In_xGa_1-xN/GaN 다중양자우물 구조의 광학적 성질 연구

김기홍,김인수,박헌보,배인호,유재인,장윤석,Kim, Ki-Hong,Kim, In-Su,Park, Hun-Bo,Bae, In-Ho,Yu, jae-In,Jang, Yoon-Seok 한국진공학회 2009 Applied Science and Convergence Technology Vol.18 No.1

$In_xGa_{1-x}N$/GaN 다중양자우물 구조의 EL 특성을 온도와 주입전류 변화에 따른 특성을 조사하였다 저전류와 고전류 주입시 EL 효율의 온도 의존 변화는 매우 다르게 나타나는데, 이러한 온도와 전류의 변화에 의한 독특한 EL 효율의 변화는 내부전기장의 존재 하에 순방향 바이어스에 기인한 외부전기장의 영향인 것으로 볼 수 있다. 그리고 $In_xGa_{1-x}N$/GaN 다중양자우물 구조에서 In 성비의 증가는 발광파장위치의 적색이동을 보였다. 15K에서 주입 전류의 증가에 따라 녹색 양자우물 구조는 80 meV와 청색 양자우물 구조는 22 meV의 청색 편이를 하였다. 이는 전류의 증가에 의해 단위 시간당 생성되는 캐리어 수가증가하게 되고 그에 따라 subband가 급격히 채워지는 band filling 현상이 일어나게 되어 짧은 파장에서 재결합이 증가하기 때문이다. 그리고 청색과 녹색 다중 양자우물구조의 짧은 파장 쪽으로의 편이 차이는 In 농도에 기인한 것으로 In 농도가 높으면 양자우물 깊이가 증가되어 더 강한 양자속박효과가 작용하여 캐리어 구속력이 증가하기 때문 것으로 볼 수 있다. Temperature and injection current dependence of electroluminescence(EL) spectral intensity of the $In_xGa_{1-x}N$/GaN multi-quantum wells(MQW) have been studied over a wide temperature range and as a function of injection current level. It is found that a temperature-dependent variation pattern of the EL efficiency under very low and high injection currents shows a drastic difference. This unique EL efficiency variation pattern with temperature and current can be explained field effects due to the driving forward bias in presence of internal(piezo and spontaneous polarization) fields. Increase of the indium content in $In_xGa_{1-x}N$/GaN multiple quantum wells gives rise to a redshift of 80 meV and 22 meV for green and blue MQW, respectively. It can be explained by carrier localization by potential fluctuation of multiple quantum well and MQW structures also shows a keen difference owing to the different indium content in InGaN/GaN MQW.

공군사관생도의 심폐능력에 따른 심리 · 생리요인 비교

김인기(In-ki Kim),김건희(Gun-hee Kim),송성우(Sung-woo Song),최가람(Ga-ram Choi),엄장원(Jang-won Eom),곽재준(Jae-jun Kwak),유영남(Young-nam You),정덕화(Deok-hwa Jeong),강지훈(Ji-hun Kang) 육군사관학교 화랑대연구소 2019 한국군사학논집 Vol.75 No.2

The purpose of this study was to analyze the differences in psychological and physiological factors between groups by classifying groups based on the 3km running record of fourth grade Air Force Academy cadets. Among the top 46 Air Force Academy cadets who wanted to participate in the study, the study conducted an open survey of the top 13 and the bottom 15 who wanted to provide the data prior to the study. The subjects of the experiment and in-depth interview were studied by a total of 18 people, 9 of each upper and lower members who wished to participate in the study. Psychological factors were structured through inductive content analysis of data extracted from in-depth interviews, and physiological factors were conducted to verify differences between groups of body composition and cardiopulmonary function. The psychological factors of the upper and lower groups were found to be general areas of performance strategy, achievement motivation, emotional response, military spirit, situation perception, and basic physical strength. In the detailed areas, the subjects were also examined in 15 areas including physical fitness indicators, confidence, condition control, task orientation, and positive self-perception. As a result of comparison between upper and lower groups, the upper group was 2.2 times higher than the lower group and the lower group was 1.7 times higher than the upper group in the military spirit and performance strategy of the general area response rate. In general area response, the ratio of mental strength and confidence was different in the general area of military spirit. In addition, the upper group in the achievement motivation showed a high percentage of task tendency at 47%, while the lower group showed a high rate of zero motivation at 50%. In the emotional response, the upper group showed an equal ratio, while the lower group showed an 81% ratio of negative emotions. In the overall response by sub-region, the negative emotions of the subgroup were high at 28%. In the body composition, BFM showed a statistically significant difference between upper and lower groups, and Weight, FFM, and SMM did not show any significant difference between groups. In cardiopulmonary capacity, VO2max showed a statistically significant difference between upper and lower groups, and VE and LT did not show significant differences between groups.

