NMR probe of suppressed bulk conductivity in the topological insulator Bi0.5Sb1.5Te3

The relaxation behavior in the topological insulator (TI) Bi_0.5Sb_1.5Te₃ has been investigated using ¹²⁵Te nuclear magnetic resonance spectroscopy. We systematically investigate the spin–lattice relaxation rate (1/T₁) in bulk electronic states with varying particle sizes. By analyzing the 1/T₁ relaxation behavior, we find that with decreasing particle sizes the electronic states in the bulk exhibit more topological insulating behavior, indicative of an increasing energy gap supported by higher thermal activation energy. Besides, the decreasing density of states at the Fermi level was observed in the massive Dirac electrons with decreasing particle size by analyzing the spin–lattice relaxation according to a theoretical model in this spin–orbit coupled system.

We investigated insulating behaviors in the bulk of the topological insulator Bi_0.5Sb_1.5Te₃ varying in particle size using ¹²⁵Te NMR spectroscopy, within the framework of a theoretical relaxation model of the Dirac electron system.     

Strong interfacial interactions induced a large reduction in lateral thermal conductivity of transition-metal dichalcogenide superlattices

van der Waals heterostructures formed by vertically stacking two-dimensional (2D) crystals can not only harness the already fascinating properties of their constituent monolayers but also extend them due to the coupled interlayer interactions. With their emerged interlayer and intralayer excitons, 2D transition metal dichalcogenides (TDMC) crystals and their heterostructures have drawn growing attention for the applications of nanoelectronics, optoelectronics and nanophotonics. Yet, there are few studies on how interlayer and interfacial interactions influence the thermal transport in TDMC heterostructures which is critical for heat management. In this work, we investigate the lateral and out-of-the-plane thermal conductivity (κ) of four prototype TDMC heterostructures (bilayer MoS₂ and WS₂, heterobilayer MoS₂/WS₂ and superlattice MoS₂/WS₂) by solving the phonon Boltzmann transport equation from first-principles. The calculated room-temperature lateral κ of bilayer MoS₂ and WS₂ are 61.13 W m⁻¹ K⁻¹ and 87.52 W m⁻¹ K⁻¹, respectively, in reasonable agreement with literature experiments. The weak interlayer interactions in the heterobilayer MoS₂/WS₂ help preserve the high lateral thermal transport (70.01 W m⁻¹ K⁻¹) of its constituent monolayer. In the superlattice MoS₂/WS₂, there exist strong interlayer and interfacial interactions between the alternating MoS₂ and WS₂ monolayer which reduce the lateral κ to be 7.22 W m⁻¹ K⁻¹ by a factor of 10. The greatly reduced lateral κ of the superlattice mainly arises from the low phonon relaxation time, which indicates the existence of strong interfacial anharmonic phonon scattering. This work aims at uncovering the physics of emerged thermal transport properties in TDMC heterostructures and helps advance their applications in heat management among nanoelectronics and optoelectronics.

The strong interfacial interactions in the superlattice MoS₂/WS₂ enhance phonon scattering and result in the ultralow lateral thermal conductivity.     

Fermi level tuning in modified Bi2Te3 system for thermoelectric applications

The techniques of size reduction and defect engineering have attracted great interest as an effective strategy for developing new and modified thermoelectric materials with high performance. Here, we investigated the thermoelectric properties of the Bi₂Te₃ system modified by Fermi level tuning through the methods of nanostructuring and doping. Band structure modification and Fermi level shift contribute to the better thermoelectric performance of the material. A minimum thermal conductivity of 0.72 W K⁻¹ was obtained at 440 K with a reduction of 50% as compared to the pristine sample. The improved transport properties along with considerably reduced thermal conductivity result in a two-fold improved figure of merit of 0.295 at 420 K for the nanostructured sample Bi_0.4Sb_1.6Te₃ over pristine Bi₂Te₃.

The thermoelectric properties of Bi₂Te₃ system can be modified by Fermi level tuning using the methods of nanostructuring and doping. Fermi level shift contribute to better thermoelectric performance of the material, leading to two-fold improvement in figure of merit.     

