查看更多>>摘要：The development of self-powered flexible multicolor electrochromic(EC)systems that could switch different color without an external power supply has remained extremely challenging.Here,a new trilayer film structure for achieving self-powered flexible multicolor EC displays based on self-charging/discharging mechanism is proposed,which is simply assembled by sandwiching an ionic gel film between 2 cathodic nickel hexacyanoferrate(NiHCF)and Prussian blue(PB)nanoparticle films on indium tin oxide substrates.The display exhibits independent self-powered color switching of NiHCF and PB films with fast responsive time and high reversibility by selectively connecting the Al wire as anodes with the 2 EC films.Multicolor switching is thus achieved through a color overlay effect by superimposing the 2 EC films,including green,blue,yellow,and colorless.The bleaching/coloration process of the displays is driven by the discharging/self-charging mechanism for NiHCF and PB films,respectively,ensuring the self-powered color switching of the displays reversibly without an external power supply.It is further demonstrated that patterns can be easily created in the self-powered EC displays by the spray-coating method,allowing multicolor changing to convey specific information.Moreover,a self-powered ionic writing board is demonstrated based on the self-powered EC displays that can be repeatedly written freehand without the need of an external power source.We believe that the design concept may provide new insights into the development of self-powered flexible multicolor EC displays with self-recovered energy for widespread applications.
查看更多>>摘要：Epilepsy severely impairs the cognitive behavior of patients.It remains unclear whether epilepsy-induced cognitive impairment is associated with neuronal activities in the medial entorhinal cortex(MEC),a region known for its involvement in spatial cognition.To explore this neural mechanism,we recorded the spikes and local field potentials from MEC neurons in lithium-pilocarpine-induced epileptic rats using self-designed microelectrode arrays.Through the open field test,we identified spatial cells exhibiting spatially selective firing properties and assessed their spatial representations in relation to the progression of epilepsy.Meanwhile,we analyzed theta oscillations and theta modulation in both excitatory and inhibitory neurons.Furthermore,we used a novel object recognition test to evaluate changes in spatial cognitive ability of epileptic rats.After the epilepsy modeling,the spatial tuning of various types of spatial cells had suffered a rapid and pronounced damage during the latent period(1 to 5 d).Subsequently,the firing characteristics and theta oscillations were impaired.In the chronic period(＞10 d),the performance in the novel object experiment deteriorated.In conclusion,our study demonstrates the detrimental effect on spatial representations and electrophysiological properties of MEC neurons in the epileptic latency,suggesting the potential use of these changes as a"functional biomarker"for predicting cognitive impairment caused by epilepsy.
查看更多>>摘要：Acoustically actuated magnetoelectric(ME)antenna based on the efficient oscillation of magnetic dipoles has recently been considered as a promising solution for portable very-low-frequency communications.However,the severe nonlinear dynamic behavior in the case of strong-field excitation results in insufficient radiation capability and poor communication performance for a conventional ME antenna.In this work,we propose to suppress the nonlinearity of an ME antenna by neutralizing the spring-hardening effect in amorphous Metglas and the spring-softening effect in piezoelectric ceramics through an ME multilayered transmitter(ME-MLTx)design.With a driving voltage of 50 Vpp at the resonance frequency of 21.2 kHz,a magnetic flux density as high as 108 fT at a distance of 100 m is produced from a single ME-MLTx.In addition,ME-MLTx performs a decreased mechanical quality factor(Qm)less than 40.65,and,thus,a broadened bandwidth of 500 Hz is generated.Finally,a communication link transmitting binary American Standard Code for Information Interchange-coded message is built,which allows for an error-free communication with a distance of 18 m and a data rate of 300 bit/s in the presence of heavy environment noise.The communication distance can be further estimated over 100 m when using a femtotesla-class-inductive magnetic field receiver.The obtained results are believed to bring ME antennas one step closer to being applicable in very-low-frequency communications.
