장자와 Nietzsche 의 비교연구

조경현 중국철학회 1985 中國哲學 Vol.1 No.1

키토산의 E. coli O157 H7 의 증식 억제 효과

조경현,진구복,박노동 한국키틴키토산학회 2002 한국키틴키토산학회지 Vol.7 No.1

N/A N/A

A reconstituted HDL containing V156K or R173C apoA-I exhibited anti-inflammatory activity in apo-E deficient mice and showed resistance to myeloperoxidase-mediated oxidation

조경현,김재룡 생화학분자생물학회 2009 Experimental and molecular medicine Vol.41 No.6

It has been hypothesized that blood infusion of reconstituted HDL (rHDL) is a possible therapeutic strategy for the treatment of coronary artery disese. To compare short-term anti-inflammatory activity of wildtype (WT) apoA-I and point mutants, each rHDL containing WT, V156K, or R173C was infused into apo-E deficient atherosclerotic mice. Each rHDL was injected via the tail vein at a dosage of 120 mg/kg of body weight in 0.4 ml of tris-buffered saline (TBS), and blood was then collected at 24 and 48 h post-injection. Although regression activity was observed in each of the rHDL infused groups, a 30% reduction in the lipid-stained area of the aortic sinus was observed in the V156K and R173C-rHDL groups when compared to that of the WT-rHDL group, and this reduction was well correlated with an approximately 60% reduction in the accumulation of macrophages in the lesion area. Additionally, the groups that received the V156K and R173C-rHDL treatments showed smaller increases in the GOT, GPT, interleukin-6, myeloperoxidase (MPO) and lipid hydroperoxide (LPO) serum levels than those that received the WT-rHDL treatment. In addition, the strongest serum paraoxonase and ferric reducing ability was observed in the V156K and R173C-rHDL groups. In vitro nitration and chlorination of apoA-I by MPO treatment revealed that V156K-rHDL and R173C-rHDL were less susceptible to chlorination. Furthermore, rHDL treatment inhibited cellular uptake of oxidized LDL by macrophage cells and the production of proatherogenic species in culture media. In conclusion, blood infusions of the rHDLs exerted in vivo regression activity with anti-inflammatory and antioxidant activity in apo-E deficient mice and THP-1 cells, especially in those that were treated with V156K and R173C apoA-I.

가습기 살균제 성분(PHMG, PGH, CMIT/MIT)의 사람 피부세포 독성 및 제브라피쉬 뇌신경 독성 비교 연구

조경현,김재룡,Cho, Kyung-Hyun,Kim, Jae-Ryong 한국환경생물학회 2020 환경생물 : 환경생물학회지 Vol.38 No.2

가습기 살균제 성분(PHMG, PGH, CMIT/MIT)의 노출에 의한 다양한 장기에 대한 독성들에 대해서 피해사례는 계속 증가하고 있으나, 세포모델과 동물모델에서의 연구와 보고는 아직 부족한 실정이다. 심혈관 독성, 간 독성, 배아 독성에 대해서는 최근 알려져 있으나 뇌신경 독성과 피부 독성에 대해서는 상대적으로 적게 알려져 있다. 본 연구에서는 이들 세 가지 성분들의 피부 독성과 뇌신경 독성을 사람 피부섬유세포와 제브라피쉬 동물모델을 대상으로 각각 평가하였다. 사람피부섬유세포에 세 가지의 성분들을 0, 2, 4, 6, 8, 16 mg L^-1 (최종농도)로 처리하였을 때, 세포 생존율은 PHMG가 33%로 가장 낮았고, PGH가 49%, CMIT/MIT가 40%의 생존율을 보였다. 세포배양액 내의 산화물을 정량해본 결과, PHMG 처리된 세포가 28 nmol MDA로 가장 높았고, PGH가 13 nmol MDA, CMIT가 21 nmol MDA를 보였다. 제브라피쉬 사육수조에 PHMG, PGH, CMIT를 40 mg L^-1의 최종농도가 되도록 희석한 후, 제브라피쉬를 30분간 노출시킨 후 중뇌의 광시개영역(optic tectum)을 횡면 미세절단하여 산화물의 생성정도를 비교해본 결과, CMIT/MIT를 처리한 그룹에서 대조군 대비 17배 많은 산화물의 생성이 있었고, PGH를 처리한 그룹에서는 15배, PHMG를 처리한 그룹에서는 11배 많은 산화물이 관찰되어 심각한 뇌신경계 독성을 보여주었다. 결론적으로 세 가지 종류의 가습기 살균제 성분들에서 모두 심각한 피부세포 독성과 뇌신경계 독성이 나타났는데, 피부 독성은 특히 PHMG가, 뇌신경계 독성은 특히 CMIT/MIT가 가장 심각하였다. 이들 결과들은 가습기 살균제에 노출된 어린이들이 뇌신경계 독성을 통하여 언어장애, 운동장애, 발달장애 등을 겪게 될 수도 있음을 실험적으로 제시한다. Toxicities to many organs caused by humidifier disinfectants have been reported. Recently, humidifier disinfectants have been reported to cause cardiovascular, embryonic, and hepatic toxicities. This study was designed to investigate the toxic mechanism of humidifier disinfectants and compare toxicity in a cellular model and a zebrafish animal model. Because brain toxicity and skin toxicity have been less studied than other organs, we evaluated toxicity in a human dermal cell line and zebrafish under various concentrations of humidifier disinfectants that included polyhexamethyleneguanidine phosphate (PHMG), oligo-[2-(2-ethoxy)-ethoxyethyl-guanidinium-chloride] (PGH) and methylchloroisothiazolinone/methylisothiazolinone (CMIT/MIT). A human dermal fibroblast cell line was treated with disinfectants (0, 2, 4, 6, 8, and 16 mg L^-1) to compare their cytotoxicity. The fewest PHMG-treated cells survived (up to 33%), while 49% and 40% of the PGH- and CMIT/MIT-treated cells, respectively, survived. The quantification of oxidized species in the media revealed that the PHMG-treated cells had the highest MDA content of around 28 nM, while the PGH- and CMIT/MIT-treated cells had 13 and 21 nM MDA, respectively. As for brain toxicity, treatment of the zebrafish tank water with CMIT/MIT (final 40 mg L^-1) for 30 min resulted in a 17-fold higher production of reactive oxygen species (ROS) than in the control. Treatment with PGH or PHMG (final 40 mg L^-1) resulted in 15- and 11-fold higher production, respectively. The humidifier disinfectants (PHMG, PGH, and CMIT/MIT) showed severe dermal cell toxicity and brain toxicity. These toxicities may be relevant factors in understanding why some children have language disorders, motor delays, and developmental delays from exposure to humidifier disinfectants.

