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Phosphoprotein phosphatases (PPPs) regulate major signaling pathways, but the determinants of phosphatase specificity are poorly understood. This is because methods to investigate this at scale are lacking. Here, we develop a novel in vitro assay, MRBLE:Dephos, that allows multiplexing of dephosphorylation reactions to determine phosphatase preferences. Using MRBLE:Dephos, we establish amino acid preferences of the residues surrounding the dephosphorylation site for PP1 and PP2A‐B55, which reveals common and unique preferences. To compare the MRBLE:Dephos results to cellular substrates, we focused on mitotic exit that requires extensive dephosphorylation by PP1 and PP2A‐B55. We use specific inhibition of PP1 and PP2A‐B55 in mitotic exit lysates coupled with phosphoproteomics to identify more than 2,000 regulated sites. Importantly, the sites dephosphorylated during mitotic exit reveal key signatures that are consistent with MRBLE:Dephos. Furthermore, integration of our phosphoproteomic data with mitotic interactomes of PP1 and PP2A‐B55 provides insight into how binding of phosphatases to substrates shapes dephosphorylation. Collectively, we develop novel approaches to investigate protein phosphatases that provide insight into mitotic exit regulation. Synopsis: MRBLE:Dephos a new method for high‐throughput investigation of peptide dephosphorylation using spectral encoded beads. Using this method, the active site preferences of PP1 and PP2A‐B55 are investigated and compared to mitotic exit substrates identified by phosphoproteomics. MRBLE:Dephos is a novel high‐throughput dephosphorylation method.MRBLE:Dephos provides insights into PP1 and PP2A‐B55 sequence preferences.Mitotic exit substrate screens for PP1 and PP2A‐B55 identifies thousands of regulated sites.Binding of PP1 to RVxF motifs can modulate active site preferences. [ABSTRACT FROM AUTHOR]

In this paper, we study and demonstrate the performance analysis of a device-to-device (D2D) communication network. Specifically, a source node transmits data to the destination node using the power beacon's harvested energy in order to overcome the limited energy budget. Besides, an eavesdropper located in the proximal region of a source is trying to overhear secure information. Notably, both eavesdropper and destination are affected by co-channel interferences from other sources when they utilize the same frequency. By considering the above discussions, we derived the closedform expressions for outage probability (OP), intercept probability (IP), and secrecy outage probability (SOP) in connection with using the system model. The derived analytical expressions are then verified by utilizing both simulation and numerical results. Finally, the intensive parameters' influences on the OP, IP, and SOP are also investigated. [ABSTRACT FROM AUTHOR]

Black phosphorene quantum dots (BPQDs) are most commonly derived from high‐cost black phosphorus, while previous syntheses from the low‐cost red phosphorus (Pred) allotrope are highly oxidised. Herein, we present an intrinsically scalable method to produce high quality BPQDs, by first ball‐milling Pred to create nanocrystalline Pblack and subsequent reductive etching using lithium electride solvated in liquid ammonia. The resultant ~25 nm BPQDs are crystalline with low oxygen content, and spontaneously soluble as individualized monolayers in tertiary amide solvents, as directly imaged by liquid‐phase transmission electron microscopy. This new method presents a scalable route to producing quantities of high quality BPQDs for academic and industrial applications. [ABSTRACT FROM AUTHOR]

A scalable growth of atomically‐thin 2D transition metal dichalcogenides (TMDs) with defect‐free large‐area surfaces is crucial for developing high‐performing optoelectronic devices. Herein, a method to grow large‐area, high‐quality MoSe2 monolayers, MoSe2–WSe2, and WSe2–MoSe2 lateral heterostructures using molten salt‐based chemical vapor deposition (CVD) is systematically reported. First, effects of isolated inorganic (sodium chloride (NaCl) and sodium nitrate (NaNO3)), organic (Perylene–3,4,9,10–tetracarboxylic acid tetrapotassium salt (PTAS), mixed inorganic (NaCl/NaNO3), and hybrid organic–inorganic (PTAS/NaCl/NaNO3) salt catalysts on the CVD growth and optoelectronic quality of MoSe2 monolayers and their lateral heterostructures with WSe2 in MoSe2–WSe2 and WSe2–MoSe2 assemblies are investigated. Results show that molten salt catalysts (NaCl/NaNO3 and PTAS/NaCl/NaNO3) support high‐quality, large‐area growth of MoSe2 monolayers with low defect density. The mixed inorganic salt supports growth of MoSe2–WSe2 lateral heterostructures but not their counterpart. Meanwhile, WSe2–MoSe2 lateral heterostructures are optimally grown, supported by the hybrid organic–inorganic salt. These results are ascribed to the difference in the associated kinetic and thermodynamic mechanisms for the growths of MoSe2 and WSe2 as starting materials. Last, it is confirmed that optoelectronic quality of realized heterostructures and monolayers is improved compared to their mechanically exfoliated counterparts. The obtained high‐quality, large‐area 2D TMD heterostructures can be useful for various optoelectronic applications. [ABSTRACT FROM AUTHOR]

Two new xanthones, oblongixanthones I (1) and J (2), and seven known compounds (3–9), were isolated from an EtOAc extract of the twigs of Garcinia oblongifolia. Their structures were elucidated using spectroscopic methods, mainly 1 D and 2 D NMR. The antidiabetic effects of the two new compounds were evaluated using α-glucosidase and PTP1B inhibition assays. Both compounds displayed strong inhibition towards α-glucosidase with IC50 values of 258.7 ± 49.3 and 187.1 ± 27.5 μM, respectively (compared with acarbose, IC50 = 900.0 ± 3.0 μM) and moderate effects against PTP1B with IC50 values of 93.9 ± 12.3 and 64.1 ± 5.8 μM, respectively (compared with RK682, IC50 = 4.4 ± 0.3 l μM). [ABSTRACT FROM AUTHOR]

