흰쥐에 Toluene과 Alcohol의 병행투여가 간 손상에 미치는 영향

전재현,임영숙,윤종국 동아시아식생활학회 1996 동아시아식생활학회지 Vol.6 No.3

To evaluate an effect of acute ethanol pretreatment on the liver injury in toluene-treated rats, toluene(50% in olive oil) was intraperitoneally given four times at 0.3㎖/100g body weight at interval of one day to the ethanol-pretreated rats(0.3㎖ of 50%/100g body weight). The increasing rate of liver weight per body weight(%), serum levels of alanine aminotransferase (ALT) activity, liver lipid peroxide content was higher in toluene treated rats pretreated with ethanol than those treated with toluene alone. Concomitantly the hepatic glucose-6-phosphatase activity was increased whereas glutathione content was decreased by ethanol pretreatment before toluene administration in rats. In case of direct administration of acetaldehyde or benzaldehyde to the rats, the liver weight per body weight(%) and serum levels of ALT activity were almost higher than the control group. There results indicate that the toluene treated rats showed the reversible injury of liver and intensified, however, by the ethanol treatment.

발치 및 비발치 치료 전후 악궁 폭경의 변화

전지윤,김수정,강승구,박영국 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.1

일반적으로 네 개의 소구치 발치를 동반한 교정치료는 비발치 치료에 비하여 치열궁 폭경을 더 좁게 만들어, 미소 시 구각 부위에 어두운 구강 내 공간, 소위 buccal corridor를 형성함으로써 비심미적인 결과를 낳는다는 견해가 있다. 한편 발치 치료는 오히려 하악의 견치간 폭경을 증가시키며, 비발치 치료와 비교하여 악궁 폭경의 변화에 있어 유의한 차이를 보이지 않는다는 상반된 연구결과가 존재한다. 이 연구는 발치 치료와 비발치 치료 시 악궁 폭경의 변화를 관찰하여 실제적으로 발치 치료가 미소 시 협측 분절에 미치는 영향을 규명하고자 시행되었다. 경희대학교 치과병원 교정과에서 치료받은 환자 중 전악에 고정식 장치를 사용하여 네 개의 제1소구치 발치 치료를 받은 30명과 비발치로 치료한 30명의 치료 전후 연구 모형을 비교 분석한 결과 악궁 폭경의 변화는 다음과 같다. 네 개의 제1소구치 발치 치료 시 비발치 치료와 비교하여 상악의 견치간 폭경 변화는 유의한 차이가 없었으나, 하악의 견치간 폭경은 유의하게 더 많이 증가하였다. 구치간 폭경 변화는 상악과 하악 치열궁 모두에서 두 군 간에 유의한 차이가 나타났는데, 발치군에서 구치간 폭경이 감소한 반면에 비발치군에서는 구치간 폭경이 증가하였다. 미소 시 노출되는 악궁 폭경은 비발치군보다 발치군에서 더 크게 나타났으며, 이는 치열궁 폭경의 축소가 발치 치료 시 당연히 예상되는 결과가 아님을 시사한다. Objective: This study was performed to investigate the influences of extraction and nonextraction treatment on smile esthetics by measuring dental arch width changes. Methods: Pretreatment and posttreatment study models of 30 first premolar extraction cases and 30 nonextraction cases were randomly selected to determine whether extraction treatment results in narrow dental arches, and a consequent unaesthetic smile. Arch widths were measured from the cusp tips of the canines and the first molars. Posterior arch widths were also measured at a constant arch depth derived by averaging randomly chosen nonextraction models. Results: The intercanine widths increased significantly in the extraction sample, whereas the intermolar widths decreased significantly. The arch width at a standardized arch depth was significantly wider in the extraction subjects. Conclusion: These results elucidate that constriction in arch width is not a materialized consequence of extraction treatment. It leads to postulate that an esthetically compromising effect from narrow dental arches on smile is hardly anticipated with extraction treatment.

농촌지역의 생활폐기물 발생 특성 : 경북지역을 중심으로 Detailed Kyeongbuk Area

권기홍,조병락,전영국 영남이공대학 산업기술연구소 2003 産業技術硏究 Vol.15 No.-

This study was carried out to investigate the generation and physico-chemical composition of solid wastes in the Kyeongbuk area. As a result, the generation rate of municipal solid wastes(MSWs) in the Kyeongbuk area have been lower('96 : 43,757ton/day → '01 : 42,384ton/day), but recyclable wastes of them have been higher ('96 : 10,592ton/day →'01 : 12,828ton/day). The annual generation rate of MSWs in the country was 0.96kg in 1996, 0.92kg in 2001, respectively, it has maintained below 1.0kg, but it was 1.03kg in 1996, 0.94kg in 2001 in Kyeangbuk area, respectively. In MSWs, food wastes in the country and the Kyeongbuk area are 8,510kg and 493kg, and separation rate of food waste are 37.8% and 59.4%, respectively. Totally the generation rate of MSWs was decreased, but recyclable products of MSWs was increased. Three components, heating value, elements analysis in 2001 was similer to 1996's results.

