Determination of environmental persistence and thermogravimetric analysis of paper artificially aged by photoirradiation

Fabriano paper was aged by irradiation with ultraviolet light (k=310) in a veterometer for 300 hours. At fixed time intervals, samples of the paper under test were analysed by titanium dioxide photosensor to determine electrochemically the "environmental persistence" index, by a suitable conductimeter method, to determine the specific conductivity variation and by thermogravimetry to determine the moisture content, the onset temperature of the cellulose degradation process and the value of the activation energy of the same process. The behaviour of these different types of indicators displayed approximately monotonous trends as a function of time.     

Magnetic–Fluorescent Colloidal Nanobeads: Preparation and Exploitation in Cell Separation Experiments

Nanostructures displaying fluorescence and magnetic properties at the same time are potentially useful for achieving simultaneous bio‐separation and bio‐sensing (e.g., magnetic separation coupled with multiplexing optical detection of different tumour cell populations). Spherical nanobeads that display both fluorescent and magnetic features are reported; they are fabricated by grafting fluorescent oligothiophene molecules to an amphiphilic polymer that is then used to enwrap iron oxide nanoparticles, which acts as the magnetic domain. By tuning experimental conditions, control over the number of magnetic nanoparticles per bead and over the bead diameter (30–400 nm) was achieved. A cell separation efficiency of the level required for cell sorting applications is also reported.

     

Synthesis and characterization of light emitting Eu2O3 films on Si substrates

We have studied the optical and structural properties of Eu₂O₃ thin films grown by RF magnetron sputtering on Si substrates. The films have been annealed in O₂ ambient to improve their properties. The intensity of the photoluminescence (PL) signal detected at room temperature from the films depends on the temperature of the thermal process. The structural characterization of the films, performed by transmission electron microscopy, energy filtered transmission electron microscopy and x-ray diffraction, reveals that annealing processes performed at temperatures higher than 900 °C induce a mixing at the Eu₂O₃–Si interface, leading to the formation of a silicate-like layer, which is responsible for the observed decrease of the PL intensity.     

Spatial periodic forcing can displace patterns it is intended to control

Spatial periodic forcing of pattern-forming systems is an important, but lightly studied, method of controlling patterns. It can be used to control the amplitude and wave number of one-dimensional periodic patterns, to stabilize unstable patterns, and to induce them below instability onset. We show that, although in one spatial dimension the forcing acts to reinforce the patterns, in two dimensions it acts to destabilize or displace them by inducing two-dimensional rectangular and oblique patterns.     

Targeted Drug Delivery Systems for Eliminating Intracellular Bacteria

The intracellular survival of pathogenic bacteria requires a range of survival strategies and virulence factors. These infections are a significant clinical challenge, wherein treatment frequently fails because of poor antibiotic penetration, stability, and retention in host cells. Drug delivery systems (DDSs) are promising tools to overcome these shortcomings and enhance the efficacy of antibiotic therapy. In this review, the classification and the mechanisms of intracellular bacterial persistence are elaborated. Furthermore, the systematic design strategies applied to DDSs to eliminate intracellular bacteria are also described, and the strategies used for internalization, intracellular activation, bacterial targeting, and immune enhancement are highlighted. Finally, this overview provides guidance for constructing functionalized DDSs to effectively eliminate intracellular bacteria.     

Visible-Light Promoted Intramolecular para-Cycloadditions on Simple Aromatics

Dearomative cycloadditions are a powerful tool to access a large chemical space exploiting simple and ubiquitous building blocks. The energetic burden due to the loss of aromaticity has however greatly limited their synthetic potential. We devised a general intramolecular method that overcomes these limitations thanks to the photosensitization of allenamides. The visible-light-promoted process gives complex [2.2.2]-(hetero)-bicyclooctadienes at room temperature, likely through the stabilization of transient (bi)radicals by naphthalene. The reaction tolerates several valuable functionalities, offering a convenient handle for a myriad of applications, including original isoindoles and metal complexes.     

Evaluation of the Stereochemical Lability of Benzo-Cycloheptene-Based Drugs Endowed with Potentially Modulable Planar Chirality

An experimental and theoretical study was carried out to analyze the configurational lability possessed by some of the most common drugs endowed with a central non-planar seven-membered cycloheptadiene ring, which confers chirality to these compounds. In fact, the absence of planarity allows the existence of two enantiomeric species that can interconvert thanks to a ring overturning mechanism. The energy barrier that opposes the inversion of the chiral tricyclic scaffold characterizing such species, which is strongly dependent on the presence of appropriate substituents on the two external cycles, has been investigated through Dynamic-HPLC and off-column racemization techniques, as well as through assessments based on molecular modelling approaches. Interesting indications were obtained by making targeted structural changes to allow accurate control of the stereolability characterizing the tricyclic framework.     

Amphiphilic Iminosugar Pharmacological Chaperones towards β-Glucocerebrosidase: Self-Assembly and Biological Activity

Pharmacological chaperones (PCs) can restore correct enzymatic activity at sub-inhibitory concentrations and are considered an emerging therapy for Gaucher Disease (GD). Amphiphilic PCs show more favourable cross-membrane properties and have a higher activity on cells than hydrophilic PCs. To investigate whether the biological activity of amphiphilic iminosugars is related to their state as monomers or as micellar aggregates, we synthesized some novel N-alkylated iminosugars and performed physico-chemical characterizations in the solid state and in aqueous dispersion of the best compound in terms of biological activity. The results suggest that the C12 N-alkylated iminosugar 10 exerts its biological activity in the monomeric state, and that the low cell viability observed in the presence of a 50 μM concentration of compound 10 is not related to the formation of micellar aggregates in solution.