Bladder perivascular epithelioid cell tumors

Introduction: Perivascular epithelioid cell tumors (PEComas) of the bladder are infrequent localisation of this mesenchymal cancer with uncertain malignant behavior.Case report: We report the case of a 74 years old women who was diagnosed a malignant PEComa of the bladder. She necessited radical cystectomy with orthotopic ileocaecal pouch reconstruction. Histology and immunohistochemistry confirmed the diagnosis of a malignant PEComa of the bladder. We evaluate the literature cases to adjust the prognosis criteria.Conclusion: Evolution and prognosis evaluation remain hard and could necessitate a radical surgery. Prognosis criteria for the bladder PEComas have to be clarified

The Generalized Problematic Internet Use Scale-2 in a French sample: psychometric evaluation of the theoretical model

Objectives: The Generalized Problematic Internet Use Scale-2 (GPIUS-2) is a short self-report questionnaire assessing Internet addiction based on a cognitive behavioral model. Our main goal was to evaluate the psychometric properties of its French version among a sample of students and to appraise the relevance of the generalized problematic Internet use model. Methods: A sample of 563 university students aged between 18 and 35 years (M = 20.8; SD = 2.7) completed several online self-report questionnaires including the GPIUS-2, the Internet Addiction Test (IAT) and the Center for Epidemiologic Study-Depression scale (CES-D). Results: Confirmatory Factorial Analyses revealed a poor but acceptable overall fit for the original five-factor model and the original four-factor model. Path analyses, testing Structural Equation Modeling provided showed a poor fit to the data, suggesting insufficient construct validity. Convergent and concurrent validities analyzed through correlational analyses revealed significant relationships between the GPIUS-2, its factors, the IAT, time spent online and the CES-D. Conclusions: This research highlights the insufficient psychometric properties of the GPIUS-2 in a French sample, similar to previous results. However, this French version appears to be a useful multidimensional tool for assessing problematic Internet use among students, and reveals promise for future research and clinical applications of the measure, given its solid theoretical basis and despite the results of this psychometric study

Noncontact orientation of objects in three-dimensional space using magnetic levitation

This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media.Chemistry and Chemical Biolog

The Electrical Resistance of AgTS-S(CH2)n-1CH3//Ga2O3/EGaIn Tunneling Junctions

Tunneling junctions having the structure AgTS–S(CH2)n−1CH3//Ga2O3/EGaIn allow physical–organic studies of charge transport across self-assembled monolayers (SAMs). In ambient conditions, the surface of the liquid metal electrode (EGaIn, 75.5 wt % Ga, 24.5 wt % In, mp 15.7 °C) oxidizes and adsorbs―like other high-energy surfaces―adventitious contaminants. The interface between the EGaIn and the SAM thus includes a film of metal oxide, and probably also organic material adsorbed on this film; this interface will influence the properties and operation of the junctions. A combination of structural, chemical, and electrical characterizations leads to four conclusions about AgTS–S(CH2)n−1CH3//Ga2O3/EGaIn junctions. (i) The oxide is ∼0.7 nm thick on average, is composed mostly of Ga2O3, and appears to be self-limiting in its growth. (ii) The structure and composition (but not necessarily the contact area) of the junctions are conserved from junction to junction. (iii) The transport of charge through the junctions is dominated by the alkanethiolate SAM and not by the oxide or by the contaminants. (iv) The interface between the oxide and the eutectic alloy is rough at the micrometer scale.Chemistry and Chemical Biolog

Noncontact orientation of objects in three-dimensional space using magnetic levitation

International audienceThis paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media

Well separated trion and neutral excitons on superacid treated MoS<inf>2</inf> monolayers

Developments in optoelectronics and spin-optronics based on transition metal dichalcogenide monolayers (MLs) need materials with efficient optical emission and well-defined transition energies. In as-exfoliated MoS2 MLs, the photoluminescence (PL) spectra even at low temperature consist typically of broad, overlapping contributions from neutral, charged excitons (trions) and localized states. Here, we show that in superacid treated MoS2 MLs, the PL intensity increases by up to 60 times at room temperature. The neutral and charged exciton transitions are spectrally well separated in PL and reflectivity at T = 4 K, with linewidth for the neutral exciton of 15 meV, but both transitions have similar intensities compared to the ones in as-exfoliated MLs at the same temperature. Time resolved experiments uncover picoseconds recombination dynamics analyzed separately for charged and neutral exciton emissions. Using the chiral interband selection rules, we demonstrate optically induced valley polarization for both complexes and valley coherence for only the neutral exciton