Transport Properties of Protic Ionic Liquids Based on Triazolium and Imidazolium: Development of an Air-Free Conductivity Setup.

The dynamical properties of four protic ionic liquids, based on the ethyltriazolium ([C2HTr124]) and the ethylimidazolium ([C2HIm]) cation, were investigated. The associated anions were the triflate ([TfO]) and the bistriflimide ([TFSI]). Ionic conductivity values and self-diffusion coefficients were measured and discussed, extending the discussion to the concept of fragility. Furthermore, in order to allow the measurement of the ionic conductivity of very small volumes (<0.5 mL) of ionic liquid under an inert and dry atmosphere, a new setup was developed. It was found that the cation nature strongly affected the transport properties, the [C2HTr124] cation resulting in slower dynamics than the [C2HIm] one. This was concluded from both conductivity and diffusivity measurements while for both properties, the anion had a lesser effect. By fitting the conductivity data with the Vogel-Fulcher-Tammann (VFT) equation, we could also estimate the fragility of these ionic liquids, which all fell in the range of very fragile glass-forming materials. Finally, the slower dynamics observed in the triazolium-based ionic liquids can be rationalized by the stronger interactions that this cation establishes with both anions, as deduced from the frequency analysis of relevant Raman signatures and density functional theory (DFT) calculations.

Charge transfer and electrical double layer of an amphiphilic protic ionic liquid in bulk and when confined in nanochannels.

We report the behavior of the protic and surface active ionic liquid octylimidazolium bis(trifluoromethylsulfonyl)imide, [HC8Im][TFSI], in bulk and inside silica nanochannels, at the interface with the conductive substrate indium tin oxide (ITO) upon applied potential. The two distinct cases of the ionic liquid being in contact with a bare ITO substrate and an ITO substrate covered with a thin film of mesoporous silica containing vertically-aligned channel-like pores have been investigated. These correspond to the behavior of the bulk ionic liquid and the ionic liquid confined within nanochannels (approximately 3.5 nm wide and 65 nm long). Broadband dielectric spectroscopy (BDS) and electrochemical impedance spectroscopy (EIS) have been used as the experimental methods, while modelling with equivalent circuits has been applied to evaluate the experimental results. Thus, this study does not only show a functional ionic liquid/silica hybrid material, but also presents an in-depth electrochemical characterization revealing an enhanced specific capacitance at the confined-IL/ITO interface (∼16 µF cm-2) as compared to the case of bulk IL/ITO (∼6 µF cm-2). This suggests that local structure and ion ordering inside the nanochannels of silica are different from that of the bulk ionic liquid, favoring denser ionic packing and a higher specific capacitance at the metal interface.

A New Solid-State Proton Conductor: The Salt Hydrate Based on Imidazolium and 12-Tungstophosphate.

We report the structure and charge transport properties of a novel solid-state proton conductor obtained by acid-base chemistry via proton transfer from 12-tungstophosphoric acid to imidazole. The resulting material (henceforth named Imid3WP) is a solid salt hydrate that, at room temperature, includes four water molecules per structural unit. To our knowledge, this is the first attempt to tune the properties of a heteropolyacid-based solid-state proton conductor by means of a mixture of water and imidazole, interpolating between water-based and ionic liquid-based proton conductors of high thermal and electrochemical stability. The proton conductivity of Imid3WP·4H2O measured at truly anhydrous conditions reads 0.8 × 10-6 S cm-1 at 322 K, which is higher than the conductivity reported for any other related salt hydrate, despite the lower hydration. In the pseudoanhydrous state, that is, for Imid3WP·2H2O, the proton conductivity is still remarkable and, judging from the low activation energy (Ea = 0.26 eV), attributed to structural diffusion of protons. From complementary X-ray diffraction data, vibrational spectroscopy, and solid-state NMR experiments, the local structure of this salt hydrate was resolved, with imidazolium cations preferably orienting flat on the surface of the tungstophosphate anions, thus achieving a densely packed solid material, and water molecules of hydration that establish extremely strong hydrogen bonds. Computational results confirm these structural details and also evidence that the path of lowest energy for the proton transfer involves primarily imidazole and water molecules, while the proximate Keggin anion contributes with reducing the energy barrier for this particular pathway.

