• Title/Summary/Keyword: $Z_2$

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ELECTRON MICROSCOPIC STUDY OF RESIN-DENTIN HYBRID ZONE PRODUCED BY THE MOISTENING OF ACID CONDITIONED DENTIN SURFACE (산 표면처리 후 상아질 표면의 습윤이 하이브리드층 형성에 관한 전자현미경적 연구)

  • Lee, Kwang-Won;Lee, Myung-Jong
    • Restorative Dentistry and Endodontics
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    • v.20 no.2
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    • pp.463-486
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    • 1995
  • The effect of moistening and air-drying of acid-conditioned dentin before priming on the formation of resin-dentin hybrid zone was investigated, Freshly extracted human molars were used and divided at random into 5 groups, Groups 1 - 3 consisted of specimens conditioned with 10 % phosphoric acid for 20 seconds; Group 1 served as a control in which the conditioned dentin was simply blot-dried with a damp facial tissue; Group 2 was air dried for 30 seconds ; Group 3 was air dried for 30 seconds and immediately remoistened for 10 seconds with air-water syringe. and then the specimen was blot-dried with a damp facial tissue. Groups 4-5 were not acid conditioned ; In group 4, the smear layer on the dentin was blot dried before primer placement; Group 5 was air dried only for 30 seconds, The acetone-based primer and bonding agent of All Bond 2 (Bisco. Inc., USA) and composite resin (Z-100, 3M Dental products, USA) were applied for acid conditioned dentin and non-conditioned dentin. The morphologic ultrastructure of resin-dentin hybrid zone was examined by the use of SEM and TEM. and the existence of inorganic material and analysis of Ca/P weight-percent ratio in the resin-dentin hybrid zone were revealed by the EDAX, The results were as follows : 1. In the moistened specimens from acid-conditioned groups, the resin penetrated about 3-$4{\mu}m$ into dentin and the denatured collagen smear layer was not present at the surface. The resin tag was formed to a thickeness of 3-$4{\mu}m$ at the upper part of dentinal tubule and compactively connected to each other by means of many lateral branching. 2. In the air-dried specimens from acid-conditioned groups, the resin penetrated about 2.0-$2.5\;{\mu}m$ into dentin and an upper thin black layer to a thickness of 30-35nm was identified between adhesive resin and demineralized collagen layer. The resin tag to have a diameter of $2.5{\mu}m$ was formed at the upper part of dentinal tubule. However the funnel shape of the tag was not notable compared to the moistened specimens. 3. In the remoistened specimens from acid conditioned groups, the resin penetrated about 2.0-$2.5{\mu}m$ into dentin and an upper black layer was not present. The resin tag at the upper part of dentinal tubule was formed less than $2{\mu}m$ and was weakly connected to each other by means of few lateral branching. 4. In the non-conditioned groups, the smear layer was formed to a thickness of $0.5{\mu}m$ at dentin surface. However, the resin-dentin hybrid zone was not identified by TEM. The evidence of resin penetration into intertubular and intratubular dentin did not show. 5. All the acid-conditioned groups showed that the detected calcium and phosphorus weight percent ratios at the $2{\mu}m$ upper portion from the resin-dentin interface into the resin were much higher than that at the $2{\mu}m$ lower portion from the resin-dentin interface to dentin. (P<0.01).

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New Evidences of Effect of Melanocortin-4 Receptor and Insulin-like Growth Factor 2 Genes on Fat Deposition and Carcass Traits in Different Pig Populations

  • Chen, J.F.;Xiong, Y.Z.;Zuo, B.;Zheng, R.;Li, F.E.;Lei, M.G.;Li, J.L.;Deng, C.Y.;Jiang, S.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1542-1547
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    • 2005
  • The Melanocortin-4 Receptor (MC4R) and Insulin-like Growth Factor 2 (IGF2) are two important candidate genes related to fat deposition and carcass traits. MC4R was found on study on human obesity and then was studied as candidate gene affecting food intake and fat deposition traits in mice and pigs. Insulin-like Growth Factor 2 (IGF2) gene plays an important role on tumor cell proliferation and muscle growth. It also affects fat traits and live weight in pigs. In this paper, MC4R and IGF2 were studied as two candidate genes associated with important economic traits such as fat deposition and carcass traits in five different pig populations. Taq I-PCR-RFLP and Bcn I-PCR-RFLP were respectively used to detect the polymorphism of genotypes of MC4R and IGF2 genes. Different MC4R genotype frequencies were observed in four populations. IGF2 genotype frequencies were also different in two populations. The results of association analysis show both MC4R and IGF2 genes were significantly associated with fat deposition and carcass traits in about 300 pigs. This work will add new evidence of MC4R and IGF2 affecting fat deposition and carcass traits in pigs and show that two genes can be used as important candidate genes for marker assistant selection (MAS) of growth and lean meat percentage in pigs.

