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To counter thin and lightweight targets such as drone swarms, a specialized design of 7.62 mm energetic bullets has been developed. These bullets utilize reactive materials as the core encased in a copper jacket, offering the advantages of impact-induced energy release, multiple damage, and lightweight. The study involved the preparation of three energetic bullets using the reactive materials (different ratio of PTFE-Mg-Bi2O3 and PTFE-Mg-Bi2O3-W) and systematically evaluating their destructive effect. The results showed that three energetic bullets (EB-A, EB-B, and EB-W) successfully penetrated two-layer stacked 2 mm 50# cold-rolled steel targets, and the respective reaction durations observed during the penetration process were 4.1, 3.5, and 9.2 ms. After armor-piercing, energetic bullets released an amount of chemical energy and produced fragmentation, deflagration reactions, and overpressure destructive effects. To further investigate the damage mechanism of the three reactive material-filled bullets, a detailed analysis of PTFE-Mg-based reactive material, such as reaction energy, burning rate, combustion temperature field, reaction overpressure, was conducted. Our work provides a comprehensive understanding of energy release performance of the reactive materials and damage behavior of the energetic bullets.

The hot compression tests of Fe–28Mn–11Al–1.5C–5Cr (wt.%) lightweight steel were carried out by Gleeble-3500 at temperature of 900, 1050 and 1150 °C with strain rates of 0.01 and 1 s−1. The effect of various precipitates on the hot deformation mechanism and dynamic recrystallization (DRX) mechanism was studied by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). When deformed at 900 °C, the dislocations tend to cut through intragranular κ carbides to form unidirectional microbands and deformation twins. The intergranular precipitates (intergranular κ carbides, B2 (FeAl type) precipitates and (Cr,Mn)23C6 precipitates) hinder the migration of the original grain boundaries, so that the discontinuous DRX (DDRX) is suppressed at the initial stage, but with the increase of strain, the dislocations accumulate at the grain boundaries to promote the nucleation of DRX grains. Meanwhile, the nucleation of DRX grains by continuous DRX (CDRX) mechanism within grains is also activated. Therefore, bimodal distribution of DRX grains is formed at low strain rate of 0.01 s−1, while the degree of DRX is low at high strain rate of 1 s−1. When the deformation temperature is 1050 °C, the content of microbands and deformation twins decreases. There are only a few B2 precipitates at the grain boundaries, so the original grain boundaries tend to bulge to promote DDRX nucleation. When deformed at 1150 °C, large-sized κ carbides are easily formed near the dislocations due to the fast diffusion rate of atoms, which inhibits the formation of microbands and deformation twins, and only slip bands are observed. There is no precipitate on the grain boundary, and the DDRX is the dominant mechanism of DRX. Moreover, the special yield-point-like elongation phenomenon has been proved to be caused by intragranular κ carbides.

Heterostructured austenitic stainless steels (ASS) are becoming a significant research area because of their outstanding mechanical properties and considerable potential for various applications. However, the thermal stability of heterogeneous microstructures, particularly the bimodal microstructure, has received limited attention and lacks systematic investigation. Additionally, there is a scarcity of reports regarding the biocompatibility of bimodal microstructures. Herein, the thermal stability and biocompatibility of the bimodal microstructure prepared by cold rolling and annealing in Cr–Mn–N series ASS (without and with Nb microalloying) are studied. The findings demonstrate that the bimodal microstructures of ASS are formed after annealing at 700 °C, 800 °C, and short-time annealing at 900 °C. Moreover, the addition of Nb significantly enhances the thermal stability of the bimodal microstructure and maintains the bimodal feature up to 1000 °C. The thermal stability of bimodal microstructures depends on the competition in coarse and fine grains growth. The good thermal stability of Nb(C, N) at high temperatures leads to consistently higher pinning force within the fine-grained zone. As a result, the growth of fine grains lags behind that of coarse grains, which leads to the persistence of bimodal microstructure at higher temperatures. The bimodal microstructure of ASS demonstrates superior biocompatibility, attributed to its ability to promote higher cell viability, exhibit stronger fibronectin intensity, and facilitate a wider fibronectin expression network in osteoblasts. These characteristics make the bimodal ASS more favorable for osteoblast attachment and proliferation compared to its coarse-grained counterpart. This study significantly enhances our understanding of the thermal stability and cellular functionality of bimodal ASS, highlighting its potential for various biomedical applications.

