3,630 research outputs found

    Improvement in workability of terminals placed along the inner side of port vertical breakwaters by means of recurved parapet walls

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    The function of main port breakwaters is to protect harbour basins from incoming waves and currents. In the event that a maritime terminal is placed on the inner side of a main breakwater, it is extremely important to limit waves overtopping the structure, because the overtopping flows may be very dangerous for the safety of the operations taking place in the terminal. Very often during storms if the overtopping discharges are severe, the terminal is temporarily closed, reducing its average annual workability accordingly. Wave overtopping is normally limited by using high parapet walls (crownwalls) which are not well considered from an environmental point of view due to their visual impact. A good solution to reduce wave overtopping limiting the increasing of the crownwalls height, is to use recurved parapet walls. The paper presents a new formula for recurved walls which can be used to estimate the overtopping flow rates reduction compared to normal vertical parapets. The formula has been obtained for vertical breakwaters by using numerical computations. The recurved parapet has the shape of a circumference sector, characterized by a radius and an opening angle. The numerical computations were performed applying OpenFOAM® which solves the 3D RANS equations for multiphase flows (air and water). The results show the high hydraulic efficiency of recurved walls in reducing overtopping rates compared to traditional vertical parapets

    Hindcast and forecast of the Parsifal storm

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    On 2 November 1995 a Mistral storm in the Gulf of Lions sank the 16 metre yacht Parsifal claiming six lives out of the nine member crew. We analyse the storm with different meteorological and wave models, verifying the results against the available buoy and satellite measurements. Then we consider the accuracy of the storm forecasts and the information available the days before the accident. The limitations related to the resolution of the meteorological models are explored by hindcasting the storm also with the winds produced by some limited area models. Finally, we discuss the present situation of wind and wave hindcast and forecast in theMediterranean Sea, and the distribution of these results to the public

    Autologous Microfragmented Adipose Tissue Reduces the Catabolic and Fibrosis Response in an in Vitro Model of Tendon Cell Inflammation

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    Background. Mesenchymal stem cells (MSCs) emerged as a promising therapy for tendon pathologies. Microfragmented adipose tissue (\u3bcFAT) represents a convenient autologous product for the application of MSC-based therapies in the clinical setting. In the present study, the ability of \u3bcFAT to counteract inflammatory processes induced by IL-1\u3b2 on human tendon cells (TCs) was evaluated. Methods. Cell viability and proliferation were evaluated after 48 hours of transwell coculture of TCs and autologous \u3bcFAT in the presence or absence of IL-1\u3b2. Gene expression of scleraxis, collagen type I and type III, metalloproteinases-1 and -3, and cyclooxygenase-2 was evaluated by real-time RT-PCR. The content of VEGF, IL-1Ra, TNF\u3b1, and IL-6 was evaluated by ELISA. Results. IL-1\u3b2-treated TCs showed augmented collagen type III, metalloproteases, and cyclooxygenase-2 expression. \u3bcFAT was able to reduce the expression of collagen type III and metalloproteases-1 in a significant manner, and at the same time, it enhanced the production of VEGF, IL-1Ra, and IL-6. Conclusions. In this in vitro model of tendon cell inflammation, the paracrine action of \u3bcFAT, exerted by anti-inflammatory molecules and growth factors, was able to inhibit the expression of fibrosis and catabolic markers. Then, these results suggest that the application of \u3bcFAT may represent an effective conservative or adjuvant therapy for the treatment of tendon disorders

    Evidence-based considerations exploring relations between sars-cov-2 pandemic and air pollution: Involvement of pm2.5-mediated up-regulation of the viral receptor ace-2

