A Two-Dimensional Second Order Conservative Front-Tracking Method with an Original Marker Advection Approach Based on Jump Relations

A two-dimensional front-tracking method is developed for handling complex shape interfaces satisfying the volume conservation. In order to validate the proposed front-tracking method, a complete convergence study is carried out on several analytical test cases for which the interface is widely stretched and deformed. Comparisons to different existing approaches show that our front-tracking method is second order accurate in space with lower errors than existing interface tracking techniques of the literature.We also propose an original marker advection method which takes into account the jump relations valid at interface in order to deal with the contrast of physical properties encountered in two-phase flow simulations. The conservative front-tracking method computed in this work is shown to be able to describe interfaces with high accuracy even for poorly resolved Eulerian grids.     

V-EMF treatment of facial scar: First results

Aim of studyThis is a retrospective study aimed at evaluating the effectiveness of the use of electromagnetic fields and negative pressure treatment (V-EMF) for facial scars, from an aesthetic and functional point of view, and considering the variations in the levels of hydration.Material and methods25 subjects with facial scarring were re-evaluated after being treated with the V-EMF method. The hydration levels of the scars before and after treatment were compared. The results were evaluated considering the satisfaction levels of the patients with the VAS, and of the medical specialists who performed the treatment, and of 3 independent dermatologists with the Likert scale.ResultsMean hydration levels of scars went from 41.8 to 53.3, with mean hydration levels of healthy reference points equal to 54.6. The minimum patient satisfaction level was 2 in the VAS. The minimum level of satisfaction of specialists and dermatologists was equal to IV on the Likert scale for all patients, except for 1 subject in which it was III for the specialist who had treated him. Anti-aging and re-pigmentation effects were also noted as secondary results.ConclusionsFrom an aesthetic and functional point of view, and for the overall anti-aging effect of the treated area, V-EMF applied to facial scars has shown extremely promising results.     

Effects of continuous positive airway pressure treatment on aortic stiffness in patients with resistant hypertension and obstructive sleep apnea: A randomized controlled trial

Resistant hypertension (RHT) is associated with obstructive sleep apnea (OSA) and increased aortic stiffness, measured by carotid‐femoral pulse wave velocity (cf‐PWV). We aimed to evaluate in a randomized controlled trial, the effect of Continuous positive airway pressure (CPAP) treatment on cf‐PWV in comparison with a control group in patients with RHT and moderate‐severe OSA. One‐hundred and sixteen patients were randomized to 6‐month CPAP treatment (56 patients) or no therapy (60 patients), while keeping their antihypertensive treatment unchanged. Carotid‐femoral pulse wave velocity was performed at the beginning and end of the 6‐month period. Intention‐to‐treat intergroup differences in cf‐PWV changes were assessed by a generalized mixed‐effects model with the allocation group as a fixed factor and adjusted for age, sex, changes in mean arterial pressure and the baseline cf‐PWV values. Subgroup sensitivity analyses were performed, excluding patients with low CPAP adherence and low cf‐PWV at baseline. CPAP and control groups had similar clinic‐laboratorial characteristics. Patients had a mean cf‐PWV of 9.4 ± 1.6 m/s and 33% presented cf‐PWV > 10 m/s. During treatment, the control group had a mean increase in cf‐PWV of +0.43 m/s (95% confidence interval [CI], +0.14 to +0.73 m/s; p = .005), whereas the CPAP group had a mean increase of +0.03 m/s (95% CI, ?0.33 to +0.39 m/s; p = .87), resulting in a mean difference in changes between CPAP and control of ?0.40 m/s (95% CI, ?0.82 to +0.02 m/s; p = .059). Subgroup analyses did not change the results. In conclusion, a 6‐month CPAP treatment did not reduce aortic stiffness, measured by cf‐PWV, in patients with RHT and moderate/severe OSA, but treatment may prevent its progression, in contrast to no‐CPAP therapy.     

Untethered firing fields and intermittent silences: Why grid‐cell discharge is so variable

Grid cells in medial entorhinal cortex are notoriously variable in their responses, despite the striking hexagonal arrangement of their spatial firing fields. Indeed, when the animal moves through a firing field, grid cells often fire much more vigorously than predicted or do not fire at all. The source of this trial‐to‐trial variability is not completely understood. By analyzing grid‐cell spike trains from mice running in open arenas and on linear tracks, we characterize the phenomenon of “missed” firing fields using the statistical theory of zero inflation. We find that one major cause of grid‐cell variability lies in the spatial representation itself: firing fields are not as strongly anchored to spatial location as the averaged grid suggests. In addition, grid fields from different cells drift together from trial to trial, regardless of whether the environment is real or virtual, or whether the animal moves in light or darkness. Spatial realignment across trials sharpens the grid representation, yielding firing fields that are more pronounced and significantly narrower. These findings indicate that ensembles of grid cells encode relative position more reliably than absolute position.     

