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In this study, PbZr0.52Ti0.48O3/BaTiO3 (PZT/BTO) multilayers with varying layer fractions were deposited on Pt/Ti/SiO2/Si substrates by sol-gel process. The films were characterized by X-ray diffraction and scanning electron microscopy (SEM). The result shows that there exists a dielectric enhancement when the BTO layer fraction x is around 0.5, and at this fraction, the dielectric constant of PZT/BTO is 590 at 100 kHz, which is far more than that of monolithic PZT or BTO films (478 and 284, respectively). The thermodynamic analysis shows that the measured dielectric constant is close to the simulation values when x closes to 0.5, otherwise it better consists with the series connection calculation values. The result indicates that the internal field resulting from the polarization mismatch between two ferroelectric layers contributes to the enhancement of PZT/BTO heterogeneous thin films.

SnO2-based varistor material was fabricated by doping of CoO, Nb2O5, Cr2O3, and Y2O3 or Ho2O3. The microstructure, nonlinear I-V characteristic and surge current performances have been investigated. The average grain boundary voltage of the obtained materials is close to that of ZnO varistors. Similar to Cr3+, Y3+ or Ho3+ acts as the acceptor in the grain boundaries and the depletion layers. Moderate co-doping Y2O3 or Ho2O3 with Cr2O3 is helpful to improve the electrical performances and to prevent poor densification. The obtained optimal samples with a diameter of about 14 mm have a nonlinear coefficient (α) of about 60, threshold electric field (Eb) of about 380 V/mm, and the withstanding peak current of 8/20 μs wave is about 2400 A. Higher surge current will cause failure but no visual damage happen. This kind of failure mode is helpful for safety use of varistors.

Lead-free piezoelectric ceramics (Bi0.5Na0.5)0.94(Ba1-xSrx)0.06TiO3 (abbreviated as BNBST-100x, with x ranges from 0.02 to 0.1) have been investigated. Effects of amount of Sr-substitution on the electrical properties and crystal structure of the ceramics were studied. The BNBST-100x ceramics sintered at 1200°C for 2h in air have high density around 5.69~5.75g/cm3. X-ray diffraction (XRD) analysis shows that all of the BNBST-100x ceramics have pure perovskite structure. At high amount level of Sr-substitution, the crystal structure of the samples changes from rhombohedral to tetragonal symmetry. Piezoelectric and dielectric measurements reveal that Sr-substitution amount within a certain range will lead to the increase of piezoelectric coefficient (d33), electromechanical coupling factor (kp), and relative dielectric constant (ε33 T/ε0). At 6 mol% Sr-substitution level, the d33 and kp of the ceramics reach maximum, with values of 168 pC/N and 34%, respectively.

The anti-reducing sintering of (Ca,Sr,Ba)TiO3-based dielectrics was achieved by the cooperating effect of Mn2+, Ca2+, Mg2+, Dy3+ and Yb3+. A small quantity of Zr4+ partly substitution for Ti4+ can improve the temperature dependence of dielectric constant. But ZrO2 will also reduce the solid solubility of BaTiO3-SrTiO3-CaTiO3 ternary system, and may cause phase separation. The separated ferroelectric phase increases the capacitance change under DC bias. Non-reducible (Ca,Sr,Ba)(Ti,Zr)O3-based dielectrics with single orthorhombic phase of perovskite structure was obtained. The dielectric and DC bias properties are: .C/C (DC bias: 1.5kV/mm)

A lead-free piezoelectric ceramic ternary system based on (Bi0.5Na0.5)TiO3 (BNT)-(Bi0.5 K0.5)TiO3(BKT)-BaTiO3(BT) near the morphotropic phase boundary (MPB) between the tetragonal and rhombohedral phases has been investigated. The samples were prepared by a conventional sintering technique. Piezoelectric properties, dielectric properties and microstructures of BNT-BKT-BT lead-free piezoelectric ceramic were studied. The X-ray diffraction (XRD) patterns show that the ceramics possess a single-phase perovskite structure. The measurements of piezoelectric properties reveal that this system has a relatively high piezoelectric performance: the piezoelectric constant d33 reached to 178pC/N and planar electromechanical coupling factor kp enhanced to 0.325. The BNT-BKT-BT ternary system ceramics could be well sintered at 11500C with a high-density ratio of more than 95% of the theoretical density.

