The impact of preparation route on the performance of silver dodecatungstophosphate/β zeolite catalysts in the ethylene production

Heteropolyacids and their salts comprise catalytic centers for the production of ethylene, one of the most important constituents in the chemical industry. The paper emphasizes different synthesis routes of hybrid materials consisting of dodecatungstophosphoric acid silver salt (AgPW) and β zeolite—stepwise wet impregnation, silver-exchange in β zeolite, and dry mixing of precursors. Composite preparation procedures induced minor effects on the weak acid sites, while strong acid sites were increased significantly. β/AgPW composites prepared by two-steps wet impregnation and ion-exchange procedures have strong acid sites content and total acidity higher in comparison to the pure AgPW salt and β zeolite. This is a result of precursors synergetic effect—cumulative strong acidic sites are generated in the presence of well-dispersed Keggin ions on the zeolite network. Composite samples with a higher content of strong acid centers exhibit higher conversion in the ethanol dehydration reaction, i.e., the ion-exchanged βAgPW sample has attained a conversion over 81%, while the wet-impregnated sample has a significant 86%. The distribution and presence of AgPW active phase are found to be crucial for both stable conversion and high selectivity results in ethylene production from ethanol, which is regarded as one of the most significant processes in environmental and sustainable industrial chemistry. Graphic abstract: [Figure not available: see fulltext.

Korelacija eksperimentalnih podataka sa teorijskim predviđanjem sorpcije jona teških metala na makroporoznom amino-funkcionalizovanom sorbentu

Over the decades, various sorbents have been used in the treatment of wastewater contaminated with heavy metal ions, which seriously endanger the living world. Macroporous functional polymers show a high affinity for sorption of these ions, where sorption efficiency and selectivity directly depend on the nature of the functional groups of sorbent and metal ions. In this study, we performed a correlation of theoretical predictions and experimental data obtained by investigation of Cu2+, Co2+, Ni2+ and Cd2+ cations sorption under competitive and uncompetitive conditions from aqueous solutions on macroporous amino-functionalized sorbent poly(glycidyl methacrylate-coethylene glycol dimethacrylate), PGME-deta. Quantum-chemical calculations estimated the binding energies of metal ions to the active sites of the sorbent, on the model systems of individual fragments, composed of metal ions and ligands, based on statistical analysis of data obtained from crystal structures. By this theoretical approach, the high degree of correlation with experimental data was observed for mono-component system.Decenijama se različiti sorbenti primenjuju za tretman otpadnih voda kontaminiranih jonima teških metala, koji ozbiljno ugrožavaju živi svet. Makroporozni funkcionalni polimeri pokazuju visok afinitet za jone teških metala, pri čemu efikasnost sorpcije i selektivnost direktno zavise od prirode funkcionalnih grupa sorbenta i jona metala. U radu je predstavljena korelacija teorijskih predviđanja i eksperimentalnih podataka dobijenih ispitivanjem sorpcije katjona Cu2+, Co2+, Ni2+ i Cd2+ u konkurentnim i nekonkurentnim uslovima u vodenom rastvoru na makroporoznom amino-funkcionalizovanom sorbentu poli(glicidil-metakrilat-co-etilen glikol dimetakrilat), PGME-deta. Kvantno-hemijskim proračunima procenjene su energije vezivanja metalnih jona za aktivna mesta sorbenta na model sistemima pojedinačnih fragmenata, metal-ligand, dobijenih statističkom analizom podataka baze kristalnih struktura. Ovakav teorijski pristup pokazao je visok stepen korelacije sa eksperimentalnim podacima u jednokomponentnim sistemima

Valorization of Winery Waste: Prokupac Grape Seed as a Source of Nutritionally Valuable Oil

Valorization of winery waste is a promising solution for waste management with additional benefit of bioactive compounds isolation. The aim of this study was to analyze the nutritional and bioactive potential of oil derived from Serbian autochthonous grape seed variety Prokupac and to compare it with known international grape varieties. Additionally, two extraction methods (ultrasound assisted extraction and cold pressing) were used in order to determine their influence on physico-chemical and nutritive characteristics of grape seed oil. Different methods, including determination of physicochemical properties, content of bioactive compounds, oxidative stability and antioxidative capacity were used for the characterization of grape seed oils. Results indicated that the higher yield was obtained by ultrasound assisted extraction compared to cold pressing. The application of ultrasound assisted extraction resulted in increased α-tocopherol content and better antioxidant capacity and oxidative stability of oil. Significant differences in bioactive composition were observed for Prokupac seed oil compared to the other grape varieties. Oil extracted from Prokupac grape seed had the lowest content of polyunsaturated and the highest content of saturated fatty acids, the highest content of α-tocopherol and consequently, the best antioxidative capacity. Prokupac grape seed has a great potential for isolation of nutritive and bioactive valuable oil

Can Zeolite-Supporting Acridines Boost Their Anticancer Performance?

