Phono-articulatory variations of women in reproductive age and postmenopausal

Human verbal expression requires coordinated interaction among cortical, neuromuscular, and peripheral events. It is affected by hormonal factors and shows different characteristics in reproductive age and postmenopausal women. The present study compared phono-articulatory characteristics between women in reproductive age postmenopausal. Acoustic variations in fundamental frequency, voice sustenance, formants, vocal intensity, and verbal diadochokinesis were measured. Forty-five women in reproductive age with regular menstrual cycles and taking no hormonal contraceptives and 45 postmenopausal women receiving no hormonal replacement therapy for at least 3 years were interviewed, and their verbal productions were tape-recorded. Acoustic analyses were performed using the Kay Elemetrics Motor Speech Profile (Lincoln Park, NJ). Student t test was employed to compare data between the two groups when they presented normal distribution and Mann-Whitney test when they were asymmetrical. Results showed a greater variability in vocal sustenance, less variation in formants, and verbal diadochokinesis in postmenopausal women. There were no significant variations in fundamental frequency and vocal intensity. These results emphasize the need of a multidisciplinary integrated research, when assessing phono-articulatory processes after the menopause. A better understanding in this field will make it possible to elaborate strategies to offer a better life quality for postmenopausal women.     

Voltammetric determination of chlorothalonil and its respective reduction mechanism studied by density functional theory

Journal of Solid State Electrochemistry - A simple, fast, and direct electroanalytical method has been developed for the pesticide chlorothalonil determination using a boron-doped diamond electrode...     

Ozonolysis of methyl, amino and nitro substituted ethenes: A semi-empirical molecular orbital study

The three-step ozonolysis reaction is studied for a number of methyl, amino and nitro substituted ethenes (classified as symmetrically, asymmetrically and cis/trans substituted) using the PM3 SCF-MO method. Substituent effects are predicted to generally yield the order NH₂ > Me > NO₂ for the ability to enhance facility of ozonolysis, in line with the electrophilic nature of ozone. Geometry and conformation allow for a variety of different pathways, and the lowest energy pathway is predicted for each case, with consequences for identity of the intermediates preferentially involved. Greater stability of the trans isomer of the carbonyl oxide intermediate is the main factor for its preferred involvement in the second step of the reaction. For the cis/trans substituted ethenes, the major product (the secondary ozonide) is predicted as being the cis ozonide and the trans ozonide for the cis and the trans substituted ethenes, respectively.     

Speciation of mercury compounds in waste water by microcolumn liquid chromatography using a preconcentration column with cold-vapour atomic absorption spectrometric detection

A microcolumn liquid chromatographic method with cold-vapour atomic absorption spectrometric detection was developed for the speciation of mercury compounds in waste water. The sample solution containing mercury at the 4-ng level was injected onto a preconcentration column (27 mn × 0.51 mm i.d.) packed with Develosil-ODS (30 μm) and eluted with cysteine-acetic acid through a separation column (125 mm × 0.5 mm i.d.) packed with STR-ODS-H (5 μm). After oxidation, tin(II) chloride in sodium hydroxide solution was used to reduce mercury compounds to mercury. The generated mercury vapour was swept from a gas-liquid separator by argon into the detector cell and monitored at 253.7 nm. Mercury(II) chloride, methylmercury chloride and ethylmercury chloride, were well resolved and the determination was completed in less than 16 min. The method was successfully applied to the speciation of mercury compounds in waste water.     

Chemical and Skincare Property Characterization of the Main Cocoa Byproducts: Extraction Optimization by RSM Approach for Development of Sustainable Ingredients

Methylxanthines and polyphenols from cocoa byproducts should be considered for their application in the development of functional ingredients for food, cosmetic and pharmaceutical formulations. Different cocoa byproducts were analyzed for their chemical contents, and skincare properties were measured by antioxidant assays and anti-skin aging activity. Musty cocoa beans (MC) and second-quality cocoa beans (SQ) extracts showed the highest polyphenol contents and antioxidant capacities. In the collagenase and elastase inhibition study, the highest effect was observed for the SQ extract with 86 inhibition and 36% inhibition, respectively. Among cocoa byproducts, the contents of catechin and epicatechin were higher in the SQ extract, with 18.15 mg/100 g of sample and 229.8 mg/100 g of sample, respectively. Cocoa bean shells (BS) constitute the main byproduct due to their methylxanthine content (1085 mg of theobromine and 267 mg of caffeine/100 g of sample). Using BS, various influencing factors in the extraction process were investigated by response surface methodology (RSM), before scaling up separations. The extraction process developed under optimized conditions allows us to obtain almost 2 g/min and 0.2 g/min of total methylxanthines and epicatechin, respectively. In this way, this work contributes to the sustainability and valorization of the cocoa production chain.     

