Preparation of petroleum impregnating pitches from pyrolysis fuel oil using two‑step heat treatments

Jong‑Eun Choi,Seunghyun Ko,Young‑Pyo Jeon 한국탄소학회 2019 Carbon Letters Vol.29 No.4

Petroleum-based impregnating pitches were prepared from pyrolysis fuel oil (PFO) using a two-step heat treatment without a separation process. The pressurized heat treatment, the first step, was used to improve the properties of the pitches and enhance the product yield by promoting the cracking and polymerization of the components in the PFO. An atmospheric heat treatment as the second step was used only to synthesize the impregnating pitches from the liquid pitches prepared during the first step. The prepared impregnating pitches had the properties of a commercial petroleum-based impregnating pitch. The impregnation performance was evaluated by HT-XRD and an impregnation test. The HT-XRD results showed changes in the stacked structure of the pitches at the impregnation temperature. The bulk density of the carbon block was increased to 14.3% and the porosity was reduced by 10.3% after the impregnation/recarbonization process. The high reaction temperature during the first step induced the formation of quinoline insoluble (QI) components during the second step of the treatment, and the QI components adversely affected the impregnation process.

韓國의 人口再分布에 관한 計量的 分析

崔鍾碩,장은선 충남대학교 1996 忠南科學硏究誌 Vol.23 No.1

Several projects for the national economic development plannings since 1960's have brought a tremendous change in the whole nation socially, economically as well as geo-demographically. Since 1975's, advanced industrialization with high technology, achieving a highly economic development, has accelerated urbanization, which on the other hand resulted in a serious lack of labor in the rural area. This serious unbalanced distribution of the population between the urban and the rural area has caused not only political and societal gap between the two areas but also the inefficient use of the land. We, with a very dense population, think that the above problems could be solved partly through strong policies of restraint on population growth and on population migration into the urban area. This study has been done as a base for the policies in the followings. 1. In order to observe the phenomenon of population migration, we analyze time series intra and inter-migration and total migration. 2. To investigate the cyclic phenomenon, seasonal variation analysis on one-year base is considered additionally. 3. We investigate, in macro sense, redistribution of population by showing the migration trend based on the center of population gravity and that of geographic gravity. 4. We end up this study with the possible suggestions for the policy making on the population problem after discussing some predictions of migration trend.

신생아 말초혈액 T 림프구의 아형 분석

최두영,김종덕,장선일,이신은,조성경,정헌택 최신의학사 1990 最新醫學 Vol.33 No.12

항만하역 근로자들의 직업적 특성과 사회심리적 스트레스에 관한 연구

최은경,이종태,손혜숙,이성훈 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.5

Objective : The objective of this study is to evaluate the job characteristics of container terminal workers by applying the Job Strain model, and to assess the relationship among the general characteristics, job characteristics and psychosocial distress. Methods and Material : A self-administrated questionnaire survey was performed in Busan. The subjects were consisted of 100 white-collar workers and 100 blue-collar workers. We used Karaseks Job Content Questionnaire for evaluation of the job characteristics and Psychosocial well-being index (PWI) for measuring the extent of their psychosocial stress. Results : In white-collar workers, the skill discretion, created skill, decision-making authority, decision-making latitude, psychological job demand, and supervisor support of the job characteristics were significantly high, while in blue-collar workers physicalexertion was significantly high. PWl reveals that blue-collar workers were mere stressed than white-collar workers, especially, the factor 2, 3 and 4 were significantly increased; whereas, in white-collar workers, only the index of factor 1 was significantly increased. And PWl scores were significantly increased in the lower social support and psychological job demand. blue-collar workers had increased odds ratio of 2.66(95% CI:1.11-6.41) compared with white-collar workers. The unmarried workers increased odds ratio of 3.54(95% CI;1.18-10.62) compared with married workers. And workers who have not own house increased odds ratio of 2.35(95% CI;1.15-4.79) compared with workers who have own house. Particularly, odds ratio of work-shift in blue-collar workers was 11.10(2.14-57.64). (multiple logistic regression analysis PWI). Conclusion : The results of this study correspond with the fact that The more job demand is high and Job control is low, the more job stress is high. Job stress of blue-collar workers was comparatively higher than that of white-collar workers, sleeping, smoking, and work shifting turned out to be a main cause that increases stress. Therefore, in order to decrease the job stress, a health promotion program to change the health behaviors should be activated and an organized job stress management program should be introduced. Especially, working condition for blue-collar such as physical exertion and work-shift should be improved.

