354 research outputs found

    Suggestions for Radiation Oncologists during the COVID-19 Pandemic

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    SARS-CoV-2 pandemic and COVID-19 diffusion have recently become an international public health emergency. Cancer patients, as a frail population, are particularly exposed to the risk related to infections. The clinical decision-making process and the organizational workflow of radiotherapy department should be revised in the light of the critical situation. We herein provide practical suggestions derived from the available literature and discussed during an online session held within the e-learning educational program of the European School of Oncology on March 31st 2020

    GERMINATION OF RESTING STAGES OF DIATOMS AND DINOFLAGELLATES IN MARINE SEDIMENTS FROM TWO UPWELLING AREAS OF CHILE

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    Con el fin de evaluar la potencial germinación de los estados de resistencia de las diatomeas y dinofiagelados preservados en sedimentos superficiales, se cultivaron bajo condiciones de laboratorio sedimentos de las bahías de Mejillones (23° S) y Concepción (36° S), Chile: Ciclo L:0 12:12 h, intensidad de luz 140 umol m²s_1, temperatura ambiente y 35,4 unidades de salinidad. Las principales especies de diatomeas presentes en los sedimentos fueron Skeletonema japonicum y esporas de Chaetoceros. Los quistes de dinofiagelados estuvieron representados por Diplopsalis, Scrippsiella, Woloszynskia y las especies Protoperidinium avellanum y P. leonis. Después de 20 días de cultivo, se registró germinación y crecimiento de S. japonicum y de varias especies de Chaetoceros, sin embargo su abundancia fue baja. Las diatomeas con crecimiento abundante fueron Stauroneis legleri, Pseudostaurosira trainorii, Pseudostaurosira sp.l, Pseudostaurosira sp. 2 y Navícula pseudoreinhardtii. El dinoflagelado Woloszynskia sp. también germinó y creció abundantemente. Este trabajo incluye una breve descripción de las especies cultivadas y algunos aspectos de su ecología. Se discuten las posibles causas de la pobre germinación de las diatomeas planctónicas, siendo la baja concentración de oxígeno disuelto en las aguas de fondo uno de los principales factores que presumiblemente afectaron la sobrevivencia de las esporas de resistencia. With the aim to assess germination of diatom and dinofiagellates resting spores we cultured under laboratory conditions surface sediments collected in the Mejillones Bay (23° S) and off Concepción (36° S), Chile. These sediments were cultured in the laboratory with a 12:12 h L/D cycle, light intensity of 140 umol m² s"¹, at room temperature, and with a salinity of 35.4 units. The main diatom species in the sediments were Skeletonema japonicum and Chaetoceros spores. Dinofiagellate cysts were represented by the genera Diplopsalis, Scrippsiella, and Woloszynskia and the species Protoperidinium avellanum and P. leonis. After 20 days of culturing, germination and growth was recorded for S. japonicum and several of the Chaetoceros species, although their abundance was low. The diatoms with abundant growth were Stauroneis legleri, Pseudostaurosira trainorii, Pseudostaurosira sp.l, Pseudostaurosira sp. 2, and Navícula pseudoreinhardtii. The dinofiagellate Woloszynskia sp. also germinated and grew abundantly in the culture. This study includes a brief description of the cultured species and some aspects of their ecology. In addition, we discuss the possible causes for low levels of germination in planktonic diatoms, finding low dissolved oxygen concentrations in the bottom waters to be one of the main factors that presumably affected the survival of resting spores in the sediment

    The local intrinsic curvature of wavefronts allows to detect optical vortices

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    We describe a method for effectively distinguishing the radiation endowed with optical angular momentum, also known as optical vortex, from ordinary light. We show that by detecting the inversion of the transverse intrinsic curvature sign (ITICS) an optical vortex can be locally recognized. The method is effective under conditions of huge importance for the exploitation of optical vortices, such as the far field of the source and access to a small fraction of the wavefront only. The validity of the method has been verified with table-top experiments with visible light, and the results show that a measurement performed over a transverse distance smaller than 4% of the beam diameter distinguishes a vortex from a Gaussian beam with a significance of 93.4%. New perspectives are considered for the characterization of vortices, with potential impact on the detection of extra-terrestrial radiation as well as on broadcast communication techniques

    EnAPlug – An Environmental Awareness Plug to Test Energy Management Solutions for Households

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    The present paper presents a new kind of Smart Plug that covers the needs of power systems R&D centers. EnAPlug, described in this paper, enables the monitor and control of loads, as a normal Smart Plug. However, it has a great benefit in comparison with a normal Smart Plug, the EnAPlug allows the integration of a variety of sensors so the user can understand the load and the surrounding environment (using a set of sensors that better fit the load). The sensors are installed in the load itself, and must have a clear fit to the load. The paper presents a demonstration of an EnAPlug used in a refrigerator for a demand response event participation, using the sensor capability to measure important values, such as, inside temperature.The present work has been developed under the EUREKA - ITEA2 Project M2MGrids (ITEA-13011), Project SIMOCE (ANI|P2020 17690), and has received funding from FEDER Funds through COMPETE program and from National Funds through FCT under the project UID/EEA/00760/2013 and SFRH/BD/109248/2015.info:eu-repo/semantics/publishedVersio

