0.412 MeV 감마선에 대한 원주형 NaI(Tl) 섬광체의 총 절대검출효율 계산

홍권표,신희성,이상윤,노성기 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.4

Total absolute detection efficiencies of a 7.62 cm(dia.) and 7.62 cm(height) cylindrical NaI(Tl) crystal have been calculated for 0.412 MeV r -rays from a source(point, circular disk, square and line type). In this calculation the linear energy-absorption coefficients based on Hubbell's data have been considered and then calculated total absolute detection efficiencies compared with those from Grosjean and Bossaert. Besides, the source axis-to-detector axis shift distance which, could give rise to about 0.05% deviation in the total absolute detection efficiencies has been calculated for a line-type source of 0.5 cm in its length when a source-to-detector distance is 5 cm. It is revealed that the total absolute detection efficiencies obtained in this study are considerably different from those of Grosjean and Bossaert. In addition it is found that the deviation induced due to an imperfect center of a line type source may be within 0.05% if the shifted discrepancy is no larger than 1.74mm.

武道選手들의 競技前 競爭不安에 關한 硏究

송순천,김진표,이권노 龍仁大學校 1997 용인대학교 논문집 Vol.14 No.-

The purpose of this study was to test marshal art players' unstable psychological conditions before their competitions. For this purpose, 42 Judo players, 32 Taekwondo players, 21 boxers and 21 wrestlers(total 126 players) who belonged to "Y" university training camp were sampled to be subject to the SCAT test in order to verify the differences of their psychological conditions by grade and event. The results of this study can be summarized as follows ; 1) As a result of testing the hypothesis 1, it was found that there were significant differences of psychological apprehensive conditions before competition among graders. Those freshmen players showed the highest level of apprehension(2.7500), followed by senior, sophomore and junior groups. 2) As a result of testing the hypothesis 2, it was found that there were no signifieant differences of psychological apprehensive conditions before competition among events. The boxers showed the highest level of apprehension (2.6938), followed by wrestlers, Judo players and Taekwondo players. 3) As a result of testing the hypothesis 3, it was found that there were significant differences of psychological apprehensive conditions before competition among events in case of freshmen and junior groups, while there were no significant differences of such conditions before competition among events in case of sophomore and seior groups.

간내 담관암의 초음파 및 전산화 단층촬영소견 : Ultrasound and CT Findings

김완진,김표년,김일영,홍현숙,이혜경,권귀향,김기정 순천향대학교 1995 Journal of Soonchunhyang Medical Science Vol.1 No.1

A Study on the Isozymic Alterations of Lactic Dehydrogenase in the Tissues of Rats Following Sulfur Dioxide Exposure

Kwon, Sook Pyo Yonsei University, College of Medicine 1969 Yonsei medical journal Vol.10 No.1

Exposure to Ethyl Carbamate by Consumption of Alcoholic Beverages Imported in Korea

Kwon-Pyo Hong,Yoon-Seok Kang,Dong-Chae Jung,Sae-Rom Park,Ji-Ho Yoon,Sung-Yong Lee,Yong Seok Ko,So Hee Kim,Sang-Do Ha,Sang Kyu Park,Dong-Ho Bae 한국식품과학회 2007 Food Science and Biotechnology Vol.16 No.6

Determination of ethyl carbamate content in imported alcoholic beverages in Korea and an exposure assessment were conducted. In gas chromatography/mass spectrometry/selected ion monitoring (GC/MS/SIM) analysis, 2.5-39, 8-263, 6.3-112, 11.3-23.5, 53-94, 8.5-38.5, 7-9.5, 21.3-31.5, 5-832.5, and 10.5-364.8 μg/L of ethyl carbamate were detected in imported beers, sakes, whiskies, vodkas, Chinese liquors, cognacs, tequilas, rums, liqueurs, and wines, respectively. The exposure assessment indicated that the exposure of Korean adults to ethyl carbamate were lower than 20 ng/kg BW per day, (the virtual safe dose) indicating that the amount of ethyl carbamate exposed through fermented food and alcoholic beverages including imported products are currently in the ‘no significant risk level’. However, the present low exposure to ethyl carbamate through the imported alcoholic products was not due to the low contents of ethyl carbamate in imported products, but low consumption of the imported products. Therefore, given increasing importation of alcoholic beverages in Korea, reductions of ethyl carbamate content in imported alcoholic beverages, especially non-distilled products, should be required by regulating limits on the ethyl carbamate content in the imported alcoholic beverages.

