低사이클 反引張을 받는 鋼棒의 圓孔노치底 크랙發生에 관한 硏究

孔基勳,吳世旭 東亞大學校 大學院 1981 大學院論文集 Vol.5 No.-

Many studies on fatigue crack propagation have been presented but the behavior of fatigue and its mechanism is not clarified enough yet, especially low cycle fatigue. Some experiments in this study were carried out by the method of changing stress amplitude under constant mazimum stress and low cycle pulsating tension fatigue testing on fatigue crack propagation at room temperature. Propagating cracks were observed with potical microscope on crack initiation and growth. The obtained results are summarized as follows: ⑴ Fatigue strength was higher in S-N curve as stress amplitude was decreasing, mean stress inereasing, too. ⑵ The initiation of fatigue crack was occured at 28~32% through the total fatigue life. ⑶ The summarized relationship between crack propagation rate and stress intensity factor of structural steel (SM45C) is as follows. The value of exponent m was 1.41-1.85. ⑷ Propagating crack in fatigue generally passed along grain boundaries and ferrite matrix, it passed around and branched cause of hard inclusion. ⑸ In the case of higher stress amplitude the shpae of crack propagation and fracture surface was intricate.

자가 면역성 간염에서 자가항체의 발현 양상과 스테로이드 치료의 효과

박기오,채경훈,허원석,강윤세,정재훈,김연수,문희석,이엄석,김선문,이병석,김남재,이헌영 충남대학교 의과대학 의학연구소 2003 충남의대잡지 Vol.30 No.1

목적 : 최근 8년간 본원에서 경험한 자기면역성 간염의 혈액학적 특징과 스테로이드의 치료효과를 알아보고자 본 연구를 시행하였다. 방법 : 1996년 이후부터 2002년까지 충남대학교 병원에서 1999년 International Autoimmune Hepatitis Group(LAHG)에서 제시한 수정 진단 기준안에 의거하여 총 진단점수가 probable 이상에 해당하는 환자들을 대상으로 임상적 특징, 검사실 및 조직 소견과 스테로이드와 azathioprine의 치료 효과를 후향적으로 조사하였다. 결과 : 9예의 환자들은 여성이 78%, 40대가 많았고, 급성 발병이 33.3%, 피로감, 식욕부진 및 황달 등이 나타났으며, 항핵항체가 55.6%에서 그리고 항평활근 항체가 77.8%에서 양성이었고, 동반 질환은 류마치스 관절염이 2예, 특발성 혈소판 감소증 1예, Henoch-Sch nlein 자반증 및 그레브스병이 각각 1예 씩이었다. 7예에 대해서 스테로이드와 azathioprine으로 치료하여 생화학적 임상적 완해가 이루어져서 유효한 치료 결과를 얻었다. 결론 : 자가면역성 간염은 우리 나라에서 원인을 찾을 수 없는 만성 간질환의 경우, 특히 중년여성에서 다른 자가면역성 질환이 동반되었을 때 자가면역성 간염을 의심하여 자가항체 선별검사를 시행해 보아야 할 것으로 생각된다. 향후 다기관 연구를 통하여 좀 더 많은 증례를 모으고 전향적인 연구를 시행하여야 할 필요가 있다. Although autoimmune hepatitis(AIH) is common in western contries, some studties have been reported in Korea. The aim of the study was to analyze the clinical and histological features and expression pattern of the autoantibody and to examine clinical course of AIH in Korea. For 9 patients diagnosed as having AIH in our hospital since 1996, we reviewed medical records and analyzed clinical and laboratory findings retrospectively. They had a probable or definite AIH according to the revised criteria of International AIH group. The mean age was 42.7(21∼68)years and 7(77.8%) were female. Three of them(33.3%) showed acute hepatitis and five of them showed cirrhosis. Fatigue and anorexia were the most frequently complained symptoms(55.6%). Four patients(44.4%) were accompanied with other autoimmune diseases. Antinuclear antibody was detected in 5(55.6%) and anti-smooth muscle antibody was detected in 7(77.8%). Three patients showed focal picemeal necrosis and four showed periportal fibrosis. Among 7 patients who received immunosuppressive therapy, six patients(85.7%) showed initial response. and biochemical and serologic remission were achived in 5(71.4%) and 3(42.8%) patients, AIH seems to be partly responsible for chronic liver disease of unknown etiology in Korea. AIH should be suspected in female patients with unknown chronic liver disease of unknown etiolgy, especially accompanied with other autoimmune disease. The clinical characteristics of AIH may not be quite different from those of Western countries.

