742 research outputs found
Studio dell'idratazione di proteine in miscele acquose: esperimenti di small angle scattering
No full textExplanation of the stability of thermophilic proteins based on unique micromorphology
No full textTwo mesophilic/thermophilic variants of the G-domain of the elongation factor Tu were studied via molecular dynamics simulations. By analyzing the simulation data via the Voronoi space tessellation, we have found that the two proteins have the same macromolecular packing, while the water-exposed surface area is larger for the thermophile. A larger coordination with water is probably due to a peculiar corrugation of the exposed surface of this species. From an enthalpic point of view, the thermophile shows a larger number of intramolecular hydrogen bonds, stronger electrostatic interactions, and a flatter free-energy landscape. Overall, the data suggest that the specific hydration state enhances macromolecular fluctuations but, at the same time, increases thermal stability
NMR DETECTION AT 8.9 mT WITH A GMR BASED SENSOR COUPLED TO A SUPERCONDUCTING Nb FLUX TRANSFORMER
No full textInternational audience—This study presents NMR signal detection by means of a superconducting channel consisting of a Nb surface detection coil inductively coupled to a YBCO mixed sensor. The NMR system operates at a low-field (8.9 mT) in a magnetically shielded room suitable for magnetoencephalographic (MEG) recordings. The main field is generated by a compact solenoid and the geometry of the pickup coil has been optimized to provide high spatial sensitivity * Corresponding author: Raffaele Sinibaldi ([email protected]). 390 Sinibaldi et al. in the NMR field of view. The Nb detection coil is coupled to the mixed sensor through a Nb input coil. The mixed sensor consists of a superconducting YBCO loop with 2-µm constriction above which two Giant MagnetoResistance sensors are placed in a half-bridge configuration to detect changes of the bridge voltage as a function of the flux through the YBCO loop. The sensitivity of the receiving channel is calibrated experimentally. The measured spatial sensitivity is in agreement with the simulations and is ∼10 times better than that of the stand-alone mixed sensor. A NMR echo at 375 kHz shows a SNR only a factor 4 smaller than a tuned room temperature coil tightly wound around the sample, with a noise level which is a factor 3 better than for the volume coil. Our results suggest that mixed sensors are suitable for the integration of low-field MRI and MEG in a hybrid apparatus, where MEG and MRI would be recorded by SQUIDs and mixed sensors, respectively
Hydrophilicity of lysozyme in water–glycerol mixtures
No full textWe performed small angle neutron scattering experiments on lysozyme solvated in glycerol at different water contents to characterize the protein-solvent interface
A new software for dimensional measurements in 3D endodontic root canal instrumentation
No full textThe main issue to be faced to get size estimates of 3D modification of the dental canal
after endodontic treatment is the co-registration of the image stacks obtained through micro
computed tomography (micro-CT) scans before and after treatment. Here quantitative analysis of
micro-CT images have been performed by means of new dedicated software targeted to the analysis
of root canal after endodontic instrumentation. This software analytically calculates the best superposition
between the pre and post structures using the inertia tensor of the tooth. This strategy avoid
minimization procedures, which can be user dependent, and time consuming. Once the co-registration
have been achieved dimensional measurements have then been performed by contemporary
evaluation of quantitative parameters over the two superimposed stacks of micro-CT images. The
software automatically calculated the changes of volume, surface and symmetry axes in 3D occurring
after the instrumentation. The calculation is based on direct comparison of the canal and canal
branches selected by the user on the pre treatment image stack
Corrado Cagli. Transatlantic bridges, 1938-1947
No full textIn the 1930s the young Italian artist, Corrado Cagli was a rising star of the Scuola Romana, supported by the Fascist regime despite being both Jewish and a homosexual. Following the Racial Laws, he fled first to Paris, and then to the USA, where he remained until 1947. Raffaele Bedarida’s new book, Corrado Cagli – La pittura, l’esilio, l’America (1938-1947) Donzelli Editore, 2018 (soon to be translated into English by CPL Editions), focuses on Cagli’s American exile.
While examining Cagli in the context of the artistic and intellectual migration from Europe to the US, Bedarida provides valuable new insight into the specific plight of this Italian Jewish artist, once championed by Fascism and into the complexities of the use of art for cultural diplomacy.
