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Near infrared energy remains untapped toward the maneuvering of entire solar spectrum harvesting for fulfilling the nuts and bolts of solar hydrogen production. We report the use of Au@Cu 7 S 4 yolk@shell nanocrystals as dual-plasmonic photocatalysts to achieve remarkable hydrogen production under visible and near infrared illumination. Ultrafast spectroscopic data reveal the prevalence of long-lived charge separation states for Au@Cu 7 S 4 under both visible and near infrared excitation. Combined with the advantageous features of yolk@shell nanostructures, Au@Cu 7 S 4 achieves a peak quantum yield of 9.4% at 500 nm and a record-breaking quantum yield of 7.3% at 2200 nm for hydrogen production in the absence of additional co-catalysts. The design of a sustainable visible- and near infrared-responsive photocatalytic system is expected to inspire further widespread applications in solar fuel generation. In this work, the feasibility of exploiting the localized surface plasmon resonance property of self-doped, nonstoichiometric semiconductor nanocrystals for the realization of wide-spectrum-driven photocatalysis is highlighted. Near infrared energy remains untapped toward the maneuvering of entire solar spectrum harvesting for fulfilling nuts and bolts of solar hydrogen production. Here, the authors report the use of Au@Cu 7 S 4 yolk@shell nanocrystals for hydrogen production from untapped near infrared energy.

The mitochondrion is well known for its key role in energy transduction. However, it is less well appreciated that it is also a focal point of iron metabolism. Iron is needed not only for heme and iron sulfur cluster (ISC)-containing proteins involved in electron transport and oxidative phosphorylation, but also for a wide variety of cytoplasmic and nuclear functions, including DNA synthesis. The mitochondrial pathways involved in the generation of both heme and ISCs have been characterized to some extent. However, little is known concerning the regulation of iron uptake by the mitochondrion and how this is coordinated with iron metabolism in the cytosol and other organelles (e.g., lysosomes). In this article, we discuss the burgeoning field of mitochondrial iron metabolism and trafficking that has recently been stimulated by the discovery of proteins involved in mitochondrial iron storage (mitochondrial ferritin) and transport (mitoferrin-1 and -2). In addition, recent work examining mitochondrial diseases (e.g., Friedreich's ataxia) has established that communication exists between iron metabolism in the mitochondrion and the cytosol. This finding has revealed the ability of the mitochondrion to modulate whole-cell iron-processing to satisfy its own requirements for the crucial processes of heme and ISC synthesis. Knowledge of mitochondrial iron-processing pathways and the interaction between organelles and the cytosol could revolutionize the investigation of iron metabolism.

There is no effective treatment for the cardiomyopathy of the most common autosomal recessive ataxia, Friedreich ataxia (FA). This disease is due to decreased expression of the mitochondrial protein, frataxin, which leads to alterations in mitochondrial iron (Fe) metabolism. The identification of potentially toxic mitochondrial Fe deposits in FA suggests Fe plays a role in its pathogenesis. Studies using the muscle creatine kinase (MCK) conditional frataxin knockout mouse that mirrors the disease have demonstrated frataxin deletion alters cardiac Fe metabolism. Indeed, there are pronounced changes in Fe trafficking away from the cytosol to the mitochondrion, leading to a cytosolic Fe deficiency. Considering Fe deficiency can induce apoptosis and cell death, we examined the effect of dietary Fe supplementation, which led to body Fe loading and limited the cardiac hypertrophy in MCK mutants. Furthermore, this study indicates a unique effect of heart and skeletal muscle-specific frataxin deletion on systemic Fe metabolism. Namely, frataxin deletion induces a signaling mechanism to increase systemic Fe levels and Fe loading in tissues where frataxin expression is intact (i.e., liver, kidney, and spleen). Examining the mutant heart, native size-exclusion chromatography, transmission electron microscopy, Mössbauer spectroscopy, and magnetic susceptibility measurements demonstrated that in the absence of frataxin, mitochondria contained biomineral Fe aggregates, which were distinctly different from isolated mammalian ferritin molecules. These mitochondrial aggregates of Fe, phosphorus, and sulfur, probably contribute to the oxidative stress and pathology observed in the absence of frataxin.

Room-temperature ultraviolet lasing in semiconductor nanowire arrays has been demonstrated. The self-organized, oriented zinc oxide nanowires grown on sapphire substrates were synthesized with a simple vapor transport and condensation process. These wide band-gap semiconductor nanowires form natural laser cavities with diameters varying from 20 to 150 nanometers and lengths up to 10 micrometers. Under optical excitation, surface-emitting lasing action was observed at 385 nanometers, with an emission linewidth less than 0.3 nanometer. The chemical flexibility and the one-dimensionality of the nanowires make them ideal miniaturized laser light sources. These short-wavelength nanolasers could have myriad applications, including optical computing, information storage, and microanalysis.

