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   214篇
  免费   22篇
  2022年   2篇
  2021年   5篇
  2018年   6篇
  2017年   6篇
  2016年   5篇
  2015年   6篇
  2014年   7篇
  2013年   12篇
  2012年   13篇
  2011年   11篇
  2010年   10篇
  2009年   4篇
  2008年   9篇
  2007年   7篇
  2006年   12篇
  2005年   9篇
  2004年   8篇
  2003年   6篇
  2002年   7篇
  2001年   5篇
  2000年   9篇
  1999年   3篇
  1998年   3篇
  1997年   4篇
  1996年   3篇
  1995年   2篇
  1994年   3篇
  1993年   2篇
  1992年   3篇
  1991年   8篇
  1990年   2篇
  1989年   3篇
  1988年   3篇
  1987年   1篇
  1986年   3篇
  1985年   5篇
  1984年   3篇
  1983年   4篇
  1982年   2篇
  1981年   3篇
  1980年   2篇
  1978年   2篇
  1977年   1篇
  1976年   4篇
  1975年   1篇
  1974年   2篇
  1973年   1篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有236条查询结果,搜索用时 15 毫秒
231.
232.
233.
234.
Neurons and gla from the central nervous system of the adult teleost Carassius auratus have been grown as explant cultures of minced brain tissue and as trypsin dissociated cells. These cultures exhibit extensive neurite growth from two neuronal types, have organotypic ultrastructure, and contain electrically active cells. Autoradiographic data indicate that these neurons do not divide in culture, and histological evidence suggests that some mature neurons survive explantation and regenerate processes. However, explantation of brain fragments not containing undifferentiated cells, localized in the ventricular and subventricular zones in the brains of fish, resulted in mesenchymal and glial cell cultures only. Therefore, a contribution to the population of cells in culture by undifferentiated cells must be considered. The cultured neurons remained viable for at least 19 weeks and ultrastructural and electrophysiological data indicate synaptic interaction between cells in explant cultures.  相似文献   
235.
BackgroundExperimental treatments for Ebola virus disease (EVD) might reduce EVD mortality. There is uncertainty about the ability of different clinical trial designs to identify effective treatments, and about the feasibility of implementing individually randomised controlled trials during an Ebola epidemic.ConclusionsThe MSA discards ineffective treatments quickly, while reliably providing evidence concerning effective treatments. The MSA is appropriate for the clinical evaluation of EVD treatments.  相似文献   
236.
In the Adriatic Sea, the correlation between mucilage phenomena and the presence of Gonyaulax fragilis (Schütt) Kofoid (Dinophyta) has been recently demonstrated. The application of PCR-based methods and the development of species-specific molecular probes might represent powerful technologies for rapid and specific monitoring of microalgal species in seawater samples. Here, we report sequencing of the small subunit (SSU) ribosomal RNA gene (18S rDNA) of G. fragilis and its comparative analysis within the Dinophyta. Total DNAs were extracted and amplified from cultured cells of G. fragilis, which were isolated from natural phytoplanktonic association in the northern Adriatic Sea. Total 18S rDNA gene was amplified using 16S1N and 16S2N primers and sequenced using ad hoc designed internal primers. The primers amplified a product of expected size (length 1700/1800 bp). The phylogenetic analysis carried out by comparing G. fragilis sequence to homologous sequences of Lingulodinium polyedrum (Stein) Dodge, Gonyaulax spinifera (Claparède et Lachmann) Diesing, Protoceratium reticulatum (Claparède et Lachmann) Bütschli revealed a great nucleotide divergence of G. fragilis SSU sequence. Therefore, the SSU sequence could be used as species-specific marker for the identification of this mucilage producer microalga. In addition, such sequence could be used as target to design oligonucleotide probes for the construction of DNA microchips as diagnostic tool for the routine monitoring of harmful algae in seawater. An erratum to this article is available at .  相似文献   
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