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Multivalent S2 subunit vaccines provide broad protection against Clade 1 sarbecoviruses in female mice

Photoluminescence, energy transfer, and quantum yield studies of CaF2:Tb3+–Ce3+: Latent fingerprints and anticounterfeit applications

Ce3+ co-doped CaF2: Tb3+ nanoparticles were synthesized by a hydrothermal method using l-glutamic acid as a capping agent. When the concentration of a Ce3+ ion increases, peak broadening in the X-ray Diffraction (XRD) pattern takes place, indicating strain developed in a lattice. The XRD pattern shows no extra peak for Ce3+ ions up to 13 at. % co-doped in CaF2:5 at. % Tb3+. However, Transmission Electron Microscopy (TEM) analysis shows an extra phase of an LnF3 hexagonal phase at even lower concentrations (<13 at. %). This is due to the charge imbalance between Ce3+ and Ca2+. Two main emission peaks at 488 and 541 nm of Tb3+ are observed through direct (377 nm) and indirect excitations (302 nm). Enhancement in the luminescence intensity of Tb3+ emission is observed when Ce3+ is incorporated in CaF2: Tb3+. This corresponds to the efficient energy transfer from Ce3+ to Tb3+. Under the excitation of 302 nm, the energy transfer efficiency reaches up to 86%. The decay lifetime of Ce3+ for Tb3+ co-doping with CaF2:5 at. % Ce3+ decreases from 24 to 11 ns with the increase of Tb3+ concentration (0–5 at. %), indicating energy transfer from Ce3+ to Tb3+. The main interaction(s) of energy transfer is observed through a dipole–dipole interaction. The maximum quantum yield value for 2 at. % Tb3+ co-doped CaF2:5 at. % Ce3+ of ∼49% is observed. Energy transfer is confirmed by calculated radiative and non-radiative decay rate constants.

Formulation development and evaluation, in silico PBPK modeling and in vivo pharmacodynamic studies of clozapine matrix type transdermal patches

Activity of the mammalian DNA transposon piggyBat from Myotis lucifugus is restricted by its own transposon ends

AbstractMembers of the piggyBac superfamily of DNA transposons are widely distributed in host genomes ranging from insects to mammals. The human genome has retained five piggyBac-derived genes as domesticated elements although they are no longer mobile. Here, we have investigated the transposition properties of piggyBat from Myotis lucifugus, the only known active mammalian DNA transposon, and show that its low activity in human cells is due to subterminal inhibitory DNA sequences. Activity can be dramatically improved by their removal, suggesting the existence of a mechanism for the suppression of transposon activity. The cryo-electron microscopy structure of the piggyBat transposase pre-synaptic complex showed an unexpected mode of DNA binding and recognition using C-terminal domains that are topologically different from those of the piggyBac transposase. Here we show that structure-based rational re-engineering of the transposase through the removal of putative phosphorylation sites and a changed domain organization - in combination with truncated transposon ends - results in a transposition system that is at least 100-fold more active than wild-type piggyBat.

Non-ionizing cross section of electron scattering on atoms in matter accounting for dynamical screening effect

We present a model of non-ionizing scattering of electrons on atomic ensemble in matter, applicable in a wide electron energy range from ∼eV up to relativistic ones. The approach based on the dynamic-structure factor formalism considers collective response of the atomic and electronic systems of a target. It accounts for dynamical screening of atomic nuclei in matter by valence (collective) and core–shell electrons during the scattering events, dependent on the incident electron velocity. The proposed formalism for the cross section enables us to describe in a unified manner the electron scattering on the ensemble of isolated atomic nuclei at high incident electron energies, reducing to the scattering on phonons with a decrease in the energy. Our model can be used, e.g., in transport Monte Carlo codes to describe the energy exchange between excited electrons and atomic ensemble in matter. An example of swift heavy ion track formation in quartz simulated with the proposed cross section shows reasonable agreement with the experiment validating the model.

