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排序方式: 共有5282条查询结果,搜索用时 31 毫秒
21.
Emilly Sigoli Rosangela Aline Anto Maria Paula Guerreiro Tatiana Oliveira Passos de Araújo Patty Karina dos Santos Daiane Leite da Roza Dilson E. Rassier Anabelle Silva Cornachione 《International journal of molecular sciences》2022,23(9)
Duchenne muscular dystrophy (DMD) is a muscle disease characterized by the absence of the protein dystrophin, which causes a loss of sarcolemma integrity, determining recurrent muscle injuries, decrease in muscle function, and progressive degeneration. Currently, there is a need for therapeutic treatments to improve the quality of life of DMD patients. Here, we investigated the effects of a low-intensity aerobic training (37 sessions) on satellite cells, peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α protein (PGC-1α), and different types of fibers of the psoas muscle from mdx mice (DMD experimental model). Wildtype and mdx mice were randomly divided into sedentary and trained groups (n = 24). Trained animals were subjected to 37 sessions of low-intensity running on a motorized treadmill. Subsequently, the psoas muscle was excised and analyzed by immunofluorescence for dystrophin, satellite cells, myosin heavy chain (MHC), and PGC-1α content. The minimal Feret’s diameters of the fibers were measured, and light microscopy was applied to observe general morphological features of the muscles. The training (37 sessions) improved morphological features in muscles from mdx mice and caused an increase in the number of quiescent/activated satellite cells. It also increased the content of PGC-1α in the mdx group. We concluded that low-intensity aerobic exercise (37 sessions) was able to reverse deleterious changes determined by DMD. 相似文献
22.
M. J. P. Biggs M. C. Milone L. C. Santos A. Gondarenko S. J. Wind 《Journal of the Royal Society Interface》2011,8(63):1462-1471
T-cell activation via antigen presentation is associated with the formation of a macromolecular membrane assembly termed the immunological synapse (IS). The genesis of the IS and the onset of juxtacrine signalling is characterized by the formation of cell membrane microclusters and the organization of such into segregated microdomains. A central zone rich in T-cell receptor (TCR)–major histocompatibility complex microclusters termed the central supramolecular activation cluster (cSMAC) forms the bullseye of this structure, while the cellular interface surrounding the cSMAC is characterized by regions enriched in adhesion and co-stimulatory molecules. In vitro, the study of dynamic TCR microcluster coalescence and IS genesis in T-cell populations is hampered by cell migration within the culture system and resolution constraints resulting from lateral cell–cell contact. Here, we detail a novel system describing the fabrication of micropit arrays designed to sequester single T-cell–antigen presenting cell (APC) conjugates and promote IS formation in the horizontal imaging plane for high-resolution studies of microcluster dynamics. We subsequently use this system to describe the formation of the cSMAC in T-cell populations and to investigate the morphology of the interfacial APC membrane. 相似文献
23.
Formalising the Fisherman's Folly puzzle 总被引:2,自引:0,他引:2
This paper investigates the challenging problem of encoding the common sense knowledge involved in the manipulation of spatial objects from a reasoning about actions and change perspective. In particular, we propose a formal solution to a puzzle composed of non-trivial objects (such as holes and strings) assuming a version of the Situation Calculus written over first-order Equilibrium Logic, whose models generalise the stable model semantics. 相似文献
24.
Proton Transport in Electrospun Hybrid Organic–Inorganic Membranes: An Illuminating Paradox 下载免费PDF全文
Leslie Dos Santos Manuel Maréchal Armel Guillermo Sandrine Lyonnard Simona Moldovan Ovidiu Ersen Ozlem Sel Hubert Perrot Christel Laberty‐Robert 《Advanced functional materials》2016,26(4):594-604
Chemistry and processing have to be judiciously combined to structure the membranes at various length scales to achieve efficient properties for polymer electrolyte membrane fuel cell to make it competitive for transport. Characterizing the proton transport at various length and space scales and understanding the interplays between the nanostructuration, the confinement effect, the interactions, and connectivity are consequently needed. The goal here is to study the proton transport in multiscale, electrospun hybrid membranes (EHMs) at length scales ranging from molecular to macroscopic by using complementary techniques, i.e., electrochemical impedance spectroscopy, pulsed field gradient‐NMR spectroscopy, and quasielastic neutron scattering. Highly conductive hybrid membranes (EHMs) are produced and their performances are rationalized taken into account the balances existing between local interaction driven mobility and large‐scale connectivity effects. It is found that the water diffusion coefficient can be locally decreased (2 × 10?6 cm2 s?1) due to weak interactions with the silica network, but the macroscopic diffusion coefficient is still high (9.6 × 10?6 cm2 s?1). These results highlight that EHMs have slow dynamics at the local scale without being detrimental for long‐range proton transport. This is possible through the nanostructuration of the membranes, controlled via processing and chemistry. 相似文献
25.
