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   398篇
  免费   37篇
  国内免费   2篇
耳鼻咽喉   4篇
儿科学   6篇
妇产科学   36篇
基础医学   67篇
口腔科学   5篇
临床医学   20篇
内科学   84篇
皮肤病学   11篇
神经病学   24篇
特种医学   81篇
外科学   22篇
综合类   1篇
预防医学   29篇
眼科学   13篇
药学   16篇
肿瘤学   18篇
  2021年   5篇
  2020年   3篇
  2019年   8篇
  2018年   7篇
  2017年   6篇
  2016年   4篇
  2015年   7篇
  2014年   7篇
  2013年   9篇
  2012年   13篇
  2011年   16篇
  2010年   6篇
  2009年   4篇
  2008年   16篇
  2007年   19篇
  2006年   12篇
  2005年   7篇
  2004年   19篇
  2003年   11篇
  2002年   12篇
  2001年   8篇
  2000年   13篇
  1999年   22篇
  1998年   8篇
  1997年   8篇
  1996年   7篇
  1995年   9篇
  1994年   4篇
  1993年   7篇
  1992年   11篇
  1991年   8篇
  1990年   12篇
  1989年   9篇
  1988年   3篇
  1987年   6篇
  1986年   5篇
  1985年   9篇
  1983年   9篇
  1982年   3篇
  1978年   6篇
  1977年   6篇
  1975年   6篇
  1974年   6篇
  1973年   9篇
  1972年   3篇
  1969年   5篇
  1968年   6篇
  1967年   5篇
  1966年   4篇
  1965年   5篇
排序方式: 共有437条查询结果,搜索用时 31 毫秒
1.
Cutaneous carcinoma histopathologically resembling nasopharyngeal carcinoma has been termed lymphoepithelioma-like carcinoma of the skin. We present an additional example of this rare cutaneous neoplasm that was located on the left temple of an 83-year-old woman. Serology for Epstein-Barr virus was negative, and exploration of the nasopharyngeal region disclosed no abnormalities. Histopathologically, the neoplasm consisted of a relatively well-circumscribed, dermal-hypodermal nodule composed of irregular aggregates of epithelial cells with vesicular nuclei, some of them in mitosis, and scant cytoplasm. A dense lymphocytic infiltrate was present within the neoplastic aggregates, obscuring the epithelial component, and at scanning magnification, the lesion closely resembled cutaneous lymphoma or pseudolymphoma. There was local sebaceous differentiation. Immunohistochemistry showed positivity in the epithelial component for AE1/AE3 and AEB-903 cytokeratins and negativity for 8–18 cylokeratins. The inflammatory infiltrate was positive for leukocyte common antigen, UCHL-1, L-26, Leu-22, and OPD-4 in variable proportions. Scattered cells within this inflammatory infiltrate were also positive for S-100 protein, vimentin, HAM-56, and MAC-387. In situ hybridization investigations for the presence of Epstein-Barr virus genomic DNA yielded negative results. Lymphoepithelioma-like carcinoma of the skin is a distinct cutaneous neoplasm of unknown histogenesis, although some foci of adnexal differentiation have been found in some specimens. The possibility of cutaneous metastasis from occult nasopharyngeal carcinoma should be ruled out.
Requena L, Sánchez Yus E, Jiménez E, Roo E. Lymphoepithelioma-like carcinoma of the skin: A light-microscopic and immunohistochemical study.  相似文献   
2.
3.
4.
