Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

<P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

선성방광염을 동반한 골반지방종증 1례

최창훈,심주명,부명섭,최호철,민권식,최성협 大韓泌尿器科學會 1997 Korean Journal of Urology Vol.38 No.7

Vascular Protective Role of Samul-Tang in HUVECs: Involvement of Nrf2/HO-1 and NO

Choi, Eun Sik,Lee, Yun Jung,Seo, Chang Seob,Yoon, Jung Joo,Han, Byung Hyuk,Park, Min Cheol,Kang, Dae Gill,Lee, Ho Sub Hindawi Publishing Corporation 2016 Evidence-based Complementary and Alternative Medic Vol.2016 No.-

<P>Samul-Tang (Si-Wu-Tang, SMT), composed of four medicinal herbs, is a well-known herbal formula treating hematological disorder or gynecologic disease. However, vascular protective effects of SMT and its molecular mechanisms on the vascular endothelium, known as the central spot of vascular inflammatory process, are not reported. The aim of this study was to investigate vascular protective effects of SMT water extract in human umbilical vein endothelial cells (HUVECs). Water extract of SMT was prepared and identified by HPLC-PDA analysis. Expression of cell adhesion molecules (CAMs) and heme oxygenase-1 (HO-1) and translocation of nuclear factor-kappa B (NF-<I>κ</I>B) and nuclear factor-erythroid 2-related factor 2 (Nrf2) were determined by western blot. Nuclear localization of NF-<I>κ</I>B and Nrf2 was visualized by immunofluorescence and DNA binding activity of NF-<I>κ</I>B was measured. ROS production, HL-60 monocyte adhesion, and intracellular nitric oxide (NO) were also measured using a fluorescent indicator. SMT suppressed NF-<I>κ</I>B translocation and activation as well as expression of CAMs, monocyte adhesion, and ROS production induced by TNF-<I>α</I> in HUVECs. SMT treated HUVECs showed upregulation of HO-1 and NO which are responsible for vascular protective action. Our study suggests that SMT, a traditionally used herbal formula, protects the vascular endothelium from inflammation and might be used as a promising vascular protective drug.</P>

Season‐dependent warming characteristics observed at 12 stations in South Korea over the recent 100 years

Choi, Woosuk,Ho, Chang‐,Hoi,Kim, Maeng‐,Ki,Kim, Jinwon,Yoo, Hee‐,Dong,Jhun, Jong‐,Ghap,Jeong, Jee‐,Hoon John Wiley Sons, Ltd. 2018 International journal of climatology Vol.38 No.11

<P>A number of studies on the surface warming in the Korean Peninsula reported that there has been a notable increasing trend of surface air temperatures over the past several decades. Here, by analysing long‐term surface air temperature data at 12 stations in South Korea that have records longer than 60 years, the authors show that the warming of spring and autumn temperatures is characterized by quasi‐linear increases with time whereas the warming in winter and summer is characterized by one or two abrupt jumps. Change‐point analysis of the seasonal‐mean temperature time series shows that abrupt jumps in winter temperatures occurred in the late 1940s and late 1980s, while the jump in summer temperatures occurred in 1994 at most stations. The shape of the frequency distribution of the daily‐mean temperature anomalies at all stations shifts to the warmer side after the jumps for both winter and summer. This shift in turn results in the decrease of cold extremes in winter and the increase of warm extremes in summer at all stations. Our results indicate that recent temperature records in South Korea are characterized by the two different types of warming according to seasons.</P>

Rheology of Decamethylceclopentasiloxane (cyclomethicone) W/O Emulsion System

Choi, Min-Hyung,Jeong, So-Ra,Nam, Sang-In,Shim, Sang-Eun,Chang, Yoon-Ho The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.12

A highly dispersed W/O emulsion of silicone oil (cyclomethicone)/water system was prepared with a nonionic surfactant. The surface and interfacial tension between the oil and water were characterized in terms of the droplet size distribution and viscosity change of the emulsion. When the dispersed phase concentration was relatively high, the viscosity of the emulsion was rapidly increased and the droplet size of the emulsion was decreased. The rheological behavior of the emulsion system showed non-Newtonian and shear thinning phenomena depending upon the content of the dispersed phase. The droplet size of the emulsion was decreased with increasing surfactant content and water concentration. The relative viscosity of the emulsion was better predicted with the Choi-Schowalter model than with the Taylor model. The value of the complex modulus increased with increasing surfactant concentration. The linear viscoelastic region was expanded with a dispersed phase concentration. According to the change in the viscosity, the behavior was classified into three distinct regions: [I] linear viscoelastic, [II] partially viscoelastic, and [III] viscous. The creep/recovery behaviors in each region were characterized.

