Improvement of interlaminar properties of carbon fiber‑reinforced epoxy composites using aluminum trihydroxide

Dong‑Jun Kwon,Sung‑Min Park,Il‑Jun Kwon,Joung‑Man Park,Euigyung Jeong 한국탄소학회 2019 Carbon Letters Vol.29 No.2

This study provides an economical and effective method to improve the interlaminar properties of carbon fiber-reinforced polymers (CFRPs) using aluminum trihydroxide (ATH) microparticles. ATH microparticles are cheap and are expected to show good affinity to epoxies in the matrix and sizing agents of the carbon fibers owing to the presence of three hydroxyl groups. In addition, ATH particles are reported to improve the mechanical properties of polymers when used as the reinforcement. In this study, ATH microparticles of various sizes, 1.5, 10, and 20 μm, were used to improve the interlaminar properties of the CFRPs. ATH particles with a size of 1.5 μm improved the tensile properties of the ATH/epoxy resin and did not significantly alter the curing behavior. The interfacial adhesion between the carbon fiber and the epoxy resin was also improved, and the impregnation of the resin mixture remained similar to that of the neat resin, resulting in no significant void and defect formation. Considering the above results, the resulting 1.5 μm ATH-reinforced CFRP showed improved interlaminar properties compared to CFRP without ATH. However, 10 and 20 μm ATH-reinforced CFRPs showed deteriorated interlaminar properties due to the diminished tensile properties of the resin itself and resin impregnation, which resulted in more voids and defects, despite the interfacial adhesion between the fiber and the matrix resin.

NGS_SNPAnalyzer: a desktop software supporting genome projects by identifying and visualizing sequence variations from next-generation sequencing data

Dong‑Jun Lee,Taesoo Kwon,Chang‑Kug Kim,Young‑Joo Seol,Dong‑Suk Park,Tae‑Ho Lee,Byung‑Ohg Ahn 한국유전학회 2020 Genes & Genomics Vol.42 No.11

Background Sequence variations such as single nucleotide polymorphisms are markers for genetic diseases and breeding. Therefore, identifying sequence variations is one of the main objectives of several genome projects. Although most genomeproject consortiums provide standard operation procedures for sequence variation detection methods, there may be differencesin the results because of human selection or error. Objective To standardize the procedure for sequence variation detection and help researchers who are not formally trainedin bioinformatics, we developed the NGS_SNPAnalyzer, a desktop software and fully automated graphical pipeline. Methods The NGS_SNPAnalyzer is implemented using JavaFX (version 1.8); therefore, it is not limited to any operatingsystem (OS). The tools employed in the NGS_SNPAnalyzer were compiled on Microsoft Windows (version 7, 10) andUbuntu Linux (version 16.04, 17.0.4). Results The NGS_SNPAnalyzer not only includes the functionalities for variant calling and annotation but also providesquality control, mapping, and filtering details to support all procedures from next-generation sequencing (NGS) data to variantvisualization. It can be executed using pre-set pipelines and options and customized via user-specified options. Additionally,the NGS_SNPAnalyzer provides a user-friendly graphical interface and can be installed on any OS that supports JAVA. Conclusions Although there are several pipelines and visualization tools available for NGS data analysis, we developedthe NGS_SNPAnalyzer to provide the user with an easy-to-use interface. The benchmark test results indicate that theNGS_SNPAnayzer achieves better performance than other open source tools.

한약과 와파린 병용의 상호작용과 안전성에 대한 연구

권동현 ( Dong Hyun Kwon ),김호준 ( Ho Jun Kim ),이명종 ( Myeong Jong Lee ),송미영 ( Mi Young Song ) 한방재활의학과학회 2010 한방재활의학과학회지 Vol.20 No.2

