No abstract

No abstract

Fully dispersible, cationic ultrasmall (7 nm diameter) superparamagnetic iron oxide nanoparticles, exhibiting high relaxivity (178 mM −1 s −1 in 0.47 T) and no acute or subchronic toxicity in Wistar rats, were studied and their suitability as contrast agents for magnetic resonance imaging and material for development of new diagnostic and treatment tools demonstrated. After intravenous injection (10 mg/kg body weight), they circulated throughout the vascular system causing no microhemorrhage or thrombus, neither inflammatory processes at the mesentery vascular bed and hepatic sinusoids (leukocyte rolling, adhesion, or migration as evaluated by intravital microscopy), but having been spontaneously concentrated in the liver, spleen, and kidneys, they caused strong negative contrast. The nanoparticles are cleared from kidneys and bladder in few days, whereas the complete elimination from liver and spleen occurred only after 4 weeks. Ex vivo studies demonstrated that cationic ultrasmall superparamagnetic iron oxide nanoparticles caused no effects on hepatic and renal enzymes dosage as well as on leukocyte count. In addition, they were readily concentrated in rat thigh by a magnet showing its potential as magnetically targeted carriers of therapeutic and diagnostic agents. Summarizing, cationic ultrasmall superparamagnetic iron oxide nanoparticles are nontoxic and efficient magnetic resonance imaging contrast agents useful as platform for the development of new materials for application in theranostics.

Calibration aiming at quantitative analysis of complex samples is one of the most difficult issues in laser-induced breakdown spectroscopy (LIBS) due to matrix interferences, heterogeneity, and sample particle size effects.

Lead is a highly neurotoxic chemical element known for reducing intelligence quotient (IQ) and promoting antisocial behavior in children and adolescents, while cadmium is a carcinogenic bioaccumulative element. Contaminated foods and beverages are the most common routes of exposure. The objective of this study was to determine Cd and Pb concentrations in colored plastic utensils for use by children and to measure the speci c migration of these elements into beverages and foods. Pb and Cd concentrations were determined using a handheld XRF. Speci c migration tests were conducted using the simulant solutions. Migration levels were determined by ICP-MS and migration tests for Pb were also performed on actual samples GF-AAS determination. Utensils (n=87) were purchased for containing Cd and/or Pb concentrations above permitted limits. The mean of Pb and Cd were 1110 and 338 ppm respectively. For speci c migration assays, Pb levels were 187, 13 and 380 times above the permitted limit for acetic acid, water and orange juice, respectively. Cd levels 50 and 2.4 times above the permitted limit for acetic acid and water, respectively. The districts where the utensils were purchased were grouped according to their Social Vulnerability Index and compared using ANOVA. Results revealed a group difference in mean Pb levels for low versus medium/high social vulnerability (p = 0.006). The ndings corroborate the initial hypothesis that these utensils constitute a major source of exposure to PTEs such as Cd and Pb.