Poznań University of Economics and Business

Zinc oxide (ZnO) has broad applications in various areas. Nanoparticle synthesis using plants is an alternative to conventional physical and chemical methods. It is known that the biological synthesis of nanoparticles is gaining importance due to its simplicity, eco-friendliness and extensive antimicrobial activity. Also, in this study we report the synthesis of ZnO nanoparticles using Trifolium pratense flower extract. The prepared ZnO nanoparticles have been characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) with Energy dispersive X-ray analysis (EDX). Besides, this study determines the antimicrobial efficacy of the synthesized ZnO nanoparticles against clinical and standard strains of S. aureus and P. aeruginosa and standard strain of E. coli.

Do government interventions aimed at curbing the spread of COVID-19 affect stock market volatility? To answer this question, we explore the stringency of policy responses to the novel coronavirus pandemic in 67 countries around the world. We demonstrate that non-pharmaceutical interventions significantly increase equity market volatility. The effect is independent from the role of the coronavirus pandemic itself and is robust to many considerations. Furthermore, two types of actions that are usually applied chronologically particularly early-information campaigns and public event cancellations-are the major contributors to the growth of volatility.

This paper is a tribute to researchers who have significantly contributed to improving and advancing structural equation modeling (SEM). It is, therefore, a brief overview of SEM and presents its beginnings, historical development, its usefulness in the social sciences and the statistical and philosophical (theoretical) controversies which have often appeared in the literature pertaining to SEM. Having described the essence of SEM in the context of causal analysis, the author discusses the years of the development of structural modeling as the consequence of many researchers' systematically growing needs (in particular in the social sciences) who strove to effectively understand the structure and interactions of latent phenomena. The early beginnings of SEM models were related to the work of Spearman and Wright, and to that of other prominent researchers who contributed to SEM development. The importance and predominance of theoretical assumptions over technical issues for the successful construction of SEM models are also described. Then, controversies regarding the use of SEM in the social sciences are presented. Finally, the opportunities and threats of this type of analytical strategy as well as selected areas of SEM applications in the social sciences are discussed.

A system that allows museums to build and manage Virtual and Augmented Reality exhibitions based on 3D models of artifacts is presented. Dynamic content creation based on pre-designed visualization templates allows content designers to create virtual exhibitions very efficiently. Virtual Reality exhibitions can be presented both inside museums, e.g. on touch-screen displays installed inside galleries and, at the same time, on the Internet. Additionally, the presentation based on Augmented Reality technologies allows museum visitors to interact with the content in an intuitive and exciting manner.

AIMS: Functional mitral regurgitation (FMR) contributes to morbidity and mortality in heart failure (HF) patients. The aim of this study was to determine whether percutaneous mitral annuloplasty could safely and effectively reduce FMR and yield durable long-term clinical benefit. METHODS AND RESULTS: The impact of mitral annuloplasty (Carillon Mitral Contour System) was evaluated in HF patients with at least moderate FMR. Patients in whom the device was placed then acutely recaptured for clinical reasons served as a comparator group. Quantitative measures of FMR, left ventricular (LV) dimensions, New York Heart Association (NYHA) class, 6 min walk distance (6MWD), and quality of life were assessed in both groups up to 12 months. Safety and key functional data were assessed in the implanted cohort up to 24 months. Thirty-six patients received a permanent implant; 17 had the device recaptured. The 30-day major adverse event rate was 1.9%. In contrast to the comparison group, the implanted cohort demonstrated significant reductions in FMR as represented by regurgitant volume [baseline 34.5 ±11.5 mL to 17.4 ±12.4 mL at 12 months (P < 0.001)]. There was a corresponding reduction in LV diastolic volume [baseline 208.5 ±62.0 mL to 178.9 ±48.0 mL at 12 months (P =0.015)] and systolic volume [baseline 151.8 ±57.1 mL to 120.7 ±43.2 mL at 12 months (P =0.015)], compared with progressive LV dilation in the comparator. The 6MWD markedly improved for the implanted patients by 102.5 ±164 m at 12 months (P =0.014) and 131.9 ±80 m at 24 months (P < 0.001). CONCLUSION: Percutaneous reduction of FMR using a coronary sinus approach is associated with reverse LV remodelling. Significant clinical improvements persisted up to 24 months.