A flash tempering process has been demonstrated for low-carbon low-alloy lath martensite, which includes heating the sample to 750 °C (Ac1: 752 °C), dwelling at 750 °C for 2 s, and quenching directly to room temperature. The high temperature accelerated the spread of the supersaturated carbon atoms in the lath martensite, activated the dislocation migrations and thus their combining and annihilation, and promoted the mass recrystallisation. The reduced dwelling time inhibited the coarsening of the martensitic laths and suppressed the growth of the recrystallized structures. The combination of higher temperature and the shorter dwelling period, so-called flash tempering, gives rise to the same microstructure and mechanical properties as those obtained by the conventional tempering process (i.e., dwelling at 600 °C for 1 h). The high efficient flash tempering, possessing significantly reduced energy and time consumptions, may have important consequence in industrialization of tempering process.

The composition design of titanium alloys and some preparation processes require accurate diffusion kinetic databases. However, the current database of diffusion kinetics at high temperatures is not yet complete. In this work, the diffusion kinetics of five binary systems, Ti–Zr, Ti–Nb, Ti–Mo, Ti–Ta and Ti–W, were systematically investigated at 1300–1500 °C. The interdiffusion coefficients and impurity diffusion coefficients of the Ti-X binary systems were calculated according to the Den-Broeder and Hall methods. The results showed that the Ti–Nb, Ti–Mo, Ti–Ta and Ti–W exhibited strong concentration dependence of the diffusion coefficients at the temperature of 1300–1500 °C compared to the Ti–Zr system, which was considered as the domination of the difference in intrinsic properties between elements. Besides, the activation energies of diffusion were evaluated based on the Arrhenius relationship, where the Ti–Zr system exhibited the lowest activation energy among the five diffusion systems, followed by Ti–Nb, Ti–Mo, Ti–Ta and Ti–W systems. The diffusion kinetic data of titanium-based alloys at high temperatures were obtained in the present work, providing important references for the design, preparation and processing of new titanium alloys.

In this work, an innovative cyclic intercritical quenching process has been proposed for achieving excellent mechanical properties in terms of strength and plasticity, which results in a lamellar martensitic-ferritic dual-phase steel. The microstructural evolution under cyclic heat treatment was thoroughly investigated, and the mechanism that enables the lamellar structure to enhance its strength-plasticity matching was also explored. The experimental results revealed that the incomplete austenitization process inhibits the coarsening of the reversed austenite, and the cyclic intercritical quenching procedure finer and more evenly distributes the reversed austenite. The single intercritical quenching (C1) generated mostly massive martensite with traces of ferrite, whereas three-cyclic intercritical quenching (C3) yielded a fine and uniformly distributed lamellar structure. A comparison in terms of the mechanical properties between C3 and C1 steels indicates that uniform elongation, total elongation, and the product of strength and uniform elongation of the C3 steel increased by 85.4%, 47.3%, and 65.0%, respectively, while ultimate tensile strength was dropped by only 11.0%. In addition, the yield ratio of C3 steel is just 0.48. The slight decrease in strength is due to the fine lamellar microstructure. The high plasticity is attributed to the good deformation compatibility between lamellar ferrite and lamellar martensite with excellent plastic deformability. Therefore, cyclic mechanical heat treatment is very promising for the production of low-cost dual-phase steels.

Titanium-tantalum alloys with lamellar microstructure were fabricated by cold isostatic pressing under 400 MPa and pressure-free sintering at 1600 °C. By such a low-cost powder metallurgy method, the Ti–Ta alloy exhibited the tensile yield strength of 1124 MPa at room temperature, which was twice that of the cast Ti–Ta alloys. The microstructure and mechanical properties were characterized in detail to elucidate the deformation behavior and the strengthening mechanism of the Ti–Ta alloys prepared by powder metallurgy. With the increasing Ta content, the width of the α laths decreased, and that of the β laths increased, leading to the precipitation of the acicular α in the β laths. Correspondingly, the yield and ultimate strength increased, while the strain to failure decreased. Lamellar structure strengthening was determined to be the dominating mechanism for the high strength of the Ti–Ta alloys prepared by powder metallurgy. After quantitatively evaluating the contributions of laths, solute atoms, prior β grain boundaries, and dislocations, a model was established to illustrate the yield strength of the Ti–Ta alloys. The calculated values agreed well with the measured strength values of the Ti–Ta alloys, indicating that this model is effective in forecasting the strength of the dual-phase Ti alloys with lamellar structure.