Assessing phase discrimination via the segmentation of an elemental energy dispersive X-ray spectroscopy map: a case study of Bi2Te3 and Bi2Te2S

The present case study critically assesses the efficacy of a previously proposed segmentation methodology as a means to discriminate phases via post-processing the image of an elemental map. In the Bi₂Te_2.5S_0.5 multiphase compound, the reference spectra of the Bi₂Te₃ and Bi₂Te₂S phases are distinct enough to effectively distinguish two phases during map acquisition. Since the counts of the sulphur-K peak in the X-ray emission data are significantly higher for Bi₂Te₂S compared to Bi₂Te₃, the segmentation methodology exploits this variation and enables successful phase discrimination via post-processing the image of the elemental map.

The present case study critically assesses the efficacy of a previously proposed segmentation methodology as a means to discriminate phases via post-processing the image of an elemental map.     

Development of pristine and Au-decorated Bi2O3/Bi2WO6 nanocomposites for supercapacitor electrodes

Pristine and Au-decorated Bi₂O₃/Bi₂WO₆ nanocomposites were synthesized via a facile hydrothermal method. Characterization techniques such as XRD, FESEM, HRTEM and XPS were used to explore the structural, morphological and electronic properties. Furthermore, electrochemical characterizations including cyclic voltammetry (CV), the galvanostatic charge–discharge (GCD) method, and electrochemical impedance spectroscopy (EIS) were performed to investigate the supercapacitance behaviour of the synthesized materials. Interestingly, the Au-decorated Bi₂O₃/Bi₂WO₆ nanocomposite showed a higher capacitance of 495.05 F g⁻¹ (1 M aqueous KOH electrolyte) with improved cycling stability (99.26%) over 2000 cycles, measured at a current density of 1 A g⁻¹, when compared to the pristine Bi₂O₃/Bi₂WO₆ composite (capacitance of 148.81 F g⁻¹ and good cycling stability (95.99%) over 2000 cycles at a current density of 1 A g⁻¹). The results clearly reveal that the decoration of the Bi₂O₃/Bi₂WO₆ composite with Au nanoparticles enhances its supercapacitance behaviour, which can be attributed to an increase in electrical conductivity, good electrical contact between the electrode and electrolyte, and an increase in effective area. The Au-decorated Bi₂O₃/Bi₂WO₆ nanocomposite can be considered as an electrode material for supercapacitor application.

Pristine and Au-decorated Bi₂O₃/Bi₂WO₆ nanocomposites were synthesized via a facile hydrothermal method, and find its application in supercapacitor.     

Enhancement of thermoelectric properties over a wide temperature range by lattice disorder and chemical potential tuning in a (CuI)y(Bi2Te3)0.95−x(Bi2Se3)x(Bi2S3)0.05 quaternary system

Bi₂Te₃-based compounds have received attention as thermoelectric materials for room-temperature cooling and waste heat recovery applications. With potential application prospects, quaternary compounds of Bi₂Te₃–Bi₂Se₃–Bi₂S₃ composites can be used for mid-temperature power generation under 500 °C. Herein, we investigated the thermoelectric properties of (CuI)_y(Bi₂Te₃)_0.95−x(Bi₂Se₃)_x(Bi₂S₃)_0.05 (x = 0.05, 0.2; y = 0.0, 0.003) compounds. Through X-ray diffraction and transmission electron microscopy, we confirmed that the lattice disorder in (Bi₂Te₃)_0.95−x(Bi₂Se₃)_x(Bi₂S₃)_0.05 (x = 0.2) was due to multiple element substitutions. Disorder carrier scattering induced the localized nature of electrical resistivity, as confirmed by variable range hopping at low temperature. The temperature-dependent Seebeck coefficient of (Bi₂Te₃)_0.95−x(Bi₂Se₃)_x(Bi₂S₃)_0.05 showed a carrier-type change from p- to n-type behaviour in the intermediate temperature range (525 K for x = 0.05 and 360 K for x = 0.2). Even though strong carrier localization increased electrical resistivity, resulting in degradation of the power factor and thermoelectric performance, when the chemical potential was increased to the conduction band minimum through CuI co-doping into the (CuI)_0.003(Bi₂Te₃)_0.95−x(Bi₂Se₃)_x(Bi₂S₃)_0.05 (x = 0.05, 0.2) compounds, the carriers were delocalized and showed n-type behaviour in the Seebeck coefficient. The temperature-dependent thermal conductivity shows the suppression of bipolar conduction behaviour. The simultaneous effect on carrier optimization through chemical potential tuning and lattice disorder caused a high ZT value of 0.85 at 523 K for CuI-doped (Bi₂Te₃)_0.75(Bi₂Se₃)_0.2(Bi₂S₃)_0.05, which was comparatively high for n-type thermoelectric materials in the mid-temperature range.

