Investigating the effects of pyridine and poly(4-vinylpyridine) on CO2 reduction electrocatalysis at gold electrodes using in situ surface-enhanced Raman spectroelectrochemistry.

The CO2 reduction reaction (CO2RR) at metal electrodes is altered in the presence of pyridine and related species. Thick films of poly(4-vinylpyridine) on Au electrodes result in large current enhancements at low applied potentials but do not enhance CO2RR at these potentials. Surface-enhanced Raman spectroelectrochemistry can probe CO2-surface interactions and reveals that desorption of CO2 as bicarbonate is retarded in the presence of 4-PVP, with implications for ion-transport limitations in thick film CO2RR.

Directing the mechanism of CO2 reduction by a Mn catalyst through surface immobilization.

Immobilization of a Mn polypyridyl CO2 reduction electrocatalyst on nanocrystalline TiO2 electrodes yields an active heterogeneous system and also significantly triggers a change in voltammetric and catalytic behaviour, relative to in solution. A combination of spectroelectrochemical techniques are presented here to elucidate the mechanism of the immobilized catalyst in situ.

Photochemical CO2 reduction using structurally controlled g-C3N4.

Graphitic carbon nitride (g-C3N4) synthesised from a urea precursor is an excellent CO2 reduction photocatalyst using [Co(bpy)n]2+ as a co-catalyst. A five-fold increase in activity for the highly polymerised urea derived g-C3N4 is achieved compared to alternative precursors. Transient absorption, time-resolved and steady-state emission studies indicate that the enhanced activity is related to both an increased driving force for photoelectron transfer and a greater availability of photogenerated charges.

Improving the efficiency of electrochemical CO2 reduction using immobilized manganese complexes.

Immobilization of [Mn(bpy)(CO)3Br], (1) and [Mn(bpy((t)Bu)2)(CO)3Br] (2, where (bpy((t)Bu)2) = 4,4'-di-tert-butyl-2,2'-bipyridine) in Nafion/multi-walled carbon nanotubes (MWCNT) on glassy carbon yielded highly active electrodes for the reduction of CO2 to CO in aqueous solutions at pH 7. Films incorporating have significantly improved selectivity towards CO2, with CO : H2 ∼ 1 at -1.4 V vs. SCE, exceeding that for the previously reported /MWCNT/Nafion electrode. Furthermore, we report the synthesis and subsequent electrochemical characterization of two new substituted Mn(i) bipyridine complexes, [Mn(bpy(COOH)2)(CO)3Br] (3) and [Mn(bpy(OH)2)(CO)3Br] (4) (where (bpy(COOH)2) = 4,4'-di-carboxy-2,2'-bipyridine and (bpy(OH)2) = 4,4'-di-hydroxy-2,2'-bipyridine). Both 3 and 4 were found to have some activity towards CO2 in acetonitrile solutions; however once immobilized in Nafion membranes CO2 reduction was found to not occur at significant levels.

A functionalised nickel cyclam catalyst for CO2 reduction: electrocatalysis, semiconductor surface immobilisation and light-driven electron transfer.

The immobilisation of electrocatalysts for CO2 reduction onto light harvesting semiconductors is proposed to be an important step towards developing more efficient CO2 reduction photoelectrodes. Here, we report a low cost nickel cyclam complex covalently anchored to a metal oxide surface. Using transient spectroscopy we validate the role of surface immobilisation on enhancing the rate of photoelectron transfer. Furthermore [Ni(1,4,8,11-tetraazacyclotetradecane-6-carboxylic acid)](2+) (2) is shown to be a very active electrocatalyst in solution.

Electron transfer to covalently immobilized Keggin polyoxotungstates on gold.

Spontaneously adsorbed monolayers have been formed on gold electrodes using a Keggin polyoxotungstate with covalently attached alkanethiol linkers of two different lengths. Films of both polyoxotungstates show two well-defined reduction processes associated with the polyoxotungstate centers where the ionic liquid, [BMIM][BF4], acts as supporting electrolyte. The surface coverages are both less than that expected for a close-packed monolayer. For the short and long linkers, the voltammetric response can be described in terms of the Butler-Volmer response involving a surface confined species using standard heterogeneous electron transfer rate constants of 170 and 140 s(-1) for the first reduction and 150 and 100 s(-1) for the second reduction processes, respectively. The rate of electron transfer to a solution phase redox probe, ferrocyanide, is significantly more sensitive to the length of the linker than the rate of electron transfer to the tungstate centers. This behavior probably arises due to potential-induced changes in the film structure.

