首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1277398篇
  免费   92774篇
  国内免费   1989篇
耳鼻咽喉   18195篇
儿科学   42282篇
妇产科学   37861篇
基础医学   187078篇
口腔科学   35395篇
临床医学   108210篇
内科学   251633篇
皮肤病学   26507篇
神经病学   99274篇
特种医学   50014篇
外国民族医学   366篇
外科学   197716篇
综合类   26527篇
现状与发展   1篇
一般理论   300篇
预防医学   92621篇
眼科学   29085篇
药学   97793篇
  1篇
中国医学   2496篇
肿瘤学   68806篇
  2018年   11815篇
  2015年   11621篇
  2014年   16013篇
  2013年   24371篇
  2012年   33575篇
  2011年   35976篇
  2010年   21225篇
  2009年   20029篇
  2008年   35017篇
  2007年   37994篇
  2006年   38530篇
  2005年   37830篇
  2004年   36415篇
  2003年   35406篇
  2002年   34944篇
  2001年   58114篇
  2000年   59613篇
  1999年   50701篇
  1998年   14242篇
  1997年   12816篇
  1996年   13081篇
  1995年   12351篇
  1994年   11761篇
  1993年   10867篇
  1992年   40995篇
  1991年   40376篇
  1990年   39906篇
  1989年   38725篇
  1988年   36126篇
  1987年   35371篇
  1986年   33742篇
  1985年   32153篇
  1984年   23945篇
  1983年   20833篇
  1982年   12384篇
  1981年   10940篇
  1980年   10210篇
  1979年   22647篇
  1978年   15889篇
  1977年   13736篇
  1976年   12978篇
  1975年   14205篇
  1974年   16689篇
  1973年   16082篇
  1972年   15324篇
  1971年   14237篇
  1970年   13220篇
  1969年   12735篇
  1968年   11983篇
  1967年   10479篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES) of the human motor cortex produce a silent period (SP) following motor evoked potentials (MEPs). The early part of the SP can be explained by decreased alpha motor neuron excitability, whereas the late part is presumably due to suprasegmental mechanisms. In order to determine the level of the suprasegmental contribution to the generation of SPs, we recorded excitatory and inhibitory responses to TMS, TES, and percutaneous electrical brainstem stimulation (PBS) in the voluntarily activated first dorsal interosseous muscle of the hand. Stimulus intensities were set so that PBS and TES induced MEPs with areas equal to or larger than those of MEPs obtained with TMS. This procedure revealed that SPs were 49% and 83% shorter with TES and PBS, respectively, than with TMS. As TMS is more effective than TES or PBS in activating cortical interneurons, these findings support the idea that a significant component of the SP arises from intracortical mechanisms.  相似文献   
102.
103.
Internal eye wall resection in the management of uveal melanoma   总被引:3,自引:0,他引:3  
Twenty patients with presumed uveal melanoma underwent internal eye wall resection. It was the primary procedure in 13 patients who had tumours within 2 disc diameters of the optic nerve head and was combined with external resection in the remainder. Malignant melanoma was confirmed histologically in 15 patients; the diagnosis was a benign tumour in the other 5. The length of follow-up ranged from 2 to 37 (mean 19) months. In all cases the retina was completely attached at the time of last examination. The visual acuity ranged from 20/40 to hand movements; nine patients had an acuity of 20/400 or better. At the time of writing no metastatic disease or local recurrence had developed in any of the 15 patients in whom malignant melanoma was diagnosed.  相似文献   
104.
We describe a mild form of drug-induced pemphigus in a woman with essential arterial hypertension treated with captopril. Complete recovery was observed three weeks after the therapy had been discontinued.  相似文献   
105.
106.
107.
Noninvasive localized proton magnetic resonance spectroscopy (MRS) was used for differential diagnosis of a focal brain lesion in a 2.5-year-old girl. The clinical signs were a mild head tilt and neck pain. Magnetic resonance imaging (MRI) revealed a lesion in the right hemisphere of the cerebellum, but its nature remained obscure. In this lesion quantitative determinations of cerebral metabolites by fully relaxed, short-echo-time proton MRS revealed markedly lowered N-acetylaspartate (NAA) and pronounced elevations of choline-containing compounds (Cho) and myo-inositol (Ins), whereas metabolite concentrations in cortical gray matter and white matter were within normal ranges. The metabolite pattern of the lesion indicated loss of vital neuroaxonal tissue (low NAA) and enhanced glial proliferation (high Cho and Ins), which, together with the MRI morphology, suggested a brain tumor. The diagnosis was established by neurosurgical exploration and total extirpation of the tumor. Histology confirmed an astrocytoma (WHO II). After 2 weeks' recovery the child was discharged with no neurological signs.  相似文献   
108.
109.
The role of caffeine or coffee in causing or promoting the incidence of serious disease is equivocal. Two design factors may account for the discrepancies in reported findings on the effects of coffee drinking: (a) imprecision of measurement and (b) confounding variables. A study of 2,714 white U.S. adults disclosed that, of 32 risk factors analyzed by linear and logistic regression, only sex and cigarette smoking were found to be important potential confounders of caffeine and coffee intake. Partial R2 values of the other 30 risk factors were relatively small and were inconsistent for each sex. It is unlikely that any of these factors could explain any of the reported associations between caffeine or coffee consumption and certain diseases. However, certain weak associations with caffeine or coffee intake should be included in the study design when they are known to be risk factors of a disease under investigation. These factors for men are dietary fat intake, vitamin C intake, and body mass index; and for women are vitamin use, alcohol intake, stress, and perceived health status.  相似文献   
110.
In der Behandlung von Frakturen spielt die Analgesie eine wesentliche Rolle. Es stellt sich daher die Frage, ob in der Klinik h?ufig eingesetzte Analgetika wie Tramadol oder Diclofenac negative Wirkungen auf die Knochenbruchheilung haben.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号