The influence of treatment temperature on the acidity of MWCNT oxidized by HNO3 or a mixture of HNO3/H2SO4

The nature of multi-walled carbon nanotubes (MWCNTs) varies with the change in oxidation conditions. In this work, the effect of treatment temperatures on the acidity of MWCNTs was studied. Oxidation was performed by refluxing the MWCNTs in nitric acid or mixtures of sulfuric acid and nitric acid at different temperatures. After oxidative treatment, a quantitative characterization of o-MWCNTs has been performed using acid-base titrations which show that the number of surface acidic functional groups increased by increasing the treatment temperatures. Energy dispersive X-ray (EDX) measurements show that the oxygen content increased with increasing treatment temperatures. Fourier transform infrared absorption spectroscopy (FTIR) was used for qualitative characterization. It has been demonstrated that the acidity is a function of the type of oxidizing agent used and the treatment temperatures. Due to the importance in attachment strategies and functionalization, this study adds to the global discussion of the possibility of controlling the MWCNTs’ surface chemistry which plays a crucial role in determining its reactivity.     

The impact of long-term botulinum toxin injections on symptom severity in patients with spasmodic dysphonia

Injection of botulinum toxin (BT) into the muscles of the larynx is an effective treatment for the symptoms of spasmodic dysphonia (SD). To date, however, there have been no studies that have used blinded raters to assess the efficacy of BT injections on overall symptom severity in a cohort of SD patients followed over a prolonged period. In this study, 102 subjects with SD were treated with serial BT injections for up to 2 years. Voice recordings were obtained at several time points during treatment and were played to a panel of expert and novice listeners who rated them based on overall symptom severity in a single-blind fashion. Subjects demonstrated significant improvement over baseline at all time points. In addition, patients showed a sustained responsiveness to therapy over time. These results provide support for the efficacy of serial BT injections for SD and suggest that successful treatment may depend, in part, on patients' early recognition of returning symptoms.     

Three-dimensional contrast-enhanced ultrasound of the liver: Experience of 92 cases

Three-dimensional contrast-enhanced ultrasound (3D-CEUS) is a combination of three-dimensional ultrasound (3DUS) and contrast-enhanced ultrasound (CEUS). To evaluate the feasibility of 3D-CEUS in liver imaging, investigate possible influencing factors to its image quality, and evaluate the influence of 3D-CEUS to clinical outcome, low acoustic power (mechanical index, 0.08-0.13) 3D-CEUS was carried out in 102 focal liver lesions in 92 patients by using the LOGIQ 9 ultrasound scanner and a volume transducer (frequency range, 2-5 MHz; focusing ability, 2-25 cm in depth; azimuth aperture 5.9 cm). The lesions were classified into two groups: group 1 (n = 51) for characterization and group 2 (n = 51) for local treatment response evaluation. The factors that influenced the image quality of 3D-CEUS were analyzed. The image quality and usefulness of 3D-CEUS between the two groups were compared by using the χ²-test. The results showed that the lesion diameter, location, and scanning route had no significant influence on the image quality in both groups, whereas interfering factors damaged the image quality in group 1. In group 1, during arterial phase, high image quality was more frequently found in hyperenhanced and hypo- or non-enhanced lesions compared with isoenhanced lesions. In group 2, interfering factor and local treatment response had no obvious influence on the image quality. The visualization rate of high image quality was 94.1% (48/51) in group 2 vs. 72.6% (37/51) in group 1 (P = 0.012). The investigators found that 3D-CEUS improved confidence but made no change in diagnosis in 19 (37.3%) of 51 lesions in group 1, whereas 41 (80.4%) of 51 lesions in group 2 (P = 0.000). 3D-CEUS tends to obtain better image quality and lead to higher diagnostic confidence in the lesions for local treatment response evaluation, and perhaps is more useful in this aspect in future clinical settings.     

Changes in vocal intensity in Parkinson's disease following pallidotomy surgery

The present study was designed to examine changes in vocal intensity following unilateral posteroventral pallidotomy (PVP) in a large sample of speakers with Parkinson's disease (PD) that exhibited a range of hypokinetic dysarthria. Twenty-five persons with PD were recorded using a variety of speech tasks, once prior to and once following PVP. The pre-PVP vocal SPL was subtracted from the post-PVP vocal SPL to derive a relative change in vocal SPL. Mildly dysarthric participants had significantly greater relative increases in vocal SPL following PVP than either moderately or severely dysarthric participants who had reduced vocal SPL following PVP. If future results follow those observed in the present data, mildly dysarthric Parkinson's patients may benefit most from unilateral PVP perhaps due to less overall destruction of the basal ganglia sensorimotor control circuits involved in oral facial functions, thus increasing the chances to observe improvements postsurgery.     

Effect of structural relaxation on Curie temperature and magnetostriction investigated by magnetoelastic waves in metglas

Summary Magnetoelastic wave amplitude, a, was measuredvs. the temperature during thermal cycles in Metglas 2826. When the Curie temperature,T _C, has been reached, theA value vanishes due to the fall of the magnetoelastic coupling in the paramagnetic state. This allows evaluation of theT _c temperature. The latter increases after the iterated thermal treatments while the magnetic anisotropyK _u decreases. Also theA amplitude, measured at room temperature after the subsequent thermal treatments, shows an increasing behaviour. The values ofK _u ,T _c andA approach saturation after the same number of thermal cycles; this suggests that the structural relaxation produced by annealing is the microscopic mechanism governing all the three physical quantities. In particular we explain the connection betweenK _u andA by means of the longitudinal magnetostriction.

