droxide by calcium carbonate. The calcium carbonate dosage ranged from 3 to 6 g/day. They found that low-calcium dialysate induces a negative calcium balance during hemodialysis (HD) with a worsening of SHPTH and concluded that a change in the current policy of the treatment of renal osteodistrophy can be necessary to prevent these alterations. For 1 yr, we studied the effect oflow-calcium dial...

BACKGROUND We characterize a novel nanocomposite that acts as an efficient anticancer agent. METHODS This nanocomposite consists of zinc layered hydroxide intercalated with protocatechuate (an anionic form of protocatechuic acid), that has been synthesized using a direct method with zinc oxide and protocatechuic acid as precursors. RESULTS The resulting protocatechuic acid nanocomposite (PA...

Acutolysin A, which is isolated from the snake venom of Agkistrodon acutus, is a member of the SVMPs subfamily of the metzincin family, and it is a snake venom zinc metalloproteinase possessing only one catalytic domain. The catalytic zinc ion, in the active site, is coordinated in a tetrahedral manner with three imidazole nitrogen atoms of histidine and one oxygen atom. It is uncertain whether...

In this thesis, quantum chemical methods have been used to shed light on the reaction mechanisms of several dinuclear zinc enzymes. The enzymes studied are involved in the hydrolysis of phosphates, amides, and carboxylic esters, namely RNase Z, Dihydroorotase (DHO), and N-acyl homoserine lactone hydrolase (AHL lactonase). The density functional method B3LYP, together with quite large active sit...

We have identified important chemical reactions that control the fate of metal-contaminated estuarine sediments if they are left undisturbed (in situ) or if they are dredged. We combined information on the molecular bonding of metals in solids from X-ray absorption spectroscopy (XAS) with thermodynamic and kinetic driving forces obtained from dissolved metal concentrations to deduce the dominan...

The hydrate tetrabutylammonium hydroxide ionic liquid is an efficient ILP for the controlled fabrication of zinc oxide particles with unusual nanostructures.

electroplating industry wastewater (eiw) characterized by high chemical oxygen demand (cod) is a big source of water and air contamination with heavy metals. the formation of cyanide complex with heavy metals is responsible for its elevated cod. the concentration of heavy metals in eiw can be removed by the use of different precipitating agents (sulfide and hydroxide). but the major bottleneck ...

the kinetics of zn sorption by ten calcareous soils of iran were measured and fitted to several equations (zero-, first-, second-, third-order, parabolic diffusion, simple elovich, and exponential equations). two initial concentrations of zinc i.e. 20 and 80 mg zn l-1 were used and observations were carried out for 100 hours. the time required to reach the near equilibrium state was about 24 ho...

This paper studies the influence of two pH modifiers, namely sodium hydroxide (NaOH) and sodium carbonate (Na2C03), on the flotation of celestite ore using sodium oleate as the collector and sodium silicate (Na2SiO 3) as the depressant. The use of Na2CO 3 provides the best results for the concentration of celestite, under the same experimental conditions. © 1998 Elsevier Science Ltd. All rights...

The effect of alkalinity on nitrifying biofilm activity was determined by collecting 21-day-old biofilm samples from the top of a full-scale nitrifying trickling filter and evaluating bench-scale nitrate plus nitrite generation rates at (1) various initial carbonate alkalinity concentrations and (2) with four types of available alkalinity: carbonate only, phosphate only, phosphate plus hydroxid...