Basal Serum Cortisol Levels are not Predictive of Response to Corticotropin but Have Prognostic Significance in Patients with Septic Shock

Kwon, Yong Soo,Suh, Gee Young,Kang, Eun-Hae,Koh, Won-Jung,Chung, Man Pyo,Kim, Hojoong,Kwon, O Jung KOREAN ACADEMY OF MEDICAL SCIENCE 2007 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.22 No.3

<P>Because high levels of cortisol are frequently observed in patients with septic shock, low levels of serum cortisol are considered indicative of relative adrenal insufficiency (RAI). This study was performed to investigate whether pretest clinical characteristics, including basal serum cortisol levels, are predictive of serum cortisol response to corticotropin and whether basal cortisol levels have a prognostic significance in patients with septic shock. We performed a retrospective analysis of 68 patients with septic shock who underwent short corticotropin stimulation testing. RAI was defined as an increase in cortisol level <9 µg/dL from baseline, and results showed that 48 patients (70.6%) had this insufficiency. According to the univariate analysis, the RAI group had significantly higher simplified acute physiology score II (SAPS II) and sequential organ failure assessment (SOFA) scores than the non-RAI group. The incidence of RAI was the same regardless of the basal serum cortisol level (<I>p</I>=0.447). The hospital mortality rate was 58.8% and was not significantly different between the RAI and non-RAI groups. However, a high basal serum cortisol level (≥30 µg/dL) was significantly associated with in-hospital mortality. In conclusion, our data suggest that basal serum cortisol levels are not predictive of serum cortisol response to corticotropin but have a significant prognostic value in patients with septic shock.</P>

The Role of Ballooning in Patients with Post-tuberculosis Bronchial Stenosis

Kwon, Yong Soo,Kim, Hojoong,Kang, Kyung Woo,Koh, Won Jung,Suh, Gee Young,Chung, Man Pyo,Kwon, O Jung The Korean Academy of Tuberculosis and Respiratory 2009 Tuberculosis and Respiratory Diseases Vol.66 No.6

Background: In order to access the role of ballooning in patients with post-tuberculosis bronchial stenosis (PTBS), medical records of patients who underwent the procedure were reviewed. Methods: Twenty-nine PTBS patients underwent balloon dilatation between May 1999 and November 2000 at Samsung Medical Center. The median age was 28 (range 16~62 year) and most patients were female (n=27, 93%). The mean number of ballooning procedures was 2.4 (range 1~8) and the interval between ballooning procedures was 76.2$\pm$69.7 days. Results: In general, the $FEV_1$ was improved after ballooning (from 66.2.$\pm$11.9% predicted to 73.5$\pm$13.0% predicted, p=0.0004). Among 29 patients who underwent ballooning, a clinically successful outcome was observed in 16 patients (55%). Comparison between the successful and unsuccessful groups showed that favorable factors for a successful outcome were a higher pre-9ballooning $FEV_1$ (71.1$\pm$8.1 vs. 60.2$\pm$13.3% predicted), higher post-9ballooning $FEV_1$ (89.2$\pm$7.8 vs. 63.4$\pm$9.2% predicted) and absence of left upper lobe collapse. The clinical outcome was unsuccessful in all eight patients with a pre-9ballooning $FEV_1$ $\leq$57% of predicted or with complete left upper lobe collapse. Conclusion: In conclusion, ballooning appears to be helpful in patients with PTBS, especially when the pre-ballooning $FEV_1$ >57% of predicted and there is no complete left upper lobe lung collapse.

