Corrosion Behavior of Inconel X-750 for Carbon Anode Oxide Reduction Application

Jeon, Min Ku,Kim, Sung-Wook,Lee, Sang-Kwon,Choi, Eun-Young Korean Radioactive Waste Society 2020 방사성폐기물학회지 Vol.18 No.3

The corrosion behavior of the Inconel X-750 alloy was investigated for its potential application under a Cl₂-O₂ mixed gas flow in an Ar atmosphere. The corrosion rate was found to be negligible at temperatures up to 400℃ under a flow rate of 30 mL·min^-1 Cl₂ + 170 mL·min^-1 Ar, whereas an exponential increase was observed in the corrosion rate at temperatures greater than 500℃. The suppression of the corrosion reaction due to the presence of O₂ was verified experimentally at flow rates of 30 mL·min^-1 Cl₂ (4.96 g·m^-2·h^-1), 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂ (2.02 g·m^-2 ·h^-1), and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂ (1.34 g·m^-2·h^-1) under a constant Ar flow rate of 170 mL·min^-1 at 600℃ for 8 h. The surface morphology analysis results revealed that porous surfaces with tunnel-type holes were produced under the Cl₂-O₂ mixed-gas condition. Furthermore, the effects of the Cl₂ flow rate on the corrosion rate were investigated, indicating that its impact was negligible within the range of 5-30 mL·min^-1 Cl₂ at 600℃.

C -11 및 F - 18 표지 콜린의 합성과 체내동태에 관한 연구

전권수,유국현,김상욱,임상무,홍성운,서용섭,양승대,안순혁,허민구 대한핵의학회 2001 핵의학 분자영상 Vol.35 No.3

Objectives: Recently, [methyl-(11)^C]-(β-Hydroxyethyl)trimethylammonium ([(11)^C]choline) has been discovered to be a very effective tracer in imaging various human tumors using positron emission tomography. Because of the short half-life of C-11, it is very difficult to use in a routine imaging procedure and needs a frequent synthesis of [(11)^]choline. This can be supplemented by the substitution of [(11)^Ccholine with [methyS-18]fluorocholine. Here, we would like to report cell uptake and biodistribution of [(11)^Ccholine and [(18)^F]fluorocholine as a basic study. Methods [(11)^C]Choline was prepared by the treatment of [(11)^C]CHzI with N,N-dimethylaminoethanol and [18F]fluorocholine was synthesized from reaction of CHzBr[18F]F with N,N-dimethylaminoethanol. The radiochemical purity was checked by high performance liquid chromatography (HPLC). The biodistribution of [(11)^C]choline and [(18)^F]fluorocholine was determined in balb/c mouse at 5 min, 20 min, 40 min and 80 min. The cell uptake wa measured using glioma (9L) and colon adeocarcinoma (SW620). Results: The radiochemical purity was more than 98% after purification. In the liver, uptake did not change over time the uptake was 20/ID/g for [C]choline and 13%ID/g for [(18)^F]fluorocholine. In the kidney, radioactivity decreased over tirne the uptake was 15%1D/g for [(11)^Ccholine and 20%ID/g for [(18)^F]fluorocholine, 80 min post-injection. The cell uptake of [(11)^Ccholine was 4.93% for glioma (9L) and 18.69F for colon adenocarcinoma (SW620). For [(18)^F]fluorocholine, 1.77% for glioma (9L) and 2.77% for colon adenocarcinoma (SW620). Conclusion: [(11)^CCholine and [(18)^F]fluorocholine showed a different cell uptake tendency, depending on cancer cell line. (Korean J Nucl Med 200135:185-191)

