Gemifloxacin이 미성숙 랫드의 아킬레스건에 미치는 영향

배진규,김영수,김세은,심경미,강성수,조익현,이수한,박창현,엄창섭,정문진,한송이,임성철,배춘식,Bae, Jin-Gye,Kim, Young-Soo,Kim, Se-Eun,Shim, Kyung-Mi,Kang, Seong-Soo,Cho, Ik-Hyun,Lee, Soo-Han,Park, Chang-Hyun,Uhm, Chang-Sub,Jeong, Moon-Jin,Han 한국현미경학회 2006 Applied microscopy Vol.36 No.2

Gemifloxacin은 대부분의 G(-) 세균들과 G(+) 세균들에 대해 강한 활성을 나타내며 미성숙동물에서 비교적 낮은 연골독성 가능성을 가진 합성 fluoroquinolone계 항생제이다. 본 연구는 미성숙 SD계 랫드의 아킬레스건에 gemifloxacin이 미치는 영향을 평가하기 위해 gemifloxacin을 생후 4주 후부터 0(vehicle), 600mg/kg body weight 용량으로 5일 동안 매일 한번씩 경구투여를 하여 ofloxacin과 비교하였다. 아킬레스건의 형태학적 변화를 투과전자현미경을 이용하여 관찰한 결과 부형제만 처치한 대조군과 비교하였을 때, gemifloxacin과 ofloxacin을 처치한 랫드로부터 채취한 샘플에서 초미세구조의 변화가 관찰되었다. quinolone을 처치한 군의 tenocyte에서는 다양한 퇴행성 변화가 관찰되었고, 세포외기질에서 분리된 세포들이 존재하였는데 이는 ofloxacin을 처치한 그룹에서 특히 높았고 gemifloxacin을 처치한 그룹에서는 매우 낮았다. 따라서, gemifloxacin이 아킬레스건과 같은 결합조직 구조물들의 퇴행성 변화를 보다 적게 야기한다는 것을 보여준다. Gemifloxacin is a synthetic fluoroquinolone antimicrobial agent that exhibits potent activity against most Gram-negative and Gram-positive organisms, and has a comparatively low chondrotoxic potential in immature animals. This study examined the effects of gemifloxacin on the Achilles tendons in immature Sprague-Dawley rats treated by oral intubation once daily for 5 consecutive days from postnatal week 4 onward at doses of 0 (vehicle), and 600mg/kg body weight Ofloxacin was used for comparison. The Achilles tendon sperimens were examined by electron microscopy. In comparison with the vehicle-treated controls, there were ultrastructural changes in all samples from the gemifloxacin- and ofloxacin-treated rats. Degenerative changes were observed in the tenocytes, and the cells that detached from the extracellular matrix were recognizable. The degree of degenerative changes and the number of degenerated cells in the Achilles tendon were significantly higher in the treated group than in the control group. Moreover, among the quinolone treated groups, these findings were more significant in the ofloxacin treated group, and less significant in the gemifloxacin treated group. It is unclear what these findings mean with respect to the possible risk ill juvenile patients treated with gemifloxacin or other quinolones. However, these results show that gemifloxacin causes fewer changes in the connective tissue structures.

Numerical Investigation of Droplet Breakup Effects on Droplet–Wall Interactions Under SLD Conditions

