582 research outputs found

    Effet magnéto-optique et optique des couches minces à base de ferrite de cobalt

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    Cette étude a pour but la mesure des effets magnéto-optiques (rotation Faraday) en fonction du champ magnétique appliqué et en fonction de la longueur d’onde, ainsi que la mesure de la transmittance (effet optique) des couches minces à base de ferrite de cobalt. Les résultats montrent une forte rotation Faraday spécifique avec des cycles d'hystérésis et des spectres de transmittance d'une bonne transparence dans la gamme Télécom (≈1550 nm).Mots-clés: ferrite de cobalt, sol-gel, couches minces, rotation Faraday, transmittance. Magneto-optical effect and optical thin films cobalt ferriteThis study was designed to measure the magneto-optical effect (Faraday rotation) according to the applied magnetic field and a function of the wavelength and the transmittance measurement (optical effect) thin film based on cobalt ferrite. The results show a high specific Faraday rotation with hysteresis cycles and transmittance spectra of a good transparency in the range Telecom (≈1550 nm).Keywords: cobalt ferrite, sol-gel thin films, Faraday rotation, transmittance

    A new Robertsonian translocation in Holstein-Friesian cattle

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    A new Robertsonian translocation was found in a cow of the Holstein-Friesian breed. GTG-banding allowed us to elucidate the anomaly as a centric fusion between chromosomes 19 and 21. CBG-banding demonstrated that the translocated chromosome was dicentric. Cytogenetic investigation of the relatives of the translocated animal revealed two other carriers.Une nouvelle translocation robertsonienne a été mise en évidence chez une vache de race Holstein. La coloration en bandes GTG nous a permis d’identifier les chromosomes impliqués dans la translocation. Il s’agit des chromosomes 19 et 21. La coloration en bandes CBG montre que le chromosome transloqué est dicentrique. Une analyse cytogénétique des apparentés de l’animal porteur a permis de mettre en évidence aux autres animaux porteurs

    Etude des propriétés magnéto-optiques des couches minces à base de ferrite de cobalt obtenues par voie sol-gel

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    Ce travail est consacré à l'étude des propriétés magnéto-optiques (rotation Faraday) de couches minces à base de ferrite de cobalt obtenues par voie sol-gel. La contribution de la méthode sol-gel utilisée est très importante et cela permet d’obtenir des couches minces ayant une bonne qualité optique. Cette démarche nécessite juste l’utilisation de liquides magnétiques ou ferro fluides, de précurseurs de silice (pas cher) et d’un substrat de verre. Le but est d’obtenir des couches minces et étudier leurs propriétés magnéto-optiques. Les courbes obtenues à la longueur d’onde de 820 nm présentent des cycles d’hystérésis avec des rotations rémanentes de 40, 60 et 81°/cm. Ces résultats présentent une excellente rotation Faraday de 212, 318 et 340°/cm à la longueur d’onde de 820 nm. Ceci montre la forte potentialité de la matrice sol-gel dopée.Mots-clés: nanoparticules magnétiques, ferrite de cobalt, sol-gel, couches minces, rotation Faraday. Study of themagneto-optical properties of thin films cobalt ferrite obtainedby the sol-gel This work is devoted to the study of magneto-optical (Faraday rotation) of thin cobalt ferrite layers obtained by sol-gel. The contribution of the sol-gel method is very important and it allows obtaining thin film shaving a good optical quality. This requires only the use of magnetic fluids or ferro fluids, silica precursors (cheap) and a glass substrate. The goal is to obtain thin layers and study their magneto-optical properties. The curves obtained for the wave length of 820 nm have hysteresis loops with retentive rotations of 40, 60 and 81°/ cm. These results show excellentFaradayrotation 212, 318 and 340°/cm ata wave length of 820 nm. This shows the high potential of the doped sol-gel matrix.Keywords: agnetic nanoparticles, cobalt ferrite, sol-gel, thin films, Faraday rotation

    Improved care of acute exacerbation of chronic obstructive pulmonary disease in two academic emergency departments

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    Background: Although several chronic obstructive pulmonary disease (COPD) practice guidelines have been published, there is sparse data on the actual emergency department (ED) management of acute exacerbation of COPD (AECOPD). Aims: Our objectives were to examine concordance of ED care of AECOPD in older patients with guideline recommendations and to evaluate whether concordance has improved over time in two academic EDs. Methods: Data were obtained from two cohort studies on AECOPD performed in two academic EDs during two different time periods, 2000 and 2005–2006. Both studies included ED patients, aged 55 and older, who presented with AECOPD, and cases were confirmed by emergency physicians. Data on ED management and disposition were obtained from chart review for both cohorts. Results: The analysis included 272 patients: 72 in the 2000 database and 200 in the 2005–2006 database. The mean age of the patients was 72 years; 50% were women and 80% white. In 2005–2006, overall concordance with guideline recommendations was high (for chest radiography, pulse oximetry, bronchodilators, all ≥ 90%), except for arterial blood gas testing (7% among the admitted) and discharge medication with systemic corticosteroids (42%). Compared to the 2000 data, the use of systemic corticosteroids in the ED improved from 53 to 77% [absolute improvement: 24%, 95% confidence interval (CI): 11–37%], and the use of antibiotics among the patients with respiratory infection symptoms improved from 56 to 78% (absolute improvement: 22%, 95% CI: 6–38%). Conclusions: Overall concordance with guideline-recommended care for AECOPD was high in two academic EDs, and some emergency treatments have improved over time
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