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1.
J Biomed Mater Res B Appl Biomater ; 106(4): 1421-1430, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28636267

RESUMEN

The purpose of this work was to investigate the effect of strontium partial replacement for calcium on the crystallization behavior, microstructure and solubility of fluorapatite glass-ceramics. Four glass compositions were prepared with increasing amounts of strontium partially replacing calcium. The crystallization behavior was analyzed by differential scanning calorimetry and X-ray diffraction (XRD). The microstructure was investigated by scanning electron microscopy. The chemical solubility was quantified according to ISO standard 10993-14. The amount of strontium released in solution after incubation in TRIS-HCl or citric acid buffer was measured by atomic absorption spectroscopy. XRD analyses revealed that partially substituted strontium-fluorapatite and strontium-åkermanite crystallized after strontium additions. The lattice cell volume of both phases increased linearly with the amount of strontium in the composition. Strontium additions led to a reduction in crystal size and an increase in crystal number density. The chemical solubility and amount of strontium released in solution increased linearly with the amount of strontium present in the composition in both TRIS-HCl and citric acid buffers. Total amounts of strontium released reached a maximum of 547 ± 80 ppm in TRIS-HCl and 1252 ± 290 ppm in citric acid buffer for the glass composition with the highest amount of strontium. For all strontium-containing compositions, the amount released in TRIS-HCl continued to increase between 70 and 120 h, indicating sustained release rather than burst release. © 2017 Wiley Periodicals, Inc. J Biomater Res Part B: 106B: 1421-1430, 2018.


Asunto(s)
Apatitas/química , Cerámica/química , Estroncio , Cristalización , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Microscopía Electrónica de Rastreo , Solubilidad , Estroncio/química , Estroncio/farmacología , Difracción de Rayos X
2.
J Dairy Sci ; 99(1): 183-93, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26519972

RESUMEN

Preference mapping studies with cottage cheese have demonstrated that cottage cheese liking is influenced by flavor, texture, curd size, and dressing content. However, extrinsic factors such as package, label claims, and brand name may also influence liking and have not been studied. The objective of this study was to evaluate the role of package attributes and brand on the liking of cottage cheese. A conjoint survey with Kano analysis (n=460) was conducted to explore the effect of extrinsic attributes (brand, label claim, milkfat content, and price) on liking. Following the survey, 150 consumers evaluated intrinsic attributes of 7 cottage cheeses with and without brand information in a 2-d crossover design. Results were evaluated by 2-way ANOVA and multivariate analyses. Milkfat content and price had the highest influence on liking by conjoint analysis. Cottage cheese with 2% milkfat and a low price was preferred. Specific label claims such as "excellent source of calcium (>10%)" were more attractive to consumers than "low sodium" or "extra creamy." Branding influenced overall liking and purchase intent for cottage cheeses to differing degrees. For national brands, acceptance scores were enhanced in the presence of the brand. An all-natural claim was more appealing than organic by conjoint analysis and this result was also confirmed with consumer acceptance testing. Findings from this study can help manufacturers, as well as food marketers, better target their products and brands with attributes that drive consumer choice.


Asunto(s)
Queso , Comportamiento del Consumidor , Gusto , Adulto , Queso/análisis , Queso/economía , Conducta de Elección , Análisis por Conglomerados , Comportamiento del Consumidor/economía , Grasas de la Dieta/análisis , Femenino , Embalaje de Alimentos/economía , Preferencias Alimentarias , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante
3.
Neuroimage ; 53(1): 268-74, 2010 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-20547226

