1,169 research outputs found
Synthesis And Structural Characterization Of The Mixed-metal Species [co2ir2(co)10(η4-cod)] And [coir3(co)10(η4-cod)] (cod = 1,5-cyclooctadiene)
No full textThe new mixed-metal clusters [CO2Ir2(CO)10(cod)] (4) and [CoIr3(CO)10(cod)] (5) (cod = 1,5-cyclooctadiene) have been obtained from [CO2(CO)8](2) and [IrCl(Cod)2] (3). Alternatively, [CO2Ir2(CO)12] (1) reacts with cod to yield 4, which in the presence of CO reforms 1. Under the same conditions, however, 5 is inert. The solid state structures of 4 and 5 have been established by X-ray analyses, and the disorder shown by the two species is discussed. Compound 4 is monoclinic, space group P21/c, a 8.891(2), b 10.746(3), c 22.648(8) Å, β 95.16(3)°, Z = 4, R = 0.048, R′= 0.050, for 2393 [I ≫ 2σ(I)] of 2596 absorption corrected reflections; compound 5 is also monoclinic, space group P21/m, a 8.5994(9), b 12.047(3), c 10.799(3) Å, β 98.30(1)°, Z = 2, R = 0.037, R′= 0.040, for 2071 [I ≫ 2σ(I)] of 2711 absorption corrected reflections. © 1993.45201/02/15197203Stuntz, Shapley, Pierpont, (1978) Inorg. Chem., 17, p. 2596Pierpont, (1979) Inorg. Chem., 18, p. 2972Ros, Canziani, Roulet, (1984) J. Organomet. Chem., 267, p. C9Braga, Ros, Roulet, (1985) J. Organomet. Chem., 286, p. C8Ros, Scrivanti, Roulet, (1986) J. Organomet. Chem., 303, p. 273Kitamura, Joh, (1974) J. Organomet. Chem., 65, p. 235Martinengo, Chini, Albano, Cariati, Salvatori, (1973) J. Organomet. Chem., 59, p. 379Albano, Ciani, Martinengo, (1974) J. Organomet. Chem., 65, p. 265Labroue, Queau, Poilblanc, (1982) J. Organomet. Chem., 233, p. 359Eshtiagh-Hosseini, Nixon, (1978) J. Organomet. Chem., 195, p. 129Carré, Cotton, Frenz, Preparation and structure of a new derivative of tetrarhodium dodecacarbonyl. Further refinement of the structure of tetracobalt dodecacarbonyl (1976) Inorganic Chemistry, 15, p. 380Churchill, Hutchinson, (1978) J. Organomet. Chem., 17, p. 5328Braga, Grepioni, (1987) J. Organomet. Chem., 336, p. C9Strawczynski, Ros, Roulet, Grepioni, Braga, Intramolecular Dynamics of Tetranuclear Carbonyliridium Cluster Compounds. Part II. Disubstituted complexes with one chelating ligand. Crystal structure of [Ir4(CO)7(?-CO)3(1,5-cyclooctadiene)] (1988) Helvetica Chimica Acta, 71, p. 1885Braga, Grepioni, Guadalupi, Scrivanti, Ros, Roulet, (1987) Organometallics, 6, p. 56Herde, Lambert, Senoff, (1974) Inorg. Synth., 15, p. 18Sheldrick, (1976) System of Computer Programs, , SHELX76, University of CambridgeWalker, Stuart, An empirical method for correcting diffractometer data for absorption effects (1983) Acta Crystallographica Section A Foundations of Crystallography, 39, p. 15
Marginal quality of posterior microhybrid resin composite restorations applied using two polymerisation protocols: 5-year randomised split mouth trial
No full textOBJECTIVES: This randomised, split-mouth clinical study evaluated the marginal quality of direct Class I and Class II restorations made of microhybrid composite and applied using two polymerisation protocols, using two margin evaluation criteria.
