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   4841篇
  免费   344篇
  国内免费   17篇
耳鼻咽喉   17篇
儿科学   174篇
妇产科学   137篇
基础医学   458篇
口腔科学   59篇
临床医学   268篇
内科学   1538篇
皮肤病学   31篇
神经病学   180篇
特种医学   54篇
外科学   463篇
综合类   48篇
一般理论   10篇
预防医学   1382篇
眼科学   59篇
药学   131篇
中国医学   39篇
肿瘤学   154篇
  2023年   98篇
  2022年   79篇
  2021年   294篇
  2020年   262篇
  2019年   284篇
  2018年   270篇
  2017年   228篇
  2016年   264篇
  2015年   245篇
  2014年   336篇
  2013年   678篇
  2012年   214篇
  2011年   217篇
  2010年   158篇
  2009年   178篇
  2008年   190篇
  2007年   174篇
  2006年   131篇
  2005年   115篇
  2004年   86篇
  2003年   80篇
  2002年   61篇
  2001年   59篇
  2000年   43篇
  1999年   36篇
  1998年   31篇
  1997年   30篇
  1996年   25篇
  1995年   20篇
  1994年   18篇
  1993年   9篇
  1992年   18篇
  1991年   8篇
  1990年   18篇
  1989年   9篇
  1988年   9篇
  1987年   13篇
  1985年   25篇
  1984年   19篇
  1983年   8篇
  1982年   19篇
  1981年   18篇
  1980年   16篇
  1979年   13篇
  1978年   21篇
  1977年   10篇
  1976年   13篇
  1975年   15篇
  1974年   12篇
  1973年   15篇
排序方式: 共有5202条查询结果,搜索用时 31 毫秒
991.
Oral opportunistic infections developing secondary to human immunodeficiency virus (HIV) infection have been reported from the early days of the epidemic and have been classified by both the EC-Clearinghouse and the World Health Organisation (WHO). Among the fungal infections, oral candidiasis, presenting in African HIV-infected patients has been sporadically documented. We review the literature with respect to candidal carriage, oral candidiasis prevalence and the predictive value of oral candidiasis for a diagnosis of underlying HIV disease in African HIV-infected patients. The use of oral candidiasis as a marker of disease progression, the species of yeasts isolated from the oral cavity in Africa and the resistance of the yeasts to antifungal agents and treatment regimens are discussed. Orofacial lesions as manifestations of the systemic mycoses are rarely seen in isolation and few cases are reported in the literature from Africa. In spite of the high incidence of noma, tuberculosis, chronic osteomyelitis and syphilis in Africa, surprisingly there have been very few reported cases of the oral manifestations of these diseases in HIV-positive individuals. Orofacial disease in HIV-infected patients is associated with marked morbidity, which is compounded by malnutrition. The authors indicate specific research areas, initially directed at the most effective management strategies, which would complete data in this important area.  相似文献   
992.
《Injury》2016,47(4):837-841
BackgroundIntentional injuries are the result of violence. This is an important public health issue, particularly in children, and is an unaddressed problem in sub-Saharan Africa. This study sought to describe the characteristics of intentional injury, particularly physical abuse, in children presenting to our tertiary trauma centre in Lilongwe, Malawi and how they compare to children with unintentional injuries.MethodsA retrospective analysis of children (<18 years old) with traumatic injuries presenting to Kamuzu Central Hospital (KCH) in Lilongwe, Malawi from 2009 to 2013 was performed. Children with intentional and unintentional injuries were compared with bivariate analysis and multivariate logistic regression modelling.Results67,672 patients with traumatic injuries presented to KCH of which 24,365 were children. 1976 (8.1%) patients presented with intentional injury. Intentional injury patients had a higher mean age (11.1 ± 5.0 vs. 7.1 ± 4.6, p < 0.001), a greater male preponderance (72.5 vs. 63.6%, p < 0.001), were more often injured at night (38.3 vs. 20.7%, p < 0.001), and alcohol was more often involved (7.8 vs. 1.0%, p < 0.001). Multivariate logistic regression modelling showed that increasing age, male gender, and nighttime or urban setting for injury were associated with increased odds of intentional injury. Soft tissue injuries were more common in intentional injury patients (80.5 vs. 45.4%, p < 0.001) and fist punches were the most common weapon (25.6%). Most patients were discharged in both groups (89.2 vs 80.9%, p < 0.001) and overall mortality was lower for intentional injury patients (0.9 vs. 1.2%, p = 0.001). Head injury was the most common cause of death (43.8 vs. 32.2%, p < 0.001) in both groups.ConclusionsSub-Saharan African tertiary hospitals are uniquely positioned to play a pivotal role in the identification, clinical management, and alleviation of intentional injuries to children by facilitating access to social services and through prevention efforts.  相似文献   
993.
994.
995.
996.
Objectives Since emergency contraception (EC) products became available over the counter in South Africa in 2000 a number of studies have emerged. This paper reviews the growing body of literature on EC in that country.

Methods Standard computer database searches identified published articles and reports on EC in South Africa.

