• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1057-1060
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• 2004

In this study, the wear characteristics of five different dental composite resins cured by conventional halogen light and LED light sources were investigated. Five different dental composite resins of Surefil, Z100, Dyract AP, Fuji II LC and Compoglass were worn against a zirconia ceramic ball using a pin-on-disk type wear tester with 15 N contact force in a reciprocal sliding motion with sliding distance of 10 mm/cycle at 1Hz under the room temperature dry condition. The wear variations of dental composite resins were linearly increased as the number of cycles increased. It was observed that the wear resistances of these specimens were in the order of Dyract AP ＆gt; Surefil ＆gt; Compoglass ＆gt; Z100 ＆gt; Fuji II LC. On the morphological observations by SEM, the large crack formation on the sliding track of Fuji II LC specimen was the greatest among all resin composites. Dyract AP showed the least wear with few surface damage. There is no significant difference in wear performance between conventional halogen light curing and light emitting diodes curing sources. It indicates that a light emitting diodes (LED) source can replace a halogen light source as a curing unit for composite resin restorations.

• Journal of Sericultural and Entomological Science
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• v.7
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• pp.53-63
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• 1967

In order to identify the bacteria living on the cocoons in Korea, the isolated bacterias' morphological. cultural and physiological characters has been determined through the detailed study. The second aim of this experiment was to protect against the bacteria which damage silk protein during storage. 1. The twelve strains of the bacteria were isolated and identified in the cocoons produced in Korea. The results of the identification are as the following. No 1, No 8; Bacillus subtilis variation No 2, ; Bacillus stearothermophilus No 3, ; Bacillus circulans No 5, No 6; Bacillus thuringiensis No 7, No 11; Bacillus brevis No 12, No l0; Bacillus cereus variation

• Nutritional Sciences
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• v.6 no.1
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• pp.20-24
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• 2003

The effect of a-tocopherol on the formation and accumulation of phospholipid hydroperoxides, especially of phosphatidylcholine hydroperoxides, in the tissues of 2, 2 -azobis Hydrochloride (AAPH) - dosed rats was investigated. In a-tocopherol supplemented rats, the activities of glutathione peroxidase, catalase and superoxide dismutase were significantly inhibited, compared with the AAPH group. AAPH treatment led to oxidation of phospholipids in the liver, lungs, brain, plasma and red blood cells (RBC), resulting in a notable increase in phosphatidylcholine hydroperoxide (PCOOH). All tissues of the rats given an $\alpha$-tocopherol supplement showed an attenuation of the stimulating effect of AAPH, leading to low levels of formation of PCOOH. Also, the rats injected with AAPH and a-tocopherol showed relatively normal-appearing hepatocytes, except for a little loss of the granules. With regards to the morphological appearance of the liver, it was observed that oral intakes of a -tocopherol resulted in an antioxidant defense against attacks of peroxyl radicals. Thus, we suggest that a-tocopherol is potentially helpful in protecting membrane phospholipids against oxidative damage in vivo.

• ALGAE
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• v.20 no.4
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• pp.363-368
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• 2005

The brown alga Ascophyllum nodosum and its mutualistic, ascomycete symbiont, Mycophycias ascophylli, form a complex ‘rganism’or symbiotum. Here we show the interaction of the symbiotum to the abundant brown algal epiphyte, Elachista fucicola. Microscopy of field-collected plants shows morphological responses of A. nodosum to the common epiphyte E. fucicola. When E. fucicola attaches to A. nodosum a bundle of several to dozens of rhizoids penetrates into the host. On the surface of the host, the cells proliferate to form a donut-shaped ring, 100-200 μm in height that surrounds the thallus of E. fucicola. A pit forms in advance of the rhizoids and the cells of A. nodosum break down. This leaves the network of fungal hyphae partially intact and intermingling with the epiphyte rhizoids and its lowermost cells. After the pit is formed, the cells of A. nodosum bordering the infection chamber redifferentiate an epidermal layer. Neither the host nor its mutualistic fungus, M. ascophylli appears to recognize E. fucicola as an invader and to prevent the attachment and growth of this epiphyte. Based on the physical damage to the host caused by invading rhizoids, we conclude that the relationship of E. fucicola to A. nodosum is that of a parasite and its host.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.586-591
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• 2015

BACKGROUND/OBJECTIVES: Reactive oxygen species (ROS) formation is closely related to miconazole-induced heart dysfunction. Although rhamnetin has antioxidant effects, it remained unknown whether it can protect against miconazole-induced cardiomyocyte apoptosis. Thus, we investigated the effects of rhamnetin on miconazole-stimulated H9c2 cell apoptosis. MATERIALS/METHODS: Cell morphology was observed by inverted microscope and cell viability was determined using a WelCount$^{TM}$ cell proliferation assay kit. Miconazole-induced ROS production was evaluated by fluorescence-activated cell sorting with 6-carboxy-2',7'-dichlorofluoroscein diacetate ($H_2DCF$-DA) stain. Immunoblot analysis was used to determine apurinic/apyrimidinic endonuclease 1 (APE/Ref-1) and cleaved cysteine-aspartic protease (caspase) 3 expression. NADPH oxidase levels were measured using real-time polymerase chain reaction. RESULTS: Miconazole (3 and $10{\mu}M$) induced abnormal morphological changes and cell death in H9c2 cells. Rhamnetin enhanced the viability of miconazole ($3{\mu}M$)-treated cells in a dose-dependent manner. Rhamnetin (1 and $3{\mu}M$) treatment downregulated cleaved caspase 3 and upregulated APE/Ref-1 expression in miconazole-stimulated cells. Additionally, rhamnetin significantly reduced ROS generation. CONCLUSIONS: Our data suggest that rhamnetin may have cytoprotective effects in miconazole-stimulated H9c2 cardiomyocytes via ROS inhibition. This effect most likely occurs through the upregulation of APE/Ref-1 and attenuation of hydrogen peroxide levels.

