The usefulness of the dexamethasone suppression test (DST) in the prediction of treatment response to selective antidepressants was tested in 56 major depressive inpatients. Following DST, patients were randomly assigned to treatment by either nomifensine, a catecholaminergic antidepressant, or zimeldine, a serotonergic antidepressant during a 3-week period and assessed by means of the second part of the Clinical Global Impressions (CGI-2). No significant difference was present between the 27 DST suppressor and the 29 DST non-suppressor patients in their overall clinical outcome. Moreover, no preferential response to nomifensine or zimeldine was noted in any of the two groups defined according to DST status. Therefore, these results do not support the usefulness of the DST in the prediction of the treatment response to antidepressants in general and to selective antidepressants in particular.

Since the 1950s, sexual surgical reassignments have been frequently carried out. As this surgical therapeutic procedure is controversial, it seems important to explore the actual consequences of such an intervention and objectively evaluate its relevance. In this context, we have carried out a review of the literature. After looking at the methodological limitations of follow-up studies, the psychological, sexual, social, and professional futures of the individuals subject to a transsexual operation are presented. Finally, prognostic aspects are considered. In the literature, follow-up studies tend to show that surgical transformations have positive consequences for the subjects. In the majority of cases, transsexuals are very satisfied with their intervention and any difficulties experienced are often temporary and disappear within a year after the surgical transformation. Studies show that there is less than 1% of regrets, and a little more than 1% of suicides among operated subjects. The empirical research does not confirm the opinion that suicide is strongly associated with surgical transformation.

The aim of this open trial was to assess the antidepressant/anxiolytic effects of oxytocin used as an adjunct to antidepressant in treatment-resistant depression. Fourteen patients, who have not responded to 40 mg of escitalopram, received intranasal synthetic oxytocin during 4 weeks, in association with antidepressant. This is the first open trial study suggesting OT in association with escitalopram significantly reduced scores on Hamilton Depression Rating Scale.

The mechanical response of modern alloys results from a complex interplay between existing microstructure and its evolution with time under stress. To unravel these processes, in situ approaches intrinsically have a critical advantage to explore the basic mechanisms involving dislocations, grain boundaries (GBs), and their interactions in real time. In this article, we discuss recent findings using in situ nanomechanical testing techniques and refined crystallographic analysis tools. Advancements in in situ nanomechanics not only include multiaxial loading conditions, which bring us closer to real-world applications, but also high strain-rate testing, which is critical to compare experiments and simulations. In particular, unraveling the details of GB-based mechanisms and related microstructural changes will facilitate significant breakthroughs in our understanding of the behavior of materials on macroscopic length scales.

In situ transmission electron microscopy (TEM) nanomechanicaltesting has benefited from a number of recent technical developments related toboth how deformation is imaged and how deformation is induced and measuredinside a TEM instrument. These developments have led to new insights into thedeformation mechanisms of a wide range of metals and alloys, as well asmeasurements of the unusual mechanical properties of small-scale objects such aswhiskers and nanocrystals. Herein, we describe this recent progress throughselected highlights of recent findings on the dynamic behavior of defects suchas dislocations, twins, and grain boundaries.

Magnetophosphenes are described as flickering lights appearing in the visual field, dueto retinal exposure to time-varying magnetic fields (MF). Human magnetophospheneperception (MP) serves as a scientific basis for international guidelines intending tolimit exposure to electromagnetic fields in the extremely low frequency range. However,the flux density threshold at which MP occurs, as well as the dose and frequency responsesof the phenomenon, are not clearly experimentally established. The 50–60 Hz threshold isextrapolated from data in the lower frequency range. The objective of this paper is toprovide a descriptive anecdotal report of MP from 8 individuals exposed to 50 mT MF at 20,50 and 60 Hz. They describe variations of flickering light perceptions in the visualfield, matching the description by D’Arsonval (1896). This preliminary testing introduces a new experimental protocol, which willtest the threshold for MP and other associated neurophysiological responses in humans.

This article is devoted to recent progress in the area of in situ electron microscopy (scanning and transmission) and will focus on quantitative aspects of these techniques as applied to the deformation of materials. Selected recent experiments are chosen to illustrate how these techniques have benefited from improvements ranging from sample preparation to digital image acquisition. Known for its ability to capture the underlying phenomena of plastic deformation as they occur, in situ electron microscopy has evolved to a level where fully instrumented micro- and nanomechanical tests can be performed simultaneously.

Desde la década de 1950, se han llevado a cabo con frecuencia reasignaciones quirúrgicas de sexo. Como este procedimiento terapéutico quirúrgico es polémico, parece importante explorar las consecuencias reales de esta intervención y evaluar objetivamente su pertinencia. En este contexto, hemos llevado a cabo una revisión de las publicaciones. Después de examinar las limitaciones metodológicas de los estudios de seguimiento, se presenta el futuro psicológico, sexual, social y profesional de los individuos sometidos a una intervención quirúrgica transexual. Por último, se consideran aspectos pronósticos. En las publicaciones, los estudios de seguimiento tienden a mostrar que las transformaciones quirúrgicas tienen consecuencias positivas para los sujetos. En la mayoría de los casos, los transexuales están muy satisfechos con su intervención y cualquier dificultad experimentada es a menudo pasajera y desaparece en un plazo de un año después de la transformación quirúrgica. Los estudios muestran que hay menos de un 1% de arrepentimientos, y un poco más de un 1% de suicidios entre los sujetos operados. La investigación empírica no confirma la opinión de que el suicidio está fuertemente asociado con la transformación quirúrgica.

