• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.617-624
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• 2017

Chocolate, one of the most popular confectioneries in the world, is known for its aromatic flavor and high antioxidant activities. In this study, we investigated the effects of fermentation with commercially available lactic acid bacteria, ABT-5, on the flavor and antioxidant activities of dark chocolate. During 24 h fermentation, pH decreased from 5.52 to 3.97 and total acidity increased from 0.51 to 1.85%, whereas total polyphenol and flavonoid contents as well as DPPH and ABTS radical scavenging activities remained unchanged. Furthermore, compared with control HepG2 cells treated with unfermented dark chocolate, those treated with the fermented dark chocolate showed significantly lower levels of reactive oxygen species and higher viability under $H_2O_2-induced$ oxidative stress. Finally, GC-MS and headspace GC-MS analysis detected 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 2-furanmethanol, known to enhance flavor, in the fermented dark chocolate. Collectively, these results suggest that ABT-5-fermented dark chocolate could be utilized for developing value-added dark chocolate products.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.425-429
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• 2014

Two dogs were presented with a history of anorexia, respiratory distress, or epistaxis. On physical examination, the dogs showed difficulty breathing and open-mouth breathing and large masses were found on the hard palate and soft palate. Cardiac arrest happened in case 2 and the dog was stabilized with cardiopulmonary resuscitation and oxygen therapy. Computed tomography demonstrated that the mass occupied the oropharynx, intrapharyngeal ostium, and laryngopharynx including the hard palate and soft palate in case 1. Palliative surgery was decided to improve swallowing and breathing with owner's consent in two dogs. Buccal mucosal flaps were performed for reconstruction of defects using rotational and single-pedicle advancement flaps and bilateral 90 degree transposition flaps in cases 1 and 2, respectively. Histopathology results described the oral masses as amelanotic melanoma in two dogs. The owners reported that there was normal swallowing and breathing at 7 days postoperatively in two dogs. In case 1, recurrent tumor was identified caudal to the hard palate 4 weeks after surgery. The owner did not allow further treatment and the dog became lost to follow-up at 2 months postoperatively. In case 2, there was no clinical or radiographic evidence of a local recurrence or distant metastasis at 3 weeks after surgery. The owner informed that the dog died suddenly with no signs of anything particularly wrong at 7 weeks after surgery.

• YAKHAK HOEJI
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• v.45 no.5
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• pp.513-521
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• 2001

The chronic cholestasis induce to biliary liver fibrosis (cirrhosis) and the increased products of ROS(reactive oxygen species) cause to the liver damage. In this study ; the antioxidant and antifibrotic effect of dried extracts of oriental medicine (DW) was investigated under the liver fibrotic (cirrhotic) condition. The female Sprague-Dawley rats were divided in 5 groups (Normal, Op-2, Op-4, OpDW-2, OpDW-4). Except for normal group, the rats were induced to biliary liver fibrosis (cirrhosis) by the operation of bile duct ligation/scission (BDU/S) and were observed in 2 weeks or 4 weeks. And the prepared DW was treated p.o.2 ml/day/rats in 2 weeks or 4 weeks for OpDW groups. At the time of sacrifice, the liver, kidney, spleen were weighed and the ratio of organ weight/body weight was calculated. The MDA, the hyp and biochemical parameters (GOT GTP, ALP, t-bili) were measured in sera and liver tissue of rats. The biochemical change was observed on liver tissue. In the result, the hepatomegaly and spleenomegaly appeared in all BDL/S operated rats, and significantly lower liver weight was observed in OpDW-4 group compared with in Op-4 group (p<0.05). The level of clinical parameters in sera of all liver fibrosis (cirrhosis) developed rats was higher than in normal group. Especial1y, the value of GOT in OpDW-2 group and ALP in OpDW-4 group showed significantly lower than in Op-2 group and Op-4 group (p<0.01, p<0.005). The content of hyp in all operation groups was significantly higher than in normal group (p<0.05∼<0.005), and showed significantly lower value in the OpDW-4 group than in Op-4 group (p<0.05). The product of lipid peroxidationUDA) increased significantly under the fibrotic(cirrhotic) condition (p<0.05∼ <0.005), and the MDA value in OpDW-4 group decreased significantly in Op-4 group (p<0.005). The histological change (bile duct proliferation, fibrosis, collagen bundle) was similarly observed in Op-2 group and in OpDW-2 group, but the weak fibrosis and bile duct proliferation were observed in OpDW-4 group compared with in Op-4 group. In conclusion, lipid peroxidation and severe liver damage were activated by bile duct obstruction, and the measurement of MDA and hap can be useful monitor for the screening of antioxidant and antifibrotic effect in experimental liver fibrosis (cirrhosis). The 4 weeks treatment with DW extracts suppressed lipid peroxidation and inhibited fibrotic (cirrhotic) process in BDL/S operated rats.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.175-184
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• 2022

