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Nanoemulsion technique based on Ouzo effect was applied for the fast and simple synthesis of Ag3PO4 at room temperature. X-ray powder diffraction analysis and Raman spectroscopy reviled that synthesized powder was single-phase. Using scanning electron microscopy analysis, it was found that the synthesized Ag3PO4 particles were near-spherical shape with an average diameter of 100 nm. The high value for the specific surface area of obtained powder was measured by Brunauer–Emmet–Teller method. Finally, the Ag3PO4 product was used as a photocatalyst for the photodegradation of crystal violet dye in an aqueous solution. Nanoemulsion strategy procedure provides a simple pathway to obtain a highly efficient single-phase Ag3PO4 photocatalyst.

New binary catalytic systems based on sulphated zirconia-alumina were synthesized by controlled hydrolysis of alkoxides using relative molar ratios of constituents 1:1, 1:2 and 1:3 in favour of zirconia. The obtained differences in the final catalytic material’s properties may be related to organic precursor memory effect, the applied calcinations temperatures and used alumina contents. The addition of alumina to zirconia affected the structural and surface properties stabilizing bare zirconia by means of slower phase transformation of tetragonal zirconia crystal phase into monoclinic one, further resulting in smaller crystallites sizes and higher surface density of acidic function (sulphates). The best alumina impact on physico-chemical properties was achieved when the highest amount of alumina (e.g. 50%) and lower calcination temperature (500°C) were used, causing relatively high steady-state activity in isomerization of n-hexane at reaction temperature 250 °C. On the other hand, higher calcination temperature (600 °C) played a role in the genesis of greater sulphate density. Catalytic activity and selectivity are expressed as a complex synergistic function of relative density of acid sites together with positive status of other optimized physico-chemical properties of the catalytic material (by activation and calcination temperatures).

This paper reports the preparation and electrochemical study of new glassy carbon electrode (GCE) bulk-modified with synthesized hybrid materials: Pt and MoO2 nanoparticles deposited on the multi-walled carbon nanotubes (MWCNTs). The results of electrochemical study of commercial GCE and electrodes modified with Pt–MWCNT and MoO2–MWCNT were obtained by cyclic voltammetry in K4Fe(CN)6 and NaOH solutions. Morphology and structure of the synthesized hybrid materials were analysed using the method of high resolution transmission electron microscopy, indicating the presence of well dispersed nanoparticles of Pt and MoO2 over MWCNT network. The results of the electrochemical study show that the capacitance of electrode modified with MoO2–MWCNT and Pt–MWCNT is 62–65 times higher than the capacitance of the commercial GCE. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 451-03-68/2020-14/200124]

Spider silk fibers, collected from Pholcus Phalangioides spider were used as a template for obtaining magnesium oxide (MgO, periclase) as well as magnesium hydroxide (Mg(OH)2, brucite) fibers. Magnesium oxide fibers were obtained in a simple manner by heat induced decomposition of magnesium salt (MgCl2) in the presence of the spider silk fibers, while magnesium hydroxide fibers were synthesized by hydration of MgO fibers at 50, 70 and 90 C, for 48 and 96 h. According to Scanning electron microscopy (SEM), dimensions of spider silk fibers determined the dimension of synthesized MgO fibers, while for Mg(OH)2 fibers, the average diameter was increased with prolonging the hydration period. The surface of Mg(OH)2 fibers was noticed to be covered with brucite in a form of plates. X-Ray diffraction (XRD) analysis showed that MgO fibers were single-phased (the pure magnesium oxide fibers were obtained), while Mg(OH)2 fibers were two- or single-phased brucite depending on incubation period, and/or incubation temperature. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 45012]

A new, simple, rapid, sensitive and selective kinetic spectrophotometric method for Pd(II) traces determination was elaborated in this paper. It is based on the catalytic effect of palladium ions upon the oxidation of methylene blue B (MBB) by (NH4)2S2O8 (APS) in citric buffer (BUF) solution. At the working temperature of 25 C and the wavelength of 662.4 nm, the optimal conditions for palladium determination were found. RSD value was found to be 2.6 to 4.9% for the investigated concentration range of Pd(II). Limit of detection (LD) was found to be 2.0 ng cm–3 Pd(II), and limit of quantification (LQ) is 6.9 ng cm–3 Pd(II). Only the presence of Pb2+, Hg2+ and Sn2+ in the reaction mixture interferes the determination of palladium by this method, while Au3+ and Ag+ have the catalytic effect upon the reaction rate. By this method, it is possible to determine the Pd(II) traces in the concentration range of 3.3x10–8 to 1.0x10–6 g cm–3. The method was confirmed by determination of Pd(II) traces in alloy PtRhG as well as in the powder of Pt. The obtained results were compared to those obtained by ICP-OES method and good agreement of results was found. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172051]

