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   8804篇
  免费   718篇
  国内免费   20篇
耳鼻咽喉   103篇
儿科学   240篇
妇产科学   273篇
基础医学   1331篇
口腔科学   183篇
临床医学   911篇
内科学   1749篇
皮肤病学   194篇
神经病学   876篇
特种医学   290篇
外科学   1223篇
综合类   65篇
一般理论   2篇
预防医学   637篇
眼科学   222篇
药学   768篇
中国医学   18篇
肿瘤学   457篇
  2023年   57篇
  2022年   65篇
  2021年   172篇
  2020年   109篇
  2019年   165篇
  2018年   192篇
  2017年   160篇
  2016年   167篇
  2015年   167篇
  2014年   223篇
  2013年   383篇
  2012年   443篇
  2011年   450篇
  2010年   286篇
  2009年   247篇
  2008年   374篇
  2007年   419篇
  2006年   410篇
  2005年   388篇
  2004年   386篇
  2003年   358篇
  2002年   358篇
  2001年   253篇
  2000年   256篇
  1999年   204篇
  1998年   97篇
  1997年   78篇
  1996年   47篇
  1995年   78篇
  1994年   83篇
  1993年   65篇
  1992年   175篇
  1991年   202篇
  1990年   163篇
  1989年   153篇
  1988年   144篇
  1987年   156篇
  1986年   140篇
  1985年   148篇
  1984年   117篇
  1983年   95篇
  1982年   70篇
  1981年   53篇
  1980年   56篇
  1979年   122篇
  1978年   80篇
  1977年   62篇
  1976年   58篇
  1975年   48篇
  1974年   46篇
排序方式: 共有9542条查询结果,搜索用时 78 毫秒
1.
2.
Transplanting the Highly Sensitized Patient: The Emory Algorithm   总被引:4,自引:0,他引:4  
Renal transplant patients sensitized to HLA antigens comprise nearly one-third of the UNOS wait-list and receive 14% of deceased donor (DD) transplants, a rate half that of unsensitized patients. Between 1999 and 2003, we performed 492 adult renal transplants from DD; 120 patients (approximately 25%) had a panel reactive antibody (PRA) of >30%, with nearly half (n = 58) having a PRA of >80%. Our approach is based upon high-resolution solid-phase HLA antibody analysis to identify class I/II antibodies and a 'virtual crossmatch' to predict compatible donor/recipient combinations. Recipients are excluded from the United Network for Organ Sharing match run if donors possess unacceptable antigens. Thus, when sensitized patients appear on the match run, they have a high probability of a negative final crossmatch. Here, we describe our 5-year experience with this approach. Five-year graft survival ranged from 66% to 70% among unsensitized (n = 272), moderately sensitized (PRA < 30%, n = 100) and highly sensitized (>30% PRA; n = 120) patients, equal to the average national graft survival (65.7%). The application of this approach (the Emory Algorithm) provides a logical and systematic approach to improve the access of sensitized patients to DD organs and promote more equitable allocation to a highly disadvantaged group of patients awaiting renal transplantation.  相似文献   
3.
4.
Clinical versus ultrasonographic evaluation of scrotal disorders   总被引:1,自引:0,他引:1  
Clinical and ultrasonographic examinations of scrotal disorders were compared in 166 patients in order to determine their ability to distinguish between those diseases requiring surgery and those requiring clinical follow-up only. Ultrasound examinations were efficient in discriminating between normal and pathological findings. Extra-testicular lesions were readily differentiated from testicular ones. Although both clinical and ultrasonographic examinations had high sensitivity (90%) in detecting testicular cancer, the number of false positive findings was smaller after ultrasound examination. This gave a predictive value of a positive test of 53% after ultrasound examination but only 33% after clinical examination. Ultrasound examination may, therefore, reduce the number of surgical explorations in the scrotum and should be performed in patients with suspected testicular pathology based on history and palpatory findings.  相似文献   
5.
To measure prefrontal and subcortical activity during a cognitive task, we examined 19 newly diagnosed schizophrenics and patients with schizophreniform psychosis. Seven healthy volunteers served as controls. The patients were drug naive or had received neuroleptics for a few days only. Cerebral blood flow distribution was depicted by single photon emission computed tomography at rest and during activation with the Wisconsin Card Sorting Test. A significant relative activation deficit in the left inferior-prefrontal region was revealed during the Wisconsin Card Sorting Test in the patient group. Furthermore, the patients had impaired striatal suppression on the left side during the cognitive task. The test performance was significantly impaired in the patients. The inability to reduce striatal activity may be due to a lack of corticostriatal feedback during prefrontal activation.  相似文献   
6.
7.
Recurrent hip dislocation in intermediate spinal atrophy   总被引:1,自引:0,他引:1  
Recurrent hip dislocation after corrective orthopaedic surgery in children and teenagers with intermediate spinal atrophy has not been reported in the literature. Four cases with long-term follow-up are presented. These represent the only cases surgically treated in 30 years of following spinal atrophy patients. Thus, it seems significant that all hips redislocated after the surgical procedure. In addition, two patients had second operations with subsequent dislocation. Pelvic obliquity should not be the basis for the surgery, as spinal fusion is generally necessary for wheelchair users. The sagacity of performing surgery for hip dislocations is raised.  相似文献   
8.
The time aspects of daily use of a clinical database system in an endoscopy department were studied. The SADE database system for endoscopic procedures was introduced for daily use at Ullev?l Hospital on 1 January 1989. The average weekly programme of the endoscopy unit includes 57 gastroduodenoscopies, 23 colonoscopies and 12 ERCP/EPTs. During three consecutive weeks of the study the mean physician input time was 4 min 17 sec per patient (range 57 sec to 15 min), individual variation depending mainly on the extent of the report. Assistants spent a mean time of 4 min 23 sec for each patient. Thus, a total of 8 min 40 sec was spent for every patient seen. Endoscopic units should analyze their routines and needs before introducing an electronic data base manager.  相似文献   
9.
Septic pelvic thrombophlebitis is an uncommon complication in obstetrics and gynecology that may be difficult to diagnose clinically. Computed tomography (CT), an accurate and noninvasive modality, has greatly aided in the diagnosis of this disorder. In a case of septic pelvic thrombophlebitis complicating second-trimester pregnancy termination, CT enabled the correct diagnosis to be made and treatment to be initiated.  相似文献   
10.
The study presented here was performed in order to create a rule that identifies subjects at high risk for invasive candidiasis in the intensive care setting. Retrospective review and statistical modelling were carried out on 2,890 patients who stayed at least 4 days in nine hospitals in the USA and Brazil; the overall incidence of invasive candidiasis in this group was 3% (88 cases). The best performing rule was as follows: Any systemic antibiotic (days 1–3) OR presence of a central venous catheter (days 1–3) AND at least TWO of the following—total parenteral nutrition (days 1–3), any dialysis (days 1–3), any major surgery (days −7–0), pancreatitis (days −7–0), any use of steroids (days −7–3), or use of other immunosuppressive agents (days −7–0). The rate of invasive candidiasis among patients meeting the rule was 9.9%, capturing 34% of cases in the units, with the following performance: relative risk 4.36, sensitivity 0.34, specificity 0.90, positive predictive value 0.01, and negative predictive value 0.97. The rule may identify patients at high risk of invasive candidiasis. Results of this project were partially presented at Focus on Fungal Infections 14, New Orleans, LA, USA, 2004. Abstract no. 51.  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