186 research outputs found

    Comparison of quinolone and β-lactam resistance among Escherichia coli strains isolated from urinary tract infections

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    The growing frequency of antibiotic resistances is now a universal problem. Increasing resistance to new generations of β-lactam and quinolone antibiotics in multidrug- resistant Enterobacteriaceae isolates is considered an emergency health issue worldwide. The aim of this study was to evaluate plasmid-mediated quinolone resistance genes in ESBL-producing Escherichia coli isolated from urinary tract infections (UTIs). In our study ESBL- producing isolates were assessed by screening methods. After determination of antimicrobial susceptibility, detection of ESBLs and quinolone resistance genes was performed. A total of 97 ESBL-producing E. coli were determined. The blaTEM, blaSHV and blaCTX-M genes were detected in 90 isolates. The blaTEM was the most frequent- ly detected gene (46.4), followed by blaSHV (31.9) and blaCTX-M (14.4). The most prevalent quinolone resistance gene among ESBL-producing isolates was oqxAB which found in 67 isolates (69.1). The frequencies of the aac(6�)-Ib-cr, qnr and qepA were 65 (67), 8 (8.2) and 6 (6.2), respectively. Our data indicate that the prevalence of plasmid-mediated quinolone resistance genes in ESBL-positive isolates is increasing. The co-dissemination of PMQR and ESBL genes among E. coli isolates can be considered a threat to public health. Therefore, prescription of antibiotics against infectious disease should be managed carefully. © 2016, International Society of Musculoskeletal and Neuronal Interactions. All rights reserved

    Liver transplant recipients quality of life instrument: Development and psychometric testing

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    Background: Liver transplantation is a life-saving intervention for many patients with end-stage liver disease. In the past, evaluation of successful liver transplantation was based on patients' survival rate. However, in recent years this evaluation has been based on patients' quality of life. Various instruments have been developed to evaluate patients' quality of life. Nonetheless, scholars still believe that it is crucial to develop a standardized and disease specific instrument for evaluating the quality of life in liver transplant recipients. Objectives: The aim of this paper was to describe the development and psychometric testing process of a quality of life instrument specific to liver transplant recipients. Materials and Methods: Initial items of this instrument were extracted from a conventional content analysis study, and then were completed with findings of related international literature. The face validity was assessed by interviewing with four liver transplant recipients, and the content validity was evaluated by eleven experts in the field of transplantation. The construct validity was achieved by involving 250 liver transplant recipients through exploratory factor analysis method, and reliability was calculated by Cronbach's alpha. Results: Three main factors with 40 items were extracted from the exploratory factor analysis: Health Satisfaction, Concerns, and Complications. Reliability of the instrument was confirmed (alpha = 0.922). Conclusions: Given the special considerations regarding liver transplant recipients, this questionnaire is more accurate in evaluating the success of liver transplantation. © 2013, Kowsar Corp.; Licensee Kowsar Ltd

    Robust PID based indirect-type iterative learning control for batch processes with time-varying uncertainties

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    ased on the proportional-integral-derivative (PID) control structure widely used in engineering applications, a robust indirect-type iterative learning control (ILC) method is proposed for industrial batch processes subject to time-varying uncertainties. An important merit is that the proposed ILC design is independent of the PID tuning that aims primarily to hold robust stability of the closed-loop system, owing to the fact that the ILC updating law is implemented through adjusting the setpoint of the closed-loop PID control structure plus a feedforward control to the plant input from batch to batch. According to the robust H infinity control objective, a robust discrete-time PID tuning algorithm is given in terms of the plant state-space model description to accommodate for time-varying process uncertainties. For the batchwise direction, a robust ILC updating law is developed based on the two-dimensional (2D) control system theory. Only measured output errors of current and previous cycles are used to implement the proposed ILC scheme for the convenience of practical application. An illustrative example from the literature is adopted to demonstrate the effectiveness and merits of the proposed ILC method

