1,454 research outputs found

    Hawking Radiation of Apparent Horizon in a FRW Universe

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    Hawking radiation is an important quantum phenomenon of black hole, which is closely related to the existence of event horizon of black hole. The cosmological event horizon of de Sitter space is also of the Hawking radiation with thermal spectrum. By use of the tunneling approach, we show that there is indeed a Hawking radiation with temperature, T=1/2πr~AT=1/2\pi \tilde r_A, for locally defined apparent horizon of a Friedmann-Robertson-Walker universe with any spatial curvature, where r~A\tilde r_A is the apparent horizon radius. Thus we fill in the gap existing in the literature investigating the relation between the first law of thermodynamics and Friedmann equations, there the apparent horizon is assumed to have such a temperature without any proof. In addition, we stress the implication of the Hawking temperature associated with the apparent horizon.Comment: Latex, 9 paages; v2 published versio

    WAITER : a wearable personal healthcare and emergency aid system

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    2007-2008 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    A precise correcting method for the study of the superhard material using nanoindentation tests

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    2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    WAITER: A Wearable Personal Healthcare and Emergency Aid System

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    The emerging pervasive computing is regarded as a promising solution to the systems of personal healthcare and emergency aid, which can monitor personal health status in a real-time manner and automatically issue the alert for medical aids in case of emergency. However, the implementation of such a system is not trivial due to the issues, including 1) the system operations without complicated caregiver aid to reduce cost of human resource, 2) vital sensor deployment for user comfort, 3) on-site vital data process and storage for energy saving in data transmission, and 4) timely communication with healthcare centre for reporting users' health status and seeking urgent medical aids. In this paper, we propose a novel wearable personal healthcare and emergency aid system, namely WAITER. Our system does not require specific caregiver aid. WAITER just employs the tiny wearable sensors to continuously collect user's vital signals and Bluetooth device to transmit the sensory data to a mobile phone, which can perform on-site vital data storage and process. After local data process, the mobile phone can use its GSM module to periodically report users ' health status to the healthcare centre and issue alert for medical aids once detecting emergency. We believe that WAITER can satisfy the requirements of real personal healthcare and emergency aid system.Department of ComputingDepartment of Health Technology and InformaticsRefereed conference pape

    Protective effect of wild Corni fructus methanolic extract against acute alcoholic liver injury in mice

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    Background: In Chinese folk medicine, Corni fructus (C. fructus) has traditionally been used to improve liver function, although the mechanism underlying its activity remains unclear. The aim of the present study was to evaluate the protective effects of wild C. fructus methanolic extract against acute alcoholic liver injury.Methods: Alcohol was administered to mice for three consecutive days, either alone or in combination with C. fructus methanolic extract (50, 100, or 200mg/kg body weight/d). Serum and liver tissue were collected from the animals and subjected to biochemical and histopathological analyses.Results:C. fructus significantly alleviated alcohol-induced liver injury by reducing serum alanine aminotransferase, aspartate aminotransferase, and thiobarbituric acid reactive species, inhibiting hydroxyl radicals (center dot OH), and increasing total superoxide dismutase, glutathione peroxidase, and glutathione in the liver (P<0.05). In addition, the C. fructus treatment inhibited the expression and activity of cytochrome P450 2E1 (P<0.05)Conclusions:C. fructus could be a promising natural substance for ameliorating acute alcohol-induced oxidative stress and hepatic injury.- This work was supported by the Construction Project of Shaanxi Collaborative Innovation Center (2015, Shaanxi Sci-tech University); High-End Foreign Experts Recruitment Program [Grant GDW20146100228]; and Key Construction Program of International Cooperation Base in S&T Shaanxi Province, China [Grant 2015SD0018].info:eu-repo/semantics/publishedVersio

    PGB pair production at LHC and ILC as a probe of the topcolor-assisted technicolor models

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    The topcolor-assisted technicolor (TC2) model predicts some light pseudo goldstone bosons (PGBs), which may be accessible at the LHC or ILC. In this work we study the pair productions of the charged or neutral PGBs at the LHC and ILC. For the productions at the LHC we consider the processes proceeding through gluon-gluon fusion and quark-antiquark annihilation, while for the productions at the ILC we consider both the electron-positron collision and the photon-photon collision. We find that in a large part of parameter space the production cross sections at both colliders can be quite large compared with the low standard model backgrounds. Therefore, in future experiments these productions may be detectable and allow for probing TC2 model.Comment: 26 pages, 16 figures. slight changes in the text; notations for curves changed; references adde

    Identification, Characterization, and Expression of a Novel P450 Gene Encoding CYP6AE25 from the Asian Corn Borer, Ostrinia furnacalis

