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        검색결과 1,889

        1.
        2024.10 구독 인증기관·개인회원 무료
        다중 운집 사고는 주로 도시 내 밀집된 공간에서 발생하며, 보행자의 자유로운 이동이 제한될 때 더욱 위험하다. 이러한 상황에서 군중의 물리적 압력이 더해지면 대형 참사로 이어질 수 있어 예방과 신속한 대응이 필수적이다. 사고 발생 가능성을 최소화하기 위해 서는 실시간으로 군중 밀도를 모니터링하고, 위험 상황을 사전에 경고할 수 있는 예측 시스템 구축이 필요하다. 그러나 현재 사용되는 CCTV 기반 모니터링 시스템은 특정 구역에 국한되며, 설치 및 유지 비용이 높아 광범위한 모니터링에는 한계가 있다. 이에 본 연구 에서는 Cell Transmission Model(CTM)을 기반으로 한 양방향 보행 시뮬레이션 프레임워크를 개발하고, 이를 모바일 통신 데이터로 검증하였다. 연구 과정에서는 먼저 1)단방향 보행 CTM을 구축하고, 2)이를 양방향 보행 CTM으로 확장하여 경계 셀을 재설정하고 유 입량을 조정하는 방식으로 진행했다. 또한, 다중 운집 사고를 구현하기 위해 체류 개념을 추가했다. 검증 단계는 1)대상지 선정, 2)보행 네트워크 구축, 3)시뮬레이션 적용, 4)모바일 통신 데이터와의 비교 검증 순으로 이루어졌다. 대상지는 이태원 참사가 발생했던 이태원 역 부근으로, 20×20m 셀 단위로 보행 네트워크를 구축했다. 시뮬레이션 결과, 모바일 통신 데이터와의 높은 유사도를 보였다. 본 연구 에서 개발한 시뮬레이션은 대규모 행사나 혼잡한 보행 환경에서 군중 밀집을 예측하고, 사고 가능성을 조기에 경고하는 데 활용될 수 있다. 특히, 대형 이벤트나 도시 재난 관리에서 실시간 대응 시스템의 기초 자료로 사용할 수 있다.
        3.
        2024.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Sestrin 2 (SESN2) is a member of the sestrin family of stress-induced proteins that negatively regulate agingassociated biological processes. This study aims to investigate the role of SESN2 in regulating the differentiation potential and senescence of mesenchymal stem cells (MSCs) derived from young and elderly donors. Bulk RNA sequencing revealed a common decline in the SESN2 mRNA levels in MSCs from elderly individuals, which was confirmed via reverse transcription-polymerase chain reaction and western blot analyses. SESN2 knockdown in MSCs from young donors resulted in phenotypic changes similar to those in MSCs from elderly donors, including an enhanced expression of senescence and adipogenic markers and diminished expression of osteogenic markers. To confirm the effect of decreased SESN2 expression on osteogenic and adipogenic differentiation, we induced Sesn2 knockdown in mouse bone marrow-derived MSCs. Sesn2 knockdown suppressed the mRNA expression of osteogenic marker genes, alkaline phosphatase activity, and matrix mineralization. Furthermore, Sesn2 knockdown enhanced mRNA expression of the adipogenic marker genes and intracellular lipid accumulation. These results suggest that a decline in SESN2 expression during aging contributes to the shift of MSC differentiation from osteogenic to adipogenic lineage.
        4,000원
        4.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, active research in Korea and worldwide has begun to focus on gene function and cultivar development using gene editing tools. This research, in addition to studies on edible mushroom, aims to enhance the physical and biochemical characteristics of mushrooms for applications in materials and substance production. For these studies, efficient isolation of protoplasts from the target mushroom is critical. However, several commercial cell wall-lysing enzyme cocktails, including Novozyme234, Glucanex, and Lysing enzymes, have recently been discontinued. In this study, we aimed to identify alternative enzyme systems to replace the discontinued cell wall-lysing enzymes for stable isolation of protoplasts from Ganoderma lucidum. To select an optimal osmotic buffer, enzyme function in 0.6 and 1.2 M Sorbitol, Sucrose, Mannitol, and KCl was assessed. The effect of reaction time was also evaluated. Protoplast isolation efficiency of each alternative enzyme was tested using lysing enzymes from Trichoderma harzianum, Chimax-N, and Yatalase, either individually or in combination. This matrix of studies identified enzymes and optimal conditions that could replace the discontinued lysing enzymes.
        4,000원
        5.
        2024.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Among various organic materials suitable for silicon-based inorganic-organic hybrid solar cells, poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) has been extensively studied due to its high optical transmittance, high work function, and low bandgap characteristics. The electro-optical properties of PEDOT:PSS have a significant impact on the power conversion efficiency of silicon-organic hybrid solar cells. To enhance the photovoltaic properties of the silicon-organic hybrid solar cells, we developed a method to improve the properties of the PEDOT:PSS film using Ag nanowires (NW) instead of conventional solvent addition methods. The influence of the Ag NW on the electro-optical property of the PEDOT:PSS film and the photovoltaic performance of the silicon-organic hybrid solar cells were investigated. The addition of Ag NW further improved the sheet resistance of the PEDOT:PSS film, enhancing the performance of the silicon-organic hybrid solar cells. The present work using the low sheet resistance PEDOT:PSS layer paves the way to develop simple yet more efficient siliconorganic hybrid solar cells.
