337 results on '"Martin, Yves"'
Search Results
302. Marcel TRUDEL, Atlas historique du Canada français
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Martin, Yves, primary
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- 1961
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303. Etude demographique de la region du Bas Saint-Laurent
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C., J.-C., primary and Martin, Yves, additional
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- 1961
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304. La population de Quebec et de ses regions, 1961-1981
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P., Y., primary, Henripin, Jacques, additional, and Martin, Yves, additional
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- 1966
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305. Une source de l'histoire coloniale du Sénégal : Les rapports de situation politique (1874-1891)
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Saint-Martin, Yves J., primary
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- 1965
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306. Un centenaire oublié, Eugène-Abdon Mage (1837-1869)
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Saint-Martin, Yves J., primary
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- 1970
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307. Technique de moulage de gravures rupestres
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Martin, Yves, primary
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- 1974
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308. Niveau de vie des familles suivant le nombre d'enfants
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Martin, Yves, primary
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- 1956
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309. Un fils d'El Hadj Omar : Aguibou, roi du Dinguiray et du Macina (1843 ?-1907)
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Saint-Martin, Yves, primary
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- 1968
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310. Enabling large-scale deployment of photonics through cost-efficient and scalable packaging.
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Barwicz, Tymon, Taira, Yoichi, Lichoulas, Ted W., Boyer, Nicolas, Numata, Hidetoshi, Martin, Yves, Nah, Jae-Woong, Takenobu, Shotaro, Janta-Polczynski, Alexander, Kimbrell, Eddie L., Leidy, Robert, Khater, Marwan, Kamlapurkar, Swetha, Engelmann, Sebastian, Vlasov, Yurii A., and Fortier, Paul
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- 2015
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311. Mémoires d'un révolutionnaire tranquille.
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Martin, Yves
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- 2006
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312. Effects of fire severity and initial tree composition on understorey vegetation dynamics in a boreal landscape inferred from chronosequence and paleoecological data
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Lecomte, Simard, Bergeron, Larouche, Asnong, Richard, Nicolas, Martin, Yves, Alayn, Hans, Pierre J. H., Lecomte and Pärtel, M.
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- 2005
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313. My Life at the Bar and Beyond.
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Martin, Yves
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AUTOBIOGRAPHY ,NONFICTION - Abstract
The article reviews the book "My Life at the Bar and Beyond," by Alex K. Paterson.
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- 2007
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314. Exogenous orienting of attention in hearing: a virtual reality paradigm to assess auditory attention in neglect patients.
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Guilbert, Alma, Clément, Sylvain, Martin, Yves, Feuillet, Alexia, and Moroni, Christine
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AUDITORY selective attention , *HEARING , *UNILATERAL neglect , *CEREBRAL dominance , *TASK performance - Abstract
While mechanisms of orienting attention in unilateral spatial neglect (USN) have frequently been studied in the visual domain, these mechanisms remain relatively unexplored in the auditory domain. Our first goal was to replicate Spence and Driver's (J Exp Psychol Hum 22:1005-1030, 1994) results with a virtual reality paradigm. This paradigm simulated a 3-dimensional auditory space with headphones. Our second aim was to study auditory profiles of orienting attention in USN. In a first experiment, 18 healthy participants performed an auditory cueing spatial paradigm (either a target-detection task or a target-lateralization task). In a second experiment, 14 right-stroke patients (10 with USN and 4 without USN) performed these two same tasks. As in Spence and Driver's (J Exp Psychol Hum 22:1005-1030, 1994), our first experiment showed that spatial representations are not utilized for the detection of auditory stimuli. However, during the lateralization task, participants were quicker to detect targets preceded by a spatially congruent cue, which suggests that our paradigm could be suitable for studying orienting attention in hearing. Our second experiment found that patients with USN also needed an explicit spatial task to be sensitive to auditory spatial cueing. In the target-lateralization task, they showed effects lateralized only to one side of space, whereas patients without USN did not. Although our paradigm needs replications to better understand orienting attention impairments in hearing in USN, this study could have implications for the development of clinical tasks that could assess auditory spatial attention in USN syndrome. [ABSTRACT FROM AUTHOR]
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- 2016
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315. Assessing the accuracy of a new hand hygiene monitoring device (SmartRub®): from the laboratory to clinical practice.
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Guitart, Chloé, Robert, Yves-Alain, Lotfinejad, Nasim, Fourquier, Simon, Martin, Yves, Pires, Daniela, Sauser, Julien, Beuchat, René, and Pittet, Didier
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HAND care & hygiene , *MEDICAL personnel , *PATHOLOGICAL laboratories , *ELECTRONIC equipment , *ELECTRONIC surveillance - Abstract
Background: We developed SmartRub® powered by iQati®, an electronic device composed of a wristband and an alcohol-based handrub pocket-sized dispenser that measures and provides feedback on the duration of hand friction and the volume poured during each hand hygiene action. We aimed to assess the accuracy of SmartRub®. Methods: The specificity, sensitivity, positive and negative predictive values (PPV and NPV) of SmartRub® were assessed in a 3-phased experiment: (1) laboratory-controlled conditions with volunteers; (2) pre-planned clinical path with volunteers and (3) real clinical conditions with healthcare workers. The accuracy of SmartRub® was evaluated by quantifying its ability to correctly capture true hand hygiene actions and to not record other actions performed while wearing the device. Results: In the laboratory, 7 volunteers performed 816 actions. Overall sensitivity was 94.1% (95% CI 91.4–96.2%) with a PPV of 99.0% (95% CI 97.3–99.6%) and specificity was 99.0% (95% CI 97.5–99.7%) with a NPV of 94.4% (95% CI 91.9–96.1%). During the pre-planned clinical path phase, 13 volunteers performed 98 planned paths and a total of 967 actions were performed. Overall sensitivity was 94.6% (95% CI 92.2–96.5%) with a PPV of 84.3% (95% CI 81.6–86.7%) and specificity was 82.4% (95% CI 78.7–85.7%) with a NPV of 93.9% (95% CI 91.3–95.7%). During the real clinical conditions phase, 17 healthcare workers were observed for a total of 15 h and 3 min while they performed 485 actions. Sensitivity was 96.8% (95% CI 93.8–98.6%) with a PPV of 98.3% (95% CI 95.6–99.3%) and specificity was 98.3% (95% CI 95.7–99.5%) with a NPV of 96.8% (95% CI 93.9–98.4%). Conclusions: Smartrub® is a highly reliable device for capturing hand hygiene actions under a range of conditions, from the laboratory to clinical care activities. [ABSTRACT FROM AUTHOR]
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- 2021
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316. Québec, quatre siècles d'une capitale/Québec, la capitale romantique.
