Search Results - (Author, Cooperation:M. Zech)

2014-05-09

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

article

2013

Pädagogik ; Waldorfpädagogik ; Erziehungsziel ; Bildungsgeschichte ; Schulgeschichte ; Waldorfschule ; Geschichte (Histor) ; Erkenntnistheorie ; Internationale Zusammenarbeit ; 20. Jahrhundert ; 21. Jahrhundert ; Gründung ; Selbstverständnis ; Verbreitung ; Vereinigung ; Steiner, Rudolf ; Mitteleuropa ; Osteuropa ; Ukraine

Barz, Heiner (Hrsg.), Unterrichten an Waldorfschulen. Berufsbild Waldorflehrer. Neue Perspektiven zu Praxis, Forschung, Ausbildung., Wiesbaden: Springer Fachmedien (2013), S. [19]-51, 978-3-658-00550-4

German

Literaturangaben S. 48-51

article

2020

Waldorfpädagogik ; Kultureinfluss ; Waldorfschule ; Schüler ; Interkulturalität ; Lehrplan ; Geschichte (Histor) ; Geschichtsphilosophie ; Geschichtsunterricht ; Multiperspektivität ; Migrationshintergrund ; Kultureller Unterschied ; Narration ; Vielfalt ; Deutschland

Erziehungskunst, Bd. 84 (2020) H. 10, S. 30-35, 0014-0333

0041-0333

German

article

2022

Waldorfpädagogik ; Elementarstufe ; Sekundarstufe I ; Sekundarstufe II ; Waldorfschule ; Lehrplan ; Geschichtsunterricht ; Kulturgeschichte ; Kulturelle Bildung ; Bewusstheit ; Diskurs ; Globales Denken ; Deutschland

Erziehungskunst, Bd. 86 (2022) H. 4, S. 20-23, 0014-0333

German

Literaturangaben

article

2020

Waldorfpädagogik ; Jugend ; Oberstufenunterricht ; Waldorfschule ; Symposium ; Oberstufenschüler ; Deutschland ; Kassel

Erziehungskunst, Bd. 84 (2020) H. Spezial 1, S. 31-33, 0014-0333

German

0305-0491

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Electronic Resource

1432-1440

Experimental acute pancreatitis ; Secretin-ceruletid stimulation ; Phospholipase A activity

Springer Online Journal Archives 1860-2000

Medicine

Summary As a result of pancreas stimulation with secretin-ceruletid we were able to measure the release of phospholipase A in ascites, serum, lymph, and urine in acute experimental pancreatitis in the dog. After induction of acute pancreatitis we found no increase over the normal range in serum, lymph, and urine phospholipase A activities. In addition, the stimulation of the exocrine pancreas did not show a significant change in phospholipase A activity. The excessively high phospholipase A activity in ascites following induction of acute pancreatitis fell significantly after pancreas stimulation with secretin-ceruletid.

Electronic Resource

1432-0533

Neuropeptides ; Amygdala ; Immunohistochemistry ; Schizophrenia ; Huntington's chorea

Springer Online Journal Archives 1860-2000

Medicine

Summary The location of the neuropeptides methionine-enkephalin (ME), neurotensin (NT), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) within the amygdaloid complex of healthy human individuals, schizophrenics and patients suffering from Huntington's chorea was studied qualitatively by means of immunohistochemistry. VIP-like immunoreactivity (IR) was present predominantly in a dense cluster of fibers and terminals in the central amygdaloid nucleus. ME-IR was observed in fibers, terminals and cell bodies in the same subnucleus, exhibiting a characteristical distribution pattern. NT-positive cell bodies were situated within the center of the central amygdaloid nucleus, fibers and terminals being encountered mainly at the periphery. NPY-IR was found to be evenly distributed throughout the amygdala. Distribution and staining intensity of ME, NPY and NT in the amygdala showed no qualitatively recognizable difference between the normal and schizophrenic specimens, whereas VIP-IR appeared to be slightly increased in the central amygdaloid nucleus of schizophrenics. In the choreic cases, the considerably shrunken amygdala exhibited only very low staining intensity of the four investigated neuropeptides.

