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SUMMARY: Algae such as diatoms and haptophytes have distinct photosynthetic pigments from plants, including a novel set of carotenoids. This includes a primary xanthophyll cycle comprised of diadinoxanthin and its de‐epoxidation product diatoxanthin that enables the switch between light harvesting and non‐photochemical quenching (NPQ)‐mediated dissipation of light energy. The enzyme responsible for the reversal of this cycle was previously unknown. Here, we identified zeaxanthin epoxidase 3 (ZEP3) from Phaeodactylum tricornutum as the candidate diatoxanthin epoxidase. Knocking out the ZEP3 gene caused a loss of rapidly reversible NPQ following saturating light exposure. This correlated with the maintenance of high concentrations of diatoxanthin during recovery in low light. Xanthophyll cycling and NPQ relaxation were restored via complementation of the wild‐type ZEP3 gene. The zep3 knockout strains showed reduced photosynthetic rates at higher light fluxes and reduced specific growth rate in variable light regimes, likely due to the mutant strains becoming locked in a light energy dissipation state. We were able to toggle the level of NPQ capacity in a time and dose dependent manner by placing the ZEP3 gene under the control of a β‐estradiol inducible promoter. Identification of this gene provides a deeper understanding of the diversification of photosynthetic control in algae compared to plants and suggests a potential target to improve the productivity of industrial‐scale cultures. Significance Statement: This work reveals the identify of the enzyme responsible for the deactivation of the xanthophyll cycle and photoprotection in diatoms. [ABSTRACT FROM AUTHOR]

Artificial light harvesters require ordered arrangement of chromophores. We covalently attach three organic chromophore ligands to silicon dioxide nanoparticles. This allows us to study inter-ligand energy transfer when attached to SiO2 nanoparticles, creating a simple system with a large ratio of donors to acceptors. Using steady-state and transient spectroscopy measurements we quantify this energy transfer between ligands. We show a maximum transfer efficiency of 30% and measure the 2D diffusion length of anthracene carboxylic acid on SiO2 to be between 0.6 and 2.2 nm. [ABSTRACT FROM AUTHOR]

Objective: To determine the relationships between: (i) total ED length of stay (EDLOS) and in‐hospital mortality, ward clinical deterioration; and (ii) between time of bed request, ward transfer and in‐hospital mortality, with a particular focus on patients transferred just prior to a 4 h EDLOS. Methods: Retrospective cohort study using data from three acute care hospitals in Melbourne, Australia. Adult patients admitted from the ED to a non‐monitored ward within 8 h. Patients were sub‐grouped by EDLOS; EDLOS 3.5–4 h compared to 0–3.5 h and 4–8 h. In‐hospital mortality, number of medical emergency team (MET)/cardiac arrest team (CAT) events. Results: A total of 24 746 patients were included: 4396 patients with EDLOS <210 min; 4090 patients with EDLOS of 210–240 min; and 16 260 patients with EDLOS >240 min. Mortality overall was 2.2% (n = 545), highest mortality was seen with EDLOS >4 h (2.4%, n = 399) and lowest in patients with EDLOS 3.5–4 h (1.5%, n = 63, OR 0.67 [95% CI: 0.47–0.93, P = 0.02]). Time from bed request to transfer of >240 min was associated with increased odds of death at hospital discharge (adjusted OR 1.39 [95% CI: 1.08–1.78]). There was no difference in rate of MET calls within 24 h between groups (3.5–4 h = 64 [1.5%], <3.5 h = 60 [1.5%], 4–8 h = 235 [1.4%]). Conclusions: Both shorter time in ED and shorter time between bed request and ward transfer were independently associated with improved outcomes. Whole of hospital measures to reduce length of stay in the ED should focus on shorter ward transfer times after bed request. [ABSTRACT FROM AUTHOR]

