Cardiopulmonary response to unloaded cycling may be related to higher workloads. This was assessed in male subjects: 18 healthy sedentary subjects (controls), 14 hypoxemic patients with chronic obstructive pulmonary disease (COPD), and 31 overweight individuals (twelve were hypoxemic). They underwent an incremental exercise up to the maximal oxygen uptake (VO2max), preceded by a 2 min unloaded cycling period. Oxygen uptake (VO2), heart rate (HR), minute ventilation (VE), and respiratory frequency (fR) were averaged every 10 s. At the end of unloaded cycling period, HR increase was significantly accentuated in COPD and hypoxemic overweight subjects (resp., +14 ± 2 and +13 ± 1.5 min(-1), compared to +7.5 ± 1.5 min(-1) in normoxemic overweight subjects and +8 ± 1.8 min(-1) in controls). The fR increase was accentuated in all overweight subjects (hypoxemic: +4.5 ± 0.8; normoxemic: +3.9 ± 0.7 min(-1)) compared to controls (+2.5 ± 0.8 min(-1)) and COPDs (+2.0 ± 0.7 min(-1)). The plateau VE increase during unloaded cycling was positively correlated with VE values measured at the ventilatory threshold and VO2max. Measurement of ventilation during unloaded cycling may serve to predict the ventilatory performance of COPD patients and overweight subjects during an exercise rehabilitation program.
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http://dx.doi.org/10.1155/2015/378469 | DOI Listing |
Pharmaceutics
December 2024
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830046, China.
Background: The clinical efficacies of anticancer drugs are limited by non-selective toxic effects on healthy tissues and low bioavailability in tumor tissue. Therefore, the development of vehicles that can selectively deliver and release drugs at the tumor site is critical for further improvements in patient survival.
Methods: We prepared a CEC nano-drug delivery system, CEC@ZIF-8, with a zeolite imidazole framework-8 (ZIF-8) as a carrier, which can achieve the response of folate receptor (FR).
Antioxidants (Basel)
November 2024
Department of Medical Surgical and Health Sciences, ASUGI, University of Trieste, 34127 Trieste, Italy.
Hypokinesia triggers oxidative stress and accelerates the turnover of the glutathione system via the γ-glutamyl cycle. Our study aimed to identify the regulatory checkpoints controlling intracellular glutathione levels. We measured the intermediate substrates of the γ-glutamyl cycle in erythrocytes from 19 healthy young male volunteers before and during a 10-day experimental bed rest.
View Article and Find Full Text PDFSci Rep
January 2025
School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
To investigate the changes in the strength and deformation of the blast load-damaged sandstone roof plate under cyclic loading and unloading conditions at different confining pressures, a triaxial loading device was used to carry out graded cyclic unloading tests on specimens with different degrees of damage, and the test results were summarized. The effects of blast-load-induced damage, confining pressure and loading stage on the strength, cohesion, internal friction angle, residual strain and volumetric strain were analyzed. (1) Compared with that of the undamaged specimen at a confining pressure of 0 MPa, the peak stress reductions in the vibration-damaged and blast-damaged specimens were 4.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
College of Electrical and Information Engineering, SANYA Offshore Oil and Gas Research Institute, Northeast Petroleum University, Daqing 163318, China.
Integrating ZnS:Cu@AlO/polydimethylsiloxane (PDMS) flexible matrices with optical fibers is crucial for the development of practical passive sensors. However, the fluorescence coupling efficiency is constrained by the small numerical aperture of the fiber, leading to a reduction in sensor sensitivity. To mitigate this limitation, a microsphere lens was fabricated at the end of the multimode fiber, which resulted in a 21.
View Article and Find Full Text PDFPLoS One
December 2024
School of Architecture and Civil Engineering, Xi'an University of Science and Technology, Xi'an, China.
Understanding he impact of dry-wet and freeze-thaw cycles on the mechanical properties of unloaded damaged rock masses in reservoir bank slopes is crucial for revealing the deformation and failure mechanisms in artificially excavated slope rock masses within fluctuation zones. To address, the study focuses on unloaded damaged samples subjected to excavation disturbances, conducting various cycles of dry-wet and freeze-thaw treatment along with uniaxial and triaxial re-loading tests. A damage statistical constitutive model was established based on the experimental results and validated using numerical simulation methods.
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