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Anthony W Baross,1 Jonathan D Wiles,2 Ian L Swaine21Sport and Exercise Science, University of Northampton, Northampton, UK; 2Sport and Exercise Science, Canterbury Christ Church University, Canterbury, Kent, UKAbstract: Double-leg isometric training has been demonstrated to reduce resting blood pressure in young men when using electromyographic activity (EMG) to regulate exercise intensity. This study assessed this training method in healthy older (45–60 years.) men. Initially, 35 older men performed an incremental isometric exercise test to determine the linearity of the heart rate versus percentage peak EMG (%EMGpeak) and systolic blood pressure versus %EMGpeak relationship. Thereafter, 20 participants were allocated to a training or control group. The training group performed three double-leg isometric sessions per week for 8 weeks, at 85% of peak heart rate. The training resulted in a significant reduction in resting systolic (11 ± 8 mmHg, P < 0.05) and mean arterial (5 ± 7 mmHg, P < 0.05) blood pressure. There was no significant change in resting systolic blood pressure for the control group or diastolic blood pressure in either group (all P > 0.05). These findings show that this training method, used previously in young men, is also effective in reducing resting systolic and mean arterial blood pressure in older men.Keywords: electromyography, resting blood pressure, heart rate

Abstract Adherence rates to current twice-weekly strength training guidelines are poor among older adults. Eccentric-only training elicits substantial improvements in muscle function/size so the aim of this study was to compare the effects of once- versus twice-weekly eccentric training programmes on muscle function/size in older adults. Thirty-six participants (69.4 ± 6.0 yr) were randomised into non-active control, once-, or twice-weekly training groups. Lower-limb muscle power, strength, and size were assessed at baseline, mid-, and post-eccentric training. Training was performed for 12 min per session at 50% of maximum eccentric strength. Significant increases in power (13%), isometric (17–36%) and eccentric (40–50%) strength, and VL muscle thickness (9–18%) occurred in both training groups following 12 weeks. Minimal muscle soreness was induced throughout the 12 weeks and perceived exertion was consistently lower in the twice-weekly training group. One weekly submaximal eccentric resistance training session over 12 weeks elicits similar improvements in neuromuscular function compared to the currently recommended twice-weekly training dose. Given the substantial improvements in neuromuscular function and previously reported low adherence to current twice-weekly training guidelines, eccentric training may be pivotal to developing a minimal-dose strategy to counteract neuromuscular decline. The trial was registered retrospectively on 24/01/2024 with ISRCTN (trial registration number: ISRCTN68730580).

Isometric resistance training (IRT) has emerged as an efficacious therapeutic intervention to reduce ambulatory blood pressure (BP), and BP diurnal variability. However, once the required decreases in BP have been achieved the efficacy of implementing a reduced maintenance dose is not understood. Therefore, the purpose of this study was to determine the effects of an 8-week maintenance period (8-week) following the cessation of the prescribed 8-week IRT in young normotensives. Twenty-two recreationally active, not resistance trained, normotensive (24-h ambulatory SBP, ≥130 mmHg) young adults were randomly assigned to a training-maintenance [TG-MT; n = 13 (female = 5); age 21 ± 2 years] or a non-training control [CON; n = 9 (female = 4); age 23 ± 3 years] group. Ambulatory BP, morning BP surge (MBPS) and average real variability (ARV) were measured prior to, after 8 weeks of bilateral leg IRT (4x2-minute contractions at 20% MVC with 2-min rest periods, 3 days/week) and following an 8-week (once per week) maintenance period. On completion of the maintenance period the significant reductions seen following the IRT were maintained within the TG-MT group in 24-h ambulatory SBP (6 ± 4 mmHg, p < 0.001), daytime (5 ± 5 mmHg, p = 0.002), MBPS (7 ± 10 mmHg, p = 0.019) and 24-h SBP ARV (2.03 ± 1.44 mmHg, p = 0.001), daytime SBP ARV (2.04 ± 1.78 mmHg, p = 0.003). These results show that reductions in ambulatory BP (24-h SBP and daytime SBP), in addition to BP diurnal variations (MBPS, 24-h SBP ARV and daytime SBP AVR) are maintained following an 8-week maintenance dose in young adults and add further weight to the growing body of evidence promoting IRT as an efficacious therapeutic exercise intervention to prevent or reduce BP.