The mitochondrion is an essential organelle important for the generation of ATP for cellular function. This is especially critical for cells with high energy demands, such as neurons for signal transmission and cardiomyocytes for the continuous mechanical work of the heart. However, deleterious reactive oxygen species are generated as a result of mitochondrial electron transport, requiring a rigorous activation of antioxidative defense in order to maintain homeostatic mitochondrial function. Indeed, recent studies have demonstrated that the dysregulation of antioxidant response leads to mitochondrial dysfunction in human degenerative diseases affecting the nervous system and the heart. In this review, we outline and discuss the mitochondrial and oxidative stress factors causing degenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, Huntington’s disease, and Friedreich’s ataxia. In particular, the pathological involvement of mitochondrial dysfunction in relation to oxidative stress, energy metabolism, mitochondrial dynamics, and cell death will be explored. Understanding the pathology and the development of these diseases has highlighted novel regulators in the homeostatic maintenance of mitochondria. Importantly, this offers potential therapeutic targets in the development of future treatments for these degenerative diseases.

BackgroundCardiovascular disease (CVD) is a major cause of morbidity and mortality in adults with type 2 diabetes mellitus (T2DM). Cardiac dysfunction and decreased exercise capacity are common in people with T2DM, even in those without overt heart failure. Empagliflozin, a sodium-glucose co-transporter 2 (SGLT2) inhibitor, reduces major cardiovascular events and mortality in people with T2DM and established CVD, though the underlying mechanisms are not fully elucidated. This study aimed to assess changes in cardiac function and cardiorespiratory fitness (CRF) at rest and during exercise with empagliflozin treatment in people with T2DM.MethodsThis double-masked, single-centre, randomised, placebo-controlled analysis combined two studies involving adults (≥ 18 years) with T2DM comparing empagliflozin 25 mg daily vs. placebo, each over three months. VO₂ peak was measured using a ramp protocol peak exercise test on a bicycle ergometer, and echocardiography assessed changes in cardiac structure and function.ResultsOf 65 recruited participants, 57 completed the study (70.2% male, age 64.9 ± 7.8 year, baseline HbA1c 7.8% (7.5–8.4). Thirty-one participants (67.7% male, age 65.6 ± 6.6 year) were randomised to the placebo group, and 26 participants (73.1% male, age 64.2 ± 9.0 year) were randomised to empagliflozin. No significant between-group difference in the primary outcome of change in VO2 peak was observed. Empagliflozin reduced left ventricular end-diastolic volume (LVEDV) at rest by 9.508 ± 14.54 mL compared with placebo, which increased by 2.13 ± 20.73 mL (p = 0.0232).ConclusionsIn adults with T2D, 12 weeks of empagliflozin significantly reduced LVEDV without changing VO2 peak. Empagliflozin may enhance cardiovascular efficiency without directly improving functional capacity.Trial registrationACTRN12617000490370p & ACTRN12619000887178.Graphical Abstract

Background Relative telomere length (rTL), a biomarker of biological ageing, has been implicated in type 2 diabetes and its complications. We aimed to identify the associates of rTL change over 4 years (∆rTL), and to investigate whether rTL and ∆rTL are associated with complications and mortality in adults with type 2 diabetes from the Australian observational community-based Fremantle Diabetes Study Phase II (FDS2). Methods Participants (n = 819) from the FDS2 cohort had baseline and Year-4 (mean ± SD 4.2 ± 0.4 years) rTL measured by qPCR (intra- and inter-assay %CV: 0.56% and 2.69%, respectively). The rTL change (∆rTL; % change/year) was categorised as Shortened (< − 2.69%), Unchanged (− 2.69% to + 2.69%) or Lengthened (> + 2.69%). Multiple logistic regression identified clinical and biochemical determinants of ∆rTL Shortened versus Not Shortened (Unchanged plus Lengthened). rTL and ∆rTL (continuous and categorical) were added to Cox and competing risk regression models of conventional predictors of major complications, CVD death and all-cause mortality during a mean ± SD 11.5 ± 2.1 years of follow-up. Results rTL was inversely correlated with age ( r  = − 0.186, P  < 0.001). ∆rTL was shortened in 25.5% subjects, unchanged in 10.5%, and lengthened in 64.0%. Shortening was associated with older age, male sex, smoking, obesity, lipid-modifying drug use, and higher platelet count and serum bilirubin levels ( P  < 0.05). There were no statistically significant unadjusted or age- and sex-adjusted associations between baseline rTL, Year-4 rTL, or ∆rTL, and any incident micro- or macrovascular complications. In unadjusted Cox regression, ∆rTL lengthening was associated with a lower risk of CVD death (hazard ratio 0.98 (0.97, 0.99), P  = 0.042) but this association became non-significant after adjustment for conventional risk factors. Conclusions In adults with type 2 diabetes, rTL does not always shorten over time. rTL and ∆rTL were associated with baseline conventional cardiometabolic risk factors but not independently with major incident complications. There was a weak association between ∆rTL and CVD mortality. These findings question the utility of rTL and ∆rTL in usual type 2 diabetes care.

