Controlling the Structure, Properties and Surface Reactivity of Clickable Azide-Functionalized Au (SR) Nanocluster Platforms Through Regioisomeric Ligand Modifications. | LitMetric
Department of Chemistry and Centre for Advanced Materials and Biomaterials Research, Western University London, Ontario, N6A 5B7, Canada.
Published: July 2022
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Article Abstract
To fine-tune structure-property correlations of thiolate-protected gold nanoclusters through post-assembly surface modifications, we report the synthesis of the o, m, and p regioisomeric forms of the anionic azide-functionalized [Au (SCH CH -C H -N ) ] platform. They can undergo cluster-surface strain-promoted alkyne-azide cycloaddition (CS-SPAAC) chemistry with complementary strained-alkynes. Although their optical properties are similar, the electrochemical properties appear to correlate with the position of the azido group. The ability to conduct CS-SPAAC chemistry without altering the parent nanocluster structure is different as the isomeric form of the surface ligand is changed, with the [Au (SCH CH -p-C H -N ) ] isomer having the highest reaction rates, while the [Au (SCH CH -o-C H -N ) ] isomer is not stable following CS-SPAAC. Single-crystal X-ray diffraction provide the molecular structure of the neutral forms of the three regioisomeric clusters, [Au (SCH CH -o/m/p-C H -N ] , which illustrates correlated structural features of the central core as the position of the azido moiety is changed.
Interactions between magma oceans and overlying atmospheres on young rocky planets leads to an evolving feedback of outgassing, greenhouse forcing, and mantle melt fraction. Previous studies have predominantly focused on the solidification of oxidized Earth-similar planets, but the diversity in mean density and irradiation observed in the low-mass exoplanet census motivate exploration of strongly varying geochemical scenarios. We aim to explore how variable redox properties alter the duration of magma ocean solidification, the equilibrium thermodynamic state, melt fraction of the mantle, and atmospheric composition.
Purpose: To summarise the extent and type of evidence in relation to adverse events (AEs) associated with the use of cannabis-based products (CBP) in people living with cancer.
Methods: The Joanna Briggs Institute (JBI) methodology for scoping reviews was applied. A search was performed in MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), Scopus, Web of Science Core Collections and AMED (Ovid) from their inception to 7 May 2023.
Little is known about the impact of clinician discontinuity on quality of care for nursing home residents. We examined the association between clinician discontinuity and outcomes of residents with long-term care stays up to 3 years using claims for a national 20% sample of Medicare fee-for-service beneficiaries from 2014 through 2019. We used an event study analysis that accounted for staggered treatment timing.
The world is nearing the critical threshold of 1.5°C warming, with 2023 recording an average temperature rise of 1.45°C since pre-industrial times, leading to severe climate-related impacts.
The Countdown collaboration, formed to assess the health impacts of climate change post-Paris Agreement, involves over 300 experts analyzing data and trends annually.
The 2024 report highlights troubling increases in climate-related health risks, such as a staggering 167% rise in heat-related deaths among seniors, indicating worsening conditions affecting wellbeing globally.
Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Science, Institute WUT-AMU, Wuhan University of Technology, Wuhan 430070, China.
Targeting Parkinson's disease (PD) related protein, α-synuclein (αS), via gold nanoclusters (AuNCs) has received considerable attention in PD treatments, but its molecular basis on the initial interactions between αS and AuNCs remains elusive due to the absence of a unique secondary structure of αS chains. Here, at the single-cluster level, we incorporate well-tempered metadynamics simulations to explore the structural and thermodynamic characteristics of the full length αS adsorbed on different-sized AuNCs (Au, = 25, 36, 44, 68, 102) with modeled thiolated ligands (Au@Lig). The conformational landscapes of αS indicate that uncharged Au@SCHOH chaperones the native intrinsically disordered conformations of αS, while negatively and positively charged AuNCs greatly increase the likelihood of forming intramolecular β-sheet domains, which are necessary for αS fibrillation and are a hallmark of PD.
