• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5221-5231
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• 2010

The complex formation from Ni(II) ion and 2-(2-Hydroxyethylamino)-2-(hydroxymethyl)-1,3-propanediol(Monotris) in aqueous solution at $25^{\circ}C$ and at ionic strength of 0.10M has been studied potentiometrically. In the Monotris(L) comlex $NiL^{2+}$, hydroxyl oxygen atom as well as the amine nitrogen of the ligand are coordinated to the Ni(II) ion.. The complex $NiL^{2+}$ undergoes further dissociation as the pH is increased forming triply deprotonated dinuclear complex $Ni_2L_2H_{-3}^+$.

• Journal of Environmental Science International
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• v.13 no.1
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• pp.89-97
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• 2004

An author has been known that A-type zeolite supported with silver ions has excellent antibacterial activity. However, it is no research of concern in the antibacterial activity of eluted silver ions. This study tested the elution of silver ions from A-type zeolite silver ions in deionized distilled water and NaNO$_3$ aqueous solution. In NaNO$_3$ aqueous solution of 74mM to 588mM, it was found that the concentration of silver ions and electric conductivity increased with the increasing concentration of sodium ions, and equilibrated at 15 min, and the ion exchange equilibrium coefficient, k, is 1.3${\times}$10$\^$-3/. However, deionized distilled water is not equilibrated to pass 6 months. A-type zeolite sodium ions showed no antibacterial activity. It was found that antibacterial activity was exhibited even at the concentration of 10 nM of eluted silver ions, and E-coli died with the incorporation of 2.43${\times}$10$\^$8/ Ag ion/cell. antibacterial activity of A-type zeolite silver ions were mainly attributed to hydroxyl radical.

• Journal of the Korean Ceramic Society
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• v.12 no.1
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• pp.16-22
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• 1975

The network structure of a glass is known to be cracked by a chemical reaction, diffusion, and ion exchange of alkali ion, formed at the crack tip of the glass surface, when water is present on the glass surface. Since the durability of glass is reduced, due to the fatigue phenomenon mentioned above, pollution problem of glass goods, especially bottle glass, is becoming acute gradually. A static fatigue phenomenon was studied thermodynamically in this paper, and a mechanism of static fatigue, a quality control, and a method of preventing pollution for the main local glass goods were also investigated. The PH of reacted solution and the quantity of extracted alkali were measured at different conditions such as temperature, reacting time, particle size of a crushed glass sample, and the nature of reacting solution. The enthalpy change was calculated from the Arrhenius equation. The results are given below; 1) The absolute value of enthalpy change for the bottle glass was found to be higher than the for the flat glass. 2) The fatigue phenomenon of a glass was more sensitive to the temperature than to the reacting time. 3) The durability of glass in acid solution is stronger than in alkaline solution. 4) The substance which cracks the network structure of glas is considered the hydroxyl ion.

• Journal of the Korean Chemical Society
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• v.67 no.4
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• pp.222-225
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• 2023

Metallic salts of C10-18 aliphatic carboxylic acids were prepared and their scanning electron microscopic images were analyzed for the morphology dependency with the metal and the carboxylic acid. Regardless of metal ion, metal salts of dicarboxylic acids showed a high crystallinity with a fiber image (SuA-Na). The aromatic dicarboxylates also represented a morphology of a rectangular-rod or board shapes (IA-Li, IA-Ba). With Na ion, most aliphatic carboxylate (MA, PA, SA) showed a fiber-like crystallinity. However, other monovalent Li, K and multivalent Mg, especially Al ion resulted a glassy-amorphous in the metallic salts of acids (MA, PA, SA). With divalent Ba and Ca ions, the metal salt of aliphatic acids expressed a branched round cluster shape as in SA-Ca, SA-Ba. Both Li and Mg ions with a similar size showed a strong morphological similarity in the metallic salts of aliphatic acids MA, PA, SA. In the case of Na and Ca ions with a similar size (98, 106 pm), both ionic salts of stearic acid gave a branching effect for a fiber or round granular image. In the case of hydroxyl-aliphatic acids (HLA, HPA, HSA), the fiber images in HLA-Na and HSA-Na was appeared about 100 nm thicker than those of nonhydroxycarboxylates (LA-Na, SA-Na). The metallic salts of unsaturated C-18 carboxylic acids (OlA, LeA and LnA) showed an amorphous glassy image due to a kinked carbon chain.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.626-632
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• 2001

