全文获取类型
收费全文 | 1723976篇 |
免费 | 126611篇 |
国内免费 | 6005篇 |
专业分类
耳鼻咽喉 | 22049篇 |
儿科学 | 55962篇 |
妇产科学 | 46481篇 |
基础医学 | 244610篇 |
口腔科学 | 49270篇 |
临床医学 | 155214篇 |
内科学 | 337735篇 |
皮肤病学 | 38986篇 |
神经病学 | 132644篇 |
特种医学 | 64940篇 |
外国民族医学 | 258篇 |
外科学 | 259819篇 |
综合类 | 43964篇 |
现状与发展 | 11篇 |
一般理论 | 536篇 |
预防医学 | 126347篇 |
眼科学 | 41054篇 |
药学 | 126779篇 |
26篇 | |
中国医学 | 6285篇 |
肿瘤学 | 103622篇 |
出版年
2021年 | 14318篇 |
2019年 | 14560篇 |
2018年 | 21017篇 |
2017年 | 16279篇 |
2016年 | 17585篇 |
2015年 | 20301篇 |
2014年 | 27959篇 |
2013年 | 39519篇 |
2012年 | 55009篇 |
2011年 | 57825篇 |
2010年 | 34269篇 |
2009年 | 31899篇 |
2008年 | 53081篇 |
2007年 | 56316篇 |
2006年 | 56668篇 |
2005年 | 53961篇 |
2004年 | 51724篇 |
2003年 | 49087篇 |
2002年 | 47172篇 |
2001年 | 92386篇 |
2000年 | 94133篇 |
1999年 | 77503篇 |
1998年 | 20102篇 |
1997年 | 17616篇 |
1996年 | 17645篇 |
1995年 | 17020篇 |
1994年 | 15520篇 |
1993年 | 14241篇 |
1992年 | 57561篇 |
1991年 | 55428篇 |
1990年 | 53091篇 |
1989年 | 50861篇 |
1988年 | 46240篇 |
1987年 | 45015篇 |
1986年 | 42293篇 |
1985年 | 40042篇 |
1984年 | 29367篇 |
1983年 | 24934篇 |
1982年 | 13901篇 |
1979年 | 25544篇 |
1978年 | 17580篇 |
1977年 | 14911篇 |
1976年 | 13880篇 |
1975年 | 14567篇 |
1974年 | 17635篇 |
1973年 | 16949篇 |
1972年 | 15675篇 |
1971年 | 14456篇 |
1970年 | 13435篇 |
1969年 | 12518篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
971.
972.
Soluflazine, a specific adenosine transport inhibitor, was intracerebroventricularly administered to rats in a dose range of 10, 25, and 50 nmoles. At a dose of 50 nmoles, soluflazine decreased waking and increased sleep during the first hour of EEG recording. Our previous work has shown that chronic intracerebroventricular administration of soluflazine to rats decreased radioligand binding to adenosine A1 and A2 receptors in specific brain regions. The present data show that administration of an adenosine transport inhibitor to rats produces a transient hypnotic effect presumably through increases in synaptic adenosine levels. 相似文献
973.
Despite current intensive research, the pathophysiology of tardive dyskinesia (TD), a serious neurological side effect of neuroleptic treatment, is poorly understood. Prompted by the observation of an increased incidence and severity of abnormal perioral movements in neuroleptic-treated pinealectomized, as compared to intact rats, we suggested that the pineal gland exerts a protective effect which mitigates against the development of TD and, by inference, that reduced melatonin secretion may be related to the pathophysiology of TD. To investigate this proposition further, we studied the association of TD with pineal calcification (PC) on CT scan in chronic schizophrenic patients. Our findings revealed a significant association between TD and PC and suggest, furthermore, that PC may be a neuroradiological marker of TD. Since PC may reflect diminished secretory activity of the gland, these findings support the hypothesis that the pathophysiology of TD is linked to disturbances of melatonin secretion. The clinical and therapeutic implications of these novel findings are discussed. In the following communication, in which we introduce the hypothesis that disturbances of 5-HT and melatonin secretion are related to the pathophysiology of TD. Subsequently, we present a series of studies which relate to the association of TD with PC. We conclude by presenting the hypothesis that disturbances in melatonin secretion may also be relevant to the pathophysiology of Tourette's syndrome. 相似文献
974.
975.
The purpose of this study was to evaluate three subcutaneous injection sites for low-dose heparin therapy (5,000 units). One hundred and one subjects were randomly placed in one of three groups. Group A received injections in the abdomen, Group B, in the thigh, and Group C in the arm. Each subject received three injections at the one site. Activated partial thromboplastin time (APTT) was measured prior to initiation of heparin and again four hours after the first injection. Bruising was measured at 48, 60, and 72 hours postinjection. There were no statistically significant differences among groups for either changes in APTT or bruising at 60 and 72 hours postinjection. Thus the clinical practice of utilizing the abdomen as the only or preferred site for subcutaneous heparin injections was not supported. 相似文献
976.
977.
Computed tomography (CT) was performed in 14 cases of tuberculous meningitis (TBM), 12 of which were examined during the acute phase of the disease. CT findings in these cases included internal hydrocephalus (6/12), internal combined with external hydrocephalus (2/12), focal lesions consistent with localized encephalitis (3/12), diffuse brain edema (1/12), and middle cerebral artery infarction (1/12). In comparison to 32 cases of nonspecific bacterial meningitis, internal hydrocephalus was found significantly more often in TBM than in nonspecific meningitis (p less than 0.01) making CT an additional tool for the differentiation of these conditions in doubtful cases. In addition, CT features of 2 cases of cerebral tuberculoma are presented. 相似文献
978.
Background
The telomeric region of mouse chromosome 12 has previously shown frequent allelic loss in murine lymphoma. The Bcl11b gene has been identified and suggested as a candidate tumor suppressor gene within this region. In this study, we aimed to elucidate whether Bcl11b is mutated in lymphomas with allelic loss, and whether the mutations we detected conferred any effect on cell proliferation and apoptosis. 相似文献979.
980.