Rare B decays at BaBar

Eunil Won 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.2

Recent results in rare B decays are presented. Topics include purely leptonic, radiative, and b to sl+lက decays. Results are based on e+eက annihilation data collected with the BaBar detector at the (4S) resonance during the years 1999-2002 at the PEP-II asymmetric-energy B factory at SLAC.

Fabrication of a prototype of the Belle-II central drift chamber for development of the level-1 trigger system

Won Eunil,Moon Hyunki 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.2

The Belle-II experiment at the SuperKEKB aims to achieve a target instantaneous luminosity of 8 × 1035 cm−2s−1 . To cope with the design luminosity, the sub-detectors and the level-1 trigger system are required to be upgraded. The central drift chamber in the Belle-II detector which plays a primary role in the track reconstruction of charged particles is a multi-wire drift chamber with 14,336 channels. The central drift chamber-based trigger is responsible for distinguishing specific types of physics, which is based on fast track reconstruction. The fabrication of a small prototype of the central drift chamber and the development process of the central drift chamber-based trigger system are described.

Development of an event time finding algorithm for multi-wire drift chamber-based Level-1 trigger system in the Belle II experiment

Won Eunil,Moon Hyunki 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.2

The Belle II detector at the SuperKEKB e+e− collider in Japan is designed for precise measurements of weak interaction parameters and new physics beyond the Standard Model; therefore, it requires very high instantaneous luminosity. To handle such high luminosity, the level-1 trigger system in the Belle II experiment is designed to efficiently trigger events of interest with the highest efficiency. Among many sub-detectors, track reconstruction of charged particles is performed using information collected from the central drift chamber. Therefore, the central drift chamber-based trigger plays a central role in distinguishing specific types of physics based on fast track reconstruction. To improve the longitudinal position resolution of a track vertex and for the fine-tuning of trigger signal timing, the time of the collision, which we call event time, is necessary. We developed an event time finding algorithm using the wire hit time information obtained from the central drift chamber and validated our algorithm through Monte Carlo simulation.

아토피피부염 환자에서 체내 거대분자에 대한 산화 스트레스 지표 평가

이은일 ( Eunil Lee ),오은하 ( Eun Ha Oh ),송해준 ( Hae Jun Song ),최원준 ( Won Jun Choi ),백진옥 ( Jin Ok Baek ),이종록 ( Jong Rok Lee ),노주영 ( Joo Young Roh ) 대한피부과학회 2015 대한피부과학회지 Vol.53 No.6

Background: Excessive exposure to reactive oxygen species (ROS) or decreased antioxidants leads to damage of proteins, lipids, and DNA. Previous studies suggest that oxidative stress may be important in the pathogenesis of atopic dermatitis. Objective: To investigate whether oxidative stress is increased in atopic dermatitis patients compared to a normal control group, we examined DNA damage, lipid peroxidation, ROS production and antioxidant expression. Methods: Patients with atopic dermatitis (n=16; mean Scoring Atopic Dermatitis [SCORAD] index=53.06) were investigated compared to a normal control group (n=25). To examine DNA damage in the cellular level, we performed comet assays on lymphocytes and granulocytes taken from patients and control group. To measure lipid peroxidation products, urine and plasma malondialdehyde (MDA) levels were analyzed. To examine intracellular redox in lymphocytes, ROS were measured using flow cytometry. Expression of superoxide dismutase (SOD) 1, 2 antioxidants were analyzed using reverse transcription polymerase chain reaction (RT-PCR). Results: Atopic dermatitis patients showed severe DNA damage compared to the control group in both lymphocytes (1.89 and 1.51, respectively, p<0.05) and granulocytes (2.07 and 1.58, respectively, p<0.05). While urine MDA levels were not significantly different between groups (1.64 and 1.13 μM/g respectively, p>0.05), plasma MDA levels were significantly increased in atopic dermatitis patients compared to controls (1.45 and 0.80 μM/g respectively, p<0.005). ROS production by activated lymphocytes was increased in atopic dermatitis patients compared to controls. SOD 1, 2 were expressed in all atopic dermatitis patients without significant increase compared to controls. Conclusion: Increased DNA damage, lipid peroxidation and ROS production in lymphocytes as indices of oxidative stress were observed in moderate to severe atopic dermatitis patients compared to normal control. Although precise mechanism of oxidative stress on the pathogenesis of atopic dermatitis is not defined yet, decreasing ROS exposure or augmenting antioxidant defenses may be alternative therapeutic approaches for atopic dermatitis. (Korean J Dermatol 2015;53(6):456∼461)