Association between fetoplacental Doppler results,placental pathology,and angiogenic factors among pregnant women with anxiety

ObjectiveThis study aimed to evaluate whether state and trait anxiety among pregnant women were associated with fetoplacental Doppler findings, abnormal placental pathology, and placental angiogenic factors.Materials and methodsA total of 102 pregnant women at 32–35 gestational weeks were recruited and examined prospectively. State and trait anxiety were measured using the State-Trait Anxiety Inventory. Using Doppler ultrasound, pulsatility index (PI) of the umbilical artery (UA), middle cerebral artery (MCA), and uterine artery (UtA) and cerebroplacental ratio (CPR) were determined. Doppler parameters were converted into multiples of the median (MoM). Abnormal placental pathology was classified into 2 groups: vascular underperfusion (VU) and histological chorioamnionitis (HCA). Immunohistochemical analysis was performed to examine placental cells staining positive for placental growth factor (PLGF) and hypoxia-inducible factor-1-α (HIF-1α), which are markers for angiogenesis and hypoxic status, respectively.ResultsWomen with high state anxiety scores had low MCA-PI MoM and CPR MoM, while those with high trait anxiety scores had low MCA-PI MoM. VU was associated with a higher incidence of high trait anxiety scores, and HCA was associated with a higher incidence of high state and trait anxiety scores. Regression analysis showed a relationship between maternal state anxiety on MCA-PI MoM and HCA after controlling for covariates. Maternal trait anxiety exhibited relationships with VU and HCA after adjustment.ConclusionOur results demonstrated that maternal anxiety is associated with altered fetal cerebral blood flow and abnormal placental pathology but is not associated with uteroplacental insufficiency and placental angiogenic factors.     

Síndromes de compresión vascular. Valor de la ecografía Doppler

Vascular compression syndromes arise when a vessel in a tight anatomic space is entrapped by another structure, resulting in diverse symptoms for which different imaging tests are used to diagnose. Radiologists need to be familiar with vascular compression syndromes and to be able to identify their most representative findings. This paper aims to review the principal symptoms of vascular compression, describing and illustrating the key findings on Doppler ultrasonography that enable accurate diagnosis and guide further workup, avoiding unnecessary invasive tests and pointing to the appropriate treatment.     

Acute effects of adaptive Deep Brain Stimulation in Parkinson’s disease

BackgroundBeta-based adaptive Deep Brain Stimulation (aDBS) is effective in Parkinson’s disease (PD), when assessed in the immediate post-implantation phase. However, the potential benefits of aDBS in patients with electrodes chronically implanted, in whom changes due to the microlesion effect have disappeared, are yet to be assessed.MethodsTo determine the acute effectiveness and side-effect profile of aDBS in PD compared to conventional continuous DBS (cDBS) and no stimulation (NoStim), years after DBS implantation, 13 PD patients undergoing battery replacement were pseudo-randomised in a crossover fashion, into three conditions (NoStim, aDBS or cDBS), with a 2-min interval between them. Patient videos were blindly evaluated using a short version of the Unified Parkinson’s Disease Rating Scale (subUPDRS), and the Speech Intelligibility Test (SIT).ResultsMean disease duration was 16 years, and the mean time since DBS-implantation was 6.9 years. subUPDRS scores (11 patients tested) were significantly lower both in aDBS (p=<.001), and cDBS (p = .001), when compared to NoStim. Bradykinesia subscores were significantly lower in aDBS (p = .002), and did not achieve significance during cDBS (p = .08), when compared to NoStim. Two patients demonstrated re-emerging tremor during aDBS. SIT scores of patients who presented stimulation-induced dysarthria significantly worsened in cDBS (p = .009), but not in aDBS (p = .407), when compared to NoStim. Overall, stimulation was applied 48.8% of the time during aDBS.ConclusionBeta-based aDBS is effective in PD patients with bradykinetic phenotypes, delivers less stimulation than cDBS, and potentially has a more favourable speech side-effect profile. Patients with prominent tremor may require a modified adaptive strategy.