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Review on Rock-Mechanical Models and Numerical Analyses for the Evaluation on Mechanical Stability of Rockmass as a Natural Barriar (천연방벽 장기 안정성 평가를 위한 암반역학적 모델 고찰 및 수치해석 검토)

  • Myung Kyu Song;Tae Young Ko;Sean S. W., Lee;Kunchai Lee;Byungchan Kim;Jaehoon Jung;Yongjin Shin
    • Tunnel and Underground Space
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    • v.33 no.6
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    • pp.445-471
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    • 2023
  • Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.

Synthesis of Pressure-sensitive Acrylic Adhesives with Photoreactive Groups and Their Application to Semiconductor Dicing Tapes (광 반응성기를 갖는 아크릴 점착제의 합성과 반도체 다이싱 테이프로의 적용 연구)

  • Hee-Woong Park;Nam-Gyu Jang;Kiok Kwon;Seunghan Shin
    • Applied Chemistry for Engineering
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    • v.34 no.5
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    • pp.522-528
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    • 2023
  • In this work, adhesive tapes were prepared for the dicing process in semiconductor manufacturing. Compounds with different numbers of photoreactive groups (f = 1 to 3) were synthesized and incorporated into acrylic copolymers to formulate UV-curable acrylic adhesives. Structural confirmation of the synthesized photoreactive compounds (f = 2 or 3) was performed using nuclear magnetic resonance (NMR) spectroscopy. The introduction of the photoreactive compounds into the acrylic adhesive was accomplished by urethane reactions, and the successful synthesis of the UV-curable acrylic adhesive was verified by Fourier transform infrared (FT-IR) measurements. To evaluate the performance of the adhesive, the peel strength was evaluated before and after UV irradiation using a silicon wafer as a substrate. The adhesive exhibited high peel strength (~2000 gf/25 mm) before UV exposure, which was significantly reduced (~5 gf/25 mm) after UV exposure. Interestingly, the adhesive containing multifunctional photoreactive compounds showed the most significant reduction in peel strength. In addition, surface residue measurements by field emission scanning electron microscopy (FE-SEM) showed minimal surface residue (~0.2%) after UV exposure. Overall, these results contribute to the understanding of the behavior of UV-curable acrylic adhesives and pave the way for potential applications in semiconductor manufacturing processes.

The TGFβ→TAK1→LATS→YAP1 Pathway Regulates the Spatiotemporal Dynamics of YAP1

  • Min-Kyu Kim;Sang-Hyun Han;Tae-Geun Park;Soo-Hyun Song;Ja-Youl Lee;You-Soub Lee;Seo-Yeong Yoo;Xin-Zi Chi;Eung-Gook Kim;Ju-Won Jang;Dae Sik Lim;Andre J. van Wijnen;Jung-Won Lee;Suk-Chul Bae
    • Molecules and Cells
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    • v.46 no.10
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    • pp.592-610
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    • 2023
  • The Hippo kinase cascade functions as a central hub that relays input from the "outside world" of the cell and translates it into specific cellular responses by regulating the activity of Yes-associated protein 1 (YAP1). How Hippo translates input from the extracellular signals into specific intracellular responses remains unclear. Here, we show that transforming growth factor β (TGFβ)-activated TAK1 activates LATS1/2, which then phosphorylates YAP1. Phosphorylated YAP1 (p-YAP1) associates with RUNX3, but not with TEAD4, to form a TGFβ-stimulated restriction (R)-point-associated complex which activates target chromatin loci in the nucleus. Soon after, p-YAP1 is exported to the cytoplasm. Attenuation of TGFβ signaling results in re-localization of unphosphorylated YAP1 to the nucleus, where it forms a YAP1/TEAD4/SMAD3/AP1/p300 complex. The TGFβ-stimulated spatiotemporal dynamics of YAP1 are abrogated in many cancer cells. These results identify a new pathway that integrates TGFβ signals and the Hippo pathway (TGFβ→TAK1→LATS1/2→YAP1 cascade) with a novel dynamic nuclear role for p-YAP1.

