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   27212篇
  免费   1037篇
  国内免费   138篇
耳鼻咽喉   275篇
儿科学   554篇
妇产科学   654篇
基础医学   3446篇
口腔科学   1046篇
临床医学   1967篇
内科学   7216篇
皮肤病学   699篇
神经病学   2026篇
特种医学   501篇
外科学   4339篇
综合类   174篇
一般理论   3篇
预防医学   1937篇
眼科学   450篇
药学   1466篇
中国医学   122篇
肿瘤学   1512篇
  2024年   107篇
  2023年   227篇
  2022年   444篇
  2021年   965篇
  2020年   462篇
  2019年   922篇
  2018年   1026篇
  2017年   575篇
  2016年   588篇
  2015年   754篇
  2014年   1098篇
  2013年   1382篇
  2012年   2187篇
  2011年   2233篇
  2010年   1317篇
  2009年   1143篇
  2008年   1803篇
  2007年   1862篇
  2006年   1710篇
  2005年   1530篇
  2004年   1415篇
  2003年   1344篇
  2002年   1238篇
  2001年   157篇
  2000年   126篇
  1999年   171篇
  1998年   190篇
  1997年   146篇
  1996年   144篇
  1995年   123篇
  1994年   99篇
  1993年   85篇
  1992年   73篇
  1991年   50篇
  1990年   49篇
  1989年   38篇
  1988年   49篇
  1987年   32篇
  1986年   22篇
  1985年   38篇
  1984年   36篇
  1983年   40篇
  1982年   46篇
  1981年   45篇
  1980年   44篇
  1979年   20篇
  1978年   24篇
  1977年   27篇
  1975年   22篇
  1974年   22篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
105.
106.
107.
108.
One of the aims of laparoscopic surgery is to improve upon the results obtained by open surgery. This clearly appears to have been achieved in bariatric surgery. Two-dimensional (2-D) systems have been used to date, though new 3-dimensional (3-D) technologies have been introduced in an attempt to improve surgeon vision and thus increase the safety of the surgical techniques. Sixty obese patients underwent sleeve gastrectomy using a device equipped with 3-D optics allowing surgery to be viewed by the surgeon in 3 dimensions by using a specific monitor and wearing appropriate glasses. The mean patient age was 48.1 years. The mean weight was 114 kg (range, 92–172), with a mean body mass index (BMI) of 44 ± 5.21 kg/m2. All surgeries were performed using the 3-D system, with a mean surgical time of 71 ± 49.6 minutes and a mean hospital stay of 3.0 ± 1.2 days. Only 1 intraoperative complication was recorded: retroperitoneal bleeding on insertion of the optical trocar. Over a mean follow-up period of 12 months, the mean body weight of the patients was 88 kg (range, 71–121), with a BMI of 30.56 ± 3.98 kg/m2 and a percentage excess weight loss of 68.14% ± 7.89%. There was clear improvement of both the blood pressure and glucose levels. Three-dimensional sleeve gastrectomy is safe, viable, and fully reproducible compared with 2-D surgery, improving visualization of the surgical field, safety, and surgeon convenience. Randomized studies involving larger patient samples are needed for the comparison of results.Key words: 3-D laparoscopy, Bariatric surgery, Metabolic surgeryIn recent years, laparoscopic surgery has become clearly indicated in bariatric and metabolic surgery. This surgical technique has made it possible to reduce morbidity and mortality in comparison with conventional open surgery, and to shorten hospital stay. In addition to the usual 5-trocar technique, laparoscopic surgery has also produced satisfactory results with the single-port approach, which is regarded as less invasive and affords equivalent outcomes and improved aesthetic results.More recently, the possibility of using three-dimensional (3-D) surgery has been considered. The film Avatar (James Cameron, 2006) represented a starting point for a number of multinational medical engineering companies who launched projects that now allow us to use 3-D laparoscopic systems. This new technology offers the perception of depth, which was not previously available.Sleeve gastrectomy is one of the surgical techniques presently used to treat obesity. It was initially regarded as first-step surgery in patients with a high body mass index (BMI), before performing biliopancreatic diversion. Sleeve gastrectomy is currently considered to be a restrictive technique that can be used as a sole option in morbid obesity, even when accompanied by diabetes mellitus, as contemplated by the International Sleeve Gastrectomy Expert Panel Consensus of 2011.Three-dimensional laparoscopic sleeve gastrectomy requires 5 ports, like the two-dimensional (2-D) laparoscopic technique, and one of them must be enlarged to extract the sectioned stomach. However, 3-D visualization is very useful in all the surgical steps, as it improves spatial orientation and can increase the safety of the surgical technique.The present study analyzes the results of 3-D laparoscopic sleeve gastrectomy after a short 1-year follow-up period, with a view to evaluating its safety and feasibility in patients with severe or morbid obesity and type 2 diabetes.  相似文献   
109.
110.
BackgroundCerebral ischemia and reperfusion (I/R) induces oxidative stress and activates autophagy, leading to brain injury and neurologic deficits. Cervical vagus nerve stimulation (VNS) increases cerebral blood flow (CBF). In this study, we investigate the effect of VNS-induced CBF increase on neurologic outcomes after cardiac arrest (CA).Materials and MethodsA total of 40 male C57Bl/6 mice were subjected to ten minutes of asphyxia CA and randomized to vagus nerve isolation (VNI) or VNS treatment group. Eight mice received sham surgery and VNI. Immediately after resuscitation, 20 minutes of electrical stimulation (1 mA, 1 ms, and 10 Hz) was started in the VNS group. Electrocardiogram, blood pressure, and CBF were monitored. Neurologic and histologic outcomes were evaluated at 72 hours. Oxidative stress and autophagy were assessed at 3 hours and 24 hours after CA.ResultsBaseline characteristics were not different among groups. VNS mice had better behavioral performance (ie, open field, rotarod, and neurologic score) and less neuronal death (p < 0.05, vs VNI) in the hippocampus. CBF was significantly increased in VNS-treated mice at 20 minutes after return of spontaneous circulation (ROSC) (p < 0.05). Furthermore, levels of 8-hydroxy-2?-deoxyguanosine in the blood and autophagy-related proteins (ie, LC-3Ⅱ/Ⅰ, Beclin-1, and p62) in the brain were significantly decreased in VNS mice. Aconitase activity was also reduced, and the p-mTOR/mTOR ratio was increased in VNS mice.ConclusionsOxidative stress induced by global brain I/R following CA/ROSC leads to early excessive autophagy and impaired autophagic flux. VNS promoted CBF recovery, ameliorating these changes. Neurologic and histologic outcomes were also improved.  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