• Herbal Formula Science
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• v.30 no.4
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• pp.293-304
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• 2022

Objectives : Sagunja-Tang is a famous prescription used in Korean medicine for the purpose of promoting vital energy, and there are few studies using Sagunja-Tang on cerebrovascular diseases yet. As previous studies confirmed that Sagunja-tang is highly likely to be used effectively for stroke, this study was intended to predict the mechanism through which Sagunja-tang would act effectively on stroke. Methods : In this study, a network pharmacology analysis method was used, and oral bioavailability (OB), drug likeness (DL), Caco-2 and BBB permeability were utilized to select compounds with potential activity. For the values of each variable used in this study, OB ≥ 30%, DL ≥ 0.18, Caco-2 ≥ 0, and BBB ≥ 0.3 were applied. Using the above variables, the relations between target genes and diseases that are presumed to be involved in the selected bioavailable compounds were constructed in a network format, and proteins thought to play a major role were identified. Results : Among the compounds included in Sagunja-Tang, 26 bioavailable compounds were selected and it was confirmed that these compounds can be effectively used in cerebrovascular diseases such as Alzheimer's disease and stroke. These compounds are considered to act on proteins related in cell death and growth. The most important mechanism of action was predicted to be apoptosis, and the protein that is thought to play the most key action in this mechanism was caspase-3. Conclusions : In our future study, Sagunja-Tang will be used in an ischemic stroke mouse model, and the mechanism of action will be explored focusing on apoptosis and cell proliferation.

• Resources Recycling
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• v.31 no.5
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• pp.3-19
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• 2022

Electro-membrane technology is a process for separating and purifying substances in aqueous solution by electric energy using an ion exchange membrane with selective permeability, such as electrodialysis (ED) and bipolar electrodialysis (BMED). Electro-membrane technology is attracting attention as an environmental friendly technology because it does not generate by-products during the process and the recovered base or acid can be reused during the process. In this paper, we investigate the principles of ED and BMED technologies and various characteristics and problems according to the cell configuration. In particular, by investigating and analyzing research cases related to the treatment of waste sodium sulfate (Na₂SO₄), which is generated in large amounts during the metal recovery process.

• Composites Research
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• v.36 no.6
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• pp.422-428
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• 2023

The electrical contact resistance between the bipolar plate (BP) and the carbon felt electrode (CFE), which are in contact by the stack clamping pressure, has a great impact on the stack efficiency because of the relatively low clamping pressure of the vanadium redox flow battery (VRFB) stack. In this study, a polyethylene (PE) composite-CFE hybrid bipolar plate structure is developed through a local heat welding process to reduce such contact resistance and improve cell performance. The PE matrix of the carbon fiber composite BP is locally melted to create a direct contact structure between the carbon fibers of CFE and the carbon fibers of BP, thereby reducing the electrical contact resistance. Area specific resistance (ASR) and gas permeability are measured to evaluate the performance of the PE composite-CFE hybrid bipolar plate. In addition, an acid aging test is performed to measure stack reliability. Finally, a VFRB unit cell charge/discharge test is performed to compare and analyze the performance of the developed PE composite-CFE hybrid BP and the conventional BP.

• Food Science of Animal Resources
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• v.36 no.3
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• pp.421-426
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• 2016

Polylactic acid (PLA) is a biodegradable and renewable polymer, which represents a valuable alternative to plastic packaging films, often associated with environmental problems. In this study, we tested the suitability of PLA as a biodegradable packaging film and assessed the antimicrobial activity of lemongrass oil (LO), incorporated into the PLA film in different concentrations. To obtain the optimal physical properties for PLA films, tensile strength, elongation at break, and water vapor permeability were measured under different preparation conditions. In addition, the antimicrobial activity of the LO contained in the PLA film against Listeria monocytogenes was investigated by disc diffusion and viable cell count. Among all concentrations tested, 2% LO was the most suitable in terms of antimicrobial activity and physical properties of the PLA film. Based on these results, we used the PLA film containing 2% LO to pack pork sausages; after 12 d of storage at 4℃, the population of inoculated L. monocytogenes in the sausage samples wrapped with the PLA film containing 2% LO was reduced by 1.47 Log CFU/g compared with the control samples. Our data indicate that PLA films containing 2% LO represent a valuable means for antimicrobial sausage packaging.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.80.2-80.2
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• 2010

The development of high temperature-proton exchange fuel cell (HT-PEFC) is a key in solving the problem of carbon monoxide poisoning of the platinum at anode as well as water management in PEFCs operated below $90^{\circ}C$. In order to overcome these main issues, PEFCs must be operated at high temperature above $120^{\circ}C$. Ionic liquids are available for HT-PEFC due to exhibiting non-volatility and thermal stability. Ionic liquids are however leached out from polymeric matrix resulting in the increase of gas permeability. In this study, we have prepared and characterized the composite membranes with the ionic liquids consisting of 1-(4-vinylbenzyl)-3-butyl imidazolium chloride immobilized by the cross-linkers in pore-filling membrane to prevent to be leached out from the membrane. We confirmed that cross-linked ionic liquids were not leached out from the composite membranes through the various characteristic analyses. It was also verified that the prepared membranes are thermally stable from the result of TG analysis. The pore-filling membranes with the immobilized ionic liquids have a high proton conductivity over $10^{-2}$ S/cm at high temperature (> $120^{\circ}C$).

