Large Interactive Touchscreens as an Opportunity for Synchronous Hybrid Teaching during the COVID-19 Pandemic and Beyond.

The year 2020 will be remembered as the year of COVID-19 and its subsequent lockdowns. The time to return to face-to-face teaching has arrived, but the shadow of the disease still hangs over teachers, students, and society. Disruption in teaching can still occur for students, or even teachers, if they are either diagnosed as COVID-19 positive or as a contact case and forced to self-isolate.

Application of Doehlert experimental design for the removal of radium from aqueous solution by cross-linked phenoxycalix[4]pyrrole-polymer using Ba(II) as a model.

Ra-226 is a naturally occurring radionuclide that is derived from uranium-238 series, and it is present at low concentrations in rocks, soil, and groundwater. Many efforts have been exerted for the decontamination of radium from aqueous media in order to meet the increasing water demand of the population. To this aim, a new polymer based on cross-linked phenoxycalix[4]pyrrole was designed and employed in solid/liquid extractions in order to remove radium from aqueous solutions.

Solid-liquid extraction of iodide and bromide from aqueous media by a new water-insoluble phenoxycalix[4]pyrrole-epichlorohydrin polymer.

The present study describes the synthesis of the first phenoxycalix[4]pyrrole-epichlorohydrin based polymer. The advantage of the latter resides in its fast-single step synthesis protocol, low cost, water insolubility and its unexpected anion extraction capacity. The study of this polymer by various solid/liquid extractions with halides in aqueous solutions and quantitative ion chromatography analysis showed that unlike other calix[4]pyrrole-based entities, this polymer extracts iodide rather than bromide and fluoride owing to the presence of large extraction pockets.

A click mediated route to a novel fluorescent pyridino-extended calix[4]pyrrole sensor: synthesis and binding studies.

A novel fluorescent aryl-extended phenoxycalix[4]pyrrole ditopic sensor with enhanced cation recognition properties was efficiently synthesized via click chemistry and characterized through both molecular fluorescence and nuclear magnetic resonance spectroscopy. Results demonstrate the selectivity of this fluorescent sensor for fluoride when taking into account its interaction with anions, while its cation binding properties showed selectivity for iron, and its sensing properties for several cations in dimethylsulfoxide. This work introduces a new ditopic receptor able to complex major environmentally relevant species and depicts the importance of click chemistry in the introduction of new tetra-chromophoric calix[4]pyrrole binding platforms with specific photophysical properties.

Ultrasound-Assisted Heterogeneous Synthesis of Bio-Based Oligo-Isosorbide Glycidyl Ethers: Towards Greener Epoxy Precursors.

The substitution of toxic precursors such as bisphenol A by renewable and safer molecules has become a major challenge. To overcome this challenge, the 12 principles of green chemistry should be taken into account in the development of future sustainable chemicals and processes. In this context, this paper reports the highly efficient synthesis of oligo-isosorbide glycidyl ethers from bio-based starting materials by a rapid one-pot heterogeneous ultrasound-assisted synthesis.

Efficient synthesis of 4-substituted--phthalaldehyde analogues: toward the emergence of new building blocks.

4-Methoxy--phthalaldehyde and 4-hydroxy--phthalaldehyde are potentially useful molecules for fluorimetric analysis of a variety of amines and for the elaboration of complex molecular architectures. Nevertheless, literature generally describes their synthesis in very low yield (below 5%), mainly due to the inefficiency of the last oxidation step. In this paper, we report a reliable synthesis of 4-substituted--phthalaldehyde analogues in 51% overall yield owing to the addition of a protecting step of the unstable key intermediate 4,5-dihydroisobenzofuran-5-ol.

First evaluation of drug-in-cyclodextrin-in-liposomes as an encapsulating system for nerolidol.

Nerolidol, a naturally occurring sesquiterpene with antimicrobial activities, is a promising candidate as a natural alternative for synthetic preservatives in food. However, its application is limited by low aqueous solubility and stability. In this study, conventional liposomes and drug-in-cyclodextrin-in-liposomes (DCLs) were evaluated for the first time as encapsulating materials for nerolidol.

The effect of cyclodextrin complexation on the solubility and photostability of nerolidol as pure compound and as main constituent of cabreuva essential oil.

Nerolidol (Ner), a major component of many plant essential oils, is known for its various biological properties. However, the low solubility of Ner in water and its susceptibility to degradation limit its application. The aim of our study was to improve the solubility and photostability of Ner through its encapsulation in different cyclodextrins (CDs).

Synthesis of modified potato starches for aqueous solubilization of benzo[a]pyrene.

For soil rehabilitation, the surfactant-enhanced remediation has emerged as a promising technology. For this purpose, starch derivatives were difunctionalized by 1,4-butane sultone (BS) and 2-octen-1-ylsuccinic anhydride (OSA). Eight distinct products were obtained under different synthesis conditions.

Recognition of iron ions by carbazole-desferrioxamine fluorescent sensor and its application in total iron detection in airbone particulate matter.

This work reports on an efficient microwave irradiation synthesis of a new fluorescent chemosensor based on desferrioxamine B (DFO-B) and carbazole moiety. Furthermore, this novel chemosensor was employed for a comparative study of real environmental samples of airbone particulate matter collected from Dunkirk (Northern of France). Among selected relevant metal cations present in its airbone particulate matter, such as Na(+), K(+), Mg(2+), Ca(2+), Al(3+), Cr(3+), Mn(2+) and Zn(2+), this molecular device proved to be outstandingly sensitive toward Fe(3+) with a limit of detection of 1.

Supramolecular assistance for the selective demethylation of calixarene-based receptors.

The selective demethylation of methoxy groups of several multifunctionalized 1,3,5-trimethoxycalix[6]arene-based receptors has been achieved. It is shown in this study that the best reagent is trimethylsilyl iodide (TMSI) and that the conformation adopted by the calixarene core is crucial for both the selectivity and the efficiency of the process. A key feature appears to be the "in" or "out" orientation of the methoxy substituents relative to the macrocyclic cavity.

Ultrasound-promoted tosylation of oligo(ethylene glycols).

A series of oligo(ethylene glycols) was efficiently tosylated by ultrasound procedure within dichloromethane in the presence of triethylamine. Results show that sonochemical synthesis of oligo(ethylene glycol) ditosylates has a double advantage since it does not use catalysts and it drastically reduces the reaction time. This straightforward method represents an eco-friendly alternative to the traditional tosylation by pyridine synthesis.