    Solving classification tasks by a receptron based on nonlinear optical speckle fields

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    Among several approaches to tackle the problem of energy consumption in modern computing systems, two solutions are currently investigated: one consists of artificial neural networks (ANNs) based on photonic technologies, the other is a different paradigm compared to ANNs and it is based on random networks of nonlinear nanoscale junctions resulting from the assembling of nanoparticles or nanowires as substrates for neuromorphic computing. These networks show the presence of emergent complexity and collective phenomena in analogy with biological neural networks characterized by self-organization, redundancy, non-linearity. Starting from this background, we propose and formalize a generalization of the perceptron model to describe a classification device based on a network of interacting units where the input weights are nonlinearly dependent. We show that this model, called "receptron", provides substantial advantages compared to the perceptron as, for example, the solution of non-linearly separable Boolean functions with a single device. The receptron model is used as a starting point for the implementation of an all-optical device that exploits the non-linearity of optical speckle fields produced by a solid scatterer. By encoding these speckle fields we generated a large variety of target Boolean functions without the need for time-consuming machine learning algorithms. We demonstrate that by properly setting the model parameters, different classes of functions with different multiplicity can be solved efficiently. The optical implementation of the receptron scheme opens the way for the fabrication of a completely new class of optical devices for neuromorphic data processing based on a very simple hardware

    A survey on fopid controllers for lfo damping in power systems using synchronous generators, facts devices and inverter-based power plants

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    In recent decades, various types of control techniques have been proposed for use in power systems. Among them, the use of a proportional–integral–derivative (PID) controller is widely recognized as an effective technique. The generalized type of this controller is the fractional-order PID (FOPID) controller. This type of controller provides a wider range of stability area due to the fractional orders of integrals and derivatives. These types of controllers have been significantly considered as a new approach in power engineering that can enhance the operation and stability of power systems. This paper represents a comprehensive overview of the FOPID controller and its applications in modern power systems for enhancing low-frequency oscillation (LFO) damping. In addition, the performance of this type of controller has been evaluated in a benchmark test system. It can be a driver for the development of FOPID controller applications in modern power systems. Investigation of different pieces of research shows that FOPID controllers, as robust controllers, can play an efficient role in modern power systems

    Single-shot measurement of phase and topological properties of orbital angular momentum radiation through asymmetric lateral coherence

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    We show a single-shot technique to measure topological and phase properties of radiation carrying orbital angular momentum. The single-shot method is effectively described as the one-dimensional case of a more general two-dimensional approach based on scanning interferometry (asymmetric lateral coherence). The validity of the method has been experimentally verified and the applicability to ultrarelativistic sources of hard x-rays has been discussed. The method is suitable to characterize phase and topological properties of x-ray sources by using simple apertures

    Electron Beam Size Measurements Using the Heterodyne Near Field Speckles at ALBA

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    Experiments using the heterodyne near field speckle method (HNFS) have been performed at ALBA to characterize the spatial coherence of the synchrotron radiation, with the ultimate goal of measuring both the horizontal and vertical electron beam sizes. The HNFS technique consists on the analysis of the interference between the radiation scattered by a colloidal suspension of nanoparticles and the synchrotron radiation, which in this case corresponds to the hard x-rays (12keV) produced by the in-vacuum undulator of the NCD-Sweet beamline. This paper describes the fundamentals of the technique, possible limitations, and shows the first experimental results changing the beam coupling of the storage ring

    Fine-needle cytology in the follow-up of breast carcinoma

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    The postoperative follow-up strategies for breast carcinoma (BC) utilize different procedures; the aim of this study was to investigate the role of fine-needle cytology (FNC) in the follow-up of BC patients. Two hundred sixty-six FNC samples from 190 BC patients have been reviewed. The target anatomical sites were 190 breast including 155 ipsilateral and 145 contralateral breast lesions and 76 extra-mammary nodules. Extra-mammary lesions included lymph nodes, thyroidal nodules, soft tissue lesions, (subcutaneous and sub-scars), salivary glands and deep located masses. Diagnostic distribution of the breast lesions was as follows: 51 positive, 15 indeterminate/suspicious, 119 negative and 5 inadequate. Positive cases included 43 ipsilateral and 8 contralateral BC, 9 BC in different quadrants from those of onset of the first BC. Sensitivity, specificity and accuracy have been 90, 91 and 90&, respectively. FNC, in a correct setting, is a reliable and effective method for the follow-up management of BC patients
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