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   8524篇
  免费   945篇
  国内免费   12篇
耳鼻咽喉   77篇
儿科学   267篇
妇产科学   188篇
基础医学   1182篇
口腔科学   284篇
临床医学   953篇
内科学   1611篇
皮肤病学   90篇
神经病学   883篇
特种医学   259篇
外科学   1190篇
综合类   325篇
一般理论   7篇
预防医学   969篇
眼科学   269篇
药学   517篇
中国医学   2篇
肿瘤学   408篇
  2021年   131篇
  2020年   105篇
  2019年   148篇
  2018年   155篇
  2017年   132篇
  2016年   109篇
  2015年   132篇
  2014年   182篇
  2013年   325篇
  2012年   387篇
  2011年   415篇
  2010年   220篇
  2009年   213篇
  2008年   364篇
  2007年   377篇
  2006年   393篇
  2005年   364篇
  2004年   351篇
  2003年   277篇
  2002年   305篇
  2001年   278篇
  2000年   274篇
  1999年   252篇
  1998年   95篇
  1997年   91篇
  1996年   95篇
  1995年   79篇
  1994年   79篇
  1993年   73篇
  1992年   206篇
  1991年   180篇
  1990年   204篇
  1989年   200篇
  1988年   189篇
  1987年   147篇
  1986年   150篇
  1985年   161篇
  1984年   112篇
  1983年   108篇
  1982年   77篇
  1981年   60篇
  1979年   115篇
  1978年   97篇
  1977年   78篇
  1976年   65篇
  1975年   60篇
  1974年   71篇
  1973年   95篇
  1972年   87篇
  1971年   75篇
排序方式: 共有9481条查询结果,搜索用时 15 毫秒
71.
On September 6, 1984, industrial bans were placed on the movement of linen within The Royal Melbourne Hospital. Initially, linen was stored in ward areas and, later, on hospital balconies. The dispute was not settled for 14 days; by this time, 25 beds and the Emergency Department had been closed. Stockpiled "soiled" and "infectious" linen bags posed a major safety risk. Once the bans were lifted, linen was removed and laundered under supervision, according to a carefully planned programme, in order to minimize the exposure of patients and staff members to potential cross-infection. Recommendations are made to cover infection control aspects associated with industrial disputes of this nature.  相似文献   
72.
73.
74.
Rabbit antithymocyte globulin, a "custom-made" pan-anti-T-cell antibody produced in rabbits, is currently being evaluated in the United States and may, within several years, become approved by the Food and Drug Administration. Because we have used this agent for induction of immunosuppression for 10 years in cardiac recipients and because the results appear to be more favorable than those obtained with other agents (horse antithymocyte globulin, antilymphocyte globulin, OKT3), we have reviewed our experience. For the purpose of analysis, all non-bridge-to-transplant cardiac recipients have been divided into three groups on the basis of immunosuppression protocol: group I (March 1979 to January 1983), 28 patients treated with rabbit antithymocyte globulin, steroids, and azathioprine; group II (January 1983 to March 1985), 29 patients treated with rabbit antithymocyte globulin, cyclosporine, and steroids; and group III (March 1985 to January 1989), 98 patients treated with rabbit antithymocyte globulin, cyclosporine, steroids, and azathioprine. Actuarial data showed advantage for group III in survival rate (1 year 94%, 2 years 91%, 3 years 88%), freedom from rejection (30% free at 1 year), freedom from infection (50% free at 1 year), freedom from death from rejection (99% free at 1 year), and freedom from death from infection (97% freedom at 1 year). Actuarial survival rates and freedom from death from rejection and infection are comparable for any of our groups with contemporary published data. In the past 3 years, we have had no death from acute rejection or from posttransplant infection. Time-related rates of infection by etiologic agents have shown a significant reduction in early bacterial, viral, and nocardial infections between groups I and III. With rabbit antithymocyte globulin 200 mg intramuscularly every day for 3 days, our current protocol, T-cells are significantly reduced and local and systemic toxicity is almost unnoticeable. A progressively increasing cyclosporine dose along with rapid tapering steroid and maintenance azathioprine immunosuppressive induction appears to be the therapy of choice in cardiac transplantation.  相似文献   
75.
76.
