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   582篇
  免费   41篇
儿科学   18篇
妇产科学   14篇
基础医学   40篇
口腔科学   6篇
临床医学   16篇
内科学   248篇
皮肤病学   8篇
神经病学   17篇
特种医学   2篇
外科学   11篇
综合类   7篇
预防医学   187篇
眼科学   2篇
药学   28篇
中国医学   1篇
肿瘤学   18篇
  2024年   1篇
  2023年   38篇
  2022年   49篇
  2021年   58篇
  2020年   104篇
  2019年   48篇
  2018年   60篇
  2017年   48篇
  2016年   27篇
  2015年   30篇
  2014年   31篇
  2013年   16篇
  2012年   15篇
  2011年   5篇
  2010年   19篇
  2009年   17篇
  2008年   3篇
  2007年   3篇
  2006年   5篇
  2005年   4篇
  2004年   1篇
  2002年   2篇
  2001年   9篇
  2000年   2篇
  1999年   3篇
  1998年   4篇
  1997年   2篇
  1996年   3篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1991年   1篇
  1989年   2篇
  1988年   3篇
  1986年   2篇
  1984年   1篇
  1980年   2篇
  1979年   1篇
排序方式: 共有623条查询结果,搜索用时 15 毫秒
31.
32.
目的基于生态位模型预测云南省血吸虫病传播风险,识别高风险区分布,为制定监测与防控措施提供依据。方法收集2004-2015年云南省18个血吸虫病流行县以村为单位的血吸虫病疫情资料和气候、地理及社会经济等13个环境变量数据,采用BIOCLIM、DOMAIN和MaxEnt等3种生态位模型构建血吸虫病传播风险探测模型,并利用受试者工作特征曲线下面积(AUC)评价模型精度。选择最佳模型分析环境变量的重要性,并预测云南省血吸虫病传播风险分布情况。结果构建的3种生态位模型均能较好地预测云南省血吸虫病传播风险的分布,其中MaxEnt模型的预测准确度最高(AUC为0.96±0.01),其次为DOMAIN模型(AUC为0.93±0.04),再次为BIOCLIM模型(AUC为0.88±0.01),三者间差异有统计学意义(P<0.05)。采用MaxEnt模型分析结果显示,影响血吸虫病分布的最主要环境因子为年平均降水量(贡献值为1.52),其次为国内生产总值和人口密度(贡献值分别为1.06和1.03)。采用MaxEnt模型预测云南省血吸虫病传播风险分布结果显示,传播风险区占云南省面积的3.1%,主要集中在西北部地区,其中低风险区和中风险区占2.7%,高风险区面积占0.4%,主要分布在鹤庆县北部、洱源县东部、大理市中部、巍山彝族自治县东北部和弥渡县北部等地区。结论基于MaxEnt生态位模型预测血吸虫病传播风险分布是可行的。云南省血吸虫病传播风险仍存在,高风险区分布较为集中,需有针对性地开展监测和防控工作。  相似文献   
33.
目的了解西藏阿里地区细粒棘球蚴人体分离株的优势基因型及遗传变异情况,为细粒棘球绦虫的溯源及阿里地区棘球蚴病预防控制策略的制定提供支持。方法收集阿里地区某医院2017年棘球蚴病患者病灶切除样品,提取DNA,PCR扩增线粒体NADH脱氢酶1(nad1)基因,扩增产物测序后用BLAST、ClustalX 1.83和MEGA 7.0软件进行同源性和系统进化分析。下载全国细粒棘球蚴人体分离株的nad1基因,利用DnaSP6分析单倍型;利用NetWork软件制作中国细粒棘球绦虫nad1基因的单倍型网络图。结果共收集80例细粒棘球蚴病患者病灶切除样品,其中38份样品PCR扩增出约550 bp的特异性条带。测序分析结果显示,4份样品为细粒棘球绦虫G6基因型,与蒙古人来源的序列(MH300971.1)一致性为99.8%;其余34份样品均为细粒棘球绦虫G1基因型,与标准序列(AF297617.1)相比,其535位的C碱基突变为G碱基,与阿尔及利亚人来源序列(MG672293.1)的一致性为100%。MEGA 7.0软件分析38份样品的序列,结果显示,T、C、A和G碱基占比依次为44.3%~46.5%、7.7%~9.1%、19.8%~21.5%和25.7%~26.0%。我国已报道的细粒棘球绦虫nad1基因共有9个单倍型,单倍型多样性为0.47,核酸多样性为0.19。单倍型网络图显示,H4为我国细粒棘球绦虫nad1基因主要的单倍型。结论细粒棘球绦虫G1、G6基因型是西藏阿里地区的主要基因型,资料分析表明H4为我国流行的细粒棘球绦虫nad1基因的主要单倍型。  相似文献   
34.
