Methacholine inhalation challenge in young children: results of testing and follow-up.

The diagnosis of asthma is often difficult in young children because their symptoms may not be typical and pulmonary function testing cannot be performed by the patient. We therefore performed methacholine inhalation challenges (MIC) in 24 patients 1 to 5.8 years of age in whom the diagnosis of asthma was uncertain.

Coal science: basic research opportunities.

More fundamental knowledge of coal (knowledge of its structure and its behavior during conversion processes) is essential before we can generate new technologies necessary for the efficient use of coal in the future. Herein are suggested specific basic research opportunities in the areas of coal characterization, gasification, combustion, and liquefaction, along with an assessment of the impact such research programs could have. Critical characterization needs include qualitative and quantitative determination of the chemical forms of carbon, oxygen, nitrogen, and sulfur and reliable methods for the measurement of surface area, pore volume, and weight-average molecular weights.