全文获取类型
收费全文 | 804篇 |
免费 | 41篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 40篇 |
妇产科学 | 37篇 |
基础医学 | 187篇 |
口腔科学 | 14篇 |
临床医学 | 48篇 |
内科学 | 129篇 |
皮肤病学 | 21篇 |
神经病学 | 125篇 |
特种医学 | 51篇 |
外科学 | 57篇 |
综合类 | 2篇 |
预防医学 | 75篇 |
眼科学 | 8篇 |
药学 | 27篇 |
肿瘤学 | 22篇 |
出版年
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 9篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 21篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 19篇 |
2014年 | 27篇 |
2013年 | 37篇 |
2012年 | 58篇 |
2011年 | 83篇 |
2010年 | 35篇 |
2009年 | 34篇 |
2008年 | 57篇 |
2007年 | 42篇 |
2006年 | 38篇 |
2005年 | 30篇 |
2004年 | 29篇 |
2003年 | 33篇 |
2002年 | 28篇 |
2001年 | 21篇 |
2000年 | 30篇 |
1999年 | 31篇 |
1998年 | 9篇 |
1997年 | 12篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 17篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1982年 | 3篇 |
1981年 | 1篇 |
排序方式: 共有845条查询结果,搜索用时 0 毫秒
51.
52.
Kupper N de Geus EJ van den Berg M Kirschbaum C Boomsma DI Willemsen G 《Psychoneuroendocrinology》2005,30(9):857-868
To understand the underlying genetic and environmental sources of individual variation in basal cortisol levels, we collected salivary cortisol at awakening and at six fixed time points during the day in adult twins and their singleton siblings. Reported time of awakening was verified with heart rate and body movement recordings. Cortisol data were available for 199 MZ twins, 272 DZ twins and 229 singleton siblings from 309 twin families. No differences in cortisol means and variances were found between twins and singleton siblings. Additionally, the correlations for DZ twins and siblings were not significantly different, indicating generalizability of twin study results to the general population. Genetic model fitting showed heritability for cortisol levels during the awakening period (34% for cortisol level at awakening and 32% for cortisol level at 30 min after awakening) but not for cortisol levels later during the day. The current study shows that, while cortisol levels in the awakening period are influenced by genetic factors, cortisol levels throughout most of the day are not heritable, indicating that future gene finding studies for basal cortisol should focus on the first hour post-awakening. 相似文献
53.
54.
Estimating Non-Response Bias in Family Studies: Application to Mental Health and Lifestyle 总被引:4,自引:0,他引:4
Vink JM Willemsen G Stubbe JH Middeldorp CM Ligthart RS Baas KD Dirkzwager HJ de Geus EJ Boomsma DI 《European journal of epidemiology》2004,19(7):623-630
Non-response to mailed surveys reduces the effective sample size and may introduce bias. Non-response has been studied by (1) comparison to available data in population based registers, (2) directly contacting non-respondents by telephone or single-item reply cards, and (3) longitudinal repetition of the survey. The goal of this paper was to propose an additional method to study non-response bias: when the variable of interest has a familial component, data from respondents can be used as proxy for the data from their non-responding family members. This approach was used with data on smoking, alcohol consumption, physical activity, coffee- and tea-use, education, body mass index, religion, burnout, life events, personality and mental health in large number of siblings and DZ twins registered with the Netherlands Twin Register. In addition, for smoking behavior, we also used the second strategy by sending a reply card. Results show that scores of members from less cooperative families or incomplete twin pairs tended to be more unfavorable than the scores from highly cooperative families or complete twin pairs. For example, family members from less cooperative families cycled less often and scored higher on anxious depression and neuroticism. For smoking, both the results of the reply card and the results of the additional method suggested a higher percentage smokers among the non-respondents but this was only significant with reply card method. In general, differences between highly/less cooperative families and complete/incomplete DZ twins were small. Results suggest that, even for studies with moderate response rates, data collected on health, personality and lifestyle are relatively unbiased. 相似文献
55.
56.
Evaluation of [18F]FHPG as PET tracer for HSVtk gene expression 总被引:1,自引:0,他引:1
de Vries EF van Dillen IJ van Waarde A Willemsen AT Vaalburg W Mulder NH Hospers GA 《Nuclear medicine and biology》2003,30(6):651-660
In rats, the relationship between [(18)F]FHPG accumulation and HSVtk expression was studied with PET and autoradiography. [(18)F]FHPG distribution closely corresponded with HSVtk immunohistochemical staining. ROI analysis of tracer uptake 2 hours p.i. and Patlak graphical analysis were applied to quantify the PET data. For both analysis methods, the [(18)F]FHPG PET signal correlated well with the fraction of HSVtk expressing cells implanted, but showed a plateau when plotted against HSVtk protein levels. This might be due to rate limiting [(18)F]FHPG membrane transport. 相似文献
57.
Clement AW Willemsen WL Bronkhorst EM 《Nederlands tijdschrift voor tandheelkunde》2000,107(6):230-232
Direct pulp capping is not generally accepted as a routine dental procedure. It is claimed to be an unpredictable procedure with a low success rate. However, some clinical studies do show success of direct pulp cappings. The aim of this study was to make an inventory of the success rate of direct pulp cappings performed by dental students, and of the variables which influenced the outcome. The success rate for the first 18 months after treatment was 73.8%. Only the variable 'type of tooth' showed a statistical significant correlation: front teeth showed a higher percentage of success than premolars and molars. 相似文献
58.
59.
Hombach A Schneider C Sent D Koch D Willemsen RA Diehl V Kruis W Bolhuis RL Pohl C Abken H 《International journal of cancer. Journal international du cancer》2000,88(1):115-120
Recombinant T-cell receptors with antibody-like specificity for tumor-associated antigens are successfully used to direct the cytolytic activity of T cells toward tumor cells. Clinical application, however, needs to comply with the low immunogenicity of the recombinant receptor, efficient gene transfer into peripheral blood T cells, and enrichment of receptor-grafted cells. Here, we address these issues and describe an entirely humanized immune receptor for use in adoptive immunotherapy of colorectal carcinoma. The receptor consists of a single-chain antibody (scFv) binding domain specific for carcinoembryonic antigen (CEA), the IgG hinge and CH2/CH3 (Fc) joining region, and the transmembrane and intracellular CD3 zeta signaling chain. To express the receptor in peripheral blood T cells, both GALV envelope and MuLV 4070A pseudotyped retrovirus turned out to be equally efficient, with transduction efficiencies of about 5% to 40%, depending on the lymphocyte donor. Furthermore, receptor-grafted T cells could be 2- to 6-fold enriched by magnetic activated cell sorting, utilizing an antibody directed to the extracellular IgG domain of the receptor. Upon co-culture with CEA(+) tumor cells, receptor-grafted T cells are specifically and efficiently activated to cytolysis and IFN-gamma secretion, demonstrating their feasibility for the adoptive immunotherapy of CEA(+) carcinomas. 相似文献
60.