Development and qualification of 3 L scale-down model for large scale vaccine process on Vero cell culture using microcarriers.

Scale-down models (SDM) are pivotal tools for process understanding and improvement to accelerate the development of vaccines from laboratory research to global commercialization. In this study, a 3 L SDM representing a 50 L scale Vero cell culture process of a live-attenuated virus vaccine using microcarriers was developed and qualified based on the constant impeller power per volume principle. Both multivariate data analysis (MVDA) and the traditional univariate data analysis showed comparable and equivalent cell growth, metabolic activity, and product quality results across scales.

Pushing the limits of flash photolysis to unravel the secrets of biological electron and proton transfer.

Time-resolved absorption spectroscopy is a powerful tool to unravel biological functions and has been a key technology for elucidating the working of electron transfer chains in photosynthesis or photorepair of UV-damaged DNA. Both of these areas have seen important contributions from laboratories all over the world, not the least of them stemming from the ingenious technical advances described by Klaus Brettel, first at the Technical University of Berlin (Germany), and later at the Atomic Energy Agency in Saclay (France). Now, after more than forty years of tireless scientific activity, Klaus is approaching retirement and this collection gathers together tributes in the form of scientific contributions from colleagues along the way, covering a spectrum of topics as diverse as photosynthesis, light-induced DNA repair, electron and proton transfer in light signalling, flavin based photo-enzymology, fluorescent marker photophysics, synthetic models and modelisation, delicate sample transient absorption spectroscopy.

Tribute in memory of Jacques Breton (1942-2018).

Jacques Breton spent his 39 years of professional life at Saclay, a center of the French Atomic Energy Commission. He studied photosynthesis with various advanced biophysical tools, often developed by himself and his numerous coworkers, obtaining a large number of new information on the structure and the functioning of antenna and of reaction centers of plants and bacteria: excitation migration in the antenna, orientation of molecules, rate of primary reactions, binding of pigments and electron transfer cofactors. Although it is much too short to illustrate his impressive work, we hope that this contribution will help maintaining the souvenir of Jacques Breton as an active and enthusiastic person, full of qualities, devoted to research and to his family as well.

High-global warming potential F-gas emissions in California: comparison of ambient-based versus inventory-based emission estimates, and implications of refined estimates.

To provide information for greenhouse gas reduction policies, the California Air Resources Board (CARB) inventories annual emissions of high-global-warming potential (GWP) fluorinated gases, the fastest growing sector of greenhouse gas (GHG) emissions globally. Baseline 2008 F-gas emissions estimates for selected chlorofluorocarbons (CFC-12), hydrochlorofluorocarbons (HCFC-22), and hydrofluorocarbons (HFC-134a) made with an inventory-based methodology were compared to emissions estimates made by ambient-based measurements. Significant discrepancies were found, with the inventory-based emissions methodology resulting in a systematic 42% under-estimation of CFC-12 emissions from older refrigeration equipment and older vehicles, and a systematic 114% overestimation of emissions for HFC-134a, a refrigerant substitute for phased-out CFCs.