人工合成草鱼生长激素cDNA在大肠杆菌中的表达

经密码子优化的人工合成草鱼生长激素ｃＤＮＡ与表达载体ｐＥＴ－２８ａ（＋）重组，构建重组表达质粒ｐＥＴ－ＧＨ。转化大肠杆菌ＢＬ２１（ＤＥ３），筛选阳性克隆，ＩＰＴＧ诱导表达。１２．５％的ＳＤＳ－ＰＡＧＥ分析显示，大肠杆菌表达产物中含有与草鱼生长激素分子量一致的新增蛋白带，激光密度扫描，其产量约占菌体总蛋白的４０％。金属离子螯合层析柱亲和纯化，获得电泳纯的重组蛋白。Ｗｅｓｔｅｒｎ－ｂｌｏｔｔｉｎｇ和酶联免疫吸附受体法检测证实：重组蛋白与抗草鱼生长激素的多克隆抗体发生特异性结合；复性后的重组蛋白有与天然草鱼生长

秦岭西段鱼类多样性现状初报

对秦岭西段汉江水系和嘉陵江水系的鱼类和环境调查显示 ,人类活动对鱼类多样性产生了较大的影响。本文试图对该地区鱼类多样性丧失的现状加以报道并对原因进行分析。以前该地区鱼类共有 142种 ,本次调查的渔获物中只有 34种。鱼类物种资源的减少是多种因素造成的 :水坝的修建使得鱼类栖息地环境改变从而导致鱼类的种类和种群数量变化 ,水污染、过度捕捞和非法渔业也在一定程度上破坏了鱼类物种多样性。

揭开武汉东湖蓝藻水华消失之谜

水华（亦称湖靛）是湖泊富营养化最恶劣的表征之一。武汉东湖７０年代至１９８４年间每年夏季出现蓝藻水华，１９８５年起突然消失，至今已有１４年没有重现，原因何在？通过三次设在湖里的围隔试验，证明鲢鳙的大量放养，是水华消失的决定性因素。文章报道了三次原地围隔试验的情况，结合东湖鲢鳙生物量的鱼群探测仪记录，指出鲢鳙的放养密度达到每立方米水（即１ｔ有鱼５０ｇ）（即市制１两）时，就能控制蓝藻水华的发生。文章还对治理水体富营养化的流行学说—生物操纵论进行了评论。

鱼类病原菌耐药质粒的研究概况

鱼类病原菌耐药质粒的研究概况李爱华王伟俊（中国科学院水生生物研究所，武汉４３００７２自５０年代起，许多国家仿照畜牧业上的做法，广泛使用化学治疗药物来防治鱼类疾病。其后果不可避免地导致耐药菌的出现。早在１９５７年，美国就观察到由耐磺胺药的Ａｅｒｏｍｏｎ...

Nonlinear analysis of cardiac rhythm fluctuations using DFA method

An approach by which the detrented fluctuation analysis (DFA) method can be used to help diagnose heart failure was demonstrated. DFA was applied to patients suffering from congestive heart failure (CHF) to check correlations between DFA indices and CHF, and determine a correlation between DFA indices and mortality, with a particular attention to the residue parameter, which is a measure of the departure of the DFA from its power law approximation. DFA parameters proved to be useful as a complement to the physiological parameters weber and FE to sort out the patients into three prognostic group.

中国自由生活线虫新记录(色矛目、嘴刺目和窄咽目)

本文报道淡水、土壤自由生活线虫国内新记录11种，即：田园素矛线虫Achromadoraruricola，半棘素矛线虫Achromadorasemiarmata,叉齿烙线虫Ironusdentifurcatus，好逸烙线虫Ironusignavus，亲邻三孔线虫Tripylaaffinis，球形三孔线虫Tripylaglomerans，谢氏小三孔线虫Tripylinasheri,墙根绕线虫Plectusparietinus,似疑绕线虫Plectusinquirendus,愁容筒咽线虫Cylindrolaim

中国金藻门植物的新种类

<正> 囊壳花瓶形,长16～19μm,宽5～7μm。中间呈椭圆形,前端收缢呈领状,领口向外开展呈漏斗形,后端渐尖成长尾刺。常附生在浮游的绿球藻类细胞表面,单个或多个,呈丛状。原生质体几乎充满整个囊壳,活跃变形,前端常伸出囊壳。鞭毛单条,伸展向前,约与身长相等;色素体缺如。

土壤藻类及其生理生态

<正> 人类对土壤藻类的认识至少可以追溯到三千多年前的我国诗经时代。Prescott引用Porterfield的研究并阐述说:尽管藻类学作为一门科学是由西方文化中诞生的,但最早的文字记载出现在中国的古典著作中,在诗经中人们可以发现采集和食用念珠藻(Nostoc)的文献记录……。他们还提到,古希腊的贤哲对念珠藻也有过观察。但是,尽管十七、十八世纪前后在我国和欧洲对土壤藻类都有了较细微的描述性记录,如我国明代科学

