235 research outputs found

    A Survey and Analysis of Outsourcing in East China

    Get PDF
    The aim of this study is to investigate whether outsourcing activities in east china are associated with a theoretical framework derived from the literature. By the methodology of Statistics Package for the Social Science (SPSS), the results of survey indicate that outsourcing will more extensively practiced in the future, the principal outsourcing motivation are to reduce costs and focus on core businesses. The purchasing outsourcing has the largest correlation coefficients with short-term contract, the total outsourcing has a significant correlation coefficient with long-term contract at the level of =0.05. The findings indicate that high service quality and mutual trust are the main criteria for selecting outsourcing vendors. However, it is found that outsourcing satisfaction is generally low. The main benefits of outsourcing are to reduce cost, concentrate on core businesses and improve the service quality, while the main problems with outsourcing are legal disputes, disclosure of commercial secrets and conflicts with vendors.Outsourcing; strategy; contract; survey

    STUDY ON MECHANICAL BEHAVIOR OF CABLE - STAYED BRIDGE SUPPORT SYSTEM IN MULTI - FULCRUM UNBALANCED ROTATION

    Get PDF
    With the maturity and wide application of the bridge rotation construction technology, the single-fulcrum spherical hinge balance rotation can not meet the need of crossing over the high-speed railway catenary and other obstacles, so the unbalanced rotation construction is often needed. In order to ensure the stability and safety of the unbalanced rotation process, a multi-pivot rotation method is proposed. In this paper, the railway cable-stayed bridge over Harbin West Avenue is taken as the research object, and the multi-fulcrum rotating construction method over the metal contact network is adopted. The Abaqus finite element model is established, the influence of different rotation angular velocity, friction coefficient of slideway and position of support foot on the force of support system in the course of rotation is studied. The results show that, compared with the traditional single-pivot rotation, the force on the multi-pivot rotation support foot becomes the main force component, and the force on the spherical hinge decreases. The rotation angular velocity is positively correlated with Mises stress of the support foot and the spherical hinge. The friction coefficient of the slideway has a great influence on the force of the support foot. When the friction coefficient of the slideway changes in order of 0.02,0.04,0.06,0.08 and 0.1, the friction stress of the outer edge of the support foot increases linearly. Considering the force of spherical hinge and support foot, the best position of supporting foot is 7.3 m from the center of spherical hinge. The research in this paper can be used for reference in the future multi-pivot unbalanced rotation construction

    Computed Tomography-Based Radiomics in Predicting T Stage and Length of Esophageal Squamous Cell Carcinoma

    Get PDF
    Background: Because of the superficial and infiltrative spreading patterns of esophageal squamous cell carcinoma (ESCC), an accurate assessment of tumor extent is challenging using imaging-based clinical staging. Radiomics features extracted from pretreatment computed tomography (CT) or magnetic resonance imaging have shown promise in identifying tumor characteristics. Accurate staging is essential for planning cancer treatment, especially for deciding whether to offer surgery or radiotherapy (chemotherapy) in patients with locally advanced ESCC. Thus, this study aimed to evaluate the predictive potential of contrast-enhanced CT-based radiomics as a non-invasive approach for estimating pathological tumor extent in ESCC patients. Methods: Patients who underwent esophagectomy between October 2011 and September 2017 were retrospectively studied and included 116 patients with pathologically confirmed ESCC. Contrast-enhanced CT from the neck to the abdomen was performed in all patients during the 2 weeks before the operation. Radiomics features were extracted from segmentations, which were contoured by radiologists. Cluster analysis was performed to obtain clusters with similar radiomics characteristics, and chi-squared tests were used to assess differences in clinicopathological features and survival among clusters. Furthermore, a least absolute shrinkage and selection operator was performed to select radiomics features and construct a radiomics model. Receiver operating characteristic analysis was used to evaluate the predictive ability of the radiomics signatures. Results: All 116 ESCC patients were divided into two groups according to the cluster analysis. The chi-squared test showed that cluster-based radiomics features were significantly correlated with T stage (p = 0.0254) and tumor length (p = 0.0002). Furthermore, CT radiomics signatures exhibited favorable predictive performance for T stage (area under the curve [AUC] = 0.86, sensitivity = 0.77, and specificity = 0.87) and tumor length (AUC = 0.95, sensitivity = 0.92, and specificity = 0.91). Conclusions: CT contrast radiomics is a simple and non-invasive method that shows promise for predicting pathological T stage and tumor length preoperatively in ESCC patients and may aid in the accurate assessments of patients in combination with the existing examinations

    Catalytic trajectory of a dimeric nonribosomal peptide synthetase subunit with an inserted epimerase domain.

