Structure and properties of ZnO/ZnMn2O4 composite obtained by thermal decomposition of terephthalate precursor

A biphasic [Mn(dipya)(H2O)4](tpht)/{[Zn(dipya)(tpht)]•H2O}n complex material, I, (dipya = 2,2’-dipyridylamine, tpht2- = dianion of terephthalatic acid) was synthesized by ligand exchange reaction and characterized by XRPD and FTIR spectroscopy. A ZnO/ZnMn2O4 composite, II, has been prepared via thermal decomposition of precursor I in an air atmosphere at 450°C. XRPD, FTIR and FESEM analyses of II revealed the simultaneous presence of spherical nanoparticles of wurtzite ZnO and elongated nanoparticles of spinel ZnMn2O4. The specific surface area of II was determined by the BET method, whereas the volume and average size of the mesopores were calculated in accordance with the BJH method. The measurements of the mean size, polydispersity index and zeta potential showed colloidal instability of II. Two band gap values of 2.4 and 3.3 eV were determined using UV-Vis diffuse reflectance spectroscopy, while the measurements of photoluminescence revealed that II is active in the blue region of the visible spectrum. Testing of composite II as a pigmentary material showed that it can be used for the colouring of a ceramic glaze.Двофазни [Mn(dipya)(H2O)4](tpht)/{[Zn(dipya)(tpht)]·H2O}n комплексни материјал, I, (dipya = 2,2’-дипиридиламин, tpht2– = дианјон 1,4-бензендикарбоксилне киселине) синтетисан је реакцијом измене лиганада и окарактерисан XRPD мeтoдом и FTIR спектроскопијом. Композит ZnO/ZnMn2O4, II, добијен је термичком разградњом прекурcopa I у атмосфери ваздуха на 450 °C. XRPD мeтoдом, FTIR спектроскопијом и FESEM микроскопијом композита II утврђено је истовремено присуство сферних наночестица ZnO вирцитне структуре и издужених наночестица ZnMn2O4 са структуром спинела. Специфична површина II одређена је BET методом, док су запремина и просечна величина мезопора израчунати у складу са BJH методом. Средња величина, индекс полидисперзије и цета потенцијал измерени су фотонском корелационом спектроскопијом и електрофоретским расејањем светлости и показали су нестабилност композита II. Вредности ширине забрањене зоне 2,4 и 3,3 eV одређене су UV-Vis дифузно-рефлексионом спектроскопијом, док су мерења фотолуминесценције показала да је II активан у плавој области видљивог дела спектра. Испитивање композита II као пигментног материјала показало је да се може користити за бојење керамичке глазуре

Nutrients and soil structure influence furovirus infection of wheat

Soil-borne wheat mosaic virus (SBWMV) and Soil-borne cereal mosaic virus (SBCMV), genus Furovirus, family Virgaviridae, cause significant crop losses in cereals. The viruses are transmitted by the soil-borne plasmodiophorid Polymyxa graminis. Inside P. graminis resting spores, the viruses persist in the soil for long time, which makes the disease difficult to combat. To open up novel possibilities for virus control, we explored the influence of physical and chemical soil properties on infection of wheat with SBWMV and SBCMV. Moreover, we investigated, whether infection rates are influenced by the nutritional state of the plants. Infection rates of susceptible wheat lines were correlated to soil structure parameters and nutrient contents in soil and plants. Our results show that SBWMV and SBCMV infection rates decrease the more water-impermeable the soil is and that virus transmission depends on pH. Moreover, we found that contents of several nutrients in the soil (e.g. phosphorous, magnesium, zinc) and in planta (e.g. nitrogen, carbon, boron, sulfur, calcium) affect SBWMV and SBCMV infection rates. The knowledge generated may help paving the way towards development of a microenvironment-adapted agriculture

Can glial cells save neurons in epilepsy?

