查看更多>>摘要：Owing to the outstanding properties provided by nontrivial band topology,topological phases of matter are considered as a promising platform towards low-dissipation electronics,efficient spin-charge conver-sion,and topological quantum computation.Achieving ferroelectricity in topological materials enables the non-volatile control of the quantum states,which could greatly facilitate topological electronic research.However,ferroelectricity is generally incompatible with systems featuring metallicity due to the screening effect of free carriers.In this study,we report the observation of memristive switching based on the ferroelectric surface state of a topological semimetal(TaSe4)2I.We find that the surface state of(TaSe4)2I presents out-of-plane ferroelectric polarization due to surface reconstruction.With the com-bination of ferroelectric surface and charge-density-wave-gapped bulk states,an electric-switchable bar-rier height can be achieved in(TaSe4)2I-metal contact.By employing a multi-terminal-grounding design,we manage to construct a prototype ferroelectric memristor based on(TaSe4)2I with on/off ratio up to 103,endurance over 103 cycles,and good retention characteristics.The origin of the ferroelectric surface state is further investigated by first-principles calculations,which reveal an interplay between ferroelec-tricity and band topology.The emergence of ferroelectricity in(TaSe4)2I not only demonstrates it as a rare but essential case of ferroelectric topological materials,but also opens new routes towards the imple-mentation of topological materials in functional electronic devices.
查看更多>>摘要：The Bloch band theory and Brillouin zone(BZ)that characterize wave-like behaviors in periodic mediums are two cornerstones of contemporary physics,ranging from condensed matter to topological physics.Recent theoretical breakthrough revealed that,under the projective symmetry algebra enforced by arti-ficial gauge fields,the usual two-dimensional(2D)BZ(orientable Brillouin two-torus)can be fundamen-tally modified to a non-orientable Brillouin Klein bottle with radically distinct manifold topology.However,the physical consequence of artificial gauge fields on the more general three-dimensional(3D)BZ(orientable Brillouin three-torus)was so far missing.Here,we theoretically discovered and experimentally observed that the fundamental domain and topology of the usual 3D BZ can be reduced to a non-orientable Brillouin Klein space or an orientable Brillouin half-turn space in a 3D acoustic crystal with artificial gauge fields.We experimentally identify peculiar 3D momentum-space non-symmorphic screw rotation and glide reflection symmetries in the measured band structures.Moreover,we experi-mentally demonstrate a novel stacked weak Klein bottle insulator featuring a nonzero Z2 topological invariant and self-collimated topological surface states at two opposite surfaces related by a nonlocal twist,radically distinct from all previous 3D topological insulators.Our discovery not only fundamentally modifies the fundamental domain and topology of 3D BZ,but also opens the door towards a wealth of previously overlooked momentum-space multidimensional manifold topologies and novel gauge-symmetry-enriched topological physics and robust acoustic wave manipulations beyond the existing paradigms.
查看更多>>摘要：The practical application of lithium-sulfur(Li-S)batteries is inhibited by the shuttle effect of lithium polysulfides(LiPSs)and slow polysulfide redox kinetics on the S cathode as well as the uncontrollable growth of dendrites on the Li metal anode.Therefore,both cathode and anode sides must be considered when modifying Li-S batteries.Herein,two-dimensional(2D)ultrathin CoSe2 nanobelts are in situ grown on 2D N-doped MXene nanosheets(CoSe2@N-MXene)via one-step solvothermal process for the first time.Owing to its unique 2D/2D structure,CoSe2@N-MXene can be processed to crumpled nanosheets by freeze-drying and flexible and freestanding films by vacuum filtration.These crumpled CoSe2@N-MXene nanosheets with abundant active sites and inner spaces can act as S hosts to accelerate polysulfide redox kinetics and suppress the shuttle effect of LiPSs owing to their strong adsorption ability and cat-alytic conversion effect with LiPSs.Meanwhile,the CoSe2@N-MXene film(CoSe2@NMF)can act as a cur-rent collector to promote uniform Li deposition because it contains lithiophilic CoSe2 and N sites.Under the systematic effect of CoSe2@N-MXene on S cathode and Li metal anode,the electrochemical and safety performance of Li-S batteries are improved.CoSe2@NMF also shows excellent storage performances in flexible energy storage devices.
