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>

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.

Effect of Storage Condition on Yield and Quality of Angelica acutiloba Radix

Choi,Seong-kyu,Yun,Kyeong-Won,Chon,Sang-Uk,Seo,Young-nam 한국자원식물학회 2002 Plant Resources Vol.5 No.1

To develop an optimal storage method of root of Angelica acutiloba Radix, which has been grown as major herbal medicine material to be cultivated, root of Angelica acutiloba Radix, was stored for 10 months with different packing materials and sealing methods. The loss in dry weight as influenced by packing materials and sealing methods was the lowest at vacuum packing and followed by complete sealing methods with transparent polyethylene film. The ratio of root rot during the storage period was not significantly different between packing materials but was significantly different between sealing conditions. In conclusion, vacuum packing and complete sealing with polyethylene film appears to be most optimal for storage of Angelica acutiloba Radix.

Volatile Flavor Components in Boiled Snow Crab (Chionoecetes japonicus) and Its Concentrated Cooker Effluent

Sung-Hee Choi,Young-Man Kim,Sook-Kyung Hyun 한국식품영양과학회 2001 Preventive Nutrition and Food Science Vol.6 No.2

The volatile flavor components of snow crabs from the Young-duk coast of Korea and their concentrated cooker effluent were isolated by a modified method from Likens and Nickerson, using a simultaneous distillation and extraction apparatus. The concentrated extract was analyzed and identified by gas chromatography and GC-MS. The flavor profile of boiled crab demonstrated that the favorable flavor characteristic of crab involved a seafood-like note, and that of concentrated cooker effluent demonstrated that the weak boiled crab flavor involved a fishy note. The main flavor components of boiled crab were heterocyclic compounds including alkylpyrazines, thizoles and thiolanes, aliphatic ketones including 2-heptanone and nonanone. On the other hand, the main flavor components of cooker effluent were aldehydes including 3-methylbutanal, alipatic ketones including 2-heptanone and alkanes including 2,6,10,14-tetramethyl-pentadecane. Almost all of heterocyclic compounds, which seem to be important contributors to the flavor of boiled crab, were not identified in concentrated cooker effluent. As a result, there may be a need to add the crab flavor components formed through model experiments of Maillard reactions to the concentrated cooker effluent for human consumption.

Effect of Activated Charcoal on Growth of Zingiber mioga ROSC

Choi,Seong-Kyu,Yun,Kyeong-Won,Chon,Sang-Uk,Seo,Young-Nam,Seo,Kyoung-Sun,Kwon,Byung-Sun 한국자원식물학회 2004 Plant Resources Vol.7 No.2

Activate charcoal (AC) can be utilized as a soil conditioner in agricultural crop areas. This study was conducted to investigate the effect of AC on growth and yield of Zingiber mioga ROSC as affected by different amounts of AC. The results obtained are summarized as follows. Growth characteristics including plant height and leaf length were the highest when activated charcoal added with 10-30%, suggesting that optimum amount of activated charcoal was ranged from 10 to 30%. Growth and enlargement of the root were improved by 10% AC with higher rhizome length and weight.

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.

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.

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.

Study on Leaf Production of Angelica acutiloba by Mulching with Polyethylene Film

Choi,Seong-Kyu,Yun,Kyeong-Won,Chon,Sang-Uk,Seo,Young-Nam,Seo,Kyoung-sun,Kwon,Byung-Sun 한국자원식물학회 2003 Plant Resources Vol.6 No.3

This study was conducted to produce effectively more leaves of Angelica acutiloba through year-round production system by using various mulching materials and polyethylene(PE) tunnel. Soil temperature by covering treatment was higher in PE mulching and PE tunnel than in rice straw mulching, especially showing the highest temperature in PE tunnel from April through May. Water content of soil was higher in PE mulching than in non-mulching. Leaf production of Angelica acutiloba through year-round production showed the highest in PE tunnel and root production in PE mulching. These results suggest that leaf production of Angelica acutiloba can be maximized through PE tunnel cultivation system.