Micro-structured Er 3+-tm 3+ Co-doped Tellurite Fiber For Broadband Optical Amplifier Around 1550nm

Micro-structured Er 3+-Tm 3+ co-doped tellurite fiber with three rings of holes was fabricated using a soft glass drawing tower by a stack-and-draw technique. Amplified spontaneous emission (ASE) around 1550nm band were observed when pumped with both, 980nm and 790nm, lasers.6314Russell, P., Photonic crystal fibers (2003) Science, 299, pp. 358-362Knight, J.C., Photonic crystal fibers (2003) Nature, 424, pp. 847-851Kumar, V.V.R.K., George, A.K., Reeves, W.H., Knight, J.C., Russell, P.St.J., Omenetto, F.G., Taylor, A.J., Extruded soft glass photonic crystal fiber for ultrabroad supercontinuum generation (2002) Opt. Exp, 10 (25), pp. 1520-1525Chillcce, E.F., Cordeiro, C.M.B., Barbosa, L.C., Cruz, C.H.B., Er 3+-Tm 3+ co-doped tellurite fibers for broadband optical fiber amplifier around 1550nm band (2006) Opt. Fiber Technol., 12, pp. 185-195Chillcce, E.F., Rodriguez, E., Neves, A.A.R., Moreira, W.C., Cesar, C.L., Barbosa, L.C., Cruz, C.H.B., Tellurite photonic crystal fiber by a stack-and-draw technique (2006) J. Non-cryst. Solids, , accepted to publicationWhite, T.P., McPhedran, R.C., De Sterke, C.M., Botten, L.C., Steel, M.J., Confinement losses in microstructured optical fibers (2001) Opt. Lett, 26 (21), pp. 1660-1663Barbosa, L.C., Cruz, C.H.B., Cesar, C.L., Cordeiro, C.M.B., Chillcce, E.F., Production process of tellurite glass tubes, capillaries and rods Brazilian pending Patent No 018050002734Chillcce, E.F., Cordeiro, C.M.B., Rodriguez, E., Cruz, C.H.B., Cesar, C.L., Barbosa, L.C., Tellurite photonic crystal fiber with Er 3+-Tm 3+ for broadband optical amplifier in 1550nm (2006) Proc. of SPIE, 6116, p. 61160

Pbte Quantum Dots In Tellurite Glass Microstructured Optical Fiber

PbTe doped tellurite glass photonic optical fiber for non linear application were developed using rod in tube method in a draw tower. We follow the growth kinetics of the quantum dots in the optical fiber by High Resolution Transmission Electron Microscopy giving some results related with the growth kinetic of the same in function of time so much for optical fiber as for the glass bulk. Absorption peak near 1500 nm as observed and it was attributed the optical resonance due PbTe quantum dots in the core fiber.6902Tsunetomo, K., (1995) Nonlinear Opt, 13, p. 109Borrelli, N.F., Smith, D.W., (1994) J. Non-Cryst. Soi, 180, p. 25Lipovskii, A., Kolobkova, E.A., Petrikov, V., Kang, I., Olkhovets, A., Krauus, T., Thomas, M., Kycia, S., (1997) Appl. Phys. Lett, 71, p. 3406Reynoso, V.C.S., de Paula, A.M., Cuevas, R.F., Medeiros Neto, J.A., Alves, O.L., Cesar, C.L., Barbosa, L.C., (1995) Elect. Lett, 31 (12), pp. 1013-1014Rodrigues, E., Jimenez, E., Jacob, G.J., Neves, A.A.A., Cesar, C.L., Barbosa, L.C., (2005) Phisica E, 26, pp. 321-325Jacob, G.J., Cesar, C.L., Barbosa, L.C., Tellurite Glass Doped with PbTe Quantum Dots (2002) Physics and Chemistry of Glass, 43 C, pp. 250-253Jacob, G.J., Rodriguez, E., Barbosa, L.C., Cesar, C.L., Tellurite Glass Optical fiber doped with PbTe Quantum DotsPhotonics West 2005, The International Society for Optical Engineering SPIEEnomoto, Y., Tokuyama, M., Kawasaki, K., (1986) Act. Metall, 34, p. 2139Marqusee, J.A., Ross, J., (1984) J. Chem. Phys, 80, p. 536Lifshitz, E.M., Slyozov, V.V., (1961) J. Phys. Chem. Sol, 19, p. 3

