We describe a sensitive method for the determination of vanadium in biological substances by atomic absorption spectroscopy. By using background correction and pyrolytically coated graphite tubes with flameless apparatus, this vanadium assay has a sensitivity of 65 pg and a detection limit of 30 pg, approximately sixfold more sensitive than previously reported assays involving this technique. T...

A simple and versatile method for preparation of new crystalline graphite nitrate-like ammonium vanadium bronze (NH4)0.19V2O5·0.44H2O nano-microstructures is developed via a simple hydrothermal route following heat treatment. (NH4)0.19V2O5·0.44H2O platelets are tested as a novel high-energy cathode material for sodium-ion batteries. The enhancement of electrochemical performance for a (NH4)0.19...

Active heat flow control is essential for broad applications of heating, cooling, and energy conversion. Like electronic devices developed for the control of electric power, it is very desirable to develop advanced all-thermal solid-state devices that actively control heat flow without consuming other forms of energy. Here we demonstrate temperature-gated thermal rectification using vanadium di...

Vanadium belongs to the group of transition metals and is present in the air and soil contaminants in large urban agglomerations due to combustion of fossil fuels. It forms numerous inorganic compounds (vanadyl sulfate, sodium metavanadate, sodium orthovanadate, vanadium pentoxide) as well as complexes with organic compounds (BMOV, BEOV, METVAN). Depending on the research model, vanadium compou...

Some ascidians (sea squirts) accumulate the transitional metal vanadium in their blood cells at concentrations of up to 350 mM, about 10(7) times its concentration found in seawater. There are approximately 10 different types of blood cell in ascidians. The identity of the true vanadium-containing blood cell (vanadocyte) is controversial and little is known about the subcellular distribution of...

Vanadyl sulfate and sodium orthovanadate in the concentration range between 5 and 50 microM are shown to be mitogenic for quiescent cultures of Swiss mouse 3T3 and 3T6 cells. The compounds caused a striking shift in the dose-response for the effect of serum on [3H]thymidine incorporation and DNA synthesis. In the absence of serum the effect of vanadium was greatly potentiated by insulin. Vanadi...

Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting pr...

Very few nitrosyl derivatives of the first transition elements are known [1, 2], [^-C5HsCr(NO)2]2 has been obtained by reduction of ^-CsHsCrNOCl with sodium borohydride [3]. The only known cyclopentadienylnitrosyl vanadium complexes are T?-C5H5V(NO)2CO [4] and the cation [>?-C5H5V(NO)3]+ [5]. The most important methods used to obtain these complexes consist of treatment of carbonyl complexes wi...

We examined the effects of vanadium sulfate (VOSO4) treatment at 5 and 10 mg/kg for 30 days on endocrine pancreas activity and histology in nondiabetic and STZ-induced diabetic rats. In diabetic group, blood glucose levels significantly increased while insulinemia level markedly decreased. At the end of treatment, VOSO4 at a dose of 10 mg/Kg normalized blood glucose level in diabetic group, res...

The influence of various preparation methods on the performance of V-Nb-0 catalysts has been investigated. It was found that the activity and selectivity of a vanadium site depend on the nature of the neighbouring atoms. Vanadium neighbours provide activity, while niobium neighbours provide selectivity. Careful preparation of these catalysts ensures a homogeneous distribution and good mixing of...