• Computers and Concrete
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• v.27 no.2
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• pp.111-130
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• 2021

In the present work, an extensive study for predicting efficiency parameters (��i) of various simulated nanocomposites including Polymethyl methacrylate (PMMA) as matrix and different structures including various sizes of graphene platelets (GPLs), single, double, and multi-walled carbon nanotubes (SWCNTs-DWCNTs-MWCNTs), and single and double-walled boron nitride nanotubes (SWBNNTs-DWBNNTs) are investigated. It should be stated that GPLs, carbon and boron nitride nanotubes (CNTs, BNNT) with different chiralities (5, 0), (5, 5), (10, 0), and (10, 10) as reinforcements are considered. In this research, molecular dynamics (MDs) method with Materials studio software is applied to examine the mechanical properties (Young's modulus) of simulated nanocomposite boxes and calculate η1 of each nanocomposite boxes. Then, it is noteworthy that by changing length (6.252, 10.584, and 21.173 nm) and width (7.137, 10.515, and 19.936) of GPLs, ��1, ��2, and ��3 approximately becomes (0.101, 0.114, and 0.124), (1.15, 1.22, and 1.26), (1.04, 1.05, and 1.07) respectively. After that efficiency parameters of SWCNTs, DWCNTs, and MWCNTs are calculated and discussed separately. Finally efficiency parameters of SWBNNTs and DWBNNTs with different chiralities by PMMA as matrix are determined by MD and discussed separately. It is known that the accurate efficiency parameters helps a lot to calculate the properties of nanocomposite analytically. In particular, the obtained results from this research can be used for analytical work based on the extended rule of mixture (ERM) in bending, buckling and vibration analysis of structure in future study.

• Journal of Korea Trade
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• v.23 no.5
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• pp.45-65
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• 2019

Purpose - As the well-known Structure-Conduct-Performance paradigm implies, risk structure of a corporation may affect its risk management activity and the activity may in turn determine its performance. Depending on its goal, Foreign Direct Investment (FDI) can shape its risk structure, risk management and its performance. Under this assumption, we investigate the relationship between the goals of FDI and risk management for the first time in academics. Design/methodology - This empirical research uses a survey of 279 current Korean enterprises' FDIs in China with the recently developed business risk quadrant model. Companies are classified into either a market- or an efficiency-seeking group, to identify how each group perceives and manages risks, and values the performance of risk management. Also, we apply integrated risk management method that multinational corporations have introduced in China, then verify the mediating effect between risk factors and performance. Findings - Our research shows the FDIs can expose themselves to differing risk structure although risk management activities simply represent the level of empowerment given to local management by headquarter due to limit of sample size despite diversity of risk and risk management tools. To sum, market seekers are found to have more strategic risk (revenue related risk) than efficiency seekers with financial risk (cost related risk). The market seekers can manage their risk by empowering their local organisation while the efficiency does the opposite ways. The risk management appears to be successful in general. Originality/value - Previous studies on small and medium enterprises' FDIs to China have concentrated on the analysis of entry determinants, withdrawal factors and individual risk management. Meanwhile, this research establishes enterprise-wide risk factors faced by the companies that advance into China, according to the method of the classification by ERM and verifies if they could synthetically improve performance through risk corresponding measures.

• Journal of Veterinary Science
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• v.21 no.4
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• pp.57.1-57.11
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• 2020

Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. Objectives: This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. Methods: A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. Results: Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. Conclusion: This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1537-1546
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• 2022