Titania based catalyst and TiO2 doped with zirconia were prepared by modified sol–gel method. The synthesized catalysts samples were characterized by BET, XRD, SEM and FTIR techniques. Photocatalytic activity was tested in the reaction of crystal violet (CV) dye decolorization/decomposition under UV light irradiation. The effect of several operational parameters, such as catalyst dosage, initial dye concentrations, duration of UV irradiation treatment and number of reaction cycles were also considered. The obtained results indicated faster dye decolorization with the increase of the catalyst amount and a decrease of initial CV concentrations. An influence of doping with zirconia on the physico-chemical properties of bare titania was studied. The doping procedure had affected photocatalytic properties of the final catalytic material, and had improved photocatalytic performances of doped catalyst on crystal violet decolorization/degradation in comparison to bare titania. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 1612008, Grant no. 45012 and Grant no. 172061]

Heterogeneous catalysis is in recent focus of research for biodiesel production from vegetable oils because of advantages such as easy separation and reuse of catalysts, although homogeneous catalysis is most commonly used method. The aim of this study was preparation of γ-Al2O3 support by modified sol-gel procedure, synthesis of the KI/Al2O3 catalyst and testing its activity in the transesterification of sunflower oil with methanol. Influences of different process parameters on conversion of sunflower oil to methyl esters were examined. The gained results implicate that the potassium iodide incorporation into/onto the structure of γ-Al2O3 significantly influences textural and structural properties of the catalyst. Additionally, the catalyst basic strength is increased and all together those properties are positively affecting the activity of the catalyst in the reaction of transesterification of sunflower oil with methanol. The impregnation of alumina with potassium iodide resulted in the additional formation of basic catalytically active sites. The surface properties of the catalyst have an essential impact on its catalytic performance. Under relatively mild process conditions and relatively short reaction time, the usage of the KI/Al2O3 catalyst resulted in very high conversion to fatty acids methyl esters (i.e. 99.99 %). [Projekat Ministarstva nauke Republike Srbije, br. 172061 i br. TR 34008]

The influence of the physicochemical properties of a series of CaO catalysts activated at different temperatures on the biodiesel production was investigated. These catalysts show dissimilar yields in the transesterification of triglycerides with methanol. We have found significant relationships between structural properties (the type of the pore system, the typical CaO crystal phase and the sizes of crystallites (up to 25 nm), the minimal weight percentage of CaO phase, the total surface basicity and potential existence of two types of basic active sites) of CaO prepared and activated by means of thermal treatment at highest temperature and catalytic efficiency. Benefits of this catalyst are short contact time, standard operating temperature and atmospheric conditions, relatively low molar ratios and small catalyst loading. These all together resulted in a very high biodiesel yield of high purity. The properties of different biodiesel (obtained with the use of the prepared CaO catalyst) blends with different diesel and biodiesel ratios indicate that the higher the fraction of biodiesel fuel the better the achieved fuel properties according to the EU standards. A significant reduction of CO2 and CO emissions and only a negligible NOx increase occurred when blends with an increased biodiesel portion was used. The use of biodiesel derived blends, and the eventual complete replacement of fossil fuels with biodiesel as a renewable, alternative fuel for diesel engines, would greatly contribute to the reduction of greenhouse gases emissions. [Projekat Ministarstva nauke Republike Srbije, br. ON 172061 i TR 34008]

Resorcinol-formaldehyde carbon cryogel has been prepared, characterized and used for the removal of commonly used herbicide clopyralid from the aqueous solutions under varying experimental conditions. Carbon has shown a relatively high specific surface area, significant mesoporosity and an amorphous structure. A set of the following isotherm models has been used to interpret the equilibrium data: Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Jovanović, Hurkins-Jura, and Helsey model. Several models have fitted well although the calculated values for qmax poorly correlate with the data obtained experimentally. The kinetic models of the pseudo-first and pseudo-second-order, the models of Elovich, Bangham and the intraparticle diffusion model have been used for fitting the kinetic data. The rate of the process is fast in the beginning while adsorption equilibrium is attained not until 24 hours. Adsorption was found to be pH dependent and favored in acidic solutions.

