全文获取类型
收费全文 | 687325篇 |
免费 | 64579篇 |
国内免费 | 850篇 |
出版年
2018年 | 11696篇 |
2017年 | 11105篇 |
2016年 | 12468篇 |
2015年 | 12209篇 |
2014年 | 14476篇 |
2013年 | 19799篇 |
2012年 | 24809篇 |
2011年 | 28861篇 |
2010年 | 20093篇 |
2009年 | 18322篇 |
2008年 | 24981篇 |
2007年 | 26821篇 |
2006年 | 20425篇 |
2005年 | 19606篇 |
2004年 | 19765篇 |
2003年 | 18847篇 |
2002年 | 18395篇 |
2001年 | 26474篇 |
2000年 | 26241篇 |
1999年 | 20657篇 |
1998年 | 7486篇 |
1997年 | 7314篇 |
1996年 | 6973篇 |
1995年 | 6580篇 |
1994年 | 6248篇 |
1993年 | 6224篇 |
1992年 | 16845篇 |
1991年 | 16951篇 |
1990年 | 16633篇 |
1989年 | 16144篇 |
1988年 | 14982篇 |
1987年 | 14169篇 |
1986年 | 13374篇 |
1985年 | 13324篇 |
1984年 | 10934篇 |
1983年 | 9358篇 |
1982年 | 6894篇 |
1981年 | 6112篇 |
1980年 | 5801篇 |
1979年 | 10224篇 |
1978年 | 8145篇 |
1977年 | 7313篇 |
1976年 | 6930篇 |
1975年 | 8122篇 |
1974年 | 8910篇 |
1973年 | 8677篇 |
1972年 | 8286篇 |
1971年 | 7685篇 |
1970年 | 6189篇 |
1969年 | 6103篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
991.
L A Shcherbakova V V Kalashnikov Iu S Tatarinov V A Murashov D D Petrunin 《Biulleten' eksperimental'no? biologii i meditsiny》1987,103(5):606-607
It has been found that fertility alpha 2-microglobulin content in male and female serum does not exceed 20 ng/ml and 40 ng/ml, respectively. A high level of fertility alpha 2-microglobulin was found in the serum in early pregnancy, with its concentration decreased by parturition. 相似文献
992.
E. I. Domaratskaya E. I. Bueverova O. D. Payushina V. I. Starostin 《Biology Bulletin》2005,32(3):216-220
Effect of alkylating agent dipin was studied on hematopoietic (CFU-S) and stromal (CFU-F) progenitor cells. Single administration of dipin (0.06 mg/g) to adult (CBA × C57Bl/6) F1 hybrid mice induced a long-term (2 years) oscillations in the numbers of day 7 CFU-S and day 11 CFU-S in the bone marrow and spleen. Dipin also damaged the hematopoietic stroma as indicated by decreased numbers of CFU-F which remained low for at least a year. The capacity of stromal cells to form ectopic hematopoietic foci was considerably decreased and also remained low for 10 months. The obtained data suggest high dipin sensitivity of the earliest hematopoietic and stromal cells. The dynamics of CFU-S numbers in the hematopoietic organs supports their functioning on the basis of clonal succession (Kay, 1965).__________Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 3, 2005, pp. 267–272.Original Russian Text Copyright © 2005 by Domaratskaya, Bueverova, Payushina, Starostin. 相似文献
993.
994.
J. L. Meers 《The Annals of applied biology》1978,89(1):143-145
995.
The potential impact of frog diseases on basic research is discussedin practical terms. 相似文献
996.
997.
998.
Acetylcholine, oxotremorine and carbachol, compounds that exhibit muscarinic agonist activity, maximally inhibited basal prolactin secretion from GH3 cells by approx. 50% and intracellular cyclic AMP levels by approx. 20%. Both parameters were inhibited with similar potencies by each agonist. These inhibitory effects were blocked by a muscarinic but not by a nicotinic receptor antagonist. In the presence of VIP or IBMX, which raise intracellular cyclic AMP levels and stimulate hormone release, the degree of muscarinic inhibition was increased, but the potency remained unchanged. Similar changes in the secretory rate of prolactin and growth hormone occurred in these and in cell perifusion experiments. These results suggest that the inhibition of hormone secretion from GH3 cells by muscarinic agonists is mediated by a decrease in intracellular cyclic AMP levels. 相似文献
999.
B. L. Ganzha 《Neurophysiology》1986,18(1):48-54
Summated electrical activity of the human amygdaloid nucleus was investigated in the neurosurgical clinic by chronically implanted electrodes. It was found that odoriferous stimulation of this structure produced bursts of rapid rhythm (20–30 cps, 30–50 µV). The quasisinusoidal waves of olfactory rhythm consist of sinusoidal components which are more pronounced within the 20–30-Hz frequency range. Spindling of 1–3 sec duration occurs at the end of inhalation and the beginning of exhalation in time with breathing. During monorhinal breathing this activity, whose amplitude depends on degree of olfactory stimulation, can only be recorded ipsilaterally. Room air also activates the amygdaloid nucleus, but less strongly than odoriferous substances: No characteristic odor-dependent differences were discovered in the frequency range of the olfactory rhythm within a 20–30-Hz band.Institute of Physiology, Kiev State University, Kiev. Translated from Neirofiziologiya, Vol. 18, No. 1, pp. 61–69, January–February, 1986. 相似文献
1000.