• 제목/요약/키워드: Activators

검색결과 347건 처리시간 0.026초

Adenosine monophosphate-activated protein kinase in diabetic nephropathy

  • Kim, Yaeni;Park, Cheol Whee
    • Kidney Research and Clinical Practice
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    • 제35권2호
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    • pp.69-77
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    • 2016
  • Diabetic nephropathy (DN) is the leading cause of end-stage renal disease, and its pathogenesis is complex and has not yet been fully elucidated. Abnormal glucose and lipid metabolism is key to understanding the pathogenesis of DN, which can develop in both type 1 and type 2 diabetes. A hallmark of this disease is the accumulation of glucose and lipids in renal cells, resulting in oxidative and endoplasmic reticulum stress, intracellular hypoxia, and inflammation, eventually leading to glomerulosclerosis and interstitial fibrosis. There is a growing body of evidence demonstrating that dysregulation of 50 adenosine monophosphate-activated protein kinase (AMPK), an enzyme that plays a principal role in cell growth and cellular energy homeostasis, in relevant tissues is a key component of the development of metabolic syndrome and type 2 diabetes mellitus; thus, targeting this enzyme may ameliorate some pathologic features of this disease. AMPK regulates the coordination of anabolic processes, with its activation proven to improve glucose and lipid homeostasis in insulin-resistant animal models, as well as demonstrating mitochondrial biogenesis and antitumor activity. In this review, we discuss new findings regarding the role of AMPK in the pathogenesis of DN and offer suggestions for feasible clinical use and future studies of the role of AMPK activators in this disorder.

A critical review of slag and fly-ash based geopolymer concrete

  • Akcaoglu, Tulin;Cubukcuoglu, Beste;Awad, Ashraf
    • Computers and Concrete
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    • 제24권5호
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    • pp.453-458
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    • 2019
  • Today, concrete remains the most important, durable, and reliable material that has been used in the construction sector, making it the most commonly used material after water. However, cement continues to exert many negative effects on the environment, including the production of carbon dioxide (CO2), which pollutes the atmosphere. Cement production is costly, and it also consumes energy and natural non- renewable resources, which are critical for sustainability. These factors represent the motivation for researchers to examine the various alternatives that can reduce the effects on the environment, natural resources, and energy consumption and enhance the mechanical properties of concrete. Geopolymer is one alternative that has been investigated; this can be produced using aluminosilicate materials such as low calcium (class F) FA, Ultra-Fine GGBS, and high calcium FA (class C, which are available worldwide as industrial, agricultural byproducts.). It has a high percentage of silica and alumina, which react with alkaline solution (activators). Aluminosilicate gel, which forms as a result of this reaction, is an effective binding material for the concrete. This paper presents an up-to-date review regarding the important engineering properties of geopolymer formed by FA and slag binders; the findings demonstrate that this type of geopolymer could be an adequate alternative to ordinary Portland cement (OPC). Due to the significant positive mechanical properties of slag-FA geopolymer cements and their positive effects on the environment, it represents a material that could potentially be used in the construction industry.

The Plant-Stress Metabolites, Hexanoic Aacid and Melatonin, Are Potential "Vaccines" for Plant Health Promotion

  • Anderson, Anne J.;Kim, Young Cheol
    • The Plant Pathology Journal
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    • 제37권5호
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    • pp.415-427
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    • 2021
  • A plethora of compounds stimulate protective mechanisms in plants against microbial pathogens and abiotic stresses. Some defense activators are synthetic compounds and trigger responses only in certain protective pathways, such as activation of defenses under regulation by the plant regulator, salicylic acid (SA). This review discusses the potential of naturally occurring plant metabolites as primers for defense responses in the plant. The production of the metabolites, hexanoic acid and melatonin, in plants means they are consumed when plants are eaten as foods. Both metabolites prime stronger and more rapid activation of plant defense upon subsequent stress. Because these metabolites trigger protective measures in the plant they can be considered as "vaccines" to promote plant vigor. Hexanoic acid and melatonin instigate systemic changes in plant metabolism associated with both of the major defense pathways, those regulated by SA- and jasmonic acid (JA). These two pathways are well studied because of their induction by different microbial triggers: necrosis-causing microbial pathogens induce the SA pathway whereas colonization by beneficial microbes stimulates the JA pathway. The plant's responses to the two metabolites, however, are not identical with a major difference being a characterized growth response with melatonin but not hexanoic acid. As primers for plant defense, hexanoic acid and melatonin have the potential to be successfully integrated into vaccination-like strategies to protect plants against diseases and abiotic stresses that do not involve man-made chemicals.

