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   10790篇
  免费   847篇
  国内免费   41篇
耳鼻咽喉   80篇
儿科学   329篇
妇产科学   287篇
基础医学   1589篇
口腔科学   345篇
临床医学   1088篇
内科学   2567篇
皮肤病学   284篇
神经病学   937篇
特种医学   256篇
外国民族医学   4篇
外科学   1364篇
综合类   59篇
一般理论   4篇
预防医学   1130篇
眼科学   209篇
药学   532篇
中国医学   62篇
肿瘤学   552篇
  2023年   66篇
  2022年   125篇
  2021年   348篇
  2020年   200篇
  2019年   299篇
  2018年   395篇
  2017年   250篇
  2016年   279篇
  2015年   277篇
  2014年   370篇
  2013年   536篇
  2012年   681篇
  2011年   777篇
  2010年   430篇
  2009年   377篇
  2008年   580篇
  2007年   593篇
  2006年   623篇
  2005年   531篇
  2004年   508篇
  2003年   504篇
  2002年   430篇
  2001年   261篇
  2000年   291篇
  1999年   257篇
  1998年   95篇
  1997年   68篇
  1996年   67篇
  1995年   61篇
  1994年   50篇
  1993年   53篇
  1992年   133篇
  1991年   136篇
  1990年   123篇
  1989年   86篇
  1988年   78篇
  1987年   62篇
  1986年   73篇
  1985年   74篇
  1984年   62篇
  1983年   50篇
  1982年   34篇
  1979年   24篇
  1978年   28篇
  1976年   24篇
  1974年   24篇
  1973年   26篇
  1971年   25篇
  1970年   27篇
  1967年   25篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
A prospective study in order to determine level knowledge of the population about health, before and after the implantation of the Integral Medical Attention Programme to the Family, was carried out at the outpatient services in the "Pedro Borrás" Teaching Community Polyclinic Health Area. Of the population attending to this outpatient area, 917 individuals older than 15 years, were selected at random. These individuals were surveyed at the beginning of the study (November 1986), in order to collect data of main necessary aspects that the population must be acquainted with on health condition and health promotion, and were surveyed again after six months of the performance of the system (May 1987), and results of both surveys were compared and shown in tables with statistical data. The main programmes for health promotion before the implantation of the new system were, known, effectively, by the population in ratios ranging 0.26-0.49. After the performance of the new programme it was observed how the level of knowledge raises to 0.31-0.70, and knowledges on obesity and sedentary habits (0.69) and on prevention of accidents (0.70) becomes significative. We consider all these changes depending on a greater educational work by the physician and nurse in charge of the plan.  相似文献   
103.
While neutrophils are the main effectors of protective innate immune responses, they are also key players in inflammatory pathologies. Sickle cell disease (SCD) is a genetic blood disorder in which red blood cells (RBCs) are constantly destroyed in the circulation which generates a highly inflammatory environment that culminates in vascular occlusions. Vaso-occlusion is the hallmark of SCD and a predictor of disease severity. Neutrophils initiate and propagate SCD-related vaso-occlusion through adhesive interactions with the activated and dysfunctional endothelium, sickle RBCs, and platelets, leading to acute and chronic complications that progress to irreversible organ damage and ultimately death. The use of SCD humanized mouse models, in combination with in vivo imaging techniques, has emerged as a fundamental tool to understand the dynamics of neutrophils under complex inflammatory contexts and their contribution to vascular injury in SCD. In this review, we discuss the various mechanisms by which circulating neutrophils sense and respond to the wide range of stimuli present in the blood of SCD patients and mice. We argue that the central role of neutrophils in SCD can be rationalized to develop targets for the management of clinical complications in SCD patients.  相似文献   
104.
European Journal of Clinical Microbiology & Infectious Diseases - This study determined the carriage rates and antimicrobial resistance (AMR) genes of enterococci from...  相似文献   
105.
Torres JC 《Obesity surgery》1994,4(3):279-284
Selective proximal vagotomy and posterior truncal vagotomy have been performed in 71 consecutive gastric bypass (GBP) patients from June 1991 to December 1992. Vagotomy was used to prevent or diminish the incidence of marginal ulcer in GBP patients. Anterior and posterior highly selective proximal vagotomy with circular-instrument stapled gastrojejunostomy in patients undergoing GBP distal Roux-en-Y with jejunal interposition had no marginal ulcer complications (minimal follow-up 18 months).  相似文献   
106.
