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Background To evaluate the medium and long-term anatomical results of sacrospinous ligament fixation (SLF) and its impact on quality of life (QoL). Methods We conducted a retrospective and observational single centre study. Fifty-nine patients were interviewed using the Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire and underwent physical examination using POP-Q several years after SLF. Primary outcome was the comparison of anatomic results of SLF at medium-term (group 1: 1–5 years after surgery) and long-term (group 2: more than 5 years after surgery). The secondary outcome was QoL evaluation. Results The overall recurrence and complication rates were respectively 22% and 10%, with no significant differences between groups 1 and 2. The recurrence rate was similar in both groups [twelve (35%) in group 1 and nine (20%) in group 2, p = 0.09]. Two patients (12%) in the recurrence and none in the no recurrence group had clinical symptoms (p = 0.08). Two patients (12%) in the recurrence and one patient (2%) in the no-recurrence group had a significant impact on their quality of life (p = 0.12). Conclusion This study showed sustainable anatomic and functional results of SLF in medium and long-term analysis with overall low morbidity.

The dissection of the veins is the trickiest step of Uterine transplantation (UTx). Performing the anastomosis of a single uterine vein could bring a therapeutic benefit and simplification of surgery and serve for managing unilateral venous thromboses. The objectives of this project were to evaluate the expression of early markers of ischemia-reperfusion and to compare findings following one or two vein anastomoses. Orthotopic uterine auto-transplantations were performed on an ovine model with anastomosis of either two (group 1) or one utero-ovarian veins (group 2). Blood gases, histology and ischemia- reperfusion markers transcripts (PTGS2, IL6, IL8, SOD2, C3, BAX/BCL2 and TLR4) were analyzed as well as PTGS2 protein expression using Western Blot and fluorescence immunolocalization on endometrial biopsies after 3h of reperfusion. Ten ewes were included in the experimentation, 4 were in group1, 3 in group 2, the others being sham operated controls. No significant differences were observed between the two phenotypes. Based on these results, the anastomosis of one single uterine vein appears to be an approach consistent with short-term graft survival. Further experiments will be needed to confirm the reliability of this approach, especially the long-term follow-up of the uterine graft including its ability to support gestation to term.

Objective This study focuses on changes in gynecologic surgical activity at Hospital Foch, Paris, France during the first French COVID lockdown in 2020. Additional goals include the evaluation the extent of the postponement suffered for each type of surgery and estimate the possible negative impact for patients. Study design Single-center, retrospective, chart-review cohort study in the gynecology department of Hospital Foch. Comparison of all patients scheduled, postponed and operated during the first COVID lockdown (March 14, to May 11, 2020) versus the same period in 2019. Postponed surgeries were classified into 4 scheduling interval categories according to the Society of Gynecology Oncology (SGO) recommendations: urgent (without delay), semi-urgent (1-4 weeks), non-urgent (>4-12 weeks) and elective (>3 months) and evaluated to determine whether COVID-19-related delays of surgeries fell within guidelines. The potential "loss of chance" or medical risk associated with postponed surgeries was estimated according to a composite criterion including death, aggravation of expected tumor stages/grades in cancers, increase in surgical complexity compared to that initially planned, need for preoperative transfusions, start of morphine consumption during preoperative treatment for opiate-naive patients, additional hospitalization or consultations in emergency room and delay in treatment when surgery was urgent. Results During the 2020 French COVID lockdown, 61 patients had a surgical procedure and 114 were postponed; in the comparator 2019 group, 232 patients underwent surgical procedures, indicating an overall decrease of 65% of activity. Analysis of differences between the two years revealed a reduction of 64% in emergency procedures, 90% of functional pathologies, and 13% of cancers. According to SGO guidelines, the only type of surgical procedures that had excessive delay was the semi-urgent group, where time to surgery was 6.7 weeks [range 5.4-10 weeks] instead of the recommended interval of 1-4 weeks. Among postponed surgeries there were 10 patients (8.7%) with a potential "loss of chance" according to the composite criteria, all included in the semi-urgent group. Conclusion The COVID 19 pandemic was responsible for a significant decrease of activity in the surgical department of Hospital Foch. Difficulty of rescheduling surgeries was responsible for an increased delay in semi-urgent operations. In almost 9% of postponed surgeries, there was a potential "loss of chance", which likely represents only the tip of iceberg of collateral damages due to COVID 19 pandemic in this surgical unit. These data show the importance of continuing to treat pathologies requiring urgent or semi-urgent surgery during pandemics.

