• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1915-1918
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• 2006

• Bulletin of the Korean Chemical Society
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• 제10권2호
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• pp.134-137
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• 1989

The reaction of $CpMo(CO)_3-M^+(M^+,\;Li^+,\;Na^+,\;K^+,\;PPN^{+a})$ with allyl halide was performed and the details of its counterion effects and solvent effect was investigated under the pseudo-first order conditions. The kinetic data from this reaction were compared with those from the reaction of the same anion with benzyl halides in terms of their inverse counterion effects.

• 환경위생공학
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• 제16권3호
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• pp.80-86
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• 2001

This research was carried out to investigate the effect of microscopic silica matrix coagulation on heavy metals and anion removal in mining wastewater. pH and alkalinity played an important role to coagulate heavy metals such as Al, and Fe and an anion such as ${SO_4}^{2-}$ with silica matrix as well as NaOH. However, the efficiency to form coagulates was much greater in silica matrix-treated wastewater than NaOH-treated one. Fe in wastewater formed coagulation with both silica matrix and NaOH treatments resulting in lowering Fe content in wastewater at above pH 9. For Al removal in wastewater, silica matrix-treated wastewater at above pH 12.3 formed stable coagulate with Al, while NaOH-treated one did not. Alkalinities of 89 and 220 mg/L were required to stabilize silica matrix treated coagulate with Fe and Al, respectively. Reaction time of ten minute was required to provide enough reaction for coagulation between heavy metals and silica matrix. Heavy metals and anion leachates were much lower in coagulate with silica matrix than that with NaOH, which indicates that silica matrix could be used to remove heavy metals efficiently.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.78-82
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• 2003

Development of hematite-coated sand was evaluated for the application of the PRB (permeable reactive barrier) in the arsenic-contaminated subsurface of the metal mining areas. The removal efficiency of As(III) and As(V), the effect of anion competition and the capability of arsenic removal in the flow system were investigated through the experiments of adsorption isotherm, arsenic removal kinetics against anion competition and column removal. Hematite-coated sand followed a linear adsorption isotherm with high adsorption capacity at low level concentrations of arsenic (< 1.0 mg/l). When As(III) and As(V) underwent adsorption reactions in the presence of anions (sulfate, nitrate and bicarbonate), sulfate caused strong inhibition of arsenic removal, and bicarbonate and nitrate caused weak inhibition due to specific and nonspecific adsorption onto hematite, respectively. In the column experiments, high content of hematite-coated sand enhance the arsenic removal, but the amount of the arsenic removal decreased due to the higher affinity of As(V) than As(III) and reduced adsorption kinetics in the flow system, Therefore, the amount of hematite-coated sand, the adsorption affinity of arsenic species and removal kinetics determined the removal efficiency of arsenic in the flow system. arsenic, hematite-coated sand, permeable reactive barrier, anion competition, adsorption.

• Journal of Pharmaceutical Investigation
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• 제36권4호
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• pp.283-286
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• 2006

The present study aimed to investigate the interaction of nucleoside analogs with human organic anion transporter 1 and 3(hOAT1 and hOAT3) that play a primary role in the tubular uptake of endogenous and exogenous organic anions in the kidney. The interactions of ddC, ara-C, ara-A and ara-U with hOAT1 and hOAT3 were examined using MDCK cells stably overexpressing hOAT1 or hOAT3. Among the tested drugs, ddC showed the highest affinity to hOAT1 with $IC_{50}$ values of 5.2 mM, while ara-A, ara-C and ara-U weakly inhibited the cellular uptake of $[^3H]-PAH$ in MDCK-hOAT1 cells at 1 mM. In contrast, all the tested drugs did not have any inhibition effect on the cellular uptake of $[^3H]-estrone$ sulfate in MDCK-hOAT3 cells over the drug concentration of 0.01-2 mM, implying that they might not interact with hOAT3. Taken all together, the present study suggests that hOAT1 could weakly interact with nucleoside analogues such as ddC, ara-C, ara-A and ara-U but the interaction with hOAT3 during the urinary excretion of these nucleoside analogues may be negligible in the kidney.