배진규,이관중 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.5

Large droplet dynamics, such as droplet–wall interactions and droplet breakup, have a significant impact on the icing process, under super-cooled large droplet (SLD) conditions. Accordingly, many studies have been conducted to numerically implement the effects of large droplet dynamics on the 2nd generation icing codes. Most of them have focused particularly on droplet–wall interactions, while breakup effects have largely been considered less important. However, considering the larger median volumetric diameter (MVD) regime of SLD conditions, the collection efficiency distribution near the stagnation point can be considerably affected by the breakup effects influencing the droplet–wall interactions. This study numerically investigated the breakup effects on droplet–wall interactions to achieve an improved impingement analysis under SLD conditions. To simulate these effects, a combined large droplet dynamics model was proposed. This model incorporated the breakup model, which estimated the size and velocity of the fragmented secondary droplets, into the droplet–wall interaction model, and it was assumed that all secondary droplets impinge on the surface. Droplet impingement analysis was performed for three geometries of an NACA23012 airfoil (clean, rime-ice, and glaze-ice geometries) under four MVD conditions (52, 111, 154, and 236 μm). As a result, a better prediction of the maximum collection efficiency at the stagnation point was achieved for the cases of clean and rime-ice geometries, although no improvement was observed for the glaze-ice shape case.

경기 남부지역 HACCP 인증 아이스크림 업체와 미인증 업체의 미생물 관리 수준 비교

배진규 ( Jin Gyu Bae ),전오숙 ( Oh Sook Jeon ),박혜원 ( Hye Won Park ),복민순 ( Min Soon Bok ),양호열 ( Ho Yul Yang ),박준조 ( Jun Jo Bark ),고태오 ( Tae Oh Ko ) 한국동물위생학회 2013 韓國家畜衛生學會誌 Vol.36 No.2

The hazard analysis critical control point (HACCP) system was introduced to the Korean livestock slaughter and product processing business in 1997. Ice cream manufacturers focus on the sterilization process in order to reduce microorganism, so the HACCP-accredited ice cream manufacturers particularly set the sterilization process as critical control point (CCP). Therefore, the microbiological test results on the finished products can be considered as one of the indicators which show the level of microbiological control in the ice cream manufacturers. Accordingly, this study was carried out to examine if there is a meaningful difference in terms of the microbiological control level between the HACCP-accredited and non-accredited ice cream manufacturer groups by comparing aerobic plate count (APC) of ice creams. The mean of APC was 1.68 Log CFU/g in the HACCP-accredited ice cream manufacturer group and 2.59 Log CFU/g in the non-accredited ones respectively and there was a statistically significant difference (P<0.05). The test results suggest that the level of microbiological control in the HACCP-accredited ice cream manufactures is much higher than that of non-accredited ones.

SLD 조건에서 착빙 해석 정확도 개선을 위한 Wall-Droplet Interaction 수치 모델링 및 Deformation 모델 비교 연구

배진규(Jinkyu Bae),이관중(Kwanjung Yee) 한국항공우주학회 2020 韓國航空宇宙學會誌 Vol.48 No.4

SLD 조건은 직경이 50μm 이상인 과냉각대형액적의 분포가 지배적인 결빙 환경을 뜻한다. SLD 조건에서는 액적의 큰 크기로 인해 wall-droplet interaction, deformation 등의 물리적 현상이 착빙 과정에 중요한 영향을 미친다. 그에 따라 SLD 효과를 수치적으로 모사하기 위한 다양한 연구가 수행되었고, 부착률을 수정하는 후처리 기법을 통해 wall-droplet interaction 현상을 고려하는 방법이 제안되었다. 그러나 이 방법은 액적이 충돌하는 벽면 특성을 제대로 고려하지 않는 반경험식 (Wright Model)을 사용하기 때문에 착빙 영역에서 여전히 부착률과 부착 한계를 과대 예측한다. 이 문제를 해결하기 위해 본 연구에서는 착빙 영역을 세 개의 영역으로 구분하였다. 그리고 벽면 특성을 고려하는 Bai and Gosman rebound 모델을 바탕으로 개발한, 새로운 wall-droplet interaction 모델을 후처리 기법에 도입했다. 그리고 액적의 항력계수를 증가시키는 deformation 현상을 반영하기 위해 3가지 deformation 모델을 비교·분석하여 가장 적합한 모델을 선정했다. 앞의 내용을 바탕으로 개발한 SLD 결빙 예측 코드를 검증하기 위해 실험 데이터를 활용하여 해석을 수행했다. 그 결과 수정된 후처리 기법은 착빙 영역에서 rebound 현상에 의한 부착률 감소를 더욱 크게 예측하였고 부착 한계와 부착률 크기를 예측하는 데 있어 향상된 정확성을 보여줬다. 그리고 deformation에 의한 항력계수의 증가를 가장 크게 결정하는 Wiegand model이 실험과 가장 유사한 것을 확인할 수 있었다. Under SLD conditions, due to the large size of droplets, physical phenomena such as wall-droplet interaction and deformation have a significant effect on the icing process. Accordingly, many studies have been conducted in order to computationally simulate SLD effects. As one of the efforts, post-processing method have been proposed to describe wall-droplet interaction effect, which modified collection efficiency using Wright model. However, since the model doesn’t properly consider the wall condition, it still overestimated collection efficiency and impingement limit. To solve this problem, impingement areas were divided into 3 different regions, and the post-processing method was introduced with the new wall-droplet interaction model developed based on Bai and Gosman rebound model. In order to consider the effect of deformation, the most suitable model was selected by comparing the deformation models used in the various icing codes. As a result, the modified post-processing method showed improved accuracy in predicting the impingement limits and collection efficiency by further estimating mass flux loss due to rebound, and it was observed that the result was the closest to the experimental data when the deformation effect was included by using Wiegand model.

