• Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.189-201
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• 2022

Jellyfish is an emerging aquaculture species, farmed for Oriental cuisines and nutraceutical ingredients. This study aimed to examine antioxidative and antimicrobial potentials of various fractions of the jellyfish, Acromitus hardenbergi. The bell and oral arms of the jellyfish were sequentially extracted with petroleum ether (PE), dichloromethane (DCM), chloroform (CHCl₃), methanol (MeOH), and water (H₂O) to extract its bioactive in an increasing polarity gradient. Test fractions were assayed for antiradical activities using electron spin resonance spectrometry, β-carotene-linoleate model and Folin-Ciocalteu assay; and antimicrobial activity against 2 Gram-negative bacteria, 4 Gram-positive bacteria and 2 fungal species using the disc diffusion assay. All fractions were also subjected to Fourier Transform Infrared (FTIR) analysis to identify types of functional groups present. It was found that the hydrophilic extracts (H₂O fractions) possessed the most effective radical scavenging activity (p < 0.05) while the lipophilic extracts (PE fractions) the most active antimicrobial activity, especially against Gram-positive bacteria (p < 0.05). Total oxidation substrates content was found to be highest in the PE fractions of jellyfish bell and oral arms (p < 0.05). FTIR data showed that the H₂O and MeOH fractions contains similar functional groups including -OH, -C=O, -N-H and -S=O groups, while the PE, DCM, and CHCl₃ fractions, the -CH₃, -COOH groups. This study showed that A. hardenbergi contains antioxidants and antimicrobials, thereby supporting the traditional claim of the jellyfish as an anti-aging and health-promoting functional food. Bioassay-guided fractionation approach serves as a critical milestone for the strategic screening, purification, and elucidation of therapeutically significant actives from jellyfish.

• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.241-246
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• 2016

The object of this study was to develop an alternative way to treat human skin pathogens using marine algae. During this study, we observed that the ethanolic extract of the edible brown algae [Sargassum serratifolium (C. Agardh) C. Agardh] exhibited potential antimicrobial activity against pathogenic commensal bacteria related with acne vulgaris (Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa), and Candida albicans which causes cutaneous candidiasis. Among the solvent-soluble fractions from the ethanolic extract, a hexane-soluble fraction showed the strongest antimicrobial activity against all tested human skin pathogens with MIC values ranging from 32 to $512{\mu}g/mL$. In addition, the hexane fraction exhibited a synergistic antimicrobial activity with commercial antibiotics used in the treatment of acne vulgaris or cutaneous candidiasis. Thus, this study suggests that S. serratifolium extract could be a potential source of natural antimicrobial agents or a pharmaceutical component against human skin pathogens.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.472-478
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• 2013

Cu and Cr as a base metal and Pt, Pd as a supportive metal were selected for improving adsorption capacity of activated carbon fiber in eliminating especially targeted VOCs. Preparing variables such as metal loading, loading temperature, loading hours and kinds of loaded metals were changed. Properties measurement was carried out by SEM (scanning electron microscope), XRF (x-ray fluorescence analysis) and EDX (Energy Dispersive X-ray spectrometer) and adsorption capacity evaluation were also performed by gas analyzer. Under this study, the adsorption capacity of complex metal loaded activated carbon fiber was improved positively than that of single metal loaded activated carbon fiber. And we found that the best conditions for metal loading were 5 hours loading time at $100^{\circ}C$ and the adsorption capacity was enhanced almost double compared with other condition based activated carbon fiber. Cu-Cr-Pt-Pd loaded activated carbon fiber showed the best adsorption capacity. Also we confirmed that more than 0.5 second is necessary for adsorbate diffusion and adsorption over activated carbon fiber.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3061-3070
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• 2012