    Get PDF
    Nonribosomal peptide synthetases (NRPSs) are modular assembly-line megaenzymes that synthesize diverse metabolites with wide-ranging biological activities. The structural dynamics of synthetic elongation has remained unclear. Here, we present cryo-EM structures of PchE, an NRPS elongation module, in distinct conformations. The domain organization reveals a unique "H"-shaped head-to-tail dimeric architecture. The capture of both aryl and peptidyl carrier protein-tethered substrates and intermediates inside the heterocyclization domain and L-cysteinyl adenylate in the adenylation domain illustrates the catalytic and recognition residues. The multilevel structural transitions guided by the adenylation C-terminal subdomain in combination with the inserted epimerase and the conformational changes of the heterocyclization tunnel are controlled by two residues. Moreover, we visualized the direct structural dynamics of the full catalytic cycle from thiolation to epimerization. This study establishes the catalytic trajectory of PchE and sheds light on the rational re-engineering of domain-inserted dimeric NRPSs for the production of novel pharmaceutical agents

    Orexin-A protects against cerebral ischemia-reperfusion injury by inhibiting excessive autophagy through OX1R-mediated MAPK/ERK/mTOR pathway

    Get PDF
    Orexin A (OXA) is a neuroprotective peptide that exerts protective effects on multiple physiological and pathological processes. Activation of autophagy is linked to the occurrence of cerebral ischemia–reperfusion injury (CIRI); however, its function remains incompletely understood. In this study, OXA was sought to exert its neuroprotective role by regulating autophagy in oxygen and glucose deprivation and reoxygenation (OGD/R) model and middle cerebral artery occlusion (MCAO) model of rats, and to elucidate the underlying molecular mechanisms. Acridine orange (AO) staining was used to evaluate autophagic vacuoles. Cell viability was measured by CCK8. The levels of p-ERK1/2, t-ERK1/2, p-mTOR, LC3B, Beclin 1, and p62 were evaluated by western blotting. Apoptosis rate was detected by Hoechst 33342 staining and Terminal deoxynucleotidyltransferase–mediated dUTP nick-end labeling (TUNEL). OXA treatment alleviated neuronal apoptosis and significantly inhibited autophagy activity. Mechanistically, OXA exerted its neuroprotective effects in vivo and in vitro by suppressing over-activated autophagy by modulating OX1R-mediated MAPK/ERK/mTOR pathway. The results of this study elucidate the roles of autophagy in CIRI and the mechanisms underlying the neuroprotective action of OXA. Our findings could facilitate the development of novel therapeutics for ischemic stroke

    Single‐Cell Transcriptome Atlas and Regulatory Dynamics in Developing Cotton Anthers

    Get PDF
    Plant anthers are composed of different specialized cell types with distinct roles in plant reproduction. High temperature (HT) stress causes male sterility, resulting in crop yield reduction. However, the spatial expression atlas and regulatory dynamics during anther development and in response to HT remain largely unknown. Here, the first single‐cell transcriptome atlas and chromatin accessibility survey in cotton anther are established, depicting the specific expression and epigenetic landscape of each type of cell in anthers. The reconstruction of meiotic cells, tapetal cells, and middle layer cell developmental trajectories not only identifies novel expressed genes, but also elucidates the precise degradation period of middle layer and reveals a rapid function transition of tapetal cells during the tetrad stage. By applying HT, heterogeneity in HT response is shown among cells of anthers, with tapetal cells responsible for pollen wall synthesis are most sensitive to HT. Specifically, HT shuts down the chromatin accessibility of genes specifically expressed in the tapetal cells responsible for pollen wall synthesis, such as QUARTET 3 (QRT3) and CYTOCHROME P450 703A2 (CYP703A2), resulting in a silent expression of these genes, ultimately leading to abnormal pollen wall and male sterility. Collectively, this study provides substantial information on anthers and provides clues for heat‐tolerant crop creation

