Changes in the force-time curve during a repeat power ability assessment using loaded countermovement jumps
Background Repeat power ability (RPA) assessments traditionally use discrete variables, such as peak power output, to quantify the change in performance across a series of jumps. Rather than using a discrete variable, the analysis of the entire force-time curve may provide additional insight into RPA performance. The aims of this study were to (1) analyse changes in the force-time curve recorded during an RPA assessment using statistical parametric mapping (SPM) and (2) compare the differences in the force-time curve between participants with low and high RPA scores, as quantified by traditional analysis. Materials and Methods Eleven well-trained field hockey players performed an RPA assessment consisting of 20 loaded countermovement jumps with a 30% one repetition maximum half squat load (LCMJ20). Mean force-time series data was normalized to 100% of the movement duration and analysed using SPM. Peak power output for each jump was also derived from the force-time data and a percent decrement score calculated for jumps 2 to 19 (RPA%dec). An SPM one-way ANOVA with significance accepted at α = 0.05, was used to identify the change in the force-time curve over three distinct series of jumps across the LCMJ20 (series 1 = jumps 2–5, series 2 = jumps 9–12 and series 3 = jumps 16–19). A secondary analysis, using an independent T-test with significance accepted at p < 0.001, was also used to identify differences in the force-time curve between participants with low and high RPA%dec. Results Propulsive forces were significantly lower (p < 0.001) between 74–98% of the movement compared to 0–73% for changes recorded during the LCMJ20. Post hoc analysis identified the greatest differences to occur between jump series 1 and jump series 2 (p < 0.001) at 70–98% of the movement and between jump series 1 and jump series 3 (p < 0.001) at 86–99% of the movement. No significant differences were found between jump series 2 and jump series 3. Significant differences (p < 0.001) in both the braking phase at 44–48% of the jump and the propulsive phase at 74–94% of the jump were identified when participants were classified based on low or high RPA%dec scores (with low scores representing an enhanced ability to maintain peak power output than high scores). Conclusion A reduction in force during the late propulsive phase is evident as the LCMJ20 progresses. SPM analysis provides refined insight into where changes in the force-time curve occur during performance of the LCMJ20. Participants with the lower RPA%dec scores displayed both larger braking and propulsive forces across the LCMJ20 assessment.
Natera et al. (2024) Changes in the force-time curve during a repeat power ability assessment using loaded countermovement jumps. PeerJ 12:e17971 https://doi.org/10.7717/peerj.17971
Acute psycho-physiological responses to submaximal constant-load cycling under intermittent hypoxia-hyperoxia vs. hypoxia-normoxia in young males
Background Hypoxia and hyperoxia can affect the acute psycho-physiological response to exercise. Recording various perceptual responses to exercise is of particular importance for investigating behavioral changes to physical activity, given that the perception of exercise-induced pain, discomfort or unpleasure, and a low level of exercise enjoyment are commonly associated with a low adherence to physical activity. Therefore, this study aimed to compare the acute perceptual and physiological responses to aerobic exercise under intermittent hypoxia-hyperoxia (IHHT), hypoxia-normoxia (IHT), and sustained normoxia (NOR) in young, recreational active, healthy males. Methods Using a randomized, single-blinded, crossover design, 15 males (age: 24.5 ± 4.2 yrs) performed 40 min of submaximal constant-load cycling (at 60% peak oxygen uptake, 80 rpm) under IHHT (5 × 4 min hypoxia and hyperoxia), IHT (5 × 4 min hypoxia and normoxia), and NOR. Inspiratory fraction of oxygen during hypoxia and hyperoxia was set to 14% and 30%, respectively. Heart rate (HR), total hemoglobin (tHb) and muscle oxygen saturation (SmO2) of the right vastus lateralis muscle were continuously recorded during cycling. Participants’ peripheral oxygen saturation (SpO2) and perceptual responses (i.e., perceived motor fatigue, effort perception, perceived physical strain, affective valence, arousal, motivation to exercise, and conflict to continue exercise) were surveyed prior, during (every 4 min), and after cycling. Prior to and after exercise, peripheral blood lactate concentration (BLC) was determined. Exercise enjoyment was ascertained after cycling. For statistical analysis, repeated measures analyses of variance were conducted. Results No differences in the acute perceptual responses were found between conditions (p ≥ 0.059, ηp2 ≤ 0.18), while the physiological responses differed. Accordingly, SpO2 was higher during the hyperoxic periods during the IHHT compared to the normoxic periods during the IHT (p < 0.001, ηp2 = 0.91). Moreover, HR (p = 0.005, ηp2 = 0.33) and BLC (p = 0.033, ηp2 = 0.28) were higher during IHT compared to NOR. No differences between conditions were found for changes in tHb (p = 0.684, ηp2 = 0.03) and SmO2 (p = 0.093, ηp2 = 0.16). Conclusion IHT was associated with a higher physiological response and metabolic stress, while IHHT did not lead to an increase in HR and BLC compared to NOR. In addition, compared to IHT, IHHT seems to improve reoxygenation indicated by a higher SpO2 during the hyperoxic periods. However, there were no differences in perceptual responses and ratings of exercise enjoyment between conditions. These results suggest that replacing normoxic by hyperoxic reoxygenation-periods during submaximal constant-load cycling under intermittent hypoxia reduced the exercise-related physiological stress but had no effect on perceptual responses and perceived exercise enjoyment in young recreational active healthy males.