The present study investigated the neuroprotective effects of Coreopsis lanceolate extract against hydrogen-peroxide (H₂O₂)-induced oxidative damage and cell death in pheochromocytoma 12 (PC12) cells. Reactive oxygen species (ROS), 2,2'-azinobis (3-ethylbebzothiazoloine-6-sulfonic acid) diammonium salt, and 1,1-diphenyl-2-picrrylhydrazyl radical scavenging activities, as well as the expression levels of proteins associated with oxidative damage and cell death were investigated. According to the results, C. lanceolate extract exhibited inhibitory activity against intracellular ROS generation and cell-damaging effects induced by hydroxyl radicals in a dose-dependent manner. Total phenolic and flavonoid contents were 22.3 mg·g^-1 gallic acid equivalent and 16.2 mg·g^-1 catechin equivalent, respectively. Additionally, a high-performance liquid chromatography (HPLC) assay based on the internal standard method used to detect phenolic compounds. The phenolic compounds identified in C. lanceolata extract contained (+)-catechin hydrate (5.0 ± 0.0 mg·g^-1), ferulic acid (1.6 ± 0.0 mg·g^-1), chlorogenic acid (1.5 ± 0.0 mg·g^-1), caffeic acid (1.2 ± 0.0 mg·g-1), naringin (0.9 ± 0.0 mg·g^-1), and p-coumaric acid (0.5 ± 0.0 mg·g^-1). C. lanceolata extract attenuated pro-apoptotic Bax expression levels and enhanced the expression levels of anti-apoptotic Bcl-2, caspase-3, and caspase-9 proteins. Therefore, C. lanceolata is a potential source of materials with neuroprotective properties against neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases.

• Korean Journal of Materials Research
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• v.10 no.9
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• pp.601-606
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• 2000

Nickel mono-silicide(NiSi) shows no increase of resistivity as the line width decreases below 0.15$\mu\textrm{m}$. Furthermore, thin silicide can be made easily and restrain the redistribution of dopants, because NiSi in created through the reaction of one nickel atom and one silicon atom. Therefore, we investigated the deposition condition of Ni films, heat treatment condition and basic properties of NiSi films which are expected to be employed for sub-0.15$\mu\textrm{m}$ class devices. The nickel silicide film was deposited on the Si wafer by using a dc-magnetron sputter, then annealed at the temperature range of $150~1000^{\circ}C$. Surface roughness of each specimen was measured by using a SPM (scanning probe microscope). Microstructure and qualitative composition analysis were executed by a TEM-EDS(transmission electron microscope-energy dispersive x-ray spectroscope). Electrical properties of the materials at each annealing temperature were measured by a four-point probe. As the results of our study, we may conclude that; 1. SPM can be employed as a non-destructive process to monitor NiSi/NiSi$_2$ transformation. 2. For annealing temperature over $800^{\circ}C$, oxygen pressure $Po_2$ should be kept below $1.5{\times}10^{-11}torr$ to avoid oxidation of residual Ni. 3. NiSi to $NiSi_2$ transformation temperature in our study was $700^{\circ}C$ from the four-point probe measurement.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.433-441
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• 2013

