摘要:

AbstractProtein gels formed by crosslinking bovine serum albumin and horseradish peroxidase with glutaraldehyde were used to measure effects on peroxidase activity of 400‐MHz (CW) radiofrequency radiation (RFR) at an average specific absorption rate (SAR) of 1.45 W/ kg. The enzyme activity was measured by luminol chemiluminescence recorded on photographic film after hydrogen peroxide activation. Activity was measured during RFR exposure of gels or after exposure of gels polymerized in the RFR field. During exposure, a significant (P<.05) reversible increase occurred in overall mean peroxidase activity of gels activated with 0.88 M H2O2but not in those activated with 8.8 M H2O2. Gels containing solubilized luminol and formed in the field showed no overall mean increase in peroxidase activity, but did display a highly significant (P<.001) alteration in the distribution of local activities when compared to unexposed gels. These results are apparently due to changes in the rate of diffusion (concentration equilibration) of hydrogen peroxide in the ge

ISSN:0197-8462    

DOI:10.1002/bem.2250040302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe effects of various psychoactive drugs were studied in rats exposed for 45 min in a circularly polarized, pulsed microwave field (2450 MHz; SAR 0.6 W/kg; 2‐μs pulses, 500 pps). Apomorphine‐induced hypothermia and stereotypy were enhanced by irradiation. Amphetamine‐induced hyperthermia was attenuated while stereotypy was unaffected. Morphine‐induced catalepsy and lethality were enhanced by irradiation at certain dosages of the drug. Since these drugs have different modes of action on central neural mechanisms and the effects of microwaves depend on the particular drug studied, these results show the complex nature of the effect of microwave irradiation on brain f

ISSN:0197-8462    

DOI:10.1002/bem.2250040303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractRats partially deprived of food were trained individually to press a lever in the presence of a vertical, 60‐Hz electric field and not to press in its absence. Correct detections that occurred during brief, 3‐ or 4‐s trials occasionally produced a food pellet. The probability of detecting the field was found to increase as field strength increased. The threshold of detection, ie, the field strength required for detections at a probability of 0.5 after correction for errors, was generally between 4 and 10 kV/m. The range of field strengths between almost zero and almost 100% correctness of detection was approximately 8 kV/m. A logistic function provided a good description of the increase in the detection probability with increasing field strength. These performances occurred reliably in 19 rats, some of which were studied for 2 years. Control procedures showed that the behavior required that the rat be in the electric field; the behavior was not controlled by any of several potentially confounding vari

ISSN:0197-8462    

DOI:10.1002/bem.2250040304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractFive groups of pregnant Sprague‐Dawley rats were either sham exposed or were irradiated in a 27.12‐MHz radiofrequency (RF) field at 55 A/m and 300 V/m on gestation day 9. The absorbed power (approximately 11 W/kg) caused a relatively rapid increase in the rat's colonic temperature. Rats in group I were sham irradiated for 2.5 h at 0 A/m, 0 V/m. In group II RF irradiation was terminated after the rat's colonic temperature reached 41.0 °C. In group III the 41.0‐ °C temperature was maintained an additional 15 min by varying the field strength. At both temperatures the teratogenic and embryotoxic effects of the RF‐induced hyperthermia increased as the exposure duration increased, but the increase was especially noticeable at 42.0 °C. The results indicate that the teratogenic and embryotoxic effects of RF‐induced hyperthermia are related to both the temperature of the dam during exposure and the length of time the dam's temperature rema

ISSN:0197-8462    

DOI:10.1002/bem.2250040305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractTissue‐substitute models consisting of layers of synthetic, electrically equivalent subcutaneous fat, muscle, and bone shaped in conformation with the normal anatomy are used for rapid determination of distribution of temperature and specific absorption rate throughout the tissues when exposed to electromagnetic radiation. The surfaces of the bisected models are approximated during a short exposure period, then separated and scanned with a thermograph. A method was developed to eliminate the electrical discontinuity at the bisected surfaces while allowing separation and subsequent thermographic scanning. A thin layer of silk screen wetted with propylene glycol saturated with sodium chloride was used at the fat interface and a 0.9% sodium chloride solution was used to wet the screen at the muscle interface to eliminate electrical discontinuity during exposure to 27.12‐MHz diathermy. Tests showed that in the presence of an electrical discontinuity the heating pattern was grossly distorted. With the method used, the electrical discontinuity is minimized and the subsequent thermographic scanning reveals that the heating pattern is equivalent to that of an intact mo

ISSN:0197-8462    

DOI:10.1002/bem.2250040306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractA maximum of six live mice, mouse cadavers, prolate spheroids molded from muscle‐equivalent tissue, or saline‐filled culture flasks, were exposed to continuous wave radiation in a TEM cell at frequencies between 200 and 400 MHz. Whole‐body average specific absorption rate (SAR) was determined from power meter measurements of incident, reflected, and transmitted powers. The SARs for both live mice and cadavers were approximately twice that for the prolate spheroid models, and when housed in Plexiglas restraining cages, about 2 1/2 times greater. An error multiplying factor is identified, that quantitatively expresses how SAR data obtained by the three ‐power‐meter method becomes progressively more noisy as the irradiation frequency is lowered or as the TEM cell cross section is

ISSN:0197-8462    

DOI:10.1002/bem.2250040307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractSignificant inhibition of allogeneic cytotoxicity of the target cell MPC‐11 by the murine cytotoxic T‐lymphocyte line CTLL‐1 was observed when the 4‐h cytotoxicity assay was conducted in the presence of a 450‐MHz field sinusoidally amplitude‐modulated at 60 Hz. Exposure of the effector cells to the field prior to adding them to the target cells in the cytolytic assay resulted in a similar inhibition, suggesting a direct interaction of the field with the cytolytic T lymphocyte. The inhibition was preferentially expressed during the early allogeneic recognition phase. Fieldexposed cytolytic cells recovered their full cytolytic capacity in 12.5 h. A differential susceptibility was observed with modulation frequencies from 0 to 100 Hz. Peak suppression occurred at 60 Hz modulation, with progressively smaller effects at 40, 16, and 3 Hz. The unmodulated carrier wave did not affect the cytotoxicity. Effects with 80‐ and 100‐Hz modulation were smaller than at 60 Hz. These results demonstrate an inhibitory but recoverable effect by certain amplitude modulations of weak nonionizing radiation upon the cell‐mediated cytolyti

ISSN:0197-8462    

DOI:10.1002/bem.2250040308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0197-8462    

DOI:10.1002/bem.2250040309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0197-8462    

DOI:10.1002/bem.2250040310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0197-8462    

DOI:10.1002/bem.2250040301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY