• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.734-740
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• 2005

The blood samples were collected from dairy cows at the same milking stage. The single-strand conformation polymorphism (PCR-SSCP) method was used to analyze for polymorphism at the 5'flanking region of the hsp70 gene. The mRNA expression levels of HSP70, HSF1, Bcl-2 and Bax-$\alpha$ at different daily-mean-temperature were analyzed by relative quantitative RTPCR. The DNA content, cell phase and the ratio of apoptosis of lymphocytes in peripheral blood of dairy cattle at different daily-meantemperature were determined by FCM. The PCR-SSCP products of primer pair 1 showed polymorphisms and could be divided into four genotypes: aa, ab, ac, cc, with the cis-acting element (CCAAT box) included. Mutations in the hsp70 5'flanking region (468-752 bp) had different effects on mRNA expression of HSP70, HSF1, Bcl-2 and Bax-$\alpha$. The ac genotypic cows showed higher expressions of HSP70mRNA, HSF1mRNA and Bcl-2mRNA/Bax-$\alpha$mRNA and lower ratio of apoptosis. These mutation sites can be used as molecular genetic markers to assist selection for anti-heat stress cows.

• Journal of Korean Library and Information Science Society
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• v.46 no.2
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• pp.29-48
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• 2015

The aim of this study is to analyze the functional ego state of public librarians who should take a role of an information intermediary for children and young adults through the ego-gram which is suggested in transactional analysis theory and review their limit and feasibility as instructors. As a result of analysis, the whole ego state type of public librarians is founded to be N-type(Nightingale type) like NP-AC-A-CP-FC. The characteristics of this type can be interpreted as 'to show the tendency of self-denial in spite of their dedication.' So, the public librarians have to do their best to develop A(Adult), CP(Critical Parent) and FC(Free Child) ego state to take the requirements and behaviors of children and young adults in nurturing attitudes and enhance their autonomy and creativity through active mutual interaction. Improving A and FC is also very helpful to decrease their stress and raise their job satisfaction.

• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.149-154
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• 1996

ZnO and Al-doped ZnO thin films were prepared by sol-gel dip-coating method and electrical and optical properties of films were investigated. Using the zinc acetate dihydrate and acetylaceton(AcAc) as a chelating agent stable ZnO sol was synthesized with HCl catalyst. Adding aluminium chloride to the ZnO sol Al-doped ZnO sol could be also synthesized. As Al contents increase the crystallinity of ZnO thin film was retarded by increased compressive stress in the film resulted from the difference of ionic radius between Zn2+ and Al3+ The thickness of ZnO and Al-doped ZnO thin film was in the range of 2100~2350$\AA$. The resistivity of ZnO thin films was measured by Van der Pauw method. ZnO and Al-doped ZnO thin films with annealing temperature and Al content had the resistivity of 0.78~1.65$\Omega$cm and ZnO and Al-doped ZnO thin film post-annealed at 40$0^{\circ}C$ in vacuum(5$\times$10-5 torr) showed the resistivity of 2.28$\times$10-2$\Omega$cm. And the trans-mittance of ZnO and Al-doped ZnO thin film is in the range of 91-97% in visible range.

• Journal of Digital Convergence
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• v.17 no.12
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• pp.413-425
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• 2019

This study was conducted to identify factors affecting depression in junior nursing students(JNS). The number of the participants was 144 at a college in S and G city. The data were collected using questionnaires about somatic symptoms(SS), sleep quality, stress, adaptation to college life(AC), depression. Mean score of depression was 18.89, 58.3% are experiencing depression that requires clinical treatment. The significant predictors of JNS were levels of depression AC(β=-.503, p=.000) and SS(β=.263, p=.000) respectively, explaining 58.9% of variance. In order to control the depressive symptoms of JNS, it is necessary to diagnose basic learning ability from the beginning of admission and provide guidance management plans to help students adapt to academic activities by providing customized programs for each level to improve learning ability. It is necessary to develop and apply various intervention programs to alleviate physical symptoms such as fatigue/low energy experienced by JNS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.685-688
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• 2005

