Experimental observation of quantum reflection far from threshold.

We present first experimental evidence for quantum reflection, originating exclusively from an attractive potential between an atom and a solid surface, at energies far from the threshold E(i)-->0. The system of light and stable 3He atoms scattering from an alpha-quartz crystal allows confirmation of recent theory on quantum reflection up to its asymptotic behavior, determined by the nonretarded van der Waals potential -C(3)/r(3). From the data, the gas-solid interaction potential is deduced quantitatively, covering the energy region, in which retardation plays a role.

[Radiographic evaluation of the clinical course and outcome in acute pneumonias].

The authors review the data of x-ray functional examinations of 525 patients with acute parenchymatoys pneumonia, 393 convalescents after pneumonia 3-6 months after the disease and analyze 480 case histories of patients, hospitalized for acute pneumonia 10 years ago. Development, x-ray picture, and resolution of the process are described. Besides traditional x-ray examination, roentgenography in oblique projections and pulmonary sonography are recommended in order to specify the anatomic changes in the lungs.