Development of Robust PEBAX-Based Angiographic Catheter: Design and In Vitro Study.

BACKGROUND: Keeping in mind the unceasingly escalating prevalence of coronary disease worldwide, the mortality rate is also expected to rise with a staggering increase in healthcare costs. Angiography is the gold standard for diagnosing these blockages that trigger these diseases. Amides and urethanes are the common catheter construction material used for angiography. However, the experimental evidence verifying the use of PEBAX® and comparing its performance with that of commercially available catheters for angiography is not published despite it being well recognized for its excellent flexural modulus, mechanical properties, and biocompatibility and its potential to reduce the incidence of vascular spasm during intravascular diagnostic and interventional procedures. Therefore, the aim of this study was to develop a PEBAX®-based angiographic catheter and evaluate its performance in comparison with three commercially available nylon- and polyurethane-based angiographic catheters. METHODOLOGY: A PEBAX®-based angiographic catheter was developed for this purpose. This study analyzes and reports the performance and behavior of PEBAX®-, nylon-, and polyurethane-based catheters. The catheter's performance and arterial forces' endurance nature were mapped out by evaluating pushability (advancement force) and selective bench tests outlined in the applicable regulatory standard. CONCLUSIONS: The PEBAX®-based catheter exhibited the least bond-flexural rigidity (180.4 g), which was approximately one-third of that shown by all six French catheters and which exhibited the least advancement force (510.4 g), which was approximately 50% less than that of the nylon- and polyurethane-based catheters when traversing through the mock arterial system. Bench testing was carried out as per the applicable regulatory standard; the differences obtained between individual catheters were discussed in detail. Based on this extensive in vitro assessment, it was concluded that the PEBAX®-based catheters outperformed the nylon- and polyurethane-based catheters, exhibiting an exceptionally minimal advancement force of 510.4 g. This leads to the inference that this catheter can inject more radiopaque material (because of the enhanced flow rate) to the coronary arteries and can play a significant role in minimizing vascular spasms during a diagnostic procedure.

A survey of gamma camera and SPECT/CT quality control programs across a sample of public hospitals in Australia.

Performance testing of gamma cameras and single photon computed tomography/computed tomography (SPECT/CT) systems is not subject to regulatory requirements across states and territories in Australia. Internationally recognised testing standards from organisations such as the National Electrical Manufacturers Association (NEMA) describe methodologies for recommended tests. However, variations exist in suggested quality control (QC) schedules from professional bodies such as the Australia and New Zealand Society of Nuclear Medicine (ANZSNM). In this study, a survey was conducted to benchmark current QC programs across a selected sample of eight standalone and networked Australian public hospitals. Vendor-specific flood-field uniformity (intrinsic or extrinsic/system) verification without photomultiplier (PMT) tuning and CT QC were performed at all sites. Weekly and monthly PMT tuning followed by intrinsic flood-field verifications were performed at most sites. At least half of the sites performed monthly centre of rotation (COR) offset verifications. SPECT/CT alignment calibrations and verifications were undertaken by service engineers at all sites, and periodic verifications were performed by local staff at varying frequencies. Variations were observed for other periodic QC tests such as spatial resolution and planar sensitivity. Similarly, variations were observed for tests specific to whole-body systems and SPECT systems. Most sites checked daily and periodic QC results against pass/fail criteria set by vendors. Additional analyses of the QC results, including trend analysis and periodic reviews, were not common practice. The lack of regulatory requirements is likely to have led to variations in QC tests that are generally either harder to perform or are more labour intensive.

Revisiting the stretch-induced force deficit: A systematic review with multilevel meta-analysis of acute effects.

