Sensitive Quantification of Fe(III) in Food Samples at Screen Printed Carbon Electrode Modified with Graphene and Piroxicam by Catalytic Adsorptive Voltammetry

A new disposable sensitive voltammetric sensor for the determination of Fe(III) based on a graphene (G) and piroxicam (Pir) modified screen printed carbon electrode (Pir/G/SPCE) has been developed. The developed method is based on accumulation of Fe(III) on the surface of the prepared sensor strip, formation a complex with Pir and subsequent reduction the adsorbed chelated Fe(III) at ?0.03 V (vs. Ag/AgCl) coupled with the catalytic enhancement of bromate. Characterizations of the modified electrode surface were performed by field emission scanning electron microscopy (FE‐SEM), energy dispersive X‐ray spectroscopy (EDX) and electrochemical impedance spectroscopy (EIS). Electrochemical behavior of the modified SPCEs was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimum conditions, the catalytic voltammetric method exhibited linear calibration plot in the concentration ranges of 1–100 ng mL^?1 and 100–3500 ng mL^?1 Fe(III) with a limit of detection of 0.3 ng mL^?1. The sensor strip displayed good reproducibility with 1.7 % relative standard deviation (RSD%). The developed method was successfully applied for the determination of iron in food samples such as vegetables, fruit, and cereal.     

Dendritic analogues of engineering plastics - a general one-step synthesis of dendritic polyaryl ethers

The first general single-step route to dendritic or cascade polyaryl ethers analogous to common linear polyaryl ethers is described. The sodium salts of four AB₂ monomers each containing a single phenolic hydroxyl group and two aryl fluorides activated toward nucleophilic substitution by carbonyl, sulphonyl, or tetrafluorophenyl moieties are shown to polymerize in hot N, N-dimethylacetamide. The products are high molecular weight polymers (7000 < M_n < 36000), have narrow polydispersities (1.50 < M_w/M_n < 4.50), and are highly soluble in organic solvents. The molecular weights of two of the polymers increase with monomer concentration. The polymers are thermally stable (500 °C under N₂) and have glass transition temperatures ranging from 135 to 231 °C.     

Effects of Roxadustat on Erythropoietin Production in the Rat Body

Anemia is a major complication of chronic renal failure. To treat this anemia, prolylhydroxylase domain enzyme (PHD) inhibitors as well as erythropoiesis-stimulating agents (ESAs) have been used. Although PHD inhibitors rapidly stimulate erythropoietin (Epo) production, the precise sites of Epo production following the administration of these drugs have not been identified. We developed a novel method for the detection of the Epo protein that employs deglycosylation-coupled Western blotting. With protein deglycosylation, tissue Epo contents can be quantified over an extremely wide range. Using this method, we examined the effects of the PHD inhibitor, Roxadustat (ROX), and severe hypoxia on Epo production in various tissues in rats. We observed that ROX increased Epo mRNA expression in both the kidneys and liver. However, Epo protein was detected in the kidneys but not in the liver. Epo protein was also detected in the salivary glands, spleen, epididymis and ovaries. However, both PHD inhibitors (ROX) and severe hypoxia increased the Epo protein abundance only in the kidneys. These data show that, while Epo is produced in many tissues, PHD inhibitors as well as severe hypoxia regulate Epo production only in the kidneys.     

Comparative Hydrodynamic Study on Non-Aqueous Soluble Archaeological Wood Consolidants: Butvar B-98 and PDMS-OH Siloxanes

Butvar B-98 and PDMS-OH both have a demonstrable ability as consolidants for archaeological wood. This makes them both potential treatment options for the Oseberg collection, which is one of the most important archaeological finds from the Viking era. Both Butvar B-98 and PDMS-OH are soluble in organic solvents, offering a useful alternative to aqueous-based consolidants. Extensive characterisation studies were carried out on both of these polymers, with the use of analytical ultracentrifugation and viscometry, for the benefit of conservators wanting to know more about the physical properties of these materials. Short column sedimentation equilibrium analysis using SEDFIT-MSTAR revealed a weight-average molar mass (weight-average molecular weight) M_w of (54.0 ± 1.5) kDa (kg · mol⁻¹) for Butvar B-98, while four samples of PDMS-OH siloxanes (each with a different molar mass) had an M_w of (52.5 ± 3.0) kDa, (38.8 ± 1.5) kDa, (6.2 ± 0.7) kDa and (1.6 ± 0.1) kDa. Sedimentation velocity confirmed that all polymers were heterogeneous, with a wide range of molar masses. All molecular species showed considerable conformational asymmetry from measurements of intrinsic viscosity, which would facilitate networking interactions as consolidants. It is anticipated that the accumulated data on these two consolidants will enable conservators to make a more informed decision when it comes to choosing which treatment to administer to archaeological artefacts.     

Mammalian-like Purple Acid Phosphatases in Plants

Introduction Purpleacidphosphatases(PAPs)compriseofa familyofbinuclearmetal containinghydrolases,some membersofwhichhavebeenisolatedandcharacterized fromanimal,plantandfungalsources[1].PAPsnoton lycatalyzethehydrolysesofawiderangeofphosphate estersandanhy…     

Alternate method of source preparation for alpha spectrometry: no electrodeposition,no hydrofluoric acid

Journal of Radioanalytical and Nuclear Chemistry - An alternate method of preparing actinide alpha counting sources was developed in place of electrodeposition or lanthanide fluoride...