Iridium
Mostrando 37-42 de 42 artigos, teses e dissertações.
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37. Chicxulub impact predates the K-T boundary mass extinction
Since the early l990s the Chicxulub crater on Yucatan, Mexico, has been hailed as the smoking gun that proves the hypothesis that an asteroid killed the dinosaurs and caused the mass extinction of many other organisms at the Cretaceous-Tertiary (K-T) boundary 65 million years ago. Here, we report evidence from a previously uninvestigated core, Yaxcopoil-1, d
National Academy of Sciences.
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38. Treatment of primary breast cancer without mastectomy. The Los Angeles community experience and review of the literature.
Between 1977 and 1983, 150 women with primary breast cancer, ranging in age from 26 to 84, were treated with a breast-sparing procedure involving lumpectomy, axillary node dissection, external beam radiotherapy, and 192-iridium implant. Median follow-up to date is 46+ months, with a range of 14 to 96+ months. All surviving patients have been followed for a m
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39. Analysis of failure after curative irradiation of extrahepatic bile duct carcinoma.
Thirty-four patients with subtotally resected or unresectable carcinoma of the extrahepatic bile ducts received radiation therapy; a minimum of 45 Gy (external beam) to the tumor and regional lymph nodes +/- 5-fluorouracil (5-FU). Seventeen patients received an external beam boost of 5 to 15 Gy to the tumor, and a specialized boost was used in the remaining
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40. Metal clusters in catalysis: Hydrocarbon reactions*
A set of metal carbonyl clusters, Ru3(CO)12, Os3(CO)12, and Ir4(CO)12, has been evaluated as catalysts for a series of hydrocarbon reactions which comprise skeletal rearrangement, metathesis, dehydrogenation, hydrogenation, isomerization, and H-D exchange. None was especially effective as a hydrogenation catalyst even for olefins. Os3(CO)12 was a catalyst fo
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41. Effects of cis-Dichlorodiammineplatinum (II) and Related Transition Metal Complexes on Escherichia coli
A number of transition metal complexes, including the cis and trans isomers of dichlorodiammineplatinum (II), six complexes of rhodium (I), two of iridium (I), and one of ruthenium (II) have been tested for their ability to induce lambda prophage, to produce filamentous growth of Escherichia coli, and to be selectively toxic for strains with defects in the d
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42. 129Xe on Ir(111): NMR study of xenon on a metal single crystal surface
NMR experiments of 129Xe adsorbed on an iridium single crystal surface are reported. Very high nuclear polarization (Pz ≈ 0.7) makes the experiment possible. A coverage of less then one monolayer is investigated on the Ir(111) surface with an area of 0.8 cm2. The observed resonance line shifts are very large and highly anisotropic. We find σiso = 1,032 ±
National Academy of Sciences.