Refine
Year of publication
- 2014 (1077) (remove)
Document Type
- Article (1077) (remove)
Language
Has Fulltext
- yes (1077)
Keywords
- Benjamin, Walter (18)
- Deutsch (15)
- Literatur (14)
- red riječi (13)
- Mehrsprachigkeit (12)
- word order (12)
- Bratoljub Klaić (10)
- Rezeption (10)
- Begriff (9)
- Croatian language (8)
Institute
- Medizin (233)
- Biowissenschaften (77)
- Präsidium (62)
- Physik (56)
- Geowissenschaften (34)
- Biochemie und Chemie (32)
- Gesellschaftswissenschaften (29)
- Biodiversität und Klima Forschungszentrum (BiK-F) (28)
- Senckenbergische Naturforschende Gesellschaft (26)
- Frankfurt Institute for Advanced Studies (FIAS) (20)
Cryo-electron tomography provides a snapshot of the cellular proteome. With template matching, the spatial positions of various macromolecular complexes within their native cellular context can be detected. However, the growing awareness of the reference bias introduced by the cross-correlation based approaches, and more importantly the lack of a reliable confidence measurement in the selection of these macromolecular complexes, has restricted the use of these applications. Here we propose a heuristic, in which the reference bias is measured in real space in an analogous way to the R-free value in X-ray crystallography. We measure the reference bias within the mask used to outline the area of the template, and do not modify the template itself. The heuristic works by splitting the mask into a working and a testing area in a volume ratio of 9:1. While the working area is used during the calculation of the cross-correlation function, the information from both areas is explored to calculate the M-free score. We show using artificial data, that the M-free score gives a reliable measure for the reference bias. The heuristic can be applied in template matching and in sub-tomogram averaging. We further test the applicability of the heuristic in tomograms of purified macromolecules, and tomograms of whole Mycoplasma cells.
Correlative microscopy incorporates the specificity of fluorescent protein labeling into high-resolution electron micrographs. Several approaches exist for correlative microscopy, most of which have used the green fluorescent protein (GFP) as the label for light microscopy. Here we use chemical tagging and synthetic fluorophores instead, in order to achieve protein-specific labeling, and to perform multicolor imaging. We show that synthetic fluorophores preserve their post-embedding fluorescence in the presence of uranyl acetate. Post-embedding fluorescence is of such quality that the specimen can be prepared with identical protocols for scanning electron microscopy (SEM) and transmission electron microscopy (TEM); this is particularly valuable when singular or otherwise difficult samples are examined. We show that synthetic fluorophores give bright, well-resolved signals in super-resolution light microscopy, enabling us to superimpose light microscopic images with a precision of up to 25 nm in the x-y plane on electron micrographs. To exemplify the preservation quality of our new method we visualize the molecular arrangement of cadherins in adherens junctions of mouse epithelial cells.
Bacteria have adapted their NhaA Na(+)/H(+) exchangers responsible for salt homeostasis to their different habitats. We present an electrophysiological and kinetic analysis of NhaA from Helicobacter pylori and compare it to the previously investigated exchangers from Escherichia coli and Salmonella typhimurium. Properties of all three transporters are described by a simple model using a single binding site for H(+) and Na(+). We show that H.pylori NhaA only has a small acidic shift of its pH-dependent activity profile compared to the other transporters and discuss why a more drastic change in its pH activity profile is not physiologically required.
Survivin is a well-established target in experimental cancer therapy. The molecule is over-expressed in most human tumors, but hardly detectable in normal tissues. Multiple functions in different subcellular compartments have been assigned. It participates in the control of cell division, apoptosis, the cellular stress response, and also in the regulation of cell migration and metastasis. Survivin expression has been recognized as a biomarker: high expression indicates an unfavorable prognosis and resistance to chemotherapeutic agents and radiation treatment. Survivin is an unconventional drug target and several indirect approaches have been exploited to affect its function and the phenotype of survivin-expressing cells. Interference with the expression of the survivin gene, the utilization of its messenger RNA, the intracellular localization, the interaction with binding partners, the stability of the survivin protein, and the induction of survivin-specific immune responses have been taken into consideration. A direct strategy to inhibit survivin has been based on the identification of a specifically interacting peptide. This peptide can recognize survivin intracellularly and cause the degradation of the ligand–survivin complex. Technology is being developed that might allow the derivation of small molecular-weight, drug-like compounds that are functionally equivalent to the peptide ligand.
Die Naturwissenschaften waren von den teilweise gewalttätigen Auseinandersetzungen der Studentenproteste Ende der 1960er Jahre nicht an erster Stelle betroffen. Insbesondere das Pharmaziestudium mit seinem zeitintensiven, streng geregelten und durch Laborpraktika dominierten Arbeitsalltag bot wenig Raum für politische Agitationen. Andererseits waren die Studierenden auch nicht mit den Herausforderungen einer sich entwickelnden Massenuniversität konfrontiert. Nichtsdestoweniger mussten sich auch die Hochschullehrer der naturwissenschaftlichen Fakultät mit den zeitgenössischen Reformvorschlägen auseinandersetzen. Der pharmazeutische Chemiker Herbert Oelschläger, eine der prägenden Persönlichkeiten der Frankfurter Pharmazie, scheute diese Auseinandersetzungen nicht und wurde deshalb zu einer beliebten Zielscheibe des AStA.
Der "diskus" war in den 1970er Jahren mehr als eine Studentenzeitung. Die Blattmacher boten der linken Sponti-Szene in Frankfurt, aber auch Schriftstellern wie Erich Fried dort ein publizistisches Forum. Das Themenspektrum reichte von dem Häuserkampf im Westend bis zur Situation der linken Intellektuellen in der Bundesrepublik, nachdem sich das innenpolitische Klima infolge der RAF-Anschläge verschärft hatte.
War "68" nur der mythologische Name für Ereignisse und Entwicklungen, die schon viel früher begannen und sich deutlich länger hinzogen? Fühlte sich die immobil gewordene Gesellschaft in der Phase nach dem Wiederaufbau durch die Studentenrevolte von sich selbst befreit? Was hat die "Bewegungsgesellschaft" ab den 1970er Jahren mit "68" zu tun? Diesen Fragen geht der Soziologe Heinz Bude in seinem Essay nach.
Philologe im "Kriegseinsatz" : der Frankfurter Germanist Julius Petersen und der Erste Weltkrieg
(2014)
Vorlesungen für Studenten und Bildungsangebote für Bürger – wie lässt sich dieser Anspruch der jungen Stiftungsuniversität auch in Zeiten des Krieges realisieren, wenn Professoren wie Studenten ins Feld ziehen müssen? Das Beispiel des Germanisten Julius Petersen zeigt, welche Anstrengungen zwischen 1914 und 1918 unternommen wurden, um "Volksbildung" und "Vaterländischen Unterricht" zu ermöglichen. Dazu gehörten Vorträge an der Front ebenso wie Bürgervorlesungen in der Heimat.