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Lee, Sunggyu,Kim, Sunmi,Park, Jeongim,Kim, Hai-Joong,Choi, Gyuyeon,Choi, Sooran,Kim, Sungjoo,Kim, Su Young,Kim, Sungkyoon,Choi, Kyungho,Moon, Hyo-Bang Elsevier 2018 Science of the Total Environment Vol.612 No.-
<P><B>Abstract</B></P> <P>Breastfeeding is an important exposure pathway to perfluoroalkyl substances (PFASs) for newborn infants. Nevertheless, reports are limited on the occurrence and time-course of PFASs in breast milk, and most studies have focused on the analysis of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In this study, 16 PFASs were analyzed in breast milk samples (<I>n</I> =293) collected from 128 mothers in Korea during various lactation periods to assess maternal exposure levels, contamination profiles, time-course variations, and infant health risks. The total concentrations of PFASs (ΣPFAS) ranged from 31.7 to 1004 (median: 188) ng/L, which was within the ranges recently reported for Asian and European populations. After a month of nursing, the concentrations of PFOS, PFOA, perfluorononanoic acid (PFNA), and ΣPFAS significantly increased. This could be due to changes in the dietary and behavior patterns of the mothers after the first month of lactation. The concentrations of PFOS and PFOA were significantly correlated with maternal age, body mass index, and parity. Certain types of diet (e.g. consuming snacks and milk) and eating-out frequency were significantly associated with increasing levels of PFAS. Significant correlations and similar time-course trends were found between PFASs and PCBs/DDTs, implying similar exposure sources and biokinetics for these contaminants. The estimated daily intakes of PFOS and PFOA via the consumption of breast milk were below the tolerable daily intakes for infants suggested by the European Food Safety Authority (EFSA).</P> <P><B>Highlights</B></P> <P> <UL> <LI> PFOS, PFOA, PFUnDA, and PFNA were the predominant compounds in breast milk. </LI> <LI> Concentrations of PFASs were significantly correlated with maternal age, BMI, and parity. </LI> <LI> Increased levels of PFASs were found in breast milk after the first month of nursing. </LI> <LI> Snack consumption and frequency of eating-out were significantly associated with increased PFAS levels. </LI> <LI> The infant exposure levels of PFOS and PFOA via breast milk were lower than the TDI. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Jeong, Yunsun,Lee, Sunggyu,Kim, Sunmi,Park, Jeongim,Kim, Hai-Joong,Choi, Gyuyeon,Choi, Sooran,Kim, Sungjoo,Kim, Su Young,Kim, Sungkyoon,Choi, Kyungho,Moon, Hyo-Bang Elsevier 2018 Science of the Total Environment Vol.612 No.-
<P><B>Abstract</B></P> <P>The placenta is a crucial organ for the supply of oxygen and nutritional elements from mother to fetus. Several studies have reported evidence of the placental transfer of persistent organic pollutants (POPs). Despite the importance of prenatal exposure to POPs, the transport process of POPs via the human placenta is not well understood. To investigate the transport processes of these contaminants and to assess the feasibility of the placenta as a non-invasive biological matrix, we measured 19 polychlorinated biphenyls (PCBs), 18 organochlorine pesticides (OCPs), and 24 polybrominated diphenyl ethers (PBDEs) in placenta tissues. The total concentrations of PCBs, OCPs, and PBDEs in placental tissues ranged from 0.36 to 75.2 (median: 5.85) ng/g lipid wt, 1.37 to 250 (63.5) ng/g lipid wt, and 1.21 to 427 (11.7) ng/g lipid wt, respectively. The BDE 209 concentrations were higher than those reported in previous studies presumably because of the high consumption of deca-BDE technical mixtures in Korea. The concentrations of all of the POPs in placental tissues correlated significantly with each other, but BDE 209 concentration did not correlate with that of any other contaminants possibly because of different exposure sources and kinetics. Maternal age, body mass index, and parity were contributors to the accumulation of several POPs in the placenta. Partitioning ratios between maternal blood–placenta–cord blood showed that lower molecular-weight and hydrophobic POPs were preferentially transported from maternal blood to the placenta and that higher molecular-weight and hydrophobic contaminants tended to remain in placental tissues. Regression analysis showed significant relationships between the POP concentrations in multiple biological matrices such as maternal blood, placenta, cord blood, and meconium. These relationships suggest that the placenta can be used as a non-invasive matrix for biomonitoring prenatal exposure to several POPs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PCBs, OCPs, and PBDEs were measured in 108 placental tissues from the Korean women. </LI> <LI> Maternal age, body mass index, and parity were related to placental POP levels. </LI> <LI> Molecular weight and liposolubility influenced POP transport via the human placenta. </LI> <LI> The placenta may be a non-invasive matrix for biomonitoring of prenatal POP exposure. