FLIP: a novel method for patient-specific dose quantification in circulating blood in large vessels during proton or photon external beam radiotherapy treatments.

To provide a novel and personalized method (and Irradiation Personalized) using patient-specific circulating blood flows and individualized time-dependent irradiation distributions, to quantify the dose delivered to blood in large vessels during proton or photon external beam radiotherapy.Patient-specific data were obtained from ten cancer patients undergoing radiotherapy, including the blood velocity field in large vessels and the temporal irradiation scheme using photons or protons. The large vessels and the corresponding blood flow velocities are obtained from phase-contrast MRI sequences.

Low-Dose Ionizing γ-Radiation Elicits the Extrusion of Neutrophil Extracellular Traps.

Purpose: Patients with cancer frequently undergo radiotherapy in their clinical management with unintended irradiation of blood vessels and copiously irrigated organs in which polymorphonuclear leukocytes circulate. Following the observation that such low doses of ionizing radiation are able to induce neutrophils to extrude neutrophil extracellular traps (NET), we have investigated the mechanisms, consequences, and occurrence of such phenomena in patients undergoing radiotherapy.

Experimental Design: NETosis was analyzed in cultures of neutrophils isolated from healthy donors, patients with cancer, and cancer-bearing mice under confocal microscopy.

Detailed dosimetric evaluation of inter-fraction and respiratory motion in lung stereotactic body radiation therapy based on daily 4D cone beam CT images.

. Periodic respiratory motion and inter-fraction variations are sources of geometric uncertainty in stereotactic body radiation therapy (SBRT) of pulmonary lesions. This study extensively evaluates and validates the separate and combined dosimetric effect of both factors using 4D-CT and daily 4D-cone beam CT (CBCT) dose accumulation scenarios.

Simple and Autonomous Sleep Signal Processing System for the Detection of Obstructive Sleep Apneas.

Obstructive sleep apnea (OSA) is a common sleep disorder characterized by repetitive upper airway obstruction, intermittent hypoxemia, and recurrent awakenings during sleep. The most used treatment for this syndrome is a device that generates a positive airway pressure—Continuous Positive Airway Pressure (CPAP), but it works continuously, whether or not there is apnea. An alternative consists on systems that detect apnea episodes and produce a stimulus that eliminates them.

Evaluation of the Ultrastructural and In Vitro Flow Properties of the PRESERFLO MicroShunt.

Purpose: To measure the in vitro flow properties of the PRESERFLO implant for comparison with the theoretical resistance to flow.

Methods: The PRESERFLO was designed to control the flow of aqueous humor according to the Hagen-Poiseuille (HP) equation. Scanning electron microscopy (SEM) was performed to analyze the ultrastructure, and flow measurements were carried out using a gravity-flow setup.

A method using 4D dose accumulation to quantify the interplay effect in lung stereotactic body radiation therapy.

The purpose of this study was to devise and evaluate a method to quantify the dosimetric uncertainty produced by the interplay between the movement of multileaf collimator and respiratory motion in lung stereotactic body radiation therapy. The method calculates the dose distribution for all control points from a dynamic treatment in all respiratory phases. The methodology includes some characteristics of a patient's irregular breathing patterns.

A novel concept to include uncertainties in the evaluation of stereotactic body radiation therapy after 4D dose accumulation using deformable image registration.

Purpose: To use four-dimensional (4D) dose accumulation based on deformable image registration (DIR) to assess dosimetric uncertainty in lung stereotactic body radiation therapy (SBRT) treatment planning. A novel concept, the Evaluation Target Volume (ETV), was introduced to achieve this goal.

Methods: The internal target volume (ITV) approach was used for treatment planning for 11 patients receiving lung SBRT.

Experimental lateral wall boundary layer behavior of a differentially rotating split-cylinder flow.

The cylindrical wall boundary layer of a closed cylinder split in two halves at the equator is studied experimentally. When these two parts rotate in exact corotation the internal flow is essentially in solid-body rotation at the angular velocity of both halves. When a slight difference between the rotation frequencies is established a secondary flow is created due to the differential rotation between both sides and restricted to the boundary layer.