Staphylococcus aureus is a cause of high mortality in humans and therefore it is necessary to prevent its transmission and reduce infections. Our goals in this research were to investigate the frequency of methicillin-resistant S. aureus (MRSA) in Taif, Saudi Arabia, and assess the relationship between the phenotypic antimicrobial sensitivity patterns and the genes responsible for resistance. In addition, we examined the antimicrobial efficiency and application of silver nanoparticles (AgNPs) against MRSA isolates. Seventy-two nasal swabs were taken from patients; MRSA was cultivated on Mannitol Salt Agar supplemented with methicillin, and 16S rRNA sequencing was conducted in addition to morphological and biochemical identification. Specific resistance genes such as ermAC, aacA-aphD, tetKM, vatABC and mecA were PCR-amplified and resistance plasmids were also investigated. The MRSA incidence was ~49 % among the 72 S. aureus isolates and all MRSA strains were resistant to oxacillin, penicillin, and cefoxitin. However, vancomycin, linezolid, teicoplanin, mupirocin, and rifampicin were effective against 100% of MRSA strains. About 61% of MRSA strains exhibited multidrug resistance and were resistant to 3-12 antimicrobial medications (MDR). Methicillin resistance gene mecA was presented in all MDR-MRSA strains. Most MDR-MRSA contained a plasmid of > 10 kb. To overcome bacterial resistance, AgNPs were applied and displayed high antimicrobial activity and synergistic effect with penicillin. Our findings may help establish programs to control bacterial spread in communities as AgNPs appeared to exert a synergistic effect with penicillin to control bacterial resistance.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.211-218
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• 2023

A cryptic plasmid (pTH32) was characterized from Tetragenococcus halophilus 32, an isolate from jeotgal, Korean traditional fermented seafood. pTH32 is 3,198 bp in size with G+C content of 35.84%, and contains 4 open reading frames (ORFs). orf1 and orf2 are 456 bp and 273 bp in size, respectively, and their translation products showed 65.16% and 69.35% similarities with RepB family plasmid replication initiators, respectively, suggesting the rolling-circle replication (RCR) mode of pTH32. orf3 and orf4 encodes putative hypothetical protein of 186 and 76 amino acids, respectively. A novel Tetragenococcus-Escherichia coli shuttle vector, pMJ32E (7.3 kb, Em^r), was constructed by ligation of pTH32 with pBluescript II KS(+) and an erythromycin resistance gene (ErmC). pMJ32E successfully replicated in Enterococcus faecalis 29212 and T. halophilus 31 but not in other LAB species. A pepA gene, encoding aminopeptidase A (PepA) from T. halophilus CY54, was successfully expressed in T. halophilus 31 using pMJ32E. The transformant (TF) showed higher PepA activity (49.8 U/mg protein) than T. halophilus 31 cell (control). When T. halophilus 31 TF was subculturd in MRS broth without antibiotic at 48 h intervals, 53.8% of cells retained pMJ32E after 96 h, and only 2.4% of cells retained pMJ32E after 14 days, supporting the RCR mode of pTH32. pMJ32E could be useful for the genetic engineering of Tetragenococcus and Enterococcus species.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.256-262
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• 2015

In order to study the effect of the receptor protein (SeaR), which is isolated from Saccharopolyspora erythraea, we introduced the SeaR gene to Streptomyces virginiae as host strains. An effective transformation procedure for S. virginiae was established based on transconjugation by Escherichia coli ET12567/pUZ8002 with a ${\varphi}C31$-derived integration vector, pSET152, which contained int, oriT, attP, and $ermEp^{\ast}$ (erythromycin promotor). Therefore, the pEV615 was introduced into S. virginiae by conjugation and integrated at the attB locus in the chromosome of the recipients by the ${\varphi}C31$ integrase (int) function. Transformants of S. virginiae containing the SeaR gene were confirmed by PCR and transcriptional expression of the SeaR gene in the transformants was analyzed by RT-PCR, respectively. And, we examined the production time of virginiamycins in the culture media of both the transformants and the wild type. The production time of virginiamycins in the wild type and transformants was the same. When 100 ng/ml of synthetic $VB-C_6$ was added to the state of 6 or 8 hour cultivation of wild type and transformants, respectively, the virginiamycins production was induced, meaning that the virginiamycins production in the wild type was detected 2 h early than transformants. From these results, SeaR expression was also affected to virginiamycins production in transformants derived from S. virginiae. In this study, we showed that the SeaR protein worked as a repressor in transformants.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.39-47
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• 2015

