全文获取类型
收费全文 | 7389篇 |
免费 | 531篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 139篇 |
妇产科学 | 88篇 |
基础医学 | 296篇 |
口腔科学 | 111篇 |
临床医学 | 543篇 |
内科学 | 921篇 |
皮肤病学 | 56篇 |
神经病学 | 218篇 |
特种医学 | 92篇 |
外科学 | 512篇 |
综合类 | 811篇 |
预防医学 | 3638篇 |
眼科学 | 36篇 |
药学 | 343篇 |
中国医学 | 24篇 |
肿瘤学 | 96篇 |
出版年
2024年 | 7篇 |
2023年 | 161篇 |
2022年 | 314篇 |
2021年 | 405篇 |
2020年 | 375篇 |
2019年 | 594篇 |
2018年 | 483篇 |
2017年 | 305篇 |
2016年 | 238篇 |
2015年 | 226篇 |
2014年 | 543篇 |
2013年 | 432篇 |
2012年 | 527篇 |
2011年 | 515篇 |
2010年 | 330篇 |
2009年 | 350篇 |
2008年 | 270篇 |
2007年 | 259篇 |
2006年 | 196篇 |
2005年 | 118篇 |
2004年 | 100篇 |
2003年 | 74篇 |
2002年 | 44篇 |
2001年 | 42篇 |
2000年 | 30篇 |
1999年 | 26篇 |
1998年 | 16篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 11篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1988年 | 3篇 |
1986年 | 5篇 |
1985年 | 49篇 |
1984年 | 108篇 |
1983年 | 66篇 |
1982年 | 74篇 |
1981年 | 68篇 |
1980年 | 64篇 |
1979年 | 84篇 |
1978年 | 56篇 |
1977年 | 59篇 |
1976年 | 79篇 |
1975年 | 56篇 |
1974年 | 61篇 |
1973年 | 48篇 |
排序方式: 共有7951条查询结果,搜索用时 11 毫秒
141.
Susie Dzakpasu Paromita Deb-Rinker Laura Arbour Elizabeth K. Darling Michael S. Kramer Shiliang Liu Wei Luo Phil A. Murphy Chantal Nelson Joel G. Ray Heather Scott Michiel VandenHof K.S. Joseph 《Journal d'obstetrique et gynecologie du Canada》2019,41(11):1589-1598.e16
ObjectiveThis study sought to quantify temporal trends and provincial and territorial variations in severe maternal morbidity (SMM) in Canada.MethodsThe study used data on all hospital deliveries in Canada (excluding Québec) from 2003 to 2016 to examine temporal trends and from 2012 to 2016 to study regional variations. SMM was identified using diagnosis and intervention codes. Contrasts among periods and regions were quantified using rate ratios (RRs) and 95% confidence intervals (CIs). Temporal changes were also assessed using chi-square tests for trend (Canadian Task Force Classification II-1).ResultsThe study population included 3 882 790 deliveries between 2003 and 2016 and 1 418 545 deliveries between 2012 and 2016. Severe hemorrhage rates increased from 44.8 in 2003 to 62.4 per 10 000 deliveries in 2012 (P for trend <0.0001) and then declined to 41.8 per 10 000 deliveries in 2016 (P for trend <0.0001). Maternal intensive care unit admission and sepsis rates decreased between 2003 and 2016, whereas rates of stroke, severe uterine rupture, hysterectomy, obstetric embolism, shock, and assisted ventilation increased. Rates of composite SMM in 2012-2016 were higher in Newfoundland and Labrador (RR 1.15; 95% CI 1.04–1.26), Nova Scotia (RR 1.11; 95% CI 1.03–1.19), New Brunswick (RR1.22; 95% CI 1.13–1.32), Manitoba (RR 1.09; 95% CI 1.03–1.15), Saskatchewan (RR 1.15; 95% CI 1.09–1.22), the Yukon (RR 1.74; 95% CI 1.35–2.25), and Nunavut (RR 1.76; 95% CI 1.46–2.11) compared with the rest of Canada, whereas rates were lower in Alberta and British Columbia.ConclusionThis surveillance report helps inform clinical practice and public health policy for improving maternal health in Canada. 相似文献
142.
