全文获取类型
收费全文 | 242609篇 |
免费 | 148505篇 |
国内免费 | 29633篇 |
出版年
2018年 | 4076篇 |
2016年 | 4395篇 |
2015年 | 4428篇 |
2014年 | 5276篇 |
2013年 | 6424篇 |
2012年 | 7357篇 |
2011年 | 8344篇 |
2010年 | 8153篇 |
2009年 | 12795篇 |
2008年 | 8550篇 |
2007年 | 8709篇 |
2006年 | 7340篇 |
2005年 | 7110篇 |
2004年 | 7201篇 |
2003年 | 6673篇 |
2002年 | 7413篇 |
2001年 | 12384篇 |
2000年 | 10377篇 |
1999年 | 12685篇 |
1998年 | 10430篇 |
1997年 | 10502篇 |
1996年 | 9697篇 |
1995年 | 9844篇 |
1994年 | 9237篇 |
1993年 | 8955篇 |
1992年 | 12460篇 |
1991年 | 12588篇 |
1990年 | 13180篇 |
1989年 | 12475篇 |
1988年 | 11480篇 |
1987年 | 10379篇 |
1986年 | 9487篇 |
1985年 | 9140篇 |
1984年 | 7186篇 |
1983年 | 5955篇 |
1982年 | 5283篇 |
1981年 | 4743篇 |
1980年 | 4673篇 |
1979年 | 6287篇 |
1978年 | 5346篇 |
1977年 | 5003篇 |
1976年 | 4653篇 |
1975年 | 4746篇 |
1974年 | 5275篇 |
1973年 | 5190篇 |
1972年 | 5351篇 |
1971年 | 4886篇 |
1970年 | 4364篇 |
1969年 | 4295篇 |
1968年 | 3832篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
71.
72.
A A Gureeva A V Sanin V O Rybin N S Barteneva I A Lapaeva 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1986,(5):63-66
Effect of B. pertussis lymphocytosis-promoting factor (LPF) on the lympho-hematopoietic system of mice was studied. The injection of LPF was shown to sharply enhance endogenous colony formation and to induce a severe depletion of thymus cells, reaching its maximum of day 4. Thymocytes obtained on day 2 or 3 after the injection of LPF produced a suppressive effect on endogenous colony formation. The proliferative activity of hematopoietic stem cells sharply increased under the influence of LPF, though it had no radioprotective action. On the following day after the injection of LPF a steep rise in the number of hematopoietic stem cells was observed in the blood of mice: their content increased 20-fold in comparison with the control level. These data may be important for the evaluation of the side effects of pertussis vaccine on the lympho-hematopoietic system. 相似文献
73.
L I Kulikova G A Iatskiavichiute V S Tsvetkov Iu E Ershikova S P Gordienko 《Biulleten' eksperimental'no? biologii i meditsiny》1987,104(8):224-226
Antibodies to calcitonin, parathyroid hormone and cortisol are detected in acute stage of infection-caused bronchial asthma. The appearance of antibodies is paralleled by marked hypercalcaemia. The antibodies may bind excessive hormones in the blood, preventing further hormonal imbalance. Ten-day treatment with glucocorticoids decreased the amount of antibodies possibly due to normalization of hormonal secretion and restoration of their balance. As a result, calcium blood levels returned to normal. 相似文献
74.
75.
76.
The selective action of the antibiotics chloramphenicol and cycloheximide on the synthesis of ferredoxin in liquid cultures of Chlamydomonas reinhardii was studied. Highly specific antibodies raised against Chlamydomonas ferredoxin were used to determine the in vivo synthesis of apoferredoxin and conversion into native protein. The results indicate that 80S ribosomes are involved in the synthesis. Chlamydomonas cells growing in the absence of iron did not synthesize immunologically detectable amounts of ferredoxin. We suggest that this is based upon feed-back inhibition of apoferredoxin synthesis at the translational level.Abbreviations CAP
chloramphenicol
- CHI
cycloheximide
- IgG
Immunoglobulin G
- PBS
140.4 mM NaCl. 9 mM Na2HPO4, 1.3 mM NaH2PO4 (pH 74)
- SDS
sodium dodecvl sulphate
- Fd
Ferredoxin
- apoFd
Apoferredoxin
- CM-Fd
Scarboxymethylated Fd
- TCA-Fd
Fd treated with trichloroacetic acid 相似文献
77.
78.
79.
Properties of a transient current (Icont) believed to reflect a conformational change of the Na-Ca exchanger molecules after Ca2+ binding were investigated. Intracellular Ca2+ concentration jumps in isolated cardiac myocytes were generated with flash photolysis of caged Ca2+ dimethoxynitrophenamine, and membrane currents were simultaneously measured using the whole-cell variant of the patch-clamp technique. A previously unresolved shallow voltage dependence of Icont was revealed after developing an experimental protocol designed to compensate for the photoconsumption of the caged compound. This voltage dependence can be interpreted to reflect the distribution of Na-Ca exchanger conformational states with the Ca2+ binding site exposed to the inside of the cell immediately before the flash. Analysis performed by fitting a Boltzmann distribution to the observed data suggests that under control conditions most exchanger molecules reside in states with the Ca2+ binding site facing the outside of the cell. Dialysis of the cytosol with 3',4'-dichlorobenzamil, an organic inhibitor of the Na-Ca exchange, increased the magnitude of Icont and changed the voltage dependence, consistent with a parallel shift of the charge/voltage curve. This shift may result from intracellular DCB interfering with an Na(+)-binding or Na(+)-translocating step. These observations are consistent with Icont arising from a charge movement mediated by the Na-Ca exchanger molecules after binding of Ca2+. 相似文献
80.
Epstein-Barr virus transformation of human B lymphocytes despite inhibition of viral polymerase. 总被引:3,自引:3,他引:0
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Epstein-Barr virus transformed human lymphocytes despite the presence of up to 500 microM acyclovir [9-(2-hydroxyethoxymethyl)guanine], a viral DNA polymerase inhibitor. The transformed cells contained multiple Epstein-Barr virus genome copy numbers. Functional viral DNA polymerase is probably not required for cell transformation and the initial amplification of the viral genome. 相似文献