Electronic Resource

1432-0533

Methionine-enkephalin ; Substance P ; Schizophrenia ; Huntington's disease ; Parkinson's disease

Springer Online Journal Archives 1860-2000

Medicine

Summary The distribution of methionine-enkephalin (ME)-like and substance P (SP)-like immunoreactivity in the basal ganglia of untreated schizophrenics as compared with normal control cases, and untreated Huntington and Parkinson patients was studied using the unlabeled peroxidase-antiperoxidase (PAP) method: ME but not SP was reduced in the pallidum of one of six schizophrenics. The remainig five cases showed no differences to the controls. In contrast, no or only very faint homogeneously distributed ME and SP was found in any part of the basal ganglia in Huntington's disease. In Parkinson's disease, SP immunoreactivity was within normal range.

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary An accessory for a commercial 10-place filtration apparatus is described, which allows the easy recovery of both filter-bound material and flow-through in the study of DNA-protein interactions by assaying binding of protein to cellulose nitrate filters.

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary A method is described which permits the measurement of DNA amounts of as low as 0.5 ng by photographing the fluorescence of ethidium bromide after complete removal of unbound dye. The DNA is immobilized in thin layers of agarose.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract A method is outlined for the measurement of NADH2-dependent dehydrogenase activity in whole samples as well as in fractions of carbonate sediments. The method is based on extraction of enzyme activity with phosphate buffer containing 0.12% Triton X-100, dialysis, and a photometric assay which permits initial velocity determinations of the enzyme reaction under controlled conditions of pH, temperature, and substrate concentration. The dehydrogenases extracted from carbonate sediment of a subtropical beach at Bermuda are characterized by low K m values (0.03 to 0.07 mM NADH2/1), pH maxima around 8.5, and temperature maxima between 35° and 40°C. Their vertical distribution in the sediment agrees with what is known about the distribution of biomass on beaches of this type, maximum activity occurring in the topmost centimetre. Approximately 80 to 90% of the total electron transport activity is contained in the grain fraction, the remainder in the interstitial fraction of a sediment sample. From this it can be inferred that the interstitial fauna contributes only little to the total energy budget of this type of sediment, which is dominated by the “Aufwuchs” on the sand grains. The electron transport activity (ETA) measured by means of the dehydrogenase assay is taken to represent the maximum transport capacity (ETC) of all the organisms living in the sand ecosystem. From published evidence it is inferred that oxygen consumption of sediment samples and of individual organisms measured in vivo usually accounts for 10 to 20% of the maximum electron transport capacity measured in vitro with saturating concentrations of substrates and with Triton X-100 as part of the enzyme assay. It is suggested further that the ratios of dehydrogenase activities in different fractions or zones of sediment, or of different organisms, may represent one of the best indicators, so far available, of energy relationships in marine sediments.

Electronic Resource

1434-3916

Springer Online Journal Archives 1860-2000

Medicine

Zusammenfassung 108 Sehnen des M. extensor hallucis longus wurden innerhalb von 36 h nach dem Tode mit einer Zugprüfmaschine bei einer Einspannlänge von 20 mm untersucht. Nach Einstellen eines „steady state“ durch cyclische Vorbelastungen wurden die Sehnen jeweils bis auf eine maximale Last von 18 kp gedehnt, dann bis auf bestimmte Kraftniveaus entlastet und die Dehnung konstantgehalten. Bei hoher Ausgangsbelastung fällt dann die Spannung innerhalb der Sehne ab (Relaxation), bei mittlerer und niedriger Ausgangsbelastung steigt die Spannung etwas an (Spannungsrückgewinn = mechanische Erholung). Zwischen Relaxations- und Spannungsrückgewinnbereich gibt es eine Belastung, bei der sich die Spannung nicht ändert (isorheologischer Punkt). Die Lage des isorheologischen Punktes ist abhängig von der Vordehnungsgeschwindigkeit. Bei langsamer Dehnung (2 mm/min) liegt der isorheologische Punkt bei etwa 70% der maximalen Ausgangsspannung, bei schneller Dehnung (12 mm/min) bei etwa 60%. Die maximale Relaxation wird bei maximaler Ausgangsspannung erzielt, der Spannungsrückgewinn ist jedoch nicht bei Entlastung auf Null am größten, sondern in einem Bereich von etwa 5 bis 25% der maximalen Ausgangsspannung. Die maximale Relaxation ist etwa 5- bis 6mal größer als der maximale Spannungsrückgewinn. Vermutlich laufen Relaxations-und Spannungsrückgewinnvorgänge gleichzeitig ab, aber mit verschiedener Intensität je nach Ausgangsspannung. Dabei besteht zumindest der Relaxationsvorgang aus mehreren Komponenten unterschiedlicher Geschwindigkeit. Damit dürfte das Phänomen der „Sekundärrelaxation“ zu erklären sein: Registriert man Spannungsrückgewinnkurven über genügend lange Zeit, so fällt die Spannung wieder etwas ab.

