Search results for "hate"

Hydrolysis of Phytic Acid by Microwave Treatment: Application to Phytic Acid Analysis in Pharmaceutical Preparations

1998

Abstract The acid hydrolysis of phytic acid in a Teflon reactor using a domestic microwave oven has been studied and compared with other reported procedures. In 0.44 M HCl quantitative hydrolysis was achieved with six heating stages of 2 min each. A lower yield was obtained with H 2 SO 4 and HNO 3 . The analytical use of this hydrolysis to determine phytic acid by indirect determination of phosphate has been demonstrated by analysis of three pharmaceutical formulations. No sample pretreatment other than obtaining a homogeneous suspension was necessary.

Selective Hydrogenation of 1,3-Butadiene to 1-Butene by Pd(0) Nanoparticles Embedded in Imidazolium Ionic Liquids

2005

The reduction of Pd(acac)2 (acac=acetylacetonate), dissolved in 1-n-butyl-3-methylimidazolium hexafluorophosphate (BMI⋅PF6) or tetrafluoroborate (BMI⋅BF4) ionic liquids, by molecular hydrogen (4 atm) at 75 °C affords stable, nanoscale Pd(0) particles with sizes of 4.9±0.8 nm. Inasmuch as 1,3-butadiene is at least four times more soluble in the BMI⋅BF4 than butenes, the selective partial hydrogenation could be performed by Pd(0) nanoparticles embedded in the ionic liquid. Thus, the isolated nanoparticles promote the hydrogenation of 1,3-butadiene to butenes under solventless or multiphase conditions. Selectivities up to 97% in butenes were observed in the hydrogenation of 1,3-butadiene by Pd…

Formation of a Porous Zirconium Oxo Phosphate with a High Surface Area by a Surfactant-Assisted Synthesis

1996

Oxygen isotope analysis of human bone phosphate evidences weaning age in archaeological populations

2015

Here we report bone phosphate oxygen (δ(18)Op) values from perinates/neonates and infants ( 50 years), have δ(18)Op values consistent with the consumption of local modern drinking water. The implications of this study for the reconstruction of weaning practices in archaeological populations are discussed, including variations observed with bone δ(15)Ncoll and δ(18)Op co-analysis and the influence of culturally-modified drinking water and seasonality. The use of this method to explore human mobility and palaeoclimatic conditions are also discussed with reference to the data presented.

Evaluation of the factors affecting direct polarization solid state (31)P-NMR spectroscopy of bulk soils

2008

Summary 31 P-NMR spectroscopy on bulk soils is a powerful tool for the identification of the different phosphorus forms in soils and for the evaluation of the dynamics of soil P. Up to now the majority of the papers dealt with liquid state 31 P-NMR spectroscopy on soluble soil organic substances. Only few papers were addressed to the study of the different phosphorus forms directly in bulk soils. In the present paper, some organic and inorganic phosphates of known structures, which are likely to be present in soil systems, were studied by direct polarization (DP) magic angle spinning (MAS) 31 P-NMR spectroscopy in order to understand the electronic factors responsible for chemical shifts of…

1,4,8,11-Tetrakis(4-ferrocenyl-3-azabutyl)-1,4,8,11-tetraazacyclotetradecane as a ferrocene-functionalised polyammonium receptor for electrochemical …

1999

The interaction of the ferrocene-functionalised polyaza receptor 1,4,8,11-tetrakis(4-ferrocenyl-3-azabutyl)-1,4,8,11-tetraazacyclotetradecane (L1) with sulfate, phosphate and ATP has been studied potentiometrically in THF–water 70∶30 v/v (0.1 mol dm–3 tetrabutylammonium perchlorate, 25 °C). The molecular structure of the free receptor has been determined by single-crystal X-ray procedures. An electrochemical study on L1 as a function of the pH has been carried out in THF–water 70∶30 v/v in the presence of the sulfate, phosphate and ATP anions. The potential use of L1 as an anion sensing receptor is discussed in terms of the electrochemical and potentiometric data and its behaviour is compar…

Oxygen isotopes in mammal bone phosphate: A new tool for paleohydrological and paleoclimatological research?

1984

Abstract Oxygen isotope analyses of water in blood of humans and domestic pigs indicate that the oxygen isotope fractionation effects between ingested water and body water are the same in all specimens of the same species. The δ 18 O of body water has been shown to vary linearly with the mean δ 18 O of local meteoric water. This conclusion also holds for the bone phosphate. Thus, δ 18 O ( PO 3− 4 ) values of unaltered fossil bones from humans and domestic pigs can be used to reconstruct the δ 18 O values of local meteoric waters during the life-times of the mammals. Such data can be used for paleohydrological and paleoclimatological studies both on land and at sea.

ChemInform Abstract: K2AuPS4 (I), Tl2AuPS4 (II), K2AuAsS4 (III), and KAu5P2S8 (IV): Syntheses, Structures, and Properties of Quaternary Gold Thiophos…

2010

The Significance of Low O2-Tensi0ns in the Brain Cortex for Occurrence of Metabolic Alterations under Critical Flow Conditions

1985

A reduction in the 02 supply to the brain cortex leads to O2 deficiency and curtailment of neuronal metabolism and function as soon as a minimal cellular O2 tension of 0.1 – 1 mmHG (13 – 133 Pa) can no longer be maintained (Chance et al., 1964; Grote 1967). The hypoxia-induced metabolic alterations are characterized by decreased tissue levels of the energy-rich phosphate compounds PCr and ATP. In addition, elevated concentrations of lactate, pyruvate and NADH and an increase in the lactate/pyruvate ratio and in the NADH/NAD+ ratio are to be expected (Duffy et al., 1972; Granholm and Siesjo 1969; Granholm et al., 1969; Granholm and Siesjo 1971; Grote 1978; Grote and Schubert 1982; Norberg an…

Comparative analysis of the remineralization potential of CPP–ACP with Fluoride, Tri-Calcium Phosphate and Nano Hydroxyapatite using SEM/EDX – An in …

2019

Background In recent years, the non-invasive management of non cavitated caries lesions using remineralization systems to repair the enamel have received more attention from the scientific community. Aim: To quantitatively evaluate the remineralization potential of Casein phosphopeptide-amorphous calcium phosphate-fluoride(CPP-ACPF), Tri-calcium phosphate(TCP) & Nano-hydroxyapatite(nHAP) using Scanning Electron Microscopy(SEM) and Energy dispersive X-ray Analysis(EDX). Material and Methods 40 enamel specimens were prepared, and immersed in demineralising solution at a pH of 4.4 for 96 hours at 37°C, to induce artificial carious lesions. Remineralization was carried out for a period of 30 da…