5 nm structures produced by direct laser writing.

Here we present a new approach to overcome the optical diffraction limit by using novel materials. In the paper, we report experimental results obtained by high-resolution transmission electron microscopy (HRTEM) and optical absorption spectroscopy, for a fluorescent photosensitive glass-ceramic containing rare-earth ions such as samarium (Sm). Using a home built dynamic tester, with a low power laser, we recorded nanostructures having 5 nm line widths. In the line structure, measurements reveal the presence of silver nanocrystals with few nanometre sizes. HRTEM shows that there is a random orientation of the nanocrystals. A writing mechanism with three steps is proposed.

Efficient uptake and retention of iron oxide-based nanoparticles in HeLa cells leads to an effective intracellular delivery of doxorubicin.

The purpose of this study was to construct and characterize iron oxide nanoparticles (IONPCO) for intracellular delivery of the anthracycline doxorubicin (DOX; IONPDOX) in order to induce tumor cell inactivation. More than 80% of the loaded drug was released from IONPDOX within 24 h (100% at 70 h). Efficient internalization of IONPDOX and IONPCO in HeLa cells occurred through pino- and endocytosis, with both IONP accumulating in a perinuclear pattern. IONPCO were biocompatible with maximum 27.9% ± 6.1% reduction in proliferation 96 h after treatment with up to 200 µg/mL IONPCO. Treatment with IONPDOX resulted in a concentration- and time-dependent decrease in cell proliferation (IC50 = 27.5 ± 12.0 µg/mL after 96 h) and a reduced clonogenic survival (surviving fraction, SF = 0.56 ± 0.14; versus IONPCO (SF = 1.07 ± 0.38)). Both IONP constructs were efficiently internalized and retained in the cells, and IONPDOX efficiently delivered DOX resulting in increased cell death vs IONPCO.

Ba(Zn1/3Ta2/3)O ceramics for microwave and millimeter-wave applications.

The Ba(Zn(1/3)Ta(2/3))O(3) (BZT) ceramic samples were prepared by solid-state reaction and sintered in the range 1550-1650 degrees C for 2 h. Several methods--X-ray diffraction (XRD) and scanning electron microscopy (SEM)--were used for structural and morphological characterization. The unit cell distortion and the presence of the secondary phase content were studied by XRD. A long-range order with a 2:1 ratio of Ta and Zn cations on the octahedral positions of the perovskite structure was noticed with the increase of the sintering temperature. SEM investigations revealed polyhedral well-faceted grains and large grain size distribution. The dielectric properties in the microwave range were measured at room temperature and at 1 kHz on a large temperature interval (+/-150 degrees C). The dielectric parameters were correlated with morphological and structural properties. Ceramic samples were annealed at 1410 degrees C for 30 h to improve the microwave properties. The dielectric constant of BZT samples measured at 6 GHz and at 1 kHz was between 27 and 28 on the whole temperature range, that is, typical values for BZT material. The temperature coefficient of the resonance frequency at 6 GHz exhibits positive values less than 6 ppm/degrees C.