The plant extracted from Nameko, Gallic, Green tea, Allspice, Polygonum multiflorum, Schizandra chinensis, Armeniacae and Pine needle were utilized to investigate the effects of extracts on free radical reaction, lipid oxidation and nitrite scavenging ability. The pH of ethanol extracts showed a higher than that of hot water extracts, among of which were showed the lowest pH 3.0 in Schizandra chinensis. The important factor of lipid oxidation were $Fe^{2+}$ ion and active oxygen, in which were bound by plant extracts in case of $Fe^{2+}$ ion existed. However, the hydroxyl radical scavenging ability of extracts were lowed, compared to extracts reacted with $Fe^{2+}$ ion. Among of them, the hydroxyl radical scavenging ability of Nameko and Pine needle extracts had a lower TBARS value than those of control. The iron content of extracts were less than 2.0 mg/100 g, but the total iron content of Schizandra chinensis extracts were 6.8 mg/100 g. The ethanol extracts of pine needle were higher than those of hot water extracts on the basis of $Fe^{2+}$ ion content. The ascorbic acid content of green tea showed 14.3 mg/100 g in hot water extracts and 16.7 mg/100 g in ethanol extracts. Electron donating ability of extracts showed more than 50%, except Nameko and allspices, which were higher in ethanol extracts than those of hot water extracts. The superoxide dismutase(SOD)-like activity of green tea showed 85.3% and 63.5% in hot water and ethanol extracts, respectively. The nitrite scavenging ability of green tea was the most effective in both extracts.

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.941-946
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• 2007

Bacillus halodurans O-methyltransferase (BhOMT) is a S-adenosylmethionine (SAM or AdoMet) dependent methyltransferase. Three dimensional structure of the BhOMT bound to S-adenosyl-L-homocysteine (SAH or AdoHcy) has been determined by comparative homology modeling. BhOMT has 40% sequence identity with caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) from alfalfa. Based on x-ray structure of CCoAOMT, three dimensional structure of BhOMT was determined using MODELLER. The substrate binding sites of these two proteins showed slight differences, but these differences were important to characterize the substrate of BhOMT. Automated docking study showed that four flavonoids, quercetin, fisetin, myricetin, and luteolin which have two hydroxyl groups simultaneously at 3'- and 4'-position in the B-ring and structural rigidity of Cring resulting from the double bond characters between C2 and C3, were well docked as ligands of BhOMT. These flavonoids form stable hydrogen bondings with K211, R170, and hydroxyl group at 3'-position in the Bring has stable electrostatic interaction with Ca2+ ion in BhOMT. This study will be helpful to understand the biochemical function of BhOMT as an O-methyltransferase for flavonoids.

• Food Engineering Progress
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• v.15 no.1
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• pp.6-14
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• 2011

The polysaccharides from fruit body of Auricularia auricula and Tremella fuciformis were extracted using hot water, and partially purified through ethanol precipitation and dialysis. Free radical scavenging activities of the crude and purified polysaccharides were examined and compared each other. Free radical scavenging activities of the partially purified polysaccharides were higher than those of crude polysaccharides. DPPH free radical, ABTS radical and SOD-like activities of partially purified polysaccharide at 1 mg/mL of concentration from A. auricula were 61.7, 9.6 and 38.9%, respectively, while those of T. fuciformis were 9.6, 5.7 and 15.3%, respectively. Results of site and non-site specific hydroxyl radical scavenging activities indicated that the partially purified polysaccharide fractions from A. auricula and T. fuciformis exhibited the hydroxyl radical scavenging effect by hydrogen donating ability and iron ion chelating ability. Also, reducing powers of A. auricula and T. fuciformis were 77.1 and 14.7% of BHT (0.1%) as standard, respectively. It was suggested that antioxidant activities of A. auricula were about 1.4~6.4 times higher than those of T. fuciformis due to different levels of polyphenol content.

