2,255 research outputs found
Redescription and designation of a neotype for Ophiothrix angulata (Say, 1825) (Echinodermata: Ophiuroidea: Ophiotrichidae)
No full textSantana, Alisson, Manso, Cynthia L.C., Almeida, Ana C.S., Alves, Orane F.S. (2017): Redescription and designation of a neotype for Ophiothrix angulata (Say, 1825) (Echinodermata: Ophiuroidea: Ophiotrichidae). Zootaxa 4344 (2): 291-307, DOI: https://doi.org/10.11646/zootaxa.4344.2.
Nucleation And Growth Of Cdte1-xsx Nanocrystals Embedded In A Borosilicate Glass. Effects Of Sulfur Content And Two-step Thermal Annealing
No full textNucleation and growth of CdTe1-xSx nanocrystals embedded in a borosilicate glass matrix and submitted to isothermal annealing were studied by small-angle X-ray scattering (SAXS). Two different sulfur contents (x=0.3 and x=0.7) were investigated. The formation and growth of the nanocrystals was studied in situ, maintaining the samples at a constant temperature (560 °C) inside a high-temperature cell. The effect of a nucleation pretreatment at 460 °C on the characteristics of nanocrystal formation and growth was also studied. The experimental results demonstrate that, in composites with high sulfur content (x=0.7), nanocrystals grow during the isothermal annealing by coarsening of preformed small crystals. In glasses with low sulfur content (x=0.3), nanocrystals grow by progressive diffusion of Cd, Te and S atoms initially dispersed in the glass matrix. © 2001 Elsevier Science B.V. All rights reserved.293-2951517526Neto, J.A.M., Barbosa, L.C., Cesar, C.L., Alves, O.L., Galembeck, F., (1991) Appl. Phys. Lett., 59, p. 2715Craievich, A.F., Alves, O.L., Barbosa, L.C., (1993) J. Phys., 3, p. 373Craievich, A.F., Alves, O.L., Barbosa, L.C., (1995) Rev. Sci. Instrum., 66, p. 1338Bernardes, A., Tolentino, H., Rodrigues, A.R.D., Craievich, A.F., Torriani, I., (1992) Rev. Sci. Instrum., 63, p. 1065Kellermann, G., Vicentin, F., Tamura, E., Rocha, M., Tolentino, H., Barbosa, A., Craievich, A.F., Torriani, I., (1997) J. Appl. Cryst., 30, p. 880Potter B.G., Jr., Simmons, J.H., (1991) Phys. Rev. B, 43, p. 2234Glatter, O., Kratky, O., (1982) Small Angle X-ray Scattering, , Academic Press, LondonGuinier, A., Fournet, G., (1955) Small-angle Scattering of X-rays, , Wiley, New YorkSvergun, D.I., Semenyuk, A.V., Feigin, L.A., (1988) Acta Crystallogr. A, 44, p. 244Svergun, D.I., (1992) J. Appl. Cryst., 25, p. 495Christian, J.W., (1975) The Theory of Transformations in Metals and Alloys, , Pergamon, New YorkLifshitz, I.M., Slyozov, V.V., (1961) J. Phys. Chem. Solids, 19, p. 35Liu, Y., Reynoso, V.C.S., Royas, R.F.C., Brito Cruz, C.H., Cesar, C.L., Alves, O.L., (1996) J. Mater. Sci. Lett., 15, p. 98
Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species
No full textSantana, Alisson, Manso, Cynthia L.C., Almeida, Ana C.S., Alves, Orane F.S. (2020): Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species. Zootaxa 4808 (1): 51-78, DOI: 10.11646/zootaxa.4808.1.
Structural Geology of the Cariboo Gold Mining District, East-Central British Columbia:
No full textL.C. Struik.Memoir (Geological Survey of Canada) ; 421
Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species
No full textSantana, Alisson, Manso, Cynthia L.C., Almeida, Ana C.S., Alves, Orane F.S. (2020): Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species. Zootaxa 4808 (1): 51-78, DOI: https://doi.org/10.11646/zootaxa.4808.1.