Temperature-dependent ZT values of (CuI)_y(Bi₂Te₃)_0.95−x(Bi₂Se₃)_x(Bi₂S₃)_0.05 (x = 0.05, 0.2; y = 0.0, 0.003) compounds compared with other related n-type compounds.     

Effect of Bi3+ ion on upconversion-based induced optical heating and temperature sensing characteristics in the Er3+/Yb3+ co-doped La2O3 nano-phosphor

The upconversion-based optical heating and temperature sensing characteristics are investigated in the Er³⁺/Yb³⁺/Bi³⁺ tri-doped La₂O₃ nano-phosphor synthesized through a solution combustion method. The structural measurements reveal an increase in lattice parameters and particles size of the phosphor on increasing the concentrations of Bi³⁺ ions. The energy dispersive spectroscopic (EDS) measurements confirm the presence of La, Er, Yb, Bi and O elements in the tri-doped phosphor. The absorption spectra show the large number of bands due to Er³⁺, Yb³⁺ and Bi³⁺ ions. The Er³⁺/Yb³⁺ co-doped phosphor gives strong green emission bands at 523 and 548 nm upon 976 nm excitation due to ²H_11/2 → ⁴I_15/2 and ⁴S_3/2 → ⁴I_15/2 transitions of Er³⁺ ion, respectively. The emission intensity of these bands is enhanced upto 15 times in the presence of Bi³⁺ ions. The emission intensities of the 523 and 548 nm bands vary non-linearly with the pump power. The fluorescence intensity ratio (FIR) of the thermally coupled 523 and 548 nm emission bands shows efficient optical heating in the tri-doped phosphor. The FIR of the 523 and 548 nm emission bands further varies with the increase in temperature of the phosphor. The relative temperature sensing sensitivity has been calculated to be 71 × 10⁻⁴ K⁻¹ at 450 K for the tri-doped phosphor. Thus, the Er³⁺/Yb³⁺/Bi³⁺ tri-doped La₂O₃ nano-phosphor may provide a platform to use it in the photonic devices, as an optical heater and temperature sensor.

The Er³⁺/Yb³⁺/Bi³⁺ tri-doped La₂O₃ nano-phosphor gives efficient induced optical heating and temperature sensing. This study is useful to understand these characteristics in different materials with various pump powers and temperatures.     

ApoE-2/E-3 ratio of very low density lipoprotein in diabetes mellitus

Apolipoprotein E (apoE) of very low density lipoprotein (VLDL) in 22 diabetic patients was analysed by the method of one-dimensional isoelectrofocussing (IEF). We modified the IEF-method of Kashyap et al. by which apoE isoproteins were easily and accurately determined. The measurement of apoE-2/E-3 ratio was useful for determining apoE phenotypes. In 17 of 22 diabetics apoE phenotype was E3/3, while three patients showed E2/3 and two showed E3/4. ApoE-2/E-3 ratio was reduced from 0.91 +/- 0.07 to 0.73 +/- 0.04 (p less than 0.05) by the one month-period treatment in 10 insulin required diabetics. The ratio was also reduced from 1.06 +/- 0.14 to 0.89 +/- 0.09 (p less than 0.2) in 10 non-insulin required diabetics. The reduction in apoE-2/E-3 ratio was caused by an increase in apoE-3 band and a decrease in apoE-2 band which might be attributed to the changes in the sialic acid-content of isoproteins on the one-dimensional IEF method. Therefore, apoE phenotypes in diabetic patients should be determined when their diabetic state is improved.     

