Dexamethasone intravitreal implant in previously treated patients with diabetic macular edema : Subgroup analysis of the MEAD study

Background: Dexamethasone intravitreal implant 0.7 mg (DEX 0.7) was approved for treatment of diabetic macular edema (DME) after demonstration of its efficacy and safety in the MEAD registration trials. We performed subgroup analysis of MEAD study results to evaluate the efficacy and safety of DEX 0.7 treatment in patients with previously treated DME. Methods: Three-year, randomized, sham-controlled phase 3 study in patients with DME, best-corrected visual acuity (BCVA) of 34.68 Early Treatment Diabetic Retinopathy Study letters (20/200.20/50 Snellen equivalent), and central retinal thickness (CRT) 65300 \u3bcm measured by time-domain optical coherence tomography. Patients were randomized to 1 of 2 doses of DEX (0.7 mg or 0.35 mg), or to sham procedure, with retreatment no more than every 6 months. The primary endpoint was 6515-letter gain in BCVA at study end. Average change in BCVA and CRT from baseline during the study (area-under-the-curve approach) and adverse events were also evaluated. The present subgroup analysis evaluated outcomes in patients randomized to DEX 0.7 (marketed dose) or sham based on prior treatment for DME at study entry. Results: Baseline characteristics of previously treated DEX 0.7 (n = 247) and sham (n=261) patients were similar. In the previously treated subgroup, mean number of treatments over 3 years was 4.1 for DEX 0.7 and 3.2 for sham, 21.5 % of DEX 0.7 patients versus 11.1 % of sham had 6515-letter BCVA gain from baseline at study end (P = 0.002), mean average BCVA change from baseline was +3.2 letters with DEX 0.7 versus +1.5 letters with sham (P = 0.024), and mean average CRT change from baseline was -126.1 \u3bcm with DEX 0.7 versus -39.0 \u3bcm with sham(P < 0.001). Cataract-related adverse events were reported in 70.3 % of baseline phakic patients in the previously treated DEX 0.7 subgroup; vision gains were restored following cataract surgery. Conclusions: DEX 0.7 significantly improved visual and anatomic outcomes in patients with DME previously treated with laser, intravitreal anti-vascular endothelial growth factor, intravitreal triamcinolone acetonide, or a combination of these therapies. The safety profile of DEX 0.7 in previously treated patients was similar to its safety profile in the total study population

Spectroscopic and laser properties of Er3+ doped fluoro-phosphate glasses as promising candidates for broadband optical fiber lasers and amplifiers

Sem informaçãoDifferent fluoro-phosphate glasses doped with 0.5 mol% Er3+ doped are prepared by melt quenching method. Both structural and spectroscopic properties have been characterized in order to evaluate their potential as both laser source and amplifier materials. Optical absorption measurements are carried out and analyzed through Judd-Ofelt and Mc-Cumber theories where spectroscopic parameters such as intensity parameters Omega(i) (lambda = 2,4,6), transition probabilities, radiative lifetimes, stimulated absorption cross-sections and emission cross-sections at 1.5 mu m have been evaluated for Er3+ doped different fluorophosphate glasses. The various luminescence and gain properties are explained from photoluminescence studies. The decay curve analysis have been done for obtaining the decay time constants of Er3+ excited level I-4(13/2) in all the fluoro-phosphate glasses. The obtained results of each glass matrix are compared with the equivalent parameters for several other host glasses. These fluoro-phosphate glasses are found to be suitable candidates for laser and amplifier applications. (C) 2015 Elsevier Ltd. All rights reserved.Different fluoro-phosphate glasses doped with 0.5 mol% Er3+ doped are prepared by melt quenching method. Both structural and spectroscopic properties have been characterized in order to evaluate their potential as both laser source and amplifier materials. Optical absorption measurements are carried out and analyzed through Judd-Ofelt and Mc-Cumber theories where spectroscopic parameters such as intensity parameters Omega(i) (lambda = 2,4,6), transition probabilities, radiative lifetimes, stimulated absorption cross-sections and emission cross-sections at 1.5 mu m have been evaluated for Er3+ doped different fluorophosphate glasses. The various luminescence and gain properties are explained from photoluminescence studies. The decay curve analysis have been done for obtaining the decay time constants of Er3+ excited level I-4(13/2) in all the fluoro-phosphate glasses. The obtained results of each glass matrix are compared with the equivalent parameters for several other host glasses. These fluoro-phosphate glasses are found to be suitable candidates for laser and amplifier applications.70935944Sem informaçãoSem informaçãoSem informaçãoOne of the authors S. Babu would like to thank University Grants Commission (UGC), New Delhi for the sanction of SRF under Research Fellowship in Sciences for Meritorious Students (RFSMS) scheme

