Light-extraction efficiency control in AlGaN-based deep-ultraviolet flip-chip light-emitting diodes: a comparison to InGaN-based visible flip-chip light-emitting diodes.

Lee, Keon Hwa,Park, Hyun Jung,Kim, Seung Hwan,Asadirad, Mojtaba,Moon, Yong-Tae,Kwak, Joon Seop,Ryou, Jae-Hyun Optical Society of America 2015 Optics express Vol.23 No.16

<P>We study light-extraction efficiency (LEE) of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) using flip-chip (FC) devices with varied thickness in remaining sapphire substrate by experimental output power measurement and computational methods using 3-dimensional finite-difference time-domain (3D-FDTD) and Monte Carlo ray-tracing simulations. Light-output power of DUV-FCLEDs compared at a current of 20 mA increases with thicker sapphire, showing higher LEE for an LED with 250-관m-thick sapphire by ~39% than that with 100-관m-thick sapphire. In contrast, LEEs of visible FCLEDs show only marginal improvement with increasing sapphire thickness, that is, ~6% improvement for an LED with 250-관m-thick sapphire. 3D-FDTD simulation reveals a mechanism of enhanced light extraction with various sidewall roughness and thickness in sapphire substrates. Ray tracing simulation examines the light propagation behavior of DUV-FCLED structures. The enhanced output power and higher LEE strongly depends on the sidewall roughness of the sapphire substrate rather than thickness itself. The thickness starts playing a role only when the sapphire sidewalls become rough. The roughened surface of sapphire sidewall during chip-separation process is critical for TM-polarized photons from AlGaN quantum wells to escape in lateral directions before they are absorbed by p-GaN and Au-metal. Furthermore, the ray tracing results show a reasonably good agreement with the experimental result of the LEE.</P>

추황배(Pyrus pyrifolia Nakai cv. Chuhwangbae) 과피로부터 1종의 Sterol과 3종의 배당체 화합물의 단리·동정

이유건(Yu Geon Lee1),조정용(Jeong-Yong Cho),이현주(Hyun Joo Lee),이용현(Yong Hyun Lee),이상현(Sang-Hyun Lee),한태호(Tae-Ho Han),김월수(Wol-Soo Kim),박근형(Keun-Hyung Park),문제학(Jae-Hak Moon) 한국식품과학회 2013 한국식품과학회지 Vol.45 No.5

본 연구에서는 배의 유용성 증명을 위한 일환으로 배의 화학성분을 분자수준에서 밝히고자 하였다. 이에 배 과피 MeOH 추출물을 용매분획하여 얻은 EtOAc-산성 분획과 EtOAc-중성분획을 대상으로 Sephadex LH-20, silica gel, 그리고 ODS colmn chromatography와 HPLC를 이용하여 정제 및 단리하였다. 그 결과, EtOAc-산성 분획과 EtOAc-중성 분획으로부터 각각 2종씩의 화합물을 단리하였다. 단리된 화합물 1-4는 1H- 및 13C-NMR 분석을 통하여 각각 (S)-(+)-2-cis-abscisic acid O-β-D-glucopyranosyl ester (화합물 1), 1-[4-O-β-D-glucopyranosyl]phenyl ethanone(piceoside, 화합물 2), β-sitosterol (화합물 3), 그리고 β-sitosteryl 3-O-β-D-glucopyranoside (화합물 4)로 동정되었다. 단리된 3종의 배당체 화합물(화합물 1, 2, 4)들은 본 연구에 의해 배로부터 처음 동정되었으며, 화합물 3은 추황배로부터 처음 동정되었다. 본 연구결과가 배 함유 성분연구는 물론 배의 기능성 해명 연구에도 추후 중요한 기초자료로 활용되길 기대한다. We isolated and identified antioxidants from acidic and neutral ethyl acetate fractions of the peel of pear (Pyrus pyrifolia N. cv. Chuhwangbae). We isolated 4 compounds from the methanol extract, by using 3 different types of column chromatography (Sephadex LH-20, silica gel, and octadecylsilane) and preparative HPLC. We identified the isolated compounds as (S)-(+)-2-cis-abscisic acid O-β-D-glucopyranosyl ester (compound 1), 1-[4-O-β-D-glucopyranosyl]phenyl ethanone (picroside, compound 2), β-sitosterol (compound 3), and β-sitosteryl 3-O-β-D-glucopyranoside (compound 4) by nuclear magnetic resonance analysis. We are the first to report the identification of compounds 1, 2, and 4 from pear.

