• Journal of the Korean Society of Safety
• /
• v.30 no.6
• /
• pp.1-6
• /
• 2015

The actual condition is that environmental pollution due to the development of various industries has recently become a serious issue. An interest in improving the gas mileage is rising due to an increase in the number of vehicles in the era of high oil price in particular. In order to solve this problem, priority should be given to light-weight design of car body, However, at present, a design method enabling the conventional steel plate to be replaced is direly needed in order to guarantee passengers' safety according to excessive light-weight design of car body. In this study, in order to apply a design method that could realize fuel savings and environmental pollution prevention through an improvement in gas mileage together with meeting the safety requirements for vehicles, it was supposed that CFRP/Al composites member would be used as primary structural member. And to this end, it was intended to obtain optimum design data by experimentally implementing external impulsive load applied to the car body. According to results of impact test of CFRP/Al composites member, a collapsed shape of folding, crack, and bending occurred. So, it was possible to find that energy was observed. And in case of specimen having an angle of $90^{\circ}$ in the outermost layer and stack sequence of $[90^{\circ}{_2}/0^{\circ}2]s$, its collapsed length was shown to be short. Therefore, it was possible to find that the absorbed energy was shown to be higher by 20% or above at the maximum.

• Atmosphere
• /
• v.24 no.4
• /
• pp.523-532
• /
• 2014

In this study, thermal tropopause height defined from WMO (World Meteorological Organization) using temperature profile derived from Advance Microwave Sounding Unit-A (AMSU-A; hereafter named AMSU) onboard EOS (Earth Observing System) Aqua satellite is retrieved. The temperature profile of AMSU was validated by comparison with the radiosonde data observed at Osan weather station. The validation in the upper atmosphere from 500 to 100 hPa pressure level showed that correlation coefficients were in the range of 0.85~0.97 and the bias was less than 1 K with Root Mean Square Error (RMSE) of ~3 K. Thermal tropopause height was retrieved by using AMSU temperature profile. The bias and RMSE were found to be -5~ -37 hPa and 45~67 hPa, respectively. Correlation coefficients were in the range of 0.5 to 0.7. We also analyzed the change of tropopause height and temperature in middle troposphere in the extreme heavy rain event (23 October, 2003) associated with tropopause folding. As a result, the distinct descent of tropopause height and temperature decrease of ~8 K at 500 hPa altitude were observed at the hour that maximum precipitation and maximum wind speed occurred. These results were consistent with ERA (ECMWF Reanalysis)-Interim data (potential vorticity, temperature) in time and space.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2005.06a
• /
• pp.230-232
• /
• 2005

The formation of insoluble aggregation of the recombinant kringle fragment of human apolipoprotein(a), rhLK8, in endoplasmic reticulum was identified as the rate-limiting step in the rhLK8 secretion in Saccharomyces cerevisiae. To analyze the protein secretion pathway, some of yeast genes closely related to protein secretion was rationally selected and their oligomer DNA were arrayed on the chip. The expression profiling of these genes during the induction of rhLK8 in fermentor fed-batch cultures revealed that several foldases including pdi1 gene were up-regulated in the early induction phase, whereas protein transport-related genes were up-regulated in the late induction phase. The coexpression of pdi1 gene increased rhLK8-folding capacity. Hence, the secretion efficiency of rhLK8 in the strain overexpressing pdi1 gene increased by 2-fold comparing in its parental strain. The oligomer DNA chip arrayed with minimum number of the genes selected in this study could be generally applicable to the monitoring system for the heterologous protein secretion and expression in Saccharomyces cerevisiae. With the optimization of fed-batch culture conditions and the alteration of genetic background of host, we obtained extracellular rhLK8 at higher yields than with Pichia pastoris systems, which was a 25-fold increased secretion level of rhLK8 compared to the secretion level at the initiation of this study.

