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        검색결과 3,260

        42.
        2023.11 구독 인증기관·개인회원 무료
        Understanding the dispersion of xenon isotopes following a nuclear test is critical for global security and falls within the remit of both the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and the International Noble Gas Experiment (INGE). This paper aims to show if it is possible to discriminate the source of xenon releases based on the atmospheric dispersion of xenon isotopes using HYSPLIT. Using ORIGEN and SERPENT simulations, four released scenarios are defined with four different fractionation times (i.e., 1 hour, 1 day, 10 days, and 30 days) after a 1kt TNT equivalent 235U explosion event. These time-delayed release scenarios were selected to certify the possibility of mis-determining xenon release source. We use the Lagrangian dispersion model for atmospheric dispersion to predict the concentration distribution of xenon isotopes under each scenario. The model allows us to better understand how these isotopes would distribute over time and space, offering valuable data for real-world detection efforts. To our knowledge, there have been no researches on the analysis of xenon isotopic ratios considering atmospheric dispersion. In this work, we focused on the atmospheric dispersion using HYSPLIT to characterize the xenon isotopic ratios from nuclear tests. In addition, we compared the xenon isotopic ratios obtained from the atmospheric dispersion with those from ORIGEN calculations, which would be helpful to discriminate the source of the xenon releases.
        43.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hesperetin은 Hesperidin에서 유도되는 강한 항산화 기능의 플라보노이드 비당체이다. 본 연구 에서는 Hesperetin과 이의 Cyclodextrin 포접 복합체에 대하여 항산화, 항염증 및 항균 활성을 비교하였다. Hesperetin은 Hesperidin에 효소처리하여 제조되었으며, Hesperetin/Cyclodextrin 포접체는 용매 증류법에 의해 β-Cyclodextrin 및 Hydroxypropyl-β-Cyclodextrin을 사용하여 제조되었다. Hesperetin에 비해 Hesperetin/Hydroxypropyl-β-Cyclodextrin 포접체의 용해도는 93.5배 증가하였고, Hesperetin/β -Cyclodextrin 포접체의 용해도는 22.5배 증가하였다. 항산화 분석에서 Hydroxypropyl-β-Cyclodextrin 포접체는 Hesperetin과 유사한 라디칼 소거 활성능을 보인 반면, β-Cyclodextrin 포접체는 Hesperetin 보 다 약간 낮은 활성을 나타내었다. RAW 264.7 세포에 대한 세포독성은 Hydroxypropyl-β-Cyclodextrin 포접체, β-Cyclodextrin 포접체, Hesperetin의 순으로 세포독성이 낮았다. Hesperetin과 Cyclodextrin 포 접체는 모두 세포내 산화질소(NO), 종양괴사인자-α(TNF-α) 및 인터루킨-6(IL-6)과 같은 염증 매개체 를 감소시켰다. Hesperetin 및 Hydroxypropyl-β-Cyclodextrin 포접체는 상대적으로 β-Cyclodextrin 포접체 보다 더 효과적이었다. 피부 유해성 세균인 황색 포도상구균과 녹농균에 대해 억제 효과를 시험한 결과, 황색 포도상구균에 대해서는 Hesperetin = Hydroxypropyl-β-Cyclodextrin 포접체 > β -Cyclodextrin 포접체의 순서로 항균 효과를 나타내었으나, 녹농균에 대해서는 뚜렷한 억제효과를 나타내 지 않았다. 결론적으로, Hesperidin의 비당체 형태인 Hesperetin과 이의 Cyclodextrin 포접체는 다양한 생 물학적 활성을 보여주었으며, 용해도가 높은 Hydroxypropyl-β-Cyclodextrin 포접체가 β-Cyclodextrin 포접체에 비해 상대적으로 더 높은 활성을 나타내었다.