Bone Marrow Mesenchymal Stem Cell-Derived Extracellular Vesicle Infusion for the Treatment of Respiratory Failure From COVID-19: A Randomized, Placebo-Controlled Dosing Clinical Trial.

BACKGROUND: Bone marrow mesenchymal stem cell (BM-MSC)-derived extracellular vesicles (ExoFlo) convey the immunomodulatory and regenerative properties of intact BM-MSCs. This study aimed to determine the safety and efficacy of ExoFlo as treatment for moderate to severe ARDS in patients with severe COVID-19. RESEARCH QUESTION: Do two doses of ExoFlo safely reduce mortality in COVID-19-associated moderate to severe ARDS compared with placebo? STUDY DESIGN AND METHODS: A prospective phase 2 multicenter double-anonymized randomized placebo-controlled dosing trial was conducted at five sites across the United States with infusions of placebo, 10 mL of ExoFlo, or 15 mL of ExoFlo on days 1 and 4. Patients (N = 102) with COVID-19-associated moderate to severe ARDS were enrolled and randomized to treatment. Adverse events were documented throughout the study. The primary outcome measure was all-cause 60-day mortality rate. Secondary outcomes included time to death (overall mortality); the incidence of treatment-emergent serious adverse events; proportion of discharged patients at 7, 30, and 60 days; time to hospital discharge; and ventilation-free days. RESULTS: No treatment-related adverse events were reported. Mortality (60-day) in the intention-to-treat population was reduced with 15 mL ExoFlo mixed with 85 mL normal saline (ExoFlo-15) compared with placebo (not significant, χ2, P = .1343). For the post hoc subgroup analyses, 60-day mortality was decreased with ExoFlo-15 compared with placebo (relative risk, 0.385; 95% CI, 0.159-0.931; P = .0340; n = 50). With ExoFlo-15, a relative risk of 0.423 (95% CI, 0.173-1.032; P = .0588; n = 24) was determined for participants aged 18 to 65 years with moderate to severe ARDS. Ventilation-free days improved with ExoFlo-15 (P = .0455; n = 50) for all participants aged 18 to 65 years. INTERPRETATION: The 15 mL dose of ExoFlo was found to be safe in patients with severe or critical COVID-19-associated respiratory failure. In participants aged 18 to 65 years, the risk reduction in 60-day mortality was further improved from subjects of all ages in the intention-to-treat population after two doses of 15 mL of ExoFlo compared with placebo. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT04493242; URL: www. CLINICALTRIALS: gov.

Ruthenium metallopolymer: Dawson polyoxomolybdate α-[Mo18O54(SO4)2]4- adduct films: sensitization for visible photoelectrocatalysis.

Thin films of the adduct formed from the electrostatic association of the metallopolymer, [Ru(bpy)(2)(PVP)(10)](2+), and the Dawson polyoxomolybdate α-[Mo(18)O(54)(SO(4))(2)](4-), POMo, have been formed on ITO electrodes using an alternate immersion approach. The Ru/POMo ratio is 4.5:1, which exceeds the 2:1 ratio expected on the basis of the charges of the Ru(2+) and POMo(4-) building blocks. This behavior arises because of the polymeric character of the cation. In the presence of a substrate that has an abstractable proton such as benzyl alcohol, these ruthenium-sensitized polyoxomolybdate films generate significant photocurrents under visible irradiation. Significantly, increasing the surface coverage of the adduct from 1.4 × 10(-10) to 8.1 × 10(-10) mol cm(-2) does not measurably increase the photocurrent observed. Scan-rate-dependent cyclic voltammetry reveals that the rate of homogeneous charge transport through the film is slow, which most likely results in only a fraction of the film thickness being active for photoelectrocatalysis. The photocurrent increases markedly when the driving force for the oxidation of POMo(5-), created by the photoelectrocatalytic oxidation of benzyl alcohol, is increased. This result is consistent with the dynamics of heterogeneous electron transfer being centrally important to the regeneration of the photoelectrocatalyst. A system in which the surface coverage and applied overpotential are optimized produces a photocurrent density of 190 ± 18 nA cm(-2) under 480 ± 5 nm irradiation.

