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The effect of ventricular dominance and previous atrioventricular valve (AVV) surgery on patient outcomes after Fontan operation remains unclear. We sought to determine the effect of ventricular dominance and previous AVV surgery on transplantation-free survival and long-term AVV competency in patients with atrioventricular septal defect (AVSD) and Fontan circulation.We conducted a retrospective study of 1703 patients in the Australia and New Zealand Fontan Registry, who survived Fontan operation between 1987 and 2021.Of 174 patients with AVSD, 60% (105/174) had right ventricular (RV) dominance and 40% (69/174) had left ventricular (LV) dominance. The cumulative incidence of moderate or greater AVV regurgitation at 25 years after Fontan operation in patients with LV dominance was 56% (95% CI, 35%-72%), compared with 54% (95% CI, 40%-67%) in patients with RV dominance (P = .6). Nonetheless, transplantation-free survival at 25 years in patients with LV dominance was 94% (95% CI, 86%-100%), compared with 67% (95% CI, 52%-87%) in patients with RV dominance (hazard ratio, 5.9; 95% CI, 1.4-25.4; P .01). Of note, transplantation-free survival was not different in patients who underwent AVV surgery before or at Fontan completion compared with those who did not (15 years: 81% [95% CI, 62%-100%] vs 88% [95% CI, 81%-95%]; P = .3).In patients with AVSD and Fontan circulation the rate of moderate or greater common AVV regurgitation is similar in those with LV and RV dominance. RV dominance, rather than previous AVV surgery, is a risk factor for death or transplantation.

Hexagonal boron nitride (h-BN) nanosheets are grown at room temperature by pulsed laser deposition that exhibits remarkable functional properties, creating a scenario for “h-BN on demand” under a frugal thermal budget, essential for nanotechnology.

Atrioventricular valve (AVV) regurgitation is increasingly prevalent in patients with a Fontan circulation.We sought to determine the impact of ventricular dominance and AVV operation on outcomes in patients with a Fontan circulation and ≥moderate AVV regurgitation.We conducted a retrospective study, including propensity score matching analysis, of 1,703 patients who survived Fontan operation in Australia and New Zealand from 1987 to 2021.Patients undergoing AVV operation were more likely to have right ventricular (RV) dominance or an atrioventricular septal defect. In the entire cohort, death or transplantation after Fontan operation was significantly higher in patients who underwent AVV operation before or at Fontan completion compared with those who did not (20 years: 18%; 95% CI: 8%-26% vs 13%; 95% CI: 10%-15%; P = 0.03). After propensity score matching, including for RV dominance, there was no significant difference in death or transplantation between the groups (20 years: 18%; 95% CI: 8%-26% vs 16%; 95% CI: 10%-22%; P = 0.41). Only patients with RV dominance who developed ≥moderate AVV regurgitation after Fontan operation were at increased risk of death or transplantation (HR: 2.8; 95% CI: 1.4-5.3; P 0.01). In patients with left ventricular dominance, there was no significant difference in death or transplantation between patients with ≥moderate AVV regurgitation compared with those with moderate regurgitation (P = 0.8).RV dominance, but not AVV surgery itself, was associated with poor outcomes. Moderate or greater AVV regurgitation after Fontan operation is associated with a significantly increased risk of death or transplantation, only in patients with RV dominance.

Wide and ultrawide-bandgap semiconductors lie at the heart of next-generation high-power, high-frequency electronics. Here, we report the growth of ultrawide-bandgap boron nitride (BN) thin films on wide-bandgap gallium nitride (GaN) by pulsed laser deposition. Comprehensive spectroscopic (core level and valence band XPS, FTIR, Raman) and microscopic (AFM and STEM) characterizations confirm the growth of BN thin films on GaN. Optically, we observed that BN/GaN heterostructure is second-harmonic generation active. Moreover, we fabricated the BN/GaN heterostructure-based Schottky diode that demonstrates rectifying characteristics, lower turn-on voltage, and an improved breakdown capability (234 V) as compared to GaN (168 V), owing to the higher breakdown electrical field of BN. Our approach is an early step towards bridging the gap between wide and ultrawide-bandgap materials for potential optoelectronics as well as next-generation high-power electronics., 5 Figures, Published in Applied Physics Letters