• Environmental Engineering Research
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• v.24 no.1
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• pp.173-179
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• 2019

Prussian blue (PB) is known to be an effective material for radioactive cesium adsorption, but its nano-range size make it difficult to be applied for contaminated water remediation. In this study, a simple and versatile approach to immobilize PB in the supporting matrix via surface functionalization was investigated. The commercially available poly vinyl alcohol (PVA) sponge was functionalized by acrylic acid (AA) to change its major functional group from hydroxyl to carboxylic, which provides a stronger ionic bond with PB. The amount of AA added was optimized by evaluating the weight change rate and iron(III) ion adsorption test. The FTIR results revealed the surface functional group changing to a carboxyl group. The surface functionalization enhanced the attachment of PB, which minimized the leaching out of PB. The $Cs^+$ adsorption capacity significantly increased due to surface functionalization from 1.762 to 5.675 mg/g. These findings showed the excellent potential of the PB-PAA-PVA sponge as a cesium adsorbent as well as a versatile approach for various supporting materials containing the hydroxyl functional group.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7555-7563
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• 2015

The complex formation from Zn(II) ion and 2-(2-hydroxyethylamino)-2-(hydroxymethyl)-1,3-propanediol (Monotris), Bis(2-hydroxyethyl)imino-tris(hydroxymethyl)methane(Bistris) in aqueous solution at $25^{\circ}C$ and at an ionic strength of 0.10 M have been studied potentiometrically. For the Zn(II)-Monotris system, in the Monotris (L) complex $ZnL^{2+}$, one of the hydroxyl oxygen atoms as well as the amine nitrogen of the ligand are coordinated. In basic media, the coordinated hydroxyl group is deprotonated. For the Zn(II)-Bistris system, in the Bistris(L) complex $ZnL^{2+}$, two of the hydroxyl oxygen atoms as well as the amine nitrogen of the ligand are coordinated. In basic media, one of the coordinated hydroxyl groups is deprotonated. In very high basic media, an additional hydroxyl group undergoes deprotonation. The equilibrium constants for the formation of $ZnL^{2+}$, $ZnLH_{-1}{^+}$, $ZnLH_{-2}$, $Zn_2L_2H_{-2}{^{2+}}$ and $Zn_2L_2H_{-3}{^+}$ have been determined.

• Restorative Dentistry and Endodontics
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• v.27 no.6
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• pp.632-643
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• 2002

The purpose of this study was two-fold. First was to evaluate whether the molecular sieving model was appropriate for ionic dissociation experiment. Second was to compare the dissociation of calcium and hydroxyl ions from five types of calcium hydroxide pastes (Pure calcium hydroxide paste, DT temporary $dressing^{\circledR},{\;}Metapaste^{\circledR},{\;}Chidopex^{\circledR},{\;}Metapex^{\circledR}$) in three vehicles (aqueous, viscous and oily) and the antibacterial effect. Each calcium hydroxide pastes was placed into 0.65ml tube with cap and then 15% polyacrylamide gel was placed onto calcium hydroxide pastes. After the gel was hardened, the tubes were filled with tridistilled water (pH 7.14) and closed with cap. The tubes were stored in $37^{\circ}C$ 100% incubator The pH reading and the concentration of calcium ions were taken at 1, 4, 7. 10, and 14 days. The brain heart infusion agar plates with S. mutans and A. actinomycetemcomitans were used far antibacterial activity test. Middle of agar plate was filled with the calcium hydroxide pastes. The plates were incubated at $37^{\circ}C$ and observations were made to detect the zones of inhibition. These data were evaluated statistically by use of the analysis of variance and duncan test. The results were as follows. 1. In fresh mixing state, the pH of five types of calcium hydroxide pastes were measured between 12.5 and 12.8. 2. The pH was increased in all five types of calcium hydroxide pastes compared with control group. In 14 days, Pure calcium hydroxide paste (11.45) and DT temporary $dressing^{\circledR}$ (11.33) showed highest pH, followed by $Metapaste^{\circledR}$ (9.49), $Chidopex^{\circledR}$ (8.37) and $Metapex^{\circledR}$ (7.59) 3. Calcium was higher in all five types of calcium hydroxide pastes compared with control group. In 14 days, Pure calcium hydroxide paste (137.29 mg%) and DT temporary $dressing^{\circledR}$ (124.6 mg%) showed highest value, followed by $Metapaste^{\circledR}$ (116.74 mg%), $Chidopex^{\circledR}$ (111.84 mg%) and $Metapex^{\circledR}$ (60.22 mg%). 4. The zones of bacterial inhibition were seen around all five types of calcium hydroxide pastes. $Chidopex^{\circledR}{\;}and{\;}Metapex^{\circledR}$ groups which include iodoform were observed significantly larger zone of inhibition in A. actinomycetemcomitans compared with the other calcium hydroxide groups (p<0.05) However, $Metapex^{\circledR}$ showed the least antibacterial effect on S. mutans compared with other groups (p<0.05). The molecular sieving model was found to be acceptable in dissociation experiment of hydroxyl and calcium ions when compared with the previous tooth model study. But this model was not appropriate for the antibacterial test.