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   3832篇
  免费   305篇
  国内免费   71篇
耳鼻咽喉   12篇
儿科学   166篇
妇产科学   37篇
基础医学   560篇
口腔科学   52篇
临床医学   273篇
内科学   622篇
皮肤病学   41篇
神经病学   192篇
特种医学   75篇
外科学   105篇
综合类   242篇
现状与发展   2篇
一般理论   3篇
预防医学   1234篇
眼科学   23篇
药学   308篇
中国医学   76篇
肿瘤学   185篇
  2024年   8篇
  2023年   67篇
  2022年   112篇
  2021年   173篇
  2020年   126篇
  2019年   106篇
  2018年   104篇
  2017年   123篇
  2016年   117篇
  2015年   143篇
  2014年   239篇
  2013年   411篇
  2012年   213篇
  2011年   223篇
  2010年   203篇
  2009年   172篇
  2008年   203篇
  2007年   163篇
  2006年   154篇
  2005年   109篇
  2004年   127篇
  2003年   122篇
  2002年   87篇
  2001年   89篇
  2000年   58篇
  1999年   65篇
  1998年   58篇
  1997年   42篇
  1996年   46篇
  1995年   45篇
  1994年   30篇
  1993年   27篇
  1992年   30篇
  1991年   30篇
  1990年   24篇
  1989年   24篇
  1988年   13篇
  1987年   18篇
  1986年   11篇
  1985年   23篇
  1984年   11篇
  1983年   8篇
  1982年   11篇
  1981年   4篇
  1980年   14篇
  1979年   5篇
  1978年   2篇
  1977年   4篇
  1976年   2篇
  1975年   4篇
排序方式: 共有4208条查询结果,搜索用时 15 毫秒
1.
The effects of climate change include floods, hurricanes, heat waves, and fires; these natural disasters can result in respiratory, cardiovascular, and psychological harm in older adults, who experience the highest morbidity and mortality during heat waves. Advanced practice registered nurses (APRNs) need education on preparing, assessing, and treating older adults for climate-change disasters, especially heat waves. This article will help APRNs understand the effects of climate-change events on the vulnerable older adults and advocates for the need to integrate health effects of climate change into curricula, practicums, policy, and research agendas.  相似文献   
2.
3.
The association between asbestos exposure, mainly in occupational settings, and malignant mesothelioma has been well established; this has prompted several countries to establish mesothelioma epidemiologic surveillance programs often at the request of national agencies. This review compares currently existing mesothelioma registries worldwide to develop a concept model for a US real-time case capture mesothelioma registry. Five countries were identified with a mesothelioma specific registry, including Italy, France, UK, Australia, and South Korea. All, except the UK, used interviews to collect exposure data. Linkage with the national death index was available or was in future plans for all registries. The registries have limited information on treatment, quality of life, and other patient-centered outcomes such as symptoms and pain management. To thoroughly collect exposure data, “real-time” enrollment is preferable; to maximize the capture of mesothelioma cases, optimal coverage, and a simplified consent process are needed.  相似文献   
4.
In this study, we estimated the disease burdens attributable to environmental tobacco smoke (ETS) exposure in Korean adults in 2010 and analyzed the trend of that from 2005 to 2010. We obtained information on the study population from the 2010 Cause of Death Statistic and estimated the ETS-attributable fraction using data from the Korean Community Health Survey and the Korean National Health and Nutrition Examination Survey. The numbers of ETS-attributable deaths in female and male non-smokers were estimated to be 4.1 and 69.6?% of the numbers of deaths attributable to current smoke, respectively. The deaths attributable to ETS were larger in female than in male non-smokers (710 vs. 420). The ETS-attributable deaths increased slightly in 2005–2008 but decreased in 2009–2010. The number of potential years of life lost from ETS was 9077.24?years in 2010. If there were no exposure to ETS in adult non-smokers, we would expect to see 1130 fewer deaths (9.9?% of the deaths from current smoke). The results suggest that ETS poses considerable disease burdens for non-smokers, especially women, in Korea.  相似文献   
5.
Although many single nucleotide polymorphism (SNP) studies have reported an association of atopy, allergic diseases and total serum immunoglobulin E (IgE) levels, almost all of these studies sought risk factors for the onset of these allergic diseases. Furthermore, many studies have analyzed a single gene and hardly any have analyzed environmental factors. In these analyses, the results could be masked and the effects of other genes and environmental factors may be decreased. Here, we described the correlation between four genes [interleukin (IL)-4 (C-590T), IL-4 receptor (A1652G), FCER1B (G6842A) and STAT6 (G2964A)] in connection with IgE production; the role of IL-10 (C-627A) as a regulatory cytokine of allergy; and the severity of food allergy (FA) and atopic eczema (AE) in 220 Japanese allergic children. In addition to these SNPs, environmental factors, i.e., patient's attitude, indoor environment, and so on, were also investigated in this study. Our study was retrospective, and the correlation was analyzed by our defined clinical scores divided into three terms: worst symptoms, recent symptoms and general amelioration at the most recent examination during the disease course. Our results indicated that IL-10 AA, the genotype with lower IL-10 production, is associated with higher IgE levels in the serum (p < 0.0001, estimate; 0.912). Marginal liver abnormalities were observed in the subject group with both FA and AE (p < 0.1191, estimate; 0.1490). Our defined clinical scores enabled evaluation of various aspects of disease severity. Based on the scores, while no single SNP selected in this study determined severity, the combination of the SNP with laboratory data and environmental factors appeared to determine severity.  相似文献   
6.