Multiclasificadores basados en aprendizaje automático como herramienta para la evaluación del perfil neurotóxico de líquidos iónicos

Los líquidos iónicos poseen un perfil fisicoquímico único, el cual los provee de un amplio rango de aplicaciones. Su variabilidad estructural casi ilimitada permite su diseño para tareas específicas. Sin embargo, su sustentabilidad, específicamente su seguridad desde el punto de vista toxicológico, ha sido frecuentemente cuestionada. Este último aspecto limita significativamente el cumplimiento de las regulaciones establecidas por la Unión Europea para el registro, evaluación, autorización y restricción de compuestosquímicos (REACH), así como su aplicación final. Debido a que la mayoría de los líquidos iónicos no han sido sintetizados, se hace evidente la importancia del desarrollo de herramientas quimioinformáticas que, de forma eficiente, permitan evaluar el potencial toxicológico de estos compuestos. En este sentido, el uso combinado de múltiples clasificadores ha demostrado superar las limitaciones de desempeño asociadas al uso de clasificadores individuales. En el presente trabajo fueron evaluadas varias estrategias alternativas de multiclasificadores basados en técnicas de aprendizaje automático supervisado, como herramientas para la evaluación del perfil neurotóxico de líquidos iónicos basado en la inhibición de la enzima acetilcolinesterasa, como indicador de neurotoxicidad. Se obtuvieron dos multiclasificadores con una alta capacidad predictiva sobre un conjunto de validación externa (no utilizado en el proceso de aprendizaje de los modelos). De acuerdo a los resultados obtenidos el 96% de un conjunto de nuevos líquidos iónicos podrá ser correctamente clasificado con la utilizaciónde estos multiclasificadores, los cuales constituyen herramientas de toma de decisión útiles en el campo del diseño y desarrollo de nuevos líquidos iónicos sustentables

