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   3245479篇
  免费   244876篇
  国内免费   5672篇
耳鼻咽喉   44720篇
儿科学   106207篇
妇产科学   89727篇
基础医学   473645篇
口腔科学   89756篇
临床医学   295677篇
内科学   626609篇
皮肤病学   72994篇
神经病学   259967篇
特种医学   121652篇
外国民族医学   905篇
外科学   487492篇
综合类   72049篇
现状与发展   15篇
一般理论   1197篇
预防医学   256865篇
眼科学   75754篇
药学   238709篇
  10篇
中国医学   6859篇
肿瘤学   175218篇
  2021年   25747篇
  2019年   26573篇
  2018年   36895篇
  2017年   27780篇
  2016年   31374篇
  2015年   35233篇
  2014年   50043篇
  2013年   75073篇
  2012年   102810篇
  2011年   109784篇
  2010年   65000篇
  2009年   61554篇
  2008年   102234篇
  2007年   108729篇
  2006年   109908篇
  2005年   106676篇
  2004年   102243篇
  2003年   98051篇
  2002年   94712篇
  2001年   150350篇
  2000年   154099篇
  1999年   129233篇
  1998年   37786篇
  1997年   33437篇
  1996年   33494篇
  1995年   31632篇
  1994年   29186篇
  1993年   27413篇
  1992年   99449篇
  1991年   96565篇
  1990年   93875篇
  1989年   90432篇
  1988年   83284篇
  1987年   81302篇
  1986年   76231篇
  1985年   73163篇
  1984年   54934篇
  1983年   46674篇
  1982年   28116篇
  1979年   50097篇
  1978年   35577篇
  1977年   29636篇
  1976年   28263篇
  1975年   30008篇
  1974年   36236篇
  1973年   34533篇
  1972年   32541篇
  1971年   30476篇
  1970年   28352篇
  1969年   26810篇
排序方式: 共有10000条查询结果,搜索用时 865 毫秒
951.
952.
INTRODUCTION: The optimal hyperbaric oxygen (HBO2) treatment protocol for acute carbon monoxide (CO) poisoning is unknown. This is indicated by one study that found 18 different protocols to treat CO poisoning by North American multiplace hyperbaric facilities. A pilot study was conducted to evaluate the feasibility of randomizing patients to different protocols and to determine whether any large differences in clinical outcome were present between the two most common protocols. METHODS: Adult patients with accidental CO poisoning resulting in transient loss of consciousness, presentation to the emergency department within 12 hours, primary language English, high school education, and residence within 100 miles of the hyperbaric facility were recruited. Enrolled patients were randomized to one HBO2 treatment at 2.4 atmospheres absolute (atm abs) pressure with 90 minutes of 100% oxygen breathing vs. treatment by the US Air Force CO protocol (3.0 atm abs maximum pressure). A neurocognitive screening test was performed immediately after hyperbaric treatment and repeated 14-21 days later. RESULTS: From 1995 to 2002, 30 patients age 21 to 88 years were randomized, 18 to treatment at 2.4 atm abs and 12 to 3.0 atm abs. Average carboxyhemoglobin level for the population was 24.8 +/- 8.8% (mean +/- SD). Delay to hyperbaric treatment averaged 313 +/- 129 minutes. Neither variable was different between treatment groups. Six patients had abnormal neurocognitive testing immediately following hyperbaric treatment, 4 in the 2.4 atm abs group (22%) and 2 in the 3.0 atm abs group (17%) (P=0.71). One patient in each group demonstrated abnormality on delayed testing (p=0.75). One in each group did not return for follow-up. CONCLUSIONS: It is feasible to randomize CO-poisoned patients to different hyperbaric treatment protocols. Determination of differences in efficacy between treatment protocols will require a large multicenter trial with the use of detailed neurocognitive testing.  相似文献   
953.
Methods for the synthesis of new heterosystems of condensed thieno[3,2-d]-1,2,3-triazines on the basis of pyrido[2,3-b]thiophenes have been developed. The antitumor activity of the synthesized compounds was studied and several compounds possessing low toxicity and moderate antitumor activity were found. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 6, pp. 3–5, June, 2006.  相似文献   
954.
955.
956.
Vacuum-assisted closure (VAC), although a modern adjunct in wound management, has not been used previously in pyoderma gangrenosum (PG), probably to avoid the potential complications of ‘pathergy’. We would like to report our experience of VAC in three cases of PG with the relevant review of literature.  相似文献   
957.
958.
959.
960.
OBJECTIVE: Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for excision of selected benign and malignant rectal neoplasms. It is considered a safe and effective treatment but recurrence rates of 1-13% are reported for benign lesions. The aim of this study was to assess risk factors for local recurrence of benign rectal lesions and to evaluate mortality and morbidity following TEM. METHOD: Data were prospectively collected from all patients undergoing TEM for benign adenomas from January 1998 to March 2005. The procedure was performed by a single surgeon and patients were regularly followed up. RESULTS: One hundred and forty-six procedures were included, with a median patient age of 74 years (range 22-92 years). The mean lesion area was 16 cm(2) (range 0.3-150 cm(2)) and the median distance from the dentate line was 9 cm (range 0-17 cm). Immediate complications included bleeding (six) and acute urinary retention (six). There has been one (0.68%) procedure-related death. After a median follow up of 39 months (range 4-89 months) there have been seven recurrences (4.8%), recurring at a mean time of 23.3 months (range 5-48 months). Only microscopic involvement of the circumferential resection margin was found to be significantly associated with recurrence (P = 0.0059). Recurrence was not associated with age, size of lesion, previous treatment, severity of dysplasia or use of the harmonic scalpel. CONCLUSION: TEM is a safe and effective treatment for benign rectal adenomas. Circumferential resection margin involvement is associated with recurrence, which tends to occur late. Therefore extended follow up is recommended.  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