20대 연령의 안정성 한계(Limits of Stability)에 대한 연구

권오윤,장정훈 원광보건전문대 1995 원광보건전문대학논문집 Vol.18 No.-

스테로이드를 투여 받는 환자에서 발생한 Nocardia farcinica 뇌 종양 1예

심성훈,박혜인조,김충종,전재현,김의종,오명돈,김남중,최강원 대한감염학회 2008 감염과 화학요법 Vol.40 No.5

Nocardiosis occurs mostly in the immunocompromised patients. N. farcinica is known to have resistance to some antibiotics and significant increase in morbidity and mortality in patients requiring long-term treatment. Nocardia farcinica infection, especially brain abscess, has not been reported in Korea. Here, we report a case of N. farcinica brain abscess in a patient receiving steroid treatment. The patient was a 64 year-old male with gouty arthritis, He received steroid for more than two months, because of allopurinol-hypersensitivity syndrome with skin rash. After three months of steroid therapy, he visited other hospital with mild fever and left thigh pain and was diagnosed of intramuscular abscess due to gram positive bacilli. One month later, he visited our hospital with right side weakness and was diagnosed as brain abscess. The causative organism turned out to be N. farcinica, which was confirmed by means of 16S rRNA sequencing. Antibiotics were selected by E-test results and treatment was successful.

직렬 리액터를 이용한 계통연계형 태양광 발전 시스템

金大均,鄭春炳,全基英,李丞煥,吳鳳煥,李勳九,金容珠,韓慶熙 명지대학교 산업기술연구소 2005 産業技術硏究所論文集 Vol.24 No.-

Since the residential load is an AC load and the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feedforward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

Superconducting MgB2 Wire Drawing Considering Anisotropic Hardening Behavior and Hydrostatic Effect

Young‑Seok Oh,Ho Won Lee,Kook‑Chae Chung,Duck‑Young Hwang,Seong‑Hoon Kang,Jeong Whan Yoon 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Numerical modeling was conducted to investigate the deformation behavior of powder mixture during multi-pass drawingprocesses for multi-filamentary MgB2wire. A modified Drucker-Prager Cap (DPC) model with an elliptical cap surface usingthe new material characterization method was developed to capture the anisotropic hardening behavior and hydrostatic effectof the powder mixture. A number of uniaxial die compaction, cold isostatic pressing, diametrical compression, and uniaxialcompression tests were conducted using different powder densities to characterize the modified DPC model. A commercialfinite element software ABAQUS with a user subroutine was used to simulate the drawing of the MgB2wire. The densityand area fraction of the powder mixture during the wire-drawing process were verified with experimental results. The differencein packing density at the inner and outer filaments of the MgB2wire was successfully captured by simulation. Inaddition, the effect of the initial packing density on the superconducting properties of MgB2wire was numerically studied. It is shown that the increase in the superconducting area, which results from a high initial packing density, should be moreeffective compared to the increase in the grain connectivity in enhancing the critical current properties for the MgB2wirewhen the final packing density is saturated after a number of drawing processes.

상아질 접착제의 중합 시간 조절에 따른 복합레진의 중합 수축 방향의 변화

배지현,오명환,김창근,손호현,엄정문,조병훈,권혁춘 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.4

The purpose of this study was to evaluate the effect of adhesive curing timing on the direction of polymerization shrinkage of light-curing composite resin. In this study, the curing times of adhesive and composite resin were measured by differential scanning calorimeter(DSC). 28 extracted human molars were embedded in clear resin and box-type cavities were prepared. Based on DSC data. the experimental teeth were divided into 4 groups. Group 1: no bond: Group 2: late curing: Group 3: Intermediate curing: Group 4: Early curing. After treating with adhesive, the buccal cavities were filled with Z-100 hybrid composite resin and the lingual ones were filled with AEliteflo flowable composite resin. The depressions at the surface were measured by surface profilometer, then the specimens were embedded in clear resin and sectioned. Impressions were obtained and used to get epoxy resin replicas. The epoxy replicas were gold-coated and observed under SEM. Average Maximum Gap(AMG), Gap Proportion(GP), Average Marginal Index(AMI) were used to compare the shrinkage gap of each group. The results were statistically analyzed using the Kruskal-Wallis One Way ANOVA, Student-Newman-Keuls method. The results of this study were as follows. 1. Average Maximum Gap. Gap Proportion, Average Marginal Index and depression at the surface of Z-100 hybride composite resin were smailer than those of AEliteflo flowable composite resin(P(0.05) 2. When the bonding between composite resin and tooth structure was strong, the shrinkage gap was small, and depression at the surface was deep(P<0.05). 3. In the well-bonded group. light-curing composite resin shrank toward bonded cavity wall. not toward light source. The result suggested that the direction of polumerization shrinkage was affected by the quality of bonding in the dentin-resin interface. The strong was the bonding between composite resin and tooth structure, the smaller was the gap and the deeper was the depression at the surface. Then the flow to compensate the polymerization shrinkage proceeded from surface to bonded cavity wall.

Flowable 및 microfill 복합레진으로 충전된 제 5급와동에서 load cycling 전,후의 미세변연누출 비교

강석호,김오영,오명환,조병훈,엄정문,권혁춘,손호현 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.2

Low-viscosity composite resins may produce better sealed margins than stiffer compositions (KempScholte and Davidson, 1988; Crim, 1989). Flowable composites have been recommended for use in Class V cavities but it is also controversial because of its high rates of shrinkage. On the other hand, in the study comparing elastic moduli and leakage, the microfil had the least leakage (Rundle et al. 1997). Furthermore, in the 1996 survey of the Reality Editorial Team, microfills were the clear choice for abfraction lesions. The purpose of this study was to evaluate the microleakage of 6 composite resins (2 hybrids, 2 microfills, and 2 flowable composites) with and without load cycling. Notch-shaped Class V cavities were prepared on buccal surface of 180 extracted human upper premolars on cementum margin. The teeth were randomly divided into non-load cycling group (group 1) and load cycling group(group 2) of 90 teeth each. The experimental teeth of each group were randomly divided into 6 subgroups of 15 samples. All preparations were etched, and Single bond was applied. Preparations were restored with the following materials (n=15) : hybrid composite resin [Z250(3M Dental Products Inc. St.Paul, USA), Denfil(Vericom, Ahnyang, Korea)], microfil [Heliomolar RO(Vivadent, Schaan, Liechtenstein), Micronew(Bisco Inc. Schaumburg, IL, USA)], and flowable composite[AeliteFlo(Bisco Inc. Schaumburg, IL, USA), Revolution(Kerr Corp. Orange, CA, USA)]. Teeth of group 2 were subjected to occlusal load (100N for 50,000 cycles) using chewing simulator(MTS 858 Mini Bionix Ⅱ system, MTS Systems Corp., Minn, USA). All samples were coated with nail polish 1mm short of the restoration, placed in 2% methylene blue for 24 hours, and sectioned with a diamond wheel. Enamel and dentin/cementum margins were analyzed for microleakage on a sclale of 0 (no leakage) to 3 (3/3 of wall). Results were statistically analyzed by Kruskal-Wallis One way analysis, Mann-Whitney U-test, and Student-Newmann-Keuls method. (p=0.05) Results: 1. There was significantly less microleage in enamel margins than dentinal margins of all groups. (p<0.05) 2. There was no significant difference between six composite resin in enamel margin of group 1. 3. In dentin margin of group 1, flowable composite had more microleakage than others but not of significant differences. 4. There was no significant difference between six composite resin in enamel margin of group 2. 5. In dentin margin of group 2, the microleakage were R>A=H=M>D>Z. But there was no significant differences. 6. In enamel margins, load cycling did not affect the marginal microleakage in significant degree. 7. In dentin margins, load cycling did affect the marginal microleakage only in Revolution. (p<0.05)

접착제와 와동형성의 차이에 따른 5급 복합레진 수복의 전향적 임상연구

이경욱,정세준,한영철,손호현,엄정문,오명환,조병훈 大韓齒科保存學會 2006 Restorative Dentistry & Endodontics Vol.31 No.4

