2,290 research outputs found

    A Study on Trust of E-commerce Market Based on Multi-agents Model

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    The process of the trust production and transfer is both stochastic and rational. In this article, we analyze the characters of this process in consumer’s social networks, by dividing consumers and merchants into two types: Risk-aversion type and Risk-neutral type for consumers, high-grade and low-grade for merchants respectively. Based on multi-agent NETLogo system, three kinds of virtual social networks are constructed, which are the risk-neutral without institution, risk-aversion without institution, risk-aversion but with good institution. The rules of the production and transfer of trust in consumer-to-consumer and merchant-to-consumers are defined. Based on a series of computational experiments and statistical comparison, we draw a conclusion that the characters of consumers do not change the trend of e-business market scale, but only change the equilibrium value. On the other hand, a risk-aversion with good institutional society can boost market to have a highly upward trend and be self-stable. Consequentially, this article indirectly proved of the essentials for establishing the institution-based trust

    4-{(Z)-(sec-Butyl­amino)(phen­yl)methyl­ene}-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

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    In the title compound, C21H23N3O, the dihedral angles formed by the pyrazolone ring with two phenyl rings are 10.38 (8) and 76.94 (6)°. The sec-butyl­amino group is disordered over two positions, with refined site-occupancy factors of 0.730 (4) and 0.270 (4). The compound could potentially be ligand stabilized in the solid state in a keto–enamine tautomeric form. The amine functionality is involved in an intra­molecular N—H⋯O hydrogen bond, while weak inter­molecular C—H⋯O and C—H⋯N hydrogen bonds participate in the formation of the crystal structure

    Use of low-dose computed tomography to assess pulmonary tuberculosis among healthcare workers in a tuberculosis hospital

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    BACKGROUND: According to the World Health Organization, China is one of 22 countries with serious tuberculosis (TB) infections and one of the 27 countries with serious multidrug-resistant TB strains. Despite the decline of tuberculosis in the overall population, healthcare workers (HCWs) are still at a high risk of infection. Compared with high-income countries, the TB prevalence among HCWs is higher in low- and middle-income countries. Low-dose computed tomography (LDCT) is becoming more popular due to its superior sensitivity and lower radiation dose. However, there have been no reports about active pulmonary tuberculosis (PTB) among HCWs as assessed with LDCT. The purposes of this study were to examine PTB statuses in HCWs in hospitals specializing in TB treatment and explore the significance of the application of LDCT to these workers. METHODS: This study retrospectively analysed the physical examination data of healthcare workers in the Beijing Chest Hospital from September 2012 to December 2015. Low-dose lung CT examinations were performed in all cases. The comparisons between active and inactive PTB according to the CT findings were made using the Pearson chi-square test or the Fisher’s exact test. Comparisons between the incidences of active PTB in high-risk areas and non-high-risk areas were performed using the Pearson chi-square test. Analyses of active PTB were performed according to different ages, numbers of years on the job, and the risks of the working areas. Active PTB as diagnosed by the LDCT examinations alone was compared with the final comprehensive diagnoses, and the sensitivity and positive predictive value were calculated. RESULTS: A total of 1 012 participants were included in this study. During the 4-year period of medical examinations, active PTB was found in 19 cases, and inactive PTB was found in 109 cases. The prevalence of active PTB in the participants was 1.24%, 0.67%, 0.81%, and 0.53% for years 2012 to 2015. The corresponding incidences of active PTB among the tuberculosis hospital participants were 0.86%, 0.41%, 0.54%, and 0.26%. Most HCWs with active TB (78.9%, 15/19) worked in the high-risk areas of the hospital. There was a significant difference in the incidences of active PTB between the HCWs who worked in the high-risk and non-high-risk areas (odds ratio [OR], 14.415; 95% confidence interval (CI): 4.733 – 43.896). Comparisons of the CT signs between the active and inactive groups via chi-square tests revealed that the tree-in-bud, cavity, fibrous shadow, and calcification signs exhibited significant differences (P = 0.000, 0.021, 0.001, and 0.024, respectively). Tree-in-bud and cavity opacities suggest active pulmonary tuberculosis, whereas fibrous shadow and calcification opacities are the main features of inactive pulmonary tuberculosis. Comparison with the final comprehensive diagnoses revealed that the sensitivity and positive predictive value of the diagnoses of active PTB based on LDCT alone were 100% and 86.4%, respectively. CONCLUSIONS: Healthcare workers in tuberculosis hospitals are a high-risk group for active PTB. Yearly LDCT examinations of such high-risk groups are feasible and necessary. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40249-017-0274-6) contains supplementary material, which is available to authorized users

