• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1175-1179
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• 1998

The aerobic reaction of 2-(acetylpyridine)-S-methyldithiocarbazate (acpy-mdtcH) and 2-(acetylpyridine)-N-phenylthiosemicarbazate(acpy-phTscH) with manganese(Ⅱ) acetate affords Mn(acpy-mdtc)2 and Mn(acpyphTsc)2, respectively. The spectroscopic data and X-ray structure of Mn(acpy-mdtc)2 are reported. Crystal data for Mn(acpy-mdtc)2; C18H20N6S4Mn, mol wt 503.58, monoclinic crystal system(P21/c) a=12.240(5) Å, b= 10.918(l) Å, c=17.651(3) Å, β=105.93(2), and V=2268(l) Å3, Z=4, 5071 data collected with 0°< 2θ < 52.64°, 2995 data with I > 3σ(I), R= 0.046, Rw= 0.065. The ligands act as tridentate NNS donors. The two Mn-S distances are not equal, and respectively 2.512(2) Å and 2.541(2) Å. The average Mn-N (azomethine) length, 2.242(5) Å, is slightly shorter than the average Mn-N (pyridyl) length, 2.262(5) Å. The coordination environment about MN(Ⅱ) center deviates considerably from octahedral geometry. The manganese(Ⅱ)-manganese(Ⅰ) and manganese(Ⅰ)-manganese(0) reduction potentials of Mn(acpy-mdtc)2 are ∼-l.71 and ∼-l.98 V while those of Mn(acpy-phTsc)2 are ∼-l.87 and ∼-2.11 V vs. Ag/Ag+ in dimethyl sulfoxide, respectively.

• Korean Journal of Microbiology
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• v.17 no.4
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• pp.187-192
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• 1979

Dennis (1972) reported that Trichosporon cutaneum FRI-425 from the petioles of Pheum rhamponticum var, had showed the celluloytic activity. Chun (1977) also suggested that Trichoporon pullulons 225 isolated from the saline water of the Yeoung San River had a similar properties. However, the assay conditions for enzyme activity were not yet investigated. Thus, the present work was undertaken to examine some conditions for CMCase activity and at the same time to compare the activities of crude enzyme produce from above two species of Trichosporon pullulans. The results are as follows; 1. The maximum production of total reducing sugar by crude enzyme of Tr. pululans was after 30 minutes, whereas that of Tr. cutanuem FRI-425 was after 90 minutes. This fact showed that the reaction velocity of enzyme from Tr. pullulans 225 was more faster than that of Tr. cutaneum FRI-425. 2. Two species showed a similar trend to increase the production of reducing sugar in proportion to the increment in substrate concentration and to arrive at maximum level at lmg/ml of substrate concentration. However, Tr. pullulans 225 produced more $50{\mu}g$ of reducing sugar compared to Tr. cutaneum. 3. The optimum PH for CMCase activity is 5.0 for Tr. pullulans 225 as well as Tr. cutaneum FRI-425, and PH stability lie within the range of 6 and 8. In the activity and stability of enzyme on PH changes, enzyme of Tr. cutaneum FRI-425 was more unstable than that of TY. pullulans 225. 4. The optimum temperature for CMCase activity was $40^{\circ}C$, and enzyme activity from Tr. pullulans 225 was more sensitive to temperature changes compared with that of TY. cutaneum. The heat stability was within $40^{\circ}C$, but that was rapidly decreased above $40^{\circ}C$. In comparison of the heat stability for enzyme of Tr. cutaneum FRI-425 with that of Tr. pullulans 225 at the same temperature of $80^{\circ}C$, the former was some 10 percent more stable than the latter.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.582.1-582.1
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• 2006

• Applied Biological Chemistry
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• v.27 no.4
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• pp.271-277
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• 1984

Molecular weight of Exo-maltotetraohydrolase produced by Pseudomonas stutzeri IAM 12097 was estimated to be approrimately 63,000 and 60,000 with SDS-polyacrylamide gel electrophoresis and Sephadex-G-100 gel filtration, respectively. The isoelectric point was appeared to be pH 4.8. Optimum pH, the stable pH range and optimum temperature of this enzyme were pH 6.6, $pH6.0{\sim}10.5\;and\;45{\sim}50^{\circ}C$. The enzyme was stable below $40^{\circ}C$ and was rapidly inactivated above $55^{\circ}C$. This enzyme was inactivated completely by $Ag^+,\; Hg^{++},\;I_2$ and ${\beta}-cycoldextrin$, and slightly by EDTA, ${\rho}-CMB$ and IAA. Michaelis constant(Km) of this enzyme toward soluble starch, amylose and amylopectin were 7.70mg/ml, 6.17mg/ml, 5.56mg/ml, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.3
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• pp.15-22
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• 2003

