• Title/Summary/Keyword: complex phosphate

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THE EFFECT OF CYCLIC LOADING ON THE RETENTIVE STRENGTH OF FULL VENEER CROWNS (반복 하중이 Full veneer crown의 유지력에 미치는 영향에 관한 연구)

  • Kim, Ki-Youn;Lee, Sun-Hyung;Chung, Hun-Young;Yang, Jae-Ho;Heo, Seong-Joo
    • The Journal of Korean Academy of Prosthodontics
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    • v.38 no.5
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    • pp.583-594
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    • 2000
  • Dislodgement of a crown or extension bridge and the loosening of a retainer of a bridge is a serious clinical problem in fixed restoration. Generally these problems are considered to be associated with deformation of the restoration. During biting, the restoration is subjected to complex forces and deforms considerably within the limit of its elasticity. Deformation of the restoration under the occlusal force induces excessive stress in the cement film, which then leads to the cement fracture. Such a fracture may eventually cause loss of the restoration. Because most of the past retention tests for full veneer crown were done without fatigue loading, they were not exactly simulating intraoral environment. And the purpose of this study was to evaluate the effect of cyclic cantilever loading on the retentive strength of full veneer crowns depending on different type of cements and taper of prepared abutment. Steel dies with $8^{\circ}\;or\;16^{\circ}$ convergence angle were fabricated through milling and crowns with the same method. These dies and crowns were divided into 8 groups. Group 1 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 2 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 3 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 4 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 5 : $16^{\circ}$ taper die, cementation with Panavia 21, without loading Group 6 : $16^{\circ}$ taper die, cementation with Panavia 21, with loading Group 7 : $8^{\circ}$ taper die, cementation with Panavia 21 without loading Group 8 : $8^{\circ}$ taper die, cementation with Panavia 21, with loading After checking the fit of die and crown, the luting surface of dies and inner surface of crowns were air-abraded for 10 seconds. The crowns were cemented to the dies, with cements mixed according to the manufacturer's recommendations. A static load of 5kg was then applied for 10 minutes with static loading device. Twenty-four hours later, group 1, 3, 5, 7 were only thermocycled, group 2, 4, 6, 8 were subjected to cyclic loading after thermocycling. Retentive tests were performed on the Instron machine. From the finding of this study, the following conclusions were obtained 1. Panavia 21 showed significantly higher retentive strength than zinc phosphate cement for all groups (p<0.05). 2. There was a significant difference in the retentive strength between $8^{\circ}\;and\;16^{\circ}$ taper for zinc phosphate cement(p<0.05), but no significant difference for Panavia 21 (p>0.05). 3. Cyclic loading significantly decreased the retentive strength for all groups(p<0.05). 4. For zinc phosphate cement, there was 35% reduction of the retentive strength after loading in the $16^{\circ}$ taper die, 25% in the $8^{\circ}$ taper die, and for Panavia 21, 21% in the $16^{\circ}$ taper die, 18% in the $8^{\circ}$ taper die.

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Complex Formation of Uranium(VI) with Organic Phosphate Ligands in the Solvent Extraction System (용매 추출계에서의 우라늄(VI)-유기인산에스테르 착물의 형성에 관한 연구)

  • Do Young Kyu;Sohn Youn Soo
    • Journal of the Korean Chemical Society
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    • v.22 no.5
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    • pp.320-325
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    • 1978
  • In order to elucidate the mechanism associated with the solvent extraction of uranium(VI) using DEPA and DPPA as extractant the uranium(VI) complexes formed during the solvent extraction were isolated and characterized by means of IR, NMR, chemical analysis and molecular weight determination. It has been found that uranium(VI) replaces the acidic hydrogen ions of the extractants DEPA and DPPA to form chelated polynuclear complexes, the molecular weight of U(VI)-DEPA complex being $2.1{\times}10^4$. The isolated U(VI)-DEPA complex has been found to be the same chemical species as is formed during the solvent extraction process. In case of DEPA the distribution coefficient of uranium is the largest of the pure aqueous uranium solution and is increasing for the acidic solutions in the order of $H_3PO_4.

