Purpose: To evaluate the immediate effect of the incentive spirometer on acoustic measures, aerodynamic measures and on the auditory-perceptual assessment of vocal quality in vocally healthy women.
Methods: This is an experimental intra-subject comparison study with the participation of 22 women without vocal complaints. Acoustic measures, aerodynamic measures and auditory-perceptual assessment of vocal quality were obtained before and immediately after using the incentive spirometer by the participants.
The development of high intensity petawatt lasers has created new possibilities for ion acceleration and nuclear fusion using solid targets. In such laser-matter interaction, multiple ion species are accelerated with broad spectra up to hundreds of MeV. To measure ion yields and for species identification, CR-39 solid-state nuclear track detectors are frequently used.
View Article and Find Full Text PDFObjective: Visual-perceptive assessment of glottic characteristics of vocal nodules by means of high-speed videoendoscopy.
Methods: Descriptive observational research with convenience sampling of five laryngeal videos of women with an average age of 25 years. The diagnosis of vocal nodules was defined by two otolaryngologists, with 100% intra-rater agreement and 53.
Background: Scapulothoracic orientation, especially scapular internal rotation (SIR) may influence range of motion in reverse total shoulder arthroplasty (RTSA) and is subjected to body posture. Clinical measurements of SIR rely on apical bony landmarks, which depend on changes in scapulothoracic orientation, while radiographic measurements are often limited by the restricted field of view (FOV) in CT scans. Therefore, the goal of this study was (1) to determine whether the use of CT scans with a limited FOV to measure SIR is reliable and (2) if a clinical measurement could be a valuable alternative.
View Article and Find Full Text PDFObjectives: Early identification of vocal fold leukoplakia (VFL), which has a risk of progressing to malignant transformation, remains a controversial topic. The identification of biological markers for diagnosing these lesions would lead to a more effective treatment. We aimed to analyze the immunoexpression of cathepsin B and E-cadherin in VFL and correlate it with clinical and epidemiological data and disease prognosis.
View Article and Find Full Text PDFWe present a regime where an ultraintense laser pulse interacting with a foil target results in high γ-photon conversion efficiency, obtained via three-dimensional quantum-electrodynamics particle-in-cell simulations. A single-cycle laser pulse is used under the tight-focusing condition for obtaining the λ^{3} regime. The simulations employ a radially polarized laser as it results in higher γ-photon conversion efficiency compared to both azimuthal and linear polarizations.
View Article and Find Full Text PDFIn an experiment performed with a high-intensity and high-energy laser system, α-particle production in proton-boron reaction by using a laser-driven proton beam was measured. α particles were observed from the front and also from the rear side, even after a 2-mm-thick boron target. The data obtained in this experiment have been analyzed using a sequence of numerical simulations.
View Article and Find Full Text PDFObjective: The aim of the present study was to investigate hyaluronic acid (HA) concentrations in vocal folds among patients with Reinke's edema.
Study Design: Prospective and experimental study.
Setting: Single tertiary center.
Introduction: Combining mechanical vibration stimulation with resistance training to improve neuromuscular performance is a method that has gained popularity in the field of sports sciences.
Purpose: To evaluate the immediate and mid-term effects of mechanical vibration stimulation (G-Life NL3000) of the larynx associated to vocal exercises.
Method: Fourteen professional voice users divided into: Experimental Group - Seven participants who performed a 20-minute exercise protocol with humming applying mechanical vibration stimulation (G-Life NL3000) of the larynx once a day for 30 days; Control Group - Seven participants who performed only the 20-minute exercise protocol with humming.
Using an analytical model and computer simulation, we show that the wakefield driven by an ultrashort laser pulse in high-density plasma periodically reverses its polarity due to the carrier-envelope phase shift of the driver. The wakefield polarity reversal occurs on spatial scales shorter than the typical length considered for electron acceleration with the laser-wakefield mechanism. Consequently, the energies of accelerated electrons are significantly affected.
View Article and Find Full Text PDFRelativistic flying forcibly oscillating reflective diffraction gratings are formed by an intense laser pulse (driver) in plasma. The mirror surface is an electron density singularity near the joining area of the wake wave cavity and the bow wave; it moves together with the driver laser pulse and undergoes forced oscillations induced by the field. A counterpropagating weak laser pulse (source) is incident at grazing angles, being efficiently reflected and enriched by harmonics.