BACKGROUND: When recommending avoidance of static stretching prior to athletic performance, authors and practitioners commonly refer to available systematic reviews. However, effect sizes (ES) in previous reviews were extracted in major part from studies lacking control conditions and/or pre-post testing designs. Also, currently available reviews conducted calculations without accounting for multiple study outcomes, with ES: -0.03 to 0.10, which would commonly be classified as trivial. METHODS: Since new meta-analytical software and controlled research articles have appeared since 2013, we revisited the available literatures and performed a multilevel meta-analysis using robust variance estimation of controlled pre-post trials to provide updated evidence. Furthermore, previous research described reduced electromyography activity-also attributable to fatiguing training routines-as being responsible for decreased subsequent performance. The second part of this study opposed stretching and alternative interventions sufficient to induce general fatigue to examine whether static stretching induces higher performance losses compared to other exercise routines. RESULTS: Including 83 studies with more than 400 ES from 2012 participants, our results indicate a significant, small ES for a static stretch-induced maximal strength loss (ES = -0.21, p = 0.003), with high magnitude ES (ES = -0.84, p = 0.004) for stretching durations ≥60 s per bout when compared to passive controls. When opposed to active controls, the maximal strength loss ranges between ES: -0.17 to -0.28, p < 0.001 and 0.040 with mostly no to small heterogeneity. However, stretching did not negatively influence athletic performance in general (when compared to both passive and active controls); in fact, a positive effect on subsequent jumping performance (ES = 0.15, p = 0.006) was found in adults. CONCLUSION: Regarding strength testing of isolated muscles (e.g., leg extensions or calf raises), our results confirm previous findings. Nevertheless, since no (or even positive) effects could be found for athletic performance, our results do not support previous recommendations to exclude static stretching from warm-up routines prior to, for example, jumping or sprinting.

Are Functional Performance Test Scores Better When Compared to Baseline or Contralateral Limb Scores Following LE Injury in Adolescent Athletes?

Background: Functional performance tests (FPT) have been used with athletes following an injury to determine readiness to return-to-play (RTP), usually using limb symmetry indices to the contralateral limb or a baseline score. There is not a consensus as to which criterion scores are best compared. Hypothesis/Purpose: This study aimed to compare common functional performance test scores from injured athletes at the time of release to RTP to both preseason baseline scores and to the contralateral limb. It was hypothesized that using baseline scores for comparison would be more responsive to residual deficits following injury than using the contralateral limb. Study Design: Prospective longitudinal cohort study. Methods: High school athletes (n=395) from all varsity sports completed a battery of FPTs including the Y-Balance Test (YBT), single limb hop tests and T-Test for agility (TT) during their preseason to establish baseline data. Injured athletes (n=19) were re-tested using all FTP's again at the time of RTP. Paired t-tests were used to detect if significant (p\<0.05) residual deficits were present at time of RTP when compared to baseline and to contralateral scores on FPTs. Results: Differences in YBT scores were found in the anterior direction only (p=0.021) when comparing RTP to preseason, but there were no differences when compared to RTP data for the contralateral limb. Differences were detected with the single leg hop test (p = 0.001) when comparing the RTP to preseason and were also detected in both the single leg hop (p= 0.001) and triple hop (p=0.018) when compared to the contralateral limb. Differences in TT scores were detected when comparing RTP to preseason for cutting first with both the unaffected (p = 0.019) and affected (p = 0.014) limbs. Conclusions: The YBT in the anterior direction and the TT are better able to detect residual deficits when comparing RTP to preseason scores. Hop tests are better able to detect deficits when compared to the contralateral limb. These results could make preseason testing more efficient when creating a reference for determining RTP readiness following lower extremity injury.

Developing a hetero-intelligence methodological framework for sustainable policy-making based on the assessment of large language models.

This work delves into the increasing relevance of Large Language Models (LLMs) in the realm of sustainable policy-making, proposing an innovative hetero-intelligence framework that blends human and artificial intelligence (AI) for tackling modern sustainability challenges. The research methodology includes a hetero-intelligence performance test, which juxtaposes human intelligence with AI in the formulation and implementation of sustainable policies. After testing this hetero-intelligence methodology, seven steps are rigorously described so that it can be replicated in any sustainability planning related context. The results underscore the capabilities and limitations of LLMs, underscoring the critical role of human intelligence in enhancing the efficacy of hetero-intelligence systems. This work fulfils the need of a rigorous methodological framework based on empirical steps that can provide unbiased outcomes to be integrated into sustainable planning and decision-making processes.•Assesses LLMs' limitations and capabilities regarding sustainable planning issues•A replicable methodology is proposed based on the combination of both human and artificial intelligence•It proposes and systematises the integration of a hetero-intelligent approach into the formulation of sustainability policies to be more efficient and effective.

Metabolic, cognitive and neuromuscular responses to different multidirectional agility-like sprint protocols in elite female soccer players - a randomised crossover study.

