Nature Communications最新文献

The fate of thymine upon excitation by ultraviolet radiation has been the subject of intense debate. Today, it is widely believed that its ultrafast excited state gas phase decay stems from a radiationless transition from the bright ππ* state to a dark nπ* state. However, conflicting theoretical predictions have made the experimental data difficult to interpret. Here we simulate the early gas phase ultrafast dynamics in thymine at the highest level of theory to date. This is made possible by performing wavepacket dynamics with a recently developed coupled cluster method. Our simulation confirms an ultrafast ππ* to nπ* transition (τ = 41 ± 14 fs). Furthermore, the predicted oxygen-edge X-ray absorption spectra agree quantitatively with experiment. We also predict an as-yet uncharacterized πσ* channel that leads to hydrogen dissociation at one of the two N-H bonds. Similar behavior has been identified in other heteroaromatic compounds, including adenine, and several authors have speculated that a similar pathway may exist in thymine. However, this was never confirmed theoretically or experimentally. This prediction calls for renewed efforts to experimentally identify or exclude the presence of this channel.

Mechanisms by which G-patch activators tune the processive multi-tasking ATP-dependent RNA helicase Prp43 (DHX15 in humans) to productively remodel diverse RNA:protein complexes remain elusive. Here, a comparative study between a herein and previously characterized activators, Tma23 and Pxr1, respectively, defines segments that organize Prp43 function during ribosome assembly. In addition to the activating G-patch, we discover an inhibitory segment within Tma23 and Pxr1, I-patch, that restrains Prp43 ATPase activity. Cryo-electron microscopy and hydrogen-deuterium exchange mass spectrometry show how I-patch binds to the catalytic RecA-like domains to allosterically inhibit Prp43 ATPase activity. Tma23 and Pxr1 contain dimerization segments that organize Prp43 into higher-order complexes. We posit that Prp43 function at discrete locations on pre-ribosomal RNA is coordinated through toggling interactions with G-patch and I-patch segments. This could guarantee measured and timely Prp43 activation, enabling precise control over multiple RNA remodelling events occurring concurrently during ribosome formation.

Noncoplanar magnets are excellent candidates for spintronics. However, such materials are difficult to find, and even more so to intentionally design. Here, we report a chemical design strategy that allows us to find a series of noncoplanar magnets—Ln₃Sn₇ (Ln = Dy, Tb)—by targeting layered materials that have decoupled magnetic sublattices with dissimilar single-ion anisotropies and combining those with a square-net topological semimetal sublattice. Ln₃Sn₇ shows high carrier mobilities upwards of 17,000 cm² ⋅ V⁻¹ ⋅ s⁻¹, and hosts noncoplanar magnetic order. This results in a giant Hall response with an anomalous Hall angle of 0.17 and Hall conductivity of over 42,000 Ω⁻¹ ⋅ cm⁻¹—a value over an order of magnitude larger than the established benchmarks in Co₃Sn₂S₂ and Fe thin films.

Acute kidney injury (AKI), typically caused by ischemia, is a common clinical complication with a poor prognosis. Although proteinuria is an important prognostic indicator of AKI, the underlying causal mechanism remains unclear. In vitro studies suggest that podocytes have high ATP demands to maintain their structure and function, however, analyzing their ATP dynamics in living kidneys has been technically challenging. Here, using intravital imaging to visualize a FRET-based ATP biosensor expressed systemically in female mice due to their suitability for glomerular imaging, we monitor the in vivo ATP dynamics in podocytes during ischemia reperfusion injury. ATP levels decrease during ischemia, but recover after reperfusion in podocytes, exhibiting better recovery than in glomerular endothelial cells. However, prolonged ischemia results in insufficient ATP recovery in podocytes, which is inversely correlated with mitochondrial fragmentation and foot process effacement during the chronic phase. Furthermore, preventing mitochondrial fission via pharmacological inhibition ameliorates podocyte injury in vitro, ex vivo, and in vivo. Thus, these findings provide several insights into how ATP depletion and mitochondrial fragmentation contribute to podocyte injury after ischemic AKI and could potentially be therapeutic targets.

D-amino acids, found in excess in a minority of organisms and crucial for marine invertebrates, contrast with the more common L-amino acids in most life forms. The local prebiotic origin of D-amino acid enantiomeric excess in natural systems remains an unsolved conundrum. Herein, we demonstrate the formation of enantiomeric excess (ee) D-amino acids through photocatalytic reductive amination of α-keto acids on natural pyrite. Various amino acids with ee values in the range of 14.5–42.4%, are formed. The wavy arrangement of atoms on the surface of pyrite is speculated to lead to the preferential formation of D-amino acids. This work reveals the intrinsic asymmetric photocatalytic activity of pyrite, which could expand understandings on mechanism of asymmetric catalysis and chirality of inorganic crystals. Furthermore, it provides a plausible pathway for the prebiotic formation of D-amino acids, adding further evidence to the origin of D-amino acids enantiomeric excess in natural systems.

