• YAKHAK HOEJI
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• v.3 no.1
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• pp.4-9
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• 1957

Effects of antibioties on micro-organism have been reported by many scientists, such as Krampitz and Werkman, Fisher, Gale and Rodwell, Klimick Cavalito and Bailey, Umbreit, etc. On the mechanism by which penicillin act, Fisher(1947), Platt(1947), and Cavallito, considered that penicillin might act on bacteria by inhibiting with the normal function of SH-group of glutathione in the metabolism of the cell. Resenbrance of penicillin to gultathione in structure and the inactivation of penicillin by cysteine make us approve of the above inhibiting theory of SH-group. Galland (1947) and Schmidt (1947) reported that penicillin inhibited the activity of ribonuclease, Phosphatase, and mononucleotidase. Gale (1948) discovered that the gram positive bacteria had lost the power to uptake glutamic acid by ribonucleic acid in the medium contained penicillin: growth of gram positive organism was inhibited by the results that penicillin inhibited the uptake of amino acid byribonucleic acid, acting on ribonucleic acid of gram positive bacteria. Hotchkiss (1950) cultured S. aureus in the medium contained glucose and amino acids, and studied the effect of penicillin on protein synthesis. Peptide formation in living cells was inhibited by penicillin, while amono acid was utilized as before the addition of penicillin. On the otherhand, Binkley (1951) found penicillin interfered hydrolase of glutath one, and Hans (1950) reported penicillin inhibited the transpeptidation. On the machanism by which streptomycin acts. Cohen (1947) reported steptomycin made a irreversible complex with desoxyribonucleic acid, by the fact that desoxyribonucleic acid formed the precipitates with diguanide group of steptomycin. Zeller (1951) reported, on the other hand, streptomycin inhibited diamine oxidease. Geiger (1947) and Umbreit (1949) reported that steptomycin inhibited condensation of oxaloacetate and pyruvate in E. Coli and Oginsky et al (1949) reported steptomycin inhibited oxaloacetate-pyruvate reaction in Kreb's cycle. On the mechanism by which terramycin acts, Hahn & Wisseman (1951) reported that the formation of adaptive enzyme was inhibited by terramycin in E. Coli cultivated in the medium contained loctose, and that the protein synthesis was inhibited by terramycin. However, effects of antibiotics on amino acid metabolism have not been discussed much in spite of its important role in living cells. Especislly, effects of anitibiotics on higher plants have scarcely been reported. Here, to prove the effect of antibiotics on higher plants, and the mechanism by which, through amino acid metabolism, they promote or inhibit growth of plants, amino acids in bean plants treated with penicillin, streptomycin, and terramycin were analyzed by paper chromatography. And to clarify the antagonis of cysteine (as SH-group) against penicillin, through amino acid metabolism, amino acids in bean plants treated with cystene and penicillin, at the same time, were also analyzed.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.301-310
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• 2003

The purpose of this study is to evaluate the biocompatibility and the biorsorbability of several types of calcium polyphosphate made through change of manufacturing process for 12 month. To solve limitation of calcium phosphate, we developed a new ceramic, Calcium Polyphosphate(CPP), and report the biologic response to CPP in extraction sites of beagle dog. Porous CPP blocks were prepared by condensation of anhydrous $Ca(H_2PO_4)_2$ to form non-crystalline $Ca(PO_3)_2$ and then milled to produce CPP powder. CPP powder, CPP block, and CPP granules added with $Na_2O$ were implanted in extraction sockets and histologic observation were performed at 12 months later. Like 3 months results, histologic observation at 12 months revealed that CPP matrix were mingled with and directly apposed to new bone without any adverse tissue reaction, CPP powder show direct bony contact, but new bone formation and fibrous tissue encapsulation showed in CPP block. 10% $Na_2O$ CPP granules show more inflammatory cells infiltration around graft materials compared at 3 month, but 15% $Na_2O$ CPP granules show less. This result revealed that regardless of addition of $Na_2O$, CPP had a high affinity for bone and had been resorbed slowly. From this results, it was suggested that CPP is promising ceramic as a bone substitute and addition of $Na_2O$ help biodegradation but optimal concentration of $Na_2O$ and other additive component to increase degradation rate should be determined in further study.

• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.428-435
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• 1988

