This study compared the extractability of Cd, Cu, Ni, Pb, and Zn by 8 extraction protocols for 22 representative rural soils in Taiwan and correlated the extractable amounts of the metals with their uptake by Chinese cabbage for developing an empirical model to predict metal phytoavailability based on soil properties. Chemical agents in these protocols included dilute acids, neutral salts, and ...

Regulation of metal ion homeostasis is essential to bacterial cell survival, and in most species it is controlled by metal-dependent transcriptional regulators. In this study, we describe a Corynebacterium diphtheriae ferric uptake regulator-family protein, Zur, that controls expression of genes involved in zinc uptake. By measuring promoter activities and mRNA levels, we demonstrate that Zur r...

Flexible anionic metal-organic frameworks (MOFs) are transformed into neutral heterobimetallic systems via single-crystal-to-single-crystal processes invoked by cation insertion. These transformations are directed by cooperative bond breakage and formation, resulting in expansion or contraction of the 3D framework by up to 33% due to the flexible nature of the organic linker. These MOFs display...

The biotic ligand model considers the biological and geochemical complexities that affect metal exposure. It relates toxicity to the fraction of physiological active sites impacted by reactive metal species. The biodynamic model is a complementary construct that predicts bioaccumulation and assumes that toxicity occurs when influx rates exceed rates of loss and detoxification. In this paper we ...

Vein loading in unifoliate leaves of white bean seedlings exposed to excess Co(2+), Ni(2+), or Zn(2+) for 1 to 4 days was studied by incubating leaf discs in [(14)C]sucrose. The discs from plants exposed to metal exhibited an increased total uptake of radiosucrose but reduced vein loading. Differences between treatments due to infiltration of disc margins were eliminated by analyzing 7-millimet...

BACKGROUND Occupational exposure to cobalt is well established in hard metal manufacture. Cobalt is known to cause contact allergy, asthma, hard metal lung disease, and lung cancer. The relationship between skin exposure and uptake determined in blood has not been extensively investigated. OBJECTIVE To examine whether skin and inhalable air exposure to cobalt contributes to uptake, determined...

The effect of the presence of different anions on the biosorption of La(3+) (Lanthanum) using Sargassum polycystum Ca-loaded biomass was studied in this work. Different types of metal salts were used, such as nitrate, sulphate and chloride. The presence of the anion sulphate decreased the metal uptake for tested pH values of 3--5 when compared to the nitrate and chloride systems. The presence o...

The present study is aimed at assessing the ability of Pseudomonas sp. AN29 to uptake Hg from the metal contaminated environment. The minimum inhibitory concentration (MICs) of Hg was 500 μg/ml. Pseudomonas sp. AN29 could tolerate Pb (600 g/ml), Cu (200 g/ml), Cd (50 g/ml), Zn (50 g/ml), Ni (550 g/ml) and Cr (150 g/ml). The isolate showed typical growth curve but phases (lag and log) exte...

The amyloid hypothesis states that amyloid beta protein (Abeta) plays a major causal role in the onset of Alzheimer's disease. Toxicity of Abeta can be modified by metal ions. Two mechanisms by which such Abeta and metal ions could interact are by enhanced oxidative stress or by altered fibrillation. Specifically, Abeta fibrillation is increased by aluminum (Al) and copper (Cu) and Al also incr...

Metal cation homeostasis is essential for plant nutrition and resistance to toxic heavy metals. Many plant metal transporters remain to be identified at the molecular level. In the present study, we have isolated AtNramp cDNAs from Arabidopsis and show that these genes complement the phenotype of a metal uptake deficient yeast strain, smf1. AtNramps show homology to the Nramp gene family in bac...