SLD 조건에서 착빙 해석 정확도 개선을 위한 Wall-Droplet Interaction 수치 모델링

배진규(Jinkyu Bae),이관중(Kwanjung Yee) 한국항공우주학회 2020 한국항공우주학회 학술발표회 논문집 Vol.2020 No.7

발전소의 소음 저감을 위한 LMS 알고리즘을 이용한 능동소음제어

배진규(Jin-Kyu Bae),아미나(Mi-Na A),이권순(Kwon S. Lee) 대한전기학회 2014 대한전기학회 학술대회 논문집 Vol.2014 No.7

오토폼을 이용한 돼지 뒷다리 중량예측 연구

배진규 ( Jin-gyu Bae ),이영규 ( Young-kyu Lee ),박범영 ( Beom-young Park ),임효선 ( Hyo-seon Lym ),정봉수 ( Bong-su Jung ) 한국동물위생학회 2016 韓國家畜衛生學會誌 Vol.39 No.1

The Autofom is a equipment for predicting the amount of pig carcasses meat using the 16 ultrasonic sensors to measure in real time and it was established in Dodram LPC in Gyeonggi Province of Korea for the first time. This study was carried out to validate the reliability of Autofom statistically and to establish guideline for developing a analytic formula through comparing the measurement between Autofom and dissection. The ham parts of sixty-six pig carcasses were measured with Autofom and by two experimental performers. The weight means and standard deviations of ham parts including bone by measurements with Autofom and dissection were 10.69±0.81 kg and 10.77±0.94 kg, respectively a strong positive correlation (P<0.01) was identified, with a coefficient of determination (R2) of 0.82. The weight means and standard deviations of lean ham parts by measurements with Autofom and dissection were 7.41±0.58 kg and 7.42±0.89 kg, respectively a strong positive correlation (P<0.01) was identified, with a coefficient of determination (R2) of 0.72. The root mean square errors of two groups were 0.40 and 0.50, respectively.

강설과 눈 비산 상황에 따른 고속열차의 착설에 대한 수치적 비교 연구

손순호(S. Shon),배진규(J. Bae),이관중(K. Yee) 한국전산유체공학회 2022 한국전산유체공학회지 Vol.27 No.1

The accumulation of snow on train bogies hinders the smooth operation of important parts, degrading the safety of the vehicle. This is primarily due to snowfall and snow saltation from the ground. This study conducted a comparative study on the snow accumulation of high-speed trains due to snowfall and snow saltation conditions. To describe the movement of the snow, we adopted the Eulerian method which consists of continuity and momentum equations for snow density. Additionally, the process of snow saltation was described by implementing the semi-empirical model into a boundary condition. As a result, the snow accumulation on the train showed different trends in the snowfall and snow saltation conditions. The amount of snow accumulation decreased toward the rear of the train in snowfall conditions, but it showed a tendency to increase toward the rear in snow saltation conditions.

