α-Fe 기 Nd - Fe - B 급속응고합금의 자기특성

조용수(Y. S. Cha),김윤배(Y. B. Kim),박우식(W. S. Park),김희태(H. T. Kim),김창석(C. S. Kim),김택기(T. K. Kim) 한국자기학회 1994 韓國磁氣學會誌 Vol.4 No.2

The magnetic properties of Nd-Fe-B alloys of containing 4 at.% Nd have been studied for the development of new type rare-earth magnets. The amorphous phase of a melt-spun Nd₄Fe_(85.5)B_(10.5) alloy is transformed into the phases which have a small amount of Nd₂Fe₁₄B₁ in α-Fe matrix by annealing above their crystallization temperature. The addition of Mo, Nb, V or Cu to Nd₄Fe_(85.5)B_(10.5) alloy results in the reduction of grain size and the subsequent improvement of the coercivity. The coercivity of Nd₄Fe_(82)B_(10)M₃Cu₁(M = Mo, Nb, V) alloys increases in the order of M = V < Nb < Mo and shows the highest value of 2.7 kOe when M = Mo. On the other hand, the remanence of these alloys shows the opposite trend and the most improved value of 1.35 T is observed when M = V.

혈액검체로부터 분리된 황색포도구균의 독소유전자형 및 PFGE 분석

이영선,차정옥,정영희,최연화,양숙자,김홍빈,유재일,김봉수 국립보건연구원 2000 국립보건원보 Vol.37 No.-

Efficacy of HVT-IBD vector vaccine compared to attenuated live vaccine using in-ovo vaccination against a Korean very virulent IBDV in commercial broiler chickens

Roh, J.-H.,Kang, M.,Wei, B.,Yoon, R.-H.,Seo, H.-S.,Bahng, J.-Y.,Kwon, J.-T.,Cha, S.-Y.,Jang, H.-K. Elsevier 2016 Poultry science Vol.95 No.5

<P>The production performance, efficacy, and safety of two types of vaccines for infectious bursal disease virus (IBDV) were compared with in-ovo vaccination of Cobb 500 broiler chickens for gross and microscopic examination of the bursa of Fabricius, bursa/body weight (b/B) ratio, flow cytometry, and serologic response to Newcastle disease virus (NDV) vaccination. One vaccine was a recombinant HVT-IBD vector vaccine (HVT as for herpesvirus of turkeys) and the other was an intermediate plus live IBDV vaccine. A significant difference was detected at 21 d. Eight of 10 chickens that received the IBDV live vaccine had severe bursal lesions and a relatively low b/B ratio of 0.95, and an inhibited NDV vaccine response. On the other hand, the HVT-IBD vector vaccine resulted in mild bursal lesions and a b/B ratio of 1.89. Therefore, the live vaccine had lower safety than that of the HVT-IBD vector vaccine. To determine the protective efficacy, chickens were intraocularly challenged at 24 d. Eight of 10 chickens in the IBDV live vaccination group showed gross and histological lesions characterized by hemorrhage, cyst formation, lymphocytic depletion, and a decreased b/B ratio. In contrast, the HVT-IBD vector vaccinated chickens showed mild gross and histological lesions in three of 10 chickens with a b/B ratio of 1.36, which was similar to that of the unchallenged controls. Vaccinated chickens showed a significant increase in IBDV antibody titers, regardless of the type of vaccine used. In addition, significantly better broiler flock performance was observed with the HVT-IBD vector vaccine compared to that of the live vaccine. Our results revealed that the HVT-IBD vector vaccine could be used as an alternative vaccine to increase efficacy, and to have an improved safety profile compared with the IBDV live vaccine using in-ovo vaccination against the Korean very virulent IBDV in commercial broiler chickens.</P>

Role of conserved Met112 residue in the catalytic activity and stability of ketosteroid isomerase

Cha, H.J.,Jang, D.S.,Jeong, J.H.,Hong, B.H.,Yun, Y.S.,Shin, E.J.,Choi, K.Y. Elsevier Science 2016 Biochimica et biophysica acta. Proteins and proteo Vol.1864 No.10

