5,515 research outputs found
Behavior of tumors under nonstationary theraphy
We present a model for the interaction dynamics of lymphocytes-tumor cells
population. This model reproduces all known states for the tumor. Futherly,we
develop it taking into account periodical immunotheraphy treatment with
cytokines alone. A detailed analysis for the evolution of tumor cells as a
function of frecuency and theraphy burden applied for the periodical treatment
is carried out. Certain threshold values for the frecuency and applied doses
are derived from this analysis. So it seems possible to control and reduce the
growth of the tumor. Also, constant values for cytokines doses seems to be a
succesful treatment.Comment: 6 pages, 7 figure
Structural stability of Fe5Si3 and Ni2Si studied by high-pressure x-ray diffraction and ab initio total-energy calculations
We performed high-pressure angle dispersive x-ray diffraction measurements on
Fe5Si3 and Ni2Si up to 75 GPa. Both materials were synthesized in bulk
quantities via a solid-state reaction. In the pressure range covered by the
experiments, no evidence of the occurrence of phase transitions was observed.
On top of that, Fe5Si3 was found to compress isotropically, whereas an
anisotropic compression was observed in Ni2Si. The linear incompressibility of
Ni2Si along the c-axis is similar in magnitude to the linear incompressibility
of diamond. This fact is related to the higher valence-electron charge density
of Ni2Si along the c-axis. The observed anisotropic compression of Ni2Si is
also related to the layered structure of Ni2Si where hexagonal layers of Ni2+
cations alternate with graphite-like layers formed by (NiSi)2- entities. The
experimental results are supported by ab initio total-energy calculations
carried out using density functional theory and the pseudopotential method. For
Fe5Si3, the calculations also predicted a phase transition at 283 GPa from the
hexagonal P63/mcm phase to the cubic structure adopted by Fe and Si in the
garnet Fe5Si3O12. The room-temperature equations of state for Fe5Si3 and Ni2Si
are also reported and a possible correlation between the bulk modulus of iron
silicides and the coordination number of their minority element is discussed.
Finally, we report novel descriptions of these structures, in particular of the
predicted high-pressure phase of Fe5Si3 (the cation subarray in the garnet
Fe5Si3O12), which can be derived from spinel Fe2SiO4 (Fe6Si3O12).Comment: 44 pages, 13 figures, 3 Table
POTENTIAL INCLUSION OF MACARONESIAN SEAWEED WRACKS IN DIETS FOR GILTHEAD SEABREAM (SPARUS AURATA).
Instantons and Condensate
We argue that the is similar to .Comment: 6 pages, 1 fig., 1 tab., RevTeX to be use
The strong coupling constant at small momentum as an instanton detector
We present a study of at small p computed from the lattice.
It shows a dramatic law which can be understood within an
instanton liquid model. In this framework the prefactor gives a direct measure
of the instanton density in thermalised configurations. A preliminary result
for this density is 5.27(4) fm^{-4}.Comment: 12 pages, 4 figure
Exploring the high-pressure behavior of the three known polymorphs of BiPO4: Discovery of a new polymorph
The following article appeared in Journal of Applied Physics and may be found at http://dx.doi.org/10.1063/1.4914407 . Authors own version of final article on e-print serversWe have studied the structural behavior of bismuth phosphate under compression. We performed x-ray powder diffraction measurements up to 31.5 GPa and ab initio calculations. Experiments were carried out on different polymorphs: trigonal (phase I) and monoclinic (phases II and III). Phases I and III, at low pressure (P < 0.2-0.8 GPa), transform into phase II, which has a monazite-type structure. At room temperature, this polymorph is stable up to 31.5 GPa. Calculations support these findings and predict the occurrence of an additional transition from the monoclinic monazite-type to a tetragonal scheelite-type structure (phase IV). This transition was experimentally found after the simultaneous application of pressure (28 GPa) and temperature (1500 K), suggesting that at room temperature the transition might by hindered by kinetic barriers. Calculations also predict an additional phase transition at 52 GPa, which exceeds the maximum pressure achieved in the experiments. This transition is from phase IV to an orthorhombic barite-type structure (phase V). We also studied the axial and bulk compressibility of BiPO4. Room-temperature pressure-volume equations of state are reported. BiPO4 was found to be more compressible than isomorphic rare-earth phosphates. The discovered phase IV was determined to be the less compressible polymorph of BiPO4. On the other hand, the theoretically predicted phase V has a bulk modulus comparable with that of monazite-type BiPO4. Finally, the isothermal compressibility tensor for the monazite-type structure is reported at 2.4 GPa showing that the direction of maximum compressibility is in the (0 1 0) plane at approximately 15 degrees (21 degrees) to the a axis for the case of our experimental (theoretical) study. (C) 2015 AIP Publishing LLC.Research supported by the Spanish government MINECO under Grant No: MAT2013-46649-C4-1/2/3-P and by Generalitat Valenciana under Grants Nos. GVA-ACOMP-2013-1012 and GVA-ACOMP/2014/243. B.G.