The topological state that emerges at the surface of a topological insulator (TI) and at the TI-substrate interface are studied in metal-hBN-Bi2Se3 capacitors. By measuring the RF admittance of the capacitors versus gate voltage, we extract the compressibility of the Dirac state located at a gated TI surface. We show that even in the presence of an ungated surface that hosts a trivial electron accumulation layer, the other gated surface always exhibits an ambipolar effect in the quantum capacitance. We succeed in determining the velocity of surface Dirac fermions in two devices, one with a passivated surface and the other with a free surface that hosts trivial states. Our results demonstrate the potential of RF quantum capacitance techniques to probe surface states of systems in the presence of a parasitic density-of-states., Comment: J. Phys.: Mater. Focus on Topological Matter

Uterus transplantation: state of knowledge and ethical reflection. Nowadays is uterine transplantation the only treatment for absolute uterine infertility. This experimental surgery is spreading worldwide since the past two years. The first livebirths from uterus transplantations from living donors in Sweden gave the impetus for more research. Since several team works on the uterine transplantation from living or deceased donors. Uterus transplantation and the choice between live and deceased donor raises up technical and ethical questions.Greffe utérine : état des lieux et réflexion éthique. La greffe utérine est à ce jour le seul traitement de la stérilité d’origine utérine. Cette chirurgie expérimentale est en expansion à travers le monde, en particulier depuis ces deux dernières années. L’élan a été donné par les premières naissances obtenues en Suède en 2014 à l’issue de greffes à partir de donneuses vivantes. Depuis, plusieurs équipes travaillent sur la greffe à partir de donneuses vivantes mais également en état de mort encéphalique. La greffe utérine en tant que telle ainsi que le choix entre les donneuses vivantes et décédées soulèvent de nombreuses questions techniques et éthiques.

Background and objectives Robotic surgery data need a setback on many years of practice with high-volume surgeons to evaluate its real value. Our main objective was to study the impact of a decade of robotic surgery on minimally-invasive hysterectomies for benign indications. Our secondary objectives were to evaluate our results for high-volume surgeons and complex cases. Methods In this retrospective cohort study, we reviewed medical records at Foch Hospital, from 2010 to 2019, to evaluate the outcomes of robotic hysterectomies for benign disease. We compared the trends of benign hysterectomies done by laparoscopy and laparotomy during this period. We analyzed the proficiency group (≥ 75 cases per surgeon) and complex cases including obese patients and large uteri (>250 g). Results 495 hysterectomies were performed by robotic, 275 by laparotomy, and 130 by laparoscopy. The laparotomy approach decreased from 62% to 29%, whereas the robotic approach increased from 26% to 61%. The operating room (OR) time decreased in the proficiency group (157.3 ± 43.32 versus 178.6 ± 48.05, P = 0.005); whereas the uterine weight was higher (194.6 ± 158.6 versus 161.3 ± 139.4, P = 0.04). Lower EBL and shorter OR time were seen with uteri ≤ 250 g subgroup (64.24 ± 110.2 ml versus 116.63 ± 146.98 ml, P = 0.0004) (169.62 ± 47.50 min versus 192.44 ± 45.82 min, P = 0.0001). The estimated blood loss (EBL) was less in the BMI ≤ 30 subgroup (68.83 ± 119.24 ml versus 124.53 ± 186.14 ml, P = 0.0005). Conclusion A shift was observed between the laparotomy and robotic approaches. High-volume surgeons were more efficient and showed a decrease in OR time after 75 cases despite an increase in uterine weight.

National audience

A metal-dielectric topological-insulator capacitor device based on hexagonal-boron-nitrate-(h-BN) encapsulated CVD-grown Bi 2 Se 3 is realized and investigated in the radio-frequency regime. The rf quantum capacitance and device resistance are extracted for frequencies as high as 10 GHz and studied as a function of the applied gate voltage. The superior quality h-BN gate dielectric combined with the optimized transport characteristics of CVD-grown Bi 2 Se 3 (n ∼ 10 18 cm −3 in 8 nm) on h-BN allow us to attain a bulk depleted regime by dielectric gating. A quantum-capacitance minimum and a linear variation of the capacitance with the chemical potential are observed revealing a Dirac regime. The topological surface state in proximity to the gate is seen to reach charge neutrality, but the bottom surface state remains charged and capacitively coupled to the top via the insulating bulk. Our work paves the way toward implementation of topological materials in rf devices.