In this study, the anti-oxidative, anti-inflammatory, anti-melanogenic activities of Endlicheria anomala (Nees) Mez methanol extract (EAME) were evaluated by use of in vitro assays and cell culture model systems. The results revealed that EAME scavenges various radicals such as 1,1-diphenyl-2-picryl hydrazyl hydrogen peroxide induced reactive oxygen species, and lipopolysaccharide induced nitric oxide. Furthermore, EAME induced the expression of anti-oxidative enzymes such as heme oxygenase 1, thioredoxin reductase 1, NAD(P)H dehydrogenase 1, and their upstream transcription factor, nuclear factor-E2-related factor 2. Moreover, EAME inhibited in vitro DOPA oxidation and 3-isobutyl-1-methylxanthine induced melanogenesis in B16F10 cells. Its anti-melanogenic activity will have originated from the inhibition of tyrosinase enzyme activity and melanogenesis related protein expression. Taken together, these results provide the important new insight that E. anomala possesses various biological activities such as anti-oxidative, anti-inflammatory, and anti-melanogenic. Therefore, it might be utilized as a promising material in the fields of nutraceuticals and cosmetics.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.32-33
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• 2003

Mechanism of a periodic oscillation of shock-induced combustion over a two- dimensional wedges and axi-symmetric cones were investigated through a series of numerical simulations at off-attaching condition of oblique detonation waves(ODW). A same computational domain over 40 degree half-angle was considered for two-dimensional and axi-symmetric shock-induced combustion phenomena. For two-dimensional shock-induced combustion, a 2H2+02+17N2 mixture was considered at Mach number was 5.85with initial temperature 292 K and initial pressureof 12 KPa. The Rankine-Hugoniot relation has solution of attached waves at this condition. For axi-symmetric shock-induced combustion, a H2+2O2+2Ar mixture was considered at Mach number was 5.0 with initial temperature 288 K and initial pressure of 200 mmHg. The flow conditions were based on the conditions of similar experiments and numerical studies.[1, 3]Numerical simulation was carried out with a compressible fluid dynamics code with a detailed hydrogen-oxygen combustion mechanism.[4, 5] A series of calculations were carried out by changing the fluid dynamic time scale. The length wedge is varied as a simplest way of changing the fluid dynamic time scale. Result reveals that there is a chemical kinetic limit of the detached overdriven detonation wave, in addition to the theoretical limit predicted by Rankine-Hugoniot theory with equilibrium chemistry. At the off-attaching condition of ODW the shock and reaction waves still attach at a wedge as a periodically oscillating oblique shock-induced combustion, if the Rankine-Hugoniot limit of detachment isbut the chemical kinetic limit is not.Mechanism of the periodic oscillation is considered as interactions between shock and reaction waves coupled with chemical kinetic effects. There were various regimes of the periodicmotion depending on the fluid dynamic time scales. The difference between the two-dimensional and axi-symmetric simulations were distinct because the flow path is parallel and uniform behind the oblique shock waves, but is not behind the conical shock waves. The shock-induced combustion behind the conical shockwaves showed much more violent and irregular characteristics.From the investigation of characteristic chemical time, condition of the periodic instability is identified as follows; at the detaching condition of Rankine-Hugoniot theory, (1) flow residence time is smaller than the chemical characteristic time, behind the detached shock wave with heat addition, (2) flow residence time should be greater than the chemical characteristic time, behind an oblique shock wave without heat addition.

