Catalytically active and thermally stable core-shell gold-silica nanorods for CO oxidation

Deactivation based on sintering phenomena is one of the most costly issues for the industrial application of metal nanoparticle catalysts. To address this drawback, mesoporous silica encapsulation is reported as a promising strategy to stabilize metallic nanoparticles towards use in high temperature catalytic applications. These protective shells provide significant structural support to the nanoparticles, while the mesoporosity allows for efficient transport of the reactants to the catalytically active surface of the metallic nanoparticle in the core. Here, we extend the use of gold nanorods with mesoporous silica shells by investigating their stability in the CO oxidation reaction as an example of high temperature gas phase catalysis. Gold nanorods were chosen as the model system due to the availability of a simple, high yield synthesis method for both the metallic nanorods and the mesoporous silica shells. We demonstrate the catalytic activity of gold nanorods with mesoporous silica shells at temperatures up to 350 degrees C over several cycles, as well as the thermal stability up to 500 degrees C, and compare these results to surfactant-stabilized gold nanorods of similar size, which degrade, and lose most of their catalytic activity, before reaching 150 degrees C. These results show that the gold nanorods protected by the mesoporous silica shells have a significantly higher thermal stability than surfactant-stabilized gold nanorods and that the mesoporous silica shell allows for stable catalytic activity with little degradation at high temperatures

Plasma Cleaning of Cationic Surfactants from Pd Nanoparticle Surfaces: Implications for Hydrogen Sorption

Cationic surfactants are widely used in the colloidal synthesis of noble metal nanoparticles in general, and of Pd nanoparticles in particular, to stabilize them toward aggregate formation in solution and to promote shape-specific particle growth. Despite the benefits at the synthesis stage, these surfactants can be problematic once the nanoparticles are to be applied as they may both geometrically block and electronically alter surface sites that are important for surface chemical reactions. This is particularly relevant in applications like bio- and chemosensors where analyte-nanoparticle surface interactions constitute the actual sensing event. Here, H2 sensors based on Pd and its alloys are no exception since the dissociation of H2 on the particle surface is the first step toward hydride formation and thus hydrogen detection, and it has been demonstrated that the presence of surfactant molecules detrimentally affects the hydrogen sorption rate. Here, we therefore develop a scheme to remove cationic surfactants from Pd nanoparticle surfaces by means of subsequent O2 and H2 plasma treatment, whose effectiveness we verify by X-ray photoelectron spectroscopy. Furthermore, we find that the plasma treatment both alters the surface structure of the Pd nanoparticles at the atomic level and leads to surface contamination by so-called H2 plasma swift chemical sputtering of Al, Si and F species present in the plasma chamber, which in combination significantly reduce hydrogen sorption rates and increase apparent activation energies, as revealed by plasmonic hydrogen sorption kinetic measurements. Finally, we show that both these effects can be reversed by mild thermal annealing and that after the complete plasma cleaning-thermal annealing sequence hydrogen sorption rates essentially identical to the ones of neat Pd particles never exposed to cationic surfactants can be achieved. This advertises tailored plasma cleaning and mild heat treatments as an effective recipe for the removal of surfactant molecules from nanoparticle surfaces

Solar Energy Storage by Molecular Norbornadiene–Quadricyclane Photoswitches:Polymer Film Devices

Devices that can capture and convert sunlight into stored chemical energy are attractive candidates for future energy technologies. A general challenge is to combine efficient solar energy capture with high energy densities and energy storage time into a processable composite for device application. Here, norbornadiene (NBD)–quadricyclane (QC) molecular photoswitches are embedded into polymer matrices, with possible applications in energy storing coatings. The NBD–QC photoswitches that are capable of absorbing sunlight with estimated solar energy storage efficiencies of up to 3.8% combined with attractive energy storage densities of up to 0.48 MJ kg −1 . The combination of donor and acceptor units leads to an improved solar spectrum match with an onset of absorption of up to 529 nm and a lifetime (t 1/2 ) of up to 10 months. The NBD–QC systems with properties matched to a daily energy storage cycle are further investigated in the solid state by embedding the molecules into a series of polymer matrices revealing that polystyrene is the preferred choice of matrix. These polymer devices, which can absorb sunlight and over a daily cycle release the energy as heat, are investigated for their cyclability, showing multicycle reusability with limited degradation that might allow them to be applied as window laminates

Solar energy storage at an atomically defined organic-oxide hybrid interface

Molecular photoswitches provide an extremely simple solution for solar energy conversion and storage. To convert stored energy to electricity, however, the photoswitch has to be coupled to a semiconducting electrode. In this work, we report on the assembly of an operational solar-energy-storing organic-oxide hybrid interface, which consists of a tailor-made molecular photoswitch and an atomically-defined semiconducting oxide film. The synthesized norbornadiene derivative 2-cyano-3-(4-carboxyphenyl)norbornadiene (CNBD) was anchored to a well-ordered Co3O4(111) surface by physical vapor deposition in ultrahigh vacuum. Using a photochemical infrared reflection absorption spectroscopy experiment, we demonstrate that the anchored CNBD monolayer remains operational, i.e., can be photo-converted to its energy-rich counterpart 2-cyano-3-(4-carboxyphenyl)quadricyclane (CQC). We show that the activation barrier for energy release remains unaffected by the anchoring reaction and the anchored photoswitch can be charged and discharged with high reversibility. Our atomically-defined solar-energy-storing model interface enables detailed studies of energy conversion processes at organic/oxide hybrid interfaces