An efficient sustain driver and a useful reset circuit composition technique are proposed for plasma display panel drive. The proposed sustain driver uses a series resonance between an external inductor and a panel to recover the energy dissipated by a capacitive displacement current of PDP. It consists of four switching devices, an inductor, and external capacitors, which supply sustain voltage sources. Although the amplitude of an input voltage source is twice as high as that of conventional sustain drivers, average voltage stress imposed on power switching devices is nearly same in their values. Moreover, the input voltage source can be directly applied for the use of a reset voltage source. Owing to this scheme, the proposed sustain driver and the embedded reset circuit have a simple configuration. The operational principle and design example are given with theoretical analyses. The validity of the proposed drive system is verified through experiments using a prototype equipped with a 7.5-inch-diagonal AC plasma display panel.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1234-1236
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• 2005

High temperature superconducting(HTS) windings for an HTS transformer which have been developed have two kinds of type, one is the layer type and the other is disk type. The disk type windings have advantages over the layer type ones for a power transformer such as good insulation and limit of voltage stress. But this kind of HTS winding generates excessive AC losses caused by strong magnetic field component perpendicular to the surface of the HTS wire. Nevertheless, the layer type windings have adopted for an HTS power transformer so far because of the small AC losses of the HTS windings. We propose a new winding method for a high voltage HTS transformer which has advantages of both type of HTS windings, and we call it continuous disk type HTS winding. This new type of HTS winding consists of pile of lots of HTS disk windings which have no resistive joint between them. A prototype of an HTS winding was fabricated by the new winding method we proposed and characteristic test was carried out. The test result shows that the new type HTS windings can be applied to HTS power transformers, especially to the high voltage ones.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.143-149
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• 2022

PCS needs to freely switch AC and DC to connect the battery, external AC loads and renewable energy in both directions for energy efficiency. Whenever converting happens, power loss inevitably occurs. Minimization of the power loss to save electricity and convert it for usage is a very critical function in PCS. PCS plays an important role in the ESS(Energy Storage System) but the importance of stabilizing semiconductors on PCB(Printed Circuit Board) should be empathized with a risk of failure such as a fire explosion. In this study, the temperature variation inside PCS was reviewed by cooling fan on top of PCS, and the vibration characteristics of PCS were analyzed during truck transportation for reliability of the product. In most cases, a cooling fan is mounted to control the inner temperature at the upper part of the PCS and components generating the heat placed on the internal aluminum cooling plate to apply the primary cooling and the secondary cooling system with inlet fans for the external air. Results of CFD showed slightly lack of circulating capacity but simulated temperatures were durable for components. The resonance points of PCS were various due to the complexity of components. Although they were less than 40 Hz which mostly occurs breakage, it was analyzed that the vibration displacement in the resonance frequency band was very insufficient. As a result of random-vibration simulation, the lower part was analyzed as the stress-concentrated point but no breakage was shown. The steel sheet could be stable for now, but for long-term domestic transportation, structural coupling may occur due to accumulation of fatigue strength. After the test completed, output voltage of the product had lost so that extra packaging such as bubble wrap should be considered.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.545-551
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• 2017

