Thermodynamische Analyse der Dehnung des elastischen Gewebes vom Standpunkt der statistisch-kinetischen Theorie der Kautschukelastizität.

Wöhlisch, Edgar; Weitnauer, Helmut; Grüning, Werner; Rohrbach, Rosemarie

doi:10.1007/bf01525811

Cited by 26 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…tained considerable amounts of collagen because the strips were faun~ to be perfectly reversible only up to 650, the temperat which native collagen exhibits thermal retraction , 27 (Gustavson, 1956;Piez and Gross, 1960). meyer and Ferri (1937) and Wohlisch et al (1943) showed that untreat~d ligamentum nuchae, when 100% extended, conformed to elastomeric theory by contracting when heated. Because of an apparent increase in internal energy when extended, meyer and Ferri concluded that crystallization took place at large extensions • .…”

Section: ~;mentioning

confidence: 90%

Mechanical properties of arteries

Dobrin¹

1978

Physiological Reviews

668

400

View full text Add to dashboard Cite

Section: ~;mentioning

confidence: 90%

Mechanical properties of arteries

Dobrin¹

1978

Physiological Reviews

668

400

View full text Add to dashboard Cite

“…The common theory is that axial elongation of elastic fibres accounts for the elasticity of the lung, and many experiments have led towards or from that assumption. Elastin has a large range of extensibility, a low modulus of elasticity, and exhibits ideal elastic behaviour (Meyer and Ferri, 1936;Wohlisch, Weitnauer, Gruning, and Rohrbach, 1943) without crystallization at any elongation (Hoeve and Flory, 1958). The total elastic performance of the airfilled lung, however, cannot be accounted for by elastic tissue, although occasionally this has been inferred (Lawton and Joslin, 1951).…”

Section: Discussionmentioning

confidence: 99%

Fibrous Network of the Lung and its Change with Age

Pierce¹,

Ebert²

1965

Thorax

View full text Add to dashboard Cite

The remarkable elastic behaviour of the lung entails both continuous tissue stress and a cyclic stress produced by the fluctuating difference between intrathoracic and intra-alveolar pressures throughout the entire span of life. In spite of these potentially disruptive forces, lung structure is preserved by the fibrous connective-tissue proteinscollagen, elastin, and reticulin. These extracellular proteins are characterized by their insolubility, resistance to destruction, and high tensile strength. Collagen and elastin both exhibit elastic behaviour, but great extensibility is a property only of elastin. The most reasonable assumption is that the elastic fibres, therefore, are principally responsible for the elastic behaviour of the lung tissue, but sure proof is lacking.Recently, Carton, Dainauskas, Tews, and Hass (1960) and Wright (1961) have described the nature of the network of elastic tissue in the lung. We sought to describe more fully the roles of collagenous and elastic fibres in the terminal air spaces of the lung, and thus their respective contributions to tissue elasticity and the general elastic performance of the lung. As the study developed, it seemed important to measure the amounts of collagen and elastin in the lung parenchyma and pleura. These findings have been correlated with the age of the subjects and interpreted according to knowledge about tissue elasticity. METHODSThe study was based on 36 human lungs taken from patients who had died of a variety of diseases. No lungs were taken from patients with a history of cough, sputum production, dyspnoea, or chronic pulmonary disease, or from patients whose clinical history was incomplete. Of these 36, 27 lungs were dried in an inflated state by the extraction process using dilute (0-1 N) sodium hydroxide solution (Pierce, Hocott, and Ebert, 1959). Nine more lungs were also dried in the inflated state but were fixed with formalin vapour. The advantage of the alkaline extraction method is that it permits the morphology of the lung 1 Supported in part by grants HTS5333 and HE04031 from the U.S. Public Health Service to be examined and also the quantities of collagen and elastin to be measured.The lungs were cut into thin slices and examined grossly and with a stereomicroscope. Slices of tissue were variously stained (Lillie, 1954) but not embedded. Elastic tissue was stained by the Taenzer-Unna acidorcein method (in absolute ethanol); Van Gieson's picric acid-acid fuchsin mixture was used to stain collagen; and Fraenkel's method of using orcein and indigo-carmine was employed to stain both collagen and elastin in the same slice. All slices were rapidly dehydrated in alcohol and then in ether, and dried in vacuo to prevent collapse. This procedure enabled one to study the structure of the alveoli, alveolar ducts, and respiratory bronchioles as well as to visualize the relationship of the fibres in three dimensions. Preparations extracted with sodium hydroxide provided a more clearly defined fibrous network than did the formalin-vapour preparation...

