Evidence for Germanene growth on epitaxial hexagonal (h)-AlN on Ag(1 1 1).

In this work, a structural analysis of Ge layers deposited by molecular beam epitaxy (MBE) on Ag(1 1 1) surfaces with and without an AlN buffer layer have been investigated by x-ray Absorption Spectroscopy (XAS) at the Ge-K edge. For the Ge layers deposited on h-AlN buffer layer on Ag(1 1 1) an interatomic Ge-Ge distance [Formula: see text] Å is found, typical of 2-Dimensional Ge layers and in agreement with the theoretical predictions for free standing low-buckled Germanene presented in literature. First principles calculations, performed in the density functional theory (DFT) framework, supported the experimental RHEED and XAS findings, providing evidence for the epitaxial 2-D Ge layer formation on h-AlN/Ag(1 1 1) template.

Combinatorial plasma polymerization approach to produce thin films for testing cell proliferation.

Plasma enhanced physical vapor depositions are extensively used to fabricate substrates for cell culture applications. One peculiarity of the plasma processes is the possibility to deposit thin films with reproducible chemical and physical properties. In the present work, a combinatorial plasma polymerization process was used to deposit thin carbon based films to promote cell adhesion, in the interest of testing cell proliferation as a function of the substrate chemical properties. Peculiarity of the combinatorial approach is the possibility to produce in just one deposition experiment, a set of surfaces of varying chemical moieties by changing the precursor composition. A full characterization of the chemical, physical and thermodynamic properties was performed for each set of the synthesized surfaces. X-ray photoelectron spectroscopy was used to measure the concentration of carboxyl, hydroxyl and amine functional groups on the substrate surfaces. A perfect linear trend between polar groups' density and precursors' concentration was found. Further analyses reveled that also contact angles and the correspondent surface energies of all deposited thin films are linearly dependent on the precursor concentration. To test the influence of the surface composition on the cell adhesion and proliferation, two cancer cell lines were utilized. The cell viability was assessed after 24 h and 48 h of cell culture. Experiments show that we are able to control the cell adhesion and proliferation by properly changing the thin film deposition conditions i.e. the concentration and the kind of chemical moiety on the substrate surface. The results also highlight that physical and chemical factors of biomaterial surface, including surface hydrophobicity and free energy, chemical composition, and topography, can altered cell attachment.

Sustained in vitro release and cell uptake of doxorubicin adsorbed onto gold nanoparticles and covered by a polyelectrolyte complex layer.

Gold nanoparticles functionalized with doxorubicin and stabilized with multilayers of degradable polyelectrolyte were allowed to age in aqueous medium in vitro in order to show the possibility of drug release in cellular environment. The chemico-physical characteristics of the nanoparticles are reported. The observed release of doxorubicin (DOX) was pH-dependent, and it increased in acidic environment. Cell uptake of nanoparticles and drug release were monitored by laser scanning confocal microscopy. Data showed that drug-bearing nanoparticles delivered DOX into the nuclei of A549 cells, leading to pronounced cytotoxic effects to this lung tumor cells. Our results suggest that gold nanoparticles conjugated with doxorubicin could be used as a pH-triggered drug releasing carrier for tumor drug delivery.

[Current clinical use of radioisotopes in the study of platelet kinetics]. / Attualità sull'utilizzazione clinica delle indagini radioisotopiche nello studio della cinetica piastrinica.

Radioisotopic study of platelet kinetics can provide a preliminary orientation in the diagnosis of thrombocytopenia. A study of the platelet kinetics in thrombocytopenic and normal subjects using the Cr51 isologous platelet labelling technique and subsequent in vivo injection of the labelled platelets was conducted. The results obtained confirm the reliability and usefulness of the technique. The identification of the limitations involved and the recognition of their significance in processing data allows the hematologist and the general practitioner to allow the right amount of room for the study of platelet kinetics in the diagnosis of thrombocytopenia.

[Homogeneous dose distribution in the moving-strip technic]. / Omogeneizzazione della dose nella tecnica di moving-strip.

The moving-strip technique employing a 60Co beam, is used in radiotherapy for whole abdominal irradiation in ovarian tumours and lymphomas. With this technique the spread of received dose from single strip, around an average value, is very high. Our paper suggest a computerized method for a more homogeneous dose distribution in central strips and a lower dose in out-side tissues.