Browse Articles

Scaling and networking a modular photonic quantum computer

Reply to: Causal claims, causal assumptions and protected area impact

Author Correction: High fatigue resistance in a titanium alloy via near-void-free 3D printing

Author Correction: A map of the rubisco biochemical landscape

Combine AI with citizen science to fight poverty

Superelastic titanium alloy has potential for space missions

Streamflow shifts with declining snowfall

Can AI help beat poverty? Researchers test ways to aid the poorest people

Continued Atlantic overturning circulation even under climate extremes

Abstract The Atlantic Meridional Overturning Circulation (AMOC), vital for northwards heat transport in the Atlantic Ocean, is projected to weaken owing to global warming 1 , with significant global climate impacts 2 . However, the extent of AMOC weakening is uncertain with wide variation across climate models 1,3,4 and some statistical indicators suggesting an imminent collapse 5 . Here we show that the AMOC is resilient to extreme greenhouse gas and North Atlantic freshwater forcings across 34 climate models. Upwelling in the Southern Ocean, driven by persistent Southern Ocean winds, sustains a weakened AMOC in all cases, preventing its complete collapse. As Southern Ocean upwelling must be balanced by downwelling in the Atlantic or Pacific, the AMOC can only collapse if a compensating Pacific Meridional Overturning Circulation (PMOC) develops. Remarkably, a PMOC does emerge in almost all models, but it is too weak to balance all of the Southern Ocean upwelling, suggesting that an AMOC collapse is unlikely this century. Our findings reveal AMOC-stabilizing mechanisms with implications for past and future AMOC changes, and hence for ecosystems and ocean biogeochemistry. They suggest that better understanding and estimates of the Southern Ocean and Indo-Pacific circulations are urgently needed to accurately predict future AMOC change.

Reply to: Streamflow shifts with declining snowfall

Quantum technologies need big investments to deliver on their big promises

A lightweight shape-memory alloy with superior temperature-fluctuation resistance

Abstract In advanced applications such as aerospace and space exploration, materials must balance lightness, functionality and extreme thermal fluctuation resistance1,2. Shape-memory alloys show promise with strength, toughness and substantial strain recovery due to superelasticity, but maintaining low mass and effective operation at cryogenic temperatures is challenging3–6. We hereby introduce a new shape-memory alloy that adheres to these stringent criteria. Predominantly composed of Ti and Al with a chemical composition of Ti75.25Al20Cr4.75, this alloy is characterized by a low density (4.36 × 103 kg m− 3) and a high specific strength (185 × 103 Pa m3 per kg) at room temperature, while showing excellent superelasticity. The superelasticity, owing to a reversible stress-induced phase transformation from an ordered body-centred cubic parent phase to an ordered orthorhombic martensite, allows for a recoverable strain exceeding 7%. This functionality persists across a broad range of temperatures, from deep cryogenic 4.2 K to above room temperature, arising from an unconventional temperature dependence of transformation stresses. Below a certain threshold during cooling, the critical transformation stress inversely correlates with temperature. We interpret this behaviour from the perspective of a temperature-dependent anomalous lattice instability of the parent phase. This alloy holds potential in everyday appliances requiring flexible strain accommodation, as well as components designed for extreme environmental conditions such as deep space and liquefied gases.

Atlantic circulation could be more resilient to global warming than was thought

Causal claims, causal assumptions and protected area impact

Hardware-efficient quantum error correction via concatenated bosonic qubits

Artificial photosynthesis directed toward organic synthesis

Remodeling of lipid-foam prototissues by network-wide tension fluctuations induced by active particles

Abstract Recent advances in the field of bottom-up synthetic biology have led to the development of synthetic cells that mimic some features of real cells, such as division, protein synthesis, or DNA replication. Larger assemblies of synthetic cells may be used to form prototissues. However, existing prototissues are limited by their relatively small lateral dimensions or their lack of remodeling ability. Here, we introduce a lipid-based tissue mimetic that can be easily prepared and functionalized, consisting of a millimeter-sized “lipid-foam” with individual micrometer-sized compartments bound by lipid bilayers. We characterize the structural and mechanical properties of the lipid-foam tissue mimetic, and we demonstrate self-healing capabilities enabled by the fluidity of the lipid bilayers. Upon inclusion of bacteria in the tissue compartments, we observe that the tissue mimetic exhibits network-wide tension fluctuations driven by membrane tension generation by the swimming bacteria. Active tension fluctuations facilitate the fluidization and reorganization of the prototissue, providing a versatile platform for understanding and mimicking biological tissues.

Asymmetric rotations slow down diffusion under confinement

Associations of PFAS and OH-PCBs with risk of multiple sclerosis onset and disability worsening

Abstract Exposure to per- and polyfluorinated substances (PFAS) and hydroxylated polychlorinated biphenyls (OH-PCBs) is associated with adverse human health effects, including immunosuppression. It is unknown if these substances can affect the course of autoimmune diseases. This study was based on 907 individuals with multiple sclerosis (MS) and 907 matched controls, where the MS cases were followed longitudinally using the Swedish MS register. We demonstrate sex- and disease-specific differences in serum PFAS concentrations between individuals with MS and controls. Moreover, two OH-PCBs (4-OH-CB187 and 3-OH-CB153) are associated with an increased risk of developing multiple sclerosis, regardless of sex and immigration status. With a clinical follow-up time of up to 18 years, an increase in serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and perfluorodecanoic acid (PFDA) decreases the risk of confirmed disability worsening in both sexes, as well as perfluoroheptanesulfonic acid (PFHpS) and perfluorononanoic acid (PFNA), only in males with MS. These results show previously unknown associations between OH-PCBs and the risk of developing MS, as well as the inverse associations between PFAS exposure and the risk of disability worsening in MS.

Mass-spectrometry-based proteomics: from single cells to clinical applications