• Title/Summary/Keyword: Internal degradation

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Increased Mucin Release from Chronic Bronchial Asthma Patients

  • Shin, Chan-Yound;Park, Kyu-Hwan;Lee, Woo-Jong;Kim, Do-Jin;Park, Chun-Sik;Park, Sung-Hak;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
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    • v.8 no.2
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    • pp.107-112
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    • 2000
  • To investigate the alteration of airway mucin in airway disease patients, immunoassay procedures were employed using monoclonal antibodies HM02 and HM03 (Hybridoma, 18,457-463, 1999). Alteration of mucin release was determined by ELISA and the integrity of mucin was determined by Western blot. In ELISA, it was found that mucin release increased from pneumonia, chronic cough, bronchiectasis, eosinophilic pneumonia, lung cancer and bronchial asthma patients. In Western blot, the increase in immunoreactivity was observed in case of pneumonia, chronic cough, bronchiectasis and bronchial asthma. In bronchial asthma, there was no obvious degradation of mucin while in other diseases, varying degree of mucin degradation was observed. The data from the present study implicate that HMO2 and HM03 are suitable for the immunological analysis of mucin in airway disease patients. The role of increased mucin release and varying degree of mucin degradation on airway diseases should be further investigated in the future.

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Degradation Diagnosis of Overhead Power Lines Using Eddy Current Technology (와전류 기법을 이용한 가공전력선 열화 진단)

  • Kim, Chng-Hyeok;Kim, Tag-Yong;Oh, Yong-Cheul;Choi, Woon-Sik;Jo, Choon-Nam
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.5
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    • pp.322-327
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    • 2014
  • Internal corrosion of the distribution line can be detected in order to develop techniques of non-destructive inspection methods that operate only on the metal track eddy current diagnosis is possible by applying the technique investigated. Sensor for the production of a finite element method modeled by using an eddy current sensor, a distribution line by using an accelerated aging samples of sodium hydroxide was prepared. Sheathed cables for internal corrosion studies detected using an eddy current sensor is considered to be possible.

Development of Diagnostic Device for Internal Degradation in Distribution Line Using NDT Mathod (NDT 기법을 이용한 가공배전선로 내부 열화 진단장치 개발)

  • Hyun, Deuk-Chang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.8
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    • pp.539-543
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    • 2015
  • At present, the development of a detection device in order to prevent accidents due to wire deterioration in the distribution lines is required. Distribution line is not possible to check the internal state in a normal way because it is covered with the coating. Accordingly, various eddy current techniques that is the non-destructive test (NDT) techniques have been applied to solve this problem. In this paper, we have seen examining the characteristic change of the eddy current sensor according to the simplified shape of the sensor in order to solve the problems for the simplified shape that is generated when the simulation for the shape of the eddy current sensor.

Globular Adiponectin Exerts a Pro-Inflammatory Effect via IκB/NF-κB Pathway Activation and Anti-Inflammatory Effect by IRAK-1 Downregulation

  • Lee, Kyoung-Hee;Jeong, Jiyeong;Woo, Jisu;Lee, Chang-Hoon;Yoo, Chul-Gyu
    • Molecules and Cells
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    • v.41 no.8
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    • pp.762-770
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    • 2018
  • Adiponectin, a hormone produced by adipose tissue, is very abundant in plasma, and its anti- and pro-inflammatory effects are reported. However, the mechanisms of these pro- and anti-inflammatory effects are not fully defined. Herein, we evaluated the dual inflammatory response mechanism of adiponectin in macrophages. Short-term globular adiponectin (gAd) treatment induced $I{\kappa}B{\alpha}$ degradation, $NF-{\kappa}B$ nuclear translocation, and $TNF-{\alpha}$ production in RAW 264.7 cells. Polymyxin B pretreatment did not block gAd-induced $I{\kappa}B{\alpha}$ degradation, and heated gAd was unable to degrade $I{\kappa}B{\alpha}$, suggesting that the effects of gAd were not due to endotoxin contamination. gAd activated IKK and Akt, and inhibition of either IKK or Akt by dominant-negative $IKK{\beta}$ ($DN-IKK{\beta}$) or DN-Akt overexpression blocked gAd-induced $I{\kappa}B{\alpha}$ degradation, suggesting that short-term incubation with gAd mediates inflammatory responses by activating the $I{\kappa}B/NF-{\kappa}B$ and PI3K/Akt pathways. Contrastingly, long-term stimulation with gAd induced, upon subsequent stimulation, tolerance to gAd, lipopolysaccharide, and CpG-oligodeoxynucleotide, which is associated with gAd-induced downregulation of IL-receptor-associated kinase-1 (IRAK-1) due to IRAK-1 transcriptional repression. Conclusively, our findings demonstrate that the pro- and anti-inflammatory responses to gAd in innate immune cells are time-dependent, and mediated by the activation of the $I{\kappa}B/NF-{\kappa}B$ pathway, and IRAK-1 downregulation, respectively.

