• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.175-181
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• 1998

The relation between lipid peroxidation and thrombotic reaction were investigated in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats weighing 100$\pm$10gm were randomly assigned to normal and STZ-induced diabetic group(DM). Diabetes was experimentally induced by intravenous injection of 55mg/kg of body weight of STZ in citrate buffer(pH 4.3) after 4 weeks feeding of basal diet. Animals were sacrificed at the 6th day of diabetic states. Body weight gains were lower in diabetic group after STZ injection. Serum levels of thiobarbituric acid reacting substances(TBARS) that were markedly increased in DM group compared with of normal group. TBARS levels of HDL and LDL were similar patterns to total TBARA of serum. Activities of platelet phospholipase A2(PLA2) were higher in diabetic group than those of normal group. Activities of platelet cyclooxygenase were 106% in DM group than normal group. Platelet thromboxane A2(TXA2) formation was increased in DM group than normal group. Production of aortic prostacyclin(PGI2) was lower in diabetic group than that of normal group. PGI2/TXA2 ratios were decreased by 55% in DM groups than those of normal group. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stess which leads to acceleration of lipid peroxidation and platelet aggregability. In conclusion, accelerating effect of lipid peroxidation and thrombogenesis in diabetic state is regareded to be resulted from enhancement of PLA2 activity and arachidonic acid metabolism, inhibition of antiaggrgating agent and aortic PGI2 formation.

• Journal of Adhesion and Interface
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• v.20 no.4
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• pp.140-145
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• 2019

In view of environmental considerations, the control of carbon dioxide (CO₂) and volatile organic compounds (VOCs) is one of important issues in the film and coating industries. Therefore, UV-curable system has been developed due to minimize emissions of VOCs and reduce CO₂ emission due to low energy consumption from fast curing. Also, biodegradable polymers economically are attractive because of environmental and economic concerns associated with huge waste plastics. In this study, UV-curable polyurethane acrylates with different compositions of biodegradable polylactide (PLA) diol and poly(ethylene glycol) as diols were synthesized and curing reaction of their end-capped acrylates was performed by UV exposure. Tensile strength, elongation, and Tg of the UV-cured polyurethane acrylates increased with PLA diol content in the diol while their hydrophilicity and thermal stability increased with the PEG content. These results indicated a property of UV-cured polyurethane acrylates could be controlled by environment-friendly diols.

• Journal of the Korean Chemical Society
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• v.19 no.3
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• pp.198-206
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• 1975

Polymers with photosensitive functional groups, the naphthoquinone-1,2-diazide-5-sulfonyl esters(PGND, BEND and PVAND) of polyglyceryl phthalate(PG), bisphenol A-epichlorohydrin polycondensate(BE) and polyvinyl alcohol(PVA), were prepared. The molecular weights of the starting materials were determined by the cryoscopic method, i.e., in the range of 650${\sim}$1200 for PG and 780${\sim}$1320 for BE, PGND, BEND and PVAND were prepared by esterification of PG, BE and PVA with naphthoquinone-1,2-diazidie-5-sulfonyl chloride, and the replacements of such a functional groups were confirmed by the infrared absorption spectra and elemental analyses. The good agreement between the observed values of elemental analyses (PGND, BEND and PVAND) and the calculated values, indicated that the degree of polymerization did not change in the course of esterification of PG, BE and PVA.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.53-59
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• 2006

.FAPO-5 molecular sieves were synthesized starting from the same reactant gel at 170 oC using microwave irradiation technique and conventional hydrothermal reaction. The FAPO-5 molecular sieves were characterized by several techniques such as SEM, FTIR, UV/Vis, and ESR. Moreover, the oxidation of styrene over FAPO-5s was carried out, and compared to check the oxidation and epoxidation ability of the two FAPO-5s. FAPO-5 can be obtained easily by microwave irradiation within 15 min at 170oC, whereas FAPO-5 synthesis is completed in 6 h by conventional electric heating, confirming the acceleration about 20 times by microwave technique. There are no appreciable differences between two FAPO-5s in surface area and coordination state of iron. The FAPO-5 synthesized by microwave irradiation shows higher epoxide selectivity in the styrene epoxidation, which may be explained by the higher hydrophobicity of the catalyst.

• Journal of the Korean Chemical Society
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• v.40 no.5
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• pp.365-373
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• 1996

A series of new dimesogenic compounds, di-4-(p-substituted phenoxycarbonyl) phenoxyethyltetramethyldisiloxanes, were prepared and identified. Another compound having a $\beta$-naphthyl group in the place of a p-substituted phenyl ring was also synthesized. The results were as follows, 1) The compounds were synthesized with considerably high yields in the range of 85% to 95%. 2) All of the compounds are enantiotropic and form smectic phase in melt, the compound with $X=NO_2$ is $S_A$ while the remaining ones are SB. 3) Liguid crystalline phase transion of the compounds were influenced in corporations of the size and electron affinity of the substituent. 4) The heats of melting ΔHm, are particulary low, while the heats of isotropization, ΔHi, are comparable to other dimesogenic compounds. 5) The smectic group efficiency of the substituents in the compounds is in the order of $H

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.154-161
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• 1993

