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2,3-Indole-fused 1,4-diazocines represent a new family of indole alkaloid compounds and are difficult to access by the reported protocols. Herein, we report a copper-catalyzed decarboxylative cyclization of cyclic propargylic carbamates with imidazolidines via sequential C–N/C–N/C–C bond formation to deliver a series of 2,3-indole-fused 1,4-diazocines, with a broad substrate scope and mild conditions.

Resulting from the dense packing of subnanometer molecular clusters, molecular granular materials (MGMs) are shown to maintain high elasticity far above their apparent glass transition temperature (Tg*). However, our microscopic understanding of their structure–property relationship is still poor. Herein, 1 nm polyhedral oligomeric silsesquioxanes (POSSs) are appended to a backbone chain in a brush configuration with different flexible linker chains. Assemblies of these brush polymers exhibit hierarchical relaxation dynamics with the glass transition arising from the cooperative dynamics of packed POSSs. The interaction among the assemblies can be strengthened by increasing the rigidity of linkers with the MGM relaxation modes changing from colloid- to polymer chain-like behavior, rendering their tunable viscoelasticity. This finally contributes to the decoupling of mechanical and thermal properties by showing elasticity dominant mechanical properties at a temperature 150 K above the Tg*.

We report the surface modification of nanochannels whose channels are formed from stacked and overlapping graphene oxide sheets, in which the high density of nitrogen/oxygen groups and networks of H bonds serve as excellent proton channels but block the transport of cations such as Li+and Na+. The membrane has excellent stability when immersed for long periods under water and has an NaCl rejection rate of approximately 99% while maintaining permeability to water and performs well for at least 400 h for desalination. Our straightforward approach to achieving this type of two-dimensional channel material for selective ion conduction, efficient ion separation, and water desalination might open a host of possible new uses.

The structural chemistry of the solid ion-conducting LixLa2/3–x/3TiO3(LLTO) is rich with various polymorphs related to atomic segregation. We explored the LLTO reaction pathway from various structurally related precursors (La2LiO3H, Li2TiO3, and Li4Ti5O12), focusing on the effects of LLTO-like structural motifs in precursors using a combination of experimental and computational techniques. Density functional theory (DFT) calculations revealed that the failure of syntheses to produce LLTO below 1300 °C is due to the presence of multiple competing low-energy phases that result in competitive byproduct formation. In all syntheses where T= 1300 °C, LLTO was the sole product; however, varying phase fractions of I4/mcmand P4/nbmpolymorphs and double-perovskite P4/mmmcan be obtained depending on the synthesis route. This is an unusual result as at 1300 °C, LLTO should only be the ideal cubic Pm-3mperovskite structure, yet there appears to be a memory effect from the different precursors resulting in the unique phase selectivity and stabilization.

Pd1Au2MAs with the optimized egorbital occupancy of Pd achieve almost 100% of FE for CO from −0.40 VRHEto −0.80 VRHE, and the long-term stability for 20 h, providing an effective idea to design high-performance CO2electroreduction catalysts.

Perovskite oxynitrides (PONs) are a promising class of materials for applications ranging from catalysis to photovoltaics. However, the vast space of single PON materials (ABO3–xNx) has yet to be fully explored. Additionally, the community needs guidelines that relate PON chemistry and anion ordering to stability to better understand how to design PON materials that resist corrosion and decomposition under operating conditions. Screening this materials space requires identifying candidate PON materials that will be stable under operating conditions, which in turn requires methods to evaluate each material’s stability. Here, we predict the stability of single PON materials using a four-step approach based on density functional theory modeling: (i) enumerate viable cation pairs, (ii) select an energetically favorable prototypical anion ordering, (iii) compute each PON’s energy above the thermodynamic convex hull, and (iv) generate computational Pourbaix diagrams to determine allowable ranges of electrochemical operating conditions. A critical part of our approach is determining a prototypical stable anion ordering for both ABO2N and ABON2stoichiometries across a variety of A- and B-site cations. We demonstrate a stable anion ordering containing a high degree of cisordering between B cations and minority-composition anions. We predict 85 stable and 109 metastable PON compounds, with A ∈ {La, Pb, Nd, Sr, Ba, Ca} and B ∈ {Re, Os, Nb, Ta} forming cation pairs that lead to stable PONs less than 10 meV/atom above the thermodynamic convex hull. Computational Pourbaix diagrams for two stable candidates, CaReO2N and LaTaON2, suggest that not all compounds with zero energy above the thermodynamic convex hull can be easily synthesized.

