• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.260-266
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• 2021

This study aimed to identify the hepatoprotective effects of a fermented Chrysanthemum indicum L. water extract. The extraction yield, antioxidant activities (ABTS and DPPH), and content of luteolin and luteolin-7-glucoside were significantly higher in the fermented C. indicum L. water extract (FCI) than in the C. indicum L. water extract. Treatment with FCI (200 ㎍/mL) significantly reduced the activities of gamma(γ)-glutamyl transferase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in HepG2 cells treated with 3% ethanol. Furthermore, FCI did not affect the viability of the HepG2 cells. These results suggest that FCI can be useful for the development of an effective hepatoprotective agent.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.312-319
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• 2021

Photothermal therapy is a treatment that necrotizes selectively the abnormal cells, in particular cancer cells, which are more vulnerable to heat than normal cells, using the heat generated when irradiating light. In this study, we synthesized a reduced graphene oxide with carboxyl groups (CRGO)-gold nanorod (AuNR) nanocomposite for photothermal treatment. Graphene oxide (GO) was selectively reduced and exfoliated at high temperature to synthesize CRGO, and the length of AuNR was adjusted according to the amount of AgNO₃, to synthesize AuNR with a strong absorption peak at 880 nm, as an ideal photothermal agent. It was determined through FT-IR, thermogravimetric and fluorescence analyses that more carboxyl groups were conjugated with CRGO over RGO. In addition, CRGO exhibited excellent stability in aqueous solutions compared to RGO due to the presence of carboxylic acid. The CRGO-AuNR nanocomposites fabricated by electrostatic interaction have an average size of ~317 nm with a narrow size distribution. It was confirmed that under radiation with a near-infrared 880 nm laser which has an excellent tissue transmittance, the photothermal effect of CRGO-AuNR nanocomposites was greater than that of AuNR due to the synergistic effect of the two photothermal agents, CRGO and AuNR. Furthermore, the results of cancer cell toxicity by photothermal effect revealed that CRGO-AuNR nanocomposites showed superb cytotoxic properties. Therefore, the CRGO-AuNR nanocomposites are expected to be applied to the field of anticancer photothermal therapy based on their stable dispersibility and improved photothermal effect.

• Clean Technology
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• v.27 no.1
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• pp.24-32
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• 2021

Unburned carbon (UC) was successfully separated from fly ash by up to 85.8% in weight via froth flotation using soybean oil as a collector. An 18 wt% yield of microceramics (CM) could be achieved by employing a hydro cyclone separator located immediately after the flotation equipment. UC and CM were tested as alternatives to weight-adding material and polymer (especially polypropylene in this study) filler, respectively. Large particles of UC were broken down into smaller ones via ball milling to have an average particle diameter of 10.2 ㎛. When crushed UC was used as an alternative to clay as a rubber weight-adding material, a somewhat lower tensile strength and elongation rate than the allowed values were unfortunately obtained. In order to satisfy the standard limits, further treatment of UC is required to enhance surface energy for more intimate bonding with rubber. CM was observed in spherical forms with an average diameter of 5 ㎛. The surface of the CM particles was modified with phenol, polyol, stearic acid, and oleic acid so that the surface modified CM could be used as a polypropylene-filling agent. The flowability was good, but due to the lack of coupling forces with polypropylene, successful impact strength and flexural strength could not be obtained. However, when mixing the surface-modified CM with 1% silane by weight, a drastic increase in both the impact strength and flexural strength were obtained.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.467-474
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• 2020

Carbon nanotube has excellent mechanical strength and functionality, so it has been utilized in various applications. In recent years, utilization of carbon nanotube in construction material has started to get interests from researchers in the area of construction materials. However, there is limited amount of work with respect to the rheological properties of cement paste using carbon nanotube. In this work, solution made of multi-walled carbon nanotube with dispersing agent of polyvinyl pyrrolidone was used to prepare cement paste specimens, and rheological properties and 28 day compressive strengths of cement paste using multi-walled carbon nanotube were measured. According to the experimental results, as the amounnt of multi-walled carbon nanotube increased, plastic viscosity and yield stress of cement paste specimens also increased. It was also found that such effect was higher with lower w/c cement paste specimens. With respect to the compressive strength, it was maximized at carbon nanotube content of 0.1wt.% for w/c 0.30 cement paste, whereas the maximum strength of w/c 0.40 cement paste was observed with carbon nanotube content of 0.2wt%.