메스암페타민 사용 환자의 정신과적 증상에 영향을 미치는 요인

이춘우,권성민,조성남,권도훈,임효덕,이성국 대한생물치료정신의학회 2004 생물치료정신의학 Vol.10 No.1

목 적 : 본 연구는 메스암페타민 남용 또는 의존 환자의 사회인구학적 특성과 이에 따른 동반된 정신장애를 알아보고, 메스암페타민 사용이 정신과적 증상에 미치는 영향을 알아보기 위함이다. 방 법 : 2002년 7월부터 2003년 7월까지 국립부곡병원 약물중독진료소에 입원한 환자 중 DSM-Ⅳ 진단 기준에 의하여 메스암페타민 남용 또는 의존으로 진단된 44명의 남자 환자를 대상으로 사회인구학적 변인과 물질 의존의 병력, SCL-90-R, BPRS, HRSD, YMRS, Impulsive scale 등을 측정하였다. 결 과 : 메스암페타민 사용 환자들의 93.2%가 우울하였으며, 59.1%는 치료가 필요한 정도의 우울증을 가지고 있었다. 20대 연령층에서는 대인예민성, 적대감 및 공포증에서 유의하게 높았고, 중졸 이하의 교육 수준에서는 대인예민성, 충동성에서 유의하게 높았으며, 무직인 경우는 강박증, 불만, 적대감 및 조중 척도에서 유의하게 높았다. 처음 사용한 연령은 사용 횟수, 유병 기간과 유의한 상관 관계를 보였으나, 수감 횟수와는 낮은 상관 관계를 보였다. 사용 횟수와 적대감, 공포증, 편집증은 서로 유의한 정상관을 보였다. 우울증 척도와 정신병 척도 및 충동성 척도는 서로 유의한 정상관을 보였다. 100회 미만보다 500회 이상 사용했을 경우에 불안, 적대감, 공포증 및 편집증에서 유의하게 높았다. 결 론 : 메스암페타민 남용 또는 의존 환자에서 우울증 유병률이 매우 높게 나타났고, 20대 연령층과 중졸 이하의 교육 수준 그리고 무직인 경우 정신과적 증상이 많이 동반되었으며, 사용 횟수에 따라 불안, 적대감, 공포증, 편집증에서 유의한 차이를 보였다. 그러므로 모든 메스암페타민 사용자에 대해 적절한 정신과적 평가가 필요할 것으로 생각한다. Objectives : The purpose of this study was to examine the sociodemographic characteristics and the comorbid psychiatric disorders and the effect of methamphetamine use on psychiatric symptoms in methamphetamine abuse or dependent patients. Methods : The study subjects were 44 hospitalized male patients who met the DSM-Ⅳ criteria for methamphetamine abuse or dependence. The study included items assessing the sociodemographic profiles, history of substance use, and psychiatric symptomatology. Psychiatric assessments were based on SCL-90-R, BPRS, HRSD, YMRS and Impulsive scale. Results : In methamphetamine use patients, 93.2% were depressed and 59% had moderate to severe depression There were significant differences in interpersonal- sensitivity, hostility and phobia in the 3rd decade age group, interpersonal-sensitivity and impulsive scale in .under the middle school education group, and obsession-compulsion, anxiety, hostility and. YMRS in no-job group, respectively compared to the other groups. Age of the first use was correlated with the frequency of use, and also with the duration of illness, but not with the number of incarceration. There were positive correlations among HRSD, BPRS and impulsive scale. In the above 500 times used group there were significant differences in anxiety, hostility, phobia and paranoia compared to the below 100 times used group. Conclusion : In methamphetamine abuse or dependent patients, the incidence rate of comorbid depression was 93.2%. In the 3rd decade age group, under the middle school education group and no-job group showed higher diverse psychiatric symptoms compared to the other groups. Frequency of use was positively correlated with the symptoms such as anxiety, hostility, phobia and paranoia. We suggest that relevant psychiatric evaluations are needed for all methamphetamine users.

Effects of Mechanical Stimulation on the Proliferation of Bone Marrow-derived Human Mesenchymal Stem Cells

Choi, Kyung-Min,Seo, Young-Kwon,Yoon, Hee-Hoon,Song, Kye-Yong,Kwon, Soon-Yong,Lee, Hwa-Sung,Park, Jung-Keug Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.6

To support and enhance the in vitro growth and activity of mesenchymal stem cells (MSCs), the cell culture medium may be supplemented with various proteins and factors to mimic the physiological environment in which the cells optimally proliferate and differentiate. In this study, the effects of mechanical factors on cellular metabolic responses were investigated experimentally using a bioreactor. The effects of various chemical factors, such as growth factors, cytokines, and hormones, were also investigated. Based on previous reports demonstrating the important roles of mechanical factors in the growth and activity of MSCs, we sought to evaluate the effects of mechanical stimuli on the proliferation of bone marrow-derived MSCs using a cell training bioreactor that imposed cyclic mechanical stretch, with parameters of 240 min/day, 0.03 Hz, and $5{\sim}15%$ strain. The application of cyclic stretch $(5{\sim}15%\;strain)$ to the MSCs enhanced their proliferation during the early stage(3 days), but not the late stage (14 days), of batch culture. Mechanical stretch did not increase the release of lactate dehydrogenase (LDH) from the MSCs during culture. Appropriate levels of mechanical stretch $(5{\sim}10%\;strain)$ increased collagen synthesis, but did not alter MSC stretch was able to serve as a potent positive modulator of MSC proliferation during the initial stages of culture.

