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   410724篇
  免费   24901篇
  国内免费   1462篇
耳鼻咽喉   2718篇
儿科学   12977篇
妇产科学   14991篇
基础医学   42064篇
口腔科学   9953篇
临床医学   47172篇
内科学   82286篇
皮肤病学   6137篇
神经病学   35817篇
特种医学   17367篇
外国民族医学   2篇
外科学   55354篇
综合类   5813篇
现状与发展   17篇
一般理论   161篇
预防医学   51744篇
眼科学   4926篇
药学   19896篇
  28篇
中国医学   1159篇
肿瘤学   26505篇
  2024年   597篇
  2023年   18877篇
  2022年   27008篇
  2021年   29295篇
  2020年   30115篇
  2019年   19668篇
  2018年   20163篇
  2017年   20904篇
  2016年   19705篇
  2015年   17939篇
  2014年   32687篇
  2013年   26902篇
  2012年   16601篇
  2011年   14899篇
  2010年   20131篇
  2009年   18660篇
  2008年   10535篇
  2007年   10254篇
  2006年   8500篇
  2005年   7006篇
  2004年   5955篇
  2003年   5800篇
  2002年   5911篇
  2001年   5473篇
  2000年   4691篇
  1999年   4943篇
  1998年   3622篇
  1997年   2952篇
  1996年   3056篇
  1995年   2572篇
  1994年   1953篇
  1993年   1546篇
  1992年   1924篇
  1991年   1792篇
  1990年   1861篇
  1989年   1485篇
  1988年   1734篇
  1987年   1309篇
  1986年   1054篇
  1985年   743篇
  1984年   942篇
  1983年   733篇
  1982年   807篇
  1981年   719篇
  1980年   592篇
  1979年   370篇
  1978年   398篇
  1977年   331篇
  1976年   268篇
  1975年   164篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
171.
172.
BackgroundIn the event of a cardiac arrest, emergency medical dispatchers (EMDs) play a critical role by providing telephone-assisted cardiopulmonary resuscitation (T-CPR) to laypersons. The aim of our investigation was to describe compliance with the T-CPR protocol, the performance of the laypersons in a simulated T-CPR situation, and the communication between laypersons and EMDs during these actions.MethodsWe conducted a retrospective observational study by analysing 20 recorded video and audio files. In a simulation, EMDs provided laypersons with instructions following T-CPR protocols. These were then analysed using a mixed method with convergent parallel design.ResultsIf the EMDs complied with the T-CPR protocol, the laypersons performed the correct procedures in 71% of the actions. The single most challenging instruction of the T-CPR protocol, for both EMDs and laypersons, was airway control. Mean values for compression depth and frequency did not reach established guideline goals for CPR.ConclusionProper application of T-CPR protocols by EMDs resulted in better performance by laypersons in CPR. The most problematic task for EMDs as well for laypersons was airway management. The study results did not establish that the quality of communication between EMDs and laypersons performing CPR in a cardiac arrest situation led to statistically different outcomes, as measured by the quality and effectiveness of the CPR delivered.  相似文献   
173.
174.
175.
This article explores the spatio-temporal logics at work in global health. Influenced by ideas of time–space compression, the global health literature argues that the world is characterised by a convergence of disease patterns and biomedical knowledge. While not denying the influence of these temporalities and spatialities of globalisation within the global health and chronic disease field, the article argues that they sit alongside other, often-conflicting notions of time and space. To do so, it explores the spatio-temporal logics that underpin a highly influential epidemiological model of the smoking epidemic. Unlike the temporalities and spatialities of sameness described in much of the global health literature, the article shows that this model is articulated around temporalities and spatialities of difference. This is not the difference celebrated by postmoderns, but the difference of modernisation theorists built around nations, sequential stages and progress. Indeed, the model, in stark contrast to the ‘one world, one time, one health’ globalisation mantra, divides the world into nation–states and orders them along epidemiological, geographical and development lines.  相似文献   
176.
