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Production of recombinant colicin M in Nicotiana tabacum plants and its antimicrobial activity
Ewelina Łojewska,Tomasz Sakowicz,Aleksandra Kowalczyk,Magdalena Konieczka,Janina Grzegorczyk,Przemysław Sitarek,Ewa Skała,Piotr Czarny,Tomasz Śliwiński,Tomasz Kowalczyk 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.1
Antibiotic-resistant microorganisms causing a life-threatening infection pose a serious challenge for modern science. The rapidly growing number of incidents for which the use of standard antibiotics is ineffective forces us to develop new alternative methods of killing microorganisms. Antimicrobial proteins and peptides (AMPs) can be promising candidates to solve this problem. Colicin-M is one of the representatives of this group and is naturally produced by Escherichia coli acting on other closely related bacterial strains by disrupting their outer cell membrane. This bacteriocin has huge potential as a potent antimicrobial agent, especially, since it was recognized by the FDA as safe. In this work, we present the expression of colicin M in model transgenic Nicotiana tabacum L. plants. We demonstrate that purified colicin retains its antibacterial activity against the control Escherichia coli strains and clinical isolates of Escherichia coli and Klebsiella pneumoniae. Our results also show that plant-derived ColM is not toxic for L929 and HeLa cell line, which allows us to suppose that plant-based expression could be an alternative production method of such important proteins.
Modification of Polyurethane Foams with 1,3,5-Triazine Ring and Boron
Ewelina Chmiel,Jacek Lubczak,Ryszard Stagraczyński 한국고분자학회 2017 Macromolecular Research Vol.25 No.4
Boric acid was hydroxyalkylated with glycidol and ethylene carbonate. The product of hydroxyalkylation of boric acid was used to modify oligoetherol obtained from melamine and propylene carbonate. The obtained mixture was further used to get polyurethane foams (PUFs) by reaction with diphenylmethane isocyanate in presence of water. The foaming with diphenylmethane isocyanate containing 30 % tri-functional isocyanates resulted in formation of polyurethane foams of enhanced thermal resistance and diminished flammability in comparison with analogous PUFs based on 1,3,5-triazine ring.
Ewelina Lacka 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07
The literature suggests that the adoption and use of social media can derive a number of benefits to B2B firms (see Siamagka et al, 2015; Wang et al, 2016). Despite the benefits however, the adoption and use of social media in B2B setting is slow (Lacka and Chong, 2016), so is research examining social media adoption by B2B firms (Iankova et al, 2018). To date, only a handful of studies explored factors driving social media use for B2B marketing purposes (Siamagka et al, 2015; Lacka and Chong, 2016). Lacka and Chong (2016), for example, revealed that practical acceptability (perceived usefulness, usability and utility) drives adoption decision. They ignored however the role of social acceptability, referred to social factors, which according to Nielsen (1993) is crucial in the technology adoption decision. Social factors are conceptualised as subjective norms or group norms, which motive persuasion of specific behaviour (e.g. technology use). The importance of assessing social acceptability has been most recently highlighted by Brink (2017), who recognises the key role of leadership from senior managers in the adoption and use of social media by B2B firms. Empirical research is however yet to verify such an impact. In addition to limited research on B2B social media adoption, there is lack of research on the role culture plays in the adoption decision. Previous research has showed hat culture impacts adoption of social media and its use (e.g. Hsu et al, 2015). Yet, there is lack of research on the impact of culture on the social media adoption in B2B setting. This study aims to address this research gap. Specifically, in line with this conference call this study aims to examine the impact of Chinese culture on social media adoption by B2B marketing professionals. This will be achieved though exploratory quantitative study.
Ewelina Lacka,Mike Williams 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07
Existing literature provides strong evidence to suggest that e-commerce adoption is subject to the effect of culture. In this stream, researchers adopting Hofstede’s framework (1980) conceptualise culture at the aggregate level, and thus they assume country’s cultural homogeneity. Yet, the argument emerges that this view does not seem to be appropriate anymore, as every country having its unique mix of ethnic groups portrays cultural diversity (Cleveland and Laroche, 2007). Research exploring the adoption of e-commerce by ethnic minority consumers however, is scarce (Lacka and Yip, 2018). Considering growing migration levels, and particularly intra-European migration as well as the increase of ethnic consumers internet use (Kizgin et al, 2018), the investigation of migrants’ attitudes and behavioural intentions toward adopting e-commerce, as well as factors affecting adoption decision are important research topics for researchers, practitioners and policy makers. Although technology adoption has been extensively researched, previous studies on e-commerce adoption suffer from two limitations, which this study aims to address. First, most research on e-commerce adoption considers consumers to be a homogeneous group. However, within group differences exist, and they have an impact on the e-commerce adoption decision. So far however, only a handful of studies have explored the role of consumers’ individual characteristics on behavioural intentions to adopt e-commerce (e.g. Hasan 2010). Second, although the effect of culture on e-commerce adoption has been extensively studied, the simultaneous impact of various cultural influences that migrants are subject to has not been examined. To address these research gaps, the aim of this research is to assess the role of individual characteristics in e-commence adoption, and to reveal the impact of contact with heritage and host cultures on ethnic minority consumers’ attitudes towards behavioural intentions to adopt e-commerce.
