Comparing Telerehabilitation and Home-based Exercise for Shoulder Disorders: A Systematic Review and Meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aimed to quantitatively compare the effects of telerehabilitation and home-based exercise for shoulder disorders. DATA SOURCES: We conducted a search for eligible studies in PubMed, EMBASE, Web of Science, Cochrane Library, and MEDLINE databases following Preferred Reporting Items for Systematic Review and Meta-analyses guidelines. STUDY SELECTION: Independent reviewers selected randomized controlled trials that compared the effects of telerehabilitation and home-based exercise in individuals with shoulder disorders. DATA EXTRACTION: Two reviewers independently conducted data extraction and assessed the risk of bias using the Cochrane Risk of Bias tool. DATA SYNTHESIS: A total of 7 studies with 508 participants were included. Compared with home-based exercise, telerehabilitation showed superior improvements in range of motion (flexion: standardized mean difference [SMD] 0.35, 95% confidence interval [CI] 0.14 to 0.56; abduction: SMD 0.37, 95% CI 0.16 to 0.58; external rotation: SMD 0.43, 95% CI 0.22 to 0.64; internal rotation: SMD 0.33, 95% CI 0.08 to 0.58), functional outcomes (Shoulder Pain and Disability Index: SMD -0.37, 95% CI -0.61 to -0.12; shortened Disabilities of the Arm, Shoulder and Hand questionnaire: mean difference [MD] -4.51, 95% CI -8.70 to -0.32), and quality of life (EuroQol Five Dimensions Questionnaire: MD 0.04, 95% CI 0.01 to 0.07). Telerehabilitation was not different from home-based exercise in terms of pain relief (SMD -0.19, 95% CI -0.60 to 0.23). Subgroup analysis demonstrated that telerehabilitation provided significant pain relief when sustained for over 12 weeks (SMD -0.46, 95% CI -0.81 to -0.11). CONCLUSIONS: Telerehabilitation is more effective than home-based exercise in improving range of motion, functional outcomes, and quality of life for patients with shoulder disorders. Telerehabilitation significantly outperforms home-based exercise in relieving pain when continued for over 12 weeks.

Caffeine intake enhances peak oxygen uptake and performance during high-intensity cycling exercise in moderate hypoxia.

PURPOSE: We investigated whether caffeine consumption can enhance peak oxygen uptake ([Formula: see text]) by increasing peak ventilation during an incremental cycling test, and subsequently enhance time to exhaustion (TTE) during high-intensity cycling exercise in moderate normobaric hypoxia. METHODS: We conducted a double-blind, placebo cross-over design study. Sixteen recreational male endurance athletes (age: 20 ± 2 years, [Formula: see text]: 55.6 ± 3.6 ml/kg/min, peak power output: 318 ± 40 W) underwent an incremental cycling test and a TTE test at 80% [Formula: see text] (derived from the placebo trial) in moderate normobaric hypoxia (fraction of inspired O2: 15.3 ± 0.2% corresponding to a simulated altitude of ~ 2500 m) after consuming either a moderate dose of caffeine (6 mg/kg) or a placebo. RESULTS: Caffeine consumption resulted in a higher peak ventilation [159 ± 21 vs. 150 ± 26 L/min; P < 0.05; effect size (ES) = 0.31]. [Formula: see text] (3.58 ± 0.44 vs. 3.47 ± 0.47 L/min; P < 0.01; ES = 0.44) and peak power output (308 ± 44 vs. 302 ± 44 W; P = 0.02, ES = 0.14) were higher following caffeine consumption than during the placebo trial. During the TTE test, caffeine consumption enhanced minute ventilation (P = 0.02; ES = 0.28) and extended the TTE (426 ± 74 vs. 358 ± 75 s; P < 0.01, ES = 0.91) compared to the placebo trial. There was a positive correlation between the percent increase of [Formula: see text] following caffeine consumption and the percent increase in TTE (r = 0.49, P < 0.05). CONCLUSION: Moderate caffeine consumption stimulates breathing and aerobic metabolism, resulting in improved performance during incremental and high-intensity endurance exercises in moderate normobaric hypoxia.