Generally, binary immiscible alloys have poor plasticity due to weak interfacial bonding. In this study, an amorphous interlayer was introduced between Mo and Cu phases in Mo-Cu alloys by using the high-temperature infiltration method. With the increase of infiltrated temperature from 1300 °C to 1450 °C, the thickness of the amorphous interlayer wad increased from 2 nm to 13 nm. The formation process, thermodynamic driving force, stability of the amorphous interlayer in Mo-Cu alloy, and its contribution to mechanical properties were systematically investigated. By using the “macroscopic atom approach” Miedema's model, the thermodynamic driving force and stability of the amorphous interlayer were proved. It was found that the thickening of the amorphous interlayer can significantly improve the interfacial bonding, thus leading to an increase in the tensile strength of the Mo-Cu alloy from 520 to 600 MPa and failure strain from 0.15 to 0.31 The deformation behavior of the Mo-Cu alloy shows that the amorphous interlayer can effectively absorb interfacial dislocations during deformation, and relieve the stress concentration at the interface by crystallization, thus delaying the initiation and propagation of cracks at phase boundaries, which broke through the limitation of the trade-off between strength and plasticity of such Mo-Cu immiscible materials.

Thalamic regulation of cortical function is important for several behavioral aspects including attention and sensorimotor control. This region has also been studied for its involvement in seizure activity. Among the NMDA receptor subunits GluN2C and GluN2D are particularly enriched in several thalamic nuclei including nucleus reticularis of the thalamus (nRT). We have previously found that GluN2C deletion does not have a strong influence on the basal excitability and burst firing characteristics of reticular thalamus neurons. Here we find that GluN2D ablation leads to reduced depolarization-induced spike frequency and reduced hyperpolarization-induced rebound burst firing in nRT neurons. Furthermore, reduced inhibitory neurotransmission was observed in the ventrobasal thalamus (VB). A model with preferential downregulation of GluN2D from parvalbumin (PV)-positive neurons was generated. Conditional deletion of GluN2D from PV neurons led to a decrease in excitability and burst firing. In addition, reduced excitability and burst firing was observed in the VB neurons together with reduced inhibitory neurotransmission. Finally, young mice with GluN2D downregulation in PV neurons showed significant resistance to pentylenetetrazol-induced seizure and differences in sensitivity to isoflurane anesthesia but were normal in other behaviors. Conditional deletion of GluN2D from PV neurons also affected expression of other GluN2 subunits and GABA receptor in the nRT. Together, these results identify a unique role of GluN2D-containing receptors in the regulation of thalamic circuitry and seizure susceptibility which is relevant to mutations in GRIN2D gene found to be associated with pediatric epilepsy.

Lightweight, deformable and highly conductive conductors are rather appealing in flexible electronics devices such as electromagnetic interference (EMI) shielding films; however, the most commonly used metallic foils or carbon nanomaterials suffer from critical limitation of either film thickness or electrical conductivity. Herein, we present a facile approach to rapidly fabricate sintered liquid metal submicron particles (LMSPs) films in combination spray-coating with direct nanosecond ultraviolet (UV) laser sintering. High conductive, μm-thick sintered LMSPs films were prepared owing to the self-limited penetration depth of UV laser, and their sheet resistances are easily tuned at least seven orders of magnitude by the laser processing parameters. A calculated parametric map upon particle diameter and laser fluence whether or not a liquid metal particle is ruptured has been obtained and it is quite well in accordance to the experiment results. Such laser-sintered LMSPs films are finally utilized to fabricate shielding films with superior EMI shielding effectiveness (SE) of ∼33 dB and specific EMI SE over thickness (SSE/t) of ∼27500 dB•cm2•g−1, and flexible electromagnetic metamaterials with a high absorption above 99.9 % at resonance frequency of 12.9 GHz and 14.3 GHz, showing their high potential for flexible EMI shielding and electromagnetic wave absorption applications.