        4,000원
        6.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cirsium setidens, Allium hookeri, Aronia melancocarpa, are popular dietary ingredients for Asian cuisine or beverage. this study attempted to search and report the antioxidant activity of extracts of aronia, gondre and samchae, which are used for food in Korea. As a result, total phenol content and DPPH radical scavenging activity tended to increase, and Gondre extract showed the highest DPPH radical scavenging activity effect. The results of a study on the ABTS radical scavenging activity of extracts of Gondre, Aronia, and Samchae showed a tendency for radical scavenging activity to increase as the concentration increased. Gondre hot water extract showed the highest ABTS radical scavenging activity. In this way, antioxidant activity was shown in the order of Gondre, Aronia, and Samchae, and the concentration showed a high activity effect at high concentrations. In the cell protection effect results, the concentration of Gondre extract was 500 μg/mL, the Samchae alcohol extract was used at concentrations of 2.5, 5, 7.5, and 10 μg/mL, and the Aronia extract was used at concentrations of 125 μg/mL. and showed a cytoprotective effect at 250 μg/mL. We hope that these research results will be used as basic data for the development of various functional foods.
        4,000원
        7.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        갯까치수염은 다육성의 2년생 초본 자생식물로서, 제주도, 울릉도를 비롯하여 남해안 지역에서 자라며 자생지의 환경에 맞게 내염성이 크다는 특징이 있고, 다양한 환경에 적응하며 관상가치가 높다. 관련 문헌을 보면 발아조건과 개화조절에 대한 연구만 보고되었고 그 중간단계인 재배에 관한 연구가 부족하여 대량생산을 위한 공정육묘법 개발의 일환으로 이 실 험을 수행하였다. 실험은 플라스틱온실 내에서 발아시킨 1cm 전후의 묘를 50, 128, 200구 트레이에 이식하여 한국원시표 준액(N-P-K-Ca-Mg, 15-3-6-8-4)을 각각 권장 EC농도의 0, 0.5, 1, 2배 농도로 매일 5분간 순환식으로 저면 관수하여 6주간 재배 후 초장, 근장, 엽수, 뿌리수, SPAD, 생체중, 건물 중을 측정하였다. 갯까치수염 생육은 플러그 셀 크기 50셀에 서 생육이 가장 높았다. 양액농도에 따른 갯까치수염의 생육 은 0.5배액에서 초장과 근장의 수치가 가장 높았으며, 모든 생육지표가 양액 농도변화에 따른 차이가 발생하는 것으로 나 타났고 실질적인 총 생산량의 지표라고 할 수 있는 지상부와 지하부의 건물중에 영향을 미치지 않았다는 결과가 나온 것으 로 미뤄 육묘단계에서 양액의 농도가 셀 크기보다 갯까수치염 의 묘 생육에 더 영향이 큰 것으로 보인다. 갯까치수염의 조직 충실도 면에서 0.5, 1, 2배액의 200구에서 가장 높은 결과값 들이 나왔다. 결과적으로 기존 원시표준액에 비해 생장에 유 리한 결과를 보이며 비료도 절약할 수 있는 0.5배 양액처리조 건이 갯까치수염 육묘 재배에 더 효율적이였다.
        4,000원
        8.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Probiotic lactic acid bacteria are live microorganisms that provide health benefits when administered in adequate amounts and may exhibit antiproliferative effects on various cancer cell lines, including colon cancer. This study investigates the cytotoxic effects of three Lactobacillus strains - Limosilactobacillus (L.) reuteri VA 102, Ligilactobacillus (L.) animalis VA 105, and Limosilactobacillus (L.) reuteri KCTC 3594 (ATCC 23272) - on mouse colon carcinoma cells (CT-26). Live cells, heat-killed cells, and cell-free supernatant (CFS) of Lactobacillus sp. were prepared and used to treat CT-26 cells at different concentrations. The cytotoxic effect was assessed using the MTT assay. The results indicated that the CFS of all strains significantly reduced the viability of CT-26 cells in a dose-dependent manner, with the VA 102 strain showing the most pronounced effect. Heat-killed cells of L. reuteri VA 102 and L. reuteri KCTC 3594 (ATCC 23272) also reduced cell viability. These findings suggest the potential anticancer properties of these Lactobacillus strains and indicate that CFS and heat-killed cells may offer a safer and more effective alternative to live bacteria for therapeutic applications. Our study contributes to the understanding of the potential of Lactobacillus strains, particularly L. reuteri VA 102, L. reuteri KCTC 3594 (ATCC 23272), and L. animalis VA 105, as possible candidates for cancer treatment and control.
