• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.627-635
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• 2020

Objectives: Indoor air quality has become more important aspeople spend most of their times indoors. Since students spend most of their times at home or at school, they are more likely to be exposed to indoor air pollutants. Ventilation in school classrooms can affect health and learning performance. In this study, ventilation deficiency was evaluated in school classrooms using Monte Carlo simulation. Methods: This study used sensor-based monitoring for six months to measure carbon dioxide (CO2) concentrations in classrooms in elementary, middle, and high schools. The volume of the classroom and the number of students were investigated, and the students' body surface area was used to calculate the CO2 emission rate. The distribution of ventilation rates was estimated by measured CO2 concentration and a mass-balance model using Monte Carlo simulation. Results: In the elementary, middle, and high schools, the average CO2 concentrations exceeded 1000 ppm, indicating that the ventilation rates were insufficient. The ventilation rates were deficient from July to August and in December, but showed relatively high ventilation rates in October. Forty-three percent of elementary schools, 56% of middle schools, and 62% of high schools showed insufficient ventilation rates. Conclusions: The ventilation rates calculated in elementary, middle and high schools were found to be quite insufficient. Therefore, proper management is needed to overcome the lack of ventilation and improve air quality.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.371-382
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• 2020

There have been continuous attempts to quantify sensory attributes of cosmetic products by measuring relevant physical properties. The most representative method to evaluate stickiness is to measure axial force using texture analyzer. Stickiness is known to correlate with AUC which abbreviates area under curve in the obtained axial force curve as a function of time. Recently, Normandie University research group developed in vivo stickiness evaluation method considering the characteristics of skin along with established evaluation method[8]. Based on the study, we tried to optimize in vivo stickiness evaluation method especially for cosmetic creams. The experiment was carried out on 5 different facial creams products by changing the amount and the times of rolling of creams, and the shape and material of probes. Based on the results of the sensory evaluation, the most consistent conditions were established as the optimal evaluation method. As a result, applying 70 μL of cream and rubbing 10 times for 7 s inside the 3.4 cm circle were judged to be suitable. As for the probes, spherical metallic probe was more proper due to its reproducibility. We conducted the settled method on 10 subjects to check its validity. Although the absolute values of AUC differed depending on the individuals, the AUC values were all ranked the same. Finally, for the standardization of stickiness of AUC, polyvinylpyrrolidone (PVP) was set as a reference material and we measured AUC of its aqueous solution by changing concentration. Then, the degree of stickiness recognition for 5 different creams was surveyed to check the correlation between AUC and stickiness.

• Journal of Plant Biotechnology
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• v.49 no.2
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• pp.155-161
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• 2022

This study investigated the antioxidant and anti-inflammatory effects of seed ethanol extracts from Rubus coreanus Miquel (SERC). To investigate the antioxidant activity, total polyphenol and flavonoid content, ABTS and DPPH radical scavenging activity, and reducing power were measured. The total polyphenol and flavonoid contents in seed ethanol extracts of R. coreanus Miq. were 4.09 ㎍ gallic acid equivalents (GAE)/mg and 16.25 ㎍ quercetin equivalents (QE)/mg, respectively. DPPH and ABTS radical scavenging activity showed concentration-dependent scavenging activity, and the RC₅₀ values of SERC were 26.68 ㎍/mL and 39.30 ㎍/mL, respectively. Moreover, the ferric reducing antioxidant power (FRAP) assay was performed to assess the reducing power, and SERC showed 0.61 ± 0.01 mM FeSO₄ E/mg. To measure the anti-inflammatory effect, the cytotoxicity and nitric oxide (NO) production inhibitory efficacy in RAW 264.7 cells was confirmed. SERC showed a NO production inhibitory effect at 500 ㎍/mL without cytotoxicity. As a result of verifying the antioxidant and anti-inflammatory activity using SERC, its potential as an antioxidant and anti-inflammatory material was confirmed.

• Geomechanics and Engineering
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• v.25 no.3
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• pp.207-219
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• 2021

