Search results for "transition"
showing 10 items of 3988 documents
Hydration dependence of myoglobin dynamics studied with elastic neutron scattering, differential scanning calorimetry and broadband dielectric spectr…
2014
In this work we present a thorough investigation of the hydration dependence of myoglobin dynamics. The study is performed on D2O-hydrated protein powders in the hydration range 0<h<0.5 (h≡gr[D2O]/gr[protein]) and in the temperature range 20-300K. The protein equilibrium fluctuations are investigated with Elastic Neutron Scattering using the spectrometer IN13 at ILL (Grenoble), while the relaxations of the protein + hydration water system are investigated with Broadband Dielectric Spectroscopy; finally, Differential Scanning Calorimetry is used to obtain a thermodynamic description of the system. The effect of increasing hydration is to speed up the relaxations of the myoglobin + hydration …
Pressure- and temperature-induced valence tautomeric interconversion in a o-dioxolene adduct of a cobalt-tetraazamacrocycle complex
2001
An electronic switch at the molecular level has been realized by using a class of ionic compounds of the formula [Co(L)(diox)]Y (L = tetraazamacrocyclic ligand, Y = mononegative anion). Such compounds undergo temperature- and pressure-induced intramolecular one-electron transfer equilibria. The transition temperature of interconversion varies with the nature of the counterions Y (Y = PF6, BPh4, I). Surprisingly the effect of the anion on the transition temperature is not only governed by its volume but also by its coulombic interaction.
From Single Molecules to Nanoscopically Structured Materials: Self-Assembly of Metal Chalcogenide/Metal Oxide Nanostructures Based on the Degree of P…
2011
A chemically specific and facile method for the immobilization of metal oxide nanoparticles onto the surface of IF-MoS2 nested fullerenes is reported. The modification strategy is based on the chalcophilic affinity of transition metals such as Fe2+/Fe3+, Fe3+, or Zn2+ as described by the Pearson HSAB concept. The binding capabilities of the 3d metals are dictated by their Pearson hardness. Pearson hard cations such as Fe3+ (Fe2O3) do not bind to the chalcogenide surfaces; borderline metals such as Fe2+ (Fe3O4) or Zn2+ (ZnO) bind reversibly. Pearson-soft metals like Au bind irreversibly. The immobilization of metal oxide nanoparticle colloids was monitored by transmission electron microscopy…
The CdCl2 effects on synthetic DNAs encaged in the nanodomains of a cationic water-in-oil microemulsion
2011
The present work is dedicated to the study of the interactions of CdCl(2) with the synthetic polynucleotides polyAT and polyGC confined in the nanoscopic aqueous compartment of the water-in-oil microemulsion CTAB/pentanol/hexane/water, with the goal to mimic in vitro the situation met by the nucleic acids in vivo. In biological structures, in fact, very long strings of nucleic acids are segregated into very small compartments having a radius exceedingly smaller than the length of the encapsulated macromolecule. For comparison, the behaviour of polyGC was also studied in aqueous solutions of matched composition. The conformational and thermal stabilities of both polynucleotides enclosed in t…
Les formations professionnelles de l'enseignement supérieur en France au prisme de l'insertion et de la mobilité sociale des diplômés
2014
La professionnalisation des formations dans l'enseignement supérieur en France s'est développée ces dernières décennies avec pour objectif d'améliorer l'employabilité des jeunes diplômés dans un contexte de dégradation de leurs conditions d'insertion. À partir des trois dernières enquêtes Génération du Céreq, ce travail questionne la performance de ces filières professionnelles par rapport aux filières plus académiques de l'enseignement supérieur, en période de crise économique. Certaines formations, comme par exemple les licences professionnelles, garantissent toujours de bonnes conditions d'insertion, pour autant les effets concernant la mobilité sociale en début de carrière, sont plus nu…
Geoterminen energia ja politiikkaongelmien hallitsemisen tiedollinen haaste
2022
Ilmastonmuutoksen hillitsemiseksi energiajärjestelmän on muututtava vähähiilisemmäksi. Geoterminen energia on Suomessa ja muualla maailmassa noussut yhdeksi päästöttömäksi uusiutuvan energian muodoksi, mutta sen rakentamiseen ja käyttöön sisältyy riskejä. Tässä artikkelissa tarkastelemme geotermisen energian seismisen riskin hallintaa monitoimijaisessa verkostossa. Keskitymme siihen, millaisena eri toimijat näkevät Seismologian instituutin aseman geotermisen energian hallinnan verkostossa. Pohdimme, miten geotermisen energian seismisen riskin hallinnan kaltainen kompleksinen politiikkaongelma jäsentyy institutionaalisesti epäselvässä tilanteessa ja millaisia tietoon ja tietämiseen liittyviä…
Observatoire de la Transition Socioécologique en Bourgogne Franche-Comté : Méthodes et résultats
2022
Présentation de la méthode et des résultats quantitatif et qualitatifs 2022 de l'étude de l'Observatoire de la Transition Socioécologique en Bourgogne Franche-Comté.
The cross-cultural transition experience. Phenomenological analysis on a group of international students
2010
Summary This study is focused on exploration of experience of cultural transition that has lived a group of international students (European and not European) host at an Italian University during particular experiential segment marking the transition from their culture of belonging to the new social and cultural context. From an epistemological point of view that aligns with the phenomenological tradition with individual and group interviews, it was monitored with a longitudinal methodology as the representation of the transit cross-cultural adaptation to the context it emerged from the interviews are associated through the dominant narrative themes. The results show how in the early stage …
A phase I-II study on intravesical Gemcitabine in superficial bladder papillary tumors
2004
INTRODUCTION AND OBJECTIVE: The possible role of gemcitabine inintravesical therapy of superficial transitional cell carcinoma of the bladder (TCCB) has been suggested. The European Organization for Research and Treatment of Cancer Urological Group validated the use of papillary marker lesion left in the bladder after TUR as the best tool to measure the efficacy of a drug by intravesical route against TCCB. The rsults on 27 patients are herein presented. METHODS: Twenty-seven patients, with recurrent superficial TCCB (Ta-T1, G1-G2), were treated with intravesical gemcitabine for 1 to 3 papillary marker lesions (5-15 mm) left unreseacted after TUR. Twenty-one patients (78%) had recurrent tum…
Ligand-Centred Fluorescence and Electronic Relaxation Cascade at Vibrational Time Scales in Transition-Metal Complexes
2015
Using femtosecond-resolved photoluminescence up-conversion, we report the observation of the fluorescence of the high-lying ligand-centered (LC) electronic state upon 266 nm excitation of an iridium complex, Ir(ppy)(3), with a lifetime of 70 +/- 10 fs. It is accompanied by a simultaneous emission of all lower-lying electronic states, except the lowest triplet metal-to-ligand charge-transfer ((MLCT)-M-3) state that shows a rise on the same time scale. Thus, we observe the departure, the intermediate steps, and the arrival of the relaxation cascade spanning similar to 1.6 eV from the (LC)-L-1 state to the lowest 3MLCT state, which then yields the long-lived luminescence of the molecule. This …