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To identify risk factors associated with bladder injury during placenta accreta spectrum (PAS) surgeries.This retrospective cohort study was conducted at the Chaim Sheba Medical Center. The study population included pregnant women diagnosed with PAS undergoing uterine-preserving surgery or hysterectomy. Women with and without operative bladder injury were compared by univariate analysis followed by multivariate analysis. A sub-analysis of women without preoperative sonographic suspicion of bladder invasion was performed.A total of 312 women were included in the study. Bladder injury incidence was 9.3% (n = 29). Uterine preservation was performed in 267/312 (85.6%) women. The number of previous cesarean deliveries and a preoperative sonogram suspicious for placenta percreta were found to be independent risk factors for intraoperative bladder injury (odds ratio [OR] 1.30, P = 0.019, and OR 5.23, P = 0.002, respectively). The number of previous cesarean deliveries and preoperative sonographic suspicion of placenta percreta were also associated with bladder injury in the sub-analysis (OR 1.30, P = 0.044 for previous cesarean deliveries, and OR 3.36, P = 0.036, for preoperative suspicion of bladder injury).The number of previous cesarean deliveries and preoperative suspicion of placenta percreta are preoperative factors that can assist in preoperative planning and intraoperative management of PAS cases.

The aim of this study is to evaluate the effect of uterine exteriorization versus intraperitoneal repair, in first compared to repeat cesarean delivery.A prospective randomized control single-blinded trial conducted in a single tertiary center between March 2014 and March 2015, including 32 and 63 women in first and recurrent cesarean sections, respectively. Inclusion criteria were elective operation and gestational age ≥37 weeks. Operative outcomes were compared between the groups including mean operative time, blood loss, hypotension, perioperative nausea and pain. Post-operative outcomes were further compared, including post-operative analgesia demand, first recognized bowel movement, nausea, length of hospital stay, fever, endometritis surgical site infection rate, and total satisfaction.During the study period, 45 and 50 women were designated for uterine exteriorization and intraperitoneal uterine repair, respectively. Mean blood loss was 452 cc (±10.44) for the extraperitoneal compared to 540 cc (±29.83) for the intraperitoneal uterine repair group (Intraperitoneal repair of uterine incision is associated with higher operative blood loss compared to uterine exteriorization. No other differences in operative and postoperative complication rates were found between the groups.

Introduction The aim of this study is to compare immediate and long-term obstetrical outcomes of patients who underwent cesarean delivery with and without uterine artery embolization (UAE) for the management of placenta accreta spectrum disorder. Material and methods A retrospective case control study including all pregnant women admitted to a single tertiary medical center between December 2001 and May 2018 with a diagnosis of placenta accreta spectrum disorder, who underwent cesarean delivery with and without UAE. Groups were compared for maternal characteristics, operative management, postoperative complication rate and long-term outcomes. Follow up on future obstetrical outcomes was conducted via telephone questionnaire. Non-parametric statistics were used. Results During the study period, 272 women met the inclusion criteria: 64 (23.53%) and 208 (76.47%) underwent preservative cesarean section with and without UAE, respectively. UAE procedure was associated with a longer operative time (82.5 [68-110] vs 50.5 [39-77] minutes; P = .001), and higher blood loss (2000 (1500-3000) vs 1000 (600-2000) mL; P = .001). Hysterectomy rate was comparable between the groups (9 [14%] vs 35 [16.82%]; P = .88); however, multivariate logistic regression analysis found UAE to be an independent factor associated with lower hysterectomy rate (P = .02). Postoperative complications were more frequent in the UAE group. Follow up was achieved in 29 (59.18%) and 72 (51.79%) of the women with and without UAE, respectively (P = .36). No differences were found in rate of abortions, pregnancy and deliveries between the groups. Conclusions Cesarean delivery using UAE in placenta accreta spectrum disorder is associated with a higher rate of operative and postoperative complications. Nevertheless, in cases of severe adherence of the placenta, embolization reduces the need for hysterectomy, allowing future fertility.

A low-temperature reaction of benzyl alcohol/benzyl mercaptan with iron(III) acetylacetonate was used to synthetize micron and submicron-sized materials composed of one-pot mixture of iron oxysulfide and iron oxide. The final compound as well as reference materials greigite and magnetite were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy. The crystal structure, chemical composition, and morphology of the particles of the iron oxysulfide/iron oxide composite were compared to the ones of the references, iron sulfide and iron oxide. The materials showed clear differences both in reduction and oxidation when they were cycled between 0.1–3.0 V or 1.0–3.0 V vs. Li+/Li. In all cases, electrochemical properties of the iron oxysulfide/iron oxide mixture make out to the ones of two reference materials. The in situ XRD investigation of greigite nanoplatelets confirmed that a topotactic reaction occurs between 3.0 and 1.0 V vs. Li+/Li, followed by a conversion reaction at potentials negative to 1.0 V vs. Li+/Li during the first lithiation.

