Antimicrobial Resistance Profile of Acinetobacter spp. Isolates from Retail Meat Samples under Campylobacter- Selective Conditions

( Min-hyeok Cha ),( Sun Hee Kim ),( Seokhwan Kim ),( Woojung Lee ),( Hyo-sun Kwak ),( Young-min Chi ),( Gun-jo Woo ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5

Acinetobacter strains are widely present in the environment. Some antimicrobial-resistant strains of this genus have been implicated in infections acquired in hospitals. Genetic similarities have been reported between Acinetobacter strains in nosocomial infections and those isolated from foods. However, the antimicrobial resistance of Acinetobacter strains in foods, such as meat, remains unclear. This study initially aimed to isolate Campylobacter strains; instead, strains of the genus Acinetobacter were isolated from meat products, and their antimicrobial resistance was investigated. In total, 58 Acinetobacter strains were isolated from 381 meat samples. Of these, 32 strains (38.6%) were from beef, 22 (26.5%) from pork, and 4 (4.8%) from duck meat. Antimicrobial susceptibility tests revealed that 12 strains were resistant to more than one antimicrobial agent, whereas two strains were multidrug-resistant; both strains were resistant to colistin. Cephalosporin antimicrobials showed high minimal inhibitory concentration against Acinetobacter strains. Resfinder analysis showed that one colistin-resistant strain carried mcr-4.3; this plasmid type was not confirmed, even when analyzed with PlasmidFinder. Analysis of the contig harboring mcr-4.3 using BLAST confirmed that this contig was related to mcr-4.3 of Acinetobacter baumannii. The increase in antimicrobial resistance in food production environments increases the resistance rate of Acinetobacter strains present in meat, inhibits the isolation of Campylobacter strains, and acts as a medium for the transmission of antimicrobial resistance in the environment. Therefore, further investigations are warranted to prevent the spread of antimicrobial resistance in food products.

S-536 The Effect of PTD-mediated BMP-7 on EMT in Peritoneal Mesothelial Cells

( Min-uk Cha ),( Seonghun Kim ),( Bo Young Nam ),( Hye-young Kang ),( Jae Eun Um ),( Ji Min Park ),( Meiyan Wu ),( Jung Tak Park ),( Seung Hyeok Han ),( Shin-wook Kang ),( Tae-hyun Yoo ) 대한내과학회 2016 대한내과학회 추계학술대회 Vol.2016 No.1

Objective:?We investigated the effect of PTD-mediated BMP-7 (tissue-regeneration polypeptide 2, TRP2) on TGF-β1-induced EMT in cultured human peritoneal mesothelial cells (HPMCs). In addition, we investigated how to deliver the drugs to peritoneum in vivo models. Design and Method:?In vitro, HPMCs were cultured in M199 media containing 5.6 mM glucose (normal glucose, NG), NG + TGF-β1 (2 ng/ml) with or without TRP2 (100 ng/ml). After 72 hours, cells were harvested. In vivo, PD rat-O-port inserted into 11 Sprague-Dawley rats, and saline (control group, n=3), 4.25 % PD solution (PD group, n=3) or 4.25 % PD solution + TRP2 (PD + TRP2 group, n=5) were infused for 4 weeks. After 4 weeks, rats were sacrificed and the peritoneal tissues were removed. E-cadherin, ZO-1, α-smooth muscle actin (α-SMA), snail, vimentin, type I collagen, and fibronectin protein expression in HPMCs and the peritoneum were estimated by western blot analysis, and fibronectin expression was evaluated by immunohistochemistry staining. PF was assessed by Masson’s trichrome (MT) staining. Results:?In vitro, protein expression of E-cadherin and ZO-1 (epithelial marker) were significantly decreased, while α-SMA, snail, vimentin (mesenchymal marker), type I collagen and fibronectin were significantly increased in TGF-β1-stimulated HPMCs compared to control group, and these changes were significantly improved by TRP2 treatment. In vivo, peritoneal EMT and PF were significantly increased in PD rats compared to control rats. The thickness of mesothelial layer and the intensity of MT staining in the peritoneum of PD rats were also significantly higher compared to control rats. These changes of the peritoneum in PD rats were significantly ameliorated by the administration of TRP2. Conclusions:?This study suggests that TRP2 directly inhibits the process of TGF-β1-induced PF via peritoneal EMT in HPMCs. In addition, TRP2 mitigates PF in PD rats. The effect of PTD-mediated recombinant protein delivery system may be a potential therapeutic strategy for prevention of PF in PD patients.

