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        검색결과 693

        1.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hangovers, resulting from excessive alcohol intake, manifest hours after drinking, causing symptoms like thirst, headache, and fatigue. Alcohol is metabolized in the liver by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), with acetaldehyde and reactive oxygen species contributing to toxic effects. Morning Care (MC) products were evaluated in male and female mice to assess their impact on alcohol metabolism and hangover alleviation. The study revealed that pre-administration of MC products led to a significant reduction in blood ethanol and acetaldehyde concentrations postalcohol ingestion. This remarkable finding suggests a potential breakthrough in hangover relief. Enhanced ADH and ALDH activities were observed in blood and liver samples, indicating improved alcohol metabolism. Interestingly, gene expression levels of ADH and ALDH in the liver did not show significant differences, suggesting that MC products likely enhance enzyme activities through post-translational modifications rather than altering gene expression. These findings underscore the potential of MC products to mitigate hangover symptoms by enhancing alcohol metabolism.
        4,000원
        2.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-entropy alloys (HEAs) have been reported to have better properties than conventional materials; however, they are more expensive due to the high cost of their main components. Therefore, research is needed to reduce manufacturing costs. In this study, CoCrFeMnNi HEAs were prepared using metal injection molding (MIM), which is a powder metallurgy process that involves less material waste than machining process. Although the MIM-processed samples were in the face-centered cubic (FCC) phase, porosity remained after sintering at 1200°C, 1250°C, and 1275°C. In this study, the hot isostatic pressing (HIP) process, which considers both temperature (1150°C) and pressure (150 MPa), was adopted to improve the quality of the MIM samples. Although the hardness of the HIP-treated samples decreased slightly and the Mn composition was significantly reduced, the process effectively eliminated many pores that remained after the 1275°C MIM process. The HIP process can improve the quality of the alloy.
        4,300원
        3.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Helicobacter pylori are known as a causative agent of gastritis, gastric duodenum and peptic ulcer, and gastric cancer, and multiple drug use is associated with various side effects in patients. The discovery of antibacterial substances against H. pylori from Korean resource plants is an important substitute for antibiotics. 52 species of Korean resource plants were collected and extracted with 50% ethanol, and antibacterial activity against H. pylori was measured using the disk diffusion method. The toxicity of plant extracts to human gastric adenocarcinoma(AGS) cells was measured by MTT assay, and the level of IL-8 secreted when gastric epithelial cells were inoculated with H. pylori was measured. As a result of measuring the antibacterial activity of H. pylori, antibacterial activity was confirmed in 38 plant extracts. The plant species with the strongest antibacterial activity were Chrysanthemum indicum, Rheum rhabarbarum, Patrinia scabiosaefolia and Petasites japonicus. C. indicum was not cytotoxic to H. pyroli-infected AGS cells and showed anti-inflammatory effects. This study's results can be used to develop healthy, functional foods and medical materials.
        4,000원
        4.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To understand the detrimental effects of triclosan on Java medaka (Oryzias javanicus) embryos, fertilized embryos were exposed to different concentrations (1, 10, 50, 100, 200, 400, 600, 800, and 1,000 μg l-1) of triclosan until hatching. Then, we examined the survival rate and developmental parameters as well as alterations in antioxidant constituents and DNA damage markers. The results showed dose-dependent mortality, hatching delays, and developmental abnormalities in the embryos. Additionally, there were significant increases in oxidative stress parameters and antioxidant responses, along with elevated DNA damage. These findings suggest that sublethal concentrations of triclosan induce toxic effects through oxidative stress on Java medaka embryos, as evidenced by changes in in vivo parameters and biochemical constituents.
        4,000원
        8.
