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   250341篇
  免费   16873篇
  国内免费   1079篇
耳鼻咽喉   2668篇
儿科学   6369篇
妇产科学   5031篇
基础医学   32933篇
口腔科学   5504篇
临床医学   24291篇
内科学   53964篇
皮肤病学   3916篇
神经病学   23270篇
特种医学   9396篇
外国民族医学   9篇
外科学   38560篇
综合类   3300篇
现状与发展   3篇
一般理论   214篇
预防医学   18824篇
眼科学   5794篇
药学   16730篇
  2篇
中国医学   382篇
肿瘤学   17133篇
  2023年   1206篇
  2022年   1924篇
  2021年   4405篇
  2020年   2793篇
  2019年   4351篇
  2018年   5269篇
  2017年   4013篇
  2016年   4548篇
  2015年   5257篇
  2014年   7650篇
  2013年   10978篇
  2012年   16441篇
  2011年   17321篇
  2010年   9825篇
  2009年   9246篇
  2008年   16112篇
  2007年   17452篇
  2006年   16616篇
  2005年   16980篇
  2004年   16241篇
  2003年   15386篇
  2002年   14761篇
  2001年   2301篇
  2000年   1716篇
  1999年   2378篇
  1998年   3356篇
  1997年   2757篇
  1996年   2358篇
  1995年   2238篇
  1994年   1976篇
  1993年   1834篇
  1992年   1372篇
  1991年   1348篇
  1990年   1093篇
  1989年   1095篇
  1988年   1019篇
  1987年   1069篇
  1986年   992篇
  1985年   1065篇
  1984年   1365篇
  1983年   1333篇
  1982年   1743篇
  1981年   1609篇
  1980年   1459篇
  1979年   833篇
  1978年   912篇
  1977年   979篇
  1976年   830篇
  1975年   730篇
  1974年   604篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The Stiff Elbow     
Elbow motion is essential for upper extremity function to position the hand in space. Unfortunately, the elbow joint is prone to stiffness following a multitude of traumatic and atraumatic etiologies. Elbow stiffness can be diagnosed with a complete history and physical exam, supplemented with appropriate imaging studies. The stiff elbow is challenging to treat, and thus, its prevention is of paramount importance. When this approach fails, non-operative followed by operative treatment modalities should be pursued. Upon initial presentation in those who have minimal contractures of 6-month duration or less, static and dynamic splinting, serial casting, continuous passive motion, occupational/physical therapy, and manipulation are non-operative treatment modalities that may be attempted. A stiff elbow that is refractory to non-operative management can be treated surgically, either arthroscopically or open, to eliminate soft tissue or bony blocks to motion. In the future, efforts to prevent and treat elbow stiffness may target the basic science mechanisms involved. Our purpose was to review the etiologies, classification, evaluation, prevention, operative, and non-operative treatment of the stiff elbow.  相似文献   
82.
83.
84.
85.
The purpose of the study was to determine the incidence, risk factors, treatment, and influence on survival of patients with de novo esophageal cancer after liver transplantation (LT). From 1988 to 2006, 1,926 patients underwent LT in our institution. A total of 9 patients (0.5%) developed a de novo esophageal cancer and 1 patient a cancer of the cardia (0.05%). A retrospective analysis was performed to reveal underlying diseases, timeframes between LT and appearance of cancer, predisposing factors, cancer therapy, complications, immunosuppressive regimens, and survival. Of our 10 patients, 7 (70%) suffered from esophageal squamous cell carcinoma (SCC) and 3 patients (30%) developed an adenocarcinoma, including the patient with cancer of the cardia. A total of 9 patients were transplanted due to alcoholic cirrhosis; 1 patient suffered from hepatocellular carcinoma in nonA-nonB hepatitis-related cirrhosis. Median time to tumor diagnosis was 51 months after transplantation. A total of 5 patients were treated conservatively with combined radiochemotherapy and 5 underwent surgical resection. Patients with radiochemotherapy showed a mean survival of 14.8 months vs. 24.8 months for the patients of the surgery group. No major postoperative complication has been observed. A total of 2 patients of the surgery group are still alive after a follow-up of 15 and 89 months. In conclusion, de novo esophageal and cancer of the cardia after LT is a rare event. In spite of immunosuppression, no increased complication rate has been observed. Patients may have a survival benefit from surgical resection.  相似文献   
86.
Teeth with white spot lesions (WSL) might be more prone to enamel loss during bracket debonding. This in vitro study compared enamel loss from teeth with (n = 14) and without (n = 14) WSL after polishing with low-speed finishing burs or disks (Sof-Lex, 3M ESPE, St Paul, Minn). Debonded surfaces were analyzed with a contact stylus profilometer, and digitized data were compared with baseline readings by using AnSur NT software (Regents, University of Minnesota, Minneapolis, Minn). Specimen surfaces were also examined with a scanning electron microscope. Two-way analysis of variance was performed to analyze the data. In teeth without WSL, the volume losses were 0.16 mm(3) for the bur group and 0.10 mm(3) for the disk group; the mean maximum depths were 47.7 microm for the bur group and 54.3 microm for the disk group. In teeth with WSL, the volume losses were 0.06 and 0.17 mm(3), and the mean maximum depths were 35.1 and 48.7 microm for the bur and disk groups, respectively. There were no significant differences in enamel loss between the 2 groups of teeth without WSL (P =.12). However, in teeth with WSL, the burs removed less enamel than the disks (P = 0.006). Scanning electron microscope examination showed that any damage on the enamel surface was usually located in the cervical third of the teeth. On most specimens, even though tooth surfaces appeared resin-free to the naked eye, there were remnants of it. The differences between groups were so small that they might be clinically insignificant.  相似文献   
87.
88.
89.
Twelve patients had limited arthrodesis between the scaphoid and the lunate for chronic static scapholunate dissociation using internal plate osteosynthesis. The median time between the injury and surgery was 50 months (range 9-180). They were followed up for a year postoperatively. Preoperative symptoms were pain, functional impairment, and restricted movement. During operation the scapholunate interosseous ligament was completely torn and the scaphoid malrotated in all patients. The range of motion was measured preoperatively and postoperatively, and the unaffected side used for control. For all patients except one postoperative extension, flexion, and radial deviation had considerably decreased. However, supination increased in seven of 12 patients postoperatively and so did pronation in seven of 12 patients. One patient (case 12) had an improved range of motion postoperatively in all directions. The mean grip strength was 76% of the unaffected side preoperatively, and has increased to 85% postoperatively. We found that bone healing was rare and most arthrodeses healed by a fibrous union. We found no correlation with preoperative arthrosis and clinical outcome. One patient had retired from work before operation because of back pain and one because of age. Two patients had taken early retirement because of wrist pain, and one patient was still on sick-leave at the follow-up a year postoperatively. Five patients returned to full-time work and two patients to part-time work. Four patients were on long-term sick-leave preoperatively and three of them returned to their previous occupations. Analysis of the patients' subjective outcome (including pain and functional scores) showed overall satisfaction, and objective data show that scapholunate arthrodesis for chronic static scapholunate dissociation provides substantial improvement over the preoperative condition.  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