• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.406-406
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• 2016

To get high efficiency n-type crystalline silicon solar cells, passivation is one of the key factor. Tunnel oxide (SiO2) reduce surface recombination as a passivation layer and it does not constrict the majority carrier flow. In this work, the passivation quality enhanced by different chemical solution such as HNO3, H2SO4:H2O2 and DI-water to make thin tunnel oxide layer on n-type crystalline silicon wafer and changes of characteristics by subsequent annealing process and firing process after phosphorus doped amorphous silicon (a-Si:H) deposition. The tunneling of carrier through oxide layer is checked through I-V measurement when the voltage is from -1 V to 1 V and interface state density also be calculated about $1{\times}1012cm-2eV-1$ using MIS (Metal-Insulator-Semiconductor) structure . Tunnel oxide produced by 68 wt% HNO3 for 5 min on $100^{\circ}C$, H2SO4:H2O2 for 5 min on $100^{\circ}C$ and DI-water for 60 min on $95^{\circ}C$. The oxide layer is measured thickness about 1.4~2.2 nm by spectral ellipsometry (SE) and properties as passivation layer by QSSPC (Quasi-Steady-state Photo Conductance). Tunnel oxide layer is capped with phosphorus doped amorphous silicon on both sides and additional annealing process improve lifetime from $3.25{\mu}s$ to $397{\mu}s$ and implied Voc from 544 mV to 690 mV after P-doped a-Si deposition, respectively. It will be expected that amorphous silicon is changed to poly silicon phase. Furthermore, lifetime and implied Voc were recovered by forming gas annealing (FGA) after firing process from $192{\mu}s$ to $786{\mu}s$. It is shown that the tunnel oxide layer is thermally stable.

• Journal of Physiology & Pathology in Korean Medicine
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• v.33 no.2
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• pp.102-108
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• 2019

This study aims to evaluate the anti-inflammatory effect of Coptidis Rhizoma (CR) extract for atopic dermatitis through maintaining skin barrier and regulating Th2 cell differentiation. We divided NC/Nga mice into 3 groups as follows; atopy-like dermatitis induced group with CR treatment (CT, n=10), no treatment group(Ctrl), atopy-like dermatitis elicited group(AE). Atopy-like dermatitis was induced to NC/Nga mice by sensitizing with dermatophagoides farinae(DfE) on 7, 8, 9, 11, 12, and 13th week. After inducing atopic dermatitis, CR extract was administered 20 mg/kg daily for the experimental duration to the CT group. We measured the integrity of lipid layers in the epidermis and Th2 differentiation through immunohistochemical staining against filaggrin, loricrin, IL-4, and IL-13. We also measured the distribution of subcutaneous collagen fibers by the Masson's trichrome staining. Administration of CR significantly inhibited the reduction of lipid layers in the skin that caused atopy. The expression of IL-4, IL-13, each of which is a cytokine secreted by T helper type 2 (Th2) cells, was markedly suppressed in the CT group as compared with AE group (p<0.05). CR treatment also decreased the expression of iNOS, $p-I{\kappa}B$. Atopic dermatitis induced dermatological damage to skin, such as hyperplasia of epithelium, and capillary proliferation was significantly reduced by CR administration. CR effectively inhibited the thinning of the skin barrier and inflammatory responses in atopic dermatitis-induced mice. In particular, it showed anti-inflammatory effects by reducing the expression of IL-4 and IL-13, Th2 cell cytokines, which play a crucial role in development of atopic dermatitis. Therefore, CR can be a good candidate to ameliorate and treat atopic dermatitis.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.601-608
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• 1997

In order to search for the way to utilize rice hull as a renewable resource, the inhibition on ${\alpha}-glucosidase$ and the fractionation of rice hull extract was investigated. An ethanol extract of rice hull from Japonica-type rice seeds exhibited 30% inhibitory activity on rat intestinal brush border ${\alpha}-glucosidase$ (1.4 mU/mL) in vitro at the concentration of 0.8 mg/mL using 6 mM p-nitrophenyl ${\alpha}-D-glucopyranoside$ as a substrate $(IC_{50}\;162\;mg/mL)$. Among the fractions obtained by partitioning the ethanol extract successively with solvents, the ethyl acetate fraction at the concentration of 0.8 mg/mL was found to exhibit the most potent inhibitory activity i.e. 65% inhibition of ${\alpha}-glucosidase\;(IC_{50}\;0.14\;mg/mL)$. Silica gel column chromatography of the ethyl acetate fraction exhibited slightly higher (90%) inhibitory activity, and its subsequent fractionation by Sephadex LH-20 column chromatography did not improve inhibitory activity. Considering the inhibitory activity and yield, the ethyl acetate fraction obtained by the solvent-partitioning process would be a candidate for the hypoglycemic food if it has in vivo effectiveness.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.657-663
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• 2005