KAERI 부지 주변의 환경선량 측정을 위한 온라인 감마선량 감시시스템

이정호,박두원,이원윤,이현덕,최용호,김삼랑,홍광희,이창우 대한방사선 방어학회 1994 방사선방어학회지 Vol.19 No.2

환경감마선량 변동을 감시하기 위해 한국원자력연구소 부지 주변에 온라인 감마선량 감시망을 구성하였다. 모니터링 포스트에 설치된 전리함 검출기에 의해 측정된 자료는 무선전송방식으로 중앙통제소에 전송되어 실시간으로 감시된다. 무선전송 방식은 자료의 전송, 처리 및 자자에 신뢰도가 높고 경제적이었다. 감시시스템은 급격한 선량증가시 조기경보체제와 연결할 수 있게 하였다. On-line gamma monitoring system around KSERI-site was set up to monitor the radiation fluctuations in environment. Data on gamma exposure rates measured by the ionication chamber in the monitoring posts are transmitted to a computer of central control station with radio telemetry transmission and reliable on handing and storing of data. This monitroing system can triger an early warning system in the event of abnormal radiation levels.

경북 최초의 신장이식 1례

이중현,김용섭,이정호,이창우,김상욱,이문섭,오민구,하달봉,이경섭 동국대학교 의학연구소 2000 東國醫學 Vol.7 No.-

신장이식은 환자의 삶의 질을 높이고 거의 정상적인 사회생활을 가능하게 함으로써 말기신부전 환자의 3가지 신대체 요법(혈액투석, 복막투석, 신장이식) 중에 가장 효과적이고 각광받는 치료법이라 할 수 있다. 최근 들어 의료기술과 의학의 발달로 신장이식의 성공률은 과거에 비해 비약적으로 높아지고 있으며 국내에서도 점차 신장이식수술을 받는 환자가 증가하고 있으나 서울이나 다른 대도시에 비해 의료환경이 열악한 중소도시나 지방의 병원에서는 아직도 시행하지 못하고 있는 형편이다. 이에 저자들은 경북 최초로 자체 의료진에 의해 고혈압과 말기 신부전으로 동국대 포항병원에서 혈액투석을 받고 있던 32세의 남자환자에게 부인으로부터 신장을 제공받아 신장이식을 성공적으로 시행하였기에 문헌고찰과 함께 보고하고자 한다. Kidney transplantation is the preferred treatment modality for many patients with end-stage renal disease (ESRD), because it offers improved quality of life over both hemodialysis and peritoneal dialysis. Patients who do well after transplantation generally report improvement in vitality and freedom to return to the style of life that they experienced before their progression to ESRD. Recently, the success rate of kidney transplantation is greatly being increased as the surgical technique and immunosuppressive drugs are developed. Kidney transplantation is also popular in Korea which has good result. But, until now the general hospitals which are located at small city can't try the kidney transplantation because they don't have proper facilities and experts. We firstly experienced a case of kidney transplantation in a 32 years old man with hypertension and chronic renal failure at KyoungBuk province. So we report this case with references.

