Aerodynamic Analysis Of Voice In Persons With Laryngopharyngeal Reflux

Objectives of the study: The individuals with laryngopharyngeal reflux are prone for aspiration of refluxed contents and so there is a need for aerodynamic evaluation in these individuals. Hence, the present study investigated the aerodynamic characteristics in individuals with Laryngopharyngeal reflux. Study design: Prospective control group design. Method: Thirty laryngopharyngeal reflux subjects and 30 normal subjects participated in the study. Aerodynamic parameters such as vital capacity, mean air flow rate, maximum phonation duration and phonation quotient were measured using Aero Phone Instrument ((Model 6800). Independent t test was employed for statistical inference. Results: The results revealed that the vital capacity and maximum phonation duration values were lower for laryngopharyngeal reflux subjects when compared to normal controls. No significant differences were observed for mean air flow rate and phonation quotient. Conclusions: The results revealed that the laryngopharyngeal reflux individuals showed significant deviations in aerodynamic parameters when compared to normal individuals. Thus study confirms aerodynamic abnormalities in laryngopharyngeal reflux subject

Charge order suppression and antiferromagnetic to ferromagnetic switch over in Pr_0.5Ca_0.5MnO_3 nanowires

We have prepared crystalline nanowires (diameter ~ 50 nm, length ~ a few microns) of the charge ordering manganite Pr_0.5Ca_0.5Mn_O3 using a low reaction temperature hydrothermal method and characterized them using X-ray diffraction, transmission electron microscopy, SQUID magnetometry and electron magnetic resonance measurements. While the bulk sample shows a charge ordering transition at 245 K and an antiferromagnetic transition at 175 K, SQUID magnetometry and electron magnetic resonance experiments reveal that in the nanowires phase, a ferromagnetic transition occurs at ~ 105 K. Further, the antiferromagnetic transition disappears and the charge ordering transition is suppressed. This result is particularly significant since the charge order in Pr_0.5Ca_0.5MnO_3 is known to be very robust, magnetic fields as high as 27 T being needed to melt it.Comment: 12 pages including 4 figures. submitted to Applied Physics Letter