The aim of the present work was to assess the influence of dietary lipid source on fatty acid phospholipid profiles and on lipid mobilization. Forty male Wistar rats were divided into four groups and fed on high-fat diets which provided olive oil, sunflower oil, palm oil or beef tallow. All rats received the same amount of energy to avoid hyperphagia and differences in energy intake among groups. Phospholipid fatty acids were determined by GC. Lipolysis was stimulated in subcutaneous and perirenal isolated adipocytes by several lipolytic agents, and assessed by the determination of released glycerol. After 4 weeks of feeding, differences in body and adipose tissue weights were not observed. Dietary regimens caused great changes in adipose tissue phospholipid composition: rats fed on palm oil and beef tallow had higher concentrations of saturated fatty acids and animals fed on olive oil or sunflower oil had greater amounts of oleic and linoleic acids, respectively. These modifications did not lead to important changes in adipocyte lipolysis. Significant differences were only observed between palm-oil- and beef-tallow-fed groups when lipolysis was stimulated by isoproterenol in subcutaneous adipocytes. The fact that our feeding protocol did not induce differences in fat accumulation among groups avoids misinterpretations due to adiposity changes. The differences observed between both saturated-fat-fed groups, therefore, should only be attributable to dietary lipids. Despite this effect, the data from this work indicate that some diet-induced changes in adipose tissue fatty acid composition may have little effect on overall function.  相似文献   
107.
108.
109.
Torres RM  Hafen K 《Immunity》1999,11(5):527-536
The development of B cells requires the expression of an antigen receptor at distinct points during maturation. The Ig-alpha/beta heterodimer signals for these receptors, and mice harboring a truncation of the Ig-alpha intracellular domain (mb-1(delta(c)/delta(c)) have severely reduced peripheral B cell numbers. Here we report that immature mb-1(delta(c)/delta(c) B cells are activated despite lacking a critical Ig-alpha-positive signaling motif. As a consequence of abnormal activation, transitional immature IgMhighIgDlow B cells are largely absent in mb-1delta(c)/delta(c) mutants, accounting for the paucity of mature B cells. Thus, Ig-alpha cytoplasmic tail truncation yields an antigen receptor complex on immature B cells that signals constitutively. These data illustrate a role for Ig-alpha in negatively regulating antigen receptor signaling during B cell development.  相似文献   
110.
BACKGROUND: Several HLA alleles have been associated with asthma induced by nonsteroidal anti-inflammatory drugs (NSAIDs). The existence of HLA markers linked to other NSAID-induced reactions, such as cutaneous and anaphylactoid reactions, has not been established. OBJECTIVE: The purpose of our work was to study the HLA-DRB1 and HLA-DQB1 alleles in patients with cutaneous and anaphylactoid reactions caused by NSAIDs. METHODS: We have analyzed 114 HLA DRB1 and 26 HLA-DQB1 alleles in 21 patients with anaphylactoid reactions caused by NSAIDs, 47 patients who had exclusively cutaneous reactions during single-blind, placebo-controlled oral challenges with NSAIDs, and 167 tolerant control subjects (29 of whom had also had an IgE-mediated anaphylaxis to different agents). HLA-DRB1 and HLA-DQB1 alleles were typed by the polymerase chain reaction sequence-specific primers method with genomic DNA. RESULTS: The frequency of HLA-DR11 alleles was 58.8% in the anaphylactoid reaction group, compared with 15.9% in the NSAID-tolerant healthy control subjects (OR, 7:3; 95% confidence interval, 2.8-19.0; P <.02) and 6.3% in the group of the patients with a tolerance for NSAIDs and with IgE-mediated anaphylaxis (OR, 18.75; 95% confidence interval, 4.3-81.1; P <.004). No differences were observed among HLA-DR11 alleles analyzed. There were no significant HLA-DQB1 associations with NSAID-induced anaphylactoid reactions. Patients with cutaneous reactions had HLA frequencies that did not differ significantly from the tolerant control subjects. CONCLUSION: The HLA-DRB1*11 alleles showed a positive association with NSAID-induced anaphylactoid reactions.  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