Maximizing Photon-to-Electron Conversion for Atom Efficient Photoredox Catalysis.

Photoredox catalysis is a powerful tool to access challenging and diverse syntheses. Absorption of visible light forms the excited state catalyst (*PC) but photons may be wasted if one of several unproductive pathways occur. Facile dissociation of the charge-separated encounter complex [PC:D], also known as (solvent) cage escape, is required for productive chemistry and directly governs availability of the critical PC intermediate.

Relative biological effectiveness of clinically relevant photon energies for the survival of human colorectal, cervical, and prostate cancer cell lines.

Relative biological effectiveness (RBE) differs between radiation qualities. However, an RBE of 1.0 has been established for photons regardless of the wide range of photon energies used clinically, the lack of reproducibility in radiobiological studies, and outdated reference energies used in the experimental literature.

Electrochemiluminescence Enhanced by a Non-Emissive Dual Redox Mediator.

A sulfonated tris(1-phenylpyrazolato)iridium(III) complex ([Ir(sppz)]) serves as a proof-of-concept non-emissive enhancer of the widely used ECL detection system of tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)]) with tri-n-propylamine (TPrA) co-reactant, acting through electrocatalysis of TPrA oxidation and efficient chemi-excitation of the luminophore. Using self-interference ECL spectroscopy, we show that the enhancer extends diffusion of the required electrogenerated precursors from the electrode surface. Previously reported enhancement through these pathways has been confounded by the inherent ECL of the enhancer, but the increase in [Ru(bpy)] ECL intensity using [Ir(sppz)] was obtained without its concomitant emission.

A Novel Cytotoxic Mechanism for Triple-Negative Breast Cancer Cells Induced by the Type II Heat-Labile Enterotoxin LT-IIc through Ganglioside Ligation.

Triple-negative breast cancer (TNBC), which constitutes 10-20 percent of all breast cancers, is aggressive, has high metastatic potential, and carries a poor prognosis due to limited treatment options. LT-IIc, a member of the type II subfamily of ADP-ribosylating-heat-labile enterotoxins that bind to a distinctive set of cell-surface ganglioside receptors-is cytotoxic toward TNBC cell lines, but has no cytotoxic activity for non-transformed breast epithelial cells. Here, primary TNBC cells, isolated from resected human tumors, showed an enhanced cytotoxic response specifically toward LT-IIc, in contrast to other enterotoxins that were tested.

Comprehensive care programmes for children with medical complexity.

Background: Children with medical complexity (CMC) represent a small, but growing, proportion of all children. Regardless of their underlying diagnosis, by definition, all CMC have similar functional limitations and high healthcare needs. It has been suggested that improving aspects of healthcare delivery for CMC improves health- and quality of life-related outcomes for children and their families and reduces healthcare-related expenditure.

Chemiluminescence and electrochemiluminescence of water-soluble iridium(III) complexes containing a tetraethylene-glycol functionalised triazolylpyridine ligand.

Background: Iridium(III) complexes, exhibiting high luminescence quantum yields and a wide range of emission colours, are promising alternatives to tris(2,2'-bipyridine)ruthenium(II) for chemiluminescence (CL) and electrochemiluminescence (ECL) detection. This emerging class of reagent, however, is limited by the poor solubility of many iridium(III) complexes in aqueous solution, and lack of understanding of their remarkably variable selectivities towards different analytes.

Results: Seven [Ir(C^N)(pt-TEG)] complexes, exhibiting a wide range of reduction potentials and emission energies, were examined with six model analytes.

Electrochemiluminescence of a First-Row d Transition Metal Complex.

We report the electrochemiluminescence (ECL) of a 3d Cr(0) complex ([Cr(L)]; λ=735 nm) with comparable photophysical properties to those of ECL-active complexes of 4d or 5d precious metal ions. The electrochemical potentials of [Cr(L)] are more negative than those of [Ir(ppy)] and render the [Cr(L)]* excited state inaccessible through conventional co-reactant ECL with tri-n-propylamine or oxalate. ECL can be obtained, however, through the annihilation route in which potentials sufficient to oxidise and reduce the luminophore are alternately applied.

