301 research outputs found

    Feasibility of Using Phase Change Materials to Control the Heat of Hydration in Massive Concrete Structures

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    This paper presents experimental results that can be applied to select a possible phase change material (PCM), such as a latent heat material (LHM), to control the hydration heat in mass concrete structures. Five experimental tests (microconduction, simplified adiabatic temperature rise, heat, and compressive strength tests) were conducted to select the most desirable LHM out of seven types of inorganic PCM used in cement mortar and to determine the most suitable mix design. The results of these experimental tests were used to assess the feasibility of using PCM to reduce hydration heat in mass concrete that was examined. The experimental results show that cement mortar containing barium- [Ba(OH)2·8H2O] based PCM has the lowest amount of total hydration heat of the cement pastes. The barium-based PCM provides good latent heat properties that help to prevent volume change and microcracks caused by thermal stress in mass concrete

    Association between serum alanine aminotransferase level and obesity indices in Korean adolescents

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    PurposeTo analyze the correlation between serum alanine aminotransferase (ALT) and obesity indices including body mass index (BMI), body fat percentage (BFP), total fat mass (FM), truncal fat mass (TFM), waist circumference (WC), and waist-to-height ratio (WHtR) in Korean adolescents.MethodsThis was a cross-sectional study based on data derived from the 2010-2011 Korean National Health and Nutrition Examination Surveys (KNHANES). Subjects were Korean adolescents aged 10-18 years (871 total; 475 boys and 396 girls) who participated in KNHANES.ResultsIn both sexes, BMI, FM, TFM, WC, and WHtR were higher when ALT levels were in the 4th quartile. In boys, there was a significant positive correlation between ALT level and BMI, BFP, FM, TFM, WC, and WHtR (r=0.55, P<0.0001 for BMI; r=0.52, P<0.0001 for BFP; r=0.58, P<0.0001 for FM; r=0.61, P<0.0001 for TFM; and r=0.56, P<0.0001 for WC; r=0.62, P<0.0001 for WHtR), and the correlation coefficient was higher than that in girls.ConclusionOur results suggest a significant positive association between serum ALT level and obesity indices in male adolescents

    Alishewanella aestuarii sp. nov., isolated from tidal flat sediment, and emended description of the genus Alishewanella

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    The genus Alishewanella, proposed by Fonnesbech Strain B11 T was isolated from tidal flat sediment in Yeosu (34 u 479 260 N 127 u 349 010 E), Republic of Korea. The strain was isolated on R2A agar (Difco) followed by repeated restreaking to obtain a pure culture. The Gram reaction was determined according to the non-staining method described by T and closely related strains. Chromosomal DNA was extracted and purified using a DNA extraction kit (IntronBiotechnology). The G+C content was determined using HPLC as described by T is affiliated phylogenetically with A. fetalis; this affiliation is supported by high bootstrap values (100, 98 and 94 % by the neighbour-joining, maximum-parsimony and maximum-likelihood methods, respectively). Similarities between the 16S rRNA gene sequence of strain B11 T and those of A. fetalis CCUG 30811 T Rheinheimera aquimaris SW-353 T and Rheinheimera perlucida BA131 T were 98.3, 96.5 and 96.4 %, respectively. A DNA-DNA hybridization experiment was performed as described previously For quantitative analysis of cellular fatty acids, strain B11 T and A. fetalis CCUG 30811 T were grown under the same conditions on blood agar plates at 30 u C for 2 days. Cells were harvested and cellular fatty acids were saponified, methylated and extracted as described by the Sherlock Microbial Identification System T were C 18 : 1 v7c, C 17 : 1 v8c, summed feature 3 (C 16 : 1 v7c and/or iso-C 15 : 0 2-OH), C 16 : 0 and C 17 : 0 . Complete fatty acid compositions of the novel strain and A. fetalis CCUG 30811 T are shown in T and the type strain of A. fetalis are similar. In addition to 16S rRNA gene similarity, the major fatty acid components of strain B11 T and its temperature range for growth confirm affiliation of this strain with the genus Alishewanella

    Suppressive Effect on Lipopolysaccharide-Induced Proinflammatory Mediators by Citrus aurantium L. in Macrophage RAW 264.7 Cells via NF-κB Signal Pathway

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    Citrus fruits have been used as an edible fruit and a traditional medicine since ancient times. In particular, the peels of immature citrus fruits are used widely in traditional herbal medicine in Korea, as they are believed to contain bioactive components exerting anti-inflammatory activity. This study examined whether the crude methanol extract of Citrus aurantium L. (CME) has a suppressive effect on inducible enzymes and proinflammatory cytokines by inhibiting the NF-κB pathway in LPS-stimulated macrophage RAW 264.7 cells. The cells were pretreated with the indicated concentrations of CME (5, 10, 20, and 50 μg/mL) and then treated with LPS (1 μg/mL). The results showed that CME (10, 20, and 50 μg/mL) inhibited the LPS- (1 μg/mL) induced mRNA and protein expression of iNOS in macrophage Raw 264.7 cells. In addition, the expression of COX-2 was inhibited at the mRNA and protein levels by CME in a dose-dependent manner. The mRNA expression of proinflammatory cytokines, such as TNF-α and IL-6, were markedly reduced by CME (10, 20, and 50 μg/mL). Moreover, CME clearly suppressed the nuclear translocation of the NF-κB p65 subunits, which was correlated with its inhibitory effect on I-κB phosphorylation. These results suggest that CME has anti-inflammatory properties by modulating the expression of COX-2, iNOS, and proinflammatory cytokines, such as TNF-α and IL-6, in macrophage RAW 264.7 cells via the NF-κB pathway