Cdte Quantum Dots By Melt Heat Treatment In Borosilicate Glasses
No full textCdTe quantum dots in borosilicate glasses were produced and their growth kinetics, the effects of quantum confinement for electrons and phonons and the time resolved optical transmission were studied. Quantum dots in the range of 10 to 25 Å with a 5% size dispersion were grown. The growth kinetics were studied by small angle X-ray scattering using synchrotron light. A spherical k · p model for the electron confinement explains absorption data and selection rules, and a dielectric continuum model for the phonon confinement could explain the resonant longitudinal and surface optical phonons, as well as their overtone combinations. The time response of absorption was studied by a pump-probe measurement on the femtosecond time scale. For samples showing a large amount of surface traps the recovery time can be as fast as 300 fs, while for an almost surface trap free sample it remains on the 1-3 ps time scale. © 1997 Elsevier Science B.V.219205211Efros, A.L., Efros, A.L., (1982) Sov. Phys. Semicond., 16, p. 772Ekimov, A.I., Onushchenko, A.A., (1982) Sov. Phys. Semicond., 16, p. 775Warnock, J., Awschalom, D.D., (1985) Phys. Rev., B32, p. 5529Potter, B.G., Simmons, J.H., (1988) Phys. Rev., B37, p. 10838Borrelli, N.F., Hall, D.W., Holland, H.J., Smith, D.W., (1987) J. Appl. Phys., 61, p. 5399Banyai, L., Hu, Y.Z., Lindberg, M., Koch, S.W., (1988) Phys. Rev., B38, p. 8142Peyghambarian, N., Fluegel, B., Hulin, D., Migus, A., Joffre, M., Antonetti, A., Koch, S.W., Lindberg, M., (1989) IEEE J. Quant. Elect., 25, p. 2516Alivisatos, A.P., Colvin, V.L., Goldstein, A.N., Olshavsky, M.A., Shiang, J.J., (1990) Physical Phenomena in Granular Materials, p. 870. , ed. T.H. Geballe, G.C. Cody and P. Sheng Materials Research Society, Pittsburg, PARighini, G.C., (1996) Proc. SPIE, Optics for Science and New Technology, 2778Mackenzie, J.D., Ulrich, D.R., (1990) SPIE Proc. Sol-Gel Optics, 1328, p. 2Nasu, H., Tsunetomo, K., Tokumitsu, Y., Osaka, Y., (1989) Jap. J. Appl. Phys., 25, pp. L862Ekimov, A.I., Onushchenko, A.A., (1982) Sov. Phys. Semicond., 16, p. 775Neto, J.A.M., Barbosa, L.C., Alves, O.L., Garrido, F.M.S., (1991) Proc. 2nd Int. Ceram. Sci. Tech., Ceram. Trans., 20, p. 161Reynoso, V.C.S., De Paula, A.M., Cuevas, R.F., Medeiros Neto, J.A., Alves, O.L., Cesar, C.L., Barbosa, L.C., (1995) Electr. Lett., 31, p. 1013Tsunetomo, K., Ohtsuka, S., Koyama, T., Tanaka, S., Sasaki, F., Kobayashi, S., (1995) Nonlinear Opt., 13, p. 109Medeiros Neto, J.A., Barbosa, L.C., Cesar, C.L., Alves, O.L., Galembeck, F., (1991) Appl. Phys. Lett., 59, p. 2715Esch, V., Fluegel, B., Khitrova, G., Gibbs, H.M., Jiang, Xu., Kang, K., Koch, S.W., Peyghanbarian, N., (1990) Phys. Rev., B42, p. 7450Liu, Y., Reynoso, V.C.S., Barbosa, L.C., Brito Cruz, C.H., Cesar, C.L., Fragnito, H.L., Alves, O.L., (1996) J. Mater. Sci. Lett., 15, p. 142Craievich, A.F., Alves, O.L., Barbosa, L.C., (1993) J. Phys. (Paris) Colloq., C8, p. 373Craievich, A.F., Alves, O.L., Barbosa, L.C., (1995) Rev. Sci. Instrum., 66, p. 1338Reynoso, V.C.S., Liu, Y., Rojas, R.F.C., Aranha, N., Cesar, C.L., Barbosa, L.C., Alves, O.L., (1996) J. Mater. Sci. Lett., 15, p. 