Thermo-desorption measurements during N-doped Ge-rich Ge2Sb2Te5crystallization.

Ge-rich Ge2Sb2Te5(GGST) is considered as one of the best candidates for industrial phase change memory production. GGST memory cells are generally embedded with Si or Ti nitride layers to prevent oxidation, as it leads to an undesired decrease of the GGST crystallization temperature. Furthermore, GGST films are usually doped with elements such as N, C, O, or Bi, aiming to delay GGST crystallization during the fabrication process as well as during memory cell operation. In this work, ultrahigh vacuum thermal desorption spectroscopy (TDS) was performed during isochronal annealing of a N-doped GGST film covered by a 10 nm-thick TiNxlayer. Desorption is observed before GGST crystallization, but the comparison between TDS andin situx-ray diffraction measurements shows that the main desorption peak, observed between 653 K and 703 K, occurs after GGST full crystallization. The most prominent desorbing species are Ar, N2, H2, and H. These results show that the TiNxpolycrystalline layer cannot prevent N atoms from leaving the GGST layer during annealing, suggesting a progressive change of the N-doped GGST chemical composition during thermal annealing and crystallization.

Kinetic Monte Carlo simulations of Ge-Sb-Te thin film crystallization.

Simulation of atomic redistribution in Ge-Sb-Te (GST)-based memory cells during SET/RESET cycling is needed in order to understand GST memory cell failure and to design improved non-volatile memories. However, this type of atomic scale simulations is extremely challenging. In this work, we propose to use a simplified GST system in order to catch the basics of atomic redistribution in Ge-rich GST (GrGST) films using atomistic kinetic Monte Carlo simulations. Comparison between experiments and simulations shows good agreements regarding the influence of Ge excess on GrGST crystallization, as well as concerning the GST growth kinetic in GrGST films, suggesting the crystallized GST ternary compound to be off-stoichiometric. According to the simulation of atomic redistribution in GrGST films during SET/RESET cycling, the film microstructure stabilized during cycling is significantly dependent of the GST ternary phase stoichiometry. The use of amorphous layers exhibiting the GST ternary phase stoichiometry placed at the bottom or at the top of the GrGST layer is shown to be a way of controlling the microstructure evolution of the film during cycling. The significant evolution of the local composition in the amorphous solution during cycling suggests a non-negligible variation of the crystallization temperature with operation time.

Use of light reflection rheography for diagnosis of axillary or subclavian venous thrombosis.

Noninvasive diagnosis of axillary and subclavian venous thrombosis or documentation of the post-thrombotic syndrome using modalities currently in use is not definitive. Light reflection rheography, which is a reflection of venous pressure changes in the extremity as recorded from the subdermal capillary plexus, was used to correctly diagnose axillary or subclavian venous thrombosis in 11 patients. A positive study was confirmed by phlebography in each instance. There were no instances of false-positive results. The methodology is simple, involving testing of the venous outflow from the upper extremity in response to exercise, application of venous congesting pressure, and measurement of the rate of venous outflow when the congesting pressure is released. Normal respiratory variations of an open venous system are also assessed by this noninvasive modality. The tracing obtained is easy to interpret and provides objective evidence of proximal venous occlusion. The test is not operator-dependent and the instrumentation is relatively inexpensive. We believe that light reflection rheography may be an exciting development in the noninvasive diagnosis of axillary or subclavian venous compromise and merits further trials.

[Urography with non-ionic contrast media. Multicenter experience on the optimization of the technic]. / Urografia con mezzi di contrasto non ionici. Esperienza multicentrica sulla ottimizzazione della tecnica.