Behrendt et al. (2024) Acute psycho-physiological responses to submaximal constant-load cycling under intermittent hypoxia-hyperoxia vs. hypoxia-normoxia in young males. PeerJ 12:e18027 https://doi.org/10.7717/peerj.18027
A method for evaluating sediment-induced macroinvertebrate community composition changes in Idaho streams
Human activities can increase sediment delivery to streams, changing the composition, distribution, and abundance of stream aquatic life. Few U.S. states have numeric water quality standards for streambed sediment under the Clean Water Act, so managers often need to develop local application-specific benchmarks. This study developed stream surface fine sediment <2 mm (sand and fines, SF) and macroinvertebrate fine sediment biotic index (FSBI) benchmarks and an application framework to test for sediment-induced macroinvertebrate community composition changes in 1st–4th order Idaho streams. FSBI reference benchmarks were calculated as the 25th percentile FSBI value among reference sites within three ecoregion-based site classes. Two approaches were used to develop SF benchmarks. Quantile regression was used to define reach-specific SF benchmarks representing an upper bound value expected under reference conditions. In addition, logistic regression was used to predict SF values with 50% and 75% probability that FSBI is worse than reference within each stream order and site class. The strength of association between SF benchmarks and macroinvertebrate community condition was evaluated by calculating relative risk using multiple datasets and examining responses of multiple macroinvertebrate indicators to SF benchmark status. SF reference benchmarks generally had stronger associations with poor macroinvertebrate condition than SF stressor-response benchmarks. Across datasets and macroinvertebrate indicators, poor macroinvertebrate condition was 1.8–3 times more likely when SF reference benchmarks were exceeded than when achieved. We propose rating the strength of evidence for a surface fine sediment-induced macroinvertebrate community composition change at the sample event scale as ‘unlikely’ if both SF and FSBI reference benchmarks are achieved, having ‘mixed evidence’ if only one reference benchmark is achieved, and ‘likely’ if both reference benchmarks are not achieved. We recommend combining ratings with other relevant data in a weight-of-evidence approach to assess if sediment impairs aquatic life.