Recently, there has been a surge of interest in applying memristors to hardware implementations of deep neural networks due to various desirable properties of the memristor, such as nonvolativity, multivalue, and nanosize. Most existing neural network circuit designs, however, are based on generic frameworks that are not optimized for memristors. Furthermore, to the best of our knowledge, there are no existing efficient memristor-based implementations of complex neural network operators, such as deconvolutions and squeeze-and-excitation (SE) blocks, which are critical for achieving high accuracy in common medical image analysis applications, such as semantic segmentation. This article proposes convolution-kernel first (CKF), an efficient scheme for designing memristor-based fully convolutional neural networks (FCNs). Compared with existing neural network circuits, CKF enables effective parameter pruning, which significantly reduces circuit power consumption. Furthermore, CKF includes the novel, memristor-optimized implementations of deconvolution layers and SE blocks. Simulation results on real medical image segmentation tasks confirm that CKF obtains up to 56.2% reduction in terms of computations and 33.62-W reduction in terms of power consumption in the circuit after weight pruning while retaining high accuracy on the test set. Moreover, the pruning results can be applied directly to existing circuits without any modification for the corresponding system. [ABSTRACT FROM AUTHOR]

The responses of wheat yield to large-scale atmospheric circulation indices (LACI) were explored in Henan province, north China. With using the annual series of climate-driven yield index (CDYI) extracted from winter wheat yield collected in 17 cites and the monthly series of 15 types of LACI during 1988–2017, the main findings were as follows: (1) this province could be divided into four sub-regions (central-east, west, north, and south Henan) with different CDYI variations; (2) the CDYI in central-east, west, south Henan was dominated by a 3-year oscillation, while the CDYI in north Henan presented a notable 7.5-year oscillation; (3) among the four sub-regions, central-east Henan had the most significant CDYI-LACI relationship, and the higher Nino 1?+?2 in December were a key yield reduction signal; (4) during 2008–2017, the stronger increase of Nino1?+?2_in December had caused the yield decrease in central Henan by 6.58%. In summary, linking wheat yield to LACI anomalies should be instrumental in alleviating the adverse effects of climate change on wheat production.

Elasticity and stability play a crucial role in phase change fibers (PCFs), ensuring both comfort and effective thermal management in fabrics. In this study, we present the development of an elastic and shape-stable phase change fiber through coaxial wet spinning. The fiber consists of a paraffin wax (PW) core encapsulated in a thermoplastic polyurethane (TPU) sheath, providing reliable protection against leakage during use. The obtained PCFs exhibit a PW loading capacity of up to 64.9 wt% and a heating enthalpy of 117.0 J/g. Notably, these fibers maintain their morphological and thermal stability even after undergoing 50 cycles of heating and cooling treatments. By integrating the PCFs into a fabric and coating the surface with CNTs, the PCFs-based fabric achieves an outstanding photothermal conversion efficiency of 95.1 % under a light intensity of 250 mW/cm2and an electrothermal conversion efficiency of 73.2 % at a power level of 0.9 W. Furthermore, the fabric, woven with uniformly broken PW core, exhibits excellent tensile resilience in various conditions, including room temperature and during photothermal and electrothermal conversion processes. This study introduces a promising avenue for the development of innovative PCFs, offering significant potential for their application in the realm of personal smart fabrics, particularly in the field of advanced thermal management.

Silica-filled rubber composite is the main component of the “green tire” featured with a high fuel economy. Nowadays, incorporating sulfur-containing silane coupling agents (SSCAs) to improve the compatibility between silica and rubber is essential to optimizing the comprehensive properties of the resultant composites. However, SSCA synthesis requires multistep procedures and organic solvents and many intractable issues, such as low modification efficiency and volatile organic compound (VOC) emissions, cannot be resolved with regard to the use of SSCAs. Herein, we presented the facile synthesis of an epoxy-engineered polysulfide (SPVE) via inverse vulcanization of styrene, 1,2-epoxy-4-vinylcyclohexane, and sulfur and utilized it as a new-brand modifier for silica-filled rubber composite. The coupling mechanism of SPVE is revealed. Specifically, the polysulfides of SPVE can graft onto rubber chains; meanwhile, the epoxy groups of SPVE readily react with silanol groups on the silica surface, creating molecular linkages between rubber and silica. Consequently, incorporating SPVE remarkably improves silica dispersion and enhances the interfacial adhesion of the composites, thereby leading to superior mechanical properties and significantly decreased hysteresis loss. Compared with the commonly used SSCA, bis[3-(triethoxysilyl)propyl] tetrasulfide, SPVE exhibits a higher coupling efficiency without VOC emissions, providing an environmentally friendly solution for the manufacture of energy-saving tires.

