Hepaprotective Effect of Standardized Ecklonia stolonifera Formulation on CCl4-Induced Liver Injury in Sprague-Dawley Rats

변재혁,김준,정세영 한국응용약물학회 2018 Biomolecules & Therapeutics(구 응용약물학회지) Vol.26 No.2

The liver is an essential organ for the detoxification of exogenous xenobiotics, drugs and toxic substances. The incidence rate of non-alcoholic liver injury increases due to dietary habit change and drug use increase. Our previous study demonstrated that Ecklonia stolonifera (ES) formulation has hepatoprotective effect against alcohol-induced liver injury in rat and tacrine-induced hepatotoxicity in HepG2 cells. This present study was designated to elucidate hepatoprotective effects of ES formulation against carbon tetrachloride (CCl4)-induced liver injury in Sprague Dawley rat. Sixty rats were randomly divided into six groups. The rats were treated orally with ES formulation and silymarin (served as positive control, only 100 mg/kg/day) at a dose of 50, 100, or 200 mg/kg/day for 21 days. Seven days after treatment, liver injury was induced by intraperitoneal injection of CCl4 (1.5 ml/kg, twice a week for 14 days). The administration of CCl4 exhibited significant elevation of hepatic enzymes (like AST and ALT), and decrease of antioxidant related enzymes (superoxide dismutase, glutathione peroxidase and catalase) and glutathione. Then, it leaded to DNA damages (8-oxo-2’-deoxyguanosine) and lipid peroxidation (malondialdehyde). Administration of ES formulation inhibited imbalance of above factors compared to CCl4 induced rat in a dose dependent manner. Real time PCR analysis indicates that CYP2E1 was upregulated in CCl4 induced rat. However, increased gene expression was compromised by ES formulation treatment. These findings suggests that ES formulation could protect hepatotoxicity caused by CCl4 via two pathways: elevation of antioxidant enzymes and normalization of CYP2E1 enzyme.

TM3 세포에서 비수리 추출물이 테스토스테론 합성 및 분해에 미치는 영향

변재혁,유상우,이강표,정세영 대한약학회 2019 약학회지 Vol.63 No.3

This study focused the effects of Lespedeza cuneata extract (LCE) on testosterone synthesis and degradationin TM3 cells oxidatively stressed by hydrogen peroxide (H2O2). Testosterone level was decreased when the cells weretreated by H2O2, but it was restored to control level by LCE treatment in a dose dependent manner. We examined theexpression of the genes involved in the synthesis or degradation of testosterone to investigate the effect of LEC on thetestosterone metabolic pathway. The gene expression levels of CYP11A1, 17, 20-desmolase, 3β-HSD2 and 17β-HSD3which are involved in testosterone synthesis were decreased by H2O2 and were recovered by LCE treatment. Furthermore,aromatase and 5α-reductase2 which are involved in testosterone degradation were increased by H2O2 and were decreasedto the control level through LCE treatment. In conclusion, LCE restored testosterone level to control level throughincreasing the expression of testosterone synthetase and decreasing the expression of testosterone converting enzyme inoxidatively stressed TM3 cells. We demonstrated that LCE has a protective effect on testosterone reduction followed byandropause state

CO₂ 무 배출 침탄 열처리된 SCM415H 소재의 기계적 성질

변재혁,노승훈,이종형,이창헌,양성현,Byun, Jae-Hyuk,Ro, Seung-Hoon,Lee, Jong-Hyung,Lee, Chang-Hun,Yang, Seong-Hyeon 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.9

Vacuum carburizing is supposed to be the superior process to the gas carburizing. However, the vacuum carburizing has the stage in which hydrocarbon gas is supplied into the furnace to be pyrolysis, and consequently the stable heat treatment is hard to achieve due to the soot from the hydrocarbon pyrolysis. Recently, many studies have been made which utilize acetylene gas to overcome this defects. In this paper, the carburizing and the diffusion periods have been selected based on the Harris experimental formula, and the mechanical properties of the vacuum carburized specimen have been compared with those of the gas carburized SCM415H specimen to identify the feasibility of the $CO_2$ free vacuum carburizing process. The result showed that the vacuum carburized materials used have no oxidization of the grain boundaries, and show the 29.8% higher effective hardness depth and the acceptable tensile strength. 진공침탄법은 이산화탄소의 발생이 없는 친환경적인 열처리 방식으로 알려져 있다. 그러나 진공침탄법은 탄화수소 가스(메탄, 프로판)를 노내에 직접 공급하여 열분해하는 과정을 거침으로써 노내에 그을음이 발생하여 안정적인 조업이 불가능한 단점이 있다. 최근에는 이러한 단점을 극복하기위한 불포화 탄화수소인 아세틸렌가스를 이용한 진공침탄법이 활발히 연구되고 있다. 본 논문에서는 아세틸렌가스를 이용한 진공침탄방식의 침탄 및 확산 시간을 변수로 하여 여러 가지 조건에서 열처리를 진행한 후 가스침탄 열처리된 소재와 기계적 성질을 비교 분석하여 이산화탄소 무 배출 진공침탄 열처리 방법의 활용가능성을 확인하였다. 연구결과 본 연구에서 시도된 진공침탄법은 가스침탄에서 나타나는 입계산화층이 발생하지 않았으며 경도 값은 진공침탄 시험편의 유효경화 깊이가 29.8% 크게 나타났으며 인장강도는 가스침탄보다 10%낮게 나왔으나 허용치를 충분히 만족하는 수준이었다.

