647 research outputs found
Effect of band-filling and structural distortions on the Curie temperature of Fe-Mo double perovkites
By means of high resolution neutron powder diffraction at low temperature we
have characterized the structural details of
() and () series of compounds. This study reveals a similar variation of the mean
bond-angle \FeOMo in both series. In contrast, the mean bond-distance \FeMoO\
increases with La but not with Ca substitution. Both series also present a
different evolution of the Curie temperature (), which raises in the La
series and slightly decreases in the Ca one. We thus conclude that the
enhancement of in the La series is due to the electron filling of the
conduction band and a concomitant rising of the density of states at the Fermi
level.Comment: Revtex, 4 Journal pages, 2 figures, 1 tabl
Unconventional low-energy SUSY from warped geometry
Supersymmetric models with a warped fifth spatial dimension can solve the
hierarchy problem, avoiding some shortcomings of non-supersymmetric
constructions, and predict a plethora of new phenomena at typical scales Lambda
not far from the electroweak scale (Lambda ~ a few TeV). In this paper we
derive the low-energy effective theories of these models, valid at energies
below Lambda. We find that, in general, such effective theories can deviate
significantly from the Minimal Supersymmetric Standard Model (MSSM) or other
popular extensions of it, like the NMSSM: they have non-minimal Kaehler
potentials (even in the Mp -> \infty limit), and the radion is coupled to the
visible fields, both in the superpotential and the Kaehler potential, in a
non-trivial (and quite model-independent) fashion. The corresponding
phenomenology is pretty unconventional, in particular the electroweak breaking
occurs in a non-radiative way, with tan beta \simeq 1 as a quite robust
prediction, while the mass of the lightest Higgs boson can be as high as ~ 700
GeV.Comment: 53 pages, 2 ps figure
Exploiting oxidative phosphorylation to promote the stem and immunoevasive properties of pancreatic cancer stem cells
Pancreatic ductal adenocarcinoma (PDAC), the fourth leading cause of cancer death, has a 5-year survival rate of approximately 7â9%. The ineffectiveness of anti-PDAC therapies is believed to be due to the existence of a subpopulation of tumor cells known as cancer stem cells (CSCs), which are functionally plastic, and have exclusive tumorigenic, chemoresistant and metastatic capacities. Herein, we describe a 2D in vitro system for long-term enrichment of pancreatic CSCs that is amenable to biological and CSC-specific studies. By changing the carbon source from glucose to galactose in vitro, we force PDAC cells to utilize OXPHOS, resulting in enrichment of CSCs defined by increased CSC biomarker and pluripotency gene expression, greater tumorigenic potential, induced but reversible quiescence, increased OXPHOS activity, enhanced invasiveness, and upregulated immune evasion properties. This CSC enrichment method can facilitate the discovery of new CSC-specific hallmarks for future development into targets for PDAC-based therapies
Assessment of Platelet REACtivity After Transcatheter Aortic Valve Replacement : The REAC-TAVI Trial
The REAC-TAVI (Assessment of platelet REACtivity after Transcatheter Aortic Valve Implantation) trial enrolled patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) pre-treated with aspirin + clopidogrel, aimed to compare the efficacy of clopidogrel and ticagrelor in suppressing high platelet reactivity (HPR) after TAVI. Current recommendations support short-term use of aspirin + clopidogrel for patients with severe AS undergoing TAVR despite the lack of compelling evidence. This was a prospective, randomized, multicenter investigation. Platelet reactivity was measured at 6 different time points with the VerifyNow assay (Accriva Diagnostics, San Diego, California). HPR was defined as (P2Y reaction units (PRU) âĽ208. Patients with HPR before TAVR were randomized to either aspirin + ticagrelor or aspirin + clopidogrel for 3 months. Patients without HPR continued with aspirin + clopidogrel (registry cohort). The primary endpoint was non-HPR status (PRU <208) in âĽ70% of patients treated with ticagrelor at 90 days post-TAVR. A total of 68 patients were included. Of these, 48 (71%) had HPR (PRU 273 Âą 09) and were randomized to aspirin + ticagrelor (n = 24, PRU 277 Âą 08) or continued with aspirin + clopidogrel (n = 24, PRU 269 Âą 49). The remaining 20 patients (29%) without HPR (PRU 133 Âą 12) were included in the registry. Overall, platelet reactivity across all the study time points after TAVR was lower in patients randomized to ticagrelor compared with those treated with clopidogrel, including those enrolled in the registry (p < 0.001). The primary endpoint was achieved in 100% of patients with ticagrelor compared with 21% with clopidogrel (p < 0.001). Interestingly, 33% of clopidogrel responder patients at baseline developed HPR status during the first month after TAVR. HPR to clopidogrel is present in a considerable number of patients with AS undergoing TAVR. Ticagrelor achieves a better and faster effect, providing sustained suppression of HPR to these patients. (Platelet Reactivity After TAVI: A Multicenter Pilot Study [REAC-TAVI]; NCT02224066
Nonlinear analysis of the pressure field in industrial buildings with curved metallic roofs due to the wind effect by FEM
Dwell-time distributions in quantum mechanics
Some fundamental and formal aspects of the quantum dwell time are reviewed,
examples for free motion and scattering off a potential barrier are provided,
as well as extensions of the concept. We also examine the connection between
the dwell time of a quantum particle in a region of space and flux-flux
correlations at the boundaries, as well as operational approaches and
approximations to measure the flux-flux correlation function and thus the
second moment of the dwell time, which is shown to be characteristically
quantum, and larger than the corresponding classical moment even for freely
moving particles.Comment: To appear in "Time in Quantum Mechanics, Vol. 2", Springer 2009, ed.
