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Rosario Moser posted an update 9 hours, 57 minutes ago
Herein, the absorption and oxidation reactions of SO2 on TiO2 nanoparticles (TiO2 NPs) at 296 K under various environmental conditions (humidity, UV irradiation, and ozone copresence) were investigated by using a flow chamber reaction system, synchrotron X-ray absorption near-edge structure (XANES) and high resolution synchrotron X-ray photoelectron spectroscopy (XPS) measurements. The results showed that oxidation of SO2 to sulfate via TiO2 NP catalysis happened at a very rapid rate. The appropriate relative humidity, UV irradiation and co-presence of ozone all markedly promoted SO2 oxidation on TiO2 NPs. High resolution XPS unraveled that the terminal hydroxyl (OHt) and oxygen vacancy (VO)-Ti3+ states on TiO2 NPs were the active sites for SO2 adsorption and oxidation. The data of XPS measurements suggest that SO2 was adsorbed on a OHt next to a Ti3+ VO and reacted to form HSO3-. HSO3- can then transform into SO32-via transfer of a proton. The resulting adsorbed SO32- could bind to a surface bridging O (Ob) atom and transform into SO42-. A H2O molecule could dissociate on VO-Ti3+ into two bridging hydroxyl (OHb) groups, subsequently forming new Ob, which provides an active O site for the adsorbed HSO3-/SO32- and oxidizes them into HSO4-/SO42- on the surface of the TiO2 NPs. The copresence of O3 could promote H2O dissociation into OHb, promoting the formation of Ob. The copresence of O3 may also promote the dissociation of adsorbed H2O into TiO2-O2- and hydroxyl radicals (˙OH) on VOs, facilitating the oxidation of adsorbed HSO3-/SO32-. Under UV irradiation, new VOs were created via oxidation of lattice O by photo-generated holes, resulting in increased Ob and subsequently enhanced oxidation of adsorbed HSO3-/SO32- on TiO2 NPs.Employing neutron spectroscopy, we follow the tracer diffusion of two non-steroidal anti-inflammatory drug molecules, paracetamol (PCM) and ibuprofen sodium (IBU), in a supramolecular gel and the corresponding bulk solution. Both solutes show altered diffusion behaviour in the gel phase, deviating from each other and their bulk solution. Whilst picosecond diffusion of IBU is slightly quicker in the gel, this effect is significantly increased for PCM, which is up to 70% quicker in the gel than in solution. This effect is independent of changes in the solvent diffusion reported previously. An increased residence time of PCM in solution at lower temperatures points towards the onset of nucleation and crystallisation. This work reports one of the first experiments on the novel Backscattering and Time-of-Flight option (BATS) on the IN16B spectrometer at the Institut Laue-Langevin, France, which with its range and resolution in neutron energy and momentum transfer is ideally suited to observe this type of diffusion.Antimicrobial peptides are believed to be promising bio-preservatives to prevent microbial spoilage through food processing and preservation. Selleckchem L-NMMA With the aim of developing short peptides with broad-spectrum antimicrobial activity and revealing their potential antimicrobial mechanism, a novel class of dodecapeptides were designed by introducing Trp into the hydrophilic face of RI12, a truncated α-helical peptide of porcine myeloid antimicrobial peptide-36 (PMAP-36). The antimicrobial activity study indicated that Trp endowed the peptides with higher antimicrobial potency, and the net charge of +5 was sufficient for the dodecapeptides to exert antimicrobial action. Taking hemolytic activity into consideration, the most promising peptide RI12[K3W] (RLWKIGKVLKWI-NH2) was screened with high antimicrobial activity and non-toxicity. The antimicrobial mechanism study revealed that RI12[K3W] possessed the ability to bind to LPS components and enhance membrane permeability, which was verified by membrane penetration assays. Flow cytometry and electron microscopy further confirmed that RI12[K3W] killed bacterial cells primarily by membrane damage. The results guide the potential application of antimicrobial peptides in the food industry as food preservatives to prevent bacterial contamination.Early theoretical and experimental investigations of inorganic sulfur-nitrogen compounds were dominated by (a) assessments of the purported aromatic character of cyclic, binary S,N molecules and ions, (b) the unpredictable reactions of the fascinating cage compound S4N4, and (c) the unique structure and properties of the conducting polymer (SN)x. In the last few years, in addition to unexpected developments in the chemistry of well-known sulfur nitrides, the emphasis of these studies has changed to include nitrogen-rich species formed under high pressures, as well as the selenium analogues of well-known S,N compounds. Novel applications have been established or predicted for many binary S/Se,N molecules, including their use for fingerprint detection, in optoelectronic devices, as high energy-density compounds or as hydrogen-storage materials. The purpose of this perspective is to evaluate critically these new aspects of the chemistry of neutral, binary chalcogen-nitrogen molecules and to suggest experimental approaches to the synthesis of target compounds. Recently identified ternary S,N,P compounds will also be considered in light of their isoelectronic relationship with binary S,N cations.Control of biological function by the use of photoremovable protecting groups (PPGs) is a gateway towards many new medical developments. Herein, we report the synthesis and application of efficient and biocompatible BODIPY-based photoprotecting groups for amines, which are cleavable with red light in the phototherapeutic window region (λ > 650 nm). We use the most promising PPG for the protection of dopamine and apply it to control the beating frequency of human cardiomyocytes.Implant-associated infections (IAIs) are one of the leading concerns in orthopedics and dentistry as they commonly lead to implant failure. The presence of biofilms and, increasingly frequently, drug-resistant bacteria further impairs the efficacy of conventional antibiotics. Immobilization of antimicrobial peptides (AMPs) on implant surfaces is a promising alternative to antibiotics for prevention of IAIs. In addition, the use of functional linkers for the AMP tethering enables to increase the antimicrobial potential and the bioactivities of the coating. In this study, an extracellular-matrix-mimicking system based on elastin-like recombinamers (ELRs) has been developed for the covalent anchoring of AMPs and investigated for use as a hybrid antibiofilm coating. A drip-flow biofilm reactor was used to simulate in vivo environmental dynamic conditions, thus showing that the presence of the AMPs in the hybrid coatings provided strong antibiofilm activity against monospecies and microcosm biofilm models of clinical relevance.