查看更多>>摘要：High-voltage and fast-charging LiCoO2(LCO)is key to high-energy/power-density Li-ion batteries.However,unstable surface structure and unfavorable electronic/ionic conductivity severely hinder its high-voltage fast-charging cyclability.Here,we construct a Li/Na-B-Mg-Si-O-F-rich mixed ion/electron interface network on the 4.65 V LCO electrode to enhance its rate capability and long-term cycling sta-bility.Specifically,the resulting artificial hybrid conductive network enhances the reversible conversion of Co3+/4+/O2-/n-redox by the interfacial ion-electron cooperation and suppresses interface side reac-tions,inducing an ultrathin yet compact cathode electrolyte interphase.Simultaneously,the derived near-surface Na+/Mg2+/Si4+-pillared local intercalation structure greatly promotes the Li+diffusion around the 4.55 V phase transition and stabilizes the cathode interface.Finally,excellent 3 C(1 C=274 mA g-1)fast charging performance is demonstrated with 73.8％capacity retention over 1000 cycles.Our findings shed new insights to the fundamental mechanism of interfacial ion/electron synergy in sta-bilizing and enhancing fast-charging cathode materials.
查看更多>>摘要：Ⅲ-nitride materials are of great importance in the development of modern optoelectronics,but they have been limited over years by low light utilization rate and high dislocation densities in heteroepitaxial films grown on foreign substrate with limited refractive index contrast and large lattice mismatches.Here,we demonstrate a paradigm of high-throughput manufacturing bioinspired microstructures on warped sub-strates by flexible nanoimprint lithography for promoting the light extraction capability.We design a flex-ible nanoimprinting mold of copolymer and a two-step etching process that enable high-efficiency fabrication of nanoimprinted compound-eye-like Al2O3 microstructure(NCAM)and nanoimprinted compound-eye-like SiO2 microstructure(NCSM)template,achieving a 6.4-fold increase in throughput and 25％savings in economic costs over stepper projection lithography.Compared to NCAM template,we find that the NCSM template can not only improve the light extraction capability,but also modulate the morphology of AlN nucleation layer and reduce the formation of misoriented GaN grains on the inclined sidewall of microstructures,which suppresses the dislocations generated during coalescence,resulting in 40％reduction in dislocation density.This study provides a low-cost,high-quality,and high-throughput solution for manufacturing microstructures on warped surfaces of Ⅲ-nitride optoelectronic devices.
查看更多>>摘要：Tactile sensing provides robots the ability of object recognition,fine operation,natural interaction,etc.However,in the actual scenario,robotic tactile recognition of similar objects still faces difficulties such as low efficiency and accuracy,resulting from a lack of high-performance sensors and intelligent recog-nition algorithms.In this paper,a flexible sensor combining a pyramidal microstructure with a gradient conformal ionic gel coating was demonstrated,exhibiting excellent signal-to-noise ratio(48 dB),low detection limit(1 Pa),high sensitivity(92.96 kPa-1),fast response time(55 ms),and outstanding stability over 15,000 compression-release cycles.Furthermore,a Pressure-Slip Dual-Branch Convolutional Neural Network(PSNet)architecture was proposed to separately extract hardness and texture features and per-form feature fusion.In tactile experiments on different kinds of leaves,a recognition rate of 97.16％was achieved,and surpassed that of human hands recognition(72.5％).These researches showed the great potential in a broad application in bionic robots,intelligent prostheses,and precise human-computer interaction.
