in the present work, the extraction of zinc from a sphalerite concentrate using sodium nitrate as an oxidant in a sulfuric acid solution was investigated. the effective parameters such as the temperature, sulfuric acid and sodium nitrite concentrations, stirring speed, particle size, and solid/liquid (s/l) ratio were analyzed. the dissolution rate increased with increase in the sulfuric acid an...

the hallmarks of leukocyte adhesion deficiency (lad) are defects in the leukocyte adhesion process, marked leukocytosis and recurrent infections. these molecular and clinical manifestations result from an impaired step in the inflammatory process, namely, the emigration of leukocytes from the blood vessels to sites of infection, which requires adhesion of leukocytes to the endothelium. over las...

easily prepared nanozno was found to be as an efficient catalyst in the synthesis of 1,4-dhps via four-component reaction of 1,3-dicarbonyls, aldehydes and ammonium carbonate in water at 60 °c. the prepared nanozno was characterized by xrd and ft-ir analysis, while the determined specific surface area of nano catalyst by bet method was 33 m2/g.

an efficient three-component reaction of dialkyl acetylendicarboxylates and 2-pyrrolidin in the presence of triphenylphosphine produces dialkyl 2-(2-pyrrolidin-n-yl)-3-(triphenylphosphanylidene)succinate. these phosphoranes undergo mild intramolecular wittig reaction to produce dialkyl (e)-2-(4,5-dihydro-3h-pyrrol-2-yl)fumarate in excellent yields.

background toxoplasmosis is a parasitic disease caused by the protozoan toxoplasma gondii. this parasite infects most of warm-blooded animals, including birds. turkeys are one of these animals which might be infected by this parasite. little is known about the prevalence of t. gondii in turkeys in iran. objectives the current study aimed to evaluate the rate of toxoplasma infection in turkeys i...