    (4Z)-4-[(4-Methoxy­benzyl­amino)(phen­yl)methyl­ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

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    In the title compound, C25H23N3O2, the dihedral angles formed by the pyrazolone ring with the three aromatic rings are 14.59 (7), 79.35 (5) and 87.10 (6)°. Three intra­molecular C—H⋯O, C—H⋯N and N—H⋯O hydrogen-bond inter­actions are present. The crystal structure is stabilized by two weak inter­molecular C—H⋯O and C—H⋯N hydrogen-bond inter­actions

    Genome-wide identification and expression analysis of serine proteases and homologs in the silkworm Bombyx mori

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    <p>Abstract</p> <p>Background</p> <p>Serine proteases (SPs) and serine proteases homologs (SPHs) are a large group of proteolytic enzymes, with important roles in a variety of physiological processes, such as cell signalling, defense and development. Genome-wide identification and expression analysis of serine proteases and their homologs in the silkworm might provide valuable information about their biological functions.</p> <p>Results</p> <p>In this study, 51 SP genes and 92 SPH genes were systematically identified in the genome of the silkworm <it>Bombyx mori</it>. Phylogenetic analysis indicated that six gene families have been amplified species-specifically in the silkworm, and the members of them showed chromosomal distribution of tandem repeats. Microarray analysis suggests that many silkworm-specific genes, such as members of SP_fam12, 13, 14 and 15, show expression patterns that are specific to tissues or developmental stages. The roles of SPs and SPHs in resisting pathogens were investigated in silkworms when they were infected by <it>Escherichia coli</it>, <it>Bacillus bombysepticus</it>, <it>Batrytis bassiana </it>and <it>B. mori </it><it>nucleopolyhedrovirus</it>, respectively. Microarray experiment and real-time quantitative RT-PCR showed that 18 SP or SPH genes were significantly up-regulated after pathogen induction, suggesting that SP and SPH genes might participate in pathogenic microorganism resistance in <it>B. mori</it>.</p> <p>Conclusion</p> <p>Silkworm SP and SPH genes were identified. Comparative genomics showed that SP and SPH genes belong to a large family, whose members are generated mainly by tandem repeat evolution. We found that silkworm has species-specific SP and SPH genes. Phylogenetic and microarray analyses provide an overview of the silkworm SP and SPHs, and facilitate future functional studies on these enzymes.</p

    Poly[[(N,N-dimethyl­formamide-κO)(μ3-pyrazine-2,3-dicarboxyl­ato-κ4 N 1,O2:O 3:O 3)copper(II)] monohydrate]

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    In the title compound, {[Cu(C6H2N2O4)(C3H7NO)]·H2O}n, the Cu(II) atom is coordinated by an N,O-bidentate pyrazine-2,3-dicarboxyl­ate (pzdc) dianion, two O atoms from two other pzdc anions and one O atom from the dimethlyformamide ligand, forming a distorted square-pyramidal CuNO4 geometry. The polymeric character of the structure is established by the formation of layers parallel to (100) via bridging pzdc ligands. O—H⋯O hydrogen bonding between water mol­ecules and uncoordinated carboxyl­ate O atoms leads to additional stabilization of the structure
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