276 research outputs found
Dilution versus pollution in watercourses affected by acid mine drainage: a graphic model for the Iberian Pyrite Belt (SW Spain)
The aim of this study was to chemically characterize
the water quality impacts of the 88 acid mine drainage
(AMD) generating mines in the Spanish sector of the Iberian
Pyrite Belt (IPB). This was necessary because the Water
Framework Directive of the European Union and the hydrological
plans of the Tinto, Odiel, and Piedras river basins
require that water quality be improved enough to allow at
least some of the rivers in the IPB to sustain healthy fish
populations by 2027. The results indicate a clear decrease in
metals, arsenic, and sulfate concentrations and increased pH
between the AMD-sources and the river channels.info:eu-repo/semantics/publishedVersio
Resultados a largo plazo de intervención de Magnuson-Stack modificada para la luxación anterior recidivante de hombro
Los autores han realizado una revisión largo plazo versus corto plazo
con 29 pacientes tratados mediante la técnica de Magnuson-Stack por luxación
anterior recidivante de hombro. Se encontró un empobrecimiento de
los resultados globales, observándose empeoramiento de la estabilidad
(pasan del 90.47% de resultados excelentes al 58.62%, así como del 9.52 de
resultados malos al 31.03%), aumento del arco de movilidad (movilidad
excelente del 57.14 al 82.75%), permaneciendo la función prácticamente
inalterada.Twenty-nine patients with recurrent shoulder dislocation trailed
surgicaly by modified Magnuson-Stack procedure are colected.
The authors made a long-term versus short-term review of
results. They have found a worsening of results in the total longterm
review. They observe a worsening of the stability (90.47%
excellent results in short-term but 58.62% in long-term) (9.52% bad
results in short-term but 31.03% in long-term). There are an increase
of range mobility (57.14% excellent in short-term versus 82.75%
in long-term). The function remain unchanged
Pathogenic strains of Shewanella putrefaciens contain plasmids that are absent in the probiotic strain Pdp11
Shewanella putrefaciens Pdp11 is a strain described as a probiotic for use in aquaculture. However, S. putrefaciens includes strains reported to be pathogenic or saprophytic to fish. Although the probiotic trait has been related to the presence of a group of genes in its genome, the existence of plasmids that could determine the probiotic or pathogenic character of this bacterium is unknown. In the present work, we searched for plasmids in several strains of S. putrefaciens that differ in their pathogenic and probiotic character. Under the different conditions tested, plasmids were only found in two of the five pathogenic strains, but not in the probiotic strain nor in the two saprophytic strains tested. Using a workflow integrating Sanger and Illumina reads, the complete consensus sequences of the plasmids were obtained. Plasmids differed in one ORF and encoded a putative replication initiator protein of the repB family, as well as proteins related to plasmid stability and a toxin-antitoxin system. Phylogenetic analysis showed some similarity to functional repB proteins of other Shewanella species. The implication of these plasmids in the probiotic or pathogenic nature of S. putrefaciens is discussed
Extinction of Hepatitis C Virus by Ribavirin in Hepatoma Cells Involves Lethal Mutagenesis
Lethal mutagenesis, or virus extinction produced by enhanced mutation rates, is under investigation as an antiviral strategy that aims at counteracting the adaptive capacity of viral quasispecies, and avoiding selection of antiviral-escape mutants. To explore lethal mutagenesis of hepatitis C virus (HCV), it is important to establish whether ribavirin, the purine nucleoside analogue used in anti-HCV therapy, acts as a mutagenic agent during virus replication in cell culture. Here we report the effect of ribavirin during serial passages of HCV in human hepatoma Huh-7.5 cells, regarding viral progeny production and complexity of mutant spectra. Ribavirin produced an increase of mutant spectrum complexity and of the transition types associated with ribavirin mutagenesis, resulting in HCV extinction. Ribavirin-mediated depletion of intracellular GTP was not the major contributory factor to mutagenesis since mycophenolic acid evoked a similar decrease in GTP without an increase in mutant spectrum complexity. The intracellular concentration of the other nucleoside-triphosphates was elevated as a result of ribavirin treatment. Mycophenolic acid extinguished HCV without an intervening mutagenic activity. Ribavirin-mediated, but not mycophenolic acid-mediated, extinction of HCV occurred via a decrease of specific infectivity, a feature typical of lethal mutagenesis. We discuss some possibilities to explain disparate results on ribavirin mutagenesis of HCV
Linear approach to the orbiting spacecraft thermal problem
We develop a linear method for solving the nonlinear differential equations
of a lumped-parameter thermal model of a spacecraft moving in a closed orbit.