BMB reports 리뷰 소개 : 고밀도 단백질의 생물의학적 의미: 구성, 구조, 기능 임상적 응용의 측면

조경현 한국생화학회 2009 생화학분자생물학회 소식 Vol.29 No.3

가중치가 부과된 Bit-flipping 기법을 이용한 LDPC 코딩

조경현,나극환 대한전자공학회 2006 電子工學會論文誌 IE (Industry electronics) Vol.43 No.4

In this paper, we proposed about data error check and correction on channel transmission in the communication system. LDPC codes are used for minimizing channel errors by modeling AWGN Channel as a VDSL system. Because LDPC Codes use low density parity bit, mathematical complexity is low and relating processing time becomes shorten. Also, the performance of LDPC code is better than that of turbo code in long code word on iterative decoding algorithm. This algorithm is better than conventional algorithms to correct errors, the proposed algorithm assigns weights for errors concerning parity bits. The proposed weighted Bit-flipping algorithm is better than the conventional Bit-flipping algorithm and we are recognized improve gain rate of 1 dB. 본 논문에서는 통신 시스템에서 채널 전송에 의한 데이터의 오류 체크와 정정문제에 대해서 제안하였다. 제안된 LDPC 코드는 VDSL 시스템에서의 AWGN 채널 모델링에 의해 최소화된 채널 에러를 위해 사용된다. LDPC 코드는 낮은 밀도 패리티 비트를 사용하기 때문에, 수학적인 복잡도가 낮고 처리 시간이 짧다. 또한 LDPC 코드의 성능은 반복 복호 알고리즘에서 긴 코드 워드에 대해 터보 코드보다 더 나은 성능을 가지고 있다 제안된 시스템의 송신기에서 발생 행렬에 의해서 부호어가 발생되고, 수신기에서 사용된 에러 정정 알고리즘은 가중치를 갖는 Bit-flipping 방식이다. 이 방식은 기존의 Bit-flipping 방식과 달리 더 정확한 에러를 검출하고, 정정하기 위해 발생된 패리티 비트에 대해서 가중치를 주어 에러 정정을 하는 방식이다. 제안된 가중치를 갖는 Bit-flipping 알고리즘은 기존의 Bit-flipping 알고리즘에 비해서 1 dB 이상의 이득 개선을 확인할 수 있었다.

Structure and Functions of HDL and LDL are Severely and Transiently Modified in the Oliguric Phase of Hemorrhagic Fever with Renal Syndrome

조경현,박정의,김영옥,김재룡 한국지질동맥경화학회(구 한국지질학회) 2007 한국지질동맥경화학회 추계학술발표논문집 Vol.2007 No.-

발효유시장의 마케팅 전략과 사례 - 한국야쿠르트의 「발효유」

조경현 한국마케팅연구원 1997 마케팅 Vol.31 No.8

소요와 장자철학

조경현 중국철학회 1991 中國哲學 Vol.2 No.1

Monoacylglycerol (MAG)-Oleic Acid Has Stronger Antioxidant, Anti-Atherosclerotic, and Protein Glycation Inhibitory Activities than MAG-Palmitic Acid

조경현,홍주헌,이기택 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.1

A functional oil containing diacylglycerol (DAG) and monoacylglycerol (MAG) has been shown to have a strong anti-atherosclerotic effect in a mouse model. Among the lipid components, MAG is responsible for the beneficial effect with an enhanced antioxidant effect in the mouse model. In this report, several MAG-containing fatty acids (MAG-oleic acid [MAG-O], MAG-palmitic acid [MAG-P], and MAG-stearic acid [MAG-S]) were synthesized, and the antioxidant and anti-atherogenic activities were evaluated in vitro and in a cellular model. MAG-O had the strongest radical scavenging and antioxidant activities against copper-mediated low-density lipoprotein (LDL) oxidation and the strongest inhibitory activity against LDL-associated phospholipase A2 and exhibited potent activation of paraoxonase activity, which contributes to the maintenance of antioxidant activity. All MAG species in this study exhibited inhibitory activity against glycation of apolipoproteins, in contrast to DAG. Oxidized LDL uptake into THP-1 cells was strongly inhibited by MAG-O treatment at a final concentration of 20μM. MAG-O-treated cell culture medium showed the lowest production of malondialdehyde and lipid hydroperoxide compared to MAG-S and MAG-P. In conclusion, MAG-O had potent antioxidant, antidiabetic, and anti-atherogenic effects in vitro and in a cellular model.