查看更多>>摘要：Metal nanomaterials can facilitate microbial extracellular electron transfer(EET)in the electrochemically active biofilm.However,the role of nanomaterials/bacteria interaction in this process is still unclear.Here,we reported the single-cell voltammetric imaging of Shewanella oneidensis MR-1 at the single-cell level to elucidate the metal-enhanced EET mechanism in vivo by the Fermi level-responsive graphene electrode.Quantified oxidation currents of～20 fA were observed from single native cells and gold nanoparticle(AuNP)-coated cells in linear sweep voltammetry analysis.On the contrary,the oxidation potential was reduced by up to 100 mV after AuNP modification.It revealed the mechanism of AuNP-catalyzed direct EET decreasing the oxidation barrier between the outer membrane cytochromes and the electrode.Our method offered a promising strategy to understand the nanomaterials/bacteria interaction and guide the rational construction of EET-related microbial fuel cells.
查看更多>>摘要：Efficient hemostasis during emergency trauma with massive bleeding remains a critical challenge in prehospital settings.Thus,multiple hemostatic strategies are critical for treating large bleeding wounds.In this study,inspired by bombardier beetles to eject toxic spray for defense,a shape-memory aerogel with an aligned microchannel structure was proposed,employing thrombin-carrying microparticles loaded as a built-in engine to generate pulse ejections for enhanced drug permeation.Bioinspired aerogels,after contact with blood,can rapidly expand inside the wound,offering robust physical barrier blocking,sealing the bleeding wound,and generating a spontaneous local chemical reaction causing an explosive-like generation of C02 microbubbles,which provide propulsion thrust to accelerate burst ejection from arrays of microchannels for deeper and faster drug diffusion.The ejection behavior,drug release kinetics,and permeation capacity were evaluated using a theoretical model and experimentally demonstrated.This novel aerogel showed remarkable hemostatic performance in severely bleeding wounds in a swine model and demonstrated good degradability and biocompatibility,displaying great potential for clinical application in humans.
查看更多>>摘要：Although neuroelectrochemical sensing technology offers unique benefits for neuroscience research,its application is limited by substantial interference in complex brain environments while ensuring biosafety requirements.In this study,we introduced poly(3-hexylthiophene)(P3HT)and nitrogen-doped multiwalled carbon nanotubes(N-MWCNTs)to construct a composite membrane-modified carbon fiber microelectrode(CFME/P3HT-N-MWCNTs)for ascorbic acid(AA)detection.The microelectrode presented good linearity,selectivity,stability,antifouling,and biocompatibility and exhibited great performance for application in neuroelectrochemical sensing.Subsequently,we applied CFME/P3HT-N-MWCNTs to monitor AA release from in vitro nerve cells,ex vivo brain slices,and in vivo living rat brains and determined that glutamate can induce cell edema and AA release.We also found that glutamate activated the N-methyl-D-aspartic acid receptor,which enhanced Na+and Cl-inflow to induce osmotic stress,resulting in cytotoxic edema and ultimately AA release.This study is the first to observe the process of glutamate-induced brain cytotoxic edema with AA release and to reveal the mechanism.Our work can benefit the application of P3HT in in vivo implant microelectrode construction to monitor neurochemicals,understand the molecular basis of nervous system diseases,and discover certain biomarkers of brain diseases.
查看更多>>摘要：Nanocarriers have therapeutic potential to facilitate drug delivery,including biological agents,small-molecule drugs,and nucleic acids.However,their efficiency is limited by several factors;among which,endosomal/lysosomal degradation after endocytosis is the most important.This review summarizes advanced strategies for overcoming endosomal/lysosomal barriers to efficient nanodrug delivery based on the perspective of cellular uptake and intracellular transport mechanisms.These strategies include promoting endosomal/lysosomal escape,using non-endocytic methods of delivery to directly cross the cell membrane to evade endosomes/lysosomes and making a detour pathway to evade endosomes/lysosomes.On the basis of the findings of this review,we proposed several promising strategies for overcoming endosomal/lysosomal barriers through the smarter and more efficient design of nanodrug delivery systems for future clinical applications.