• Clean Technology
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• v.27 no.1
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• pp.55-60
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• 2021

Antibiotics are compounds broadly used to treat patients with infectious diseases and to enhance productivity in agriculture, fisheries, and livestock industries. However, due to the overuse of antibiotics and their low biodegradability, a substantial amount of antibiotics is leaking into the sewer, subsequently resulting in pollution and the emergence of antibiotic-resistant bacteria. This study explores biodegradable serum albumin's potential as an adsorbent to remove antibiotics from water. Serum albumin is a natural blood protein that transports various metabolites and hormones to all tissues' extravascular spaces. While serum albumin is highly water-soluble, it has intrinsic binding sites which readily accommodate ionic, hydrophilic, or hydrophobic molecules, rendering it a good building block for a nano-adsorbent. To induce coacervation, a desolvating agent, ethanol, was added dropwise into the aqueous albumin solution, resulting in dehydration and liquid-liquid phase separation of albumins into albumin nanoparticles within a size range of 150 ~ 170 nm. The addition of glutaraldehyde as a cross-linker improved the size stability and homogeneity of albumin nanoparticles. Adsorption of amoxicillin antibiotics on albumin nanoparticles was dependent upon glutaraldehyde concentration used in desolvation and pH during adsorption. The maximum adsorption capacity measured by spectrophotometry was found to be 12.4 micrograms of amoxicillin per milligram of albumin nanoparticle. These results demonstrate serum albumin's potential as a building block for fabricating a natural nano-adsorbent to remove antibiotics from water.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.134-140
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• 2022

Kelp belongs to the brown algae family and has been reported to exert anti-cancer effects on some cancer types, however studies have not been reported on the anti-cancer effects of kelp extracts on melanoma. In this study, the anti-cancer effects of kelp extract in B16-F0 cells were investigated, and the underlying molecular mechanisms were assessed. Kelp extract was found to inhibit the proliferation of B16-F0 cells, induce cytotoxicity, inhibit cell colony formation, and induce DNA fragmentation and apoptosis. The molecular mechanism was found to involve kelp extract increasing the expression of cytochrome-c and activated caspase-9 in the intrinsic apoptotic pathway. In addition, kelp extract upregulated the expression of Fas-associated protein with death domain and activated caspase-8 in the extrinsic apoptosis pathway. Activation of caspase-9 and caspase-8 by kelp extract induced activation of caspase-3 and cleaved poly adenosine diphosphate-ribose polymerase, consequently inducing apoptosis. These data suggest that kelp extract represents a potential therapeutic agent for melanoma.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.280-287
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• 2022

The loquat (Eriobotrya japonica) is a fruit tree belonging to the Rosaceae family. Loquat fruit extracts from three cultivars (Tanaka, Mogi, and Jinwang) were prepared using absolute methanol and homogenization and ultrasound sonication procedures. We measured the total phenolic and flavonoid content of the fruit extracts and their antioxidant capacities. In addition, we evaluated tyrosinase activity and anti-melanogenic effects in B16F1 melanoma cells. The fruit extract from cv. Tanaka had the highest total phenolic content and showed the highest antioxidant capacity in the ABTS assay. The loquat fruit extract from cv. Jinwang had the highest total flavonoid content and showed the highest antioxidant capacity in the DPPH assay. Loquat fruit extracts from the Tanaka and Jinwang cultivars effectively inhibited mushroom tyrosinase activity. The loquat fruit extracts reduced intracellular oxidative stress in B16F1 melanoma cells. Treating B16F1 melanoma cells with loquat fruit extract from cv. Tanaka at a concentration of 125 ㎍/mL effectively inhibited melanin synthesis. However, treating the B16F1 melanoma cells with loquat fruit extracts from the Jinwang and Mogi cultivars did not. These results suggest that loquat fruit extracts from the Tanaka cultivar may serve as potential sources of antioxidants and act as a skin-whitening agent.

