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   5112篇
  免费   277篇
  国内免费   10篇
耳鼻咽喉   31篇
儿科学   362篇
妇产科学   80篇
基础医学   438篇
口腔科学   181篇
临床医学   323篇
内科学   1135篇
皮肤病学   269篇
神经病学   294篇
特种医学   124篇
外科学   741篇
综合类   186篇
预防医学   244篇
眼科学   308篇
药学   431篇
中国医学   13篇
肿瘤学   239篇
  2023年   38篇
  2022年   76篇
  2021年   170篇
  2020年   75篇
  2019年   152篇
  2018年   188篇
  2017年   130篇
  2016年   157篇
  2015年   165篇
  2014年   211篇
  2013年   225篇
  2012年   384篇
  2011年   447篇
  2010年   233篇
  2009年   177篇
  2008年   246篇
  2007年   284篇
  2006年   207篇
  2005年   196篇
  2004年   170篇
  2003年   142篇
  2002年   159篇
  2001年   109篇
  2000年   114篇
  1999年   90篇
  1998年   41篇
  1997年   19篇
  1996年   20篇
  1995年   35篇
  1994年   17篇
  1992年   69篇
  1991年   64篇
  1990年   41篇
  1989年   37篇
  1988年   53篇
  1987年   39篇
  1986年   32篇
  1985年   38篇
  1984年   27篇
  1983年   23篇
  1979年   22篇
  1977年   15篇
  1975年   16篇
  1974年   26篇
  1973年   15篇
  1972年   27篇
  1971年   19篇
  1970年   15篇
  1969年   16篇
  1968年   18篇
排序方式: 共有5399条查询结果,搜索用时 15 毫秒
11.
M Garg  S Rubayi  J Z Montgomerie 《Paraplegia》1992,30(10):734-739
Severe pressure ulcers in patients with spinal cord injury are frequently treated by using musculocutaneous (m-c) flap surgery. There have been few studies of the use of perioperative antibiotics to prevent postoperative infection in this setting. We reviewed 74 m-c flap surgeries in 53 patients (41 male and 12 female) from October 1989 for one year. The sites involved were ischial (31), sacral (24), trochanteric (18), deltoid (2), olecranon (1) and posterior thigh (1). An antibiotic was usually administered perioperatively for 5 days. Patients were followed for a median of 30 (8-96) weeks. Postoperative infections occurred at a median of 12 (4-25) days in 6 of 74 (8%) surgeries. The organisms cultured from the 6 infected wounds were: Bacteroides sp. (4), Proteus mirabilis (2), E. coli (2), MRSA (2), and others (6--each isolated once). These results indicate that antibiotics did not prevent postoperative infection in approximately 8% of patients undergoing m-c surgery. The frequency of isolation of Bacteroides sp. from these infections suggests that anaerobic bacteria may persist in healing pressure ulcers and perioperative antibiotics might include coverage for anaerobic bacteria.  相似文献   
12.
13.
Complete dislocation of the lens is a rare feature of Marfan's Syndrome. We observed four cases of bilateral complete posterior dislocation of the lens in established cases of Marfan's Syndrome over a one year period. An ophthalmologist may encounter infrequently, unilateral posterior dislocation in one eye and ectopia lentis in the other, but bilateral spontaneous posterior dislocation is rare. All our cases had associated vitreous degeneration with vitreous herniating into the anterior chamber. The pathogenesis of complete posterior dislocation in Marfan's Syndrome is discussed.  相似文献   
14.
