Publications by authors named "N W Schipper"

All-perovskite tandem photovoltaics are a potentially cost-effective technology to power chemical fuel production, such as green hydrogen. However, their application is limited by deficits in open-circuit voltage and, more challengingly, poor operational stability of the photovoltaic cell. Here we report a laboratory-scale solar-assisted water-splitting system using an electrochemical flow cell and an all-perovskite tandem solar cell.

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Multijunction photovoltaics (PVs) are gaining prominence owing to their superior capability of achieving power conversion efficiencies (PCEs) beyond the radiative limit of single-junction cells, where improving narrow bandgap tin-lead perovskites is critical for thin-film devices. With a focus on understanding the chemistry of tin-lead perovskite precursor solutions, we herein find that Sn(II) species dominate interactions with precursors and additives and uncover the exclusive role of carboxylic acid in regulating solution colloidal properties and film crystallisation, and ammonium in improving film optoelectronic properties. Materials that combine these two function groups, amino acid salts, considerably improve the semiconducting quality and homogeneity of perovskite films, surpassing the effect of the individual functional groups when introduced as part of separate molecules.

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ZNRF3, a negative regulator of β-catenin signaling, removes Wnt receptors from the membrane. Currently, it is unknown which tumor-associated variants can be considered driver mutations and through which mechanisms they contribute to cancer. Here we show that all truncating mutations analyzed at endogenous levels exhibit loss-of-function, with longer variants retaining partial activity.

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Retinitis pigmentosa (RP) is a form of retinal degeneration affecting a young population with an unmet medical need. Photoreceptor degeneration has been associated with increased guanosine 3',5'-cyclic monophosphate (cGMP), which reaches toxic levels for photoreceptors. Therefore, inhibitory cGMP analogues attract interest for RP treatments.

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In contribution to the pharmaceutical development of cyclic guanosine monophosphorothioate analogue cGMPSA as a potential active pharmaceutical ingredient (API) for the treatment of inherited retinal degenerations (IRDs), its neutral form (cGMPSA-H) and salts of sodium (-Na), calcium (-Ca), ammonium (-NH ), triethylammonium (-TEA), tris(hydroxymethyl)aminomethane (-Tris), benethamine (-Bnet), and benzathine (-BZ) were prepared. Their solid-state properties were studied with differential scanning calorimetry, thermogravimetric analysis, hot-stage microscopy, and dynamic vapor sorption, and their solubilities were measured in deionized H O as well as aqueous HCl and NaOH buffers. A total of 21 crystal modifications of cGMPSA were found and characterized by X-ray powder diffraction.

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