PURPOSE: Resistance to fatigue is a key factor in injury prevention that needs to be considered in return-to-sport (RTS) scenarios, especially after severe knee ligament injuries. Fatigue should be induced under game-like conditions. The SpeedCourt (SC) is a movement platform for assessing multidirectional sprint performance, typical of game-sports, due to change-of-direction movements in response to a visual stimulus. Designing adequate fatigue protocols requires the suitable arrangement of several loading variables such as number of intervals, sprint distance or work/relief ratio (W:R). Therefore, this study analysed the acute fatigue effects of different SC protocols on metabolic load, cognitive function and neuromuscular performance. METHODS: Eighteen female soccer players (mean ± SD; age: 23.1 ± 4.6 years) of the 1st German Division participated in this randomised, crossover study. Using a random allocation sequence, players completed four volume-equated protocols differing in W:R and sprint distance per interval (P1:12 × 30 m, W:R = 1:2 s; P2:12 × 30 m, W:R = 1:3 s; P3:18 × 20 m, W:R = 1:2 s; P4:18 × 20 m, W:R = 1:3 s). Pre- and post-exercise, metabolic load was measured per blood lactate concentration (BLaC), cognitive function per reaction time (RT), and neuromuscular performance including multiple rebound jumps (MRJ height, primary outcome variable; Reactive Strength Index, RSI) and 5 m sprint times (SP5). RESULTS: Repeated-measures ANOVA revealed significant main time effects (p < .05) with improved performance post-exercise in RT (504 vs. 482 ms, d = 1.95), MRJ height (24.0 vs. 24.8 cm, d = 0.77), RSI (1.39 vs. 1.43, d = 0.52), and SP5 (1.19 vs. 1.17 s, d = 0.56). There was significant main time (p < .001) and time x protocol interaction effects in BLaC (p < .001). P1 induced higher BLaC values (4.52 ± 1.83 mmol/L) compared to P2 (3.79 ± 1.83 mmol/L; d = 0.74) and P4 (3.12 ± 1.83 mmol/L; d = 1.06), whereas P3 (4.23 ± 1.69 mmol/L) elicited higher BLaC values compared to P4 (d = 0.74). CONCLUSION: All protocols caused an improved cognitive function and neuromuscular performance. The former may be related to enhanced noradrenergic activation or exercise specificity which induced an improved stimulus processing. The latter may be explained by a possible post-activation performance enhancement effect on jump and sprint performance. A shorter relief duration in W:R as opposed to sprint distance per interval produced higher BLaC values. The protocols may serve as reference data for improved RTS decision-making in elite female soccer players. TRIAL REGISTRATION: Deutsches Register Klinischer Studien (DRKS), No.: DRKS00033496 , Registered 19. Februar 2024, Retrospectively Registered.

Validity and Reliability of Finger-Strength Testing in 6 Common Grip Techniques for the Assessment of Bouldering Ability in Men.

OBJECTIVE: To determine the criterion validity and test-retest reliability of isometric finger-strength testing in 6 differentiated grip techniques for the assessment of bouldering ability among male climbers. METHODS: We recruited participants at climbing gyms in Sweden and through online advertisements. We included climbers over 15 years of age with a minimum bouldering performance level of 17 International Rock Climbing and Research Association (IRCRA) for men and 15 IRCRA for women. We tested unilateral, maximal isometric peak finger strength in the front 3 drag, half crimp, closed crimp, 35 sloper, 45 × 90-mm, and 90 × 90-mm pinch through maximal force deloaded of a force plate. We analyzed criterion validity, test-retest reliability, and capacity to determine bouldering performance ability using a stepwise multivariable regression model. RESULTS: Women were excluded from the analysis due to insufficient sample size (n = 16). Thirty-two male participants were included in the primary analysis. The median (interquartile range) age in the advanced and elite group was 27 (25; 35) and 23 (22; 32) years, respectively. The half crimp for the participants' weak and strong hand displayed the highest ability to determine bouldering grade performance, explaining 48% to 58% of the variance. In the stepwise regression, maximal strength in the half crimp and the front 3 drag collectively explained 66% of the variance for performance. CONCLUSION: Strength in the half crimp proved the most important performance indicator. The results of this study provide a reliable and valid framework for maximal isometric peak finger-strength testing in advanced and elite male boulderers.

Effects of Age and Playing Position on Field-Based Physical Fitness Measures in Adolescent Female Netball Players.