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1645-1649
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• 2011

[ ${\beta}$ ]Ketoacyl acyl carrier protein synthase I (KAS I) is involved in the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and a therapeutic target of designing novel antibiotics. In this study, we performed receptor-oriented pharmacophore-based in silico screening of E. coli KAS I (ecKAS I) with the aim of identifying novel inhibitors. We determined one pharmacophore map and selected 8 compounds as candidates ecKAS I inhibitors. We discovered one antimicrobial compound, YKAe1008, N-(3-pyridinyl) hexanamide, displaying minimal inhibitory concentration (MIC) values in the range of 128-256 ${\mu}g/mL$ against MRSA and VREF. YKAe1008 was subsequently assessed for binding to ecKAS I using saturation-transfer difference NMR spectroscopy. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.382-390
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• 2020

Periplanetasin-4 is an antimicrobial peptide with 13 amino acids identified in cockroaches. It has been reported to induce fungal cell death by apoptosis and membrane-targeted action. Analogs were designed by substituting arginine residues to modify the electrostatic and hydrophobic interactions accordingly and explore the effect of periplanetasin-4 through the increase of net charge and the decrease of hydrophobicity. The analogs showed lower activity than periplanetasin-4 against gram-positive and gram-negative bacteria. Similar to periplanetasin-4, the analogs exhibited slight hemolytic activity against human erythrocytes. Membrane studies, including determination of changes in membrane potential and permeability, and fluidity assays, revealed that the analogs disrupt less membrane integrity compared to periplanetasin-4. Likewise, when the analogs were treated to the artificial membrane model, the passage of molecules bigger than FD4 was difficult. In conclusion, arginine substitution could not maintain the membrane disruption ability of periplanetasin-4. The results indicated that the attenuation of hydrophobic interactions with the plasma membrane caused a reduction in the accumulation of the analogs on the membrane before the formation of electrostatic interactions. Our findings will assist in the further development of antimicrobial peptides for clinical use.

• Biomedical Science Letters
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• v.10 no.2
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• pp.93-98
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• 2004

The effects of intravenously administered of high concentration of taurocholic acid (TCA) on $\alpha$-D- and $\beta$-D-mannosidase activities in rat liver lysosomes were studied. These liver lysosomal enzymes, and serum lysosomal $\alpha$-D- and $\beta$-D-mannosidase isozymes activities were determined in experimental rats with common bile duct ligation (CBDL). The liver lysosomal $\beta$-D-mannosidase activity as well as the serum lysosomal $\alpha$-D- and $\beta$-D-mannosidase isozymes activities were found to be significantly increased in the CBDL plus TCA injected group than in the control group such as CBDL alone group. However, the liver lysosomal $\alpha$-D-mannosidase activity was found to be significantly decreased in the CBDL plus TCA injected group. The above results suggest that TCA repress the biosynthesis of the lysosomal $\alpha$-D-mannosidase and induce the biosynthesis of the lysosomal $\beta$-D-mannosidase in the liver. And that the elevated serum lysosomal $\alpha$-D- and $\beta$-D-mannosidase isozymes activities are most likely due to increased hepatocyte membrane permeability caused by TCA mediated liver cell necrosis.

• Biomedical Science Letters
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• v.12 no.2
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• pp.91-97
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• 2006

The effects of intravenous administration of high concentration of taurocholic acid (TCA) on monoamine oxidase (MAO) A and B activities in rat liver mitochondria and microsomes were studied. These liver subcellular organelles and serum MAO activities were determined from the experimental rats with choledocho-caval shunt (CCS). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and microsomal MAO B as well as their $V_{max}$ values were found to be decreased significantly in CCS plus TCA injected group then in the control group, such as CCS alone groups. However their $K_m$ values in the experimental groups did not vary. MAO of serum appeared in the CCS plus TCA injected groups only. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The MAO of serum is believed to be caused by the increment of membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.

• Biomedical Science Letters
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• v.13 no.2
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• pp.135-140
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• 2007

The possible mechanism of decreased catechol-O-methyltransferase (COMT) activity in cholestatic rat liver was studied. Hepatic and serum COMT activities were determined from the experimental rats with choledocho-caval shunt (CCS). The Michaelis-Menten constants in this hepatic enzyme was also measured. The activities of cytosolic, mitochondrial and mircosomal COMT as well as their $V_{max}$ values were found to be decreased significantly in CCS plus taurocholic acid (TCA) injected group than in the control group, such as CCS alone groups. However, their $K_m$ values in the experimental groups did not vary. Seru4m COMT activity increased slightly in the CCS plus TCA injerted group than in the control group. The above results suggest that TCA represses biosynthesis of the COMT in the liver, The elevated activity of the serum COMT is believed to be caused by the increment of membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.