RESUMEN

Grapheme-color synesthesia is a neurological phenomenon in which letters and numbers (graphemes) consistently evoke particular colors (e.g. A may be experienced as red). The cross-activation theory proposes that synesthesia arises as a result of cross-activation between posterior temporal grapheme areas (PTGA) and color processing area V4, while the disinhibited feedback theory proposes that synesthesia arises from disinhibition of pre-existing feedback connections. Here we used magnetoencephalography (MEG) to test whether V4 and PTGA activate nearly simultaneously, as predicted by the cross-activation theory, or whether V4 activation occurs only after the initial stages of grapheme processing, as predicted by the disinhibited feedback theory. Using our high-resolution MEG source imaging technique (VESTAL), PTGA and V4 regions of interest (ROIs) were separately defined, and activity in response to the presentation of achromatic graphemes was measured. Activation levels in PTGA did not significantly differ between synesthetes and controls (suggesting similar grapheme processing mechanisms), whereas activation in V4 was significantly greater in synesthetes. In synesthetes, PTGA activation exceeded baseline levels beginning 105-109ms, and V4 activation did so 5ms later, suggesting nearly simultaneous activation of these areas. Results are discussed in the context of an updated version of the cross-activation model, the cascaded cross-tuning model of grapheme-color synesthesia.


Asunto(s)
Percepción de Color , Potenciales Evocados Visuales , Magnetoencefalografía/métodos , Trastornos de la Visión/fisiopatología , Corteza Visual/fisiopatología , Percepción Visual , Adulto , Femenino , Humanos , Masculino , Adulto Joven
4.
Neuroscience ; 143(3): 805-14, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16996695

RESUMEN

This study examines the interaction between two types of synesthesia: ordinal linguistic personification (OLP; the involuntary association of animate qualities such as gender/personality to linguistic units such as letters/numbers/days) and grapheme-color synesthesia (the involuntary association of colors to letters and/or numbers). By examining both variants in the same individual we aim to: (a) show that features of different synesthetic variants interact in cognitive tasks, (b) provide a cognitive model of this interaction, and (c) constrain models of the underlying neurological roots of this connectivity. Studies have shown inhibition in Stroop-type tasks for naming font colors that clash with synesthetic colors (e.g. slower naming of green font for synesthetically red letters). We show that Stroop-type slow-down occurs only when incongruent colors come from other letters with matching (but not mis-matching) gender (experiment 2). We also measure the speed of OLP gender judgments (e.g. a=female; experiment 1) and show that response times are slowed by incongruent colors from other letters with mis-matching (but not matching) genders. Our studies suggest that synesthetic variants interact and that their concurrents can become implicitly connected without mediation from inducing stimuli. We interpret these findings in light of recent developmental data showing protracted heterochronous neuronal development in humans, which continues through adolescence in parietal, frontal and perisylvian areas.


Asunto(s)
Asociación , Cognición/fisiología , Formación de Concepto/fisiología , Modelos Psicológicos , Adulto , Análisis de Varianza , Percepción de Color/fisiología , Femenino , Humanos , Reconocimiento Visual de Modelos/fisiología , Estimulación Luminosa/métodos , Tiempo de Reacción/fisiología
5.
Proc Biol Sci ; 268(1470): 979-83, 2001 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-11370973

RESUMEN

We studied two otherwise normal, synaesthetic subjects who 'saw' a specific colour every time they saw a specific number or letter. We conducted four experiments in order to show that this was a genuine perceptual experience rather than merely a memory association. (i) The synaesthetically induced colours could lead to perceptual grouping, even though the inducing numerals or letters did not. (ii) Synaesthetically induced colours were not experienced if the graphemes were presented peripherally. (iii) Roman numerals were ineffective: the actual number grapheme was required. (iv) If two graphemes were alternated the induced colours were also seen in alternation. However, colours were no longer experienced if the graphemes were alternated at more than 4 Hz. We propose that grapheme colour synaesthesia arises from 'cross-wiring' between the 'colour centre' (area V4 or V8) and the 'number area', both of which lie in the fusiform gyrus. We also suggest a similar explanation for the representation of metaphors in the brain: hence, the higher incidence of synaesthesia among artists and poets.


Asunto(s)
Percepción Auditiva/fisiología , Encéfalo/fisiología , Percepción de Color/fisiología , Percepción de Forma/fisiología , Sensación/fisiología , Mapeo Encefálico , Humanos , Lectura
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