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MARTIN, Yves
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NONFICTION - Abstract
The article reviews the books "Québec, quatre siècles d'une capitale," by Christian Blais, Gilles Gallichan, Frédéric Lemieux and Jocelyn Saint-Pierre, and "Québec, la capitale romantique," by Luc-Antoine Couturier and Chrystine Brouillet.
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- 2009
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317. René Lévesque, un homme et son rêve (1922-1987).
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MARTIN, Yves
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NONFICTION - Abstract
The article reviews the book "René Lévesque, un homme et son rêve (1922-1987)," by Pierre Godin.
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- 2008
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318. Les trains qui passent. Propos et souvenirs d'un citoyen libre.
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Martin, Yves
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HISTORY of Quebec (Province) ,NONFICTION - Abstract
The article reviews the book "Les trains qui passent. Propos et souvenirs d'un citoyen libre," by Louis O'Neill.
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- 2007
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319. Automated, high-throughput photonic packaging.
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Barwicz, Tymon, Lichoulas, Ted W., Taira, Yoichi, Martin, Yves, Takenobu, Shotaro, Janta-Polczynski, Alexander, Numata, Hidetoshi, Kimbrell, Eddie L., Nah, Jae-Woong, Peng, Bo, Childers, Darrell, Leidy, Robert, Khater, Marwan, Kamlapurkar, Swetha, Cyr, Elaine, Engelmann, Sebastian, Fortier, Paul, and Boyer, Nicolas
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PHOTONICS , *PHOTONICS research , *SILICON , *MICROELECTRONICS , *WAVEGUIDES - Abstract
Silicon photonics can enable optical circuits of unprecedented complexity and cost efficiency. It employs lithography to effectively pre-assemble optical devices on wafers fabricated in existing microelectronic facilities with decades of cost and reliability optimization. Unfortunately, the packaging of photonic chips still employs legacy approaches, which limit the device’s cost efficiency and scalability. To address this challenge, we have developed a novel approach to photonic packaging centered on shifting complexity from chip-level assembly to wafer-level planar fabrication. Self-alignment structures and large-mode converters are integrated on chip to enable photonic packaging in standard, automated, high-throughput microelectronic assembly tools. We demonstrate solutions to interfacing standard optical fibers to chips and to interfacing photonic chips to other photonic chips. We show wide spectral bandwidth and a peak transmission of −1.3 dB from a standard fiber patch cable to chip and −1.1 dB from chip to chip. We believe this new direction can help silicon photonics reach its full potential. [ABSTRACT FROM AUTHOR]
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- 2018
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320. Neutral beam heating on the TCV tokamak.
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Karpushov, Alexander N., Chavan, René, Coda, Stefano, Davydenko, Vladimir I., Dolizy, Frédéric, Dranitchnikov, Aleksandr N., Duval, Basil P., Ivanov, Alexander A., Fasel, Damien, Fasoli, Ambrogio, Kolmogorov, Vyacheslav V., Lavanchy, Pierre, Llobet, Xavier, Marlétaz, Blaise, Marmillod, Philippe, Martin, Yves, Merle, Antoine, Perez, Albert, Sauter, Olivier, and Siravo, Ugo
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ELECTRON cyclotron resonance heating , *PLASMA pressure , *TOKAMAKS , *SUPERIONIC conductors , *DEUTERIUM plasma ,DESIGN & construction - Abstract
The TCV tokamak contributes to physics understanding in fusion reactor research by harnessing a wide experimental tool set: in particular flexible shaping and high power electron cyclotron heating. Plasma regimes with high plasma pressure, a wider range of temperature ratios and significant fast-ion population are now attainable with a TCV heating system upgrade. In a first stage, a 1 MW neutral beam was installed (2015) and is reported in this paper. The installation of the NB injector required modifications of the vacuum vessel and considerable work on the machine infrastructure, resulting in a shutdown from late 2013 to mid-2015. TCV is now operating partly as a European Medium-Size Tokamak (MST) facility under the auspices of the EUROfusion consortium. The NBI was intensively operated in the February–July 2016 phase of the MST campaign. Record ion temperatures of 2.0–2.5 keV and toroidal rotation velocities up to 160 km/s were promptly attained in the first few L-mode discharges with NB injection. Ion temperatures up to 3.5 keV were subsequently achieved in ELMy H-mode. The injector produces a focused deuterium neutral beam with 25 keV energy, 1 MW neutral power and 2 s duration. [ABSTRACT FROM AUTHOR]
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- 2017
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321. Upgrade of the neutral beam heating system on the TCV tokamak – second high energy neutral beam.
