全文获取类型
收费全文 | 553篇 |
免费 | 37篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 5篇 |
妇产科学 | 25篇 |
基础医学 | 91篇 |
口腔科学 | 14篇 |
临床医学 | 39篇 |
内科学 | 87篇 |
皮肤病学 | 24篇 |
神经病学 | 80篇 |
特种医学 | 26篇 |
外科学 | 59篇 |
综合类 | 2篇 |
一般理论 | 1篇 |
预防医学 | 48篇 |
眼科学 | 6篇 |
药学 | 45篇 |
中国医学 | 1篇 |
肿瘤学 | 34篇 |
出版年
2023年 | 4篇 |
2022年 | 9篇 |
2021年 | 26篇 |
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 15篇 |
2016年 | 19篇 |
2015年 | 22篇 |
2014年 | 27篇 |
2013年 | 26篇 |
2012年 | 45篇 |
2011年 | 49篇 |
2010年 | 34篇 |
2009年 | 19篇 |
2008年 | 43篇 |
2007年 | 28篇 |
2006年 | 45篇 |
2005年 | 33篇 |
2004年 | 30篇 |
2003年 | 38篇 |
2002年 | 18篇 |
2001年 | 1篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1958年 | 1篇 |
排序方式: 共有592条查询结果,搜索用时 15 毫秒
1.
Photocarcinogenesis and inhibition of intercellular adhesion molecule 1 expression in cells of DNA-repair-defective individuals
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
2.
We proposed that double exposure to stressors at work and from family are associated with increased coronary risk in women and that the same exposures are accompanied by depressive feelings. The study group comprised 292 women coronary patients (30-65 years) and 292 age-matched healthy controls. Work-stress, marital-stress, and depressive symptoms were assessed by standardized questionnaires and evaluated in both case-control and 5-year follow-up analyses. We found that double exposure to stress from work and family was accompanied by the highest risk and the worst prognosis in women's coronary disease. In women patients depressive feelings were frequent, and they were more closely related to family than to work stress. In healthy women, both stressors, but in particular their combination, lead to depressive symptoms. 相似文献
3.
Prognostic value of MMP-2, -9 and TIMP-1,-2 immunoreactive protein at the invasive front in advanced head and neck squamous cell carcinomas 总被引:10,自引:0,他引:10
Ondruschka C Buhtz P Motsch C Freigang B Schneider-Stock R Roessner A Boltze C 《Pathology, research and practice》2002,198(8):509-515
In head and neck cancer as well as in other carcinomas, tumor expansion and spread to distant sites require the secretion of destructive enzymes that degrade the extracellular matrix. A variety of proteases contribute to matrix destruction. Characteristics of the invasive tumor front may reflect tumor prognosis better than do other parts of the tumor. Therefore, it was the aim of the present study to (i) compare central and peripheral tumor zones for differences in the expression of matrix-metalloproteinases (MMP) -2 and -9 and their naturally occurring inhibitors (tissue inhibitor of matrix-metalloproteinases (TIMP) -1 and -2), (ii) examine the morphological potential of malignancy, and (iii) correlate these findings with clinicopathological parameters. The study population consisted of 106 surgical specimens of advanced head and neck squamous cell carcinomas. The invasive front was graded for malignancy, and immunohistochemical staining with MMP-2, MMP-9, TIMP-1 and TIMP-2 antibodies was performed. Both MMP-2 and MMP-9 were found to be significantly overexpressed at the tumor front. The MMP-2-positive invasive front exhibited diminished overall survival times. In multivariate analysis, MMP-2 expression retained its correlation with overall survival in addition to nodal status and total malignancy score. Expression of TIMP-2 correlated with local tumor invasion. We conclude that the expression of MMP-2 at the invasive front is a marker of poor survival and appears to be associated with early recurrence in initially lymph node-negative patients. 相似文献
4.
5.
6.
Stehr Paula Weber Winja Rossmann Constanze 《Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz》2021,64(1):37-44
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Der Anteil älterer Personen in der Bevölkerung wächst stetig. Gleichzeitig steigen im Alter die Risiken für... 相似文献
7.
8.
由于分子生物学、细胞遗传学、免疫学和生物化学等基础学科的迅速发展及其与血液病学的相互渗透,近10年来血液病研究取得了较快进展.分子血液学的迅速发展也极大地推动了白血病的分子机制研究以及临床白血病的分子诊断与治疗工作.目前,不少研究者致力于造血与白血病的分子研究,其中造血与分子调控、药物代谢酶基因多态性与急性白血病(acute leukaemia,AL)、免疫与分子靶向治疗、白血病的基因诊断与基因治疗是主要的几个研究领域. 相似文献
9.
10.
Carter RM Hofstotter C Tsuchiya N Koch C 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(3):1399-1404
Previous studies of associative learning implicate higher-level cognitive processes in some forms of classical conditioning. An ongoing debate is concerned with the extent to which attention and awareness are necessary for trace but not delay eye-blink conditioning [Clark, R. E. & Squire, L. R. (1998) Science 280, 77-81; Lovibond, P. F. & Shanks, D. (2002) J. Exp. Psychol. Anim. Behav. Processes 28, 38-42]. In trace conditioning, a short interval is interposed between the termination of the conditioned stimulus (CS) and the onset of the unconditioned stimulus (US). In delay conditioning, the CS and US overlap. We here investigate the extent to which human classical fear conditioning depends on working memory. Subjects had to carry out an n-back task, requiring tracking an item 1 or 2 back in a sequentially presented list of numbers, while simultaneously being tested for their ability to associate auditory cues with shocks under a variety of conditions (single-cue versus differential; delay versus trace; no task versus 0-, 1-, and 2-back). Differential delay conditioning proved to be more resilient than differential trace conditioning but does show a reduction due to task interference similar in slope to that found in trace conditioning. Explicit knowledge of the stimulus contingency facilitates but does not guarantee trace conditioning. Only the single-cue delay protocol shows conditioning during the more difficult working memory task. Our findings suggest that the larger the cognitive demands on the system, the less likely conditioning occurs. A postexperimental questionnaire showed a positive correlation between conditioning and awareness for differential trace conditioning extinction. 相似文献