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Producing hydrogen (H2) by splitting water with fossil-free electricity is considered a grand challenge for developing sustainable energy systems and a carbon dioxide free source of renewable H2. Renewable H2 may be produced from water by electrolysis with either low efficiency alkaline electrolyzers that suffer 50–65% losses, or by more efficient acidic electrolyzers with rare platinum group metal catalysts (Pt). Consequently, research has focused on developing alternative, cheap, and robust catalysts made from earth-abundant elements. Here, we show that crystalline Ni5P4 evolves H2 with geometric electrical to chemical conversion efficiency on par with Pt in strong acid (33 mV dec−1 Tafel slope and −62 mV overpotential at −100 mA cm−2 in 1 M H2SO4). The conductivity of Ni5P4 microparticles is sufficient to allow fabrication of electrodes without conducting binders by pressing pellets. Significantly, no catalyst degradation is seen in short term studies at current densities of −10 mA cm−2, equivalent to ∼10% solar photoelectrical conversion efficiency. The realization of a noble metal-free catalyst performing on par with Pt in both strong acid and base offers a key step towards industrially relevant electrolyzers competing with conventional H2 sources.

The magnetoelectric coupling, a phenomenon inducing magnetic (electric) polarization by application of an external electric (magnetic) field and first conjectured by Curie in 1894, is observed in most of the multiferroics and used for many applications in various fields such as data storage or sensing. However, its microscopic origin is a long-standing controversy in the scientific community. An intense revival of interest developed in the beginning of the 21st century due to the emergence of multiferroic frustrated magnets in which the ferroelectricity is magnetically induced and which present an inherent strong magnetoelectric coupling. The Dzyaloshinskii-Moriya interaction (DMI) well accounts for such ferroelectricity in systems with a noncollinear magnetic order such as the ${\mathrm{RMnO}}_{3}$ manganites. The DMI effect is, however, inadequate for systems presenting ferroelectricity induced by quasicollinear spin arrangements such as the prominent ${\mathrm{RMn}}_{2}{\mathrm{O}}_{5}$ manganites. Among different microscopic mechanisms proposed to resolve this incompatibility, the exchange-striction model stands as the most invoked candidate. In this scenario, the polar atomic displacements originate from the release of a frustration caused by the magnetic order. Despite its theoretical description 15 years ago, this mechanism had yet to be unambiguously validated experimentally. The breakthrough finally comes from ${\mathrm{SmMn}}_{2}{\mathrm{O}}_{5}$ presenting a unique magnetic order revealed by powder neutron diffraction. The unique orientation of its magnetic moment establishes the missing element that definitely validates the exchange striction as the effective mechanism for the spin-induced ferroelectricity in this series. More generally, this is a proof of concept that validates this model on actual systems, facilitating the development of a new generation of multiferroics with unrivaled magnetoelectric properties.

Using a combination of x-ray absorption spectroscopy (XAS) experiments and first-principles calculations, we demonstrate that insulating ${\mathrm{KCuO}}_{2}$ contains Cu in an unusually high formal 3+ valence state, and the ligand-to-metal (O-to-Cu) charge-transfer energy is intriguingly negative ($\mathrm{\ensuremath{\Delta}}\ensuremath{\sim}\ensuremath{-}1.5$ eV) and has a dominant ($\ensuremath{\sim}60%$) ligand-hole character in the ground state akin to the high ${T}_{c}$ cuprate Zhang-Rice state. Unlike most other formal ${\mathrm{Cu}}^{3+}$ compounds, the Cu $2p$ XAS spectra of ${\mathrm{KCuO}}_{2}$ exhibit pronounced $3{d}^{8}$ (${\mathrm{Cu}}^{3+}$) multiplet structures, which account for $\ensuremath{\sim}40%$ of its ground state wave function. Ab initio calculations elucidate the origin of the band gap in ${\mathrm{KCuO}}_{2}$ as arising primarily from strong intracluster Cu $3d$-O $2p$ hybridizations (${t}_{\mathrm{pd}}$); the value of the band gap decreases with a reduced value of ${t}_{\mathrm{pd}}$. Further, unlike conventional negative-charge-transfer insulators, the band gap in ${\mathrm{KCuO}}_{2}$ persists even for vanishing values of Coulomb repulsion $U$, underscoring the importance of single-particle band-structure effects connected to the one-dimensional nature of the compound.