Williams et al. (2024) A method for evaluating sediment-induced macroinvertebrate community composition changes in Idaho streams. PeerJ 12:e18060 https://doi.org/10.7717/peerj.18060
Beyond graft function impairment after liver transplantation: the prolonged cold ischemia time impact on recurrence of hepatocellular carcinoma after liver transplantation—a single-center retrospective study
Purpose Hepatocellular carcinoma (HCC) is one of the malignant tumors responsible for high mortality and recurrence rates. Although liver transplantation (LT) is an effective treatment option for HCC, ischemia-reperfusion injury (IRI) is a contributor to HCC recurrence after LT. Moreover, prolonged cold ischemia time (CIT) is a risk factor for IRI during LT, and there is insufficient clinical evidence regarding the impact of CIT on HCC recurrence after LT. Patients and Methods This retrospective study analyzed 420 patients who underwent LT for HCC between February 2015 and November 2020 at The First Affiliated Hospital, Sun Yat-sen University. The duration of CIT was defined as the time from clamping of the donor aorta until portal reperfusion. Results A total of 133 patients (31.7%) experienced tumor recurrence after LT, and CIT > 568 min was the independent risk factor for HCC recurrence (OR, 2.406; 95% CI [1.371–4.220]; p = 0.002). Multivariate Cox’s regression analysis revealed that the recipients’ gender, exceeding Milan criteria, poor differentiation, and alpha-fetoprotein (AFP) ≥400 ng/ml in CIT > 568 min group were independent risk factors for disease-free survival. The peak 7-day postoperative alanine aminotransferase (ALT) level (p < 0.001), the peak 7-day postoperative aspartate aminotransferase (AST) level (p < 0.001), the peak 7-day postoperative peak total bilirubin (TBIL) level (p = 0.012), and the incidence of early allograft dysfunction (EAD) (p = 0.006) were significantly higher in the CIT > 568 min group compared to the CIT ≤ 568 min group. Moreover, the amount of fresh frozen plasma (FFP) infusion during the operation increased (p = 0.02), and the time of mechanical ventilation postoperative was longer (p = 0.045). Conclusion An effective strategy to improve the prognosis is to reduce CIT; this strategy lowers the recurrence of HCC in patients undergoing LT, especially those within the Milan criteria.
Yu et al. (2024) Beyond graft function impairment after liver transplantation: the prolonged cold ischemia time impact on recurrence of hepatocellular carcinoma after liver transplantation—a single-center retrospective study. PeerJ 12:e18126 https://doi.org/10.7717/peerj.18126
Impact of foam rolling with and without vibration on muscle oxidative metabolism and microvascular reactivity
Background and Purpose There is a growing interest in use vibration foam rolling as a warm up and recovery tool. However, whether vibration foam rolling offers additional benefits to traditional foam rolling is unclear. The current study aims to compare the effects of acute foam rolling, with and without vibration, on skeletal muscle metabolism and microvascular reactivity. Methods Fifteen physically active young males were tested on two different days, with gastrocnemius muscle microvascular function assessed using near-infrared spectroscopy coupled with the post-occlusive reactive hyperemia technique, before and after foam rolling, performed with or without vibration. The slope of tissue saturation index (TSI) decrease during occlusion between 120 s to 150 s (TSI occlusion slope) was assessed for muscle metabolic rate. Three commonly used microvascular function indexes, including the first10s TSI slope after occlusion (TSI10), time for TSI to reach half of peak magnitude (TSI1/2), and TSI peak reactive hyperemia, were also assessed. Results None of the measured indexes showed significance for interaction or method (all p > 0.05). However, there was a main effect for time for TSI occlusion slope, TSI1/2, and TSI peak reactive hyperemia (p = 0.005, 0.034 and 0.046, respectively). No main effect for time for TSI10 was detected (p = 0.963). Conclusions The application of foam rolling can decrease muscle metabolism, and may improve some aspects of muscle microvascular function. However, vibration foam rolling does not seem to offer any additional benefits compared to traditional foam rolling alone.
Huang et al. (2024) Impact of foam rolling with and without vibration on muscle oxidative metabolism and microvascular reactivity. PeerJ 12:e18180 https://doi.org/10.7717/peerj.18180
Association between triglyceride glycemic index and ejection fraction preserved heart failure in hypertensive patients
Background The triglyceride-glucose (TyG) index is regarded as an independent predictor of cardiovascular disease consequences and a reliable surrogate measure of insulin resistance (IR). However, the correlation analysis between triglyceride glucose index and heart failure with preserved ejection fraction in patients with essential hypertension remains unknown. Methods A single-center, retrospective study was conducted with patients diagnosed with essential hypertension at the First Affiliated Hospital of Xinjiang Medical University, from December 2018 to September 2020. Participants were selected based on specific inclusion and exclusion criteria, with their clinical data and laboratory tests collected. The study employed Spearman’s correlation analysis, logistic regression models, restricted cubic spline plots, and receiver operating characteristic (ROC) curves to investigate the relationships between the TyG index and HFpEF. Results Out of 1,602 enrolled hypertensive patients, 992 were included in the analysis after applying exclusion criteria. Patients were categorized into tertiles based on the TyG index, which showed that patients in the highest tertile had characteristics associated with a higher risk of HFpEF, including age, body mass index (BMI), systolic blood pressure (SBP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and left ventricular mass index (LVMI). A significant, independent association between the TyG index and HFpEF was confirmed, with an odds ratio (OR) of 5.127 (95% CI [3.894–6.856]). Furthermore, an S-shaped nonlinear relationship was observed between the TyG index and the incidence of HFpEF (nonlinear p < 0.001). TyG index (AUC: 0.824, 95% CI [0.795–0.854]), NT-proBNP (AUC: 0.840, 95% CI [0.816–0.864]), and LVMI (AUC: 0.847, 95% CI [0.820–0.875]) showed good predictive ability for HFpEF. In addition, the TyG+LVMI combination demonstrated the strongest predictive ability (AUC: 0.907, 95% CI [0.887–0.927]). Conclusion The study underscores a significant association between IR, as indicated by the TyG index, and the development of HFpEF in hypertensive patients. It highlights the critical role of metabolic dysfunction in the pathophysiology of HFpEF, advocating for a broader perspective on cardiovascular risk management.
