• Title/Summary/Keyword: Barrier

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Study of Heating Temperature and Quantification Conditions of Standard Water for Evaluating Hair Water Content (모발 수분 함량 평가를 위한 가열 온도와 기준 수분 정량 조건 연구)

  • Sang-Hun Song;Jangho Joo;Hyun Sub Park;Seong Kil Son;Nae-Gyu Kang
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.50 no.1
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    • pp.11-18
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    • 2024
  • Recently, there have been attempts to claim the hair moisturizing effect for a hair care product, however there has not yet been an official evaluation method because heating temperature for hair has not been established. This study was conducted to establish a quantitative evaluation for hair water content. In order to observe the behavior of water inside hair, heat was applied to hair with various temperatures using thermogravimetric dry residue. As the heating temperature increased, the amount of moisture released from the hair increased. As a result of evaluating hair using a differential scanning calorimeter (DSC), a unique phenomenon in which a rapid endothermic reaction occurs around 75 ℃ was observed. This phenomenon was also observed in different ethnic hair. In hair that damaged the hair cuticle barrier with oxidation and heat, this rapidly rising endothermic reaction temperature occurred at 77 ℃, which was slightly higher, and 73 ℃ was observed when this hair was applied with polar oil, conditioning polymer, or keratin protein. To determine how this reaction affects the hair surface, friction test was performed using an atomic force microscope. When heated above 75 ℃, cuticle friction increased, however when heated above 90 ℃, there was no change in hair cuticle friction. Finally, it was confirmed that around 75 ℃ is the critical temperature at which desorption of water bound to the hair occurs. It is suggested that a heating temperature of 75 ℃ is the optimal temperature for detecting and quantifying the moisture content of hair, and that approximately 10% detected at 75 ℃ can be a standard value for hair moisture content.

Study on the Efficacy of Paeonia Japonica, Cucurbita Moschata and Prunus Cerasus Complex Extract for Alleviating Stress Associated with Chronic Skin Conditions (만성 피부 질환으로 발생하는 스트레스 개선을 위한 호박, 작약, 타트체리 복합물의 효능 연구)

  • Su-Jin Park;Dong-Hee Kim;Ki-Sung Kwak;Hyun-Jeong Kim
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.2
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    • pp.459-471
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    • 2024
  • In modern society, where tension and stress are ubiquitous, individuals often experience psychological imbalances. These stressors not only affect mental well-being but also manifest physically, through the skin. Consequently, a new term psychodermatology combining psychiatry and dermatology, has emerged, garnerning attention and research focus. In this study, we aimed to develop materials improving chronic skin conditions caused by stress by utilizing a compound of Cucurbita moschata, Paeonia japonica, and Prunus cerasus known to alleviate skin disorders. We sought to develop and validate the efficacy of materials alleviating chronic skin conditions induced by stress in keratinocytes..Therefore, in this study we analyzed the effects of a complex extract using Cucurbita moschata, Paeonia japonica, and Prunus cerasus on HaCaT keratinocyte cells to understand how it influences them. The complex extract on HaCaT keratinocyte cells showed a concentration-dependent decrease in the expression levels of TNF-α, IL-1β, IL-6, MDC, and TARC at concentrations of 12.5, 25, 50 and 100 ㎍/mL. Particularly noteworthy was the efficacy observed in inhibiting IL-1β, with a reduction of over 40% at a concentration of 100 ㎍/mL. Additionally, the production levels of AQP-3, HA, and filaggrin exhibited a significant concentration-dependent increase. The protein expression of p-ERK, p-JNK, and p-p38, which were elevated by TNF-α/IFN-γ, was significantly decreased with the treatment of the complex extract. These findings suggest that the compound extract may be utilized as a material for treating and preventing skin conditions, potentially mitigating the adverse effects of the mutual relationship between skin disorders and stress.

The Effect of Treadmill Exercise and Environmental Enrichment on Cognitive Function, Muscle Function, and Levels of tight junction protein in an Alzheimer's Disease Animal Model (트레드밀 운동 및 환경강화가 알츠하이머 질환 동물 모델의 인지기능, 근 기능 및 밀착연접 단백질 수준에 미치는 영향)

