Biomass 유래 퓨란계 단량체를 이용한 폴리에스터의 중합 및 특성 연구

정용석(Yong Seong Chung),이영철(Young Chul Lee),서강진(Kang Jin Seo),김명준(Myeong Jun Kim),정지혜(Ji Hea Jeong),노시태(Si Tae Noh) 한국고분자학회 2011 폴리머 Vol.35 No.6

바이오매스에서 유래된 2,5-dihydroxymethylfuran(DHMF)을 KMnO4 산화반응으로 furan-2,5- dicarboxylic acid(FDCA)를 합성하였다. 합성한 FDCA와 다이올류를 에스테르화 반응과 축중합 반응을 진행시 켜 폴리에스터를 중합하였다. 폴리에스터는 NMR을 통해 조성을 분석하였고 DSC와 TGA를 통해 열적특성을 분 석하였다. 합성된 폴리에스터의 고유점도는 0.78∼1.2 dL/g으로 상용화된 poly(ethylene terephthalate)(PET) 와 비슷하였다. 다이올의 길이가 증가할수록 Young`s modulus와 strength는 낮아지고 elongation-to-break는 높아지는 경향을 확인하였다. 합성한 poly(ethylene furandicarboxylate)(PEF)의 Young`s modulus는 3551 MPa, strength는 103 MPa로 상용화된 PET와 비슷하였다. Furan-2,5-dicarboxylic acid (FDCA) was synthesized by KMnO4 oxidation of 2,5-dihydroxymethylfuran( DHMF) derived from biomass. Polyesters were synthesized by esterification and polycondensation of FDCA with various diols(ethane-1,2-diol, propane-1,3-diol, butane-1,4-diol, hexane- 1,6-diol, decane-1,10-diol). The composition of polyesters was characterized by using 1H NMR. Thermal properties of the polyesters were characterized by DSC and TGA. Intrinsic viscosities(IV) of the polyesters were measured to be 0.78∼1.2 dL/g comparable with IV of commercial poly(ethylene terephthalate)(PET). As the chain lengths of diols increased, Young`s modulus and strength decreased and elongation-to-break generally increased. Young`s modulus and strength of the polyesters were measured to be 3551 MPa and 103 MPa, respectively, comparable with commercial PET.

A STUDY ON THE RISK PROTECTION OF THE MOLD TRANSFORMER

Chung,Young-Ki,Jung,Jong-Wook,Kim,Jae-Chul,Kwak,Hee-Ro,Lee,Su-Kyung 한국화재소방학회 1997 한국화재소방학회 학술대회 논문집 Vol.1997 No.-

This paper investigates and analyzes the installation and failure status of mold transformer being used in domestic subways and describes the extinguishing process by time through the combustion test of winding part of mold transformer. Condition of installed mold transformers and classes of fire were surveyed and the mold transformer was burned in a horizontal heating furnace. It was confirmed that the mold transformer is self extinguishing and nonflammability. According to this results, the suitable standard of fire protection for the mold transformer was demanded after review of domestic and abroad law. It is expected that the cost of fire protection equipment can be reduced by using the status and combustion test result of mold transformer.

Contribution of stress and coping strategies to problematic Internet use in patients with schizophrenia spectrum disorders

Lee, Ju-Yeon,Chung, Young-Chul,Song, Je-Heon,Lee, Yo-Han,Kim, Jae-Min,Shin, Il-Seon,Yoon, Jin-Sang,Kim, Sung-Wan Elsevier 2018 Comprehensive psychiatry Vol.87 No.-