장상피화생과 Helicobactor pylori와의 상관 관계에 관한 연구

이복희,김대수,이현숙,진영주,윤세진,송형근,성노현,정현용,이동호 충남대학교 의과대학 지역사회의학연구소 1994 충남의대잡지 Vol.21 No.2

In 1965 Lauren divided advanced gastric carcinoma into two main types-namely, "intestinal" and "diffuse" type carcinoma, which differ not only morphologically but also in their clinical and epidemiological characteristics. Moreover, a different histogenetic process has been postulated by many authors that intestinal type gastric carcinoma might arise from areas with intestinal metaplasia. Since Warren and Marshall reported the presence of Helicobacter pylori in the stomach in 1983, strong evidence has been obtained that there is a close relationship between Helicobacter pylori and chronic gastritis, atrophic gastritis, intestinal metaplasia, and intestinal type gastric carcinoma. To study the relationship between intestinal metaplasia and Helicobacter pylori infection, we performed gastroscopic biopsies and CLO tests taken from patients with epigastric pain. Only 87 patients with macroscopically suspected antral gastritis were included. The prevalence of intestinal metaplasia in gastric antral biopsies increased from 33.3% in the age group<30 years to 63.6% in the age group 60 years. When all patients were divided into two age groups-namely, (i)<50 years(n=41) and (ii)≥ 50 years(n-=46), intestinal metaplasia was found significantly more often in patients ≥ 50 years. ((i) 39.2%, (ii) 54.3%, p<0.0001). The prevalence of Helicobacter pylori in gastric antral biopsies decreased from 66.7% in the age group<30 years to 62.5%, in the age group in the age group 50 to 59 years. When all patients were divided into the same two age groups-namely(i)<50 years and (ii)≥50 years, the prevalence of Helicobacter pylori did not differ between two groups in a statistically significant way. The mean age of intestinal metaplasia positive patients who were also Helicobacter pylori positive was 48±11.0(mean±S.D.)years, whereas the mean age of intestinal metaplasia positive patients who were Helicobacter pylori negative was 52±9.7(mean±S.D.)years. In conclusion. although our data do not prove a causal relationship between Helicobacter pylori infection and the histogenesis of intestinal metaplasia, we suggest that Helicobacter pylori plays an important role in the development of intestinal metaplasia in the gastric mucosa. Whether Helicobacter pylori has to be present at all times during this process or is only necessary as a 'trigger', needs further research.

업종에 따른 연 취급 사업장의 기중 연 농도 및 연 노출 수준 평가

이병국,김용배,리갑수,안현철,김화성,이용진,황규윤,장봉기,이성수,안규동 순천향대학교 산업의학연구소 1999 순천향산업의학 Vol.5 No.1

In order to obtain an useful information for health management and biological monitoring of lead exposed workers, Authors tried to investigate air lead level and the lead exposed level of workers in lead industry according to occupational category. The subjects in our study were 2074 workers in 7 lead-using industries, and study subjects were divided into 4 occupational categories such as storage battery industry (type 1), primary smelting industry (type 2), secondary smelting industry (type 3) and litharge making industry (type 4). Blood zincprotoporphyrin concentration (ZPP), blood lead concentration (PbB) and urinary δ -aminolevulinic acid (ALAU), hemoglobin (Hb), hematocrit (Hct) were selected as the indices of lead exposure. Personal variables such as age, work duration were also collected. The results were as follows. 1. The geometric mean air lead in 9 lead-using industry was 0.1133±4.3120 ㎎/㎥, and that in type 1, 2, 3 and 4 was 0.1038±3.4952 ㎎/㎥, 0.0429±3.4329 ㎎/㎥, 0.1877±2.5123 ㎎/㎥ and 0.9961±5.2910 ㎎/㎥, respectively. 2. The mean ZPP in 9 lead-using industry was 53.1±28.0 ㎍/㎗, and that in type 1, 2, 3 and 4 was 52.0±24.8 ㎍/㎗, 48.0±16.4 ㎍/㎗, 109.8±85.6 ㎍/㎗ and 74.3±37.8 ㎍/㎗, respectively. There was significant difference in ZPP according to occupational category (P<0.01). The percents of lead workers whose ZPP were above 100 ㎍/㎗ in type 1, 2, 3 and 4 were 4.0%, 1.7%, 34.3% and 21.6%, respectively. 3. The mean PbB in lead-using industry was 26.0±11.2 ㎍/㎗, and that in type 1, 2, 3 and 4 was 25.3±11.1 ㎍/㎗, 26.7±8.8 ㎍/㎗, 50.3±15.2 ㎍/㎗ and 36.4±11.0 ㎍/㎗, respectively. There was significant difference in PbB according to occupational category (P<0.01). The percents of lead workers whose PbB were above 40 ㎍/㎗ in type 1, 2, 3 and 4 were 10.4%, 7.7% 71.9% and 43.2%, respectively. 4. While the correlation of Hb corrected PbB with ZPP was higher than non corrected PbB, the correlation of log-transformed ZPP with PbB was higher than non corrected ZPP. 5. Simple linear regressions of PbB and corrected PbB as independent variable with ZPP, log-transformed ZPP and ALAU as dependent variable were statistically significant (P0.01). Coefficient of determination of corrected PbB with other variables was higher than non corrected PbB. As the result of this study, it was suggested that reconsideration of environmental and biological monitoring program was highly recommended for secondary smelting and litharge making industry.

