71 research outputs found

    Smoking, Green Tea Consumption, Genetic Polymorphisms in the Insulin-Like Growth Factors and Lung Cancer Risk

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    Insulin-like growth factors (IGFs) are mediators of growth hormones; they have an influence on cell proliferation and differentiation. In addition, IGF-binding protein (IGFBP)-3 could suppress the mitogenic action of IGFs. Interestingly, tea polyphenols could substantially reduce IGF1 and increase IGFBP3. In this study, we evaluated the effects of smoking, green tea consumption, as well as IGF1, IGF2, and IGFBP3 polymorphisms, on lung cancer risk. Questionnaires were administered to obtain the subjects' characteristics, including smoking habits and green tea consumption from 170 primary lung cancer cases and 340 healthy controls. Genotypes for IGF1, IGF2, and IGFBP3 were identified by polymerase chain reaction. Lung cancer cases had a higher proportion of smoking, green tea consumption of less than one cup per day, exposure to cooking fumes, and family history of lung cancer than controls. After adjusting the confounding effect, an elevated risk was observed in smokers who never drank green tea, as compared to smokers who drank green tea more than one cup per day (odds ratio (OR)β€Š=β€Š13.16, 95% confidence interval (CI)β€Š=β€Š2.96–58.51). Interaction between smoking and green tea consumption on lung cancer risk was also observed. Among green tea drinkers who drank more than one cup per day, IGF1 (CA)19/(CA)19 and (CA)19/X genotypes carriers had a significantly reduced risk of lung cancer (ORβ€Š=β€Š0.06, 95% CIβ€Š=β€Š0.01–0.44) compared with IGF1 X/X carriers. Smoking-induced pulmonary carcinogenesis could be modulated by green tea consumption and their growth factor environment

    Location and Level of Etk Expression in Neurons Are Associated with Varied Severity of Traumatic Brain Injury

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    Much recent research effort in traumatic brain injury (TBI) has been devoted to the discovery of a reliable biomarker correlating with severity of injury. Currently, no consensus has been reached regarding a representative marker for traumatic brain injury. In this study, we explored the potential of epithelial/endothelial tyrosine kinase (Etk) as a novel marker for TBI.TBI was induced in Sprague Dawley (SD) rats by controlled cortical impact. Brain tissue samples were analyzed by Western blot, Q-PCR, and immunofluorescence staining using various markers including glial fibrillary acidic protein, and epithelial/endothelial tyrosine kinase (Etk). Results show increased Etk expression with increased number and severity of impacts. Expression increased 2.36 to 7-fold relative to trauma severity. Significant upregulation of Etk appeared at 1 hour after injury. The expression level of Etk was inversely correlated with distance from injury site. Etk and trauma/inflammation related markers increased post-TBI, while other tyrosine kinases did not.The observed correlation between Etk level and the number of impacts, the severity of impact, and the time course after impact, as well as its inverse correlation with distance away from injury site, support the potential of Etk as a possible indicator of trauma severity

    Activation of an NLRP3 Inflammasome Restricts Mycobacterium kansasii Infection

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    Mycobacterium kansasii has emerged as an important nontuberculous mycobacterium pathogen, whose incidence and prevalence have been increasing in the last decade. M. kansasii can cause pulmonary tuberculosis clinically and radiographically indistinguishable from that caused by Mycobacterium tuberculosis infection. Unlike the widely-studied M. tuberculosis, little is known about the innate immune response against M. kansasii infection. Although inflammasome activation plays an important role in host defense against bacterial infection, its role against atypical mycobacteria remains poorly understood. In this report, the role of inflammasome activity in THP-1 macrophages against M. kansasii infection was studied. Results indicated that viable, but not heat-killed, M. kansasii induced caspase-1-dependent IL-1Ξ² secretion in macrophages. The underlying mechanism was found to be through activation of an inflammasome containing the NLR (Nod-like receptor) family member NLRP3 and the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD). Further, potassium efflux, lysosomal acidification, ROS production and cathepsin B release played a role in M. kansasii-induced inflammasome activation. Finally, the secreted IL-1Ξ² derived from caspase-1 activation was shown to restrict intracellular M. kansasii. These findings demonstrate a biological role for the NLRP3 inflammasome in host defense against M. kansasii