This paper deals with synchronised influences of hydromechanical and hidrochemical parameters on the formation of solid deposits in geothermal and other waters which compose complex heterogeneous and micro-heterogeneous system of liquid-solid. Constituents of these waters in ionic, colloidal and micro-heterogeneous suspended state of liquid-solid are responsible for the creation of the carbonates, sulphates and other solid matters. In these processes one cannot eliminate the influence of hydromechanical parameters with flow velocity and water flow criteria (laminar or turbulent flow) as vital factors. Experiments were conducted on the laboratory pilot installation with glass pipes diameter of 2, 4, 6, 8 and 10 mm respectively, and the flow was monitored by means of digital peristaltic pump with the flow rate of 2 ml/min to 5000 ml/min. The paper gives the results of the investigation of the impact of the linear flow velocity on the relative decrease of the initial water hardness in geothermal waters of Sijarinska Banja spa, Niška Banja spa and the estuary water of Medijana, Niš. From the obtained dependences, according to the linear regression model, for each diameter critical values for linear velocities as an important parameter for the understanding of the synergism of the hydromechanical and hydrochemical parameters were determined. [Projekat Ministarstva nauke Republike Srbije, br. 33046]

The quality of some medicinal plants and their water extracts from South East Serbia is determined on the basis of metal content using atomic absorption spectrometry. The two methods were used for the preparation of water extracts, to examine the impact of the preparation on the content of metals in them. Content of investigated metals in both water extracts is markedly lower then in medicinal plants, but were higher in water extract prepared by method (I), with exception of lead content. The coefficients of extraction for the observed metal can be represented in the following order: Zn > Mn > Pb > Cu > Fe. Correlation coefficients between the metal concentration in the extract and total metal content in plant material vary in the range from 0.6369 to 0.9956. This indicates need the plants to be collected and grown in the unpolluted area and to examine the metal content. The content of heavy metals in the investigated medicinal plants and their water extracts is below the maximum allowable values, so they are safe to use.

This paper presents a complete characterization of rapeseed oil, of Banaćanka variety, as well as the potential use of oil generated after filtering, in order to obtain biodiesel. Researches are based on the fact that Banaćanka is the oldest domestic rapeseed variety, the so-called double zero "00" (low in erucic acid, below 5%, and glucosinolates below than 30 mmol g-1), suitable for use in the region, since it is low temperatures tolerant, posseses high genetic potential for seed yield of about 5.2 t/ha, and high oil content of around 45%. Transesterification was carried out in batch reactor Parr 4520, with KOH as a catalyst. Cold pressed oil without prior treatment was used as feedstock for transesterificataion. The paper analyses the effects of temperature, reaction duration, catalyst amount and rate of agitation on the synthesis of biodiesel at constant pressure and molar methanol/oil ratio.[Projekat Ministarstva nauke Republike Srbije, br. TR-31046: Improvement of the quality of tractors and mobile systems with the aim of increasing competitiveness and preserving soil and environment]

Two series of zirconia based catalysts promoted with either sulfates or phosphates were prepared, calcined at different temperatures (600 and 700°C) and evaluated for the n-hexane isomerization reaction. The catalysts with different concentrations of sulfates or phosphates (4 or 10 wt. %) were characterized by BET, XRD, SEM methods, and total acidity was evaluated by using the Hammett indicators. Their final catalytic performances were correlated with their physical-chemical properties (surface, structural, textural and morphological). It was found that sulfated zirconia catalyst calcined at lower temperature showed the highest initial activity of all tested catalysts as the result of favorable total acidity, mesopore texture and structural properties. Somewhat lower activity of the sulfated catalyst calcined at higher temperature is related to the content of acid groups partially removed during thermal treatment, thus, lower total acidity, and also to less favorable textural and structural features. Negligible activity of phosphated zirconia catalysts is connected with low total acidity despite the positive status of particular property showing the complexity of the active phase/site formation in the catalyst.

