• KSBB Journal
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• v.24 no.5
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• pp.446-452
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• 2009

Oleyl alcohol, butyl butyrate, and two different ionic liquids were evaluated for the extraction of butanol from culture broth without toxic effect to cells. The tested solvents showed more than 50% extraction efficiency, and oleyl alcohol was chosen as the best extractant for butanol among the used extractants with a partition coefficient of 2.89. When oleyl alcohol was used as an extractant, more than 80% of butanol was extracted in the wide range of butanol concentrations (1-20 g/L) and pH values (pH 4-5.5). In extractive fermentation using oleyl alcohol only, there was 11% more butanol production and glucose consumption when compared to that without extractive fermentation, implicating a reduced inhibitory effect of butanol due to butanol removal to the oleyl alcohol phase. In addition, oleyl alcohol did not inhibit cell growth, while a mixture of oleyl alcohol and butyl butyrate with the volume ratio of 9:1~7:3 inhibited either butanol production or cell growth significantly due to the toxicity of butyl butyrate to cells. In conclusion, oleyl alcohol can be used as an efficient and non-toxic solvent for extractive fermentation for butanol production.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.187-193
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• 2012

Acute toxicity, water resolvability and short term reproduction test on Japanese medaka (Oriyzias latipes) for evaluating alachlor susceptibility to endocrine system were studied. Alachlor is known for suspected endocrine distruptors. As the results of tests, $LC_{50}$ (Median lethal concentration) was determined as 2.36 (1.994~2.805) mg/L, and test water replaced at 7 day intervals as its water resolvability was less than 20% in 7 days. The short term reproduction tests on Japanese medaka (Oriyzias latipes) were performed with a solvent control group, a treated group (alachlor concentrations of 0.02, 0.04, 0.11, 0.27, 0.68 ppm) and a positive control group (17 ${\beta}$ estradiol, 0.01, 0.1, 0.5 ppb). The number of spawning and embryo rates were declined in a alachlor-dose dependent manner, and the number of unfertilized eggs rates were in contrast increased depending on the concentrations. Further study should be needed to confirm whether the adverse effects may be effected by the concentrations. Additionally, alachlor was evaluated as a non-vitellogenin by the result of a test of significance of the vitellogenin content test for determination of the effect of estrogen among the endocrine disruptors.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.123-131
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• 2018

The objective of this study was to evaluate the effect of roasting degree of barley on aroma characteristics of boricha (barley tea) using solvent-assisted flavor evaporation-gas chromatography-mass spectrometry and gas chromatography-olfactometry. Fifteen volatile compounds including pyrazine, ethylpyrazine, butyrolactone, and guaiacol were considered important volatile compounds, which are generated by roasting barley, because concentrations of those volatiles were significantly increased (p<0.05) as roasting degree of barley was darker. Guaiacol (smoky), furfuryl alcohol (burnt sugar), and furfural (caramel) were detected as aroma-active compounds of boricha with high intensity. Aroma intensity of aroma-active compounds in boricha increased with increase in roasting degree of barley. However, one unknown compound with burnt smell was detected as off-flavor in dark roasted barley. Therefore, it is implied that medium roasting of barley is desirable during boricha manufacturing. Furthermore, boricha manufactured with steamed barley contained more abundant volatile flavor compounds, which may lead to better aroma quality of boricha.

• Journal of Life Science
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• v.19 no.12
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• pp.1841-1846
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• 2009

Menopause is often associated with the incidence of several chronic diseases including osteoporosis, cardiovascular disease, and obesity. Hormone replacement therapy (HRT) is an effective regimen that has been found to prevent these diseases in postmenopausal women. However, HRT is accompanied by an increased risk of unfavorable outcomes. Therefore, this study was conducted to evaluate the effects of Ecklonia cava, a kind of seaweed, extract on bone turnover markers in symptomatic menopausal women. For this study, the following four groups of 9-week-old Sprague-Dawley rats were evaluated over 6 weeks: normal rats (SHAM), ovariectomized rats (OVX-CON) and ovariectomized rats that were treated with Ecklonia cava extracts. The optimum extraction temperature and solvent of Ecklonia cava were found to be $80^{\circ}C$ and 80% ethanol. We measured the osteocalcin and CTx content, enzyme ALP activity in serum and collagen content in the cartilage, bone, skin and lungs. We found that the levels of indicators of bone metabolism such as ALP, osteocalcin and CTx were lower in rats in the Ecklonia cava extract group than the OVX-CON group. In addition, the collagen contents in the bone, cartilage, skin and lungs decreased in response to ovariectomy, but the levels of collagen were greater in the bone of rats that were treated with Ecklonia cava extract than in the bone of rats in the OVX-CON group. According to these results, we were able to know the effects of Ecklonia cava extract on bone aging in ovariectomized rats. Consequently, we expect Ecklonia cava extract to have an effect on bone aging in postmenopausal women.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.1026-1031
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• 2004