백서의 실험적 당뇨병이 태자 폐성숙에 미치는 형태학적 변화에 관한 연구

金容薰,李廣吉,최인준 연세대학교 의과대학 1984 연세의대논문집 Vol.17 No.1

Adult invasive pneumococcal disease in the Republic of Korea: Risk medical conditions and mortality stratified by age group

Kim, Jong Hun,Baik, Seung Hee,Chun, Byung Chul,Song, Joon Young,Bae, In-Gyu,Kim, Hyo Youl,Kim, Dong-Min,Choi, Young Hwa,Choi, Won Suk,Jo, Yu Mi,Kwon, Hyun Hee,Jeong, Hye Won,Kim, Yeon-Sook,Kim, Jeong Elsevier 2018 INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES Vol.74 No.-

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>This study aimed to characterize the risk factors for mortality in adult patients with invasive pneumococcal disease (IPD) stratified by age groups, after implementation of the national immunization program of 23-valent polysaccharide vaccine (PPSV23) for those aged ≥65 years in the Republic of Korea (ROK).</P> <P><B>Methods</B></P> <P>Clinical data and pneumococcal isolates from adult patients with IPD (≥18 years of age) were collected prospectively from 20 hospitals through the nationwide surveillance program from March 2013 to October 2015.</P> <P><B>Results</B></P> <P>A total of 319 patients with IPD were enrolled. Median age was 69 years. Overall in-hospital mortality was 34.2%: 17.1% in those aged 18–49 years, 23.7% in those aged 50–64 years, 33.0% in those aged 65–74 years, and 51.0% in those aged ≥75 years (<I>p<</I> 0.001). In particular, early death within 7days of hospitalization accounted for 60.6% (66/109). While old age (≥65 years), higher Pitt bacteremia score (≥4), and bacteremic pneumonia were independently associated with IPD mortality in all age groups, an additional mortality risk factor of immunocompromised status was identified for patients aged 50–64 years. PPSV23 serotypes accounted for 64.4% (122/189) of the pneumococcal isolates serotyped.</P> <P><B>Conclusions</B></P> <P>This study suggests that vaccine-type IPD continues to place a substantial burden on older adults in the ROK, necessitating an effective vaccination strategy for those at higher risk.</P> <P><B>Highlights</B></P> <P> <UL> <LI> National immunization of the elderly with the 23-valent polysaccharide vaccine (PPSV23) was implemented in Korea in 2013. </LI> <LI> Overall in-hospital mortality was 34.2% for adult invasive pneumococcal disease (IPD) and 51.0% for patients ≥75 years of age. </LI> <LI> Mortality risks were older age, higher bacteremia score, and immunocompromised status. </LI> <LI> An effective vaccination strategy for those at higher risk of IPD is needed. </LI> </UL> </P>

흰쥐에서 에스트로젠 결핍이 하악골 골밀도에 미치는 영향

김기현,신상훈,김욱규,박봉수,정인교 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.2

The relationship between systemic bone loss(osteopenia) and loss of oral bone has been of considerable recent interest. In dentistry, some investigators have studied using human subjects, but no firm conclusion due to many obstacles have yet been obtained. From these obstacles in the assessment of human subjects, the significance of investigations with overiectomized rats has been proposed recently. Also, in ovariectomized rats, quantitative data on changes in the alveolar bone of mandible and basal bone of mandible using dual-energy x-ray absorptiometry(DEXA) were far fewer. The purposes of this study were to certify systemic estrogen deficiency-induced osteopenia by biochemical markers(serum osteocalcin(OC) & urinary deoxypyridinoline(DPD)) and bone mimeral density(BMD) of femur by DEXA and examine changes in BMD of the rat mandible by DEXA with 24-week-old female Sprague-Dawley rats. Forty eight rats were used in this study and twenty four rats were ovariectomized bilaterally(OVX) to induce systemic osteopenia and remainders were subjected to sham surgery(Sham). The experimental rats were killed at different time interval(1st, 2nd, 3rd, 4th, 6th, 8th, 12th and 16th week) for histologic examination, biochemistry analysis and BMD measurement. The results obtained from this study were as follows: On histological examination, in mandible, early degeneration of periodontal ligament, early bone resorption in alveolar bone and late bone resorption in basal bone were observed. On biochemical analysis, OC and DPD were observed statistically no significancy to predict systemic osteopenia. On DEXA measurement, in OVX group, we observed statistically significant decrease from 3rd week in distal metaphysis, statistically non-significant decrease from 2nd week in alveolar bone of mandible, and statistically significant decrease at 16th week in total mandible. From these results, it could be stated that systemic osteopenia by ovariectomy was early affected in the trabecular bone of femur and alveolar bone of the mandible whereas the total mandible was affected later.