Lithium-rich mixed metal layered oxides constitute a large class of promising high-potential positive electrode materials in which higher specific charges are accessed only by activation of the Li2MnO3 domains. During the activation, oxygen is extracted from the oxide and evolves at the electrode–electrolyte interface. Differential electrochemical mass spectrometry was employed to follow volatile species developed during cycling. Although typical Li-ion aprotic carbonate electrolytes already suffer from oxidative decomposition at high potentials, the presence of O2 is here confirmed to enhance its reactivity. During the first cycle, O2 and CO2 evolve and their respective amounts vary as a function of the cycling conditions. However, for ethylene carbonate-based electrolytes, the amount of O2 and CO2 is found to be independent of the electrolyte composition. Moreover, X-ray photoelectron spectroscopy revealed that carbon-based components of the solid layers are dissolved between 3.0 and 4.0 V versus Li+/Li...

International audience; Centimeter-sized single crystals of Ba2LaFeNb4O15 were grown from a high-temperature solution by using LiBO2 flux and a sealed platinum assembly. The obtained single crystals display the same physical properties as their ceramic counterparts. A frequency-dependent dielectric permittivity maximum was found (Tm = 100 K at 5 kHz), which indicates relaxor behavior. Magnetic susceptibility measurements revealed purely paramagnetic behavior between 10 and 350 K. X-ray diffraction measurements of Ba2LaFeNb4O15 single crystals revealed an incommensurate structure at room temperature with a bidimensional modulation characterized by vectors q1 = (α, α, 1/2) and q2 = (α, -α, 1/2) with α = 0.295(1). This crystal growth method offers a promising elaboration route to centimeter-sized crystals of niobate-based compounds, which may not be grown from the pure liquid phase, especially those with a tetragonal tungsten bronze (TTB) structure.

International audience; Tetragonal Tungsten Bronze Ferroelectrics (TTB) are currently revisited for the elaboration of new multifunctional materials. Recent studies on Ba2LnFeNb4O15 ceramics (Ln=Nd, Sm and Eu) demonstrated that these materials display both ferroelectric and ferromagnetic behaviors at room temperature due to the presence of barium hexaferrite as a secondary phase. In this paper, we report for the first time the growth of Ba2LnFeNb4O15 single crystals (Ln=La, Pr, Nd, Sm and Eu) from high temperature solution using LiBO2 flux. Inclusion free millimeter-sized single crystals were successfully grown. Structural and dielectric characterizations were performed and chemical analysis confirmed that the TTB matrix is reluctant to accommodate small rare earth as it was observed for ceramics. A paramagnetic behavior was observed for all compositions, which corroborates the composite nature of the TTB ceramic multiferroics at room temperature, while dielectric measurements on Ln=La and Pr crystals confirmed their relaxor behavior.

International audience; We have investigated the dielectric response of Ba2PrxNd1-xFeNb4O15 ceramics (x = 0, 0.2, 0.5, 0.6, 0.8, 1) in the frequency range from 20 Hz to 1 GHz. The obtained results confirmed the continuous transformation from the ferroelectric behavior of Ba2NdFeNb4O15 to the pure relaxor response of Ba2PrFeNb4O15 with increasing x. For intermediate x values, coexisting ferroelectric transition and relaxor dielectric signatures were observed, corresponding to two different phenomena in the framework of these materials. Increasing the amount of Pr decreases the ferroelectric phase transition temperatures in these ceramics; a large cooling??heating hysteresis exceeding 50K was also observed.

We have investigated dielectric response of Ba 2 Pr x Nd 1−x FeNb 4 O 15 ceramics (x = 0, 0.2, 0.5, 0.6, 0.8, 1) in the frequency range from 20 Hz to 1 GHz. Obtained results showed a continuous transformation from the ferroelectric behavior of Ba 2 NdFeNb 4 O 15 to the pure relaxor response of Ba 2 PrFeNb 4 O 15 with increasing x. For intermediate x values coexistences of both ferroelectric transition and relaxor dielectric signatures corresponding to two different phenomena in the framework of these materials were observed. The increase of Pr amount lowers ferroelectric phase transition temperatures in these compounds and also a huge cooling-heating hysteresis exceeding 50 K was observed, which origin is under discussion yet.