Insights into the photocatalytic performance of Bi2O2CO3/BiVO4 heterostructures prepared by one-step hydrothermal method

This paper describes the synthesis of Bi₂O₂CO₃/BiVO₄ heterostructures through a one-step method based on the difference in solubility between two semiconductors that possess a metal in common. The as-synthesized Bi₂O₂CO₃/BiVO₄ heterostructures were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ physisorption, X-ray photoelectron spectroscopy (XPS) and time resolved photoluminescence spectroscopy (TRPL). The role of the heterojunction formed was evaluated by methylene blue (MB) dye and amiloride photodegradation. The formation of the heterostructure was observed indirectly by the great increase in the thermal stability of the Bi₂O₂CO₃ phase when compared to its pure phase. The amount of heterojunctions formed between the Bi₂O₂CO₃ and BiVO₄ was tuned by vanadium precursor concentration. The proposed strategy was efficient for obtaining Bi₂O₂CO₃/BiVO₄ heterostructures with enhanced photocatalytic performance when compared to their isolated phases, MB and amiloride photodegradation occurred mainly by the action of ˙OH radicals, i.e. by an indirect mechanism. Based on TRPL spectroscopy and VB-XPS results, an enhancement of photoactivity related to an increase in the spatial separation of photo-generated electron/hole pairs was observed due to the formation of a type-II heterostructure.

A novel visible-driven heterojunction of Bi₂O₂CO₃/BiVO₄ was prepared by an efficient hydrothermal self-sacrificial synthesis method based on the difference in solubility.     

Hydrogen induced interface engineering in Fe2O3–TiO2 heterostructures for efficient charge separation for solar-driven water oxidation in photoelectrochemical cells

Semiconductor heterostructure junctions are known to improve the water oxidation performance in photoelectrochemical (PEC) cells. Depending on the semiconductor materials involved, different kinds of junctions can appear, for instance, type II band alignment where the conduction and valence bands of the semiconductor materials are staggered with respect to each other. This band alignment allows for a charge separation of the photogenerated electron–hole pairs, where the holes will go from low-to-high valance band levels and vice versa for the electrons. For this reason, interface engineering has attracted intensive attention in recent years. In this work, a simplified model of the Fe₂O₃–TiO₂ heterostructure was investigated via first-principles calculations. The results show that Fe₂O₃–TiO₂ produces a type I band alignment in the heterojunction, which is detrimental to the water oxidation reaction. However, the results also show that interstitial hydrogens are energetically allowed in TiO₂ and that they introduce states above the valance band, which can assist in the transfer of holes through the TiO₂ layer. In response, well-defined planar Fe₂O₃–TiO₂ heterostructures were manufactured, and measurements confirm the formation of a type I band alignment in the case of Fe₂O₃–TiO₂, with very low photocurrent density as a result. However, once TiO₂ was subjected to hydrogen treatment, there was a nine times higher photocurrent density at 1.50 V vs. the reversible hydrogen electrode under 1 sun illumination as compared to the original heterostructured photoanode. Via optical absorption, XPS analysis, and (photo)electrochemical measurements, it is clear that hydrogen treated TiO₂ results in a type II band alignment in the Fe₂O₃–H:TiO₂ heterostructure. This work is an example of how hydrogen doping in TiO₂ can tailor the band alignment in TiO₂–Fe₂O₃ heterostructures. As such, it provides valuable insights for the further development of similar material combinations.

Approximate energy band diagram and charge transfer mechanism for the Fe₂O₃–TiO₂ photoanode (left) and Fe₂O₃–H:TiO₂ photoanode (right) with external applied anodic potential under illumination.     

