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   3379篇
  免费   240篇
  国内免费   53篇
耳鼻咽喉   12篇
儿科学   72篇
妇产科学   72篇
基础医学   358篇
口腔科学   35篇
临床医学   548篇
内科学   601篇
皮肤病学   91篇
神经病学   395篇
特种医学   75篇
外科学   367篇
综合类   97篇
一般理论   4篇
预防医学   499篇
眼科学   51篇
药学   237篇
中国医学   9篇
肿瘤学   149篇
  2023年   35篇
  2022年   20篇
  2021年   55篇
  2020年   43篇
  2019年   61篇
  2018年   75篇
  2017年   65篇
  2016年   77篇
  2015年   99篇
  2014年   125篇
  2013年   163篇
  2012年   242篇
  2011年   260篇
  2010年   155篇
  2009年   147篇
  2008年   229篇
  2007年   219篇
  2006年   223篇
  2005年   202篇
  2004年   174篇
  2003年   154篇
  2002年   145篇
  2001年   41篇
  2000年   35篇
  1999年   48篇
  1998年   50篇
  1997年   34篇
  1996年   39篇
  1995年   36篇
  1994年   23篇
  1993年   26篇
  1992年   28篇
  1991年   17篇
  1990年   13篇
  1989年   15篇
  1988年   16篇
  1987年   22篇
  1986年   25篇
  1985年   18篇
  1984年   15篇
  1983年   16篇
  1982年   18篇
  1981年   18篇
  1980年   19篇
  1979年   12篇
  1978年   10篇
  1977年   17篇
  1976年   11篇
  1973年   8篇
  1966年   7篇
排序方式: 共有3672条查询结果,搜索用时 15 毫秒
91.

Objective

To explore Appalachian women's perceptions of trust and distrust of healthcare providers and the medical care system as they relate to views about cervical cancer and screening.

Methods

Thirty-six Ohio Appalachia female residents participated in community focus groups conducted by trained facilitators. Discussion topics included factors related to cervical cancer, and the issues of trust and distrust in medical care. The tape-recorded focus groups were transcribed and analyzed to identify salient themes.

Results

Five themes emerged related to trust in healthcare. Patient-centered communication and encouragement from a healthcare provider led women to trust their physicians and the medical care system. In contrast, lack of patient-centered communication by providers and perceptions of poor quality of care led to distrust. Physician gender concordance also contributed to trust as women reported trust of female physicians and distrust of male physicians; trust in male physicians was reported to be increased by the presence of a female nurse.

Conclusions

Important factors associated with trust and distrust of providers and the medical care system may impact health-seeking behaviors among underserved women.