目的考察福建北部地区斯氏并殖吸虫中间宿主螺、蟹种群及其孳生地,比较生态环境改变前后感染率,并分析其变化原因。方法 2009-2019年,以并殖吸虫病例为线索,对福建省北部南平市的建瓯市小桥镇涤上村、东峰镇桂林村、城关镇七里街村和建阳区崇雒乡上洋村、政和县东平镇西表村、岭腰乡前溪村以及三明市的三元区居阳村等11处调查点进行现场采集螺、蟹,并考察其生态环境,设框(33 mm2)检测螺分布密度,计算螺的并殖吸虫尾蚴感染率和蟹的并殖吸虫囊蚴感染率、感染度。囊蚴采用人工感染健康犬(2只)和PCR扩增内转录间隔区2 (ITS2)序列、线粒体细胞色素氧化酶1 (CO1)基因进行鉴定。考察原孳生地生态环境的变化,复查螺、蟹的感染率、感染度,分析环境变化对感染率的影响。结果 11处调查点查见唐氏拟小豆螺、建瓯拟小豆螺和小桥拟钉螺等3种螺。山涧水源小沟或渗水湿地等微型生态环境为螺的适宜孳生地,螺多栖息于沟内水线上下5 mm的潮湿环境,主要附着于沟内潮湿的陈旧落叶、枯枝,其次为石块上,泥砂中较少。唐氏拟小豆螺、建瓯拟小豆螺和小桥拟钉螺的平均分布密度分别为156/框、179~291/框和12~266/框;各调查点均有螺查出斯氏并殖吸虫尾蚴,唐氏拟小豆螺、建瓯拟小豆螺和小桥拟钉螺的感染率分别为0.22%(4/1 851)、0.38%(36/9 420)、1.10%(102/9 247)。11处调查点查见福建华溪蟹、福建博特溪蟹、角肢华南溪蟹和待定种华南溪蟹等4种溪蟹。溪蟹多栖息于水流缓慢的山涧,白天潜伏于石块下,夜间四出觅食。溪蟹的斯氏并殖吸虫囊蚴感染率为38.99%~96.77%,平均感染率为80.21%(231/288),平均感染度为19.8个囊蚴/蟹。PCR结果显示,囊蚴样品扩增出的ITS2序列约500 bp,与GenBank中斯氏并殖吸虫相似性为99%;CO1基因序列约450 bp,与GenBank中宫崎并殖吸虫相似性为100%。人工感染实验结果显示,2只感染犬解剖后分别获得6和8条成虫,经鉴定均为斯氏并殖吸虫。孳生地环境改变有山洪暴发、垦植、干旱和人为破坏等原因,孳生地环境改变后对11处19次复查中,有10次未采集到螺,有5次未采集到蟹。5个调查点孳生地环境变化为山洪暴发所致,灾后进行7次调查均未查见螺,其中3处未查见溪蟹。11处调查点孳生地环境改变后,蟹的斯氏并殖吸虫囊蚴感染率为36.11%(91/252),平均感染度为4.9个囊蚴/蟹。孳生地环境改变前后的感染率差异具统计学意义(P<0.05)。结论福建北部建瓯等地为斯氏并殖吸虫高度感染的自然疫源地。孳生地生态环境改变后螺、蟹斯氏并殖吸虫尾蚴/囊蚴感染率下降明显,其中山洪暴发和垦植等是影响螺、蟹感染率下降的主要因素。  相似文献   
35.