  • Hyun-Seob Um;Jong-Hwan Jung;Tae-Kyung Kim;Yoo-Joung Jeon;Joon-Yong Cho;Jung-Hoon Koo
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.1
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    • pp.58-68
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    • 2024
  • The purpose of this study was to investigate the effects of treadmill exercise treadmill exercise (TE) and environmental enrichment (EE) interventions on cognitive function, muscle function, and the expression of tight junction proteins in an Alzheimer's disease (AD) animal model. To create the AD animal model, aluminum chloride (AlCl3) was administered for 90 days (40mg/kg/day), while simultaneously exposing the animals to TE (10-12m/min, 40-60min/day) or EE. The results showed that cognitive impairment and muscle dysfunction induced by AlCl3 administration were alleviated by TE and EE. Furthermore, TE and EE reduced the increased expression of β-amyloid(Aβ), alpha-synuclein, and tumor necrosis factor-α (TNF-α) proteins observed in AD pathology. Additionally, TE and EE significantly increased the expression of decreased adhesive adjacent proteins (Occludin, Claudin-5, and ZO-1) induced by AlCl3 administration. Lastly, correlation analysis between Aβ protein and tight junction proteins showed negative correlations (Occludin: r=-0.853, p=0.001; Claudin-5: r=-0.352, p=0.915; ZO-1: r=-0.424, p=0.0390). In conclusion, TE or EE interventions are considered effective exercise methods that partially alleviate pathological features of AD, improving cognitive and muscle function.

Review of In-situ Installation of Buffer and Backfill and Their Water Saturation Management for a Deep Geological Disposal System of Spent Nuclear Fuel (국외 사례를 통한 사용후핵연료 심층처분시스템 완충재 및 뒤채움재의 현장시공 및 포화도 관리 기술 분석)

  • Ju-Won Yun;Won-Jin Cho;Hyung-Mok Kim
    • Tunnel and Underground Space
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    • v.34 no.2
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    • pp.104-126
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    • 2024
  • Buffer and backfill play an essential role in isolating high-level radioactive waste and retard the migration of leaked radionuclides in deep geological disposal system. A bentonite mixture, which exhibits a swelling property, is considered for buffer and backfill materials, and excessive groundwater inflow from surrounding rock mass may affect stability and efficiency of their role as an engineered barrier. Therefore, stringent quality control as well as in-situ installation management and inflow water constrol for buffer and backfill are required to ensure the safety of deep disposal facilities. In this study, we analyzed the design requirements of buffer and backfill by examining various laboratory tests and a field study of the Steel Tunnel Test at the Äspö Hard Rock Laboratory in Sweden. We introduced how to control the quality of buffer and backfill construction in-field, and also presented how to handle excessive groundwater inflow into disposal caverns, validating the groundwater retention capacity of bentonite pellets and the effectiveness of geotexile use.

Butyric acid and prospects for creation of new medicines based on its derivatives: a literature review

  • Lyudmila K. Gerunova;Taras V. Gerunov;Lydia G. P'yanova;Alexander V. Lavrenov;Anna V. Sedanova;Maria S. Delyagina;Yuri N. Fedorov;Natalia V. Kornienko;Yana O. Kryuchek;Anna A. Tarasenko
    • Journal of Veterinary Science
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    • v.25 no.2
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    • pp.23.1-23.15
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    • 2024
  • The widespread use of antimicrobials causes antibiotic resistance in bacteria. The use of butyric acid and its derivatives is an alternative tactic. This review summarizes the literature on the role of butyric acid in the body and provides further prospects for the clinical use of its derivatives and delivery methods to the animal body. Thus far, there is evidence confirming the vital role of butyric acid in the body and the effectiveness of its derivatives when used as animal medicines and growth stimulants. Butyric acid salts stimulate immunomodulatory activity by reducing microbial colonization of the intestine and suppressing inflammation. Extraintestinal effects occur against the background of hemoglobinopathy, hypercholesterolemia, insulin resistance, and cerebral ischemia. Butyric acid derivatives inhibit histone deacetylase. Aberrant histone deacetylase activity is associated with the development of certain types of cancer in humans. Feed additives containing butyric acid salts or tributyrin are used widely in animal husbandry. They improve the functional status of the intestine and accelerate animal growth and development. On the other hand, high concentrations of butyric acid stimulate the apoptosis of epithelial cells and disrupt the intestinal barrier function. This review highlights the biological activity and the mechanism of action of butyric acid, its salts, and esters, revealing their role in the treatment of various animal and human diseases. This paper also discussed the possibility of using butyric acid and its derivatives as surface modifiers of enterosorbents to obtain new drugs with bifunctional action.

