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排序方式: 共有383条查询结果,搜索用时 468 毫秒
1.
Ana Rita Gomes Nasim Bahram Sangani Tiago G. Fernandes M. Margarida Diogo Leopold M. G. Curfs Chris P. Reutelingsperger 《International journal of molecular sciences》2020,21(24)
The central nervous system (CNS) is the most complex structure in the body, consisting of multiple cell types with distinct morphology and function. Development of the neuronal circuit and its function rely on a continuous crosstalk between neurons and non-neural cells. It has been widely accepted that extracellular vesicles (EVs), mainly exosomes, are effective entities responsible for intercellular CNS communication. They contain membrane and cytoplasmic proteins, lipids, non-coding RNAs, microRNAs and mRNAs. Their cargo modulates gene and protein expression in recipient cells. Several lines of evidence indicate that EVs play a role in modifying signal transduction with subsequent physiological changes in neurogenesis, gliogenesis, synaptogenesis and network circuit formation and activity, as well as synaptic pruning and myelination. Several studies demonstrate that neural and non-neural EVs play an important role in physiological and pathological neurodevelopment. The present review discusses the role of EVs in various neurodevelopmental disorders and the prospects of using EVs as disease biomarkers and therapeutics. 相似文献
2.
Seyedeh Nooshin Banitaba Dariush Semnani Elahe Heydari‐Soureshjani Behzad Rezaei Ali A Ensafi Ahmadreza Taghipour‐Jahromi 《Polymer International》2020,69(8):675-687
In this study, solvent‐free nanofibrous electrolytes were fabricated through an electrospinning method. Polyethylene oxide (PEO), lithium perchlorate and ethylene carbonate were used as polymer matrix, salt and plasticizer respectively in the electrolyte structures. Keggin‐type hetero polyoxometalate (Cu‐POM@Ru‐rGO, Ni‐POM@Ru‐rGO and Co‐POM@Ru‐rGO (POM, polyoxometalate; rGO, reduced graphene oxide)) nanoparticles were synthesized and inserted into the PEO‐based nanofibrous electrolytes. TEM and SEM analyses were carried out for further evaluation of the synthesized filler structures and the electrospun nanofibre morphologies. The fractions of free ions and crystalline phases of the as‐spun electrolytes were estimated by obtaining Fourier transform infrared and XRD spectra, respectively. The results showed a significant improvement in the ionic conductivity of the nanofibrous electrolytes by increasing filler concentrations. The highest ionic conductivity of 0.28 mS cm?1 was obtained by the introduction of 0.49 wt% Co‐POM@Ru‐rGO into the electrospun electrolyte at ambient temperature. Compared with solution‐cast polymeric electrolytes, the electrospun electrolytes present superior ionic conductivity. Moreover, the cycle stability of the as‐spun electrolytes was clearly improved by the addition of fillers. Furthermore, the mechanical strength was enhanced with the insertion of 0.07 wt% fillers to the electrospun electrolytes. The results implied that the prepared nanofibres are good candidates as solvent‐free electrolytes for lithium ion batteries. © 2020 Society of Chemical Industry 相似文献
3.
Heydari P. Pedram M. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2003,11(2):180-193
This paper is concerned with the analysis and optimization of the ground bounce in digital CMOS circuits. First, an analytical method for calculating the ground bounce is presented. The proposed method relies on accurate models of the short-channel MOS device and the chip-package interface parasitics. Next the effect of ground bounce on the propagation delay and the optimum tapering factor of a multistage buffer is discussed and a mathematical relationship for total propagation delay in the presence of the ground bounce is obtained. Effect of an on-chip decoupling capacitor on the ground bounce waveform and circuit speed is analyzed next and a closed form expression for the peak value of the differential-mode component of the ground bounce in terms of the on-chip decoupling capacitor is provided. Finally, a design methodology for controlling the switching times of the output drivers to minimize the ground bounce is presented. 相似文献
4.
