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Curt Herbst 《Development genes and evolution》1937,136(1):147-168
Ohne Zusammenfassung 相似文献
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Zusammenfassung Die Praxis der Schädlingsbekämpfung wird auf die Möglichkeit hingewiesen, durch stärkere Berücksichtigung protoplasmatischer Gedankengänge und Methoden der Lösung ihrer Probleme näher zu kommen.Auf der anderen Seite eröffnen sich der Protoplasmaforschung durch Berücksichtigung der auftauchenden Fragestellungen neue Wege der Erkenntnis.An einigen praktischen Beispielen wird die Arbeitsmöglichkeit auf diesem Gebiete gezeigt. DasHelodea- Blatt erwies sich als ein ausgezeichnetes Versuchsobjekt zum Studium der Wirkung einzelner Gifte und, innerhalb gewisser Grenzen, als ein gutes Testobjekt zum Vergleich verschiedener oder verschieden angewandter Schädlingsbekämpfungsmittel.Es wird die Abtötungskurve desHelodea-Blattes für Nikotin aufgestellt.Nikotin kann in charakteristischer Weise auf die Wanderung der Piastiden Einfluß haben (Brückenstellung der Plastiden).Eine ähnliche Kurve wird für Schwefelkalk gegeben. Unter gewissen Bedingungen geht mit der Zellvergiftung eine Schwärzung des gesamten Plasmaapparates, vor allem zuerst der Plastiden, einher.Für die Vergiftung mit Kupferkalk gelten besondere Voraussetzungen, auch hier dürfte sich dasHelodea-Blatt als Versuchsobjekt bewähren. 相似文献
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Rognoni Franco Gianesello Daniela Maddalena Fabrizio Giuntini Ilaria Herbst Detlev 《Cytotechnology》1999,29(1):11-25
Anti PSA monoclonal antibodies for diagnostic use were produced in an in vitro system. After purification using Protein G affinity chromatography a percentage of about 10% of antibody aggregates remained. The use of monoclonal antibodies containing aggregates as a capture antibody in a diagnostic kit reduces the performance of the test making it often unacceptable. The aggregates could be eliminated using gel filtration chromatography but, in that way, the final recovery of the whole production process was only about 50%. Aggregation is favoured when the working pH is near to the isoelectric point of the antibody. We varied the culture medium composition, modifying pH and osmolarity. We tested different values of pH and osmolarity: 7.1, 7.5, 8.0, 8.5 for pH, and 300, 340, 367, 395 mOsm/kg H2O for osmolarity. By modification of the cell culture medium we obtained a significant decrease of monoclonal antibody aggregates in the production cycle. In this way we achieved higher recovery rate and could avoid gel filtration polishing step. The experiments were performed in two stages: first in culture flasks changing one parameter in each experiment, and then in spinner bottle using the best conditions obtained in the first stage. During scale up we used the modifications achieved from the experiment showed in this paper in our production by hollow fibre bioreactor with positive results. 相似文献
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Christopher Boehlke Heike Janusch Christoph Hamann Christian Powelske Miriam Mergen Henriette Herbst Fruzsina Kotsis Roland Nitschke E. Wolfgang Kuehn 《PloS one》2015,10(10)
Ift88 is a central component of the intraflagellar transport (Ift) complex B, essential for the building of cilia and flagella from single cell organisms to mammals. Loss of Ift88 results in the absence of cilia and causes left-right asymmetry defects, disordered Hedgehog signaling, and polycystic kidney disease, all of which are explained by aberrant ciliary function. In addition, a number of extraciliary functions of Ift88 have been described that affect the cell-cycle, mitosis, and targeting of the T-cell receptor to the immunological synapse. Similarly, another essential ciliary molecule, the kinesin-2 subunit Kif3a, which transports Ift-B in the cilium, affects microtubule (MT) dynamics at the leading edge of migrating cells independently of cilia. We now show that loss of Ift88 impairs cell migration irrespective of cilia. Ift88 is required for the polarization of migrating MDCK cells, and Ift88 depleted cells have fewer MTs at the leading edge. Neither MT dynamics nor MT nucleation are dependent on Ift88. Our findings dissociate the function of Ift88 from Kif3a outside the cilium and suggest a novel extraciliary function for Ift88. Future studies need to address what unifying mechanism underlies the different extraciliary functions of Ift88. 相似文献
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Josephine Herbst Annabel Girke Mohammad Reza Hajirezaei Guy Hanke Bernhard Grimm 《The Plant journal : for cell and molecular biology》2018,94(3):485-496
Chlorophyll is synthesized from activated glutamate in the tetrapyrrole biosynthesis pathway through at least 20 different enzymatic reactions. Among these, the MgProto monomethylester (MgProtoME) cyclase catalyzes the formation of a fifth isocyclic ring to tetrapyrroles to form protochlorophyllide. The enzyme consists of two proteins. The CHL27 protein is proposed to be the catalytic component, while LCAA/YCF54 likely acts as a scaffolding factor. In comparison to other reactions of chlorophyll biosynthesis, this enzymatic step lacks clear elucidation and it is hardly understood, how electrons are delivered for the NADPH‐dependent cyclization reaction. The present study intends to elucidate more precisely the role of LCAA/YCF54. Transgenic Arabidopsis lines with inactivated and overexpressed YCF54 reveal the mutual stability of YCF54 and CHL27. Among the YCF54‐interacting proteins, the plastidal ferredoxin‐NADPH reductase (FNR) was identified. We showed in N. tabacum and A. thaliana that a deficit of FNR1 or YCF54 caused MgProtoME accumulation, the substrate of the cyclase, and destabilization of the cyclase subunits. It is proposed that FNR serves as a potential donor for electrons required in the cyclase reaction and connects chlorophyll synthesis with photosynthetic activity. 相似文献