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   22835篇
  免费   6096篇
  国内免费   126篇
耳鼻咽喉   637篇
儿科学   651篇
妇产科学   755篇
基础医学   546篇
口腔科学   2674篇
临床医学   4283篇
内科学   5407篇
皮肤病学   483篇
神经病学   1901篇
特种医学   1061篇
外科学   4173篇
综合类   77篇
现状与发展   12篇
预防医学   2885篇
眼科学   360篇
药学   388篇
中国医学   6篇
肿瘤学   2758篇
  2024年   163篇
  2023年   1097篇
  2022年   369篇
  2021年   658篇
  2020年   1230篇
  2019年   493篇
  2018年   1364篇
  2017年   1311篇
  2016年   1534篇
  2015年   1580篇
  2014年   2028篇
  2013年   2423篇
  2012年   872篇
  2011年   790篇
  2010年   1400篇
  2009年   1987篇
  2008年   802篇
  2007年   565篇
  2006年   712篇
  2005年   521篇
  2004年   377篇
  2003年   355篇
  2002年   311篇
  2001年   436篇
  2000年   338篇
  1999年   422篇
  1998年   511篇
  1997年   496篇
  1996年   557篇
  1995年   404篇
  1994年   314篇
  1993年   276篇
  1992年   205篇
  1991年   184篇
  1990年   164篇
  1989年   182篇
  1988年   157篇
  1987年   170篇
  1986年   128篇
  1985年   139篇
  1984年   99篇
  1983年   120篇
  1982年   100篇
  1981年   82篇
  1980年   59篇
  1979年   54篇
  1978年   55篇
  1977年   59篇
  1976年   48篇
  1973年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
With the introduction of more potent immunosuppressive agents, rejection has decreased in simultaneous pancreas/kidney transplant (SPK) recipients. However, as a consequence, opportunistic infections have increased. The purpose of this report is to outline the course of SPK patients who developed polyomavirus-associated nephropathy (PVAN). A retrospective review of 146 consecutive SPK recipients from January 1, 1996 to December 31, 2002 was performed. Immunosuppression, rejection and development of PVAN were reviewed. Nine patients were identified. All received induction with either OKT3 or thymoglobulin. Immunosuppression included tacrolimus/cyclosporine, MMF/azathioprine and sirolimus/prednisone. Two patients were treated for kidney rejection prior to the diagnosis of PVAN. Time to diagnosis was an average of 359.3 days post-transplantation. Immunosuppression was decreased but five ultimately lost function. However, none developed pancreatic abnormalities as demonstrated by normal glucose and amylase. Two underwent renal retransplantation after PVAN diagnosis and both have normal kidney function. PVAN was the leading cause of renal loss in SPK patients in the first 2 years after transplantation and is a serious concern for SPK recipients. The pancreas, however, is spared from evidence of infection, and no pancreatic rejection occurred when immunosuppression was decreased.  相似文献   
93.
OBJECTIVES: To determine electrocardiogram (ECG) predictors of positive cardiac markers and short-term adverse cardiac events in an undifferentiated chest pain population presenting to emergency departments (EDs). The authors hypothesized that specific ECG findings, other than those previously identified in higher-risk populations, would be predictive of cardiac outcomes and positive cardiac markers. METHODS: This study used data from a prospectively collected, retrospectively analyzed Internet-based data registry of undifferentiated chest pain patients (i*trACS). Logistic regression modeling was performed to determine the ECG findings that were predictive of 1) positive cardiac markers and 2) short-term adverse cardiac events. RESULTS: ST-segment elevation (STE), ST-segment depression (STD), pathological Q-waves (PQW), and T-wave inversion were associated with increased odds of percutaneous coronary intervention or catheterization, myocardial infarction, or coronary artery bypass grafting. The odds of creatine kinase-MB (CK-MB) measuring positive were increased if STE, STD, or PQW were present [odds ratio (OR) 2.495, 2.582, and 1.295, respectively]. A right bundle branch block tended to decrease the odds of CK-MB measuring positive (OR 0.658). A similar pattern of results was observed for troponin I (OR 3.608 for STE, 3.72 for STD, 1.538 for PQW). Troponin T showed an increased odds of measuring positive if any of STE, STD, left bundle branch block, or T-wave inversion were evident (OR 2.313, 2.816, 1.80, and 1.449, respectively). CONCLUSIONS: Initial ECG criteria can be used to predict short-term cardiac outcomes and positive cardiac markers. These findings can be important aids in the risk-stratification and aggressive treatment regimens of chest pain patients presenting to EDs.  相似文献   
94.
