• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.125-132
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• 2009

In order to develop probiotics which may be a viable alternative of antibiotic use in pig industry, five bacterial strains (Lactobacillus sp. HN 52, 92, 98, 235 and AP 116) possessing antimicrobial properties were selected from 500 strains isolates of pig intestines. The bacteriocin produced by Lactobacillus sp. HN 235 displayed a relative broad spectrum of inhibitory activity against all Enterococcus strains, Pseudomonas aeruginosa, Listeria monocytogenes and Clostridium perfringens using the spot-on-lawn method. The production of antimicrobial substance started in the middle of the exponential growth phase, reached maximum levels (6,400 AU/mL) in the stationary phase, and then declined. Bacteriocin activity remained unchanged after 30 min of heat treatment at $95^{\circ}C$ and stable from pH 2.0 to 10 for 1 h, or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.571-578
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• 2016

Recently, review on viability of various industrial by product and natural materials as raw material for concrete has been actively done in aspect of environment-friendly issue and depletion of natural resource. This study conducted fundamental study on the possibility of utilizing mud flat as admixture and filling material for concrete. First, chemical analysis on the viability of mud flat as admixture was done and the researchers compared it with the substance of fly ash and blast furnace slag. According to the result, substance content was proven to be inadequate. In addition, as the replacement rate of mud flat increased, compressive strength and tensile strength decreased. According to the estimated result of chemical substance analysis, possibility of utilizing mud flat as admixture was low. According to the result of experiment done as filling material, 10% ~ 30% replacement rate of mud flat manifested more than 8 Mpa of compressive strength of block which may be utilized for secondary product. However, additional experiment such as making block is required afterward. According to the result of flow experiment, as the replacement rate of mud flat increased, flow value decreased, and through chloride content analysis test, it was proven that mud flat is inappropriate to be applied as steel beam using structure since it has high content of sodium. It may be utilized as products that does not use steel beam such as internal brick.

• The Korean Journal of Physiology
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• v.11 no.1
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• pp.27-32
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• 1977

Diospyros Kaki Thunberg is the species of persimmon tree that grows in Korea. Although its fresh or dried fruits are often served as a desert, it has little been known if persimmon tree has any specific pharmacological action. The leaves and branches of persimmon tree has long been used as folk remedies for palsy and frostbite in the southern part of Korea and it is also in use for the treatment of hiccup and nocturnal enuresis in chinese herbal medicine. Recently it was reported that an intravenous administration of Diospyros Kaki Thunberg ethanol extract (KTEE) into the animals lowered arterial blood pressure. Lee concluded from his study on the mechanism of depressor action of KTEE that at least a part of depressor response he observed was caused by acetylcholine-like action of KTEE. On the other hand little study has been made on the effect of KTEE on the motility of isolated animal intestines. Therefore the present study was undertaken to investigate effect of KTEE and the mechanism of its action on the motility of isolated rabbit duodenum. Ethanol extract of Diospyros Kaki Thunberg was prepared by boiling 1 kg of dried branches of persimmon tree in 1 liter of ethanol and the motility of isolated rabbit duodenum was recorded on physiograph by means of force transducer connected with Magnus apparatus. Doses of KTEE used were $5{\times}10^{-4}gm/ml,\;1{\times}10^{-3}gm/ml,\;and\;2{\times}10^{-3}gm/ml$. And the isolated duodenum was separately pretreated with acetylcholine $(5{\times}10^{-7}gm/ml)$, pilocarpine $(2.5{\times}10^{-6}gm/ml)$, histamine $(5{\times}10^{-6}gm/ml)$ and barium chloride $(2.5{\times}10^{-5}gm/ml)$ in order to find out interactions of these drugs with KTEE. The results obtained are as follows: 1. At doses of $5{\times}10^{-4}gm/ml,\;1{\times}10^{-3}gm/ml$ KTEE reduced contractions of isolated duodenum, while tonus as well as contaction of duodenum were depressed with $2{\times}10^{-3}gm/ml$ of KTEE. 2. Since the inhibitory effect of KTEE on the intestinal motility was not blocked by pretreatment with acetylcholine, pilocarpine, and barium chloride, it was strongly suggested that the inhibitory action of KTEE on intestinal motility is mainly Caused by its antihistamine effect. 3. It is also concluded that the principal substance of KTEE responsible for inhibition of intestinal motility may also have a vasodilating activity and would not be an acetylcholine-like substance in case it is same substance as that cause depressor responses.

• Journal of the Korean Society of Safety
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• v.38 no.5
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• pp.8-14
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• 2023

Lithium ions can induce the thermal runaway phenomenon and lead to reignition due to electrical, mechanical, and environmental factors such as high temperature, smoke generation, explosions, or flames, which is extremely likely to create safety concerns. Therefore, one of the ways to improve the flame retardancy of the electrolyte is to use a flame-retardant additive. Comparing the associated characteristic value of existing substances with the required experimental value, it was found that these values were either considerably different or were not documented. It is vital to know a substance's combustion characteristic values, flash point, explosion limit, and autoignition temperature (AIT) as well as its combustion characteristics before using it. In this research, the flash point and AIT of materials were measured by mixing a highly volatile and flammable substance, diethyl carbonate (DEC), with flame-retardant dimethyl methylphosphonate (DMMP). The flash point of DEC, which is a pure substance, was 29℃, and that for DMMP was 65℃. Further, the lower explosion limit calculated using the measured flash point of DEC was 1.79 Vol.%, while that for DMMP was 0.79 Vol.%. The AIT was 410℃ and 390℃ for DEC and DMMP, respectively. In particular, since the AIT of DMMP has not been discussed in any previous study, it is necessary to ensure safety through experimental values. In this study, the experimental and regression analysis revealed that the average absolute deviation (ADD) for the flash point of the DEC+DMMP DEC+DMMP system is 0.58 sec and that the flash point tends to increase according to changes in the composition employed. It also revealed that the AAD for the AIT of the mixture was 3.17 sec and that the AIT tended to decrease and then increase based on changes in the composition.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.28 no.1
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• pp.4-13
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• 2017