Objectives: The purpose of this study is to investigate interaction and safety in administering herb-medicine with warfarin. Methods :For this study, we selected 19 patients who have been taking warfarin, from the ones that have been transferred from western hospital to oriental hospital. During their stay in the oriental hospital, we gave herb-medicine in addition to warfarin. Then we gathered informations and data on sex, age, main indications, and International Normalized Ratio(INR) values of selected patients through Electronic Medical Records(EMR) of Dong-Guk university hospital. Accordingly, we compiled all of the above data for a period of 10 days prior and 10 days post admission(western hospital period and oriental hospital period, respectively)Results and Conclusions :The statistical analysis of the data have revealed that there was no significant change of INR values after giving herb-medicine with warfarin(p=0.586). The result shows that administration of herb-medicine with warfarin is safe and has little drug interaction. However, this study was carried out on small sample size and the interaction with other drugs and various kinds of herb-medicine was not considered. Although we attained a restrictive result from this study, we are able to suggest the safety about co-administration of herb-medicine and warfarin.

프리미돈의 한국인에서의 생체이용율시험

권광일,윤민혁,윤희열,박희찬,권준택,심희옥,김동출 충남대학교 약학대학 의약품개발연구소 2004 藥學論文集 Vol.19 No.-

A reversed phase HPLC method was developed and validated for the determination of primidone in human plasma. Propylthiouracil was used as an internal standard. Calibration curves were linear in the concentration range of 10-120 ng/㎖. The coefficient of variation of the intra- and inter-day precision were below 15%. The coefficient of variation of the accuracy were below 15% in the concentration range investigated. A bioavailability study was performed using the validated HPLC method. Twenty four healthy human male volunteers were orally administered 20 mg of primidone. The pharmacokinetic parameters were calculated using WinNonlin. The mean values of AUC_(LAST) was 85.0±17.7 ㎍ hr/㎖, C_(max) was 4.22±1.04 ㎍/㎖, T_(max) was 1.85±1.13 hr, t_(1/2) was 17.7±2.4 hr. The pharmacokinetic parameters and the HPLC method can be used for the desigm of bioequivalence study of primidone.

