• Bulletin of the Korean Chemical Society
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• v.5 no.4
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• pp.149-153
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• 1984

Reactions of $MoOCl_5^{2-}$ with ${\alpha}_2-[P_2W_{17}O_{61}]^{10-}$ have been studied spectrophotometrically and several complexes have been identified. The transient species initially formed is probably $[Mo_2O_4(P_2W_{17}O_{6l})_2]^{18-}$. At $pH {\le} 3$the visible spectrum changes gradually, indicating formation of a transient isomer of $[P-2Mo^VW_{17}O_{62}]^{7-}$, which again transforms into the stable isomer. The transient isomer absorbs light much more strongly than the stable isomer in the visible range. At $pH > 3 [P_2W^VW_{16}O_{61}]^{11-}$ is formed probably via the transient isomer of $[P_2Mo^VW_{17}O_{61}]^{7-}$.

• Bulletin of the Korean Chemical Society
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• v.5 no.2
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• pp.65-68
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• 1984

Reactions of $MoOCl_5^{2-}$ with $[PW_{11}O_{39}]^{7-}\;and\;[SiW_{11}O_{39}]^{8-}$ have been studied spectrophotometrically and several transient complexes have been discovered. Transient species initially formed are probably $[Mo_2O_4(PW_{11}O_{39})_2]^{12-}\;and\;[Mo_2O_4(SiW_{11}O_{39})_2]^{14-}$. Spectra change gradually, indicating formation of transient isomers of $[PMoW_{11}O_{40}]^{4-}\;and\;[SiMoW_{11}O_{40}]^{5-}$, which again transform into the stable isomers. The transient isomers absorb light much more strongly than the stable isomers in the visible range.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.589-597
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• 2016

There are a number of industrial complexes which could be a source of heavy metal (loid)s contamination of arable soil in Gyeongnam province of South Korea. Heavy metal (loid)s accumulation of plant is more related to the concentration of plant available heavy metal (loid)s in arable soil than that of total heavy metal (loid)s. The objectives of this study were 1) to examine heavy metal concentrations in soils located near industrial complexes in Gyeongnam province and 2) to determine the relationship between concentration of plant available heavy metal (loid)s and chemical properties of soil. Soil samples were collected from 85 sites of arable lands nearby 7 industrial complexes in Gyeongnam province. Total heavy metal (loid)s concentration, available heavy metal (loid)s concentration, and chemical properties of collected soils were measured. The mean concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in the soils were $5.8mg\;kg^{-1}$, $1.3mg\;kg^{-1}$, $0.03mg\;kg^{-1}$, $51.5mg\;kg^{-1}$, and $68.7mg\;kg^{-1}$, respectively. Total concentration of Cd and Zn in arable soil located near ${\nabla}{\nabla}$ industrial complex exceeded the warning criteria ($4mg\;kg^{-1}$ and $300mg\;kg^{-1}$ for Cd and Zn, respectively) as described by in the soil environmental conservation Act of Korea. The concentration of plant available heavy metal (loid)s was negatively related to the soil pH and available Pb and Zn concentrations had relatively high correlation coefficient when compared with other heavy metal (loid)s. The concentration of plant available Pb and Zn was negatively related to that of organic matter (OM). Based on the above results, it might be a good soil management to control pH and OM concentration with soil amendments such as lime and compost to reduce phytoavailability of heavy metal (loid)s in arable soil located near industrial complex.