Automatic adjustment of cycle ergometer power output to accurately clamp heart rate.

We assessed the accuracy and inter-sessional reliability of traditional (manual) compared to automatic (AutoHR) heart rate (HR) clamping methods during submaximal intensity continuous cycling. On separate occasions, thirteen males cycled at an HR corresponding to 80% of the ventilatory threshold for 18 min. Cycling power output was adjusted using either manual or AutoHR methods, encompassing three trials per method. For the manual method, cycling power output was adjusted every 30 s by 0, 5 or 10 W at the experimenter's discretion. Conversely, AutoHR automatically adjusted power output based on the difference between target and actual HR. Participants' HR was measured at 1 Hz. Root-mean square error (RMSE) and intraclass correlation coefficients (ICC) were calculated from the difference between measured and target HR to represent accuracy and reliability of each method. The RMSE for the manual method (3.2 ± 2.6 bpm) was significantly higher compared to AutoHR (2.8 ± 2.3 bpm) (p < 0.01, r = 0.13); inter-day ICC were 0.92 and 0.89 for manual adjustment and AutoHR, respectively. Automatic methods to clamp HR are more accurate than manual approaches during submaximal intensity continuous cycling and can be easily implemented for uniform HR control in individual and group training sessions at minimal cost.

Recovery following exercise-induced fatigue: Influence of a single heart rate clamped cycling session under systemic hypoxia.

We investigated whether a single heart rate clamped cycling session under systemic hypoxia affects the recovery of physical and psycho-physiological responses from residual fatigue compared to normoxia. On separate occasions, twelve trained males performed a 3-d acute training camp scenario. On days 1 and 3, participants cycled for 60 min at a constant heart rate (80% of ventilatory threshold). On day 2, fatigue was induced through a simulated team game circuit (STGC), followed by a 60-min intervention of either: (1) heart rate clamped cycling in normoxia; (2) heart rate clamped cycling in hypoxia (simulated altitude ~ 3500 m); or (3) no cycling. Countermovement jump height and leg stiffness were assessed before and after every session. Perceptual fatigue was evaluated daily. Compared to baseline, jump height decreased at all timepoints following the STGC (all p < 0.05). Leg stiffness and cycling power output only decreased immediately following the STGC, with a 48% further decrease in cycling power output in hypoxia compared to normoxia (p < 0.05). Perceived fatigue, decreased sleep quality, and increased muscle soreness responses occurred on day 3 (p < 0.05). A single heart rate-clamped cycling session in hypoxia reduced mechanical output without affecting recovery of physical performance and perceptual measures from residual fatigue induced through team sport activity.

Manipulating Internal and External Loads During Repeated Cycling Sprints: A Comparison of Continuous and Intermittent Blood Flow Restriction.

