Catálogo de publicaciones - revistas

<jats:p> Highlights from the <jats:italic>Science</jats:italic> family of journals </jats:p>

<jats:p>Editors’ selections from the current scientific literature</jats:p>

<jats:p>Nipah virus (NiV) and Hendra virus (HeV) are zoonotic henipaviruses (HNVs) responsible for outbreaks of encephalitis and respiratory illness. The entry of HNVs into host cells requires the attachment (G) and fusion (F) glycoproteins, which are the main targets of antibody responses. To understand viral infection and host immunity, we determined a cryo–electron microscopy structure of the NiV G homotetrameric ectodomain in complex with the nAH1.3 broadly neutralizing antibody Fab fragment. We show that a cocktail of two nonoverlapping G-specific antibodies neutralizes NiV and HeV synergistically and limits the emergence of escape mutants. Analysis of polyclonal serum antibody responses elicited by vaccination of macaques with NiV G indicates that the receptor binding head domain is immunodominant. These results pave the way for implementing multipronged therapeutic strategies against these deadly pathogens.</jats:p>

<jats:p>Information flow in neurons proceeds by integrating inputs in dendrites, generating action potentials near the soma, and releasing neurotransmitters from nerve terminals in the axon. We found that in the striatum, acetylcholine-releasing neurons induce action potential firing in distal dopamine axons. Spontaneous activity of cholinergic neurons produced dopamine release that extended beyond acetylcholine-signaling domains, and traveling action potentials were readily recorded from dopamine axons in response to cholinergic activation. In freely moving mice, dopamine and acetylcholine covaried with movement direction. Local inhibition of nicotinic acetylcholine receptors impaired dopamine dynamics and affected movement. Our findings uncover an endogenous mechanism for action potential initiation independent of somatodendritic integration and establish that this mechanism segregates the control of dopamine signaling between axons and somata.</jats:p>

<jats:p> Thermoelectric materials allow for direct conversion between heat and electricity, offering the potential for power generation. The average dimensionless figure of merit <jats:italic>ZT</jats:italic> <jats:sub>ave</jats:sub> determines device efficiency. N-type tin selenide crystals exhibit outstanding three-dimensional charge and two-dimensional phonon transport along the out-of-plane direction, contributing to a high maximum figure of merit <jats:italic>Z</jats:italic> <jats:sub>max</jats:sub> of ~3.6 × 10 <jats:sup>−3</jats:sup> per kelvin but a moderate <jats:italic>ZT</jats:italic> <jats:sub>ave</jats:sub> of ~1.1. We found an attractive high <jats:italic>Z</jats:italic> <jats:sub>max</jats:sub> of ~4.1 × 10 <jats:sup>−3</jats:sup> per kelvin at 748 kelvin and a <jats:italic>ZT</jats:italic> <jats:sub>ave</jats:sub> of ~1.7 at 300 to 773 kelvin in chlorine-doped and lead-alloyed tin selenide crystals by phonon-electron decoupling. The chlorine-induced low deformation potential improved the carrier mobility. The lead-induced mass and strain fluctuations reduced the lattice thermal conductivity. Phonon-electron decoupling plays a critical role to achieve high-performance thermoelectrics. </jats:p>

<jats:p>Membranes have the potential to substantially reduce energy consumption of industrial chemical separations, but their implementation has been limited owing to a performance upper bound—the trade-off between permeability and selectivity. Although recent developments of highly permeable polymer membranes have advanced the upper bounds for various gas pairs, these polymers typically exhibit limited selectivity. We report a class of hydrocarbon ladder polymers that can achieve both high selectivity and high permeability in membrane separations for many industrially relevant gas mixtures. Additionally, their corresponding films exhibit desirable mechanical and thermal properties. Tuning of the ladder polymer backbone configuration was found to have a profound effect on separation performance and aging behavior.</jats:p>

<jats:p> The diagonal relationship in the periodic table between phosphorus and carbon has set an expectation that the triple-bonded diatomic diphosphorus molecule (P <jats:sub>2</jats:sub> ) should more closely mimic the attributes of acetylene (HC≡CH) rather than its group 15 congener dinitrogen (N <jats:sub>2</jats:sub> ). Although acetylene has well-documented coordination chemistry with mononuclear transition metals, coordination complexes that feature P <jats:sub>2</jats:sub> bound to a single metal center have remained elusive. We report the isolation and x-ray crystallographic characterization of a mononuclear iron complex featuring P <jats:sub>2</jats:sub> coordination in a side-on, η <jats:sup>2</jats:sup> -binding mode. An analogous η <jats:sup>2</jats:sup> -bound bis-timethylsilylacetylene iron complex is reported for comparison. Nuclear magnetic resonance, infrared, and Mössbauer spectroscopic analysis—in conjunction with density functional theory calculations—demonstrate that η <jats:sup>2</jats:sup> -P <jats:sub>2</jats:sub> and η <jats:sup>2</jats:sup> -acetylene ligands exert a similar electronic demand on mononuclear iron centers but exhibit different reactivity profiles. </jats:p>

<jats:p> Berry curvature is analogous to magnetic field but in momentum space and is commonly present in materials with nontrivial quantum geometry. It endows Bloch electrons with transverse anomalous velocities to produce Hall-like currents even in the absence of a magnetic field. We report the direct observation of in situ tunable valley-selective Hall effect (VSHE), where inversion symmetry, and thus the geometric phase of electrons, is controllable by an out-of-plane electric field. We use high-quality bilayer graphene with an intrinsic and tunable bandgap, illuminated by circularly polarized midinfrared light, and confirm that the observed Hall voltage arises from an optically induced valley population. Compared with molybdenum disulfide (MoS <jats:sub>2</jats:sub> ), we find orders of magnitude larger VSHE, attributed to the inverse scaling of the Berry curvature with bandgap. By monitoring the valley-selective Hall conductivity, we study the Berry curvature’s evolution with bandgap. This in situ manipulation of VSHE paves the way for topological and quantum geometric optoelectronic devices, such as more robust switches and detectors. </jats:p>

<jats:p>The compressibility of a medium, quantifying its response to mechanical perturbations, is a fundamental property determined by the equation of state. For gases of material particles, studies of the mechanical response are well established, in fields from classical thermodynamics to cold atomic quantum gases. We demonstrate a measurement of the compressibility of a two-dimensional quantum gas of light in a box potential and obtain the equation of state for the optical medium. The experiment was carried out in a nanostructured dye-filled optical microcavity. We observed signatures of Bose-Einstein condensation at high phase-space densities in the finite-size system. Upon entering the quantum degenerate regime, the measured density response to an external force sharply increases, hinting at the peculiar prediction of an infinite compressibility of the deeply degenerate Bose gas.</jats:p>

<jats:p>The unprecedented rise in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections during December 2021 was concurrent with rapid spread of the Omicron variant in England and globally. We analyzed the prevalence of SARS-CoV-2 and its dynamics in England from the end of November to mid-December 2021 among almost 100,000 participants in the REACT-1 study. Prevalence was high with rapid growth nationally and particularly in London during December 2021, with an increasing proportion of infections due to Omicron. We observed large decreases in swab positivity among mostly vaccinated older children (12 to 17 years) relative to unvaccinated younger children (5 to 11 years), and in adults who received a third (booster) vaccine dose versus two doses. Our results reinforce the importance of vaccination and booster campaigns, although additional measures have been needed to control the rapid growth of the Omicron variant.</jats:p>