533 research outputs found

    Multicolor fluorescence technique to detect apoptotic cells in advanced coronary atherosclerotic plaques.

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    Apoptosis occurring in atherosclerotic lesions has been suggested to be involved in the evolution and the structural stability of the plaques. It is still a matter of debate whether apoptosis mainly involves vascular smooth muscle cells (vSMCs) in the fibrous tissue or inflammatory (namely foam) cells, thus preferentially affecting the cell-poor lipid core of the atherosclerotic plaques. The aim of the present investigation was to detect the presence of apoptotic cells and to estimate their percentage in a series of atherosclerotic plaques obtained either by autopsy or during surgical atherectomy. Apoptotic cells were identified on paraffinembedded sections on the basis of cell nuclear morphology after DNA staining and/or by cytochemical reactions (TUNEL assay, immunodetection of the proteolytic poly (ADP-ribose) polymerase-1 [PARP-1] fragment); biochemical procedures (identifying DNA fragmentation or PARP-1 proteolysis) were also used. Indirect immunofluorescence techniques were performed to label specific antigens for either vSMCs or macrophages (i.e., the cells which are most likely prone to apoptosis in atherosclerotic lesions): the proper selection of fluorochrome labeling allowed the simultaneous detection of the cell phenotype and the apoptotic characteristics, by multicolor fluorescence techniques. Apoptotic cells proved to be less than 5% of the whole cell population, in atherosclerotic plaque sections: this is, in fact, a too low cell fraction to be detected by widely used biochemical methods, such as agarose gel electrophoresis of low-molecular-weight DNA or Western-blot analysis of PARP-1 degradation. Most apoptotic cells were of macrophage origin, and clustered in the tunica media, near or within the lipid-rich core; only a few TUNEL-positive cells were labeled for antigens specific for vSMCs. These results confirm that, among the cell populations in atherosclerotic plaques, macrophage foam-cells are preferentially involved in apoptosis. Their death may decrease the cell number in the lipid core and generate a possibly defective apoptotic clearance: the resulting release of matrix-degrading enzymes could contribute to weakening the fibrous cap and promote the plaque rupture with the risk of acute ischemic events, while increasing the thrombogenic pultaceous pool of the plaque core

    Clearance Operation of Teulada Site (Italy): A Novel Approach for Short Term MCM Missions in Seafloor Hard Conditions

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    In May 2007, following a request by Italian Navy (ITN), NURC agreed to provide the technology, developed during the port protection studies and 2006 MCM ops. in Baltic sea for Estonian Navy, to survey part of the Capo Teulada firing range (Sardinia Island, Italy), used by NATO Armed Forces. The goal of the service, fully funded by ITN, was to survey part of the firing range with acoustic, magnetic and optical instruments in order to detect and classify the ordnance laying on the seafloor. The team operated from CRV Leonardo to produce a detailed acoustic and magnetic map of the area. The positions of the targets of interest have been provided to Italian Navy for further identification and disposal. The activities have demonstrated that the NURC Autonomous Underwater Vehicles (AUVs) Remus type equipped with high frequency side scan sonar can detect and classify targets of the dimensions of unexploded ordnance laying proud on the sea floor. A multiple sonar images technique has also been used to improve the classification performances. However, in some areas, targets that were completely buried or concealed in Posidonia fields wouldn’t have been detectable with AUV sonar. To overcome this limitation, INGV supported the NURC team by using a new high definition magnetometer technique to detect and classify buried metal targets. A proton Overhauser sensor was towed from Leonardo vessel and a magnetometer reference station was set ashore in an appropriate site. A subset of interesting contacts (acoustic and magnetic) have been identified optically by means of the video camera installed on the ROV (Pluto Plus type by Gaymarine) operated from Leonardo. The positioning accuracy achieved was fully compatible with the reacquisition by ROV and then by divers or mine hunters for future disposal ops. The survey has also produced an accurate map of the Posidonia fields and a detailed bathymetry of the area. More than 300 contacts have been acquired and more than 200 were classified in less than 15 days. The success of Teulada operation has convinced ITN to ask NURC for a common development programme with the aim to validate at sea a fully integrated multi-sensor approach (sonar, magnetic and optical) in MCM short term ops. using USV/AUV platforms

