| AE | above-elbow [amputation]; acrodermatitis enteropathica; activation energy; adult erythrocyte; advers... |
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| CIE | Canberra interview for the elderly; cellulose ion exchange; counter-current immunoelectrophoresis; c... |
| DCX | double charge exchange |
| e | base of natural logarithms, approximately 2.7182818285; egg transfer; ejection; electric charge; ele... |
| ET | educational therapy; effective temperature; ejection time; embryo transfer; endothelin; endotoxin; e... |
| pulmonary gas exchange | The exchange of oxygen and carbon dioxide between alveolar air and pulmonary capillary blood. (12 Dec 1998) |
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| sister chromatid exchange | An aberrant crossing-over event in which there is an exchange of segments between the sister chromatids of a chromosome, either between the sister chromatids of a meiotic tetrad or between the sister chromatids of a duplicated somatic chromosome. It can be induced by ultraviolet and ionizing radiation or by mutagenic agents and is observed by autoradiography. (12 Dec 1998) |
| needle-exchange programs | Organised services for exchange of sterile needles and syringes used for injections as a potential means of reducing the transmission of infectious diseases. (12 Dec 1998) |
| international educational exchange | The exchange of students or professional personnel between countries done under the auspices of an organization for the purpose of further education. (12 Dec 1998) |
| ion exchange | Reversible chemical reaction between a solid, often an ion exchange resin, and a fluid whereby ions may be exchanged from one substance to another. This technique is used in water purification, in research, and in industry. (12 Dec 1998) |
| ion exchange resin | <chemistry> A resin of polymers that havefixed charged groups which is used in chromatographic columns to separate ions. (27 Oct 1998) |
| ion exchange resins | <chemistry> High molecular weight, insoluble polymers which contain functional groups that are capable of undergoing exchange reactions (ion exchange) with either cations or anions. See: ion exchange, ion exchanger. (12 Dec 1998) |
| exchange | 1. To part with give, or transfer to another in consideration of something received as an equivalent; usually followed by for before the thing received. "Exchange his sheep for shells, or wool for a sparking pebble or a diamond." (Locke) 2. To part with for a substitute; to lay aside, quit, or resign (something being received in place of the thing with); as, to exchange a palace for cell. "And death for life exchanged foolishly." (Spenser) "To shift his being Is to exchange one misery with another." (Shak) 3. To give and receive reciprocally, as things of the same kind; to barter; to swap; as, to exchange horses with a neighbor; to exchange houses or hats. "Exchange forgiveness with me, noble Hamlet." (Shak) Synonym: To barter, change, commute, interchange, bargain, truck, swap, traffic. Origin: Cf.OF. Eschangier, F. Echanger. See Exchange. 1. The act of giving or taking one thing in return for another which is regarded as an equivalent; as, an exchange of cattle for grain. 2. The act of substituting one thing in the place of another; as, an exchange of grief for joy, or of a scepter for a sword, and the like; also, the act of giving and receiving reciprocally; as, an exchange of civilities or views. 3. The thing given or received in return; especially, a publication exchanged for another. 4. The process of setting accounts or debts between parties residing at a distance from each other, without the intervention of money, by exchanging orders or drafts, called bills of exchange. These may be drawn in one country and payable in another, in which case they are called foreign bills; or they may be drawn and made payable in the same country, in which case they are called inland bills. The term bill of exchange is often abbreviated into exchange; as, to buy or sell exchange. A in London is creditor to B in new York, and C in London owes D in New York a like sum. A in London draws a bill of exchange on B in New York; C in London purchases the bill, by which A receives his debt due from B in New York. C transmits the bill to D in New York, who receives the amount from B. 5. A mutual grant of equal interests, the one in consideration of the other. Estates exchanged must be equal in quantity, as fee simple for fee simple. 6. The place where the merchants, brokers, and bankers of a city meet at certain hours, to transact business. In this sense often contracted to 'Change. Arbitration of exchange. See Arbitration. Bill of exchange. See Bill. Exchange broker. See Broker. Par of exchange, the established value of the coin or standard of value of one country when expressed in the coin or standard of another, as the value of the pound sterling in the currency of France or the United States. The par of exchange rarely varies, and serves as a measure for the rise and fall of exchange that is affected by the demand and supply. Exchange is at par when, for example, a bill in new York, for the payment of one hundred pounds sterling in London, can be purchased for the sum. Exchange is in favor of a place when it can be purchased there at or above par. Telephone exchange, a central office in which the wires of any two telephones or telephone stations may be connected to permit conversation. Synonym: Barter, dealing, trade, traffic, interchange. Origin: OE. Eschange, eschaunge, OF. Eschange, fr. Eschangier, F. Echanger, to exchange; pref. Ex- out + F. Changer. See Change, and cf. Excamb. Source: Websters Dictionary (01 Mar 1998) |
| exchange transfusion | Removal of most of a patient's blood followed by introduction of an equal amount from donors. Synonym: exsanguination transfusion, substitution transfusion, total transfusion. (05 Mar 2000) |
| exchange transfusion, whole blood | Repetitive withdrawal of small amounts of blood and replacement with donor blood until a large proportion of the blood volume has been exchanged. Used in treatment of foetal erythroblastosis, hepatic coma, sickle cell anaemia, disseminated intravascular coagulation, septicaemia, burns, thrombotic thrombopenic purpura, and fulminant malaria. (12 Dec 1998) |
| absorption chromatography | <investigation> Techniques for separating molecules based on differential absorption and elution. Term for separation methods involving flow of a fluid carrier over a nonmobile absorbing phase. (18 Nov 1997) |
| adsorption chromatography | Chromatography in which separation of substances is achieved by the difference in degree of adsorption of the compounds to a stationary phase. (05 Mar 2000) |
| affinity chromatography | <investigation> A technique of analytical chemistry used to separate and purify a biological molecule from a mixture, based on the attraction of the molecule of interest to a particular ligand which has been previously attached to a solid, inert substance. The mixture is passed through a column containing the ligand attached to the stationary substance, so that the molecule of interest stays within the column while the rest of the mixture continues through to the end. Then, a different chemical is flushed through the column to detach the molecule from the ligand and bring it out separately from the rest of the mixture. (09 Feb 1998) |
| gas chromatography | <technique> A chromatographic technique (a type of column chromatography) in which the stationary phase is solid while the mobile phase is gaseous samples. The gaseous samples are separated based on their different adsorption ability to the solid phase. (09 Oct 1997) |
| gas-liquid chromatography | <technique> A chemistry lab technique, a type of column chromatography, used to separate the components of a mixed substance. The substance is held stationary by an inert solid coated with an inert liquid which is not likely to evaporate (i.e. Is nonvolatile), while a gas (called an eluant) flows past it bringing out the components one at a time. (09 Oct 1997) |