全文获取类型
收费全文 | 424128篇 |
免费 | 44032篇 |
国内免费 | 196篇 |
专业分类
468356篇 |
出版年
2016年 | 4637篇 |
2015年 | 6140篇 |
2014年 | 7237篇 |
2013年 | 10867篇 |
2012年 | 11797篇 |
2011年 | 12232篇 |
2010年 | 8324篇 |
2009年 | 7658篇 |
2008年 | 10941篇 |
2007年 | 11599篇 |
2006年 | 10935篇 |
2005年 | 10405篇 |
2004年 | 10469篇 |
2003年 | 10227篇 |
2002年 | 10034篇 |
2001年 | 17393篇 |
2000年 | 17417篇 |
1999年 | 14091篇 |
1998年 | 5033篇 |
1997年 | 5324篇 |
1996年 | 5048篇 |
1995年 | 4760篇 |
1994年 | 4658篇 |
1993年 | 4654篇 |
1992年 | 12293篇 |
1991年 | 12088篇 |
1990年 | 12106篇 |
1989年 | 11876篇 |
1988年 | 11188篇 |
1987年 | 10514篇 |
1986年 | 9838篇 |
1985年 | 10256篇 |
1984年 | 8473篇 |
1983年 | 7299篇 |
1982年 | 5636篇 |
1981年 | 5053篇 |
1980年 | 4718篇 |
1979年 | 8103篇 |
1978年 | 6317篇 |
1977年 | 5960篇 |
1976年 | 5685篇 |
1975年 | 6147篇 |
1974年 | 6709篇 |
1973年 | 6588篇 |
1972年 | 6126篇 |
1971年 | 5543篇 |
1970年 | 4774篇 |
1969年 | 4786篇 |
1968年 | 4456篇 |
1967年 | 3808篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
Using a slide culture technique, it was determined unequivocally that the chlamydospore of Candida albicans does germinate. The germination was by way of a multiple-budding process which was associated mostly with young spores following their transfer to a fresh environment. It is concluded the chlamydospore of C. albicans is a reproductive cell with a transient viability. 相似文献
943.
944.
Isolation of Temperature-Sensitive Membrane Mutants of Escherichia coli K-12 总被引:1,自引:1,他引:0
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Johan F. Steenbakkers J. H. F. F. Broekman A. Kerkenaar P. G. De Haan 《Journal of bacteriology》1973,116(2):535-540
Mutants with impaired biosynthesis of unsaturated fatty acids or altered metabolism of the phospholipids were isolated at a rather high frequency from a set of temperature-sensitive lysis mutants. It is suggested that preselection for the lysis phenotype makes it possible to isolate several kinds of mutants affected in the integrity of the cytoplasmic membrane. 相似文献
945.
946.
947.
948.
V Cavallari A Maiorana M C Maiorana R A Fano S Scimone G P Trentini 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》1991,13(2):123-131
A morphometric study of subcellular structures in human primary breast tumors (of the ductal infiltrating type) and their synchronous lymph node metastases was carried out using planimetry and stereology. Each primary neoplasm was compared separately with its axillary metastatic growth in order to detect differences in the quantitative estimates of their subcellular components. A set of 24 morphometric parameters was used to quantitatively describe each neoplastic cell profile. Although some subcellular parameters showed significant differences between the cells of a primary tumor and its metastases, no parameter was found to be consistently altered in all cases. No consistent increase or decrease in the values of the affected parameters was observed in the metastases. More than being due to the expression of a biologically variant (more-or-less differentiated) metastatic phenotype, the differences in stereologic parameters detected in metastatic cells appear to reflect the existence of different functional states of the same cell type. 相似文献
949.
950.
A. Verrips Gerry C. H. Steenbergen-Spanjers J. A. F. M. Luyten R. A. Wevers John H. J. Wokke Fons J. M. Gabreëls Bert G. Wolthers Lambert P. W. J. van den Heuvel 《Human genetics》1997,100(2):284-286
We report a new mutation in the sterol 27-hydroxylase (CYP 27) gene in a Dutch family with cerebrotendinous xanthomatosis:
a G→A transition in the splice donor site in intron 4. This mutation leads to skipping of exon 4, resulting in a loss of 66
amino acids in the CYP 27 enzyme molecule.
Received: 15 March 1997 / Accepted: 26 March 1997 相似文献