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Oxygen uptake

Matthew R Noerpel, Sang Soo Lee, John J Lenhart
Predicting the environmental fate of lead relies on a detailed understanding of its coordination to mineral surfaces, which in turn reflects the innate reactivity of the mineral surface. In this research, we investigated fundamental dependencies in lead adsorption to hematite by coupling extended X-ray absorption fine structure (EXAFS) spectroscopy on hematite particles (10 and 50 nm) with resonant anomalous X-ray reflectivity (RAXR) to single crystals expressing the (001), (012), or (110) crystallographic face...
October 21, 2016: Environmental Science & Technology
H Cumming, N A Herbert
Turbidity as a result of increased suspended sediments in coastal waters is an environmental stress of worldwide concern. Recent research on fish suggests that detrimental changes to gill structure can occur in turbid waters, with speculation that these alterations diminish fitness variables, such as growth and development, by negatively impacting the O2 uptake capacity (respiration) of fish. Specifically to address this unknown, the impact of turbid water on the gill structure, somatic growth rate and O2 uptake rates of a juvenile sparid species (Pagrus auratus) was addressed following exposure to five different turbidity treatments (<10, 20, 40, 60 or 80 nephelometric turbidity units) for 30 days...
2016: Conservation Physiology
Victor M Niemeijer, Ruud F Spee, Thijs Schoots, Pieter F F Wijn, Hareld M Kemps
The extent and speed of transient skeletal muscle deoxygenation during exercise onset in chronic heart failure (CHF) patients is related to impairments of local O2 delivery and utilization. This study examined the physiological background of submaximal exercise performance in 19 moderately impaired CHF patients (Weber class A, B, and C) compared with 19 matched healthy control (HC) subjects by measuring skeletal muscle oxygenation (SmO2) changes during cycling exercise. All subjects performed two subsequent moderate-intensity 6-minute exercise tests (bout 1 and 2) with measurements of pulmonary oxygen uptake kinetics, and SmO2 using near infrared (NIR) spatially resolved spectroscopy (SRS) at the vastus lateralis for determination of absolute oxygenation values, amplitudes, kinetics (mean response time for onset), and deoxygenation overshoot characteristics...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Wojciech Kosmala, Aleksandra Rojek, Monika Przewlocka-Kosmala, Leah Wright, Andrzej Mysiak, Thomas H Marwick
BACKGROUND: Impaired functional capacity is a hallmark of patients with heart failure with preserved ejection fraction (HFpEF). Despite the association of HFpEF with reduced myocardial compliance attributed to fibrosis, spironolactone has not been shown to alter outcomes-perhaps reflecting the heterogeneity of underlying pathological mechanisms. OBJECTIVES: The authors sought to identify improvement in exercise capacity with spironolactone in the subset of patients with HFpEF with exercise-induced increase in ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') reflecting elevation of left ventricular (LV) filling pressure...
October 25, 2016: Journal of the American College of Cardiology
Liang Chen, Jian Kuang, Jian-Hao Pei, Hong-Mei Chen, Zhong Chen, Zhong-Wen Li, Hua-Zhang Yang, Xiao-Ying Fu, Long Wang, Zhi-Jiang Chen, Shui-Qing Lai, Shu-Ting Zhang
BACKGROUND: The aim of this study was to explore factors affecting cardiorespiratory fitness in males and females with different body mass index. METHODS: The National Health and Nutrition Examination Survey 1999-2004 data were used for this retrospective study. Estimated maximal oxygen uptake (VO2max) is surrogate for cardiorespiratory fitness (CRF). Univariate and multivariate linear regression analyses were performed to explore whether study variables were associated with estimated VO2max stratified by gender and BMI categories...
October 21, 2016: Annals of Medicine
Yuan-Bo Wu, Li Zhang, Wen-Ting Li, Yi Yang, Jiang-Ming Zhao
BACKGROUND: Artesunate (ART) is an antimalarial drug with potential anti-inflammatory effect. This study aimed to explore the potential protective role of ART in hepatic encephalopathy (HE), involving its function against ammonia toxicity. METHODS: HE rats were induced by the administration of thioacetamide (TAA, 300mg/kg/day). Spatial learning ability was tested in both Morris water and eight-arm radial maze. Rat cerebellar granule neurons (CGNs) were prepared for ammonia treatment in vitro, in line with SH-SY5Y and C6 cells...
October 17, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
K Bilmin, T Kujawska, W Secomski, A Nowicki, P Grieb
Sonodynamic therapy (SDT) is a promising technique based on the ability of certain substances, called sonosensitizers, to sensitize cancer cells to non-thermal effects of low-energy ultrasound waves, allowing their destruction. Sonosensitization is thought to induce cell death by direct physical effects such as cavitation and acoustical streaming as well as by complementary chemical reactions generating oxygen free radicals. One of the promising sonosensitizers is 5-aminolevulinic acid (ALA) which upon selective uptake by cancer cells is metabolized and accumulated as protoporphyrin IX...