Our basic techniques for the management of difficult cases of laparoscopic cholecystectomy (LC) are presented in this article. If access to Calot's triangle cannot be gained safely, dissection should be started at the fundus or body of the gallbladder (GB), rather than the neck (fundus-first method). In cases with a short and wide cystic duct, a transfixing suture should be applied for ligation instead of clipping. EndoGIA is useful for ligating and transecting this case to avoid a subsequent stricture caused by normal method of ligation. Intraoperative cholangiography should be performed near the neck of the GB in cases in which orientation is lost during dissection. More dissection should be performed in the direction of the junction of the bile ducts after orientation is regained. In cases with GB filled with stones accompanied by severe fibrosis, part of the GB is incised to remove the stones and expose the lumen of the GB. Confluence stones can be removed by placing an incision on the GB side of the junction of the duct. The incised part is closed with suture. A cystic tube (C-tube) is placed in the common bile duct through the cystic duct for decompression. In more difficult cases in which dissection cannot be started safely at any location, the body and the fundus of the GB are excised, and a drain is placed at the neck of the GB. Dissection can be carried out from the main surgeon's or the assistant's side depending on the situation, and cooperation between the two surgeons is mandatory to achieve safe LC in difficult cases. When performing the LC, one must have a low threshold for converting to open surgery if injuries cannot be managed safely.  相似文献   
15.
16.
A 12.5% corn oil-emulsion (COE) was tested as an oral contrast agent for abdominal computed tomography (CT) examinations in 100 patients. The results were compared with those obtained from another group of patients who received a conventional, high-density, oral contrast agent (2-3% iodinated solution). There was no statistically significant difference in the subjects' tolerance to the two agents (P greater than 0.05). There was, however, a significant improvement in image quality with COE (P less than 0.05). Gastrointestinal tract discrimination, and mucosal and mural visualisation was of higher quality with fat density oral contrast medium than with the high-density contrast agent. These data suggest that COE should be considered for routine use as an alternative to conventional high density oral contrast agents in upper abdominal CT.  相似文献   
17.
The contents of total lipids, total sterols, total and individual phospholipids: lysophosphatidyl choline, lysophosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl ethanolamine and alkali-stable phospholipids I and II, were significantly lower in mature cysts of Acanthamoeba culbertsoni strain A-1 than in trophozoites. The major constituent sterols of trophozoites, viz. ergosterol, 7-dehydrostigmasterol and 7,22,25-tridehydrostigmasterol which resolved as a single spot on thin-layer chromatography, disappeared in the cysts. When trophozoites grown in the presence of [14C]acetate were transferred to encystation medium, there was a steady decrease in the radioactivity in the lipids and acid-soluble fraction (glycogen) of the encysting cells while the radioactivity increased in the akali-insoluble fraction (cellulose). The activity of isocitrate lyase in the encysting cells steadily increased up to 24 h of encystation, followed by a slight decrease during 24-32 h, but the activity of isocitrate dehydrogenase steadily decreased up to 32 h of encystation, beyond which time no enzyme activity was detected. Inhibitors of isocitrate lyase, glycolate and maleate at 8.5 to 34 mM concentration inhibited encystation by 18-67%.  相似文献   
18.
Sixty-nine strains of Vibrio cholerae O1 isolated at different times were analysed to investigate if there were any differences among the O1 strains isolated before, during and after the advent of the O139 serogroup. Of the 69 O1 strains examined, 68 belonged to the Ogawa serotype while one belonged to the Inaba serotype. With the exception of one strain all other strains of V. cholerae O1 belonged to the eltor biotype. A single O1 strain isolated before the emergence of the O139 serogroup could not be classified as either eltor or classical biotype because it was resistant to both classical and eltor specific bacteriophages. Marked variations in the susceptibility to antibiotics of V. cholerae O1 isolated during the different periods were observed. In addition, strains of V. cholerae isolated after the epidemic of serogroup O139 in Calcutta showed an expanding R-type with resistance to a variety of drugs as compared to the O1 strains isolated before the advent of the O139 serogroup. From this study, it is clear that there is a substantial mobility in genetic elements of V. cholerae O1 which necessitates a continuous monitoring to keep abreast of the changing traits of the etiologic agent of cholera.  相似文献   
19.
S Garg  S N Sharma 《Die Pharmazie》1992,47(12):924-926
Aerosol formulations to act as medicated aerosol dressings have been prepared with an aim of forming a protective film over the wound after spraying combining the properties of antiseptics and hemostatics. Chlorhexidine acetate along with three hemostatics namely zinc acetate, methyl cellulose and Calendula tincture were used for the formulations. The formulations were found to be satisfactory in their performance and purpose.  相似文献   
20.
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