Kinetics of adsorption and hydrodynamic cavitation removal of phenol from wastewater

На основу добијених резултата утврђено је да зеолит типа силикалит селективно адсорбује фенол из водених раствора и да је адсорпција фенола на силикалиту спонтани, егзотермни, термички активирани процес. Брзина адсорпције фенола на силикалиту је кинетички ограничена брзином раста адсорпционог слоја. Кинетика адсорпције фенола може се описати моделом - реакција контролисана брзином померањa површине граничне фазе. Утврђено је да је енергија активације за адсорпцију фенола независна од степена адсорпције фенола. Предложен је нови модел за кинетику адсорпције полутаната из њихових водених раствора на зеолитима који се успешно примењује за темељно објашњење испитиване адсорпције фенола на зеолиту типа силикалит. Конструисан је кавитатор типа плоча са отворима и кавитатор Вентуријевог типа. Одређене су вредности оптималних реакционих параметара кавитационог уклањања фенола из отпадних вода укључујући температуру, концентрацију водоник пероксида, вредности кавитационог броја и pH вредност. Утврђено је да технологија хидродинамичке кавитације без додатних хемикалија омогућава да се постигне ограничени степен уклањања фенола. Повећање температуре и концентрације водоник пероксида, као и смањење вредности кавитационог броја и pH вредности раствора доводи до повећања степена уклањања фенола. Потпуно уклањање фенола из раствора се постиже у веома кратком временском интервалу за одређени стехиометријски однос водоник пероксида и фенола у реакционом раствору. Кинетика уклањања фенола у условима хидродинамичке кавитације са кавитатором оба типа може се описати кинетичким моделом хемијске реакције првог реда у односу на водоник пероксид.Based on the obtained results it was found that zeolite type silicalite adsorbs phenol from aqueous solutions selectively and that adsorption of phenol on silicalite is a spontaneous, exothermic, thermally activated process. The rate of adsorption of phenol on silicalite is kinetically limited with the increase in the rate of adsorption layer. The kinetics of phenol adsorption can be described by the model, known as - a reaction controlled by the rate of movement of the area of boundary phase. It was found that the activation energy for phenol adsorption is independent on the degree of phenol adsorption. A new model has been proposed for the kinetics of adsorption of pollutants from their aqueous solutions on zeolites, which has been successfully applied to thoroughly explain the investigated adsorption of phenols on zeolite type silicalite. A novel model for the kinetics of adsorption of pollutants from their aqueous solutions on zeolites was proposed, which is successfully applied to give comprehensive explanation of the investigated adsorption of phenol on zeolite type silicalite. Both cavitators orifice plates and Ventury type cavitator were constructed. The values of the optimal reaction parameters for phenol removal by using cavitation from waste water that include temperature, hydrogen peroxide concentration, cavitation number and pH, were determined. It has been found that hydrodynamic cavitation technology without additional use of chemicals enables to achieve a limited degree of phenol reduction. The increase in temperature and in the concentration of hydrogen peroxide, as well as the decrease in the value of the cavitation number and the pH values of the solution, leads to the increase in the in the degree of phenol removal. The complete reduction of phenol from solution is achieved in a very short time interval for the certain stoichiometric ratio of hydrogen peroxide to phenol in the reaction solution. The kinetics of phenol removal under the conditions of hydrodynamic cavitation using both types of cavitators can be described with a first-order kinetic chemical model calculated against the concentration of hydrogen peroxide..