• Microbiology and Biotechnology Letters
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• v.12 no.4
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• pp.277-283
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• 1984

In the forward reaction (ADP formation) of the adenylate kinase from baker's yeast, dissociation constants from binary complexes are higher by a factor of about 4 times then those from at ternary complexes. In the reverse reaction, dissociation constants from the binary complexes are 2 times higher then those from the ternary complexes. The enzyme showed activities against various nucleotide triphospate in following orders; ATP 100, UTP 18, ITP 9 and GTP 5, of the necleotide monophosphate. only dAMP showed 33% activity of that AMP as phosphate acceptor. Divalent cations were required in enzyme reaction in following orders; $Mg^{2＋}$ 100, Co$^{2＋}$ 57, Mn$^{2＋}$ 54, $Ca^{2＋}$ 51, Ni$^{2＋}$ 10 and Sn$^{2＋}$ 6. AMP, as a substrate inhibitor, competitively inhibited the adenylate kinase at pH 7.2 or 8.0. Inhibition constants of the enzyme showed greater dependence on the pH of the reaction mixture, which was the lower Ki values under higher pH. Adenosine pentaphospho adenosine was competive inhibitor to the enzyme against all substrate, and it showed the same Ki values, 2.9mM. Further, PEP was competive inhibitor with respect to AMP and non-competive inhibitor with respect to MgATP. Adenylate kinase from bakers yeast was similar to mitochondrial type of animal in the contents of aianine, leucine and asparagine or asparatic acid differing from muscle type enzyme. Based on the results and observation, characteristic of yeast adenylate kinase resembled the adenylate kinase of mitochondrial type from animals. Further, difference of characteristics in adenylate kinasa depending upon the workers might be due to the difference of strain used.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1314-1318
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• 2010

The $[Ru(tpy)_2]Cl_2$ (tpy:2,2':6',2"-terpyridine) complex was synthesized and its structure was confirmed by $^1H$-NMR and elemental analysis. Its binding mode toward DNA was compared with the well-known $[Ru(bpy)_3]Cl_2$ (bpy:2,2-bipyridyl), using isotropic absorption, linear dichroism(LD) spectroscopy, and an energy minimization study. Compared to $[Ru(bpy)_3]^{2+}$, the $[Ru(tpy)_2]^{2+}$ complex exhibited very little change in its absorption pattern, especially in the MLCT band, upon binding to DNA. Furthermore, upon DNA binding, both Ru(II) complexes induced a decrease in the LD magnitude in the DNA absorption region. The $[Ru(tpy)_2]^{2+}$ complex produced a strong positive LD signal in the ligand absorption region, which is in contrast with the $[Ru(bpy)_3]^{2+}$ complex. Observed spectral properties led to the conclusion that the interaction between the ligands and DNA bases is negligible for the $[Ru(tpy)_2]^{2+}$ complex, although it formed an adduct with DNA. This conclusion implies that both complexes bind to the surface of DNA, most likely to negatively charged phosphate groups via a simple electrostatic interaction, thereby orienting to exhibit the LD signal. The energy minimization calculation also supported this conclusion.

• 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.

• IMMUNE NETWORK
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• v.4 no.3
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• pp.131-142
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• 2004

In recent years, adjuvants have received much attention because of the development of purified subunit and synthetic vaccines which are poor immunogens and require adjuvants to evoke the immune response. Therefore, immunologic adjuvants have been developed and testing for most of this century. During the last years much progress has been made on development, isolation and chemical synthesis of alternative adjuvants such as derivatives of muramyl dipeptide, monophosphoryl lipid A, liposomes, QS-21, MF-59 and immunostimulating complexes (ISCOMS). Biodegradable polymer microspheres are being evaluated for targeting antigens on mucosal surfaces and for controlled release of vaccines with an aim to reduce the number of doses required for primary immunization. The most common adjuvants for human use today are aluminum hydroxide and aluminum phosphate. Calcium phosphate and oil emulsions have been also used in human vaccination. The biggest issue with the use of adjuvants for human vaccines is the toxicity and adverse side effects of most of the adjuvant formulations. Other problems with the development of adjuvants include restricted adjuvanticity of certain formulations to a few antigens, use of aluminum adjuvants as reference adjuvant preparations under suboptimal conditions, non-availability of reliable animal models, use of non-standard assays and biological differences between animal models and humans leading to the failure of promising formulations to show adjuvanticity in clinical trials. The availability of hundreds of different adjuvants has prompted a need for identifying rational standards for selection of adjuvant formulations based on safety and sound immunological principles for human vaccines. The aim of the present review is to put the recent findings into a broader perspective to facilitate the application of these adjuvants in general and experimental vaccinology.

