Utilidad de la ecografía en el manejo de fluidos y la terapia de transfusión en la hemorragia digestiva en el ámbito de urgencias

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicina. Fecha de lectura: 03-12-201

Morphic and principal-ideal group rings

We observe that the class of left and right artinian left and right morphic rings agrees with the class of artinian principal ideal rings. For $R$ an artinian principal ideal ring and $G$ a group, we characterize when $RG$ is a principal ideal ring; for finite groups $G$, this characterizes when $RG$ is a left and right morphic ring. This extends work of Passman, Sehgal and Fisher in the case when $R$ is a field, and work of Chen, Li, and Zhou on morphic group rings.Comment: 21 page

Sorting with Robots: where to drop off the parcel?

This paper presents a method for assigning destinations to drop off points in robotic sorting systems, taking into account robot congestion

Evaluation of Venous Congestion by Point-of-Care Ultrasound: State of the Art

The assessment of venous congestion is one of the grea-test medical challenges of this century: from more invasive procedures to the arising of ultrasound evaluation, there has been a constant quest for reliable and non-invasive bedside tools to determine and monitor hemodynamic status. Venous hypertension is an important pathophysiological mechanism of organ congestion, leading to its injury in various clinical settings. A practical bedside assessment of venous congestion is often challenging due to the limitations of tradi-tional methods.Point-of-care ultrasonography (POCUS) provides a real time picture of the patients' anatomy and physiology (inclu-ding analysis of dynamic flows), allowing a diagnosis and mo-nitoring of venous congestion with a higher sensitivity than standard physical examination.In this brief summary, the authors summarize the physio-logy of venous congestion and the most recent tools for con-gestion assessment by POCUS.info:eu-repo/semantics/publishedVersio

Nanoaperture fabrication via colloidal lithography for single molecule fluorescence analysis

In single molecule fluorescence studies, background emission from labeled substrates often restricts their concentrations to non-physiological nanomolar values. One approach to address this challenge is the use of zero-mode waveguides (ZMWs), nanoscale holes in a thin metal film that physically and optically confine the observation volume allowing much higher concentrations of fluorescent substrates. Standard fabrication of ZMWs utilizes slow and costly E-beam nano-lithography. Herein, ZMWs are made using a self-assembled mask of polystyrene microspheres, enabling fabrication of thousands of ZMWs in parallel without sophisticated equipment. Polystyrene 1 mu m dia. microbeads self-assemble on a glass slide into a hexagonal array, forming a mask for the deposition of metallic posts in the inter-bead interstices. The width of those interstices (and subsequent posts) is adjusted within 100-300 nm by partially fusing the beads at the polystyrene glass transition temperature. The beads are dissolved in toluene, aluminum or gold cladding is deposited around the posts, and those are dissolved, leaving behind an array ZMWs. Parameter optimization and the performance of the ZMWs are presented. By using colloidal self-assembly, typical laboratories can make use of sub-wavelength ZMW technology avoiding the availability and expense of sophisticated clean-room environments and equipment

Exact Hawking Radiation of Scalars, Fermions, and Bosons Using the Tunneling Method Without Back-Reaction

Hawking radiation is studied for arbitrary scalars, fermions, and spin-1 bosons, using a tunneling approach, to every order in $\hbar$ but ignoring back-reaction effects. It is shown that the additional quantum terms yield no new contribution to the Hawking temperature. Indeed, it is found that the limit of small $\hbar$ in the standard quantum WKB approximation is replaced by the near-horizon limit in the gravitational WKB approach.Comment: 8 pages, no figures. v3: Introduction updated. Version to appear in PL

Hawking Radiation due to Photon and Gravitino Tunneling

Applying the Hamilton--Jacobi method we investigate the tunneling of photon across the event horizon of a static spherically symmetric black hole. The necessity of the gauge condition on the photon field, to derive the semiclassical Hawking temperature, is explicitly shown. Also, the tunneling of photon and gravitino beyond this semiclassical approximation are presented separately. Quantum corrections of the action for both cases are found to be proportional to the semiclassical contribution. Modifications to the Hawking temperature and Bekenstein-Hawking area law are thereby obtained. Using this corrected temperature and Hawking's periodicity argument, the modified metric for the Schwarzschild black hole is given. This corrected version of the metric, upto $\hbar$ order is equivalent to the metric obtained by including one loop back reaction effect. Finally, the coefficient of the leading order correction of entropy is shown to be related to the trace anomaly.Comment: LaTex, 19 pages, no figures, extended version, new references added, to appear in Annals of Phy