Shan et al. (2024) Association between triglyceride glycemic index and ejection fraction preserved heart failure in hypertensive patients. PeerJ 12:e18220 https://doi.org/10.7717/peerj.18220
The non-HDL-C to APOB ratio as a predictor of inaccurate LDL-C measurement in patients with chronic intrahepatic cholestasis and jaundice: a retrospective study
Background Cholestasis is characterized by the accumulation of bile in the liver or biliary system due to obstruction or impaired flow, necessitating lipid profiling to assess lipid metabolism abnormalities. Intrahepatic cholestasis, being the most significant type of cholestasis, further complicates the assessment of lipid abnormalities. However, the accuracy of low-density lipoprotein cholesterol (LDL-C) measurement in intrahepatic cholestasis patients remains uncertain. Objective This study aimed to evaluate the consistency of the homogeneous assay and the Friedewald formula in detecting LDL-C levels and identify factors influencing LDL-C test results in intrahepatic patients with cholestasis. Methods Retrospective analysis of laboratory data was conducted on intrahepatic cholestatic patients. Correlations between LDL-C values obtained using the homogeneous method (LDL-C(D)) and the Friedewald formula (LDL-C(F)), as well as associations between high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (ApoA1), LDL-C(D) and LDL-C(F), and apolipoprotein B (ApoB), were analyzed. Logistic regression analyses were employed to identify diagnostic indicators for inaccurate LDL-C measurements in intrahepatic cholestatic patients. Results Compared to patients with intrahepatic cholestasis without jaundice, the correlation between LDL-C(F) and LDL-C(D) was weaker in those with jaundice. Additionally, HDL-C exhibited a strong correlation with ApoA1 in both jaundice and non-jaundice cholestasis cases. Elevated non-HDL-C to APOB ratio (NH-C/B Ratio) levels (>4.5) were identified as a reliable predictor of inaccurate LDL-C measurements in patients with chronic intrahepatic cholestasis accompanied by jaundice. Conclusions LDL-C measurement reliability is moderately weaker in patients with intrahepatic cholestasis accompanied by jaundice. Elevated levels of the NH-C/B ratio serve as a significant predictor of inaccurate LDL-C measurements in this chronic patient population, highlighting its clinical relevance for diagnostic assessments.
