實用性을 指向한 大學敎養英語敎育의 改善

蔡俊基,朴英壽,金基璨 慶北大學校 語學硏究所 1983 語文硏究 Vol.8 No.-

퍼지 신경망을 이용한 압전구동기 변위의 비선형성제어

채재희,문찬영,김인수 金烏工科大學校 2000 論文集 Vol.21 No.-

Piezoelectric actuator is a promising actuator to be expected to play a key role in the mechatronics. However it has a nonlinear characteristics due to hysteresis between input voltage and displacement. This paper proposes a method to model and linearize the nonlinear characteristics of piezoelectric actuator using fuzzy-neural network and feedforward control. Experimental result describes that nonlinearity may be reduced 70 percentage by the proposed method.

담체의 표면거칠기와 전단응력이 미생물 부착에 미치는 영향

박영식,송승구,이채남,최윤찬 부산대학교 환경문제연구소 1995 環境硏究報 Vol.13 No.-

The propose of this paper was to examine the effect of surface roughness and shear stress of support medium on the development of biofilm in a rotating biological contactor. The surface roughness of PMMA as a support media was adjusted to 0.4, 0.8, 1.2, and 3㎛, respectively. Shear stress was varied with speed of rotating biological contactor. At low shear stress, bacterial attachment was not varied greatly with surface roughness. But at increased shear stress, bacterial attachment was changed sharply with surface roughness.

냉간가공한 각형강관 단주의 압축거동

유영찬,임재형,채영석 국립7개대학공동논문집간행위원회 2002 공업기술연구 Vol.2 No.-

Square steel tubular columns are widely used in high-rise buildings, where high bending and torsional load carrying capacity are required. The objective of this study is to investigate the structural behavior of stub columns with cold formed square steel tube. Buckling behavior of axially compressed stub columns with the cold formed square steel tube was studied experimentally. The experiments on the 26 specimens with the parameters such as width-thickness ratio were conducted under the axially concentric compression. In the experiment, square steel tubes were axially compressed slowly until they were completely collapsed. The measured results were presented and the local buckling strength of stub columns with cold formed square steel tube was evaluated by regression.

국산 백굴채 엑스의 급성 경구독성과 항암작용에 관한 연구

김정훈,김영옥,박찬봉,채병숙,강태욱,안영근 원광대학교 식품약품안전성연구소 1995 食品藥品安全性硏究 Vol.8 No.-

The MeOH and H_2O extracts of Chelidoni Herba were examined for acute oral toxicity in mice, and MeOH extract of Chelidoni Herba was examined for anti inflammatroy activities in rats. The results of this study were summarized as follows: (1) The median lethal doses of the total MeOH and H_2O extracts of Chelidoni Herba were 12.5 and 10.1 g/㎏. respectively. (2) Major symptoms of this acute oral toxicity were eye extrusion. hair erection. trembling of head. paralysis. rapid running or moving before death, and depression of respiration. (3) The total MeOH extract of Chelidoni Herba was shown to have significant anti-inflammatory activity on toe paw edema induced by carrageenin.

