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Electromagnetic Radiation

Andrei Ghila, Stephen Steciw, B Gino Fallone, Satyapal Rathee
PURPOSE: Integrating a linac with a magnetic resonance imager (MRI) will revolutionize the accuracy of external beam radiation treatments. Irradiating in the presence of a strong magnetic field, however, will modify the dose distribution. These dose modifications have been investigated previously, mainly using Monte Carlo simulations. The purpose of this work is to experimentally verify the use of the EGSnrc Monte Carlo (MC) package for calculating percent depth doses (PDDs) in a homogeneous phantom, in the presence of a realistic parallel magnetic field...
June 19, 2017: Medical Physics
Qian Zhang, Xiang Wan, Shuo Liu, Jia Yuan Yin, Lei Zhang, Tie Jun Cui
We present a fully digital procedure of designing reflective coding metasurfaces to shape reflected electromagnetic waves. The design procedure is completely automatic, controlled by a personal computer. In details, the macro coding units of metasurface are automatically divided into several types (e.g. two types for 1-bit coding, four types for 2-bit coding, etc.), and each type of the macro coding units is formed by discretely random arrangement of micro coding units. By combining an optimization algorithm and commercial electromagnetic software, the digital patterns of the macro coding units are optimized to possess constant phase difference for the reflected waves...
June 15, 2017: Scientific Reports
Yasiel Cabrera, Sara M Rupich, Ryan Shaw, Benoy Anand, Manuel de Anda Villa, Rezwanur Rahman, Aaron Dangerfield, Yuri N Gartstein, Anton V Malko, Yves J Chabal
Integration of colloidal nanocrystal quantum dots (NQDs) with strongly absorbing semiconductors offers the possibility of developing optoelectronic and photonic devices with new functionalities. We examine the process of energy transfer (ET) from photoactive CdSe/ZnS core/shell NQDs into lead-halide perovskite polycrystalline films as a function of distance from the perovskite surface using time-resolved photoluminescence (TRPL) spectroscopy. We demonstrate near-field electromagnetic coupling between vastly dissimilar excitation in two materials that can reach an efficiency of 99% at room temperature...
June 14, 2017: Nanoscale
Stefano Parodi, Franco Domenico Merlo, Emanuele Stagnaro
PURPOSE: Several investigations have analysed the association between coffee intake and risk of cancer. Contradictory results were reported by the studies conducted in non-Hodgkin's lymphomas (NHL) few of which report results according to main NHL subgroups. The present study is aimed at evaluating the association between coffee consumption and the risk of NHL by analysing data from a large Italian multicentre case-control study that included 1,418 interviewed cases (1,301 B cell and 117 T cell NHL), diagnosed between 1990 and 1993, and 1,774 population healthy controls...
June 13, 2017: Cancer Causes & Control: CCC
A Embriaco, V E Bellinzona, A Fontana, A Rotondi
PURPOSE: The accurate and fast calculation of the dose in proton radiation therapy is an essential ingredient for successful treatments. We propose a novel approach with a minimal number of parameters. METHODS: The approach is based on the exact calculation of the electromagnetic part of the interaction, namely the Molière theory of the multiple Coulomb scattering for the transversal 1D projection and the Bethe-Bloch formula for the longitudinal stopping power profile, including a gaussian energy straggling...
June 2017: Physica Medica: PM
Karlen Hovnanyan, Vitaly Kalantaryan, Armen Trchounian
Low intensity electromagnetic field of extremely high frequency has inhibitory and stimulatory effects on bacteria, including Enterococcus hirae. It was shown that the low intensity (the incident power density of 0.06 mW cm(-2) ) electromagnetic field at the frequences of 51.8 GHz and 53 GHz inhibited E. hirae ATCC9790 bacterial growth rate; a stronger effect was observed with 53 GHz, regardless of exposure duration (0.5 h, 1 h or 2 h). Scanning electron microscopy analysis of these effects has been done; the cells were of spherical shape...
June 13, 2017: Letters in Applied Microbiology
Yingzhi Jiao, Fan Wu, Kun Zhang, Mengxiao Sun, Aming Xie, Wei Dong
Ribbon-like nano-structures possess high aspect ratio, and thus have great potential in the development of high-performance microwaves absoption (MA) materials that can effectively eliminate adverse electromagnetic radiation. However, this nano-structures have been scarcely constructed in the field of MA, just because of the lack of efficient synthetic route. Herein, we developed an efficient method to successfully construct PPy nano-ribbons using the self-assembly aggregates of a racemic surfactant as the seeds...