NUTRITIVNI ZBROJ (CONTROLLING NUTRITIONAL STATUS - CONUT) MOŽE PREDVIDJETI PREŽIVLJENJE BOLESNIKA NA HEMODIJALIZI

Malnutrition causes substantial morbidity in maintenance hemodialysis (HD) patients. The Controlling Nutritional Status (CONUT) has emerged as a simple and an easily obtainable tool to comprehensively assess nutrition as it consists of serum albumin levels, absolute lymphocyte counts, and total cholesterol levels. The CONUT has been shown to predict overall survival (OS) in peritoneal dialysis patients. This study investigated whether CONUT might also predict OS in maintenance HD patients. Clinical and laboratory data were retrospectively collected. Survival time was calculated from the fi rst HD until death or last follow-up; survival analyses were performed using the methods of Kaplan-Meier and Cox regression analysis. Eighty-nine patients were included; mean age was 65.76 years (±14), 35 (39.3%) were female, and the mean CONUT was 3. Higher CONUT score correlated with lower low-density liproprotein, higher serum creatinine, higher serum C-reactive protein and higher neutrophil-to-lymphocyte ratio, as well as with a higher incidence of nephrotic proteinuria (p<0.050 for all analyses). Univariately, patients with higher CONUT (≥5) had an inferior OS (median 54 vs. 112 months, HR 2.27; p=0.013). In the Cox regression analysis, higher CONUT remained independently associated with inferior OS (HR 9.50; p=0.002) when adjusted to age, sex, diabetes mellitus and nephrotic proteinuria. Therefore, the CONUT score might identify HD patients at an increased risk of death; however, future studies are needed to elucidate whether CONUT score might be able to guide nutritional support in HD patients.Pothranjenost uzrokuje značajan pobol i smrtnost bolesnika na hemodijalizi (HD). Controlling Nutritional Status (CONUT) je jednostavan nutritivni zbroj koji cjelovito procjenjuje uhranjenost, a sastoji se od serumske koncentracije albumina, apsolutnog broja limfocita i koncentracije serumskog kolesterola. Ova unicentrična retrospektivna studija analizirala je prediktivnu sposobnost zbroja CONUT da procijeni preživljenje bolesnika na HD. Ukupno preživljenje mjereno je kao vrijeme od prve HD do smrti ili posljednjeg pregleda bolesnika, a krivulje preživljenja uspoređene su Kaplan-Meirovom metodom, dok je Coxova regresijska metoda primijenjena u multivarijatnim analizama. Uključeno je 89 bolesnika, od toga 35 (39,3 %) žena; srednja dob bila je 65,76 godina (±14). Srednji zbroj CONUT bio je 3. Viši zbroj CONUT korelirao je s nižim koncentracijama serumskog lipoproteina niske gustoće, višim serumskim kreatininom, višim serumskim C-reaktivnim proteinom i višim omjerom neutrofi la/limfocita, kao i s većom učestalošću nefrotske proteinurije (p<0,050 za sve analize). U univarijatnoj analizi je viši zbroj CONUT (≥5) bio povezan s lošijim preživljenjem (medijan 54 prema 112 mjeseci, HR 2,27; p=0,013). U multivarijatnoj Coxovoj regresijskoj analizi je viši CONUT ostao nezavisno povezan s lošijim preživljenjem (HR 9,50; p=0,002) kada je bio ispravljen za dob, spol, šećernu bolest i nefrotsku proteinuriju. Zaključno, zbroj CONUT može identifi cirati bolesnike na HD s povišenim rizikom od smrti. Potrebne su dodatna istraživanja kako bi se analizirala sposobnost zbroja CONUT da usmjeri nutritivnu potporu u bolesnika na HD

Modeling of Impurities Evaporation Reaction Order in Aluminum Alloys by the Parametric Fitting of the Logistic Function

Advancements in computer capabilities enable predicting process outcomes that earlier could only be assessed after post-process analyses. In aerospace and automotive industries it is important to predict parts properties before their formation from liquid alloys. In this work, the logistic function was used to predict the evaporation rates of the most detrimental impurities, if the temperature of the liquid aluminum alloy was known. Then, parameters of the logistic function were used to determine the transition points where the reaction order was changing. Samples were heated to 610 °C, 660 °C, 710 °C, and 760 °C for one hour, after which the chemical analyses were performed and evaporation rates were calculated for Cd, Hg, Pb and Zn elements. The pressure inside the encapsulated area was maintained at 0.97 kPa. Whereas parameters that define the evaporation rate increase with the temperature increase, the maximum evaporation rates were deduced from the experimental data and fitted into the logistic function. The elemental evaporation in liquid-aluminum alloys is the best defined by the logistic function, since transitions from the first to zero-order-governed evaporation reactions have nonsymmetrical evaporation rate slopes between the lowest and the highest evaporation rate point