The ability to control the solid-statestructure of organic electronicmaterials can have a large effect on the quality of the devices towhich they are applied. In this paper, we describe the use of π–πinteractions to direct the crystal structure/solid-state arrangementof boron subphthalocyanine (BsubPc) derivatives by taking advantageof the π-electron-deficiency (π-acidity) of the BsubPcmolecular fragment. First, we outline why BsubPc is a π-acidby looking at its chemical characteristics and the structure of crystalsformed with other π-acidic moieties. Then we show how the solid-statearrangement of BsubPc can be purposefully altered by adding π-basicsubstituents. We found that adding a naphthoxy substituent providesan interaction that is strong enough to direct BsubPc into a novelsolid-state arrangement made up of ribbons (or catemers) of moleculeslinked through π-stacking interactions between the naphthoxyand neighboring BsubPc molecular fragments. A similar effect was alsoseen when the naphthoxy fragment was added to the stronger π-acidperfluoro-BsubPc (F12BsubPc). [ABSTRACT FROM AUTHOR]

The crystal structures of three sulfonate pseudohalide derivatives of boron subphthalocyanine (BsubPc) are described and compared with four structures of three published sulfonate derivatives. Benzenesulfonate boron subphthalocyanine [(benzenesulfonato)(subphthalocyaninato)boron, C30H17BN6O3S, (I)] crystallizes in the space group P with Z = 2. The structure contains two centrosymmetric π-stacking interactions between the concave faces of the isoindoline units in the BsubPc ligands. 3-Nitrobenzenesulfonate boron subphthalocyanine [(3-nitrobenzenesulfonato)(subphthalocyaninato)boron, C30H16BN7O5S, (II)] crystallizes in the space group P21/ c with Z = 4. The structure contains an intermolecular S-O...π interaction from the sulfonate group to a five-membered N-containing ring of an isoindoline unit on the concave side of a neighbouring BsubPc ligand, at a distance of 3.151 (3) Å. The crystal of methanesulfonate boron subphthalocyanine [(methanesulfonato)(subphthalocyaninato)boron, C25H15BN6O3S, (III)] was produced via sublimation and it is not a solvate, in contrast with two previously published structures of the same compound. Compound (III) crystallizes in the space group P21/ n with Z = 2, and its structure is similar to that of the more common compound Cl-BsubPc. [ABSTRACT FROM AUTHOR]

Boronsubphthalocyanine (BsubPc) derivativesare materialsthat have recently seen an increase in attention, particularily forapplication as colorants and functional materials in organic electronicdevices. However, the solubilities of most BsubPcderivativesare too low to utilize solution-based processing techniques. Wherethere are derivatives that are soluble, they rely on the additionof large alkyl chains for solubilization the result of which is anincrease in the molecular weight and a decrease of the specific absorptivityof the BsubPc. In this paper we disclose the identityof two mass-efficient, highly soluble BsubPcderivatives:3-methylphenoxy-BsubPcand 3,4-dimethylphenoxy-BsubPc. We compare their solubilities and crystal packingstructures to previously known BsubPcderivatives. Weput forward a symmetry-based argument for the reason for their surprisinglyhigh solubility wherein we treat the molecules as two separate fragments:the phenoxy group and the BsubPcgroup. The symmetry-basedargument suggests that by ignoring the BsubPcfragmentcommon to each derivative a better estimate of the relative solubilitiescan be estimated through previously established empirical formulas. [ABSTRACT FROM AUTHOR]

The synthesis and study of a series of pseudohalides of boron subphthalocyanine (BsubPc) are reported. Each pseudohalide has been compared to the more common chloride and bromide of BsubPc, and we have found that most react slower under standard phenoxylation and hydrolysis conditions. Three pseudohalides (TsO-BsubPc, MsO-BsubPc, and BsO-BsubPc) do not hydrolyze at all even after prolonged periods of time in the presence of water. Single crystals of TsO-, MsO-, and ClsO-BsubPc were obtained, and their structures were unambiguously determined. [ABSTRACT FROM AUTHOR]

We report the synthesis and characterization of a series of para-halo-phenoxy-boronsubphthalocyanines (BsubPcs). Across this series, a crystal polymorph of p-bromophenoxy-BsubPc (α-BrPhO-BsubPc) contains a clear and discernible π–Br interaction directing crystallization into a motif not previously seen for phenoxy-BsubPcs. [ABSTRACT FROM AUTHOR]

