Streptozotocin유도 당뇨병이 백서하악 절단과두 치유에 미치는 영향의 실험적 연구

황의환,이상래,홍정표,김원철 大韓口腔顎顔面 放射線學會 1994 Imaging Science in Dentistry Vol.24 No.2

The purpose of this study was to investigate the remodeling process of the streptozotocin-induced diabetic rat's resected condyle. This experiment was performed with male Sprague-Dawly strain rats weighing approximately 250gm, which were rendered diabetic by an intravenous injection of streptozotocin(70 ㎎/㎏ body weight). After condylectomy, experimental rats were serially terminated on the 1st week, the 2nd week, the 3rd week, and the 4th week. The following termination, the mandibles were dissected out to make specimens. Each mandibular condyle was radiographed with Hitex HA-80(Hitex Co., Ltd. Japan). In addition to radiographic observation, the mandibular condyles, further decalcified and embedded in paraffin, were sectioned and stained with Hematoxylin and Eosin, Toluidine blue and Masson's trichrome. The were observed with a light microscope and a polarizing microscope. The results were as follows. 1.Soft X-ray radiograms revealed proliferation of bone after 1 week in both groups. Irregularly repaired bones and dense trabeculae were clearly observed in experimental group. 2.The resected condyles were repaired by intramembraneous and endochondral bone formation in both groups. 3.Bone tissue repair was initiated from the adjacent margin of resected bone, and cartilginous tissues were observed at the top of repaired one in both groups. 4.The number of osteoblasts of experimental group was small, compared with control group. Each osteoblast was small and flap. The thin trabeculae were irregularly formed. 5.Collagens of bone were gradually matured in both groups, but the degree of maturation was lower in experimental group. 6.Fibrous tissues covered the upper parts of repaired bone were densely arranged in the both groups. Conclusively, atrophied osteoblasts, immature collagen of bone, and this and irregular trabeculae which were characterized in the diabetes experimental group showed diabetes disturbed osteoblastic function and caused disturbance of remodeling process of bone.

저주파수 및 저입력전압용 박막형 다중접합 열전변환기

황찬순,이형주,김진섭,이정희,박세일,권성원 한국센서학회 2002 센서학회지 Vol.11 No.3

저주파수의 저전압용 크로멜-알루멜 다중접합 열전변환기를 개발하고자 NiCr 히터의 두께를400 nm, 600 nm 및 800 nm로 변화시켰다. 40 Hz∼10 kHz의 직류 역방향 주파수 범위로 0.5 V의 교류 실효전압을 열전변환기에 인가시켰을 때 히터의 두께가 400 nm인 열전변환기가 ±0.51∼±1.69 ppm 범위의 열전효과에 의한 교류-직류 전압 변환오차를 나타내었고, 열전효과 및 주파수에 의한 교류-직류 변환오차는 40 Hz∼l MHz의 주파수 범위에서 ±40∼±115 ppm 범위를 나타내어, 저주파수의 저전압용으로 사용할 수 있었다. NiCr-heaters with three different thicknesses ranging from 400 nm to 800 nm were fabricated and their characteristics were compared for the purpose of developing a chromel-alumel multijunction thermal converter for low input voltage with low frequency. The thermoelectric effect-induced AC-DC voltage transfer difference of the thermal converter with a built-in NiCr-heater of 400 nm-thickness was ±0.51∼±1.69 ppm in the DC reversing frequency of 40 Hz∼10 kHz with appling 0.5 V_rms and the difference was increased to ±40∼±115 ppm in the frequency of 40 Hz~l MHz, when both thermoelectric effects and frequency effects were considered, showing the thermal converter would be suitable for the low input voltage application with low frequency.

