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Ba 0.70 Ca 0.30 Ti 1- x (Nb 0.5 Fe 0.5) x O 3 lead-free ceramics (abbreviated as BCTNF x , x = 0–0.12) were prepared by solid-state reaction method. The influence of B-site (Fe 0.5 Nb 0.5)4+ substitution on phase structure, microstructure, dielectric, ferroelectric and piezoelectric properties of Ba 0.70 Ca 0.30 TiO 3 ceramics were systematically studied. The BCTNF x ceramics consist of diphasic tetragonal (T) and orthorhombic (O) phases at x = 0–0.04, pseudocubic (PC) and O phases at x = 0.05–0.08, cubic (C) and O phases at 0.08 < x ≤ 0.12. Increase of (Fe 0.5 Nb 0.5)4+ doping improves sinterability, depresses the ferroelectric - paraelectric phase transition temperature (T m) monotonically from 128 °C at x = 0 to -86 °C at x = 0.12, induces enhanced relaxor behavior and weakens piezoelectric properties. The room temperature relative dielectric constant (ε r) and dielectric loss tangent (tan δ) increase with increasing x and reach the maximum values of 4869 and 0.06 respectively at x = 0.06. Whereas the average grain size (abbreviated as AGS), ferroelectric properties and electric field induced strain increase significantly by introducing 2.0 mol% B-site complex cations (Fe 0.5 Nb 0.5)4+ into Ba 0.70 Ca 0.30 TiO 3 ceramics. The BCTNF0.02 ceramics achieve optimal electrical properties with ε r = 1268, tan δ = 0.03, T m = 102 °C, P max = 12.8 μC/cm2, P r = 6.1 μC/cm2, E C = 6.0 kV/cm, d 33 = 117 pC/N, k p % = 0.18%, Q m = 236, bipolar S max % = 0.20%, unipolar S max % = 0.16% and d 33 ∗ = 314 pm/V. The variation of electrical properties of BCTNF x ceramics is attributed to the combined action of grain size effect, phase transition, weakness of octahedral distortion, clamping effects of the internal bias electric field E i on domain wall motion induced by B-site cations (Fe 0.5 Nb 0.5)4+ displacement. [ABSTRACT FROM AUTHOR]

Abstract Chronic pancreatitis is characterized by pancreatic fibrosis, associated with excessive activation of pancreatic stellate cells (PSCs) and increased expression of transforming growth factor-β1 (TGF-β1). Recently, our studies have shown that autophagy inhibitor could inhibit PSCs activation and reduce collagen secretion. Saikosaponin d (SSd), the major active component of bupleurum falcatum (a medicinal plant), has anti-fibrosis effects in liver. However, it is unclear whether SSd has a role in pancreatic fibrosis. This study aimed to investigate the effect of SSd on the autophagy and activation of PSCs in vivo and in vitro. In vivo, a rat chronic pancreatitis model was induced by intravenous injection of dibutyltin dichloride. SSd was administered at a dose of 2.0 mg/kg body weight per day by gavage. After 4 weeks, the pancreas was collected for histological and molecular analysis. In vitro, PSCs were isolated and cultured for treatment with different dosages of SSd. The results showed that SSd inhibited PSCs autophagy and activation while also reducing extracellular matrix (ECM) formation and pancreatic damage. SSd inhibited autophagy through activating the PI3K/Akt/mTOR pathway. SSd also promoted degradation of ECM with an increasing ratio of MMPs/TIMPs and suppressed the TGF-β1/Smads pathway. From these results, we concluded that SSd prevents pancreatic fibrosis by reducing autophagy of PSCs through PI3K/Akt/mTOR pathway, which has crosstalk with the TGF-β1/Smads pathway. Highlights • Saikosaponin d improved pancreatic damage induced by DBTC in rat model. • Saikosaponin d inhibited PSCs activation and ECM formation in pancreas. • Saikosaponin d inhibited PSCs activation through reducing autophagy of PSCs. • Saikosaponin d repressed autophagy through activating the PI3K/Akt/mTOR signalling pathway in PSCs. [ABSTRACT FROM AUTHOR]

Highlights: [•] The effects of Mn doping on structures, electric, magnetic, and magnetocapacitive properties of the 0.33Ba0.70Ca0.30TiO3–0.67BiFeO3 + x wt%MnO2 (BCT-67BF:Mn100x, x =0–0.6) ceramics have been intensively investigated. [•] The BCT-67BF:Mn100x ceramics with x =0–0.6 have diphasic tetragonal–rhombohedral phases. Mn doping improves the densification and significantly decreases the grain size. [•] As x increases, the relaxor degree increases, the ferroelectricity and piezoelectricity weaken monotonically, while the magnetism enhances firstly, reaching the maximum near x =0.5, and then decreases. [•] The room temperature relative dielectric constant shows an obvious increase with increasing applied magnetic fields (H), the magnetocapacitive coefficient (ε r(H)− ε r(0))/ε r(0) decreases with increasing Mn content, from 2.96% for x =0 – 0.86% for x =0.6 . [ABSTRACT FROM AUTHOR]

