840 research outputs found

    Cobalt, chromium and molybdenum ions kinetics in the human body: data gained from a total hip replacement with massive third body wear of the head and neuropathy by cobalt intoxication.

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    6openopenPazzaglia, U; Apostoli, P; Congiu, T; Catalani, S; Marchese, M; Zarattini, G.Pazzaglia, Ugo; Apostoli, Pietro; Congiu, T; Catalani, S; Marchese, M; Zarattini, Guid

    Effect of Cold Rolling on Microstructural and Mechanical Properties of a Dual-Phase Steel for Automotive Field

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    A new advanced dual-phase (DP) steel characterized by ferrite and bainite presence in equal fractions has been studied within this paper. The anisotropy change of this steel was assessed as a progressively more severe cold rolling process was introduced. Specifically, tensile tests were used to build a strain-hardening curve, which describes the evolution of this DP steel's mechanical properties as the thinning level increases from 20 to 70% with 10% step increments. As expected, the cold rolling process increases mechanical properties, profoundly altering the material's microstructure, which was assessed in depth using Electron Backscatter Diffraction (EBSD) analysis coupled with the Kernel Average Misorientation (KAM) maps. At the same time, the process strongly modifies the material planar anisotropy. Microstructural and mechanical assessment and the Kocks-Mecking model applied to this steel evidenced that a 50% strain hardening makes the DP steel isotropic. The material retains or resumes anisotropic behavior for a lower or higher degree of deformation. Furthermore, the paper evaluated the forming limit of this DP steel and introduced geometric limitations to testing the thin steel plates' mechanical properties

    The iron-regulated surface determinant B (IsdB) protein from Staphylococcus aureus acts as a receptor for the host protein vitronectin.

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    Staphylococcus aureus is an important bacterial pathogen that can cause a wide spectrum of diseases in humans and other animals. S. aureus expresses a variety of virulence factors that promote infection with this pathogen. These include cell-surface proteins that mediate adherence of the bacterial cells to host extracellular matrix components, such as fibronectin and fibrinogen. Here, using immunoblotting, ELISA, and surface plasmon resonance analysis, we report that the iron-regulated surface determinant B (IsdB) protein, besides being involved in heme transport, plays a novel role as a receptor for the plasma and extracellular matrix protein vitronectin (Vn). Vn-binding activity was expressed by staphylococcal strains grown under iron starvation conditions when Isd proteins are expressed. Recombinant IsdB bound Vn dose dependently and specifically. Both near-iron transporter motifs NEAT1 and NEAT2 of IsdB individually bound Vn in a saturable manner, with KD values in the range of 16-18 nm Binding of Vn to IsdB was specifically blocked by heparin and reduced at high ionic strength. Furthermore, IsdB-expressing bacterial cells bound significantly higher amounts of Vn from human plasma than did an isdB mutant. Adherence to and invasion of epithelial and endothelial cells by IsdB-expressing S. aureus cells was promoted by Vn, and an αvβ3 integrin-blocking mAb or cilengitide inhibited adherence and invasion by staphylococci, suggesting that Vn acts as a bridge between IsdB and host αvβ3 integrin

    Echocardiographic Screening of Anomalous Origin of Coronary Arteries in Athletes with a Focus on High Take-Off

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    Anomalous aortic origin of coronary arteries (AAOCA) represents a rare congenital heart disease. However, this disease is the second most common cause of sudden cardiac death in apparently healthy athletes. The aim of this systematic review is to analyze the feasibility and the detection rate of AAOCA by echocardiography in children and adults. A literature search was performed within the National Library of Medicine using the following keywords: coronary artery origin anomalies and echocardiography; then, the search was redefined by adding the keywords: athletes, children, and high take-off. Nine echocardiographic studies investigating AAOCA and a total of 33,592 children and adults (age range: 12-49 years) were included in this review. Of these, 6599 were athletes (12-49 years). All studies demonstrated a high feasibility and accuracy of echocardiography for the evaluation of coronary arteries origin as well as their proximal tracts. However, some limitations exist: the incidence of AAOCA varied from 0.09% to 0.39% (up to 0.76%) and was lower than described in computed tomography series (0.3-1.8%). Furthermore, echocardiographic views for the evaluation of AAOCA and the definition of minor defects (e.g., high take-off coronary arteries) have not been standardized. An echocardiographic protocol to diagnose the high take-off of coronary arteries is proposed in this article. In conclusion, the screening of AAOCA by echocardiography is feasible and accurate when appropriate examinations are performed; however, specific acoustic windows and definitions of defects other than AAOCA need to be standardized to improve sensitivity and specificity

    Role of chronic exsposure to cigarette smoke on endoglin/CD105 expression in airway epithelium.

