1,721 research outputs found

    Effect of Bone Marrow-derived Mesenchymal Stem Cells and Umbilical Cord Blood-CD34+ cells on Experimental Rat liver Fibrosis

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    Background and Objective: Liver disease is one of the major causes of death in many countries. Hence, the development of effective therapies for liver fibrosis is a major aim of medical research. So this study was designed to investigate the therapeutical role of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) transplantation in the experimental rat liver fibrosis. Design and Method: Bone marrow-derived MSCs were isolated from femoral and tibial bones of male albino rats, then were grown and propagated in culture for 2 weeks and were characterized morphologically and by detection of CD29 by real time-PCR. Human umbilical cord blood cells were obtained after full-term caesarean delivery from healthy donors after written informed consent. Low-density mononuclear cells were separated over Ficoll- Paque (Gibco-Invitrogen, Grand Island, NY), and then CD34+ HSC was isolated using a magnetic cell sorter (MiniMACS; Miltenyi Biotec, Bergisch Gladbach, Germany). The cells were then infused intraperitoneally in rats that received CCl4 injection to induce liver fibrosis. Rats were divided into 4 groups: control, CCl4, CCl4 plus MSC, and CCl4 plus CD34+. Liver tissue was examined histopathologically for all groups. The expression of collagen I and metalloproteinase-2 genes as a marker of liver fibrosis was measured by real time RT- PCR. Results: The results of the present study showed that both MSCs and CD34+ have a significant antifibrotic effect as evidenced by the significant decrease in liver collagen gene expression as well as the decrease in MMP-2 (p < 0.05) compared to the CCl4 group

    OPUCEM: A Library with Error Checking Mechanism for Computing Oblique Parameters

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    After a brief review of the electroweak radiative corrections to gauge-boson self-energies, otherwise known as the direct and oblique corrections, a tool for calculation of the oblique parameters is presented. This tool, named OPUCEM, brings together formulas from multiple physics models and provides an error-checking machinery to improve reliability of numerical results. It also sets a novel example for an "open-formula" concept, which is an attempt to improve the reliability and reproducibility of computations in scientific publications by encouraging the authors to open-source their numerical calculation programs. Finally, we demonstrate the use of OPUCEM in two detailed case studies related to the fourth Standard Model family. The first is a generic fourth family study to find relations between the parameters compatible with the EW precision data and the second is the particular study of the Flavor Democracy predictions for both Dirac and Majorana-type neutrinos.Comment: 10 pages, 19 figures, section 3 and 4 reviewed, results unchanged, typo correction

    Inkjet printing of polyimide insulators for the 3D printing of dielectric materials for microelectronic applications

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    In this article, we report the first continuous fabrication of inkjet-printed polyimide films, which were used as insulating layers for the production of capacitors. The polyimide ink was prepared from its precursor poly(amic) acid, and directly printed on to a hot substrate (at around 160 °C) to initialize a rapid thermal imidization. By carefully adjusting the substrate temperature, droplet spacing, droplet velocity, and other printing parameters, polyimide films with good surface morphologies were printed between two conducting layers to fabricate capacitors. In this work, the highest capacitance value, 2.82 ± 0.64 nF, was achieved by capacitors (10 mm × 10 mm) with polyimide insulating layers thinner than 1 ÎŒm, suggesting that the polyimide inkjet printing approach is an efficient way for producing dielectric components of microelectronic devices. © 2016 The Authors Journal of Applied Polymer Science Published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43361

    A machine-learning approach to negation and speculation detection for sentiment analysis

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    Recognizing negative and speculative information is highly relevant for sentiment analysis. This paper presents a machine-learning approach to automatically detect this kind of information in the review domain. The resulting system works in two steps: in the first pass, negation/speculation cues are identified, and in the second phase the full scope of these cues is determined. The system is trained and evaluated on the Simon Fraser University Review corpus, which is extensively used in opinion mining. The results show how the proposed method outstrips the baseline by as much as roughly 20% in the negation cue detection and around 13% in the scope recognition, both in terms of F1. In speculation, the performance obtained in the cue prediction phase is close to that obtained by a human rater carrying out the same task. In the scope detection, the results are also promising and represent a substantial improvement on the baseline (up by roughly 10%). A detailed error analysis is also provided. The extrinsic evaluation shows that the correct identification of cues and scopes is vital for the task of sentiment analysis.Maite Taboada from the Natural Sciences and Engineering Research Council of Canada (Discovery Grant 261104- 2008). This work was partly funded by the Spanish Ministry of Education and Science (TIN2009-14057-C03-03 Project) and the Andalusian Ministry of Economy, Innovation and Science (TIC 07629 and TIC 07684 Projects)

    A global perspective on the challenges and opportunities in learning about rheumatic and musculoskeletal diseases in undergraduate medical education : White paper by the World Forum on Rheumatic and Musculoskeletal Diseases (WFRMD).