Epilepsy is a neurological disorder caused by the pathological hyper-synchronization of neuronal discharges. The fundamental research of epilepsy mechanisms and the targets of drug design options for its treatment have focused on neurons. However, approximately 30% of patients suffering from epilepsy show resistance to standard anti-epileptic chemotherapeutic agents while the symptoms of the remaining 70% of patients can be alleviated but not completely removed by the current medications. Thus, new strategies for the treatment of epilepsy are in urgent demand. Over the past decades, with the increase in knowledge on the role of glia in the genesis and development of epilepsy, glial cells are receiving renewed attention. In a normal brain, glial cells maintain neuronal health and in partnership with neurons regulate virtually every aspect of brain function. In epilepsy, however, the supportive roles of glial cells are compromised, and their interaction with neurons is altered, which disrupts brain function. In this review, we will focus on the role of glia-related processes in epileptogenesis and their contribution to abnormal neuronal activity, with the major focus on the dysfunction of astroglial potassium channels, water channels, gap junctions, glutamate transporters, purinergic signaling, synaptogenesis, on the roles of microglial inflammatory cytokines, microglia-astrocyte interactions in epilepsy, and on the oligodendroglial potassium channels and myelin abnormalities in the epileptic brain. These recent findings suggest that glia should be considered as the promising next-generation targets for designing anti-epileptic drugs that may improve epilepsy and drug-resistant epilepsy.kategorija casopsisa M2

Influence of Spent Fluid Catalytic Cracking Catalyst on the Properties of the New Binder Based on Fly Ash and Portland Cement

One of the measures to reduce the carbon footprint of the Portland cement (PC) manufacturing process is through a wider use of supplementary cementitious and waste materials. The main objective of this work was to produce a new binder using two different waste materials: fly ash FA) from thermal power plants and spent fluid catalytic cracking catalyst (sFCCC) from petrol refineries. In order to improve their reactivity, both FA and sFCCC were mechanically activated prior to the preparation of the binder. The new binder consisted mostly of the waste materials (70 mass %), with PC as a minor component (30 mass %). It was found that using sFCCC as the binder component accelerated cement hydration and the pozzolanic reaction. The new binder had a shorter setting time and a higher early strength than the binder prepared without sFCCC

CHARACTERIZATION OF Pseudomonas syringae pv. morsprunorum ORIGINATING FROM SWEET CHERRY AND PLUM IN SERBIA

Pseudomonas strains originating from symptomatic (bacterial spot) leaf tissues of sweet cherry (Topola, Šumadija) and plum (Krušedol Selo, Srem) were isolated during 2016 and 2020, respectively. Based on the findings yielded by classical microbiological methods, LOPAT (+---+), GATTa (--++) and pathogenicity tests performed on detached fruitlets (sweet and sour cherry) and pods (bean pods), all strains were confirmed to belong to P. syringae pv. morsprunorum. The detection of cfl gene allowed strains that belong to race 1 to be identified. The DNA fingerprinting patterns obtained with four rep-PCR (BOX and ERIC), RAPD-PCR (M13), and IS50-PCR (IS50) methods revealed that the seven tested sweet cherry and plum P. s. pv. morsprunorum strains, as well as comparative KBNS71 and the reference strain CFBP 2119, were genetically heterogeneous. Conversely, MLSA based on the four-gene-based scheme (gapA, gltA, gyrB, and rpoD) indicated genetic homogeneity among all tested Serbian sweet cherry and plum strains, as well as P. s. pv. morsprunorum race 1 strains from the NCBI. Although the MLSA findings indicate that the sweet cherry and plum strains used in this study are 100% identical, as they might have different virulence genes, genome sequencing should be performed to eventually find the strain sub-clades based on the host

Difference in element accumulation and histopathology of Pontic shad (Alosa immaculata) migrants caught in the Danube River in interval of one decade

