Performance of a multianalyte \u27rule-out\u27 assay in pregnant individuals with suspected preeclampsia

BACKGROUND: The ability to diagnose preeclampsia clinically is suboptimal. Our objective was to validate a novel multianalyte assay and characterize its performance, when intended for use as an aid to rule-out preeclampsia. METHODS: Prospective, multicenter cohort study of pregnant individuals presenting between 28 RESULTS: One thousand thirty-six pregnant individuals were enrolled in the study cohort with an incidence of preeclampsia of 30.3% (27.6%-33.2%). The time to develop preeclampsia was shorter for those with an at-risk compared with negative assay result (log-rank CONCLUSIONS: We confirmed that a novel multianalyte assay was associated with the time to develop preeclampsia and has a moderate sensitivity and negative likelihood ratio but high negative predictive value when assessed as an aid to rule out preeclampsia within 7 days of enrollment. REGISTRATION: The study was registered on Clinicaltrials.gov (Identifier NCT02780414)

Nonlinear Transport through Quantum Dots Studied by the Time-Dependent DMRG

Recent developments on studies of transport through quantum dots obtained by applying the time-dependent density matrix renormalization group method are summarized. Some new aspects of Kondo physics which appear in nonequilibrium steady states are discussed both for the single dot case and for the serially coupled double-quantum-dot case.Comment: 8 pages, 15 figure

Formation de poudres carbonées dans un plasma de haute fréquence produit à très basse pression dans des mélanges acétylène-argon

Dusty plasmas are plasmas that contain solid particles of nano- or micrometer size. They are widespread in the cosmic environment and act as precursors in the formation of planets and stars. Such plasmas are also used in laboratories for the synthesis of nanocomposites, which have wide technological and medical applications. While a large scientific effort has been invested in the study and control of such plasmas, the initial growth mechanism of powders (i.e. before they reach several tens of nanometers) remains poorly known. This work contributes primarily to expand the fundamental knowledge in the field of dusty plasmas. Our goal is to understand the physical chemistry of high-frequency plasmas magnetically confined in chemically reactive gases. In addition, we aim by examining the kinetics of the precursors in the plasma to understand the mechanisms of nanoparticle formation in the volume and to control their characteristics in a magnetically confined low pressure Ar/C2H2 plasma. This contribution has a direct impact on science and plasma applications. Among the applications related directly to this research, we mention the synthesis of carbon-based nanocomposites for their integration in solar cells and biomaterials. By examining the plasma characteristics (plasma temperature and density, cation and anion density) and correlating them to those of the dust particles, we found that the magnetic field changes the process of the formation of these particles in the discharge at very low pressure. Specifically, it stimulates the nucleation of carbon nanoparticles through several channels, i.e. through the anions and cations. These nanoparticles include two different phases, an amorphous carbon layer and a porous core formed of grains aggregate. These grains are formed of graphite nanocrystals coated with an amorphous layer. Moreover, the radius of the dust particles increases with the magnetic field, which is related to the enhancement of their residence time in the plasma volume.Les plasmas poudreux sont des plasmas qui contiennent des particules solides de taille nano- ou même micrométrique. Ils sont répandus dans l'environnement cosmique et jouent le rôle de précurseurs dans la formation des planètes et des étoiles. Ce type de plasma est également utilisé dans les laboratoires pour la synthèse des nanocomposites possédant de vastes applications dans le monde technologique et médical. Tandis qu’un grand effort scientifique a été investi dans l’étude et le contrôle de ce type de plasmas, les mécanismes initiaux de formation des poudres (i.e. avant qu’elles atteignent quelques dizaines de nanomètres) demeurent très peu connus. On sait toutefois que des réactions physico-chimiques sont à l’origine de précurseurs des poudres qui déclenchent la nucléation. Ce travail contribue en premier lieu à accroître les connaissances fondamentales dans le domaine des plasmas poudreux en général. Il s’agit en particulier de comprendre la physico-chimie des plasmas de haute fréquence de très basse pression soumis à un confinement magnétique dans des gaz chimiquement réactifs. Plus spécifiquement, l’objectif de ce travail est d’examiner la cinétique des précurseurs produits dans le plasma afin de comprendre les mécanismes de formation de nanoparticules en volume et le contrôle de leurs caractéristiques dans des mélanges d’Ar/C2H2 de très basse pression confinés magnétiquement. Cet apport a des retombées directes en science et applications des plasmas. Parmi les applications directement visées par cette recherche, notons la synthèse de nanomatériaux composites à base de carbone pour leur intégration dans les cellules solaires et les biomatériaux. En examinant les caractéristiques du plasma (température et densité du plasma, densité des cations et des anions) et en les corrélant à celles des particules de poudre, on constate que le champ magnétique modifie le processus de la formation des particules poudreuses dans la décharge à très basse pression. Plus précisément, il favorise la nucléation des nanoparticules de carbone à travers plusieurs voies impliquant les anions et les cations. Ces nanoparticules comprennent deux phases différentes, une couche de carbone amorphe et un noyau poreux formé d'un agrégat de grains eux-mêmes constitués de nanocristaux de graphite revêtus d'une couche amorphe. On constate que le rayon moyen des particules de poudre augmente avec le champ magnétique, ce qui est lié à l’amélioration de leur temps de résidence dans le volume du plasma