Cheng et al. (2024) The non-HDL-C to APOB ratio as a predictor of inaccurate LDL-C measurement in patients with chronic intrahepatic cholestasis and jaundice: a retrospective study. PeerJ 12:e18224 https://doi.org/10.7717/peerj.18224
Reliability and reproducibility of an Italian questionnaire on “Knowledge of high social impact Eye Diseases” (KED-IT)
Background Health literacy plays an important role in public health. Although this has been demonstrated in the field of ophthalmology, there are very few specific instruments available to assess eye health literacy. This work aims to develop an Italian questionnaire on knowledge of eye diseases (Knowledge on Eye Disease, Italian version; KED-IT) and to evaluate its reliability and reproducibility. The KED-IT focuses on diseases with high social impact, specifically glaucoma, macular degeneration, diabetic retinopathy and keratoconus, which is the main cause of corneal transplant in Italy. Methods A cross-sectional study was conducted. The KED-IT was self-administered by the study participants twice. The interval between each administration (T0 and T1) was 5 to 8 days. Reliability was assessed using the KR-20 coefficient. The test-retest Cohen’s Kappa coefficient was estimated to measure the stability and reproducibility of the results obtained between T0 and T1. Results A total of 60 subjects participated in the study. The response rate at T1 was 92%. The KR-20 reliability coefficient of the 14-item KED-IT questionnaire was good with a value of 0.878. The Cohen’s kappa value for all 14 items of the KED-IT questionnaire was k = 0.747, indicating good agreement. Conclusions The KED-IT is the first specific ophthalmic knowledge questionnaire validated in the Italian language and we hope that it may be a starting point for the study of eye health literacy in the Italian population.
Iannucci et al. (2024) Reliability and reproducibility of an Italian questionnaire on “Knowledge of high social impact Eye Diseases” (KED-IT). PeerJ 12:e17906 https://doi.org/10.7717/peerj.17906
Nanotechnology in action: silver nanoparticles for improved eco-friendly remediation
Nanotechnology is an exciting area with great potential for use in biotechnology due to the far-reaching effects of nanoscale materials and their size-dependent characteristics. Silver and other metal nanoparticles have attracted a lot of attention lately because of the exceptional optical, electrical, and antimicrobial characteristics they possess. Silver nanoparticles (AgNPs) stand out due to their cost-effectiveness and abundant presence in the earth’s crust, making them a compelling subject for further exploration. The vital efficacy of silver nanoparticles in addressing environmental concerns is emphasized in this thorough overview that dives into their significance in environmental remediation. Leveraging the distinctive properties of AgNPs, such as their antibacterial and catalytic characteristics, innovative solutions for efficient treatment of pollutants are being developed. The review critically examines the transformative potential of silver nanoparticles, exploring their various applications and promising achievements in enhancing environmental remediation techniques. As environmental defenders, this study advocates for intensified investigation and application of silver nanoparticles. Furthermore, this review aims to assist future investigators in developing more cost-effective and efficient innovations involving AgNPs carrying nanoprobes. These nanoprobes have the potential to detect numerous groups of contaminants simultaneously, with a low limit of detection (LOD) and reliable reproducibility. The goal is to utilize these innovations for environmental remediation purposes.
Environmental Contamination and Remediation
Krishna et al. (2024) Nanotechnology in action: silver nanoparticles for improved eco-friendly remediation. PeerJ 12:e18191 https://doi.org/10.7717/peerj.18191
PotatoG-DKB: a potato gene-disease knowledge base mined from biological literature
Background Potato is the fourth largest food crop in the world, but potato cultivation faces serious threats from various diseases and pests. Despite significant advancements in research on potato disease resistance, these findings are scattered across numerous publications. For researchers, obtaining relevant knowledge by reading and organizing a large body of literature is a time-consuming and labor-intensive process. Therefore, systematically extracting and organizing the relationships between potato genes and diseases from the literature to establish a potato gene-disease knowledge base is particularly important. Unfortunately, there is currently no such gene-disease knowledge base available. Methods In this study, we constructed a Potato Gene-Disease Knowledge Base (PotatoG-DKB) using natural language processing techniques and large language models. We used PubMed as the data source and obtained 2,906 article abstracts related to potato biology, extracted entities and relationships between potato genes and related disease, and stored them in a Neo4j database. Using web technology, we also constructed the Potato Gene-Disease Knowledge Portal (PotatoG-DKP), an interactive visualization platform. Results PotatoG-DKB encompasses 22 entity types (such as genes, diseases, species, etc.) of 5,206 nodes and 9,443 edges between entities (for example, gene-disease, pathogen-disease, etc.). PotatoG-DKP can intuitively display associative relationships extracted from literature and is a powerful assistant for potato biologists and breeders to understand potato pathogenesis and disease resistance. More details about PotatoG-DKP can be obtained at https://www.potatogd.com.cn/.
Xie et al. (2024) PotatoG-DKB: a potato gene-disease knowledge base mined from biological literature. PeerJ 12:e18202 https://doi.org/10.7717/peerj.18202