Background: Paralympic Powerlifting (PP) training tends to promote fatigue and oxidative stress. Objective: To analyze the effects of ibuprofen use on performance and oxidative stress in ...post-training PP athletes. Methodology: Ten national level PP athletes (age: 27.13 ± 5.57) were analyzed for oxidative stress in post-training. The study was carried out in three weeks, (1) familiarization and (2 and 3) evaluated the recovery with the use of a placebo (PLA) and ibuprofen (IBU), 800 mg. The Peak Torque (PT), Torque Development Rate (TDR), Fatigue Index (FI), reactive substances to thiobarbituric acid (TBARS) and sulfhydryl groups (SH) were evaluated. The training consisted of five sets of five repetitions (80–90%) 1-Repetition Maximum (1-RM) in the bench press. Results: The IBU showed a higher PT (24 and 48 h, p = 0.04, ɳ2 p = 0.39), a lower FI (24 h, p = 0.01, ɳ2p = 0.74) and an increased lymphocyte count (p < 0.001; ɳ2p = 4.36). There was no change in oxidative stress. Conclusions: The use of IBU provided improvements in strength and did not protect against oxidative stress.
The Saprolegniosis causes major reduction egg hatching rate by angelfish (Pterophyllum scalare); therefore, we investigated the effectiveness of two Terminalia catappa extracts (27 ℃ and 80 ℃) ...against S. parasitica on fish eggs. Mycelium growth was evaluated in vitro at 0, 2.5, 5.0 and 10 g/L for 96 h, in solid and liquid medium culture. In an in vivo assay, we tested lower concentrations of hot extract (25, 50 and 100 mg/L) to prevent infection by zoospores. The hot aqueous extract was the most effective, and the concentrations of 5 and 10 g/L demonstrated great efficiency in liquid medium. In vivo conditions, 50 and 100 mg/L of hot extract provided more viable eggs, greater percentage of total larvae and lower percentage of infected eggs. Thus, the hot extract should be used instead of the room‐temperature extract as a prophylactic measure, to prevent saprolegniosis in P. scalare eggs and improving the hatching rate.
Background: Vaccine hesitancy is a complex challenge that demands a comprehensive approach, one that not only acknowledges legitimate concerns within communities but also actively confronts ...misinformation. In this context, this study aimed to investigate the prevalence of belief in conspiracy theories about COVID-19 vaccines among Brazilians, seeking to understand the factors associated with this behavior. Method: Utilizing a national online survey conducted between May and August 2020, with a sample of 4247 participants, we conducted multivariate analysis to identify the independent determinants of this adherence, calculating adjusted prevalence ratios (APRs) and their 95% confidence intervals. Results: It was revealed that 27.7% of participants believed in at least one conspiracy theory. Factors associated with a higher level of adherence included agreement with at least one piece of COVID-19 misinformation on social media (APR: 3.65; 95% CI: 3.07–4.34), lack of difficulty accessing leisure activities during the pandemic (APR: 3.11; 95% CI: 1.85–5.24), age 50 years or older (APR: 1.70; 95% CI: 1.49–1.94), absence of difficulty accessing protective measures (APR: 1.47; 95% CI: 1.26–1.72), use of face masks (APR: 1.62; 95% CI: 1.33–1.97), non-use of at least one traditional media source for information (APR: 1.47; 95% CI: 1.26–1.72), female gender (APR: 1.41; 95% CI: 1.25–1.60), and age between 30 and 49 years (APR: 1.35; 95% CI: 1.19–1.52). Conclusions: Our findings highlight that it is crucial to recognize that vaccine hesitancy is not merely an isolated phenomenon but often rooted in a complex interplay of social, cultural, psychological, and political factors. There is a need for multifaceted strategies to combat vaccine hesitancy, effectively address conspiracy theories, and consider the various factors associated with their prevalence.
Nuclear power systems turned to space electric propulsion differ strongly from usual ground-based power systems regarding the importance of overall size and mass. For propulsion power systems, size ...and mass are essential drivers that should be minimized during conception processes. Considering this aspect, this paper aims the development of a design-based model of a Closed Regenerative Brayton Cycle that applies the thermal conductance of the main components in order to predict the energy conversion performance, allowing its use as a preliminary tool for heat exchanger and radiator panel sizing. The centrifugal-flow turbine and compressor characterizations were achieved using algebraic equations from literature data. A binary mixture of Helium–Xenon with molecular weight of 40 g/mole is applied and the impact of the components sizing in the energy efficiency is evaluated in this paper, including the radiator panel area. Moreover, an optimization analysis based on the final mass of heat the exchangers is performed.
