• Transactions of the Korean hydrogen and new energy society
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• v.24 no.2
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• pp.99-106
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• 2013

The variations of performance and metabolites at an early stage were investigated for the successful start-up technology in continuous fermentative hydrogen production. Unsuccessful start-up was observed when the operation mode was changed from batch to continuous mode after the yield was reached to 0.5 mol $H_2$/mol $hexose_{added}$ by batch mode. $H_2$ production continued till 12 hours accompanied by butyrate production, but did not last with propionate production increase. It was suspected that the failure was due to the regrowth of propionic acid bacteria during batch mode which were inhibited by heat-shock but not completely killed. Thus, successful start-up was tried by early switchover from batch to continuous operation; continuous operation was started after the $H_2$ yield was reached to 0.2 mol $H_2$/mol $hexose_{added}$ by batch mode. Although $H_2$ production rate decreased at an early stage, stable $H_2$ yield of 0.8 mol $H_2$/mol $hexose_{added}$ was achieved after 10 days by lowering down propionate production. And it was also concluded that the reason for $H_2$ production decrease at an early stage was due to alcohol production by self detoxification mechanism against VFAs accumulation.

• Korean Journal of Veterinary Research
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• v.24 no.1
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• pp.58-63
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• 1984

Fecal material from cattle, which was confirmed to be infected with Johne's disease by clinical and pathological symptoms, was decontaminated with 4% NaOH and inoculated into the $L{\ddot{o}}wenstein$-Jensen media supplemented with 1% of heat-killed Mycobacterium bovis. After 2-4 week-incubation at $37^{\circ}C$, typical acid-fast mycobacteria was isolated. With the results of staining properties, morphological characteristics, the requirement of mycobactin for growth and the other biochemical properties, isolated mycobacteria was identified as Mycobacterium paratuberculosis. Female guinea pigs were sensitized with the isolates, and skin test was done with purified protein derivatives (PPDs) of M. avium, M. bovis and M. paratuberculosis 4 weeks after sensitization. Animals showed the largest reaction to the PPDs of M. avium and M. paratuverculosis.

• Korean Journal of Microbiology
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• v.6 no.3
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• pp.92-92
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• 1968

1) The aim of present investigation is to elucidate the relation of the balance of the production and decomposition of the fir litter. in Kwangnung plantation stands. 2) The decay constant, K, of litters was 0. 185 for the fir stand at Kwangnung. 3) The mode for the accumulation of organic carbon ($C_a$) is $c_a$= $610(1-e^{-0.185t})$), and for the decay of organic carbon (C) C = $610(1-e^{-0.185t})$. 4) The time required for the decay of half of the accumulated organic carbon in the fir stand is 3. 74 years and for 99% of elimination 27.02 years. 5) The litters of Abies holophylla killed by heat and washed with alcohol-benzol, with hot water, or with both alcohol-benzol and hot water were incubated after inoculated with suspension of firwood soil. Plate counts were made of fungi and bacteria from time to time. 6) Removal of the alcohol-benzol soluble substance stimulates at the beginning of the decay the growth of fungi and also of bacteria. 7) Removal of the water soluble fraction is detrimental to the growth of fungi in particular. 8) The distribution of soil microbial population is higher in both F and H horizon of the fir plantation soil in Kwangnung. However, the number of soil microorganisms decreases with the depth in forest soil.

• Korean Journal of Microbiology
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• v.6 no.3
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• pp.93-99
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• 1968

1) The aim of present investigation is to elucidate the relation of the balance of the production and decomposition of the fir litter. in Kwangnung plantation stands. 2) The decay constant, K, of litters was 0. 185 for the fir stand at Kwangnung. 3) The mode for the accumulation of organic carbon ($C_a$) is $c_a$= $610(1-e^{-0.185t})$), and for the decay of organic carbon (C) C = $610(1-e^{-0.185t})$. 4) The time required for the decay of half of the accumulated organic carbon in the fir stand is 3. 74 years and for 99% of elimination 27.02 years. 5) The litters of Abies holophylla killed by heat and washed with alcohol-benzol, with hot water, or with both alcohol-benzol and hot water were incubated after inoculated with suspension of firwood soil. Plate counts were made of fungi and bacteria from time to time. 6) Removal of the alcohol-benzol soluble substance stimulates at the beginning of the decay the growth of fungi and also of bacteria. 7) Removal of the water soluble fraction is detrimental to the growth of fungi in particular. 8) The distribution of soil microbial population is higher in both F and H horizon of the fir plantation soil in Kwangnung. However, the number of soil microorganisms decreases with the depth in forest soil.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.373-377
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• 2011

Fire patterns have been used to determine the origin and cause of fires in every setting imaginable. However, it is very difficult to identify fire patterns from the fire-damaged remains of a devastated structure. If someone was killed by the fire, it is possible to identify fire patterns by analyzing the concentration of carbon monoxide-hemoglobin in the body of deceased as well as the pace of the fire. For example, a low level of carbon monoxide-hemoglobin in the body of the dead indicates a rapid fire with accelerants and the death was caused by severe heat and thick toxic fumes. However, a high level of carbon monoxide-hemoglobin in the body of the dead demonstrates that the fire was slow and/or there was a flameless form of combustion. Thus, this study identifies fire patterns through analyzing the level of carbon monoxide-hemoglobin concentration on the dead from the fire.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.839-848
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• 2018