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Riassunto L'ampiezza delle onde magnetoelastiche,A, è stata misurata in funzione della temperatura eseguendo cicli termici nel Metglas 2826. Raggiunta la temperatura di Curie,T _C l'ampiezzaA si annulla a causa della transizione dell'accoppiamento magnetoelastico nello stato paramagnetico. Ciò ci mette in grado di misurare la temperaturaT _C; quest'ultima aumenta in seguito ai ripetuti trattamenti termici mentre l'anisotropia magneticaK _u diminuisce. Anche l'ampiezzaA, misurata a temperatura ambiente dopo i trattamenti termici, mostra un andamento crescente. I valori diK _u,T _c eA tendono alla saturazione dopo lo stesso numero di cicli termici; ciò suggerisce che il rilassamento strutturale prodotto dalla ricottura è il meccanismo microscopico che regola le tre grandezze fisiche menzionate. In particolare noi mostriamo cheK _u eA sono legati dalla magnetostrizione longitudinale.

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Резюме Измеряется зависимость амплитуды магнитноупругой волны,A, от температуры в течение температурных циклов в металлическом стекле 2826. При достижении температуры Кюри,T _c, величинаA обращается в нуль из-за уменьшения магнитноупругой связи в парамагнитном состоянии. Это позволяет оценить темпаратуру Кюри,T _c. Температура Кюри увеличивается после повторных температурных обработок, тогда как магнитная анизотропияK _u уменьшается. Также отмечается увеличение амплитудыA, измеренной при комнатной температуре после последовательных температурных обработок. ВеличиныK _u,T _c иA приближаются к насьщению после одинакового числа температурных циклов. Это результат предполагает, что структурная релаксация, обусловленная отжигом, представляет микроскопический механизм, определяющий все три физические величины. В частности, мы объсняем связь междуK _u иA с помощью продольной магнитострикции.

     

The secondary structure of heated whey protein and its hydrolysates antigenicity

Fourier transform infrared spectroscopy(FTIR) and circular dichroism(CD) were used to investigate the conformational changes of heated whey protein(WP) and the corresponding changes in the hydrolysates immunoreactivity were determined by competitive enzyme-linked immunosorbent assay(ELISA).Results showed that the contents of α-helix and β-sheet of WP did not decrease much under mild heating conditions and the antigenicity was relatively high;when the heating intensity increased(70 ℃ for 25 min or 75 ℃ for 2...     

Behavioral therapy for spasmodic dysphonia

This paper presents a general schema for classifying treatment approaches for both functional and organic voice disorders. It's use is illustrated by a review of treatments for Spasmodic Dysphonia. Most behavioral approaches have been found to be unsuccessful except for mild cases. Inhalation speech as a compensatory technique has been reported as somewhat successful for those mild/moderate cases for whom medical/surgical treatment has not been available. The fact that organic treatment levels have been more successful in the treatment of Spasmodic Dysphonia may lend support to an organic etiology     

Effects of High-Pressure Treatment on the Sensory Quality of White Grape Juice

The effects of high-pressure treatment on the colour (objective measurement) and sensory characteristics of white grape juice were studied during storage at 4 °C for 60 days. Grape juice was subjected to three different treatments: 400 or 500 MPa at 2 u °C, and 400 MPa at 40 °C during 10 min. Untreated juice was used as control. Colour parameters (CIE L * a * b *), hue angle (tan m 1 b */ a *), chroma {( a * 2 + b * 2 ) 1/2 }, luminosity Q *{(10 2 log( L *) + 100} and saturation S *( C */ L *) were measured. Juices were evaluated for sweetness, acidity, off-flavour and aroma. High-pressure treatments did not affect the colour parameters of juice, and similar sensory characteristics were observed in both control and treated samples on the first day. The colour and sensory characteristics of pressure-treated samples remained more stable than those of the control juice during 60 days of storage. The control juice was slightly fermented developing some changes in flavour and colour.     

Influence of different SiC surface treatments performed prior to Ni ohmic contacts formation

This work is dealing with the influence of surface treatment on ohmic contacts to hexagonal N-type SiC with medium doping level. The contact materials were Ni and Ni₂Si. The structures had to be annealed at high temperatures in order to reach ohmic behavior. A number of surface treatment methods were tested: wet cleaning, plasma etching, intentional oxidation with etching, H₂ annealing and their combinations. After some types of cleaning, the SiC surface was immediately analysed using the XPS method. The results of the analyses showed that the composition of the surface was not much influenced by these treatments. At lower annealing temperatures (approx. up to 850 °C) the prepared contacts showed Schottky behavior with large scatter of parameters. After annealing at approx. 960 °C, where the onset of ohmic behavior is expected, the structures were truly ohmic and of good parameters. Cleaning methods had just a negligible influence on the electrical parameters of the ohmic contacts. An explanation for these observed facts is suggested: Although - already on the basis of the XPS results - we could speak about a negligible influence of the cleaning onto the contact parameters, there might come across also other mechanisms coming from interaction of contact materials with SiC, which caused similar behavior of ohmic contacts on differently treated surfaces.