Visible light mediated azomethine ylide formation-photoredox catalyzed [3+2] cycloadditions

The synthesis of highly functionalised N-heterocycles has been achieved by the visible light mediated photoredox conversion of tertiary amines to azomethine ylides and their further reaction with maleimide derivatives as dipolarophiles.     

DMA analysis to predict the performance of waterborne coatings

In previous studies some waterborne coatings, specifically formulated for the scope of the research, were studied during an artificial weathering process by means of dynamic mechanical analysis (DMA) technique. In those studies the chemical and physical parameters which mainly affect the performance of coatings and their evolution during weathering were measured. The aim was to predict the performance of coatings for exterior wood during their service life by means of accelerated artificial tests and instrumental measures. In this study four commercial products were artificially weathered following the European standard EN 927-6. The changes in the mechanical properties were measured by means of the DMA as reported in the previous studies. With this research the authors have verified the capability of this method to predict the performance in use of coatings.     

Surface Modification with Control over Ligand Density for the Study of Multivalent Biological Systems

In the study of multivalent interactions at interfaces, as occur for example at cell membranes, the density of the ligands or receptors displayed at the interface plays a pivotal role, affecting both the overall binding affinities and the valencies involved in the interactions. In order to control the ligand density at the interface, several approaches have been developed, and they concern the functionalization of a wide range of materials. Here, different methods employed in the modification of surfaces with controlled densities of ligands are being reviewed. Examples of such methods encompass the formation of self-assembled monolayers (SAMs), supported lipid bilayers (SLBs) and polymeric layers on surfaces. Particular emphasis is given to the methods employed in the study of different types of multivalent biological interactions occurring at the functionalized surfaces and their working principles.     

The Structure of Sub‐nm Platinum Clusters at Elevated Temperatures

Little is known about metallic clusters consisting merely of a dozen of atoms or even less, despite of their importance in catalysis and crystal nucleation. Scanning transmission electron microscopy (STEM) provides direct atomic structure information but has inherently suffered from limited time resolution. We employ fast dynamic STEM combined with a spatio‐temporal image denoising algorithm to explore the structure and stability of Pt clusters on carbon, which represents a highly relevant catalysis system. At room temperature, dynamic amorphous 2D structures are found, while above ≈300 °C, the clusters transform into a crystalline state. Our experimental and theoretical data reveal an unexpected strong trend of the crystalline clusters to exhibit the face‐centered cubic, bulk structure of Pt with cuboidal geometries being most prominent.     

A Detailed Study of the (Electro)chemical Behavior of Bis(trifluoromethanesulfonyl)imide Based Ionic Liquids at Different Purification Steps

A systematic investigation of the major impurities content as well as of their effect on the electrochemical behavior of synthesized N‐butyl‐N‐methylpyrrolidinium (Py_1.4), N‐(2‐methoxyethyl)‐N‐methylpyrrolidinium (Py_1.102) and 1‐butyl‐3‐methylimidazolium (bmim) bis(trifluoromethanesulfonyl)imide has been carried out and the efficacy of an optimized multistep purification protocol for obtaining ILs suitable for electrochemical applications has been verified.     

Synthesis and Characterization of an Unusual 68-Electrons Os4Se3 Carbonyl Phosphane Cluster

The 68-electrons, phosphane-substituted, osmium selenido-carbonyl cluster [Os₄Se₃(CO)₁₀(dppm)] (cluster 3; dppm = bis(diphenylphosphino)methane) has been obtained by reaction under mild experimental conditions between [Os₃(CO)₁₂] and the diphosphane diselenide dppmSe₂. Its crystal and molecular structure has been elucidated by X-ray diffraction methods. Cluster 3 contains only two Os–Os bonds as suggested by its electron count. It can be described as derived from the open-triangular nido cluster [Os₃(μ₃-Se)₂(CO)₉] through substitution of one CO ligand by the four-electrons donor osmiaselone fragment [CH₂(Ph₂P)₂](CO)₂Os=Se. The replacement of a two-electrons donor carbonyl with a four-electron donor fragment produces the cleavage of one Os–Os bond in the nido cluster. Under the adopted experimental conditions, other products of the reaction between [Os₃(CO)₁₂] and dppmSe₂ are the clusters [Os₃(μ₃-Se)₂(CO)₉] (1), [Os₃(μ₃-Se)₂(CO)₇(μ-dppm)] (2), and [Os₃(μ₃-Se)(CO)₈(μ-dppm)] (4), already described in the literature.     

Isolation of mineralizing Nestin+ Nkx6.1+ vascular muscular cells from the adult human spinal cord

Background

Evidence suggests that rheumatoid arthritis (RA) may enhance or reduce the progression of Alzheimer's disease (AD). The present study was performed to directly explore the effects of collagen-induced rheumatoid arthritis (CIA) on amyloid plaque formation, microglial activation, and microvascular pathology in the cortex and hippocampus of the double transgenic APP/PS1 mouse model for AD. Wild-type or APP/PS1 mice that received type II collagen (CII) in complete Freund's adjuvant (CFA) at 2 months of age revealed characteristics of RA, such as joint swelling, synovitis, and cartilage and bone degradation 4 months later. Joint pathology was accompanied by sustained induction of IL-1β and TNF-α in plasma over 4 weeks after administration of CII in CFA.

Results

CIA reduced levels of soluble and insoluble amyloid beta (Aβ) peptides and amyloid plaque formation in the cortex and hippocampus of APP/PS1 mice, which correlated with increased blood brain barrier disruption, Iba-1-positive microglia, and CD45-positive microglia/macrophages. In contrast, CIA reduced vessel density and length with features of microvascular pathology, including vascular segments, thinner vessels, and atrophic string vessels.

Conclusions

The present findings suggest that RA may exert beneficial effects against Aβ burden and harmful effects on microvascular pathology in AD.     

Status of PRESS-MAG-O: The experimental apparatus to probe materials and phenomena under extreme conditions at Frascati

In this contribution we up-to-date the status of the PRESS-MAG-O device, a new instrument under commissioning at the INFN designed to perform magnetic and spectroscopic experiments on samples under extreme conditions. The system has been designed to work at SINBAD, the IR synchrotron radiation beamline operational at DAΦNE. The instrument, that is the result of a significant R&D, will allow performing concurrent high harmonic ac magnetic susceptibility measurements and magneto-optic experiments on a sample under high pressure, with a variable DC magnetic field in a wide temperature range. The vacuum vessel has been designed with four crossing windows to allow optical measurements in the transmission geometry on the sample loaded inside a Diamond Anvil Cell. A new superconducting miniaturized micro-SQUID gradiometer has been also developed to detect the low magnetic signal of the sample and a customized optical system has also been designed to perform IR synchrotron radiation experiments.