Encephalo-duro-arterio-synangiosis(EDAS) using Occipital Artery in Children with Moyamoya Disease

Choi, In-Jae,Hong, Seok-Ho,Cho, Byung-Kyu,Wang, Kyu-Chang,Kim, Seung-Ki The Korean Neurosurgical Society 2005 Journal of Korean neurosurgical society Vol.38 No.6

Objective : Although an encephaloduroarteriosynangiosis procedure using the superficial temporal artery [STA-EDAS] is an effective indirect bypass method in children with moyamoya disease[MMD], there is still a need for an additional bypass operation that can cover the area of the posterior circulation. The goal of this study is to evaluate the efficacy of the EDAS procedure using the occipital arteries [OA-EDAS]. Methods : From August 2003 to April 2004, We performed OA-EDAS in sixteen patients with MMD who have a circulatory insufficiency in the territory of the posterior cerebral artery[PCA]. The medical records were reviewed retrospectively. The surgical outcomes, including the changes in neurological status and imaging studies, with the degree of neovascularization on the cerebral angiogram, and the hemodynamic changes on single-photon emission computed tomography[SPECT], were analyzed. Results : These 16 children consisted of 5 boys and 11 girls aged 2 to 9 years. The clinical outcome of their PCA symptoms, such as visual transient ischemic attacks[TIAs] or visual field defect, was favorable in 14 patients of 16. Nine patients of 11 who underwent follow up magnetic resonance imaging[MRI] showed favorable MRI changes. On angiogram most of the patients exhibited good or fair revascularization of the PCA territory [7 of 8]. The hemodynamic changes on SPECT in the PCA territory after surgery showed improved vascular reserve in 13 of the 16 territories. Conclusion : OA-EDAS is a safe and efficacious revascularization procedure in patients with MMD who have compromised cerebral perfusion in PCA territory, or with visual TIAs.

Changes of Sugar Composition and Related Enzyme Activities during Fruit Development of Asian Pear Cultivars ‘Niitaka’ and ‘Whangkeumbae’

Jin-Ho Choi,Jang-Jeon Choi,Chang-Seok Bang,Jung-Sup Lee,Dong-Woog Choi,Hye-Sun Cho,Jun Cheul Ahn 한국원예학회 2009 Horticulture, Environment, and Biotechnology Vol.50 No.6

We report on the seasonal changes of soluble sugar accumulation and several enzyme activities related to sugar metabolism, in two Asian pear cultivars (Pyrus pyrifolia) cultivars ‘Niitaka’ and ‘Whangkeumbae’. Soluble sugar content increased as the fruit developed and its total contents in matured fruits were 104.6 and 95.1 ㎎ㆍg?¹ fresh weight for ‘Niitaka’ and ‘Whangkeumbae’, respectively. However, the fructose-glucose-sucrose-sorbitol ratio was not significantly changed. Sorbitol-6-phosphate dehydrogenase activity was maintained at high level in leaves and low in fruits throughout the fruit development, although the enzyme activity highly fluctuated in young and mature fruits. NAD-dependent sorbitol dehydrogenase activity increased sigmoidally in both leaves and fruits during fruit development, and correlated with accumulation of total sugar in fruits. Sucrose synthase and sucrose phosphate synthase (SPS) activities remained low in leaves, but higher with two peak fluctuations in fruits. The change of soluble sugar contents positively correlated with SPS activity, based on the seasonal fluctuation of SPS activity and soluble sugar accumulation.

