A vision chip with complementary pathways for open-world sensing.

Image sensors face substantial challenges when dealing with dynamic, diverse and unpredictable scenes in open-world applications. However, the development of image sensors towards high speed, high resolution, large dynamic range and high precision is limited by power and bandwidth. Here we present a complementary sensing paradigm inspired by the human visual system that involves parsing visual information into primitive-based representations and assembling these primitives to form two complementary vision pathways: a cognition-oriented pathway for accurate cognition and an action-oriented pathway for rapid response. To realize this paradigm, a vision chip called Tianmouc is developed, incorporating a hybrid pixel array and a parallel-and-heterogeneous readout architecture. Leveraging the characteristics of the complementary vision pathway, Tianmouc achieves high-speed sensing of up to 10,000 fps, a dynamic range of 130 dB and an advanced figure of merit in terms of spatial resolution, speed and dynamic range. Furthermore, it adaptively reduces bandwidth by 90%. We demonstrate the integration of a Tianmouc chip into an autonomous driving system, showcasing its abilities to enable accurate, fast and robust perception, even in challenging corner cases on open roads. The primitive-based complementary sensing paradigm helps in overcoming fundamental limitations in developing vision systems for diverse open-world applications.

Superatomic Aromaticity in Cyclic Superatomic Molecules: Ligand-Protected Penta-Icosahedral [M@Au11]5 (M = Au, Pt) Clusters.

Pure or doped gold icosahedra, which can be generally viewed as superatoms, are promising candidates for cluster-assembled structures. As the first large-scale ring-like gold cluster, the report of [Au60Se2(Ph3P)10(SeR)15]+ has arisen much interest, where its Au60 core is composed of five vertex-sharing gold icosahedra in a cyclic way. From electronic characters, this Au60 core is a 40e cyclic penta-superatom network formed by five 8e closed-shell superatoms (S2P6). When more valence electrons are introduced into the penta-superatom network by atomic doping, global delocalized bonds are induced in its bonding framework. In the 42e Au60 core of the [Au60Se2Cl15]- cluster, two extra electrons occupy one delocalized π-bonding orbital formed by super D orbitals of five superatoms, resulting in superatomic π aromaticity. In the 46e [Pt@Au11]5 core of [(Pt@Au11)5Ga2Cl15] cluster, three delocalized super-π bonds are formed, which are organized in the similar way as the aromatic C5H5- molecule. The unveiling of superatomic aromaticity promotes our understanding of the stability of cyclic superatom assemblies and extends the family of superatomic bonding patterns.

Unconventional Polarization-Switching Mechanism in (Hf, Zr)O_{2} Ferroelectrics and Its Implications.

HfO_{2}-based ferroelectric thin films are promising for their application in ferroelectric devices. Predicting the ultimate magnitude of polarization and understanding its switching mechanism are critical to realize the optimal performance of these devices. Here, a generalized solid-state variable cell nudged elastic band method is employed to predict the switching pathway associated with domain-wall motion in (Hf,Zr)O_{2} ferroelectrics. It is found that the polarization reversal pathway, where threefold coordinated O atoms pass across the nominal unit-cell boundaries defined by the Hf/Zr atomic planes, is energetically more favorable than the conventional pathway where the O atoms do not pass through these planes. This finding implies that the polarization orientation in the orthorhombic Pca2_{1} phase of HfO_{2} and its derivatives is opposite to that normally assumed, predicts the spontaneous polarization magnitude of about 70 µC/cm^{2} that is nearly 50% larger than the commonly accepted value, signifies a positive intrinsic longitudinal piezoelectric coefficient, and suggests growth of ferroelectric domains, in response to an applied electric field, structurally reversed to those usually anticipated. These results provide important insights into the understanding of ferroelectricity in HfO_{2}-based ferroelectrics.

Enhanced electromagnon excitations in Nd-doped BiFeO3 nanoparticles near morphotropic phase boundaries.