Composition-induced phase evolution and high strain response in Ba(Zn1/3Nb2/3)O3-modified (Bi0.5Na0.5)TiO3-based lead-free ferroelectrics

In this work, a paraelectric complex perovskite Ba(Zn_1/3Nb_2/3)O₃ (BZN) was introduced into the morphotropic boundary composition (Bi_0.5Na_0.5)_0.93Ba_0.07TiO₃ (BNBT) to modulate the phase structure and electrical properties as well as the field-induced strain behavior. Using a columbite route, the ceramics with pure perovskite structure were successfully fabricated. The structure and electrical measurements showed that the introduction of BZN into BNBT results in the decrease of the rhombohedrality 90-γ, and promotes the evolution from ferroelectric to antiferroelectric (AFE) relaxor. Besides, the introduction of BZN induces the volume increase and dimension reduction of the nanosized AFE relaxor domains. A large field-induced strain of 0.39% with good stability against frequency, field, and temperature was obtained at the BNZ addition of composition x = 0.01, which locates at the critical composition boundary between ferroelectric state and AFE relaxor state.

Addition of 1.0 mol% Ba(Zn_1/3Nb_2/3O₃) into (Bi_0.5Na_0.5)_0.93Ba_0.07TiO₃ results in the decrease of the rhombohedrality and the evolution from ferroelectric to antiferroelectric relaxor, thus leads to the emergence of a large field-induced strain of 0.39%.     

The combination of Al2O3 and BN for enhancing the thermal conductivity of PA12 composites prepared by selective laser sintering

A powder-based 3D printing technology, selective laser sintering (SLS), is a novel strategy of manufacturing complex components with specially tailored properties, including mechanical properties, as well as thermal and electrical conductivity. In this study, the effect of incorporating Al₂O₃ particles and BN plates on the thermal conductivity of PA12 composites was investigated. PA12 composite powders, which can be well applied to SLS, were prepared via a two-step approach to mixing. Morphology characteristics demonstrated that the fillers dispersed uniformly in the PA12 matrix, as expected. With 35 wt% Al₂O₃ and 15 wt% BN hybrid fillers, the tensile strength had the potential to reach 25.7 MPa, while the thermal conductivity could reach 1.05 W m⁻¹ K⁻¹, 275% higher than that of pure PA12. In addition, the study investigated the effects of filler content on the thermal stability and mechanical properties whilst analysing the melting and crystallisation behaviours of SLS components. The results demonstrate that these composites have favourable thermal stability and exhibit no severe deterioration in mechanical properties. The PA12 composites prepared in this work therefore illustrated vast potential in thermal management materials.

The introduction of hybrid fillers in SLS technology is an effective method for the manufacture of thermally conductive polymer composites with high thermal conductivity, complex structures and good mechanical properties.     

As2O3/TRAIL诱导的骨髓增生异常综合征原始细胞系MDS-L的生物学变化

目的　观察骨髓增生异常综合征 (MDS)髓系原始细胞系MDS L经不同剂量和不同时间的三氧化二砷 (As2 O3 )和肿瘤坏死因子相关凋亡诱导配体 (TRAIL)处理后的生物学变化。方法　体外培养的MDS L细胞经 9种不同浓度的药物及药物组合 (As2 O3 :1,2 ,5mmol/L ;TRAIL :10 0 ,30 0 ,5 0 0 μg/L ,As2 O3 1mmol/L TRAIL 10 0 μg/L ;As2 O3 2mmol/L TRAIL 30 0 μg/L ;As2 O3 5mmol/L TRAIL 5 0 0 μg/L)处理 ,在 2 4 ,4 8和 72h后收获细胞。对未经药物处理的细胞和药物处理后收获的细胞均进行流式细胞仪检测细胞凋亡 ;药物处理 2 4h后的细胞再经体外培养 18d后作形态学观察 ,同时以流式细胞仪检测CD34 细胞变化 ,检测药物的促分化作用 ;RT PCR检测P15 ink4b mRNA表达 ;甲基化特异性PCR(MethylationspecificPCR ,Msp)检测P15 ink4bDNA甲基化状态 ;DAB免疫酶标检测P15 ink4b蛋白水平表达。结果　不同的药物组合均可诱导细胞发生凋亡 ,药物处理 4 8h凋亡达高峰 (约 2 5 % ) ,72h时仍有约9%的细胞凋亡。药物处理 (尤其是As2 O3 TRAIL)导致细胞明显的形态学分化 ,而TRAIL能显著降低CD34 细胞比率。未经处理的MDS L细胞基本不表达P15 ink4b,并伴有明显的DNA甲基化。药物处理后P15 ink4b表达增强 ,并伴有DNA去甲基     

