نتایج جستجو برای: radiofrequency field

تعداد نتایج: 803430  

Journal: :Concepts in Magnetic Resonance Part A 2022

The equation of motion the density matrix an ensemble identical spin-1/2 nuclei subject to a rotating-frame radiofrequency field and Zeeman frequency offset is derived from Schrodinger shown be equivalent magnetization differential equations originally proposed by Bloch (excluding relaxation). quantum classical are then integrated.

Journal: :the journal of tehran university heart center 0
rezayat parvizi fariborz akbarzadeh

background: atrial fibrillation is a common arrhythmia in patients with rheumatic mitral and other valve diseases who are candidates for valve repair surgeries. conversion of rhythm to sinus has positive effects on quality of life and lower use of medications. the aim of this clinical study was to evaluate the effectiveness of the radiofrequency ablation maze iii procedure in the treatment of a...

Journal: :journal of biomedical physics and engineering 0
s. m. j. mortazavi professor of medical physics, medical physics department, school of medicine, shiraz university of medical sciences, shiraz, iran m. motamedifar associate professor of microbiology, department of bacteriology, school of medicine and shiraz hiv/aids research center (sharc), shiraz university of medical sciences, shiraz, iran a. r. mehdizadeh assistant professor of medical physics, medical physics department, school of medicine, shiraz university of medical sciences, shiraz, iran g. namdari student research committee, school of medicine, shiraz university of medical sciences, shiraz, iran m. taheri lecturer of microbiology, laboratory sciences department, school of allied medical sciences, shiraz university of medical sciences, shiraz, iran

background: pre-exposure to radiofrequency radiations of mobile phones would significantly increase the survival rate of exposed animals compared to those exposed to a lethal dose of gamma radiation alone. stimulation of the immune system is believed to be a key mechanism for the induction of this phenomenon, the so-called “adaptive response.” the immune system protects organisms against infect...

Journal: :anesthesiology and pain medicine 0
matthew david vanderhoek department of anesthesia and operative services, san antonio military health system, san antonio military medical center, san antonio, usa; department of anesthesia and operative services, san antonio military health system, san antonio military medical center, san antonio, 3551 roger brooke dr., fort sam houston, tx 78234, usa. tel: +1-2109168666, fax: +1-2102927986 hieu t hoang department of anesthesia and operative services, san antonio military health system, san antonio military medical center, san antonio, usa brandon goff department of orthopaedics and rehabilitation, san antonio military health system, san antonio military medical center, san antonio, usa

occipital neuralgia is a condition manifested by chronic occipital headaches and is thought to be caused by irritation or trauma to the greater occipital nerve (gon). treatment for occipital neuralgia includes medications, nerve blocks, and pulsed radiofrequency ablation (prfa). landmark-guided gon blocks are the mainstay in both the diagnosis and treatment of occipital neuralgia. ultrasound is...

Journal: :Occupational and environmental medicine 2009
J F Viel S Clerc C Barrera R Rymzhanova M Moissonnier M Hours E Cardis

OBJECTIVES Both the public perceptions, and most published epidemiologic studies, rely on the assumption that the distance of a particular residence from a base station or a broadcast transmitter is an appropriate surrogate for exposure to radiofrequency fields, although complex propagation characteristics affect the beams from antennas. The main goal of this study was to characterise the distr...

2012
Daniela Platano Costanza Burattini Pietro Mesirca Entelë Gavoçi Alessandra Paffi Francesca Apollonio Micaela Liberti Ferdinando Bersani Giorgio Aicardi

We are studying non-thermal effects of continuous wave (2 W/kg) and GSM-modulated (2 or 4 W/kg) 900 MHz radiofrequency (RF) electromagnetic field exposure on synaptic transmission and plasticity in rat perirhinal cortex slices. Preliminary results, still under elaboration, indicate that the exposure to both RF signals may cause small changes in synaptic plasticity in our experimental conditions.

2010
Lei Gao Cai-Yi Lu Shi-Wen Wang Qiao Xue Wei Yan Sheng-Hua Zhou Rui Chen Peng Liu Jin-Yue Zhai

Objective The purpose of this study was to compare remote magnetic catheter navigation with manual navigation for the ablation of atrioventricular nodal reentry tachycardia (AVNRT). Methods From November 2007 to November 2009, 30 consecutive patients with AVNRT received radiofrequency ablation in the Institute of Geriatric Cardiology. Of them, 14 were treated with remote magnetic navigation (RM...

Journal: :International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group 2018
Elżbieta Ewertowska Borja Mercadal Víctor Muñoz Antoni Ivorra Macarena Trujillo Enrique Berjano

BACKGROUND The thermal and electrical effects of pulsed radiofrequency (PRF) for pain relief can be controlled by modifying the characteristics of the RF pulses applied. Our goal was to evaluate the influence of such modifications on the thermal and electric performance in tissue. METHODS A computational model was developed to compare the temperature and electric field time courses in tissue ...

ژورنال: سنجش و ایمنی پرتو 2020

Background: The widespread use of cell phones has led to an increase in concern about the effect of radiofrequency radiation on the physiology of the human body. This study was conducted to determine the different reaction temperatures of different brain tissue in exposure to mobile radiofrequency waves. Method: This was an experimental study. The cowchr('39')s brain tissue was examined in a c...

Journal: :Physical chemistry chemical physics : PCCP 2013
C J Wedge Jason C S Lau Kelly-Anne Ferguson Stuart A Norman P J Hore Christiane R Timmel

The purported effects of weak magnetic fields on various biological systems from animal magnetoreception to human health have generated widespread interest and sparked much controversy in the past decade. To date the only well established mechanism by which the rates and yields of chemical reactions are known to be influenced by magnetic fields is the radical pair mechanism, based on the spin-d...

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