Nonlinear waves in solids with slow dynamics: an internal-variable model.

In heterogeneous solids such as rocks and concrete, the speed of sound diminishes with the strain amplitude of a dynamic loading (softening). This decrease, known as 'slow dynamics', occurs at time scales larger than the period of the forcing. Also, hysteresis is observed in the steady-state response.

A time-domain numerical modeling of two-dimensional wave propagation in porous media with frequency-dependent dynamic permeability.

An explicit finite-difference scheme is presented for solving the two-dimensional Biot equations of poroelasticity across the full range of frequencies. The key difficulty is to discretize the Johnson-Koplik-Dashen (JKD) model which describes the viscous dissipations in the pores. Indeed, the time-domain version of Biot-JKD model involves order 1/2 fractional derivatives which amount to a time convolution product.

Effect of edentulism on spirometric tests.

The impact of denture wear in edentulous subjects while performing routine spirometric measurements has never been systematically investigated. We compared the values of FVC, FEV(1), PEFR, FEF(50%), FIV(1), and FIF(50%) recorded with and without dentures in three groups of edentulous subjects: 36 asymptomatic subjects with normal spirometry (N), 22 patients with chronic obstructive pulmonary disease (COPD), and 18 with interstitial lung disease (ILD). In 14 subjects retropharyngeal space with and without dentures was assessed by cephalometry.

Exhaled nitric oxide in systemic sclerosis: relationships with lung involvement and pulmonary hypertension.

Objective: To measure nitric oxide (NO) concentration in exhaled air of patients with systemic sclerosis (SSc) and to investigate its relationships with lung involvement, complicated or not by pulmonary hypertension (PH).

Methods: Exhaled NO was measured by chemiluminescence in 47 patients with SSc (16 with PH) and in 30 controls. All the patients underwent Doppler echocardiography to assess pulmonary artery pressure (PAP), lung function tests, and thin section computed tomographic scans of the lung to quantify the extent of fibrosing alveolitis.

Changes in airway responsiveness following mantle radiotherapy for Hodgkin's disease.

Unlabelled: STUDY OBJECTIVES To investigate whether mantle radiotherapy (MRT) for the lung, through its proinflammatory effects, can induce an increase in airway responsiveness.

Design: Follow-up of the changes in lung function and methacholine responsiveness in patients 1, 6, 12, and 24 months after they underwent MRT.

Patients: Thirteen nonasthmatic patients with bulky Hodgkin's lymphoma who were scheduled for MRT.