        2024.04 구독 인증기관·개인회원 무료
        This study aims to systematically investigate the insect diversity within the distinct coastal grassland and mountain habitats of East Busan, Busan Metropolitan City. The objective is to gather foundational data that will inform natural environment conservation plans and contribute to policy formulation. Employing a comprehensive collection approach, we utilized trapping nets, pitfall traps, and flying insect traps to capture a broad spectrum of insect species. The investigation identified a rich diversity of 132 species across 9 orders and 52 families. Coleoptera emerged as the most prevalent order with 13 families and 41 species, followed by Diptera with 8 families and 24 species, and Lepidoptera with 9 families and 21 species. To assess the biodiversity and structure of these communities by habitat type, we applied several biodiversity indices: the Shannon-Wiener index (H'), Margalef index (R), and Pielou evenness index. Coastal grasslands exhibited an H' of 3.153, R of 11.08, and a Pielou evenness of 0.371; coastal mountains showed an H' of 2.922, R of 13.02, and a Pielou evenness of 0.202. These metrics reveal no significant differences in diversity and evenness between the two habitats. The endangered Copris tripartitus was notably observed in coastal grasslands, alongside 20 species classified as Least Concern (LC) in the National Red List across both habitats. The comparative analysis of biodiversity and evenness levels across coastal grassland and mountain areas highlights the ecological significance of both habitats in supporting a diverse insect fauna. The detection of endangered and LC species within these areas emphasizes the critical need for ongoing monitoring and the development of effective conservation strategies tailored to protect Busan's coastal ecosystems. The findings underscore the necessity of conducting periodic surveys to monitor faunal changes and inform conservation efforts actively. By ensuring the continued protection of insect diversity, these efforts will play a pivotal role in maintaining the ecological integrity of coastal areas, thereby supporting broader environmental conservation objectives.
        9.
        2024.04 구독 인증기관·개인회원 무료
        This study aimed to collect foundational data essential for devising a natural environment conservation plan and implementing relevant policies. It underscores the significance of understanding the current state of the natural environment. Our research concentrated on surveying the biodiversity and distribution of key natural habitats within Busan Metropolitan City, with the goal of gathering crucial data to guide the development of conservation and management strategies. The focus of our investigation was on the insect populations in Ilgwang, covering two primary habitats: mountains and wetlands. The survey, conducted from July to September 2023, utilized various collection methods, including pitfall traps, fly traps, sweeping nets, and aspirators. Our findings documented the presence of 109 species across 88 genera, 50 families, and 9 orders. Specifically, the study identified two species from the order Odonata, two from Blattodea, one from Mantodea, six from Orthoptera, eleven from Hemiptera, twenty-nine from Coleoptera, twelve from Diptera, ten from Lepidoptera, and thirty-five from Hymenoptera. Through community analysis, biodiversity indices were calculated, revealing a Shannon-Wiener index (H') of 4.07 for mountain habitats and 3.92 for wetlands. The Margalef richness index (R) displayed values of 13.92 for mountains and 14.78 for wetlands, while the Pielou evenness index indicated values of 0.96 and 0.91, respectively. Among the identified species, one was classified as endangered, and thirteen were designated as of Least Concern, according to legal protection statuses.
        10.
        2024.04 구독 인증기관·개인회원 무료
        Spodoptera frugiperda, commonly known as the fall armyworm (FAW), is a major pest across the globe due to its broad host range and distribution worldwide. We investigated the function of microRNAs (miRNAs) in the detoxification of insecticides, with a specific focus on its susceptibility to chlorantraniliprole which is widely utilized insecticide for its management. miRNAs are small non-coding RNA molecules, crucial for post-transcriptional regulation of gene expression. This study aims to elucidate the impact of these miRNAs on the expression of cytochrome P450 genes, which play a significant role in conferring insecticide resistance. We identified notable changes in the abundance of two specific miRNAs, sfr-miR-10465-5p and sfr-miR- 10476-5p through RNA sequencing, after chlorantraniliprole exposure. These miRNAs exhibited significantly high expression in the fat body tissue, while showing relatively lower expression in the head, midgut, and malpighian tubules. Further analysis suggested that these miRNAs might target specific cytochrome P450 genes, like CYP4C1 and CYP4C21, which are known to play a role in insecticide resistance development. Experimentation with miRNA mimics through microinjection revealed a notable increase in the survival rates of S. frugiperda larvae when subjected to chlorantraniliprole exposure, with a significant reduction in CYP4C1 and CYP4C21 gene expression levels. This suggests a direct connection between the miRNAs and the increased tolerance of Spodoptera larvae to the insecticide. Our research presents the complex function of miRNAs in gene expression regulation related to insecticide resistance, offering valuable insights into the molecular mechanisms of chlorantraniliprole resistance in S. frugiperda. These findings pave the way for further investigations into miRNA roles and their potential in managing pesticide resistance in agricultural pests.