以中国疾病预防控制中心寄生虫病预防控制所2016年8月至2017年4月举办的3次热带病预防控制主题会议(培训班)的参会人员为调查对象,采用自填式问卷调查的方法收集信息,使用SPSS 20.0软件对数据进行统计分析。共发放问卷256份,获得有效问卷241份。从未听说过全球卫生概念者占14.5%(35/241),虽听说过但不太了解者占82.6%(199/241),熟悉者仅2.9%(7/241)。调查对象对流行病学与卫生统计学知识的熟悉程度显著高于全球卫生(P<0.01)。全球卫生基本概念的正确理解占比为42.7%(103/241),≤35岁组的正确理解占比为53.8%(56/104),>35岁组为34.3%(47/137),二者差异有统计学意义(P<0.05)。97.1%(233/240)的调查对象表示有意愿参加全球卫生培训,培训内容需求排名前3的分别为疾病防控策略和技术,实验检测、诊断和研发技术,卫生管理知识;能力提升需求排名前3的分别为全球卫生视野、疾病防控经验和调查分析能力。培训方式以现场教学为主,采用教师学员互动教学模式,多聘用国外卫生系统师资。我国热带病防控人员对全球卫生知识的了解程度不容乐观,需要加强全球卫生培训和能力建设。  相似文献   
36.
《Alzheimer's & dementia》2013,9(1):1-11.e3
ObjectiveTo acquire an understanding of the societal costs of dementia and how they affect families, health and social care services, and governments to improve the lives of people with dementia and their caregivers.MethodsThe basic design of this study was a societal, prevalence-based, gross cost-of-illness study in which costs were aggregated to World Health Organization regions and World Bank income groupings.ResultsThe total estimated worldwide costs of dementia were US$604 billion in 2010. About 70% of the costs occurred in western Europe and North America. In such high-income regions, costs of informal care and the direct costs of social care contribute similar proportions of total costs, whereas the direct medical costs were much lower. In low- and middle-income countries, informal care accounts for the majority of total costs; direct social care costs are negligible.ConclusionsWorldwide costs of dementia are enormous and distributed inequitably. There is considerable potential for cost increases in coming years as the diagnosis and treatment gap is reduced. There is also likely to be a trend in low- and middle-income countries for social care costs to shift from the informal to the formal sector, with important implications for future aggregated costs and the financing of long-term care. Only by investing now in research and the development of cost-effective approaches to early diagnosis and care can future societal costs be anticipated and managed.  相似文献   
37.
Objective There is a high burden of both diabetes (DM) and tuberculosis (TB) in China, and this study aimed to assess feasibility and results of screening patients with TB for DM within the routine healthcare setting of six health facilities. Method Agreement on how to screen, monitor and record was reached in May 2011 at a stakeholders’ meeting, and training was carried out for staff in the six facilities in July 2011. Implementation started in September 2011, and we report on 7 months of activities up to 31 March 2012. Results There were 8886 registered patients with TB. They were first asked whether they had DM. If the answer was no, they were screened with a random blood glucose (RBG) followed by fasting blood glucose (FBG) in those with RBG ≥ 6.1 mm (one facility) or with an initial FBG (five facilities). Those with FBG ≥ 7.0 mm were referred to DM clinics for diagnostic confirmation with a second FBG. Altogether, 1090 (12.4%) patients with DM were identified, of whom 863 (9.7%) had a known diagnosis of DM. Of 8023 patients who needed screening for DM, 7947 (99%) were screened. This resulted in a new diagnosis of DM in 227 patients (2.9% of screened patients), and of these, 226 were enrolled to DM care. In addition, 575 (7.8%) persons had impaired fasting glucose (FBG 6.1 to <7.0 mm ). Prevalence of DM was significantly higher in patients in health facilities serving urban populations (14.0%) than rural populations (10.6%) and higher in hospital patients (13.5%) than those attending TB clinics (8.5%). Conclusion This pilot project shows that it is feasible to screen patients with TB for DM in the routine setting, resulting in a high yield of patients with known and newly diagnosed disease. Free blood tests for glucose measurement and integration of TB and DM services may improve the diagnosis and management of dually affected patients.  相似文献   
38.
