Cobalt(II) chloride and bromide complex formation in electrical unsymmetric aqueous molten salts

U ovoj doktorskoj disertaciji proučavano je građenje kompleksa kobalta(II) sa hloridnim i  bromidnim jonima u vodenim rastopima tipa xCa(NO3)2·zH2O – (1-x)NH4NO3 pri različitom sastavu soli (x= 0,3 – 0,9), različitom sadržaju vode (z= 2,67 – 6,67) i na različitim temperaturama (45, 55 i 65oC). Istraživanja su imala za cilj proučavanje reakcije građenja kompleksa kobalta(II) sa hloridnim i bromidnim jonima u vodenim rastopima xCa(NO3)2·zH2O – (1–x)NH4NO3,  uticaja temperature, sastava elektrolita i sadržaja vode na proces kompleksiranja, kao i određivanje termodinamičkih parametara koji karakterišu reakcije asocijacije u ovim sistemima. Ovakvi rastopi soli su posebno interesantni zbog svoje niske tačke topljenja i visoke latentne toplote topljenja pa se mogu koristiti kao fazno-promenljivi materijali za skladištenje toplotne energije.In this thesis absorption spectra of cobalt(II) chloride and bromide in calcium nitrate – ammonium nitrate – water system of the composition  xCa(NO3)2·zH2O – (1–x)NH4NO3 (x= 0.30 - 0.90 and z= 2.67 – 6.67) have been investigated in the wavelength range 400-800 nm at three different temperatures: 45, 55 and 65oC. Temparature, composition of the melt and water content influence on complex formation reactions between cobalt(II) and halide ions in aqueous xCa(NO3)2·zH2O – (1–x)NH4NO3 melts have been studied. Thermodynamic parameters for cobalt(II) – halide association process in different solvents also were determined. Investigated systems are interesting because of their high values of latent heat of fusion and low melting points. Due to these reasons, some melts are proposed for  heat energy storage materials, usually known as phase change materials (PCM)

Cobalt(II) chloride and bromide complex formation in electrical unsymmetric aqueous molten salts

U ovoj doktorskoj disertaciji proučavano je građenje kompleksa kobalta(II) sa hloridnim i  bromidnim jonima u vodenim rastopima tipa xCa(NO3)2·zH2O – (1-x)NH4NO3 pri različitom sastavu soli (x= 0,3 – 0,9), različitom sadržaju vode (z= 2,67 – 6,67) i na različitim temperaturama (45, 55 i 65oC). Istraživanja su imala za cilj proučavanje reakcije građenja kompleksa kobalta(II) sa hloridnim i bromidnim jonima u vodenim rastopima xCa(NO3)2·zH2O – (1–x)NH4NO3,  uticaja temperature, sastava elektrolita i sadržaja vode na proces kompleksiranja, kao i određivanje termodinamičkih parametara koji karakterišu reakcije asocijacije u ovim sistemima. Ovakvi rastopi soli su posebno interesantni zbog svoje niske tačke topljenja i visoke latentne toplote topljenja pa se mogu koristiti kao fazno-promenljivi materijali za skladištenje toplotne energije.In this thesis absorption spectra of cobalt(II) chloride and bromide in calcium nitrate – ammonium nitrate – water system of the composition  xCa(NO3)2·zH2O – (1–x)NH4NO3 (x= 0.30 - 0.90 and z= 2.67 – 6.67) have been investigated in the wavelength range 400-800 nm at three different temperatures: 45, 55 and 65oC. Temparature, composition of the melt and water content influence on complex formation reactions between cobalt(II) and halide ions in aqueous xCa(NO3)2·zH2O – (1–x)NH4NO3 melts have been studied. Thermodynamic parameters for cobalt(II) – halide association process in different solvents also were determined. Investigated systems are interesting because of their high values of latent heat of fusion and low melting points. Due to these reasons, some melts are proposed for  heat energy storage materials, usually known as phase change materials (PCM)

The effect of standarddose wintertime vitamin D supplementation on influenza infection in immunized nursing home elderly residents

Aim To investigate whether three-month oral vitamin D supplementation (800 IU in drops) reduces the risk of in - fluenza infection in elderly nursing home residents vacci - nated against influenza. Methods This cross-sectional observational study enrolled 97 participants (73.2% women) who received one dose of seasonal trivalent 2016-2017 influenza vaccine. The patients were randomized into an experimental group, which re - ceived vitamin D supplementation for three months start - ing on the day of vaccination, and a control group, which did not receive vitamin D supplementation. The primary outcome was the number of influenza infections labora - tory-confirmed using a rapid point-of-care test based on nasal swabs collected during vitamin D supplementation. The secondary outcome was serum 25-hydroxyvitamin D level at the end of the study. Results The mean age ±standard deviation was 78.5± 8.8 years. All participants had vitamin D deficiency at baseline. Twenty-three participants who developed signs of respira - tory infections during the study were tested for influenza virus. Although the number of influenza-positive partici - pants was lower in the group receiving vitamin D supple - mentation as compared with the control group (5 vs 12), this difference was not significant. Vitamin D supplemen - tation failed to increase 25(OH)D levels after three months of supplementation. Conclusion Elderly nursing home residents in Zagreb County have a significant vitamin D deficiency. The recom - mended national supplementation of 800 IU daily failed to lead to vitamin D sufficiency and did not reduce the risk of influenza infection among the vaccinated elderly

