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Perovskite solar cells (PSCs) offer an efficient, inexpensive alternative to current photovoltaic technologies, with the potential for manufacture via high-throughput coating methods. However, challenges for commercial-scale solution-processing of metal-halide perovskites include the use of harmful solvents, the expense of maintaining controlled atmospheric conditions, and the inherent instabilities of PSCs under operation. Here, we address these challenges by introducing a high volatility, low toxicity, biorenewable solvent system to fabricate a range of 2D perovskites, which we use as highly effective precursor phases for subsequent transformation to α-formamidinium lead triiodide (α-FAPbI 3 ), fully processed under ambient conditions. PSCs utilising our α-FAPbI 3 reproducibly show remarkable stability under illumination and elevated temperature (ISOS-L-2) and “damp heat” (ISOS-D-3) stressing, surpassing other state-of-the-art perovskite compositions. We determine that this enhancement is a consequence of the 2D precursor phase crystallisation route, which simultaneously avoids retention of residual low-volatility solvents (such as DMF and DMSO) and reduces the rate of degradation of FA + in the material. Our findings highlight both the critical role of the initial crystallisation process in determining the operational stability of perovskite materials, and that neat FA + -based perovskites can be competitively stable despite the inherent metastability of the α-phase. The use of harmful solvents to fabricate stable devices hampers the commercialization of perovskite solar cells. Here, the authors introduce a biorenewable solvent system and precursor-phase engineering to realize stable formamidinium lead triiodide-based solar cells.

The stability of hybrid organic–inorganic halide perovskite semiconductors remains a significant obstacle to their application in photovoltaics. To this end, the use of low‐dimensional (LD) perovskites, which incorporate hydrophobic organic moieties, provides an effective strategy to improve their stability, yet often at the expense of their performance. To address this limitation, supramolecular engineering of noncovalent interactions between organic and inorganic components has shown potential by relying on hydrogen bonding and conventional van der Waals interactions. Here, the capacity to access novel LD perovskite structures that uniquely assemble through unorthodox S‐mediated interactions is explored by incorporating benzothiadiazole‐based moieties. The formation of S‐mediated LD structures is demonstrated, including one‐dimensional (1D) and layered two‐dimensional (2D) perovskite phases assembled via chalcogen bonding and S–π interactions. This involved a combination of techniques, such as single crystal and thin film X‐ray diffraction, as well as solid‐state NMR spectroscopy, complemented by molecular dynamics simulations, density functional theory calculations, and optoelectronic characterization, revealing superior conductivities of S‐mediated LD perovskites. The resulting materials are applied in n‐i‐p and p‐i‐n perovskite solar cells, demonstrating enhancements in performance and operational stability that reveal a versatile supramolecular strategy in photovoltaics. A new generation of low‐dimensional hybrid halide perovskite materials assembled via chalcogen bonding and S–π interactions is demonstrated by a combination of techniques, including X‐ray diffraction and solid‐state nuclear magnetic resonance spectroscopy, complemented by molecular dynamics simulations, density functional theory calculations, and optoelectronic characterization, revealing superior conductivities and enhancements in performance and operational stabilities in perovskite solar cells.

Resting membrane potential (RMP) and intracellular [Ca.sup.2+] concentration [[([Ca.sup.2+]).sub.i]] are involved in tumorigenesis and metastasis. The present study investigated whether functional cardiac [Na.sup.+] channels are expressed in human melanoma cells (WM 266-4) and its nonmalignant human melanocytes (HMC), as well as whether they participate in RMP maintenance and [Ca.sup.2+] homeostasis. Confocal microscopy and western blot analysis were used to detect [Na.sup.+] channels. The patch-clamp technique was employed to record [Na.sup.+] currents and action potentials. Cytoplasmic [Ca.sup.2+] was measured by loading Fluo-4. Cardiac ([Na.sup.v]1.5) [Na.sup.+] channels were expressed in HMCs and WM 266-4 cells. Tetrodotoxin (TTX) dose-dependently blocked [Na.sup.+] currents in WM 266-4 while HMCs had no [Na.sup.+] currents. Ultraviolet light induced similar action potentials in HMCs and WM 266-4 cells, which were abolished by transient receptor potential A1 channel-specific blocker, HC-030031. Compared with HMCs, RMP was substantially depolarized in WM 266-4. TTX hyperpolarized RMP in WM 266-4 cells at a concentration of 30 [micro]M, which facilitated [Ca.sup.2+] influx. Compared with HMCs, [([Ca.sup.2+]).sub.i] was significantly higher in WM 266-4 cells and was elevated by 30 [micro]M TTX. Collectively, Cardiac [Na.sup.+] channels depolarize RMP and inhibit [Ca.sup.2+] uptake in melanoma cells possibly contributing to tumorigenesis and metastasis. [Na.sup.+] channel agonists may be developed to treat melanoma such as WM 266-4.

