191 research outputs found

    Design process of the nanofluid injection mechanism in nuclear power plants

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    Nanofluids, which are engineered suspensions of nanoparticles in a solvent such as water, have been found to show enhanced coolant properties such as higher critical heat flux and surface wettability at modest concentrations, which is a useful characteristic in nuclear power plants (NPPs). This study attempted to provide an example of engineering applications in NPPs using nanofluid technology. From these motivations, the conceptual designs of the emergency core cooling systems (ECCSs) assisted by nanofluid injection mechanism were proposed after following a design framework to develop complex engineering systems. We focused on the analysis of functional requirements for integrating the conventional ECCSs and nanofluid injection mechanism without loss of performance and reliability. Three candidates of nanofluid-engineered ECCS proposed in previous researches were investigated by applying axiomatic design (AD) in the manner of reverse engineering and it enabled to identify the compatibility of functional requirements and potential design vulnerabilities. The methods to enhance such vulnerabilities were referred from TRIZ and concretized for the ECCS of the Korean nuclear power plant. The results show a method to decouple the ECCS designs with the installation of a separate nanofluids injection tank adjacent to the safety injection tanks such that a low pH environment for nanofluids can be maintained at atmospheric pressure which is favorable for their injection in passive manner

    A Collaborative Molecular Modeling Environment Using a Virtual Tunneling Service

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    Collaborative researches of three-dimensional molecular modeling can be limited by different time zones and locations. A networked virtual environment can be utilized to overcome the problem caused by the temporal and spatial differences. However, traditional approaches did not sufficiently consider integration of different computing environments, which were characterized by types of applications, roles of users, and so on. We propose a collaborative molecular modeling environment to integrate different molecule modeling systems using a virtual tunneling service. We integrated Co-Coot, which is a collaborative crystallographic object-oriented toolkit, with VRMMS, which is a virtual reality molecular modeling system, through a collaborative tunneling system. The proposed system showed reliable quantitative and qualitative results through pilot experiments

    Spermidine-induced recovery of human dermal structure and barrier function by skin microbiome.

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    An unbalanced microbial ecosystem on the human skin is closely related to skin diseases and has been associated with inflammation and immune responses. However, little is known about the role of the skin microbiome on skin aging. Here, we report that the Streptococcus species improved the skin structure and barrier function, thereby contributing to anti-aging. Metagenomic analyses showed the abundance of Streptococcus in younger individuals or those having more elastic skin. Particularly, we isolated Streptococcus pneumoniae, Streptococcus infantis, and Streptococcus thermophilus from face of young individuals. Treatment with secretions of S. pneumoniae and S. infantis induced the expression of genes associated with the formation of skin structure and the skin barrier function in human skin cells. The application of culture supernatant including Streptococcal secretions on human skin showed marked improvements on skin phenotypes such as elasticity, hydration, and desquamation. Gene Ontology analysis revealed overlaps in spermidine biosynthetic and glycogen biosynthetic processes. Streptococcus-secreted spermidine contributed to the recovery of skin structure and barrier function through the upregulation of collagen and lipid synthesis in aged cells. Overall, our data suggest the role of skin microbiome into anti-aging and clinical applications

    Comparison of Visceral Fat and Liver Fat as Risk Factors of Metabolic Syndrome

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    The principal objective of this study was to determine whether visceral fat or liver fat is a more relevant risk factor for metabolic syndrome. A total of 98 subjects aged 18-65 yr, who visited a health promotion center in a university hospital, were enrolled in this study. Metabolic syndrome was diagnosed based on the modified National Cholesterol Education Program's Adult Treatment Panel III report (NCEP-ATPIII) criteria. We defined the visceral obesity as a visceral fat area of ≥ 100 cm2 which was acquired by CT at the L4-5 level. To evaluate fatty liver, we applied a liver-to-spleen attenuation ratio ≤ 1.1 as measured by CT at the T12 level. We employed binary logistic regression models that used the presence or absence of metabolic syndrome as a dependent variable and age, sex, and the presence or absence of visceral obesity and fatty liver as independent variables. Visceral obesity was not found to be an independent variable as a risk factor of metabolic syndrome (odds ratio 2.7; 95% confidence interval 0.55-13.30), but fatty liver was found to be significant in this model (odds ratio 71.3; 95% CI 13.04-389.53). Our study suggests that liver fat may be a more important risk factor than visceral fat in terms of its association with metabolic syndrome

