Measuring the orientation of a single CdSe/CdS nanocrystal at the end of a near-field tip for the realization of a versatile active SNOM probe.

The orientation of a CdSe/CdS nanocrystal attached at the end of a scanning near field optical microscope (SNOM) tip is analyzed by its coupling with a flat gold layer. The Purcell factors for a set of distances to the gold surface are measured after a NC is caught by a SNOM tip. These measurements are compared with the modeling of the emission of a 2D dipole on a gold layer taking into account the layer of polymer serving as a glue for the NC.

Non-injurious neonatal hypoxia confers resistance to brain senescence in aged male rats.

Whereas brief acute or intermittent episodes of hypoxia have been shown to exert a protective role in the central nervous system and to stimulate neurogenesis, other studies suggest that early hypoxia may constitute a risk factor that influences the future development of mental disorders. We therefore investigated the effects of a neonatal "conditioning-like" hypoxia (100% N₂, 5 min) on the brain and the cognitive outcomes of rats until 720 days of age (physiologic senescence). We confirmed that such a short hypoxia led to brain neurogenesis within the ensuing weeks, along with reduced apoptosis in the hippocampus involving activation of Erk1/2 and repression of p38 and death-associated protein (DAP) kinase.

Conditioning-like brief neonatal hypoxia improves cognitive function and brain tissue properties with marked gender dimorphism in adult rats.

Although recent studies have documented compensatory generation of neurons in adult brains in response to various insults, a noninjurious short episode of hypoxia in rat neonates has been shown to trigger neurogenesis within the ensuing weeks, without apparent brain lesions. Very little is known of the long-term consequences. We therefore investigated the effects of such a conditioning-like hypoxia (100% N(2), 5 min) on the brain and the cognitive outcomes of rats at 40 to 100 days of age.