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Ultra endurance

X D Wang, R T Qu, S J Wu, Q Q Duan, Z Q Liu, Z W Zhu, H F Zhang, Z F Zhang
Studying the effect of notch on the fatigue behavior of structural materials is of significance for the reliability and safety designing of engineering structural components. In this work, we conducted notch fatigue experiments of two high-strength materials, i.e. a Ti32.8Zr30.2Ni5.3Cu9Be22.7 metallic glass (MG) and a 00Ni18Co15Mo8Ti ultra-high strength steel (CM400 UHSS), and compared their notch fatigue behavior. Experimental results showed that although both the strength and plasticity of the MG were much lower than those of the UHSS, the fatigue endurance limit of the notched MG approached to that of the notched UHSS, and the fatigue ratio of the notched MG was even higher...
October 18, 2016: Scientific Reports
Da-Chuan Cheng, Jhu-Fong Wu, Yi-Hsuan Kao, Chun-Hung Su, Shing-Hong Liu
In clinics an accurate vessel segmentation method is important to quantize the vessel volume change with respect to time for artery elasticity measurement. This study proposes a modified version on 3D-expanded dynamic programming to find an optimal surface in a 3D matrix. The aim of this study is to discover the robustness against noises in measuring the cross-sectional area of the femoral artery on MRI datasets of ultra-endurance runners as accurately as possible. To do this, we use phantom images with different added noises and different image contrasts to find out the optimal parameters using grid search...
December 2016: Journal of Medical Systems
Beat Knechtle, Pantelis T Nikolaidis
BACKGROUND: To date, little is known for pacing in ultra-endurance athletes competing in a non-stop event and in a multi-stage event, and especially, about pacing in a multi-stage event with different disciplines during the stages. Therefore, the aim of the present study was to examine the effect of age, sex and calendar year on triathlon performance and variation of performance by events (i.e., swimming, cycling 1, cycling 2 and running) in 'Ultraman Hawaii' held between 1983 and 2015...
2016: PeerJ
Martin D Hoffman
Participation in ultraendurance sports has been increasing in recent years. This participation growth has been associated with an increase in research focused on such events. While the total amount of research related to these sports remains relatively small compared with other sports, the research growth is encouraging. New sources for research funding for ultraendurance sports should advance the science. In addition to continued opportunities with observational studies, promising areas of investigation remain for experimental studies and research that uses ultraendurance-sport environments as models for studies relevant to wider populations...
September 2016: International Journal of Sports Physiology and Performance
Camila L de Camargo, Letícia S Shiroma, Gabriela F Giordano, Angelo L Gobbi, Luis C S Vieira, Renato S Lima
This paper addresses an important breakthrough in the deployment of ultra-high adhesion strength microfluidic technologies to provide turbulence at harsh flow rate conditions. This paper is only, to our knowledge, the second reporting on the generation of high flow rate-assisted turbulence in microchannels. This flow solves a crucial bottleneck in microfluidics: the generation of high throughput homogeneous mixings. We focused on the fabrication of bulky polydimethylsiloxane (PDMS) microchips (without any interfaces) rather than the laborious surface modifications that were employed in the first reporting about turbulence-assisted microfluidics...
October 12, 2016: Analytica Chimica Acta
(no author information available yet)
No abstract text is available yet for this article.
August 2016: International Journal of Sports Physiology and Performance
Pierre Andonian, Magalie Viallon, Caroline Le Goff, Charles de Bourguignon, Charline Tourel, Jérome Morel, Guido Giardini, Laurent Gergelé, Grégoire P Millet, Pierre Croisille
In sports medicine, there is increasing interest in quantifying the elastic properties of skeletal muscle, especially during extreme muscular stimulation, to improve our understanding of the impact of alterations in skeletal muscle stiffness on resulting pain or injuries, as well as the mechanisms underlying the relationships between these parameters. Our main objective was to determine whether real-time shear-wave elastography (SWE) can monitor changes in quadriceps muscle elasticity during an extreme mountain ultra-marathon, a powerful mechanical stress model...