高新义 《中国健康心理学杂志》2016,(10):1441-1444
目的:调查了解新疆克拉玛依区不同民族城市公职人员对精神卫生与心理保健知识的知晓情况及对精神疾病的态度差异。方法:整群抽取新疆克拉玛依区城市公职人员2046人,采用精神卫生与心理保健知识问卷(MK)、精神疾病有关态度问卷(MA)进行调查。应用SPSS 17.0软件对数据进行方差分析、独立样本t检验以及描述性统计。结果:城市公职人员对精神疾病的认识不够全面,对精神疾病仍存在一定的偏见和误解;不同民族的城市公职人员在精神卫生与心理保健知识上的得分差异具有显著统计学意义(F=23.65,P0.001);不同民族的公职人员在精神卫生态度上的得分差异显著,具有统计学意义(F=2.766,P0.01)。结论:城市公职人员对精神疾病缺乏正确认识;城市公职人员的精神卫生知晓率、对精神疾病有关态度具有民族差异。 相似文献
143.
The current outbreak of Zika virus (ZIKV) in South America is one of the most serious public health emergencies since the Ebola outbreak of West Africa [2014]. ZIKV belongs to the flaviviridae family and has two lineages (Asian and African). The virus was first discovered in Uganda [1947] and the first human infection was identified in Nigeria [1952]. The current epidemic is the third of its type after that of Yap Island, Micronesia [2007] and French Polynesia [2013]. Phylogenetic studies revealed that the current strain shares about 99.7% of nucleotides and 99.9% of amino acids with the strain of French Polynesia epidemic [2013], suggesting that it has spread across the Pacific Ocean to invade South America. Aedes Aegypti mosquito is the main vector for ZIKV and there are some reports describing possible sexual and maternal to fetal transmission. ZIKV infection is known to be self-limited. However, recent reports suggested that it can be associated with neurological manifestations as Guillan-Barrè Syndrome and microcephaly in the newborn population. Currently, vector control seems to be the most effective available preventive measure against ZIKV spread. The development of broad spectrum antivirals and ZIKV vaccines should be a priority of future research. 相似文献
144.
Saurabh RamBihariLal Shrivastava Prateek Saurabh Shrivastava Jegadeesh Ramasamy 《African health sciences》2014,14(2):487-488
Background
Unsafe abortion refers to a procedure for terminating an unintended pregnancy performed either by persons lacking the necessary skills or in an environment that does not conform to minimal medical standards, or both.Objectives
The objectives of the study are to assess the factors attributing to practice of unsafe abortion and to suggest feasible and cost-effective measures to counter the same.Methods
An extensive search of all materials related to the topic was made using library sources including Pubmed, Medline and World Health Organization. Keywords used in the search include unsafe abortion and unintended pregnancy.Results
Multiple socio-demographic determinants and barriers such as illiterate women, poor socio-economic status, poor awareness about abortion services, associated stigma, and untrained health professionals have been identified resulting in restricted utilization/access of women to safe abortion services. Consequences of unsafe abortion have been alarming, seriously questioning the quality of health care delivery system.Conclusion
Concerted and dedicated efforts of government in collaboration with the private sector, community members and non-governmental organizations are needed to ensure that women have a better access to contraceptives, abortion services, and post-abortion care that are safe, affordable, and free from stigma. 相似文献145.
Trudy M. Wassenaar 《Critical reviews in microbiology》2013,39(3):155-169
This review discusses why veterinary usage of antimicrobial agents is wrongly accused of causing a substantial part of the problem of resistant human pathogens. Without doubt, resistant organisms in animals are selected by veterinary antimicrobials. However, these are not a major human health risk either because the role of veterinary usage in selection or propagation is insignificant, or because resistant populations selected by veterinary usage do not pose a substantial risk to human health. Indeed, resistant bacterial infections in humans causing serious quantitative and qualitative health consequences are rarely food-borne and are not the same as those selected by veterinary usage of antimicrobial agents. The available evidence for veterinary selection of resistance, transmission to humans, and subsequent health consequences are reviewed for food-borne zoonotic pathogens. A risk assessment strategy is proposed to quantify potential hazards in order to decide on the most effective risk management strategy. 相似文献
146.
