The analysis of simultaneous clove/oregano and clove/thyme supercritical extraction

The goal of present work was to investigate and explain kinetics and mass transfer phenomena occurring during the SFE from the mixture of two plants with different initial composition. The extractions from pure clove, oregano and thyme as well as from clove/oregano (C/O) and clove/thyme (C/T) mixtures with various initial compositions of plant material were carried out using supercritical CO₂ at 10 MPa and 40 °C. The results indicated that presence of light compounds in supercritical CO₂ originated from the oregano leaves or thyme at the beginning of extraction process increases the extraction rate of compounds from clove bud. Only small added amounts of oregano or thyme to clove bud (C/O - 90:10%, w/w; or C/T - 84:16%, w/w) in the starting plant mixture had the same effect resulted in the similar and the highest increase of the extraction rate and had negligible influence on total extraction yield compared to extract isolated from pure clove. Different mathematical models were used for simulation of experimental data which showed that the highest increase of the solubility of extractable compounds in supercritical CO₂ as well as the highest mass transfer rate in the solid phase during extractions existed during extraction from C/O (90:10, w/w) and C/T (84:16, w/w) mixtures. Decrease of SC CO₂ consumption or shorter time of extraction necessary for achieving desired extract yield in the case of SFE of the clove buds could be important for industrial-scale application.     

The influence of the preparation conditions and filler content on thermal properties of poly‐l‐lactide and hydroxyapatite/poly‐l‐lactide nanocomposite

Poly‐l ‐lactide (PLLA) and hydroxyapatite/poly‐l ‐lactide (HAp/PLLA) are two widely used biomaterials for three‐dimensional scaffolds, drug release matrices and implantable medical devices for reparation of bone tissue; diversity in the initial preparation and filler content has a significant influence on different properties such as morphology and crystallinity, thus playing a considerable role in most of these applications. For this reason, PLLA and HAp/PLLA samples with a large difference in crystallinity (from below 20% to over 70%) and filler content (up to 86 wt% of HAp nanoparticles with an average diameter of 80 nm) were prepared and consequent dissimilarities in morphology, crystallinity and thermal properties were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXD) measurements and Fourier transform infrared (FTIR) spectroscopy. Special attention was devoted to analyzing data obtained from thermal measurements. A three‐phase model was employed in order to describe the heat capacity step decline in the nanocomposite; the evolution in different polymer fractions, the crystalline fraction and the mobile and rigid amorphous fractions, with filler content was determined. © 2017 Society of Chemical Industry     

A study of the structural and morphological properties of Ni–ferrite,Zn–ferrite and Ni–Zn–ferrites functionalized with starch

Zinc–ferrite, nickel–ferrite and mixed nickel–zinc ferrites were successfully synthesized via the thermal decomposition method from acetylacetonate complexes. To control the particle size and enhance dispersibility in an aqueous medium, starch, a natural and biocompatible compound, was used for the first time for coating such magnetic powders. X-ray powder diffraction (XRPD) was performed to study the structural properties of all samples. The presence of a single-phase spinel structure as well as the cation distribution in both sites of all investigated magnetic powders was confirmed. The values of unit cell parameters obtained from the results of the Rietveld analysis decreased, while the average crystallite size increased with increasing Ni²⁺ content. The average microstrain parameters unambiguously showed a change in the spinel structure with cation distribution. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) analyses were also utilized to characterize the synthesized materials, corroborating the XRPD data. The obtained results indicated that functionalization by starch was successfully achieved.     

Synthesis and Properties of a New Dental Material Based on Nano‐Structured Highly Active Calcium Silicates and Calcium Carbonates

A synthesis of a new dental material, based on nano‐structured highly active calcium silicates and calcium carbonates, is described in this paper. Phase analysis of this material, before and after hydration, was performed by X‐ray diffraction and showed that active silicate phases were transformed into tobermorite phase, while carbonates remained unchanged. The mechanism of hydration was fully described. The morphology of the sample was studied by SEM, and typical appearance of the present phases was particularly discussed. The mechanical properties and setting time of this material make it very promising for potential application in dental practice.     