View Article and Find Full Text PDFIntroduction: High exposure to heat and combustion byproducts is associated with health problems and an increased risk of cancer.
Objective: To study the effects of heat and smoke derived from burning on the upper airway of firefighters.
Methods: Thirteen firefighters underwent a 4-week training program in Compartment Fire Behavior Training simulators while working with live fire, heat, and smoke from pallets and oriented-strand board sheet burns.
The focused field and its intensity distribution achieved by the 4π-spherical focusing scheme are investigated within the framework of diffraction optics. Generalized mathematical formulas describing the spatial distributions of the focused electric and magnetic fields are derived for the transverse magnetic and transverse electric mode electromagnetic waves with and without the orbital angular momentum attribute. The mathematical formula obtained shows no singularity in the field in the focal region and satisfies the finite field strength and electromagnetic energy conditions.
View Article and Find Full Text PDFThe nuclear reaction known as proton-boron fusion has been triggered by a subnanosecond laser system focused onto a thick boron nitride target at modest laser intensity (∼10^{16}W/cm^{2}), resulting in a record yield of generated α particles. The estimated value of α particles emitted per laser pulse is around 10^{11}, thus orders of magnitude higher than any other experimental result previously reported. The accelerated α-particle stream shows unique features in terms of kinetic energy (up to 10 MeV), pulse duration (∼10 ns), and peak current (∼2 A) at 1 m from the source, promising potential applications of such neutronless nuclear fusion reactions.
View Article and Find Full Text PDFWe present the results of theoretical studies of formation and evolution of the current sheet in a colliosionless plasma during magnetic reconnection in relativistic limit. Relativistic magnetic reconnection is driven by parallel laser pulses interacting with underdense plasma target. Annihilation of laser created magnetic field of opposite polarity generates strong non-stationary electric field formed in between the region with opposite polarity magnetic field accelerating charged particles within the current sheet.
View Article and Find Full Text PDFBackground: The subscapularis musculotendinous unit provides a stabilizing effect on the glenohumeral joint and thus, enables normal active range of motion. As pathologies of the subscapularis tendon (SSC) are diagnosed with increased regularity, treatment strategies and their long-term consequences are of relevant interest. Therefore, the primary objective of this retrospective case series was to evaluate clinical and radiological long-term results after open repair of large SSC tears.
View Article and Find Full Text PDFThe Time-of-Flight (TOF) technique coupled with semiconductorlike detectors, as silicon carbide and diamond, is one of the most promising diagnostic methods for high-energy, high repetition rate, laser-accelerated ions allowing a full on-line beam spectral characterization. A new analysis method for reconstructing the energy spectrum of high-energy laser-driven ion beams from TOF signals is hereby presented and discussed. The proposed method takes into account the detector's working principle, through the accurate calculation of the energy loss in the detector active layer, using Monte Carlo simulations.
View Article and Find Full Text PDFAs an alternative to Compton backscattering and bremsstrahlung, the process of colliding high-energy electron beams with strong laser fields can more efficiently provide both a cleaner and brighter source of photons in the multi-GeV range for fundamental studies in nuclear and quark-gluon physics. In order to favor the emission of high-energy quanta and minimize their decay into electron-positron pairs, the fields must not only be sufficiently strong, but also well localized. We here examine these aspects and develop the concept of a laser-particle collider tailored for high-energy photon generation.
View Article and Find Full Text PDFAerosol nanoparticle injectors are fundamentally important for experiments where container-free sample handling is needed to study isolated nanoparticles. The injector consists of a nebuliser, a differential pumping unit, and an aerodynamic lens to create and deliver a focused particle beam to the interaction point inside a vacuum chamber. The tightest focus of the particle beam is close to the injector tip.
View Article and Find Full Text PDFIntroduction: Difficulties or limitations in producing high-pitched sounds while singing may be due to the vocal technique used or organic factor. The observation of such difficulty or limitation by singing teachers is one of the main reasons affected individuals are referred to otolaryngologists.
Objective: To evaluate the laryngostroboscopic and electromyographic changes in the cricothyroid muscles of singers with difficulties or limitations producing high-pitched sounds.
Guiding of relativistically intense laser pulses with peak power of 0.85 PW over 15 diffraction lengths was demonstrated by increasing the focusing strength of a capillary discharge waveguide using laser inverse bremsstrahlung heating. This allowed for the production of electron beams with quasimonoenergetic peaks up to 7.
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