International audience; A metal-dielectric topological-insulator capacitor device based on hexagonal-boron-nitrate-(h-BN) encapsulated CVD-grown Bi 2 Se 3 is realized and investigated in the radio-frequency regime. The rf quantum capacitance and device resistance are extracted for frequencies as high as 10 GHz and studied as a function of the applied gate voltage. The superior quality h-BN gate dielectric combined with the optimized transport characteristics of CVD-grown Bi 2 Se 3 (n ∼ 10 18 cm −3 in 8 nm) on h-BN allow us to attain a bulk depleted regime by dielectric gating. A quantum-capacitance minimum and a linear variation of the capacitance with the chemical potential are observed revealing a Dirac regime. The topological surface state in proximity to the gate is seen to reach charge neutrality, but the bottom surface state remains charged and capacitively coupled to the top via the insulating bulk. Our work paves the way toward implementation of topological materials in rf devices.

Uterine transplantation is the solution to treat absolute uterine fertility. In this review, we present the historical, medical, technical, psychological and ethical perspectives in human uterine transplantation research. We reviewed the PubMed database following PRISMA guidelines and added data presented by several research teams during the first international congress on uterine transplantation.

It is well established that topological insulators sustain Dirac fermion surface states as a consequence of band inversion in the bulk. These states have a helical spin polarization and a linear dispersion with large Fermi velocity. In this article we report on a set of experimental observations indicating the existence of massive surface states. These states are confined at the interface and dominate equilibrium and transport properties at high energy and/or high electric field. By monitoring the AC admittance of HgTe topological insulator field-effect capacitors, we access the compressibility and conductivity of surface states in a broad range of energy and electric fields. The Dirac surface states are characterized by a compressibility minimum, a linear energy dependence and a high mobility persisting up to energies much larger than the transport bandgap of the bulk. New features are revealed at high energies with signatures such as conductance peaks, compressibility bumps, a strong charge metastability and a Hall resistance anomaly. These features point to the existence of excited massive surface states, responsible for a strong intersubband scattering with the Dirac states and the nucleation of metastable bulk carriers. The spectrum of excited states agrees with predictions of a phenomenological model of the topological-trivial semiconductor interface. The model accounts for the finite interface depth and the effect of electric fields. The existence of excited topological states is essential for the understanding of topological phases and opens a route for engineering and exploiting topological resources in quantum technology., Comment: 29 pages, 8 figures

We show that a smooth interface between two insulators of opposite topological Z2 indices possesses multiple surface states, both massless and massive. While the massless surface state is non-degenerate, chiral and insensitive to the interface potential, the massive surface states only appear for a sufficiently smooth heterojunction. The surface states are particle-hole symmetric and a voltage drop reveals their intrinsic relativistic nature, similarly to Landau bands of Dirac electrons in a magnetic field. We discuss the relevance of the massive Dirac surface states in recent ARPES and transport experiments., Comment: 5 pages, 3 figures; 6 pages of supplementary material incorporated; accepted for publication in Physical Review B as a Rapid Communication