Gilbert 증후군에서 열량 제한 시험과 Phenobarbital 자극 시험의 의의(14예)

이헌영,채경훈,정재훈,강윤세,김연수,문희석,박기오,이엄석,김선문,김석현,성재규,이병석,이강욱 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Gilbert 증후군은 인구의 7%에서까지 나타날 수 있는 매우 흔한 증후군으로서 비진행성인 양성의 만성적 경과를 치하며, 간질환의 증상과 징후가 없는 경한 비포합형 고빌리루빈혈증이 특징인 일종의 체질적인 증상으로서 혈장 빌리루빈 농도에 대한 사춘기의 영향 때문에 10대와 20대에 자주 진단이 된다. 따라서 임상적인 중요성은 미약하지만 높은 빈도가 예상되는 점에 그 중요성이 부여되어야 할 것이다. 따라서 적정한 임상적 진단법으로 기왕에 소개된 열량제한 시험과 phenobarbital 유도 시험을 시행하고 이들의 진단적 가치를 알아보기 위하여 본 연구를 시행하였다. 1990년 7월부터 1999년 4월까지 충남대학교병원에 내원하여 HBsAg, IgG anti-HBc 및 anti-HCV가 음성이고, 간 초음파 스캔에서 이상이 없으며, 혈청 AST, ALT 및 AP가 정상인 비음주자에서 경한 비포합형 고빌리루빈혈증이 있는 14예의 환자들을 대상으로 ^(99m)Tc-DISID 스캔을 시행하였으며, 기저 치 총빌리루빈 및 포합형 빌리루빈 치를 측정한 다음에 하루에 400Kcal로 48시간동안 제한한 열량 제한 시험을 시행하였고, phenobarbital을 하루 60mg씩 5일간 투여한 후에도 각각 총빌리루빈과 포합형 빌리루빈 치를 검사하여 비포합형을 구하였다. 대상 환자들은 모두 14예로서 남자가 11예(78.6%)였고 여자가 3예(21.4%)여서 3.7:1로 남자에서 많았으며, 20대가 6예(42.9%), 30대가 역시 6예(42.9%) 및 40대가 2예(14.2%)로서 2,30대가 대부분(85.8%)이었다. 열량 제한 시험 후의 총빌리루빈 치, 비포합형 및 포합형 빌리루빈 치들은 평균 각각 5.5±2.7, 4.2±2.3 및 1.3±10mg/dL 로서, 시험 전 치들인 3.0±0.8, 2.2±0.8 및 0.7±0.4mg/dL 보다 유의하게(p=0.001, p=0.001, p=0.023) 상승하였다. 포합형 빌리루빈 치도 유의하게 상승하였으나 비포합형의 상승보다는 훨씬 낮아서 주로 비포합형이 증가하였다. phenobarbital 투여 중 설사가 발생하여 중단한 1예를 제외한 13예에서 열량 제한 시험 후에 상승하였던 총, 비포합형 및 포합형 빌리루빈 치가 phenobarbital 유도 시험후에는 2.0±1.1, 1.5±0.8 및 0.5±0.4mg/dL로서 열량 제한 시험 결과보다 유의하게 낮아졌고(p=0.00, p=0.000, p=0.001), 열량 제한 시험 전의 기초치들인 3.0±0.8, 2.2±0.8 및 0.7±0.4mg.dL 보다도 더욱 낮아졌으며 유의한 차이(p=0.001, p=0.02, p=0.005)를 나타내었다. 14예에서 시행한 ^(99m)-Tc DISIDA 스캔에서 9예(64.3%)가 정상이었고, 5예(35.7%)에서는 심장 및 신장으로의 간외 섭취가 3예였고, 60분까지 소장 배출이 없는 배설 지연 예와 담낭 수축 불량 예가 각각 1예 씩 발견되었다. Phenobarbital 투여시험에서 민감도가 열량제한시험에 비해 더 높았다(92.3%와 50.0%). Gilbert 증후군에서 1일 400 Kcal로 48시간의 열량제한 시험과 1일 60mg의 phenobarbital을 5일간 투여하는 유도 시험은 편리하고 유용한 임상적인 진단법으로 이용할 수 있다고 생각된다. 그러나 열량 제한 시험에서는 증가 기준의 통일이 필요하다고 유추되며 phenobarbital 유도 시험이 민감도가 더 높은 것으로 생각된다. Gilbert's syndrome is very frequent and benign chronic process characterized by mild, intermittent, unconjugated hyperbilirubinemia without any symptom and sign of liver disease. Previously intoduced caloric restriction test and phenobarbital stimulation test as two appropriate clinical tests had been examined and their diagnostic values were reevaluated. Fourteen patients with mild, persistent, unconjugated hyperbilirubinemia were included. Subsequently caloric restriction has been applicated by 400 Kcal/day for 48 hours and phenobarbital has been prescribed by 60 mg/day for 5 days. Therafter serum levels of total and direct bilirubin were measured. Most of the patients were third and fourth decade(85.8%) and male predominant. Each basal serum levels of total, indirect and direct bilirubin were 3.0±0.8, 2.2±0.8 and 0.7±0.4 mg/dL. After caloric restriction test, each levels were increased significantly to 5.5±2.7, 4.2±2.3 and 1.3±1.0 mg/dL(p=0.001, p=0.001, p=0.023). After phenobarbital stimulation test for 13 patients had been practiced, increased levels of each bilirubin after caloric restriction test were decreased significantly to 2.0±1.0, 1.5±0.8 and 0.5±0.4 mg/dL(p=0.000, p=0.000, p=0.001) and these levels were significantly lower than basal levels(p=0.001, p=0.02, p=0.005). The sensitivities of caloric restriction test were 85.7%, 50.0%, and 71.4%, 35.7%(1.0, 1.5 mg increase of total bilirubin and 1.0, 1.5 mg/dL increase of indirect bilirubin). The sensitivities of phenobarbital stimulation test were 93.2% and 92.3% at criteria of 1.5 mg/dL increase of total bilirubin and indirect bilirubin. On the diagnosis of Gilbert syndrome, caloric restriction test and phenobarbital stimulation test are convenient and useful diagnostic tools in clinical face. And also phenobarbital stimulation test has higher sensitivity than caloric restriction test. Furthermore, standardization of bilirubin increment would be necessary in caloric restriction test.

