| 1. |
- Garthwaite, Taru, et al.
(författare)
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Associations of sedentary time, physical activity, and fitness with muscle glucose uptake in adults with metabolic syndrome
- 2022
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - West Sussex : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 33:3, s. 353-358
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of the study was to investigate the associations of sedentary time, physical activity, and cardiorespiratory fitness with skeletal muscle glucose uptake (GU). Methods: Sedentary time and physical activity were measured with accelerometers and VO2max with cycle ergometry in 44 sedentary adults with metabolic syndrome. Thigh muscle GU was determined with [18F]FDG-PET imaging. Results: Sedentary time (β = −0.374), standing (β = 0.376), steps (β = 0.351), and VO2max (β = 0.598) were associated with muscle GU when adjusted for sex, age, and accelerometer wear time. Adjustment for body fat-% turned all associations non-significant. Conclusion: Body composition is a more important determinant of muscle GU in this population than sedentary time, physical activity, or fitness. © 2022 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.
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| 2. |
- Garthwaite, Taru, et al.
(författare)
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Standing is associated with insulin sensitivity in adults with metabolic syndrome
- 2021
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Ingår i: Journal of Science and Medicine in Sport. - Chatswood : Elsevier. - 1440-2440 .- 1878-1861. ; 24:12, s. 1255-1260
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To determine how components of accelerometer-measured sedentary behavior (SB) and physical activity (PA), and fitness are associated with insulin sensitivity in adults with metabolic syndrome. Design: Cross-sectional. Methods: Target population was middle-aged (40–65 years) sedentary adults with metabolic syndrome. SB, breaks in SB, standing, and PA were measured for four weeks with hip-worn accelerometers. VO2max (ml/min/kg) was measured with maximal cycle ergometry. Insulin sensitivity was determined by hyperinsulinaemic-euglycaemic clamp (M-value) and fasting blood sampling (HOMA-IR, insulin). Multivariable regression was used for analyses. Results: Sixty-four participants (37 women; 58.3 [SD 6.8] years) were included. Participants spent 10.0 (1.0) h sedentary, 1.8 (0.6) h standing, and 2.7 (0.6) h in PA and took 5149 (1825) steps and 29 (8) breaks daily. In sex-, age- and accelerometer wear time-adjusted model SB, standing, steps and VO2max were associated with M-value (β = −0.384; β = 0.400; β = 0.350; β = 0.609, respectively), HOMA-IR (β = 0.420; β = −0.548; β = −0.252; β = −0.449), and insulin (β = 0.433; β = −0.541; β = −0.252; β = −0.453); all p-values < 0.05. Breaks associated only with M-value (β = 0.277). When further adjusted for body fat %, only standing remained significantly associated with HOMA-IR (β = −0.381) and insulin (β = −0.366); significance was maintained even when further adjusted for SB, PA and fitness. Light and moderate-to-vigorous PA were not associated with insulin sensitivity. Conclusions: Standing is associated with insulin sensitivity markers. The association with HOMA-IR and insulin is independent of adiposity, PA, SB and fitness. Further studies are warranted, but these findings encourage replacing sitting with standing for potential improvements in insulin sensitivity in adults at increased type 2 diabetes risk. © 2021 The Authors.
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| 3. |
- Haapala, Eero A., et al.
