Importance: U.S. Army Basic Combat Training (BCT) improves tibial volumetric bone mineral density (BMD) and structure in most, but not all soldiers.
View Article and Find Full Text PDFMcFadden, BA, Walker, AJ, Cintineo, HP, Bozzini, BN, Sanders, DJ, Chandler, AJ, and Arent, SM. Sex differences in physiological responses to a National Collegiate Athletic Association Division I soccer season. J Strength Cond Res 38(11): 1891-1899, 2024-Identifying physiological changes that occur in response to workload demands can help to elucidate athlete management and recovery strategies.
View Article and Find Full Text PDFObjective: Less than half of servicewomen report loss of menses during initial military training. However, self-reported menstrual status may not accurately reflect hypothalamic-pituitary-ovarian (HPO) axis suppression and may underestimate reproductive health consequences of military training. Our aim was to characterise HPO axis function during US Army Basic Combat Training (BCT) in non-hormonal contraceptive-using women and explore potential contributors to HPO axis suppression.
View Article and Find Full Text PDFIn view of developing photoelectrosynthetic cells which are able to store solar energy in chemical bonds, water splitting is usually the reaction of choice when targeting hydrogen production. However, alternative approaches can be considered, aimed at substituting the anodic reaction of water oxidation with more commercially capitalizable oxidations. Among them, the production of bromine from bromide ions was investigated long back in the 1980s by Texas Instruments.
View Article and Find Full Text PDFAmong post-lithium ion battery technologies, rechargeable chemistries with Zn anodes bear notable technological promise owing to their high theoretical energy density, lower manufacturing cost, availability of raw materials and inherent safety. However, Zn anodes, when employed in aqueous electrolytes, suffer from hydrogen evolution, passivation, and shape changes. Alternative electrolytes can help tackle these issues, preserving the green and safe characteristics of aqueous-based ones.
View Article and Find Full Text PDFMcFadden, BA, Bozzini, BN, Cintineo, HP, Hills, SP, Walker, AJ, Chandler, AJ, Sanders, DJ, Russell, M, and Arent, SM. Power, endurance, and body composition changes over a collegiate career in National Collegiate Athletic Association Division I women soccer athletes. J Strength Cond Res 37(7): 1428-1433, 2023-The purpose of this study was to determine longitudinal changes in fitness and body composition throughout athletes' 4-year collegiate soccer careers.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
March 2021
CuWO is a ternary metal oxide semiconductor with promising properties for photoelectrochemical (PEC) water splitting and solar light conversion, due to its quite low band gap (2.3 eV) and high stability in an alkaline environment. Aiming at understanding the origin of the relatively low PEC efficiency attained with CuWO photoanodes, we here investigate transparent CuWO electrodes prepared by a simple solution-based method through the combination of femtosecond transient absorption spectroscopy with electrochemical, PEC, and photochromic characterizations.
View Article and Find Full Text PDFMcFadden, BA, Walker, AJ, Bozzini, BN, Hofacker, M, Russell, M, and Arent, SM. Psychological and physiological changes in response to the cumulative demands of a women's division I collegiate soccer season. J Strength Cond Res 36(5): 1373-1382, 2022-This study sought to determine the effects of a women's collegiate soccer season on psychological markers, biomarkers, sleep, and performance.
View Article and Find Full Text PDFHigh training demands throughout the competitive season in female collegiate soccer players have been shown to induce changes in biomarkers indicative of stress, inflammation, and reproduction, which may be exacerbated in athletes using oral contraceptives (OCs). This study aimed to compare biomarkers and body composition between OC-using and nonusing (CON) female soccer players throughout a competitive season. Female collegiate soccer players were stratified into two groups based on their reported OC use at the start of preseason (OC: = 6; CON: = 17).
View Article and Find Full Text PDFBozzini, BN, McFadden, BA, Scruggs, SK, and Arent, SM. Evaluation of performance characteristics and internal and external training loads in female collegiate beach volleyball players. J Strength Cond Res 35(6): 1559-1567, 2021-Although women's beach volleyball is the fastest growing collegiate sport, the training demands and performance characteristics have yet to be determined.