•A design-based model of a Closed Brayton Cycle is proposed for nuclear space needs.•Turbomachinery efficiency presented a strong influence on the system efficiency.•Radiator area presented the highest potential to increase the system efficiency.•There is maximum system efficiency for each total mass of heat exchangers.•Size or efficiency optimization was performed by changing heat exchanger proportion.
Amazon and Cerrado‐forested streams show natural fluctuations in leaf litter quantity along the time and space, suggesting a change on litter quality input. These natural fluctuations of leaf litter ...have repercussion on the organic matter cycling and consequently effects on leaf decomposition in forested streams. The effects of the quantity of leaf litter with contrasting traits on consumption by larvae of shredder insects from biomes with different organic matter dynamics have still been an understudied question. The Trichoptera Phylloicus spp. is a typical shredder in tropical headwater streams and keep an important role in leaf litter decomposition. Here, we assessed the consumption by shredder Phylloicus spp., from Amazonia and Cerrado biomes, on higher (Maprounea guianensis) and lower quality leaves (Inga laurina) in different proportions and quantities. Experiments were performed concomitantly in microcosms approaches, simulating Cerrado and Amazonian streams. Higher leaf consumption occurred in Cerrado microcosms. Litter quantity influenced negatively leaf consumption by shredders in Cerrado, in opposition to Amazonia, where consumption was not affected by leaf quantity. In both sites, we observed higher consumption by shredders in treatment with only M. guianensis and no difference between other treatments with mixture of leaves. In treatment with litter of I. laurina, we noted the use of substrate for case building (due to the higher leaf toughness), affecting the fragmentation process. Therefore, our results indicate that leaf litter quality drives the preference of consumption by Phylloicus larvae in Cerrado and Amazonia streams.
Our study performed in two Brazilian biomes showed a higher consumption by shredders in treatment with just the better quality leaf litter and no difference between other treatments with mixture of leaves, demonstrating how leaf litter quality is important for breaking down the organic matter. In addition, our results help to explain how the availability of leaf litter might affect its use by Phylloicus in the Cerrado, in opposition to the from Amazon. Therefore, our results indicate that leaf traits drive the preference of litter consumption by Phylloicus larvae in Cerrado and Amazonia streams.
Paralympic Powerlifting is a sport in which the strength of the upper limbs is assessed through bench press performance in an adapted specific bench. It is therefore essential to optimize training ...methods to maximize this performance. The aim of the present study was to compare force production and muscle activation involved in partial vs. full range of motion (ROM) training in Paralympic Powerlifting. Twelve male athletes of elite national level in Paralympic Powerlifting participated in the study (28.60 ± 7.60 years of age, 71.80 ± 17.90 kg of body mass). The athletes performed five sets of 5RM (repetition maximum), either with 90% of 1RM in full ROM or with a load of 130% 1RM in partial ROM. All subjects underwent both exercise conditions in consecutive weeks. Order assignment in the first week was random and counterbalanced. Fatigue index (FI), Maximum Isometric Force (MIF), Time to MIF (Time) and rate of force development (RFD) were determined by a force sensor. Muscle thickness was obtained using ultrasound images. All measures were taken pre- and post-training. Additionally, electromyographic signal (EMG) was evaluated in the last set of each exercise condition. Post-exercise fatigue was higher with full ROM as well as loss of MIF. Full ROM also induced greater. EMG showed greater activation of the Clavicular portion and Sternal portion of pectoralis major muscle and lower in the anterior portion of deltoid muscle when full ROM was performed. Muscle thickness of the pectoralis major muscle increased post-exercise. We concluded that training with partial ROM enables higher workloads with lower loss of muscle function.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Imbalances in metal ions (Cu2+, Fe3+, and Zn2+) augment oxidative stress, and can lead to amyloid-β (Aβ) peptide aggregation, a phenomenon that is associated with Alzheimer's disease (AD) ...progression. As such, the use of particles that can cross the blood-brain barrier (BBB) and chelate metals could potentially provide a therapy to restore ionic balance in AD. Herein, we functionalized chitosan microparticles (CM) with histidine (an amino acid that contains an imidazole group, therefore mimicking Aβ) to chelate Cu2+, Fe3+, and Zn2+. CM were prepared by spray-drying and and functionalized with histidine (CM-Histidine). The CM, before and after functionalization, and interacting with metal ions were characterized by scanning electron microscopy with energy dispersive spectroscopy, x-ray diffraction and potentiometric titration. The adsorption capacity of CM-Histidine increased for Cu2+ and decreased for Zn2+ and Fe3+, when compared to unmodified CM. However, the adsorption kinetics for Cu2+ ions was lower for CM-histidine, than for CM, and the reverse was observed for Zn2+ and Fe3+. External mass resistance was the major factor that defined the mass transfer mechanism onto the active sites of CM-histidine. Diffusional effects were more relevant for Zn2+ and Fe3+ in the sorption process than for Cu2+.