The impact of preoperative anxiety on patients undergoing brain surgery: a systematic review.

Preoperative anxiety is a common reaction exhibited by up to 80% of patients who are scheduled for surgical procedures and characterized by psychological and physical changes which may affect their perioperative period. Our aim is to report the most up-to-date evidence on preoperative anxiety in brain surgery patients through a systematic analysis of the studies produced in the last decades. We performed a systematic review of literature by searching PubMed, Embase, and Cochrane Library databases. Data were extracted using the Population, Intervention, Comparison, Outcome framework and critically analyzed. PRISMA guidelines were applied, and the risk of bias of the included studies was assessed using the Risk of bias (RoB) 2 and ROBINS tools, as was the methodological quality, following GRADE criteria. We included 27 articles, accounting for 2558 patients in twelve different countries. The prevalence of preoperative anxiety ranged from 17 up to 89%, higher in female patients. Preoperative anxiety was associated with lower quality of life and cognitive performance, higher need for information, poorer memory and attention, longer hospitalization, depressive symptoms, and increase of physical disability; no correlation with survival rate was found. Seven randomized controlled trials attested the efficacy of acupuncture, music therapy, virtual reality, and pharmacological support in lowering anxiety levels. Preoperative anxiety is a common phenomenon that could negatively affect the perioperative period of brain surgery patients: this is something that should not be neglected to achieve better care through early prevention and optimal management.

Local anisotropy in single crystals of zeotypes with the MFI framework structure evidenced by polarised Raman spectroscopy.

Polarised Raman spectroscopy is used to characterise the local structure in single crystals of zeotypes, namely silicalite-1 and ZSM-5, which share the MFI framework structure. Attributes favourable for applying polarised Raman spectroscopy are the orthogonal axes of these single crystals and their size, i.e. 10 to 30 micrometers in all three directions. We show that the intensity of certain vibrational modes in silicalite-1 depends on the polarisation of the incident light, reflecting the anisotropic character of the molecular bonds contributing to these vibrations. Using these observations, and by estimating the depolarisation ratio (ρ) and the pseudo-order factor (f), we propose a more accurate assignment of the Raman active modes. More precisely, Raman intensities peaked at 294, 360, 383 and 472 cm-1 are attributed to bending modes in 10-, 6-, 5- and 4-membered rings, respectively. In the region of stretching modes, the vibration at 832 cm-1 is assigned to Si-O-Si bonds shared between 5-membered rings, which have an orientation parallel to the a-axis of the crystal. By virtue of having a strongly polarised character, the modes at 472 and 832 cm-1 can be used as orientational indicators. The proposed assignment is supported by the good agreement between experimental and simulated polar plots, where Raman intensities are plotted as a function of the polarisation angle of the incident light. Finally, upon partial substitution of Si atoms by Al, the crystalline structure is maintained and almost no spectroscopic changes are observed. The only significant difference is the increased width of most vibrational modes, which is consistent with the local lower symmetry. This is also seen in the angular dependence of selected vibrational modes that compared to the case of pure silicalite-1 appear less polarised. In the Raman spectrum of ZSM-5 a new feature at 974 cm-1 is observed, which we attribute to Al-OH stretching. In the high frequency range, the O-H stretching modes are observed which arise from the Si-O(H)-Al Brønsted acid sites. The intensity of the characteristic mode at 3611 cm-1 reveals an anisotropic character as well, which is in line with previous findings from solid state NMR that Al atoms distribute nonrandomly within the MFI framework structure.

Molecular dynamics involving proton exchange of a protic ionic liquid-water mixture studied by NMR spectroscopy.

