共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
3.
4.
5.
6.
7.
Dr. K. Felgenhauer 《Histochemistry and cell biology》1964,4(3):181-196
Zusammenfassung Mit einer 5×10–3molaren stabilen Emulsion von -Naphthylacetat läßt sich die unspezifische Esterase in jeder Nervenzelle des Meerschweinchengehirns nachweisen. Sie ist mit Ausnahme weniger Kerngebiete vorwiegend im Perikaryon lokalisiert, die Zellfortsätze sind wesentlich geringer aktiv. Das differente Verhalten gegen verschiedene Inhibitoren und die völlig unterschiedlichen Verteilungsmuster beweisen, daß sich mit den angewandten histochemischen Methoden die unspezifische Esterase und die Acetylcholinesterase ohne wesentliche Überlagerung nebeneinander nachweisen lassen. Die Verteilungsunterschiede werden beschrieben. Der größte Teil der Esterase wird durch E 600 gehemmt und gehört deshalb zum Typ B.Nach vergleichender Untersuchung einer Reihe histochemisch nachweisbarer Enzyme wird ein Modell der Enzymverteilung im Zentralnervensystem zur Diskussion gestellt. In vielen dendritenreichen telencephalen Kerngebieten gibt es deutliche Aktivitätsunterschiede zwischen dem Perikaryon und den Zellfortsätzen. Während der größte Teil der am Energiestoffwechsel beteiligten Enzyme in der Masse der Zellfortsätze lokalisiert ist, sind die beiden Hydrolasen unspezifische Esterase und saure Phosphatase im Perikaryon konzentriert.
Frau E. Reuter bin ich für ihre technische Hilfe zu großem Dank verpflichtet. 相似文献
8.
9.
10.
11.
12.
Karl Trincher 《Biological cybernetics》1980,39(1):1-10
The nucleo-free erythrocyte is presented as the simplest differentiated cell whose energy-exchange has the single purpose of preserving the cell structure; this structure is based on the regular quasi-crystalline state of intracellular water, which is expressed by the negative entropy(-S
W
)and the temperature T
W
which is higher than the temperature of the extracellular water T. The information content of intracellular water, J
W
is proportional to the temperature difference: J
W
T=T
W
-T. The regular state of intracellular water is maintained by the basal metabolism that takes place in the membrane of the differentiated cell. The energy exchange, i.e., the absorption of free energy and the liberation of an equivalent amount of heat, occurs in the form of work cycles of the enzym-water-complexes in the cell membrane. The differentiated cell of the multicellular animal organism is the result of embryogenetic processes accompanied by heat-liberation. The specific heat-liberation, i.e., the heat produced by a single cell, begins with a quasi-zero value of the fertilized egg cell and grows with acceleration to a maximum value at the end of embryogenesis. This process of acceleration of heat-liberation is caused by the entrance of the water from the outer medium into the embryonic cell; the water undergoes the phasechange fluid crystal with heat-liberation. The intracellular water within the embryonic cell becomes structurated; this is also accompanied by growing heatliberation. The thermodynamic characteristic of embryo genetic development is expressed by the principle of the maximum of velocity of entropy production of the cell at the end state of the process of differentiation. This principle applied to phylogenetics, leads to the formulation of the principle of accumulation of biological information: J(t). In the course of evolution living systems are able not only to store information of past generations, but also to create information: J(t)eIntl where t is the time of phylogenesis. 相似文献
13.
Rainer Willmann 《Pal?ontologische Zeitschrift》1981,55(1-2):31-49
The colonisation history of the Eomeropidae (syn.: Notiothaumidae) is discussed based on the phylogenetic relationships among the five known genera of this family and their geographic distribution. Between the Recent South-AmericanNotiothauma andEomerope from the Tertiary of North America and eastern Asia exists a sister-group relationship. Together with the more plesiomorphous generaBlattomerope andPronotiothauma from the Triassic of Kirghizia they form a monophyletic group of higher rank, but it is not clear whetherBlattomerope, Pronotiothauma orBlattomerope + Pronotiothauma are the sister-group ofEomerope + Notiothauma. The most primitive genus of the Eomeropidae isThaumatomerope, also from the Triassic of Kirghizia. According to these relationships the Eomeropidae are supposed to have evolved in the northern hemisphere. From hereNotiothauma as one of the most highly evolved genera or its direct ancestor migrated to the south, probably in Mesozoic times. It seems less probable that the Eomeropidae were a cosmopolitan group and that incidentally the plesiomorphous sister-groups of bothNotiothauma andEomerope + Notiothauma as well as the most plesiomorphous genus of this family, are known from the northern hemisphere only. Penny’s assumption thatNotiothauma must have had its origin among Mecoptera with few costal cross-veins is rejected. The Eomeropidae and the Meropeidae arose directly from ancestors with numerous costal cross-veins. In spite of this the two families evidently do not form a monophyletic group (e.g. “Protomecoptera”) as the similarities between them are due to symplesiomorphies, as previous authors have pointed out. A synapomorphous character shared by Eomeropidae and Meropeidae is not known. The method of deducing the colonisation history of a taxon from the geographic distribution of its closest allies is briefly discussed. 相似文献
14.
Ohne Zusammenfassung
Für geldliche F?rderung der Versuche wird der Deutschen Gesellschaft für Holzforschung gedankt. 相似文献
15.
16.
17.
Ohne ZusammenfassungMit 5 Textabbildungen 相似文献
18.
19.
20.
Elisabeth Tschermak-Woess 《Plant Systematics and Evolution》1970,118(1-2):72-77
Zusammenfassung Das zweiteilige Pyrenoid der ChrysocapsaleChrysochaete britannica tritt im Leben deutlich, mangelhaft oder gar nicht hervor, was offenbar auf Veränderungen in den Lichtbrechungsverhältnissen der Zellkomponenten beruht, die außer von unbekannten Faktoren auch von der Temperatur beeinflußt werden. Nach Fixierung oder Färbung läßt es sich regelmäßig nachweisen.In den Zoosporen liegt der an sich länglich plattenförmige, an den Rändern umgeschlagene Chromatophor und damit das Pyrenoid seitlich; der tiefere hintere und der seichtere vordere Einschnitt des Chromatophors verläuft parallel zur Längsachse der Zelle. Das Stigma befindet sich in der Regel im Isthmus, am Rand des vorderen Einschnitts.
Summary The pyrenoid ofChrysochaete britannica is conspicuous or badly or even not at all visible in the living state. It can be demonstrated regularly after fixing or staining.In the zoospores the chromatophore is situated at the side. It has the form of a band with inturned edges and with an anterior shallow and a posterior deep incision. The stigma as a rule is located within the isthmus at the edge of the anterior incision.相似文献