248 research outputs found

    Laboratory and on-site tests for rapid runway repair

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    The attention to rapid pavement repair has grown fast in recent decades: this topic is strategic for the airport management process for civil purposes and peacekeeping missions. This work presents the results of laboratory and on-site tests for rapid runway repair, in order to analyse and compare technical and mechanical performances of 12 different materials currently used in airport. The study focuses on site repairs, a technique adopted most frequently than repairs with modular elements. After describing mechanical and physical properties of the examined materials (2 bituminous emulsions, 5 cement mortars, 4 cold bituminous mixtures and 1 expanding resin), the study presents the results of carried out mechanical tests. The results demonstrate that the best performing material is a one-component fast setting and hardening cement mortar with graded aggregates. This material allows the runway reopening 6 h after the work. A cold bituminous mixture (bicomponent premixed cold asphalt with water as catalyst) and the ordinary cement concrete allow the reopening to traffic after 18 h, but both ensure a lower service life (1000 coverages) than the cement mortar (10,000 coverages). The obtained results include important information both laboratory level and field, and they could be used by airport management bodies and road agencies when scheduling and evaluating pavement repairs

    Simple and fast orotracheal intubation procedure in rat

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    Introduction: Endotracheal intubation in the rat is difficult because of extremely small size of anatomical structures (oral cavity, epiglottis and vocal cords), small inlet for an endotracheal tube and the lack of proper techniacal instruments. Matherial and Methods: In this study we used seventy rats weighthing 400-500 g. The equipment needed for intubation was an operating table, a longish of cotton, a cotton tip, orotracheal tube, neonatal laryngoscope KTR4, small animal ventilator, and isoflurane for inhalation anaesthesia. Premedication was carried out by medetomidine hydrochloride 1 mg/mL; then, thanks to a closed glass chamber, a mixture of oxygen and isoflurane was administered. By means of neonatal laryngoscope the orotracheal tube was advanced into the oral cavity untile the wire guide was visualized trough the vocal cords; then it was passed through them. The tube was introduced directly into into the larynx over the wire guide; successively, the guide was removed and the tube placed into the trachea. Breathing was confirmed using a glove, cut at the end of a finger, simulating a small ballon. Conclusions: We believe that our procedure is easier and faster than those previously reported in scientific literature. (www.actabiomedica.it

    Per una storia dell’antirazzismo nell’Italia repubblicana: problemi e ipotesi di ricerca

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    OBTAINING MESENCHYMAL STEM CELLS FROM ADIPOSE TISSUE OR MURIN ORIGIN: EXPERIMENTAL STUDY.

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    The aim of this study was to isolate and characterize rat adipose Derived Mesenchymal Stem Cells (AD-MSCs) in order to evaluate their proliferative potential and their ability to different cell types. AD-MSCs and Derived Mesenchymal Stem Cells (BM-MSCs) have the same characteristic in terms of plasticity. The advantage of adipose tissue is that it is an easier accessible source and it offers a large amount of MSCs by less invasive surgical tecniques. MSCs were obtained from subcutaneous adipose tissue of Wistar rats. first of all microbiological controls were made to exclude the presence of bacteria of fungi in then tissue. Adipose tissue was mechanically and enzimatically fragmented and stromal cell fraction was seeded in adherent culture flasks in DMEM 20% FBS. After 48 h the medium was replaced. Cells were characterized by evaluating:1)their ability tho adhere to the plastic; 2) the clonogenic potential by Colony Forming Unit (CFU) assay, 3) their ability to differentiate in 3 mesodermal lineages (adipocytes, osteocytes and chondrocytes). AD-MSCs are able to differentiate in adipocytes, osteocytes and chondrocytes as confirmed by oil red'O staining, von Kossa staining and histological analuysis respectively. This first characterization is essential for the second part of our study in which we are planning to use AD-MSCs in vivo to restore renal function after an induced ischemic damage in experimental animals
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