View Article and Find Full Text PDFThe purpose of this study was to evaluate the effects of a competitive soccer season on biomarkers and performance metrics in order to determine the correlation between changes in biomarkers, body composition, and performance outcomes. Twenty-one Division 1 female collegiate soccer players were monitored throughout the 16-week season. Player workload was measured using heart rate and Global Position Satellite systems at all practices and games.
View Article and Find Full Text PDFBozzini, BN, McFadden, BA, Walker, AJ, and Arent, SM. Varying demands and quality of play between in-conference and out-of-conference games in Division I collegiate women's soccer. J Strength Cond Res 34(12): 3364-3368, 2020-The purpose of this study was to assess differences in physical workloads, physiological responses, and performance variables between in-conference (IC) and out-of-conference (OC) games during a collegiate women's soccer season.
View Article and Find Full Text PDFBackground: This study evaluated the feasibility of a technology-enhanced group-based fitness intervention for adolescent and young adult (AYA) survivors of childhood cancer.
Procedure: AYA survivors ages 13-25 years were randomized to the intervention (eight in-person group sessions with mobile app and FitBit followed by 4 weeks of app and FitBit only) or waitlist control. Assessments were at 0, 2, 3, 6, and 9 months.
Walker, AJ, McFadden, BA, Sanders, DJ, Bozzini, BN, Conway, SP, and Arent, SM. Early season hormonal and biochemical changes in Division I field hockey players: is fitness protective? J Strength Cond Res 34(4): 975-981, 2020-The purpose was to evaluate changes in hormonal and biochemical markers as a result of the accumulated stress of the initial 4-week training block in field hockey players. Women's Division I field hockey players (N = 22; Mage = 19.
View Article and Find Full Text PDFMcFadden, BA, Walker, AJ, Bozzini, BN, Sanders, DJ, and Arent, SM. Comparison of internal and external training loads in male and female collegiate soccer players during practices vs. games.
View Article and Find Full Text PDFUnderstanding the lateral variations in the elemental and chemical state of constituents induced by electrochemical reactions at nanoscales is crucial for the advancement of electrochemical materials science. This requires in situ studies to provide observables that contribute to both modeling beyond the phenomenological level and exactly transducing the functionally relevant quantities. A range of X-ray coherent diffraction imaging (CDI) approaches have recently been proposed for imaging beyond the diffraction limit with potentially dramatic improvements in time resolution with chemical sensitivity.
View Article and Find Full Text PDFThis paper reports on the quantitative assessment of the oxygen reduction reaction (ORR) electrocatalytic activity of electrodeposited Mn/polypyrrole (PPy) nanocomposites for alkaline aqueous solutions, based on the Rotating Disk Electrode (RDE) method and accompanied by structural characterizations relevant to the establishment of structure-function relationships. The characterization of Mn/PPy films is addressed to the following: (i) morphology, as assessed by Field-Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscope (AFM); (ii) local electrical conductivity, as measured by Scanning Probe Microscopy (SPM); and (iii) molecular structure, accessed by Raman Spectroscopy; these data provide the background against which the electrocatalytic activity can be rationalised. For comparison, the properties of Mn/PPy are gauged against those of graphite, PPy, and polycrystalline-Pt (poly-Pt).
View Article and Find Full Text PDFThis paper reports an investigation into the aging of pyrolyzed cobalt/polypyrrole (Co/PPy) oxygen reduction reaction (ORR) electrocatalysts, based on quasi-in-situ photoelectron microspectroscopy. The catalyst precursor was prepared by potentiostatic reverse-pulse coelectrodeposition from an acetonitrile solution on graphite. Accelerated aging was obtained by quasi-in-situ voltammetric cycling in an acidic electrolyte.