    Pulmonary Complications After Hematopoietic Stem Cell Transplantation

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    Despite advanced effective prophylaxes, pulmonary complications still occur in a high proportion of all hematopoietic stem cell recipients, accounting for considerable morbidity and mortality. The aim of our study was to describe the causes, incidences and mortality rates secondary to pulmonary complications and risk factors of such complications following hematopoietic stem cell transplantation (HSCT). We reviewed the medical records of 287 patients who underwent either autologous or allogeneic HSCT for hematologic disorders from February 1996 to October 2003 at Samsung Medical Center (134 autografts, 153 allografts). The timing of pulmonary complications was divided into pre-engraftment, early and late period. The spectrum of pulmonary complications included infectious and non-infectious conditions. 73 of the 287 patients (25.4%) developed pulmonary complications. Among these patients, 40 (54.8%) and 29 (39.7%) had infectious and non-infectious conditions, respectively. The overall mortality rate from pulmonary complications was 28.8%. Allogeneic transplant, grade II-IV acute graft-versus-host disease (GVHD) and extensive chronic GVHD were the risk factors with statistical significance for pulmonary complications after HSCT. The mortality rates from pulmonary complications following HSCT were high, especially those of viral and fungal pneumonia, diffuse alveolar hemorrhage and idiopathic pneumonia syndrome

    Vaccination and Complementary and Alternative Medicine in Patients with Inflammatory Bowel Disease

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    Background/AimsVaccinations in patients with inflammatory bowel disease (IBD) are recommended to prevent infectious diseases. However, there are few reports of vaccination in IBD patients in Korea. The frequency of complementary and alternative medicine (CAM) use is high despite its uncertain effectiveness. This study aimed to identify the rates of vaccination and use of CAM in patients with IBD.MethodsA total of 219 patients attended an education session for IBD patients held at Severance Hospital on March 23, 2013. We conducted a survey on vaccination and CAM use in IBD patients; 120 patients completed the questionnaire.ResultsThe influenza vaccination rate was 44.2% and pneumococcal vaccination rate was 4.2%. Thirty-one (66%) patients were aware of the importance of vaccination. The vaccination rate was higher in patients who were aware of the importance of vaccination compared with that in patients who were unaware of the importance of vaccination (70.1% vs. 41.7%, P=0.004). The rate of CAM use was 30.0%. The most commonly used CAMs were oral products: vitamins (33.3%), red ginseng (25.0%), and probiotics (19.4%).ConclusionsAwareness of the importance of vaccination and actual vaccination rates were low in IBD patients. Despite insufficient evidence on the effectiveness of CAMs in IBD patients, many patients used CAMs. We believe that repeated education and promotion of vaccination are important. Further large-scale studies to investigate the efficacy and safety of CAMs are warranted in patients with IBD

    The First Very Long Baseline Interferometry Image of 44 GHz Methanol Maser with the KVN and VERA Array (KaVA)

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    We have carried out the first very long baseline interferometry (VLBI) imaging of 44 GHz class I methanol maser (7_{0}-6_{1}A^{+}) associated with a millimeter core MM2 in a massive star-forming region IRAS 18151-1208 with KaVA (KVN and VERA Array), which is a newly combined array of KVN (Korean VLBI Network) and VERA (VLBI Exploration of Radio Astrometry). We have succeeded in imaging compact maser features with a synthesized beam size of 2.7 milliarcseconds x 1.5 milliarcseconds (mas). These features are detected at a limited number of baselines within the length of shorter than approximately 650 km corresponding to 100 Mlambda in the uv-coverage. The central velocity and the velocity width of the 44 GHz methanol maser are consistent with those of the quiescent gas rather than the outflow traced by the SiO thermal line. The minimum component size among the maser features is ~ 5 mas x 2 mas, which corresponds to the linear size of ~ 15 AU x 6 AU assuming a distance of 3 kpc. The brightness temperatures of these features range from ~ 3.5 x 10^{8} to 1.0 x 10^{10} K, which are higher than estimated lower limit from a previous Very Large Array observation with the highest spatial resolution of ~ 50 mas. The 44 GHz class I methanol maser in IRAS 18151-1208 is found to be associated with the MM2 core, which is thought to be less evolved than another millimeter core MM1 associated with the 6.7 GHz class II methanol maser.Comment: 19 pages, 3 figure
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