The infinite-range quantum random Heisenberg magnet

We study with exact diagonalization techniques the Heisenberg model for a system of SU(2) spins with S=1/2 and random infinite-range exchange interactions. We calculate the critical temperature T_g for the spin-glass to paramagnetic transition. We obtain T_g ~ 0.13, in good agreement with previous quantum Monte Carlo and analytical estimates. We provide a detailed picture for the different kind of excitations which intervene in the dynamical response chi''(w,T) at T=0 and analyze their evolution as T increases. We also calculate the specific heat Cv(T). We find that it displays a smooth maximum at TM ~ 0.25, in good qualitative agreement with experiments. We argue that the fact that TM>Tg is due to a quantum disorder effect.Comment: 17 pages, 14 figure

Intrauterine device is embraced by the placenta

The intrauterine device (IUD) is a contraceptive method which are tiny, T-shaped plastic, that is placed within the uterus and left there, is used all throughout the world with more than 99% effectiveness rate. Pregnancy with a levonorgestrel-releasing intrauterine system (LNG-IUS) in situ is very rare. Intracavitary pregnancy with an IUD can lead to a higher risk of infection and preterm birth. We described a case of a live birth with an IUD inserted into the placenta. A 27-year-old Syrian woman in G4P3 with a history of healthy vaginal deliveries arrived in our delivery room at 39+3 weeks gestation complaining of labor pain A vaginal examination revealed bulging membranes and a fully dilated cervix. She delivered a live baby boy, weighing 3100 g and being sent to the nursery with an APGAR score of 9 to 10. When the placenta was examined, a white foreign object that was embedded there was discovered to be an intrauterine device. Although intrauterine pregnancy is a potential problem that must be taken into account, ectopic pregnancy is a reasonably common complication of intrauterine contraceptive devices. Although several studies have shown that term pregnancies with excellent prognoses can occur after the removal of intrauterine devices, close monitoring is necessary to detect misplaced copper-T and prevent undesired births

Deeply Virtual Compton Scattering Cross Section at High Bjorken \u3csub\u3eB\u3c/sub\u3e

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable B. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of B, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs

Iris-Wasm: robust and modular verification of WebAssembly programs

WebAssembly makes it possible to run C/C++ applications on the web with near-native performance. A WebAssembly program is expressed as a collection of higher-order ML-like modules, which are composed together through a system of explicit imports and exports using a host language, enabling a form of higher- order modular programming. We present Iris-Wasm, a mechanized higher-order separation logic building on a specification of Wasm 1.0 mechanized in Coq and the Iris framework. Using Iris-Wasm, we are able to specify and verify individual modules separately, and then compose them modularly in a simple host language featuring the core operations of the WebAssembly JavaScript Interface. Building on Iris-Wasm, we develop a logical relation that enforces robust safety: unknown, adversarial code can only affect other modules through the functions that they explicitly export. Together, the program logic and the logical relation allow us to formally verify functional correctness of WebAssembly programs, even when they invoke and are invoked by unknown code, thereby demonstrating that WebAssembly enforces strong isolation between modules

Comportement dynamique des ensembles tournants de turbomachines (Maîtrise des effets des dispositifs de liaisonnement amortisseurs)