<P><B>Abstract</B></P> <P><B>Introduction</B></P> <P>Internet use is already high and increasing rapidly among people with psychotic disorders, but there have been few studies on problematic Internet use (PIU) among patients with schizophrenia spectrum disorders. This study aimed to measure the prevalence of PIU and identify the factors associated with PIU among patients with schizophrenia spectrum disorders.</P> <P><B>Methods</B></P> <P>A cross-sectional survey was performed that included 368 outpatients with schizophrenia spectrum disorders: 317 with schizophrenia, 22 with schizoaffective disorder, 9 with schizophreniform disorder, and 20 with other schizophrenia spectrum and psychotic disorders. The severity of psychotic symptoms and levels of personal and social functioning were assessed by the Clinician-rated Dimensions of Psychosis Symptom Severity (CRDPSS) scale and the Personal and Social Performance (PSP) scale, respectively. PIU was evaluated using Young's Internet Addiction Test (IAT). Additionally, the Hospital Anxiety and Depression Scale (HADS), Perceived Stress Scale (PSS), Rosenberg Selfesteem Scale (RSES), and Brief Coping Orientation to Problems Experienced (COPE) Inventory were administered.</P> <P><B>Results</B></P> <P>PIU was identified in 81 (22.0%) of the 368 patients with schizophrenia spectrum disorders. Subjects with PIU were significantly younger and more likely to be male. Scores on the HADS, PSS, and dysfunctional coping dimension of the Brief COPE Inventory were significantly higher, and RSES scores were significantly lower, in the PIU group. Logistic regression analysis indicated that PIU in patients was significantly associated with scores on the PSS and dysfunctional coping dimension of the Brief COPE Inventory.</P> <P><B>Conclusions</B></P> <P>Patients with schizophrenia spectrum disorders and PIU were significantly more likely to have high levels of perceived stress and dysfunctional coping strategies. Patients with schizophrenia spectrum disorders who also engage in PIU may benefit from interventions that help them to develop appropriate skills for coping with stress.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Patients with schizophrenia spectrum disorders showed a high prevalence (22.0%) of problematic internet use (PIU). </LI> <LI> High levels of perceived stress rather than psychopathology itself contributes to the development of PIU in stabilized patients with schizophrenia. </LI> <LI> Our results indicate that managing stress and developing coping strategies are important for the prevention of PIU among this group of patients. </LI> </UL> </P>

Asian Subgroup Analysis of the REMISSIO Study: A Long-Term Efficacy and Safety Study of Paliperidone Palmitate 3-month Formulation in Patients with Stable Schizophrenia in a Naturalistic Clinical Setting

Young-Chul Chung,Yen Kuang Yang,Ahmad Hatim Sulaiman,Paul Bergmans,Wilson Tan 대한정신약물학회 2022 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.20 No.3

Objective: To evaluate the long-term efficacy and safety of three-monthly paliperidone palmitate (PP3M) in Asian patients with stable schizophrenia in a naturalistic setting. Methods: Asian patients recruited between May 2016 and March 2018 from the prospective, single-arm, non-randomized, open-label, multi-national REMISSIO study were analyzed. Patients received PP3M over 12 months following ≥ 4 months of treatment with one-monthly paliperidone palmitate. The primary efficacy endpoint was the proportion of patients who achieved symptomatic remission. Other endpoints were changes in Positive and Negative Syndrome Scale (PANSS) and Personal and Social Performance (PSP) total scores, hospitalization rates, and safety. Results: A total of 71 patients (23.3%) were Asian (South Korea: 33, Malaysia: 21, Taiwan: 17); 95.8% of patients completed the study. At LOCF, 71% of Asian patients achieved symptomatic remission compared to the overall population (n = 172/303, 56.8%). Improvements in mean (standard deviation) PANSS and PSP total scores from baseline to LOCF in Asian patients and overall population were clinically significant. A lower proportion of Asian patients had ≥ 1 psychiatric hospitalization after PP3M treatment (n = 1/70, 1.4%) than during the 12 months before (n = 12/70, 17.1%); compared with patients in the overall population after (n = 8/303, 2.6%) and before PP3M treatment (n = 37/303, 12.2%). The overall incidence of treatment-emergent adverse events across Asian patients was 62.9% compared to 53.1% in the overall population. Safety findings were consistent with the known safety profile of PP3M. Conclusion: Our findings confirm existing evidence on the efficacy and tolerability of PP3M in Asian patients with stable schizophrenia over 12 months of treatment.