The fatigue crack growth model is derived and the retardation model is proposed. The fatigue crack growth model considers the residual plastic stretch on the crack surface which results from the plastic deformation at the tip of fatigue crack. The fatigue crack growth rate is calculated by using the cumulative fatigue damage and plastic strain energy in the material elements at the crack tip. This model gives the crack growth rate in reasonable agreement with test data for aluminum alloy AL6061-T651 and 17-4PH casting steel. The fatigue crack growth retardation model is based on the residual plastic stretch produced from a tensile overload which reduced the plastic strain range of the following load cycles. A strip-yield model of a crack tip plasticity is used for the calculation of a plastic zone size. The proposed retardation model characterized the observed features and delayed retardation of the fatigue crack growth under tensile overload.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.313-319
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• 2004

The distribution and characteristics of acidotolerant heterotrophic and naphthalene-degrading bacteria were investigated in two forest areas, one near Ulsan petrochemical industrial complex (Sunam) and the other in countryside (Daeam). Average values of soil pH at Sunam and Daeam were 3.8 and 4.6, respectively. When het­erotrophic and naphthalene-degrading bacteria were enumerated by most probable number (MPN) procedures at Sunam, the median values of heterotrophs growing at pH 7.0 and pH 4.0 were $5.3{\times}10^7\;and\;3.3{times}10^7$ MPN/g, whereas those of naphthalene-degraders were $5.6{\times}10^4\;and\;4.0{times}10^5$ MPN/g, respectively. While the medians of heterotrophs at Daeam were larger than those at Sunam, the concentrations of naphthalene-degraders were higher at Sunam compared to those at Daeam. From the MPN tubes and enrichment cultures, we obtained 17 isolates of naphthalene-degraders which were identified as Sphingomonas paucimobilis, Brevundimonas vesic­ularis, Burkholderia cepacia, Ralstonia pickettii, Pseudomanas fluorescens, and Chryseomonas luteola. Among them, 6 isolates showed higher naphthalene-degrading activity on minimal media of pH 4 compared to pH 7, whereas the extent of growth was not greater at pH 4 than at pH 7 when they were inoculated on nutrient-rich media. It is plausible that the pH may affect naphthalene-degrading activity of the isolates by changing fatty acid composition of bacterial membrane.

• Journal of the Korean Home Economics Association
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• v.36 no.8
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• pp.123-140
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• 1998

The purpose of this study was to verify preschool children can be classified of Attention-Deficit Hyperactivity Disorder (ADHD) children across situation. It also was to examine differences among groups according to sex and age, and to investigate the family caracterisitcs of ADHD groups. The subjects of this study consisted of 228 preschool chilren (147 boys and 136 girls aged from 3- to 7- year-old) drawn from five Child Care Centers in Chung-Ju. Data were analyzed by the frequency, percentages, Cronbach's ${\alpha}$ coefficient, ${\chi}^2$-test, F-test, Tukey post-hoc test, and Pearson correlation using SAS program. The results were as follows: 1. Preschool children could be classified by four diagnostic groups across situation; (1) 168 children (59%) of the control group (no disorder of ADHD), (2) 49 children (17%) of ADHD-Home group (ADHD only at home), (3) 43 children (15%) of ADHD-School group (ADHD only at school), and (4) 23 children (8%) of ADHD-PH group (ADHD both at home and at school). Ratings by parents and by teachers correlated very low with each other, as in previous studies. These results confirm the findings that ADHD be classified across situation. 2. There were significant differences among four groups according to sex and age. In the ADHD-PH groups, the boys is 3 times higher than the girls and the children aged 6- to 7-year-old was shown highly distributed in the pervasive ADHD.

