171,700 research outputs found
Recent R&D to improve the time resolution and rate capability of the Multigap Resistive Plate Chamber
No full textIn 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
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
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
Designing iLook:an integrated, zoomable interface to support users’ interaction with networked home appliances.
No full textiLook is a user interface designed to support everyday interaction between people and home appliances focusing on four potential assets provided to us by a leading home appliances manufacturer as a design brief: a) remote control; b) assistance and maintenance; c) ecological-economic impact; d) social networking. We discuss the participatory design process we followed firstly focusing on the future workshops and cultural probe phase where mixed groups of researchers, designers and managers from the manufacturing companyand end-users produced concepts and innovative services. The concepts were enriched and refined through diaries given to the participants who produced envisioning scenarios that that described how the concepts would influence their everyday interaction with appliances. Then secondly on the role prototyping workshop where 22 interaction design students produced sketches, explored unexpressed features, functionalities and contexts of use of the earlier concepts through the use of scenarios. To organize the outcomes of the earlier phaseswe devised a five-level information architecture for interaction with home appliances in the physical space and mapped the four assets on to each level. As a result of the process we present three steps towards the final prototype ofiLook, a zooming user interface (ZUI) that embodies some focus+context and augmented reality features allowing the integration of the different assets on the diverse home appliances in one unifying context. We discuss users feedback for each presented prototype and the guidelines we derived for further redesign
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