Acetylcholinesterase inhibitory activity and protective effect against cytotoxicity of PC 12 cell induced by beta-amyloid protein and glutamate were examined in perilla seed methanol extract and its solvent fractions. Methanol extract of perilla seed showed dose-dependent acetylcholinesterase inhibitory activity, with n-butanol fraction showing strongest activity. Perilla seed methanol extract also decreased glutamate- and ${\beta}-amyloid$ protein $(A{\beta})-induced$ cytotoxicities of PC 12 cells dose-dependently. Formation of TBARS induced by $FeSO_{4^-}H_2O_2$ in rat brain was significantly reduced by perilla seed methanol extract, with strongest protective activity formation of TBARS shown in n-butanol fraction. Results suggest perilla seed methanol extract may attenuate actylcholinesterase activity and cytotoxicity induced by glutamate and ${\beta}-amyloid$ protein through suppression of oxidative stress.

• The Korean Journal of Food And Nutrition
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• v.33 no.2
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• pp.215-221
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• 2020

The purpose of this study was to investigate the protective effect on oxidative stress induced PC12 cells, and volatile flavor composition of essential oils derived from medicinal plant seeds- Gossypium hirsutum L. (G. hirsutum), Coix lachryma-jobi (C. lachryma-jobi) and Oenothera biennis (O. biennis). The essential oils were obtained by the solvent (hexane) extraction method from the seeds. The essential oils of the seeds were analyzed by the solid-phase micro-extraction gas chromatography mass spectrometry (SPME-GC/MS). The major compounds of G. hirsutum, C. lachryma-jobi and O. biennis were cyclonexanol (16.65%), β-asarone (14.29%) and ylangene (50.01%). The DPPH radical scavenging activity (IC₅₀) was the highest value of 8.52 mg/mL in the O. biennis. Additionally, IC₅₀ values of G. hirsutum and C. lachryma-jobi were 26.76 mg/mL and 36.81 mg/mL. For the oxidative stress on PC12 cells, we treated with hydrogen peroxide (H₂O₂). The pretreatment of oxidative stress induced PC12 cells with all the essential oils preserved or increased their cell viability and G. hirsutum and O. biennis attenuated the ROS generation (by 68.75% and 56.25% vs. H₂O₂ control). The results of this study suggest that the essential oils derived from medicinal plant seeds could be used as valuable back data as a natural essential oil material to prevent neurodegenerative diseases by protecting neuro-cells.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.1
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• pp.64-74
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• 2016

Objectives: The purpose of this study was to investigate whether chemical exposure among workers has relevance to dyspnea using data from the $3^{rd}$ Korea Working Conditions Survey. Methods: The research subjects were 29,711 wage workers. Chemical exposures consist of four factors, (1) breathing in vapors, fumes, dust and dirt, (2) breathing in organic solvent vapors, (3) handling or touching chemicals, and (4) secondhand smoke. Multiple logistic regression analysis was performed to examine the association between chemical exposure and dyspnea in the last 12months using proc surveylogistic in SAS 9.3 statistical software excluding people who had received a diagnosis of hypertension or obesity that can affect the respiratory distress symptoms(n=27,842). Results: Chemical exposure among workers was associated with dyspnea after adjustment for demographics and job characteristics. Prevalence of dyspnea was 4.9 per 1,000 among men and 5.8 per 1,000. Compared to a total score of 0 points of chemical exposure among workers, a total score of 1, 2-3, and 4 points tended to have increased risk of dyspnea in a dose-response manner for both men (OR=1.43, 1.93, and 4.26; P-for trend=0.002) and women(OR=1.10, 2.81, and 7.70; P-for trend=0.002). Stratified analysis by duration of current job showed that the association between chemical exposure and dyspnea tended to get stronger until 15 years and then disappeared afterwards, which reflects healthy worker survivor effect. Conclusions: We observed significant association between chemical exposure and dyspnea using the data of the $3^{rd}$ Korea Working Conditions Survey. Our results warrants providing knowledge related to chemical exposure, performing prevention activities, and creating various health policies to protect workers.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.04a
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• pp.5-5
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• 1999