Resting membrane potential (RMP) and intracellular Ca2+ concentration [(Ca2+)i] are involved in tumorigenesis and metastasis. The present study investigated whether functional cardiac Na+ channels are expressed in human melanoma cells (WM 266-4) and its nonmalignant human melanocytes (HMC), as well as whether they participate in RMP maintenance and Ca2+ homeostasis. Confocal microscopy and western blot analysis were used to detect Na+ channels. The patch-clamp technique was employed to record Na+ currents and action potentials. Cytoplasmic Ca2+ was measured by loading Fluo-4. Cardiac (Nav1.5) Na+ channels were expressed in HMCs and WM 266-4 cells. Tetrodotoxin (TTX) dose-dependently blocked Na+ currents in WM 266-4 while HMCs had no Na+ currents. Ultraviolet light induced similar action potentials in HMCs and WM 266-4 cells, which were abolished by transient receptor potential A1 channel-specific blocker, HC-030031. Compared with HMCs, RMP was substantially depolarized in WM 266-4. TTX hyperpolarized RMP in WM 266-4 cells at a concentration of 30 µM, which facilitated Ca2+ influx. Compared with HMCs, (Ca2+)i was significantly higher in WM 266-4 cells and was elevated by 30 µM TTX. Collectively, Cardiac Na+ channels depolarize RMP and inhibit Ca2+ uptake in melanoma cells possibly contributing to tumorigenesis and metastasis. Na+ channel agonists may be developed to treat melanoma such as WM 266-4.

FAPbI\\(_3\\) is a material of interest for its potential in solar cell applications, driven by its remarkable optoelectronic properties. However, the low-temperature phase of FAPbI\\(_3\\) remains poorly understood, with open questions surrounding its crystal structure, octahedral tilting, and the arrangement of formamidinium (FA) cations. Using our trained machine-learned potential in combination with large-scale molecular dynamics simulations, we provide a detailed investigation of this phase, uncovering its structural characteristics and dynamical behavior. Our analysis reveals the octahedral tilt pattern and sheds light on the rotational dynamics of FA cations in the low temperature phase. Strikingly, we find that the FA cations become frozen in a metastable configuration, unable to reach the thermodynamic ground state. By comparing our simulated results with experimental nuclear magnetic resonance (NMR) and inelastic neutron scattering (INS) spectra, we demonstrate good agreement, further validating our findings. This phenomenon mirrors experimental observations and offers a compelling explanation for the experimental challenges in accessing the true ground state. These findings provide critical insights into the fundamental physics of FAPbI\\(_3\\) and its low-temperature behavior, advancing our understanding of this technologically important material.

Perovskite solar cells (PSCs) offer an efficient, inexpensive alternative to current photovoltaic technologies, with the potential for manufacture via high-throughput coating methods. However, challenges for commercial-scale solution-processing of metal-halide perovskites include the use of harmful solvents, the expense of maintaining controlled atmospheric conditions, and the inherent instabilities of PSCs under operation. Here, we address these challenges by introducing a high volatility, low toxicity, biorenewable solvent system to fabricate a range of 2D perovskites, which highly effective precursor phases for subsequent transformation to alpha-formamidinium lead triiodide (FAPbI3), fully processed under ambient conditions. PSCs utilising our FAPbI3 reproducibly show remarkable stability under illumination and elevated temperature (ISOS-L-2) and \"damp heat\" (ISOS-D-3) stressing, surpassing other state-of-the-art perovskite compositions. We determine that this enhancement is a consequence of the 2D precursor phase crystallisation route, which simultaneously avoids retention of residual low-volatility solvents (such as DMF and DMSO) and reduces the rate of degradation of FA+ in the material. Our findings highlight both the critical role of the initial crystallisation process in determining the operational stability of perovskite materials, and that neat FA+-based perovskites can be competitively stable despite the inherent metastability of the alpha-phase.

