• Title/Summary/Keyword: complex resistance

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Problems and Solutions for Securing Fire Resistance Performance in Fire Protection doors (방화문 내화성능 확보에 대한 제도적 문제점 및 해결방안)

  • Kim, Juseong;Kim, Siwon;Cho, Youngduk;Kim, Jaejun
    • Korean Journal of Construction Engineering and Management
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    • v.21 no.2
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    • pp.22-29
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    • 2020
  • Among many fire-related laws and standards such as fire protection, fire doors are important facilities that play a role in preventing the spread of fire and smoke in the event of fire, thereby minimizing human casualties. Accordingly, the standards for performance required by applicable laws and regulations and related enforcement rules and notices have been continuously raised and the corresponding performance must be secured. However, due to the shortcomings of the relevant laws and systems, the test results of the fire doors confirmed that there was a risk of passing products. In this study, the criteria for fire-related performance were analyzed, and the performance required by other laws, in addition to simple fire protection, was identified, the criteria were organized, and the complex performance required was clearly.

Osteosarcopenic Obesity in Elderly: The Cascade of Bone, Muscle, and Fat in Inflammatory Process

  • Du, Yang;Oh, Chorong;No, Jae-kyung
    • Culinary science and hospitality research
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    • v.23 no.6
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    • pp.173-183
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    • 2017
  • Conditions related to body composition and aging, such as osteopenic obesity, sarcopenia/ sarcopenic obesity, and the newly termed osteosarcopenic obesity(triad of bone, muscle and adipose tissue impairment), are beginning to gain recognition. Currently, it has begun to attract the attention of scholars from all over the world, however, for this disease, it still needs a more clear understanding and perception. Therefore, this article considered the osteoporosis, muscle depression, and obesity, these diseases as a gate to study the relationship among muscle, bone, and fat. In addition, in the aging process, the formation of IGF-cortisol, testosterone, and estrogen is sensitive. These hormones can not only absorb muscle protein metabolism, but also affect alienation. The decrease in IGF-cortisol in the elderly resulted in increased visceral fat, decreased muscle mass and bone mineral density, and then affected decreased skeletal muscle atrophy and decreased quality. The reduction of skeletal muscle quality and strength and increase body fat affected the adipose tissue to produce inflammatory cytokines, thereby reduced skeletal muscle, promoted cardiovascular disease, metabolic syndrome and insulin resistance in chronic diseases. Almost all chronic inflammatory diseases were associated with bone, muscle and fat. These mechanisms were complex and interrelated. Inflammation reduces bone formation, increases fat and reduces muscle mass. And thus not only had a significant impact on the motor system, but also made the incidence increase of fracture, osteoporosis, fragile syndrome, fall, osteomalacia and other bone disease. This article aimed to start from the interaction between the muscles and bones of the elderly, extended to obesity, muscle deficiency, osteoporosis and other diseases, finally, from a nutritional point of view, to discuss how to treat osteoporosis obesity.

Autotransplantation of Premolars and Esthetic Rehabilitation in a Traumatized Teenage Patient with Challenging Oral Problems: A Case Report (어려운 구강 문제를 가진 외상당한 청소년 환자의 소구치 자가이식 및 심미적 회복: 증례 보고)

  • Kho, Junhee;Park, Howon;Lee, Juhyun;Seo, Hyunwoo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.47 no.2
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    • pp.213-218
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    • 2020
  • The loosely structured periodontal ligament and low mineralized bone surrounding erupting teeth provide minimal resistance to an extrusive force. The maxillary central incisors are the most frequently avulsed due to trauma. The prognosis of replanted teeth is affected by extra-alveolar period and conditions. Implant-supported restorations are contraindicated in adolescent patients with poor prognosis traumatized teeth. Autotransplantation of premolar to the anterior region provides a viable treatment alternative. This case report describes the autotransplantation of premolars and esthetic rehabilitation in a teenage patient with traumatized incisors, poor oral hygiene, and severe crowding. Comprehensive and long-term treatments were performed to improve complex and challenging oral problems.

Evaluation of Material Properties in Austenite Stainless Steel Sheet with Scanning Acoustic Microscopy (초음파현미경을 이용한 오스테나이트 스테인레스강의 재료특성 평가)

  • Park, Tae-Sung;Kasuga, Yukio;Park, Ik-Keun;Kim, Kyoung-Suk;Miyasaka, Chiaki
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.2
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    • pp.267-275
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    • 2012
  • Austenite stainless steel 304 has properties of high resistance to corrosion and temperature changes. Therefore, this material is widely used in various of industries. However, when the material is subjected to heating and cooling cycles the forming accuracy, for example, the right angle associated with a sharp bend such as corner is lost. This phenomenon is caused by the reversion of the deformation-induced martensite into austenite when the temperature in increased. This result in misfit of a structure or an assembly, and an increase in residual stress. Hence, it is important to understand this process. In this study, to evaluate the mechanical behavior of the deformation-induced martensite and reversed austenite, a scanning acoustic spectroscope including the capability of obtaining both phase and amplitude of the ultrasonic wave (i.e., the complex V(z) curve method) was used. Then, the velocities of the SAW propagating within the specimens made in different conditions were measured. The experimental differences of the SAW velocities obtained in this experiment were ranging from 2,750 m/s to 2,850 m/s, and the theoretical difference was 3.6% under the assumption that the SAW velocity was 2,800 m/s. The error became smaller as the martensite content was increased. Therefore, the SAW velocity may be a probe to estimate the marternsite content.

