Remarkable microfungi from Oaxaca (Mexico) of Acacia species.

In the state of Oaxaca (Mexico, 10 km north-west of Puerto Escondido 15 degrees 55' N, 97 degrees 09' W) we were able to collect some microfungi living as parasites or saprophytes on Acacia species, some of them are causing attention for Oaxaca. Many belong to the Deuteromycotina (Hyphomycetes, Coelomycetes) and Ascomycotina. On A.

Effects of chromophore dissociation on the optical properties of rare-Earth-doped polymers.

The observed dissociation of tetrakis rare-earth chromophores in rare-earth-doped organic polymers is reported, and a time-resolved spectroscopic technique is presented to determine quantitatively the fractional concentrations of different chromophore species in various solvents. Based on this technique, the equilibrium constants of tetrakis rare-earth chromophores in rare-earth-doped polymers are determined. Thus, the equilibrium constants for tetrakis rare-earth compounds of benzoyltrifluoroacetonate (BTF), for example, Sm(BTF)(4)P and Eu(BTF)(4)P in methyl methacrylate monomer, are K = 4.

Prognostic significance of vascular and perineural invasion in urothelial bladder cancer treated with radical cystectomy.

Purpose: Data on the prognostic significance of tumor invading lymphatic and blood vessels in bladder cancer are controversial, while little is known about perineural invasion in this tumor. We determined the prognostic value of these parameters in radical cystectomy specimens.

Materials And Methods: Slides of 283 radical cystectomy specimens obtained from 1986 to 1997 were examined retrospectively with respect to tumor invasion in lymphatic and blood vessels, and perineural spaces.

Room-temperature green upconversion fluorescence of an Er(3+)-doped laser liquid.

Room-temperature green upconversion fluorescence of an Er(3+)-doped POCl(3)-SnCl(4) solution is achieved when the solution is pumped with an 800-nm GaAs laser diode. The upconversion emission at 550 nm is determined to be the result of a two-step absorption process. Numerical analysis reveals that laser systems that employ this erbium-doped laser liquid should be realizable with threshold pump powers as low as 45 mW.