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   33783篇
  免费   2631篇
  国内免费   73篇
耳鼻咽喉   299篇
儿科学   1285篇
妇产科学   995篇
基础医学   4763篇
口腔科学   587篇
临床医学   5192篇
内科学   5514篇
皮肤病学   558篇
神经病学   3211篇
特种医学   813篇
外科学   2966篇
综合类   479篇
现状与发展   1篇
一般理论   69篇
预防医学   4487篇
眼科学   492篇
药学   2185篇
中国医学   61篇
肿瘤学   2530篇
  2023年   229篇
  2022年   324篇
  2021年   646篇
  2020年   466篇
  2019年   665篇
  2018年   721篇
  2017年   649篇
  2016年   635篇
  2015年   689篇
  2014年   996篇
  2013年   1525篇
  2012年   2209篇
  2011年   2321篇
  2010年   1229篇
  2009年   1126篇
  2008年   2002篇
  2007年   2045篇
  2006年   2069篇
  2005年   2011篇
  2004年   1985篇
  2003年   1789篇
  2002年   1745篇
  2001年   576篇
  2000年   583篇
  1999年   545篇
  1998年   415篇
  1997年   357篇
  1996年   303篇
  1995年   272篇
  1994年   238篇
  1993年   224篇
  1992年   396篇
  1991年   361篇
  1990年   293篇
  1989年   296篇
  1988年   279篇
  1987年   262篇
  1986年   245篇
  1985年   236篇
  1984年   209篇
  1983年   231篇
  1982年   205篇
  1981年   166篇
  1980年   150篇
  1979年   185篇
  1978年   142篇
  1977年   120篇
  1976年   116篇
  1974年   134篇
  1973年   102篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
971.
Objectives To describe human papillomavirus (HPV) distribution in invasive cervical carcinoma (ICC) from Mali and Senegal and to compare type‐specific relative contribution among sub‐Saharan African (SSA) countries. Methods A multicentric study was conducted to collect paraffin‐embedded blocks of ICC. Polymerase chain reaction, DNA enzyme immunoassay and line probe assay were performed for HPV detection and genotyping. Data from SSA (Mozambique, Nigeria and Uganda) and 35 other countries were compared. Results One hundred and sixty‐four ICC cases from Mali and Senegal were tested from which 138 were positive (adjusted prevalence = 86.8%; 95% CI = 79.7–91.7%). HPV16 and HPV18 accounted for 57.2% of infections and HPV45 for 16.7%. In SSA countries, HPV16 was less frequent than in the rest of the world (49.4%vs. 62.6%; P < 0.0001) but HPV18 and HPV45 were two times more frequent (19.3%vs. 9.4%; P < 0.0001 and 10.3%vs. 5.6%; P < 0.0001, respectively). There was an ecological correlation between HIV prevalence and the increase of HPV18 and the decrease of HPV45 in ICC in SSA (P = 0.037 for both). Conclusion HPV16/18/45 accounted for two‐thirds of the HPV types found in invasive cervical cancer in Mali and Senegal. Our results suggest that HIV may play a role in the underlying HPV18 and HPV45 contribution to cervical cancer, but further studies are needed to confirm this correlation.  相似文献   
972.

Background/aim

To assess the impact of open versus laparoscopic surgery in cirrhotic patients undergoing a cholecystectomy using the Nationwide Inpatient Sample (NIS).

Methods

All patients with cirrhosis who underwent a cholecystectomy (open or laparoscopic) between 2003 and 2006 were queried from the NIS. Associated complications including infection, transfusion, reoperation, liver failure and mortality were determined.

Results

A total of 3240 patients with cirrhosis underwent a cholecystectomy: 383 patients underwent an open cholecystectomy (OC) whereas 2857 patients underwent a laparoscopic cholecystectomy (LC), which included 412 patients converted (LCC) from a LC to an OC. Post-operative infection was higher in OC as opposed to a laparoscopic cholecystectomy (TLC) or LCC (3.5% versus 0.7% versus 0.2%, P < 0.0001). The need for a blood transfusion was significantly higher in the OC and LCC groups as compared with the TLC group (19.2% versus 14.4% versus 6.2%, P < 0.0001). Reoperation was more frequent after OC or LCC versus TLC (1.5% versus 2.5% versus 0.8%, P = 0.007). In-hospital mortality was higher after OC as compared with TLC and LCC (8.3% versus 1.3% versus 1.4%, P < 0.0001).

