NR과 SBR 가황물의 경도와 강성도에 대한 온도의 영향

진현호 ( Hyun Ho Jin ),홍창국 ( Chang Kook Hong ),조동련 ( Dong Lyun Cho ),강신영 ( Shin Young Kaang ) 한국고무학회 2007 엘라스토머 및 콤포지트 Vol.42 No.3

본 연구에서는 고무제품의 수치 안정성과 성능유지에 직접적으로 영향을 미치는 중요한 특성 중 하나인 온도변화에 따른 고무재료의 경도변화를 고찰하였다. 새롭게 제작된 International Rubber Hardness Degree(IRHD, Normal type) 경도측정 시험기를 사용하여 미충전된 NR과 SBR시편의 여러 온도에서 경도변화를 측정하였으며 Young`s modulus 값과 비교하였다. NR과 SBR 모두 유리전이온도 근처에서 경도와 Young`s modulus의 급격한 변화를 보였다. 온도가 증가함에 따라 경도와 Young`s modulus 값이 증가하는 경향을 보였으며 이는 분자의 운동성과 엔트로피 영향으로 해석할 수 있다. 카본블랙과 실리카가 충전된 NR과 SBR의 경우 충전제의 함량이 증가함에 따라 경도에 미치는 온도의 영향이 감소함을 관찰하였다. Hardness of rubbery materials, which is important for dimensional stability and product performance, was investigated upon temperature change in this study. A newly developed IRHD (International Rubber Hardness Degree) tester was used to measure the hardness changes of NR and SBR specimens at various temperatures and the hardness values were compared with the Young`s modulus. The hardness and Young`s modulus of NR and SBR showed an abrupt change near the glass transition temperatures. The hardness and Young`s modulus were increased by increasing temperature due to the increased random chain conformation of molecules. The effect of temperature on hardness and Young`s modulus of NR and SBR specimens filled with carbon black and silica was decreased by increasing filler content.

Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

<P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

급성 췌장염의 시대적 변화

김배영(Bai Young Kim),김효종(Hyo Jong Kim),정형근(Hyung Keun Chung),김영관(Young Kwan Kim),동석호(Seok Ho Dong),김병호(Byung Ho Kim),이정일(Jung Il Lee),장영운(Young Woon Chang),장린(Rin Chang) 대한내과학회 1993 대한내과학회지 Vol.45 No.5

N/A Background: According to the rapid changes in social environment such as increasing alcohol consumption and the marked improvement in diagnostic technique, we expect that there have been major changes in various aspects of acute pancreatitis during the recent 12 years in Korea. Methods: The medical records of 317 patients with acute pancreatitis diagnosed from 1980 through 1992 were reviewed about clinical, laboratory and radiological findings in the three different time period. Results: 1) There has been an increasing incidence in male sex about three folds. 2) There has been an increasing trends in the duration of hospitalization. 3) A significant increase was observed in the proportion of patients with alcoholic pancreatitis in the three different time period; 26.9%, 45.7%, 50.7% respectively. 4) The complication rates have been slightly increased in the three different time period; 46.3%, 47.1%, 59.1% respectively. But, the type of complications has not been changed. 5) There is increasing severity in non-gallstone group, but no significant differences in gallstone group. There is a declining trends in the number of patients with muld severity index, but increasing trend in the number of patients with moderate severity index in non-gallstone group. 6) There was no significant differences in mortality rate. Conclusions: There has been major changes in the etiology ans severity of acute pancreatitis from 1980 through 1992. Especially, significant increase in the proportion of patients with alcoholic pancreatitis was observed in the three differnt time period. These results might be due to socioeconomic changes.

가속도계를 이용한 재료의 영계수 측정방법

손창호(Sohn, Chang-Ho),박진호(Park, Jin-Ho),윤두병(Yoon, Doo-Byung),정의필(Chong, Ui-Pil),최영철(Choi, Young-Chul) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.11

For the description of the elastic properties of linear objects a convenient parameter is the ratio of the stress to the strain, a parameter called the Young's modulus of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Conventional method for estimating Young's modulus measured the ratio of stress to corresponding strain below the proportional limit of a material using a tensile testing machine. But the method needs precision specimens and expensive equipment. In this paper, we proposed method for estimating Young's modulus using accelerometer. The basic idea comes from that the wave velocity is different as the Young's modulus. To obtain Young's modulus, a group velocity is obtained. It is difficult to measure group velocity. This is because plate medium has a dispersive characteristics which has different wave speed as frequency. In this paper, we used Wigner-Ville distribution to measure group velocity. To verify the proposed method, steel and acryl plate experiments have been performed. Experimental results show that the proposed method is powerful for estimating Young's modulus.

만성 두부외상 환자에서 99mTc - HMPAO Brain SPECT의 임상적 유용성

서정호(Jung Ho Suh),김동익(Dong Ik Kim),정태섭(Tae Sub Chung),이종두(Jong Doo Lee),박창윤(Chang Yoon Park),정진일(Jin Ill Chung),김영수(Young Soo Kim) 대한핵의학회 1992 핵의학 분자영상 Vol.26 No.1

N/A Minima1 deterioration of cerebral perfusion or microanatomical changes were undetectable on conventional Brain CT or MRI. So evaluation of focal functional changes of the brain parenchyme is essential in chronic head injury patients, who did not show focal anatomical changes on these radiological studies. However, the patients who had longstanding neurologic sequelae following head injury, there had been no available imaging modalities for evaluating these patients precisely. Therefore we tried to detect the focal functional changes on the brain parenchyme using Tc-99m-HMPAO Brain SPECT on the patients of chronic head injuries. Twenty three patients who had suffered from headache, memory dysfunction, personality change and insomnia lasting more than six months following head injury were included in our cases, which showed no anatomical abnormalities on Brain CT or MRI. At first they underwent psychological test whether the symptoms were organic or not. Also we were able to evaluate the cerebral perfusion changes with Tc-99m-HMPAO Brain SPECT in 22 patients among the 23, which five patients were focal and 17 patients were nonfocally diffuse perfusion changes. Thus we can predict the perfusion changes such as local vascular deterioration or functional defects using Tc-99m-HMPAO Brain SPECT in the patients who had suffered from post-traumatic sequelae, which changes were undetectable on Brain CT or MRI.