The most prominent form of nonlinear optical (NLO) frequency conversion is second harmonic generation (SHG), where incident light interacts with a nonlinear medium producing photons at double the input frequency, which has vast applications in material and biomedical science. Emerging two-dimensional nonlinear optical materials led by transition metal dichalcogenides (TMDs) have fascinating optical and mechanical properties and are highly anticipated to overcome the technical limitations imposed by traditional bulky NLO materials. However, the atomic scale interaction length and low conversion efficiency in TMD materials prevent their further implementation in NLO applications. While some uniaxial strain-engineering studies intensively investigated the anisotropic SHG response in TMDs, they did not realize giant SHG enhancement by exploiting the opto-mechanical characteristics. Herein, we employ proton (H+) irradiation to successfully fabricate large pressurized monolayer TMD domes (d ≥ 10 μm) and conduct a comprehensive investigation and characterization of their SHG performance enhancement. We show that the intensity of SHG is effectively enhanced by around two orders of magnitude at room temperature. Such giant enhancement arises from the distinct separation distance induced by capped pressurized gas and the hemi-spherical morphology, enabling constructive optical interference. Moreover, the unique divergent strain field in TMD domes promotes the first experimental study on the anisotropic nonlinear optical behavior based on biaxial strain conditions in terms of varying strain orientation and relative weights. Our work demonstrates a promising system with enhanced NLO performance and well-preserved biocompatibility, paving a way toward the future nano-scaled quantum optics design and biomedical applications. [ABSTRACT FROM AUTHOR]

Mammography, or breast X-ray imaging, is the most widely used imaging modality to detect cancer and other breast diseases. Recent studies have shown that deep learning-based computer-assisted detection and diagnosis (CADe/x) tools have been developed to support physicians and improve the accuracy of interpreting mammography. A number of large-scale mammography datasets from different populations with various associated annotations and clinical data have been introduced to study the potential of learning-based methods in the field of breast radiology. With the aim to develop more robust and more interpretable support systems in breast imaging, we introduce VinDr-Mammo, a Vietnamese dataset of digital mammography with breast-level assessment and extensive lesion-level annotations, enhancing the diversity of the publicly available mammography data. The dataset consists of 5,000 mammography exams, each of which has four standard views and is double read with disagreement (if any) being resolved by arbitration. The purpose of this dataset is to assess Breast Imaging Reporting and Data System (BI-RADS) and breast density at the individual breast level. In addition, the dataset also provides the category, location, and BI-RADS assessment of non-benign findings. We make VinDr-Mammo publicly available as a new imaging resource to promote advances in developing CADe/x tools for mammography interpretation. [ABSTRACT FROM AUTHOR]

Photoelectrochemical water splitting is a promising approach to produce green hydrogen using solar energy. A primary bottleneck remains the lack of efficient photoanodes to catalyze the sluggish water photooxidation reaction. Engineering photoabsorbers with a narrow bandgap and suitable band edge can boost the photoelectrochemical performance. Herein, nanostructured iron tungstate (FeWO4) photoanodes are engineered directly on a fluorine doped tin oxide glass substrate via a scalable and ultra-fast flame synthesis route in 13 seconds. Physiochemical, optoelectronic, and electrochemical properties of these photoanodes are systematically investigated. The key roles of charge transport, transfer, and dissolution of W and Fe ions from the FeWO4 matrix within long-term performance are revealed. Optimal FeWO4 photoanode with a bandgap of 1.82 eV and a FeOOH/NiOOH co-catalyst coating shows an improved water photooxidation performance, reaching a photocurrent density of 0.23 mA cm-2 at 1.4 V versus reversible hydrogen electrode in 1 m potassium hydroxide. It further demonstrates relatively good photostability, maintaining ≈96% of photocurrent density after 1-hour continuous photooxidation, albeit some trace of Fe, W and Ni elements dissolution. Insights on the photooxidation performance of nanostructured FeWO4 provide promising directions for the engineering of small band-gap catalysts for a variety of photoelectrochemical applications. [ABSTRACT FROM AUTHOR]

Background: Multivariate longitudinal data are under-utilized for survival analysis compared to cross-sectional data (CS - data collected once across cohort). Particularly in cardiovascular risk prediction, despite available methods of longitudinal data analysis, the value of longitudinal information has not been established in terms of improved predictive accuracy and clinical applicability. Methods: We investigated the value of longitudinal data over and above the use of cross-sectional data via 6 distinct modeling strategies from statistics, machine learning, and deep learning that incorporate repeated measures for survival analysis of the time-to-cardiovascular event in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. We then examined and compared the use of model-specific interpretability methods (Random Survival Forest Variable Importance) and model-agnostic methods (SHapley Additive exPlanation (SHAP) and Temporal Importance Model Explanation (TIME)) in cardiovascular risk prediction using the top-performing models. Results: In a cohort of 3539 participants, longitudinal information from 35 variables that were repeatedly collected in 6 exam visits over 15 years improved subsequent long-term (17 years after) risk prediction by up to 8.3% in C-index compared to using baseline data (0.78 vs. 0.72), and up to approximately 4% compared to using the last observed CS data (0.75). Time-varying AUC was also higher in models using longitudinal data (0.86–0.87 at 5 years, 0.79–0.81 at 10 years) than using baseline or last observed CS data (0.80–0.86 at 5 years, 0.73–0.77 at 10 years). Comparative model interpretability analysis revealed the impact of longitudinal variables on model prediction on both the individual and global scales among different modeling strategies, as well as identifying the best time windows and best timing within that window for event prediction. The best strategy to incorporate longitudinal data for accuracy was time series massive feature extraction, and the easiest interpretable strategy was trajectory clustering. Conclusion: Our analysis demonstrates the added value of longitudinal data in predictive accuracy and epidemiological utility in cardiovascular risk survival analysis in young adults via a unified, scalable framework that compares model performance and explainability. The framework can be extended to a larger number of variables and other longitudinal modeling methods. Trial registration: ClinicalTrials.gov Identifier: NCT00005130, Registration Date: 26/05/2000. [ABSTRACT FROM AUTHOR]

