全文获取类型
收费全文 | 1401588篇 |
免费 | 153822篇 |
国内免费 | 962篇 |
出版年
2018年 | 13429篇 |
2017年 | 12785篇 |
2016年 | 18156篇 |
2015年 | 24506篇 |
2014年 | 28737篇 |
2013年 | 41537篇 |
2012年 | 46260篇 |
2011年 | 47090篇 |
2010年 | 31848篇 |
2009年 | 29225篇 |
2008年 | 41183篇 |
2007年 | 42377篇 |
2006年 | 39938篇 |
2005年 | 38468篇 |
2004年 | 37911篇 |
2003年 | 36484篇 |
2002年 | 35322篇 |
2001年 | 61127篇 |
2000年 | 61502篇 |
1999年 | 49070篇 |
1998年 | 17982篇 |
1997年 | 18726篇 |
1996年 | 17519篇 |
1995年 | 16445篇 |
1994年 | 15933篇 |
1993年 | 16001篇 |
1992年 | 40882篇 |
1991年 | 39756篇 |
1990年 | 38692篇 |
1989年 | 37711篇 |
1988年 | 35181篇 |
1987年 | 33257篇 |
1986年 | 31006篇 |
1985年 | 30961篇 |
1984年 | 25966篇 |
1983年 | 22026篇 |
1982年 | 16941篇 |
1981年 | 15213篇 |
1980年 | 14428篇 |
1979年 | 24383篇 |
1978年 | 19111篇 |
1977年 | 17472篇 |
1976年 | 16137篇 |
1975年 | 17810篇 |
1974年 | 19074篇 |
1973年 | 18846篇 |
1972年 | 17047篇 |
1971年 | 15579篇 |
1970年 | 13361篇 |
1969年 | 12905篇 |
排序方式: 共有10000条查询结果,搜索用时 515 毫秒
941.
Five cases of coincident salmonellosis and ulcerative colitis are described. In three the diagnostic combination was recognized late. If corticosteroid therapy is given for the colitis once the combination is recognized, then simultaneous systemic antibiotic cover is advisable. One of the five patients died during corticosteroid therapy alone with salmonella septicaemia due to a usually non-invasive organism. 相似文献
942.
943.
A. J. Edwards J. D. Hamilton W. D. Nichol G. W. Taylor A. M. Dawson 《BMJ (Clinical research ed.)》1970,1(5692):342-345
Seven patients with “coeliac axis compression syndrome” are reported. Five were treated surgically, but only two did well. A survey of 200 healthy adults showed epigastric bruits in 6·5%; only one of these had dyspepsia, though dyspepsia was present in 12·5% overall.Caution is urged in attributing a causal relationship between coeliac axis compression and pain and in proceeding to arteriography when compression is suspected on clinical grounds. 相似文献
944.
945.
946.
T S Il'ina 《Genetika》1986,22(11):2572-2582
The published data on molecular mechanisms of transposons movement inside and between genomes are reviewed. The replicative mechanism of transposition of the family of Tn3-like elements is discussed, as well as the modes of bacteriophage Mu, Tn9, Tn10, Tn903 transposition. The factors affecting the choice of transposition pathways are analysed. 相似文献
947.
948.
949.
Pieces of brain are fixed in formalin ammonium bromide for about 4 days at room temperature, and given the following treatment: After washing, dehydrating and clearing, embed in paraffin, section and mount. Deparaffinize sections and pass through graded alcohols to water. Sensitize in 5% sodium sulfite for 2 hours, wash in distilled water and impregnate with silver diamminohydroxide solution 2-5 minutes at room temperature. Reduce in 2% formalin, wash in distilled water and tone in gold chloride. Fix in 5% hypo, counterstain with 1% picric acid, dehydrate and cover in balsam. Equally good results are obtained by impregnating with Hortega's strong silver carbonate. The microglia, oligodendroglia, fibrous and protoplasmic astrocytes in the cat, rabbit, newborn and adult human are successfully stained by this method. 相似文献
950.