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   1955篇
  免费   126篇
  国内免费   5篇
耳鼻咽喉   18篇
儿科学   75篇
妇产科学   76篇
基础医学   221篇
口腔科学   7篇
临床医学   290篇
内科学   334篇
皮肤病学   68篇
神经病学   195篇
特种医学   34篇
外科学   111篇
综合类   41篇
一般理论   2篇
预防医学   411篇
眼科学   25篇
药学   86篇
中国医学   2篇
肿瘤学   90篇
  2023年   12篇
  2022年   25篇
  2021年   27篇
  2020年   30篇
  2019年   48篇
  2018年   51篇
  2017年   48篇
  2016年   37篇
  2015年   52篇
  2014年   70篇
  2013年   105篇
  2012年   149篇
  2011年   141篇
  2010年   80篇
  2009年   83篇
  2008年   152篇
  2007年   124篇
  2006年   124篇
  2005年   103篇
  2004年   123篇
  2003年   129篇
  2002年   97篇
  2001年   26篇
  2000年   13篇
  1999年   20篇
  1998年   21篇
  1997年   10篇
  1996年   17篇
  1995年   15篇
  1994年   12篇
  1993年   12篇
  1992年   15篇
  1991年   8篇
  1990年   11篇
  1989年   6篇
  1988年   7篇
  1987年   6篇
  1986年   9篇
  1985年   7篇
  1984年   8篇
  1983年   7篇
  1982年   10篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1978年   3篇
  1977年   3篇
  1973年   3篇
  1971年   2篇
  1936年   2篇
排序方式: 共有2086条查询结果,搜索用时 31 毫秒
1.
2.
Goldenhar and cri-du-chat syndromes: a contiguous gene deletion syndrome?   总被引:2,自引:0,他引:2  
We report a full-term male infant born to nonconsanguinous parents who had clinical features of Goldenhar syndrome and cri du chat syndrome. At birth, the infant was noted to have dysmorphic features with bilateral preauricular tags, rotated ears, bilateral epicanthic folds, a left epibulbar lipodermoid, and an accessory left nipple. After he was assessed for feeding difficulty and tachypnea, he was found to have esophageal atresia with tracheoesophageal fistula. In addition, he had a high-pitched, cat-like cry, characteristic of cri-du-chat syndrome. He also failed a hearing test. Chromosomal analysis and fluorescence in situ hybridisation studies showed an unbalanced karyotype with a terminal deletion of the segment p14 on the short arm of chromosome 5, which is consistent with the cri-du-chat locus. The association of Goldenhar syndrome and cri-du-chat syndrome in this patient suggests that the chromosome 5p14 locus may harbor a gene implicated with Goldenhar syndrome.  相似文献   
3.
4.
5.
6.
The mapping of 5-HT2 receptors in the brain using functional imaging techniques has been limited by a relative lack of selective radioligands. Iodine-123 labelled 4-amino-N-[1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide (123I-5-I-R91150 or123I-R93274) is a new ligand for single-photon emission tomography (SPET), with high affinity and selectivity for 5-HT2A receptors. This study reports on preliminary123I-5-I-R91150 SPET, wholebody and blood distribution findings in five healthy human volunteers. Maximal brain uptake was approximately 2% of total body counts at 180 min post injection (p.i.). Dynamic SPET sequences were acquired with the brain-dedicated, single-slice multi-detector system SEM-810 over 200 min p.i. Early peak uptake (at 5 min p.i.) was seen in the cerebellum, a region free from 5HT2A receptors. In contrast, radioligand binding in the frontal cortex increased steadily over time, up to a peak at approximately 100–120 min p.i. Frontal cortex-cerebellum activity ratios reached values of 1.4, and remained stable from approximately 100 min p.i. onwards. Multi-slice SPET sequences showed a pattern of regional variation of binding compatible with the autoradiographic data on the distribution of 5-HT2A receptors in (cerebral cortex>striatum>cerebellum). These findings suggest that123I-5-I-R91150 may be used for the imaging of 5-HT2A receptors in the living human brain with SPET.  相似文献   
7.