난치성 백반증에 대한 흡입물집을 이용한 비배양 표피세포이식술 20례

배정민 ( Jung Min Bae ),정한미 ( Han Mi Jung ),이한나 ( Han Na Lee ),이로우 ( Ro Woo Lee ),은성혜 ( Sung Hye Eun ),권혁선 ( Hyuck Sun Kwon ),이지혜 ( Ji Hae Lee ),김경문 ( Gyong Moon Kim ) 대한피부과학회 2018 대한피부과학회지 Vol.56 No.7

Background: As nonsurgical interventions for vitiligo are not always successful, various surgical modalities have been used in patients with refractory vitiligo. Of these, non-cultured epidermal suspension transplantation (NCES) was recently introduced to treat large recipient sites using cells from small donor tissue. Objective: We assessed the effectiveness and safety of NCES as a surgical treatment for patients with refractory vitiligo. Methods: We retrospectively reviewed 20 cases in 17 patients (11 females; median age 25 years) who underwent NCES from July 2015 through March 2018. Suction blisters (20 mm in diameter) were collected from the patient’s inner thigh at a donor-to-recipient area ratio of 1:5. After the addition of 5 mL recombinant trypsin solution to the suction blisters, followed by incubation at 37°C for 60 min, epidermal cells were manually scraped off the blister surface, and epidermal cell suspension was obtained by centrifugation at 1,500 RPM for 5 min. The suspension was applied to the vitiligo regions after epidermal ablation of those regions. Phototherapy resumed 1 month later. Treatment success was defined as ≥75% repigmentation of the surgical site, and all adverse events were noted. Results: Overall, 85.0% of cases (17/20) exhibited treatment success. Adverse events included hyperpigmentation (20%) and surgical site infection (5%), but the treatment was tolerable in all cases. Conclusion: NCES is a reliable surgical option for patients with vitiligo refractory to nonsurgical treatment. Large areas of vitiligo can be treated by NCES, and use of this technique should be encouraged in Korea. (Korean J Dermatol 2018;56(7):426∼432)

비만학생들의 운동후 회복시 초과 산소소비량 및 지속시간에 관한 연구

박철호,권민호,고봉민,박은경,우상헌 東亞大學校附設스포츠科學硏究所 1999 스포츠科學硏究論文集 Vol.17 No.-

The purpose of this study was to examine the effect of two different intensity of continuous exercise on magnitude of excess post-exercise oxygen consumption(EPOC), energy consumption following a 20min treadmill exercise. The subjects of this study were eight super-obesity in middle school students who were above 13 years old. subjects participated in two different exercise intensity to measure respiratory gas, blood lactate concentration and eardrum temperature. The results of this study were as follows: 1. The Energy consumption of the high intensity (80% VO₂ max) exercise group (264.68 35.60cal) was greater than that of the low intensity (50%) exercise group(172.01 20.39 Cal)(p<.001). 2. The EPOC of the high intensity exercise group (22.36+ 6.82Cal ) was greater than that of the low intensity exercise group(15.39+5.27 Cal)(p<.001). 3. The EPOC duration of th high intensity exercise group(28.36=3.56min) was longer than that of the low intensity exercise group(17.23+1.25min)(p<.001) 4. The blood lactate concentration, respiratory exchange ratio and temperature of the high intensity exercise group were greater than those of the low intensity exercise group(p<.05,p<.01). EPOC and duration were increase with 80%VO₂max, 80% VO₂max as intensity exercise got higher this also showed that it had something to do with lactate concentration in blood and increase of body temperature in the conclusion. We considered that there was a difference in using methods of energy, as there was a similar difference in RER. We though this following with oxygen consumption after exercise, we could clarify that high intensity exercise was better than lower intensity exercise in sametime for those who are obese especially adolescents to maintain their weights on the aspect of effect.

기계적 자극을 이용한 인체 중간엽줄기세포로부터 유사-섬유모세포로의 분화 유도

최경민 ( Kyung Min Choi ),서영권 ( Young Kwon Seo ),윤희훈 ( Hee Hoon Yoon ),권순용 ( Soon Yong Kwon ),이화성 ( Hwa Sung Lee ),박용순 ( Yong Soon Park ),손영숙 ( Young Sook Son ),송계용 ( Kye Yong Song ),김영진 ( Young Jin Kim 한국조직공학과 재생의학회 2006 조직공학과 재생의학 Vol.3 No.4

Recently, in vitro reconstruction of anterior cruciate ligament(ACL) has been tried using tissue engineering technique, especially mesenchymal stem cell(MSC) is considered as a good cell source. In this study, we tried to find the effect of mechanical stimulus on the differentiation of bone marrow-derived MSC into ACL fibroblastlike cell using a cell training bioreactor imposing cyclic mechanical tension whose parameters were 120 min/day, 1 Hz, and 5% strain. After 2 weeks of culture, MSCs under cyclic tension showed more regularly oriented alignment and lower expression of CD73 and CD105 than control by microscopy and FACS analysis. In transcriptional level, type I collagen, type II collagen, fibronectin, elastin, α-smooth muscle actin mRNA expressions of MSCs under cyclic tension were higher than control and similar to native ACL. In conclusion, it is thought that mechanical cyclic tension induced the loss of stemness of MSC, therefore improved the differentiation into ACL fibroblast-like cell.

