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        검색결과 350

        1.
        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
        2.
        2023.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To develop a functional probiotic that inhibits gingipain, a major virulence factor of Porphyromonas gingivlais (P. gingivalis), we screened over 30 probiotic strains for their ability to inhibit gingipian activity. We investigated the inhibition of expression of gingipain genes kgp, rgpA, and rgpB as well as gingipain activity, using freeze dried cell-free supernatants of Weisiella cibaria SPM402 (WC402) and Lactobacillus paracasei SMP412 (LP412), both of which demonstrated antibacterial activity against P. gingivalis. Thus, it was verified that kgp expression was reduced by approximately 0.71±0.02 folds and rgpB expression was reduced by approximately 0.71±0.14 folds at a concentration of WC402 10 mg/mL. Meanwhile, at the same concentration of 10 mg/mL of LP412, kgp expression was reduced by approximately 0.19±0.08 folds, rgpA expression was reduced by approximately 0.09±0.02 folds, and rgpB expression was reduced by approximately 0.24±0.03 folds. At a concentration of 10 mg/mL, Kgp activity was inhibited by approximately 78.65±3.58% (cell associated gingipain, CAG), 82.45±1.22% (cell-free gingipain, CFG) by WC402 and 80.71±2.11% (CAG), and 85.81±0.05% (CFG) by LP412 respectively. Rgp activity was also effectively inhibited by approximately 78.6±1.01% (CAG), 86.78±0.47% (CFG) and 82.93±1.26% (CAG), 88.81±0.36% (CFG) by WC402 and LP412 respectively. Based on these results, W. cibaria SPM402 and L. paracasei SPM412 can be regarded as functional probiotics with the ability to inhibit gingipain activity and exhibit antibacterial effects against P. gingivalis.
        4,000원
        3.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        호장은 마디풀과에 속하는 다년초로 우리나라를 포함한 동아시아에서 잘 자생한다. 호장근은 호장의 뿌리로 항염증과 진경제로 사용되어 왔으며 유효성분으로 emodin을 포함하고 있다. 피부의 표피는 자극, 해로운 물질을 차단하고 수분 증발을 방지함으로써 체내를 보호하는 중요한 역할을 한다. 본 연구에 서는 호장근과 그 유효성분인 emodin이 피부 장벽과 보습능에 미치는 영향에 대해 평가하고자 하였다. 먼 저 호장근은 ABTS+ radicals을 우수하게 제거함으로써 항산화 효능이 뛰어남을 확인하였다. 다음으로, 실 시간 중합연쇄효소반응을 통해 각질형성세포의 분화에 중요한 역할을 하는 filaggrin의 유전자 발현을 비교 한 결과, 호장근과 emodin에 의해 농도-의존적으로 filaggrin mRNA 발현이 증가하였다. 또한, 호장근과 emodin은 히알루론산 합성에 중요한 역할을 하는 HAS-2 mRNA 발현을 유의하게 증가시키는 것으로 나 타났다. 종합적으로, emodin을 유효성분으로 포함하는 호장근은 피부 장벽 강화와 보습능 증강을 위한 기 능성 화장품 소재로서 활용될 수 있을 것으로 기대된다.
        4,300원
        5.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 군(軍) 교육훈련에 대한 효율성과 효과성을 제고하기 위해 공군 교육사령부 산하 특기학교인 군수2학교를 수료한 교육생들을 대상 으로 이들의 학습만족도에 영향을 미치는 변수들을 규명하였다. 구체적 으로, 학업적 자기효능감과 교육만족도가 학습만족도에 미치는 영향과 이들의 관계에서 부정적 평가에 대한 두려움의 조절효과를 실증분석했 다. 분석결과 첫째, 학업적 자기효능감의 하위변수인 자기조절 효능감, 자신감은 학습만족도에 유의미한 정(+)의 영향을 미치는 것으로 나타났 다. 둘째, 교육만족도는 학습만족도에 유의미한 정(+)의 영향을 미치는 것으로 나타났다. 셋째, 교육만족도가 학습만족도에 미치는 영향에서 부 정적 평가에 대한 두려움의 조절효과가 검증되었다. 본 연구는 군 특기 학교 수료생의 학습만족도를 실증적으로 연구한 소수의 연구라는 점에서 관련 연구의 이론적 축적에 기여하고 있다. 나아가, 특기학교 교육의 효 율성·효과성을 제고할 수 있는 실무적 시사점을 제시함에 의의가 있다.