Herein, high-quality localized phosphorus-doped polycrystalline silicon (poly-Si) passivating contacts containing nanoscale poly-Si film (∼100 nm) on an ultrathin SiOx layer (∼1.5 nm) were fabricated via an inkjet printing technique. A detailed study of the impacts of inkjet printer settings, dopant concentration, and annealing temperature on the poly-Si passivating contact performance (represented by implied open-circuit voltage iVoc and contact resistivity ρc) was carried out. By applying optimized process conditions on symmetrical industrially processed intrinsic poly-Si/SiOx/n-type crystalline Si (c-Si) substrates, good surface passivation was achieved with an iVoc of 699 mV, together with a low ρc of 6.4 mΩ·cm2, after annealing at 975 °C. After a hydrogenation treatment via the deposition of aluminum oxide (AlOx)/silicon nitride (SiNy) stack and subsequent forming gas annealing (FGA), the optimum annealing temperature shifted to 950 °C and the iVoc was further improved to an excellent value of 729 mV. Optical images reveal that a line width of 75 μm can be realized on a mechanically polished silicon wafer. Moreover, high-resolution micro-photoluminescence (μ-PL) maps clearly demonstrate the localization of the doped regions on the symmetrical substrate after annealing. These results show that inkjet printing is a promising technique for the fabrication of localized poly-Si/SiOx passivating contacts in high-efficiency solar cells with high flexibility and simplicity. [ABSTRACT FROM AUTHOR]

Two new triterpenoids, entanolide (1) and methyl 3,4-secotirucalla-23-oxo-4(28),7,24-trien-21-al-3-oate (2), together with nine known compounds (3-11), were isolated from the bark of Entandrophragma angolense. Their structures were elucidated based on spectroscopic analyses, mainly 1 D and 2 D NMR spectral data. Compounds 1-6 and 8 were evaluated for their cytotoxicity against HepG2 cells, and compounds 2-5 exhibited weak activities. [ABSTRACT FROM AUTHOR]

Two new polyisoprenylated benzophenones, planchoniones A (1) and B (2), together with two known benzophenones (3, 4) and six known xanthones (5-10), were isolated from an ethyl acetate extract of the pericarp of Garcinia planchonii Pierre. Their structures were established using spectroscopic methods, mainly 1D and 2D NMR. The four benzophenones were evaluated for their cytotoxicity against MCF-7 human breast cancer cells, and showed almost no activity. Meanwhile, compounds 5-10 were investigated for their inhibitory effects towards α-glucosidase, and γ-mangostin (5) exhibited the most remarkable effect with IC50 value of 15.3 ± 0.9 µM (compared with acarbose, IC50 = 224.9 ± 3.6 µM). [ABSTRACT FROM AUTHOR]

We investigated ring defects induced by a two-step anneal in n-type Czochralski-grown silicon wafers using a combination of high spatial resolution Fourier Transform Infrared Spectroscopy (FTIR), micro-photoluminescence (PL) mapping, and micro-Raman mapping. Through FTIR measurements, we show the inhomogeneous loss in interstitial oxygen with a positive correlation with the inverse lifetime. Using high-resolution micro-PL mapping, we are able to distinguish individual recombination-active oxygen precipitates within the rings with a decreasing density from the center to the edge of the sample. The radial inhomogeneity of the oxygen precipitates is likely to be related to variations in the distribution of grown-in defects. We also demonstrate that micro-Raman mapping reveals the oxygen precipitates without the smearing effects of carrier diffusion that are present in micro-PL mapping. [ABSTRACT FROM AUTHOR]

Atomically thin two‐dimensional (2D) transition metal dichalcogenides (TMDs) are promising materials for photovoltaic (PV) applications. Their self‐terminated nature and strong absorption characteristics introduce an unprecedented possibility for high voltages to bandgap ratios, with secondary benefits including the potential for high internal quantum efficiencies/low recombination and strong absorption coefficients coupled with stability in a range of environments. However, despite the promise of such material systems, their PV performances still lag behind the conventional 3D materials. In principle, one possible way to manipulate the behavior of a 2D heterobilayer structure is to change its interlayer twist angle. In this study, the effects of twist angle between vertically stacked type‐II MoS2/WS2 heterobilayers on fundamental optical properties such as light absorbance, excess carrier lifetime, and diffusion are reported. These properties can have a direct effect on the final PV performance of these heterobilayers. It is found that the interlayer twist in MoS2/WS2 heterobilayers does not affect their absorbance. However, the carrier lifetime and photon emission across the heterobilayers are modulated with the interlayer twist. These findings could be useful to facilitate the optimization of monolayer TMD‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]

High bandgap perovskite solar cells are integral to perovskite‐based multi‐junction tandem solar cells with efficiency potentials over 40%. However, at present, high bandgap perovskite devices underperform compared to their mid bandgap counterparts in terms of voltage outputs and fill factors resulting in lower than ideal efficiencies. Here, the low fill factor aspect of high bandgap perovskite is addressed by developing a cation‐diffusion‐based double‐sided interface passivation scheme that simultaneously provides bulk passivation for a 1.75 eV perovskite cell that is also compatible with a p‐i‐n cell architecture. The champion cell achieves a record fill factor of 86.5% and a power conversion efficiency of 20.2%. Results of ionic distribution profiling, Fourier transform infrared spectroscopy, and X‐ray diffraction crystallography reveal evidence of cation diffusion from the surface perovskite passivation layer into bulk. The diffused cations reduce Shockley–Read–Hall recombination in the perovskite bulk and at the surfaces with the latter being more dominant as confirmed by light‐intensity dependent and temperature‐dependent open‐circuit voltage measurements as well as thermal admittance spectroscopy. This concurrent bulk and surface passivation scheme renders record fill factor and efficiency in the double‐side passivated cells. This provides new insights for future passivation strategies based on ionic diffusion of functionalized materials. [ABSTRACT FROM AUTHOR]

