| 3. |
- Elia, Antonis, Dr, et al.
(författare)
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Cerebral, cardiac and skeletal muscle stress associated with a series of static and dynamic apnoeas
- 2022
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 32:1, s. 233-241
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This study sought to explore, for the first time, the effects of repeated maximal static and dynamic apnoeic attempts on the physiological milieu by assessing cerebral, cardiac and striatal muscle stress-related biomarkers in a group of elite breath-hold divers (EBHD). Methods: Sixteen healthy males were recruited (EBHD = 8; controls = 8). On two separate occasions, EBHD performed two sets of five repeated maximal static apnoeas (STA) or five repeated maximal dynamic apnoeas (DYN). Controls performed a static eupnoeic protocol to negate any effects of water immersion and diurnal variation on haematology (CTL). Venous blood samples were drawn at 30, 90, and 180 min after each protocol to determine S100β, neuron-specific enolase (NSE), myoglobin, and high sensitivity cardiac troponin T (hscTNT) concentrations. Results: S100β and myoglobin concentrations were elevated following both apnoeic interventions (p < 0.001; p ≤ 0.028, respectively) but not after CTL (p ≥ 0.348). S100β increased from baseline (0.024 ± 0.005 µg/L) at 30 (STA, +149%, p < 0.001; DYN, +166%, p < 0.001) and 90 min (STA, +129%, p < 0.001; DYN, +132%, p = 0.008) following the last apnoeic repetition. Myoglobin was higher than baseline (22.3 ± 2.7 ng/ml) at 30 (+42%, p = 0.04), 90 (+64%, p < 0.001) and 180 min (+49%, p = 0.013) post-STA and at 90 min (+63%, p = 0.016) post-DYN. Post-apnoeic S100β and myoglobin concentrations were higher than CTL (STA, p < 0.001; DYN, p ≤ 0.004). NSE and hscTNT did not change from basal concentrations after the apnoeic (p ≥ 0.146) nor following the eupnoeic (p ≥ 0.553) intervention. Conclusions: This study suggests that a series of repeated maximal static and dynamic apnoeas transiently disrupt the blood-brain barrier and instigate muscle injury but do not induce neuronal-parenchymal damage or myocardial damage.
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| 4. |
- Elkadeem, M. R., et al.
(författare)
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Geospatial-assisted multi-criterion analysis of solar and wind power geographical-technical-economic potential assessment
- 2022
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 322
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Tidskriftsartikel (refereegranskat)abstract
- Amid the increasing electricity demand, energy crisis and pollution, the transition to renewable energy (RE) is becoming a preoccupation and major global challenge due to the multidimensional and intricate problem of RE planning. In Egypt, about 90% of gross power generation comes from carbon-intensive power plants (natural gas and coal). Here, we propose a novel geospatial-decision-making model aimed at geographical-technical–economic potential mapping and assessment of solar photovoltaic (PV) and onshore wind turbine (WT) power plants at a high level of resolution (1 km2) in Egypt. We identify the locations suitable for PV and WT development considering sixteen restrictive and contradictory evaluation criteria. These locations have been further analyzed to estimate how much energy generation is available and at what energy cost. The analysis identifies Middle-Upper Egypt and Suez Canal as hosting the majority of highly suitable locations for PV and WT power plants, respectively. Our finding reveals that the proper planning on RE projects at the proposed optimum locations could support the country's energy mix with a sizable 32% share of the projected country's electricity consumption from PV and 50% share from WT, by 2030. Furthermore, we show that the investment opportunities of PV and WT generation are potentially attractive with affordable competitive prices estimated at 57.84 $/MWh and 32.36 $/MWh, respectively, against conventional generation for today and the future. We anticipate that our results will provide valuable support in realizing Egypt's vision for sustainable electricity generation and in keeping abreast of the global transformation in power systems being witnessed. Ultimately, the method's relevance extends beyond the geographical boundaries of the present territory; it features a strategic, clear and reproducible approach that may be applied to a larger area or continent, provided the necessary input data and criteria are introduced.
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