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Karpushov, Alexander N., Bagnato, Filippo, Baquero-Ruiz, Marcelo, Coda, Stefano, Colandrea, Claudia, Dolizy, Frédéric, Dubray, Jérémie, Duval, Basil P., Fasel, Damien, Fasoli, Ambrogio, Jacquier, Rémy, Lavanchy, Pierre, Marlétaz, Blaise, Martin, Yves, Martinelli, Lorenzo, Mykytchuk, Dmytry, Pedrini, Marta M., Poley, Jesús, Reimerdes, Holger, and Sheikh, Umar
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NEUTRAL beams , *FUSION reactors , *PLASMA beam injection heating , *PLASMA physics , *TOKAMAKS , *HEATING , *PLASMA flow - Abstract
• A second 1.2 MW/53 keV high-energy neutral beam (NBI-2) procured, manufactured and installed on TCV. • NBI-2 is designed to probe plasma physics issues of higher plasma density, fast ion plasma interactions with static and dynamic fields and plasma rotation. • The higher NBI-2 energy together with NBI-1 (1.3 MW/28 keV) greatly enhances the operational space for fast ion studies and plasma heating with up to 2.5 MW NBH power. The TCV tokamak continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to provide a stepladder approach for extrapolations of experimental results from different machines to ITER and DEMO. TCV's configurational flexibility has recently been enhanced by the installation of two heating neutral beams, new dual frequency gyrotrons, removable divertor gas baffles together with upgrades of its diagnostic infrastructure. Plasma regimes with high plasma pressure, a wider range of temperature ratios and significant fast-ion population are now attainable on TCV. A 1.3 MW/28 keV heating beam (NBI-1) has been operated on TCV from 2015 introducing the direct ion auxiliary heating. A second 1MW/50–60 keV high-energy neutral beam (NBI-2) has since been procured, manufactured and installed on TCV in July 2021. NBI-2 injected near anti-co-linearly to NBI-1 is designed to probe plasma physics issues of higher plasma density, fast ion plasma interactions with static and dynamic fields and plasma rotation. The higher NBI-2 energy greatly enhances the operational space for fast ion studies. NBI-2 commissioning is presently ongoing in parallel with TCV experiments using both NBIs. This paper summarises the experience with intensive use and improvements of the NBI-1, together with the status of NBI-2 commissioning. [ABSTRACT FROM AUTHOR]
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- 2023
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322. Auditory lateralisation deficits in neglect patients.
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Guilbert, Alma, Clément, Sylvain, Senouci, Latifa, Pontzeele, Sylvain, Martin, Yves, and Moroni, Christine
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UNILATERAL neglect , *HEARING disorders , *INTERAURAL time difference , *EGOISM , *STROKE , *PATIENTS - Abstract
Although visual deficits due to unilateral spatial neglect (USN) have been frequently described in the literature, fewer studies have been interested in directional hearing impairment in USN. The aim of this study was to explore sound lateralisation deficits in USN. Using a paradigm inspired by Tanaka et al. (1999) , interaural time differences (ITD) were presented over headphones to give the illusion of a leftward or a rightward movement of sound. Participants were asked to respond “right” and “left” as soon as possible to indicate whether they heard the sound moving to the right or to the left side of the auditory space. We additionally adopted a single-case method to analyse the performance of 15 patients with right-hemisphere (RH) stroke and added two additional measures to underline sound lateralisation on the left side and on the right side. We included 15 patients with RH stoke (5 with a severe USN, 5 with a mild USN and 5 without USN) and 11 healthy age-matched participants. We expected to replicate findings of abnormal sound lateralisation in USN. However, although a sound lateralisation deficit was observed in USN, two different deficit profiles were identified. Namely, patients with a severe USN seemed to have left sound lateralisation impairment whereas patients with a mild USN seemed to be more influenced by a systematic bias in auditory representation with respect to body meridian axis (egocentric deviation). This latter profile was unexpected as sounds were manipulated with ITD and, thus, would not be perceived as coming from an external source of the head. Future studies should use this paradigm in order to better understand these two distinct profiles. [ABSTRACT FROM AUTHOR]
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- 2016
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323. Upgrade of the TCV tokamak, first phase: Neutral beam heating system.