돼지에서 구제역 백신 접종 후 항체가 변화 조사

안길호 ( Gil Ho Ahn ),배진규 ( Jin Gyu Bae ),정광 ( Kwang Jung ),왕영일 ( Young Il Wang ),정준용 ( Jun Yong Jung ),강순근 ( Soon Keun Kang ),권혁무 ( Hyuk Moo Kwon ) 한국동물위생학회 2013 韓國家畜衛生學會誌 Vol.36 No.1

Three serotypes (O+A+Asia1 type) of the foot-and-mouth disease (FMD) vaccine were injected into cloven-hoofed animals in Korea after the nationwide spread of FMD at the end of 2010. This study was conducted to investigate FMD antibody development after FMD vaccination, and to determine whether there was a significant correlation between the antibody titer of the sow and the antibody titer of the growing pigs. The antibody titer (percentage inhibition [PI] titer) of the sow (gilt) after FMD vaccination was maintained at a level higher than 50 (P<0.05) for 5 months. A higher PI titer for the 1-month-old growing pigs corresponded with greater inhibition of the PI titer of the vaccinated growing pigs (P<0.05). A negative correlation (P<0.05) between the PI titer of the 1-month-old growing pigs and the PI titer of 3-month-old growing pigs, 4-month-old growing pigs after FMD vaccination at 2 months, 3months was identified, with a coefficient of determination (R2) of 0.274. Thus the PI titer of the growing pigs was inhibited to a greater degree when vaccination was performed at 2 months of age than at 3 months. However, many other factors likely influence growing pigs` PI titer in addition to the PI titer of the sow and age at vaccination, given that the coefficient of determination was somewhat lower.

복합재료 블레이드 단면 해석 프로그램(Ksec2d-AE)의 신뢰성 검증

배재성(Jae-Seong Bae),김현식(Hyun-Sik Kim),배진규(Jin-Kyu Bae),임태현(Tae-Hyun Lim),황재민(Jae-Min Hwang),정성남(Sung Nam Jung) 한국항공우주학회 2018 韓國航空宇宙學會誌 Vol.46 No.4

본 연구에서는 유한요소법 기반의 단면 특성치 해석 프로그램인 Ksec2d-AE의 정확성을 검증함으로써, 학부 수준의 비행체 구조해석 및 설계 시 활용가능성을 제시하고자 한다. 이를 위해 다양한 요소를 적용하여 Ksec2d-AE 로부터 계산된 단면강성계수 결과에 대한 유한요소의 수렴성을 확인하였다. 또한 Ksec2d-AE로부터 구한 단면강성계수를 상용 구조해석 프로그램인 MSC NASTRAN 으로부터 구한 강성계수와 비교하고, 주요 공학적 중심치(인장 중심, 전단 중심, 주 굽힘축)의 특성에 부합하게 구조물이 거동하는지 확인함으로써 Ksec2d-AE의 단면강성계수 및 중심치 결과를 검증하였다. 본 연구를 통하여 Ksec2d-AE 프로그램의 유용성을 확인하였다. In this study, the accuracy and efficiency of a composite rotor blade cross-section analysis program, Ksec2d-AE, which is available at an educational web-based platform called EDISON-CSD, are assessed for possible use in undergraduate structural analysis projects. To this purpose, the convergence of cross-sectional constants by varying the number of finite elements in the cross-section of a wind turbine blade is investigated. The stiffness constants along with the cross-sectional engineering offsets obtained using Ksec2d-AE are validated against a 3D finite element analysis program MSC NASTRAN.