Changes in Habitat Use by Female Japanese Pipistrelles (Pipistrellus abramus) during Different Stages of Reproduction Revealed by Radio Telemetry

Chung, Chul Un,Kim, Sung Chul,Jeon, Young Shin,Han, Sang Hoon The Korean Environmental Sciences Society 2017 한국환경과학회지 Vol.26 No.9

We analyzed how foraging area use changed in female Pipistrellus abramus during the breeding season. Radio tracking was used to follow 12 female P. abramus in Gyeongju City, from 2013 to 2015. We followed three bats in each of four stages of reproduction: early pregnancy, late pregnancy, lactation, and post-lactation. Our data showed that the usable area of a foraging site and the area that was actually used by bats in that site were different, and foraging site use also differed according to stage of reproduction. The bats used arable land the most, with use rates of 57%, 40.4%, and 73.2% during early pregnancy, late pregnancy, and lactation, respectively. Bats in a post-lactation state did not use arable areas at all and instead foraged over bodies of water 90% of the time. There was no difference in the use of each foraging environment between bats in early pregnancy and late pregnancy. However, bats in late pregnancy and those that were lactating did use arable land to different extents, and bats that were lactating and those that were post-lactation also used arable land and bodies of water to different extents.

Associations of fatty acids with cognition, psychopathology, and brain-derived neurotrophic factor levels in patients with first-episode schizophrenia and related disorders treated with paliperidone extended release

Chung, Young-Chul,Cui, Yin,Sumiyoshi, Tomiki,Kim, Min-Gul,Lee, Keon-Hak SAGE Publications 2017 Journal of psychopharmacology Vol.31 No.12

Validation of the Korean version of the Eppendorf Schizophrenia Inventory as a screening measure to detect adolescents at ultra-high risk for psychosis.

Chung, Young-Chul,Kang, Nam-In,Im, Yong-Jin,Kim, Sung-Wan,Cho, In Hee,Lee, Young Moon,Kwon, Jun Soo Blackwell Publishing Asia 2013 Early intervention in psychiatry Vol.7 No.1

<P>No validated self-report scale is available for use as a screening tool to detect non-help-seeking adolescents at ultra-high risk (UHR) for psychosis in a community setting. The study aims to examine the reliability and validity of the Korean version of the Eppendorf Schizophrenia Inventory (K-ESI) for assessing adolescents at UHR for psychosis in a community setting.</P>

Molecular Cloning and Expression of Cellulase of Gene of Pseudomonas sp. in Escherichia coli

Chung, Young Chul,Kim, Yang Woo,Kang, shin Kwon,Rho, Jong Su,Sung, Nack Kie 한국산업미생물학회 1990 한국미생물·생명공학회지 Vol.18 No.6

Cellulase 복합체와 xylanase를 동시에 분비하는 Pseudomonas sp. LBC 505와 CYC 10의 cellulase 유전자를 pUC19를 사용하여 E. coli에 클로닝시켰다. Congo red 염색시 노란색 환을 형성하는 대장균 형질전환체에서 0.7kb-와 4.6kb-HindⅢ 단편을 함유한 재조합 플라스미드 pLC1과 pLC2를 각각 분리하였다. DNA hybridization 실험에서 pLC1과 pLC2는 Pseudomonas sp. LBC 505와 CYC 10 유래임이 각각 밝혀졌고, lmmunoassay 실험에서도 유사성이 인정되었다. pLC1을 함유하고 있는 대장균은 cellulase의 24%를 세포외로 분비하였고, 효소활성은 모균주에 비해 1.4배 증가하였다. pLC1과 pLC2의 효소학적 성질도 모균주와 동일하였으며, 기질특이성과 HPLC로 유리당을 분석한 결과, 클로닝된 유전자는 endo type인 것으로 나타났다. The genes for cellulases of Pseudomonas sp. LBC505 and CYC10, potent cellulase complex-producing strains, were cloned in Escherichia coli with pUC19. Recombinant plasmids pLC1 and pLC2 were isolated from transformants producing cellulase by congo red staining, and their genes cloned were 0.7 kb and 4.6 kb HindⅢ fragments, respectively. The inserts of pLC1 and pLC2 were hybridized to chromosomal DNAs digested with HindⅢ from Pseudomonas sp. LBC505 and CYC10, respectively. Immunodiffusion assays revealed that pLC1-and pLC2-encoded cellulase showed similarity with that of host strains. About 24% of cellulase activity was observed in the extracellular fraction of E. coli carrying pLC1, and its activity was higher about 1.4 times than that of LBC505. The enzymatic properties of pLC1 and pLC2 encoded cellulase were the same as those of cellulase from host strains. HPLC analysis and substrate specificity showed that cellulases were the same as those of cellulase from host strains. HPLC analysis and substrate specificity showed that cellulases cloned were endocellulase.