2016: PloS One
Isabel Gomila, Victoria López-Corominas, Manuela Pellegrini, Loreto Quesada, Elena Miravet, Simona Pichini, Bernardino Barceló
Munchausen syndrome by proxy (MSBP), also known as fabricated or induced illness in a child by a caretaker, is a form of abuse where a caregiver deliberately produces or feigns illness in a person under his or her care, so that the proxy will receive medical care that gratifies the caregiver. The affected children are often hospitalized for long periods and endure repetitive, painful and expensive diagnostic attempts. We present an analytically confirmed case of MSBP by alimemazine. A 3-year-old boy was brought repetitively to a Pediatric Emergency Department by his mother because he presented limb tremors, dysarthria, obnubilation, and ataxia and generalized tonic-clonic seizures coinciding with intermittent fever...
September 2016: Forensic Science International
Kerri McGreal, Pooja Budhiraja, Nishank Jain, Alan S L Yu
BACKGROUND: Hyponatremia is a common electrolyte imbalance that clinicians face on a regular basis. SUMMARY: This review aims to discuss four current challenges that can arise when diagnosing and treating hyponatremia: low solute intake, heart failure, exercise-associated hyponatremia, and mild chronic hyponatremia. Low solute intake in a person who already has a urinary concentrating defect will lead to increased retention of free water. The free water retention will cause or worsen hyponatremia that is already present...
June 2016: Kidney Diseases
Domingo Jesús Ramos-Campo, Vicente Ávila-Gandía, Fernando Alacid, Fulgencio Soto-Méndez, Pedro E Alcaraz, Francisco Javier López-Román, Jacobo Ángel Rubio-Arias
The biological response to ultra-endurance mountain race events is not yet well understood. The aim of this study was to determine the biochemical and physiological changes after performing an ultra-endurance mountain race in runners. We recruited 11 amateur runners (age: 29.7 ± 10.2 years; height: 179.7 ± 5.4 cm; body mass: 76.7 ± 10.3 kg). Muscle damage, lactate concentration, energy balance, rating of perceived exertion (RPE), heart rate (HR), heart rate variability (HRV), body composition changes, and jump performance were analyzed before, during (only lactate, HR, and HRV), and after the race...
August 2016: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Rachel Lord, Keith George, John Somauroo, Mike Stembridge, Nikhil Jain, Martin D Hoffman, Rob Shave, Francois Haddad, Euan Ashley, Helen Jones, David Oxborough
BACKGROUND: The aim of this study was to use novel area-deformation (ε) loops to interrogate the interaction between the right ventricular (RV) and left ventricular (LV) mechanics following a 100-mile endurance run. METHODS: Fifteen participants (mean body mass, 70.1 ± 8.8 kg; mean age, 40 ± 8 years) were recruited for the study. Echocardiography was performed before the race, after the race, and 6 hours into recovery. RV and LV area and longitudinal ε were assessed using standard and speckle-tracking echocardiography...
September 2016: Journal of the American Society of Echocardiography
Brian Kupchak, Elizabeth Umeda, Josh Kazman, Jakob Vingren, Elaine Lee, Lawrence Armstrong, Patricia Deuster
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Catherine Saenz, Daniel J Freidenreich, Laura J Kunces, Jenna M Bartley, Brent C Creighton, Giselle A Aerni, Jeffrey M Anderson, Patrick M Davitt, Colleen X Munoz, Elaine C Lee, Stephen O Opiyo, Carl M Maresh, William J Kraemer, Jeff S Volek
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Justin D Roberts, Craig A Suckling, Georgia Y Peedle, Dan A Gordon, Hannah Marshall, Lee Taylor, Michael G Roberts
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Karen M Gonçalves, Ivaldo I Junior, Vassiliki Papadimitriou, Maria Zoumpanioti, Ivana C R Leal, Rodrigo O M A de Souza, Yraima Cordeiro, Aristotelis Xenakis
Two commercially available and widely used enzymes, the parent Thermomyces lanuginosus lipase (TLL) and the shuffled phospholipase A1 Lecitase (Lecitase Ultra), were encapsulated in AOT/isooctane reverse micelles and evaluated regarding their structure and activity. Preparations were also tested as effective biocatalysts. Small-angle X-ray scattering (SAXS), electronic paramagnetic resonance (EPR), and fluorescence spectroscopy were the techniques applied to assess the effects of enzyme incorporation to a reverse micellar nanostructure...