Protic ionic liquids (PILs) are proposed as alternative anhydrous proton conducting electrolytes for intermediate temperature fuel cells. One of the key factors in their performance as electrolytes, as far as charge transport is concerned, is their proton conductivity. Noting the success of water-containing electrolytes and recognising faster proton mobility than structural relaxation (via mechanisms such as Grotthuss) as their advantage, such an advantage is envisaged for PILs and in some cases deduced. As extended hydrogen bond networks and proton exchange are at the heart of these mechanisms, here we report our results on a prototypical characterisation of proton exchange in a PIL (C2HimNTf2)-water mixture. NMR lineshape analysis and exchange spectroscopy (EXSY) are used to quantify the proton exchange rate. The obtained exchange rate is then used to explain the diffusion behaviour of the exchangeable proton as measured by pulse field gradient NMR methods; a marginal anomaly in the translational dynamics of the exchangeable proton in the form of a faster NH proton is observed. As far as we know this is the first report on systematic characterisation of proton exchange in PILs with the aim of understanding its effect on translational motion as a way of discerning exchange related mobility anomalies.

Transport properties and intermolecular interactions in binary mixtures based on the protic ionic liquid ethylimidazolium triflate and ethylene glycol.

The binary mixture based on the protic ionic liquid (PIL) ethylimidazolium triflate (C2HImTfO) and the diol compound ethylene glycol (EG) has been investigated in the whole composition range from pure PIL to pure EG. At 30 °C the addition of EG increases both the ionic conductivity and the self-diffusivity of the ions. These quantities, however, change at different rates suggesting that the ionicity of the system is composition dependent. This behaviour is explained by means of new intermolecular forces established when a second compound like EG is introduced into the ionic network. More specifically, a complex H-bonded network is formed that involves the -NH group of the cation, the -OH group of EG and the -SO3 group of the anion. This configuration may increase the fluidity of the mixture but not necessarily the ionic dissociation. Moreover, diffusion NMR results indicate the occurrence of local proton dynamics, which arise from a proton exchange between the -NH of the cation and the -OH of EG, providing the requisite for a long-range Grotthuss mechanism of proton transport.

Mesostructure and physical properties of aqueous mixtures of the ionic liquid 1-ethyl-3-methyl imidazolium octyl sulfate doped with divalent sulfate salts in the liquid and the mesomorphic states.

This paper extends the study of the induced temperature change in the mesostructure and in the physical properties occurring in aqueous mixtures of the ionic liquid 1-ethyl-3-methyl imidazolium octyl-sulfate [EMIm][OSO4]. For some compositions, these mixtures undergo a phase transition between the liquid (isotropic in the mesoscale) and the mesomorphic state (lyotropic liquid crystalline) at about room temperature. The behavior of mixtures doped with a divalent metal sulfate was investigated in order to observe their applicability as electrolytes. Calcium sulfate salt is almost insoluble even in the 20 wt% water mixture. The magnesium salt, in contrast, can be dissolved up to concentrations of 730 ppm in the same mixture and it has a profound impact on its properties. Six aqueous mixtures (with water content from 10 wt% to 33 wt%) of [EMIm][OSO4] were saturated with magnesium sulfate salt, producing the ternary mixture [EMIm][OSO4] + H2O + MgSO4. Viscosity, density and ionic conductivity for these samples were measured from 10 °C to 90 °C. In addition, SAXS, FTIR, diffussion NMR and Raman spectroscopy of the most interesting samples have been performed, and structural data indicate a transition between a hexagonal lyotropic liquid crystalline phase below and an isotropic solution phase above room temperature. The octyl sulfate anions of the cylindrical micelles in the hexagonal phase are coordinated with water molecules through H-bonds (about four per sulfate anion), while the [EMIm] cations seem to be poorly coordinated and so free to move. Inorganic salt addition reinforces that network, increasing the phase transition temperature.

Achieving enhanced ionic mobility in nanoporous silica by controlled surface interactions.

