Nanogenerators: Fully Rollable Transparent Nanogenerators Based on Graphene Electrodes (Adv. Mater. 19/2010)

Choi, Dukhyun,Choi, Min-Yeol,Choi, Won Mook,Shin, Hyeon-Jin,Park, Hyun-Kyu,Seo, Ju-Seok,Park, Jongbong,Yoon, Seon-Mi,Chae, Seung Jin,Lee, Young Hee,Kim, Sang-Woo,Choi, Jae-Young,Lee, Sang Yoon,Kim, Jo WILEY-VCH Verlag 2010 ADVANCED MATERIALS Vol.22 No.19

<B>Graphic Abstract</B> <P>The cover shows an image of fully rollable transparent nanogenerators synthesized using chemical vapor deposition grown large-scale graphene sheets as transparent electrodes and piezoelectric ZnO nanorod arrays. Sang-Woo Kim, Jae-Young Choi, and co-workers report on p. 2187 the electrical and structural stability of the nanogenerators, with excellent charge scavenging performance under external mechanical loads such as bending and rolling. This study shows that graphene-based nanogenerators are very promising for self-powered rollable transparent device applications. <img src='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content.gif' alt='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content'> </P>

Comparison of trophic factors changes in the hippocampal CA1 region between the young and adult gerbil induced by transient cerebral ischemia.

Yan, Bing Chun,Park, Joon Ha,Kim, Sung Koo,Choi, Jung Hoon,Lee, Choong Hyun,Yoo, Ki-Yeon,Kwon, Young-Geun,Kim, Young-Myeong,Kim, Jong-Dai,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2012 Cellular and molecular neurobiology Vol.32 No.8

<P>In the present study, we investigated neuronal death/damage in the gerbil hippocampal CA1 region (CA1) and compared changes in some trophic factors, such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF), in the CA1 between the adult and young gerbils after 5 min of transient cerebral ischemia. Most of pyramidal neurons (89%) were damaged 4 days after ischemia-reperfusion (I-R) in the adult; however, in the young, about 59% of pyramidal neurons were damaged 7 days after I-R. The immunoreactivity and levels of BDNF and VEGF, not GDNF, in the CA1 of the normal young were lower than those in the normal adult. Four days after I-R in the adult group, the immunoreactivity and levels of BDNF and VEGF were distinctively decreased, and the immunoreactivity and level of GDNF were increased. However, in the young group, all of their immunoreactivities and levels were much higher than those in the normal young group. From 7 days after I-R, all the immunoreactivities and levels were apparently decreased compared to those of the normal adult and young. In brief, we confirmed our recent finding: more delayed and less neuronal death occurred in the young following I-R, and we newly found that the immunoreactivities of trophic factors, such as BDNF, GDNF, and VEGF, in the stratum pyramidale of the CA1 in the young gerbil were much higher than those in the adult gerbil 4 days after transient cerebral ischemia.</P>

Floristic characteristics of vascular plants and first distributional report of Pseudostellaria baekdusanensis M. Kim in Yongneup wetland protected area

Young-Chul Kim,Hyun-Hee Chae,Sang-Heock Oh,Seung-Ho Choi2,Moon-Pyo Hong3,Gi-Heum Nam,Jae-Yoon Choi,Hyun-Sook Choi,Kyu-Song Lee 한국환경생태학회 2015 한국환경생태학회지 Vol.29 No.2

Yongneup wetland protected area, the only high moor in Korea, is a core area to conserve biodiversity. Even though the Yongneup wetland protected area is relatively small, various plant species are distributed in the Yongneup wetland protected area because it includes various habitats showing different environmental gradients. Vascular plants distributed in the Yongneup wetland protected area were identified as a total of 376 taxa that is composed of 73 families, 217 genera, 322 species, 3 subspecies, 44 varieties and 7 forms. For endangered plants designated by the Ministry of Environment, 5 species including Trientalis europaea var. arctica, Lilium dauricum, Halenia corniculata, Lychnis wilfordii and Menyanthes trifoliata were found and 34 taxa were confirmed to be distributed only in the mountainous wetland habitats. Regarding naturalized plants, a total of 11 taxa were distributed, but most of them were distributed in the areas where artificial interference has occurred. And in areas inside the wetlands that are relatively well preserved, 2 species of Bidens frondosa and Erigeron annuus were observed. In this study, the occurrence and distribution of Pseudostellaria baekdusanensis M. Kim, which was recently found in Mt. Baekdu and reported as a new species, were identified in the Yongneup wetland protected area. A wetland is a very vulnerable area to drastic environmental changes and damages to its ecosystem could cause the extinction of rare plant species which are distributed only in the wetlands. Therefore, it is mandatory that current status of the Yongneup wetland protected area is evaluated and actions to prevent rapid environmental changes are taken. Fourteen separate investigations were conducted in 2013 and another four in 2014, to evaluate current status of the Yongneup wetland protected area. These investigations have provided us the basic information for future actions of conservation and restoration.

