Several methods have been developed for gold exploration in the past, among which biological base method is known to be the most efficient with least expenses. This method can also be used for latent gold prospects exploration. In the present study, the possibility of applying Bacillus cereus frequency in soil as a biological marker was investigated for the exploration of latent gold prospectin...

In this study, the biosynthesis of gold nanoparticles by Penicillium chrysogenum, isolated from Ahar copper mine, was investigated. The gold nanoparticles were synthesized by reducing the aqueous gold ions using the culture supernatant of the filamentous fungi. The UV–vis spectrum displayed a characteristic peak at 532 nm that is very specific for gold nanoparticles. The XRD spectrum confirmed ...

In recent years, the use of gold nanoparticles (GNPs) in radiation therapy has been studied by experimentation and Monte Carlo simulation repeatedly. Although the idea of increasing doses has been raised by high-atomic elements since decades ago, but due to the adaptation of gold nanoparticles with the biological system, scientists have incited more about the various uses of these materials in ...

This article lists a number of geological data on the conditions of formation of some major gold deposits in the conglomerates of the Earth's crust. We analyze the metallogenic, tectonic, stratigraphic and other factors controlling the formation of gold-bearing conglomerates in certain fields, such as the Witwatersrand (S. Africa) and Darwaz (Tajikistan). The following tectonic factors play the...

The discovery of complementary methods for enantioselective transition metal-catalyzed cyclization with silyloxyenynes has been accomplished using chiral phosphine ligands. Under palladium catalysis, 1,6-silyloxyenynes bearing a terminal alkyne led to the desired five-membered ring with high enantioselectivities (up to 91% ee). As for reactions under cationic gold catalysis, 1,6- and 1,5-silylo...

Fabrication of a cysteamine (CA) self-assembled monolayer (SAM) modified gold electrode insitu functionalized with L-Lysine (Lys) is presented and described. The fabricated electrode was used for highly selective and sensitive accumulation and the determination of copper ions (Cu) in a nanomolar concentration. Techniques like cyclic voltammetry (CV) and electrochemical impedance spectroscopy (E...

Aims. We study the enigmatic B[e] star MWC 300 to investigate its disk and binary with milli-arcsecond-scale angular resolution. Methods. We observed MWC 300 with the VLTI/AMBER instrument in the H and K bands and compared these observations with temperature-gradient models to derive model parameters. Results. The measured low visibility values, wavelength dependence of the visibilities, and wa...

In this paper, we present a technique to rapidly and directly examine ultramicroelectrodes (UMEs) by white light vertical scanning interferometry (VSI). This technique is especially useful in obtaining topographic information with nanometer resolution without destruction or modification of the UME and in recognizing tips where the metal is recessed below the insulating sheath. Two gold UMEs, on...

Electrochemical biosensors offer the promise of exceptional scalability and parallelizability. To achieve this promise, however, will require the development of new methods for the differential labeling of closely spaced electrodes with specific biomolecules such as DNA or proteins. Here we report a simple, highly selective method for passivating and differentially labeling closely separated go...