Catalyst‐free InGaAs nanowires are promising building blocks for optoelectronic devices operating at telecommunication wavelengths. Despite progress, the applications of InGaAs nanowires remain limited due to their high density of surface states that degrade their optical properties. Here, InGaAs nanowires with superior optical properties are achieved by effectively suppressing their surface states with an InP passivation shell. Optimal InP shell growth conditions and thickness to maximize the minority carrier lifetime are identified. The photoluminescence intensity of these passivated InGaAs nanowires is up to three orders of magnitude higher than that of their bare counterparts. Moreover, a long minority carrier lifetime of up to ≈13 ns is measured with these passivated nanowires at room temperature. Optimal passivation of InGaAs nanowires with an emission wavelength of 1530 nm results in an ultra‐low surface recombination velocity of ≈280 cm s−1. In addition to the shell, the crystal structure of these nanowires plays an important role in the luminescence intensity. Combined cathodoluminescence mapping and high‐resolution transmission electron microscopy along the nanowires reveal significantly lower emission intensities in wurtzite predominant sections of the nanowires than zinc blende predominant ones.These insights on the optimal passivation of InGaAs provide directions for engineering high‐performance nanoscale‐devices in the telecommunication wavelength. [ABSTRACT FROM AUTHOR]

This work compares the firing response of ex‐situ doped p‐ and n‐type polysilicon (poly‐Si) passivating contacts and identifies possible mechanisms underlying their distinct firing behavior. The p‐type poly‐Si shows greater firing stability than n‐type poly‐Si, particularly at a higher firing temperature, which results in a substantial increase in the recombination current density parameter J0 from 9 to 96 fA/cm2 upon firing at 900°C for n‐type poly‐Si, in comparison to an increase from 11 to 30 fA/cm2 for p‐type poly‐Si. It is observed that p‐type poly‐Si contacts only suffer a slight degradation or even exhibit a small improvement in J0 after firing at 800°C, depending on the boron diffusion temperature. Secondary ion mass spectrometry (SIMS) results demonstrate that the hydrogen concentration near the interfacial SiOx increases with the peak firing temperature in n‐type poly‐Si, whereas the hydrogen profile remains unchanged for p‐type poly‐Si upon firing at various temperatures. Moreover, we observe that injecting additional hydrogen into the poly‐Si/SiOx stacks fired with SiNx coating layers further degrades n‐type poly‐Si, but recovers the J0 of p‐type poly‐Si to the value before firing. In contrast, removing hydrogen from the fired poly‐Si/SiOx stacks leads to an initial recovery and then a second degradation of J0 in n‐type poly‐Si, but no substantial impact on p‐type poly‐Si. It is hypothesized that the distinct difference in the firing impact on p‐ and n‐type poly‐Si is related to the different effective hydrogen diffusivity, which determines the hydrogen content surrounding the SiOx layer and hence the passivation quality after firing. [ABSTRACT FROM AUTHOR]

Hybrid organic–inorganic perovskite solar cells (PSCs) are one of the most promising candidates for next generation photovoltaics. Further improvement in their performance, particularly efficiency, durability and reproducibility, requires a deep understanding of recombination losses during fabrication and within a device itself. In this work, we report a contactless, imaging‐based procedure to spatially resolve electronic properties of PSCs including implied open‐circuit voltage (iVoc) and its temperature coefficient, ideality factor (nid) and activation energy of recombination (EA) by employing illumination intensity and temperature‐dependent photoluminescence. The illumination intensity dependence of iVoc allows the extraction of nid whereas its temperature dependence allows the extraction of the temperature coefficient and EA. This imaging approach is then applied to investigate changes of these electronic parameters on fully and partially fabricated devices. [ABSTRACT FROM AUTHOR]

Objective: The study aimed to evaluate the indications and describe the aortic valve reconstruction techniques by Ozaki's procedure in Vietnam and report mid‐term outcomes of this technique in Vietnam. Methods: Between June 2017 and December 2019, 72 patients diagnosed with isolated aortic valve disease, with a mean age of 52.9 (19–79 years old), and a male:female ratio of 3:1 underwent aortic valve reconstruction surgery by Ozaki's technique at Cardiovascular Center, E Hospital, Vietnam. Results: The aortic valve diseases consisted of aortic stenosis (42%), aortic regurgitation (28%), and a combination of both (30%). In addition, the proportion of aortic valves with bicuspid morphology and small annulus (≤21 mm) was 28% and 38.9%, respectively. The mean aortic cross‐clamp time was 106 ± 13.8 min, mean cardiopulmonary bypass time was 136.7 ± 18.5 min, and 2.8% of all patients required conversion to prosthetic valve replacement surgery. The mean follow‐up time was 26.4 months (12–42 months), the survival rate was 95.8%, the reoperation rate was 2.8%, and rate of postoperative moderate or higher aortic valve regurgitation was 4.2%. Postoperative valvular hemodynamics was favorable, with a peak pressure gradient of 16.1 mmHg and an effective orifice area index of 2.3 cm2. Conclusions: This procedure was safe and effective, with favorable valvular hemodynamics and a low rate of valvular degeneration. However, more long‐term follow‐up data are needed. [ABSTRACT FROM AUTHOR]