In multiferroics, electromagnons have been recognized as a noticeable topic due to their indispensable role in magnetoelectric, magnetodielectric, and magnetocapacitance effects. Here, the electromagnons of Bi1-xNdxFeO3 (x = 0-0.2) nanoparticles are studied via terahertz time-domain spectroscopy, and the impacts of doping concentrations on electromagnons have been discussed. We found that the electromagnons in Bi1-xNdxFeO3 nanoparticles are associated with their phase transition. The total coupling weight of electromagnons is gradually increased in polar R3c structures and then reduces in the antipolar Pbam phase, and the weight in the antipolar phase is less than that of the pure R3c phase. Interestingly, a colossal electromagnon is observed at polar-antipolar and antiferromagnetic-ferromagnetic phase boundaries. Our work offers an avenue for designing and choosing materials with better magnetodielectric and magnetocapacitance properties.

Osteosarcoma metastasis: prospective role of ezrin.

Osteosarcoma is the most commonly diagnosed primary malignant bone tumor, with similar global incidence rate across childhood and adolescence. Patients with localized disease have a 5-year survival period of 80 %; however, the prognosis is poor in those with metastatic osteosarcoma. The origin of the primary tumor is most frequently the metaphyseal (actively growing) regions of the distal femur, proximal tibia, and proximal humerus, although the tumor can develop in any bone, and the most likely sites for metastasis are the lungs and bone. Ezrin is a member of the ezrin-radixin-moesin (ERM) family of proteins that functions as a cross-linker between the actin cytoskeleton and the plasma membrane, and ezrin also plays a positive role in maintaining cell shape and polarity and facilitates membrane-trafficking pathways, cell migration, cell signaling, growth regulation, and differentiation. There is strong evidence to suggest that ezrin is necessary for osteosarcoma metastasis. The objective of the current review is to summarize the know-how about metastatic progression in osteosarcoma, with a focus on ezrin. Despite the promise that preliminary studies on ezrin have shown, there is a great need to further analyze the role of ezrin in osteosarcoma metastasis and to determine its usefulness as a biomarker for the disease.

Iron fluoride hollow porous microspheres: facile solution-phase synthesis and their application for Li-ion battery cathodes.

Iron fluoride cathodes have been attracting considerable interest due to their high electromotive force value of 2.7 V and their high theoretical capacity of 237 mA h g(-1) (1 e(-) transfer). In this study, uniform iron fluoride hollow porous microspheres have been synthesized for the first time by using a facile and scalable solution-phase route. These uniform porous and hollow microspheres show a high specific capacity of 210 mA h g(-1) at 0.1 C, and excellent rate capability (100 mA h g(-1) at 1 C) between 1.7 and 4.5 V versus Li/Li(+) . When in the range of 1.3 to 4.5 V, stable capacity was achieved at 350 mA h g(-1) at a current of 50 mA g(-1) .

Enhancing the electrochemical performance of the LiMn(2)O(4) hollow microsphere cathode with a LiNi(0.5)Mn(1.5)O(4) coated layer.

Spinel cathode materials consisting of LiMn2 O4 @LiNi0.5 Mn1.5 O4 hollow microspheres have been synthesized by a facile solution-phase coating and subsequent solid-phase lithiation route in an atmosphere of air. When used as the cathode of lithium-ion batteries, the double-shell LiMn2 O4 @LiNi0.5 Mn1.5 O4 hollow microspheres thus obtained show a high specific capacity of 120 mA h g(-1) at 1 C rate, and excellent rate capability (90 mAhg(-1) at 10 C) over the range of 3.5-5 V versus Li/Li(+) with a retention of 95 % over 500 cycles.

Hydrogen-bond memory and water-skin supersolidity resolving the Mpemba paradox.

The Mpemba paradox, that is, hotter water freezes faster than colder water, has baffled thinkers like Francis Bacon, René Descartes, and Aristotle since B.C. 350. However, a commonly accepted understanding or theoretical reproduction of this effect remains challenging. Numerical reproduction of observations, shown herewith, confirms that water skin supersolidity [Zhang et al., Phys. Chem. Chem. Phys., DOI: ] enhances the local thermal diffusivity favoring heat flowing outwardly in the liquid path. Analysis of experimental database reveals that the hydrogen bond (O:H-O) possesses memory to emit energy at a rate depending on its initial storage. Unlike other usual materials that lengthen and soften all bonds when they absorb thermal energy, water performs abnormally under heating to lengthen the O:H nonbond and shorten the H-O covalent bond through inter-oxygen Coulomb coupling [Sun et al., J. Phys. Chem. Lett., 2013, 4, 3238]. Cooling does the opposite to release energy, like releasing a coupled pair of bungees, at a rate of history dependence. Being sensitive to the source volume, skin radiation, and the drain temperature, the Mpemba effect proceeds only in the strictly non-adiabatic 'source-path-drain' cycling system for the heat "emission-conduction-dissipation" dynamics with a relaxation time that drops exponentially with the rise of the initial temperature of the liquid source.

