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   2470篇
  免费   117篇
  国内免费   30篇
耳鼻咽喉   10篇
儿科学   100篇
妇产科学   19篇
基础医学   468篇
口腔科学   114篇
临床医学   266篇
内科学   576篇
皮肤病学   120篇
神经病学   54篇
特种医学   274篇
外科学   228篇
综合类   51篇
预防医学   100篇
眼科学   27篇
药学   159篇
中国医学   3篇
肿瘤学   48篇
  2018年   38篇
  2016年   27篇
  2015年   43篇
  2014年   28篇
  2013年   96篇
  2012年   47篇
  2011年   38篇
  2010年   56篇
  2009年   52篇
  2008年   35篇
  2007年   58篇
  2006年   64篇
  2005年   36篇
  2004年   28篇
  2003年   33篇
  2002年   27篇
  2001年   37篇
  2000年   28篇
  1999年   41篇
  1998年   85篇
  1997年   95篇
  1996年   104篇
  1995年   70篇
  1994年   75篇
  1993年   76篇
  1992年   40篇
  1991年   39篇
  1990年   41篇
  1989年   68篇
  1988年   58篇
  1987年   49篇
  1986年   53篇
  1985年   38篇
  1984年   57篇
  1983年   27篇
  1982年   32篇
  1981年   37篇
  1980年   50篇
  1978年   27篇
  1977年   35篇
  1976年   38篇
  1975年   36篇
  1972年   24篇
  1970年   23篇
  1965年   50篇
  1964年   50篇
  1963年   47篇
  1962年   41篇
  1961年   40篇
  1960年   65篇
排序方式: 共有2617条查询结果,搜索用时 15 毫秒
131.
132.
133.
IntroductionWith the emergence of the COVID-19 pandemic, all elective surgery was temporarily suspended in the UK, allowing for diversion of resource to manage the anticipated surge of critically unwell patients. Continuing to deliver time-critical surgical care is important to avoid excess morbidity and mortality from pathologies unrelated to COVID-19. We describe the implementation and short-term surgical outcomes from a system to deliver time-critical elective surgical care to patients during the COVID-19 pandemic.Materials and methodsA protocol for the prioritisation and safe delivery of time-critical surgery at a COVID-19 ‘clean’ site was implemented at the Nuffield Health Exeter Hospital, an independent sector hospital in the southwest of England. Outcomes to 30 days postoperatively were recorded, including unplanned admissions after daycase surgery, readmissions and complications, as well as the incidence of perioperative COVID-19 infection in patients and staff.ResultsA total of 128 surgical procedures were performed during a 31-day period by a range of specialties including breast, plastics, urology, gynaecology, vascular and cardiology. There was one unplanned admission and and two readmissions. Six complications were identified, and all were Clavien-Dindo grade 1 or 2. All 128 patients had preoperative COVID-19 swabs, one of which was positive and the patient had their surgery delayed. Ten patients were tested for COVID-19 postoperatively, with none testing positive.ConclusionThis study has demonstrated the implementation of a safe system for delivery of time-critical elective surgical care at a COVID-19 clean site. Other healthcare providers may benefit from implementation of similar methodology as hospitals plan to restart elective surgery.  相似文献   
134.
Achondroplasia is a rare genetic disorder resulting in short‐limb skeletal dysplasia. We present the largest European population‐based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. All cases of achondroplasia notified to 28 EUROCAT registries (1991–2015) were included in the study. Prevalence, birth outcomes, prenatal diagnosis, associated anomalies, and the impact of paternal and maternal age on de novo achondroplasia were presented. The study population consisted of 434 achondroplasia cases with a prevalence of 3.72 per 100,000 births (95%CIs: 3.14–4.39). There were 350 live births, 82 terminations of pregnancy after prenatal diagnosis, and two fetal deaths. The prenatal detection rate was significantly higher in recent years (71% in 2011–2015 vs. 36% in 1991–1995). Major associated congenital anomalies were present in 10% of cases. About 20% of cases were familial. After adjusting for maternal age, fathers >34 years had a significantly higher risk of having infants with de novo achondroplasia than younger fathers. Prevalence was stable over time, but regional differences were observed. All pregnancy outcomes were included in the prevalence estimate with 80.6% being live born. The study confirmed the increased risk for older fathers of having infants with de novo achondroplasia.  相似文献   
135.
Multiple sclerosis: serial study of gadolinium-enhanced MR imaging   总被引:4,自引:0,他引:4  
Thirteen patients with definite multiple sclerosis (MS), studied 16-24 months previously with magnetic resonance (MR) imaging with and without enhancement by intravenously administered gadolinium diethylenetriaminepentaacetic acid (DTPA) dimeglumine, were reexamined with a similar protocol. Assessment of enhancement and clinical activity in both studies revealed that enhancement was observed in 13 of 14 cases in which clinical activity had changed within 4 weeks of the study and thus appeared more sensitive than clinical examination in determining active disease. The 3-minute postinjection, short repetition time image (TR) was the most efficient for depicting enhancement. Enhancing lesions (active plaques) arose from previously hyper- or isointense regions on long TR images. Previously active lesions reverted to areas of iso- or hyperintensity on long TR images. Serial comparison of long TR images in this population reveals a decrease in high-intensity lesions on long TR images in some cases and an increase in others. The findings of high-intensity regions on long TR images and previously enhancing lesions both becoming isointense suggests that transient inflammatory changes with concomitant edema without demyelination and/or with significant remyelination may occur in some MS lesions. MS lesions are dynamic; both active and inactive lesions may show dramatic change on longitudinal MR imaging studies.  相似文献   
136.
ROBERT D. KNAPP  JR.  M.D. 《Headache》1963,3(3):112-112
  相似文献   
137.
138.
139.
140.
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