Four kinds of new phosphinate derivatives with a pendant monoazacrown ether were synthesized and their biological activities were tested. These biologically active phosphinates were synthesized in relatively good yields (61∼72%) by one step reactions of phenylphosphinate with aldehyde and monoazacrown ether. Toxicity of these compounds was tested by intraperitoneal injection of the compounds to male mouse and revealed $LD_{50}$ value of 65∼90 mg/kg, which showed enhanced toxicity by attachment of a pendant azacrown ether to a simple phenylphosphinate structure. Although the ring size effect of the pendant crown ethers, (monoaza-15-crown-5 and monoazo-18-crown-6), beening negligible, the identity of the ester functional group in the phosphinate structure exerted sizable influence on toxicity. Thus, phosphinate derivative with octyl or propyl ester group showed somewhat higher toxicity than that with ethyl ester group.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1135-1138
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• 2009

Hollow Sn and Pb nanoparticles have been prepared by a rapid injection of an aqueous solution of $SnCl_2$- poly(vinylpyrrolidone) (PVP, surfactant) and $Pb(OAc)_2${\cdot}$3H_2O-PVP$ into an aqueous solution of sodium borohydride (reducing agent) in simple, one-pot reaction at room temperature under an argon atmosphere, respectively. The two hollow nanoparticles have been fully characterized by TEM, HRTEM, SAED, XRD, and EDX analyses. Upon exposure to air, the black Pb hollow nanoparticles are gradually transformed into a mixture of Pb, litharge (tetragonal PbO), massicot (orthorhombic PbO), and $Pb_5O_8$. The order and speed of mixing of the reactants between the metal precursor-PVP and the reductant solutions and stoichiometry of all the reactants are crucial factors for the formation of the two hollow nanocrystals. The Sn and Pb hollow nanoparticles were produced only when 1:(1.5-2) and 1:3 ratios of the Sn and Pb precursors to $NaBH_4$ were employed with a rapid injection, respectively.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2867-2872
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• 2010

Two new energetic organic alkali metal salts, 1,1-diamino-2,2-dinitroethylene rubidium salt [Rb(FOX-7)${\cdot}H_2O$] and 1,1-diamino-2,2-dinitroethylene cesium salt [Cs(FOX-7)${\cdot}H_2O$], were synthesized by reacting of 1,1-diamino-2,2-dinitroethylene (FOX-7) and rubidium chloride or cesium chloride in alkali methanol aqueous solution, respectively. The thermal behaviors of Rb(FOX-7)${\cdot}H_2O$ and Cs(FOX-7)${\cdot}H_2O$ were studied with DSC and TG methods. The critical temperatures of thermal explosion of the two compounds are 216.22 and $223.73^{\circ}C$, respectively. Specific heat capacities of the two compounds were determined with a micro-DSC method, and the molar heat capacities are 217.46 and $199.47\;J\;mol^{-1}\;K^{-1}$ at 298.15 K, respectively. The adiabatic times-to-explosion were also calculated to be a certain value of 5.81 - 6.36 s for Rb(FOX-7)${\cdot}H_2O$, and 9.92 - 10.54 s for Cs(FOX-7)${\cdot}H_2O$. After FOX-7 becoming alkali metal salts, thermal decomposition temperatures of the compounds heighten with the rise of element period, but thermal decomposition processes become intense.

• Korean Journal of Crystallography
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• v.8 no.2
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• pp.97-104
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• 1997

Hydrothermal synthesis of PbZ1-xTixO3 has been investigated. Syntheses were performed using lead acetate triphdrate as Pb source, Ti/Zr gel by hydrolizing Ti-isopropoxide as Tiand Zr source and Zr-propoxide and KOH (0.5m, 1m, 2m) as mineralizer. The hydrothermal synthesis has been examined at 140℃, 150℃ and 160℃. Synthesized PZT powders showed a rectangular shape and were agglomerate. At 1m and 2m KOH concentrations PZT powders were synthesized the respective time of 8 hrs and 1hr but at 0.5m KOH concentration phase pure PZT powders were not synthesized for 5days reaction. At the conditions of low temperature and low KOH concentration unreacted Ti/Zr gel remained although synthesized powders were almost PZT. The size of PZT powders increased with KOH concentrations. PbO solid solutions were formed as intermediate phases and these were classified to PbO-10%TiO2 solid solution and PbO-3% TiO-3% TiO2 solid solution.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.894-898
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• 2016

Solution plasma is a unique method which provides a direct discharge in solutions. It is one of the promising techniques for various applications including the synthesis of metallic/non-metallic nanomaterials, decomposition of organic compounds, and the removal of microorganism. In the context of nanomaterial syntheses, solution plasma has been utilized to produce carbon nanoparticles and metallic-carbon nanoparticle systems. The main purpose of this study was to synthesize nickel nanoparticles embedded in a matrix of carbon particles by solution plasma in one-step using waste vegetable oil as the carbon source. The experimental setup was done by simply connecting a bipolar pulsed power generator to nickel electrodes, which were submerged in the waste vegetable oil. Black powders of the nickel nanoparticles-embedded carbon (NiNPs/Carbon) particles were successfully obtained after discharging for 90 min. The morphology of the synthesized NiNPs/Carbon was investigated by a scanning electron microscope, which revealed a good dispersion of NiNPs in the carbon-particle matrix. The X-ray diffraction of NiNPs/Carbon clearly showed the co-existence of crystalline Ni nanostructures and amorphous carbon. The crystallite size of NiNPs (through the Ni (111) diffraction plane), as calculated by the Scherrer equation was found to be 64 nm. In addition, the catalytic activity of NiNPs/Carbon was evaluated by cyclic voltammetry in an acid solution. It was found that NiNPs/Carbon did not show a significant catalytic activity in the acid solution. Although this work might not be helpful in enhancing the activity of the fuel cell catalysts, it is expected to find application in other processes such as the CO conversion (by oxidation) and cyclization of organic compounds.