<i>Toxoplasma gondii</i> protects against H₂O₂‐induced apoptosis in ARPE‐19 cells through the transcriptional regulation of apoptotic elements and downregulation of the p38 MAPK pathway

Choi, Si‐,Hwan,Park, Sung Jun,Cha, Guang‐,Ho,Quan, Juan Hua,Chang, Nam‐,Sik,Ahn, Myoung‐,Hee,Shin, Dae‐,Whan,Lee, Young‐,Ha Blackwell Publishing Ltd 2011 Acta ophthalmologica Vol.89 No.4

<P><B>Abstract.</B></P><P><B>Purpose: </B> Toxoplasmosis, which is caused by the protozoan parasite <I>Toxoplasma gondii</I>, can lead to severe visual impairment. <I>T.?gondii</I> inhibits or delays programmed cell death caused by various apoptotic triggers; however, the mechanisms involved in the <I>T</I>.?<I>gondii</I>‐induced suppression of apoptosis in retinal cells have not been analysed in detail.</P><P><B>Methods: </B> We investigated the role of <I>T</I>.<I>?gondii</I> infection in H<SUB>2</SUB>O<SUB>2</SUB>‐induced apoptosis in human retinal pigment epithelial cells (ARPE‐19) by monitoring the activities of apoptosis‐regulating molecules and mitogen‐activated protein kinases (MAPKs), including p38 MAPK. We also examined the gene downstream from p38 MAPK.</P><P><B>Results: </B> <I>T.?gondii</I> infection significantly inhibited the cellular toxicity of H<SUB>2</SUB>O<SUB>2</SUB> (500 μ<SMALL>m</SMALL>) and increased cell viability in a multiplicity of infection (MOI)‐dependent manner by reducing DNA fragmentation and reactive oxygen species (ROS) generation in ARPE‐19 cells. Western blot analysis also showed that <I>T</I>.?<I>gondii</I> infection prevented the host cell expression of pro‐apoptotic factors, such as Bad and Bax, and the activation of caspase‐3. Infection with <I>T</I>.?<I>gondii</I> increased the expression of the anti‐apoptotic factor Bcl‐2 in ARPE‐19 cells under oxidative stress. In accordance with these findings, <I>Toxoplasma</I> infection was protective enough to suppress the phosphorylation of p38 MAPK following H<SUB>2</SUB>O<SUB>2</SUB> treatment. Exposure to H<SUB>2</SUB>O<SUB>2</SUB> increased the expression of heme oxygenase‐1 (HO‐1) in ARPE‐19 cells, and its expression was significantly inhibited in H<SUB>2</SUB>O<SUB>2</SUB>‐treated infected cells.</P><P><B>Conclusion: </B> The protective function of <I>T</I>.?<I>gondii</I> infection against ROS‐induced apoptosis results from changes in the expression of apoptotic molecules and the downregulation of stress‐induced intracellular signalling.</P>

