Browse Articles

Simulating electron transfer on noisy quantum computers

Abstract While simple spin-boson models have been realized on quantum hardware, simulating extended electronic networks with local vibrational environments remains a fundamental challenge in the presence of non-equilibrium, long-lived electronic-vibrational (vibronic) coherence. We present a framework for the digital-analog simulation of open quantum systems governed by Hamiltonians with linear-vibronic coupling (LVC) and structured vibrational environments. Our approach exploits the intrinsic dissipation of qubits in near-term quantum hardware as a resource to emulate vibrational relaxation, combined with a model-specific error mitigation scheme to filter out noise sources incompatible with the target open system. We validate our strategy by resolving the vibronic transfer spectra of a one-dimensional donor-acceptor chain on IBM superconducting processors, reproducing non-Markovian dynamics and scaling the chain length up to 10 electronic sites, an unprecedented scale for chemical dynamics on quantum computers. Our model of vibronic electron transfer offers a portable, application-oriented benchmark for simulating long-lived entangled states on NISQ computers.

Evidence for volcanic forcing of Holocene cold events

Abstract During the Holocene, the climatic stability of the northern hemisphere was intermittently disrupted by centennial-scale cooling events, whose origins remain unclear. Explosive volcanism is a plausible trigger, yet its potential to drive longer-term (centennial-to-millennial) perturbations remains underexplored. Here, we compile records of explosive volcanism, atmospheric sulphate, climate variability, and glacial dynamics over the past ~12,000 years to test the temporal correspondence between major eruptions and abrupt cooling events, and assess mechanisms linking volcanic forcing to prolonged climatic shifts. Over 80% of Holocene glacial advances occurred within chronological uncertainty of at least one large (M ≥ 7) eruption in the northern hemisphere. Monte Carlo simulations confirm that this relationship is non-random (p < 0.01). Combined with evidence for sea ice expansion, Atlantic Ocean circulation weakening, and southward tropical rain belt displacement, our results suggest that volcanic impacts can persist well beyond aerosol lifetimes, emphasizing the need to consider dynamical feedbacks in Earth system responses to eruptions.

Reference-point dependent reinforcement learning in humans and rats

An artefact-resilient wide bandwidth bidirectional graphene neural interface

China moves AI brain implants from trials towards real-world use

Brain FGF2 and NCAM1 contribute to FGFR1-dependent progression of estrogen receptor-positive breast cancer brain metastases

Abstract Estrogen receptor-positive breast cancer represents a significant proportion of breast cancer brain metastasis but remains understudied. Here we show that FGFR1-amplification, a well-established driver of estrogen receptor-positive breast cancer endocrine resistance, promotes estrogen receptor-positive breast cancer brain metastatic colonization in young and aged female mice, through both canonical FGF2/FGFR1 signaling and non-canonical NCAM1/FGFR1 interactions. Astrocytic FGF2-mediated paracrine activation of FGFR1 promotes breast cancer brain metastasis in estrogen-treated young mice, but FGF2 levels and signaling decrease in the brain with aging and estrogen-depletion. Neuronal and astrocytic NCAM1, which remain unchanged in young and aged brains, promote adhesion to neurons, migration, and growth of estrogen receptor-positive cells, suggesting that interactions with astrocytes and neurons facilitate early estrogen receptor-positive breast cancer brain metastasis colonization through FGFR1. Importantly, FDA-approved FGFR inhibitors effectively block early colonization but not late-stage brain metastases, suggesting prevention of FGFR1+ brain metastases as a window of opportunity for FGFR1 inhibitors.

Bridging quantum mechanics to liquid properties via a universal organic force field

Could this synthetic egg bring back extinct birds? Researchers urge caution

Mapping global resource driven nature loss in the mining sector from 2001 to 2022

Superconductivity from quasiparticle pairing of intervalley coherent state in rhombohedral trilayer graphene