<P>Ketosteroid isomerase (3-oxosteroid Delta(5)-Delta(4)-isomerase, KSI) from Pseudomonas putida catalyzes allylic rearrangement of the 5,6-double bond of Delta(5)-3-ketosteroid to 4,5-position by stereospecific intramolecular transfer of a proton. The active site of KSI is formed by several hydrophobic residues and three catalytic residues (Tyr14, Asp38, and Asp99). In this study, we investigated the role of a hydrophobic Met112 residue near the active site in the catalysis, steroid binding, and stability of KSI. Replacing Met112 with alanine (yields M112A) or leucine (M112L) decreased the k(cat) by 20- and 4-fold, respectively. Compared with the wild type (WT), M112A and M112L KSIs showed increased K-D values for equilenin, an intermediate analogue; these changes suggest that loss of packing at position 112 might lead to unfavorable steroid binding, thereby resulting in decreased catalytic activity. Furthermore, M112A and M112L mutations reduced melting temperature (T-m) by 6.4 degrees C and 2.5 degrees C, respectively. These changes suggest that favorable packing in the core is important for the maintenance of stability in KSI. The M112K mutation decreased k(cat) by 2000-fold, compared with the WT. In M112K KSI structure, a new salt bridge was formed between Asp38 and Lys112. This bridge could change the electrostatic potential of Asp38, and thereby contribute to the decreased catalytic activity. The M112K mutation also decreased the stability by reducing T-m by 4.1 degrees C. Our data suggest that the Met112 residue may contribute to the catalytic activity and stability of KSI by providing favorable hydrophobic environments and compact packing in the catalytic core. (C) 2016 Published by Elsevier B.V.</P>

<i>MICB</i> polymorphisms and haplotypes with <i>MICA</i> and HLA alleles in Koreans

Cha, C.‐,H.,Sohn, Y.‐,H.,Oh, H.‐,B.,Ko, S.‐,Y.,Cho, M.‐,C.,Kwon, O.‐,J. Blackwell Publishing Ltd 2011 Tissue antigens Vol.78 No.1

<P>Major histocompatibility complex (MHC) class I chain‐related gene B (<I>MICB</I>) is located within the human MHC class I region. The location of <I>MICB</I> in the MHC region may imply the presence of linkage disequilibrium with polymorphic <I>MICA</I> and human leukocyte antigen (HLA) loci. <I>MICB</I> is also polymorphic; however, <I>MICB</I> polymorphisms have not been investigated in Koreans. Using sequence‐based typing (SBT), we estimated the allelic frequencies of <I>MICB</I> and haplotypes with <I>MICA</I>, <I>HLA‐B</I>, and <I>HLA‐DRB1</I> at high resolution in a population of 139 unrelated Korean individuals. Eight <I>MICB</I> alleles were identified. The most frequent allele was <I>MICB*005:02/*010</I> (57.2%), followed by <I>*002</I> (11.5%), <I>*004</I> (8.3%), <I>*005:03</I> (8.3%), and <I>*008</I> (6.8%). The most common two‐locus haplotypes were <I>MICB*005:02/*010‐MICA*010</I> (19.4%), <I>MICB*005:02/*010‐DRB1*15:01</I> (6.5%), and <I>MICB*005:02/*010‐B*15:01</I> (10.4%); the most common three‐locus haplotypes were <I>B*15:01‐MICA*010‐MICB*005:02/*010</I> (5.8%) and <I>MICA*010‐MICB*005:02/*010‐DRB1*04:06</I> (10.4%); and the most common four‐locus haplotype was <I>B*15:01‐MICA*010‐MICB*005:02/*010‐DRB1*04:06</I> (5.8%). This is the first study to provide information about <I>MICB</I> allele frequencies and haplotypes with HLA in Koreans. These study results should help understand mechanisms of disease association between the <I>MICB</I> locus and neighboring loci in Koreans.</P>

Photo-catalytic activity of hydrophilic-modified TiO₂ for the decomposition of methylene blue and phenol

Cha, B.J.,Woo, T.G.,Park, E.J.,Kim, I.H.,An, J.E.,Seo, H.O.,Kim, Y.D. Elsevier 2017 CURRENT APPLIED PHYSICS Vol.17 No.11

<P>We applied hydrophilic surface modification to P-25 TiO2 nanoparticles via thermal deposition of polydimethylsiloxane (PDMS), followed by annealing at 800 degrees C under vacuum conditions. This process yielded a thin layer consisting of hydrophilic organic functional groups (e.g., -C = O) as well as SiOx structures on the surface of TiO2. Compared to bare TiO2, the surface-modified TiO2 showed a higher adsorption capacity and photo-catalytic decomposition rate toward methylene blue. However, regarding the photo-catalytic decomposition of phenol, total mineralization of phenol was more complete when bare TiO2 was used as a photo-catalyst, whereas partial oxidation of phenol (i.e., into hydroquinone) was more dominant and total oxidation of phenol was supressed in the presence of surface-modified TiO2. Overall, one cannot simply say that hydrophilic modification of TiO2 leads to a higher affinity to H2O molecules with a higher yield of strongly-oxidizing agents (OH radicals) to increase the photo-catalytic activity in aqueous solutions. Our results imply that a subtle balance of the adsorption energy or rates of H2O, reactants, and reaction intermediates can be important factors for determining the photo-catalytic reaction rate. Different types of photo-catalyst surface modification can be beneficial or detrimental depending on the reaction. It is highlighted that one should be wary of evaluating the overall photocatalytic activities of dissimilar catalysts based on the results of only a couple of reactions. (C) 2017 Elsevier B.V. All rights reserved.</P>