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    Dysregulation of airway epithelial cell function related to cigarette smoke exposure plays an important role in the pathophysiology of COPD and is associated to tissue damage and disease severity. CD105 is a component of the receptor complex of TGF-β, a pleiotropic cytokine involved in cellular proliferation, differentiation and migration. CD105 regulates the expression of different components of the extracellular matrix suggesting a role of CD105 in cellular transmigration and remodeling processes. The aim of the present study was to investigate the expression of endoglin/CD105 in airway epithelium of COPD patients and its involvement in tissue remodeling and progression of COPD. We evaluated the immunoreactivity for CD105 expression in bronchial biopsies isolated from COPD patients and healthy controls (HC). The analysis of metaplastic epithelium was performed in bronchial biopsies by Image Analysis software (Leica Quantimet system). Finally, we investigated the expression of CD105 protein receptor in human bronchial epithelial cells (16HBE cells) exposed to 5% Cigarette Smoke Extract (CSE) for 12 days by western blot. We found that the CD105 immunoreactivity was significantly higher in bronchial epithelium of COPD than HC. Morphometric analysis of bioptic samples of COPD showed an increase of the immunoreactivity for CD105 in the area of metaplastic than in not metaplastic epithelium. Long term exposure to CSE significantly up-regulated CD105 expression in 16HBE. Chronic inflammation due to cigarette smoke might play a critic role on the alteration of CD105 protein expression in COPD, promoting tissue remodeling, angiogenesis and dysregulation of physiological reparative mechanisms, leading to squamous metaplasia

    Hemodynamics in healthy and pathological thoracic aorta: integration of in-vivo data in CFD simulations and in in-vitro experiments

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    A comparison between the results of the CFD simulations and the in-vitro experiments carried out on a circulatory mock loop is presented. Both approaches integrate in-vivo measurements obtained from a patient-specific clinical data set. Three thoracic-aorta geometries are analyzed: a healthy aorta, an aneurysmatic aorta, and a coarctated aorta. The healthy geometry is obtained from Magnetic Resonance Imaging (MRI) acquisitions, together with the patient-specific flow-rate waveform, whereas the diseased ones are derived from the former geometry by locally morphing the vessel's wall. The open-source code Simvascular is used for simulations. The in-vitro results are measured in a fully controlled and sensorized circulatory mock loop for 3D-printed aortic models. Differently from in-vivo acquisitions, the experimental set-up eliminates some of the uncontrollable uncertainties that characterize MRI data. Indeed, perfect control of the flow rate and full knowledge of the wall model characteristics (rigid walls in the present case) is allowed in experiments and, thus, clear indications can be obtained to validate and improve the accuracy of numerical models. The numerical and experimental results are in good agreements for the three analyzed geometries and the flow-rate conditions. In-vivo data from the healthy case are in a satisfactory agreement with numerical/in-vitro results, and they can be ascribed to possible differences between MRI and numerical/in-vitro set-ups. The velocity fields obtained through CFD are consistent with the echographic results in in-vitro experiments, showing the same flow patterns in healthy and pathological cases

    Brief communication: Co-seismic displacement on 26 and 30 October 2016 ( M w = 5.9 and 6.5) – earthquakes in central Italy from the analysis of a local GNSS network

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    Abstract. On 24 August 2016 a strong earthquake (Mw = 6.0) affected central Italy and an intense seismic sequence started. Field observations, DInSAR (Differential INterferometry Synthetic-Aperture Radar) analyses and preliminary focal mechanisms, as well as the distribution of aftershocks, suggested the reactivation of the northern sector of the Laga fault, the southern part of which was already rebooted during the 2009 L'Aquila sequence, and of the southern segment of the Mt Vettore fault system (MVFS). Based on this preliminary information and following the stress-triggering concept (Stein, 1999; Steacy et al., 2005), we tentatively identified a potential fault zone that is very vulnerable to future seismic events just north of the earlier epicentral area. Accordingly, we planned a local geodetic network consisting of five new GNSS (Global Navigation Satellite System) stations located a few kilometres away from both sides of the MVFS. This network was devoted to working out, at least partially but in some detail, the possible northward propagation of the crustal network ruptures. The building of the stations and a first set of measurements were carried out during a first campaign (30 September and 2 October 2016). On 26 October 2016, immediately north of the epicentral area of the 24 August event, another earthquake (Mw = 5.9) occurred, followed 4 days later (30 October) by the main shock (Mw = 6.5) of the whole 2016 summer–autumn seismic sequence. Our local geodetic network was fully affected by the new events and therefore we performed a second campaign soon after (11–13 November 2016). In this brief note, we provide the results of our geodetic measurements that registered the co-seismic and immediately post-seismic deformation of the two major October shocks, documenting in some detail the surface deformation close to the fault trace. We also compare our results with the available surface deformation field of the broader area, obtained on the basis of the DInSAR technique, and show an overall good fit

    Brief Communication Co-seismic displacement on October 26 and 30, 2016 (M<sub>w</sub> 5.9 and 6.5) – earthquakes in central Italy from the analysis of discrete GNSS network

