In-Situ X-Ray Fluoroscopic Observation for Motion of Bubbles in Liquid Iron for Correction of Drag Coefficient Used in Numerical Simulation

In-Beom Park,Sang-Joon Kim,Hae-Geon Lee,Youn-Bae Kang 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.4

Rising of Ar bubble in C-saturated liquid iron was investigated in-situ by employing a high power X-Ray fluoroscope (maximum power of 450 kV and 4.5 mA) coupled with a high speed camera. This analysis enabled to track the actual motion of rising bubble in the liquid iron. After post-processing of X-Ray images, size, shape, velocity, and trajectory of the bubble were obtained. The bubbles were found to be not spherical, but ellipsoidal. Their average size could be estimated about 1.1×10 -2 m. The bubbles wobbled during rising and arrived at their terminal velocities within 0.1 sec. The obtained terminal velocities revealed that the governing forces acting on the motion of ellipsoidal bubble were inertia and surface force. This was quite different from that of spherical bubble which was widely used in the assumption for the numerical analysis. As a result, widely applied equation for the drag coefficient (CD = 24 (1 + 0.15Re 0.687 ) / Re) is seen to be applicable only for low Re regime, and this was also confirmed by the drag coefficient derived from the present experimental observation. Therefore, it is suggested to use the following equation for the drag coefficient CD = max [24 (1 + 0.15Re 0.687 ) / Re, 8Eo / 3(Eo + 4)]. Numerical simulation for the Ar bubble behavior in the three dimensional (3D) continuous casting mold was conducted in order to evaluate the effect of the drag coefficient for the behavior of spherical and ellipsoidal bubbles. The numerical results showed that the increased CD based on ellipsoidal regime affected the entire fluid in the mold.

당뇨병환자에서 뇨증 Fibronectin농도의 증가에 관한 연구

한승범,조준승,손건영,서성문,박근용,조성래,박규영,박정모,이인규,여준기 啓明大學校 醫科大學 1994 계명의대학술지 Vol.13 No.4

Plasma fibronectin is an α₂-glyoprotein, which is produced by vascular endothelial cells. Raised level of plasma fibronectin has been observed in diabetic patients particularly in the presence of microvascular complications. However, no available data exist about urine level of this glycoprotein in diabetic patients. We measured urine fibronectin level by ELISA methods in 54 diabetic patients who have microvascular comlications or not. The following results were obtained. 1) Urine fibronectin level(㎍/g creatinine) in diabetic group(1740.0±678.0) is increased compaired with those in normal control group(471.0±59.0). but this results were not significantly different among two groups(P>0.05). 2) Urine fibronectin level(㎍/g creatinine) was significantly increased in patients with nephropathy (6188.0±3144.0) compared with those in normal control group(471.0±59.0) and patients without nephropathy(645.0±251.0)(P<0.001). 3) There were a significant correlation between BUN, creatinine, creatinine clearance, 24hr urine total protein and urine fibronectin level in diabetic patients. Our data suggest that urine fibronectin excretion level might be used as a sensitive guide for diabectic nephropathy.

출생후 흰쥐 망막에서 recoverin면역반응 원뿔두극세포의 분화와 GABA성 무축삭세포와의 연접형성 시기

박대균,김인범,천명훈,정진웅 대한해부학회 1999 Anatomy & Cell Biology Vol.32 No.1

Oct4‐induced oligodendrocyte progenitor cells enhance functional recovery in spinal cord injury model

Kim, Jeong Beom,Lee, Hyunah,Araú,zo‐,Bravo, Marcos J,Hwang, Kyujin,Nam, Donggyu,Park, Myung Rae,Zaehres, Holm,Park, Kook In,Lee, Seok‐,Jin EMBO 2015 The EMBO journal Vol.34 No.23

