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   1478篇
  免费   319篇
  国内免费   37篇
耳鼻咽喉   1篇
儿科学   17篇
妇产科学   17篇
基础医学   146篇
口腔科学   4篇
临床医学   75篇
内科学   496篇
皮肤病学   38篇
神经病学   12篇
特种医学   2篇
外科学   16篇
综合类   125篇
现状与发展   3篇
预防医学   809篇
药学   62篇
中国医学   1篇
肿瘤学   10篇
  2024年   7篇
  2023年   35篇
  2022年   43篇
  2021年   56篇
  2020年   87篇
  2019年   56篇
  2018年   75篇
  2017年   70篇
  2016年   54篇
  2015年   100篇
  2014年   128篇
  2013年   150篇
  2012年   141篇
  2011年   151篇
  2010年   116篇
  2009年   80篇
  2008年   72篇
  2007年   103篇
  2006年   75篇
  2005年   46篇
  2004年   33篇
  2003年   24篇
  2002年   38篇
  2001年   25篇
  2000年   27篇
  1999年   19篇
  1998年   4篇
  1997年   2篇
  1996年   8篇
  1995年   2篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
排序方式: 共有1834条查询结果,搜索用时 15 毫秒
11.
This meta-analysis examines the efficacy of international HIV prevention interventions designed to reduce sexual risk behavior of men who have sex with men (MSM). We performed a comprehensive search of published and unpublished English-language reports of HIV prevention interventions that focus on MSM and evaluated changes in risky sexual behavior or biologic outcomes related to sexual risk. Data from 33 studies described in 65 reports were available as of July 2003. Studies with insufficient data to calculate effect sizes were excluded from the meta-analysis. Interventions were associated with a significant decrease in unprotected anal intercourse (odds ratio [OR] = 0.77, 95% confidence interval [CI]: 0.65-0.92) and number of sexual partners (OR = 0.85, 95% CI: 0.61-0.94) and with a significant increase in condom use during anal intercourse (OR = 1.61, 95% CI: 1.16-2.22). Interventions successful in reducing risky sexual behavior were based on theoretic models, included interpersonal skills training, incorporated several delivery methods, and were delivered over multiple sessions spanning a minimum of 3 weeks. Behavioral interventions provide an efficacious means of HIV prevention for MSM. To the extent that proven HIV prevention interventions for MSM can be successfully replicated in community settings and adapted and tailored to different situations, the effectiveness of current HIV prevention efforts can be increased.  相似文献   
12.
目的 分析重庆地域社会文化因素对男男性接触人群(men who have sex with men, MSM)性取向认同和性角色的影响,进而探讨性角色与MSM人群HIV高感染风险的关联。 方法 在2020年采用定性访谈的方法,依托当地从事MSM干预的社会组织招募符合要求的30名MSM人群进行个人深入访谈。 结果 访谈发现,重庆MSM人群对其性取向有较好自我认同感,告知他人性取向时最顾虑家人感受,性角色为被插入方或兼有者相对更可能告知父母。大部分访谈对象认为重庆MSM性角色被插入方的比例较高,可能跟重庆人体型小皮肤好、女性地位高、接受多元文化等有关,也使得性角色被插入方的自我认同度增高。重庆公众对同性恋现象的包容度较强,城市的包容开放受移民文化、经济发展等因素影响,但也受一定传统文化的制约。MSM的社区亚文化,如追求性自由的享乐、道德规范较弱、新型毒品的使用使得不同性角色都面临感染HIV的高风险。 结论 重庆社会文化因素对MSM性角色的选择有一定影响,充分考虑社会文化因素无疑会有效推进艾滋病防控工作。  相似文献   
13.
网络规模迭加法是一种在社会网络理论基础上建立的间接估计人群规模的方法,由于不需要接触目标人群,在估计隐藏人群规模时得到了广泛应用。该方法也在不断发展进步中,本文从传统的网络规模迭加法及其进展及与新的调查技术结合三个方面进行综述,旨在为该方法的进一步应用提供参考。  相似文献   
14.