The Principal deficiency of the existing notion about the sintering-mixtures consists in the fact that almost no attention is focused on the Phenomenon of alloy formation during sintering, its connection with dimensional changes of powder bodies, and no correct ideas on the driving force for the sintering process in the stage of establishing chemical equilibrium in a system are available as well. Another disadvantage of the classical sintering theory is an erroneous conception on the dissolution mechanism of solid in liquid. The two-particle model widely used in the literature to describe the sintering phenomenon in solid state disregards the nature of the neighbouring surrounding particles, the presence of pores between them, and the rise of so called arch effect. In this presentation, new basic scientific principles of the driving forces for the sintering process of a two-component powder body, of a diffusion mechanism of the interaction between solid and liquid phases, of stresses and deformation arising in the diffusion zone have been developed. The major driving force for sintering the mixture from components capable of forming solid solutions and intermetallic compounds is attributed to the alloy formation rather than the reduction of the free surface area until the chemical equilibrium is achieved in a system. The lecture considers a multiparticle model of the mixed powder-body and the nature of its volume changes during solid-state and liquid-phase sintering. It explains the discovered S-and V-type concentration dependencies of the change in the compact volume during solid-state sintering. It is supposed in the literature that the dissolution of solid in liquid is realised due to the removal of atoms from the surface of the solid phase into the melt and then their diffusicn transfer from the solid-liquid interface into the bulk of liquid. It has been shown in our experimental studies that the mechanism of the interaction between two components, one of them being liquid, consist in diffusion of the solvent atoms from the liquid into the solid phase until the concentration of solid solutions or an intermetallic compound in the surface layer enables them to pass into the liquid by means of melting. The lecture discusses peculimities of liquid phase formation in systems with intermediate compounds and the role of the liquid phase in bringing about the exothermic effect. At the frist stage of liquid phase sintering the diffusion of atoms from the melt into the solid causes the powder body to grow. At the second stage the diminution of particles in size as a result of their dissolution in the liquid draws their centres closer to each other and makes the compact to shrink Analytical equations were derived to describe quantitatively the porosity and volume changes of compacts as a result of alloy formation during liquid phase sinteIing. Selection criteria for an additive, its concentration and the temperature regime of sintering to control the density the structure of sintered alloys are given.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.396-402
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• 2004

For industrial application to manufacturing functional foods for health using browned oak mushroom, we examined its reducing power, inhibitory effect on intracellular reactive oxygen species, phenolic compounds and phytates contents, modulatory effects on NO radical and matrix metalloproteinase 9 (MMP9) generation by activated macrophages, and antimutagenicity in order to evaluate the functionality of browned oak mushroom for health. While overall ethanolic extracts have higher reducing power than aqueous extracts, browning reaction was found to increase reducing power by up to 28% at a 3.32 mg/ml sample concentration. Browning reaction also increased phenolic compound content by about 73% compared to raw mushroom. However, any significant change in phytate content could not be detected. At a concentration of $100\;{\mu}g/ml$, treatment of ethanolic extract of oak mushroom increased NO generation over 43% in LPS-stimulated macrophage. On the contrary, the aqueous extracts rather decreased it over 17% at the same sample dose. However, any solvent extract from browned oak mushroom seems not to cause any change in both NO production and MMP9 activity. In addition, browning reaction did not allow any significant change in suppressive effect on mitomycin C-induced mutagenesis as examined with SOS chromotest. These results suggest a possible use of browned oak mushroom with unmarketable quality as a material for development of a variety of processed functional foods for health.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.373-378
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• 2003

This research was conducted to investigate the possibilities of usage of rose (Rosa hybrida L. cv. Mary Devor) by examining th antioxidative and antimicrobial activities of extracts with various levels of ethanol concentrates. Proximate composition, dietary fiber, and flavonoids contents were analyzed, and total antioxidant status and yield ratios of extraction of rose were measured. The rose extracts were extracted in different level of ethanol concentrates (0, 75, 85, 95%), and peroxide value, acid value, and TBA value were investigated in different level of concentrates of extracts added and time duration of storage. The results were as follows; derivation period from measuring peroxide value showed that the rose (Petal & Calyces) extract-added group showed longer derivation period than the control group, tocopherol-added, or BHT-added groups, and it proved to be a highly effective antioxidant as a result. It showed the longest derivation period especially when 85% ethanol extract was added with concentration of 0.05%. For the acid values and TBA values of the extract added oil, the rose extract-added group and BHT-added group showed lower values than the control group and tocopherol-added group as th length of time for storage becomes longer. In fact, the rose extracts suggested the possibility to be used as a natural antioxidants as it showed high antioxidative effect similar to BHT. Overall, the rose extracts from each solvent showed high antimicrobial effects against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus than control group. Especially, 85% ethanol extract showed significantly high antimicrobial effect against Escherichia coli.