547 research outputs found

    Modelling consumer satisfaction based on online reviews using the improved Kano model from the perspective of risk attitude and aspiration

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    With the development of e-commerce, an increasing number of online reviews can serve as a promising data source for enterprises to improve online products. This paper proposes a method for modelling consumer satisfaction based on online reviews using the improved Kano model from the perspective of risk attitude and aspiration. Firstly, the attributes concerned by consumers are extracted from online reviews, and sentiment analysis of the extracted attributes is carried out using Standford CoreNLP. Secondly, to identify the types of product attributes, an improved Kano model is proposed based on the effects of product attributes on consumer total utility. On this basis, different attribute types are illustrated from the perspective of risk attitude. Then, the consumer aspirations are mined based on the risk attitudes of different attributes and the attribute impact on consumer satisfaction. According to the risk attitudes and aspirations of different attributes, the quantified satisfaction functions are constructed to provide more objective and accurate improvement suggestions. Finally, the proposed method is applied to the hotel service improvement to illustrate the effectiveness. First published online 13 April 202

    A Dynamic-Order Fractional Dynamic System

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    Multi-system interaction is an important and difficult problem in physics. Motivated by the experimental result of an electronic circuit element "Fractor", we introduce the concept of dynamic-order fractional dynamic system, in which the differential-order of a fractional dynamic system is determined by the output signal of another dynamic system. The new concept offers a comprehensive explanation of physical mechanism of multi-system interaction. The properties and potential applications of dynamic-order fractional dynamic systems are further explored with the analysis of anomalous relaxation and diffusion processes.Comment: 10 pages, 5 figure

    Assessment of Burden Among Family Caregivers of Schizophrenia: Psychometric Testing for Short-Form Zarit Burden Interviews

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    Objective: Although various short forms of Zarit Burden Interview (ZBI) have been developed, there is a lack of standard psychometric testing and comparison among them. The study aims to examine the psychometric properties of ten short versions of the most frequently used ZBI among a sample of schizophrenia caregivers and to find the one with the best performance.Methods: Cross-sectional door-to-door survey of ZBI-22 and a series of validated instrument data from 327 family caregivers of schizophrenia patients in a Chinese rural community were conducted from October 2015 to January 2016. Reliability was assessed using McDonald's omega coefficient (ω). Validity including concurrent validity, known group's validity, and criterion validity were assessed by Spearman correlations and Mann-Whitney U tests. Overall discrimination ability was evaluated using the area under the receiver operating characteristic curve (AUC).Results: Reliability was generally good for all short forms (ω = 0.69–0.84), except for the Gort ZBI-4 (ω = 0.58), which is acceptable considering its small item numbers. Concurrent validity was good across all various ZBI forms with significant negative correlations with patient's function (r = −0.34 to −0.48, p < 0.01), as well as significant positive correlations with caregiver's depression (r = 0.49–0.65, p < 0.01), and anxiety symptoms (r = 0.45–0.58, p < 0.01). Known groups' validity (carers with disease vs. without disease; carers being parents vs. spouse vs. others) showed inconsistent results among various short forms. Criterion validity was generally good for all short forms with significant positive correlations with Family Burden Interview Schedule (r = 0.67–0.75, p < 0.01), except for the Higginson ZBI-1(r = 0.57, p < 0.01). Discriminative ability was also good for all short forms (AUC range: 0.85–0.99), with various cutpoints proposed. Among all ten short forms, the Ballesteros ZBI-12 and the Gort ZBI-7 outperformed others with almost equally good performance in comprehensive psychometric testing.Conclusions: This study provides support for the reliability, validity, and discriminative ability of the ten various short forms of ZBI for use among schizophrenia family caregivers, with the Ballesteros ZBI-12 and the Gort ZBI-7 endorsed as the best ones

    Piezoresistive Strain Sensors Made from Carbon Nanotubes Based Polymer Nanocomposites

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    In recent years, nanocomposites based on various nano-scale carbon fillers, such as carbon nanotubes (CNTs), are increasingly being thought of as a realistic alternative to conventional smart materials, largely due to their superior electrical properties. Great interest has been generated in building highly sensitive strain sensors with these new nanocomposites. This article reviews the recent significant developments in the field of highly sensitive strain sensors made from CNT/polymer nanocomposites. We focus on the following two topics: electrical conductivity and piezoresistivity of CNT/polymer nanocomposites, and the relationship between them by considering the internal conductive network formed by CNTs, tunneling effect, aspect ratio and piezoresistivity of CNTs themselves, etc. Many recent experimental, theoretical and numerical studies in this field are described in detail to uncover the working mechanisms of this new type of strain sensors and to demonstrate some possible key factors for improving the sensor sensitivity

