Biomarkers of inflammation, muscle damage, and oxidative stress after high-intensity exercise have been described previously; however, further understanding of their role in the postexercise recovery ...period is necessary. Because these markers have been implicated in cell signaling, they may be specifically related to the training adaptations induced by high-intensity exercise. Thus, a clear model showing their responses to exercise may be useful in characterizing the relative recovery status of an athlete. The purpose of this study was twofold: (a) to investigate the time course of markers of muscle damage and inflammation in the blood from 3 to 72 hours after combined training exercises and (b) to investigate indicators of oxidative stress and damage associated with increased reactive oxygen species production during high-intensity exercise in elite athletes. Nineteen male athletes performed a combination of high-intensity aerobic and anaerobic training exercises. Samples were acquired immediately before and at 3, 6, 12, 24, 48, and 72 hours after exercise. The appearance and clearance of creatine kinase and lactate dehydrogenase in the blood occurred faster than previous studies have reported. The neutrophil/lymphocyte ratio summarizes the mobilization of 2 leukocyte subpopulations in a single marker and may be used to predict the end of the postexercise recovery period. Further analysis of the immune response using serum cytokines indicated that high-intensity exercise performed by highly trained athletes only generated inflammation that was localized to the skeletal muscle. Biomarkers are not a replacement for performance tests, but when used in conjunction, they may offer a better indication of metabolic recovery status. Therefore, the use of biomarkers can improve a coach's ability to assess the recovery period after an exercise session and to establish the intensity of subsequent training sessions.
The combination of complementary techniques in the characterization of catalysts under working conditions is a very powerful tool for an accurate and in‐depth comprehension of the system ...investigated. In particular, X‐ray absorption spectroscopy (XAS) coupled with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and mass spectroscopy (MS) is a powerful combination since XAS characterizes the main elements of the catalytic system (selecting the absorption edge) and DRIFTS monitors surface adsorbates while MS enables product identification and quantification. In the present manuscript, a new reactor cell and an experimental setup optimized to perform time‐resolved experiments on heterogeneous catalysts under working conditions are reported. A key feature of this setup is the possibility to work at high temperature and pressure, with a small cell dead volume. To demonstrate these capabilities, performance tests with and without X‐rays are performed. The effective temperature at the sample surface, the speed to purge the gas volume inside the cell and catalytic activity have been evaluated to demonstrate the reliability and usefulness of the cell. The setup capability of combining XAS, DRIFTS and MS spectroscopies is demonstrated in a time‐resolved experiment, following the reduction of NO by Rh nanoparticles supported on alumina.
A new reactor cell and experimental setup designed to perform time‐resolved experiments on heterogeneous catalysts under working conditions that simulltaneously combines XAS, DRIFT and MS spectroscopies are reported.
This study evaluated the effects of 2 different types of acute aerobic exercise on the osmotic stability of human erythrocyte membrane and on different hematological and biochemical variables that ...are associated with this membrane property. The study population consisted of 20 healthy and active men. Participants performed single sessions of 2 types of exercise. The first session consisted of 60 min of moderate-intensity continuous exercise (MICE). The second session, executed a week later, consisted of high-intensity interval exercise (HIIE) until exhaustion. The osmotic stability of the erythrocyte membrane was represented by the inverse of the salt concentration (1/H50) at the midpoint of the sigmoidal curve of dependence between the absorbance of hemoglobin and the NaCl concentration. The values of 1/H50 changed from 2.29±0.1 to 2.33±0.09 after MICE and from 2.30±0.08 to 2.23±0.12 after HIIE. During MICE mean corpuscular volume increased, probably due to in vivo lysis of older erythrocytes, with preservation of cells that were larger and more resistant to in vitro lysis. The study showed that a single bout of acute exercise affected erythrocyte stability, which increased after MICE and decreased after HIIE.
Abstract Aims: Movement specific warm-up is a widely accepted practice in the sports environment; however, little is known regarding the ideal intensity of its performance. To verify the effects of ...adding high-intensity sets to the warm-up on strength, muscular electrical activity, and body temperature in the bench press exercise. Methods: Twelve men (21±1.7 years, 23.9±3.5 kg.m2) were evaluated by a maximal repetition test (1-RM), after which the volunteers performed three procedures: Low-intensity warm-up (LIW), low-intensity warm-up with high-intensity sets (WHI), and no warm-up (CON). Next, they performed maximal isometric voluntary contractions (MIVC) of the chest press to assess the electromyographic activity of the pectoralis major, peak rate of force, development (RFDpeak), and maximum strength (Smax). The skin temperature was evaluated before starting the test. Results: No between-condition differences (p≤0.05) were found for Smax (CON = 320.3±83.8 N; LIW = 300.1±131.6 N, HIW = 327.0±113.9 N; p = 0.689), RFDpeak (CON = 4399±1776 Ns-1; LIW = 3476±1905 Ns-1; HIW = 4715±2184 Ns-1; p = 0.243), skin temperature (CON = 34.0±1.0 °C, LIW = 34.9±0.8 °C, HIW = 34.8±1.1 °C; p = 0.078) or myoelectric activity according to the root mean square index of sternocostal (p = 0.402) and clavicular (p = 0.535) heads, as well as the median frequency data of sternocostal (p = 0.169) and clavicular heads (p = 0.456). Conclusion: In conclusion, the proposed warm-up protocols were not able to modify strength, muscle electrical activity, or skin temperature in the bench press exercise.
