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   2411754篇
  免费   200558篇
  国内免费   4237篇
耳鼻咽喉   34899篇
儿科学   74090篇
妇产科学   63986篇
基础医学   340880篇
口腔科学   69164篇
临床医学   219540篇
内科学   475354篇
皮肤病学   48980篇
神经病学   205246篇
特种医学   97740篇
外国民族医学   886篇
外科学   365741篇
综合类   56357篇
现状与发展   1篇
一般理论   1005篇
预防医学   193273篇
眼科学   56337篇
药学   180401篇
  4篇
中国医学   4405篇
肿瘤学   128260篇
  2018年   25171篇
  2017年   19603篇
  2016年   21609篇
  2015年   24099篇
  2014年   34467篇
  2013年   52614篇
  2012年   71019篇
  2011年   74912篇
  2010年   43813篇
  2009年   41724篇
  2008年   71300篇
  2007年   75797篇
  2006年   76474篇
  2005年   74440篇
  2004年   71661篇
  2003年   69434篇
  2002年   68535篇
  2001年   113884篇
  2000年   118335篇
  1999年   99318篇
  1998年   28236篇
  1997年   25823篇
  1996年   25691篇
  1995年   24824篇
  1994年   23377篇
  1993年   21757篇
  1992年   79594篇
  1991年   76560篇
  1990年   73730篇
  1989年   71044篇
  1988年   65979篇
  1987年   64941篇
  1986年   61502篇
  1985年   58619篇
  1984年   44464篇
  1983年   37834篇
  1982年   23071篇
  1981年   20492篇
  1979年   41457篇
  1978年   29109篇
  1977年   24485篇
  1976年   22962篇
  1975年   24089篇
  1974年   29744篇
  1973年   28172篇
  1972年   26297篇
  1971年   24216篇
  1970年   22818篇
  1969年   21156篇
  1968年   19211篇
排序方式: 共有10000条查询结果,搜索用时 593 毫秒
41.

Introduction

Compression fractures of the cuboid bone in children and adolescents are rare. Fracture morphology, associated lesions, treatment options and long-term outcomes of this very rare injury are published in a few case reports. This study with review of the literature aims to support the understanding of fracture pattern and optimize pathways of decision making.

Material and Methods

A retrospective two-center study was performed in a patient cohort treated between 2001 and 2016. All patients aged less than 18 years who sustained a cuboid fracture were included. Age, gender, mechanism of injury, fracture morphology, amount of displacement, associated injuries, and therapy were analyzed. In the follow-up (FU), the AOFAS Midfoot Scale was investigated.

Results

Fractures of the cuboid bone were diagnosed in 7 boys and 9 girls. The mean age of the patients was 10 years (range: 2.2–16.1 years). According to the classification of Fenton we detected 11 (69%) type 2, 2 (12%) type 3 and 3 (19%) type 5b fractures. Other fracture types according to Fenton were not observed. All children under 10 years sustained a type 2 fracture. Open reduction and internal fixation was performed in 5 (31%) patients. Bone grafting was not necessary. FU was performed in 14/16 patients on average after 9 years (mean; range: 1.4–16.2 years). The mean AOFAS Midfoot Scale at FU for extra-articular type 2 fractures was 100 points, whereas in intra-articular fractures (Type 3) and fractures associated with mid-tarsal disruption (type 5b) worse results were found (95 and 66 points, accordingly).

Conclusion

This rare injury shows inhomogenous morphologies and offers different treatment approaches. Extra-articular Fenton type 2 lesions are the most common type of cuboid fracture in children (69%). A potential loss of length of the lateral column must be considered. In contrast to adults, type 1, 4, and 5a fractures were not found in our cohort of children and adolescents. Lower scores of the AOFAS Midfoot Scale were found with either intra-articular involvement or associated midfoot lesions.  相似文献   
42.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
43.
44.

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   
45.
46.
47.
48.
49.
50.
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