Purification and Characterization of Helicobacter pylori ${\gamma}$-Glutamyltranspeptidase

Song, Jae-Young,Choi, Yeo-Jeong,Kim, Jeong-Min,Kim, Yoo-Ree,Jo, Jin-Seong,Park, Jin-Sik,Park, Hee-Jin,Song, Yun-Gyu,Lee, Kon-Ho,Kang, Hyung-Lyun,Baik, Seung-Chul,Youn, Hee-Shang,Cho, Myung-Je,Rhee, Kw The Korean Society for Microbiology 2011 Journal of Bacteriology and Virology Vol.41 No.4

Gamma-glutamyltranspeptidase (GGT) was purified to electrophoretic homogeneity from the cell extract of H. pylori. The purified enzyme consisted of heavy and light subunits with molecular weights of 38 kDa and 21 kDa, respectively. N-terminal amino acid sequence of heavy and light subunits revealed that H. pylori GGT was processed into 3 parts for a signal peptide of 27 amino acid residues, a heavy subunit of 352 residues, and a light subunit of 188 residues during translation. The reaction rate for hydrolysis of ${\gamma}$-GpNA was 84.4 ${\mu}mol/min$ per milligram of protein, and that for the ${\gamma}$-glutamyl transfer from ${\gamma}$-GpNA to gly-gly was 23.8 ${\mu}mol/min$ per milligram of protein. The apparent Km values of H. pylori GGT for ${\gamma}$-glutamyl compounds were on the order of $10^{-3}$ to $10^{-4}$ M and those for acceptor peptides and amino acids were on the order of $10^{-1}$ to $10^{-2}$ M. The GGT protein kept approximately 80% of the initial enzymatic activity on incubation at $60^{\circ}C$ for 15 min. The optimum temperature and pH for reactions of both hydrolysis and transpeptidation were $40^{\circ}C$ and 9.0, respectively. The transpeptidation and hydrolysis reactions catalyzed by H. pylori GGT were strongly inhibited by L-Gln and moderately inhibited by L-Ala, L-Ser, ${\beta}$-chloro-L-Ala, and L-Glu. These results demonstrated that the biochemical properties of H. pylori GGT are different from those of other bacterial GGTs. Further, H. pylori GGT might degrade glutathione in the gastric mucous layer of humans if the enzyme could be secreted in the bacterial niches.

18–30세 사이에 발생하는 뇌경색의 특징, 다기관 레지스트리 연구

장윤경,송태진,김용재,허지회,이경열,김영은,장민욱,조수진,강석윤 이화여자대학교 의과학연구소 2017 EMJ (Ewha medical journal) Vol.40 No.3

Objectives: Although there have been several reports that described characteristics for young age stroke, information regarding very young age (18–30 years old) has been limited. We aimed to analyze demographic factors, stroke subtype, and 3-month outcome in acute ischemic stroke patient who have relatively very young age in multicenter stroke registry. Methods: We evaluated all 122 (7.1%) consecutive acute ischemic stroke (within 7 days after symptom onset) patients aged 18 to 30 from 17,144 patients who registered in multicenter prospective stroke registry, 1997 to 2012. Etiology was classified by Trial of Org 10172 in Acute Stroke Treatment criteria. Stroke severity was defined as National Institutes of Health Stroke Scale (NIHSS) and stroke outcome was defined by modified Rankin scale (mRS) at 3 months after index stroke. Results: The mean age of all included patients was 25.1±3.7 years and 76 patients (62.2%) were male. The median NIHSS at admission was 4. Considering stroke subtype, 37 patients (30.3%) had stroke of other determined etiology (SOD), 37 (30.3%) had undetermined negative evaluation (UN) and 31 (25.4%) had cardioembolism (CE) were frequently noted. After adjusting age, sex and variables which had P<0.1 in univariable analysis (NIHSS and stroke subtype), CE stroke subtype (odds ratio, 4.68; 95% confidence interval, 1.42–15.48; P=0.011) were significantly associated with poor functional outcome (mRS≥3). Conclusion: In very young age ischemic stroke patients, SOD and UN stroke subtype were most common and CE stroke subtype was independently associated with poor discharge outcome.

Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells

Min-Seung Choi,Young-Ju Lee,Jung-Dae Kwon,Yongsoo Jeong,Ju-Yun Park,강용철,Pung Keun Song,Dong-Ho Kim 한국물리학회 2013 Current Applied Physics Vol.13 No.8

We investigated the effects of hydrogen plasma treatment on the physical and electrical properties of fluorine-doped tin oxide (FTO) films used for amorphous silicon (a-Si) thin film solar cells. A slight increase in carrier concentration by the hydrogen doping effect was observed for the FTO film exposed to the hydrogen plasma for 5 min. For further exposure to the plasma, the chemical reduction became prominent and resulted in deterioration of the electrical and optical properties of the film. XPS analysis revealed that the chemical reduction of SnO2 to Sn metallic state occurs on the surface region. It was found that the defects formed by hydrogen plasma act as recombination centers at the interface between FTO electrode and p-layer of a-Si solar cells. This phenomenon resulted in the deterioration of the cell performance. The averaged conversion efficiency (6.82%) of the cells on pristine FTO hydrogen substrate was decreased to 5.81% for the cells on FTO treated for 5 min, which is mainly attributed to the decrease in short-circuit current density.

Elastic properties and equation of state for polycarbonate by high-pressure Brillouin spectroscopy

Young-Ho Ko,Jinhyuk Min,Jonghyun Song 한국물리학회 2016 Current Applied Physics Vol.16 No.3

Although the conventional vibrational spectroscopic techniques of Raman and infrared spectroscopy are generally used to analyze the material properties of polymers, the physical and mechanical information that can be obtained through these techniques is very scarce. Since elastic information and equation of state are important for the application of polymers, we carried out Brillouin spectroscopy coupled with a diamond anvil cell. The pressure dependence of elastic properties for an amorphous polycarbonate with and without pressure medium was investigated for pressure up to 11 GPa. A substantial collapse of free volume under the anisotropic pressure was ascertained with the different slopes of elastic constants, Young's moduli, and bulk moduli at low and high pressures. From the Brillouin frequency shifts, we extracted C11 and C12 elastic constants, Young's moduli, shear moduli, bulk moduli, Poisson's ratios, and their pressure dependences. PeV isotherms were then constructed and fitted to two semi-empirical equations of state to extract the isothermal bulk modulus and its pressure derivative.

LDPC 부호의 복호를 위한 양자화 성능과 반복 횟수 통계

서영동(Young-Dong Seo),공민한(Min-Han Kong),송문규(Moon-Kyou Song) 대한전자공학회 2008 電子工學會論文誌-TC (Telecommunications) Vol.45 No.-

LDPC 복호기의 성능과 하드웨어 복잡도는 양자화 과정의 설계 변수인 클리핑 임계치(clipping threshold) cth와 양자화 비트 수 q, 그리고 복호과정의 최대 반복 횟수에 의존한다. 본 논문에서는 이상적인 Min-Sum 알고리즘과 양자화된 Min-Sum 알고리즘을 비교하기 위해서 시뮬레이션을 통해 클리핑 임계치 cth와 양자화 비트 수 q에 따른 LDPC 부호의 비트 오율 성능을 평가하였다. 시뮬레이션 결과 클리핑 임계치 cth = 2.5, 양자화 비트 수 q = 6일 경우에 이상적인 Min-Sum 알고리즘에 가장 근접한 비트 오율이 나타남을 확인할 수 있었다. 또한 반복 횟수의 통계적 분석을 통한 반복 횟수의 확률 밀도 함수를 이용하여 q와 반복 횟수에 따른 복호 복잡도를 계산하고, 부호어 에러율(word error rate; WER) 성능을 추정하였다. 이상의 결과는 LDPC 복호기 설계에서 부호의 성능과 복호 복잡도 사이의 절충을 위해 사용될 수 있다. The performance and hardware complexity of LDPC decoders depend on the design parameters of quantization, the clipping threshold cth and the number of quantization bits q, and also on the maximum number of decoding iterations. In this paper, the BER performances of LDPC codes are evaluated according to the clipping threshold cth and the number of quantization bits q through the simulation studies. By comparing the quantized Min-Sum algorithm with the ideal Min-Sum algorithm, it is shown that the quantized case with cth = 2.5 and q = 6 has the best performance, which approaches the idea case. The decoding complexities are calculated and the word error rates (WER) are estimated by using the pdf which is obtained through the statistical analyses on the iteration numbers. These results can be utilized to tradeoff between the decoding performance and the complexity in LDPC decoder design.

