Mechanochemical synthesis of bismuth ferrite

A powder mixture of Bi2O3 and Fe2O3 was mechanically treated in a planetary ball mill in an air from 30 to 720 minutes. It was shown that the mechanochemical formation of BiFeO3 (BFO) phase was initiated after 60 min and its amount increased gradually with increasing milling time. A detailed XRPD structural analysis is realized by Rietveld’s structure refinement method. The resulting lattice parameters, relative phase abundances, crystallite sizes and crystal lattice microstrains were determined as a function of milling time. Microstructural analysis showed a little difference in morphology of obtained powders. The primary particles, irregular in shape and smaller than 400 nm are observed clearly, although they have assembled together to form agglomerates with varying size and morphology. Dense BFO ceramics were prepared by conventional solid-state reaction at the temperature of 810ºC for 1h followed immediately by quenching process. [Projekat Ministarstva nauke Republike Srbije, br. III45007: Zero- to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processin

Kinetics of nanocrystalline phase transformations in spray pyrolysed ZnO particles

The thermal behavior of ZnO powder obtained by ultrasonic spray pyrolysis of nitrate solution (c=0.8mol/dm3, D0=2.695µm, Tmax=6000C, FG=1.2dm3/min) was investigated using non-isothermal differential scanning calorimetry (DSC, heating rates 5, 10, 15, 20O/min). The exothermic heat effects at the temperature range from 350 to 5000C were linked to particles structural data obtained by XRD, SEM and TEM analysis. Produced particles are characterized by uniform submicronic size (D=800nm, BET=4.94m2/g), high phase purity and granular or circular “open” surface due to the presence of primary crystallites (d= 20nm). Observed structural changes during heating of this powder were attributed to simultaneous processes of nucleation and growth of primary crystallites inside the produced particles

Research on long-term colonization of goosander (Mergus merganser Linneaus, 1758) with reference to habitat availability

This article presents data on long-term colonization of goosander in Western Serbia and Eastern Republic of Srpska (on five oligotrophic reservoirs formed by the Drina River) based on continuous counting since the first observation of nesting in 1987. The total number of breeding pairs and their distribution in neighboring habitats continuously increased from year to year, suggesting that expansion of the population is still below the limit of the habitat. The decrease in population which occurred in certain years was due to environmental or anthropogenic influence.U ovoj studiji prikazani su podaci o dugotrajnoj kolonizaciji Mergus merganser L. u zapadnoj Srbiji i u istočnom delu Republike Srpske, i to na pet oligotrofnih jezera nastalih od reke Drine. Ukupan broj parova i njihova distribucija u okolnim staništima se kontinuirano povećava iz godine u godinu, što ukazuje na činjenicu da je ekspanzija te populacije još uvek ispod optimalnih granica koje dato stanište pruža. Pad brojnosti populacije tokom ranijih godina bio je uslovljen uticajem sredine ili antropogenim delovanjem.nul

The synthesis: Structure relationship in the ZnO-Cr2O3 system

In this work the development of the spinel phase in the ZnO-Cr2O3 system was discussed from the viewpoint of the synthesis-structure relationship. The nanostructure evolution in particles obtained either via solution-based (spray pyrolysis) or solid-state (mechanical activation) synthesis procedures were investigated by XRD analysis. A detailed structural analysis of the spinel phase lattice parameters, average primary crystallite sizes and micro strains were performed in accordance with a procedure based on the Koalariet-Xfit program. Due to the importance of spinel-phase cat ion distribution for chemical and physical properties, a study of the site occupation factors, i.e. changes in the stoichiometric, of ZnCr2O4 spinals was undertaken. The calculation based on atomistic methods for the description of both perfect and defect spinel ZnCr2O4 crystal lattices has been applied and the presence of individual structural defects was determined

Research on long-term colonization of goosander (Mergus merganser Linneaus, 1758) with reference to habitat availability