Glyoxalase 1 as a Therapeutic Target in Cancer and Cancer Stem Cells

  • Ji-Young, Kim;Ji-Hye, Jung;Seung-Joon, Lee;Seon-Sook, Han;Seok-Ho, Hong
    • Molecules and Cells
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    • v.45 no.12
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    • pp.869-876
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    • 2022
  • Methylglyoxal (MG) is a dicarbonyl compound formed in cells mainly by the spontaneous degradation of the triose phosphate intermediates of glycolysis. MG is a powerful precursor of advanced glycation end products, which lead to strong dicarbonyl and oxidative stress. Although divergent functions of MG have been observed depending on its concentration, MG is considered to be a potential antitumor factor due to its cytotoxic effects within the oncologic domain. MG detoxification is carried out by the glyoxalase system. Glyoxalase 1 (Glo1), the ubiquitous glutathionedependent enzyme responsible for MG degradation, is considered to be a tumor promoting factor due to it catalyzing the removal of cytotoxic MG. Indeed, various cancer types exhibit increased expression and activity of Glo1 that closely correlate with tumor cell growth and metastasis. Furthermore, mounting evidence suggests that Glo1 contributes to cancer stem cell survival. In this review, we discuss the role of Glo1 in the malignant progression of cancer and its possible use as a promising therapeutic target for tumor therapy. We also summarize therapeutic outcomes of Glo1 inhibitors as prospective treatments for the prevention of cancer.

Thermal Distribution Analysis in Nano Cell OLED (나노 셀 OLED의 열 분포 해석)

  • Kyung-Uk Jang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.3
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    • pp.309-313
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    • 2024
  • The key to determining the lifetime of OLED device is how much brightness can be maintained. It can be said that there are internal and external causes for the degradation of OLED devices. The most important cause of internal degradation is bonding and degradation in the excited state due to the electrochemical instability of organic materials. The structure of OLED modeled in this paper consists of a cathode layer, electron injection layer (EIL), electron transport layer (ETL), light emission layer, hole transport layer (HTL), hole injection layer (HIL), and anode layer on a glass substrate from top to bottom. It was confirmed that the temperature generated in OLED was distributed around the maximum of 343.15 K centered on the emission layer. It can be seen that the heat distribution generated in the presented OLED structure has an asymmetrically high temperature distribution toward the cathode, which is believed to be because the sizes of the cathode and positive electrode are asymmetric. Therefore, when designing OLED, it is believed that designing the structures of the cathode and anode electrodes as symmetrically as possible can ensure uniform heat distribution, maintain uniform luminance of OLED, and extend the lifetime. The thermal distribution of OLED was analyzed using the finite element method according to Comsol 5.2.