소자 부정합에 덜 민감한 12비트 60MS/s 0.18um CMOS Flash-SAR ADC

변재혁(Jae-Hyeok Byun),김원강(Won-Kang Kim),박준상(Jun-Sang Park),이승훈(Seung-Hoon Lee) 대한전자공학회 2016 전자공학회논문지 Vol.53 No.7

본 논문에서는 무선 통신 시스템 및 휴대용 비디오 처리 시스템과 같은 다양한 시스템 반도체 응용을 위한 12비트 60MS/s 0.18um CMOS Flash-SAR ADC를 제안한다. 제안하는 Flash-SAR ADC는 고속으로 동작하는 flash ADC의 장점을 이용하여 우선 상위 4비트를 결정한 후, 적은 전력 소모를 갖는 SAR ADC의 장점을 이용하여 하위 9비트를 결정함으로써 해상도가 증가함에 따라 동작 속도가 제한이 되는 전형적인 SAR ADC의 문제를 줄였다. 제안하는 ADC는 전형적인 Flash-SAR ADC에서 고속 동작 시 제한이 되는 입력 단 트랙-앤-홀드 회로를 사용하지 않는 대신 SAR ADC의 C-R DAC를 단일 샘플링-네트워크로 사용하여 입력 샘플링 부정합 문제를 제거하였다. 한편, flash ADC에는 인터폴레이션 기법을 적용하여 사용되는 프리앰프의 수를 절반 수준으로 줄이는 동시에 SAR 동작 시 flash ADC에서 불필요하게 소모되는 전력을 최소화하기 위해 스위치 기반의 바이어스 전력 최소화 기법을 적용하였다. 또한 고속 동작을 위해 SAR 논리회로는 TSPC 기반의 D 플립플롭으로 구성하여 범용 D 플립플롭 대비 논리회로 게이트 지연시간을 55% 감소시킴과 동시에 사용되는 트랜지스터의 수를 절반 수준으로 줄였다. 시제품 ADC는 0.18um CMOS 공정으로 제작되었으며, 측정된 DNL 및 INL은 12비트 해상도에서 각각 최대 1.33LSB, 1.90LSB이며, 60MS/s 동작 속도에서 동적성능은 최대 58.27dB의 SNDR 및 69.29dB의 SFDR 성능을 보인다. 시제품 ADC의 칩 면적은 0.54mm2이며, 1.8V 전원전압에서 5.4mW의 전력을 소모한다. This work proposes a 12b 60MS/s 0.18um CMOS Flash-SAR ADC for various systems such as wireless communications and portable video processing systems. The proposed Flash-SAR ADC alleviates the weakness of a conventional SAR ADC that the operation speed proportionally increases with a resolution by deciding upper 4bits first with a high-speed flash ADC before deciding lower 9bits with a low-power SAR ADC. The proposed ADC removes a sampling-time mismatch by using the C-R DAC in the SAR ADC as the combined sampling network instead of a T/H circuit which restricts a high speed operation. An interpolation technique implemented in the flash ADC halves the required number of pre-amplifiers, while a switched-bias power reduction scheme minimizes the power consumption of the flash ADC during the SAR operation. The TSPC based D-flip flop in the SAR logic for high-speed operation reduces the propagation delay by 55% and the required number of transistors by half compared to the conventional static D-flip flop. The prototype ADC in a 0.18um CMOS demonstrates a measured DNL and INL within 1.33LSB and 1.90LSB, with a maximum SNDR and SFDR of 58.27dB and 69.29dB at 60MS/s, respectively. The ADC occupies an active die area of 0.54mm2 and consumes 5.4mW at a 1.8V supply.

