真空干燥球孢白僵菌纯孢粉的活孢率、毒力与贮存期

采用真空冷冻干燥法 (冻干 )和真空室温干燥法 (抽干 )对球孢白僵菌 (Beauveriabassiana)原菌粉进行了干燥工艺的比较。在固体产孢基质上生产的新鲜纯孢粉 (原菌粉 )含水量达 5 8 65 % ,经 36h冻干或抽干 ,孢子粉的含水量分别降至 3 97%和 4 2 6% ,含孢量分别为 1 2 9× 1 0 1 1 孢子 /g和 1 2 5× 1 0 1 1 孢子 /g ,活孢率分别为 99 0 %和 97 9%。冻干粉和抽干粉之间的活孢率无显著差异 ,但萌发速度不同。原菌粉、抽干粉及冻干粉对桃蚜(Myzuspersicae)在接种后第 7d的LC50 分别为 1 1 5 ,5 89和 2 95× 1 0 4 个孢子 /mL ;在 1 0 6 个孢子 /mL的剂量下对桃蚜的LT50 分别为 3 6d、 4 4d和 3 9d。从生产成本低得多 ,抽干法比冻干法在白僵菌纯孢粉的生产中更有应用前景 ,尽管冻干粉的质量略优于抽干粉。在4℃和 2 0℃下贮存冻干粉并进行为期一年的孢子萌发率和毒力检测。结果显示 ,冻干粉在2 0℃下贮存至 2 5 5d时完全失活而丧失染虫能力 ,而在 4℃下贮存一年后的活孢率仍达90 2 % ,LT50 仅从初始的 3 9d延长至 4 7d。这说明仅通过降低含水量以延长白僵菌孢子粉在常温下的贮存期仍是不可能的。     

现代生物技术引发的几点思考

现代生物技术正在改变着人类生活与思维方式,其发展有可能重新实现了人与自然的共存与进化,但也不可避免地产生生物战争、伦理道德、法律、社会、食品安全、工农业生产、能源、环境等一些新的问题,令人们深思。     

水洞沟的新年代测定及相关问题讨论

水洞沟是中国北方的一处独具特色的旧石器时代晚期遗址,在阐释区域性技术传统的成因、远古文化的发展和变异,以及晚更新世人类在东北亚的迁徙、扩散和交流具有重要的地位。本文报道在水洞沟2号地点发现的新材料和新的研究成果：野外考察发现系列的火塘遗迹并采集到石制品、骨器等文化遗物;系统的AMS^14C测年将水沿沟遗址的年代确定在距今29000-24000前;新的研究为探讨水洞沟工业的渊源和细石器技术的起源提供了珍贵的信息。     

杜仲药用有效成分提取方法研究

为优选杜仲的提取工艺条件 ,本实验以杜仲提取液中氯原酸的含量和浸膏得率为指标 ,采用四因素三水平正交设计法 ,筛选影响杜仲提取工艺的因素 ,探索最优的提取工艺条件。实验证明合理的提取方法为 :12倍 6 0 %的乙醇回流 3次 ,每次 2小时 ;所得杜仲提取物中氯原酸含量为 8 72mg/g生药 ,浸膏得率为 2 0 6 8%。     

基因芯片技术及其在植物上的应用

基因芯片技术（gene chip technology)是采用光导原位合成或缩微印刷等方法,将大量特定的DNA探针片段有序地固定于固相载体的表面,形成DNA微阵列,然后与待测的标记样品靶DNA或RNA分子杂交,对杂交信号进行扫描及计算机检测分析,从而获取所需的生物信息。该技术在植物研究中广泛应用于寻找特异性相关基因和新基因,基因表达分析,基因突变和多态性检测,DNA测序等。     

膜分离技术在硫酸软骨素分离方面的应用

介绍了硫酸软骨素的生产工艺 ,应用膜分离技术对现有工艺进行了改进 ,使硫酸软骨素纯度达 95 .2 % ,收率提高3% ,并且简化了操作     

蛇鮈属一新亚种记述

蛇(鱼句)属为一群小型鲤科鱼类.蛇(鱼句)广泛分布于东亚大陆.通过对采自云南程海和珠江、闽江、长江、辽河、松花江等水系蛇标本的形态、度量特征进行仔细分析和比较,认为蛇程海种群是蛇的1个新亚种,命名为程海蛇(Saurogobio dabryi chenghaiensis).程海蛇(鱼句)的特征为:吻皮发达,盖过上唇;上下唇布满发达的乳突;体及尾柄极细长,体高为体长的12.7%～15.0%,尾柄高为体长的5.5%～6.1%、为尾柄长的31.8%～39.1%;沿体侧中轴自鳃孔上方至尾鳍基具一浅色暗纹,其上布有6～11个大型棒状黑斑(黑斑长为宽的2～4倍);肛门位于腹鳍长度的中点之后;尾鳍最长鳍条为其最短鳍条的2倍以上;仅分布于云南程海.     

Ribosome display: cell-free protein display technology.

Ribosome display is a cell-free system for the in vitro selection of proteins and peptides from large libraries. It uses the principle of coupling individual nascent proteins (phenotypes) to their corresponding mRNA (genotypes), through the formation of stable protein-ribosome-mRNA (PRM) complexes. This permits the simultaneous isolation of a functional nascent protein, through affinity for a ligand, together with the encoding mRNA, which is then converted and amplified as DNA for further manipulation, including repeated cycles or protein expression. Ribosome display has a number of advantages over cell-based systems such as phage display; in particular, it can display very large libraries without the restriction of bacterial transformation. It is also suitable for generating toxic, proteolytically sensitive and unstable proteins, and allows the incorporation of modified amino acids at defined positions. In combination with polymerase chain reaction (PCR)-based methods, mutations can be introduced efficiently into the selected DNA pool in subsequent cycles, leading to continuous DNA diversification and protein selection (in vitro protein evolution). Both prokaryotic and eukaryotic ribosome display systems have been developed and each has its own distinctive features. In this paper, ribosome display systems and their application in selection and evolution of proteins are reviewed.     

Adaptive radiation and coevolution — pollination biology case studies

The impact of coevolutionary interaction between species on adaptive radiation processes is analysed with reference to pollination biology case studies. Occasional colonization of archipelagos can bring together coevolving partners and cause coradiation of the colonizing species, e.g. the drepanidids and the lobelioids on Hawaii. Permanent reciprocal selective pressure between pairs of coevolving species can lead to a coevolutionary race and rapid evolutionary change. This is exemplified by spurred flowers and long-tongued flower-visitors. The geographic patterning of diffuse coevolution systems can lead to dramatic changes in species interactions. In different populations, interaction between pollinating and seed-parasitizing Greya moths and their host plants varies from mutualism to commensalism and antagonism, depending on the presence of copollinators. Asymmetrical coevolution between angiosperms and oligolectic flower-visitors may facilitate rapid reproductive isolation of populations following a food-plant switch, if the oligoleges use their specific food plants as the rendezvous sites. Diffuse coevolution between angiosperm species and pollinating insects may cause frequent convergent evolution of floral traits such as nectar reward instead of pollen reward, floral guides, zygomorphic flowers, or mimicry of pollen signals, since the multiple plant species experience similar selective pressures via the coevolving partners. Patterns of angiosperm adaptive radiation are highlighted in the context of coevolution with pollinators.     

2003-2004年生物磁学研究和应用的新进展

本综述性论文开始写于 1 979年 ,其后每年撰写。每年撰写的内容包含 :①生物磁场 ;②磁场生物效应 ;③生物磁技术 ;④生物磁法研究 ;⑤生物磁应用