사염화탄소(CCl₄)에 의한 간손상 흰쥐의 Trithioformaldehyde의 방어효과(Ⅰ)

김영석,김종배,김천숙,권준택,최규홍,이종화,조병헌,차영덕,김유재 순천향대학교 1989 논문집 Vol.12 No.3

Trithioformaldehyde(TTFA) is a cyclic aliphatic compound containing three sulfur atoms. TTFA was synthetized from formalin and hydrogen sulfide in our Lab.. Pharmacological effects of TTFA were clarified in our Lab.: antifungal effects, and radiation protective effect in mice. In this experiment, the protective effect of TTFA on CCl₄ induced hepatotoxicity in rats was evaluated histopathologically. Groups consist of net control, administered with CCl₄ only and TTFA pretreatment. CCl₄(1ml/kg) was given i.p. as a 50%(V / V) solution in olive oil. TTFA(300mg/kg) suspended in 5% arabia gum was given i.p. 24hrs and 20min before CCl₄ administration. The rats that received CCl₄ were sacrificed 24hrs later. In pathological finding, massive fatty change with necrosis in the centrilobular area is found in CCl₄ only treated group. In TTFA pretreated group, a slightly necrotic change in the midzone is noted. Remarkable reductions in hepatic glycogen were observed in CCl₄ only administration. TTFA prevented them from disappearing. These results show that TTFA has a significantly protective effects aganinst CCl₄ induced hepatotoxicity.

배양한 가토신장세포에서 TPA에 의한 지방대사변화에 대한 연구

김성봉,박종수,박주홍,이인수,차종희,김화영,김영래,조영준,이영탁,박재윤,고광삼 朝鮮大學校 附設 醫學硏究所 1987 The Medical Journal of Chosun University Vol.12 No.1

The effect of the tumor promoter 12-0-tetradecanoyl-phorbol-13-acetate on the lipid metabolism of rabbit kidney cells was studied. Modification accompanying the phorbol ester-induced differentiation include an increase in the amount of neutral glycerolipids, and a selective incorporation of long-chain fatty alcohols into triacyglycerols and ether-linked akyldiacylglycerols. There is a possibility that the commitment of cells toward inhibition of differentiation characteristics depends on the predisposition of the cells for alteration in lipid metabolism caused by 12-0-tetradecanoylphorbol-13-acetate.

화학 용액 담금의 열분해 방법에 의한 CdS 반도체의 성장

김홍복,김선미,권영규,차덕준,윤창선,김병호,고정곤,전용기,김광윤 群山大學校基礎科學硏究所 1998 基礎科學硏究 Vol.13 No.-

화학용액 담금의 방법에 의하여 다결정 CdS박막을 성장시켰다. 성장과정에서 온도조건, 몰농도 조건에 따라 CdS 다결정의 특성에 영향을 주는 요인들을 전자현미경, 광흡수 및 광전류 특성과 온도 및 빛의 세기에 따른 저항의 변화를 통해 분석하였다. Polycristalline CdS thin films have been grown by the chemical bath pyrolysis(CBP) method. The CdS films characteristics were investigated with scanning electron microscope(SEM), optical absorption measurements, photoconductivity, and resistance dependences on temperature and light intensity.

노인의 약물 지식 정도와 약물 사용실태 및 약물 오·남용 행위

구예나,김민경,김진윤,배윤,서민혜,정은혜,지수현,차미나,Choi, Jenny 이화여자대학교 간호과학대학 2013 이화간호학회지 Vol.- No.47

Purpose: The purpose of this study was to provide basic data for use in the upgrade of healthcare for the elderly and to provide guidance toward educating the elderly in the proper use of medications by determining the level of drug knowledge, current use, and adherence by the elderly. Method: The participants of this study were selected using the convenient sampling method. Participants of this study comprised of 160 elderly who were aged 65 or older, who were participants to the elderly municipal welfare center in Seoul. The instrument used for this study was a structured questionnaire (Han,2011). Collected data were analyzed using the SPSS20.0 program with descriptive statistics, t-test, ANOVA, and Pearson’s correlation coefficient. Result: The mean score for drug knowledge was 7.6±2.9 and drug misuse was 4.7±2.8. There were significant differences about drug knowledge according to the following: level of education (F=8.053 p=.000), and spouse (t=2.14 p=.034). There were significant differences between drug misuse and monthly income (F=2.167 p=.040). There was no statistically significant relationship between drug knowledge and drug misuse (r=-.087, p=.271). Conclusion: A replication study based on broader region and in-depth research is needed. The development of the customized education protocol considering various levels of education, income, spouse and physical condition are needed. Further research is suggested to find out the status of medication education for the elderly by nurses.