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   5298篇
  免费   630篇
  国内免费   42篇
耳鼻咽喉   66篇
儿科学   162篇
妇产科学   77篇
基础医学   619篇
口腔科学   136篇
临床医学   658篇
内科学   1215篇
皮肤病学   114篇
神经病学   594篇
特种医学   430篇
外科学   769篇
综合类   157篇
一般理论   1篇
预防医学   441篇
眼科学   88篇
药学   223篇
中国医学   2篇
肿瘤学   218篇
  2023年   65篇
  2022年   43篇
  2021年   106篇
  2020年   124篇
  2019年   78篇
  2018年   151篇
  2017年   131篇
  2016年   130篇
  2015年   123篇
  2014年   183篇
  2013年   246篇
  2012年   232篇
  2011年   218篇
  2010年   167篇
  2009年   202篇
  2008年   183篇
  2007年   214篇
  2006年   221篇
  2005年   189篇
  2004年   164篇
  2003年   143篇
  2002年   138篇
  2001年   140篇
  2000年   141篇
  1999年   145篇
  1998年   127篇
  1997年   137篇
  1996年   110篇
  1995年   104篇
  1994年   75篇
  1993年   79篇
  1992年   94篇
  1991年   87篇
  1990年   96篇
  1989年   127篇
  1988年   119篇
  1987年   90篇
  1986年   83篇
  1985年   70篇
  1984年   53篇
  1983年   39篇
  1982年   41篇
  1981年   31篇
  1980年   35篇
  1979年   36篇
  1978年   41篇
  1977年   32篇
  1976年   30篇
  1974年   30篇
  1971年   26篇
排序方式: 共有5970条查询结果,搜索用时 15 毫秒
71.
BackgroundIn some settings, research methods to determine influenza vaccine effectiveness (VE) may not be appropriate because of cost, time constraints, or other factors. Administrative database analysis of viral testing results and vaccination history may be a viable alternative. This study compared VE estimates from outpatient research and administrative databases.MethodsUsing the test-negative, case-control design, data for 2017–2018 and 2018–2019 influenza seasons were collected using: 1) consent, specimen collection, RT-PCR testing and vaccine verification using multiple methods; and 2) an administrative database of outpatients with a clinical respiratory viral panel combined with electronic immunization records. Odds ratios for likelihood of influenza infection by vaccination status were calculated using multivariable logistic regression. VE = (1 ? aOR) × 100.ResultsResearch participants were significantly younger (P < 0.001), more often white (69% vs. 59%; P < 0.001) than non-white and less frequently enrolled through the emergency department (35% vs. 72%; P < 0.001) than administrative database participants. VE was significant against all influenza and influenza A in each season and both seasons combined (37–49%). Point estimate differences between methods were evident, with higher VE in the research database, but insignificant due to low sample sizes. When enrollment sites were separately analyzed, there were significant differences in VE estimates for all influenza (66% research vs. 46% administrative P < 0.001) and influenza A (67% research vs. 49% administrative; P < 0.001) in the emergency department.Conclusions:The selection of the appropriate method for determining influenza vaccine effectiveness depends on many factors, including sample size, subgroups of interest, etc., suggesting that research estimates may be more generalizable. Other advantages of research databases for VE estimates include lack of clinician-related selection bias for testing and less misclassification of vaccination status. The advantages of the administrative databases are potentially shorter time to VE results and lower cost.  相似文献   
72.
Transgender (trans) women experience barriers to access to HIV care, which result in their lower engagement in HIV prevention, treatment and support relative to cisgender people living with HIV. Studies of trans women's barriers to HIV care have predominantly focused on perspectives of trans women, while barriers are most often described at provider, organisation and/or systems levels. Comparing perspectives of trans women and service providers may promote a shared vision for achieving health equity. Thus, this qualitative study utilised focus groups and semi-structured interviews conducted 2018–2019 to understand barriers and facilitators to HIV care from the perspectives of trans women (n = 26) and service providers (n = 10). Barriers endorsed by both groups included: (a) anticipated and enacted stigma and discrimination in the provision of direct care, (b) lack of provider knowledge of HIV care needs for trans women, (c) absence of trans-specific services/organisations and (d) cisnormativity in sexual healthcare. Facilitators included: (a) provision of trans-positive trauma-informed care, (b) autonomy and choice for trans women in selecting sexual health services and (c) models for trans-affirming systems change. Each theme had significant overlap, yet nuanced perspective, between trans women and service providers. Specific recommendations to improve HIV care access for trans women are discussed. These recommendations can be used by administrators and service providers alike to work collaboratively with trans women to reduce barriers and facilitators to HIV care and ultimately to achieve health equity for trans women.  相似文献   
73.