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    The COVID-19/SARS-CoV-2 pandemic struck health, social and economic systems worldwide, and represents an open challenge for scientists —coping with the high inter-individual variability of COVID-19, and for policy makers —coping with the responsibility to understand environmental factors affecting its severity across different geographical areas. Air pollution has been warned of as a modifiable factor contributing to differential SARS-CoV-2 spread but the biological mechanisms underlying the phenomenon are still unknown. Air quality and COVID-19 epidemiological data from 110 Italian provinces were studied by correlation analysis, to evaluate the association between particulate matter (PM)2.5 concentrations and incidence, mortality rate and case fatality risk of COVID-19 in the period 20 February–31 March 2020. Bioinformatic analysis of the DNA sequence encoding the SARS-CoV-2 cell receptor angiotensin-converting enzyme 2 (ACE-2) was performed to identify consensus motifs for transcription factors mediating cellular response to pollutant insult. Positive correlations between PM2.5 levels and the incidence (r = 0.67, p < 0.0001), the mortality rate (r = 0.65, p < 0.0001) and the case fatality rate (r = 0.7, p < 0.0001) of COVID-19 were found. The bioinformatic analysis of the ACE-2 gene identified nine putative consensus motifs for the aryl hydrocarbon receptor (AHR). Our results confirm the supposed link between air pollution and the rate and outcome of SARS-CoV-2 infection and support the hypothesis that pollution-induced over-expression of ACE-2 on human airways may favor SARS-CoV-2 infectivity

    High Levels of Circulating Type II Collagen Degradation Marker (CTx-II) Are Associated with Specific VDR Polymorphisms in Patients with Adult Vertebral Osteochondrosis

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    Both vitamin D and collagen have roles in osteocartilaginous homeostasis. We evaluated the association between the circulating 25-hydroxyvitamin D (25(OH)D) type I and II collagen degradation products (CTx-I, and CTx-II), and four vitamin D receptor gene (VDR) polymorphisms, in Italian males affected by low back pain (LBP) due to herniation/discopathy and/or vertebral osteochondrosis. FokI, BsmI, ApaI, and TaqI VDR-polymorphisms were detected through PCR-restriction fragment length polymorphism (RFLP), and circulating 25(OH)D, CTx-I and CTx-II were measured by immunoassays in 79 patients (of which 26 had osteochondrosis) and 79 age-, sex- and body mass index (BMI)-matched healthy controls. Among all 158 subjects, carriers of FF and Ff genotypes showed lower 25(OH)D than ff, which suggested a higher depletion of vitamin D in F allele carriers. Higher CTx-I concentrations were observed in TT versus Tt among controls, and Tt versus tt among LBP cases, which suggested a higher bone-cartilaginous catabolism in subjects bearing the T allele. Higher CTx-II concentrations were observed in patients with osteochondrosis bearing FF, bb, TT, or Aa genotypes in comparison with hernia/discopathy patients and healthy controls. Vertebral osteochondrosis shows peculiar genotypic and biochemical features related to vitamin D and the osteocartilaginous metabolism. Vitamin D has roles in the pathophysiology of osteochondrosis

    Cell-based regenerative joint therapy: a hot topic

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    Chirurgia radicolare: indicazioni e tecnica

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    Osseous resective surgery deals with treatment of roots and multirooted teeth affected by different kinds of disease or lesions, mostly of periodontal nature. It involves techniques which enable the clinicial in preserving the stability by sacrifying only part of the compromised roots. In this study, such surgical procedures will be described in relation to simplified definitions:- root separation and extraction; - root separation; - root amputation. With root amputation it is possibile to leave the overlying reconstruction unaltered or perform a modification of the crown (plasty) in order to realize a coronal anatomy compatible with the direction of occlusal loading. Both root separation and amputation require eventually a prosthesis and prostetic appliances, would have to be prepared for easy cleaning, both for home care standards and for professional maintenance, and for proper distribution of occlusal load. Such treatments seem to be a valid alternative when compared to tooth extraction followed by conventional fixed or removable prosthesis, or implant supported, more complex and expensive. The choice for one or the other solution (conservative or extractive) depends upon the evaluation of all the prognosis factors invloved with both procedures, which are mostly patient’s compliance and the presence of anatomical favorable relationships. Once such information are obtained, after proper clinical and radiological exams, the surgical protocol would have to be followed very stringently: endodontically, operatively, surgically and prosthodontically. Only by following all these steps and the right patient selection good results can be obtained, with a long term prognosis
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