• International Journal of Computer Science & Network Security
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• v.22 no.7
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• pp.199-205
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• 2022

The extensive growth in data rate demand by the smart gadgets and mobile broadband application services in wireless cellular networks. To achieve higher data rate demand which leads to aggressive frequency reuse to improve network capacity at the price of Inter Cell Interference (ICI). Fractional Frequency Reuse (FFR) has been recognized as an effective scheme to get a higher data rate and mitigate ICI for perfect geometry network scenarios. In, an irregular geometric multicellular network, ICI mitigation is a challenging issue. The purpose of this paper is to develop distributed dynamic power allocation scheme for FFR based on game theory to mitigate ICI. In the proposed scheme, each cell region in an irregular multicellular scenario adopts a self-less behavior instead of selfish behavior to improve the overall utility function. This proposed scheme improves the overall data rate and mitigates ICI.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.359-366
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• 2021

Neuromesodermal progenitors (NMPs) constitute a bipotent cell population that generates a wide variety of trunk cell and tissue types during embryonic development. Derivatives of NMPs include both mesodermal lineage cells such as muscles and vertebral bones, and neural lineage cells such as neural crests and central nervous system neurons. Such diverse lineage potential combined with a limited capacity for self-renewal, which persists during axial elongation, demonstrates that NMPs are a major source of trunk tissues. This review describes the identification and characterization of NMPs across multiple species. We also discuss key cellular and molecular steps for generating neural and mesodermal cells for building up the elongating trunk tissue.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.8 no.2
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• pp.119-128
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• 2022

2-Dimensional inorganic nanoparticles with high surface area and ion-exchangeable properties have been continuously growing based on nanotechnology in the field of nanomedicine. Among one of the 2-D nanoparticles, layered double hydroxide (LDH) has been intensively explored as drug delivery due to its low toxicity, enhanced cellular permeability, and high drug loading capacity. Moreover, controllable chemical composition makes possible varying isomorphic layered materials for therapy and imaging of diseases. In this review, specific structural characteristics of LDH were introduced, and its potential for application as a biocompatible therapeutic agent and diagnostic one was addressed in nuclear medicine, one of promising fields in nanomedicine.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.992-997
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• 2023

Ferroptosis is a new kind of programmed cell death of which occurrence in microorganisms is not clearly verified. The elevated level of reactive oxygen species (ROS) influences cellular metabolisms through highly reactive hydroxyl radical formation under the iron-dependent Fenton reaction. Iron contributes to ROS production and acts as a cofactor for lipoxygenase to catalyze poly unsaturated fatty acid (PUFA) oxidation, exerting oxidative damage in cells. While ferroptosis is known to take place only in mammalian cells, recent studies discovered the possible ferroptosis-like death in few specific microorganisms. Capacity of integrating PUFA into intracellular membrane phospholipid has been considered as a key factor in bacterial or fungal ferroptosis-like death. Vibrio species in bacteria and Saccharomyces cerevisiae in fungi exhibited certain characteristics. Therefore, this review focus on introducing the occurrence of ferroptosis-like death in microorganisms and investigating the mode of action underlying the cells based on contribution of lipid peroxidation and iron-dependent reaction.

• Biomolecules & Therapeutics
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• v.32 no.2
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• pp.183-191
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• 2024

The Unfolded Protein Response (UPR) serves as a critical cellular mechanism dedicated to maintaining protein homeostasis, primarily within the endoplasmic reticulum (ER). This pathway diligently responds to a variety of intracellular indicators of ER stress with the objective of reinstating balance by diminishing the accumulation of unfolded proteins, amplifying the ER's folding capacity, and eliminating slow-folding proteins. Prolonged ER stress and UPR irregularities have been linked to a range of neuropsychiatric disorders, including major depressive disorder, bipolar disorder, and schizophrenia. This review offers a comprehensive overview of the UPR pathway, delineating its activation mechanisms and its role in the pathophysiology of neuropsychiatric disorders. It highlights the intricate interplay within the UPR and its profound influence on brain function, synaptic perturbations, and neural developmental processes. Additionally, it explores evolving therapeutic strategies targeting the UPR within the context of these disorders, underscoring the necessity for precision and further research to effective treatments. The research findings presented in this work underscore the promising potential of UPR-focused therapeutic approaches to address the complex landscape of neuropsychiatric disorders, giving rise to optimism for improving outcomes for individuals facing these complex conditions.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.217-226
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• 2016

