Preparation and field-induced electrical properties of perovskite relaxor ferroelectrics

(111)-oriented and random oriented Pb0.8Ba0.2ZrO3 (PBZ) perovskite relaxor ferroelectric thin films were fabricated on Pt(111)/TiOx/SiO2/Si substrate by sol-gel method. Nano-scaled antiferroelectric and ferroelectric two-phase coexisted in both (111)-oriented and random oriented PBZ thin film. High dielectric tunability (i = 75%, E = 560 kV/ cm ) and figure-of-merit (FOM ~ 236) at room temperature was obtained in (111)-oriented thin film. Meanwhile, giant electrocaloric effect (ECE) (AT = 45.3 K and AS = 46.9 JK-1kg-1 at 598 kVcm-1) at room temperature (290 K), rather than at its Curie temperature (408 K), was observed in random oriented Pb0.8Ba0.2ZrO3 (PBZ) thin film, which makes it a promising material for the application to cooling systems near room temperature. The giant ECE as well as high dielectric tunability are attributed to the coexistence of AFE and FE phases and field-induced nano-scaled AFE to FE phase transition

Self-Assembled Monolayer of Mixed Gold and Nickel Nanoparticles

Forming a monolayer of mixed nickel and gold nanoparticles through self-assembly via simple solution processing constitutes an important step toward inexpensive nanoparticle-based carbon nanofiber growth. In this work, mixed gold and nickel nanoparticles were anchored on the silicon wafer using self-assembled monolayers (SAMs) as a template. SAMs of 3-mercaptopropyl trimethoxysilane (MPTS-SAMs) were formed on silicon wafer, with the exposed thiol functionality providing ligand exchange sites to form the mixed monolayer of nickel and gold nanoparticles via a two-step sequential soaking approach. The densities of the nickel and gold nanoparticles on the surface can be varied by adjusting the soaking sequence

High tunability in (111)-oriented relaxor Pb0.8Ba0.2ZrO3 thin film with antiferroelectric and ferroelectric two-phase coexistence

Using a sol-gel method Pb0.8Ba0.2ZrO3 (PBZ) thin film with a thickness of ~320 nm was fabricated on Pt(111)/TiOx/SiO2/Si substrate. The analysis results of XRD, SEM, and dielectric properties revealed that this thin film is a (111)-oriented nano-scaled antiferroelectric and ferroelectric two-phase coexisted relaxor. Calculations of dielectric tunability (η) and figure-of-merit (FOM) at room temperature display a maximum value of 75% at E = 560 kV/cm and ~236, respectively. High-temperature stability (η > 75% and FOM > 230 at 560 kV/cm in the range from 300 to 380 K) and high breakdown dielectric strength (leakage current < 1 nA at 598 kV/cm) make the PBZ thin film to be an attractive material for applications of tunable devices

MECHANICAL CHARACTERISTICS OF NANO-CRYSTALLINE MATERIAL IN METALLIC GLASS FORMERS

In order to evaluate the model metallic glass alloy’s mechanical properties (Fe49.7 Cr17.1 Mn1.9 Mo7.4 W1.6 B15.2 C3.8 Si2.4) prepared by spark plasma sintering (SPS) which have high velocity.  We made an apparatus having three-point curve testing. The comparatively bulk sizes of sample in the current study permitted the creation samples for test with a macro scale cross-section (range of mm) consistent test dimensions, and well-controlled sample sizes. Cutting using a wire saw produced remarkably sharp notches with a radius that was 3 times smaller than in earlier studies. Our three-point bending apparatus allowed us to acquire the 231 GPa and 4.91 MPam1/2 values for notch fracture toughness and young's modulus. Additionally, the results of the Vickers indentation and flexure tests for young's modulus were reliable. Vickers indentation measurements of indentation fracture toughness produced values that were a minimum of 49.9% lower than those obtained flexure using. The method for examine micro scale mechanical properties described in this study and the accompanying scrutinizes are valid to samples with different ones or compositions that are made by further means

Giant electric energy density in epitaxial lead-free thin films with coexistence of ferroelectrics and antiferroelectrics

Ferroelectrics/antiferroelectrics with high dielectric breakdown strength have the potential to store a great amount of electrical energy, attractive for many modern applications in electronic devices and systems. Here we demonstrate that a giant electric energy density (154 J×cm-3, 3 times the highest value of lead-based systems and 5 times the value of the best dielectric/ferroelectric polymer), together with the excellent fatigue-free property, good thermal stability and high efficiency, is realized in pulsed laser deposited (Bi1/2Na1/2)0.9118La0.02Ba0.0582(Ti0.97Zr0.03)O3 (BNLBTZ) epitaxial lead-free relaxor thin films with the coexistence of ferroelectric (FE) and antiferroelectric (AFE) phases. This is endowed by high epitaxial quality, great relaxor dispersion and the coexistence of the FE/AFE phases near the morphotropic phase boundary (MPB). The giant energy storage effect of the BNLBTZ lead-free relaxor thin films may make a great impact on the modern energy storage technology

