Entire hemithorax irradiation for Masaoka stage IVa thymomas

Thymomas are rare neoplasms that have an indolent growth with a preferentially intra-thoracic dissemination pattern. Surgery is currently the standard treatment of thymomas; however radiotherapy is often used in an adjuvant setting due to a high sensitivity of these tumors to such treatment. Postoperative entire hemithoracic irradiation has been used in selected Masaoka stage IVa cases after complete surgical excision of metastatic lesions. In the present article, the authors report three cases of Masaoka stage IVa thymoma that underwent entire hemithorax irradiation after surgical excision of metastatic lesions. The first two patients presented as stage IVa thymomas. The third case consisted of a pleural recurrence of a thymoma. Hemithoracic irradiation with low doses has been used by different authors; the available data shows that it is a well-tolerated treatment that could potentially lead to better loco-regional control and increased overall survival

Visible Light Communication in Vehicular Communication Applications

This paper addresses the issues related to the Visible Light Communication (VLC) usage in vehicular communication applications. We propose a Visible Light Communication system based on Vehicle-to-Vehicle, Vehicleto-Infrastructure and Infrastructure-to-Vehicle communications able to safely manage vehicles crossing through an intersection. By using the streetlamps, street lights and traffic signaling to broadcast information, the connected vehicles interact with one another and with the infrastructure. Using joint transmission, mobile optical receivers collect data, calculate their location for positioning and, concomitantly, read the transmitted data from each transmitter. As receivers and decoders, optical sensors with light filtering properties, are used. Bidirectional communication between the infrastructure and the vehicles is tested. To command the passage of vehicles safely queue/request/response mechanisms and temporal/space relative pose concepts are used. The results show that the innovative solutions for congested intersections are related to the introduction of split intersections. The results indicate that the V-VLC system increases safety by directly monitoring critical points such as queue formation and dissipation, relative speed thresholds, as well as inter-vehicle spacing.publishersversionpublishe

VLC Based Guidance System to Be Used by Mobile Users Inside Large Buildings

The main goal of this paper is a Visible Light Communication (VLC) based guidance system to be used by mobile users inside large buildings. This system is composed of several transmitters (ceiling luminaries), which transmit map information and path guidance messages. Mobile devices, with VLC support, decode the information. A mesh cellular hybrid structure is proposed. The luminaires, via VLC, deliver their geographic position and specific information to the users, making them available for whatever use they request. The communication protocol, coding/decoding techniques, and error control are examined. Bidirectional communication is implemented and the best route to navigate through venue calculated. We propose several guidance services and multi-person cooperative localization. By analyzing the results, it became clear that the system not only provides self-location, but also the capability to determine the direction of travel and to interact with information received in order to optimize the route towards a static or dynamic destination.publishersversionpublishe

SEMICONDUCTOR DEVICE FOR DETECTION OF FRET SIGNALS

The transducer consists on a semiconductor device based on two stacked-i-n  heterostructures, that were designed to detect the emissions of the fluorescence resonance energy transfer between fluorophores in the cyan (470 nm) and yellow (588 nm) range of the spectrum. This research represents a preliminary study on the use of such wavelength sensitive devices as photodetectors for this kind of application. The device was characterized through optoelectronic measurements concerning spectral response measurements under different electrical and optical biasing conditions. To simulate the FRET pairs a chromatic time dependent combination of cyan and yellow wavelengths was applied to the device. The generated photocurrent was measured under reverse and forward bias to readout the output photocurrent signal. Different wavelength biasing light was also superimposed. Results show that under reverse bias the photocurrent signal presents four separate levels each one assigned to the different wavelength combinations of the FRET pairs. If a blue background is superimposed the yellow channel is enhanced and the cyan suppressed while under red irradiation the opposite behavior occurs. So under suitable biasing light the transducer is able to detect separately the cyan and yellow fluorescence pairs. An electrical model, supported by a numerical simulation supports the transduction mechanism of the device

Use of ultramicroindentation to evaluate the degradation of sputtered coatings

The aim of this research work was to study the influence of chemical degradation on the mechanical properties of the non-degraded zones of sputtered W-N-Ti coatings. For this, an ultramicroindentation technique has been used before and after degradation, either on the zones between the pits in the corroded samples, or on the non-oxidised layers after removal of the top degraded layers. By using different applied loads it was possible to obtain results with and without the influence of the substrate. Thus, two types of results were obtained, those determined by using an empirical model, which eliminates the influence of the substrate, and those measured directly.Very small differences of less than 20% were obtained in the measured values before and after degradation, indicating that the non-degraded zones maintain their as-deposited mechanical properties.http://www.sciencedirect.com/science/article/B6TW4-3VGSFTN-Y/1/d6747ea11390bd13ea164c97933b791

