Towards the Automatic Study of the Vocal Tract From Magnetic Resonance Images

Over the last few decades, researchers have been investigating the mechanisms involved in speech production. Image analysis can be a valuable aid in the understanding of the morphology of the vocal tract. The application of magnetic resonance imaging to study these mechanisms has been proven to be reliable and safe. We have applied deformable models in magnetic resonance images to conduct an automatic study of the vocal tract; mainly, to evaluate the shape of the vocal tract in the articulation of some European Portuguese sounds, and then to successfully automatically segment the vocal tract's shape in new images. Thus, a point distribution model has been built from a set of magnetic resonance images acquired during artificially sustained articulations of 21 sounds, which successfully extracts the main characteristics of the movements of the vocal tract. The combination of that statistical shape model with the gray levels of its points is subsequently used to build active shape models and active appearance models. Those models have then been used to segment the modeled vocal tract into new images in a successful and automatic manner. The computational models have thus been revealed to be useful for the specific area of speech simulation and rehabilitation, namely to simulate and recognize the compensatory movements of the articulators during speech production.     

Voice Characteristics in Adults With Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous disorder caused by mutations in the NF1 gene, which is located at the long arm of chromosome 17. Major characteristics include multiple café-au-lait spots and neurofibromas. Voice abnormalities have been reported to occur in this patient group. However, most studies relied on subjective measurements only. The present study reports the results of an objective voice assessment based on a multiparameter approach in 22 adults with NF1. Aerodynamic measurements, voice range profiles, acoustic voice quality and intonation measurements, and dysphonia severity indices were obtained and compared with data from a control group, consisting of 22 healthy adults. It was found that NF1 patients show a poorer overall voice quality compared with controls. Particularly, a reduction of vital capacity and limitations in laryngeal possibilities with respect to frequency and intensity were observed in the NF1 group.     

Application of a liquid chromatography tandem mass spectrometry method for the simultaneous detection of seven allergenic foods in flour and bread and comparison of the method with commercially available ELISA test kits

To protect the allergic consumer, analytical methods need to be capable of detecting allergens in finished products that typically contain multiple allergens. An LC/MS/MS method for simultaneous detection of seven allergens was developed and compared with commercially available ELISA kits. The detection capabilities of this novel method were demonstrated by analyzing incurred material containing milk, egg, soy, peanut, hazelnut, walnut, and almond. Bread was chosen as a model matrix. To assess the influence of baking on the method's performance, analysis was done before and after baking. The same samples were analyzed with ELISA test kits from ELISA Systems, Morinaga, Neogen, and r-Biopharm. Peanut, hazelnut, walnut, and almond could be detected with both ELISA and LC/MS/MS regardless of whether the product was baked or not. LC/MS/MS clearly showed superior detection of milk in processed matrixes compared to ELISA, which exhibited significantly lower sensitivities when analyzing the baked products. Similar results were obtained when analyzing egg; however, one kit was capable of detecting egg in the processed samples as well.     

Photophysical properties of charged cyclometalated Ir(III) complexes: a joint theoretical and experimental study

The photophysical properties of a series of charged biscyclometalated [Ir(ppy)(2)(N^N)](1+) complexes, where ppyH is 2-phenylpyridine and N^N is 2,2'-bipyridine (bpy), 6-phenyl-2,2'-bipyridine (pbpy), and 6,6'-diphenyl-2,2'-bipyridine (dpbpy) for complexes 1, 2, and 3, respectively, have been investigated in detail. The photoluminescence performance in solution decreases from 1 to 3 upon attachment of phenyl groups to the ancillary ligand. The absorption spectra recorded over time suggest that complex 3 is less stable compared to complexes 1 and 2 likely due to a nucleophilic-assisted ancillary ligand-exchange reaction. To clarify this behavior, the temperature dependence of the experimental intrinsic deactivation rate constant, k(in) = 1/τ, has been investigated from 77 K to room temperature. Temperature-dependent studies show that nonemitting metal-centered (MC) states are accessible at room temperature for complex 3. The experimental results are interpreted with the help of theoretical calculations performed within the density functional theory (DFT) approach. Calculations suggest that attachment of a phenyl group to the ancillary ligand (2) promotes the temperature-independent deactivation pathways, whereas attachment of a second phenyl group (3) also makes the temperature-dependent ones accessible through population of nonradiative (3)MC excited states.     