실험적 간암 발생 과정에 출현하는 난원형 세포의 면역 조직화학적 연구

황택근,이중달,원치규 한양대학교 의과대학 1992 한양의대 학술지 Vol.12 No.1

Oval cells have been observed during chemical carcinogenesis in the livers of animals fed 2-acetylaminofluorene (2-AAF), a potent chemical carcinogen. Biological behavior of these cells remained poorly understood with regard to gepatic carcinogenesis. The author carried out the histological, enzyme histochemical and immunohistochemical studies of oval cells in the livers from 80 rats fed 2-AAF for five months. Throughout the experimental period oval cells along with hepatocytes and bile ductular cells were subjected to immunostain for monoclonal antibodies. The antibodies included those to carcinoembryonic antigen(CEA), alpha-fetoprotein(AFP), low molecular cytokeratin(CAM 5.2), prealbumin, and endothelial cells. Alkaline phosplatase(ALP) reaction to oval cells was also evaluated. The followings were results obtained: Oval cells appeared about the portal areas at the 10th day of the experiment. The cells penetrated the hepatic lobule as they proliferated. The proliferation of oval cells was most prominent at the 6th week and then the cells were gradually decreased in number until the late stage of the experiment. There were foci of transformation of oval cells to cholangiolar cells and foci of cholangiofibrosis made up of proliferated bile ductules. PAS reaction was negative on oval cells, where as hepatocytes were reactive for PAS. ALP reaction was positive on both oval cells and ductular epithelial cells. The hepatocytes were non-reactive for ALP. Both oval cells and bile ductular cells showed positive staining for AFP and CAM 5.2, and negative for CEA and prealbumin. Hepatocytes showed negative staining for AFP, CAM 5.2, CEA and prealbumin. However, an impressive finding that AFP- and CAM-positive hepatocytes were scattered through the hepatic lobules, was observed early during hepatocarcinogenesis. The results indicated that oval cells had no evidence of the conversion to hepatocytes in 2-AAF induced hepatocarcinogenesis, and that hepatocellular carcinoma arose not from oval cells. Oval cells showed immonohistochemical characteristics similar to those of the bile ductular epithelium.

말초혈액 내 백혈구수와 대사증후군과의 연관성

황상태,김범수,황상준,서정열,김병진,이원영,성기철,강진호,김선우,이만호,박정로 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.3

유기산의 해리평형에 미치는 치환기 효과와 그의 온도 및 압력의 영향. : (2) 수용액중에서 몇가지 치환나프톨류의 해리상수 (2) Dissociation Constants of Some Substituted Naphthols in Aqueous Solution

黃正儀,裵俊雄,鄭倧在,鄭在元,張景喜 慶北大學校 物理化學硏究所 1986 硏究論文集 Vol.7 No.-

치환나프톨류(4-Cl-1-Naphthol, 6-Br-2-Naphthol, 8-NH_2-2-Naphthol)의 해리상수를 온도(25∼40℃)와 압력(1∼2000 bar)을 변화시키면서 분광학적 방법으로 측정했다. 이들의 해리상수는 치환기가 들어가므로서 모두 감소했다. 이것은 치환기의 I-효과로서 설명이 가능했으며 또 온도와 압력이 증가하면 해리상수도 증가하였다. 이들 해리상수로부터 반응의 열역학적 성질을 계산하여 반응의 성질을 알아보았다. The dissociation constants of 4-Cl-1-naphthol, 6-Br-2-naphthol, 8-NH_2-2-naphthol in aqueous solution were measured by spectroscopic method in the temperature range from 25 to 40℃ and pressure up to 2000bar. The dissociation constants were decreased as the substituents were inserted in naphthol from 4.4×10 exp(-10) to 5.82×10 exp(-11) as chloride compound and 2.5×10 exp(-10) to 3.44×10 exp(-11) or 4.21×10 exp(-11) as bromine or amino compounds, respectively. This decrease can be explained with the I- or R-effects of substituents. From the dissociation constants various thermodynamic properties were claculated and discussed the characteristics of the dissociation reaction.

