17 research outputs found
Water sorption-induced crystallization, structural relaxations and strength analysis of relaxation times in amorphous lactose/whey protein systems
Water sorption-induced crystallization, α-relaxations and relaxation times of freeze-dried lactose/whey protein isolate (WPI) systems were studied using dynamic dewpoint isotherms (DDI) method and dielectric analysis (DEA), respectively. The fractional water sorption behavior of lactose/WPI mixtures shown at aw ≤ 0.44 and the critical aw for water sorption-related crystallization (aw(cr)) of lactose were strongly affected by protein content based on DDI data. DEA results showed that the α-relaxation temperatures of amorphous lactose at various relaxation times were affected by the presence of water and WPI. The α-relaxation-derived strength parameter (S) of amorphous lactose decreased with aw up to 0.44 aw but the presence of WPI increased S. The linear relationship for aw(cr) and S for lactose/WPI mixtures was also established with R2 > 0.98. Therefore, DDI offers another structural investigation of water sorption-related crystallization as governed by aw(cr), and S may be used to describe real time effects of structural relaxations in noncrystalline multicomponent solids
The efficacy of different training programs guided by cardiopulmonary exercise test goals for the treatment of male patients with chronic obstructive pulmonary disease
To explore the therapeutic effect of aerobic exercise nursing plans
based on target heart rate in cardiopulmonary exercise tests on male patients
with chronic obstructive pulmonary disease. This study recruited 90 male patients
with chronic obstructive pulmonary disease who met specific screening criteria
and were evenly divided into a control group and an experimental group based on a
random number table. The control group received respiratory training based on the
target heart rate in the cardiopulmonary exercise test, while the experimental
group received aerobic exercise based on the target heart rate in the
cardiopulmonary exercise test. Both groups received 12 weeks of exercise each.
Cardiopulmonary function tests showed that peak oxygen consumption (peak
VO2), anaerobic threshold (AT), forced expiratory volume in the first second
(FEV1), forced vital capacity (FVC), and the FEV1/FVC ratio in the test group
were significantly higher than those in the control group (p < 0.05);
furthermore, the carbon dioxide ventilation equivalent (VE/VCO2) slope was
significantly lower than that in the control group (p < 0.05). The
6MWT of the test group was significantly higher than that in the control group
(p < 0.05). The CAT score, Borg score and scores related to the
symptoms, activities, and impacts related to quality-of-life were significantly
reduced after intervention (p < 0.05). Aerobic exercise based on
cardiopulmonary exercise testing can improve the health status, quality of life
and prognosis of COPD patients
Sustained Effects of High-Intensity Interval Exercise and Moderate-Intensity Continuous Exercise on Inhibitory Control
This study examined the immediate and sustained effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) bouts on inhibitory control in young adults. Participants (n = 41) engaged in (1) a session of HIIE, involving 10 one-minute runs on a treadmill at an intensity targeting 85–90% HRmax interspersed with self-paced walking at 60% HRmax; (2) a session of MICE, involving a 20 min run on a treadmill at an intensity of 60–70% HRmax; and (3) a control session, involving 24 min of resting on separate days in a counterbalanced order. Using a flanker task, inhibitory control was assessed before the intervention (t0), immediately after the session (t1), and then at 30 min (t2), 60 min (t3), and 90 min (t4) after the session. During the flanker task, the response time (RT) for incongruent trials immediately after HIIE was significantly shortened compared to that before exercise. This shortened RT was sustained for 90 min post-exercise during recovery from HIIE. Interference scores of RT were also reduced after HIIE, benefitting inhibitory control, and were maintained for 90 min post-exercise. Reduced accuracy interference scores were recorded following HIIE compared to the control session. Improvements in inhibitory control elicited by HIIE were sustained for at least 90 min post-exercise. In contrast, an improvement in inhibitory control was not observed during the MICE session. HIIE might represent a time-efficient approach for enhancing inhibitory control
Physical activity on executive function in sedentary individuals: Systematic review and meta-analysis of randomized controlled trials.
