442 research outputs found

    Definition of out-of-plane fragility curves for masonry infills subject to combined in-plane and out-of-plane damage

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    The paper presents the outcomes of a probabilistic assessment framework aimed at defining out-of-plane fragility curves of unreinforced masonry infills walls which have been subjected (or not) prior in-plane damage. A recently developed in-plane (IP)/out-of-plane (OOP) four-strut macro-element model is used to model masonry infills within frames. Out-of-plane incremental dynamic analyses are performed, for a reference infilled frame, based on a suite of 26 ground motion record selection. Peak ground acceleration (PGA) and OOP relative displacement of the midspan node of the infill, are used as intensity measure and damage measure. The outcomes show fragility curves representing the probability of exceeding out-of-plane collapse at a given earthquake intensity as a function of a different combination of geometrical and mechanical parameters, in-plane damage level and supporting conditions. Results are finally summarized by curves relating in-plane interstorey drifts and out-of-plane average collapse PG

    Carrier-envelope shearing and isolated attosecond pulse generation

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    Conical Bessel-like pulses allow control of the propagation velocity of the main intensity peak.With few-cycle pulses, this leads to a controllable shearing effect with respect to the carrier-phase oscillation and a consequent variation of the instantaneous intensity during propagation. Numerical simulations highlight how this intensity modulation directly controls the atomic dipole phase in the process of high-order harmonic generation and isolates either the long or the short electron-trajectory contributions. We identify a propagation regime in which the harmonic field takes the form of an isolated pulse of 300 as duratio

    Characterization of charge sharing and fluorescence effects by multiple counts analysis in a Pixie-II based detection system

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    In CdTe X-ray photon counting detectors (PCD) featuring small pixel sizes (<100μm), charge-sharing and fluorescences emitted by Cd and Te are responsible for multiple counts from a single interacting photon. These effects can impair the imaging and spectroscopic performance of PCDs. Multiple counts can be partially or totally discriminated by properly setting the energy threshold implemented by the PCD system. Using monochromatic radiation and the Pixirad-1/Pixie-II CdTe PCD, this work characterizes and quantifies clusters of multiple counts as a function of energy and threshold

    Use of Green Sulla Forage for Feeding. 1. Effects on Lamb Growth and Gastrointestinal Nematode Parasite Infestation

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    Recent studies have shown that some forage legumes containing condensed tannins (CT), such as sulla (Hedysarum coronarium L.), can reduce the gastrointestinal nematode burden in sheep (Niezen et al., 1998) and increase post-ruminal protein availability (Waghorn et al., 1994). This study aimed to evaluate the anthelmintic and nutritional properties of sulla forage in relation to its CT content. Thus, the growth performance and the level of nematode infestation of lambs fed sulla were compared with those of lambs fed ryegrass (Lolium multiflorum Lam. subsp. wersterwoldicum), lacking in CT

    A degrading bouc-wen data-driven model for the cyclic behavior of masonry infilled RC frames

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    Mechanics-based macro-models are often used to simulate the cyclic response of infilled reinforced concrete (RC) frames. However, these approaches are affected by uncertainties regarding damage and failure mechanisms. Therefore, this contribution proposes a new smooth data-driven model for the hysteresis of infilled RC frames. The infill panel is modeled through a damage-based Bouc-Wen element, which accounts for both pinching and deterioration of the mechanical characteristics. The parameters of the model are calibrated from an experimental data set of cyclic responses of RC infilled frames. Analytical correlations between parameters and geometric and mechanical characteristics of the infilled frame are derived. Blind validation tests are carried out in order to demonstrate the effectiveness of the proposed model

    DISMICROBISM IN INFLAMMATORY BOWEL DISESE AND COLORECTAL CANCER: CHANGES IN RESPONSE OF COLOCYTES

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    Patients with inflammatory bowel disease (IBD) have an increased risk of 10%-15% developing colorectal cancer (CRC) that is a common disease of high economic costs in developed countries. the CRC has been increasing in recent years and its mortality rates are very high. Multiple biological and biochemical factors are responsible for the onset nad progression of this pathology. moreover, it appears absolutely necessary to investigate the environmental factors favoring the onset of CRC and the production of colonic healt. the gut microflora, or microbiota, has an extensive diversity both quantitatively and qualitatively. in utero, the intestine of the mammalian fetus is sterile. Al birth, the intestinal microbiota in acquired by ingestion maternal anal or vaginal organisms, ultimately developing into a stable community, with marked variations in microbial composition between individuals. the development of IBD is often associated with qualitative and quantitative disorders of the intestinal microbial flora (dysbiosis). the healthy human gut arbours about 10 different bacterial species distributed in colony forming units which colonize the gastrointestinal tract. The intestinal microbiota plays a fundamental role in helath and the progeression of diseases such as IBD and CRC. in Healthy subjects, the main control of intestinal bacterial colonization occurs through gastric acidity but other factors such as endoluminal temperature, competition between different bacterial strains, peristalsis and drugs can influence the intestinal microenvironment. the microbiota exerts diverse physiological functions to include; growth inhibition of pathogenic microrganisms, synthesis of compounds useful for the trophysm of colonic mucosa, regulation of the intestinal lymphoid tissue and synthesis of amino acids. furthermopre, mucus seems to play an important role in protecting the intestinal mucosa and maintaining its integrity. changes in the microbiota composition are mainly influenced by diet and age, as well as genetic factors. Increasing evidence indicates that dysbiosis favors the production of genotoxins and metabolities associated with carcinogeneasis and induces dysregulation of the immune response wich promotes and sustains inflammation in IBD leading to carcinogenesis. a disequilibrium in gut microflora composition leads to the specific activation of gut associated lymphoid tissue. the associated chronic inflammatory process associated increases the risk of developing CRC. Ulcerative colitis and Crohn's diasease are the two major IBDs characterized by an early onset and extraintestinal manifestations, such as rheumatoid arthtritis. the pathogenesis of both diseases is complex and not yet fully known. however, it is widely accepted that an inappropriate immune response to microbial flora can play a pivotal role in IBD pathogenesis

    EFFICACY OF ARGENTUM-QUARTZ SOLUTION IN THE TREATMENT OF PERIANAL FISTULAS: A PRELIMINARY STUDY

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    Objective: Nowadays, an optional and effective medical surgery remains the gold standard for perianal fistulas. Hereby we reported preliminary rsults in favor of using Argentum-Quartz solution for both primary and recurrent perianal fisrtulas. Methods: Three patients with intersphimncter and extrasphinteric fistulas were enrolled. Argentum-Quartz solution was administrated twice a week for sa period of 4 weeks, followed by a pause of 8 days and then another 4 weeks of treatment, totally 16 administrations. After treatment, all patients were monitored for 4-months follow-up. Results: Complete closures of 2 extrasphinteric fistulas and a partial closure with absence of inflammation and superative phenomena in the intraspinteric fistula were both manifested. Conclusions: Selective treatment of perianal fistulas with argentum-quartz solution is safe and effective. and may represent a reliable alternative
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