Revealing the toxicity of monovalent and trivalent thallium to medaka fish in controlled exposure conditions.

Thallium (Tl) is a rare earth element increasingly being used in high-technology manufacturing. It is also an emerging pollutant with high exposure and toxicity risks to aquatic ecosystems. Tl exists in the environment in a monovalent [thallous, Tl(I)] or trivalent [thallic, Tl(III)] state.

Establishing a quick screening method by using a microfluidic chip to evaluate cytotoxicity of metal contaminants.

Due to rapid industrialization and urbanization, the environment is exposed to many chemicals from natural or anthropogenic sources. The contaminants impact eco-system and human health via food chain. Animals, including humans, are likely to accumulate contaminants in their bodies from direct exposure or feeding behavior, resulting in toxicity.

Characterization and modeling analysis for metal-semiconductor-metal GaAs diodes with Pd/SiO₂ mixture electrode.

Characterization and modeling of metal-semiconductor-metal (MSM) GaAs diodes using to evaporate SiO₂ and Pd simultaneously as a mixture electrode (called M-MSM diodes) compared with similar to evaporate Pd as the electrode (called Pd-MSM diodes) were reported. The barrier height (φ(b)) and the Richardson constant (A*) were carried out for the thermionic-emission process to describe well the current transport for Pd-MSM diodes in the consideration of the carrier over the metal-semiconductor barrier. In addition, in the consideration of the carrier over both the metal-semiconductor barrier and the insulator-semiconductor barrier simultaneously, thus the thermionic-emission process can be used to describe well the current transport for M-MSM diodes.

Stabilization or oxidation of nanoscale zerovalent iron at environmentally relevant exposure changes bioavailability and toxicity in medaka fish.

Nanoscale zerovalent iron (nZVI)-based nanotechnologies are increasingly being used for environmental remediation; however, the fate and ecotoxicologic effects of nZVI remain unclear. Larvae of medaka fish (Oryzias latipes) underwent 3-14 days' aqueous exposure to thoroughly characterized solutions containing carboxymethyl cellulose (CMC)-stabilized nZVI, bare nZVI, nanoscale iron oxide (nFe(3)O(4)) or ferrous ion [Fe(II)(aq)] at μg/L-mg/L levels to assess the causal toxic effect(s) of iron nanoparticles (NPs). Acute larval mortality was decreased in the order of Fe(II)(aq) > CMC-nZVI > nZVI > nFe(3)O(4).

Toxicity assessments of nanoscale zerovalent iron and its oxidation products in medaka (Oryzias latipes) fish.

Iron-based nanotechnologies are increasingly used for environmental remediation; however, toxicologic impacts of iron nanoparticles on the aquatic ecosystem remain poorly understood. We treated larvae of medaka fish (Oryzias latipes) with thoroughly characterized solutions containing carboxymethyl cellulose (CMC)-stabilized nanoscale zerovalent iron (nZVI), aged nanoscale iron oxides (nFe-oxides) or ferrous ion (Fe[II]) for 12-14 days' aqueous exposure to assess the causal toxic effect(s) of iron NPs on the fish. With the CMC-nZVI solution, the dissolved oxygen level decreased, and a burst of reactive oxygen species (ROS) was generated as Fe(II) oxidized to ferric ion (Fe[III]); with the other two iron solutions, these parameters did not significantly change.