Search results for " wall"
showing 10 items of 692 documents
Archaeal Cell Walls
2001
Archaea represent the third domain of life with the Bacteria and Eukarya. They have developed different types of cell envelopes. Keywords: glutaminylglycan; heteropolysaccharide; methanochondroitin; pseudomurein; S-layer (glyco-)protein; Archaea; cell envelope
Microtubules and cell shaping in the mesophyll ofNigella damascena L.
1993
Cell shaping in the mesophyll ofNigella damascena was investigated with the aim of determining the origin of the arm-like protrusions, which are characteristic of, e.g., arm-palisade cells. It was found that hoops of cell wall were deposited during the early stages of cell expansion. The hoops were interconnected, thus embracing the cells with a wide-meshed net of local wall reinforcement. The pattern of wall deposition in the extra-cellular matrix correlated with a pattern of bands of microtubules in the cortical cytoplasm of the cells. During lateral expansion bulges were forced through the comparatively thin walls of spaces between the meshes, giving rise to the arm-like protrusions. Aft…
Cell shaping and microtubules in developing mesophyll of wheat (Triticum aestivum L.)
1990
Differentiated mesophyll cells ofTriticum aestivum (cv. Star) exhibit a lobed outline resembling tube-shaped balloons with almost regularly spaced constrictions. It was shown that these constrictions are probably the result of hoops of wall reinforcements laid down during early stages of cell expansion. It appears that these hoops prevent expansion in the corresponding regions and thus give rise to the peculiar cell shape. The comparatively thin cell walls of the bulges are uniformly reinforced after the lobed shape is established. By using immunofluorescence techniques a change in the pattern of cortical microtubule arrangement was observed which corresponded to the pattern of cell wall de…
Overview of the JET results
2015
Since the installation of an ITER-like wall, the JET programme has focused on the consolidation of ITER design choices and the preparation for ITER operation, with a specific emphasis given to the bulk tungsten melt experiment, which has been crucial for the final decision on the material choice for the day-one tungsten divertor in ITER. Integrated scenarios have been progressed with the re-establishment of long-pulse, high-confinement H-modes by optimizing the magnetic configuration and the use of ICRH to avoid tungsten impurity accumulation. Stationary discharges with detached divertor conditions and small edge localized modes have been demonstrated by nitrogen seeding. The differences in…
Computational Study on Cesium Azide Trapped in a Cyclopeptidic Tubular Structure
2008
The structures and the electronic properties of host-guest complexes formed by a cyclopeptidic tubular aggregate and the species CsN3, CS2(N-3)(2), and CS2N6 have been investigated by means of density functional theory. Taking advantage of the azide property to act as a bridge ligand between two or more metal cations, it may be possible to trap N-3(-) ions inside a confined space. This could be important for the preparation of polynitrogen molecules N-n. Results show that there are significant attractive interactions between the azide ion and the cavity walls, which make the ion stay inside the inner empty space of the cyclopeptidic aggregate. The confinement of the species CS2(N-3)(2) forc…
Comparison of the greenhouse gas emissions of a high-rise residential building assessed with different national LCA approaches– IEA EBC Annex 72
2020
Introduction: The international research project IEA EBC Annex 72 investigates the life cycle related environmental impacts caused by buildings. The project aims inter alia to harmonise LCA approaches on buildings. Methods: To identify major commonalities and discrepancies among national LCA approaches, reference buildings were defined to present and compare the national approaches. A residential high-rise building located in Tianjin, China, was selected as one of the reference buildings. The main construction elements are reinforced concrete shear walls, beams and floor slabs. The building has an energy reference area of 4566 m2 and an operational heating energy demand of 250 MJ/m2a. An ex…
Modulation of the growth and metabolic response of cyanobacteria by the multifaceted activity of naringenin
2017
The interactions between the plant-derived bioflavonoid, naringenin, and prokaryotic microalgae representatives (cyanobacteria), were investigated with respect to its influence on the growth and metabolic response of these microorganisms. To achieve reliable results, the growth of cyanobacteria was determined based on measurements of chlorophyll content, morphological changes were assessed through microscopic observations, and the chemical response of cells was determined using liquid and gas chromatography (HPLC; GC-FID). The results show that micromolar levels of naringenin stimulated the growth of cyanobacteria. Increased growth was observed for halophilic strains at naringenin concentra…
Isolation and partial characterization of uronic acid-containing glycoproteins from Mucor rouxii.
1995
Five different fractions containing uronic acids associated with protein were isolated from the cytoplasm of the filamentous form of Mucor rouxii. A signle fraction was isolated from the cell wall by hot sodium dodecyl sulfate followed by ion exchange column chromatography. Two cytoplasmic entities (peaks I and II) were not adsorbed to DEAE Bio-Gel A. The molecular mass of peaks I to V ranged from 16.5 to 210 kDa. The protein-uronic acid ratios were different for each fraction. The cell wall fraction showed a molecular mass of 16.5 kDa, similar to that of peak II but with differences in chromatographic behavior and protein-uronic acid ratio. The possible role of these molecules as acceptors…
Protoplasts fromPodospora anserina: Isolation, purification, and transformation
1985
Protoplasts fromPodospora anserina mycelium were produced using the commercially available enzyme Novozym 234. Different parameters involved in protoplast isolation were analyzed in order to establish optimal conditions, and protoplast production was notably increased. For the purification of protoplasts, several techniques based on both centrifugation and filtration were assayed, with filtration yielding the best results. Regeneration of protoplasts was studied on different media and osmostic stabilizers, and about 80% regeneration was obtained. The good physiological condition of the protoplasts produced with this method is demonstrated by the lack of cell wall and high regeneration rate …
Therapeutic Angiogenesis in Surgery and Oncology
1994
The aim of this presentation is to demonstrate the pathological importance of microenvironmental tissue hypoxia and to elucidate a general treatment concept for this situation which we have termed therapeutic angiogenesis 1. Hypoxia not only represents an insufficient oxygen supply for the cells of a given tissue area but is also regarded as an indicator for their metabolic deprivation and the concomitant accumulation of waste products. Therapeutic angiogenesis applied either with clinically established methods or using novel ways, which are the objectives of laboratory research and clinical trials at present, or in so far hypothetical forms, should lead to an expansion of the functional mi…