June 8, 2017: Nanotechnology
Kota Ito, Kazutaka Nishikawa, Atsushi Miura, Hiroshi Toshiyoshi, Hideo Iizuka
Dynamic control of electromagnetic heat transfer without changing mechanical configuration opens possibilities in intelligent thermal management in nanoscale systems. We confirmed by experiment that the radiative heat transfer is dynamically modulated beyond the blackbody limit. The near-field electromagnetic heat exchange mediated by phonon-polariton is controlled by the metal-insulator transition of tungsten-doped vanadium dioxide. The functionalized heat flux is transferred over an area of 1.6 cm(2) across a 370 nm gap, which is maintained by the microfabricated spacers and applied pressure...
June 12, 2017: Nano Letters
Małgorzata Lewicka, Gabriela Henrykowska, Magdalena Zawadzka, Maciej Rutkowski, Krzysztof Pacholski, Andrzej Buczyński
OBJECTIVES: The increasing number of devices emitting electromagnetic radiation (EMR) in people's everyday life attracted the attention of researchers because of possible adverse effects of this factor on living organisms. One of the EMR effect may be peroxidation of lipid membranes formed as a result of free radical process. The article presents the results of in vitro studies aimed at identifying changes in malondialdehyde (MDA) concentration - a marker of lipid peroxidation and antioxidant role of vitamin A during the exposure of blood platelets to electromagnetic radiation generated by liquid-crystal-display (LCD) monitors...
May 30, 2017: International Journal of Occupational Medicine and Environmental Health
V Vaquero, A Jungclaus, P Doornenbal, K Wimmer, A Gargano, J A Tostevin, S Chen, E Nácher, E Sahin, Y Shiga, D Steppenbeck, R Taniuchi, Z Y Xu, T Ando, H Baba, F L Bello Garrote, S Franchoo, K Hadynska-Klek, A Kusoglu, J Liu, T Lokotko, S Momiyama, T Motobayashi, S Nagamine, N Nakatsuka, M Niikura, R Orlandi, T Saito, H Sakurai, P A Söderström, G M Tveten, Zs Vajta, M Yalcinkaya
Excited states in the nucleus ^{133}Sn, with one neutron outside the double magic ^{132}Sn core, were populated following one-neutron knockout from a ^{134}Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the γ rays emitted in the decay of the known neutron single-particle states in ^{133}Sn additional γ strength in the energy range 3.5-5.5 MeV was observed for the first time. Since the neutron-separation energy of ^{133}Sn is low, S_{n}=2.402(4)  MeV, this observation provides direct evidence for the radiative decay of neutron-unbound states in this nucleus...
May 19, 2017: Physical Review Letters
S M J Mortazavi, Z Mostafavi-Pour, M Daneshmand, F Zal, R Zare, M A Mosleh-Shirazi
BACKGROUND: Over the past few years, the rapid use of high frequency electromagnetic fields like mobile phones has raised global concerns about the negative health effects of its use. Adaptive response is the ability of a cell or tissue to better resist stress damage by prior exposure to a lesser amount of stress. This study aimed to assess whether radiofrequency radiation can induce adaptive response by changing the antioxidant balance. MATERIALS AND METHODS: In order to assess RF-induced adaptive response in tissues, we evaluated the level of GSH and the activity of GR in liver...
June 2017: Journal of Biomedical Physics & Engineering
Andraž Kocjan, Manca Logar, Zhijian Shen
Conventional sintering is a time- and energy-consuming process used for the densification of consolidated particles facilitated by atomic diffusion at high temperatures. Nanoparticles, with their increased surface free energy, can promote sintering; however, size reduction also promotes agglomeration, so hampering particle packing and complete densification. Here we show how the ordered agglomeration of zirconia primary crystallites into secondary particle assemblies ensures their homogeneous packing, while also preserving the high surface energy to higher temperatures, increasing the sintering activity...
May 31, 2017: Scientific Reports
Çiğdem Gökçek-Saraç, Hakan Er, Ceren Kencebay Manas, Deniz Kantar Gok, Şükrü Özen, Narin Derin
PURPOSE: To demonstrate the molecular effects of acute and chronic exposure to both 900 and 2100 MHz radiofrequency electromagnetic radiation (RF-EMR) on the hippocampal level/activity of some of the enzymes - including PKA, CaMKIIα, CREB, and p44/42 MAPK - from N-methyl-D-aspartate receptor (NMDAR)-related signaling pathways. MATERIALS AND METHODS: Rats were divided into the following groups: sham rats, and rats exposed to 900 and 2100 MHz RF-EMR for 2 h/day for acute (1 week) or chronic (10 weeks), respectively...