Summary 108 tendons of the m. extensor hallucis longus were examined with a tensile testing machine within 36 h after death. The specimen were kept at a resting length of 20 mm. After the “steady state” was reached by cyclic loading, the tendons were stretched up to a maximum load of 18 kp, then deloaded to a certain level and after that the elongation was kept constant. At high loading level the tension of the tendon decreases with time (relaxation). At medium and low loading level the tension increases slightly (mechanical recovery). Between that two regions there is a certain load, where the tension will not change with time (isorheological point). The position of the isorheological point depends on the velocity of the elongation. At low velocity (2 mm/min) the isorheological point is situated at 70%, at high velocity (12 mm/min) at 60% of the maximum load. One will find the maximum relaxation, when no deloading occurs. The mechanical recovery, however, has its maximum at 5–25% of the maximum load. But when the tendon is totally deloaded, there seems to occur no recovery. The maximum relaxation is 5 to 6 times larger than the maximum recovery. Supposingly the relaxation- and recovery-processes will happen at the same time but with different intensity depending on the loading level. At least the relaxation-process consists of different relaxation components with different relaxation times. This will explain the phenomenon of a “secondary relaxation”: After a long time of registration the recovery will turn into a slight relaxation.

Electronic Resource

0933-5137

Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Biomechanics and Simulation of the Tensile Behaviour of the Chordae tendineae of the Human Heart: Many problems in the field of medical research and clinical practise can be solved only by a more detailed knowledge of the material properties of biological tissues. Among other things it is the task of the biomedical engineer to support the physician in his research work to develop a material suitable for prothesises and artificial organs by application of the modern methods of the materials testing as well as his knowledge of the materials mechanics. These efforts are preceded by basic investigations of the tissue of that organ or of that part of the body which has to be replaced. For only then the important demands are fulfilled optimally, i. e. compatibility and an accurate function in a mechanical and a rheological sense. In a previous paper we investigated the strength and the rheological properties of the Chordae tendineae of the human heart with an electronic tensile testing machine. The present investigations shall show that these biomechanical phenomena can be reproduced by a nonlinear viscoelastic material model and can be simulated with an analogue computer.

Viele Probleme in der medizinischen Forschung und Klinik lassen sich nur mit einer detaillierten Kenntnis des Stoffverhaltens biologischer Gewebe lösen. Es ist u. a. die Aufgabe des in der Biomedizinischen Technik tätigen Ingenieurs, dem Mediziner dei seiner Suche nach geeigneten Materialien für Prothesen und Implantate durch Anwendung moderner Methoden des Materialprüfungswesens sowie der Kenntnis der Werkstoffmechanik zu helfen. Diesen Bemühungen müssen Untersuchungen prinzipieller Art am Gewebe des zu ersetzenden Organ-bzw. Körperteils vorangehen, weil nur dann die wichtigen Forderungen, nämlich Kompatibilität und richtige Funktion in mechanischer und rheologischer Hinsicht, optimal erfüllt werden können. In einer früheren Studie haben wir das Festigkeitsverhalten und die rheologischen Eigenschaften der Sehnenfäden (Chordae tendineae) des menschlichen Herzens, die wichtige biomechanische Funktionen übernehmen, mit einer elektronischen Zugprüfmaschine getestet. Die vorliegenden Untersuchungen sollen zeigen, daß sich diese biomechanischen Phänomene mit einem nichtlinear viskoelastischen Werkstoffmodell reproduzieren lassen und mit Hilfe eines Analogrechners simuliert werden können.

17 Ill.

Electronic Resource