Highly luminescent Ru(II) metallopolymers: photonic and redox properties in solution and as thin films.

Highly luminescent metallopolymers have been prepared from condensation reactions between the primary alkyl amines contained within a poly(styrene-p-(aminomethyl)styrene) polymer backbone and carboxylic acid groups on [Ru(bpy)(2)(CAIP)](ClO(4))(2), where CAIP is 2-(4-carboxyphenyl)imidazo[4,5-f][1,10]phenanthroline. The photophysical properties of these metallopolymers including emission and absorption spectroscopy, luminescent lifetimes and time-resolved emission anisotropy show strong solvent and pH dependence. These properties are rather insensitive to the loading of the metal centres on the polymer backbone suggesting weak electronic interactions between adjacent centres and the polymer backbone. The polymers form continuous films when drop-cast at an indium tin oxide interface and retain their strong luminescence. This processability and intense luminescence make them potentially useful for sensing and display applications.

Organic-Inorganic Hybrid Films of the Sulfate Dawson Polyoxometalate, [S2W18O62]4-, and Polypyrrole for Iodate Electrocatalysis.

The Dawson-type sulfate polyoxometalate (POM) [S2W18O62]4- has successfully been entrapped in polypyrrole (PPy) films on glassy carbon electrode (GCE) surfaces through pyrrole electropolymerization. Films of varying POM loadings (i.e., thickness) were grown by chronocoulometry. Film-coated electrodes were then characterized using voltammetry, revealing POM surface coverages ranging from 1.9 to 11.7 × 10-9 mol·cm-2, and were stable over 100 redox cycles. Typical film morphology and composition were revealed to be porous using atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy, and the effects of this porosity on POM redox activity were probed using AC impedance. The hybrid organic-inorganic films exhibited a good electrocatalytic response toward the reduction of iodate with a sensitivity of 0.769 µA·cm-2·µM-1.

GP experience and understandings of providing follow-up care in prostate cancer survivors in England.

Survival times for prostate cancer have increased substantially, meaning more survivors will be discharged to General Practitioners' (GP) services. The detection of recurrence and monitoring of symptoms and long-term side-effects in prostate cancer survivors requires the active involvement of GPs in their follow-up care. In order to address this, the transition and discharge from hospital to primary care must be managed effectively. The objective of this study was to examine the preparedness, concerns and experiences of GPs in relation to their role in providing follow-up care to prostate cancer survivors. Purposive sampling was used to recruit GPs with experience in providing care to prostate cancer survivors. Twenty semi-structured telephone interviews were conducted with GPs across England. The interviews were audio-recorded, transcribed verbatim and analysed using thematic analysis. Participants described their current role in the follow-up pathway, a number of challenges and barriers in assuming this role, and potential ways to resolve these and improve their involvement. They expressed a range of views about their preparedness and willingness to take over follow-up care after discharge for this group of patients. GPs had reservations about workload, lack of resources, expertise and deficiencies in communication with hospitals. Findings from this study suggest that GPs will be ready to take over the follow-up care of prostate cancer survivors if better information, additional training and adequate resources are provided and communication lines with hospital specialists are clear. Understanding the issues faced by GPs and overcoming identified barriers to providing follow-up care to prostate cancer survivors will provide the insight necessary to make the process of transferring care from secondary to primary teams a more straightforward task for all stakeholders.

A case of naturally acquired inhalation anthrax: clinical care and analyses of anti-protective antigen immunoglobulin G and lethal factor.

This report describes the first case of naturally acquired inhalation anthrax in the United States since 1976. The patient's clinical course included adjunctive treatment with human anthrax immunoglobulin. Clinical correlation of serologic assays for the lethal factor component of lethal toxin and anti-protective antigen immunoglobulin G are also presented.

A highly active nickel electrocatalyst shows excellent selectivity for CO2 reduction in acidic media.

