No abstract

Development of high energy density hybrid electrode based on rGO–PMo12 for all-solid state supercapacitors along with actual demonstration of lighting of thirty one LEDs (NEO).

Tunneling nanotubes (TnTs) are thin channels that temporally connect nearby cells allowing the cell-to-cell trafficking of biomolecules and organelles. The presence or absence of TnTs in human neoplasms and the mechanisms of TnT assembly remains largely unexplored. In this study, we have identified TnTs in tumor cells derived from squamous cell carcinomas (SCC) cultured under bi-dimensional and tri-dimensional conditions and also in human SCC tissues. Our study demonstrates that TnTs are not specific of epithelial or mesenchymal phenotypes and allow the trafficking of endosomal/lysosomal vesicles, mitochondria, and autophagosomes between both types of cells. We have identified focal adhesion kinase (FAK) as a key molecule required for TnT assembly via a mechanism involving the MMP-2 metalloprotease. We have also found that the FAK inhibitor PF-562271, which is currently in clinical development for cancer treatment, impairs TnT formation. Finally, FAK-deficient cells transfer lysosomes/autophagosomes to FAK-proficient cells via TnTs which may represent a novel mechanism to adapt to the stress elicited by impaired FAK signaling. Collectively, our results strongly suggest a link between FAK, MMP-2, and TnT, and unveil new vulnerabilities that can be exploited to efficiently eradicate cancer cells.

Three-dimensionally ordered macroporous (3DOM) LiMn 2 O 4 spinel was prepared by a colloidal templating process. An opal structure consisting of monodispersed poly[styrene-co-methacrilic acid] beads (380 nm in diameter) was used as a template. After infiltration of Li and Mn nitrates, the assembly was calcined in air at temperatures between 500 and 700 °C. Chemical processes were studied by means of thermal analysis, X-ray diffraction (XRD), and solid-state nuclear magnetic resonance (NMR). Morphological and microstructural characterizations were carried out by scanning and transmission electron microscopy (SEM, TEM) and by gas adsorption volumetry. Despite the simple preparation procedure, several steps are detected, which prove to be critical for the successful formation of high-quality 3DOM materials. Optimization of the preparation conditions gave extended macroporous networks with relatively smooth nanocrystalline spinel walls and a surface area of 24 m 2 /g. Porosity results from three ranges of pores: (1) the macroporous sublattice (replica of the opal lattice), (2) the pores formed after mineralization of the tetrahedral and octahedral holes of the template, and (3) the porosity from the nanocrystallites forming roughened macroporous walls. Films of 3DOM LiMn 2 O 4 were prepared on conductive substrates and used as electrodes, showing fast and reversible lithium deinsertion over a large number of cycles without suffering significant morphological or electrochemical degradation.

The dynamic structure factor for a dense gas He/Ne mixture is calculated by molecular dynamics.At length scales within the realm of hydrodynamics, k~0.03 A ', the spectrum shows a well-resolved Rayleigh-Brillouin triplet, evidencing the presence of sound-wave excitations. For intermediate wave vectors, the partial spectra apart from showing a broadening of the inelastic peaks unveil the presence of two additional modes with phase velocities below and above hydrodynamic sound. The present results cover a broad range of wave vectors, which cannot, at present, be reached by experimental techniques, and where present theoretical approaches are not well established. PACS numbers: 61.25.Bi, 61.20.Ja, 78.35.+c The spectrum of the light scattered (LS) by a Iluid composed of a binary mixture is well understood on linearized hydrodynamics grounds [1], and the line shape

A recent experiment ͓Phys. Rev. Lett. 80, 2141 ͑1998͔͒ showed heavily damped excitations in molten Li 4 Pb, within kinematic scales well beyond those of hydrodynamic sound. These findings pointed to the presence of short-lived out-of-phase atomic motions as the underlying microscopic phenomenon. A series of computer molecular dynamics studies are performed to investigate the details of the atomic motions. From an analysis of the simulated structure factors for molten Li 4 Pb, as well as by a comparison with those of liquid Li under different thermodynamic conditions, it is found that the high-frequency excitation found in the alloy shows characteristics remarkably different from those of pure Li. The relative phases of the atoms partaking in such motions, as well as the remarkably short excitation lifetimes, portray it as a fairly localized mode, with a frequency dependent polarization. ͓S1063-651X͑98͒07210-9͔PACS number͑s͒: 61.20. Lc, 61.25.Mv, 61.12.Ϫq

We analyze in detail the relationship between pore size distribution and discharge capacity for cathodes in ionic liquid-based Li/O 2 batteries at room temperature (RT) and 60 °C. We used several porous carbons with similar composition and apparent surface area but with pore distribution peaks in different points of the meso/macroporous region. The porous structure of carbons caused a significant influence on the discharge specific capacity. However, no obvious correlations between specific capacity and surface area or total pore volumes were observed. Carbons with high mesopore volumes and a predominant pore size of 20−40 nm exhibited the highest specific capacities. When temperature rises from room temperature to 60 °C, discharge capacity increases by a factor higher than two, with the smallest pores providing the highest increases. A model is introduced to empirically correlate capacity with pore size distribution. This model assumes that during electrochemical discharge the pore walls are uniformly coated in their thickness but that pores below a threshold size value do not participate at all to the capacity. Our model can account for the effects of pore size distribution using a discharge layer thickness of a few nanometers and with threshold values of excluded pore sizes, of 12 nm at RT and 10 nm at 60 °C. The model also allowed the estimation of the penetration depth of the discharge reaction on the electrode thickness and indicates that its increase is the main factor justifying the increase of capacity when temperature is increased.

The dynamics of crystalline glycerol are studied by means of Raman spectroscopy and lattice dynamics calculations employing a semiflexible model to represent the low-lying molecular vibrations. The latter is validated against structural, thermodynamic, and spectroscopic data. The results serve to set an absolute frequency scale for glassy glycerol, which is also studied by Raman and incoherent inelastic-neutron scattering. Some implications of the present findings regarding ensuing discussions on glassy dynamics are finally commented on.