-D. thanks the financial support from MEC through FPI program. Experiments were performed at MSPD beamline at ALBA Synchrotron Light Facility with the collaboration of ALBA staff.Errandonea, D.; Gomis, O.; Santamaría Pérez, D.; García-Domene, B.; Muñoz, A.; Rodríguez-Hernández, P.; Achary, SN.... (2015). Exploring the high-pressure behavior of the three known polymorphs of BiPO4: Discovery of a new polymorph. Journal of Applied Physics. 117:105902-1-105902-9. https://doi.org/10.1063/1.4914407S105902-1105902-911
Role of TRAILR1 and TNFR1A polymorphisms in the susceptibility and pharmacogenetics of rheumatoid arthritis and ankylosing spondylitis patients treated with infliximab
Hospital Virtual: Sistema de información clínica y telecuidado de pacientes VIH/SIDA basado en tecnologías Web 2.0
Este artículo describe el desarrollo de un nuevo sistema de información clínica y telecuidado de pacientes VIH/SIDA que se encuentra implantado en rutina clínica dentro del Servicio de Enfermedades Infecciosas del Hospital Clínic de Barcelona. El proyecto surge ante la necesidad de unificar el sistema de información departamental del servicio y un sistema de telemedicina instalado en el hospital en 2004. Para ello se han diseñado e implementado nuevas bases de datos y dos sistemas específicos para uso de profesionales y pacientes. Además, se ha realizado una integración con el Sistema de Información del Hospital (HIS) permitiendo el acceso a todos los datos requeridos de los pacientes desde una única aplicación. Este nuevo sistema está al servicio de más de 70 profesionales sanitarios que realizan una media de 150 consultas al día disponiendo de información clínica de más de 8000 pacientes
Polarization-tuneable excitonic spectral features in the optoelectronic response of atomically thin ReS2
The low crystal symmetry of rhenium disulphide (ReS2) leads to the emergence
of dichroic optical and optoelectronic response, absent in other layered
transition metal dichalcogenides, which could be exploited for device
applications requiring polarization resolution. To date, spectroscopy studies
on the optical response of ReS2 have relied almost exclusively in
characterization techniques involving optical detection, such as
photoluminescence, absorbance, or reflectance spectroscopy. However, to realize
the full potential of this material, it is necessary to develop knowledge on
its optoelectronic response with spectral resolution. In this work, we study
the polarization-dependent photocurrent spectra of few-layer ReS2
photodetectors, both in room conditions and at cryogenic temperature. Our
spectral measurements reveal two main exciton lines at energies matching those
reported for optical spectroscopy measurements, as well as their excited
states. Moreover, we also observe an additional exciton-like spectral feature
with a photoresponse intensity comparable to the two main exciton lines. We
attribute this feature, not observed in earlier photoluminescence measurements,
to a non-radiative exciton transition. The intensities of the three main
exciton features, as well as their excited states, modulate with linear
polarization of light, each one acquiring maximal strength at a different
polarization angle. We have performed first-principles exciton calculations
employing the Bethe-Salpeter formalism, which corroborate our experimental
findings. Our results bring new perspectives for the development of ReS2-based
nanodevices
Oligonucleotide Based Magnetic Bead Capture of Onchocerca volvulus DNA for PCR Pool Screening of Vector Black Flies
The absence of infective larvae of Onchocerca volvulus in the black fly vector of this parasite is a major criterion used to certify that transmission has been eliminated in a focus. This process requires screening large numbers of flies. Currently, this is accomplished by screening pools of flies using a PCR-based assay. The number of flies that may be included in each pool is currently limited by the DNA purification process to 50 flies for Latin American vectors and 100 flies for African vectors. Here, we describe a new method for DNA purification that relies upon a specific oligonucleotide to capture and immobilize the parasite DNA on a magnetic bead. This method permits the reliable detection of a single infective larva of O. volvulus in pools containing up to 200 individual flies. The method described here will dramatically improve the efficiency of pool screening of vector black flies, making the process of elimination certification easier and less expensive to implement
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