1037Liu, Y., Reynoso, V.C.S., Barbosa, L.C., Rojas, R.F.C., Fragnito, H.L., Cesar, C.L., Alves, O.L., (1995) J. Mater. Sci. Lett., 14, p. 635Liu, Y., Reynoso, V.C.S., Rojas, R.F.C., Brito Cruz, C.H., Cesar, C.L., Fragnito, H.L., Alves, O.L., Barbosa, L.C., (1996) J. Mater. Sci. Lett., 15, p. 892De Paula, A.M., Barbosa, L.C., Brito Cruz, C.H., Alves, O.L., Sajurjo, J.A., Cesar, C.L., (1996) Appl. Phys. Lett., 69, p. 357De Oliveira, C.R.M., De Paula, A.M., Plentz Filho, F.O., Medeiros Neto, J.A., Barbosa, L.C., Alves, O.L., Menezes, E.A., Cesar, C.L., (1995) Appl. Phys. Lett., 66, p. 439Fragnito, H.L., Rios, J.M.M., Duarte, A.S., Palange, E., Medeiros Neto, J.A., Cesar, C.L., Barbosa, L.C., Brito Cruz, C.H., (1993) J. Phys.: Condensed Mater., 5, pp. A179Paul, A., (1982) Chemistry of Glasses, p. 148. , Chapman and Hall, LondonDuffy, J.A., Ingram, M.D., (1976) J. Non-Cryst. Solids, 21, p. 373Yükselici, H., Persan, P.D., Hayes, T.M., (1995) Phys. Rev., B52, p. 11763Landau, L.D., Lifshitz, E.M., (1993) Physical Kinetics, p. 427. , Pergamon, OxfordTurnbull, D., (1956) Solid State Physics, p. 225. , ed. F. Seitz and D. Turnbull Academic Press, New YorkKoch, S.W., (1984) Lectures Notes in Physics, 207, p. 18. , Springer, BerlinChristian, J.W., (1981) The Theory of Transformations in Metals and Alloys, 2nd Ed., (PART I), p. 418. , Pergamon, OxfordBanyai, L., Koch, S.W., (1993) Semiconductor Quantum Dots, Series on Atomic, Molecular and Optical Physics, 2. , World Scientific, SingaporeLiu, L.C., Risbud, S.H., (1990) J. Appl. Phys., 68, p. 28Lifshitz, I.M., Slyozov, V.V., (1959) Sov. Phys. JETP, 35, p. 331Lifshitz, I.M., Slyozov, V.V., (1961) J. Phys. Chem. Solids, 19, p. 3
Structural Characterisation Of Cscl Incorporation In Ga2s3-la2s3 Glasses
No full textWe report X-ray absorption spectroscopy study of (80 - x)Ga2S3-20La2S3-xCsCl glasses, with x = 0-40. The addition of CsCl to Ga2S3-La2S3 glasses increases their thermal stability making them suitable a host-matrix for luminescent rare earth ions. The gallium-based network is composed of almost regular tetrahedra of sulfur atoms connected by corners. The average local lanthanum site is a distorted polyhedron of sulfur atoms at a distance of 2.96 ± 0.01 Å, with a coordination number close to 7. There is no alteration in the local environment of these elements in the doped glasses with respect to the undoped one detected in the X-ray absorption spectra. The chlorine and cesium sites, as observed in the X-ray absorption spectra, are similar to that in CsCl. These experimental observations are compatible with a model in which these elements are incorporated in network ionic vacancies in the form of CsCln units. © 2002 Elsevier Science B.V. All rights reserved.3041-3182187Hewak, D.W., Deol, R.S., Wang, J., Wylangowski, G., Medeiros Neto, J.A., Samson, B.N., Laming, R.I., Payne, D.N., (1993) Electron. Lett., 29, p. 237Wang, J., Hector, J.R., Brady, D., Hewak, D., Broslesby, B., Kluth, M., Moore, R., Payne, D.N., (1997) Appl. Phys. Lett., 71, p. 1753Medeiros Neto, J.A., Taylor, E., Samson, B., Wang, J., Hewak, D.W., Laming, R.I., Payne, D.N., Hanney, R., (1995) J. Non-Cryst. Solids, 184, p. 292Youden, K.E., Grevatt, T., Eason, R.W., Rutt, H.N., Deol, R.S., Wylangowsky, G., (1993) Appl. Phys. Lett., 