Aspects related to the growing pollution of the natural environment and depletion of conventional fossil fuels have become the motive for searching for ecofriendly, renewable, and sustainable alternative energy sources. Particular attention is paid to industrial waste, especially waste of biomass materials, which can be converted into biofuels and energy that meets the growing needs of humanity. The use of biomass for energy purposes is less damaging to the environment, the materials are low-cost, locally available in large quantities, and create employment opportunities for workers in suburban and rural areas around the world. This article discusses issues related to the use of waste biomass materials as renewable energy sources. The current energy situation in the world is analyzed in terms of production, consumption, and investments in green energy. Types of biomass and individual physicochemical and energy properties of waste plant materials obtained for energy purposes are described. Currently available methods of converting biomass into energy, including mechanical, thermal, and biochemical techniques are discussed. The conducted analysis indicates the possibility of using it as a competitive source of electricity and heat. Understanding the properties of biomass materials allows us to understand the right way to use them for energy and reduce the consumption of fossil fuels in the future.

Purpose This paper aims to identify new directions for research into customer‐to‐customer interaction (CCI). It also aims to examine thematically the main achievements of two decades of CCI research. Design/methodology/approach Consultations both with CCI experts and with experts from a selection of management fields were undertaken. A selective literature review, based on an extensive search of the CCI literature, was conducted. Findings A large number of opportunities for future investigation are identified. A significant quantity of CCI literature is revealed. CCI is shown to be conceptually quite complex. Convincing evidence supports the claim that CCI has now joined the mainstream of services marketing. Practical implications For service management researchers, a number of service management topics, such as service recovery, SST, e‐service, and ergonomics, are shown to have CCI‐related aspects worthy of research attention. For service managers, the emphasis on showing the relevance of CCI, and the possibilities for influencing CCI, should encourage them to incorporate CCI considerations into their strategic and operational plans. Originality/value The wide‐ranging proposals for future research into CCI will undoubtedly stimulate investigation of many new avenues of CCI. Service management researchers are provided with a concise, thematic guide to the most influential CCI literature; the article contributes to the service‐dominant logic literature by broadening the discussion of the customer as an operant resource.

Polyphenolic antioxidants exhibited a dose-dependent toxicity against human promyelocytic leukemia cells (HL-60). Their action was accompanied by malondialdehyde formation, and was partly prevented by desferrioxamine and the antioxidant N,N'-diphenyl-p-phenylene diamine. This points to a prooxidant character of their cytotoxicity. A quantitative structure-activity relationship (QSAR) has been obtained to describe the cytotoxicity of 13 polyphenolic antioxidants belonging to three different groups (flavonoids, derivatives of gallic and caffeic acid): log cL50 (microM) = (2.7829+/-0.2339)+(1.2734+/-0.4715) Ep/2 (V)-(0.3438+/-0.0582) log P (r2 = 0.8129), where cL50 represents the concentration for 50% cell survival, Ep/2 represents the voltammetric midpoint potential, and P represents the octanol/water partition coefficient. Analogous QSARs were obtained using enthalpies of single-electron oxidation of these compounds, obtained by quantum-mechanical calculations. These findings clearly point to two important characteristics determining polyphenol cytotoxicity, namely their ease of oxidation and their lipophilicity.

The dynamic changes in tertiary education that were observed in Poland for the last 20 years transformed the Polish educational market and led to the immense expansion of educational institutions. The rapid increase in the number of students that continued until 2006 is however over and Polish universities have begun to compete for their clients. Increased competition along with the pessimistic forecasts for Poland with regard to demographic changes result in the growing demand for the knowledge on determinants of student educational choices and satisfaction. Although the amount of studies in this field is growing, Poland is still substantially underrepresented in the current research. The purpose of this article was to examine the underlying factors behind the choices that Polish students make while pursuing their tertiary education. The research method that combines focus groups’ discussions and a survey study among 1,420 business major students helped us to identify the factors behind three phases of the decision making process: pursuing higher education; information search along with final choice of a university; and satisfaction from chosen studies. Our research implies that decision making with regard to tertiary education is multifaceted and longitudinal as it combines a different set of factors in each stage of the decision making process.

The effect of water- and steam-cooking on the content of vitamin C, polyphenols, carotenoids, tocopherols and glucosinolates, as well as on the antioxidant activity of broccoli, are reported. Flavonoids, phenolic acids, vitamins C and E, beta-carotene, lutein, and glucosinolates in domestically processed broccoli were quantified using high-performance liquid chromatography (HPLC) methods; total polyphenols were determined with Folin-Ciocalteu reagent. The antioxidant capacities of broccoli extracts were evaluated using the Trolox equivalent antioxidant capacity (TEAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. The results indicated that steam-cooking of broccoli results in an increase in polyphenols, as well as the main glucosinolates and their total content as compared with fresh broccoli, whereas cooking in water has the opposite effect. Steam-cooking of broccoli has no influence on vitamin C, whereas cooking in water significantly lowers its content. Both, water- and steam-cooking of broccoli results in an increase in beta-carotene, lutein, and alpha- and gamma-tocopherols as compared with fresh broccoli. Similar effects of steaming and water-cooking of broccoli on their antioxidant activity were observed.