International audience; Relaxors are very interesting materials but most of the time they are restricted to perovskite materials and thus their flexibility is limited. We have previously shown that tetragonal tungsten bronze (TTB) niobate Ba2PrFeNb4O15 was a relaxor below 170 K and that Ba2NdFeNb4O15 displays a ferroelectric behavior with a TC = 323 K. On scanning the whole solid solution Ba2PrxNd1−xFeNb4O15 (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1), we demonstrate here a continuous crossover between these end member behaviors with a coexistence of ferroelectricity and relaxor in the intermediate range. This tunability is ascribed to the peculiar structure of the TTB networks which is more open than the classical perovskites. This allows for the coexistence of long range and short range orders and thus opens up the range of relaxor materials.

International audience; {Tb3}[Sc2−xLux](Al3)O12 crystals have been grown and investigated for the first time for magneto-optical applications. Tb3Al5O12 exhibits the best magneto-optical features; however, its incongruent melting nature has led to the industrial use of Tb3Ga5O12. Tb3Sc2Al3O12 had been proposed as an alternative to Tb3Al5O12, but unfortunately its growth also presents several drawbacks. The present investigation shows that by the isovalent substitution of Sc3+ by Lu3+ in the octahedral site of the garnet structure, it is possible to improve the growth characteristics while preserving the superior magneto-optical properties. We demonstrate that {Tb3}[Sc2−xLux](Al3)O12 crystals show a higher visible transparency and a larger Faraday rotation than Tb3Ga5O12 crystals. {Tb3}[Sc2−xLux](Al3)O12 is therefore a very promising material in particular for new magneto-optical applications in the visible-near IR wavelength region.

International audience; Recent studies of ceramics of formula Ba2LnFeNb4O15 (Ln=rare earth) with the “tetragonal tungsten bronze” (TTB) structure have correlated their room temperature multiferroics properties to the occurrence of barium ferrite parasitic phases. This work presents the elaboration of Ba2LaFeNb4O15 and Ba2EuFeNb4O15 composite samples with an excess of hematite in the TTB nominal composition. The influence of crystal-chemistry on the phase content and properties of Ba2LnFeNb4O15 TTB composites is discussed. A particular focus on the mechanisms related to the in-situ formation of barium ferrite is given. We show that we can control the spurious ferrite phase in TTB multiferroic composites and thus modulate their magnetic response.

Several Niobium oxides of formula Ba2LnFeNb4O15 (Ln = La, Pr, Nd, Sm, Eu, Gd) with the Tetragonal Tungsten Bronze (TTB) structure have been synthesised by conventional solid-state methods. The Neodymium, Samarium and Europium compounds are ferroelectric with Curie temperature ranging from 320 to 440K. The Praseodymium and Gadolinium compounds behave as relaxors below 170 and 300 K respectively. The Praseodymium, Neodymium, Samarium, Europium and Gadolinium compounds exhibit magnetic hysteresis loops at room temperature originating from traces of a barium ferrite secondary phase. The presence of both ferroelectric and magnetic hysteresis loops at room temperature allows considering these materials as composites multiferroic. Based on crystal-chemical analysis we propose some relationships between the introduction of Ln3+ ions in the TTB framework and the chemical, structural and physical properties of these materials., Revised version after identification of a spurious barium ferrite phase responsible for composite multiferroic properties at RT. Appearance of this parasitic phase is correlated to the crystal-chemistry of the Ba2LnFeNb4O15 TTBs. Submitted to Solid State Sciences. 27 pages, 7 figures, 3 tables

International audience; The present work reports the optimisation of the composition and elaboration process of Ba6−2xLn2xFe1+xNb9−xO30 (0.6 x

Piezoelectric single-crystal ingots of Ca12Al14O33 were grown by Czochralski technique. Upon specific chemical reductions, this dielectric material can be turned into an oxygen solid electrolyte, a mixed conductor, or an electride. We followed the thermal evolution of the piezoelectric performances of as-grown samples and compared it with oxygen and hydrogen annealed ones. The structure of Ca12Al14O33 crystal was studied by powder x ray diffraction patterns, and the chemical processing efficiency was checked by optical transmittance measurements. The dielectric permittivity ɛ11 and piezoelectric coefficient d15 were found to be on the orders of 8–12 and 16–20 pC/N, respectively. This material exhibits good bulk shear wave coupling factor k14 about 0.34 and promising surface acoustic wave (SAW) velocities of 3500 m/s that render it suitable for SAW devices as a substrate. The piezoelectric response of crystals before and after annealing under H2 and O2 is maintained. The observed evolutions may be related to the conductivity of the material or the electrical transport properties, which are known to be sensitive to the oxygen and the hydrogen content.