全文获取类型
收费全文 | 442篇 |
免费 | 17篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 2篇 |
妇产科学 | 2篇 |
基础医学 | 39篇 |
口腔科学 | 2篇 |
临床医学 | 48篇 |
内科学 | 112篇 |
皮肤病学 | 8篇 |
神经病学 | 31篇 |
特种医学 | 5篇 |
外科学 | 91篇 |
综合类 | 6篇 |
预防医学 | 22篇 |
眼科学 | 17篇 |
药学 | 18篇 |
肿瘤学 | 63篇 |
出版年
2023年 | 6篇 |
2022年 | 21篇 |
2021年 | 27篇 |
2020年 | 16篇 |
2019年 | 17篇 |
2018年 | 15篇 |
2017年 | 7篇 |
2016年 | 15篇 |
2015年 | 17篇 |
2014年 | 19篇 |
2013年 | 38篇 |
2012年 | 40篇 |
2011年 | 49篇 |
2010年 | 18篇 |
2009年 | 14篇 |
2008年 | 23篇 |
2007年 | 22篇 |
2006年 | 17篇 |
2005年 | 20篇 |
2004年 | 22篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有467条查询结果,搜索用时 15 毫秒
1.
The size of a microsatellite polymorphism of the haem oxygenase 1 gene is associated with idiopathic recurrent miscarriage 总被引:3,自引:0,他引:3
Denschlag D Marculescu R Unfried G Hefler LA Exner M Hashemi A Riener EK Keck C Tempfer CB Wagner O 《Molecular human reproduction》2004,10(3):211-214
Endothelial damage, impaired microvascularization and immune maladaptation have been described as aetiological factors in recurrent miscarriages. We investigated the relationship between idiopathic recurrent miscarriage (IRM) and a (GT)(n) repeat microsatellite polymorphism of the gene encoding haem oxygenase 1 (HO-1), known to modulate immune functions such as T-helper (TH) cell function and to be associated with cardiovascular disease. We investigated 162 women with IRM and 129 healthy, post-menopausal controls. The length of the HO-1 (GT)(n) microsatellite was assessed by PCR and direct sequencing in all women. Results were correlated with clinical data. The distribution of genotypes was in Hardy-Weinberg equilibrium. The HO-1 (GT)(n) microsatellite repeat numbers ranged from 13 to 37, with (GT)(23) and (GT)(30) being the most common alleles in both groups. We compared alleles consisting of < or =27 GT repeats, termed class S (short) alleles and alleles consisting of >28 GT repeats, termed class L (long) alleles. Seventy per cent of women with IRM had an S allele either in heterozygous (L/S) or homozygous (S/S) form, compared to 56% of controls (P = 0.02; OR 0.54; 95% CI 0.32-0.90). With respect to S allele frequencies, we found no significant difference among women with IRM and controls [P = 0.3; odds ratio (OR) 1.23, 95% confidence interval (CI) 0.86-1.76]. Comparing women with primary and secondary IRM, no difference with respect to the length of the HO-1 (GT)(n) microsatellite was ascertained. In summary, this is the first report on a HO-1 (GT)(n) microsatellite polymorphism among women with IRM, demonstrating that the investigated polymorphism is associated with IRM in a relatively large Caucasian population. 相似文献
2.
Kenneth James Cameal Chin-Bailey Desmalee Holder-Nevins Camelia Thompson Kayon Donaldson-Davis Denise Eldemire-Shearer 《Health & social care in the community》2021,29(5):e79-e88
The Zarit Burden Interview has been the most popularly used tool for measuring caregiver burden and with the 60 years and over population in Jamaica and developing countries expected to increase, caregiver burden and its assessment assume increased importance. Establishing the reliability and underlying factor structure of instruments such as the ZBI is critical. This study sought to determine the reliability of the Zarit Burden Interview and to assess its underlying factor structure. The ZBI was administered to 180 caregivers of community dwelling older persons in Jamaica in a nationally representative sample across four geographic health regions in 2016. The factor structure was identified using exploratory factor analysis (EFA) with Varimax rotation. Cronbach's alpha was used to assess internal consistency/reliability of the instrument. The internal consistency/reliability of the ZBI instrument was high (Cronbach's α = 0.859) and the corrected item-total correlations ranged from 0.134 to 0.730. The ZBI mean score was found to be 16.92 ± 12.04. EFA produced a six-factor model comprised of 19 items which explained 48.97% of total variance, and was subsequently reduced to four (37.27% of total variance) via the use of parallel analysis and scrutiny of confidence intervals. The four factors identified were ‘personal strain’, ‘social relations disruption’, ‘resource strain/imbalance’ and ‘role intensity’. The ZBI-22 tool is a reliable instrument for evaluating caregiver burden among community dwelling older persons in Jamaica. A four factor model has emerged providing greater insights on the underlying constructs of the ZBI, the most widely used caregiver burden assessment tool. 相似文献
3.
