Effect of low processing rate on homogeneous microstructural evolution of polyacrylonitrile‑based carbon fibers

Doo‑Won Kim,Dae Ho Kim,Sung Ryong Kim,Bo‑Hye Kim,Yun Hyuk Bang,Duck Joo Yang,Go Bong Choi,Yoong Ahm Kim,Kap Seung Yang 한국탄소학회 2019 Carbon Letters Vol.29 No.5

This study demonstrates that low processing rate for producing polyacrylonitrile (PAN)-based carbon fiber is a critical to obtain a homogeneous radial microstructure with high resistance to oxidation, thereby resulting in their improved mechanical strength. The dry-jet wet spun PAN organic fibers were processed (e.g., stabilized and then carbonized) utilizing two different rates; one is 1.6 times longer than the other. The effect of processing rate on the microstructural evolutions of carbon fibers was analyzed by scanning electron microscopy after slow etching in air, as well as Raman mapping after graphitization. The rapidly processed fiber exhibited the multilayered radial structure, which is caused by the radial direction stretching of the extrusion in the spinning. In case of the slowly processed fiber, the layered radial structure formed in the spinning process was changed into a more homogeneous radial microstructure. The slowly processed fibers showed higher oxidation resistance, higher mechanical properties, and higher crystallinity than the rapidly processed one. Raman mapping confirmed that the microstructure developed during spinning was sustained even though fiber was thermally treated up to 2800 °C.

矮化劑 處理가 바나나의 生育 및 收量에 미치는 影響

李宗錫,姜榮吉,朴才昊,韓海龍,文斗吉,金龍湖 濟州大學校 亞熱帶農業硏究所 1990 亞熱帶農業硏究 Vol.7 No.-

바나나에 알맞은 矮化劑를 選拔하고자 몇종의 矮化劑를 Dwarf Cavendish에 처리하였던 결과를 요약하면 다음과 같다. 1. 주당 80mg 이하의 paclobutrazol 土壤灌注 처리는 草長, 莖葉特性, 果實收量, 果實特性 등에 영향을 주지 않았다. 200mg 이상 처리구에서는 草長과 假莖長이 단축되는 경향을 보였고 果梗長은 유의성 있게 단축되었으나 다른 莖葉特性이나 果實收量, 果實特性은 무처리구와 큰 차이가 없었다. 2. 주당 20mg의 ancymidol 土壤灌注에 의해서 草長과 假莖長이 단축되는 경향이나 다른 莖葉特性이나 果實收量, 果實特性은 무처리구와 큰 차이가 없었다. 3. 5000ppm의 chlormequat 수용액 2회 葉面撤布區에서는 草長, 莖葉特性, 果實收量, 果實特性 등이 무처리구와 비슷하였다. 4. 草長과 假莖을 현저히 단축시키는 藥量의 矮化劑를 처리할 때 果梗이 假莖에서 빠져나오지 못할 것으로 보여 바나나에 있어서 矮化劑의 실용성은 없을 것 같다. This study was conducted to select growth retardants for bananas grown in a plastic greenhouse. The various rates of paclobutrazol(40, 80, 200 and 400mg/plant) and 20mg/plant of ancymidol were soil drenched and 5000ppm solution of chlormequat was foliarly sprayed twice. Application of less than 80mg of paclobutrazol did not affect plant height, pseudostem and leaf characteristics fruit yield and fruit characteristics. Application of 200 or 400mg of paclobutrazol tended to reduce plant height and pseudostem length and significantly shortened fruit stalk but did not affect the other characteristics. Application of 20mg of ancymidol tended to reduce plant height and pseudostem length but did not influence the other characteristics. Foliar spray of 5000ppm solution of chlormequat did not influence any measured plant traits. Application of growth retardants to bananas grown in a plastic greenhouse may not be beneficial because growth retardant rates to reduce plant height and pseudostem length significantly appear to prevent fruit stalks from fully emerging.