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    Rheumatic and musculoskeletal diseases (RMDs) encompass a spectrum of degenerative, inflammatory conditions predominantly affecting the joints. They are a leading cause of disability worldwide and an enormous socioeconomic burden. However, worldwide deficiencies in adult and paediatric RMD knowledge among medical school graduates and primary care physicians (PCPs) persist. In October 2017, the World Forum on Rheumatic and Musculoskeletal Diseases (WFRMD), an international think tank of RMD and related experts, met to discuss key challenges and opportunities in undergraduate RMD education. Topics included needs analysis, curriculum content, interprofessional education, teaching and learning methods, implementation, assessment and course evaluation and professional formation/career development, which formed a framework for this white paper. We highlight a need for all medical graduates to attain a basic level of RMD knowledge and competency to enable them to confidently diagnose, treat/manage or refer patients. The importance of attracting more medical students to a career in rheumatology, and the indisputable value of integrated, multidisciplinary and multiprofessional care are also discussed. We conclude that RMD teaching for the future will need to address what is being taught, but also where, why and to whom, to ensure that healthcare providers deliver the best patient care possible in their local settin

    Analysis of the self-healing capability of thermoplastic elastomer capsules in a polymeric beam structure based on strain energy release behaviour during crack growth

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    The objective of this study was to investigate the elastic and plastic responses of 3D-printed thermoplastic elastomer (TPE) beams under various bending loads. The study also aimed to develop a self-healing mechanism using origami TPE capsules embedded within an ABS structure. These cross-shaped capsules have the ability to be either folded or elastically deformed. When a crack occurs in the ABS structure, the strain is released, causing the TPE capsule to unfold along the crack direction, thereby enhancing the crack resistance of the ABS structure. The enhanced ability to resist cracks was confirmed through a delamination test on a double cantilever specimen subjected to quasi-static load conditions. Consistent test outcomes highlighted how the self-healing process influenced the development of structural cracks. These results indicate that the suggested self-healing mechanism has the potential to be a unique addition to current methods, which mostly rely on external healing agents

    Modal response of hybrid raster orientation on material extrusion printed acrylonitrile butadiene styrene and polyethylene terephthalate glycol under thermo-mechanical loads

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    In this paper we look at Acrylonitrile Butadiene Styrene (ABS) and Polyethylene Terephthalate Glycol (PETG), chosen for their low cost, high strength and temperature resistance. This study evaluates the bending fatigue performance of Material extrusion (MEX) ABS and PETG cantilever beams and compares their properties while varying a printing parameter under thermal loads. The study, using custom building orientation angles of 90o, 45o and 60o between the layers, tested the beams at different temperatures from 30o to 50 °C. The results show the effects of the building orientations and the effects of temperature on the sample. The printing orientation, which is the same as loading, also slows the crack growth

    A Google Earth-based database management for schistosomiasis control in Zanzibar

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    Schistosomiasis remains a serious health problem in Africa. Although a strong, coordinated agenda for research on this disease has been in place for the last 50 years in Zanzibar, data storage, retrieval of survey data and management remain problem areas. We investigated the use of Google Earth (GE) in conjunction with a hand-held, global positioning system as a pilot project for managing schistosomiasis control. In this way, risk areas can be surveyed and followed up by visualizing both the distribution of human infections and that of the intermediate snail host together with environmental information. A platform with three spatial databases was created: i) Distribution of infected humans; ii) Distribution of the intermediate snail host in ponds (infected and not infected specimens); iii) Distribution of the intermediate snail host in streams (infected and non-infected specimens). The GE spatial database increased the efficiency of follow-up case treatment as well as snail control and contributed also to the discovery of previously unknown areas in need of snail control. We conclude that this platform is advantageous not only by being useful for management and visualization of spatial data, but also because it is easy to operate and available free of charge

    Tea and coffee consumption in relation to vitamin D and calcium levels in Saudi adolescents

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    Background Coffee and tea consumption was hypothesized to interact with variants of vitamin D-receptor polymorphisms, but limited evidence exists. Here we determine for the first time whether increased coffee and tea consumption affects circulating levels of 25-hydroxyvitamin D in a cohort of Saudi adolescents. Methods A total of 330 randomly selected Saudi adolescents were included. Anthropometrics were recorded and fasting blood samples were analyzed for routine analysis of fasting glucose, lipid levels, calcium, albumin and phosphorous. Frequency of coffee and tea intake was noted. 25-hydroxyvitamin D levels were measured using enzyme-linked immunosorbent assays. Results Improved lipid profiles were observed in both boys and girls, as demonstrated by increased levels of HDL-cholesterol, even after controlling for age and BMI, among those consuming 9–12 cups of coffee/week. Vitamin D levels were significantly highest among those consuming 9–12 cups of tea/week in all subjects (p-value 0.009) independent of age, gender, BMI, physical activity and sun exposure. Conclusion This study suggests a link between tea consumption and vitamin D levels in a cohort of Saudi adolescents, independent of age, BMI, gender, physical activity and sun exposure. These findings should be confirmed prospectively

    Transport and Retention of High Concentrated Nano-Fe/Cu Particles Through Highly Flow-Rated Packed Sand Column

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    The design of an efficient field-scale remediation based on the use of nanoscale zero valent iron (NZVI) requires an accurate assessment of the mobility of such particles in saturated porous media, both during injection in the subsurface (short-term mobility) and later (long-term mobility). In this study, the mobility of highly concentrated dispersions of bimetallic Fe/Cu nanoparticles (d50= 70±5 nm) in sand-packed columns (0.5 m length and 0.025 m inner diameter) was studied. In particular, the influence of flow rate (V = 5×10-4, 1×10-3, 2×10-3 m/s) and injected particle concentrations (2, 5, 8, 12 g/l) was addressed. Breakthrough curves and water pressure drop along the column, averaged effective porosity and final distribution of retained particles along the column were measured. Experimental results evidenced a good mobility of the Fe/Cu particles, with significant breakthrough in all explored experimental conditions of flow rate and C0, without requiring the addition of any stabilizing agent. Clogging phenomenon of the column and also the pore pressure variation during injection period are strongly affected by injected concentration. Clogging due to deposition of particles following a ripening dynamics was observed in particular for C0= 8 and 12 g/l. The experimental data were 23 modeled using the E-MNM1D software. The study has implications for field injection of bimetallic nanoparticles, suggesting that particular care is to be devoted when selecting injection concentration, to avoid porous medium clogging and control the radius of influenc
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