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为了将研发优势成果在大生产中保持,找到研发与大生产的衔接的最大化,最终找到最适合培养条件下的最优良菌种。以金霉素的产生菌金色链丝菌为研究对象,采用摇瓶培养与发酵罐培养两种发酵条件,从影响产生菌的各个因素出发,探讨多年来一直困扰生产的一个问题,即:研发出来的菌种摇瓶发酵水平很高,但进入大生产推广阶段后,发酵水平却不突出、不稳定,甚至逐渐滑坡。以期提高发酵水平,达到产能最大化。 相似文献
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青霉素经历了多年的工业发展,以其良好的疗效低廉的价格在抗生素生产领域中占有重要的地位,青霉素G钾工业盐是青霉素的重要部分.供生产罐直接使用的菌种一般为生产种子,生产种子质量的优劣可影响发酵50%的成功率.为了提高青霉素G钾工业盐成品的质量降低成本,应筛选优良菌种. 相似文献
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为了提高α-蒎烯产量,探索其发酵生产的规律,以α-蒎烯产生菌重组大肠杆菌YJM28为供试菌株,发酵周期24h作为发酵条件进行590 ml厌氧摇瓶发酵。最终采用基于Logistic和Luedeking-Piret等方程的供试菌株的菌体生长、产物合成以及底物消耗三个发酵动力学模型,最终确定菌体生长动力学模型为力学模型,说明上述三个模型能够较好的真实的描述供述菌株在在发酵过程中菌体生长、产物合成以及底物消耗的情况。 相似文献
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《中国科技纵横》2013,(24):25-25
专利号：ZL201120219422．X当前的零用药液,如眼药水、碘酒等有着潜在危险,即从开始使用时就会进入空气,致使药液逐步失效,不仅浪费资源而且危害人体健康。灵活方便、高效安全的吊水器,用无弹性软袋盛放药液,可以有效改善上述情况,又因软袋无弹性,可以保证药液内不进入空气,使其处于真空保存状态。另外,将药液注入人体的力量也是靠弹簧夹的压力或给气囊冲气所产生的压力,患者在输液时可自由行走,冬天还可以把药液袋放在被窝里或揣在怀里,当然也可把药液软袋放在温水盆里,靠弹簧夹在压力把药液送入人体,而药液从始至终都不接触空气,所以极其方便灵活又安全高效;也可将药液软袋放在气囊内,靠向气囊内充气所产生的压力把药液送入人体。 相似文献
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青霉素G钾工业盐是氨苄青霉素及头孢类抗生素的原料药,青霉素发酵属单一纯菌种发酵,在发酵过程中,培养液中的溶解氧浓度CL高于菌体的C长临时,菌体的呼吸不受影响,青霉菌的各种代谢活动不受干扰;如果培养液中的CL低于菌体的C长临时,菌体的多种生化代谢就要受到影响,严重时会产生不可逆的抑制菌体生长和产物合成异常现象,所以溶解氧对生长菌的代谢过程及最终产物的生物合成起着绝定性的作用,详细阐述了梅特勒O2-Sensor溶氧电极在青霉素G发酵过程中的应用对青霉素发酵过程起着重要的指导意义。 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
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Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
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Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献