La fatigue à nombre de cycles élevé (HCF) est un mode de défaillance courant et dangereux pour les aubages de turbomachines. Elle est induite par les efforts dynamiques élevés générés lors de résonances présentes dans la plage de fonctionnement de ces machines. Les dispositifs amortisseurs basés sur l utilisation du frottement sec, tels que les nageoires ou les frotteurs sous-plateformes, permettent de réduire les amplitudes vibratoires, voire de repousser les fréquences de résonance hors des zones de fonctionnement. Cependant la conception de ces dispositifs reste encore largement basée sur l empirisme et ils peuvent être la source d un effet de désaccordage potentiellement nuisible. L objectif ici est de développer des modélisations adaptées au traitement du problème de vibration des aubages en présence de frottement sec, ceci afin de mieux maîtriser les comportements physiques mis en jeu et donc, de mieux maîtriser leur processus de conception. Plusieurs modélisations numériques sont testées et confrontées à des résultats de référence. Une comparaison entre procédures de résolution temporelle et fréquentielle est menée et montre l efficacité des méthodes fréquentielles. La méthode fréquentielle de la balance harmonique à plusieurs harmoniques est adaptée au problème et exploitée dans le cadre d une étude énergétique. Cette étude conduit à une meilleure compréhension des phénomènes mis en jeu lors de l aplatissement des pics en fonctionnement ; elle permet de démontrer que l alternance des états de contact glissant et bloqué est à l origine de cet aplatissement et non la dissipation d énergie comme souvent avancé dans la littérature. Enfin, la méthode est exploitée pour décrire le comportement des disques aubés désaccordés. La méthode de Monte Carlo est utilisée pour obtenir les caractéristiques statistiques de la réponse forcée d un système discret, en tenant compte des variations stochastiques des paramètres du contact notamment, la charge normale, la raideur du contact et le coefficient de frottement. Les résultats obtenus permettent de mieux comprendre les effets de la nature variable de ces paramètres fondamentaux sur la dynamique d ensemble du système non linéaire.Fatigue with high number of cycles (HCF) is a current and dangerous mode of failure for the blades of turbo shaft engines. It is induced by the high dynamic stresses generated at resonance in the operating range of these machines. The rubbing devices based on use of dry friction, such as shrouds or under-platform dampers, make it possible to reduce the vibratory amplitudes, to even push back the resonance frequencies out of the operation zones. However the design of these devices remains still largely based on empiricism and they can be the source of a potentially harmful effect of mistuning. The goal is to develop adapted modelling for the treatment of blades vibration problem in the presence of dry friction, this in order to better control the concerned physical behaviours and thus, to better control their process of design. Several numerical modelling are tested and confronted with reference results. A comparison between procedures of time and frequency domains resolution is carried out and shows the effectiveness of frequential methods. The frequential method of the Harmonic Balance including several harmonics is adapted to the problem and is used within an energy study. This study leads to a better comprehension of the phenomena of peaks flattening and it shows that the alternation of the states of slipping and sticking contact is the real cause of this flattening and not energy dissipation like often advanced in the literature. Lastly, the method is exploited to describe the behaviour of mistuned bladed disks. The Monte Carlo method is used to obtain the statistical characteristics of the forced response for a lumped system, by taking account of the stochastic variations of parameters in the contact, specifically the normal load, the stiffness of the contact and the coefficient of friction. Results obtained make it possible to better include/understand the effects of the variable nature of these fundamental parameters on dynamics of nonlinear system.VILLEURBANNE-DOC'INSA-Bib. elec. (692669901) / SudocSudocFranceF

Moving object tracking in clinical scenarios: application to cardiac surgery and cerebral aneurysm clipping.

BACKGROUND AND OBJECTIVES: Surgical procedures such as laparoscopic and robotic surgeries are popular since they are invasive in nature and use miniaturized surgical instruments for small incisions. Tracking of the instruments (graspers, needle drivers) and field of view from the stereoscopic camera during surgery could further help the surgeons to remain focussed and reduce the probability of committing any mistakes. Tracking is usually preferred in computerized video surveillance, traffic monitoring, military surveillance system, and vehicle navigation. Despite the numerous efforts over the last few years, object tracking still remains an open research problem, mainly due to motion blur, image noise, lack of image texture, and occlusion. Most of the existing object tracking methods are time-consuming and less accurate when the input video contains high volume of information and more number of instruments. METHODS:This paper presents a variational framework to track the motion of moving objects in surgery videos. The key contributions are as follows: (1) A denoising method using stochastic resonance in maximal overlap discrete wavelet transform is proposed and (2) a robust energy functional based on Bhattacharyya coefficient to match the target region in the first frame of the input sequence with the subsequent frames using a similarity metric is developed. A modified affine transformation-based registration is used to estimate the motion of the features following an active contour-based segmentation method to converge the contour resulted from the registration process. RESULTS AND CONCLUSION:The proposed method has been implemented on publicly available databases; the results are found satisfactory. Overlap index (OI) is used to evaluate the tracking performance, and the maximum OI is found to be 76% and 88% on private data and public data sequences