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   1376篇
  免费   79篇
  国内免费   4篇
耳鼻咽喉   2篇
儿科学   25篇
妇产科学   74篇
基础医学   192篇
口腔科学   26篇
临床医学   87篇
内科学   283篇
皮肤病学   9篇
神经病学   197篇
特种医学   17篇
外科学   97篇
综合类   4篇
预防医学   346篇
眼科学   4篇
药学   58篇
肿瘤学   38篇
  2023年   2篇
  2022年   12篇
  2021年   28篇
  2020年   13篇
  2019年   28篇
  2018年   21篇
  2017年   27篇
  2016年   15篇
  2015年   18篇
  2014年   47篇
  2013年   61篇
  2012年   106篇
  2011年   106篇
  2010年   59篇
  2009年   71篇
  2008年   83篇
  2007年   111篇
  2006年   102篇
  2005年   84篇
  2004年   81篇
  2003年   62篇
  2002年   67篇
  2001年   28篇
  2000年   36篇
  1999年   30篇
  1998年   8篇
  1997年   11篇
  1996年   4篇
  1995年   8篇
  1994年   3篇
  1993年   8篇
  1992年   24篇
  1991年   15篇
  1990年   11篇
  1989年   7篇
  1988年   6篇
  1987年   4篇
  1986年   2篇
  1985年   4篇
  1984年   6篇
  1983年   3篇
  1982年   4篇
  1981年   4篇
  1980年   4篇
  1979年   5篇
  1978年   3篇
  1977年   3篇
  1976年   6篇
  1975年   2篇
  1965年   1篇
排序方式: 共有1459条查询结果,搜索用时 15 毫秒
1.
2.
Only a limited number of treatments are available for use in young children with malaria. OBJECTIVES: The aim of this study was to evaluate the efficacy and tolerance of mefloquine treatment in children, especially in infants of less than 15 kg, in an endemic area of malaria (French Guiana). METHOD: This five-years (1996-2000) retrospective study included 61 children aged six months to 16 years who have been treated with mefloquine for acute P. falciparum malaria. Twenty-six of these children weighted less than 15 kg. The efficiency of the treatment was evaluated using clinical and parasitic data that had been validated according to the criteria of the World Health Organization (WHO). Tolerance was compared with the data in the medical literature. RESULTS: None of the 59 patients who were given the treatment correctly presented signs of early therapeutic failure as defined by the WHO. Apyrexia was obtained in 47.8 h on average (CI 95%: 39-57; median: 36 h). The mean time required to obtain negative parasitism was 90.8 h (CI 95%: 80-101; median: 96 h) among the 51 patients in whom this was measured. Mild side effects were observed in 27.8% of the cases affecting mainly the digestive system. No differences were observed regarding efficacy or tolerance for children who weighed less than 15 kg. CONCLUSION: Mefloquine represents an efficient treatment for acute uncomplicated P. falciparum malaria in children and is well tolerated even in infants.  相似文献   
3.
Asymmetry in brain modulation of the immune system has been previously described. In mice, paw preference has been shown to be associated with immune reactivity but the mechanisms involved in such an association are not yet known. The autonomic nervous system and the neuroendocrine system are considered as major candidates for neural influences on the immune system. In the present study, the activity of the hypothalamic-pituitary-adrenal (HPA) axis of adult female mice selected for paw preference (left-handers vs. right-handers) was assessed by measuring both adrenocorticotropic hormone (ACTH) and corticosterone plasma levels, as well as the in vitro responses of hypothalamus and adrenocortical cells to various hormone releasing stimuli. The results reported here showed no difference in the activity of the HPA axis between left- and right-handed mice, suggesting that this neuroendocrine axis is not implicated in the association between functional brain asymmetry and immune reactivity. However, our results do not exclude the possibility that the HPA axis could play a role in such an association under other circumstances, such as during development or stressful situations.  相似文献   
4.
5.
6.