We report a strategy to enhance the ionic mobility in an emerging class of gels, based on robust nanoporous silica micro-particles, by chemical functionalization of the silica surface. Two very different ionic liquids are used to fill the nano-pores of silica at varying pore filling factors, namely one aprotic imidazolium based (1-methyl-3-hexylimidazolium bis(trifluoromethanesulfonyl)imide, C6C1ImTFSI), and one protic ammonium based (diethylmethylammonium methanesulfonate, DEMAOMs) ionic liquid. Both these ionic liquids display higher ionic mobility when confined in functionalized silica as compared to untreated silica nano-pores, an improvement that is more pronounced at low pore filling factors (i.e. in the nano-sized pore domains) and observed in the whole temperature window investigated (i.e. from -10 to 140 °C). Solid-state NMR, diffusion NMR and dielectric spectroscopy concomitantly demonstrate this effect. The origin of this enhancement is explained in terms of weaker intermolecular interactions and a consequent flipped-ion effect at the silica interface strongly supported by 2D solid-state NMR experiments. The possibility to significantly enhance the ionic mobility by controlling the nature of surface interactions is extremely important in the field of materials science and highlights these structurally tunable gels as promising solid-like electrolytes for use in energy relevant devices. These include, but are not limited to, Li-ion batteries and proton exchange membrane (PEM) fuel cells.

Local coordination and dynamics of a protic ammonium based ionic liquid immobilized in nano-porous silica micro-particles probed by Raman and NMR spectroscopy.

Room temperature ionic liquids confined in a solid material, for example, nano-porous silica, are particularly propitious for energy related applications. The aim of this study is to probe the molecular interactions established between the protic ionic liquid diethylmethylammonium methanesulfonate (DEMA-OMs) and silica, where the latter consists of nano-porous micro-particles with pores in the size range of 10 nm. The changes in the local coordination and transport properties induced by the nano-confinement of the ionic liquid are investigated by a combination of Raman and solid-state NMR spectroscopy. In particular, one-dimensional (1D) (1)H and (29)Si and two-dimensional (2D) (29)Si{(1)H} HETOCR solid-state NMR are combined to identify the sites of interaction at the silica-ionic liquid interface. Pulsed field gradient (PFG) NMR experiments are performed to estimate the self-diffusion of both bulk and nano-confined DEMA-OMs. Complementary information on the overall coordination and interaction scheme is achieved by Raman spectroscopy. All these advanced experimental techniques are revealed to be crucial to differentiate between ionic liquid molecules residing in the inter- or intra-particle domains.

Structural origin of proton mobility in a protic ionic liquid/imidazole mixture: insights from computational and experimental results.

The structure, dynamics, and phase behavior of a binary mixture based on the protic ionic liquid 1-ethylimidazolium bis(trifluoromethanesulfonyl)imide (C2HImTFSI) and imidazole are investigated by (1)H NMR spectroscopy, vibrational spectroscopy, diffusion NMR, calorimetric measurements, and molecular dynamics simulations. Particular attention is given to the nature of the H-bonds established and the consequent occurrence of the Grotthuss mechanism of proton transfer. We find that due to their structural similarity, the imidazolium cation and the imidazole molecule behave as interchangeable and competing sites of interaction for the TFSI anion. All investigated properties, that is the phase behavior, strength of ion-ion and ion-imidazole interactions, number of specific H-bonds, density, and self-diffusivity, are composition dependent and show trend changes at mole fractions of imidazole (χ) approximately equal to 0.2 and 0.5. Beyond χ = 0.8 imidazole is not miscible in C2HImTFSI at room temperature. We find that at the equimolar composition (χ ≈ 0.5) a structural transition occurs from an ionic network mainly stabilized by coulombic forces to a mixed phase held together by site specific H-bonds. The same composition also marks a steeper decrease in density and increase in diffusivity, resulting from the preference of imidazole molecules to H-bond to each other in a chain-like manner. As a result of these structural features the Grotthuss mechanism of proton transfer is less favored at the equimolar composition where H-bonds are too stable. By contrast, the Grotthuss mechanism is more pronounced in the low concentration range where imidazole acts as a base pulling the proton of the imidazolium cation. At high imidazole concentrations the contribution from the vehicular mechanism dominates.

Direct communication between osteocytes and acid-etched titanium implants with a sub-micron topography.