Physical activity has been demonstrated to promote cognitive performance. However, the relationship between physical activity and executive function (EF) in sedentary individuals is not fully understood. This meta-analysis examined the impact of physical activity on EF in sedentary individuals and evaluated potential moderators of the relationship between physical activity and EF. In accordance with the PRISMA guidelines, the electronic databases MEDLINE, Embase, PsycINFO and Web of Science were searched. Included studies had to report sedentary individuals randomized to either a physical activity group or a control group. Subgroup analyses of EF sub-domains, exercise prescription and age were conducted alongside the overall meta-analysis. Thirteen RCT studies were included, with a total of 752 participants. Results showed a small to moderate beneficial effect of physical activity on EF (SMD = 0.24, 95% CI 0.08 to 0.40). In subgroup analysis by EF sub-domains, physical activity enhanced inhibitory control (SMD = 0.38, 95% CI 0.12 to 0.63) and working memory (SMD = 0.22, 95% CI -0.05 to 0.49), but not cognitive flexibility (SMD = 0.11, 95% CI -0.18 to 0.41). Interventions with an intervention length > 12 weeks improved overall EF (SMD = 0.26, 95% CI 0.06 to 0.46), but intervention length ≤ 12 weeks did not (SMD = 0.20, 95% CI -0.08 to 0.47). Interventions with session time ≥ 45 minutes improved overall EF (SMD = 0.47, 95% CI 0.22 to 0.77), but session time < 45 minutes did not (0.17, 95% CI -0.11 to 0.44). Physical activity improves EF for older adults (age ≥ 60 years) (SMD = 0.25, 95% CI 0.08 to 0.42), but not for younger individuals (age < 60 years) (SMD = 0.17, 95% CI -0.25 to 0.59). Overall, physical activity has a beneficial effect on EF in sedentary individuals, although the influence may be domain specific and influenced by exercise prescription and age. These findings have practical implications for those seeking to improve EF in sedentary individuals through physical activity
Effects of Acute Exercise on Cognitive Flexibility in Young Adults with Different Levels of Aerobic Fitness
This study aimed to evaluate the effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on cognitive flexibility in young adults with differing levels of aerobic fitness. Sixty-six young adults were grouped into high- and low-fit groups based on their final running distance on the 20 m Progressive Aerobic Cardiovascular Endurance Run (PACER) test. Individuals participated in a 10 min HIIE, a 20 min HIIE, a 20 min MICE, and a control session (reading quietly in a chair) in a counterbalanced order. The more-odd shifting task was completed before and approximately 5 min after each intervention to assess cognitive flexibility. The results showed that young adults with a high fitness level gained greater benefits in terms of switch cost from the 20 min HIIE, while low-fitness participants benefited more from the 10 min HIIE and the 20 min MICE. These findings suggest that aerobic fitness may influence the effect of acute HIIE and MICE on cognitive flexibility. Young adults should consider individual fitness level when adopting time-effective and appropriate exercise routines to improve cognitive flexibility
Influence of Film Quality on Power Conversion Efficiency in Perovskite Solar Cells
Organic-inorganic perovskite solar cells (PSCs) are a high-efficiency, low-cost form of solar technology because of the abundance of useful materials and a simple fabrication procedure relative to other photovoltaic devices. Furthermore, the perovskite material shows decent electron and hole mobilities, a wide absorption range, and long exciton diffusion length. So far, many groups have focused on the research of perovskite thin-film solar cells, and these perovskite solar cells have been deemed to be one of the leading next generation photovoltaic technologies. However, there are several problems that restrict the enhancement of perovskite solar cell performance such as their poor uniformity and low crystallinity. Herein we summarize and discuss the role of film quality on power conversion efficiency, and effect of fabrication condition on the light absorbance of perovskite film
Highly Hydrophilic Zirconia Composite Anion Exchange Membrane for Water Electrolysis and Fuel Cells
To prepare anion exchange membranes with high water electrolysis
and single fuel cell performance, an inorganic–organic composite
(IOC) strategy with click cross-linked membranes coated with different
contents of hydrophilic polar nanozirconia is proposed to fabricate
composite membranes (CM) PBP-SH-Zrx. The performance test results
showed that the CM PBP-SH-Zr4 not only has good through-plane ionic
conductivity (167.7 mS cm–1, 80 °C), but also
exhibits satisfactory dimensional stability (SR 16.5%, WU 206.4%,
80 °C), especially demonstrating excellent alkaline stability
with only 16% degradation (2 M NaOH for 2200 h). In water electrolysis,
the “microgap” between the membrane and catalyst layer
(solid–solid interface) is alleviated, and the membrane electrode
assembly (MEA) interfacial compatibility (liquid–solid–solid
interface) is enhanced. The CM PBP-SH-Zr4 showed the lowest charge
transfer resistance (Rct, 0.037 Ω cm2)
and a high current density of 2.5 A cm–2 at 2.2
V, while the voltage drop was 0.361 mV h–1 after
360 h of endurance (six start–stop cycles) at 60 °C and
500 mA cm–2, proving a good water electrolysis durability.
Moreover, an acceptable peak power density of 0.464 W cm–2 at 80 °C is achieved in a H2/O2 fuel
cell with a PBP-SH-Zr4-AEM. Therefore, the IOC strategy can enhance
the membrane’s comprehensive performance and interface compatibility
of MEA and may promote the development of anion exchange membranes
(AEMs) for water electrolysis and fuel cells