A safe and simple solution for intravesical tension-free vaginal tape erosion: removal by standard transurethral resection

OBJECTIVE: To report our experience with the successful removal of visible tension-free vaginal tape (TVT) by standard transurethral electroresection, as intravesical tape erosion after TVT is a rare complication, and removal can be challenging, with few cases reported. PATIENTS AND METHODS: Five patients presenting with TVT erosion into the bladder were treated at our institutions from December 2004 to July 2007; all had standard transurethral electroresection. Their records were reviewed retrospectively to retrieve data on presenting symptoms, diagnostic tests, surgical procedures and outcomes. RESULTS: The median (range) interval between the TVT procedure and the onset of symptoms was 17 (1-32) months. The predominant symptoms were painful micturition, recurrent urinary tract infection (UTI), urgency and urge incontinence. There were no complications during surgery. The storage symptoms and UTI resolved completely after removing the eroded mesh in all but one patient. Cystoscopy at 1 month after surgery showed complete healing of the bladder mucosa. CONCLUSION: Although TVT erosion into the bladder is rare, persistent symptoms, particularly recurrent UTIs, must raise some suspicion for this condition. Standard transurethral electroresection seems to be a safe, simple, minimally invasive and successful treatment option for TVT removal.

Two-dimensional Lattice Gauge Theories with Superconducting Quantum Circuits

A quantum simulator of U(1) lattice gauge theories can be implemented with superconducting circuits. This allows the investigation of confined and deconfined phases in quantum link models, and of valence bond solid and spin liquid phases in quantum dimer models. Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well. Here we show how state-of-the-art superconducting technology allows us to simulate these phenomena in relatively small circuit lattices. By exploiting the strong non-linear couplings between quantized excitations emerging when superconducting qubits are coupled, we show how to engineer gauge invariant Hamiltonians, including ring-exchange and four-body Ising interactions. We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories. The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.

Krapp's Last Tape, un recorrido por las metáforas de la memoria

A partir de la obra de Samuel Beckett Krapp's Last Tape, el presente artículo se propone presentar y revisar críticamente las metáforas de la memoria. A lo largo de la historia, los diferentes pensadores que se refirieron a la memoria hicieron uso de esta figura retórica para explicar su funcionamiento. En la crítica se verá que las metáforas poseen sus limitaciones, si bien pueden sugerir cómo se dan los procesos de almacenamiento y sus funciones, resultan insuficientes ante la cuestión del sentido que brinda la memoria. Así, y a partir de esas críticas, quedará abierto el lugar de la imaginación en nuestra relación con el pasado

Krapp's Last Tape, un recorrido por las metáforas de la memoria

A partir de la obra de Samuel Beckett Krapp's Last Tape, el presente artículo se propone presentar y revisar críticamente las metáforas de la memoria. A lo largo de la historia, los diferentes pensadores que se refirieron a la memoria hicieron uso de esta figura retórica para explicar su funcionamiento. En la crítica se verá que las metáforas poseen sus limitaciones, si bien pueden sugerir cómo se dan los procesos de almacenamiento y sus funciones, resultan insuficientes ante la cuestión del sentido que brinda la memoria. Así, y a partir de esas críticas, quedará abierto el lugar de la imaginación en nuestra relación con el pasado

Krapp's Last Tape, un recorrido por las metáforas de la memoria

A partir de la obra de Samuel Beckett Krapp's Last Tape, el presente artículo se propone presentar y revisar críticamente las metáforas de la memoria. A lo largo de la historia, los diferentes pensadores que se refirieron a la memoria hicieron uso de esta figura retórica para explicar su funcionamiento. En la crítica se verá que las metáforas poseen sus limitaciones, si bien pueden sugerir cómo se dan los procesos de almacenamiento y sus funciones, resultan insuficientes ante la cuestión del sentido que brinda la memoria. Así, y a partir de esas críticas, quedará abierto el lugar de la imaginación en nuestra relación con el pasado

Size and dimensionality effects in superconducting Mo thin films

Molybdenum is a low Tc, type I superconductor whose fundamental properties are poorly known. Its importance as an essential constituent of new high performance radiation detectors, the so-called transition edge sensors (TESs) calls for better characterization of this superconductor, especially in thin film form. Here we report on a study of the basic superconducting features of Mo thin films as a function of their thickness. The resistivity is found to rise and the critical temperature decreases on decreasing film thickness, as expected. More relevant, the critical fields along and perpendicular to the film plane are markedly different, thickness dependent and much larger than the thermodynamic critical field of Mo bulk. These results are consistent with a picture of type II 2D superconducting films, and allow estimates of the fundamental superconducting lengths of Mo. The role of morphology in determining the 2D and type II character of the otherwise type I molybdenum is discussed. The possible consequences of this behaviour on the performance of radiation detectors are also addressed

