全文获取类型
收费全文 | 3330篇 |
免费 | 283篇 |
专业分类
3613篇 |
出版年
2023年 | 31篇 |
2022年 | 71篇 |
2021年 | 102篇 |
2020年 | 75篇 |
2019年 | 71篇 |
2018年 | 93篇 |
2017年 | 67篇 |
2016年 | 125篇 |
2015年 | 211篇 |
2014年 | 222篇 |
2013年 | 291篇 |
2012年 | 326篇 |
2011年 | 276篇 |
2010年 | 205篇 |
2009年 | 173篇 |
2008年 | 179篇 |
2007年 | 174篇 |
2006年 | 153篇 |
2005年 | 111篇 |
2004年 | 109篇 |
2003年 | 90篇 |
2002年 | 65篇 |
2001年 | 33篇 |
2000年 | 35篇 |
1999年 | 24篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 9篇 |
1992年 | 28篇 |
1991年 | 12篇 |
1990年 | 16篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 11篇 |
1976年 | 6篇 |
1975年 | 10篇 |
1974年 | 6篇 |
1973年 | 5篇 |
排序方式: 共有3613条查询结果,搜索用时 0 毫秒
1.
C Julien C Barres P Kandza J Sassard 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1989,308(8):219-222
Intra-aortic blood pressure (BP) was measured in conscious rats after early chronic destruction of the peripheral sympathetic nervous system (SNS) with guanethidine. In sympathectomized rats, the mean level of BP was not different from that of control rats but its variability was markedly increased. These results indicate that functional integrity of the SNS is of primary importance for the short-term control of BP but is not essential for its long-term maintenance. 相似文献
2.
3.
Sequence complexity and diversity of polyadenylated RNA molecules transcribed in human myeloid cells
4.
5.
6.
7.
8.
9.
A study of the monomeric chromophore of the oligopeptides netropsin (1), distamycin III (2), and distamycin V (3) by polarization spectroscopy techniques and molecular orbital calculations is reported. Linear dichroism spectra of the monomeric model compounds 1-methyl-2(ethylcarbamoyl)-4-acetamido-pyrrole (4) and 1-methyl-2(ethylcarbamoyl)-pyrrole (5) dissolved and oriented in lyotropic and thermotropic liquid crystals provide, together with the magnetic CD spectra, experimental checks of the theoretical calculations. The polarization directions of the investigated transition obtained by these means in this study allow us to build up in the following paper the exciton states of (1)-(3) and these provide a stereochemical interpretation of the flow linear dichroism spectra of the complexes of DNA with (2) and (3). 相似文献
10.
Neurotransmitter, opiodergic system, steroid-hormone interaction and involvement in the replacement therapy of sexual disorders 总被引:1,自引:0,他引:1
G Frajese R Lazzari A Magnani C Moretti V Sforza D Nerozzi 《The Journal of steroid biochemistry and molecular biology》1990,37(3):411-419
Dopamine (DA) and serotonin (5-HT) are the neurotransmitters most directly involved in sexual activity. DA plays a stimulatory role while 5-HT has an inhibitory effect. The two monoaminergic systems modulate the secretion of many hormones (GnRH, LH, testosterone, prolactin and endorphins) involved in sexual functional capacity. Furthermore, hormones influence synthesis and storage of brain neurotransmitters. Impotence can often be associated to clinical depression and altered neurotransmitter function. Moreover, stress represents an unbalance between various neurotransmitter systems and can induce impotence especially when disorders of the endorphinic system are present. Replacement therapy is based upon the understanding of these basic concepts. Impotence due to an underlying depressive illness must be treated with dopaminergic antidepressant drugs; while in stressful conditions a good response to the naloxone test is the preliminary criterion to subsequent naltrexone treatment. When a hormonal deficiency has been proved, the hormone replacement therapy is of course highly effective (gonadotropins in hypogonadotropic syndromes, testosterone in aging, etc.). Finally, idiopathic impotence could be treated by DA agonist and/or 5-HT antagonist drugs either alone or better yet in association with psychotherapy. 相似文献