Plant protection product residues in white grapes and wines of “Malvasia Istriana” produced in Istria

Monitorting of plant protection product residues was performed in 12 grape and 66 wine samples of “Malvasia Istriana” variety, produced in Istria winegrowing region of Croatia and Slovenia. The samples were analysed for the presence of 169 different active compounds using two multiresidual analytical methods: gas chromatography coupled with mass spectrometry and liquid chromatography coupled with tandem mass spectrometry. Residues were found in 58.3% of all the inspected grape samples and in 28.8% of all the inspected wine samples. Beside that contents of residues in grapes were below 10% of maximum residue level values and they should not represent any risk for “Malvasia Istriana” grape or wine consumers.     

Camphor and Eucalyptol—Anticandidal Spectrum,Antivirulence Effect,Efflux Pumps Interference and Cytotoxicity

Candidaalbicans represents one of the most common fungal pathogens. Due to its increasing incidence and the poor efficacy of available antifungals, finding novel antifungal molecules is of great importance. Camphor and eucalyptol are bioactive terpenoid plant constituents and their antifungal properties have been explored previously. In this study, we examined their ability to inhibit the growth of different Candida species in suspension and biofilm, to block hyphal transition along with their impact on genes encoding for efflux pumps (CDR1 and CDR2), ergosterol biosynthesis (ERG11), and cytotoxicity to primary liver cells. Camphor showed excellent antifungal activity with a minimal inhibitory concentration of 0.125–0.35 mg/mL while eucalyptol was active in the range of 2–23 mg/mL. The results showed camphor’s potential to reduce fungal virulence traits, that is, biofilm establishment and hyphae formation. On the other hand, camphor and eucalyptol treatments upregulated CDR1; CDR2 was positively regulated after eucalyptol application while camphor downregulated it. Neither had an impact on ERG11 expression. The beneficial antifungal activities of camphor were achieved with an amount that was non-toxic to porcine liver cells, making it a promising antifungal compound for future development. The antifungal concentration of eucalyptol caused cytotoxic effects and increased expression of efflux pump genes, which suggests that it is an unsuitable antifungal candidate.     

Cerebral Expression of Metabotropic Glutamate Receptor Subtype 5 in Idiopathic Autism Spectrum Disorder and Fragile X Syndrome: A Pilot Study

Multiple lines of evidence suggest that dysfunction of the metabotropic glutamate receptor subtype 5 (mGluR₅) plays a role in the pathogenesis of autism spectrum disorder (ASD). Yet animal and human investigations of mGluR₅ expression provide conflicting findings about the nature of dysregulation of cerebral mGluR₅ pathways in subtypes of ASD. The demonstration of reduced mGluR₅ expression throughout the living brains of men with fragile X syndrome (FXS), the most common known single-gene cause of ASD, provides a clue to examine mGluR₅ expression in ASD. We aimed to (A) compare and contrast mGluR₅ expression in idiopathic autism spectrum disorder (IASD), FXS, and typical development (TD) and (B) show the value of positron emission tomography (PET) for the application of precision medicine for the diagnosis and treatment of individuals with IASD, FXS, and related conditions. Two teams of investigators independently administered 3-[¹⁸F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([¹⁸F]FPEB), a novel, specific mGluR₅ PET ligand to quantitatively measure the density and the distribution of mGluR₅s in the brain regions, to participants of both sexes with IASD and TD and men with FXS. In contrast to participants with TD, mGluR₅ expression was significantly increased in the cortical regions of participants with IASD and significantly reduced in all regions of men with FXS. These results suggest the feasibility of this protocol as a valuable tool to measure mGluR₅ expression in clinical trials of individuals with IASD and FXS and related conditions.     

A model of digital identity for better information security in e-learning systems

The Journal of Supercomputing - The trend of rapid development of information technologies is creating new challenges in information security such as security management of identities in e-learning...     

Migration of bisphenol a into food simulants and meat rations during initial time of storage

The aim of this work was to assume the amount of BPA that can migrate to food packed into the cans coated by epoxy-phenolic lacquer. The assumption was made by determining the amount of BPA which migrates from the inner can coating to different food simulants: 3% acetic acid, 10% ethanol, their mixture (3% acetic acid +10% ethanol), and 50% ethanol. The examined tinplate cans were made by the special requirements of the Serbian Armed Forces. Further, the effect of the sterilization process and the very initial time of storage (15–105 days), on the level of BPA in the canned meatballs in tomato sauce, which are in the regular use of the Serbian Armed Forces, was examined. The BPA content was determined by the high performance liquid chromatography-mass spectrometry (HPLC–MS), and compared with BPA content found in the food simulants.