Insulin clearance during hypoglycemia in patients with insulin-dependent diabetes mellitus.

Eight male patients with insulin-dependent diabetes mellitus (IDDM) without residual beta-cell function were studied on two occasions in random order. In one experiment hypoglycemia was induced by a constant rate iv infusion of insulin (0.034 U/kg/h) during 150 minutes. At the other occasion an identical infusion of insulin was given, but this time euglycemia was maintained by a variable iv infusion of glucose. Plasma levels of free insulin were almost identical during the two experiments indicating that insulin clearance is not influenced by hypoglycemia in patients with IDDM.     

Phylogenetic analysis and evolution of RNase P RNA in proteobacteria.

The secondary structures of the eubacterial RNase P RNAs are being elucidated by a phylogenetic comparative approach. Sequences of genes encoding RNase P RNA from each of the recognized subgroups (alpha, beta, gamma, and delta) of the proteobacteria have now been determined. These sequences allow the refinement, to nearly the base pair level, of the phylogenetic model for RNase P RNA secondary structure. Evolutionary change among the RNase P RNAs was found to occur primarily in four discrete structural domains that are peripheral to a highly conserved core structure. The new sequences were used to examine critically the proposed similarity (C. Guerrier-Takada, N. Lumelsky, and S. Altman, Science 246:1578-1584, 1989) between a portion of RNase P RNA and the "exit site" of the 23S rRNA of Escherichia coli. Phylogenetic comparisons indicate that these sequences are not homologous and that any similarity in the structures is, at best, tenuous.     

稻—萍—鱼系统中红萍氮素吸收利用及有效性研究

本文报道以红萍为饵料,鱼类对红萍氮素消化吸收、转化情况。试验结果表明:草鱼和尼罗罗非鱼对红萍氮素的消化和吸收率约为60％,其中30％红萍氮素转化为鱼体动物蛋白,另外约30％氮素排出体外。在田间条件下,尼罗罗非鱼摄食红萍,每季平均增长率约为41—40％。稻田养鱼,以萍喂鱼,鱼粪肥田,萍体氮素得以吸收利用,效益明显。在稻萍鱼体系中,当季红萍氮素的总利用率可达45—50％,而红萍单作肥料处理其利用率仅为30—36％,第二季作物对红萍残留氮素回收率可达7.83—9.64％,比红萍单作肥料处理高3.33—4.11％。第二季残效明显优于红萍压施处理,晚季稻谷产量的增产率可达13—25％,比压施红萍作肥料处理高7—8％。     

溶液流动对等电溶菌酶晶体生长的影响

本文对等温自由生长和强制性溶液生长的等电溶菌酶的晶体形态进行了研究,发现这些形态变化与溶液相的流动密切相关,指出生物晶体生长停止是由于生长晶体周围的溶质贫乏造成的;通过某些手段减薄或消除这一溶质贫乏区,就可以保证晶体的持续生长。本文的研究对改善大尺寸晶体的生长提供了一条途径。     

井冈山杜鹃花属植物种类的调查

井冈山杜鹃花属植物有18个种,其中井冈山特有分布种1个,江西新分布种2个;海拔400—1700m均有分布。井冈山杜鹃(Rhododendron jinggangshanicum)是井冈山的特有分布种,花大色艳,有很高的园林观赏价值和药用价值。