Piezoelectric and Electro-induced Strain Properties of $(Pb_{1-2x/3}Bi_x)[(Ni_{1/3}Nb_{2/3})_{0.4}(Ti_{0.6}Zr_{0.4})_{0.6}]O_3$Ceramics with the Substitution of $Bi_2O_3$ ($Bi_2O_3$치환에 따른 $(Pb_{1-2x/3}Bi_x)[(Ni_{1/3}Nb_{2/3})_{0.4}(Ti_{0.6}Zr_{0.4})_{0.6}]O_3$ 세라믹스의 압전 및 전계유기 왜형 특성)

  • 윤현상;정회승;임인호;윤광희;김준한;박창엽
    • Electrical & Electronic Materials
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    • v.10 no.5
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    • pp.434-439
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    • 1997
  • It this paper, the piezoelectric and electro-induced strain properties of (P $b_{1-}$2x/3/B $i_{x}$ )[N $i_{1}$3/N $b_{2}$3/)$_{0.4}$( $Ti_{0.6}$Z $r_{0.4}$)$_{0.6}$] $O_3$ceramics (x=0, 0.005, 0.02) were investigated with the substitution of B $i^{3+}$, and the feasibility of the application for bimorph actuator was evaluated by measuring the dynamic properties of the piezoelectric bimorph fabricated with above ceramics. Dielectric constant was enhanced with the increase of B $i^{3+}$ substitution, and appeared the maximum value of 5032 at x=0.01 composition. Increasing the substitution of B $i^{3+}$, the electromechanical coefficient( $k_{p}$ , $k_{31}$ ) was increased up to the substitution of 0.5 mol% B $i^{3+}$, showed the value of 0.656, 0.439, respectively. The piezoelectric constant( $d_{33}$ $d_{31}$ ) had the highest value of 344, 825 with the substitution of 0.5 mol% B $i^{3+}$. The strain, generated by 60 Hz AC electric field, had the largest value of 1200($\times$10$^{-6}$ $\Delta$1/1) in the composition with the substitution of 0.5 mol% B $i^{3+}$. The dynamic properties of the bimorph actuator, fabricated with the composition substitution of 0.5 mol% B $i^{3+}$, showed the largest value of 325 $\mu$m at $\pm$150 V square pulse. square pulse.are pulse..

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High-$T_c$ 2nd-order SQUID Gradiometer for Use in Unshielded Environments (비차폐 환경에서의 고온초전도 SQUID 2차 미분기의 특성연구)

  • 박승문;강찬석;이순걸;유권규;김인선;박용기
    • Progress in Superconductivity
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    • v.5 no.1
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    • pp.50-54
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    • 2003
  • We have fabricated $∂^2$$B_{z}$ /$∂x^2$ type planar gradiometers and studied their properties in operation under various field conditions. $YBa_2$$Cu_3$$O_{7}$ film was deposited on $SrTiO_3$ (100) substrate by a pulsed laser deposition (PLD) system and patterned into a device by the photolithography with ion milling technique. The device consists of 3 pickup loops designed symmetrically Inner dimension and the width of the square side loops are 3.6 mm and 1.2 mm, respectively, and the corresponding dimensions of the center loop are 2.0 mm and 1.13 mm. The length of baseline gradiometer is 5.8 mm. Step-edge junction width is 3.0 $\mu\textrm{m}$ and the hole size of the SQUID loop is 3 $\mu\textrm{m}$ ${\times}$ 52 $\mu\textrm{m}$. The SQUID inductance is estimated to be 35 pH. The device was formed on a 20 mm ${\times}$ 10 mm substrate. We have tested the behavior of the device in various field conditions. The unshielded gradiometer was stable under extremely hostile conditions on a laboratory bench. Noise level 0.45 pT/$\textrm{cm}^2$/(equation omitted)Hz and 0.84 pT/$\textrm{cm}^2$/(equation omitted)Hz at 1 Hz for the shielded and the unshielded cases, which correspond to equivalent field noises of 150 fT/(equation omitted)Hz and 280 fT/(equation omitted)Hz, respectively. In spite of the short baseline of 5.8 mm, the high common-mode-rejection-ratio of the gradiometer, $10^3$, allowed us to successfully record magnetocardiogram of a human subject, which demonstrates the feasibility of the design in biomagnetic studies.