ABSTRACT The importance of finite element analysis (FEA) is growing in orthopedic research, especially in implant design. However, Young's modulus (E) values, one of the most fundamental parameters, can range across a wide scale. Therefore, our study aimed to identify factors influencing E values in human bone specimens. We report our systematic review and meta‐analysis based on the recommendation of the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) 2020 guideline. We conducted the analysis on November 21, 2021. We included studies investigating healthy human bone specimens and reported on E values regarding demographic data, specimen characteristics, and measurement specifics. In addition, we included study types reporting individual specimen measurements. From the acquired data, we created a cohort in which we performed an exploratory data analysis that included the explanatory variables selected by random forest and regression trees methods, and the comparison of groups using independent samples Welch's t test. A total of 756 entries were included from 48 articles. Eleven different bones of the human body were included in these articles. The range of E values is between 0.008 and 33.7 GPa. The E values were most heavily influenced by the cortical or cancellous type of bone tested. Measuring method (compression, tension, bending, and nanoindentation), the anatomical region within a bone, the position of the bone within the skeleton, and the bone specimen size had a decreasing impact on the E values. Bone anisotropy, specimen condition, patient age, and sex were selected as important variables considering the value of E. On the basis of our results, E values of a bone change with bone characteristics, measurement techniques, and demographic variables. Therefore, the evaluation of FEA should be performed after the standardization of in vitro measurement protocol. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Abstract Background Array genomic hybridization is being used clinically to detect pathogenic copy number variants in children with intellectual disability and other birth defects. However, there is no agreement regarding the kind of array, the distribution of probes across the genome, or the resolution that is most appropriate for clinical use. Results We performed 500 K Affymetrix GeneChip® array genomic hybridization in 100 idiopathic intellectual disability trios, each comprised of a child with intellectual disability of unknown cause and both unaffected parents. We found pathogenic genomic imbalance in 16 of these 100 individuals with idiopathic intellectual disability. In comparison, we had found pathogenic genomic imbalance in 11 of 100 children with idiopathic intellectual disability in a previous cohort who had been studied by 100 K GeneChip® array genomic hybridization. Among 54 intellectual disability trios selected from the previous cohort who were re-tested with 500 K GeneChip® array genomic hybridization, we identified all 10 previously-detected pathogenic genomic alterations and at least one additional pathogenic copy number variant that had not been detected with 100 K GeneChip® array genomic hybridization. Many benign copy number variants, including one that was de novo, were also detected with 500 K array genomic hybridization, but it was possible to distinguish the benign and pathogenic copy number variants with confidence in all but 3 (1.9%) of the 154 intellectual disability trios studied. Conclusion Affymetrix GeneChip® 500 K array genomic hybridization detected pathogenic genomic imbalance in 10 of 10 patients with idiopathic developmental disability in whom 100 K GeneChip® array genomic hybridization had found genomic imbalance, 1 of 44 patients in whom 100 K GeneChip® array genomic hybridization had found no abnormality, and 16 of 100 patients who had not previously been tested. Effective clinical interpretation of these studies requires considerable skill and experience.

Abstract Background Genomic deletions and duplications are important in the pathogenesis of diseases, such as cancer and mental retardation, and have recently been shown to occur frequently in unaffected individuals as polymorphisms. Affymetrix GeneChip whole genome sampling analysis (WGSA) combined with 100 K single nucleotide polymorphism (SNP) genotyping arrays is one of several microarray-based approaches that are now being used to detect such structural genomic changes. The popularity of this technology and its associated open source data format have resulted in the development of an increasing number of software packages for the analysis of copy number changes using these SNP arrays. Results We evaluated four publicly available software packages for high throughput copy number analysis using synthetic and empirical 100 K SNP array data sets, the latter obtained from 107 mental retardation (MR) patients and their unaffected parents and siblings. We evaluated the software with regards to overall suitability for high-throughput 100 K SNP array data analysis, as well as effectiveness of normalization, scaling with various reference sets and feature extraction, as well as true and false positive rates of genomic copy number variant (CNV) detection. Conclusion We observed considerable variation among the numbers and types of candidate CNVs detected by different analysis approaches, and found that multiple programs were needed to find all real aberrations in our test set. The frequency of false positive deletions was substantial, but could be greatly reduced by using the SNP genotype information to confirm loss of heterozygosity.

The aim of this work is to investigate the bonding properties of the ceramic dispersion-strengthened 316L (CDS-316L) composites with the reference 316L stainless steel (REF-316L) using a Gleeble 3800 physical simulator. In previous works, two different composites, REF-316L and 316L, with 1 wt% Al2O3 composite (CDS-316L) have been prepared by spark plasma sintering (SPS). In the present work, these specimens were diffusion-bonded using the following parameters: a temperature range of 950–1000 °C and a uniaxial pressure of 20–30 MPa. It was observed that the deformation of the CDS-316L during the uniaxial bonding process was higher compared to the 316L steel rods. The addition of alumina particles increased the micro-hardness of the 316L steel. The samples were broken in the CDS-316L zones, not at the diffusion-bonded interfaces. No diffusion zones have been observed within the investigated magnification for all composites, where the interfaces between the different specimens were well defined.