Lead-free piezoelectric ceramics of Ba0.70Ca0.30Ti1−x Fe x O3 (x=0–0.03) have been synthesized by a conventional solid state reaction method. The influence of Fe content on the microstructure, phase transition, dielectric, ferroelectric, and piezoelectric properties is investigated systematically. The ceramics with x≤0.02 are diphasic composites of tetragonal Ba0.80Ca0.20TiO3:Fe and orthorhombic Ba0.07Ca0.93TiO3:Fe solid solutions. The tetragonal phase is gradually suppressed as x increases, the ceramic with x=0.03 is found to have diphasic pseudocubic and orthorhombic phases. And the grain size is dependent on Fe content significantly. Introduction of Fe at B-sites improves the densification and decreases the sintering temperature. As x increases from 0 to 0.03, the room temperature relative dielectric permittivity enhances, dielectric loss decreases, and the Curie temperature decreases monotonically from 128°C to 58°C. However, the ferroelectricity enhances slightly and reaches the maximum near x=0.005, and then weakens with increasing x. On the other hand, the piezoelectric coefficient (d 33) and the electromechanical coupling coefficient (k p ) decrease simultaneously with increasing x, whereas the mechanical quality factor (Q m ) increases significantly. The structure–electrical properties relationship is discussed intensively to give more information on (Ba,Ca)TiO3-based lead-free piezoelectric ceramics. [ABSTRACT FROM AUTHOR]

Abstract: The effects of sintering temperature and poling conditions on the electrical properties of tetragonal and orthorhombic diphasic Ba0.70Ca0.30TiO3 (BCT) lead-free ceramics have been systematically investigated. On the one hand, with increasing sintering temperature from 1270°C to 1400°C, the bulk density increases monotonically and the Curie temperature keeps almost constant with the value of ∼120°C, whereas the grain size, the maximum relative dielectric constant, room temperature polarization reach the maximum values for samples sintered at 1340°C. On the other hand, it is found that the piezoelectric property depends on poling electric field and poling temperature significantly. An enhanced piezoelectric behavior of d 33=126pC/N, k p =0.29, and Q m =588 is obtained for the BCT ceramics poled at 100°C with 30kV/cm field for 20min. The aging behavior of the piezoelectric property is also investigated. [Copyright &y& Elsevier]

Abstract Objective The inhibition of Aluminum (Al)-induced root tip cell elongation is a major cause of plant root elongation suppression. The inhibition of root tip cell elongation is caused by a disruption of cell wall component metabolism, growth signaling, or cellular damage. The aim of this study was to identify the proteins involved in the metabolism of the root cell wall components under Al stress in the Al-tolerant wheat ( Triticum aestivum L.) cultivar ET8. Methods Differentially expressed proteins of Al-tolerant wheat roots were screened via isobaric tags for relative and absolute quantification (iTRAQ). Furthermore, their expression changes were detected via RT-PCR analysis. The contents of major components of the cell wall and their changes in metabolic enzyme activities were also investigated. Results A total of 97 differentially expressed proteins from Al-tolerant wheat roots were screened and nine of these 97 proteins were root cell wall component related. The known nucleic acid sequences of proteins were 14-3-3 protein, the plasm membrane (PM) H+-ATPase, phospholipase D, peroxidase, and glycosyltransferase. For 14-3-3 protein, phospholipase D and peroxidase, the protein expression and mRNA expression were consistent with Al-treatment; however, for PM H+-ATPase and glycosyltransferase, the protein expression and mRNA expression were inconsistent under Al-stress. Furthermore, both cellulase activity and callase activity were down-regulated by Al stress, while the phenylalanineammonialyase (PAL), cinnamyl alcohol dehydrogenase (CAD), and peroxidase (POD) activities were up-regulated. Furthermore, the PM H+-ATPase activity was decreased in response to Al stress. In addition, the contents of callose, cellulose, lignin, and H 2 O 2 varied significantly. Conclusions The cell wall components, relative metabolism enzymes activity, and gene expression also changed followed by protein expression changed in response to Al stress. The results suggest that Al stress leads to marked variations in metabolic enzyme activity, carbohydrate content, followed by changes of root cell components in wheat roots. Highlights • Differently expressed proteins related to root cell wall components metabolism under Al stress were screened by iTRAQ. • Al stress leads to marked variations in root cell wall metabolic enzyme activity. • Root cell wall components was changed by Al stress [ABSTRACT FROM AUTHOR]