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   198篇
  免费   9篇
  国内免费   3篇
儿科学   10篇
妇产科学   3篇
基础医学   24篇
口腔科学   36篇
临床医学   18篇
内科学   35篇
皮肤病学   3篇
神经病学   22篇
特种医学   20篇
外科学   3篇
综合类   3篇
预防医学   5篇
药学   19篇
肿瘤学   9篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2018年   1篇
  2017年   2篇
  2015年   3篇
  2014年   3篇
  2013年   5篇
  2012年   3篇
  2011年   3篇
  2010年   5篇
  2009年   7篇
  2008年   8篇
  2007年   8篇
  2006年   5篇
  2005年   6篇
  2004年   4篇
  2003年   5篇
  2002年   6篇
  2001年   5篇
  2000年   6篇
  1999年   5篇
  1998年   13篇
  1997年   14篇
  1996年   14篇
  1995年   6篇
  1994年   7篇
  1993年   6篇
  1992年   5篇
  1991年   4篇
  1990年   5篇
  1989年   8篇
  1988年   8篇
  1987年   4篇
  1986年   3篇
  1984年   2篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1980年   4篇
  1979年   2篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1966年   1篇
  1963年   1篇
排序方式: 共有210条查询结果,搜索用时 23 毫秒
71.
72.
73.
Intermediate lymphocytic lymphoma: immunophenotypic and cytogenetic findings   总被引:10,自引:0,他引:10  
Weisenburger  DD; Sanger  WG; Armitage  JO; Purtilo  DT 《Blood》1987,69(6):1617-1621
A detailed immunohistologic and cytogenetic analysis of 12 cases of intermediate lymphocytic lymphoma was performed. The characteristic immunophenotype of intermediate lymphocytic lymphoma was: surface IgM and IgD+, BA1+, B1+, BA2-, B2-, B4+, Leu 14+, Leu 1+, HLA-DR+, and common acute lymphocytic leukemia associated (CALLA) antigen negative. Clonal chromosome abnormalities were identified in ten cases, with structural or numerical abnormalities of chromosomes 11 or 12 in nine cases. Five cases had structural abnormalities involving the long arm of chromosome 11; three of these had translocations with chromosome 14 at band q32. Three cases had trisomy 12, and one case had a translocation involving the long arm of chromosome 12. The tenth case had a translocation involving the long arms of chromosomes 7 and 9. These characteristic immunophenotypic and cytogenetic findings suggest a close lineage relationship between intermediate lymphocytic lymphoma and small lymphocytic (well differentiated) lymphoma/chronic lymphocytic leukemia. Their differing clinical, cytologic, and architectural features suggest, however, that intermediate lymphocytic lymphoma should be considered a separate category of lymphocytic lymphoma in the International Working Formulation.  相似文献   
74.

Background

Availability is an important predictor of early and excessive alcohol consumption by adolescents. Many countries have implemented age limits to prevent underage purchases of alcohol. However, shop-floor compliance with these age limits appears to be problematic. This study addresses the issue of non-compliance with age limits. Which measures do vendors take to avoid underage alcohol sales, and what do they report as important reasons to comply or not with age limits for alcohol sales?

Methods

Open-ended telephone interviews were conducted with store managers selling alcohol (N = 106). Prior to the interviews, all outlets were visited by an underage mystery shopper in order to measure compliance with the legal age limits on alcohol sales. The interview results are compared against actual compliance rates.

Results

Several measures have been taken to prevent underage sales, but the compliance level is low. Furthermore, open coding resulted in 19 themes, representing both valid and invalid arguments, that vendors mentioned as relevant to their decisions of whether to comply with the law. Compliance with age limits is dependent on the knowledge of the rules and the ability and motivation to follow the rules. The ability aspect in particular seems to be problematic, but in many cases, the motivation to actively comply with the age limits is lacking.

Conclusions

To enhance compliance, it is important to raise the awareness of the importance of age limits and to connect possible violations of the regulations to negative consequences.  相似文献   
75.
Although the character of acquired immunodeficiency syndrome is changing into a chronic illness, it is estimated that by the end of this century, 80 000 children and adolescents in the United States will be orphaned by parental death caused by human immunodeficiency virus infection. Plans for these children need to be made to ensure not only a stable, consistent environment that provides love and nurturing, but also the medical and social interventions necessary to cope with the tragic loss. Pediatricians should become aware of local laws and community resources and initiate discussion early in the course of parental illness to facilitate planning for the future care and custody of the children. States need to adopt laws and regulations that provide flexible approaches to guardianship and placement of children orphaned by acquired immunodeficiency syndrome.  相似文献   
76.
The present study was designed to determine the influence of signaled shock on splenic natural killer (NK) activity and nonspecific T-lymphocyte mitogenic responsiveness. Furthermore, experiments were conducted to examine possible mechanisms mediating this suppression. The results demonstrate that a single session of signaled shock induces suppression of splenic NK activity and T-cell response to the mitogens concanavalin A (Con A) and phytohemagglutinin (PHA). However, the suppression of mitogenic responsiveness was attenuated after five daily sessions of shock, while NK activity remained suppressed. The suppression of NK function was prevented by administration of naltrexone prior to the shock session indicating mediation by opiate receptors. However, naltrexone did not prevent the shock induced suppression of mitogenic responsiveness to Con A or PHA. Diazepam was not effective in preventing the shock-induced suppression of mitogenic responses or NK activity. Collectively, these results demonstrate that mononuclear cell populations in the spleen are differentially affected by the same stressor and that the immune alterations are mediated via different pathways.  相似文献   
77.
78.
79.
Vertebral bone density in children: effect of puberty   总被引:12,自引:0,他引:12  
To determine changes in bone density during growth, trabecular vertebral density and an index of spinal cortical bone were measured with quantitative computed tomography in 101 children. The children were divided by age into three groups: prepubertal, indeterminate, and pubertal. Compared with prepubertal children, pubertal adolescents had significantly higher trabecular bone density and more compact bone in the spine (P less than .001). After controlling for puberty, vertebral bone density failed to correlate significantly with age, sex, weight, height, surface area, and body mass index. The results indicate that bone density increases markedly during puberty.  相似文献   
80.
This study was designed to evaluate the effect of glucoprivation, as induced by 2-deoxy-D-glucose (2-DG) administration, on lymphocyte mitogen reactivity in Sprague-Dawley rats. The results showed that a single injection of 2-DG decreased reactivity in both whole-blood and spleen lymphocytes, as determined by mitogenic stimulation to concanavalin A (Con A) and phytohemagglutinin (PHA). However, the suppressed reactivity for the spleen lymphocytes attenuated with repeated injections, but the whole-blood lymphocytes did not show attenuation. Mitogen assessments of lymphocytes obtained from the thymus indicated that a single injection did not induce suppressed reactivity, but repeated injections induced a pronounced suppression of responsiveness. Furthermore, mitogen assessments of mesentery lymph nodes did not show any effect of 2-DG injections. These results corroborate other findings using electric shock as the stressor, namely that different compartments of the immune system are differentially affected by a stressor.  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