Search results for "fluorides"
showing 10 items of 38 documents
Prenatal exposure to fluoride and neuropsychological development in early childhood: 1-to 4 years old children
2022
[EN]BACKGROUND: Cross-sectional and prospective studies have provided evidence of the neurotoxic effect of early exposure to fluoride (F) in pregnancy. It has been negatively associated with cognitive development during childhood, with most research conducted in areas with high F levels in community drinking water (CDW). METHOD: Data from 316 to 248 mother-child pairs from the Infancia y Medio Ambiente (Childhood and Environment, INMA) birth cohort project with maternal urinary F level adjusted for creatinine (MUFcr) measurements in the first and third trimesters of pregnancy. Children's cognitive domains and intelligence indexes were evaluated using the Bayley Scales (age of 1) and the McC…
Dietary Habits in a Child Population in Relation to Caries Experience
2008
Sugar consumption in Spain has remained constant at around 80 g/day since the 1970s. Although intake as sugar has fallen considerably, to around 13.5 g/person/day, the intake in processed foods has risen. Meanwhile, caries prevalence is falling or stabilizing. This situation is common in developed countries, where the impact of diet on caries has altered, probably through greater use of fluoridated products. In the Valencia region, children habitually eat sugary foods and drinks and snacks that contain starches or sugars and starches. The present study analyzed the association between caries experience, quantified as the sum of the dfs and DMFS indices, and the consumption of cariogenic foo…
MI paste plus and PreviDent fluoride varnish appear no more effective than normal home care for improving the appearance of white spot lesions.
2013
Article Title and Bibliographic Information Effectiveness of MI Paste Plus and PreviDent fluoride varnish for treatment of white spot lesions: a randomized controlled trial. Huang GJ, Roloff-Chiang B, Mills BE, Shalchi S, Spiekerman C, Korpak AM, Starrett JL, Greenlee GM, Drangsholt RJ, Matunas JC. Am J Orthod Dentofacial Orthop 2013;143:31-41. Reviewer Carmen Llena-Puy Purpose/Question The authors' aim was to compare the effectiveness of MI Paste Plus and PreviDent fluoride varnish (22,600 ppm of fluoride) with a standard oral hygiene regimen with toothpaste (1100 ppm of fluoride; Colgate Oral Pharmaceuticals)--control group--in improving the appearance of white spot lesions (WSLs) after o…
Fluoride-induced precipitates on enamel surface and subsurface areas visualised by electron microscopy and confocal laser scanning microscopy
1997
The present study examined the enamel surface after in vitro topical treatments with a neutral 2% NaF solution. For minimising the risk of artefacts, samples were inspected without pre-treatment as fresh, naturally wet specimens by complementary techniques: variable pressure electron microscopy (VP-SEM) and confocal laser scanning microscopy (CLSM). VP-SEM provided information on the surface morphology, whereas CLSM allowed non-destructive visualisation of subsurface areas. Neutral NaF solutions induced globular precipitates on the enamel surfaces. If the globules formed may be described as "calcium fluoride like material", the additional information of this experiment is that, after intera…
Orthogonal functionalisation of upconverting NaYF4 nanocrystals.
2013
A simple and straightforward method for the orthogonal functionalisation of upconverting NaYF4 nanocrystals (UCNCs)-doped withYb(3+) and Er(3+)-based on N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide (EDC/NHS) selective reactions between two dyes and two different reactive groups present at the periphery of the upconverting nanocrystals is reported. Organic-soluble UCNCs of 10 and 50 nm in size are encapsulated efficiently in a 1:1 mixture of two commercial 3000 Da poly(ethylene glycol) derivatives with two different reactive groups (amino and carboxylic groups). The water-dispersible UCNCs are non-cytotoxic, stable in the physiological environment, and present free ami…
Agua de bebida en el lactante
2004
Se revisan tipos de aguas de consumo público y aguas de bebida envasadas. Se realizan recomendaciones sobre las características que debe reunir el agua destinada al lactante. Para la reconstitución correcta de todas las fórmulas de inicio comercializadas en España, el contenido en sodio debe ser menor de 25 mg/l. El agua de consumo público debe hervirse un máximo de 1 min (a nivel del mar) para evitar la excesiva concentración de sales. No precisa de ebullición el agua de bebida envasada. El nivel de flúor debe ser menor de 0,3 mg/l en el primer año de vida para evitar fluorosis. La concentración de nitratos en agua debe ser menor de 25 mg/l para evitar metahemoglobinemia. Aguas con una con…
Green phosphorescence and electroluminescence of sulfur pentafluoride-functionalized cationic iridium(III) complexes
2015
EZ-C acknowledges the University of St Andrews for financial support. We report four cationic iridium(III) complexes [Ir(C^N)2(dtBubpy)](PF6) that have sulfurpentafluoride-modified 1-phenylpyrazole and 2-phenylpyridine cyclometalating (C^N) ligands (dtBubpy = 4,4'-di-tert-butyl-2,2'-bipyridyl). Three of the complexes were characterized by single-crystal X-ray structure analysis. In cyclic voltammetry, the complexes undergo reversible oxidation of iridium(III) and irreversible reduction of the SF5 group. They emit bright green phosphorescence in acetonitrile solution and in thin films at room temperature, with emission maxima between 482–519 nm and photoluminescence quantum yields of up to 7…
Structure and Matrix Isolation Infrared Spectrum of Formyl Fluoride Dimer: Blue-Shift of the C−H Stretching Frequency
2006
Infrared spectroscopy (IR) of formyl fluoride (HCOF) dimer is studied in low-temperature argon and krypton matrixes. New IR absorptions, ca. 17 cm(-1) blue shifted from the monomer C-H stretching fundamental, are assigned to the HCOF dimer. The MP2/6-311++G calculations were utilized to define structures and harmonic frequencies of various HCOF dimers. Among the four optimized structures, the dimer having two C-H...O hydrogen bonds possesses strongest intermolecular bonding. The calculated harmonic frequencies of this dimer structure are shifted from the monomer similarly as observed in the experiment. Thus, we suggest that the experimentally observed blue shifted C-H bands belong to the di…
Determination of the irradiation field at the research reactor TRIGA Mainz for BNCT.
2009
For the application of the BNCT for the excorporal treatment of organs at the TRIGA Mainz, the basic characteristics of the radiation field in the thermal column as beam geometry, neutron and gamma ray energies, angular distributions, neutron flux, as well as absorbed gamma and neutron doses must be determined in a reproducible way. To determine the mixed irradiation field thermoluminescence detectors (TLD) made of CaF(2):Tm with a newly developed energy-compensation filter system and LiF:Mg,Ti materials with different (6)Li concentrations and different thicknesses as well as thin gold foils were used.
Trap Spectroscopy by the Glow Rate Technique using Bleaching of Colour Centres
2002
An application of the glow rate technique (GRT) for analysis of the parameters of thermostimulated decay of colour centres is presented using the data on the decay of radiation defects in LiBaF 3 :Fe crystals created by X rays at 300 K. The GRT offers a procedure for evaluation of the mean activation energy as a function of temperature in the case of arbitrary thermostimulated relaxation kinetics represented by the trap distribution function. The experimental procedure involves at least two subsequent measurements of thermostimulated decay kinetics at different heating rates. It is shown that the decay of the F type centres is governed by interaction of mobile anion vacancies with F A and F…