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Karpushov, Alexander N., Alberti, Stefano, Chavan, René, Davydenko, Vladimir I., Duval, Basil P., Ivanov, Alexander A., Fasel, Damien, Fasoli, Ambrogio, Gorbovsky, Aleksander I., Goodman, Timothy, Kolmogorov, Vyacheslav V., Martin, Yves, Sauter, Olivier, Sorokin, Aleksey V., and Toussaint, Matthieu
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TOKAMAKS , *NEUTRAL beams , *HEATING , *PLASMA pressure , *TEMPERATURE effect - Abstract
Experiments on TCV are designed to complement the work at large integrated tokamak facilities (such as JET) to provide a stepwise approach to extrapolation to ITER and DEMO in areas where medium-size tokamaks can often exploit their experimental capabilities and flexibility. Improving the understanding and control requirements of burning plasmas is a major scientific challenge, requiring access to plasma regimes and configurations with high normalized plasma pressure and a wide range of ion to electron temperature ratios, including T e / T i ∼ 1. These conditions will be explored by adding a 1 MW neutral heating beam to TCV's auxiliary for direct ion heating (2015) and increasing the ECH power injected in X-mode at the third harmonic (2 MW in 2015–2016). The manufacturing of the neutral beam injector was launched in 2014. [ABSTRACT FROM AUTHOR]
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- 2015
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324. Development of a mass spectrometry method for the determination of a melanoma biomarker, 5-S-cysteinyldopa, in human plasma using solid phase extraction for sample clean-up
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Martin, Gaëlle B., Chiap, Patrice, Paquet, Philippe, Pierard, Gerald, de Tullio, Pascal, Martin, Yves, Rozet, Eric, Hubert, Philippe, Crommen, Jacques, and Fillet, Marianne
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NEUROENDOCRINE tumors , *TUMORS , *MELANOMA , *MERKEL cell carcinoma - Abstract
Abstract: 5-S-cysteinyldopa is a well-known pigment intermediate and analysis of its plasma concentration is interesting for the early diagnosis, as well as for evaluation of treatment and follow-up of malignant melanoma. A determination method of 5-SCD in human plasma was developed using solid phase extraction (SPE) on disposable cartridges and liquid chromatography electrospray mass spectrometry (LC-ESI–MS–MS). Compound''s sensitivity to light and oxidation requires the addition of anti-oxidative agents (AO), to work in acidic media at 4°C and to avoid light exposure of samples since blood collection. Different solid phases involving covalent binding to phenylboronic groups or dual retention mechanisms were evaluated and extraction cartridges containing both hydrophobic and strong cation exchange functionalities were finally selected. The LC separation of 5-SCD from endogenous catecholamines was achieved by gradient elution on a C18 stationary phase. 5-SCD was detected by multiple reaction monitoring (MRM) performed on ES(+) generated ions. Finally, the method was prevalidated in the lower ng/ml range. Good results with respect to accuracy, trueness and precision were obtained. [Copyright &y& Elsevier]
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- 2007
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325. Divided attention and mental effort after severe traumatic brain injury
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Azouvi, Philippe, Couillet, Josette, Leclercq, Michel, Martin, Yves, Asloun, Sybille, and Rousseaux, Marc
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BRAIN injuries , *SHORT-term memory , *FATIGUE (Physiology) , *TASK performance - Abstract
The aim of this study was to assess dual-task performance in TBI patients, under different experimental conditions, with or without explicit emphasis on one of two tasks. Results were compared with measurement of the subjective mental effort required to perform each task. Forty-three severe TBI patients at the subacute or chronic phase performed two tasks under single- and dual-task conditions: (a) random generation; (b) visual go–no go reaction time task. Three dual-task conditions were given, requiring either to consider both tasks as equally important or to focus preferentially on one of them. Patients were compared to matched controls. Subjective mental effort was rated on a visual analogic scale. TBI patients showed a disproportionate increase in reaction time in the go–no go task under the dual-task condition. However, they were just as able as controls to adapt performance to the specific instructions about the task to be emphasised. Patients reported significantly higher subjective mental effort, but the variation of mental effort according to task condition was similar to that of controls. These results suggest that the divided attention deficit of TBI patients is related to a reduction in available processing resources rather than an impairment of strategic processes responsible for attentional allocation and switching. The higher level of subjective mental effort may explain why TBI patients frequently complain of mental fatigue, although this subjective complaint seems to be relatively independent of cognitive impairment. [Copyright &y& Elsevier]
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- 2004
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326. Beam duct for the 1 MW neutral beam injector on TCV.
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Toussaint, Matthieu, Coda, Stefano, Dolizy, Frédéric, Duval, Basil, Karpushov, Alexander N., Martin, Yves, and Maurizio, Roberto
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NEUTRAL beams , *INJECTORS , *PLASMA beam injection heating , *HEAT flux , *THERMAL analysis , *ION sources - Abstract
The 1MW power of the neutral beam injector (NBI) enters the plasma of the Tokamak à Configuration Variable (TCV) through a duct. The original beam propagation model predicted a maximal heat flux on the internal faces of the duct below 350 kW/m2, leading to an acceptable temperature rise for the 2 s nominal pulse duration. During commissioning, the NBI showed unacceptable overheating in the duct, the beam divergence being higher than expected. Several ion source grids have been tested to mitigate the beam divergence however the overheating of the duct is still problematic. Since then, the NBI operates with reduced power and duration to avoid damaging the beam duct. This paper describes the design and thermal analysis of a new beam duct capable of withstanding NBI shots at nominal regime for a range of modeled neutral beam divergences. The design drivers are the high heat flux protection and the accumulated heat dissipation. The concept features a thermal shield composed of a smooth elliptical castellated layer surrounded by an actively cooled structure. [ABSTRACT FROM AUTHOR]