• Journal of Information Display
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• v.7 no.2
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• pp.22-25
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• 2006

This paper presents heating process for obtaining standing carbon nanotube emitters to improve field-emission properties from the screen-printed multiwalled carbon nanotube (MWCNT) films. In an atmosphere with optimum combination of nitrogen and air for heat treatment of CNT films, the CNT emitters can be made to protrude from the surface. This allows for high emission current and the formation of very uniform emission sites without special surface treatment. The morphological change of the CNT film by this technique has eliminated additional processing steps, such as surface treatment which may result in secondary contamination and damage to the film. Despite its simplicity the process provides high reproducibility in emission current density which makes the films suitable for practical applications.

• BMB Reports
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• v.46 no.1
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• pp.31-36
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• 2013

Heat shock proteins play an important role in plant stress tolerance and are mainly regulated by heat shock transcription factors (Hsfs). In this study, we generated transgenic rice over-expressing OsHsfA7 and carried out morphological observation and stress tolerance assays. Transgenic plants exhibited less, shorter lateral roots and root hair. Under salt treatment, over-expressing OsHsfA7 rice showed alleviative appearance of damage symptoms and higher survival rate, leaf electrical conductivity and malondialdehyde content of transgenic plants were lower than those of wild type plants. Meanwhile, transgenic rice seedlings restored normal growth but wild type plants could not be rescued after drought and re-watering treatment. These findings indicate that over-expression of OsHsfA7 gene can increase tolerance to salt and drought stresses in rice seedlings.

• BMB Reports
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• v.31 no.2
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• pp.183-188
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• 1998

2-chloroethylethyl sulfide (CEES) is an alkylating agent that readily reacts with a wide variety of biological molecules causing metabolic abnormality. The mechanism of cell death during CEES injury is poorly understood. We have examined the effect of exposure of thymocytes with various concentrations of CEES to determine the pattern of cell death in thymocytes injury induced by CEES. In the present study, we show that two patterns of cell death occurred by either one of two mechanisms: apoptosis and necrosis. Exposure to low level of CEES (100 ${\mu}M$) for 5 h caused an induction of apoptosis on thymocytes, as identified by the following criteria: DNA fragmentation visualized by the characteristic "ladder" pattern was observed upon agarose gel electrophoresis and morphological features were revealed by microscopical observations. In contrast, exposure to high levels of CEES (500 ${\mu}M$) induce necrotic features such as cell lysis. Thus, depending on the concentrations, CEES can result in either apoptotic or necrotic cell damage. Our findings suggest that thymocytes which are not killed directly, but merely injured by low levels of CEES, are able to activate an internally-programmed cell death mechanism, whereas thymocytes receiving severe damages apparently can not.

• The Plant Pathology Journal
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• v.32 no.2
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• pp.157-161
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• 2016

Gamma irradiation was evaluated for its in vitro and in vivo antibacterial activity against a postharvest bacterial pathogen, Erwinia carotovora subsp. carotovora (Ecc). Gamma irradiation in a bacteria cell suspension resulted in a dramatic reduction of the viable counts as well as an increase in the amounts of DNA and protein released from the cells. Gamma irradiation showed complete inactivation of Ecc, especially at a dose of 0.6 kGy. In addition, scanning electron microscopy of irradiated cells revealed severe damage on the surface of most bacterial cells. Along with the morphological changes of cells by gamma irradiation, it also affected the membrane integrity in a dose-dependent manner. The mechanisms by which the gamma irradiation decreased the bacterial soft rot can be directly associated with the disruption of the cell membrane of the bacterial pathogen, along with DNA fragmentation, results in dose-dependent cell inactivation. These findings suggest that gamma irradiation has potential as an antibacterial approach to reduce the severity of the soft rot of paprika.

• Fashion & Textile Research Journal
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• v.7 no.1
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• pp.70-74
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• 2005

This study was aimed to isolation and identification of attached bacteria on the clothes excavated from Deajeon area dating on the 16th century. From the observation with colony shape, 17 bacterial strains were isolated, and then 7 bacterial strains were identified with morphological and biochemical characteristics. Streptococcus sp., Alcaligenes faecalis, Gemella sp., Acinetobacter sp., Pseudomonas vesicularis, Aeromonas sain. salmonicida, Moraxella spp. In observation of the bacterial strains by the sort of textile, more bacterial strains were found in silk, cotton, and cotton batt than in ramie and hemp. It is suggest that hemp has antibacterial characteristics due to the presence of lignin. In the comparison washed samples with unwashed ones, there were more kinds of bacterial strains in washed samples. In the cellulase activity tests, all isolated bacteria had low level cellulase activity.