An infrared spectroscopy study of the conformational evolution of the Bis(trifluoromethanesulfonyl)imide ion in the liquid and in the glass state

We measure the far-infrared spectrum of N,N-Dimethyl-N-ethyl-N-benzylammonium (DEBA) bis(trifluoromethanesulfonyl) imide (TFSI) ionic liquid (IL) in the temperature range between 160 and 307 K. Differential scanning calorimetry measurements indicate that such IL undergoes a glass transition around 210K. DFT calculations allow us to assign all the experimental absorptions to specific vibrations of the DEBA cation or of the two conformers of the TFSI anion. We find that the vibration frequencies calculated by means of the PBE0 functional are in better agreement with the experimental ones than those calculated at the B3LYP level, largely used for the attribution of vibration lines of ionic liquids. Experimentally we show that, in the liquid state, the relative concentrations of the two conformers of TFSI depend on temperature through the Boltzmann factor and the energy separation, ΔH, is found to be ≈2 kJ/mol, in agreement with previous calculations and literature. However, in the glassy state, the concentrations of the cis-TFSI and trans-TFSI remain fixed, witnessing the frozen state of this phase

Ultra-wide bandwidth systems for the surveillance of railway crossing Areas

Level crossings are critical elements of railway networks where a large number of accidents take place every year. With the recent enforcement of new and higher safety standards for railway transportation systems, dedicated and reliable technologies for level crossing surveillance must be introduced in order to comply with the safety requirements. In this survey the worldwide problem of level crossing surveillance is addressed, with particular attention to the recent European safety regulations. In this context, the capability of detecting, localizing, and discriminating the vehicle/obstacle that might be entrapped in a level crossing area is considered of paramount importance to save lives, and at the same time avoid costly false alarms. In this article the main solutions available today are illustrated and their pros and cons discussed. In particular, the recent ultra-wide bandwidth technology, combined with proper signal processing and backhauling over the already deployed optical fiber backbone, is shown to represent a promising solution for safety improvement in level crossings

Hydrides as high capacity anodes in lithium cells: an Italian “Futuro in Ricerca di Base FIRB-2010” project

Automotive and stationary energy storage are among the most recently-proposed and still unfulfilled applications for lithium ion devices. Higher energy, power and superior safety standards, well beyond the present state of the art, are actually required to extend the Li-ion battery market to these challenging fields, but such a goal can only be achieved by the development of new materials with improved performances. Focusing on the negative electrode materials, alloying and conversion chemistries have been widely explored in the last decade to circumvent the main weakness of the intercalation processes: the limitation in capacity to one or at most two lithium atoms per host formula unit. Among all of the many proposed conversion chemistries, hydrides have been proposed and investigated since 2008. In lithium cells, these materials undergo a conversion reaction that gives metallic nanoparticles surrounded by an amorphous matrix of LiH. Among all of the reported conversion materials, hydrides have outstanding theoretical properties and have been only marginally explored, thus making this class of materials an interesting playground for both fundamental and applied research. In this review, we illustrate the most relevant results achieved in the frame of the Italian National Research Project FIRB 2010 Futuro in Ricerca “Hydrides as high capacity anodes in lithium cells” and possible future perspectives of research for this class of materials in electrochemical energy storage devices

SARS-CoV-2 Infection Incidence and Outcome Before and After Full Vaccination in Patients With Monoclonal Gammopathy of Undetermined Significance

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Off-label long acting injectable antipsychotics in real-world clinical practice: a cross-sectional analysis of prescriptive patterns from the STAR Network DEPOT study

Introduction Information on the off-label use of Long-Acting Injectable (LAI) antipsychotics in the real world is lacking. In this study, we aimed to identify the sociodemographic and clinical features of patients treated with on- vs off-label LAIs and predictors of off-label First- or Second-Generation Antipsychotic (FGA vs. SGA) LAI choice in everyday clinical practice. Method In a naturalistic national cohort of 449 patients who initiated LAI treatment in the STAR Network Depot Study, two groups were identified based on off- or on-label prescriptions. A multivariate logistic regression analysis was used to test several clinically relevant variables and identify those associated with the choice of FGA vs SGA prescription in the off-label group. Results SGA LAIs were more commonly prescribed in everyday practice, without significant differences in their on- and off-label use. Approximately 1 in 4 patients received an off-label prescription. In the off-label group, the most frequent diagnoses were bipolar disorder (67.5%) or any personality disorder (23.7%). FGA vs SGA LAI choice was significantly associated with BPRS thought disorder (OR = 1.22, CI95% 1.04 to 1.43, p = 0.015) and hostility/suspiciousness (OR = 0.83, CI95% 0.71 to 0.97, p = 0.017) dimensions. The likelihood of receiving an SGA LAI grew steadily with the increase of the BPRS thought disturbance score. Conversely, a preference towards prescribing an FGA was observed with higher scores at the BPRS hostility/suspiciousness subscale. Conclusion Our study is the first to identify predictors of FGA vs SGA choice in patients treated with off-label LAI antipsychotics. Demographic characteristics, i.e. age, sex, and substance/alcohol use co-morbidities did not appear to influence the choice towards FGAs or SGAs. Despite a lack of evidence, clinicians tend to favour FGA over SGA LAIs in bipolar or personality disorder patients with relevant hostility. Further research is needed to evaluate treatment adherence and clinical effectiveness of these prescriptive patterns