AN IN-SITU YOUNG'S MODULUS MEASUREMENT TECHNIQUE FOR NUCLEAR POWER PLANTS USING TIME-FREQUENCY ANALYSIS

Choi, Young-Chul,Yoon, Doo-Byung,Park, Jin-Ho,Kwon, Hyun-Sang Korean Nuclear Society 2009 Nuclear Engineering and Technology Vol.41 No.3

Elastic wave is one of the most useful tools for non-destructive tests in nuclear power plants. Since the elastic properties are indispensable for analyzing the behaviors of elastic waves, they should be predetermined within an acceptable accuracy. Nuclear power plants are exposed to harsh environmental conditions and hence the structures are degraded. It means that the Young's modulus becomes unreliable and in-situ measurement of Young's modulus is required from an engineering point of view. Young's modulus is estimated from the group velocity of propagating waves. Because the flexural wave of a plate is inherently dispersive, the group velocity is not clearly evaluated in temporal signal analysis. In order to overcome such ambiguity in estimation of group velocity, Wigner-Ville distribution as the time-frequency analysis technique was proposed and utilized. To verify the proposed method, experiments for steel and acryl plates were performed with accelerometers. The results show good estimation of the Young's modulus of two plates.

Risk of Traumatic Intracranial Hemorrhage From Low-Energy Falls in the Oldest-Old Patients

Sung Kyu Kim,Ki Young Jeong,이종석,Han Sung Choi,홍훈표,고영관 대한노인병학회 2016 Annals of geriatric medicine and research Vol.20 No.4

Background: The population of individuals classified as oldest-old (aged ≥85 years) has increased rapidly in recent years. The rates of morbidity from chronic diseases and physical dependence tend to be higher in the oldest-old compared with individuals classified as young-to-middle-old (aged 65-84 years). Therefore, the classification and evaluation of traumatic injuries in the oldest-old group are necessary. Herein we focused on the risk of traumatic intracranial hemorrhage from low-energy falls in older patients. Methods: Patient medical records from the Emergency Department after low-energy falls that occurred between November 2014 and April 2016 were retrospectively analyzed. Patients were divided into an older group (aged ≥65 years) and an adult group (aged 18-64 years); the older group was subdivided into the oldest-old group (aged ≥85 years) and a young-to-middle-old group (aged 65-84 years). The rate of intracranial hemorrhage and related factors were also investigated. Results: The older group had a greater risk of traumatic intracranial hemorrhage than the adult group (20% vs. 12.6%, p=0.019). Furthermore, more cases of traumatic intracranial hemorrhage were found in the oldest-old group than in the young-to-middle-old group (37.5% vs. 18.0%, p=0.024). Similarly, the risk of traumatic intracranial hemorrhage in the oldest-old was higher than in the young-to-middle-old group (p=0.032). Conclusion: The risk of traumatic intracranial hemorrhage from low-energy falls in the oldest-old patients was higher than in the young-to-middleold patients. Therefore, physicians need to pay particular attention to oldest-old patients, even to those with mental integrity and without neurological deficits.

A Basic Study on Leaf and Stem Production of Angelica acutiloba

Choi,Seong-Kyu,Yun,Kyeong-won,Chon,Sang-Uk,Lee,Jong-Ill,Seo,Young-Nam,Seo,Kyoung-Sun,Choi,Kyeong-Ju 한국자원식물학회 2004 Plant Resources Vol.7 No.3

This study was conducted to develop effective production system in greenhouse for leaves and stems of Angelica acutiloba by using connect pots in 2003 and 2004. Seed germination rate and plant biomass of Angelica acutiloba collected in 2004 were higher than those harvested in 2003. Germination rate of Angelica acutiloba seeds collected in 2003 was 10%, while germination rate of seeds collected in 2004 was above 90%. Especially, plant growth and yield of Angelica acutiloba grown in connect pots sized with 4×4×5cm(length×width×height) were the highest. These results indicate that leaf and stem production of Angelica acutiloba can be improved by using connect pots and optimizing seed collecting time in greenhouse.

