122 research outputs found

    Acute occlusion of descending thoracic aorta

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    Acute aortic occlusion is a rare but potentially devastating clinical event, which requires a prompt diagnosis and emergency treatment. Only 5 cases of native thoracic aorta acute occlusion have so far been reported with different pathologic causes. The clinical features depend on the level of occlusion. Sometimes the diagnosis could be misinterpreted as a stroke or other diseases of the central nervous system. This could lead to a delay in the diagnosis and revascularization procedure, followed by a morbidity or mortality increase. Open surgery has been considered the first-line approach. This study is of a female patient suffering from acute descending thoracic aorta occlusion undergoing, for the first time to our knowledge, endovascular surgical treatment

    Generation of non-synchronous accelerograms for evaluate the seismic bridge response, including local site amplification.

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    Non-synchronous seismic actions particularly affect the behaviour of infrastructures with significant longitudinal extension, as bridges, interacting with the soil at surface or below ground level. Some authors state that non synchronism may increase by a large amount the structural response. Several acceleration records relative to different points of the ground with different soil profiles at distances meaningful for bridge analyses, are not available in data banks. The objective of this work is the generation of arrays of asynchronous signals at different points in space, starting from natural accelerograms related to a given seismic event, to increase the number of the available data. The computer code GAS has been modified to use natural accelerograms. The procedure has been applied to a real case, L’Aquila main-shock, for which records in different points of the free field are known

    Seismic Response of Viaducts Accounting for Soil-Structure Interaction

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    A research was recently granted by the Italian Government to develop a comprehensive procedure to account for spatial variability of ground motion as well as soil-structure interaction in assessing the behaviour of bridges. This paper reports on the work-package relevant to the effects of soil-structure interaction. In the first section, a methodology to include the effects of soil-structure interaction in the nonlinear response of bridges is presented. Kinematic interaction analysis is performed in the frequency domain by means of a procedure accounting for radiation damping, soil-pile and pile-to-pile interaction; the non-linear inertial interaction analysis is performed in the time domain by using a finite element model of the superstructure. Suitable lumped parameter models are implemented to reproduce the frequency-dependent compliance of soil-foundation systems. In the second section, some results of nonlinear dynamic analyses performed on some bridges designed on soft soils by means of a direct displacement approach are presented

    Galaxy Light profile neural Networks (GaLNets). II. Bulge-Disc decomposition in optical space-based observations

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    Bulge-disk (B-D) decomposition is an effective diagnostic to characterize the galaxy morphology and understand its evolution across time. So far, high-quality data have allowed detailed B-D decomposition to redshift below 0.5, with limited excursions over small volumes at higher redshifts. Next-generation large sky space surveys in optical, e.g. from the China Space Station Telescope (CSST), and near-infrared, e.g. from the space EUCLID mission, will produce a gigantic leap in these studies as they will provide deep, high-quality photometric images over more than 15000 deg2 of the sky, including billions of galaxies. Here, we extend the use of the Galaxy Light profile neural Network (GaLNet) to predict 2-S\'ersic model parameters, specifically from CSST data. We simulate point-spread function (PSF) convolved galaxies, with realistic B-D parameter distributions, on CSST mock observations to train the new GaLNet and predict the structural parameters (e.g. magnitude, effective radius, Sersic index, axis ratio, etc.) of both bulge and disk components. We find that the GaLNet can achieve very good accuracy for most of the B-D parameters down to an rr-band magnitude of 23.5 and redshift \sim1. The best accuracy is obtained for magnitudes, implying accurate bulge-to-total (B/T) estimates. To further forecast the CSST performances, we also discuss the results of the 1-S\'ersic GaLNet and show that CSST half-depth data will allow us to derive accurate 1-component models up to rr\sim24 and redshift z\sim1.7

    The prolyl-isomerase PIN1 is essential for nuclear Lamin-B structure and function and protects heterochromatin under mechanical stress

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    Chromatin organization plays a crucial role in tissue homeostasis. Heterochromatin relaxation and consequent unscheduled mobilization of transposable elements (TEs) are emerging as key contributors of aging and aging-related pathologies, including Alzheimer's disease (AD) and cancer. However, the mechanisms governing heterochromatin maintenance or its relaxation in pathological conditions remain poorly understood. Here we show that PIN1, the only phosphorylation-specific cis/trans prolyl isomerase, whose loss is associated with premature aging and AD, is essential to preserve heterochromatin. We demonstrate that this PIN1 function is conserved from Drosophila to humans and prevents TE mobilization-dependent neurodegeneration and cognitive defects. Mechanistically, PIN1 maintains nuclear type-B Lamin structure and anchoring function for heterochromatin protein 1\u3b1 (HP1\u3b1). This mechanism prevents nuclear envelope alterations and heterochromatin relaxation under mechanical stress, which is a key contributor to aging-related pathologies