查看更多>>摘要：Stem cells remain in a quiescent state for long-term maintenance and preservation of potency;this pro-cess requires fine-tuning regulatory mechanisms.In this study,we identified the epigenetic landscape along the developmental trajectory of skeletal stem cells(SSCs)in skeletogenesis governed by a key reg-ulator,Ptip(also known as Paxip1,Pax interaction with transcription-activation domain protein-1).Our results showed that Ptip is required for maintaining the quiescence and potency of SSCs,and loss of Ptip in type Ⅱ collagen(Col2)+progenitors causes abnormal activation and differentiation of SSCs,impaired growth plate morphogenesis,and long bone dysplasia.We also found that Ptip suppressed the glycolysis of SSCs through downregulation of phosphoglycerate kinase 1(Pgk1)by repressing histone H3 lysine 27 acetylation(H3K27ac)at the promoter region.Notably,inhibition of glycolysis improved the function of SSCs despite Ptip deficiency.To the best of our knowledge,this is the first study to establish an epigenetic framework based on Ptip,which safeguards skeletal stem cell quiescence and potency through metabolic control.This framework is expected to improve SSC-based treatments of bone developmental disorders.
查看更多>>摘要：Obstructive sleep apnea(OSA)is a serious type of sleep disorder that can lead to cardiometabolic and neurocognitive diseases.We utilized smart device-based photoplethysmography technology to collect sleep data from the Chinese population from 2019 to 2022.Distributed lag nonlinear models combined with a generalized nonlinear model or a linear mixed effects model were used to investigate the short-term associations between daily temperature and indicators of OSA severity.We included a total of 6,232,056 d of sleep monitoring data from 51,842 participants with moderate to severe risk of OSA from 313 Chinese cities.The relationships between ambient temperature and OSA exacerbation,apnea-hypopnea index(AHI),and minimum oxygen saturation(MinSpO2)were almost linear and present only on the same day.Higher temperatures were associated with a greater risk of OSA exacerbation,with an 8.4％(95％confidence interval(CI):7.6％-9.3％)increase per 10 ℃ increase in temperature.A 10 ℃ increase in daily temperature corresponded to an AHI increase of 0.70 events/h(95％CI:0.65-0.76)and a MinSpO2 decrease of 0.18％(95％CI:0.16％-0.19％).Exposure to elevated temperatures during the night can also lead to adverse effects.The effects of higher temperatures on OSA severity were stron-ger among men,participants with a body mass index ≥ 24 kg/m2,those aged 45 years and older,indi-viduals with a history of hypertension and diabetes,and during the cold season.This large-scale,nationwide,longitudinal study provides robust evidence suggesting that higher ambient temperatures mav immediately worsen OSA.
查看更多>>摘要：Targeting oncogenic mutant p53 represents an attractive strategy for cancer treatment due to the high frequency of gain-of-function mutations and ectopic expression in various cancer types.Despite exten-sive efforts,the absence of a druggable active site for small molecules has rendered these mutants ther-apeutically non-actionable.Here we develop a selective and effective proteolysis-targeting chimera(PROTAC)for p53-R175H,a common hotspot mutant with dominant-negative and oncogenic activity.Using a novel iterative molecular docking-guided post-SELEX(systematic evolution of ligands by expo-nential enrichment)approach,we rationally engineer a high-performance DNA aptamer with improved affinity and specificity for p53-R175H.Leveraging this resulting aptamer as a binder for PROTACs,we suc-cessfully developed a selective p53-R175H degrader,named dp53m.dp53m induces the ubiquitin-protea some-dependent degradation of p53-R175H while sparing wildtype p53.Importantly,dp53m demon-strates significant antitumor efficacy in p53-R1 75H-driven cancer cells both in vitro and in vivo,without toxicity.Moreover,dp53m significantly and synergistically improves the sensitivity of these cells to cis-platin,a commonly used chemotherapy drug.These findings provide evidence of the potential therapeu-tic value of dp53m in p53-R175H-driven cancers.
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