In situ 고상 에피택시 방법에 의한 CoSi₂/Si(111)구조의 형성

이정주,강민성,김현수,최치규,이운환,이종덕,이영백,김건호,이정용 濟州大學校 基礎科學硏究所 1996 基礎科學硏究 Vol.9 No.2

초고진공에서 공상에피택시(solid-phase epiyaxy, SPE) 방법으로 CoSi₂를 Si(111)기판 위에 에피택시 성장시켰다. 2MeV⁴He++ ion후방산란 분광기와 사중결정 x-선 회절기 및 고분해 투과전자 현미경을 이용하여 성장된 CoSi₂의 상과 조성, 결정성, 그리고 계면의 미시구조를 조사하였다. 초고진공상태의 실온에서 Si(111)-7X7기판에 Co를 약 20 ~50 ?? 중착한 후 SPE에 의하여 실리사이드를 형성시키는 경우 600℃에서는 B-형의 CoSi₂가, 그리고 700℃에서는 A형의 CoSi₂가 선택적으로 에피택시 성장하였으며, 정합성은 B-CoSi₂[110]//Si[110] and CoSi₂(111)//Si(111)이, 그리고 700℃에서는 A-CoSi₂[110]//Si[110], CoSi₂(002)//Si(002)을 나타내었다. Epitaxial films of CoSi₂were grown on Si(111) substrates by in situ solid-phase epitaxy in a ultrahigh vacuum. The phase, the chemical composition, the crystallinity, and the microstructure of the Silicide/Si interface were investigated by 2-MeV⁴He++ ion-backscattering spectrometry, quadruple crystal X-ray diffractometry, and high-resolution transmission eletron micorscopy. High-quality films of either B-type or A-type CoSi₂ could be grown selectively on Si(111) substrates by depositing ~ 20 ~ 50 ?? of Co on a Si(111)-7X7 substrate followed by in situ annealing at 600℃ or 700℃ for 10 min. The matching face relationships are CoSi₂[110]//Si[110] and CoSi₂(111)//Si(111) by B-type CoSi₂ and CoSi₂[110]//Si[110]//Si[110] and CoSi₂(002)//Si(002) for A-type CoSi₂.

칼라센서를 이용한 도정도 측정장치 개발

이용국,이대원,윤두현,이재현 성균관대학교 생명과학자원연구소 1996 生命資源科學硏究 Vol.3 No.2

A whiteness measurement system was designed and constructed using the color sensor. The results of its performance were compared with commercial product (Japan, Kett Co.). A degree of rice milling grading is very closely related to the rice color. Measuring and evaluating the small amount of the reflectance depend on the system including color sensor, light source, detector sensitivity, and its geometric shapes. The main components of prototype included lamps as a light source, Amorphous full color sensor with three filters, D. C. power supply, amplifier, A/D converter, and compatible PC computer. Based on the results of this research the following conclusions were made: [1] It was considered suitable that the amorphous full color in the system was used in rice milling degree measurement. [2] The results of comparison between prototype and the Kett whiteness meter were showed that correlation coefficient of prototype was 0.9687 and that of the commercial whiteness meter was 0.9954.