DNA Damage in T and B Lymphocytes, Bone Marrow, Spleens, and Livers of Rats Exposed to Benzene

Lee, Eunil,Im, Hosub,Oh, Eunha,Jung, Woon-Won,Kang, Hyung-Sik,Sul, Donggeun Taylor Francis 2005 Inhalation toxicology Vol.17 No.7

<P>Single-cell gel electrophoresis assays were performed in order to evaluate DNA damage occurring in the T and B lymphocytes, spleens, bone marrow, and livers of rats exposed to benzene at a concentration of 100, 200, or 400 ppm for 2 or 4 wk. The level of t , t -muconic acid ( t , t -MA), which is a urinary benzene metabolite, was determined. In the control rats, mean Olive tail moments in the T and B lymphocytes were 1.507 ± 0.398 and 1.579 ± 0.206, respectively. DNA damage in the T and B lymphocytes exposed to 400 ppm benzene for 4 wk caused those rats to exhibit the highest Olive tail moments, with their values measured as 4.351 ± 0.510 and 3.140 ± 0.631, respectively. Also, the t , t -MA levels increased directly with increasing benzene exposure time and dose during the 4 wk. After 4 wk, the levels of t , t -MA in urine from rats exposed to 100, 200, and 400 ppm were 19.30 ± 5.62, 30.36 ± 4.46, and 46.93 ± 9.10 mg/g creatinine. In conclusion, the present study demonstrates that benzene exposure results in significant DNA damage in the T and B lymphocytes, bone marrow, spleens, and livers of rats. DNA damage in the blood cells and organs was also discovered to vary directly with benzene exposure, in both a dose-dependent and time-dependent manner. In addition, a similar trend regarding DNA damage was found in the blood cells and organs, and evidenced a good association with the level of t , t -MA in the urine.</P>

Analysis of low molecular weight plasma proteins using ultrafiltration and large gel two-dimensional electrophoresis

Jung, Woon-Won,Phark, Sohee,Oh, Sangnam,Khim, Jin-Young,Lee, Juneyoung,Nam, Myung Hee,Seo, Jong Bok,Park, So-Young,Jo, Eunkyung,Choi, Seonyoung,Zheng, Zhi,Lee, Ji Young,Lee, Min,Lee, Eunil,Sul, Dongge WILEY-VCH Verlag 2009 Proteomics Vol.9 No.7

<P>In this study, various solvent systems were applied to obtain a high and consistent recovery rate of low molecular weight plasma proteins (LMPP) from human plasma. A buffer system containing 7 M urea, 2 M thiourea, 25 mM NH<SUB>4</SUB>HCO<SUB>3</SUB> + 20% ACN (pH 8.2) produced the highest recovery rate of LMPP. To validate the recovery of cut off membrane (COM) obtained using the urea buffer system, 27 different 30 kDa COMs were used to prepare the LMPP sample which were then subjected to 1-D SDS-PAGE. Statistical analysis showed that the buffer system with COM produced a consistent the recovery of LMPP. In addition, 2-DE analysis was also conducted to determine the relative intensity of each protein spot. When molecular weight ranges over 30 kDa and under 30 kDa were evaluated, 953 and 587 protein spots were observed in the gels, respectively, resulting in a total of 1540 protein spots being resolved. Identification of the major proteins were then performed using a nano-LC/MS system comprised of an HPLC system and an ESI-quadrupole IT MS equipped with a nano-ESI source.</P>

Development of cloud monitoring system for cosmic microwave background observations

Jeong Hoyong,Ahn Yongheon,Won Eunil,이경민 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.1

The cloud between a ground-based telescope and the sky signal, such as cosmic microwave background, can distort the measured temperature signal from the sky, or even obstruct it. We developed a cloud monitoring system for cosmic microwave background observations. This system uses infrared imaging sensors; therefore, it is independent of visible legibility and the monitoring is capable day and night. The sensors and their controller are protected by a weather-proof container and able to be installed at the bare ground exposed to the external environment. By our system, information of sky area covered by clouds can be provided for ground-based telescopes by 0.37◦ resolution. The design and fabrication of the cloud monitoring system as well as its initial performance are described.