한국인 제2형 당뇨병 환자의 골격근에서 인슐린 신호전달체계의 결함

최준혁,이관우,김효정,이동훈,이종우,김정은,엄현채,김경미,최성이,정윤석,김현만 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.5

연구배경: 제2형 당뇨병에서 나타나는 인슐린 저항성은 간, 지방, 근육 같은 말초조직에서 인슐린의 작용이 떨어지는 것을 말한다. 제2형 당뇨병의 발생기전에 인슐린 저항성과 인슐린 분비능 저하가 같이 관여함은 잘 알려진 사실이다. 인슐린의 세포내에서의 저항성을 규명하기 위한 인슐린의 세포내 신호전달체계에 대한 연구가 활발히 진행되고 있으며 몇몇 연구에서 인슐린 저항성을 가진 골격근육에서 IRS와 관련된 PI3-kinase의 활성감소와 Akt kinase의 활성감소를 보고하고 있으나 아직까지 명확하게 그 기작이 설명되어지지 않고 있다. 본 연구에서는 정상성인, 제2형 당뇨병 환자를 대상으로 경구당부하검사 및 인슐린 클램프검사를 시행하고 인슐린 클램프 검사시 대상인의 근육을 채취하여 인슐린 신호전달 체계(IR-β, IRS, Akt(PKB, Rac) kinase, GSK-3)를 연구하였다. 방법: 연구대상자는 한국인으로서 경구당부하검사상 정상인 및 당뇨병 환자 각각 11명, 9명을 대상으로 하였으며, 정상인은 건강인으로 과거력상 당대사에 영향을 줄 질환이 없고, 현재 당대사에 영향을 줄 약물 복용 및 다른 소견이 없는 경구당부하검사상 정성 내당능을 보이는 대상자로 하였다. 당뇨병환자는 모두 제2형 당뇨병 환자로 이환기간이 만 5년 이내인 경우로 하고, 인슐린으로 치료하는 대상자는 제외하도록 하였다. 대상자의 연령, 체질량지수, 체지방량, 공복시 총콜레스테롤, 중성지방, 고밀도지단백 콜레스테롤 및 HbA1c, 인슐린, C-peptide를 측정하였고, "HOMA model"을 이용하여 베타세포의 기능와 인슐린저항성 정도를 평가하였다. 정상혈당클램프 검사(euhlycemic hyperinsulinemic clamp test)를 시행하고 인슐린 투입 전과 인슐린 투입 30분후, 두차례에 걸쳐 대퇴부 근육생검을 실시한후 western 법으로 IR-β, IRS, Akt kinase, GSK-3의 인산화량을 측정하였다. 결과: 정상인 11명과 당뇨병 환자 9명을 대상으로 하였으며 대상자의 평균 연령, 평균 체질량지수, 체지방량, 허리/엉덩이 둘레의 비(waist hip ratio; WHR)는 두 군간에 차이가 없었다. 평균 공복혈당은 정상군 98.0±0.3㎎/dL, 당뇨병군 208.1±16.5㎎/dL(p<0.05), HbA1c는 정상군 5.4±0.5%, 당뇨병군 9.2±0.6%(p<0.05)였다. "HOMA model"을 이용한 베타세포의 기능과 인슐린저항성은 정상군 56.4±8.5%, 1.4±0.2, 당뇨병군 72.2±52.3%(p<0.01), 10.2±6.3(p<0.01)였으며 정상혈당클램프 검사상 포도당 이용률은 정상군 8.2±0.6㎎/㎏/min, 당뇨병군 3.7±1.1㎎/㎏/min(p<0.01)로 정상군과 당뇨병군간에 유의한 차이를 나타내었다. Western blot법으로 IR-β, IRS, Akt kinase, GSK-3의 인산화량을 인슐린 투입전과 인슐린 투입 30분후 측정하였을 때 IR-β에서는 정상군이 103.9±2.3에서 241.3±18.6, 당뇨군이 108.9±2.2에서 198.7±6.3으로 증가하였다(p=NS). 이는 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 통계적인 차이가 없었다. IRS에서는 정상군이 111.6±7.3에서 295.6±17.2, 당뇨군이 114.5±6.1에서 222.0±23.2로 증가하였으며(p<0.05), 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 약 24% 감소하였다. Akt kinase에서는 103.4±6.0에서 416.8±29.5로 증가하였으며(p<0.01), 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 약 43% 감소하였다. GSK-3에서는 정상군이 107.7±6.7에서 595.7±28.1, 당뇨군이 104.3±4.8에서 443.3±12.9로 증가하였으며(p<0.01), 인슐린 투입후 당뇨병군이 정상군과 비교하여 인산화량의 증가정도가 약 25% 감소하였다. 결론: 제2형 당뇨병 환자에서 정상인과 비교하여 인슐린 자극후 IR-β는 인산화량의 증가정도가 큰 차이가 없었으나, IRS, Akt kinase, GSK-3에서는 인산화량의 증가 정도가 감소되는 것으로 보아 상위 인슐린 신호전단체계부터 결함이 있는 것으로 생각된다. Background: The glucose uptake rate is the limiting step in glucose utilization and storage. The failure of insulin to stimulate glucose uptake in muscle appears to be a primary defect of insulin resistance. This study was undertaken to examine the effect of physiological hyperinsulinemia on the phosphorylation of the insulin receptor (IR-β), insulin receptor substrate (IRS), Akt kinase and GSK-3 in isolated skeletal muscle, in people with type 2 diabetes(n=9) and control subjects(n=11). Methods: 75g OGTT and euglycemic hyperinsulinemic clamp test were done. And vastus lateralis muscle was obtained before and 30 min into the euglycemic clamp. Western blots were performed for tyrosine phosphroylation of insulin receptor substrate (IRS) and phosphorylation of the insulin receptor(IR-β), Akt and GSK-3. Result: There were no statistical differences in the mean age, BMI and body fat between the control subjects and diabetic patients. The fasting blood sugar and HbA_1c in controls and diabetic patients were 98.0±0.3 and 208.1±16.5ng/dl, and 5.4±0.5 and 9.2±0.6%, and 1.4±0.2 in the control subjects, and 72.2±52.3%(p<0.01) and 10.2±6.3(p<0.01) in the diabetic patients, respectively. The insulin resistance from the euglycemic hyperinsulinemic clamp test were 8.2±0.6㎎/㎏/min and 3.7±1.1ng/㎏/min in the control subjects and in the diabetic patients, respectively(p<0.01). Compared with the normal controls, insulin-stimulated IR phosphorylation was no different to that in the diabetic patients. However, insulin-stimulated IRS phosphorylation, insulin-stimulated Akt phosphorylation and insulin-stimulated GSK-3 phosphorylation were reduced in the diabetic patients compared with the normal controls by 24, 43 and 25%, respectively(p<0.05). Conclusion: In Korean type 2 diabetic patients, the insulin resistance may be due to the impairment of the upstream insulin signal molecular network. Further studies will focus on determining whether these signaling defects are the cause of the development of insulin resistance, or secondary to the altered metabolic state, associated with type 2 diabetes mellitus (J Kor Soc Endocrinol 17:685∼697, 2002).