[18F]FDG PET을 이용한 강박증 환자에서 뇌 포도당 대사의 이상에 관한 연구

권준수,이동우,이재성,최정임,이동수,정준기,조맹제,이명철,류인균 대한신경정신의학회 2000 신경정신의학 Vol.39 No.2

연구목적: 강박증에 대한 기능적 뇌영상 연구들에서 강박증 환자들의 안와전두엽과 미상핵의 대사율 증가 소견이 비교적 일과되게 발표되어 왔으며, 전두-피질하 회로의 이상이라는 이론이 수립되기도 하였다. 그러나 기존의 연구들은 강박증의 유병기간에 따른 구분없이 시행된 연구였고, 영상분석 방법에 있어서도 관심영역 방법을 이용했다는 한계를 지니고 있다. 본 연구의 목적은 첫째, 강박증의 유병기간에 따라 환자군을 구분하여 PET 영상소견을 분석함으로써 유병 기간에 따른 차이가 있는지를 조사하였으며, 둘째, 강바증 환자의 포도당 양전자방출 단층촬영(18-Fluor-deoxyglucose Positron Emission Tomography : FDG-PET) 영상분석에 통계적 매개변수 지도법(Statistical Parametric Mapping : SPM)을 이용함으로써 강박증의 병인기전 및 강박증상과 뇌기능 간의 관계를 명확히 규명하고자 하였다. 방법: 구조적 면담도구(Structured clinical interview for DSM-IV : SCID-IV)를 적용하여 진단된 12명의 강박증 환자들과 10명의 정상 대조군에 대해 FDG-PET을 촬영하여 SPM으로 분석하였다. PET 촬영 전 적어도 4주 동안에는 약물복용을 하지 않은 상태였다. 결과: 1) 환자군과 대조군의 비교 : 강박증 환자군은 대조군에 비해 양측 두정 영역의 대사율이 유의하게 감소되어 있었으며(P<0.01). 대사증가를 보인 영역은 없었다. 강박증의 유병기간이 10년 이상인 만성강박증 환자 4명은 양측 안와전두엽에서 유의한 대사증가 소견을 보였으며(P<0.01), 양측 두정영역에서 유의한 대사감소 소견을 보였다 (P<0.01), 유병기간이 10년 이하인 환자에서는 전체 환자군의 분석에서와 마찬가지로 대조군에 비해 유의한 대사증가 소견을 보인 영역은 없었으며, 양측 두정엽 부위에서 유 의한 대사 감소 소견을 보였다.(P<0.01). 2) 강박증상의 심각도와의 상관관계 분석 : 우측 두정엽의 대사율은 강박장애 척도 점수와 유의한 음의 상관관계를 보였으며(p<0.01), 양측 시상 영역의 대사율은 예일-브라운 강박장애 척도의 강박장애척도 점수와 유의한 양의 상관관계(p<0.01)를 보였다. 결론: 본 연구는 결과는 기존의 연구들에서 보고된 안와전두엽의 대사 증가 소견이 강박증의 만성화로 인해 나타나는 2차적 장애이며, 두정엽의 대사 저하가 보다 1차적인 장애일 가능성을 시사한다. Baxter가 수립한 전두-피질하 회로 이론은 두정엽의 이상을 포함하는 전두-두정엽 복합체 이론으로 확장되어야 할 것이다. Objectives: Functional imaging studies on obsessive-compulsive disorder(OCD) subjects have repeatedly reported increased metabolism in orbitofrontal lobes and caudate nucleus, resulting in the "frontal-subcortical" circuit abnormality theory. Limitations of the previous studies to date include little consideration for the duration of illness, and the use of regions of interest methods, as an image analysis method. Our study objectives are 1) to include the duration of illness as an important study variable, and 2) to use Statistical Parametric Mapping(SPM) method in order to tap relations between the brain function and the psychopathology and symptoms of OCD. Methods: The [18] fluorodeoxyglucose positron emission tomography(FDG-PET) scans of OCD subjects and normal comparison subjects, as diagnosed by the Structured Clinical Interview for DSM-IV(SCID-IV), were analyzed using SPM. Results: 1) Comparison of OCD and control groups : OCD subjects had significantly decreased metabolism in both parietal lobes and didn't have any areas of increased metabolism in comparison to comparison subjects(p.<0.01). four OCD subjects with the illness duration of 10 years or longer, had significantly increased metabolism in both orbitofrontal lobes<p<0.01). OCD subjects whose illness duration is shorter than 10 years didn't have any areas of increased metabolism and had significantly decreased parietal lobe metabolism, as in the analyses of all subjects(p<0.01). 2) Correlation analysis between areas and symptom severity : Metabolism of both thalamic sreas showed significant positive correlation with Yale-Brown Obsessive-Compulsive Scale(Y-BOCS) scores(p<0.01). Metabolism of right parietal area showed significant negative corre lation with Y-BOCS scores(p<0.01). Conclusions: The current findings suggest that the increased metabolism in orbitofrontal lobe, previously rported, may be a secondary phenomenon due to the extended illness dur- ation and that decreased metabolism in the parietal lobes are primary abnormality in OCD subjects. Thus Baxter's fronto-subcortical circuit theory should be extended into "fronto-pari-etal" complex theory, which includes the parietal lobes.

한국인에서의 CYP2E1 유전자형

권준택,김형기,손동렬,염윤기 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

Cytochrome P4502E1 (CYP2E1) is inducible by ethyl alcohol and activates procarcinogenic N-nitrosodimethylamine (NDMA), benzene, urethane and other lower molecular weight compound. CYP2E1 is also involved in metabolism of certain drugs, for example, alcohol, acetaminophen, tamoxifen, theophylline, fluorinated anesthetics, and chlorozoxazone. CYP2E1 activity was shown to be polymorphically distributed in humans and has been suggested to play a role in hepatocellular carcinoma and alcoholic related disorders. Although genetic predisposition to alcoholism and alcoholic liver disease has been reported, genetic susceptibility to alcoholic pancreatitis is still a matter of debate. The aims of this study were to investigate the allelic frequency of CYP2E1 Rsa I polymorphism in Koreans. We investigated the frequency distribution of CYP2E1 Rsa I polymorphism in 212 unrelated healthy Koreans and 42 hepatocellular carcinoma patients. Detection of the CYP2E1 alleles was performed by polymerase chain reaction and restriction fragment length analysis. The genomic DNA was isolated from peripheral blood with conventional phenol: chloroform extraction method. The allelic frequencies of c1 and c2 in healthy volunteers were 0.85 and 0.15, respectively. The rare type (c2/c2) of CYP2E1 Rsa I polymorphism was 0.005 in healthy volunteers.