HIV-infected patients are increasingly referred for kidney transplantation, and may be at an increased risk for rejection. Treatment for rejection frequently includes thymoglobulin. We studied thymoglobulin's effect on CD4+ T-cell count, risk of infection and rejection reversal in 20 consecutive HIV-infected kidney recipients. All patients used antiretroviral therapy and opportunistic infection prophylaxis. Maintenance immunosuppression consisted of prednisone, mycophenolate mofetil and cyclosporine. Eleven patients received thymoglobulin (7 for rejection and 4 for delayed/slow graft function) while 9 did not. These two groups were similar in age, gender, race, donor characteristics and immunosuppression. Mean CD4+ T-cell counts remained stable in patients who did not receive thymoglobulin, but became profoundly suppressed in those who did, decreasing from 475 +/- 192 to 9 +/- 10 cells/microL (p < 0.001). Recovery time ranged from 3 weeks to 2 years despite effective HIV suppression. Although opportunistic infections were successfully suppressed, low CD4+ T-cell count was associated with increased risk of serious infections requiring hospitalization. Rejection reversed in 6 of 7 patients receiving thymoglobulin. We conclude that thymoglobulin reverses acute rejection in HIV-infected kidney recipients, but produces profound and long-lasting suppression of the CD4+ T-cell count associated with increased risk of infections requiring hospitalization.  相似文献   
95.
96.
背景:儿童和青少年超重和肥胖正迅速增加。在该人群,单纯行为疗法减肥及维持体重下降的效果有限,但是对药物治疗尚未进行广泛的研究。 目的:确定奥利州他(Orlistat)在青少年体重治疗方面的效果及其安个性。 设计、地点和病例:于美国和加拿大32个中心、539例肥胖青少年(12—16岁;体重指数[body mass index,BMI]在第95百分化之上≥2单位)进行的多ln0、54剧(2000年8月至2002年10月)随机双盲研究。 干预:给予奥利司他(n=357)或安慰剂(n=182)120mg,每口3次,持续1年;加适度低热卡饮食(脂肪占30%)、运动和行为治疗。 主要观察指标:BMI变化;二级指标包括腰围和髋用、体重下降、脂质测量以及机体对口服葡萄糖的血糖和胰岛素反心。 结果:至12周时,两组BMI均有下降;此后,奥利司他组体重维持稳定而安慰剂组则超过基线。研究结束时,奥利司他组BMI下降0.55。而安慰剂组则增加0.31(P=0.001)。与安慰剂组的15.7%相比,奥利司他组26.5%的病例BMI下降≥5%(P=0.005);BMI下降≥10%者分别为4.5%和13.3%(P=0.002)。在研究结束时,奥利司他组体重增加0.53kg,安慰剂组增加3.14kg(P〈0.001)。双能X线吸收测量娃示,这种差异可用脂肪体再的变化解释。奥利司他组腰围下降,安慰剂组腰围上升(-1.33cm比+0.12cm;P〈0.05)。奥利司他组发生轻至中度胃肠道不良事件者为9%-50%,安慰剂组为1%~13%。 结论:与安慰剂比较,奥利司他与饮食、运动和行为改善联合可显著改善肥胖青少年体重的治疗。在这个青少年人群,连续使用奥利司他1年并无重要安全问题,尽管奥利司他组胃肠道不良事件较为常见。  相似文献   
97.
98.
Noninsulin dependent diabetes (type II diabetes) is a chronic disease characterized by hyperglycemia. Clients can generally be controlled by diet and exercise or a combination of diet, exercise, and oral hypoglycemic agents. When this therapy is not effective in controlling the hyperglycemia, the health care provider must choose to initiate insulin therapy. Outpatient initiation of insulin is an alternative to hospitalization in the type II diabetic client. Clinical guidelines for the initiation of insulin on an outpatient basis and management of the diabetic client are presented.  相似文献   
99.
100.
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