<P>The generation of patient-specific oligodendrocyte progenitor cells (OPCs) holds great potential as an expandable cell source for cell replacement therapy as well as drug screening in spinal cord injury or demyelinating diseases. Here, we demonstrate that induced OPCs (iOPCs) can be directly derived from adult mouse fibroblasts by Oct4-mediated direct reprogramming, using anchorage-independent growth to ensure high purity. Homogeneous iOPCs exhibit typical small-bipolar morphology, maintain their self-renewal capacity and OPC marker expression for more than 31 passages, share high similarity in the global gene expression profile to wild-type OPCs, and give rise to mature oligodendrocytes and astrocytes in vitro and in vivo. Notably, transplanted iOPCs contribute to functional recovery in a spinal cord injury (SCI) model without tumor formation. This study provides a simple strategy to generate functional self-renewing iOPCs and yields insights for the in-depth study of demyelination and regenerative medicine.</P>

The Clinical Profile of Patients with Psoriasis in Korea: A Nationwide Cross-Sectional Study (EPI-PSODE)

( Hae Jun Song ),( Chul Jong Park ),( Tae Yoon Kim ),( Yong Beom Choe ),( Seok-Jong Lee ),( Nack In Kim ),( Jae We Cho ),( Jie Hyun Jeon ),( Min Soo Jang ),( Jai Il Youn ),( Myung Hwa Kim ),( Joonsoo 대한피부과학회 2017 Annals of Dermatology Vol.29 No.4

Background: Psoriasis is an immune-mediated, chronic in-flammatory disease affecting multiple aspects of patients` lives. Its epidemiology varies regionally; however, nation-wide epidemiologic data on psoriasis depicting profile of Korean patients has not been available to date. Objective: To understand nationwide epidemiologic characteristics and clinical features of adult patients with psoriasis visited uni-versity hospitals in Korea. Methods: This multicenter, non-in-terventional, cross-sectional study recruited 1,278 adult pa-tients with psoriasis across 25 centers in Korea in 2013. Various clinical data including PASI, BSA, DLQI, SF-36 and PASE were collected. Results: A total of 1,260 patients com-pleted the study (male:female=1.47:1). The mean age was 47.0 years with a distribution mostly in the 50s (24.9%). Early onset (<40 years) of psoriasis accounted for 53.9% of patients. The mean disease duration was 109.2 months; mean body mass index was 23.9 kg/m2; and 12.7% of patients had a family history of psoriasis. Plaque and guttate types of psoriasis accounted for 85.8% and 8.4%, respectively. Patients with PASI ≥10 accounted for 24.9%; patients with body surface area ≥10 were 45.9%. Patients with DLQI ≥6 accounted for 78.8%. Between PASI <10 and PASI ≥10 groups, significant difference was noted in age at diagnosis, disease duration, blood pressure, waist cir-cumference of female, and treatment experiences with pho-totherapy, systemic agents, and biologics. Conclusion: This was the first nationwide epidemiologic study of patients with psoriasis in Korea and provides an overview of the epidemio-logic characteristics and clinical profiles of this patient population. (Ann Dermatol 29(4) 462∼470, 2017)

한국인 건선환자에서 발병하는 질환에 대한 연구 - 다기관 연구

김광호(Kwang Ho Kim),전현진(Hyun Jin Jeon),김광중(Kwang Joong Kim),윤재일(Jai Il Youn),김낙인(Nack In Kim),김태윤(Tae Yoon Kim),최지호(Jee Ho Choi),박기범(Ki Beom Park) 대한피부과학회 2001 대한피부과학회지 Vol.39 No.7

N/A Background: The prevalence of other diseases associated with psoriasis has been investigated in recent years. Objective: This study was performed to see diseases associated with psoriasis in Korea. Methods: From September 1999 to May 2000, a total of 293 patients with psoriasis, who visited the department of dermatology in 6 hospitals, were enrolled in a subject group for the study. We surveyed the incidence rates of associated diseases. Results: In our study, diseases more concomitantly present in patients with psoriasis were dermatophyte infection, seborrhea dermatitis and benign tumor & nevus in skin diseases and obesity, diabetes mellitus, hypertension, gastritis and hepatitis in systemic diseases. Less concomitantly present in-patients with psoriasis were erythroderma, acne, contact dermatitis, atomic dermatitis, bacterial infection, tonsillitis, and internal cancer. Conclusion: Our observations show a distinct pattern of diseases associated with psoriasis in Korea. Further investigation will be mandatory to elucidate concomitant diseases in psoriasis. (Korean J Dermatol 2001;39 (7): 743~748)