브라켓과 탄선 간의 마찰 전후 표면 변화 분석 : 원자현미경을 이용한 예비연구

이태희,박기호,전지윤,김수정,박헌국,박영국 대한치과교정학회 2010 대한치과교정학회지 Vol.40 No.3

브라켓과 호선 간에 발생하는 마찰은 치아 이동의 효율에 상당한 영향을 미친다. 마찰력에 기여하는 요소 중 특히 브라켓과 호선의 표면조도는 중요한 요소이다. 본 연구는 브라켓과 탄선을 실험적으로 마찰시킨 후, 원자현미경 (atomic force microscope, AFM)을 사용하여 브라켓 슬롯과 교정용 탄선의 표면 조도 변화를 정성적, 정량적으로 측정하고 비교 평가하여 브라켓과 호선 간의 마찰이 각각의 표면 변화에 미치는 영향을 규명하고자 시행되었다. 스테인리스 스틸 브라켓과 세라믹 브라켓에 각각 스테인리스 스틸 탄선과 TMA 탄선을 실험적으로 활주마찰시킨 후 각각을 원자현미경을 이용하여 표면을 관찰하였다. 실험결과 브라켓보다는 교정용 탄선에서 활주마찰 후에 더 많은 표면 변화가 나타났다. 또한 활주마찰 후에 스테인리스 스틸 브라켓은 표면 조도의 유의한 변화가 없었으나 세라믹 브라켓은 표면 조도가 감소하였다. 그리고 교정용 탄선은 모두 활주마찰 후에 표면 조도가 증가하였으며 이러한 표면 변화는 스테인리스 스틸 브라켓보다 세라믹 브라켓과의 활주마찰 후에 더 큰 것으로 관찰되었다. 본 실험으로 원자현미경은 브라켓 슬롯과 탄선의 표면 조도를 정량적으로 측정하는 데에 유용한 수단임을 알 수 있었다. Objective: The surface roughness of orthodontic materials is an essential factor that determines the coefficient of friction and the effectiveness of tooth movement. The aim of this study is to evaluate the surface roughness change of the brackets and wires after experimental sliding quantitatively. Methods: Before and after experimental sliding tests, the surface roughness of stainless steel brackets, ceramic brackets, stainless steel wires, and beta-titanium (TMA) wires were investigated and compared using atomic force microscopy (AFM). Results: After sliding tests, changes in the surface of the wire were greater than changes in the bracket slot surface. The surface roughness of the stainless steel bracket was not significantly increased after sliding test, whereas the roughness of ceramic brackets was decreased. Both the surface roughness of stainless steel and TMA wires were increased after sliding test. More changes were observed on the ceramic bracket than the stainless steel bracket. Conclusions: AFM is a valuable research tool when analyzing the surface roughness of the brackets and wires quantitatively.

Maxillofacial Trauma Trends at a Tertiary Care Hospital: A Retrospective Study

Jeon, Eun-Gyu,Jung, Dong-Young,Lee, Jong-Sung,Seol, Guk-Jin,Choi, So-Young,Paeng, Jung-Young,Kim, Jin-Wook Korean Association of Maxillofacial Plastic and Re 2014 Maxillofacial Plastic Reconstructive Surgery Vol.36 No.6

Purpose: Maxillofacial fractures are rapidly increasing from car accidents, industrial accidents, teenaged criminal activity, and sports injuries. Accurate assessment, appropriate diagnosis, and preparing individual treatment plans are necessary to reduce surgical complications. We investigated recent trends of facial bone fracture by period, cause, and type, with the objective of reducing surgical complications. Methods: To investigate time trends of maxillofacial fractures, we reviewed medical records from 2,196 patients with maxillofacial fractures in 1981~1987 (Group A), 1995~1999 (Group B), and 2008~2012 (Group C). We analyzed each group, comparing the number of patients, sex ratio, age, fracture site, and etiology. Results: The number of patients in each period was 418, 516, and 1,262 in Groups A to C. Of note is the increase in the number of patients from Group A to C. The sex ratios were 5.6:1, 3.5:1, and 3.8:1 in Groups A, B, and C. The most affected age group for fracture is 20~29 in all three groups. Traffic accidents are the most common cause in Groups A and B, while there were somewhat different causes of fracture in Group C. Sports-induced facial trauma was twice as high in Group C compared with Group A and B. Mandible fracture accounts for a large portion of facial bone fractures overall. Conclusion: We observed an increase in facial bone fracture patients at Kyungpook National University Dental Hospital over the years. Although facial injury caused by traffic accidents was still a major cause of facial bone fracture in all periods, the percentage decreased. In recent years, isolated mandible fracture increased but mandible and mid-facial complex fracture decreased, possibly because of a reduction in traffic accidents.

