Mapping protein expression in mouse pancreatic islets by immunolabeling and electron energy loss spectrum-imaging

A combination of immuno-electron microscopy and electron energy-loss spectrum-imaging was used to map the distributions of endocrine polypeptide hormones and proteins in mouse pancreatic islet of Langerhans. Tissue was analyzed from control animals and from mice that were heterozygous for the Anx7 gene, which defines a Ca2+/GTP-dependent membrane fusion and ion channel protein. The heterozygous Anx7 (+/-) mouse displays defects in IP3 receptor mediated Ca2+ signaling and insulin secretion. Therefore, information was obtained about the distributions of the hormones insulin and glucagon, as well as the proteins ANX7 and the IP3 receptor. Insulin secretion appears to be defective in the mutants. It was found from immunolabeling experiments that expression of the IP3 receptor is reduced in mutant islets compared to control islets. Subcellular distributions of sulfur and nitrogen obtained by electron energy-loss spectrum-imaging showed that the insulin concentrations of beta granules were essentially the same in control and mutant islets. By contrast, immunogold labeling of mutant islets shows more insulin immunoreactivity in the beta granules. It follows that insulin may be packaged differently in mutant islets, making antigenic determinants more available to the labeling antibody. The increased rate of insulin secretion in the hyperplastic mutant islets can be explained by compensatory increases in islet size, rather than by an increased insulin concentration in the beta cells. The results indicate that reduced ANX7 expression leads to defects in the IP3 receptor expression in the endocrine cells of the mutant mouse. Increased size of the islet or of adrenal medulla may be a compensatory mechanism for secretion defect by individual endocrine cells. Defects in IP3 receptor expression, and documented consequences of a Ca2+ signaling defect, lead to other changes in organelles such as the mitochondrial number in islet beta-cells. The effects and consequences of reduced ANX7 expression on mitochondria are evident in ultrastructural observations.     

Electron Donating Property and Catalytic Activity ofPerovskite-type Mixed Oxides (ABO_3) Consisting of Rare Earth and 3d Transition Metals

The catalytic activity of Perovskite-type mixed oxides (LaCoO3, PrCoO3 and SmCoO3) for the reduction of cyclohexanone to cyclohexanol with 2-propanol (Meerwein-PonndorfVerley reduction) has been studied. The data have been correlated with the surface electron donor properties of these mixed oxides     

Contrast Enhancement of Retinal Images Using Green Plan Masking and Whale Optimization Algorithm

Wireless Personal Communications - In this study, a coplanar waveguide fed patch antenna is proposed for Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access...     

Sub‐Micrometer Zeolite Films on Gold‐Coated Silicon Wafers with Single‐Crystal‐Like Dielectric Constant and Elastic Modulus

A low‐temperature synthesis coupled with mild activation produces zeolite films exhibiting low dielectric constant (low‐k) matching the theoretically predicted and experimentally measured values for single crystals. This synthesis and activation method allows for the fabrication of a device consisting of a b‐oriented film of the pure‐silica zeolite MFI (silicalite‐1) supported on a gold‐coated silicon wafer. The zeolite seeds are assembled by a manual assembly process and subjected to optimized secondary growth conditions that do not cause corrosion of the gold underlayer, while strongly promoting in‐plane growth. The traditional calcination process is replaced with a nonthermal photochemical activation to ensure preservation of an intact gold layer. The dielectric constant (k), obtained through measurement of electrical capacitance in a metal–insulator–metal configuration, highlights the ultralow k ≈ 1.7 of the synthetized films, which is among the lowest values reported for an MFI film. There is large improvement in elastic modulus of the film (E ≈ 54 GPa) over previous reports, potentially allowing for integration into silicon wafer processing technology.     

Structured approach in PLC (programmable logic controller) programming for water/wastewater applications

This paper describes a methodology for efficient implementation of PLC programming for water/wastewater applications. The PLC was interfaced with a supervisory host computer which used touch screen equipped color monitors as operator interfaces. PLC ladder logic had to be designed to process real-world hardwired I/O as well as the I/O received from the host computer and/or touch screens, via a communications link. Standard "templates" of PLC networks were developed for (a) pump controls including provision for touch screen I/O; (b) PID control; (c) alarms; (d) motor run times; (e) square root extraction; (f) signal conversion, and (g) flow totalization. All logic was implemented using the standard templates. This structured approach led to efficient implementation, easy debugging/start-up, and easy to read uniform ladder logic.     

Deconvolution of damping forces with a nonlinear microresonator

We report a fully electrical microcantilever device that utilizes capacitance for both actuation and detection and show that it can characterize various gases with a bare silicon microcantilever. We find the motion of the cantilever as it rings down when the oscillating force is removed, by measuring the voltage induced by the oscillating capacitance in the microcantilever∕counterelectrode system. The ringdown waveform was analyzed using an iterative numerical algorithm to calculate the oscillator motion, modeling the cantilever∕electrode capacitance to calculate the electrostatic force. We find that nonlinearity in the motion of the cantilever is not necessarily a disadvantage. After calibration, we simultaneously measure viscosity and density of several gaseous mixtures, yielding viscosities within ±2% and densities within ±6% of NIST values.     

