Application of multivariate analysis on spectroscopic data.

U ovoj tezi su primenjene hemometrijske metode u dekompoziciji fluorescentnih i FTIR spektara, dobijenih snimanjem uzoraka nanočestica, proteina i bioloških uzoraka. U cilju dekompozicije spektralnih podataka korišćene su: multivarijaciona rezolucija krivih, analiza glavnih komponenti i paralelna faktorska analiza. Ove analize su rađene u cilju: (i) karakterisanja nanočestica (kvantnih i karbonskih tačaka) koje imaju različite vrste primena, (ii) proučavanja strukturnih promena ćelijskog zida koje nastaju usled mutacija u biosintezi njegovih konstitutivnih polimera u cad-c cad-d mutantu u odnosu na divlji tip Arabidopsis thaliana, (iii) praćenja strukturnih prelaza kod proteina goveđi serum albumin (BSA) usled interakcije sa ATP-om. Multivarijaciona rezolucija krivih je pokazala da se struktura nanosenzora ZnS:Mn2+ ne menja funkcionalizacijom sa dendrimerom PAMAM-OH. Ovo ukazuje da se ovaj nanosenzor može koristiti za detekciju i kvantifikaciju Cd2+. Ista hemometrijska metoda je pokazala da je kompleks CDs-MSA stabilan nakon dodavanja Ag+ jona, što ukazuje na veliku selektivnost ovog senzora u detekciji Ag+ jona...In this thesis chemometric methods in decomposition of fluorescent and FTIR spectra were applied. The spectra were obtained by recording samples of nanoparticles, proteins and biological samples. Decomposition of spectral data was performed by using: multivariate curve resolution, principal components analysis and parallel factor analysis. These analyses were carried out in order to: (i) characterize nanoparticles (quantum and carbon dots) that have a variety of applications, (ii) study the structural changes in the cell wall due to mutations in the biosynthesis of its constituent polymers in cad-c cad-d mutant of Arabidopsis thaliana and compare with the wild-type, (iii) monitor the structural transition in the case of the protein bovine serum albumin (BSA) as a result of interaction with ATP. Multivariate curve resolution showed that the structure of nanosensors ZnS:Mn2+ does not change by funkcionalization with PAMAM-OH dendrimer. This indicates that this nanosensor can be used for detection and quantitation of Cd2+. The same chemometric methods showed that the complex MSA-CDs is stable after addition of Ag+ ions, which indicates a high selectivity of the sensor in detection of Ag+ ions. In the study of fluorescent CdSe quantum dots doped with phosphate porous heterostructures (PPH-NH2@CdSe), multivariate curve resolution showed that the CdSe emission band does not change under the influence of the solid support (that are photostable) and can be used as an agent for labeling finger prints. This photostability of PPH-NH2@CdSe proved to be a feature that improves image quality of latent fingerprints on non-porous surfaces, compared to the usual forensic techniques..

Razlikovanje komercijalnih uzoraka vina korišćenjem fluorescentne spektroskopije i multivarijacione analize

Steady state fluorescence spectroscopy in combination with Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) for spectral analysis has been applied to differentiate commercial samples of wines available on the market. We have chosen the wine trade marks from the two Serbian producers that contain only one wine type, since such approach is a starting step for further analyses of the more complex samples containing different wine types. We also studied changes of the emission spectra of these samples during seven days after opening of the wine bottle. The emission spectra were recorded in the wavelength range 275 - 500 nm, after excitation in the range 255 - 300 nm. The spectra of the wine samples obtained from the same producer are very similar, i.e. contain the same components in the similar ratios. The changes of spectral components at 315 nm and 430 nm were the basis for differentiation of the wine samples from the two producers, as well as for estimation of the wine stability in time after the bottle opening. The results indicate that this may be a useful approach in fingerprinting wines from various producers, as well as in screening the stability of wine.Fluorescentna spektroskopija u kombinaciji sa metodom Multivarijaciona Rezolucija Krivih - Naizmenični Najmanji Kvadrati (Multivariate Curve Resolution - Alternating Least Squares, MCR-ALS), je primenjena za razlikovanje komercijalnih uzoraka vina dostupnih na tržištu. Odabrali smo trgovačke marke vina od dva srpska proizvođača koje sadrže samo jednu vrstu vina, jer je ovakav pristup početni korak za kasnije analize složenijih uzoraka koji sadrže različite vrste vina. Takođe smo proučavali promene emisionih spektara ovih uzoraka u toku sedam dana posle otvaranja boce. Emisioni spektri su mereni u opsegu talasnih dužina 275 - 500 nm, posle pobuđivanja u opsegu 255 - 300 nm. Spektri uzoraka vina od istog proizvođača su veoma slični, to jest sadrže iste komponente u sličnom međusobnom odnosu. Promene komponenata spektara na 315 nm i 430 nm bile su osnova za razlikovanje uzoraka vina od dva proizvođača, kao i za procenu stabilnosti vina u vremenu posle otvaranja boce. Rezultati ukazuju da ovo može biti koristan pristup u razlikovanju vina od različitih proizvođača, kao i u praćenju stabilnosti sastava vina