Comparative study of 17��-estradiol removal from aqueous solutions using pine bark and almond shell as adsorbents

We have investigated the adsorption of the endocrine disruptor 17?-estradiol (E2) on pine bark and almond shell. These traditional Portuguese agro-forestry by-products were milled, sieved into different particle size fractions and submitted to two different kinds of treatment. Adsorption experiments were conducted in batch system at room temperature and at pH 4.75 and 6.80, respectively, for pine bark and almond shell. E2 was more effectively adsorbed on 100 to 150???m particles of both sorbents. Pine bark washed with hot water and pine bark treated with formaldehyde showed higher percentage of adsorption than any other material tested at doses of 5.0?g?L^?1. The adsorption was of comparable efficiency in case of almond shells at doses of around 20?g?L^?1. In this case, the percentage of adsorption was found to be 88 and 90% for the sorbents treated with formaldehyde or washed with hot water. The adsorption isotherms were found to fit a Freundlich equation, with correlation coefficients (R²) between 0.904 and 0.998. The sorption coefficient (K_F) ranged from 0.03 to 29.9 (mg^1?1/n L^1/n g^?1). The differences observed among the adsorption capacities are discussed in terms of physico-chemical characterization of the materials.

Evaluation of a multiarray system for pharmaceutical analysis by microemulsion electrokinetic chromatography

A multiplexed capillary electrophoresis (CE) system equipped with 96 channels was evaluated for high-throughput screening in drug discovery by microemulsion electrokinetic chromatography (MEEKC). Method transfer from a single channel to a multichannel CE system is described. Loss of efficiency and reduced migration times could be elucidated to the poor efficacy in Joule heat dissipation by forced air cooling in the multiarray system compared to liquid cooling in the single channel instrument. On the other hand, only 48 channels could actually be used because of the maximum total current of 3 mA. Precision data remained below 8% and 9% for migration times and peak areas, respectively. Some UV-detector cross-talk interference between neighboring capillary channels was noted. Impurities at 0.5% compared to the main peak (100%) could be detected with the multiplexed system which is 10 times lower compared to the single capillary system. Higher efficiency and improved figures of merit (absolute sensitivity and no cross-talk interferences) were obtained by using an array of only 24 capillaries.     

Incorporation of a flame retardancy enhancing phosphorus-containing diol into poly(butylene terephthalate) via solid state polycondensation: A comparative study

The phosphorus-containing aliphatic-aromatic diol 2-[4-(2-hydroxy-ethoxy)-3-(10-oxo-10-H9-oxa-10-λ5-phospha-phenanthrene-10-yl)-phenoxy]-ethanol, a potential flame retardant, was incorporated into poly(butylene terephthalate) (PBT) by solid state polycondensation. Thus, polymers with various ratios of PBT/DOPO-diol and number-average molar masses up to 57,000 g mol⁻¹ could be prepared. Their molar masses were higher than those of copolyesters with comparable composition obtained by direct melt polycondensation. Structures and properties of copolyesters produced by both methods were not significantly different after melt processing. Their thermal properties and combustion behaviour were investigated by means of DSC, TGA, and pyrolysis combustion flow calorimetry. Combustion studies revealed high char yields, very low heat release capacities and high limiting oxygen index (LOI) at rather low P-contents, indicative of better flame-retardancy properties.     

Electrochemistry/liquid chromatography/mass spectrometry as a tool in metabolism studies

Electrochemistry/liquid chromatography/mass spectrometry is a powerful complementary tool for the simulation of the oxidative metabolism of drugs and other xenobiotics.     

Structural modification of nanocrystalline ceria by ion beams

Exceptional size-dependent electronic-ionic conductivity of nanostructured ceria can significantly alter materials properties in chemical, physical, electronic and optical applications. Using energetic ions, we have demonstrated effective modification of interface volume and grain size in nanocrystalline ceria from a few nm up to ～25 nm, which is the critical region for controlling size-dependent material property. The grain size increases and follows an exponential law as a function of ion fluence that increases with temperature, while the cubic phase is stable under the irradiation. The unique self-healing response of radiation damage at grain boundaries is utilized to control the grain size at the nanoscale. Structural modification by energetic ions is proposed to achieve desirable electronic-ionic conductivity.