Biomedical subjects

C M Krishna

Publications and source records attributed to C M Krishna.

38 records · Page 3Linked to original sources

PubMed1986

Sensitized photo-oxidation of thymidine by 2-methyl-1,4-naphthoquinone. Characterization of the stable photoproducts.

The near ultraviolet photolysis of an aerated aqueous solution of thymidine containing 2-methyl-1,4-naphthoquinone gives rise to two main classes of photoproducts as a result of the initial formation of a pyrimidine radical cation. These photo-oxidation products have been separated by high performance liquid chromatography and further characterized by various spectroscopic techniques including fast atom bombardment mass spectrometry and high field 1H and 13C nuclear magnetic resonance analysis. This photoreaction constitutes an excellent model to study the chemical properties of the thymidine radical cation which is expected to be one of the primary consequences of the direct effects of ionizing radiation.

Oxidation-Reduction↗

PubMedDate not supplied

In vitro evaluation of ceramometal bond strength in anterior metal ceramic crowns with and without palatal coverage of porcelain.

This in vitro study compared the load necessary to cause porcelain bond failure on porcelain covering the labial and palatal surfaces compared with porcelain covering only labial surface in metal ceramic crowns of maxillary anterior teeth. 30 metal ceramic crowns for maxillary central incisor tooth were fabricated in two groups (Groups A and Group B) (15 samples in each group). In group A, palatal ceramo-metal junction was placed at cervical 1/5th of palatal surface. In Group B the palatal ceramo-metal junction was placed at palato incisal line angle and these crowns were subjected to load using Instron testing machine. Mean failure load for group A is statistically highly significant than Group B. (P value = 0.0025). But both these values are higher than the reported mean maximal incising forces.

Bite Force↗