Purpose Malignant brain tumors are characterized by extensive infiltration into the normal brain tissue. Tumor migration is a complicated process which results from the interplay of a number of mechanisms, and the extent to which anatomic structure determined the migration pattern has not been extensively addressed. In the present study, we labeled C6 glioma cells with iron oxide nanoparticles and monitored the fate of the cells in vivo with magnetic resonance imaging (MRI). Procedures C6 glioma cells were labeled with ferumoxide–poly-L-lysine complexes and their migration in the brains of rats tracked by T2-weighted MRI. The same amount of iron-laden cells were implanted into the caudate nucleus (CN) and at the vicinity of anterior commissure (AC), respectively, and MRI was performed during the course of 20-day monitoring period to track tumor growth and migration. Results A clear tendency of tumor migration along the white matter fiber tracts was observed in the AC group, which is consistent with the previous reports; by contrast, tumor expanded to but remained confined within the boundary of right hemisphere in the CN group. Conclusion We successfully demonstrated the ability of MRI to investigate the impact of anatomical structure on the glioma migration pathway in vivo.

Diogenites are a group of meteorites that are derived from the interior of the largest protoplanet Vesta. They provide a unique opportunity to understanding together the internal structure and dynamic evolution of this protoplanet. Northwest Africa (NWA) 8321 was suggested to be an unbrecciated noritic diogenite meteorite, which is confirmed by our oxygen and chromium isotopic data. Here, we find that olivine in this sample has been partly replaced by orthopyroxene, troilite, and minor metal. The replacement texture of olivine is unambiguous evidence of sulfur-involved metasomatism in the interior of Vesta. The presence of such replacement texture suggests that in NWA 8321, the olivine should be of xenolith origin while the noritic diogenite was derived from partial melting of pre-existing rocks and had crystallized in the interior of Vesta. The post-Rheasilvia craters in the northpolar region on Vesta could be the potential source for NWA 8321.

We report a detailed study of magnetic and transport properties in perovskite manganites Nd0.55Sr0.45Mn1−xGaxO3 (0.00⩽x⩽0.20). The Ga substitution induces the B-site disorder together with a distinct suppression of the metal-insulator transition and ferromagnetic-paramagnetic transition. Due to an appearance of inhomogeneous magnetic clusters, the Griffiths-like phase is observed in 0.08⩽x⩽0.10 compounds. Meanwhile, with the increase of Ga concentration, the carriers self-trap into magnetic polarons. Because the oxygen sublattice distortion causes the variation of the phonon density of state, an additional Raman vibrative mode appears in the system.