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   6446篇
  免费   719篇
  国内免费   32篇
耳鼻咽喉   32篇
儿科学   153篇
妇产科学   115篇
基础医学   893篇
口腔科学   103篇
临床医学   809篇
内科学   1599篇
皮肤病学   241篇
神经病学   554篇
特种医学   382篇
外科学   591篇
综合类   90篇
一般理论   2篇
预防医学   891篇
眼科学   55篇
药学   351篇
中国医学   3篇
肿瘤学   333篇
  2023年   75篇
  2022年   35篇
  2021年   73篇
  2020年   94篇
  2019年   81篇
  2018年   140篇
  2017年   103篇
  2016年   137篇
  2015年   149篇
  2014年   211篇
  2013年   289篇
  2012年   336篇
  2011年   371篇
  2010年   201篇
  2009年   203篇
  2008年   312篇
  2007年   312篇
  2006年   283篇
  2005年   260篇
  2004年   270篇
  2003年   215篇
  2002年   225篇
  2001年   215篇
  2000年   166篇
  1999年   184篇
  1998年   143篇
  1997年   125篇
  1996年   126篇
  1995年   108篇
  1994年   106篇
  1993年   85篇
  1992年   105篇
  1991年   86篇
  1990年   103篇
  1989年   133篇
  1988年   104篇
  1987年   104篇
  1986年   98篇
  1985年   88篇
  1984年   55篇
  1983年   53篇
  1982年   47篇
  1981年   49篇
  1979年   52篇
  1978年   32篇
  1977年   41篇
  1976年   41篇
  1975年   34篇
  1973年   34篇
  1971年   38篇
排序方式: 共有7197条查询结果,搜索用时 31 毫秒
11.
AD  Giannoukas  N  Labropoulos  FCT  Smith  GS  Venables  JD  Beard  武婕 《中华脑血管病论坛》2005,3(5):555-560
目的由于卒中风险随着狭窄严重程度的增加而升高,因此认为颈内动脉(ICA)接近闭塞患者的卒中风险很高。在现有的随机试验中,还没有专门针对这种情况进行探讨,因此其处理尚存在争汶。方法:对相关文献进行系统评价。结果:对ICA接近闭塞患者的处理还存在争议:一些学者支持进行干预,而另一些学者则认为存在风险或没有益处而反对进行干预。在ICA接近闭塞的有症状患者中进行一项比较外科治疗与最佳内科治疗的多中心前瞻性随机试验似乎非常困难,因为这类研究需要大量的患者。尽管如此,基于目前的证据,似乎很难拒绝手术治疗。结论:由于目前对ICA接近闭塞患者的最佳处理方案仍存在着争议,因此需要前瞻性观察性研究以证实其在有症状和无症状人群中的患病率以及相关的卒中风险。基于目前的证据,大多数医疗中心选择手术治疗,但它相对干内科治疗的特粱尚右待证章.  相似文献   
12.
13.
We surveyed 655 health professionals affiliated with tertiary level neonatal intensive care units in Canada and the United States to define an expanded role for nurses in neonatology and to determine the educational requirements for the role. The role, comprising advanced clinical practice, educational, research, and administrative responsibilities, is a blend of nurse practitioner and clinical nurse specialist activities. Based on survey findings, a neonatal stream within the existing Master of Health Sciences program at McMaster University was developed. To date, 15 clinical nurse specialists/neonatal practitioners (CNS/NPs) are employed in five neonatal intensive care units in Ontario and other related institutions. A randomized trial to evaluate these individuals is in progress.  相似文献   
14.
Newly graduated nurses often finish orientation and then believe they still need more support and mentoring than is available. Retention rates suffer as they think it must be better elsewhere. This article reports a community hospital's implementation of an education-based preceptor program. A convenience sample of 40 new graduates participated in the study. Qualitative and quantitative findings indicate a high level of satisfaction (mean visual analogue scale score 93.7), 29% increase in retention, and 9.5% decrease in vacancy.  相似文献   
15.
16.
17.
18.
The evolution of a collagen/vicryl composite membrane designed as a prosthetic material for use in urinary tract surgery is described. The early experiments in which collagen film alone was used to repair experimental ureterotomies are reviewed together with our first experiments with the collagen/vicryl prosthesis in the repair of partial nephrectomies and of full thickness defects created in the urinary bladder of experimental rabbits. These early results led to the preparation of a composite using a more highly purified collagen and employing a method of sterilisation (gamma irradiation) which would be acceptable for regular use in medical products. The results of a further series of partial nephrectomy and full thickness bladder repairs show that irradiation does not compromise the efficacy of the collagen/vicryl composite in vivo.  相似文献   
19.
A 28-year-old woman with pulmonary atresia underwent a modified Fontan procedure that utilized a valved aortic homograft; she developed stenosis of the distal anastomosis between the homograft and the pulmonary artery. Because of the increased risk of reoperation, balloon angioplasty of this stenotic lesion was performed successfully. In the subsequent 11 months she has remained asymptomatic. Balloon angioplasty was a successful alternative to reoperation in this patient.  相似文献   
20.
OBJECTIVE: To investigate the effect of screening specimens and different criteria for exclusion of duplicate isolates when surveillance of antimicrobial resistances is performed. MATERIALS AND METHODS: Trends in resistance were analysed for recent isolates of selected organisms from Guy's and St Thomas' Hospitals with the use of various criteria for the exclusion of duplicates, including time since the last isolate and antibiogram pattern, and the effect of excluding screening specimens. RESULTS: There was a significant difference of about 8% in the apparent frequency of methicillin resistance in Staphylococcus aureus in inpatients if the time limit for duplicates was set at 5 rather than 30 days; it was about 10% if a 5 day limit was compared with a 365 day limit. There was also a significant difference, of 6-10%, in apparent resistance frequencies if isolates from screening specimens were excluded. Apparent gentamicin resistance rates in Klebsiella spp. varied between 11% and 28%, and the number of apparent patient isolates of gentamicinresistant organisms varied by up to 35%, depending on the duplicate exclusion criteria chosen. Effects were smaller, though still significant, for vancomycin resistance in Enterococcus spp. There was little effect for amoxicillin or cefuroxime resistance in Escherichia coli isolates from general practitioners, where the proportion of duplicates was small. CONCLUSION: Improved surveillance of antibiotic resistance is needed. However, care needs to be taken in setting the criteria for classifying isolates as duplicates and in comparing results where these criteria may be different or unknown.  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