• Journal of Life Science
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• v.27 no.12
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• pp.1452-1461
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• 2017

Melanin production by melanocytes in human hair follicles decreases with time and leads to the graying process, which is a phenotype of human aging and an index of aging. The reduction in melanin production is the result of decreased tyrosinase activity in hair follicles and an accumulation of active oxygen species, such as hydrogen peroxide. This study investigated antioxidant effects and melanin-promoting effects in B16F1 cells treated with black sesame ethanolic nonpolar-soluble extract (SBEEO) and black sesame ethanolic polar-soluble extract (SBEEP). In antioxidation experiments, both SBEEP and SBEEO did not eliminate 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical, but SBEEO at $64{\mu}g/ml$ showed low reducing power. SBEEP exerted cytotoxic effects at concentrations greater than $8{\mu}g/ml$, whereas SBEEO showed cytotoxic effects at concentrations greater than $4{\mu}g/ml$. SBEEP and SBEEO induced melanin synthesis, tyrosinase activity, and DOPA oxidase activity in vitro. In live cells, melanin synthesis was greater in the SBEEP treatment group as compared with that in the SBEEO treatment group. SBEEP stimulated melanin synthesis by modulating the expression of tyrosinase-related protein-2 (TRP-2), which is an important enzyme in melanin synthesis. These results imply that SBEEP obtained from black sesame ethanolic extract may have the potential to improve melanin synthesis.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.2
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• pp.123-129
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• 2015

$^{64}Cu$-labeled diacetyl-bis($N^4$-methylthiosemicarbazone) is a promising agent for internal radiation therapy and imaging of hypoxic tissues. In the study, we confirmed hypoxia regions in VX2 tumor implanted rabbits with injection $^{64}Cu$-ATSM and $^{18}F$-FDG using positron emission tomography (PET)/computed tomography (CT). PET images with $^{18}F$-FDG and $^{64}Cu$-ATSM were obtained for 40 min by dynamic scan and additional delayed PET images of $^{64}Cu$-ATSM the acquired up to 48 hours. Correlation between intratumoral $O_2$ level and $^{64}Cu$-ATSM PET image was analyzed. $^{64}Cu$-ATSM and $^{18}F$-FDG were intravenously co-injected and the tumor was dissected and cut into slices for a dual-tracer autoradiographic analysis. In the PET imaging, $^{64}Cu$-ATSM in VX2 tumors displayed a specific uptake in hypoxic region for48 h. The uptake pattern of $^{64}Cu$-ATSM in VX2 tumor at 24 and 48 h did not match to the $^{18}F$-FDG. Through ROI analysis, in the early phase (dynamic scan), $^{18}F$-FDG has positive correlation with $^{64}Cu$-ATSM but late phase (24 and 48 h) of the $^{64}Cu$-ATSM showed negative correlation with $^{18}F$-FDG. High uptake of $^{64}Cu$-ATSM in hypoxic region was responded with significant decrease of oxygen pressure, which confirmed by $^{64}Cu$-ATSM PET imaging and autoradiographic analysis. In conclusion, $^{64}Cu$-ATSM can utilize for specific targeting of hypoxic region in tumor, and discrimination between necrotic- and viable hypoxic tissue.

• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.86-91
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• 2016

Oxidative stress caused by reactive oxygen species is ascribed to many neurodegenerative diseases like Alzheimer's disease. Phenolic antioxidants can reduce the oxidative stress. In this study, ripe fruits of Opuntia ficus-indica var. saboten (OFS) were extracted using 80% (v/v) aqueous ethanol. Total phenolic and flavonoid contents of the OFS fruits (100 g) were 409.9 mg gallic acid equivalents and 72.2 mg catechin equivalents, respectively. The OFS fruits had antioxidant capacity at 381.2, 298.2, and 3,219.9 mg vitamin C equivalents/100 g in ABTS, DPPH, and ORAC assays, respectively. The OFS fruits showed protective effects on PC-12 cells against oxidative stress in a dose-dependent manner, partly due to decrease of intracellular oxidative stress. Furthermore, the OFS fruits inhibited both acetylcholinesterase and butyrylcholinesterase. Consequently, these results suggest that the OFS fruits might be served as a source of functional materials to reduce oxidative stress in neuronal cells and to inhibit cholinesterases.