• Composites Research
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• v.32 no.3
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• pp.134-140
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• 2019

Graphene nanoplatelets (GNP), one of the graphene derivatives is famous as the most proper candidate for industrial applications. However, current performance of GNPs as reinforcing filler in composites is limited by their agglomeration and physicochemical heterogeneity. Herein, an approach to produce non-covalently functionalized GNPs (F-GNPs) is reported which possesses potential to be extended as the industrial level of mass production. The one-step functionalization process uses melamine, a low-cost chemical, to prevent agglomeration and dispersion in polar solvents. Furthermore, a purification strategy called salting-out process based on differences in the dispersibility of the individual F-GNP flakes is reported to separate F-GNPs. The functionalization and separation process developed in this paper provides a strategy to use GNPs at the industrial level in composite applications.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.471-479
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• 2020

The aim of this study was to investigate the anti-oxidant and anti-inflammatory activities of the Rhododendron weyrichii flower extract fermented using Shindari, a traditional Jeju barley Nuruk-based fermentation. In this study, we examined the antioxidant potential of R. weyrichii flower extracts (RF) and R. weyrichii flower extracts fermented with Nuruk or Shindari (RFFN or RFFS, respectively) using various in vitro antioxidant assays including DPPH and ABTS radical scavenging assays, total phenol content and FRAP assays. We also evaluated the anti-inflammatory activity of the RF and RFFS on murine RAW 264.7 cells. The anti-inflammatory activity was evaluated by treating the RAW 264.7 cells with various concentrations (6.25, 12.5, 25, and 50 ㎍/ml) of RF or RFFS. As a result, we observed that the ABTS radical scavenging activity and total phenol content of RFFS was higher than that of RF and RFFN. Additionally, lipopolysaccharide-induced nitric oxide (NO) production was significantly lower in RFFS-treated cells when compared to the LPS-treated control. In addition, RFFS-treated cells exhibited decreased expression of inducible NO synthase (iNOS) proteins and high-performance liquid chromatography (HPLC) fingerprinting showed that both the quercetin and quercetin glucoside (quercitrin and isoquercitrin) levels were affected by the fermentation process. In conclusion, our data suggests that traditional fermentation could be an important strategy in improving the biological properties of raw materials including their antioxidant and anti-inflammatory activities. Finally, RFFS may be a candidate for developing topical antioxidant and anti-inflammatory agents.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.467-471
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• 2021

A ladder-like polysilsesquioxane (LPMA64) functionalized with a crosslinkable group was synthesized and used for the preparation of organic-inorganic hybrid gel polymer electrolytes through a thermal crosslinking process of the liquid electrolytes. A small weight percent of LPMA64 polymer crosslinker (5 wt%) was able to form a well-developed network structure, resulting in good dimensional stability with high ionic conductivity. The lithium-sulfur batteries fabricated with organic-inorganic hybrid gel polymer electrolytes exhibited stable C-rate and cycling performance with excellent Coulombic efficiency due to the alleviated lithium polysulfide shuttling effect during prolonged cycling. The result demonstrates that the organic-inorganic hybrid gel polymer electrolytes could be a promising candidate electrolyte for application in lithium-sulfur batteries.

• Biomaterials Research
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• v.22 no.4
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• pp.290-302
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• 2018

Background: The main purpose of drug delivery systems is to deliver the drugs at the appropriate concentration to the precise target site. Recently, the application of a thin film in the field of drug delivery has gained increasing interest because of its ability to safely load drugs and to release the drug in a controlled manner, which improves drug efficacy. Drug loading by the thin film can be done in various ways, depending on type of the drug, the area of exposure, and the purpose of drug delivery. Main text: This review summarizes the various methods used for preparing thin films with drugs via Layer-by-layer (LbL) assembly. Furthermore, additional functionalities of thin films using surface modification in drug delivery are briefly discussed. There are three types of methods for preparing a drug-carrying multilayered film using LbL assembly. First methods include approaches for direct loading of the drug into the pre-fabricated multilayer film. Second methods are preparing thin films using drugs as building blocks. Thirdly, the drugs are incorporated in the cargo so that the cargo itself can be used as the materials of the film. Conclusion: The appropriate designs of the drug-loaded film were produced in consideration of the release amounts and site of the desired drug. Furthermore, additional surface modification using the LbL technique enabled the preparation of effective drug delivery carriers with improved targeting effect. Therefore, the multilayer thin films fabricated by the LbL technique are a promising candidate for an ideal drug delivery system and the development possibilities of this technology are infinite.