Pontic shad (Alosa immaculata) is an anadromous species that lives in the Black Sea and Sea of Azov and migrates into the Danube, Don and other rivers to spawn. It is still economically important fish species in the Danube River. As the North-Western part of the Black Sea is heavily polluted investigation was performed to determine heavy metal and element accumulation in muscle tissue of Pontic shad as well as to record the level of histopathological changes. Pontic shad specimens were caught on 863 river kilometer of the Danube and the first investigation was performed during 2007 and repeated one decade later in the period 2017-2019. Element analysis was performed by inductively-coupled plasma – optic emission spectroscopy (ICPOES). In both sampling periods, only concentrations of arsenic (As), copper (Cu), iron (Fe), magnesium (Mg), strontium (Sr), and zinc (Zn) were above detection limit. Higher concentrations of As, Cu, and Zn were detected in 2007, while higher concentrations of Fe, Mg, and Sr were measured in 2019. Differences in concentrations of these elements, between sampling periods, were statistically significant. The gills of sampled fish were assessed using histopathology as a marker of general fish health state, using semi-quantitative scoring system. The histopathological results revealed different pattern of histopathological alterations in the gills of fish sampled during two distinct time periods. According to the method used, there were no difference in total gill histopathological index, but alterations were specific for fish sampled at two time points. Hyperemia and hyperplasia of respiratory epithelium dominated in fish sampled at the year 2007, while necrosis of branchial tissue prevailed in fish sampled a decade later

The influence of dopants on anatase-rutile phase transition

Titanium dioxide exists in three different crystalline forms: anatase, rutile, and brookite. It is well known that on heating, anatase and brookite can be easily transformed to rutile which is considered as the most stable phase [1]. The aim of this study was to investigate the influence of different dopants on anatase-rutile phase transition. Doped TiO2 samples (TiO2-M, M = V, Mn, and Cu) containing 5 at% of the dopant were prepared by mixing anatase and appropriate oxide (V2O5, MnO2, and CuO) in agate mortar for 30 min. In order to determine the heat treatment conditions, TG/DTA analysis of the samples was performed. Finally, mixed powders as well as the pure anatase phase (TiO2) were heat treated at 700 °C for 3 h. XRD analysis was performed to estimate the phase composition, unit cell parameters, and crystallite sizes. Rutile was formed in all samples: 2.8 wt% in TiO2, 25.5 wt% in TiO2-Mn, 75.8 wt% in TiO2-V, and 95.2 wt% in TiO2-Cu. In TiO2- Mn, TiO2-V, and TiO2, anatase was present beside rutile, while in the case of TiO2-Cu 4.8 wt% of the unreacted CuO was found. Obtained results revealed that all the dopants accelerated anatase-rutile phase transition in the following order: Cu2+ > V5+ > Mn4+. It is well known that defects are the driving force for the anatase-rutile phase transition and since Ti4+ and Mn4+ are isovalent, no new defects were formed by incorporating Mn4+ ions into TiO2 lattice. This resulted in the least amount of rutile in TiO2-Mn comparing to TiO2-V and TiO2-Cu where new defects were probably formed. As no initial oxides were found in TiO2-Mn and TiO2-V, it can be concluded that Mn4+ and V5+ ions were incorporated into the anatase lattice. On the other hand, in the case of TiO2-Cu, even 4.8 wt% of initial CuO was found. The detected residue of CuO can be explained by the fact that the ionic radius of Cu2+ for an octahedral environment (0.870 Å) is much larger than that of Ti4+ (0.745 Å), unlike those for Mn4+ (0.670 Å) and V5+ (0.680 Å). Although almost all introduced quantity of CuO, i.e. 96 %, was found in TiO2-Cu, a small amount was surely necessary to cause the anatase-rutile phase transition. According to calculated crystallite sizes which were in the range of 55 – 90 nm, nanocrystalline samples were prepared. 1. P. I. Gouma, M. J. Mills J. Am. Ceram. Soc. 2001, 84 (3) 619–622

Explainable AI for unveiling deep learning pollen classification model based on fusion of scattered light patterns and fluorescence spectroscopy