        9,500원
        6.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        편백나무(Chamaecyparis obtusa)는 측백나무과에 속하며 우리나라 남쪽 지역에서 주로 잘 자 생한다. 편백나무의 목재는 재질이 우수하여 가구로서의 활용이 높으며 남은 목재, 가지, 잎은 정유 추출에 사용되고 있다. 편백 정유는 항염, 향균, 탈취, 진정 효능이 탁월한 것으로 알려져 있다. 본 연구는 이러한 편백나무의 잎에서 추출한 오일이 주름 개선, 피부 장벽 및 보습능에 미치는 영향을 평가하고자 하였다. 먼 저, DPPH assay와 ABTS assay를 통해 항산화 활성을 평가한 결과, 편백 오일은 두 가지 라디칼을 농도 의존적으로 유의하게 소거하였다. 그리고 주름 생성 억제 효능 평가를 위해 elastase 활성을 측정한 결과, 편백 오일은 elastase 활성을 직접적으로 억제시킴을 확인하였다. 다음으로는 real-time PCR을 통해 유전 자 발현을 확인한 결과, 편백 오일은 인간섬유아세포에서 MMP-1 유전자 발현을 유의하게 감소시켰다. 또 한, 편백 오일에 의해 각질형성세포에서 filaggrin과 HAS-2 유전자 발현이 유의하게 증가함을 확인하였다. 이러한 결과를 종합해보면, 편백 오일은 주름 개선과 피부 장벽 및 보습능 강화에 도움을 주어 항노화 화장 품의 기능성 원료로서 활용될 수 있을 것으로 기대된다.
        4,500원
        7.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Seaweed-derived foods have long been popular in Korea because of their high content of nutrients that are beneficial to the human body. Recently, Korean seaweeds have been used as raw materials to produce new natural products with health benefits. Herein, we compared the antioxidant activity of 16 Korean seaweed extracts to explore their potential utility as health foods. The total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of seaweed extracts were determined. We also investigated their ability to protect human diploid fibroblast (HDF) cells against hydrogen peroxide. The results showed that seaweed extracts at a concentration of 100 g/mL did not cause any cell toxicity. Sargassum thunbergii (Jichung-i) had the highest TPC and radical scavenging effects, followed by Porphyra tenera (Gim), Silvetia siliquosa (Tteumbugi), and Sargassum fusiforme (Tot). Hydrogen peroxide increased the production of intracellular reactive oxygen species, while P. tenera (Gim), Saccharina japonica (Dasima), and S. thunbergii (Jichung-i) extracts significantly decreased it. The effect was highest in the S. thunbergii (Jichung-i)-treated HDF cells. These findings indicate that S. thunbergii (Jichung-i) shows promise as a potential antioxidant raw material.
        4,000원
        8.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study sought to conduct a fundamental investigation in order to test and evaluate the thermal performance of an aluminum stick curtain wall system. In terms of the thermal performance index, the infiltration rate of air tightness, thermal transmittance of the heat insulation property and temperature difference ratio of condensation resistance were experimentally measured. The research process can be divided into three parts. First of all, a database for the test report of the curtain wall was compiled and existing design criteria with respect to the evaluation method and standard of transparent building components such as curtain wall, window and door were analyzed to produce the specimens. Secondly, four different types of curtain wall specimens were created through investigating the curtain wall database. Thirdly, standard tests of thermal performance were carried out for airtightness, thermal performance and condensation resistance. As a result, the curtain wall specimens with low-e triple glazing covered by an aluminum capture system showed high thermal performance compared to other curtain wall specimens including low-e triple glazing with a 4-sided structural sealant glazing system. Air tightness of all types of curtain wall specimens satisfied level 1 standard for air tightness. It was found that a curtain wall which consists of a one track frame has difficulties meeting the residential standard of thermal performance with regard to thermal transmittance and condensation resistance.