This article presents data on long-term colonization of goosander in Western Serbia and Eastern Republic of Srpska (on five oligotrophic reservoirs formed by the Drina River) based on continuous counting since the first observation of nesting in 1987. The total number of breeding pairs and their distribution in neighboring habitats continuously increased from year to year, suggesting that expansion of the population is still below the limit of the habitat. The decrease in population which occurred in certain years was due to environmental or anthropogenic influence.U ovoj studiji prikazani su podaci o dugotrajnoj kolonizaciji Mergus merganser L. u zapadnoj Srbiji i u istočnom delu Republike Srpske, i to na pet oligotrofnih jezera nastalih od reke Drine. Ukupan broj parova i njihova distribucija u okolnim staništima se kontinuirano povećava iz godine u godinu, što ukazuje na činjenicu da je ekspanzija te populacije još uvek ispod optimalnih granica koje dato stanište pruža. Pad brojnosti populacije tokom ranijih godina bio je uslovljen uticajem sredine ili antropogenim delovanjem.nul

Aktivnost antioksidativnih enzima u ponicima grahorica u uslovima suše

Drought greatly affects normal plant growth, endangering physiological and biochemical processes in plants. Under the influence of unfavorable environmental conditions, antioxidant protection systems in plant cell can be activated regardless of the stage of growth and development of plants. The experiment was conducted on three vetches species (V. sativa, V. villosa and V. pannonica) under PEG-induced drought stress. Activity of antioxidant enzymes: superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APx, EC 1.11.1.1) and catalase (CAT, EC 1. 11. 1. 6), was determined in shoots and roots of 10-day-old seedlings. Lack of water during germination period activated all the examined antioxidant enzymes in both organs of all tested Vicia species. The activity of SOD and APx generally increased at higher stress levels, while the enzyme CAT showed different patterns of action in all tested species. The results of this study suggest that drought stress causes the production of oxygen radicals that lead to oxidative stress in plants.Suša značajno utiče na normalan rast i razvoj biljaka ugrožavajući fiziološke i biohemijske procese. U nepovoljnim uslovima spoljašnje sredine, antioksidantni sistemi zaštite u biljnim ćelijama mogu se aktivirati bez obzira na fazu rasta i razvoja biljaka. Ovaj eksperiment je sproveden na tri vrste grahorica (V. sativa, V. villosa i V. pannonica) u uslovima suše indukovane PEG-om. Aktivnost antioksidantnih enzima superoksid dismutase (SOD), askorbat peroksidaze (APx) i katalaze (CAT) merena je u nadzemnom delu i korenu ponika starim deset dana. Nedovoljna količina vode u početnim fazama rasta aktivirala je sve ispitivane antioksidativne enzime u nadzemnom delu i u korenu ponika svih ispitivanih vrsta roda Vicia. Aktivnost SOD i APx se povećala na višim nivoima stresa, dok su se kod enzima katalaza uočili različiti obrasci delovanja u svim testiranim vrstama. Rezultati ovog eksperimenta ukazuju na povećanu produkciju radikala kiseonika u sušnim uslovima koji dovode do oksidativnog stresa u biljkama

Threshold Level and Traceability of Roundup Ready (R) Soybeans in Tofu Production

The aim of this study is to assess DNA degradation, DNA amplification, and GMO quantity during tofu production. Soybean seeds were spiked with Roundup Ready (R) soybeans (RRS) at 0.9, 2, 3 and 5 % (by mass), to assess the level of RSS that would be of practical interest for threshold labelling. Real-time polymerase chain reaction (PCR) was more effective than conventional PCR in the analysis of raw soymilk, okara, boiled soymilk and tofu. The negative effect of grinding and mechanical manipulation was obvious in the okara sample prepared with 3 and 5 % RRS, where GMO content was reduced to (2.28 +/- 0.23) and (2.74 +/- 0.26) %, respectively. However, heating at 100 degrees C for 10 min did not cause significant degradation of DNA in all samples. The content of RRS in the final product, tofu, was reduced tenfold during processing, ranging from 0.07 to 0.46 %, which was below the labelling threshold level. The results are discussed in terms of global harmonization of GMO standards, which could have the positive effect on the trade of lightly processed foodstuffs such as tofu, especially regarding the labelling policies

Molekularna identifikacija Bradyrhizobium japonicum sojeva izolovanih iz korenskih kvržica soje (Glycine max L.)