Photochemical Povarov-type Reactions: Electron Donor-Acceptor Photoactivation by Visible Light.

This report investigates the mechanism of photochemical Povarov-type reactions of ,-dialkylanilines and maleimides in polar solvents (DMF or dioxane) in the presence of light. Fundamental aspects of the electron donor-acceptor (EDA) photoactivation pathway proposed to underpin this chemistry are examined through integrated experimental and computational studies. This approach provided evidence supporting the involvement of an EDA complex in facilitating this chemistry via a reaction mechanism that does not involve a triplet manifold.

Antimicrobial and Adjuvant Potencies of Di--alkyl Substituted Diazalariat Ethers.

Lariat ethers are macrocyclic polyethers-crown ethers-to which sidearms are appended. 4,13-Diaza-18-crown-6 having twin alkyl chains at the nitrogens show biological activity. They exhibit antibiotic activity, but when co-administered at with an FDA-approved antibiotic, the latter's potency is often strongly enhanced.

Inborn Errors of Immunity in Children With Invasive Pneumococcal Disease: A Multicenter Prospective Study.

Background: In settings with universal conjugate pneumococcal vaccination, invasive pneumococcal disease (IPD) can be a marker of an underlying inborn error of immunity. The aim of this study was to determine the prevalence and characterize the types of immunodeficiencies in children presenting with IPD.

Methods: Multicenter prospective audit following the introduction of routinely recommended immunological screening in children presenting with IPD.

Photoinitiated Energy Transfer in Porous-Cage-Stabilised Silver Nanoparticles.

We report a new composite material consisting of silver nanoparticles decorated with three-dimensional molecular organic cages based on light-absorbing porphyrins. The porphyrin cages serve to both stabilize the particles and allow diffusion and trapping of small molecules close to the metallic surface. Combining these two photoactive components results in a Fano-resonant interaction between the porphyrin Soret band and the nanoparticle-localised surface-plasmon resonance.

Comparison of mechanical properties and host tissue response to OviTex™ and Strattice™ surgical meshes.

Purpose: This study compared the in vitro/benchtop and in vivo mechanical properties and host biologic response to ovine rumen-derived/polymer mesh hybrid OviTex™ with porcine-derived acellular dermal matrix Strattice™ Firm.

Methods: OviTex 2S Resorbable (OviTex 2S-R) and Strattice morphology were examined in vitro using histology and scanning electron microscopy; mechanical properties were assessed via tensile test; in vivo host biologic response and explant mechanics were evaluated in a rodent subcutaneous model. Separately, OviTex 1S Permanent (OviTex 1S-P) and Strattice were evaluated in a primate abdominal wall repair model.

Health of children who experienced Australian immigration detention.

Background: Australian immigration policy resulted in large numbers of children being held in locked detention. We examined the physical and mental health of children and families who experienced immigration detention.

Methods: Retrospective audit of medical records of children exposed to immigration detention attending the Royal Children's Hospital Immigrant Health Service, Melbourne, Australia, from January 2012 -December 2021.

Optimal Geometry for Plasmonic Hot-Carrier Extraction in Metal-Semiconductor Nanocrystals.

Plasmon-induced energy and charge transfer from metal nanostructures hold great potential for harvesting solar energy. Presently, the efficiencies of charge-carrier extraction are still low due to the competitive ultrafast mechanisms of plasmon relaxation. Using single-particle electron energy loss spectroscopy, we correlate the geometrical and compositional details of individual nanostructures to their carrier extraction efficiencies.

Extending Photocatalyst Activity through Choice of Electron Donor.

Sacrificial additives are commonly employed in photoredox catalysis as a convenient source of electrons, but what occurs after electron transfer is often overlooked. Tertiary alkylamines initially form radical cations following electron transfer, which readily deprotonate to form strongly reducing, neutral α-amino radicals. Similarly, the oxalate radical anion (CO) rapidly decomposes to form CO ( ≈ -2.

