검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 2,726

        81.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the effects of heat treatment on gastrodin and gastrodigenin content, and antioxidant activities, in Gastrodia elata Blume. Gastrodin and gastrodigenin content was analyzed post-method validation, and antioxidant activity evaluation, including assessing total polyphenol content, DPPH, and ABTS radical scavenging activities, was done. The validation of the analysis method demonstrated excellent linearity. The limits of quantification of gastrodin and gastrodigenin were 2.89 and 3.47 μg/mL, respectively. Moreover, the results of intra- and inter-day precision analysis demonstrated relative standard deviation values, within 5%. The recovery rates for gastrodin and gastrodigenin were 97.22~98.85 and 97.99~99.91%, respectively, indicating good accuracy. Under different heat treatment conditions, gastrodin and gastrodigenin content significantly increased (p<0.05), ranging from 91.15 to 310.27 and 559.66 to 830.02 mg/100 g DW, respectively. Additionally, the total polyphenol content exhibited a significant (p<0.05) increasing trend, ranging from 1,444 to 1,798 mg/100 g DW, as the temperature and time of heat treatment increased. The DPPH and ABTS radical scavenging abilities demonstrated an increasing trend at 120℃ during heat treatment. These research findings are expected to enhance our understanding of the changes in gastrodin and gastrodigenin content, and antioxidant effects in Gastrodia elata Blume during heat treatment.
        4,000원
        82.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effects of annealing on the microstructure and mechanical properties of Al–Zn–Mg–Cu–Si alloys fabricated by high-energy ball milling (HEBM) and spark plasma sintering (SPS) were investigated. The HEBM-free sintered alloy primarily contained Mg2Si, Q-AlCuMgSi, and Si phases. Meanwhile, the HEBM-sintered alloy contains Mg-free Si and θ-Al2Cu phases due to the formation of MgO, which causes Mg depletion in the Al matrix. Annealing without and with HEBM at 500oC causes partial dissolution and coarsening of the Q-AlCuMgSi and Mg2Si phases in the alloy and dissolution of the θ-Al2Cu phase in the alloy, respectively. In both alloys, a thermally stable α-AlFeSi phase was formed after long-term heat treatment. The grain size of the sintered alloys with and without HEBM increased from 0.5 to 1.0 μm and from 2.9 to 6.3 μm, respectively. The hardness of the sintered alloy increases after annealing for 1 h but decreases significantly after 24 h of annealing. Extending the annealing time to 168 h improved the hardness of the alloy without HEBM but had little effect on the alloy with HEBM. The relationship between the microstructural factors and the hardness of the sintered and annealed alloys is discussed.
        4,000원
        83.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of pectinase treatment and skin contact time on the quality characteristics of Dae-hong peach wine. Wine was produced with variations in enzyme treatment and skin contact time (1 hour, 2 hours, 1 day, 2 days, and until the completion of fermentation). Enzyme treatment increased the production yield by 6%, as well as ethanol and redness levels, compared to the non-treated control. Volatile components were higher when the skin contact time was 2 hours or 1 day. Results were compared according to enzyme treatment and skin contact time and found to be influenced by methanol and 3-methyl-1-butanol. Enzyme treatment effectively enhanced yields and volatile compound contents. However, skin contact should be concluded a day before 1 day to ensure compliance with methanol legislative requirements. Therefore, our findings show that enzymatic treatment with shorter skin contact time preserves the distinctive characteristics of Dae-hong peaches and ensures the production of safe and flavorful wine.
        4,600원
        84.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated quality characteristics and antioxidant activity of beetroots after blanching. Beetroots were blanched in distilled water, 2% NaCl water, and 2% citric acid water at 100°C for 3 minutes (the blanched group). The moisture content was highest in the control (CON) at 91.30% (p<0.05), and cooking loss was lowest in the water-blanched beetroot (BW) at 5.39% (p<0.01). Chromaticity decreased after blanching compared to CON (p<0.001). Total polyphenol contents (TPC) and total flavonoid contents (TFC) decreased after blanching, and as a result of comparing the True retention (TR) of the blanching treatment group, BW had the highest with TPC TR 91.22% and TFC TR 70.51%. DPPH and ABTS+ radical scavenging activities were highest in the CON, and in the blanching group BW was highest scavenging activity. The total number of microorganisms in the CON group was 2.97 log CFU/g, whereas no microorganisms were detected in the blanched groups. Therefore, this study, blanching in water without additives is the most appropriate method for preserving physiologically active substances and nutrients in beetroots and inhibiting microbial growth.