LncRNAs as Regulators of Atherosclerotic Plaque Stability

Current clinical data show that, despite constant efforts to develop novel therapies and clinical approaches, atherosclerotic cardiovascular diseases (ASCVD) are still one of the leading causes of death worldwide. Advanced and unstable atherosclerotic plaques most often trigger acute coronary events that can lead to fatal outcomes. However, despite the fact that different plaque phenotypes may require different treatments, current approaches to prognosis, diagnosis, and classification of acute coronary syndrome do not consider the diversity of plaque phenotypes. Long non-coding RNAs (lncRNAs) represent an important class of molecules that are implicated in epigenetic control of numerous cellular processes. Here we review the latest knowledge about lncRNAs’ influence on plaque development and stability through regulation of immune response, lipid metabolism, extracellular matrix remodelling, endothelial cell function, and vascular smooth muscle function, with special emphasis on pro-atherogenic and anti-atherogenic lncRNA functions. In addition, we present current challenges in the research of lncRNAs’ role in atherosclerosis and translation of the findings from animal models to humans. Finally, we present the directions for future lncRNA-oriented research, which may ultimately result in patient-oriented therapeutic strategies for ASCVD

Supplementary data for the article: Andrejević, T. P.; Nikolić, A. M.; Glišić, B. Đ.; Wadepohl, H.; Vojnovic, S.; Zlatović, M.; Petković, M.; Nikodinovic-Runic, J.; Opsenica, I. M.; Djuran, M. I. Synthesis, Structural Characterization and Antimicrobial Activity of Silver(I) Complexes with 1-Benzyl-1H-Tetrazoles. Polyhedron 2018, 154, 325–333. https://doi.org/10.1016/j.poly.2018.08.001

Supplementary data for: [https://doi.org/10.1016/j.poly.2018.08.001]Research data for this article: [https://www.ccdc.cam.ac.uk/structures/search?id=doi:10.5517/ccdc.csd.cc2046ft&sid=DataCite]Research data for this article: [https://www.ccdc.cam.ac.uk/structures/search?id=doi:10.5517/ccdc.csd.cc2046gv&sid=DataCite]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2228]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2991

Synthesis, structural characterization and antimicrobial activity of silver(I) complexes with 1-benzyl-1H-tetrazoles

Herein, we report the synthesis and structural characteristics of three tetrazole-containing compounds, 1-benzyl-1H-tetrazole (bntz), 1-benzyl-1H-tetrazol-5-amine (bntza) and 1-(4-methoxybenzyl)-1H-tetrazol-5-amine (mbntza) and the corresponding silver(I) complexes of the general formula [Ag(NO3-O)(L-N4)(2)](n), L = bntz (1), bntza (2) and mbntza (3). Silver(I) complexes 1-3 and 1-benzyl-1H-tetrazoles have been studied in detail by NMR, IR and UV-Vis spectroscopic methods and the structures of 1 and 2 have been determined by single-crystal X-ray diffraction analysis. The results of these analyses revealed a monodentate coordination of the ligands to Ag(I) ion via the N4 tetrazole nitrogen. The antimicrobial potential of silver(I) complexes 1-3 was evaluated against the broad panel of Gram-positive and Gram-negative bacteria and fungi, displaying their remarkable inhibiting activity with MIC (minimal inhibitory concentration) values in the range 2-8 and 0.16-1.25 mu g/mL (3.8-16.3 and 0.31-2.15 mu M), respectively. On the other hand, 1-benzyl-1H-tetrazoles used for the synthesis of the silver(I) complexes were not active against the investigated strains, suggesting that the activity of the complexes originates from the Ag(I) ion exclusively. Moreover, silver(I) complexes 1-3 have good therapeutic potential, which can be deduced from their moderate cytotoxicity on the human fibroblast cell line MRC5, with IC50 values falling in the range 30-60 mu g/mL (57.7-103.4 mu M).Related to published version: [https://imagine.imgge.bg.ac.rs/handle/123456789/1144]This is the peer-reviewed version of the article: Andrejević, T. P., Nikolić, A. M., Glišić, B., Wadepohl, H., Vojnović, S., Zlatović, M., Petković, M., Nikodinović-Runić, J., Opsenica, I. M., & Djuran, M. (2018). Synthesis, structural characterization and antimicrobial activity of silver(I) complexes with 1-benzyl-1H-tetrazoles. Polyhedron, 154, 325–333. [https://doi.org/10.1016/j.poly.2018.08.001