查看更多>>摘要：The clinical efficacy of implanted biomaterials is often compromised by host immune recognition and subsequent foreign body responses(FBRs).During the implantation,biomaterials inevitably come into direct contact with the blood,absorbing blood protein and forming blood clot.Many studies have been carried out to regulate protein adsorption,thus manipulating FBR.However,the role of clot surface fibrin films formed by clotting shrinkage in host reactions and FBR is often ignored.Because of the principle of fibrin film formation being relevant to fibrinogen or clotting factor absorption,it is feasible to manipulate the fibrin film formation via tuning the absorption of fibrinogen and clotting factor.As biological hydroxyapatite reserved bone architecture and microporous structure,the smaller particle size may expose more microporous structures and adsorb more fibrinogen or clotting factor.Therefore,we set up 3 sizes(small,＜0.2 mm;medium,1 to 2 mm;large,3 to 4 mm)of biological hydroxyapatite(porcine bone-derived hydroxyapatite)with different microporous structures to investigate the absorption of blood protein,the formation of clot surface fibrin films,and the subsequent FBR.We found that small group adsorbed more clotting factors because of more microporous structures and formed the thinnest and sparsest fibrin films.These thinnest and sparsest fibrin films increased inflammation and profibrosis of macrophages through a potential signaling pathway of cell adhesion-cytoskeleton-autophagy,leading to the stronger FBR.Large group adsorbed lesser clotting factors,forming the thickest and densest fibrin films,easing inflammation and profibrosis of macrophages,and finally mitigating FBR.Thus,this study deepens the understanding of the role of fibrin films in host recognition and FBR and demonstrates the feasibility of a strategy to regulate FBR by modulating fibrin films via tuning the absorption of blood proteins.
查看更多>>摘要：As extensively distributed tissues throughout the human body,glands play a critical role in various physiological processes.Therefore,the construction of biomimetic gland models in vitro has aroused great interest in multiple disciplines.In the biological field,the researchers focus on optimizing the cell sources and culture techniques to reconstruct the specific structures and functions of glands,such as the emergence of organoid technology.From the perspective of biomedical engineering,the generation of biomimetic gland models depends on the combination of engineered scaffolds and microfluidics,to mimic the in vivo environment of glandular tissues.These engineered stratagems endowed gland models with more biomimetic features,as well as a wide range of application prospects.In this review,we first describe the biomimetic strategies for constructing different in vitro gland models,focusing on the role of microfluidics in promoting the structure and function development of biomimetic glands.After summarizing several common in vitro models of endocrine and exocrine glands,the applications of gland models in disease modelling,drug screening,regenerative medicine,and personalized medicine are enumerated.Finally,we conclude the current challenges and our perspective of these biomimetic gland models.
查看更多>>摘要：Insufficient sleep can produce a multitude of deleterious repercussions on various domains of human well-being.Concomitantly,the walnut(Juglans mandshurica)confers numerous salutary biological activities pertaining to sleep.Nevertheless,the sedative and hypnotic capacities of walnut's functional constituents remain obscure.In this investigation,we analyzed the sedative and hypnotic components of the walnut Diaphragmajuglandis fructus and innovatively discovered a compound,defined as 3-hydroxy-4-iminobutyric acid(HI BA),which disrupts motor activity and enhances sleep duration by regulating the neurotransmitters(GABA,DA,etc.)within the brain and serum of mice.Subsequently,a metabolomics approach of the serum,basal ganglia,hypothalamus,and hippocampus as well as the gut microbiota was undertaken to unravel the underlying molecular mechanisms of sleep promotion.Our data reveal that HIBA can regulate the metabolism of basal ganglia(sphingolipids,acylcarnitines,etc.),possibly in relation to HIBA's influence on the gut microbiome(Muribaculum,Bacteroides,Lactobacillus,etc.).Therefore,we introduce a novel natural product,HIBA,and explicate the modulation of sleep promotion in mice based on the microbiota-gut-brain axis.This study contributes fresh insights toward natural product-based sleep research.
查看更多>>摘要：Spatially resolved transcriptomics(SRT)is capable of comprehensively characterizing gene expression patterns and providing an unbiased image of spatial composition.To fully understand the organizational complexity and tumor immune escape mechanism,we propose stMGATF,a multiview graph attention fusion model that integrates gene expression,histological images,spatial location,and gene association.To better extract information,stMGATF exploits SimCLRv2 for visual feature exaction and employs edge feature enhanced graph attention networks for the learning potential embedding of each view.A global attention mechanism is used to adaptively integrate 3 views to obtain low-dimensional representation.Applied to diverse SRT datasets,stMGATF is robust and outperforms other methods in detecting spatial domains and denoising data even with different resolutions and platforms.In particular,stMGATF contributes to the elucidation of tissue heterogeneity and extraction of 3-dimensional expression domains.Importantly,considering the associations between genes in tumors,stMGATF can identify the spatial dark genes ignored by traditional methods,which can be used to predict tumor-driving transcription factors and reveal tumor immune escape mechanisms,providing theoretical evidence for the development of new immunotherapeutic strategies.