    SplitBox: Toward Efficient Private Network Function Virtualization

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    This paper presents SplitBox, an efficient system for privacy-preserving processing of network functions that are outsourced as software processes to the cloud. Specifically, cloud providers processing the network functions do not learn the network policies instructing how the functions are to be processed. First, we propose an abstract model of a generic network function based on match-action pairs. We assume that this function is processed in a distributed manner by multiple honest-but-curious cloud service providers. Then, we introduce our SplitBox system for private network function virtualization and present a proof-of-concept implementation on FastClick, an extension of the Click modular router, using a firewall as a use case. Our experimental results achieve a throughput of over 2 Gbps with 1 kB-sized packets on average, traversing up to 60 firewall rules

    Effect of platelet lysate on human cells involved in different phases of wound healing

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    Background Platelets are rich in mediators able to positively affect cell activity in wound healing. Aim of this study was to characterize the effect of different concentrations of human pooled allogeneic platelet lysate on human cells involved in the different phases of wound healing (inflammatory phase, angiogenesis, extracellular matrix secretion and epithelialization). Methodology/Principal Findings Platelet lysate effect was studied on endothelial cells, monocytes, fibroblasts and keratinocytes, in terms of viability and proliferation, migration, angiogenesis, tissue repair pathway activation (ERK1/2) and inflammatory response evaluation (NFÎşB). Results were compared both with basal medium and with a positive control containing serum and growth factors. Platelet lysate induced viability and proliferation at the highest concentrations tested (10% and 20% v/v). Whereas both platelet lysate concentrations increased cell migration, only 20% platelet lysate was able to significantly promote angiogenic activity (p<0.05 vs. control), comparably to the positive control. Both platelet lysate concentrations activated important inflammatory pathways such as ERK1/2 and NFÎşB with the same early kinetics, whereas the effect was different for later time-points. Conclusion/Significance These data suggest the possibility of using allogeneic platelet lysate as both an alternative to growth factors commonly used for cell culture and as a tool for clinical regenerative application for wound healing

    Harbour Sea-floor Clearance: “HD” High Definition Magnetic Survey Performance

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    Seafloor clearance methods based on acoustic, direct-inspection, and single-sensor magnetic approaches suffer from limitations in controlling the target-sensor distance, and may prove ineffective when the small size or the dangerous nature of targets requires high accuracy in localization. Moreover, random magnetic variations over time bring about spatial decorrelation phenomena, and hinder the application of double-sensor methods in noisy harbour environments. The new High Definition (HD) magnetic survey protocol tackles the measurement-distance problem in two ways: first, by varying the sensor depth dynamically, and secondly by backprojecting the measured field according to seafloor data and vertical incremental factors associated with the bandwidth characteristics of targets. The method to make up for timeinduced loss in spatial localization ability exploits the local behaviour of a coherence function, which correlates local observations to a set of spatially-stabilized reference stations. The consequent normalization of measured magnetic signals allows one to assign the monitored areas with a specific level of confidence in the detection results, ranging from 100% (certainty) to 0% (random events). The principles of HD detection have been fully applied in the seafloor clearance of the firing test site located south of Cape Teulada (Sardinia, Italy), where very weak signal sources such as cartridge cases, mines, and small objects down to 1 Kg mass values (lobster pots) have been successfully localized, even when covered by extensive colonies of Posidonia

    Identification of particles with Lorentz factor up to 10410^{4} with Transition Radiation Detectors based on micro-strip silicon detectors

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    This work is dedicated to the study of a technique for hadron identification in the TeV momentum range, based on the simultaneous measurement of the energies and of the emission angles of the Transition Radiation (TR) X-rays with respect to the radiating particles. A detector setup has been built and tested with particles in a wide range of Lorentz factors (from about 10310^3 to about 4Ă—1044 \times 10^4 crossing different types of radiators. The measured double-differential (in energy and angle) spectra of the TR photons are in a reasonably good agreement with TR simulation predictions.Comment: 31 pages, 12 figures, paper published on Nuclear Instruments & Methods
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