본 연구의 목적은 복합레진을 이용한 비우식성 치경부 5급 병소 수복에 있어서, 3가지 다른 접착제를, 유지구를 부여한 치아와 부여하지 않은 치아에 적용하였을 때의 임상적인 효능의 차이를 비교하기 위함이다. 총 150개의 치아를 각각 25개씩 6개의 군으로 나누었다. A군 Scotchbond Multi-Purpose (SBMP, 3M ESPE, St, Paul, MN, USA, 4세대 접착제)를 사용하고 유지구를 부여하지 않음. B군: SBMP를 사용하고 유지구를 부여. C군: BC Plus (Vericom Co., Anyang, Gyeonggido, Korea, 5세대 접착제)를 사용하고 유지구를 부여하지 않음. D군: BC Plus를 사용하고 유지구를 부여. E군: Adper Prompt (3M ESPE, Seefeld, Germany, 6세대 접착제)를 사용하고 유지구를 부여하지 않음. F군: Adper Prompt를 사용하고 유지구를 부여. 모든 치아는 복합레진인 Denfil(Vericom Co., Anyang. Gyonggido. Korea)을 이용하여 충전하였다. 수복 직후와, 수복 6개월 후에 modified USPHS (United States Public Health Service) criteria에 따라 수복물을 임상적으로 평가하였다. 추가적으로 임상사진을 촬영하였으며, 에폭시 레진을 이용하여 복제한 후 주사전자현미경을 이용하여 이를 관찰하였다. 6개월 후 관찰 결과. alpha rating의 수가 각 실험군마다 동일하지는 않았지만, 통계적으로는 3가지의 접착제간에 유의할만한 차이는 없었고, 기계적인 유지구를 부여한 군과 부여하지 않은 군 간에도 유의할만한 차이는 없었다 (p > 0.05). 그러나 6개월의 관찰 기간은 일반적으로 기대되는 레진의 수명보다 짧기 때문에, 각 실험군 간의 차이를 알아보기 위해서는 추후 더 오랜 기간의 관찰이 요구된다. The purpose of this study is to evaluate prospectively the effect of different bonding systems and retention grooves on the clinical performance of resin restorations in non-carious cervical lesions (NCCLs). Thirty nine healthy adults who had at least 2 NCCLs in their promolar areas were included in this study. One hundred and fifty teeth were equally assigned to six groups; (A) Scotchbond Multi-Purpose (SBMP, 3M ESPE, St, Paul, MN, USA, 4th generation bonding system) without retention grooves; (B) SBMP with retention grooves: (C) BC Plus (Vericom Co., Anyang, Gyeonggido, Korea, 5th generation bonding system) without retention grooves; (D) BC Plus with retention grooves; (E) Adper Prompt (3M ESPE, Seefeld, Germany, 6th generation bonding system) without retention grooves: (F) Adper Prompt with retention grooves. All cavities were filled with a hybrid composite resin, Denfil (Vericom Co., Anyang, Gyeonggido, korea) by one operator. Restorations were evaluated at baseline and at 6-month recall, according to the modified USPHS (United states Public Health Service) criteria, Additionally, clinical photographs were taken and epoxy resin replicas were made for SEM evaluation. At 6-month recall, there were some differences in the number of alpha ratings among the experimental groups. But, despite the differences in the number of alpah ratings, there was no significant difference among the 3 adhesive systems (p > 0.05). There was also no significant difference between the groups with or without mechanical retention (p > 0.05). Follow-ups for longer periods than 6 months are needed to verify the clinical performance of different bonding systems and retention grooves. 〔J Kor Acad Cons Dent 31(4):300-311, 2006〕

Kahweol inhibits proliferation and induces apoptosis by suppressing fatty acid synthase in HER2-overexpressing cancer cells

Oh, Suck Hoon,Hwang, Yong Pil,Choi, Jae Ho,Jin, Sun Woo,Lee, Gi Ho,Han, Eun Hee,Chung, Young Ho,Chung, Young Chul,Jeong, Hye Gwang Elsevier 2018 Food and chemical toxicology Vol.121 No.-

<P><B>Abstract</B></P> <P>Kahweol is a coffee-specific diterpene found in the beans of <I>Coffea arabica</I> and has been reported to demonstrate various biological activities, including anti-inflammatory, antioxidant, and apoptotic properties. In the present study, we examined the molecular mechanism of kahweol in human epidermal growth factor receptor-2 (HER2)-overexpressing breast cancer cells. Kahweol preferentially inhibited cell proliferation and induced cell death through the induction of a caspase 3-dependent pathway in HER2-overexpression breast cancer cell lines. Kahweol treatment substantially reduced the levels of HER2 protein, mRNA, and transcriptional activity in SKBR3 cells. Kahweol exerts its potent anticancer efficacy by the upregulation of polyomavirus enhancer activator 3 (PEA3) and downregulation of activator protein 2 (AP-2) to inhibit aberrantly activated HER2 signaling. Fatty acid synthase (FASN) expression and sterol regulatory element-binding protein-1c (SREBP-1c) activity were downregulated by kahweol. In addition, kahweol lowered the levels of phosphorylated Akt and its downstream targets mammalian target of rapamycin (mTOR) and cyclin D1. Furthermore, we found that blocking Akt signaling through kahweol treatment significantly reduced FASN expression and subsequently suppressed cell proliferation in HER2-overexpressing cancer cells. Overall, this study suggests that kahweol could be a useful adjuvant therapeutic agent in the treatment of HER2-overexpressing breast cancer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Kahweol, a coffee-specific diterpene, exhibits anti-tumor effect in HER2-overexpressing cancer cells. </LI> <LI> Kahweol inhibits proliferation and induces apoptosis <I>through the</I> downregulation of FASN and HER2 expression. </LI> <LI> Kahweol inhibits HER2 expression and activity through the regulation of PEA3 and AP-2. </LI> <LI> Kahweol inhibits the phosphorylation of Akt, mTOR, and GSK3β. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

