Utilization of low-cost sorbent for removal and separation of 134Cs, 60Co and 152+154Eu radionuclides from aqueous solution

Eggshell material was used as low-cost and eco-friendly biosorbent for removal of ¹³⁴Cs, ⁶⁰Co and ^152+154Eu radionuclides from aqueous solution. The eggshell material was calcined at 500 and 800 °C, and then characterized. Comparative studies on the natural and calcined eggshell for sorption of the three radionuclides were carried out. It was found that, the uptake is in the order: Eu(III) > Co(II) > Cs(I). Further, column chromatography was used in separation of ¹³⁴Cs, ⁶⁰Co and ^152+154Eu using 0.15, 0.2 and 0.5 mol/l nitric acid, respectively. Eggshell material can be considered as a promising material for separation of radionuclides from radioactive waste solution.     

Aliphatic Amine Discrimination by Pentafluorophenyl Dibromo BODIPY

Two new fluorescent BODIPY dyes have been designed and synthesized. They dyes differ in their meso substituents, which have different electronic properties. Their selective reactivity towards an Ar‐S_N2 reaction has been explored as a potential basis for colorimetric and fluorescent discrimination of primary, secondary and tertiary aliphatic amines. This dual‐mode, instantaneous recognition event is unprecedented.     

Repurposing of Omarigliptin as a Neuroprotective Agent Based on Docking with A2A Adenosine and AChE Receptors,Brain GLP-1 Response and Its Brain/Plasma Concentration Ratio after 28 Days Multiple Doses in Rats Using LC-MS/MS

The authors in the current work suggested the potential repurposing of omarigliptin (OMR) for neurodegenerative diseases based on three new findings that support the preliminary finding of crossing BBB after a single dose study in the literature. The first finding is the positive results of the docking study with the crystal structures of A_2A adenosine (A2AAR) and acetylcholine esterase (AChE) receptors. A2AAR is a member of non-dopaminergic GPCR superfamily receptor proteins and has essential role in regulation of glutamate and dopamine release in Parkinson’s disease while AChE plays a major role in Alzheimer’s disease as the primary enzyme responsible for the hydrolytic metabolism of the neurotransmitter acetylcholine into choline and acetate. Docking showed that OMR perfectly fits into A2AAR binding pocket forming a distinctive hydrogen bond with Threonine 256. Besides other non-polar interactions inside the pocket suggesting the future of the marketed anti-diabetic drug (that cross BBB) as a potential antiparkinsonian agent while OMR showed perfect fit inside AChE receptor binding site smoothly because of its optimum length and the two fluorine atoms that enables quite lean fitting. Moreover, a computational comparative study of OMR docking, other 12 DPP-4 inhibitors and 11 SGLT-2 inhibitors was carried out. Secondly, glucagon-like peptide-1 (GLP-1) concentration in rats’ brain tissue was determined by the authors using sandwich GLP-1 ELISA kit bio-analysis to ensure the effect of OMR after the multiple doses’ study. Brain GLP-1 concentration was elevated by 1.9-fold following oral multiple doses of OMR (5 mg/kg/day, p.o. for 28 days) as compared to the control group. The third finding is the enhanced BBB crossing of OMR after 28 days of multiple doses that had been studied using LC-MS/MS method with enhanced liquid–liquid extraction. A modified LC-MS/MS method was established for bioassay of OMR in rats’ plasma (10–3100 ng/mL) and rats’ brain tissue (15–2900 ng/mL) using liquid–liquid extraction. Alogliptin (ALP) was chosen as an internal standard (IS) due to its LogP value of 1.1, which is very close to the LogP of OMR. Extraction of OMR from samples of both rats’ plasma and rats’ brain tissue was effectively achieved with ethyl acetate as the extracting solvent after adding 1N sodium carbonate to enhance the drug migration, while choosing acetonitrile to be the diluent solvent for the IS to effectively decrease any emulsion between the layers in the stated method of extraction. Validation results were all pleasing including good stability studies with bias of value below 20%. Concentration of OMR in rats’ plasma were determined after 2 h of the latest dose from 28 days multiple doses, p.o, 5 mg/kg/day. It was found to be 1295.66 ± 684.63 ng/mL estimated from the bio-analysis regression equation. OMR passed through the BBB following oral administration and exhibited concentration of 543.56 ± 344.15 ng/g in brain tissue, taking in consideration the dilution factor of 10. The brain/plasma concentration ratio of 0.42 (543.56/1295.66) was used to illustrate the penetration power through the BBB after the multiple doses for 28 days. Results showed that OMR passed through the BBB more effectively in the multiple dose study as compared to the previously published single dose study by the authors. Thus, the present study suggests potential repositioning of OMR as antiparkinsonian agent that will be of interest for researchers interested in neurodegenerative diseases.     

Study of the usability of sinusoidal function heat flux based on enthalpy-porosity technique for PCM-related applications

Journal of Thermal Analysis and Calorimetry - The present study summarizes a two-dimensional (2D) numerical simulation of a phase change material (PCM) melting/solidification processes in a square...     