        4,500원
        44.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 대도시에서 미세먼지 없는 학교 부지를 찾는 Model Eliciting Activity (이하 MEA) 활동을 통해 고 등학교 학생들의 문제 해결 특성을 조사하기 위한 것이다. 5차시로 개발된 MEA 활동에 79명의 고등학교 2학년 학생 들이 참여 하였으며, MEA 활동지를 주요 데이터로 수집하였다. 학생들이 작성한 활동지의 개방형 질문에 대한 답을 기반으로 학생들의 문제 해결 모델을 귀납적 및 질적 방법으로 분석하였다. 먼저 학생들이 다른 데이터보다 어떤 데이 터를 우선적으로 사용했는지 순서를 분석한 후 주어진 데이터 세트를 어떻게 상호 연결하여 순서를 결정하는지 분석하 였다. 분석결과 학생들은 미세먼지 배출량이 많은 곳을 기피하기 위해 미세먼지 배출농도, 산업단지 분포 등 미세먼지 와 직접적으로 관련된 데이터를 먼저 활용하는 경향이 있음을 알 수 있었다. 흥미롭게도 MEA 활동에서 고등학생의 문 제 해결 특성은 매우 다양하여 76명의 학생이 총 61가지 유형의 문제 해결 모델을 제작한 것으로 나타났다. 문제를 해 결하기 위해 동일한 순서의 데이터를 사용하는 학생의 최대 수는 6명으로 학생들의 문제 해결 방법은 매우 다양함을 보여준다. 그러나 공통적으로 미세먼지 농도가 높은 곳을 제외하는 방법으로 미세먼지 배출과 직접적으로 관련된 데이 터를 먼저 선택하는 특성을 보였다.
        4,200원
        45.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the consumption of corn increases, the production of by-products is also increasing. In this study, functional substances and antioxidant activities of corn by-products were investigated to determine their applicability as functional materials. Total polyphenol, flavonoid contents, and ABTS antioxidant activity were the highest in leaves. The total phenolic acid content was the highest in cobs; p-coumaric and ferulic acid were the main components. Phytosterol content in leaves and stems was high at 64 and 50 days after sowing, 261.4 and 274.7 mg/100 g, respectively. β-sitosterol of the leaves and stems was the highest, 149.2 and 138.7 mg/100 g. The total phytosterol content of grains and by-products harvested 106 days after sowing was in the order of: corn silk, husk, grain, leaf, stem, and cob. Among the phytosterols, β-sitosterol was the highest, followed by stigmasterol and campesterol, and the composition was different depending on part. The total phytosterol content was the highest in husk and corn silk, but the stems and leaves, which account for 50% of the total corn biomass, also contained high phytosterol content. Therefore, corn leaves and stems are expected to be used as functional raw materials for the development of functional materials in the future.
        4,000원
        46.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A mono-type glycerine fatty acid ester compound was chemically synthesized using medium-chain fatty acids with antibacterial activity, and the physicochemical quality and antibacterial activity of the synthesized glycerine medium-chain fatty acid ester compound were measured. At a reaction molar ratio of MCT(medium chain triglyceride) to glycerine of 1:2.5, 48.15% mono ester was produced. The physicochemical analysis of the synthesized glycerine fatty acid ester compound showed an acid content of 0.38~0.60%, which tended to increase slightly as the glycerine molar ratio increased. The saponification value decreased as the synthesized molar ratio of glycerine increased from 218 to 284. The number of bacteria was measured to confirm the degree of antibacterial activity of glycerine medium-chain fatty acid esters against food poisoning bacteria, Bacillus cereus and Salmonella typhi. The number of bacteria significantly decreased as the MCT:glycerine molar ratio increased. In particular, the antibacterial effect between the treatment groups was the highest when at an MCT:glycerine molar ratio of 1:2.5.
        4,000원
        49.