탄력성 분석을 통한 화주의 운송수단 선택특성 연구

최창호 한국로지스틱스학회 2003 로지스틱스연구 Vol.11 No.1

도시내와 지역간 교통에서 화물자동차의 통행량이 증가함에 따라 그동안 여객교통에 집중되던 관심이 화물교통에도 기울여지고 있다. 여객교통과 달리 화물교통은 운송되는 화물의 품목과 품목별로 움직이는 운송경로가 다양하여 여객교통과는 다른 관점으로 해석하는 것이 필요하다. 특히 화물교통의 의사결정주체는 화물이 아닌 화주이기 때문에 화주가 운송수단에 대해 느끼는 효용을 파악하고 그에 대한 특성을 연구하는 것이 중요하다. 운송수단에 대한 화주의 효용을 파악하기 위해 자주 인용되는 것이 탄력성이다. 탄력성이란 화주의 운송수단 선택에 영향을 미치는 변수의 값이 변화함에 따라 해당 운송수단의 시장점유율이 변화하는 정도를 의미한다. 본 연구는 자가용화물자동차와 영업용화물자동차로 운송되는 공로화물을 대상으로 탄력성을 산정하여 화주가 느끼는 효용의 차이를 해석하였다. 특히 화물운송이 도시내와 지역간 등 공간적인 차이와 화물의 품목별로 다른 특징을 나타냄을 감안하여 공간적인 분류에 따른 탄력성과 더불어 화물품목별 탄력성도 산정하였다. 연구의 결과 공간적 분류에 따른 탄력성의 산정에서는 도시내는 자가용이 선호되며 지역간에서는 영업을 더 선호한다는 것을 알 수 있으며, 운송비용의 변화에 따라 자가용이 영업용으로 전환될 확률보다는 영업용에서 자가용으로 전환될 확률이 더욱 높음을 알 수 있었다. 운송시간의 변화에 대해서는 전반적으로 민감하며 도시내는 자가용보다 영업용의 변화에, 그리고 지역간에서는 자가용의 변화에 더욱 민감한 것으로 나타났다. 화물의 품목별로 선정한 탄력성 결과에서는 제조업의 화주가 영업용보다 자가용을 더 선호하는 것으로 나타났다. 이로써 우리나라의 자가용화물자동차 보유가 높은 여러 가지 원인 중에서 도시내 물류활동의 증가와 제조업체 화주의 자가용 선호가 주요한 부분을 차지하는 것으로 평가된다. As the traffic of trucks in both urban and regional transport increases gradually, concerns are getting growing than before in the filed of freight transport. Compare to passenger transport freight transport have many varieties with freight classification codes and transport routes to be taken force researchers to interpret it in different view points. In freight transport the goods cannot decide; different persons may be involved in decision-making at various stages. It is important to understand the utility of each mode in freight transport study. To understand the utilities of shippers, elasticity is frequently referred to the utility of transport mode. It presents a degree of change in market share as variable affecting the selection of transportation mode change. This study interprets the utility of shippers by evaluating elasticity of the road transport which are taken by own trucks or hired trucks. In this study, two kinds of elasticity are suggested to incorporate the spatial difference and freight classification codes: the one is based on the spatial category and the other is based on freight classification codes. As the results of this study, own trucks are preferable to hired trucks with respect to intra-city criterion, whereas hired trucks are preferable to own trucks with respect to inter-city criterion. Depending on transport cost, the shippers use hired truck seem to more likely convent into own trucks than the shippers use own trucks converts into hired trucks. The change of transportation time is sensitive on the whole modes. Especially, it is more sensitive to the change of hired trucks than to that of own trucks in the city, whereas more sensitive to that of own trucks in the urban.

근관충전용 실러의 물리적 성질에 관한 연구

장영인,최호영 大韓齒科保存學會 1995 Restorative Dentistry & Endodontics Vol.20 No.1

AbstractThe purpose of this study was to compare and estimate the physical properties of five root canal sealers classified Calciobiotic root canals sealer as calcium hydroxide based sealer, Apatite root sealer type II as calcium phosphate based sealer, AH-26 as resin based sealer, Canals and Pulpdent root canals sealer as zinc oxide eugenol based sealer.The author investigated dimensional change and flow rate of canal sealers, diametral tensile strength and shear bond strength of sealers to dentin to evaluate the physical proper- ties on affect of complete obturation of root canal and performed the total 100 specimens of each 25 sealers under the condition of root temperature according to manufacturer's instructions. All specimens were stored at 37+1? in 100% relative humidity.A microscope for measurement of micro distance is used for the dimensional change test and evacuation methods using vaccum were used for the flow rate test. The result differed by the storage time measured on the tests of diametral tensile strength and shear bond strength to dentin.The following results were obtained ; 1 On the test of dimensional change. Canals and Pulpdent expanded slightly, AH-26 and Apatite showed the severe shrinkage after 48 hours. 2. AH-26 and Apatite were the excellent with each 24.59mm, 31.19mm after 3 minutes in the aspect of flow property. 3. On the diametral tensile strength, Calciobiotic root canals sealer showed the highest strength with 27.13kg/cm2 after 48 hours, Apatite root sealer type II showed highest strength with 84.57kg/cm2 after 120 hours. 4. On the shear bond strength to dentin, AH-26 was most excellent with 55.73kgf/cm2 after 24 hours and with 134.71kgf/cm2 after 120 hours.