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   937篇
  免费   71篇
  国内免费   28篇
儿科学   61篇
妇产科学   12篇
基础医学   103篇
口腔科学   49篇
临床医学   116篇
内科学   181篇
皮肤病学   17篇
神经病学   29篇
特种医学   253篇
外科学   65篇
综合类   19篇
预防医学   39篇
眼科学   4篇
药学   50篇
肿瘤学   38篇
  2021年   5篇
  2020年   2篇
  2019年   7篇
  2018年   16篇
  2017年   7篇
  2016年   7篇
  2015年   13篇
  2014年   19篇
  2013年   15篇
  2012年   9篇
  2011年   16篇
  2010年   33篇
  2009年   23篇
  2008年   15篇
  2007年   37篇
  2006年   25篇
  2005年   18篇
  2004年   13篇
  2003年   22篇
  2002年   17篇
  2001年   15篇
  2000年   12篇
  1999年   18篇
  1998年   60篇
  1997年   72篇
  1996年   78篇
  1995年   47篇
  1994年   39篇
  1993年   43篇
  1992年   17篇
  1991年   14篇
  1990年   19篇
  1989年   39篇
  1988年   40篇
  1987年   30篇
  1986年   31篇
  1985年   34篇
  1984年   8篇
  1983年   10篇
  1982年   13篇
  1981年   10篇
  1980年   12篇
  1979年   4篇
  1978年   4篇
  1977年   17篇
  1976年   11篇
  1975年   6篇
  1973年   5篇
  1972年   2篇
  1969年   2篇
排序方式: 共有1036条查询结果,搜索用时 0 毫秒
31.
32.
33.
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   
34.
35.
36.
Complete DNA sequences were determined for the glycoprotein B (gB) genes of four viruses from the genus Lymphocryptovirus, whose hosts had been assigned as baboon, orangutan, chimpanzee and gorilla. Together with published sequences for the gB genes of three lymphocryptoviruses, namely the human pathogen Epstein-Barr virus (EBV), a rhesus monkey virus and a marmoset virus, the sequences were used to investigate evolutionary relationships in the genus. The chimpanzee and orangutan viruses' sequences were found to be so close that it is unlikely both represent natural infections in these hosts. Phylogenetic analyses showed that the New World marmoset virus lineage formed a sister clade to that of the Old World viruses, consistent with a cospeciational separation. Within the Old World virus group, resolution of branching pattern was incomplete, and suggestive of a complex history. In particular, it was inferred that separation of the EBV lineage from that of the gorilla virus plus the chimpanzee/orangutan virus may have predated separation of the present day host species.  相似文献   
37.
38.
39.
The allelic frequency of the gene for the K variant of butyrylcholinesterase (BCHE-K) was 0.17 in 74 subjects with late-onset (age > 65 years) histopathologically diagnosed Alzheimer's disease (AD), which was higher than the frequencies in 104 elderly control subjects (0.09), in 14 early-onset cases of confirmed AD (0.07) and in 29 confirmed cases of other dementia (0.10). The association of BCHE-K with late-onset AD was limited to carriers of the epsilon 4 allele of the apolipoprotein E gene (APOE), among whom the presence of BCHE-K gave an odds ratio of confirmed late-onset AD of 6.9 (95% C.I. 1.65-29) in subjects > 65 years and of 12.8 (1.9-86) in subjects > 75 years. In APOE epsilon 4 carriers over 75 years, only 1/22 controls, compared with 10/24 confirmed late-onset AD cases, had BCHE-K. We suggest that BCHE-K, or a nearby gene on chromosome 3, acts in synergy with APOE epsilon 4 as a susceptibility gene for late-onset AD.   相似文献   
40.
It was shown recently that mutations of the ATRX gene give rise to a severe, X-linked form of syndromal mental retardation associated with alpha thalassaemia (ATR-X syndrome). In this study, we have characterised the full-length cDNA and predicted structure of the ATRX protein. Comparative analysis shows that it is an entirely new member of the SNF2 subgroup of a superfamily of proteins with similar ATPase and helicase domains. ATRX probably acts as a regulator of gene expression. Definition of its genomic structure enabled us to identify four novel splicing defects by screening 52 affected individuals. Correlation between these and previously identified mutations with variations in the ATR-X phenotype provides insights into the pathophysiology of this disease and the normal role of the ATRX protein in vivo.   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