Miriam J Alter  Wendi L Kuhnert  Lyn Finelli 《MMWR Recomm Rep》2003,52(RR-3):1-13, 15; quiz CE1-4
Testing for the presence of antibody to hepatitis C virus (anti-HCV) is recommended for initially identifying persons with hepatitis C virus (HCV) infection (CDC. Recommendations for prevention and control of hepatitis C virus [HCV] infection and HCV-related chronic disease. MMWR 1998;47[No. RR-19] :1-33). Testing for anti-HCV should include use of an antibody screening assay, and for screening test-positive results, a more specific supplemental assay. Verifying the presence of anti-HCV minimizes unnecessary medical visits and psychological harm for persons who test falsely positive by screening assays and ensures that counseling, medical referral, and evaluation are targeted for patients serologically confirmed as having been infected with HCV. However, substantial variation in reflex supplemental testing practices exists among laboratories, and an anti-HCV-positive laboratory report does not uniformly represent a confirmed positive result. These guidelines expand recommendations for anti-HCV testing to include an option for reflex supplemental testing based on screening-test-positive signal-to-cut-off (s/co) ratios. Use of s/co ratios minimizes the amount of supplemental testing that needs to be performed while improving the reliability of reported test results. These guidelines were developed on the basis of available knowledge of CDC staff in consultation with representatives from the Food and Drug Administration and public health, hospital, and independent laboratories. Adoption of these guidelines by all public and private laboratories that perform in vitro diagnostic anti-HCV testing will improve the accuracy and utility of reported anti-HCV test results for counseling and medical evaluation of patients by health-care professionals and for surveillance by public health departments.  相似文献   
8.
BACKGROUND: To adequately address the complex health needs of young people, their access to services, and the quality of services received, must be improved. AIMS: To explore the barriers to service provision for young people and to identify the training needs of primary healthcare service providers in New South Wales (NSW), Australia. DESIGN OF STUDY: A cross-sectional, qualitative study of the perspectives of a range of health service providers. SETTING: A range of primary healthcare organisations across NSW. METHODS: Samples of general practitioners (GPs), youth health workers, youth health coordinators, and community health centre staff were drawn from urban and rural clusters across NSW. Focus groups and interviews were used to identify barriers to service provision and the training needs of service providers. Data were tape recorded, transcribed, and analysed. RESULTS: Barriers to service provision among GPs and community health centre staff included inadequate time, flexibility, skills, and confidence in working with young people, and poor linkages with other relevant services. Training needs included better knowledge of and skills in adolescent health requirements, working with adolescents, and working with other services. Barriers to service provision for youth health workers and coordinators included lack of financial resources and infrastructure. There were few linkages between groups of service providers. CONCLUSION: Models of service provision that allow stronger linkages between service providers, sufficient time for consultation with young people, adequate training and support of health professionals, and flexibility of service provision, including outreach, should be explored and evaluated.  相似文献   
9.
10.
FIRST DIAGNOSIS OF SEVERE HANDICAP: A STUDY OF PARENTAL REACTIONS   总被引:2,自引:2,他引:0  
This paper reports the results of interviews with 190 parents of severely mentally handicapped children. Questions were asked about parents' satisfaction with the way they were first informed of the child's impairment. Most parents were informed by a doctor, and almost two-thirds were dissatisfied with the first information given. Satisfaction was associated with being told early in the child's life. There was a significant association between the time of telling and the diagnostic condition of the child: parents of children with handicap of no known pathology were more likely to be told during or after the second year of the child's life, while parents of children with Down's syndrome were most likely to be told at birth. The authors discuss ways in which parents can be helped through this difficult time and suggest procedures for breaking the news to parents in a sensitive way.  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