Some nickel(Ⅱ) and palladium(Ⅱ) complexes of the ambidentate ligands derived from condensation of the isonitrosoacetylacetone and various diamines, $Ni(IAA)_2-en$, $Ni(IAA)_2-pn$, $Ni(IAA)_2-tn$, $Pd(IAA)_2-en$, PdCl(IAA)-pn, and $Pd(IAA)_2$-tn, where (IAA)$_2$-en, $(IAA)_2$-tn, and (IAA)-pn represent N,N'-enthylenbis(isonitrosoacetylacetone imine), N,N'-propylenebis(isonitrosoacetylacetone imine), N,N'-trimethylenebis(isonitrosoacetylacetone imine) and N-(2-aminopropyl)isonitrosoacetylacetone imine, respectively, have been prepared. The nickel(Ⅱ) and palladium(Ⅱ) complexes were characterized on the bases of the elemental analysis, IR, NMR, and electronic spectra. It is suggested that a isonitroso group of (IAA)$_2$-en or (IAA)$_2$-tn coordinates to the metal ion through the nitrogen atom to form five-membered ring, while the other isonitroso group of (IAA)$_2$-en or (IAA)$_2$-tn coordinates to the metal ion through the oxygen atom to form six membered ring in square-planar complexes of Ni(IAA)$_2$-tn and Pd(IAA)$_2$-en. And two isonitroso groups of (IAA)$_2$-en, (IAA)$_2$-pn, or (IAA)$_2$-tn coordinate to the metal ion through the nitrogen atom to form five-membered rings in square-planar complexes of Ni(IAA)$_2$-en, Ni(IAA)$_2$-pn, and Pd(IAA)$_2$-tn. On the other hand, square-planar PdCl(IAA)-pn is formed by the reaction of propylenediamine with a isonitrosoacetylacetone in the presence of palladium(Ⅱ)ion.

• Corrosion Science and Technology
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• v.9 no.4
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• pp.147-152
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• 2010

Conventional paints for conversion coating applications in steel production derived mainly from water-based polymer dispersions containing several additives actually show good general performance, but suffer from poor scratch and abrasion resistance during use. The reason for this is because the relatively soft organic binder matrix dominates the mechanical surface properties. In order to maintain the high quality and decorative function of coated steel sheets, the mechanical performance of the surface needs to be improved significantly. In fact the wear resistance should be enhanced without affecting the optical appearance of the coatings by using appropriate nanoparticulate additives. In this direction, nanocomposite coating compositions (Nanomer$^{(R)}$) have been derived from water-based polymer dispersions with an increasing amount of surface-modified nanoparticles in aqueous dispersion in order to monitor the effect of degree of filling with rigid nanoparticles. The surface of nanoparticles has been modified for optimum compatibility with the polymer matrix in order to achieve homogeneous nanoparticle dispersion over the matrix. This approach has been extended in such a way that a more expanded hybrid network has been condensed on the nanoparticle surface by a hydrolytic condensation reaction in addition to the quasi-monolayer type small molecular surface modification. It was expected that this additional modification will lead to more intensive cross-linking in coating systems resulting in further improved scratch-resistance compared to simple addition of nanoparticles with quasi-monolayer surface modification. The resulting compositions have been coated on zinc-galvanized steel and cured. The wear resistance and the corrosion protection of the modified coating systems have been tested in dependence on the compositional change, the type of surface modification as well as the mixing conditions with different shear forces. It has been found out that for loading levels up to 50 wt.-% nanoparticles, the mechanical wear resistance remains almost unaffected compared to the unmodified resin. In addition, the corrosion resistance remained unaffected even after $180^{\circ}$ bending test showing that the flexibility of coating was not decreased by nanoparticle addition. Electron microscopy showed that the inorganic nanoparticles do not penetrate into the organic resin droplets during the mixing process but rather formed agglomerates outside the polymer droplet phase resulting in quite moderate cross linking while curing, because of viscosity. The proposed mechanisms of composite formation and cross linking could explain the poor effect regarding improvement of mechanical wear resistance and help to set up new synthesis strategies for improved nanocomposite morphologies, which should provide increased wear resistance.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.381-388
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• 1974

When mixture of p-phenylenediamine (PPD) and m-aminophenol (MAP) were reacted with formaldehyde (F) varying their amounts under $N_2$ stream at the temperature of -5∼0$^{\circ}$, addition condensation reaction occurred and brown colored resins(in some cases orange colored) were formed immediately. All resins thus formed were insoluble in most ordinary organic solvents and did not melt up to 300$^{\circ}$. When the resins were treated with dilute(7 %) aqueous sodium hydroxide solution, the adsorptivity of methylene blue on them showed marked improvement reaching as much as 80 mg of methylene blue on 1 g of the resin. On the other hand, in the case of bromophenol blue, its amount of adsorption appeared 250 mg per 1 g of the resin. The TGA under $N_2$ atmosphere indicated that the resin formed in molar ratio of 1 : 3 : 8 (PPD : MAP : F) showed the best heat-resistant property among others. About 40 % weight loss was observed for this resin at 900$^{\circ}$ with heating rate of 2$^{\circ}$ per minute.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.121-126
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• 2003

Tris(2-cyclohexylaminoethyl)amine (L) was synthesized by the Schiff base condensation reaction of tris(2-aminoethyl)amine with cyclohexanone, followed by reduction. The thermodynamic characteristics, mole ratio and formation constant of [Zn(II)-L] complex were measured by the cyclic voltammetry and isothermal titration. In the case of Zn(II), well-defined cathodic and anodic peak were obtained at -1.02V and -0.48V vs Ag/AgCl , respectively. For the [Zn(II)-L] complex, both peaks were obtained at -1.19V and -0.45V vs Ag/AgCl, respectively. In addition, the peak height gradually increases as the scan rate increases, suggesting that the currents obtained were diffusion - controlled. The mole ratio and stability constant of the complex measured cyclic voltammerty were 1:1 and logK$_f$= 5.8, respectively. And the mole ratio and stability constant of the complexe calculated by isothermal titration method was 1:1 and logK =5.4, respectively. ${\Delta}$H, ${\Delta}$G and T${\Delta}$S for the complex formation were -53.0 kJ/mol, -31.1 kJ/mol, and -21.9 J/K at 25 ${\circ}$C, respectively.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.418-424
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• 2016

