780 research outputs found

    Green Synthesis of Magnetite Nanoparticles (via Thermal Decomposition Method) with Controllable Size and Shape

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    Magnetite (Fe3O4) nanoparticles with controllable size and shape were synthesized by the thermal decomposition method. In contrast to previously reported thermal decomposition methods, our synthesis method had utilized a much cheaper and less toxic iron precursor, iron acetylacetonate (Fe(acac)3), and environmentally benign and non-toxic polyethylene oxide (PEO) was being used as the solvent and surfactant simultaneously. Fe3O4 nanoparticles of controllable size and shape were prepared by manipulating the synthesis parameters such as precursor concentrations, reaction durations and surfactants

    Wolbachia wStri blocks Zika virus growth at two independent stages of viral replication

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    Mosquito-transmitted viruses are spread globally and present a great risk to human health. Among the many approaches investigated to limit the diseases caused by these viruses are attempts to make mosquitos resistant to virus infection. Coinfection of mosquitos with the bacterium Wolbachia pipientis from supergroup A is a recent strategy employed to reduce the capacity for major vectors in the Aedes mosquito genus to transmit viruses, including dengue virus (DENV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Recently, a supergroup B Wolbachia wStri, isolated from Laodelphax striatellus, was shown to inhibit multiple lineages of ZIKV in Aedes albopictus cells. Here, we show that wStri blocks the growth of positive-sense RNA viruses DENV, CHIKV, ZIKV, and yellow fever virus by greater than 99.9%. wStri presence did not affect the growth of the negative-sense RNA viruses LaCrosse virus or vesicular stomatitis virus. Investigation of the stages of the ZIKV life cycle inhibited by wStri identified two distinct blocks in viral replication. We found a reduction of ZIKV entry into wStri-infected cells. This was partially rescued by the addition of a cholesterol-lipid supplement. Independent of entry, transfected viral genome was unable to replicate in Wolbachia-infected cells. RNA transfection and metabolic labeling studies suggested that this replication defect is at the level of RNA translation, where we saw a 66% reduction in mosquito protein synthesis in wStri-infected cells. This study’s findings increase the potential for application of wStri to block additional arboviruses and also identify specific blocks in viral infection caused by Wolbachia coinfection.R01 AI099210 - NIAID NIH HHSPublished versio

    Finite element analysis of tibia with osteogenesis imperfecta: the influence of considering cancellous bone in model reconstruction

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    The paper aims to develop the finite element (FE) models of tibia with Osteogenesis Imperfecta (OI) based on a patient-specific computed tomography (CT)-images. Two types of FE model have been developed. The first model was set the tibia bone as a single solid model whereas the second model consists of cortical bone and cancellous bone. The developed FE models were used for FE analysis using Voxelcon under various loadings, and then the results of the different models were compared. It was found that the single model yields relatively in agreement to piecewise model, with percentage different of below than 2% for all loading conditions. It seems that the reconstructed FE model considering the cancellous bone did not give significant effect compared to the solid model that neglecting the microstructure of cancellous bone. Hence, we can conclude that the single solid FE model with OI has predicted well, at least for the present boundary conditions, although the cancellous bone was neglected in the model reconstruction

    A study of the efficiency of the class of WW-states as a quantum channel

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    Recently, a new class of WW-states has been defined by Agarwal and Pati \cite{agarwal} and it has been shown that they can be used as a quantum channel for teleportation and superdense coding. In this work, we identify those three-qubit states from the set of the new class of WW-states which are most efficient or suitable for quantum teleportation. We show that with some probability W1>=(1/2)(100>+010>+2001>)|W_1>=(1/2)(|100>+|010>+\sqrt{2}|001>) is best suited for teleportation channel in the sense that it does not depend on the input state.Comment: 7 pages, Late

    Green and lean sustainable development path in China: Guanxi, practices and performance

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    Globalisation has created both drivers and pressure for Chinese organisations to enhance their business performance as well as environmental performance. Green and lean practice is emerging as a critical approach for Chinese organisations to achieve sustainable development and improve organisational performance. By conducting empirical studies from 172 respondents on green and lean practice in different Chinese organisations, this research shows how green and lean practice affects organisational performance and how this association is affected by guanxi. The findings explain that guanxi between organisational partners improves the positive effect of green and lean practice on organisational performance. The results of this paper offer helpful insights into how managers should enhance their guanxi initiatives, in order to improve environmental and business performance over their supply chains. The paper also suggests the limitations of this research, as well as directions for future research

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

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    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters
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