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Shin, Mi-Yeon,Kim, Sunmi,Lee, Sunggyu,Kim, Hai-Joong,Lee, Jeong Jae,Choi, Gyuyeon,Choi, Sooran,Kim, Sungjoo,Kim, Su Young,Park, Jeongim,Moon, Hyo-Bang,Choi, Kyungho,Kim, Sungkyoon Elsevier 2018 Science of the Total Environment Vol.616 No.-
<P><B>Abstract</B></P> <P>Many scientists made estimates of the body burden of PBDEs from breastmilk and house dust. Interestingly, they have not included the prenatal contribution to the body burden in young children after birth. In order to address how the prenatal contribution is important in the risk assessment of PBDEs in infants up to five years old, we used the median measurements of BDE-47 as a model chemical in 108 neonates in Korea, and made simulations of its disposition out of body from birth to five years. During the simulation periods, the environmental exposure was considered for house dust, babyfood, breastmilk consumption, etc., with assumption of typical exposure scenario applicable to general infants in Korea. About 22% of the total amounts of BDE-47 in newborn remained up to 5years after birth. The relative amounts of BDE-47 from the prenatal source were 20%, 14%, 10%, 8%, 6%, and 4% of the total body burden for 1-, 2-, 3-, 4- and 5-year after birth, respectively. The contribution from breastfeeding was 95.2% and 92.2% of the total postnatal exposure amounts at 6-month and 1-year after birth, respectively. After cease of breastfeeding at 1-yr, house dust and food were the important sources of exposure up to 5-yr; however, their contributions to the bodyburden were negligible with consideration of the remaining amounts of the analytes from the breastmilk and prenatal exposure. Suggestively, the innate amounts and pharmacokinetics should be counted in estimating bodyburden of BDE-47.</P> <P><B>Highlights</B></P> <P> <UL> <LI> About 22% of total BDE-47 in newborn remained up to 5years after birth. </LI> <LI> Its relative amounts were 20%, 14%, 10%, 8%, and 6% of the total body burden at 1-, 2-, 3-, 4-, and 5-yr after birth. </LI> <LI> Breastmilk is the most important source of exposure to BDE-47 compared to other environmental sources after birth. </LI> <LI> Suggestively, the innate amounts and pharmacokinetics should be counted in estimating body burden of BDE-47. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Jeong, Seong-Gu,Kim, Sunggyu,Kim, Han Gyung,Kim, Eunji,Jeong, Deok,Kim, Ji Hye,Yang, Woo Seok,Oh, Junsang,Sung, Gi-Ho,Hossain, Mohammad Amjad,Lee, Jongsung,Kim, Jong-Hoon,Cho, Jae Youl Elsevier 2019 Journal of Ethnopharmacology Vol.231 No.-
<P><B>Abstract</B></P> <P><B>Ethnopharmacological relevance</B></P> <P> <I>Mycetia cauliflora</I> Reinw. (Rubiaceae) has been used as a traditional remedy to ameliorate clinical signs of inflammatory diseases, including pain, inflammation, ulcers, and wounds. Among the Mycetia subfamilies, the molecular and cellular mechanisms of <I>Mycetia longifolia</I> (Rubiaceae) have been studied. However, those of <I>Mycetia cauliflora</I> are not clearly understood. Comprehensive investigation of this plant is necessary to evaluate its potential for ethnopharmacological use.</P> <P><B>Materials</B></P> <P>and methods: The activities of <I>Mycetia cauliflora</I> methanol extract (Mc-ME) on the secretion of inflammatory mediators, the mRNA expression of proinflammatory cytokines, and identification of its molecular targets were elucidated using lipopolysaccharide (LPS)-induced macrophage-like cells. Moreover, the suppressive actions of Mc-ME were examined in an LPS-induced peritonitis mouse model.