        4,300원
        9.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oral squamous cell carcinoma (OSCC) is the most common type of head and neck cancer and is associated with high recurrence, poor treatment, and low survival rates. Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that regulates the response to hypoxia, a major factor in the tumor microenvironment that affects tumor development and progression in various cancer types. However, microRNA (miRNA) sequence analysis revealed that only a few miRNAs targeting HIF-1α had been discovered. In the present study, we investigated HIF-1α expression in OSCC and the effect of HIF-1α-targeting miRNAs on the progression and metastatic potential of OSCC. We analyzed public databases to explore which miRNAs target HIF-1α expression. In addition, the expression of proteins involved in the cell cycle, proliferation, and apoptosis in HSC-2 cells was analyzed after miRNA-126 mimic treatment. Furthermore, to investigate the effect of miRNA-126 on the proliferation and invasion ability of OSCC cells, 5-ethynyl-2′-deoxyuridine and Transwell assays were performed. The activities of MMP-2 and MMP-9 were evaluated via gelatin zymography. Our results showed that miRNA-126, which targets HIF-1α, enhances OSCC cell proliferation by regulating the cell cycle and reinforces the cell mobility of OSCC via HIF-1α expression. These findings suggest that miRNA-126 may be a novel marker for OSCC treatment and the development of new tools for patients with OSCC.
        4,200원
        10.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the quality characteristics and antioxidant effects of rice cookies containing different percentage of freeze-dried plum powder (3%, 5%, 6%, and 12%). The density of the dough and the thickness of the rice cookies from the control group and the additive group were not significantly different. The pH value of the dough, its moisture content and spread factor, as well as the Hunter’s L and b values of the rice cookies significantly decreased as the amount of dried plum powder added increased. However, the sweetness, hardness, thickness, Hunter’s a value, total polyphenol, total flavonoid and anthocyanin contents, DPPH and ABTS free radials scavenging activity, and ferric reducing antioxidant power of the rice cookies significantly increased as the amount of dried plum powder added increased. Overall, the results of this study showed that adding dried plum power enhanced the antioxidant activities and quality characteristics of rice cookies.
        4,600원
        11.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Quality standards of activated carbon for gas-phase applications have been deleted from the Korean national standard list since 2007, and the iodine adsorption test is the only measure currently used for quality assurance. This study was performed to propose a suitable test method and a quality standard for gas-phase activated carbon. The "1/2 saturated vapor adsorption" test has been developed as a simple and convenient method to determine the adsorption capacity of activated carbon. In this study, the developed test method was evaluated using model VOCs including toluene, methyl ethyl ketone (MEK), and ethyl acetate (EA). A virgin activated carbon revealed adsorption capacities of 344mg/g, 322mg/g, and 328mg/g for toluene, EA, and MEK, respectively, and the adsorption capacity for a mixture of the three VOCs was 334 mg/g. When a regenerated activated carbon was applied, the adsorption capacities dramatically decreased to 62 mg/g, 52 mg/g, and 61 mg/ g for toluene, EA, and MEK, respectively. In addition, the 1/2 solvent vapor adsorption tests using 13 different specimens of activated carbon showed that their capacities were closely related to the iodine adsorption numbers, and this study suggested the adsorption capacity of 300 mg/g as a new quality standard. The novel test method and its standard may help to guarantee the quality of gas-phase activated carbon used for VOCs abatement processes.
        4,000원
        12.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        코로나19라는 전 지구적 위기 발생 이후 지속가능발전목표(SDGs) 관 련 논의에 새로운 접근이 요구되었다. 특히 재원 발굴, 정책 효과성 문제 해결을 위한 개발 파트너십 확대 필요성이 논의되면서 인적·물적 자원, 기술을 보유한 기업이 주요 행위자로 대두되었지만 SDGs 이행 과정에서 기업의 역할에 대한 학문적 논의는 부족하다. 본 연구는 개발 파트너십 의 개념과 등장 배경, 기업이 주목받는 원인을 소개하고, 기업의 사회적 책임(CSR)을 국제개발협력 관점에서 분석하여 개발파트너십 확대에 관한 이론적 근거를 밝히고자 하였다. 주주 중심론, 이해관계자 중심론, 기업 시민론적 관점을 통합한 이론적 분석틀을 토대로 기업의 ESG와 SDGs의 연계를 제안하여 개발파트너십 확대에 관한 정책적 함의를 도출하였다. 기업이 개발 파트너십에 능동적으로 참여하기 위해서는 SDGs 이행참여 를 통한 ESG 성과 향상이 ESG 투자 확대를 유발한다는 주주 중심론, 긍정적인 기업 이미지를 창출한다는 이해관계자 중심론, 기업의 ESG 목 표와 SDGs의 연계가 국제규범과의 정합도를 향상시킨다는 기업시민론적 논의를 통합하여 기업에게 제공할 유인책을 고려할 필요가 있다.