July 5, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Daniela Chlíbková, Thomas Rosemann, Lenka Posch, Radek Matoušek, Beat Knechtle
The monitoring of body mass (BM), plasma sodium concentration ([Na⁺]) and urinary specific gravity (Usg) are commonly used to help detect and prevent over- or dehydration in endurance athletes. We investigated pre-and post-race hydration status in 113 amateur 24-h ultra-runners, 100-km ultra-runners, multi-stage mountain bikers and 24-h mountain bikers, which drank ad libitum without any intervention and compared results of hyponatremic and non-hyponatremic finishers. On average, pre-race plasma [Na⁺] and both pre- and post-race levels of Usg and BM were not significantly different between both groups...
June 30, 2016: Chinese Journal of Physiology
Samuel J E Lucas, Jørn W Helge, Uwe H W Schütz, Ralph F Goldman, James D Cotter
This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may be at least as problematic, and are therefore included as a reference, e...
2016: Extreme Physiology & Medicine
Lejla Salihu, Christoph Alexander Rüst, Thomas Rosemann, Beat Knechtle
Recent studies reported that the sex difference in performance in ultra-endurance sports such as swimming and cycling changed over the years. However, the aspect of drafting in draft-legal ultra-endurance races has not yet been investigated. This study investigates the sex difference in ultra-swimming and ultra-cycling draft-legal races where drafting - swimming or cycling behind other participants to save energy and have more power at the end of the race to overtake them, is allowed. The change in performance of the annual best and the annual three best in an ultra-endurance swimming race (16-km 'Faros Swim Marathon') over 38 years and in a 24-h ultra-cycling race ('World Cycling Race') over 13 years were compared and analysed with respect to sex difference...
April 30, 2016: Chinese Journal of Physiology
Rachel Lord, Keith George, John Somauroo, Nikhil Jain, Kristin Reese, Martin D Hoffman, Francois Haddad, Euan Ashley, Helen Jones, David Oxborough
BACKGROUND: Prolonged strenuous exercise has a profound effect on cardiac function. The right heart may be more susceptible to this imposition; yet, right-sided chest leads have not been utilised in this setting. METHODS: Thirty highly trained athletes at the 2014 Western States 100-mile Endurance Run from Squaw Valley to Auburn, California (body mass 68 ± 12 kg, age 45 ± 10 years, 57 ± 15 miles per week) were recruited for the study. Pre- and post-race, a right-sided 12-lead ECG was obtained and data were extracted for P, R and S waves, J point, ST segment and T wave amplitude...
November 2016: European Journal of Sport Science
K Krzemiński, M Buraczewska, Z Miśkiewicz, J Dąbrowski, M Steczkowska, A Kozacz, A Ziemba
The purpose of this study was to investigate the effect of ultra-endurance exercise on left ventricular (LV) performance and plasma concentration of interleukin (IL)-6, IL-10, IL-18 and tumour necrosis factor alpha (TNF-α) as well as to examine the relationships between exercise-induced changes in plasma cytokines and those in echocardiographic indices of LV function in ultra-marathon runners. Nine healthy trained men (mean age 30±1.0 years) participated in a 100-km ultra-marathon. Heart rate, blood pressure, ejection fraction (EF), fractional shortening (FS), ratio of early (E) to late (A) mitral inflow peak velocities (E/A), ratio of early (E') to late (A') diastolic mitral annulus peak velocities (E'/A') and E-wave deceleration time (DT) were obtained by echocardiography before, immediately after and in the 90th minute of the recovery period...
March 2016: Biology of Sport
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