The aim of this study was to isolate and identify Bradyrhizobium japonicum strains on the basis of molecular characteristics. From root nodules of different soybean cultivars were obtained 56 isolates, characterized according to morphological, cultural, and biochemical properties. Among these isolates, 33 isolates showing resemblance with Bradyrhizobium sp. were further subjected to molecular identification. Following DNA extraction, a partial 16S rDNA gene sequence from the isolates was amplified by PCR using universal primers fD1 (27F) and rP3 (1492R). Purification and sequencing of the amplified fragments were done in the biotechnology company Macrogen, Seoul, South Korea. Sequences were analyzed using the program FinchTV and BLAST (Basic Local Alignment Search Tool) and compared to sequences in GenBank and the Bradyrhizobium ID-database for identification. Comparison of the sequences with the Bradyrhizobium ID- database showed that all tested isolates were identified as Bradyrhizobium japonicum. Each isolate was deposited in the NCBI GenBank database under a unique accession number. Identification of Bradyrhizobium species from root nodules of soybean is of great importance because the symbiosis between rhizobia and legumes are a cheaper and usually more effective agronomic practice for ensuring an adequate supply of nitrogen for legumes, while preserving and improving fertility and productivity of soils.Cilj ovog rada je izolacija i molekularna identifikacija sojeva Bradyrhizobium japonicum. Na osnovu morfološke i biohemijske karakterizacije, od 56 izolata iz korenskih kvržica različitih sorti soje, 33 izolata za koje je utvrđena sličnost s Bradyrhizobium sp. bili su predmet dalje identifikacije. Nakon ekstrakcije DNK, parcijalna 16S rDNA genska sekvenca iz izolata je umnožena PCR metodom upotrebom univerzalnih prajmera fD1 (27F) i rP3 (1492R). Prečišćavanje i sekvencioniranje umnoženih fragmenata urađeno je u kompaniji Macrogen Ltd. (Seul , Južna Koreja). Pomoću programa FinchTV i BLAST (Basic Local Alignment Search Tool) analize, izvršeno je višestruko poređenje dobijenih sekvenci s GenBank bazom podataka. Poređenjem dobijenih sekvenci s Bradyrhizobium ID-bazom podataka svi ispitivani izolati identifikovani su kao Bradyrhizobium japonicum. Sekvence su deponovane u svetsku NCBI bazu uz dobijanje pristupnog broja (NCBI Acc. number). Identifikacija vrsta Bradyrhizobium-a poreklom iz korenskih kvržica soje od velikog je značaja jer je simbioza između rizobiuma i leguminoza isplativiji i obično efikasniji način snabdevanja biljaka azotom, a važno je i zbog očuvanja i unapređenja plodnosti i produktivnosti zemljišta

Morfološka i molekularna identifikacija Fusarium tricinctum i Fusarium acuminatum prouzrokovača truleži belog luka u Srbiji