• Archives of Pharmacal Research
• /
• v.26 no.12
• /
• pp.1047-1054
• /
• 2003

Molecular chaperones have a crucial role in the folding of nascent polypeptides in endoplasmic reticulum. Some of them are known to be sensitive to the modification by electrophilic metabolites of organic pro-toxicants. In order to identify chaperone proteins sensitive to alkyators, ER extract was subjected to alkylation by 4-acetamido-4 -maleimidyl-stilbene-2,2 -disulfonate (AMS), and subsequent SDS-PAGE analyses. Protein spots, with molecular mass of 160, 100, 57 and 36 kDa, were found to be sensitive to AMS alkylation, and one abundant chaperon protein was identified to be protein disulfide isomerase (PDI) in comparison with the purified PDI. To see the reactivity of PDI with cysteine alkylators, the reduced form ($PDI_{red}$) of PDI was incubated with various alkylators containing Michael acceptor structure for 30 min at $38^{\circ}C$ at pH 6.3, and the remaining activity was determined by the insulin reduction assay. Iodoacetamide or N-ethylmaleimide at 0.1 mM remarkably inactivated $PDI_{red}$ with N-ethylmaleimide being more potent than iodoacetamide. A partial inactivation of $PDI_{oxid}$ was expressed by iodoacetamide, but not N-ethylmaleimide (NEM) at pH 6.3. Of Michael acceptor compounds tested, 1,4-benzoquinone ($IC_{50}, 15 \mu$ M) was the most potent, followed by 4-hydroxy-2-nonenal and 1,4-naphthoquinone. In contrast, 1,2-naphthoquinone, devoid of a remarkable inactivation action, was effective to cause the oxidative conversion of $PDI_{red}$ to $PDI_{oxid}$. Thus, the action of Michael acceptor compounds differed greatly depending on their structure. Based on these, it is proposed that POI, one of chaperone proteins in ER, could be susceptible to endogenous or xenobiotic Michael acceptor compounds in vivo system.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.3
• /
• pp.322-328
• /
• 2013

In this study, we show the expression and purification of the human recombinant farnesoid X receptor (FXR)- ligand binding domain (LBD) protein in E. coli using a double cistronic vector, pACYCDuet-1, as a soluble form. We describe here the expression and characterization of a biologically active $FXR-LBD_{(248-476)}$. When expressed in the influence of bacterial promoters ($P_{T7}$ and $P_{Tac}$) of the single cistronic expression vectors, the human recombinant $FXR-LBD_{(248-476)}$ was found to be totally insoluble. However, by using a double cistronic expression vector, we were able to obtain the human recombinant $FXR-LBD_{(248-476)}$ in a soluble form. To allow for biological activities, we have subcloned into the pACYCDuet-1 vector, expressed in E. coli cells at some optimized conditions, and purified and characterized the human recombinant active $FXR-LBD_{(248-476)}$ proteins using the fluorescence polarization assay. This suggests that the expression of FXR-LBD in a double cistronic vector improves its solubility and probably assists its correct folding for the biologically active form of the proteins. We suggest that this may represent a new approach to high expression of other nuclear receptors and may be useful as well for other classes of heterodimeric protein partners.

• Journal of Environmental Science International
• /
• v.11 no.2
• /
• pp.111-120
• /
• 2002

Asian dust(or yellow sand) occurs mainly in spring and occasionally in winter in east Asia, when the weather conditions are under an upper trough/cut-off low and surface high/low pressure system during blocking episode days associated with the stationary patterns of the upper level jet stream. The transport mechanism for Asian dust during the blocking episode days in spring 2001 was analyzed using the TOMS aerosol index and meteorological mesoscale model 5(MM5). Based on the E vector, an extension of an Eliassen-Palm flux, the blocking episode days were found to be associated with the development of an upper cut-off low and surface cyclones. Concurrently, the occurrence of dust storms was also determined by strong cold advection at the rear of a jet streak, which exhibited a maximum wind speed within the upper jet stream. As such, the transport mechanism for Asian dust from China was due to advection of the isentropic potential vorticity(IPV) and isentropic surfaces associated with tropopause folding. The transport heights for Asian dust during the blocking episode days were found to be associated with the distribution of the isentropes below the IPV At the same time, lee waves propagated by topography affected the downward motion and blocking of Asian dust in China. The Asian dust transported from the dust source regions was deposited by fallout and rain-out with a reinforcing frontogenesis within a surface cyclone, as determined from satellite images using TOMS and GMS5. Accordingly, these results emphasize the importance of forecasting jet streaks, the IPV, and isentropes with geopotential heights in east Asia.

