Roberto Eggenhöffner

Comments on some recent phenomenological potentials for the alkali halide crystals

Abstract Some comments are presented on three phenomenological potentials for the alkali halide crystals proposed in recent years by Narayan and Ramaseshan, by Woodcock, and by Romano, Margheritis and Sinistri. In the context a brief comment is made on the van der Waals coefficients reported by Hajj.

Comparative study of recent phenomenological potentials for the NaCl-type alkali halides derived from elastic and dielectric data

Abstract A comparative study is presented of various phenomenological potentials for the NaCl-type alkali halides-based on elastic and dielectric data and on a “combination” of the Born model with a deformable ion mode-reported in recent years by Catlow, Diller and Norgett, by Corish, Parker and Jacobs, by Sangster et al . and by Hardy and Karo. First a critical analysis is made of the models adopted by the various AA and of the procedures to determine the pertinent parameters, emphasizing the different, often crude approximations used and the thermodynamic inconsistencies present in them. The quality of the fits achieved, and of the predictions made with the different models is then discussed. Finally, one compares directly the resulting effective pair potentials for the short-range interactions cation-anion, anion-anion and cation-cation, as well as the various types of parameters (specifically the potential parameters (Born repulsive parameters and van der Waals coefficients) and the shell-model parameters). One finds that the effective short-range potentials for each pair interaction in a given salt reported by the various AA-taken as a whole-have a sizeable indeterminacy, due both to the Born repulsive and vdW contributions.

Transarterial radioembolization for hepatocellular carcinoma: a review

Hepatocellular carcinoma (HCC) is the most common type of liver cancer and is the second cause of death due to malignancy in the world. The treatment of HCC is complex and includes potentially curative and palliative approaches. However, both curative and palliative treatments for HCC are often associated with a not-completely favorable safety/efficacy ratio. Therefore, other treatment options appear necessary in clinical practice. Transarterial radioembolization has shown a promising efficacy in terms of disease control and is associated with a good safety profile. This review discusses the use of transarterial radioembolization in HCC, with a focus on the clinical aspects of this therapeutic strategy.

Chemical pressure effects and valence fluctuations in Yb0.6Ca0.4Al2 and YbAl2 alloys: A photoemission investigation

Abstract We present angle integrated X-ray photoemission studies of Yb 0.6 Ca 0.4 Al 2 and YbAl 2 alloys. Mixed valence behaviour was observed for Yb in both compounds with room temperature valence estimated at 2.28 ± 0.03 for Yb 0.6 Ca 0.4 Al 2 and 2.33 ± 0.03 for YbAl 2 . The lower intermediate valence for Yb in the pseudo-binary compound Yb 0.6 Ca 0.4 Al 2 is related to chemical pressure effects. Results at liquid nitrogen temperature indicate further reduction (about 10%) in the trivalent state contribution.

Optimization of Optical Properties of Polycarbonate Film with Thiol Gold-Nanoparticles

A new nanostructured composite film based on thiol gold nanoparticles dispersed in polycarbonate and prepared by evaporating a solution of 1-dodecanthiol gold nanoparticles and polycarbonate was developed for applications as optical lenses. Lenses with superior mechanical properties, coloring and UV ray absorption and with the same transparency as the matrix were obtained. The supporting highly transparent polycarbonate matrix and the chloroform solution of thiol gold nanoparticles, 3 nm mean size, was mixed according to a doping protocol employing different concentrations of thiol gold nanoparticles vs. polycarbonate. The presence of nanoparticles in the polymer films was confirmed by the spectrophotometric detection of the characteristic absorbance marker peak at 540–580 nm. The nanostructured films obtained show a better coverage in the UV-vis range (250–450 nm) even at very low doping ratios, of the order of 1:1,000. These results offer a very promising approach towards the development of efficient nanostructured materials for applications to optical lenses.

Evidence of strong correlations between anomalous lattice parameters and transport properties in Ce16Ru9

The new phase Ce16Ru9 (R3m, α  13.645 Aand c  22.742 A) was examined via the temperature dependences of the lattice parameters (10–300 K), magnetic susceptibility (1.5–300 K) and electrical resistivity (0.3–300 K). Different Ce valences (+4 and +3) for different crystallographic sites are proposed from magnetic data and are supported by previous structural results. No magnetic order is observed down to 0.3 K. Highly anisotropic stresses observed in the electrical resistivity temperature dependence are attributed to the anomalous thermal behaviour of the lattice parameter c.

Surface Morphology and Tooth Adhesion of a Novel Nanostructured Dental Restorative Composite

Recently, a novel dental restorative composite based on nanostructured micro-fillers of anodic porous alumina has been proposed. While its bulk properties are promising thanks to decreased aging and drug delivery capabilities, its surface properties are still unknown. Here we investigated the surface morphology and the adhesion to tooth dentin of this composite as prepared. For comparison, we used two commercial composites: Tetric EVO Flow (Ivoclar) and Enamel HRi Plus (Micerium). The surface morphology was characterized by atomic force microscopy and the adhesion strength by tensile tests. The experimental composite is rougher than the commercial composites, with root mean square roughness of ~549 nm against 170–511 nm, and presents an adhesion strength of ~15 MPa against 19–21 MPa. These results show at the same time some proximity to the commercial composites, but also the need for optimization of the experimental material formulation.

Curative therapies for hepatocellular carcinoma: an update and perspectives

ABSTRACT Curative treatments, including liver transplantation, surgical resection and percutaneous treatments, are the recommended therapies in BCLC-0 (Barcelona Clinic of Liver Cancer) or BCLC-A hepatocellular carcinoma (HCC). This review provides an overview of some issues of clinical importance concerning curative treatments in HCC.

Oriented thick films grown by cryoelectrophoretic deposition

High- thick films of (YBCO) were grown on Ag substrates by a cryoelectrophoretic technique, i.e. deposited by electrophoresis in a cryogenic environment. The orienting effect is provided by the application of an external magnetic field of small intensity (120 G). After sintering, these films exhibited a superconducting transition at 92 K in the electrical resistivity. Oriented films show significantly enhanced critical current densities. A detailed study of the structural and morphological properties of the film surfaces was undertaken using scanning electron microscopy, x-ray diffraction and scanning force microscopy (SFM). All microscopies revealed different types of film growth induced by the application of an external magnetic field during the cryogenic deposition showing an increasing degree of order with the field intensity (0 - 120 G). Observations of surface topography as studied by SFM are also discussed.

Crackling noise peaks as signature of avalanche correlation

Until now, all existing theories failed to explain peaks in the power noise spectra. Here we focus on the role of correlation among avalanches as the main source of the noise peaks observed. The present theory is based on first principles statistics of elementary events clustered in time-amplitude correlated avalanches. A noise spectral power master equation suitable to explain any peaked noise spectra is analytically achieved. Excellent agreement with our noise experiments in superconductors and with recent experiments in Escherichia coli, in single DNA molecule, and in single electron tunneling is reported.