        11.
        2024.04 구독 인증기관·개인회원 무료
        연구에서는 '누리금잠'이라 명명된 새로운 누에 신품종을 개발하였으며, 이는 황색 고치와 세리신 고치를 생산 하는 두 개의 기존 계통, 잠311과 D751의 교배를 통해 육성되었습니다. 이 신품종은 첫 교배 실험을 거친 2019년 봄부터 2021년 봄까지 총 4차례의 생산력 평가를 진행했으며, 이어진 2022년 봄부터 2023년 가을까지 4차례에 걸친 지역 적응성 평가를 통해 2023년 가을에 새로운 품종으로 공식 인정받았습니다. '누리금잠'은 봄과 가을 시즌에 각각 평균 부화율 86.9%, 89.6%를 기록하였고, 유충의 평균 성장 기간은 봄에는 21일과 12시간, 가을에는 19일과 22시간으로 나타났습니다. 세리신 고치의 평균 생산성은 봄에 79.17%, 가을에 74.9%였으며, 수확된 세리 신의 평균 중량은 누에고치 250개를 기준으로 봄에 6g, 가을에는 7.7g으로 측정되었습니다. 이와 같은 결과는 '누리금잠'이 높은 부화율과 우수한 세리신 생산성을 갖추고 있음을 시사합니다. 이는 세리 신 기반 제품의 생산 효율성을 증가시킬 뿐만 아니라, 양잠산업의 경제적 가치를 상승시키는 데 기여할 수 있을 것으로 생각됩니다.
        12.
        2024.04 구독 인증기관·개인회원 무료
        The fall armyworm, Spodoptera frugiperda, has developed extremely high levels of resistance to chlorantraniliprole and other classes of insecticides in the field. As microRNAs (miRNAs) play important roles in various biological processes through gene regulation. we examined the miRNA profile of S. frugiperda in response to Chlorantraniliprole, Indoxacarb and Thiamethoxam. Transcriptome analysis showed significant changes in the abundance of some miRNAs after treatment of S. frugiperda larvae with LC20 concentrations of three insecticides. A total of 197 miRNAs were systematically identified from S. frugiperda, and 16, 9, 2 miRNAs were differentially expressed after treatments of three insecticides. Importantly, three miRNAs were significantly downregulated and three were upregulated by RT-qPCR after treatment the LC50 of three insecticides with S. frugiperda larvae. Microinjection of agomirs of these six miRNAs into S. frugiperda larvae resulted in significant changes in mortality rates when exposed to three insecticides. Additionally, we also screened potential target genes for some of differentially expressed miRNAs, which may play important roles in insecticide resistance development. These findings provide valuable insights into the molecular mechanisms of insecticide resistance and underscore the potential of miRNAs as targets for the development of novel pest control strategies in S. frugiperda.
        13.