An automated quality assurance system with deep learning for small cube-ball phantom localization in noisy megavoltage images

Park Min-Jae,Lee Gyemin,Kwak Jungwon,Jeong Chiyoung,Goh YoungMoon,Kim Sung-woo,Cho Byungchul,Song Si Yeol,Kim Jong Hoon,Jung Jinhong,Shin Young Seob,Oh Jungsu 한국물리학회 2024 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.84 No.9

To enhance effi ciency and minimize errors, we automated the quality assurance (QA) process in radiation oncology, specifi - cally laser localization. Additionally, we explored the use of a convolutional neural network (CNN) to enhance the detection of small cube-ball phantoms in noisy images. Laser localizations were measured manually on the acquired images. To automate the QA workfl ow, we developed a Linux server equipped with database and web servers. Digital Imaging and Communications in Medicine (DICOM) fi les were retrieved 40 times for 10 linear accelerators (LINACs). The center of the cube-ball phantoms was estimated through Gaussian fi tting. We applied CNN using 6,968 stored results to improve the estimation performance in noisy megavoltage (MV) images. Subsequently, both analysis time and accuracy were compared. Our hospital has been employing the automated QA system since 2018, notably reducing the time for laser localization from 30 min to just 1 min. The average and standard deviation (SD) of inter-observer variability in the X- and Y-axes were 0.06 ± 0.01 mm and 0.05 ± 0.01 mm, respectively. Absolute diff erences between manual assessment and Gaussian fi tting presented average and SD values of 0.40 ± 0.51 mm and 0.23 ± 0.24 mm, respectively. In contrast, absolute diff erences between manual assessment and CNN presented average and SD values of 0.12 ± 0.10 mm and 0.11 ± 0.09 mm, respectively. Overall, the automated QA system signifi cantly hastened procedures in our large hospital and improved the estimation of the cube-ball phantom’s position in noisy images through deep learning.

디지털 음악 및 아날로그 음악이 악력에 미치는 영향 평가

최민지 ( Min Ji Choi ),홍지혜 ( Ji Hye Hong ),송영웅 ( Young Woong Song ) 대구가톨릭대학교 자연과학연구소 2011 자연과학연구논문집 Vol.9 No.1

This study evaluated the effect of the music type (analog and digital) on the grip strength. Five male and five female healthy college students participated in the experiment. The independent variables were music type (analog, digital, no music) and listening time (5 min., 10 min., and 15 min.). The classic LP disc was used as the analog music and the LP was converted to mp3 to make the digital music source. Grip forces were measured every 5 minutes until 15 minutes using Jamar strain guqge. Mean forces and peak forces were used as dependent variables. The analysis of variance showed that there was no difference between analog and digital music (p>0.05). Only, the gender effect was statistically significant (p<0.05). These results should be verified using different types of music (not only classical music) or preferred music, during different listening time duration (>15 minutes).

Energy storage capabilities of nitrogen-enriched pyropolymer nanoparticles fabricated through rapid pyrolysis

Yun, Young Soo,Kim, Yu Hyun,Song, Min Yeong,Kim, Na Rae,Ku, Kyojin,An, Ji Su,Kang, Kisuk,Choi, Hyoung Jin,Jin, Hyoung-Joon Elsevier 2016 Journal of Power Sources Vol.331 No.-

<P><B>Abstract</B></P> <P>Nanostructured pyropolymers contain significant amounts of redox-active heteroatoms, have high specific surface areas, and a defective carbon microstructure, indicating good potential for pseudocapacitive charge storage. In this study, nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) are fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>. N-PNs-50 exhibit a nitrogen content of 9.8 wt%, a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>, and an amorphous carbon structure with an I<SUB> <I>D</I> </SUB>/I<SUB> <I>G</I> </SUB> intensity ratio of 0.95. These unique characteristics lead to good electrochemical performances, in which reversible capacities of 660 and 255 mAh g<SUP>−1</SUP> are achieved for Li-ion and Na-ion storage, respectively, with favorable voltage characteristics (<1.5 V for Li-ions and <1.2 V for Na-ions). This study provides a more feasible production method for nitrogen-doped pyropolymers and their practicable electrochemical performances for use as an anode in energy storage devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanostructured pyropolymers (N-PNs-50) were fabricated by rapid pyrolysis. </LI> <LI> N-PNs-50 exhibited a nitrogen content of 9.8 wt% and amorphous carbon structure. </LI> <LI> N-PNs-50 exhibited a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>. </LI> <LI> 660 and 255 mAh g<SUP>−1</SUP> were achieved for Li-ion and Na-ion storage, respectively. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) were fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>, showing superior electrochemical performances.</P> <P>[DISPLAY OMISSION]</P>

