• Title/Summary/Keyword: adhesion

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A Study on the Joint Tensile Strength of EVA Waterproofing Sheet According to Hot Air Welding Speed and Chemical Attack in Low Temperature (저온 환경에서의 열풍융착 속도별 화학적 침식이 EVA 방수시트의 접합부 인장강도에 미치는 영향에 대한 연구)

  • Park, Jin-Sang;Choi, Su-Young;Park, Wan-Goo;Jung, Hae-Choon;Kim, Byoung-Il;Oh, Sang-Keun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.3
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    • pp.320-326
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    • 2017
  • This study is based on the hot air welding application method of EVA sheet to test the tensile strength performance changes due to the hot air welding speed, temperature and chemical attack. For the parameters of the study, the hot air welding method that directly heats the overlap between the sheets and the adhesion surface was controlled, and the maximum temperature for application was set to $20^{\circ}C$, $0^{\circ}C$, $-5^{\circ}C$, $-10^{\circ}C$. According to the results of the testing, the tensile strength of the overlap area was the highest between the temperatures of 20 at 5~6m/min and between the low temperatures at 3~4m/min of hot air welding speed.

Evaluation of Crack Resistance of Cold Joint as Usage of Sealing Tape (실링 테이프 적용에 따른 시공조인트 균열 저항성 평가)

  • Lee, JaeJun;Lee, Seonhaeng;Kim, Du-Byung;Lee, Jinwook
    • International Journal of Highway Engineering
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    • v.20 no.3
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    • pp.1-9
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    • 2018
  • PURPOSES : In order to evaluate a crack resistance at cold joint, sealing tape was adopted to apply at cold joint instead of typical tack coat material(RSC-4). The sealing tape was made by hot sealing material. The crack resistance as function of environmental and traffic loading was measured with visual observation. METHODS : In this study, the crack resistance was evaluated as function of environmental and traffic loading. The freeze-thaw method was adopted for environmental loading of asphalt pavement. condition. The damage of cold joint under freeze-thaw action is initiated by ice expansion load and accelerated by the interfacial damage between new and old asphalt pavement. The traffic loading was applied with wheel tracking machine on the cold joint area of the asphalt pavement for 3 hours at $25^{\circ}C$. The evaluation of crack resistance was measured with visual observation. The freeze-thaw results shows that the sealing tape was significantly increased the crack resistance based on. RESULTS : To estimate the crack resistance at cold joint area due to the environmental loading, the Freeze-thaw test was conducted by exposing the product to freezing temperature(approximately $-18^{\circ}C$) for 24 hours, and then allowing it to thaw at $60^{\circ}C$ for 24 hours. The tack coat material(RSC-4) was debonded after 21 cycles of the Freeze-thaw test. The first crack was observed after 14 freeze-thaw cycle with RSC-4 material. But, the sealing tape was not debonded after 24 cycle test. Also, the sealing tape shows the better performance of the crack resistance under the traffic loading with wheel track test. The crack was generated the under traffic loading with RSC-4(tack coating), however, the crack was not shown with sealing tape. It indicates that the sealing tape has a strong resistance of tensile stress due to traffic loading. CONCLUSIONS :Based on limited laboratory test result, a performance of crack resistance using the sealing tape is better than that of general tack coat material(RSC-4). It means that the sealing tape is possible to extend a pavement service life because the crack, one of the main pavement distresses, will be delayed.

Serological Studies on the Specific Antibodies Against P-pili of Uropathogenic Escherichia coli (요로 감염환자에서 혈청학적 방법을 이용한 P-pili특이혈중 항체의 조사)

  • 이원용;김종배
    • Biomedical Science Letters
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    • v.2 no.1
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    • pp.31-40
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    • 1996
  • Escherichia coli is one of the most common etiological agents in urinary tract infection. An important virulence factor is the adhesive capacity of E. coli to uroepithelial cell, mediated by bacterial fimbriae. The Adhesion property has been regarded as an important virulence determinant in urinary tract infections. A total of 60 patients, who were diagnosed microbiologically as urinary tract infections, were examined by immunoblotting and enzyme-linked immunosorbent assay(ELISA). Uropathogenic E. coli with recombinant plasmid were positive for mannose resistant hemagglutination (MRHA). For identification of p-fimbriae subtype in uropathogenic E. coli, In the immunoblot analysis, specific bands in the range of p-fimbriae molecular weight of 17KD-22KD were identified. For the distribution of p-fimbriae subtype in the patient sera, 34/60(56.7%) were positive for $F7_1$, 28/60(46.7%) were positive for $F7_2$, and 30/60(50%) were positive for F13 with immunoblotting method. similar trends were observed in the enzyme-linked immunosorbent assay. Relatively good specificity(92.6%) and sensitivity(90%) were found in the ELISA test system using mixed antigens of purified $F7_1$, $F7_2$, and F13 p-fimbriae, and 60 sera from patients with urinary tract infections. In conclusion The serological tests were convenient method in diagnosis of urinary tract infections. among those ELISA could be recommended in diagnosis of urinary tract infections.