        2024.04 구독 인증기관·개인회원 무료
        A new fumigant, carbonyl sulfide (COS), has potential for use as a replacement for methyl bromide, yet its mechanism of toxicity to insects remains poorly understood. In this study, transcriptome analysis was performed on Tribolium castaneum malpighian tubules and fat bodies, which are known to play an essential role in energy storage and utilization in insect species. In total, upon exposure to COS, 3,034 and 2,973 genes were differentially expressed in the T. castaneum malpighian tubules and fat body, respectively. These differentially expressed genes comprise a significant number of detoxification-related genes, including 105 P450s, 18 glutathione S-transferases (GSTs), 82 ABC transporters, 25 UDP-glucosyltransferases and 42 carboxylesterases and mitochondrial–related genes, including 9 complex Ⅰ genes, 2 complex Ⅱ genes, 1 complex Ⅲ gene, 9 complex IV genes, 8 complex V genes from both malpighian tubules and fat body tissues. Moreover, KEGG analysis demonstrated that the upregulated genes were enriched in xenobiotic metabolism by ABC transporters and drug metabolism by other enzymes. We also investigated the role of carbonic anhydrases (CAs) in toxicity of COS using dsRNA treatment in T. castaneum. These results show that CA genes have a key role in toxicity of the COS. Furthermore, the results of transcriptomic analysis provide new insights into the insecticidal mechanism of COS fumigation against T. castaneum and eventually contribute to the management of this important stored grain pests.
        14.
        2024.04 구독 인증기관·개인회원 무료
        The study of blowfly (Diptera, Calliphoridae) biodiversity and distribution is crucial for forensic investigations involving cadavers. Abiotic and biotic factors, such as seasonality and habitat type, have significant impacts on blowfly populations. However, few forensic entomology studies have been conducted in South Korea, particularly the Gyeongsangnam-do region. To address this, in this study, an extensive year-long survey was conducted to analyze the compositions, habitat preferences, distribution, and seasonal abundance of forensically relevant blowflies in urban and forested habitats in Gyeongsangnam-do, utilizing mouse carcass-baited traps set for 48 h each month. A total of 3,478 adult blowflies were recorded, encompassing six genera and 14 species, with a noted absence of specimens during the winter months. The predominant species was Lucilia porphyrina, accounting for 37.1% of the total sample, followed by Chrysomya pinguis (27.5%), Lucilia sericata (7.6%), and Lucilia illustris (7.1%). The species composition was consistent across all surveyed regions; however, seasonal variation in species diversity was evident, with a peak in spring and decline in summer. Notably, certain species exhibited clear preferences for either urban (Calliphora calliphoroides and L. sericata) or forested habitats (L. porphyrina and Ch. pinguis). This pioneering study elucidates the diverse blowfly communities in Gyeongsangnam-do, highlighting significant seasonal and habitat-dependent variations.
        15.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, the marine medaka Oryzias javanicus underwent a 96 h exposure to two concentrations of the red tide dinoflagellate Karenia mikimotoi (1,000 and 5,000 cells mL-1), and the temporal variations in biochemical responses related to antioxidant and immunity parameters were assessed in the liver tissue. The study revealed a significant increase in ichthyotoxicity with elevated cell concentrations of K. mikimotoi, especially evident at 96 h in marine medaka exposed to 5,000 cells mL-1. At 1,000 cells mL-1 of K. mikimotoi, the opercular respiratory rate showed a significant increase, whereas exposure to 5,000 cells mL-1 resulted in a lowered rate. The intracellular malondialdehyde content was significantly elevated in response to both cell concentrations at 96 h. Regarding glutathione content, levels were significantly increased by exposure to both cell concentrations. Catalase and superoxide dismutase enzymatic activities experienced an increase at 1,000 cells mL-1 of K. mikimotoi, while their activities were reduced at 5,000 cells mL-1 at 96 h. The analysis of two immunity parameters, alternative complement pathway and lysozyme, demonstrated significantly reduced activities in the liver tissue exposed to 5,000 cells mL-1 of K. mikimotoi. These findings aim to enhance the understanding of K. mikimotoi toxicity in marine fish by offering insights into biochemical responses associated with harmful algal blooms.