Effects of stocking density on the homeostasis of uric acid and related liver and kidney functions in ducks

  • Peiyi Lin;Sui Liufu;Jinhui Wang;Zhanpeng Hou;Yu Liang;Haiyue Wang;Bingxin Li;Nan Cao;Wenjun Liu;Yunmao Huang;Yunbo Tian;Danning Xu;Xiujin Li;Xinliang Fu
    • Animal Bioscience
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    • v.37 no.5
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    • pp.952-961
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    • 2024
  • Objective: Stocking density (SD) is an important issue in the poultry industry, which is related to the production performance, intestinal health and immune status. In the present study, the effects of SD on the metabolism and homeostasis of uric acid as well as the related functions of the liver and kidney in ducks were examined. Methods: A total of 360 healthy 56-day-old Shan-ma ducks were randomly divided into the low stocking density (n = 60, density = 5 birds/m2), medium stocking density (n = 120, density = 10 birds/m2) and high stocking density groups (HSD; n = 180, density = 15 birds/m2). Samples were collected in the 3rd, 6th, and 9th weeks of the experiment for analysis. Results: The serum levels of uric acid, lipopolysaccharide and inflammatory cytokines (interleukin-1β [IL-1β], IL-8, and tumor necrosis factor-α [TNF-α]) were increased significantly in the HSD group. Serious histopathological lesions could be seen in both the livers and kidneys in the HSD group in the 9th week. The mRNA expression levels of inflammatory cytokines (IL-8 and TNF-α) and related pathway components (toll-like receptor 4, myeloid differentiation primary response gene 88, and nuclear factor-κB) were increased significantly in both the livers and kidneys in the HSD group. The mRNA expression levels of enzymes (adenosine deaminase, xanthine oxidase, phosphoribosyl pyrophosphate amidotransferase, and phosphoribosyl pyrophosphate synthetase 1) related to the synthesis of uric acid increased significantly in the livers in the HSD group. However, the mRNA expression level of solute carrier family 2 member 9, which plays an important role in the excretion of uric acid by the kidney, was decreased significantly in the kidneys in the HSD group. Conclusion: These results indicated that a higher SD could cause tissue inflammatory lesions in the liver and kidney and subsequently affect the metabolism and homeostasis of uric acid, and is helpful for guiding decisions related to the breeding and production of ducks.

Ameliorative Effect of Persicaria Poliata Etract through the Rgulation of AP-1, PI3K/Akt and MAPK Sgnaling Mlecules in UVB-Iradiated HaCaT Clls (HaCaT 세포에서 며느리 배꼽 추출물의 AP-1, PI3K/Akt 및 MAPK 활성 조절을 통한 광손상 억제 효과)

  • Hyun-Seo Yoon;Chung-Mu Park
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.1
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    • pp.63-71
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    • 2024
  • Purpose : Skin is the primary barrier to protect the body from various exogenous factors. Among them, UVB exposure can cause the induction of not only excessive inflammatory responses but also the degradation of extracellular matrix (ECM), including collagen and elastin. This study tried to investigate the ameliorative effect of Persicaria perfoliata ethanol extract (PPEE) on UVB-irradiated photodamage through the regulation of activator protein (AP)-1, phosphoinositide 3-kinase (PI3K)/Akt, and mitogen-activated protein kinase (MAPK) signaling molecules in HaCaT cells. Methods : The cytotoxicity of PPEE on HaCaT cells was evaluated by the WST-1 assay. The 80 mJ/cm2 of UVB (312 nm) was irradiated on HaCaT cells to induce the photodamage. Western blot analysis was conducted to investigate the protein expression levels of cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-9, and heme oxygenase (HO)-1 for ameliorative status by PPEE treatment in UVB-exposed HaCaT cells. In addition, the activated status of the inflammatory transcription factor, AP-1, as well as upstream signaling molecules, PI3K/Akt, and MAPK, were also evaluated by Western blot analysis. Results : Any cytotoxic effect was not induced at the concentration up to 200 ㎍/ml by PPEE treatment. Protein expression levels of COX-2 and MMP-9 were significantly down- and up-regulated by PPEE treatment. The inflammatory transcription factor AP-1, stimulated by UVB irradiation, was also significantly attenuated by PPEE treatment. The phosphorylated status of PI3K/Akt and MAPK were mitigated by PPEE treatment in UVB-exposed HaCaT cells. Moreover, PPEE treatment potently accelerated the expression of HO-1 and its transcription factor, nuclear factor-erythroid 2-related factor (Nrf)2, which is known for its anti-inflammatory activity. Conclusion : Consequently, PPEE treatment significantly regulated COX-2 and MMP-9 expressions in UVB-irradiated HaCaT cells. The inflammatory transcription factor AP-1, along with upstream signaling molecules PI3K/Akt and MAPKs, were also attenuated by PPEE treatment in UVB-exposed HaCaT cells. Additionally, PPEE treatment exaggerated HO-1 expression and Nrf2 activation, which might have contributed to the anti-inflammatory activity of PPEE. These results indicate that PPEE could be a candidate for attenuating UVB-induced photodamage in human skin.

