Pump-and-probe optical transmission phase shift as a quantitative probe of the Bogoliubov dispersion relation in a nonlinear channel waveguide

We theoretically investigate the dispersion relation of small-amplitude optical waves superimposing upon a beam of polarized monochromatic light propagating along a single-mode channel waveguide characterized by an instantaneous and spatially local Kerr nonlinearity. These small luminous fluctuations propagate along the waveguide as Bogoliubov elementary excitations on top of a one-dimensional dilute Bose quantum fluid evolve in time. They consequently display a strongly renormalized dispersion law, of Bogoliubov type. Analytical and numerical results are found in both the absence and the presence of one- and two-photon losses. Silicon and silicon-nitride waveguides are used as examples. We finally propose an experiment to measure this Bogoliubov dispersion relation, based on a stimulated four-wave mixing and interference spectroscopy techniques.Comment: 17 pages, 7 figure

Factors affecting recurrence risk in her2 positive dcis

n/

Monte-Carlo simulations of the recombination dynamics in porous silicon

A simple lattice model describing the recombination dynamics in visible light emitting porous Silicon is presented. In the model, each occupied lattice site represents a Si crystal of nanometer size. The disordered structure of porous Silicon is modeled by modified random percolation networks in two and three dimensions. Both correlated (excitons) and uncorrelated electron-hole pairs have been studied. Radiative and non-radiative processes as well as hopping between nearest neighbor occupied sites are taken into account. By means of extensive Monte-Carlo simulations, we show that the recombination dynamics in porous Silicon is due to a dispersive diffusion of excitons in a disordered arrangement of interconnected Si quantum dots. The simulated luminescence decay for the excitons shows a stretched exponential lineshape while for uncorrelated electron-hole pairs a power law decay is suggested. Our results successfully account for the recombination dynamics recently observed in the experiments. The present model is a prototype for a larger class of models describing diffusion of particles in a complex disordered system.Comment: 33 pages, RevTeX, 19 figures available on request to [email protected]

Dynamical Characterization of Galaxies at z~4-6 via Tilted Ring Fitting to ALMA [CII] Observations

Until recently, determining the rotational properties of galaxies in the early universe (z>4, Universe age <1.5Gyr) was impractical, with the exception of a few strongly lensed systems. Combining the high resolution and sensitivity of ALMA at (sub-) millimeter wavelengths with the typically high strength of the [CII] 158um emission line from galaxies and long-developed dynamical modeling tools raises the possibility of characterizing the gas dynamics in both extreme starburst galaxies and normal star forming disk galaxies at z~4-7. Using a procedure centered around GIPSY's ROTCUR task, we have fit tilted ring models to some of the best available ALMA [CII] data of a small set of galaxies: the MS galaxies HZ9 & HZ10, the Damped Lyman-alpha Absorber (DLA) host galaxy ALMA J0817+1351, the submm galaxies AzTEC/C159 and COSMOS J1000+0234, and the quasar host galaxy ULAS J1319+0950. This procedure directly derives rotation curves and dynamical masses as functions of radius for each object. In one case, we present evidence for a dark matter halo of O(10^11) solar masses. We present an analysis of the possible velocity dispersions of AzTEC/C159 and ULAS J1319+0950 based on matching simulated observations to the integrated [CII] line profiles. Finally, we test the effects of observation resolution and sensitivity on our results. While the conclusions remain limited at the resolution and signal-to-noise ratios of these observations, the results demonstrate the viability of the modeling tools at high redshift, and the exciting potential for detailed dynamical analysis of the earliest galaxies, as ALMA achieves full observational capabilities.Comment: 20 pages, 6 figures, Accepted for publication in Ap

Graded-size Si quantum dot ensembles for efficient light-emitting diodes

n/

Single-particle states in spherical Si/SiO2_2 quantum dots

We calculate ground and excited electron and hole levels in spherical Si quantum dots inside SiO$_2$ in a multiband effective mass approximation. Luttinger Hamiltonian is used for holes and the strong anisotropy of the conduction electron effective mass in Si is taken into account. As boundary conditions for electron and hole wave functions we use continuity of the wave functions and the velocity density at the boundary of the quantum dots.Comment: 8 pages, 5 figure

Iron deficiency from the standpoint of cardiac rehabilitation : Novel therapeutic opportunities