BACKGROUND: Environmental tobacco smoke (ETS) in the home continues to be a major health risk for children around the world. Measuring ETS is a central feature of clinical and epidemiological studies, with children's exposure often assessed through parental estimates. The authors examined the relationship between parent-reported estimates of children's exposure to ETS and children's urinary cotinine levels and evaluated the ETS exposure and its effect on respiratory health in children. METHODS: A total of 188 school children were included in the study. Parents were asked to complete a questionnaire about their smoking habits, their children's respiratory morbidity status and housing conditions. Urinary cotinine levels were measured in children. RESULTS: According to the responses, 72.3% of the children came from households with smokers, and 34.6% had daily exposure to ETS. When urine cotinine levels of >10 ng/mL were used as the yardstick of exposure, 76% of the children were identified as ETS exposed. No relation was detected between the symptoms of respiratory tract diseases and ETS exposure. To determine the amount of ETS exposure, the contribution of parental reports was low. CONCLUSION: To evaluate the level of ETS exposure of children, the parents' reports were not reliable. The addition of a biological measure results in a more informative estimate of ETS exposure in children.  相似文献   
7.
Respiratory infections (RI) are one of the major complaints in children and adolescents, and represent a demanding challenge for the pediatrician. It has been estimated that at least 6% of Italian children younger than 6 yr of age present recurrent respiratory infections (RRI). Children with RRI are not affected by severe alterations of the immune system. RRI represent essentially the consequence of an increased exposure to infectious agents during the first years of life, when immune functions are still largely immature. Several social and environmental factors, such as day-care attendance, family size, air pollution, parental smoking, and home dampness, represent important risk factors for airway diseases and may contribute in various degrees to determine the incidence of RRI. The main problem for the pediatrician is to discriminate normal children with high RI frequency related to an augmented exposure to environmental risk factors from children affected by other underlying pathological conditions (immunological or not), predisposing to infectious diseases. When RRI diagnosis has been formulated, removal of environmental risk factors (i.e. precocious day-care attendance, smoking in the household) must first be suggested.  相似文献   
8.
The effect associated with the substitution of adenine (A) for guanidine (G) in the promoter region of the apolipoprotein AI gene (?75 bp) with plasma apo AI and high-density lipoprotein (HDL) levels was investigated in the European Atherosclerosis Research Study (EARS). This is a study of healthy offspring (cases) of fathers who had suffered premature myocardial infarction (MI) before age 55 years (n = 565) and age- and sex-matched controls (n = 1,078) from 12 European countries, divided into 5 regions based on geography and language. The frequency of the polymorphism was not significantly different among the regions and the relative frequency of the rare A allele was similar in cases and controls (0.159 vs. 0.142) combining data from all regions. Individuals with one or more A allele had significantly higher plasma apo AI levels (P < 0.05) than individuals homozygous for the G allele. This effect was consistent in all regions. The data were analyzed separately in males and females. In females, those with one or more A allele had significantly higher apo AI levels (P = 0.05) than individuals homozygous for the G allele, and this raising effect of the A allele was greater in cases than controls for both apo AI (5.23% vs. 1.56%) and HDL (4.48% vs. 1.89%). In males, the A allele was associated with higher levels of apo AI and HDL, but the effect was much smaller and the differences did not reach statistical significance. In the females, where the effect of the A allele was strongest, the effect on apo AI associated with genotype was evident in non-smokers, and individuals with one or two A alleles had 3.6% higher apo AI and 3.14% higher HDL levels than individuals homozygous for the G allele. However, in the female smokers the raising effect of the A allele was greatly reduced (0.56%). Thus genetic variation in the promoter region of the apo AI gene is associated with differences in apo AI and HDL levels in healthy individuals throughout Europe, but the effect is modulated by gender, environmental factors such as smoking, and a family history of MI.  相似文献   
9.
Systolic and diastolic blood pressures were measured on 254 monozygotic (MZ) and 260 dizygotic (DZ) male twin pairs, during middle age (average age 48 years) and at two later age points. Genetic and environmental components of covariation were modeled by time series. For both measures, shared environmental influences were absent and specific environmental influences were largely time-specific. Although heritability was about 0.5 at each time point, genetic variation present at middle age contributed only about 60% to that present 9 years later, the remaining 40% being new. Fifteen years later, at the third time point, no new genetic variation was evident, variation in individual differences being entirely attributable to genetic differences laid down at the two earlier ages. © 1993 Wiley-Liss, Inc.  相似文献   
10.
党的十六大所提出的全面建设小康社会,是一个包括政治、经济、文化、环境乃至国民素质的综合概念。它特别要求国民具有健全的环境意识,良好的环境伦理道德和高尚的环境道德行为。作为担负着提高全体国民环境素质和培养中小学环境教育教师和地方环境建设服务三重使命的高师地理学科,面临着其环境教育的课程设置、教材建设和教师队伍建设等不可回避的课题,有必要进行深入探索。  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