The Role of Attitudes Toward Medication and Treatment Adherence in the Clinical Response to LAIs: Findings From the STAR Network Depot Study

Background: Long-acting injectable (LAI) antipsychotics are efficacious in managing psychotic symptoms in people affected by severe mental disorders, such as schizophrenia and bipolar disorder. The present study aimed to investigate whether attitude toward treatment and treatment adherence represent predictors of symptoms changes over time. Methods: The STAR Network \u201cDepot Study\u201d was a naturalistic, multicenter, observational, prospective study that enrolled people initiating a LAI without restrictions on diagnosis, clinical severity or setting. Participants from 32 Italian centers were assessed at three time points: baseline, 6-month, and 12-month follow-up. Psychopathological symptoms, attitude toward medication and treatment adherence were measured using the Brief Psychiatric Rating Scale (BPRS), the Drug Attitude Inventory (DAI-10) and the Kemp's 7-point scale, respectively. Linear mixed-effects models were used to evaluate whether attitude toward medication and treatment adherence independently predicted symptoms changes over time. Analyses were conducted on the overall sample and then stratified according to the baseline severity (BPRS < 41 or BPRS 65 41). Results: We included 461 participants of which 276 were males. The majority of participants had received a primary diagnosis of a schizophrenia spectrum disorder (71.80%) and initiated a treatment with a second-generation LAI (69.63%). BPRS, DAI-10, and Kemp's scale scores improved over time. Six linear regressions\u2014conducted considering the outcome and predictors at baseline, 6-month, and 12-month follow-up independently\u2014showed that both DAI-10 and Kemp's scale negatively associated with BPRS scores at the three considered time points. Linear mixed-effects models conducted on the overall sample did not show any significant association between attitude toward medication or treatment adherence and changes in psychiatric symptoms over time. However, after stratification according to baseline severity, we found that both DAI-10 and Kemp's scale negatively predicted changes in BPRS scores at 12-month follow-up regardless of baseline severity. The association at 6-month follow-up was confirmed only in the group with moderate or severe symptoms at baseline. Conclusion: Our findings corroborate the importance of improving the quality of relationship between clinicians and patients. Shared decision making and thorough discussions about benefits and side effects may improve the outcome in patients with severe mental disorders

Optical and magnetic study on iron based multiferroics

Nous présentons une contribution à l’étude des propriétés structurales, électroniques et magnétiques de composés multiferroïques – c’est à dire de matériaux dans lesquels coexistent ordre magnétique et ordre ferroélectrique ; les deux aspects étant couplés via des interactions et mécanismes microscopiques qui ne sont pas encore compris. C’est dans ce contexte que nous avons étudié les deux composés GaFeO₃ et LuFe₂O₄. L’étude a nécessité l’utilisation de plusieurs techniques expérimentales : les mesures magnétiques locales par résonance paramagnétique électronique (RPE) et macroscopiques par magnétométrie , et la spectroscopie infrarouge (IR). Du point de vue du magnétisme de GaFeO₃, les mesures locales et macroscopiques révèlent un comportement inusuel sur un large intervalle de température au-dessus de la température d’ordre, que nous attribuons à l’existence de corrélations magnétiques de courte portée dans la phase paramagnétique. D’autre part,l’analyse des spectres de phonon IR en fonction de la température montre que la mise en ordre des moments magnétiques n’affecte pas les propriétés structurales de GaFeO₃. Le cas de LuFe₂O₄ est très différent puisque les degrés de liberté magnétiques semblent couplés aux propriétés structurales au travers de l’ordre de charge des ions Fe³+/Fe²+ comme le suggèrent les mesures RPE et de spectroscopie IR dans le domaine sub-terahertz.We present a contribution to the study of structural, electronic and magnetic propertiesof multiferroic compounds. These materials – characterized by the coexistence and coupling of different types of long-range orders, such as magnetic and ferroelectic – have recently become a subject of great importance because of their academic interest and their significance for potential applications. In this context we have studied the two compounds GaFeO₃ and LuFe₂O₄. The study involved the use of several techniques : electronic spin resonance (ESR), magnetic measurements by magnetometry and infrared spectroscopy (IR).Local and macroscopic magnetic measurements reveal an anomalous paramagnetic phase in GaFeO3. This is attributed to the existence of short-range magnetic correlations in a wide temperature range above the ordering temperature. On the other hand, the analysis of IR phonon spectra recorded at different temperatures (10 ≤ T ≤ 1000 K) shows that the ordering of magnetic moments does not affect the structural properties of GaFeO₃ For LuFe₂O₄, conversely, the magnetic degrees of freedom are coupled to the structural properties via the charge ordering of Fe³+/Fe²+ ions, as suggested by ESR and IR spectroscopy