Animal studies have indicated that technetium-99m l,l-ethylenedicysteine (99mTc-l,l-EC) may be a promising tracer agent for renal function studies. We have performed a paired study with 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) and 99mTc-l,l-EC in six male volunteers. In both cases, iodine-131-labelled o-iodohippurate was co-injected as an internal biological standard. The analog images between 0 and 30 min p.i. were of identical diagnostic value for both tracer agents. The two renograms were similar in all volunteers. The mean 1-h plasma clearance for 99mTc-MAG3 and 99 mTc-l,l-EC was significantly different, respectively 382.9 ± 17.1 ml/min per 1.73 m2 versus 460.2 ± 47.7 ml/min per 1.73 m2 (P<0.003). The urinary excretion after 30 min p.i. was 69.4% ± 5.6% of the injected dose for 99mTc-MAG3 versus 66.5% ± 2.5% for 99mTc-l,l-EC (P>0.05) and after 60 min p.i. respectively 83.1% ± 3.9% versus 79.8 % ± 4.3 % (P > 0.05). 99mTc-l,l-EC has a very low plasma protein binding (31% ± 6.8%) as compared to 99mTc-MAG3 (88% ± 5.2%) and a larger volume of distribution. Although the exact mechanism responsible for the high plasma clearance of 99mTc-l,l-EC is not yet fully known, we conclude that this new agent merits further clinical evaluation in patients to establish its value as a renal radiopharmaceutical. Correspondence to: A. Verbruggen  相似文献   
5.
Using 133Xe, a gamma camera and off-line data handling the effect of inhaled Salbutamol on regional lung function was measured in six patients with chronic obstructive lung disease and associated bronchospasm.After bronchodilation only minor changes were obtained in regional ventilation or in the arterial hypoxemia, although the overall airways obstruction improved markedly. These findings suggest that the bronchodilating agent had an effect mainly on the larger airways and almost did not influence the function of the more peripheral lung units responsible for gas exchange. Also, a slight but direct effect on the perfusion was demonstrated. The effect on the 133Xe ventilation-perfusion ratio was not correlated with that on the hypoxemia, indicating that the first is not a good representation of the latter.Supported by a grant from the Fonds voor Geneeskundig Wetenschappelijk Onderzoek  相似文献   
6.
The concept of cause between exposure to agent X and the subsequent development of disease Y is reviewed briefly in terms of how it is used in experimental and clinical medicine, statistics and epidemiology, and in law. Some of the interrelationships of the definition of cause by these disciplines are considered.
Resumen El concepto de causalidad entre la exposición a un agente X y el desarrollo posterior de una enfermedad Y es examinado brevemente desde el punto de vista de su aplicación en la medicina experimental y clínica, en la estadística y en la epidemiología, así como desde el punto de vista jurídico. Este estudio examina ciertas relaciones existentes entre las definiciones de causa tomadas desde estas diferentes disciplinas.

Resumé Le concept de causalité entre une exposition à un agent X et le développment ultérieur d'une maladie Y est examiné brièvement dans l'optique de son application en médecine expérimentale et clinique, en statistique et en épidémiologie, ainsi que du point de vue juridique. Cette étude examine certaines relations qui existent entre les définitions de cause prises en considération dans ces différentes disciplines.
  相似文献   
7.
8.
This study examined the implementation of a model of managing aggressive and harmful behaviour in an adolescent in-patient psychiatric unit. This model, Positive Behaviour Management, replaced a previous model, Control and Restraint, which was considered unsuitable. Both models included the use of physical interventions, and the research into such techniques is considered. The aims of the study were to evaluate the effects of three training courses on staff confidence in managing aggressive behaviour, knowledge about good practice and staff satisfaction with the new model. A multiple baseline design was used to examine change before, during and after the training period, and at one-year follow-up. The study found that staff confidence increased significantly following training but had returned to baseline levels by the time of follow-up. Staff knowledge significantly increased during the study periods but did not appear to be directly linked to the training courses, and was maintained at one-year follow-up. Staff reported significantly higher levels of satisfaction with the new model than with the previous model, which were maintained at follow-up. The findings of the study and the difficulties encountered are discussed in relation to similar findings elsewhere.  相似文献   
9.
We describe a single centre experience of 33 patients allografted for multiple myeloma, of which 28 received matched sibling marrow, one haploidentical family donor marrow and four matched but unrelated donor marrow. Median follow-up after transplant is 27 months, and 13 patients are currently alive. One out of four patients with an unrelated donor survives and 12 out of 28 (42.8%) with matched sibling donors. Four patients were unevaluable because of early death (相似文献   
10.
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