We report the synthesis and systematic description of a series of five para-substituted phenoxy-BsubPcsincluding their characterization in the crystal state. The nature of the substituents on the phenoxy molecular fragment was chosen so as to vary both the size and electronegativity: specifically with increasingly bulky para-alkyl groups from hydrogen to tert-octyl and a single electronegative substitute (F). Examination of the arrangement of the phenoxy-BsubPcswithin single crystals allows us to place each into one of the two categories. The first, which contains all but one of the derivatives, has a repeating motif which is made up of dimers of the BsubPcmolecular fragments. The second, containing only the derivative possessing the large tert-octyl substituent, is characterized by the formation of ribbons instead of dimers of the BsubPcfragment. Regardless of motif the arrangement of the BsubPcmolecular fragments was found to be convace–concave. [ABSTRACT FROM AUTHOR]

We studied the optical properties of hybrid multilayer microspheres (HMMs). We prepared multilayer particles with alternating radial layers of gold nanoparticles (NPs) and poly(methyl methacrylate) and achieved control over particle size, the thickness of particle layers, and the surface coverage of gold NPs. We showed the ability to tune the spectral characteristics of the HMMs, which was based on frequency dispersion of the dielectric constant of polymer–metal NP structures. Good agreement between experimental and theoretical extinction properties of the HMMs was obtained. In comparison with multilayer structures synthesized solely from polymers, hybrid multilayer microspheres have a larger refractive layer contrast between adjacent layers, which is important for practical applications in optoelectronic devices. [ABSTRACT FROM AUTHOR]

This letter reports optical properties of spherical dielectric particles with alternating layers of high and low refractive indices. The authors “predesigned” and synthesized polymer microspheres with alternating polystyrene and poly(trifluoroethyl methacrylate) layers of various thicknesses. Extinction of the microspheres was examined in a broad spectral range. A multipole expansion of electromagnetic field was applied for calculating the extinction efficiency of the particles. Excellent agreement was obtained between experimental and theoretical extinction curves. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to describe the burden of patients presenting to the ED with symptoms occurring after receiving a COVID‐19 vaccination. Methods: This was a retrospective cohort study performed over a 4‐month period across two EDs. Participants were eligible for inclusion if it was documented in the ED triage record that their ED attendance was associated with the receipt of a COVID‐19 vaccination. Data regarding the type of vaccine (Comirnaty or ChAdOx1) were subsequently extracted from their electronic medical record. Primary outcome was ED length of stay (LOS) and secondary outcomes included requests for imaging and ED disposition destination. Results: During the study period of 22 February 2021 to 21 June 2021, 632 patients were identified for inclusion in the present study, of which 543 (85.9%) had received the ChAdOx1 vaccination. The highest proportion of COVID‐19 vaccine‐related attendances occurred in June 2021 and accounted for 21 (8%) of 262 total daily ED attendances. Patients who had an ED presentation related to ChAdOx1 had a longer median ED LOS (253 vs 180 min, P < 0.001) compared to Comirnaty and a higher proportion had haematology tests and imaging requested in the ED. Most patients (n = 588, 88.8%) were discharged home from the ED. Conclusion: There was a notable proportion of ED attendances related to recent COVID‐19 vaccination administration, many of which were associated with lengthy ED stays and had multiple investigations. In the majority of cases, the patients were able to be discharged home from the ED. [ABSTRACT FROM AUTHOR]

Withthe knowledge that the dominant photodynamic therapy (PDT)mechanism of 1a(WST09) switched from type 2 to type1 for 1b(WST11) upon taurine-driven E-ring opening,we hypothesized that taurine-driven E-ring opening of bacteriochlorophyllderivatives and net-charge variations would modulate reactive oxygenspecies (ROS) photogeneration. Eight bacteriochlorophyll aderivatives were synthesized with varying charges that either containedthe E ring (2a–5a) or were synthesizedby taurine-driven E-ring opening (2b–5b). Time-dependent density functional theory (TDDFT) modeling showedthat all derivatives would be type 2 PDT-active, and ROS-activatedfluorescent probes were used to investigate the photogeneration ofa combination of type 1 and type 2 PDT ROS in organic- and aqueous-basedsolutions. These investigations validated our predictive modelingcalculations and showed that taurine-driven E-ring opening and increasingnegative charge generally enhanced ROS photogeneration in aqueoussolutions. We propose that these structure–activity relationshipsmay provide simple strategies for designing bacteriochlorins thatefficiently generate ROS upon photoirradiation. [ABSTRACT FROM AUTHOR]