Abstract Superconductivity is observed in rhombohedral trilayer graphene in a narrow regime between the flavour-symmetric state and the symmetry breaking phase, which cannot be described by the conventional Bardeen-Cooper-Schrieffer theory. The measured coherence length, for instance, is roughly two orders of magnitude shorter than the value predicted by the Bardeen-Cooper-Schrieffer relation based on the large fermi velocity and an extremely low charge carrier density of the flavour-symmetric phase. To resolve the discrepancies, we propose that the rhombohedral trilayer graphene superconducting phase arises from the pairing of quasiparticles of the adjacent inter-valley coherent state. We illustrate the superconducting phenomenology using gapped Dirac cones with the chemical potential μ close to the valence band’s edge. Our findings indicate that the transition temperature T c obeys $${T}_{c}\propto {\epsilon }_{D}\exp (-2/{\rho }_{\rm{qp}}U)$$ T c ∝ ϵ D exp ( − 2 / ρ qp U ) with the density of states ρ qp of intervalley coherent state quasiparticles, which is much suppressed compared to predictions from the Bardeen-Cooper-Schrieffer theory. The coherence length ξ we predict behaves according to $$\xi \sim v/\sqrt{\mu {T}_{c}}$$ ξ ~ v / μ T c with v being the velocity of Dirac cone. Applying our assumption to a microscopic model, our predictions align well with experimental data and effectively capture key measurable quantities such as the transition temperature T c and the coherence length ξ `without parameter fine-tuning.

A lipidomics roadmap: from basic research to societal challenges

Retraction Note: Daylight saving time affects European mortality patterns

A plant vesicle-dendritic cell chimera for enhancing cancer immunotherapy

Abstract The tumour microenvironment (TME) causes mitochondrial dysfunction in resident dendritic cells (DCs), resulting in inadequate antigen presentation and weak T cell priming. Herein, we identify hypoxia as a key factor for causing pathological mitochondrial fission in tumour-associated DCs, and develop a plant vesicle-DC chimera to relieve hypoxia-induced mitochondrial dysfunction for enhancing cancer immunotherapy. The biohybrid chimera is fabricated by loading algae-derived nanovesicles (ANVs) with genetically engineered CCR2 overexpressing-DCs. The CCR2-DC-ANVs target tumour by leveraging the C-C motif chemokine ligand 2 (CCL2) in tumours. Upon light exposure, the ANVs produce oxygen and NADPH to resolve hypoxic and oxidative stress, which reverse pathological mitochondrial fission in DCs. Mitochondrial network restoration alleviates endoplasmic reticulum stress, reduces lipid droplet accumulation, and initiates metabolic reprogramming to enhance antigen presentation and T cell priming of CCR2-DC-ANVs in the TME. The biohybrid chimera enhances therapeutic efficiency in humanized mouse models of breast cancer in female mice without requiring external tumour antigens. This approach highlights a cross-species chimera for next-generation DC therapy, and provides the basis for a nanobiotechnology platform to facilitate organelle medicine by combining photosynthesis with immunotherapy.

Improving access to essential medicines via decision-aware machine learning

GWAS of extended prescription analgesic use identifies genetic loci in chronic pain

Bulk spinodal-architected compositionally complex alloy with enhanced energy absorption across a wide temperature range

River oxygen levels are dropping around the world as Earth warms

Metabolic characterization of the tumor microenvironment orchestrates therapeutic strategies and clinical outcomes in pancreatic cancer

In situ ptychographic nanotomography captures activation, mobility, and deactivation of supported catalysts

Abstract Nanoparticles supported on the surface of porous carrier materials are the dominant form of heterogeneous catalysts today. Yet, they suffer from a common deactivation mechanism: the loss of active surface area under industrial use conditions. Deactivation often stems from the sintering of nanoparticles, a mass-transport process whose mechanism and operating length-scale are a topic of controversy. Investigating this process is challenging, requiring not only a behavioral characterization of thousands of individual particles within the spatial confines of a hierarchically structured support but also a characterization of their ensemble behavior and local support interactions. Here, we introduce in situ ptychographic X-ray computed nanotomography as a tool to facilitate this characterization, allowing a local examination of catalysts in their use-geometry under operational-relevant conditions. Applied to methane oxidation over a palladium-on-silica supported catalyst, we reveal two concurrently operating deactivation drivers, short-range ripening and long-range particle migration, each with different temperature and atmosphere dependencies. The latter enables particles to traverse hundreds of nanometers through the support. These observations expand the current understanding of sintering behavior in supported catalysts and demonstrate PXCT’s capability to resolve restructuring processes within complex porous materials.

Machine learning improves health-care access in Sierra Leone