    3D-printed membrane for guided tissue regeneration

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    Three-dimensional (3D) printing is currently being intensely studied for a diverse set of applications, including the development of bioengineered tissues, as well as the production of functional biomedical materials and devices for dental and orthopedic applications. The aim of this study was to develop and characterize a 3D-printed hybrid construct that can be potentially suitable for guided tissue regeneration (GTR). For this purpose, the rheology analyses have been performed on different bioinks and a specific solution comprising 8% gelatin, 2% elastin and 0.5% sodium hyaluronate has been selected as the most suitable composition for printing a structured membrane for GTR application. Each membrane is composed of 6 layers with strand angles from the first layer to the last layer of 45, 135, 0, 90, 0 and 90°. Confirmed by 3D Laser Measuring imaging, the membrane has small pores on one side and large pores on the other to be able to accommodate different cells like osteoblasts, fibroblasts and keratinocytes on different sides. The ultimate cross-linked product is a 150 μm thick flexible and bendable membrane with easy surgical handling. Static and dynamic mechanical testing revealed static tensile modules of 1.95 ± 0.55 MPa and a dynamic tensile storage modulus of 314 ± 50 kPa. Through seeding the membranes with fibroblast and keratinocyte cells, the results of in vitro tests, including histological analysis, tissue viability examinations and DAPI staining, indicated that the membrane has desirable in vitro biocompatibility. The membrane has demonstrated the barrier function of a GTR membrane by thorough separation of the oral epithelial layer from the underlying tissues. In conclusion, we have characterized a biocompatible and bio-resorbable 3D-printed structured gelatin/elastin/sodium hyaluronate membrane with optimal biostability, mechanical strength and surgical handling characteristics in terms of suturability for potential application in GTR procedures

    Cosmological observations in non-local F(R)F(R) cosmology

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    In this article in a generalization of our previous work, we investigate the dynamics of the non-local F(R)F(R) gravity after casting it into local form. The non-singular bouncing behavior and quintom model of dark energy are achieved without involving negative kinetic energy fields. Two cosmological tests are performed to constrain the model parameters. In case of phantom crossing the distance modulus predicted by the model best-fits the observational data. In comparison with the CPL parametrization for drift velocity, the model in some redshift intervals is in good agreement with the data.Comment: 12 pages, 7 figures, will be published in Astrophysics and space scienc

    Molecular Trajectories Leading to the Alternative Fates of Duplicate Genes

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    Gene duplication generates extra gene copies in which mutations can accumulate without risking the function of pre-existing genes. Such mutations modify duplicates and contribute to evolutionary novelties. However, the vast majority of duplicates appear to be short-lived and experience duplicate silencing within a few million years. Little is known about the molecular mechanisms leading to these alternative fates. Here we delineate differing molecular trajectories of a relatively recent duplication event between humans and chimpanzees by investigating molecular properties of a single duplicate: DNA sequences, gene expression and promoter activities. The inverted duplication of the Glutathione S-transferase Theta 2 (GSTT2) gene had occurred at least 7 million years ago in the common ancestor of African great apes and is preserved in chimpanzees (Pan troglodytes), whereas a deletion polymorphism is prevalent in humans. The alternative fates are associated with expression divergence between these species, and reduced expression in humans is regulated by silencing mutations that have been propagated between duplicates by gene conversion. In contrast, selective constraint preserved duplicate divergence in chimpanzees. The difference in evolutionary processes left a unique DNA footprint in which dying duplicates are significantly more similar to each other (99.4%) than preserved ones. Such molecular trajectories could provide insights for the mechanisms underlying duplicate life and death in extant genomes

    Genome sequencing analysis identifies new loci associated with Lewy body dementia and provides insights into its genetic architecture

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    The genetic basis of Lewy body dementia (LBD) is not well understood. Here, we performed whole-genome sequencing in large cohorts of LBD cases and neurologically healthy controls to study the genetic architecture of this understudied form of dementia, and to generate a resource for the scientific community. Genome-wide association analysis identified five independent risk loci, whereas genome-wide gene-aggregation tests implicated mutations in the gene GBA. Genetic risk scores demonstrate that LBD shares risk profiles and pathways with Alzheimer's disease and Parkinson's disease, providing a deeper molecular understanding of the complex genetic architecture of this age-related neurodegenerative condition
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