《Vaccine》2018,36(4):427-437
On May 21st, 2015, the U.S. National Institute of Allergy and Infectious Diseases (NIAID) convened a workshop on delivery devices for nucleic acid (NA) as vaccines in order to review the landscape of past and future technologies for administering NA (e.g., DNA, RNA, etc.) as antigen into target tissues of animal models and humans. Its focus was on current and future applications for preventing and treating human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) disease, among other infectious-disease priorities. Meeting participants presented the results and experience of representative clinical trials of NA vaccines using a variety of alternative delivery devices, as well as a broader group of methods studied in animal models and at bench top, to improve upon the performance and/or avoid the drawbacks of conventional needle-syringe (N–S) delivery. The subjects described and discussed included (1) delivery targeted into oral, cutaneous/intradermal, nasal, upper and lower respiratory, and intramuscular tissues; (2) devices and techniques for jet injection, solid, hollow, and dissolving microneedles, patches for topical passive diffusion or iontophoresis, electroporation, thermal microporation, nasal sprayers, aerosol upper-respiratory and pulmonary inhalation, stratum-corneum ablation by ultrasound, chemicals, and mechanical abrasion, and kinetic/ballistic delivery; (3) antigens, adjuvants, and carriers such as DNA, messenger RNA, synthesized plasmids, chemokines, wet and dry aerosols, and pollen-grain and microparticle vectors; and (4) the clinical experience and humoral, cellular, and cytokine immune responses observed for many of these target tissues, technologies, constructs, and carriers. This report summarizes the presentations and discussions from the workshop (https://web.archive.org/web/20160228112310/https://www.blsmeetings.net/NucleicAcidDeliveryDevices/), which was webcast live in its entirety and archived online (http://videocast.nih.gov/summary.asp?live=16059).  相似文献   
39.
ObjectiveIn 2010 the international HIV/AIDS community called on countries to take action to prevent HIV transmission among people who inject drugs (PWID). To set a baseline we proposed an “accountability matrix”, focusing upon six countries accounting for half of the global population of PWID: China, Malaysia, Russia, Ukraine, Vietnam and the USA. Two years on, we review progress.DesignWe searched peer-reviewed literature, conducted online searches, and contacted experts for ‘grey’ literature. We limited searches to documents published since December 2009 and used decision rules endorsed in earlier reviews.ResultsPolicy shifts are increasing coverage of key interventions for PWID in China, Malaysia, Vietnam and Ukraine. Increases in PWID receiving antiretroviral treatment (ART) and opioid substitution treatment (OST) in both Vietnam and China, and a shift in Malaysia from a punitive law enforcement approach to evidence-based treatment are promising developments. The USA and Russia have had no advances on PWID access to needle and syringe programmes (NSP), OST or ART. There have also been policy setbacks in these countries, with Russia reaffirming its stance against OST and closing down access to information on methadone, and the USA reinstituting its Congressional ban on Federal funding for NSPs.ConclusionsPrevention of HIV infection and access to HIV treatment for PWID is possible. Whether countries with concentrated epidemics among PWID will meet goals of achieving universal access and eliminating new HIV infections remains unknown. As long as law enforcement responses counter public health responses, health-seeking behaviour and health service delivery will be limited.  相似文献   
40.
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