A liquid polyisocyanurate (PIR) containing isocyanate prepolymer was synthesized via co-cyclotrimerization of mono- and di-isocyanates used for preparation flexible elastomers with good thermal stability tunable mechanical properties.

162 subjects who had been exposed to isocyanates, who had developed symptoms during the exposure period, or in the evening or night and, therefore, had a history compatible with isocyanate-induced asthma, were studied with inhalation challenge testing to isocyanates (toluene diisocyanate and methylene diphenyl diisocyanate) and methacholine, because they were suspected of having occupational as...

BACKGROUND Inhalation challenges are used for diagnosing occupational asthma (OA). The initial methodology consisted of a "realistic" exposure without monitoring nor controlling exposure. Our aim was to design an equipment, called the GenaSIC, that allows the generation of various agents regardless of the formulation and to assess the feasibility of its use in patients investigated for OA. RE...

The effects of 1,3-bis(2-chloroethyl)-1-nitrosourea, 1-(2-chloroethyl)-3-cyclohexl-1-nitrosourea, and 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea on two nonmitochondrial DNA polymerases (I and II) purified from rat liver and hepatoma were examined. The activity of DNA polymerase I was not altered by treatment with any of the nitrosoureas or the corresponding isocyanates, 2-chlo...

The polymerization of N-carboxyglycine anhydride has been used to identify potential inhibitors of protein synthesis and hence of cancers. Polymerization inhibition was observed wi th N-me thylbis(2.chloroethyl)amine HC1, busulfan, I ,9-dimethylsulfonyloxynonane, phenyl isocyanate, etc. (14), tris(2-chloroethyl)amine HC1 (7), and chiorambudil (G. E. Moos and J. B. Morrison, unpublished data). I...

Fluorine substituents in the phenyl ring of methyl fluorophenyl carbamates and fluorophenyl isocyanates were varied to determine the influence of fluorine substituents on fungal resistance of wood containing them. In southern pine impregnated with methyl fluorophenyl carbamates, increased fluorine substitution of the phenyl ring increased fungal resistance. Methyl pentafluorophenyl carbamate an...

Hydrolyzable polymers are widely used materials that have found numerous applications in biomedical, agricultural, plastic, and packaging industrials. They usually contain ester and other hydrolyzable bonds, such as anhydride, acetal, ketal, or imine, in their backbone structures. Here, we report the first design of hydrolyzable polyureas bearing dynamic hindered urea bonds (HUBs) that can reve...