A common supersolid skin covering both water and ice.

Consistency in experimental observations, numerical calculations, and theoretical predictions have revealed that the skins of water and ice share the same attribute of supersolidity characterized by an identical H-O vibration frequency of 3450 cm(-1). Molecular undercoordination and inter-electron-pair repulsion shortens the H-O bond and lengthens the O:H nonbond, leading to a dual process of nonbonding electron polarization. This relaxation-polarization process enhances the dipole moment, elasticity, viscosity, and thermal stability of these skins with a 25% density loss, which is responsible for the hydrophobicity and toughness of the water skin and results in the slippery behavior of ice.

Neuromorphic Computing of Optoelectronic Artificial BFCO/AZO Heterostructure Memristors Synapses.

Compared with purely electrical neuromorphic devices, those stimulated by optical signals have gained increasing attention due to their realistic sensory simulation. In this work, an optoelectronic neuromorphic device based on a photoelectric memristor with a Bi2FeCrO6/Al-doped ZnO (BFCO/AZO) heterostructure is fabricated that can respond to both electrical and optical signals and successfully simulate a variety of synaptic behaviors, such as STP, LTP, and PPF. In addition, the photomemory mechanism was identified by analyzing the energy band structures of AZO and BFCO. A convolutional neural network (CNN) architecture for pattern classification at the Mixed National Institute of Standards and Technology (MNIST) was used and improved the recognition accuracy of the MNIST and Fashion-MNIST datasets to 95.21% and 74.19%, respectively, by implementing an improved stochastic adaptive algorithm. These results provide a feasible approach for future implementation of optoelectronic synapses.

An adjustable multistage resistance switching behavior of a photoelectric artificial synaptic device with a ferroelectric diode effect for neuromorphic computing.

Neuromorphic computing, which mimics biological neural networks, is widely regarded as the optimal solution for addressing the limitations of traditional von Neumann computing architecture. In this work, an adjustable multistage resistance switching ferroelectric Bi2FeCrO6 diode artificial synaptic device was fabricated using a sol-gel method with a simple process. The device exhibits nonlinearity in its electrical characteristics, demonstrating tunable multistage resistance switching behavior and a strong ferroelectric diode effect through the manipulation of ferroelectric polarization. One of its salient advantages resides in its capacity to dynamically regulate its polarization state in response to an external electric field, thereby facilitating the fine-tuning of synaptic connection strength while maintaining synaptic stability. The device is capable of accurately simulating the fundamental properties of biological synapses, including long/short-term plasticity, paired-pulse facilitation, and spike-timing-dependent plasticity. Additionally, the device exhibits a distinctive photoelectric response and is capable of inducing synaptic plasticity by light signal activation. The utilization of a femtosecond laser for the scrutiny of carrier transport mechanisms imparts profound insights into the intricate dynamics governing the optical memory effect. Furthermore, utilizing a convolutional neural network (CNN) architecture, the recognition accuracy of the MNIST and fashion MNIST datasets was improved to 95.6% and 78%, respectively, through the implementation of improved random adaptive algorithms. These findings present a new opportunity for utilizing Bi2FeCrO6 materials in the development of artificial synapses for neuromorphic computation.

New-Style Logic Operation and Neuromorphic Computing Enabled by Optoelectronic Artificial Synapses in an MXene/Y:HfO2 Ferroelectric Memristor.

Today's computing systems, to meet the enormous demands of information processing, have driven the development of brain-inspired neuromorphic systems. However, there are relatively few optoelectronic devices in most brain-inspired neuromorphic systems that can simultaneously regulate the conductivity through both optical and electrical signals. In this work, the Au/MXene/Y:HfO2/FTO ferroelectric memristor as an optoelectronic artificial synaptic device exhibited both digital and analog resistance switching (RS) behaviors under different voltages with a good switching ratio (>103). Under optoelectronic conditions, optimal weight update parameters and an enhanced algorithm achieved 97.1% recognition accuracy in convolutional neural networks. A new logic gate circuit specifically designed for optoelectronic inputs was established. Furthermore, the device integrates the impact of relative humidity to develop an innovative three-person voting mechanism with a veto power. These results provide a feasible approach for integrating optoelectronic artificial synapses with logic-based computing devices.