The development of selective electrocatalysts for CO2 reduction in water offers a sustainable route to carbon based fuels and feedstocks. However, molecular catalysts are typically studied in non-aqueous solvents, in part to avoid competitive H2 evolution. [Ni(cyclam)]2+ (1) is one of the few known electrocatalysts that operate in water and 30 years after its report its activity remains a rarely surpassed benchmark. Here we report that [Ni(cyclam-CO2H)]2+ (cyclam-CO2H = 1,4,8,11-tetraazacyclotetradecane-6-carboxylic acid (2)) shows greatly enhanced activity versus1 for CO production. At pHs < pKa of the pendant carboxylic acid a large increase in catalytic activity occurs. Remarkably, despite the high proton concentration (pH 2), 2 maintains selectivity for CO2 reduction and is believed to be unique in operating selectively in such acidic aqueous solutions.

Photochemical CO2 reduction in water using a co-immobilised nickel catalyst and a visible light sensitiser.

A dye-sensitised CO2 reduction photocatalyst that operates in water is reported. Transient spectroscopy demonstrates that the facile co-immobilisation of a Ru dye and a Ni CO2 reduction electrocatalyst enables efficient on-particle electron transfer leading to photocatalytic activity that greatly exceeds the equivalent solution based system.

Interpretive bias, repressive coping, and trait anxiety.

OBJECTIVES: According to vigilance-avoidance theory, repressors have an avoidant interpretive bias, i.e., they interpret ambiguous self-relevant situations in a nonthreatening fashion. This study sought to demarcate the range of situations associated with avoidant interpretive bias in repressors. DESIGN: Four groups of participants, representing the four combinations of low- and high-trait anxiety and defensiveness, were identified. Those low in trait anxiety and high in defensiveness were categorized as repressors. METHODS: Participants (N = 163) rated their likelihood of making both threatening and nonthreatening interpretations of 32 ambiguous scenarios over four domains: social, intellectual, physical, and health. Half the scenarios were self-relevant and half were other relevant. Brief measures of state anxiety were taken after each likelihood rating. RESULTS: Repressors displayed an avoidant interpretive bias for ambiguous threats in the social and intellectual domains but not the health or physical domains. This was due to repressors' low level of trait anxiety rather than their high defensiveness. CONCLUSIONS: Individuals high in trait anxiety are especially sensitive to situations involving social evaluation but not those characterized by danger to their health or physical well-being.

Electrocatalytic CO2 reduction with a membrane supported manganese catalyst in aqueous solution.

[Mn(bpy)(CO)3Br] cast in a Nafion membrane is an active heterogeneous electrocatalyst with good selectivity for CO2 reduction to CO in neutral aqueous electrolyte. Addition of multi-walled carbon nanotubes (MWCNT) leads to a ∼10 fold current enhancement and stable CO : H2 yields (1 : 2) at -1.4 V vs. Ag/AgCl at pH 7.

Self assembled composites of luminescent Ru(II) metallopolymers and the Dawson polyoxometalate α-[Mo18O54(SO4)2]4-.

The interaction of two luminescent metallopolymers; [Ru(bpy)(2)(PVP)(10)](2+) and [Ru(bpy)(2)(CAIP)co-poly(7)](+), where bpy is 2,2'-bipyridyl, PVP is polyvinylpyridine, and (CAIP)co-poly(7) is poly(styrene(6)-co-p-(aminomethyl)styrene) amide linked to 2-(4-carboxyphenyl)imidazo[4,5-f] [1,10]phenanthroline, with the Dawson polyoxomolybdate α-[Mo(18)O(54)(SO(4))(2)](4-) is described. Both metallopolymers undergo electrostatic association with the polyoxometalate. From both electronic and luminescence spectroscopy the thermodynamic products were determined to be {[Ru(bpy)(2)(PVP)(10)](4.5)[Mo(18)O(54)(SO(4))(2)]}(5+) and {[Ru(bpy)(2)(CAIP)co-poly(7)](5)[Mo(18)O(54)(SO(4))(2)]}(+), i.e. in both instances, the number of ruthenium centres in the cluster exceeds the number required for charge neutralization of the molybdate centre. Association quenches the luminescence of the metallopolymer although, consistent with the excess of Ru(ii) present in the associated composites, emission is not completely extinguished even when a large excess of [Mo(18)O(54)(SO(4))(2)](4-) is present. The observed emission lifetime was not affected by [Mo(18)O(54)(SO(4))(2)](4-) therefore quenching was deemed static. The luminescent intensity data was found to fit best to a (sphere of action) Perrin model from which the radii of the quenching were calculated as 4.6 Å and 5.8 Å for [Ru(bpy)(2)(PVP)(10)](2+) and [Ru(bpy)(2)(CAIP co-poly)(7)](+) respectively. Both UV/Vis and resonance Raman data indicate the presence of a new optical transition centered around 490 nm for the composite, {[Ru(bpy)(2)(PVP)(10)](4.5)[Mo(18)O(54)(SO(4))(2)]}(5+) but not for {[Ru(bpy)(2)(CAIP)co-poly(7)](5)[Mo(18)O(54)(SO(4))(2)]}(+). This indicates strong electronic interaction between the metal centres in the former composite, which despite good thermodynamic analogy, is not observed for {[Ru(bpy)(2)(CAIP)co-poly(7)](5)[Mo(18)O(54)(SO(4))(2)]}(+). These results are consistent with photoelectrochemical studies of layer by layer assemblies of these films which indicate that the ruthenium centre sensitizes polyoxometalate photo-oxidation of benzyl alcohol in {[Ru(bpy)(2)(PVP)(10)](4.5)[Mo(18)O(54)(SO(4))(2)]}(5+) but not in {[Ru(bpy)(2)(CAIP)co-poly(7)](5)[Mo(18)O(54)(SO(4))(2)]}(+).