(författare)
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Association between cardiorespiratory fitness and metabolic health in overweight and obese adults
- 2022
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Ingår i: Journal of Sports Medicine and Physical Fitness. - Turin : Edizioni Minerva Medica. - 0022-4707 .- 1827-1928. ; 62:11, s. 1526-1533
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cardiorespiratory fitness (CRF) has been inversely associated with insulin resistance and clustering of cardiometabolic risk factors among overweight and obese individuals. However, most previous studies have scaled CRF by body mass (BM) possibly inflating the association between CRF and cardiometabolic health. We investigated the associations of peak oxygen uptake (V?O2peak) and peak power output (Wpeak) scaled either by BM-1, fat free mass (FFM-1), or by allometric methods with individual cardiometabolic risk factors and clustering of cardiometabolic risk factors in 55 overweight or obese adults with metabolic syndrome. METHODS: VO2peak and Wpeak were assessed by a maximal cycle ergometer exercise test. FFM was measured by air displacement plethysmo- graph and glucose, insulin, HbA1c, triglycerides, and total, LDL, and HDL cholesterol from fasting blood samples. HOMA-IR and metabolic syndrome score (MetS) were computed. RESULTS: VO2peak and Wpeak scaled by BM-1 were inversely associated with insulin (β=-0.404 to -0.372, 95% CI: -0.704 to -0.048), HOMAIR (β=-0.442 to -0.440, 95% CI: -0.762 to -0.117), and MetS (β=-0.474 to -0.463, 95% CI: -0.798 to -0.127). Other measures of CRF were not associated with cardiometabolic risk factors. CONCLUSIONS: Our results suggest that using BM-1 as a scaling factor confounds the associations between CRF and cardiometabolic risk in overweight/obese adults with the metabolic syndrome. © 2022 EDIZIONI MINERVA MEDICA.
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| 4. |
- Hartmann, Sean J., et al.
(författare)
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Electrochemical Properties of Nitrogen and Oxygen Doped Reduced Graphene Oxide
- 2020
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Ingår i: Energies. - : MDPI. - 1996-1073. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Carbon nanostructures are promising electrode materials for energy storage devices because of their unique physical and chemical properties. Modification of the surface improves the electrochemical properties of those materials because of the changes in morphology, diffusion properties, and inclusion of additional contributions to redox processes. Oxygen-containing functional groups and nitrogen doped into the carbon matrix significantly contribute to the electrochemical behavior of reduced graphite oxide (RGO). In this work, RGO was synthesized during hydrothermal treatment of graphite oxide with a hydrazine sulfate aqueous solution. Different amounts of hydrazine sulfate were used to synthesize RGO with different nitrogen contents in the structure, and the same synthesis conditions made it possible to obtain a material with a similar composition of oxygen-containing functional groups. The materials with different nitrogen concentrations and similar amounts of oxygen were compared as electrode materials for a supercapacitor and as a negative electrode material for a Li-ion battery. It was shown that the presence of oxygen-containing functional groups has the greatest influence on the behavior and efficiency of supercapacitor electrode materials, while nitrogen atoms embedded in the graphene lattice play the largest role in lithium intercalation.
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| 5. |
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| 6. |
- Iurchenkova, Anna A., 1997-, et al.
(författare)
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The effect of the pyrolysis temperature and biomass type on the biocarbons characteristics
- 2023
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Ingår i: ChemSusChem. - : John Wiley & Sons. - 1864-5631 .- 1864-564X. ; , s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- The conversion of biomass and natural wastes into carbon-based materials for various applications such as catalysts and energy-related materials is a fascinating and sustainable approach emerged during recent years. Precursor nature and characteristics are complex, hence, their effect on the properties of resulting materials is still unclear. In this work, we have investigated the effect of different precursors and pyrolysis temperature on the properties of produced carbon materials and their potential application as negative electrode materials in Li-ion batteries. Three biomasses, lignocellulosic brewery spent grain from a local brewery, catechol-rich lignin and tannins, were selected for investigations. We show that such end-product carbon characteristic as functional and elemental composition, porosity, specific surface area, defectiveness level, and morphology strictly depend on the precursor composition, chemical structure, and pyrolysis temperature. The electrochemical characteristics of produced carbon materials are correlate with the characteristics of the produced materials. A higher pyrolysis temperature is shown to be favourable for production of carbon material for the Li-ion battery application in terms of both specific surface area and long-term cycling stability.
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| 7. |
- Laakso, Ekaterina, et al.