2016: Folia Neuropathologica
Kevin Forton, Yoshiki Motoji, Gael Deboeck, Vitalie Faoro, Robert Naeije
There has been revival of in interest in exercise testing of the pulmonary circulation for the diagnosis of pulmonary vascular disease, but there still is uncertainty about body position and the most relevant measurements. Doppler echocardiography pulmonary hemodynamic measurements were performed at progressively increased workload in 26 healthy adult volunteers in supine, semi-recumbent and upright positions which were randomly assigned at 24 hours intervals. Mean pulmonary artery pressure (mPAP) was estimated from the maximum tricuspid regurgitation jet velocity...
October 7, 2016: Journal of Applied Physiology
Nastasia Marinus, Liene Bervoets, Guy Massa, Kenneth Verboven, An Stevens, Tim Takken, Dominique Hansen
BACKGROUND: Cardiopulmonary exercise testing is advised ahead of exercise intervention in obese adolescents to assess medical safety of exercise and physical fitness. Optimal validity and reliability of test results are required to identify maximal exercise effort. As fat oxidation during exercise is disturbed in obese individuals, it remains an unresolved methodological issue whether the respiratory gas exchange ratio (RER) is a valid marker for maximal effort during exercise testing in this population...
October 20, 2016: Journal of Sports Medicine and Physical Fitness
Salem A E Omar, Paul A Scattergood, Luke K McKenzie, Helen E Bryant, Julia A Weinstein, Paul I P Elliott
The complex [Os(btzpy)₂][PF₆]₂ (1, btzpy = 2,6-bis(1-phenyl-1,2,3-triazol-4-yl)pyridine) has been prepared and characterised. Complex 1 exhibits phosphorescence (λem = 595 nm, τ = 937 ns, φem = 9.3% in degassed acetonitrile) in contrast to its known ruthenium(II) analogue, which is non-emissive at room temperature. The complex undergoes significant oxygen-dependent quenching of emission with a 43-fold reduction in luminescence intensity between degassed and aerated acetonitrile solutions, indicating its potential to act as a singlet oxygen sensitiser...
October 18, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Julienne K Muenzner, Bernhard Biersack, Alexander Albrecht, Tobias Rehm, Ulrike Lacher, Wolfgang Milius, Angela Casini, Jing-Jing Zhang, Ingo Ott, Viktor Brabec, Olga Stuchlikova, Ion C Andronache, Detlef Schuppan, Leonard Kaps, Rainer Schobert
Four gold(I) carbene complexes featuring 4-ferrocenyl substituted imidazol-2-ylidene ligands were investigated for antiproliferative and antivascular properties. They were active against a panel of seven cancer cell lines, including multidrug-resistant ones, with low micromolar or nanomolar IC50 (72 h) values, according to their lipophilicity and cellular uptake. The delocalised lipophilic cationic complexes 8 and 10 acted by increasing the reactive oxygen species in two ways: via a genuine ferrocene effect and by inhibiting the thioredoxin reductase...
October 20, 2016: Chemistry: a European Journal
Rafael Mesquita, Frits M E Franssen, Sarah Houben-Wilke, Nicole H M K Uszko-Lencer, Lowie E G W Vanfleteren, Yvonne M J Goërtz, Fabio Pitta, Emiel F M Wouters, Martijn A Spruit
BACKGROUND: It remains unknown whether and to what extent impaired left ventricular ejection fraction (LVEF) affects physical and psychological status in COPD. We aimed to compare health outcome measures between COPD patients with and without impaired LVEF after adjusting for age, sex, BMI and FEV1. METHODS: Impaired LVEF was defined as values <50%. 85 COPD patients with impaired LVEF and 85 COPD patients with normal LVEF were matched for sex, age, BMI and FEV1...
October 11, 2016: International Journal of Cardiology
Ryota Kobayashi, Yuto Hashimoto, Hiroyuki Hatakeyama, Takanobu Okamoto
Arterial stiffness increases after glucose ingestion. Acute low- and moderate-intensity aerobic exercise decreases arterial stiffness. However, the acute effects of 30 min of cycling at low- and moderate-intensity [25% (LE trial) and 65% (ME trial) peak oxygen uptake, respectively] on arterial stiffness at 30, 60 and 120 min of a postexercise glucose ingestion. Ten healthy young men (age, 22·4 ± 0·5 years) performed LE and ME trials on separate days in a randomized controlled crossover fashion. Carotid-femoral (aortic) pulse wave velocity (PWV), femoral-ankle (leg) PWV, carotid augmentation index (AIx) and carotid blood pressure (BP) (applanation tonometry), brachial and ankle BP (oscillometric device), heart rate (HR) (electrocardiography), blood glucose (UV-hexokinase method) and blood insulin (CLEIA method) levels were measured at before (baseline) and at 30, 60 and 120 min after the 75-g OGTT...