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- 2020
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327. Le fret ferroviaire
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Bourissou, Alain, Mordant, Paul, MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL), École nationale supérieure des mines de Paris, and Martin, Yves
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Transport ferroviaire ,Transports ferroviaires ,Transport marchandise ,rameau ,Thèses et écrits académiques ,[SHS]Humanities and Social Sciences - Abstract
Bibliogr
- Published
- 1998
328. Edge Localized Mode Control in TCV
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Rossel, Jonathan, Moret, Jean-Marc, and Martin, Yves
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resonant magnetic perturbation ,Tokamak ,champ d'erreur ,error field ,perturbation magnétique résonante ,ergodique ,bord du plasma ,chauffage par résonance avec des ondes cyclotroniques électroniques ,confinement magnétique ,mode localisé au bord ,Physics::Plasma Physics ,plasma ,contrôle ,vertical control ,electron cyclotron resonant heating ,bobine selle ,magnetic confinement ,plasma edge ,contrôle en temps réel ,Lagrange ,edge localized mode ,ergodic ,puissance modulée ,contrôle vertical ,TCV ,real-time control ,saddle coil ,control ,power modulation - Abstract
The Tokamak concept, based on magnetic confinement of a hydrogen plasma, is one of today's most promising paths to energy production by nuclear fusion. The experimental scenarios leading to the largest fusion rate are based on a high confinement plasma regime, the H-mode, in which the energy and particle confinement are enhanced by a transport barrier located at the plasma edge and forming a pedestal in the plasma pressure profile. In standard axisymmetric magnetic configurations, stationary H-mode regimes suffer from instabilities of the plasma edge, the so-called edge localized modes (ELMs), leading to potentially damaging repetitive ejections of heat and particles toward the plasma facing components. In ITER, a Tokamak currently being built to demonstrate net power production from fusion, type I ELMs are expected to occur during high performance discharges. It is expected that the power flux released by these ELMs will cause an intolerable erosion and heat load on the plasma facing components. The control of ELMs, in terms of frequency and energy loss, is therefore of primary importance in the field of magnetic fusion and is subject to an intense research effort worldwide. This thesis, in line with this effort, focuses on two particular ELM control methods: local continuous or modulated heating of the plasma edge, and application of resonant magnetic perturbations (RMP). In this thesis, the effects of plasma edge heating on the ELM cycle have been investigated by applying electron cyclotron resonant heating (ECRH) to the edge of an H-mode plasma featuring type I ELMs in the Tokamak à Configuration Variable (TCV). As the power deposition location is shifted gradually toward the plasma pressure pedestal, an increase of the ELM frequency by a factor 2 and a decrease of the energy loss per ELM by the same factor are observed, even though the power absorption efficiency is reduced. This unexpected and, as yet, unexplained phenomenon, observed for the first time, runs contrary to the intrinsic type I ELM power dependence and provides a new approach for ELM mitigation. The effects of heating power modulation on the ELM cycle have also been experimentally investigated. It showed that power modulation synchronized in real-time with the ELM cycle is able to pace the ELMs with low deviation from a given frequency. Experimental results also clearly indicate that the ELM frequency purely remains a function of the heating power averaged over the ELM cycle, so that power modulation itself is not able to drive the ELM frequency and only has a stabilization effect. These results are in qualitative agreement with a simple 0D finite confinement time integrator model of the ELM cycle. RMP consists in applying a magnetic field perpendicular to the plasma magnetohydrodynamic equilibrium flux surfaces with a spatial variation tuned to align with the equilibrium magnetic field lines. If each coil of an RMP coil system (i.e. a set of toroidally and poloidally distributed coils) is powered with an independent power supply, the coil current distribution can be tuned to optimize the RMP space spectrum. In the course of this thesis, a multi-mode Lagrange method, with no assumption on the coil geometry or spatial distribution, has been developed to determine this optimum, in the limit of the vacuum magnetic field approximation. This method appears to be an efficient way to minimize the parasitic spatial modes of the magnetic perturbation, and the coil current requirements, while imposing the amplitude and phase of a set of target modes. A figure of merit measuring the quality of a perturbation spectrum with respect to RMP independently of the considered coil system or plasma equilibrium is also proposed. To facilitate the application of the Lagrange method, a spectral characterization of the coil system, based on a generalized discrete Fourier transform applied in current space, is performed to determine how spectral degeneracy and side-bands creation limit the number of simultaneously controllable target modes. Finally, this thesis sets the foundations of experimental research in the particular subject of RMP at CRPP by proposing a physics-based design for a multi-purpose saddle coil system (SCS) for TCV, a coil system located and powered such as to create a helical magnetic perturbation. Using independent power supplies, the toroidal periodicity of this perturbation is tunable, allowing simultaneously ELM control, error field correction and vertical control. Other experimental applications, like resistive wall mode and rotation control, are also in view. In this thesis, the adequacy of two SCS designs, an in-vessel one and an ex-vessel one, is assessed with respect to the desired experimental applications. The current requirements and the system performances are also characterized. The conducting vessel wall is accounted for in a model used to determine the coupled response functions of the SCS, the screening of the magnetic perturbation by the wall, the induced voltages and currents during a plasma disruption and the maximal magnetic forces exerted on the SCS. A scaling of the SCS parameters with the number of coil turns is presented and the issue of coil heating and cooling is discussed.
