1,720,975 research outputs found
Solid-State Strategy for the S-Conjugation of Peptides Catalyzed by Zeolites and Promoted by Microwave Radiation: A Green Approach
No full textA green synthetic protocol to add a chemical function to a fully deprotected peptide to obtain a bioactive and/or fluorescent-labeled conjugate is reported. A range of S-conjugation reactions promoted by the commercially available LTA zeolite to introduce different substituents on peptide cysteine residues has been shown to take place in the solid state or in the presence of minimal amounts of organic solvent, with yields that are comparable to those of standard solution methods. The additional advantage of the procedure consists of easing the work up, for which green solvents, such as aqueous systems, can be employed. The protocol is implemented with microwave irradiation to shorten the reaction time as dielectric heating increases the diffusion rates of the mechanically milled reactants
Lost in Translation: The determinants and the effect of soft information dispersion in bank lending
No full textTechnologies 4.0: Understanding the evolution of ICT and its role forbusiness development
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Bioactive Glass-Ceramic Scaffolds Coated with Hyaluronic Acid–Fatty Acid Conjugates: A Feasibility Study †
Get PDFPromoting bone healing is a key challenge in our society that can be tackled by developing new implantable biomaterials provided with regenerative properties. In this work, the coating of three-dimensional porous glass-derived scaffolds with hyaluronic acid (HA)-fatty acids was investigated for the first time. The starting scaffolds, based on bioactive silicate glass, were produced by foam replication followed by sintering; then, HA-palmitate and HA-oleate conjugate coatings were deposited on the scaffold struts through a dipping procedure. FT-IR analysis confirmed the successful deposition of the coatings on the surface and struts of the scaffolds, the foam-like architecture of which was maintained as assessed by SEM investigations. The in vitro bioactivity of the HA–fatty-acid-coated scaffolds was studied by immersion tests in simulated body fluid and the subsequent evaluation of hydroxyapatite formation. The deposition of the polymeric coating did not inhibit the apatite-forming ability of scaffolds, as revealed by the formation of nanostructured hydroxyapatite agglomerates 48 h from immersion. These promising results motivate further investigation of these novel bioactive systems, which are expected to combine the bone-bonding properties of the glass with the wound-healing promotion carried out by the polymeric conjugates
ESG performance and the cost of debt. Evidence from the corporate bond market
No full textWe study the impact of ESG performance on the cost of debt in the primary corporate bond market. Using an international sample of 25,234 bonds from 2677 ESG-rated issuers, we analyse yield spreads between bonds from high- and low-ESG-rated issuers, finding lower yields (by about 10 bps) for high-ESG firms. Our results are robust to additional tests, including controls for endogeneity, and are mainly explained by the environmental and social pillars. We also find that this result is driven by more developed financial markets, likely affected by lower information frictions, and by countries where bankruptcy rules guarantee higher protection for bondholders, making them more willing to grant ESG premia. Finally, we observe lower yield spreads for bond issues that occurred after the introduction of the SFDR, highlighting the importance of regulations promoting socially responsible investments. Overall, our results suggest that firms can benefit from superior ESG performance in the form of lower borrowing costs in the corporate bond market
Microwave heating promotes the S-alkylation of aziridine catalyzed by molecular sieves: A post-synthetic approach to lanthionine-containing peptides
Get PDFAziridine derivatives involved in nucleophilic ring-opening reactions have attracted great interest, since they allow the preparation of biologically active molecules. A chemoselective and mild procedure to convert a peptide cysteine residue into lanthionine via S-alkylation on aziridine substrates is presented in this paper. The procedure relies on a post-synthetic protocol promoted by molecular sieves to prepare lanthionine-containing peptides and is assisted by microwave irradiation. In addition, it represents a valuable alternative to the stepwise approach, in which the lanthionine precursor is incorporated into peptides as a building block
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