; there are 20 genetically encoded amino acids in biology. Amniotic — pertaining to the amnion (the innermost of the fetal membranes). Amphipathic — molecular structures which have two surfaces or ends, one of which is hydrophilic and the other of which is hydrophobic. Lipids are amphipathic, and some protein regions may form amphipathic helices with one charged face and one neutral face. Anabolism — the constructive phase of metabolism and the opposite of catabolism; in anabolism, a cell takes from the blood the substances required for repair and growth, building them into a cytoplasm, thus converting nonliving material into the living cytoplasm of the cell. Anaerobic — able to live or function without oxygen. Analgesia — absence of normal sense of pain. Analog — pertaining to data measurable and representable through continuously variable physical quantities. Compare digital. Anaphase — the phase of mitosis (cell division) beginning with centromere division and the movement of chromosomes away from the metaphase plate toward opposite spindle poles. Anaphylactoid-type reaction — a physiological response similar to anaphylaxis. Anaphylaxis — the immediate transient kind of immunologic (allergic) reaction characterized by contraction of smooth muscle and dilation of capillaries due to release of pharmacologically active substances (e.g. histamine, bradykinin, serotonin, etc.); a powerful allergic response. Anaphylaxis is classically initiated by the combination of antigen (allergen) with mast cell-fixed, cytophilic antibody (chiefly IgE immunoglobulin), but can also be initiated by relatively large quantities of serum aggregates (antibody-antigen complexes, and other) that seemingly activate complement leading to production of anaphylatoxin. Anastomose — to open one structure into another directly or by connecting channels, usually said of blood vessels, lymphatics, and hollow viscera; to unite by means of an anastomosis, or a connection between formerly separate structures. AND gate — a logical gate that returns a high (1) output if and only if both input signals are high (1). See bit. Anergic — unresponsive. Aneutronic — without neutrons. Angioedema — a condition characterized by development of urticaria (hives) and edematous (swollen with excessive fluid) areas of skin, mucous membranes, or viscera. Angiogenesis — growth of new blood vessels, especially capillaries. Anion — a negatively charged ion. Anisotropic — not isotropic. Anode — the positive pole of an electrical source. ANS — see autonomic nervous system. Antagonist — in pharmacology, a drug that prevents receptor function. Compare agonist. Anterior — the front of the human body, on or nearest the abdominal surface; the front of something. Anteroinferior — in front and below. Basic Capabilities • Glossary 399 Anteroposterior — passing from front to rear. Anthropogenic — caused by human activity. Antibody — a protein (immunoglobulin) produced by B-lymphocyte cells that recognizes a particular foreign antigen, thus triggering the immune response. Antigen — any molecule or foreign substance that, when introduced into the body, provokes synthesis of an antibody, thus stimulating an immune response. Antiserum — serum that contains demonstrable antibody or antibodies specific for one (monovalent) or more (polyvalent) antigens. Aorta — the largest artery in the human body, leading away from the heart. Apheresis — removal of blood from an individual patient, separating certain elements (e.g. red cells, platelets, white cells) for use elsewhere, and reintroducing the remaining components into the patients; also known as cytapheresis, hemapheresis, leukapheresis, pheresis, and plasmapheresis, depending on the type of cells being harvested. Apical — pertaining to the apex (e.g. the point of a cone) of a structure. Apoptosis — an orderly disintegration of eukaryotic cells into membrane-bound particles that may then be phagocytosed by other cells. Aqueous humor — transparent liquid contained in the anterior chamber of the eyeball in front of the lens. Aromatic compounds — in chemistry, ring or cyclic compounds related to benzene, many having a fragrant odor. Arrhythmia — irregularity or loss of rhythm, especially of the heartbeat. Arteriovenous — relating to both arteries and veins. Artery — in anatomy, a blood vessel that sends blood to the tissues from the heart. Aseptic — characterized by the absence of living pathogenic organisms; a state of sterility. Asperities — protruding elements of roughness on a surface, e.g., burrs or spurs. Asphyxia — condition of hypoxia caused by insufficient oxygen intake. Assembler — see molecular assembler. Asymptotic — in geometry and mathematics, a curve that approaches closer and closer, but never quite reaches, another curve or line. Asynchronous —not synchronized in time. atm — atmosphere, a unit of pressure; mean air pressure at Earth’s surface is 1 atmosphere (~1.01 x 10 N/m). Atomic Force Microscope (AFM) — an instrument that uses atomic forces between a sample and a sharp scanning needle tip to image surfaces to molecular accuracy by mechanically probing their surface contours; the AFM measures the tiny upward and downward motions of the tip as the tip is dragged over the surface, producing an atomic-resolution topographic map of the surface. The AFM has also been used to physically manipulate individual molecules. Atom laser — a laserlike device that uses beams of coherent atoms rather than photons. ATP — adenosine triphosphate; has two energy-rich phosphate bonds. Auscultation — the process of listening for sounds w