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        검색결과 16

        1.
        2022.10 구독 인증기관·개인회원 무료
        Waste containers for packaging, transportation and disposal of NPP (Nuclear Power Plant) decommissioning wastes are being developed. In this study, drop tests were conducted to prove the safety of containers for packaging of the wastes and to verify the reliability of the analysis results by comparing the test and analysis results. The drop height of the waste containers was considered to be 30 mm, which is the maximum lifting speed of a 50 tons crane in the waste treatment facility converted to the drop height. Drop orientation of the containers was considered for bottom-end on drop. The impact acceleration and strain data were obtained to verify the reliability of the analysis results. Before and after the drop tests, measurement of the dose rate and the radiographic testing for concrete wall, and measurement of the wall thickness of steel plate were conducted to evaluate the radiation shielding integrity. Also, measurement of bolt torque, and visual inspection were conducted to evaluate the loss or dispersion of radioactive contents. After the drop tests, the radiation dose rate on the container surface did not increase by more than 20%, and there was no crack in the concrete. In addition, the thickness of the steel plate did not change within the measurement error. Therefore, the radiation shielding integrity of the container was maintained. After the drop tests, the lid bolts were not damaged and there was no loss of pretension in the lid bolts. In addition, there was no loss or dispersion of the contents as a result of visual inspection. In order to prove the reliability of the drop analysis results, safety verifications were performed using the drop test results, and the appropriate conservatism for the analysis results and the validity of the analysis model were confirmed. Therefore, the structural integrity of the waste containers was maintained under the drop test conditions.
        4.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        11.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to identify medicinal mushrooms with protective effects against oxidative stress in PC12 neuronal cell line, followed by evaluation of their antioxidant property. Extracts of medicinal mushrooms, including Ganoderma lucidum extract (GLE), antler-shaped Ganoderma lingzhi extract (AGLE), Hericium erinaceus extract (HEE), and Sanghuangporus baumii extract (SBE), were screened for cytotoxicity using MTT assay. None of the extracts up to 10 μg/ml concentration affected cell viability. These extracts were further checked for their protective effect against oxidative stress-induced reactive oxygen species (ROS) production. Exposure to 50 μM H₂O₂ induced ROS generation in PC12 cells, which was inhibited only by treatment with AGLE. In addition, inhibition of H₂O₂-induced ROS generation by AGLE was found to be in a dose-dependent manner (2.5, 5, and 10 μg/ml). Microscopic examination of DCF fluorescence for detection of ROS showed a similar pattern. Further, antioxidant activity of AGLE was determined by ABTS radical cation assay, and its IC50 was found to be 46.90±0.31 μg/ml. Taken together, these results suggest that AGLE may help to alleviate oxidative stress in PC12 neuronal cells.
        4,000원
        12.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ultraviolet B (UVB) exposure is a risk factor for skin damage resulting in oxidative stress, inflammation, and cell death. The purpose of this study was to investigate the physicochemical properties of Platycodon grandiflorum (PG) to improve its biological activities using a three-step steaming process. We investigated the protective effects of PG and steamed PG extracts on human dermal fibroblasts (HDFs) against UVB radiation-induced oxidative stress and inflammation as well as the underlying mechanisms. The antioxidant potential of the PG extracts was evaluated by measuring the 2,2-diphenyl-1- picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) scavenging activity. ABTS and DPPH were shown by the 0, 30, and 70% ethanol extracts of 2S-PG and 3S-PG (IC50, 28~45 and 27~30 μg/mL, respectively). Treatment of UVB-irradiated cells with steamed PG (25~400 μg/mL) did not affect their viability. The streamed PG extract suppressed UVB-induced generation of reactive oxygen species (ROS). In addition, streamed PG extract reduced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein expression in UVB-irradiated HDF, regulating nuclear factor (NF)-κB expression. These findings suggest that steamed PG extract may be potentially effective against inflammation associated with UVB-induced oxidation stress.
        4,000원
        16.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        Mushrooms have been widely cultivated and consumed as foods and herbal medicines owing to their various biological properties. However, few studies have evaluated the anti-inflammatory effects of mushrooms. Here, we investigated the effects of mushroom extracts (MEs) on lipopolysaccharide (LPS)-induced inflammation in macrophages (RAW264.7 cells). First, we extracted MEs with either water or ethanol. Using LPS-treated RAW264.7 cells, we measured cell proliferation and NO production. Gene expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 (IL-6), and IL-1β was assessed by RT-PCR, and protein abundance of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) and phosphorylation of p65 were determined by immunoblotting. MEs prepared using both water and ethanol inhibited LPS-induced inflammation in RAW264.7 cells. Nitric oxide (NO) levels induced by LPS were reduced by treatment with MEs. Isaria japonica Yasuda water extracts and Umbilicaria esculenta (Miyoshi) Minks ethanol extracts significantly decreased the mRNA expression of inflammation-related cytokine genes including TNF-α, IL-6, and IL-1β. Similarly, the protein abundance of iNOS and COX-2 was also decreased. The phosphorylation of p65, a subunit of nuclear factor-κB was at least partly suppressed by MEs. This study suggests that mushrooms could be included in the diet to prevent and treat macrophage-related chronic immune diseases.