In this study, we investigated the antioxidative and cellular protective effects on HaCaT cells and erythrocytes of Moringa oleifera (M. oleifera) leaves extract and its fractions. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction of M. oleifera leaves. The free radical scavenging activity ($FSC_{50}$) of the extract and fractions of M. oleifera leaves were in the following order: 50% ethanol extract ($77.10{\mu}g/mL$) < ethyl acetate fraction ($20.63{\mu}g/mL$) < aglycone fraction ($17.00{\mu}g/mL$) by using the 1, 1-diphenyl-2-picrylhydrazyl. In $Fe^{3+}-EDTA/H_2O_2$ system using the luminol, reactive oxygen species (ROS) scavenging activities (total antioxidant capacity, $OSC_{50}$) of aglycone fraction ($OSC_{50}=0.63{\mu}g/mL$) was the strongest among all extracts, which was much higher than L-ascorbic acid ($1.50{\mu}g/mL$). In the $^1O_2$-induced cellular damage of erythrocytes, the cellular protective effects of 50% ethanol extract (${\tau}_{50}=46.9min$) and aglycone fraction (${\tau}_{50}=122.1min$) were higher than (+)-${\alpha}$-tocopherol (${\tau}_{50}=37.7min$), known as a lipophilic antioxidant at $10{\mu}g/mL$. After cell damage induced by $400mJ/cm^2$ UVB irradiation, the cellular protective effects of ethyl acetate and aglycone fraction of M. oleifera leaves extract were showed on the concentration from 0.20 to $1.56{\mu}g/mL$. These results suggest that M. oleifera leaves extract and its fractions can function as a natural antioxidant agent in cosmetics on skin exposed to UV radiation by protecting cellular membrane against ROS.

• Toxicological Research
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• v.23 no.2
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• pp.143-150
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• 2007

Although animal and epidemiological studies have suggested oxidative stress as an etiological factor in pathogenesis including cancer, inflammation, sepsis, fibrosis, cardiovascularlneurodegenerative diseases and aging-related disorders, conflicting results have been obtained in clinical trial with antioxidants. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating antioxidant capacity. The antioxidant activity of a series of sugar alcohols against peroxyl radicals, hydroxyl radicals and peroxynitrites was determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. Specific TOSC values calculated from the slope of the linear regression for erythritol, xylitol, sorbitol or mannitol against peroxyl radicals was $2.1{\pm}0.2,\;3.7{\pm}0.3,\;9.1{\pm}0.3$ or $8.7{\pm}1.1$ TOSC/mM, respectively. Specific TOSC values for erythritol, xylitol, sorbitol or mannitol against peroxynitrite was $1.9{\pm}0.3,\;3.9{\pm}0.4,\;7.8{\pm}0.7$ or $7.7{\pm}0.5$ TOSC/mM, respectively. These results suggest that oxy-radical scavenging capacity is dependent on the number of aliphatic hydroxyl group in sugar alcohols of monosaccharide. Tert-butylhydroperoxide (t-BHP)-induced cell toxicity determined by MTT assay was marginally attenuated by 10 mM erythritol, but completely inhibited by 10 mM xylitol, 2 mM sorbitol or 0.75 mM maltitol, a disaccharide alcohol. Oxidative stress markers, such as glutathione (GSH) and malondial-dehyde (MDA) levels, were measured in t-BHP-treated cells using HPLC equipped with a fluorescence detector and a reverse phase column. Erythritol did not change the levels of GSH and MDA in H411E cells treated with t-BHP. The t-BHP-induced changes in cellular GSH and MDA levels were ameliorated by 10 mM xylitol and completely blocked by 10 mM sorbitol and maltitol. These results indicate that sugar alcohols protect cells against oxidative stress via scavenging oxy-radical and suggest that TOSC assay in conjunction with cell-based assay is a valid method for evaluating antioxidant capacity of natural and synthetic chemicals.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.190-198
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• 2007