Practice implications

Opportunities to improve patient-centered communication around the issues of prevention and cervical cancer screening (such as providing patient-focused information about access to appropriate screening tests) could be used to improve patient care and build patients’ trust.  相似文献   
92.
The solid-phase competition ELISA (SPCE) has been evaluated in both screening and titration assay formats for detecting antibodies against foot-and-mouth disease virus (FMDV) for the six non-O serotypes A, C, SAT 1, SAT 2, SAT 3 and Asia 1. Cut-off values were determined as a percentage inhibition of 40 for the SAT serotypes and 50 for serotypes A, C and Asia 1, which gave rise to specificity values ranging from 99.41% to 99.9% for the different serotypes. The relative sensitivity between the SPCE and LPBE/virus neutralisation test was 100%/109%. Antiserum titres derived by the SPCE for samples of serotypes O, A(22) and Asia 1 were more than 11, 1 and 5 times of those determined by virus neutralisation test, respectively. This study indicated that the non-type O SPCEs have sufficient sensitivities and specificities for use as serological diagnostic tests for the qualitative and quantitative detection of antibodies against FMDV.  相似文献   
93.
In vivo, growth factors exist both as soluble and as solid-phase molecules, immobilized to cell surfaces and within the extracellular matrix. We used this rationale to develop more biologically relevant approaches to study stem cell behaviors. We engineered stem cell microenvironments using inkjet bioprinting technology to create spatially defined patterns of immobilized growth factors. Using this approach, we engineered cell fate toward the osteogenic lineage in register to printed patterns of bone morphogenetic protein (BMP) 2 contained within a population of primary muscle-derived stem cells (MDSCs) isolated from adult mice. This patterning approach was conducive to patterning the MDSCs into subpopulations of osteogenic or myogenic cells simultaneously on the same chip. When cells were cultured under myogenic conditions on BMP-2 patterns, cells on pattern differentiated toward the osteogenic lineage, whereas cells off pattern differentiated toward the myogenic lineage. Time-lapse microscopy was used to visualize the formation of multinucleated myotubes, and immunocytochemistry was used to demonstrate expression of myosin heavy chain (fast) in cells off BMP-2 pattern. This work provides proof-of-concept for engineering spatially controlled multilineage differentiation of stem cells using patterns of immobilized growth factors. This approach may be useful for understanding cell behaviors to immobilized biological patterns and could have potential applications for regenerative medicine.  相似文献   
94.
95.
IntroductionUbiquinone (UQ) is a redox active lipid that transfers electrons from complex I or II to complex III in the electron transport chain (ETC). The long-lived Caenorhabditis elegans mutant clk-1 is unable to synthesize its native ubiquinone, and accumulates high amounts of its precursor, 5-demethoxyubiquinone-9 (DMQ9). In clk-1, complexes I–III activity is inhibited while complexes II–III activity is normal. We asked whether the complexes I–III defect in clk-1 was caused by: (1) a defect in the ETC; (2) an inhibitory effect of DMQ9; or (3) a decreased amount of ubiquinone.MethodsWe extracted the endogenous quinones from wildtype (N2) and clk-1 mitochondria, replenished them with exogenous ubiquinones, and measured ETC activities.ResultsReplenishment of extracted mutant and wildtype mitochondria resulted in equal enzymatic activities for complexes I–III and II–III ETC assays. Blue native gels showed that supercomplex formation was indistinguishable between clk-1 and N2. The addition of a pentane extract from clk-1 mitochondria containing DMQ9 to wildtype mitochondria specifically inhibited complexes I–III activity. UQ in clk-1 mitochondria was oxidized compared to N2.DiscussionOur results show that no measurable intrinsic ETC defect exists in clk-1 mitochondria. The data indicate that DMQ9 specifically inhibits electron transfer from complex I to ubiquinone.  相似文献   
96.
97.
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   
98.
99.
Tetanus is uncommon in Korea due to the introduction of vaccination programs and advances in public health. A case of maternal tetanus occurred on the 9 day postpartum in a 29-yr-old woman, who had not received a 10-yr-booster of tetanus-diphtheria toxoid after receiving the primary series of tetanus-toxoid-containing vaccine. There has hitherto been no reports on maternal tetanus in Korea. This case illustrates that tetanus remains a medical problem, principally among non- and under-immunized adults. The only way to fully prevent this disease is to ensure adequate immunization in all adults.  相似文献   
100.

Background

Workplace health interventions incorporating qualitative and quantitative components (mixed methods) within a Participatory Action Research approach can increase understanding of contextual issues ensuring realistic interventions which influence health behaviour. Mixed methods research teams, however, face a variety of challenges at the methodological and expertise levels when designing actions and interventions. Addressing these challenges can improve the team’s functionality and lead to higher quality health outcomes. In this paper we reflect on the data collection, implementation and data analysis phases of a mixed methods workplace health promotion project and discuss the challenges which arose within our multidisciplinary team.

Methods

This project used mixed methods within a Participatory Action Research approach to address workers’ sun safety behaviours in 14 outdoor workplaces in Queensland, Australia, and elucidate why certain measures succeeded (or failed) at the worker and management level. The project integrated qualitative methods such as policy analysis and interviews, with a range of quantitative methods – including worker surveys, ultraviolet radiation (UVR) exposure measurement, and implementation cost analyses.

Results

The research team found the integration of qualitative and quantitative analyses within the Participatory Action Research process to be challenging and a cause of tensions. This had a negative impact on the data analysis process and reporting of results, and the complexity of qualitative analysis was not truly understood by the quantitative team. Once all researchers recognised qualitative and quantitative data would be equally beneficial to the Participatory Action Research process, methodological bias was overcome to a degree to which the team could work cooperatively.

Conclusions

Mixed methods within a Participatory Action Research approach may allow a research team to discuss, reflect and learn from each other, resulting in broadened perspectives beyond the scope of any single research methodology. However, cohesive and supportive teams take constant work and adjustment under this approach, as knowledge and understanding is gained and shared. It is important researchers are cognisant of, and learn from, potential tensions within research teams due to juxtaposed philosophies, methodologies and experiences, if the team is to function efficiently and positive outcomes are to be achieved.
  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