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   3176篇
  免费   380篇
  国内免费   8篇
耳鼻咽喉   13篇
儿科学   129篇
妇产科学   297篇
基础医学   265篇
口腔科学   44篇
临床医学   945篇
内科学   486篇
皮肤病学   80篇
神经病学   77篇
特种医学   279篇
外科学   266篇
综合类   100篇
预防医学   189篇
眼科学   95篇
药学   185篇
中国医学   4篇
肿瘤学   110篇
  2023年   57篇
  2022年   29篇
  2021年   60篇
  2020年   68篇
  2019年   49篇
  2018年   109篇
  2017年   131篇
  2016年   120篇
  2015年   144篇
  2014年   172篇
  2013年   153篇
  2012年   147篇
  2011年   164篇
  2010年   155篇
  2009年   144篇
  2008年   128篇
  2007年   116篇
  2006年   115篇
  2005年   80篇
  2004年   79篇
  2003年   90篇
  2002年   71篇
  2001年   73篇
  2000年   33篇
  1999年   68篇
  1998年   109篇
  1997年   117篇
  1996年   113篇
  1995年   101篇
  1994年   70篇
  1993年   56篇
  1992年   29篇
  1991年   38篇
  1990年   23篇
  1989年   40篇
  1988年   42篇
  1987年   23篇
  1986年   28篇
  1985年   31篇
  1984年   20篇
  1983年   24篇
  1982年   20篇
  1981年   12篇
  1980年   16篇
  1979年   6篇
  1978年   18篇
  1977年   18篇
  1976年   18篇
  1975年   19篇
  1973年   5篇
排序方式: 共有3564条查询结果,搜索用时 0 毫秒
1.
2.
BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials.  相似文献   
3.
Peritonitis is a common emergency encountered by surgeons the world over. This paper aims to provide an overview of the spectrum of peritonitis seen in the East. Studies dealing with the overall spectrum of secondary peritonitis in various countries of this region were identified using Pubmed and Google. These were analyzed for the site and cause of perforation and the mortality. It was observed that perforation of duodenal ulcers was the most the commonly encountered perforations. These are followed by small bowel and appendicular perforations. Colonic perforations were uncommon. The overall mortality ranges between 6–27%.  相似文献   
4.
双波长紫外分光光度法测定贝母中腺苷和胸苷的含量   总被引:4,自引:0,他引:4  
将4种贝母的甲醇提取物经薄层色谱法粗分离后,直接用双波长紫外分光光度法测定其含量。结果表明,该方法线性关系好,腺苷和胸苷标准曲线的相关系数均为0.9999,同时也发现平贝、炉贝和伊贝中腺苷都占核苷总量60%以上,而浙贝中仅占约40%,提示贝母生药的抗凝血活性可能与贝母中核苷类化合物的种类和含量的差别有关。  相似文献   
5.
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.  相似文献   
6.
7.
8.
Duodenogastric reflux (DGR) has been implicated in several disease processes. The present study was carried out to document the incidence and evaluate the clinical significance of DGR after choledochoduodenostomy (CDD). A total of 13 patients who had undergone cholecystectomy with a standard side-to-side CDD for choledocholithiasis or chronic pancreatitis were studied by symptom evaluation, scintigraphy, endoscopy, and gastric mucosal histology at least 6 months after surgery. The scintigraphic findings were then compared with those of 10 patients who had undergone cholecystectomy alone. Only two patients (15%) had mild dyspeptic symptoms. The incidence of DGR after CDD was 69% compared to 20% in the cholecystectomy alone group (P < 0.05). In the majority of patients the DGR was only mild to moderate and the severity correlated well with the degree of endoscopic gastritis, but not with the clinical symptoms or histological findings. These results indicate that while CDD is associated with a high incidence of DGR, its occurrence does not produce significant clinical symptoms.  相似文献   
9.
10.
Pancreas-sparing duodenectomy for trauma.   总被引:1,自引:0,他引:1  
The application of pancreas sparing duodenectomy (PSD) in extensive duodenal trauma has not been fully explored. We report 3 caes of duodenal trauma in whom PSD was performed successfully and with good results.  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