Alzheimer's disease, a representative neurodegenerative disorder, is characterized by the presence of senile plaques and neurofibrillary tangles accompanied by neuronal damages. b-Amyloid peptide is considered to be responsible for the formation of senile plagues that accumulate in the brains of patients with Alzheimer's disease. There has been compelling evidence supporting that b-amyloid-induced cytotoxicity is mediated through generation of reactive oxygen species. In this study, we have investigated the possible protective effect of Rehmannia glutihosaagainst b-amyloid-induced oxidative ceil death in cultured human neuroblastoma SH-SY5Y cells. SH-SY5Y cells treated with b-amyloid underwent apoptotic death as determined by morphological features and positive in situterminal end-labeling (TUNEL staining). Rehmannia glutinosawater extract, wine, and vinegar pretreatments attenuated b-amyloid-induced cytotoxicity and apoptosis. Rehmannia glutinosa vinegar exhibited maximum protective effect by increasing the expression of anti-apoptotic protein, Bcl-2. in addition to oxidative stress, b-amyloid-treatment caused nitrosative stress via marked increase in the levels of nitric oxide, which was effectively blocked by Rehmannia glutinosa. To further explore the possible molecular mechanisms underlying the protective effect of Rehmannia glutinosa, we assessed the mRNA expression of cellular antioxidant enzymes. Treatment of Rehmannia glutinosa vinegar led to up-regulation of heme oxygemase-1 and catalase. These results suggest that Rehmannia glutinosa could modulate oxidative neuronal cell death caused by b-amyloid and may have preventive or therapeutic potential in the management of Alzheimer's disease. Particularly, Rehmannia glutinosa vinegar can augment cellular antioxidant capacity, there by exhibiting higher neuroprotective potential.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4A
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• pp.237-244
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• 2012

There is mounting recognition among concrete researchers that fiber reinforcement makes up for the inherent weakness in resisting tensile force of structural concrete. In practice of application of the fiber to concrete, however, several problems still remain to solve for assuring a uniform mix quality. The Kagome truss that is widely used in mechanical engineering field seems to be a good replacement for the steel fiber. This paper presents the test results of a pilot study for the concrete members reinforced by Kagome truss which is a periodic cellular metal of wire-woven. Three types of Kagome truss bulk were prefabricated and filled with normal concrete to make small-scaled test beams. The beams reinforced by a normal steel stirrups were also tested up to failure to compare the behavioral results. From the results obtained, it is appeared that comparing with beams reinforced by normal stirrups, the beams reinforced by Kagome truss showed better performance in load carrying capacity as well as ductility. Therefore, the Kagome truss is proved to be a good web shear reinforcing material.

• The Korean Journal of Food And Nutrition
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• v.22 no.2
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• pp.313-319
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• 2009

To improve the growth of human mesenchymal stem cells(hMSCs) under general cell culture conditions(20% $O_2$ and 5% $CO_2$), we examined the effect of s-allylcysteine(SAC), which is known as an antioxidant and the main component of aged-garlic extract, on hydrogen peroxide-induced cellular stress in hMSCs. We found that SAC blocked hydrogen peroxideinduced cell death and cellular apoptosis, but that SAC did not improve the growth of hMSCs during short-term culture. To evaluate the protective effect of SAC, we examined the endogenous expression of the antioxidant enzymes catalase (CAT), superoxide dismutase(SOD), and glutathione peroxidase(Gpx) in hMSCs. Hydrogen peroxide was found to downregulate the expression of CAT, SOD, and Gpx at the protein level. However, in the pre-treatment group of SAC, SAC inhibited the hydrogen peroxide-induced down-regulation of CAT, SOD, and Gpx. Unfortunately, treatment with SAC alone did not induce the up-regulation of antioxidant enzymes and the cell proliferation of hMSCs. Surprisingly, SAC improved cell growth in a single cell level culture of hMSCs. These results indicate that SAC may be involved in the preservation of the self-renewal capacity of hMSCs. Taken together, SAC improves the proliferation of hMSCs via inhibition of oxidative-stress-induced cell apoptosis through regulation of antioxidant enzymes. In conclusion, SAC may be an indispensable component in an in vitro culture system of human MSCs for maintaining self-renewal and multipotent characterization of human MSCs.