Polyurethane Foams with 1,3,5-Triazine Ring and Silicon Atoms
Jacek Lubczak,Ewelina Chmiel 한국고분자학회 2019 Macromolecular Research Vol.27 No.6
The method of obtaining polyurethane foams based on two oligoetherols, synthesized from (1) melamine and propylene carbonate, and (2) from metasilicic acid, glycidol and ethylene carbonate, is elaborated. The physical properties of PUFs are tested depending on composition of oligoetherol substrates mixture used. It has been found that 1,3,5-triazine rings in PUF increase their thermal resistance, while silicon contributes to improvement of mechanical properties of PUF. The siliconmodified P U Fs c an s tand l ong term h eating a t 150-200oC with concomitant increase of compression strength and decrease of flammability of PUFs. The PUFs heated at 150 oC for one month become self-extinguishing, or even inflammable upon exposure at 175 oC.
Oxidation of 1,2-cyclohexanediol as a step for adipic acid synthesis
Kamil Peckh,Dawid Lisicki,Ewelina Pabich,Beata Orlinska 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-
Adipic acid is the most important of the commercially available aliphatic dicarboxylic acids. It is obtainedindustrially from cyclohexanone and/or cyclohexanol by oxidation with nitric acid(V). One of the byproductsof the process is nitrous oxide, which is difficult to utilize. In this paper we propose an alternativemethod of adipic acid synthesis. In the first stage, cyclohexene is oxidized with hydrogen peroxide toepoxide, which hydrolyses to 1,2-cyclohexanediol that in the second stage is then oxidized with oxygen. From an environmental point of view, this two-stage method can offer a significant and attractive reductionof N2O production compared to the industrial methods. We apply a simple catalytic system composedof transition metal compounds and HNO3 or organic nitrites, to the second stage of adipic acidsynthesis synthesis, namely 1,2-cyclohexenediol oxidation using oxygen.
Novel sugar-based nickel-tungsten carbide catalysts for dry reforming of hydrocarbons
Izabela Wysocka,Natalia Czaplicka,Ewelina Pawelczyk,Jakub Karczewski,Joanna Sobczak,Zuzanna Bielan,Michał Maciejewski,Barbara Koscielska,Andrzej Rogala 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-
The search for new materials for dry reforming of hydrocarbons with high activity, stability, and ease ofsynthesis is still one of the main directions of research in the field of heterogeneous catalysis. Traditionalmethods of carbide synthesis require the use of combustible gases of petrochemical origin. The search fornew catalysts based on renewable and safe carbon sources is highly demanded. Therefore, we report WCand Ni-WC catalysts prepared using glucose, sucrose, fructose and trehalose. The materials were characterizedusing XRD, AAS, H2-TPR, SEM, TEM, Raman spectroscopy, FTIR, CO2-TPD, TG/DTG BET and BJHmethods. The catalytic activity was investigated in the dry reforming of methane and plastics. The sugartype used for the preparation determined crystal structure and therefore catalytic properties of Ni-WCcatalysts. The most active and stable catalyst was prepared using sucrose. It was observed that catalystsobtained with the use of sugars containing fructose in their structure are characterized by smaller WCand Ni crystallites, which have a direct impact on high catalytic activity. The catalytic activity of the mostactive catalyst Ni-WC_S was examined in the dry reforming of plastics.The highest syngas generation wasobserved for low-density polyethylene reforming reaching 75.58 mmol/g plastic.
Jagoda Płaczkiewicz,Paulina Chmiel,Ewelina Malinowska,Pawel Bącal,Agnieszka Kwiatek 한국미생물학회 2020 The journal of microbiology Vol.58 No.5
Neisseria gonorrhoeae, an obligatory human pathogen causes the sexually transmitted disease gonorrhea, which remains a global health problem. N. gonorrhoeae primarily infects the mucosa of the genitourinary tract, which in women, is colonized by natural microbiota, dominated by Lactobacillus spp., that protect human cells against pathogens. In this study, we demonstrated that precolonization of human epithelial cells with Lactobacillus crispatus, one of the most prevalent bacteria in the female urogenital tract, or preincubation with the L. crispatus enolase or glutamine synthetase impairs the adhesion and invasiveness of N. gonorrhoeae toward epithelial cells, two crucial steps in gonococcal pathogenesis. Furthermore, decreased expression of genes encoding the proinflammatory cytokines, TNFα and CCL20, which are secreted as a consequence of N. gonorrhoeae infection, was observed in N. gonorrhoeae-infected epithelial cells that had been precolonized with L. crispatus or preincubated with enolase and glutamine synthetase. Thus, our results indicate that the protection of human cells against N. gonorrhoeae infection is a complex process and that L. crispatus and its proteins enolase and glutamine synthetase can have a potential role in protecting epithelial cells against gonococcal infection. Therefore, these results are important since disturbances of the microbiota or of its proteins can result in dysbiosis, which is associated with increased susceptibility of epithelium to pathogens.