Abstract Grenier SG, McGill SM. Quantification of lumbar stability by using 2 different abdominal activation strategies. Objective To determine whether the abdominal hollowing technique is more ...effective for lumbar spine stabilization than a full abdominal muscle cocontraction. Design Within-subject, repeated-measures analysis of variance was used to examine the effect of combining each of 4 loading conditions with either the hollow or brace condition on the dependent variables of stability and compression. A simulation was also conducted to assess the outcome of a person activating just the transversus abdominis during the hollow. Setting Laboratory. Participants Eight healthy men (age range, 20−33y). Interventions Electromyography and spine kinematics were recorded during an abdominal brace and a hollow while supporting either a bilateral or asymmetric weight in the hands. Main Outcome Measures Spine stability index and lumbar compression were calculated. Results In the simulation “ideal case,” the brace technique improved stability by 32%, with a 15% increase in lumbar compression. The transversus abdominis contributed .14% of stability to the brace pattern with a less than 0.1% decrease in compression. Conclusions Whatever the benefit underlying low-load transversus abdominis activation training, it is unlikely to be mechanical. There seems to be no mechanical rationale for using an abdominal hollow, or the transversus abdominis, to enhance stability. Bracing creates patterns that better enhance stability.
The conventional approach to cardiac magnetic resonance (CMR) involving breath holds, electrocardiography-gating, and acquisition of a short-axis (SAX) image stack, introduces technical and ...logistical challenges for assessing exercise left ventricular (LV) function. Real-time, free-breathing CMR acquisition of long-axis (LAX) images overcomes these issues and also enables assessment of global longitudinal strain (GLS). We evaluated the reliability of a free-breathing LAX approach compared to the standard SAX approach and the reproducibility of free-breathing LAX. LV SAX (contiguous stack) and LAX (two-chamber and four-chamber) 3T CMR cine images were acquired four times within one scan in 32 women with cardiovascular risk factors (56±10 years, 28±4 kg/m2) as follows: 1) resting, gated-segmented, end-expiration breath-hold; 2) resting, real-time, free-breathing; 3) test-retest set of resting, real-time, free-breathing; 4) peak exercise (incremental-to-maximum, in-magnet, stepper test), real-time, free-breathing. A second scan was performed within one week in a subset (n = 5) to determine reproducibility of peak exercise measures. Reliability and agreement of the free-breathing LAX approach with the conventional SAX approach were assessed by intraclass correlation coefficient (ICC) and Bland-Altman plots, respectively. Normal control GLS reserve was also acquired in a separate set of 12 young, healthy control women (25±4 years, 22±2 kg/m2) for comparison. Comparisons of LV volumes and function among all techniques at rest had good-to-excellent reliability (ICC = 0.80-0.96), and excellent reliability between peak exercise free-breathing LAX and SAX evaluations (ICC = 0.92-0.96). Higher resting heart rates with free-breathing acquisitions compared to breath-hold (mean difference, limits of agreement: 5, 1-12 beats per minute) reduced reliability for cardiac output (ICC = 0.67-0.79). Reproducibility of the free-breathing LAX approach was good-to-excellent at rest and peak exercise (ICC = 0.74-0.99). GLS exercise reserve was impaired in older women at cardiovascular risk compared to young healthy women (-4.7±2.3% vs -7.4±2.1%, p = 0.001). Real-time, free-breathing CMR with LAX evaluation provides a reliable and reproducible method to assess rest and peak exercise cardiac function, including GLS.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
This study aimed to characterize peak exercise cardiac function and thigh muscle fatty infiltration and their relationships with VO
2
peak among anthracycline-treated breast cancer survivors ...(BCS). BCS who received anthracycline chemotherapy ~ 1 year earlier (n = 16) and matched controls (matched-CON, n = 16) were enrolled. Resting and peak exercise cardiac function, myocardial T
1
mapping (marker of fibrosis), and thigh muscle fat infiltration were assessed by magnetic resonance imaging, and VO
2
peak by cycle test. Compared to matched-CON, BCS had lower peak SV (64 ± 9 vs 57 ± 10 mL/m
2
, p = 0.038), GLS (− 30.4 ± 2.2 vs − 28.0 ± 2.5%, p = 0.008), and arteriovenous oxygen difference (16.4 ± 3.6 vs 15.2 ± 3.9 mL/100 mL, p = 0.054). Mediation analysis showed: (1) greater myocardial T
1
time (fibrosis) is inversely related to cardiac output and end-systolic volume exercise reserve; (2) greater thigh muscle fatty infiltration is inversely related to arteriovenous oxygen difference; both of which negatively influence VO
2
peak. Peak SV (R
2
= 65%) and thigh muscle fat fraction (R
2
= 68%) were similarly strong independent predictors of VO
2
peak in BCS and matched-CON combined. Post-anthracyclines, myocardial fibrosis is associated with impaired cardiac reserve, and thigh muscle fatty infiltration is associated with impaired oxygen extraction, which both contribute to VO
2
peak.
The SDHCAL technological prototype is a 1 x 1 x 1.3 m super(3) high-granularity Semi-Digital Hadronic CALorimeter using Glass Resistive Plate Chambers as sensitive medium. It is one of the two HCAL ...options considered by the ILD Collaboration to be proposed for the detector of the future International Linear Collider project. The prototype is made of up to 50 GRPC detectors of 1 m super(2) size and 3 mm thickness each with an embedded semi-digital electronics readout that is autotriggering and power-pulsed. The GRPC readout is finely segmented into pads of 1 cm super(2). Measured performances of the GRPC and the full SDHCAL prototype in terms of homogeneity, low noise and energy resolution are presented in this proceeding.
