• YAKHAK HOEJI
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• v.40 no.1
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• pp.102-111
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• 1996

LB10522 is a new parenteral broad spectrum cephalosporin with a catechol moiety at C-7 position of beta-lactam ring. This compound can utilize tonB-dependent iron transp ort system in addition to porin proteins to enter bacterial periplasmic space and access to penicillin-binding proteins (PBPs) which are the lethal targets of ${\beta}$-lactam antibiotics. The chelating activity of LB10522 to metal iron was measured by spectrophotometrically scanning the absorbance from 200 to 900nm. When $FeCl_3$ was added, optical density was increased between 450 and 800nm. LB10522 was more active against gram-negative strains in iron-depleted media than in iron-replete media. This is due to the increased expression of iron transport channels in iron-depleted condition. LB10522 showed a similar activity against E. coli DC2 (permeability mutant) and E. coli DCO (wild type strain) in both iron-depleted and iron-replete media, indicating a minimal permeaility barrier for LB10522 uptake. LB10522 had high affinities to PBP 3 and PBP 1A, 1B of E. coli. By blocking these proteins, LB10522 caused inhibition of cell division and the eventual death of cells. This result was correlated well with the morphological changes in E. coli exposed to LB10522. Although the in vitro MIC of LB10522 against P. aeruginosa 1912E mutant (tonB) was 8-times higher than that of the P. aeruginosa 1912E parent strain, LB10522 showed a similar in vivo protection efficacy against both strains in the mouse systemic infection model. This result suggested that tonB mutant, which requires a high level of iron for normal growth, might have a difficulty in surviving in their host with an iron-limited environment.

• Journal of The Korean Astronomical Society
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• v.50 no.5
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• pp.151-155
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• 2017

We investigate the radio properties of the dwarf galaxy SDSS J133245.62+263449.3 which shows optical signatures of black hole activity. Dwarf galaxies are known to host intermediate mass black holes (IMBHs) with masses $M_{BH}{\sim}10^{4-6}M_{\odot}$, some of them being radio loud. Recently, Reines et al. (2013) found dwarf galaxy candidates which show signatures of being black hole hosts based on optical spectral lines. SDSS J133245.62+263449.3 is one of them; it shows a flux density of ~ 20 mJy at 1.4 GHz, which corresponds to $L_{1.4GHz}{\sim}10^{23}W\;Hz^{-1}$. This is much brighter than other black hole host dwarf galaxies. However, star formation activity can contribute to radio continuum emission as well. To understand the nature of the radio emission from SDSS J133245.62+263449.3, we imaged this radio loud dwarf galaxy at low frequencies (325 MHz and 610 MHz) using the Giant Metrewave Radio Telescope (GMRT). We present here the high resolution images from our GMRT observations. While we detect no obvious extended emission from radio jets from the central AGN, we do find the emission to be moderately extended and unlikely to be dominated by disk star formation. VLBI observations using the Korean VLBI Network (KVN) are now being planned to understand the emission morphology and radiation mechanism.

• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.351-365
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• 2011

The purpose of this study is to investigate how regional resource-based industries affect regional economic space. To achieve this goal, a new framework has been proposed, which integrates traditional firm network models in economic geography with the concept of value chain. Firms' networks are elaborated and classified by firm activities along with global value chain. Firm-activities are composed of primary activities and supportive activities. Primary activities include, production, sales, and marketing. Support activities are conceptualized as networks of R&D and of firm support services. On the basis of this framework, fermented soy product industry, representative industry of regional resource-based industries in Korea, is analyzed. Finally, this study shows the dynamics of regional resource-based industry.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.3
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• pp.294-301
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• 2020