합성 염료 수용액에 대한 다공성 Ceramic의 흡착 특성

권이열,윤동준,지형하 漢陽大學校 環境科學硏究所 1989 環境科學論文集 Vol.10 No.-

소수성으로 처리한 다공성 ceramic의 흡착특성을 연구하고자 합성 염료수용액을 회분식으로 실험하였다. 다공성 ceramic의 양(1,2,3,4,5g) 및 particle size(30∼50, 50∼100, 100∼200mesh), temperature(25,30,40℃) 및 흡착시간(0.5,1,2,3hr)의 변화에 따라 탈색율(decoloring efficiency)을 관찰한 결과, 염기성 염료(methyl violet 2B)가 99.6%로 가장 좋았으며, 직접 염료(congo red)가 95.3%, 각 염료의 혼합용액(acid orange Ⅱ, nylon fast blue R, congo red, dark green 2B, methy, violet 2B, cationic red 7BN의 동일비율 혼합)이 70.5%, 산성 염료 (acid orange Ⅱ)가 62.8%인 순서로 나타났다. 흡착제의 양 및 흡착시간, 온도증가에 비례하였으며, particle size가 작을 수록 증가하였다. 이들 조건중 pH의 영향이 가장 크며, pH가 높을수록 흡착효율이 증가하였다. 다공성 ceramic의 염료 조색단(auxochrome)에 대한 친화성은 술폰산기(-SO₃H)에 비해 아미노기(-NH₂)가 우수한 것으로 나타났다. 전반적인 흡착경향은 염기성염료와 직접염료는 Freundlich 등온흡착식에 적합하게 일치되었으며, 산성염료는 Henry형에, 혼합용액은 Langmuir형과 유사한 상관도를 보였다. 재생이 가능한 장점으로 보아 흡착제로 유용하게 사용할 수 있을 것으로 전망된다. The adsorptive properties of porous ceramics(made of sam-wha ceramic co.) in aqueous dyes solution was performed by batch test. The measured decoloring efficiencies were 99.6% for methyl violet 2B, 95.3% for congo red, 70.5% for mixed dyes, 62.8% for acid orange II under various reaction conditions-amounts of porous ceramic, paricle size, temperature and pH. The decoloring efficiency was severely affected by pH, and increased at higher pH. The adsorption rate improved by enhancing adsorption time, amounts of porous ceramic and temperature, increased as the particle size down. Porous ceramics had an affinity for nitro-radical(-NH₂), but not sulphonic-radical(-SO₃H). It was suggested that the porous ceramics was a useful adsorbent because of regenerable merit.

