44 research outputs found
Thermoregulatory and cardiovascular responses to creatine, glycerol and alpha lipoic acid in trained cyclists
<p>Abstract</p> <p>Background</p> <p>It has been shown that supplementation with creatine (Cr) and glycerol (Gly), when combined with glucose (Glu) necessary for the enhancement of Cr uptake by skeletal muscle, induces significant improvements in thermoregulatory and cardiovascular responses during exercise in the heat.</p> <p>Purpose</p> <p>To determine whether Cr/Gly-induced thermoregulatory and cardiovascular responses are maintained when the majority (~75%) of the Glu in the Cr/Gly supplement is replaced with the insulintropic agent alpha lipoic acid (Ala).</p> <p>Methods</p> <p>22 healthy endurance trained cyclists were randomly assigned to receive either 20 g/day (4 × 5 g/day) of Cr, 2 g <sup>.</sup>kg<sup>-1</sup> BM per day (4 × 0.5 g <sup>.</sup>kg<sup>-1</sup> BM per day) of Gly and 150 g/day (4 × 37.5 g/day) of Glu or 20 g/day (4 × 5 g/day) of Cr monohydrate, 2 g <sup>.</sup>kg<sup>-1</sup> BM per day (4 × 0.5 g <sup>.</sup>kg<sup>-1</sup> BM per day) of Gly (100 g/day (4 × 25 g/day) of Glu and 1000 mg/day (4 × 250 mg/day) of Ala for 7 days for 7 days. Exercise trials were conducted pre- and post-supplementation and involved 40 min of constant-load cycling exercise at 70% O<sub>2</sub> max by a self-paced 16.1 km time trial at 30°C and 70% relative humidity.</p> <p>Results</p> <p>Median and range values of TBW increased significantly by 2.1 (1.3-3.3) L and 1.8 (0.2-4.6) L in Cr/Gly/Glu and Cr/Gly/Glu/Ala groups respectively (<it>P</it> = 0.03) and of BM not significantly by 1.8 (0.2-3.0) kg and 1.2 (0.5-2.1) kg in Cr/Gly/Glu and in Cr/Gly/Glu/Ala, respectively (<it>P</it> = 0.75). During constant load exercise, heart rate (HR) and core temperature (Tcore) were significantly lower post-supplementation: HR was reduced on average by 3.3 ± 2.1 beats/min and by 4.8 ± 3.3 beats/min (mean ± SD) and Tcore by 0.2 ± 0.1 (mean ± SD) in the Cr/Gly/Glu and Cr/Gly/Glu/Ala, respectively The reduction in HR and Tcore was not significantly different between the supplementation groups.</p> <p>Conclusions</p> <p>In comparison to the established hyper hydrating Cr/Gly/Glu supplement, supplement containing Cr/Gly/Ala and decreased amount of Glu provides equal improvements in thermoregulatory and cardiovascular responses during exercise in the heat.</p
The molecular basis of phosphite and hypophosphite recognition by ABC-transporters
Inorganic phosphate is the major bioavailable form of the essential nutrient phosphorus. However, the concentration of phosphate in most natural habitats is low enough to limit microbial growth. Under phosphate-depleted conditions some bacteria utilise phosphite and hypophosphite as alternative sources of phosphorus, but the molecular basis of reduced phosphorus acquisition from the environment is not fully understood. Here, we present crystal structures and ligand binding affinities of periplasmic binding proteins from bacterial phosphite and hypophosphite ATP-binding cassette transporters. We reveal that phosphite and hypophosphite specificity results from a combination of steric selection and the presence of a P-H…π interaction between the ligand and a conserved aromatic residue in the ligand-binding pocket. The characterisation of high affinity and specific transporters has implications for the marine phosphorus redox cycle, and might aid the use of phosphite as an alternative phosphorus source in biotechnological, industrial and agricultural applications
Identification of plasma and urinary metabolites and catabolites derived from orange juice (poly)phenols: analysis by high-performance liquid chromatography–high-resolution mass spectrometry
Orange juice is a rich source of (poly)phenols, in particular, the flavanones hesperetin-7-O-rutinoside and naringenin-7-O-rutinoside. Following the acute consumption of 500 mL of orange juice containing 398 μmol of (poly)phenols by 12 volunteers, 0–24 h plasma and urine samples were analyzed by targeted high-performance liquid chromatography–high-resolution mass spectrometry in order to identify flavanone metabolites and phenolic acid and aromatic catabolites. A total of 19 flavanone metabolites—comprising di-O-glucuronide, O-glucuronide, O-glucuronyl-sulfate, and sulfate derivatives of hesperetin, naringenin, and eriodictyol—and 65 microbial-derived phenolic catabolites, such as phenylpropanoid, phenylpropionic, phenylacetic, benzoic, and hydroxycarboxylic acids and benzenetriol and benzoylglycine derivatives, including free phenolics and phase II sulfate, glucuronide, and methyl metabolites, were identified or partially identified in plasma and/or urine samples. The data obtained provide a detailed evaluation of the fate of orange juice (poly)phenols as they pass through the gastrointestinal tract and are absorbed into the circulatory system prior to renal excretion. Potential pathways for these conversions are proposed
Sustainable travel behaviour and the widespread impacts on the local economy
Statistics show that unsustainable travel behaviour and global greenhouse gas emissions are growing and due to the perceived indispensable nature of personal travel, shifts to more sustainable modes remain a challenge. Automobility supports sustained local economic growth but also raises issues around safety, health, road fatalities, traffic and congestion, and detrimental environmental impacts. This article addresses the issue of sustainable mobility by investigating how to increase sustainable travel choices and, where this is not possible, ensure existing travel choices and patterns are as environmentally friendly as possible. Existing soft initiatives aimed at increasing sustainable travel behaviour fail to fully acknowledge that travel decisions are made at the individual level and that tailored strategies would be more effective at targeting distinct behavioural patterns. Influencing changes in travel behaviour at the local level demonstrates significant potential where individual behaviour can be influenced if appropriate support at the system level is in place and complies with the needs of individuals. This article demonstrates that, in doing so, this will simultaneously address other areas, such as accessibility, employability, health and sustainable growth, crucial to the establishment and survival of automobility by both supporting local economic growth and achieving reductions in carbon emissions
