Effect of heat treatment on the migration behaviour of Sr and Ag CO-implanted in glassy carbon

The effect of annealing on the diffusion of silver, silver and strontium co-implanted in glassy carbon was investigated. Glassy carbon samples were implanted with 360 keV Ag ions at room temperature. The RBS profile showed that Fickian diffusion of Ag in glassy carbon is only observed at temperatures ranging from 500 °C–600 °C. At higher annealing temperatures, there was a significant loss of Ag and no Ag was retained in glassy carbon at 700 °C. Glassy carbon samples were also co-implanted with Ag and Sr. The diffusion behaviour of Ag when co-implanted with Sr was similar to that of the singly implanted Ag sample. However, the introduction of Sr into the glassy carbon matrix assisted in the retainment of the Ag ions. The co-implantation of Ag and Sr resulted in a change in the diffusion behaviour of Sr in glassy carbon. The implantation of Ag with Sr prevented the movement of Sr deeper into the bulk of the glassy carbon. The non-movement of Sr into the bulk of the glassy carbon was attributed to the increase of radiation damage near the surface of the glassy carbon making diffusion of Sr towards the surface of glassy carbon an easier choice.The National Research Foundation, South Africa and the TWAS-DFG Co-operation Programme.http://www.journals.elsevier.com/vacuumhj2021Physic

Synthesis and gastroprotective activities of some zinc (II) complexes derived from (E)-2-(1-(2-(piperazin-1-yl)ethylimino)ethyl)phenol and (E)-4-(1-(2-(piperazin-1-yl)ethylimino)ethyl)benzene-1,3-diol Schiff bases against aspirin induced ulceration

This study describes the protective effects of piperazine derived compounds against aspirin induced gastric injuries and evaluated the role of nitric oxide, inflammatory cytokines and serum level of aspartate aminotransaminases (AST), alanine aminotransaminases (ALT), high density lipoprotein (HDL) and malondialdehyde (MDA). The oral administration of the compounds at doses 30 and 60 mg/kg protected the gastric against the nectrotizing effects of aspirin. The level of nitric oxide (NO) was elevated in the group pretreated with the compounds. The results also showed that pre-treatment with piperazine compounds has led to the decrease in the amount of MDA and increased the activity of AST, ALT and HDL. In conclusion, pre-treatment with piperazine derived compounds; (E)-2-(1-(2-(piperazin-1-yl)ethylimino)ethyl)phenol (2HP), (E)-4-(1-(2-(piperazin-1-yl)ethylimino)ethyl) benzene-1,3-diol (DHP) and their zinc complexes has provided a significant protection to the gastric from damaging effects of aspirin

Photoluminescence and phase related cathodoluminescence dynamics of Pr3+ doped in a double phase of ZnTa2O6 and ZnAl2O4

A new phosphor ZnTaAlO5:Pr3+, which displays cathodoluminescence intensity that is phase dependent, was synthesised by solid statereaction. x-ray diffraction, scanning electron microscopy and EDX (energy dispersive x-ray spectroscopy) maps were used to confirm the multi-phase, multi-particle shapes and to assign each particle shape o a corresponding phase of the phosphor, respectively. Cathodoluminescence mapswere obtained simultaneously with the EDX maps, and showed both the luminescence emerging from intrinsic and extrinsic defect centres. Theactivator red emission was better resolved using photoluminescence spectroscopy, which showed emission lines emerging from more than onemanifold of the Pr3+transitions. The persistent luminescence was measured and the corresponding electron trapping centres were characterisedby thermoluminescence spectroscopy.This work is based on financial contribution from the South African Research Chairs Initiative of the Department of Science and Technology (84415), National Research Foundation of South Africa and the Erasmus Mundus–Saturn action 2 programme funded by the European Union (2014/2015).A new phosphor ZnTaAlO5:Pr3+, which displays cathodoluminescence intensity that is phase dependent, was synthesised by solid statereaction. x-ray diffraction, scanning electron microscopy and EDX (energy dispersive x-ray spectroscopy) maps were used to confirm the multi-phase, multi-particle shapes and to assign each particle shape o a corresponding phase of the phosphor, respectively. Cathodoluminescence mapswere obtained simultaneously with the EDX maps, and showed both the luminescence emerging from intrinsic and extrinsic defect centres. Theactivator red emission was better resolved using photoluminescence spectroscopy, which showed emission lines emerging from more than onemanifold of the Pr3+transitions. The persistent luminescence was measured and the corresponding electron trapping centres were characterisedby thermoluminescence spectroscopy

