• Title/Summary/Keyword: effective strength

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Combination of red ginseng and velvet antler extracts prevents skin damage by enhancing the antioxidant defense system and inhibiting MAPK/AP-1/NF-κB and caspase signaling pathways in UVB-irradiated HaCaT keratinocytes and SKH-1 hairless mice

  • Van-Long Truong;Yeon-Ji Bae;Ji-Hong Bang;Woo-Sik Jeong
    • Journal of Ginseng Research
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    • v.48 no.3
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    • pp.323-332
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    • 2024
  • Background: Studies have reported that the combination of two or more therapeutic compounds at certain ratios has more noticeable pharmaceutical properties than single compounds and requires reduced dosage of each agent. Red ginseng and velvet antler have been extensively used in boosting immunity and physical strength and preventing diseases. Thus, this study was conducted to elucidate the skin-protective potentials of red ginseng extract (RGE) and velvet antler extract (VAE) alone or in combination on ultraviolet (UVB)-irradiated human keratinocytes and SKH-1 hairless mice. Methods: HaCaT cells were preincubated with RGE/VAE alone or in combination for 2 h before UVB (30 mJ/cm2) irradiation. SKH-1 mice were orally given RGE/VAE alone or in combination for 15 days before exposure to single dose of UVB (600 mJ/cm2). Treated cells and treated skin tissues were collected and subjected to subsequent experiments. Results: RGE/VAE pretreatment alone or in combination significantly prevented UVB-induced cell death, apoptosis, reactive oxygen species production, and DNA damage in keratinocytes and SKH-1 mouse skins by downregulating mitogen-activated protein kinases/activator protein 1/nuclear factor kappa B and caspase signaling pathways. These extracts also strengthened the antioxidant defense systems and skin barriers in UVB-irradiated HaCaT cells and SKH-1 mouse skins. Furthermore, RGE/VAE co-administration appeared to be more effective in preventing UVB-caused skin injury than these extracts used alone. Conclusion: Overall, these findings suggest that the consumption of RGE/VAE, especially in combination, offers a protective ability against UVB-caused skin injury by preventing inflammation and apoptosis and enhancing antioxidant capacity.

A Study on the Subjective Perception Types of the Competencies Required of Airline Cabin Crew Members (항공사 객실승무원에게 요구되는 역량에 대한 객실승무원들의 주관적 인식 유형 연구)

  • Hye Jung Park;Hyun Been Park;Yeon Sook Lee
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.257-266
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    • 2024
  • This study analyzed the characteristics of each type of subjective perception of cabin crew by applying Q-methodology to understand the competencies required of airline cabin crew. As a result of analyzing 33 Q-samples and 33 P-samples using the Ken-Q Analysis program, four types were identified: "Physical strength and appearance quality-oriented", "job performance-oriented", "communication ability-oriented", and "job consciousness-oriented". Most types showed high agreement on physical factors, ability to cope with emergency situations and work responsibility. The results can be used as basic data to develop effective curriculum for airline training course and airline service majors, and it can be a reference material to help job seekers understand the job and cultivate necessary competencies.

Heart rate recovery as a critical determinant in weightlifting (역도선수의 경기력 결정요인으로서 심박수 회복에 관한 연구)

  • Dong-Joo Hwang;Jung-Hoon Koo;Tae-Kyung Kim;Yong-Chul Jang;Joon-Yong Cho
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.6
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    • pp.1340-1349
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    • 2023
  • Despite its profound impact on athletic performance, the significance of heart rate recovery (HRR) has been insufficiently addressed in the filed of sports science, particularly in the context of weightlifting characterized by brief and intense exertions involving heavy weights. Serving as a valuable indicator of autonomic nervous system and cardiovascular function, HRR assumes a pivotal role in weightlifting. This comprehensive review aims to delineate the specific demands for HRR in weightlifting, shedding light on the often overlooked cardiovascular considerations within training regimes focused on strength and power. The investigation scrutinizes the repercussions of HRR on weightlifting performance, seeking to elucidate how inadequate recovery intervals may result in physiological and psychological consequences. These consequences encompass a distorted perception of effort, disruption of coordination, compromised posture due to irregular breathing, and an overall decline in lifting capacity. The review systematically presents compelling evidence pertaining to heart rate response and recovery patterns during weightlifting, underscoring the critical importance of well-structured rest periods. Furthermore, the review delves into a comprehensive discussion of factors influencing HRR in weightlifting, encompassing variables such as sex, age, cardiovascular function, hydration, nutrition, and psychological aspects. Finally, a key emphasis is placed on the integration of effective HRR techniques into the training regimens of weightlifters, thereby ensuring sustained and optimized performance outcomes.