329. Extremely Shaped Plasmas to Improve the Tokamak Concept
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Piras, Francesco, Moret, Jean-Marc, and Martin, Yves
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breakdown ,plasma physics ,magnetic diagnostics ,error field ,calibration ,edge physics ,snowflake ,doublet ,H-mode ,ELM ,TCV ,tokamak ,control ,nuclear fusion - Abstract
Energy is essential for human existence and our future depends on plentiful and accessible sources of energy. The world population is fast growing and the average energy used per capita increases. One of the greatest challenges for human beings is that of meeting the growing demand for energy in a responsible, equitable and sustainable way. The possibility to obtain energy by "fusing" light atoms addresses these needs. Nuclear fusion reactions are clean, safe and the amount of fuel present on Earth (hydrogen isotopes) is practically inexhaustible and well distributed. Nuclear fusion is a natural process that occurs in all active stars like our Sun. Since the first demonstration of a deuterium fusion reaction (Rutherford 1933), researchers worldwide have tried to replicate this process on Earth by building a thermonuclear fusion reactor. Nevertheless, the challenge posed by the construction of a nuclear fusion reactor is greater than the one presented earlier by the development of a fission reactor. During the IAEA Conference in Geneva in the early 1958, L.A.Artsimovich declared: "Plasma physics is very difficult. Worldwide collaboration is needed for progress" and E.Teller, at the same conference: "Fusion technology is very complex. It is almost impossible to build a fusion reactor in this century". They were right. The extremely high temperature and density necessary to fuse hydrogen isotopes makes it difficult indeed to create a successful fusion reactor. Even though the physics of the fusion reaction appears clear, we are still facing problems on the road towards bulding the "box" that can efficiently confine the hot gas in the state of plasma. The best results so far have been obtained confining a plasma with strong magnetic fields in a toroidal configuration ("tokamak"). The Centre de Recherches en Physique des Plasmas in Switzerland actively studies this promising configuration towards the development of a nuclear fusion reactor. The experimental activity of the Tokamak à Configuration Variable (TCV) mainly focuses on the research of optimized plasma shapes capable of improving the global performance and solve the technological challenges of a tokamak reactor. Several theoretical and experimental results show the importance of the plasma shape in tokamaks. The maximum value of β (an indicator of the confinement efficiency) is for example related to the ratio between the height and the width of the plasma. The plasma shape can also affect the power necessary to access improved confinement regimes, as well as the plasma stability. This thesis reports on a contribution towards the optimization of the tokamak plasma shape. In particular, it describes the theoretical and experimental studies carried out in the TCV tokamak on two innovative plasma shapes: the doublet shaped plasma and the snowflake divertor. Doublet shaped plasmas have been studied in the past by the General Atomics group. Since then, the development of new plasma diagnostics and the discovery of new confinement regimes have given new reasons for interest in this unusual configuration. TCV is the only tokamak worldwide theoretically able to establish and control this configuration. This thesis illustrates new motivations for creating doublet plasmas. The vertical stability of the configuration is studied using a rigid model and the results are compared with those obtained with the KINX MHD stability code. The best strategy for controlling a doublet on TCV is also investigated, and a possible setup of the TCV control system is suggested for the doublet configuration. Analyzing the possible scenarios for doublet creation, the most promising scenario consists of the creation of two independent plasmas, which are subsequently merged to establish a doublet. For this reason, particular attention needs to be devoted to the problem of the plasma start-up. In this thesis, a general analysis of the TCV ohmic and assisted with ECH plasma start-up is presented, and recent attempts to create a doublet plasma are reported. Since the magnetic field reconstruction at the breakdown time is important to better diagnose these plasmas, the entire magnetic system of TCV has been calibrated with an original technique, also described in the manuscript. The last part of this thesis is devoted to the snowflake divertor configuration. This innovative plasma shape has been proposed and theoretically studied by Dr. D.D.Ryutov from the Lawrence Livermore National Laboratory. In Ryutov's articles, this configuration was proposed to alleviate the problems of the plasma-wall interaction and possibly affect the plasma edge stability. The TCV tokamak was the first to report the creation and control of a snowflake configuration, and the candidate was the principal investigator of this work. These results are accordingly discussed in this thesis. Details are provided in particular on the strategy used to establish the configuration. An edge-localized mode (ELM) H-mode regime, supported by electron cyclotron heating, has been successfully established in a snowflake. This regime exhibits 2 to 3 times lower ELM frequency but only a 20%-30% increase in normalized ELM energy (ΔWELM/WP ) compared to an identically-shaped, conventional, single-null, diverted H-mode. Enhanced stability of mid- to high-toroidal-mode-number ideal modes is consistent with the different snowflake ELM phenomenology. Finally, the capability of the snowflake to redistribute the edge power on the additional strike points has been confirmed experimentally and is also reported in this thesis.
330. High-performance superconducting quantum processors via laser annealing of transmon qubits.
- Author
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Zhang EJ, Srinivasan S, Sundaresan N, Bogorin DF, Martin Y, Hertzberg JB, Timmerwilke J, Pritchett EJ, Yau JB, Wang C, Landers W, Lewandowski EP, Narasgond A, Rosenblatt S, Keefe GA, Lauer I, Rothwell MB, McClure DT, Dial OE, Orcutt JS, Brink M, and Chow JM
- Abstract
Scaling the number of qubits while maintaining high-fidelity quantum gates remains a key challenge for quantum computing. Presently, superconducting quantum processors with >50 qubits are actively available. For these systems, fixed-frequency transmons are attractive because of their long coherence and noise immunity. However, scaling fixed-frequency architectures proves challenging because of precise relative frequency requirements. Here, we use laser annealing to selectively tune transmon qubits into desired frequency patterns. Statistics over hundreds of annealed qubits demonstrate an empirical tuning precision of 18.5 MHz, with no measurable impact on qubit coherence. We quantify gate error statistics on a tuned 65-qubit processor, with median two-qubit gate fidelity of 98.7%. Baseline tuning statistics yield a frequency-equivalent resistance precision of 4.7 MHz, sufficient for high-yield scaling beyond 10
3 qubit levels. Moving forward, we anticipate selective laser annealing to play a central role in scaling fixed-frequency architectures.- Published
- 2022
- Full Text
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331. Effect of Wearing a Novel Electronic Wearable Device on Hand Hygiene Compliance Among Health Care Workers: A Stepped-Wedge Cluster Randomized Clinical Trial.