Spectroscopic properties of Ho3+, Tm3+ and Ho3+/Tm3+ doped tellurite glasses for fiber laser applications

Several papers were reported on spectroscopic properties of rare earth doped different host glasses. A complete knowledge of fluorescence properties of rare earth ions in laser materials is necessary to achieve efficient, compact and cheap sources of laser radiation for NIR and mid-IR region. Tellurite glasses are potentially useful for generation of NIR and mid-IR laser radiation due to its special features such as lowest phonon energy (750 cm-1) among oxide glasses, reasonably wide transmission region (0.35 - 5μm), good glass stability, good rare earth ion solubility, high linear and non-linear refractive index. In the present work, authors prepared Ho3+ and Tm3+ singly doped and Ho3+/Tm3+ co-doped tellurite glasses using conventional melt-quenching method. Spectroscopic measurements and analysis of energy transfer process in Ho3+, Tm 3+ and Ho3+ /Tm3+ co-doped glasses pumped with 785nm and 451 nm excitation wavelengths have been performed. There are some spectroscopic properties which are important in understanding and modeling of rare earth doped laser materials. Using Judd-Ofelt theory, radiative transition rates (Arad), radiative lifetimes (τR) and branching ratios (β) were estimated for certain excited states of Ho3+ and Tm3+ doped tellurite glasses. The emission cross-sections and gain coefficients have been determined from the absorption spectra of Ho3+ and Tm3+ ions in tellurite glasses. The energy transfer process such as ion cross-relaxation, Tm3+-Ho3+ energy transfer and energy transfer upconversion were studied and identified to specific candidate for laser operation8961FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2009/54066-7Fiber Lasers XI: Technology, Systems, and Applications2014-02-03San Francisco, CA; United State

Study of multicomponent fluoro-phosphate based glasses: Ho3+ as a luminescence center

Sem informaçãoThe multicomponent 49.5P(2)O(5)-10AlF(3)-10BaF(2)-10SrF(2)-10PbO-10M (M=Li2O, Na2O, K2O, ZnO and Bi2O3) glasses doped with 0.5 mol% holmium were prepared by melt quenching technique. Their thermal behavior was examined from differential scanning calorimetry (DSC). It is found that bismuth fluorophosphate glass matrix has good thermal stability. Their structures were characterized by the X-ray diffraction with SEM analysis, fourier transform infrared (FTIR), Raman spectroscopy and magic angle spinning (MAS) nuclear magnetic resonance (NMR) techniques. It was found that the phosphate network of these glasses was composed mainly of Q(2) and Q(3) phosphate tetrahedral units. The Judd-Ofelt parameters (J-O) (Omega(2), Omega(4) and Omega(6)) were evaluated from the intensities of the energy levels through optical absorption spectra. The most intense transitions are observed in the visible region of the spectrum. It is observed that the transition I-5(8) -> (5)G(6) is the hypersensitive transition for Ho3+ ion. With these J-O parameters, various radiative properties like the probabilities of radiative transitions, radiative lifetimes and branching ratios have been calculated for different fluoro-phosphate glasses. The luminescence kinetics from excited holmium levels have been studied upon selective excitation through photoluminescence measurements. Holmium produces two visible laser emissions i.e. one is green (F-5(4)(S-5(2)) -> I-5(8)) and another one is red (F-5(5) -> I-5(8)). The lifetimes of these levels have been experimentally determined through decay profile studies. The above results suggest that the prepared bismuth fluorophosphate glass system could be a suitable candidate for using it as a green laser source (F-5(4)(S-5(2)) -> I-5(8)) in the visible region of the spectrum. (C) 2015 Elsevier B.V. All rights reserved.The multicomponent 49.5P(2)O(5)-10AlF(3)-10BaF(2)-10SrF(2)-10PbO-10M (M=Li2O, Na2O, K2O, ZnO and Bi2O3) glasses doped with 0.5 mol% holmium were prepared by melt quenching technique. Their thermal behavior was examined from differential scanning calorimetry (DSC). It is found that bismuth fluorophosphate glass matrix has good thermal stability. Their structures were characterized by the X-ray diffraction with SEM analysis, fourier transform infrared (FTIR), Raman spectroscopy and magic angle spinning (MAS) nuclear magnetic resonance (NMR) techniques. It was found that the phosphate network of these glasses was composed mainly of Q(2) and Q(3) phosphate tetrahedral units. The Judd-Ofelt parameters (J-O) (Omega(2), Omega(4) and Omega(6)) were evaluated from the intensities of the energy levels through optical absorption spectra. The most intense transitions are observed in the visible region of the spectrum. It is observed that the transition I-5(8) -> (5)G(6) is the hypersensitive transition for Ho3+ ion. With these J-O parameters, various radiative properties like the probabilities of radiative transitions, radiative lifetimes and branching ratios have been calculated for different fluoro-phosphate glasses. The luminescence kinetics from excited holmium levels have been studied upon selective excitation through photoluminescence measurements. Holmium produces two visible laser emissions i.e. one is green (F-5(4)(S-5(2)) -> I-5(8)) and another one is red (F-5(5) -> I-5(8)). The lifetimes of these levels have been experimentally determined through decay profile studies. The above results suggest that the prepared bismuth fluorophosphate glass system could be a suitable candidate for using it as a green laser source (F-5(4)(S-5(2)) -> I-5(8)) in the visible region of the spectrum.4792634Sem informaçãoSem informaçãoSem informaçãoOne of the authors S. Babu would like to thank University Grants Commission (UGC), New Delhi for the sanction of Senior Research Fellowship (SRF) under Research Fellowship in Sciences for Meritorious students (RFSMS) scheme. Also thanks to SAIF IISc, Bangalore for providing solid state NMR facilities