    Salmonella Outer Protein B Suppresses Colitis Development via Protecting Cell From Necroptosis

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    Salmonella effectors translocated into epithelial cells contribute to the pathogenesis of infection. They mediate epithelial cell invasion and subsequent intracellular replication. However, their functions in vivo have not been well-identified. In this study, we uncovered a role for Salmonella outer protein B (SopB) in modulating necroptosis to facilitate bacteria escape epithelial cell and spread to systemic sites through a Salmonella-induced colitis model. Mice infected with SopB deleted strain ΔsopB displayed increased severity to colitis, reduced mucin expression and increased bacterial translocation. In vitro study, we found there was an increased goblet cell necroptosis following ΔsopB infection. Consistently, mice infected with ΔsopB had a strong upregulation of mixed lineage kinase domain-like (MLKL) phosphorylation. Deletion of MLKL rescued severity of tissue inflammatory, improved mucin2 expression and abolished the increased bacterial translocation in mice infected with ΔsopB. Intriguingly, the expression of sopB in LS174T cells was downregulated. The temporally regulated SopB expression potentially switched the role from epithelial cell invasion to bacterial transmission. Collectively, these results indicated a role for SopB in modulating the onset of necroptosis to increased bacteria pathogenesis and translocated to systemic sites

    Magnetohydrodynamic simulation of the interaction between two interplanetary magnetic clouds and its consequent geoeffectiveness: 2. Oblique collision

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    The numerical studies of the interplanetary coupling between multiple magnetic clouds (MCs) are continued by a 2.5-dimensional ideal magnetohydrodynamic (MHD) model in the heliospheric meridional plane. The interplanetary direct collision (DC) / oblique collision (OC) between both MCs results from their same/different initial propagation orientations. Here the OC is explored in contrast to the results of the DC (Xiong et al., 2007). Both the slow MC1 and fast MC2 are consequently injected from the different heliospheric latitudes to form a compound stream during the interplanetary propagation. The MC1 and MC2 undergo contrary deflections during the process of oblique collision. Their deflection angles of ∣δθ1∣|\delta \theta_1| and ∣δθ2∣|\delta \theta_2| continuously increase until both MC-driven shock fronts are merged into a stronger compound one. The ∣δθ1∣|\delta \theta_1|, ∣δθ2∣|\delta \theta_2|, and total deflection angle Δθ\Delta \theta (Δθ=∣δθ1∣+∣δθ2∣\Delta \theta = |\delta \theta_1| + |\delta \theta_2|) reach their corresponding maxima when the initial eruptions of both MCs are at an appropriate angular difference. Moreover, with the increase of MC2's initial speed, the OC becomes more intense, and the enhancement of δθ1\delta \theta_1 is much more sensitive to δθ2\delta \theta_2. The ∣δθ1∣|\delta\theta_1| is generally far less than the ∣δθ2∣|\delta\theta_2|, and the unusual case of ∣δθ1∣≃∣δθ2∣|\delta\theta_1|\simeq|\delta\theta_2| only occurs for an extremely violent OC. But because of the elasticity of the MC body to buffer the collision, this deflection would gradually approach an asymptotic degree. Therefore, the deflection due to the OC should be considered for the evolution and ensuing geoeffectiveness of interplanetary interaction among successive coronal mass ejections (CMEs).Comment: 51 pages, 13 figures, JGR - Space Physics, in pres

    Polymorphisms in thymidylate synthase gene and susceptibility to breast cancer in a Chinese population: a case-control analysis

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    BACKGROUND: Accumulative evidence suggests that low folate intake is associated with increased risk of breast cancer. Polymorphisms in genes involved in folate metabolism may influence DNA methylation, nucleotide synthesis, and thus individual susceptibility to cancer. Thymidylate synthase (TYMS) is a key enzyme that participates in folate metabolism and catalyzes the conversion of dUMP to dTMP in the process of DNA synthesis. Two potentially functional polymorphisms [a 28-bp tandem repeat in the TYMS 5'-untranslated enhanced region (TSER) and a 6-bp deletion/insertion in the TYMS 3'-untranslated region (TS 3'-UTR)] were suggested to be correlated with alteration of thymidylate synthase expression and associated with cancer risk. METHODS: To test the hypothesis that polymorphisms of the TYMS gene are associated with risk of breast cancer, we genotyped these two polymorphisms in a case-control study of 432 incident cases with invasive breast cancer and 473 cancer-free controls in a Chinese population. RESULTS: We found that the distribution of TS3'-UTR (1494del6) genotype frequencies were significantly different between the cases and controls (P = 0.026). Compared with the TS3'-UTR del6/del6 wild-type genotype, a significantly reduced risk was associated with the ins6/ins6 homozygous variant genotype (adjusted OR = 0.58, 95% CI = 0.35–0.97) but not the del6/ins6 genotype (OR = 1.09, 95% CI = 0.82–1.46). Furthermore, breast cancer risks associated with the TS3'-UTR del6/del6 genotype were more evident in older women, postmenopausal subjects, individuals with a younger age at first-live birth and individuals with an older age at menarche. However, there was no evidence for an association between the TSER polymorphism and breast cancer risks. CONCLUSION: These findings suggest that the TS3'-UTR del6 polymorphism may play a role in the etiology of breast cancer. Further larger population-based studies as well as functional evaluation of the variants are warranted to confirm our findings