Automated anesthesia recordkeepers have been used to monitor patients during surgery in up to 90% of cases at The Ohio State University. The record-keeping devices are complex and can be difficult to troubleshoot. The 1st-CLASS Fusion Program, an expert system shell-program, has been programmed to allow the resident or nurse anesthetist to solve the two most common types of problems associated with the recordkeeper: printer problems and patient monitor problems. Use of this program allows the resident or nurse anesthetist to troubleshoot the recordkeeper quickly and accurately and promotes in the user a sense of competence and control over the technology.  相似文献   
77.
78.
Acid etching is regarded as one of the main means of providing additional retention in aesthetic dentistry. Alternative methods of achieving bonding to tooth tissue which have been proposed include laser etching. Conflicting results on bond strength to enamel have been reported for laser etching. Here the tensile bond strength of composite resin to acid- and laser-etched enamel was measured and the topographical differences between the surfaces were evaluated using the scanning electron microscope. The laser used was a pulsed Nd-YAG laser at 10 pulses per second with a pulse length of 150s, 80mJ pulse–1, 1.064m wavelength. The results obtained indicate that the bond strength of laser-etched enamel was significantly lower than that of acid-etched enamel. In this study the difference may be attributable to the chromophore used. Variations in the rate of traverse of the laser tip across the surface did not appear to produce significant alterations in the bond strength.  相似文献   
79.
Background: Three cases of heparin-induced thrombocytopenia (HIT) were observed in patients undergoing isolated limb perfusion (ILP) with melphalan. This occurrence prompted the discontinuation of prophylactic postoperative heparin in ILP patients and its avoidance in patients undergoing isolated hepatic perfusion (IHP). The need to reassess these decisions led to a review of thrombocytopenia in both patient populations.Methods: Records of all patients treated with ILP or IHP at our institution from July 1992 through November 1996, were reviewed. Nine IHP patients were tested prospectively for heparinrelated antibodies using serum samples obtained perioperatively and during the second postoperative week.Results: Thrombocytopenia (<100,000 platelets/L) developed postoperatively in 30% of 131 ILP patients and in 77% of 56 IHP patients. No cases of HIT were identified other than the three who had been previously diagnosed. The prevalence of HIT in heparinized ILP patients was 2.8% (3/108). All nine IHP patients developed heparin-related antibodies postoperatively.Conclusions: Because the prevalence of HIT following ILP is in the range observed in other clinical settings, postoperative heparin prophylaxis is an option. However, it probably should be limited to the first week, and daily platelet counts should be reviewed for a pattern of thrombocytopenia consistent with HIT. The prevalence of heparin-related antibodies after IHP is so high that prophylactic heparin should be avoided in this setting.  相似文献   
80.
BACKGROUND: There are a variety of surgical choices for women with early-stage breast cancer, including breast-conserving surgery, mastectomy, or mastectomy plus reconstructive surgery. This report examines some of the factors that affect these choices and the costs of the various treatment options. METHODS: Data from the Virginia Cancer Registry were linked to insurance claims from the Trigon Blue Cross and Blue Shield Company for women with local and regional staged breast cancer from 1989 to 1991 in Virginia. Multivariate analyses and cost studies were performed. RESULTS: There were 592 women who underwent breast-conserving surgery (BCS, 26%), mastectomy (58%), or mastectomy plus reconstruction (16%). Increasing age reduced the use of reconstruction. The choice of reconstruction was not affected by tumor size, nodal status, or race. Sixty percent of women had immediate breast reconstruction at the time of mastectomy; the majority had the implant procedure. The cost of BCS ($21,582) was higher than that of mastectomy ($16,122, P < .01). The costs for BCS and mastectomy were significantly lower than for mastectomy plus reconstruction ($31,047, P < .05). The 2-year cost for immediate reconstruction was $8200 less than for delayed procedures and was similar to the cost of BCS. CONCLUSIONS: Age was the driving force in reconstruction decisions. Clinical factors such as tumor size and nodal status were more important for the choice between BCS and mastectomy. There are significant cost differences between the various procedures. For a similar cosmetic outcome, BCS is less expensive than breast reconstruction. When reconstruction is required, a simultaneous procedure is less expensive.  相似文献   
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