고령쥐를 이용한 비수리 추출물의 남성갱년기 증상 개선 및 테스토스테론 대사에 미치는 영향

변재혁(Jae-Hyuk Byun),정세영(Se-Young Choung) 대한약학회 2019 약학회지 Vol.63 No.6

This study focused on the effects of Lespedeza cuneata extract (LCE) to andropause symptoms in aged male Sprague-Dawley (SD) rats. SD rats were randomly divided into control or LCE treatment groups (125 or 250 mg/kg/day) and LCE was orally administered for 4 weeks. The body fat weight was decreased, and muscle weight was increased by LCE treatment. Also, the amount of semen and the number of sperm were increased. Serum levels of lipids (TG and TC) were decreased and total and free testosterone levels were increased. On the contrary, sex-hormone-binding-goblin (SHBG) and prostate specific antigen (PSA) levels were significantly decreased by LCE treatment. We examined the gene expressions involved in the synthesis or degradation of testosterone. The gene expression levels of CYP11A1, 17, 20- desmolase, 3β-HSD2 and 17β-HSD3 which are involved in testosterone synthesis were increased by LCE treatment. Furthermore, aromatase and 5α-reductase which are involved in testosterone degradation were decreased by LCE treatment. In conclusion, LCE suppressed andropause symptoms in aged SD rats via improving testosterone metabolic pathway.

열처리 냉각방식 변화에 따른 SCr420HB 헬리컬 기어 시뮬레이션적용에 관한 연구

변재혁 ( J H Byun ),변상덕 ( S D Byun ),이창헌 ( C H Yi ) 한국열처리공학회 2015 熱處理工學會誌 Vol.28 No.1

In this study, a simulation was used to derive an optimal process of heat treatment with carburizing, and compared the derived result with SCr420HB helical gear in heat treatment with carburized quenching process about a change of the quenching method. The optimal carburizing process time is derived by the simulation with the theoretical time. The process has been performed by oil quenching and salt quenching method. Through the comparison of the results from the simulation(Hardness, effective case depth hardened by carburizing treatment and deformation) and the actual process, analyzed the error value of each quenching. And it verified the applicability of the simulation.(rECEIVED dECEMBER 26, 2014; rEVISED jANUARY 2, 2015; ccepted January 7, 2015)

CO₂ 무 배출 침탄 열처리된 SCM415H 소재의 기계적 성질

변재혁(Jae Hyuk Byun),노승훈(Seung Hoon Ro),이종형(Jong Hyung Lee),이창헌(Chang Hun Lee),양성현(Seong Hyeon Yang) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.9

진공침탄법은 이산화탄소의 발생이 없는 친환경적인 열처리 방식으로 알려져 있다. 그러나 진공침탄법은 탄화수소 가스(메탄, 프로판)를 노내에 직접 공급하여 열분해하는 과정을 거침으로써 노내에 그을음이 발생하여 안정적인 조업이 불가능한 단점이 있다. 최근에는 이러한 단점을 극복하기위한 불포화 탄화수소인 아세틸렌가스를 이용한 진공침탄법이 활발히 연구되고 있다. 본 논문에서는 아세틸렌가스를 이용한 진공침탄방식의 침탄 및 확산 시간을 변수로 하여 여러 가지 조건에서 열처리를 진행한 후 가스침탄 열처리된 소재와 기계적 성질을 비교 분석하여 이산화탄소 무 배출 진공침탄 열처리 방법의 활용가능성을 확인하였다. 연구결과 본 연구에서 시도된 진공침탄법은 가스침탄에서 나타나는 입계산화층이 발생하지 않았으며 경도 값은 진공침탄 시험편의 유효경화 깊이가 29.8% 크게 나타났으며 인장강도는 가스침탄보다 10%낮게 나왔으나 허용치를 충분히 만족하는 수준이었다. Vacuum carburizing is supposed to be the superior process to the gas carburizing. However, the vacuum carburizing has the stage in which hydrocarbon gas is supplied into the furnace to be pyrolysis, and consequently the stable heat treatment is hard to achieve due to the soot from the hydrocarbon pyrolysis. Recently, many studies have been made which utilize acetylene gas to overcome this defects. In this paper, the carburizing and the diffusion periods have been selected based on the Harris experimental formula, and the mechanical properties of the vacuum carburized specimen have been compared with those of the gas carburized SCM415H specimen to identify the feasibility of the CO₂ free vacuum carburizing process. The result showed that the vacuum carburized materials used have no oxidization of the grain boundaries, and show the 29.8% higher effective hardness depth and the acceptable tensile strength.

