• Journal of Ginseng Research
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• v.43 no.2
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• pp.272-281
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• 2019

Background: Diabetic sensorineural damage is a complication of the sensory neural system, resulting from long-term hyperglycemia. Red ginseng (RG) has shown efficacy for treatment of various diseases, including diabetes mellitus; however, there is little research about its benefit for treating sensorineural damage. Therefore, we aim to evaluate RG efficacy in alloxan-induced diabetic neuromast (AIDN) zebrafish. Methods: In this study, we developed and validated an AIDN zebrafish model. To assess RG effectiveness, we observed morphological changes in live neuromast zebrafish. Also, zebrafish has been observed to have an ultrastructure of hair-cell cilia under scanning electron microscopy. Thus, we recorded these physiological traits to assess hair cell function. Finally, we confirmed that RG promoted neuromast recovery via nerve growth factor signaling pathway markers. Results: First, we established an AIDN zebrafish model. Using this model, we showed via live neuromast imaging that RG fostered recovery of sensorineural damage. Damaged hair cell cilia were recovered in AIDN zebrafish. Furthermore, RG rescued damaged hair cell function through cell membrane ion balance. Conclusion: Our data suggest that RG potentially facilitates recovery in AIDN zebrafish, and its mechanism seems to be promotion of the nerve growth factor pathway through increased expression of topomyosin receptor kinase A, transient receptor potential channel vanilloid subfamily type 1, and mitogen-activated protein kinase phosphorylation.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.672-678
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• 2011

In this work, carbon fibers were electrolessly Ni-plated in order to investigate the effect of metal plating on the electromagnetic shielding effectiveness (EMI-SE) of Ni-coated carbon fibers-reinforced epoxy matrix composites. The surfaces of carbon fibers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Electric resistance of the composites was tested using a 4-point-probe electric resistivity tester. The EMI-SE of the composites was evaluated by means of the reflection and adsorption methods. From the results, it was found that the EMI-SE of the composites enhanced with increasing Ni plating time and content. In high frequency region, the EMI-SE didn't show further increasing with high Ni content (Ni-CF 10 min) compared to the Ni-CF 5 min sample. In conclusion, Ni content on the carbon fibers can be a key factor to determine the EMI-SE of the composites, but there can be an optimized metal content at a specific electromagnetic frequency region in this system.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.119-125
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• 2020

Transition metal dichalcogenides (TMDCs), two-dimensional atomic layered materials with direct bandgap in the range of 1.1-2.1 eV, have attracted a lot of research interest due to their high response to light and capability to build new types of artificial heterostructures. However, the large-area synthesis of high-quality and uniform TMDC films with vertical-stacked heterostructure still remains challenge. In this study, we have developed a metal-organic chemical vapor deposition (MOCVD) system for TMDCs and conducted a systematic study on the growth of single-layer TMDCs and their heterostructures. In particular, using a bubbler-type organometallic compound sources, the concentration and flow rate of each source can be precisely controlled to obtain uniformly single-layered MoS2 and WS2 films over the centimeter scale. In addition, the MoS2/WS2 vertical heterostructure was achieved by growing WS2 film directly on the MoS2 film, as confirmed by electron microscopy, UV-visible spectrophotometer, Raman spectroscopy, and photoluminescence spectroscopy.

• Journal of the Korean Wood Science and Technology
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• v.49 no.4
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• pp.299-314
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• 2021

In this study, we investigated the effect of temperature on specific surface area and electrochemical properties when lignin-based porous carbon (LBPC) with potassium hydroxide (KOH) is activated. After preparing LBPCs using lignin-polyacrylonitrile (PAN) copolymer, which was synthesized by graft polymerizing lignin and acrylonitrile as a precursor, activated LBPCs (KA-LBPC-6, 7, 8, 9) were manufactured by activating LBPC with KOH at 600℃, 700℃, 800℃ and 900℃. To identify the surface characteristics of KA-LBPC, observations were made with a scanning electron microscopy (SEM), and the pore characteristics were identified via specific surface area analysis. The electrochemical properties were analyzed using a three-electrode system. The experiment has shown that micropores formed by activation can be observed in SEM images. KA-LBPC-7 had the best pore characteristics among KA-LBPCs, with a specific surface area of 2480.1 m²/g, a micropore volume of 0.64 cm³/g, and a mesopore volume of 0.76 cm³/g. KA-LBPC-7 showed the best electrochemical properties with a specific capacitance of 151.3 F/g at the scan rate of 2 mV/s.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.179-186
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• 2021