• KIEAE Journal
• /
• v.16 no.4
• /
• pp.41-46
• /
• 2016

Purpose: This is a study on the planning of temporary housing for post application of Mega Sports facilities. The subject of the study is 2018 Pyeongchang Winter Olympics, which is to suggest building an alternative temporary housing using shipping containers(high cube), which solve the lack of accommodations and recycle temporary housing after Olympics, save money and be eco-friendly in Olympics. Method: This study includes this ; research on the a fact-finding survey about Mega sports facilities post application and demand survey on 2018 Pyeongchang Winter Olympics accomodations and an analysis about temporary housing plan. Furthermore we decided temporary housing building plan by analyzing residents' needs and traits of the housing etc. Through this, we made a schematic design for household units. Result: As a result, this study is a plan of making space, forms, and structure. The planned size is $38.4m^2$(L:12m, W:3.2m) except balcony, and indoor height is 2.5m. The space consists of entrance, bathroom, bedroom and living room with folding furniture system. Also there's a detailed floor plan of the ceiling, wall, and floor we drew up. The ceiling and wall consist of dampproof film, noncombustible board, fire proof urethane form, and color-designed sheet. The floor is composed of floor tile, cement mortar, light concrete(with heat coil), insulation, and dampproof film. Additionally, this study is a plan of interior dry wall with detail using modular construction method for work efficiency and quality improvement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.5 s.120
• /
• pp.503-510
• /
• 2007

This paper proposes the design scheme of internal triple band antenna intended for using in GSM900, DCS1800, and PCS1900 bands. The suggested folding metal plates of the two branches are mounted on a dielectric coated ground plane for size miniaturization and durability. Return losses are overlapped when length of metal branches are controlled. This is important technique for wide band operation. For the suggested antenna geometry its return loss was calculated by HFSS 9 simulator, and was shown to be -10 [dB] less within the required band. Also, gain and radiation pattern of antenna were measured using far field measurement system in an anechoic chamber. The measured peak gain is more than 3.0 [dBi], and the average gain is over -1.0 [dBi] for the triple band, which is regarded as satisfactory for the internal antenna application. Also, the radiation pattern for two frequencies shows a similar shape each other within the required band.

• Molecules and Cells
• /
• v.28 no.5
• /
• pp.479-487
• /
• 2009

Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semi-quantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to $H_2O_2$, menadione, and heavy metal ($CdCl_2$, $ZnCl_2$ and $AlCl_2$)-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to $H_2O_2$ stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.4
• /
• pp.570-583
• /
• 2021

Pyrococcus furiosus α-amylase can hydrolyze α-1,4 linkages in starch and related carbohydrates under hyperthermophilic condition (~ 100℃), showing great potential in a wide range of industrial applications, while its relatively low productivity from heterologous hosts has limited the industrial applications. Bacillus subtilis, a gram-positive bacterium, has been widely used in industrial production for its non-pathogenic and powerful secretory characteristics. This study was conducted to increase production of P. furiosus α-amylase in B. subtilis through three strategies. Initial experiments showed that co-expression of P. furiosus molecular chaperone peptidyl-prolyl cis-trans isomerase through genomic integration mode, using a CRISPR/Cas9 system, increased soluble amylase production. Therefore, considering that native P. furiosus α-amylase is produced within a hyperthermophilic environment and is highly thermostable, heat treatment of intact culture at 90℃ for 15 min was performed, thereby greatly increasing soluble amylase production. After optimization of the culture conditions (nitrogen source, carbon source, metal ion, temperature and pH), experiments in a 3-L fermenter yielded a soluble activity of 3,806.7 U/ml, which was 3.3- and 28.2-fold those of a control without heat treatment (1,155.1 U/ml) and an empty expression vector control (135.1 U/ml), respectively. This represents the highest P. furiosus α-amylase production reported to date and should promote innovation in the starch liquefaction process and related industrial productions. Meanwhile, heat treatment, which may promote folding of aggregated P. furiosus α-amylase into a soluble, active form through the transfer of kinetic energy, may be of general benefit when producing proteins from thermophilic archaea.