Besides their positive role, microorganisms are related to a number of undesirable effects, including many diseases, biodeterioration and food spoilage, so when their presence is undesired, they must be controlled. Numerous biocides limiting the development of microorganisms have been proposed, however, in this paper the biocidal and inhibitory activity of quaternary ammonium salts (QASs) and their zwitterionic derivatives is addressed. This paper presents the current state of knowledge about the biocidal activity of QAS and their derivatives. Moreover, the known mechanisms of antimicrobial activity and the problem of emerging resistance to QAS are discussed. The latest trends in the study of surfactants and their potential use are also presented.

In the present study, the pH-dependent free radical-scavenging activity of betanin in the Trolox equivalent antioxidant capacity (TEAC) assay was determined. It was found that at a pH > 4 betanin is about 1.5-2.0-fold more active than some anthocyanins considered very good free radical scavengers as determined in the TEAC assay. The increase in the TEAC values of betanin with increasing pH is discussed in terms of its calculated phenolic OH homolytic bond dissociation energy (BDE) and ionization potential (IP). The results suggest that the exceptionally high antioxidant activity of betanin is associated with an increasing of its H-donation and electron-donation ability when going from cationic state to mono-, di- and tri-deprotonated states present at basic solutions.

Salinization of soils and freshwater resources by natural processes and/or human activities has become an increasing issue that affects environmental services and socioeconomic relations. In addition, salinization jeopardizes agroecosystems, inducing salt stress in most cultivated plants (nutrient deficiency, pH and oxidative stress, biomass reduction), and directly affects the quality and quantity of food production. Depending on the type of salt/stress (alkaline or pH-neutral), specific approaches and solutions should be applied to ameliorate the situation on-site. Various agro-hydrotechnical (soil and water conservation, reduced tillage, mulching, rainwater harvesting, irrigation and drainage, control of seawater intrusion), biological (agroforestry, multi-cropping, cultivation of salt-resistant species, bacterial inoculation, promotion of mycorrhiza, grafting with salt-resistant rootstocks), chemical (application of organic and mineral amendments, phytohormones), bio-ecological (breeding, desalination, application of nano-based products, seed biopriming), and/or institutional solutions (salinity monitoring, integrated national and regional strategies) are very effective against salinity/salt stress and numerous other constraints. Advances in computer science (artificial intelligence, machine learning) provide rapid predictions of salinization processes from the field to the global scale, under numerous scenarios, including climate change. Thus, these results represent a comprehensive outcome and tool for a multidisciplinary approach to protect and control salinization, minimizing damages caused by salt stress.

AM, = 390,000 complex of eukaryotic initiation factor 2 (eIF-2; 3 subunits, M, = 38, 52, and 55 X lo3) and a factor required for catalytic recycling of eIF-2 (eIF-2B; 5 subunits, M, = 26, 39, 58,67, and 82 X lo3) has been purified from rabbit reticulocyte lysate.The eIF-2 eIF-2B complex can be dissociated into free eIF-2B and eIF-2 by high salt or phosphorylation of the M, = 38,000 eIF-2a subunit at physiologic salt concentrations.elF-2 elF-2B association promotes formation of the eIF-2 Met-tRNAi.GTP ternary compIex at physiologic concentrations of GTP and GDP.The basis of this activity appears to be an increase in the KOGDp of eIF-2 from 3.1 X to 1.8 X lo" M when associated with eIF-2B.elF-2B, itself, does not have any intrinsic Met-tRNAi binding activity and binding of the ternary eIF-2.Met-tRNAi*GTP complex to initiating 43 S ribosomal subunits appears to be preceded by eIF-2 * elF-2B dissociation.While the addition of free elF-2 to inhibited hemindeficient reticulocyte lysates restores the synthesis of an equivalent amount of globin, both free eIF-2B and eIF-2.eIF-2Bcatalyze the synthesis of 30-40 pmol of globin/pmol of factor.Alternatively, control rates of protein synthesis in hemin-deficient lysates can be immediately restored by increasing the Concentration of GTP to 1 mM.These data indicate that the inhibition of eIF-2 recycling in hemin-deficient lysates is the result of its altered interaction with eIF-2B which interferes with the GTP exchange required for eIF-2-GDP reactivation.Eukaryotic initiation factor 2 occupies a central role in the mechanism of translational regulation by hemin (1, see reviews in Refs.2-5), the oxidation/reduction state of pyridine nucleotides and thiols (6, 7), the energy charge of the adenine and guanine nucleotide pools (8), amino acid starvation (for review see Ref. 9), and viral infection (see reviews in Refs.2, 10, and 11).In hemin-deficient reticulocyte lysates, phosphorylation of eIF-2' was thought to be directly responsible for the inhibition of protein synthesis initiation (12-17, also see reviews in Refs. 2 and 3).A more complex mechanism is required, however, since phosphorylation of eIF-2a does not directly inhibit formation of the eIF-2 e Met-tRNA, .