Pollen monitoring have become data-intensive in recent years as real-time detectors are deployed to classify airborne pollen grains. Machine learning models with a focus on deep learning, have an essential role in the pollen classifcation task. Within this study we developed an explainable framework to unveil a deep learning model for pollen classifcation. Model works on data coming from single particle detector (Rapid-E) that records for each particle optical fngerprint with scattered light and laser induced fuorescence. Morphological properties of a particle are sensed with the light scattering process, while chemical properties are encoded with fuorescence spectrum and fuorescence lifetime induced by high-resolution laser. By utilizing these three data modalities, scattering, spectrum, and lifetime, deep learning-based models with millions of parameters are learned to distinguish diferent pollen classes, but a proper understanding of such a black-box model decisions demands additional methods to employ. Our study provides the frst results of applied explainable artifcial intelligence (xAI) methodology on the pollen classifcation model. Extracted knowledge on the important features that attribute to the predicting particular pollen classes is further examined from the perspective of domain knowledge and compared to available reference data on pollen sizes, shape, and laboratory spectrofuorometer measurements

Diversity of Bacterial Soft Rot-Causing Pectobacterium Species Affecting Cabbage in Serbia

The aim of this work was to identify and characterize the pectolytic bacteria responsible for the emergence of bacterial soft rot on two summer cabbage hybrids (Cheers F1 and Hippo F1) grown in the Futog locality (Baˇcka, Vojvodina), known for the five-century-long tradition of cabbage cultivation in Serbia. Symptoms manifesting as soft lesions on outer head leaves were observed during August 2021, while the inner tissues were macerated, featuring cream to black discoloration. As the affected tissue decomposed, it exuded a specific odor. Disease incidence ranged from 15% to 25%. A total of 67 isolates producing pits on crystal violet pectate (CVP) medium were characterized for their phenotypic and genotypic features. The pathogenicity was confirmed on cabbage heads. Findings yielded by the repetitive element palindromic-polymerase chain reaction (rep-PCR) technique confirmed interspecies diversity between cabbage isolates, as well as intraspecies genetic diversity within the P. carotovorum group of isolates. Based on multilocus sequence typing (MLST) using genes dnaX, mdh, icdA, and proA, five representative isolates were identified as Pectobacterium carotovorum (Cheers F1 and Hippo F1), while two were identified as Pectobacterium versatile (Hippo F1) and Pectobacterium odoriferum (Hippo F1), respectively, indicating the presence of diverse Pectobacterium species even in combined infection in the same field. Among the obtained isolates, P. carotovorum was the most prevalent species (62.69%), while P. versatile and P. odoriferum were less represented (contributing by 19.40% and 17.91%, respectively). Multilocus sequence analysis (MLSA) performed with concatenated sequences of four housekeeping genes (proA, dnaX, icdA, and mdh) and constructed a neighbor-joining phylogenetic tree enabled insight into the phylogenetic position of the Serbian cabbage Pectobacterium isolates. Bacterium P. odoriferum was found to be the most virulent species for cabbage, followed by P. versatile, while all three species had comparable virulence with respect to potato. The results obtained in this work provide a better understanding of the spreading routes and abundance of different Pectobacterium spp. in Serbia

Artificial Intelligence and Education in Serbia

Artificial intelligence (AI) has rapidly emerged as a transformative technology with potential applications in various fields, including education. With the increasing number of tools powered by AI technology and especially with the launch of the artificial intelligence-based language model, the ChatGPT, the issue of using AI has come to the center of interest for researchers in different fields, including social sciences and humanities, such as sociology, philosophy, pedagogy and religion studies, but also for students and teachers. We consider the potential of AI in education, including its ability to individualize learning, improve assessment and feedback, and enhance educational research, as well as the concerns about depersonalization of teaching, privacy, equity, quality of human interactions, and so on. Relying on the experience of education in Serbia and the UNESCO Education 2030 Agenda, we analyze the practice of using AI by teachers and students in Serbia