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   4262篇
  免费   285篇
  国内免费   12篇
耳鼻咽喉   22篇
儿科学   159篇
妇产科学   127篇
基础医学   580篇
口腔科学   66篇
临床医学   409篇
内科学   968篇
皮肤病学   33篇
神经病学   348篇
特种医学   171篇
外科学   710篇
综合类   44篇
预防医学   277篇
眼科学   124篇
药学   192篇
中国医学   11篇
肿瘤学   318篇
  2023年   46篇
  2022年   56篇
  2021年   151篇
  2020年   88篇
  2019年   115篇
  2018年   152篇
  2017年   103篇
  2016年   124篇
  2015年   131篇
  2014年   184篇
  2013年   223篇
  2012年   380篇
  2011年   374篇
  2010年   230篇
  2009年   174篇
  2008年   260篇
  2007年   268篇
  2006年   233篇
  2005年   225篇
  2004年   186篇
  2003年   150篇
  2002年   134篇
  2001年   44篇
  2000年   52篇
  1999年   50篇
  1998年   25篇
  1997年   18篇
  1996年   11篇
  1995年   16篇
  1994年   14篇
  1993年   9篇
  1992年   20篇
  1991年   18篇
  1990年   18篇
  1989年   26篇
  1988年   22篇
  1987年   29篇
  1986年   16篇
  1985年   15篇
  1984年   22篇
  1983年   8篇
  1979年   13篇
  1978年   6篇
  1977年   6篇
  1976年   11篇
  1975年   24篇
  1974年   7篇
  1973年   17篇
  1972年   5篇
  1969年   7篇
排序方式: 共有4559条查询结果,搜索用时 15 毫秒
11.
Besides clinical efficacy, the mechanisms of action of deep brain stimulation (DBS) are still debated. To shed light on this complex issue, we have taken the opportunity to record the response of globus pallidus internus (GPi) neurones to 100 Hz stimulations in a case of Lesch-Nyhan syndrome (LNS) where four pallidal electrodes were implanted. Three types of response were observed, 2/19 neurones were unaffected by DBS. About 7/19 neurones were inhibited during DBS stimulation and 10/19 neurones were excited during DBS stimulation. Both effects ceased when DBS was turned off. Inhibited neurones were situated lower that exited ones on the trajectory (1.25 and 4.65 mm above the center of GPi respectively). These observations suggest that locally DBS induces a reversible inhibition of neurone firing rate while at the same time distantly exciting the main afferents to and/or efferents from the GPi. Both actions would result in a strong GPi inhibition that does not preclude increased outflow from the GPi.  相似文献   
12.
A selective medium and biochemical tests were used to search for Aeromonas spp. in the stools of 536 children, more than 90% of whom had "gastroenteritis", seen at Sainte-Justine Hospital, Montreal, in June or July 1986. The organism was found in seven children, six of whom had bloody diarrhea. One of the six, a 6 1/2-year-old boy, required intravenous alimentation and later manifested ulcerative colitis; the other five recovered. The remaining child, a 14-year-old boy, had synovitis of the knee and spondylarthritis. Two of the seven carried other enteric pathogens. The authors discuss the pathogenicity of Aeromonas spp., which is not very marked in temperate climates, in human summer diarrhea and its possible role in the development of ulcerative colitis.  相似文献   
13.
BACKGROUND: Results of conservative management of epithelial ovarian cancer (EOC) remain controversial in the literature. The aim of this study was to assess the clinical outcomes and fertility following fertility-sparing surgical management of EOC in a retrospective multicentre study. METHODS: A multicentre retrospective study was performed by members of two French groups. Six inclusion criteria were defined: (i) Histological review by the same pathologist; (ii) age < or =40 years; (iii) conservative management; (iv) complete peritoneal staging; (v) delivery of a platinum-based chemotherapy in stage > or = IC; and (vi) follow-up >1 year. RESULTS: Thirty-four patients fulfilled the inclusion criteria: 30 had stage IA disease; three had stage IC and one had stage IIA. Eleven patients had recurrence: 10 patients had invasive disease and one had borderline recurrence. Among 10 patients with invasive recurrence, initial stage and grade were: stage IA G1, n = 1; stage IA G2, n = 4; stage IA G3, n = 1; and stage> or = IC, n = 4. All patients with stage > IA had recurrence. Ten pregnancies were observed in nine patients. CONCLUSION: Conservative surgery for patients with EOC could be considered in young patients with stage IA G1 disease. This procedure should not be performed in patients with FIGO stage > IA.  相似文献   
14.