The voltage response of ZnO varistors to 8/20 µs surge current was investigated. The observed frontal spikes on the residual voltage waveforms are caused by the ignition gap, and no frontal spike was observed when a thyristor was used as the discharge trigger. The rear part of the waveform is determined by the damping coefficient of the RLC-circuit. Near the critical point, the residual voltage waveform changes from non-oscillating attenuation modes to distinct across zero oscillating modes along with the increase of the peak current, but there will be no oscillation happen when a thyristor is used as the discharge trigger. The residual voltage peak is not synchronized with the current peak, and the voltage peak is leading, implying that the ZnO varistor appears to be inductive. According to the experiment results, it can be reasonably explained that the voltage peak leading phenomenon is attributed to the transient skin effect of the varistor materials.

Electrical fatigue tests have been conducted on PLZT ferroelectric ceramics. It was found that the higher the applied electrical field magnitude, the faster the Pr decreases; the samples under the same electrical field magnitude but with square wave have higher fatigue rate than that of sine wave. It was observed that at low frequency of applied field (50Hz and 500Hz), the polarization decreased very quickly and dropped below 70% of the original value within 106.2 switching cycles, however, when fatigue test were conducted at high frequencies of 100kHz and 300kHz, the polarization did not change significantly even after 109 cycles. The SEM analysis indicated that the facture mode was mainly of trans-granular for the virgin non-fatigued sample, while of inter-granular for the fatigue sample. The quantitative information on the 90° domain switching was measured in situ using X-ray diffraction. The effects of electrical characters on electrical fatigue behavior were explained according to the mechanism of electrical fatigue in PLZT ferroelectric ceramics.

To investigate the prevalence of and risk factors for non-alcoholic fatty liver disease (NAFLD) in a Chinese population.A total of 1948 adults from China was followed for 8 years. A cross-sectional study was performed to investigate the prevalence of NAFLD at baseline, and then the participants were followed for 8 years to investigate risk factors for the development of NAFLD.A total of 1948 participants were enrolled at baseline, of whom 691 were diagnosed with NAFLD. During the 8-year follow-up, 337 baseline NAFLD-free participants developed NAFLD. They had a greater increase in body mass index (BMI), serum uric acid, fasting plasma glucose, very low-density lipoprotein cholesterol and a considerable decrease in high-density lipoprotein cholesterol. 123 participants who had NAFLD at baseline lost NAFLD during the 8-year follow-up period. They had a greater decrease in BMI, fasting plasma glucose, triglycerides, total cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, and γ-glutamyl transpeptidase.NAFLD is prevalent in Chinese population with a rapidly increasing tendency. It can be reversed when patients lose their weight, control their hyperlipidemia and hyperglycemia, and reduce the liver enzyme levels.

Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of 3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA) content of the VSMC were assayed. Results: 1×10−9, 1×10−8, 1×10−7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%, and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P

The effect of Ho2O3 doping on the electrical properties and microstructure of ZnO base varistor was investigated. It was found that Ho2O3 is an effective dopant for increasing the breakdown electric filed. The Ho2O3 doping can also improve the nonlinear performance both in low and high current area. But excessive doping of Ho2O3 will decrease the withstanding surge current. With 0.8mol% Ho2O3 doping, the varistor samples exhibit a breakdown voltage of about 400V/mm, a nonlinear coefficient of 80 and the withstanding surge current of 8/20μs, waveshape is higher than 5kA. Ho2O3 dopant can hinder ZnO grain growth and make the crystal grains more uniform.

Arterioportal fistula (APF) is a rare cause of portal hypertension and may lead to death. APF can be congenital, post-traumatic, iatrogenic (transhepatic intervention or biopsy) or related to ruptured hepatic artery aneurysms. Congenital APF is a rare condition even in children. In this case report, we describe a 73-year-old woman diagnosed as APF by ultrasonography, computed tomography, and hepatic artery selective arteriography. The fistula was embolized twice but failed, and she still suffered from alimentary tract hemorrhage. Then, selective arteriography of the hepatic artery was performed again and venae coronaria ventriculi and short gastric vein were embolized. During the 2-year follow-up, the patient remained asymptomatic. We therefore argue that embolization of venae coronaria ventriculi and short gastric vein may be an effective treatment modality for intrahepatic APF with severe upper gastrointestinal bleeding.