Purpose A city's resident population is strategically the most valuable segment among those targeted by place marketing practitioners. Residents' quality of life and their satisfaction with their city of residence should be the ultimate aim of place management. The aim of this paper is, therefore, to develop a conceptualisation of place satisfaction for city residents that can be applied by place managers. Design/methodology/approach By reviewing prior definitions and conceptualisations of the related concepts of quality of life and satisfaction, a model of city resident place satisfaction is presented. Findings From a broad survey of the literature, three main fields were identified that have dealt with satisfaction – psychology, sociology and human ecology, and marketing. Drawing on, and integrating insights from, these separate, yet interrelated fields, the concept of resident place satisfaction is established and then the identified components of the working model of resident place satisfaction are presented. Practical implications The tensions facing place managers in satisfying internal targets' interests are outlined, followed by examples of performance measures and indicators designed to support place managers' complex task of positively shaping the lifestyles of their city inhabitants, workers and pleasure seekers. Originality/value The sub‐field of place management and marketing has emerged in the last decade and recognises satisfaction with a place as important, but, as yet, this concept remains theoretically undeveloped. This paper draws on concepts from other, related disciplines to establish the concept of resident place satisfaction as a contribution to the theory and practice of place management.

Industry 4.0 heralds the profound transformation of business models by enabling the fusion of virtual and real worlds and the application of digitization, automatization and robotics in manufacturing. We review the basic premises of Industry 4.0 and map them against the clusters’ features with the aim to establish the kind of relations between these two categories. By exploring the likely impact of clusters on Industry 4.0, our discussion revolves around the broader question of the role of regional ecosystems in industrial transformation. Clusters, thanks to the advantages such as knowledge base and mechanisms, agglomeration economies and externalities (labour pool and critical mass of firms) and favourable more stable, less uncertain environment of trust and cooperation, may facilitate the digital transformation, particularly its phasing-in and testing phases. Notwithstanding this potential, it should be stressed that not all clusters would be able to play such prominent role. Only these equipped with adequate knowledge base and providing some expertise in the field of IT solutions, robotics, automatics, and so on, i.e. the technologies crucial to Industry 4.0 seem predestined to contribute to the emergence of fully fledged industrial internet. Despite seemingly some inconsistency between these two categories, clusters can facilitate the business transformation towards Industry 4.0.

Counterfeiting of food is recently one of the risks relevant for producers, distributors, retailers, consumers, and national governments from economic (price), health (allergens), and religious reasons. Flavour of several food products is one of the key attributes of their quality and authenticity. In the case of some foods, the aroma of a product is specific enough to discriminate an original product from its fraud or adulterated counterpart. Electronic nose (e-nose) is a rapid and powerful technique, which requires no special sample preparation to determine the aroma of a product. In the present review, the applications of different e-noses and chemometrics for determination of food authenticity including adulteration and confirmation of origin are discussed. E-noses of various configurations are a very promising tool for testing the authenticity of food products.

The synthesis of metal oxide nanoparticles with the use of plant extract is a promising alternative to traditional chemical methods. The aim of this work was to fabricate MgO nanoparticles using the Artemisia abrotanum herb water extract. The biologically synthesized MgO nanoparticles were characterized by UV–Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDS profile and transmission electron microscopy (TEM). XRD studies confirmed that pure monoclinic crystallite structures of MgO nanoparticles were formed. The average size of MgO nanoparticles was found to be 10 nm. EDS profile confirmed the signal characteristic of magnesium and oxygen. FTIR analysis confirmed the presence of active compounds responsible for the stabilization of MgO nanoparticles. The synthesized nanoparticles showed good catalytic activity in the reduction of methyl orange (MO). MgO nanoparticles also exhibit very good antioxidant properties.

1. Possible applications of metal nanoparticles in antimicrobial food packaging Renata Dobrucka, Magdalena Ankiel Journal of Food Safety CrossRef

The aim of this paper is to discuss the role and impact of generative artificial intelligence (AI) systems in higher education. The proliferation of AI models such as GPT-4, Open Assistant and DALL-E presents a paradigm shift in information acquisition and learning. This transformation poses substantial challenges for traditional teaching approaches and the role of educators. The paper explores the advantages and potential threats of using generative AI in education and necessary changes in curricula. It further discusses the need to foster digital literacy and the ethical use of AI. The paper’s findings are based on a survey conducted among university students exploring their usage and perception of these AI systems. Finally, recommendations for the use of AI in higher education are offered, which emphasize the need to harness AI's potential while mitigating its risks. This discourse aims at stimulating policy and strategy development to ensure relevant and effective education in the rapidly evolving digital landscape.