Plasma crystal dynamics measured with a three-dimensional plenoptic camera.

Three-dimensional (3D) imaging of a single-layer plasma crystal was performed using a commercial plenoptic camera. To enhance the out-of-plane oscillations of particles in the crystal, the mode-coupling instability (MCI) was triggered in it by lowering the discharge power below a threshold. 3D coordinates of all particles in the crystal were extracted from the recorded videos. All three fundamental wave modes of the plasma crystal were calculated from these data. In the out-of-plane spectrum, only the MCI-induced hot spots (corresponding to the unstable hybrid mode) were resolved. The results are in agreement with theory and show that plenoptic cameras can be used to measure the 3D dynamics of plasma crystals.

[The significance of Campylobacter pylori infection in gastroenterologic and diabetic practice]. / Campylobacter pylori fertözés jelentösége a gasztroenterologiai és diabetologiai gyakorlatban.

The presence of Campylobacter pylori was investigated in gastric antral biopsy specimens. In 50 consecutive patients undergoing upper gastrointestinal tract endoscopy microbiological cultures, histological examination and rapid urease test were parallel performed, and a 92 per cent sensitivity and 100 per cent specificity of rapid and cheap urease test were determined. Afterwards--in a prospective study--311 patients were examined for C. p. by the rapid urease test only. C. p. was detected in 92 per cent of duodenal ulcer patients, in 52 per cent of patients with gastric ulcer, in 67 per cent of non-ulcer dyspepsia, in 62 per cent of mixed diabetic patient material, and in 21 per cent only of asymptomatic volunteers. It has been found by the authors, that the rate of C. p. infection increased parallel with the continuance of diabetes and did not follow the increasing with age as in the general population. This is the first observation in the world literature concerning the correlation between C. p. and diabetes mellitus. Very close, significant correlation has been found between C. p. infection and chronic active gastritis. C. p. may play an important role in the recurrences of duodenal ulcer and in the pathogenesis of non-ulcer and diabetic dyspepsia. Further studies are planned to the correct evaluation of pathogeneity of Campylobacter pylori.