2,207 research outputs found

    CAF: Cluster Algorithm and A-Star with Fuzzy Approach for Lifetime Enhancement in Wireless Sensor Networks

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    Energy is a major factor in designing wireless sensor networks (WSNs). In particular, in the real world, battery energy is limited; thus the effective improvement of the energy becomes the key of the routing protocols. Besides, the sensor nodes are always deployed far away from the base station and the transmission energy consumption is index times increasing with the increase of distance as well. This paper proposes a new routing method for WSNs to extend the network lifetime using a combination of a clustering algorithm, a fuzzy approach, and an A-star method. The proposal is divided into two steps. Firstly, WSNs are separated into clusters using the Stable Election Protocol (SEP) method. Secondly, the combined methods of fuzzy inference and A-star algorithm are adopted, taking into account the factors such as the remaining power, the minimum hops, and the traffic numbers of nodes. Simulation results demonstrate that the proposed method has significant effectiveness in terms of balancing energy consumption as well as maximizing the network lifetime by comparing the performance of the A-star and fuzzy (AF) approach, cluster and fuzzy (CF)method, cluster and A-star (CA)method, A-star method, and SEP algorithm under the same routing criteria

    The yeast prion protein Ure2: Structure, function and folding

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    The Saccharomyces cerevisiae protein Ure2 functions as a regulator of nitrogen metabolism and as a glutathione-dependent peroxidase. Ure2 also has the characteristics of a prion, in that it can undergo a heritable conformational change to an aggregated state; the prion form of Ure2 loses the regulatory function, but the enzymatic function appears to be maintained. A number of factors are found to affect the prion properties of Ure2, including mutation and expression levels of molecular chaperones, and the effect of these factors on structure and stability are being investigated. The relationship between structure, function and folding for the yeast prion Ure2 are discussed

    Evidence of Dark Contents in the Center of NGC 6517

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    Millisecond pulsars can serve as effective probes to investigate the presence of Intermediate-mass Black Holes (IMBHs) within Galactic globular clusters (GCs). Based on the standard structure models for GCs, we conduct simulations to analyze the distributions of pulsar accelerations within the central region of NGC 6517. By comparing the measured accelerations of pulsars obtained from their period derivatives P˙\dot P to the simulated distribution profiles, we demonstrate that a central excess of dark mass is required to account for the measured accelerations. Our analysis, which relies on existing pulsar timing observations, is currently unable to differentiate between two possible scenarios: an IMBH precisely situated at the core of the cluster with mass ≳9000−3000+4000 M⊙\gtrsim 9000^{+4000}_{-3000}~M_{\odot}, or a central concentration of stellar mass dark remnants with a comparable total mass. However, with additional acceleration measurements from a few more pulsars in the cluster, it will be possible to differentiate the source of the nonluminous matter.Comment: 6 pages, 3 figures, 1 table. Accepted for publication in MNRA

    Antioxidant activities of protein hydrolysates obtained from the housefly larvae

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    The housefly is an important resource insect and the housefly larvae are ideal source of food additives. The housefly larvae protein hydrolysates were obtained by enzymatic hydrolysis by alcalase and neutral proteinase. Their antioxidant activities were investigated, including the superoxide and hydroxyl radicalscavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, reducing power and metal chelating activity. The antioxidant activities of both hydrolysates increased with their increasing concentrations. The alcalase hydrolysate (AH) showed higher scavenging activities against hydroxyl radical and superoxide anion radical at low concentrations and higher metal-chelating activity than the neutral proteinase hydrolysate (NPH). The NPH exhibited higher scavenging activity against DPPH free radical and higher reducing power than the AH. Both hydrolysates showed more than 50% superoxide anion radical-scavenging activity at 10 μg/mL. These results indicate that both housefly larvae protein hydrolysates display high antioxidant activities and they could serve as potential natural antioxidant food additives

    In vivo real-time imaging of gemcitabine-leaded growth inhibition in the orthotopic transplantation model of human pancreatic tumor

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    AbstractHuman xenograft mouse models, which have been used in cancer research for over a century, provided significant advances for our understanding of this multifaceted family of diseases. Orthotopic transplantation tumor models are emerging as the preference for cancer research due to the increasing clinical relevance over subcutaneous mouse models. In this study, a stable luciferase-expressed Capan-2 cell line was constructed and the expression of luciferase was tested. The results showed that the luminorescence intensity of Capan-2Luc cells was associated with the number of cells and the minimal detectable cell population was 600cells/well. We established an orthotopic transplantation model of pancreatic cancer using Capan-2Luc cell line in athymic mice and investigated the inhibitory effects of gemcitabine (Gem) in vitro and in vivo. Optical imaging system was applied to evaluate the tumor growth of orthotopic transplantation model in vivo. The results suggested that the orthotopic transplantation model of pancreatic cancer was well established and the luminorescence intensity of Gem-treated group was markedly lower than that of control group with an inhibitory rate of 56.8% (P<0.001). Our orthotopic transplantation model of pancreatic cancer and real-time imaging observation method established in this study could be an ideal model and a useful tool for therapeutic approaches for pancreatic cancers
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