기계적 자극을 이용한 인체 중간엽줄기세포로부터 유사-섬유모세포로의 분화 유도

최경민 ( Kyung Min Choi ),서영권 ( Young Kwon Seo ),윤희훈 ( Hee Hoon Yoon ),권순용 ( Soon Yong Kwon ),이화성 ( Hwa Sung Lee ),박용순 ( Yong Soon Park ),손영숙 ( Young Sook Son ),송계용 ( Kye Yong Song ),김영진 ( Young Jin Kim 한국조직공학과 재생의학회 2006 조직공학과 재생의학 Vol.3 No.4

Recently, in vitro reconstruction of anterior cruciate ligament(ACL) has been tried using tissue engineering technique, especially mesenchymal stem cell(MSC) is considered as a good cell source. In this study, we tried to find the effect of mechanical stimulus on the differentiation of bone marrow-derived MSC into ACL fibroblastlike cell using a cell training bioreactor imposing cyclic mechanical tension whose parameters were 120 min/day, 1 Hz, and 5% strain. After 2 weeks of culture, MSCs under cyclic tension showed more regularly oriented alignment and lower expression of CD73 and CD105 than control by microscopy and FACS analysis. In transcriptional level, type I collagen, type II collagen, fibronectin, elastin, α-smooth muscle actin mRNA expressions of MSCs under cyclic tension were higher than control and similar to native ACL. In conclusion, it is thought that mechanical cyclic tension induced the loss of stemness of MSC, therefore improved the differentiation into ACL fibroblast-like cell.

옥수수 바이오매스를 함유한 폴리에스터 필름의 물리 화학적 특성과 생분해 특성에 대한 콜드 플라즈마 처리의 영향

송아영(Ah Young Song),오윤아(Yoon Ah Oh),오세준(Se Jun Oh),민세철(Sea Cheol Min) 한국식품과학회 2015 한국식품과학회지 Vol.47 No.2

CP 처리의 CBPE 필름의 물리화학적 특성 및 생분해 특성에 대한 영향을 연구하였다. CP 처리는 CBPE 필름의 인장 강도, 신장률, 그리고 광투과도와 같은 물리적 특성에는 영향을 주지 않았으나, air-CP 처리는 CBPE 필름의 유연성, 수분 방벽 특성, 그리고 인쇄적성을 향상시켰다. Air-CP 처리는 저장 중 CBPE 필름 표면의 조도와 O와 N 원소를 포함한 작용기의 양을 증가시켰고, 인쇄적성, 열분해성, 그리고 미생물 분해성을 향상시켰다. 본 연구에서 CP 처리 후 CBPE 필름 표면에서 보여지는 노화 현상을 XPS 결과를 통해 확인할 수 있었다. 본 연구는 CP 처리가 CBPE 필름을 비롯하여 다른 생분해성 식품 포장재의 물리적 특성과 생분해성을 향상시킬 수 있는 기술로서 적용될 수 있다는 가능성을 보여주었다. The effects of cold plasma (CP) treatments on the physicochemical and biodegradable properties of a corn biomass-containing polyester (CBPE) film were studied. The CBPE film was treated with CP generated by N2, O2, He, Ar, or dry air at 400-900 W and 667 Pa for 10-40 min. The glass transition temperature of the CBPE film (?30.2- ?28.6℃) was not affected by the CP treatment, while the elastic modulus and water vapor permeability decreased (p<0.05). The ink printability was improved by the treatment and the improved printability was maintained during storage for 56 days at room temperature. Roughness of the film increased after treatments and the level of roughness appeared to increase during storage. Heat and microbial biodegradability of the CBPE film was improved by the air-CP treatment (p<0.05). These results have demonstrated the potential of applying CP treatments to improve the flexibility, printability, and biodegradability of CBPE films.