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   4067篇
  免费   481篇
  国内免费   11篇
耳鼻咽喉   15篇
儿科学   155篇
妇产科学   451篇
基础医学   377篇
口腔科学   98篇
临床医学   1029篇
内科学   647篇
皮肤病学   113篇
神经病学   331篇
特种医学   294篇
外科学   238篇
综合类   96篇
一般理论   2篇
预防医学   288篇
眼科学   30篇
药学   129篇
中国医学   4篇
肿瘤学   262篇
  2023年   50篇
  2021年   32篇
  2020年   49篇
  2019年   59篇
  2018年   103篇
  2017年   124篇
  2016年   119篇
  2015年   126篇
  2014年   149篇
  2013年   156篇
  2012年   145篇
  2011年   171篇
  2010年   147篇
  2009年   145篇
  2008年   147篇
  2007年   145篇
  2006年   133篇
  2005年   124篇
  2004年   96篇
  2003年   130篇
  2002年   90篇
  2001年   110篇
  2000年   103篇
  1999年   108篇
  1998年   128篇
  1997年   130篇
  1996年   127篇
  1995年   113篇
  1994年   85篇
  1993年   60篇
  1992年   61篇
  1991年   75篇
  1990年   61篇
  1989年   89篇
  1988年   92篇
  1987年   61篇
  1986年   69篇
  1985年   72篇
  1984年   46篇
  1983年   38篇
  1982年   40篇
  1981年   30篇
  1980年   32篇
  1979年   28篇
  1978年   34篇
  1977年   30篇
  1976年   38篇
  1975年   37篇
  1974年   26篇
  1973年   25篇
排序方式: 共有4559条查询结果,搜索用时 171 毫秒
21.
22.
Superior cervical ganglionectomy (SCGx) abolished the nocturnal rise in pineal type-II thyroxine 5'-deiodinase (5'-D) activity in both euthyroid and hypothyroid rats. Isoproterenol induced at least as great a rise in diurnal pineal 5'-D in SCGx as in intact rats. These data suggest that beta-adrenergic stimulation through the superior cervical ganglia is essential for the nocturnal rise in pineal 5'-D activity.  相似文献   
23.
24.
An Australian school of nursing's attempt to introduce an evaluation process required by management for clinical educators involved in undergraduate preregistration education is discussed Reliance on student feedback and clinical agencies' perceptions of the quality of teaching were seen as inadequate mechanisms for evaluation The evaluation process adopted incorporated observation of the educators together with self-reflection on their performance We conclude that post-briefings were poorly used and generally not reflective Educators relied heavily on their clinical skills and used a limited range of teaching strategies Whilst evaluation of clinical educators was time consuming and therefore costly, it is argued that it is essential to the integrity of the course The evaluation process has provided direction for support and development of clinical educators within the context of the curriculum  相似文献   
25.
Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated.  相似文献   
26.
27.
A national study was conducted between 1991 and 1994 to explore and describe the changing role of the nurse teacher following the introduction of Project 2000 pre-registration nursing courses. Multiple methods were used to collect data from a wide variety of respondents (nurse teachers, midwife teachers, clinical nurses, health service managers and higher education lecturers). This paper presents the findings relating to the impact of Project 2000 and the move into higher education on the continuing educational needs of nurse teachers. Views on college strategies for staff development, the changing nature of teachers'academic and professional development needs and the problems of the conflicting demands experienced are reported. The research highlights the need for clinical credibility to be clearly defined in relation to nurse teachers and for educational institutions to place more emphasis on teachers'clinical development if the rhetoric of policy is to become a reality.  相似文献   
28.
Massachusetts civil commitment criteria were compared in an emergency setting with a set of criteria developed by Dr. Alan Stone. Contrary to expectations, the Stone criteria proved to be more restrictive in a sample of 503 patients. Few patients would be newly committable under the Stone criteria; of the 35 patients committable under the Stone standard, 32 also met the current Massachusetts criteria for commitment. The clinical and policy implications of the adoption of the Stone criteria are discussed.  相似文献   
29.
Abstract: A healthy boy had the distinctive lesions of erythrokeratodermia variabilis (EKV) at birth. Twenty-eight patients described in the literature had EKV that presented in childhood. Nine of the 28 were said to have had a rash since birth, but none were distinctive of EKV. To our knowledge this is the first well-documented case describing a child born with the skin manifestations of EKV. We conclude that patients with EKV are infrequently born with a rash, and that only very rarely when the rash is present is it suggestive of the disorder.  相似文献   
30.
Previous studies on human cortical area 39 suggested that neuron:glial ratios differed between the sexes. These findings were the inspiration for the present investigation which dealt with neuronal and glial counts in area 39 in the male and female rat cerebral cortex. Transverse, celloidin or frozen sections, were cut from male and female brains (respectively) from 90-day-old Long-Evans rats. Neurons and glia were counted on enlarged photographs of stained sections, including area 39, with 35-mm Kodak Panatomic-X film using a Zeiss photomicroscope (X400). Five-by-three-inch prints were taped together in sequence to yield a 640X enlarged "montage" of area 39. Five cell types were differentiated with reference to a standard: neurons, astrocytes, oligodendrocytes, "dark astrocytes," and unidentified glia. The data were analyzed with a two-way analysis of variance (ANOVA: five cell types by two hemispheres). Student's t test and a paired t test were used when appropriate. The neuron:glial ratios in the male rats were consistently higher than those in the females in both hemispheres. The male right side had 12% (P less than 0.05) more neurons than the left; the female had 13% (P less than 0.05) more neurons on the left than the right. Similar, but not identical, asymmetrical patterns were seen with the glial cells.  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