Our method, based on perturbation theory, is compared with heuristic
linearizations of the same equations. The essential feature of the linear
approach is that it provides a decomposition in thermal modes, like the
decomposition of mechanical vibrations in normal modes. The stationary periodic
solution of the linear equations can be alternately expressed as an explicit
integral or as a Fourier series. We apply our method to a minimal thermal model
of a satellite with ten isothermal parts (nodes) and we compare the method with
direct numerical integration of the nonlinear equations. We briefly study the
computational complexity of our method for general thermal models of orbiting
spacecraft and conclude that it is certainly useful for reduced models and
conceptual design but it can also be more efficient than the direct integration
of the equations for large models. The results of the Fourier series
computations for the ten-node satellite model show that the periodic solution
at the second perturbative order is sufficiently accurate.Comment: 20 pages, 11 figures, accepted in Journal of Thermophysics and Heat
Transfe
High-temperature anti-Invar behavior of gamma-Fe precipitates in Fe_xCu_(100-x) solid solutions: Ferromagnetic phases
High-temperature magnetization and neutron diffraction measurements on metastable Fe_xCu_(100-x) solid solutions have recently shown to imply that γ-Fe precipitates present ferromagnetic anti-Invar behavior. For this reason, we have studied the ferromagnetic phases of γ-Fe in moment-volume parameter space, using the general potential linearized-augmented plane-wave method and the fixed spin moment procedure in order to calculate the corresponding total energy. We find that only two ferromagnetic phases (one related to a low- spin state and the other to a high-spin state) can exist and even coexist in limited volume ranges (3.55-3.59 Å). Hence, our results provide a "revisited" version of the local spin density calculations used in the early article by Moruzzi [Phys. Rev. B 34, 1784 (1986)]. In addition, the fixed spin moment method-using an energy-moment-volume space representation-allows us to conclude that the high-spin state is the ground state of the gamma-Fe precipitates, as the anti-Invar behavior is an intrinsic property of these states. This simple scenario seems to adequately describe the perplexing phenomenology recently observed on Fe_xCu_(100-x) solid solutions
Treatment patterns and outcomes among nontransplant newly diagnosed multiple myeloma patients in Spain
Aim: To describe treatment patterns and outcomes in nontransplant newly diagnosed multiple myeloma (NDMM) patients in Spain. Methods: This retrospective study included two cohorts of NDMM patients diagnosed between 1 January 2012 to 31 December 2013 and 1 April 2016 to 31 March 2017. Results: Among 113 patients, proteasome inhibitor (PI) + alkylator combinations (49%) and PI-based regimens without an alkylator (30%) were the most common first-line (1L) therapies. Use of PI + immunomodulatory drug-based regimens increased between the cohorts; PI-based regimens without an alkylator/immunomodulatory drug decreased. Use of 1L oral regimens was low but increased over time; use of maintenance therapy was low across both periods. Median 1L duration of treatment was 6.9 months. Conclusion: Short 1L duration of treatment and low use of 1L oral regimens and maintenance therapy highlight unmet needs in NDMM. © 2021 The Authors
Formation of a magnetite/hematite epitaxial bilayer generated with low energy ion bombardment
We have used a low-energy ion bombardment to fabricate an epitaxial single-crystalline magnetite/hematite bilayer grown on Au(111). This non-conventional fabrication method involves the transformation of the upper layers of a single-crystalline hematite thin film to single-crystalline magnetite, a process driven by the preferential sputtering of oxygen atoms and favoured by the good structural matching of both phases. We show the reversibility of the transformation between hematite and magnetite, always keeping the epitaxial and single- crystalline character of the films. The magnetic characterization of the bilayer grown using this method shows that the magnetic response is mainly determined by the magnetite thin film, exhibiting a high coercivity. Published by AIP Publishing
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