The osteocyte network, through the numerous dendritic processes of osteocytes, is responsible for sensing mechanical loading and orchestrates adaptive bone remodelling by communicating with both the osteoclasts and the osteoblasts. The osteocyte network in the vicinity of implant surfaces provides insight into the bone healing process around metallic implants. Here, we investigate whether osteocytes are able to make an intimate contact with topologically modified, but micrometre smooth (S a < 0.5 µm) implant surfaces, and if sub-micron topography alters the composition of the interfacial tissue. Screw shaped, commercially pure (cp-Ti) titanium implants with (i) machined (S a = ~0.2 µm), and (ii) two-step acid-etched (HF/HNO3 and H2SO4/HCl; S a = ~0.5 µm) surfaces were inserted in Sprague Dawley rat tibia and followed for 28 days. Both surfaces showed similar bone area, while the bone-implant contact was 73 % higher for the acid-etched surface. By resin cast etching, osteocytes were observed to maintain a direct intimate contact with the acid-etched surface. Although well mineralised, the interfacial tissue showed lower Ca/P and apatite-to-collagen ratios at the acid-etched surface, while mineral crystallinity and the carbonate-to-phosphate ratios were comparable for both implant surfaces. The interfacial tissue composition may therefore vary with changes in implant surface topography, independently of the amount of bone formed. Implant surfaces that influence bone to have higher amounts of organic matrix without affecting the crystallinity or the carbonate content of the mineral phase presumably result in a more resilient interfacial tissue, better able to resist crack development during functional loading than densely mineralised bone.

The role of the ionic liquid C6C1ImTFSI in the sol-gel synthesis of silica studied using in situ SAXS and Raman spectroscopy.

The sol-gel synthesis of a silica based ionogel using the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C6C1ImTFSI) as the solvent has been followed in situ by combined µ-focused X-ray scattering and µ-Raman spectroscopy. By covering the momentum transfer range 0.2 < q < 30 nm(-1) we probe the evolution of the characteristic peaks of the ionic liquid, associated with the existence of polar and non-polar domains, as a function of reaction time. Our detailed analysis of the small angle X-ray scattered (SAXS) pattern reveals that the nano-structure of the ionic liquid is partially retained during the sol-gel synthesis, as indicated by the broader yet distinguishable SAXS signatures. We also observe that the signature associated with the non-polar and polar domains shift to higher and lower q-values, respectively. Interestingly, this behavior correlates with the evolution of the chemical composition of the sol as probed by Raman spectroscopy. More precisely, we observe that both the nano-structural changes and the production of polar molecules arrest at the point of gelation. This is rationalized by the tendency of the reagents and products of the sol-gel reaction to locate in different portions of the nano-structure of the ionic liquid.

Surface effects on the structure and mobility of the ionic liquid C6C1ImTFSI in silica gels.

We report on how the dynamical and structural properties of the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C6C1ImTFSI) change upon different degrees of confinement in silica gels. The apparent diffusion coefficients of the individual ions are measured by (1)H and (19)F pulsed field gradient nuclear magnetic resonance (PFG-NMR) spectroscopy, while the intermolecular interactions in the ionogels are elucidated by Raman spectroscopy. In addition, the local structure of the ionic liquid at the silica interface is probed by solid-state NMR spectroscopy. Importantly, we extend this study to a wider range of ionic liquid-to-silica molar ratios (x) than has been investigated previously, from very low (high degree of confinement) to very high (liquid-like gels) ionic liquid contents. Diffusion NMR measurements indicate that a solvation shell, with a significantly lower mobility than the bulk ionic liquid, forms at the silica interface. Additionally, the diffusion of the C6C1Im(+) and TFSI(-) ions decreases more rapidly below an observed molar ratio threshold (x < 1), with the intrinsic difference in the self-diffusion coefficient between the cation and anion becoming less pronounced. For ionic liquid molar ratio of x < 1, Raman spectroscopy reveals a different conformational equilibrium for the TFSI(-) anions compared to the bulk ionic liquid, with an increased population of the cisoid isomers with respect to the transoid. Concomitantly, at these high degrees of confinement the TFSI(-) anion experiences stronger ion-ion interactions as indicated by the evolution of the TFSI(-) characteristic vibrational mode at ∼740 cm(-1). Furthermore, solid-state 2D (29)Si{(1)H} HETCOR NMR measurements establish the interactions of the ionic liquid species with the silica surface, where the presence of adsorbed water results in weaker interactions between (29)Si surface moieties and the hydrophobic alkyl protons of the cationic C6C1Im(+) molecules.

