CoNiSe with a vacancy-ordered spinel structure shows excellent bifunctional electrocatalytic activity for water splitting in alkaline medium producing 10 mA cm at a cell voltage of 1.61 V. For OER, an overpotential of 160 mV was needed for 10 mA cm which is one of the lowest overpotentials reported to date.

A CoNi2Se4–rGO nanocomposite fabricated on Ni foam shows excellent efficiency for non-enzymatic glucose sensing at low applied potential.

We are introducing graphene oxide modified with amine groups as a new solid phase for extraction of heavy metal ions including cadmium(II), copper(II), nickel(II), zinc(II), and lead(II). Effects of pH value, flow rates, type, concentration, and volume of the eluent, breakthrough volume, and the effect of potentially interfering ions were studied. Under optimized conditions, the extraction efficiency is >97 %, the limit of detections are 0.03, 0.05, 0.2, 0.1, and 1 μg L(-1) for the ions of cadmium, copper, nickel, zinc, and lead, respectively, and the adsorption capacities for these ions are 178, 142, 110, 125, and 210 mg g(-1). The amino-functionalized graphene oxide was characterized by thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectrometry. The proposed method was successfully applied in the analysis of environmental water and food samples. Good spiked recoveries over the range of 95.8-100.0 % were obtained. This work not only proposes a useful method for sample preconcentration but also reveals the great potential of modified graphene as an excellent sorbent material in analytical processes.

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Background: On December 2019, Novel coronavirus disease (COVID-19) was detected in Wuhan, China, and then spread around the world. There is little information about effects of COVID-19 on Pregnant women and newborns as a sensitive population. The current study is a systemic review and Meta-analysis to measure the risks and determine the presentations of COVID-19 in pregnant women and newborn.Methods: online data bases were searched on march 20. Heterogeneity of the included studies was assessed using the Cochran Q test and Higgins I 2 statistic and expressed as percentage. All data were analyzed with 95% confidence intervals.

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A hybrid supercapacitor comprising a NiCo2Se4-rGO composite has been fabricated on Ni foam and shows high energy and power density and superior flexibility.

Developing Nonenzymatic glucose biosensors has recently been at the center of attention owing to their potential application in implantable and continuous glucose monitoring systems. In this article, nickel telluride nanostructure with the generic formula of Ni 3 Te 2 has been reported as a highly efficient electrocatalyst for glucose oxidation, functional at a low operating potential. Ni 3 Te 2 nanostructures were prepared by two synthesis methods, direct electrodeposition on the electrode and hydrothermal method. The electrodeposited Ni 3 Te 2 exhibited a wide linear range of response corresponding to glucose oxidation exhibiting a high sensitivity of 41.615 mA cm –2 mM –1 and a low limit of detection (LOD) of 0.43 μM. The hydrothermally synthesized Ni 3 Te 2 , on the other hand, also exhibits an ultrahigh sensitivity of 35.213 mA cm –2 mM –1 and an LOD of 0.38 μM. The observation of high efficiency for glucose oxidation for both Ni 3 Te 2 electrodes irrespective of the synthesis method further confirms the enhanced intrinsic property of the material toward glucose oxidation. In addition to high sensitivity and low LOD, Ni 3 Te 2 electrocatalyst also has good selectivity and long-term stability in a 0.1 M KOH solution. Since it is operative at a low applied potential of 0.35 V vs Ag|AgCl, interference from other electrochemically active species is reduced, thus increasing the accuracy of this sensor.