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In this study, luminescence and antibacterial behavior of pure fluorapatite (FAp) and praseodymium- nitrate-carbonate co-doped fluorapatite (PrNCFAp) nanopowders were investigated. Uniform nanopowders were synthesized by precipitation reaction followed by centrifugation and systematically characterized by XRD, FTIR, SEM–EDS, TG and PL methods. XRD analysis revealed the formation of hexagonal FAp crystals, and FTIR spectra indicate the presence of nitrate ( NO3 −) and carbonate ( CO3 2−) species. SEM analyzes confirm agglomerates composed of irregular nanometer-sized spheres. Emission of FAp nanopowder occurred in the violet-blue region of the visible part of the spectrum, with redshift to the blue-green color region when Pr3+, NO3 − and CO3 2− co-doped in the lattice. Analysis of luminescence spectra by MCR-ALS method extract three fluorophores from the PrNCFAp sample and showed simultaneous existents of emission-reabsorption-emission between dopants in FAp lattice. Antibacterial activity against pathogen Staphylococcus aureus was investigated before and after treatment of nanopowders by UVA radiation of 365 nm. Nanopowders irradiated with UVA compared to non-irradiated reduced Staphylococcus aureus by 84.9% for PrNCFAp and 33.3% for FAp in the first 0.5 h of contact, and 76.1% and 42.9% after 24 h of contact. In addition, the obtained luminescent nanomaterials showed a low degree of hemolytic activity and could potentially be candidates for further research in dentistry.

Fluorapatite (FAP) crystals have drawn significant interest over the last few decades as important hosts matrix for optically active trivalent rare earth ions, due to the strong crystal field splitting and large transition cross-sections. Nano-sized FAP particles doped with rare earth ions have been extensively studied as luminescent materials for biomedical applications for cell labeling and bioimaging, as well as antimicrobial agents for therapeutics.Fluorapatite nanoparticles doped with praseodymium ions (Pr3+) were prepared by the co precipitation method and characterized. The different number of Pr3+ (4f2) transitions in the ultraviolet and visible parts of the spectrum was investigated by photoluminescence spectroscopy. Multivariate Curve Resolution–Alternating Least Squares (MCR-ALS) analyses of fluorescence spectra and ab initio calculation indicated that Pr3+ ions are preferentially substituted Ca2 (6h) sites in FAP lattice. In addition to the substitution of cations, there is also the substitution of anionic species such as OH-, CO32-, and NO3-, which are confirmed by the CHNS method. The obtained samples were tested as bioimaging and antibacterial agents and can potentially be used for further biomedical research.

Praseodymium doped calcium hydroxyapatite (PrHAP) nanopowder was synthesized by the co-precipitation method and characterized by X-Ray Diffraction, Fourier Transform Infrared, and Fluorescence Spectroscopy. Characterization studies from XRD and FTIR spectra showed that obtained crystals are monophase hydroxyapatites and that the sample particles are of nano size. A fluorescence study has shown that PrHAP particles have fluorescent emission under UV‐ Visible excitation. These results may open new avenues for developing bioactive materials for bone regeneration and fluorescent probes for bio-imaging applications.

Genetic potential of rapeseed for reaching high seed and oil yield can be jeopardized by multiple environmental factors that shape rapeseed performance and stability at different growing sites. A combination of high temperatures and drought during sowing make the germination and initial plant growth critical phases for successful rapeseed production in Serbia. Thousand seed weight is related to seed size, which affects seeding rate as well as speed of germination and emergence and is important to achieve high yield potential. The goal of this study was to study changes in thousand seed weight of rapeseed in response to different environments. Furthermore, we sought to determine genotypes that had high and stable thousand seed weight values. Additional goal was to implement additive main effects and multiplicative interaction model (AMMI) to partition genotype × environment interactions.

In this preliminary study, we applied the Multivariate Curve Resolution- Alternating Least Squares (MCR-ALS) method to analyze the excitation-emission matrices of multifloral honey samples, combined with differential scanning calorimetry (DSC) to estimate infection of honey bee colonies with N. ceranae or V. destructor. Fluorescence spectroscopy combined with MCR-ALS was used to determine the ratio of the spectral components originating from proteins (C1) and phenolics (C2), two minor but essential constituents of honey, as a ratiometric indicator of infection level in related hives. The C1/C2 ratio decreased linearly with the increase of infection in both N. ceranae and V. destructor cases, the R2 was 0.941 and 0.912, respectively. Additionally, DSC has shown that the magnitude of changes in sugar environments of the honey samples, reflected in sugar phase transitions, rises with increasing infection level in bee colonies. These results indicate that fluorescence combined with MCR-ALS could be used for rapid, non-destructive and cheap screening of honey to estimate the level of infection of honey bee colonies.