Electrochemically converting carbon dioxide (CO2) into valuable fuels and renewable chemical feedstocks is considered a highly promising approach to achieve carbon neutrality. In this work, a robust interfacial built-in electric field (BEF) has been successfully designed and created in Bi/Bi2Te3nanowires (NWs). The Bi/Bi2Te3NWs consistently maintain over 90% Faradaic efficiency (FE) within a wide potential range (−0.8 to −1.2 V), with HCOOH selectivity reaching 97.2% at −1.0 V. Moreover, the FEHCOOHof Bi/Bi2Te3NWs can still reach 94.3% at a current density of 100 mA cm–2when it is used as a cathode electrocatalyst in a flow-cell system. Detailed in situexperiments confirm that the presence of interfacial BEF between Bi and Bi/Bi2Te3promotes the formation of *OHCO intermediates, thus facilitating the production of HCOOH species. DFT calculations show that Bi/Bi2Te3NWs increase the formation energies of H* and *COOH while reducing the energy barrier for *OCHO formation, thus achieving a bidirectional optimization of intermediate adsorption. This work provides a feasible scheme for exploring electrocatalytic reaction intermediates by using the BEF strategy.

Elucidating the structure–activity relationships between biomolecules and hydroxyapatite (HAP) is essential to understand bone mineralization mechanisms, develop HAP-based implants, and design drug delivery vectors. Here, four peptides identified by phage display were selected as model HAP-binding peptides (HBPs) to examine the effects of primary amino acid sequence, phosphorylation of serine, presence of charged amino acid residues, and net charge of the peptide on (1) HAP-binding affinity, (2) secondary conformation, and (3) HAP nucleation and crystal growth. Binding affinities were determined by obtaining adsorption isotherms by mass depletion, and the conformations of the peptides in solution and bound states were observed by circular dichroism. Results showed that the magnitude of the net charge primarily controlled binding affinity, with little dependence on the other HBP features. The binding affinity and conformation results were in good agreement with our previous molecular dynamics simulation results, thus providing an excellent benchmark for the simulations. Transmission electron microscopy was used to explore the effect of these HBPs on calcium phosphate (Ca-PO4) nucleation and growth. Results indicated that HBPs may inhibit nucleation of Ca-PO4nanoparticles and their phase transition to crystalline HAP, as well as control crystal growth rates in specific crystallographic directions, thus changing the classical needle-like morphology of inorganically grown HAP crystals to a biomimetic plate-like morphology.

Flight, an active fear response to imminent threat, is dependent on the rapid risk assessment of sensory information processed by the cortex. The thalamic reticular nucleus (TRN) filters information between the cortex and the thalamus, but whether it participates in the regulation of flight behavior remains largely unknown. Here, we report that activation of parvalbumin-expressing neurons in the limbic TRN, but not those in the sensory TRN, mediates flight. Glutamatergic inputs from the cingulate cortex (Cg) selectively activate the limbic TRN, which in turn inhibits the intermediodorsal thalamic nucleus (IMD). Activation of this Cg→limbic TRN→IMD circuit results in inhibition of the IMD and produces flight behavior. Conversely, removal of inhibition onto the IMD results in more freezing and less flight, suggesting that the IMD may function as a pro-freeze center. Overall, these findings reveal a novel corticothalamic circuit through the TRN that controls the flight response. Dong, Wang et al. uncover a circuit linking Glu+cingulate inputs→PV+neurons in the limbic thalamic reticular nucleus→intermediodorsal thalamic nucleus, and show that this cortico-intrathalamic circuit is a component of the fear circuitry and controls flight behavior in mice.

