37 research outputs found
Spectroscopic Engineering toward Near-Infrared Absorption of Materials Containing Perylene Diimide
The ability to tune the dye structure synthetically has been crucial in the development of materials with tailored properties for given applications. In this contribution, a series of discrete molecules are reported, which are constructed from the perylene diimide (PDI) chromophore and three dyes, namely thienyl diketopyrrolopyrrole (DPPTh2), pyridyl diketopyrrolopyrrole (DPPPyr2), and thienoisoindigo (TII). Through the choice of dye molecule and linking of the dye and PDI through conjugated acetylene bridges, the light-harvesting characteristics can be engineered to exhibit optical absorption in the range 300ā900ā
nm. Each molecule shows ambipolar redox behavior, leading to unique electrochromic behavior
The Optimization of Direct Heteroarylation and Sonogashira Cross-Coupling Reactions as Efficient and Sustainable Synthetic Methods To Access Ļ-Conjugated Materials with Near-Infrared Absorption
Two Ļ-conjugated thienoisoindigo-based organic small molecules have been designed to be synthetically accessible through sustainable direct heteroarylation or Sonogashira CāC bond forming cross-coupling reactions utilizing a heterogeneous palladium catalyst. To access these materials, one molecule, TII-ThNaph2, contains a thiophene Ļ-bridge to facilitate direct heteroarylation protocols, whereas the other, TII-AcNaph2, contains an acetylene Ļ-bridge required for Sonogashira couplings. The synthetic route to both final materials was optimized to investigate the reactivity of thienoisoindigo, which to this point has not been significantly explored in comparison to other popular organic dyes such as diketopyrrolopyrrole and isoindigo. Considering the reported interest of thienoisoindigo-based materials in organic solar cells and field-effect transistors, both final materials have been characterized for their optical, electrochemical and thermal properties offering a comparison of the structureāproperty relationships that manifest as a result of the two different Ļ-bridging units
Hydrous Carbonatitic Liquids Drive CO2 Recycling From Subducted Marls and Limestones
This research was supported by the Italian Ministry of Education, University, and Research (MIUR) program PRIN2017 and by the Deep Carbon Observatory (DCO). We are greatly indebted to Andrea Risplendente for careful examination of run charges at the Electron Microprobe.Pelagic limestones are subducted in a variety of subduction zones worldwide. Despite the geochemical relevance
of systems enriched in CaCO3, previous experimental investigations mostly focused on carbonated pelites, with
low Ca/(Ca+Mg+Fe) ratio. We present the compositions and the formation conditions of liquids in the model
system CaOāAl2O3āSiO2āH2OāCO2 (CASHC), building on phase relationships in the subsystems CHC and
CSHC, where a second critical endpoint was suggested at temperatures as low as 515 Ā°C, and 3.2 GPa. Multianvil
experiments were performed at 4.2 and 6.0 GPa on five bulk compositions at variable Ca/Si/Al ratios. H2O
contents
vary from 5.6 to 21 wt%. Aragonite + kyanite + vapor and minor lawsonite form at 700 Ā°C, replaced by
zoisite/grossular at 800 Ā°C. Between 850 Ā°C and 950 Ā°C, a complex sequence of textural features is observed
upon quenching of a single volatileārich liquid phase formed at run conditions. Precipitates include dendritic
CaCO3, silicate glass, and Alārich whiskers. The bulk composition of such hydrous carbonatitic liquids is
retrieved by image analysis on Xāray maps, showing Ca/Si ratio increasing with pressure and temperature.
Hydrous Caācarbonatitic liquids are efficient media for scavenging volatiles from subducted crustal material and
for metasomatizing the mantle wedge.Ministry of Education, Universities and Research (MIUR)Deep Carbon Observatory (DCO
Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial
Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; pā=ā0.40). There was no significant effect of DMF on any secondary outcome
A preliminary investigation of the anomalous out-of plane tilt alignment in an orthogonal-twist ferroelectric liquid-crystal cell using the prism-coupling technique
Recent prism-coupling results are presented which clearly demonstrate that in ferroelectric liquid crystal cells, prepared with the alignment directions of the two surfaces orthogonal, with sputtered indium tin oxide conductive layers and spun polyimide alignment layers, there is no out-of-plane tilt of the liquid crystal optic axis. Unlike most techniques which give an integrated optical response throughout a cell, the prism-coupling technique allows a separate analysis of in-plane and out-of-plane tilt. Conventional optical polarized microscopy yields good lateral resolution but poor section resolution. For a uniform sample we can obtain information on the section (across the cell) resolution. We report that an optical dielectric tensor configuration is formed in which the major optic axis lies in the plane of the surface across the cell, but that as expected, in an orthogonal-twist cell, there is no axis of preferred alignment within this surface plane
Effects of Molecular Crowding on Protein Self-Association: A Potential Source of Error in Sedimentation Coefficients Obtained by Zonal Ultracentrifugation in a Sucrose Gradient
Theoretical and experimental studies have illustrated a potential source of error in sedimentation coefficients obtained by sucrose density gradient centrifugation of proteins undergoing reversible self association. The error stems from the excluded volume (molecular crowding) effect of the sucrose on the activity coefficients of monomeric and polymeric states. The consequent displacement of the equilibrium position in favor of polymeric state(s) is a function of sucrose concentration, and can therefore result in failure to detect the equilibrium coexistence of monomer if 5% sucrose suffices to displace the equilibrium completely toward dimer. In less extreme situations, it may result in the evaluation of an average sedimentation coefficient whose magnitude is a function of sucrose concentration and hence of the distance migrated into the sucrose gradient. These features are illustrated by the results of computer-simulated sedimentation of reversibly dimerizing systems in a sucrose gradient, and by conventional sedimentation velocity experiments on yeast enolase
Calcium-binding properties and molecular organization of bradykinin. A solution 1H-NMR study
Holocene distribution and amino acid racemisation of the benthic foraminifer Massilina milletti
Addendum to the Geological Society's "Statement on Climate Change: Evidence from the Geological Record"
The Geological Society published a Statement on 'Climate Change: Evidence from the Geological Record' in November 2010. In light of further research that has been published since then, the Geological Society reconvened the expert working group that drafted the 2010 Climate Change Statement to consider whether it was still fit for purpose, and if necessary to amend or add to it.
The working group and Council have concluded that the 2010 Climate Change Statement continues to be valid, and does not need to be amended. Instead, the working group has produced an addendum setting out new research findings relevant to the questions raised in the original statement