Acridine and its derivatives (9-chloroacridine and 9-aminoacridine) are investigated here, supported on FAU type zeolite Y, as a delivery system of anticancer agents. FTIR/Raman spectroscopy and electron microscopy revealed successful drug loading on the zeolite surface, while spectrofluorimetry was employed for drug quantification. The effects of the tested compounds on cell viability were evaluated using in vitro methylthiazol-tetrazolium (MTT) colorimetric technique against human colorectal carcinoma (cell line HCT-116) and MRC-5 fibroblasts. Zeolite structure remained unchanged during homogeneous drug impregnation with achieved drug loadings in the 18–21 mg/g range. The highest drug release, in the µM concentration range, with favourable kinetics was established for zeolite-supported 9-aminoacridine. The acridine delivery via zeolite carrier is viewed in terms of solvation energy and zeolite adsorption sites. The cytotoxic effect of supported acridines on HCT-116 cells reveals that the zeolite carrier improves toxicity, while the highest efficiency is displayed by zeolite-impregnated 9-aminoacridine. The 9-aminoacridine delivery via zeolite carrier favours healthy tissue preservation while accompanying increased toxicity toward cancer cells. Cytotoxicity results are well correlated with theoretical modelling and release study, providing promising results for applicative purposes

Consensus recommendations for the diagnosis, treatment and follow-up of inherited methylation disorders

Inherited methylation disorders are a group of rarely reported, probably largely underdiagnosed disorders affecting transmethylation processes in the metabolic pathway between methionine and homocysteine. These are methionine adenosyltransferase I/III, glycine N-methyltransferase, S-adenosylhomocysteine hydrolase and adenosine kinase deficiencies. This paper provides the first consensus recommendations for the diagnosis and management of methylation disorders. Following search of the literature and evaluation according to the SIGN-methodology of all reported patients with methylation defects, graded recommendations are provided in a structured way comprising diagnosis (clinical presentation, biochemical abnormalities, differential diagnosis, newborn screening, prenatal diagnosis), therapy and follow-up. Methylation disorders predominantly affect the liver, central nervous system and muscles, but clinical presentation can vary considerably between and within disorders. Although isolated hypermethioninemia is the biochemical hallmark of this group of disorders, it is not always present, especially in early infancy. Plasma S-adenosylmethionine and S-adenosylhomocysteine are key metabolites for the biochemical clarification of isolated hypermethioninemia. Mild hyperhomocysteinemia can be present in all methylation disorders. Methylation disorders do not qualify as primary targets of newborn screening. A low-methionine diet can be beneficial in patients with methionine adenosyltransferase I/III deficiency if plasma methionine concentrations exceed 800 μmol/L. There is some evidence that this diet may also be beneficial in patients with S-adenosylhomocysteine hydrolase and adenosine kinase deficiencies. S-adenosylmethionine supplementation may be useful in patients with methionine adenosyltransferase I/III deficiency. Recommendations given in this article are based on general principles and in practice should be adjusted individually according to patient's age, severity of the disease, clinical and laboratory findings