Aflatoxin B1 (AFB1), is a naturally hazardous environmental contaminant, contained mainly in various cereal seeds. The maize (Zea mays L.) seeds containing various levels of the AFB1 was investigated using optical and electron paramagnetic resonance spectroscopies. The changes of lignin content and organic free radicals as indicators of the seeds' defense response to the AFB1-stressor were estimated, in the seeds' inner and outer fractions. The lignin content was determined using the Acetyl Bromide method. No correlation was found between the lignin content and the AFB1 concentration in the inner fraction (R of 0.030, p = 0.943), while a significant positive linear correlation (R of 0.9923, p= 0.00005) between the lignin content and the AFB1 concentration in the outer fraction was obtained. Employing electron paramagnetic resonance (EPR) spectroscopy, the different response of the fractions was observed, regarding the content of free radicals with increasing AFB1 concentrations. In addition, front-face fluorescence spectroscopy in combination with the deconvolution showed a positive linear correlation between the ratio of the green and blue spectral emission components (C4/C2) area and the AFB1 concentration in the outer fraction. Thus lignin content and the (C4/C2) area ratio may be reliable indicators for the screening of lignin changes related to the level of AFB1 in the seeds.

Salata (Lactuca sativa L.) je jednogodišnja biljka, sa umerenimzahtevima prema faktorima spoljašnje sredine, kratkim vegetacionimperiodom i mogućnošću gajenja tokom cele godine. Ogledi sa šestgenotipova salate (‘Kiribati’, ‘Murai’, ‘Aquino’, ‘Gaugin’, ‘Aleppo’,‘Carmesi’) bili su postavljeni u kompaniji Iceberg Salat Centar. Biljke sugajene u plasteniku, bez dodatnog grejanja, tokom tri uzastopne sezone(jesen, zima i proleće), primenom mikrobioloških đubriva (EM Aktiv,Vital Tricho i njihova kombinacija). Cilj ovog istraživanja je bio da seutvrdi uticaj genotipa, mikrobioloških đubriva i sezone na sadržaj ukupnorastvorljivih materija i organskih kiselina. Najveću vrednost ukupnorastvorljivih materija i organskih kiselina ostvarila je crvena sorta ‘Murai‘u zimskom ogledu primenom đubriva Vital Tricho i EM Aktiv redom.Primena đubriva uglavnom nije uticala na vrednosti ukupno rastvorljivihmaterija i organskih kiselina, gde je tokom svih sezona sadržaj ostaostabilan. Istraživanje je pokazalo da su glavni faktori uticali naposmatrane parametre, sa izraženim uticajem genotipa., Lettuce (Lactuca sativa L.) is an annual plant, with moderate requirements to environmental factors, short vegetation period and the possibility to cultivate throughout whole year. Trials with six lettuce cultivars (‘Kiribati’, ‘Murai’, ‘Aquino’, ‘Gaugin’, ‘Aleppo’, ‘Carmesi’) were set up in the company Iceberg Salat Centar. The plants were grown in a greenhouse, without additional heating, during three consecutive seasons (autumn, winter and spring), using microbiological fertilisers (EM Aktiv, Vital Tricho and their combination). The aim of this study was to determine the influence of genotype, microbiological fertilisers and season on the content of total soluble solids and organic acids. The highest value of total soluble solids and organic acids showed red cultivar 'Murai' in the winter trial using fertilisers Vital Tricho and EM Aktiv, respectively. Application of fertilisers generally did not affect the values of total soluble solids and organic acids, whereas the content remained stable during all seasons. The research showed that the main factors influenced tested parameters, with a great impact of the genotype.

Controlled drug delivery systems are of great interest in modern science and medicine. This study was oriented towards encapsulation of synthetic lignin (DHP) into alginate beads and investigation of its release kinetic. Encapsulation was achieved by the ionotropic gelation method. In vitro release profiles were fitted into four release kinetic models (zero-order, first-order, Higuchi, and Korsmeyer-Peppas). According to the in vitro release, data alginate beads showed initial burst release followed by prolonged release. The best correlation was found for the Korsmeyer-Peppas model (R2 = 0.948), with an n value lower than 0.43, indicating the DHP transport mechanism was controlled by quasi-Fickian diffusion. This delivery system could be promising for chronic wound care and antibacterial treatment.