• Plant Breeding and Biotechnology
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• v.5 no.2
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• pp.134-142
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• 2017

Resource plants are important and have strong potential for a variety of utilities as crops or pharmaceutical materials. However, most resource plants remain wild and thus their utility for breeding and biotechnology is limited. Molecular markers are useful to initiate genetic study and molecular breeding for these understudied resource plants. We collected various wild collections of Peucedanum japonicum which is indigenous resource plants utilized as oriental medicine and leafy vegetables in Korea. In this study, we produced two independent whole genome sequences (WGSs) from two collections and identified large scale polymorphic simple sequence repeat (pSSR) based on our pipeline to develop SSR markers based on comparison of two WGSs. We identified a total of 452 candidate pSSR contigs. To confirm the accuracy and utility of pSSR, we designed ten SSR primer pairs and successfully applied those to seven collections of P. japonicum. The WGS and pSSR candidates identified in this study will be useful resource for genetic research and breeding purpose for the valuable resource plant, P. japonicum.

• Journal of the Korean Wood Science and Technology
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• v.50 no.5
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• pp.338-352
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• 2022

Herein, water and ethanol extracts were obtained from the leaves, branches, kernels, and pericarp of Quercus gilva and subsequently analyzed for antioxidant activity and circadian rhythm regulation effects. Candidate components that may affect circadian rhythm and antioxidant activity were investigated to discover potential functional materials. Antioxidant activity was analyzed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity assays, showing that the hot water extract exhibited higher activity than that of the ethanol extract. In particular, the branch extract showed high antioxidant activity. By measuring total contents of polyphenols, flavonoids, and tannins, the hot water branch extract showed the highest concentrations, highlighting their significant contribution to the antioxidant activity. Examination of the circadian rhythm regulation of each extract showed that the ethanol extract exhibited greater impacts on the circadian rhythm amplitude compared to the water extract. The branch ethanol extract induced circadian rhythm amplitude changes via clock gene Bmal1 expression regulation. Determination of 12 phenolic compound concentrations showed that the branch ethanol extract contained many phenolic compounds, including catechin. This suggests that these com- pounds affected circadian rhythm regulation. In conclusion, the hot water branch extract has potential as an natural antioxidant material, while the corresponding ethanol extract has potential as a functional material for regulating circadian rhythm.

• Fisheries and Aquatic Sciences
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• v.25 no.8
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• pp.450-461
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• 2022

A randomized, double-blind, and placebo-controlled clinical study was used to determine the cognitive functions related to working memory (WM) and antioxidant properties of fermented Laminaria japonica (FLJ) on healthy volunteers. Eighty participants were divided into a placebo group (n = 40) and FLJ group (n = 40) that received FLJ (1.5 g/day) for 6 weeks. Memory-related blood indices (brain-derived neurotrophic factor, BDNF; angiotensin-converting enzyme; human growth hormone, HGH; insulin-like growth factor-1, IGF-1) and antioxidant function-related indices (catalase, CAT; malondialdehyde, MDA; 8-oxo-2'-deoxyguanosine, 8-oxo-dG; thiobarbituric acid reactive substances, TBARS) were determined before and after the trial. In addition, standardized cognitive tests were conducted using the Cambridge Neuropsychological Test Automated Batteries. Furthermore, the Korean Wechsler Adult Intelligence Scale (K-WAIS)-IV, and the Korean version of the Montreal Cognitive Assessment (MoCA-K) were used to assess the pre and post intake changes on WM-related properties. According to the results, FLJ significantly increased the level of CAT, BDNF, HGH, and IGF-1. FLJ reduced the level of TBARS, MDA, and 8-oxo-dG in serum. Furthermore, FLJ improved physical activities related to cognitive functions such as K-WAIS-IV, MoCA-K, Paired Associates Learning, and Spatial Working Memory compared to the placebo group. Our results suggest that FLJ is a potential candidate to develop functional materials reflecting its capability to induce antioxidant mechanisms together with WM-related indices.