The seeds of addiction are typically sown years prior to the onset of addictive substance use or engagement in addictive behaviors, due to the priming of the reward pathway (RewP) by alterations in the mechanism of stress-signaling from the hypothalamic-pituitary-adrenal axis (HPA) and related pathways. Excessive stress from a single-event and/or cumulative life experiences during childhood, such as those documented in the Adverse Childhood Experiences Study, is translated into neurobiological toxicity that alters the set-point of the HPA axis and limbic system homeostasis [suggested new term: regulation pathway (RegP)]. The resultant alteration of the RegP not only increases the risk for psychiatric and physical illness, but also that for early onset and chronic addictions by dysregulating the RewP. This paper reviews the interface of these symbiotic pathways that result in the phenotypic pathology of emotional dysregulation, cognitive impairment, and compulsive behaviors, as well as morbidity and shorter life expectancy when dysregulated by chronic stress.

• Journal of Environmental Health Sciences
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• v.15 no.2
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• pp.33-40
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• 1989

Dichromate reflux method for COD analysis is one of the useful and precise way to solve the organic content of the wastewater. But the standard procedure for COD is not entirely satisfactory for sample containing appreciable amounts of inhibiting substance, especially chloride ion. Under the conditions of the established test, a big disadvantage of the method is that dichromate oxidizes chloride quantitatively to chlorine. When it is necessary to use silver sulfate as a catalyst in the COD procedure, chloride must be removed before the addition of the catalyst. Silver sulfate and mecuric sulfate forms a precipitate of AgCl and HgCl$_{2}$ separately which is not completely oxidized during the test and, therefore, cannot be corrected for. So, we evaluate and compensate the amount of chloride oxidation in the absence of chemicals during the experimental procedure. Calculation of COD is made using the following reviced formula: real COD = tested COD - 0.2277Cl.

• Communications for Statistical Applications and Methods
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• v.27 no.1
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• pp.15-35
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• 2020

In research on behavioral studies, significant attention has been paid to the stage-sequential process for multiple latent class variables. We now explore the stage-sequential process of multiple latent class variables using the multivariate latent class profile analysis (MLCPA). A latent profile variable, representing the stage-sequential process in MLCPA, is formed by a set of repeatedly measured categorical response variables. This paper proposes the extended MLCPA in order to explain an association between the latent profile variable and the latent group variable as a form of a two-dimensional contingency table. We applied the extended MLCPA to the National Longitudinal Survey on Youth 1997 (NLSY97) data to investigate the association between of developmental progression of depression and substance use behaviors among adolescents who experienced Authoritarian parental styles in their youth.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.S1
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• pp.77-85
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• 1996

As conservation of global environment has becoming a major outstanding issue of the world, the International Maritime Organization(IMO) has been legislation a convention for prevention of air pollution from ships. By the new convention, use of air pollutants such SOx, NOx, Freon and Halin Gas shall be restricted. In this regards, analysing these requirements of the convention is required as the cinvention will also be applied in restriction of descharging exhaust gases from ships by estsblishing a requirement of Sox and NOx discharged. The purpose of this study is as follows; 1) Introdcuing of the backgrounds of legislating the convention for prevention of air pollution from ships and major contents of the convention and a countermeasuures in the convention by Korea 2) Reviewing by analyzing the influence in domestic industries concernd by restriction of SOx, NOx in exhaust gases and sulpher content of fuel oil 3) Preparing a countermeasure in the convention properly.

• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.145-150
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• 1987

Urine NMR analyses made by use of an 80 MHz proton NMR spectrometer show that aromatic proton NMR signals appear in most censer patients'urine. On the assumption that the signals may be caused by the phenolic compound of tyrosine excreted in the urine, a jellied reagent is used for identifying them by observing the urine color reaction. It is observed that the reagent reacted to the cancer urine becomes red. Such a change of the urine color seems to indicate the substance of tyrosine. Recently an attempt to determine the reagent sensitivity an specificity of the urine of 69 persons including cancer and noncancer patients has been made. The results of the attempt are respectively 85.3% for sensitivity and 91.4% for specificity. This seems to show a possibility that the reagent can be used for the diagnosis.

• Transactions on Electrical and Electronic Materials
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• v.17 no.2
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• pp.69-78
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• 2016

Liquid crystals are important materials because of their applications in display technology and many other scientific applications. Different mixtures of liquid crystals and their doped samples have gained interest because a single liquid crystal compound cannot fulfill all the required parameters for the display application. The doping can be accomplished with dyes, polymers, or composite nanoparticles among other substance. The addition of nanoparticles can modify the physical properties of the host liquid crystal and enhances the performance of electro-optical devices. The present study is focused on investigations of possible changes in dielectric and electro optical properties of liquid crystals caused by doping with ceramic nanoparticles. Including smaller nanoparticles were found to be better candidates for use in suppressing the unwanted ion effects in liquid crystal displays.