This work presents the OH-initiated oxidation kinetics of 1,4-cyclochexadiene (1,4-CHD). The temperature dependence of the reaction was investigated by utilizing a laser flash photolysis flow reactor and laser-induced fluorescence (LPFR/LIF) technique over the temperature range of 295–438 K and a pressure of ∼50 torr. The kinetics of the reaction was followed by measuring the LIF signal of OH radicals near 308 nm. The reaction of OH radicals with 1,4-CHD exhibited a clear negative temperature dependence. To discern the role of various channels, ab initio and RRKM-based ME calculations (RRKM-ME) were performed over temperatures of 200–2000 K and pressures of 0.76–7600 torr. The computed energy profile revealed that the reaction proceeds via the formation of a pre-reaction van der Waals complex at the entrance channel. The complex was found to be more stable than that usually seen in other alkenes + OH reactions. Both the addition channel and the abstraction reaction of allylic hydrogen were found to have negative energy barriers. Interestingly, the abstraction reaction exhibited a negative temperature dependence at low temperatures and contributed significantly (∼37%) to the total rate coefficients even under atmospheric conditions. At T ≥ 900 K, the reaction was found to proceed exclusively (>95%) via the abstraction channel. Due to the competing channels, the reaction of OH radicals with 1,4-CHD displays complicated kinetic behaviours, reflecting the salient features of the energy profile. The role of competing channels was fully characterized by our kinetic model. The calculated rate coefficients showed excellent agreement with the available experimental data. [ABSTRACT FROM AUTHOR]

Catalyst-free InGaAs nanowires grown by selective area epitaxy are promising building blocks for future optoelectronic devices in the infrared spectral region. Despite progress, the role of pattern geometry and growth parameters on the composition, microstructure, and optical properties of InGaAs nanowires is still unresolved. Here, we present an optimised growth parameter window to achieve highly uniform In1−xGaxAs nanowire arrays on GaAs (111)B substrate over an extensive range of Ga concentrations, from 0.1 to 0.91, by selective-area metal-organic vapor-phase epitaxy. We observe that the Ga content always increases with decreasing In/(Ga+In) precursor ratio and group V flow rate and increasing growth temperature. The increase in Ga content is supported by a blue shift in the photoluminescence peak emission. The geometry of the nanowire arrays also plays an important role in the resulting composition. Notably, increasing the nanowire pitch size from 0.6 to 2 µm in a patterned array shifts the photoluminescence peak emission by up to 120 meV. Irrespective of these growth and geometry parameters, the Ga content determines the crystal structure, resulting in a predominantly wurtzite structure for xGa ≤ 0.3 and a predominantly zinc blende phase for xGa ≥ 0.65. These insights on the factors controlling the composition of InGaAs nanowires grown by a scalable catalyst-free approach provide directions for engineering nanowires as functional components of future optoelectronic devices. [ABSTRACT FROM AUTHOR]

Perovskite solar cells are a potential game changer for the photovoltaics industry, courtesy of their facile fabrication and high efficiency. Despite this, commercialization is being held back by poor stability. To become economically feasible for commercial production, perovskite solar cells must meet or exceed industry standards for operational lifetime and reliability. In this regard, mixed dimensional 2D‐3D perovskite solar cells, incorporating long carbon‐chain organic spacer cations, have shown promising results, with enhancement in both device efficiency and stability. Dimensional engineering of perovskite films requires a delicate balance of 2D and 3D perovskite composition to take advantage of the specific properties of each material phase. This review summarizes and assesses the current understanding, and apparent contradictions in the state‐of‐the‐art mixed dimensional perovskite solar cell literature regarding the origin of stability and performance enhancement. By combining and comparing results from experimental and theoretical studies it is focused on how the perovskite composition, film formation methods, additive and solvent engineering influence efficiency and stability, and identify future research directions to further improve both key performance metrics. [ABSTRACT FROM AUTHOR]

A doping technique for p‐type poly‐Si/SiOx passivating contacts using a spin‐on method for different mixtures of Ga and B glass solutions is presented. Effects of solution mixing ratios on the contact performance (implied open circuit voltage iVoc, contact resistivity ρc) are investigated. For all as‐annealed samples at different drive‐in temperatures, increasing the percentage of Ga in the solution shows a decrement in iVoc (from ∼680 to ∼610 mV) and increment in ρc (from ∼3 to ∼800 mΩ cm2). After a hydrogenation treatment by depositing a SiNx/AlOx stack followed by forming gas annealing, all samples show improved iVoc (∼700 mV with Ga‐B co‐doped, and ∼720 mV with all Ga). Interestingly, when co‐doping Ga with B, even a small amount of B in the mixing solution shows negative effects on the surface passivation. Active and total dopant profiles obtained by electrical capacitance voltage and secondary‐ion mass spectrometry measurements, respectively, reveal a relatively low percentage of electrically‐active Ga and B in the poly‐Si and Si layers. These results help understand the different features of the two dopants: a low ρc with B, a good passivation with Ga, their degree of activation inside the poly‐Si and Si layers, and the annealing effects. [ABSTRACT FROM AUTHOR]

This paper proposes a modeling approach for characterizing the probability of wildfire ignition caused by faults on power distribution systems. The proposed model serves as a starting point in research literature to illustrate, from an analytical perspective, the many factors that influence wildfire ignitions in power distribution systems. This paper presents the series of events that leads to power-system-related wildfire ignitions, and characterizes the wildfire ignition probability as a combination of the probability that a fault occurs along a power distribution line segment, and the probability that the fault results in the sustained ignition of a vegetation fuel bed surrounding the line. The proposed model integrates a variety of data including environmental conditions, power system protection settings, and power system line flows. A case study is performed on a test 33-bus distribution system using observed historical weather data from a high-threat fire district in California. The California case study is utilized to investigate the effects of three primary factors (wind speed, line congestion, and protection settings) on wildfire ignition probability. [ABSTRACT FROM AUTHOR]