</P> <P><B>Results</B></P> <P>At nontoxic concentrations, Mc-ME downregulated the release of nitric oxide (NO), the mRNA expression of inducible nitric oxide synthase (iNOS), and the mRNA expression of interleukin (IL)-1β from LPS-activated RAW264.7 cells. This extract also inhibited the nuclear translocation of p65 and p50 and the phosphorylation of IκBα, IKK, and AKT. Western blot analysis and <I>in vitro</I> kinase assays confirmed that phosphoinositide-dependent kinase-1 (PDK1) is the direct immunopharmacological target of Mc-ME effect. In addition, Mc-ME significantly reduced inflammatory signs in an animal model of acute peritonitis. These effects were associated with decreased NO production and decreased AKT phosphorylation.</P> <P><B>Conclusion</B></P> <P>Our results suggest that Mc-ME displays anti-inflammatory actions in LPS-treated macrophage-like cells and in an animal model of acute inflammatory disease. These actions are preferentially managed by targeting PDK1 in the nuclear factor (NF)-κB signaling pathway.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Jhung Myung Jo,Jang Changheui,Kim Seok Hun,Choi Young Hwan,Kim Hho Jung,Jung Sunggyu,Kim Jong Min,Sohn Gap Heon,Jin Tae Eun,Choi Taek Sang,Kim Ji Ho,Kim Jong Wook,Park Keun Bae The Korean Society of Mechanical Engineers 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.2
Performed here is a comparative assessment study for the probabilistic fracture mechanics approach of the pressurized thermal shock of the reactor pressure vessel. A round robin consisting of one prerequisite deterministic study and five cases for probabilistic approaches is proposed, and all organizations interested are invited. The problems are solved by the participants and their results are compared to issue some recommendation of best practices and to assure an understanding of the key parameters in this type of approach, like transient description and frequency, material properties, defect type and distribution, fracture mechanics methodology etc., which will be useful in the justification through a probabilistic approach for the case of a plant over-passing the screening criteria. Six participants from 3 organizations responded to the problem and their results are compiled and analyzed in this study.
Myung Jo Jhung,Changheui Jang,Seok Hun Kim,Young Hwan Choi,Hho Jung Kim,Sunggyu Jung,Jong Min Kim,Gap Heon Sohn,Tae Eun Jin,Taek Sang Choi,Ji Ho Kim,Jong Wook Kim,Keun Bae Park 대한기계학회 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.2
Performed here o a comparative assessment study for the probabilistic fracture mechanics approach of the pressurized thermal shock of the reactor pressure vessel A round consisting of one prerequisite deterministic study and five cases for probabilistic approaches io proposed, and all organizations interested are invited The problems are solved by the participants and their results are compared to issue some recommendation of best practices and to assure an understanding of the key parameters in this type of approach, like transient description and frequency, material properties, defect type and distribution, fracture mechanics methodology etc, which will be useful in the justification through a probabilistic approach for the case of a plant over-passing the screening criteria Six participants from 3 organizations responded to the problem and their results are compiled and analyzed in this study.
Multi-routing based Mobility Management with an Optimized Security Network
Sunggyu Kim,Byungjoo Park 대한전자공학회 2019 IEIE Transactions on Smart Processing & Computing Vol.8 No.4
Recently, there has been a drastic increase in the risk of personal information leakage brought about by inconsistencies in network security triggered by cyber-attacks. The persistent surge of internet users is paralleled by the demands for wireless services, which have become more susceptible to cyber-attacks, compared with wired services. Thus, a high level for quality of service is essential when providing wireless services to users. In addition, a reduced handover delay when a mobile node moves between network access points must be provided by wireless network systems. However, with a stronger security system implemented in a wireless environment, it follows that there will be a significant increase in handover delay. It simply means that current wireless network systems are unable to provide the desired QoS for the wireless services demanded by Internet users. Consequently, various security and QoS enhancement protocols have been studied and developed, but a lot more challenges need to be addressed. This paper proposes a robust security scheme to support fast handovers for mobility management protocols over Internet Protocol version 6 (IPv6) through utilization of an exchange key.