Evaluation of Validity Thyroid Scintigraphy Using Parallel Hole Collimator (갑상샘 신티그래피 검사 시 평행다공형 조준기 적용의 유효성 평가)

  • Su-Young Park;Ji-Youn Kim;Sung-Min Ahn
    • Journal of the Korean Society of Radiology
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    • v.18 no.1
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    • pp.27-36
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    • 2024
  • In this study, When acquisition thyroid scintigraphy images, a parallel hole collimator was applied, and the difference from the pinhole collimator was quantitatively analyzed under each image acquisition condition. Visual size, resolution, sensitivity, signal to noise ratio (SNR), and contrast to noise ratio (CNR) were evaluated using thyroid phantom and point source. When comparing visual size, it was confirmed that an image similar to the size of the pinhole collimator could be obtained only when a magnification ratio of about 2.00 to 2.09 times when applying a parallel hole collimator. There was no tendency in FWHM(mm) measurement using a point source, and sensitivity was high in the parallel hole collimator. SNR and CNR were high when using a low magnification ratio, matrix size of 128×128, and a parallel hole collimator. In images of similar size to the naked eye, when the matrix size was the same, both SNR and CNR were high in the pinhole collimator. Therefore, when performing a thyroid scintigraphy test, if appropriate conditions are set according to the situation of each hospital and a parallel hole collimator is applied, it can be a good option in terms of equipment utilization and work efficiency.

Antioxidant and Anti-inflammatory Effects of Plantago asiatica L. Extract (질경이 추출물의 항산화 및 항염증 활성)

  • Choi, Yukyung;Choo, Byung-Kil
    • Korean Journal of Organic Agriculture
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    • v.32 no.1
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    • pp.91-105
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    • 2024
  • Plantago asiatica L. (P. asiatica) is a perennial plant belonging to the plantaginaceae and is useful in treating a various diseases such as wounds, bronchitis, and chronic constipation. The bioactive effects of P. asiatica extract was evaluated to determine its potential for use as a variety materials in the food, pharmaceutical, and agricultural industries. Polyphenol and flavonoid contents, free radical scavenging, reducing power activity, and reactive oxygen species (ROS) expression were measured to identify the antioxidative activity. Anti-inflammatory effects were evaluated via analysis of nitric oxide (NO) and pro-inflammatory protein expression in LPS-induced RAW 264.7 cell. As a result of measuring the antioxidant activities of the P. asiatica extract, the total polyphenol content was 50.91±0.78 mg gallic acid equivalents/g and the flavonoid content was 100.99±0.44 mg rutin equivalents/g, and both DPPH and ABTS radical scavenging activities and reducing power increased depending on the concentration. Also, intracellular ROS production was inhibited by the P. asiatica extract. No cytotoxicity was observed when P. asiatica extract was treated, and NO and inflammatory protein expression were inhibited, and nuclear factor kappa B (NF-κB) phosphorylation was also inhibited in a concentration-dependent manner. In conclusion, P. asiatica is a functional natural resources of antioxidant and anti-inflammatory agents that can be used in various industries, including food and agriculture.

Cellular Aging Inhibitory Effect of Perilla Leaf Extract on D-Galactose Induced C2C12 Myoblasts (D-갈락토스 유도 C2C12 근원세포에 대한 자소엽 추출물의 세포 노화 억제 효과)