This study is an experimental study on the recycling of bottom ash in coal ash discharged from a thermal power plant. Bottom ash has limited research on recycling because it has more porous and higher water absorption ratio than fly ash. In this paper, the bottom ash was pulverized to a specific surface area of $4,000cm^2/g$ in order to use as a binder, and the flow, compressive strength test and microstructure analysis of the bottom ash based geopolymer mortar were performed. The flow measurement results of the geopolymer mortar showed that the flow rate was improved by increasing mixing water as the molar concentration of activator was increased. Compressive strength increased with increasing curing temperature and molar concentration. Through the microstructure analysis, we could confirm the geopolymer gel produced by the reaction of the condensation polymerization. It is considered that it is possible to make the bottom ash based geopolymer concrete through proper molar concentration of activator and high temperature curing.

• Journal of Periodontal and Implant Science
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• v.31 no.3
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• pp.555-564
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• 2001

The purpose of this study is to evaluate the bioresorbability of Calcium Polyphosphate added with $Na_2O$ and chitosan. Though calcium phosphate ceramics meet some of the needs for bone replacement, they have some limitation of unresorbability and fibrous encapsulation without direct bone apposition during bone remodelling. To solve these problem, we developed a new ceramic, calcium polyphosphate(CPP), and report the biologic response to CPP in extraction sites of beagle dog. Porous CPP granules were prepared by condensation of anhydrous $Ca(H_2PO_4)_2$ to form non-crystalline $Ca(PO_3)_2$. CPP granules added with $Na_2O$ and chitosan were implanted in extraction sockets and histologic observation were performed at 12 weeks later. Histologic observation at 12 weeks revealed that CPP matrix were mingled with and directly apposed to new bone without any intervention of fibrous connective tissue. CPP granules added with chitosan were well adatped without any adverse tissue reaction and resorbed slowly and spontaneously. CPP granules added with $Na_2O$ and chitosan show multinucleated giant cells and osteoblast-like cells around grafted material and newly formed bone. This result revealed that CPP, regardless of its additive component, had a high affinity for bone and had been resorbed slowly. From this results, it was suggested that CPP is promising ceramic as a bone substitute and addition of $Na_2O$ and chitosan help biodegradation. In further study , it will be determined which concentration of $Na_2O$ help biodegradation and the other additive components increase the degradation rate.

• Journal of the Korean Chemical Society
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• v.21 no.1
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• pp.60-66
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• 1977

In the addition condensation reaction of m-phenylenediamine(MPD) and resorcinol (RES) with formaldehyde, the suspension polymerization in liquid paraffin was performed and the bead polymers were obtained with good results. The polymers were treated with dilute aqueous sodium hydroxide solutions in order to improve the adsorption capacity to the metallic ions and the adsorptivity to the several metallic ions, such as $Cd^{2+},\;Pb^{2+},\;Al^{3+},\;Mg^{2+},\;Co^{2+},\;and\;Hg^{2+}$ of the alkali-treated and untreated polymers were tested. These MPD-RES-F type resins showed better adsorption capacity to the heavy metallic ions such as $Cd^{2+}\;and\;Hg^{2+}$ than the light metallic ions such as $Pb^{2+},\;Al^{3+}\;and\;Mg^{2+}$, and the treatment of the resins with about 20 percent aqueous sodium hydroxide solution showed significant improvement of the adsorption capacity to the metallic ions in all cases.

• Polymer(Korea)
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• v.36 no.4
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• pp.427-433
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• 2012

A series of poly(imide-aramid-sulfone)s with alternatingly introduced imide/aramid groups were prepared by reacting divinyl sulfone (DVS) and $N^1,N^4$-bis(4-(vinylsulfonyl)phenyl)terephthalamide (2) with pyromellitic diimide. Three model compounds, N-[2-(p-aminophnenylsulfonyl)ethyl]phthalimide (3), 2,2'-(2,2'-sulfonylbis(ethane-2,1-diyl))diisoindoline-1,3-dione (4), and N,N-bis(4-(2-(1,3-dioxoisoindolin-2-yl)ethylsulfonyl)phenyl)terephthalamide (5), resembling polymers were prepared with good yields by reacting p-aminophenyl vinyl sulfone, DVS, and 2 with phthalimide. Condensation polymerization was carried out by Michael-type addition reaction of the difunctional phthalimide group with the DVS group in the presence of tetrabutylammonium hydroxide (TBAH), resulting in poly(imide-aramid-sulfone)s 6-12 with moderate molecular weights and good yields. They were highly soluble in polar solvents such as N,N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidinone and tetrahydrofuran. The ratios of DVS/2 were 1/0, 3/1, 2/1, 1/1, 1/2, 1/3, and 0/1. Molecular weight and physical properties such as solubility, viscosity, and thermal properties of the polymers were examined.