Two-photon Absorption In Direct Bandgap Semiconductors Quantum Dots

We present degenerate and nondegenerate two-photon absorption spectra in a series of CdSe and CdTe quantum dots. The measurements show that the two-photon absorption (2PA) spectrum is strongly dependent on the quantum dot size and that the 2PA coefficient decreases as the quantum dot size decreases, and it is larger for the frequency nondegenerate process. Previously we had shown a theoretical analysis of these results based on a simple model using the effective mass approximation. Although this model works well for larger quantum dots, it fails for the smaller ones. Here we use the more realistic k→ p→ model for the band structure and consider the hole band mixing in quantum dots to describe our data. This theory better describes the spectral structures for smaller quantum dots and also predicts the decrease of the 2PA coefficient with the decrease of quantum dot size. This is due to the reduction of the number of possible transitions and the blue shift of the optical bandgap from quantum confinement. This theory predicts the reduction of the 2PA coefficient with size, although our experimental results show an even stronger reduction.6327Larson, D.R., Zipfel, W.R., Willians, R.M., Clark, S.W., Bruchez, M.P., Wise, F.W., Webb, W.W., (2003) Science, 300, pp. 1434-1436Sargent, E.H., (2005) Adv. Matt., 17, pp. 515-522Padilha, L.A., Neves, A.A.R., Rodriguez, E., Cesar, C.L., Barobosa, L.C., Cruz, C.H.B., (2005) Appl. Phys. Lett., 86, pp. 1611111-1611113Uskov, A.V., O'Reilly, E.P., Manning, R.J., Webb, R.P., Cotter, D., Laemmlin, M., Ledentsov, N.N., Bimberg, D., (2004) IEEE Phot. Tech. Lett, 16, pp. 1265-1267Cerletti, V., Coish, W.A., Gywat, O., Loss, D., (2005) Nanotech., 16, pp. R27-R49Sercel, P.C., Vahala, K.J., (1990) Phys. Rev. B, 42, pp. 3690-3710Cotter, D., Burt, M.G., Manning, R.J., (1992) Phys. Rev. Lett., 68, pp. 1200-1203Seo, J.T., Yang, Q., Creekmore, S., Temple, D., Qu, L., Yu, W., Wang, A., Kim, J.H., (2003) Phys. E, 17, pp. 101-103Banfi, G.P., Degiorgio, V., Ricard, D., (1998) Adv. Phys., 47, pp. 447-510Padilha, L.A., Fu, J., Hagan, D.J., Van Stryland, E.W., Cesar, C.L., Barbosa, L.C., Cruz, C.H.B., (2005) Opt. Exp., 13, pp. 6460-6467Padilha, L.A., Fu, J., Hagan, D.J., Van Stryland, E.W., Cesar, C.L., Barbosa, L.C., Cruz, C.H.B., (2005) Proc. SPIE, 5931, pp. 226-235Fedorov, A.V., Baranv, A.V., Inoue, K., (1996) Phys. Rev. B, 54, pp. 8627-8632Sheik-Bahae, M., Said, A.A., Wei, T.H., Hagan, D.J., Van Stryland, E.W., (1990) IEEE J. of Quantum Electron., 26, pp. 760-769Negres, R.A., Hales, J.M., Kobyakov, A., Hagan, D.J., Van Stryland, E.W., (2002) IEEE J. Quantum Electron., 38, pp. 1205-1216Hales, J.M., Hagan, D.J., Van Stryland, E.W., Schafer, K.J., Morales, A.R., Belfield, K.D., Pacher, P., Bredas, J.L., (2004) J. Chem. Phys., 121, pp. 3152-3160Barbosa, L.C., Reynoso, V.C.S., De Paula, A.M., De Oliveira, C.R.M., Alves, O.L., Craievich, A.F., Marotti, R.E., Cesar, C.L., (1997) J. Non-cryst. Solids, 219, pp. 205-211Yu, W.W., Qu, L.H., Guo, W.Z., Peng, X.G., (2003) Chem. Mater., 15, p. 2854Bunge, S.D., Krueger, K.M., Boyle, T.J., Rodriguez, M.A., Headley, T.J., Colvin, V.L., (2003) J. Mater. Chem., 13, p. 1705Qu, L.H., Peng, X.G., (2002) J. Am. Chem. Soc., 124, p. 2049L.A. Padilha, J. Fu, D.J. Hagan, E.W. Van Stryland, C.L. Cesar, L.C. Barbosa, C.H.B. Cruz, D. Buso, and A. Martucci, to be published (2006)Kane, E.O., Semiconductors & Semimetals, 1. , Cap. 3Ekimov, A.I., Hache, F., Schanne-Klein, M.C., Richard, D., Flytzanis, C., Kudryavtsev, I.A., Yazeva, T.V., Efros, Al.L., (1993) J. Opt. Soc. Am. B, 10, pp. 100-10

Tellurite Photonic Crystal Fiber With Er3+-tm3+ For Broadband Optical Amplifier In 1550nm

Er3+-Tm3+ co-doped tellurite photonic crystal fiber was fabricated via a stack-and-draw procedure and without using extrusion in any stage. The final fiber presents a 187 nm bandwidth of amplified spontaneous emission (ASE) intensity around 1550nm when pumped with 790nm. In this manuscript a soft-glass tube fabrication technique, using the centrifugation method, is also shown.6116Knight, J.C., Birks, T.A., Russel, P.St.J., Atkin, D.M., All-silica single-mode optical fiber with photonic crystal cladding (1996) Opt. Lett, 21, pp. 1547-1549Jeong, H., Oh, K., Han, S.R., Morse, T.F., Characterization of broadband amplified spontaneous emission from an Er3+-Tm3+ -codoped silica fiber (2003) Opt. Lett, 367, pp. 507-511Chillcce, E.F., Rodriguez, E., Neves, A.A.R., Moreira, W.C., César, C.L., Barbosa, L.C., Er3+-Tm3+ co-doped tellurite fibers for broadband optical fiber amplifier around 1550 nm band (2005) Opt. Fiber Technol., , article in pressRussell, P., Photonic crystal fibers (2003) Science, 299, pp. 358-362Knight, J.C., Photonic crystal fibers (2003) Nature, 424, pp. 847-851Kumar, V.V.R.K., George, A.K., Knight, J.C., Russell, P.St.J., Tellurite photonic crystal fiber (2003) Opt. Exp, 20, pp. 2641-2645Kumar, V.V.R.K., George, A.K., Reeves, W.H., Knight, J.C., Russell, P.St.J., Omenetto, F.G., Taylor, A.J., Extruded soft glass photonic crystal fiber for ultrabroad supercontinuum generation (2002) Opt. Exp, 10 (25), pp. 1520-1525Kiang, K.M., Frampton, K., Monro, T.M., Moore, R., Tucknott, J., Hewak, D.W., Richardson, D.J., Rutt, H.N., Extruded singlemode non-silica glass holey optical fiber (2002) Electron. Lett, 38 (12), pp. 546-54