Curcuma longa L. (CL) is widely used as a spice and coloring agent in several foods, such as curry and mustard, as well as cosmetics and drugs. In this study, we investigated the protective effects of CL extracted with various solvents [methanol (MC), ethanol (EC), acetone (AC)] on $H_2O_2-induced$ DNA damage in human leukocytes along with total polyphenol contents (TPC) and antioxidant properties. The antioxidant effects of CL were determined by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA) and superoxide dismutase (SOD)-like activity. The preventive effect of CL on oxidative stress-induced DNA damage and DNA repair capacities were assessed using comet assay. MC showed the highest TPC (11.17 g gallic acid equivalents/100 g) and antioxidant properties among the solvent extracts. The $SC_{50}$ for DPPH RSA was MC: 35.0 > AC: 45.8 > EC: $57.8{\mu}g/mL$ and SOD-like activity was MC: 46.6 > EC: 141.5 > AC: $296.4{\mu}g/mL$. In the comet assay, the $ED_{50}$ value of MC showed the highest inhibition ($86.7{\mu}g/mL$) of $H_2O_2-induced$ DNA damage, followed by AC ($110.0{\mu}g/mL$) > EC ($115.8{\mu}g/mL$). Analysis of the percentage of damaged cells showed that repair capacity significantly decreased at 4, 8, and 12 h from $H_2O_2-induced$ oxidative stress in each extract. After 12 h, level of DNA damage recovery was similar to the negative control level. These results suggest that CL has potential antioxidant activity and a protective effect against oxidation-induced DNA damage, and the methanol extract of CL was the most effective.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.626-632
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• 2005

The polyamines are essential components of all eukaryotic cells and absolutely necessary for cell growth. In the present study, the cytoprotective role of polyamine was characterized. When $Ac_2F$ rat liver cells were treated with 1M 2,2'-azobis (2-amidinopropane) dehydrochloride (AAPH), a water soluble free radical initiator, viability of the cells was noticeably decreased due to the increase of reactive oxygen species (ROS). The cytotoxic effect of AAPH as well as ROS generation were significantly inhibited by the treatment of polyamines. Among polyamines, especially spermine at $20{\mu}M$ concentration exerted over $45\%$ inhibition of AAPH-induced ROS generation. Western blotting was performed to determine whether superoxide dismutase(SOD) or catalase (CAT) expression was involved in oxidative stress. The AAPH treatment blocked both SOD and CAT protein expressions. Spermine could recover those protein expressions to the untreated control levels. According to the result of cycline E measurement, AAPH might block the entry of the cells into S phase of the cell cycle. The reduced expression of cyclin E protein could be fully recovered by the addition of spermine. The antioxidative effects of spermine was also further proved by the apopotitic morphological analysis using ethidium bromide and acridine orange.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.127-127
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• 2017

Aluminum is the most abundant metallic element in the Earth's crust and considered as the most limiting factor for plant productivity in acidic soils. The inhibition of root growth is recognized as the primary effect of Al toxicity. Seeds of wheat cv. Keumkang (Korean cultivar) were germinated on petridish for 5 days and then transferred hydroponic apparatus which was treated with $0{\mu}M$ $AlCl_3$ (control), $100{\mu}M$ $AlCl_3$ and $150{\mu}M$ $AlCl_3$ for 5 days. The length of roots, shoots and fresh weight of wheat seedlings were decreased under aluminum stress. The concentrations of $K^+$, $Mg^{2+}$ and $Ac^{2+}$ were decreased whereas $Al^{3+}$ and $P_2O_5{^-}$ concentration was increased under aluminum stress. Using confocal microscopy, the fluorescence intensity of aluminum was increased with morin staining. In this study, a proteome analysis was performed to identify proteins, which is responsible to aluminum stress in wheat roots. In 10-day-old seedlings, proteins were extracted from roots and separated by 2-DE, stained by CBB. Using image analysis, a total of 47 differentially expressed protein spots were selected, whereas 19 protein spots were significantly up-regulated such as s-adenosylmethionine, oxalate oxidase, malate dehydrogenase, cysteine synthase, ascorbate peroxidase and 28 protein spots were significantly down-regulated such as heat shock protein 70, o-methytransferase 4, enolase, amylogenin by aluminum stress following protein spots analyzed by LTQ-FTICR mass spectrometry. The results provide the global picture of Al toxicity-induced alterations of protein profiles in wheat roots, and identify the Al toxicity-responsive proteins related to various biological processes that may provide some novel clues about plant Al tolerance.