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   1994830篇
  免费   151034篇
  国内免费   4295篇
耳鼻咽喉   29912篇
儿科学   59158篇
妇产科学   57705篇
基础医学   281728篇
口腔科学   60669篇
临床医学   171708篇
内科学   385286篇
皮肤病学   43153篇
神经病学   161060篇
特种医学   79944篇
外国民族医学   590篇
外科学   311565篇
综合类   50785篇
现状与发展   7篇
一般理论   673篇
预防医学   146012篇
眼科学   47873篇
药学   150130篇
  4篇
中国医学   4116篇
肿瘤学   108081篇
  2018年   17401篇
  2015年   17848篇
  2014年   25273篇
  2013年   38712篇
  2012年   51036篇
  2011年   53784篇
  2010年   31832篇
  2009年   30564篇
  2008年   51542篇
  2007年   56176篇
  2006年   56546篇
  2005年   55061篇
  2004年   53934篇
  2003年   52086篇
  2002年   50806篇
  2001年   88702篇
  2000年   91121篇
  1999年   77372篇
  1998年   21763篇
  1997年   19955篇
  1996年   19259篇
  1995年   18251篇
  1994年   17315篇
  1992年   62619篇
  1991年   60677篇
  1990年   59688篇
  1989年   58052篇
  1988年   54321篇
  1987年   53535篇
  1986年   51200篇
  1985年   48974篇
  1984年   37305篇
  1983年   31741篇
  1982年   19509篇
  1981年   17960篇
  1980年   16715篇
  1979年   36743篇
  1978年   26347篇
  1977年   22675篇
  1976年   20598篇
  1975年   22980篇
  1974年   27861篇
  1973年   26947篇
  1972年   25747篇
  1971年   24048篇
  1970年   22884篇
  1969年   22008篇
  1968年   20288篇
  1967年   18487篇
  1966年   17271篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
31.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
32.
33.
34.
35.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
36.
37.
38.
39.
Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.  相似文献   
40.
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