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   2590篇
  免费   215篇
  国内免费   91篇
耳鼻咽喉   22篇
儿科学   68篇
妇产科学   29篇
基础医学   266篇
口腔科学   120篇
临床医学   306篇
内科学   480篇
皮肤病学   69篇
神经病学   195篇
特种医学   155篇
外科学   305篇
综合类   155篇
预防医学   181篇
眼科学   179篇
药学   154篇
  1篇
中国医学   8篇
肿瘤学   203篇
  2023年   26篇
  2022年   45篇
  2021年   89篇
  2020年   61篇
  2019年   79篇
  2018年   117篇
  2017年   85篇
  2016年   80篇
  2015年   87篇
  2014年   118篇
  2013年   133篇
  2012年   147篇
  2011年   188篇
  2010年   99篇
  2009年   86篇
  2008年   129篇
  2007年   177篇
  2006年   141篇
  2005年   105篇
  2004年   110篇
  2003年   84篇
  2002年   61篇
  2001年   46篇
  2000年   45篇
  1999年   43篇
  1998年   36篇
  1997年   44篇
  1996年   33篇
  1995年   31篇
  1994年   23篇
  1993年   24篇
  1992年   21篇
  1991年   25篇
  1990年   22篇
  1989年   24篇
  1988年   37篇
  1987年   19篇
  1986年   20篇
  1985年   19篇
  1984年   9篇
  1983年   12篇
  1982年   15篇
  1981年   12篇
  1980年   12篇
  1979年   9篇
  1978年   7篇
  1977年   7篇
  1976年   13篇
  1975年   14篇
  1970年   4篇
排序方式: 共有2896条查询结果,搜索用时 0 毫秒
51.
Background: Clopidogrel is an oral agent commonly used for primary or secondary prevention of cardiovascular disease. It is associated with an increased risk of bleeding during some medical and surgical procedures. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a new bronchoscopic technique used to accurately biopsy intrathoracic structures during flexible bronchoscopy. It is currently unknown whether clopidogrel increases bleeding complications during EBUS-TBNA procedures. Objectives: To evaluate the safety of clopidogrel use in EBUS-TBNA by identifying consecutive cases of EBUS-TBNA procedures performed on patients taking clopidogrel. Methods: A retrospective review of a prospectively collected quality improvement database from 1,100 consecutive pulmonary procedures performed by an interventional pulmonologist (D.R.S.) at the University of Calgary from July 1st, 2007 to April 1st, 2011 was performed. Results: Twelve cases of EBUS-TBNA procedures performed on patients taking clopidogrel were identified. Mean age was 74 years (range 61-85). Seven patients (66.7%) were taking aspirin in addition to clopidogrel. There was no significant bleeding seen in any cases at the time of bronchoscopy and no additional complications were identified during follow-up (at least 4 weeks; median follow-up 3 months). Conclusions: This series of 12 cases suggests that EBUS-TBNA can be performed safely by experienced operators in patients taking clopidogrel. Nevertheless, until larger prospective studies confirm this hypothesis, proceeding to EBUS-TBNA without first withdrawing clopidogrel should only be performed in situations where the risk of short-term thrombosis is believed to outweigh the (theoretical) risk of bleeding.  相似文献   
52.
A technique that may effectively create a greater volume of available hard and soft tissue in the vertical plane without surgical intervention is reported and explained. Limitations of the forced eruption are also discussed. Creating an esthetic implant-supported restoration is a challenge in patients who have alveolar resorption and/or attachment loss, especially when they present with a high smile line. Many methods to augment this loss of tissue have been proposed; most involve surgical procedures to add bone or bone substitutes to compensate for the loss of alveolar tissue. This case report presents an alternative to bone augmentation procedures with the use of orthodontic tooth movement in the esthetic zone of a 62-year-old woman. The tooth movement facilitated implant placement by increasing soft-tissue volume and facial bony contours.  相似文献   
53.
Hepatitis C is a virus affecting millions worldwide and is a major health risk. With the potentially severe adverse event profile of the current backbone of therapy, interferon, there is an impetus to discover interferon free treatment regimens. With the development of new oral direct acting antivirals, interferon free regimens may be available in the next few years. This article discusses some of the preliminary data from interferon free studies.  相似文献   
54.
55.

Background

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been shown to improve survival in selected patients with peritoneal carcinomatosis. We review our institutional experience with the procedure and evaluate the overall survival (OS) and disease-free survival (DFS) rates in 100 consecutive patients.

Methods

Data were prospectively collected from 100 consecutive patients with peritoneal carcinomatosis treated by CRS and HIPEC at the National Cancer Centre Singapore between April 2001 and May 2012. Our primary end points were OS and DFS.

Results

Of the 100 patients, 84 were of Chinese ethnicity, 3 were Malay, 6 were Indian, and 7 were of other ethnicities. Primary tumors were ovarian cancer (n = 39), colorectal cancer (n = 28), primary peritoneal (n = 6), appendiceal cancer (n = 20), and mesothelioma (n = 7). Median follow-up duration was 21 months. At 5 years, the DFS was 26.3 % and OS was 50.9 %. Factors influencing OS and DFS were cytoreductive score, primary cancer, and disease-free interval of more than 12 months on univariate analysis. The only factors that remained significant for prognosis after multivariate analysis were primary cancer and cytoreductive score. Thirty-day morbidity was 56 %, and there were no 30-day mortalities.

Conclusions

CRS and HIPEC can be safely carried out in Asian patients with peritoneal carcinomatosis from ovarian, colorectal, appendiceal, mesothelioma, and primary peritoneal origins. Overall, the ovarian, appendiceal, mesothelioma, and primary peritoneal cancer patients tended to do better than the colorectal patients, but careful patient selection ensuring that optimal cytoreduction can be achieved is essential for the success of this procedure.  相似文献   
56.
57.
58.
59.
ObjectivesTo establish whether simplified adhesives (self-etch) are as clinically effective as conventional adhesives (etch-and-rinse) with multiple application steps for treatment of non-carious cervical lesions (NCCLs).Null hypothesis: there is no difference in the clinical effectiveness of the four different bonding strategies: Three-step etch-and-rinse; Two-step etch-and-rinse; Two-step self-etch; One-step self-etch for treatment of NCCLs.SourcesElectronic databases were searched including: Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. In addition, studies were identified by handsearching of selected journals.Study selectionRandomised controlled trials (RCTs) comparing at least two adhesives in non-carious cervical lesions (NCCLs), with at least 18 months follow-up were selected. The primary outcome was loss of retention/restoration loss, with marginal adaptation and marginal discolouration as secondary outcomes. Criteria for quality assessment included: random sequence generation; allocation concealment; blinding of outcome assessment; and information on withdrawals. Twenty six studies were identified that met the inclusion criteria. In general, studies were not of sufficient quality to fully address the objectives of this review.ConclusionThere is not enough evidence to support one adhesive or bonding strategy over another for treatment of NCCLs. Consequently, the null hypothesis of no difference cannot be supported or rejected with the data currently available. There is a need for better standardisation and reporting of randomised controlled trials investigating adhesive performance.Clinical significanceStudies with low overall risk of bias demonstrated good clinical performance for adhesives with all four bonding strategies. However, included studies showed wide variation between adhesives of the same category.  相似文献   
60.
Journal of Autism and Developmental Disorders - The autism-spectrum quotient (AQ) measures autistic traits and has been studied in different countries, sometimes with the English version, and...  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