A study of the conformers of the N,N-diethyl-N-methyl-N-propylammonium ion by means of infrared spectroscopy and DFT calculations

The infrared absorption spectrum of the N,N-diethyl-N-methyl-N-propylammonium (DMPA) bis (fluorosulfonyl)imide (FSI) ionic liquid is measured as a function of temperature between 165 and 307 K. In the frequency range between 900 and 1070 cm1 only the cation gives rise to infrared bands. A conformational analysis of DMPA is performed by means of DFT calculations at the B3LYP/6-31G** level. The comparison of the experimental and calculated spectra provides evidence that the lowest energy conformers coexist in the liquid. Experimentally, we find that the energy difference between the most stable rotamer and the next energy conformers is only 1.56 0.05 kJ/mol, in good agreement with the calculated value. Finally, we show that in the solid state only the most stable isomer is retained

Relaxation Dynamics and Phase Transitions in Ionic Liquids: Viscoelastic Properties from the Liquid to the Solid State

In the present work we performed low-frequency mechanical spectroscopy experiments to measure the mechanical modulus of two ionic liquids and its variation during the main phase transitions occurring by varying the temperature, in the both liquid and the solid states. The liquids share the same anion, the bis(trifluoromethanesulfonyl)imide, and present different cations, 1- butyl-1-methylpyrrolidinium and 1-allyl-3-H-imidazolium. A thermally activated relaxation process is found in the liquid phase and is analyzed in terms of a modified Debye model. The obtained parameters provide indications about the nature and the mechanism giving rise to the peak, which is attributed to the ions motion by means of hopping processes. Moreover, density functional calculations were performed, and the comparison with the analysis of the experimental data suggests that the anion conformers are likely to be involved in the different configurations among which the ions can rearrange

Propriétés optiques et magnétiques de matériaux multiferroïques (gaFeO3 et LuFe2O4.)

Nous présentons une contribution à l étude des propriétés structurales, électroniques et magnétiques de composés multiferroïques c est à dire de matériaux dans lesquels coexistent ordre magnétique et ordre ferroélectrique ; les deux aspects étant couplés via des interactions et mécanismes microscopiques qui ne sont pas encore compris. C est dans ce contexte que nous avons étudié les deux composés GaFeO et LuFe O . L étude a nécessité l utilisation de plusieurs techniques expérimentales : les mesures magnétiques locales par résonance paramagnétique électronique (RPE) et macroscopiques par magnétométrie , et la spectroscopie infrarouge (IR). Du point de vue du magnétisme de GaFeO , les mesures locales et macroscopiques révèlent un comportement inusuel sur un large intervalle de température au-dessus de la température d ordre, que nous attribuons à l existence de corrélations magnétiques de courte portée dans la phase paramagnétique. D autre part,l analyse des spectres de phonon IR en fonction de la température montre que la mise en ordre des moments magnétiques n affecte pas les propriétés structurales de GaFeO . Le cas de LuFe O est très différent puisque les degrés de liberté magnétiques semblent couplés aux propriétés structurales au travers de l ordre de charge des ions Fe +/Fe + comme le suggèrent les mesures RPE et de spectroscopie IR dans le domaine sub-terahertz.We present a contribution to the study of structural, electronic and magnetic propertiesof multiferroic compounds. These materials characterized by the coexistence and coupling of different types of long-range orders, such as magnetic and ferroelectic have recently become a subject of great importance because of their academic interest and their significance for potential applications. In this context we have studied the two compounds GaFeO and LuFe O . The study involved the use of several techniques : electronic spin resonance (ESR), magnetic measurements by magnetometry and infrared spectroscopy (IR).Local and macroscopic magnetic measurements reveal an anomalous paramagnetic phase in GaFeO3. This is attributed to the existence of short-range magnetic correlations in a wide temperature range above the ordering temperature. On the other hand, the analysis of IR phonon spectra recorded at different temperatures (10 <= T <= 1000 K) shows that the ordering of magnetic moments does not affect the structural properties of GaFeO For LuFe O , conversely, the magnetic degrees of freedom are coupled to the structural properties via the charge ordering of Fe +/Fe + ions, as suggested by ESR and IR spectroscopy.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF