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   6034篇
  免费   334篇
  国内免费   37篇
耳鼻咽喉   28篇
儿科学   291篇
妇产科学   105篇
基础医学   310篇
口腔科学   118篇
临床医学   907篇
内科学   1123篇
皮肤病学   103篇
神经病学   442篇
特种医学   180篇
外科学   543篇
综合类   354篇
一般理论   1篇
预防医学   1066篇
眼科学   91篇
药学   413篇
中国医学   103篇
肿瘤学   227篇
  2024年   2篇
  2023年   225篇
  2022年   305篇
  2021年   459篇
  2020年   413篇
  2019年   496篇
  2018年   419篇
  2017年   266篇
  2016年   179篇
  2015年   185篇
  2014年   468篇
  2013年   485篇
  2012年   283篇
  2011年   343篇
  2010年   263篇
  2009年   308篇
  2008年   251篇
  2007年   233篇
  2006年   137篇
  2005年   120篇
  2004年   108篇
  2003年   71篇
  2002年   40篇
  2001年   52篇
  2000年   33篇
  1999年   36篇
  1998年   29篇
  1997年   27篇
  1996年   15篇
  1995年   14篇
  1994年   11篇
  1993年   7篇
  1992年   11篇
  1991年   4篇
  1990年   5篇
  1989年   5篇
  1988年   3篇
  1987年   5篇
  1985年   16篇
  1984年   10篇
  1983年   10篇
  1982年   13篇
  1981年   11篇
  1980年   9篇
  1979年   5篇
  1977年   2篇
  1976年   3篇
  1975年   4篇
  1974年   3篇
  1973年   1篇
排序方式: 共有6405条查询结果,搜索用时 875 毫秒
121.
Work-related stress is becoming a significant problem in Italy and it is therefore essential to advance the theory and methodology required to detect this phenomenon at work. Thus, the aim of this paper is to propose a new method for evaluating stress at work by measuring the discrepancies between employees’ perceptions of stress and their leaders’ evaluation of the stress of their subordinates. In addition, a positive impression scale was added to determine whether workers might give socially desirable responses in organizational diagnosis. Over 1,100 employees and 200 leaders within several Italian organizations were involved in this study. Structural equation modeling was used to test such new method for evaluating stress in a model of stress at work that incorporates relationships among individual (positive impression), interpersonal (workplace bullying) and organizational factors (working conditions, welfare culture, training). Results showed that the leaders’ capacity to understand subordinates’ stress is associated with subordinates’ psychological well-being since higher disagreement between self and leaders’ ratings was related to lower well-being. We discuss the implications of healthy leadership for the development of healthy organizations.  相似文献   
122.
The mesopancreas does not have well-defined boundaries but is continuous and connected through its components with the paraaortic area. The mesopancreatic resection margin has been indicated as the primary site for R1 resection after PD in pancreatic head cancer and total mesopancreas excision has been proposed to achieve adequate retropancreatic margin clearance and to minimize the likelihood of R1 resection. However, the anatomy of the mesopancreas requires extended dissection of the paraaortic area to maximize posterior clearance. The artery-first surgical approach has been developed to increase local radicality at the mesopancreatic resection margin. During PD, the artery-first approach begins with dissection of the connective tissues around the SMA. However, the concept of the mesopancreas as a boundless structure that includes circumferential tissues around the SMA, SMV, and paraaortic tissue highlights the need to shift from artery-first PD to mesopancreas-first PD to reduce the risk of R1 resection. From this perspective the “artery-first” approach, which allows for the avoidance of R2 resection risk, should be integrated into the “mesopancreas-first” approach to improve the R0 resection rate.In total mesopancreas excision and mesopancreas-first pancreaticoduodenectomies, the inclusion of the paraaortic area and circumferential area around the SMA in the resection field is necessary to control the tumour spread along the mesopancreatic resection margin rather than to control or stage the spread in the nodal basin.  相似文献   
123.
This review describes the landscape of novel modalities such as cell and gene therapies, viruses, other novel biologics, oligomers, and emerging technologies, including modern analytics. We summarize the regulatory history and recent landmark developments in some major markets and examine specific chemistry, manufacturing, and controls (CMC) challenges, including suggestions for exploration of potential science-based approaches in support of regulatory strategy development from an industry perspective. In addition, we evaluate the economic factors contributing to patient access to innovation and discuss the impact of regulation. There is a desperate need for a consistent form of regulation where global approaches to regulatory strategies can be harmonized, and specific CMC challenges can be dealt with using the appropriate science and risk-based tools. Although these tools are well described in current guidance documents, the specifics of applicability to complex novel modalities can still result in differing regulatory advice and outcomes. The future goals for efficiently regulating innovative modalities and technologies could be aided by more regulatory harmonization, regulatory education, and industry cooperation through consortia, enabling industry to supply key information to regulators in a transparent yet well-defined manner, and utilizing mutually understood risk-benefit analyses to produce drugs with appropriate safety, efficacy, and quality characteristics.  相似文献   
124.
125.
126.
AimThe purpose of this integrative review is to provide a comprehensive review of ethical considerations for host communities and nursing programs in planning, implementing and evaluating global health experiences for nursing students.BackgroundGlobal health experiences for nursing students are proliferating rapidly across university settings while at the same time decreasing the average time spent in the host country engaged with local communities. Global health experiences are an area where students can experience ethics as it is applied across varied contexts including resource limited international settings. As nursing education expands its global programming, exploring the ethical implications of designing, implementing and evaluating GHEs becomes pivotal to build respectful, sustainable relationships with global partners and best prepare nursing students for ethical professional practice in an interconnected world.DesignWe conducted an integrative review to examine ethical considerations in development of ethical global health experiences that benefit, rather than harm, host communities and participating nursing student guests.MethodsThe search included articles published in English language, peer-reviewed journals between 1998 and 2021 that discussed ethics in the context of nursing students traveling internationally for global health experiences. Eighteen articles met criteria for review.ResultsOverall, findings demonstrate relatively little research specific to ethical engagement in global health experiences. The articles in this integrative review discussed a range of ethical attributes including reciprocity or collaboration, respect, sustainability or commitment, justice and openness. Recommendations based on research and non-research articles are provided.ConclusionsEthical comportment in global health experiences requires careful planning, implementation and evaluation to assure an equitable and sustainable partnership between host community, faculty and nursing student guests.  相似文献   
127.
ObjectiveThe purposes of the present study were to explore independent and interactive associations between night sleep duration, night sleep quality and coronary heart disease (CHD) based on a rural population in China.MethodsA total of 27,935 participants (11,177 men and 16,758 women) were investigated from the Henan Rural Cohort. Information about sleep was assessed by using the Pittsburgh Sleep Quality Index (PSQI). Restricted cubic splines and logistic regression were used to estimate the relationship between night sleep duration and quality with CHD.ResultAmong the 27,935 participants, 1506 participants with CHD were identified. Compared with participants with scores lower than 3, the odds ratios (ORs) and 95% confidence intervals (95% CIs) of participants with score of 3–5, 6–8, ≥9 were respectively 1.42 (1.24–1.63), 1.99 (1.70–2.33), and 2.56 (2.13–3.08) with full adjustment of covariates. Compared with night sleep duration of 7 h, men and women who slept less than 5 h were 1.55 (1.11–2.17), 1.12 (0.59–2.12) and 1.80 (1.20–2.68), after being adjusted ORs (95% CIs) of the total. Moreover, the ORs and 95% CIs of CHD increased with the shortening of sleep duration at PSQI score above the highlighted levels.ConclusionPoor sleep quality and short night sleep duration were all associated with CHD in Chinese rural areas. Moreover, the association was more obvious in women. In addition, the strongest prevalence of CHD was found in short sleepers with poor sleep quality.  相似文献   
128.
BackgroundDue to the high prevalence of recurrent wheezing in the pediatric population, it is important to be able to identify environmental risk factors that may affect the etiology of asthma in several regions.Objective: to identify possible risk factors associated with asthma in children (9–12 years old) in Passo Fundo, Rio Grande do Sul, Brazil.Material and MethodsA total of 1003 school-age children were selected for the cross-sectional study by applying a standardized written questionnaire from the International Study of Asthma and Allergy, and a supplementary questionnaire (ISAAC phase II) was added to address personal, family and environmental factors. Of these, 125 children were excluded because they did not accept to do the skin prick test, resulting in a sample of 878.ResultsIndependent risk factors associated with asthma were bronchiolitis before two years old [OR] = 3.11; 2.23–4.33, current rhinitis [0R] = 2.07; 1.43–3.0; sharing bedroom during the first year of life [OR] = 2.03; 1.36–3.04; atopy [OR] = 1,82; 1.26–2.50; use of paracetamol more than 12 times a year [OR] = 1.68; 1.20–2.31; use of antibiotics in the first six months of life [OR] = 1,57 1;13–2.17; maternal asthma [OR] = 1.75; 1.05–2.78, having an indoor cat during the first year of life [OR] = 1.73, 1.07–2.78; premature birth [OR] = 1.60,1.02–2.50.Conclusionour results show that genetic backgrounds, environmental factors, premature birth, use of antibiotics before six months of life, using paracetamol once per month and the presence of co-morbidities such as rhinitis are the risk factors associated with asthma in Brazilian children.  相似文献   
129.
BackgroundAn inverse association between cardiorespiratory fitness and mortality was robustly demonstrated 3 decades ago.ObjectivesThe purpose of this study was to determine whether significant advances in disease prevention, detection, and treatment since that time have modified this association.MethodsA total of 47,862 men completed baseline examinations, including a maximal treadmill test. Cohort 1 (n = 24,475) was examined during 1971 to 1991 and followed for mortality through 1992. Cohort 2 (n = 23,387) was examined during 1992 to 2013 with follow-up through 2014. Men were categorized as low fit, moderate fit, or high fit using Cooper Clinic normative data. Hazard ratios (HRs) for all-cause, cardiovascular disease, and cancer mortality were determined across fitness categories in the 2 cohorts.ResultsA significant inverse trend between fitness categories and all-cause (HR: 1.0, 0.60, and 0.53 in cohort 1 and HR: 1.0, 0.76, and 0.52 in cohort 2) and cardiovascular disease mortality (HR: 1.0, 0.55, and 0.43 in cohort 1 and HR: 1.0, 0.84, and 0.52 in cohort 2) was observed (p trend <0.001 for all). The trend across fitness categories and cancer mortality was significant for cohort 1 (HR: 1.0, 0.62, and 0.48; p < 0.001), but not for cohort 2 (HR: 1.0, 1.08, and 0.74; p = 0.19). HRs for all-cause mortality were 0.86 (95% confidence interval: 0.82 to 0.90) and 0.87 (95% confidence interval: 0.83 to 0.91) per 1-MET increment in fitness for cohorts 1 and 2, respectively (p < 0.001 for both). Similar values were seen for cardiovascular disease and cancer mortality.ConclusionsDespite significant advances in disease prevention, detection, and treatment since fitness was first shown to be associated with mortality, the inverse association between fitness and mortality remains consistent in a contemporary cohort of men.  相似文献   
130.
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