Browse Articles

Twisted atomic magnetic tunnel junctions with multiple nonvolatile states

Abstract Magnetic tunnel junctions (MTJs), a key spintronic device, have shown rapid development recently using two-dimensional (2D) magnets. In particular, MTJs formed from twisted 2D antiferromagnets (AFMs) push nonvolatile magnetic information storage to the atomic limit. Here we demonstrate 2D twisted MTJs with multiple distinct nonvolatile states. Asymmetric MTJ structures formed by twisting a single ferromagnetic CrSBr monolayer and a single antiferromagnetic CrSBr bilayer exhibit two distinct states with up to 700% tunneling magnetoresistance in zero magnetic field at 2 K. By adding a second CrSBr monolayer to form a second twisted interface, four nonvolatile states can be accessed in zero magnetic field. More importantly, any one state among the four states can be switched to any other using magnetic fields. We further demonstrate all-antiferromagnetic MTJs with three twisted antiferromagnetic CrSBr bilayers that exhibit multiple nonvolatile states. Our work shows that it is possible to store multiple-state magnetic information in a single device by integrating several twisted interfaces in the atomic limit.

AI offers way to image and assess clinical cell samples

Historical and future extremes of cauvery basin analysed using cmip6 models and ETCCDI indices

scTWAS: a powerful statistical framework for single-cell transcriptome-wide association studies

Abstract Transcriptome-wide association studies (TWAS) have successfully identified genes associated with complex traits and diseases, but most have been performed using bulk gene expression data, which aggregate signals across heterogeneous cell types. Population-scale single-cell RNA sequencing data now make it possible to perform TWAS at the cell-type resolution, but present unique challenges due to strong noises, technical variations, and high sparsity. Here, we propose scTWAS, a statistical method to conduct cell-type-specific TWAS using single-cell data. Leveraging a latent-variable model and moment-based estimation to address the challenges of single-cell data, scTWAS consistently improves the prediction of genetically regulated gene expression across cell types in both blood and brain tissues. Compared to existing methods, scTWAS identifies substantially more gene-trait associations across 29 hematological traits and three immune-related diseases in immune cell types. An application to Alzheimer’s disease also reveals cell-subtype-specific associations, including MS4A6A in the disease-associated microglial subtype and PPP1R37 in the inflammatory microglial subtype.

Antagonistic effects of amino acids support abiotic nano-environments in clay

Abstract Prebiotic chemistry in nano-environments confined within catalytic mineral media is emerging as a promising frontier in origins-of-life research. Such confined spaces exhibit physicochemical properties distinct from bulk conditions, enabling out-of-equilibrium processes such as condensation reactions in aqueous media. Here, we demonstrate that a yin-yang interplay of organo–clay interactions generates and supports a variety of confined geochemical nano-environments within clay layers and facilitates the persistence of partial exfoliation. We investigate how the structure of Ca-montmorillonite clay is affected by exposure to aqueous amino acid mixtures containing proteinogenic species (L-lysine or L-arginine) and their 1:40 mixture with the meteorite-common, non-proteinogenic $$\gamma$$ -aminobutyric acid. Using attenuated total reflectance Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and electron microscopy, we reveal opposing effects of the different amino acids on the clay’s structure. Lysine and arginine intercalate between clay layers, bridge across them and suppress swelling, whereas $$\gamma$$ -aminobutyric acid induces pronounced layer distortion, exfoliation and nanocavity formation, even in the presence of the strongly-interacting species. The contrasting, complementary effects between fixation of the interlayer and formation of nano-compartments create and sustain diverse nano-environments. This balance could play a role in shaping nano-environments that facilitate prebiotic polymerisation and other chemistry central to life’s emergence on rocky bodies.

A Soft-Robotic Biomimetic Benchtop Model for Esophageal Motility Simulation

Smart technologies for enhancing greenhouse production management under climate and economic challenges

Impaired $$\alpha$$-Synuclein aggregate clearance in neuronal cells drive their spread to microglia through tunneling nanotubes

Abstract Tunneling nanotubes (TNTs) play a crucial role in intercellular communication, enabling transfer of molecular cargoes over long distances between connected cells. Previous studies have demonstrated efficient, directional transfer of $$\alpha$$ α -Synuclein ( $$\alpha$$ α -Syn) aggregates from neurons to microglia, with endosomal trafficking and lysosomal processing identified as the primary events following $$\alpha$$ α -Syn internalization. Using human neuronal and microglial cell lines, we show that microglia exhibit higher lysosomal turnover, particularly through lysophagy, whereas neuronal lysosomes display compromised degradative capacity and impaired autophagic flux upon $$\alpha$$ α -Syn exposure, resulting in compromised aggregate clearance. Such a response to $$\alpha$$ α -Syn aggregates is also conserved in human iPSC-derived neurons and microglia. Moreover, perturbing aggregate clearance via autophagy inhibition enhances TNT-mediated transfer of $$\alpha$$ α -Syn from neuronal cells to microglia. Microglia co-cultured with $$\alpha$$ α -Syn-containing neurons upregulate autophagy flux, enabling efficient degradation of the transferred aggregates. These results highlight dysfunctional autophagy in neurons as a key driver outsourcing $$\alpha$$ α -Syn aggregates to microglia.

A deep learning framework for breast cancer diagnosis using Swin Transformer and Dual-Attention Multi-scale Fusion Network

PTBP1 inhibition reprograms myogenesis to rescue impaired muscle regeneration in mdx mice through correcting E2A splicing

Privilege, power and vulnerability in science: precarious funding can prompt unethical ties

Achieving near-net-zero energy in hot climates through synergistic retrofit interventions and uncertainty quantification

Discovery and engineering of bacterial P450s for C-14 hydroxylation in ent-kaurane diterpenoids

How data can help to guide NIH funding policy

Intracellular calcium handling dysfunction contributes to behavioural deficits leading to mortality of honey bees after acute contact exposure to the insecticide cyantraniliprole

Global error signal guides local optimization in mismatch calculation

From cancer to Alzheimer’s: could a renewed focus on energy transform biomedicine?

Higher-dimensional Fermiology in bulk moiré metals

MultiScaleWave: a wavelet-based multiscale framework for univariate time series forecasting

Chiral orbital lasing in a twisted bilayer metasurface

Abstract Chirality is a fundamental concept in physics, core to many phenomena in nonlinear optics, quantum physics and topological photonics. Photons are intrinsically chiral when carrying spin angular momentum, whereas orbital angular momentum can induce chirality when photons interact with structures with broken mirror symmetry. Here, we observe orbital chiral lasing from a twisted bilayer photonic structure, by leveraging its inherent structural chirality. We design and fabricate a Moiré-type optical structure consisting of two semiconductor membrane metasurfaces. By optically pumping the twisted bilayer, we achieve single-mode lasing over a broad spectral range of 250 nm. The lasing emission exhibits chiral orbital characteristics, arising from helical and non-Hermitian couplings between collective guided resonances rotating clockwise and counterclockwise and confirmed by polarization-resolved imaging and self-interference measurements. The observed chiral orbital lasing from a twisted photonic structure can contribute to diverse applications of chiral light in diagnostics, optical manipulation and communication with light.