IntroductionSodium-glucose co-transporter inhibitors have potential glycaemic and non-glycaemic benefits in people with type 1 diabetes (T1D). However, the increased risk of diabetic ketoacidosis (DKA) limits their widespread use. We hypothesise that dapagliflozin 10 mg daily, combined with the use of continuous ketone monitoring (CKM) and education strategies to mitigate progression to DKA, will demonstrate improved glycaemic control without increasing DKA events.Methods and analysisPARTNER is a multisite 6-month randomised crossover double-masked study involving Australian adults with T1D who have a Haemoglobin A1c (HbA1c) <85.8 mmol/mol (<10%), minimum total daily insulin dose ≥0.4 IU/kg, consume ≥100 g carbohydrates/day and have not had DKA in the last 3 months. All participants will undergo a 2-week run-in period wearing the Abbott FreeStyle Libre 2 Continuous Glucose Monitor (CGM) and Abbott CKM device. Following this, participants are randomised to receive dapagliflozin or placebo for 12 weeks, followed by crossover for a further 12 weeks separated by a 2-week washout period. The primary effectiveness outcome is the Abbott FreeStyle Libre 2 CGM time in range during the final 2 weeks of each stage. The primary safety outcome is the number of episodes of DKA requiring hospitalisation or emergency department presentation. 60 participants will be recruited across five sites.Ethics and disseminationThe study has received ethical approval from the St Vincent’s Hospital Melbourne Human Research Ethics Committee (HREC reference 302/23). The results will be published in peer-reviewed journals and presented at national and international diabetes conferences.Trial registration numberACTRN12624000448549.

X-ray free-electron lasers provide novel opportunities to conduct single particle analysis on nanoscale particles. Coherent diffractive imaging experiments were performed at the Linac Coherent Light Source (LCLS), SLAC National Laboratory, exposing single inorganic core-shell nanoparticles to femtosecond hard-X-ray pulses. Each facetted nanoparticle consisted of a crystalline gold core and a differently shaped palladium shell. Scattered intensities were observed up to about 7 nm resolution. Analysis of the scattering patterns revealed the size distribution of the samples, which is consistent with that obtained from direct real-space imaging by electron microscopy. Scattering patterns resulting from single particles were selected and compiled into a dataset which can be valuable for algorithm developments in single particle scattering research. Design Type(s) single particle analysis • Nanoparticle Physical Characterization Measurement Type(s) X-ray diffraction data Technology Type(s) X-ray free electron laser Factor Type(s) Machine-accessible metadata file describing the reported data (ISA-Tab format)

Friedreich’s ataxia is a cardio- and neurodegenerative disease due to decreased expression of the mitochondrial protein, frataxin. This defect results in mitochondrial iron-overload, and in this review, we discuss the mechanisms that lead to this iron accumulation. Using a conditional knockout mouse model where frataxin is deleted in the heart, it has been shown that this mutation leads to transferrin receptor-1 upregulation, resulting in increased iron uptake from transferrin. There is also marked downregulation of ferritin that is required for iron storage and decreased expression of the iron exporter, ferroportin1, leading to decreased cellular iron efflux. The increased mitochondrial iron uptake is facilitated by upregulation of the mitochondrial iron transporter, mitoferrin2. This stimulation of iron uptake probably attempts to rescue the deficit in mitochondrial iron metabolism that is due to downregulation of mitochondrial iron utilization, namely, heme and iron–sulfur cluster (ISC) synthesis and also iron storage (mitochondrial ferritin). The resultant decrease in heme and ISC synthesis means heme and ISCs are not exiting the mitochondrion for cytosolic use. Hence, increased mitochondrial iron uptake coupled with decreased utilization and release leads to mitochondrial iron-loading. More generally, disturbance of mitochondrial iron utilization in other diseases probably also results in similar compensatory alterations.