돼지에서 정맥, 근육 그리고 경구 투여시의 enrofloxacin의 약물동태학

윤효인,김무열,박승춘,조준형,박병권,이내경,노상석,장범수,신광순,조명행 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

In order to characterize pharmacokinetic profiles according to route of a new enrofloxacin salt form (Enrotil®), it was given to 4 healthy pigs via oral (p.o.), intramuscular (i.m.) or intravenous (i.v.) administrations at a dose rate of 5 ㎎/㎏ body weight. Enrofloxacin (ENFX) in serum was detected by bioassay using E. coli BE1186 as a test organism. The biological elimination half-lives (t_1/2(β)) of ENFX were 6.76±0.99 h (i.v.), 7.16±2.30 h (i.m.) and 11.45±3.90 h (p.o.), Volume of distribution (Vd) of enrofloxacin was 2.20±0.31 L/㎏ (i.v.), 2.52±0.60 L/㎏ (i.m.) and 1.88±0.33 L/㎏ (i.m.). Mean residence time (MRT) was 8.77±1.26 h after i.v. injection and the maximal concentration time (Tmax) following p.o. and i.m. administration was 0.76±0.09 h and 0.60±0.12 h, indicating a rapid absorption from these routes. Bioavailibility (F) was calculated as 64.1% for p.o. administration and 59.71% for i.m. injections. In summary, the newly formulated enrofloxacin salt form has shown a high water solubility, rapid absorption and large tissue distribution, suggesting a potential antibacterials for oral application on a large scale in veterinary sectors.

토끼에서 근육주사시 입자 크기에 따른 amoxicillin의 비교 약물동태학

박승춘,윤효인,오태광,장범수,배순이,조준형,정상희,이내경,김민규 충남대학교 수의과대학 동물의과학연구소 1998 動物醫科學硏究誌 Vol.6 No.-

To investigate the pharmacokinetic difference between the two amoxicillin (AMX) particles in rabbits after intramuscular injection (i.m.), both of AMX-S (particle size: 10 ㎍) and AMX-L (particle size: 100 ㎍) were injected into New Zealand White rabbits (1.2±0.3 ㎏) at a dose rate of 10 ㎎/㎏ of body weight. In this study, serum AMX concentrations were detected by microbiological assay with E. coli BE 1186 which shows high antibiotic sensitivity. After i.m. administration, AMX-S and AMX-L were best fitted as 1-compartment model with the absorption and elimination phase. The biological half-life (T_1/2, _k10) of AMX-S is 4.06±1.09 h and that of AMX-L 4.76±0.69 h. The serum maximal concentration time (T_max) of AMX-S and AMX-L were 0.88±0.17 h and 0.77±0.11 h, respectively. Maximal AMX concentration (C_max) (AMX-S: 5.71±0.62 ㎍/㎖, AMX-L: 5.04±0.25 ㎍/㎖) in serum showed a significant difference (p<0.05). In terms of bioequivalance, however, there was no difference between the two AMX's after i.m. injection in the basis of C_max and AUC.

다양한 함불소가스들의 고비점 용매에 관한 용해도 측정 및 엑막에 의한 분리

최평호,이상학,김철웅,김범식,김광주,이정민,박인준 한국공업화학회 2002 응용화학 Vol.6 No.2

The solubility of various fluoro-gases in high boiling-point solvents, n-Cnh_2n+_1OH(6<n<10)and ionic liquids(+ ions: 1-Buty 1-3-methy1-imidazolium, 1-Ethy1-3-methy1-imidazolium, - ions:BF_4, PF_6, S_6F_6, F_6O_4S_6) were measured at temperatures from 0 to 30℃, at total pressures up to 4 bat Solubility increased significantly with the decrease of n in n-Cn_2N+OH and showed no such a difference in the types of ionic liquids, Especially, the solubility of R22 gas in these solvents increases rapidly with increases in pressure and decreases in temperature, whereas other fluoro-gases were showed a little solubility Liquid-supported membranes were prepared with these solvents and polymer matrix and were applied to the separation of fluoro-gases including R22 gas. A high permeability and selectivity were exhibited in R22 gas against other fluoro-gases.

한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.