show abstract

“…On the basis of stress-temperature measurements Meyer and Ferri (4) and Wohlisch et al (5) proposed that elastin crystallizes on stretching. Hoeve and Flory (6) performed stress-temperature measurements in suitably chosen solvent mixtures and showed that elastin does not crystallize on stretching; instead they proposed that the molecular basis for the elasticity is the retractive force resulting from deformation of a network of crosslinked amorphous chains.…”

mentioning

confidence: 99%

The glass point of elastin.

Kakivaya¹,

Hoeve²

1975

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Elastin undergoes a glass transition in a temperature range that depends on its water content. This behavior is similar to that of amorphous polymers swollen with solvent and, therefore, is additional evidence for the random network model proposed for the structure neous connective tissue, cut into thin strips, and washed several times with distilled water. In order to remove collagen, they were autoclaved in water at 120°for 12 hr and thoroughly washed. Subsequently, they were dried at 700 for over a week and stored over P205. The samples did not lose any further weight on drying at 1000 under reduced pressure. The strips were chopped into small pieces for the heat capacity and absorption measurements.For the heat capacity determinations, 5-10 mg of sample was placed in small aluminum pans. After the sample was weighed on a microbalance, a suitable amount of water was added with a microsyringe and an aluminum cover was placed on the pan. By exerting pressure the pan was crimped shut. The amount of added water was determined by another weighing. The heat capacity was recorded on a Perkin-Elmer Differential Scanning Calorimeter model 1-B. First the amplitude was recorded with empty aluminum pans in the sample and reference holders. Sample pans with various amounts of water (4-10 mg) were then placed in the sample holder and the amplitude was recorded at a scanning rate of 5 deg min-1. From the value of the specific heat of water of 1.00 cal deg'1 g-' and the amplitudes, the calibration constant was obtained. Scanning over the same temperature range was carried out with the elastin samples containing various amounts of water in the range of 0-0.6 g of water per gram of dry elastin. From the calibration constant, the values of the amplitudes, and the weights, the heat capacities of the elastin samples were calculated. The glass transition of samples was observed by raising the temperature 50/min from well below the glass point to well above it. The inflection point in the S-shaped curve obtained was taken as the glass point. For detection of any ice formed, the samples were cooled from 200 to -250 at a rate of 2.5°/ minute. Subsequently, the heat capacity was measured by scanning from -250 through the melting point of ice at a rate of 0.6250/min. A large peak indicated the melting of ice.A thin strip of elastin of about 3 cm in length and 0.02 cm2 in cross section was used for measurement of the mechanical properties. A weight of 100 g was suspended from the strip, which was then exposed to a constant relative humidity at 200. After a week the distance between two fiducial marks placed on the strip was measured with a cathetometer. Subsequently, the fiber was dried and the procedure was repeated with a higher relative humidity.For the conductivity measurements a thin strip of about 3 cm in length and 0.02 cm2 in cross section was coated on both ends with conductive epoxy glue. The sample was then exposed to a constant relative humidity at 200 and the resistance between the ends was measured. The electric ...

show abstract

Thermodynamische Analyse der Dehnung des elastischen Gewebes vom Standpunkt der statistisch-kinetischen Theorie der Kautschukelastizität.

Cited by 26 publications

References 12 publications

Mechanical properties of arteries

Mechanical properties of arteries

Fibrous Network of the Lung and its Change with Age

The glass point of elastin.

Contact Info

Product

Resources

About