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   1866篇
  免费   106篇
  国内免费   39篇
耳鼻咽喉   65篇
儿科学   59篇
妇产科学   14篇
基础医学   177篇
口腔科学   48篇
临床医学   165篇
内科学   306篇
皮肤病学   37篇
神经病学   97篇
特种医学   122篇
外科学   467篇
综合类   56篇
预防医学   81篇
眼科学   50篇
药学   137篇
中国医学   5篇
肿瘤学   125篇
  2023年   12篇
  2022年   31篇
  2021年   63篇
  2020年   25篇
  2019年   50篇
  2018年   60篇
  2017年   43篇
  2016年   34篇
  2015年   38篇
  2014年   54篇
  2013年   58篇
  2012年   108篇
  2011年   131篇
  2010年   68篇
  2009年   67篇
  2008年   97篇
  2007年   103篇
  2006年   126篇
  2005年   111篇
  2004年   80篇
  2003年   68篇
  2002年   80篇
  2001年   44篇
  2000年   53篇
  1999年   37篇
  1998年   36篇
  1997年   29篇
  1996年   33篇
  1995年   20篇
  1994年   18篇
  1993年   28篇
  1992年   10篇
  1991年   16篇
  1990年   16篇
  1989年   21篇
  1988年   20篇
  1987年   13篇
  1986年   6篇
  1985年   10篇
  1984年   15篇
  1983年   12篇
  1982年   9篇
  1981年   13篇
  1980年   4篇
  1979年   7篇
  1978年   7篇
  1977年   4篇
  1976年   3篇
  1975年   3篇
  1957年   2篇
排序方式: 共有2011条查询结果,搜索用时 15 毫秒
11.
High-risk combinations of recipient and graft characteristics are poorly defined for liver retransplantation (reLT) in the current era. We aimed to develop a risk model for survival after reLT using data from the European Liver Transplantation Registry, followed by internal and external validation. From 2006 to 2016, 85 067 liver transplants were recorded, including 5581 reLTs (6.6%). The final model included seven predictors of graft survival: recipient age, model for end-stage liver disease score, indication for reLT, recipient hospitalization, time between primary liver transplantation and reLT, donor age, and cold ischemia time. By assigning points to each variable in proportion to their hazard ratio, a simplified risk score was created ranging 0–10. Low-risk (0–3), medium-risk (4–5), and high-risk (6–10) groups were identified with significantly different 5-year survival rates ranging 56.9% (95% CI 52.8–60.7%), 46.3% (95% CI 41.1–51.4%), and 32.1% (95% CI 23.5–41.0%), respectively (< 0.001). External validation showed that the expected survival rates were closely aligned with the observed mortality probabilities. The Retransplantation Risk Score identifies high-risk combinations of recipient- and graft-related factors prognostic for long-term graft survival after reLT. This tool may serve as a guidance for clinical decision-making on liver acceptance for reLT.  相似文献   
12.
Annals of Surgical Oncology - The liver-first approach in patients with synchronous colorectal liver metastases (CRLM) has gained wide consensus but its role is still to be clarified. We aimed to...  相似文献   
13.
14.
15.
A high-pressure liquid chromatographic method for determination of the bisdioxopiperazine derivative ADR-529 (ICRF-187), a compound proven effective in protection against anthracycline-induced cardiotoxicity, has been developed. The limit of quantitation was 5 ng/ml using a narrow-bore 5-m silica column and UV detection. The method was used for determination of pharmacokinetic profiles of ADR-529 after a 3-weekly i.v. administration of different doses of ADR-529 (600–1000 mg/m2) together with different doses of epirubicin (E, 60–100 mg/m2), fixed-dose cyclophosphamide (C, 600 mg/m2), fixed-dose 5-fluorouracil (F, 600 mg/m2), and daily administration of tamoxifen (T, 30 mg; CEF-T) in the treatment of patients with metastatic breast cancer. Pharmacokinetic parameters for epirubicin were also determined. The aim of the study was to determine (1) whether the pharmacokinetics of ADR-529 as part of a combination with CEF-T changes with increasing doses of ADR-529 and increasing doses of epirubicin and (2) whether the pharmacokinetics of epirubicin in the same combinations is altered with the administration of increasing doses of ADR-529. A total of 82 patients were included. A crossover study including 16 of the patients showed no significant difference in epirubicin pharmacokinetic parameters when epirubicin was given with or without concomitant administration of ADR-529. Apart from minor changes in the distributional half-lives, the pharmacokinetic parameters of epirubicin were not altered with increasing doses of ADR-529, nor were the pharmacokinetic parameters of ADR-529 itself. Escalating doses of epirubicin did not significantly alter the pharmacokinetic parameters of ADR-529 with the exception of a 30% increase in the terminal half-life and a decrease in total body clearance when the epirubicin dose was raised from 60 to 100 mg/m2. We conclude that concomitant administration of ADR-529 does not alter the distribution and elimination of epirubicin in doses suitable for preventing the anthracycline-induced cardiotoxicity.  相似文献   
16.
17.
Carter JW  Mirza SK  Tencer AF  Ching RP 《Spine》2000,25(1):46-54
STUDY DESIGN: A laboratory study using isolated ligamentous human cadaveric cervical spines to investigate canal occlusion during (transient) and after (steady-state) axial compressive fracture. OBJECTIVES: To determine whether differences exist between transient and postinjury canal occlusion under axial compressive loading, and to examine the effect of loading rate on canal occlusion. SUMMARY OF BACKGROUND DATA: Prior studies have shown no correlation between neurologic deficit and canal occlusion measurements made on radiographs and computed tomography scans. The authors hypothesized that postinjury radiographic assessment does not provide an appreciation for the transient occlusion that occurs during the traumatic fracture event, which may significantly affect the neurologic outcome. METHODS: Twelve human cervical spines were instrumented with a specially designed canal occlusion transducer, which dynamically monitored canal occlusion during axial compressive impact. Six specimens were subjected to a fast-loading rate (time to peak load, approximately 20 msec), and the other six were subjected to a slow-loading rate (time to peak load, approximately 250 msec). After impact, two different postinjury canal occlusion measurements were performed. RESULTS: Each of the six specimens subjected to the fast-loading rate incurred burst fractures, whereas the slow-loading rate produced six wedge-compression fractures. For the fast-rate group, the postinjury occlusion-measurements were significantly smaller than the transient occlusion. In contrast, transient occlusion was not found to be significantly different from postinjury occlusion in the slow-rate group. All of the comparisons between loading rate groups showed significant differences, with the fast-rate fractures producing larger amounts of canal occlusion in every category. CONCLUSIONS: The findings indicate that even if canal occlusion could be measured immediately after axial compressive trauma, the measurement would underestimate the maximal amount of transient canal occlusion. Therefore, postinjury measurement of canal occlusion may indicate a smaller degree of neurologic deficit than what might be expected if the transient occlusion could be measured.  相似文献   
18.
19.
回春液补肾助阳药效学的实验研究   总被引:2,自引:0,他引:2  
回春液由人参、鹿茸、貂鞭等名贵中药组成。有补肾助阳,填精益气等功效。药效学研究证实,该药有促进幼鼠发育及增加去势大鼠前列腺——精液囊的重量,亦显著增加小鼠血红蛋白的含量,表明回春液有雄性激素样作用。  相似文献   
20.
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