• Journal of Electrochemical Science and Technology
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• v.12 no.2
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• pp.237-245
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• 2021

Atomic layer deposition (ALD) enhances the stability of cathode materials via surface modification. Previous studies have demonstrated that an Ni-rich cathode, such as LiNi_0.8Co_0.1Mn_0.1O₂, is a promising candidate owing to its high capacity, but is limited by poor cycle stability. In this study, to enhance the stability of the Ni-rich cathode, synthesized LiNi_0.8Co_0.1Mn_0.1O₂ was coated with Al₂O₃ using ALD. Thus, the surface-modified cathode exhibited enhanced stability by protecting the interface from Ni-O formation during the cycling process. The coated LiNi_0.8Co_0.1Mn_0.1O₂ exhibited a capacity of 176 mAh g^-1 at 1 C and retained up to 72% of the initial capacity after 100 cycles within a range of 2.8-4.3 V (vs Li/Li⁺. In contrast, pristine LiNi_0.8Co_0.1Mn_0.1O₂ presented only 58% of capacity retention after 100 cycles with an initial capacity of 173 mAh g^-1. Improved cyclability may be a result of the ALD coating, which physically protects the electrode by modifying the interface, and prevents degradation by resisting side reactions that result in capacity decay. The electrochemical impedance spectra and structural and morphological analysis performed using electron microscopy and X-ray techniques establish the surface enhancement resulting from the aforementioned strategy.

• The Korea Journal of Herbology
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• v.32 no.2
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• pp.17-24
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• 2017

Objective : This study was designed to evaluate candidate materials as anti-inflammation agent from extracts of various Korean Compositae herbs in Hwaak mountain. Among Korea medicinal herbs, Ainsliaea acerifolia (AA) belongs to the Compositae family, has been used for the treatment of rheumatic arthritis. However, AA has not been previously reported to have an anti-inflammatory effect. Therefore, we investigated the anti-inflammatory effects of AA and its underlying molecular mechanisms in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Methods : Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in RAW 264.7 macrophages. Nitric oxide (NO) was measured with Griess reagent and pro-inflammatory cytokines were detected by enzyme immunoassay (EIA) kits in LPS-stimulated RAW 264.7 macrophages. Protein expressions of inducible nitric oxide synthase, and cyclooxygenase-2 (COX-2) and p65 subunit of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) were determined by Western blot analysis. Results : Among 8 extracts of Korean Compositae herbs tested, AA showed the inhibition of NO production without cytotoxicity. Consistent with the observation, AA reduced the expression levels of iNOS and COX-2 proteins in LPS-simulated RAW 264.7 macrophages in dose-dependent manner. In addition, AA inhibited the productions of $TNF-{\alpha}$ and IL-6 in LPS-simulated RAW 264.7 macrophages. However, AA did not inhibit activation of p65 $NF-{\kappa}B$ in LPS-simulated RAW 264.7 macrophages. Conclusion : These results suggest that down-regulation of iNOS, COX-2 protein expression and $TNF-{\alpha}$ and IL-6 production by AA are responsible for its anti-inflammatory effects.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.91-97
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• 2019

Objective : To establish a reliable tool between for the distinction of original plants of Sanguisorbae Radix, we analyzed the complete chloroplast genome sequence of Sanguisorbae Radix and identified single nucleotide polymorphisms (SNPs). Materials and methods : The chloroplast genome sequence of Sanguisorba officinalis, Sanguisorba tenuifolia f. alba (Trautv. & Mey.) Kitam and Sanguisorba tenuifolia Fisch. ex Link obtained using next-generation sequencing technology were described and compared with those of other species to develop specific markers. Candidate genetic markers were identified to distinguish species from the chloroplast sequences of each species using Modified Phred Phrap Consed and CLC Genomics Workbench programs. Results : The structure of the chloroplast genome of each sample that had been assembled and verified was circular, and the length was about 155 kbp. Through comparative analysis of the chloroplast sequences, we found 220 nucleotides, 158 SNPs, and 62 Indel (insertion and/or deletion), to distinguish Sanguisorba officinalis, Sanguisorba tenuifolia f. alba (Trautv. & Mey.) Kitam and Sanguisorba tenuifolia Fisch. ex Link. Finally, 15 specific SNP genetic markers were selected for the verification at positions. Avaliable primers for the dried herb, which is used as medicine, were used to develop the PCR amplification product of Sanguisorbae Radix to assess the applicability of PCR analysis. Conclusion : In this study, we found that Fendel-qPCR analysis based on the chloroplast DNA sequences can be an efficient tool for discrimination of Sanguisorba officinalis, Sanguisorba tenuifolia f. alba (Trautv. & Mey.) Kitam and Sanguisorba tenuifolia Fisch. ex Link.