Creep Damage Evaluation of High-Temperature Pipeline Material for Fossil Power Plant by Frequency Spectrum Analysis Method (주파수분석법에 의한 발전소 고온배관재료의 크리프손상 평가)

  • Lee, Sang-Guk;Lee, In-Cheol;Chang, Hong-Keun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.1
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    • pp.10-17
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    • 2000
  • In boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants, conventional measurement techniques(replica method, electric resistance method, and hardness test method) for measuring creep damage have such disadvantages as complex preparation and measurement procedures, too many control parameters. And also, these techniques have low practicality and applied only to component surfaces with good accessibility. It needs to apply a reliable and quantitative ultrasonic nondestructive evaluation method that can be replaced for these equipment. In this study, both artificial creep degradation test using life prediction formula and frequency analysis by ultrasonic tests for crept specimens were carried out for the purpose of nondestructive evaluation for creep damage. As a result of ultrasonic tests for crept specimens, we conformed that the high frequency side spectra decrease and central frequency components shift to low frequency band, and also their bandwidth decreases as increasing creep damage in backwall echos.

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Creep Damage Evaluation of Cr-Mo Steel High-Temperature Pipeline Material for Fossil Power Plant Using Ultrasonic Test Method (초음파법을 이용한 Cr-Mo강 고온배관재료의 크리프손상 평가)

  • Lee, Sang-Guk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.1
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    • pp.18-26
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    • 2000
  • Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operating conditions such as high temperature and high pressure for an extended period time. Conventional measurement techniques(replica method, electric resistance method, and hardness test method) for measuring creep damage have such disadvantages as complex preparation and measurement procedures, too many control parameters. And also these techniques have low practicality and applied only to component surfaces with good accessibility. In this paper, artificial creep degradation test and ultrasonic measurement for their creep degraded specimens(Cr-Mo alloy steels) were carried out for the purpose of evaluation for creep damage. Absolute measuring method of quantitative ultrasonic measurement for material degradation was established, and long term creep degradation tests using life prediction formula were carried out. As a result of ultrasonic tests for crept specimens. we conformed that both the sound velocity decreased and attenuation coefficient linearly increased in proportion to the Increase of creep life fraction($\Phi$c).

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Co-expression of MDRI and HLA-B7 Genes in a Mammalian Cell Using a Retrovirus

  • Lee, Seong-Min;Lee, Kyoo-Hyung;Kim, Hag-Dong;Lee, Je-Hwan;Lee, Jung-Shin;Kim, Joon
    • BMB Reports
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    • v.34 no.2
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    • pp.176-181
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    • 2001
  • Using a retrovirus, foreign genes can be introduced into mammalian cells. The purpose of this study is to produce a retrovirus that can make the infected cells express two genes; the human multidrug resistance gene (MDR1) and the HLA-B7 gene, which is one of the major human histocompatibility complex (MHC) class I genes. For the expression of these genes, the internal ribosome entry site (IRES) was used, which was derived from the encephalomyocarditis (EMC) virus. In order to produce retroviruses, a retroviral vector was transfected into a packaging cell line and the transfected cells were treated with vincristine, which is an anti-cancer drug and a substrate for the MDRI gene product. This study revealed that two genes were incorporated into chromosomes of selected cells and expressed in the same cells. The production of the retrovirus was confirmed by the reverse transcription (RT)-PCR of the viral RNA. The retrovirus that was produced infected mouse fibroblast cells as well as the human U937. This study showed that packaging cells produced the retroviruses, which can infect the target cells. Once the conditions for the high infectivity of retrovirus into human cells are optimized, thus virus will be used to infect hematopoietic stem cells to co-express MDRl and HLA-B7 genes, and develop the lymphocytes that can be used for the immnogene therapy.

