Monitoring of the primary drying of a lyophilization process in vials

An innovative and modular system (LyoMonitor) for monitoring the primary drying of a lyophilization process in vials is illustrated: it integrates some commercial devices (pressure gauges, moisture sensor and mass spectrometer), an innovative balance and a manometric temperature measurement system based on an improved algorithm (DPE) to estimate sublimating interface temperature and position, product temperature profile, heat and mass transfer coefficients. A soft-sensor using a multipoint wireless thermometer can also estimate the previous parameters in a large number of vials. The performances of the previous devices for the determination of the end of the primary drying are compared. Finally, all these sensors can be used for control purposes and for the optimization of the process recipe; the use of DPE in a control loop will be shown as an exampl

Developing smart control strategies for freeze-drying of lactic acid bacteria (communication orale)

International audienceno abstrac

Effect of controlled ice nucleation on primary drying stage and protein recovery in vials cooled in a modified freeze-dryer

International audienceThe freezing step influences lyophilization efficiency and protein stability. The main objective of this work was to investigate the impact on the primary drying stage of an ultrasound controlled ice nucleation technology, compared with usual freezing protocols. Lyophilization cycles involving different freezing protocols (applying a constant shelf cooling rate of 1°C/min or 0.2°C/min, putting vials on a precooled shelf, and controlling nucleation by ultrasounds or by addition of a nucleating agent) were performed in a prototype freeze-dryer. Three protective media including sucrose or maltodextrin and differing by their thermal properties and their ability to preserve a model protein (catalase) were used. The visual aspect of the lyophilized cake, residual water content, and enzymatic activity recovery of catalase were assessed after each lyophilization cycle and after 1 month of storage of the lyophilized product at 4°C and 25°C. The freezing protocols allowing increasing nucleation temperature (precooled shelf and controlled nucleation by using ultrasounds or a nucleating agent) induced a faster sublimation step and higher sublimation rate homogeneity. Whatever the composition of the protective medium, applying the ultrasound technology made it possible to decrease the sublimation time by 14%, compared with the freezing method involving a constant shelf cooling rate of 1°C/min. Concerning the enzyme activity recovery, the impact of the freezing protocol was observed only for the protective medium involving maltodextrin, a less effective protective agent than sucrose. Higher activity recovery results were obtained after storage when the ultrasound technology or the precooled shelf method was applied. Controlling ice nucleation during the freezing step of the lyophilization process improved the homogeneity of the sublimation rates, which will, in turn, reduce the intervial heterogeneity. The freeze-dryer prototype including the system of controlled nucleation by ultrasounds appears to be a promising tool in accelerating sublimation and improving intrabatch homogeneity. ©2009 American Society of Mechanical Engineer

Breinlia (Breinlia) jittapalapongi n. sp. (Nematoda: Filarioidea) from the Asian house rat Rattus tanezumi Temminck in Lao PDR

International audienceA new species of filarioid nematode of the genus Breinlia Yorke & Maplestone, 1926 (Nematoda: Filarioidea) is described from rodents in Lao PDR and according to its morphology, is placed in the subgenus Breinlia. Breinlia (Breinlia) jittapalapongi n. sp. occurs in the Asian house rat (Rattus tanezumi Temminck) and the Sikkim rat (Rattus andamanensis Blyth) and is reported from two localities (Luang Prabang and Champasak). The new species can be distinguished from all other congeners, which are mostly distributed in Australasia (twenty-two species), South East Asia (four species) and India (two species), by the following characters of the males: shape and size of gubernaculum, length of spicules, pattern of cloacal papillae and presence of sclerotised ring in the buccal capsule. This is the fifth species of Breinlia described from South East Asia

STRIDES: a 3.9 per cent measurement of the Hubble constant from the strong lens system DES J0408-5354

We present a blind time-delay cosmographic analysis for the lens system DES J0408−5354. This system is extraordinary for the presence of two sets of multiple images at different redshifts, which provide the opportunity to obtain more information at the cost of increased modelling complexity with respect to previously analysed systems. We perform detailed modelling of the mass distribution for this lens system using three band Hubble Space Telescope imaging. We combine the measured time delays, line-of-sight central velocity dispersion of the deflector, and statistically constrained external convergence with our lens models to estimate two cosmological distances. We measure the “effective” time-delay distance corresponding to the redshifts of the deflector and the lensed quasar D eff ∆t = 3382+146 −115 Mpc and the angular diameter distance to the deflector Dd = 1711+376 −280 Mpc, with covariance between the two distances. From these constraints on the cosmological distances, we infer the Hubble constant H0= 74.2 +2.7 −3.0 km s−1 Mpc−1 assuming a flat ΛCDM cosmology and a uniform prior for Ωm as Ωm ∼ U(0.05, 0.5). This measurement gives the most precise constraint on H0 to date from a single lens. Our measurement is consistent with that obtained from the previous sample of six lenses analysed by the H0 Lenses in COSMOGRAIL’s Wellspring (H0LiCOW) collaboration. It is also consistent with measurements of H0 based on the local distance ladder, reinforcing the tension with the inference from early Universe probes, for example, with 2.2σ discrepancy from the cosmic microwave background measurement