Upregulations of P2X3 and ASIC3 involve in hyperalgesia induced by cisplatin administration in rats

The role of ion channels expressed in sensory neurons on mechanical and thermal hyperalgesia was examined in a rat model of cisplatin-induced peripheral neuropathy. The rats were injected with 3 mg/kg of cisplatin intraperitoneally once per week for five consecutive weeks. The von Frey test, pin-prick test and plantar test were performed to examine any noxious sensitivity of the skin. The Randall–Selitto test of the gastrocnemius muscle (GM) and the measurement of grip forces were performed to quantify muscle hyperalgesia. Coordination/motor was assessed by Rota-rod testing. Expressions of the ion channels TRPV1, TRPV2, P2X₃ and ASIC3 were examined in dorsal root ganglion (DRG) neurons and the muscle afferent neurons innervating GM. Effects of antagonists against either P2X₃ or ASICs on behavioral responses were evaluated. Mechanical hyperalgesia and allodynia of both skin and muscle were observed in cisplatin-treated animals. Expressions of TRPV2, P2X₃, and ASIC3 increased in all DRG neurons. In addition, expressions of P2X₃ and ASIC3 also increased in muscle afferent neurons in DRGs. Antagonists against P2X_3,2/3 and ASICs showed a suppressive effect on both skin and muscle hyperalgesia induced by cisplatin administration. Upregulation of TRPV2, P2X₃, and ASIC3 may play important roles in the mechanical hyperalgesia induced by cisplatin. Furthermore, cisplatin treatment also induced muscle hyperalgesia in muscle afferent neurons in connection with the upregulation of P2X₃ and ASIC3.     

Fabrication of a ceramic/metal (Al2O3/Al) composite by 3D printing as an advanced refractory with enhanced electrical conductivity

Fused deposition modelling (3D) printing is used extensively in modern fabrication processes. Although the technique was designed for polymer printing, it can now be applied in advanced ceramic research. An alumina/aluminum (Al₂O₃/Al) composite refractory can be fabricated by mixing metallic aluminum in a polymer to form an Al/polymer composite filament. The filament can be printed via a regular thermoplastic material extrusion printer with no machine modification. In this study, Al/polymer composite samples were printed in a crucible shape and sintered at different temperatures to form Al₂O₃/Al composite refractory specimens. The sintered samples were examined via several analytical techniques such as scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, compressive testing, hardness testing, XPS, and Hall measurement. Unlike other ceramic printing techniques that require expensive 3D printing machines and a very high temperature furnace (above 1500 °C) for post processing, this study demonstrates the viability of fabricating refractory items using a cost-effective fused deposition modelling 3D printer and a low temperature furnace (900 °C). The samples did not disintegrate at 1400 °C and were still sufficiently electrically conductive for advanced refractory applications.

An Al₂O₃/Al composite is fabricated by the 3D printing, sintering, and calcination processes that can be used in refractory applications.     