        4,000원
        16.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Throughfall (TF)—as a diffusive hydrological water flux—significantly affects ecohydrological and biogeochemical processes within forest ecosystems. Recent investigations have revealed the impact on TF generation processes within unmanaged coniferous plantations of under-canopy structures, particularly those laden with dead branches, as well as upper-canopy structures. However, spatiotemporal variations in TF in such plantations remain unexplored. We investigated these variations in TF in a 33-year-old unmanaged Japanese cypress (Chamaecyparis obtusa Endl.) plantation, laden with dead branches, with a high stand density (SD) of 2,500 stems ha−1. Over a two-year period (May 2017 to May 2019), we conducted weekly TF measurements using 28 manual-type TF collectors. We compared the present TF ratio and canopy water storage capacity (S) with those of previous investigations conducted on Japanese cypress plantations. Moreover, we assessed key indices contributing to spatiotemporal TF variations (canopy cover: CC and distance to the nearest stem: TFd) and potentially influential dead branch indices (number of dead branches: TFdb and vertical spacing length on a stem: TFs) to elucidate TF spatial patterns. The results showed that the TF ratio was notably lower than that in previous studies (n = 13), with SD (r = –0.92, p < 0.001) and S (r = –0.87, p < 0.001) emerging as key influential factors among other stand-structure parameters. Spatial TF patterns exhibited a decreasing trend as the gross rainfall (GR) increased. Temporal stability was not significantly associated with CC (r = 0.120, p = 0.544), TFd (r = 0.068, p = 0.731), TFdb (r = 0.211, p = 0.281), or TFs (r = 0.206, p = 0.292) for any of the TF collectors. These findings underscore the important role of GR in determining the spatial variation of TF. Collectively, our results contribute to an enhanced understanding of TF spatiotemporal heterogeneity in unmanaged Japanese cypress plantations with dead branches.
        4,600원
        17.
        2023.11 구독 인증기관·개인회원 무료
        The demand for transportation is increasing due to the continuous generation of radioactive wastes. Especially, considering the geographical characteristics of Korea and the location characteristics of nuclear facilities, the demand for maritime transportation is expected to increase. If a sinking accident happens during maritime transportation, radioactive materials can be released into the ocean from radioactive waste transportation containers. Radioactive materials can spread through the ocean currents and have radiological effects on humans. The effect on humans is proportional to the concentration of radioactive materials in the ocean compartment. In order to calculate the concentration of radioactive materials that constantly flow along the ocean current, it is necessary to divide the wide ocean into appropriate compartments and express the transfer processes of radioactive materials between the compartments. Accordingly, this study analyzed various ocean transfer evaluation methodologies of overseas maritime transportation risk codes. MARINRAD, POSEIDON, and LAMER codes were selected to analyze the maritime transfer evaluation methodology. MARINRAD divided the ocean into two types of compartments that water and sediment compartments. And it was assumed that radionuclides are transfered from water to water or from water to sediment. Advection, diffusion, and sedimentation were established as transfer process for radionuclides between compartments. MARINRAD use transfer parameters to evaluate transer processes by advection, diffusion, and sedimentation. Transfer parameters were affected by flow rate, sedimentation rate, sediment porosity, and etc. POSEIDON also divided the ocean into two types that water and sediment compartment, each compartments was detaily divided into three vertical sub-compartment. Advection, diffusion, resuspension, sedimentation, and bioturbation were established as transport processes for radionuclides between compartments. POSEIDON also used transfer parameters for evaluating advection, diffusion, resuspension, sedimentation, and bioturbation. Transfer parameters were affected by suspended sediment rates, sedimentation rates, vertical diffusion coefficients, bioturbation factors, porosity, and etc. LAMER only considered the water compartment. It divided the water compartment into vertical detailed compartments. Diffusion, advection and sedimentation were established as the nuclide transfer processes between the compartments. To evaluated the transfer processes of nuclides for diffusion and advection, LAMER calculated the probability with generating random position vectors for radionuclides’ locations rather than deterministic methods such as MARINRAD’s transfer parameters or POSEIDON’s transfer rates to evaluate transfer processes. The results of this study can be used as a basis for developing radioactive materials’ ocean transfer evaluation model.
        18.
