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   16543篇
  免费   1043篇
  国内免费   79篇
耳鼻咽喉   132篇
儿科学   425篇
妇产科学   418篇
基础医学   2622篇
口腔科学   662篇
临床医学   1377篇
内科学   3669篇
皮肤病学   341篇
神经病学   1958篇
特种医学   450篇
外科学   1458篇
综合类   41篇
一般理论   5篇
预防医学   1014篇
眼科学   274篇
药学   1353篇
中国医学   57篇
肿瘤学   1409篇
  2024年   18篇
  2023年   170篇
  2022年   393篇
  2021年   594篇
  2020年   361篇
  2019年   477篇
  2018年   575篇
  2017年   452篇
  2016年   523篇
  2015年   649篇
  2014年   741篇
  2013年   937篇
  2012年   1472篇
  2011年   1566篇
  2010年   777篇
  2009年   741篇
  2008年   1167篇
  2007年   1087篇
  2006年   1015篇
  2005年   925篇
  2004年   829篇
  2003年   753篇
  2002年   641篇
  2001年   75篇
  2000年   55篇
  1999年   69篇
  1998年   105篇
  1997年   94篇
  1996年   60篇
  1995年   57篇
  1994年   42篇
  1993年   30篇
  1992年   19篇
  1991年   17篇
  1990年   12篇
  1989年   23篇
  1988年   15篇
  1987年   22篇
  1986年   14篇
  1985年   14篇
  1984年   11篇
  1983年   15篇
  1982年   13篇
  1981年   12篇
  1980年   5篇
  1979年   5篇
  1978年   4篇
  1975年   3篇
  1973年   6篇
  1961年   1篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.

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   
2.
3.
4.
5.
6.
7.
8.
9.

Background

The efficacy of dexamethasone in extending the duration of local anaesthetic block is uncertain. In a randomised controlled triple blind crossover study in volunteers, we tested the hypothesis that neither i.v. nor perineurally administered dexamethasone prolongs the sensory block achieved with ropivacaine.

Methods

Ultrasound-guided ulnar nerve blocks (ropivacaine 0.75% wt/vol, 3 ml, with saline 1 ml with or without dexamethasone 4 mg) were performed on three occasions in 24 male volunteers along with an i.v. injection of saline 1 ml with or without dexamethasone 4 mg. The combinations of saline and dexamethasone were as follows: control group, perineural and i.v. saline; perineural group, perineural dexamethasone and i.v. saline; i.v. group, perineural saline and i.v. dexamethasone. Sensory block was measured using a VAS in response to pinprick testing. The duration of sensory block was the primary outcome and time to onset of sensory block the secondary outcome.

Results

All 24 subjects completed the trial. The median [inter-quartile range (IQR)] duration of sensory block was 6.87 (5.85–7.62) h in the control group, 7.37 (5.78–7.93) h in the perineural group and 7.37 (6.10–7.97) h in the i.v. group (P=0.61). There was also no significant difference in block onset time between the three groups.

Conclusion

Dexamethasone 4 mg has no clinically relevant effect on the duration of sensory block provided by ropivacaine applied to the ulnar nerve.

Clinical trial registration

DRKS, 00014604; EudraCT, 2018-001221-98.  相似文献   
10.
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