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; p = 0.40). There was no significant effect of DMF on any secondary outcome

The effect of comprehensive geriatric assessment on care received, treatment completion, toxicity, cancer-related and geriatric assessment outcomes, and quality of life for older adults receiving systemic anti-cancer treatment: A systematic review

Introduction: This systematic review aims to summarise the available literature on the effect of geriatric assessment (multidimensional health assessment across medical, social, and functional domains; “GA”) or comprehensive geriatric assessment (geriatric assessment with intervention or management recommendations; “CGA”) compared to usual care for older adults with cancer on care received, treatment completion, adverse treatment effects, survival and health-related quality of life. Materials and Methods: A systematic search of MEDLINE, EMBASE, CINAHL, and PubMed was conducted to identify randomised controlled trials or prospective cohort comparison studies on the effect of GA/CGA on care received, treatment, and cancer outcomes for older adults with cancer. Results: Ten studies were included: seven randomised controlled trials (RCTs), two phase II randomised pilot studies, and one prospective cohort comparison study. All studies included older adults receiving systemic therapy, mostly chemotherapy, for mixed cancer types (eight studies), colorectal cancer (one study), and non-small cell lung cancer (one study). Integrating GA/CGA into oncological care increased treatment completion (three of nine studies), reduced grade 3+ chemotherapy toxicity (two of five studies), and improved quality of life scores (four of five studies). No studies found significant differences in survival between GA/CGA and usual care. GA/CGA incorporated into care decisions prompted less intensive treatment and greater non-oncological interventions, including supportive care strategies. Discussion: GA/CGA integrated into the care of an older adult with cancer has the potential to optimise care decisions, which may lead to reduced treatment toxicity, increased treatment completion, and improved health-related quality of life scores.</p

Norbornadiene-Based Photoswitches with Exceptional Combination of Solar Spectrum Match and Long-Term Energy Storage

Norbornadiene-quadricyclane (NBD-QC) photoswitches are candidates for applications in solar thermal energy storage. Functionally, they rely on an intramolecular [2+2] cycloaddition reaction, which couples the S0 landscape on the NBD side to the S1 landscape on the QC side of the reaction and vice-versa. This commonly results in an unfavourable correlation between the first absorption maximum and the barrier for thermal back-conversion. This work demonstrates that this correlation can be counteracted by using steric repulsion to hamper the rotational motion of the side groups along the back-conversion path. It is shown that this modification reduces the correlation between the effective back-conversion barrier and the first absorption maximum and also increases the back-conversion entropy. The resulting molecules exhibit exceptionally long half-lives for their metastable forms without significantly affecting other properties, most notably solar spectrum match and storage density

Older adults' preferred and perceived roles in decision-making about palliative chemotherapy, decision priorities and information preferences

Aim: Patients with cancer have varied preferences for involvement in decision-making. We sought older adults' preferred and perceived roles in decision-making about palliative chemotherapy; priorities; and information received and desired. Methods: Patients ≥65y who had made a decision about palliative chemotherapy with an oncologist completed a written questionnaire. Preferred and perceived decision-making roles were assessed by the Control Preferences Scale. Wilcoxon rank-sum tests evaluated associations with preferred role. Factors important in decision-making were rated and ranked, and receipt of, and desire for information was described. Results: Characteristics of the 179 respondents: median age 74y, male (64%), having chemotherapy (83%), vulnerable (Vulnerable Elders Survey-13 score ≥ 3) (52%). Preferred decision-making roles (n = 173) were active in 39%, collaborative in 27%, and passive in 35%. Perceived decision-making roles (n = 172) were active in 42%, collaborative in 22%, and passive in 36% and matched the preferred role for 63% of patients. Associated with preference for an active role: being single/widowed (p = .004, OR = 1.49), having declined chemotherapy (p = .02, OR = 2.00). Ranked most important (n = 159) were “doing everything possible” (30%), “my doctor's recommendation” (26%), “my quality of life” (20%), and “living longer” (15%). A minority expected chemotherapy to cure their cancer (14%). Most had discussed expectations of cure (70%), side effects (88%) and benefits (82%) of chemotherapy. Fewer had received quantitative prognostic information (49%) than desired this information (67%). Conclusion: Older adults exhibited a range of preferences for involvement in decision-making about palliative chemotherapy. Oncologists should seek patients' decision-making preferences, priorities, and information needs when discussing palliative chemotherapy

Sulindac Derivatives That Activate the Peroxisome Proliferator-activated Receptor γ but Lack Cyclooxygenase Inhibition

A series of novel derivatives of the nonsteroidal anti-inflammatory drug (NSAID) sulindac sulfide were synthesized as potential agonists of the peroxisome proliferator-activated receptor gamma (PPARγ). Nonpolar and aromatic substitutions on the benzylidene ring as well as retention of the carboxylic acid side chain were required for optimal activity. Compound <b>24</b> was as potent a compound as any other in the series with an EC₅₀ of 0.1 μM for the induction of peroxisome proliferator response element (PPRE)-luciferase activity. Direct binding of compound <b>24</b> to PPARγ was demonstrated by the displacement of [³H]troglitazone, a PPARγ agonist, in a scintillation proximity assay. Compound <b>24</b> also stimulated the binding of PPARγ to a PPRE-containing oligonucleotide and induced expression of liver fatty-acid binding protein (L-FABP) and adipocyte fatty acid-binding protein (aP2), two established PPARγ target genes. Taken together, these compounds represent potential leads in the development of novel PPARγ agonists