The physical properties, including the solid state arrangement,photophysics, solubility, and electrochemical behavior of a seriesof halo-BsubPcs (halo = F, Cl, Br) have been measured (IUPAC namehalo-(7,12:14,19-diimino-21,5-nitrilo-5H-tribenzo(c,h,m)(1,6,11)triazacyclopentadecinato)-boron(III)).We have found that across the series all are relatively similar inmost regards. Exceptions include that F-BsubPc can be 5 to 25 timesmore soluble than Cl-BsubPc in common organic solvents. F-BsubPc wasalso found to be hydrolytically stable under the conditions tested,whereas Cl-BsubPc and Br-BsubPc readily hydrolyzed to form HO-BsubPc.The relative rates of reaction for the series of halo-BsubPcs understandard phenoxylation conditions have also been measured. It wasfound that F-BsubPc does not undergo phenoxylation, whereas Br-BsubPcshowed a markedly higher reaction rate relative to Cl-BsubPc. Basedon these data some assumptions can be made as to the suitability ofeither F-BsubPc or Br-BsubPc to be used in place of the more commonCl-BsubPc. The data indicate that F-BsubPc is a potential replacementfor Cl-BsubPc in organic electronic materials whereas Br-BsubPc mightbe more suitable as a chemical intermediate. Comments on the syntheticmethods used to produce each halo-BsubPc are also made. [ABSTRACT FROM AUTHOR]

Objective: To assess the feasibility of an ED presenting complaint (PC) tool that categorised all ED PCs into 10 categories. Methods: A retrospective analysis of 1445 consecutive patient encounters was conducted. The primary outcome was the frequency of use of the 10 PC categories. Results: Of the 1203 patient encounters meeting inclusion criteria, the PC tool was completed by clinicians in 574 (47.7%). When completed, the tool's 10 options were selected for most presentations (72.3%). Conclusion: The PC tool captured the majority of presenting complaints in 10 categories. External validation is recommended. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to describe the epidemiology and clinical features of patients presenting to the ED with suspected and confirmed COVID‐19. Methods: The COVID‐19 ED (COVED) Project is an ongoing prospective cohort study in Australian EDs. This analysis presents data from eight sites across Victoria and Tasmania for July 2020 (during Australia's 'second wave'). All adult patients who met criteria for 'suspected COVID‐19' and underwent testing for SARS‐CoV‐2 in the ED were eligible for inclusion. Study outcomes included a positive SARS‐CoV‐2 test result and mechanical ventilation. Results: In the period 1 July to 31 July 2020, there were 30 378 presentations to the participating EDs and 2917 (9.6%; 95% confidence interval 9.3–9.9) underwent testing for SARS‐CoV‐2. Of these, 50 (2%) patients returned a positive result. Among positive cases, two (4%) received mechanical ventilation during their hospital admission compared to 45 (2%) of the SARS‐CoV‐2 negative patients (odds ratio 1.7, 95% confidence interval 0.4–7.3; P = 0.47). Two (4%) SARS‐CoV‐2 positive patients died in hospital compared to 46 (2%) of the SARS‐CoV‐2 negative patients (odds ratio 1.7, 95% confidence interval 0.4–7.1; P = 0.49). Strong clinical predictors of a positive SARS‐CoV‐2 result included self‐reported fever, non‐smoking status, bilateral infiltrates on chest X‐ray and absence of a leucocytosis on first ED blood tests (P < 0.05). Conclusion: In this prospective multi‐site study from July 2020, a substantial proportion of ED patients required SARS‐CoV‐2 testing, isolation and enhanced infection prevention and control precautions. Presence of SARS‐CoV‐2 on nasopharyngeal swab was not associated with death or mechanical ventilation. [ABSTRACT FROM AUTHOR]