Garlic (Allium sativum L.) is considered to be one of the oldest crops in the world. During 2016, infected garlic bulbs occurred in storages on several localities of the Province of Vojvodina. Symptomatic cloves showed typical rot symptoms such as softened and spongy areas covered with white fungal growth with deep lesions formed on the cloves which became dry over time. A total of 36 isolates of Fusarium species were obtained from diseased cloves of garlic. Colony morphology and microscopic properties of isolated Fusarium species were recorded from the cultures grown on PDA and CLA, respectively. Identification of two chosen isolates was performed by sequencing the EF-1α gene. The TEF sequence of isolate JBL12 showed 100% similarity with several F. tricinctum sequences and sequence of JBL539 showed 99% identity with several F. acuminatum sequences and they were deposited in the NCBI GenBank. Based on the results of the morphological and molecular identification, isolates JBL12 and JBL539 were identified as F. tricinctum and F. acuminatum, respectively, as new causal agents of garlic bulbs rot in Serbia. Specific primers were designed for the PCR identification of the F. tricinctum.Beli luk (Allium sativum L.) smatra se jednom od najstarijih biljnih vrsta na svetu. Tokom 2016. godine, zapažena je pojava truleži belog luka u skladištima i magacinima na nekoliko lokaliteta u Vojvodini. Simptomi su se ispoljavali u vidu lezija, truleži belog luka kao i pojavom micelije na inficiranim čenovima. Cilj rada bio je izolacija i identifikacija Fusarium spp. na osnovu morfoloških i molekularnih karakteristika patogena. Izolacijom je dobijeno 36 izolata Fusarium spp. Detekcija i identifikacija odabranih izolata potvrđena je metodom PCR korišćenjem prajmera EF1 i EF2 koji amplifikuju proizvode veličine 700bp. U svim proučavanim izolatima formirani su amplikoni veličine 700bp. Izolacija DNK dva odabrana izolata izvršena je direktno iz micelije gljive (~100 mg), korišćenjem DNeasy Plant Mini Kit (Qiagen, Hilden, Germany). Identifikacija izolata JBL539 i JBL12 izvršena je sekvenciranjem EF-1α gena , koji su deponovani u NCBI bazu podataka pod brojem KX611146 (F. tricinctum) i KX752419 (F. acuminatum). Kreirani su specifični prajmeri za PCR identifikaciju vrste F. tricinctum

Antifungalna aktivnost prirodnih Bacillus spp. izolata iz zemljišta

Biocontrol using plant growth-promoting rhizobacteria (PGPR) represents an alternative approach to disease management, since PGPR are known to promote growth and reduce diseases in various crops. Among the different PGPR, members of the genus Bacillus are prefered for most biotechnological uses due to their capability to form extremely resistant spores and produce a wide variety of metabolites with antimicrobial activity. The objective of this research was to identify antagonistic bacteria for management of the plant diseases. Eleven isolates of Bacillus spp. were obtained from the soil samples collected from different localities in the Province of Vojvodina. The antifungal activity of bacterial isolates against five fungal species was examined using a dual plate assay. Bacillus isolates exhibited the highest antifungal activity against Fusarium proliferatum, Fusarium oxysporum f. sp. cepae and Alternaria padwickii, while they had the least antagonistic effect on Fusarium verticillioides and Fusarium graminearum. Molecular identification showed that effective bacterial isolates were identified as Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) and Bacillus megaterium (B8, B9). The highest antagonistic activity was exhibited by isolates B5 (from 39% to 62% reduction in fungal growth) and B7 (from 40% to 71% reduction in fungal growth). These isolates of B. subtilis could be used as potential biocontrol agents of plant diseases.Biokontrola fitopatogena predstavlja alternativu primeni pesticida, s obzirom da bakterije označene terminom PGPR (Plant Growth Promoting Rhizobacteria) stimulišu biljni rast i štite biljke od bolesti. Zahvaljujući sposobnosti da formiraju veoma rezistentne endospore i produkuju širok spektar antimikrobnih supstanci, vrste roda Bacillus su veoma zastupljene u zemljištu i pogodne za primenu u biotehnologiji. Cilj istraživanja bio je da se utvrdi antifungalna aktivnost jedanaest Bacillus spp. izolata iz zemljišta s različitih lokaliteta u Vojvodini. Sposobnost bakterijskih izolata da inhibiraju rast pet izolata gljiva ispitana je metodom dvojne kultivacije. Izolati Bacillus spp. ispoljili su najveću antifungalnu aktivnost prema Fusarium proliferatum, Fusarium oxysporum f. sp. cepae, i Alternaria padwickii, dok je najmanji antagonistički efekat utvrđen prema Fusarium verticillioides i Fusarium graminearum. Efektivni izolati identifikovani su kao Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) i Bacillus megaterium (B8, B9). Najveću antifungalnu aktivnost ispoljili su izolati B. subtilis B5 (39-62%) i B7 (40-71%). Ovi izolati mogu se koristiti kao potencijalni agensi za biološku kontrolu biljnih bolesti