수평 매복된 상악 견치의 교정적 견인

최형준,이종은,이제호,이종갑 大韓小兒齒科學會 2003 大韓小兒齒科學會誌 Vol.30 No.4

치아 매복은 구강점막이나 악골내에서 치아의 맹출이 중지된 상태를 의미하며, 제 3구대구치와 상악 견치에서 호발한다. 상악 견치의 매복은 주로 측절치가 상실되거나 왜소한 경우와 연관성이 높지만 치배의 위치 이상과 같이 유전적인 요소와도 관련될 수 있다. 매복치는 심미적, 기능적으로 여러 가지 문제점을 야기하므로 조기에 진단하여 치료하는 것이 중요하며, 매복치의 상태에 따라서 치료 방법을 적절하게 선택하여야 한다. 본 증례는 11세 여아에서 구개측으로 수평 매복된 상악 우측 견치의 치료를 보고한 것으로, 매복치는 외과적 수술을 동반한 교정적 견인 방법을 사용하여 기능적, 심미적으로 회복되었다. 견인 치료는 매복 견치의 맹출 공간을 확보하면서 이루어졌으며, 치료 종료 후 매복 견치는 치근 흡수와 같은 합병증 없이 적절한 부착치은을 확보하여 양호하게 위치되었다. Tooth impaction is defined as a cessation of the eruption of a tooth at the level of the oral mucosa or alveolar bone. Maxillary canines are the most frequently impacted teeth next to the third molar. Maxillary canine impaction is associated with congenital missing of lateral incisors, peg lateralis and genetic factors such as ectopic positioning of a tooth germ. The clinicians have an important role in early detectionof tooth impaction for prevention of esthetic and functional problems. There are specific methods to treat impacted tooth for different conditions. In this case, an 11-year-old girl with a horizontally impacted maxillary right canine in a palatal position was treated through orthodontic traction along with surgical button attachment procedure. On regaining of eruption space, canine traction was performed. At the completion of treatment, the canine was positioned fairly within the arch with proper keratinized gingiva and complications such as root resorption were not observed.

