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We describe herein the significance of a sodium citrate and tannic acid mixture in the synthesis of spherical silver nanoparticles (AgNPs). Monodisperse AgNPs were synthesized via reduction of silver nitrate using a mixture of two chemical agents: sodium citrate and tannic acid. The shape, size and size distribution of silver particles were determined by UV–Vis spectroscopy, dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM). Special attention is given to understanding and experimentally confirming the exact role of the reagents (sodium citrate and tannic acid present in the reaction mixture) in AgNP synthesis. The oxidation and reduction potentials of silver, tannic acid and sodium citrate in their mixtures were determined using cyclic voltammetry. Possible structures of tannic acid and its adducts with citric acid were investigated in aqueous solution by performing computer simulations in conjunction with the semi-empirical PM7 method. The lowest energy structures found from the preliminary conformational search are shown, and the strength of the interaction between the two molecules was calculated. The compounds present on the surface of the AgNPs were identified using FT-IR spectroscopy, and the results are compared with the IR spectrum of tannic acid theoretically calculated using PM6 and PM7 methods. The obtained results clearly indicate that the combined use of sodium citrate and tannic acid produces monodisperse spherical AgNPs, as it allows control of the nucleation, growth and stabilization of the synthesis process. Graphical abstract ᅟ

The cultural transferability and relevance of work performance constructs across various cultures remain crucial for global human resources research. This paper investigates the cultural adaptation of the Work Role Performance Questionnaire (WRPQ) for the Polish work environment. Originating from the work role theory, WRPQ encapsulates nine distinct work roles derived from two dimensions: behavior type (proficiency, adaptivity, proactivity) and exhibition level (individual, team, organization). We proposed two hypothesis series addressing the questionnaire’s structure and differential predictions by various work-related traits and attitudes. A multidisciplinary team proficiently translated the questionnaire, which was then tested in a pilot study (n = 276) followed by two primary studies involving supervisors (n = 698) and employees (n = 534). The analytical approach integrated confirmatory factor analysis, path analysis, and psychometric evaluations. The findings reinforce the questionnaire’s reliability within the Polish cultural context, validate its nine subdimension structure, and elucidate distinct relations with predictors. The successful cultural adaptation of the WRPQ showcases the potential for broader applications in diverse cultural settings, underscoring the importance of context-specific measurement tools in work performance and human resources research.

This study investigates the impact of social media-related microbreaks on the resource recovery of employees. Specifically, we examined whether or not the brief, hedonic use of social media through algorithmic videos could fully replenish resources, such as vigor and fatigue, that are depleted after performing clerical tasks. We also compared this form of recovery to other established microbreak activities. We used a pre-registered, mixed-method experimental design to collect data from 308 employees. A series of mixed-method ANOVA tests complemented by quadratic linear contrast terms and post-hoc analyses were performed to test hypotheses and address research questions. The findings indicate that although social media microbreaks offer a certain degree of resource replenishment, they do not provide full recovery, particularly regarding fatigue. Social media facilitate a reasonable psychological detachment but fall short in other recovery experiences. Notably, exposure to nature yielded more beneficial results. The study contributes novel insights to a field primarily focused on the negative impacts of excessive social media use and suggests that rational and brief usage can be advantageous for employee well-being.

The interaction between silver nanoparticles and herpesviruses is attracting great interest due to their antiviral activity and possibility to use as microbicides for oral and anogenital herpes. In this work, we demonstrate that tannic acid modified silver nanoparticles sized 13 nm, 33 nm and 46 nm are capable of reducing HSV-2 infectivity both in vitro and in vivo. The antiviral activity of tannic acid modified silver nanoparticles was size-related, required direct interaction and blocked virus attachment, penetration and further spread. All tested tannic acid modified silver nanoparticles reduced both infection and inflammatory reaction in the mouse model of HSV-2 infection when used at infection or for a post-infection treatment. Smaller-sized nanoparticles induced production of cytokines and chemokines important for anti-viral response. The corresponding control buffers with tannic acid showed inferior antiviral effects in vitro and were ineffective in blocking in vivo infection. Our results show that tannic acid modified silver nanoparticles are good candidates for microbicides used in treatment of herpesvirus infections.

Dynamic light scattering is a method that depends on the interaction of light with particles. This method can be used for measurements of narrow particle size distributions especially in the range of 2–500 nm. Sample polydispersity can distort the results, and we could not see the real populations of particles because big particles presented in the sample can screen smaller ones. Although the theory and mathematical basics of DLS technique are already well known, little has been done to determine its limits experimentally. The size and size distribution of artificially prepared polydisperse silver nanoparticles (NPs) colloids were studied using dynamic light scattering (DLS) and ultraviolet-visible (UV-Vis) spectroscopy. Polydisperse colloids were prepared based on the mixture of chemically synthesized monodisperse colloids well characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), DLS, and UV-Vis spectroscopy. Analysis of the DLS results obtained for polydisperse colloids reveals that several percent of the volume content of bigger NPs could screen completely the presence of smaller ones. The presented results could be extremely important from nanoparticles metrology point of view and should help to understand experimental data especially for the one who works with DLS and/or UV-Vis only.

Human catalase cDNA was cloned into a pEX-C-His vector. Purified recombinant catalase was immobilized on nanoparticles. Gold and silver nanoparticles were synthesized in a variety of sizes by chemical reduction; no agglomerates or aggregates were observed in any of the colloids during dynamic light scattering or scanning transmission electron microscopy analysis. After immobilization on gold nanoparticles, recombinant catalase activity was found to be lower than that of the same amount of enzyme in aqueous solution. However, after 10 days of storage at room temperature, the activity of catalase immobilized on gold nanoparticles (AuNPs) of 13 and 20 nm and coverage of 133% was 68 and 83% greater than catalase in aqueous solution, respectively. During 10 days of experiment, percentage activity of catalase immobilized on those gold nanoparticles was higher in comparison to CAT in aqueous solution. Catalase immobilized on silver nanoparticles did not lose activity as significantly as catalase immobilized on AuNPs. Those results confirm the ability to produce recombinant human enzymes in a bacterial expression system and its potential use while immobilized on silver or gold nanoparticles.