Assesing oil yield stability of rapeseed using AMMI model

Cilj ovog rada bio je da se primenom AMMI modela dobiju informacije o stabilnosti prinosa ulja uljane repice. Prosečan prinos ulja u periodu 2015-2018. godine bio je 989,83 kg/ha. Najveći prosečni prinos ulja je ostvarila sorta Jelena. Analizom varijanse je pokazano da su genotip, godina i interakcija genotip x spoljna sredina značajno uticali na prinos ulja. Najveću vrednost IPC1 skora je imala 2016. godina, što znači da su genotipovi tada ispoljili najveću interakciju sa okruženjem. Kata, Zorica i Jasna su se pokazale kao najstabilnije u pogledu prinosa ulja. Od njih se Zorica, kao prinosnija, preporučuje za gajenje na lokalitetu Rimski šančevi.The aim of this work was to assess rapeseed oil yield stability with the AMMI model. Average oil yield in the period 2015-2018 was 989.83 kg/ha. The highest mean oil yield was accomplished by cultivar Jelena. Analysis of variance showed that genotype, year, and genotype x environment interaction significantly affected oil yield. The highest value of IPC1 score was in 2016, meaning that genotypes showed the greatest interaction with the environment during that year. Kata, Zorica and Jasna proved to be the most stable in terms of oil yield. Since Zorica had both high and stable yield, this cultivar is recommended for cultivation on the site Rimski šančevi

Fluorescence spectroscopy and Multivariate Analysis for the assessment of stability of the cereal flours during storage and thermal processing

In this work, we used Fluorescence spectroscopy in combination with the Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) algorithm for the assessment of stability of the cereal flours, based on stability of their individual fluorescence components, which can be altered by shelf life or heating. The tested samples were commercial maize flour (Maize flour for human consumption),wheat (T-500) and graham flour, purchased directly from a local market. The fluorescence emission spectra of the flour samples were measured in the range of 280 nm to 660 nm with excitation wavelength varing from 250 nm to 360 nm in 10-nm steps. Resulting from the analysis, the four flourescence components were derived from the emission spectra of every analyzed sample. Our results showed that the components' positions were unchanged for all flours after 2 months storage, whereas for the samples with thermal processing at 180 °C during 1 h, the positions were shifted. This method may be useful and simple for screening of a large number of flour samples