This thesis discusses the electronic compressibility of two representative three dimensional topological insulators: Strained mercury telluride (HgTe) and bismuth selenide (Bi2Se3).I present low temperature phase-sensitive electron admittance data over a broad frequency range. This allows to extract the quantum capacitance related to the density of states and the resistivity of the investigated materials.We show that the response of an intrinsic topological insulator is dominated by topological surface states over a large energy range exceeding the bulk material’s transport gap. This regime, named “Dirac screening” is characterized by an electron compressibility proportional to the surface Fermi level and a high mobility.Subsequently, we investigate the limits of this regime. At high energy and large perpendicular electric fields we observe the population of excited massive surface states. Experimentally, these manifest themselves in multiple signatures: A drop in the electronic diffusion constant, a peak in the conductivity, appearance of a second carrier type in magneto-transport and meta-stability in the charge-voltage relation.A theoretical model based on a quasi-relativistic treatment of the surface Hamiltonian is presented. It allows to identify the electric field and energy dependence of the massive surface states.This thesis is complemented by experimental results on Bi2Se3 grown on boron nitride, where we demonstrate the importance of clean surfaces for the study of electronic properties in topological insulators., Dans cette thèse, j’étudie la compressibilité électronique de deux isolants topologiques tridimensionnels : Le tellurure de mercure (HgTe) sous contrainte et le séléniure de bismuth (Bi2Se3).Je présente des mesures d’admittance électronique à basse température résolues en phase sur une large gamme de fréquence. Cela permet d’extraire la capacité quantique associé à la densité d’états et la résistivité des matériaux étudiés.Nous montrons qu’un isolant topologique intrinsèque présente une réponse dominée par les états de surface topologiques sur une large gamme d’énergie qui s’étend au-delà du gap de transport du matériau massif. Ce régime, appelé « écrantage de Dirac », est caractérisé par une compressibilité électronique proportionnelle à l’énergie de surface et une haute mobilité.Dans la suite, nous nous intéressons à la limite de ce régime. Nous observons qu’à haute énergie et sous l’influence de forts champs électriques perpendiculaires, des états excités massifs de surface sont peuplés ce qui se manifeste expérimentalement de différentes façons : Une chute dans la constante de diffusion électronique, un pic de conductivité ainsi que l’apparition d’un deuxième type de porteurs en magnéto-transport et de métastabilité dans la relation charge-tension.Un modèle théorique basé sur un traitement quasi-relativiste du Hamiltonien de surface est présenté. Il permet d’identifier la dépendance en énergie et champ électrique des états massifs de surface.Cette thèse est complémenté par des résultats expérimentaux sur Bi2Se3 obtenu par croissance sur nitrure de bore mettent en évidence l’importance de la pureté des interfaces d’isolants topologiques.

The paradigm of graphene transistors is based on the gate modulation of the channel carrier density by means of a local channel gate. This standard architecture is subject to the scaling limit of the channel length and further restrictions due to access and contact resistances impeding the device performance. We propose a novel design, overcoming these issues by implementing additional local gates underneath the contact region which allow a full control of the Klein barrier taking place at the contact edge. In particular, our work demonstrates the GHz operation of transistors driven by independent contact gates. We benchmark the standard channel and novel contact gating and report for the later dynamical transconductance levels at the state of the art. Our finding may find applications in electronics and optoelectronics whenever there is need to control independently the Fermi level and the electrostatic potential of electronic sources or to get rid of cumbersome local channel gates.

Dirac fermions in condensed matter physics hold great promise for novel fundamental physics, quantum devices and data storage applications. IV-VI semiconductors, in the inverted regime, have been recently shown to exhibit massless topological surface Dirac fermions protected by crystalline symmetry, as well as massive bulk Dirac fermions. Under a strong magnetic field (B), both surface and bulk states are quantized into Landau levels that disperse as B^1/2, and are thus difficult to distinguish. In this work, magneto-optical absorption is used to probe the Landau levels of high mobility Bi-doped Pb0.54Sn0.46Te topological crystalline insulator (111)-oriented films. The high mobility achieved in these thin film structures allows us to probe and distinguish the Landau levels of both surface and bulk Dirac fermions and extract valuable quantitative information about their physical properties. This work paves the way for future magnetooptical and electronic transport experiments aimed at manipulating the band topology of such materials., supplementary material included, to appear in Scientific Reports

We propose a device that allows for the emission of pairs of spin-polarized electrons into the edge-states of a two dimensional topological insulator. Charge and spin emission is achieved using a periodically driven quantum dot weakly coupled to the edge states of the host topological insulator. We present calculations of the emitted time-dependent charge and spin currents of such a dynamical scatterer using the Floquet scattering matrix approach. Experimental signatures of spin-polarized two-particle emission can be found in noise measurements. Here a new form of noise suppression, named $\mathbb{Z}_2$--antibunching, is introduced. Additionally, we propose a set-up in which entanglement of the emitted electrons is generated. This entanglement is based on a post-selection procedure and becomes manifest in a violation of a Clauser-Horne-Shimony-Holt inequality., 10 pages + 7 figures

It has always been a basic principle of biomimicry to not just copy natural ideals. But instead of transferring all the possible advantages of natural solutions into our restricted human technologies as biomimicry is doing today, we should try to reconnect our productions and therefore ourselves further back with our natural origin. Resulting from this approach it has to be proven if the exploitation of living material and the use of genetically engineered life-forms in an architectural context is able to minimize the mismatch between human exploitation of unlasting ressources of our planet and the adherence oft the cycle of nature. The following paper investigates the potentials of living materials and structures for an architectural purpose.