Validation of Analytical Method for Determination of Thallium in Rodent Plasma and Tissues by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).

Thallium (Tl) can be released as a byproduct of smelting, mining, and other industries, causing human exposure. There are knowledge gaps on the toxicity of thallium compounds, so the National Toxicology Program is investigating the toxicity of thallium (I) sulfate in rodents. We developed and validated a method to quantitate Tl in rodent plasma and secondary matrices.

The Role of Self-Improving Tutoring Systems in Fostering Pre-Service Teacher Self-Regulated Learning.

Computer-based learning environments serve as a valuable asset to help strengthen teacher preparation and preservice teacher self-regulated learning. One of the most important advantages is the opportunity to collect ambient data unobtrusively as observable indicators of cognitive, affective, metacognitive, and motivational processes that mediate learning and performance. Ambient data refers to teacher interactions with the user interface that include but are not limited to timestamped clickstream data, keystroke and navigation events, as well as document views.

Mechanisms of orthophosphate removal from water by lanthanum carbonate and other lanthanum-containing materials.

Removing phosphorus (P) from water and wastewater is essential for preventing eutrophication and protecting environmental quality. Lanthanum [La(III)]-containing materials can effectively and selectively remove orthophosphate (PO) from aqueous systems, but there remains a need to better understand the underlying mechanism of PO removal. Our objectives were to 1) identify the mechanism of PO removal by La-containing materials and 2) evaluate the ability of a new material, La(CO), to remove PO from different aqueous matrices, including municipal wastewater.

Quantitation of Total Vanadium in Rodent Plasma and Urine by Inductively Coupled Plasma - Mass Spectrometry (ICP-MS).

Human exposure to vanadium (V) is anticipated because it is a drinking water contaminant. Due to limited data on soluble V salts, the National Toxicology Program is investigating the toxicity in rodents following drinking water exposure. Measurement of internal V dose allows for interpretation of toxicology data.

Total sulfur analysis of fine particulate mass on nylon filters by ICP-OES.

Sulfur (S) and sulfate (SO ) in fine particulate matter (PM ) are monitored by the Interagency Monitoring of Protected Visual Environments (IMPROVE) network at remote and rural sites across the United States. Within the IMPROVE network, S is determined from X-ray fluorescence (XRF) spectroscopy from a Teflon filter, and SO is determined via ion chromatography (IC) from a nylon filter. Differences in S and SO estimates may indicate the presence of organosulfur (OS) species or biases between sampling and analytical methods.

Disposition of intravenously or orally administered silver nanoparticles in pregnant rats and the effect on the biochemical profile in urine.

Few investigations have been conducted on the disposition and fate of silver nanoparticles (AgNP) in pregnancy. The distribution of a single dose of polyvinylpyrrolidone (PVP)-stabilized AgNP was investigated in pregnant rats. Two sizes of AgNP, 20 and 110 nm, and silver acetate (AgAc) were used to investigate the role of AgNP diameter and particle dissolution in tissue distribution, internal dose and persistence.

Development of an analytical method for assessment of silver nanoparticle content in biological matrices by inductively coupled plasma mass spectrometry.

Silver nanoparticles (AgNPs) are a broad class of synthetic nanoparticles that are utilized in a wide variety of consumer products as antimicrobial agents. Despite their widespread use, a detailed understanding of their toxicological characteristics and biological and environmental hazards is not available. To support research into the biodistribution and toxicology of AgNPs, it is necessary to develop a suitable method for the assessment of AgNP content in biological samples.