In this study, we attempted to comparatively analyze the structural characteristics of soot generated from marine engines to review the possibility of recycling crankcase soot by classifying it as exhaust soot and crankcase soot. The annealing procedure was performed in an argon gas atmosphere at 2,000℃ and 2,700℃, and Raman spectroscopy and High-Resolution Transmission Electron Microscopy(HRTEM) were used to analyze the structural properties of the samples. Furthermore, digital image processing techniques were utilized to quantitatively analyze the acquired HRTEM images. The Raman analysis demonstrated a relatively high G/D ratio in the exhaust soot and annealing conditions at 2,700℃. In the HRTEM images, both soot were able to identify similar forms of graphite nanostructures, but there were limitations in that they could not quantitatively derive differences in the degree of graphite depending on the type of soot and annealing temperature. Thus, digital image processing quantitatively analyzed the length and tortuosity of the fringe of the HRTEM image, which is consistent with the Raman analysis. This meant that the exhaust soot had a more graphite structure than the crankcase soot, and that annealing at a higher temperature improved the graphite structure. This study confirmed that both the crankcase soot and exhaust soot can be recycled as a graphite materials.

• Journal of Powder Materials
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• v.28 no.2
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• pp.143-149
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• 2021

In this study, (GaN)_1-x(ZnO)_x solid solution nanoparticles with a high zinc content are prepared by ultrasonic spray pyrolysis and subsequent nitridation. The structure and morphology of the samples are investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The characterization results show a phase transition from the Zn and Ga-based oxides (ZnO or ZnGa₂O₄) to a (GaN)_1-x(ZnO)_x solid solution under an NH3 atmosphere. The effect of the precursor solution concentration and nitridation temperature on the final products are systematically investigated to obtain (GaN)_1-x(ZnO)_x nanoparticles with a high Zn concentration. It is confirmed that the powder synthesized from the solution in which the ratio of Zn and Ga was set to 0.8:0.2, as the initial precursor composition was composed of about 0.8-mole fraction of Zn, similar to the initially set one, through nitriding treatment at 700℃. Besides, the synthesized nanoparticles exhibited the typical XRD pattern of (GaN)_1-x(ZnO)_x, and a strong absorption of visible light with a bandgap energy of approximately 2.78 eV, confirming their potential use as a hydrogen production photocatalyst.

• BMB Reports
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• v.55 no.6
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• pp.275-280
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• 2022

The treatment of atopic dermatitis (AD) is challenging due to its complex etiology. From epidermal disruption to chronic inflammation, various cells and inflammatory pathways contribute to the progression of AD. As with immunosuppressants, general inhibition of inflammatory pathways can be effective, but this approach is not suitable for long-term treatment due to its side effects. This study aimed to identify a plant extract (PE) with anti-inflammatory effects on multiple cell types involved in AD development and provide relevant mechanistic evidence. Degranulation was measured in RBL-2H3 cells to screen 30 PEs native to South Korea. To investigate the anti-inflammatory effects of Parasenecio auriculatus var. matsumurana Nakai extract (PAE) in AD, production of cytokines and nitric oxide, activation status of FcεRI and TLR4 signaling, cell-cell junction, and cell viability were evaluated using qRT-PCR, western blotting, confocal microscopy, Griess system, and an MTT assay in RBL-2H3, HEK293, RAW264.7, and HaCaT cells. For in vivo experiments, a DNCBinduced AD mouse model was constructed, and hematoxylin and eosin, periodic acid-Schiff, toluidine blue, and F4/80-staining were performed. The chemical constituents of PAE were analyzed by HPLC-MS. By measuring the anti-degranulation effects of 30 PEs in RBL-2H3 cells, we found that Paeonia lactiflora Pall., PA, and Rehmannia glutinosa (Gaertn.) Libosch. ex Steud. show an inhibitory activity of more than 50%. Of these, PAE most dramatically and consistently suppressed cytokine expression, including IL-4, IL-9, IL-13, and TNF-α. PAE potently inhibited FcεRI signaling, which mechanistically supports its basophil-stabilizing effects, and PAE downregulated cytokines and NO production in macrophages via perturbation of toll-like receptor signaling. Moreover, PAE suppressed cytokine production in keratinocytes and upregulated the expression of tight junction molecules ZO-1 and occludin. In a DNCB-induced AD mouse model, the topical application of PAE significantly improved atopic index scores, immune cell infiltration, cytokine expression, abnormal activation of signaling molecules in FcεRI and TLR signaling, and damaged skin structure compared with dexamethasone. The anti-inflammatory effect of PAE was mainly due to integerrimine. Our findings suggest that PAE could potently inhibit multi-inflammatory cells involved in AD development, synergistically block the propagation of inflammatory responses, and thus alleviate AD symptoms.

