438 research outputs found
Formation of Aluminum-Doped Zinc Oxide Nanocrystals via the Benzylamine Route at Low Reaction Kinetics
The influence of essential process parameters on the adjustability of specific process and particulate properties of aluminumādoped zinc oxide (AZO) nanocrystals during synthesis via the benzylamine route at low reaction kinetics is demonstrated by enabling timeāresolved access of the selected measurement technique. It is shown that the validity of the pseudoāfirstāorder process kinetics could be extended to the minimum operable reaction kinetics. On the other hand, the impacts of the process temperature and the initial precursor concentration on both the process kinetics and the particle morphology are discussed. The obtained data provide a versatile tool for precise process control by adjusting defined applicationāspecific particle properties of AZO during synthesis
Chiasma
Newspaper reporting on events at the Boston University School of Medicine in the 1960s
State-Dependent Differences in Functional Connectivity in Young Children With Autism Spectrum Disorder
AbstractBackgroundWhile there is increasing evidence of altered brain connectivity in autism, the degree and direction of these alterations in connectivity and their uniqueness to autism has not been established. The aim of the present study was to compare connectivity in children with autism to that of typically developing controls and children with developmental delay without autism.MethodsWe assessed EEG spectral power, coherence, phase lag, Pearson and partial correlations, and epileptiform activity during the awake, slow wave sleep, and REM sleep states in 137 children aged 2 to 6years with autism (n=87), developmental delay without autism (n=21), or typical development (n=29).FindingsWe found that brain connectivity, as measured by coherence, phase lag, and Pearson and partial correlations distinguished children with autism from both neurotypical and developmentally delayed children. In general, children with autism had increased coherence which was most prominent during slow wave sleep.InterpretationFunctional connectivity is distinctly different in children with autism compared to samples with typical development and developmental delay without autism. Differences in connectivity in autism are state and region related. In this study, children with autism were characterized by a dynamically evolving pattern of altered connectivity
Lack of a-disintegrin-and-metalloproteinase ADAM10 leads to intracellular accumulation and loss of shedding of the cellular prion protein in vivo
<p>Abstract</p> <p>Background</p> <p>The cellular prion protein (PrP<sup>C</sup>) fulfils several yet not completely understood physiological functions. Apart from these functions, it has the ability to misfold into a pathogenic scrapie form (PrP<sup>Sc</sup>) leading to fatal transmissible spongiform encephalopathies. Proteolytic processing of PrP<sup>C </sup>generates N- and C-terminal fragments which play crucial roles both in the pathophysiology of prion diseases and in transducing physiological functions of PrP<sup>C</sup>. A-disintegrin-and-metalloproteinase 10 (ADAM10) has been proposed by cell culture experiments to be responsible for both shedding of PrP<sup>C </sup>and its Ī±-cleavage. Here, we analyzed the role of ADAM10 in the proteolytic processing of PrP<sup>C </sup><it>in vivo</it>.</p> <p>Results</p> <p>Using neuron-specific <it>Adam10 </it>knockout mice, we show that ADAM10 is the sheddase of PrP<sup>C </sup>and that its absence <it>in vivo </it>leads to increased amounts and accumulation of PrP<sup>C </sup>in the early secretory pathway by affecting its posttranslational processing. Elevated PrP<sup>C </sup>levels do not induce apoptotic signalling via p53. Furthermore, we show that ADAM10 is not responsible for the Ī±-cleavage of PrP<sup>C</sup>.</p> <p>Conclusion</p> <p>Our study elucidates the proteolytic processing of PrP<sup>C </sup>and proves a role of ADAM10 in shedding of PrP<sup>C </sup><it>in vivo</it>. We suggest that ADAM10 is a mediator of PrP<sup>C </sup>homeostasis at the plasma membrane and, thus, might be a regulator of the multiple functions discussed for PrP<sup>C</sup>. Furthermore, identification of ADAM10 as the sheddase of PrP<sup>C </sup>opens the avenue to devising novel approaches for therapeutic interventions against prion diseases.</p
Cognitive change is more positively associated with an active lifestyle than with training interventions in older adults at risk of dementia: a controlled interventional clinical trial
Background: While observational studies show that an active lifestyle including cognitive, physical, and social activities is associated with a reduced risk of cognitive decline and dementia, experimental evidence from corresponding training interventions is more inconsistent with less pronounced effects. The aim of this study was to evaluate and compare training- and lifestyle-related changes in cognition. This is the first study investigating these associations within the same time period and sample.
Methods: Fifty-four older adults at risk of dementia were assigned to 10 weeks of physical training, cognitive training, or a matched wait-list control condition. Lifestyle was operationalized as the variety of self-reported cognitive, physical, and social activities before study participation. Cognitive performance was assessed with an extensive test battery prior to and after the intervention period as well as at a 3-month follow-up. Composite cognition measures were obtained by means of a principal component analysis. Training- and lifestyle-related changes in cognition were analyzed using linear mixed effects models. The strength of their association was compared with paired t-tests.
Results: Neither training intervention improved global cognition in comparison to the control group (p = .08). In contrast, self-reported lifestyle was positively associated with benefits in global cognition (p < .001) and specifically in memory (p < .001). Moreover, the association of an active lifestyle with cognitive change was significantly stronger than the benefits of the training interventions with respect to global cognition (ps < .001) and memory (ps < .001). Conclusions: The associations of an active lifestyle with cognitive change over time in a dementia risk group were stronger than the effects of short-term, specific training interventions. An active lifestyle may differ from training interventions in dosage and variety of activities as well as intrinsic motivation and enjoyment. These factors might be crucial for designing novel interventions, which are more efficient than currently available training interventions
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