Adsorption of a cationic phenothyazine dye methylene blueonto activated carbon prepared from pine cones was investigated with the variation in parameters of contact time, dye concentration and pH. The kinetic data were found to follow the pseudo-second-order kinetic modelclosely. The equilibrium data were best represented by the Langmuir isotherm with maximum adsorption capacity of 233.1 mg g-1. Adsorption was favored by using a higher solution pH. Textural analysis by nitrogen adsorption was used to determine specific surface area and pore structure of the obtained carbon. Boehm titrations revealed that carboxylic groups are present in the highest degree on the carbon surface. The results indicate that the presented method for activation of pine cones could yield activated carbon with significant porosity, developed surface reactivity and considerable adsorption affinity toward cationic dye methylene blue.

Bentonite is mainly composed of clay minerals from smectite group, therefore it has a well developed and chemically active surface area and high cation exchange capacity. Moreover, an interlayer space of smectite has unusual hydration properties, which manifest as swelling of bentonite in water. These properties make bentonite as a commonly used raw material in chemistry and industry, and it is very important in environmental protection and water treatment as an effective sorbent of heavy metals. The results of X-ray diffraction, a cationic exchange capacity, specific surface area, acid-base properties of the surface and the swelling index showed that the bentonite sample contains mostly montmorillonite. The aim of this study was to test the efficacy of bentonite in the removal of Mn2+ from aqueous systems. The experimental results of Mn2+ adsorption on the bentonite were interpreted by Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherms. The adsorption isotherm studies indicate that the adsorption of Mn2+ follows Langmuir isotherm very well. Theoretical monolayer saturation capacity according to Langmuir model was 12.41 mg/g. The removal of Mn2+ is achieved by ion exchange mechanism with naturally occurring cations in bentonite, as well as by forming the inner- and outer-sphere complexes with bentonite surface.

Cones of the European Black pine and Horse chestnut kernel, regarded as brown municipal waste, was utilized in this work as a precursor for powdered activated carbons. Chemical activation was employed at 500°C in inert atmosphere of nitrogen. Standard physico-chemical analyses were performed to examine obtained products. FTIR method was employed to determine fuctional groups which were found to be typical for activated carbons. Acidic oxygen groups were quantitatively determined using Boehm titrations. It was established that carboxylic groups on pine cone activated carbon, and phenolic groups on chestnut kernel activated carbon were dominant from all acidic oxygen groups. Since both contact pH and pHPZC were determined to be fairly acidic, it could be concluded that obtained activated carbons belong to L-type. Shape and layout of micrometer dimensioned particles were observed by scanning electron microscopy. Particles of different shapes and dimensions along with small cracks and wide crevices and voids were noticed. Textural analysis was used to determine specific surface area and pore distribution of obtained activated carbons. Obtained products possess highly developed surface area and wide pore distribution.

The heavy metals (Fe, Cu, Zn and Mn) contents of selected plant species, grown in Southeast region of Serbia, that are traditionally used in alternative medicine were determined. Among the considered metals, iron content was the highest one and varied from 137.53 up to 423.32 mg/kg, while the contents of Cu, Zn and Mn were remarkably lower, and ranged from 8.91 to 62.20 mg/kg. In addition, an analysis of plants extracts showed a significant transfer of heavy metals during extraction procedure; therefore, the corresponding extraction coefficients reached values up to 88.8%. Those were especially high in the ethanol based extracts. Moreover, it is established that such coefficients mostly depend on the solvent nature and also on the treated plant species. The obtained results impose that medicinal plants from Southeast region of Serbia due to rather low content of heavy metals are appropriate for preparation of teas and medicinal extracts.