Dual-driven biodegradable nanomotors for enhanced cellular uptake
Hybrid nano-sized motors with navigation and self-actuation capabilities have emerged as promising nanocarriers for a wide range of delivery, sensing, and diagnostic applications due to their unique ability to achieve controllable locomotion within a complex biological environment such as tissue. However, most current nanomotors typically operate using a single driving mode, whereas propulsion induced by both external and local stimuli could be more beneficial to achieve efficient motility in a biomedical setting. In this work, we present a hybrid nanomotor by functionalizing biodegradable stomatocytes with platinum nanoparticles (Pt NPs). These Pt NPs enable two distinct propulsion mechanisms. First, near-infrared (NIR) laser irradiation causes plasmonic heating, which, due to the asymmetric shape of the stomatocytes, creates a temperature gradient around the nanomotors. Second, the catalytic properties of the Pt NPs allow them to convert hydrogen peroxide into water and oxygen, generating a chemical gradient that serves as an additional driving force. Hydrogen peroxide is thereby locally produced from endogenous glucose by a co-encapsulated enzyme, glucose oxidase. The motile features are employed to achieve enhanced accumulation within tumor cells. This nanomotor design offers a versatile approach for developing dual stimuli-responsive nanomotors that operate more effectively in complex environments.</p
Identification of Plasma and Urinary Metabolites and Catabolites Derived from Orange Juice (Poly)phenols: Analysis by High-Performance Liquid Chromatography–High-Resolution Mass Spectrometry
Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P availability
The filamentous diazotrophic cyanobacterium Trichodesmium is responsible for a significant fraction of marine di-nitrogen (N2) fixation. Growth and distribution of Trichodesmium and other diazotrophs in the vast oligotrophic subtropical gyres is influenced by iron (Fe) and phosphorus (P) availability, while reciprocally influencing the biogeochemistry of these nutrients. Here we use observations across natural inverse gradients in Fe and P in the North Atlantic subtropical gyre (NASG) to demonstrate how Trichodesmium acclimates in situ to resource availability. Transcriptomic analysis identified progressive upregulation of known iron-stress biomarker genes with decreasing Fe availability, and progressive upregulation of genes involved in the acquisition of diverse P sources with decreasing P availability, while genes involved in N2 fixation were upregulated at the intersection under moderate Fe and P availability. Enhanced N2 fixation within the Fe and P co-stressed transition region was also associated with a distinct, consistent metabolic profile, including the expression of alternative photosynthetic pathways that potentially facilitate ATP generation required for N2 fixation with reduced net oxygen production. The observed response of Trichodesmium to availability of both Fe and P supports suggestions that these biogeochemically significant organisms employ unique molecular, and thus physiological responses as adaptations to specifically exploit the Fe and P co-limited niche they construct
Randomised clinical study: inulin short-chain fatty acid esters for targeted delivery of short-chain fatty acids to the human colon
SUMMARY Background Short-chain fatty acids (SCFA) produced through fermentation of nondigestible carbohydrates by the gut microbiota are associated with positive metabolic effects. However, well-controlled trials are limited in humans
Metaverse beyond the hype: Multidisciplinary perspectives on emerging challenges, opportunities, and agenda for research, practice and policy
The metaverse has the potential to extend the physical world using augmented and virtual reality technologies allowing users to seamlessly interact within real and simulated environments using avatars and holograms. Virtual environments and immersive games (such as, Second Life, Fortnite, Roblox and VRChat) have been described as antecedents of the metaverse and offer some insight to the potential socio-economic impact of a fully functional persistent cross platform metaverse. Separating the hype and “meta…” rebranding from current reality is difficult, as “big tech” paints a picture of the transformative nature of the metaverse and how it will positively impact people in their work, leisure, and social interaction. The potential impact on the way we conduct business, interact with brands and others, and develop shared experiences is likely to be transformational as the distinct lines between physical and digital are likely to be somewhat blurred from current perceptions. However, although the technology and infrastructure does not yet exist to allow the development of new immersive virtual worlds at scale - one that our avatars could transcend across platforms, researchers are increasingly examining the transformative impact of the metaverse. Impacted sectors include marketing, education, healthcare as well as societal effects relating to social interaction factors from widespread adoption, and issues relating to trust, privacy, bias, disinformation, application of law as well as psychological aspects linked to addiction and impact on vulnerable people. This study examines these topics in detail by combining the informed narrative and multi-perspective approach from experts with varied disciplinary backgrounds on many aspects of the metaverse and its transformational impact. The paper concludes by proposing a future research agenda that is valuable for researchers, professionals and policy makers alike