• 한국토양비료학회지
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• 제49권5호
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• pp.541-547
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• 2016

In this experiment we investigated the influence of various anions including oxalic acid encountered as solution phase in soil on the adsorption and desorption of sulfate in Chungwon Bt soil. The effect of chloride and nitrate on the adsorption of sulfate was not significant, suggesting that sulfate was better able to compete for adsorption sites at concentrations studied, in contrast to the large reduction in the amount of chloride adsorbed in the presence of sulfate. The results of competition for sorption sites between sulfate and anion showed that the simultaneous presence of two anions in solution was effective in reduction of competing anion at a maximum value of adsorption, due to the similar adsorption mechanism for anion competition. Therefore, the variation in the buffer power of the acids will produce a change in the strength and amount of adsorption and the competitive ability.

• Archives of Pharmacal Research
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• 제26권7호
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• pp.511-515
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• 2003

Quinazolinones, 2-substituted and 3-substituted, mainly synthesized by microwave irradiation, were subjected to anti-platelet aggregation and inhibition of superoxide anion generation assays. Interestingly, 2-phenyl-4-quinazolinone (4) exhibited significant inhibitory activities toward platelet aggregation and neutrophil activation, and it might therefore serve as a prototype lead compound.

• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.2093-2097
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• 2009

Novel fluorescent anion chemosensors based on anthracene-isothiouronium derivatives were synthesized. Isomerism due to the intramolecular mobility in these isothiouronium salts was detected by $^1H$ NMR spectroscopy. The effect of the substituent, temperature and solvent on the isomerism was also examined. The anthracene-isothiouronium sensor showed significant fluorescent enhancement upon the addition of various anions such as fluoride, acetate, and dihydrogen phosphate, even in the presence of water.

• Journal of Photoscience
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• 제3권2호
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• pp.71-76
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• 1996

Anil K. Singh, Mrunalini M. Kapil, Department of Chemistry, Indian Institute of Technology Bombay - 400076, INDIA Purple membrane (PM, $\lambda$$_{max}$ 570 nm) of H. halobium on treatment with sulphuric acid changes its colour to blue ($\lambda$$_{max}$ 608 nm). The purple chromophore can be regenerated from the blue chromophore by exogeneous addition of anions such as CI$^-$ and HPO$_4^{2-}$. Chloride ion is found to be more effective than the dibasic phosphate ion in regenerating the purple chromophore. Nevertheless, one thing common to the anion regeneration is that both CI$^-$ and HPO$_4^{2-}$ show marked pH effect. At pH 1.0 the efficiency of regeneration of the purple chromophore is greater than at pH 2.0, for the same anion concentration. Fluorescence and circular dichroic studies indicate that the proteins do not undergo drastic changes at the secondary' or tertiary structure level and the native structure is preserved during this transition. However, chromophoric-site interactions between retinal and the apoprotein are affected during this colour transition. A molecular mechanism is advanced for this transition.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1531-1537
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• 2004

Twenty four thiol-functionalized ionic liquids based on imidazolium cation, 1-(12-mercaptododecyl)-3-alkylimidazolium salts, have been synthesized, and utilized to investigate the effects of alkyl-chain length and anion on the wettability of Au surfaces on the basis of self-assembled monolayers presenting [(CnSAMIM)X], where n = 1-6, X = Br, $BF_4$, $PF_4$ and $NTf_2$. Water wettabilities of the surfaces were measured as a water contact angle by contact angle goniometry. It was found that water wettability of the Au surfaces coated with imidazolium ions was largely dependent not only on counter anions but also on the length of alkyl chains. In the case of SAMs of N-alkylimidazolium ions having short length of N-alkyl chain (C1-$C_4$), anions played great role in determining water wettability of the surfaces.