        2023.10 구독 인증기관·개인회원 무료
        Protaetia brevitarsis seulensis larvae from industrial insects are traditionally recognized as functional health foods in South Korea. We evaluated the immuno-modulatory effects of feeding beneficial microorganism (Bacillus velezensis TJS119) to P. brevitarsis larvae as a dietary source. In this study, we investigated the immune-enhancing activities of P. brevitarsis larvae hot-water extract (PLW) and PLW after treatment with B. velezensis TJS119 (PLWB) using the RAW 264.7 macrophage cell line. We examined the effects of PLWB on cell proliferation, cytokine production, and nitric oxide production in RAW264.7 cells. PLWB showed no cytotoxicity at concentrations ranging from 7.8 to 1,000 μg/mL in RAW264.7 cells. Treatment with PLWB increased the production of nitric oxide and pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β)] at doses of 62.5 to 1,000 μ g/mL in RAW264.7 cells. As a result, PLWB exhibited a stronger immune-enhancing effect compared to PLW. In conclusion, the results of this study offer experimental evidence to support the potential utilization of PLWB as an immunity-enhancing nutraceutical ingredient.
        50.
        2023.10 구독 인증기관·개인회원 무료
        The development of biochemical pesticides to replace existing chemical pesticides and the search for new substances with potential insecticidal ability are continuously required. The purpose of this study is to control myzus persicae with pyrethrum biochemical pesticide containing of high concentration of pyrethrin as an active ingredient. Pyrethrum dried powder was extracted with 95% ethanol for different periods of time and it was confirmed that the pyrethrin content increased as the extraction period increased and the extraction conditions for 20 days had the highest yield with 0.2% pyrethrin. We produced a prototype containing 0.13% pyrethrin content (pyrethrin II: 0.06%, pyrethrin I: 0.06%). and in 200 fold dilute spray condition. It showed a 77.2% corrected mortality against myzus persicae which is comparable to chemical pesticide. We are continuously researching to reduce the decomposition of active ingredients and look for additives to increase the insecticidal activity.
        51.
        2023.10 구독 인증기관·개인회원 무료
        배에 피해를 주는 해충 중 하나인 주경배나무이는 2~3월 경 배나무의 거친껍질 밑에서 겨울을 난 후 나무 위로 올라가 산란하는데, 이 때를 월동 후 방제적기로 한다. 월동 후 방제에는 주로 기계유유제를 사용하고 있으나 저온피해가 자주 발생하거나 나무의 세력이 약한 농가는 방제 후에 언피해 발생을 우려하여 살충제를 살포하거 나 방제를 하지 않는다. 월동 후 발생밀도를 조절하지 못할 경우 생육기에 피해가 커지기 때문에 기계유유제를 대체할 수 있는 약제를 확인하고자 하였다. 또한 2023년 2월 EU 수출 대상 농가에는 아바멕틴 성분의 살충제 사용을 제한하는 규제가 발표되어 생육기에 발생하는 주경배나무이 여름형 성충에도 아바멕틴 성분을 대신하 여 적용 가능한 약제를 선정하고자 하였다. 주경배나무이 대상 등록 약제 중 아바멕틴, 아세타미프리드, 이미다 클로프리드, 설폭사플로르를 시험약제로 선정하였으며, 약제검정 결과 겨울형 성충에는 아세타미프리드 > 아 바멕틴 > 이미다클로프리드 > 설폭사플로르, 여름형 성충에는 아바멕틴 > 설폭사플로르 > 이미다클로프리드 > 아세타미프리드 순으로 살충률이 확인되었다. 살충력 추가 검정 및 여름형과 겨울형 성충의 충체 특성을 비교 한 후 기계유유제 및 아바멕틴 성분 대신 사용이 가능한 약제 성분을 권장할 수 있을 것으로 사료 된다.
        52.