To avoid the aimless design of shaped charge liner (SCL) material for obtaining deep penetration and large penetration holes in reinforced concrete targets, new design principles are proposed in this study. Following the principles, an intermetallic-compound-reinforced Ti-17Al-29Nb alloy was prepared via hot isostatic pressing (HIP) sintering. This alloy shows high dynamic compressive strength (1583 MPa), high dynamic compressive plasticity (35 %), high elevated-temperature tensile strength (414 MPa at 800 °C), and low elevated-temperature plasticity (6 % at 800 °C). The penetrating experiments showed that the Ti-17Al-29Nb alloy liner penetrated through the 600-mm-thick C40 concrete target, forming large penetration holes. Although the penetration depth was slightly lower than that of the most commonly used pure copper liner, the diameter of the exit hole was 2.1 times that of the pure copper liner. The high jet tip velocity (7651 m/s) and large jet diameter (a maximum of 0.28 CD) were the key factors to form the high penetration depth and large penetration hole. This study not only brings a new type of SCL material with excellent penetration performance against reinforced concrete targets but also provides a new research direction for the design and selection of the SCL materials.

The background, demand, new formation, system architecture, and platform technology of port industry in smart and green era were analyzed.Firstly, the background and demand of port industry in smart and green era were introduced.Then the new formation and system architecture of parallel port industry were demonstrated.Next, the novel platform technology of port industry in smart and green era was discussed, including the Internet of minds, knowledge automation, hybrid-augmented intelligence and so on.Finally, an application case study of parallel systems in smart and green port was presented, i.e., port ship management system.

Reactive structural materials are of interest in military applications due to their impact-initiated characteristics. The determination of critical impact velocity is of crucial importance in designing munitions to produce a maximum destructive effect on the target upon impact. Here, combining high-speed photography and image processing technique, we demonstrate an approach to determine the critical impact velocity through quantitatively assessing the energy-release characteristics of a Zr-Ti-Nb reactive alloy under high-speed impact. The Zr-Ti-Nb alloy is fabricated by powder metallurgy and has high strength and sufficient ductility under dynamic loading. By conducting a series of ballistic impact experiments, the relationship between the impact velocity of alloy projectiles and light emission from burning fragments is obtained and discussed. Two critical impact velocities are determined. The first represents the minimum impact velocity required for initiating the intense exothermic reaction of the alloy projectiles, while the second denotes the impact velocity when the extent of reaction reached the maximum. By analyzing the fragments recovered at different velocities, it is proved that the fragmentation behavior of the alloy projectiles is found to be highly dependent on the impact velocity. This results in obvious different energy-releasing characteristics of Zr-Ti-Nb alloy, and the corresponding mechanism was also discussed.

Intermetallic compounds or solid solutions can form between Zr and Mo/W, in which the multiphase of the diffusion may be influenced by each other. Interdiffusion kinetic data in such intermetallic systems are highly demanded for material design. In this work, solid–solid diffusion couples of Zr-Mo and Zr-W were prepared by the fixture method, and the interdiffusion behaviors of Zr-Mo and Zr-W at 1300–1500 °C were systematically investigated. The results showed that the intermetallic compounds Mo2Zr/W2Zr formed in the Zr-Mo/W diffusion systems. The growth constants of the Mo2Zr and W2Zr phases varied with temperature in accordance with the Arrhenius relationship, and the activation energies of growth were 109 kJ/mol and 285 kJ/mol, respectively. In addition, (Zr, Mo) solid solution formed between Mo2Zr and pure Zr as diffusion proceeded, resulting in a lower chemical potential for the formation of Mo2Zr. The den Broeder method was used in calculating the interdiffusion coefficients of the solid solution. The results showed that the interdiffusion coefficient in the (Zr, Mo) solid solution decreased with the increase of Mo concentration. Moreover, the diffusion activation energy of the solid solution was evaluated based on the Arrhenius relationship, and the activation energy was 145–170 kJ/mol when the Mo content was in the range of 2–10 at. %. These diffusion kinetic data provide a reference for the composition design and preparation technic of Zr-based alloys.