Effects of a protic ionic liquid on the reaction pathway during non-aqueous sol-gel synthesis of silica: a Raman spectroscopic investigation.

The reaction pathway during the formation of silica via a two-component "non-aqueou" sol-gel synthesis is studied by in situ time-resolved Raman spectroscopy. This synthetic route is followed with and without the addition of the protic ionic liquid 1-ethylimidazolium bis(trifluoromethanesulfonyl)imide (C2HImTFSI) in order to investigate its effect on the reaction pathway. We demonstrate that Raman spectroscopy is suitable to discriminate between different silica intermediates, which are produced and consumed at different rates with respect to the point of gelation. We find that half-way to gelation monomers and shorter chains are the most abundant silica species, while the formation of silica rings strongly correlates to the sol-to-gel transition. Thus, curling up of linear chains is here proposed as a plausible mechanism for the formation of small rings. These in turn act as nucleation sites for the condensation of larger rings and thus the formation of the open and polymeric silica network. We find that the protic ionic liquid does not change the reaction pathway per se, but accelerates the cyclization process, intermediated by the faster inclusion of monomeric species.

Large out-of-plane spin-orbit torque in topological Weyl semimetal TaIrTe4.

The unique electronic properties of topological quantum materials, such as protected surface states and exotic quasiparticles, can provide an out-of-plane spin-polarized current needed for external field-free magnetization switching of magnets with perpendicular magnetic anisotropy. Conventional spin-orbit torque (SOT) materials provide only an in-plane spin-polarized current, and recently explored materials with lower crystal symmetries provide very low out-of-plane spin-polarized current components, which are not suitable for energy-efficient SOT applications. Here, we demonstrate a large out-of-plane damping-like SOT at room temperature using the topological Weyl semimetal candidate TaIrTe4 with a lower crystal symmetry. We performed spin-torque ferromagnetic resonance (STFMR) and second harmonic Hall measurements on devices based on TaIrTe4/Ni80Fe20 heterostructures and observed a large out-of-plane damping-like SOT efficiency. The out-of-plane spin Hall conductivity is estimated to be (4.05 ± 0.23)×104 (ℏ / 2e) (Ωm)-1, which is an order of magnitude higher than the reported values in other materials.

An investigation of the sol-gel process in ionic liquid-silica gels by time resolved Raman and 1H NMR spectroscopy.

We report, by employing time resolved Raman and nuclear magnetic resonance (NMR) spectroscopy, on the gelation process in ionogels. These are prepared from a non-aqueous sol-gel reaction in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C(1)C(6)ImTFSI). Raman and NMR spectroscopies are complementarily used to decipher the chemical reactions that occur during synthesis and to clarify the state of the ionic liquid up to, and well beyond, gelation. We find that the ionic liquid concentration affects both the reaction rate and the gelation time (t(gel)). In addition, NMR and Raman data reveal inherently different roles of the cation and the anion in the gelation process. While the oscillating behavior of the TFSI Raman signature at ~740 cm(-1) is mainly an effect of solvation and chemical composition, the evolution of the relative chemical shifts (Δδ) of different hydrogen atoms on the imidazolium correlates with gelation, as does the width of the chemical shift of -OH containing groups (δ(OH)). We also observe that in the confined state the TFSI anion preferably adopts the cisoid conformation and experiences a stronger ion-ion interaction.

Binary Mixtures of Imidazolium-Based Protic Ionic Liquids. Extended Temperature Range of the Liquid State Keeping High Ionic Conductivities.