The Effect of Product Knowledge and Service Quality on Customer Satisfaction

  • AL IDRUS, Salim;ABDUSSAKIR, Abdussakir;DJAKFAR, Muhammad;AL IDRUS, Shofiyah
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.927-938
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    • 2021
  • Small and Medium Enterprises (SMEs) is one of several activators that drives the economy of Indonesia because SMEs provide jobs, increase Gross Domestic Product (GDP), and assure the delivery of products and services. However, Indonesian SMEs are not very competitive in the industrial world, and one of the causes is the low quality of products that undermine customer satisfaction. There are several factors presumed as influencing customer satisfaction, which among others include product knowledge, service quality, and competitive advantage. The objective of this research is to reveal the contribution of product knowledge and service quality to customer satisfaction with competitive advantage as the mediation variable. This research used a quantitative approach. The causal relationship across variables was examined with Structural Equation Modeling-Partial Least Squares (SEM-PLS). The sample of this research involved 140 respondents. Data was collected through a questionnaire and the items in the questionnaire were processed with a software called SmartPLS version 3.3.2. Results of this research indicate (1) product knowledge and service quality can increase competitive advantage and customer satisfaction in East Java SMEs; (2) competitive advantage can act as a mediator in the effect of service quality on customer satisfaction (3) product knowledge can increase customer satisfaction but the increase is not significant statistically.

DEVELOPMENT OF SUSTAINABLE CEMENTLESS MORTARS

  • Keun-Hyeok Yang;Seol Lee;Sang-Ho Nam
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1630-1636
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    • 2009
  • Nine alkali-activated (AA) mortars were mixed and cured at water or air-dried conditions to explore the significance and limitation for the application of the combination of Ba and Ca ions as an alkali-activator. Ground granulated blast-furnace slag (GGBS) was used for source materials, and calcium hydroxide (Ca(OH)2) and barium hydroxide (Ba(OH)2) were employed as alkali activators. Test results clearly showed that the water curing condition was more effective than the air-dried curing condition for the formation of the denser calcium silicate hydrate (C-S-H) gels that had a higher molar Si/Ca ratio, resulting in a higher strength development. At the same time, the introduction of Ba(OH)2 led to the formation of 2CaO·Al2O3·SiO2·8H2O (C2ASH8) hydrates with higher molar Si/Al and Ca/Al ratios. Based on the test results, it can be concluded that the developed cementless mortars have highly effective performance and high potential as an eco-friendly sustainable building material.

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Mad2B forms a complex with Cdc20, Cdc27, Rev3 and Rev1 in response to cisplatin-induced DNA damage

  • Ju Hwan Kim;Rajnikant Patel
    • The Korean Journal of Physiology and Pharmacology
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    • 제27권5호
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    • pp.427-436
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    • 2023
  • Mitotic arrest deficient 2 like 2 (Mad2L2, also known as Mad2B), the human homologue of the yeast Rev7 protein, is a regulatory subunit of DNA polymerase ζ that shares high sequence homology with Mad2, the mitotic checkpoint protein. Previously, we demonstrated the involvement of Mad2B in the cisplatin-induced DNA damage response. In this study, we extend our findings to show that Mad2B is recruited to sites of DNA damage in human cancer cells in response to cisplatin treatment. We found that in undamaged cells, Mad2B exists in a complex with Polζ-Rev1 and the APC/C subunit Cdc27. Following cisplatin-induced DNA damage, we observed an increase in the recruitment of Mad2B and Cdc20 (the activators of the APC/C), to the complex. The involvement of Mad2B-Cdc20-APC/C during DNA damage has not been reported before and suggests that the APC/C is activated following cisplatin-induced DNA damage. Using an in vitro ubiquitination assay, our data confirmed Mad2B-dependent activation of APC/C in cisplatin-treated cells. Mad2B may act as an accelerator for APC/C activation during DNA damage response. Our data strongly suggest a role for Mad2B-APC/C-Cdc20 in the ubiquitination of proteins involved in the DNA damage response.

Effect of activator types on cement mortar with polymeric aluminum chloride waste residue

  • Ping Xu;Yuhao Cui;Dong Han;Minxia Zhang;Yahong Ding
    • Advances in concrete construction
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    • 제15권3호
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    • pp.149-159
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    • 2023
  • Water glass (WG) and sodium sulfate (SS) were used to prepare polymeric aluminum chloride residue cement mortar (PACRM) by single and compound blending with polymeric aluminum chloride waste residue, respectively. The structural strength and textural characteristics examinations showed that PACRM consistency increased by incorporating WG, but decreased by incorporating SS. When WG and SS were compounded, the mortar consistency initially rose before falling. The compressive strength of PACRM increased and then decreased as WG was increased. The mechanical properties of PACRM were better enhanced by SS than WG, showing no strength deterioration. The main reason for the improved mechanical properties of polymeric aluminum chloride waste residue in the presence of activators is the increased precipitation of reactive substances, such as C-S-H gels, calcium silica, and Ca(OH)2. The density of the specimens with PACRM and the degree of aggregation of hydration products were significantly enhanced by generating more hydration products in the mortar. Further, the cracks and pores were significantly reduced, and the matrix structure was continuous and dense at 5% SS doping and 3% compound doping.

