• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.593-602
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• 2010

Chitosan as a natural polymer has superior physicochemical properties such as biocompatibility, biodegradability and nontoxicity, but application of chitosan for therapy of cancer and gene related-disease has been limited by poor solubility in aqueous solution. Therefore, low molecular weight water-soluble chitosan (LMWSC) with high reactivity and strong positive charge can be applied as a delivery system having function to carry in the specific tissue the bioactive material like poor solubility drug, or therapeutic gene and developed as a therapeutic system having good therapeutic efficiency. The most important factor for therapy of various diseases is to reveal the antigen or receptor expressed in specific lesion tissue and the antibody and ligand which can bind with antigen is to introduce at the biomaterials for enhancement the therapeutic efficiency. The studies for cationic synthetic polymer as drug or gene delivery have been actively performed, but it has many problems such as toxicity in the body, therapeutic efficiency. From this point of view, this article demonstrated the introduction of functional groups to target the specific tissue and therapeutic strategy using the modification of LMWSC with free-amine group. The development of these delivery system will provide a positive vision for cancer therapy.

• Analytical Science and Technology
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• v.31 no.2
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• pp.96-105
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• 2018

This study aimed to improve the method for detecting eight secondary aliphatic amines (SAAs), so as to measure their concentrations in fresh water and tap water samples. NaOH (8 mL, 10 M) and benzenesulfonyl chloride (2 mL) were added to a water sample (200 mL), and the mixture was stirred at $80^{\circ}C$ for 30 min. An additional NaOH solution (10 mL) was added and the stirring was continued for another 30 min. The pH of the cooled mixture was adjusted to 5.5-6.0 by adding HCl (35 %), and the SAAs were extracted using dichloromethane (50 mL). This extraction was repeated once. The extract was then washed with $NaHCO_3$ (15 mL, 0.05 M) and dried over $Na_2SO_4$ (4 g). The extract was finally concentrated to 0.1 mL, of which $1{\mu}L$ was analyzed for SAAs by GC-MS. The linearity of the spike calibration curves was high ($r^2=0.9969-0.9996$). The detection limits of the method ranged from 0.01 to $0.20{\mu}g/L$, and its repeatability and reproducibility (expressed as relative standard deviation) were both less than 10 % (6.6-9.4 %). Its accuracy (measured in percentage error) ranged between 2.4 % and 6.1 %. The established method was applied to the analysis of five surface water and 82 tap water samples. Dimethylamine was the only SAA detected in all the water samples, and its average concentration was $0.79{\mu}g/L$ (range: $0.20-2.54{\mu}g/L$). Therefore, this study improved the analytical method for SAAs in surface water and tap water, and the regional and seasonal concentration distributions were obtained.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.935-941
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• 1998

New type of chitosan deriertives was synthesised by graft copolymerization of mono(2-methacryloyl oxyethyl) acid phosphate into chitosan. The reaction conditions showing the highest percentage of grafting were an initiator concentration of $3.5{\times}10^{-3}M$, monomer concentration of 0.19 M, and reaction temperature of $40^{\circ}C$, while rate of grafting showed same value after elapsing 4hours of reaction time. The antifungal activity of chitosan depending on content of free amine and kind of monomer was examined against Candida albicans, Trichophyton rubrum and Trichophyton uiolaceum by shake flask method. The pH value of buffer solution to show the highest antifungal activity was 5.75, and the selectivity of mold strain was observed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.2
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• pp.48-62
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• 1997

Chitosan oligosaccharides having aldehyde group at reducing end were prepared by oxidative-deamination reaction of chitosan by using sodium nitrite, and the resulting aldehyde group was reduced to 2, 5-anhydro-D-mannitol group. The obtained chitosan oligosaccharides showed an average degree of polymerization 2~3 by gel permeation chromatography analysis. It was highly soluble in hydrophilic solvents and thermally stable. N, N-diacyl, O-acyl chitosan oligosaccharides were obtained from the reaction between chitosan oligosaccharides and acyl chloried under dimethylaminopyridine. From differential scanning calorimetric measurement, N, N-dilauroyl, O-lauroyl chitosan oligosaccharides showed mesophase region, which was confirmed by polarized microscope as a thermotropic liquid crystalline state. X-ray diffraction pattern revealed that N, N-dilauroyl, O-lauroyl chitosan oligosaccharedes were highly crystalline, whereas chitosan oligosaccharides were not.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.575-584
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• 2007

The adsorption capability of iron phthalocyanine derivatives were investigated by means of X-ray diffractometor (XRD), IR (infrared) spectroscopy, scanning electron microscopy (SEM) and temperature programmed desorption (TPD). According to TPD results, iron phthalocyanine derivatives showed two desorption peaks at low temperature ($100{\sim}150^{\circ}C$) and high temperature ($350{\sim}400^{\circ}C$) indicating that there were two kinds of acidities. Tetracarboxylic iron phthalocyanine (Fe-TCPC) have a stronger desorption peak (chemical adsorption) at the high temperature and a weaker desorption peak (physical adsorption) at the low temperature than iron phthalocyanine (Fe-PC). The specific surface areas of Fe-TCPC and Fe-PC were $26.46\;m^2/g\;and\;11.77\;m^2/g$, respectively. The pore volumes of Fe-TCPC and Fe-PC were $0.14\;cm^3/g\;and\;0.06\;cm^3/g$, respectively. The adsorption capability of triethyl amine calculated by breakthrough curve at 220 ppm of equilibrium concentration was 29.2 mmoL/g for Fe-TCPC and 0.8 mmoL/g for Fe-PC. The removal efficiency of dimethyl sulfide of Fe-TCPC and Fe-PC in batch experiment of 225 ppm of initial concentration were 44.9% and 28.9%, respectively. The removal efficiency of trimethyl amine of Fe-TCPC and Fe-PC in batch experiment of 118 ppm of initial concentration were approximately 100.0% and 33.9%, respectively.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.507-512
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• 2000

