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- Lees, Matthew J., et al.
(författare)
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Novel Essential Amino Acid Supplements Following Resistance Exercise Induce Aminoacidemia and Enhance Anabolic Signaling Irrespective of Age : A Proof-of-Concept Trial
- 2020
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 12:7, s. 2067-
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the effects of ingesting a leucine-enriched essential amino acid (EAA) gel alone or combined with resistance exercise (RE) versus RE alone (control) on plasma aminoacidemia and intramyocellular anabolic signaling in healthy younger (28 +/- 4 years) and older (71 +/- 3 years) adults. Blood samples were obtained throughout the three trials, while muscle biopsies were collected in the postabsorptive state and 2 h following RE, following the consumption of two 50 mL EAA gels (40% leucine, 15 g total EAA), and following RE with EAA (combination (COM)). Protein content and the phosphorylation status of key anabolic signaling proteins were determined via immunoblotting. Irrespective of age, during EAA and COM peak leucinemia (younger: 454 +/- 32 mu M and 537 +/- 111 mu M; older: 417 +/- 99 mu M and 553 +/- 136 mu M) occurred similar to 60-120 min post-ingestion (younger: 66 +/- 6 min and 120 +/- 60 min; older: 90 +/- 13 min and 78 +/- 12 min). In the pooled sample, the area under the curve for plasma leucine and the sum of branched-chain amino acids was significantly greater in EAA and COM compared with RE. For intramyocellular signaling, significant main effects were found for condition (mTOR (Ser2481), rpS6 (Ser235/236)) and age (S6K1 (Thr421/Ser424), 4E-BP1 (Thr37/46)) in age group analyses. The phosphorylation of rpS6 was of similar magnitude (similar to 8-fold) in pooled and age group data 2 h following COM. Our findings suggest that a gel-based, leucine-enriched EAA supplement is associated with aminoacidemia and a muscle anabolic signaling response, thus representing an effective means of stimulating muscle protein anabolism in younger and older adults following EAA and COM.
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2. |
- Fox, Stuart, et al.
(författare)
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Airborne validation of radiative transfer modelling of ice clouds at millimetre and sub-millimetre wavelengths
- 2019
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Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 12:3, s. 1599-1617
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Tidskriftsartikel (refereegranskat)abstract
- The next generation of European polar orbiting weather satellites will carry a novel instrument, the Ice Cloud Imager (ICI), which uses passive observations between 183 and 664 GHz to make daily global observations of cloud ice. Successful use of these observations requires accurate modelling of cloud ice scattering, and this study uses airborne observations from two flights of the Facility for Airborne Atmospheric Measurements (FAAM) BAe 146 research aircraft to validate radiative transfer simulations of cirrus clouds at frequencies between 325 and 664 GHz using the Atmospheric Radiative Transfer Simulator (ARTS) and a state-of-the-art database of cloud ice optical properties. Particular care is taken to ensure that the inputs to the radiative transfer model are representative of the true atmospheric state by combining both remote-sensing and in situ observations of the same clouds to create realistic vertical profiles of cloud properties that are consistent with both observed particle size distributions and bulk ice mass. The simulations are compared to measurements from the International Submillimetre Airborne Radiometer (ISMAR), which is an airborne demonstrator for ICI. It is shown that whilst they are generally able to reproduce the observed cloud signals, for a given ice water path (IWP) there is considerable sensitivity to the cloud microphysics, including the distribution of ice mass within the cloud and the ice particle habit. Accurate retrievals from ICI will therefore require realistic representations of cloud microphysical properties.
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3. |
- Linpé, W., et al.
(författare)
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An electrochemical cell for 2-dimensional surface optical reflectance during anodization and cyclic voltammetry
- 2020
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 91:4
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Tidskriftsartikel (refereegranskat)abstract
- We have developed an electrochemical cell for in situ 2-Dimensional Surface Optical Reflectance (2D-SOR) studies during anodization and cyclic voltammetry. The 2D-SOR signal was recorded from electrodes made of polycrystalline Al, Au(111), and Pt(100) single crystals. The changes can be followed at a video rate acquisition frequency of 200 Hz and demonstrate a strong contrast between oxidizing and reducing conditions. Good correlation between the 2D-SOR signal and the anodization conditions or the cyclic voltammetry current is also observed. The power of this approach is discussed, with a focus on applications in various fields of electrochemistry. The combination of 2D-SOR with other techniques, as well as its spatial resolution and sensitivity, has also been discussed.
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4. |
- Elia, Antonis, et al.