Nutritive characteristics and antioxidant activity of pseudograins

Amaranth (Amaranthus sp., Amaranthaceae), quinoa (Chenopodium quinoa, Amaranthaceae) and canihua (Chenopodium pallidicaule, Amaranthaceae) are pseudograins originating from South America. They are widely used in the diet as well as chia seeds (Salvia hispanica, Lamiaceae) from South America and wheat (Triticum aestivum, Poaceae) and millet (Panicum miliaceum, Poaceae), characteristic for our climate. The aim of the study was to determine the nutritive characteristics, phenolic content and antioxidant activity of commercial samples of pseudograins (аmaranth, quinoa and canihua) from our market, as well as a comparative analysis to chia seeds, common and khorasan wheat and millet. Basic nutritive value parameters and mineral contents were assessed for pseudograins and chia seeds. The content of total phenolic compounds (TPC) and total flavonoid compounds (TFC), antioxidant activity by DPPH and FRAP tests were determined for all samples. The results of the nutrient composition indicates that analyzed pseudograins are good sources of proteins (13.39%) and unlike chia seeds are characterized by relatively low fat content (5.97%). Analyzed pseudograins contain calcium, magnesium, zinc and iron in a significant amount. The highest TPC content was observed in chia seeds (395.7 mg GAE/100 g), following canihua (327.4 mg GAE/100 g), quinoa (161.9 mg GAE/100 g), common wheat (61.8 mg GAE/100 g), Khorasan wheat (51.1 mg GAE/100 g), while the lowest content was identified in millet (32.9 mg GAE/100 mg). TFC content was in a range from 0.001 % (common wheat, khorasan wheat) to 0.099 % (canihua). Antioxidant properties of pseudograins were lower compared to chia seeds, but similar to common wheat and khorasan wheat while even higher comparing to millet.X International Scientific Agriculture Symposium "Agrosym 2019", Jahorina, Bosnia and Herzegovina, October 03 - 06, 2019Saopštenje sa međunarodnog skupa štampano u celini (kategorija M33

Efficacy of biological agents in control of pepper bacterial spot

Bakteriozna pegavost lišća koju izaziva Xanthomonas euvesicatoria je jedno od najznačajnih oboljenja paprike u Srbiji. U cilju zaštite paprike, korišćeni su biološki preparati Serenade ASO, Erwix, Bakterije, Ekstrasol i Bacillomix. Kao standard korišćen je preparat na bazi bakar-hidroksida (Everest). Ogled je postavljen u Institutu za povrtarstvo u Smederevskoj Palanci tokom leta 2023. godine. Proučavanja su obavljena na sorti paprike Paraćinka u uslovima veštačke inokulacije u stakleniku. Najefikasniji je bio preparat na bazi bakar-hidroksida (96%), dok su biološki preparati ispoljili nižu efikasnost: Serenade ASO (71%), Bakterije (61%), Ekstrasol (61%), Erwix (55%) i Bacillomix (54%). Ipak, svi proučavani tretmani su značajno smanjili intenzitet oboljenja u odnosu na kontrolu. Eksperiment je izveden u stakleniku bez klimatizacije, pri visokim spoljnim temperaturama, što je moglo nepovoljno uticati na efikasnost preparata baziranih na biološkim agensima. Prilikom narednih ogleda neophodno je obezbediti kontrolisane uslove. Treba isprobati i različito vreme primene i integraciju sa drugim merama zaštite.Bacterial spot caused by Xanthomonas euvesicatoria is one of the most important pepper diseases in Serbia. In order to control this disease, we tested efficacy of commercially available biological products: Serenade ASO, Erwix, Bakterije, Ekstrasol and Bacillomix. A preparation based on copper hydroxide (Everest) was used as a standard treatment. The experiment was set up at the Institute for Vegetable Crops in Smederevska Palanka during the summer of 2023. Experiment was performed on pepper variety Paraćinka under artificial inoculation in a greenhouse. The most efficient was the standard treatment based on copper hydroxide (96%), while tested biocontrol treatments showed statistically lower efficacy: Serenade ASO (71%), Bacteria (61%), Ekstrasol (61%), Erwix (55%) and Bacillomix (54%). However, all tested treatments significantly reduced intensity of the disease compared to the control. The experiment was performed in a nonclimatized greenhouse, which could adversely affect the effectiveness of biocontrol treatments. Therefore, subsequent trials, should be carried out in controlled conditions. Different application times and integration with other protection measures should also be tested