Results The level of awareness of EC is fairly low, especially among public sector clients. Most studies suggest that very few people have even heard of it. Several studies also indicate that provider knowledge of and attitude towards EC vary greatly. While many providers are aware of the indications and efficacy of the method, not all health care professionals are sufficiently knowledgeable and misperceptions persist. The limited knowledge of EC among health professionals may, in turn, prevent them from discussing it with clients.

Conclusion The existing literature suggests that the greater availability of EC is not sufficient to increase uptake and that interventions are needed to ensure that women become aware of this option.  相似文献   
997.
Developing countries account for a disproportionate burden of infant hearing loss globally but the prospects of the more ideal universal newborn hearing screening (UNHS) have been debated. The Joint Committee on Infant Hearing (JCIH) of USA has consistently proposed targeted newborn hearing screening (TNHS) for such countries. This study therefore set out to examine the appropriateness of JCIH risk factors as a basis for TNHS in Sub-Saharan Africa and Southeast Asia. From a review of relevant literature published in PubMed in the last 10 years, evidence on the effectiveness of TNHS based on JCIH or other risk factors is sparse or limited. Consistent with the prevailing epidemiological profile of these countries additional putative risk factors not listed or more prevalent than those listed by JCIH such as maternal hypertensive disorders in pregnancy, lack of skilled attendant at delivery, non-elective cesarean delivery and infant undernutrition have been demonstrated besides consanguinity. While TNHS has intuitive appeal in resource-poor settings, it is likely to be fraught with diverse operational constraints that could significantly curtail its effectiveness in these two regions. Well-conducted pilot UNHS studies to determine context-specific risk factors, screening efficiency and the potential trade-offs are warranted in each country prior to embarking on TNHS where UNHS is not immediately practicable.  相似文献   
998.

Objectives

Improving the quality of pediatric healthcare in the developing world poses some formidable challenges. Surgical missions aim to improve the lot of individual children, but do little to alter the wellness of the majority.

Methods

Members of the American Society of Pediatric Otolaryngology (ASPO) are working in coordination with existing programs - universities, mission hospitals and non-governmental organizations - with a focus on public health and education of local physicians.

Results

We have completed our first four visits to Ethiopia, teaching, performing surgery and building relationships.

Conclusions

We hope that by moving from the traditional surgical mission format to a long-term, integrated educational effort we can enhance otolaryngic care for children in Sub-Saharan Africa.  相似文献   
999.
Aim: To identify factors that influence adherence to short‐course antiretroviral (ARV) prophylaxis by pregnant women and mothers participating in the HIV prevention of mother to child (PMTCT) programme. Methods: The sample interviewed included 139 HIV‐positive antenatal women (mean gestational age 32 weeks; sexually transmitted diseases [STD] = 2.8, range 4–9 months) and 607 postnatal HIV‐positive women, with either having an infant aged 1–10 weeks (30.8%), 11 weeks to 6 months (36.7%) or 7–12 months (32.5%) from Nkangala district, Mpumalanga province, South Africa. Results: A large percentage of antenatal and postnatal women in this study initiated ARV prophylaxis for PMTCT or were on ARV (85.6% and 98%, respectively). Sixty‐one per cent of antenatal and 85.9% of postnatal women reported complete adherence to the appropriate medication schedule in the 4 days preceding the interview or prior to delivery. In multivariate analysis, it was found that women with higher HIV status disclosure and less discrimination were better in maternal AZT adherence, women with higher male involvement were better in maternal and infant nevirapine adherence. Conclusion: Adherence to maternal and infant dual therapy prophylaxis was found to be less than optimal. Community factors (discrimination, HIV disclosure, male involvement) contribute to adherence to short‐course ARV prophylaxis in this largely rural setting in South Africa.  相似文献   
1000.
Aim: To evaluate pediatric AntiRetroviral Treatment (ART) treatment in a resource‐limited setting. Methods: Data from a paediatric ART cohort at the All African Leprosy and Rehabilitation Centre, Addis Abeba, were analysed. Outcome measures included survival, age, gender, WHO stage, weight, regimen and CD4 cell count. Results: From April 2005 to December 2008, 482 children initiated ART. Median age was 5.9 years (IQR 3.7–9.8), and median CD4 cell count was 236 cells per mm3. Median follow‐up was 16 months (IQR = 6–24 month). Among those followed for 24 months (n = 188), 160 children were still receiving treatment, six had dropped out, eight had been transferred out, and 13 (7.5%) had died (4.0 deaths per 100 person‐years). Mortality was highest in the first 6 months resulting in a 4.3% mortality rate. Lower age and immune suppression (low CD4) were associated with mortality, while sex, drug regimen, tuberculosis at treatment initiation, application of stavudine and/or zidovudine were not. Conclusion: ART treatment of children in resource‐limited settings is possible as demonstrated by low attrition. The high proportion of malnourished children and children admitted at late stage of the disease calls for attention. Efforts to enrol more children and at an earlier stage of the disease should be promoted.  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