흰쥐에서 탄수화물 종류가 운동시 당 및 지질대사에 미치는 영향

권태동,전중기,민경선,김형렬,장응찬 대구대학교 기초과학연구소 1998 基礎科學硏究 Vol.15 No.2

The purpose of this study was to investigate the effects of glucose, sucrose, and glucose polymer(GP) ingestion on the carbohydrate and lipid metabolism during treadmill running in rats. Rats were randomly assigned to normal, control and carbohydrate groups. Carbohydrate group was divided into glucose, sucrose and GP ingested rats. The experiment was carried out after overnight fasting. Rats were administrated either normal saline(control) or carbohydrates solutions of formulated glucose(6%), sucrose(6%) and GP(6%) via polyethlene tube to stomach before treadmill run. Exercise was loaded by a treadmill run at the speed of 1 km/hour for 30, 60 and 120 minutes. The results of experiment were as follows: Plasma glucose levels were decreased in proportion to the exercise time in control, but increased at treadmill run 30 minutes and then gradually decreased with the lapse of the exercise time in carbohydrates compared with normal rats. It decreased in control, glucose, sucrose and GP compared with normal rats in decreasing order at treadmill run 120 minutes(% change of plasma glucose level of control, glucose, sucrose and GP compared with normal rats were 67, 74, 87 and 91 in plasma glucose level at treadmill run 120 min., respectively). Plasma lactate levels were increased by the exercise loading compared with normal in control and carbohydrates ingested rats. It increased in control, sucrose and GP in increasing order compared with normal rats, at treadmill run 120 minutes(% change of plasma lactate level of control, glucose, sucrose and GP compared with normal rats were 167, 185, 149 and 114 in plasma lactate level at treadmill run 120 min., respectively). Plasma FFA levels had tendency to increase by the exercise loading compared with normal in control and carbohydrates ingested rats. It showed increase in the sucrose, glucose, GP and control rats in Increasing order compared with normal rats at treadmill run 120 minutes(% change of plasma FFA level of control, glucose, sucrose and GP compared with normal rats were 151, 153, 166 and 152 in plasma FFA level at treadmill run 120 min., respectively). Plasma acetoacetate levels were higher in control compared with carbohydrates ingested rats at treadmill run 30, 60 and 120 minutes. Plasma beta-hydroxybutyrate levels increased by exercise compared with normal rats in control and carbohydrates ingested rats at treadmill run 30, 60, 120 minutes. Plasma insulin levels were decreased in proportion to the exercise time in control compared with normal rats, but in carbohydrates ingested rats increased at treadmill run 30 minutes and then gradually deceased with the lapse of the exercise time compared with normal. In carbohydrates ingested rats, plasma insulin levies were higher than control. Hematocrit did not show any difference between control and carbohydrates rats at treadmill run 30, 60 and 120 minutes. From these experimental results, it is suggested that the exhaustion of skeletal muscle glycogen, the hypoglycemia, the overproduction of lactate and dehydration is delayed in carbohydrates ingested rats. GP of the carbohydrates is considered as the most effective for these effects. Therefore, intake of carbohydrates before exercise, especially GP seems to increase performance in the prolonged moderate exercise.

한국인에서의 CYP2C19 유전자형의 다형성

권준택,김형기,손동렬,염윤기 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

The S-mephenytoin 4'-hydroxylase (CYP2C19) metabolizes a number of clinically used drugs and shows a marked interethnic difference in the incidence of the poor metabolizer (PM). In the present study, we genotyped 215 healthy unrelated Koreans (64 females, aged 20-41 yr, residing in Chungcheong province) for functionally defective alleles, CYP2C19_(m1) and CYP2C19_(m2). Detection of the normal (CYP2C19_(wt)) and defective alleles was performed by polymerase chain reaction/restriction enzyme analysis. The genomic DNA was isolated from peripheral blood. The allelic frequencies of the wild-type (CYP2C19_(wt)) and CYP2C19_(m1) were 72.6% and 27.4%, and the wild-type (CYP2C19_(wt)) and CYP2C19_(m2) were 85.1% and 14.9%, respectively. For each CYP2C19_(m1) and CYP2C19_(m2), the observed numbers of three genotypes were similar to those calculated in accordance with the Hardy-Weinberg equation. The frequencies of homozygotes for CYP2C19_(m1), CYP2C19_(m2) and compound heterozygotes were 9.7%, 2.8% and 4.2%, respectively. The mutants of CYP2C19 were identified in 36 subjects (16.7%). These results suggest that frequency of mutants of CYP2C19 in Koreans resembled the Orientals rather than Caucasians.

평면에서 형상정보를 갖는 물체의 접촉 해석

전경진,손정현,강동권 동의공업대학 2001 論文集 Vol.27 No.1

This paper presents a method for calculating contact force of any shaped rigid bodies on plane. Every integration time step, the proposed method finds expected contact point on their outlines and then calculates penetration and contact force. This paper is using the continuous analysis method to calculate contact force. To get the accurate expected contact point on their outlines the new algorithm is developed. Through the comparison with DADS, we can prove the accuracy of the proposed algorithm.