[화학] α-Cyclodextrin으로 화학수식된 Carbon Paste 전극의 특성

전영국(Young-Guk Jeon),김봉원(Bong-Weon Kim),김희정(Hee-Jung Kim),조영달(Young-Dal Cho),정진갑(Chinkap Chung) 한국분석과학회 1996 분석과학 Vol.9 No.3

Influence of Interrupted ZnO Buffer Layer on Optical and Structural Properties of ZnO Thin Films Grown by Plasma-Assisted Molecular Beam Epitaxy

Min Young Cho,Byeong Guk Choi,Jae Min Lim,Su Min Jeon,Hyun Young Choi,Ghun Sik Kim,Do Yeob Kim,Min Su Kim,Jin Soo Kim,Joo In Lee,Sung Dong Park,Myong Hyo Jung,Jae-Young Leem 한국진공학회 2009 한국진공학회 학술발표회초록집 Vol.37 No.-

Five-year outcomes of sirolimus-eluting versus paclitaxel-eluting stents: A propensity matched study: Clinical evidence of late catch-up?

Ko, Young-Guk,Kim, Jung-Sun,Choi, Donghoon,Hong, Myeong-Ki,Min, Pil-Ki,Yoon, Young Won,Hong, Bum-Kee,Lee, Byoung-Kwon,Kwon, Hyuck-Moon,Kim, Byeong-Keuk,Oh, Sung-Jin,Jeon, Dong-Wun,Yang, Joo-Young,Jang Elsevier 2011 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.152 No.3

<P><B>Abstract</B></P><P><B>Background</B></P><P>Siroliums-eluting stents (SES) and paclitaxel-eluting stents (PES) have been widely used for the treatment of coronary artery disease. We investigated 5-year clinical outcomes of patients treated with SES versus PES in a multicenter registry.</P><P><B>Methods</B></P><P>We used a propensity score matching method with 2:1 matching, including 512 patients treated with SES and 256 patients treated with PES from March 2003 to December 2004. The primary endpoint was major adverse cardiac events, which included all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR).</P><P><B>Results</B></P><P>After matching, baseline characteristics were similar between the two groups. At 5years, cumulative survival free of major adverse cardiac events, MI, and stent thrombosis did not differ between the two groups. Survival free of TVR at 5years was higher in the SES group (88.4%) than the PES group (84.3%, Log-rank <I>p</I>=0.016). In contrast to the trend toward more likely target lesion revascularization in the PES group during the first 2years (hazard ratio 0.62, <I>p</I>=0.057), target lesion revascularization tended to occur more frequently in the SES group from 2 to 5years (hazard ratio 2.26, <I>p</I>=0.099).</P><P><B>Conclusions</B></P><P>Long-term risk of TVR was slightly lower with SES, compared with PES, despite no significant difference in major adverse cardiac events. However, the SES group had more frequent target lesion reintervention 2 to 5years after stent implantation, whereas reintervention in the PES group occurred mainly within the first 2years. This may reflect the temporal difference in neointimal growth of the two stent types.</P>

MBE Growth and Investigate Optical Properties of Mg-Doped GaAs Epitaxial Layer

Hyun Young Choi,Su Min Jeon,Min Young Cho,Ghun Sik Kim,Do Yeob Kim,Min Su Kim,Dong Kyun Jeong,Byeong Guk Choi,Jin Soo Kim,Jong Su Kim,Jeong-Sik Son,Gi-Seog Eom,Jae-Young Leem 한국진공학회 2009 한국진공학회 학술발표회초록집 Vol.37 No.-

A study on the dynamic behavior of the Korean next-generation high-speed train

Jeon, Chang-Sung,Kim, Young-Guk,Park, Joon-Hyuk,Kim, Seog-Won,Park, Tae-Won Professional Engineering Publishing Ltd 2016 Proceedings of the Institution of Mechanical Engin Vol. No.

<P>This study describes the dynamic behavior of the HEMU-430X, the Korean next-generation high-speed train. The HEMU-430X was initially analyzed using VAMPIRE, a computer program that is used to examine the dynamics of railway vehicles, based on which it was expected to sway strongly at its tail end. This hunting motion was expected to disappear when the position of the yaw damper was changed. The dynamic behavior of the HEMU-430X was assessed in an on-track test performed using the protocols in the EN14363 standard and measuring the carbody, bogie and axle accelerations; the HEMU-430X was found to satisfy the safety criterion. The hunting motion appeared at speeds of 150, 350 and 387km/h, and countermeasures such as changing the position of the yaw damper, installing carbody dampers, and increasing the damping coefficient of the yaw damper installed on the motor car containing the driver's cab were taken in order to reduce the vibrations. Ultimately, the highest test speed achieved was 421.4km/h. Subsequently, it was found that the critical speed tended to decrease with mileage. This was attributed to excessive lateral damping and a revised design was proposed to solve this problem.</P>