查看更多>>摘要：Thermally activated delayed fluorescence(TADF)materials with both high photoluminescence quantum yield(PLQY)and fast reverse intersystem crossing(RISC)are strongly desired to realize efficient and stable organic light-emitting diodes(OLEDs).Control of excited-state dynamics via molecular design plays a central role in optimizing the PLQY and RISC rate of TADF materials but remains challenging.Here,3 TADF emitters possessing similar molecular structures,similar high PLQYs(89.5％to 96.3％),and approximate energy levels of the lowest excited singlet states(S1),but significantly different spin-flipping RISC rates(0.03 × 106 s-1 vs.2.26 × 106 s-1)and exciton lifetime(297.1 to 332.8 μs vs.6.0 μs)were systematically synthesized to deeply investigate the feasibility of spin-flip between charge-transfer excited states(3CT-1CT)transition.Experimental and theoretical studies reveal that the small singlet-triplet energy gap together with low RISC reorganization energy between the 3CT and 1CT states could provide an efficient RISC through fast spin-flip 3CT-1CT transition,without the participation of an intermediate locally excited state,which has previously been recognized as being necessary for realizing fast RISC.Finally,the OLED based on the champion TADF emitter achieves a maximum external quantum efficiency of 27.1％,a tiny efficiency roll-off of 4.1％at 1,000 cd/m2,and a high luminance of 28,150 cd/m2,which are markedly superior to those of the OLEDs employing the other 2 TADF emitters.
查看更多>>摘要：Hepatic ischemia-reperfusion(IR)injury is a serious clinical problem that complicates liver resection and transplantation.Despite recent advances in understanding of the pathophysiology of hepatic IR injury,effective interventions and therapeutics are still lacking.Here,we examined the role of transient receptor potential melastatin 2(TRPM2),a Ca2+-permeable,non-selective cation channel,in mediating hepatic IR injury.Our data showed that TRPM2 deficiency attenuated IR-induced liver dysfunction,inflammation,and cell death in mice.Moreover,RNA sequencing analysis indicated that TRPM2-induced IR injury occurs via ferroptosis-related pathways.Consistently,as a ferroptosis inducer,(1S,3R)-RSL3 treatment induced mitochondrial dysfunction in hepatocytes and a TRPM2 inhibitor suppressed this.Interestingly,TRPM2-mediated calcium influx caused mitochondrial calcium accumulation via the mitochondrial Ca2+-selective uniporter and increased the expression level of arachidonate 12-lipoxygenase(ALOX12),which results in mitochondrial lipid peroxidation during hepatic IR injury.Furthermore,hepatic IR injury-induced ferroptosis was obviously relieved by a TRPM2 inhibitor or calcium depletion,both in vitro and in vivo.Collectively,these findings demonstrate a crucial role for TRPM2-mediated ferroptosis in hepatic IR injury via increased Ca2+-induced ALOX12 expression,indicating that pharmacological inhibition of TRPM2 may provide an effective therapeutic strategy for hepatic IR injury-related diseases,such as during liver resection and transplantation.