    An Anti-attack Model Based on Complex Network Theory in P2P networks

    Full text link
    Complex network theory is a useful way to study many real systems. In this paper, an anti-attack model based on complex network theory is introduced. The mechanism of this model is based on dynamic compensation process and reverse percolation process in P2P networks. The main purpose of the paper is: (i) a dynamic compensation process can turn an attacked P2P network into a power-law (PL) network with exponential cutoff; (ii) a local healing process can restore the maximum degree of peers in an attacked P2P network to a normal level; (iii) a restoring process based on reverse percolation theory connects the fragmentary peers of an attacked P2P network together into a giant connected component. In this way, the model based on complex network theory can be effectively utilized for anti-attack and protection purposes in P2P networks.Comment: arXiv admin note: excessive text overlap with arXiv:cond-mat/0504185, without attributio

    Biogeographic survey of soil bacterial communities across Antarctica

    Get PDF
    Background: Antarctica and its unique biodiversity are increasingly at risk from the effects of global climate change and other human influences. A significant recent element underpinning strategies for Antarctic conservation has been the development of a system of Antarctic Conservation Biogeographic Regions (ACBRs). The datasets supporting this classification are, however, dominated by eukaryotic taxa, with contributions from the bacterial domain restricted to Actinomycetota and Cyanobacteriota. Nevertheless, the ice-free areas of the Antarctic continent and the sub-Antarctic islands are dominated in terms of diversity by bacteria. Our study aims to generate a comprehensive phylogenetic dataset of Antarctic bacteria with wide geographical coverage on the continent and sub-Antarctic islands, to investigate whether bacterial diversity and distribution is reflected in the current ACBRs. Results: Soil bacterial diversity and community composition did not fully conform with the ACBR classification. Although 19% of the variability was explained by this classification, the largest differences in bacterial community composition were between the broader continental and maritime Antarctic regions, where a degree of structural overlapping within continental and maritime bacterial communities was apparent, not fully reflecting the division into separate ACBRs. Strong divergence in soil bacterial community composition was also apparent between the Antarctic/sub-Antarctic islands and the Antarctic mainland. Bacterial communities were partially shaped by bioclimatic conditions, with 28% of dominant genera showing habitat preferences connected to at least one of the bioclimatic variables included in our analyses. These genera were also reported as indicator taxa for the ACBRs. Conclusions: Overall, our data indicate that the current ACBR subdivision of the Antarctic continent does not fully reflect bacterial distribution and diversity in Antarctica. We observed considerable overlap in the structure of soil bacterial communities within the maritime Antarctic region and within the continental Antarctic region. Our results also suggest that bacterial communities might be impacted by regional climatic and other environmental changes. The dataset developed in this study provides a comprehensive baseline that will provide a valuable tool for biodiversity conservation efforts on the continent. Further studies are clearly required, and we emphasize the need for more extensive campaigns to systematically sample and characterize Antarctic and sub-Antarctic soil microbial communities. APsmQ8MphSAgg4BzZyqdNTVideo Abstrac

    A survey and analysis of outsourcing in East China

    Get PDF
    The aim of this study is to investigate whether outsourcing activities in east china are associated with a theoretical framework derived from the literature. By the methodology of Statistics Package for the Social Science (SPSS) , the results of survey indicate that outsourcing will more extensively practiced in the future, the principal outsourcing motivation are to reduce costs and focus on core businesses. The purchasing outsourcing has the largest correlation coefficients with short-term contract, the total outsourcing has a significant correlation coefficient with long-term contract at the level of α=0.05. The findings indicate that high service quality and mutual trust are the main criteria for selecting outsourcing vendors. However, it is found that outsourcing satisfaction is generally low. The main benefits of outsourcing are to reduce cost, concentrate on core businesses and improve the service quality, while the main problems with outsourcing are legal disputes, disclosure of commercial secrets and conflicts with vendors
    corecore