Leaning stems of woody plants form reaction wood, in hardwood trees termed tension wood. Tension wood contains more cellulose and less lignin and it is anatomically different from normal wood. Fourier-transform infrared (FTIR) spectroscopy showed that there was no difference in lignin content in segments of bent trees compared to the controls, but the higher amounts of cellulose, xylan, and xyloglucan were observed in bent trees, corresponding to the rearrangements in the cellulose/xyloglucan network.

The principal sesquiterpene lactones (lactucin, lactucopicrin, and its dihydro forms), known as contributors to bitter taste, were measured in green and red coloured lettuce using Ultra-performance liquid chromatography. Six lettuce cultivars (‘Kiribati’, ‘Murai’, ‘Aquino’, ‘Gaugin’, ‘Aleppo’ and ‘Carmesi’) were grown in a greenhouse experiment using microbiological fertilisers (EM Aktiv, Vital Tricho, and their combination) during three successive growing seasons (autumn, winter, and spring). The major sesquiterpene lactone was lactucopicrin with the highest level found in cultivar ‘Carmesi’ (0.65 mg/g dry weight) in autumn with the combination of fertilisers. The concentrations of lactucin, dihydrolactucin and dihydrolactucopicrin ranged from 0.001-0.085, 0.003-0.015, and 0.001-0.056 mg/g dry weight, respectively, and were not found in all lettuce samples. Generally, red cultivars showed higher content of lactones compared to green. Application of Vital Tricho and the combination of fertilisers led to an increased level of lactucopicrin, in some cultivars, in the range of 77-800% compared to unfertilised plants. Higher levels of lactucopicrin were found in the autumn trial compared to spring and winter. The present study suggests that genotype, fertilisers and season jointly affected the quantity of sesquiterpene lactones with emphasis on Vital Tricho, and/or the combination of fertilisers.

In this preliminary study, we applied the Multivariate Curve Resolution- Alternating Least Squares (MCR-ALS) method to analyze the excitation-emission matrices of multifloral honey samples, combined with differential scanning calorimetry (DSC) to estimate infection of honey bee colonies with N. ceranae or V. destructor. Fluorescence spectroscopy combined with MCR-ALS was used to determine the ratio of the spectral components originating from proteins (C1) and phenolics (C2), two minor but essential constituents of honey, as a ratiometric indicator of infection level in related hives. The C1/C2 ratio decreased linearly with the increase of infection in both N. ceranae and V. destructor cases, the R (2) was 0.941 and 0.912, respectively. Additionally, DSC has shown that the magnitude of changes in sugar environments of the honey samples, reflected in sugar phase transitions, rises with increasing infection level in bee colonies. These results indicate that fluorescence combined with MCR-ALS could be used for rapid, non-destructive and cheap screening of honey to estimate the level of infection of honey bee colonies.

BACKGROUND Aflatoxin B-1 (AFB(1)) is the most dangerous of the mycotoxins that contaminate cereal seeds naturally. A stress lignin formation is linked with the accumulation of reactive oxygen species causing a change in the redox status and formation of stable organic radicals, constituting the first layer of defense. The relationship between AFB(1) and changes in lignin organic free radicals in seeds is not known, nor is the part of the seed that is more targeted. Using optical and electron paramagnetic resonance spectroscopy, we investigated AFB(1)-induced changes in lignin and organic free radicals in seeds, and whether the inner and outer seed fractions differ in response to increasing AFB(1). RESULTS Different changes in the content of lignin and free radicals with increasing AFB(1) concentrations were observed in the two seed fractions. There was a significant positive linear correlation (R = 0.9923, P = 0.00005) between lignin content and AFB(1) concentration in the outer fraction, and no correlation between the lignin content and the AFB(1) concentration in the inner fraction. We found a positive correlation between the area of the green spectral emission component (C4) and the AFB(1) concentration in the outer fraction. CONCLUSIONS To the best of our knowledge, the results showed, for the first time, that maize seed fractions respond differently to aflatoxin with regard to their lignin and organic free radical content. Lignin content and (C4) area may be reliable indicators for the screening of lignin changes against AFB(1) content in the seeds, and thus for seed protection capacity.