63, p. 1601Hewak, D.W., More, R.C., Schweitzer, T., Wang, J., Samson, B., Broklesby, W.S., Payne, D.N., Trabox, E.J., (1996) Electron. Lett., 32, p. 384Hewak, D.W., Deol, R.S., Wang, J., Wylangowski, G., Medeiros Neto, J.A., Samson, B.N., Laming, R.I., Payne, D.N., (1993) Electron. Lett., 29, p. 237Wang, J., Hector, J.R., Brady, D., Hewak, D., Broslesby, B., Kluth, M., Moore, R., Payne, D.N., (1997) Appl. Phys. Lett., 71, p. 1753Smorlorz, S., Lui, X., Quian, L., Wise, F., Wang, J., Brady, D., Hewak, D., Payne, D.N., (1998) Electron. Lett., 34, p. 2268Marmolejo, E.M., Granado, E., Alves, O.L., Cesar, C.L., Barbosa, L.C., (1999) J. Non-Cryst. Solids, 247, p. 189Ramos, A.Y., Cardona, M.G., Tolentino, H.C.N., Alves, M.C.M., Watanabe, N., Alves, O.L., Barbosa, L.C., (2001) J. Mater. Res., 16, p. 1349Tolentino, H.C.N., Ramos, A.Y., Alves, M.C.M., Barrea, R., Tamura, E., Cezar, J.C., Watanabe, N., (2001) J. Synchrotron Rad., 8, p. 1040Eanes, E.D., Costa, J.L., MacKenzie, A., Warburton, W.K., (1980) Rev. Sci. Instrum., 51, p. 1579Budavari, S., (1996) The Merck Index, An Encyclopedia of Chemical, Drugs, and Biologicals, 12th Ed., , Merck Research laboratories Division of Merck & Co, Inc. Whitehouse Station, NJ, USARamos, A.Y., Tolentino, H., Alves, M.C.M., (2000) LNLS Technical Memorandum-MeT01/00, , www.lnls.brKrause, M.O., Oliver, J.H., (1979) J. Phys. Chem. Ref. Data, 8, p. 329Bianconi, A., Garcia, J., Benfatto, M., (1988) Topics in Current Chemistry, 145, p. 29. , Springer, BerlinSayers, D.E., Bunker, B.A., (1998) X-ray Absorption: Principles, applications, techniques of EXAFS, SEXAFS and XANES, p. 271. , D.C. Koningsberger, R. Prins (Eds.), Wiley-Interscience, New YorkRessler, T., (1997) J. Phys. (Paris) IV, 7 (C2), p. 269Rehr, J.J., Albers, R.C., (2000) Rev. Mod. Phys., 72, p. 621Benazeth, S., Tuilier, M.H., Loireau-Lozach, A.M., Dexpert, H., Lagarde, P., Flahaut, J., (1989) J. Non-Cryst. Solids, 110, p. 89Alves, M.C.M., Ramos, A.Y., Watanabe, N., (2001) J. Synchrotron Radiat., 8, p. 794(1964) Crystal Structures, 2nd Ed., 2. , Inorganic Compounds RXn, RnMX2, RnMX3, Wiley, New YorkBrown, G.E., Farges, F., Calas, G., (1995) Rev. Mineral., 32, p. 317Clare, A.G., (1994) Key Eng. Materials, 94-95, p. 8
Depolarization and decreased surface expression of K+ channels contribute to NSAID-inhibition of intestinal restitution
No full textNon-steroidal anti-inflammatory drugs (NSAIDs) contribute to gastrointestinal ulcer formation by inhibiting epithelial cell migration and mucosal restitution; however, the drug-affected signaling pathways are poorly defined. We investigated whether NSAID inhibition of intestinal epithelial migration is associated with depletion of intracellular polyamines, depolarization of membrane potential (Em) and altered surface expression of K+ channels. Epithelial cell migration in response to the wounding of confluent IEC-6 and IEC-Cdx2 monolayers was reduced by indomethacin (100μM), phenylbutazone (100μM) and NS-398 (100μM) but not by SC-560 (1μM). NSAID-inhibition of intestinal cell migration was not associated with depletion of intracellular polyamines. Treatment of IEC-6 and IEC-Cdx2 cells with indomethacin, phenylbutazone and NS-398 