Early predictors of a clinical response at 8 weeks in patients with first-episode psychosis treated with paliperidone ER

Chung, Young-Chul,Cui, Yin,Kim, Min-Gul,Kim, Yun-Jeong,Lee, Keon-Hak,Chae, Soo-Wan SAGE Publications 2016 Journal of psychopharmacology Vol.30 No.8

<P>Identification of early clinical markers that predict later treatment outcomes in first-episode psychosis is highly valuable. The present study was conducted to determine the best time at which to predict the late treatment response in first-episode psychosis patients treated with paliperidone extended release (ER), the factors predicting early treatment responses (at Week 2 and Week 3) and the relationships between the paliperidone ER plasma concentrations at Week 2 and Week 3, and the treatment responses at Week 2, Week 3 and Week 8. Various criteria for assessing treatment response were employed. We determined the plasma paliperidone concentrations at Week 2 and Week 3, using validated high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS). The treatment response at Week 3 optimally predicted the later (Week 8) response, in terms of negative predictive value (NPV). Independent predictors for good treatment responses at Week 2 and Week 3 were: Female gender, a higher educational level, a higher Positive and Negative Syndrome Scale (PANSS) excited score, and/or a shorter duration of untreated psychosis (DUP). The plasma paliperidone concentration at Week 3, but not Week 2, was a significant predictor of the late treatment response at Week 8. These results may help appropriate clinical decision-making for early non-responders after having their first episode of psychosis.</P>

Varying appearances of cholangiocarcinoma: radiologic-pathologic correlation.

Chung, Yong Eun,Kim, Myeong-Jin,Park, Young Nyun,Choi, Jin-Young,Pyo, Ju Yeon,Kim, Young Chul,Cho, Hyeon Je,Kim, Kyung Ah,Choi, Sun Young The Society 2009 Radiographics Vol.29 No.3

<P>Intrahepatic cholangiocarcinoma is the second most common primary hepatic tumor. Various risk factors have been reported for intrahepatic cholangiocarcinoma, and the radiologic and pathologic findings of this disease entity may differ depending on the underlying risk factors. Intrahepatic cholangiocarcinoma can be classified into three types on the basis of gross morphologic features: mass-forming (the most common), periductal infiltrating, and intraductal growth. At computed tomography (CT), mass-forming intrahepatic cholangiocarcinoma usually appears as a homogeneous low-attenuation mass with irregular peripheral enhancement and can be accompanied by capsular retraction, satellite nodules, and peripheral intrahepatic duct dilatation. Periductal infiltrating cholangiocarcinoma is characterized by growth along the dilated or narrowed bile duct without mass formation. At CT and magnetic resonance imaging, diffuse periductal thickening and increased enhancement can be seen with a dilated or irregularly narrowed intrahepatic duct. Intraductal cholangiocarcinoma may manifest with various imaging patterns, including diffuse and marked ductectasia either with or without a grossly visible papillary mass, an intraductal polypoid mass within localized ductal dilatation, intraductal castlike lesions within a mildly dilated duct, and a focal stricture-like lesion with mild proximal ductal dilatation. Awareness of the underlying risk factors and morphologic characteristics of intrahepatic cholangiocarcinoma is important for accurate diagnosis and for differentiation from other hepatic tumorous and nontumorous lesions.</P>