    Comparison of Predictability of Cardiovascular Events between Each Metabolic Component in Patients with Metabolic Syndrome Based on the Revised National Cholesterol Education Program Criteria

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    PURPOSE: The prevalence of metabolic syndrome (MetS) generally varies depending on its diagnostic definition, and many different definitions inevitably lead to substantial confusion and lack of comparability between studies. Despite extensive research, there is still no gold standard for the definition of MetS, which continues to be a matter of debate. In this study, we investigate whether and to what extent its individual components are related to the risk of cardiovascular disease (CVD) in Korean population. MATERIALS AND METHODS: We used data from the 2005 Korea National Health and Nutrition Examination Survey, which is a nationally representative survey of the noninstitutionalized civilian population. The study sample consisted of 1,406 Korean adults (587 men, 819 women) who were diagnosed with MetS based on the revised National Cholesterol Education Program (NCEP) criteria. Central obesity is defined as a waist circumference cutoff point reported in Asia-Pacific criteria for obesity based on waist circumference by the World Health Organization. CVD was defined as presence of stroke, myocardial infarction, or angina pectoris on a medical history questionnaire. RESULTS: The CVD prevalence among the subjects was 6.8% for men and 8.6% for women. Besides age, the components of MetS showing a significant difference in the number of CVD events were high fasting glucose (FG) in men and high blood pressure (BP) and high FG in women. After adjusting for gender and age, high FG was shown to yield a significant difference (odds ratio: unadjusted 2.08, adjusted 1.81), alone among all MetS components. However, after adjusting for only age, no significant difference was found. CONCLUSION: Fasting glucose level is the highest predicting factor for CVD in Korean patients with MetS based on the revised NECP definitionope

    Apolipoprotein J is a hepatokine regulating muscle glucose metabolism and insulin sensitivity

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    Funding Information: This work was supported by grants from the National Institutes of Health (R01DK111529 and R01DK106076 to Y.-B.K.) and in part by Merit Review Award (I01CX00635) from the United States Department of Veterans Affairs Clinical Sciences Research and Development Service (R.R.H.), grants from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2018R1D1A1B07049123 to J.A.S. and 2017R1A6A3A03003298 to W.-M.Y.), a grant from the Korean Diabetes Association (2017S-2 to J.A.S.), and a grant from Korea University (K1813091 to J.A.S.). The contents do not represent the views of the U.S. Department of Veterans Affairs or the United States Government. The Animal Metabolic Physiology Core (P30 DK057521 Barbara Kahn) performed in vivo glucose uptake. M.-C.K. is a recipient of a postdoctoral fellowship award from the American Diabetes Association (1-17-PDF-146), I.S.L. is a recipient of FCT fellowship from Portugal (SFRH/BD/71021/2010), and L.P.M is a recipient of São Paulo Research Foundation from Brazil (FAPESP 2013/ 14149-6). We would like to thank Barbara Kahn, Tony Hollenberg, and Terry Flier for helpful discussions, Odile Peroni for technical assistance on in vivo glucose uptake, Amira Klip for the C2C12-myc-Glut4 cell line, Sungman Cho for glucose uptake assays, Jin Sung Park for VLDL-secretion, Wendy Li for Immunofluorescent analysis, Zoltan Arany for myogenin-Cre transgenic mice, Inkyu Lee for ApoJ adenovirus, and Min Bon Hong for ApoJ recombinant protein. Publisher Copyright: © 2020, The Author(s).Crosstalk between liver and skeletal muscle is vital for glucose homeostasis. Hepatokines, liver-derived proteins that play an important role in regulating muscle metabolism, are important to this communication. Here we identify apolipoprotein J (ApoJ) as a novel hepatokine targeting muscle glucose metabolism and insulin sensitivity through a low-density lipoprotein receptor-related protein-2 (LRP2)-dependent mechanism, coupled with the insulin receptor (IR) signaling cascade. In muscle, LRP2 is necessary for insulin-dependent IR internalization, an initial trigger for insulin signaling, that is crucial in regulating downstream signaling and glucose uptake. Of physiologic significance, deletion of hepatic ApoJ or muscle LRP2 causes insulin resistance and glucose intolerance. In patients with polycystic ovary syndrome and insulin resistance, pioglitazone-induced improvement of insulin action is associated with an increase in muscle ApoJ and LRP2 expression. Thus, the ApoJ-LRP2 axis is a novel endocrine circuit that is central to the maintenance of normal glucose homeostasis and insulin sensitivity.publishersversionpublishe

