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In this work, pre-strain annealing strengthening (PSAS) effect was investigated in an extruded Mg-1.0Gd-1.5 Zn (wt.%) alloy with respect to different grain sizes. The evolution of microstructures was provided by scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) under the initial state, pre-compression, intermediate annealing and re-compression conditions. The obtained results showed a grain size-dependent PSAS effect in the alloy. The sample with larger grain sizes corresponded to a higher strengthening effect, which mainly resulted from a more remarkable hindrance for the growth of existing twins and a larger proportion of activation for the nucleation of new twins. This was closely associated with the increase of back stress and friction stress for twin boundary motion impeded by the larger restraint of dislocations, the higher stress field surrounding solutes and the more Zn segregation. In addition to twinning behavior, Guinier Preston (G.P.) zones on basal 〈a〉 dislocations were found after intermediate annealing and provided an extra strengthening by inhibiting the motions of gilding pre-existing dislocations and newly formed ones, but it was independent on the grain size.

Silver nanowire (AgNW) films have been widely used as flexible transparent electrodes due to the high electrical conductance and high transmittance in the visible range. The infrared (IR) properties of AgNW films, however, are seldom discussed. Here, we show that ultrathin AgNWs present high transmittance in the visible range (∼95%) and high reflectance (60–70%) in the IR range of 8–14 μm. Such a significant difference makes AgNW films invisible to naked eyes but visible under an IR camera, being an ideal selection for anti-counterfeit technologies, while no excitation is required. We have demonstrated that AgNW films can be spray-coated on either flat or microstructured surfaces with high conformability and high scratch-resistance, and thus these anti-counterfeiting materials can be applied to a variety of applications. The AgNW-based anti-counterfeiting may be helpful for combating counterfeiting crimes in the fields of medicines, artwork, banknotes, brand luxuries, industrial parts, and so on. Keywords: Silver nanowires, Anti-counterfeiting, Infrared light, Excitation-free, Conformability

Grain growth can modify the texture orientation and the fraction of different texture component. The thermal stability of two texture component in an extruded magnesium AZ31 alloy was investigated. Three types samples with different texture distribution were prepared. The results show that normal grain growth takes place in the magnesium AZ31 alloy during annealing at 300 °C and 450 °C. But the grain growth does not lead to the strengthening of either texture component. Both the ⊥ED texture and //ED texture components show good thermal stability, without influence of the texture volume fraction. The two different texture component possess comparable boundary migration ability, so grains of the two texture component consume indifferently the other grains, or are equally consumed during annealing. Keywords: Mg alloy, Texture, Thermal stability, Grain growth annealing, Twinning

The intrinsic poor electrical and large volume expansion upon cycling of ZnO raise up challenging kinetic issues. In this work, ZnO@TiO2 core/shell nanorod arrays heterostructure grown directly on carbon cloth is designed and fabricated. The atomic layer deposition coated TiO2 thin layer can not only function as an efficient stress buffer during electrochemical reaction, but also provide enhanced electronic conductivity by forming a heterostructure with ZnO. The ZnO@TiO2 nanorod arrays on carbon cloth can simultaneously achieve the high capacity and high-rate long cycle life (1000 mA h/g for 250 cycles at 1 A/g), which is far superior to that of bare ZnO nanorod arrays on carbon cloth without TiO2 shell. The density functional theory calculations reveal the strong chemical coupling between ZnO and TiO2, which realizes band gap tailoring and significant charge redistribution of both ZnO and TiO2. Such a unique structure endows the as prepared ZnO@TiO2 on carbon cloth great potential as high performance three-dimensional flexible electrode in Li-ion batteries.