The authors report the results of a multicentric experience based on 1200 urograms performed with nonionic contrast medium. The global diagnostic reliability is evaluated, together with the specific reliability for kidneys, ureters, and bladder, according to the various pathologies. The eventual need of radiographs of completion is showed. In searching for an optimization of the technique for nonionic contrast medium, a panoramic radiograph performed 10' after the end of the injection is pointed out as the key-moment of the test, being extremely rich in information, so as to help defining the most appropriate technique to continue the examination. For its excellent tolerability and high reliability, the nonionic contrast medium is recommended also in routine IVP, not only in risk patients.

Cytogenetic studies in primary and metastatic neuroendocrine Merkel cell carcinoma.

Direct preparations of five primary and metastatic neuroendocrine Merkel cell carcinomas of the skin were analyzed using a G-banding technique. A recurrent structural abnormality was a rearranged chromosome #1 with involvement of p and q arms. In two cases this rearrangement appeared as a unique structural cytogenetic change. Evidence for clonal origin and karyotypic stability of this tumor was suggested by the occurrence of the same karyotypic changes in two metachronous metastases and in primary and metastatic tumor specimens of two different patients. The bands involved in rearrangements could be of significance in the molecular process of the neoplastic transformation of Merkel tumor because genes relevant to the differentiation of neural crest-derived tissue have been mapped in those regions.

Chromosomal abnormalities in a primary small cell lung cancer.

A cytogenetic analysis of a fresh primary tumor specimen of small cell lung cancer showed a del(3)(p14p23) in the majority of metaphases. Additional clonal changes were found in the karyotype. No abnormalities for Ha-ras, Ki-ras, N-ras, myb, or myc were detected by Southern blot analysis of the tumor DNA.

A cytogenetic, phenotypic, and molecular study of an immunoblastic lymphoma with a 14q + translocation.

An uncultured immunoblastic lymphoma, obtained from an untreated patient, was examined from a cytogenetic, immunophenotypic, and molecular viewpoint. The B-cell lineage, immunoglobulin light-chain type, and percentage of neoplastic cells were determined immunologically. Karyotyping showed the presence of a 14q + marker and suggested that the donor chromosome was chromosome 8. Southern-blot analysis of DNA from normal and lymphoma cells, using a molecular probes sequences related to the IGHJ and IGK immunoglobulin genes, confirmed the immunophenotype. A similar analysis, using probes homologous to IGHAC and MYC genes, showed that the t(8;14) detected by cytogenetic analysis resulted in a IGHAC-MYC rearrangement.

[Five-minute urogram: is it sufficient for a diagnosis?]. / L'urogramma a cinque minuti: è sufficiente per la diagnosi?

It has been demonstrated, studying in retrospect a great number of urographies, that the most reliable urogram is the 5 minute urogram (5-U) after the end of the infusion of ionic contrast medium. The authors therefore, in order to save costs and dose to the population, suggest to simplify the urographical routine examination executing only 5-U. This is suggested especially in urographical evaluation of urolithiasis, urinary tract infections, prostate pathology, pelvic masses, pathologies in which 5-U is highly reliable. Very important is the immediate evaluation of 5-U, that allows to complete the urographical examination when necessary.

[Home care for the hemophilic child: experience of 4 training courses for the parents]. / Trattamento domiciliare del bambino emofilico: esperienza di quattro corsi di addestramento per i genitori.

Much has already been written about training courses for home care of the hemophiliac held both in Italy and abroad. The advantages of home care are unquestionable. On one hand, the disorder becomes less hospital-dependent, and on the ofter, trough greater partecipation both the infusor and family become more responsible and competent on dealing with it. Hemophilia is a disease which puts the heaving burden on the pediatrics years. A specialized pediatric center is undoubtedly ideal for providing "global" assistance to the hemophilic child and his family so as to prevent any physical consequence of the disorder. There is a natural setting for training courses for home care for parents where they receive proper instruction with respect to problems that are often solely pediatric. The purpose of the course is not just to teach how to reconstitute and infuse freeze-dried concentrate, a practice which is, in itself, fairly easy, but also to give the parents through explanation, and a chance to meet with other parents to exchange ideas and experience.