Using sulfuric acid as the sulfating agent, two catalyst series were obtained from hydroxide and nitrate precursor with a sulfate loading identical to commercial sulfated hydroxide, i.e., 4.2 mass%. After calcination at 500, 600 and 700°C, all nine samples had various contents of residual sulfates depending on the origin of the catalyst. Accordingly, their surface properties were different, which, together with various textural properties, govern the formation of the active phase and their catalytic activity in the n-hexane isomerization reaction. The dominant activity and yield of mainly mono-branched isomers were attained in reaction at 200°C with a commercially sulfated zirconia catalyst calcined at 500°C. Among the SZ catalyst series synthesized from hydroxide and nitrate, the second according to its activity profile was similar to that of the commercially sulfated one, while samples originating from hydroxide showed some activity only after calcination at 600°C. This is due to the poorer textural properties of the hydroxide series, necessitating a higher calcination temperature in order to promote the simultaneous decomposition of S-containing species and their re-adsorption into the zirconia matrix following interaction and active phase formation. It seems that the tetragonal zirconia phase was not responsible for the catalytic activity but a synergistic effect of the textural properties of the samples and the sulfate loadings, which determine different acid strengths on the catalyst surface.

Two series of sulfated zirconia catalysts were synthesized from various precursors using mono- or multi-step sequence preparations under laboratory conditions. Their activities/selectivities in the isomerization reaction of n-hexane were correlated to their textural, structural and morphological properties. The slightly higher activity of a commercially sulfated Zr(OH)4-based catalyst is in agreement with the differences in the content of SO24 - ions and their thermal stability, textural and structural properties, i.e., crystallite size and possible imperfection of the incorporation of sulfate groups in the multi-step synthesis of the catalyst having a nitrate origin. The employment of H2 as the carrier gas resulted in no catalytic activity, regardless of the catalyst precursor, preparation method and calcination temperature. When the isomerization reaction was performed under He, the relatively short life-times of all catalyst samples were caused by fast deactivation due to coking in the absence of H2. .

Zirconium-hydroxide precursor samples are synthesized from Zr-hydroxide, Zr-nitrate, and Zr-alkoxide, by precipitation/impregnation, as well as by a modified sol-gel method. Precursor samples are further sulphated for the intended SO4 2- content of 4 wt.%, and calcined at 500-700oC. Differences in precursors’ origin and calcination temperature induce the incorporation of SO4 2- groups into ZrO2 matrices by various mechanisms. As a result, different amounts of residual sulphates are coupled with other structural, as well as surface properties, resulting in various catalytic activities of sulphated zirconia samples. Catalyst activity and selectivity are a complex synergistic function of tetragonal phase fraction, sulphates contents, textural and surface characteristics. Superior activity of SZ of alkoxide origin can be explained by a beneficial effect of meso-pores owing to a better accommodation of coke deposits.

The subject of research in the paper will be the right of foreign citizens to inherit real estate and agricultural land in the Republic of Serbia. By using the methodologicaltheoretical framework, the aim of the work will be the analysis of the inheritance institute, which represents the basis of acquisition of property rights on real estate and agricultural land by foreign citizens. The era of globalization favors the movement of people between countries, but each country determines the availability and scope of rights of foreign nationals according to its interests. Therefore, in order to analyze the research subject, we will use historical, descriptive, normative and content analysis methods. The conclusion will summarize the results of research on inheritance as a basis for acquiring property rights on real estate and agricultural land by foreign citizens.rights over real estate and agricultural land by foreign citizens.

Abstract The first approved vaccines for human use against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) are nanotechnology‐based. Although they are modular, rapidly produced, and can reduce disease severity, the currently available vaccines are restricted in preventing infection, stressing the global demand for novel preventive vaccine technologies. Bearing this in mind, we set out to develop a flexible nanovaccine platform for nasal administration to induce mucosal immunity, which is fundamental for optimal protection against respiratory virus infection. The next‐generation multiepitope nanovaccines co‐deliver immunogenic peptides, selected by an immunoinformatic workflow, along with adjuvants and regulators of the PD‐L1 expression. As a case study, we focused on SARS‐CoV‐2 peptides as relevant antigens to validate the approach. This platform can evoke both local and systemic cellular‐ and humoral‐specific responses against SARS‐CoV‐2. This led to the secretion of immunoglobulin A (IgA), capable of neutralizing SARS‐CoV‐2, including variants of concern, following a heterologous immunization strategy. Considering the limitations of the required cold chain distribution for current nanotechnology‐based vaccines, it is shown that the lyophilized nanovaccine is stable for long‐term at room temperature and retains its in vivo efficacy upon reconstitution. This makes it particularly relevant for developing countries and offers a modular system adaptable to future viral threats.

