Search results for "high-frequency"

Effect of High-Frequency Oscillations on Cough Peak Flows Generated by Mechanical In-Exsufflation in Medically Stable Subjects With Amyotrophic Later…

2016

BACKGROUND: Mechanically assisted coughing with mechanical in-exsufflation (MI-E) is recommended for noninvasive management of respiratory secretions in amyotrophic lateral sclerosis (ALS). To improve the effectiveness of the technique, a new device combining MI-E with high-frequency oscillations (HFO) has been developed. This work aimed to assess the effect of HFO on the cough peak flow generated by MI-E in medically stable subjects with ALS. METHODS: This was a prospective study that included subjects with ALS in a medically stable condition. Cough peak flow generated by MI-E was measured in 4 situations: without HFO, with HFO during insufflation, with HFO during exsufflation, and with HF…

Noninvasive oscillatory ventilation (NHFOV) in infants: Another brick in the wall of paediatric noninvasive ventilation?

2016

EDITORIAL

Noninvasive oscillatory ventilation (NHFOV) in infants: Another brick in the wall of paediatric noninvasive ventilation?

2016

Radiofrequency, High-frequency and electrocautery Treatments vs Partial Inferior Turbinotomy

2009

Abstract OBJECTIVE: To compare the microscopic and macroscopic effects of radiofrequency, high-frequency, and electrocautery therapies with partial inferior turbinotomy in the treatment of nasal obstruction caused by inferior turbinate hypertrophy. DESIGN: Nonrandomized controlled trial. SETTING: Department of Otolaryngology-Head and Neck Surgery, University of Genoa. PATIENTS: The study included 80 patients affected by nasal obstruction from hypertrophied inferior turbinates. INTERVENTIONS: Homogeneous patient groups A, B, C, and D underwent radiofrequency, high-frequency, and electrocautery treatments and partial inferior turbinotomy, respectively, to surgically reduce hypertrophied infer…

High-frequency trading and networked markets

2021

Financial markets have undergone a deep reorganization during the last 20 y. A mixture of technological innovation and regulatory constraints has promoted the diffusion of market fragmentation and high-frequency trading. The new stock market has changed the traditional ecology of market participants and market professionals, and financial markets have evolved into complex sociotechnical institutions characterized by a great heterogeneity in the time scales of market members’ interactions that cover more than eight orders of magnitude. We analyze three different datasets for two highly studied market venues recorded in 2004 to 2006, 2010 to 2011, and 2018. Using methods of complex network th…

Altered processing of sensory stimuli in patients with migraine.

2014

Migraine is a cyclic disorder, in which functional and morphological brain changes fluctuate over time, culminating periodically in an attack. In the migrainous brain, temporal processing of external stimuli and sequential recruitment of neuronal networks are often dysfunctional. These changes reflect complex CNS dysfunction patterns. Assessment of multimodal evoked potentials and nociceptive reflex responses can reveal altered patterns of the brain's electrophysiological activity, thereby aiding our understanding of the pathophysiology of migraine. In this Review, we summarize the most important findings on temporal processing of evoked and reflex responses in migraine. Considering these d…

A new method to "clean up" ultra high-frequency data

2007

In the applied econometrics, the availability of ultra high-frequency databases is having an important impact on the research market microstructure theory. The ultra high-frequency databases contain detailed reports of all the financial market activity information which is available. However, ultra high-frequency databases cannot be directly used. On one hand recording mistakes can be present, on the other hand missing information has to be inferred from the available data. In this paper, we propose a simple method in order to clean up the ultra high-frequency data from possible errors and we examine the method efficacy when we analyze data by using an autoregressive conditional duration (A…

HOT-ELECTRON NOISE FEATURES IN SILICON CRYSTALS OPERATING UNDER PERIODIC SIGNALS

2014

We study the intrinsic noise in n-type Si crystals operating under high-frequency periodic electric fields. To simulate the dy- namics of electrons in the bulk, by taking into account the main details of band structure, scattering processes, as well as heating effects, a Monte Carlo approach is used. The noise properties are investigated by computing the velocity fluctuations correlation function, its spectral density, and the total noise power for different values of the amplitude and frequency of the driving field. We show that the noise features are significantly affected by the electric field amplitude and frequency and discuss their peculiari- ties in comparison with those exhibited in…

Coastal high-frequency radars in the Mediterranean – Part 1: Status of operations and a framework for future development

2022

Due to the semi-enclosed nature of the Mediterranean Sea, natural disasters and anthropogenic activities impose stronger pressures on its coastal ecosystems than in any other sea of the world. With the aim of responding adequately to science priorities and societal challenges, littoral waters must be effectively monitored with high-frequency radar (HFR) systems. This land-based remote sensing technology can provide, in near-real time, fine-resolution maps of the surface circulation over broad coastal areas, along with reliable directional wave and wind information. The main goal of this work is to showcase the current status of the Mediterranean HFR network and the future roadmap for orches…

Coastal high-frequency radars in the Mediterranean - Part 2: Applications in support of science priorities and societal needs

2022

The Mediterranean Sea is a prominent climate-change hot spot, with many socioeconomically vital coastal areas being the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, high-frequency radars (HFRs) have been steadily gaining recognition as an effective land-based remote sensing technology for continuous monitoring of the surface circulation, increasingly waves and occasionally winds. HFR measurements have boosted the thorough scientific knowledge of coastal processes, also fostering a broad range of applications, which has promoted their integration in coastal ocean …