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Processing and Properties of Calcium Cobaltite Layer Structure Oxide Thermoelectrics (칼슘 코발트 층상 산화물계 열전반도체의 제조와 물성)

  • Kwak, Dong-Ha;Park, Jong-Won;Yoon, Sun-Ho;Choi, Jung-Chul;Choi, Seung-Chul
    • Journal of the Microelectronics and Packaging Society
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    • v.15 no.1
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    • pp.1-6
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    • 2008
  • Thermoelectric properties of calcium cobalt layer structure oxide system, $Ca_3Co_2O_6$ and $Ca_3Co_4O_9$ were investigated at the temperature range of 300 to 1000K for the application of thermoelectric generation. In the composition, the Ca site was partially substituted with Bi, Sr, La, K and the Co site was partially substituted with Mn, Fe, Ni, Cu, Zn. The thermoelectric properties of Bi substituted $Ca_3Co_4O_9$. $Ca_{2.7}Bi_{0.3}Co_4O_9$ for electrical conductivity, Seebeck coefficient and power factor were $85.4({\Omega}$cm)^{-l}, $176.2{\mu}V/K$ and $265.2{\mu}W/K^m$, respectively. The unit thermoelectric couple was fabricated with the p-type of $Ca_{2.7}Bi_{0.3}Co_4O_9$ and n-type ($Zn_{0.98}Al_{0.02}$)O thermoelectrics whose figure-of-merit(Z) were $0.87{\times}10^{-4}/K$ and $0.41{\times}10^4/K$, respectively. The generated thermoelectric power was about 30mV at the temperature difference of 120K in the unit thermoelectric couple.

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Feasibility of Cheonghju Brewing with Wild Type Yeast Strains from Nuruks (누룩으로부터 분리한 Wild Type 효모의 청주(淸酒)제조 가능성에 관한 연구)

  • Kim Hye-Ryun;Baek Seung-Hee;Seo Min-Jae;Ahn Byung-Hak
    • Microbiology and Biotechnology Letters
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    • v.34 no.3
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    • pp.244-249
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    • 2006
  • In order to select the best strains to have the feasibility of Cheonghju brewing, 10 wild type yeast strains from 300 different types of Nuruk were investigated on their ethanol resistance, resistance to glucose and flocculation. The amounts of alcohol, organic acids, and volatile compounds, Brix, pH were also examined for the alcoholic beverages made with the 10 selected strains. Almost all strains showed alcohol production activities in the medium containing 18%(v/v) ethanol and 29%(w/v) glucose. The strains 90-2 showed a higher flocculation activity than other strains. Strains 54-3, 90-2 and 91-5 produced more alcohol than control strain (7.42%(w/w)) when fermented with wild type yeast strains. In addition, alcoholic beverages containing low acetic acid also showed low levels of total acidity. GC/MS analysis of the product showed 4 alcohols, 11 esters and 1 acid as volatile compounds. Selected strains were tentatively identified as Phichia sydowiorum (91-5), Zygosaccharomyces cidri (192-2 and 271-4), and as Saccharomyces cerevisiae (18-2, 54-3, 90-2, 91-2, 98-2, 99-5 and 272-7) by BIIOLOG method.

Flavor Components in Dried Fruit of the Chinese Matrimony Vine during Storage (저장 기간이 짧은 건조 구기자와 오래된 건조 구기자의 휘발성 성분)

  • Choi, Sung-Hee
    • Journal of Life Science
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    • v.24 no.12
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    • pp.1325-1329
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    • 2014
  • Gugija (Lycii chinese Miller) is traditionally consumed as a Chinese medicinal material in food, tea, or alcoholic beverages. Gugija has beneficial healthy components, but it produces an off-flavor during storage. This study compared the flavor components of fresh-dried Gugija and stale-dried Gugija. The flavor compounds in one fresh sample (sample 1) and one stale sample (sample 2) were extracted by the simultaneous distillation and extraction method. The concentrated aroma extracts were analyzed and identified by gas chromatography-mass spectrometry. Forty-five compounds, including 17 aldehydes, 8 alcohols, 6 terpene compounds, 4 esters, 3 ketones, and 3 pyrazines, were isolated in sample 1. Thirty-four compounds, including 12 aldehydes, 3 alcohols, 5 terpene compounds, 2 esters, 3 ketones, 3 pyrazines, and 1 acid, were isolated in sample 2. The main aroma components of sample 1 were 2-methyl butanal, 2-methyl propanol having sweet odor, and hexanal, (Z)-3-hexenol having grass odor, and phenyl acetaldehyde, benzyl alcohol having floral odor, and alkyl pyrazines having nutty odor. These compounds were decreased in sample 2, and several compounds containing isovaleric acid, which has a disagreeable, rancid-cheese odor were found newley.