El acoplamiento entre la atmósfera neutra y la ionósfera en la base de la región F ecuatorial

De acuerdo a un modelo de la dinámica de la termósfera ecuatorial previamente introducido por S. Duhau y el autor, la velocidad iónica zonal en la base de la región F cumple una ecuación diferencial que describe su dependencia de las condiciones de un circuito eléctrico formado entre las regiones E y F a través de las líneas de campo geomagnético y del arrastre entre iones y neutros, despreciando el efecto de dicho arrastre sobre la velocidad neutra, con lo cual la ecuación de movimiento de los neutros queda desacoplada de la ecuación para la velocidad iónica. En este trabajo se incluye ese efecto, resolviéndose el sistema de ecuaciones acopiadas resultante, y calculándose asimismo la densidad de corriente intercambiada entre las regiones E y F.According to a model of equatorial thermospheric dynamics previously introduced by S. Duhau and the author, the zonal ion velocity at the base of the F-region satisfies a differential equation that describes its dependence on an electric circuit formed between the E- and F- regions by the geomagnetic field lines, and on the drag between ions and neutrals, the effect of the latter on the neutral velocity being considered negligeable, with the neutral equation of motion consequently uncoupled from the ion velocity equation. In this work the effect of ion-neutral drag is included, and the resulting coupled system of equations is solved. The current density exchanged between the E- and F-regions is also calculated.Asociación Argentina de Geofísicos y Geodesta

Effects of alkaline and acid solutions on glass/epoxy composites

Composite structures can be exposed to a range of corrosive environments during their in-service life, which causes degradation in terms of material properties. The effect of alkaline and acid solutions on the GRP mechanical properties can be found in open literature, but the studies presented are not sufficient to establish a full knowledge of this subject. In this paper the flexural properties and the impact strength of a glass fibre/epoxy composite after immersion in hydrochloric acid (HCl) and sodium hydroxide (NaOH) were analysed. Independently of the solution, the flexural strength and the flexural modulus decrease with the exposure time. However, alkaline solution promotes higher decrease of the flexural properties than the acid solution. The same tendency was observed for impact strength

Preparation and Characterization of a-SiC:H Absorber Layer for Semi-transparent Solar Cells

AbstractThis paper reports on device-quality silicon-carbon alloy (a-SiC:H) application as an absorber material in semi-transparent solar cells. Films with an optical bandgap ranging from 2 to 2.3 eV were prepared by plasma enhanced chemical vapour deposition (PECVD). The n-i-p structures with undoped SiC:H layers deposited under the same experimental conditions were also fabricated and characterized. The optimized devices showed forward current-voltage characteristics with a diode ideality factor in the range from 1.4 to 1.8, and an open circuit voltage up to 0.92 V. The density of deep defect states in a SiC:H was estimated from the transient current measurements and correlated with the optical bandgap

The Importance of Multiheme Cytochromes

Publisher Copyright: Copyright: © 2022 The Author(s)Extracellular electron transfer is a key metabolic process of many organisms that enables them to exchange electrons with extracellular electron donors/acceptors. The discovery of organisms with these abilities and the understanding of their electron transfer processes has become a priority for the scientific and industrial community, given the growing interest on the use of these organisms in sustainable biotechnological processes. For example, in bioelectrochemical systems electrochemical active organisms can exchange electrons with an electrode, allowing the production of energy and added-value compounds, among other processes. In these systems, electrochemical active organisms exchange electrons with an electrode through direct or indirect mechanisms, using, in most cases, multiheme cytochromes. In numerous electroactive organisms, these proteins form a conductive pathway that allows electrons produced from cellular metabolism to be transferred across the cell surface for the reduction of an electrode, or vice-versa. Here, the mechanisms by which the most promising electroactive bacteria perform extracellular electron transfer will be reviewed, emphasizing the proteins involved in these pathways. The ability of some of the organisms to perform bidirectional electron transfer and the pathways used will also be highlighted.publishersversionpublishe