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   17984篇
  免费   6314篇
  国内免费   75篇
耳鼻咽喉   343篇
儿科学   409篇
妇产科学   420篇
基础医学   494篇
口腔科学   1611篇
临床医学   6177篇
内科学   4279篇
皮肤病学   560篇
神经病学   2453篇
特种医学   549篇
外科学   2451篇
综合类   27篇
现状与发展   2篇
一般理论   1篇
预防医学   2542篇
眼科学   348篇
药学   322篇
中国医学   5篇
肿瘤学   1380篇
  2024年   143篇
  2023年   1309篇
  2022年   316篇
  2021年   721篇
  2020年   1160篇
  2019年   513篇
  2018年   1539篇
  2017年   1682篇
  2016年   1663篇
  2015年   1711篇
  2014年   1954篇
  2013年   1921篇
  2012年   786篇
  2011年   811篇
  2010年   1149篇
  2009年   1501篇
  2008年   602篇
  2007年   410篇
  2006年   516篇
  2005年   321篇
  2004年   244篇
  2003年   224篇
  2002年   180篇
  2001年   289篇
  2000年   151篇
  1999年   248篇
  1998年   285篇
  1997年   302篇
  1996年   300篇
  1995年   255篇
  1994年   167篇
  1993年   151篇
  1992年   113篇
  1991年   91篇
  1990年   80篇
  1989年   94篇
  1988年   72篇
  1987年   57篇
  1986年   47篇
  1985年   49篇
  1984年   36篇
  1983年   28篇
  1982年   26篇
  1981年   19篇
  1980年   21篇
  1979年   16篇
  1978年   15篇
  1977年   11篇
  1972年   11篇
  1971年   13篇
排序方式: 共有10000条查询结果,搜索用时 562 毫秒
81.
82.
83.
Estrogen deficiency is associated with impaired cutaneous wound healing. Remodeling of the extracellular matrix in wound healing involves the action of matrix metalloproteinases on basement membrane zone components, especially laminin-5. We studied the effects of estrogen and a potent matrix metalloproteinase inhibitor, chemically modified non-antimicrobial tetracycline, CMT-8, on wound healing in ovariectomized rats. At the tissue level, laminin-5 gamma2-chain expression was decreased and the migration-inductive 80 kDa form of laminin-5 gamma2-chain was absent in ovariectomized rats when compared with sham and CMT-8- or estrogen-treated ovariectomized animals as detected by Western blotting. The highest levels of gelatinolytic activity (matrix metalloproteinase-2 and -9) were found in sham animals. Levels were reduced in ovariectomized rats and were lowest after treating ovariectomized rats with CMT-8 or estrogen as analyzed by functional activity assay and zymography. The total amount of membrane type 1-matrix metalloproteinase was unchanged in all groups. We conclude that CMT-8 and estrogen can promote wound healing in ovariectomized rats, not only by normalizing wound bed total collagen content and structure, but also by recovering the expression and processing of key molecules in wound healing, i.e., laminin-5 gamma2-chain. This study shows, for the first time, the role of estrogen and CMT-8 in laminin-5 gamma2-chain modulation in vivo.  相似文献   
84.
Youth suicide constitutes a considerable public health problem in many European countries. Suicide mortality in adolescents and young adults has increased during the 1980s and 1990s in several European countries and predominantly in young males. This paper summarises the international discussion on potential reasons for these trends, including changes in ascertainment practices, in the prevalence of psychopathology (mainly depression and substance abuse), in psychosocial and socio-economic conditions and in the methods chosen for suicidal behaviour. Potential reasons for the gender differences in trends are scrutinised.  相似文献   
85.
86.
The literature on group coping skills training is reviewed and a model involving the use of a wide range of coping strategies with patients heterogeneous in terms of presenting problem is advocated. This study evaluates the effect of such an approach with a chronic inpatient and day-hospital patient population (n = 36) presenting with problems of anxiety and depression. Results suggest that the use of such groups can facilitate the transition from hospital to community. Further they are associated with symptomatic improvement that is of clinical significance in up to 50% of cases, which is largely maintained at 1 year follow-up and which is associated with a positive change in social functioning. In the light of this experience suggestions are made regarding the screening of patients and ways of enhancing group cohesion.  相似文献   
87.
Patient teaching or patient counselling?   总被引:1,自引:0,他引:1  
Careless or confused use of terms such as information giving, teaching and counselling may lead to inadequate understanding and practice. In view of the progress made in this area, designed to help patients cope with illness and treatment, this paper aims to clarify and identify similarities and differences between these activities and discuss their relevance for those in most need of these types of care. Having recognised the complexity and persistence of such needs, patients, their relatives and nurses should perhaps decide their respective roles and work towards improving the quality of and opportunities for such interventions.  相似文献   
88.
The biliary excretion of radioactivity after intravenous [3H]25-hydroxyvitamin D3 was studied in nine patients with T-tube bile drainage. The mean +/- SD 24-hr radioactivity excretion in T-tube bile expressed as a percentage of the administered dose was 6.7 +/- 2.9%; after correction for incomplete bile collection, the value obtained was 16.0 +/- 11.1%. Chloroform solubility of biliary radioactivity increased from 27.4 +/- 8.9% to 72.9 +/- 10.1% following incubation with beta-glucuronidase. High-performance liquid chromatographic analysis of chloroform extracts of bile revealed that most of the eluted radioactivity was more polar than [3H]25-hydroxyvitamin D3. No free [3H]25-hydroxyvitamin D3 was demonstrated. Thus in man, most of the biliary radioactivity excreted following [3H]25-hydroxyvitamin D3 is in the form of water-soluble compounds, mainly glucuronides. However, our results suggest that glucuronides of metabolites other than 25-OHD3 are predominantly formed.  相似文献   
89.
The rubric complementary medicine covers a variety of approaches that may seem alike only in their being outside conventional care and training. We have asked experienced practitioners to present their own pieces of this jigsaw, realising that these clinical fragments, when seen together, create excitement but also confusion. Of course, this forum is not intended to be a comprehensive review of relevant complementary treatments, and often the individual apporaches to clinical problems will appear totally unrelated, while their apparent effectiveness stretches the biomedical model and conventional research methodology beyond their capacity. With this in mind, we intend that forthcoming articles and reviews will expand on the therapies themselves, and discuss the evidence supporting them.  相似文献   
90.
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