Secondary Metabolites from the Mycelial Culture Broth of Phellinus linteus (상황(Phellinus linteus) 배양 균사체의 2차 대사산물에 대한 화학적 연구)

  • Song, K.S.;Cho, S.M.;Ko, K.S.;Han, M.W.;Yoo, I.D.
    • Applied Biological Chemistry
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    • v.37 no.2
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    • pp.100-104
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    • 1994
  • From the 48 hour-cultured mycelial broth of Phellinus linteus, six compounds were isolated by means of ethyl acetate extraction, silica gel column chromatography and preparative thin layer chromatography, consecutively. Compound 1 was identified as a succinic acid by the comparison of its spectral data with authentic sample. Compounds 2 and 3 were identified as p-hydroxyphenyl acetic acid methyl ester and p-hydroxybenzaldehyde by spectroscopic studies, respectively. NMR and MS studies of compound 6 revealed that it was 2,5-dihydroxymethyl furan. Compound 4, which showed similar NMR absorptions and MS fragmentation pattern with those of compound 6 was identified as 2-hydroxymethyl-5-methoxymethylfuran. These structures were verified by the spectral data of the acetate derivatives of the compounds. Compound 5 was supposed to be a N-acetyltyramine from its $^1H-NMR$ and EI-MS data, and its structure was confirmed by a synthesis starting from tyramine.

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THE HISTOPATHOLOGICAL STUDY ON THE RESPONSE OF THE REMAINING PULP TISSUES TO THE ADHESIVE RESIN AFTER PULPOTOMY (치수절단 후 접착레진 도포에 대한 잔존치수조직 반응에 관한 연구)

  • Lim, Sung-Sam;Park, Dong-Sung;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.22 no.2
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    • pp.720-730
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    • 1997
  • This study was performed to observe the histopathological response to the bonding resin directly applied on the remaining pulp tissues. 40 teeth from 3 adult dogs were pulpotomized with a sterile round bur and sharp excarvater. In the control group, $Ca(OH)_2$ powder was applied on the pulp tissue and the cavities were sealed with IRM cement. In the experimental group 1, Superbond C&B was applied on the remaining pulp and the cavities conditioned with 10-3 solution were filled with the mixture of the MMA liquid, PMMA powder and Catalyst. Multi-purpose adhesive was used on the remaining pulp tissue in the experimental group 2 and Z-100 was filled in the cavities. In the experimental group 3, Clearfil photobond applied and directly photo-cured on the pulp tissue, then the cavities were treated with CA agent (10% citric acid and 20% $CaCl_2$ aqueous solution) for 20 seconds, washed and applied with Clearfil photobond then filled with Protect liner. The experimental animals were sacrified at the 1st, 2nd, and 4th week. The specimens were routinely processed and stained with H-E for light microscopic observation. The results were as followed : 1. In the experimental group 1, the number and characteristics of the dentin bridge formation case was similar to those in the control group and less cases were observed in the experimental group 2 and 3 than experimental group 3. The inflammatory response in experimental group 1 was less than that in the control group at 1st week but there had been little difference at between 2nd and 4th week. 2. The number of the dentin bridge in experimental group 2 was less than that in control group and experimental group 1. The inflammatory response of the experimental group 1 was similar to that of experimental group 1 but less than that of the control group. A number of bleeding and vascular congestion were observed. The least inflammatory response was seen in the experimental group 2 among all groups. 3. In the experimental group 3, one case of the dentin bridge formation was observed and that was the same as that in the experimental group 2 but smaller than that of the control and experimental group 1. The inflammatory response of the experimental group 3 was least at the 1st week and most at the 4th week in the all group.

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Antioxidative Activity of Extract from Bangah Herb (방아 추출물의 항산화 효과)

  • Jhee, Ok-Hwa;Yang, Cha-Bum
    • Korean Journal of Food Science and Technology
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    • v.28 no.6
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    • pp.1157-1163
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    • 1996
  • Bangah, one of the herbs grown in Korea, was investigated for its antioxidant activity. The ether extracts of bangah herb was separated into neutral, phenolic, acidic and basic fractions and further separated into subfractions. Antioxidative activities were measured by hydrogen donating activity (HDA), peroxide value (POV), thiobarbituric acid (TBA) value and inhibition activity against lipid peroxidation of rat liver microsomes, The subfraction components were identified by GC/MS and NMR. Phenolic, though being very small in quantity, showed higher antioxidant activity at all assay system by hydrogen donating activity. POV, TBA value and inhibition activity against lipid peroxidation of rat liver microsomes. Five subfractions(P-1, P-2, P-3, P-4 and P-5) were fractionated from phenolic fraction of bangah herbs, and subfraction P-2 among them showed strong antioxidant activity on a level with BHT or gallic acid at each assay system. Four compounds (peak I, peak II, peak III and peak IV) were isolated by gas chromatogram of TMS derivatives of subfraction P-2 and thes compounds were confirmed to be phenolic substance having -OH and COOH group. There subfractions (N-1, N-2 and N-3) were fractionated from neutral fraction of bangah herbs, and subfraction N-2 among them showed highest antioxidant activity and inhibition activity against lipid peroxidation of rat liver microsomes. Subfraction N-2 was indentified to be estragole by H-NMR spectroscopy.

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