Introduction Let C be a convex bounded body in the n-dimensional Euclidean space E, and let B be its boundary. We use Busemann's notations: E(a,b) for the segment {(1 — p)a + pb: 0 < p ^ 1} from a to b, and S(z, p) for the sphere {x: \\z — x\\ = p). We now recall the definition of Hammer's associated bodies C(r). Let Cb(r) be the set obtained from C by a similitude transformation with a ratio r...

Lead (Pb(2+)) exposure continues to be a significant public health problem. Therefore, it is vital to have a continuous epidemiological dataset for a better understanding of Pb(2+) toxicity. In the present study, we have exposed stem cells isolated from deciduous and permanent teeth, periodontal ligament, and bone marrow to five different types of Pb(2+) concentrations (160, 80, 40, 20, and 10 ...

Lead exposure represents a medical and public health emergency, especially in children consuming high amounts of lead-contaminated flake paints. It may also cause hematological effects to people of all ages. Recent studies in our laboratory have indicated that apoptosis may be associated with the lead-induced oxidative stress and DNA damage. However, the mechanisms underlying its effect on lymp...

The reactions of Pb(N0 ) and Pb(SCN)2 with 2-(aminomethy1)pyridine (C H N = L) yielded colourless crystals of L Pb(N0 ) ( I ) and L Pb(SCN) , (2), respectively. Their structures were determined by X-ray crystallography. Crystal data: 1, monoclinic, P2 /c, a = 9.263 (4) ?, b = 7.783 (2) ?, c = 6.692 (3) ?, ? = 101.26 (2)?, Z = 2, Mo K?, 1540 observed (I > 2.5 ?(I) data (22 ? C), R = 0...

The title complex, [Pb(C(8)H(5)N(2)O(2)S)(2)](n), consists of one Pb(II) ion located on a crystallographic twofold axis and two symmetry-related 2-amino-1,3-benzothia-zole-6-carboxyl-ate (ABTC) ligands. The central Pb(II) ion has a (4 + 2) coordination by four O atoms of the two ABTC ligands and two weaker Pb-S bonding inter-actions (Pb-S secondary bonds) from S atoms of other two neighbouring ...

The asymmetric unit of the title coordination polymer, [Pb(2)(C(8)H(2)NO(6))(OH)](n), contains two crystallographically independent Pb(II) ions, one pyridine-2,4,6-tricarboxyl-ate (ptc) trianion and one hydroxide anion. One of the Pb(II) atoms is coordinated by one pyridine N and four carboxyl-ate O atoms from the ptc trianion and a hydroxide O atom in a distorted octa-hedral geometry. The othe...

Neodymium model ages for fine-grained formations of the Paleoproterozoic Huronian Supergroup (McKim, Pecors, Gowganda, Gordon Lake) range from 3.00 to 2.55 Ga and indicate a provenance dominated by the Late Archean Superior Province to the north and west. The stratigraphically highest unit (Gordon Lake Formation) has a distinctive Nd-isotopic composition, with TDM being 100-400 Ma younger than ...

We have developed a technique for the highly selective and sensitive detection of Pb(2+) and Hg(2+) using a thrombin-binding aptamer (TBA) probe labeled with the donor carboxyfluorescein (FAM) and the quencher 4-([4-(dimethylamino)phenyl]azo)benzoic acid (DABCYL) at its 5' and 3' termini, respectively. The TBA has a random coil structure that changes into a G-quartet structure and a hairpin-lik...

Lead (Pb) is recognized as one of the most pervasive environmental health concerns in the industrialized world. While there has been a substantial reduction in the use of Pb in gasoline, water pipes, and Pb-based residential paint, residual Pb from their use is still in the environment and constitutes an important source of Pb in the atmosphere, water, and soil. Soil acts as a sink for these an...