In order to effectively employ through-glass vias (TGVs) for high-frequency software package design, it is crucial to accurately characterize the S-parameters of vertical interconnection structures in 3D glass packaging. A methodology is proposed for the extraction of precise S-parameters using the transmission matrix (T-matrix) to analyze and evaluate the insertion loss (IL) and reliability of TGV interconnections. The method presented herein enables the handling of a diverse range of vertical interconnections, encompassing micro-bumps, bond-wires, and a variety of pads. Additionally, a test structure for coplanar waveguide (CPW) TGVs is constructed, accompanied by a comprehensive description of the equations and measurement procedure employed. The outcomes of the investigation demonstrate a favorable concurrence between the simulated and measured results, with analyses and measurements conducted up to 40 GHz.

Generally, the development of ship plate steels is mainly concerned with the improvement of strength and toughness, such as F32 and F36. Due to the strength–ductility trade-off, it is difficult to combine excellent ductility with strength improvement, resulting in a poor deformation ability of the traditional ship plate steels during collision. In the present study, a series of high-ductility ship plate steels with property gradients were obtained by multi-phase microstructure control. The strength–ductility matching mechanism was analyzed. Meanwhile, the roles of M/A islands and lamellar pearlites in plastic deformation were also revealed. The results show that the microstructure of “quasi-polygonal ferrite + granular bainite + M/A islands + fewer lamellar pearlites” has the best strength–ductility match. The excellent ductility is mainly dependent on dispersive kernel average misorientation, recrystallized grains without distortion, and soft grains. In addition, the longer branch crack can effectively relieve the stress concentration at the tip of the main crack. Compared with lamellar pearlites, the dispersed M/A island grains have a higher strength contribution and more stable γ-fibers, which is beneficial to delay the appearance of internal micro-voids and micro-cracks. However, the lamellar pearlites can coordinate deformation only when the orientation of thinner lamellae exceeds two.

Multi-principal elements alloys (MPEAs) have been attracted extensive attention in industry due to their extraordinary properties. However, owning to their large degree of freedom in composition design, finding the principal influence factors of the material properties and further coordinating a desirable combination of conflicting properties is always a challenge. In this respect, we have developed a strategy on studying the MPEAs for its composition design in a certain mechanical property by high throughput preparation of powder metallurgy and by machine learning. We chose Zr-Ti-Nb-O alloys as target materials. To unveil key features that mainly influence the mechanical properties, models selection, features screening, and further features importance ordering were performed. The results indicate that the strength and plasticity are dominated by Λ parameter, difference of atomic radius, difference of shear modulus, etc. The prediction error for the strength and plasticity can reach to below 10% and 16%, respectively. According to analysis of the key features, a strength model is modified and used for evaluating the contributions of solid solution strengthening among principle and trace elements. The strategy proposed here will be applicable on element selections for a large variety of material property modulations in the MPEAs prepared by powder metallurgy.

Globus pallidus externa (GPe) is a nucleus in the basal ganglia circuitry involved in the control of movement. Recent studies have demonstrated a critical role of GPe cell types in Parkinsonism. Specifically increasing the function of parvalbumin (PV) neurons in the GPe has been found to facilitate motor function in a mouse model of Parkinson's disease (PD). The knowledge of contribution of NMDA receptors to GPe function is limited. Here, we demonstrate that fast spiking neurons in the GPe express NMDA receptor currents sensitive to GluN2C/GluN2D-selective inhibitors and glycine site agonist with higher efficacy at GluN2C-containing receptors. Furthermore, using a novel reporter model, we demonstrate the expression of GluN2C subunits in PV neurons in the GPe which project to subthalamic nuclei. GluN2D subunit was also found to localize to PV neurons in GPe. Ablation of GluN2C subunit does not affect spontaneous firing of fast spiking neurons. In contrast, facilitating the function of GluN2C-containing receptors using glycine-site NMDA receptor agonists, D-cycloserine (DCS) or AICP, increased the spontaneous firing frequency of PV neurons in a GluN2C-dependent manner. Finally, we demonstrate that local infusion of DCS or AICP into the GPe improved motor function in a mouse model of PD. Together, these results demonstrate that GluN2C-containing receptors and potentially GluN2D-containing receptors in the GPe may serve as a therapeutic target for alleviating motor dysfunction in PD and related disorders.

