• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6073-6080
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• 2015

Background: Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24), a unique tumor suppressor gene, has killing activity in a broad spectrum of cancer cells. Herein, plasmids producing mda-7 proteins fused to different RGD peptides (full RGD4C and shortened RGD, tRGD) were evaluated for apoptosis induction with a hepatocellular carcinoma cell line, Hep-G2. The study aim was to improve the apoptosis potency of mda-7 by tethering to RGD peptides. Materials and Methods: Three plasmids including mda-7, mda-7-RGD and mda-7-tRGD genes beside a control vector were transfected into Hep-G2 cells. After 72 hours incubation, cell viability was evaluated by MTT assay. In addition, the rate of apoptosis was analyzed by flow cytometry using PI/annexin staining. To detect early events in apoptosis, 18 hours after transfection, expression of the BAX gene was quantified by real time PCR. Modeling of proteins was also performed to extrapolate possible consequences of RGD modification on their structures and subsequent attachment to receptors. Results and Conclusions: In MTT assays, while all mda-7 forms showed measurable inhibition of proliferation, unmodified mda-7 protein exhibited most significant effect compared to control plasmid (P<0.001). Again, flow cytometry analysis showed a significant apoptosis induction by simple mda-7 gene but not for those RGD-fused mda-7 proteins. These findings were also supported by expression analysis of BAX gene (P<0.001). Protein modelling analysis revealed that tethering RGD at the end of IL-24/Mda7 disrupt attachment to cognate receptor, IL-20R1/IL-20R2. In conclusion, fusion of RGD4C and shortened RGD peptides to carboxyl terminal of mda7, not only reduce apoptosis property in vitro but also disrupt receptor attachment as demonstrated by protein modelling.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1295-1305
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• 2021

Satellite-derived ocean color products are required to effectively monitor clear open ocean and coastal water regions for various research fields. For this purpose, accurate correction of atmospheric effect is essential. Currently, the Geostationary Ocean Color Imager (GOCI)-II ground segment uses the reanalysis of meteorological fields such as European Centre for Medium-Range Weather Forecasts (ECMWF) or National Centers for Environmental Prediction (NCEP) to correct gas absorption by water vapor and ozone. In this process, uncertainties may occur due to the low spatiotemporal resolution of the meteorological data. In this study, we develop water vapor absorption correction model for the GK-2 combined GOCI-II atmospheric correction using Advanced Meteorological Imager (AMI) total precipitable water (TPW) information through radiative transfer model simulations. Also, we investigate the impact of the developed model on GOCI products. Overall, the errors with and without water vapor absorption correction in the top-of-atmosphere (TOA) reflectance at 620 nm and 680 nm are only 1.3% and 0.27%, indicating that there is no significant effect by the water vapor absorption model. However, the GK-2A combined water vapor absorption model has the large impacts at the 709 nm channel, as revealing error of 6 to 15% depending on the solar zenith angle and the TPW. We also found more significant impacts of the GK-2 combined water vapor absorption model on Rayleigh-corrected reflectance at all GOCI-II spectral bands. The errors generated from the TOA reflectance is greatly amplified, showing a large error of 1.46~4.98, 7.53~19.53, 0.25~0.64, 14.74~40.5, 8.2~18.56, 5.7~11.9% for from 620 nm to 865 nm, repectively, depending on the SZA. This study emphasizes the water vapor correction model can affect the accuracy and stability of ocean color products, and implies that the accuracy of GOCI-II ocean color products can be improved through fusion with GK-2A/AMI.