Gastric cancer (GC), a malignant tumor originating from the epithelium of the gastric mucosa, has been endangering human health for many years. The current standard surgical resection is not ideal for advanced gastric cancer. Therefore, it is urgent to find new prognostic indicators as well as drug targets. In our study, referring to clinicopathological characteristics of GC, we found that raftlin lipid raft linker 1 (RFTN1) had high expression in primary GC tissues. Subsequently, we showed that knockdown of RFTN1 inhibited GC cell proliferation and induced cell cycle arrest in G0/G1 phase, and promoted GC cell apoptosis. Conversely, overexpression of RFTN1 promoted GC cell proliferation and G0/G1 to S phase transition, and inhibited apoptosis. Furthermore, cell derived xenograft experiments showed that knockdown of RFTN1 inhibited GC cell growth in vivo. Notably, our experimental data demonstrated that knockdown of RFTN1 could inhibit the AKT signaling pathway and activate p38 signaling pathway, whereas overexpression of RFTN1 did the opposite. Moreover, the effects caused by knockdown of RFTN1 in GC cells could be rescued by using SC79 (an AKT activator). In conclusion, these results indicated that RFTN1 plays an oncogenic role in GC, and might act as a prospective prognostic indicator or therapeutic target for GC patients.

In vivo and real-time analysis could reflect a more real biological state, which was of great significance to the study of complex life processes. In this work, we constructed an online extraction electrospray ionization (OE-ESI) ion source as the interface of microdialysis and mass spectrometry, which realized real-time analysis of metabolites in vivo without sample pretreatment process. The ion source was consisted of three coaxial capillaries, and the parameters of the ion source were optimized. The OE-ESI ion source could simultaneously extract, desalt and ionize the analyte, successfully perform MS analysis of analyte in high salt system, and overcome the ion suppression caused by salt ion. Compared with commercial ESI MS, the OE-ESI ion source had excellent salt tolerance and stability. MD-OE-ESI MS realized the real-time MS detection of metabolites in the living body, avoiding the complex desalting process. In the rat liver ischemia-reperfusion model, a total of 24 metabolites, including glucose, glutamate, glutamine, etc., were monitored in real time mode, and their concentrations had varying degrees of change during the experimental process compared with the control group. This platform, we believed, would be helpful for real-time monitoring of biological metabolites in vivo, and had great application prospects to study physiological processes.

Filtering capacitors with high energy densities are of critical importance in stabilizing the pulse signal of circuits that require the conversion of alternating current to direct current, which is however far from satisfactory at current stage due to lack of a reasonable design. Here, we report an ultrafast aqueous electrochemical capacitor based on highly conductive and continuously cross-linked poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) nanomesh films fabricated using a rational morphology engineering strategy. The interpenetrating polymer network promoted an efficient electron transfer and provided smooth channels for ion transport while exposing a significant number of accessible interfacial area to electrolyte. In addition to the large phase angle of − 84° at 120 Hz, this polymer-based electrochemical capacitor exhibited an extremely high areal specific capacitance of 1087 μF cm−2 and areal specific energy density of 544 μF V2 cm−2, far superior to those of most reported aqueous filtering capacitors. Furthermore, it can efficiently smoothen the ripples generated when arbitrary alternating current waveforms were converted into straight signals over a wide frequency range of 1–10,000 Hz. Moreover, it was conveniently integrated with a rotating disk triboelectric nanogenerator for ripple filtering and pulse energy smoothing. This work brings a view for aqueous filtering capacitors with high performance.

In the present study, the effect of different (0002) distributions ( // ND (MT texture) and // ND together with // RD (BT texture)) on strength of slip and twinning predominant deformations of a Mg AZ31 plate was systematically studied. The results show that the tensile yield strengths along the TD are similar in the two textures, but yield strength in compression along the TD is obviously higher in BT texture than in MT texture. Here, TD, RD and ND refer to the transverse direction, rolling direction and normal direction of the AZ31 plate, respectively. An analysis on Schmid factors demonstrates that the different compression yield strengths in the two texture mainly results from their different boundary obstacle effect against { 10 1 2 } twinning. The mechanism was further analyzed by a compound use of the activation stress difference of slip/twinning (ΔStress) and geometrical compatibility factor ( m ′ ) between neighboring grains. A lower ΔStress or a higher m ′ mean a lower boundary obstacle effect. There is a similar ΔStress in the two texture under compression, but an obvious lower m ′ in BT texture than that in MT texture. The lower m ′ in BT texture than in MT texture leads to a higher boundary obstacle effect and the resultant higher compressive yield strength in BT texture. It is found that the presence of a large number of neighboring grains with a high angle between their c-axes in BT texture mainly accounts for the lower m ′ .