Experimental study on solidification of uranium tailings by microbial grouting combined with electroosmosis

  • Jinxiang Deng;Mengjie Li;Yakun Tian;Lingling Wu;Lin Hu;Zhijun Zhang;Huaimiao Zheng
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4527-4542
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    • 2023
  • The present microbial reinforcement of rock and soil exhibits limitations, such as uneven reinforcement effectiveness and low calcium carbonate generation rate, resulting in limited solidification strength. This study introduces electroosmosis as a standard microbial grouting reinforcement technique and investigates its solidification effects on microbial-reinforced uranium tailings. The most effective electroosmosis effect on uranium tailings occurs under a potential gradient of 1.25 V/cm. The findings indicate that a weak electric field can effectively promote microbial growth and biological activity and accelerate bacterial metabolism. The largest calcium carbonate production occurred under the gradient of 0.5 V/cm, featuring a good crystal combination and the best cementation effect. Staged electroosmosis and electrode conversion efficiently drive the migration of anions and cations. Under electroosmosis, the cohesion of uranium tailings reinforced by microorganisms increased by 37.3% and 64.8% compared to those reinforced by common microorganisms and undisturbed uranium tailings, respectively. The internal friction angle is also improved, significantly enhancing the uniformity of reinforcement and a denser and stronger microscopic structure. This research demonstrates that MICP technology enhances the solidification effects and uniformity of uranium tailings, providing a novel approach to maintaining the safety and stability of uranium tailings dams.

Bond Characteristics of FRP sheet to Various Types under Cyclic Load (반복하중하의 FRP 시트 종류에 따른 부착특성)

  • Ko, Hune Bum
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.2
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    • pp.131-138
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    • 2008
  • Fiber-reinforced polymer (FRP) sheets have been successfully used to retrofit a number of existing concrete buildings and structures because of their excellent properties (high strength, light weight and high durability). Bond characteristics between FRP sheets and concrete should be investigated to ensure an effective retrofitting system. RC structures strengthened with FRP sheets are often subjected to cyclic load (traffic, seismic, temperature, etc.). This research addresses a local bond stress-slip relationship under cyclic loading conditions for the FRP-concrete interface. 18 specimens were prepared with three types of FRP sheets (aramid, carbon, and polyacetal) and two types of sheet layer(one or two). The characteristics of bond stress-slip were verified through experimental results on load-displacement relationship.

Development of monitoring system to prevent inflow of marine life into the nuclear power plant (해양생물의 원전 취수구 유입 방지를 위한 모니터링 시스템 개발)

