• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.503-508
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• 2019

To evaluate the protective effect of Ecklonia cava on ultra-fine dust ($PM_{2.5}$)-induced cytotoxicity, we investigated the in vitro antioxidant activity and cell viability after exposure to $PM_{2.5}$. E. cava was extracted using water and 80% ethanol, and antioxidant activity was determined using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS)/2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation inhibition assays. The 80% ethanol extract showed relatively higher antioxidant activity than the water extract. The cell protective effects were determined by measuring the intracellular reactive oxygen species (ROS) content and viability of nasal epithelial (RPMI-2650), lung epithelial (A549), and brain neuroblastoma (MC-IXC) cells. Results showed that the 80% ethanol extract inhibited ROS production more than the water extract. In contrast, both extracts showed similar effects on cell viability in the $PM_{2.5}$-induced cell death assay. Thus, Ecklonia cava may act as an effective resource for preventing $PM_{2.5}$-induced cytotoxicity in nasal, lung, and brain cells.

• Journal of The Korean Society of Clinical Toxicology
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• v.17 no.2
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• pp.102-107
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• 2019

Purpose: Acute carbon monoxide (CO) poisoning is one of the most common types of poisoning and a major health problem worldwide. Treatment options are limited to normobaric oxygen therapy, administered using a non-rebreather face mask or hyperbaric oxygen. Compared to conventional oxygen therapy, high-flow nasal cannula oxygen (HFNC) creates a positive pressure effect through high-flow rates. The purpose of this human pilot study is to determine the effects of HFNC on the rate of CO clearance from the blood, in patients with mild to moderate CO poisoning. Methods: CO-poisoned patients were administered 100% oxygen from HFNC (flow of 60 L/min). The fraction of COHb (fCOHb) was measured at 30-min intervals until it decreased to under 10%, and the half-life time of fCOHb (fCOHb t_1/2) was subsequently determined. Results: At the time of ED arrival, a total of 10 patients had fCOHb levels ≥10%, with 4 patients ranging between 10% and 50%. The mean rate of fCOHb elimination patterns exhibits logarithmic growth curves that initially increase quickly with time (HFNC equation, Y=0.3388*X+11.67). The mean fCOHbt_1/2 in the HFNC group was determined to be 48.5±12.4 minutes. Conclusion: In patients with mild to moderate CO poisoning, oxygen delivered via high flow nasal cannula is a safe and comfortable method to treat acute CO toxicity, and is effective in reducing the COHb half-life. Our results indicate HFNC to be a promising alternative method of delivering oxygen for CO toxicity. Validating the effectiveness of this method will require larger studies with clinical outcomes.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.355-363
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• 2009

Double cropping system of oilseed crops introduced rape and castor bean was studied in the newly reclaimed tidal land of Korea. Surface soil EC to reach at 50% of growth reduction to the tallest height of crops was estimated $4dS\;m^{-1}$ for castor bean and $6dS\;m^{-1}$ for rape by logarithmic function. The castor bean cultivated during rainy summer much more suffered serious growth and yield reduction by flooding damage in the Hwaong and Yeonsangang reclaimed lands having low soil conductivity and finer textured soil than in the Iweon reclaimed land having higher soil conductivity and coarse sandy textured soil. Rape cultivated during dry winter-spring much more suffered serious growth and yield reduction by high soil salinity come from re-salting process. 50% yield reduction was estimated at $2.0\;2.5dS\;m^{-1}$ of surface soil EC by logarithmic function. Consequentially, it was concluded that oilseed production for energy by double cropping system of rape and castor bean might be possible under good controling soil salinity below $4dS\;m^{-1}$ for castor and $3dS\;m^{-1}$ for rape in the newly reclaimed land of Korea.

• Korean Journal of Ichthyology
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• v.31 no.3
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• pp.123-130
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• 2019

The olfactory organ of the Korean endemic fish, Rhodeus uyekii, a mussel-spawning species, was researched anatomically, histologically and histochemically, for looking into a relation to the physical and chemical condition of its habitat and ecological habit, using stereo microscopy, light microscopy and scanning electron microscopy. The external structure of the olfactory organ consists of the semicircular-shaped anterior nostril with arched shape at its forward position, posterior nostrils and the nasal flap. Within the olfactory chamber, it has the rosette structure with 14 to 15 lamellae which is largely divided into the sensory and non-sensory regions. The sensory region has the olfactory receptor neurons, the supporting cells, the basal cells, the lymphatic cells, and the plasma cells, while the non-sensory region has the stratified epithelial cells, the mucous cells with sulfomucin and 1 type of unidentified cell. In particular, the arched feature in the anterior nostril and the mucous cell of sulfomucin were unique.