- Author
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Pires D, Gayet-Ageron A, Guitart C, Robert YA, Fankhauser C, Tartari E, Peters A, Tymurkaynak F, Fourquier S, Soule H, Beuchat R, Bellissimo-Rodrigues F, Martin Y, Zingg W, and Pittet D
- Subjects
- Adult, Age Factors, Female, Hand Hygiene, Humans, Male, Middle Aged, Nurses, Nursing Assistants, Physical Therapists, Quality Improvement, Random Allocation, Workload, Cross Infection prevention & control, Formative Feedback, Guideline Adherence, Hand Disinfection standards, Hand Sanitizers, Health Personnel, Wearable Electronic Devices
- Abstract
Importance: Hand hygiene (HH) is essential to prevent hospital-acquired infections., Objective: To determine whether providing real-time feedback on a simplified HH action improves compliance with the World Health Organization's "5 Moments" and the quality of the HH action., Design, Setting, and Participants: This open-label, cluster randomized, stepped-wedge clinical trial was conducted between June 1, 2017, and January 6, 2018 (with a follow-up in March 2018), in a geriatric hospital of the University of Geneva Hospitals, Switzerland. All 12 wards and 97 of 306 eligible health care workers (HCWs) volunteered to wear a novel electronic wearable device that delivered real-time feedback on duration of hand rubbing and application of a hand-sized customized volume of alcohol-based handrub (ABHR)., Interventions: This study had 3 sequential periods: baseline (no device), transition (device monitoring without feedback), and intervention (device monitoring and feedback). The start of the transition period was randomly allocated based on a computer-generated block randomization., Main Outcomes and Measures: The primary outcome was HH compliance, according to the direct observation method during intervention as compared with baseline. Secondary outcomes included the volume of ABHR and duration of hand rubbing measured by the device during intervention as compared with transition., Results: All wards and respective HCWs were evenly assigned to group 1 (26 participants), 2 (22 participants), 3 (25 participants), or 4 (24 participants). Twelve HCWs did not fully complete the intervention but were included in the analysis. During 759 observation sessions, 6878 HH opportunities were observed. HH compliance at intervention (62.9%; 95% CI, 61.1%-64.7%) was lower than at baseline (66.6%; 95% CI, 64.8%-68.4%). After adjusting for covariates, HH compliance was not different between periods (odds ratio, 1.03; 95% CI, 0.75-1.42; P = .85). Days since study onset (OR, 0.997; 95% CI, 0.994-0.998; P < .001), older age (OR, 0.97; 95% CI, 0.95-0.99; P = .015), and workload (OR, 0.29; 95% CI, 0.20-0.41; P < .001) were independently associated with reduced HH compliance. The median (interquartile range) volume of ABHR and duration of hand rubbing in transition and intervention increased from 1.12 (0.76-1.68) mL to 1.71 (1.01-2.76) mL and from 6.5 (4.5-10.5) seconds to 8 (4.5-15.5) seconds, respectively. There were no serious adverse events., Conclusions and Relevance: The use of this device did not change HH compliance, but increased the duration of hand rubbing and volume of ABHR used by HCWs., Trial Registration: isrctn.org Identifier: ISRCTN25430066.
- Published
- 2021
- Full Text
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332. Audiovisual speech segmentation in post-stroke aphasia: a pilot study.
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Basirat A, Allart É, Brunellière A, and Martin Y
- Subjects
- Aged, Aphasia psychology, Aphasia rehabilitation, Cognition Disorders psychology, Cognition Disorders rehabilitation, Comprehension, Cues, Female, Gestures, Humans, Male, Middle Aged, Neuropsychological Tests, Photic Stimulation, Pilot Projects, Psychomotor Performance, Aphasia etiology, Cognition Disorders etiology, Speech Perception, Stroke complications
- Abstract
Background : Stroke may cause sentence comprehension disorders. Speech segmentation, i.e. the ability to detect word boundaries while listening to continuous speech, is an initial step allowing the successful identification of words and the accurate understanding of meaning within sentences. It has received little attention in people with post-stroke aphasia (PWA). Objectives : Our goal was to study speech segmentation in PWA and examine the potential benefit of seeing the speakers' articulatory gestures while segmenting sentences. Methods : Fourteen PWA and twelve healthy controls participated in this pilot study. Performance was measured with a word-monitoring task. In the auditory-only modality, participants were presented with auditory-only stimuli while in the audiovisual modality, visual speech cues (i.e. speaker's articulatory gestures) accompanied the auditory input. The proportion of correct responses was calculated for each participant and each modality. Visual enhancement was then calculated in order to estimate the potential benefit of seeing the speaker's articulatory gestures. Results : Both in auditory-only and audiovisual modalities, PWA performed significantly less well than controls, who had 100% correct performance in both modalities. The performance of PWA was correlated with their phonological ability. Six PWA used the visual cues. Group level analysis performed on PWA did not show any reliable difference between the auditory-only and audiovisual modalities (median of visual enhancement = 7% [Q1 - Q3: -5 - 39]). Conclusion : Our findings show that speech segmentation disorder may exist in PWA. This points to the importance of assessing and training speech segmentation after stroke. Further studies should investigate the characteristics of PWA who use visual speech cues during sentence processing.
- Published
- 2019
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333. Should Alcohol-Based Handrub Use Be Customized to Healthcare Workers' Hand Size?
