全文获取类型
收费全文 | 314篇 |
免费 | 30篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 11篇 |
妇产科学 | 16篇 |
基础医学 | 55篇 |
口腔科学 | 2篇 |
临床医学 | 35篇 |
内科学 | 54篇 |
皮肤病学 | 7篇 |
神经病学 | 34篇 |
特种医学 | 10篇 |
外科学 | 43篇 |
综合类 | 1篇 |
预防医学 | 16篇 |
眼科学 | 2篇 |
药学 | 7篇 |
中国医学 | 1篇 |
肿瘤学 | 49篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 11篇 |
2021年 | 19篇 |
2020年 | 12篇 |
2019年 | 9篇 |
2018年 | 14篇 |
2017年 | 9篇 |
2016年 | 13篇 |
2015年 | 13篇 |
2014年 | 22篇 |
2013年 | 17篇 |
2012年 | 26篇 |
2011年 | 23篇 |
2010年 | 15篇 |
2009年 | 9篇 |
2008年 | 14篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 10篇 |
2004年 | 14篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1992年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
排序方式: 共有345条查询结果,搜索用时 15 毫秒
61.
62.
The Gibbon Ape Leukemia Virus envelope protein (GALV-Env) mediates efficient transduction of human cells, particularly primary B and T lymphocytes, and is therefore of great interest in gene therapy. Using internal domains from murine leukemia viruses (MLV), chimeric GALV-Env proteins such as GALV-C4070A were derived, which allow pseudotyping of lentiviral vectors. In order to improve expression efficiency and vector titers, we developed a codon-optimized (co) variant of GALV-C4070A (coGALV-Env). We found that coGALV-Env mediated efficient pseudotyping not only of γ-retroviral and lentiviral vectors, but also α-retroviral vectors. The obtained titers on HEK293T cells were equal to those with the classical GALV-Env, whereas the required plasmid amounts for transient vector production were significantly lower, namely, 20 ng coGALV-Env plasmid per 106 293T producer cells. Importantly, coGALV-Env-pseudotyped γ- and α-retroviral, as well as lentiviral vectors, mediated efficient transduction of primary human T cells. We propose that the novel chimeric coGALV-Env gene will be very useful for the efficient production of high-titer vector preparations, e.g., to equip human T cells with novel specificities using transgenic TCRs or CARs. The considerably lower amount of plasmid needed might also result in a significant cost advantage for good manufacturing practice (GMP) vector production based on transient transfection. 相似文献
63.
Linder R Thoms I Pfenning I Schadowski R Möws V 《GMS Krankenhaushygiene interdisziplin?r》2011,6(1):Doc25
Multi-resistant pathogens are a serious problem on a considerable scale for the health sector. Patients with infections induced by multi-resistant bacteria cause enormous additional treatment costs of around 20,500 € per insured. Due to the recently used billing and documentation system there is a significant shortage of information transparency. The guidelines for hospital hygiene and infection prevention published by the Robert Koch Institute (RKI) include a presumption provision, which means that subject to compliance with these guidelines the observance of the current state of medical science is suspected. In case of a derogation, a scientific justification is necessary, which is used e.g. in connection with liability questions. Within the framework of legal reforms in 2011, the legislator aspires a nationwide improvement of hygiene quality in medical institutions and information transparency. Many specific issues about the general reporting obligation of infections with multi-resistant pathogens or about the standardized exchange of infection documentations between medical institution and health authority remain unresolved.Regional, cross-sectoral networks create the base to tackle targeted measures collectively and may develop sustainable and tailored solutions for their region. With these considerations in mind, the project HICARE was founded in Mecklenburg-Vorpommern. The project pursues the aim to develop an intervention strategy against the spread of multi-resistant pathogens. Health insurances make an important contribution to quality of medical treatment by participation. 相似文献
64.