Novel 2-hexylthieno[3,2-b]thiophene-containing conjugated molecules have been synthesized via a reduction reaction using tin chloride in an acidic medium. They exhibited good solubility in common organic solvents and good self-film and crystal-forming properties. The single-crystalline objects were fabricated by a solvent slow diffusion process and then were employed for fabricating field-effect transistors (FETs) along with thinfilm transistors (TFTs). TFTs made of 5 and 6 exhibited carrier mobility as high as 0.10-0.15 $cm^2V^{-1}s^{-1}$. The single-crystal-based FET made of 6 showed 0.70 $cm^2V^{-1}s^{-1}$ which was relatively higher than that of the 5-based FET (${\mu}=0.23cm^2V^{-1}s^{-1}$). In addition, we fabricated organic photovoltaic (OPV) cells with new 2-hexylthieno [3,2-b]thiophene-containing conjugated molecules and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester ($PC_{61}BM$) without thermal annealing. The ternary system for a bulk heterojunction (BHJ) OPV cell was elaborated using $PC_{61}BM$ and two p-type conjugated molecules such as 5 and 7 for modulating the molecular energy levels. As a result, the OPV cell containing 5, 7, and $PC_{61}BM$ had improved results with an open-circuit voltage of 0.90 V, a short-circuit current density of 2.83 $mA/cm^2$, and a fill factor of 0.31, offering an overall power conversion efficiency (PCE) of 0.78%, which was larger than those of the devices made of only molecule 5 (${\eta}$~0.67%) or 7 (${\eta}$~0.46%) with $PC_{61}BM$ under identical weight compositions.

• Archives of Pharmacal Research
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• v.20 no.1
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• pp.1-6
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• 1997

We determined the microviscosity of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex and liposomes of total lipids (SPMTL) and phospholipids (SPMPL) extracted from SPMV. Changes in the microviscosity induced by the range and rate of lateral diffusion were measured by the intramolecular excimerization of 1, 3-di(1-pyrenyl)propane (Py-3-Py). The microviscosity values of the direct probe environment in SPMV, SPMTL and SPMPL were 38.17, 31.11 and 27.64 cP, respectively, at$37^{\circ}C$and the activation energies $(E_a)$ of the excimer formation of Py-3-Py in SPMV, SPMTL and SPMPL were 8.236, 7.448 amd 7.025 kcal/mol, respectively. Probe location was measured by polarity and polarizability parameters of the probe Py-3-Py and probe analogues, pyrene, 1-pyrenenonanol and 1-pyrenemethyl-3${\beta}$-hydroxy-22, 23-bisnor-5-cholenate (PMC), incorporated into membranes or solubilized in reference solvents. There existed a good linear relationship between the first absorption peak of the $^1_a$ band and the polarizability parameter $(n^{2}-1)/(2n^{2}+1)$.The calculated refractive index values for SPMV, SPMTL and SPMPL were close to 1.50, which is higher than that of liquid paraffin (n=l.475). The probe location was also determined by using a polarity parameter $(f-1/2f^{I})$. Here f=$({\varepsilon}-1)/(2{\varepsilon}+1)$ is the dielectric constant function and $f^I=(n^2-1)/(2n^2+1)$ is the refractive index function. A correlation existed between the monomer fluorescence intensity ratio and the solvent polarity parameter. The probes incorporated in SPMV, SPMTL, and SPMPL report a polarity value close to that of 1-hexanol $({\varepsilon}=13.29)$. In conclusion, Py-3-Py is located completely inside the membrane, not in the very hydrophobic core, but displaced toward the polar head groups of phospholipid molecules, e.g., central methylene region of aliphatic chains of phospholipid molecules.

• Food Science and Preservation
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• v.12 no.5
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• pp.470-475
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• 2005

Antimicrobial activities of pyroligneous liquor were investigated by determining Minimal Inhibitory Concentration (MIC). The solvent extracts of pyroligneous liquor, which were extracted by using solvents with different polarities such as hexane, ethylacetate, or butanol. The activities were examined by disc diffusion method using MIC against 7 food poisoning microbe type strains. Antimicrobial activities were shown in hexane, ethylacetate, butanol, and aqueous fractions of pyroligneous liquor. Among the four fractions, ethylacetate fraction showed the highest inhibitory effect on the microorganism such as Shigella sonnei, and Yersinia enterocolitica at the concentration of 2.0 mg/disc. The purified P-1 and P-2 fractions isolated by silica gel column chromatography from ethylacetate fraction of pyroligneous liquor had the highest antimicrobial activity. The total phenolic compounds content in ethylacetate, hexane, butanol, and aqueous fraction was 488.3 mg/g, 403.8 mg/g, 83.6mg/g, and 74.5 mg/g, respectively. Taken together, these results suggest that the ethyl acetate fraction could be suitable for the development of isolation and identification of antimicrobial compound from pyroligneous liquor, resulting from the above antimicrobial activity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.3
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• pp.95-100
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• 2006