Anemia is one of the most frequent comorbidities found in patients with coronary artery disease and chronic heart failure (CHF) who are being followed in cardiac rehabilitation facilities. The more frequent type of anemia is that caused by iron deficiency (IDA, iron-deficiency anemia): this review summarizes the state of the art of this topic. First of all, the mechanisms of IDA will be analyzed. Subsequently, a description of the main conditions where IDA can unfavorably affect the clinical course, and of its more frequent complications, will be presented (percutaneous interventions, heart surgery, CHF). Special attention will be paid in the description of anemia in the setting of CHF. To this regard, in recent years a relevant amount of research has been carried out, to determine whether treating anemia (either by directly stimulating erythropoiesis or by correcting iron deficiency by oral or intravenous route) is of any clinical and prognostic relevance in patients with CHF. The results of this research will therefore be summarized and critically discussed. Finally, we will outline the n-commer promising role of cardiac rehabilitation facilities and of its network of experts in the diagnosis, prognostic stratification and treatment of anemia and iron deficiency. o

Delayed Effect of Dendritic Cells Vaccination on Survival in Glioblastoma: A Systematic Review and Meta‐Analysis

Background: Dendritic cell vaccination (DCV) strategies, thanks to a complex immune response, may flare tumor regression and improve patients’ long‐term survival. This meta‐analysis aims to assess the efficacy of DCV for newly diagnosed glioblastoma patients in clinical trials. Meth-ods: The study databases, including PubMed, Web of Knowledge, Google Scholar, Scopus, and Cochrane, were searched by two blinded investigators considering eligible studies based on the following keywords: “glioblastoma multiforme”, “dendritic cell”, “vaccination”, “immunother-apy”, “immune system”, “immune response”, “chemotherapy”, “recurrence”, and “te-mozolomide”. Among the 157 screened, only 15 articles were eligible for the final analysis. Results: Regimens including DCV showed no effect on 6‐month progression‐free survival (PFS, HR = 1.385, 95% CI: 0.822–2.335, p = 0.673) or on 6‐month overall survival (OS, HR = 1.408, 95% CI: 0.882–2.248, p = 0.754). In contrast, DCV led to significantly longer 1‐year OS (HR = 1.936, 95% CI: 1.396–2.85, p = 0.001) and longer 2‐year OS (HR = 3.670, 95% CI: 2.291–5.879, p = 0.001) versus control groups. Hence, introducing DCV could lead to increased 1 and 2‐year survival of patients by 1.9 and 3.6 times, respectively. Conclusion: Antitumor regimens including DCV can effectively improve mid-term survival in patients suffering glioblastoma multiforme (GBM), but its impact emerges only after one year from vaccination. These data indicate the need for more time to achieve an anti‐GBM immune response and suggest additional therapeutics, such as checkpoint inhibitors, to empower an earlier DCV action in patients affected by a very poor prognosis

A light on the dark side: In vivo endoscopic anatomy of the posterior third ventricle and its variations in hydrocephalus

Objective: Despite the technological advancements of neurosurgery, the posterior part of the third ventricle has always been the "dark side"of the ventricle. However, flexible endoscopy offers the opportunity for a direct, in vivo inspection and detailed description of the posterior third ventricle in physiological and pathological conditions. The purposes of this study were to describe the posterior wall of the third ventricle, detailing its normal anatomy and surgical landmarks, and to assess the effect of chronic hydrocephalus on the anatomy of this hidden region. Methods: The authors reviewed the video recordings of 59 in vivo endoscopic explorations of the posterior third ventricle to describe every identifiable anatomical landmark. Patients were divided into 2 groups based on the absence or presence of a chronic dilation of the third ventricle. The first group provided the basis for the description of normal anatomy. Results: The following anatomical structures were identified in all cases: adytum of the cerebral aqueduct, posterior commissure, pineal recess, habenular commissure, and suprapineal recess. Comparing the 2 groups of patients, the authors were able to detect significant variations in the shape of the adytum of the cerebral aqueduct and in the thickness of the habenular and posterior commissures. Exploration with sodium fluorescein excluded the presence of any fluorescent area in the posterior third ventricle, other than the subependymal vascular network. Conclusions: The use of a flexible scope allows the complete inspection of the posterior third ventricle. The anatomical variations caused by chronic hydrocephalus might be clinically relevant, in light of the commissure functions