Prospective Study of Clinical Outcomes From a Breast Implant Assessment Service.

Background: Breast augmentation remains the commonest cosmetic surgical procedure worldwide, in spite of recent regulatory action.

Objectives: The aim of this study was to evaluate women with breast implants attending a breast implant assessment clinic and to capture clinical and implant data in women presenting to the service.

Methods: Patients were enrolled prospectively between January 2018 and December 2021.

The forgotten reagent of photoredox catalysis.

Visible light powers an ever-expanding suite of reactions to both make and break chemical bonds under otherwise mild conditions. As a reagent in photochemical synthesis, light is obviously critical for reactivity but rarely optimized other than in light/dark controls. This Frontier Article presents an overview of recent research that investigates the unique ways light may be manipulated, and its unusual interactions with homogeneous transition metal and organic photocatalysts.

Reinterpreting the Fate of Iridium(III) Photocatalysts─Screening a Combinatorial Library to Explore Light-Driven Side-Reactions.

Photoredox catalysts are primarily selected based on ground and excited state properties, but their activity is also intrinsically tied to the nature of their reduced (or oxidized) intermediates. Catalyst reactivity often necessitates an inherent instability, thus these intermediates represent a mechanistic turning point that affords either product formation or side-reactions. In this work, we explore the scope of a previously demonstrated side-reaction that partially saturates one pyridine ring of the ancillary ligand in heteroleptic iridium(III) complexes.

Promoting Burnout Prevention Through a Socio-Ecological Lens.

There has been increased attention on the role of indirect trauma and the need for burnout prevention for behavioral health workers. Though frontline workers traditionally serve high needs and vulnerable populations, pandemic challenges have involved service delivery pivots to meet social distancing and safety guidelines, and have resulted in staff shortages and increased caseloads, increased use of maladaptive coping skills such as substance use, and increased mental health concerns within the workforce. Secondary traumatic stress and vicarious trauma within the workforce have often been linked with increased feelings of burnout.

Not just a chalazion-focal eyelid and orbital infection with Saksaenea vasiformis in an immunocompetent child.

We present the case of a 2-year-old immunocompetent boy who presented with subacute right-sided orbital cellulitis due to Saksaenea vasiformis infection. Initial differential diagnoses included chalazion and localized soft tissue malignancy. There was no history of trauma.

Understanding Ir(III) Photocatalyst Structure-Activity Relationships: A Highly Parallelized Study of Light-Driven Metal Reduction Processes.

High-throughput synthesis and screening methods were used to measure the photochemical activity of 1440 distinct heteroleptic [Ir(C^N)(N^N)] complexes for the photoreduction of Sn(II) and Zn(II) cations to their corresponding neutral metals. Kinetic data collection was carried out using home-built photoreactors and measured initial rates, obtained through an automated fitting algorithm, spanned between 0-120 μM/s for Sn(0) deposition and 0-90 μM/s for Zn(0) deposition. Photochemical reactivity was compared to photophysical properties previously measured such as deaerated excited state lifetime and emission spectral data for these same complexes; however, no clear correlations among these features were observed.

Characterization of the ganglioside recognition profile of Escherichia coli heat-labile enterotoxin LT-IIc.

The heat-labile enterotoxins of Escherichia coli and cholera toxin of Vibrio cholerae are related in structure and function. Each of these oligomeric toxins is comprised of one A polypeptide and five B polypeptides. The B-subunits bind to gangliosides, which are followed by uptake into the intoxicated cell and activation of the host's adenylate cyclase by the A-subunits.

Immunomodulatory regulation by heat-labile enterotoxins and potential therapeutic applications.

: Heat-labile enterotoxins (HLTs) and their cognate ganglioside receptors have been extensively studied because of their therapeutic potential. Gangliosides play arole in modulating effector cells of the immune system, and HLTs provide a novel means for stimulating ganglioside-mediated responses in immunocompetent cells.: To evaluate the mechanisms of HLT adjuvanticity, a systemic literature review was performed using relevant keyword searches of the PubMed database, accessing literature published as recently as late 2020.