간세포암과 감별이 어려웠던 악성중피종 치험 1예

김선문,허원석,채경훈,강윤세,정재훈,김연수,박기오,문희석,이엄석,김석현,성재규,이병석,이헌영,신경숙,조준식,송인상,강대영 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Malignant peritoneal mesothelioma is a rare neoplasm that arises from the mesothelium of a serosal cavity and is a rapidly fatal disease with a median survival of 4 to 12 months for untreated cases. Recently, we experienced a case with malignant peritoneal mesothelioma who was suspected hepatocelluar carcioma by abdominal CT scan and was confirmed by biopsy including immunohistochemical stain(calretinin) after surgery. We performed tumor excisions and wedge resection of the liver(segment Ⅷ)and inserted Tencoff catheter in abdominal cavity at 25th day of post-operation. We treated with intraperitoneal paclitaxel(25mg/m^(2)/day for 5 days) six courses monthly. She was well tolerable and is still living without any evidence of recurrence for 14th month of post-operation.

공기 중 SO2에 의한 고분자전해질 연료전지의 성능 감소

김기중 ( Ki Joong Kim ),임태원 ( Tae Won Lim ),이호 ( Ho Lee ),박권필 ( Kwon Pil Park ),김세훈 ( Sae Hoon Kim ),안병기 ( Byung Ki Ahn ),송진훈 ( Jin Hoon Song ) 한국화학공학회 2010 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.48 No.3

이온 오염에 의한 고분자전해질 연료전지의 성능저하

송진훈 ( Jin Hoon Song ),우명우 ( Myung Wu Woo ),( Ki Joong Kim ),김세훈 ( Sae Hoon Kim ),인병기 ( Byung Ki Ahn ),임태원 ( Tae Won Lim ),박권필 ( Kwon Pil Park ) 한국화학공학회 2012 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.50 No.2