SMEDDS를 이용한 naproxen의 용출률 개선 및 in vivo 효능 평가

변재혁(Jae-Hyuk Byun),조성완(Seong-Wan Cho) 한국산업기술융합학회(구. 산업기술교육훈련학회) 2024 산업기술연구논문지 (JITR) Vol.29 No.1

Naproxen은 비스테로이드성 진통소염제로, 통증, 염증, 해열제로서 사용되고 있다. 반감기가 길어서 효능이 오래 지속되어 환자들의 만족도가 높지만 용해도가 매우 낮다(in water 15.9mg/L). 용해도와 용출률을 높이기 위해 self-microemulsifying delivery system (SMEDDS)을 이용하여 가용화 시켰다. 주로 사용된 oil은 Labrasol ® 이고, 계면활성제로는 Labrafil ® M1944, Cremophor ® RH-40을 사용하였다. 선택한 oil과 계면활성제의 비율을 상평형도로 용해도가 좋은 영역을 도출하였다. 그 다음 적용 가능한 범위 내에서 효능을 확인하였다. 본 실험에서 만든 SMEDDS 로 naproxen을 가용화한 제제는, naproxen에 염을 붙인 정제 제품보다 용출률이 높았고, naproxen emulsion이 봉입된 연질캅셀 제품보다 위염 동물모델에서 위염 개선 능력 또한 뛰어난 것을 확인하였다. 본 연구 에서 naproxen의 SMEDDS의 적절한 oil과 비율을 제시하고, 효능, 용출률 및 안정성을 확인함으로써, 앞으로 naproxen 연구 및 제조의 방향성에 도움을 줄 것이다. Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) administered to reduce pain, inflammation, and fever. The extended half-life of naproxen enables prolonged efficacy, leading to symptom relief and high patient satisfaction. However, naproxen has notably low solubility in water (15.9 mg/L). The present study aimed to enhance the solubility and dissolution rate of naproxen by using a self-microemulsifying delivery system (SMEDDS). Labrasol® was used as the primary oil and Labrafil® M1944 and Cremophor® RH-40 as the surfactants in the SMEDDS. The ratio of the selected oil to the surfactant was determined to identify the equilibrium range with good solubility. Subsequently, the efficacy was confirmed to be within the applicable range. The results indicated that the SMEDDS formulation showed higher dissolution rates than the salt-formulated purified naproxen product. Furthermore, the efficacy was compared with that of commercially available naproxen emulsion-filled soft gel capsules in an animal model of gastric ulcers, showing the excellent gastro-protective abilities of the naproxen SMEDDS. This study provides an appropriate oil and ratio for a naproxen SMEDDS, confirming it sefficacy, dissolution rate, and stability. These results will guide future directions in naproxen research and manufacturing.

Protective Effects of Ecklonia stolonifera Extract on Ethanol-Induced Fatty Liver in Rats

방채영,변재혁,최혜경,최재수,정세영 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.6

Chronic alcohol consumption causes alcoholic liver disease, which is associated with the initiation of dysregulated lipid metabolism. Recent evidences suggest that dysregulated cholesterol metabolism plays an important role in the pathogenesis of alcoholic fatty liver disease. Ecklonia stolonifera (ES), a perennial brown marine alga that belongs to the family Laminariaceae, is rich in phlorotannins. Many studies have indicated that ES has extensive pharmacological effects, such as antioxidative, hepatoprotective, and antiinflammatory effects. However, only a few studies have investigated the protective effect of ES in alcoholic fatty liver. Male Sprague-Dawley rats were randomly divided into normal diet (ND) (fed a normal diet for 10 weeks) and ethanol diet (ED) groups. Rats in the ED group were fed a Lieber-DeCarli liquid diet (containing 5% ethanol) for 10 weeks and administered ES extract (50, 100, or 200 mg/kg/day), silymarin (100 mg/kg/day), or no treatment for 4 weeks. Each treatment group comprised of eight rats. The supplementation with ES resulted in decreased serum levels of triglycerides (TGs), total cholesterol, alanine aminotransferase, and aspartate aminotransferase. In addition, there were decreases in hepatic lipid and malondialdehyde levels. Changes in liver histology, as analyzed by Oil Red O staining, showed that the ES treatment suppressed adipogenesis. In addition, the ES treatment increased the expression of fatty acid oxidation-related genes (e.g., PPAR-α and CPT-1) but decreased the expression of SREBP 1, which is a TG synthesis-related gene. These results suggest that ES extract may be useful in preventing fatty acid oxidation and reducing lipogenesis in ethanol-induced fatty liver.

FPCB 열압착 프레스 개발에 관한 연구

안재우(Jae-Woo An),이창헌(Chang-Heon Lee),변재혁(Jae-Hyuk Byun),이종형(Jong-Hyung Lee) 한국산업융합학회 2008 한국산업융합학회 논문집 Vol.11 No.4

The bigger size of the wafer to the meet the need of higher productivity and the smaller digital products for convene are examples of the main trends of the market among others. The higher integrity of chips is also an important task in semiconductor industry. In this thesis the COF(chop on film) technology has reviewed to investigate the best combinations of required functions and to develop a new system to save the installation area and to adapt to the variation of layout with flexibility. The new system shows the better and provides the improved safety with smaller size.