• Fashion & Textile Research Journal
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• v.20 no.5
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• pp.616-620
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• 2018

Recently, many researches have been conducted to improve the performance and wearability of smart wearables. In this study, we designed and fabricated the signal and power transmission textile cables for smart wearables which have excellent wearability, durability and reliability. For the signal transmission textile cables, conductive yarns for the signal line and the ground line were developed. Three types of signal transmission textile cables have been developed using the conductive yarns. Linear density, tensile properties, electrical resistance and RF characteristics were tested to characterize the physical and electrical properties of three signal transmission textile cables. The conductive yarns have the very low resistance of $0.05{\Omega}/cm$ and showed excellent uniformity of electric resistance. Therefore, the electrical resistance of the signal transmission fiber cable can be reduced by increasing the number of conductive yarns used in signal and ground lines. However, the radio frequency (RF) characteristics of the signal transmission textile cables were better as the number of strands of the conductive yarns used was smaller. This is because the smaller the number of strands of conductive yarn used in signal transmission textile cables, the narrower and more parallel the distance between the signal line and the ground line. It is expected that the signal and power transmission textile cable for signal and power transmission will be utilized in smart wearable products.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.169-176
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• 2017

Casting process includes wax pattern, investment, dewaxing, curing, casting, etc., and each single process is important to achieve a good result. Since 2000, 3D printers have been developed and widely used; as more prefer UV Curavle resin method over wax method, resultant casting defects have become worse. To resolve such problem, preceding research revealed casting defects of existing wax method. In particular, defects of UV Curavle resin method showed difference in investment, dewaxing, deresinating and curing compared to the existing one. Accordingly, results were presented through casting tests; especially, a temperature rising curve only for UV Curavle resin was shown rather than one for the existing method. Lastly, this research classified those not available with direct casting and suggested mold manufacturing. This research is expected to be useful for 3D printer users or those who would conduct direct casting with UV Curavle resin.

• Journal of the Korean Institute of Gas
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• v.16 no.2
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• pp.60-66
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• 2012

With diversification of research and development activity according to fusion of state-of-the-art technology, potential hazard and risk factors in new forms have been increased in the laboratories. Also, as there are many cases where the experimental condition is extremely high/low temperature and pressure, many many accidents producing loss of life and/or injuries occur due to the extreme condition. In this study, The common fact questionnaire as the survey tool for the establishment of the accident prevention countermeasure in laboratory have been developed to safety security of the laboratory workers. The current status of chemical materials and the realization of important on laboratory safety management using the questionnaire investigated by an electronic mail and visiting survey in the laboratories and universities. The collected data was analyzed with Excel program and it can be utilized as basic data for accident prevention in laboratories.

• Safety and Health at Work
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• v.1 no.2
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• pp.192-200
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• 2010

Objectives: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. Methods: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). Results: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. Conclusion: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.

• Genes and Genomics
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• v.40 no.12
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• pp.1259-1267
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• 2018

Litchi (Litchi chinensis Sonn.) is an important subtropical fruit crop with high commercial value due to its high nutritional values and favorable tastes. However, irregular bearing attributed to unstable flowering is a major ongoing problem for litchi producers. Previous studies indicate that low-temperature is a key factor in litchi floral induction. In order to reveal the genetic and molecular mechanisms underlying the reproductive process in litchi, we had analyzed the transcriptome of buds before and after low-temperature induction using RNA-seq technology. A key flower bud differentiation associated gene, a homologue of FLORICAULA/LEAFY, was identified and named LcLFY (GenBank Accession No. KF008435). The cDNA sequence of LcLFY encodes a putative protein of 388 amino acids. To gain insight into the role of LcLFY, the temporal expression level of this gene was measured by real-time RT-PCR. LcLFY was highly expressed in flower buds and its expression correlated with the floral developmental stage. Heterologous expression of LcLFY in transgenic tobacco plants induced precocious flowering. Meantime, we investigated the sub-cellular localization of LcLFY. The LcLFY-Green fluorescent protein (GFP) fusion protein was found in the nucleus. The results suggest that LcLFY plays a pivotal role as a transcription factor in controlling the transition to flowering and in the development of floral organs in litchi.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.549-560
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• 2021