Metabolic Disturbance and Th17/Treg Imbalance Are Associated With Progression of Gingivitis

ObjectiveThis study sought to explore the role of metabolic disturbance in immunoregulation of gingivitis targeting T helper 17 cells (Th17)/regulatory T cell (Treg).Materials and MethodsA total of 20 gingivitis patients and 19 healthy volunteers were recruited. Quantitative real time polymerase chain reaction (qRT-PCR) was used to evaluate expression patterns of Forkhead box protein P3 (Foxp3), transforming growth factor-β (TGF-β), retinoid-related orphan receptor-gammat (RORγt) and interleukin 17A (IL-17A) in the peripheral blood lymphocytes of subjects across the two groups. Moreover, the enzyme-linked immunosorbent assay (ELISA) technique was used to detect levels of TGF-β, IL-4, IL-6,TL-10 and L-17A secreted in the plasma as well as the SIgA secreted in saliva. Flow cytometry was used to detect the percentage of CD4+CD25+ Foxp3+Treg cells and the percentage of CD4+IL-17A+ Th17 cells in whole blood of subjects in both groups. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the plasma metabolites in the gingivitis patient group. Statistical analysis was applied to determine whether the plasma metabolites and related metabolic pathways significantly differed between gingivitis patients and healthy controls. Ingenuity pathway analysis (IPA) was employed to identify the potential relation between the metabolites and the Th17 and Treg related pathway.ResultsThe percentages of CD4+IL17A+Th17 cells and IL-17 significantly increased in the peripheral blood in the gingivitis group. Moreover, the upregulation of IL-17A mRNA and RORγt mRNA were also found in the gingivitis group. However, the percentage of CD4+CD25+ Foxp3+Treg cells and Foxp3 mRNA in the whole blood did not significantly change. However, TGF-β mRNA as well as TGF-β, IL-4, IL-6, IL-10 in the periperial blood and SIgA in the saliva were higher in the gingivitis group. Notably, that the ratio of Th17/Treg cells was significantly increased during peripheral circulation. Furthermore, we identified 18 different metabolites which were differentially expressed in plasma between the gingivitis and healthy control groups. Notably, the levels of cholesterol, glycerol 1-octadecanoate, d-glucose, uric acid, cyclohexaneacetic acid, 3-pyridine, tryptophan, and undecane 2,4-dimethyl were significantly up-regulated. whereas the levels of lactic acid, glycine, linoleic acid, monopalmitic acid, glycerol, palmitic acid, pyruvate, 1-(3-methylbutyl)-2,3,4,6-tetramethylbenzene, 1 5-anhydro d-altrol, and boric acid were down-regulated in the gingivitis group, relative to healthy controls. IPA showed that these metabolites are connected to IL17 signaling, TGF-B signaling, and IL10 signaling, which are related closely to Th17 and Treg pathway.ConclusionOverall, these results showed that disturbance to glycolysis as well as amino and fatty acid metabolism are associated with Th17/Treg balance in gingivitis. Impaired immunometabolism may influence some periodontally involved systemic diseases, hence it is a promising strategy in targeted development of treatment therapies

A 4-Transistor Monolithic Solution to Highly Linear On-Chip Temperature Sensing in GaN Power Integrated Circuits

We report the monolithic realization of on-chip temperature sensing design using four transistors (4T) in gallium nitride (GaN) technology. The temperature sensor consists of a voltage reference and a logic inverter, both of which are built from enhancement-mode (E-mode) and depletion-mode (D-mode) metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs). The temperature-insensitive voltage reference outputs a very stable voltage as the input of the logic inverter, which exhibits good temperature dependence in its voltage transfer characteristics. As the temperature varies from 25 to 250 °C, the output voltage of the logic inverter changes linearly. By configuring the active-load D-mode transistor as a two-dimensional electron gas (2DEG) resistor in the logic inverter, the temperature sensing solution is improved further, showing stable sensing output, higher sensitivity (31.28 mV/°C), better linearity ( R2 = 0.995) and smaller error (±2.74 °C). This demonstrates a compact monolithic sensor for monitoring the on-chip temperature of GaN power integrated circuits (ICs) for protection and control