T-REX: Bare electro-dynamic tape-tether technology experimetn on sounding rocket S520

The project to verify the performance of space tether technology was successfully demonstrated by the launch of the sounding rocket S520 the 25tu. The project is the space demonstration of science and engineering technologies of a bare tape electrodynamic tether (EDT) in the international campaign between Japan, USA, Europe and Australia. Method of "Inverse ORIGAMI (Tape tether folding)" was employed in order to deploy the bare tape EDT in a short period time of the suborbital flight. The deployment of tape tether was tested in a various experimental schemes on ground to show high reliability of tape tether deployment. The rocket was launched on the summer of 2010 and deployed a bare electro-dynamic tape tether with length 132.6 m, which is the world record of the length deployment of tape tether. The verification of tether technology has found a variety kind of science and technology results as the first in the humankind and will lead a large number of applications of space tether technologies

Tape-tether design for de-orbiting from given altitude and inclination

The product of the tether-to-satellite mass ratio and the probability of tether cuts by small debris must be small to make electrodynamic bare tethers a competitive and useful de-orbiting technology. In the case of a circular orbit and assuming a model for the debris population, the product can be written as a function that just depends on the initial orbit parameters (altitude and inclination) and the tether geometry. This formula, which does not contain the time explicitly and ignores the details of the tether dynamics during the de-orbiting, is used to find design rules for the tape dimensions and the orbit parameter ranges where tethers dominate other de-orbiting technologies like rockets, electrical propulsion, and sails.

Role of superconducting shields in electrodynamic propulsion

An electrodynamic tether can propel a spacecraft through a planetary magnetized plasma without using propellant. In the classical embodiment of an electrodynamic tether, the ambient magnetic fleld exerts a Lorentz force on the current along the tether, the ambient plasma providing circuit closure for the current A suggested propulsion scheme would hypothetically eliminate tether performance dependence on the plasma density by using a full wire loop to close the current circuit, and a superconductor to shield a loop segment from the external uniform magnetic fleld and cancel the Lorentz force on that segment. Here, we use basic electromagnetic laws to explain how such a scheme cannot produce a net force. Because there is no net current in the superconducting shield, the circulation of the magnetic field along a closed line outside the full cross section, in its plane, is just due to the current flowing in the loop segment. The presence of the superconducting shield simply moves the Lorentz force from the shielded loop segment to the shield itself and, as a result, the total magnetic force, acting on full loop plus shield, remains zero.

Survival probability of round and tape tethers against debris impact

The current space environment, consisting of manmade debris and micrometeoroids, poses a risk to safe operations in space, and the situation is continuously deteriorating due to in-orbit debris collisions and to new satellite launches. Bare electrodynamic tethers can provide an efficient mechanism for rapid deorbiting of satellites from low Earth orbit at end of life. Because of its particular geometry (length very much larger than cross-sectional dimensions), a tether may have a relatively high risk of being severed by the single impact of small debris. The rates of fatal impact of orbital debris on round and tape tethers of equal length and mass, evaluated with an analytical approximation to debris flux modeled by NASA’s ORDEM2000, shows much higher survival probability for tapes. A comparative numerical analysis using debris flux model ORDEM2000 and ESA’s MASTER2005 validates the analytical result and shows that, for a given time in orbit, a tape has a probability of survival of about one and a half orders of magnitude higher than a round tether of equal mass and length. Because deorbiting from a given altitude is much faster for the tape due to its larger perimeter, its probability of survival in a practical sense is quite high.

Effect of strain and magnetic field on the critical current and electric resistance of the joints between HTS coated conductors

Engineering of devices and systems such as magnets, fault current limiters or cables, based on High Temperature Superconducting wires requires a deep characterization of the possible degradation of their properties by handling at room temperature as well as during the service life thus establishing the limits for building up functional devices and systems. In the present work we report our study regarding the mechanical behavior of spliced joints between commercial HTS coated conductors based on YBCO at room temperature and service temperature, 77 K. Tensile tests under axial stress and the evolution of the critical current and the electric resistance of the joints have been measured. The complete strain contour for the tape and the joint has been obtained by using Digital Image Correlation. Also, tensile tests under external magnetic field have been performed and the effect of the applied field on the critical current and the electric resistance of the joints has been studied. Finally, a preliminary numerical study by means of Finite Element Method (FEM) of the mechanical behavior of the joints between commercial HTS is presented.