• Journal of Powder Materials
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• v.27 no.3
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• pp.233-240
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• 2020

Nano-sized ZnSe particles are successfully synthesized in an aqueous solution at room temperature using sodium borohydride (NaBH₄) and thioglycolic acid (TGA) as the reducing agent and stabilizer, respectively. The effects of the mass ratio of the reducing agent to Se, stabilizer concentration, and stirring time on the synthesis of the ZnSe nanoparticles are evaluated. The light absorption/emission properties of the synthesized nanoparticles are characterized using ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and particle size analyzer (PSA) techniques. At least one mass ratio (NaBH4/Se) of the reducing agent should be added to produce ZnSe nanoparticles finer than 10 nm and to absorb UV-vis light shorter than the ZnSe bulk absorption wavelength of 460 nm. As the ratio of the reducing agent increases, the absorption wavelengths in the UV-vis curves are blue-shifted. Stirring in the atmosphere acts as a deterrent to the reduction reaction and formation of nanoparticles, but if not stirred in the atmosphere, the result is on par with synthesis in a nitrogen atmosphere. The stabilizer, TGA, has an impact on the Zn precursor synthesis. The fabricated nanoparticles exhibit excellent photo-absorption/discharge characteristics, suggesting that ZnSe nanoparticles can be alloyed without the need for organic solutions or high-temperature environments.

• Carbon letters
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• v.24
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• pp.47-54
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• 2017

Different phytochemicals obtained from various natural plant sources are used as reduction agents for preparing gold, copper, silver and platinum nanoparticles. In this work a green method of reducing graphene oxide (rGO) by an inexpensive, effective and scalable method using olive leaf aqueous extract as the reducing agent, was used to produce rGO. Both GO and rGO were prepared and investigated by ultraviolet and visible spectroscopy, Fourier-transform infrared, scanning electron microscopy, atomic force microscopy, thermogravimetric analysis, cyclic voltammetry, X-ray photoelectron spectra, electrochemical impedance spectroscopy and powder X-ray diffraction.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.36-41
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• 1996

Drugs mean not only medicines but also poisons, pesticides, food additives, cosmetics, cleaning agents, environmental pollutants and so on, which are normally considered foreign to the body, It is important to know what happens to these drugs when they get into the body. In the past the metabolic changes of drugs had been referred to as “detoxication mechanism”, but since there are many instances in which drugs are converted in the body to more active substances. Thus, metabolism of drugs is responsible for activation and inactivation of the drugs in the body. The major reactions in drug metabolism are oxidation, reduction, hydrolysis and conjugation. Of these four areas, most of the attention had been focused on the oxidation. Therefore, in contract of ample literatures on drug-oxidizing enzymes, there were relatively few reports on drug-reducing enzymes. In recent years, however, the reduction has received an increasing interest due to its pharmacological or toxicological significance. The present lecture is organized keeping with a focus on drug-reducing enzymes which have been explored by us and by other groups.

• Journal of Integrative Natural Science
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• v.1 no.3
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• pp.192-194
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• 2008

A series of non-free hydride reducing systems containing boron or aluminum atom, which possess no metal-hydride bond but an available hydrogen at a branched ${\beta}$-position, has been applied to the selective reduction (chemo--, regio-, and stereoselective reduction) of organic compounds. The systems, comprised of diisopinocampheylborane and diisobutylalane derivatives, exhibited almost perfect selectivities in the reduction of aldehydes and ketones. The characteristics features of this systems leading to a perfect transformation have been depicted in this report, especially in the 1) Reduction of ${\alpha}$,${\beta}$-Unsaturated Carbonyl Compounds to Allylic Alcohols via 1,2-Reduction, 2) Chemoselective Reduction between Structurally Different Carbonyl Compounds, and 3) Stereoselective Reduction of Cyclic Ketones.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.321-326
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• 1997

Recently, High Range Water Reducing Admixture be used increasingly in other to improve the demanded properties (fluidity, strength, durability etc.) and workability in concrete. These kinds of agent govern quality characteristics (air content, setting time, slump, bleeding etc) by the difference of its dispersing mechanism and performance in manufacture of flowed concrete. Accordingly, in this study, for the purpose of high quality construction in site, the comparative experiment of dispersing ability due to commercially available three types of agent were carried out in paste, mortar and concrete using tow types of cement (I, V). In conclusion, the bleeding reduction by the dispersing ability of agents was verified in the fresh properties of flowed concrete with sea water resistance.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.811-815
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• 2003

The effects of high-range water-reducing agent (WRA) content and polymer-cement ratio on the strength properties of autoclaved SBR-modified mortars with WRA are examined. As a result, the flexural strength of the autoclaved SBR-modified mortars with WRAs tends to increase with increasing WRA content and polymer-cement ratio, and reaches a maximum at a WRA content of 2.0%. The compressive strength of the autoclaved SBR-modified mortars with WRAs is inclined to increase with increasing WRA content and polymer-cement ratio, and reaches a maximum at a WRA content of 2.0% and a polymer-cement ratio of 10%. From the test results, the addition of the WRAs is effective for improving strength properties of the autoclaved SBR-modified mortars.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.2
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• pp.255-266
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• 2021