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Bellissimo-Rodrigues F, Soule H, Gayet-Ageron A, Martin Y, and Pittet D
- Subjects
- Colony Count, Microbial, Cross Infection prevention & control, Hand, Health Personnel, Hospitals, University, Humans, Linear Models, Switzerland, Anti-Infective Agents, Local pharmacology, Escherichia coli drug effects, Ethanol pharmacology, Hand Disinfection methods, Infection Control methods
- Abstract
We evaluated whether the volume of alcohol-based handrub used by healthcare workers affects the residual bacterial concentration on their hands according to hand size. Bacterial reduction was significantly lower for large hands compared with small hands, which suggests a need for customizing the volume of alcohol-based handrub for hand hygiene.
- Published
- 2016
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334. The perception of peripersonal space in right and left brain damage hemiplegic patients.
- Author
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Bartolo A, Carlier M, Hassaini S, Martin Y, and Coello Y
- Abstract
Peripersonal space, as opposed to extrapersonal space, is the space that contains reachable objects and in which multisensory and sensorimotor integration is enhanced. Thus, the perception of peripersonal space requires combining information on the spatial properties of the environment with information on the current capacity to act. In support of this, recent studies have provided converging evidences that perceiving objects in peripersonal space activates a neural network overlapping with that subtending voluntary motor action and motor imagery. Other studies have also underlined the dominant role of the right hemisphere (RH) in motor planning and of the left hemisphere (LH) in on-line motor guiding, respectively. In the present study, we investigated the effect of a right or left hemiplegia in the perception of peripersonal space. 16 hemiplegic patients with brain damage to the left (LH) or right (RH) hemisphere and eight matched healthy controls performed a color discrimination, a motor imagery and a reachability judgment task. Analyses of response times and accuracy revealed no variation among the three groups in the color discrimination task, suggesting the absence of any specific perceptual or decisional deficits in the patient groups. In contrast, the patient groups revealed longer response times in the motor imagery task when performed in reference to the hemiplegic arm (RH and LH) or to the healthy arm (RH). Moreover, RH group showed longer response times in the reachability judgment task, but only for stimuli located at the boundary of peripersonal space, which was furthermore significantly reduced in size. Considered together, these results confirm the crucial role of the motor system in motor imagery task and the perception of peripersonal space. They also revealed that RH damage has a more detrimental effect on reachability estimates, suggesting that motor planning processes contribute specifically to the perception of peripersonal space.
- Published
- 2014
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335. Bridging the gap between physicochemistry and interpretation prevalent in cell-surface interactions.
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Dubiel EA, Martin Y, and Vermette P
- Subjects
- Animals, Cell Adhesion, Cell Culture Techniques methods, Humans, Surface Properties, Biocompatible Materials chemistry, Biocompatible Materials metabolism, Cell Physiological Phenomena, Tissue Scaffolds chemistry
- Published
- 2011
- Full Text
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336. Outbreak of endophthalmitis after cataract surgery: the importance of the quality of the surgical wound.
- Author
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Hugonnet S, Dosso A, Dharan S, Martin Y, Herrero ML, Régnier C, and Pittet D
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- Aged, Aged, 80 and over, Endophthalmitis etiology, Equipment Failure, Female, Humans, Male, Postoperative Complications, Surgical Wound Infection etiology, Cataract Extraction adverse effects, Disease Outbreaks, Endophthalmitis epidemiology, Surgical Instruments adverse effects, Surgical Wound Infection epidemiology
- Abstract
Postoperative endophthalmitis is a rare but potentially devastating condition. We investigated an outbreak of 8 cases of endophthalmitis in patients who underwent phakectomy performed by a single surgeon from January through September 2004. The outbreak was traced to damaged surgical blades, and it highlights the importance of the quality of the surgical wound.
- Published
- 2006
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337. Bioreactors for tissue mass culture: design, characterization, and recent advances.
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Martin Y and Vermette P
- Subjects
- Animals, Cell Culture Techniques methods, Cell Culture Techniques trends, Cell Proliferation, Humans, Technology Assessment, Biomedical, Tissue Engineering methods, Tissue Engineering trends, Bioartificial Organs, Biocompatible Materials chemistry, Bioreactors, Cell Culture Techniques instrumentation, Tissue Engineering instrumentation
- Abstract
This paper reviews reports on three-dimensional mammalian tissue growth in bioreactors and the corresponding mammalian tissue growth requirements. The needs for nutrient and waste removal of several mammalian tissues are reviewed and compared with the environment of many reactors currently in use such as the continuous stirred tank, the hollow fiber, the Couette-Taylor, the airlift, and the rotating-wall reactors developed by NASA. Many studies conclude that oxygen supply appears to be one of the most important factors limiting tissue growth. Various correlations to describe oxygen mass transfer are presented and discussed with the aim to provide some guidance to design, construct, and test reactors for tissue mass culture. To obtain tissue thickness clinically valuable, dimensionless and other types of analysis tend to point out that diffusive transport will have to be matched with an important convection to bring sufficient oxygen molecular flux to the growing cells located within a tissue mass. As learned from solid-state fermentation and hairy root culture, during the growth of large biomass, heterogeneity (i.e., channeling, temperature gradients, non-uniform cell growth, transfer gradients, etc.) can cause some important problems and these should be addressed in tissue engineering as well. Reactors (along with the scaffolds) should be designed to minimize these issues. The role of the uterus, the reactor built by Nature, is examined, and the environment provided to a growing embryo is reported, yielding possible paths for further reactor developments. Finally, the importance of cell seeding methods is also addressed.
- Published
- 2005
- Full Text
- View/download PDF
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