        8,900원
        13.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we analyzed the antifungal activities of five essential oils (clove, rosemary, thyme, basil, and oregano) against three fungi (Penicillium oxalicum, Penicillium commune, and Cladosporium cladosporioides) isolated from farm-type fermented meat products Though their antifungal activities differed for each fungus, thyme had the greatest effect. Notably, C. cladosporioides showed the highest sensitivity to essential oils, and growth inhibitory effects were greater than for the other two strains. Additionally, ABTS, DPPH, and FRAP analysis confirmed that the five essential oils studied had antioxidant activity. ABTS analysis showed that clove (75%) and oregano (75%) oils had the highest antioxidant activities (both 93.7%). DPPH analysis showed that clove (75%) and rosemary (75%) oils had significantly greater antioxidant activities (both 93.8%) than thyme, basil, or oregano oils. FRAP results indicated that clove and basil oils were the strongest reductants. Comprehensive comparative analysis indicated that clove oil had more antioxidant activity than the other four essential oils. Overall, the study shows that the excellent antifungal properties of clove oil could be harnessed to produce safe fermented meat products by preventing rancidity and mold contamination.
        4,000원
        14.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 초등학교 남자 축구선수들을 대상으로 12주간 근파워 및 민첩성 트레이닝이 체 력요인과 등속성근기능에 미치는 효과를 규명하고자 하였다. 이를 위해 초등학교 남자 축구선수 12명을 대 상으로 근파워와 민첩성 트레이닝 프로그램 6개를 구성하여 12주간 주 3회 실시하였다. 근파워, 민첩성 트 레이닝 전과 후 운동에 대한 체력요인들을 측정하여 분석한 결과는 다음과 같다. 첫째, 근파워의 제자리멀 리뛰기에서는 유의한 차이가 나타났다(p<.001). 둘째, 근파워의 제자리높이뛰기에서 유의한 차이가 나타났 다(p<.05). 셋째, 민첩성의 사이드스텝에서 유의한 차이가 나타났다(p<.01). 이상의 결과로 12주간의 근파 워 민첩성 트레이닝은 초등학교 남자 축구선수들의 순발력과 민첩성 향상에 긍정적 효과를 기대할 수 있으 며, 상해 예방과 경기력 향상을 위한 트레이닝 기초 자료를 제공할 수 있을 것으로 판단된다.
        4,000원
        15.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 비건 인증(Vegan) 화장품 원료 7종 혼합추출물의 항산화능 및 미백효과를 확인 하였다. 라디컬 소거능으로서 DPPH, ABTS, FRAP 실험, 항산화 물질 측정으로서 폴리페놀과 플라보노이 드 함량 측정을 실시하였다. DPPH 실험에서는 105.74 mg ascorbic acid / g의 항산화능을 나타내었으며, ABTS 실험에서는 85.31 mg ascorbic acid / g의 항산화능을 나타내었다. FRAP에서는 7종 혼합추출물의 1 mg이 ascorbic acid 198.01±5.50 μg의 환원력을 보였다. 폴리페놀 함량은 30.19±0.75 mg/g으로 나타 났으며, 플라보노이드 함량은 9.12±0.36 mg/g으로 나타났다. 한편 세포실험에서는 세포 독성과 미백활성 을 알아보았다. 세포독성의 경우 20% 이하의 세포 독성을 보였으며, 100 μg/mL 농도에서 34.70±2.97% 의 멜라닌 생성 억제능을 보여 7종 혼합추출물의 기능성 화장품 원료로서의 가능성을 확인하였다.
        4,000원
        16.