• Atmosphere
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• v.29 no.1
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• pp.105-112
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• 2019

Measurements of vertical air motion and microphysics are essential for improving our understanding of convective clouds. In this paper, the author reviews the current research on the retrieval of vertical air motions using the cloud radar. At radar wavelengths of 3 mm (W-band radar; 94-GHz radar; cloud radar), the raindrop backscattering cross-section (${\sigma}b$) varies between successive maxima and minima as a function of the raindrop diameter (D) that are well described by Mie theory. The first Mie minimum in the backscattering cross-section occurs at D~1.68 mm, which translates to a raindrop terminal fall velocity of ${\sim}5.85m\;s^{-1}$ based on the Gunn and Kinzer relationship. Since raindrop diameters often exceed this size, the signal is captured in the radar Doppler spectrum, and thus, the location of the first Mie minimum can be used as a reference for retrieving the vertical air motion. The Mie technique is applied to radar Doppler spectra from the surface-based and airborne, upward pointing W-band radars. The contributions of aircraft motion to the vertical air motion are also described and further the first-order aircraft motion corrected equation is presented. The review also shows that the separate spectral peaks due to the cloud droplets can provide independent validation of the Mie technique retrieved vertical air motion using the cloud droplets as a tracer of vertical air motion.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.475-491
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• 2021

With the recent increase in available high-resolution (< ~1 m) satellite SAR images, the demand for precise registration of SAR images is increasing in various fields including change detection. The registration between high-resolution SAR images acquired in different look angle is difficult due to speckle noise and geometric distortion caused by the characteristics of SAR images. In this study, registration is performed in two stages, coarse and fine, using the x-band SAR data imaged at staring spotlight mode of TerraSAR-X. For the coarse registration, a method combining the adaptive sampling method and SAR-SIFT (Scale Invariant Feature Transform) is applied, and three rigid methods (NCC: Normalized Cross Correlation, Phase Congruency-NCC, MI: Mutual Information) and one non-rigid (Gefolki: Geoscience extended Flow Optical Flow Lucas-Kanade Iterative), for the fine registration stage, was performed for performance comparison. The results were compared by using RMSE (Root Mean Square Error) and FSIM (Feature Similarity) index, and all rigid models showed poor results in all image combinations. It is confirmed that the rigid models have a large registration error in the rugged terrain area. As a result of applying the Gefolki algorithm, it was confirmed that the RMSE of Gefolki showed the best result as a 1~3 pixels, and the FSIM index also obtained a higher value than 0.02~0.03 compared to other rigid methods. It was confirmed that the mis-registration due to terrain effect could be sufficiently reduced by the Gefolki algorithm.

• The Journal of Sustainable Design and Educational Environment Research
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• v.19 no.4
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• pp.15-25
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• 2020

The results of this research and analysis are as follows: First, it was possible to subdivide the increasing and decreasing trends of regional student numbers in Seoul into a total of 57 types by discovering additional 22 types through the Seoul City survey analysis of the 35 existing types, and it was found that there were 14 types that had not appeared in Seoul contrary to the nationwide appearance. Second, among the 43 types in Seoul, the most long-term decline types accounted for 71.3% in the order of A6 type> A8 type> A17 type> A2 type> A1 type> A18 type. The most long-term type of a new school was Nl4 type. Third, among the long-term decline types, there were many types that prevented the decrease in the number of students, such as the type A2, type A3, type A13, and type A15, in Gangnam School District 8, whereas in the non-Gangnam area, there were many other types of student decrease. The difference in distributions of types among regions was clearly seen. Therefore, in Seoul, which is mostly an urban area, it is necessary to carefully investigate and analyze the regional characteristics of each of the 11 Education Support Offices and to establish a school accommodation policy that reflects these results.

