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   2001804篇
  免费   151659篇
  国内免费   4298篇
耳鼻咽喉   30148篇
儿科学   59479篇
妇产科学   57910篇
基础医学   282637篇
口腔科学   60885篇
临床医学   172368篇
内科学   386535篇
皮肤病学   43283篇
神经病学   161674篇
特种医学   80263篇
外国民族医学   590篇
外科学   312399篇
综合类   50910篇
现状与发展   7篇
一般理论   693篇
预防医学   146698篇
眼科学   48110篇
药学   150468篇
  4篇
中国医学   4123篇
肿瘤学   108577篇
  2018年   17522篇
  2015年   17925篇
  2014年   25411篇
  2013年   38920篇
  2012年   51336篇
  2011年   54085篇
  2010年   31977篇
  2009年   30743篇
  2008年   51797篇
  2007年   56502篇
  2006年   56875篇
  2005年   55342篇
  2004年   54180篇
  2003年   52329篇
  2002年   51091篇
  2001年   88926篇
  2000年   91322篇
  1999年   77564篇
  1998年   21849篇
  1997年   20024篇
  1996年   19325篇
  1995年   18318篇
  1994年   17388篇
  1992年   62799篇
  1991年   60848篇
  1990年   59889篇
  1989年   58219篇
  1988年   54495篇
  1987年   53710篇
  1986年   51368篇
  1985年   49119篇
  1984年   37402篇
  1983年   31838篇
  1982年   19578篇
  1981年   18021篇
  1980年   16761篇
  1979年   36847篇
  1978年   26449篇
  1977年   22736篇
  1976年   20658篇
  1975年   23025篇
  1974年   27924篇
  1973年   27013篇
  1972年   25807篇
  1971年   24096篇
  1970年   22920篇
  1969年   22049篇
  1968年   20315篇
  1967年   18530篇
  1966年   17302篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.

Background and objectives

A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.

Case report

A 41 year‐old woman suffered a car accident. At the emergency department, no abnormalities were found in ECG or chest X‐ray. Abdominal ultrasound revealed the presence of abdominal free liquid and the patient was submitted to urgent exploratory laparotomy. Nevertheless, she persisted suffering arterial hypotension and metabolic acidosis. Looking for the reason of her hemodynamic instability, intraoperative transthoracic echocardiography was performed, finding out the presence of pericardial effusion. Once the cardiac surgeon extracted pericardial clots, patient's situation improved clinically and analytically.

Conclusion

Every anesthesiologist should be able to use the intraoperative echocardiography as an effective tool in order to establish the appropriate measures to promote the survival of patients suffering severe trauma.  相似文献   
33.

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   
34.
35.
36.
37.
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   
38.
39.
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