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Antioxidant mechanism of black garlic extract involving nuclear factor erythroid 2-like factor 2 pathway

  • Ha, Ae Wha;Kim, Woo Kyoung
    • Nutrition Research and Practice
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    • v.11 no.3
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    • pp.206-213
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    • 2017
  • BACKGROUN/OBJECTIVES: Although studies have revealed that black garlic is a potent antioxidant, its antioxidant mechanism remains unclear. The objective of this study was to determine black garlic's antioxidant activities and possible antioxidant mechanisms related to nuclear factor erythroid 2-like factor 2 (Nrf2)-Keap1 complex. METHODS/MATERIALS: After four weeks of feeding rats with a normal fat diet (NF), a high-fat diet (HF), a high-fat diet with 0.5% black garlic extract (HF+BGE 0.5), a high-fat diet with 1.0% black garlic extract (HF+BGE 1.0), or a high-fat diet with 1.5% black garlic extract (HF+BGE 1.5), plasma concentrations of glucose, insulin,homeostatic model assessment of insulin resistance (HOMA-IR) were determined. As oxidative stress indices, plasma concentrations of thiobarbituric acid reactive substances (TBARS) and 8-isoprostaglandin $F2{\alpha}$ (8-iso-PGF) were determined. To measure antioxidant capacities, plasma total antioxidant capacity (TAC) and activities of antioxidant enzymes in plasma and liver were determined. The mRNA expression levels of antioxidant related proteins such as Nrf2, NAD(P)H: quinone-oxidoreductase-1 (NQO1), heme oxygenase-1 (HO-1), glutathione reductase (GR), and glutathione S-transferase alpha 2 (GSTA2) were examined. RESULTS: Plasma glucose level, plasma insulin level, and HOMA-IR in black garlic supplemented groups were significantly (P < 0.05) lower than those in the HF group without dose-dependent effect. Plasma TBARS concentration and TAC in the HF+BGE 1.5 group were significantly decreased compared to those of the HF group. The activities of catalase and glutathione peroxidase were significantly (P < 0.05) increased in the HF+BGE 1.0 and HF+BGE 1.5 groups compared to those of the HF group. The mRNA expression levels of hepatic Nrf2, NQO1, HO-1, and GSTA2 were significantly (P < 0.05) increased in the HF with BGE groups compared to those in the HF group. CONCLUSIONS: The improvements of blood glucose homeostasis and antioxidant systems in rats fed with black garlic extract were related to mRNA expression levels of Nrf2 related genes.

Physical Property and Morphology Observation of HepG2 Cells by Various Concentration of Paraquat (파라쿼트 농도에 따른 HepG2 세포의 물리적 특성 변화와 실시간 모폴로지 관찰)

  • Lee, Dong-Yun;Kang, Hyen-Wook;Muramatsu, Hiroshi;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1232_1233
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    • 2009
  • Paraquat is well-known to cause hepatotoxic responses in human and other mammal species. In solution, it forms free radicals and charge-transfer complex of which formation plays an important role in determination of its biological activity in the presence of various anions. The HepG2 cells were cultured onto a quartz crystal sensor which is possible to detect the density and a viscosity changes using the resonance frequency (F) and the resonance resistance (R). The plot of F-R diagram is able to explain the rheological change of cells onto the surface of the quartz crystal sensor. In this paper, we investigated the physical properties of the HepG2 cells cultured onto a ITO electrode of the quartz crystal sensor according to the paraquat injection at various concentrations (100 mM, 10 mM, 1 mM). We also observed the morphological changes with a micro CCD camera, simultaneously. The HepG2 cells were cultured onto the ITO electrode surface of the quartz crystal modified a collagen film in $CO_2$ incubator. After the paraquat injection, we observed the changes of the morphologies by the micro CCD camera depending on time and analyzed the physical changes of cells on the electrode surface of quartz crystal using F-R diagram. From all results, we proved the effect of paraquat at various concentrations which is led to an apoptosis such as weakening and death of the cells by oxidation and reduction reaction that were produced the superoxide anions and other free radicals.

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Enhancement of antimicrobial peptide genes expression in Cactus mutated Bombyx mori cells by CRISPR/Cas9

  • Park, Jong Woo;Yu, Jeong Hee;Kim, Seong-Wan;Kweon, Hae Yong;Choi, Kwang-Ho;Kim, Seong-Ryul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.37 no.1
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    • pp.21-28
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    • 2018
  • CRISPR/Cas9 gene editing system is an efficient method to mutation in a sequence specific manner. Here we report the direct transfection of the Cas9 nuclease and gene specific guide RNA can be used in BM-N cell line derived from Bombyx mori ovarian tissue to enfeeble function of endogenous gene in vitro. We have used gene editing system to negative regulation components of major signaling cascade, the Toll pathway, which controls B. mori resistance to microbe infections, such as fungi and gram positive bacteria. We demonstrate that the $I{\kappa}B-like$ protein Cactus may controls the activation of transcription factors such as Rel A and Rel B. The direct transfection of Cas9 nuclease and Cactus-specific guide-RNA complex may be used in BM-N cells to disrupt the function of endogenous genes in vitro. A mutation frequency of 30-40% was observed in the transfected cells, and various mutations caused the target region. Moreover, RT-PCR analysis revealed that Cactus gene was down regulated after these mutations. More importantly, mutation of BmCactus stimulated expression of lysozyme, moricin, and lebocin genes. These results suggest that the CRISPR/Cas9 systems are expected to efficiently induce site-specific mutations and it was possible to produce antimicrobial peptide through the gene editing.