• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.04a
• /
• pp.112-112
• /
• 2019

Baicalein is one of the main flavonoids derived from roots of Scutellaria baicalensis Georgi, a traditional Oriental medicine. Although baicalein has high antitumor effect on several human carcinomas, the mechanism responsible for this property is not unclear. In this study, the data revealed that baicale-ininduced growth inhibition was associated with the induction of apoptosis connecting with cytochrome c release, down-regulation of anti-apoptotic Bcl-xl and increased the percentage of cells with a loss of mitochondria membrane permeabilization. Baicalein also induced the proteolytic activation of caspases and cleavage of PARP; however, blockage of caspases activation by z-VAD-fmk inhibited baicalein-induced apoptosis. In addition, baicalein enhanced the formation of autophagosomes and up-regulated LC3-II/LC3-I ratio. Interestingly, the pretreatment of bafilomycin A1 recovered baicalein-induced cell death suggesting that autophagy by baicalein roles as protective autophagy. Taken together, our results indicated that this flavonoid induces apoptosis and cell protective autophagy. These data means combination treatment with baicalein and autophagy inhibitor might be a promising anticancer drug.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.31 no.1
• /
• pp.32-36
• /
• 2021

This study was investigated in carbon diffusion behavior of laser-carburized TiZrN coating layer and the changes of mechanical properties. The carbon paste was deposited on TiZrN coatings, and the laser was irradiated to carburize into the coatings. The XRD peak corresponding to the (111) plane shifted to a lower angle after the carburization, showing the lattice expansion by doped carbon. The decreased grain size implied the compression by the grain boundary diffusion of carbon. The XPS spectra for the bonding states of carbon was analyzed that carbon was substitute to nitrogen atoms in TiZrN, as carbide, through the thermal energy of laser. In addition, the combination of sp2 and sp3 hybridized bonds represented the formation of an amorphous carbon. The cross-sectional TEM image and the inverse FFT of the TiZrN coating after carburizing were observed as the wavy shape, confirming the amorphous phase located in grain boundaries. After the carburization, the hardness increased from 34.57 GPa to 38.24 GPa, and the friction coefficient decreased by 83 %. In particular, the ratio of hardness and elastic modulus (H/E) which is used as an index of the elastic recovery, increased from 0.11 to 0.15 and the wear rate improved by 65 %.

• Conservation Science in Museum
• /
• v.25
• /
• pp.35-50
• /
• 2021

This study analyzed the basic properties of soil material gathered around Maegok-dong in Gwangju, Gyeonggi-do Province (hereafter, "Maegok soil") and the physicochemical changes in the Maegok soil resulting from the addition of other clay materials in order to present scientific information about the properties of clay available for pottery production. Gravel, coarse sand, and fine sand account for 73% of the total mass of the Maegok soil. Therefore, it required refinement through sifting in order to serve in pottery clay. After sifting, the amount of silt and clay in the soil increased to 95% of the total mass. However, since it lacked plasticity and viscosity, buncheong soil was added. When it was mixed with bungcheong soil at a ratio of 7:3, Maegok soil improved as pottery clay as its viscosity increased, demonstrating compositional properties appropriate for ceramic clay even after firing. Further, its water-absorption rate was decreased to 0.40. This means that soil gathered from anywhere can be used for pottery-making by refining its original properties and through mixture with clay with specific components which help the pottery maintain its shape even after firing.

• Journal of Korea Water Resources Association
• /
• v.54 no.2
• /
• pp.121-133
• /
• 2021

Suspended Solids (SS) generated in rivers are mainly introduced from non-point pollutants or appear naturally in the water body, and are an important water quality factor that may cause long-term water pollution by being deposited. However, the conventional method of measuring the concentration of suspended solids is labor-intensive, and it is difficult to obtain a vast amount of data via point measurement. Therefore, in this study, a model for measuring the concentration of suspended solids based on remote sensing in the Nakdong River was developed using Sentinel-2 data that provides high-resolution multi-spectral satellite images. The proposed model considers the spectral bands and band ratios of various wavelength bands using a machine learning model, Support Vector Regression (SVR), to overcome the limitation of the existing remote sensing-based regression equations. The optimal combination of variables was derived using the Recursive Feature Elimination (RFE) and weight coefficients for each variable of SVR. The results show that the 705nm band belonging to the red-edge wavelength band was estimated as the most important spectral band, and the proposed SVR model produced the most accurate measurement compared with the previous regression equations. By using the RFE, the SVR model developed in this study reduces the variable dependence compared to the existing regression equations based on the single spectral band or band ratio and provides more accurate prediction of spatial distribution of suspended solids concentration.