induced significant depolarization of Em, whereas treatment with SC-560 had no effect on Em. The Em of IEC-Cdx2 cells was: −38.5±1.8mV under control conditions; −35.9±1.6mV after treatment with SC-560; −18.8±1.2mV after treatment with indomethacin; and −23.7±1.4mV after treatment with NS-398. Whereas SC-560 had no significant effects on the total cellular expression of Kv1.4 channel protein, indomethacin and NS-398 decreased not only the total cellular expression of Kv1.4, but also the cell surface expression of both Kv1.4 and Kv1.6 channel subunits in IEC-Cdx2. Both Kv1.4 and Kv1.6 channel proteins were immunoprecipitated by Kv1.4 antibody from IEC-Cdx2 lysates, indicating that these subunits co-assemble to form heteromeric Kv channels. These results suggest that NSAID inhibition of epithelial cell migration is independent of polyamine-depletion, and is associated with depolarization of Em and decreased surface expression of heteromeric Kv1 channels.ID: S0006295207001931; M3: Article; Accession Number: S0006295207001931; Author: L.C. Freeman (b); Author: D.F. Narvaez (a); Author: A. McCoy (a); Author: F.B. von Stein (c); Author: S. Young (b); Author: K. Silver (a); Author: S. Ganta (b); Author: D. Koch (b); Author: R. Hunter (b); Author: R.F. Gilmour (c); Author: J.D. Lillich (a, ⁎); Affiliation: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, United States; Keyword: Non-steroidal anti-inflammatory drugs; Keyword: Intestinal epithelial cells; Keyword: Membrane potential; Keyword: Potassium channels; Number of Pages: 12; Language: English;Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=edselp&AN=S0006295207001931&site=eds-live&scope=sit
FIGURE 8. Ophiothrix spiniformis n in Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species
No full textFIGURE 8. Ophiothrix spiniformis n. sp.: A, Dorsal view of the disc; B, SEM of the disc spine; C, detail of radial shields covered by short spines; D, oral frame; E, dorsal arm plates; F, ventral arm plates; G, SEM image of dorsal arm plate; H, SEM image of ventral arm plate (ZUEC 02374, holotype, Paraná, Brazil). Scale bars: A, C–F = 1 mm; B = 500 μm; G–H = 100 μm.Published as part of Santana, Alisson, Manso, Cynthia L.C., Almeida, Ana C.S. & Alves, Orane F.S., 2020, Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species, pp. 51-78 in Zootaxa 4808 (1) on page 63, DOI: 10.11646/zootaxa.4808.1.3, http://zenodo.org/record/392790
FIGURE 6. Ophiothrix brasiliensis n in Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species
No full textFIGURE 6. Ophiothrix brasiliensis n. sp.: A, Dorsal view of the disc; B–D, SEM detail of spines on the disc; E, detail of radial shields coverage; F, oral frame; G, dorsal arm plates; H, ventral arm plates; I, SEM image of dorsal arm plate; J, SEM image of ventral arm plate (UFBA 01731, holotype, Bahia, Brazil). Scale bars: A, E–H = 1 mm; B–C = 50 μm; D = 20 μm; I–J = 100 μm.Published as part of Santana, Alisson, Manso, Cynthia L.C., Almeida, Ana C.S. & Alves, Orane F.S., 2020, Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species, pp. 51-78 in Zootaxa 4808 (1) on page 60, DOI: 10.11646/zootaxa.4808.1.3, http://zenodo.org/record/392790
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