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   5885篇
  免费   506篇
  国内免费   27篇
耳鼻咽喉   68篇
儿科学   156篇
妇产科学   120篇
基础医学   826篇
口腔科学   126篇
临床医学   542篇
内科学   1350篇
皮肤病学   253篇
神经病学   450篇
特种医学   278篇
外国民族医学   3篇
外科学   881篇
综合类   44篇
预防医学   440篇
眼科学   120篇
药学   412篇
中国医学   20篇
肿瘤学   329篇
  2023年   39篇
  2022年   77篇
  2021年   165篇
  2020年   125篇
  2019年   184篇
  2018年   206篇
  2017年   149篇
  2016年   167篇
  2015年   154篇
  2014年   206篇
  2013年   251篇
  2012年   357篇
  2011年   356篇
  2010年   224篇
  2009年   192篇
  2008年   286篇
  2007年   267篇
  2006年   274篇
  2005年   250篇
  2004年   189篇
  2003年   196篇
  2002年   176篇
  2001年   169篇
  2000年   148篇
  1999年   131篇
  1998年   65篇
  1997年   64篇
  1996年   57篇
  1995年   59篇
  1994年   59篇
  1993年   53篇
  1992年   140篇
  1991年   116篇
  1990年   82篇
  1989年   83篇
  1988年   79篇
  1987年   73篇
  1986年   83篇
  1985年   77篇
  1984年   42篇
  1983年   30篇
  1982年   31篇
  1981年   28篇
  1979年   21篇
  1978年   30篇
  1977年   17篇
  1976年   23篇
  1975年   17篇
  1974年   19篇
  1969年   22篇
排序方式: 共有6418条查询结果,搜索用时 0 毫秒
71.
72.
The effect of renal impairment (RI) on risk of bleeding and recurrent thrombosis in cancer patients treated with direct oral anticoagulants for venous thromboembolism (VTE) is undefined. We ran a prespecified analysis of the randomized Caravaggio study to evaluate the role of RI as a risk factor for bleeding or recurrence in patients treated with dalteparin or apixaban for cancer-associated VTE. RI was graded as moderate (creatinine clearance between 30-59 mL/minute; 275 patients) and mild (between 60-89 mL/minute; 444 patients). In the 1142 patients included in this analysis, the incidence of major bleeding was similar in patients with moderate vs. no or mild RI (HR 1.06-95% CI: 0.53-2.11), with no difference in the relative safety of apixaban and dalteparin. Recurrent VTE was not different in moderate vs. no or mild RI (HR=0.67, 95% CI: 0.38-1.20); in moderate RI, apixaban reduced recurrent VTE compared to dalteparin (HR=0.27, 95% CI: 0.08-0.96; P for interaction 0.1085). At multivariate analysis, no association was found between variation of renal function over time and major bleeding or recurrent VTE. Advanced or metastatic cancer was the only independent predictor of major bleeding (HR=2.84, 95% CI: 1.20-6.71), with no effect of treatment with apixaban or dalteparin. In our study, in cancer patients treated with apixaban or dalteparin, moderate RI was not associated with major bleeding or recurrent VTE. In patients with moderate renal failure, the safety profile of apixaban was confirmed with the potential for improved efficacy in comparison to dalteparin. ClinicalTrials.gov identifier: NCT03045406.  相似文献   
73.
Three experimental replications were used to test the effects of three doses (25, 50 or 75 micrograms/kg) of cholecystokinin octapeptide (CCK-8) on morphine induced changes in activity. For each dose of CCK-8, running wheel activity of golden Syrian hamsters was monitored for three hours following a series of two injections. The first injection consisted of either saline or CCK-8, the second of either saline or morphine sulfate (15 mg/kg). Thus, in each replication four groups were created: Group SAL/SAL (n = 8) received two saline injections, Group CCK/SAL (n = 8) an injection of CCK-8 followed by an injection of saline, Group SAL/MS (n = 8) an injection of saline followed by an injection of morphine and Group CCK/MS (n = 8) an injection of CCK-8 followed by an injection of morphine. Results indicated that a 25 micrograms/kg dose of CCK-8 blocked the hypoactivity elicited by morphine 40-60 min after opiate injection, whereas a 75 micrograms/kg dose of CCK-8 blocked the hyperactivity elicited by morphine 80-100 min after opiate injection. These findings are consistent with previous reports that CCK-8 antagonizes the effects of opiate agonists on a variety of behaviors and is supportive of the hypothesis that endogenous CCK-8 may antagonize endogenous opioid peptides in the control of behavior.  相似文献   
74.
75.
BackgroundOxygenated right ventricular assist device (oxyRVAD) placement has become more streamlined with the introduction of the dual-lumen pulmonary artery cannula. Peripherally cannulated oxyRVAD may provide oxygenation support with right heart support as an alternative to venoarterial extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation.MethodsA single-institution, retrospective analysis was performed on patients placed on oxyRVAD with a dual-lumen pulmonary artery cannula with the intention of bridging to lung transplantation in 2019.ResultsFour patients with idiopathic pulmonary fibrosis were placed on oxyRVAD as a bridge to transplantation. Two patients were extubated and ambulated while waiting for a lung offer, and two patients required conversion to venoarteriovenous ECMO (VAV ECMO) from oxyRVAD. The median waiting time for extracorporeal life support (ECLS) was 42 h. All patients underwent double lung transplantation. Two patients stayed on oxyRVAD, and one patient was placed on venovenous ECMO (VV ECMO) after transplantation. Primary graft dysfunction score at 72 h after transplantation was grade 1 in three patients and grade 3 in one patient.ConclusionsPeripherally cannulated oxyRVAD with percutaneous dual-lumen venous cannula could be an ambulatory bridge for lung transplantation. It is unknown whether oxyRVAD is feasible as a long-term bridge to lung transplantation.  相似文献   
76.
In this illustrative case, rheumatoid disease changed an active, self-supporting woman into a disabled, dependent and depressed person. When disease activity is continuous, early efforts to prevent severe deformity take on great urgency. It is also important to alleviate the psychosocial impact of the disease, which may well be more than even a highly motivated patient can handle alone.  相似文献   
77.
78.
79.
80.
Reverse total shoulder arthroplasty designs have gained popularity over the last few years due to their satisfactory functional results in patients with cuff‐tear arthropathy and other difficult reconstructive shoulder problems. These semiconstrained prostheses improve stability and active elevation in the absence of a functional rotator cuff by coupling a spherical glenoid component with a concave humeral component and increasing deltoid tension. Understanding the anatomy of the shoulder is critical in order to ensure secure fixation of the glenoid component, explore uncemented options for humeral component fixation, and determine the ideal soft‐tissue tension to provide the best functional outcome without increasing the risk of complications. Key anatomic elements to be considered for the successful implantation of a reverse prosthesis include the orientation and size of the glenoid vault, the scapular regions with better bone stock (coracoid, spine of the scapula), the internal geometry of the humeral medullary canal, and the effects of reverse arthroplasty on the deltoid and brachial plexus. Clin. Anat. 22:172–182, 2009. © 2008 Wiley‐Liss, Inc.  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