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3-Methoxy-4-phenoxybenzoyl group has been used for the protection of exocyclic amino group of nucleosides. In case of 2'-deoxycytidine it has been found to be highly selective under controlled conditions. The N-protected derivatives of 2'-deoxyadenosine and 2'-deoxyguanosine have been found to be sufficiently stable towards acids minimising depurination under conditions of synthesis of oligodeoxyribonucleotide on solid support via phosphotriester approach. The high lipophilicity of the group and milder deprotection conditions are additional advantages.  相似文献   
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Isozymic patterns of lactate dehydrogenase (E.C. 1.1.1.27) by polyacrylamide gel electrophoresis (PAGE) were observed in various categories of filariasis and controls, i.e. asymptomatic microfilaraemia and symptomatic amicrofilaraemia, endemic normal and non-endemic normal. Lactate dehydrogenase (LDH) activity was also observed amongst the above categories of patients. An increase in enzyme activity and change in the isozymic pattern was observed in the above categories of filaria infected serum. LDH activity doubled in asymptomatic microfilaraemia whereas in symptomatic amicrofilaraemia the increase in LDH activity was thirtyfold. The isozymic pattern of microfilaraemic cases showed the presence of three bands B4, A1B3, A2B2, which are quite thick as compared to normal healthy subjects, whereas the patients with symptomatic amicrofilaraemia showed marked elevation of serum LDH-4 or A3B1. The LDH was partially purified by combined treatment of (NH4)2SO4 fractionation and gel filtration. The isozymic pattern of purified LDH showed a similar pattern.  相似文献   
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DNA shuffling is a practical process for directed molecular evolution which uses recombination to dramatically accelerate the rate at which one can evolve genes. Single and multigene traits that require many mutations for improved phenotypes can be evolved rapidly. DNA shuffling technology has been significantly enhanced in the past year, extending its range of applications to small molecule pharmaceuticals, pharmaceutical proteins, gene therapy vehicles and transgenes, vaccines and evolved viruses for vaccines, and laboratory animal models.  相似文献   
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This paper is an analytical study on the pulse wave velocities in the aorta. In conformity to a physiologic state of loading, the distensibility of the vessel wall has been accounted for. The wall material is treated by using the theory of large elastic deformations. The orthotropicity of wall tissues and the effect of the surrounding tissues have been incorporated in the analysis which is based on the use of the strain energy function suggested by Vaishnavet al. Numerical values of the wave velocities of the canine middle descending thoracic aorta are computed by using the derived analytical expressions.  相似文献   
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Summary The concentration, uptake and element use efficiency of N, P and K in one C3 annual (Polypogon monspeliensis) and two C4 (Echinochloa colonum, an annual, andDichathium annulatum, a perennial) grasses were determined during winter and summer seasons in monocultures raised in field plots at three moisture levels,viz. full, half and one-fourth of field capacity. At each moisture regime the plants were clipped thrice at moderate and severe levels corresponding to 40 and 80% of live green. The concentration of these elements was characteristic of the growth habit of these plants;e.g. the build up of concentration was maximum in leaf of the annuals while it was comparable in crown and leaf of Dichanthium. The N level was maximum in Polypogon. The nutrient use effiency was comparable in the two annuals and maximum K and N use were obtained in Polypogon and Dichanthium, respectively.  相似文献   
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