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    &lt;p&gt;&lt;strong&gt;Abstract.&lt;/strong&gt; On October 26&lt;sup&gt;th&lt;/sup&gt; 2016, immediately north of the epicentral area affected by the M&lt;sub&gt;w&lt;/sub&gt; 6.0, August 24&lt;sup&gt;th&lt;/sup&gt; earthquake, a strong earthquake (&lt;b&gt;&lt;i&gt;M&lt;/i&gt;&lt;/b&gt;&lt;sub&gt;w&lt;/sub&gt;&amp;#8201;=&amp;#8201;5.9), with a focal mechanism showing W-dipping normal faulting, occurred at the boundary between Marche and Umbria regions (central Apennines, Italy). Four days later (on October 30&lt;sup&gt;th&lt;/sup&gt;), the main-shock (&lt;b&gt;&lt;i&gt;M&lt;/i&gt;&lt;/b&gt;&lt;sub&gt;w&lt;/sub&gt;&amp;#8201;=&amp;#8201;6.5) of the whole seismic sequence occurred in the same area. The central Apennines are characterized by northeast-verging thrust-propagation folds, involving Mesozoic- Tertiary sedimentary successions. During the 2016 sequence, coseismic deformation has been recorded at the rear of the Sibillini Thrust which separates the main mountain chain from the Marche-Abruzzi foothills (Fig. 1). This contractional structure has been partly dissected and/or inverted by NNW-SSE trending Quaternary normal and oblique-slip faults. The major event (October 30) induced extensive geological effects at the surface and structural damages in the broader epicentral area up to a distance of 30&amp;#8201;km. According to the report of the Istituto Nazionale di Geofisica e Vulcanologia (SUMMARY REPORT ON THE 30 OCTOBER, 2016 EARTHQUAKE IN CENTRAL ITALY Mw 6.5, Gruppo di Lavoro INGV sul Terremoto in centro Italia 10 November 2016), the hypocenter of major event was located at 42.8322&amp;#176;&amp;#8201;N, 13.1107&amp;#176;&amp;#8201;E at a depth of 9.2&amp;#8201;km (Figs. 1 and 2). Following the August seismic events, we installed five new geodetic points located on both sides of the principal fracture zone and carried out two campaigns of GNSS measurements, the first one at the end of September (30-09/02-10, 2016), the second one early November (11/13-11, 2016) that covered the period of the October events. &lt;br&gt;&lt;br&gt; In this brief communication, we provide the results of our geodetic campaigns that registered the co- seismic displacement occurred in the period between doy (day of year) 2016/274 and doy 2016/318, therefore documenting the two latter major shocks. We also compare our results with the available surface deformation field of the broader area obtained on the basis of the DInSAR technique and particularly the elaboration realized by CNR-IREA of Sentinel-1 radar imaging of Copernicus European Program of 26/10&amp;#8211;1/11 (&lt;a href=&quot; http://www.irea.cnr.it/index.php?option=com_k2&amp;view=item&amp;id=761:nuovi-risultati-sul-terremoto- del-30-ottobre-2016-ottenuti-dai-radar-dei-satelliti-sentinel-1&quot;target=&quot;_blank&quot;&gt;http://www.irea.cnr.it/index.php?option=com_k2&amp;view=item&amp;id=761:nuovi-risultati-sul-terremoto- del-30-ottobre-2016-ottenuti-dai-radar-dei-satelliti-sentinel-1&lt;/a&gt;). The comparison shows an overall good fit. It&amp;#8217;s worth to note that these earthquakes occurred in a sector of the Central Apennines characterized by high geodetic strain-rates (e.g., D&amp;#8217;Agostino 2014), where several continuous GNSS stations are operating.&lt;/p&gt

    Psychopathological Impact in Patients with History of Rheumatic Fever with or without Sydenham's Chorea: A Multicenter Prospective Study

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    Sydenham's chorea (SC) is a post-streptococcal autoimmune disorder of the central nervous system, and it is a major criterium for the diagnosis of acute rheumatic fever (ARF). SC typically improves in 12-15 weeks, but patients can be affected for years by persistence and recurrencies of both neurological and neuropsychiatric symptoms. We enrolled 48 patients with a previous diagnosis of ARF, with or without SC, in a national multicenter prospective study, to evaluate the presence of neuropsychiatric symptoms several years after SC's onset. Our population was divided in a SC group (n = 21), consisting of patients who had SC, and a nSC group (n = 27), consisting of patients who had ARF without SC. Both groups were evaluated by the administration of 8 different neuropsychiatric tests. The Work and Social Adjustment Scale (WSAS) showed significantly (p = 0.021) higher alterations in the SC group than in the nSC group. Furthermore, 60.4% (n = 29) of the overall population experienced neuropsychiatric symptoms other than choreic movements at diagnosis and this finding was significantly more common (p = 0.00) in SC patients (95.2%) than in nSC patients (33.3%). The other neuropsychiatric tests also produced significant results, indicating that SC can exert a strong psychopathological impact on patients even years after its onset
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