ABSTRACT: Mckee, JR, Girard, O, Peiffer, JJ, and Scott, BR. Manipulating internal and external loads during repeated cycling sprints: A comparison of continuous and intermittent blood flow restriction. J Strength Cond Res 38(1): 47-54, 2024-This study examined the impact of blood flow restriction (BFR) application method (continuous vs. intermittent) during repeated-sprint exercise (RSE) on performance, physiological, and perceptual responses. Twelve adult male semi-professional Australian football players completed 4 RSE sessions (3 × [5 × 5-second maximal sprints:25-second passive recovery], 3-minute rest between the sets) with BFR applied continuously (C-BFR; excluding interset rest periods), intermittently during only sprints (I-BFR WORK ), or intraset rest periods (I-BFR REST ) or not at all (Non-BFR). An alpha level of p < 0.05 was used to determine significance. Mean power output was greater for Non-BFR ( p < 0.001, dz = 1.58 ), I-BFR WORK ( p = 0.002, dz = 0.63 ), and I-BFR REST ( p = 0.003, dz = 0.69 ) than for C-BFR and for Non-BFR ( p = 0.043, dz = 0.55 ) compared with I-BFR REST . Blood lactate concentration ( p = 0.166) did not differ between the conditions. Mean oxygen consumption was higher during Non-BFR ( p < 0.001, dz = 1.29 and 2.31; respectively) and I-BFR WORK ( p < 0.001, dz = 0.74 and 1.63; respectively) than during I-BFR REST and C-BFR and for I-BFR REST ( p = 0.002, dz = 0.57) compared with C-BFR. Ratings of perceived exertion were greater for I-BFR REST ( p = 0.042, dz = 0.51) and C-BFR ( p = 0.011, dz = 0.90) than for Non-BFR and during C-BFR ( p = 0.023, dz = 0.54) compared with I-BFR WORK . Applying C-BFR or I-BFR REST reduced mechanical output and cardiorespiratory demands of RSE and were perceived as more difficult. Practitioners should be aware that BFR application method influences internal and external demands during RSE.

A comparison of morning priming exercise using traditional-set and cluster-set configurations on afternoon explosive performance.

The impact of two priming exercise protocols using traditional (TS) or cluster-set (CS) arrangements on explosive performance 6 hours later were examined. Sixteen male collegiate athletes performed three testing sessions (one baseline without any prior exercise in the morning and two experimental sessions) separated by 72 hours. Participants completed two morning (9-11 am) priming protocols in a randomized order, either using a TS (no rest between repetitions) or CS (30 seconds of rest between repetitions) configuration. The protocols consisted of 3 sets × 3 repetitions of barbell back squat at 85% of 1 repetition maximum, with 4 minutes of rest between sets. In the afternoon (3-5 pm) of each trial, after a 6-hour rest period, a physical test battery was conducted that replicated baseline testing, including countermovement jump, 20-meter straight-line sprint, and T-test abilities. Across both conditions, participants exhibited increased countermovement jump height, 20-meter sprint time and T-test time compared to baseline (P < 0.05). Improvements in countermovement jump height (+4.4 ± 5.4%; P = 0.008) and 20-meter sprint time (+1.3 ± 1.7%; P = 0.022), but not T-test time (+1.1 ± 3.3%; P = 0.585), were significantly greater for CS than TS. In conclusion, compared to a traditional set arrangement, a morning-based priming protocol using a cluster-set configuration led to superior explosive performance benefits in the afternoon.

Mechanisms underlying the health benefits of intermittent hypoxia conditioning.

Intermittent hypoxia (IH) is commonly associated with pathological conditions, particularly obstructive sleep apnoea. However, IH is also increasingly used to enhance health and performance and is emerging as a potent non-pharmacological intervention against numerous diseases. Whether IH is detrimental or beneficial for health is largely determined by the intensity, duration, number and frequency of the hypoxic exposures and by the specific responses they engender. Adaptive responses to hypoxia protect from future hypoxic or ischaemic insults, improve cellular resilience and functions, and boost mental and physical performance. The cellular and systemic mechanisms producing these benefits are highly complex, and the failure of different components can shift long-term adaptation to maladaptation and the development of pathologies. Rather than discussing in detail the well-characterized individual responses and adaptations to IH, we here aim to summarize and integrate hypoxia-activated mechanisms into a holistic picture of the body's adaptive responses to hypoxia and specifically IH, and demonstrate how these mechanisms might be mobilized for their health benefits while minimizing the risks of hypoxia exposure.

Inhomogeneous Magnetization Transfer (ihMT) imaging in the acute cuprizone mouse model of demyelination/remyelination.