Objective: The number of patients with suspected COVID‐19 presenting to Australian EDs continues to impose a burden on healthcare services. Isolation is an important aspect of infection prevention and control, but has been associated with undesirable consequences among hospital inpatients. The aim of the present study was to determine if isolation is associated with an increased length of stay (LOS) in the ED. Methods: The Registry for Emergency Care Project is a prospective cohort study with a series of nested sub‐studies. The present study was a retrospective analysis of adult patients allocated an Australasian Triage Scale category of 1 or 2 who presented to a tertiary ED between 18 and 31 May 2020. The primary outcome was ED LOS. Regression methods were used to determine the independent association between ED isolation and LOS. Results: There were 447 patients who met inclusion criteria, of which 123 (28%) were managed in isolation. The median (interquartile range) ED LOS was 259 (210–377) min for the isolation group and 204 (126–297) min for the non‐isolation group, a difference in median ED LOS of 55 min (P < 0.001). Isolation was independently associated with a 23% increase in ED LOS (P = 0.002) and doubled the odds of an ED stay of more than 4 h (adjusted odds ratio 2.2 [1.4–3.4], P = 0.001). Conclusion: Consistent with the anecdotal experience of Australian ED clinicians, the present study demonstrated an increased ED LOS for patients managed in isolation. Enhanced infection prevention and control precautions will be required during and beyond the current pandemic, creating significant ongoing challenges for emergency care systems. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to describe the epidemiological and clinical features of ED patients with suspected and confirmed COVID‐19. Methods: The COVID‐19 Emergency Department (COVED) Project is an ongoing prospective cohort study that includes all adult patients presenting to The Alfred Hospital ED who undergo testing for SARS‐CoV‐2. Current guidelines recommend testing for patients with fevers or chills, acute respiratory symptoms or a high‐risk exposure history, as well as implementation of infection prevention and control precautions for all suspected and confirmed cases. Study outcomes include a positive SARS‐CoV‐2 test result and intensive respiratory support. Results: In the period 1–30 April 2020, 702 of 3453 ED patients (20%; 95% CI 19–22) were tested, with a significant increase during the study period (incident rate ratio 1.019; 95% confidence interval 1.017–1.021, P < 0.001). The primary outcome of a positive SARS‐CoV‐2 test was recorded in 14 patients (2%; 95% confidence interval 1–3). Shortness of breath (77%), fatigue (100%), myalgia (67%) and diarrhoea (67%) were common among positive cases, while close contact (9%), fever (0%) and healthcare occupation (0%) were not. No positive cases required intensive respiratory support in the ED. Conclusions: The volume of ED patients with suspected COVID‐19 is increasing. Low numbers of positive cases precluded development of accurate predictive tools, but the COVED Project is fulfilling an important role in monitoring the burden of infection prevention and control requirements on the ED. The increasing number of patients meeting isolation criteria has the potential to impact on patient flow and may lead to ED overcrowding. [ABSTRACT FROM AUTHOR]

Objective: In Australia, the current ED burden related to COVID‐19 is from 'suspected' rather than 'confirmed' cases. The initial aim of the Registry for Emergency Care (REC) Project is to determine the impact of isolation processes on the emergency care of all patients. Methods: The REC Project builds on the COVID‐19 Emergency Department Quality Improvement (COVED) Project. Outcomes measured include times to critical assessment and management. Results: Clinical tools will be generated to inform emergency care, both during and beyond the COVID‐19 pandemic. Conclusions: The REC Project will support ED clinicians in the emergency care of all patients. [ABSTRACT FROM AUTHOR]

