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  • Author: Yi Tang x
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Power line communication (PLC) is a promising technique for information transmission using existing power lines. We analytically model a finite-source PLC network subject to channel noise (disturbance) and evaluate its call-level performance through a queueing theoretic framework. The proposed PLC network model consists of a base station (BS), which is located at a transformer station and connected to the backbone communication networks, and a number of subscriber stations that are interconnected with each other and with the BS via the power line transmission medium. An orthogonal frequency division multiplexing based transmission technique is assumed to be used for providing the transmission channels in a frequency spectrum. The channels are subject to failure during service due to disturbance. We determine the steady-state solution of the proposed model and derive a set of performance metrics of interest. Numerical and simulation results are presented to show the derived metrics with respect to different system parameters. The proposed modeling method can be used for evaluation and design of future PLC networks.

Abstract

A series of cationic perfluoralkyl acrylate copolymer latices were prepared by two-stage emulsifier-free emulsion polymerization method. Perfluoroalkylethyl acrylate (FEA) and [2-(methacryloxy)ethyl] trimethyl ammonium chloride (DMC) were used as fluoromonomer and cationic monomer, respectively. The structure and composition of copolymer were characterized by Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). Thermal stability of copolymer latex film was investigated by thermogravimetic analysis (TGA). The relationships of polymerization conditions between the conversion and coagulation ratio were discussed in detail and the optimal polymerization condition was identified. The water and oil repellency performance of perfluoralkyl acrylate copolymer latices applied to textiles is significantly investigated. Increasing the FEA amount in the emulsion will lead to increase in the contact angle and water and oil repellency on cotton fabrics. When the FEA dosage was 3.9%, the static contact angles of water and liquid paraffin on the surface of cotton fabrics treated were 142.5° and 126.5°, respectively.

Abstract

Background: The SF-36 as a generic instrument has been used widely to evaluate health-related quality of life in both healthy subjects and groups of patients. However, no data can be found on its performance in patients with Graves’ disease. Hence, this study aimed to assess the reliability, validity, and responsiveness of the SF-36 in a Chinese population of patients with Graves’ disease.

Methods: A total of 325 patients with Graves’ disease completed interviews that included the SF-36. Internal consistency was measured by Cronbach’s α and item-scale correlations. The validity of the SF-36 was studied by means of factor analysis and the association of this scale with sociodemographic and clinical variables. A standardized response mean was used to assess the responsiveness of the SF-36 to change.

Results: Cronbach’s α coefficients surpassed the 0.70 criteria for seven subscales and 0.63 for the SF subscale indicating good internal consistency. The correlation coefficients between items and the remainder of the same subscale ranged from 0.51 to 0.96, which were all higher than with other subscales. A principal components factor analysis with varimax rotation identified eight factors. Hamilton Anxiety Rating Scale (HARS) scores correlated negatively to scores at the physical functioning, general health, social functioning, vitality, and role limitations due to emotional problems SF-36 subscales, while HARS scores correlated negatively only to scores on the mental health SF-36 subscale. No correlations were found between SF-36 scores and the levels of thyroid hormones. Responsiveness to improvements in health status was acceptable overall (standardized response means 0.33-0.88).

Conclusion: The Chinese (mainland) version of the SF-36 is a suitable instrument that can be used in patients with Graves’ disease.

Abstract

Gypsum is a mineral that commonly precipitates in hydrothermal environments. This study reports the electron microscopic analyses of gypsum morphologies and crystal sizes found in hot springs on the Kamchatka Peninsula, Russia, and compares these analyses with gypsum morphologies of hydrothermal genesis found in Lower Cambrian black shale. In sediments of the Kamchatka hot springs, we observed prismatic, prismatic pseudo-hexagonal, fibrous, tubular, lenticular and twinned gypsum crystals, with crystal sizes ranging from <200 nm to >200 μm. The coexistence of diverse crystal habits of gypsum implies a constant interaction between hot spring geochemistry and the metabolisms of the microbial community. The crystallization of Ca- and Ba-sulfates in the black shale of the Lower Cambrian, which shows similar but less varied morphology, was influenced by post-depositional hydrothermal fluids. The partial replacement of pyrite by sulfates in a situation coexisting with rich biomass deposits and animal fossils indicates limited modification of the sedimentary records by biological materials. If the gypsum precipitated on Mars underwent similar interactions between microbial communities and their geochemical environments, the resulting crystal habits could be preserved even better than those on Earth due to the weak geodynamics prevailing on Mars throughout its evolutionary history.

Abstract

Cinnamomin, a new type II ribosomeinactivating protein (RIP), was found to be able to induce the release of calcein loaded in lecithin small unilamellar vesicles and the fusion or aggregation of the lecithin liposomes. Such induction could be promoted several fold by a pH 5.0 environment, a condition similar to that in endocytic vesicles. Lowering the pH from 7.5 to 5.0 evoked conformational changes of cinnamomin and unmasked its hydrophobic areas, including the exposure of 1-anilino-8-naphthalenesulfonate (1,8-ANS) binding sites of the molecule. Some tryptophan residues with affinity to acrylamide were demonstrated to participate in the lipidprotein interaction. The pH dependent fusogenicity of type II RIP might suggest its in vivo function as a fusogen to exert its cytotoxicity.

Abstract

This paper researches the stiffness of the cast iron specimens with unilateral crack and bilateral crack on the basis of the uniaxial tensile simulation, and the main conclusions are as follows: the stiffness of the model shows nonlinear decline with the crack propagation; the stiffness decreases very slowly in initial stage and then gets fast with the crack propagation; the stiffness is more affected with the unilateral crack than the center crack when the length of crack is equal; the greater angle between the unilateral crack and the horizontal direction, the higher the stiffness; with the increase of the longitudinal spacing of bilateral crack, the model stiffness reduces and is greatly influenced.

Abstract

Predicting genes likely to be involved in human diseases is an important task in bioinformatics field. Nowadays, the accumulation of human protein-protein interactions (PPIs) data provides us an unprecedented opportunity to gain insight into human diseases. In this paper, we adopt the topological similarity in human protein-protein interaction network to predict disease-related genes. As a computational algorithm to speed up the identification of disease-related genes, the topological similarity has substantial advantages over previous topology-based algorithms. First of all, it provides a global measurement of similarity between two vertices. Secondly, quantity which can measure new topological feature has been integrated into the notion of topological similarity. Our method is specially designed for predicting disease-related genes of single disease-gene family. The proposed method is applied to human protein-protein interaction and hepatocellular carcinoma (HCC) data. The results show a significant enrichment of disease-related genes that are characterized by higher topological similarity than other genes.