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   228501篇
  免费   6528篇
  国内免费   520篇
耳鼻咽喉   3095篇
儿科学   8365篇
妇产科学   6522篇
基础医学   29363篇
口腔科学   6418篇
临床医学   18961篇
内科学   41302篇
皮肤病学   5249篇
神经病学   14632篇
特种医学   11903篇
外国民族医学   98篇
外科学   33855篇
综合类   1649篇
一般理论   69篇
预防医学   19624篇
眼科学   5413篇
药学   15852篇
  2篇
中国医学   168篇
肿瘤学   13009篇
  2018年   4023篇
  2017年   4323篇
  2016年   3670篇
  2015年   5424篇
  2014年   5134篇
  2013年   4709篇
  2012年   11772篇
  2011年   6810篇
  2010年   3327篇
  2009年   4916篇
  2008年   4047篇
  2007年   4893篇
  2006年   5170篇
  2005年   13306篇
  2004年   14697篇
  2003年   10167篇
  2002年   5442篇
  2001年   4854篇
  2000年   2087篇
  1999年   6282篇
  1998年   976篇
  1996年   733篇
  1992年   7220篇
  1991年   7451篇
  1990年   7647篇
  1989年   7259篇
  1988年   6740篇
  1987年   6488篇
  1986年   6200篇
  1985年   5531篇
  1984年   3866篇
  1983年   3203篇
  1982年   1324篇
  1981年   1100篇
  1980年   1114篇
  1979年   4049篇
  1978年   2579篇
  1977年   1996篇
  1976年   1718篇
  1975年   2626篇
  1974年   3287篇
  1973年   2875篇
  1972年   2883篇
  1971年   2848篇
  1970年   2649篇
  1969年   2567篇
  1968年   2299篇
  1967年   2233篇
  1966年   1976篇
  1965年   1174篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Phang  P. Terry 《Abdominal imaging》2019,44(11):3740-3742
Abdominal Radiology -  相似文献   
12.
Traditionally, major complications and unanticipated admission/readmission rates were used to assess outcome after day surgery. However, in view of the relative absence of major complications the quality of recovery (QOR) should be considered one of the principal endpoints after day surgery. In our study, the level of QOR is defined by a combination of the Global Surgical Recovery (GSR) Index and the Quality of Life (QOL).The aim of this study was to analyze prevalence and predictors of QOR after day surgery on the fourth postoperative day.Elective patients scheduled for day surgery from November 2008 to April 2010 were enrolled in a prospective cohort study. Outcome parameters were measured by using questionnaire packages at 2 time points: 1 week preoperatively and 4 days postoperatively. Primary outcome parameter is the QOR and is defined as good if the GSR index >80% as well as the postoperative QOL is unchanged or improved as compared with baseline. QOR is defined as poor if both the GSR index ≤80% and if the postoperative QOL is decreased as compared with baseline. QOR is defined as intermediate in all other cases. Three logistic regression analyses were performed to determine predictors for poor QOR after day surgery.A total of 1118 patients were included. A good QOR was noted in 17.3% of patients, an intermediate QOR in 34.8%, and a poor QOR in 47.8% 4 days after day surgery. The best predictor for poor QOR after day surgery was type of surgery. Other predictors were younger age, work status, and longer duration of surgery. A history of previous surgery, expected pain (by the patient) and high long-term surgical fear were significant predictors of poor QOR in only 1 of 3 prediction models.The QOR at home 4 days after day surgery was poor in the majority of patients and showed a significant procedure-specific variation. Patients at risk for poor QOR can be identified during the preoperative period based on type of surgery, age, work status, and the duration of the surgery.  相似文献   
13.
14.
15.
The porcine circovirus type 2 (PCV2) is a swine infectious viral pathogen of great significance in global swine herds. It was recently detected at another Province of South Africa sequel to the first detection of North American‐like strain (PCV2a) at Gauteng about two decades ago, but there is a dearth of information about the genomic features and diversity of the viral strains in circulation within the country and the entire sub‐Saharan Africa region. To date, only one complete genome of the virus from South Africa is available on global data base. This current effort is therefore geared towards the full‐genome characterization of the circulating PCV2 strains in the pigs of Eastern Cape Province. With the use of conventional polymerase chain reaction method, fifteen complete PCV2 genomes were successfully amplified, sequenced and assembled from field samples obtained from non‐vaccinated pigs in the region. Neighbor Joining and Maximum Likelihood phylogenetic analyses of the ORF2 gene and full genomes unanimously showed that most of the assembled genomes (11) belong to genotype PCV2b. Furthermore, three of the characterized sequences formed clade with other reference mutant PCV2b and PCV2b subtype 1C (i.e. PCV2d) strains from the USA, China and South Korea. The last sequence, however, clustered with other reference strains belonging to PCV2 intermediate clade 2 (PCV2‐IM2), recently identified in a global PCV2 strains phylogenetic analysis. This study reports the first complete genome sequences of PCV2b, PCV2d and PCV2‐IM2 in pigs from South Africa, and it gives a possible insight into the genetic characteristics and variability of the viral strains presently in circulation within the country. It further emphasizes the need for more stringent measures in curtailing the introduction and spread of transboundary swine pathogens in the country and entire Southern African region.  相似文献   
16.

Objective

A rapid and worrying emergence of vancomycin-resistant enterococci (VRE) gut colonization is occurring worldwide and may be responsible for outbreaks, especially in healthcare facilities. While no efficient decolonization strategies are recommended, we assessed fecal microbiota transplantation (FMT) to eradicate VRE colonization.

Patients and method

Our main objective was to measure the impact of FMT on decolonization of VRE carriers, confirmed by at least two consecutive negative rectal swabs at one-week interval during a 3-month follow-up period. Patients received no antibiotic prior to the FMT.

Results

After a month only three patients remained colonized with VRE. Decolonization was associated with 87.5% (n = 7) of success after three months as only one patient remained colonized.

Conclusion

Our first results confirm that the FMT seems to be safe, with an impact on VRE colonization over time that may help control outbreaks.  相似文献   
17.
18.
About 10% of patients with Lyme disease continue to experience musculoskeletal pain and cognitive dysfunction after recommended antibiotic treatment. This condition is called post-Lyme disease syndrome (PLDS) or post-treatment Lyme disease syndrome. These two terms are used interchangeably. The pathogenesis of PLDS has been controversial. The hypothesis that patients with PLDS may harbor hidden reservoirs of Borrelia burgdorferi after their initial antibiotic treatment is difficult to accept. The prospective, double-blind studies contradict this point of view. Also, recently published research applying xenodiagnosis to PLDS supports the opinion that PLDS most likely has an autoimmune background. Lengthy courses of antibiotics are not justified in patients with PLDS because of the lack of benefit, and they are fraught with hazards. Most patients with PLDS recover from persistent symptoms with time. However, it can take months before they feel completely well.  相似文献   
19.
20.
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