Antifungal activities of ionic liquids against phytopathogenic Alternaria spp. strains

A modern sustainable approach in agricultural practice would be a replacement of synthetic and toxic substances in the treatment of crop with benign and environmentally friendly compounds, by using principles of green chemistry. One of the possible directions could be using of ionic liquids (ILs), salts with melting points below 100 °C, which are well-known for manifesting antimicrobial activity. ILs can be used in the development of novel sources of antimicrobial agents such as antiseptics, biocides and antifungal agents. Furthermore, ILs have already been reported as alternative ‘green’ solvents for a wide range of reactions and technological processes. Considering the importance of research in the area of bioactivity of ILs for discovery of new green ILs for diff erent purposes, the aim of this study was to examine antifungal activity of nine newly synthesized ILs against phytopathogenic Alternaria strains isolated from from rice (A. padwickii), carrot (A. dauci) and linseed (A. linicola). Antifungal eff ect was estimated by micro-plate microdilution method for establishing minimum inhibitory (MIC) and minimum fungicidal concentration (MFC). All ionic liquids showed strain specifi c but good antifungal activity on Alternaria strains with MIC and MFC detected at the range from 9.23 mg/ml to 75.89 mg/ml. Only in case of the 1-(4-hydroxy-2-oxy)butyl -3-methylimidazolium chloride [OHC2OC2mIm][Cl], no antifungal eff ect on A. dauci were observed. Comparing to A. padwickii and A. dauci., A. linicola showed higher sensitivity to all tested ILs. Th e obtained results indicate the possibility of usage of ILs in biocontrol of plant diseases, representing their application in crop protection. However, further research is necessary in order to examine their toxicity and biodegradability in the environment

Strumalni karcinoid jajnika: prikaz dvaju slučajeva

Primary carcinoid tumors of the ovary account for 5% of ovarian teratomas. They are frequently components of mature cystic teratomas or, less commonly, mucinous cystadenomas. Most tumors are seen in peri- or postmenopausal women with symptoms of enlarging mass, or are incidental findings. Microscopically, there are four major variants of ovarian teratomas of carcinoid type: insular, trabecular, strumal and mucinous. One-third of patients with the insular type of carcinoids have symptoms of the carcinoid syndrome. Strumal carcinoid is an unusual form of ovarian teratoma composed of an intimate admixture of thyroid and carcinoid tissues that vary in their relative proportions. Two patients with ovarian tumors showing typical morphology of primary ovarian strumal carcinoid are described.Primarni karcinoidi jajnika čine 5% svih teratoma jajnika. Najčešće se nalaze kao komponenta zrelog cističnog teratoma jajnika, a rjeđe kao komponenta mucinoznog cistadenoma. Najčešće se pojavljuju u peri- ili postmenopauzalnih žena sa simptomima tumora male zdjelice ili su slučajan klinički nalaz. Histološki se razlikuje četiri glavna tipa karcinoidnih tumora jajnika: inzularni, trabekularni, strumalni i mucinozni tip. Jedna trećina bolesnica s inzularnim tipom karcinoida ima simptome karcinoidnog sindroma. Strumalni karcinoid je rijetka varijanta teratoma jajnika koji se sastoji od različitog udjela tkiva štitnjače i tkiva karcinoidnog tumora. Ovdje se prikazuju dvije bolesnice s tumorima jajnika koji pokazuju karakterističnu građu primarnih strumalnih karcinoida

Valorization of expired energydrinks by designed and integrated ionic liquid-based aqueous biphasic systems