        4,000원
        9.
        2024.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Ophiopogonin D (OPD) is a steroidal glycoside derived from Ophiopogon japonicus , a traditional Chinese medicine with diverse biological activities, including antithrombosis, anti-inflammation, and antitussive effects. To investigate the cellular effects and mechanisms of OPD on oral squamous cell carcinoma, cell viability was explored, and the effects of OPD on cell cycle regulators, apoptotic marker proteins, and key proteins involved in metastasis and signaling pathways were examined by MTT assay and Western blotting in YD38 cells. OPD strongly inhibited cell proliferation and induced caspase-dependent apoptosis of YD38 cells by suppressing the cell cycle and activating caspase-3 and poly ADP ribose polymerase. Additionally, OPD suppressed the expression of vital proteins regulating metastasis and proliferation within the integrin/matrix metalloproteinases/FAK and AKT/PI3K/mTor pathways. Thus, OPD can be a potential treatment candidate for gingival cancer.
        4,000원
        10.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Orthokeratinized odontogenic cysts are developmental cysts that occur in the jaw that account for approximately 7%–17% of all cysts in the jaws. Studies have shown that malignant transformation of odontogenic cysts most often occurs in inflammatory cysts, such as periapical cysts, but malignant transformation of orthokeratinized odontogenic cysts has also been reported. In this report, we present an uncommon case of squamous cell carcinoma arising from an orthokeratinized odontogenic cyst.
        4,000원
        18.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Herein, the present work focuses on the effective counter electrode for dye-sensitized solar cells. The bottom–up approach was adapted to synthesize Mn2O3 nanorods via the hydrothermal method and the reduced graphene oxide was merged with Mn2O3 to prepare a nanocomposite. The prepared nanocomposites were subjected to physio-chemical and morphological characterizations which revealed the crystalline nature of Mn2O3 nanorods. The purity level rGO was characterized using the Raman spectrum and the Fourier transform infrared spectroscopy employed to find the functional groups. The morphological micrographs were visualized using SEM and TEM and the high aspect ratio Mn2O3 nanorods were observed with 5–7 nm and supported by rGO sheets. The electrocatalytic nature and corrosion properties of the counter electrode towards the iodide electrolyte were studied using a symmetrical cell. The as-synthesized nanocomposites were introduced as counter electrodes for DSSC and produced 4.11% of photoconversion efficiency with lower charge transfer resistance. The fabricated DSSC devices were undergone for stability tests for indoor and outdoor atmospheres, the DSSC stability showed 93% and 80% respectively for 150 days.
        4,000원
        19.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 온실가스 배출을 감축하기 위해 메탄올을 추진 연료로 사용하는 선박에 수소 연료전지 시스템이 추가된 하 이브리드 시스템 공정을 설계하였다. Case1에서는 메탄올 연료 엔진 시스템을 설계하여, 엔진에 가솔린 대신 메탄올을 연료로 공급했 을 때의 배기가스 배출량을 알아보았다. Case2에서는 Case1에 메탄올 개질 시스템을 추가해, 수소연료전지 시스템을 설계하였다. 이 하 이브리드 시스템에서는 그레이 수소를 생산하며, 엔진과 연료전지의 출력을 조합하여 선박을 구동한다. 하지만 그레이 수소는 수소를 생산하는 과정에서 탄소를 배출한다는 단점이 있다. 이 점을 보안하기 위해 Case3에서는 CCU시스템을 추가하였다. Case2에서 배출한 Flue gas의 이산화탄소를 포집한 후, 그레이 수소와 합성해 블루 메탄올을 생산하였다. 본 연구에서는 Case study를 통해 개질 온도22 0℃, 개질 압력500kPa, SCR은 1.0, flow ratio가 0.7일 때 최적의 운전조건임을 알 수 있었다. Case3의 시스템은 Case1에 비해 탄소 배출량 을 42% 감소시켰다. 결과적으로, Case3의 하이브리드 시스템을 통해 선박의 이산화탄소 배출을 유의미하게 저감할 수 있을 것으로 예 상한다.
        4,500원
        20.
        2024.04 구독 인증기관·개인회원 무료
        The baculovirus expression system (BES) utilize the p10 or polyhedrin promoter, a very late promoter that exhibits strong transcriptional activity primarily at the end of viral infection, to produce useful recombinant proteins. The burst sequence of the very late promoter is essential for strong transcription, and VLF-1 is a transcription factor that binds specifically to the burst sequence, and it has been reported that it can regulate the amount and timing of expression of protein by the very late promoter. Recently, a VLF-1 constitutively expressing cell line was constructed to increase the production of the target protein, but the effect was minimal. In this study, to find the optimal VLF-1 expression conditions to increase target protein production efficiency, we controlled the expression of VLF-1 through various promoters and evaluated the target protein expression efficiency by the p10 promoter accordingly.
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