        2023.10 구독 인증기관·개인회원 무료
        The beet armyworm, Spodoptera exigua, is one of the worldwide distributed agricultural pest insects and has been known to show high resistance to conventional chemical insecticides. Since it has been reported that secondary metabolites from actinomycetes show insecticidal activities against various insect pests, actinomycetes could be a potential source of insecticidal compounds. In this study, culture extracts of Streptomyces strains were tested for their insecticidal activity against Spodoptera exigua. Among them, culture extracts of IMBL-0003 strain which was identified as Streptomyces celluloflavus showed a high insecticidal activity (more than 90% mortality). These results suggested that secondary metabolites of this isolate could have potentials to be a efficient eco-friendly pesticide for controling Spodoptera exigua.
        53.
        2023.10 구독 인증기관·개인회원 무료
        최근 벚나무에 벚나무깍지벌레에 의한 피해가 증가하여 친환경적인 방제제로서 곤충병원성 곰팡이인 Beauveria bassiana ARP14를 검증하였다. 경북 안동시 안동대학교 캠퍼스 내 벚나무에서 벚나무깍지벌레의 감염율을 조사하고, 벚나무의 연령을 추정하여 상관관계를 분석하였다. 곤충병원성 곰팡이의 살충력을 확인하 기 위해 약충의 이동성이 가장 활발한 4월 말부터 5월 중순까지 벚나무깍지벌레에 감염된 가지를 채집하여 23°C 의 항온기에 보관하면서 두 가지 곤충병원성 곰팡이(ARP14, AAD16)를 살포하여 살충제(스피로테트라맛 액상 수화제) 처리구와 살충률을 비교하였다. 그 결과 대조구(물처리)보다 곤충병원성 곰팡이를 살포한 가지에서 약충의 개체 수가 더 감소하였으나, 살충제를 처리한 가지에서 보다는 약충의 수가 많았다. 따라서 가로수로 많이 식재된 벚나무 해충 방제시 일어날 수 있는 사람에 대한 피해를 최소화할 수 있는 친환경 방제제로서 곤충병 원성 곰팡이를 사용할 수 있을 것이다.
        54.
        2023.10 구독 인증기관·개인회원 무료
        Stilbene-based fluorescent brighteners (FB) have been shown to enhance insecticidal activities of entomopathogenic viruses but little is known its effect on entomopathogenic bacteria. We investigated the effect of two FBs (FB 28 and FB 71) on the insecticidal activity of B. thuringiensis var. kurstaki (Btk) as well as the Lymantria dispar multiple nuclear polyhedrosis virus (LdMNPV) in Lymantria dispar asiatica. FB 28 increased the mortality at the combination with low concentration (1.6×102 IU/ml) of Btk, but FB 71 slightly reduced the mortality with middle and high concentrations (1.6×103 and 1.6×104 IU/ml) of Btk in comparison to Btk alone. Both FB 28 and FB 71 increased mortality in combination with LdMNPV at all concentrations (3×102, 3×104, and 3×106 POBs/ml) compared to LdMNPV alone. Our findings suggest that FBs enhanced pathogenic activities but depend on chemical nature of FBs.
        55.
        2023.10 구독 인증기관·개인회원 무료
        Due to the concerns over their environmental and health impacts, there have been attempts for shift towards biorational pesticides from synthetic pesticides. Among them, plant essential oils have emerged as promising active ingredients. Due to the complex interactions among their constituents, the bioactivities of essential oils can vary depending on the compositions, which often undermine their stability in efficacy. Here, we present a model-based optimization approach to develop reliable rosemary oil-based biorational pesticide, against two-spotted spider mites, Tetranychus urticae Koch. The ecotoxicity against Daphnia magna and foliar phytotoxicity against Phaseolus vulgaris were also evaluated. Our quadratic models accurately predicted miticidal activity, ecotoxicity, and phytotoxicity. We aimed to maximize, minimize, and minimize these parameters, respectively. We employed seven multi-objective evolutionary algorithms in Matlab. Among them, the nondominated sorting genetic algorithm II with adaptive rotation based simulated binary crossover (NSGA-II-ARSBX) performed best. We experimentally determined the thresholds for miticidal activity and phytotoxicity, based on the current approval process for agricultural pesticide products in Korea. After applying the thresholds, we validated the obtained viable solutions. Our study offers a novel framework to enhance the reliable and responsible use of essential oils as biorational pesticides.