Scene Walk is a video viewing technique suited to first-person video recorded from wearable cameras. It integrates a 2D video player and visualisation of the camera trajectory into a non-photorealistic partial rendering of the 3D environment as reconstructed from image content. Applications include forensic analysis of first-person video archives, for example as recorded by emergency response teams. The Scene Walk method is designed to support the viewer's construction and application of a cognitive map of the context in which first-person video was captured. We use methods from wayfinding research to assess the effectiveness of this non-photorealistic approach in comparison to actual physical experience of the scene. We find that Scene Walk does allow viewers to create a more accurate and effective cognitive map of first-person video than is achieved using a conventional video browsing interface and that this model is comparable to actually walking through the original environment. [ABSTRACT FROM AUTHOR]

Tonotopy is a prominent feature of the vertebrate auditory system and forms the basis for sound discrimination, but the molecular mechanism that underlies its formation remains largely elusive. Ephrin/Eph signaling is known to play important roles in axon guidance during topographic mapping in other sensory systems, so we investigated its possible role in the establishment of tonotopy in the mouse cochlear nucleus. We found that ephrin‐A3 molecules are differentially expressed along the tonotopic axis in the cochlear nucleus during innervation. Ephrin‐A3 forward signaling is sufficient to repel auditory nerve fibers in a developmental stage‐dependent manner. In mice lacking ephrin‐A3, the tonotopic map is degraded and isofrequency bands of neuronal activation upon pure tone exposure become imprecise in the anteroventral cochlear nucleus. Ephrin‐A3 mutant mice also exhibit a delayed second wave in auditory brainstem responses upon sound stimuli and impaired detection of sound frequency changes. Our findings establish an essential role for ephrin‐A3 in forming precise tonotopy in the auditory brainstem to ensure accurate sound discrimination. [ABSTRACT FROM AUTHOR]

Dimensional engineering of perovskite films is a promising pathway to improve the efficiency and stability of perovskite solar cells (PSCs). In this context, surface or bulk passivation of defects in 3D perovskite film by careful introduction of 2D perovskite plays a key role. Here the authors demonstrate a 2D perovskite passivation scheme based on octylammonium chloride, and show that it provides both bulk and surface passivation of 1.6 eV bandgap 3D perovskite film for highly efficient (≈23.62%) PSCs with open‐circuit voltages up to 1.24 V. Surface and depth‐resolved microscopy and spectroscopy analysis reveal that the Cl− anion diffuses into the perovskite bulk, passivating defects, while the octylammonium ligands provide effective, localized surface passivation. The authors find that the Cl− diffusion into the perovskite lattice is independent of the 2D perovskite crystallization process and occurs rapidly during deposition of the 2D precursor solution. The annealing‐induced evaporation of Cl from bulk perovskite is also inhibited in 2D–3D perovskite film as compared to pristine 3D perovskite, ensuring effective bulk passivation in the relevant film. [ABSTRACT FROM AUTHOR]

Tonotopy is a prominent feature of the vertebrate auditory system and forms the basis for sound discrimination, but the molecular mechanism that underlies its formation remains largely elusive. Ephrin/Eph signaling is known to play important roles in axon guidance during topographic mapping in other sensory systems, so we investigated its possible role in the establishment of tonotopy in the mouse cochlear nucleus. We found that ephrin‐A3 molecules are differentially expressed along the tonotopic axis in the cochlear nucleus during innervation. Ephrin‐A3 forward signaling is sufficient to repel auditory nerve fibers in a developmental stage‐dependent manner. In mice lacking ephrin‐A3, the tonotopic map is degraded and isofrequency bands of neuronal activation upon pure tone exposure become imprecise in the anteroventral cochlear nucleus. Ephrin‐A3 mutant mice also exhibit a delayed second wave in auditory brainstem responses upon sound stimuli and impaired detection of sound frequency changes. Our findings establish an essential role for ephrin‐A3 in forming precise tonotopy in the auditory brainstem to ensure accurate sound discrimination. [ABSTRACT FROM AUTHOR]

Genome‐wide analysis of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) strains is essential to better understand infectivity and virulence and to track coronavirus disease 2019 (COVID‐19) cases and outbreaks. We performed whole‐genome sequencing of 27 SARS‐CoV‐2 strains isolated between January 2020 and April 2020. A total of 54 mutations in different genomic regions was found. The D614G mutation, first detected in March 2020, was identified in 18 strains and was more likely associated with a lower cycle threshold (<25) in real‐time reverse‐transcription polymerase chain reaction diagnostic tests than the original D614 (prevalence ratio = 2.75; 95% confidence interval, 1.19–6.38). The integration of sequencing and epidemiological data suggests that SARS‐CoV‐2 transmission in both quarantine areas and in the community in Vietnam occur at the beginning of the epidemic although the country implemented strict quarantine quite early, with strict contact tracing, and testing. These findings provide insights into the nature of the epidemic, as well as shape strategies for COVID‐19 prevention and control in Vietnam. [ABSTRACT FROM AUTHOR]

Early prediction of spatially resolved performance of perovskite solar cells (PSCs) is essential for process monitoring, control and fault diagnosis, and upscaling of this emerging technology. Herein, a fast, nonde structive, contactless imaging‐based approach is developed to visualize the spatial distribution of possible light current density−voltage (pseudo‐J−V) curves on finished and partly finished cells. This allows for the extraction of other critical spatially resolved properties including implied open‐circuit voltage and pseudo‐fill factor. The technique is applied to systematically investigate various degradation behaviors on PSCs including thermal stability, light soaking, and ambient air exposure. Finally, it is used to predict pseudo‐J−V curves of various perovskite films with different compositions. These results demonstrate the significant value of this fast imaging technique for the research and development of PSCs ranging from material selection, process optimization, to degradation study. [ABSTRACT FROM AUTHOR]