Introduction
Inhibition capabilities have been shown to be a strong predictor of social and educational life outcomes (Mischel & Ebbesen, 1970; Shoda et al., 1990). Inhibition capabilities have an ...enormous impact on attention and impulsivity (Bari & Robbins, 2013). These two executive functions are associated with numerous psychiatric disorders but are not well understood in terms of white matter (WM) connectivity (Puiu et al., 2018). Novel techniques and statistical approaches in neuroimaging bring us closer to a biologically sustained model.
Objectives
This research aims to: 1) identify WM connections associated with attention/impulsivity performance and 2) characterize the differences in WM microstructure associated with the variation of the performance.
Methods
157 children (GESTE cohort, 8-12 years, 27 Dx ADHD, 2 Dx ASD) with b=1500mm
2
/s, 2mm isotropic dMRI acquisitions were included. Tractography was performed with TractoFlow pipeline (Theaud et al., 2020). Dimensionality reduction of diffusion metrics yielded two components : microstructural complexity (DTI Metrics, AFD & NuFo) and axonal density (AFD_fixel) (Chamberland et al., 2019). Attention/impulsivity were evaluated with the CPT3. Multivariate linear regression was performed in python.
Results
Lower microstructural complexity was associated with poorer attentional performance on regions of the parietal lobe to the occipital gyrus (P-O,
p
=0.044, R
2
=0.14, Figure 1.) and the Broadman’s area 8 to area 6 (SF8-SF6,
p
=0.002, R
2
=0.12, Figure 1.). Lower axonal density was associated with a less impulsive pattern on SF8-SF6 (
p
=0.001, R
2
=0.13, Figure 1.). Results remained significant when removing children with an ADHD or ASD diagnosis.
Conclusions
We identified underlying difference in WM microstructure that may be associated with the variation in attention/impulsivity performance in school-aged children.
Disclosure
No significant relationships.
The SDHCAL technological prototype is a 1 x 1 x 1.3 m super(3) high-granularity Semi-Digital Hadronic CALorimeter using Glass Resistive Plate Chambers as sensitive medium. It is one of the two HCAL ...options considered by the ILD Collaboration to be proposed for the detector of the future International Linear Collider project. The prototype is made of up to 50 GRPC detectors of 1 m super(2) size and 3 mm thickness each with an embedded semi-digital electronics readout that is autotriggering and power-pulsed. The GRPC readout is finely segmented into pads of 1 cm super(2). This proceeding describes the prototype, its operation and its performance in energy reconstruction. Aspects of the GRPC readout modelling and comparisons with simulations are also presented.
To evaluate the potential of (18)F-fluoro-deoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) for early therapeutic intervention in patients with probable or confirmed ...tuberculosis (TB).
Twenty-one consecutive human immunodeficiency virus negative patients were prospectively included. All patients underwent (18)F-FDG PET/CT before and after 1 month of anti-tuberculosis treatment. The maximum standardised uptake value (SUV(max)) of the most (18)F-FDG avid lesions was recorded.
The median age of patients was 36 years (range 18-84); 33.3% were male, 80.9% were born in endemic countries, and 23.8% had a past history of TB. TB was confirmed on culture in 8, on histology in 9 and on the basis of clinical symptoms in 4 patients. (18)F-FDG PET/CT detected active pulmonary TB (n = 1), extra-pulmonary (n = 10) or both (n = 10). The second (18)F-FDG PET/CT showed reduced radiotracer uptake intensity in 19 of 21 patients, with a median percentage decrease of SUV(max) of 31% (range 2-84). Two patients showed no improvement. TB was ruled out in one patient during follow-up; the final diagnosis was a non-Hodgkin's lymphoma. The other patient was smear-positive for 3 months.
(18)F-FDG PET/CT allows an easy evaluation of early therapeutic response in patients with TB, particularly extra-pulmonary TB.
CMS iRPC FEB development and validation Gouzevitch, M.; El Sawy, M.; Alves, G.A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2024, Letnik:
1064
Journal Article
Recenzirano
Odprti dostop
In view of the High Luminosity upgrade of the CERN LHC, the forward CMS Muon spectrometer will be extended with two new stations of improved Resistive Plate Chambers (iRPC) covering the ...pseudorapidity range from 1.8 to 2.4. Compared to the present RPC system, the gap thickness is reduced to lower the avalanche charge, and an innovative 2D strip readout geometry is proposed. These improvements will allow iRPC detector to cope with higher background rates. A new Front-End-Board (FEB) is designed to readout iRPC signals with a threshold as low as 30fC and an integrated Time Digital Converter with a resolution of 30ps. In addition, the communication bandwidth is significantly increased by using optical fibers. The history, final design, certification, and calibration of this FEB are presented.
Improved resistive plate chambers for HL-LHC upgrade of CMS Samalan, A.; Thiel, M.; Asilar, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2024, Letnik:
1060, Številka:
C
Journal Article
Pressure correction study for the CMS iRPC detector Abdelhameid, T.; Gouzevitch, M.; Tytgat, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2024, Letnik:
1059, Številka:
C
Journal Article
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