Several additives are used to enhance the geotechnical properties (e.g., shear wave velocity, shear modulus) of soils to provide sustainable, economical and eco-friendly solutions in geotechnical and geo-environmental engineering. In this study, piezoelectric ring actuators are used to measure the shear wave velocity of unreinforced, fiber, cemented, and fiber reinforced cemented Toyoura sand. One dimensional oedometer tests are performed on medium dense specimens of Toyoura sand-cement-fiber-silica flour mixtures with different percentages of silica flour (0-42%), fiber and cement (e.g., 0-3%) additives. The experimental results indicate that behavior of the mixtures is significantly affected by the concentration of silica flour, fiber and cement additives. Results show that with the addition of 1-3% of PVA fibers, the shear wave velocity increases by only 1-3%. However, the addition of 1-4% of cement increases the shear wave velocity by 8-35%. 10.5-21% increase of silica flour reduces the shear wave velocity by 2-5% but adding 28-42% silica flour significantly reduces the shear wave velocity by 12-31%. In addition, the combined effect of cement and fibers was also found and with only 2% cement and 1% fiber, the shear wave velocity increase was found to be approximately 24% and with only 3% cement and 3% fibers this increased to 35%. The results from this study for the normalized shear modulus and normalized mean effective stress agree well with previous findings on pure Toyoura sand, Toyoura silty sand, fiber reinforced, fiber reinforced cemented Toyoura sand. Any variations are likely due to the difference in stress history (i.e., isotropic versus anisotropic consolidation) and the measurement method. In addition, these small discrepancies could be attributed to several other factors. The potential factors include the difference in specimen sizes, test devices, methods of analysis for the measurement of arrival time, the use of an appropriate Ko to convert the vertical stresses into mean effective stress, and sample preparation techniques. Lastly, it was investigated that there is a robust inverse relationship between α factor and 𝞫₀ exponent. It was found that less compressible soils exhibit higher 𝜶 factors and lower 𝞫₀ exponents.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.339-344
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• 2022

It is about how much fine dust can be efficiently removed with respect to the electric dust collector used in factories and large facilities. The results of evaluating the fine dust removal efficiency are as follows. At 10,000 V, Efficiency method I showed 68.1 %, and Efficiency method II was 58.6 %, which was lower than that of Efficiency method I. At 5,000 V, Efficiency method I showed 57.6%, and Efficiency method II showed 51.6%, which was lower than Efficiency method I. At 2,500 V, Efficiency method I showed 50.3%, and Efficiency method II showed 24.4%, which was lower than Efficiency method I. In case of Efficiency method I, it is the efficiency calculated by using the dust concentration before and after passing through the filter. Efficiency method II calculated Efficiency method II to measure the efficiency a little more accurately in the environment where the air after the filter and the polluted air are mixed. Efficiency method II showed lower efficiency than Efficiency method I. As a result of the electrostatic precipitator test, the dust collecting performance was highest at 10,000 V, followed by 5,000 V and 2,500 V in that order.

• The Korea Journal of Herbology
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• v.28 no.5
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• pp.7-11
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• 2013

Objectives : Seungmagalgeun-tang (SMGGT) is traditional medicine widely used for inflammatory disease and flu. But SMGGT exhibits potent anti-inflammatory activity with an unknown mechanism. To elucidate the molecular mechanisms of SMGGT water extract on pharmacological and biochemical actions in inflammation, we examined the effect of SMGGT on pro-inflammatory mediators in Phorbol-12-myristate-13-acetate (PMA)+A23187-stimulated mast cells. Methods : In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR), and western blot analysis to measure the activation of MAPKs. Cells were treated with SMGGT 1 h prior to the addition of 50 nM of PMA and $1{\mu}M$ of A23187. Cell viability was measured by MTS assay. The investigation focused on whether SMGGT inhibited the expressions of interleukin-6 (IL-6), interleukin-8 (IL-8) and mitogen-activated protein kinases (MAPKs) in PMA+A23187-stimulated mast cells. Results : SMGGT has no cytotoxicity at examined concentration (100, 250, and $500{\mu}g/ml$). Also, gene expression of IL-6 and IL-8 in HMC-1 cells stimulated by PMA+A23187 was down regulated by SMGGT. Furthermore, SMGGT suppressed the PMA+A23187-induced phosphorylation of extracellular signal-regulated kinase (ERK) and c-jun N-terminal Kinase(JNK). But, SMGGT could not regulate phosphorylation of p38 MAPK. Conclusions : These results suggest that SMGGT has inhibitory effects on PMA+A23187-induced IL-6 and IL-8 production. These inhibitory effects occur through blockades on the phosphorylation of ERK and JNK.

• The Korea Journal of Herbology
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• v.34 no.1
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• pp.51-57
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• 2019