Regulation of fibronectin and collagens type I, III and VI by TNF-α, TGF-β, IL-13, and tofacitinib

DNA targeting by compact Cas9d and its resurrected ancestor

AbstractType II CRISPR endonucleases are widely used programmable genome editing tools. Recently, CRISPR-Cas systems with highly compact nucleases have been discovered, including Cas9d (a type II-D nuclease). Here, we report the cryo-EM structures of a Cas9d nuclease (747 amino acids in length) in multiple functional states, revealing a stepwise process of DNA targeting involving a conformational switch in a REC2 domain insertion. Our structures provide insights into the intricately folded guide RNA which acts as a structural scaffold to anchor small, flexible protein domains for DNA recognition. The sgRNA can be truncated by up to ~25% yet still retain activity in vivo. Using ancestral sequence reconstruction, we generated compact nucleases capable of efficient genome editing in mammalian cells. Collectively, our results provide mechanistic insights into the evolution and DNA targeting of diverse type II CRISPR-Cas systems, providing a blueprint for future re-engineering of minimal RNA-guided DNA endonucleases.

Laser-wavelength dependence of ultrafast demagnetization in ferromagnetic metals

Laser-induced ultrafast demagnetization (UD) in ferromagnetic metals opens a new frontier at the intersection between laser technology and materials sciences. However, a complete understanding is still missing even in simple 3d metals. Prior studies have often concentrated on the effect of laser fluence on UD, but whether and how the wavelength affects UD remain under explored. Here, we propose a new perspective that is based on laser wavelength. We show, via the example of fcc Ni, that without intraband transitions, wavelength has a significant impact on UD but the spin moment reduction is small. With the intraband transition, UD weakly depends on wavelength, but with a large spin reduction. The time-resolved electron and spin density of states reveals that electrons around the Fermi energy are largely responsible for strong demagnetization, which almost wipes out the imprint of the photon energy on demagnetization, explaining the experimental observation. A significant spin reduction is found when a large portion of the unoccupied minority states slightly above the Fermi level becomes occupied.

Individual differences in temporal order judgment

Acceptor engineering of quinone-based cycloparaphenylenes via post-synthesis for achieving white-light emission in single-molecule

Twinning and strain induced modifications in insulator-metal transition and large magnetoresistance in La0.67Ca0.33MnO3 films

The physical characteristics of epitaxially sputtered La0.67Ca0.33MnO3 (LCMO) films are modified by twinning when deposited on different single crystal substrates at varying thicknesses. Comprehensive high-resolution x-ray diffraction measurements reveal the formation of two types of tilted domains, whose influence becomes prominent in rocking curve scans with increasing thickness. The occurrence of twinning is attributed to the shear strain relaxation process that accommodates the lattice symmetry mismatch between the film and the substrate. In the electrical transport properties of thicker films, the effect of twinning manifests as a broadening of the insulator–metal transition in resistance–temperature (R–T) plots, in which an extra hump emerges. This broadening effect is also noticeable in magnetoresistance curves, leading to a large magnetoresistance spread over a broad temperature range. While the additional hump in R–T plots vanishes under stronger magnetic fields, the persistent broadening of the transition and magnetoresistance suggests that twinning continues to influence the film properties even at higher field strengths. Thick LCMO films exhibit similar broadening in the transition from the paramagnetic to ferromagnetic phase with an additional transition during magnetic (M–T) measurements. In contrast, LCMO films of lesser thickness display sharp electrical and magnetic transitions without significant evidence of any supplementary transition. These results suggest that the twinning effect in films, caused by substrate-induced strain relaxation, can profoundly alter the transport properties of these functional films and substantially widen the temperature range where maximum magnetoresistance is observed.