        56.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Choosing to perform squats on an unstable surface potentially offers advantages surpassing those of their stable counterpart. Objectives: The purpose of this study was to compare muscle activation during squats on stable and unstable surfaces and investigate the relationship among thigh muscles. Design: Observational study. Methods: Nineteen adults participated in this study. The stable surface consisted of a flat floor. The unstable surface involved the use of an air cushion. An air cushion was positioned beneath each foot of the study participants. Surface electromyography was employed to measure muscle activation. %MVC was calculated by measuring muscle activation during squat execution and manual muscle testing. Results: The comparison of muscle activation during squats between stable and unstable surfaces revealed a significant difference in the rectus femoris and biceps femoris (P<.05). On stable surfaces, positive correlations were observed in the rectus femoris, vastus lateralis, and vastus medialis (P<.05). On unstable surfaces, positive correlations were found between the rectus femoris and vastus medialis (P<.05). Conclusion: This study observed an increase in muscle activation of the rectus femoris and biceps femoris during squats on an unstable support surface compared to a stable support surface.
        4,000원
        57.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: This study has mainly focused on finding pharmacological effects of ginsenosides that can reduce the unwanted side effects of the cytotoxic anticancer drugs and are highly effective on prostate cancer, colorectal cancer, liver cancer, hormone-dependent breast cancer, triple-negative breast cancer, and brain cancer (neuroblastoma). Methods: Minor and rare ginsenosides (GS) of Rh2 which have a high absorption ability and excellent pharmacological actions were treated with the 6 different types of cancer cell lines and their anticancer activities were investigated by analyzing gene expressions associated with various cancers through qPCR and other relevant methods. Results: In cancer cells exposed to Rh2, cell viability and cell migration were reduced, and apoptosis was induced. Each cancer cell was divided into three groups according to the cell proliferation response by Rh2; 1) A group in which the cell viability decreases inversely to an increase in Rh2 treatment concentration; 2) A group in which the cell viability rapidly decreases in Rh2 treatment above a certain level of concentration; 3) A group in which the cell viability was not suppressed below 20-30% even with 100 μL of Rh2, the highest concentration used in this study. Conclusions: It was shown that Rh2 has a significant effect on inhibiting the proliferation of prostate cancer cells and hormone-dependent breast cancer cells.
        4,300원
        58.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구에서는 치매 노인의 인지기능, 일상생활활동 의존도와 행동심리증상의 관계 분석 및 일상생 활활동 의존도의 매개효과를 검증하고자 하였다. 연구방법 : 건강보험공단에서 제공하는 노인 코호트 데이터베이스(Database; DB)의 2015년 데이터를 활 용하여 이차자료분석을 시행하였다. 연구 목적에 따라 2015년 장기요양인정신청자 중 2002~2015년 중 치매 상병코드로 1회 이상 진료를 받고 장기요양인정심사 결과 1~5등급 판정을 받은 자를 선별하였 고, 총 12,363명의 자료가 분석에 사용되었다. 분석을 위해 전체 변수에서 인지기능, 행동심리증상, 일 상생활활동 의존도를 추출하였다. 세 주요변인 간 연관성과 일상생활활동 의존도의 매개효과 분석을 위 하여 경로모형을 수립하고 각 경로의 직접효과와 간접효과 및 전체 모형의 총효과를 산출하였다. 결과 : 경로분석 결과 인지기능과 일상생활활동 의존도 간 효과값은 .616(p < .0001), 인지기능과 행동심 리증상 간 효과값은 .199(p < .0001), 일상생활활동 의존도와 행동심리증상 간 효과값은 .039(p = .0005)으로 세 경로 모두 유의한 연관성을 보였다. 세 변수의 경로모형 총효과값은 .223(p < .0001)이 었으며, 간접효과값은 .024(p = .0005)으로 일상생활활동 의존도의 부분매개효과가 존재하였다. 결론 : 본 연구에서 경로모형을 통해 인지기능과 행동심리증상 간의 관계에서 일상생활활동 의존도의 매개 효과를 검증한 결과, 일상생활활동 의존도는 인지기능의 저하가 행동심리증상에 미치는 영향을 부분적으 로 매개하고 있었다. 이러한 결과는 치매 환자의 행동심리증상 완화를 위해 일상생활활동 기능 증진 프 로그램이 유용할 수 있음을 시사하며 본 연구가 중재의 필요성 및 개발의 근거로 사용되기를 기대한다.