Secondary metabolism in actinomycetes has been known to be controlled by a small molecule, ${\gamma}$-butyrolactone autoregulator, the binding of which to each corresponding receptor leads to the regulation of the transcriptional expression of the secondary metabolites. We expected that expression of an autoregulator receptor or a pleiotropic regulator in a non-host was to be gained insight of effective production of new metabolic materials. In order to study the function of the receptor protein (seaR), which is isolated from Saccharopolyspora erythraea, we introduced the seaR gene to Streptomyces coelicolor A3(2) as host strains. An effective transformation procedure for S. coelicolor A3(2) was established based on transconjugation by Escherichia coli ET12567/pUZ8002 with a ${\varphi}C31$-derived integration vector, pSET152, which contained int, oriT, attP and $ermEp^*$ (erythromycin promotor). Therefore, the pEV615 was introduced into S. coelicolor A3(2) by conjugation and integrated at the attB locus in the chromosome of the recipients by the ${\varphi}C31$ integrase (int) function. Exconjugant of S. coelicolor A3(2) containing the seaR gene was confirmed by PCR and transcriptional expression of the seaR gene in the transformant was analyzed by RT-PCR. In case of S. coelicolor A3(2), a phenotype microarray was used to analyze the phenotype of transformant compared with wild type by seaR expression. After that, in order to confirm the accuracy of the results obtained from the phenotype microarray, an antimicrobial susceptibility test was carried out. This test indicated that sensitivity of the transformant was higher than wild type in tetracycline case. These results indicated that some biosynthesis genes or resistance genes for tetracycline biosynthesis in transformant might be repressed by seaR expression. Therefore, subsequent experiments, analysis of transcriptional pattern of genes for tetracycline production or resistance, are needed to confirm whether biosynthesis genes or resistance genes for tetracycline are repressed or not.

• Particle and aerosol research
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• v.7 no.2
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• pp.49-57
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• 2011

High concentration of PM10 was reported on late July, 2005 in Seoul along with high particulate ion concentrations in PM2.5. To identify the reason for the severe air pollution episode, time series analysis of the PM10 concentration in the monitoring sites over Korea, wind sector analysis, trend analysis of the ion concentrations, and air mass trajectory analysis were carried out. It was found that the episode could be classified into two separate periods; first one between July 22 and 27 and second one between July 28 and 31. During the first period, the PM10 concentrations at Seoul were in good correlation with the PM10 concentration three hours before at Chuncheon. Trajectory analysis showed that air mass moved from north and turned to west at Kangwon province to Seoul. The concentrations of PM10 mass and ionic species were lower than the second period. During the second period, air mass moved from northern China to Seoul directly and the PM10 concentrations all over the mid-Korean peninsula showed the same trend. These observations suggest that the air pollution during the second period was affected by direct transport of air pollutants from northern China. Thus, the air quality at Seoul during both periods were influenced by long-range transport from outside rather than by local sources, but with different transport patterns.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.6
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• pp.123-154
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• 2002

Im Mittelpunkt der vorliegenden Arbeit steht die Untersuchung der Dynamik im System des deutschen Passivs mit dem $R\"{u}ckblick$ auf das Genuanische. Dabei steht es vorrangig im Zusammenhang mit der Grammatikalisierung der $Verbalf\"{u}gungen$ 'werden + PP' und 'sein + PP'. Und im heutigen deutschen Passivsystem ist zwar die $F\"{u}gung$ 'werden + PP' unmarkiert, aber im Genuanischen $\"{u}berwiegt\;die\;F\"{u}gung$ 'sein + PP'. Das Partizip der Kombination 'werden/sein + PP' wird im Gotischen $ausschlie{\ss}lich$ und im Althochdeutschen noch stellenweise flektiert. Hieraus darf geschlossen werden, dass im $Fr\"{u}hdeutschen$ das Verb finita und das Partizip als relativ $unabh\"{a}ngige$ Glieder einander $gegen\"{u}ber$ stehen und in einer Konstruktion verkettet werden, die einfach den Status der neuhochdeutschen periphrastischen Konstruktion aufweist. Die aspektuelle Bedeutung der $Passivf\"{u}gungen\;l\"{a}sst$ sich da als $bin\"{a}re$ Opposition von kategoriellen Merkmalen 'mutativ' (= Zustandswechel) und 'statal' (= Zustand), verteilt auf die F\"{u}gungen$ 'werden + PP' und 'sein + pp', beschreiben. Diese Merkmale kommt jeweils aus dem inchoativen bzw. durativen Verbalaspekt der Verba 'werden' bzw. 'sein' heraus. Diese Opposition unterscheidet sich von der neuhochdeutschen $Gegen\"{u}berstellung$ vom Vorgangspassiv und Zustandspassiv. Die Eigenbedeutung der Verben 'werden' und 'sein' $l\"{o}st$ sich nun, insbesondere im $Sp\"{a}talthochdeutschen$ in der Semantik der ganzen $F\"{u}gungen$ weitgehend auf, was seinerseits den Verlust der aspektualen Markiertheit der Passiv-Periphrasen mit den Verben finiten verursacht und ihre Entwicklung in Richtung auf die Paradigmatisierung der beiden $F\"{u}gungen\;erm\"{o}glicht$. Die weiter Entwicklung von $Passivf\"{u}gungen$ zeichnet sich durch eine zunehmende Expansion der $F\"{u}gung$ 'werden+PP' in die ursprungliche aspektuale $Sph\"{a}re$ der sein-Konstruktion aus. Dieser Prozess, der zur Auxilialisierung des Verbums finitum $f\"{u}hrt$, setzt schon im $Sp\"{a}talthochdeutschen$ ein und gelangt im Mittelhochdeutschen zur vollen $Auspr\"{a}gung$. Die Konkurrenz der beiden Passivkonstruktionen $f\"{u}hrt$ nun zur $allm\"{a}hlichen$ Verengung des aspektualen Bereichs der $F\"{u}gung$ '.sein+PP', $f\"{u}r$ die nun nur das Resultivum $\"{u}brig$ bleibt.

