the abilities of aspergillus niger and serpula himantioides to immobilize lead (pb) from lead sulphide (pbs) were investigated. upon growth on potato dextrose agar (pda) amended with pbs which contained 10mm pb, no visible solubilization activity was detected. a. niger produced biomass in greater quantity compared to s. himantiodes in both experimental and control media. with a ratio of 1.13, a...

This study discusses the technical rationale behind the development and validation of an alternative AAS and colorimetric methods for the determination of heavy metals in toothpastes containing tin as an active ingredient. Using BIS 6356:2001 method, it is found to be difficult to analyze toothpastes containing <100 ppm Pb, based on the PbS color formed by addition of sodium sulfide. In the pre...

Micron-sized liquid perfluorocarbon (PFC) droplets are currently being investigated as activatable agents for medical imaging and cancer therapy. After injection into the bloodstream, superheated PFC droplets can be vaporized to a gas phase for ultrasound imaging, or for cancer therapy via targeted drug delivery and vessel occlusion. Droplet vaporization has been previously demonstrated using a...

In many Dutch freshwater wetlands, concentrations of sulfate in the surface water and groundwater have increased. It is especially in peaty areas that this can lead to problems, including the reduction of sulfate to toxic sulfide. Our aquarium experiments showed that even low sulfide concentrations of 50 micromol/L are toxic to the freshwater macrophyte Nitella flexilis and the freshwater oligo...