查看更多>>摘要：Cell replacement therapy using neural progenitor cells(NPCs)has been shown to be an effective treatment for ischemic stroke.However,the therapeutic effect is unsatisfactory due to the imbalanced homeostasis of the local microenvironment after ischemia.Microenvironmental acidosis is a common imbalanced homeostasis in the penumbra and could activate acid-sensing ion channels 1a(ASIC1a),a subunit of proton-gated cation channels following ischemic stroke.However,the role of ASIC1a in NPCs post-ischemia remains elusive.Here,our results indicated that ASIC1a was expressed in NPCs with channel functionality,which could be activated by extracellular acidification.Further evidence revealed that ASIC1a activation inhibited NPC migration and neurogenesis through RhoA signaling-mediated reorganization of filopodia formation,which could be primarily reversed by pharmacological or genetic disruption of ASIC1a.In vivo data showed that the knockout of the ASIC1a gene facilitated NPC migration and neurogenesis in the penumbra to improve behavioral recovery after stroke.Subsequently,ASIC1a gain of function partially abrogated this effect.Moreover,the administration of ASIC1a antagonists(amiloride or Psalmotoxin 1)promoted functional recovery by enhancing NPC migration and neurogenesis.Together,these results demonstrate targeting ASIC1a is a novel strategy potentiating NPC migration toward penumbra to repair lesions following ischemic stroke and even for other neurological diseases with the presence of niche acidosis.
查看更多>>摘要：Temperature sensing is of high value in the wearable healthcare,robotics/prosthesis,and noncontact physiological monitoring.However,the common mechanic deformation,including pressing,bending,and stretching,usually causes undesirable feature size changes to the inner conductive network distribution of temperature sensors,which seriously influences the accuracy.Here,inspired by the transient receptor potential mechanism of biological thermoreceptors that could work precisely under various skin contortions,we propose an MXene/Clay/poly(N-isopropylacrylamide)(PNIPAM)(MCP)hydrogel with high stretchability,spike response,and deformation insensitivity.The dynamic spike response is triggered by the inner conductive network transformation from the 3-dimensional structure to the 2-dimensional surface after water being discharged at the threshold temperature.The water discharge is solely determined by the thermosensitivity of PNIPAM,which is free from mechanical deformation,so the MCP hydrogels can perform precise threshold temperature(32 ℃)sensing under various deformation conditions,i.e.,pressing and 15％stretching.As a proof of concept,we demonstrated the applications in plant electronics for the real-time surface temperature monitoring and skin electronics for communicating between human and machines.Our research opens venues for the accurate temperature-threshold sensation on the complicated surface and mechanical conditions.
查看更多>>摘要：Sustained wear damages on the sliding surfaces of alloys are generally the culprit responsible for the failure of various mechanical systems.Inspired by high-entropy effects,here we deliberately deploy nanohierarchical architecture with composition undulation in a Ni50(AlNbTiV)50 complex concentrated alloy,which yields ultralow wear rate within the order of 10-7 to 10-6 mm3/Nm between room temperature and 800 ℃.Such remarkable wear resistance heretofore represents one of the highest wear resistance reported for the bulk alloys or composites,and originates from the multi-type adaptive friction interface protection governed by intrinsically nano-coupled grains and nanoprecipitates.This cooperative heterostructure releases gradient frictional stress in stages upon wear at room temperature through the coexistence of multiple deformation pathways while activating a dense nanocrystalline glaze layer upon wear at 800 ℃ to minimize adhesive and oxidative wear.Our work uncovers a practical avenue for tailoring wear properties with multicomponent heterostructures over a wide temperature range.
查看更多>>摘要：Modern scleractinian corals are classified into robust,complex,and basal clades through comparative molecular studies.However,only few morphological or biological criteria can systematically determine the evolutionary trajectories of these major scleractinian coral clades.Here,we obtained the structural information of 21 scleractinian coral species representing robust and complex clades:High-resolution micro-computed tomography was used to reconstruct the polyp-canal systems in their colonies and to visualize the dynamic polyp growth processes.We found that the emergence of mesh-like canals may distinguish representatives of complex and robust clades.The differences in polyp-canal connections suggest distinct evolutionary trajectories among coral species:The formation of the canal network promoted the development of more complex coral structures,and coral polyps within this network formed calices of very similar volume,following precise axial growth directions.The influence of individual polyps on the coral colony becomes less significant as coral structures become more complex,and coral species with more complicated polyp-canal systems occupied niches more efficiently.This work supplements current evolutionary studies on reef-building corals,providing insight for further studies on coral growth patterns.
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