Supplementary data for the article: Andrejević, T. P.; Nikolić, A. M.; Glišić, B. Đ.; Wadepohl, H.; Vojnovic, S.; Zlatović, M.; Petković, M.; Nikodinovic-Runic, J.; Opsenica, I. M.; Djuran, M. I. Synthesis, Structural Characterization and Antimicrobial Activity of Silver(I) Complexes with 1-Benzyl-1H-Tetrazoles. Polyhedron 2018, 154, 325–333. https://doi.org/10.1016/j.poly.2018.08.001

Supplementary data for: [https://doi.org/10.1016/j.poly.2018.08.001]Research data for this article: [https://www.ccdc.cam.ac.uk/structures/search?id=doi:10.5517/ccdc.csd.cc2046ft&sid=DataCite]Research data for this article: [https://www.ccdc.cam.ac.uk/structures/search?id=doi:10.5517/ccdc.csd.cc2046gv&sid=DataCite]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2228]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2991

Syntactic Terminology in School Discourse

Tema je ovoga završnog rada sintaktičko nazivlje u školskom diskursu. Nazivlje se promatralo u kategoriji predikata i subjekta, samostalnih rečeničnih članova. Cilj je rada upozoriti na razlike u sintaktičkom nazivlju koje su zastupljene u literaturi namijenjenoj obrazovanju kako nebi došlo do poteškoća pri stjecanju novih znanja zbog neujednačenosti nazivlja. Najprije je citirana definicija sintakse kako bi se objasnio taj termin. Istaknute su vrste samoznačnih i suznačnih riječi, kao i samostalni i nesamostalni rečenični članovi. Nadalje, kategorije predikata i subjekta analizirane su na temelju udžbenika za peti i sedmi razred osnovne škole te udžbenika za treći razred srednje škole za gimnaziju i strukovnu (četverogodišnju) školu. U analizu su uključene i suvremene gramatike hrvatskoga standardnog jezika. Nakon proučene nabrojene literature moguće je zaključiti kako je nazivlje u školskom diskursu većinom ujednačeno, ali su navedene razlike koje se odnose na sadržaj nastavnog plana i programa te namjenu gramatika

Syntactic Terminology in School Discourse

Tema je ovoga završnog rada sintaktičko nazivlje u školskom diskursu. Nazivlje se promatralo u kategoriji predikata i subjekta, samostalnih rečeničnih članova. Cilj je rada upozoriti na razlike u sintaktičkom nazivlju koje su zastupljene u literaturi namijenjenoj obrazovanju kako nebi došlo do poteškoća pri stjecanju novih znanja zbog neujednačenosti nazivlja. Najprije je citirana definicija sintakse kako bi se objasnio taj termin. Istaknute su vrste samoznačnih i suznačnih riječi, kao i samostalni i nesamostalni rečenični članovi. Nadalje, kategorije predikata i subjekta analizirane su na temelju udžbenika za peti i sedmi razred osnovne škole te udžbenika za treći razred srednje škole za gimnaziju i strukovnu (četverogodišnju) školu. U analizu su uključene i suvremene gramatike hrvatskoga standardnog jezika. Nakon proučene nabrojene literature moguće je zaključiti kako je nazivlje u školskom diskursu većinom ujednačeno, ali su navedene razlike koje se odnose na sadržaj nastavnog plana i programa te namjenu gramatika