1,501 research outputs found
Spin polarization induced by decoherence in a tunneling one-dimensional Rashba model
Basic questions on the nature of spin polarization in two terminal systems
and the way in which decoherence breaks Time-Reversal Symmetry (TRS) are
analyzed. We exactly solve several one-dimensional models of tunneling
electrons and show the interplay of spin precession and decay of the
wavefunction in either a U(1) magnetic field or an effective Spin-Orbit (SO)
magnetic field. Spin polarization is clearly identified as the emergence of a
spin component parallel to either magnetic field. We show that Onsager's
reciprocity is fulfilled when time reversal symmetry is present and no spin
polarization arises, no matter the barrier parameters or the SO strength.
Introducing a Buttiker's decoherence probe, that preserves unitarity of time
evolution, we show that breaking of TRS results in a strong spin polarization
for realistic SO, and barrier strengths. We discuss the significance of these
results as a very general scenario for the onset of the Chiral-Induced Spin
Selectivity effect (CISS), now possibly matching experiments in a quantitative
manner.Comment: 24 pages, 14 figure
Evaluation of Plakophilin-3 mRNA as a biomarker for detection of circulating tumor cells in gastrointestinal cancer patients
[Abstract] Background: This study aims to assess Plakophilin-3 (PKP3) as a surrogate biomarker of circulating tumor cells in patients with gastrointestinal cancer.
Methods: The primary aim is to estimate the diagnostic accuracy of PKP3 real-time reverse transcriptase-PCR in blood. Receiver operating characteristic curves were constructed. Correlations between the blood PKP3 levels and the clinicopathologic features of the study subjects were analyzed. Logistic regression was used to predict outcomes based on PKP3.
Results: Sixty-four patients with gastrointestinal cancer and 23 controls were included. The mean relative PKP3 mRNA expression was 48.45 in cancer patients and 2.8 in controls (P < 0.0001). Comparing the PKP3 levels in patients and controls, the area under the curve was 0.852 (95% confidence interval, 0.76-0.94; P < 0.0001) in receiver operating characteristic analysis. A higher blood level of PKP3 mRNA was associated with a more advanced stage (P = 0.025), pT3-4 tumors (P = 0.028), metastasis (P = 0.021), and residual (R2) disease (P = 0.037). Higher PKP3 mRNA was associated with the risk of cancer progression and death (odds ratio, 3.875; 95% confidence interval, 1.781-8.430; P = 0.001).
Conclusions: Increased PKP3 mRNA was detected in the blood of gastrointestinal cancer patients. Significant correlations were found with advanced stage, pT3-4, metastatic disease, and the residual disease status. PKP3 mRNA in blood was associated with the risk of cancer progression and death.Rede Galega de Investigación sobre Cancro Colorrectal; Grant 509025250
Circulating miR-200c as a diagnostic and prognostic biomarker for gastric cancer
[Abstract]
Background. MicroRNAs are aberrantly expressed and correlate with tumourigenesis and the progression of solid tumours. The miR-200 family determines the epithelial phenotype of cancer cells and regulates invasiveness and migration. Thus, we hypothesised that the quantitative detection of the miR-200 family as epithelial-specific microRNAs in the blood could be a useful clinical biomarker for gastric cancer (GC).
Methods. We initially validated the expression levels of miR-200a, 200b, 200c and 141 in GC cell lines (n = 2) and blood from healthy controls (n = 19) using real-time quantitative reverse transcription PCR (qRT-PCR). The microarray expression profiles of the miR-200 family in 160 paired samples of non-tumour gastric mucosae and GC were downloaded through ArrayExpress and analysed. MiR-200c was selected for clinical validation. The qRT-PCR prospective assessment of miR-200c was performed using 67 blood samples (52 stage I-IV GC patients and 15 controls); the area under the receiver operating characteristic curve (AUC-ROC) was estimated. The Kaplan-Meier and Breslow-Wilcoxon tests were used to assess the correlation of miR-200c with overall and progression-free survival (OS and PFS). Multivariate analyses were performed using the Cox model.
