23 research outputs found

    Access control for hybrid femtocell network based on AGV mechanism

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    As most of voice calls and data traffic originates indoors, femtocells have been one of the most promising trends in LTE, which are short-range, cost-beneficial and low-power cellular home base stations that can improve indoor coverage and voice/data quality of service (QoS). One of the major challenges for femtocell network is the access control. The hybrid access control mechanism, as a tradeoff between open and closed scenario, is the most promising access mechanism from which both users and operators benefit. Femtocell user equipments (FUEs) select femtocell access points (FAPs) according to their reported channel information which FAPs confidently own, and selfish FAPs have incentive to report larger information to win greater opportunity to be selected. Considering the aforementioned truth-telling in access control issue, this paper proposes access control scheme for hybrid femtocell network based on Arrow-d'Aspremont-Gerard-Varet (AGV) mechanism. Close form for the payment is given. Moreover, the access control scheme is nearly optimal performances with low computational complexity compared with the optimal access scheme. Furthermore, the simulation results demonstrate that the access control scheme can be apply to hybrid femtocell network. ? 2014 Global IT Research Institute (GIRI).EICPCI-S(ISTP)

    Increased Migration of Monocytes in Essential Hypertension Is Associated with Increased Transient Receptor Potential Channel Canonical Type 3 Channels

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    Increased transient receptor potential canonical type 3 (TRPC3) channels have been observed in patients with essential hypertension. In the present study we tested the hypothesis that increased monocyte migration is associated with increased TRPC3 expression. Monocyte migration assay was performed in a microchemotaxis chamber using chemoattractants formylated peptide Met-Leu-Phe (fMLP) and tumor necrosis factor-α (TNF-α). Proteins were identified by immunoblotting and quantitative in-cell Western assay. The effects of TRP channel-inhibitor 2–aminoethoxydiphenylborane (2-APB) and small interfering RNA knockdown of TRPC3 were investigated. We observed an increased fMLP-induced migration of monocytes from hypertensive patients compared with normotensive control subjects (246±14% vs 151±10%). The TNF-α-induced migration of monocytes in patients with essential hypertension was also significantly increased compared to normotensive control subjects (221±20% vs 138±18%). In the presence of 2-APB or after siRNA knockdown of TRPC3 the fMLP-induced monocyte migration was significantly blocked. The fMLP-induced changes of cytosolic calcium were significantly increased in monocytes from hypertensive patients compared to normotensive control subjects. The fMLP-induced monocyte migration was significantly reduced in the presence of inhibitors of tyrosine kinase and phosphoinositide 3-kinase. We conclude that increased monocyte migration in patients with essential hypertension is associated with increased TRPC3 channels

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Effects of Trace Si Addition on the Microstructures and Tensile Properties of Ti-3Al-8V-6Cr-4Mo-4Zr Alloy

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    The microstructural evolution and tensile properties of Ti-3Al-8V-6Cr-4Mo-4Zr titanium alloys with various Si contents were investigated. The results revealed that the addition of trace Si and the presence of Zr induced the formation of (TiZr)6Si3 silicides, in the size range from 100 nm to 300 nm. The fine silicide precipitates refined β grains. The tensile strength increased about 40 MPa due to precipitation strengthening and grain refinement, and the ductility of the two alloys was similar. The tensile fracture mode of the alloys was dimple ductile fracture

    An uplink timing synchronization method for GEO mobile SAT-LTE system

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    In this paper, we investigate uplink timing synchronization problem in GEO mobile SAT-LTE system. Firstly, we introduce a two-hop GEO multi-beam satellite communication model, and simply analyze the issues of existed timing synchronization methods. After that, we set the round trip delay (RTD) of furthest point in a beam as the timing reference (TR), with this reference, an available uplink timing synchronization method named modified frame alignment (MFA) is proposed, which take into consideration of LTE signalling and minimum scheduling unit. In the end, the simulation result demonstrates that the proposed method has higher system efficiency, better Qos performance for delay sensitive services, and higher degree of commonality with the terrestrial LTE networks. ? 2014 Global IT Research Institute (GIRI).EICPCI-S(ISTP)

    In-Depth Sulfhydryl-Modified Cellulose Fibers for Efficient and Rapid Adsorption of Cr(VI)

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    As one of the hazardous heavy metal ion pollutants, Cr(VI) has attracted much attention in the sewage treatment research field due to its wide distribution range and serious toxicity. In this paper, cellulose fibers were prepared by wet spinning and followed by freeze drying, resulting in large porosity. Subsequently, in-depth sulfhydryl modification was applied with cellulose fibers for efficient and rapid adsorption of Cr(VI). The maximum adsorption capacity of sulfhydryl-modified cellulose fibers to Cr(VI) can reach 120.60 mg g−1, the adsorption equilibrium can be achieved within 300 s, and its adsorption rate can reach 0.319 mg g−1 s−1. The results show that the in-depth sulfhydryl-modified cellulose fibers perform excellent adsorption capacity for chromium, and are also available for other heavy metal ions. At the same time, the low cost and environmentally friendly property of the as-synthesized material also demonstrate its potential for practical usage for the treatment of heavy metal ion pollution in waste water

    HTO/Cellulose Aerogel for Rapid and Highly Selective Li+ Recovery from Seawater

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    To achieve rapid and highly efficient recovery of Li+ from seawater, a series of H2TiO3/cellulose aerogels (HTO/CA) with a porous network were prepared by a simple and effective method. The as-prepared HTO/CA were characterized and their Li+ adsorption performance was evaluated. The obtained results revealed that the maximum capacity of HTO/CA to adsorb Li+ was 28.58 ± 0.71 mg g−1. The dynamic k2 value indicated that the Li+ adsorption rate of HTO/CA was nearly five times that of HTO powder. Furthermore, the aerogel retained extremely high Li+ selectivity compared with Mg2+, Ca2+, K+, and Na+. After regeneration for five cycles, the HTO/CA retained a Li+ adsorption capacity of 22.95 mg g−1. Moreover, the HTO/CA showed an excellent adsorption efficiency of 69.93% ± 0.04% and high selectivity to Li+ in actual seawater. These findings confirm its potential as an adsorbent for recovering Li+ from seawater
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