흉골 골절의 의의에 관한 임상적 연구

원형섭,황성연,박정배,이준형,박철완,이근 대한응급의학회 1996 대한응급의학회지 Vol.7 No.2

It has been known that sternal fracture increases the risk of potentially life-threatening injuries, such as myocardial, pulmonary, and thoracic vascular injuries, and it has 25% to 45% of mortality, primarily resulting from these underlying injuries. The authors reviewed retrospectively the medical records and radiographic findings of the patients who admitted with sternal fracture at Chung Ang Gil Hospital from 1 June 1994 to 31 December 1995 to evaluate the significance and clinical course of sternal fracture. The results were followings: 1. The male to female ratio was 3:2 and the mean age was 43.1 and 45.4 years old in male and female, respectively. 2. Motor vehicle occupant accident was the most common cause of sternal fracture. 3. Of 33 cases, there was no death, but common associated injuries which were rib fracture, hemothorax, lung contusion, vertebral fracture, penumothorax, long bone fracture, myocardial contusion, flail chest, facial chest, facial bone fracture, and pericardial effusion, in order. 4. The clinical course of sternal fracture was determined primarily by associated injuries except for communited sternal fracture. 5. The patients with isolated sternal fracture, who had an otherwise normal chest x-ray, normal electrocardiogram, no other significant associated injuries and are hemodynamically stable, had a benign clinical course.

Corrigendum to “Vertebral Body Anterior Translation, a Novel Technique for Delayed Myelopathy Due to Osteoporotic Spine Fractures”

Jung Soo Lee,Dong Ki Ahn,Won Shick Shin,Kyung Jun Cho,Young Rok Ko,Il Chan Hwang 대한정형외과학회 2022 Clinics in Orthopedic Surgery Vol.14 No.4

Clinics in Orthopedic Surgery 2020;12:485-492 https://doi.org/10.4055/cios20028 In the article entitled “Vertebral body anterior translation, a novel technique for delayed myelopathy due to osteoporotic spine fractures,”1) the name of one of the authors was incorrectly presented: Il Chan Whang should read Il Chan Hwang.

고속가공을 위한 검사시편에 관한 연구

정종윤,황영수,이춘만,정원지,고태조 한국공작기계학회 2003 한국생산제조학회지 Vol.12 No.4

The properties of a machine tool greatly affect machining quality since a machine tool has large variance in its features. Machine tool makers want to find best machining condition with the one that they have built. Machine builders need to develop test specimen since it helps finding characteristics of machine tools when the machining properties of the specimen are analyzed. This paper develops test specimen to identify features of the main spindle, the feeding device, and the frame of a machine tool. The specimen is machined with a high speed machine and the features of the machine are analyzed with test items. They are surface roughness, overshoot in axial movement, errors in circular movement, feeding with small movement, and compensational error. This work can improve usability for a machine tool in machining practice.

Wafer final polishing에 따른 표면 현상과 마멸도에 관한 연구

원종구,이정택,황성철,차지완,이은상 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

In recent years, developments in the semiconductor and electronic industries have brought a rapid increase in the use of silicon wafer. For further improvement of the ultra precision surface and flatness of Si wafer necessary to high density ULSI, it is known that final polishing is very important. Polishing one of the important methods in manufacturing of Si wafers and in thinning of completed device wafers. This study will report the evaluation on abrasion of wafer according to variety processing condition, which have major influence on the abrasion and surface defect of Si wafer polishing, were adapted to polishing pressure, machining speed, and the slurry mix ratio. Thus the optimum condition selection of ultra precision Si wafer polishing using load cell and infrared temperature sensor. To evaluate each machining factor, use a data through each sensor. That evaluation of abrasion according to variety condition is selected to use a result data that measure a pressure, machining speed, and the processing time. And optimum condition is selected by this result. By using optimum condition, it achieve a ultra precision mirror like surface.

코스틱스법에 의한 순수 전단장치 평가에 관한 연구

황재석,김원현,서정희 嶺南大學校 工業技術硏究所 1998 工業技術硏究所論文集 Vol.26 No.1

There are many experimental devices for pure shear test such as off-axis tension test pure shear test for Iosipescu conceptions. Arcan circular disk for Arcan conceptions and the general pure shear test and Hawong Iosipescu shear test(H.I.S.T.) etc.. Hawong Iosipescu shear test(H.I.S.T.) device is analyzed through caustics. It is assured that H.I.S.T. device is more effective than Iosipescu shear test(I.S.T.) device for the measurement of stress intensity factor from causic. It is known that H.I.S.T. device without notch is most effective as pure shear test device, between H.I.S.T. device and I.S.T. device for caustics, but H.I.S.T .device and I.S.T. devices are can be used ad pure shear test device