The study of hydrogen peroxide reduction in an alkaline aqueous medium on a composite of palladium particles dispersed in an amorphous carbon matrix (Pd@AC) was performed. Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), and X-ray Powder Diffraction (XRD) were used to examine morphology, composition, and crystalline structure. The crystalline structure and size of palladium were analyzed using XRD. The reduction of hydrogen peroxide was studied through cyclic and square-wave voltammetry in an alkaline solution in the absence and presence of dissolved oxygen. The overall electrocatalytic effect of Pd@AC toward hydrogen peroxide reduction strongly depends on the presence of oxygen and the hydrogen peroxide disproportionation reaction in the three-phase system of amorphous carbon, palladium particles, and electrolyte solution.

Nutrition is considered the primary paragenetic factor influencing the milk urea (MU) concentration in ruminants. In addition to diet, various other factors (including season, milk yield, stage of lactation, etc.) have also been shown to affect the urea concentration in ruminant milk. While the physiological concentration of MU has been well-defined for cow's milk, with an optimal range of 15 to 30 mg/dl, such parameters have yet to be established for goat's milk. The objective of this study was to determine the urea concentration in the milk of Alpine goats and to assess its correlation with the daily milk yield and the contents of fat, protein, lactose, and solids-not-fat (SNF). A total of 3,009 samples of Alpine goat milk, collected from two farms in 2021, were analyzed. The average MU concentration was 37.3 ± 8.9 mg/dl, with a range from 13.8 to 110.7 mg/dl. The average daily milk yield was 1.15 ± 0.49 kg, whereas the average milk fat and protein contents were 3.28 ± 0.97% and 3.35 ± 0.50%, respectively. The study found a positive and statistically significant correlation between the MU concentration and the contents of milk fat, protein, and SNF. Conversely, an increase in the MU concentration was negatively correlated with the daily milk yield. Monitoring the MU concentration in dairy goat herds enables the optimization of feed rations, particularly their protein and energy contents, thus improving nitrogen utilization in milk production. [ABSTRACT FROM AUTHOR]

Studying the interaction of inorganic systems with organic ones is a highly important avenue for finding new drugs and treatment methods. Tumor cells show an increased demand for amino acids due to their rapid proliferation; thus, targeting their metabolism is becoming a potential oncological therapeutic strategy. One of the inorganic materials that show antitumor properties is titanium dioxide, while its doping was found to enhance interactions with biological systems. Thus, in this study, we investigated the energy landscape of glutamine (L), an amino acid, on pristine and doped TiO2 surfaces. We first locally optimized 2D-slab structures of pristine and Au/Ag/Cu-doped anatase (001 and 101 surfaces) and similarly optimized a single molecule of glutamine in vacuum. Next, we placed the pre-optimized glutamine molecule in various orientations and on a variety of locations onto the relaxed substrate surfaces (in vacuum) and performed ab initio relaxations of the molecule on the substrate slabs. We employed the DFT method with a GGA-PBE functional implemented in the Quantum Espresso code. Comparisons of the optimized conformations and electronic structures of the amino acid in vacuum and on the surfaces yield useful insights into various biological processes.

The first approved vaccines for human use against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) are nanotechnology‐based. Although they are modular, rapidly produced, and can reduce disease severity, the currently available vaccines are restricted in preventing infection, stressing the global demand for novel preventive vaccine technologies. Bearing this in mind, we set out to develop a flexible nanovaccine platform for nasal administration to induce mucosal immunity, which is fundamental for optimal protection against respiratory virus infection. The next‐generation multiepitope nanovaccines co‐deliver immunogenic peptides, selected by an immunoinformatic workflow, along with adjuvants and regulators of the PD‐L1 expression. As a case study, we focused on SARS‐CoV‐2 peptides as relevant antigens to validate the approach. This platform can evoke both local and systemic cellular‐ and humoral‐specific responses against SARS‐CoV‐2. This led to the secretion of immunoglobulin A (IgA), capable of neutralizing SARS‐CoV‐2, including variants of concern, following a heterologous immunization strategy. Considering the limitations of the required cold chain distribution for current nanotechnology‐based vaccines, it is shown that the lyophilized nanovaccine is stable for long‐term at room temperature and retains its in vivo efficacy upon reconstitution. This makes it particularly relevant for developing countries and offers a modular system adaptable to future viral threats. [ABSTRACT FROM AUTHOR]

