Impact of the precursor chemistry and process conditions on the cell-to-cell variability in 1T-1R based HfO2 RRAM devices.

The Resistive RAM (RRAM) technology is currently in a level of maturity that calls for its integration into CMOS compatible memory arrays. This CMOS integration requires a perfect understanding of the cells performance and reliability in relation to the deposition processes used for their manufacturing. In this paper, the impact of the precursor chemistries and process conditions on the performance of HfO2 based memristive cells is studied. An extensive characterization of HfO2 based 1T1R cells, a comparison of the cell-to-cell variability, and reliability study is performed. The cells' behaviors during forming, set, and reset operations are monitored in order to relate their features to conductive filament properties and process-induced variability of the switching parameters. The modeling of the high resistance state (HRS) is performed by applying the Quantum-Point Contact model to assess the link between the deposition condition and the precursor chemistry with the resulting physical cells characteristics.

Uso de língua bovina na prática de técnicas de sutura / Suturing techiniques teaching method using bovine tongue

The authors present a method of teaching of suture techniques being used instrumental surgical and bovine tongue used in the evaluation of the graduation students' learning. The evaluation of the technique, used since January 2000, considering students' motivation, learning curve, practical applicability, quality of the biological material used and similarity to the human tegument. The acceptance for the students was very good and the bovine tongue was shown material of easy acquisition and extremely useful in the teaching of suture techniques. The presented method is simple, easily reproductible and interesting. The bovine tongue is similar to the skin and the subcutaneous tissue, providing more enlightening and stimulants practical lessons.

Tratamento cirúrgico de orelhas constrictas / Contricted ear surgical treatment

Introdução: As orelhas constrictas apresentam-se sob formas variadas, tendo em comum o comprometimento predominante do terço superior. As deformidades podem ser de resolução técnica simples ou até necessitarem de reconstruções complexas de todo o segmento, com enxertia de cartilagem costal. Método: No período de 2000 a 2004, foram operados oito pacientes, totalizando 10 orelhas constrictas, com apresentações diferentes, no Serviço de Cirurgia Plástica do Hospital Universitário da Universidade Federal do Rio de Janeiro. Os pacientes foram acompanhados por um período que variou de 1 ano a 3 anos e 6 meses. Este trabalho tem como objetivo descrever as técnicas cirúrgicas utilizadas, de acordo com a gravidade da deformidade anatômica. Resultados: Os casos foram analisados de forma retrospectiva, evidenciando-se boa evolução, sem intercorrências ou recidivas. Conclusão: Concluímos que o tratamento das orelhas constritas necessita de um arsenal de técnicas adaptáveis às suas múltiplas formas. Cirurgias mal-sucedidas podem dificultar reconstruções futuras.