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    An allele of the cytochrome P450 gene, CYP6AE14, named CYP6AE25 (GenBank accession no. EU807990) was isolated from the Asian com borer, Ostrinia fumacalis (Guenée) (Lepidoptera: Pyralidae) by RT-PCR. The cDNA sequence of CYP6AE25 is 2315 bp in length and contains a 1569 nucleotides open reading frame encoding a putative protein with 523 amino acid residues and a predicted molecular weight of 59.95 kDa and a theoretical pI of 8.31. The putative protein contains the classic heme-binding sequence motif F××G×××C×G (residues 451–460) conserved among all P450 enzymes as well as other characteristic motifs of all cytochrome P450s. It shares 52% identity with the previously published sequence of CYP6AE14 (GenBank accession no. DQ986461) from Helicoverpa armigera. Phylogenetic analysis of amino acid sequences from members of various P450 families indicated that CYP6AE25 has a closer phylogenetic relationship with CYP6AE14 and CYP6B1 that are related to metabolism of plant allelochemicals, CYP6D1 which is related to pyrethroid resistance and has a more distant relationship to CYP302A1 and CYP307A1 which are related to synthesis of the insect molting hormones. The expression level of the gene in the adults and immature stages of O. furnacalis by quantitative real-time PCR revealed that CYP6AE25 was expressed in all life stages investigated. The mRNA expression level in 3rd instar larvae was 12.8- and 2.97-fold higher than those in pupae and adults, respectively. The tissue specific expression level of CYP6AE25 was in the order of midgut, malpighian tube and fatty body from high to low but was absent in ovary and brain. The analysis of the CYP6AB25 gene using bioinformatic software is discussed

    Evaluating the repeatability of corneal elevation through calculating the misalignment between Successive topography measurements during the follow up of LASIK

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    The study aims to evaluate, using the Iterative Closest Point (ICP) algorithm, the repeatability of successive corneal elevation measurements taken post-LASIK. Two topography maps of 98 LASIK participants were recorded preoperatively (Pre), 1 month (Pos1M) and 3 months postoperatively (Pos3M). Elevation of the second measurement was fitted to the first measurement by calculating using ICP, and correcting for, both translational and rotational misalignment components. The RMS of elevation differences between anterior corneal measurements were statistically significant post-LASIK compared to preoperation (P < 0.05). A misalignment ratio used to describe the weighting of the elevation difference caused by misalignment relative to the total difference remained stable (0.40 and 0.23 for anterior and posterior corneal surfaces, respectively) in different periods. The study also considered the combined misalignment parameter (CM), which represents the total effect of all individual misalignment components on the repeatability of corneal topography maps. CM was significantly greater post-LASIK relative to pre-LASIK (P < 0.05). Overall, the contribution of misalignment to the total difference between successive corneal measurements remained stable pre and post operation, while the combined effect of refractive error correction and optical diameter appeared to have a significant influence on the elevation repeatability in the early stages of the follow up period

    Bioinformatics approaches for cross-species liver cancer analysis based on microarray gene expression profiling

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    BACKGROUND: The completion of the sequencing of human, mouse and rat genomes and knowledge of cross-species gene homologies enables studies of differential gene expression in animal models. These types of studies have the potential to greatly enhance our understanding of diseases such as liver cancer in humans. Genes co-expressed across multiple species are most likely to have conserved functions. We have used various bioinformatics approaches to examine microarray expression profiles from liver neoplasms that arise in albumin-SV40 transgenic rats to elucidate genes, chromosome aberrations and pathways that might be associated with human liver cancer. RESULTS: In this study, we first identified 2223 differentially expressed genes by comparing gene expression profiles for two control, two adenoma and two carcinoma samples using an F-test. These genes were subsequently mapped to the rat chromosomes using a novel visualization tool, the Chromosome Plot. Using the same plot, we further mapped the significant genes to orthologous chromosomal locations in human and mouse. Many genes expressed in rat 1q that are amplified in rat liver cancer map to the human chromosomes 10, 11 and 19 and to the mouse chromosomes 7, 17 and 19, which have been implicated in studies of human and mouse liver cancer. Using Comparative Genomics Microarray Analysis (CGMA), we identified regions of potential aberrations in human. Lastly, a pathway analysis was conducted to predict altered human pathways based on statistical analysis and extrapolation from the rat data. All of the identified pathways have been known to be important in the etiology of human liver cancer, including cell cycle control, cell growth and differentiation, apoptosis, transcriptional regulation, and protein metabolism. CONCLUSION: The study demonstrates that the hepatic gene expression profiles from the albumin-SV40 transgenic rat model revealed genes, pathways and chromosome alterations consistent with experimental and clinical research in human liver cancer. The bioinformatics tools presented in this paper are essential for cross species extrapolation and mapping of microarray data, its analysis and interpretation
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