| AaPCO2, (A-a)PCO2 | alveolo-arterial carbon dioxide tension difference |
|---|---|
| AaPO2, (A-a) PO2 | alveolo-arterial oxygen tension difference |
| ATS | Achard-Thiers syndrome; acid test solution; alpha-D-tocopherol acid succinate; American Thoracic Soc... |
| CTH | ceramide trihexoside; chronic tension headache; cystathionase |
| HT | Hashimoto thyroiditis; hearing test; hearing threshold; heart; heart transplantation, heart transpla... |
| arch length deficiency | The difference between the available circumference of the dental arch and that required to accommodate the succedaneous teeth in proper alignment. (05 Mar 2000) |
|---|---|
| available arch length | <dentistry> The amount of space available for the permanent teeth around the dental arch from the first permanent molar on the left to the first permanent molar on the right. (05 Mar 2000) |
| back focal length | <microscopy> As measured on the principal axis, from the second lens vertex to the back focal point of the lens. It is not the equivalent of the focal length. (05 Aug 1998) |
| bellows length | <microscopy> The distance from the eye point to the image plane in a photomicrographic apparatus. (05 Aug 1998) |
| bond length | This is the distance between the nuclei of two atoms which have formed bonds with each other. (09 Oct 1997) |
| required arch length | The sum of the mesiodistal widths of the permanent teeth from first permanent molar to first permanent molar. (05 Mar 2000) |
| resting length | The length at rest from which a muscle develops maximum isometric tension. (05 Mar 2000) |
| restriction fragment length polymorphism | <molecular biology, technique> A method that allows familial relationships to be established by comparing the characteristic polymorphic patterns that are obtained when certain regions of genomic DNA are amplified (typically by PCR) and cut with certain restriction enzymes. The variation in the length of DNA fragments produced by a restriction endonuclease that cuts at a polymorphic locus. Such variations are generated by mutations that create or abolish recognition sites for these enzymes. This is a key tool in DNA fingerprinting, reflecting the existence of different alleles in the individual. Restriction fragment length polymorphism mapping is also used in plant breeding to see if a key trait such as disease resistance is inherited. In principle, an individual can be identified unambiquously by restriction fragment length polymorphism hence the use of restriction fragment length polymorphism in forensic analysis of blood, hair or semen). Similarly, if a polymorphism can be identified close to the locus of a genetic defect, it provides a valuable marker for tracing the inheritance of the defect. Synonym: DNA fingerprinting. Acronym: RFLP (12 Jan 1998) |
| restriction length polymorphism | Fragment length polymorphism, the existence of allelic forms recognizable by the length of fragments that result when the nucleotide chain is treated by a specific restriction enzyme that cleaves wherever a particular sequence of nucleotides occurs. A mutation in this sequence changes cleaving and hence the number of fragments. (05 Mar 2000) |
| greatest length | Measurement from the cranial to caudal end of the embryo prior to folding. (05 Mar 2000) |
| positive focal length | <microscopy> Any lens which converges parallel rays to a focus at the back of the lens is a positive lens and has a positive focal length. The focal length is measured from the second principal point of the lens to the point on the lens axis where the rays from an infinitely distant point are brought to focus. See: negative focal length. (05 Aug 1998) |
| crown-heel length | Length of an outstretched embryo or foetus from skull vertex to heel. See: Streeter's developmental horizon(s). (05 Mar 2000) |
| crown-rump length | In utero measurement corresponding to the sitting height (crown to rump) of the foetus. Length is considered a more accurate criterion of the age of the foetus than is the weight. The average crown-rump length of the foetus at term is 36 cm. (12 Dec 1998) |
| height-length index | The relation of the height to the length of the skull: (height × 100)/length. Synonym: height-length index, length-height index, transversovertical index. (05 Mar 2000) |
| spinal length | A measurement from the distal surface of the embryo where the plane passes through the developing eye (this is the cranial limit of the spinal cord) down to the rump. (05 Mar 2000) |