oxygen consumption
Recently Published Documents


TOTAL DOCUMENTS

11605
(FIVE YEARS 1014)

H-INDEX

138
(FIVE YEARS 9)

2022 ◽  
Vol 176 ◽  
pp. 106516
Author(s):  
Jonas Stage Sø ◽  
Theis Kragh ◽  
Kaj Sand-Jensen ◽  
Kenneth Thorø Martinsen

Author(s):  
Jing Bao

AbstractWith the continuous increase in social pressure and people’s higher urgency for physical health, the concept of healthy physical fitness has become more and more important and prominent. However, the research and standards for the validity of the health fitness monitoring test indicators have not been determined. In order to compare the validity of the health fitness test indicators, we adopt the cardiopulmonary track and field sensor technology to monitor the health fitness cardiopulmonary track and field sensor. A comparative study on the validity of test indicators, mainly to test the rationality of the cardiopulmonary endurance evaluation indicators of healthy physical fitness, and to carry out a new design of the concept of healthy physical fitness in track and field teaching, so that it is more inclined to improve the healthy physical fitness of athletes fitness. Research data shows that the average absolute value of the athlete’s maximum oxygen consumption is 2.51 L/min, the highest value is 3.96 L/min, and the lowest is 2.03 L/min. The average value of the absolute maximum oxygen consumption of girls is 1.79 L/min, the highest value is 2.89 L/min, and the minimum is 1.51 L/min. From these data, we can know that compared with traditional cardiopulmonary monitoring methods, the sensor monitoring studied in this paper has higher accuracy and wider application range. The peak cardiopulmonary power of athletes’ cardiopulmonary function detection using this method is closer to the actual value, while for the peak cardiopulmonary power detected by traditional methods, there is a big difference between the power and the actual value. For different athletes, the advantages of the algorithm in this paper are more obvious, indicating that the method in this paper has a higher detection accuracy for the cardiopulmonary function test of athletes during aerobic training.


Author(s):  
Mohammad Mehdi Alemi ◽  
Athulya A. Simon ◽  
Jack Geissinger ◽  
Alan T. Asbeck

Despite several attempts to quantify the metabolic savings resulting from the use of passive back-support exoskeletons (BSEs), no study has modeled the metabolic change while wearing an exoskeleton during lifting. The objectives of this study were to: 1) quantify the metabolic reductions due to the VT-Lowe's exoskeleton during lifting; and 2) provide a comprehensive model to estimate the metabolic reductions from using a passive BSE. In this study, 15 healthy adults (13M, 2F) of ages 20 to 34 years (mean=25.33, SD=4.43) performed repeated freestyle lifting and lowering of an empty box and a box with 20% of their bodyweight. Oxygen consumption and metabolic expenditure data were collected. A model for metabolic expenditure was developed and fitted with the experimental data of two prior studies and the without-exoskeleton experimental results. The metabolic cost model was then modified to reflect the effect of the exoskeleton. The experimental results revealed that VT-Lowe's exoskeleton significantly lowered the oxygen consumption by ~9% for an empty box and 8% for a 20% bodyweight box, which corresponds to a net metabolic cost reduction of ~12% and ~9%, respectively. The mean metabolic difference (i.e., without-exo minus with-exo) and the 95% confidence interval were 0.36 and (0.2-0.52) [Watts/kg] for 0% bodyweight, and 0.43 and (0.18-0.69) [Watts/kg] for 20% bodyweight. Our modeling predictions for with-exoskeleton conditions were precise, with absolute freestyle prediction errors of <2.1%. The model developed in this study can be modified based on different study designs, and can assist researchers in enhancing designs of future lifting exoskeletons.


2022 ◽  
Author(s):  
Masudah Paleker ◽  
Mary-Ann Davies ◽  
Peter Raubenheimer ◽  
Jonathan Naude ◽  
Andrew Boulle ◽  
...  

Fewer COVID-19 deaths have been reported in this fourth wave, with clinicians reporting less admissions due to severe COVID-19 pneumonia when compared to previous waves. We therefore aimed to rapidly compare the profile of deaths in wave 4 with wave 3 using routinely collected data on admissions to public sector hospitals in the Western Cape province of South Africa. Findings show that there have been fewer COVID-19 pneumonia deaths in the Omicron-driven fourth wave compared to the third wave, which confirms anecdotal reports and lower bulk oxygen consumption by hospitals in the province.


2022 ◽  
Vol 18 ◽  
Author(s):  
Vivian Cordeiro Rodrigues ◽  
William Queiroz Felippe ◽  
Carla Marins Goulart ◽  
Aurea Echevarria ◽  
Ana Paula Pereira da Silva

Background: Chalcones are open-chain flavonoids especially attractive to medicinal chemistry due to their easy synthesis and the possibility of structural modifications. Objective: Evaluate the in vitro anticancer activity of a series of hybrids chalcones-thiosemicarbazones against the human hepatocellular carcinoma cell line, HepG2. Methods: Seven hybrid chalcones-thiosemicarbazones (CTs), 3-(4’-X-phenyl)-1-phenylprop-2-en-1-one thiosemicarbazone, where X=H (CT-H), CH3 (CT-CH3), NO2 (CT-NO2), Cl (CT-Cl), CN (CT-CN), F (CT-F) and Br (CT-Br), were synthesized and their effects on cells viability and mitochondrial oxygen consumption were accessed. Results: Incubation with CTs caused a decrease in HepG2 cells viability in a time-concentration-dependent manner. The most effective compounds in inhibiting cell viability, after 24 hours of treatment, were CT-Cl and CT-CH3 (IC50 20.9 and 23.63 μM, respectively). In addition, using 10 M and only 1 hour of pre-incubation, CT-CH3 caused a reduction in basal respiration (-37%), oxygen consumption coupled with ATP synthesis (-60%) and maximum oxygen consumption (-54%). These alterations in respiratory parameters may be involved with the inhibitory effects of CT-CH3, since significant changes in oxygen consumption rates were observed in a condition that anticipates more significant losses of cell viability. The ADME parameters and the no violation of Lipinski Rule of Five showed that all compounds are safe. Conclusion: These results may contribute to the knowledge about the effects of CTs on these cells and the development of new treatments against HCCs.


