Lingual ulceration.
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Carcinoma, Squamous Cell↗
Biomedical subjects
E Leyva
Publications and source records attributed to E Leyva.
The photochemistry of iodo, methyl and thiomethyl substituted aryl azides in toluene solution and frozen polycrystals.
The photolysis of para-methyl and para-thiomethylphenylazide at 77 K produces the corresponding triplet nitrenes which can be detected by electron paramagnetic resonance (EPR) spectroscopy. Photolysis of these azides in frozen toluene at 77 K leads to insertion of the nitrene into a benzylic C-H bond of the matrix in modest yields. Photolysis of iodinated aryl azides under these conditions does not produce triplet nitrenes that can be detected by EPR spectroscopy. In contrast to the para-methyl and para-thiomethyl substituted phenyl nitrenes, photo-induced coupling of iodo-substituted phenyl nitrenes to toluene proceeds in very poor yield.
Azides↗
[Induction of "sterile" periapical lesions in rodents. Preliminary report].
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Animals↗
[Cleft lip and palate in Campeche Mayas].
It has been suggested that among American Indians, as in some genetically-related Asiatic ethnic groups, incidence of cleft lip and/or cleft palate is higher than among people of Caucasian extraction. Such hypothesis, plus growing demand for services observed at a center for the surgery of cleft lip and cleft palate in Campeche state, led the authors to undertake research among the Maya residents of that region. However, neither careful review of case histories nor field research performed in several Indian communities could confirm the hypothesis of a higher incidence among this ethnic community.
Cleft Lip↗
[Immunologic factors in the etiopathogenesis of periapical granulomas].
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Dental Pulp Cavity↗
Exploratory photochemistry of fluorinated aryl azides. Implications for the design of photoaffinity labeling reagents.
A series of fluorinated aryl azides and fluorinated azidobenzoates were studied by laser flash photolysis techniques. Using the pyridine ylide probe method it was possible to determine whether a singlet nitrene or ring-expanded ketenimine ylide is the trappable intermediate that is generated at ambient temperature. It was determined that two fluorine substituents, ortho and ortho' substituted relative to the azide group, are required to retard ring expansion and allow bimolecular capture of the singlet nitrene. LFP of ortho, ortho' difluorinated aryl azides in methanol produces the ground triplet state of the nitrene. The results are consistent with chemical analysis of reaction mixtures. The implications of this data for the design of photoaffinity labeling reagents are discussed.
Affinity Labels↗