52 research outputs found
Biologically Active Compounds. II. The Synthesis of β-CarboxY-γ-butyrolactone Derivatives
Amide derivatives of γ-substituted paraconic and aconic acids have been synthesized. Ultraviolet spectra of the aconic acid derivatives showed characteristic fine structure in the region of 245 to 280 mμ
Effects of formaldehyde, as an indoor air pollutant, on the airway
ABSTRACTHomes are being built to be more airtight because of demands for energy conservation in recent years. At the same time, recognition of numerous sources of formaldehyde in indoor environments has increased concerns about health hazards from this pollutant. Formaldehyde has been shown to cause and exacerbate asthmatic symptoms. In addition, the effects of formaldehyde on the airway are proportional to the concentration and duration of exposure and are greater in inflamed than in healthy airways. Formaldehyde may induce features of airway inflammation associated with asthma, such as epithelial disruption, microvascular leakage and increased airway secretions. Exposure to this chemical may facilitate IgE sensitization to a variety of allergens, as well as producing IgE-mediated allergic responses to itself. Thus, avoidance of formaldehyde exposure may reduce the incidence and severity of asthma, although the ability of low concentrations of formaldehyde to trigger mechanisms contributing to asthmatic symptoms is still debated. Setting appropriate exposure limits for formaldehyde as an indoor environmental pollutant requires further quantitative and predictive evaluation of its health effects
Hilbert and Hadamard transforms by generalized Chebyshev expansion
AbstractAn automatic quadrature is presented for approximating Hadamard finite-part (fp) integrals of a smooth function, with a double pole singularity within the range of integration. The quadrature rule is derived from the differentiation of an approximation to a Cauchy principal value integral or the Hilbert transform. The approximation to the fp integral is represented as a function of the value of pole by using Chebyshev polynomials of the second kind. Since the error can be estimated independently of the value of pole, a set of integrals for a set of values of pole can be efficiently approximated to a required tolerance, with the same number of function evaluations. Numerical examples are also included to illustrate the performance of the methods
Cross-allergenicity between Aspergillus restrictus, Aspergillus fumigatus and Alternaria alternata determined by radioallergosorbent test inhibition
Aspergillus restrictus, an osmophilic fungus, is abundant in house dust. We have shown previously that the incidence of immediate hypersensitivity to A. restrictus is comparable to that for Aspergillus fumigatus and Alternaria alternata in asthmatic children. Radioallergosorbent test (RAST) inhibition was used to determine whether A. restrictus shares similar allergenic components with A. fumigatus and A. alternata. Mycelial mats of the three species cultivated on completely synthetic media were used for extract preparation. IgE antibodies to each fungus were measured with RAST using a polyvinyl chloride microplate as a solid phase. Analysis of a serum pool obtained from nine asthmatic children with a positive RAST to A. restrictus showed that A. restrictus inhibited the RAST to A. restrictus, A. fumigatus and A. alternata by more than 80%. Similar results were observed with A. fumigatus and A. alternata. Additionally, when 13 serum samples with a positive RAST to A. restrictus were tested separately, A. restrictus substantially inhibited the A. restrictus RAST in all subjects tested. A. fumigatus and A. alternata inhibited the A. restrictus RAST in 10 and 8 of the samples studied, respectively. These findings indicate that A. restrictus shares allergenic components with A. fumigatus and A. alternata. The allergenic cross-reactivity between A. fumigatus and A. alternata was also demonstrated
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