• Journal of the Korean Wood Science and Technology
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• v.32 no.5
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• pp.29-38
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• 2004

In this study, we investigated the thermal properties of corn-starch filled polybutylene succinate-adipate (PBS-AD) bio-composites. Thermal analysis (TA) is used to describe the analytical method for measuring the chemical property and weight loss of composite materials as a function of temperature. The thermal stability of corn-starch was lower than that of pure PBS-AD. As corn-starch loading increased, the thermal stability and degradation temperature of the bio-composites decreased and the ash content increased. It can be seen that the degree of compatibility and interfacial adhesion of the bio-composites decreased because of the increasing mixing ratio of the corn-starch. As the content of corn-starch increased, there was no significant change in the glass transition temperature (T_g) and the melting temperature (T_m) for the bio-composites. The storage modulus (E') and loss modulus (E") of the corn-starch flour filled PBS-AD bio-composites were higher than those of PBS-AD, because of the incorporation of corn-starch increased the stiffness of the bio-composites. At higher temperatures, the decreased storage modulus (E') of bio-composites was due to the increased polymer chain mobility of the matrix polymer. From these results, we can expect that corn-starch has potential as a reinforcing filler for bio-composites. Furthermore, we recommend using a coupling agent to improve the interfacial adhesion between corn-starch and biodegradable polymer.

• Trans-
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• v.12
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• pp.1-19
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• 2022

This study predicts and raises the changes that AI will bring to dance art when machine-based choreography began, and finds questions we can ask as human artists. Research suggests that one of the crises of dance in the era of machine creative arts is that artificial intelligence does not stay in the tool of human choreography but becomes the subject of choreography. It is based on the political discourse of choreography that artificial intelligence has the power to control and restrict human dancers. This comes from a sense of crisis that the AI takes over the area of choreography and the human choreographer remains an incompetent coordinator, and as a result, the dancer's dancing body can be reduced to a mechanical body controlled by AI. In order for these concerns not to become a reality, this study proposes three measures. First, choreographer and dancer should develop digital literacy to live in the age of AI art. Secondly, choreographer should acquire the ability to accurately distinguish the roles of human choreographer, dancer, and AI in creative work. Thirdly, various levels of discourse on AI dance should be formed by actively conducting mutual media research of dance and technology. Through these efforts, the human dancer will exist as a subject of art, not a passive agent in the new dance ecosystem brought by the innovation of artificial intelligence technology and will be able to face an era coexistence with artificial intelligence creativily and productively.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.71-76
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• 2012

Objectives : The purpose of this study was to evaluate the neuroprotective effect of Pueraria lobata extract on focal cerebral ischemia in mice. Methods : Focal cerebral ischemia was induced by occlusion of the right middle cerebral artery using the intraluminal filament model. ICR male mice underwent 90 minutes of middle cerebral artery occlusion (MCAo) followed by 24 hours of reperfusion. Mice were administered Pueraria lobata extract orally at the dose of 300mg/kg just prior to reperfusion. Rotarod test and balance beam test were practiced to assess sensory-motor function 23 hours after MCAo. In rotarod test, the latency to fall on the accelerating rotarod was recorded for 5 min. In balance beam test, the score was graded according to number of slips and latency to cross. The infarct volume was measured 24 hours after MCAo using 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining. Results : Pueraria lobata extract treated group showed significant reduction in infarct volume by 27.3% compared to control group (p<0.05). In rotatod test, it also showed significant extension of latency time compared to control group ($67.82{\pm}15.08$ vs. $5.62{\pm}1.06$, p<0.001). In contrast to performance in rotarod test, that in balance beam test did not improve with Pueraria lobata extract treatment. Conclusions : We conclude that Pueraria lobata extract has a significant neuroprotective effect and reduces damage of sensory-motor function in MCAo model. These findings suggest that Pueraria lobata could be a potent neuroprotective agent.