초기 댓글이 성공적인 온라인 대화 형성에 미치는 영향

원예은(Ye-eun Won),강지원(Jiwon Kang),박은일(Eunil Park),고민삼(Minsam Ko),김기준(Ki Joon Kim),한진영(Jinyoung Han) 한국HCI학회 2019 한국HCI학회 학술대회 Vol.2019 No.2

커뮤니케이션 기술의 급격한 발달로 많은 사람들이 온라인 환경에서 대화할 수 있게 되었다. 특히 소셜미디어는 활발한 커뮤니케이션이 이루어지는 대표적인 온라인 채널 중 하나이다. 본 연구에서는 소셜 미디어상에서 성공적인 온라인 커뮤니케이션을 가능하게 하는 초기 댓글과 포스트의 역할에 대해 분석한다. 이를 위해, 대화형 소셜 미디어 중 하나인 Reddit 의 하위 커뮤니티들 중 뉴스와 관련된 커뮤니티에서 데이터를 수집하고 분석하였다. 다중회귀 분석 결과, 포스트와 초기 댓글의 선호 지수가 성공적인 온라인 커뮤니케이션에 유의미한 영향을 끼친다는 것을 확인하였다. 또한, 사람들은 포스트가 쉽고 직관적인 내용을 가질 때, 적극적으로 대화에 참여한다는 것을 발견할 수 있었다.

Level 1 Trigger System for the Belle II Experiment

Iwasaki, Y.,ByungGu Cheon,Eunil Won,Xin Gao,Macchiarulo, L.,Nishimura, K.,Varner, G. IEEE 2011 IEEE transactions on nuclear science Vol.58 No.4

<P>The super-KEKB <I>B</I> factory, currently under construction at the KEK High Energy Accelerator Research Organization in Japan, has a goal of producing 50 ab<SUP>-1</SUP> of integrated luminosity, thus allowing the Belle II experiment to study rare decays of <I>B</I> mesons, <I>D</I> mesons, and τ leptons. Such large statistics on these decays provide an experimental probe of physics beyond the Standard Model. An online trigger system is indispensable to Belle II to reduce the number of beam background events associated with high electron and positron beam currents, as well as to enhance physics-oriented events. For this purpose, we have designed the Belle II online trigger system with two kinds of primary Level 1 trigger components: a track trigger and an energy trigger. The track trigger is composed of 2-dimensional and 3-dimensional tracking algorithms, and the energy trigger implements algorithms based on total energy, isolated clusters, and identification of Bhabha events. In addition, precise event trigger timing and muon tagging information are provided by the time-of-propagation detector and iron flux return muon detector, respectively.</P>

Benzene increases the ratio of arachidonic acids to docosahexaenoic acids and inhibits the de novo synthesis of ceramide in the rat liver

Sul, Donggeun,Shim, Ilsub,Im, Hosub,Won, NamHee,Kim, Hae-Joon,Lee, Eunil WILEY 2005 Journal of Applied Toxicology Vol. No.

<P>The present study investigated the effects of inhalation exposure of benzene at 0, 10, 200 and 600 ppm for 1, 2 and 4 weeks on n-6 and n-3 fatty acids and ceramide levels in the rat liver. No signicant difference in the ratio of saturated fatty acid to unsaturated fatty acid was found on increasing benzene exposure levels, but the ratio of saturated fatty acid to unsaturated fatty acid decreased with increasing benzene exposure times, with the exception of the phospholipids of rats exposed to 200 and 600 ppm of benzene. A signicant increase in the ratio of arachidonic acid to docosahexaenoic acid was found in the phospholipids of rats exposed to 200 and 600 ppm of benzene for 4 weeks. In our study, no change in the relative amounts of sphingomyelin in phospholipids, due to benzene exposure at 600 ppm for 4 weeks resulted in the lack of sphingomyelin turnover. However, ceramide levels in the livers of rats exposed to 600 ppm of benzene for 4 weeks were signicantly reduced upon increasing the benzene concentration. This result shows that the de novo synthesis of ceramide was signicantly inhibited at higher levels of benzene and that the ratio of arachidonic acid to docosahexaenoic acid in phospholipids is dose-dependently related to benzene exposure. Copyright © 2005 John Wiley & Sons, Ltd.</P>