| polar plates | Condensed platelike bodies at the ends of the spindle during mitosis of certain types of cells. (05 Mar 2000) |
|---|---|
| polar presentation | The presentation of either pole of the foetal oval; may be either a cephalic or breech presentation, or a longitudinal lie. (05 Mar 2000) |
| polar ring | A thickened, electron-dense ring at the anterior end of certain stages of the Apicomplexa; part of the apical complex characteristic of these sporozoans. (05 Mar 2000) |
| polar solvents | Solvent's that exhibit polar forces on solutes, due to high dipole moment, wide separation of charges, or tight association; e.g., water, alcohols, acids. (05 Mar 2000) |
| polar star | One of the figures forming the diaster. Synonym: polar star. (05 Mar 2000) |
| polar zone | The region in the vicinity of an electrode applied to the body. See: electrotonus. (05 Mar 2000) |
| electro-polar | <physics> Possessing electrical polarity; positively electrified at one end, or on one surface, and negatively at the other; said of a conductor. Source: Websters Dictionary (01 Mar 1998) |
| zinco-polar | <physics> Electrically polarized like the surface of the zinc presented to the acid in a battery, which has zincous affinity. Source: Websters Dictionary (01 Mar 1998) |
| law of polar excitation | A given segment of a nerve is irritated by the development of catelectrotonus and the disappearance of anelectrotonus, but the reverse does not hold; i.e., excitation occurs at the cathode when the circuit is closed and at the anode when it is opened. Synonym: Pfluger's law. (05 Mar 2000) |
| acylmercaptan bond | A high energy bond formed by the condensation of a carboxyl group (-COOH) and a mercaptan (or thiol) group (-SH); widely formed in the course of intermediary metabolism, notably in the oxidation of fats, where the -SH is part of coenzyme A and the -COOH is part of the fatty acid being oxidised. (05 Mar 2000) |
| apolar bond | <chemistry> The attractive force between molecules due to the close positioning of non-hydrophilic portions of the two molecules. (09 Oct 1997) |
| bond | 1. That which binds, ties, fastens,or confines, or by which anything is fastened or bound, as a cord, chain, etc.; a band; a ligament; a shackle or a manacle. "Gnawing with my teeth my bonds in sunder, I gained my freedom." (Shak) 2. The state of being bound; imprisonment; captivity, restraint. "This man doeth nothing worthy of death or of bonds." 3. A binding force or influence; a cause of union; a uniting tie; as, the bonds of fellowship. "A people with whom I have no tie but the common bond of mankind." (Burke) 4. Moral or political duty or obligation. "I love your majesty According to my bond, nor more nor less." (Shak) 5. A writing under seal, by which a person binds himself, his heirs, executors, and administrators, to pay a certain sum on or before a future day appointed. This is a single bond. But usually a condition is added, that, if the obligor shall do a certain act, appear at a certain place, conform to certain rules, faithfully perform certain duties, or pay a certain sum of money, on or before a time specified, the obligation shall be void; otherwise it shall remain in full force. If the condition is not performed, the bond becomes forfeited, and the obligor and his heirs are liable to the payment of the whole sum. 6. An instrument (of the nature of the ordinary legal bond) made by a government or a corporation for purpose of borrowing money; as, a government, city, or railway bond. 7. The state of goods placed in a bonded warehouse till the duties are paid; as, merchandise in bond. 8. The union or tie of the several stones or bricks forming a wall. The bricks may be arranged for this purpose in several different ways, as in English or block bond (Fig. 1), where one course consists of bricks with their ends toward the face of the wall, called headers, and the next course of bricks with their lengths parallel to the face of the wall, called stretchers; Flemish bond (Fig.2), where each course consists of headers and stretchers alternately, so laid as always to break joints; Cross bond, which differs from the English by the change of the second stretcher line so that its joints come in the middle of the first, and the same position of stretchers comes back every fifth line; Combined cross and English bond, where the inner part of the wall is laid in the one method, the outer in the other. 9. <chemistry> A unit of chemical attraction; as, oxygen has two bonds of affinity. It is often represented in graphic formulae by a short line or dash. See Diagram of Benzene nucleus, and Valence. Arbitration bond. See Arbitration. Bond crediter, a debt contracted under the obligation of a bond. Bond (or lap) of a slate, the distance between the top of one slate and the bottom or drip of the second slate above, i. E, the space which is covered with three thicknesses; also, the distance between the nail of the under slate and the lower edge of the upper slate. Bond timber, timber worked into a wall to tie or strengthen it longitudinally. Synonym: Chains, fetters, captivity, imprisonment. Origin: The same word as band. Cf. Band, Bend. Source: Websters Dictionary (01 Mar 1998) |
| bond angle | This refers to the angle formed between two nuclei which are linked together. (09 Oct 1997) |
| bond dissociation energy | This is the energy needed to break the bonds between two linked atoms. (09 Oct 1997) |
| bond energy | The energy needed to break a molecular bond. (09 Oct 1997) |