정보기술 계열학과와 비계열학과의 인터넷 중독 대학생에 있어서 충동성과 강박성 및 우울의 정도 비교

최상헌(Sang-Heon Choi),김민정(Min-Jeong Kim),정영인(Young-In Chung) 대한사회정신의학회 2004 사회정신의학 Vol.9 No.1

목 적: 본 연구의 목적은 인터넷 중독 대학생의 인터넷의 사용양상과 인격적 특성이 정보기술(IT) 계열학과와 비계열학과 간에 차이가 있는지를 알아보는 데 있다. 방 법: 부산광역시의 한 전문대학에서 IT 계열학과 146명과 비계열학과 140명의 남학생들을 대상으로 인터넷 사용과 관련된 일반적 특성과 인격적 특성을 조사하였다. 인터넷 중독 여부는 Young의 인터넷중독척도, 충동성은 한국판 Eysenck Personality Scale의 충동성검사, 강박성은 한국판 Maudsley Obsessive-Compulsive Inventory, 그리고 우울의 정도는 Beck Depression Inventory를 이용하여 측정하였다. 결 과: 1) 인터넷 중독율은 IT 계열학과에서 25.3%, 비계열학과에서 25.7%였다. 2) 인터넷 중독자에서 IT 계열학과에서 비계열학 과에 비해 교우관계가 더 양호하였고, 인터넷의 일일 사용시간이 더 많았다. 3) 인터넷 중독자에서 IT 계열학과에서 비계열학과에 비해 충동성 정도는 낮았으나, 강박성과 우울 정도는 차이가 없었다. 결 론: 본 연구결과는 인터넷 사용자의 인격적 특성이나 인터넷의 사용양상이 인터넷 사용자의 사회환경적 특성에 따라 인터넷 중독에 미치는 영향이 다를 수 있음을 시사한다. Objectives:This study aimed to investigate the differences of internet-use pattern and personality characteristics between internet-addicted college students of Information Technology(IT)-related departments and non-IT-related departments. Methods:286 male college students who were divided into 146 students of IT-related departments and 140 students of non-IT-related departments completed a checklist containing questionnaires designed by authors, Young’s Internet Addiction Test, Impulsiveness Questionnaire of Eysenck Personality Scale, Maudsley Obsessive-Compulsive Inventory, and Beck Depression Inventory. Results:1) The rate of internet addicts of IT-related and non-IT-related departments were 25.3% and 25.7%, respectively. 2) The internet addicts of IT-related departments had less problems of peer relationship and spent more time in the daily internet-use compared with those of non-IT-related departments. 3) The internet addicts of IT-related departments showed lower levels of impulsiveness compared with those of non-IT-related departments, but there were no differences in levels of obsessive-compulsiveness and depression between the two groups. Conclusion:These results suggest that the effects of personality characteristics and internet-use pattern of internet user on internet addiction may be different depending on their socio-environmental factors.

노년기 주관적 연령과 건강노화와의 관계: 연령집단별 분석

최은영 ( Choi Eun Young ),조성은 ( Cho Sung Eun ),오영삼 ( Oh Young Sam ),장희수 ( Chang Hee Su ),김영선 ( Kim Young Sun ) 한국보건사회연구원 2017 保健社會硏究 Vol.37 No.1

