274 research outputs found

    Reliability of Early Fetal Echocardiography for Congenital Heart Disease Detection: A Preliminary Experience and Outcome Analysis of 102 Fetuses to Demonstrate the Value of a Clinical Flow-Chart Designed for At-Risk Pregnancy Management

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    Early fetal echocardiography (EFEC) is a fetal cardiac ultrasound analysis performed between the 12th and 16th week of pregnancy (compared with the usual 18-22 weeks). In the last 10 years, the introduction of “aneuploidy sonographic markers” in screening for cardiac defects has led to a shift from late second to end of the first trimester or beginning of the second trimester of pregnancy for specialist fetal echocardiography. In this prospective study, early obstetric screening was performed between January 2014 and October 2015, using “aneuploidy sonographic markers” following SIEOG Guidelines 2014. These parameters were then collected and strategically combined in an evaluation score to select the group of pregnancies for performing EFEC, in accordance with the American Society of Echocardiography guidelines for fetal Echocardiography. All second-level examinations were performed transabdominally using a 3D convex volumetric probe with frequency range of 4-8 MHz (Accuvix – Samsung). The outcome data included transabdominal fetal echocardiography from 18 weeks to term and after birth. Overall, 99 pregnant women in the first trimester underwent EFEC (95 singleton and 4 twin pregnancies). Specifically, 30 fetuses were evaluated for extra-cardiac anomalies evidenced by obstetric screening (30%), 25 for family history of congenital heart diseases (25%), 8 for family history of genetic-linked diseases (8%), 4 for heart diseases suspected by obstetric screening (4%) and 19 by normal screening (19%). Was detected 11 (10.7%) CHD, when EFEC detected CHD, were compared to those performed later in pregnancy (18 weeks GA-term), a high degree of diagnosis correspondence was evidenced. The higher sensitivity value of EFEC vs late-FE, in comparison with the post-natal value, coupled with the high EFEC specificity shown vs both the end points, enabled us to consider it as a really reliable diagnostic technology, at least in perienced hands. The introduction of a key combination of the more sensitive obstetric and cardiologic variables should facilitate the formulation of a possible flow-chart as a guide for CHD at-risk pregnancies

    Evidenze scientifiche ed insegnamento della lettura. Perché una alfabetizzazione fono-sillabica strutturata è necessaria per tutti i bambini

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    Nonostante la ricerca abbia acquisito esaustive evidenze sull’apprendimento della lettura e scrittura dimostrando la necessità che il bambino acquisisca il principio alfabetico di conversione grafema- fonema in modo progressivo e sistematico, la maggior parte dei testi in adozione che vengono presentati agli insegnanti disconoscono o relegano in secondo piano tale riferimento e prediligono nuove forme di globalismo esteriore e dispersivo. In questo lavoro si sperimenta un programma (ALFABETO 140), elaborato secondo un approccio fono-sillabico, in coerenza con le evidenze acquisite e con i criteri dell’alfabetizzazione strutturata. La sperimentazione condotta a livello nazionale mostra come un programma del genere consenta ai bambini del Gruppo Sperimentale (GS) di ottenere risultati significativamente più alti di quelli del Gruppo di controllo (GC), una significativa riduzione della percentuale dei soggetti a rischio di dislessia ed un ottimo apprezzamento da parte degli insegnanti che lo hanno applicato. Il lavoro si conclude sottolineando la necessità che in tutte le scuole si applichino programmi di questo tipo necessari per tutti i bambini e che anche a livello istituzionale si intervenga per risolvere l’ambiguità esistente nelle indicazioni ministeriali che, pur segnalando l’opportunità di metodi fono- sillabici per soggetti a rischio di DSA, lasciano invece libertà per gli altri soggetti

    Pancreatic cancer molecular classifications: From bulk genomics to single cell analysis

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    Pancreatic cancer represents one of the most lethal disease worldwide but still orphan of a molecularly driven therapeutic approach, although many genomic and transcriptomic classifications have been proposed over the years. Clinical heterogeneity is a hallmark of this disease, as different patients show different responses to the same therapeutic regimens. However, genomic analyses revealed quite a homogeneous disease picture, with very common mutations in four genes only (KRAS, TP53, CDKN2A, and SMAD4) and a long tail of other mutated genes, with doubtful pathogenic meaning. Even bulk transcriptomic classifications could not resolve this great heterogeneity, as many informations related to small cell populations within cancer tissue could be lost. At the same time, single cell analysis has emerged as a powerful tool to dissect intratumoral heterogeneity like never before, with possibility of generating a new disease taxonomy at unprecedented molecular resolution. In this review, we summarize the most relevant genomic, bulk and single-cell transcriptomic classifications of pancreatic cancer, and try to understand how novel technologies, like single cell analysis, could lead to novel therapeutic strategies for this highly lethal disease