View Article and Find Full Text PDFElectrodeposition of graphene-supported Co for ORR electrocatalysts from an acetonitrile solution has been studied by a multi-technique approach, combining a suite of spectroscopic methods with electrochemical measurements, allowing a molecular-level understanding of potentiostatic and pulsed-potential plating processes from the organic solvent onto a freestanding graphene film. The formation of the graphene film by the light-scribe approach has been monitored by Raman spectroscopy; the electrodeposition process has been clarified by cyclic voltammetry and the compositional and chemical-state distribution of Co have been investigated ex situ by soft X-ray absorption spectroscopy and fluorescence mapping, showing that both spatial distribution and valence state are homogeneous and independent of the local current density. The deposit consists in micrometric aggregates of Co/CoO nanoparticles with diameter ca.
View Article and Find Full Text PDFIn this paper we describe the one-pot fabrication of hydroxyapatite (HA)-heparin composites by electrodeposition onto Ti substrates and their characterisation in terms of structure, morphology, heparin content and bioactivity. HA coatings are well known and widely applied osteointegration enhancers, but post-implant healing rate in dental applications is still suboptimal: e.g.
View Article and Find Full Text PDFIn this paper we report on the fabrication and testing of a novel concept of sealed electrochemical microcell for in situ soft X-ray microspectroscopy in transmission, dedicated for nonvacuum compatible electrolytes. The microcell, fabricated using ultraviolet lithography, at variance with previous versions of electrochemical wet cells, that featured an optical window glued on top of the electrode system and a very limited electrolyte volume, the device presented here is a single solid block based around a microfabricated channel with fixed optical windows and apt for microfluidic work. Moreover, this cell allows to employ an advanced electrodic geometry developed in our group - so far used only in open electrochemical cells for work with vacuum-compatible electrolytes - also with low-vapor pressure liquids, possibly saturated with the required gases.
View Article and Find Full Text PDFThe challenges in development of solid oxide fuel cells (SOFCs) are reducing their dimensions and increasing their efficiency and durability, which requires physicochemical characterization at micro-scales of the device components during operation conditions. Recently, the unique potential of scanning photoelectron microscopy (SPEM) has been demonstrated by in-situ studies of externally-driven SOFCs, which mimic real devices. Here we overcome the gap between model and real systems using a single-chamber Ni|YSZ|Mn SOFC, supporting a range of self-driven electrochemical reactions in variable gas environments and temperatures.
View Article and Find Full Text PDFFuel cells are one of the most appealing environmentally friendly devices for the effective conversion of chemical energy into electricity and heat, but still there are key barriers to their broad commercialization. In addition to efficiency, a major challenge of fuel-cell technology is the durability of the key components (interconnects, electrodes, and electrolytes) that can be subject to corrosion or undesired morphology and chemical changes occurring under operating conditions. The complementary capabilities of synchrotron-based soft X-ray microscopes in terms of imaging, spectroscopy, spatial and time resolution, and variable probing depths are opening unique opportunities to shed light on the multiple processes occurring in these complex systems at microscopic length scales.
View Article and Find Full Text PDFIn this paper we report an in situ electrochemical Sum-/Difference Frequency Generation (SFG/DFG) spectroscopy investigation of the adsorption of nitrile and CN⁻ from the ionic liquid 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl) amide ([BMP][TFSA]) containing 4-{2-[1-(2-cyanoethyl)-1,2,3,4-tetrahydroquinolin-6-yl]-diazenyl}benzonitrile (CTDB) at Au electrodes in the absence and in the presence of the Au-electrodeposition process from K[Au(CN)₂]. The adsorption of nitrile and its coadsorption with CN⁻ resulting either from the cathodic decomposition of the dye or from ligand release from the Au(I) cyanocomplex yield potential-dependent single or double SFG bands in the range 2,125-2,140 cm⁻¹, exhibiting Stark tuning values of ca. 3 and 1 cm⁻¹ V⁻¹ in the absence and presence of electrodeposition, respectively.
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