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The discovery of superconductivity in doped infinite‐layer nickelate thin films has brought increased attention to the behavior of the doped perovskite phase. Despite this interest, the majority of existing studies pertain to hole‐doped perovskite rare‐earth nickelate thin films, while most electron‐doping studies have been performed on bulk materials so far. To tackle this imbalance, a detailed study that addresses doping of NdNiO3 thin films using A‐site substitution is presented, using Pb as a dopant and taking advantage of its valence‐skipping nature. Through a combination of complementary techniques including X‐ray diffraction, transport measurements, X‐ray absorption spectroscopy, electron energy‐loss spectroscopy and scanning transmission electron microscopy, the valence of Pb in the Nd1−xPbxNiO3 structure is confirmed to be 4+, and the behavior of the doped thin films is found to be controlled by a competition between carrier injection and structural distortions, which respectively reduce and increase the metal‐to‐insulator transition temperature. This work provides a systematic study of electron doping in NdNiO3, demonstrating that A‐site substitution with Pb is an appropriate method for such doping in perovskite rare‐earth nickelate systems. [ABSTRACT FROM AUTHOR]

The power of a large clinical trial can be adversely affected by low recruitment, follow‐up, and adherence rates. External pilot trials estimate these rates and use them, via prespecified decision rules, to determine if the definitive trial is feasible and should go ahead. There is little methodological research underpinning how these decision rules, or the sample size of the pilot, should be chosen. In this article we propose a hypothesis test of the feasibility of a definitive trial, to be applied to the external pilot data and used to make progression decisions. We quantify feasibility by the power of the planned trial, as a function of recruitment, follow‐up, and adherence rates. We use this measure to define hypotheses to test in the pilot, propose a test statistic, and show how the error rates of this test can be calculated for the common scenario of a two‐arm parallel group definitive trial with a single normally distributed primary endpoint. We use our method to redesign TIGA‐CUB, an external pilot trial comparing a psychotherapy with treatment as usual for children with conduct disorders. We then extend our formulation to include using the pilot data to estimate the standard deviation of the primary endpoint and incorporate this into the progression decision. [ABSTRACT FROM AUTHOR]

External pilot trials of complex interventions are used to help determine if and how a confirmatory trial should be undertaken, providing estimates of parameters such as recruitment, retention, and adherence rates. The decision to progress to the confirmatory trial is typically made by comparing these estimates to pre-specified thresholds known as progression criteria, although the statistical properties of such decision rules are rarely assessed. Such assessment is complicated by several methodological challenges, including the simultaneous evaluation of multiple endpoints, complex multi-level models, small sample sizes, and uncertainty in nuisance parameters. In response to these challenges, we describe a Bayesian approach to the design and analysis of external pilot trials. We show how progression decisions can be made by minimizing the expected value of a loss function, defined over the whole parameter space to allow for preferences and trade-offs between multiple parameters to be articulated and used in the decision-making process. The assessment of preferences is kept feasible by using a piecewise constant parametrization of the loss function, the parameters of which are chosen at the design stage to lead to desirable operating characteristics. We describe a flexible, yet computationally intensive, nested Monte Carlo algorithm for estimating operating characteristics. The method is used to revisit the design of an external pilot trial of a complex intervention designed to increase the physical activity of care home residents. [ABSTRACT FROM AUTHOR]

Melt size‐dependent physical property variation is examined in a multicomponent GeSe2‐As2Se3‐PbSe chalcogenide glass developed for gradient refractive index applications. The impact of melting conditions on small (40 g) prototype laboratory‐scale melts extended to commercially‐relevant melt sizes (1.325 kg) have been studied and the role of thermal history variation on physical and optical property evolution in parent glass, the glass' crystallization behavior and postheat‐treated glass ceramics, is quantified. As‐melted glass morphology, optical homogeneity and heat treatment‐induced microstructure following a fixed, two‐step nucleation and growth protocol exhibit marked variation with melt size. These attributes are shown to impact crystallization behavior (growth rates, resulting crystalline phase formation) and induced effective refractive index change, neff, in the resulting optical nanocomposite. The magnitude of these changes is discussed based on thermal history related melt conditions. [ABSTRACT FROM AUTHOR]

Herein, the assembly of CsPbBr3 QD/AlO x inorganic nanocomposites, by using atomic layer deposition (ALD) for the growth of the amorphous alumina matrix (AlO x), is described as a novel protection scheme for such QDs. The nucleation and growth of AlO x on the QD surface was thoroughly investigated by miscellaneous techniques, which highlighted the importance of the interaction between the ALD precursors and the QD surface to uniformly coat the QDs while preserving the optoelectronic properties. These nanocomposites show exceptional stability towards exposure to air (for at least 45 days), irradiation under simulated solar spectrum conditions (for at least 8 h), and heat (up to 200 °C in air), and finally upon immersion in water. This method was extended to the assembly of CsPbBr xI3− x QD/AlO x and CsPbI3 QD/AlO x nanocomposites, which were more stable than the pristine QD films. [ABSTRACT FROM AUTHOR]

Despite a growing interest in two-dimensional polymers, their rational synthesis remains a challenge. The solution-phase synthesis of a two-dimensional polymer is reported. A DNA-based monomer self-assembles into a supramolecular network, which is further converted into the covalently linked two-dimensional polymer by anthracene dimerization. The polymers appear as uniform monolayers, as shown by AFM and TEM imaging. Furthermore, they exhibit a pronounced solvent responsivity. The results demonstrate the value of DNA-controlled self-assembly for the formation of two-dimensional polymers in solution. [ABSTRACT FROM AUTHOR]

Laser spectroscopy is an emerging technology for measuring nitrous oxide (N2O) dynamics in the environment, but most studies have focused on atmospheric applications. We have coupled a commercially available cavity ring-down spectroscope (CRDS) (Picarro G5101- I isotopic N2O analyzer) to an air/water gas equilibration device to collect continuous in situ dissolved N2O molar concentration and bulk nitrogen isotopic (δ15N-N2O) data. The δ15N-N2O values measured by the CRDS unit were found to be significantly affected by changes in the mixing ratios of O2, CO, CH4, and CO2. There was also an effect of N2O mixing ratio on δ15N-N2O. A series of equations was developed to correct for the matrix effect of O2 and the spectral interference by CH4. Chemical traps effectively prevented interferences by CO and CO2. The maximum corrections required for N2O mixing ratio and O2 matrix effects, were 1‰ (at a mixing ratio of 1.2 ppmv), and 11‰ (at 0% O2 content), respectively. The CH4 correction only became important at mixing ratios greater than 500 ppmv (>0.5‰). Measurements of N2O molar concentration and δ15N-N2O from the CRDS isotopic N2O analyzer were similar to those measured with isotope ratio mass spectrometry. We demonstrated the utility of the laser-based system with field deployments in three estuarine tidal creeks in subtropical Australia. Future work in this field should focus on the application of the laser-based system to the measurement of N2O isotopologues in aquatic habitats, allowing for further constraints to be placed on the pathways of N2O cycling in aquatic system. [ABSTRACT FROM AUTHOR]