The mechanical and twinning behavior of Mg alloys containing a monolithic texture component have been extensively studied; however, studies on samples with multi texture components are much insufficient. In this study, the quantitative relationship between the mechanical behavior under tension along the extrusion direction (ED) of Mg AZ31 rods and the percentages of bimodal texture components // ED (19–87%) and ⊥ED were systematically studied. The component // ED favors { 10 1 ¯ 2 } twinning and is soft orientation; however, the component ⊥ED favors prismatic slip and is hard orientation. The results show that the yield strength does not decrease linearly with an increase in the percentage of the soft orientations and show a deviation from the calculations using the conventional rule of mixtures. A higher percentage of the soft grains increases this deviation when the percentage is below 50%, and decreases it over 50%. The ultimate strengths, however, do not show an obvious dependence on the percentage of the soft orientations. Subsequently, the corresponding mechanisms are discussed and a modified rule of mixtures was developed. Bimodal texture components stimulate the activation of { 10 1 ¯ 2 } twin variants with a low Schmid factor and the presence of more variants within one grain. Conventional strain accommodation rule was used to analyze this twinning behavior, but it cannot explain the experimental observations. Crystal-plasticity based finite element modeling was employed to analyze this strange twinning behavior. The results indicate that the interaction among twin variants, rather than deformation in neighboring grains, plays a major role in the activation of twins with a low Schmid factor, due to a hard deformation propagation from the soft grains to the hard grains. This finding provides an important complementation to the strain accommodation theory.

Aligned carbon nanotube (CNT) arrays are promising candidates for strain sensors owing to their scalable preparation and excellent conductivity and stretchability. However, aligned CNT arrays are limited by low strain sensitivity and buckling deformation. In addition, cross-stacked CNT array films layer-by-layer assembled on soft substrates exhibit anisotropic mechanical behavior due to their asymmetric layered structures. In this work, we introduced a chemically hybridized CNT-graphene (G/CNT) film in which CNT crossbars are effectively welded together by graphene. The hybrid films demonstrate enhanced isotropic mechanical properties and strain sensitivity with a gauge factor of ∼3, together with a high stretchability of more than 20%. The enhanced electromechanical properties are attributed to the improved load transfer efficiency among CNTs by graphene hybridization, as confirmed by Finite Element Analysis (FEA). Biaxial strain sensors based on the hybridized G/CNT films have been applied for sensitive detection of both minute vibrations caused by sound waves and large deformations from finger bending. The sensors were further integrated into a tactile sensing array to map the spatial distribution of the surface pressures.

Wrought magnesium and Mg alloys are characterized by a strong basal texture and several slip and twin modes activated during plastic deformation. A hot rolled AZ31 plate was deformed in tension and compression along 4 directions at room temperature, and texture was investigated after e = 0.1 plastic strain by EBSD. The plastic deformation and deformed texture were simulated with the visco-plastic self-consistent twinning-detwinning model (VPSC-TDT), and compared with the experimental observations. {10–12} extension twins are responsible of the main texture variations, but {10–11} contraction and {10–11}{10–12} double twins were also observed in the 8 samples. The simulated main texture components are in good agreement with the measurements. Because the TDT scheme in its present form does not allows secondary twinning, some minor differences between the predicted and observed textures are observed. The strain anisotropy ( r -value) was over-estimated in in-plane tension, suggesting a very low threshold stress for basal slip.