BACKGROUND: To investigate the association of ihMT (inhom signals with the demyelination and remyelination phases of the acute cuprizone mouse model in comparison with histology, and to assess the extent of tissue damage and repair from MRI data. METHODS: Acute demyelination by feeding 0.2% cuprizone for five weeks, followed by a four-week remyelination period was applied on genetically modified plp-GFP mice. Animals were scanned at different time points of the demyelination and remyelination phases of the cuprizone model using a multimodal MRI protocol, including ihMT T1D-filters, MPF (Macromolecular Proton Fraction) and R1 (longitudinal relaxation rate). For histology, plp-GFP (proteolipid protein - Green Fluorescent Protein) microscopy and LFB (Luxol Fast Blue) staining were employed as references for the myelin content. Comparison of MRI with histology was performed in the medial corpus callosum (mCC) and cerebral cortex (CTX) at two brain levels whereas ROI-wise and voxel-based analyses of the MRI metrics allowed investigating in vivo the spatial extent of myelin alterations. RESULTS: IhMT high-pass T1D-filters, targeted toward long T1D components, showed significant temporal variations in the mCC consistent with the effects induced by the cuprizone toxin. In addition, the corresponding signals correlated strongly and significantly with the myelin content assessed by GFP fluorescence and LFB staining over the demyelination and the remyelination phases. The signal of the band-pass T1D-filter, which isolates short T1D components, showed changes over time that were poorly correlated with histology, hence suggesting a sensitivity to pathological processes possibly not related to myelin. Although MPF was also highly correlated to histology, ihMT high-pass T1D-filters showed better capability to characterize the spatial-temporal patterns during the demyelination and remyelination phases of the acute cuprizone model (e.g., rostro-caudal gradient of demyelination in the mCC previously described in the literature). CONCLUSIONS: IhMT sequences selective for long T1D components are specific and sensitive in vivo markers of demyelination and remyelination and have successfully captured the spatially heterogeneous pattern of the demyelination and remyelination mechanisms in the cuprizone model. Interestingly, differences in signal variations between the ihMT high-pass and band-pass T1D-filter, suggest a sensitivity of the ihMT sequences targeted to short T1Ds to alterations other than those of myelin. Future studies will need to further address these differences by examining more closely the origin of the short T1D components and the variation of each T1D component in pathology.

Fast-spin-echo versus rapid gradient-echo for 3D magnetization-prepared acquisitions: Application to inhomogeneous magnetization transfer.

PURPOSE: To evaluate the benefits of fast spin echo (FSE) imaging over rapid gradient-echo (RAGE) for magnetization-prepared inhomogeneous magnetization transfer (ihMT) imaging. METHODS: A 3D FSE sequence was modified to include an ihMT preparation (ihMT-FSE) with an optional CSF suppression based on an inversion-recovery (ihMT-FLAIR). After numeric simulations assessing SNR benefits of FSE and the potential impact of an additional inversion-recovery, ihMT-RAGE, ihMT-FSE, and ihMT-FLAIR sequences were compared in a group of six healthy volunteers, evaluating image quality, thermal, and physiological noise as well as quantification using an ihMT saturation (ihMTsat) approach. A preliminary exploration in the cervical spinal cord was also conducted in a group of three healthy volunteers. RESULTS: Several fold improvements in thermal SNR were observed with ihMT-FSE in agreement with numerical simulations. However, we observed significantly higher physiological noise in ihMT-FSE compared to ihMT-RAGE that was mitigated in ihMT-FLAIR, which provided the best total SNR (+74% and +49% compared to ihMT-RAGE in the white and gray matter, P ≤ 0.004). IhMTsat quantification was successful in all cases with strong correlation between all sequences (r2 > 0.75). Early experiments showed potential for spinal cord imaging. CONCLUSIONS: FSE generally offers higher SNR compared to gradient-echo based acquisitions for magnetization-prepared contrasts as illustrated here in the case of ihMT. However, physiological noise has a significant effect, but an inversion-recovery-based CSF suppression was shown to be efficient in mitigating effects of CSF motion.

