Previous studies have shown that freshwater pulmonate snails of the genus Lymnaea are exceedingly sensitive to chronic Pb exposure. An EC20 of <4microgl(-1)Pb for juvenile snail growth has recently been determined for Lymnaea stagnalis, which is at or below the current USEPA water quality criterion for Pb. We characterized ionoregulation and acid-base balance in Pb-exposed L. stagnalis (young a...

Phytoremediation is an effective method to remediate Pb-contaminated soils and root exudates play an important role in this process. Based on gas chromatography-mass spectrometry (GC-MS) and metabolomics method, this study focuses on the comparative metabolic profiling analysis of root exudates from the Pb-accumulating and non-accumulating ecotypes of Sedum alfredii treated with 0 and 50 μmol/L...

The effect of Pb(2+) ions on the Na(+),K(+)-ATPase was investigated in detail by means of steady-state fluorescence spectroscopy. Experiments were performed by using the electrochromic styryl dye RH421. It is shown that Pb(2+) ions can bind reversibly to the protein and do not affect the Na(+) and K(+) binding affinities in the E(1) and P-E(2) conformations of the enzyme. The pH titrations indi...

It is well documented that Pb solubility may be related to Fe chemistry in soils and enhanced Pb solubility may occur under certain reducing conditions; however, quantification of such relationships is unavailable. Based on metal classification, Pb (II) and Fe (II) are similar in some chemical characteristics. Thus, competition between Pb and Fe for ligands in soils may be important in determin...

The dinuclear title compound, [Pb(2)(C(10)H(6)NO(2))(2)(CH(3)COO)(2)(CH(3)OH)(2)], lies across an inversion center. The methanol-coordinated Pb(II) atom is chelated by the acetate anion as well as by the quinoline-2-carboxyl-ate anion. One O atom of the quinoline-2-carboxyl-ate anion bridges two symmetry-related Pb(II) atoms, forming the dinuclear compound. Aside from the six atoms connected to...

Pb(2+) complexes can attain several different topologies, depending of the shape of the Pb 6s6p lone pair. In this paper, we study structures with a bisdirected Pb lone pair with quantum mechanics (DFT) and QM/MM calculations. We study small symmetric Pb(2+) models to see what factors are needed to get a bisdirected lone pair. Two important mechanisms have been found: First, the repulsion of th...

OBJECTIVE Blood lead (B-Pb), one of the most used toxicological biomarker all kind, has serious limitations. Thus, the objective is to evaluate whether plasma lead (P-Pb) is more adequate. METHODS A long-term follow-up study of five cases of lead poisoning. P-Pb was analysed by inductively coupled plasma mass spectrometry. Kinetics after end of exposure was modelled. RESULTS P-Pb at severe ...

Past changes in seawater lead (Pb) isotopes record the temporal evolution of anthropogenic pollution, continental weathering inputs, and ocean current transport. To advance our ability to reconstruct this signature, we present methodological developments that allow us to make precise and accurate Pb isotope measurements on deep-sea coral aragonite, and apply our approach to generate the first P...

Two new lead(II) complexes [Pb(pcih)(bha)] (1) and [Pb(pcih)(NO3)] (2, Hpcih = 1,4-bis(3-pyridyl)-2,3-diazo-1,3-butadiene, Hbha = 2-hydroxybenzoic acid) have been synthesized by solvothermal methods and structurally characterized. The single-crystal X-ray data show that the coordination spheres of the Pb2+ ions in 1 and 2 are hemidirected with stereochemically active electron lone pairs. There ...