Instabilities triggered in different conducting fluid geometries due to slowly time-dependent magnetic fields.

The main objective of this work is the study and analysis of non-linearities forced through oscillating magnetic fields in a conducting fluid where the instabilities are triggered due to magnetohydrodynamic forces. Different geometries have been studied and different surface patterns that break the symmetries have been observed. First, an InGaSn drop of fluid where the system breaks the azimuthal and radial symmetries depending on the volume is observed.

Instabilities of conducting fluid layers in weak time-dependent magnetic fields.

We present the experimental analysis of the instabilities generated on a large drop of liquid metal by a time-dependent magnetic field. The study is done exploring the range of tiny values of the control parameter (the ratio between the Lorentz forces and inertia) avoiding nonlinear effects. Two different instabilities break the symmetries generating spatial patterns that appear without a threshold for some specific frequencies (up to the experimental precision) and have been observed for parameter values two orders of magnitude lower than in previously published experiments [J.

Accuracy of a Laryngopharyngeal Endoscopic Esthesiometer (LPEER) for Evaluating Laryngopharyngeal Mechanosensitivity: A Validation Study in a Prospectively Recruited Cohort of Patients.

Recent studies have shown an association between alterations in laryngopharyngeal mechanosensitivity (LPMS) and dysphagia, obstructive sleep apnea, and chronic cough hypersensitivity syndrome. A previous reliability study of a new laryngopharyngeal endoscopic esthesiometer and rangefinder (LPEER) showed high intra- and inter-rater reliability; however, its accuracy has not been tested. We performed an accuracy study of the LPEER in a prospectively and consecutively recruited cohort of 118 patients at two tertiary care university hospitals.

Commissioning of small field size radiosurgery cones in a 6-MV flattening filter-free beam.

This study aimed to describe the commissioning of small field size radiosurgery cones in a 6-MV flattening filter free (FFF) beam and report our measured values. Four radiosurgery cones of diameters 5, 10, 12.5, and 15 mm supplied by Elekta Medical were commissioned in a 6-MV FFF beam from an Elekta Versa linear accelerator.

Reliability of a laryngo-pharyngeal esthesiometer and a method for measuring laryngo-pharyngeal mechano-sensitivity in a prospectively recruited cohort of patients.

There are not reliable methods for measuring laryngo-pharyngeal mechano-sensitivity (LPMS). We aimed to determine the reliability of a new method for measuring LPMS using a new laryngo-pharyngeal esthesiometer (LPEER) in a prospective cohort of dysphagic stroke and non-dysphagic patients. The patients underwent clinical and endoscopic evaluations of swallowing (FESSST).

Bifurcation induced by the aspect ratio in a turbulent von Kármán swirling flow.

We evaluate the effect of the aspect ratio, i.e., the distance between the propellers H divided by the diameter D, on the slow dynamics of a von Kármán swirling flow driven by two propellers in a closed cylinder.

Design, development and validation of a new laryngo-pharyngeal endoscopic esthesiometer and range-finder based on the assessment of air-pulse variability determinants.

Background: Laryngo-pharyngeal mechano-sensitivity (LPMS) is involved in dysphagia, sleep apnea, stroke, irritable larynx syndrome and cough hypersensitivity syndrome among other disorders. These conditions are associated with a wide range of airway reflex abnormalities. However, the current device for exploring LPMS is limited because it assesses only the laryngeal adductor reflex during fiber-optic endoscopic evaluations of swallowing and requires a high degree of expertise to obtain reliable results, introducing intrinsic expert variability and subjectivity.

Stochastic dynamics of particles trapped in turbulent flows.

The long-time dynamics of large particles trapped in two nonhomogeneous turbulent shear flows is studied experimentally. Both flows present a common feature, a shear region that separates two colliding circulations, but with different spatial symmetries and temporal behaviors. Because large particles are less and less sensitive to flow fluctuations as their size increases, we observe the emergence of a slow dynamics corresponding to back-and-forth motions between two attractors, and a super-slow regime synchronized with flow reversals when they exist.

