Metalloporphirins; Cu(TPP), Mn(TPP)Cl, CO(TPP), Fe(TPP)Cl, zn(TPP) and Mn(OBP)Cl catalyze region and chemoselective silylation of hydroxyl groups with HMDS. Fe(TPP)Cl is the most effective catalyst and silylation occurs immediately in its presence at room temperature.

Manganese doped nanocrystalline willemite powder phosphors Zn(2-x)Mn(x)SiO(4) (0.1<or=x<or=0.5) have been synthesized by a low-temperature initiated, self-propagating, gas producing solution combustion process. The phosphors have been characterized by using x-ray diffraction (XRD), energy dispersive spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), elec...

pollution of water and soils by heavy metals is an emerging problem in industrialized countries.the present study was conducted to investigate the heavy metals concentration in water and sedimentsamples from ship breaking sites of sitakunda to assess the potential ecological risk posed by heavy metalusing different methods. heavy metals concentration was analyzed by atomic absorption spectrosco...

Background: Trace elements play important roles in carbohydrates and lipids metabolism. According to some studies, trace elements concentrations are different in serum and urine of diabetic and healthy population. In this work, for the first time six trace elements (Zn, Cu, Mg, Mn, Cr, Se) concentration of scalp hair, nail, urine and serum of diabetes mellitus patients and control group were an...

Understanding mechanisms that control plant root metal assimilation in soil is critical to the sustainable management of metal-contaminated land. With the assistance of the synchrotron X-ray fluorescence technique, this study investigated possible mechanisms that control the localization of Fe, Cu, Mn, Pb and Zn in the root tissues of Typha latifolia L. collected from a contaminated wetland. Me...

Heavy metals are transported to rice grains via the phloem. In rice nodes, the diffuse vascular bundles (DVBs), which enclose the enlarged elliptical vascular bundles (EVBs), are connected to the panicle and have a morphological feature that facilitates xylem-to-phloem transfer. To find a mechanism for restricting cadmium (Cd) transport into grains, the distribution of Cd, zinc (Zn), manganese ...

Genotoxicity of Cu and Zn was assessed by use of the micronucleus (MN) test on Vicia faba roots. Plants were exposed to various leachates of raw and anaerobically digested pig slurry, with maximum total concentrations of 200microM Cu and 600microM Zn. The results indicated stabilisation of the organic matter during anaerobic digestion of the slurry and bioconversion of some phytotoxic organic c...

One of the major classes of antioxidant enzymes, which protect the cellular and subcellular components against harmful reactive oxygen species (ROS), is superoxide dismutase (SOD). SODs play pivotal role in scavenging highly reactive free oxygen radicals and protecting cells from toxic effects. In Oryza sativa three types of SODs are available based on their metal content viz. Cu-Zn SOD, Mn SOD...

Mycobacterium tuberculosis pyrazinamidase (PZAse) is a key enzyme to activate the pro-drug pyrazinamide (PZA). PZAse is a metalloenzyme that coordinates in vitro different divalent metal cofactors in the metal coordination site (MCS). Several metals including Co(2+), Mn(2+), and Zn(2+) are able to reactivate the metal-depleted PZAse in vitro. We use quantum mechanical calculations to investigat...