Seasonal variation in longitudinal connectivity for fish community in the Hotancheon from the Geum River, as assessed by environmental DNA metabarcoding

  • Hyuk Je Lee;Yu Rim Kim;Hee-kyu Choi;Seo Yeon Byeon;Soon Young Hwang;Kwang-Guk An;Seo Jin Ki;Dae-Yeul Bae
    • Journal of Ecology and Environment
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    • v.48 no.1
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    • pp.32-48
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    • 2024
  • Background: Longitudinal connectivity in river systems strongly affects biological components related to ecosystem functioning, thereby playing an important role in shaping local biodiversity and ecosystem health. Environmental DNA (eDNA)-based metabarcoding has an advantage of enabling to sensitively diagnose the presence/absence of species, becoming an efficient/effective approach for studying the community structure of ecosystems. However, little attention has been paid to eDNA-based biomonitoring for river systems, particularly for assessing the river longitudinal connectivity. In this study, by using eDNA we analyzed and compared species diversity and composition among artificial barriers to assess the longitudinal connectivity of the fish community along down-, mid- and upstream in the Hotancheon from the Geum River basin. Moreover, we investigated temporal variation in eDNA fish community structure and species diversity according to season. Results: The results of species detected between eDNA and conventional surveys revealed higher sensitivity for eDNA and 61% of species (23/38) detected in both methods. The results showed that eDNA-based fish community structure differs from down-, mid- and upstream, and species diversity decreased from down to upstream regardless of season. We found that there was generally higher species diversity at the study sites in spring (a total number of species across the sites [n] = 29) than in autumn (n = 27). Nonmetric multidimensional scaling and heatmap analyses further suggest that there was a tendency for community clusters to form in the down-, mid- and upstream, and seasonal variation in the community structure also existed for the sites. Dominant species in the Hotancheon was Rhynchocypris oxycephalus (26.07%) regardless of season, and subdominant species was Nipponocypris koreanus (16.50%) in spring and Odontobutis platycephala (15.73%) in autumn. Artificial barriers appeared to negatively affect the connectivity of some fish species of high mobility. Conclusions: This study attempts to establish a biological monitoring system by highlighting the versatility and power of eDNA metabarcoding in monitoring native fish community and further evaluating the longitudinal connectivity of river ecosystems. The results of this study suggest that eDNA can be applied to identify fish community structure and species diversity in river systems, although some shortcomings remain still need to be resolved.

Christian Religious Education's Enchanting Duty : A Curriculum of Hope from the Underside of Civic Polarization, Moral Disimagination, and Learned Helplessness (책임을 노래하는 기독교적 종교교육 : 시민적 양극성, 도덕적 무감각, 학습된 무력감의 저변에서 시작된 희망의 교육과정)

  • Le Tran Mai Anh
    • Journal of Christian Education in Korea
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    • v.77
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    • pp.7-27
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    • 2024
  • This study addresses the crucial role of Christian Religious Education (CRE) amidst civic polarization, moral disimagination, and learned helplessness. It begins her personal background as a 1.5-generation Vietnamese American and her academic engagement in immigrant faith and the challenges of teaching faith in violent contexts. The work underscores the public dimension and impact of religious education, highlighting its potential for fostering critical capacities for public engagement. However, that study observes a prevalent disconnection between congregational culture and the aim of public engagement, leading to a form of learned helplessness among students and communities. The researcher draws on Paulo Freire's concepts of "critical hope" and the need for a curriculum that transcends mere content delivery to foster transformative engagement with societal issues. The document critiques the disimigination machine that undermines critical thinking and collective resistance, as articulated by Henry Giroux, and explores the concepts of "learned helplessness" as a barrier to environmental and social activism. The researcher advocates for a theopoetic and theopolitical approach to education that nurtures hope and practical engagement with the world's injustice. She emphasizes small acts of theopoetic and theopolitical hope as transformative practices, using an example from Ferguson, Missouri, to illustrate how public liturgy and protest can mediate hope and justice. The document concludes with a call for a life-long, life-wide, and life-deep curriculum of enchantment towards responsible participation in societal repair, rooted in Christian hope.

Suppression of Glioblastoma Stem Cell Potency and Tumor Growth via LRRK2 Inhibition

