Search results for "Multichannel"

Using the r package spatstat to assess inhibitory effects of microregional hypoxia on the infiltration of cancers of the head and neck region by cyto…

2021

Simple Summary Progress in the field of in situ proteomics allows for the simultaneous detection of multiple biomarkers within one cancer tissue specimen. As a result, biological hypotheses previously only assessable ex vivo can now be studied in human cancer tissue. However, methods for objective analysis have so far been lacking behind. In this study, we established a free, objective, and entirely open-source-based method for the analysis of multiplexed immunofluorescence specimens. This will gain further importance with the availability of more advanced multiplexing methods in the future. Abstract (1) Background: The immune system has physiological antitumor activity, which is partially …

Luminescent CdSe Quantum Dot Arrays for Rapid Sensing of Explosive Taggants

2022

Chemical sensors based on fluorescent quantum dots have attracted intense interest because of their excellent optical and electronic properties compared to the routinely employed fluorescent organic dyes. This study reports a CdSe QD-polymer-based luminescent chemosensor, which is based on an array containing either green-emitting or red-emitting CdSe QDs embedded in polycaprolactone as a polymer host matrix. We evaluate the sensing capability of the nanocomposites by exposing both sensors to vapors of explosive taggants, explosive-like molecules, and some common solvents. Both nanocomposites exhibit a very fast response time of <30 s. The limit of detection of the sensors for 3-nitrotoluen…

Reliability in perimetric multichannel contrast sensitivity measurements

2014

Background: In this study, the reliability of perimetric contrast sensitivity measurements favouring the achromatic, the red-green and the blue-yellow post-receptorial mechanisms was analysed. Methods: A new technique, multichannel ATD perimetry, provides spatial and temporal stimuli favouring the detection by an achromatic mechanism (A), from a magno or parvocellular origin or by a red-green (RG) chromatic mechanism, with a parvocellular origin or a blue-yellow (BY) mechanism, with a koniocellular origin. The repeatability and reproducibility of contrast sensitivity measurements with these stimuli were studied in a group of 40 healthy subjects. The analysis was carried out on 21 testing po…

Spatial variability of muscle activity during human walking: The effects of different EMG normalization approaches

2015

Human leg muscles are often activated inhomogeneously, e.g. in standing. This may also occur in complex tasks like walking. Thus, bipolar surface electromyography (sEMG) may not accurately represent whole muscle activity. This study used 64-electrode high-density sEMG (HD-sEMG) to examine spatial variability of lateral gastrocnemius (LG) muscle activity during the stance phase of walking, maximal voluntary contractions (MVCs) and maximal M-waves, and determined the effects of different normalization approaches on spatial and inter-participant variability. Plantar flexion MVC, maximal electrically elicited M-waves and walking at self-selected speed were recorded in eight healthy males aged 2…

Multi-channel electromyography during maximal isometric and dynamic contractions.

2013

Motor unit behavior differs between contraction types at submaximal contraction levels, however is challenging to study during maximal voluntary contractions (MVCs). With multi-channel surface electromyography (sEMG), mean physiological characteristics of the active motor units can be extracted. Two 8-electrode sEMG arrays were attached on biceps brachii muscle (one on each head) to examine behavior of sEMG variables during isometric, eccentric and concentric MVCs of elbow flexors in 36 volunteers. On average, isometric (364 ± 88N) and eccentric (353 ± 74N) MVCs were higher than concentric (290 ± 73N) MVC (p0.001). Mean muscle fiber conduction velocity (CV) was highest during eccentric MVC …

Evaluation of esophageal motility using multichannel intraluminal impedance in healthy children and children with gastroesophageal reflux: comments

2011

Comparison of different sets of array configurations for multichannel 2D ERT acquisition

2017

Abstract Traditional electrode arrays such Wenner-Schlumberger or dipole-dipole are still widely used thanks to their well-known properties but the array configurations are generally not optimized for multi-channel resistivity measures. Synthetic datasets relating to four different arrays, dipole-dipole (DD), pole-dipole (PD), Wenner-Schlumberger (WS) and a modified version of multiple gradient (MG), have been made for a systematic comparison between 2D resistivity models and their inverted images. Different sets of array configurations generated from simple combinations of geometric parameters (potential dipole lengths and dipole separation factors) were tested with synthetic and field dat…

Evaluation of esophageal motility and reflux in children treated for esophageal atresia with the use of combined multichannel intraluminal impedance …

2011

Abstract Background Gastroesophageal reflux (GER) and dysmotility are frequent in patients treated for esophageal atresia (EA). This aim of this study is to evaluate GER and dysmotility in young EA patients using pH–multichannel intraluminal impedance (pH-MII). Methods Fifteen patients with a mean age of 7.5 years (group 1) have been studied and compared with 15 children without congenital malformation, submitted to pH-MII for suspected GER (group 2). These latter patients serve as a control group of healthy subjects. The following impedance reflux and motility parameters have been studied on 10 standardized swallows: number of reflux episodes, mean acid clearing time, median bolus clearing…

Gastroesophageal reflux in patients treated for congenital diaphragmatic hernia: short- and long-term evaluation with multichannel intraluminal imped…

2013

The incidence of GER, related symptoms and complications in patients treated for congenital diaphragmatic hernia (CDH) are poorly defined. The aim was to evaluate incidence and development of GER in children treated for CDH in a short- and long-term follow-up period, identifying potential risk factors of morbidity. Thirty-six patients were evaluated with pH-MII at a median age of 6 months (T1) and re-evaluated with pH-MII and endoscopy at a median age of 5 years (T2). The incidence of reflux was 83 % in T1 and 61 % in T2; the incidence of symptoms was 62 % in T1 and 38 % in T2. In both groups the reflux was mainly non-acidic. Patch, intrathoracic stomach and esophageal dysmotility were risk…

Evaluation of esophageal motility and reflux in children treated for congenital diaphragmatic hernia with the use of combined multichannel intralumin…

2011

Abstract Background Gastroesophageal reflux (GER) is frequently observed in children treated for congenital diaphragmatic hernia (CDH) at birth, as well as esophageal dysmotility, that has been hypothesized to be caused by innervatory anomalies. The aim of this study is to evaluate GER and dysmotility in young patients with CDH using pH-multichannel intraluminal impedance. Methods Thirty children (17 boys and 13 girls) who underwent repair for CDH between 2002 and 2007 with a median age of 5.2 years (range, 3-10 years) were included in the study. All patients were operated on with a subcostal laparotomy incision and had a left-sided diaphragmatic defect. The defect repair required an artifi…