Results. The miR-200c blood expression levels in GC patients were significantly higher than in normal controls (p = 0.018). The AUC-ROC was 0.715 (p = 0.012). The sensitivity, specificity and accuracy rates of 65.4%, 100% and 73.1%, respectively, were observed. The levels of miR-200c in the blood above the cutoff defined by the ROC curve was found in 17.6% of stage I-II GC patients, 20.6% of stage III patients and 67.7% of stage IV patients (p < 0.001). The miR-200c expression levels were not associated with clinical or pathological characteristics or recent surgical procedures. There was a correlation (p = 0.016) with the number of lymph node metastases and the increased expression levels of miR-200c in blood were significantly associated with a poor OS (median OS, 9 vs 24 months; p = 0.016) and PFS (median PFS, 4 vs 11 months; p = 0.044). Multivariate analyses confirmed that the upregulation of miR-200c in the blood was associated with OS (HR = 2.24; p = 0.028) and PFS (HR = 2.27; p = 0.028), independent of clinical covariates.
Conclusions. These data suggest that increased miR-200c levels are detected in the blood of gastric cancer patients. MiR-200c has the potential to be a predictor of progression and survival.Instituto de Salud Carlos III; PI061541Xunta de Galicia; PS08/7
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
The catalog-to-cosmology framework for weak lensing and galaxy clustering for LSST
We present TXPipe, a modular, automated and reproducible pipeline for
ingesting catalog data and performing all the calculations required to obtain
quality-assured two-point measurements of lensing and clustering, and their
covariances, with the metadata necessary for parameter estimation. The pipeline
is developed within the Rubin Observatory Legacy Survey of Space and Time
(LSST) Dark Energy Science Collaboration (DESC), and designed for cosmology
analyses using LSST data. In this paper, we present the pipeline for the
so-called 3x2pt analysis -- a combination of three two-point functions that
measure the auto- and cross-correlation between galaxy density and shapes. We
perform the analysis both in real and harmonic space using TXPipe and other
LSST-DESC tools. We validate the pipeline using Gaussian simulations and show
that it accurately measures data vectors and recovers the input cosmology to
the accuracy level required for the first year of LSST data under this
simplified scenario. We also apply the pipeline to a realistic mock galaxy
sample extracted from the CosmoDC2 simulation suite (Korytov et al. 2019).
TXPipe establishes a baseline framework that can be built upon as the LSST
survey proceeds. Furthermore, the pipeline is designed to be easily extended to
science probes beyond the 3x2pt analysis.Comment: 20+11 pages, 10+11 figures. Version accepted in The Open Journal of
Astrophysic
Leukocyte Overexpression of Intracellular NAMPT Attenuates Atherosclerosis by Regulating PPAR gamma-Dependent Monocyte Differentiation and Function
Objective-Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) mediates inflammatory and potentially proatherogenic effects, whereas the role of intracellular NAMPT (iNAMPT), the rate limiting enzyme in the salvage pathway of nicotinamide adenine dinucleotide (NAD)(+) generation, in atherogenesis is largely unknown. Here we investigated the effects of iNAMPT overexpression in leukocytes on inflammation and atherosclerosis. Approach and Results-Low-density lipoprotein receptor-deficient mice with hematopoietic overexpression of human iNAMPT (iNAMPT(hi)), on a western type diet, showed attenuated plaque burden with features of lesion stabilization. This anti-atherogenic effect was caused by improved resistance of macrophages to apoptosis by attenuated chemokine (C-C motif) receptor 2-dependent monocyte chemotaxis and by skewing macrophage polarization toward an anti-inflammatory M2 phenotype. The iNAMPT(hi) phenotype was almost fully reversed by treatment with the NAMPT inhibitor FK866, indicating that iNAMPT catalytic activity is instrumental in the atheroprotection. Importantly, iNAMPT overexpression did not induce any increase in eNAMPT, and eNAMPT had no effect on chemokine (C-C motif) receptor 2 expression and promoted an inflammatory M1 phenotype in macrophages. The iNAMPT-mediated effects at least partly involved sirtuin 1-dependent molecular crosstalk of NAMPT and peroxisome proliferator-activated receptor.. Finally, iNAMPT and peroxisome proliferator-activated receptor. showed a strong correlation in human atherosclerotic, but not healthy arteries, hinting to a relevance of iNAMPT/peroxisome proliferator-activated receptor. pathway also in human carotid atherosclerosis. Conclusions-This study highlights the functional dichotomy of intracellular versus extracellular NAMPT, and unveils a critical role for the iNAMPT-peroxisome proliferator-activated receptor. axis in atherosclerosis
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
Journa
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