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Anti-Acne Effects of Herbal Complex in Acne Vulgaris Mouse Model (마우스 모델에서의 생약복합제의 여드름 치료 효능)

  • Lee, Ki Man;Lee, Geum Seon;Shim, Hong;Oh, Se Koon;Park, Il Ho;Yim, Dongsool;Kang, Tae Jin
    • Korean Journal of Pharmacognosy
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    • v.43 no.4
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    • pp.323-327
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    • 2012
  • Acne, also known as Acne vulgaris, is a common disorder of human skin involving the sebaceous gland and Propionibacterium acnes (P. acnes). The purpose of this study was to demonstrate whether anti-acne herbal complex (AAHC), a functional extract from herbal complex can be used for acne treatment as a natural product. We first demonstrated anti-acne activity of AAHC in mouse acne model. Acne was induced by injecting P. acnes on the backside $2{\times}10^7$ CFUs in ICR mice and then the mice were treated with AAHC by dermal application once daily. ACFREE$^{(R)}$ (clindamicin phosphate) was used as a positive control. Treatment with AAHC decreased the P. acnes-induced skin swelling and inflammation. AAHC treatment significantly decreased serum DHT concentration in acne-induced mice. Especially, treatment of 20% AACH in mice was more effected than 40%. We next evaluated the antimicrobial property of AAHC against P. acnes, Staphylcococcus aureus (S.aureus), and Escherichia coli (E. coli). Incubation of P. acnes, S. aureus, and E. coli with AAHC showed minimal inhibitory concentration (MIC) values against the bacterial growth lower. Alamar blue method was also carried for the antibacterial activity. It was effectively MIC level at 6.25% of P. acnes. AAHC effectively inhibited the growth of S. aureus and E. coli at 0.097% on MIC level, respectively. Our results showed the potential of using AAHC as an alternative treatment for antibiotic therapy of acne and the application of AAHC as a herbal medicine for acne treatment.

Rapid Detection of Salmonella spp. by Antibody Immobilization with Gold-protein A Complex (Gold-protein A Complex 항체 고정화법을 이용한 Salmonella spp.의 신속 검출)

  • Park, In-Seon;Kim, Nam-Soo
    • Korean Journal of Food Science and Technology
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    • v.31 no.1
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    • pp.1-6
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    • 1999
  • A piezoelectric (PZ) biosensor system detecting Salmonella spp. was developed. The system consisted of an oscillator, a frequency counter and an antibody-immobilized quartz crystal. An anti-Salmonella antibody was immobilized on one gold. surface of the quartz crystal with protein A. Salmonella detection was made by measuring resonant frequency shift owing to a mass change by specific binding of microbial cells to the gold surface of the PZ crystal. The PZ antibody sensor was operated optimally at 0.1M phosphate buffer, pH 7.2 and $35^{\circ}C$. The sensor was quite specific to Salmonella spp. The obtained frequency shift was correlated with the Salmonella concentration in the range of $10^5{\sim}10^6\;CFU/mL$. The frequency shift increased further by addition of polystyrene beads. The Salmonella detection which is indicated by a steady-state microbial adsorption to the quartz crystal was accomplished within 50min.

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Biomimetic Copper Complex Containing Polymer Modified Electrode for Electrocatalytic Reduction of Oxygen

  • Saravanakumar, D.;Nagarale, Rajaram Krishna;Jirimali, Harish Chandra;Lee, Jong Myung;Song, Jieun;Lee, Junghyun;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.7 no.4
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    • pp.298-305
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    • 2016
  • The development of non-precious metal based electrocatalysts is highly desired for the oxygen reduction reaction (ORR) as alternates to noble metal based ORR electrocatalysts. Herein, we report mononulcear copper(II) complex $[CuLbpy]ClO_4$ (L=4-[(2-hydroxyphenylimino)methyl]benzoic acid) containing poly(allylamine.HCl) polymer (PAlACuLbpy) as an electrocatalyst for oxygen reduction reaction (ORR). PAlACuLbpy was mixed with poly(acrylic acid) and tetraethylortho silicate to prepare a composite and then deposited on the screen printed electrode surface. The modified electrode (PAlACuLbpy/PCE) is highly stable and showed a quasi-reversible redox behavior with $E_{1/2}=-0.2V$ vs. Ag/AgCl(3 M KCl) in 0.1 M phosphate buffer at pH 7 under argon atmosphere. PAlACuLbpy/PCE exhibited a remarkable ORR activity with an onset potential of -0.1 V vs Ag/AgCl in 0.1 M PB (pH 7) in the presence of oxygen. The kinetics for ORR was studied by rotating disk voltammetry in neutral aqueous medium and the results indicated that the number of electrons involving in the ORR is four and the conversion products are water and hydrogen peroxide.