  • Saewhan Park;Kyung-Hee Kim;Yun-Hee Bae;Young Taek Oh;Hyemi Shin;Hyung Joon Kwon;Chan Il Kim;Sung Soo Kim;Hwan-Geun Choi;Jong Bae Park;Byoung Dae Lee
    • International Journal of Stem Cells
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    • v.17 no.3
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    • pp.319-329
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    • 2024
  • Leucine-rich repeat kinase 2 (LRRK2), a large GTP-regulated serine/threonine kinase, is well-known for its mutations causing late-onset Parkinson's disease. However, the role of LRRK2 in glioblastoma (GBM) carcinogenesis has not yet been fully elucidated. Here, we discovered that LRRK2 was overexpressed in 40% of GBM patients, according to tissue microarray analysis, and high LRRK2 expression correlated with poor prognosis in GBM patients. LRRK2 and stemness factors were highly expressed in various patient-derived GBM stem cells, which are responsible for GBM initiation. Canonical serum-induced differentiation decreased the expression of both LRRK2 and stemness factors. Given that LRRK2 is a key regulator of glioma stem cell (GSC) stemness, we developed DNK72, a novel LRRK2 kinase inhibitor that penetrates the blood-brain barrier. DNK72 binds to the phosphorylation sites of active LRRK2 and dramatically reduced cell proliferation and stemness factors expression in in vitro studies. Orthotopic patient-derived xenograft mouse models demonstrated that LRRK2 inhibition with DNK72 effectively reduced tumor growth and increased survival time. We propose that LRRK2 plays a significant role in regulating the stemness of GSCs and that suppression of LRRK2 kinase activity leads to reduced GBM malignancy and proliferation. In the near future, targeting LRRK2 in patients with high LRRK2-expressing GBM could offer a superior therapeutic strategy and potentially replace current clinical treatment methods.

Study on the Anti-Aging Activity of Chrysanthemum lucidum Exosomes (울릉국화 엑소좀의 항노화 활성 효과 연구)

  • Min-Ha Kim;Eun Jung Yoon;Jung Soo Kim;So Hyun Bae;Na Young Choi;Si Jun Park;Hyun Sang Lee
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.50 no.3
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    • pp.289-299
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    • 2024
  • Chrysanthemum lucidum (C. lucidum), a perennial herb in the Asteraceae family, is an endemic species found only on Ulleung island in Gyeongsangbuk-do, South Korea. Previous studies have reported that the extract of C. lucidum exhibits excellent antioxidant activity due to its high polyphenol and flavonoid content. However, the anti-aging effects of C. lucidum extract, such as wrinkle improvement and cell regeneration, are not well known, and there has been no research on the activity of C. lucidum-derived extracellular vesicles (ClDEVs). Therefore, this study aimed to verify the anti-aging effects of ClDEVs through in vitro and clinical analyses. In cell experiments, ClDEVs promoted cell regeneration, increased the expression of COL1A1, a gene involved in collagen synthesis, and enhanced the expression of FLG and LOR, a biomarker related to skin barrier improvement. Additionally, ClDEVs suppressed the expression of aging-related biomarkers, such as the CDKN2A (encodes p16) and TP53 (encodes p53) genes, in cells induced to age. In a human clinical trial, after using a cosmetic product containing ClDEVs for 4 weeks, significant improvement in wrinkles around the eyes and nasolabial folds was observed. In conclusion, ClDEVs have demonstrated high potential as a bio-cosmetic ingredient for wrinkle improvement and anti-aging.

Optimization of the P+ Region in SiC-Based MPS Diodes: Enhancing BFOM and Alleviating Snap-Back Phenomenon (SiC 기반 MPS 다이오드 P+ 영역 최적화: BFOM 향상과 Snap-Back 현상 완화를 위한 연구)

  • Seung-Hyun Park;Tae-Hee Lee;Se-Rim Park;Ju-Eun Yun;Geon-Hee Lee;Ji-Hwan Jeon;Jong-Min Oh;Weon Ho Shin;Sang-Mo Koo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.6
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    • pp.675-679
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    • 2024
  • Wide bandgap (WBG) devices, especially SiC, are gaining traction as materials for high-power EV conversion devices due to their superior efficiency and switching capabilities compared to Si-based power devices. SiC allows for high power, high temperature, and high frequency applications because of its outstanding thermal conductivity, saturation velocity, and dielectric breakdown field. SiC-based MPS diodes combine the advantages of SiC-based SBDs and PiN diodes, allowing high-frequency switching operation with low leakage currents under high voltage conditions. However, MPS diodes exhibit snapback phenomena influenced by the P+ region's size, necessitating optimization. A TCAD simulation studied the impact of the P+ region's depth and width on MPS diode performance. Increasing the P+ width raised the On-specific resistance (Ron,sp) and lowered the maximum voltage during snapback (Vsnap). Increasing the depth decreased both Breakdown voltage (BV) and Vsnap. A trade-off between the semiconductor performance index BFOM and Vsnap was identified, leading to optimized dimensions. The optimized MPS diode shows a low Vsnap of about 3.89 V and a high BFOM of 1.72 GW·cm2, highlighting its potential as a next-generation high-performance power conversion device.