Search results for "FAS"
showing 10 items of 2015 documents
Use of functional genes to quantify denitrifiers in the environment.
2006
During the last decade, application of molecular methods using cultivation-independent approaches has provided new insights into the composition and structure of denitrifying communities in various environments. However, little is known about their abundance, and quantification is still performed using cultivation-based approaches, which are not only biased by the inability to cultivate of many micro-organisms but also fastidious and time-consuming. Two types of cultivation-independent approaches have recently been developed to quantify denitrifiers. The first type, which is based on the hybridization technique, comprises the use of Southern hybridization and DNA arrays. The second type, ba…
Advances in detection of fastidious bacteria: From microscopic observation to molecular biosensors
2019
Abstract Identification of pathogens and diagnosis of infections are important health challenges, especially in the case of fastidious bacteria which are those difficult-to-grow. A fastidious organism is any organism that has a complex nutritional requirement. Additionally, a fastidious microorganism will only grow when specific nutrients are included in the culture medium. These bacteria can cause serious diseases whose detection and monitoring is critical in many cases. The oldest detection methods are based on simple microscopy observation and staining, after culture on selective growth media, but often do not provide a clear answer. Some new molecular approaches, such as DNA-based seque…
1443Safety of red yeast rice supplementation: a systematic review and meta-analysis of randomized controlled trials
2019
Abstract Background Recently, concerns regarding the safety of red yeast rice (RYR) have been raised after the publication of some case reports claiming toxicity. Purpose Since the previous meta-analyses on the effects of RYR were mainly focused on its efficacy to improve the lipid profile and other cardiovascular parameters, we carried out a meta-analysis on safety data derived from the available randomized controlled clinical trials (RCTs). Methods Primary outcomes were musculoskeletal disorders (MuD). Secondary outcomes were non-musculoskeletal adverse events (Non-MuD) and serious adverse events (SAE). Subgroups analyses were carried out considering the intervention (RYR alone or in asso…
Ultrafast ionization and rotational dynamics of molecules in strong laser fields
2021
The investigation of ultrafast molecular dynamics is of great importance towards the understanding of a variety of natural phenomena in physical and chemical sciences. With the rapid development of femtosecond laser systems and precision detection technologies, it is possible now to visualize and steer the motion of molecules in matter as well as the ultrafast dynamics of electrons and nuclei in molecules on a microscopic timescale. When a molecule is exposed to a strong laser field, its electrons can be freed or excited, which often triggers a rapid dissociation of the system, in which the released electrons and nuclei exhibit a strong correlation, while the electronic motion on attosecond…
Amplifier similariton fiber laser with nonlinear spectral compression
2012
International audience; We propose a new concept of a fiber laser architecture supporting self-similar pulse evolution in the amplifier and nonlinear spectral pulse compression in the passive fiber. The latter process allows for transform-limited picosecond pulse generation, and improves the laser's power efficiency by preventing strong spectral filtering from being highly dissipative. Aside from laser technology, the proposed scheme opens new possibilities for studying nonlinear dynamical processes. As an example, we demonstrate a clear period-doubling route to chaos in such nonlinear laser system.
Development of ultra-fast thulium-doped fiber lasers - Prospects for 2μm-nanophotonics.
2021
Developing highly coherent pulsed sources around the 2 µm wavelengthhas been a particularly dynamic field of research in the last couples of years,due to its numerous applications. In optical telecommunication, the wavelength rangearound 2 µm is one of the most promising solutions to increase the transmission capacitypast the current technological bottleneck. In this context, passively mode-lockedfiber lasers appear as a high potential solution for cheap laser sources, due to their veryhigh coherence and intrinsic compatibility with telecommunication systems.Passively mode-locked fiber lasers at 1,55 µm and their ultrafast dynamics is oneof the specialty of the ICB laboratory, and the aim i…
Le financement de l'éducation (Dossier)
2014
L'auteur est coordinateur du dossier; International audience; La seconde moitié du vingtième siècle a été marquée, partout dans le monde, par un développement considérable du secteur éducatif. Cette évolution concerne tous les niveaux d'enseignement, du primaire au supérieur, et fait peser une lourde charge sur les budgets nationaux. Tous les pays mettent aujourd'hui en ouvre des réformes spécifiques du financement de l'éducation, afin d'accompagner la croissance des effectifs, d'améliorer les résultats et de s'adapter aux nouvelles exigences de la société. Ce numéro 65 de la Revue internationale d'éducation de Sèvres propose un éclairage sur les politiques menées, durant les dernières déce…
Financement et régulation des systèmes éducatifs : innovations et évolution du rôle de l'État
2014
International audience; La seconde moitié du vingtième siècle a été marquée, partout dans le monde, par un développement considérable du secteur éducatif. Cette évolution concerne tous les niveaux d'enseignement, du primaire au supérieur, et fait peser une lourde charge sur les budgets nationaux. Tous les pays mettent aujourd'hui en ouvre des réformes spécifiques du financement de l'éducation, afin d'accompagner la croissance des effectifs, d'améliorer les résultats et de s'adapter aux nouvelles exigences de la société. Ce numéro 65 de la Revue internationale d'éducation de Sèvres propose un éclairage sur les politiques menées, durant les dernières décennies, pour maintenir ou accroître les…
Cardiovascular disease burden from ambient air pollution in Europe reassessed using novel hazard ratio functions
2019
Abstract Aims Ambient air pollution is a major health risk, leading to respiratory and cardiovascular mortality. A recent Global Exposure Mortality Model, based on an unmatched number of cohort studies in many countries, provides new hazard ratio functions, calling for re-evaluation of the disease burden. Accordingly, we estimated excess cardiovascular mortality attributed to air pollution in Europe. Methods and results The new hazard ratio functions have been combined with ambient air pollution exposure data to estimate the impacts in Europe and the 28 countries of the European Union (EU-28). The annual excess mortality rate from ambient air pollution in Europe is 790 000 [95% confidence i…
High Yield Ultrafast Intramolecular Singlet Exciton Fission in a Quinoidal Bithiophene
2015
We report the process of singlet exciton fission with high-yield upon photoexcitation of a quinoidal thiophene molecule. Efficient ultrafast triplet photogeneration and its yield are determined by photoinduced triplet-triplet absorption, flash photolysis triplet lifetime measurements, as well as by femtosecond time-resolved transient absorption and fluorescence methods. These experiments show that optically excited quinoidal bithiophene molecule undergoes ultrafast formation of the triplet-like state with the lifetime ∼57 μs. CASPT2 and RAS-SF calculations have been performed to support the experimental findings. To date, high singlet fission rates have been reported for crystalline and pol…