目的 分析2010-2019年凉山彝族自治州布拖县抗病毒治疗HIV/AIDS的死亡影响因素,为今后制定可持续的抗病毒治疗策略提供参考依据。方法 采用病例对照研究方法,收集2010-2019年布拖县接受抗病毒治疗HIV/AIDS与死亡者基本和随访信息,按病例数2倍抽样组成对照组,采用logistic回归模型分析其死亡的影响因素。结果 研究对象为抗病毒治疗的HIV/AIDS 3 355例,死亡组1 179例,对照组共2 176例。其中,30~49岁占81.34%,男性占69.09%,彝族占99.55%,已婚或同居占91.12%,初中及以下文化程度占95.77%,农民占88.41%。多因素logistic回归分析结果显示,研究对象的死亡风险因素中,年龄≥50岁是18~29岁的5.08倍(95%CI:3.05~8.48)、女性是男性的0.70倍(95%CI:0.52~0.94)、注射吸毒传播途径是异性性传播途径的1.43倍(95%CI:1.06~1.91)、治疗前CD4+T淋巴细胞计数(CD4)≥350个/μl是CD4<200个/μl的0.38倍(95%CI:0.30~0.48)、最近1次使用含洛匹那韦/利托那韦(LPV/r)抗病毒治疗方案是司他夫定(d4T)+拉米夫定(3TC)+奈韦拉平(NVP)/依非韦伦(EFV)方案的0.04倍(95%CI:0.01~0.18)、耐药是不耐药的3.40倍(95%CI:2.13~5.42),无病毒载量结果且未做耐药检测是不耐药的12.98倍(95%CI:10.28~16.40)。结论 年龄、性别、传播途径、治疗前CD4、最近1次抗病毒治疗方案、抗病毒治疗后耐药检测情况是布拖县接受抗病毒治疗HIV/AIDS的死亡影响因素。应扩大病毒载量和耐药检测覆盖面,科学更换抗病毒治疗方案,开展依从性教育和医务人员培训,降低抗病毒治疗HIV/AIDS死亡率。  相似文献   
15.
目的 了解MSM对HIV非职业暴露后预防(nPEP)的认知情况,以及使用nPEP的相关因素。方法 2019年3月15日至4月14日,采用滚雪球抽样方法,分别在北京市、深圳市和昆明市MSM社会组织招募年龄≥18岁男性、最近3个月发生过男男性行为、听说过HIV nPEP等符合条件的研究对象,通过“i卫士”收集人口学、行为学特征、nPEP基本知识及其咨询和使用情况。采用logistic回归模型对是否使用nPEP的相关因素进行分析。结果 共调查1 809人,nPEP基本知识知晓率为39.8%(720/1 809),33.4%(605/1 809)咨询过nPEP,15.0%(271/1 809)使用过nPEP。多因素logistic回归分析结果显示,研究对象使用nPEP的相关因素包括最近3个月与男性HIV感染者发生过性行为(OR=2.58,95%CI:1.64~4.07)、最近1年HIV检测次数≥2次(OR=2.47,95%CI:1.28~5.11)、nPEP基本知识知晓(OR=0.70,95%CI:0.49~0.99)、咨询过nPEP(OR=70.98,95%CI:40.51~136.83)。结论 MSM对nPEP认知不足,应加强MSM的nPEP相关宣传教育,促进MSM发生HIV暴露后尽快使用nPEP。  相似文献   
16.
目的 分析我国消除丙型肝炎(丙肝)的普通人群HCV检测策略的成本效果,明确最佳成本效果的HCV检测年龄。方法 运用TreeAge pro 2019软件构建决策树马尔科夫模型,以1年为周期,模拟10万名20~59岁各年龄组人群HCV检测和治疗结果,以全社会角度分析策略间比较的成本效果和效益。效果指标为增量成本效果比(ICER),效益指标为净货币效益(NMB),以我国2022年人均国内生产总值(85 698元)为意愿支付阈值。通过单因素敏感性分析和概率敏感性分析评估结果可靠性。结果 在20~59岁人群HCV检测有成本效果,在40~49岁年龄组进行HCV检测成本效果最佳。20~59岁年龄组人群HCV检测策略与未HCV检测策略比较,增量成本为161.24元/人,增量效用为0.003 6质量调整寿命年(QALYs)/人,ICER为45 197.26元/QALY,ICER小于意愿支付阈值,具有成本效果。各年龄组人群HCV检测策略与未HCV检测策略比较,ICER为42 055.06~53 249.43元/QALY,NMB为96.52~169.86元/人,其中40~49岁年龄组的ICER最低,NMB最高。单因素敏感性分析结果显示,贴现率、丙肝抗体(抗-HCV)检测成本、人群抗-HCV阳性率和直接抗病毒药物治疗成本对经济学评价影响较大,但改变参数取值,结论不变。概率敏感性分析结果表明模型分析结果稳定。结论 医疗机构探索动员20~59岁普通人群进行HCV检测具有较好的成本效果,以40~49岁年龄组人群的HCV检测成本效果最佳。在我国普通人群中实施HCV检测的“愿检尽检”策略,能降低人群丙肝疾病负担。  相似文献   
17.
Adherence to antiretroviral medications is essential for optimal treatment of HIV infection. We investigated nonadherence to antiretroviral medications in an inner-city population by using a confidential interview and a self-administered anonymous questionnaire. We estimated adherence on the day before and the month before the interview and asked reasons for nonadherence. Of 173 people who were taking antiretroviral medications, all participated in the confidential interview and 101 also completed the anonymous questionnaire. Results of the confidential interview and the anonymous questionnaire revealed rates of 6% and 28%, respectively, for nonadherence to any drug on the preceding day and of 11% and 39%, respectively, in the preceding month. The most common reasons for nonadherence in both methods were forgetfulness, inaccessibility of medications, and perceived or actual toxicity. On 12% of the anonymous questionnaires one reason for nonadherence was perceived or actual lack of drug efficacy: this reason was not given in any of the confidential interviews. Responses about the extent of nonadherence and the reasons for it may differ depending on the method of ascertainment. Interventions to improve adherence should focus on making medication dosages easier to remember, ensuring a continued supply of medications, and circumventing toxicities.  相似文献   
18.