Hepatitis C Virus Infection and Hepatotoxicity During Antituberculosis Chemotherapy

Kwon, Yong Soo,Koh, Won-Jung,Suh, Gee Young,Chung, Man Pyo,Kim, Hojoong,Kwon, O. Jung American College of Chest Physicians 2007 Chest Vol.131 No.3

<P>BACKGROUND: The risk of drug-induced hepatotoxicity (DIH) during treatment for tuberculosis (TB) in patients who are seropositive for the hepatitis C virus (HCV) is not clear. We evaluated whether HCV-seropositive patients are at a higher risk of DIH than control subjects during treatment for TB with standard short-course regimens. METHODS: Fifty-four HCV-seropositive patients with newly diagnosed active TB who were treated with isoniazid, rifampin, ethambutol, and/or pyrazinamide were included in the study population. Ninety-seven HCV-seronegative patients were selected as control subjects. RESULTS: Forty HCV-seropositive patients (74%) and 82 control subjects (85%) received an initial treatment regimen that included pyrazinamide. Twenty-two HCV-seropositive patients (41%) and 19 control subjects (20%) exhibited elevated liver enzyme levels during TB treatment, including transient elevation of transaminase. DIH, defined as a liver transaminase level >/= 120 IU/L, occurred more frequently in HCV-seropositive patients (7 of 54 patients, 13%) than in control subjects (4 of 97 patients, 4%). Isoniazid and rifampin were reintroduced after the liver transaminase level returned to baseline in five HCV-seropositive patients exhibiting DIH, and all these retrials proved to be successful. CONCLUSIONS: These findings suggest that treatment for TB in HCV-seropositive patients could be pursued in the usual manner, using standard short-course regimens, with the condition that monthly liver function tests are carefully performed.</P>

Reduction-sensitive and cysteine residue-mediated Streptococcus pneumoniae HrcA oligomerization in vitro

Kwon, Hyog-Young,Kim, Eun-Hye,Tran, Thao Dang Hien,Pyo, Suhk-Neung,Rhee, Dong-Kwon Springer-Verlag 2009 Molecules and cells Vol.27 No.2

<P>In both gram-positive and several gram-negative bacteria, the transcription of dnaK and groE operons is negatively regulated by HrcA; however, the mechanism modulating HrcA protein activity upon thermal stress remains elusive. Here, we demonstrate that HrcA is modulated via reduction and oligomerization in vitro. Native-PAGE analysis was used to reveal the oligomeric structure of HrcA. The oligomeric HrcA structure became monomeric following treatment with the reducing agent dithothreitol, and this process was reversed by treatment with hydrogen peroxide. Moreover, the mutant HrcA C118S exhibited reduced binding to CIRCE elements and became less oligomerized, suggesting that cysteine residue 118 is important for CIRCE element binding as well as oligomerization. Conversely, HrcA mutant C280S exhibited increased oligomerization. An HrcA double mutant (C118S, C280S) was monomeric and exhibited a level of oligomerization and CIRCE binding similar to wild type HrcA, suggesting that cysteine residues 118 and 280 may function as checks to one another during oligomer formation. Biochemical fractionation of E. coli cells overexpressing HrcA revealed the presence of HrcA in the membrane fraction. Together, these results suggest that the two HrcA cysteine residues at positions 118 and 280 function as reduction sensors in the membrane and mediate oligomerization upon stress.</P>

Deformation Twinning in Nb-Microalloyed Fe-Mn-C-Al Twinning-Induced Plasticity Steel

Kwon, Eui Pyo,Kim, Dae Young,Park, Hyun Kyeong Springer-Verlag 2017 JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE Vol.26 No.9

<P>Work hardening and deformation twinning in microalloyed Fe-Mn-C-Al twinning-induced plasticity (TWIP) steel with Nb were investigated in this study, and it was found that the addition of Nb affected the work-hardening behavior of TWIP steel. Moreover, the quantitative characterization of twinning was performed on the deformed microstructure by electron backscattering diffraction analysis, and the results indicate that the addition of Nb causes a reduction in twinning kinetics. The decrease in deformation twinning in TWIP steel with added Nb can be attributed to the effect of fine grain, dislocations in non-recrystallized grains, and the formation of twins on a particular grain orientation.</P>