October 18, 2016: Clinical Physiology and Functional Imaging
Cory W Baumann, Dongmin Kwak
PURPOSE: Echinacea is an herbal supplement used by endurance athletes for its performance boosting properties. It is thought that Echinacea improves the blood's oxygen carrying capacity by increasing production of erythropoietin (EPO), a glycoprotein that regulates red blood cell formation. Subsequently, these changes would lead to an overall improvement in maximal oxygen uptake (VO2max) and running economy (RE), two markers of aerobic fitness. The purpose of this review is to briefly discuss the physiological variables associated with distance running performance and how these variables are influenced by Echinacea supplementation...
September 2016: Journal of Exercise Nutrition & Biochemistry
Pedro M D Agrícola, Daniel G da Silva Machado, Luiz F de Farias Junior, Luiz I do Nascimento Neto, André I Fonteles, Samara K A da Silva, Cheng H N Chao, Eduardo B Fontes, Hassan M Elsangedy, Alexandre H Okano
Pleasure plays a key role in exercise behavior. However, the influence of cycling cadence needs to be elucidated. Here, we verified the effects of cycling cadence on affect, perceived exertion (ratings of perceived exertion), and physiological responses. In three sessions, 15 men performed a maximal cycling incremental test followed by two 30-min constant workload (50% of peak power) bouts at 60 and 100 r/min. The pleasure was higher when participants cycled at 60 r/min, whereas ratings of perceived exertion, heart rate, and oxygen uptake were lower (p < ...
October 17, 2016: Perceptual and Motor Skills
Agathe Gerwina Elena Pollmann, Marianne Frederiksen, Eva Prescott
PURPOSE: Evidence of the effect of cardiac rehabilitation (CR) after heart valve surgery is scarce, but nevertheless CR is recommended for this group of patients. Therefore, this study assessed the effect of CR on exercise capacity, cardiovascular risk factors, and long-term mortality and morbidity, as well as predictors for enrolment in or failing to complete CR. METHODS: A review of medical records identified 250 patients who underwent heart valve surgery between January 2009 and August 2013...
October 14, 2016: Journal of Cardiopulmonary Rehabilitation and Prevention
Veronika Huntosova, Katarina Stroffekova
Photosensitizers (PSs) in photodynamic therapy (PDT) are, in most cases, administered systemically with preferential accumulation in malignant tissues; however, exposure of non-malignant tissues to PS may also be clinically relevant, when PS molecules affect the pro-apoptotic cascade without illumination. Hypericin (Hyp) as PS and its derivatives have long been studied, regarding their photodynamic and photocytotoxic characteristics. Hyp and its derivatives have displayed light-activated antiproliferative and cytotoxic effects in many tumor cell lines without cytotoxicity in the dark...
October 14, 2016: Cancers
Yuanting Cui, Li Li, Peng Gao, Liqun Ma, Daoyan Liu, Zhiming Zhu
OBJECTIVE: Obesity is global healthy problem. Uncoupling protein 1 (UCP1) mainly expresses on brown adipose tissue (BAT), uncouples energy substrate oxidation from mitochondrial ATP production and results in the loss of potential energy as heat. Transient receptor potential vanilloid subfamily, member 1 (TRPV1) is the heat-gated cation ion channel. The aim of this study was to investigate the in vivo role of TRPV1 and UCP1 co-action in obesity. DESIGN AND METHOD: We generated and characterized UCP1 mice lacking TRPV1 activity (TRPV1/UCP1 mice)...
September 2016: Journal of Hypertension
Brandi Wynne, Trinity Kronk, Otor Al-Khalili, Benjamin Ko, Franziska Theilig, Douglas Eaton, Robert Hoover
OBJECTIVE: Hypertension is characterized by increased sodium reabsorption along the aldosterone-sensitive distal nephron (ASDN) and systemic inflammation. Interleukin-6 (IL-6) is a possible mediator, signaling via the transmembrane IL-6 receptor alpha (IL-6Rα); however, whether IL-6Rα is present in the distal convoluted tubule (DCT) is unknown. Increased sodium reabsorption is not always correlated with increased aldosterone (Aldo). Thus, understanding how Aldo-independent sodium reabsorption occurs is critical...
September 2016: Journal of Hypertension
Sae Young Jae, Sudhir Kurl, Barry A Franklin, Jari A Laukkanen
OBJECTIVES: We investigated whether long-term changes in cardiorespiratory fitness (CRF) predict the risk of incident hypertension, independent of risk factors, in initially normotensive men. METHODS: This prospective study from the Kuopio Ischemic Heart Disease Study included 431 male participants without hypertension who underwent symptom-limited maximal cardiopulmonary exercise testing at baseline and during a second examination, 11-years later, who were re-evaluated for hypertension at 20-year follow-up...
October 18, 2016: American Journal of Human Biology: the Official Journal of the Human Biology Council
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