Search results for "Elastic membrane"
showing 4 items of 4 documents
Calcification patterns of the internal elastic membrane
1969
Calcification patterns of the internal elastic membrane of the main pelvic arteries, lower limb arteries, brachial, splenic and renal arteries were demonstrated grossly by a modified von Kossa technique. In the elastic segment in the common and internal iliac arteries, the membrane calcification appeared as groups of roundish or polygonal incrustations. They were found frequently in newborns, and were always present in infants of more than three months, as well as in adults. In the muscular arteries, the calcified parts of the internal elastic membrane appeared grossly as pairs of bands (“calcific bands”) along the edges of the pre-existing gaps in this membrane. When calcification was pron…
Verkalkungsformen der inneren elastischen Membran der Beinarterien und ihre Bedeutung f�r die Mediaverkalkung
1967
Mikroradiographische und histologische Untersuchungen an Flachschnitten der Innenwand der Beinarterien in 30 FAllen (2–49 Jahre) ergaben als Fruhform der Mineralisation des Arterienrohres eine bandformige Verkalkung der inneren elastischen Membran an den Begrenzungen ihrer vorgebildeten, vorwiegend zirkulAr orientierten Spalten. Diese Form der Verkalkung (paarweise verlaufende „KalkbAnder“) fand sich an der A. femoralis und A. poplitea regelmA\ig bereits in der 2. Lebensdekade. Mit Abschlu\ des Korperwachstums erreichen die KalkbAnder hAufig eine erhebliche Ausbreitung. Durch Verbreiterung und Konfluenz der KalkbAnder konnen „Kalkfolien“ entstehen, die streckenweise die gesamte innere elast…
Early calcification patterns of the iliac arteries and their relation to the arterial structure
1972
Gross calcifications of the common iliac and internal iliac arteries represent a common finding in newborn children and infants. In both arteries, the calcific deposits regularly appear in certain areas of the arterial luminal surface only, whereas the other parts of the arterial wall remain free of gross lesions even in cases with a pronounced calcification. In the common iliac artery, the lateral wall of the vessel and the adjacent sectors of the anterior and posterior wall represent the predilection site of calcific deposits. In the internal iliac artery, the gross calcifications have been regularly demonstrated in the dorso-medial wall. The predominant localisation of the calcification …
Deterministic folding in stiff elastic membranes.
2008
Crumpled membranes have been found to be characterized by complex patterns of spatially seemingly random facets separated by narrow ridges of high elastic energy. We demonstrate by numerical simulations that compression of stiff elastic membranes with small randomness in their initial configurations leads to either random ridge configurations (high entropy) or nearly deterministic folds (low elastic energy). For folding with symmetric ridge configurations to appear in part of the crumpling processes, the crumpling rate must be slow enough. Folding stops when the thickness of the folded structure becomes important, and crumpling continues thereafter as a random process.