Synthesis of the non-swelling property micas was carried out by hydrothermal method. In order to artificially induce the diffusion of ions, a rotating system was attached to the hydrothermal apparatus and by adding 0.7 mm zircon beads, synthesis of the non-swelling property micas could be performed in a low temperature area. The hydrothermal conditions for the preparation of micas were a reaction temperature of $260^{\circ}C$, for 72 hrs, using $1K_2O,\;1Al(OH)_3,\;4Mg(OH)_2\;and\;6SiO_2$ as the starting materials and a 8M-KOH solution as the hydrothermal solvent. The micas obtained under these conditions were a plate shape with a size of $2.89{\mu}m$ and showed a whiteness of over 97 %. Also, through the FT-IR analysis, because the absorption peak of the $Mg_3OH$ vibration was observed at approximately $3700cm^{-1}$, it could be known that it was phlogopite of non-swelling property showing the chemical composition of $KMg_3AlSi_3O_{10}(OH)_2$. This result was very consistent with the EDS analysis where O (41.34 %), Mg (3.88 %), Al (11.45 %), Si (17.62 %) and K (25.71%) elements were detected.

• Korea-Australia Rheology Journal
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• v.17 no.3
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• pp.131-140
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• 2005

In this work we show the results of our most recent Direct Numerical Simulations (DNS) of turbulent viscoelastic channel flow using spectral spatial approximations and a stabilizing artificial diffusion in the viscoelastic constitutive model. The Finite-Elasticity Non-Linear Elastic Dumbbell model with the Peterlin approximation (FENE-P) is used to represent the effect of polymer molecules in solution, The corresponding rheological parameters are chosen so that to get closer to the conditions corresponding to maximum drag reduction: A high extensibility parameter (60) and a moderate solvent viscosity ratio (0.8) are used with two different friction Weissenberg numbers (50 and 100). We then first find that the corresponding achieved drag reduction, in the range of friction Reynolds numbers used in this work (180-590), is insensitive to the Reynolds number (in accordance to previous work). The obtained drag reduction is at the level of $49\%\;and\;63\%$, for the friction Weissenberg numbers 50 and 100, respectively. The largest value is substantially higher than any of our previous simulations, performed at more moderate levels of viscoelasticity (i.e. higher viscosity ratio and smaller extensibility parameter values). Therefore, the maximum extensional viscosity exhibited by the modeled system and the friction Weissenberg number can still be considered as the dominant factors determining the levels of drag reduction. These can reach high values, even for of dilute polymer solution (the system modeled by the FENE-P model), provided the flow viscoelasticity is high, corresponding to a high polymer molecular weight (which translates to a high extensibility parameter) and a high friction Weissenberg number. Based on that and the changes observed in the turbulent structure and in the most prevalent statistics, as presented in this work, we can still rationalize for an increasing extensional resistance-based drag reduction mechanism as the most prevalent mechanism for drag reduction, the same one evidenced in our previous work: As the polymer elasticity increases, so does the resistance offered to extensional deformation. That, in turn, changes the structure of the most energy-containing turbulent eddies (they become wider, more well correlated, and weaker in intensity) so that they become less efficient in transferring momentum, thus leading to drag reduction. Such a continuum, rheology-based, mechanism has first been proposed in the early 70s independently by Metzner and Lamley and is to be contrasted against any molecularly based explanations.