흰쥐에서 사염화 탄소(CCl4)에 의한 간섬유화의 유도

김병호,이정일,김효종,김영관,장린,동석호,장영운,송일한 대한소화기학회 1992 대한소화기학회지 Vol.24 No.6

Experimental model of hepatic fibrosis is importent contributions to the understanding of cellular and molecular mechanisms underlying excessive accumulation of extracellular matrix in the liver. Carbon tetrachloride (CCl₄) is one of the oldest and most widely used toxin for experimental induction of hepatic fibrosis in laboratory animals. In this study, We intended to induce the hepatic fibrosis in the rat by the intragastric CCl₄/ phenobarbtal treatment once a week for 12 weeks and the administration dosage of CCl₄ in each week was determined by the daily body weight change. Liver function and histologic change were examined just after 12-week treatment in group Ia (9 rats, Phenobarbital treatment only) and II (18 rats, CCl₄/phenobarbital treatment), and liver function and the irreversibility o histologic change were examined 12 weeks after 12-week treatment in group Ib (9 rats, phenobarbital treatment only) and III (18 rats, CCl₄/phenobarbital treatment). 1) Death rate after 12-week treatment was 11% in group Ⅰ, 56% in group Ⅱ and 50% in group Ⅲ. and the highest rate was at 1 week. that is 33 o each in group Ⅱ and Ⅲ. 2) Tatal protein, alkaline phosphatase, alanine aminotransferase and portal venous pressure were significantly increased in group Ⅱ compared with that in group Ⅰa, but it was only portal venous pressure that was increased in group Ⅲ than in group Ⅰb, 3) The gross finding of micronodular change was shown in 88% of group Ⅱ, 71% of group Ⅲ, but none of group Ⅰ. The microscopic finding of hepatic fibrosis was found in all of group Ⅱ and Ⅲ, but none of group Ⅰ. The severe form of hepatic fibrosis suggesting cirrhosis was found in group Ⅱ and Ⅲ, 12% and 29% respectively. In our study, mortality rate was high within 1 week after CCl₄ treatment, which resulted in half survival rate after 12-week treatment. We also experienced the loin rate of severe fibrotic changes in surviving rats. In the future, in order to produce a severe irreversible fibrotic change with low mortality in inducing hepatic fibrosis with CCl₄/phenobarbital treatment in the rat, adequate detemination of the initial dose of CCl₄ and appropriate choice of administration route of CCl₄ were thought to be needed.

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.

흰쥐에서 갑상샘 절제 후 재생에 따른 세포 및 세포사이물질의 변화

황영일,정용환,이왕재,황덕호,유영복,김혜숙,장가용 대한해부학회 1997 Anatomy & Cell Biology Vol.30 No.4

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

강대영,송규상,최정목,노승무,정경수,오정연,김진향,양준묵,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

속박 (束縛) 과 침수 (浸水) 로 유도된 흰쥐의 스트레스성 급성 (急性) 위점막병변 (胃粘膜病變) 발생에 있어서 위산분비의 (胃酸分泌) 역할

민영일(Young Il Min),박충기(Choong Kee Park),장린(Rin Chang),김병호(Byung Ho Kim),장영운(Young Woon Chang),이정일(Jung Il Lee),박승준(Seung Joon Park),정주호(Joo Ho chung),정지창(Jee Chang Jung) 대한소화기학회 1989 대한소화기학회지 Vol.21 No.1

N/A The possible roles of gastric acid secretion in the pathogenesis of stress ulcers induced by restraint with water-immersion for 7 hours in pylorus-ligated rats were investigated. Control rats with pylorus-ligation only did not show any gastric mucosa} lesion, and their mean gastric acid output was 449.2 ± 36.1 umol/rat. In contrast, the stressed rats, group II, showed multiple, punctate and hemorrhagic erosions in gastric mucosa, and mean gastric acid output was decreased to the level of 253.7 ± 27.3 umol/rat. Subcutaneous administration of histamine(40 mg/kg every 2.5 h for a total three times) to stressed rats augmented the lesion with severe multiple, linear and hemorrhagic erosions and mean acid output increased significantly (328.1 ± 31.5 umol/, p<0.005) compared with group II. Pretreatment with rantidine(20 mg/kg) or prostaglandin E2 (30 ug/kg) before exposure to stress reduced gastric lesion formation slightly with no significance. In ranitidine pretreated rats, mean gastric acid output was decreased significantly (120.1 ± 15.3 umol/rat, p<0.005) compared with group II. However, in prostaglandin pretreated rats, mean gastric acid output showed no significant changes. Therefore, it is suggested that increased gastric acid secretion seems to be an aggravating or a permissive factor rather than a major factor in the pathogenesis of stress-induced gastric mucosal lesions.