全文获取类型
收费全文 | 1278534篇 |
免费 | 98208篇 |
国内免费 | 1999篇 |
专业分类
耳鼻咽喉 | 18441篇 |
儿科学 | 44356篇 |
妇产科学 | 35008篇 |
基础医学 | 182177篇 |
口腔科学 | 33590篇 |
临床医学 | 111263篇 |
内科学 | 258331篇 |
皮肤病学 | 28023篇 |
神经病学 | 100371篇 |
特种医学 | 51217篇 |
外国民族医学 | 660篇 |
外科学 | 196398篇 |
综合类 | 27052篇 |
现状与发展 | 1篇 |
一般理论 | 377篇 |
预防医学 | 95718篇 |
眼科学 | 27919篇 |
药学 | 94769篇 |
2篇 | |
中国医学 | 2424篇 |
肿瘤学 | 70644篇 |
出版年
2018年 | 13132篇 |
2017年 | 9963篇 |
2016年 | 10897篇 |
2015年 | 12369篇 |
2014年 | 17162篇 |
2013年 | 26208篇 |
2012年 | 36016篇 |
2011年 | 38050篇 |
2010年 | 22798篇 |
2009年 | 21807篇 |
2008年 | 36634篇 |
2007年 | 39243篇 |
2006年 | 39499篇 |
2005年 | 38438篇 |
2004年 | 37589篇 |
2003年 | 36443篇 |
2002年 | 35793篇 |
2001年 | 63987篇 |
2000年 | 66494篇 |
1999年 | 56407篇 |
1998年 | 15128篇 |
1997年 | 13753篇 |
1996年 | 14195篇 |
1995年 | 13452篇 |
1994年 | 12765篇 |
1993年 | 11790篇 |
1992年 | 44554篇 |
1991年 | 43464篇 |
1990年 | 42216篇 |
1989年 | 40111篇 |
1988年 | 36894篇 |
1987年 | 36234篇 |
1986年 | 33618篇 |
1985年 | 32278篇 |
1984年 | 24136篇 |
1983年 | 20268篇 |
1982年 | 11723篇 |
1981年 | 10691篇 |
1980年 | 9515篇 |
1979年 | 21341篇 |
1978年 | 14821篇 |
1977年 | 12532篇 |
1976年 | 11693篇 |
1975年 | 12623篇 |
1974年 | 14661篇 |
1973年 | 14117篇 |
1972年 | 12944篇 |
1971年 | 11729篇 |
1970年 | 11050篇 |
1969年 | 10024篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
We have examined some of the binding characteristics and the autoradiographic distribution of binding sites for Na125I (I-Na) in airway tissue from the guinea-pig, monkey, pig, rat, mouse and from man. Basal I-Na (100 pM) binding levels were extremely low. However, in the presence of ascorbic acid (10 microM) or dithiothreitol (10 microM), I-Na binding was markedly increased in guinea-pig trachea, with lesser increases detected in monkey and rat trachea and in monkey and human bronchus. In guinea-pig trachea, ascorbic acid-induced I-Na binding was not saturable within the concentration range 100-620 pM and could not be reduced by washout. Autoradiography revealed that in central airways, I-Na binding was localized at or near the interface of the airway epithelium and submucosa in small clusters, apparently involving one or two cells per focus. The physiological significance of these binding sites is yet to be established, although they may be involved in intracellular iodine storage. 相似文献
942.
943.
944.
Initially, there is a high incidence of CNS-depressant side-effects when the aromatase inhibitor, aminoglutethimide, is used in the treatment of patients with advanced breast cancer. Tolerance to these effects develops with continued dosing. This study examines the development of tolerance to various indices of CNS depression with the drug in mice. Single doses of aminoglutethimide induced a dose-dependent depression of spontaneous locomotor activity, rotarod performance, righting reflex and body temperature and a dose-related antileptazol activity. On repeated dosing with the drug, tolerance to these various activities occurred. The tolerance was found to be dose-dependent in the rotarod and righting reflex tests and time-dependent in the locomotor and body temperature tests. Although the results do not allow a determination of whether this clearly demonstrated phenomenon in the mouse is primarily functional or dispositional, the slow onset (14 days) for complete tolerance may be indicative of a functional mechanism. 相似文献
945.
D H Russell N E Zorn A R Buckley P D Crowe M D Sauro E M Hadden R V Farese H E Laird 《European journal of pharmacology》1990,188(2-3):139-152
Prolactin (PRL) and other trophic factors rapidly activate a nuclear pool(s) of protein kinase C (nPKC) in purified splenocyte nuclei. The PRL also enhanced [2-3H]glycerol incorporation into nuclear mono- and triacylglycerol. An assay was devised which not only probed the ability of the hormone to activate protein kinase C (PKC) but also demonstrated the presence of nuclear substrates. Using this methodology, a biphasic concentration-response curve to PRL was observed. Heterologous species of PRL and various growth factors also activated nPKC. The PRL-induced nPKC stimulation was antagonized by various immunomodulators, G protein-coupling inhibitors, PKC inhibitors, a calmodulin inhibitor, and a peripheral benzodiazepine agonist and antagonist. A monoclonal antibody to PKC, anti-rat PRL antiserum and a monoclonal anti-rat PRL receptor antibody antagonized PRL-induced PKC-dependent nuclear phosphorylation, further implicating nPKC and a PRL receptor-mediated activation process. Nuclear PKC may be a major target for trophic regulation in response to both positive and negative growth signals. 相似文献
946.
947.
948.
A case of a giant aneurysm arising from the anterior cerebral artery and producing a left homonymous hemianopsia is presented. The aneurysm caused lateral compression of the posterior part of the optic chiasm. After preoperative dynamic assessment of the circle of Willis by angiography and by electroencephalographic recording during carotid artery compression, the aneurysm was trapped with microclips on the anterior cerebral artery proximal and distal to it. Visual field examination 6 months postoperatively showed complete visual field recovery. This is the first case of homonymous hemianopsia caused by an angiographically proven giant aneurysm of the ACA. 相似文献
949.
The qualities of daughter versus same-sex friend relationships were described by 151 married and widowed elderly women. The relation of these qualities to life satisfaction was assessed. Relationship qualities predicted life satisfaction in widowed women but not in married women. Significant predictors of life satisfaction for widows included the emotional support of daughters, the instrumental support of friends and friendship strength. In a comparison of the relationship qualities, both married and widowed respondents described daughters as providing more stimulation, ego support and utility than friends. Respondents also reported that relationships with daughters were stronger than those with friends. Married women described relationships with both daughters and friends as more stimulating than widowed women. The value of assessing qualitative indices compared to quantitative indices of later life relationships is discussed. 相似文献
950.