• Bulletin of the Korean Chemical Society
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• v.10 no.2
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• pp.191-196
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• 1989

We obtained the new complexes, $Fe{\eta}^4-R,R'-TPSCp](CO)_3$(R,R'-TPSCp = 1,1-disubstituted 2,3,4,5-Tetraphenyl-1-Silacyclopenta-2,4-diene; R = Ph, R' = Cl, R = R' = Cl) from the reaction of the corresponding R,R'-TPSCp with ironpentacarbonyl under reflux in toluene. Also, the analogous complexes with R = R' = Me and R = Me, R' = Cl were obtained in an identical manner. We have determined the crystal structure of $Fe[Ph(Cl)-TPSCp](CO_)3$ by using Mo ka, ${\lambda}$ = 0.71069${\AA}$, where the unit cell was found to be monoclinic with a = 9.042 (6)${\AA}$, b = 19.870 (9)${\AA}$, c = 17.426 (9)${\AA}$ and ${\beta}$ = 96.28(4)$^{\circ}$. The butadiene moiety of TPSCp ring is planar and the dihedral angle of the butadiene plane and C4-Si-C25 plane was opened up to 41.8$^{\circ}$. The C-C distances in the butadiene moiety were found to be 1.4346, 1.462, and 1.440 ${\AA}$, respectively. It may be said that the four ${\pi}$-electrons are delocalized over the four carbons in five membered ring through coordination with ironcarbonyl. In this complex Fe is either in distorted tetrahedron environment with the centroid of the four C-atom butadiene moiety and three carbons of the three carbonyls or in distorted square-pyramidal environment with two midpoints of double bonds of the butadiene moiety and two carbons of carbonyl defining the base of the pyramid and the carbon of remaining carbonyl the apex.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.280-287
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• 2000

Three antimicrobial compounds (SL-l, SL-2 and SL-3) were isolated and identified from the marine red alga, Symphyocladia latiuscula. In addition, their biological functionalities such as cytotoxicity and desmutagenic activity were investigated. From the cryophyllized S. JatiuscuJa, SL-l, SL-2 and SL-3 were purified by solvent extractions and HPLC.SL-2 was crystallized in benzene-diethyl ether solvent. On the EI-MS spectra, it was found that they had three bromines in their structure which showed typical signal strength ratios at $M^+, [M+2]^+, [M+4]^+, [M+6]^+ (13: 38: 37: 12)$. $SL-l$ was identified as 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol ($C_8H_7Br_3O_3, MW=374$) by NMR and MS spectra. SL-2 was assigned as 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether ($C_8H_7Br_3O_3, MW=388$) and confirmed by X-ray crystallographic analysis. SL-3 was presumed as an isomer of SL-2. Methanol extract of the S. latiuscula showed antimicrobial activities against all strains tested (bacteria, 15 strains; yeasts, 17 strains; fungi, 4 strains), much or less. The strongest inhibition activity of the methanol extract was to the Vibrio mimicus ($50 {\mu}g/ml$) and V. vulnificus ($50 {\mu}g/ml$). The mice injected intraperitoneally with 3 mg of SL-l and 5 mg of 5L-2 showed no acute toxicity response. SL-2 showed higher desmutagenic activity than SL-l against PhIP and MeIQx.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.248.2-248
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• 1979

식초산 발효 실험을 통하여 다음과 같은 결과를 얻었다. 1. 자연에서 초산균 52균주를 분리하고 그중 식초산 농도 5.5% 이상되는 초산균 CAU-4, CAU-15, CAU-17, CAU-46, 4균주를 선별하였다. 2. 정치배양과 진탕배양을 실시한 결과 산생성랑은 진탕배양에서 월등한 효과를 보였다. 3. 유기태 질소원의 첨가시 peptone을 0.4%까지 증가를 보였고, yeast extract는 0.1~0.2%가 최적량이고 그 이상은 산량이 감소되었다. 4. $NH_4NO_3의$ 자화성을 조사한 결과 CAU-17만이 자화하지 못하였고, 무기태 질소원으로서는 $(NH_2)_2CO가$ 가장 좋았다. 5. 무기염류는 $KH/_2PO_4,$ $MgSO_4.7H_2$ O 0~0.1% 첨가하여 약간의 효과를 보았다. 6. Glucose의 첨가량별 산량의 증가는 0.25% 첨가시 0% 첨가시 보다 증가를 보인 반면 1% 첨가시는 오히려 감소하였다. 7. 초발 alcohol농도가 낮을수록 유도기와 대수기가 단축되며 10%이상에서는 4균주 모두 산을 생성하지 못하였다. 8. 초발산도가 높을 경우 유도기가 길어지고 산생성량이 줄어 들었다. 9. 초산균의 배양온도는 $30^{\circ}C,$ $35^{\circ}C에서$ 산생성 속도가 가장 빨랐다. 10. 발효시 산생성량에 따른 세균수의 증가는 접종후 2~3일 사이에 가장 많았다. 11. 초산의 증가와 더불어 균체량은 증가하였고 pH는 약간색 감소하나 PH는 2.5이하로는 내려가지 않았다. 12. alcohol 잔량은 발효 개시 후 5 ~6일의 정지기에 가장 낮았다.