Effect of sodium trimetaphosphate on hydroxyapatite solubility: An in vitro study

This study evaluated the effect of different concentrations of sodium trimetaphosphate (TMP) with and without fluoride (F) on the concentration of calcium (Ca), phosphorus (P) and F in hydroxyapatite (HA). Synthetic HA powder (0.15 g) was suspended (n=6) in solutions (75 mL) of TMP at 0%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0% and 10% concentrations in the presence and absence of 100 ppm F and subjected to a pH-cycling process. The precipitates were filtrated, dried at 70° C for 24 h and ground onto a fine powder. The concentrations of F (KOH (CaF2) and HCl (FA) soluble), Ca (Arsenazo III), and P (molybdate method) in HA were determined. The Ca P, and Ca/P ratio data were subjected to Tukey's test and the F data were subjected to Student-Newman-Keuls test (p<0.05). The addition of TMP to the samples reduced F deposition to 98% (p<0.001). The groups containing 100 ppm F and 0.4% or 0.6% TMP exhibited a higher Ca concentration than the group containing only 100 ppm F (p<0.05). Furthermore, the HA treated with 0.2% and 0.4% TMP and 100 ppm F showed a higher Ca/P ratio than the other groups (p<0.001). In conclusion, TMP at 0.2%, 0.4% and 0.6% concentrations combined with F seemed to be able to precipitate HA with low solubility. However, especially at high concentrations, TMP interferes with F deposition on HA.

Matrix Effects on Water Analysis for Alkylphenols Using Solid Phase Extraction Gas Chromatography-Mass Spectrometry

Gas chromatography with mass spectrometry is frequently used for the quantification of many classes of substances, including alkylphenols. Alkylphenol polyethoxylates are nonionic surfactants used in a wide variety of industrial and consumer applications. Alkylphenol polyethoxylates can degrade to alkylphenols, which are endocrine disruptors. In analytical validation procedures, the most common parameters studied are the detection and quantification limits, linearity, and recovery; however, the matrix effects are sometimes neglected. Although some investigators have evaluated matrix effects, there is no consensus on how to evaluate them during method validation. In this study, the matrix effects of alkylphenol polyethoxylates (nonylphenol monoethoxylate, nonylphenol diethoxylate, octylphenol monoethoxylate, octylphenol diethoxylate) and alkylphenols (nonylphenol and octylphenol) were studied using solid phase extraction and gas chromatography-mass spectrometry analysis. For alkylphenol polyethoxylates, the matrix effects ranged from 16 to 4692%, whereas for alkylphenols (nonylphenol and octylphenol), the effects were insignificant. Therefore, constructing an analytical curve in the matrix for alkylphenol polyethoxylates is essential. © 2013 Copyright Taylor and Francis Group, LLC.

Continuous vs. segmented second-dimension system gradients for comprehensive two-dimensional liquid chromatography of sugarcane (Saccharum spp.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hydroxyapatite/beta-tricalcium phosphate and enamel matrix derivative for treatment of proximal class II furcation defects: a randomized clinical trial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nondecalcified Histologic Study of Bone Response to Titanium Implants Topographically Modified by Laser With and Without Hydroxyapatite Coating

The purpose of this study was nondecalcified histologic analysis of titanium implants modified by laser with and without hydroxyapatite. Implants with three modified surfaces were inserted into rabbit tibias: group 1, machined surface; group 2, irradiated (laser); and group 3, irradiated and hydroxyapatite coated (biomimetic method). The mean surface roughness (Ra) scores of groups 2 and 3 were higher than that of group 1. Bone-implant contact measurements at 30 and 60 days for groups 2 and 3 were higher than for group 1. Bone area at 30 and 60 days for group 2 was higher than for groups 1 and 3. Titanium implants modified by laser with and without hydroxyapatite exhibit increased early osseointegration.

Comprehensive two-dimensional gas chromatography combined to multivariate data analysis for detection of disease-resistant clones of Eucalyptus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assessing melatonin and its oxidative metabolites amounts in biological fluid and culture medium by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Validation of analytical methodology for quantification of cefazolin sodium pharmaceutical dosage form by high performance liquid chromatography to be applied for quality control in pharmaceutical industry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Analysis of ibuprofen enantiomers in rat plasma by liquid chromatography with tandem mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Analysis of rocuronium in human plasma by liquid chromatography-tandem mass spectrometry with application in clinical pharmacokinetics

Rocuronium (ROC) is a neuromuscular blocking agent used in surgical procedures which is eliminated primarily by biliary excretion. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for analysis of ROC in human plasma. Separation of ROC and IS (verapamil) was performed using an endcapped C-18 column and a mixture of water:acetonitrile:trifluoracetic acid (50:50:0.1, v/v) as mobile phase. Aliquots of 100 mu L of human plasma were extracted at pH 3, using dichloromethane. The lower limit of quantification of 5 ng/mL shows the high sensitivity of this method. Intra- and inter-assay precision (as relative standard deviation) was all <= 14.2% and accuracy (as relative standard error) did not exceed 10.1%. The validated method was successfully applied to quantify ROC concentrations in patients under surgical procedures up to 6 h after the administration of the 0.4-0.9 mg/kg ROC. The pharmacokinetic parameter estimations of ROC showed AUC/dose of 563 mu g min/mL, total clearance of 2.5 mL/min/kg, volume of distribution at steady state of 190 mL/kg and mean residence time of 83 min. (C) 2013 Elsevier B.V. All rights reserved.

Leishmanicidal activity of Brosimum glaziovii (Moraceae) and chemical composition of the bioactive fractions by using high-resolution gas chromatography and GC-MS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Silver Nanoparticles in a Hydroxyapatite Coating applied by Atmospheric Plasma Spray

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Kinome profiling of osteoblasts on hydroxyapatite opens new avenues on biomaterial cell signaling

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Metabolic profiling by ultra-performance liquid chromatography-mass spectrometry and parallel factor analysis for the determination of disease biomarkers in Eucalyptus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilização da HPLC (High Pressure Liquid Chromatography) para identificação do elemento antibacteriano extraído via hexano de Aristolochia gigantea

A ciência, principalmente a área da Farmacologia, vem ao longo dos anos desenvolvendo medicamentos eficazes e seguros para o tratamento médico de infecções bacterianas e seu sucesso reduz cada vez mais as mortalidades causadas por estes e outros microrganismos. Logo, a busca por novos compostos moleculares para o uso terapêutico é de grande importância para ampliar a gama de substâncias eficientes, buscando-se também menos efeitos colaterais, que podem ser disponibilizadas no mercado. Visando encontrar estes novos componentes, recorre-se às informações presentes em diversas áreas, principalmente na Etnobotânica, ciência que explora, verifica e armazena o conhecimento popular adquirido pelo homem através da sua interação com as plantas, sobre suas propriedades benéficas ou não, e usos mais comuns. A família Aristolochiales é uma das mais significativas no Brasil, chega a possuir 475 espécies. Este trabalho busca caracterizar o(s) composto(s) bactericidas presentes em A. gigantea através de extrações em hexano e acetonitrila como solventes, utilizando a HPLC (Hight Pressure Liquid Chromatography) para obter novas informações mais detalhadas destes. Testes de antibiograma averiguaram a eficiência das amostras durante os expermetos para Escherichia coli e Staphylococcus aureus