Synthesis and characterization of thallium-thorium molybdates and thallium-uranium (IV) molybdates

In quaternary Tl-Th-Mo-O and Tl-U(IV)-Mo-O systems, Tl₂Th(MoO₄)₃, Tl₄Th(MoO₄)₄, Tl₂U(MoO₄)₃ and Tl₄U(MoO₄)₄ were synthesized by reacting Tl₂MoO₄ with molybdates of thorium and uranium in stoichiometric molar proportions at 773 K. Thallium U(IV) molybdates were prepared in evacuated sealed quartz ampoules. These compounds were characterized by X-ray, thermal and infrared techniques. Powder X-ray diffraction data of all four compounds were indexed on orthorhombic system. When heated in thermoanalyzer in He atmosphere, Tl₂U(MoO₄)₃ and Tl₄U(MoO₄)₄ showed melting at 792 K and 853 K, respectively, whereas heating of both the compounds in air oxidized them to Tl₂UO₂(MoO₄)₂. Both Tl₂Th(MoO₄)₃ and Tl₄Th(MoO₄)₄, when heated in air, showed a reversible phase transition followed by melting of the compounds. Isothermal heating of all thallium-thorium and thallium-uranium molybdates at 1573 K led to the formation of ThO₂ and U₃O₈, respectively, as end products.     

Structural,dielectric and ferroelectric properties of Ba1−x(Bi0.5Na0.5)xTiO3 ceramics

Lead free Ba_1?x(Bi_0.5Na_0.5)_xTiO₃ (x=0, 0.02, 0.04, 0.06, 0.08, 0.1) ferroelectric ceramics were synthesized by conventional solid state reaction technique. Sintering was done at 1200 °C for 2 h in air atmosphere. The final products have tetragonal symmetry with decreasing c/a ratio confirmed by X-ray diffraction analysis. The grain size varies between 300 nm to 1000 nm for x=0 to 0.1. With increase in Bi_0.5Na_0.5TiO₃ [BNT] content, the room temperature permittivity decreases whereas the Curie temperature (T_c) increases and its highest value was found to be 155 °C for 10 mol% of BNT addition. The ceramics show stable and low dielectric loss characteristics. The remnant polarization (P_r) and the coercive field (E_c) increases monotonously with increase in BNT content. The highest value of 2P_r (=17 μC/cm²) and 2E_c (=22 Kv/cm) was obtained for x=10 mol% BNT addition.     

Mechanical, thermal and transport properties of nitrile rubber (NBR)—nanoclay composites

The article describes the properties of nitrile rubber (NBR)??nanoclay composites prepared by a two-step method. viz. preparation of a 3:1 [by weight] masterbatch of NBR and nanoclay followed by compounding on a two roll mill and molding at 150?°C and 20?MPa pressure. The tensile strength, elongation at break, modulus, storage modulus (E??) and loss modulus (E??) increased with the nanofiller content, reached the maximum value at 5 phr and decreased thereafter. The solvent uptake, diffusion, sorption and permeation constants decreased with nanoclay content with the minimum value at 5 phr nanoclay. The mechanism of solvent diffusion through the nanocomposites was found to be Fickian. Thermodynamic constants such as enthalpy and activation energy were also evaluated. The dependence of various properties on nanoclay content was correlated to the morphology of the nanocomposites. supported by morphological analysis.     

EPDM–chlorobutyl rubber blends in γ‐radiation and hydrocarbon environment: Mechanical,transport, and ageing behavior

In nuclear applications, ethylene propylene diene monomer (EPDM) rubber is the material of choice as gaskets and O‐rings due to its radiations resistance. In nuclear fuel reprocessing, in addition to radiation, the elastomeric components have to withstand paraffinic hydrocarbons as well. But, EPDM has poor resistance to hydrocarbons. To enhance the durability of EPDM in such environments, EPDM–chlorobutyl rubber (CIIR) blends of varying compositions were developed and characterized for mechanical, thermal, dielectric, and solvent sorption behavior. Spectroscopic and morphological analysis was used to evaluate the compatibility of blends. Due to synergistic effect, the optimal composition of blends with superior mechanical properties and solvent resistance were found to be 60% to 80% EPDM and 20% to 40% CIIR. The optimized blends were irradiated with gamma rays at cumulative doses up to 2 MGy. Based on spectroscopic, morphological, mechanical, thermogravimetric, and sorption properties, blend containing 80% EPDM was found to have superior retention of properties after irradiation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45195.