Acrylate기를 갖는 Polydimethylsiloxane계 코팅 액의 제조와 그 특성

박승우(Seung Woo Bak),강호종(Ho Jong Kang),강두환(Doo Whan Kang) 한국고분자학회 2014 폴리머 Vol.38 No.2

α,ω-Hydroxypropyl기를 갖는 polydimethylsiloxane을 합성하고 이를 hexamethylenediisocyanate(HDI)의 고리화 반응으로 제조된 HDI trimer와 반응시켜 말단에 이소시아네이트 기를 갖는 PDMS 변성 urethane(PSU)을 제조하였다. 이소시아네이트기를 갖는 PSU와 2-hydroxyethylmethacrylate를 urethane 반응으로 acrylate기를 갖는 PDMS변성 urethane base 수지(PSUA)를 제조하였으며, 이를 FTIR, NMR로 구조를 확인하여 분석하였다. 제조한 base 수지에 아크릴계 경화제, 광 개시제, 용매들을 혼합하여 코팅 액을 제조하였으며 이를 PET 필름에 도포하고 자외선으로 조사하여 고경도의 유연성을 갖는 코팅 막을 얻었다. 얻어진 코팅 막의 광 투과도는 89.7%, 연필경도는 3H, 접촉각은 88o였다. α,ω-Hydroxypropyl polydimethylsiloxane (HO-PDMS) was prepared by hydrosilylation of hydrogen ter-minated polydimethylsiloxane with allyl alcohol. Polydimethylsiloxane modified urethane with isocyanate group (PSU) was prepared from cyclic trimer of hexamethylenediisocyanate with HO-PDMS. PDMS modified urethane base resin with acrylic group (PSUA) was prepared from the urethane reaction of PSU with isocyanate group and 2-hydroxy-ethylmethacrylate. Their structures were characterized using FTIR and NMR. Coating materials were prepared by mixing PSUA, acrylic hardner, photo-initiator, and solvent and coated on PET film to obtain flexible and hard coating film by UV irradiation. Transparency of coating film was 89.7%, contact angle, 88o, and pencil hardness, 3H.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Omeprazole 투여시 위산분비 억제능에 대한 CYP2C19 의 영향

박수헌(Soo Heon Park),김종원(Jong Won Kim),이수연(Soo Youn Lee),최명규(Myung Gyu Choi),김재광(Jae Kwang Kim),정인식(In Sik Chung),정규원(Gyu Won Chung),선희식(Hee Sik Sun),박두호(Doo Ho Park) 대한소화기학회 2001 대한소화기학회지 Vol.38 No.6

Background/Aims: CYP2C19 has an important role in the catabolism of several proton pump inhibitors. However, the relative contribution of CYP2C19-mediated metabolism varies among the different proton pump inhibitors. We investigate to determine the effect of CYP2C19 genotype status on intragastric pH during dosing with omeprazole. Methods: The subjects were 16 healthy volunteers. Their CYP2C19 genotype status was determined by a polymerase chain reaction-restriction fragment length polymorphism method. Twenty-four-hour monitoring of intragastric acidity were performed on the day without medication and day 4 after omeprazole administration. Results: A single dose of omeprazole significantly decreased 24 hour intragastric acidity (1.7±0.3 vs. 5.1±0.4). Subjects were divided into three groups on the basis of their CYP2C19 genotype status: homozygous extensive metabolizers (Ho-EMs, n=5), heterozygous extensive metabolizers (Ht-EMs, n=6), and poor metabolizers (PMs, n=5). Median 24 hour intragastric pH in the Ho-EM group was 3.1 compared with 5.5 in Ht-EM group and 5.9 in PM group(P<0.05). The median pH during omeprazole administration was influenced by CYP2C19 genotype. On the other hand, the Helicobacter pylori infection did not influence the median intragastric pH during omeprazole administration (p= NS). Conclusions: The effects of omeprazole on intragastric acidity is influenced by the CYP2C19 polymorphism. (Korean J Gastroenterol 2001;38:399-404)