Deliberate design of advantageous nanostructures holds great promise for developing high-performance electrode materials for electrochemical energy storage. However, it remains a tremendous challenge to simultaneously gain high gravimetric, areal, and volumetric capacities as well as high rate performance and cyclability to meet practical requirements mainly due to the intractable insufficient ion diffusion and limited active sites for dense electrodes with high areal mass loadings. Herein we report a double-holey-heterostructure framework, in which holey Fe2O3nanosheets (H-Fe2O3) are tightly and conformably grown on the holey reduced graphene oxide (H-RGO). This hierarchical nanostructure allows for rapid ion and electron transport and sufficient utilization of active sites throughout a highly compact and thick electrode. Therefore, the free-standing flexible H-Fe2O3/H-RGO heterostructure anode can simultaneously deliver ultrahigh gravimetric, areal, and volumetric capacities of 1524 mAh g–1, 4.72 mAh cm–2, and 2621 mAh cm–3, respectively, at 0.2 A g–1after 120 cycles, and extraordinary rate performance with a capacity of 487 mAh g–1(1.51 mAh cm–2) at a high current density of 30 A g–1(93 mA cm–2) as well as excellent cycling stability with a capacity retention of 96.3% after 1600 cycles, which has rarely been achieved before.

High-resolution three-dimensional biomolecule distribution information of large samples is essential to understanding their biological structure and function. Here, we proposed a method combining large sample resin embedding with iDISCO immunofluorescence staining to acquire the profile of biomolecules with high spatial resolution. We evaluated the compatibility of plastic embedding with an iDISCO staining technique and found that the fluorophores and the neuronal fine structures could be well preserved in the Lowicryl HM20 resin, and that numerous antibodies and fluorescent tracers worked well upon Lowicryl HM20 resin embedding. Further, using fluorescence Micro-Optical sectioning tomography (fMOST) technology combined with ultra-thin slicing and imaging, we were able to image the immunolabeled large-volume tissues with high resolution.

The bimetallic Au–Cu alloy nanoparticles have been constructed in electrospun carbon nanofibers (Au–Cu/CNFs), employing as high efficient hydrogen evolution reaction (HER) electrode. The morphology, structure, and composition of bimetallic Au–Cu alloy can be controlled by adjusting the precursor nanofibers through a facile approach. With the increased Cu content, the Au–Cu alloy have a transition from the homogeneous AuCu3alloy phase to the Au3Cu phase with Cu shell. The self-supported bimetallic Au–Cu/CNFs hybrid can be directly employed as electrode materials for water splitting, and it showed excellent electrochemical activity, including long-term stability, high exchange current density, and low overpotential. The outstanding HER performance could be mainly attributed to the synergistic interactions and interfacial effects of Au–Cu alloy with high densities of uncoordinated surface atoms. In addition, the fast charge transport and the fast kinetic for the desorption of the gas were originated from the self-supported three-dimensional architectures consist of integrated Au–Cu/CNFs networks. The Au–Cu/CNFs with mass ratio of 1:2 (Au3Cu–Cu “core-shell” alloy) obtain the lowest overpotential of 83 mV (at j= 10 mA cm–2), lowest Tafel slope of 70 mV dec–1, and highest exchange current density of 0.790 mA cm–2. The present investigations offer a new strategy for the design and synthesis of unique nanocrystals in energy conversion related application.

Amino acid surfactants have gained significant importance in overcoming the limitations of conventional surfactants, notably, their low biocompatibility and biodegradability. However, the current amino acid surfactants lack multifunctional properties due to the nonreactivity of their aliphatic chains, necessitating the development of a new type of amino acid surfactant. A novel melanin-like amino acid surfactant and a biomimetic synthesis route were devised by mimicking the biosynthesis of melanin. Renewable natural polyphenol compounds with catechol moieties were utilized as building blocks for the hydrophobic group. In a proof-of-concept experiment, ethyl protocatechuate was oxidized to o-quinone and subsequently covalently linked to the amino group of lysine via Michael addition. The chemical structure was verified using liquid chromatography–tandem mass spectroscopy. The melanin-like amino acid surfactant exhibited excellent surface-active properties, with a critical micelle concentration of 1.59 mN m–1. Furthermore, it demonstrated remarkable emulsifying, foaming, solubilizing, dispersing, and wetting capabilities. Notably, it also possessed multifunctionality, including antibacterial activity, antioxidant activity, robustness, and mildness. These outstanding properties indicate significant potential for various applications. This strategy offers innovative insights and a versatile, modular toolbox for synthesizing multifunctional amino acid surfactants that mimic melanin. The approach allows for the easy interchange of o-quinone building blocks, which is akin to snap jewelry.

