5,669 research outputs found
Incidents control in radiotherapy oncology
Primer pla de l'escut del monarca del s. XVI,
conservat i ubicat a la porta de la UB. Mesura
1,60 x 2,20 metre si és de pedra sorrenca
Production and Characterization of a new Copper(II) Propanoate-Isonicotinamide Adduct obtained via Slow Evaporation and using Supercritical CO2 as an Antisolvent
A new adduct of isonicotinamide (INA) with copper(II) propanoate [Cu(C3)2] was prepared [Cu2(C3)4(INA)4] using two different methods. This type of compound shows high fungicidal activity. Solvent evaporation from ethanol rendered crystals suitable for single-crystal X-ray diffraction. Furthermore, a new semicontinuous method capable of simultaneous crystallization and micronization of the adduct using supercritical CO2, the supercritical antisolvent technique (SAS), was also assessed. Crystals were characterized using powder X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis coupled with mass spectrometry, scanning electron microscopy, and microelemental analysis. In the adduct, two copper(II) ions are coordinated through two bridging and two chelating carboxylates to the propanoate anions forming approximately a plane. Each metal ion is then coordinated with the pyridine nitrogen of two different INA molecules that behave as monodentate ligands. The amide groups of the INA form H-bonds with other amide and carboxylate groups forming a molecular crystal with a three-dimensional H-bond arrangement of the binuclear units. With the SAS technique, crystals 100-fold smaller than those obtained by slow evaporation were obtained, proving SAS as a suitable method for mixed-ligand complexes preparation with reduced particle size and therefore expected bioavailability enhancement
New Evidence on Regucalcin, Body Composition, and Walking Ability Adaptations to Multicomponent Exercise Training in Functionally Limited and Frail Older Adults
Background: Regucalcin, or senescence marker protein-30 (SMP30), is a Ca2+-binding protein with multiple functions reported in the literature. Physical exercise has been shown to improve aging markers; nevertheless, SMP30 in humans has not been extensively researched. Older adults experience a decline in functional capacity and body composition. The purpose of this study was to examine the effects of a multicomponent training (MCT) program on SMP30 and its regulation of walking ability and body composition in functionally limited, frail, and pre-frail older adults. Methods: A total of 34 older adults (aged 80.3 +/- 6.1 years) were divided into an intervention group (IG = 20) and control group (CG = 14). The IG performed a supervised MCT (strength, endurance, balance, coordination, and flexibility) program for 6 months, 3 days per week, whereas the CG continued their normal lives without any specific physical training. SMP30 was analyzed in plasma after 3 and 6 months of MCT, while some physical fitness variables (Timed Up and Go (TUG) and 6-min walk test (6MWT)) and body composition (fat mass and lean mass) were measured at baseline, as well as after 3 months and 6 months of MCT. Results: No significant changes were observed in SPM30 between the IG (877.5 a.u. to 940.5 a.u., respectively) and CG (790.4 a.u. to 763.8 a.u., respectively). Moreover, no SMP30 differences were found between groups after 3 and 6 months of MCT. The IG improved significantly in the 6MWT after 3 months (472.2 +/- 84.2 m) compared to baseline (411.2 +/- 75.2 m). The IG also significantly enhanced their TUG performance after 3 months (7.6 +/- 1.6 s) and 6 months (7.3 +/- 1.8 s) of training compared to baseline (9.3 +/- 3.2 s) (all, p < 0.001). There were no significant differences in body composition between the IG and CG through the 6 months of MCT. Conclusions: The present study suggests that MCT did not change SMP30 levels from 3 to 6 months, where there were changes in neither walking ability nor body composition; however, MCT was effective in improving 6MWT and TUG performance from baseline to 3 months
Three-body structure of low-lying 18Ne states
We investigate to what extent 18Ne can be descibed as a three-body system
made of an inert 16O-core and two protons. We compare to experimental data and
occasionally to shell model results. We obtain three-body wave functions with
the hyperspherical adiabatic expansion method. We study the spectrum of 18Ne,
the structure of the different states and the predominant transition strengths.
Two 0+, two 2+, and one 4+ bound states are found where they are all known
experimentally. Also one 3+ close to threshold is found and several negative
parity states, 1-, 3-, 0-, 2-, most of them bound with respect to the 16O
excited 3- state. The structures are extracted as partial wave components, as
spatial sizes of matter and charge, and as probability distributions.