  • Tae-Jong KANG;Eun-Bi MIN;Joong-Ro SHIN;Doo-Jin HWANG
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.60 no.3
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    • pp.277-289
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    • 2024
  • Climate change has led to a significant increase in jellyfish populations globally, causing various problems. For power plants that use nearby seawater for cooling, the intrusion of jellyfish into intake systems can block the flow, leading to reduced output or even shutdowns. This issue is compounded by other small marine organisms like shrimp and salps, making it urgent to develop solutions to prevent their intrusion. This study addressed the problem using the BioSonics DT-X 120 kHz scientific fish finder to conduct preliminary tank experiments. We also deployed underwater acoustic and camera buoys around the intake of nuclear power plant, utilizing a bidirectional communication system between sea and land to collect data. Data collection took place from July 31, 2023 to August 1, 2023. While harmful organisms such as jellyfish and salps were not detected, we successfully gathered acoustic data on small fish measuring backscattering strength (SV). Analysis showed that fish schools were more prominent in the evening than during the day. The highest fish distribution was observed at 3:30 AM on July 31 with an SV of -44.8 dB while the lowest was at 12:30 PM on the same day with an SV of -63.4 dB. Additionally, a solar-powered system was used to enable real-time data acquisition from sea buoys with smooth communication between the land server and the offshore buoy located 1.8 km away. This research developed an acoustic-based monitoring system for detecting harmful organisms around the intake and provided foundational data for preventing marine organism intrusion and planning effective measures.

Preliminary Study on Black-Ice Detection Using GPS Ground Reflection Signals

  • Young-Joo Kwon;Hyun-Ju Ban;Sumin Ryu;Suna Jo;Han-Sol Ryu;Yerin Kim;Yun-Jeong Choi;Sungwook Hong
    • Journal of the Korean earth science society
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    • v.45 no.4
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    • pp.318-326
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    • 2024
  • Black ice, a thin and nearly invisible ice layer on roads and pavements, poses a significant danger to drivers and pedestrians during winter due to its transparency. We propose an efficient black ice detection system and technique utilizing Global Positioning System (GPS)-reflected signals. This system consists of a GPS antenna and receiver configured to measure the power of GPS L1 band signal strength. The GPS receiver system was designed to measure the signal power of the Right-Handed Circular Polarization (RHCP) and Left-Handed Circular Polarization (LHCP) from direct and reflected signals using two GPS antennas. Field experiments for GPS LHCP and RHCP reflection measurements were conducted at two distinct sites. We present a Normalized Polarized Reflection Index (NPRI) as a methodological approach for determining the presence of black ice on road surfaces. The field experiments at both sites successfully detected black ice on asphalt roads, indicated by NPRI values greater than -0.1 for elevation angles between 45° and 55°. Our findings demonstrate the potential of the proposed GPS-based system as a cost-effective and scalable solution for large-scale black ice detection, significantly enhancing road safety in cold climates. The scientific significance of this study lies in its novel application of GPS reflection signals for environmental monitoring, offering a new approach that can be integrated into existing GPS infrastructure to detect widespread black ice in real-time.

Evidence-based Clinical Guidelines for Optimizing the Use of Standing Frame: A Systematic Review of Dosing Recommendations Among Cerebral Palsy

  • Changho Kim;Hyunsuk Park
    • Physical Therapy Korea
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    • v.31 no.2
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    • pp.131-141
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    • 2024
  • Background: Standing frames are a common intervention for children with cerebral palsy (CP), yet there is a lack of standardized dosing recommendations, impeding the enhancement of treatment outcomes in this population. Objects: This paper aims to optimize dosing strategies for standing frame programs in children with CP. It evaluates effective durations and frequencies for using standing frames to improve gait, hip joint integrity, functional activities, joint range of motion, and muscle tone. The goal is to provide evidence-based clinical recommendations to guide practitioners in treating pediatric CP patients. Methods: A comprehensive research was conducted across seven databases, yielding 23 studies meeting inclusion criteria. Strength of evidence was assessed using established tools. Clinical recommendations were formulated based on the amalgamation of existing evidence. Results: The paucity of evidence-based dosing recommendations for children with CP supported standing device is highlighted in this review. Key findings suggest that standing frames implemented 5 days per week demonstrate positive effects on gait (45 minutes/day, 3 times/week), hip joint integrity (60 minutes/day), functional activities (60 minutes/day in 30° to 60° of bilateral hip abduction), joint range of motion (60 minutes/day), and muscle tone (30 minutes/day). Conclusion: This systematic review of the treatment regimens for children with CP is providing useful insights to the dosing strategies of standing frames. The evidence supports a 30-60 minutes per day and 3-5 days a week intervention with specified durations for optimal outcomes. In enhancing the effectiveness of standing frames, as well as promoting evidence-based practices in the management of children with CP, these clinical recommendations offer guidance for practitioners.