근위 상완골 분쇄 골절에서 골편 이식술과 Low Profile 삽입물을 이용한 인공관절 반치환술

오정희 ( Chung Hee Oh ),오주한 ( Joo Han Oh ),김세훈 ( Sae Hoon Kim ),조기현 ( Ki Hyun Jo ),빈성우 ( Sung Woo Bin ),공현식 ( Hyun Sik Gong ) 대한골절학회 2008 대한골절학회지 Vol.21 No.3

목적: 근위 상완골 분쇄 골절에서 골편 이식술과 low profile 삽입물 (Aequalis(R) 골절 삽입물)을 이용한 인공관절 반치환술의 결과를 분석하였다. 대상 및 방법: Low profile 삽입물을 이용하여 치료한 16명의 근위 상완골 분쇄 골절 중 11명에서 평균 19.9 (12~30)개월간 추시하였다. 평균 연령은 67.3 (52~78)세였다. 통증과 수술 만족도 VAS, 관절 범위, 변형 UCLA 접수를 매 추적 관찰 시 조사하였고, 최종 추시 방사선 사진으로 스템의 위치 및 이완, 결절의 유합을 조사하였다. 결과: 평균 통증 VAS는 2.7 (0~5), 평균 수술 만족도 VAS는 8.4 (5~10), 평균 전방거상은 137 (90~170)도, 외회전은 45.5 (25~70)도, 내회전은 흉추 10번 (흉추 7번~요추 1번)이었으며, 변형 UCLA 접수는 19 (12~30)점이었다. 모든 스템은 이완 소견 없이 안정적이었다. 결절은 모두 유합되었으나, 대 결절과 소 결절의 흡수가 각 1예에서 있었다. 결론: 골편 이식술과 low profile 삽입물을 이용한 근위 상완골 분쇄 골절의 치료는 비교적 우수한 결과를 보였고, 다른 삽입물에 견주어 결절의 유합에 장점을 보인다고 생각되지만, 장기간의 추시와 많은 증례가 필요할 것으로 생각된다. Purpose: To evaluate the outcome of hemiarthroplasty with bone block graft and low profile prosthesis (Aequalis(R) fracture prosthesis) for the comminuted proximal humerus fractures. Materials and Methods: Sixteen low profile prostheses were used since July 2004, and 11 patients were followed-up for average 19.9 (12~30) months. Their mean age was 67.3 (52~78) years. Pain and satisfaction visual analog scale (VAS), range of motion, and modified UCLA score for hemiarthroplasty were evaluated at every visit. Radiography was also checked for stem position, loosening, and tuberosity union. Results: Mean pain VAS was 2.7 (0~5), and mean satisfaction VAS was 8.4 (5~10). Mean active forward flexion was 137° (90~170), external rotation at side was 45.5° (25~70), and internal rotation at back was T10 (T7~L1). Modified UCLA score was 19 (12~30) at final visit. All stems were stable, and there were no loosening at the final follow-up. All tuberosities were united except two tuberosity absorptions. Conclusion: The outcome of hemiarthroplasty with bone block graft and low profile prosthesis was comparable to other implants for comminuted proximal humerus fractures. This system had unique advantages for tuberosity union. Further study with more patients and longer follow-up are necessary to clarify the effectiveness of this prosthesis.

유아내사시에서 양안 내직근후전술의 장기효과

오청훈 ( Chung Hoon Oh ),조윤애 ( Yoonae A. Cho ) 대한안과학회 2002 대한안과학회지 Vol.43 No.9