(författare)
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Aging mechanisms of NMC811/Si-Graphite Li-ion batteries
- 2024
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Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 599
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Tidskriftsartikel (refereegranskat)abstract
- Electrode degradation processes at various Li-ion batteries' state-of-health (SoH 100 %, 80 %, 50 %, and 30 %) and cycling temperatures (5°C, 23°C, and 45°C) were investigated. For this purpose, the standard format of Li-ion cylindrical 18,650 batteries with Si-Graphite negative and LiNi0⋅8Co0⋅1Mn0⋅1O2 (NMC811) positive electrodes were cycled with registering battery parameters and the electrochemical impedance spectrum were recorded after every 200 cycles. Once reaching their end-of-life, electrodes from cycled batteries were subjected to post-mortem analysis. NMC811 positive electrode was observed to crack during the charge and discharge processes, suffered by irreversible phase transition, transition metal dissolution, cathode electrolyte interphase growth, and cation mixing. The Si-Graphite negative electrode material was also affected by crack formation, layer exfoliation, solid electrolyte interphase (SEI) recompositing, Li dendrite growth, transition metal contamination, and Si dissolution. Degradation of components leads to an increase of the contact resistance, Li+ diffusion limitations, reduction of active materials participating in Li-ion storage and, as a result, capacity fade that finally rendered the battery utilization unfeasible. Degradation processes can be detected by capacity fade and impedance growth of the full battery. High temperature accelerates electrode degradation processes when low temperature leads to SEI and Li dendrite growth.
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| 8. |
- Laine, Saara, et al.
(författare)
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Relationship between liver fat content and lifestyle factors in adults with metabolic syndrome
- 2022
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Ingår i: Scientific Reports. - London : Nature Publishing Group. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the associations between liver fat content (LFC), sedentary behaviour (SB), physical activity (PA), fitness, diet, body composition, and cardiometabolic risk factors in adults with metabolic syndrome. A total of 44 sedentary adults (mean age 58 [SD 7] years; 25 women) with overweight or obesity participated. LFC was assessed with magnetic resonance spectroscopy and imaging, SB and PA with hip-worn accelerometers (26 [SD 3] days), fitness by maximal bicycle ergometry, body composition by air displacement plethysmography and nutrient intake by 4-day food diaries. LFC was not independently associated with SB, PA or fitness. Adjusted for sex and age, LFC was associated with body fat%, body mass index, waist circumference, triglycerides, alanine aminotransferase, and with insulin resistance markers. There was and inverse association between LFC and daily protein intake, which persisted after further adjusment with body fat%. LFC is positively associated with body adiposity and cardiometabolic risk factors, and inversely with daily protein intake. SB, habitual PA or fitness are not independent modulators of LFC. However, as PA is an essential component of healthy lifestyle, it may contribute to liver health indirectly through its effects on body composition in adults with metabolic syndrome. © 2022, The Author(s).
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| 9. |
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| 10. |
- Norha, Jooa, et al.
(författare)
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Effects of reducing sedentary behavior on cardiorespiratory fitness in adults with metabolic syndrome : A 6-month RCT
- 2023
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - Chichester : Wiley-Blackwell Publishing Inc.. - 0905-7188 .- 1600-0838. ; 33:8, s. 1452-1461
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Tidskriftsartikel (refereegranskat)abstract
- Introduction:Poor cardiorespiratory fitness (CRF) is associated with adverse health outcomes. Previous observational and cross-sectional studies have suggested that reducing sedentary behavior (SB) might improve CRF. Therefore, we investigated the effects of a 6-month intervention of reducing SB on CRF in 64 sedentary inactive adults with metabolic syndrome in a non-blind randomized controlled trial.Materials and Methods:In the intervention group (INT, n = 33), the aim was to reduce SB by 1 h/day for 6 months without increasing exercise training. Control group (CON, n = 31) was instructed to maintain their habitual SB and physical activity. Maximal oxygen uptake (VO2max) was measured by maximal graded bicycle ergometer test with respiratory gas measurements. Physical activity and SB were measured during the whole intervention using accelerometers.Results:Reduction in SB did not improve VO2max statistically significantly (group × time p > 0.05). Maximal absolute power output (Wmax) did not improve significantly but increased in INT compared to CON when scaled to fat free mass (FFM) (at 6 months INT 1.54 [95% CI: 1.41, 1.67] vs. CON 1.45 [1.32, 1.59] Wmax/kgFFM, p = 0.036). Finally, the changes in daily step count correlated positively with the changes in VO2max scaled to body mass and FFM (r = 0.31 and 0.30, respectively, p < 0.05).Discussion:Reducing SB without adding exercise training does not seem to improve VO2max in adults with metabolic syndrome. However, succeeding in increasing daily step count may increase VO2max. © 2023 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.
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