    Vector Quantization Based on Block Orientation

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    Vector quantization (VQ) is an eective method of data compression. Compared with other image compression techniques, VQ has a high compression ratio and a simple and low computation complexity. So VQ has a good performance in image compression. However, VQ needs much time in the encoding phase. For keeping high quality of image, VQ needs full searching to nd the closest codeword in the encoding phase. In this paper, we propose a fast algorithm to reduce the encoding time in VQ. This algorithm is based on the block orientation. By the experiments, our algorithm need less time in the encoding phase, and the quality is comparable with the VQ with the full searching encoding in the same compression ratio

    A Derivation of Factors Influencing the Diffusion and Adoption of an Open Source Learning Platform

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    During the past two decades, open source learning platforms (OSLPs) have become a dominant part of modern education. OSLPs are free for usage and customization—unlike proprietary software restricted by copyright licenses. By utilizing OSLPs, users can download and use the source code, write new features, fix bugs, improve performances, or learn from others how specific problems can be solved. Albeit dominant, the frequency of usage and motivation of OSLPs by students is not high; however, there has been very little research about this, and the problem is significant. Therefore, this research aimed to derive the factors that affect the adoption and diffusion of OSLPs. The factors on the diffusion and adoption were defined based on the innovation diffusion theory (IDT) and the technology acceptance model (TAM), where the integrated theoretical framework is called the IDT-TAM. Partial Least Square structural equation modeling was used to confirm the hypothesized IDT-TAM. An empirical study was based on the sample data collected from 340 Taiwanese technical university students to demonstrate the feasibility of the analytical framework and derive the factors related to the adoption and diffusion of the OSLP for students. Based on the results of the empirical study, through the mediation of perceived attitude (PA) and perceived usefulness (PU), trialability (TL), observability (OS), ease of use (EU), and relative advantage (RA) are the factors most related to the diffusion and acceptance of the OSLP innovations. The analytical results can serve as the basis for the design, development, and enhancement of acceptance and diffusion of OSLP

    A Derivation of Factors Influencing the Innovation Diffusion of the OpenStreetMap in STEM Education

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    Geographic information is a confluence of knowledge from spatial science, information technologies, engineering, and mathematics, etc. Effective spatial training can enhance achievement in science, technology, engineering, and mathematics (STEM) education. Therefore, the geographic information system (GIS) plays a daily role in modern STEM education. Volunteered Geographical Information (VGI) is characterized by the openness of the geographic information being generated and accumulated by volunteers. Within the VGI sphere, OpenStreetMap (OSM) is one of the most well-known VGI due to its openness, flexibility, cost-effectiveness, and web-based mapping capability, making it one of the best alternatives for use as the mapping application for STEM education. However, very few or no prior works have investigated the factors influencing the innovation diffusion of OSM in STEM education. Therefore, to fill this gap, this work aims to investigate these factors. To achieve this purpose, the authors have defined an analytic framework based on innovation diffusion theory (IDT) and the technology acceptance model (TAM). The factors influencing students’ acceptance and intention to continue using and diffusing OSM in STEM education will be investigated. Partial least squares structural equation modeling (PLS-SEM) was used to confirm the hypothesized IDT–TAM integrated model. An empirical study based on sample data collected from 145 Taiwanese undergraduate and graduate students from engineering-related institutes was used to demonstrate the feasibility of the proposed analytic framework and to derive the factors related to the adoption and diffusion of OSM in STEM education. The proposed theoretical framework forged in this study was proven to be successful. Based on the empirical study results, ease of use, observability, and compatibility are the most influential factors in OSM diffusion. Therefore, activities that enhance the ease of use, observability, and compatibility of OSM should be emphasized so that STEM students’ perception of the usefulness of the technology and their perceived attitude towards it leads to the intention to continue the use of OSM. The analytic results can serve as a foundation for the design, development, and accelerated adoption and diffusion of OSM in STEM education

    The Mechanism of ACV Synthetase

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