Hg₁-xMnxTe산화막의 홀효과에 관한 연구

오재근,최기영,송재흥,김영국,채건식,주유환,설정식,손인호,차성극,이상찬 慶南大學校 附設 基礎科學硏究所 1996 硏究論文集 Vol.8 No.-

HClO₄(pH:2) 수용액에서 양극산화 방법으로 HgMnTe(HMT)의 표면에 산화막을 형성 시켰다. 산화막의 두께는 SEM으로 측정하였으며 10㎛였다. 전류-전압 특성곡선을 얻어 산화 피크 전압으로부터 HTeO₂?, TeO?, HHgO₂? 막이 형성되었음을 알 수 있었다. 산화시키지 않은 HMT와 HClO₄수용액에서 산화시킨 HMT에 대해 Hall전압 및 자기저항을 각각 측정하였다. 홀전압과 자기저항은 HMT보다 HMT산화막에서 더 컸으며 이것은 HHgO₂? 공격자가 홀의 역할을 하고, TeO₄? 산화막은 전하의 포획도를 낮게하기 때문으로 생각할 수 있다. Anodic oxidation processes on HgMnTe surface has been studied in standard aqueous HClO₄(pH:2) solution. The 10㎛ thickness of the anodic oxide layers was measured by SEM. The Composition of the anodic oxide layers are evaluated from current-voltage(I-V) characteristic of HgMnTe Oxidation. The layers are composed of mixed oxide. ??, TeO₄, and?? in HClO₄solution. Transport properties have been investigated in HMT oxide layer made in HClO₄solution and virgin HMT samples at 300K. Hall voltage and magnetoresistance are greater in oxide layer HMT than virgin HMT. As a result, we know that the vacancy of ??in an anodic oxide layer acts as hole and the resulting oxide ?? layer exhibit a reduced degree of charge trapping and increase magnetoresistance.

말초혈액에서 Tg mRNA에 대한 역전사 중합효소 연쇄 반응법의 갑상선 재발암의 분자생물학적 진단

권성일,박기룡,김현영,신채희,임영찬,최영식,박요한,이강대,장희경,이재화,염하용 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.4

연구배경: 갑상선암은 다른 조직에 발생한 암에 비해 비교적 천천히 자라므로 대부분 예후가 양호하지만, 일부에서는 주위 조직으로 침윤하거나 혹은 원격 전이로 인하여 치명적인 결과를 초래할 수 있다. 갑상선전절제술 및 131^I 제거술 후 경과 관찰시 갑상선암의 재발과 전이의 진단에 있어 131^I 스캔과 혈청 Tg의 측정이 현재 임상에서 가장 많이 이용되고 있으나 이 방법에는 여러 가지의 결점이 있다. 최근 Tg mRNA에 대한 RT-PCR법을 이용한 여러 연구결과는 131^I 스캔과 혈청 Tg 측정의 결점을 보완할 수 있는 좋은 보조적인 진단법으로 이용할 수 있을 가능성을 제시하였다. 이에 말초혈액에서 측정한 Tg mRNA에 대한 RT-PCR법이 갑상선 절제술 및 방사성요드 치료 후 갑상선암의 재발 및 전이 유무의 진단에 유용한가를 알아보고자 이 연구 시행하였다. 방법: 분화된 갑상선암으로 진단된 후 갑상선전절제술을 시행받고 방사성요드 치료를 받은 환자 중 현재까지 한차례에 이상 추적 방사성요드 전신 스캔을 시행하고 추적관찰이 가능했던 유두선암 35예, 여포선암 5예를 대상으로 연구를 시행하였다. 대상군은 131^I 스캔 소견상 음성인 군(Group Ⅰ), 잔여조직이 있는 군(Group Ⅱ), 국소전이가 있는 군(Group Ⅲ), 및 원격전이 군(Group Ⅳ)으로 구분하였다. 정상 대조군은 갑상선질환이 없는 10예의 건강인으로 하였다. 대상환자의 말초혈액을 이용한 Tg mRNA에 대해 특이적인 primer를 이용하여 RT-PCR 및 nested RT-PCR을 시행하였다. 결과: 본 연구 결과는 다음과 같다. 1) 131^I 스캔 소견상 음성인 군 21예 중 1예에서 Tg가 양성소견을 보였다. Anti Tg Ab가 양성인 4예 모두 Tg가 음성을 보였다. 잔여조직이 있거나 국소전이 및 원격전이를 보인 군 19예 중 Tg가 양성인 경우는 4예였으나, Tg mRNA는 전예에서 양성이었다. 2) 131^I 스캔에서 국소 및 원격전이 소견을 보인 8예 중 4예에서 Tg가 음성으로 131^I 스캔과 혈청 Tg 사이에 불일치 소견을 보였다. 3) 말초혈액에서 특이적인 primer를 이용하여 RT-PCR 및 nested RT-PCR을 시행한 결과 대상군 40예 및 정상 대조군 10예 모두에서 Tg mRNA가 양성을 보였다. 결론: 본 연구에서 갑상선 절제술 및 방사성요드 치료 후 갑상선암의 재발 및 전이 유무를 평가함에 있어 역전사 중합효소 연쇄 반응법을 이용한 Tg mRNA 측정의 의의는 재평가되어야 한다고 생각된다. Background: Differentiated thyroid cancer is the most common endocrine malignancy. Despite advances in the treatment of thyroid cancer, disease recurrence and metastasis may occur in as many as 20% of patients, and so continues to pose major problems in its clinical management. Serum thyroglobulin (Tg) measurements, by immunoassay, are used to detect residual or recurrent thyroid cancer following thyriod ablation. However, the usefulness of immunoassay is limited by both the requirement for thyroid hormone withdrawal, to attain optimal test sensitivity, and interference by the antithyroglobulin antibody (Anti-Tg Ab). Recent studies have reported the clinical usefulness of reverse transcription-polymerase chain reaction (RT-PCR) detection of Tg mRNA in the peripheral blood of patients with differentiated thyroid carcinomas. We performed this study to evaluated the usefulness RT-PCR of Tg mRNA in peripheral blood of patients with thyroid carcinoma following a total thyroidectomy and radioiodine ablation therapy. Methods: Forty cases that underwent a total thyroidectomy and radioiodine ablation therapy were included in this study. Of the 40 patients, 35 were papillary carcinomas and 5 were follicular carcinomas. Ten normal control subjects were also studied. Tg mRNA was extracted. Then RT-PCR and nested RT-PCR, were run with specific Tg primers. Concurrently, DNA sequencing of the isolates was carried out to prove the isolates were identical to the nucleotide sequence of the Tg. Results: The Tg was detected in 4 of 19 patients, with either a residual thyroid bed, or metastasis, on a 131^I whole body scan and in 1 of 21 patients with a negative radioiodine scan. Surprisingly, the Tg mRNA was detected in all the patients and normal controls. Conclusion: From our results we can not recommend Tg mRNA, detected by RT-PCR in peripheral blood, as a tumor marker superior to that of the Tg serum level. We consider an intensive re-evaluation of the method is required before considering its clinical applications (J Kor Soc Endocrinol 17:501∼513, 2002).