Electromagnetic decay rates are calculated for these states. The dominating
decay mode for the bound states is E2 and occasionally also M1.Comment: 17 pages, 5 figures (version to appear in EPJA
The SLC7A11: sperm mitochondrial function and non-canonical glutamate metabolism
Spermatozoa are redox-regulated cells, and stallion spermatozoa, in particular, present an intense mitochondrial activity in which large amounts of reactive oxygen species (ROS) are produced. To maintain the redox potential under physiological conditions, sophisticated mechanisms ought to be present, particularly in the mitochondria. In the present study, we investigated the role of the SLC7A11 antiporter. This antiporter exchanges intracellular glutamate for extracellular cystine. In the spermatozoa, cystine is reduced to cysteine and used for GSH synthesis. The importance of the antiporter for mitochondrial functionality was studied using flow cytometry and UHPLC/MS/MS approaches. Intracellular GSH increased in the presence of cystine, but was reduced in the presence of Buthionine sulphoximine (BSO), a γ-glutamylcysteine synthetase inhibitor (P < 0.001). Inhibition of the SLC7A11 antiporter with sulfasalazine caused a dramatic drop in intracellular GSH (P < 0.001) and in the percentage of spermatozoa showing active mitochondria (P < 0.001). These findings suggest that proper functionality of this antiporter is required for the mitochondrial function of spermatozoa. We also describe that under some conditions, glutamate may be metabolized following non-conventional pathways, also contributing to sperm functionality. We provide evidences, that the stallion spermatozoa have important metabolic plasticity, and also of the relation between redox regulation and metabolic regulation. These findings may have important implications for the understanding of sperm biology and the development of new strategies for sperm conservation and treatment of male factor infertility
Towards a new generation axion helioscope
We study the feasibility of a new generation axion helioscope, the most
ambitious and promising detector of solar axions to date. We show that large
improvements in magnetic field volume, x-ray focusing optics and detector
backgrounds are possible beyond those achieved in the CERN Axion Solar
Telescope (CAST). For hadronic models, a sensitivity to the axion-photon
coupling of \gagamma\gtrsim {\rm few} \times 10^{-12} GeV is
conceivable, 1--1.5 orders of magnitude beyond the CAST sensitivity. If axions
also couple to electrons, the Sun produces a larger flux for the same value of
the Peccei-Quinn scale, allowing one to probe a broader class of models. Except
for the axion dark matter searches, this experiment will be the most sensitive
axion search ever, reaching or surpassing the stringent bounds from SN1987A and
possibly testing the axion interpretation of anomalous white-dwarf cooling that
predicts of a few meV. Beyond axions, this new instrument will probe
entirely unexplored ranges of parameters for a large variety of axion-like
particles (ALPs) and other novel excitations at the low-energy frontier of
elementary particle physics.Comment: 37 pages, 11 figures, accepted for publication in JCA
The International Axion Observatory (IAXO)
The International Axion Observatory (IAXO) is a new generation axion
helioscope aiming at a sensitivity to the axion-photon coupling of a few
10 GeV, i.e. 1 - 1.5 orders of magnitude beyond the one currently
achieved by CAST. The project relies on improvements in magnetic field volume
together with extensive use of x-ray focusing optics and low background
detectors, innovations already successfully tested in CAST. Additional physics
cases of IAXO could include the detection of electron-coupled axions invoked to
solve the white dwarfs anomaly, relic axions, and a large variety of more
generic axion-like particles (ALPs) and other novel excitations at the
low-energy frontier of elementary particle physics. This contribution is a
summary of our paper [1] to which we refer for further details.Comment: 4 pages, 2 figures. To appear in the proceedings of the 7th Patras
Workshop on Axions, WIMPs and WISPs, Mykonos, Greece, 201
CAST constraints on the axion-electron coupling
In non-hadronic axion models, which have a tree-level axion-electron
interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton
scattering, and axio-recombination, the "BCA processes." Based on a new
calculation of this flux, including for the first time axio-recombination, we
derive limits on the axion-electron Yukawa coupling g_ae and axion-photon
interaction strength g_ag using the CAST phase-I data (vacuum phase). For m_a <
10 meV/c2 we find g_ag x g_ae< 8.1 x 10^-23 GeV^-1 at 95% CL. We stress that a
next-generation axion helioscope such as the proposed IAXO could push this
sensitivity into a range beyond stellar energy-loss limits and test the
hypothesis that white-dwarf cooling is dominated by axion emission
Operations of and Future Plans for the Pierre Auger Observatory
Technical reports on operations and features of the Pierre Auger Observatory,
including ongoing and planned enhancements and the status of the future
northern hemisphere portion of the Observatory. Contributions to the 31st
International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
- …