OBJECTIVES: This study sought to estimate the size and direction of the human immunodeficiency virus (HIV) epidemic in US metropolitan statistical areas (MSAs) with populations greater than 500,000. METHODS: A "components model" from review of more than 350 documents, several large datasets, and information from 220 public health personnel was used. Data review focused on injection drug users, men who have sex with men, and high-risk heterosexual men and women. RESULTS: In the 96 MSAs, there are, broadly, an estimated 1.5 million injection drug users, 1.7 million gay and bisexual men, and 2.1 million at-risk heterosexuals, and, among them, an estimated 565,000 prevalent and 38,000 incident HIV infections. This implies about 700,000 prevalent and 41,000 new HIV infections yearly in the United States. Roughly half of all estimated new infections are occurring among injection drug users, most of them in northeastern cities, Miami, and San Juan. Gay and bisexual men still represent most prevalent HIV infections, although incidence--except in young and minority gay men--is much lower now than it was a decade ago. Relatively high prevalences of HIV in at-risk heterosexual persons in several cities indicate the potential for an increase in transmission among them. CONCLUSIONS: This review and synthesis outline the comparative epidemiology of HIV in major US cities and identify populations for interventions.  相似文献   
19.
Kevin M. De Cock, MD; Mary Glenn Fowler, MD, MPH; Eric Mercier, MD, MPH; Isabelle de Vincenzi, MD, PhD; Joseph Saba, MD; Elizabeth Hoff, MSc; David J. Alnwick, MSc; Martha Rogers, MD; Nathan Shaffer, MD

JAMA. 2000;283:1175-1182.

Each year, an estimated 590,000 infants acquire human immunodeficiency virus type 1 (HIV) infection from their mothers, mostly in developing countries that are unable to implement interventions now standard in the industrialized world. In resource-poor settings, the HIV pandemic has eroded hard-won gains in infant and child survival. Recent clinical trial results from international settings suggest that short-course antiretroviral regimens could significantly reduce perinatal HIV transmission worldwide if research findings could be translated into practice. This article reviews current knowledge of mother-to-child HIV transmission in developing countries, summarizes key findings from the trials, outlines future research requirements, and describes public health challenges of implementing perinatal HIV prevention interventions in resource-poor settings. Public health efforts must also emphasize primary prevention strategies to reduce incident HIV infections among adolescents and women of childbearing age. Successful implementation of available perinatal HIV interventions could substantially improve global child survival.

  相似文献   

20.
Incidence of cervical squamous intraepithelial lesions in HIV-infected women   总被引:17,自引:4,他引:13  
Ellerbrock TV  Chiasson MA  Bush TJ  Sun XW  Sawo D  Brudney K  Wright TC 《JAMA》2000,283(8):1031-1037
CONTEXT: Women infected with human immunodeficiency virus (HIV) are at increased risk for cervical squamous intraepithelial lesions (SILs), the precursors to invasive cervical cancer. However, little is known about the causes of this association. OBJECTIVES: To compare the incidence of SILs in HIV-infected vs uninfected women and to determine the role of risk factors in the pathogenesis of such lesions. DESIGN: Prospective cohort study conducted from October 1,1991, to June 30, 1996. SETTING: Urban clinics for sexually transmitted diseases, HIV infection, and methadone maintenance. PARTICIPANTS: A total of 328 HIV-infected and 325 uninfected women with no evidence of SILs by Papanicolaou test or colposcopy at study entry. MAIN OUTCOME MEASURE: Incident SILs confirmed by biopsy, compared by HIV status and risk factors. RESULTS: During about 30 months of follow-up, 67 (20%) HIV-infected and 16 (5%) uninfected women developed a SIL (incidence of 8.3 and 1.8 cases per 100 person-years in sociodemographically similar infected and uninfected women, respectively [P<.001]). Of incident SILs, 91% were low grade in HIV-infected women vs 75% in uninfected women. No invasive cervical cancers were identified. By multivariate analysis, significant risk factors for incident SILs were HIV infection (relative risk [RR], 3.2; 95% confidence interval [CI], 1.7-6.1), transient human papillomavirus (HPV) DNA detection (RR, 5.5; 95% CI, 1.4-21.9), persistent HPV DNA types other than 16 or 18 (RR, 7.6; 95% CI, 1.9-30.3), persistent HPV DNA types 16 and 18 (RR, 11.6; 95% CI, 2.7-50.7), and younger age (<37.5 years; RR, 2.1; 95% CI, 1.3-3.4). CONCLUSIONS: In our study, 1 in 5 HIV-infected women with no evidence of cervical disease developed biopsy-confirmed SILs within 3 years, highlighting the importance of cervical cancer screening programs in this population.  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