The aim of this study was to estimate the incidence of morbidity and mortality due to injuries in the population over the age of 14 years in Barcelona, Spain. Injury distribution according to sex, age, external cause, place of occurrence of the injury and severity was also obtained. A one-year survey was conducted in the emergency departments of the six main hospitals in Barcelona, based on a multistage sampling. Information was collected prospectively in emergency services by specially trained non-staff interviewers. Mortality data were drawn from death certificates. The incidence rate was 74.7 injury cases per 1,000 person-years over 14 years of age, higher in males than in females. Injury rates were highest in the youngest age-group and progressively lower until people over 75 years of age. Main external causes of injury were falls, being struck or caught by objects, and traffic-related injuries. The leading specific causes of injury mortality were traffic injuries, suicides and poisonings. While the overall admission incidence was 3.34 cases per 1,000 inhabitants, the proportion of hospitalized cases was 45.0 per 1,000 injury cases admitted to emergency rooms, higher for females, for traffic injuries and in the elderly population. Ninety-six percent of injury cases had an ISS value of 8 or less, mean ISS being highest for traffic injuries and falls. Injury morbidity and mortality amongst residents of Barcelona follow sex, age and cause of injury patterns which are, overall, comparable to those observed in other industrialized countries, suggesting that similar etiologic factors might be operating in those areas. The results should enable the orientation of injury prevention policies in the urban environment targeted on the young and the elderly population.  相似文献   
7.
Hepatic steatosis is a major risk factor in ischemia-reperfusion. The present study evaluates whether preconditioning, demonstrated to be effective in normal livers, could also confer protection in the presence of steatosis and investigates the potential underlying protective mechanisms. Fatty rats had increased hepatic injury and decreased survival after 60 minutes of ischemia compared with lean rats. Fatty livers showed a degree of neutrophil accumulation and microcirculatory alterations similar to that of normal livers. However, in presence of steatosis, an increased lipid peroxidation that could be reduced with glutathione-ester pretreatment was observed after hepatic reperfusion. Ischemic preconditioning reduced hepatic injury and increased animal survival. Both in normal and fatty livers, this endogenous protective mechanism was found to control lipid peroxidation, hepatic microcirculation failure, and neutrophil accumulation, reducing the subsequent hepatic injury. These beneficial effects could be mediated by nitric oxide, because the inhibition of nitric oxide synthesis and nitric oxide donor pretreatment abolished and simulated, respectively, the benefits of preconditioning. Thus, ischemic preconditioning could be an effective surgical strategy to reduce the hepatic ischemia-reperfusion injury in normal and fatty livers under normothermic conditions, including hepatic resections, and liver transplantation.  相似文献   
8.
9.
Effects of Cannabinoids on the Immune System and Central Nervous System   总被引:1,自引:0,他引:1  
This review aims to improve understanding of the modulatory effects that cannabinoids exert on the immune system and CNS. Cannabinoids possess immunomodulatory activity, are neuroprotective in vivo and in vitro and can modify the production of inflammatory mediators, such as nitric oxide, prostanoids and cytokines, that are expressed by, and act on, the immune system and the brain. The mechanisms of cannabinoid actions are not fully understood, but appear to involve complex interactions between cannabinoid receptors and a number of signal transduction pathways. Endogenous cannabinoid ligands appear to act as local modulators of immune/inflammatory reactions. Cannabinoid-induced immunosuppression may have implications for the treatment of neurological disorders that are associated with excess immunological activity, such as multiple sclerosis and Alzheimer's disease. There is anecdotal evidence that cannabis use improves the symptoms of multiple sclerosis, and studies with animal models are beginning to provide evidence for the mechanism of such effects. The development of nonpsychotropic cannabinoid analogues and modulators of the metabolism of endogenous cannabinoid ligands may lead to novel approaches to the treatment of neurodegenerative disorders.  相似文献   
10.
We have applied single-strand conformation polymorphism (SSCP) to the analysis of exon 7 of the anticoagulant protein C (PC) gene, in 13 PC-deficient Spanish families. Abnormal patterns were visualized in three samples from type I or quantitative PC deficient proposita. A previously undescribed mutation due to a TT insertion after nucleotide 6139, between codons Gly-142 and Arg-143 was found in one family. The mutation (6139,ins TT) should result in a frameshift with a stop at codon 156, which agrees with the presence of a type I or quantitative PC deficiency in the affected members of the family. The second mutation identified was a C to T transition at nucleotide 6274, 9 base pairs into intron G. This mutation (6274,C-->T), found for the first time in a Spanish family, is identical to the previously characterized PC Sant Louis. The third mutation was a G to A transition that replaces arginine 178 with glutamine (178,R-->Q). This is the third case of 178,R-->Q mutation in 17 apparently unrelated Spanish families with type I PC deficiency. Furthermore, SSCP analysis allowed the detection of another previously described mutation in a PC-deficient Spanish family (178,R-->W).  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