Quantitative magnetization transfer MRI unbiased by on-resonance saturation and dipolar order contributions.

PURPOSE: To demonstrate the bias in quantitative MT (qMT) measures introduced by the presence of dipolar order and on-resonance saturation (ONRS) effects using magnetization transfer (MT) spoiled gradient-recalled (SPGR) acquisitions, and propose changes to the acquisition and analysis strategies to remove these biases. METHODS: The proposed framework consists of SPGR sequences prepared with simultaneous dual-offset frequency-saturation pulses to cancel out dipolar order and associated relaxation (T1D ) effects in Z-spectrum acquisitions, and a matched quantitative MT (qMT) mathematical model that includes ONRS effects of readout pulses. Variable flip angle and MT data were fitted jointly to simultaneously estimate qMT parameters (macromolecular proton fraction [MPF], T2,f , T2,b , R, and free pool T1 ). This framework is compared with standard qMT and investigated in terms of reproducibility, and then further developed to follow a joint single-point qMT methodology for combined estimation of MPF and T1 . RESULTS: Bland-Altman analyses demonstrated a systematic underestimation of MPF (-2.5% and -1.3%, on average, in white and gray matter, respectively) and overestimation of T1 (47.1 ms and 38.6 ms, on average, in white and gray matter, respectively) if both ONRS and dipolar order effects are ignored. Reproducibility of the proposed framework is excellent (ΔMPF = -0.03% and ΔT1 = -19.0 ms). The single-point methodology yielded consistent MPF and T1 values with respective maximum relative average bias of -0.15% and -3.5 ms found in white matter. CONCLUSION: The influence of acquisition strategy and matched mathematical model with regard to ONRS and dipolar order effects in qMT-SPGR frameworks has been investigated. The proposed framework holds promise for improved accuracy with reproducibility.

Inhomogeneous magnetization transfer imaging: Concepts and directions for further development.

Off-resonance radio frequency irradiation can induce the ordering of proton spins in the dipolar fields of their neighbors, in molecules with restricted mobility. This dipolar order decays with a characteristic relaxation time, T1D , that is very different from the T1 and T2 relaxation of the nuclear alignment with the main magnetic field. Inhomogeneous magnetization transfer (ihMT) imaging is a refinement of magnetization transfer (MT) imaging that isolates the MT signal dependence on dipolar order relaxation times within motion-constrained molecules. Because T1D relaxation is a unique contrast mechanism, ihMT may enable improved characterization of tissue. Initial work has stressed the high correlation between ihMT signal and myelin density. Dipolar order relaxation appears to be much longer in membrane lipids than other molecules. Recent work has shown, however, that ihMT acquisitions may also be adjusted to emphasize different ranges of T1D . These newer approaches may be sensitive to other microstructural components of tissue. Here, we review the concepts and history of ihMT and outline the requirements for further development to realize its full potential.

Physiological characteristics and performance of a world-record breaking tower runner.

This study reports the physiological and performance profiles of a world-class tower runner during a 6-week period surrounding a successful Guinness World Record (WR) attempt, and discusses the efficacy of a tower running specific field test. The world-ranked number 2 tower runner completed four exercise tests [laboratory treadmill assessment (3 weeks before the WR attempt), familiarisation to a specific incremental tower running field test (1 week before), tower running field test (1 week after), and tower running time trial (TT) (3 weeks after)] and the WR attempt within 6-week period. Peak oxygen consumption (VO2peak) during the laboratory test, field test, and TT were 73.3, 75.5 and 78.3 mL·kg-1·min-1, respectively. The VO2 corresponding to the second ventilatory threshold was 67.3 mL·kg-1·min-1 (89.1% of VO2peak), identified at stage 4 (tempo; 100 b·min-1), during the field test. The duration of the TT was 10 min 50 s, with an average VO2 of 71.7 mL·kg-1·min-1 (91.6% of VO2peak), HR of 171 b·min-1 (92% of peak HR), vertical speed of 0.47 m·s-1, and cadence was 117 steps·min-1. A world-class tower runner possesses a well-developed aerobic capacity. A specific, field-based test revealed greater VO2peak than a laboratory test, indicating a need for sport-specific testing procedures.