BackgroundThe Affordable Care Act (ACA) Medicaid expansion varies in availability across states.PurposeWe compared characteristics of low-income uninsured residents in both Medicaid nonexpanding and expanding states with respect to their dietary quality, health risk factors, and access to care.MethodsData from the 2007–2012 National Health and Nutrition Examination Survey was matched with the Kaiser Family Foundation Medicaid expansion data. Bivariate and multivariate regressions were estimated to assess differences across expanding and non-expanding states.ResultThe non-expansion group had a lower Healthy Eating Index score (41.8 vs. 44.1, p-value = 0.006), a higher Body Mass Index (29.9 vs. 28.9, p-value = 0.032), higher obesity prevalence (41% vs. 33%, p-value = 0.007), and lower asthma prevalence (14.8% vs. 19.7%, p-value = 0.037) compared with the expansion group.ConclusionsDifferences across states in Medicaid coverage under the ACA may lead to widening disparities in health outcomes between expanding and non-expanding states.  相似文献   
177.
Liver-related death in human immunodeficiency virus (HIV)-infected individuals is about 10 times higher compared with the general population, and the prevalence of significant liver fibrosis in those with HIV approaches 15%. The present study aimed to assess risk factors for development of hepatic fibrosis in HIV patients receiving a modern combination anti-retroviral therapy (cART).This cross-sectional prospective study included 432 HIV patients, of which 68 (16%) patients were anti-hepatitis C virus (HCV) positive and 23 (5%) were HBsAg positive.Health trajectory including clinical characteristics and liver fibrosis stage assessed by transient elastography were collected at inclusion. Liver stiffness values >7.1 kPa were considered as significant fibrosis, while values >12.5 kPa were defined as severe fibrosis. Logistic regression and Cox regression uni- and multivariate analyses were performed to identify independent factors associated with liver fibrosis.Significant liver fibrosis was detected in 10% of HIV mono-infected, in 37% of HCV co-infected patients, and in 18% of hepatitis B virus co-infected patients. The presence of diabetes mellitus (odds ratio [OR] = 4.6) and FIB4 score (OR = 2.4) were independently associated with presence of significant fibrosis in the whole cohort. Similarly, diabetes mellitus (OR = 5.4), adiposity (OR = 4.6), and the FIB4 score (OR = 3.3) were independently associated with significant fibrosis in HIV mono-infected patients. Importantly, cumulative cART duration protected, whereas persistent HIV viral replication promoted the development of significant liver fibrosis along the duration of HIV infection.Our findings strongly indicate that besides known risk factors like metabolic disorders, HIV may also have a direct effect on fibrogenesis. Successful cART leading to complete suppression of HIV replication might protect from development of liver fibrosis.  相似文献   
178.
179.
Circulating white blood cell (WBC) and platelet (PLT) counts are widely available and inexpensive cellular biomarkers of systemic inflammation and have been associated with a risk of cardiovascular disease, cancer, and mortality. Melatonin may reduce systemic inflammation through its direct and indirect antioxidative effect; however, the associations of melatonin secretion with systemic inflammation remain unclear. In this cross‐sectional study on 1088 elderly individuals (mean age, 71.8 years), we measured overnight urinary 6‐sulfatoxymelatonin excretion (UME) and WBC and PLT counts as indices of melatonin secretion and systemic inflammation, respectively. UME was naturally log‐transformed for linear regression models because of skewed distribution (median, 6.8 μg; interquartile range, 4.1–10.6 μg). Univariate models revealed that higher log‐transformed UME levels were significantly associated with lower WBC and PLT counts (= 0.046 and 0.018). After adjusting for potential confounding factors significantly associated with WBC or PLT counts, higher log‐transformed UME levels were significantly associated with lower WBC and PLT counts (WBC: β, ?0.143; 95% confidence interval, ?0.267 to ?0.020; = 0.023; PLT: β, ?6.786; 95% confidence interval, ?12.047 to ?1.525; = 0.012). Furthermore, the adjusted mean differences in WBC and PLT counts between the lowest and highest UME tertile groups were 0.225 × 109/L and 9.480 × 109/L, respectively. In conclusion, melatonin secretion was significantly and inversely associated with WBC and PLT counts in the general elderly population. The associations were independent of several major causes of systemic inflammation, including aging, obesity, smoking, hypertension, diabetes, and physical inactivity.  相似文献   
180.
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