Lettuce is a worldwide grown leafy vegetable rich in phytochemicals which are essential in human diet. The aim of this study was to examine the effect of genotype, microbiological fertilisers and season on the rosette fresh weight and components of antioxidant activity. Six cultivars (green ‘Kiribati', ‘Aleppo', ‘Aquino' and red ‘Murai', ‘Carmesi', ‘Gaugin‘) were grown in a greenhouse experiment during three consecutive seasons (autumn, winter and spring) with application of microbiological fertilisers (EM Aktiv, Vital Tricho and their combination). Green cultivars showed higher fresh weight than red in spring and winter. Green cultivar ‘Aleppo’ showed the highest fresh weight in control during spring. Microbiological fertilisers led to increased fresh weight in autumn. Mainly, red cultivars showed higher quality parameters compared to green (total antioxidant capacity, total phenolic content, total carotenoids and POD activity). Red cultivar ‘Carmesi' showed the highest total antioxidant capacity, total carotenoids, and total phenolic content in winter with combination of fertilisers, Vital Tricho, and in control. In spring, ‘Carmesi' and ‘Gaugin' showed the highest POD activity with Vital Tricho, and combination of fertilisers. The present study suggested that genotype, fertilisers and season jointly influenced quantity and quality parameters with emphasis on Vital Tricho, and/or combination of fertilisers.

Two tomato genotypes with constitutively different ABA level, flacca mutant and wild type of Ailsa Craig cv. (WT), were subjected to three repeated drought cycles, with the aim to reveal the role of the abscisic acid (ABA) threshold in developing drought tolerance. Differential responses to drought of two genotypes were obtained: more pronounced stomatal closure, ABA biosynthesis and proline accumulation in WT compared to the mutant were compensated by dry weight accumulation accompanied by transient redox disbalance in flacca. Fourier-transform infrared (FTIR) spectra analysis of isolated cell wall material and morphological parameter measurements on tomato leaves indicated changes in dry weight accumulation and carbon re-allocation to cell wall constituents in flacca, but not in WT. A higher proportion of cellulose, pectin and lignin in isolated cell walls from flacca leaves further increased with repeated drought cycles. Different ABA-dependent stomatal closure between drought cycles implies that acquisition of stomatal sensitivity may be a part of stress memory mechanism developed under given conditions. The regulatory role of ABA in the cell wall restructuring and growth regulation under low leaf potential was discussed with emphasis on the beneficial effects of drought priming in developing differential defense strategies against drought.

The aim of this research was to verify the authenticity of monofloral honeys from the territory of the Republic of Serbia on the basis of physicochemical parameters routinely measured in honey quality control using multivariate analysis. Seventeen samples of monofloral honey (11 samples of acacia honey and 6 samples of sunflower honey) from the territory of the Republic of Serbia were analyzed. Physicochemical analysis of the samples included the examination of basic quality parameters and qualitative and quantitative analyses of phenolic compounds. In the samples tested, a total of 93 phenolic compounds were tentatively identified, and 19 of them were quantified. The obtained physicochemical analysis of the data served as input for the multivariate analysis. The hеаt map, which is useful for visualizing numerical data, was used for this purpose. The obtained results showed that the applied data can serve to clearly separate acacia and sunflower honeys.

In this preliminary study, we applied the Multivariate Curve Resolution- Alternating Least Squares (MCR-ALS) method to analyze the excitation-emission matrices of multifloral honey samples, combined with differential scanning calorimetry (DSC) to estimate infection of honey bee colonies with N. ceranae or V. destructor. Fluorescence spectroscopy combined with MCR-ALS was used to determine the ratio of the spectral components originating from proteins (C1) and phenolics (C2), two minor but essential constituents of honey, as a ratiometric indicator of infection level in related hives. The C1/C2 ratio decreased linearly with the increase of infection in both N. ceranae and V. destructor cases, the R2 was 0.941 and 0.912, respectively. Additionally, DSC has shown that the magnitude of changes in sugar environments of the honey samples, reflected in sugar phase transitions, rises with increasing infection level in bee colonies. These results indicate that fluorescence combined with MCR-ALS could be used for rapid, non-destructive and cheap screening of honey to estimate the level of infection of honey bee colonies.