查看更多>>摘要：Asia stands out as a priority for urgent biodiversity conservation due to its large protected areas(PAs)and threatened species.Since the 21st century,both the highlands and lowlands of Asia have been experiencing the dramatic human expansion.However,the threat degree of human expansion to biodiversity is poorly understood.Here,the threat degree of human expansion to biodiversity over 2000 to 2020 in Asia at the continental(Asia),national(48 Asian countries),and hotspot(6,502 Asian terrestrial PAs established before 2000)scales is investigated by integrating multiple large-scale data.The results show that human expansion poses widespread threat to biodiversity in Asia,especially in Southeast Asia,with Malaysia,Cambodia,and Vietnam having the largest threat degrees(～1.5 to 1.7 times of the Asian average level).Human expansion in highlands induces higher threats to biodiversity than that in lowlands in one-third Asian countries(most Southeast Asian countries).The regions with threats to biodiversity are present in～75％terrestrial PAs(including 4,866 PAs in 26 countries),and human expansion in PAs triggers higher threat degrees to biodiversity than that in non-PAs.Our findings provide novel insight for the Sustainable Development Goal 15(SDG-15 Life on Land)and suggest that human expansion in Southeast Asian countries and PAs might hinder the realization of SDG-15.To reduce the threat degree,Asian developing countries should accelerate economic transformation,and the developed countries in the world should reduce the demands for commodity trade in Southeast Asian countries(i.e.,trade leading to the loss of wildlife habitats)to alleviate human expansion,especially in PAs and highlands.
查看更多>>摘要：Tumor cells progressively remodel cytoskeletal structures and reduce cellular stiffness during tumor progression,implicating the correlation between cell mechanics and malignancy.However,the roles of tumor cell cytoskeleton and the mechanics in tumor progression remain incompletely understood.We report that softening/stiffening tumor cells by targeting actomyosin promotes/suppresses self-renewal in vitro and tumorigenic potential in vivo.Weakening/strengthening actin cytoskeleton impairs/reinforces the interaction between adenomatous polyposis coli(APC)and β-catenin,which facilitates p-catenin nuclear/cytoplasmic localization.Nuclear β-catenin binds to the promoter of Oct4,which enhances its transcription that is crucial in sustaining self-renewal and malignancy.These results demonstrate that the mechanics of tumor cells dictate self-renewal through cytoskeleton-APC-Wnt/β-catenin-Oct4 signaling,which are correlated with tumor differentiation and patient survival.This study unveils an uncovered regulatory role of cell mechanics in self-renewal and malignancy,and identifies tumor cell mechanics as a hallmark not only for cancer diagnosis but also for mechanotargeting.
查看更多>>摘要：Introducing and stabilizing oxygen vacancies in oxide catalysts is considered to be a promising strategy for improving catalytic activity and durability.Herein,we quantitatively create oxygen vacancies in the lattice of porous single-crystalline β-Ga2O3 monoliths by reduction treatments and stabilize them through the long-range ordering of crystal lattice to enhance catalytic activity and durability.The combination analysis of time-of-flight neutron powder diffraction and extended x-ray absorption fine structure discloses that the preferential generation of oxygen vacancy tends to occur at the site of tetrahedral coordination oxygen ions(OⅢ sites),which contributes to the formation of unsaturated Ga-O coordination in the monoclinic phase.The oxygen vacancies are randomly distributed in lattice even though some of them are present in the form of domain defect in the PSC Ga2O3 monoliths after the reduction treatment.The number of oxygen vacancies in the reduced monoliths gives 2.32 x 1013,2.87 x 1013,and 3.45 x 1013 mg-1 for the Ga2O2.952,Ga2O2.895,and Ga2O2.880,respectively.We therefore demonstrate the exceptionally high C2H4 selectivity of～100％at the C2H6 conversion of～37％for nonoxidative dehydrogenation of C2H6 to C2H4.We further demonstrate the excellent durability even at 620 ℃ for 240 h of continuous operation.
NETL
NSTL
万方数据