高稳定人胰岛素的晶体学研究:Ⅲ,A21-Asp突变体的结晶和初步晶体学分析

研究一系列有明确意义改性胰岛素的结构将有益于新型胰岛素分子的设计。经蛋白质工程制备的AspA21—人胰岛素(ADHI)基本保持了生物活力,而在酸性溶夜(pH3—4)中的稳定性比天然胰岛素在中性溶液中高5—10倍。本文报道ADHI的结晶、初步晶体学研究及中等分辨率衍射数据的收集。ADHI晶体属R3空间群:a_H=b_H=82.72埃,c_H=34.02埃。     

广西森林土壤丝状真菌的生态分布

真菌种类多,分布广,对人类的生产和生活关系非常密切,因此近来对真菌特别是丝状真菌的研究日益引起高度重视。1981—1990年我们对桂北龙胜县里骆林区、桂中宜山县庆远林区、桂南岑溪县七坪林区和桂西田林县老山林区森林土壤微生物区系进行了分析,其中丝状真菌是我们重点研究的内容之一。在上述森林土壤中共分离出丝状真菌2084株,经鉴定归属于25属。现将广西森林土壤丝状真菌生态分布的研究结果报道如下。     

大果木姜子的甘油三酯组成

采用光谱法和胰酯酶分解法对大果木姜子油酯中分得的结晶C—I组成进行了分析,结果表明C—I是由11种甘油三酯组成。其中2-位为月硅酸的甘油三酯占91.80％,1,3-位脂肪酸主要为癸酸和月桂酸,甘油三酯的组成中,CLC占62.24％,LLC占24.50％。     

双波长分光光度法测定肝素钠效价

本文介绍了在室温条件下,以天青作显色剂,用双波长分光光度法测定肝素钠的效价。本法快速准确,测定浓度0—20u/ml,相对误差在±4％以内,标准偏差0.19,变异系数2.5‰,与羊血浆法测定结果相差±4u/ml以内。     

光钳操纵生物活体的动态监测技术的研究

采用摄像、录像和视屏监控系统及显色偏振装置与光钳系统耦合,从空间分辨、色分辨和时间分辨多方面改善系统品质,实现了光钳捕获与操纵生物活体的动态监测、实时记录、资料保存和屏幕再现的功能,并能测量光钳操纵细胞的位移量和由此计算操纵速度,提高了光钳的自我调整和光钳操纵细胞的精细度。本研究为激光光钳技术在细胞工程等方面的应用研究提供了行之有效的技术手段。     

染色体辐射效应的微机检测 Ⅱ断片率 微核率与细胞畸变率间的相关性检测

本文继前文后,按照设计的线性回归程序在“IBM—PC/XT”微型计算机上,进一步检测了断片率、微核率与细胞畸变率之间的相关性,肯定了微核测定法,断片测定法可以替代染色体畸变分析法。     

茭白黑粉菌在茭白植株内形态发育的初步研究

茭白黑粉菌的菌丝体多年生,越冬期宿存于茭白地下茎中,翌年春天入侵由地下茎芽体形成的植株。菌丝具隔膜,分枝,细胞双核,在寄主细胞间隙并入侵细胞中生长,无吸器;受菌丝侵染的茭白地上茎薄壁细胞分裂增多,体积加大,并高度液泡化,使茎膨大。部分菌丝在茭白茎膨大后期菌丝壁胶化,原生质收缩成团,生成厚壁,形成冬孢子。     

The long-distance migration of Nilaparvata lugens (Stål) (Delphacidae) in China: radar observations of mass return flight in the autumn

Abstract.

• 1 A case study is presented of the autumn migration of the brown planthopper, Nilaparvata lugens (Stål), in the area of Nanjing in the People's Republic of China. The study was made using a high frequency (8 mm wavelength) radar and a net suspended from a kytoon.
• 2 The observations confirmed that long-distance return migrations occur in China in mid and late September, with N.lugens being carried on the prevailing north-easterly wind towards the autumn infestation and overwintering areas of the species.
• 3 After mass take-off in the late afternoon or at dusk, the migrants flew for several hours during the evening, often in a dense layer which formed at heights between about 400 and 1000m above ground. These layers often had well-defined ceilings corresponding to an air temperature of about 16°C. The migration height was above the top of the surface temperature inversion, i.e. the migrants did not fly at the height of the warmest air.
• 4 The dense layer concentrations overflying the radar were backtracked to source areas up to 240 km away in the north-east of Jiangsu Province. Planthoppers observed emigrating from the Nanjing area would reach areas in south Anhui Province or north Jiangxi Province if they flew for 12 h.
• 5 There was a second period of mass take-off at dawn. Insect layers sometimes formed but did not last longer than 1–2h.
• 6 The present results were strikingly different from those previously observed in the dry season in the Philippines, where migratory flight durations were largely confined to periods of about 30min at dusk and dawn.
• 7 Our observations are discussed in relation to the equator-wards return migrations undertaken in autumn by other insect species, and the importance of these migrations for the maintenance of long-flying genotypes in the overwintering populations is considered.