    Wnt5a Drives an Invasive Phenotype in Human Glioblastoma Stem-like Cells

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    Brain invasion by glioblastoma determines prognosis, recurrence, and lethality in patients, but no master factor coordinating the invasive properties of glioblastoma has been identified. Here we report evidence favoring such a role for the noncanonical WNT family member Wnt5a. We found the most invasive gliomas to be characterized by Wnt5a overexpression, which correlated with poor prognosis and also discriminated infiltrating mesenchymal glioblastoma from poorly motile proneural and classical glioblastoma. Indeed, Wnt5a overexpression associated with tumor-promoting stem-like characteristics (TPC) in defining the character of highly infiltrating mesenchymal glioblastoma cells (Wnt5aHigh). Inhibiting Wnt5a in mesenchymal glioblastoma TPC suppressed their infiltrating capability. Conversely, enforcing high levels of Wnt5a activated an infiltrative, mesenchymal-like program in classical glioblastoma TPC and Wnt5aLow mesenchymal TPC. In intracranial mouse xenograft models of glioblastoma, inhibiting Wnt5a activity blocked brain invasion and increased host survival. Overall, our results highlight Wnt5a as a master regulator of brain invasion, specifically TPC, and they provide a therapeutic rationale to target it in patients with glioblastoma

    Integration of energy and electron transfer processes in the photosynthetic membrane of Rhodobacter sphaeroides

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    Photosynthesis converts absorbed solar energy to a protonmotive force, which drives ATP synthesis. The membrane network of chlorophyll–protein complexes responsible for light absorption, photochemistry and quinol (QH2) production has been mapped in the purple phototrophic bacterium Rhodobacter (Rba.) sphaeroides using atomic force microscopy (AFM), but the membrane location of the cytochrome bc1 (cytbc1) complexes that oxidise QH2 to quinone (Q) to generate a protonmotive force is unknown. We labelled cytbc1 complexes with gold nanobeads, each attached by a Histidine10 (His10)-tag to the C-terminus of cytc1. Electron microscopy (EM) of negatively stained chromatophore vesicles showed that the majority of the cytbc1 complexes occur as dimers in the membrane. The cytbc1 complexes appeared to be adjacent to reaction centre light-harvesting 1-PufX (RC–LH1–PufX) complexes, consistent with AFM topographs of a gold-labelled membrane. His-tagged cytbc1 complexes were retrieved from chromatophores partially solubilised by detergent; RC–LH1–PufX complexes tended to co-purify with cytbc1 whereas LH2 complexes became detached, consistent with clusters of cytbc1 complexes close to RC–LH1–PufX arrays, but not with a fixed, stoichiometric cytbc1–RC–LH1–PufX supercomplex. This information was combined with a quantitative mass spectrometry (MS) analysis of the RC, cytbc1, ATP synthase, cytaa3 and cytcbb3 membrane protein complexes, to construct an atomic-level model of a chromatophore vesicle comprising 67 LH2 complexes, 11 LH1–RC–PufX dimers & 2 RC–LH1–PufX monomers, 4 cytbc1 dimers and 2 ATP synthases. Simulation of the interconnected energy, electron and proton transfer processes showed a half-maximal ATP turnover rate for a light intensity equivalent to only 1% of bright sunlight. Thus, the photosystem architecture of the chromatophore is optimised for growth at low light intensities

    Tmetoceratidae (Ammonitina) fauna from the Gerecse Mts (Hungary)

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    Abstract Taxonomic and stratigraphic problems of the family Tmetoceratidae and the genera Dumortieria, Catulloceras, Cotteswoldia, Pleydellia and Tmetoceras included in it are briefly discussed. Fifteen species of Tmetoceratidae are described and illustrated from the Upper Toarcian-Aalenian ammonite assemblages of the Gerecse Mts (NE Transdanubian Range, Hungary). The fauna described here is closely allied to the Mediterranean Province of the Mediterranean-Caucasian Realm
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