습식텍스쳐를 이용한 단결정 실리콘 광학적 · 전기적 특성 연구

한규민(Han Kyu-min),유진수(Yoo Jin-su),유권종(Yoo Kwon-jong),이희덕(Lee Hi-deok),최성진(Choi Sung-jin),권준영(Kwon Jun-young),이준신(Yi Jun-sin) 한국태양에너지학회 2010 한국태양에너지학회 학술대회논문집 Vol.2010 No.4

The presence of ultrasonic wave in caustic cleaning process enhances the remove pollutants, and more homogeneous, textured structure. The silicon wafers, cleaning in Deconex OF 145 solution (0.5~2wt %) with DIW under ultrasonic environment for 5 min. The presence of uniform thin layer of SiO2 on c-Si surface enhances etching rate in the caustic etching mixture solution of NaOH (1.5 wt %), DI water and IPA (6 wt %) at 90℃ for 20 min and results in a fine, more homogeneous and small textured structure.

대학생들의 인터넷 사용정도에 따른 신체활동량과 신체구성의 관련성

김권민(Kim, Gwon-Min),박상갑(Park, Sang-Kab),권유찬(Kwon, Yoo-Chan) 한국체육과학회 2015 한국체육과학회지 Vol.24 No.3

The purpose of this study was to examine the association perceived physical activity patten and body composition according to habitual internet usage among university students. Data were analyzed for 500 students who responded to an self-reported based cross-sectional survey relating to socio-demographic variables, internet usage status, and a long version of the international physical activity questionnaire. Prevalence rate of physical activity status showed that 40.2% at 150 min/week over, 59.8% at 150 min/week under. Prevalence rate of internet usage showed that 94.6% at normal group, 3.0% at potential, 2.4% at addiction. Prevalence rate of physical activity levels of 150 min/week under according to internet usage status showed that 92.0% at normal, 4.3% at potential, 3.7% at addiction. In comparison with the physical activity levels was significantly more likely potential internet usage (OR, 4.82; 95% confidence Interval [95%CI], 1.07, 21.86; p〈.05) and addiction usage (OR, 8.00; 95% confidence interval [95%CI], 1.02, 62.56; p〈.05) The results revealed that physical activity levels correlates of internet usage status. This findings suggests the necessity of developing specific strategies for physical activity intervention by internet addiction among university students.

허혈성 심질환에 있어서 아데노신 급속 정맥투여후 관동맥압의 변화에 관한 연구

봉종대,오종용,배성한,신원용,김철현,이광희,최태명,현민수,김성구,권영주 순천향의학연구소 1998 Journal of Soonchunhyang Medical Science Vol.4 No.2

Background: Adenosine interacts with A1 receptors present on the extracellular surface of cardiac cells, activating K+channels in a fashion. It produces coronary vasodilatation and AV nodal block. The half-time is one to six second and has ultra-short action. In ischemic heart disease, fractional flow reserve(FFR) can be achieved safely with intravenous adenosine infusions at a rate of 150㎍/kg/min which cause maximal coronary hyperemia. Purpose: We investigated the patients who have had ischemic heart disease(n=8). After adenosine intravenous administration(150㎍/kg/min), the effect cause maximal hyperemia of coronary artery. During peak maximal hyperemia, we reported clinical findings, coronary hemodynamics and electrocardiogram findings. Methods: After diagnostic coronary angiography and left ventriculography, catheter was advanced into the ostium of coronary artery. We investigated coronary hemodynamics such as systolic coronary artery pressure, diastolic coronary artery pressure, mean coronary artery pressure and heart rate. To assess the use of adenosine for determination of fractional flow reserve, hemodynamics and electrocardiogram were measured at basal state and during peak maximal hyperemia. Results: Symptoms developed 1.5-2 minute after adenosine intravenous administration and each symptom disappeared 2-2.5 minute after adenosine administration. Two patients represented asymptomatic appearance and six patients complained of flushing, chest pain, palpitation and headache. In eight patients with ischemic heart disease, 1.5 minute after venous administration of 150㎍/kg/min of adenosine, coronary artery pressure decreased and heart rate increased significantly. Conduction abnormalities after administration of 150㎍/kg/min of adenosine were transient 2nd degree AV block 2 cases(25%). Conclusions: Adenosine is a potent ultra short-acting vasodilator. Although coronary artery pressure decreased and heart rate increased and mild cardiovascular symptoms occurred after continuous infusion of 150㎍/kg/min of adenosine, it is useful as an agent for determination of fractional flow reserve.