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   2344篇
  免费   208篇
  国内免费   2篇
耳鼻咽喉   25篇
儿科学   75篇
妇产科学   58篇
基础医学   351篇
口腔科学   46篇
临床医学   238篇
内科学   297篇
皮肤病学   34篇
神经病学   160篇
特种医学   267篇
外科学   330篇
综合类   34篇
一般理论   1篇
预防医学   224篇
眼科学   23篇
药学   200篇
中国医学   5篇
肿瘤学   186篇
  2022年   17篇
  2021年   27篇
  2019年   27篇
  2018年   30篇
  2017年   36篇
  2016年   35篇
  2015年   48篇
  2014年   49篇
  2013年   66篇
  2012年   98篇
  2011年   89篇
  2010年   64篇
  2009年   62篇
  2008年   98篇
  2007年   128篇
  2006年   94篇
  2005年   112篇
  2004年   102篇
  2003年   85篇
  2002年   91篇
  2001年   70篇
  2000年   94篇
  1999年   98篇
  1998年   31篇
  1997年   31篇
  1996年   35篇
  1995年   20篇
  1994年   17篇
  1993年   28篇
  1992年   56篇
  1991年   53篇
  1990年   41篇
  1989年   48篇
  1988年   36篇
  1987年   39篇
  1986年   35篇
  1985年   43篇
  1984年   28篇
  1983年   20篇
  1982年   20篇
  1981年   21篇
  1980年   24篇
  1979年   24篇
  1978年   33篇
  1977年   17篇
  1976年   24篇
  1975年   19篇
  1973年   17篇
  1972年   18篇
  1970年   24篇
排序方式: 共有2554条查询结果,搜索用时 18 毫秒
1.
2.
We have carried out a prospective randomised, single blind clinical trial to investigate the effect of continuous passive motion on range of knee flexion, lack of extension, pain levels and analgesic use after total knee replacement surgery. 85 subjects were randomly allocated to control or study group. All subjects followed the existing rehabilitation protocol, which permits immediate active range of motion exercises and mobilisation with the study group using continuous passive motion for 1 h, twice a day. Outcome measures employed were range of motion, pain assessed on a visual analogue scale and analgesic use according to the WHO ladder. Blinded evaluation was carried out preoperatively, at time of discharge from hospital, 6 weeks, 6 and 12 months postoperation. No significant difference was observed between groups at all time intervals for each outcome variable using Wilcoxon Rank sum tests. The results substantiate previous findings that short duration continuous passive motion following total knee arthroplasty does not influence outcome of range of motion or reported pain.  相似文献   
3.
4.
The anticancer agent temozolomide labeled with 13C (8-Carbamoyl-3-13C-methylimidazo-[5,1-d]-1,2,3,5-tetrazin-4-(3H)-one), was noninvasively detected in subcutaneous RIF-1 tumors by a selective cross polarization 13C NMR method, at a field strength of 9.4T. Pharmacokinetics of the drug, at a dose of 150 mg/kg, were determined for intravenous and intraperitoneal modes of administration (three animals per mode). The half-life of the drug in the tumors was approximately 60 min. The uptake and clearance of the drug, however, varied significantly between individual hosts, for both modes of administration. These results demonstrate the feasibility of obtaining pharmacokinetics of anticancer agents for individual tumors without the need for a label that might modify drug activity (e.g., fluorine). The variability of the in vivo measurements, even within the same tumor model, demonstrates the necessity of directly monitoring the tumor to evaluate drug pharmacokinetics.  相似文献   
5.
6.
7.
Relationship between TISS and ICU cost   总被引:3,自引:0,他引:3  
Objective: To determine whether the therapeutic intervention scoring system (TISS) reliably reflects the cost of the overall intensive care unit (ICU) population, subgroups of that population and individual ICU patients. Design: Prospective analysis of individual patient costs and comparison with TISS. Setting: Adult, 12 bedded general medical and surgical ICU in a university teaching hospital. Subjects: Two hundred fifty-seven consecutive patients including 52 coronary care (CCU), 99 cardiac surgery (CS) and 106 general ICU (GIC) cases admitted to the ICU during a 12-week period in 1994. A total of 916 TISS-scored patient days were analysed Main outcome measures: A variable cost (VC) that included consumables and service usage (nursing, physiotherapy, radiology and pathology staff costs) for individual patients was measured daily. Nursing costs were calculated in proportion to a daily nursing dependency score. A fixed cost (FC) was calculated for each patient to include medical, technical and clerical salary costs, capital equipment depreciation, equipment and central hospital costs. The correlation between cost and TISS was analysed using regression analysis. Results: For the whole group (n = 257) the average daily FC was £ 255 and daily VC was £ 541 (SEM 10); range £ 23–£ 2,806. In the patient subgroups average daily cost (FC + VC) for CCU was £ 476 (SEM 17.5), for CS £ 766 (SEM 13.8) and for GIC £ 873 (SEM 13.6). In the group as a whole, a strong correlation was demonstrated between VC and the TISS for each patient day (r = 0.87, p < 0.001) and this improved further when the total TISS score was compared with the total VC of the entire patient episode (r = 0.93, p < 0.001). This correlation was maintained in CCU, CS and GIC patient cohorts with only a small median difference between actual and predicted cost (2.2 % for GIC patients). However, in the individual patient, the range of error was up to ± 65 % of the true variable cost. For the whole group the variable cost per TISS point was £ 25. Conclusion: These results demonstrate that TISS reliably measures overall ICU population costs as well as those of the subgroups CCU, CS and GIC. However, the relationship between TISS and cost is less reliable for the individual patient. Received: 4 August 1997 Accepted: 22 March 1998  相似文献   
8.
9.
Haughton  VM; Prost  R 《Radiology》1986,158(2):461-462
The effect of chemical shift on magnetic resonance (MR) imaging of the pituitary fossa was studied. Healthy volunteers underwent conventional MR imaging of the pituitary fossa and then imaging with the frequency-encoding gradient reversed or with the phase- and frequency-encoding gradients interchanged. Comparison of the image pairs in each subject showed that the thin, black stripe evident at the water-fat interface within the pituitary fossa was altered when the gradients were changed. Therefore, the low-intensity signal within the pituitary fossa is a chemical shift misregistration effect.  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