SEOM clinical guidelines for the treatment of head and neck cancer (2017)

Head and neck cancer (HNC) is defined as malignant tumours located in the upper aerodigestive tract and represents 5% of oncologic cases in adults in Spain. More than 90% of these tumours have squamous histology. In an effort to incorporate evidence obtained since 2013 publication, Spanish Society of Medical Oncology (SEOM) presents an update of HNC diagnosis and treatment guideline. The eighth edition of TNM classification, published in January 2017, introduces important changes for p16-positive oropharyngeal tumours, for lip and oral cavity cancer and for N3 category. In addition, there are new data about induction chemotherapy and the role of immunotherapy in HNC

Discrete molecular dynamics simulations of peptide aggregation

We study the aggregation of peptides using the discrete molecular dynamics simulations. At temperatures above the alpha-helix melting temperature of a single peptide, the model peptides aggregate into a multi-layer parallel beta-sheet structure. This structure has an inter-strand distance of 0.48 nm and an inter-sheet distance of 1.0 nm, which agree with experimental observations. In this model, the hydrogen bond interactions give rise to the inter-strand spacing in beta-sheets, while the Go interactions among side chains make beta-strands parallel to each other and allow beta-sheets to pack into layers. The aggregates also contain free edges which may allow for further aggregation of model peptides to form elongated fibrils.Comment: 15 pages, 8 figure

Uso da adubação orgânica e cobertura morta na cultura da calêndula (Calendula officinalis L.).

A calêndula representa fonte alternativa econômica principalmente para a agricultura familiar. O objetivo do presente trabalho foi avaliar os efeitos da adubação orgânica e do uso da cobertura morta sobre a produção de biomassa e teor de flavonóides totais em plantas de calêndula. O experimento foi realizado no Campus de Montes Claros da Universidade Federal de Minas Gerais, utilizando-se o delineamento em blocos casualizados em esquema fatorial 2x2x4 com quatro repetições: duas épocas de colheita, presença ou ausência de cobertura morta e quatro doses de composto orgânico (0, 30, 60 e 90 t ha-1). As maiores produções de biomassa e flavonóides totais foram verificadas com o aumento das doses de composto orgânico. Para os flavonóides totais o maior teor foi obtido na segunda colheita na presença de cobertura morta

Microscopic mechanisms of spin-dependent electric polarization in 3d oxides

We present a short critical overview of different microscopic models for nonrelativistic and relativistic magnetoelectric coupling including the so-called "spin current scenario", ab-initio calculations, and several recent microscopic approaches to a spin-dependent electric polarization in 3d oxides.Comment: 8 pages, 3 figure

Development Of Soft-glasses Photonic Crystal Fiber Made By Stacking-and-draw Technique

We have been able to produce soft glass conventional core-clad and micro-structured fibers using rod-and-tube and stack-and-draw method respectively. The stack-and-draw technique shows several difficulties when used with soft glasses, that we managed to avoid using two different lead and alkaline glasses. Non commercial glasses and fibers were thermo-mechanically and optically characterized.6469White, T.P., McPhedran, R.C., de Sterke, C.M., Botten, L.C., Steel, M.J., Confinement losses in micro structure optical fibers (2001) Opt. Lett, 26 (21), p. 1660Russell, P., Photonic crystal fibers (2003) Science, 299, pp. 358-362Knight, J.C., Photonic crystal fibers (2003) Nature, 424, pp. 847-851Chillcce, E.F., Cordeiro, C.M., Rodriguez, E., Brito Cruz, C.H., Cesar, C.L., Barbosa, L.C., Tellurite photonic crystal with Er 3+-Tm3+ for broadband optical amplifier in 1550nm (2006) Proc. of SPIE, 6116, p. 611604A. Hruby, Czech J. Phys. B, Evaluation of glass-forming tendency by means of DTA 1972, 22, 118