The subject of research in the paper will be the right of foreign citizens to inherit real estate and agricultural land in the Republic of Serbia. By using the methodological-theoretical framework, the aim of the work will be the analysis of the inheritance institute, which represents the basis of acquisition of property rights on real estate and agricultural land by foreign citizens. The era of globalization favors the movement of people between countries, but each country determines the availability and scope of rights of foreign nationals according to its interests. Therefore, in order to analyze the research subject, we will use historical, descriptive, normative and content analysis methods. The conclusion will summarize the results of research on inheritance as a basis for acquiring property rights on real estate and agricultural land by foreign citizens.rights over real estate and agricultural land by foreign citizens. [ABSTRACT FROM AUTHOR]

The antibacterial performance and cytotoxic examination of in situ prepared silver nanoparticles (Ag NPs), on inorganic-organic hybrid nanopowder consisting of zirconium dioxide nanoparticles (ZrO2 NPs) and dihydroquercetin (DHQ), was performed against Gram (−) bacteria Escherichia coli and Gram (+) bacteria Staphylococcus aureus, as well as against human cervical cancer cells HeLa and healthy MRC-5 human cells. The surface modification of ZrO2 NPs, synthesized by the sol-gel method, with DHQ leads to the interfacial charge transfer (ICT) complex formation indicated by the appearance of absorption in the visible spectral range. The prepared samples were thoroughly characterized (TEM, XRD, reflection spectroscopy), and, in addition, the spectroscopic observations are supported by the density functional theory (DFT) calculations using a cluster model. The concentration- and time-dependent antibacterial tests indicated a complete reduction of bacterial species, E. coli and S. aureus, for all investigated concentrations of silver (0.10, 0.25, and 0.50 mg/mL) after 24 h of contact. On the other side, the functionalized ZrO2 NPs with DHQ, before and after deposition of Ag NPs, do not display a significant decrease in the viability of HeLa MRC-5 cells in any of the used concentrations compared to the control.

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The Cr−Si−N system is of great interest for materials with advanced tribological and mechanical properties. So far, experimental data have been reported on Cr−Si−N coating, nanocrystalline phases, and thin films, together with theoretically predicted 1D and 2D hetero‐structures, and 3D bulk Cr2SiN4 modifications. This study predicts possible bulk Cr−Si−N phases with the composition CrSi2N4. A multi‐methodological approach has been employed to explore the system's energy landscape, where global optimization was combined with data mining and the Primitive Cell for Atom Exchange (PCAE) method. Local optimization of the structure candidates was performed on the DFT level using the GGA‐PBE and the LDA‐PZ approximation. The ten energetically most favorable structure candidates discovered in the CrSi2N4 chemical system mostly exhibited monoclinic symmetry but with a variety of structural features, from zeolite‐like structures to polytypic behavior. Finally, the bulk modulus of these possible modifications was computed for a pressure range of up to 10 GPa. [ABSTRACT FROM AUTHOR]

Studying the interaction of inorganic systems with organic ones is a highly important avenue for finding new drugs and treatment methods. Tumor cells show an increased demand for amino acids due to their rapid proliferation; thus, targeting their metabolism is becoming a potential oncological therapeutic strategy. One of the inorganic materials that show antitumor properties is titanium dioxide, while its doping was found to enhance interactions with biological systems. Thus, in this study, we investigated the energy landscape of glutamine (L), an amino acid, on pristine and doped TiO2 surfaces. We first locally optimized 2D-slab structures of pristine and Au/Ag/Cu-doped anatase (001 and 101 surfaces) and similarly optimized a single molecule of glutamine in vacuum. Next, we placed the pre-optimized glutamine molecule in various orientations and on a variety of locations onto the relaxed substrate surfaces (in vacuum) and performed ab initio relaxations of the molecule on the substrate slabs. We employed the DFT method with a GGA-PBE functional implemented in the Quantum Espresso code. Comparisons of the optimized conformations and electronic structures of the amino acid in vacuum and on the surfaces yield useful insights into various biological processes. [ABSTRACT FROM AUTHOR]