Facile synthesis of transition-metal oxide nanocrystals embedded in hollow carbon microspheres for high-rate lithium-ion-battery anodes.

Charged up: A general soft-template route for the synthesis of uniform hollow carbon microspheres embedded with transition-metal oxide nanocrystals (OHCMs) has been developed (see figure). The obtained OHCMs possess a microsized spherical shape, embedded transition-metal oxide nanocrystals, and fully encapsulating conductive carbon shells, which endow the resulting anode materials with high specific capacities, rate capabilities, electrode densities, and cycle stabilities.

From chemistry to mechanics: bulk modulus evolution of Li-Si and Li-Sn alloys via the metallic electronegativity scale.

Toward engineering high performance anode alloys for Li-ion batteries, we proposed a useful method to quantitatively estimate the bulk modulus of binary alloys in terms of metallic electronegativity (EN), alloy composition and formula volume. On the basis of our proposed potential viewpoint, EN as a fundamental chemistry concept can be extended to be an important physical parameter to characterize the mechanical performance of Li-Si and Li-Sn alloys as anode materials for Li-ion batteries. The bulk modulus of binary alloys is linearly proportional to the combination of average metallic EN and atomic density of alloys. We calculated the bulk moduli of Li-Si and Li-Sn alloys with different Li concentrations, which can agree well with the reported data. The bulk modulus of Li-Si and Li-Sn alloys decreases with increasing Li concentration, leading to the elastic softening of the alloys, which is essentially caused by the decreased strength of constituent chemical bonds in alloys from the viewpoint of EN. This work provides a deep understanding of mechanical failure of Si and Sn anodes for Li-ion batteries, and permits the prediction of the composition dependent bulk modulus of various lithiated alloys on the basis of chemical formula, metallic EN and cell volume (or alloy density), with no structural details required.

HfO2-based ferroelectric thin film and memory device applications in the post-Moore era: A review.

The rapid development of 5G, big data, and Internet of Things (IoT) technologies is urgently required for novel non-volatile memory devices with low power consumption, fast read/write speed, and high reliability, which are crucial for high-performance computing. Ferroelectric memory has undergone extensive investigation as a viable alternative for commercial applications since the post-Moore era. However, conventional perovskite-structure ferroelectrics (e.g., PbZr x Ti1- x O3) encounter severe limitations for high-density integration owing to the size effect of ferroelectricity and incompatibility with complementary metal-oxide-semiconductor technology. Since 2011, the ferroelectric field has been primarily focused on HfO2-based ferroelectric thin films owing to their exceptional scalability. Several reviews discussing the control of ferroelectricity and device applications exist. It is believed that a comprehensive understanding of mechanisms based on industrial requirements and concerns is necessary, such as the wake-up effect and fatigue mechanism. These mechanisms reflect the atomic structures of the materials as well as the device physics. Herein, a review focusing on phase stability and domain structure is presented. In addition, the recent progress in related ferroelectric memory devices and their challenges is briefly discussed.

A critical appraisal of the nanoindentation creep 'nose' effect in Ni thin films.

The creep behaviour of polycrystal Ni thin films under the same maximum load (Pmax = 8000 microN) and different unloading periods (ranging from 1 to 250 s) has been investigated at room temperature using nanoindentation tests. A 'nose' has been observed in the unloading segment of the load-penetration depth curve when the holding time at peak load is short and/or the unloading rate is small, and when the peak load is sufficient high. When a 'nose' presents, the apparent unloading stiffness Su, defined as dP/dh, is negative, and the reduced modulus can no longer be calculated from the Oliver-Pharr method. Taking such uncertainties into account, a critical appraisal is proposed for ranking creep propensities exhibited during nanoindentation under specified conditions.

Superatomic Three-Center Bond in a Tri-Icosahedral Au36Ag2(SR)18 Cluster: Analogue of 3c-2e Bond in Molecules.

