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   1192篇
  免费   106篇
  2023年   7篇
  2022年   20篇
  2021年   32篇
  2020年   11篇
  2019年   25篇
  2018年   23篇
  2017年   19篇
  2016年   49篇
  2015年   96篇
  2014年   85篇
  2013年   78篇
  2012年   111篇
  2011年   93篇
  2010年   42篇
  2009年   57篇
  2008年   67篇
  2007年   52篇
  2006年   64篇
  2005年   61篇
  2004年   50篇
  2003年   49篇
  2002年   41篇
  2001年   10篇
  2000年   2篇
  1999年   12篇
  1998年   8篇
  1997年   11篇
  1996年   11篇
  1995年   6篇
  1994年   8篇
  1993年   10篇
  1992年   13篇
  1991年   4篇
  1990年   7篇
  1988年   3篇
  1987年   8篇
  1985年   5篇
  1984年   4篇
  1983年   2篇
  1982年   4篇
  1981年   4篇
  1980年   6篇
  1977年   2篇
  1974年   2篇
  1972年   4篇
  1970年   2篇
  1959年   3篇
  1955年   1篇
  1954年   1篇
  1949年   1篇
排序方式: 共有1298条查询结果,搜索用时 15 毫秒
971.
Lessons from implementing quality control systems in an academic research consortium to improve Good Scientific Practice and reproducibility. Subject Categories: Microbiology, Virology & Host Pathogen Interaction, Science Policy & Publishing

Low reproducibility rates within biomedical research negatively impact productivity and translation. One promising approach to enhance the transfer of robust results from preclinical research into clinically relevant and transferable data is the systematic implementation of quality measures in daily laboratory routines.
Although many universities expect their scientists to adhere to GSPs, they often neither systematically support, nor monitor the quality of their research activities.
Today''s fast‐evolving research environment needs effective quality measures to ensure reproducibility and data integrity (Macleod et al, 2014; Begley et al, 2015; Begley & Ioannidis, 2015; Baker, 2016). Academic research institutions and laboratories may be as committed to good scientific practices (GSPs) as their counterparts in the biotech and pharmaceutical industry but operate largely without clearly defined standards (Bespalov et al, 2021; Emmerich et al, 2021). Although many universities expect their scientists to adhere to GSPs, they often neither systematically support, nor monitor the quality of their research activities. Peer review of publications is still regarded as the primary validation of quality control in academic research. However, reviewers only assess work after it has been performed—often over years—and interventions in the experimental process are thus no longer possible.The reasons for the lack of dedicated quality management (QM) implementations in academic laboratories include an anticipated overload of regulatory tasks that could negatively affect productivity, concerns about the loss of scientific freedom, and importantly, limited resources in academia and academic funding schemes.  相似文献   
972.
973.
974.
Targeting toxic amyloid beta (Aβ) oligomers is currently a very attractive drug development strategy for treatment of Alzheimer´s disease. Using mirror-image phage display against Aβ1-42, we have previously identified the fully D-enantiomeric peptide D3, which is able to eliminate Aβ oligomers and has proven therapeutic potential in transgenic Alzheimer´s disease animal models. However, there is little information on the pharmacokinetic behaviour of D-enantiomeric peptides in general. Therefore, we conducted experiments with the tritium labelled D-peptide D3 (3H-D3) in mice with different administration routes to study its distribution in liver, kidney, brain, plasma and gastrointestinal tract, as well as its bioavailability by i.p. and p.o. administration. In addition, we investigated the metabolic stability in liver microsomes, mouse plasma, brain, liver and kidney homogenates, and estimated the plasma protein binding. Based on its high stability and long biological half-life, our pharmacokinetic results support the therapeutic potential of D-peptides in general, with D3 being a new promising drug candidate for Alzheimer´s disease treatment.  相似文献   
975.
976.
977.
Molecular Genetics and Genomics - Mutants of E. coli specifically deficient for the enzyme altronic hydrolyase have been isolated. These strains are unable to metabolize galacturonate but still...  相似文献   
978.
979.
The growth rates of pikeperch (Lucioperca lucioperca L.) originating from two lowlands ponds in the north of Belgium, one of which is heated by the effluents of power plants, were compared by means of scalimetry and operculometry. The overall condition of the fish in both ponds was also investigated. The pikeperch grew significantly faster in heated water, although overall condition was comparable. Seasonal variations resulted in the heated pond arriving at a temperature higher than the optimum.  相似文献   
980.
Positron emission tomography with [18F] fluorodeoxyglucose (FDG-PET) plays a well-established role in assisting early detection of frontotemporal lobar degeneration (FTLD). Here, we examined the impact of intensity normalization to different reference areas on accuracy of FDG-PET to discriminate between patients with mild FTLD and healthy elderly subjects. FDG-PET was conducted at two centers using different acquisition protocols: 41 FTLD patients and 42 controls were studied at center 1, 11 FTLD patients and 13 controls were studied at center 2. All PET images were intensity normalized to the cerebellum, primary sensorimotor cortex (SMC), cerebral global mean (CGM), and a reference cluster with most preserved FDG uptake in the aforementioned patients group of center 1. Metabolic deficits in the patient group at center 1 appeared 1.5, 3.6, and 4.6 times greater in spatial extent, when tracer uptake was normalized to the reference cluster rather than to the cerebellum, SMC, and CGM, respectively. Logistic regression analyses based on normalized values from FTLD-typical regions showed that at center 1, cerebellar, SMC, CGM, and cluster normalizations differentiated patients from controls with accuracies of 86%, 76%, 75% and 90%, respectively. A similar order of effects was found at center 2. Cluster normalization leads to a significant increase of statistical power in detecting early FTLD-associated metabolic deficits. The established FTLD-specific cluster can be used to improve detection of FTLD on a single case basis at independent centers – a decisive step towards early diagnosis and prediction of FTLD syndromes enabling specific therapies in the future.  相似文献   
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