• Korean Security Journal
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• no.13
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• pp.327-350
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• 2007

Art. 2 Abs. 1 GG sch${\ddot{u}}$tzt umfassend die allgemeine Handlungsfreiheit. Daher bed${\ddot{u}}$rfen private Handlungen grunds${\ddot{a}}$tzlich keiner gesetzlichen Erm${\ddot{a}}$chtigungsgrundlage. Dies gilt selbstverst${\ddot{a}}$ndlich auch fur die Unternehmen der Bewachungsbranche. Allerdings ist es bei der Aus${\ddot{u}}$bung der Bewachungsaufgabe typisch, mit Strafe oder zumindest Schadensersatzpflicht sanktionierte Tatbest${\ddot{a}}$nde zum Nachteil Dritter zu verwirklichen. F${\ddot{u}}$r solche F${\ddot{a}}$lle stehen den Bewachungspersonen m${\ddot{o}}$glicherweise Rechtfertigungsgr${\ddot{u}}$nde zur Seite. Dadurch wird ein ansonsten rechtswidriges Handeln rechtm${\ddot{a}}$${\ss}$ig und so wird im Ergebnis eine Strafbarkeit (wie auch eine Schadensersatzpflicht) ausgeschlossen. Dabei wird klargestellt, dass dem Sicherheitsgewerbe au${\ss}$er in den F${\ddot{a}}$llen der gesetzlichen ${\ddot{U}}$bertragung der hoheitlichen Befugnisse nur die vom Auftraggeber vertraglich ${\ddot{u}}$bertragenen privatrechtlichen Befugnisse sowie die Jedermannsrechte zustehen Au${\ss}$erdem soll im Rahmen der Privatisierung der Gefahrenabwehraufgaben auf solche spezialgesetzlichen Regelungen hingewiesen werden, bei denen Bewachungspersonen mit der hoheitlichen Wahrnehmung bestimmter Sicherheitsaufgaben betraut, d.h. dazu befugt sind, Sicherheitsaufgaben in den Handlungsformen des ${\ddot{O}}$ffentlichen Rechts 면켜${\ddot{u}}$ben. In der koeranischen Literatur ist die Handlungsgrundlage des Bewachungspersonals bis jetzt kaum n${\ddot{a}}$her untersucht. Im allgemeinen werden strafrechtliche Rechtferigungsgr${\ddot{u}}$nde, z.B. Notwehr, Notstand und Selbsthilfe, als dabei anwendbare Normen anerkannt. In dieser Arbeit wird festgestellt, dass die privaten Sicherheitsdienstleister in beiden L${\ddot{a}}$ndern durch die Gewerbegenehmigung au${\ss}$er in den F${\ddot{a}}$llen der Beleihung keine hoheitlichen Befugnisse erhalten. Als Handlungsgrundlage kommen nur die allgemeinen Not- und Jedermannsrechte im Rahmen von Straf-Strafprozess- bzw. Zivilrecht in Betracht.