38 research outputs found
Half a century of amyloids: past, present and future
Amyloid diseases are global epidemics with profound health, social and economic implications and yet remain without a cure. This dire situation calls for research into the origin and pathological manifestations of amyloidosis to stimulate continued development of new therapeutics. In basic science and engineering, the cross-Ă architecture has been a constant thread underlying the structural characteristics of pathological and functional amyloids, and realizing that amyloid structures can be both pathological and functional in nature has fuelled innovations in artificial amyloids, whose use today ranges from water purification to 3D printing. At the conclusion of a half century since Eanes and Glenner's seminal study of amyloids in humans, this review commemorates the occasion by documenting the major milestones in amyloid research to date, from the perspectives of structural biology, biophysics, medicine, microbiology, engineering and nanotechnology. We also discuss new challenges and opportunities to drive this interdisciplinary field moving forward. This journal i
A Theoretical Study of the Relationship between the Electrophilicity Ï Index and Hammett Constant Ïp in [3+2] Cycloaddition Reactions of Aryl Azide/Alkyne Derivatives
The relationship between the electrophilicity Ï index and the Hammett constant Ïp has been studied for the [2+3] cycloaddition reactions of a series of para-substituted phenyl azides towards para-substituted phenyl alkynes. The electrophilicity Ï indexâa reactivity density functional theory (DFT) descriptor evaluated at the ground state of the moleculesâshows a good linear relationship with the Hammett substituent constants Ïp. The theoretical scale of reactivity correctly explains the electrophilic activation/deactivation effects promoted by electron-withdrawing and electron-releasing substituents in both azide and alkyne components
Retrospective analysis and version improvement of the satellite-based drought composite index. A semi-arid Tensift-Morocco application
Catalytic abatement of dichloromethane over transition metal oxide catalysts:thermodynamic modelling and experimental studies
Abstract
Dichloromethane (DCM) is a noxious chemical that is widely used in industry. The current work focuses on the catalytic abatement of DCM from industrial effluents to minimize its harmful effects to the environment and human wellbeing. Three transition metal oxide catalysts (V, Cu and Mn) supported on Îł-AlâOâ were synthetized for total oxidation of DCM in presence of steam. Thermodynamic modelling was used to reveal information related to the stability of the used transition metal oxides in the abatement conditions. The results showed that with 10âŻwt-% CuO and 10âŻwt-% VâOâ
containing catalysts 100% conversion of DCM together with 90% HCl yield and insignificant by-product formation can be achieved at temperature around 500âŻÂ°C. According to modelling, VâOâ
should be stable at the conditions of DCM oxidation, while CuO would be more stable at higher temperature level (decomposition of CuClâ starts at 300âŻÂ°C). MnClâ remains stable until 800âŻÂ°C, which leads to deactivation of MnOâ catalyst. Presence of steam inhibits the poisoning of the materials by chlorine based on thermodynamic calculation. XRF analysis supports the results of thermodynamic modelling â used MnOâ and CuO catalysts contain chlorine, which was not detected in case of VâOâ
/AlâOâ. CuO/Îł-AlâOâ seems to be a good alternative to noble metal catalysts for the total oxidation of dichloromethane when used in the presence of steam and the temperatures above 300âŻÂ°C to minimize Cl-poisoning. The outcomes of this study showed that the prepared metal oxides are promising catalysts to minimize pollution caused by chlorinated volatile organic compounds