The invention relates to a wire stub antenna for transmitting a sequence of radio-frequency (RF) magnetic field pulses as part of a nuclear magnetic resonance (NMR) spectroscopy and/or imaging method, said wire stub antenna comprising a plurality of strands extending at least partially in a direction Z in an orthogonal reference system having an axis z defined by direction Z, said strands being disposed such that the currents passing through the strands of each antenna have the same intensity at the same position along axis z.

The world is running out of fossil fuels and the products of their burning in air (mostly CO2) have already impacted global climate. Therefore, we still need a lot effort to search how to convert the global energy economy towards cleaner and renewable fuels (like hydrogen), in particular, for mobile applications. It is clear now, that to efficiently store hydrogen at ambient temperature and not too high pressures, we need to develop hydrogen sorbent and optimize simultaneously both its specific surface and adsorption energy. In this project we propose to explore the potential effectiveness of arc-discharge procedure to synthetize nanoporous, carbon based sorbents with characteristics required in vehicular applications. The technique was successfully used in the past to synthetize fullerenes and nanotubes. Therefore we have assumed that we can adjust the synthesis parameters to prepare other graphene-based structures, with a variety graphene fragment sizes, forms, and interconnections between them. In addition, arc-discharge technique provides a relatively easy way to incorporate heteroatoms into pure carbon structures.The first characterizations of boron-substituted carbons obtained by this method are promising: the energy of hydrogen adsorption is the highest ever observed experimentally in carbon-based sorbents. However, the specific surface is relatively low, ~ 200 m2/g, suggesting that the samples need to be activated to increase their accessible for adsorption surface and, in consequence, their capacity to store hydrogen.

THREE-DIMENSIONAL VISUALIZATION OF THE INTERNAL ARRANGEMENT OF ONCHOCERCAL (ONCHOCERCA VOLVULUS) NODULES USING HIGH-RESOLUTION MAGNETIC RESONANCE IMAGING

Central nervous system (CNS) injury has been observed to lead to microglia activation and monocytes infiltration at the lesion site. Ex vivo diffusion magnetic resonance imaging (diffusion MRI or DWI) allows detailed examination of CNS tissues, and recent advances in clearing procedures allow detailed imaging of fluorescent-labeled cells at high resolution. No study has yet combined ex vivo diffusion MRI and clearing procedures to establish a possible link between microglia/monocytes response and diffusion coefficient in the context of spinal cord injury (SCI). We carried out ex vivo MRI of the spinal cord at different time-points after spinal cord transection followed by tetrahydrofuran based clearing and examined the density and morphology of microglia/monocytes using two-photon microscopy. Quantitative analysis revealed an early marked increase in microglial/monocytes density that is associated with an increase in the extension of the lesion measured using diffusion MRI. Morphological examination of microglia/monocytes somata at the lesion site revealed a significant increase in their surface area and volume as early as 72 hours post-injury. Time-course analysis showed differential microglial/monocytes response rostral and caudal to the lesion site. Microglia/monocytes showed a decrease in reactivity over time caudal to the lesion site, but an increase was observed rostrally. Direct comparison of microglia/monocytes morphology, obtained through multiphoton, and the longitudinal apparent diffusion coefficient (ADC), measured with diffusion MRI, highlighted that axonal integrity does not correlate with the density of microglia/monocytes or their somata morphology. We emphasize that differential microglial/monocytes reactivity rostral and caudal to the lesion site may thus coincide, at least partially, with reported temporal differences in debris clearance. Our study demonstrates that the combination of ex vivo diffusion MRI and two-photon microscopy may be used to follow structural tissue alteration. Lesion extension coincides with microglia/monocytes density; however, a direct relationship between ADC and microglia/monocytes density and morphology was not observed. We highlighted a differential rostro-caudal microglia/monocytes reactivity that may correspond to a temporal difference in debris clearance and axonal integrity. Thus, potential therapeutic strategies targeting microglia/monocytes after SCI may need to be adjusted not only with the time after injury but also relative to the location to the lesion site.