  • Song-Mi Park;Sung-Woo Cho;Yung-Hyun Choi
    • Journal of Korean Medicine Rehabilitation
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    • v.34 no.2
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    • pp.15-28
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    • 2024
  • Objectives We used the D-galactose (D-gal) induced C2C12 myoblast senescence model to investigate whether ethanol extract of Perilla. fructescens leaves (EEPF) could delay cellular senescence and regulate related mechanisms. Methods C2C12 myogenic cells were cultured in an incubator under 37 ℃ and 5% CO2 conditions. EEPF, dried perilla leaves were pulverized and extracted at 1:10 (v/v) at 50 ℃ for 4 hours. Cell counting kit-8 and western blot analysis was performed. Annexin V-FITC apoptosis detection kit and DAPI staining was applied. Catalase (CAT), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and malondialdehyde analysis kits were used. To measure the level of reactive oxygen species generation, staining and flow cytometry was used. To analyze the mitochondrial activity, membrane potential changes were measured using JC-1. 𝛽-gal activity was analyzed using SA-𝛽-gal staining solution, and DNA damage was analyzed by using 𝛾-H2AX. Quantikine ELISA kit was used to analyze inflammatory cytokine production. Results According to the results of this study, EEPF significantly alleviated the decrease in cell viability in C2C12 cells treated with D-gal and suppressed the decrease in the expression of proliferating cell nuclear antigen. EEPF also markedly blocked D-gal-induced C2C12 cell apoptosis and restored reduced activity of CAT, GSH-Px, T-AOC, SOD. In addition, EEPF suppressed the decrease in 𝛽-galactosidase activity, the induction of DNA damage and the increase in expression of senescence-associated secretory phenotype proteins such as p16, p53 and p21 in D-gal-treated C2C12 cells. Furthermore, EEPF significantly attenuated D-gal-induced production and expression of inflammatory cytokines such as interleukin (IL)-6 and IL-18. Conclusions The results of this study indicate that EEPF can be used as a potential candidate for the prevention and treatment of muscle aging.

Bayesian Network-based Probabilistic Safety Assessment for Multi-Hazard of Earthquake-Induced Fire and Explosion (베이지안 네트워크를 이용한 지진 유발 화재・폭발 복합재해 확률론적 안전성 평가)

  • Se-Hyeok Lee;Uichan Seok;Junho Song
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.3
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    • pp.205-216
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    • 2024
  • Recently, seismic Probabilistic Safety Assessment (PSA) methods have been developed for process plants, such as gas plants, oil refineries, and chemical plants. The framework originated from the PSA of nuclear power plants, which aims to assess the risk of reactor core damage. The original PSA method was modified to adopt the characteristics of a process plant whose purpose is continuous operation without shutdown. Therefore, a fault tree, whose top event is shut down, was constructed and transformed into a Bayesian Network (BN), a probabilistic graph model, for efficient risk-informed decision-making. In this research, the fault tree-based BN from the previous research is further developed to consider the multi-hazard of earthquake-induced fire and explosion (EQ-induced F&E). For this purpose, an event tree describing the occurrence of fire and explosion from a release is first constructed and transformed into a BN. And then, this BN is connected to the previous BN model developed for seismic PSA. A virtual plot plan of a gas plant is introduced as a basis for the construction of the specific EQ-induced F&E BN to test the proposed BN framework. The paper demonstrates the method through two examples of risk-informed decision-making. In particular, the second example verifies how the proposed method can establish a repair and retrofit strategy when a shutdown occurs in a process plant.

Evaluation of the Effects of Interfering Factors on the Bacterial Endotoxin Testing of Radiopharmaceuticals (방사성의약품의 박테리아 엔도톡신 시험에서 반응간섭인자들의 영향에 대한 평가)

  • Jun Young PARK
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.2
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    • pp.171-180
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    • 2024
  • The endotoxin test is based on the reaction between Limulus Amebocyte Lysate (LAL) and the lipopolysaccharides of Gram-negative bacteria. In this study, we sought to identify factors that interfere with the LAL testing of radiopharmaceuticals and evaluated acceptable ranges. A gel-clot LAL test and a chromogenic LAL test were used as endotoxin tests. We compared the performances of the Endosafe LAL and recombinant Endosafe Recombinant Cascade Reagent (rCR) cartridges for the chromogenic test. The factors that interfered with 68Ga-DOTATOC injection were pH, 4-(2-hydroxyethyl) piperazine-1-ethanesulfonic acid (HEPES) buffer, and organic solvents, especially ethanol. However, interference by these factors was overcome by diluting the 68Ga-DOTATOC injection tenfold. In addition, no interference was observed at pH values between 4 and 8, at a HEPES concentration of 2,000 ㎍/mL, or an ethanol concentration of <1%. Furthermore, results showed that interfering factors had similar effects on the performances of the Endosafe LAL and Endosafe rCR cartridges. The results of this study are expected to be useful for evaluating factors that interfere with the endotoxin testing of new radiopharmaceuticals.