Author(s):  
Daniel P. Longman ◽  
Viviane Merzbach ◽  
Jorge Marques Pinto ◽  
Laura Hope Atkinson ◽  
Jonathan C. K. Wells ◽  
...  

Abstract Objective A suite of adaptations facilitating endurance running (ER) evolved within the hominin lineage. This may have improved our ability to reach scavenging sites before competitors, or to hunt prey over long distances. Running economy (RE) is a key determinant of endurance running performance, and depends largely on the magnitude of force required to support body mass. However, numerous environmental factors influence body mass, thereby significantly affecting RE. This study tested the hypothesis that alternative metabolic strategies may have emerged to enable ER in individuals with larger body mass and poor RE. Methods A cohort of male (n = 25) and female (n = 19) ultra-endurance runners completed submaximal and exhaustive treadmill protocols to determine RE, and V̇O2Max. Results Body mass was positively associated with sub-maximal oxygen consumption at both LT1 (male r=0.66, p<0.001; female LT1 r=0.23, p=0.177) and LT2 (male r=0.59, p=0.001; female r=0.23, p=0.183) and also with V̇O2Max (male r=0.60, p=0.001; female r=0.41, p=0.046). Additionally, sub-maximal oxygen consumption varied positively with V̇O2Max in both male (LT1 r=0.54, p=0.003; LT2 r=0.77, p<0.001) and female athletes (LT1 r=0.88, p<0.001; LT2 r=0.92, p<0.001). Conclusions The results suggest that, while individuals with low mass and good RE can glide economically as they run, larger individuals can compensate for the negative effects their mass has on RE by increasing their capacity to consume oxygen. The elevated energy expenditure of this low-economy high-energy turnover approach to ER may bring costs associated with energy diversion away from other physiological processes, however.


2022 ◽  
Vol 14 ◽  
Author(s):  
Zanda Bakaeva ◽  
Natalia Lizunova ◽  
Ivan Tarzhanov ◽  
Dmitrii Boyarkin ◽  
Svetlana Petrichuk ◽  
...  

Lipopolysaccharide (LPS), a fragment of the bacterial cell wall, specifically interacting with protein complexes on the cell surface, can induce the production of pro-inflammatory and apoptotic signaling molecules, leading to the damage and death of brain cells. Similar effects have been noted in stroke and traumatic brain injury, when the leading factor of death is glutamate (Glu) excitotoxicity too. But being an amphiphilic molecule with a significant hydrophobic moiety and a large hydrophilic region, LPS can also non-specifically bind to the plasma membrane, altering its properties. In the present work, we studied the effect of LPS from Escherichia coli alone and in combination with the hyperstimulation of Glu-receptors on the functional state of mitochondria and Ca2+ homeostasis, oxygen consumption and the cell survival in primary cultures from the rats brain cerebellum and cortex. In both types of cultures, LPS (0.1–10 μg/ml) did not change the intracellular free Ca2+ concentration ([Ca2+]i) in resting neurons but slowed down the median of the decrease in [Ca2+]i on 14% and recovery of the mitochondrial potential (ΔΨm) after Glu removal. LPS did not affect the basal oxygen consumption rate (OCR) of cortical neurons; however, it did decrease the acute OCR during Glu and LPS coapplication. Evaluation of the cell culture survival using vital dyes and the MTT assay showed that LPS (10 μg/ml) and Glu (33 μM) reduced jointly and separately the proportion of live cortical neurons, but there was no synergism or additive action. LPS-effects was dependent on the type of culture, that may be related to both the properties of neurons and the different ratio between neurons and glial cells in cultures. The rapid manifestation of these effects may be the consequence of the direct effect of LPS on the rheological properties of the cell membrane.


Author(s):  
Sergio Godoy-Olmos ◽  
Ignacio Jauralde ◽  
Raquel Monge-Ortiz ◽  
María C. Milián-Sorribes ◽  
Miguel Jover-Cerdá ◽  
...  

AbstractGilthead sea bream (Sparus aurata) was raised in six individual recirculating aquaculture systems (RAS) whose biofilters’ performance was analyzed. Fish were fed with three different diets (a control diet, a fishmeal-based diet (FM), and a plant meal-based diet (VM)) and with three different feeding strategies (manual feeding to apparent satiation, automatic feeding with restricted ration, and auto-demand feeding). For every combination of diet and feeding strategy, the mean oxygen consumption, ammonia excretion, and ammonia removal rate were determined. Fish fed with the VM diet consumed the most oxygen (20.06 ± 1.80 gO2 consumed kg−1 day−1). There were significant differences in ammonia excretion depending on the protein content and protein efficiency of the diet, as well as depending on feeding strategy, which in turn affected ammonia removal rates. Fish fed by auto-demand feeders led to the highest mean ammonia removal rate (0.10 gN-TAN removed m−2 biofiltration area day−1), while not leading to peaks of high ammonia concentration in water, which preserve fish welfare and growth.


Sign in / Sign up

Export Citation Format

Share Document