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        검색결과 6

        1.
        2023.10 구독 인증기관·개인회원 무료
        Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.
        3.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The PyeongChang 2018 Winter Paralympic Games (WPG) being one of the most successful Paralympic Games (PG) in modern athletic world history, hosted the largest number of elite athletes representing 49 National Paralympic Committees (NPCs). Objects: The present investigation highlighted the demographic and clinical characteristics of injured athletes and non-athletes and the physiotherapy services provided during the PyeongChang 2018 WPG. Methods: Prospective descriptive epidemiology study, in which the study group comprised of 201 participants (51 athletes and 150 non-athletes) who were admitted to and utilized the polyclinic physiotherapy service of 2018 PyeongChang WPG in Physiotherapy Department of Paralympic Village from March 1, 2018 to March 20, 2018. Results: Qualitative frequency analysis of injury type demonstrated highest number of chronic injuries (51%, n = 100) in athletes and non-athletes. Anatomical injury site analysis revealed that the spine and shoulder areas were affected with equal frequency for athletes (54.9%, n = 14), whereas for non-athletes, the frequencies of spine and shoulder area injuries were 36.7% (n = 55) and 26% (n = 39), respectively. The Pyeongchang WPG showed a high rate of athletes visiting the physiotherapy service during the pre-competition period (33.3%, n = 50), which may have led to smaller incidence rate of traumatic injury. The physiotherapy treatment service analysis demonstrated that manual therapy (35.4%, n = 230) was most commonly utilized, followed by transcutaneous electrical nerve stimulation/interference current therapy (TENS/ICT), therapeutic massage and therapeutic exercise. Conclusion: We established the importance of prophylactic and preventive physiotherapy services to reduce the risk of sports injuries during WPG.
        4,000원
        4.
        2018.10 서비스 종료(열람 제한)
        Background : Acetylcholine is related with various functions, including cognition and behavior, and increased activity of cholinesterase has been reported in the brains of people suffering from Alzheimer’s disease (AD). As such, the inhibition of cholinesterase activity could be a means of ameliorating neuronal degenerative diseases such as AD. Reactive oxygen species (ROS) can cause neuronal cell damage. The AchE inhibitory effects of Sorghum bicolor (SB) have been revealed by research. This study was conducted to compare the cholinesterase inhibitory effects and anti-oxidative effects of SB extracts according to their extraction conditions. Methods and results : Eight extracts were prepared from SB seed, which was extracted using three different methods including room temperature extraction, reflux extraction at 85℃, and accelerate solvent extraction (ASE) at 50℃ by using distilled water and/or ethanol as a solvent. AchE and BuchE inhibition activities of the extracts were measured in vitro, and their inhibitory activities on ROS, nitric oxide (NO) production and cell proliferation were analyzed in lipoppolysacchride–treated BV2 mouse microglia cells. According to the results of the experiments, the 50% ethanol extract obtained by room temperature extraction showed a BuchE inhibitory effect of 40% at the final concentration of 100 ㎍/㎖, while the other 50% ethanol extracts showed a BuchE inhibitory effect of around 20%. The 100% Ethanol extract obtained from reflux extraction at 50 ㎍/㎖ showed the highest inhibitory effect on NO generation as 58.3%, whereas the 50% ethanol extract obtained from ASE extraction at 50 ㎍/ ㎖ showed the highest inhibitory effect on ROS generation as 56.0%. Conclusion : The results of the experiments show that the 50% and 100% ethanol extracts prepared under different temperature, pressure and solvent conditions have more effective on strong cholinesterase inhibition, anti-oxidative and anti-inflammatory effects..
        5.
        2015.09 서비스 종료(열람 제한)
        Highly homogeneous and functional stem cell-derived hepatocyte-like cells (HLCs) are considered a promising option in the treatment of liver disease and the development of effective in vitro toxicity screening tool. However, the purity of cells and expression and/or activity of drug metabolizing enzymes in stem cell-derived HLCs are usually too low to be useful for clinical or in vitro applications. Here, we describe a highly optimized differentiation protocol, which produces more than 90% albumin-positive HLCs with no purification process. In addition, we show that hepatic enzyme gene expressions and activities were significantly improved by generating three-dimensional (3D) spheroidal aggregate of HLCs. The 3D differentiation method increased expressions of nuclear receptors that regulate the proper expression of key hepatic enzymes. Furthermore, a significantly increased hepatic functions such as albumin and urea secretion were observed in 3D hepatic spheroids and HLCs in the spheroid exhibited morphological and ultrastructural features of normal hepatocytes. Importantly, we show that repeated exposures to xenobiotics facilitated the functional maturation of HLC, as confirmed by increased expression of genes for drug metabolizing enzymes and transcription factors. In conclusion, the 3D culture system with repeated exposures to xenobiotics may be a new strategy for enhancing hepatic maturation of stem cell-derived HLCs as a cell source for in vitro high-throughput hepatotoxicity models.
        6.
        2015.09 서비스 종료(열람 제한)
        Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells have received extensive attention in the development of drug screening and toxicity testing. However, it has been reported that stem cell-derived HLCs showed hepatic functions that were too limited to be of use in drug screening and toxicity testing, possibly due to the lack of sufficient intercellular communication under conventional two-dimensional (2D) culture conditions. Therefore, a 3D differentiation system may overcome the in vitro limitation of 2D culture to produce stem cell-derived hepatocytes with mature metabolic functions. In this study, the feasibility of using a silicone-based spherofilm, specifically designed to produce spherical cell clusters, to generate uniformly sized 3D hepatic spheroids from hESCs was investigated. Hepatic spheroids generated on the spherofilm showed more homogenous size and shape than those generated in conventional low-attachment suspension culture dishes. Results of immunohistochemical analysis showed that expression of the mature hepatic marker albumin (ALB) increased over time during the hepatic maturation process. Furthermore, the 3D culture system mimicked the in vivo 3D microenvironment. Laminin, which is an important component of hepatic ECM, was expressed in hepatic spheroids. The results of immunohistochemical analysis indicated that the 3D culture environment is capable of generating an in vivo-like microenvironment. In addition, quantitative PCR analysis showed that the mature hepatic marker ALB and cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A7 were expressed at higher levels in 3D culture than in 2D culture. This indicates that the 3D culture system is suitable for hepatic maturation and that our size-controlled 3D culture conditions might accelerate hepatic function. These results suggest that 3D hepatic spheroids significantly enhance metabolic maturation of hepatocytes derived from hESCs