Magnesium and its alloys are characterized by a strong basal texture, resulting in severe anisotropy at low temperature. To investigate the deformation behavior of a rolled magnesium alloy AZ31 at room temperature, uniaxial compression and tension experiments along four directions were performed and modeled using both the EVPSC-TDT and the VPSC-TDT models. The required threshold stress parameters were determined by curve fitting. Similar parameters were found to fit relatively well for all the experimental flow curves for both models. The predictions of the two models are also very similar beyond the elastic strain. The simulations reveal only a very limited increase with strain of the threshold stress for basal slip, which is favorable for basal texture development, whereas the threshold stresses for other deformation modes increase significantly. A discrepancy between experiments and simulations suggests that depending on loading condition strain accommodation between grains by basal slip varies in ease. A deformation-path dependent discrepancy between the modeled stress and the experimental curves is also found for the threshold stress for {10−12} twinning. This discrepancy is assumed to be related to the larger number of twin variants activated in tension as compared to compression, due to twin boundary hardening. A {10−12} twin-associated hardening, primarily on pyramidal slip and prismatic slip systems, evaluated to be about 15 MPa for both through thickness tension and in-plane compression, is included in the model via the use of a higher latent hardening modulus these slip systems by twinning.

Wrought magnesium and Mg alloys are characterized by a strong basal texture and several slip and twin modes activated at room temperature. These modes interact with each other, and the obstacles on each system associated with other deformation systems are empirically modeled via latent hardening coupling coefficients. { 10 1 ‾ 2 } tension twinning can be easily and largely activated, causing severe mechanical anisotropy and dramatic texture change. Twin nucleation and growth can also be influenced by slip-induced dislocations. To investigate how dislocations and twins affect { 10 1 ‾ 2 } twinning, a rolled magnesium alloy AZ31 was pre-deformed along different directions and reloaded in in-plane compression at room temperature. Elasto-visco-plastic self-consistent simulations including twinning, detwinning and secondary twinning show that the critical resolved shear stress for { 10 1 ‾ 2 } twinning is strongly increased by previous twins, moderately enhanced by basal and pyramidal slips, but additional prismatic dislocations have no effect on twinning. The present experiments and simulations demonstrate that latent hardening for { 10 1 ‾ 2 } by slip modes is much less than self-hardening.

The phase equilibrium of Mg–Cu–Ca ternary system at 350 °C were investigated using thirteen key samples. Scanning electron microscopy (SEM) equipped with energy-dispersive spectroscope (EDS) was employed to investigate equilibrium relationships and phase compositions in alloy samples. Powder X-ray diffraction (XRD) technique was used to analyze the crystal structures of new found phases. Two unreported ternary phases, P1 and Mg25-xCu75Cax were observed and investigated for the first time. The compound P1 has a narrow solid homogeneity ranged from about Mg25Cu35Ca40 to Mg30Cu30Ca40 (in at. %). The solid solubility limit of the compound Mg25-xCu75Cax was found to be 8.03 ≤ xCa ≤ 16.67 with constant value of about 75 at. % Cu at 350 °C. The 2θ of fourteen diffraction peaks of new phase P1 were determined to be 23.0°, 35.9°, 37.3°, 38.9°, 42°, 44°, 47°, 52.5°, 54°, 56.7°, 62.3°, 66.8°, 68.2° and 75.4°. The 2θ of ten diffraction peaks of the new compound Mg25-xCu75Cax were confirmed to be 20.5°, 21.2°, 34.7°, 35.7°, 42.3°, 43.3°, 44.8°, 47.3°, 50.5° and 74.5°. The maximum solid solubility of Ca in the terminal compound MgCu2 was found to be 8.83 at. % at 350 °C. Ternary maximum solid solubility of binary terminal compounds Mg2Ca, Mg2Cu, Cu5Ca and CuCa were less than 2 at. %. In addition, eight three-phase equilibrium relationships were determined in the present work.