    Associated Factors of Quality of Life in First-Episode Schizophrenia Patients

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    OBJECTIVE: Improving quality of life is an important goal in the treatment of schizophrenia. In previous research, quality of life has been reported to be compromised in patients with schizophrenia. The aim of this study was to investigate whether quality of life may be impaired in first-episode schizophrenia patients and to identify the associated factors of quality of life in first-episode schizophrenia. METHODS: Forty-eight patients with first-episode schizophrenia and 20 normal controls were recruited. Quality of life was measured by using the Quality of Life scale (QLS). General and social self-efficacy, perceived social support were measured by using the self-report scales. The clinical assessments and comprehensive neurocognitive battery were also administered. RESULTS: First-episode group showed significantly decreased QLS total and QLS subscale scores compared to normal controls group. The key associated factors of quality of life in patients with first-episode schizophrenia were the negative symptoms and social self-efficacy. CONCLUSION: This finding implies that compromised quality of life may be already emerged in schizophrenia in their first-episode and the psychosocial interventions should be targeting the negative symptoms and the psychosocial protective factors including self-efficacy in addition to simply ameliorating the positive symptoms to foster social reintegration and recovery of first-episode patients.ope

    Dlx5 specifically regulates Runx2 type II expression by binding to homeodomain-response elements in the Runx2 distal promoter

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    Two major isoforms of the Runx2 gene are expressed by alternative promoter usage: Runx2 type I (Runx2-I) is derived from the proximal promoter (P2), and Runx2 type II (Runx2-II) is produced by the distal promoter (P1). Our previous results indicate that Dlx5 mediates BMP-2-induced Runx2 expression and osteoblast differentiation (Lee, M.-H., Kim, Y-J., Kim, H-J., Park, H-D., Kang, A-R., Kyung, H.-M., Sung, J-H., Wozney, J. M., Kim, H-J., and Ryoo, H-M. (2003) J. Biol. Chem. 278, 34387–34394). However, little is known of the molecular mechanisms by which Dlx5 up-regulates Runx2 expression in BMP-2 signaling. Here, Runx2-II expression was found to be specifically stimulated by BMP-2 treatment or by Dlx5 overexpression. In addition, BMP-2, Dlx5, and Runx2-II were found to be expressed in osteogenic fronts and parietal bones of the developing cranial vault and Runx2-I and Msx2 in the sutural mesenchyme. Furthermore, Runx2 P1 promoter activity was strongly stimulated by Dlx5 overexpression, whereas Runx2 P2 promoter activity was not. Runx2 P1 promoter deletion analysis indicated that the Dlx5-specific response is due to sequences between 756 and 342 bp of the P1 promoter, where three Dlx5-response elements are located. Dlx5 responsiveness to these elements was confirmed by gel mobility shift assay and site-directed mutagenesis. Moreover, Msx2 specifically suppressed the Runx2 P1 promoter, and the responsible region overlaps with that recognized by Dlx5. In summary, Dlx5 specifically transactivates the Runx2 P1 promoter, and its action on the P1 promoter is antagonized by Msx2.This work was supported by Grants 01-PJ1-PG1-01CH08-0001 and 01-PJ3-PG6- 01GN11-0002 from the Korea Health 21 R&D Project, Ministry of Health and Welfare, Republic of Korea. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact
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