Molecular Dynamics Calculations of Grain Boundary Mobility in CdTe.

Molecular dynamics (MD) simulations have been applied to study mobilities of Σ3, Σ7 and Σ11 grain boundaries in CdTe. First, an existing MD approach to drive the motion of grain boundaries in face-centered-cubic and body-centered-cubic crystals was generalized for arbitrary crystals. MD simulations were next performed to calculate grain boundary velocities in CdTe crystals at different temperatures, driving forces, and grain boundary terminations. Here a grain boundary is said to be Te-terminated if its migration encounters sequentially C d · T e - C d · T e … planes, where "·" and "-" represent short and long spacing respectively. Likewise, a grain boundary is said to be Cd-terminated if its migration encounters sequentially T e · C d - T e · C d … planes. Grain boundary mobility laws, suitable for engineering time and length scales, were then obtained by fitting the MD results to Arrhenius equation. These studies indicated that the Σ3 grain boundary has significantly lower mobility than the Σ7 and Σ11 grain boundaries. The Σ7 Te-terminated grain boundary has lower mobility than the Σ7 Cd-terminated grain boundary, and that the Σ11 Cd-terminated grain boundary has lower mobility than the Σ11 Te-terminated grain boundary.

The use of trypan blue dye for strabismus reoperations, surgery complications, and especially for the identification and recovery of a "slipped" or "lost" extraocular muscle.

PURPOSE: To evaluate trypan blue dye in strabismus surgery for tissue identification, to find the lowest optimal concentration, and to describe histological findings. in tissue so stained. METHODS: Trypan Blue dye 0.1% was serially diluted and tested by tissue staining at progressively different concentrations. Fifteen patients were studied using the dye. RESULTS: Trypan Blue 0.1 percent was the optimal concentration. Muscle, tendon and fibrotic tissues were easily identified and distinguished with the dye at this concentration. Such tissue identification was most useful and enhanced the performance of strabismus surgical operations, and especially in identifying and retrieving slipped or temporarily lost extraocular muscles.Also a thin basement-like membrane surrounding the superior oblique muscle tendons was disclosed with PAS stain, suggesting the presence of glycosaminoglycans. CONCLUSIONS: Trypan Blue 0.1percent contrasts the different tissues, dying the muscle sheath, tendons and fibrotic tissues, but not staining the sclera and muscle fibers per se.

Risk indicators for periodontal diseases in Guatemalan adolescents / Indicadores de risco para as doenças periodontais em adolescentes guatemaltecos

Uma amostra selecionada ao acaso de 62 adolescentes na faixa etária de 11 a 15 anos, de 17 localidades diferentes na Guatelama, compôs o grupo a ser estudado. Profundidade de bolsa, índice de placa, e sangramento à sondagem foram computados de 6 sítios periodontais escolhidos ao acaso de cada participante (total de 372 sítios). Amostras de placa subgengival foram obtidas destes mesmos sítios. Em cada par de sítios, testes microbiológicos distintos foram processados, à saber: sítios 1 e 2 - teste BANA para T. denticola, P. gingivalis, e B forsythus, e anticorpos policlonais para A. actinomycetemcomitans; sítios 3 e 4 - detecção de fungos no agar SAB; sítios 5 e 6 - detecção de Entamoeba gingivalis pela técnica de Heidenhain. Um total de 66 por cento dos participantes evidenciaram ao menos um sítio com sangramento à sondagem, 42 por cento exibiram no minímo um sítio com profundidade de bolsa > 3mm, e 79 por cento exibiram alto índice de placa. O percentual correspondente de sítios foi 30 por cento, 12 por cento e 41 por cento. Nos sítios 1 e 2 (N = 124), 77 por cento e 47 por cento dos participantes testaram positivo para o teste BANA e para A. actinomycetemcomitans, respectivamente, totalizando 59 por cento e 31 por cento dos sítios. Nos sítios 3 e 4 (N = 124), fungos foram detectados em 43 por cento dos participantes e 39 por cento dos sítios. Nos sítios 5 e 6 (N = 124) E. giginvalis foi detectada em 21 por cento dos participantes e 11 por cento dos sítios. O risco para inflamação gengival severa e/ou profundidade de bolsa aumentada estava 1,5 e 5,2 vezes aumentado o resultado positivo para o teste de BANA ou para A. actinomycetemcomitans foi detectado num determinado sítio. Nenhuma associação foi verificada para fungos e para E.gingivalis