鱼腥藻细胞外膜完整性与防氧的关系

暴露鱼腥藻7120(Anabaena 7120)细胞于膜扰乱剂EDTA或Tris(pH 8.0,37℃,5—10分钟),导致细胞释放外膜脂多糖和蛋白成分。Tris处理后,细胞对结晶紫和洗涤剂(SDS,Triton X-100)的敏感性增加,整细胞碱性磷酸酶活性增强,暗示外膜结构被修饰,透过性增大;与此同时,被处理细胞固氮酶活性在空气氧中大大降低,而在厌氧条件下活性不受影响。将细胞释放物质与处理后的细胞重组时,可明显恢复固氮活性,表明外膜结构与固氮防氧保护有密切关系。EDTA处理的细胞,虽然释放的脂多糖和蛋

Exploring an effective model of new product development in medical devices: A knowledge cluster approach

This study proposes a new product development (NPD) model that aims to improve the effectiveness of innovative NPD in the medical devices. By adopting open innovation theory and applying an in-depth investigation methodology, this paper proposes a knowledge cluster that improves the integration of interdisciplinary human resources and enhances the acquirement of innovative technologies. A knowledge cluster approach helps gather, organise, synthesise, and accumulate knowledge in order to become the impetus for innovation. Although enterprises are no longer the principals of research and development, they should still be capable of integrating professional physicians, external groups, and individuals through the knowledge cluster platform. However, in order to support an effective NPD model, enterprises should provide adequate incentives and trust to external individuals or groups willing to contribute their expertise and knowledge to this knowledge cluster platform. Copyright © 2013 Inderscience Enterprises Ltd.

Low-cost high-efficiency GaN LED on large-area si substrate

The use of large size Si substrates for epitaxy of nitride light emitting diode (LED) structures has attracted great interest because Si wafers are readily available in large diameter at low cost. In addition, such wafers are compatible with existing processing lines for the 6-inch and larger wafer sizes commonly used in the electronics industry. With the development of various methods to avoid wafer cracking and reduce the defect density, the performance of GaN-based LED and electronic devices has been greatly improved. In this paper, we review our methods of growing crack-free InGaN-GaN multiple quantum well (MQW) LED structures of high crystalline quality on Si(111) substrates. The performance of processed LED devices and its dependence on the threading dislocation density were studied. Full wafer-level LED processing using a conventional 6-inch III-V processing line is also presented, demonstrating the great advantage of using large-size Si substrates for mass production of GaN LED devices.

An exploration of risk management in global industrial investment

This article explores risk management in global industrial investment by identifying linkages and gaps between theories and practices. It identifies opportunities for further development of the field. Three related bodies of literature have been reviewed: risk management, global manufacturing and investment. The review suggests that risk management in global manufacturing is overlooked in the literature; that existing theoretical risk management processes are not well developed in the global manufacturing context and that the investment literature applies mainly to financial risk assessment rather than investment risk management structures. Further, there appears to be a serious lack of systematic industrial risk management in investment decision making. This article highlights the opportunities to deploy current good practices more effectively as well as the need to develop more robust theories of industrial investment risk management. The approach adopted to investigate this multidisciplinary topic included a historical review of literature to understand the diverse background of theoretical development. A case study research approach was adopted to collect data, involving four global manufacturing companies and one risk management advisory company to observe the patterns and rationale of current practices. Supporting arguments from secondary data sources reinforced the findings. The research focuses risk management in global industrial investment. It links theories with practice to understand the existing knowledge gap and proposes key research themes for further research. © 2013 Macmillan Publishers Ltd. 1460-3799 Risk Management.

武昌的秀体溞

<正> 秀体溞(Diaphanosoma)是枝角类栉足族仙达溞科(Sididae)中包括种类最多的一个属,根据已往的记录,共计约有20种。关于我国秀体溞的计载,总共只有7种。最早是由 Spandl 在广东记述了镰角秀体溞(D.excisum Sars)一种。上野益三曾发表过有关我国枝角类的文章多篇,他报告了浙江、四川、台湾、黑龙江、吉林以及内蒙古等地的秀体溞共有6种,即:短尾秀体溞[D.brachyurum(Liévin)],长肢秀体溞

Immunoglobulin joining (J) chain and its expression in the Chinese soft-shelled turtle (Pelodiscus sinensis)

The immunoglobulin (Ig) joining (J) chain plays an important role in the formation of polymeric Igs and their transport into secretions. In the present study, the cDNA sequence of J chain has been cloned from the Chinese soft-shelled turtle (Pelodiscus sinensis) by reverse transcription (RT)-PCR and rapid amplification of cDNA ends (RACE). The cDNA sequence is 2347 bp in length and contains an open reading frame of 480 bp encoding 160 aa including the signal sequence. The deduced amino acid sequence has a high degree of homology with that of an already reported turtle J chain (80.7%), and of chicken (71.3%). By using real-time quantitative RT-PCR analysis, a significant up-regulation of J-chain transcripts was observed in spleen, kidney and blood of turtles injected with inactivated Aeromonas hydrophila, indicating the immune role of J chain in response to bacterial infection. (C) 2009 Elsevier B.V. All rights reserved.