디이젤기관의 흡입선회유동에 관한 연구

정동화,최은순,박상규 麗水水産大學校産業技術硏究所 1992 産業基術硏究所 論文集 Vol.1 No.-

Enhancement of performance of engine depends upon how perfectly combustion is effected, and air swirl is a factor contributing to this aim. In this paper, the variation of induction air swirl according to intake port shapes is studied by steady flow test. As a result of the steady flow test, using various shapes of intake port the following points are clarified. 1. Air swirl in actual engine cylinder can be fully estimated by steady flow test. 2. A valve position can have a substantial effect upon swirl. 3. The change of port inlet area has an effect on the variation of air swirl.

조기위암의 형태학적인 분류에 따른 임파절 전이 양상

최은서,강길,박정희,장정환,김권천,김경종,민영돈 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.1

Currently, in the limited cases of early gastric cancer (EGC), endoscopic mucosal resection (EMR) is used for curative treatment. However, its completeness is still controversial. The purpose of this study was to review the suggested indications of EMR. We retrospectively analyzed 234 patients with EGC who underwent curative (RO) gastrectomy. The enrolled cases were further classified into mucosal and submucosal types, and mucosal EGC were further classified according to the size, gross type and histologic pattern. 133 patients had mucosal cancers and 101 patients submucosal. The overall incidence of positive lymph node was 14.1% (33/234), the incidence of mucosal cancer was 8. 3% (11/133), which was significantly lower than that of submucosal, 22% (22/101). Of 133 patients with mucosal EGC, 90 were smaller than 2㎝ in size and the incidence of lymph node metastasis was 5.6% (5/90), compared to 43 of larger than 2㎝ with the incidence of 14% (6/43). According to the gross type classification of mucosal cancer, incidence of lymph node metastasis in protruded type (EGC type Ⅰ, Ⅱa, Ⅰ+Ⅱa) was 15.4% (4/26), nat type(EGC type Ⅱb) 2. 9% (1/35), depressed type (EGC type Ⅱc, Ⅲ) 8.3% (6/72). Lymph node metastasis in differentiated type of mucosal cancer was 6.9% (5/72) and undifferentiatcd type 9.8% (6/61). In this study, there was no single indication free from lymph node metastasis, It is thought that the selection of EMR for the curative treatment of EGC should be considered carefully and more clinical studies with long-term follow up are necessary for EMR to be generally acceptable.

개의 아토피 피부염에 대한 Leflunomide의 임상적 적용 1례

홍은지,윤기영,서경원,최호정,정성목,송근호,조종기,박성준 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2012 動物醫科學硏究誌 Vol.19 No.1

A Shih-tzu(8-year-old, castrated male) was referred to the Veterinary Medical Teaching Hospital of Chungnam National University with the history of relapsing pruritus, recurrent dermatitis. On the physical examination, generalized erythema, otitis externa, alopecia and lichenification were observed. Using Favrot's criteria for diagnishing atopic dermatitis, 7 criteria were satisfied out of 8 criteria. After treatment for infection, intradermal skin test was performed(positive allergen : Df, Dp). And then immunotherapy was performed, but clinical signs were not getting better. Next treatment of glucocorticoid shown little improvement of clinical signs, and adverse effect(diarrhea) was shown after cyclosporine application. So application of leflunomide which is used for human atopic dermatitis treatment in some case was planned. After 6 months of application of leflunomide, clinical signs were decreased gradually.

HIV 감염/AIDS을 처음 진단받은 환자들의 특성과 임상에서 보편적인 HIV 검진의 가치

김종화,김태형,추은주,전민혁,서성우,이용관,최문한 순천향의학연구소 2008 Journal of Soonchunhyang Medical Science Vol.14 No.2

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