by J. G. Muga, A. Ruschhaupt and A. del Camp
Human immunodeficiency virus/hepatits C virus coinfection in Spain: Elimination is feasible, but the burden of residual cirrhosis will be significant
Background
We assessed the prevalence of antibodies against hepatitis C virus (HCV-Abs) and active HCV infection in patients infected with human immunodeficiency virus (HIV) in Spain in 2016 and compared the results with those of similar studies performed in 2002, 2009, and 2015.
Methods
The study was performed in 43 centers during October-November 2016. The sample was estimated for an accuracy of 2% and selected by proportional allocation and simple random sampling. During 2016, criteria for therapy based on direct-acting antiviral agents (DAA) were at least significant liver fibrosis, severe extrahepatic manifestations of HCV, and high risk of HCV transmissibility.
Results
The reference population and the sample size were 38904 and 1588 patients, respectively. The prevalence of HCV-Abs in 2002, 2009, 2015, and 2016 was 60.8%, 50.2%, 37.7%, and 34.6%, respectively (P trend <.001, from 2002 to 2015). The prevalence of active HCV in 2002, 2009, 2015, and 2016 was 54.0%, 34.0%, 22.1%, and 11.7%, respectively (P trend <.001). The anti-HCV treatment uptake in 2002, 2009, 2015, and 2016 was 23.0%, 48.0%, 59.3%, and 74.7%, respectively (P trend <.001). In 2016, HCV-related cirrhosis was present in 7.6% of all HIV-infected individuals, 15.0% of patients with active HCV, and 31.5% of patients who cleared HCV after anti-HCV therapy.
Conclusions
Our findings suggest that with universal access to DAA-based therapy and continued efforts in prevention and screening, it will be possible to eliminate active HCV among HIV-infected individuals in Spain in the short term. However, the burden of HCV-related cirrhosis will continue to be significant among HIV-infected individuals
CaracterizaciĂłn de la pĂşrpura trombĂłtica trombocitopĂŠnica congĂŠnita mediante tĂŠcnicas inmunolĂłgicas y moleculares: resultados de la colecciĂłn nacional del GEPTT
CO-093
IntroducciĂłn: La PĂşrpura TrombĂłtica TrombocitopĂŠnica congĂŠnita (PTTc) es una enfermedad ultra-rara caracterizada por un dĂŠficit severo de la enzima ADAMTS13 como consecuencia de mutaciones heredadas de forma autosĂłmica recesiva en el gen ADAMTS13 (9q34). En este estudio, desarrollado dentro del Grupo Cooperativo EspaĂąol de PTT (GEPTT), se ha llevado a cabo la creaciĂłn de una colecciĂłn centralizada de muestras biolĂłgicas y su caracterizaciĂłn inmunolĂłgica y molecular para mejorar el diagnĂłstico y el manejo clĂnico de los pacientes.
MĂŠtodos: Se incluyeron en este estudio seis pacientes con diagnĂłstico clĂnico o sospecha de PTTc de diferentes hospitales espaĂąoles. Se estudiĂł la actividad de ADAMTS13 e inhibidores mediante la tĂŠcnica ELISA con el kit âTECHNOZYMÂŽ ADAMTS-13 Activity e INHâ (Technoclone). AdemĂĄs, se realizĂł test Bethesda para descartar la presencia de inhibidores no IgG. Para el estudio genĂŠtico, se implementĂł un panel de captura (SureSelect, Agilent) dirigido a la regiĂłn genĂłmica completa, incluyendo tambiĂŠn las regiones no codificantes, del gen ADAMTS13 (chr9: 136278459 - 136325025, hg19). Las librerĂas de DNA se secuenciaron con la plataforma MiSeq (IlluminaÂŽ) y el posible efecto patogĂŠnico de las variantes identificadas se estudiĂł a nivel de i) proteĂna, utilizando predictores de cambio de aminoĂĄcido (SIFT) y de estructura de la proteĂna (SwissModel) y ii) splicing, con herramientas de anĂĄlisis in silico (HSF) y validaciĂłn funcional in vitro mediante minigenes. En 3 casos se realizĂł un cariotipo molecular utilizando array de SNPs (CytoScan HD, Affymetrix) para detectar regiones de pĂŠrdida de material genĂŠtico y/o de heterocigosidad (LOH).
Resultados: La mediana de actividad de ..
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
- âŚ