Crystallographic structures, optoelectronic properties, and nanoscale surface morphologies of ex situ phosphorus‐doped polycrystalline silicon (poly‐Si)/SiOx passivating contacts, formed by different deposition methods (sputtering, plasma‐enhanced chemical vapour deposition [PECVD], and low‐pressure chemical vapour deposition [LPCVD]), are investigated and compared. Across all these deposition technologies, we noted the same trend: higher diffusion temperatures yield films that are more crystalline but that have rougher surface morphologies due to bigger surface crystal grains. Also, the recrystallization process of the as‐deposited Si films starts from the SiOx interface, rather than from the film surface and bulk. However, there are some distinct differences among these technologies. First, the LPCVD method yields the lowest deposition rate, roughest surfaces, and smallest degree of crystallinity on finished poly‐Si films. In contrast, the PECVD method has the highest deposition rate and smoothest surfaces for both as‐deposited Si and annealed poly‐Si films. Second, as‐deposited sputtered and PECVD Si films contain only an amorphous phase, whereas as‐deposited LPCVD films already has some crystalline phase. Third, the LPCVD phosphorus in‐diffusion into the substrate depends strongly on the initial film thickness, whereas for the other two methods, it is weakly dependent on thickness. Finally, the passivation quality of every poly‐Si film type has different responses to the film thickness and diffusion temperature, suggesting that the ex situ doping optimization should be performed independently. [ABSTRACT FROM AUTHOR]

Nonthermal atmospheric pressure plasma processes, including an interaction between plasma and liquid phases, are employed to induce crosslinked gelatin–graphene oxide composite hydrogels. The properties of thin‐film hydrogel‐forming postplasma treatment are analyzed by infrared spectroscopy, rheology, scanning electron microscope, and in vitro studies. The plasma‐treated hydrogel (PT) exhibits an excellent gel strength with storage modulus up to 341 kPa and thermal stability of gel–sol transition at 65°C, elongated degradation time, and favorable cell viability. The practical application of PT demonstrates an efficient encapsulation and sustainable release of alendronate for at least 21 days. The results show that using nonthermal plasmas can be regarded as an alternative physical method to fabricate composite hydrogels for promising applications in drug carriers and biomedicine. [ABSTRACT FROM AUTHOR]

In January 2020, we identified two severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2)‐infected patients in a familial cluster with one person coming from Wuhan, China. The complete genome sequences of two SARS‐CoV‐2 strains isolated from these patients were identical and 99.98% similar to strains isolated in Wuhan. This is genetically suggestive of human‐to‐human transmission of SARS‐CoV‐2 and indicates Wuhan as the most plausible origin of the early outbreak in Vietnam. The younger patient had a mild upper respiratory illness and a brief viral shedding, whereas the elderly with multi‐morbidity had pneumonia, prolonged viral shedding, and residual lung damage. The evidence of nonsynonymous substitutions in the ORF1ab region of the viral sequence warrants further studies. Highlights: Transmission of SARS‐CoV‐2 is a global public health and clinical concern.This report describes clinical features, virus isolation, and complete genome sequences from the first two SARS‐CoV‐2 infections in Vietnam.Epidemiological and phylogenetic analysis suggested evidence of human‐to‐human transmission of SARS‐CoV‐2. Comparison of SARS‐CoV‐2 strains isolated from these two patients with those from Wuhan showed high similarities.Nonsynonymous substitutions existed in the ORF1ab region of the viral sequence.Compared with mild clinical and virological manifestations in the younger patient, the elderly suffered from pneumonia, prolonged viral shedding, and residual lung damage. [ABSTRACT FROM AUTHOR]

This paper examines the impact of school starting age on teenage marriage and motherhood in Vietnam. The investigation uses data from the 2009 Vietnam Population and Housing Census and regression discontinuity methods to identify the causal effects of school starting age on teenage marriage—a first in the literature—and early motherhood. Results show that girls who start school earlier are more likely to marry and/or give birth as teenagers than their counterparts who begin school later. School starting age impacts are heterogeneous across girl subgroups. The deleterious effects of starting school early are particularly pronounced for teenage girls who are members of ethnic minorities, whose mothers have relatively less education, and whose households are relatively poor. Girls that fall into these subgroups are more likely to benefit from a delay in school entry. Government may wish to adopt a more flexible approach to its age at entry regulations to allow disadvantaged girls the option of starting school later. [ABSTRACT FROM AUTHOR]

The standard‐of‐care for nonmelanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is surgical excision of the tumor. To ensure removal of the entire tumor and minimize removal of healthy tissue, a tool for quick discrimination between cancerous and normal skin is needed. We propose using diffuse reflectance spectroscopy (DRS) to assess tumor margins. We collected two independent clinical datasets. Using a clinical study of 31 patients with 50 NMSC lesions, we trained models including DRS data normalization, a physiological model, parameter selection and logistic regression classifiers. We tested our models on a second clinical dataset of 56 patients with 68 NMSC lesions. Our test results showed the area under the ROC curve of 0.94 for BCC vs normal and 0.90 for SCC vs normal. When applying a threshold selected using the training dataset to the test dataset, for BCC vs normal, specificity is 89% and sensitivity is 87%; for SCC vs normal, specificity is 65% and sensitivity is 97%. This study indicates that DRS can be potentially used to map the tumor margin prior to surgery and monitor margins during the surgery on the surface of the skin. [ABSTRACT FROM AUTHOR]

