OBJECTIVE The aim was to examine the relation between environmental and biological (blood and urine) indices of exposure to different chemical forms of cobalt. METHODS A cross sectional study was undertaken in workers exposed to cobalt metal, oxides, and salts in a refinery and to a mixture of cobalt and tungsten carbide in a hard metal producing plant. RESULTS AND CONCLUSION Although biolo...

1-(2-Pyridylazo)-2-naphthol (PAN) has been used for the simultaneous and individual determination of palladium and cobalt at trace levels. PAN complexes of palladium and cobalt at neutral pH form green-color neutral complexes, which are soluble in aqueous SDS micellar media. Under optimum conditions, calibration graphs for individual determinations by zero and first-derivative spectrophotometry...

This paper reports on design, fabrication and characterization of high-Q MEMS resonators to be used in optical applications like laser displays and LIDAR range sensors. Stacked vertical comb drives for electrostatic actuation of single-axis scanners and biaxial MEMS mirrors were realized in a dual layer polysilicon SOI process. High Q-factors up to 145,000 have been achieved applying wafer leve...

Although the erythropoietic effect of cobalt has been amply demonstrated in experimental animals (1-3), in normal human beings (4, 5), and in certain types of anemia (4, 6-8), the mechanism of this increased blood formation has not been elucidated. No evidence has been adduced that administration of cobalt causes a decrease in oxygen capacity (9) or alters the oxygen dissociation curve (10, 11)...

Self-subunit swapping is one of the post-translational maturation of the cobalt-containing nitrile hydratase (Co-NHase) family of enzymes. All of these NHases possess a gene organization of <β-subunit> <α-subunit> , which allows the activator protein to easily form a mediatory complex with the α-subunit of the NHase after translation. Here, we discovered that the incorporatio...

PURPOSE To identify the molecular mechanism of steroid-induced downregulation of vascular endothelial growth factor (VEGF) synthesis in Müller cells. METHODS Confluent cultures of human Müller cells (MIO-M1) were treated with 100 microM CoCl(2), 1 microg/mL triamcinolone acetonide (TA), or both. VEGF secretion was measured with respect to time by ELISA. VEGF mRNA quantity and stability were a...

the synthesis of nano- structured cobalt through a controlled chemical process followed by heat treating at various temperatures is studied. the product is characterized by icp, xrd, fesem , and tem, indicating that the as- synthesized particles have an amorphous structure with 1.76 for co/b ratio, an average size of 50 nm. the transformation of intermediate phases into single phase nano- cryst...

The potential of carbon nanotubes (CNT) supported cobalt catalysts for Fischer-Tropsch (FT) reaction is shown. Using the wet impregnation method cobalt on carbon nanotubes catalysts were prepared with cobalt loading varying from 15 to 45 wt. %. The catalysts are characterized by different methods including: BET physisorption, X-ray diffraction, hydrogen chemisorption, and temperature-progra...

background: one of the methods used for joining metals together is welding, which can be carried out using different techniques such as electric spot welding. this study evaluated the effect of electric spot welding on the load defl ection rate of stainless steel and chromium-cobalt orthodontic wires. materials and methods: in this experimental-laboratory study, load defl ection rate of 0.016 ×...

The transformation of enynes under cobalt-catalysis leads to symmetrical benzannulation products in dichloromethane. In tetrahydrofuran the cobalt-catalysed reactions afforded the unprecedented unsymmetrical benzannulation products in moderate to good yields and good regioselectivities. In addition, cyclotrimerisation of the alkyne subunit can be realised when electron-deficient enynes are appl...