The Prevalence and Characterization of Cerebral Microbleeds in Young People Having Intracerebral Hemorrhage

Young-Min Lee,Hae-Won Koo,Hyung Koo Kang, M.D.,Jin Woo Kim,Seong Rok Han,윤상원,Chan Young Choi,손문준,Chae Heuck Lee 대한뇌혈관외과학회 2018 Journal of Cerebrovascular and Endovascular Neuros Vol.20 No.2

Objective : Cerebral microbleeds (CMBs) are known as the neuroimaging markers of risk in stroke and dementia. Many studies on CMBs in elderly patients with hemorrhagic or ischemic stroke have been reported; however, reports on CMBs in young populations with intracerebral hemorrhage (ICH) are lacking. Materials and Methods : A total of 272 patients aged 18-54 years presented to our hospital with ICH between December 2009 and August 2017. Among these, CMB presence, count, and topography with respect to ICH were evaluated on magnetic resonance imaging (MRI) gradient echo images (GREs). We also evaluated the prevalence and risk factors of CMBs. Results : Among 272 patients, only 66 underwent GRE T2-weighted MRI. CMBs were detected in 40 patients (61%), with 29 (73%) being of the multifocal type. Among the 219 CMBs, 150 (68.5%) were of the deep type and 69 (31.5%) of the lobar type. CMB prevalence was higher in men. In multivariate logistic regression analysis, history of hypertension (adjusted odds ratio [aOR], 4.048; 95% confidence interval [CI], 1.14-14.32; p = 0.030), and male sex (aOR, 4.233; 95% CI, 1.09-16.48; p = 0.037) were independently associated with CMBs. Conclusion : In young patients who presented with spontaneous ICH, CMBs were highly prevalent in 61% of patients and strongly associated with history of hypertension and male sex.