Forces exerted on a shield TBM (tunnel boring machine) such as cutter head torque, thrust force, chamber pressure, and upward force are key factors determining TBM performance. However, the forces acting on the TBM when tunnelling the mixed ground have different tendencies compared to that of the uniform ground, which could impair TBM performance. In this study, the effect of mixed ground tunnelling was numerically investigated with torque, thrust force, chamber pressure, and upward force. A coupled discrete element method (DEM) and finite difference method (FDM) model for TBM driving model was used. This numerical study simulates TBM tunnelling in mixed ground composed of upper weathered granite soil and lower weathered rock. The effect on the force acting on the TBM according to the location and slope of the boundary of the mixed ground was numerically examined.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.451-463
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• 2016

We explore the impact of Chinese future air pollutant emissions on ozone air quality in Northeast Asia (NEA) and health in South-Korea using an assessment framework including ICAMS (The Integrated Climate and Air Quality Modeling System) and BenMAP (The Environmental Benefits Mapping and Analysis Program). The emissions data sets from the climate change scenarios, the Representative Concentration Pathways (RCPs) (emission scenarios, EMSO), are used to simulate ozone air quality in NEA in the current (1996~2005, 2000s), the near future (2016~2025, 2020s) and the distant future (2046~2055, 2050s). Furthermore, the simulated ozone changes in the 2050s are used to analyze ozone-related premature mortality and economic cost in South-Korea. While different EMSOs are applied to the China region, fixed EMSO are used for other country regions to isolate the impacts of the Chinese emissions. Predicted ozone changes in NEA are distinctively affected by large changes in NOx emission over most of China region. Comparing the 2020s with the 2000s situation, the largest increase in mean ozone concentrations in NEA is simulated under RCP 8.5 and similarly small increases are under other RCPs. In the 2050s in NEA, the largest increase in mean ozone concentrations is simulated under RCP 6.0 and leads to the occurrence of the highest premature mortalities and economic costs in South-Korea. Whereas, the largest decrease is simulated under RCP 4.5 leads to the highest avoided premature mortality numbers and economic costs. Our results suggest that continuous reduction of NOx emissions across the China region under an assertive climate change mitigation scenario like RCP 4.5 leads to improved future ozone air quality and health benefits in the NEA countries including South-Korea.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1782-1789
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• 2012

We have developed a novel type of polymer nanogel loaded with anticancer drug based on bio-derived poly(${\gamma}$-glutamic acid) (${\gamma}$-PGA). ${\gamma}$-PGA is a highly anionic polymer that is synthesized naturally by microbial species, most prominently in various bacilli, and has been shown to have excellent biocompatibility. Thiolated ${\gamma}$-PGA was synthesized by covalent coupling between the carboxyl groups of ${\gamma}$-PGA and the primary amine group of cysteamine. Doxorubicin (Dox)-loaded ${\gamma}$-PGA nanogels were fabricated using the following steps: (1) an ionic nanocomplex was formed between thiolated ${\gamma}$-PGA as the negative charge component, and Dox as the positive charge component; (2) addition of poly(ethylene glycol) (PEG) induced hydrogen-bond interactions between thiol groups of thiolated ${\gamma}$-PGA and hydroxyl groups of PEG, resulting in the nanocomplex; and (3) disulfide crosslinked ${\gamma}$-PGA nanogels were fabricated by ultrasonication. The average size and surface charge of Dox-loaded disulfide cross-linked ${\gamma}$-PGA nanogels in aqueous solution were $136.3{\pm}37.6$ nm and $-32.5{\pm}5.3$ mV, respectively. The loading amount of Dox was approximately 38.7 ${\mu}g$ per mg of ${\gamma}$-PGA nanogel. The Dox-loaded disulfide cross-linked ${\gamma}$-PGA nanogels showed controlled drug release behavior in the presence of reducing agents, glutathione (GSH) (1-10 mM). Through fluorescence microscopy and FACS, the cellular uptake of ${\gamma}$-PGA nanogels into breast cancer cells (MCF-7) was analyzed. The cytotoxic effect was evaluated using the MTT assay and was determined to be dependent on both the concentration and treatment time of ${\gamma}$-PGA nanogels. The bio-derived ${\gamma}$-PGA nanogels are expected to be a well-designed delivery carrier for controlled drug delivery applications.