Impaired Autophagic Flux in Glucose-Deprived Cells: An Outcome of Lysosomal Acidification Failure Exacerbated by Mitophagy Dysfunction

  • Eun Seong Hwang;Seon Beom Song
    • Molecules and Cells
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    • 제46권11호
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    • pp.655-663
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    • 2023
  • Autophagy dysfunction is associated with human diseases and conditions including neurodegenerative diseases, metabolic issues, and chronic infections. Additionally, the decline in autophagic activity contributes to tissue and organ dysfunction and aging-related diseases. Several factors, such as down-regulation of autophagy components and activators, oxidative damage, microinflammation, and impaired autophagy flux, are linked to autophagy decline. An autophagy flux impairment (AFI) has been implicated in neurological disorders and in certain other pathological conditions. Here, to enhance our understanding of AFI, we conducted a comprehensive literature review of findings derived from two well-studied cellular stress models: glucose deprivation and replicative senescence. Glucose deprivation is a condition in which cells heavily rely on oxidative phosphorylation for ATP generation. Autophagy is activated, but its flux is hindered at the autolysis step, primarily due to an impairment of lysosomal acidity. Cells undergoing replicative senescence also experience AFI, which is also known to be caused by lysosomal acidity failure. Both glucose deprivation and replicative senescence elevate levels of reactive oxygen species (ROS), affecting lysosomal acidification. Mitochondrial alterations play a crucial role in elevating ROS generation and reducing lysosomal acidity, highlighting their association with autophagy dysfunction and disease conditions. This paper delves into the underlying molecular and cellular pathways of AFI in glucose-deprived cells, providing insights into potential strategies for managing AFI that is driven by lysosomal acidity failure. Furthermore, the investigation on the roles of mitochondrial dysfunction sheds light on the potential effectiveness of modulating mitochondrial function to overcome AFI, offering new possibilities for therapeutic interventions.

The Effect of Glutamine on Production of Tissue-type Plasminogen Activator from Recombinant Human Melanoma Cells in Glutamine-limited Fed-batch Cultivation

  • Kim, Hyun-Goo;Kim, Tae-Ho;Kim, Dae-Seok;Park, Kyung-Yu;Park, jin-seo;Ahn, Chol;Lee, Jin-Ha;Lee, Hyeon-Yong
    • Journal of Microbiology and Biotechnology
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    • 제6권4호
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    • pp.295-298
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    • 1996
  • Under glutamine-limited condition, $2\times10^6$ (viable cells/ml) of maximum cell density and 13.5 ($\mu g$/ml) of tissue-type Plasminogen Activators (tPA) production were maintained by spike feeding fresh medium in fed-batch cultivation of human recombinant melanoma cells. It showed that tPA production was much seriously affected than cell growth according to initial glutamine concentrations. Above 3.4 (mmol/I) of glutamine concentration both cell growth and tPA production were not much affected by increasing initial glutamine concentration. Glutamine depleted situation was occurred at latter periods of batch and fed-batch cultivations below 5.4 (mmole/I) of initial glutamine concentration. It also showed that maximum glutamine consumption and ammonia evolution rates were closely related to initial glutamine concentrations. Maximum specific tPA production rate was estimated as $8.1\times19^{-6}$ ($\mu g$/cells/h) at 3.4(mmol/I) of glutamine concentration, which is higher than that from other batch and fed-batch processes.

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Dieckol, a Component of Ecklonia cava, Suppresses the Production of MDC/CCL22 via Down-Regulating STAT1 Pathway in Interferon-γ Stimulated HaCaT Human Keratinocytes

  • Kang, Na-Jin;Koo, Dong-Hwan;Kang, Gyeoung-Jin;Han, Sang-Chul;Lee, Bang-Won;Koh, Young-Sang;Hyun, Jin-Won;Lee, Nam-Ho;Ko, Mi-Hee;Kang, Hee-Kyoung;Yoo, Eun-Sook
    • Biomolecules & Therapeutics
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    • 제23권3호
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    • pp.238-244
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    • 2015
  • Macrophage-derived chemokine, C-C motif chemokine 22 (MDC/CCL22), is one of the inflammatory chemokines that controls the movement of monocytes, monocyte-derived dendritic cells, and natural killer cells. Serum and skin MDC/CCL22 levels are elevated in atopic dermatitis, which suggests that the chemokines produced from keratinocytes are responsible for attracting inflammatory lymphocytes to the skin. A major signaling pathway in the interferon-${\gamma}$ (IFN-${\gamma}$)-stimulated inflammation response involves the signal transducers and activators of transcription 1 (STAT1). In the present study, we investigated the anti-inflammatory effect of dieckol and its possible action mechanisms in the category of skin inflammation including atopic dermatitis. Dieckol inhibited MDC/CCL22 production induced by IFN-${\gamma}$ (10 ng/mL) in a dose dependent manner. Dieckol (5 and $10{\mu}M$) suppressed the phosphorylation and the nuclear translocation of STAT1. These results suggest that dieckol exhibits anti-inflammatory effect via the down-regulation of STAT1 activation.