        2021.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Yogurt is mostly consumed dairy food and considered as a nutritious food because of its probiotics such as lactic acid bacteria (LAB). LABs are known to possess antioxidant, anticarcinogenic and antimicrobial effects. Corni fructus has healthy and pharmacological effects such as the inhibition of apidogenesis and angiopoiesis. Thus, the purpose of this study was to evaluate quality characteristics and antioxidant activity of yogurt supplemented with water and ethanol extracts of corni fructus. Yogurt was manufactured with addition of 0.1%-0.2% (w/v) water or ethanol corni fructus extracts, respectively. For quality characteristics, pH, chromaticity, viscosity and syneresis were determined during refrigeration storage (1, 7, 14, and 21 day). For antioxidant activities, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities were examined during storage. The pH showed no significant difference between groups but showed decreasing pattern for all groups during storage period. In chromaticity, redness increased, and lightness decreased as the amount of corni furctus extracts increases. Yogurt with corni furctus ethanol extracts showed more color changes than yogurt with corni furctus water extracts. Viscosity increased in corni furctus extract added groups, compared to control. Syneresis was approximately 2-fold higher in corni fructus extract added groups, while there were no significant changes between control and extract added groups. Both DPPH and ABTS radical scavenging activities were significantly higher than control group in corni fructus extract added groups, compared to control. In conclusion, addition of corni fructus extracts in yogurt improved quality characteristics during storage and antioxidant properties.
        4,000원
        17.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        상⋅하수도 관로 시설은 대표적인 국가기반 시설물로서 국민생활에 있어서 매우 중요한 라이프 라인이다. 지진으로 인한 관로시설의 손상은 급수의 차단을 유발하여 심각한 피해를 초래할 가능성이 매우 크다. 그러므로 상⋅하수도 관로 시설은 지진으로부터 반듯이 안전하게 보호되어야 할 필요가 있다. 지진 및 지반침하로 인한 설계변위를 초과하는 상대변위는 구조물과 연결되는 배관의 이음부에서 손상을 발생시킨다. 벨로우즈형 신축이음관은 온도차에 의한 배관의 팽창 및 변형을 흡수하고 기계진동에 의한 배관의 손상을 막기 위한 장치이다. 본 연구에서는 매설된 상⋅하수도 관로를 보호하고자 지진변위와 지반침하 대응을 목적으로 벨로우즈를 적용하였다. 적층형 하이드로포밍 메탈 벨로우즈는 기존의 벨로우즈와 달리 지진과 같은 저주 기피로하중에 대한 내구성이 우수하다. 따라서 3ply 벨로우즈형 신축이음관을 대상으로 반복가력 굽힘시험을 수행하고 지진안전성과 내침하성능을 평가하였다. 그 결과, 3ply 벨로우즈형 신축이음관은 8.8°이상의 횡방향 변형각에 대응할 수 있는 것으로 나타났다.
        4,000원
        20.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the demand for the monitoring of VOCs increases, various unpowered colorimetric sensors are being developed, but the performance evaluation method of the developed sensors has not been systematically established. In this study, the device, experimental process, and data calculation methods for the performance evaluation of the colorimetric sensors were proposed. An aluminum chamber (70W× 128 L × 40 mm H) was designed to expose the sensor to a constant concentration of VOCs. In addition, an experimental apparatus was devised to evaluate the effect of environmental factors (temperature and humidity) affecting the ability of the sensor to detect VOCs. To calculate the color change value of the sensor corresponding to the concentration of VOCs, the ‘peak wavelength method’ that analyzes the wavelength of the highest intensity for high-concentration VOCs and the ‘spectral centroid method’ using a weighted arithmetic average for low-concentration VOCs were used. As a result of evaluating the ability of the colorimetric sensor to detect VOCs, which was made of polydimethylsiloxane (PMDS) by the method proposed in this study, the wavelength change values (bandgap shift) of the sensor for 1,000 ppm of benzene, toluene, oxylene, and acetone were 0.898 nm, 2.304 nm, 5.775 nm, and 0.249 nm, respectively. The precision was calculated by repeatedly measuring the sensing ability of the sensor 5 times for each type of VOCs. The precision of the sensor responses to benzene, toluene, o-xylene, and acetone were 15.23%, 7.84%, 4.14%, and 30.00% RSD, respectively. The method proposed in this study can be used to evaluate the performance of various types of VOCs colorimetric sensors.
        4,200원
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