2 resultados para ultra-high-vacuum magneto-optical trap

em Universidad de Alicante


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Context. It appears that most (if not all) massive stars are born in multiple systems. At the same time, the most massive binaries are hard to find owing to their low numbers throughout the Galaxy and the implied large distances and extinctions. Aims. We want to study LS III +46 11, identified in this paper as a very massive binary; another nearby massive system, LS III +46 12; and the surrounding stellar cluster, Berkeley 90. Methods. Most of the data used in this paper are multi-epoch high S/N optical spectra, although we also use Lucky Imaging and archival photometry. The spectra are reduced with dedicated pipelines and processed with our own software, such as a spectroscopic-orbit code, CHORIZOS, and MGB. Results. LS III +46 11 is identified as a new very early O-type spectroscopic binary [O3.5 If* + O3.5 If*] and LS III +46 12 as another early O-type system [O4.5 V((f))]. We measure a 97.2-day period for LS III +46 11 and derive minimum masses of 38.80 ± 0.83 M⊙ and 35.60 ± 0.77 M⊙ for its two stars. We measure the extinction to both stars, estimate the distance, search for optical companions, and study the surrounding cluster. In doing so, a variable extinction is found as well as discrepant results for the distance. We discuss possible explanations and suggest that LS III +46 12 may be a hidden binary system where the companion is currently undetected.

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This randomized and controlled trial investigated whether the increase in elite training at different altitudes altered the oxidative stress biomarkers of the nervous system. This is the first study to investigate four F4-neuroprostanes and four F2-dihomo-isoprostanes quantified in 24-hour urine. The quantification was carried out by Ultra High Pressure Liquid Chromatography-triple Quadrupole-Tandem Mass Spectrometry (UHPLC-QqQ-MS/MS). Sixteen elite triathletes agreed to participate in the project. They were randomized in two groups, a group submitted to Altitude Training (n=8) and a group submitted to Sea Level Training (n=8), with a Control group of non-athletes (n=8). After experimental period, the Altitude Training group triathletes gave significant data: 17-epi-17-F2t-dihomo-IsoP (from 5.2 ± 1.4 µg/mL 24 h-1 to 6.6 ± 0.6 µg/mL 24 h-1), ent-7(RS)-7-F2t-dihomo-IsoP (from 6.6 ± 1.7 µg/mL 24 h-1 to 8.6 ± 0.9 µg /mL 24 h-1), and ent-7-epi-7-F2t-dihomo-IsoP (from 8.4 ± 2.2 µg/mL 24 h-1 to 11.3 ± 1.8 µg/mL 24 h-1) increased, while, of the neuronal degeneration-related compounds, only 10-epi-10-F4t-NeuroP (8.4 ± 1.7 µg/mL 24 h-1) and 10-F4t-NeuroP (5.2 ± 2.9 µg/mL 24 h-1) were detected in this group. For the control group and sea level training groups, no significant changes had occurred at the end of the 2-weeks experimental period. Therefore, and as the main conclusion, the training at moderate altitude increased the F4-NeuroPs- and F2-dihomo-isoPs-related oxidative damage of the central nervous system (CNS) compared to similar training at sea level.