Characterization of Phenolic Compounds,Vitamin E and Fatty Acids from Monovarietal Virgin Olive Oils of “Picholine marocaine” Cultivar

Olive oil is an important product in the Mediterranean diet, due to its health benefits and sensorial characteristics. Picholine marocaine is the most cultivated variety in Morocco. The present research aims to evaluate the phenolic compounds, vitamin E and fatty acids of commercial Picholine marocaine virgin olive oils (VOOs) from five different North Moroccan provinces (Chefchaouen, Taounate, Errachidia, Beni Mellal and Taza), using HPLC-photodiode array (PDA)/electrospray ionization (ESI)-MS, normal phase (NP)-HPLC/ fluorescence detector (FLD) and GC-flame ionization detector (FID)/MS, respectively. The obtained results showed an average content of 130.0 mg kg⁻¹ of secoiridoids (oleuropein aglycone, 10-hydroxy-oleuropein aglycone and ligstroside aglycone, oleocanthal and oleacein), 108.1 mg kg⁻¹ of phenolic alcohols (tyrosol and hydroxytyrosol), 34.7 mg kg⁻¹ of phenolic acids (caffeic acid, ferulic acid and elenolic acid), and 8.24 mg kg⁻¹ of flavonoids (luteolin, luteolin glucoside, apigenin). With regard to vitamin E, α-tocopherol was the most abundant vitamin E (57.9 mg kg⁻¹), followed by α-tocotrienol (2.5 mg kg⁻¹), γ-tocopherol (4.5 mg kg⁻¹) and β-tocopherol (1.9 mg kg⁻¹), while δ-tocopherol was not detected. Moreover, 14 fatty acids were found and, among them, oleic acid (76.1%), linoleic acid (8.1%) palmitic acid (8.7%) and stearic acid (2.5%) were the major fatty acids detected. Finally, heat map and principal component analysis allowed us to classify the studied provinces in terms of VOO chemical composition: Chefchaouen (tyrosol and hydroxytyrosol), Taounate (oleuropein aglycone), Errachidia (ferulic acid, w-3 and w-6), Beni Mellal (oleocanthal) and Taza (luteolin and oleic acid).     

Finite-dimensional left ideals in some algebras associated with a locally compact group

Let be a locally compact group, let be its group algebra, let be its usual measure algebra, let be the second dual of with an Arens product, and let be the conjugate of the space of bounded, left uniformly continuous, complex-valued functions on with an Arens-type product. We find all the finite-dimensional left ideals of these algebras. We deduce that such ideals exist in and if and only if is compact, and in (except those generated by right annihilators of ) and if and only if is amenable.

     

Angular Dependence of Lateral and Levitation Forces in Asymmetric Small Magnet/Superconducting Systems

The dipole-dipole interaction model is used to calculate the angular dependence of lateral and levitation forces on a small permanent magnet and a cylindrical superconductor in the Meissner state lying laterally off the symmetric axis of the cylinder. Under the assumption that the lateral displacement of the magnet is small compared with the physical dimensions of the system, we obtain analytical expressions for the lateral and levitation forces as functions of geometrical parameters of the superconductor as well as the height, the lateral displacement and the orientation of magnetic moment of the magnet. The effect of thickness and radius of the superconductor on the levitation force is similar to that for a symmetric magnet/superconducting cylinder system, but within the range of lateral displacement. The splitting in the levitation force increases with the increasing angle of orientation of the magnetic moment of the magnet. For a given lateral displacement of the magnet, the lateral force vanishes when the magnetic moment is perpendicular to the surface of the superconductor and has a maximum value when the moment is parallel to the surface. For a given orientation of the magnetic moment, the lateral force has a linear relationship with the lateral displacement. The stability of the magnet above the superconducting cylinder is discussed in detail.     

Preparation of PtSnSb/C by an alcohol reduction process for direct ethanol fuel cell (DEFC)

PtSn/C and PtSnSb/C electrocatalysts (20 wt.% metal loading) were prepared by an alcohol reduction process using H₂PtCl₆.6H₂O, SnCl₂.2H₂O, and Sb(OOCCH3) as metal sources, ethylene glycol as solvent and reducing agent, and Vulcan XC72 as carbon support. The electrocatalysts were characterized by energy dispersive X-ray analysis, X-ray diffraction, and transmission electron microscopy, while that the performance for ethanol oxidation was investigated by cyclic voltammetry and chronoamperommetry (chrono) at room temperature. The diffractograms of the PtSn/C and PtSnSb/C electrocatalysts showed four peaks associated to Pt face-centered cubic structure and two peaks that were related to a SnO₂ phase. For PtSb/C and PtSnSb/C electrocatalysts, no Sb (antimony) peaks corresponding to a metallic antimony or antimony oxide phases were observed. Transmission electron microscopy images showed that the metal particles were homogeneously distributed over the support. The PtSnSb/C (50:45:05) electrocatalyst showed an increase of performance for ethanol oxidation in relation to PtSn/C electrocatalyst at room temperature. In the tests at 100 °C on a single cell of a direct ethanol fuel cell, the maximum power density of PtSnSb/C (50:45:05) electrocatalyst was slightly higher than that of PtSn/C electrocatalyst.     

Domain-shape-based modulation of Čerenkov second-harmonic generation in multidomain strontium barium niobate

We study experimentally and numerically the second-harmonic ?erenkov emission with two different characteristic azimuthal intensity distributions in strontium barium niobate with a random structure of χ2 nonlinearity. We monitor in situ the ?erenkov emission during domain switching and show that a change of domain size and shape results in a fourfold azimuthal modulation of the ?erenkov cone.     

A continuum damage model for the high-cycle fatigue life prediction of styrene-butadiene rubber under multiaxial loading

In the present contribution, the relationship between the fatigue life of styrene-butadiene rubber (SBR) and the stretch amplitude was established. Focusing on the multiaxial loading effect on the life duration of SBR, experimental tests were conducted using cylindrical specimens subjected to tension and torsion loadings under constant and variable amplitudes. Based upon the continuum damage mechanics approach, a three-dimensional model was derived and coupled with the cracking energy density criterion to predict the fatigue life of SBR. The capabilities of the model, which requires only three damage parameters to be identified, were analysed and a good agreement between predicted values and experimental data were clearly highlighted for tension and torsion loadings both in constant and variable amplitudes.