Tension compression fatigue tests and subsequent TEM observations were conducted on single crystalline silicon in a temperature and strain rate domain where lattice friction is still effective: 800-900°C and 1.5 to 6x10-4s-1. Samples oriented for single slip conditions were cyclically loaded under plastic strain amplitude control. For amplitudes ranging from 6x10-4 to 10-2, cyclic stress-strain curves exhibit two different stages of hardening and pass through a maximum before saturation is reached. TEM observations suggest that strain localization takes place near the maximum cyclic stress and beyond. Before mechanical saturation, edge dislocation dipoles sit mainly in thick rectilinear walls. Once the maximum stress is reached, these thick walls “condense” in much thinner walls that seem to carry out the imposed deformation while other regions become inactive. In this case, the dislocation structure anneals out and a loop structure is created from the dipolar walls.

Plastic deformation due to thermal stresses has been investigated for different metallic films deposited on Si or α-alumina substrates. We conducted post-mortem TEM and SEM investigations of samples that underwent thermal cycles in order to capture the microstructural changes imposed by thermal stresses. The ultimate goal is to determine the dominant plasticity mechanisms responsible for such changes. In-situ thermal cycles performed inside the TEM allowed direct and real-time observations of dislocation behaviour under stress. It is shown that dislocation density drops in Al/Si, Au/Si and in Cu/α-alumina thin film systems. Except in the case of pseudo-epitaxial Cu on sapphire, the interaction of dislocations with the interfaces (passivation, oxide, adhesion layer) is attractive and leads to the disappearance of interfacial dislocations. In this light, the generalized observation of high tensile stresses that arise in metallic films at the end of cooling is explained in terms of insufficient dislocation sources instead of classic strain hardening. Diffusional processes can substitute for a lack of dislocation, but the low relaxation strain rate that would be excpected should lead to high stresses during the cooling stages of thermal cycles.

An oscillatory instability mechanism is identified for a horizontal liquid layer with undeformable open surface heated from the air side. Although buoyancy and surface tension gradients are expected to play a stabilizing role in this situation, we show that, acting together, they may lead to the instability of the motionless state of the system. The instability is a consequence of the coupling between internal and surface waves, whose resonant interaction and resulting mode mixing are discussed. Predictions amenable to experimental test are given together with a thorough analytical and numerical study of the problem.

In situ transmission electron microscopy (TEM) was performed to study dislocation motion during temperature cycles in aluminum films passivated with a SiO2 layer. The films were cycled from room temperature to 450 °C. Wedge-haped cross-sectional TEM samples were used to retain the constraint of the Si substrate. Besides interactions between dislocations and interfaces, the movement of threading dislocations within the constrained aluminum film was observed. This observation provides an experimental corroboration of the occurrence of threading dislocation motion, which is the basis for rationalizing the high-ield strength of thin films in available models of thin-film plasticity.

This paper presents the first experimental results on Marangoni–Bénard instability in a symmetrical three-layer system. A pure thermocapillary phenomenon has been observed by performing the experiment in a microgravity environment where buoyancy forces can be neglected. This configuration enables the hydrodynamic stability of two identical liquid–liquid interfaces subjected to a normal gradient of temperature to be studied. The flow is driven by one interface only and obeys the criterion based on the heat diffusivity ratio proposed by Scriven & Sternling (1959) and Smith (1966). The measured critical temperature difference for the onset of convection is compared to the value obtained from two-dimensional numerical simulations. The results of the simulations are in reasonable agreement with the velocimetry and the thermal experimental data for moderate supercriticality. Numerically and experimentally, the convective pattern exhibits a transition between different convective regimes for similar temperature gradients. Their common detailed features are discussed.

The vast majority of micro electro-mechanical systems fabricated today depend on polycrystalline silicon thin films for structural support. Studies involving the mechanical performance of these thin films have progressed to the point where the elastic properties and tensile strength of the films can routinely be measured using a specially designed microsample tensile testing machine. However, a fundamental understanding to predict the mechanical behavior of the polycrystalline silicon films requires that these experimental measurements be complemented with detailed observations of the underlying thin film microstructure. This paper describes some of the plan view and cross-section transmission electron microscope observations that have been performed on different deposition runs of double layer polycrystalline films obtained from the Microelectronics Center of North Carolina. The emphasis has been placed on determining the flatness and dimensions of the polycrystalline films, grain morphology and distribution, texture, and dislocation substructure and microtwinning in the undeformed films.