Machining feature recognition using BRepNet

Min Hyeok Cha,김병철 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.12

Numerous attempts have been made to recognize the machining features in three-dimensional (3D) computer-aided design (CAD) models using various methods since the 1980s. Recently, deep learning approaches have been explored for machining feature recognition. However, the boundary representation (BRep) model, the most common representation of 3D CAD models, is difficult to use directly in deep learning because of its complex structure. To solve this problem, BRepNet was recently proposed. This study proposes a method for recognizing machining features in 3D CAD models represented by BRep using BRepNet. In the proposed method, BRepNet is used to classify each face of a 3D CAD model based on the machining features. Next, the classified faces are combined into machining features using connected-component analysis. In addition, a dataset is generated to train the BRepNet model. Subsequently, the proposed method is implemented and tested for verification. The proposed method exhibits an accuracy of 96.03 % and part intersection over union (pIoU) of 90.57 %.

자동차 Anti-trap Power Window Lift Controller 설계

차민혁(Min-Hyeok Cha),김학련(Hak-Lyun Kim),이주(Ju Lee) 대한전기학회 2001 대한전기학회 학술대회 논문집 Vol.2001 No.10

근전도 바이오피드백을 이용한 숏 풋 운동이 정적으로 선 자세 동안 발의 안쪽 세로활 유지에 미치는 영향

차상민(Sang-min Cha),강민혁(Min-hyeok Kang),문동철(Dong-chul Moon),오재섭(Jae-seop Oh) 한국전문물리치료학회 2017 한국전문물리치료학회지 Vol.24 No.1

Background: Short foot exercise (SFex) is often prescribed and performed in the sport and rehabilitation fields to strengthen intrinsic foot muscles. However, SFex is difficult to perform because of lack of feedback methods. Objects: The aim of this study was to compare the effects of SFex with and without electromyography (EMG) biofeedback on the medial longitudinal arch (MLA) of healthy individuals who maintained a static standing position. Methods: All participants (14 males and 12 females) were randomly divided into two groups(biofeedback and non-biofeedback groups). The EMG activity of the abductor hallucis (AbdH) and tibialis anterior (TA) and the MLA angle on the dominant leg side were measured with the participant in the standing position in the pre- and post-intervention conditions. The intervention session consisted of 15 minutes of SFex with (biofeedback group) or without (non-biofeedback group) EMG biofeedback. The groups were compared using two-way repeated measures analysis of variance. Results: The post-intervention activities of the AbdH muscle (p<.05) and the AbdH/TA ratio (p<.05) were significantly greater in the biofeedback group than in the non-biofeedback group. The activity of the TA (p<.05) and the MLA angle (p<.05) in the biofeedback group were significantly lower in the post-intervention condition than in the pre-intervention condition. Conclusion: The present findings demonstrate that the combination of SFex and EMG biofeedback can effectively facilitate the muscle activity of the AbdH and strengthen the medial longitudinal arch.

A large reduction in switching current in W/CoFeB heterostructures with W–N interfacial layers

Min Hyeok Lee,Yong Jin Kim,Gyu Won Kim,Taehyun Kim,In Ho Cha,Quynh Anh T. Nguyen,Sonny H. Rhim,Young Keun Kim 한국자기학회 2020 한국자기학회 학술연구발표회 논문개요집 Vol.30 No.2

Thickness-dependent spin-orbit torques in normal metal/Nb/ferromagnet tri-layers

Min Hyeok Lee,Gyungchoon Go,Yong Jin Kim,In Ho Cha,Gyu Won Kim,Taehyun Kim,Kyung-Jin Lee,Young Keun Kim 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.2

When electrical current flows to normal metal (NM)/ferromagnet (FM) heterostructures, a transverse spin current that exerting torque to the magnetization is generated. This torque, called spin-orbit torque (SOT), is drawing massive attention due to its applicability for the energy-efficient writing method of a next-generation memory device. For the application of SOT to memory or logic devices, it is crucial to quantify the mechanisms of this new physical phenomenon. Most SOT studies designed the simple NM/FM bilayer structures where NM (or NM/FM interface) serves as spin current source. Recently, the experimental system has been improved to more complicate structures containing more than one source [5, 6]. This study discussed the thicknessdependent SOT efficiency in NM/Nb/FM tri-layer structures where either NM1/NM2 or NM/FM bilayer serves as an additional spin current source. We investigate two types of NM/Nb/CoFeB tri-layer in which the NM was either Ta or Pt. The SOT value increased and saturated with increasing the Nb thickness in both series. However, there is switching polarity reversal in Pt/Nb/FM structures due to the different spin-orbit coupling signs between Pt and Nb when tNb changed around critical thickness. In contrast, there would be no such reverse in the Ta/Nb/FM structure. We confirm this polarity reversal behavior by both second harmonics and current-induced SOT switching measurements, suggesting well-designed systematical observation of the thickness dependence of SOT. These results provide a systematic understanding of the thickness-dependent SOT properties.