• The Korean Journal of Physiology
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• v.28 no.1
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• pp.79-90
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• 1994

The objective of the present study is to assess the contribution of bulk flow to the regulatory mechanism of amniotic fluid volume and its ionic concentration in the membranes surrounding the amniotic fluid. For quantitative assessment, we prepared 4 kinds of artificial amniotic fIuids (isotonic isovolumetric, hypotonic isovolumetric, isotonic hypervolumetric and hypotonic hypervolumetric ones) by replacing 70% of amniotic fluid of pregnant rabbits with water or normal Tyrode solutions. Isoosmotic saline of 0.5 ml volume containing 0.05% Censored and 15 mM/l LiCl was administered initially into amniotic sacs of all subject animals. Samples of amniotic fluid were collected in after 30 and 90 minute intervals; the concentrations of Censored, $Na^+\;and\;Li^+$ were determined and compared. Followings are the results obtained. 1. from isovolumetric and increased Congcord group, we couldn't find significant change in $Li^+\;and\;Na^+$ concentration in isotonic amniotic fluid. However, $Na^+$ concentration increased significantly as well as a striking increase in Censored concentration in hypotonic amniotic fluid. 2. In isovoIumetric and decreased Censored group, the rate of $[Li^+]$ decrement and the rate of $[Na^+]$ increment were much higher in hypotonic amniotic fluid than in isotonic. 3. In hypervolumetric and increased Censored group, the rate of $Na^+$ efflux increased proportionately with the increment of Censored concentration up to 0.98, which was higher than the rate of $Li^+$ efflux in isotonic amniotic fluid. However, the increment of $Na^+$ concentration was rather related with the initial $Na^+$ concentration in hypotonic amniotic fluid, showing inverse relationship. $Li^+$ concentration increased only when there was a marked increase in Censored concentration and approached near a maximum value or 1. 4. For hypervolumetric and decreased Censored group, the observations were identical to isovolumetric and decreased Censored group. From these results the following conclusions could be made: 1) There is no net movement of water or monovalent cations across the membranes surrounding amniotic fIuid in isotonic isovolumetric condition. In contrast, there is a net efflux of amniotic fluid by osmotic bulk flow, resulting in elevation of $Na^+$ concentration in hypotonic isovolumetric condition. 2) In hypervolumetric conditions, there is a massive efflux of amniotic fluid or solvent drag through the surrounding membranes by fiItrative bulk flow, where the rate of $Na^+$ efflux has a linear relationship with that of water efflux. This is assumed to be carried out through enlarged and newly opened intercellular spaces resulting from increased intraamniotic pressure. 3) Once increasing intraamniotic pressure reaches a point allowing $Li^+$ to pass through during osmotic bulk flow in hypotonic amniotic fIuid, $Na^+$ influx seems to occur by diffusion simultaneously or immediately thereafter, too.

• KSBB Journal
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• v.17 no.6
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• pp.537-542
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• 2002

To screening of antimicrobial activity, 95% ethanol and hot water extracts of roots, fruits, leaves, radix and stems of 50 species of traditional herbal medicines were examined. For their growth inhibitory effects on two food-born microorganisms, S. aureus and E. coli O157:H7, by the paper disc diffusion method and the minimum inhibitory concentration(MIC) test. Moutan radicis Cortex and Achyranthis Radix showed the highest inhibitory activities on both S. aureus and E. coli O157:H7. The Inhibition zones of Moutan radicis Cortex on S. aureus and E. coii O157:H7 were 22 mm and 24 mm respectively, and the corresponding inhibition zone of Achyranthis Radix were 23 mm and 22 mm. The MIC or Achyranthis Radix on S. aureus was 156.25 $\mu$g/mL, and the MIC or Achyranthis Radix and Moutan radicis Cortexas on E. coli O157:H7 were 625 $\mu$g/mL and 312.5 $\mu$g/mL, respectively. Their antimicrobial activities in ethanolic extracts were significantly higher than in hot water extracts. In the various solvent fractions prepared from ethanol extract, the ethyl acetate fraction of Achyranthis Radix and the CHCl$_3$ fraction of Moutan radicis Cortexas showed strongest activity.