Phase-locked loops (PLL) in radio-frequency (RF) and mixed analog-digital integrated circuits (ICs) experience substrate coupling due to the simultaneous circuit switching and power/ground (P/G) noise which translate to a timing jitter. In this paper. an analysis of the PLL timing jitter due to substrate noise resulting from P/G noise and large-signal switching is presented. A general comprehensive stochastic model of the substrate and P/G noise sources in very large-scale integration (VLSI) circuits is proposed. This is followed by calculation of the phase noise of the constituent voltage-controlled oscillator (VCO) in terms of the statistical properties of substrate and P/G noise. The PLL timing jitter is then predicted in response to the VCO phase noise. Our mathematical method is utilized to study the jitter-induced P/G noise in a CMOS PLL, which is designed and simulated in a 0.25-/spl mu/m standard CMOS process. A comparison between the results obtained by our mathematical model and those obtained by HSPICE simulation prove the accuracy of the predicted model. 相似文献
5.
Engineering with Computers - In this article, the 2D Chebyshev wavelets (CWs) are used for designing a proper procedure to solve the variable-order (VO) fractional version of the nonlinear... 相似文献
6.
Engineering with Computers - This paper introduces a new version for the nonlinear Ginzburg–Landau equation derived from fractal–fractional derivatives and proposes a computational... 相似文献
7.
In real scheduling problems, some disruptions and unexpected events may occur. These disruptions cause the initial schedule to quickly become infeasible and non-optimal. In this situation, an appropriate rescheduling method should be used. In this paper, a new approach has been proposed to achieve stable and robust schedule despite uncertain processing times and unexpected arrivals of new jobs. This approach is a proactive–reactive method which uses a two-step procedure. In the first step an initial robust solution is produced proactively against uncertain processing times using robust optimization approach. This initial robust solution is more insensitive against the fluctuations of processing times in future. In the next step, when an unexpected disruption occurs, an appropriate reactive method is adopted to deal with this unexpected event. In fact, in the second step, the reactive approach determines the best modified sequence after any unexpected disruption based on the classical objective and performance measures. The robustness measure is implemented in the reactive approach to increase the performance of the real schedule after disruption. Computational results indicate that this method produces better solutions in comparison with four classical heuristic approaches according to effectiveness and performance of solutions. 相似文献
8.
The effect of nickel and molybdenum concentrations on the phase transformation and mechanical properties of conventional 18Ni(350)
maraging steel has been investigated. Both of these elements act as strong austenite stabilizers. When the concentration of
molybdenum or nickel is greater than 7.5 or 24 wt %, respectively, the austenite phase remains stable up to room temperature.
In both molybdenum- and nickel-alloyed steels, the austenite phase could be transformed to martensite by either dipping the
material in liquid nitrogen or subjecting it to cold working. When 7.5 wt% Mo and 24 wt% Ni were added in combination, however,
the austenite phase obtained at room temperature did not transform to martensite when liquid-nitrogen quenched or even when
cold rolled to greater than 95% reduction. The aging response of these materials has also been investigated using optical,
scanning electron, and scanning transmission electron microscopy. 相似文献
9.
Zarghami Mahdi Safari Nasim Szidarovszky Ferenc Islam Shafiqul 《Water Resources Management》2015,29(12):4285-4303
Water Resources Management - This paper shows the utility of a new interval cooperative game theory as an effective water diplomacy tool to resolve competing and conflicting needs of water users... 相似文献
10.
The practice of service-based manufacturing, utilized in various industries, particularly in electronics, pharmaceuticals, and automotive, is on the rise as it improves enterprise effectiveness in dynamic markets. The mutual responsibilities between the supplier(s) and user(s) of such services are spelled out in defined-time-horizon contracts. While such contracts define mutual obligations of both parties on a tactical/operational level, the long-term strategic objectives of the parties may be in conflict. This paper is focused on studying the dynamics of manufacturing service contracts. It investigates the factors affecting the shape of the negotiation space for such contracts and also the way the space should be navigated in response to changing market conditions. The paper presents an analytical framework developed to facilitate behavior analysis of the actors involved in the contract. 相似文献