Objectives : Nypa fruticans Wurmb. (NF) have been used as a traditional medicine to treat inflammatory diseases in East-South Asia. However, it is largely undiscovered whether NF water extract could exhibit anti-inflammatory activities against tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced inflammatory responses on human keratinocytes, HaCaT cells. Therefore, this study was aimed to investigate the anti-inflammatory activity of NF water extract on TNF-${\alpha}$-induced inflammatory responses in HaCaT cells. Methods : To investigate the anti-inflammatory activites of NF water extract in HaCaT cells, the inflammatory model of HaCaT cells was established under a suitable concentration (10 ng/ml) of human TNF-${\alpha}$ (hTNF-${\alpha}$). HaCaT keratinocyte cells were pre-treated with NF water extract for 1 h, and then stimulated with hTNF-${\alpha}$. Then, the cells were harvested to measure the inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and prostaglandin $E_2$ ($PGE_2$), and pro-inflammatory cytokine including TNF-${\alpha}$ and interleukin (IL)-6. In addition, we examined the inhibitory mechanisms of NF, mitogen activated protein kinases (MAPKs) and inhibitory kappa B alpha ($I{\kappa}-B{\alpha}$) Results : The treatment of NF inhibited the hTNF-${\alpha}$-induced elevation of iNOS, COX-2, and $PGE_2$ in HaCaT cells. In addition, NF treatment inhibited the hTNF-${\alpha}$-induced elevation of TNF-${\alpha}$ and IL-6. Furthermore, NF treatment inhibited the activation of MAPKs but not degradation of $I{\kappa}-B{\alpha}$. Conclusions : Taken together, our result suggest that treatment of NF could inhibit the hTNF-${\alpha}$-induced inflammatory responses via deactivation of MAPKs in HaCaT cells. This study could suggest that NF could be a beneficial agent to prevent skin damage or inflammation.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.849-854
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• 2022

In this study, the anti-inflammatory effect of supercritical carbon dioxide selective extracts, which extract decursin and decursinol angelate, the vital active ingredients of Angelica gigas Nakai, in high yield, was measured compared to that of ethanol extracts. To measure the anti-inflammatory effect, the production of nitric oxide(NO), an inflammatory mediator, and interleukin(IL)-6 and IL-8, inflammatory cytokines, was measured. NO production was measured by Griess assay on Raw 264.7 cells induced inflammatory response by lipopolysaccharide(LPS), and IL-6 and IL-8 production was measured by enzyme-linked immunoadsorbent assay(ELISA) on human keratinocyte cell line(HaCaT) cells induced inflammatory response by tumor necrosis factor(TNF)-α. The amount of NO production was suppressed outstandingly by the supercritical carbon dioxide extracts compared to the ethanol extracts. The amount of IL-6 and IL-8 production was increased by the ethanol extracts, whereas statistically significantly inhibited by supercritical carbon dioxide extracts at the concentration of 6.25 ㎍/mL(P<0.01). Through these results, we confirmed that the supercritical carbon dioxide selective extracts of Angelica gigas Nakai could be used as an anti-inflammatory cosmeceutical material to alleviate atopic dermatitis.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.683-691
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• 2021

The purpose of this study is to measure the yield and to evaluate the physiological activity of Cannabis sativa seed(Hemp seed) extracts extracted using a density fluctuation supercritical carbon dioxide for each temperature condition-30℃(HSSE30), 45℃(HSSE45), 60℃(HSSE60), and to enable dissolution of the poorly water-soluble extracts by liposome formulation and to enhance the skin permeability. As a result of the yield measurement, HSSE60 showed the highest yield, and in the antioxidant activities, HSSE45 had the highest total polyphenol content, and showed the highest DPPH, ABTS+ radical scavenging activities at the highest concentration of the extracts. As a result of the antimicrobial susceptibility testing, a clear zone appeared only in the Propionibateium acnes strain. It was confirmed that particle size was reduced and the absolute value of the zeta potential increased in the case of the formulation in which the extracts were in liposomes than in the formulation in which the extracts were dissolved in deionized water, and the skin permeability was improved. Based on these experimental results, we confirmed the possibility of using the hemp seed supercritical carbon dioxide extracts, a poorly water-soluble extract, can be applied as a functional natural material for cosmetics.

• Journal of the Korean GEO-environmental Society
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• v.23 no.3
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• pp.23-29
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• 2022

In this study, we investigated the ozone nanobubble process in which nanobubble and ultrasonic cavitation were applied simultaneously to improve the dissolution and self-decomposition of ozone. To confirm the organic decomposition efficiency of the process, a 200 mm × 200 mm × 300 mm scale reactor was designed and phenol decomposition experiments were conducted. The use of nanobubble was 2.07 times higher than the conventional ozone aeration in the 60 minutes reaction and effectively improved the dissolution efficiency of ozone. Ultrasonic irradiation increased phenol degradation by 36% with nanobubbles, and dissolved ozone concentration was lowered due to the promotion of ozone self-decomposition. The higher the ultrasonic power was, the higher the phenol degradation efficiency. The decomposition efficiency of phenol was the highest at 132 kHz. The ozone nanobubble process showed better decomposition efficiency at high pH like conventional ozone processes but achieved 100% decomposition of phenol after 60 minutes reaction even at neutral conditions. The effect by pH was less than that of the conventional ozone process because of self-decomposition promotion. To confirm the change in bubble properties by ultrasonic irradiation, a Zetasizer was used to measure the bubbles' size and zeta potential analysis. Ultrasonic irradiation reduced the average size of the bubbles by 11% and strengthened the negative charge of the bubble surface, positively affecting the gas transfer of the ozone nanobubble and the efficiency of the radical production.