李承青  彭德民  王彩霞 《医学争鸣》2000,21(12):1439-1439
0 引言 急性乳腺炎是产后妇女的常见病 .我们采用针头挑拨治疗急性乳腺炎 32例 ,疗效显著 .1 临床资料 患者 32例 ,年龄 2 3~ 34 (平均 2 5 .3)岁 ,均为产后哺乳产妇 .其中患乳胀痛为共有症状 .伴发热 10例 ;右侧乳腺炎 14例 ,左侧乳腺炎 16例 ,双侧乳腺炎 2例 ;外上象限胀痛 6例 ,外下象限胀痛 8例 ,内上象限胀痛 7例 ,内下象限胀痛 6例 ,二象限同时胀痛 5例 .乳头均无破损 .患者取卧位 ,显露患乳 ,乳头以碘伏严密消毒后 ,术者持五号针头以指腹常规触诊患乳 ,触摸到肿胀部位后 ,沿乳腺管走行方向找到对应的乳头腺管口 ,以针尖轻轻挑拨…  相似文献   
74.
75.
76.
77.
Acute health effects of the Sea Empress oil spill   总被引:5,自引:1,他引:4  
STUDY OBJECTIVE: To investigate whether residents in the vicinity of the Sea Empress tanker spill suffered an increase in self reported physical and psychological symptoms, which might be attributable to exposure to crude oil. DESIGN: Retrospective cohort study; postal questionnaire including demographic details, a symptom checklist, beliefs about health effects of oil and the Hospital Anxiety and Depression and SF-36 mental health scales. SETTING: Populations living in four coastal towns on the exposed south Pembrokeshire coast and two control towns on the unexposed north coast. PATIENTS: 539 exposed and 550 unexposed people sampled at random from the family health services authority age-sex register who completed questionnaires. MAIN RESULTS: Adjusted odds ratios for self reported physical symptoms; scores on the Hospital Anxiety and Depression and SF-36 mental health scales, in 1089 people who responded out of a possible 1585 (69%). CONCLUSIONS: Living in areas exposed to the crude oil spillage was significantly associated with higher anxiety and depression scores, worse mental health; and self reported headache (odds ratio = 2.35, 95% CI 1.56, 3.55), sore eyes (odds ratio = 1.96, 95% CI 1.06, 3.62), and sore throat (odds ratio = 1.70, 95% CI 1.12, 2.60) after adjusting for age, sex, smoking status, anxiety, and the belief that oil had affected health. People living in exposed areas reported higher rates of physical and psychological symptoms than control areas. Symptoms significantly associated with exposure after adjustment for anxiety and health beliefs were those expected from the known toxicological effect of oil, suggesting a direct health effect on the exposed population.  相似文献   
78.
79.
The validity and clinical use of a recently developed instrument to assess health care needs of patients with a physical illness, called INTERMED, is investigated. The INTERMED combines data reflecting patients' biological, psychological, and social characteristics with information on health care utilization characteristics. An example of a patient population in which such an integral assessment can contribute to the appropriateness of care, are patients with low back pain of degenerative or unknown origin. It supports the validity and the clinical usefulness of the INTERMED when clinically relevant subgroups in this heterogeneous population can be identified and described based on their INTERMED scores. The INTERMED was utilized in a group of patients (N = 108) having low back pain who vary on the chronicity of complaints, functional status, and associated disability. All patients underwent a medical examination and responded to a battery of validated questionnaires assessing biological, psychological, and social aspects of their life. In addition, the patients were assessed by the INTERMED. It was studied whether it proved to be possible to form clinically meaningful groups of patients based on their INTERMED scores; for this, a hierarchical cluster analysis was performed. In order to clinically describe them, the groups of patients were compared with the data from the questionnaires. The cluster analysis on the INTERMED scores revealed three distinguishable groups of patients. Comparison with the questionnaires assessing biological, psychological, and social aspects of disease showed that one group can be characterized as complex patients with chronic complaints and reduced capacity to work who apply for a disability compensation. The other groups differed explicitly with regard to chronicity, but also on other variables. By means of the INTERMED, clinically relevant groups of patients can be identified, which supports its use in clinical practice and its use as a method to describe case mix for scientific or health care policy purposes. In addition, the INTERMED is easy to implement in daily clinical practice and can be of help to ease the operationalization of the biopychosocial model of disease. More information on its validity in different patient populations is necessary.  相似文献   
80.
M Bharadwaj  C R Lyons  I A Wortman  B Hjelle 《Vaccine》1999,17(22):2836-2843
To examine whether genetic immunization with Sin Nombre (SN) hantavirus genes could elicit immune responses, nine fragments spanning the envelope glycoprotein genes G1 and G2, and the complete N gene were cloned into a CMV expression vector. To ensure representation of all potential epitopes, adjacent fragments of the glycoprotein genes overlapped one another by 100 nucleotides. Vectors containing the gene fragments were inoculated intramuscularly into BALB/c mice and splenocyte proliferation and western blot-detectable antibodies and neutralization titers were determined. The N gene and seven of the nine M segment-derived cDNAs tested produced significant specific lymphoproliferative responses, and many of the constructs elicited either neutralizing or western blot-detectable antibodies. These promising results encourage the development of infection models for SN virus that will be capable of detecting protective responses.  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