        4,000원
        85.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        대파(Allium fistulosum) 정식부터 수확기까지 성페로몬을 이용하여 재배지에 발생한 파좀나방(Acrolepiopsis sapporensis)을 모니터링하였 다. 이 시기에 발생한 파좀나방은 월동세대 이후 6월 초와 7월 말에 각각 발생 최성기를 보였다. 그러나 발생량은 연도와 재배 환경에 따라 다르게 나타났다. 파좀나방을 효과적으로 방제하기 위한 미생물제제로서 Bacillus thuringiensis 균주를 스크리닝하였고, 이들 가운데 B. thuringiensis kurstaki (BtK)가 선발되었다. 선발된 BtK의 살충력을 높이기 위해 다른 곤충병원세균인 Photorhabdus temperata temperata (Ptt) 세균 배양액 추 출물을 추가하였다. 이들 두 세균을 혼합한 ‘비티플러스’는 BtK 단독 보다 현격하게 높은 살충력을 나타냈다. 이러한 살충력 제고 원인은 Ptt 추 출물에 포함된 대사물질에 의해 기인되었다. 이들 대사물질은 파좀나방의 세포성 및 체액성 면역반응을 억제하여 BtK의 살충력을 제고시킨 것으 로 나타났다. 이상의 결과는 국내 대파 재배지에서 파좀나방이 지속적으로 발생하며, 이 해충에 의한 경제적 피해를 줄이기 위한 비티플러스의 효 과적 방제 가능성을 제시하였다.
        4,000원
        86.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In addition to its effectiveness in resolving apical periodontitis, regenerative endodontic treatment (RET) has advantages of inducing root maturation and restoring innate immunity or sensory function through revascularization. However, its adoption in mature teeth in adults has been scarce due to limited stem cell sources and constricted apical size. In recent years, there have been instances of studies performing RET in mature permanent teeth. The present case report describes the treatment of apical periodontitis in a previously treated mature permanent tooth using RET with a 3-year follow up. In the present case, a 34-year-old female patient presented with previously treated maxillary lateral incisor with a large radiolucency. After removal of previous gutta percha within the root canal, bleeding was induced by passing hand file beyond root apex and calcium hydroxide was applied over the blood clot. During the 9-month follow-up, a reduction in periapical radiolucency was observed. Subsequently, after removing calcium hydroxide, apical bleeding was induced again and mineral trioxide silicate was placed up to 3mm beneath cemento-enamel junction, above the blood clot. The tooth was later restored with glass-ionomer cement and composite resin. After 3 years, the tooth was asymptomatic and radiographic evaluations showed complete resolution of periapical radiolucency with presence of normal lamina dura and periodontal ligament space. In conclusion, modified RET with long-term calcium hydroxide application is a potentially viable treatment option for previously treated mature permanent teeth with apical periodontitis. However, further clinical studies with larger number of cases are recommended to verify its effect.
        4,000원
        87.
        2023.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to analyze microstructural changes and evaluate the mechanical properties of TWIP steel subjected to variations in heat treatment, in order to identify optimal process conditions for enhancing the performance of TWIP steel. For this purpose, a homogenization heat treatment was conducted at 1,200 °C for 2 h, followed by hot rolling at temperature exceeding 1,100 °C and cold rolling. Annealing heat treatment is achieved using a muffle furnace in the range of 600 °C to 1,000 °C. The microstructure characterization was performed with an optical microscope and X-ray diffraction. Mechanical properties are evaluated using micro Vickers hardness, tensile test, and ECO index (UTS × Elongation). The specimens annealed at 900 °C and 1,000 °C experienced a significant decrease in hardness and strength due to decarburization. Consequently, the decarburization phenomenon is closely related to the heat treatment process and mechanical properties of TWIP steel, and the effect of the microstructure change during annealing heat treatment.
        4,000원
        1 2 3 4 5