• Composites Research
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• v.35 no.3
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• pp.139-146
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• 2022

In this study, we study fabrication methods suitable for CNT fibers-based composite. We try to fabricate a composite material using a small amount of CNT fiber preparation of woven fabrics or stitched unidirectional fabrics consisting of CNT fiber is not achievable currently. The composite materials on the basis of CNT fibers have been mainly manufactured filament winding method due to productivity issues and difficulties in composite processes. We develop a new method to prepare CNT fibers-based composite using resin infiltrated CNT fibers-based films. Because CNT fibers have numerous nanopores inside, unnecessary resin can remain after curing and decrease the mechanical properties of the composites. To remove the excess resin, pressure should be applied during the process, but the pressure applied through VaRTM was not enough to remove the excess resin. To obtain the composite with high ratio of CNT fibers, higher pressure using hot press machine and foams next to the resin-infiltrated CNT fibers are necessary. We can obtain the composite having a mass ratio of 58.5 wt% based on the new suggested method and diluted epoxy. The specific strength of the composite reach 0.525 N/tex. This study presents a new process method that can be applied to the manufacturing of CNT fiber composite materials in the future.

• Journal of Korea Entertainment Industry Association
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• v.15 no.2
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• pp.149-157
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• 2021

One year has passed since the pandemic of COVID-19, which occurred in Wuhan, China, in November 2019 began. Worldwide, as of January 2021, more than 95 million people have been infected, and the death toll is higher than 2 million. In Korea, there are 74,262 infected and 1,328 dead, and government policies such as social distancing to prevent infection are being implemented. Accordingly, many inconveniences occurred in the physical activity environment, such as the closure of various sports facilities. It was necessary to consider physical activities to maintain healthy life while cooperating with the national policy while preventing infection. This study investigated the benefits of physical activity to reduce the risk of trichomoniasis and diabetes, improve bone mineral density, prolong healthy lifespan, maintain activity performance with aging, and improve psychological anxiety and depression. In addition, the physiological changes that may occur in the situation of stopping exercise due to social distancing to prevent COVID-19 infection were reviewed. In addition, moderate-intensity exercise that helps strengthen immune function by activating natural killer cells, neutrophils, and antibody responses was investigated. In addition, it reduces the level and function of blood B-cells, T-cells, and natural killer cells for several hours, decreases phagocytosis of neutrophils in the nasal cavity, increases inflammatory cytokines, decreases immune function, and increases infection. High-intensity exercise was considered. Therefore, in the age of COVID-19, long-term high-intensity exercise such as marathon, which causes impaired immune function, should be refrained from. And you should do moderate-intensity regular aerobic exercise such as fast walking to help prevent infection. It is also recommended to participate in resistance exercises to prevent loss of muscle mass.

• Journal of Korean Academy of Nursing
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• v.53 no.4
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• pp.468-479
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• 2023

Purpose: This study aimed to evaluate the use of the respiratory rate oxygenation (ROX) index, ROX-heart rate (ROX-HR) index, and saturation of percutaneous oxygen/fraction of inspired oxygen ratio (SF ratio) to predict weaning from high-flow nasal cannula (HFNC) in patients with respiratory distress in a pediatric intensive care unit. Methods: A total of 107 children admitted to the pediatric intensive care unit were enrolled in the study between January 1, 2017, and December 31, 2021. Data on clinical and personal information, ROX index, ROX-HR index, and SF ratio were collected from nursing records. The data were analyzed using an independent t-test, χ² test, Mann-Whitney U test, and area under the curve (AUC). Results: Seventy-five (70.1%) patients were successfully weaned from HFNC, while 32 (29.9%) failed. Considering specificity and sensitivity, the optimal cut off points for predicting treatment success and failure of HFNC oxygen therapy were 6.88 and 10.16 (ROX index), 5.23 and 8.61 (ROX-HR index), and 198.75 and 353.15 (SF ratio), respectively. The measurement of time showed that the most significant AUC was 1 hour before HFNC interruption. Conclusion: The ROX index, ROX-HR index, and SF ratio appear to be promising tools for the early prediction of treatment success or failure in patients initiated on HFNC for acute hypoxemic respiratory failure. Nurses caring for critically ill pediatric patients should closely observe and periodically check their breathing patterns. It is important to continuously monitor three indexes to ensure that ventilation assistance therapy is started at the right time.