Effect of ZnO on spectroscopic properties of Sm3+ doped zinc phosphate glasses

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSpectroscopic properties of Sm3+ containing zinc oxide based phosphate glasses in the chemical composition (50 - x)P2O5 + 20Na2HPO4 + 9AlF3 + xZnO + 1Sm2O3 (where x = 5, 10, 15, 20 and 25) have been studied. Raman, optical absorption, emission spectra and luminescence decay profiles were recorded and systematically analyzed. Using Judd-Ofelt theory, Judd-Ofelt intensity parameters Ωλ (λ = 2, 4 and 6), spontaneous radiative transition probabilities (Arad), radiative lifetimes (τR), branching ratios (β) were calculated and discussed. With 400 nmwavelength excitation, the emission spectra and decay lifetime of 4G52 level of Sm3+ doped zinc-phosphate glasses were studied. The branching ratios and emission cross-sections for the transition, 4G5/2→6H7/2 are found to be higher for x = 25 mol% of zinc-phosphate glass matrix. The observed decay profiles were found to be exhibiting non-exponential behavior for all zinc-phosphate glasses, due to non-radiative energy transfer among the excited Sm3+ ions.Spectroscopic properties of Sm3+ containing zinc oxide based phosphate glasses in the chemical composition (50−x)P2O5+20Na2HPO4+9AlF3+xZnO+1Sm2O3 (where x=5, 10, 15, 20 and 25) have been studied. Raman, optical absorption, emission spectra and luminescence decay profiles were recorded and systematically analyzed. Using Judd–Ofelt theory, Judd–Ofelt intensity parameters Ωλ (λ=2, 4 and 6), spontaneous radiative transition probabilities (Arad), radiative lifetimes (τR), branching ratios (β) were calculated and discussed. With 400 nm wavelength excitation, the emission spectra and decay lifetime of 4G52 level of Sm3+ doped zinc-phosphate glasses were studied. The branching ratios and emission cross-sections for the transition, 4G5/2→6H7/2 are found to be higher for x=25 mol% of zinc-phosphate glass matrix. The observed decay profiles were found to be exhibiting non-exponential behavior for all zinc-phosphate glasses, due to non-radiative energy transfer among the excited Sm3+ ions.4597987CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO190077/2013-1Jha, A., Richards, B., Jose, G., Teddy-Fernandez, T., Joshi, P., Jiang, X., Lousteau, J., (2012) Prog. Mater. Sci., 57, p. 1426Stoneman, R.C., Esterowitz, L., (1990) Opt. Lett., 15, p. 486Jackson, S.D., (2012) Nat. Photon., 6, p. 423Wang, P., Wang, Y.P., Tong, L.M., (2013) Light Sci. Appl., 2, p. e102Harbuzaru, B.V., Corma, A., Rey, F., Jordá, J.L., Ananias, D., Carlos, L.D., (2009) Angew. Chem. Int. Ed., 