D Heintel E Kroemer D Kienle I Schwarzinger A Gleiss J Schwarzmeier R Marculescu T Le C Mannhalter A Gaiger S Stilgenbauer H D?hner C Fonatsch U J?ger 《Leukemia》2004,18(4):756-762
Activation-induced cytidine deaminase (AID) is essential for somatic hypermutation of B-cells. We investigated the expression of AID mRNA by real-time polymerase chain reaction (PCR) in peripheral blood mononuclear cells of 80 patients with B-CLL. AID expression was detected in 45 of 80 patients (56%) at various levels, but was undetectable in 35 patients (44%). AID PCR positivity was associated with unmutated IGV(H) gene status (22 of 25 patients; P=0.002) and unfavourable cytogenetics (18 of 23 patients with deletion in 11q or loss of p53; P=0.040). Using a threshold level of 0.01-fold expression compared to Ramos control cells, even more significant associations were observed (P=0.001 for IGVH; P=0.002 for cytogenetics). A correlation was observed between individual AID levels and the percentage of V(H) homology (R=0.41; P=0.001). AID positivity predicted unmutated IGV(H) status with an odds ratio of 8.31 (P=0.003) and poor risk cytogenetics with an odds ratio of 3.46 (P=0.032). Significance was retained after adjustment for Binet or Rai stages. AID mRNA levels were stable over time. These data suggest a potential role of AID as a prognostic marker in B-CLL. 相似文献
4.
A comparison of the in vitro and in vivo activities of IgG and F(ab')2 fragments of a mixture of three monoclonal anti-Her-2 antibodies. 总被引:5,自引:0,他引:5
PURPOSE: We have demonstrated previously that a mixture of three anti-Her-2 monoclonal antibodies (MAbs) that bind to different epitopes on the extracellular domain of Her-2 expressed on a human breast cancer cell line has more potent antitumor activity than the individual MAbs both in vitro and in xenografted severe combined immunodeficient mice. Because the activity of Herceptin is Fc dependent, we determined whether this would also be the case when a mixture of these three anti-Her-2 MAbs was used. EXPERIMENTAL DESIGN: IgG and highly purified F(ab')(2) fragments of the anti-Her-2 MAbs and Herceptin were prepared and evaluated for their ability to induce cell death, inhibit vascular endothelial growth factor secretion, and mediate antibody-dependent cellular cytotoxicity and complement-mediated cytotoxicity in vitro. They were also compared for their abilities to induce regression of large BT474 tumors in severe combined immunodeficient mice. RESULTS: All of the F(ab')(2) fragments were >95% pure and, as expected, did not mediate antibody-dependent cellular cytotoxicity or complement-dependent cytotoxicity in vitro. The in vitro antiproliferative and proapoptotic effects of the IgGs and F(ab')(2) fragments were similar. In contrast, the IgGs had significant antitumor activity in vivo, whereas their F(ab')(2) fragments were only marginally effective even at 5-fold higher doses to offset their shorter half-lives. CONCLUSIONS: These results confirm the importance of the Fc portion of Herceptin for optimal in vivo activity and demonstrate that even a mixture of three anti-Her-2 MAbs that are highly effective at inducing cell death in vitro requires Fc-mediated effector function for optimal in vivo activity. 相似文献
5.
Costan Victor Vlad Ciocan-Pendefunda Constantin-Catalin Ciofu Mihai Liviu Boisteanu Otilia Timofte Daniel Vasile Gheorghe Liliana Bogdanici Camelia Preda Cristina 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2020,258(10):2313-2320
Graefe's Archive for Clinical and Experimental Ophthalmology - The purpose of this study is to share our experience on the use of different orbital decompression techniques, as well as the... 相似文献
6.
7.
Camelia C Minic? Conor V Dolan Maarten M D Kampert Dorret I Boomsma Jacqueline M Vink 《European journal of human genetics : EJHG》2015,23(3):388-394
Given the availability of genotype and phenotype data collected in family members, the question arises which estimator ensures the most optimal use of such data in genome-wide scans. Using simulations, we compared the Unweighted Least Squares (ULS) and Maximum Likelihood (ML) procedures. The former is implemented in Plink and uses a sandwich correction to correct the standard errors for model misspecification of ignoring the clustering. The latter is implemented by fast linear mixed procedures and models explicitly the familial resemblance. However, as it commits to a background model limited to additive genetic and unshared environmental effects, it employs a misspecified model for traits with a shared environmental component. We considered the performance of the two procedures in terms of type I and type II error rates, with correct and incorrect model specification in ML. For traits characterized by moderate to large familial resemblance, using an ML procedure with a correctly specified model for the conditional familial covariance matrix should be the strategy of choice. The potential loss in power encountered by the sandwich corrected ULS procedure does not outweigh its computational convenience. Furthermore, the ML procedure was quite robust under model misspecification in the simulated settings and appreciably more powerful than the sandwich corrected ULS procedure. However, to correct for the effects of model misspecification in ML in circumstances other than those considered here, we propose to use a sandwich correction. We show that the sandwich correction can be formulated in terms of the fast ML method. 相似文献
8.
9.