병사용 진단서 발급을 위해 복강경검사에서 간조직검사를 시행한 젊은 성인 남자의 간침생검 소견 : 새로운 만성간염병리분류를 기준으로 Histologic Grading and Staging of Chronic Hepatitis

전재윤,문영명,박영년,백용한,박찬일,한광협 대한소화기학회 2000 대한소화기학회지 Vol.36 No.2

Background/Aims: This study was designed to assess the etiology and characteristics of chronic liver disease among the young male adults. It was also investigated whether grades of activity and status of fibrosis defined by the new histopathologic classification system of chronic hepatitis are related with alanine aminotransferase (ALT) level and HBeAg status in HBsAg-positive case. Methods: Peritoneoscopic findings, clinical features and histopathologic features of liver were investigated for 140 young men who received liver biopsy for military medical certificate from January 1994 to December 1997. These features were evaluated according to the grade and stage of chronic hepatitis. Results: In Korea, hepatitis B virus was the main cause of chronic hepatitis (87.7%) in young male adults and the infection of hepatitis C virus was rare (1.4%). Among HBsAg-positive cases with normal ALT level, 82.2% of them revealed chronic liver disease, and 48.3% of them showed chronic active hepatitis/cirrhosis in biopsy specimens. The grade of chronic hepatitis showed weak correlation with ALT level and the stage did not. There was no significant difference in the grade and stage of chronic hepatitis according to the serum HBeAg status. Conclusions: The most common cause of chronic liver disease in Korean young male adults was hepatitis B virus, and most (92.6%) of HBsAg-positive cases were proved to have chronic liver diseases histologically, regardless of the serum ALT level. According to new histopathologic classification system of chronic hepatitis, serum ALT level correlated with necroinflammatory activity of chronic hepatitis B, but not with fibrosis in HBsAg-positive cases.

Exploratory Clinical Investigation of (4<i>S</i>)-4-(3-¹⁸F-Fluoropropyl)-<small>l</small>-Glutamate PET of Inflammatory and Infectious Lesions

Chae, Sun Young,Choi, Chang-Min,Shim, Tae Sun,Park, Yangsoon,Park, Chan-Sik,Lee, Hyo Sang,Lee, Sang Ju,Oh, Seung Jun,Kim, Seog-Young,Baek, Sora,Koglin, Norman,Stephens, Andrew W.,Dinkelborg, Ludger M. Society of Nuclear Medicine 2016 The Journal of nuclear medicine Vol.57 No.1

<P>We explored system x(C)(-) transporter activity and the detection of inflammatory or infectious lesions using (4S)4-(3-F-18-fluoropropyl)-L-glutamate (F-18-FSPG) PET. Methods: In 10 patients with various inflammatory or infectious diseases, as many as 5 of the largest lesions were selected as reference lesions. F-18-FSPG images were assessed visually and quantitatively. Expression levels of xCT, CD44, and surface markers of inflammatory cells were evaluated by immunohistochemistry. Results: F-18-FSPG PET detected all reference lesions. F-18-FSPG uptake in sarcoidosis was significantly higher than that in nonsarcoidosis. The lesion-to-blood-pool SUV ratio for F-18-FSPG was comparable to that for F-18-FDG in sarcoidosis. In nonsarcoidosis, however, it was significantly lower. In 5 patients with available tissue samples, the SUVmax for F-18-FSPG and CD163 were negatively correlated (p = -0.872, P = 0.054). Conclusion: F-18-FSPG PET may detect inflammatory lesions when activated macrophages or monocytes are present, such as in sarcoidosis.</P>