Passivity compensation algorithm for method-of-characteristics-based multiconductor transmission line interconnect macromodels

Computation of passive and compact macromodels of distributed interconnects has gained considerable importance during the recent years. Method of characteristics (MoC) is widely used for macromodeling of transmission lines, however, it may not be guaranteed passive. This paper presents a new algorithm for passivity enforcement of MoC-based macromodels of multiconductor transmission lines. The algorithm is based on the first-order perturbation of the related delay differential equations and can handl

A robust algorithm for passive reduced-order macromodeling of MTLs with FD-PUL parameters using integrated congruence transform

This paper presents a robust method for guaranteed passive macromodeling of high-speed interconnects characterized by multi-conductor transmission lines with frequency-dependent per-unit-length (FD-PUL) parameters, using integrated-congruence-transformationbased model-order-reduction techniques. For this purpose, a new formulation is developed to directly incorporate state-space equations corresponding to the positive-real (PR) rational functions representing the frequency dependence of PUL parameters, in Telegrapher's equations. The proposed formulation overcomes the need for explicit lumped-circuit realization with all positive elements for PR rational functions of FD-PUL parameters. Proof of passivity and numerical examples

Single-fiber-based probe for combined imaging and pH sensing

A single-fiber-based probe with a diameter of 125 μm, capable of combined imaging and sensing, was developed and applied in an in vitro fertilization setting. The probe can resolve a cumulus oocyte complex within an ovarian follicle, and measure a pH change of 0.04 units.Jiawen Li, Patrick K. Capon, Aimee J. Horsfall, Suliman Yagoub, Erik P. Schartner, Asma Khalid, Rodney W. Kirk, Malcolm S. Purdey, Kylie R. Dunning, Robert A. McLaughlin, Andrew D. Abel

A silk‐based functionalization architecture for single fiber imaging and sensing

First published: 29 March 2021A new fiber functionalization architecture for single-fiber imaging and sensing is presented. 5(6)Carboxy-seminaphthorhodafluor-2 (a fluorescent pH sensor) is attached to a silk-binding peptide and the complex added to aqueous silk fibroin protein. These bind with a Kd of 36 µM as determined by a fluorescence polarization assay. The fiber is dip-coated into the silk and peptide mixture, and scanning electron microscopy images reveal a uniform silk coating on the fiber tip. The coating is stable to repeated washes and does not affect the imaging light emitted from the fiber, which allows concurrent optical coherence tomography (OCT) imaging and pH sensing. Oocytes are metabolically stimulated with CoCl2 to produce lactic acid, and a pH reduction of 0.04 is measured using the probe. The distance between fiber tip and oocyte is monitored by simultaneous OCT acquisitions to precisely position the probe. Lastly, OCT imaging of an ovary revealed the presence/absence of an oocyte within a follicle, an important step toward improving patient outcomes during in vitro fertilization, by limiting the number of invasive follicle punctures required. These results demonstrate the utility of this new coating to enable simultaneous OCT imaging and sensing, which provides significant insight into complex biological systems.Patrick K. Capon, Jiawen Li, Aimee J. Horsfall, Suliman Yagoub, Erik P. Schartner, Asma Khalid, Rodney W. Kirk, Malcolm S. Purdey, Kylie R. Dunning, Robert A. McLaughlin, and Andrew D. Abe