Abstract Adults with congenital heart disease (CHD) face increased risk of various comorbid diseases. Previous work on lung dysfunction in this population has mainly focused on restrictive lung disease, in patients with severe CHD phenotypes. We examined the association of mild CHD with chronic obstructive pulmonary disease (COPD) in the UK Biobank (UKB). Electronic health records (EHR) were used to identify 3385 CHD cases and 479,765 healthy controls in UKB, before performing a case–control analysis over a 20-year study period for a total of > 9.5 M person-years of follow-up. Our analysis showed that UKB participants with CHD are at substantially greater risk of developing COPD than healthy controls (8.7% vs 3.1% prevalence, unadjusted OR 2.98, 95% CI 2.63, 3.36, P = 1.40e−53). Slightly increased rates of smoking were observed amongst CHD cases, however the association with COPD was shown to be robust to adjustment for smoking and other factors known to modulate COPD risk within a multivariable-adjusted Cox regression framework (fully adjusted HR 2.21, 95% CI 1.97, 2.48, P = 5.5e−41). Care for adults with CHD should aim to mitigate their increased risk of COPD, possibly via increased smoking cessation support.

Abstract Despite the reported association between diurnal variations in ambulatory blood pressure (BP) and elevated cardiovascular disease risk, little is known regarding the effects of isometric resistance training (IRT), a practical BP-lowering intervention, on ambulatory BP and morning BP surge (MBPS). Thus, we investigated whether (i) IRT causes reductions in ambulatory BP and MBPS, in young normotensives, and (ii) if there are any sex differences in these changes. Twenty normotensive individuals (mean 24-h SBP = 121 ± 7, DBP = 67 ± 6 mmHg) undertook 10-weeks of bilateral-leg IRT (4 × 2-min/2-min rest, at 20% maximum voluntary contraction (MVC) 3 days/week). Ambulatory BP and MBPS (mean systolic BP (SBP) 2 h after waking minus the lowest sleeping 1 h mean SBP) was measures pre- and post-training. There were significant reductions in 24-h ambulatory SBP in men (− 4 ± 2 mmHg, P = 0.0001) and women (− 4 ± 2 mmHg, P = 0.0001) following IRT. Significant reductions were also observed in MBPS (− 6 ± 8 mmHg, p = 0.044; − 6 ± 7 mmHg, P = 0.019), yet there were no significant differences between men and women in these changes, and 24-h ambulatory diastolic BP remained unchanged. Furthermore, a significant correlation was identified between the magnitude of the change in MBPS and the magnitude of changes in the mean 2-h SBP after waking for both men and women (men, r = 0.89, P = 0.001; women, r = 0.74, P = 0.014). These findings add further support to the idea that IRT, as practical lifestyle intervention, is effective in significantly lowering ambulatory SBP and MBPS and might reduce the incidence of adverse cardiovascular events that often occur in the morning.

Despite several established benefits of Whole Body Cryotherapy (WBC) for post-exercise recovery, there is a scarcity of research which has identified the optimum WBC protocol for this purpose. This study investigated the influence of WBC treatment timing on physiological and functional responses following a downhill running bout. An additional purpose was to compare such responses with those following cold water immersion (CWI), since there is no clear consensus as to which cold modality is more effective for supporting athletic recovery. Thirty-three male participants (mean ± SD age 37.0 ± 13.3 years, height 1.76 ± 0.07 m, body mass 79.5 ± 13.7 kg) completed a 30 min downhill run (15% gradient) at 60% VO2 max and were then allocated into one of four recovery groups: WBC1 (n = 9) and WBC4 (n = 8) underwent cryotherapy (3 min, −120°C) 1 and 4 h post-run, respectively; CWI (n = 8) participants were immersed in cold water (10 min, 15°C) up to the waist 1 h post-run and control (CON, n = 8) participants passively recovered in a controlled environment (20°C). Maximal isometric leg muscle torque was assessed pre and 24 h post-run. Blood creatine kinase (CK), muscle soreness, femoral artery blood flow, plasma IL-6 and sleep were also assessed pre and post-treatment. There were significant decreases in muscle torque for WBC4 (10.9%, p = 0.04) and CON (11.3% p = 0.00) and no significant decreases for WBC1 (5.6%, p = 0.06) and CWI (5.1%, p = 0.15). There were no significant differences between groups in muscle soreness, CK, IL-6 or sleep. Femoral artery blood flow significantly decreased in CWI (p = 0.02), but did not differ in other groups. WBC treatments within an hour may be preferable for muscle strength recovery compared to delayed treatments; however WBC appears to be no more effective than CWI. Neither cold intervention had an impact on inflammation or sleep.

