Role of blood flow on RF exposure induced skin temperature elevations in rabbit ears

Jia, Fu; Ushiyama, Akira; Masuda, Hiroshi; Lawlor, George F.; Ohkubo, Chiyoji

doi:10.1002/bem.20286

Cited by 7 publications

(2 citation statements)

References 23 publications

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“…Heat generation in exposed tissue [Jia et al, ] and organs [Kojima et al, ] was observed following the exposure to a high‐intensity RF signal, which may affect physiological functions in animals. Indeed, whole‐body [Jauchem and Frei, ] and local [Masuda et al, ] exposure to a high‐intensity RF signal reportedly increased the body temperature in animals.…”

Section: Introductionmentioning

confidence: 99%

Effect of Exposure to a Radiofrequency Electromagnetic Field on Body Temperature in Anesthetized and Non‐Anesthetized Rats

Kim

Lee

Choi

et al. 2019

Bioelectromagnetics

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Exposure to a radiofrequency (RF) signal at a specific absorption rate (SAR) of 4 W/kg can increase the body temperature by more than 1°C. In this study, we investigated the effect of anesthesia on the body temperature of rats after exposure to an RF electromagnetic field at 4 W/kg SAR. We also evaluated the influence of body mass on rats' body temperature. Rats weighing 225 and 339 g were divided into sham-and RF-exposure groups. Each of the resulting four groups was subdivided into anesthetized and non-anesthetized groups. The free-moving rats in the four RF-exposure groups were subjected to a 915 MHz RF identification signal at 4 W/kg whole-body SAR for 8 h. The rectal temperature was measured at 1-h intervals during RF exposure using a small-animal temperature probe. The body temperatures of non-anesthetized, mobile 225 and 339 g rats were not significantly affected by exposure to an RF signal. However, the body temperatures of anesthetized 225 and 339 g rats increased by 1.9°C and 3.3°C from baseline at 5 and 6 h of RF exposure, respectively. Three of the five 339 g anesthetized and exposed rats died after 6 h of RF exposure. Thus, anesthesia and body mass influenced RF exposure-induced changes in the body temperature of rats.

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Section: Introductionmentioning

confidence: 99%

Effect of Exposure to a Radiofrequency Electromagnetic Field on Body Temperature in Anesthetized and Non‐Anesthetized Rats

Kim

Lee

Choi

et al. 2019

Bioelectromagnetics

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“…High-intensity exposure to radiofrequency electromagnetic fields (RF) generates heat in exposed tissue (3,15) and organs (17,43). Thus this type of exposure has the capacity to affect physiological functions in mammals via heat generation.…”

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confidence: 99%

Local exposure of the rat cortex to radiofrequency electromagnetic fields increases local cerebral blood flow along with temperature

Masuda

Hirata

Kawai

et al. 2011

Journal of Applied Physiology

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Few studies have shown that local exposure to radiofrequency electromagnetic fields (RF) induces intensity-dependent physiological changes, especially in the brain. The aim of the present study was to detect reproducible responses to local RF exposure in the parietal cortex of anesthetized rats and to determine their dependence on RF intensity. The target cortex tissue was locally exposed to 2-GHz RF using a figure-eight loop antenna within a range of averaged specific absorption rates (10.5, 40.3, 130, and 263 W/kg averaged over 4.04 mg) in the target area. Local cerebral blood flow (CBF) and temperatures in three regions (target area, rectum, and calf hypodermis) were measured using optical fiber blood flow meters and thermometers during RF exposure. All parameters except for the calf hypodermis temperature increased significantly in exposed animals compared with sham-exposed ones during 18-min exposures. Dependence of parameter values on exposure intensity was analyzed using linear regression models. The elevation of local CBF was correlated with temperature rise in both target and rectum at the end of RF exposure. However, the local CBF elevation seemed to be elevated by the rise in target temperature, but not by that of the rectal temperature, in the early part of RF exposure or at low-intensity RF exposure. These findings suggest that local RF exposure of the rat cortex drives a regulation of CBF accompanied by a local temperature rise, and our findings may be helpful for discussing physiological changes in the local cortex region, which is locally exposed to RF.

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Fusible and Radiopaque Microspheres for Embolization

Li,

Xu,

Wang

et al. 2024

Advanced Materials

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In this work, fusible microspheres loaded with radiopaque agents as an embolic agent for transcatheter arterial embolization (TAE) are developed. A poly(ethylene glycol) (PEG) and poly(ε‐caprolactone) (PCL) multi‐block copolymer basing polyurethane (PCEU) is synthesized and fabricated into blank microspheres (BMs). The microspheres are elastic in compression test. A clinical contrast agent lipiodol is encapsulated in the microspheres to receive fusible radiopaque microspheres (FRMs). The sizes of FRMs are uniform and range from 142.2 to 343.1 µm. The encapsulated lipiodol acts as the plasticizer to reduce the melting temperature point (Tm) of PECU microspheres, thus, leading to the fusion of microspheres to exhibit efficient embolization in vivo. The performance of FRMs is carried out on a rabbit ear embolization model. Serious ischemic necrosis is observed and the radiopacity of FRMs sustains much longer time than that of commercial contrast agent Loversol in vivo. The fusible and radiopaque microsphere is promising to be developed as an exciting embolic agent.

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Role of blood flow on RF exposure induced skin temperature elevations in rabbit ears

Cited by 7 publications

References 23 publications

Effect of Exposure to a Radiofrequency Electromagnetic Field on Body Temperature in Anesthetized and Non‐Anesthetized Rats

Effect of Exposure to a Radiofrequency Electromagnetic Field on Body Temperature in Anesthetized and Non‐Anesthetized Rats

Local exposure of the rat cortex to radiofrequency electromagnetic fields increases local cerebral blood flow along with temperature

Fusible and Radiopaque Microspheres for Embolization

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