We show that adding ethylenediamine (EDA) to perovskite precursor solution improves the photovoltaic device performance and material stability of high-bromide-content, methylammonium-free, formamidinium cesium lead halide perovskites FA1-xCsxPb(I1-yBry)3 which are currently of interest for perovskite-on-Si tandem solar cells. Using spectroscopy and hyperspectral microscopy, we show that the additive improves film homogeneity and suppresses the phase instability that is ubiquitous in high-Br perovskite formulations, producing films that remain stable for over 100 days in ambient conditions. With the addition of 1 mol% EDA we demonstrate 1.69 eV-gap perovskite single-junction p-i-n devices with a VOC of 1.22 V, and a champion maximum power point tracked power conversion efficiency of 18.8%, comparable to the best reported methylammonium-free perovskites. Using nuclear magnetic resonance (NMR) spectroscopy and X-ray diffraction techniques, we show that EDA reacts with FA+ in solution, rapidly and quantitatively forming imidazolinium cations. It is the presence of imidazolinium during crystallization which drives the improved perovskite thin-film properties.

I have heard so much negativity from Canadian fans complaining about not winning medals at the games this year.

Sepsis is a life-threatening condition caused by an inappropriate host response to an infection that can lead to multi-organ failure and death. Predictive markers that can inform the trajectory and outcome for a septic patient are necessary to inform treatment and increase the likelihood for patient survival. Here, by leveraging the concept of Lethal Dose 50 (LD50), which is the dose of a pathogen that will kill 50% of a genetically identical host population, we tested the hypothesis that variations in brain structure can be readily used to predict trajectory and outcome in a murine model of sepsis. We found that one week prior to infection, mice that were fated to survive exhibited greater cortical volume, solidity, and thickness compared to those who would succumb to the LD50 challenge, and these metrics were sufficient to train multiple predictive models with 75% to 94% accuracy. Our work reveals a readily measurable non-genetic marker for predicting sepsis prognosis in mice and demonstrates the potential for using pre-infection high-resolution structural brain scans to predict infection outcomes in humans.

Accelerated warming and hiatus periods in the long-term rise of Global Mean Surface Temperature (GMST) have, in recent decades, been associated with the Interdecadal Pacific Oscillation (IPO). Critically, decadal climate prediction relies on the skill of state-of-the-art climate models to reliably represent these low-frequency climate variations. We undertake a systematic evaluation of the simulation of the IPO in the suite of Coupled Model Intercomparison Project 5 (CMIP5) models. We track the IPO in pre-industrial (control) and all-forcings (historical) experiments using the IPO tripole index (TPI). The TPI is explicitly aligned with the observed spatial pattern of the IPO, and circumvents assumptions about the nature of global warming. We find that many models underestimate the ratio of decadal-to-total variance in sea surface temperatures (SSTs). However, the basin-wide spatial pattern of positive and negative phases of the IPO are simulated reasonably well, with spatial pattern correlation coefficients between observations and models spanning the range 0.4-0.8. Deficiencies are mainly in the extratropical Pacific. Models that better capture the spatial pattern of the IPO also tend to more realistically simulate the ratio of decadal to total variance. Of the 13% of model centuries that have a fractional bias in the decadal-to-total TPI variance of 0.2 or less, 84% also have a spatial pattern correlation coefficient with the observed pattern exceeding 0.5. This result is highly consistent across both IPO positive and negative phases. This is evidence that the IPO is related to one or more inherent dynamical mechanisms of the climate system.