Display omitted
•Histidine as a coupling agent to mimic amyloid-β and improve metal adsorption.•Adsorption increased for Cu2+ and decreased for Zn2+/Fe3+ on chitosan-histidine.•Affinity of Cu2+ decreased for chitosan-histidine, while it increased for Zn2+/Fe3+.•Diffusional effects were more relevant for Zn2+/Fe3+ than for Cu2+ in the adsorption.
Objectives
To evaluate the diagnostic test accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), whole-body magnetic resonance imaging (WB-MRI), and ...whole-body diffusion-weighted imaging (WB-DWI) for the detection of metastases in patients with non–small cell lung cancer (NSCLC).
Methods
MEDLINE, Embase, and Cochrane Library databases were searched up to June 2019. Studies were selected if they reported data that could be used to construct contingency tables to compare 18F-FDG PET/CT, WB-MRI, and WB-DWI. Two authors independently extracted data on study characteristics and assessed methodological quality using the Quality Assessment of Diagnostic Accuracy Studies. Forest plots were generated for sensitivity and specificity of 18F-FDG PET/CT, WB-MRI, and whole-body diffusion-weighted imaging (WB-DWI). Summary receiver operating characteristic plots were created.
Results
The 4 studies meeting inclusion criteria had a total of 564 patients and 559 lesions, 233 of which were metastases. In studies of 18F-FDG PET/CT, the pooled estimates of sensitivity and specificity were 0.83 (95% confidence interval CI, 0.54–0.95) and 0.93 (95% CI, 0.87–0.96), respectively. For WB-MRI, pooled sensitivity was 0.92 (95% CI, 0.18–1.00) and pooled specificity was 0.93 (95% CI, 0.85–0.95). Pooled sensitivity and specificity for WB-DWI were 0.78 (95% CI, 0.46–0.93) and 0.91 (95% CI, 0.79–0.96), respectively. There was no statistical difference between the diagnostic odds ratio of WB-MRI and WB-DWI compared with that of PET/CT (
p
= 0.186 for WB-DWI;
p
= 0.638 for WB-MRI).
Conclusion
WB-MRI and DWI are radiation-free alternatives with comparable diagnostic performance to 18F-FDG PET/CT for M staging of NSCLC.
Key Points
• Whole-body MRI with or without diffusion-weighted imaging has a high accuracy for the diagnostic evaluation of metastases in patients with non–small cell lung cancer.
• Whole-body MRI may be used as a non-invasive and radiation-free alternative to positron emission tomography with CT with similar diagnostic performance.
The zwitterions resulting from the covalent attachment of 3- or 4-hydroxy benzene to the 1,3-dimethylimidazolium cation represent basic compounds (pKa of 8.68 and 8.99 in aqueous solutions, ...respectively) that chemisorb in aqueous solutions 0.58 mol/mol of carbon dioxide at 1.3 bar (absolute) and 40 °C. Equimolar amounts of chemisorbed CO
in these solutions are obtained at 10 bar and 40 °C. Chemisorption takes place through the formation of bicarbonate in the aqueous solution using imidazolium-containing phenolate. CO
is liberated by simple pressure relief and heating, regenerating the base. The enthalpy of absorption was estimated to be -38 kJ/mol, which is about 30 % lower than the enthalpy of industrially employed aqueous solutions of MDEA (estimated at -53 kJ/mol using the same experimental apparatus). The physisorption of CO
becomes relevant at higher pressures (>10 bar) in these aqueous solutions. Combined physio- and chemisorption of up to 1.3 mol/mol at 40 bar and 40 °C can be attained with these aqueous zwitterionic solutions that are thermally stable and can be recycled at least 20 times.
PDF