A new copper(II) complex, Cu(dpb)(NO$_3$)$_2$(H$_2$O) (dpb=2,2'-dipyridylbenzylamine) (1) was synthesized from the reaction of Cu(NO$_3$)$_2$·3H$_2$O and dpb in ethanol solution followed by recrystallization in acetonitrile. The structure of 1 was determined by X-ray diffraction methods. The single crystal structure was characterized as follows: space group P2$_1$/c, Z=4, a=12.501(9)$\AA$, b=9.231(10)$\AA$, c=17.119(6)$\AA$, $\alpha$=90$^{\circ}$, $\beta$=107.33(4)$^{\circ}$, $\gamma$=90$^{\circ}$, V=1885.8(2)$\AA^3$, R$_1$=0.0647, $_{w}R$_2$$=0.1866 for 3258 reflections. Compound was a typical paramagnetic copper(II) complex coordinated by 2,2'-dipyridylamine derivative ligand, which was confirmed by EPR, NMR, UV/VIS, and IR spectroscopy.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.478-485
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• 2011

Merocyanine derivatives transformed from spiropyran-containing compounds by irradiating the light of ultraviolet (UV) include zwitterion of phenolate anion and amine cation. Complexation of this phenolate anion on merocyaninemodified surface and Ni ion among metal ions led to a change of surface charge and it was measured with kelvin prove force microscopy (KFM). We found that the resultant surface potential decreased linearly as UV-exposed time increased, and finally were saturated. Also it was analyzed through XPS the immobilized amount of Ni ions was increased according to increase of UV-exposed time. It is considered that these properties could be applied for detection and a quantitative control of different metal ions. Further research is to aim construct specific scaffold/matrix which enable high selective, high sensitive and, especially, a quantitative immobilization of metal ions-binding biomaterials such as proteins and cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.103-115
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• 1981

The cathodic reactions of lead anodic films formed in phosphoric acid, oxalic acid and sodium hydroxide solutions and the reactivities of Di-iso-butylnitrosoamine (DBNA) in sea water at $15\sim30^{\circ}C$ were studied by means of constant current-potential method. Besides, various contants and thermodynamic quantities obtained in the experiment were also do-scribed to explain the reactivities of protons that entered in the anodic film by being transferred across the metal-oxide interface. The electrode reactions of lead anodic film formed in sodium hydroxide solution in 60mM DBNA+0.5M NaCl did not occur because of complete insulator formed on anodic film. The values of $(\partial\triangle E_{H^+}/\partial T)_{i=const}$, estimated with Bead anodic films formed in phosphoric acid in 60mM DBNA+0.5M NaCl and 60mM $DBNA+6\%_{\circ}$ sea water were $-0.006\;V/^{\circ}C\;and\;-0.005\;V/^{\circ}C$, thus being nearly coincided, but the values of $(\partial E_o/\partial T)_{i=o}$ were $0.002\;V/^{\circ}C\;and\;-0.002\;V/^{\circ}C$, being completely inversed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.205-213
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• 2013

This study was to improve cosmetical activity of thiamine di-lauryl sulfate (TDS) by encapsulation of nanoparticle with lecithin. Results showed that most of the nanoparticles containing the TDS were well formed in round shape with below 150 ~ 200 nm diameter as well as they were fairly stable in various pH ranges by measuring zeta potentials. The nanoparticles of TDS resulted in 85% cell viability of human normal fibroblast cells (CCD-986sk) when added at the highest concentration (1.0 mg/mL). The nanoparticles of Acer mono sap showed highest free radical scavengering effect as 88.1% in adding sample (1.0 mg/mL), compared to TDS solution of non-encapsulation (81.6%). The nanoparticles of TDS reduced the expression of MMP-1 on UV-irradiated CCD-986sk cells down to as 41.4%. The TDS solution and nanoparticles showed significant anti-microbial activities agaionst the salmonella typhimurium and listeria monocytogenes at 5 and 6 days as compared with control. Anti-microbial activities of TDS nanoparticles were similar to positive control. These results indicated that TDS nanoparticles may be a source for functional cosmetic agents capable of improving cosmetical activity such as antioxidant, whitening, and anti-wrinkling effects and can be further developed as natural preservative in cosmetics.

• Journal of the Korean Chemical Society
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• v.37 no.4
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• pp.453-461
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• 1993

Detection method was developed using a simply designed photochemical reactor made of teflon coil and low pressure mercury lamp. This method of UV photolysis of analytes followed by UV, fluorescence and electrochemical detection was found to be useful for four thiocarbamates. Analytes eluting from the column are irradiated with a high flux of 254 nm UV light, so that they change to either fluorescent active forms or highly electrochemically sensitive products. Appling this technique to the UV detection, thiocarbamates were converted into long wavelength absorbing products upon UV irradiation. In fluorescence detector four thiocarbamates are not detected at nonirradiated condition but fluorescence signals of MPTC, CPTC photolysates are appeared after irradiation with UV light. The electrochemical detection for the determination of thiocarbamates was enhanced up to 5∼20 fold signal after UV irradiation, compared to that of the nonirradiated. The detection limit of thiocarbamates on electrochemical detector was 13.3∼0.02 ng under pH 7.0, ionic strength $0.5{\times}10^{-2}$ M, phosphate buffer solution. Adducts produced by reaction of photolysates and OPA-MERC in the reaction coil were monitored at 425 nm with fluorescence detector, and one of the photolysates was primary amine.