Preparation and study of characteristics of LiCoO2/Fe3O4/Li2B2O4 nanocomposites as ideal active materials for electrochemical hydrogen storage

The nanocomposites of LiCoO₂/Fe₃O₄/Li₂B₂O₄ were designed by the Pechini route using different fuels for the optimization of their morphology and structure. Compared to other fuels, citric acid can act as both an ideal fuel and a capping agent. The ratio of the EG : H₂O mixture is another parameter, which was studied in terms of its effects on the structural characterization. The optimized sample with a rod shape was selected to compare with the bulk sample through electrochemical hydrogen storage capacity. The discharge capacity for rod-shaped nanocomposites measured was 1284 mA h g⁻¹. However, the discharge capacity for the bulk morphology was calculated to be about 694 mA h g⁻¹. The magnetic, electrochemical and structural analyses were performed to investigate the properties of LiCoO₂/Fe₃O₄/Li₂B₂O₄ nanocomposites.

To the best of our knowledge, for the first time, the effects of LiCoO₂/Fe₃O₄/Li₂B₂O₄ nanocomposites as a favorable hydrogen capacitor were investigated to enhance hydrogen storage performance.     

Habituation deficits induced by metabotropic glutamate receptors 2/3 receptor blockade in mice: reversal by antipsychotic drugs

Cortical metabotropic glutamate receptors (mGluRs) seem to be involved in habituation of simple stimulus-bound behaviors (e.g., habituation to acoustic startle or odor-elicited orienting response). Habituation deficits may contribute to the cognitive symptoms of schizophrenia. In the present study, male NMRI mice were injected with mGluR2/3 antagonist 2S-2-amino-2-(1S,2S-2-carboxycyclopropyl-1-yl)-3-(xanth-9-yl)propanoic acid (LY-341495) 30 min before being placed into novel arenas for automatic motor activity recording (2-h sessions). Administration of LY-341495 (1-10 mg/kg s.c.) dose-dependently prevented the habituation of the locomotor activity. Effects of LY-341495 (10 mg/kg) were fully and dose-dependently reversed by i.p. administration of haloperidol (0.03-0.3 mg/kg), clozapine (1-10 mg/kg), risperidone (0.01-0.1 mg/kg), olanzapine (0.3-3 mg/kg), aripiprazole (1-10 mg/kg), and sulpiride (3-30 mg/kg), each of which was given 15 min before the test. Effects of antipsychotic drugs were observed at the dose levels that did not affect spontaneous motor activity. LY-341495-induced delayed hyperactivity was also partially attenuated by lithium (50-200 mg/kg), amisulpride (1-10 mg/kg), and the selective dopamine D3 antagonist trans-N-[4-[2-(6-cyano-1,2,3,4-tetrahydroisoquinolin-2-yl)ethyl]cyclohexyl]-4-quinolinecarboxamide (SB-277011A; 3-30 mg/kg). Application of diazepam, imipramine, or several agonists and/or antagonists acting at various receptors that are thought to be relevant for antipsychotic treatment [e.g., 5-hydroxytryptamine (5-HT)(2A), 5-HT(3), and 5-HT(6) antagonists; 5-HT(1A) agonist; D4 antagonist; CB1 antagonist; ampakines; and glycine transporter inhibitor) had no appreciable effects. Thus, behavioral deficits induced by mGluR2/3 blockade (such as delayed motor hyperactivity) are selectively reversed by clinically used antipsychotic drugs.     

Strong correlation between flux pinning and epitaxial strain in the GdBa2Cu3O7−x/La0.7Sr0.3MnO3 nanocrystalline heterostructure

The effect of magnetic flux pinning is investigated in GdBa₂Cu₃O₇ (GdBCO) thin films with two different types of ferromagnetic La_0.7Sr_0.3MnO₃ (LSMO) buffers (nanoparticles and a layer) deposited on an STO substrate. Magnetization analyses reveal the presence of multiple flux pinning mechanisms responsible for the improvement in the critical current density of GdBCO films. While core pinning becomes a dominant pinning mechanism in GdBCO films with LSMO nanoparticles, a hybrid effect of magnetic-volume and core-point pinning is observed in GdBCO films with LSMO layers. Examinations of local structures for both LSMO and GdBCO using extended X-ray absorption fine structure spectroscopy (EXAFS) exhibit a close relation between the parameters in the pinning force scaling and the length ratio of the Mn–O bond to the Cu–O bond. This result implies that the origin of core pinning is probably attributed to epitaxial strain induced by lattice mismatch between LSMO and GdBCO. Therefore, an appropriate strain state of LSMO is required for an effective operation of magnetic pinning.