This cross-sectional study investigated the impact of age and playing position, controlling for maturity, on physical fitness indicators in 303 adolescent female netball players aged 12.0 to 15.9 years. Assessments included estimated maximal oxygen uptake (VO2max) via the 20 m shuttle run test, 10 m and 20 m sprints, change of direction speed (CODS) using the 505 test, and muscle power via the medicine ball chest throw (MBCT) and countermovement vertical jump (CMJ). Participants were grouped by age (12 to 15 years) and playing position (non-circle and circle players), with age at peak height velocity as a covariate for maturity. Results revealed that, at 15 years, CMJ height was greater than at 12 years and 13 years (p < 0.05, partial η2 = 0.048). MBCT distance increased across age groups (p < 0.01, partial η2 = 0.323). Age had no impact on sprints, VO2max, or CODS. Non-circle players outperformed circle players in the 10 m sprint (p = 0.042, partial η2 = 0.016) and 20 m sprints (p = 0.010, partial η2 = 0.025) and displayed higher VO2max (p < 0.001, partial η2 = 0.036). Circle players were taller (p = 0.046, partial η2 = 0.014) and heavier (p < 0.001, partial η2 = 0.040) than non-circle players. Playing positions showed no differences in CMJ and MBCT. In adolescent female netball players, only muscle power is influenced by age, while non-circle players exhibit superior aerobic fitness and speed compared to circle players. Coaches may be able to utilize the distinct age and playing position traits of adolescent netballers to inform player selection and design targeted training programs.

Design and implementation of mechanical property testing equipment for thoracic aortic stent grafts.

The mechanical properties of the stent graft are important factors influencing the outcome of TEVAR treatment and the occurrence of postoperative complications. The aim of this study is to improve and design a mechanical performance testing equipment for thoracic aortic stent grafts. The mechanical performance testing equipment consists of a radial force testing equipment of the stent graft designed by the wire compression grip method and a dynamic straightening force testing device with stable and controllable test conditions and continuously variable test angles. By constructing the testing equipment to physically measure the stent specimen, the experimental results reflect the trend of change and the simulation results are basically consistent, i.e. the mechanical properties of the thoracic aortic stent designed in this study is feasible and the measured data are valid. The testing equipment can provide the basis and reference direction for the quality testing of stent graft products, optimisation of mechanical properties of stent grafts and R&D innovation.

Heart Rate Variability-Derived Thresholds for Exercise Intensity Prescription in Endurance Sports: A Systematic Review of Interrelations and Agreement with Different Ventilatory and Blood Lactate Thresholds.

BACKGROUND: Exercise intensities are prescribed using specific intensity zones (moderate, heavy, and severe) determined by a 'lower' and a 'higher' threshold. Typically, ventilatory (VT) or blood lactate thresholds (LT), and critical power/speed concepts (CP/CS) are used. Various heart rate variability-derived thresholds (HRVTs) using different HRV indices may constitute applicable alternatives, but a systematic review of the proximity of HRVTs to established threshold concepts is lacking. OBJECTIVE: This systematic review aims to provide an overview of studies that determined HRVTs during endurance exercise in healthy adults in comparison with a reference VT and/or LT concept. METHODS: A systematic literature search for studies determining HRVTs in healthy individuals during endurance exercise and comparing them with VTs or LTs was conducted in Scopus, PubMed and Web of Science (until January 2022). Studies claiming to describe similar physiological boundaries to delineate moderate from heavy (HRVTlow vs. VTlow and/or LTlow), and heavy from severe intensity zone (HRVThigh vs. VThigh and/or LThigh) were grouped and their results synthesized. RESULTS: Twenty-seven included studies (461 participants) showed a mean difference in relative HR between HRVTlow and VTlow of - 0.6%bpm in weighted means and 0.02%bpm between HRVTlow and LTlow. Bias between HR at HRVTlow and VTlow was 1 bpm (limits of agreement (LoA): - 10.9 to 12.8 bpm) and 2.7 bpm (LoA: - 20.4 to 25.8 bpm) between HRVTlow and LTlow. Mean difference in HR between HRVThigh and VThigh was 0.3%bpm in weighted means and 2.9%bpm between HRVThigh and LThigh while bias between HR at HRVThigh and VThigh was - 4 bpm (LoA: - 17.9 to 9.9 bpm) and 2.5 bpm (LoA: - 12.1 to 17.1 bpm) between HRVThigh and LThigh. CONCLUSION: HRVTlow seems to be a promising approach for the determination of a 'lower' threshold comparable to VTlow and potentially for HRVThigh compared to VThigh, although the latter needs further empirical evaluation. LoA for both intensity zone boundaries indicates bias of HRVTs on an individual level. Taken together, HRVTs can be a promising alternative for prescribing exercise intensity in healthy, male athletes undertaking endurance activities but due to the heterogeneity of study design, threshold concepts, standardization, and lack of female participants, further research is necessary to draw more robust and nuanced conclusions.