    HBsAg Inhibits the Translocation of JTB into Mitochondria in HepG2 Cells and Potentially Plays a Role in HCC Progression

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    Background and Aims: The expression of the jumping translocation breakpoint (JTB) gene is upregulated in malignant liver tissues; however, JTB is associated with unbalanced translocations in many other types of cancer that suppress JTB expression. No comprehensive analysis on its function in human hepatocellular carcinoma (HCC) has been performed to date. We aimed to define the biological consequences for interaction between JTB and HBsAg in HCC cell lines. Methods: We employed the stable transfection to establish small HBsAg expressing HepG2 cell line, and stably silenced the JTB expression using short hairpin RNA in HepG2 cell line. The effects of JTB and small HBsAg in vitro were determined by assessing cell apoptosis and motility. Results: Silencing of JTB expression promoted cancer cell motility and reduced cell apoptosis, which was significantly enhanced by HBs expression. Expression of HBsAg inhibited the translocation of JTB to the mitochondria. Furthermore, silencing of the JTB resulted in an increase in the phosphorylation of p65 in HepG2 cells and HepG2-HBs cells, whereas HBsAg expression decreased the phosphorylation of p65. The silencing of JTB in HepG2-HBs cells conferred increased advantages in cell motility and anti-apoptosis. Conclusion: HBsAg inhibited the translocation of JTB to the mitochondria and decreased the phosphorylation of p65 through the interaction with JTB, After JTB knockdown, HBsAg exhibited a stronger potential to promote tumor progression. Our data suggested that JTB act as a tumor suppressor gene in regards to HBV infection and its activation might be applied as a therapeutic strategy for in control of HBV related HCC development.National Natural Science Foundation of China [30971362, 81072013]; Fundamental Research Funds for the Central Universities in China [2010111082]; Key Projects for Technology Plan of Fujian Province in China [2009D020]; Foundation of Health Bureau of Fujian in China [2007CXB8, 3502z20077046]; Foundation of Health Bureau of Xiamen in China [2007CXB8, 3502z20077046

    Genetic Variants at 1p11.2 and Breast Cancer Risk: A Two-Stage Study in Chinese Women

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    BACKGROUND: Genome-wide association studies (GWAS) have identified several breast cancer susceptibility loci, and one genetic variant, rs11249433, at 1p11.2 was reported to be associated with breast cancer in European populations. To explore the genetic variants in this region associated with breast cancer in Chinese women, we conducted a two-stage fine-mapping study with a total of 1792 breast cancer cases and 1867 controls. METHODOLOGY/PRINCIPAL FINDINGS: Seven single nucleotide polymorphisms (SNPs) including rs11249433 in a 277 kb region at 1p11.2 were selected and genotyping was performed by using TaqMan® OpenArray™ Genotyping System for stage 1 samples (878 cases and 900 controls). In stage 2 (914 cases and 967 controls), three SNPs (rs2580520, rs4844616 and rs11249433) were further selected and genotyped for validation. The results showed that one SNP (rs2580520) located at a predicted enhancer region of SRGAP2 was consistently associated with a significantly increased risk of breast cancer in a recessive genetic model [Odds Ratio (OR)  =  1.66, 95% confidence interval (CI)  =  1.16-2.36 for stage 2 samples; OR  =  1.51, 95% CI  =  1.16-1.97 for combined samples, respectively]. However, no significant association was observed between rs11249433 and breast cancer risk in this Chinese population (dominant genetic model in combined samples: OR  =  1.20, 95% CI  =  0.92-1.57). CONCLUSIONS/SIGNIFICANCE: Genotypes of rs2580520 at 1p11.2 suggest that Chinese women may have different breast cancer susceptibility loci, which may contribute to the development of breast cancer in this population
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