Determination of Boron by Ion Pair Liquid Chromatography with Chromotropic Acid (Chromotropic Acid를 착화제로 이용한 이온쌍 액체 크로마토그래피에 의한 붕소의 분리와 정량)

  • Yun, Young Ja;Yu, Gu Yong
    • Journal of the Korean Chemical Society
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    • v.39 no.4
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    • pp.288-293
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    • 1995
  • The separation and determination of boron with chromotropic acid (1,8-Dihydroxynaphthalene-3,6-disulfonic acid) as a complex agent has been studied using ion pair liquid chromatography. The use of tetrabutylammonium bromide added as an ion pair reagent to mobile phase (MeOH 61%, phosphate buffer 39% pH=8.5) allowed good separation of boron-chromotrophic acid complex anion and chromotrophic acid on poly(styrene-divinylbenzene) based reversed phase column (PRP-1, 15 $cm{\times}4.6$ mm i.d.). The complex formation between boric acid and chromotrophic acid was enhanced in the presence of 0.1 M tetrabutylammonium bromide, resulting in high sensitivity. The linear calibration was achieved over the boron concentration range of 0.5∼1000 ${\mu}g/L.$ The detection limit was 0.5 ${\mu}g/L$ (S/N=2). The proposed method was applied to the determination of boron in commercially available chemicals, $Na_2SO_4$, NaOH, KCl.

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Glutamine Synthetase of some Fermentation Bacteria: Function and Application

  • Tachiki, Takashi
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.506-508
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    • 1986
  • Metabolic activity of inorganic nitrogenous compounds affects not only microbial growth but also metabolite production in fermentation technology. We have worked on the enzymes participating in ammonia assimulation of some fermentation bacteria. This paper summarizes the results on glutamine synthetase and its application in practical field. Glutamine synthetase (L-glutamate:ammonia ligase, EC. 6.3.1.2) catalyzes the formation of glutamine from glutamate and ammonia at the expense of cleavage of ATP and inorganic phosphate. The enzyme plays a dual role in nitrogen metabolism in bacteria; it is a key enzyme not only in the biosynthesis of various compounds through glutamine but also in the regulation of synthesis of some enzymes involved in the metabolism of nitrogenous compounds. The detailed works with the Eschericia coli and other enterobacterial enzymes revealed that glutamine synthetase is controlled by the following complex of mechanisms: (a) feedback inhibition by end products, (b) repression and derepression of enzyme synthesis, (c) modulation of enzyme activity in response to divalent cation and (d) covalent modification of enzyme protein by adenylylation and its cascade control. Comparative studies have also been made on the enzymes from other organisms.

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Identification of Ran-binding protein M as a stanniocalcin 2 interacting protein and implications for androgen receptor activity

  • Shin, Jihye;Sohn, Young Chang
    • BMB Reports
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    • v.47 no.11
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    • pp.643-648
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    • 2014
  • Stanniocalcin (STC), a glycoprotein hormone originally discovered in fish, has been implicated in calcium and phosphate homeostasis. While fishes and mammals possess two STC homologs (STC1 and STC2), the physiological roles of STC2 are largely unknown compared with those of STC1. In this study, we identified Ran-binding protein M (RanBPM) as a novel binding partner of STC2 using yeast two-hybrid screening. The interaction between STC2 and RanBPM was confirmed in mammalian cells by immunoprecipitation. STC2 enhanced the RanBPM-mediated transactivation of liganded androgen receptor (AR), but not thyroid receptor ${\beta}$, glucocorticoid receptor, or estrogen receptor ${\beta}$. We also found that AR interacted with RanBPM in both the absence and presence of testosterone (T). Furthermore, we discovered that STC2 recruits RanBPM/AR complex in T-dependent manner. Taken together, our findings suggest that STC2 is a novel RanBPM-interacting protein that promotes AR transactivation.

Effect of ion-pair complexation with bile acids on the bilary excretion and systemic distribution of organic drugs

  • Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.9 no.1
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    • pp.49-54
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    • 1986
  • Effect of sodium taurodeoxycholate (TDC) infused intravenously on the pharmacokinetics of methylene blue (MB) was studied in the rat to investigate the role of ion-pair complexation in the body on drug elimination and disposition. Distribution volume (Vd) of MB was increased significantly (p< 0.05) by TDC infusion. Considering together with the fact that apparent partition coefficient (APC) of MB between phosphate buffer (pH 7.4) and n-octanol was increased markedly by TDC, the increase in Vd seemed to be the result of decreased polarity of MB by ion-pair formation with TDC. But total body clearance (CLt) and biliary excretion clearance (CLbil) of MB were not increased significantly by TDC.

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해수-석탄회 상호작용에 의한 미량원소 용출특성:Batch 실험연구

  • 박성민;김강주;황갑수;김진삼
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.09a
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    • pp.295-298
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    • 2004
  • It was revealed that leaching of elements were partly inhibited because seawater contains plenty of dissolved ions than fresh water. On the other hands, the low activity coefficient and the formation of complex with chloride and sulfate play roles in enhancing element leachability. However, the pH buffaring capacity of seawater is the most important factor that makes the leaching of elements and its chemical behavior in the seawater system different from those in the fresh water environments. In general, the leaching from the weathered ash was smaller than that from the fresh ash. However, it was revealed that the leaching of Si, Fe, Al, Mn, phosphate, and some other elements were independent of ash weathering. They were dependant only on the pH of the solutions.

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