급성 단순하부요로감염의 경험적 치료로써 레보플록사신 3일요법의 효과

이지열,이승주,이상돈,정희창,오봉렬,김세웅,최한용,조용현,윤문수 대한화학요법학회 2001 대한화학요법학회지 Vol.19 No.4

목적 : 급성 단순요로감염의 원인균에 대한 내성증가에 따른 경험적 1차치료의 선택에 대한 어려움으로 인하여 최근 미국의 Infectious Disease Society of America(IDSA)에서는 이에 대한 가이드라인을 제시하였다. IDSA의 가이드라인에 따르면 그 지역의 TMP-SMX에 대한 내성균주의 비율이 10-20% 이상일 때는 급성 단순요로감염의 경험적 1차치료제로 플루오로퀴놀론제를 선택하도록 하였다. 이에 저자들은 급성 단순하부요로감염 환자에 있어서 레보플록사신에 대한 임상적, 미생물학적 유효성 및 안전성을 알아보고자 하였다. 방법 : 시험은 전향적, 비맹검, 공개, 비비교, 다기관 임상시험으로 시행되었고 전국 5개 대학병원을 방문한 56명의 급성 단순하부요로감염 환자에게 레보플록사신 100㎎을 1일 3회, 3일간 경구 투여하여 1-3일 후에 추적 관찰하였다. 결과 : 평가가 가능하였던 53명의 환자 중 50명의 환자에서 치료 후 5-7일 후에 증상이 소실되었거나 호전되어 94%의 임상적 유효성을 보였으며, 51명의 환자에서 치료 후 1-3일 후에 원인균이 제거되어 96%의 미생물학적 유효성을 보였다. 약물 관련 이상반응은 2%의 환자에서 나타났으나 이로 인한 치료 중단 사례는 없었으며 심각한 생화학적 또는 혈액학적 이상반응은 나타나지 않았다. 결론 : 레보플록사신 100㎎ 1일 3회 3일 요법은 임상적, 미생물학적 유효성이 뒤어나며 안전한 치료요법으로 급성 단순하부요로감염의 경험적 1차 치료에 적합할 것으로 생각된다. Background : The increasing frequency of clinical failure of uncomplicated urinary tract infections (UTIs) may be due to emerging resistance to commonly prescribed antimicrobials. Infectious Diseases Society of America guidelines state that uncomplicated UTIs should be treated empirically with a fluoroquinolone, if the proportion of trimethoprim/sulfamethoxazole-resistant isolates in the community is >10%-20%. The clinical efficacy and safety of levofloxacin were assessed in patients with acute, uncomplicated lower urinary tract infection. Methods : The study was a multicenter, prospective, open label, non-comparative, non-blinded trial. Fifty-six patients with acute, uncomplicated symptomatic lower urinary tract infections from five university hospitals were treated with levofloxacin 100㎎ tid for 3 days and were followed up for 1 to 5 days. Results : Fifty-three of the 56 patients were evaluable. Ninety-four per cent of patients were symptomatically cured or improved by the fifth to seventh day after therapy started. Bacteriological eradication of initial pathogen was achieved by 1 to 3 days in 96%. Drug related adverse experiences were seen in 2% of patients. None necessitated cessation of therapy. No significant biochemical or hematological abnormalities occurred. Conclusion : These results demonstrate the clinical efficacy and safety of empirical 3-day levofloxacin for acute, uncomplicated urinary tract infections.