Synthesis of graphene at high temperature offers an alternative route for large-scale production on a short time scale. Through the solid-state exothermic reaction of the polytetrafluoroethylene (PTFE)-Al energetic material, single and few-layer graphene having a lateral size in tens of nanometers are produced with an ultralow power consumption due to the self-sustained characteristics of the reaction. The graphene can directly disperse in ethanol to form stable dispersion and by evaluating in half-cell configuration, the graphene exhibits a stable cycling performance over 1000 cycles. The positive correlation between the dimension of the PTFE precursor and graphene demonstrates the feasibility of synthesizing powdered graphene in a controllable manner.

Impaired behavioral flexibility and repetitive behavior is a common phenotype in autism and other neuropsychiatric disorders, but the underlying synaptic mechanisms are poorly understood. The trans-synaptic glutamate delta (GluD)-Cerebellin 1-Neurexin complex, critical for synapse formation/maintenance, represents a vulnerable axis for neuropsychiatric diseases. We have previously found that GluD1 deletion results in reversal learning deficit and repetitive behavior. In this study, we show that selective ablation of GluD1 from the dorsal striatum impairs behavioral flexibility in a water T-maze task. We further found that striatal GluD1 is preferentially found in dendritic shafts, and more frequently associated with thalamic than cortical glutamatergic terminals suggesting localization to projections from the thalamic parafascicular nucleus (Pf). Conditional deletion of GluD1 from the striatum led to a selective loss of thalamic, but not cortical, terminals, and reduced glutamatergic neurotransmission. Optogenetic studies demonstrated functional changes at thalamostriatal synapses from the Pf, but no effect on the corticostriatal system, upon ablation of GluD1 in the dorsal striatum. These studies suggest a novel molecular mechanism by which genetic variations associated with neuropsychiatric disorders may impair behavioral flexibility, and reveal a unique principle by which GluD1 subunit regulates forebrain circuits.

Three multi-oxidants reactive materials (59PTFE-23Al–18Bi2O3, 59PTFE-26Al–15Fe2O3, and 59PTFE-27Al–14MoO3) were prepared and the effect of metal oxides on the reaction characteristics was systematically investigated. Reaction energy, burning speed, and specific volume of explosive were measured, and the dynamic mechanical properties were characterized by the split-Hopkinson pressure bar. The reaction processes under high strain rate and high-speed impact were recorded by the high-speed camera. Our results indicate that the Bi2O3 is the most effective oxidant in increasing the reaction efficiency of the PTFE-Al system, which leads to the largest combustion flare and longest reaction time under high strain rate and high-speed impact. Furthermore, we demonstrate that the 59PTFE-23Al–18Bi2O3 has the best penetration performance at a speed of 1200 m/s due to its high gas production rate compared to the other systems. Keywords: Reactive materials, Multi-oxidants, Reaction characteristics, Destructive effect

Chronic pain is a debilitating condition involving neuronal dysfunction, but the synaptic mechanisms underlying the persistence of pain are still poorly understood. We found that the synaptic organizer glutamate delta 1 receptor (GluD1) is expressed postsynaptically at parabrachio-central laterocapsular amygdala (PB-CeLC) glutamatergic synapses at axo-somatic and punctate locations on protein kinase C δ -positive (PKCδ+) neurons. Deletion of GluD1 impairs excitatory neurotransmission at the PB-CeLC synapses. In inflammatory and neuropathic pain models, GluD1 and its partner cerebellin 1 (Cbln1) are downregulated while AMPA receptor is upregulated. A single infusion of recombinant Cbln1 into the central amygdala led to sustained mitigation of behavioral pain parameters and normalized hyperexcitability of central amygdala neurons. Cbln2 was ineffective under these conditions and the effect of Cbln1 was antagonized by GluD1 ligand D-serine. The behavioral effect of Cbln1 was GluD1-dependent and showed lateralization to the right central amygdala. Selective ablation of GluD1 from the central amygdala or injection of Cbln1 into the central amygdala in normal animals led to changes in averse and fear-learning behaviors. Thus, GluD1-Cbln1 signaling in the central amygdala is a teaching signal for aversive behavior but its sustained dysregulation underlies persistence of pain. Significance statement: Chronic pain is a debilitating condition which involves synaptic dysfunction, but the underlying mechanisms are not fully understood. Our studies identify a novel mechanism involving structural synaptic changes in the amygdala caused by impaired GluD1-Cbln1 signaling in inflammatory and neuropathic pain behaviors. We also identify a novel means to mitigate pain in these conditions using protein therapeutics.