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G protein-coupled receptors in stem cell maintenance and somatic reprogramming to pluripotent or cancer stem cells

  • Choi, Hye Yeon;Saha, Subbroto Kumar;Kim, Kyeongseok;Kim, Sangsu;Yang, Gwang-Mo;Kim, BongWoo;Kim, Jin-Hoi;Cho, Ssang-Goo
    • BMB Reports
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    • v.48 no.2
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    • pp.68-80
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    • 2015
  • G protein-coupled receptors (GPCRs) are a large class of transmembrane receptors categorized into five distinct families: rhodopsin, secretin, adhesion, glutamate, and frizzled. They bind and regulate 80% of all hormones and account for 20-50% of the pharmaceuticals currently on the market. Hundreds of GPCRs integrate and coordinate the functions of individual cells, mediating signaling between various organs. GPCRs are crucial players in tumor progression, adipogenesis, and inflammation. Several studies have also confirmed their central roles in embryonic development and stem cell maintenance. Recently, GPCRs have emerged as key players in the regulation of cell survival, proliferation, migration, and self-renewal in pluripotent (PSCs) and cancer stem cells (CSCs). Our study and other reports have revealed that the expression of many GPCRs is modulated during the generation of induced PSCs (iPSCs) or CSCs as well as during CSC sphere formation. These GPCRs may have crucial roles in the regulation of self-renewal and other biological properties of iPSCs and CSCs. This review addresses the current understanding of the role of GPCRs in stem cell maintenance and somatic reprogramming to PSCs or CSCs.

Immune-triggering effect of the foodborne parasite Kudoa septempunctata through the C-type lectin Mincle in HT29 cells

  • Shin, Ji-Hun;Yang, Jung-Pyo;Seo, Seung-Hwan;Kim, Sang-Gyun;Kim, Eun-Min;Ham, Do-Won;Shin, Eun-Hee
    • BMB Reports
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    • v.53 no.9
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    • pp.478-483
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    • 2020
  • Kudoa septempunctata is a myxozoan parasite that causes food poisoning in individuals consuming olive flounder. The present study aimed to investigate the currently insufficiently elucidated early molecular mechanisms of inflammatory responses in the intestine owing to parasite ingestion. After Kudoa spores were isolated from olive flounder, HT29 cells were exposed to spores identified to be alive using SYTO-9 and propidium iodide staining or to antigens of Kudoa spores (KsAg). IL-1β, IL-8, TNF-α and NFKB1 expression and NF-κB activation were assessed using real-time PCR, cytokine array and western blotting. The immunofluorescence of FITC-conjugated lectins, results of ligand binding assays using Mincle-Fc and IgG-Fc, CLEC4E expressions in response to KsAg stimulation, and Mincle-dependent NF-κB activation were assessed to clarify the early immune-triggering mechanism. Inflammatory cytokines (IL-1β, GM-CSF and TNF-α), chemokines (IL-8, CCL2, CCL5 and CXCL1) and NF-κB activation (pNF-κB/NF-κB) in HT29 cells increased following stimulation by KsAg. The immunofluorescence results of spores and lectins (concanavalin A and wheat germ agglutinin) suggested the importance of Mincle in molecular recognition between Kudoa spores and intestinal cells. Practically, data for Mincle-Fc and KsAg binding affinity, CLEC4E mRNA expression, Mincle immunofluorescence staining and hMincle-dependent NF-κB activation demonstrated the involvement of Mincle in the early immune-triggering mechanism. The present study newly elucidated that the molecular recognition and immune-triggering mechanism of K. septempunctata are associated with Mincle on human intestinal epithelial cells.