Akademska samoregulacija učenika s lakom intelektualnom ometenošću

The aim of this research is to determine the types of academic self-regulation in students with mild intellectual disability and their relation with the examinees' age. The sample consists of 120 examinees of both genders. The selection criteria were: IQ characteristic of mild intellectual disability (51 to 69), age between 12 and 15.11, 5th to 8th grade of primary school, and absence of neurological, psychiatric, expressed emotional and multiple disorders. Academic Self-Regulation Questionnaire was used in this research. The results show the dominance of identified academic regulation in students from the sample. However, by weighting variables, the sample manifested a controlled type according to the unique motivation continuum. It was determined that intrinsic motivation of twelve-year-olds is higher than intrinsic motivation of students in other age groups. Also, we can conclude that statistically significant difference was determined in the level of self-regulation among the examinees of different ages. This means that the behavior of twelve-year-olds is more self-regulated than that of fifteen-year-old students.Ciljevi ovog istraživanja su utvrđivanje zastupljenosti tipova akademske samoregulacije kod učenika s lakom intelektualnom ometenošću, kao i utvrđivanje njihovog odnosa sa kalendarskim uzrastom ispitanika. Uzorak učenika istraživanja uključuje 120 ispitanika, oba pola. Kriterijumi za izbor ispitanika podrazumevali su: količnik inteligencije učenika karakterističan za laku intelektualnu ometenost (od 51 do 69), kalendarski uzrast od 12 do 15 godina i 11 meseci, školski uzrast koji je podrazumevao uključivanje učenika od V do VIII razreda i odsustvo neuroloških, psihijatrijskih, izraženih emocionalnih i višestrukih smetnji. U istraživanju je korišćen Upitnik akademske samoregulacije (Academic Self-Regulation Questionnaire). Rezultati pokazuju dominaciju akademske identifikovane regulacije kod učenika našeg uzorka. Ipak, uzorak je, ponderisanjem varijabli, ispoljio kontrolisani tip prema jedinstvenom kontinuumu motivacije. Utvrđeno je da je intrinzična motivacija dvanaestogodišnjaka viša od intrinzične motivacije učenika koji pripadaju ostalim uzrasnim grupama. Takođe, možemo da zaključimo da je među ispitanicima različitih uzrasnih grupa utvrđena statistički značajna razlika u stepenu samoodređenja. To bi značilo da učenike od 12 godina odlikuje ponašanje koje je više samoodređeno, nego što je to slučaj sa učenicima od 15 godina

NON-INVASIVE CHARACTERIZATIONOF AFLATOXIN-STRESSED WHEAT SEEDSUSING 2D EPR IMAGING AND EEM FLUORESCENCE SPECTROSCOPY

In this work, two non-invasive and independent methods for the characterization of aflatoxin-stressed wheat seeds were applied.Aflatoxins (AFs) are secondary toxic fungi metabolites, which exhibit hazardous effects on plants (phytotoxic), as well as on humans and animals. First, for 2D EPR imaging, we used 3-CP spin probe for the estimation of changes in the redox state of the aflatoxin-stressed seed. On the other side, an excitation-emission fluorescence approach was used to evaluate the spectral profiles of the key biological molecules. We determined their areas and the ratio of the two emission peaks at 355 nm (Ex 290) and 430 nm (Ex 350), corresponding to protein and phenol emission, respectively. Our results showed that the ratio of the two peaks (p/f) decreased in the presence of AFs. Both methods revealed to be useful for the rapid, non-invasive assessment of the seeds' stress state induced by AFs

Luminescence transitions of Pr3+ (4f2) in fluorapatite nanocrystals for potential biomedical application

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

Synthesis and characterization of luminescent Pr3+–doped hydroxyapatite nanopowder as a potential biomaterial for bioimaging applications

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

[Physicochemical Parameters As Indicators Of The Authenticity Of Monofloral Honey From The Territory Of The Republic Of Serbia] [Физикохемиски Параметри Како Индикатори На Автентичноста На Моноцветен Мед Од Територијата На Република Србија]

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. Physico-chemical 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

Effects Of Genotype And Bradyrhizobium Inoculation On Morphological Traits, Grain Yield And Protein Content Of Soybean Varieties

Effects of genotype and Bradyrhizobium inoculation on morphological traits, grain yield and protein content of soybean varieties.- Genetika, Vol 53, No.2, 911-925. Soybean crop production in Serbia involves seed inoculation by N-fixing bacteria just before sowing time. The main objective of the current work was to assess the impact of the genotype and inoculation on range of morphological and yield traits of soybean (Glycine max L. Merrill), as well as the total protein content. The experiment was conducted on chernozem soil, where soybean was previously grown. The six local varieties were used, where each variety was sown, in three replicates for both inoculated and non-inoculated treatment. The following morphological traits were analysed: the plant height, number of lateral branches, distance to the first pod, number of pods per plant, pods (containing seeds) weight per plant, seed weight per plant, and the total grain yield. The total protein content in seeds was determined by standard analytical method, while subtle differences in qualitative protein composition were assessed using Raman spectroscopy. The total protein content varied from 39.6 to 42.15 %. Performance of inoculation resulted in an increase of the plant height and the distance to the first pod, although not in all tested varieties. The highest and the lowest plant height values were observed for non-inoculated variety Dana (59.23cm) and Sava (80.03cm), respectively. The effect of genotype was much more expressed causing differences in almost all tested characters, except for the total protein content. However, Raman spectroscopy analyses revealed distinct discrimination among surveyed varieties, and differences between inoculated and non-inoculated plants in qualitative composition of seed proteins