Dysregulation of brain angiotensin II (AngII) signaling results in modulation of neuronal ion channel activity, an increase in neuronal firing, enhanced sympathoexcitation, and subsequently elevated blood pressure. Studies over the past two decades have shown that these AngII responses are mediated, in part, by reactive oxygen species (ROS). However, the redox-sensitive target(s) that are directly acted upon by these ROS to execute the AngII pathophysiological responses in neurons remain unclear. Calcium/calmodulin-dependent protein kinase II (CaMKII) is an AngII-activated intra-neuronal signaling protein, which has been suggested to be redox sensitive as overexpressing the antioxidant enzyme superoxide dismutase attenuates AngII-induced activation of CaMKII. Herein, we hypothesized that the neuronal isoform of CaMKII, CaMKII-alpha (CaMKIIα), is a redox-sensitive target of AngII, and that mutation of potentially redox-sensitive amino acids in CaMKIIα influences AngII-mediated intra-neuronal signaling and hypertension. Adenoviral vectors expressing wild-type mouse CaMKIIα (Ad.wtCaMKIIα) or mutant CaMKIIα (Ad.mutCaMKIIα) with C280A and M281V mutations were generated to overexpress either CaMKIIα isoform in mouse catecholaminergic cultured neurons (CATH.a) or in the brain subfornical organ (SFO) of hypertensive mice. Overexpressing wtCaMKIIα exacerbated AngII pathophysiological responses as observed by a potentiation of AngII-induced inhibition of voltage-gated K+ current, enhanced in vivo pressor response following intracerebroventricular injection of AngII, and sensitization to chronic peripheral infusion of AngII resulting in a more rapid increase in blood pressure. In contrast, expressing the mutant CaMKIIα in CATH.a neurons or the SFO failed to intensify these AngII responses. Taken together, these data identify neuronal CaMKIIα as a redox-sensitive signaling protein that contributes to AngII-induced neuronal activation and hypertension. Keywords: Angiotensin II, Reactive oxygen species, Calcium/calmodulin-dependent protein kinase IIα, Neurons, Hypertension, Redox signaling

Adding an appropriate interfacial layer is a viable way to decrease the WW contiguity and enhance the interfacial bonding of WCu alloy simultaneously, hence increase the tensile ductility. In this regard, we prepared a new kind of WMoCu alloy with transition phase (TP) existing between W particles and Cu matrix using infiltration method. The TP consisting of amorphous and nanocrystalline structure is formed between the W particles and the Cu matrix. The formation of the TP simultaneously decreases the WW contiguity and enhances bonding with both W particles and Cu matrix, leading to the good tensile ductility of the WMoCu alloy. The underlying formation mechanism of the TP is thoroughly studied. The WMoCu alloy exhibits excellent ductility under both compressive and tensile loading at room temperature. Under the quasi-static tensile loading, the critical failure strain of the WMoCu alloy is 0.18. Our analysis demonstrates that a strong bonding is formed between the TP and the adjacent phases. Keywords: WMoCu alloy, Transition phase, Amorphous and nanocrystalline phase, Interfacial bonding, Tensile ductility