The effect of magnetic flux pinning is investigated in GdBa₂Cu₃O₇ (GdBCO) thin films with two different types of ferromagnetic La_0.7Sr_0.3MnO₃ (LSMO) buffers (nanoparticles and a layer) deposited on an STO substrate.     

Intrinsic asymmetric ferroelectricity induced giant electroresistance in ZnO/BaTiO3 superlattice

Here, we combine the piezoelectric wurtzite ZnO and the ferroelectric (111) BaTiO₃ as a hexagonal closed-packed structure and report a systematic theoretical study on the ferroelectric behavior induced by the interface of ZnO/BaTiO₃ films and the transport properties between the SrRuO₃ electrodes. The parallel and antiparallel polarizations of ZnO and BaTiO₃ can lead to intrinsic asymmetric ferroelectricity in the ZnO/BaTiO₃ superlattice. Using first-principles calculations we demonstrate four different configurations for the ZnO/BaTiO₃/ZnO superlattice with respective terminations and find one most favorable for the stable existence of asymmetric ferroelectricity in thin films with thickness less than 4 nm. Combining density functional theory calculations with non equilibrium Green''s function formalism, we investigate the electron transport properties of SrRuO₃/ZnO/BaTiO₃/ZnO/SrRuO₃ FTJ and SrRuO₃/ZnO/BaTiO₃/SrRuO₃ FTJ, and reveal a high TER effect of 581% and 112% respectively. These findings provide an important insight into the understanding of how the interface affects the polarization in the ZnO/BaTiO₃ superlattice and may suggest a controllable and unambiguous way to build ferroelectric and multiferroic tunnel junctions.

We combine the piezoelectric wurtzite ZnO and the ferroelectric (111) BaTiO₃ as a hexagonal closed-packed structure and report a systematic study on the ferroelectric behavior induced by the interface and the transport properties between electrodes.     

骨形态发生蛋白2诱导C3H10T1/2细胞成骨分化中长链非编码RNA的作用

背景：人类长链非编码RNA是现今的研究热点,已有研究报道其在肿瘤发生中的作用机制,但其在成骨分化方面的机制并不明确。目的：观察人类长链非编码RNA在经骨形态发生蛋白2诱导小鼠C3H10T1/2细胞成骨分化中的作用,并探讨其分子机制。方法：首先进行碱性磷酸酶染色和成骨指标基因检测。对C3H10T1/2细胞在骨形态发生蛋白2诱导下的成骨分化过程长链非编码RNA表达变化进行芯片分析。采用高通量测序比较骨形态发生蛋白2诱导组和未经骨形态发生蛋白2诱导组的表达变化,筛选出表达下降的基因。过表达相应长链非编码RNA后观察对骨形态发生蛋白2诱导成骨分化的影响。结果与结论：骨形态发生蛋白2诱导C3H10T1/2细胞导致碱性磷酸酶活性增加。骨形态发生蛋白2诱导72 h后,碱性磷酸酶、Id1、骨钙素、Runx2、sp7表达上升（P〈0.05）。未诱导C3H10T1/2细胞与骨形态发生蛋白2诱导细胞芯片杂交后结果比较,下降达1.5倍的长链非编码RNAs有24条,其中只有AK035085有内含子。与未过表达AK035085的对照组相比,骨形态发生蛋白2诱导72 h后AK035085过表达的C3H10T1/2细胞碱性磷酸酶、Id1、骨钙素、Runx2、sp7表达均下降（P〈0.05）。提示骨形态发生蛋白2可刺激C3H10T1/2细胞发生成骨分化,AK035085可能对C3H10T1/2细胞的成骨分化存在抑制作用。