    Optical tomography of Fock state superpositions

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    We consider optical tomography of photon Fock state superpositions in connection with recent experimental achievements. The emphasis is put on the fact that it suffices to represent the measured tomogram as a main result of the experiment. We suggest a test for checking the correctness of experimental data. Explicit expressions for optical tomograms of Fock state superpositions are given in terms of Hermite polynomials. Particular cases of vacuum and low photon-number state superposition are considered as well as influence of thermal noise on state purity is studied.Comment: 5 pages, 2 figure

    Pseudo-Unitary Operators and Pseudo-Unitary Quantum Dynamics

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    We consider pseudo-unitary quantum systems and discuss various properties of pseudo-unitary operators. In particular we prove a characterization theorem for block-diagonalizable pseudo-unitary operators with finite-dimensional diagonal blocks. Furthermore, we show that every pseudo-unitary matrix is the exponential of i=1i=\sqrt{-1} times a pseudo-Hermitian matrix, and determine the structure of the Lie groups consisting of pseudo-unitary matrices. In particular, we present a thorough treatment of 2×22\times 2 pseudo-unitary matrices and discuss an example of a quantum system with a 2×22\times 2 pseudo-unitary dynamical group. As other applications of our general results we give a proof of the spectral theorem for symplectic transformations of classical mechanics, demonstrate the coincidence of the symplectic group Sp(2n)Sp(2n) with the real subgroup of a matrix group that is isomorphic to the pseudo-unitary group U(n,n), and elaborate on an approach to second quantization that makes use of the underlying pseudo-unitary dynamical groups.Comment: Revised and expanded version, includes an application to symplectic transformations and groups, accepted for publication in J. Math. Phy

    Infrared conductivity of a one-dimensional charge-ordered state: quantum lattice effects

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    The optical properties of the charge-ordering (COCO) phase of the one-dimensional (1D) half-filled spinless Holstein model are derived at zero temperature within a well-known variational approach improved including second-order lattice fluctuations. Within the COCO phase, the static lattice distortions give rise to the optical interband gap, that broadens as the strength of the electron-phonon (elphel-ph) interaction increases. The lattice fluctuation effects induce a long subgap tail in the infrared conductivity and a wide band above the gap energy. The first term is due to the multi-phonon emission by the charge carriers, the second to the interband transitions accompanied by the multi-phonon scattering. The results show a good agreement with experimental spectra.Comment: 5 figure

    Polaron and bipolaron formation in the Hubbard-Holstein model: role of next-nearest neighbor electron hopping

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    The influence of next-nearest neighbor electron hopping, tt^{\prime}, on the polaron and bipolaron formation in a square Hubbard-Holstein model is investigated within a variational approach. The results for electron-phonon and electron-electron correlation functions show that a negative value of tt^{\prime} induces a strong anisotropy in the lattice distortions favoring the formation of nearest neighbor intersite bipolaron. The role of tt^{\prime}, electron-phonon and electron-electron interactions is briefly discussed in view of the formation of charged striped domains.Comment: 4 figure

    Modelling of strain effects in manganite films

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    Thickness dependence and strain effects in films of La1xAxMnO3La_{1-x}A_xMnO_3 perovskites are analyzed in the colossal magnetoresistance regime. The calculations are based on a generalization of a variational approach previously proposed for the study of manganite bulk. It is found that a reduction in the thickness of the film causes a decrease of critical temperature and magnetization, and an increase of resistivity at low temperatures. The strain is introduced through the modifications of in-plane and out-of-plane electron hopping amplitudes due to substrate-induced distortions of the film unit cell. The strain effects on the transition temperature and transport properties are in good agreement with experimental data only if the dependence of the hopping matrix elements on the MnOMnMn-O-Mn bond angle is properly taken into account. Finally variations of the electron-phonon coupling linked to the presence of strain turn out important in influencing the balance of coexisting phases in the filmComment: 7 figures. To be published on Physical Review
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