Collagenases are generally defined as enzymes that are capable of degrading the polypeptide backbone of native collagen under conditions that do not denature the protein. An extracellular collagenase-producing bacterial strain was isolated from kimchi and identified to be Bacillus subtilis JS-17 through morphological, cultural, biochemical characteristics and 16S rDNA sequence analysis. Optimum culture condition of Bacillus subtilis JS-17 for the production of collagenase was $1.5\%$ fructose, $1\%$ yeast extract, $0.5\%\;K_2HPO_4,\;0.4\%\;KH_2PO_4,\;0.01\%\;MgSO_4\cdot7H_2O,\;0.01\%\; MnSO_4\cdot4H_2O,\;,0.1\%$ citrate and $0.1\%\;CaCl_2$. The production of collagenase was optimal at $30^{\circ}C$ for 72 hr. A collagenase was isolated from the culture filtrate of Bacillus subtilis JS-17. The enzyme was purified using Amberlite IRA-900 column chromatography, Sephacryl S-300 HR column chromatography and DEAE-Sephadex A-50 column chromatography The purified collagenase has an specific activity 192.1 units/mg. The molecular weight of the purified enzyme was estimated to be 28 kDa by SDS-PACE. The purified collagenase has $100\%$ activity up to $55^{\circ}C$.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.468-478
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• 2004

It is essential in various application areas of data mining and bioinformatics to effectively retrieve the occurrences of interesting patterns from sequence databases. For example, let's consider a network event management system that records the types and timestamp values of events occurred in a specific network component(ex. router). The typical query to find out the temporal casual relationships among the network events is as fellows: 'Find all occurrences of CiscoDCDLinkUp that are fellowed by MLMStatusUP that are subsequently followed by TCPConnectionClose, under the constraint that the interval between the first two events is not larger than 20 seconds, and the interval between the first and third events is not larger than 40 secondsTCPConnectionClose. This paper proposes an indexing method that enables to efficiently answer such a query. Unlike the previous methods that rely on inefficient sequential scan methods or data structures not easily supported by DBMSs, the proposed method uses a multi-dimensional spatial index, which is proven to be efficient both in storage and search, to find the answers quickly without false dismissals. Given a sliding window W, the input to a multi-dimensional spatial index is a n-dimensional vector whose i-th element is the interval between the first event of W and the first occurrence of the event type Ei in W. Here, n is the number of event types that can be occurred in the system of interest. The problem of‘dimensionality curse’may happen when n is large. Therefore, we use the dimension selection or event type grouping to avoid this problem. The experimental results reveal that our proposed technique can be a few orders of magnitude faster than the sequential scan and ISO-Depth index methods.hods.

• Tuberculosis and Respiratory Diseases
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• v.61 no.4
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• pp.366-373
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• 2006

Background: Paraquat is extremely toxic chemical material, which generates reactive oxygen species (ROS), causing multiple organ failure. In particular, paraquat leads to irreversible progressive pulmonary fibrosis. Exaggerated cell deaths exceeding the normal repair of type II pneumocytes leads to mesenchymal cells proliferation and fibrosis. This study examined the followings; i) whether or not paraquat induces cell death in lung epithelial cells; ii) whether or not paraquat-induced cell deaths are apoptosis or necrosis; and iii) the effects of N-acetylcysteine, dexamethasone, and bcl-2 on paraquat-induced cell deaths. Methods: A549 and BEAS-2B lung epithelial cell lines were used. The cell viability and apoptosis were evalluated using a MTT assay, Annexin V staining was monitored by fluorescence microscopy, The level of bcl-2 inhibition was examined by establishing stable A549 pcDNA3-bcl-2 cell lines throung the transfection of pcDNA3-bcl-2 with the mock. Results: Paraquat decreased the cell viability in A549 and BEAS-2B cells in a dose and time dependent manner. The Annexin V assay showed that apoptosis was the type of paraquat-induced cell death. Paraquat-induced cell deaths was significantly inhibited by N-acetylcysteine, dexamethasone, and bcl-2 overexpression. The cell viability of A549 cells treated with N-acetylcysteine, and dexamethasone on the paraquat-induced cell deaths were increased significantly by 10 ~ 20%, particularly at high doses. In addition, the cell viability of A549 pcDNA3-bcl-2 cells overexpressing bcl-2 was significantly higher than the untransfected A549 cells. Conclusion: Paraquat induces apoptotic cell deaths in lung epithelial cells in a dose and time dependent manner. The paraquat-induced apoptosis of lung epithelial cells might occur through the mitochondrial pathway.

