11 research outputs found
Tribromide ion supported on boehmite nanoparticles as a reusable catalyst for organic reactions
Urinary arsenic, cadmium, manganese, nickel, and vanadium levels of schoolchildren in the vicinity of the industrialised area of Asaluyeh, Iran
Asaluyeh is one of the most heavily industrialised
areas in the world where gas, petrochemical, and many downstream
industries are located. This study aims to survey the
biomonitoring of four metals and one metalloid in children
living in the vicinity of Asaluyeh area. To do this, we analysed
the creatinine-adjusted urinary levels of arsenic (As), cadmium
(Cd), vanadium (V), manganese (Mn), and nickel (Ni) in
184 elementary schoolchildren (99 boys and 85 girls) living in
Asaluyeh and compared them with a reference population.
The comparisons were done for two seasons (spring and fall).
The results showed that in the case area (Asaluyeh), the levels
of As, V, Mn, and Ni were significantly higher and that of Cd
was not significantly higher than the reference city for both
seasons. The mean concentration of metal(loid)s in Asaluyeh
(case) and Sadabad (reference) area as μg g−1 creatinine was
As 2.90 and 2.24, V 0.06 and 0.03, Mn 0.28 and 0.25, Ni 0.54
and 0.29, and Cd 0.31 and 0.28 in spring and As 3.08 and
2.28, V 0.07 and 0.03, Mn 0.30 and 0.26, Ni 0.91 and 0.30,
and Cd 0.36 and 0.31 in the fall. Seasonal variations played a
key role in determining urinary metal(loid) concentration, as
we saw the significant level of As, Cd, V, and Ni in fall than in
spring. With regard to the impact of gender on the absorption
and accumulation of urinary metal(loid)s, boys showed higher
levels of the studied elements, especially for As, than girls as
outdoor activities are more popular among boys. Due to the
values being lower than those reported in literature, more research
is needed on various population groups and other exposure
sources in order to judge whether living in the vicinity
of the gas and petrochemical industries in Asaluyeh is a threat
to nearby residents
Nano aluminium nitride as a solid source of ammonia for the preparation of hantzsch 1,4-dihydropyridines and bis-(1,4-dihydropyridines) in water via one pot multicomponent reaction
Pd–<i>S</i>-methylisothiourea supported on magnetic nanoparticles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions
Tribromide ion immobilized on magnetic nanoparticles as an efficient catalyst for the rapid and chemoselective oxidation of sulfides to sulfoxides
Polyvinylpolypyrrolidoniume tribromide (PVP-Br3) as efficient and metal-free agent for the selective oxidation of alcohols, trimethylsilyl ethers and oximes under mild conditions
Polyvinylpolypyrrolidoniume tribromide (PVP-Br3) was found to be a metal-free and highly efficient oxidizing polymer for the selective oxidation of a variety of benzylic alcohols, deprotection and selective oxidation of trimethylsilyl ethers and oximes to the corresponding aldehydes and ketones at room temperature in moderate to high yields. The main advantages of this procedure are selective oxidation, efficient, milder reaction conditions, shorter reaction times, and easier work-up
Silica sulfuric acid-coated Fe3O4 nanoparticles as high reusable nanocatalyst for the oxidation of sulfides into sulfoxides, protection and deprotection of hydroxyl groups using HMDS and Ac2O
Oxidation of sulfides, acetylation of alcohols and phenols and selective trimethylsilylation of primary and secondary benzyl alcohols are carried out using silica sulfuric acid-coated Fe3O4 magnetic nanoparticles (SSA@MNPs) as a stable, efficient and magnetically recoverable nanocatalyst. Also, deprotection of silyl ethers was reported in ethanol at room temperature in the presence of SSA@MNPs as a magnetic nanocatalyst. The magnetic nanocatalyst was characterized by FT-IR spectroscopy, TGA, XRD and SEM techniques. The catalyst was easily separated with the assistance of an external magnetic field from the reaction mixture and reused for several consecutive runs without significant loss of its catalytic efficiency