Platelet P2Y12 receptor inhibition plays a pivotal role in preventing thrombotic vascular events in patients with ACS and in patients undergoing percutaneous coronary intervention (PCI). Among the P2Y12 receptor inhibitors, the group of thienopyridines include ticlopidine, clopidogrel and prasugrel, all of which are orally administered prodrugs leading to irreversible P2Y12 receptor inhibition. Non-thienopyridine derivatives including ticagrelor, cangrelor and elinogrel do not require metabolic activation and lead to a reversible P2Y12 receptor inhibition in contrast to thienopyridines. The extend of platelet inhibition is subject to the administered antiplatelet agent and influenced by individual genetic and clinical factors. Insufficient platelet inhibition, termed high platelet reactivity (HPR) is associated with an increased risk for ischemic events after PCI whereas exceeding platelet inhibition results in an increased bleeding risk. Pharmacologic properties and clinical outcome data differ substantially between the existing P2Y12 receptor inhibitors. Whether individualized antiplatelet treatment incorporating different P2Y12 receptor inhibitors improves patients' clinical outcomes warrants further investigation. 相似文献
65.
66.
67.
68.
Scheibe C Wartenburger I Wüstenberg T Kathmann N Villringer A Heekeren HR 《Human brain mapping》2006,27(7):545-551
Complete understanding of the neural correlates of cognitive processes requires investigation of both event- and state-related correlates of cognitive performance as well as their interaction. Neuroimaging studies using blocked designs confound these two types of processes and studies using event-related designs focus exclusively on the detection of transient effects. Recent fMRI studies used mixed blocked/event-related designs and found that transient and sustained activity can be dissociated, but it is not yet known how event-related and state-related processing interact. Here we used a phonological categorization paradigm in a mixed blocked/event-related design to investigate where in the brain transient activity interacts with sustained activity. Task difficulty was parametrically manipulated based on individually determined categorization thresholds. We found an interaction effect of transient and sustained activity in the left precuneus. In this cortical structure transient activity increased with increasing task difficulty, while sustained neural activity decreased with increasing task difficulty. Our data suggest that sustained activity is enhanced during processing of an easy task, presumably because of ongoing internally cued endogenous processing, still allowing effortless processing of transient stimuli. During performance of a difficult task, sustained activity in the precuneus is reduced to provide resources for processing incoming stimuli. Processing of stimuli that are expected to be difficult elicits increased transient responses independent of the actual physical properties of the stimuli. In showing an interaction between transient and sustained activity in the precuneus, the present results accommodate seemingly diverging results from previous studies using event-related or blocked designs and expand the knowledge emerging from previous studies using mixed blocked/event-related designs. 相似文献
69.
Karin Milde-Langosch Thomas Karn Volkmar Müller Isabell Witzel Achim Rody Markus Schmidt Ralph M. Wirtz 《Breast cancer research and treatment》2013,137(1):57-67
High proliferation rates are characteristic of cancer, and proliferation markers make up the majority of genes included in RNA-based prognostic gene signatures applied for breast cancer patients. Based on prior data on differences in molecular subgroups of breast cancer, we hypothesized that the significance of single proliferation markers might differ in luminal, Her2-positive and triple-negative subtypes. Therefore, we compared mRNA expression data of Ki67, TOP2A, and RacGAP1 using a pool of 562 Affymetrix U133A microarrays from breast cancer samples. “Luminal,” “triple-negative,” and “Her2-positive” subcohorts were defined by ESR1 and ERBB2 mRNA expression using pre-defined cut-offs. The analysis of the three potential proliferation markers revealed subtype-specific differences: in luminal carcinomas, expression of all three markers was a significant indictor of early recurrence in univariate and multivariate analysis, but RacGAP1 was superior to Ki67 and TOP2A in significance. In triple-negative tumors, only Ki67 was a significant and independent marker, whereas none of the markers showed a significant prognostic impact in Her2-positive cases. Within the group of luminal carcinomas, the proliferation markers had different impact depending on the treatment of patients: in untreated patients, Ki67, TOP2A, and RacGAP1 were significant and independent prognostic markers. In chemotherapy-treated patients, overexpression of all three markers was predictive for early recurrence, but only RacGAP1 retained significance in multivariate analysis. In contrast, RacGAP1 was the only predictive proliferation marker in the endocrine treatment group. These data point to subtype-specific differences in the relevance of proliferation-associated genes, and RacGAP1 might be a strong prognostic and predictive marker in the luminal subgroup. 相似文献
70.