Contamination of ion from cathode air on the membrane and electrode assembly (MEA) is the serious degradation source in proton exchange membrane fuel cells (PEMFC). In this study, concentration of ions in air at industry region, street and seaside were measured, There were comparably high concentration of Na+, K+, Ca2+ and Fe3+ in this regions, This paper shows the effects of MEA contamination by these ions generated from humidification water. After 170 hours of fuel cell operation using city water as humidification water, the performance of unit cell decrease to 11% of initial performance. The electrolyte membrane easily absorbed foreign contaminant cations due to the stronger affinity of foreign cations with the sulfonic acid group compared to H+. The contaminant ions existing in the interface between the platinum catalyst and ionomer layer turn out to be the most serious factor to decrease cell performance.

Effects of Seaweeds as Carbon Sources for the Growth of Lactic Acid Bacteria from Flounder Fish

Ki-Wan Lee(이기완),You-Jin Jeon(전유진),Moon-Soo Heo(허문수),Choon Bok Song(송춘복),Sae-Hoon Kang(강세훈) 한국해양환경·에너지학회 2002 한국해양환경공학회 학술대회논문집 Vol.2002 No.-

Application of brass scrubber filter with copper hydroxide nanocomposite structure for phosphate removal

Ki Ho Hong,In Sang Yoo,Sae Hoon Kim,Duk Chang,Young Sunwoo,Dae Gun Kim 대한환경공학회 2015 Environmental Engineering Research Vol.20 No.2

In this study, a novel phosphorus removal filter made of brass scrubber with higher porosity of over 96% was fabricated and evaluated. The brass scrubber was surface-modified to form copper hydroxide on the surface of the brass, which could be a phosphate removal filter for advanced wastewater treatment because the phosphates could be removed by the ion exchange with hydroxyl ions of copper hydroxide. The evaluation of phosphate removal was performed under the conditions of the batch type in wastewater and continuous type through filters. Filter recycling was also evaluated with retreatment of the surface modification process. The phosphate was rapidly removed within a very shorter contact time by the surface-modified brass scrubber filter, and the phosphate mass of 1.57 mg was removed per gram of the filter. The possibility of this surface-modified brass scrubber filter for phosphorus removal was shown without undesirable sludge production of existing chemical phosphorus removal techniques, and we feel that it would be very meaningful as a new wastewater treatment.

구인두 연하곤란을 동반한 다발성근염

김기훈 ( Ki Hoon Kim ),서검석 ( Geom Seg Seo ),김태현 ( Tae Hyeon Kim ),김용성 ( Yong Sung Kim ),최창수 ( Chang Soo Choi ),이명수 ( Myeung Su Lee ),오효정 ( Hyo Jung Oh ),서승오 ( Sung O Seo ),신새론 ( Sae Ron Shin ),최석채 ( Suck 대한소화기기능성질환·운동학회 2007 Journal of Neurogastroenterology and Motility (JNM Vol.13 No.2

The oropharyngeal dysphagia results from variable etiologies such as neuropathies, drugs, myopathies, structural disorders of esophagus. Polymyositis is rare and 12~54% of the patients develop dysphagia. Many patients with oropharyngeal dysphagia are complicated by asphyxia, aspiration during swallowing, severe pneumonia or death. Early diagnosis and proper management is important for the prevention of complication. The patients with oropharyngeal dysphagia can be diagnosed by the investigations such as barium contrast swallowing test, videofluoroscopy, esophagoscopy, esophageal manometry. We report a case of polymyositis with oropharyngeal dysphagia that diagnosed by clinical symptoms, EMG finding and elevated muscle enzyme treated with high dose prednisolone. (Kor J Neuro-gastroenterol Motil 2007;13:152-155)

결장 및 직장암의 예후 인자로서 DNA 지수의 의의성

정기훈(Ki Hoon Jung),이은숙(Eun Sook Lee),백정원(Jeoung Won Bae),서성옥(Sung Ok Suh),문홍영(Hong Young Moon),김세민(Sae Min Kim) 대한외과학회 1996 Annals of Surgical Treatment and Research Vol.50 No.6