The author combines biography, cultural history, and critical analysis in exploring a decisive period in the life and work of a painter whose complex personality and non-signature style, defy classifications. The book also provides thought-provoking and nuanced arguments on the ideologically based ostracism that Cagli encountered upon returning to Italy in the immediate aftermath of the war. Because of his past as a former regime-endorsed artist, his recent American success, his participation in the liberation of Europe from Nazi-Fascism with the American army, and Jewish exile, Cagli simply did not fit into any of the faction of Italy’s post-war heated cultural disputes.
Based on extensive original research and written with brio, Bedarida’s book is an essential contribution to a growing field of studies that examine how, by welcoming artist and intellectuals in flight from Nazi-Fascism, the United States had been given what Will Norman has called “custodianship for a civilization.
The Role of Water Coordination in Binary Mixtures. A Study of Two Model Amphiphilic Molecules in Aqueous Solutions by Molecular Dynamics and NMR
No full textTwo binary aqueous mixtures which contain the small amphiphilic molecules TMAO (trimethylamine-Noxide)
and TBA (tert-butyl alcohol) have been investigated by molecular dynamics simulations and NMR
chemical shift and self-diffusion measurements. TMAO is an osmolyte, while TBA is a monohydrate alcohol.
Both possess bulky hydrophobic groups and polar heads, namely, NO in TMAO and OH in TBA. The
hydrophilic/hydrophobic content of these isosteric molecules strongly modulates the structure and dynamics
of the hydration shell, which is thought to be responsible for the effects observed on proteins and phospholipids.
Simulation results, especially on hydrogen-bond networking, spatial correlations, and self-diffusivity, are
consistent with NMR data and agree well with previous numerical studies on similar solutions. The methods
employed allow the elucidation of the microscopic features of the solutions. For TBA solutions, the hydration
shell is found to have a low density and a large spatial spread, and thus, above the molar fraction of 0.03,
reduction of hydrophobic hydration drives self-aggregation of the solute. This effect does not take place in
TMAO solutions, where the hydration shell is more compact and stable, maintaining its structure over a
wider range of solute concentrations
Proceedings of the LREC 2020 workshop on Resources and Techniques for User and Author Profiling in Abusive Language (ResT-UP 2020)
No full textThis volume documents the Proceedings of the 1st Workshop on Resources and Techniques for User and Author Profiling in Abusive Language (ResT-UP), held online on 12 May 2020 as part of the LREC 2020 conference (International Conference on Language Resources and Evaluation).
The workshop aimed at bringing together researchers and scholars working on author profiling and automatic detection of abusive language on the Web, e.g., cyberbullying or hate speech, with a twofold objective: improving the existing LRs, e.g., datasets, corpora, lexicons, and sharing ideas on stylometry techniques and features needed for profile information extraction and classification. ResT-UP targeted Profiling scholars and research groups, experts in Statistic and Stylistic Analysis of texts as well as computational linguists who investigate author profile and personality both in short texts (social media posts, blog texts and email) and in long texts (such as pamphlets, (fake) news and political documents). ReST-UP represented an opportunity to share profiling experiments with the scientific community and to show automatic detection techniques of abusive language on the Web. Despite the cancellation of LREC 2020 due to the COVID-19 international emergency, ResT-UP was organized online on Microsoft Teams on May 12th 2020 and the programme included three oral presentations and featured an invited talk by Paolo Rosso. ResT-UP was attended by about fifty representatives of academic and industrial organisations
Understanding interaction properties in b-lactoglobulin in solution
No full textWe are studying the effects of increasing pressures on b-lactoglobuline (BLG), a protein belonging to the lipocaline family whose function in vivo is still unclear. Small Angle Neutron and X-Ray Scattering (SANS and SAXS) experiments have been performed to evaluate both structural modification and protein–protein effective interactions in different experimental conditions
Slavo, romanzo, germanico. A proposito di alcune somiglianze e differenze nello sviluppo fonologico
No full textRaffaele Caldarelli
Slavic, Romance,Germanic: about some Similarities and Differences in Phonological Development
In this paper the author aims at drawing a sketch of some aspects of the early Slavic phonological development, in terms of syllable structure, vocal quantity etc. The natural theory of syllabifi cation is taken into account as well as other factors. He tries also to shed some light on several controversial questions by a brief attempt at making a typological comparison between some aspects of phonological development in Slavic, Romance and Germanic languages. In this frame he discusses mainly some features of syllable structure in Romance and Germanic languages
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