Binary mixtures based on the two protic ionic liquids 1-ethylimidazolium triflate ([C2HIm][TfO]) and 1-ethylimidazolium bis(trifluoromethanesulfonyl)imide ([C2HIm][TFSI]) have been investigated, with focus on phase behavior, ionic conductivity, and intermolecular interactions as a function of composition (χ TFSI indicating the mole fraction of the added compound). It is found that on addition of [C2HIm][TFSI] to [C2HIm][TfO], the melting temperature is first decreased (0 < χ ≤ 0.3) and then suppressed (0.3 < χ ≤ 0.8) resulting in mixtures with no phase transitions. These mixtures display a wide temperature range of the liquid state and should be interesting for use in devices operating at extreme temperatures. The ionic conductivity does not vary significantly across the composition range analyzed, as evidenced in the comparative Arrhenius plot. The activation energy, E a , estimated by fitting with the Arrhenius relation in a limited temperature range (between 60 and 140 °C) varies marginally and keeps values between 0.17 and 0.21 eV. These marginal differences can be rationalized by the initially very similar values of the two neat protic ionic liquids. Vibrational spectroscopy, including both Raman and infrared spectroscopies, reveals weakening of the cation-anion interactions for increasing content of [C2HIm][TFSI], which is reflected by the blue shift of the average N-H stretching mode and the red shift of the S-O stretching mode in the TfO anion. These trends correlate with the higher disorder in the mixtures observed by DSC and are evidenced by the decrease and suppression of the melting temperature as the amount of [C2HIm][TFSI] is increased.

3'UTR Deletion of NONO Leads to Corpus Callosum Anomaly, Left Ventricular Non-Compaction and Ebstein's Anomaly in a Male Fetus.

NONO (Non-Pou Domain-Containing Octamer-Binding Protein) gene maps on chromosome Xq13.1 and hemizygous loss-of-function nucleotide variants are associated with an emerging syndromic form of intellectual developmental disorder (MRXS34; MIM #300967), characterized by developmental delay, intellectual disability, poor language, dysmorphic facial features, and microcephaly. Structural brain malformation, such as corpus callosum and cerebellar abnormalities, and heart defects, in particular left ventricular non-compaction (LVNC), represent the most recurrent congenital malformations, recorded both in about 80% of patients, and can be considered the distinctive imaging findings of this disorder. We present on a further case of NONO-related disease; prenatally diagnosed in a fetus with complete corpus callosum agenesis; absence of septum pellucidum; pericallosal artery; LVNC and Ebstein's anomaly. A high-resolution microarray analysis demonstrated the presence of a deletion affecting the NONO 3'UTR; leading to a marked hypoexpression of the gene and the complete absence of the protein in cultured amniocytes. This case expands the mutational spectrum of MRXS34, advises to evaluate NONO variants in pre- and postnatal diagnosis of subjects affected by LVNC and other heart defects, especially if associated with corpus callosum anomalies and confirm that CNVs (Copy Number Variants) represent a non-negligible cause of Mendelian disorders.

Mode of birth in women with low-lying placenta: protocol for a prospective multicentre 1:3 matched case-control study in Italy (the MODEL-PLACENTA study).

INTRODUCTION: The term placenta praevia defines a placenta that lies over the internal os, whereas the term low-lying placenta identifies a placenta that is partially implanted in the lower uterine segment with the inferior placental edge located at 1-20 mm from the internal cervical os (internal-os-distance). The most appropriate mode of birth in women with low-lying placenta is still controversial, with the majority of them undergoing caesarean section. The current project aims to evaluate the rate of vaginal birth and caesarean section in labour due to bleeding by offering a trial of labour to all women with an internal-os-distance >5 mm as assessed by transvaginal sonography in the late third trimester. METHODS AND ANALYSIS: The MODEL-PLACENTA is a prospective, multicentre, 1:3 matched case-control study involving 17 Maternity Units across Lombardy and Emilia-Romagna regions, Italy. The study includes women with a placenta located in the lower uterine segment at the second trimester scan. Women with a normally located placenta will be enrolled as controls. A sample size of 30 women with an internal-os-distance >5 mm at the late third trimester scan is needed at each participating Unit. Since the incidence of low-lying placenta decreases from 2% in the second trimester to 0.4% at the end of pregnancy, 150 women should be recruited at each centre at the second trimester scan. A vaginal birth rate ≥60% in women with an internal-os-distance >5 mm will be considered appropriate to start routinely admitting to labour these women. ETHICS AND DISSEMINATION: Ethical approval for the study was given by the Brianza Ethics Committee (No 3157, 2019). Written informed consent will be obtained from study participants. Results will be disseminated by publication in peer-reviewed journals and presentation in international conferences. TRIAL REGISTRATION NUMBER: NCT04827433 (pre-results stage).