Patients with aortic atresia (AA) have the worst prognosis in the spectrum of hypoplastic left heart syndrome (HLHS). It remains unknown if patients with AA continue to do poorly after Fontan operation. This study aimed to determine the association between AA and atrioventricular valve (AVV) function and clinical outcomes after Fontan operation in patients with HLHS.We performed a retrospective study of 1,731 patients who survived the Fontan operation from the Australia and New Zealand Fontan Registry between 1975-2020.We identified 188 patients with HLHS, including 99 (53%) with AA. Overall transplant-free survival and freedom from failure of Fontan circulation at 15-years was 91% (95%CI, 86%-96%) and 79% (95%CI, 71%-88%). The cumulative incidence of AVV operation at 15-years of age for patients with AA and aortic stenosis (AS) was 28% (95%CI, 19%-38%) and 14% (95%CI, 7%-22%, p=0.03). The cumulative incidence of AVV failure (≥moderate regurgitation or AVV operation) at 15-years of age for patients with AA and AS was 50% (95%CI, 37%-61%) and 30% (95%CI, 19%-42%, p=0.01). Patients with AVV failure were at increased risk of developing ≥moderately decreased systolic ventricular function (OR 6.7, 95%CI 1.7-33, p=0.01) and failure of Fontan circulation (HR 3.7, 95%CI 1.5-9.1, p0.01).In patients with HLHS, there is no significant difference in transplant-free survival after Fontan operation in patients with AA and AS. However, patients with AA have a much higher burden of AVV failure than those with AS. AVV failure is associated with failure of Fontan circulation.

Two-dimensional van der Waals (2D-vdW) layered hexagonal boron nitride (h-BN) has gained tremendous research interest over recent years due to its unconventional domain growth morphology, fascinating properties and application potentials as an excellent dielectric layer for 2D-based nano-electronics. However, the unidirectional domain growth of h-BN thin films directly on insulating substrates remains significantly challenging because of high-bonding anisotropicity and complex growth kinetics than the conventional thin films growth, thus resulting in the formation of randomly oriented domains morphology, and hindering its usefulness in integrated nano-devices. Here, ultra-wide bandgap h-BN thin films are grown directly on low-miscut atomically smooth highly insulating c-plane sapphire substrates (without using any metal catalytic layer) by pulsed laser deposition, showing remarkable unidirectional triangular-shape domains morphology. This unidirectional domain growth is attributed to the step-edge guided nucleation caused by reducing the film-substrate interfacial symmetry and energy, thereby breaking the degeneracy of nucleation sites of random domains, as revealed by the density functional theory (DFT) calculations. Through extensive characterizations, we further demonstrate the excellent single crystal-like functional properties of films. Our findings might pave the way for feasible large-area direct growth of electronic-quality h-BN thin films on insulating substrates for high-performance 2D-electronics, and in addition would be beneficial for hetero engineering of 2D-vdW materials with emergent phenomena., Comment: 39 pages, 7 figures, Revised accepted version of the article

Hexagonal boron nitride (h-BN) has emerged as a strong candidate for two-dimensional (2D) material owing to its exciting optoelectrical properties combined with mechanical robustness, thermal stability, and chemical inertness. Super-thin h-BN layers have gained significant attention from the scientific community for many applications, including nanoelectronics, photonics, biomedical, anti-corrosion, and catalysis, among others. This review provides a systematic elaboration of the structural, electrical, mechanical, optical, and thermal properties of h-BN followed by a comprehensive account of state-of-the-art synthesis strategies for 2D h-BN, including chemical exfoliation, chemical, and physical vapor deposition, and other methods that have been successfully developed in recent years. It further elaborates a wide variety of processing routes developed for doping, substitution, functionalization, and combination with other materials to form heterostructures. Based on the extraordinary properties and thermal-mechanical-chemical stability of 2D h-BN, various potential applications of these structures are described.

Selective solvent and solute transport across nanopores is fundamental to membrane separations, yet it remains poorly understood, especially for non-aqueous systems. Here, we design a chemically robust nanoporous graphene membrane and study molecular transport in various organic liquids under subnanometre confinement. We show that the nature of the solvent can modulate solute diffusion across graphene nanopores, and that breakdown of continuum flow occurs when pore size approaches the solvent's smallest molecular cross-section. By holistically engineering membrane support, modelling pore creation and defect management, high rejection and ultrafast organic solvent nanofiltration of dye molecules and separation of hexane isomers are achieved. The membranes exhibit stable fluxes across a range of solvents, consistent with flow across rigid pores whose size is independent of the solvent. These results demonstrate that nanoporous graphene is a rich materials system for controlling subcontinuum flow that could enable new membranes for a range of challenging separation needs.

A brief overview of quantum materials and their prospects for applications, in the near, mid, and far-term in the areas of quantum information science, spintronics, valleytronics, and twistronics and those involving topology are covered in this perspective. The material and processing challenges that will modulate the realism of the applications will be discussed as well.