From The Ground Up: Expert Perceptions of Lower Limb Activity Monitoring in Tennis.

Understanding on-court movement in tennis allows for enhanced preparation strategies to improve player readiness and performance. Here, we explore expert physical preparation coaches' perceptions of elite training strategies for preparation and performance in tennis, with special reference to lower limb activity. Thirteen world renowned tennis strength and conditioning coaches were interviewed in a semi-structured method that explored four key topic areas of physical preparation for tennis: i) the physical demands; ii) load monitoring practice; iii) the direction of ground reaction forces application during match-play; and iv) the application of strength and conditioning for tennis. Three higher-order themes emerged from these discussions: i) off-court training for tennis should be specific to the demands of the sport, ii) the mechanical understanding of tennis lags our physiological approach, and iii) our understanding of the lower limb's contribution to tennis performance is limited. These findings provide valuable insights into the importance of improving our knowledge relevant to the mechanical demands of tennis movement, whilst highlighting important practical considerations from leading tennis conditioning experts.

Automatic segmentation of deep grey nuclei using a high-resolution 7T magnetic resonance imaging atlas-Quantification of T1 values in healthy volunteers.

We present a new consensus atlas of deep grey nuclei obtained by shape-based averaging of manual segmentation of two experienced neuroradiologists and optimized from 7T MP2RAGE images acquired at (.6 mm)3 in 60 healthy subjects. A group-wise normalization method was used to build a high-contrast and high-resolution T1 -weighted brain template (.5 mm)3 using data from 30 out of the 60 controls. Delineation of 24 deep grey nuclei per hemisphere, including the claustrum and 12 thalamic nuclei, was then performed by two expert neuroradiologists and reviewed by a third neuroradiologist according to tissue contrast and external references based on the Morel atlas. Corresponding deep grey matter structures were also extracted from the Morel and CIT168 atlases. The data-derived, Morel and CIT168 atlases were all applied at the individual level using non-linear registration to fit the subject reference and to extract absolute mean quantitative T1 values derived from the 3D-MP2RAGE volumes, after correction for residual B1+ biases. Three metrics (the Dice and the volumetric similarity coefficients and a novel Hausdorff distance) were used to estimate the inter-rater agreement of manual MRI segmentation and inter-atlas variability, and these metrics were measured to quantify biases due to image registration, and their impact on the measurements of the quantitative T1 values was highlighted. This represents a fully automated segmentation process permitting the extraction of unbiased normative T1 values in a population of young healthy controls as a reference for characterizing subtle structural alterations of deep grey nuclei relevant to a range of neurological diseases.

A strategy to reduce the sensitivity of inhomogeneous magnetization transfer (ihMT) imaging to radiofrequency transmit field variations at 3 T.

PURPOSE: To minimize the sensitivity of inhomogeneous magnetization transfer gradient-echo (ihMT-GRE) imaging to radiofrequency (RF) transmit field ( B1+ ) inhomogeneities at 3 T. METHODS: The ihMT-GRE sequence was optimized by varying the concentration of the RF saturation energy over time, obtained by increasing the saturation pulse power while extending the sequence repetition time (TR). Different protocols were tested using numerical simulations and human in vivo experiments in the brain white matter (WM) of healthy subjects at 3 T. The sensitivity of the ihMT ratio (ihMTR) to B1+ variations was investigated by comparing measurements obtained at nominal transmitter adjustments and following a 20% global B1+ drop. The resulting relative variations (δihMTR ) were evaluated voxelwise as a function of the local B1+ distribution. The reproducibility of the protocol providing minimal B1+ bias was assessed in a test-retest experiment. RESULTS: In line with simulations, ihMT-GRE experiments conducted at high concentration of the RF energy over time demonstrated strong reduction of the B1+ inhomogeneity effects in the human WM. Under the optimal conditions of 350-ms TR and 3-µT root mean square (RMS) saturation power, 73% of all WM voxels presented δihMTR below 10%. Reproducibility analysis yielded a close-to-zero systematic bias (ΔihMTR = -0.081%) and a high correlation (ρ² = 0.977) between test and retest experiments. CONCLUSION: Concentrating RF saturation energy in ihMT-GRE sequences mitigates the sensitivity of the ihMTR to B1+ variations and allows for clinical-ready ihMT imaging at 3 T. This feature is of particular interest for high and ultra-high field applications.