June 20, 2017: International Journal of Radiation Biology
Pier Luigi Gentili, Maria Sole Giubila, Raimondo Germani, Aldo Romani, Andrea Nicoziani, Anna Spalletti, B Mark Heron
Neuromorphic engineering promises to have a revolutionary impact in our societies. A strategy to develop artificial neurons (ANs) is to use oscillatory and excitable chemical systems. Herein, we use UV and visible radiation as both excitatory and inhibitory signals for the communication among oscillatory reactions, such as the Belousov-Zhabotinsky and the chemiluminescent Orban transformations, and photo-excitable photochromic and fluorescent species. We present the experimental results and the simulations regarding pairs of ANs communicating by either one or two optical signals, and triads of ANs arranged in both feed-forward and recurrent networks...
May 31, 2017: Angewandte Chemie
Dimitris J Panagopoulos, Alfonso Balmori
Atmospheric electrical discharges during thunderstorms, and the related electromagnetic fields (EMFs)/waves called sferics, can be sensed by humans at long distances through a variety of symptoms, mainly headache, fatigue, etc. Up to today there is no explanation for this association. Sferics consist of partially polarized electromagnetic pulses with an oscillating carrier signal in the very low frequency (VLF) band and a pulse repetition frequency in the extremely low frequency (ELF) band. Their ELF intensity may reach ~5mV/m at global ranges, and ~0...
December 1, 2017: Science of the Total Environment
Jorge Berger
The standard operation of a dc SQUID leads to oscillatory electric fields that emit electromagnetic radiation. We estimate the effect that this radiation could have on the measured sample. A stationary SQUID could be advantageous if the oscillation contribution to back action on the measured sample has to be avoided. We study a superconducting loop that encloses a magnetic flux, connected to a superconducting and to a normal electrode, when a fixed electric current between the electrodes flows across the loop...
May 30, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Zeinab Akbarnejad, Hossein Eskandary, Luciana Dini, Cristian Vergallo, Seyed Noureddin Nematollahi-Mahani, Alireza Farsinejad, Maryam Fekri Soofi Abadi, Meysam Ahmadi
Glioblastoma multiforme (GBM) is the most malignant brain cancer that causes high mortality in humans. It responds poorly to the most common cancer treatments, such as surgery, chemo- and radiation therapy. Temozolomide (TMZ) is an alkylating agent that has been widely used to treat GBM; resistance to this drug is often found. One unexplored possibility for overcoming this resistance is a treatment based on concomitant exposure to electromagnetic fields (EMF) and TMZ. Indeed, many evidences show that EMF affects cancer cells and drug performance...
May 24, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Valentina Amore, Malva I M Hernández, Luis M Carrascal, Jorge M Lobo
The insect exoskeleton is a multifunctional coat with a continuum of mechanical and structural properties constituting the barrier between electromagnetic waves and the internal body parts. This paper examines the ability of beetle exoskeleton to regulate internal body temperature considering its thermal permeability or isolation to simulated solar irradiance and infrared radiation. Seven Neotropical species of dung beetles (Coleoptera, Scarabaeinae) differing in colour, surface sculptures, size, sexual dimorphism, period of activity, guild category and altitudinal distribution were studied...
2017: PeerJ
Mark R Bowling, Craig Brown, Carlos J Anciano
BACKGROUND: Navigational bronchoscopy and other imaging modalities have improved the ability to evaluate pulmonary nodules/mass. Many of these lesions are located outside the bronchial airway and are difficult to access even with these devices. The Transbronchial Access Tool (Medtronic, Minneapolis, MN) allows the bronchoscopist to create a pathway from the bronchial airway, across the lung parenchyma, and into the target lesion. We are reporting the feasibility and safety of this new device...
May 17, 2017: Annals of Thoracic Surgery
Alice Chang
Tumor-treating fields (TTFields) are a new technology used for cancer treatment consisting of battery-powered, insulated electromagnetic transducers that are placed on the scalp. This wearable, adhesive device is a certified physician-prescribed therapy for patients with glioblastoma multiforme, a type of primary brain cancer. TTFields are being used concomitantly with temozolomide (Temodar®) in patients with newly diagnosed glioblastoma and as a monotherapy in patients with recurrent glioblastoma after radiation therapy and chemotherapy...
June 1, 2017: Clinical Journal of Oncology Nursing
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