Solid-state mechanochemical reduction combined with subsequent melting consolidation was suggested as a technical option for the oxide reduction in pyroprocessing. Ni ingot was produced from NiO as a starting material through this technique while Li metal was used as a reducing agent. To determine the technical feasibility of this approach for pyroprocessing, which handles spent nuclear fuels, thermodynamic calculations of the phase stabilities of various metal oxides of U and other fission elements were made when several alkaline and alkali-earth metals were used as reducing agents. This technique is expected to be beneficial, not only for oxide reduction but also for other unit processes involved in pyroprocessing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.689-696
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• 2017

The practical applications of ordinary high-fluidity concrete have been limited due to several drawbacks, such as high hydration heat, high amount of shrinkage, and non-economic strength development. On the other hand, due to its advantages, such as improvement of construction quality, reduction of construction cost and period, the development of high-fluidity concrete is a pressing need. This study examined the properties of high-fluidity concrete, which can be manufactured on the low binders using a viscosity agent to prevent the segregation of materials. The optimal viscosity agent was selected by an evaluation of the mechanical properties of high-fluidity concrete among six viscosity agents. The acrylic type and urethane type viscosity agents showed the best performance within the range where no material separation occurred. The mechanical properties were evaluated to examine the optimal amount of AC and UT viscosity agent added by mixing two viscosity agents according to the adding ratio and blending them together with high performance water reducing agent. When the ratio of the AC : UT viscosity agents was 5:5, it was most suited for high-fluidity concrete with low binders by increasing the workability and effect of the reducing viscosity.

• Biomolecules & Therapeutics
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• v.16 no.1
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• pp.54-60
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• 2008

Dyslipidemia is the multiple lipid metabolic disorders which is one of the high risk factors for the atherosclerotic diseases. It increases the morbidity and mortality and therefore, must be treated with antilipidemic agents. HMG-Co A reductase inhibitors (statins), one of many antidyslipidemic agents, have shown to be significant improvement from the various cholesterol levels. Especially, data from many comparative trials suggest that rosuvastatin is more effective than atorvastatin among many other statins. The aims of this study were to evaluate the efficacy and safety between rosuvastatin and atorvastatin in the treatment of Korean patients with dyslipidemia. Currently the Korean Society of Lipidology and Atherosclerosis based on the Korean health screening data suggests that Korean patients with dyslipidemia should be treated by the target cholesterol levels according to the Adult Treatment Panel III guidelines of the US National Cholesterol Education Program (NCEP-ATP III). We reviewed retrospectively all medical histories of the total 392 dyslipidemic patients with atorvastatin or rosuvastatin from June 1st, 2004 to August 31st, 2006 in Chungbuk National University Medical Center. Patients were classified as total 4 groups by the NCEP-ATP III Guidelines. The numbers of enrolled patients were each 5 mg atorvastatin (n=34), 10 mg atorvastatin (n=148), 5 mg rosuvastatin (n=94) and 10 mg rosuvastatin (n=82). In comparison between groups, rosuvastatin groups in the lowering LDL-C had better efficacies, and the results were each 22% (5 mg atorvastatin), 33.3% (10 mg atorvastatin), 35% (5 mg rosuvastatin) and 41.3% (10 mg rosuvastatin) with the dose relationship (P=0.000). Rosuvastatin groups also have shown to be more significantly reducing Total Cholesterol levels compared to atorvastatin groups with the no dose relationship (P=0.000). In the lowering of non-HDL cholesteroles, rosuvastatin groups showed significantly better efficacies than atorvastatin with the dose-relationship (P=0.000). Each medication groups did not demonstrate the differences in the changing of HDL cholesterol and triglyceride levels (P=0.096, 0.309, respectively). In conclusion, rosuvastatin was better efficacious than atrovastatin in reducing LDL-C Total Chol, and Tg. Therefore, rosuvastatin is a good antilipidemic agents for Korean patients with dyslipidemia and it can use to minimize the morbidity and mortality related to the cardiovascular diseases in Korean.

• Journal of Pharmaceutical Investigation
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• v.41 no.2
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• pp.59-65
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• 2011

Nanotechnology for cancer therapy is playing a pivotal role in dramatically improving current approaches to cancer detection, diagnosis, and therapy while reducing toxic side effects associated with previous cancer therapy. A widespread understanding of these new technologies will lead to develop the more refined design of optimized nanoparticles with improved selectivity, efficacy and safety in the clinical practice of oncology. This review provides an integrated overview of applications and advances of nanotechnology in cancer therapy, based on molecular diagnostics, treatment, monitoring, target drug delivery, approved nanoparticle-based chemotherapeutic agents, and current clinical trials in the development of nanomedicine and ultimately personalized medicine.