• Applied Biological Chemistry
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• v.2
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• pp.45-52
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• 1961

The decomposition of malathion in dust for mulations prepared from four Korean tales as carriers during storage period has been studied. Amberlite CG-120, a cation exchange resin . which has higher cation exchange capacity than tales, was also used as a carrier in hope of finding out the effect of nagative charge upon the decomposition of malathion. Besides the original talc powders obtained directly from the mines, the hydrogen ion saturated forms were also used as carriers for comparisonal study. The saturated ions for the resin were hydrogen, sodium and magnesium. As the physical properties of the tales, colloid content, water adsorption capacity, PH, specific surface, phosphate fixing capacity and exchangeable canons were determined, and these properties were correlated with the amount of the decomposition. Following results were obtained from the experiment. 1. The malathion in the talc in dust was found to decompose around 10-15% ofthe total withina month. About 50% of the decom position that took place after a month was found to occur within a week. 2. The resin which has higher cation exchange capacity than the tales was highly effective in the decomposition of malathion compared with the tales. 3. In every case the saturation of the exchange complexes with hydrogen ion greatly accelerated the decomposition of malathion. 4. The most highly correlated physical properties with the decomposition were colloid content and specific surface of the tales. 5. The water adsorption and phosphate fixing capacities of the tales were found not to correlate with the amount of malathion decomposed. From the experimental results it was concluded that the active negative spots on the colloidal tales or the resin attract the electropositive phosphorus atom in a malathion molecule thereby inducing the decomposition easier. The presence of hydrogen ion nearby might cause a catalytic effect in the decomposition of malathion.

• KSBB Journal
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• v.21 no.2
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• pp.151-156
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• 2006

Vitamin-C is one of the typical bioactive substances widely used in the cosmetic and pharmaceutical applications. It is well known that the bioavailability of vitamin-C decreases with time because it is spontaneously oxidized in the presence of oxygen. In this study, vitamin-C inclusion complexes were prepared by formulating vitamin-C with 2-hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD) to protect vitamin-C from being oxidized. Vitamin-C inclusion complexes were prepared by a solvent evaporation method using a rotary evaporator and various solvents of different dielectric constant such as ethanol, methanol and distilled deionized water to investigate the effect of solvent polarity on the stability of vitamin-C. To estimate the stability of inclusion complexes, samples were stored in a 50 mM phosphate buffer solution of pH 7.0 for 24 hours at $25{\pm}0.1^{\circ}C$ and the degradation rate of vitamin-C was calculated using a high performance liquid chromatography. The stability of vitamin-C was observed to improve with the increase of solvent polarity.

• BMB Reports
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• v.36 no.6
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• pp.597-602
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• 2003

Acid phosphatases (APases) play a role in the release of phosphate in organic complexes in soil. We investigated tissue- and isoform-specific responses of APases to phosphorus (P) deficiency in three rice genotypes; Dasan-byeo, Sobi-byeo, and Palawan. The levels of shoot APase activity per protein were similar in the three genotypes. They significantly decreased with P deprivation that was longer than seven days. Root APase activity per protein was two- to three-fold higher in Dasan than in Sobi and Palawan. In all genotypes the APase activity increased in P-deficient plants, but the increase was higher in Sobi and Palawan. After 21 days of P deprivation, secreted APase activity increased more than eight-fold in Dasan and two-fold in Sobi and Palawan. Isoform profiles of shoot and root APases were most diverse in Dasan. The activities of the major isoforms in P-deficient shoots decreased in all three genotypes. Depending on the genotypes, further increases in constitutive isoforms and new induction of one to four isoforms occurred in P-deficient roots. The results indicate that tissue and genotype differences in the response of APase to P deficiency are primarily facilitated by the different responses of the isoforms.