We made comparison of titanium dioxide powders obtained from three syntheses including sol-gel and precipitation methods as well as using layered (tetramethyl)ammonium titanate as a source of TiO2. The obtained precursors were subjected to step annealing at elevated temperatures to transform into rutile form. The transformation was determined by Raman measurements in each case. The resulting products were characterised using Raman spectroscopy and dynamic light scattering. The main goal of the studies performed was to compare the temperature of the transformation in three titania precursors obtained by different methods of soft chemistry routes and to evaluate dielectric properties of rutile products by means of broadband dielectric spectroscopy. Different factors affecting the electrical properties of calcinated products were discussed. It was found that sol-gel synthesis provided rutile form after annealing at 850°C with the smallest particles size about 20 nm, the highest value of dielectric permittivity equal to 63.7, and loss tangent equal to 0.051 at MHz frequencies. The other powders transformed to rutile at higher temperature, that is, 900°C, exhibit lower value of dielectric permittivity and had a higher value of particles size. The correlation between the anatase-rutile transformation temperature and the size of annealed particles was proposed.

(1) Background: An essential task for public health and industrial and organizational psychology specialists is maintaining employees’ workplace well-being. This has become more difficult with pandemic-induced changes (i.e., the shift to remote work and the rise of hybrid teams). This research adopts a team perspective to explore the issue of workplace well-being drivers. It is hypothesized that the team type (co-located, hybrid, or virtual) should be recognized as a unique environmental factor, resulting in the need for different resources for members of these teams to maintain their well-being. (2) Methods: A correlational study was conducted to systematically compare the relationship (its significance and importance) of a wide range of demands and resources with the comprehensively measured workplace well-being of members of co-located, hybrid, and virtual teams. (3) Results: The results confirmed the hypothesis. The significant drivers of well-being in each team type were different, and the ranking of the most important drivers within each team type varied. (4) Conclusions: Team type should be considered a unique environmental factor, even for individuals from different job families and organizations. This factor should be considered in practice and research employing the Job Demand–Resources model.

In this paper, we discuss the influence of the ligand type present on the surface of silver nanoparticles (AgNPs) on its affinity to the virus surface and its virucidal activity against herpes simplex virus type 2 (HSV-2). We selected four different ligands, which potentially exhibit different affinity to the HSV-2 virus surface and used them for functionalization of AgNPs: i) sodium citrate: ii) tannic acid; iii) 1-mercaptoundecane-1-sulfonate (MUS); iv) and poly(ethylene glycol) (PEG). The antiviral activity was performed by in vitro Vero cell culture. Anti- inflammatory activity was performed by measurement of NF-κB activity. The antiviral potential of functional NPs in vivo was tested with HSV-2 model of genital infection. Cryo- transmission electron microscopy (cryo-TEM) was used to directly visualize the interactions or lack of interactions of functional NPs with the surface of the HSV-2 virus and to assess their affinity for the virus surface. It was found that the surface chemistry of NPs plays a key role in modulation of its interaction with the HSV-2 virus. Two of the selected ligands (sodium citrate and PEG) were inert and show no affinity to the virus surface. AgNPs functionalized with heparan sulfate-mimic ligand (MUS) showed high affinity to the virus surface, and the appearance of these interactions resulted in virus deactivation in about 50%. In the case of silver nanoparticles functionalized with tannic acid, the assessment of the affinity is difficult to be resolved, mainly because TA-AgNPs exhibit very strong virucidal effect (~100%) and immediately after the contact of the HSV-2 virus with those NPs the virus structure is being destroyed. The obtained results indicate that the high affinity of functional nanoparticles to the virus surface does not provide the high virucidal effectiveness. The most effective revealed to be TA-AgNPs which exhibit very strong virucidal effect against HSV-2 virus.

(1) Background: Epigallocatechin gallate (EGCG) has been recognized as a flavonoid showing antiviral activity against various types of DNA and RNA viruses. In this work, we tested if EGCG-modified silver nanoparticles (EGCG-AgNPs) can become novel microbicides with additional adjuvant properties to treat herpes infections. (2) Methods: The anti-HSV and cytotoxic activities of EGCG-AgNPs were tested in human HaCaT and VK-2-E6/E7 keratinocytes. HSV-1/2 titers and immune responses after treatment with EGCG-AgNPs were tested in murine models of intranasal HSV-1 infection and genital HSV-2 infection. (3) Results: EGCG-AgNPs inhibited attachment and entry of HSV-1 and HSV-2 in human HaCaT and VK-2-E6/E7 keratinocytes much better than EGCG at the same concentration. Infected mice treated intranasally (HSV-1) or intravaginally (HSV-2) with EGCG-AgNPs showed lower virus titers in comparison to treatment with EGCG alone. After EGCG-AgNPs treatment, mucosal tissues showed a significant infiltration in dendritic cells and monocytes in comparison to NaCl-treated group, followed by significantly better infiltration of CD8+ T cells, NK cells and increased expression of IFN-α, IFN-γ, CXCL9 and CXCL10. (4) Conclusions: Our findings show that EGCG-AgNPs can become an effective novel antiviral microbicide with adjuvant properties to be applied upon the mucosal tissues.