Denis Alcides Rezende Gilberto dos Santos Madeira Leonardo de Souza Mendes Gean Davis Breda Bruno Bogaz Zarpelão Frederico de Carvalho Figueiredo 《Telematics and Informatics》2014
Making information and telecommunications available is a permanent challenge for cities concerned to their social, urban and local planning and development, focused on life quality of their citizens and on the effectiveness of public management. Such a challenge requires the involvement of everyone in the city. The objective is to describe the information and telecommunications project from the planning of a digital city carried out in Vinhedo-SP, Brazil. It was built as a telecommunications infrastructure of the kind of “open access metropolitan area networks” which enables the integration of citizens in a single telecommunications environment. The research methodology was emphasized by a case study which turned to be a research-action, comprising the municipal administration and its local units. The results achieved describe, by means of a methodology, the phases, sub-phases, activities, approval points and resulting products, and formalize their respective challenges and difficulties. The contributions have to do with the practical feasibility of the project and execution of its methodology. The conclusion reiterates the importance of the project, collectively implemented and accepted, as a tool to help the management of cities, in the implementation of Strategic Digital City Projects, in the decisions of public administration managers, and in the quality of life of their citizens. 相似文献
26.
A study on arc-induced long-period fibre gratings (LPFGs) revealed that their strain sensitivity depends on the electric current of the arc discharge. Based on that property, a sensor scheme comprising two concatenated LPFGs was implemented for discrimination of temperature and strain effects. This sensor presented resolutions of /spl plusmn/0.1/spl deg/C//spl radic/Hz and /spl plusmn/35 /spl mu//spl epsiv///spl radic/Hz, respectively. 相似文献
27.
There is evidence to indicate that the effects of new product and service innovations change over time as a result of learning and competition. However, there have not been any studies of the effects of learning and competition on the impacts of innovative information technology (IT) applications. This paper presents the results of an extensive study of the effects of very early investments in automated teller machines (ATMs) by banks, on market share and overall bank performance. The study spans the period from 1971 to 1984 and includes 2534 banks from across the United States. The results indicate that the impacts of early ATM investments can best be described by exponential and logistic models, indicating that the benefits were very small at first, but increased rapidly after a few years. In addition, the benefits obtained by the earliest adopters were larger than those obtained by the banks that adopted later. These results have important implications for IT investment decisions. The results also suggest that cross-sectional studies, conducted soon after an application is installed, may fail to find benefits even if large benefits are obtained 相似文献
28.
A nonlinear regeneration pulsed oscillator driven by a monochromatic source has been built. Subharmonics of the resonance carrier/modulation are measured with an accuracy of 10-10 thanks to the use of a double beats measurement set-up. The multiscale analysis of frequency readings reveals a rich fine structure which is in agreement with the nonlinear topological approach of synchronized states. 相似文献
29.
J. C. Vazquez V. Champac A. M. ZiesemerJr. R. Reis I. C. Teixeira M. B. Santos J. P. Teixeira 《Analog Integrated Circuits and Signal Processing》2012,70(2):249-263
The impact of parametric variations on digital circuit performance is increasing in nanometer Integrated Circuits (IC), namely
of Process, power supply Voltage and Temperature (PVT) variations. Moreover, circuit aging also impacts circuit performance,
especially due to Negative Bias Temperature Instability (NBTI) effect. A growing number of physical defects manifest themselves
as delay faults (at production, or during product lifetime). On-chip, on-line delay monitoring, as a circuit failure prediction
technique, can be an attractive solution to guarantee correct operation in safety–critical applications. Safe operation can
be monitored, by predictive delay fault detection. A delay monitoring methodology and a novel delay sensor (to be selectively
inserted in key locations in the design and to be activated according to user’s requirements) is proposed, and a 65 nm design
is presented. The proposed sensor is programmable, allowing delay monitoring for a wide range of delay values, and has been
optimized to exhibit low sensitivity to PVT and aging-induced variations. Two MOSFET models—BPTM and ST—have been used. As
abnormal delays can be monitored, regardless of their origin, both parametric variations and physical defects impact on circuit
performance can be identified. Simulation results show that the sensor is effective in identifying such abnormal delays, due
to NBTI-induced aging and to resistive open defects. 相似文献
30.
Hamidreza Esmaielpour Vincent R. Whiteside Jinfeng Tang Sangeetha Vijeyaragunathan Tetsuya D. Mishima Shayne Cairns Michael B. Santos Bin Wang Ian R. Sellers 《Progress in Photovoltaics: Research and Applications》2016,24(5):591-599
InAs/AlAsxSb1 − x quantum wells are investigated for their potential as hot carrier solar cells. Continuous wave power and temperature‐dependent photoluminescence indicate a transition in the dominant hot carrier relaxation process from conventional phonon‐mediated carrier relaxation below 90 K to a regime where inhibited radiative recombination dominates the hot carrier relaxation at elevated temperatures. At temperatures below 90 K, photoluminescence measurements are consistent with type‐I quantum wells that exhibit hole localization associated with alloy/interface fluctuations. At elevated temperatures, hole delocalization reveals the true type‐II band alignment, where it is observed that inhibited radiative recombination due to the spatial separation of the charge carriers dominates hot carrier relaxation. This decoupling of phonon‐mediated relaxation results in robust hot carriers at higher temperatures, even at lower excitation powers. These results indicate type‐II quantum wells offer potential as practical hot carrier systems. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献