Development and clinical evaluation of a simple optical method to detect and measure patient external motion.

A simple and independent system to detect and measure the position of a number of points in space was devised and implemented. Its application aimed to detect patient motion during radiotherapy treatments, alert of out-of-tolerances motion, and record the trajectories for subsequent studies. The system obtains the 3D position of points in space, through its projections in 2D images recorded by two cameras.

Experimental pencil beam kernels derivation for 3D dose calculation in flattening filter free modulated fields.

This paper presents a method to obtain the pencil-beam kernels that characterize a megavoltage photon beam generated in a flattening filter free (FFF) linear accelerator (linac) by deconvolution from experimental measurements at different depths. The formalism is applied to perform independent dose calculations in modulated fields. In our previous work a formalism was developed for ideal flat fluences exiting the linac's head.

Experimental dynamics in magnetic field-driven flows compared to thermoconvective convection.

We compare the dynamics obtained in two intermediate aspect ratio (diameter over height) experiments. These systems have rotational symmetry and consist of fluid layers that are destabilized using two different methods. The first one is a classical Bénard-Marangoni experiment, where the destabilizing forces, buoyancy and surface tension, are created by temperature gradients.

Application of spherical diodes for megavoltage photon beams dosimetry.

Purpose: External beam radiation therapy (EBRT) usually uses heterogeneous dose distributions in a given volume. Designing detectors for quality control of these treatments is still a developing subject. The size of the detectors should be small to enhance spatial resolution and ensure low perturbation of the beam.

Inverse cascades sustained by the transfer rate of angular momentum in a 3D turbulent flow.

The existence of energy cascades as signatures of conserved magnitudes is one of the universal characteristics of turbulent flows. In homogeneous 3D turbulence, the energy conservation produces a direct cascade from large to small scales, although in 2D, it produces an inverse cascade pointing towards small wave numbers. In this Letter, we present the first evidence of an inverse cascade in a fully developed 3D experimental turbulent flow where the conserved magnitude is the angular momentum.

Impact of time-dependent nonaxisymmetric velocity perturbations on dynamo action of von Kármán-like flows.

We present numerical simulations of the kinematic induction equation in order to examine the dynamo efficiency of an axisymmetric von Kármán-like flow subject to time-dependent nonaxisymmetric velocity perturbations. The numerical model is based on the setup of the French von Kármán-sodium dynamo (VKS) and on the flow measurements from a water experiment conducted at the University of Navarra in Pamplona, Spain. The principal experimental observations that are modeled in our simulations are nonaxisymmetric vortexlike structures which perform an azimuthal drift motion in the equatorial plane.

Intensity modulated dose calculation with an improved experimental pencil-beam kernel.

Purpose: This article presents an improved pencil-beam dose calculation formalism based on an experimental kernel obtained by deconvolution. The new algorithm makes it possible to calculate the absorbed dose for all field sizes.

Methods: The authors have enhanced their previous work [J.

Experimentally observed route to spatiotemporal chaos in an extended one-dimensional array of convective oscillators.

We report experimental evidence of the route to spatiotemporal chaos in a large one-dimensional array of hotspots in a thermoconvective system. As the driving force is increased, a stationary cellular pattern becomes unstable toward a mixed pattern of irregular clusters which consist of time-dependent localized patterns of variable spatiotemporal coherence. These irregular clusters coexist with the basic cellular pattern.

Subcritical instabilities in a convective fluid layer under a quasi-one-dimensional heating.

The study and characterization of the diversity of spatiotemporal patterns generated when a rectangular layer of fluid is locally heated beneath its free surface is presented. We focus on the instability of a stationary cellular pattern of wave number ks which undergoes a globally subcritical transition to traveling waves by parity-breaking symmetry. The experimental results show how the emerging traveling mode (2ks/3) switches on a resonant triad (ks, ks/2, 2ks/3) within the cellular pattern yielding a "mixed" pattern.