Probing the nature of electronic stability for ligand-protected gold clusters is important in gold chemistry. A thermally stable Au36Ag2(SR)18 nanocluster was synthesized recently. It has a D3h tri-icosahedral [Au30Ag2]12+ core with 20 valence electrons, which does not follow the magic number of gold superatoms. Herein, we propose a superatomic three-center bond to unveil its electronic stability. The [Au30Ag2]12+ core is viewed as a union of three face-fused superatoms, and chemical bonding analysis suggests a three-superatom-center two-electron (3sc-2e) bond for the octet rule of each superatom, which mimics the bonding framework of the D3h O32- molecule. Moreover, a liganded tri-icosahedral [Au27Pt3Ag2]11+ core with 18 valence electrons is predicted, and three 2sc-2e bonds are formed between each of two superatoms to satisfy the octet rule (analogue of D3h O3), indicating the flexibility of superatomic bonding. Such a superatomic three-center bond extends the community of superatomic bonding and gives a new perspective for superatom assembling.

Tri- and Tetra-superatomic Molecules in Ligand-Protected Face-Fused Icosahedral (M@Au12)n (M = Au, Pt, Ir, and Os, and n = 3 and 4) Clusters.

Cluster assembling has been one of the hottest topics in nanochemistry. In certain ligand-protected gold clusters, bi-icosahedral cores assembled from Au13 superatoms were found to be analogues of diatomic molecules F2, N2, and singlet O2, respectively, in electronic shells, depending upon the super valence bond (SVB) model. However, challenges still remain for extending the scale in cluster assembling via the SVB model. In this work, ligand-protected tri- and tetra-superatomic clusters composed of icosahedral M@Au12 (M = Au, Pt, Ir, and Os) units are theoretically predicted. These clusters are stable with reasonable highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps and proven to be analogues of simple triatomic (Cl3-, OCl2, O3, and CO2) and tetra-atomic (N≡C-C≡N, and Cl-C≡C-Cl) molecules in both geometric and electronic structures. Moreover, a stable cluster-assembling gold nanowire is predicted following the same rules. This work provides effective electronic rules for cluster assembling on a larger scale and gives references for their experimental synthesis.

Sodium Cationization Enables Exotic Deprotonation Sites on Gaseous Mononucleotides.

We report observation and photoelectron spectroscopic characterization of sodium cationization on four doubly deprotonated mononucleotide dianions Na+·[dNMP-2H]2- (N = A, G, C, or T) in the gas phase. Multiple tautomers with distinct deprotonated sites are identified, in which Na+ enables novel double deprotonation patterns and folds the resultant mononucleotide dianions. The most stable isomer for the whole family is derived from detaching one proton from the phosphate and the other from the nucleobase (amino group for N = A, G, and C, but nitrogen atom for T), whereas high-lying isomers with protons detached separately from the phosphate and the hydroxy group of sugar coexist. Particularly, an exotic deprotomer with both protons deprived from guanosine is populated as well. This work thus displays a remarkably diverse binding landscape enabled by sodium cationization, a potentially critical element in developing a general formulism to better model metal cation and nucleotide interactions.

MiR-328-5p inhibits the adipogenic differentiation of hMSCs by targeting fatty acid synthase.

INTRODUCTION: Adipogenesis, a highly coordinated process regulated by numerous effectors, is largely responsible for the quantity and size of adipocytes. Attenuation of adipocyte differentiation has been proposed as a viable technique for reducing obesity and its associated diseases. MicroRNAs play an important role in human bone marrow mesenchymal stem cells (hMSCs) adipogenic differentiation. However, there is a lack of clarity regarding the role of miR-328-5p in adipogenesis. MATERIAL AND METHODS: Using the lentiviral vectors to overexpress fatty acid synthase (FASN) and miR-328-5p, RT-qPCR and Western blotting were carried out to assess RNA expression and protein levels of FASN and adipogenic marker factors. Meanwhile, Oil red O staining and lipid quantification was performed to evaluate the accumulation of intracellular lipid droplets. Additionally, the validity of FASN as a potential target gene for miR-328-5p was carried out using a luciferase reporter assay. RESULTS: Our data showed that hMSCs adipogenic differentiation was associaed with the reduced miR-328-5p expression, while an elevated expression of the underlined miRNA attenuated adipogenesis and the expression of adipogenic marker genes. Luciferase reporter assay validated FASN as a target gene of miR-328-5p, and an elevated FASN expression reversed the anti-adipogenic effects of miR-328-5p. CONCLUSIONS: The results revealed that miR-328-5p inhibits hMSCs adipogenic differentiation by targeting FASN. These findings contribute to our understanding of obesity-related disease development.