• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.328-335
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• 1996

Effects of hydrogen peroxide$(H_2O_2)$ on polyphenol oxidase (PPO) in Perillae Folium were investigated. The inactivation of this enzyme was dependent on $H_2O_2$ concentration. and the initial lag period was not shown. Preincubation of Perillae Folium PPO with $H_2O_2$ in the absence of a substrate resulted in rapid loss of enzymatic activity. The inactivation of PPO by $H_2O_2$ dependents temperature and pH. OH radical scavengers such as mannitol and sodium formate did not protect the enzyme against inactivation by $H_2O_2$. Substrate analogue such as phenylalanine protected the enzyme against inactivation by $H_2O_2$. and copper chelator such as sodium azide also protected the enzyme.

• Journal of The Korean Society of Clinical Toxicology
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• v.4 no.2
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• pp.166-169
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• 2006

Poisonings caused by 'mad honey' are known to occur in response to grayanotoxins, which bind to sodium channels in the cell membrane, increasing membrane sodium permeability and preventing inactivation. Mild symptoms of mad honey intoxication are dizziness, weakness, hypersalivation, nausea, vomiting, and paresthesia. Severe intoxication, however, leads to serious cardiac manifestations such as atrioventricular block, dose-dependent hypotension, bradycardia, and respiratory depression. Atropine and vasoactive drugs improve symptoms of both bradycardia and respiratory rate depression. We report an unusual case of saliva-type hyperamylasemia in a mad honey poisoning patient who developed clinically significant bradycardia. She recovered fully within 3 days following atropine administration and medical treatment.

• Applied Biological Chemistry
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• v.27 no.1
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• pp.52-54
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• 1984

Ethanol fermentation from the chemically gelatinized starchy material was examined. The critical concentration of sodium hydroxide solution for gelatinization was dependent on the species of starch; 0.4M for potato and 0.6M for tapioca at room temperature. For alcohol fermention the starchy material was gelatinized by addition of sodium hydroxide solution, neutralized by sulfuric acid, and then yeast was added. The amount of $CO_2$ evolved during ethanol fermentation indicates that non-fermentable material was not produced from the starch by chemical gelatinization. In ethanol fermentation of potato and tapioca starch no significant difference was observed between the thermal and the chemical gelatinization.

• Korean Journal of Microbiology
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• v.28 no.4
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• pp.297-303
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• 1990

Secretion of Serratia marcescens nuclease by E. coli harboring pNUC4 was investigated. 29.2, 54.2 and 16.6% of total nuclease were observed in culture medium, periplasm, and cytoplasm of E. coli, respectively. To investigate the secretion mechanism of Serratia nuclease by E. coli, secretion kinetics of nuclease was examined in the presences of sodium azide, and energy metabolism inhibitor; procaine, an exoprotein processing inhibitor; and chloramphenicol, a protein synthesis inhibitor. In the presence of sodium azide, periplasmic unclease was gradually decreased and the extracellular nyclease was linearly increased according to the incubation time. Similar results were obtained in presences of procaine and chloramphenicol. From these results, we concluded that two transport processes are involved in nuclease secretion: secretion of nuclease through the inner membrane is occurred by an energy-dependent process and probably requiring precusor processing: secretion of nuclease through outer membrane does not require energy, de novo protein synthesis, and precursor processing.

• Journal of Pharmaceutical Investigation
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• v.18 no.1
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• pp.31-41
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• 1988

Computer optimization technique was applied to obtain the optimum formula of o/w type ointment vehicle containing sodium lauryl sulfate and 1-methyl-2-pyrrolidinone (MP). In order to determine the feasibility of optimizing a vehicle composition with the aid of computer, the amounts of sodium lauryl sulfate $(X_1)$, salicylic acid $(X_2)$, and MP $(X_3)$ were selected as the independent variables for the solubility and the absorption rates of salicylic acid (dependent variables). The experimental values of absorption rates agreed well with the calculation values obtained from the polynomial regression analysis, and the contour charts drawn by computer were useful in optimization process.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.5
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• pp.275-278
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• 2003

Antioxidative activity is an important factor in inhibiting oxidative stress. The usual methods for determining antioxidative activity are time-consuming and cumbersome. They are also indirect processes that use biological material such as brain or liver microsome. This study therefore proposed a new method. Redoxpotential was determined using galvanic cell with or without the addition of various antioxidants or herbal extracts in zinc sulfate solution. The result was compared with the results from the TBA method and the peroxide value from sodium thiosulfate titration. All methods showed significant and dose-dependent enhancement of antioxidative activity by adding ascorbic acid, quercetin, ginseng, or gingko biloba extract. The result of redox potential using galvanic cell showed the smallest standard deviation and took the shortest time among the three methods. Therefore, the antioxidative potential of chemical substances and herbal extracts can be determined simply, directly and accurately in a short period of time using galvanic cell.