Estimation of Bond Performance Improvement by Surface Treatment Equipments and Polymer Content by Boned Concrete Overlays (접착식 콘크리트 덧씌우기 경계면 처리 방식 및 폴리머 혼입률에 따른 부착성능 평가)

  • Jung, Won Kyong;Kim, Hyun Seok;Kwon, Oh Seon;Kim, Hyung Bae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.1
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    • pp.39-47
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    • 2016
  • Repair methods of aging concrete pavement are generally used composite structure pavements, such a composite structure is subjected to a large impact on the mechanical behavior and ensure long-term commonality integrated under vehicle loads, environmental loads of the public in accordance with the bond strength between old and new concrete. A common of bonded concrete overlays that are currently available is Interface arrangements using a variety of equipment to ensure the excellent bond strength between old and new concrete than standard concrete, mixed with a material such as a polymer in order to improve the adhesion with the material itself. However, these method of constructions are being applied, depending on the developer site presents no special specifications apply when a specific application criteria objectively, this is due to the situation of each individual method, which is based on the difficulty in quality control of the site manager. In this study by performing a field test for polymer content via the variables that contribute most significantly to ensure bond strength and the field element core of the interface processing method and materials to ensure bond strength between the old and the new concrete, it was to derive the construction site construction method that can improve the performance of the bond strength through a review of the construction around the correlations and the bond strength according to the effective performance analysis of the conventional surface treatment process and variation of polymer volume fraction.

A Study on Improvement of Durability for Run-out Table Roller with Hot Rolling by Porous Self-fluxing Alloy Coating (다공질 자용성 합금 피복에 의한 열간 압연용 런-아웃 테이블 롤러의 내구성 향상에 관한 연구)

  • Bae, Myung-Whan;Park, Byoung-Ho;Jung, Hwa
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.2
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    • pp.276-285
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    • 2012
  • The objective of this research is to develop the coating technique by a porous self-fluxing alloy for improving the mechanical properties of run-out table roller surface with the hot rolling. To enhance the durability of run-out table roller with the hot rolling, the high hardness of roller surface should be maintained at high temperatures, and the improvement of wear resistance, corrosion resistance, heat resistance, burn resistance and adhesion resistance should be maintained. In order to be able to transport reliably a hot rolled steel sheet, also, the appropriate friction coefficient on the roller surface should be maintained and the slip between roller and steel should not occur. In this study, the wear resistance of roller increases after the self-fluxing alloy is changed to a cermet by adding the tungsten carbide(WC), and the coefficient of friction increases and the ability of grip is improved because the porosities are made by coating with fine iron powder on the roller surface. As a result, it is found that the ability of grip between the steel and the roller coated by a porous self-fluxing alloy contained to 5 ~ 10 wt% of Fe in the coating layer is improved compared to the roller coated by Ni-Cr. This is because the porosities are made after Fe contained in the roller is partially alloyed by heating with a furnace in the fusing process and the rest is eliminated by oxidation and dissolution.

Action and Signaling of Lysophosphatidylethanolamine in MDA-MB-231 Breast Cancer Cells

  • Park, Soo-Jin;Lee, Kyoung-Pil;Im, Dong-Soon
    • Biomolecules & Therapeutics
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    • v.22 no.2
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    • pp.129-135
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    • 2014
  • Previously, we reported that lysophosphatidylethanolamine (LPE), a lyso-type metabolite of phosphatidylethanolamine, can increase intracellular $Ca^{2+}$ ($[Ca^{2+}]_i$) via type 1 lysophosphatidic acid (LPA) receptor ($LPA_1$) and CD97, an adhesion G-protein-coupled receptor (GPCR), in MDA-MB-231 breast cancer cells. Furthermore, LPE signaling was suggested as like $LPA_1/CD97-G_{i/o}$ proteins-phospholipase $C-IP_3-Ca^{2+}$ increase in these cells. In the present study, we further investigated actions of LPE not only in the $[Ca^{2+}]_i$ increasing effect but also in cell proliferation and migration in MDA-MB-231 breast cancer cells. We utilized chemically different LPEs and a specific inhibitor of $LPA_1$, AM-095 in comparison with responses in SK-OV3 ovarian cancer cells. It was found that LPE-induced $Ca^{2+}$ response in MDA-MB-231 cells was evoked in a different manner to that in SK-OV3 cells in terms of structural requirements. AM-095 inhibited LPE-induced $Ca^{2+}$ response and cell proliferation in MDA-MB-231 cells, but not in SK-OV3 cells, supporting $LPA_1$ involvement only in MDA-MB-231 cells. LPA had significant effects on cell proliferation and migration in MDA-MB-231 cells, whereas LPE had less or no significant effect. However, LPE modulations of MAPKs (ERK1/2, JNK and p38 MAPK) was not different to those by LPA in the cells. These data support the involvement of LPA1 in LPE-induced $Ca^{2+}$ response and cell proliferation in breast MDA-MB-231 cells but unknown GPCRs (not $LPA_1$) in LPE-induced responses in SK-OV3 cells. Furthermore, although LPE and LPA utilized $LPA_1$, LPA utilized more signaling cascades than LPE, resulting in stronger responses by LPA in proliferation and migration than LPE in MDA-MB-231 cells.

