RESUMEN

Taking patients' medical history correctly is the basis of diagnosis and therapy. Medical students as a vulnerable group may perceive patient-physician interactions as stressful. This study examines stress among medical students in different degrees of fidelity when taking a patient's medical history. In this longitudinal study, students' stress levels were assessed during scenarios with different degrees of fidelity (role-play, simulated patient encounters and real patient encounters) using standardised questionnaires (State-Trait Anxiety Inventory and a distress scale) and the physiological measurement of heart rate variability. The stress level of participating medical students (N = 128) was expected to significantly increase during scenarios of increasing fidelity (Mroleplay  = 2.08 ± 0.92; SPEs: Msimulatedpatient  = 2.68 ± 1.08; RPEs: Mrealpatient  = 3.35 ± 1.08; p < 0.001). Whereas physiological stress was significantly higher with real patients (N = 106), psychological stress was not affected by the fidelity of the scenarios (N = 85). Medical students experienced stress when taking patients' medical history. Medical students might be unaware of their perceived stress based on the results. Thus, they should know how to cope with stress in such situations.

Asunto(s)

Estudiantes de Medicina , Humanos , Estudios Longitudinales , Estudiantes de Medicina/psicología , Estrés Psicológico/psicología , Encuestas y Cuestionarios

RESUMEN

Magnetic refrigeration is an upcoming technology that could be an alternative to the more than 100-year-old conventional gas-vapor compression cooling. Magnetic refrigeration might answer some of the global challenges linked with the increasing demands for readily available cooling in almost every region of the world and the global-warming potential of conventional refrigerants. Important issues to be solved are, for example, the required mass and the ecological footprint of the rare-earth permanent magnets and the magnetocaloric material, which are key parts of the magnetic cooling device. The majority of existing demonstrators use Nd-Fe-B permanent magnets, which account for more than 50% of the ecological footprint, and Gd, which is a critical raw material. This work shows a solution to these problems by demonstrating the world's first magnetocaloric demonstrator that uses recycled Nd-Fe-B magnets as the magnetic field source, and, as a Gd replacement material, La-Fe-Mn-Si for the magnetocaloric heat exchanger. These solutions show that it is possible to reduce the ecological footprint of magnetic cooling devices and provides magnetic cooling as a green solid-state technology that has the potential to satisfy the rapidly growing global demands.

RESUMEN

Fluorescence lifetime sensing enables researchers to probe the physicochemical environment of a fluorophore providing a window through which we can observe the complex molecular make-up of the cell. Fluorescence lifetime imaging microscopy (FLIM) quantifies and maps cell biochemistry, a complex ensemble of dynamic processes. Unfortunately, typical high-resolution FLIM systems exhibit rather limited acquisition speeds, often insufficient to capture the time evolution of biochemical processes in living cells. Here, we describe the theoretical background that justifies the developments of high-speed single photon counting systems. We show that systems with low dead-times not only result in faster acquisition throughputs but also improved dynamic range and spatial resolution. We also share the implementation of hardware and software as an open platform, show applications of fast FLIM biochemical imaging on living cells and discuss strategies to balance precision and accuracy in FLIM. The recent innovations and commercialisation of fast time-domain FLIM systems are likely to popularise FLIM within the biomedical community, to impact biomedical research positively and to foster the adoption of other FLIM techniques as well. While supporting and indeed pursuing these developments, with this work we also aim to warn the community about the possible shortcomings of fast single photon counting techniques and to highlight strategies to acquire data of high quality.

Asunto(s)

Microscopía/métodos , Análisis de la Célula Individual/métodos , Células HeLa , Humanos , Procesamiento de Imagen Asistido por Computador , Fotones , Factores de Tiempo

RESUMEN

The giant magnetocaloric effect, in which large thermal changes are induced in a material on the application of a magnetic field, can be used for refrigeration applications, such as the cooling of systems from a small to a relatively large scale. However, commercial uptake is limited. We propose an approach to magnetic cooling that rejects the conventional idea that the hysteresis inherent in magnetostructural phase-change materials must be minimized to maximize the reversible magnetocaloric effect. Instead, we introduce a second stimulus, uniaxial stress, so that we can exploit the hysteresis. This allows us to lock-in the ferromagnetic phase as the magnetizing field is removed, which drastically removes the volume of the magnetic field source and so reduces the amount of expensive Nd-Fe-B permanent magnets needed for a magnetic refrigerator. In addition, the mass ratio between the magnetocaloric material and the permanent magnet can be increased, which allows scaling of the cooling power of a device simply by increasing the refrigerant body. The technical feasibility of this hysteresis-positive approach is demonstrated using Ni-Mn-In Heusler alloys. Our study could lead to an enhanced usage of the giant magnetocaloric effect in commercial applications.