• Animal Bioscience
• /
• v.35 no.1
• /
• pp.54-63
• /
• 2022

Objective: This study aimed to evaluate the replacement of degummed soybean oil (DSO) by acid soybean oil (ASO) in diets with or without the inclusion of emulsifier on broiler performance, relative organ weight, lipase activity, intestinal morphometry, and nutrient digestibility. Methods: A total of 704 1-day-old male broiler chicks were allotted to a 2×2 completely randomized factorial design (with or without emulsifier × two lipid sources [ASO and DSO]), with eight replicates and 22 birds each. The metabolizable energy level in diets with emulsifier was reduced by 40 kcal/kg from 1 to 21 d and 50 kcal/kg from 22 to 49 d. Results: Broilers fed diets containing ASO without emulsifier had higher (p = 0.005) weight gain than DSO-fed animals and with the inclusion of emulsifier had worse (p = 0.018) feed conversion ratio (FCR). Birds fed diets with emulsifier worsened FCR regardless of lipid source from 1 to 21 days (p = 0.006) and from 1 to 49 days (p = 0.0002). There was an increase (p = 0.026) in the relative pancreas weight, at 14 days, in birds fed diets containing ASO. Lipase activity and morphometry of the duodenum and jejunum, at 14 and 21 days, were not affected (p>0.05). The dietary inclusion of emulsifier improved the digestible energy (p = 0.053) in the presence of ASO. For the digestibility coefficients (gross energy, crude protein, and mineral matter), no interference was observed (p>0.05). Conclusion: The inclusion of emulsifier to energy-restricted diet with ASO maintained broiler performance in the first week, but worsened FCR in subsequent phases. The ASO can be considered as an alternative lipid source to DSO and does not interfere with the morphophysiological characteristics and performance of broilers. The combination of ASO and emulsifier increased the digestible energy content by 6.2%.

• The Korea Journal of Herbology
• /
• v.27 no.6
• /
• pp.29-35
• /
• 2012

Objectives : To observe the effect of 4 kinds of Korean medicine and complex extracts on the anti-stress of chronic mild stress Rat model, so as to find out the machanism of its pharmacological effects. Methods : 64 healthy SD Rats were randomly divided into 8 groups. Model Design by chronic stress(CSM), and carried out the forced swimming test. We investigated the body weight, feed and water intake, feed conversion ratio and measured parameters to changes in swimming time, immobility time, 2 and 24 hours of feces, corticosterone hormone and blood glucose level. Results : In this experiments, body weight gain and feed intake were higher in all korean medicinal herb group. Swimming time were increased by Zizyphus jujuba and Gagamsanzointang(SZT) groups and immobility time was significantly lower by Zizyphus jujuba and Fluoxetine(FLX) groups. The result of corticosterone hormone level were significantly lower in Fluoxetine(FLX) and Gagamsanzointang(SZT) but blood glucose was not significantly difference. In 2 hours after fecal frequency result were significantly lower in Zizyphus jujuba group. but SZT group were increased. This result caused by acute stress but 24 hours of feces were restored to normal. Conclusions : 5 kind of Korean Medicinal Herbs extracts has good anti-stress effects, and also to clear the circulatory system and regulate blood glucose and improve bowel function. We suggest that use a single Korean medicine rather than the combination to relieve stress.

