首页 | 官方网站   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   3454篇
  免费   617篇
  国内免费   28篇
医药卫生   4099篇
  2023年   104篇
  2022年   22篇
  2021年   82篇
  2020年   117篇
  2019年   37篇
  2018年   157篇
  2017年   155篇
  2016年   148篇
  2015年   155篇
  2014年   226篇
  2013年   235篇
  2012年   80篇
  2011年   91篇
  2010年   163篇
  2009年   290篇
  2008年   148篇
  2007年   81篇
  2006年   127篇
  2005年   56篇
  2004年   41篇
  2003年   47篇
  2002年   42篇
  2001年   98篇
  2000年   46篇
  1999年   96篇
  1998年   90篇
  1997年   125篇
  1996年   110篇
  1995年   111篇
  1994年   74篇
  1993年   58篇
  1992年   53篇
  1991年   35篇
  1990年   30篇
  1989年   56篇
  1988年   41篇
  1987年   34篇
  1986年   35篇
  1985年   38篇
  1984年   25篇
  1983年   24篇
  1982年   32篇
  1981年   23篇
  1980年   26篇
  1979年   14篇
  1978年   21篇
  1977年   14篇
  1976年   14篇
  1975年   21篇
  1973年   17篇
排序方式: 共有4099条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
Objectives : To investigate rates of and reasons for second and subsequent stent procedures in an unselected, “real‐world” population. Background : Repeat stenting is the primary difference reported in clinical trials of alternative revascularization strategies. The incidence, indication, and outcome for repeat stenting in contemporary practice outside the more selective populations of trials and registries has not been described. Method : All patients undergoing a first percutaneous coronary intervention (PCI) procedure with stenting from January 2001 to August 2009 (10,509) from a large UK tertiary referral and district general hospital were identified. Mortality and the incidence, timing, and indication for repeat revascularization in this population were investigated from patient records. Results : Of 10,509 patients undergoing a first PCI and stent implant 23.5% underwent repeat angiography of which 11.2% required repeat PCI and 2% coronary artery bypass grafting (median follow‐up of 3.8 years). A total of 1.3% went on to a third PCI. The commonest indication for repeat stenting was disease progression remote from the original stent (46%) and planned staged PCI (23%); 21% had a stent‐related indication. Functional assessment before repeat stenting was used in one‐third of stable patients. Mortality was 2.5% per annum. Conclusions : In contemporary practice, patients undergoing a first stenting procedure have a low subsequent mortality, and the substantial majority (86.4%) requires no further revascularization over a median 3.8 year follow‐up. For those who do require repeat stenting, this is most commonly at a site remote from the first stent. © 2012 Wiley Periodicals, Inc.  相似文献   
85.
Introduction : An optimal fluoroscopic working view projection (OP) with all three aortic sinuses aligned is crucial during trans‐catheter aortic valve implantation (TAVI). The aim of this study was to identify simple reference projection angles, which would act as a starting point for the operator to help determine OP for patients undergoing TAVI. Methods : During the period under consideration, 50 patients underwent TAVI. Procedural data and outcomes were collected prospectively on a dedicated database. Optimal angiographic deployment angles were achieved for all patients by starting in an anteroposterior caudal 15 degrees projection and then adjusting according to the initial image, with multiple small volume contrast injections undertaken to determine when all three aortic cusps were aligned (OP). Results : OP angles for the 50 cases were plotted on a graph. After normality testing confirmed that all angles were normally distributed, regression analysis enabled a regression line to be calculated. The equation for the regression line was defined as cranial/caudal intercept ?16.4 ± 1.5 (SE of the coefficient), P < 0.0001, slope of regression line LAO/RAO + 0.53 ± 0.1 (SE of the coefficient SE), P < 0.0001). Conclusions : As the regression line and its equation represents an acceptable estimate of the true relationship between Cranial/Caudal and LAO/RAO, to determine OP while remaining close to the regression line we suggest starting in LAO = 8.9, Caudal = ?11.4 (which represent the mean values of these two variables), and then increasing the caudal angle by approximately 0.5 degrees for every increase of 1 degree of the LAO angle or decreasing the caudal angle by 0.53 degrees for every decrease of 1 degree in LAO until all three aortic sinuses are in line which represents OP. © 2012 Wiley Periodicals, Inc.  相似文献   
86.

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   
87.
88.
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease in adults. The biologic basis of ALS remains unknown. However, ALS research has taken a dramatic turn over the past 4 years. Ground breaking discoveries of mutations of genes that encode RNA processing proteins, and demonstration that abnormal aggregates of these and other proteins precede motor neuron loss in familial and sporadic ALS, have initiated a paradigm shift in understanding the pathogenic mechanisms of ALS. Curiously, some of these RNA binding proteins have prion‐like domains, with a propensity to self‐aggregation. The emerging hypothesis that a focal cascade of toxic protein aggregates, and their consequent non–cell‐autonomous spread to neighborhood groups of neurons, fits the classical temporo‐spatial progression of ALS. This article reviews the current research efforts toward understanding the role of RNA‐processing regulation and protein aggregates in ALS. Muscle Nerve 47:330‐338, 2013  相似文献   
89.
90.
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-23

京公网安备 11010802026262号