Hearing impairment is the most frequent sensory defect in children, with a genetic basis in about 50% of cases. Several point mutations and deletions in mitochondrial DNA (mtDNA) have been identified in non-syndromic sensorineural hearing loss (NSSNHL). Beside the frequent A1555G mutation, a number of mutations in tRNAs have been reported recently, but their incidence remains unknown. We identified the T7511C mutation in the tRNASer(UCN) gene in two French families with isolated deafness. Maternal transmission was obvious in both. The 15 patients with hearing impairment exhibited a variable disease phenotype in terms of onset, severity, and progression. T7511C was present in all the patients screened. Homoplasmic and heteroplasmic levels were observed and did not correlate with the severity of the disease. T7511C was also present in 12 hearing offspring of the oldest deaf mothers, confirming the existence of modulatory factors. Our data suggest that this mtDNA mutation should be screened for in all cases of familial NSSNHL compatible with maternal transmission.  相似文献   
15.
16.
17.
18.
Submaximal power output in adopted and biological siblings   总被引:2,自引:0,他引:2  
Submaximal power output was determined in relative steady state on a bicycle ergometer at a heart rate of 150 beats per minute (PWC150). PWC150 was measured in 880 individuals, 9 to 26 years of age, belonging to 46 sibships of adopted sibs, 66 sibships of unrelated individuals including adoptees, 33 sibships of first-degree cousins, 225 sibships of biological sibs, 56 sibships of DZ twins and 54 sibships of MZ twins. PWC150, PWC150/kg of body weight, PWC150/kg lean body mass, PWC150/cm of height and PWC150/m2 of body surface area were submitted to analysis of variance and correlation analysis after statistical control over age and sex of subjects. Few significant resemblances were found in PWC measurements for adoptive siblings, unrelated sibs and cousins. Sibling resemblance was, however, significant for the sibships of biological sibs, and of DZ and MZ twins. Interclass correlations reached significance only in pairs of biological brothers and sisters, and in pairs of DZ and MZ twins. Estimates of total genetic effect in PWC150/kg in a population of free-living children, adolescents and young adults vary from 0.30 to 0.48. It is concluded that submaximal power output is only moderately affected by the genotype.  相似文献   
19.
Transgender (trans) women experience barriers to access to HIV care, which result in their lower engagement in HIV prevention, treatment and support relative to cisgender people living with HIV. Studies of trans women's barriers to HIV care have predominantly focused on perspectives of trans women, while barriers are most often described at provider, organisation and/or systems levels. Comparing perspectives of trans women and service providers may promote a shared vision for achieving health equity. Thus, this qualitative study utilised focus groups and semi-structured interviews conducted 2018–2019 to understand barriers and facilitators to HIV care from the perspectives of trans women (n = 26) and service providers (n = 10). Barriers endorsed by both groups included: (a) anticipated and enacted stigma and discrimination in the provision of direct care, (b) lack of provider knowledge of HIV care needs for trans women, (c) absence of trans-specific services/organisations and (d) cisnormativity in sexual healthcare. Facilitators included: (a) provision of trans-positive trauma-informed care, (b) autonomy and choice for trans women in selecting sexual health services and (c) models for trans-affirming systems change. Each theme had significant overlap, yet nuanced perspective, between trans women and service providers. Specific recommendations to improve HIV care access for trans women are discussed. These recommendations can be used by administrators and service providers alike to work collaboratively with trans women to reduce barriers and facilitators to HIV care and ultimately to achieve health equity for trans women.  相似文献   
20.
Ten years of experience with falls from a height in children   总被引:2,自引:0,他引:2  
Falls from a height are a major cause of accidental death in urban children. The medical and social data on 61 children admitted over the last decade for falls of one or more stories were reviewed. Seventy-seven percent of the children survived. Of the children who fell three stories or less, all survived (100%). Fifty percent mortality occurred between the fifth and sixth floors. Seventy-seven percent of the falls were accidental and 23% of the children jumped or were pushed. The 96% decrease in accidental falls from windows since 1979 demonstrates that the "Children Can't Fly" program in New York City has almost eliminated accidental falls from windows in our hospital population.  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