In-line 마그네트론 스퍼터 장치를 사용하여 산소 분위기에서 제작한 Ag 박막의 특성

구대영,김원목,조상무,황만수,이인규,정병기,이택성,이경석,조성훈,Ku, Dae-Young,Kim, Won-Mok,Cho, Sang-Moo,Hwang, Man-Soo,Lee, In-Kyu,Cheong, Byung-Ki,Lee, Taek-Sung,Lee, Kyeong-Seok,Cho, Sung-Hun 한국재료학회 2002 한국재료학회지 Vol.12 No.8

A study was made to examine the electrical, compositional, structural and morphological properties of Ag thin films deposited by DC magnetron sputtering in $O_2$ atmosphere with deposition temperature from room temperature to 15$0^{\circ}C$ using in-line sputter system. The Ag films deposited at temperature above $100^{\circ}C$ in oxygen atmosphere gave a similar specific resistivity to and even lower oxygen content than those deposited using pure Ar sputter gas The Ag films deposited with pure Ar gas was mainly composed of crystallites with [111] preferred orientation, while, for those deposited in oxygen atmosphere, more than 50% of the volume was composed of crystallites with [100] orientation. The difference in the micro structure did not cause any difference in the specific resistivity of Ag films. The results showed that the transparent conducting oxide films and the Ag films could be processed sequentially in the same deposition chamber with careful control of deposition temperature, which might result in a cost reduction for constructing the large scale in-line deposition system.

백서에서 Depulpin®과 Formocresol에 대한 치수와 치근단 조직의 반응

문형인,김선호,황윤찬,오병주,황인남,김선헌,정선와,윤창,오원만 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.4

One fifth dilution of formocresol is usually for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However, the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it may also alter the pulp tissue rendering it immumologically active, and have carcinogenic potential. Recently Depulpin®(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49% paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier. But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine. Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue, in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present. it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin® group The area of necrotic tissue which had no cells and fibers , was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nucleli. A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resorption and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall. was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.

Early Percutaneous Catheter Drainage Reduces Hospital Stay but Not Mortality in Patients with Pyogenic Liver Abscess

( Chang Hun Lee ),( Yun Chae Lee ),( Jaehee Park ),( Song Yi Yu ),( Hun Gil Jo ),( Jae Sun Song ),( Gum Mo Jung ),( Yong Keun Cho ),( Eun Young Cho ),( In Hee Kim ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: To investigate the factors associated with prolonged hospital stay and mortality among patients with pyogenic liver abscess (PLA) who underwent percutaneous drainage (PCD). Methods: We retrospectively reviewed data from PLA patients admitted from 2005 to 2018 at three tertiary hospitals in Jeonbuk province. We selected patients who underwent PCD during the admission period and early PCD was defined whether the procedure was done within 3 days of admission. Results: Among 655 patients diagnosed with PLA, 366 patients who underwent PCD were enrolled for the study. The patients had a mean age of 65.5 ± 14.7 years, and mean maximal diameter of the hepatic abscess was 6.1 ± 2.6 cm and 71.9% of the lesion was single. Next, two groups were divided depending on the time period of PCD and 269 patients (73.5%) underwent PCD within 3 days of hospitalization. In baseline characteristics, early PCD group was significantly higher in the number of abscess as well as the maximal abscess diameter. However, hospitalization period was significantly lower in the early PCD group though in-hospital mortality was not different. We checked laboratory results at 1 week after the admission and CRP levels were significantly lower in the early PCD group. We further analyzed the factors related to the long-term hospitalization more than 14 days. In multivariate analysis, underlying diabetes, lower albumin levels, and PCD inserted after 3 days of admission were independent factors associated with prolonged hospital stay. Conclusions: Early PCD facilitated improvement of inflammatory laboratory markers and shortened the hospital stay. Early PCD may be beneficial in patients with PLA.

췌담관 합류이상이 있는 환자에서 담도계 손상 기전에 대한 연구

정인호,정용식,김지훈,최수윤,김정운,김욱환,홍정,왕희정,유병무,김진홍,한재호,김영배,김재근,김명욱 한국간담췌외과학회 2003 한국간담췌외과학회지 Vol.7 No.2

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1997)

김재홍,문득곤,김정수,김용준,임동진,박상훈,김희성,이민수,송기훈,김갑형,김형석,성소영,이인섭,김석우,황지환,조창근,김경문,부태성 대한화학요법학회 2000 대한화학요법학회지 Vol.18 No.3

Background : In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. Objective & Methods : For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1997. 99 strains of N. gonorrhoeae were isolated, among which 45(45.5%) were PPNG. Conclusion : The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 45.5% in 1997.