In the present study, a pre-strained Mg AZ31 plate (7% cold rolling and 2% compression along the transverse direction (TD)) was annealed at 200 °C, 250 °C, 350 °C for 0.5 h and 3 h. An interesting annealing hardening phenomenon appears during recompression along the normal direction (ND). All the as-used annealing treatments increase the yield strengths by about 20–27 MPa. Microstructure examination shows that a large number of { 10 1 2 } twins in the pre-strained samples are completely removed by the annealing treatments, except that at 200 °C for 0.5 h. Disappearance of the pre-existing twins leads to a transition from a detwinning predominant deformation to a basal slip predominant one during ND-compression. This change of deformation mechanism accounts for the annealing hardening phenomenon.

Detwinning behavior of a strongly textured magnesium alloy AZ31 at different temperatures was investigated, with a focus on the effect of temperature on twin boundaries (TBs) migration. A hot extruded Mg alloy AZ31 rod was subjected to a 3% pre-compression along the extrusion direction (ED) to generate { 10 1 ¯ 2 } twins. Subsequent tensions along the ED at temperatures of 30 °C, 100 °C, 150 °C, 200 °C and 250 °C, respectively, were carried out to initiate detwinning. Mechanical behavior and microstructure evolution during detwinning deformation were examined. Our results show that the activation stress for { 10 1 ¯ 2 } TBs migration decreases with the increasing of temperature from 30 °C to 250 °C. Even at 250 °C, detwinning rather than non-basal slips dominates tension along the ED of pre-strained specimens. All strain hardening curves of detwinning deformation at temperatures of 30–250 °C contain three stages that often appear in a { 10 1 ¯ 2 } twinning predominant deformation. The length of Stage II is predominantly related to { 10 1 ¯ 2 } twin volume fraction. It is found that the peak hardening rate in Stage II decreases with increased temperature.

In this study, we investigated the biochemical mechanisms in the adult rat hippocampus underlying the relationship between a terrified-sound induced psychological stress and spatial learning. Adult male rats were exposed to a terrified-sound stress, and the Morris water maze (MWM) has been used to evaluate changes in spatial learning and memory. The protein expression profile of the hippocampus was examined using two-dimensional gel electrophoresis (2DE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and bioinformatics analysis. The data from the MWM tests suggested that a terrified-sound stress improved spatial learning. The proteomic analysis revealed that the expression of 52 proteins was down-regulated, while that of 35 proteins were up-regulated, in the hippocampus of the stressed rats. We identified and validated six of the most significant differentially expressed proteins that demonstrated the greatest stress-induced changes. Our study provides the first evidence that a terrified-sound stress improves spatial learning in rats, and that the enhanced spatial learning coincides with changes in protein expression in rat hippocampus.

Methyl-CpG binding protein 2 (MeCP2) has recently been characterized as an oncogene frequently amplified in several types of cancer. However, its precise role in gastric cancer (GC) and the molecular mechanism of MeCP2 regulation are still largely unknown. Here we report that MeCP2 is highly expressed in primary GC tissues and the expression level is correlated with the clinicopathologic features of GC. In our experiments, knockdown of MeCP2 inhibited tumor growth. Molecular mechanism of MeCP2 regulation was investigated using an integrated approach with combination of microarray analysis and chromatin immunoprecipitation sequencing (ChIP-Seq). The results suggest that MeCP2 binds to the methylated CpG islands of FOXF1 and MYOD1 promoters and inhibits their expression at the transcription level. Furthermore, we show that MeCP2 promotes GC cell proliferation via FOXF1-mediated Wnt5a/β-Catenin signaling pathway and suppresses apoptosis through MYOD1-mediated Caspase-3 signaling pathway. Due to its high expression level in GC and its critical function in driving GC progression, MeCP2 represents a promising therapeutic target for GC treatment., Highlights • MeCP2 inhibits FOXF1 and MYOD1 transcription by binding to their promoter regions. • MeCP2 promotes GC cell proliferation via FOXF1-mediated Wnt/β-Catenin signaling pathway. • MeCP2 suppresses GC cell apoptosis through MYOD1-mediated Caspase-3 signaling pathway. Gastric cancer is the fourth most common malignant cancer and the third most frequent cause of cancer-related deaths worldwide. The molecular mechanism underlying gastric carcinogenesis and progression is still unknown. Methyl-CpG binding protein 2 (MeCP2) has recently been characterized as an oncogene frequently amplified in several types of cancer. However, its precise role and the molecular mechanism of MeCP2 regulation in gastric cancer are largely unknown. Our results show that MeCP2 promotes gastric cancer cell proliferation via FOXF1-mediated Wnt5a/β-Catenin signaling pathway and suppresses cell apoptosis through MYOD1-mediated Caspase-3 signaling pathway. MeCP2 represents a promising therapeutic target for gastric cancer treatment.