An Analysis of Light Induced Degradation with Optical Source Properties in Boron-Doped P-Type Cz-Si Solar Cells (광원의 특성에 따른 Boron-doped p-type Cz-Si 태양전지의 광열화 현상 분석)

  • Kim, Soo Min;Bae, Soohyun;Kim, Young Do;Park, Sungeun;Kang, Yoonmook;Lee, Haeseok;Kim, Donghwan
    • Korean Journal of Materials Research
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    • v.24 no.6
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    • pp.305-309
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    • 2014
  • When sunlight irradiates a boron-doped p-type solar cell, the formation of BsO2i decreases the power-conversion efficiency in a phenomenon named light-induced degradation (LID). In this study, we used boron-doped p-type Cz-Si solar cells to monitor this degradation process in relation to irradiation wavelength, intensity and duration of the light source, and investigated the reliability of the LID effects, as well. When halogen light irradiated a substrate, the LID rate increased more rapidly than for irradiation with xenon light. For different intensities of halogen light (e.g., 1 SUN and 0.1 SUN), a lower-limit value of LID showed a similar trend in each case; however, the rate reached at the intensity of 0.1 SUN was three times slower than that at 1 SUN. Open-circuit voltage increased with increasing duration of irradiation because the defect-formation rate of LID was slow. Therefore, we suppose that sufficient time is needed to increase LID defects. After a recovery process to restore the initial value, the lower-limit open-circuit voltage exhibited during the re-degradation process showed a trend similar to that in the first degradation process. We suggest that the proportion of the LID in boron-doped p-type Cz-Si solar cells has high correlation with the normalized defect concentrations (NDC) of BsO2i. This can be calculated using the extracted minority-carrier diffusion-length with internal quantum efficiency (IQE) analysis.

Development of a Numerical Model for Evaluation of Long-Term Mechanical Degradation of Shotcrete Lining in Tunnels (터널 숏크리트 라이닝의 장기 내구성 저하 평가를 위한 수치모델의 개발)

  • Shin Hyu-Soung;Lim Jong-Jin;Kim Dong-Gyu;Lee Gyu-Phil;Bae Gyu-Jin
    • 한국터널공학회:학술대회논문집
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    • 2005.04a
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    • pp.251-258
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    • 2005
  • In this study, a new concept for simulating a long-term mechanical degradation mechanism of shotcrete in tunnels has been proposed. In fact, it is known that the degradation takes place mainly by internal cracks and reduced stiffness, which results mainly from volume expansion of shotcrete and corrosion of cement materials, respectively. This degradation mechanism of shotcrete in tunnels appears similar to those of the most kinds of chemical reactions in tunnels. Therefore, the mechanical degradation induced by a kinds of chemical reaction was generalized and mathematically formulated in the framework of thermodynamics. The numerical model was implemented to a 3D finite element code, which can be used to simulate behaviour of shotcrete structures undergoing external forces as well as chemical degradation in time. A number of illustrative examples were given to show the feasibility of the model in tunnel designs with consideration of long-term degradation effect of shotcrete quantitatively for increase of long-term safety of tunnels.

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A Study on the Physical Characteristics of the Low-voltage Circuit Breaker Based on the Accelerated Degradation Test (가속 열화 시험에 따른 저압용 차단기의 물리적 특성에 관한 연구)

  • Sin dong, Kang;Jae-Ho, Kim
    • Journal of the Korean Society of Safety
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    • v.37 no.6
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    • pp.1-8
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    • 2022
  • This study analyzed the characteristics of insulation resistance and operating time based on an accelerated degradation test of a low-voltage circuit breaker. The experimental sample used a molded case circuit breaker (MCCB) and an earth leakage circuit breaker (ELCB). After measuring the insulation resistance of the circuit breakers, the leakage current was affected by an external rather than an internal structure. Furthermore, the insulation resistance of the circuit breakers with accelerated degradation was measured using a Megger insulation tester. In the accelerated degradation test, aging times of five, ten, 15, and 20 years were applied according to a temperature derived using the Arrhenius equation. Circuit breakers with an equivalent life of ten, 15, and 20 years had increased insulation resistance compared to those with less degradation time. In particular, the circuit breaker with an equivalent life of ten years had the highest insulation resistance. Component analysis of the circuit breaker manufactured through an accelerated degradation test confirmed that the timing of the increase in insulation resistance and the time of additive loss were the same. Finally, after analyzing the operating time of the circuit breakers with degradation, it was confirmed that the MCCB did not change, but the ELCB breaker failed.