By evenly mixing polytetrafluoroethylene-silicon energetic materials (PTFE-Si EMs) with tin oxide (SnO2) particles, we demonstrate a direct synthesis of graphene-encapsulated SnO2 (Gr-SnO2) nanoparticles through the self-propagated exothermic reaction of the EMs. The highly exothermic reaction of the PTFE-Si EMs released a huge amount of heat that induced an instantaneous temperature rise at the reaction zone, and the rapid expansion of the gaseous SiF4 product provided a high-speed gas flow for dispersing the molten particles into finer nanoscale particles. Furthermore, the reaction of the PTFE-NPs with Si resulted in a simultaneous synthesis of graphene that encapsulated the SnO2 nanoparticles in order to form the core-shell nanostructure. As sodium storage material, the graphene-encapsulated SnO2 nanoparticles exhibit a good cycling performance, superior rate capability, and a high initial Coulombic efficiency of 85.3%. This proves the effectiveness of our approach for the scalable synthesis of core-shell-structured graphene-encapsulated nanomaterials.

Due to its negligible solubility, it is difficult to obtain a W-30Cu composite with a homogenous microstructure. However, with a selected W skeleton, a homogeneous phase distribution was achieved for a W-30Cu composite in the present study. By detailed characterization of the mechanical performance and microstructure of the W-30Cu composite, as well as the stress distribution state under a loading condition, the effects of microstructure homogeneity on the mechanical properties and failure mechanisms are identified. The mechanisms by which the ductility and strength depend on microstructure homogeneity contain the effects on plastic deformation and stress coordination of the Cu phase network. The dominant factors for the high ductility and strength of W-30Cu composites are proposed.

Energetic structural material is a kind of materials that are inert under normal conditions but could produce exothermic chemical reaction when subjected to impact. This report shows a kind of energetic structural material of tungsten (W)-polytetrafluoroethylene (PTFE)-aluminum (Al) with density of 4.12 g/cm3, excellent ductility and dynamic compressive strength of 96 MPa. Moreover, 50W-35PTFE-15Al (wt%) can exhibit a high reaction energy value of more than 2 times of TNT per unit mass and 5 times of TNT per unit volume, respectively, but with excellent insensitivity compared with traditional explosives. Under thermal conditions, the W-PTFE-Al composite can keep stable at 773 K. Under impact loading, when the strain rate up to ∼4820 s−1 coupled with the absorbed energy per unit volume of 120 J/cm3, deflagration occurs and combustion lasts for 500 μs. During impact compressive deformation, the PTFE matrix is elongated into nano-fibers, thus significantly increases the reaction activity of W-PTFE-Al composites. The nano-fiber structure is necessary for the reaction of W-PTFE-Al composites. The formation of PTFE nano-fibers must undergo severe plastic deformation, and therefore the W-PTFE-Al composites exhibit excellent insensitivity and safety. Furthermore, the reaction mechanisms of W-PTFE-Al composites in argon and in air are revealed.

Our previous study has reported that superoxide mediates ischemia-reperfusion (IR)-induced necrosis in mouse skeletal muscle. However, it remains poorly understood whether IR induces apoptosis and what factors are involved in IR-induced apoptosis in skeletal muscle. Using a murine model of tourniquet-induced hindlimb IR, we investigated the relationship between mitochondrial dysfunction and apoptosis in skeletal muscle. Hindlimbs of C57/BL6 mice were subjected to 3 h ischemia and 4 h reperfusion via placement and release of a rubber tourniquet at the greater trochanter. Compared to sham treatment, tourniquet-induced IR significantly elevated mitochondria-derived superoxide production, activated opening of mitochondrial permeability transition pore (mPTP), and caused apoptosis in the gastrocnemius muscles. Pretreatment with a superoxide dismutase mimetic (tempol, 50 mg/kg) or a mitochondrial antioxidant (co-enzyme Q(10), 50 mg/kg) not only decreased mitochondria-derived superoxide production, but also inhibited mPTP opening and apoptosis in the IR gastrocnemius muscles. Additionally, an inhibitor of mPTP (cyclosporine A, 50 mg/kg) also inhibited both mPTP opening and apoptosis in the IR gastrocnemius muscles. These results suggest that mitochondria-derived superoxide overproduction triggers the mPTP opening and subsequently causes apoptosis in tourniquet-induced hindlimb IR.