Man-In-Simulant Test(MIST) provides a test method to evaluate chemical protective equipments such as protective garments, gloves, footwear and gas mask. The MIST chamber is built to control concentration of chemical vapor that has a activity space for two persons. Non-toxic methyl-salicylate(MeS) is used to simulate chemical agent vapor. We carried out to measure inward leakage MeS vapors by using passive adsorbent dosimeter(PAD) which are placed on the skin at specific locations of the body while man is activity according to the standard procedure in MIST chamber. But more time is required for PADs and there is concern of contamination in PADs by recovering after experiment. Therefore detector for measuring in real time is necessary. In order to analyze in real time the contamination of the personal protective equipment inside the chemical environment, we have developed a wireless real-time gas detector. The detector consists of 8 gas-sensors and 1 control-board. The control-board includes a CPU for processing a signal, a power supply unit for biasing the sensor and Bluetooth-chipset for transmission of signals to external PC. All signals from gas-sensors are converted into digital signals simultaneously in the control-board. These digital signals are stored in external PC via Bluetooth wireless communication. The experiment is performed by using protective equipment worn on manikin. The detector is mounted inside protective equipment which is capable of providing a real-time monitoring inward leakage MeS vapor. Developed detector is demonstrated the feasibility as real-time detector for MIST.

• Journal of Korean Elementary Science Education
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• v.31 no.1
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• pp.40-56
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• 2012

The purpose of this study was to understand the teaching effects after conducting ASI module in the open inquiry activities of the elementary science class. in order to understand the effects of ASI(Authentic Scientific Inquiry) module application using science research notes in open inquiry activities to students' science research ability. The results of this study were as follow. First, the after test results were covariance-analyzed to be the effects to science process skills were statistically significant in 0.5 significance level. Second, in the covariance analysis of the after test of the study group and the comparative group, the effects to scientific creative problem solving skills were statistically significant in 0.5 significance level. Third, the covariance analysis of the after test in the effects of ASI module application using science notebooks to students' scientific attitude revealed that the two groups' average difference was statistically significant in 0.5 significance level. In conclusion, application of the ASI module using science notebooks had a positive effect on improvements of students' science process skills, science creative problem solving ability and scientific attitude. Therefore, the ASI module using science notebooks is hopefully to be provided as an effective instructive strategy in the open inquiry activities courses in school in the future.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.194-201
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• 2004

Core-wall construction method is applied in many high-rise building constructions. This is caused by the advantages of the method such as the effect of saved construction cost and shortened period. However, the analysis study of planning practice for core-wall construction shows matters take place during core-wall construction, such as increasing in construction cost and period. These matters result from the limited work space leading to low productivity, the activity interference leading to increasing in period, additional temporary work cost and time, and delayed concrete pour activity. A large part of these can be prevented taking place by very detailed and most careful core-wall construction plan. Therefore, this study suggests improvement directions of core-wall construction planning process focused on the cooperation system of a contractor between a sub-contractor and the process.

• Journal of Microbiology
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• v.38 no.4
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• pp.218-223
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• 2000

Using two drugs, tunicamycin and brefeldin A, which affect protein processing, we investigated the intracellular processing mechanism of secreted aspartyl proteinase 1 (SAPl) of Candide albicans. Three intracellular forms of SAPI were detected by immunoblotting using menoclonal antibody (MAb) CAPl. Their molecular weights were approximately 40, 41 and 45 kDa, respectively. The 41 kDa protein is a glycoprotein and may be the same as the extracellular form judging by its molecular mass. The 40 kDa protein was the unglycosylated form and its molecular mass coincided with deglycosylated SAPl and the 45 kDa protein was also the unglycosylated form. Neither the 40 and 45 kDa proteins were detected in the culture supernatant of C. albicans. These suggested that the 40 and 45 kDa proteins might be intracellular precursor forms of SAPI. These results show that SAPI is translated as a 45 kDa precusor form in the endoplasmic reticulum and the 45 kDa precursor farm undergoes proteolytic cleavage after translocation into the Golgi apparatus, generating the 40 kDa precursor form. This 40 kDa precursor is converted into a 41 kDa mature form through glycosylation in the Golgi apparatus. The mature form of the 41 kDa protein is sorted into secretary vesicles and finally released into the extracellular space through membrane fusion. When the glycan region of SAPl was digested with N-glycosidase F, both stability and activity of the enzyme decreased. These results indicate that the glycan attached to the enzyme may, at least in parti be related to enzyme stability and activity.

• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.130-138
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• 1998

In this study, the effect of verapamil (VER) on cyclosporin A (CsA)-induced nephrotoxicity was investigated in uninephrectomized rats. Male Wistar rats were administered CsA (50 mg/kg/day, p.o.) or VER (0.5 mg/kg/day, i.p.) with CsA (50 mg/kg/day, p.o.) for 20 days. The urinary N-acetyl-$\beta$-D-glucosaminidase (NAG) activity along with BUN, serum creatinine, creatinine clearance (CLcr), body weight, and 24 hr-urine output were measured and histopathologic changes of kidney were evaluated by light and electron microscopy. The results obtained from this study can be summarized as follows: While NAG activity, BUN and serum creatinine was progressively increased and CLcr significantly decreased in CsA group, VER almost signifi-cantly (p<0.05) suppressed and normalized CsA-induced changes in VER+CSA group. While urine output increased until 12th days and thereafter progressively decreased in CsA group, it gradually increased in control and VER+CSA group. While body weight progressively made a gain in control and VER+CSA groups, it significantly (p<0.05) lost in CsA group. On light microscopy, the glomerular hyperemia and proximal convoluted tubular (PCT) dilatation, focal tubular cell vacuolation and necrosis were clearly evident in CsA group, but, were not seen in other groups. Ultrastructural studies revealed thickened glomerular endothelium and basal lamina of capillary, irregular shaped pedicels of podocytes, indistinct slit pores and narrowed bowman's space. The large oval vacuoles with dense debris and phagosome were distributed in apical zone and deformed microvilli and mitochondria were seen in the PCT cell of CsA group. But, glomeruli and PCT cell were relatively preserved in normal apperance in other groups. In conclusion, it is suggested that verapamil has a protective effect on cyclosporine-induced nephrotoxicity in uninephrectomized rats.

• Molecules and Cells
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• v.38 no.8
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• pp.715-722
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• 2015

In Gram-negative bacteria in the periplasmic space, the dimeric thioredoxin-fold protein DsbC isomerizes and reduces incorrect disulfide bonds of unfolded proteins, while the monomeric thioredoxin-fold protein DsbA introduces disulfide bonds in folding proteins. In the Gram-negative bacteria Salmonella enterica serovar Typhimurium, the reduced form of CueP scavenges the production of hydroxyl radicals in the copper-mediated Fenton reaction, and DsbC is responsible for keeping CueP in the reduced, active form. Some DsbA proteins fulfill the functions of DsbCs, which are not present in Gram-positive bacteria. In this study, we identified a DsbA homologous protein (CdDsbA) in the Corynebacterium diphtheriae genome and determined its crystal structure in the reduced condition at $1.5{\AA}$ resolution. CdDsbA consists of a monomeric thioredoxin-like fold with an inserted helical domain and unique N-terminal extended region. We confirmed that CdDsbA has disulfide bond somerase/reductase activity, and we present evidence that the N-terminal extended region is not required for this activity and folding of the core DsbA-like domain. Furthermore, we found that CdDsbA could reduce CueP from C. diphtheriae.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.427-436
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• 2021

The article reveals and theoretically substantiates the trends of foreign language teachers' professional training in universities of Ukraine in terms of European integration, which are systematized in three areas: macro-level (system of education), meso-level (universities) and micro-level (subjects of educational process). The article aims to substantiate the trends of foreign language teacher training in the context of European integration and the main directions of creative use of constructive ideas of European experience in the innovative development of education. The article lights up the system for improving foreign language teacher training in universities, which is based on updated goals, content and approaches to the implementation of basic concepts, principles and features of teacher training in European experience, enable us to improve the quality of teacher training, its competitiveness in the European labor market. In the article developed the conceptual model of strategic development of the university in the conditions of European integration. It is emphasized that information technologies provide great opportunities for the development of professional skills and intellectual potential of future professionals. At present, the computerization of the educational process in higher education institutions is considered as one of the first and most promising areas for improving the quality of education. The article offered directions of internationalization of educational activity of university in the conditions of European integration. Diagnostic tools for the development of the university in terms of integration into the European educational space, individual rating and ranking of structural units of the university have been developed; main directions of activity of the laboratory of the skill of the teacher of higher school and methodical recommendations on the creation and the organization of work of scientific laboratories.