Conclusion

Patients with cirrhosis have increased in-hospital morbidity and mortality after an open as opposed to a laparoscopic or conversion to an open cholecystectomy. LC should be the preferred initial approach in cirrhotic patients.  相似文献   
973.
Percutaneous intervention is becoming an increasingly recognised modality for the management of prosthetic paravalvar leaks (PVLs) with particular utility in severely symptomatic non-surgical candidates. To date, application of this intervention has predominantly involved closure of mitral valve PVLs. Consequently, current literature on its application to aortic PVLs is limited. This article describes what we believe to be the first percutaneous closure of an aortic prosthetic PVL in Australia.  相似文献   
974.
A systematic review and meta-analysis was conducted to examine the effect of exercise training on daily physical activity (PA) in people with chronic obstructive pulmonary disease (COPD). MEDLINE, PubMed, EMBASE, CINAHL, Physiotherapy Evidence Database (PEDro) and Cochrane Central Register of Controlled Trials were searched from their inception to week 27 of 2010, using the keywords 'COPD,' 'exercise,' 'therapy' and 'physical activity.' All studies except case reports were eligible for inclusion provided they investigated the effects of ≥4 weeks of supervised exercise training on PA in patients with COPD. Study quality for the randomised trials (RTs) and single-group interventional studies was rated using the PEDro scale and Downs and Black Tool, respectively. No randomised controlled trials met our study criteria. The two RTs had a mean PEDro score of 5. The 5 single-group studies had a mean Downs and Black score of 19 ± 3. When combined, a small effect on PA outcomes was demonstrated (overall mean effect = 0.12; p = 0.01). Taken together, the RTs and single-group studies demonstrate that exercise training may confer a significant but small increase in PA.  相似文献   
975.
976.
977.
Group B Streptococcus (GBS) is a leading cause of neonatal sepsis in developed countries. Its burden in the developing world is less clear. Studies reporting neonatal GBS disease incidence from developing countries were identified from 5 literature databases. Studies were assessed with respect to case finding and culture methods. Only 20 studies were identified. The GBS incidence ranged 0-3.06 per 1000 live births with variation within and between geographic regions. All but 1 study identified GBS cases within a hospital setting, despite the potential for births in the community. Possible case under-ascertainment was only discussed in 2 studies. A higher GBS incidence was reported when using automated culture methods. Prospective, population-based surveillance is urgently needed in developing countries to provide an accurate assessment of the neonatal GBS disease burden. This will be crucial for the design of interventions, including novel vaccines, and the understanding of their potential to impact mortality from neonatal sepsis.  相似文献   
978.
979.
Background.?Severe falciparum malaria with human immunodeficiency virus (HIV) coinfection is common in settings with a high prevalence of both diseases, but there is little information on whether HIV affects the clinical presentation and outcome of severe malaria. Methods.?HIV status was assessed prospectively in hospitalized parasitemic adults and children with severe malaria in Beira, Mozambique, as part of a clinical trial comparing parenteral artesunate versus quinine (ISRCTN50258054). Clinical signs, comorbidity, complications, and disease outcome were compared according to HIV status. Results.?HIV-1 seroprevalence was 11% (74/655) in children under 15 years and 72% (49/68) in adults with severe malaria. Children with HIV coinfection presented with more severe acidosis, anemia, and respiratory distress, and higher peripheral blood parasitemia and plasma Plasmodium falciparum histidine-rich protein-2 (PfHRP2). During hospitalization, deterioration in coma score, convulsions, respiratory distress, and pneumonia were more common in HIV-coinfected children, and mortality was 26% (19/74) versus 9% (53/581) in uninfected children (P?相似文献   
980.
Evidence-based guidelines for the diagnosis and initial management of suspected acute bacterial rhinosinusitis in adults and children were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America comprising clinicians and investigators representing internal medicine, pediatrics, emergency medicine, otolaryngology, public health, epidemiology, and adult and pediatric infectious disease specialties. Recommendations for diagnosis, laboratory investigation, and empiric antimicrobial and adjunctive therapy were developed.  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