METHODS: A total of 50 patients (mean age: 33 years) received 100 direct Class I or Class II restorations in premolars or molars. Three calibrated operators made the restorations. After conditioning the tooth with 2-step etch-and-rinse adhesive, restorations were made incrementally using microhybrid composite (Tetric EvoCeram). Each layer was polymerised using a polymerisation device operated either at regular mode (600-650 mW/cm(2) for 20s) (RM) or high-power (1200-1300 mW/cm(2) for 10s) mode (HPM). Two independent calibrated operators evaluated the restorations 1 week after restoration placement (baseline), at 6 months and thereafter annually up to 5 years using modified USPHS and SQUACE criteria. Data were analyzed using Mann-Whitney U-test (α=0.05).
RESULTS: Alfa scores (USPHS) for marginal adaptation (86% and 88% for RM and HPM, respectively) and marginal discoloration (88% and 88%, for RM and HPM, respectively) did not show significant differences between the two-polymerisation protocols (p>0.05). Alfa scores (SQUACE) for marginal adaptation (88% and 88% for RM and HPM, respectively) and marginal discoloration (94% and 94%, for RM and HPM, respectively) were also not significantly different at 5th year (p>0.05).
CONCLUSION: Regular and high-power polymerisation protocols had no influence on the marginal quality of the microhybrid composite tested up to 5 years. Both modified USPHS and SQUACE criteria confirmed that regardless of the polymerisation mode, marginal quality of the restorations deteriorated compared to baseline
A new approach for estimating northern peatland gross primary productivity using a satellite-sensor-derived chlorophyll index
No full textCarbon flux models that are largely driven by remotely sensed data can be used to estimate gross primary productivity (GPP) over large areas, but despite the importance of peatland ecosystems in the global carbon cycle, relatively little attention has been given to determining their success in these ecosystems. This paper is the first to explore the potential of chlorophyll-based vegetation index models for estimating peatland GPP from satellite data. Using several years of carbon flux data from contrasting peatlands, we explored the relationships between the MERIS terrestrial chlorophyll index (MTCI) and GPP, and determined whether the inclusion of environmental variables such as PAR and temperature, thought to be important determinants of peatland carbon flux, improved upon direct relationships. To place our results in context, we compared the newly developed GPP models with the MODIS (Moderate Resolution Imaging Spectrometer) GPP product. Our results show that simple MTCI-based models can be used for estimates of interannual and intra-annual variability in peatland GPP. The MTCI is a good indicator of GPP and compares favorably with more complex products derived from the MODIS sensor on a site-specific basis. The incorporation of MTCI into a light use efficiency type model, by means of partitioning the fraction of photosynthetic material within a plant canopy, shows most promise for peatland GPP estimation, outperforming all other models. Our results demonstrate that satellite data specifically related to vegetation chlorophyll content may ultimately facilitate improved quantification of peatland carbon flux dynamics
Is the Endodontic Temporary Filling Compromising Your Success?
No full text Leakage in Roots Coronally Sealed with Different Temporary Fillings. C.R. Barthel, A. Strobach, H. Briedigkeit, U.B. Göbel, J-F. Roulet. Journal of Endodontics 1999; 25: 731-734. </jats:p
14-18, La Terre et le Feu, 2018
No full textSouscription La Terre et le Feu, prolongation de la souscriptionTélécharger La Terre et le Feu Géologie et géologues sur le front occidental - Table des matièresTélécharger Bergerat F. (dir.) avec la collaboration de P. Gaviglio, J.P. Gély, N. Ginsburger, J. Labourguigne, P. Le Vigouroux, J. Lorenz et M.J. Roulet (éds) (2018) – 14-18, La Terre et le Feu. Géologie et géologues sur le front occidental. Co-édition AGBP - COFRHIGÉO - SGN, Mém. hors-série n°10 de l’AGBP, 480 p., 355 illustration
Is composite at the end of development? Wishes of clinicians versus technical possibilities.
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