RETRACTED ARTICLE: A fixed support method for cryogenic silicon cavities of ultra-stable lasers for space applications

Author Correction: An intein-split transactivator for intersectional neural imaging and optogenetic manipulation

First-principles assisted design of high-entropy thermoelectric materials based on half-Heusler alloys

The deformation potential theory and semi-classical Boltzmann theory were combined to predict the thermoelectric performances of half-Heusler NaCuTe alloy and Li0.5Na0.5CuSe0.5Te0.5 high-entropy half-Heusler alloy through first-principles calculations. The former was constructed via the congener substitution method from LiCuSe alloy, while the latter was designed by the high-entropy engineering concept. The phonon spectrum and ab initio molecular dynamics simulations indicated that the three alloys display stable intermetallic compounds at ambient temperature. The electrical and thermal transport properties of p-type LiCuSe, NaCuTe, and Li0.5Na0.5CuSe0.5Te0.5 alloys were computed as a function of temperature and carrier concentration. The thermoelectric figure of merit for p-type Li0.5Na0.5CuSe0.5Te0.5 alloy was 1.005 and 3.443 at room temperature and 800 K, whereas that of p-type NaCuTe alloy achieved 2.488 at 800 K, which is obviously superior to most of the recently reported p-type half-Heusler thermoelectric materials. A comprehensive analysis of the phonon lifetime, Grüneisen parameters, phonon group velocities, and primitive cell phonon spectrum revealed that high-entropy engineering could introduce non-equivalent atoms and thus enhance phonon scattering, resulting in the reduction of lattice thermal conductivity. Furthermore, numerical simulations demonstrated that high-entropy engineering could improve the thermoelectric performances of half-Heusler alloys effectively, which provides a unique approach for the optimized design of novel thermoelectric materials.

Tuning into urban birdsong: enhancing nature connectedness with an AI-powered wearable

Author Correction: Uncovering functional lncRNAs by scRNA-seq with ELATUS

Creation of hyperoxia superconducting phase in La2CuO4 by applying shear strain under high-pressure compression

We successfully stabilized the hyperoxia superconducting phase of La2CuO4, the parent insulating compound of La-based cuprate superconductors, by applying compression under high pressure and successive shear strains via the process of high-pressure torsion (HPT). Superconducting phases in the La2CuO4 system are created via the hole doping by replacing the La-sites with alkali-earth metals or by overdoping oxygen. However, the present study demonstrates that the HPT processing induces structural strain, and subsequent annealing stabilizes the hyperoxia phase, i.e., the superoxide phase. The superconducting transition temperature Tc systematically varies as a function of the revolution number N in HPT processing under compression of 6 GPa, and Tc has the maximum value of approximately 40 K for N≤1. Stabilized superconducting states intrinsically have a large critical field at the 20 T level. This approach proposes a high-pressure material synthesis method that is useful for mechanically tuning carriers in insulating La2CuO4.

SRADHO: statistical reduction approach with deep hyper optimization for disease classification using artificial intelligence

Defluorinative functionalization approach led by difluoromethyl anion chemistry

Modulation of flux-closure polar state for enhanced storage unit and thermal conductivity via dual-probe excitation

Ferroelectric topological structures have broad application prospects for high-density information storage for long-term data retention via topological protection. However, the high-density memory component might generate tremendous power consumption, causing the failure of ferroelectric devices due to the severe thermal effect. There remains an emergent issue on the synchronous achievement of high-density data storage with the decreasing influences of the thermal effects in ferroelectric topological domain structures. Here, we introduce dual-probe excitation to control the symmetry of the electric field and integrate the phase field simulation for modulating the flux-closure ferroelectric domain configuration to simultaneously improve the memory storage unit and thermal conductivity at the nanoscale in PbTiO3 thin film under a piezoresponse force microscopy experiment. It is found that the grown flux-closure polar state in both in-plane directions encourages us to enhance the storage density during dual-probe excitation in topological ferroelectric memory devices. Moreover, the increased number of flux-closure polar states and the decreased density of the domain walls can be obtained by using dual-probe excitation. Finally, we figured out that both the double-staircase-like and paddle-like domain configurations exhibit large storage units and effective thermal conductivity simultaneously under dual-probe excitation. Our study gives a guideline to synchronously improve storage performance and thermal conductivity through multiple-probe excitations in topological ferroelectric materials and devices.