首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   151篇
  免费   9篇
  2021年   7篇
  2020年   1篇
  2018年   1篇
  2017年   2篇
  2016年   3篇
  2015年   2篇
  2014年   2篇
  2013年   3篇
  2012年   5篇
  2011年   5篇
  2010年   1篇
  2009年   6篇
  2008年   6篇
  2007年   5篇
  2006年   5篇
  2005年   2篇
  2004年   7篇
  2003年   7篇
  2002年   6篇
  2001年   5篇
  2000年   4篇
  1999年   3篇
  1998年   11篇
  1997年   7篇
  1996年   4篇
  1993年   2篇
  1992年   4篇
  1991年   3篇
  1990年   2篇
  1989年   3篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1984年   3篇
  1982年   2篇
  1980年   3篇
  1978年   1篇
  1977年   3篇
  1976年   5篇
  1973年   2篇
  1972年   2篇
  1971年   1篇
  1961年   1篇
  1960年   2篇
  1958年   1篇
  1956年   1篇
  1952年   1篇
排序方式: 共有160条查询结果,搜索用时 15 毫秒
151.

Background  

Although carbohydrates are the third major class of biological macromolecules, after proteins and DNA, there is neither a comprehensive database for carbohydrate structures nor an established universal structure encoding scheme for computational purposes. Funding for further development of the Complex Carbohydrate Structure Database (CCSD or CarbBank) ceased in 1997, and since then several initiatives have developed independent databases with partially overlapping foci. For each database, different encoding schemes for residues and sequence topology were designed. Therefore, it is virtually impossible to obtain an overview of all deposited structures or to compare the contents of the various databases.  相似文献   
152.
153.
154.
155.
Background

The integration of biotechnology into chemical manufacturing has been recognized as a key technology to build a sustainable society. However, the practical applications of biocatalytic chemical conversions are often restricted due to their complexities involving the unpredictability of product yield and the troublesome controls in fermentation processes. One of the possible strategies to overcome these limitations is to eliminate the use of living microorganisms and to use only enzymes involved in the metabolic pathway. Use of recombinant mesophiles producing thermophilic enzymes at high temperature results in denaturation of indigenous proteins and elimination of undesired side reactions; consequently, highly selective and stable biocatalytic modules can be readily prepared. By rationally combining those modules together, artificial synthetic pathways specialized for chemical manufacturing could be designed and constructed.

Results

A chimeric Embden-Meyerhof (EM) pathway with balanced consumption and regeneration of ATP and ADP was constructed by using nine recombinant E. coli strains overproducing either one of the seven glycolytic enzymes of Thermus thermophilus, the cofactor-independent phosphoglycerate mutase of Pyrococcus horikoshii, or the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase of Thermococcus kodakarensis. By coupling this pathway with the Thermus malate/lactate dehydrogenase, a stoichiometric amount of lactate was produced from glucose with an overall ATP turnover number of 31.

Conclusions

In this study, a novel and simple technology for flexible design of a bespoke metabolic pathway was developed. The concept has been testified via a non-ATP-forming chimeric EM pathway. We designated this technology as “synthetic metabolic engineering”. Our technology is, in principle, applicable to all thermophilic enzymes as long as they can be functionally expressed in the host, and thus would be potentially applicable to the biocatalytic manufacture of any chemicals or materials on demand.

  相似文献   
156.
157.
Effects of astroglia on the morphological and biochemical differentiation of catecholamine neurons from embryonic rat mesencephalon were studied in vitro, and compared to results obtained with fibroblasts. Neurite outgrowth and complexity were measured using computer-assisted morphometry on tyrosine hydroxylase immunoreactive neurons growing on preformed monolayers of astrocytes or fibroblasts. The morphological differentiation of these neurons was stimulated by the presence of astrocytes, and this effect was evident in various cellular compartments, including the size of the cell soma, length of neurites and neuritic segments, and the numbers of these segments. Tyrosine hydroxylase activity was measured biochemically in these cultures and was also found to be stimulated by the presence of astroglial monolayers. The implication of these results for the understanding of specific neuron-glial interactions during embryonic brain development is discussed.Special issue dedicated to Dr. Paola S. Timiras  相似文献   
158.
Dr. Helmut Lieth 《Planta》1960,54(6):555-576
Ohne ZusammenfassungMit 9 Textabbildungen  相似文献   
159.
160.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号