Coptis chinensis (CC) is widely used in Asian countries to treat inflammatory diseases. We investigated the anti-inflammatory activity of the aqueous fraction separated from CC extract and of berberine, its key bioactive component, in human keratinocytes and the possible molecular mechanisms underlying this. Treating HaCaT keratinocytic cells with heat-killed Propionibacterium acnes induced nitric oxide and proinflammatory cytokine (e.g., tumor necrosis $factor-{\alpha}$, interleukin $(IL)-1{\beta}$, and IL-8) production and their mRNA expression; these effects were suppressed by pretreatment with the aqueous fraction or berberine, which also suppressed the phosphorylation of ERK, JNK, and p38 kinases and the nuclear expression of nuclear factor $(NF)-{\kappa}B$ p65 in P. acnes-stimulated cells. Thus, the aqueous fraction and berberine effectively exerted anti-inflammatory activities by suppressing mitogen-activated protein kinase and $NF-{\kappa}B$ signaling pathways in human keratinocytes and may be used for treating P. acnes-induced inflammatory skin diseases.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.405-409
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• 2005

Cellular components of Lactococcus lactis ssp. lactis (heat-killed whole cells, cytoplasm, and cell walls) were tested for their in vivo immunopotentiating activities. Peritoneal macrophages from mice injected intraperitoneally with cell-wall fractions exhibited significantly greater phagocytic activity than groups injected with whole cells or cytoplasm fraction. Cytotoxicity of natural-killer cells was highest in cytoplasm fractions. Production of cytokines (IFN-${\gamma}$, IL-2, IL-6, and IL-12) in spleen cells was significantly higher when cellular components were injected intraperitoneally, and tended to be higher in whole-cell and cytoplasm groups than in cell-wall group. These results demonstrate lactic acid bacteria whole cells and their cytoplasm and cell-wall tractions have immunopotentiating activities.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1827-1834
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• 2020

Candida albicans is a major fungal pathogen in humans. In our previous study, we reported that an ethanol extract from Aucklandia lappa weakens C. albicans cell wall by inhibiting synthesis or assembly of both (1,3)-β-D-glucan polymers and chitin. In the current study, we found that the extract is involved in permeabilization of C. albicans cell membranes. While uptake of ethidium bromide (EtBr) was 3.0% in control cells, it increased to 7.4% for 30 min in the presence of the A. lappa ethanol extract at its minimal inhibitory concentration (MIC), 0.78 mg/ml, compared to uptake by heat-killed cells. Besides, leakage of DNA and proteins was observed in A. lappa-treated C. albicans cells. The increased uptake of EtBr and leakage of cellular materials suggest that A. lappa ethanol extract induced functional changes in C. albicans cell membranes. Incorporation of diphenylhexatriene (DPH) into membranes in the A. lappa-treated C. albicans cells at its MIC decreased to 84.8%, after 60 min of incubation, compared with that of the controls, indicate that there was a change in membrane dynamics. Moreover, the anticandidal effect of the A. lappa ethanol extract was enhanced at a growth temperature of 40℃ compared to that at 35℃. The above data suggest that the antifungal activity of the A. lappa ethanol extract against C. albicans is associated with synergistic action of membrane permeabilization due to changes in membrane dynamics and cell wall damage caused by reduced formation of (1,3)-β-D-glucan and chitin.

• Food Science of Animal Resources
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• v.41 no.2
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• pp.261-273
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• 2021

Leuconostoc mesenteroides H40 (H40) was isolated from kimchi, and its probiotic properties and neuroprotective effect was evaluated in oxidatively stressed SH-SY5Y cells. H40 was stable in artificial gastric conditions and can be attached in HT-29 cells. In addition, H40 did not produce β-glucuronidase and showed resistant to several antibiotics. The conditioned medium (CM) was made using HT-29 cells refined with heat-killed probiotics (Probiotics-CM) and heated yogurts (Y-CM) to investigate the neuroprotective effect. Treatment with H40-CM not only increased cell viability but also significantly improved brain derived neurotropic factor (BDNF) expression and reduced the Bax/Bcl-2 ratio in oxidatively stress-induced SH-SY5Y cells. Besides, probiotic Y-CM significantly increased BDNF mRNA expression and decreased Bax/Bcl-2 ratio. The physicochemical properties of probiotic yogurt with H40 was not significantly different from the control yogurt. The viable cell counts of lactic acid bacteria in control and probiotic yogurt with H40 was 8.66 Log CFU/mL and 8.96 Log CFU/mL, respectively. Therefore, these results indicate that H40 can be used as prophylactic functional dairy food having neuroprotective effects.

• Fire Science and Engineering
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• v.30 no.3
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• pp.48-54
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• 2016

Pilotis are support columns that lift a building above the ground. Thus, they can elevate the lowest floor to the secondfloor level and, in Korea, are used to leav a parking area below multifamily housing. However, if there is a fire in the piloti area, the cars and main entrance door are wrapped in flames. Due to the inflammability of the materials, the combustion of the cars and insulation at the ceiling of the pilotis, having a high heat release rate, can quickly destroy the front entrance of the building and spread heat, flames and a poisonous gas to the stairs and elevator pit. Therefore, the fire can quickly spread to the whole building, putting the lives of the residents in danger. This study was an in-depth accidental case study of the "Uijeongbu Fire Accident" that killed 5 residents and injured 139 others. The study identified the relationships between the fire at the piloti structure of multifamily housing and the vulnerability of this structure and its inherent weaknesses.