The hybrid ferromagnet-superconductor heterostructures have attracted extensive attention as they potentially host topological superconductivity. Relevant experimental signatures have recently been reported in CrBr₃/NbSe₂ ferromagnet-superconductor heterostructure, but controversies remain. Here, we reinvestigate CrBr₃/NbSe₂ by an ultralow temperature scanning tunneling microscope with higher spatial and energy resolutions. We find that the single-layer CrBr₃ film is insulating and acts likely as a vacuum barrier, the measured superconducting gap and vortex state on it are nearly the same as those of NbSe₂ substrate. Meanwhile, in-gap features are observed at the edges of CrBr₃ island, which display either a zero-energy conductance peak or a pair of particle-hole symmetric bound states. They are discretely distributed at the edges of CrBr₃ film, and their appearance is found closely related to the atomic lattice reconstruction near the edges. By increasing tunneling transmissivity, the zero-energy conductance peak quickly splits, while the pair of nonzero in-gap bound states first approach each other, merge, and then split again. These behaviors are unexpected for Majorana edge modes, but in consistent with the conventional Yu-Shiba-Rusinov states. Our results provide critical information for further understanding the interfacial coupling in CrBr₃/NbSe₂ heterostructure.

A fungal effector that is toxic to plant cells was identified in Verticillium dahliae. The effector contains a non-canonical Common in several Fungal Extracellular Membrane proteins (CFEM) domain, a tandem repeat region consisting of four 14-amino acid repeats rich in proline, and a C-terminal region, thus is designated V. dahliae tetrapeptide repeat protein (VdTRP). The membrane targeting of VdTRP is vital for its cell toxicity. CFEM mediates the membrane targeting and the tandem repeat region exerts the toxic function upon cell membrane. The chitinase-like 1 (CTL1), an essential apoplastic protein of cotton, can redirect VdTRP from cell membrane to apoplast. Transgenic cotton overexpressing CTL1 greatly enhances cotton resistance to V. dahliae without affecting cotton growth and development, implicating its potential application in breeding cotton with high wilt resistance. Our data demonstrates that genetic manipulation of effector target constitutes potential strategy for improving crop resistance to fungal pathogens.

Computing the exact rate at which entanglement can be distilled from noisy quantum states is one of the longest-standing questions in quantum information. We give an exact solution for entanglement distillation under the set of dually non-entangling (DNE) operations—a relaxation of the typically considered local operations and classical communication, comprising all channels which preserve the sets of separable states and measurements. We show that the DNE distillable entanglement coincides with a modified version of the regularised relative entropy of entanglement in which the arguments are measured with a separable measurement. Ours is only the second known regularised formula for the distillable entanglement under any class of free operations in entanglement theory, after that given by Devetak and Winter for (one-way) local operations and classical communication. An immediate consequence of our finding is that, under DNE, entanglement can be distilled from any entangled state. As our second main result, we construct a general upper bound on the DNE distillable entanglement, using which we prove that the separably measured relative entropy of entanglement can be strictly smaller than the regularisation of the standard relative entropy of entanglement, solving an open problem posed by Li and Winter. Finally, we study also the reverse task of entanglement dilution and show that the restriction to DNE operations does not change the entanglement cost when compared with the larger class of non-entangling operations. This implies a strong form of irreversiblility of entanglement theory under DNE operations: even when asymptotically vanishing amounts of entanglement may be generated, entangled states cannot be converted reversibly.

Neuroinflammation in the central nervous system (CNS), driven largely by resident phagocytes, has been proposed as a significant contributor to disability accumulation in multiple sclerosis (MS) but has not been addressed therapeutically. Bruton’s tyrosine kinase (BTK) is expressed in both B-lymphocytes and innate immune cells, including microglia, where its role is poorly understood. BTK inhibition may provide therapeutic benefit within the CNS by targeting adaptive and innate immunity-mediated disease progression in MS. Using a CNS-penetrant BTK inhibitor (BTKi), we demonstrate robust in vivo effects in mouse models of MS. We further identify a BTK-dependent transcriptional signature in vitro, using the BTKi tolebrutinib, in mouse microglia, human induced pluripotent stem cell (hiPSC)-derived microglia, and a complex hiPSC-derived tri-culture system composed of neurons, astrocytes, and microglia, revealing modulation of neuroinflammatory pathways relevant to MS. Finally, we demonstrate that in MS tissue BTK is expressed in B-cells and microglia, with increased levels in lesions. Our data provide rationale for targeting BTK in the CNS to diminish neuroinflammation and disability accumulation.

Aluminium (Al)-tolerant beneficial bacteria confer resistance to Al toxicity to crops in widely distributed acidic soils. However, the mechanism by which microbial consortia maintain Al tolerance under acid and Al toxicity stress remains unknown. Here, we demonstrate that a soil bacterial consortium composed of Rhodococcus erythropolis and Pseudomonas aeruginosa exhibit greater Al tolerance than either bacterium alone. P. aeruginosa releases the quorum sensing molecule 2-heptyl-1H-quinolin-4-one (HHQ), which is efficiently degraded by R. erythropolis. This degradation reduces population density limitations and further enhances the metabolic activity of P. aeruginosa under Al stress. Moreover, R. erythropolis converts HHQ into tryptophan, promoting the synthesis of peptidoglycan, a key component for cell wall stability, thereby improving the Al tolerance of R. erythropolis. This study reveals a metabolic cross-feeding mechanism that maintains microbial Al tolerance, offering insights for designing synthetic microbial consortia to sustain food security and sustainable agriculture in acidic soil regions.