Enhanced photocurrent production from thin films of Ru(II) metallopolymer/Dawson polyoxotungstate adducts under visible irradiation.

Thin films of polyoxometalates that are sensitized with a Ru(II) metallopolymer generate significant photocurrents in the presence of benzyl alcohol and visible light. Significantly, the photocurrent generated by the tungstate based adduct, α-[P(2)W(18)O(62)](6-), is approximately seven fold larger than that found for the Dawson polyoxomolybdate α-[S(2)Mo(18)O(62)](4-).

Electronic and photophysical properties of adducts of [Ru(bpy)3]2+ and Dawson-type sulfite polyoxomolybdates α/ß-[Mo18O54(SO3)2]4-.

The spectroscopic and photophysical properties of [Ru(bpy)(3)](2)[[Mo(18)O(54)(SO(3))(2)], where bpy is 2,2'-bipyridyl and [Mo(18)O(54)(SO(3))(2)](4-) is either the α or ß-sulfite containing polyoxomolybdate isomer, have been measured and compared with those for the well known but structurally distinct sulfate analogue, α-[Mo(18)O(54)(SO(4))(2)](4-). Electronic difference spectroscopy revealed the presence of new spectral features around 480 nm, although they are weak in comparison with the [Ru(bpy)(3)](2)[Mo(18)O(54)(SO(4))(2)] analogue. Surprisingly, Stern-Volmer plots of [Ru(bpy)(3)](2+) luminescence quenching by the polyoxometallate revealed the presence of both static and dynamic quenching for both α and ß-[Mo(18)O(54)(SO(3))(2)](4-). The association constant inferred for the ion cluster [Ru(bpy)(3)](2)α-[Mo(18)O(54)(SO(4))(2)] is K = 5.9 ± 0.56 × 10(6) and that for [Ru(bpy)(3)](2)ß-[Mo(18)O(54)(SO(4))(2)] is K = 1.0 ± 0.09 × 10(7). Unlike the sulfate polyoxometalates, both sulfite polyoxometalate-ruthenium adducts are non-luminescent. Despite the strong electrostatic association in the adducts resonance Raman and photoelectrochemical studies suggests that unlike the sulfato polyoxometalate analogue there is no sensitization of the polyoxometalate photochemistry by the ruthenium centre for the sulfite anions. In addition, the adducts exhibit photochemical lability in acetonitrile, attributable to decomposition of the ruthenium complex, which has not been observed for other [Ru(bpy)(3)](2+) -polyoxometalate adducts. These observations suggest that less electronic communication exists between the [Ru(bpy)(3)](2+) and the sulfite polyoxoanions relative to their sulfate polyoxoanion counterparts, despite their structural and electronic analogy. The main distinction between sulfate and sulfite polyoxometalates lies in their reversible reduction potentials, which are more positive by approximately 100 mV for the sulfite anions. This suggests that the capacity for [Ru(bpy)(3)](2+) or analogues to sensitize photoreduction in the adducts of polyoxometalates requires very sensitive redox tuning.