Electrochemically prepared oxides for resistive switching memories.

Redox-based resistive switching memories (ReRAMs) are the strongest candidates for next generation nonvolatile memories. These devices are commonly composed of metal/solid electrolyte/metal junctions, where the solid electrolyte is usually an oxide layer. A key aspect in the ReRAMs development is the solid electrolyte engineering, since it is crucial to tailor the material properties for obtaining excellent switching properties (e.g. retention, endurance, etc.). Here we present an anodizing process as a non vacuum and low temperature electrochemical technique for growing oxides with tailored structural and electronic properties. The effect of the anodizing conditions on the solid state properties of the anodic oxides is studied in relation to the final ReRAM device performances demonstrating the great potentiality of this technique to produce high quality oxide thin films for resistive switching memories.

Photoelectrochemical evidence of nitrogen incorporation during anodizing sputtering--deposited Al-Ta alloys.

Anodic films were grown to 20 V on sputtering-deposited Al-Ta alloys in ammonium biborate and borate buffer solutions. According to glow discharge optical emission spectroscopy, anodizing in ammonium containing solution leads to the formation of N containing anodic layers. Impedance measurements did not evidence significant differences between the dielectric properties of the anodic films as a function of the anodizing electrolyte. Photoelectrochemical investigation allowed evidencing that N incorporation induces a red-shift in the light absorption threshold of the films due to the formation of allowed localized states inside their mobility gap. The estimated Fowler threshold for the internal photoemission processes of electrons resulted to be independent of the anodizing electrolyte confirming that N incorporation does not appreciably affect the density of states distribution close to the conduction band mobility edge. The transport of photogenerated carriers has been rationalized according to the Pai-Enck model of geminate recombination.

Comments on 'Formation and characterization of nanotubes of La(OH)3 obtained using porous alumina membranes'.

New experimental evidence concerning the formation of La(OH)3 nanowires on anodic alumina membranes by cathodic polarization in 0.05 M lanthanum nitrate solution is provided to further support the conclusions previously reached in our work (Bocchetta et al 2007 Electrochem. Commun. 9 683-8) and recently criticized by González-Rovira et al (Nanotechnology 2008 19 495305). Some unconvincing aspects of the paper of González-Rovira et al, according to which the same electrochemical process should lead to the formation of hydroxycarbonate nanotubes, are also discussed.

Gastric carcinoma with osteoclast-like giant cells. Report of four cases.

Four cases of gastric carcinoma are described that are associated with an osteoclast-like giant cell (OGC) stromal component. The patients were all middle-aged men (range 53-63 years). Microscopically, the tumors were characterized by a bland cytologic appearance, and an either solid or cribriform pattern. Osteoclast-like giant cells were found adjacent to, or intimately intermixed with, the neoplastic cells in the primary gastric masses and in the lymph nodal metastases and were often associated with lymphocytes, histiocytes, and desmoplastic stroma. By immunohistochemistry, mononuclear cells and OGCs showed diffuse positivity for alpha-1-antichymotrypsin, alpha-1-antitrypsin, and CD68. Neoplastic cells that were positive for keratin and CEA, also showed reactivity for vimentin and the latent membrane protein of Epstein-Barr virus in one case. At follow-up, three patients had died at 13, 15, and 24 months after diagnosis, and one is still alive, without evidence of disease, after 120 months. This report describes a novel variant of gastric carcinoma with distinctive and histologic features.

[A quantitative analysis of nucleolar organizer regions (NORs) in renal adenocarcinoma]. / Analisi quantitativa delle regioni organizzatrici del nucleolo (NORs) nell'adenocarcinoma renale.

A quantitative analysis of nucleolar organizer regions (NORs) in renal adenocarcinoma is proposed. The NORs have been evaluated on paraffin sections by a silver staining methods. A series of 19 renal adenocarcinoma is tested. A significant statistical difference (P less than 0.001) is found between normal and neoplastic tubules and between different stages of neoplasia. The authors suggest that this method if supported by authors date, may be a new prognostic index.

Trabecular carcinoid of the skin with cellular stroma.

A case of trabecular carcinoid of the skin of an 80-year-old man is described. This tumor's structure is totally different from that of trabecular carcinomas as described by Toker and Tang and Toker. It is formed by long, irregularly branching, serpiginous trabeculae, which are Grimelius positive and chromogranin immunoreactive. This appears to be the first case of trabecular carcinoid reported in the skin. An adnexal origin for this tumor is suggested.

Neuroendocrine (Merkel cell) tumor of the skin: fine-needle aspiration cytology, histology, electron microscopy and immunohistochemistry of 12 cases.

A series of 12 cases of neuroendocrine (Merkel cell) tumor of the skin, observed in the last 4 years, is reported. The mean age of the patients, 10 females and 2 males, was 62.4 years. The head, buttocks and extremities were the primary locations. The recurrence rate was 33.3% and 2 patients died of their disease. The histology is characterized by small round cells growing in solid sheets, nests or trabeculae. Ultrastructural study showed cytoplasmic membrane-bound granules of neurosecretory type and collections of perinuclear intermediate filaments as constant findings. The presence of cytoskeletal proteins was studied with monoclonal antibodies against cytokeratin and neurofilaments, as well as neuron-specific enolase reactivity, by the immunoperoxidase technique in 7 cases. Cytokeratin was demonstrated in 5 tumors and neurofilaments in 3, whereas the neuron-specific enolase was positive in all tested cases. In 4 patients a fine-needle aspiration biopsy of the primary, skin recurrences or lymph node metastasis was performed, showing the reliability of this technique in the diagnosis and staging of the disease.

The value of endometrial cytology by scraping in 1,798 cases: screening in asymptomatic women and diagnosis in symptomatic ones.

A study of 1,798 endometrial cytological samples, obtained with an "endocyte" (a disposable scraping device) and controlled in histology is presented. The method was tested for its usefulness in screening of precancerous lesions and preclinical cancer in 1,248 asymptomatic women and in the diagnosis of endometrial pathology in 550 symptomatic ones. The classification of hyperplasia into benign simplex and complex hyperplasia and atypical hyperplasia was followed; atypical hyperplasia, considered real intraepithelial neoplasia, was included in the positive cases. Histological verification was made chiefly on cell block in asymptomatic cytologically negative cases and either on curettage or hysterectomies in the others. The main endometrial cytological patterns are described. On the basis of findings, considering also endocyte's low cost, effectiveness, and ease of use, we think the method could be usefully employed in screening of endometrial cancer for an asymptomatic population. In symptomatic women, the use of histologic procedures is still preferable, and cytology cannot be considered a "first option" method.

Malignant lymphoma, Burkitt's type: histologic report of two cases in Italy.

Two cases of undifferentiated Burkitt's type malignant lymphoma with prevalent ovarian localization and observed in Italy are described histologically. Some brief considerations about the extra African diffusion of this lymphoma are pointed out.