T1D -weighted ihMT imaging - Part II. Investigating the long- and short-T1D components correlation with myelin content. Comparison with R1 and the macromolecular proton fraction.

PURPOSE: To investigate the long- and short-T1D components correlation with myelin content using inhomogeneous magnetization transfer (ihMT) high-pass and band-pass T1D -filters and to compare ihMT, R1 , and the macromolecular proton fraction (MPF) for myelin specific imaging. METHODS: The 3D ihMT rapid gradient echo (ihMTRAGE) sequences with increasing switching times (Δt) were used to derive ihMT high-pass T1D -filters with increasing T1D cutoff values and an ihMT band-pass T1D -filter for components in the 100 µs to 1 ms range. 3D spoiled gradient echo quantitative MT (SPGR-qMT) protocols were used to derive R1 and MPF maps. The specificity of R1 , MPF, and ihMT T1D -filters was evaluated by comparison with two histological reference techniques for myelin imaging. RESULTS: The higher contribution of long-T1D s as compared to the short components as Δt got longer led to an increase in the specificity to myelination. In contrast, focusing on the signal originating from a narrow range of short-T1D s (< 1 ms) as isolated by the band-pass T1D -filter led to lower specificity. In addition, the significantly lower r2 correlation coefficient of the band-pass T1D -filter suggests that the origin of short-T1D components is mostly associated with non-myelin protons. Also, the important contribution of short-T1D s to the estimated MPF, explains its low specificity to myelination as compared to the ihMT high-pass T1D -filters. CONCLUSION: Long-T1D components imaging by means of ihMT high-pass T1D -filters is proposed as an MRI biomarker for myelin content. Future studies should enable the investigation of the sensitivity of ihMT T1D -filters for demyelinating processes.

T1D -weighted ihMT imaging - Part I. Isolation of long- and short-T1D components by T1D -filtering.

PURPOSE: To identify T1D -filtering methods, which can specifically isolate various ranges of T1D components as they may be sensitive to different microstructural properties. METHODS: Modified Bloch-Provotorov equations describing a bi-T1D component biophysical model were used to simulate the inhomogeneous magnetization transfer (ihMT) signal from ihMTRAGE sequences at high RF power and low duty-cycle with different switching time values for the dual saturation experiment: Δt = 0.0, 0.8, 1.6, and 3.2 ms. Simulations were compared with experimental signals on the brain gray and white matter tissues of healthy mice at 7T. RESULTS: The lengthening of Δt created ihMT high-pass T1D -filters, which efficiently eliminated the signal from T1D components shorter than 1 ms, while partially attenuating that of longer components (≥ 1 ms). Subtraction of ihMTR images obtained with Δt = 0.0 ms and Δt = 0.8 ms generated a new ihMT band-pass T1D -filter isolating short-T1D components in the 100-µs to 1-ms range. Simulated ihMTR values in central nervous system tissues were confirmed experimentally. CONCLUSION: Long- and short-T1D components were successfully isolated with high RF power and low duty-cycle ihMT filters in the healthy mouse brain. Future studies should investigate the various T1D -range microstructural correlations in in vivo tissues.

