Synthesis and Some Biological Properties of Carbon-Bridged Cyclonucleosides and Their Phosphates

Abstract

Methods for the synthesis of carbon-bridged 6,5′-, 6,6′-, 6,3′-, and 6,2′-cyclopyrimidine and 8,2′-cycloadenine nucleosides and some of their phosphates are described. The 6,5′- and 6,6′-cyclouridine 2′,3′-cyclic phosphates were the substrates and their 3′-phosphates were strong inhibitors of pancreatic ribonuclease.     

绣球菌生物学特性若干问题的研究

绣球菌菌丝在蛋白胨培养基中生长最佳,硫酸铵、尿素、复合肥对菌丝生长有抑制作用。选用基础培养基或在基础培养基中添加0.3%蛋白胨作为绣球菌母种培养基较为合适。栽培料中添加淀粉可促进绣球菌的生长,接种50d后观察发现,添加新鲜去皮马铃薯块比马铃薯淀粉效果好,前者100%菌袋出现原基,后者只有50%菌袋出现原基,且原基正处在胶质片时期。添加大米淀粉,小麦淀粉效果与马铃薯块接近,甘薯淀粉与马铃薯淀粉效果接近。     

An Electrokinetic Interpretation of the Functioning of Biological Systems and its Application to the Study of Mineral Salts Absorption

An attempt has been made to apply an electrokinetic approachto describe the functioning of biological systems. Using anohmic expression, it is possible to construct models as effectiveas those of Michaelis-Menten kinetics to interpret experimentaldata. While retaining the notions of competitive and non-competitiveinteractions it replaces the parameters K_m and V_m by log (B/[P])and A/r which have simple biological meanings. In addition,the approach is well adapted to the analysis of problems presentedby complex systems working in series or parallel, coupled systemsand networks of reactions. By the use of a non-ohmic expressionthe electrokinetic approach attributes a semi-conductor-likecomponent to catalytic systems in the cell. The approach isconsistent with the data of quantum mechanics and it predictsthe existence of a third type of interaction, perhaps equivalentto allosteric interactions. Applied to the problem of absorptionit leads to an explanation of experimental results without thenecessity of invoking the presence of two carrier systems.     

不同水域刀鲚的若干生物生态学特性比较研究

比较分析了不同水域刀鲚的分类地位,生殖洄游时间、路线和所需外界条件以及其分布现状和资源状况。同时,于2015年对鄱阳湖、赣江和抚河下游的刀鲚进行了现场调查,并与1982年采自鄱阳湖的刀鲚标本进行了生物学特性比较。研究发现,1982年鄱阳湖短颌鲚(定居型刀鲚)体长范围为5.0~30.0 cm,优势组体长为6~20 cm,体重范围是0.90~105.08 g;2015年调查的短颌鲚体长范围为11.6~28.0 cm,优势组体长为11~20 cm,体重范围为5.99~81.31 g。1982年鄱阳湖洄游型刀鲚占总尾数的3.86%,体长范围为15.0~33.0 cm,体重范围为10.24~151.63 g;而2015年调查的洄游型刀鲚仅占总尾数的0.97%,体长范围是25.5~28.0 cm,体重范围是60.62~78.00 g。结果分析表明,江西上述水域均以短颌鲚为主,洄游型刀鲚难已形成渔汛。