• Journal of The Korean Association For Science Education
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• v.25 no.4
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• pp.441-449
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• 2005

The purpose of this study was to examine the degree of cognitive conflict by learner personality and the method of presenting anomalous data to induce cognitive conflict. The participants of this study were 461 high school students. To arose cognitive conflict, an actual demonstration was done for half of the participants and a logical article for the rest. MBTI (Myers-Briggs Type Indicator) was used to find the learner personality types, and CCLT (Cognitive Conflict Level Test) was used to measure the degree of cognitive conflict aroused when anomalous data was confronted. The results of this study indicated that learner personality types influence the degree of cognitive conflict. First, participants were divided into two personality types via preferences on each of the four preference indices; extraversion (E) or introversion (I), sensing (S) or intuition (N), thinking (T) or feeling (F), judgment (J) or perception (P). The cognitive conflict scores of the thinking types were significantly higher than those of the feeling types. Participants were also divided four personality types according to personality functional types: ST, SF, NT and NF. SF type showed a significantly lower cognitive conflict score than any of the other types. According to the type of learner personality, cognitive conflict was influenced differently by the method of presenting anomalous data. For example, the judgment types had a higher cognitive conflict score by logical argument, and the perception types showed a higher score by demonstration. In conclusion, learner cognitive conflicts were influenced by personality types and the methods of presenting anomalous data.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.367-371
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• 2001

In this paper, theS $r_2$(T $a_{1-x}$ , N $b_{x}$)$_2$ $O_{7}$(STNO) films among ferroelectric materials having a low dielectric constant for metal-ferroelectric-semiconductor field effect transistor(MFS-FET) were discussed. The STNO thin films were deposited on p-type Si(100) at room temperature by co-sputtering with S $r_2$N $b_2$ $O_{7(SNO)}$ ceramic target and T $a_2$ $O_{5}$ ceramic target. The composition of STNO thin films was varied by adjusting the power ratios of SNO target and T $a_2$ $O_{5}$ target. The STNO films were annealed at 8$50^{\circ}C$, 90$0^{\circ}C$ and 9$50^{\circ}C$ temperature in oxygen ambient for 1 hour. The value of x has significantly influenced the structure and electrical properties of the STNO films. In the case of x= 0.4, the crystallinity of the STNO films annealed at 9$50^{\circ}C$ was observed well and the memory windows of the Pt/STNO/Si structure were 0.5-8.3 V at applied voltage of 3-9 V and leakage current density was 7.9$\times$10$_{08}$A/$\textrm{cm}^2$ at applied voltage of -5V.of -5V.V.V.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.285-286
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• 2012

We combine data from two all-sky surveys, the Swift/Burst Alert Telescope 22 Month Source Catalog and the AKARI Point Source Catalogue, in order to study the connection between the hard X-ray (> 10 keV) and infrared (IR) properties of local active galactic nuclei (AGN). We find two photometric diagnostics are useful for source classification: one is the X-ray luminosity vs. IR color diagram, in which type 1 radio-loud AGN are well isolated from other AGN. The second one uses the X-ray vs. IR color-color diagram as a redshift-independent indicator for identifying Compton-thick (CT) AGN. Importantly, CT AGN and starburst galaxies in composite systems can also be separated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new surveys such as with WISE and NuSTAR.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1329-1333
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• 2004

To isolate the microsatellites from the chromosomal DNA of the Korean cattle (Hanwoo) and to use those for the genetic selection, four bacteriophage genomic libraries containing the chromosomal DNA of six Hanwoo steers showing the differences in meat quality and quantity were used. Screening of the genomic libraries using $^{32}P-radiolabeled 5'-({CA})_{12}-3$nucleotide as a probe, resulted in isolation of about 3,000 positive candidate bacteriophage clones that contain $(CA)_n$-type dinucleotide microsatellites. After confirming the presence of microsatellite in each positive candidate clone by Southern blot analysis, the DNA fragments that include microsatellite and flanking sequences possessing less than 2 kb in size, were subcloned into plasmid vector. Results from the analysis of microsatellite length polymorphism, using twenty-two PCR primers designed from flanking region of each microsatellite DNA, demonstrated that 208 and 210 alleles of HW-YU-MS#3 were closely related to the economic traits such as marbling score, daily gain, backfat thickness and M. longissimus dorsi area in Hanwoo. Interestingly, HW-YU-MS#3 microsatellite was localized in bovine chromosome 17 on which QTLs related to regulation of the body fat content and muscle ypertrophy locus are previously known to exist. Taken together, the results from the present study suggest the possible use of the two alleles as a DNA marker related to economic trait to select the Hanwoo in the future.