(författare)
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Physiology, pathophysiology and (mal)adaptations to chronic apnoeic training: a state-of-the-art review
- 2021
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Ingår i: European Journal of Applied Physiology. - : Springer. - 1439-6319 .- 1439-6327. ; 121:6, s. 1543-1566
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Tidskriftsartikel (refereegranskat)abstract
- Breath-hold diving is an activity that humans have engaged in since antiquity to forage for resources, provide sustenance and to support military campaigns. In modern times, breath-hold diving continues to gain popularity and recognition as both a competitive and recreational sport. The continued progression of world records is somewhat remarkable, particularly given the extreme hypoxaemic and hypercapnic conditions, and hydrostatic pressures these athletes endure. However, there is abundant literature to suggest a large inter-individual variation in the apnoeic capabilities that is thus far not fully understood. In this review, we explore developments in apnoea physiology and delineate the traits and mechanisms that potentially underpin this variation. In addition, we sought to highlight the physiological (mal)adaptations associated with consistent breath-hold training. Breath-hold divers (BHDs) are evidenced to exhibit a more pronounced diving-response than non-divers, while elite BHDs (EBHDs) also display beneficial adaptations in both blood and skeletal muscle. Importantly, these physiological characteristics are documented to be primarily influenced by training-induced stimuli. BHDs are exposed to unique physiological and environmental stressors, and as such possess an ability to withstand acute cerebrovascular and neuronal strains. Whether these characteristics are also a result of training-induced adaptations or genetic predisposition is less certain. Although the long-term effects of regular breath-hold diving activity are yet to be holistically established, preliminary evidence has posed considerations for cognitive, neurological, renal and bone health in BHDs. These areas should be explored further in longitudinal studies to more confidently ascertain the long-term health implications of extreme breath-holding activity.
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5. |
- Harlow, J., et al.
(författare)
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Mapped regular pavings
- 2012
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Ingår i: Reliable Computing. - 1385-3139 .- 1573-1340. ; 16, s. 252-282
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Tidskriftsartikel (refereegranskat)abstract
- A regular paving is a finite succession of bisections that partition a root box x in ℝ d into sub-boxes using a binary tree-based data structure. We extend regular pavings to mapped regular pavings which map sub-boxes in a regular paving of x to elements in some set Y. Arithmetic operations defined on Y can be extended point-wise over x and carried out in a computationally efficient manner using Y-mapped regular pavings of x. The efficiency of this arithmetic is due to recursive algorithms on the algebraic structure of finite rooted binary trees that are closed under union operations. Our arithmetic has many applications in function approximation using tree based inclusion algebras and statistical set-processing.
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7. |
- Wallander, Harald J., et al.
(författare)
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Dynamic Behavior of Tin at Platinum Surfaces during Catalytic CO Oxidation
- 2023
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 13:24, s. 16158-16167
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Tidskriftsartikel (refereegranskat)abstract
- Platinum-tin surfaces are active for CO oxidation, but their activity and the effects of tin oxide phases that form under reaction conditions are poorly understood. We have studied surface alloys of tin prepared on platinum single crystals during catalytic CO oxidation using near-ambient-pressure X-ray photoemission spectroscopy. On the flat terraces of Sn/Pt(111), a wetting layer of Sn(II) surface oxide forms, while on the stepped Sn/Pt(223) surface, 3D clusters of Sn(IV) oxide are formed. Oxidation of tin by O2 competes with the reduction of the oxides by CO under reaction conditions. Oxides that do not completely cover the surface can be reduced to metallic tin, while a fully covering layer of Sn(II) oxide cannot, showing the importance of oxide edge sites for the reduction process. The samples where 2D oxide layers are formed show a higher CO oxidation activity than for pure platinum at low temperatures, while the Sn(IV) oxide clusters on the stepped surfaces do not affect the measured CO oxidation rate. We therefore identify 2D Sn(II) oxide as an active phase for CO oxidation. While oxide island edges appear to make only minor contributions to conversion under these conditions, reactions at these sites play a major role in determining the phases present and their transformations.
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8. |
- Weber, Tim, et al.
(författare)
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Operando Stability Studies of Ultrathin Single-Crystalline IrO2(110) Films under Acidic Oxygen Evolution Reaction Conditions
- 2021
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 11:20, s. 12651-12660
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Tidskriftsartikel (refereegranskat)abstract
- The anodic corrosion behavior of 50 Å thick single-crystalline IrO2(110) films supported on slightly bulk-reduced TiO2(110) single crystals is studied during acidic water splitting by a unique combination of operando techniques, namely, synchrotron-based high-energy X-ray reflectivity (XRR) and surface X-ray diffraction (SXRD) together with highly sensitive inductively coupled plasma mass spectrometry (ICP-MS). Corrosion-induced structural and morphological changes of the IrO2(110) model electrode can be followed on the atomic scale by operando XRR and SXRD that are supplemented with ex situ scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS), whereas with ICP-MS, the corrosion rate can be quantified down to 1 pg·cm-2·s-1 with a time resolution on the second scale. The operando synchrotron-based X-ray scattering techniques are surprisingly sensitive to Ir corrosion of about 0.10 monolayer of IrO2(110) in ∼26 h, i.e., 0.4 pg·cm-2·s-1. The present study demonstrates that single-crystalline IrO2(110) films are much more stable than hitherto expected. Although the dissolution rate is very small, ICP-MS experiments reveal a significantly higher dissolution rate than the operando high-energy XRR/SXRD experiments. These differences in dissolution rate are suggested to be due to the different modi operandi encountered in ICP-MS (dynamic) and operando XRR/SXRD experiments (steady state), a fact that may need to be considered when hydrogen production is coupled to intermittent energy sources such as renewables.
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9. |
- Zetterholm, Magnus, et al.
(författare)
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Antioch (Syrian)
- 2010
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Ingår i: The Eerdmans Dictionary of Early Judaism. - 9780802825490 ; , s. 336-338
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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10. |
- Zetterholm, Magnus, et al.
(författare)
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Damascus
- 2010
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Ingår i: The Eerdmans Dictionary of Early Judaism. - 9780802825490 ; , s. 509-510
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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