Search results for "structural organization"
showing 10 items of 16 documents
Communication: anion-specific response of mesoscopic organization in ionic liquids upon pressurization
2018
One of the outstanding features of ionic liquids is their inherently hierarchical structural organization at mesoscopic spatial scales. Recently experimental and computational studies showed the fading of this feature when pressurising. Here we use simulations to show that this effect is not general: appropriate anion choice leads to an obstinate resistance against pressurization. Published by AIP Publishing.
Mesoscopic structural organization in fluorinated pyrrolidinium-based room temperature ionic liquids
2019
Abstract In this contribution the microscopic and mesoscopic structural organization in a series of fluorinated room temperature ionic liquids, based on N-methyl-N-alkylpyrrolidinium cations and on bis(perfluoroalkylsulfonyl)imide anions, is investigated, using a synergy of experimental (X-ray and neutron scattering) and computational (Molecular Dynamics) techniques. The proposed ionic liquids are of high interest as electrolyte media for lithium battery applications. Together with information on their good ion transport properties in conjunction with low viscosity, we also describe the existence of nm-scale spatial organization induced by the segregation of fluorous moieties into domains. …
Antigen recognition by T cells: a strong sense of structure
2001
Dynamic architecture and regulatory implications of the miRNA network underlying the response to stress in melon
2019
miRNAs are small RNAs that regulate mRNAs at both transcriptional and posttranscriptional level. In plants, miRNAs are involved in the regulation of different processes including development and stress-response. Elucidating how stress-responsive miRNAs are regulated is key to understand the global response to stress but also to develop efficient biotechnological tools that could help to cope with stress. Here, we describe a computational approach based on sRNA sequencing, transcript quantification and degradome data to analyse the accumulation, function and structural organization of melon miRNAs reactivated under seven biotic and abiotic stress conditions at two and four days post-treatmen…
Binding of concanavalin A to the surface of unfertilized and fertilized ascidian eggs.
1973
STUDIES with certain carbohydrate-binding proteins of plant origin (as concanavalin A and wheat germ agglutinin) have indicated that some surface properties of embryonic1,2 and of virally transformed cells3–6 are different from those of adult cells. The interpretation of the differences in terms of structural organization of the cell surface is, however, still controversial (see for example refs. 7 and 8).
Mesoscopic structural organization in triphilic room temperature ionic liquids
2013
Room temperature ionic liquids are one of the most exciting classes of materials in the last decade. The interest for these low melting, ionic compounds stems from both their technological impact and the stimulating plethora of structural and dynamic peculiarities in the mesoscopic space-time scales. It is nowadays well-established that they are characterised by an enhanced degree of mesoscopic order originating from their inherent amphiphilicity. In this contribution we highlight the existence of a further degree of mesoscopic complexity when dealing with RTILs bearing a medium length fluorous tail: such triphilic materials (they simultaneously contain polar, hydrophobic and fluorophilic m…
Pressure-responsive mesoscopic structures in room temperature ionic liquids
2015
Among the most spectacular peculiarities of room temperature ionic liquids, their mesoscopically segregated structural organization keeps on attracting attention, due to its major consequences for the bulk macroscopic properties. Herein we use molecular dynamics simulations to explore the nm-scale architecture in 1-octyl-3-methylimidazolium tetrafluoroborate, as a function of pressure. This study reveals an intriguing new feature: the mesoscopic segregation in ionic liquids is characterized by a high level of pressure-responsiveness, which progressively vanishes upon application of high enough pressure. These results are in agreement with recent X-ray scattering data and are interpreted in …
Structural Organization of Poly(vinyl alcohol) Hydrogels Obtained by Freezing and Thawing Techniques: A SANS Study
2005
The structural organization of matter in poly(vinyl alcohol) (PVA) hydrogels obtained by repeatedly freezing and thawing dilute solutions of PVA in D2O is investigated by use of small-angle neutron scattering measurements (SANS). This study is the first systematic and quantitative investigation in the medium range of length scales on PVA hydrogels obtained by freezing and thawing techniques. The studied gels have a complex hierarchical structure, extending over a wide range of length scales. The structural organization on the micron length scale originates from the presence of two separated phases constituted by polymer-rich and polymer-poor regions. The network structure may be interpreted…
What Makes a Text Easy or Difficult to Understand?
1989
Abstract The question of what makes a text easy or difficult to comprehend is answered on the basis of an empirical investigation, which draws especially on theories related to text and memory linguistics. Easy and difficult texts, verified empirically, were analyzed on micro‐ and macro‐levels. Certain aspects of syntax, lexicon and information structure were first studied. These were followed by text‐level analyses related to the narrative and structural organization and the propositional structure of the texts. The article gives an account of the parameters that were most clearly associated with level of text comprehension. The results are also discussed in the light of the possible impli…