Micropropagation of Lobelia chinensis Lour.: Influence of Medium Parameters on Plant Regeneration, Antioxidant Activity, and Secondary Metabolite Accumulation

  • Xinlei Bai;Han-Sol Lee;Hosakatte Niranjana Murthy;Hyuk-Joon Kwon;Soo-Ho Yeon;Jae-Yeong Ju;So-Young Park
    • Korean Journal of Plant Resources
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    • v.37 no.3
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    • pp.225-234
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    • 2024
  • Chinese lobelia (Lobelia chinensis Lour.) is an important medicinal plant that is used in traditional Chinese, Korean, and Japanese medicine. The goal of the current study was to develop an in vitro propagation technique for Lobelia chinensis. We have examined the effects of different media compositions on the regeneration of shoots from nodal cultures of Lobelia chinensis, including Murashige and Skoog (MS), Gamborg (B5), Schenk and Hildebrandt (SH), Woody plant (WPM), Chu (N6), and Nitsch and Nitsch (NLN) media. Similar to this, shoot regeneration was examined using MS medium of double (2.0), full (1.0), half (0.5), and quarter (0.25) strengths. The regeneration of shoots was also examined with additions of 0, 1, 3, 5, and 7% (w/v) sucrose to MS media. For axillary shoot regeneration, full-strength MS medium supplemented with 3% (w/v) sucrose was shown to be the most effective of all the evaluated factors. On this medium, nodal explants optimally regenerated 4.5 shoots per explant and subsequently shoots involved in rooting on the same medium. The regenerated plants possessed abundant phenolics, flavonoids, and DPPH, ABTS, and FRAP antioxidant activities. High performance liquid chromatographic examination (HPLC) of the regenerated plants revealed an accumulation of myricetin and catechin in higher amounts.

Comparing the Effects of Hip Exercises versus Ankle Stabilization Exercises in Subjects with Chronic Ankle Instability (만성 발목 불안정 대상자에 대한 엉덩이근육운동과 발목안정화운동의 효과 비교)

  • Jin-Seok Han;Seung-Chul Chon
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.3
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    • pp.49-59
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    • 2024
  • Purpose : Chronic ankle instability (CAI) can impair strength and balance, leading to activity limitations and restricted participation. Traditionally, ankle stabilization exercises have been applied, and more recently, the effects of hip muscle exercises have been studied. The purpose of this study was to determine the immediate effects of hip exercises (HE) and ankle stabilization exercises (ASE) on dynamic balance, performance and ankle function in subjects with CAI. We also compared the difference in effectiveness between HE and ASE. Methods : A total of 34 subjects with CAI participated, ane were randomly divided into two groups: the HE group and the ASE group. The HE group performed a program consisting of exercises above 70 % MVIC, while the ASE group performed a traditional ankle stabilization exercise program. The subjects in each group completed their respective exercise program for a total of 30 minutes once a day and were assessed before and after the intervention. Dynamic balance was assessed using the Y-balance test (YBT). Performance was assessed using the hop for distance test (HDT), and side-hop test (SHT). Ankle function was assessed using foot and ankle ability measure (FAAM) questionnaires. Results : YBT, HDT, and FAAM values increased significantly in both groups after the intervention (p<.05), and there was no significant difference between the groups. SHT values decreased significantly in both groups after the intervention (p<.05), and there was no significant difference between the groups. Conclusion : Although no significant superiority was observed between HE and ASE in this study, both exercise programs were effective in improving dynamic balance, performance, and ankle function in subjects with CAI. These findings suggest that both HE and ASE can be suitable interventions for CAI, highlighting the need for individualized treatment plans. Future research is warranted to explore the long-term effects of exercise programs on CAI subjects of different ages and occupational characteristics.