        2023.11 구독 인증기관·개인회원 무료
        Heavy water primary system decontamination technology is essential to reduce worker exposure and improve safety during maintenance and decommissioning of nuclear facilities. Advanced decontamination technology development aims to secure controlled decontamination technologies that can reduce the cost of radiation exposure and dramatically reduce the amount of secondary waste generated when decontaminating large equipment and large-area facilities. We conducted a study to identify candidate corrosion inhibitors through the literature and analyze the degree of corrosion of carbon steel samples. Countries with advanced nuclear technology have developed chemical decontamination technology for the entire nuclear power generation system and applied it to the dismantling and maintenance of nuclear power plants. In the decontamination process, the corrosion oxide film must be removed. If the base metal is corroded by the decontaminant in this process, additional secondary waste is generated and treatment costs increase. Therefore, it is necessary to develop a corrosion inhibitor that inhibits the corrosion of the carbon steel base metal in the decontamination process to generate a secondary waste liquid that is favorable for waste reduction and treatment. In this presentation, a study was conducted to analyze the extent of corrosion on a carbon steel base material and identify candidate materials for corrosion inhibition testing. Samples were analyzed using optical microscopy and EPMA analysis to determine the thickness of the corroded oxide film. EPMA analysis also allowed us to map the elemental distribution of the carbon steel corrosion layer, which we plan to quantify in the future. The candidate materials for organic-based corrosion inhibitor were also selected based on their inhibition mechanism; having high electronegative elements for coordinate covalent bonding at metal surface and hydrophobic nonpolar group for preventing access of corrosive substances.The selection of candidate materials for corrosion inhibition testing was based on the mechanism of the corrosion inhibitor. Organic-based corrosion inhibitors are adsorbed by donor-acceptor interactions between metal surfaces and highly electronegative elements. Corrosion can also be inhibited by arranging hydrophobic nonpolar groups on metal surfaces in the solution direction to prevent access of corrosive substances.
        19.
        2023.11 구독 인증기관·개인회원 무료
        Despite its advantages such as safety, unnecessary pretreatment, and decontamination of waste with complex geometry, conventional ultrasonic decontamination technology has been only used to remove loose contaminants, oil and grease, not fixed contaminants due to the limitations in increasing the intensity in the high frequency range. Thus, ultrasound has been used as an auxiliary method to accelerate chemical decontamination of radioactive wastes or chemicals were added to the solution to increase the decontamination efficiency. The recently developed high-intensity focused ultrasound (HIFU) decontamination technology overcomes these limitations by combining multiple frequencies of ultrasonic waves in a specific arrangement, making it possible to remove most fixed contaminants, including radioactive micro particles less than 1 micrometer within half an hour. KEPCO NF and EnesG developed mobile HIFU decontamination equipment and successfully demonstrated the decontamination effect on various radionuclides found in nuclear power plants by treating radioactive metal waste to the level below free release criteria. The mobile HIFU decontamination equipment used in the demonstration can be operated anywhere where water is supplied, including controlled area in nuclear power plants, and is expected to be used widely for decontamination and free release of metal radioactive wastes.
        20.
        2023.11 구독 인증기관·개인회원 무료
        The occurrence of shear failure in a rock mass, resulting from the sliding of joint surfaces, is primarily influenced by the surface roughness and contact area of these joints. Furthermore, since joints serve as crucial conduits for the movement of water, oil, gas, and thermal energy, the aperture and geometric complexity of these joints have a significant impact on the hydraulic properties of the rock mass. This renders them critical factors in related industries. Therefore, to gain insights into the mechanical and hydraulic behavior of a rock mass, it is essential to identify the key morphological characteristics of the joints mentioned above. In this study, we quantified the morphological characteristics of tensile fractures in granitic rocks using X-ray CT imaging. To accomplish this, we prepared a cylindrical sample of Hwang-Deung granite and conducted splitting tests to artificially create tensile fractures that closely resemble rough joint surfaces. Subsequently, we obtained 2D sliced X-ray CT images of the fractured sample with a pixel resolution of approximately 0.06 mm. By analyzing the differences in CT numbers of the rock components (e.g., fractures, voids, and rock matrix), we isolated and reconstructed the geometric information of the tensile fracture in three dimensions. Finally, we derived morphological characteristics, including surface roughness, contact area, aperture, and fracture volume, from the reconstructed fracture.
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