The oxidation of either ferrous iron or sulfur by Thiobacillus ferrooxidans was selectively inhibited or controlled by various anions, inhibitors, and osmotic pressure. Iron oxidation was more sensitive than sulfur oxidation to inhibition by chloride, phosphate, and nitrate at low concentrations (below 0.1 M) and also to inhibition by azide and cyanide. Sulfur oxidation was more sensitive than ...

Burkholderia cepacia CC-Al74 with a high ability for solubilizing tricalcium phosphate (TCP) was used to study the P-solubilization mechanism. We collected filtrates able to solubilize TCP from the cultures of strain CC-Al74 and demonstrated that the P-solubilization increased from 0 microg ml(-1) to 200 microg ml(-1) during exponential growth, when the pH decreased from 8 to 3. HPLC-analysis r...

It is a well-known fact that sirolimus (SRL) undergoes degradation process via hydrolysis in aqueous media, leading to incorrect assessment of drug amount and thus release characteristics of formulations. The main objective of the present study was to evaluate the effect of nonionic surfactants in media on in-vitro release profiles for sirolimus eluting stents (SES) coated with biodegradable po...

Optimal conditions for the isolation of nuclear envelopes by the action of heparin on nuclei are established and a morphological and biochemical study of such isolated envelopes is presented. An almost 100% yield of pure nuclear envelopes can be obtained by a single sedimentation step after incubation of nuclei with heparin for 40 min at 4 degrees C. The nuclear membrane pellet obtained in this...

Aspergillus sp PS 104, a soil isolate had excellent potential to solubilize rock phosphate in vitro. The process was influenced by the presence of various concentrations of local loess (red soil). The simultaneous occurrence, in our experiment, of high levels of solubilized phosphate and synthesized citric acid, together with the lowest reached pH values, confirmed the role of citric acid in th...