경막외 혈액 봉합술을 시행받은 자발성 두개내 저압 환자의 분석

김두식,유수봉,윤상호 고신대학교 의과대학 2009 고신대학교 의과대학 학술지 Vol.24 No.2

Background : Spontaneous intracranial hypotension(SIH) is found as a not uncommon cause of headache recently. We wanted to study its demographic characteristics, presenting symptoms and findings and the effect of autologous epidural blood patch (AEBP). Methods : We retrospectively analyzed medical records of 11 patients who were diagnosed of spontaneous intracranial hypotension and treated with AEBP from March of 2006 to October of 2009. Results : Age of patients(10 female and 1 male) was ranged from 29 to 51 years (mean 38.8 years). Their presenting symptoms included typical postural headache(11/11), nausea and vomiting(7/11), dizziness(2/11), stiff neck or neck pain(2/11), shoulder pain(2/11), and back pain(1/11). In nine patients CSF pressure was checked, CSF pressure was less than 6 cmH2O in 8 patients. In nine of eleven patients, CSF leakage was detected in cisternography. Brain MRI showed diffuse meningeal enhancement in six patients and subdural hematoma in one. VAS of postural headache decreased from 8-10(mean 9.6) to 1-5(mean 1.6) after AEBP. Conclusion : Most of the SIH patients were otherwise healthy people. It was prevalent among women, especially young adult. AEBP showed as an excellent treatment modality.

[논문]고층공동주택 스카이라인에 대한 선호도에 관한 연구 -부산시 수영강변을 대상으로-

이두휘,이성호 釜山大學校 都市問題硏究所 2004 都市硏究報 Vol.17 No.-

한국 남성의 노화에 따른 혈중 Androgen과 골밀도의 변화

김두상,김영호,이남규 大韓泌尿器科學會 2001 Korean Journal of Urology Vol.42 No.9

지상과 수중에서 전격에 의한 위험성 평가

김두현,강동규,이종호 한국안전학회 2004 한국안전학회지 Vol.19 No.2

This study presents a hazard assessment of the human body exposed to electric shock considering various parameters which affect severity of the electric shock. The present study has two research objectives; one is to analyze hazards of the human body by the electric shock both on the ground and m the water. The other is to understand the mechanism of the electric shock. In order to achieve these objectives the hazard of shock is estimated by comparing with physiological effects of electric current through the human body according to variation of shock parameters of shock circuits. The shock parameters adopted in this paper consist of body resistance, resistance of protective equipment, ground resistance, shock duration, depth of ground surface layer, reflection factor, permissible touch voltage, body current and body voltage. Besides, safety standard determining hazard degree of the human body is introduced. And hazard of the human body due to the electric shock is quantitatively assessed in consideration of data obtained by the method suggested herein, and final results are presented and discussed.

근원 불명 전이암의 예후인자와 생존율

원종호,박성규,홍대식,박희숙,김은석,최두호 순천향의학연구소 1999 Journal of Soonchunhyang Medical Science Vol.5 No.1

Purpose : Patients with cancer of unknown primary site represent 5% to 10% of all cancer patients. This study was to evaluate survival and prognostic factors of patients with malignancy of unknown origin. Materials and Methods : A retrospective analysis was done for one hundred and two patients with malignancy of unknown origin who were treated from January 1989 to December 1998. There were 52 male and 50 female patients. Age of patients ranged from 20 to 94 years (mean 58 years). Clinical presentation depended on the site of metastases. In cases of multiple metastatic sites, we selected the first apparent metastasis or the symptomatic one for which the patient was first seen. The three most frequent initial metastatic sites were peritoneum, lymph node, and liver. Median follow up period was 4 months(0-100 months) and survival rate measured form the time of diagnosis. Results : The two years survival rate was 13.6% with a median survival time of 4 months. The factors associated with the overall survival rate were the tumor marker CEA(p=0.0061), smoking history(p=0.0039), and histologic type(squamous cell carcinoma versus non-squamous cell carcinoma, p=0.0295). Marginal statistical difference was found according to performance status. No statistical differences were found according to sex, weight loss, initial metastatic site and numbers, primary lesion site, and treatment modality. Conclusion : Squamous cell carcinoma was associated with survival rate. In squamous cell carcinoma of unknown origin with good prognostic factor, especially cervical lymph node metastasis, we suggest an approach of extensive initial workup for staging and aggressive treatment.