Expired energy drinks are rich in bioactive value-added compounds that can be recovered and reused in order to valorize food waste within a circular economy perspective. However, to accomplish such requirements, it is necessary to develop sustainable extraction and recovery processes, which must consist of decreasing the number of steps required or developing integrated strategies. In this work, novel aqueous biphasic systems (ABS) composed of ionic liquids (ILs) and a biocompatible polymer polypropylene glycol (400 g·mol-1, PPG 400) were studied for the simultaneous extraction and recovery of three value-added compounds, namely, caffeine, taurine, and niacin, from expired energy drinks. ILs were designed and synthesized in order to have similar anions to the target compounds, thus allowing enhanced selectivity and biological activity, while avoiding an extra step of separation of these high-value compounds from the IL-rich phase. To this end, cholinium-based ILs comprising the anions lactate, pyruvate, taurate, and nicotinate were synthesized, and their cytotoxicity and ecotoxicity credentials were evaluated. Overall, taurine and niacin are majorly enriched in the IL-rich phase, while caffeine preferentially migrates in the majority of the cases toward the PPG-rich phase. However, caffeine also partitions to the IL-rich phase in the ABS formed by cholinium pyruvate or cholinium nicotinate. The ABS formed by cholinium nicotinate and PPG 400 is the best system identified, allowing the almost complete recovery (recovery efficiencies > 82%) of all target compounds into the IL-rich phase in one step. Furthermore, cholinium nicotinate exhibits marginal cytotoxic potential and is harmless from an ecotoxicological point of view. This system is thus a promising platform to simultaneously extract, recover, and reuse value-added compounds from expired energy drinks without the need of removing the IL or recovering the target compounds from the IL-rich phase, thus contributing to a sustainable and circular food economypublishe

Thermo-Analytical and Compatibility Study with Mechanistic Explanation of Degradation Kinetics of Ambroxol Hydrochloride Tablets under Non-Isothermal Conditions

Ambroxol hydrochloride (AMB), used as a broncho secretolytic and an expectorant drug, is a semi-synthetic derivative of vasicine obtained from the Indian shrub Adhatoda vasica. It is a metabolic product of bromhexine. The paper provides comprehensive and detailed research on ambroxol hydrochloride, gives information on thermal stability, the mechanism of AMB degradation, and data of practical interest for optimization of formulation that contains AMB as an active compound. Investigation on pure AMB and in commercial formulation Flavamed® tablet (FT), which contains AMB as an active compound, was performed systematically using thermal and spectroscopic methods, along with a sophisticated and practical statistical approach. AMB proved to be a heat-stable and humidity-sensitive drug. For its successful formulation, special attention should be addressed to excipients since it was found that polyvinyl pyrrolidone and Mg stearate affect the thermal stability of AMB. At the same time, lactose monohydrate contributes to faster degradation of AMB and change in decomposition mechanism. It was found that the n-th order kinetic model mechanistically best describes the decomposition process of pure AMB and in Flavamed® tablets

High pressure densities of ethylene glycol and caffeine mixtures

Ethylene glycol is a well-known fluid that is recognized for its application in heat transfer processes [1]. In order to improve its characteristics and performances, adding other particles in the mixture of ethylene glycol and water, such as nanoparticles has been investigated [2]. A substance widespread available, easily distributed and cost effective is caffeine. Caffeine can be recycled from coffee or tea waste, which makes it profitable and sustainable. Literature data state that caffeine addition to ethylene glycol improves its properties as a heat transfer fluid, primarily due to higher heat capacities, higher system fluidity and lower viscosity [3]. This work investigates different thermodynamic properties of caffeine + ethylene glycol mixtures. Densities have been measured at high pressures from (0,1 – 60) MP and at the temperature range (20 - 140) ºC. All measurements were performed using an Anton Paar DMA 5000 HP density meter with a vibrating tube [4]. The obtained results were fitted by the modified Tammann-Tait equation and parameters were used to determine the isothermal compressibility coefficient, the coefficient of isobaric expansion, the internal pressure and the difference of specific heat capacity at constant pressure and constant volume. Experimental values and calculated thermodynamic parameters reported in this work will help in concluding whether the caffeine + ethylene glycol mixtures are good candidates as heat transfer fluids

Ionic liquid-derived carbon-supported metal electrocatalysts as anodes in direct borohydride-peroxide fuel cells

Three different carbon-supported metal (gold, platinum, nickel) nanoparticle (M/c-IL) electrocatalysts are prepared by template-free carbonization of the corresponding ionic liquids, namely [Hmim][AuCl4 ], [Hmim]2 [PtCl4 ], and [C16mim]2 [NiCl4 ], as confirmed by X-ray diffraction analysis, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and Raman spectroscopy. The electrochemical investigation of borohydride oxidation reaction (BOR) at the three electrocatalysts by cyclic voltammetry reveals different behavior for each material. BOR is found to be a first-order reaction at the three electrocatalysts, with an apparent activation energy of 10.6 and 13.8 kJ mol−1 for Pt/c-IL and Au/c-IL electrocatalysts, respectively. A number of exchanged electrons of 5.0, 2.4, and 2.0 is obtained for BOR at Pt/c-IL, Au/c-IL, and Ni/c-IL electrodes, respectively. Direct borohydride-peroxide fuel cell (DBPFC) tests done at temperatures in the 25–65◦C range show ca. four times higher power density when using a Pt/c-IL anode than with an Au/c-IL anode. Peak power densities of 40.6 and 120.5 mW cm−2 are achieved at 25 and 65◦C, respectively, for DBPFC with a Pt/c-IL anode electrocatalyst. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/)