통합심리치료의 인지분화훈련이 정신분열병 환자의 기초 인지기능에 미치는 영향

이희상,현명호,조현상,이연희,김태용,장순아,노규식,정기립,이만홍,유계준 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.5

연구목적 : 정신분열별 환자들을 대상으로 통합심리치료의 소프로그램인 인지분화훈련을 실시하여 실행기능, 개념형성능력, 언어능력 및 추론력에 대한 훈련이 보다 더 하위단계의 인지기능인 주의력, 기억력, 반응시간 등을 호전시킬 수 있는 지를 알아보고자 하였다. 연구방법 : DSM-IV상 정신분열병으로 진단된 24명의 입원환자를 무작위로 양분하여 한 군은 인지분화훈련군으로 다른 한 군은 대조군으로 나누었다. 훈련군은 4주동안 1주일에 3회(매회 60분간)로 총 12회의 통합심리치료의 인지분화훈련을 받았으며 대조군은 동일한 시간동안 정신건강교육을 받았다. 훈련전후에 훈련군과 대조군을 대상으로 개정판 Wechsler 기억검사로 주의집중력, 장·단기 기억력을 측정하였고 Vienna test system중 결정반응시간검사로 반응시간, 반응결정시간, 반응운동시간을 평가하였다. 연구결과 : 1) 주의집중력에서는 훈련군과 대조군사이에 집단간 효과, 집단내 효과 및 상호작용 효과가 없었다. 2) 단기기억력에서는 훈련군과 대조군사이에 집단내 효과는 있었으나(F(1,24)=10.46. p〈.05). 집단간 효과, 상호작용 효과는 없었다. 3) 장기기억력에서는 훈련군과 대조군사이에 집단내 효과는 있었으나(F(1,24)=15.09. p〈.05). 집단간 효과, 상호작용 효과는 없었다. 4) 반응시간에서는 상호작용 효과(F(1,24)=5.18, p〈.05)가 있었다. 5) 반응운동시간에서는 집단간 효과, 집단내 효과 및 상호작용 효과가 없었다. 6) 반응결정시간에서는 상호작용 효과(F(1.24)=6.00, p〈.05)가 있었다. 결 론 : 통합심리치료의 인지분화훈련은 정신분열병 환자에서 하위단계의 인지기능 중 반응시간(특히 반응결정시간)을 단축시키는 효과가 있었다. Objectives : The purpose of this study was to investigate the effects of cognitive differentiation training of Integrated Psychological Therapy(a training program of executive function, concept formation, language, and abstraction) on micro-level cognitive function such as attention, memory and reaction time in patients time in patients with schizophrenia. Methods : Twenty-four inpatients diagnosed as schizophrenia using DSM-IV were randomly assigned to 2 groups. The training group went through a total of 12 sessions of cognitive differentiation training for 4 weeks. The control group received psychoeducation program during the same period. Wechsler Memory Scale-Revised and Decision-Reaction Timer of Vienna Test System were administered to all patients, both before and after the training program. Results : 1) In the attention and concentration scores of Wechsler Memory Scale-Revised, between group, within group and interaction effects of training were not significant. 2) In the short-term memory scores of Wechsler Memory Scale-Revised, within group effect of training was significant(F(1,24)=10.46, p〈0.05), but the between group and interaction effects did not reach significance. 3) In the long-term memory scores of Wechsler Memory Scale-Revised, within group effect of training was significant(F(1,24)=15.09, p〈0.05), but the between group and interaction effects did not reach significance. 4) In the reaction time scores of Decision-Reaction Timer, interaction effect of training was significant(F(1,24)=5.18, p〈0.05). 5) In the motor time scores of Decision-Reaction Timer, between group, within group and interaction effects of training were not significant. 6) In the decision time scores of Decision-Reaction Timer, interaction effect of training was significant(F(1,24)=6.00, p〈0.05). Conclusion : Our findings suggest that cognitive differentiation training of Integrated Psycho-logical Therapy is partly effective on improving micro-level cognitive functions such as reaction time(especially, decision time) in patents with schizophrenia.