• Journal of Korea Water Resources Association
• /
• v.55 no.12
• /
• pp.1065-1076
• /
• 2022

The purpose of this study was to investigate the effect of the expansion and withering of Salix subfragilis communities on the water quality in Namgang Dam reservoir. The distribution area of the Salix subfragilis communities was 0.12 km² in 2003 for the first time, but it was 3.58 km² in 2019, which has increased rapidly by about 30 times in 16 years. However, in 2013, the distribution area has decreased by 0.17 km² due to long-term immersion in high turbidity, and self-thinning in Salix subfragilis communities. The lake characteristics of reservoir showed a combination of lake type and river type in terms of average water depth, watershed area/lake surface area ratio, water residence time, flushing rate, and stratification. From the result of analyzing long-term changes in lake water quality, COD, TP, and chlorophyll-a in Salix subfragilis communities were significantly larger than those in the three points located in the central part of reservoir. In particular, the fact that the value of chlorophyll-a showed the maximum value in winter rather than summer, unlike the trend of the three points in the Namgang Dam water quality monitoring network, is thought to have occurred internally rather than externally. It can be estimated that one cause of this deterioration of the water quality in Namgang Dam reservoir is the huge amount of nutrients generated in the decomposition process of by-products such as fallen leaves, branches and withered trees in Salix subfragilis communities.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.23 no.1
• /
• pp.29-37
• /
• 2023

Background: A high incidence (40-73%) of postoperative nausea and vomiting (PONV) has been reported following orthognathic surgery, and various risk factors have been associated with it. Identifying PONV risk factors based on initial onset time will help establish preventive measures. This study aimed to identify factors that are significantly related to PONV based on the initial onset time after orthognathic surgery. Methods: This study included 590 patients who underwent orthognathic surgery. Multivariate logistic regression analysis was performed to identify the risk factors that are significantly related to PONV. The objective variables were classified into three categories: no PONV, early PONV (initial onset time: 0-2 h after anesthesia), and late PONV (initial onset time: 2-24 h after anesthesia). The explanatory variables included relevant risk factors for PONV, as considered in previous studies. Results: Total intravenous anesthesia with propofol was a significant depressant factor for early PONV (adjusted odds ratio [aOR] = 0.340, 95% confidence interval [CI] = 0.209-0.555) and late PONV (aOR = 0.535, 95% CI = 0.352-0.814). The administration of a combination of intraoperative antiemetics (vs. no administration) significantly reduced the risk of early PONV (aOR = 0.464, 95% CI = 0.230-0.961). Female sex and young age were significant risk factors for late PONV (aOR = 1.492, 95% CI = 1.170-1.925 and unit aOR = 1.033, 95% CI = 1.010-1.057, respectively). Conclusion: We identified factors that are significantly related to PONV based on the initial onset time after orthognathic surgery. Total intravenous anesthesia with propofol significantly reduced the risk of PONV not only in the early period (0-2 h after anesthesia) but also in the late period (2-24 h after anesthesia).

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.5
• /
• pp.462-469
• /
• 2023

In this study, we propose a method for evaluating the risk of collision between ships to support determination on the risk of collision in a situation in which ships encounter each other and to prevent collision accidents. Because several uncertainties are involved in the navigation of a ship, must be considered when evaluating the risk of collision. We apply the Dempster-Shafer theory to manage this uncertainty and evaluate the collision risk of each target vessel in real time. The distance at the closest point approach (DCPA), time to the closest point approach (TCPA), distance from another vessel, relative bearing, and velocity ratio are used as evaluation factors for ship collision risk. The basic probability assignments (BPAs) calculated by membership functions for each evaluation factor are fused through the combination rule of the Dempster-Shafer theory. As a result of the experiment using automatic identification system (AIS) data collected in situations where ships actually encounter each other, the suitability of evaluation was verified. By evaluating the risk of collision in real time in encounter situations between ships, collision accidents caused by human errora can be prevented. This is expected to be used for vessel traffic service systems and collision avoidance systems for autonomous ships.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.4
• /
• pp.54-63
• /
• 2022

A 3-tonf class liquid rocket engine that powers the upper stage of a small launcher and lifts 500 kg payload to 500 km SSO is designed. The small launcher is to utilize the flight-proven technology of the 75-tonf class engine for the first stage. A combination of liquid oxygen and liquid methane has been selected as their cryogenic states can provide an extra boost in specific impulse as well as enable a weight saving via the common dome arrangement. An expander cycle is chosen among others as the low-pressure operation makes it robust and reliable while a specific impulse of over 360 seconds is achievable with the nozzle extension ratio of 120. Key components such as combustion chamber and turbopump are designed for additive manufacturing to a target cost. The engine system provides an evaporated methane for the autogenous pressurization system and the reaction control of the stage. This upper stage propulsion system can be extended to various missions including deep space exploration.