48, p. 6476Forster, Th., (1948) Ann. Phys., 2, p. 55Paulose, P.I., Jose, G., Thomas, V., Unnikrishnan, N.V., Warrier, M.K.R.J., (2003) Phys. Chem. Solids, 64, p. 841Joshi, B.C., Lohani, R., Pande, B., (2001) Indian J. Pure Appl. Phys., 39, p. 443Chen, B.J., Shen, L.F., Pun, E.Y.B., Lin, H., (2012) Opt. Express, 20, p. 879Lakshminarayana, G., Yang, R., Qiu, J.R., Brik, M.G., Kumar, G.A., Kityak, I.V., (2009) J. Phy. D: Appl. Phys., 42, pp. 015414+12Zang, J., Yang, D.L., Pun, E.Y.B., Gong, H., Lin, H., (2010) J. Appl. Phys., 107, p. 123111Elisa, M., Sava, B.A., Vasiliu, I.C., Monteiro, R.C.C., Veiga, J.P., Ghervase, L., (2013) J. Non-Cryst. Solids, 369, p. 55Song, H., Hayakawa, T., Nogami, M., (1999) J. Appl. Phys., 86, p. 5619Malchukova, E., Boizot, B., Petite, G., Ghaleb, D., (2007) J. Non-Cryst. Solids, 353, p. 2397Park, G.J., Hayakawa, T., Nogami, M., (2003) J. Phys.: Condens. Matter, 15, p. 1259Fuller, R.L., McClure, D.S., (1991) Phys. Rev. B, 43, p. 27Judd, B.R., (1962) Phys. Rev., 127, p. 75Ofelt, G.S., (1962) J. Chem. Phys., 37, p. 511Srinivasa Rao, Ch., Jayasankar, C.K., (2013) Opt. Commun., 286, p. 204Agarwal, A., Pal, I., Sanghi, S., Aggarwal, M.P., (2009) Opt. Mater., 32, p. 339Seshadri, M., Venkata Rao, K., Rao, J.L., Ratnakaram, Y.C., (2009) J. Alloys Compd., 476, p. 263Caldino, U., Speghini, A., Berneschi, S., Bettinelli, M., Brenci, M., Pelli, S., Righini, G.C., (2012) Opt. Mater., 34, p. 1067Rajesh, D., Balakrishna, A., Ratnakaram, Y.C., (2012) Opt. Mater., 35, p. 108Davis, E.A., Mott, N.F., (1970) Philos. Mag., 22, p. 903Moridi, G.R., Hogarth, C.A., Proceedings of the Seventh International Conference on Amorphous and Liquid Semiconductors, 1997, p. 688. , W.E. Spear (Ed.)Shimakawa, K., (1981) J. Non-Cryst. Solids, 43, p. 229Fares, H., Jlassi, I., Elhouichet, H., Férid, M., (2014) J. Non-Cryst. Solids, 396-397, p. 1Jlassi, I., Elhouichet, H., Ferid, M., (2011) J. Mater. Sci., 46, p. 806Shawoosh, A.S., Kutub, A.A., (1993) J. Mater. Sci., 28, p. 50Chen, G., Baccaro, S., Giorgi, R., Cecilia, A., Mihokova, E., Nikl, M., (2003) J. Non-Cryst. Solids, 326-327, p. 339Meyer, K., (1997) J. Non-Cryst. 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Acta A, 60, p. 637Jamalaiah, B.C., Suresh Kumar, J., Mohan Babu, A., Suhasini, T., Rama Moorthy, L., (2009) J. Lumin, 129, p. 363The author Y.C. Rathnakaram would like to thank the University Grants Commission (UGC) (No. F.40-443/2011(SR)), Delhi for financial support and M. Radha is greatful to TWAS-CNPq (No. 190077/2013-1)