압축코팅법에 의한 3단계 약물방출형 지속성제제의 제조 및 용출특성

민신홍,권종원,양중익,차봉진,권혁노,김철수 한국약제학회 1992 Journal of Pharmaceutical Investigation Vol.22 No.2

A novel oral controlled release tablet which may offer more uniform drug level in the body than simple zero-order was developed. The tablet is composed of three layers; outer film layer, middle part compression-coated hydroxypropylmethylcellulose (HPMC) matrix layer, and inner core layer. Each layer contains nicardipine HCl as a model drug. In vitro dissolution test showed that the tablet released the drug in clear three steps; a rapid initial release, followed by a constant rate of release, and then a second phase of fast release of drug. The dissolution characteristics could be modified easily by changing the grade of HPMC, thickness of matrix layer, content of methylcellulose in matrix layer, content of active ingredient in each layer. The pH of dissolution medium did not affect the release profile. This three-step release system is expected to raise the blood concentration rapidly to effective level and to maintain effective blood level longer than simple slow-release systems.

Observation of spin-current transport in normal metal/Nb/ferromagnet tri-layers

Min Hyeok Lee,Gyungchoon Go,Yong Jin Kim,In Ho Cha,Gyu Won Kim,Taehyun Kim,Kyung-Jin Lee,Young Keun Kim 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1

Spin-orbit torque (SOT) is drawing attention because it is applicable for the writing method of a brand-new memory device that is energy efficient and non-volatile. When electrical current is induced to normal metal (NM)/ferromagnet (FM) heterostructures, a transverse spin current is generated. An angular momentum transferred to magnetization by the generated spin current acts as a torque [1]. For the application of SOT to memory or logic devices, it is crucial to investigate the mechanisms of this new physical phenomenon. Many researchers had employed the experiment varying the NM thickness based on the NM/FM bi-layer structure to unveil the origin [2-4]. In this system, NM (or NM/FM interface) plays a single spin current source. However, to enhance the SOT efficiency, the experimental system has been improved to tri-layer structures containing more than one source [5, 6]. This study would like to discuss how the thickness dependence of SOT efficiency behaves in NM/Nb/FM tri-layer structures where either NM1/NM2 or NM/FM bilayer act as an additional spin current source. The SOT efficiency decreased as the Nb thickness (t_Nb) increased in Ta 3/Nb t_Nb/CoFeB 0.9 structure. This result suggested that the thicker Nb layer suppressed the spin current, which was generated from Ta (or Ta/Nb), from reaching the FM layer. However, in the Pt/Nb/CoFeB series in which Pt with a different SOC sign from Ta and Nb was employed, the behavior of SOT efficiency is different. When t_Nb ≤ 3 nm, the device showed a positive signal but negative for t_Nb > 3 nm. The current-induced SOT switching also confirmed this sign reversal, which showed a well-designed experiment. These results provide a systematic understanding of the thickness-dependent SOT properties.

고융점희유금속의저온소결방법

( Sang Hyeok Im ),( Dong Hwan Kim ),( Young Hoon La ),( Nam Jin Kim ),( Cha Won Hwang ),( Jae Min Cha ),( Bong Ki Ryu ) 대한금속재료학회 ( 구 대한금속학회 ) 2010 재료마당 Vol.23 No.3

This study looks at crystallization and sintering behavior in B2O3 containing Li2O-Al2O3-SiO2 glass powder. The sintered sample was produced with glass powders measuring 44 μm. The relative density and transmittance of the sintered samples showed the highest value at the temperature of 650°C. At temperatures higher than 650°C, crystal growth occurred to decrease the densification of B2O3-Li2O-Al2O3-SiO2 (BLAS) glass powder. The main crystalline phase in the glass powder was a-spodumene. From non-isothermal differential thermal analysis, the crystallization of particles (Φ=44 μm) was observed at 640°C to 684°C with respect to the heating rate. The activation energy of crystallization (E(C)) and the Avrami constant (n) calculated by Kissinger and Ozawa equations indicated that the surface and the bulk crystallization occurred simultaneously in the glass. The optimum sintering temperature of this glass powder was 650°C without crystal growth of β-spodumene, although nucleation or nano-crystal growth occurred.