The standard‐of‐care for nonmelanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is surgical excision of the tumor. To ensure removal of the entire tumor and minimize removal of healthy tissue, a tool for quick discrimination between cancerous and normal skin is needed. We propose using diffuse reflectance spectroscopy (DRS) to assess tumor margins. We collected two independent clinical datasets. Using a clinical study of 31 patients with 50 NMSC lesions, we trained models including DRS data normalization, a physiological model, parameter selection and logistic regression classifiers. We tested our models on a second clinical dataset of 56 patients with 68 NMSC lesions. Our test results showed the area under the ROC curve of 0.94 for BCC vs normal and 0.90 for SCC vs normal. When applying a threshold selected using the training dataset to the test dataset, for BCC vs normal, specificity is 89% and sensitivity is 87%; for SCC vs normal, specificity is 65% and sensitivity is 97%. This study indicates that DRS can be potentially used to map the tumor margin prior to surgery and monitor margins during the surgery on the surface of the skin. [ABSTRACT FROM AUTHOR]

The standard‐of‐care for nonmelanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is surgical excision of the tumor. To ensure removal of the entire tumor and minimize removal of healthy tissue, a tool for quick discrimination between cancerous and normal skin is needed. We propose using diffuse reflectance spectroscopy (DRS) to assess tumor margins. We collected two independent clinical datasets. Using a clinical study of 31 patients with 50 NMSC lesions, we trained models including DRS data normalization, a physiological model, parameter selection and logistic regression classifiers. We tested our models on a second clinical dataset of 56 patients with 68 NMSC lesions. Our test results showed the area under the ROC curve of 0.94 for BCC vs normal and 0.90 for SCC vs normal. When applying a threshold selected using the training dataset to the test dataset, for BCC vs normal, specificity is 89% and sensitivity is 87%; for SCC vs normal, specificity is 65% and sensitivity is 97%. This study indicates that DRS can be potentially used to map the tumor margin prior to surgery and monitor margins during the surgery on the surface of the skin. [ABSTRACT FROM AUTHOR]

Organ-on-a-chip devices that mimic in vivo physiology have the potential to identify effects of chemical and drug exposure in early preclinical stages of drug development while relying less heavily on animal models. We designed a hydrogel rat nerve-on-a-chip (RNoaC) construct that promotes axon growth analogous to mature nerve anatomy and is the first 3D in vitro model to collect electrophysiological and histomorphic metrics to assess in vivo pathophysiology. Here we culture embryonic rat dorsal root ganglia (DRG) in the construct to demonstrate its potential to screen for implications of nerve dysfunction in chemotherapy-induced peripheral neuropathy (CIPN). RNoaC constructs containing DRG explants from E15 rat pups were exposed to the chemotherapeutics bortezomib, oxaliplatin, paclitaxel or vincristine for 7 days. Then, axons were electrically stimulated to collect nerve conduction velocity (NCV) and peak amplitude (AMP), which are clinical electrophysiological metrics indicative of healthy or diseased populations. All chemotherapeutics decreased NCV and AMP in a concentration-dependent manner. At high drug concentrations, NCV and AMP were 10-60% lower than control values. Histopathological analysis revealed hallmarks of peripheral neuropathy. IC50 values calculated from concentration-response curves indicate that the significant decrease in function occurred before a decrease in viability. Our data suggest that electrophysiology recordings collected from our RNoaC platform can closely track subtle pathological changes in nerve function. The ability to collect clinically relevant data from RNoaC suggests it can be an effective tool for in vitro preclinical screening for peripheral neuropathy. [ABSTRACT FROM AUTHOR]

Hydrogenation is a crucial step for improving the efficiency of multicrystalline silicon solar cells. In this work, we investigate the influence of different firing and annealing conditions on the efficacy of bulk hydrogenation in state‐of‐the‐art high‐performance multicrystalline silicon, for a range of hydrogen‐containing dielectric layers. All of the dielectric films studied, including aluminium oxide, amorphous silicon, and silicon nitride deposited with different tools, yield similar bulk lifetimes when annealed at optimal conditions. However, the optimal conditions vary between films, depending on the film properties. The overall hydrogenation effect does not appear to be affected by the cooling rate used during firing or by the application of illuminated annealing, performed at 250 ° C under 8 sun illumination. Moreover, we monitor in situ changes in the recombination behaviour of grain boundaries during the hydrogenation process, using a micro‐photoluminescence spectroscopy system with a temperature controlled stage. It is found that the hydrogenation reaction occurs at the annealing temperature range between 400 ° C and 500 ° C. [ABSTRACT FROM AUTHOR]

Herein, posttreatment techniques of phosphorus‐doped poly‐Si/SiOx passivating contacts, including forming gas annealing (FGA), atomic layer deposition (ALD) of hydrogenated aluminum oxide (AlOx:H), and plasma‐enhanced chemical vapor deposition (PECVD) of hydrogenated silicon nitride (SiNx:H), are investigated and compared in terms of their application to silicon solar cells. A simple FGA posttreatment produces a significant increase in the implied open circuit voltage (iVoc) and the effective minority‐carrier lifetime (τeff) of high‐resistivity crystalline Si (c‐Si) samples, whereas low‐resistivity samples show a minimal change. Treatment by means of AlOx:H and/or SiNx:H followed by postdeposition FGA results in a universal increase in τeff and iVoc for all substrate resistivities (as high as 12.5 ms and 728 mV for 100 Ω cm and 5.4 ms and 727 mV for 2 Ω cm n‐type c‐Si substrates). In addition, both the FGA and AlOx:H + FGA techniques can inject sufficient hydrogen into the samples to passivate defects at the SiOx/c‐Si and poly‐Si/SiOx interfaces. However, this hydrogen concentration is insufficient to neutralize both the nonradiative defects inside the poly‐Si films and dangling bonds associated with the amorphous Si phase present in them. The hydrogen injected by the SiNx:H + FGA technique can passivate both the interfaces and the defects and dangling bonds within the poly‐Si film. These results are confirmed by low‐temperature photoluminescence spectroscopy, Fourier transform infrared spectroscopy, and dynamic secondary‐ion mass spectrometry measurements. [ABSTRACT FROM AUTHOR]