Recent Studies on the Edible Plant Vaccine for Prophylactic Medicine against Microorganism-Mediated Diseases (세균성 질병 예방을 위한 식물 경구 백신 연구 동향)

  • Hahn Bum-Soo;Jeong Young-Jae;Roh Kyung-Hee;Park Jong-Sug;Cho Kang-Jin;Kim Yong-Hwan;Kim Jong-Bum
    • Journal of Plant Biotechnology
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    • v.32 no.4
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    • pp.233-241
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    • 2005
  • Plants have considerable advantages for the production of antigenic proteins because they provide an inexpensive source of protein and an easy administration of vaccine. Since a publication describing edible plant vaccine of HBsAg in 1992, a number of laboratories around the world have studied the use of plants as the bioreactor to produce antigenic proteins of human or animal pathogens. Over the last ten years, these works have been mainly focused on three major strategies for the production of antigenic proteins in plants: stable genetic transformation of either the nuclear or plastid genome, or transient expression in plants using viral vectors. As many antigenic proteins have been expressed in tobacco, also several laboratories have succeeded to express genes encoding antigenic proteins in other crop plants: potato, tomato, maize, carrot, soybean and spinach. At present many works for the production of edible plant vaccine against bacteria-mediated diseases have mostly performed the studies of enterotoxins and adhesion proteins. Also the development of new-type antigens (pili, flagella, surface protein, other enterotoxin and exotoxin etc.) is required for various targets and more efficacy to immunize against microorganism pathogens. Many works mostly studied in experimental animals had good results, and phase I clinical trial of LTB clearly indicated its immunogenic ability. On the other hand, edible plant vaccines have still problems remained to be solved. In addition to the accumulation of sufficient antigen in plants, human health, environment and agriculture regulation should be proven. Also oral tolerance, the physiological response to food antigens and commensal flora is the induction of a state of specific immunological unresponsiveness, needs to be addressed before plant-derived vaccine becomes a therapeutic option.

Inhibition Effect of Taxilli Ramulus Extract on Osteoclast Differentiation and Bone Resorption (상기생 추출물이 파골세포 분화와 골흡수 억제에 미치는 효과)

  • Baek, Jong Min;Kim, Ju Young;Lee, Myeung Su;Jeung, Woo Jin;Moon, Seo Young;Jeon, Byung Hoon;Oh, Jae Min;Choi, Min Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.4
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    • pp.431-436
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    • 2013
  • Bone homeostasis is maintained by co-ordination of bone-resorbing osteoclasts and bone-forming osteoblasts. Imbalance between osteoclasts and osteoblasts leads to many bone diseases such as osteoporosis, rheumatoid arthritis. Taxillus chinensis is a herb that has been widely used to improve bone health. However, the effect and mechanism of Taxillus chinensis extract on osteoclast differentiation and bone resportion has been unknown. Thus, We investigated the effect of Taxillus chinensis on expression of receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation and bone resorption. Also, the action of Taxillus chinensis on mechanisms relating to osteoclast differentiation was studied. In this results, we identified that Taxillus chinensis significantly inhibited RANKL-induced osteoclast differentiation and bone resportion. Moreover, Taxillus chinensis was suppressed the activation of NF-${\kappa}B$ in bone marrow macrophage treated RANKL and M-CSF. Taxillus chinensis was down-regulated the mRNA expression of c-Fos, nuclear factor of activated T-cells (NFAT)c1, osteoclast-associated receptor (OSCAR), tartrate-resistant acid phosphatase (TRAP). The cell adhesion-related molecules such as integrin ${\alpha}v$ and integrin ${\beta}3$, and the filamentous actin (F-actin) rings of mature osteoclasts-related molecules such as dendritic cell-specific transmembrane preotein (DC-STAMP) and cathepsin K are also suppressed. Taken together, these results indicated that Taxillus chinensis will be a good candidate to treat osteoclast-mediated bone diseases.