Efficacy of biological agents in control of pepper bacterial spot

Bakteriozna pegavost lišća koju izaziva Xanthomonas euvesicatoria je jedno od najznačajnih oboljenja paprike u Srbiji. U cilju zaštite paprike, korišćeni su biološki preparati Serenade ASO, Erwix, Bakterije, Ekstrasol i Bacillomix. Kao standard korišćen je preparat na bazi bakar-hidroksida (Everest). Ogled je postavljen u Institutu za povrtarstvo u Smederevskoj Palanci tokom leta 2023. godine. Proučavanja su obavljena na sorti paprike Paraćinka u uslovima veštačke inokulacije u stakleniku. Najefikasniji je bio preparat na bazi bakar-hidroksida (96%), dok su biološki preparati ispoljili nižu efikasnost: Serenade ASO (71%), Bakterije (61%), Ekstrasol (61%), Erwix (55%) i Bacillomix (54%). Ipak, svi proučavani tretmani su značajno smanjili intenzitet oboljenja u odnosu na kontrolu. Eksperiment je izveden u stakleniku bez klimatizacije, pri visokim spoljnim temperaturama, što je moglo nepovoljno uticati na efikasnost preparata baziranih na biološkim agensima. Prilikom narednih ogleda neophodno je obezbediti kontrolisane uslove. Treba isprobati i različito vreme primene i integraciju sa drugim merama zaštite.Bacterial spot caused by Xanthomonas euvesicatoria is one of the most important pepper diseases in Serbia. In order to control this disease, we tested efficacy of commercially available biological products: Serenade ASO, Erwix, Bakterije, Ekstrasol and Bacillomix. A preparation based on copper hydroxide (Everest) was used as a standard treatment. The experiment was set up at the Institute for Vegetable Crops in Smederevska Palanka during the summer of 2023. Experiment was performed on pepper variety Paraćinka under artificial inoculation in a greenhouse. The most efficient was the standard treatment based on copper hydroxide (96%), while tested biocontrol treatments showed statistically lower efficacy: Serenade ASO (71%), Bacteria (61%), Ekstrasol (61%), Erwix (55%) and Bacillomix (54%). However, all tested treatments significantly reduced intensity of the disease compared to the control. The experiment was performed in a nonclimatized greenhouse, which could adversely affect the effectiveness of biocontrol treatments. Therefore, subsequent trials, should be carried out in controlled conditions. Different application times and integration with other protection measures should also be tested

LIMITATIONS IN THE APPLICATION OF THE ONLINE MODEL OF EDUCATION IN PRIMARY SCHOOLS IN SERBIA

Given that the 4th Industrial Revolution encompasses not only the private but also the public sector, including the educational system also, all the educational institutions strive to be digitally transformed to the extent it is possible. Also, the COVID-19 period of time conditioned them to implement an online model of education without much time for the transition process. Also, there is an indication that the education system, in general, will move towards a combined (online and onsite) model in the future, as a response to new trends in Industry 4.0 era. Thus, the aim of this paper is to identify crucial limitations in the application of the online model of education for both teachers and pupils. The sample size is 166 respondents. The research instrument is the questionnaire that includes an evaluation of potential limitations in the application of the online model of education in primary schools in Serbia. The results could be used to give an adequate insight for decision-makers in this area

Correlation of experimental data and theoretical predictions of heavy metal sorption by macroporous amino-functionalized sorbent

Decenijama se različiti sorbenti primenjuju za tretman otpadnih voda kontaminiranih jonima teških metala, koji ozbiljno ugrožavaju živi svet. Makroporozni funkcionalni polimeri pokazuju visok afinitet za jone teških metala, pri čemu efikasnost sorpcije i selektivnost direktno zavise od prirode funkcionalnih grupa sorbenta i jona metala. U radu je predstavljena korelacija teorijskih predviđanja i eksperimentalnih podataka dobijenih ispitivanjem sorpcije katjona Cu2+, Co2+, Ni2+ i Cd2+ u konkurentnim i nekonkurentnim uslovima u vodenom rastvoru na makroporoznom aminofunkcionalizovanom sorbentu poli(glicidil-metakrilat-co-etilen glikol dimetakrilat), PGME-deta. Kvantno-hemijskim proračunima procenjene su energije vezivanja metalnih jona za aktivna mesta sorbenta na model sistemima pojedinačnih fragmenata, metal-ligand, dobijenih statističkom analizom podataka baze kristalnih struktura. Ovakav teorijski pristup pokazao je visok stepen korelacije sa eksperimentalnim podacima u jednokomponentnim sistemima.Over the decades, various sorbents have been used in the treatment of wastewater contaminated with heavy metal ions, which seriously endanger the living world. Macroporous functional polymers show a high affinity for sorption of these ions, where sorption efficiency and selectivity directly depend on the nature of the functional groups of sorbent and metal ions. In this study, we performed a correlation of theoretical predictions and experimental data obtained by investigation of Cu2+ , Co2+, Ni2+ and Cd2+ cations sorption under competitive and uncompetitive conditions from aqueous solutions on macroporous amino-functionalized sorbent poly(glycidyl methacrylate-coethylene glycol dimethacrylate), PGME-deta. Quantum-chemical calculations estimated the binding energies of metal ions to the active sites of the sorbent, on the model systems of individual fragments, composed of metal ions and ligands, based on statistical analysis of data obtained from crystal structures. By this theoretical approach, the high degree of correlation with experimental data was observed for mono-component system