In order to provide additional information on the behaviour of biochemical parameters related to stress responses to a specific long-term competition, we aimed to compare the stressful effects of a ...long-lasting competition on physiological variables in men and women.
This is a prospective observational analytical study. Twenty-five professional athletes, 15 men and 10 women, travelled 460 km for 4 days in an international edition of the Ecomotion/Pro AR World.
After the competition, we detected an increase in α-amylase and cortisol levels and a decrease in salivary immunoglobulin A (lgA) levels. The relative percentage changes in α-amylase, IgA and cortisol levels were significantly higher in women than in men, whereas women had lower relative percentage changes in glucose and lactate levels compared with men. There was a decrease in lymphocyte, eosinophil and monocyte counts, with relative percentage decreases in lymphocytes and monocytes being significantly higher in female athletes than in males. There were increases in the serum activities of total creatine kinase (CK), the creatine kinase myocardial isoform (CKMB), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) at the end of the test, with significantly higher elevations of total CK, CKMB and LDH in men and ALT in women.
Long-lasting competition induced stress, muscle damage, anaemia and changes in the immune system. Women had more intense responses of cortisol and leukocytes.
The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the ...light vector mediator of this dark force, the U boson, with the KLOE detector at the DAΦNE e+e− collider. Using an integrated luminosity of 1.54 fb−1, we studied the process e+e−→Uγ, with U→e+e−, using radiative return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90% CL upper limit on the mixing strength between the Standard Model photon and the dark photon, ε2, at 10−6–10−4 in the 5–520 MeV/c2 mass range.
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•CO dissociates on Pt-Sn surfaces and lead to Sn oxidation.•The alloy thereby segregates into Pt dispersed in SnOx.•The process is favoured at low temperatures and in the absence of ...H2.•The alloy can be reformed if temperature is increased or exposed to H2.
Identifying the causes of the segregation of Pt-based alloy nanoparticles is crucial for the design and operation of the corresponding catalysts and electrodes. This article describes a yet unreported mode of alloy segregation upon exposure to CO. In situ IR studies indicated that Pt-Sn alloy nanoparticles were not stable under (i) H2-free CO at any temperature or (ii) CO/H2 mixtures at temperatures below ca. 450 K. This was rationalized by the ability of Pt to dissociate CO. The oxygen adatoms readily reacted with metallic Sn to form a SnOx species, leading to Pt-Sn segregation, alongside carbon deposition. XPS and XANES analyses confirmed Sn reoxidation. While a contamination by traces of O2 at the sub-ppm level cannot be excluded, the data reported indicate that the structural modifications undergone by the Pt-Sn nanoparticles are more consistent with a reaction involving CO rather than one involving O2. In particular, the XPS analysis after CO exposure revealed an increased fraction of graphitic carbon, while that of oxidized carbon decreased. Thermodynamic calculations indicate that the oxidation of tin by CO, with concomitant carbon formation (Sn + CO → SnO + C) is as favourable as Boudouard reaction (2 CO → CO2 + C) at low temperatures. Alloy stability in the presence of CO must therefore be a concern when CO dissociation is possible and one of the alloyed metal is oxophilic.
A
bstract
The quantum interference between the decays of entangled neutral kaons is studied in the process
ϕ
→ K
S
K
L
→
π
+
π
−
π
+
π
−
, which exhibits the characteristic Einstein-Podolsky-Rosen ...correlations that prevent both kaons to decay into
π
+
π
−
at the same time. This constitutes a very powerful tool for testing at the utmost precision the quantum coherence of the entangled kaon pair state, and to search for tiny decoherence and
CPT
violation effects, which may be justified in a quantum gravity framework.
The analysed data sample was collected with the KLOE detector at DAΦNE, the Frascati
ϕ
-factory, and corresponds to an integrated luminosity of about 1.7 fb
−
1
, i.e. to about 1
.
7 × 10
9
ϕ
→ K
S
K
L
decays produced. From the fit of the observed ∆
t
distribution, being ∆
t
the difference of the kaon decay times, the decoherence and
CPT
violation parameters of various phenomenological models are measured with a largely improved accuracy with respect to previous analyses.
The results are consistent with no deviation from quantum mechanics and
CPT
symmetry, while for some parameters the precision reaches the interesting level at which — in the most optimistic scenarios — quantum gravity effects might show up. They provide the most stringent limits up to date on the considered models.
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