Summary:The authors investigated concomitant lactate and glucose metabolism in primary neuronal cultures using 13 Cand 1 H-NMR spectroscopy. Neurons were incubated in a medium containing either [1- 13C]glucose and different unlabeled lactate concentrations, or unlabeled glucose and different [3-13 C]lactate concentrations. Overall, 13 C-NMR spectra of cellular extracts showed that more 13 C was incorporated into glutamate when lactate was the enriched substrate. Glutamate 13 C-enrichment was also found to be much higher in lactatelabeled than in glucose-labeled conditions. When glucose and lactate concentrations were identical (5.5 mmol/L), relative contributions of glucose and lactate to neuronal oxidative metabolism amounted to 21% and 79%, respectively. Results clearly indicate that when neurons are in the presence of both glucose and lactate, they preferentially use lactate as their main oxidative substrate. Key Words: Energy metabolismBrain-NMR spectroscopy-TCA cycle-MonocarboxylateGlutamate.

a b s t r a c tNeustonic microplastic and zooplankton abundance was determined in the North Western Mediterranean Sea during a summer cruise between July 9th and August 6th 2010, with a break between July 22th and 25th due to a strong wind event. Ninety percent of the 40 stations contained microplastic particles (size 0.3-5 mm) of various compositions: e.g., filaments, polystyrene, thin plastic films. An average concentration of 0.116 particles/m 2 was observed. The highest abundances (>0.36 particles/m 2 ) were observed in shelf stations.The neustonic plastic particles concentrations were 5 times higher before than after the strong wind event which increased the mixing and the vertical repartition of plastic particles in the upper layers of the water column. The values rise in the same order of magnitude than in the North Pacific Gyre. The average ratio between microplastics and mesozooplankton weights was 0.5 for the whole survey and might induce a potential confusion for zooplankton feeders.

Using "click chemistry" as an easy and versatile synthetic strategy to combine hyaluronan and polyglutamate blocks, we have prepared nanovesicles (polymersomes) that present a controlled size, excellent colloidal stability, and a high loading capacity for hydrophilic and hydrophobic drugs. The unique feature of our concept is the use of hyaluronan, a polysaccharide with known capacity for targeting cancer-related protein receptors, as the hydrophilic portion of a block copolymer system. The cytotoxicity and internalization mechanism of doxorubicin-loaded polymersomes have been evaluated in C6 glioma tumor cell lines. The dual purpose served by hyaluronan, as both a hydrophilic block critical to vesicle formation and a binding agent for biological targets, breaks new ground in terms of multifunctional nanomaterial design for drug delivery.