Possible interaction of the serotonergic system with intracellular calcium mechanisms was investigated using techniques of ratio imaging measurement of intracellular Ca2+ and confocal microscopy in cleaving embryos of sea urchin Lytechinus pictus. Some serotonin antagonists specifically increase free intracellular Ca2+ and evoke transient regression of the first cleavage furrow, suggesting possible linkage of serotonergic and calcium mechanisms in the regulation of cellular events during cleavage divisions. These effects were more pronounced in the experiments with hydrophilic 5-HT-antagonists, quarternary ammonium salts that do not penetrate the cell membrane. Thus, it appears that 5-HT-receptors which mediate these effects are localised on the cell membrane, whereas previously studied receptors mediating the cytostatic action of lipophilic 5-HT-antagonists are localised intracellularly.

Approximately 5% of all primary care consultations in the UK are for upper gastrointestinal (GI) diseases, the most common of which is dyspepsia, with a prevalence of between 25 and 50% in the western world. The exact definition of dyspepsia is elusive, which has resulted in confusion about diagnosis and treatment, highlighting the need for management guidelines. The International Gastro Primary Care Groups (IGPCG) has developed, by consensus, practical guidelines to help GPs manage patients with upper GI symptoms. After a detailed history is taken, alarm symptoms identified and organic disease excluded, the predominant symptom should be identified. This strategy, as outlined in the IGPCG upper GI disease management plan, can help the GP in the selection of the most appropriate treatment for each patient. This plan is flexible enough to be used in a wide variety of healthcare systems and will evolve as new evidence becomes available.

The DWPF must meet Waste Acceptance Preliminary Specifications (WAPS) for acceptance of the DWPF canistered waste forms. A number of these specifications deal with the exclusion of non-wasteglass (or foreign) materials within the canistered waste forms. Those material which are specifically excluded include the following: Free Liquids, Free Gases, other than cover or radiogenic gases, Explosives, Pyrophorics and Combustibles, and Organics. This report documents the results obtained by carrying out an assigned task as described in three task plans. The task plans cover the determination of pressure, gas composition and relative humidity of SRL canistered waste forms; and organic and inorganic analysis of volatilized and condensed species within SRL canistered waste forms. These results provide evidence to demonstrate compliance with these specifications and will be included in the Waste Form Qualification Report (WQR). In all, four canistered waste forms, produced during the Scale Glass Melter (SGM) campaigns, were examined. The internal gas pressure, dewpoint temperature and gas composition were determined for each canistered waste form. The experience gained in these experiments will be used to generate procedures for obtaining the same information on canistered waste forms produced during the Integrated Cold Runs (ICR). 10 refs., 2 figs., 1 tab.

The activation of the sea-urchin egg at fertilization is triggered by two ionic changes in the egg cytoplasm. First there is a wave of increase in cytoplasmic free calcium concentration (Ca2+i) that travels across the egg within the first minute of fertilization. The calcium wave is followed by a sustained rise in intracellular pH (pHi). Fertilizing spermatozoa cause these two ionic changes by stimulating the hydrolysis of phosphatidylinositol 1,4,5-bisphosphate (PtdInsP2). PtdInsP2 hydrolysis produces inositol 1,4,5-trisphosphate, which releases calcium from intracellular stores, and diacylglycerol, which stimulates a plasma membrane sodium/hydrogen antiporter causing the rise in pHi. A positive feedback cycle of intracellular calcium release and InsP3 production appears to be part of the mechanism by which the calcium wave is propagated. It has been suggested that the spermatozoon triggers the calcium wave by acting on a cell surface receptor that couples to the egg phosphoinositidase C via a G-protein. We discuss evidence for an alternative hypothesis of egg activation in which a spermatozoon triggers the calcium wave by introducing a soluble activating factor into the egg cytoplasm.

Summary Two patients are described who developed a gastric fistula to the anterior abdominal wall following anterior gastropexy. Both fistulae closed spontaneously without any specific treatment. It is suggested that the fixation of the stomach to the anterior abdominal wall allows the fistula to discharge externally thus preventing peritoneal contamination with its serious consequences.