Recovery of gold from e-waste via food waste byproducts.

Global materials' and energy constraints and environmental issues call for a holistic approach to waste upcycling. We propose a chemically rational, cost-effective and environmentally friendly recovery of non-leaching gold from e-waste using aqueous chemistry with hydrogen peroxide, an environmentally benign oxidant, and lactic acid, a food chain byproduct. The oxidation of the base metals enables the release of gold in its metallic state in the form of flakes subsequently separated via filtration. Our main byproduct is a precursor of Cu2O, a relevant metal oxide for solar energy conversion applications. The recovered gold was characterized by scanning electron microscopy, energy dispersive spectroscopy and x-ray photoelectron spectroscopy to gain insight into the morphology of the flakes and their chemical composition. Furthermore, recovered gold was used to successfully fabricate the source and drain electrodes in organic field-effect transistors.

Asymmetry in sprinting: An insight into sub-10 and sub-11 s men and women sprinters.

We assessed sprint mechanical asymmetry in world-class competitors and evaluated whether inter-limb sex-based differences in sprinting mechanics exist. The eight finalists in the men's and women's 100 m events at the 2017 IAAF World Championships were studied. Five high-speed cameras (150 Hz) were used to capture two consecutive steps of the whole body between 47.0 m and 55.5 m from the start, while four additional cameras (250 Hz) focussed on the lower extremities. A total of 33 spatio-temporal, touchdown and toe-off joint angles, and horizontal and vertical foot velocity parameters were extracted through three-dimensional analysis. Group mean asymmetry scores were assessed using the symmetry angle (SA) where scores of 0% and 100% represent perfect symmetry and perfect asymmetry, respectively. Although considered generally low (SA <3% for 22 out of 33 parameters), the magnitude of mechanical asymmetry varied widely between sprinters of the same sex. However, there was no mean SA scores difference between men and women for any stride mechanical parameters (all p ≥ 0.064). Asymmetry scores were inconsistent between parameters and phases (touchdown vs toe-off instants), and sprinting mechanics were generally not related to asymmetry magnitudes. In summary, low to moderate asymmetry is a natural phenomenon in elite sprinting. Asymmetry was inconsistent between parameters and competitors during near maximum velocity running, yet mean values for a given parameter generally did not differ between sexes. Sprinters' performances were not related to their SA scores.

Acute intense fatigue does not modify the effect of EVA and TPU custom foot orthoses on running mechanics, running economy and perceived comfort.

We determined whether fatigue modifies the effect of custom foot orthoses manufactured from ethyl-vinyl acetate (EVA) and expanded thermoplastic polyurethane (TPU) materials, both compared to standardized footwear (CON), on running mechanics, running economy, and perceived comfort. Eighteen well-trained, males ran on an instrumented treadmill for 6 min at the speed corresponding to their first ventilatory threshold (13.8 ± 1.1 km/h) in three footwear conditions (CON, EVA, and TPU). Immediately after completion of a repeated-sprints exercise (8 × 5 s treadmill sprints, rest = 25 s), these run tests were replicated. Running mechanics, running economy and perceived comfort were determined. Two-way repeated measures ANOVA [condition (CON, EVA, and TPU) × fatigue (fresh and fatigued)] were conducted. Flight time shortened (P = 0.026), peak braking (P = 0.016) and push-off (P = 0.032) forces decreased and vertical stiffness increased (P = 0.014) from before to after the repeated-sprint exercise, independent of footwear condition. There was a global fatigue-induced deterioration in running economy (- 1.6 ± 0.4%; P < 0.001). There was no significant condition × fatigue [except mean loading rate (P = 0.046)] for the large majority of biomechanical, cardio-respiratory [except minute ventilation (P = 0.020) and breathing frequency (P = 0.019)] and perceived comfort variables. Acute intense fatigue does not modify the effect of custom foot orthoses with different resilience characteristics on running mechanics, running economy and perceived comfort.