1,723,381 research outputs found
Recent R&D to improve the time resolution and rate capability of the Multigap Resistive Plate Chamber
Get PDFIn this study the results of tests performed at the T10 beam line at CERN on three novel MRPC detectors are reported. The tested detectors have different designs suited for different R&D goals: one detector has been built to improve the already excellent time resolution of the MRPC technology; the other two detectors have been designed and constructed to improve the MPRC rate capabilities. All the detectors are built maintaining the basic features of MRPCs: low price and ease of construction. The solutions adopted and described in this work for the time resolution improvement lead to a detection efficiency close to 100%, demonstrating the chamber functionality. To increase the MRPCs rate capabilities, a painted layer has been added to the surfaces of the MRPCs inner glass sheets. The measurements and tests performed showed that this solution can indeed increase the rate capability of the detector with respect to standard MRPC
Performance of the ALICE Time-Of-Flight detector at the LHC
No full textThe ALICE Time-Of-Flight (TOF) detector at LHC is based on the Multigap Resistive Plate Chambers (MRPCs). The TOF performance during LHC Run 2 is here reported. Particular attention is given to the improved time resolution reached by TOF detector of 56 ps, with the consequently improved particle identification capabilities.The ALICE Time-Of-Flight (TOF) detector at LHC is based on the Multigap Resistive Plate Chambers (MRPCs). The TOF performance during LHC Run 2 is here reported. Particular attention is given to the improved time resolution reached by TOF detector of ps, with the consequently improved particle identification capabilities
Chimioprévention des cancers intestinaux par le géraniol,un monoterpène microconstituant des fruits et plantes aromatiques (Aspects moléculaire, cellulaire et physiopathologique)
No full textNos travaux ont montré que le géraniol, un monoterpène acyclique présent dans les huiles essentielles végétales, exerce un pouvoir anti-prolifératif sur les cellules cancéreuses coliques humaines Caco-2 (Carnesecchi, 2001). Nos résultats ont montré que le géraniol induit une dépolarisation membranaire. Cette perturbation membranaire entraîne une inhibition de la protéine kinase C et une inhibition de la phosphorylation de ERK1&2 (Carnesecchi, 2002). De plus, le géraniol induit une inhibition de la synthèse d'ADN. Aucun signe d'apoptose, ni de cytotoxicité n'a été détecté. Ainsi, le changement de la perméabilité membranaire et les effets cellulaires du géraniol pourraient expliquer son effet anti-prolifératif.Il a été montré que les cellules Caco-2 à confluence expriment des caractéristiques de différenciation entérocytaire. La présence de ces cellules pourraient expliquer la forte résistance des tumeurs coliques à la chimiothérapie (Lesuffleur, 1998). Nos travaux ont montré que le géraniol bloque la différenciation des cellules Caco-2. Une combinaison du géraniol et du 5-Fluorouracile (5-FU) a été testée sur ces cellules différenciées. Les résultats montrent que le géraniol sensibilise les cellules Caco-2 au traitement par le 5-FU en augmentant ses effets anti-prolifératifs et cytotoxiques. Ces effets sont corrélés à une entrée facilitée du 5-FU (Carnesecchi, 2001).Une approche expérimentale in vivo a été entreprise afin de tester les effets de la combinaison de géraniol et de 5-FU sur la croissance de tumeurs coliques humaines TC118 implantées chez des souris athymiques. La combinaison de 5-FU (20mg/kg) et de géraniol (150 mg/kg) entraîne une réduction du volume tumoral relatif de 53% par rapport à 26 % avec du géraniol seul et à 0 % pour le 5-FU seul par rapport à des souris non traitées.En conclusion, le géraniol sensibilise les cellules tumorales coliques humaines aux agents de la chimiothérapie, en agissant sur la perméabilité des membranes cellulaires.Ours studies have shown that geraniol, an acyclic monoterpene found in vegetal essential oil, caused inhibition of human colonic cancer cells (Caco-2) growth (Carnesecchi, 2001). Ours results have shown that geraniol induced membrane depolarization. This membrane perturbation lead to Protein Kinase C inhibition and inhibition of ERK 1&2 phosphorylation (Carnesecchi, 2002). Geraniol induced inhibition of ADN synthesis. Nor apoptosis, nor cytotoxicity has been detected. Then, changes in membrane permeability and cellular effects of geraniol could explain antiproliferative effect of geraniol.It has been shown that Caco-2 cells, at confluency, expressed characteristics of enterocytes differentiation. The presence of these cells could explain the increased resistance of colonic tumors to chemotherapeutic agents (Lesuffleur, 1998). Ours studies have shown that geraniol blocked Caco-2 cell differentiation. Combination of geraniol and 5-Fluorouracil (5-FU) was tested on differentiated Caco-2 cells. These results have shown that geraniol sensitized Caco-2 cells to 5-FU treatment, by increasing its antiproliferative and cytotoxic effects. These effects result from facilitate entry of 5-FU (Carnesecchi, 2001).The effects of geraniol and 5-FU were also evaluated in vivo on the growth of 5-FU-resistant human colonic tumour cells (TC-118) transplanted in Swiss nu/nu mice. The combined intraperitoneal administration of 5-FU (20 mg/kg/day) and geraniol (150 mg/kg/day) caused a 53% reduction of the tumour volume after 7 days compared to a reduction of 26% with geraniol alone. 5-FU alone had no effect on the development of the tumour.We conclude that the combined administration of geraniol and 5-FU sensitizes human colonic tumours to 5-FU treatment. This combination appears as promising approach for optimizing colorectal cancer chemotherapy.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF
Light detection in DarkSide-20k
No full textThe Darkside experiment aims at the direct detection of WIMPs using a dual phase liquid Argon TPC . The next generation experiment, DarkSide-20k, will push the fiducial mass liquid argon to 20 tonnes. The light detection is a crucial part of the project; DS-20k will use, instead of the standard PhotoMultipliers (PMs), the Silicon PhotoMultipliers (SIPMs). This kind of photo-sensors will permit a higher photo-detection efficiency and a lower background, compared to standard PMs. The TPC will be outfitted with about 200,000 SiPMs grouped into 8200 single readout channels, 25 cm2 Photo Detection Module (PDM) . In this paper, the design and performance of the PDMs will be reported. The strategy to scale from the R&D to the DS-20k will be also discussed, together with recent results obtained from the first prototype Darkside-Proto-0 detector
Il contributo dei cortonesi alla coltura italiana;
No full text"Il presente opuscolo complete l'opera Cortona nel medio evo di G. Mancini. Firenze, Tip. Carnesecchi, 1897.Cover title: I cortonesi illustratisi nella dottrina a nelle belle arti.Bibliographical footnotes.Mode of access: Internet
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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