• Journal of Pharmaceutical Investigation
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• v.23 no.4
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• pp.213-216
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• 1993

${\kappa}-Carrageenan$, an anionic polysaccharide, was employed in tablet formulations and its function as a drug release sustaining agent was investigated. Tablets composed of ${\kappa}-carrageenan$ and hydroxypropyl methylcellulose were fabricated by using direct compression method. Lactose and sodium alginate were utilized as controls for ${\kappa}-carrageenan$. Drug release experiments performed at pHs 1.2 and 7.4 revealed that ${\kappa}-carrageenan$ retains pH-dependent sustained release effects due to its anionic characteristics. Also, the ionic interaction between ${\kappa}-carrageenan$ and drugs exerted significant affects on drug release kinetics. ${\kappa}-Carrageenan$ was found out to be a useful additive for sustained release tablet formulations.

• Bulletin of the Korean Chemical Society
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• v.8 no.2
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• pp.79-83
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• 1987

The reduction of a series of 1-substituted benzyl-3-cyanoquinolinium ions (p-$cH_3$, H, p-Br, m-F, p-CN) by sodium borohydride has been investigated. In all cases the products from these reactions were found to be 1, 2-dihydroquinolines over 82% yields. Rates of reduction were measured in basic condition and in solvent system consisting of 4 parts of isopropyl alcohol and 1 part of water by volume. Second order rate constants were obtained for these reactions. When the ratio of [$OH^-$] to [$BH_4^-$] becomes large the observed rate constants ($K_{obs}$) decrease by a small factor. Reaction scheme and rate law are discussed. Bronsted ${\alpha}(=\frac{d\;In\;k}{d\;In\;K})$ obtained by using the value of equilibrium constant K, which was obtained previously, was not 0. Instead, a value of 0.36 was obtained which indicated that the reduction by borohydride was structure-dependent according to the Marcus formalism even though the reaction rate was close to the diffusion limit.

• International Journal of Industrial Entomology and Biomaterials
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• v.47 no.2
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• pp.73-78
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• 2023

Currently, Hyphantira cunea Drury, the fall webworms (FWW), is one of the most severe insect pest for various landscaping trees and mulberry trees. In this study, we investigated whether FWW might be managed by Sodium saccharin (SAC) which is a food additive and not toxic to humans and environment. We found that FWW larvae treated with various concentrations of SAC showed dose-dependent delayed development and low survival rates. The lethal-concentration 50% of FWW larvae to SAC was 0.03 M. We also confirmed that SAC can be used to control FWW larvae attacking mulberry trees in the field. Compared to not-treated or tap-water-spraying control groups, SAC-spraying groups showed significantly higher mortality rates of FWW larvae (56.2%). Thus, SAC can be used for control FWW larvae in mulberry trees.

• Structural Engineering and Mechanics
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• v.89 no.4
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• pp.335-347
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• 2024

This study pioneers the exploration of creep and shrinkage behavior in ambient-cured geopolymer concrete (GPC), a vital yet under-researched area in concrete technology. Focusing on the influence of sodium hydroxide (NaOH) solution concentration, the research utilizes low calcium fly ash (Class-F) and alkaline solutions to prepare two sets of GPC. The results show distinct patterns in compressive strength development and dry shrinkage reduction, with a 14 M NaOH solution demonstrating a 26.5% lower dry shrinkage than the 16 M solution. The creep behavior indicated a high initial strain within the first 7 days, significantly influenced by curing conditions and NaOH concentration. This study contributes to the existing knowledge by providing a deeper understanding of the time-dependent properties of GPC, which is crucial for optimizing its performance in structural applications.