Thermoluminescence glow curves analysis of pure and CeO2-doped Li2O-Al2O3-SiO2 glass ceramics

A comparative study of the thermoluminescence (TL) emission between beta-irradiated lithium aluminosilicates, Li₂O-Al₂O₃-SiO₂ (LAS), and beta-irradiated CeO₂-doped lithium aluminosilicates, Li₂O-Al₂O₃-SiO₂-CeO₂ (LAS:Ce), grown by sol-gel technique and preannealed at 1250 °C is presented. It is found that doping reinforces the result of preannealing the sample; the incorporation of CeO₂ at low concentrations shifts the TL curves towards higher temperatures and increases the total intensity with respect to samples without the dopant. This behavior, together with the fact that CeO₂ is a good densification agent, suggests the possibility of using CeO₂ to improve the technological properties of LAS. Deconvolution analysis of the thermoluminescence glow curves of doped materials under general order kinetics shows that the relevant temperatures at which the component signals appear are virtually the same as for pure samples. This suggests that CeO₂ does not introduce new types of traps, but only changes the population and distribution of impurities responsible for the TL in the original matrix of LAS. Finally, the kinetic parameters for the deconvoluted curves are reported. They corroborate that changes in CeO₂ concentration only vary the depth and distribution of the same kind of original traps.     

Design of small volume HX and triple-resonance probes for improved limits of detection in protein NMR experiments

Three- and four-frequency nuclear magnetic-resonance probes have been designed for the study of small amounts of protein. Both "HX" (1H, X, and 2H channels) and "triple-resonance" (1H, 15N, 13C, and 2H) probes were implemented using a single transmit/receive coil and multiple-frequency impedance matching circuits. The coil used was a six-turn solenoid with an observe volume of 15 microl. A variable pitch design was used to improve the B1 homogeneity of the coil. Two-dimensional HSQC spectra of approximately 1mM single labeled 15N- and double labeled 15N/13C-proteins were acquired in experimental times of approximately 2h. Triple-resonance capability of the small-volume triple-resonance probe was demonstrated by acquiring three-dimensional HNCO spectra from the same protein samples. In addition to enabling very small quantities of protein to be used, the extremely short pulse widths (1H = 4, 15N = 4, and 13C = 2 micros) of this particular design result in low power decoupling and wide-bandwidth coverage, an important factor for the ever-higher operating frequencies used for protein NMR studies.     

Synthesis and characterization of palladium(II) and platinum(II) metal complexes with iminophosphine ligands: X-ray crystal structures of platinum(II) complexes and use of palladium(II) complexes as pre-catalysts in Heck and Suzuki cross-coupling reactions

The reactions of N-(2(diphenylphosphino) benzylidene) (phenyl) methanamine, Ph₂PPhNHCH₂-C₅H₄N, 1 and N-(2-(diphenylphosphino) (benzylidene) (thiophen-2-yl) methanamine, Ph₂PPhNHCH₂-C₄H₃S, 2 with MCl₂(cod) and MCl(cod)Me (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield the new complexes [M(Ph₂PPhNHCH₂-C₅H₄N)Cl₂], M = Pd1a, Pt1b, [M(Ph₂PPhNHCH₂-C₅H₄N)ClMe], M = Pd1c, Pt 1d, [M(Ph₂PPhNHCH₂-C₄H₃S)Cl₂], M = Pd2a, Pt 2b, and [M(Ph₂PPhNHCH₂-C₄H₃S)ClMe], M = Pd2c, Pt 2d, respectively. The new compounds were isolated as analytically pure crystalline solids and characterized by ³¹P-, ¹H-NMR, IR spectroscopy, electro spray ionization-mass spectrometry (ESI-MS) and elemental analysis. The representative solid-state molecular structures of the platinum complexes 1b and 2b were determined using single crystal X-ray diffraction analysis and revealed that the complexes exhibit a slightly distorted square-planar geometry. Furthermore, the palladium complexes were tested as potential catalysts in the Heck and Suzuki cross-coupling reactions.