        4,200원
        59.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The external rotation (ER) exercise in performed at a 90° abduction of the shoulder joint is an effective to strengthen the infraspinatus. However, failure of the humeral head to control axial rotation during exercise can be increased the posterior deltoid over activity. Biofeedback training is an effective method of promoting motor learning and control it could look forward to activate the infraspinatus selectively by controlling the humeral head during exercise. Objects: The aim of this study was investigated that whether biofeedback for axial rotation was effective to activate selectively the infraspinatus during ER exercise. Methods: The 15 healthy males participated, and all subjects performed both ER exercise in a sitting position with shoulder abducted 90° under conditions with and without axial rotation biofeedback. Exercise was performed in a range of 90° ER, divided into three phases: concentric, isometric, and eccentric. The infraspinatus and posterior deltoid muscle activity were observed using surface electromyography. Results: Both infraspinatus activity (p < 0.01) and infraspinatus to posterior deltoid activity ratio (p = 0.01) were significantly higher with biofeedback however, posterior deltoid activity was significantly lower with biofeedback (p = 0.01). The infraspinatus muscle activity and muscle activity ratio were the highest in the isometric contraction type, and there were significant differences for all contraction types (p < 0.05). Whereas, the posterior deltoid activity was the lowest in the isometric contraction type, and showed a significant difference between isometric and other two contraction types (p < 0.05), but no significant different between concentric and eccentric contraction. Conclusion: Our results indicate that the axial rotation biofeedback during sitting ER exercise might be effective method to activating selective infraspinatus muscle and recommended to enhance the dynamic stability of the shoulder joint.
        4,000원
        60.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: In modern society, the use of computers accounts for a large proportion of our daily lives. Although substantial research is being actively conducted on musculoskeletal diseases resulting from computer use, there has been a recent surge in interest in improving the working environment for prevention. Objects: This study aimed to examine the effects of posture correction feedback (PCF) on changes in neck posture and muscle activation during computer typing. Methods: The participants performed a computer typing task in two sessions, each lasting 16 minutes. The participant’s dominant side was photographed and analyzed using ImageJ software to verify neck posture. Surface electromyography (EMG) was used to confirm the participant’s cervical erector spinae (CES) and upper trapezius muscle activities. The EMG signal was analyzed using the percentage of reference voluntary contraction and amplitude probability distribution function (APDF). In the second session, visual and auditory feedback for posture correction was provided if the neck was flexed by more than 15° in the initial position during computer typing. A 20-minute rest period was provided between the two sessions. Results: The neck angle (p = 0.014), CES muscle activity (p = 0.008), and APDF (p = 0.015) showed significant differences depending on the presence of the PCF. Furthermore, significant differences were observed regarding the CES muscle activity (p = 0.001) and APDF (p = 0.002) over time. Conclusion: Our study showed that the feedback system can correct poor posture and reduces unnecessary muscle activation during computer work. The improved neck posture and reduced CES muscle activity observed in this study suggest that neck pain can be prevented. Based on these results, we suggest that the PCF system can be used to prevent neck pain.
        4,000원
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