Spectroscopic investigations on Ho3+ doped mixed alkali phosphate glasses

Optical absorption and emission properties of Ho3+ doped mixed alkali phosphate glasses of the type 69.5NH4H2PO4. xLi2-CO3.(30-x)K2CO3 and 69.5NH4H2PO4.xNa2CO3.(30-x)K2CO3 (where x = 5, 10, 15, 20 and 25) were studied. Racah (E1, E2,E3), spin–orbit (n4f) and configuration interaction (a, b) parameters are calculated and these values are compared for different x values in the glass matrix. Judd–Ofelt intensity parameters (X2, X4, X6) are calculated for all the Ho3+ doped mixed alkali phosphate glasses. From these parameters and from the spectral profiles of the hypersensitive transition structural studies have obtained. Radiative transition probabilities (A), radiative lifetimes (s), branching ratios (b) and integrated absorption cross-sections (R) are obtained from the intensity parameters. Emission cross-sections (r) are calculated for the two transitions, 5F4, 5S2? 5I8 and 5F5 ?5I8 of Ho3+ in these two mixed alkali phosphate glasses. Optical band gaps (Eopt) for both direct and indirect transitions are reported

Study of optical absorption, visible emission and NIR-vis luminescence spectra of Tm3+/Yb3+, Ho3+/Yb3+ and Tm3+/Ho3+/Yb3+ doped tellurite glasses

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOTm3+/Yb3+, Ho3+/Yb3+ co-doped and Tm3+/Ho3+/Yb3+ triply doped TeO2-Bi2O3-ZnO-Li2O-Nb2O5 (TBZLN) tellurite glasses were prepared by melt quenching method. Judd-Ofelt intensity parameters (Omega(lambda), lambda=2, 4 and 6), radiative transition probabilities, branching ratios and radiative lifetimes of Tm3+, Ho3+ ions in co-doped TBZLN glasses were calculated from the optical absorption spectra. Excitation, visible luminescence and decay lifetimes in visible region were also investigated. The stimulated emission and gain cross-sections for the Tm3+:F-3(4) -> H-3(6) (1700 nm) and Ho3+:I-5(7) -> I-5(8) (1956 nm) transitions in co-doped TBZLN glasses have been analyzed and compared with those of other reported glasses. Up-conversion luminescence was observed in TBZLN glasses under 980 nm laser excitation and energy transfer mechanisms have been discussed. Finally, CIE color co-ordinates were calculated and it is observed that the color co-ordinates fall in blue and green regions for Tm3+/Yb3+ and Ho3+/Yb3+ co-doped TBZLN glasses, respectively. A subsequent shift in color co-ordinates from green to greenish-yellow region has been observed with an increase in the concentration (0.1, 0.5 and 1.0 mol%) of Tm3+ ions in Tm3+/Ho3+/Yb3+ triply doped TBZLN glasses. (C) 2015 Elsevier B.V. All rights reserved.Tm3+/Yb3+, Ho3+/Yb3+ co-doped and Tm3+/Ho3+/Yb3+ triply doped TeO2-Bi2O3-ZnO-Li2O-Nb2O5 (TBZLN) tellurite glasses were prepared by melt quenching method. Judd-Ofelt intensity parameters (Omega(lambda), lambda=2, 4 and 6), radiative transition probabilities, branching ratios and radiative lifetimes of Tm3+, Ho3+ ions in co-doped TBZLN glasses were calculated from the optical absorption spectra. Excitation, visible luminescence and decay lifetimes in visible region were also investigated. The stimulated emission and gain cross-sections for the Tm3+:F-3(4) -> H-3(6) (1700 nm) and Ho3+:I-5(7) -> I-5(8) (1956 nm) transitions in co-doped TBZLN glasses have been analyzed and compared with those of other reported glasses. Up-conversion luminescence was observed in TBZLN glasses under 980 nm laser excitation and energy transfer mechanisms have been discussed. Finally, CIE color co-ordinates were calculated and it is observed that the color co-ordinates fall in blue and green regions for Tm3+/Yb3+ and Ho3+/Yb3+ co-doped TBZLN glasses, respectively. A subsequent shift in color co-ordinates from green to greenish-yellow region has been observed with an increase in the concentration (0.1, 0.5 and 1.0 mol%) of Tm3+ ions in Tm3+/Ho3+/Yb3+ triply doped TBZLN glasses.166816FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP [12/50480-6]FAPESP [2009/54066-7]2009/54066-7, 12/50480-6This work is financially supported by FAPESP, Grant # 12/50480-6. The authors would like to thank the Group of ultrafast phenomena and Optical Communications (GFURCO) and the Laboratory of Advanced Optical Spectroscopy (LMEOA//FAPESP Grant # 2009/54066-7) for providing lab facilities