• CELLMED
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• v.11 no.4
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• pp.21.1-21.9
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• 2021

Background: Unani System of Medicine (USM) has its origin to Greece. To ensure and develop the quality, authenticity of Unani drugs, standardization on modern analytical parameter is essential requirement for drugs. Objectives: The aimed of the present study was to develop a standard profile of "Qurṣ-e-Mafasil" by systematic study through authenticated ingredients, pharmacognostic identification followed by physicochemical, TLC, HPTLC fingerprinting analysis as per standard protocol. Material and Methods: In this study three batches of "Qurṣ-e-Mafasil" QM were prepared by standard method as per UPI had been followed by organoleptic properties of formulation such as appearance, color, odor, taste. Powder Microscopy and physicochemical studies were carried out such as Uniformity of weight, Friability, Disintegration time, hardness, LOD, ash vales and extractive values in like aqueous, alcohol & hexane. Further qualitative tests such as Thin-Layer Chromatography (TLC), and High-Performance Thin Layer Chromatography (HPTLC) studies were also carried out to develop fingerprint pattern of the alcoholic solvent extract of QM. Phytochemical screening was carried out in different solvent extracts such as alcoholic, aqueous and chloroform extracts to detect the presence phytoconstituents in the formulation QM. Heavy metals, Microbial Load Contamination and pesticidal residues were also determined. Results: Qurṣ-e-Mafasil showed tablet-like appearance, light brown colour, mild pungent odour and acrid taste. Uniformity of weight (mg), friability (rpm), and hardness (kg/cm) and disintegration time was ranged between (500 to 503), (0.0340 to 0.038), (8.40 to 8.67) and (4-5 minutes) respectively for the three batches. Loss in weight on drying at 105℃ was ranged between (8.3425 to 8.7346). Extracted values were calculated in distilled water ranged between (30.9091 to 31.4358), hexane (1.1419 to 1.4281), and alcohol (3.3352 to 3.3962). The ash values recorded were ranged between (3.7336 to 3.8378), and acid insoluble ash (0.5859 to 0.6112).

• Membrane Journal
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• v.32 no.6
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• pp.486-495
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• 2022

This study presents the improved recovery efficiency of rare metal ions through the modified separation membrane wettability and hydrogen ion permeation in the anion exchange membrane (AEM) under the recovery process of combined electrodialysis and solvent extraction. Specifically, the wettability of the separator was enhanced by hydrophilic modification on one separator surface through polydopamine (PDA) and lipophilic modification on the other surface through SiO₂ or graphene oxide (GO). In addition, the modified surface of AEM with polyethyleneimine (PEI), PDA, poly(vinylidene fluoride) (PVDF), etc. reduces the water uptake and modify the pore structure for proton ions generation. The suppressed transport resulted in the reduced hydrogen ion permeation. In the characterization, the surface morphology, chemical properties and composition of membrane or AEM were analyzed with Scanning Electron Microscopy (SEM) and Fourier Transform-Infrared Spectroscopy (FT-IR). Based on the analyses, improved extraction and stripping and hydrogen ion transport inhibition were demonstrated for the copper ion recovery system.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.160-165
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• 2023

This study describes the light microscopical cell types and histochemical characteristics as a preliminary study for the research on integument of the walleye pollock Gadus chalcogrammus in accordance with the physiological and environmental changes. The lateral line of the integument surface showed a curve in the anterior part and was straight from the middle to the posterior part. Integument is composed of outer epidermis and inner dermis. The epidermis is a stratified layer composed of epithelial cells, mucous cells, and club cells. Epithelial cells are classified into squamous superficial cell, cuboidal intermediated cell and columnar basal cell. The thickness of epidermis was 122.9 ㎛, and the ratio of epidermis thickness to body length was 0.03%. The mucous cell and club cell of unicellular gland were mainly distributed in the apical and middle layer of epidermis. The mucous cell contained mucosal materials of acidic glycoprotein. The proportion of mucous cells and club cells were 21.3 (± 7.0)% and 4.0 (± 1.0)% of epidermal area, respectively. The dermis was dense connective tissue layer and composed of mainly collagen fibers. It also contained fibrocytes, blood vessels, melanophores and scales.