Isometric resistance training (IRT) has emerged as an efficacious therapeutic intervention to reduce ambulatory blood pressure (BP), and BP diurnal variability. However, once the required decreases in BP have been achieved the efficacy of implementing a reduced maintenance dose is not understood. Therefore, the purpose of this study was to determine the effects of an 8-week maintenance period (8-week) following the cessation of the prescribed 8-week IRT in young normotensives. Twenty-two recreationally active, not resistance trained, normotensive (24-h ambulatory SBP, ≥130 mmHg) young adults were randomly assigned to a training-maintenance [TG-MT; n = 13 (female = 5); age 21 ± 2 years] or a non-training control [CON; n = 9 (female = 4); age 23 ± 3 years] group. Ambulatory BP, morning BP surge (MBPS) and average real variability (ARV) were measured prior to, after 8 weeks of bilateral leg IRT (4x2-minute contractions at 20% MVC with 2-min rest periods, 3 days/week) and following an 8-week (once per week) maintenance period. On completion of the maintenance period the significant reductions seen following the IRT were maintained within the TG-MT group in 24-h ambulatory SBP (6 ± 4 mmHg, p < 0.001), daytime (5 ± 5 mmHg, p = 0.002), MBPS (7 ± 10 mmHg, p = 0.019) and 24-h SBP ARV (2.03 ± 1.44 mmHg, p = 0.001), daytime SBP ARV (2.04 ± 1.78 mmHg, p = 0.003). These results show that reductions in ambulatory BP (24-h SBP and daytime SBP), in addition to BP diurnal variations (MBPS, 24-h SBP ARV and daytime SBP AVR) are maintained following an 8-week maintenance dose in young adults and add further weight to the growing body of evidence promoting IRT as an efficacious therapeutic exercise intervention to prevent or reduce BP. [ABSTRACT FROM AUTHOR]

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The aim of this work is to investigate the bonding properties of the ceramic dispersion-strengthened 316L (CDS-316L) composites with the reference 316L stainless steel (REF-316L) using a Gleeble 3800 physical simulator. In previous works, two different composites, REF-316L and 316L, with 1 wt% Al2O3 composite (CDS-316L) have been prepared by spark plasma sintering (SPS). In the present work, these specimens were diffusion-bonded using the following parameters: a temperature range of 950–1000 °C and a uniaxial pressure of 20–30 MPa. It was observed that the deformation of the CDS-316L during the uniaxial bonding process was higher compared to the 316L steel rods. The addition of alumina particles increased the micro-hardness of the 316L steel. The samples were broken in the CDS-316L zones, not at the diffusion-bonded interfaces. No diffusion zones have been observed within the investigated magnification for all composites, where the interfaces between the different specimens were well defined. [ABSTRACT FROM AUTHOR]

The purpose of the study was to investigate the effects of an 11-week unilateral versus bilateral plyometric training intervention on maximal isometric voluntary (MVC) knee extensor torque, countermovement jump height (CMJ), running economy (RE) and 3-km time trial (TT) performance. Twenty-seven recreationally trained endurance runners (12 females and 15 males) were randomly assigned to one of three groups: unilateral plyometric training (UPT; n = 9), bilateral plyometric training (BPT; n = 9) and control (CON; n = 9). RE, VO2max, 3-km treadmill TT, isometric MVC (bilateral and unilateral) and CMJ (bilateral and unilateral) were measured prior to and after 11 weeks of training (UPT and BPT; volume equated, 20-40 minutes, 2-3 days/week). Separate two-way repeated measures ANOVAs were used to assess within and between group differences in RE, VO2max, 3-km TT, maximal isometric knee extensor torque and CMJ. Following 11 weeks of plyometric training there were significant improvements in RE (UPT 5.6%; BPT 4.9%, p < 0.01) and 3-km TT performance (UPT 2.4%; BPT 2.5%, p < 0.01) in addition to CMJ (UPT 12.5%; BPT 14.5%, p < 0.01) and maximal isometric knee extensor torque in the unilateral group (14.0%, p < 0.01). No significant differences in VO2max or anthropometric measures were detected (p > 0.05). No statistically significant differences between training interventions (p > 0.05) were detected in any measure. These data demonstrate that UPT and BPT result in similar improvements in RE and 3-km TT run performance in recreational distance runners.

Human embryonic stem cell-derived cardiomyocytes (hESC-CM) are a widely used model to study cardiac genomics. Here, Choy et al. perform promoter capture Hi-C to map long-range chromosomal interactions of hESC-CMs and to study overlap of such regions with genetic loci associated with cardiac phenotypes.