Adolescence has long been regarded as a transition from childhood to adulthood. More recently it is become a concern of those wishing to avoid adverse health outcomes during middle and late adulthood. Most of this effort has been focused on behavioural risk factors such as tobacco and excessive alcohol use, physical exercise habits, dietary habits, as well as sexual and injury-related behaviours. The concern is that these habits are established during adolescence, continue into adulthood, and come to constitute ongoing risk factors for adverse health outcomes during middle and late adulthood. There is good reason to criticize this approach. These behaviours are themselves shaped by adolescents’ living and working conditions and even then constitute a small proportion of the variance predicting adverse health outcomes during adulthood. More complex models of how adolescence serves as a gateway to adult health outcomes are presented. These are the socio-environmental, public policy, and political economy approaches. The argument is made that adolescence is a period during which public policy plays an especially important role in predicting future health outcomes. Yet, these public policies influence health all across the life span with adolescence providing only one of many important periods during which public policy shapes health prospects during middle and later adulthood. Ultimately one should consider a range of approaches ranging from the behavioural to the political to examine how adolescence serves as a gateway towards future adult prospects. An Adolescent Gateway Towards Adult Health Model is provided to assist in this process. 相似文献
147.
P. falciparum causes the most deadly form of malaria, resulting from the adherence of infected red blood cells to blood vessels. During the blood stage of infection, the parasite secretes a large number of proteins into the host erythrocyte. The secretion of a 20-member family of protein kinases known as FIKK kinases, after a conserved Phe-Ile-Lys-Lys sequence motif, is unique to P. falciparum. Identification of physiological substrates of these kinases may provide perspective on the importance of FIKK kinase activity to P. falciparum virulence. We demonstrate, for the first time, the heterologous expression and purification of a FIKK kinase (PfFk4.1, PFD1165w). The recombinant kinase is active against general substrates and phosphorylates itself. Having demonstrated kinase activity, we incubated recombinant Fk4.1 with parasite and human erythrocyte lysates. No parasite-derived substrates were identified. However, treatment of erythrocyte ghosts shows that the FIKK kinase Fk4.1 phosphorylates dematin, a cytoskeletal protein found at the red blood cell spectrin–actin junction. 相似文献
148.
Young June Choe Jae Jeong Yang Sue K. Park Eun Hwa Choi Hoan Jong Lee 《Journal of Korean medical science》2013,28(9):1283-1288
This study aimed to describe the differences in vaccination coverage between National Immunization Program (NIP) vaccines and non-NIP vaccines in Korea and to identify factors affecting the difference. Nationwide face-to-face interview-based questionnaire survey among randomly selected 4,374 participants aged 7-83 months was conducted. Vaccination coverage analyzed according to the birth cohorts, geographic areas, and socio-demographic characteristics. We found that NIP vaccines recorded higher primary vaccination coverage compared to non-NIP vaccines (95.9%-100% vs 30.7%-85.4%). The highest rate was Haemophilus influenzae type b (Hib) vaccine (85.4%), which was introduced in 1996, and the lowest rate was rotavirus vaccine (30.7%), which was introduced recently. On multivariate analysis, having a sibling were significantly associated with lower uptake of Hib vaccine, pneumococcal conjugate vaccine (PCV), and rotavirus vaccine; while, older mother''s age and attendance to daycare center were significantly associated with lower uptake of PCV and rotavirus vaccine (P < 0.001). We found differences in the vaccine coverage rate between NIP vaccines and non-NIP vaccines; and the data suggests potential disparity in accessing non-NIP vaccines in Korea. Expansion of NIP to include non-NIP vaccines can provide better protection against the diseases through increased coverage. 相似文献
149.
《Human immunology》2022,83(3):204-218
Antibodies against HLA antigens are ubiquitous in the sera of transplant patients. Analysis of anti-HLA antibodies specificity has gone through a long history of development using assays like agglutination and lymphocytotoxicity, which utilize lymphocytes, and flow cytometry, which utilize multiplex beads coupled with single antigens. Hundreds of HLA antigens are identified to date, and the realization that antibody reactivity against the antigens is multispecific presented difficulties in accurately defining antibody specificity. Although Cross Reacting Groups (CREG), describing cross reactivity among HLA antigens, were helpful with determining specificity, they proved to be inadequate for the highly sensitized patients. Amino acid sequencing and three-dimensional modeling of the HLA molecules significantly advanced our understating of the HLA antigens and their epitopes. Although sensitive assays for antibody testing advanced analysis, they unmasked additional specificities undetectable by traditional methods, and the presence of naturally occurring anti-HLA antibodies in sera further complicated analysis and underscored the need to understand antibody reactivity and their epitopes. Hundreds of HLA class-I and class-II epitopes were defined by the Tekasaki and Duquesnoy groups and their usefulness in organ transplants were further advanced by a great number of transplant centers. Alloantibody specificities, CREGs, and nondonor specific antigens (NDSA) are now explained by public epitopes 相似文献
150.
Human detoxification of perfluorinated compounds 总被引:1,自引:0,他引:1