Objective: The COVID‐19 Emergency Department (COVED) Quality Improvement Project aims to provide regular and real‐time clinical information to ED clinicians caring for patients with suspected and confirmed COVID‐19. The present study summarises data from the first 2 weeks of the study. Methods: COVED is an ongoing prospective cohort study that commenced on 1 April 2020. It includes all adult patients presenting to a participating ED who undergo testing for SARS‐CoV‐2. Data are collected prospectively and entered into a bespoke registry. Outcomes include a positive SARS‐CoV‐2 polymerase chain reaction test result and requirement for intensive respiratory support. Results: In the period 1–14 April 2020, 240 (16%) of 1508 patients presenting to The Alfred Emergency and Trauma Centre met inclusion criteria. Of these, 11 (5%) tested positive for SARS‐CoV‐2. The mean age of patients was 60 years and the commonest symptoms were acute shortness of breath (n = 122 [67%]), cough (n = 108 [56%]) or fever (n = 98 [51%]). Overseas travel or known contact with a confirmed case was reported by 24 (14%) and 16 (10%) patients, respectively. Fever or hypoxia was recorded in 23 (10%) and 11 (5%) patients, respectively. Eleven (5%) patients received mechanical ventilation in the ED, of whom none tested positive for SARS‐CoV‐2. Conclusions: Among patients presenting to a tertiary ED with suspected COVID‐19, only a small proportion tested positive for SARS‐CoV‐2. Although the low incidence of positive cases currently precludes the development of predictive tools, the COVED Project demonstrates that the rapid establishment of an agile clinical registry for emergency care is feasible. [ABSTRACT FROM AUTHOR]

Objectives: There is an urgency to support Australian ED clinicians with real‐time tools as the COVID‐19 pandemic evolves. The COVID‐19 Emergency Department (COVED) Quality Improvement Project has commenced and will provide flexible and responsive clinical tools to determine the predictors of key ED‐relevant clinical outcomes. Methods: The COVED Project includes all adult patients presenting to a participating ED and meeting contemporary testing criteria for COVID‐19. The dataset has been embedded in the electronic medical record and the COVED Registry has been developed. Results: Outcomes measured include being COVID‐19 positive and requiring intensive respiratory support. Regression methodology will be used to generate clinical prediction tools. Conclusion: This project will support EDs during this pandemic. [ABSTRACT FROM AUTHOR]

A process for the gram scale synthesis of the oxygen bridged dimer of boron subphthalocyanine, μ-oxo-(BsubPc)2, has been developed. During the development it was found that a wide range of reaction pathways under diverse conditions lead to μ-oxo-(BsubPc)2 formation. However, obtaining μ-oxo-(BsubPc)2 as the main reaction product in appreciable yields and its subsequent isolation were extremely challenging. The best balance of purity, yield and conversion was achieved with a time controlled reaction of an equimolar reaction of HO-BsubPc with Br-BsubPc in the presence of K3PO4. The purification involved sequentially Soxhlet extraction, Kauffman column chromatography and train sublimation. We have repeated the process and yields ranged from 27 to 30% of pure, doubly-sublimed μ-oxo-(BsubPc)2. This process also enabled the synthesis of unsymmetric μ-oxo-(BsubPc)2s by reaction of HO-BsubPc with Br-F12BsubPc, Cl-Cl6BsubPc and Cl-Cl12BsubPc. After synthesis the solution-state properties of the unsymmetric μ-oxo-(BsubPc)2s were investigated, and compared to the symmetric μ-oxo-(BsubPc)2 and more broadly to other BsubPcs. The electronic properties of μ-oxo-(BsubPc)2 were found to differ from its unsymmetric counterparts, but were found to be similar to halo-BsubPcs. Furthermore, the photophysical properties of μ-oxo-(BsubPc)2, both symmetric and unsymmetric, differed greatly from all other known BsubPcs. [ABSTRACT FROM AUTHOR]

Boron subphthalocyanines have been explored as functionalmaterialsin a wide range of organic electronic applications including organiclight-emitting diodes and organic solar cells. They have only, however,been studied as small molecules; there have been no reports of boronsubphthalocyanine polymer(s) in the literature. Herein, the synthesisof the first boron subphthalocyanine-containing polymer, poly(4-methylstyrene)-co-poly(phenoxy boron subphthalocyanine), is reported alongwith its basic physical characterization/properties. The synthesisof the boron subphthalocyanine polymer was only possible via a postpolymerizationfunctionalization approach, where the boron subphthalocyanine moietyis appended to the side chain of a styrene-based prepolymer. The three-steptransformation begins with the nitroxide-mediated copolymerizationof 4-methylstyrene and 4-acetoxystyrene to form poly(4-methylstyrene)-co-poly(4-acetoxystyrene). The acetoxy groups are subsequentlydeacetylated to afford hydroxyl groups prior to phenoxylation withbromo boron subphthalocyanine to afford the title polymer(s). [ABSTRACT FROM AUTHOR]