46 research outputs found
Toxicity of lunar dust
The formation, composition and physical properties of lunar dust are
incompletely characterised with regard to human health. While the physical and
chemical determinants of dust toxicity for materials such as asbestos, quartz,
volcanic ashes and urban particulate matter have been the focus of substantial
research efforts, lunar dust properties, and therefore lunar dust toxicity may
differ substantially. In this contribution, past and ongoing work on dust
toxicity is reviewed, and major knowledge gaps that prevent an accurate
assessment of lunar dust toxicity are identified. Finally, a range of studies
using ground-based, low-gravity, and in situ measurements is recommended to
address the identified knowledge gaps. Because none of the curated lunar
samples exist in a pristine state that preserves the surface reactive chemical
aspects thought to be present on the lunar surface, studies using this material
carry with them considerable uncertainty in terms of fidelity. As a
consequence, in situ data on lunar dust properties will be required to provide
ground truth for ground-based studies quantifying the toxicity of dust exposure
and the associated health risks during future manned lunar missions.Comment: 62 pages, 9 figures, 2 tables, accepted for publication in Planetary
and Space Scienc
Inhibition of the ROS-mediated cytotoxicity and genotoxicity of nano-TiO2 toward human keratinocyte cells by iron doping
Silica nanoparticles induce lung inflammation in mice via ROS/PARP/TRPM2 signaling-mediated lysosome impairment and autophagy dysfunction
Background
Wide applications of nanoparticles (NPs) have raised increasing concerns about safety to humans. Oxidative stress and inflammation are extensively investigated as mechanisms for NPs-induced toxicity. Autophagy and lysosomal dysfunction are emerging molecular mechanisms. Inhalation is one of the main pathways of exposing humans to NPs, which has been reported to induce severe pulmonary inflammation. However, the underlying mechanisms and, more specifically, the interplays of above-mentioned mechanisms in NPs-induced pulmonary inflammation are still largely obscure. Considered that NPs exposure in modern society is often unavoidable, it is highly desirable to develop effective strategies that could help to prevent nanomaterials-induced pulmonary inflammation.
Results
Pulmonary inflammation induced by intratracheal instillation of silica nanoparticles (SiNPs) in C57BL/6 mice was prevented by PJ34, a poly (ADP-ribose) polymerase (PARP) inhibitor. In human lung bronchial epithelial (BEAS-2B) cells, exposure to SiNPs reduced cell viability, and induced ROS generation, impairment in lysosome function and autophagic flux. Inhibition of ROS generation, PARP and TRPM2 channel suppressed SiNPs-induced lysosome impairment and autophagy dysfunction and consequent inflammatory responses. Consistently, SiNPs-induced pulmonary inflammation was prevented in TRPM2 deficient mice.
Conclusion
The ROS/PARP/TRPM2 signaling is critical in SiNPs-induced pulmonary inflammation, providing novel mechanistic insights into NPs-induced lung injury. Our study identifies TRPM2 channel as a new target for the development of preventive and therapeutic strategies to mitigate nanomaterials-induced lung inflammation
The alarmin IL-1α is a master cytokine in acute lung inflammation induced by silica micro- and nanoparticles
Le figure retoriche. Parola e immagine
Il volume propone una rilettura delle figure retoriche secondo una nuova impostazione teorica e didattica, rivolta all’individuazione del procedimento, ovvero dei meccanismi logici profondi da cui sono generate le varie figure. Punto di forza del volume è la costante attenzione alle diverse forme di linguaggio -verbale e iconico- con esemplificazioni tratte dalla scrittura letteraria e da altre forme di comunicazione. Si segnala, a livello più specificamente critico-letterario, l’antologia stilistica che chiude ogni sezione, in cui sono riportati esempi di interpretazione di testi, in cui vengono usate le figure retoriche come chiave di lettura ermeneutica
Constitutional isomerism in heterocycles: A structural revision of benzofused isothiazoles
During investigations on our deaminative chlorination protocol, a misassignment between two constitutional isomers of a benzofused isothiazole was encountered. Herein, we provide a clue game in order to identify the correct structure of the reported molecule as well as an investigation on the origin of the error. Finally, a revised synthesis of the previously published examples was proposed to provide the practitioners reliable data en route to reproducible science
Bio-Inspired Deaminative Hydroxylation of Aminoheterocycles and Electron-Deficient Anilines
Among the tools available to chemists for drug design of bioactive compounds, the bioisosteric replacement of atoms or groups of atoms is the cornerstone of modern strategies. Despite the undeniable interest in amino-to-hydroxyl interchange, enzymatic deaminative hydroxylation remains unmatched. Herein, we report a user friendly and safe procedure to selectively convert aminoheterocycles to their hydroxylated analogues by means of a simple pyrylium tetrafluoroborate salt. The hydroxylation step relies on a Lossen-type rearrangement under mild conditions thus avoiding the use of strong hydroxide bases. In addition to biorelevant heterocycles, the deaminative hydroxylation of electron-deficient anilines was also demonstrated. Finally, mechanistic experiments allowed the identification of the key intermediates, thus unveiling a rather unusual mechanism for this formal aromatic substitution
Co-digestion of municipal sewage sludges and pre hydrolysed woody agricultural wastes
Material balance has been used to evaluate the COD behaviour and the time required for fed-batch digestion of mixtures of domestic sludges and pre-hydrolysed agricultural wastes