본 연구의 목적은 노년기 주관적 연령(스스로를 노인 혹은 비(非)노인으로 인지하는지 여부)과 건강노화와의 관계를 연령집단에 따라 검증하는 것이다. 이를 위해 2014년 노인실태조사 대상자 중 연소노인(65~74세)과 고령노인(75~84세)을 연구대상으로 선정하였다. 연구의 주목적인 주관적 연령과 건강노화 간의 관련성을 검증하기 위해 연소노인 및 고령노인 집단별로 다중회귀분석(multiple regression analysis)을 실시하였다. 연구결과, 주관적 연령과 건강노화의 관계는 연령집단별로 다른 양상을 보이는 것으로 나타났다. 연소노인에서 주관적 연령이 비(非)노인인 경우, 높은 수준의 인지기능과 적은 만성질환 수, 낮은 수준의 우울, 그리고 높은 수준의 사회활동 참여를 보이는 것으로 밝혀졌다. 반면, 고령노인인 경우 주관적 연령은 인지기능을 제외하고 건강노화의 다른 세 요소와 유의미한 관련이 없었다. 본 연구는 주관적 연령을 건강노화의 새로운 고려요소로 제시하여, 두 요소의 관련성을 통합적인 차원에서 살펴보았다는 의의가 있다. 또한 노인을 연령대에 따라 구별된 집단으로 살펴봄으로써, 주관적 연령과 건강노화의 연관성이 연령집단마다 상이한 양상을 보임을 밝혔다는 의의를 가진다. The purpose of this study is to examine the relationship between subjective age (whether one subjectively perceives himself as `the elderly` or `not the elderly`) and healthy aging. Using data from the 2014 National Elderly Survey (KIHASA), this study selected a total of 9,653 participants consisting of young-olds (aged 65-74) and old-olds (aged 75-84) For both the young-old and the old-old, multiple regression analyses were conducted to examine the research model. In the young-old population, one`s considering oneself as “non-elderly” was significantly associated with higher cognitive functioning, fewer chronic diseases, lower depressive symptoms, and higher level of social engagement. On the other hand, in the old-old population, one`s considering oneself as “non-elderly” was associated only with higher cognitive functioning, and not with the other domains of healthy aging. The findings suggest that subjective age can be considered as an important predictors of older adults` healthy aging. These findings indicate that the association between subjective age and healthy aging has a different pattern depending on the age group.

崔致遠의 玄妙之道와 儒·仙思想

崔英成(Choi, Young-Sung) 한국고대사탐구학회 2011 한국고대사탐구 Vol.9 No.-

최치원은 경문왕의 비로 추정되는 ?鸞郞碑序?에서 우리나라에 風流라는 고유사상이 존재한다고 밝혔다. ‘풍류’에 대해 많은 학자들의 해석이 있어 왔지만, 신비적이고 추상적인 해석들이 주를 이루며 아직 정론이 없다. 이 글에서는 ‘풍류’, ‘玄妙之道’같은 개념에 대한 문헌적 근거를 찾는 데 역점을 두었다. ‘풍류’란 명칭이 최치원에 의해 부여된 것이고, 그것이 ‘遺風餘流(선대부터 내려온 기풍과 흐름)’를 줄여서 쓴 말임을 밝혔다. 또 ‘현묘’란 말은 노자 王弼의 주석에서 “같은 데서 나왔으면서도 명칭을 달리한다(同出而異名)”고 한 것에 근거함을 고증하였다. 이와 함께 우리의 故國인 君子國과 靑丘國에 仁思想과 柔樸思想의 뿌리가 있어 유교사상과 도가사상의 형성에 큰 영향을 끼쳤을 것이라고 밝힘으로써 ‘包含三敎’의 의미를 실증하고자 하였다. Chiwon Choi said that Epitaph of Nanrang, the epitaph of a tombstone assumed as the gravestone of King Gyeongmun, indicated that Korea had her own idea called Pungryu. Many scholars have translated Pungryu but there is not yet an argument fixed as a reasonable idea in such translations. In this study, therefore, I concentrated on finding out the literature base for such concepts as Pungryu and Tao of Hyeonmyo. Pungryu was named by Chiwon Choi. I have found out that it stands for Yupungyeoryu(遺風餘流: the spirit and stream coming from the former generation). I ascertained also that the word Hyeonmyo was based on Wang-pil’s annotation on Lao-tzu, “Their names are different although they have come from same source”. I, furthermore, found out that such old Korean countries as the Kingdom of Gunja and the Kingdom of Cheonggu had the roots of the Idea of Benevolence and the Idea of Yubak, which must have largely influenced the formation of the Idea of Confucianism and the Idea of Taoism. That was, I tried to circumstantiate the meaning of Pohamsamgyo(包含三敎: the Integrated Idea of Confucianism, Buddhism and Taoism).

백서의 복강내에 투여한 Mitomycin-C-Polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

송규상,강대영,최정목,노승무,정경수,오정연,김진향,양준목,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

To evaluate the in-vivo effects of mitomycin-C-polyglycolic acid composite(MMC-PGA) the disk: shaped composite were implanted into the peritoneal cavity of the Sprague-Dawley rats. The pathologic changes were examined at various time points up to 12 weeks. Initially the soft tissue around the inserted disks showed capillary congestion at 3 days. Inflammatory infiltrates with foreign body giant cells appeared from the 2nd week and reached peak response at 6-8 weeks. These reaction diminished prominently at 12 weeks. No specific pathologic change was found in the liver, the kidneys, and the heart. The above results suggest that the MMC-PGA composite can serve as a new device for intraperitoneal chemotherapy of various types of cancers.