Neuropathic pain and bladder dysfunction represent significant quality-of-life issues for many spinal cord injury patients. Loss of GABAergic tone in the injured spinal cord may contribute to the emergence of these symptoms. Previous studies have shown that transplantation of rodent inhibitory interneuron precursors from the medial ganglionic eminence (MGE) enhances GABAergic signaling in the brain and spinal cord. Here we look at whether transplanted MGE-like cells derived from human embryonic stem cells (hESC-MGEs) can mitigate the pathological effects of spinal cord injury. We find that 6 months after transplantation into injured mouse spinal cords, hESC-MGEs differentiate into GABAergic neuron subtypes and receive synaptic inputs, suggesting functional integration into host spinal cord. Moreover, the transplanted animals show improved bladder function and mitigation of pain-related symptoms. Our results therefore suggest that this approach may be a valuable strategy for ameliorating the adverse effects of spinal cord injury.

The search for non-noble metal catalysts with high activity for the hydrogen evolution reaction (HER) is crucial for efficient hydrogen production at low cost and on a large scale. Herein, we report a novel WO3–xcatalyst synthesized on carbon nanofiber mats (CFMs) by electrospinning and followed by a carbonization process in a tubal furnace. The morphology and composition of the catalysts were tailored via a simple method, and the hybrid catalyst mats were used directly as cathodes to investigate their HER performance. Notably, the as-prepared catalysts exhibit substantially enhanced activity for the HER, demonstrating a small overpotential, a high exchange current density, and a large cathodic current density. The remarkable electrocatalytic performances result from the poor crystallinity of WO3–x, the high electrical conductivity of WO3–x, and the use of electrospun CNFs. The present work outlines a straightforward approach for the synthesis of transition metal oxide (TMO)-based carbon nanofiber mats with promising applications for the HER.

The ventricular-subventricular zone (V-SVZ) is an extensive germinal niche containing neural stem cells (NSCs) in the walls of the lateral ventricles of the adult brain. How the adult brain’s neural activity influences the behavior of adult NSCs remains largely unknown. We show that serotonergic (5HT) axons originating from a small group of neurons in the raphe form an extensive plexus on most of the ventricular walls. Electron microscopy revealed intimate contacts between 5HT axons and NSCs (B1) or ependymal cells (E1) and these cells were labeled by a transsynaptic viral tracer injected into the raphe. B1 cells express the 5HT receptors 2C and 5A. Electrophysiology showed that activation of these receptors in B1 cells induced small inward currents. Intraventricular infusion of 5HT2C agonist or antagonist increased or decreased V-SVZ proliferation, respectively. These results indicate that supraependymal 5HT axons directly interact with NSCs to regulate neurogenesis via 5HT2C.

Directed differentiation from human pluripotent stem cells (hPSCs) has seen significant progress in recent years. However, most differentiated populations exhibit immature properties of an early embryonic stage, raising concerns about their ability to model and treat disease. Here, we report the directed differentiation of hPSCs into medial ganglionic eminence (MGE)-like progenitors and their maturation into forebrain type interneurons. We find that early-stage progenitors progress via a radial glial-like stem cell enriched in the human fetal brain. Both in vitro and posttransplantation into the rodent cortex, the MGE-like cells develop into GABAergic interneuron subtypes with mature physiological properties along a prolonged intrinsic timeline of up to 7 months, mimicking endogenous human neural development. MGE-derived cortical interneuron deficiencies are implicated in a broad range of neurodevelopmental and degenerative disorders, highlighting the importance of these results for modeling human neural development and disease.

The Major Key Technology Research Project “Concurrent Engineering” supported by the China National Hi-Tech R&D plan CIMS subject (863/CIMS) began in July 1995. It passed the final test in December 1997. This project was a research project with pre-determined applications background. Research and application of the research results have produced good results. A Chinese style concurrent engineering architecture and reference mode has been produced. A series of break thoughts in BPR (Business Process Reengineering) have been made with organization of the IPT (Integrated Product Development Team) and engineering support technologies. Several prototype tools were developed, including Product Development Process Modeling and Management, QFD-Based Schema Design and Decision Making, PDM-Based Concurrent Design, STEP-Based CAD/CAPP/CAM Integration, Design for Assembly, Design for Manufacturing, Computer Aided Fixture Design, and Machining Process Simulation. Finally, the research results were used in the development of two complex components in an aerospace application, and satisfactory results were obtained.