The synergistic effect of Y and Nb addition on the long time isothermal and cyclic oxidation behaviors of Ti-45Al (6-9)Nb alloys containing 0.1-0.4 at.% Y was investigated in air at 900 degrees C. The results showed that the high temperature oxidation resistance was improved with an increase of Nb content. However, even 9 at.% Nb content was not sufficient to form the perfect Al2O3 layer. Scale spallation still occurred under hundreds of cyclic exposure. Y addition remarkably enhanced the long time oxidation resistance of high Nb containing TiAl alloys, and only a proper amount of Y addition could improve the long time oxidation resistance under both isothermal and cyclic oxidation. In this work, it was concluded that the principle of Y addition was choosing the minimum amount on the premise of meeting enough spallation resistance. Moreover, the optimum amount of Y changed regularly with the variation of Nb content. The reasonable addition of Y decreased from 0.4 at.% to 0.2 at.% with Nb content increasing from 6 at.% to 9 at.%. Based on synergistic effect of Y and Nb, the best oxidation resistance of alloys was achieved. (C) 2012 Elsevier Ltd. All rights reserved.

A series of Pd/SiO 2 and Pd–Ti/SiO 2 catalysts were prepared by the incipient wetness impregnation method. The catalytic performance for selective hydrogenation of acetylene to ethylene was measured under “high concentration acetylene”, “high space velocity” and “no dilution gas” conditions. The crystal structure and particle size of the catalysts were characterized by the X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), nitrogen physisorption using the BET method and transmission electron microscope (TEM). The results showed that the titanium oxide in Pd–Ti/SiO 2 catalyst was amorphous and the addition of Ti reduced the particle size of Pd significantly. Comparing to the Pd/SiO 2 catalyst, the ethylene yield increased from 64.1% to 88.3% under Pd–Ti/SiO 2 catalytic system.

Metabotropic glutamate receptors (mGluRs) regulate neurogenesis in brain, but the mechanisms remain unknown. In this study, we investigated the effect of mGluR5 on the proliferation of human embryonic neural stem/progenitor cells (NPCs), the expression of cyclin D1 and the activation of signaling pathways of mitogen-activated protein kinases (MAPKs). Results showed that mGluR5 agonist (S)-3,5-dihydroxyphenylglycine hydrate (DHPG) increased the proliferation of NPCs by increasing cell activity, diameter of neurospheres and cell division, while mGluR5 siRNA and antagonist 6-methyl-2-(phenylethynyl) pyridine hydrochloride (MPEP) decreased the NPC proliferation. The mRNA and protein expressions of cyclin D1 increased with DHPG treatment and decreased after siRNA or MPEP treatment. It was also found that activation of extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal protein kinase (JNK) signaling pathways were involved in the proliferation of NPCs. After DHPG treatment, p-ERK1/2 and p-JNK2 levels increased, and meanwhile p-p38 level decreased; but p-ERK1/2 and p-JNK2 levels decreased after siRNA or MPEP treatment, and p-p38 level increased. Our findings demonstrated that mGluR5 promoted the proliferation of human embryonic cortical NPCs and increased cyclin D1 expression with the changes in phosphorylation of MAPKs signaling pathways in vitro, suggesting a novel mechanism for pharmacological study of treatment for ischemic brain injury and neurodegenerative disorders.