摘要:

AbstractIon exposure chambers that have been designed and tested for use in biological and behavioral research with small animals are described in this report. The chambers exhibit an acceptable degree of uniformity in ion concentration, current density, and electric field within the exposure area. Gaseous by‐products of corona discharge (O3and NO2) have been measured and found to be<.01 ppm and<.1 ppm, respectively. Filtered air is fed to the individual exposure chambers, and temperature and humidity are well controlled. Noise due to corona and the air delivery system has been measure

ISSN:0197-8462    

DOI:10.1002/bem.2250070102

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

年代:1986

数据来源: WILEY

摘要:

AbstractSeasonal patterns were seen in fetal growth and in abortion rate for families using electrically heated beds. These patterns could be attributed to the seasonal use of heated beds. The fact that such seasonal patterns were seen only in users, and not in nonusers, of electrically heated beds suggests that electrical bed heating may have a direct effect on fetal development. The effect could be due to excessive heat or to electromagnetic field exposure.

ISSN:0197-8462    

DOI:10.1002/bem.2250070103

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

年代:1986

数据来源: WILEY

摘要:

AbstractWe previously showed that quasirectangular, asymmetrical, pulsed electromagnetic (EM) fields of low frequency can induce increased transcription in Sciara salivary gland cells. A symmetrical sine wave with the same frequency as known biologically effective asymmetric signals was studied in the present investigations. The results demonstrated that signal shape was not a major factor in causing augmented transcription. The pattern of grain density in transcription autoradiograms, as well as the size classes of RNA responsive to EM fields, was the same irrespective of asymmetry or symmetry of the signal. Following short‐term exposure of the cells to either type of EM field, S values of new transcripts were consistent with those expected for processed and unprocessed messenger RN

ISSN:0197-8462    

DOI:10.1002/bem.2250070104

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe dielectric properties of the bovine brain grey and white matter in the frequency range from 20 kHz to 100 MHz were measured at different times following animal death. Changes in the dielectric parameters versus time are interpreted in terms of the reduction of the cell volume fraction that results from either cell disintegration or cell size reduction. Good agreement between the computer fitted parameters and the values calculated from the Maxwell‐Wagner model of the static dielectric constants was found. At frequencies above 1 MHz the changes of the dielectric properties are less pronounced, confirming earlier observations made by other investigators for different specie

ISSN:0197-8462    

DOI:10.1002/bem.2250070105

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

年代:1986

数据来源: WILEY

摘要:

AbstractAdult male Long‐Evans rats were intermittently exposed to 2450 MHz CW microwaves at an average power density of 0.5 mW/cm2for 90 days. The resulting SAR was 0.14 W/kg (range 0.11 to 0.18 W/kg). The animals were exposed 7 h/day, 7 days/wk, for a total of 630 h in a monopole‐above‐ground radiation chamber while housed in Plexiglas holding cages. Daily measures of body mass and food and water intake indicated no statistically significant effects of microwave exposure. Monthly assessment of reactivity to electric footshock, levels of cholinesterase and sulfhydryl groups in blood, and 17‐ketosteroids in urine revealed no reliable differences between 14 sham‐exposed and 14 microwave‐exposed rats. After the 90 days of exposure, seven rats, randomly chosen from each group, were assessed for open‐field behavior, shuttlebox performance, and schedule‐controlled (IRT schedule) lever pressing for food pellets. Statistically significant differences between microwave‐exposed and sham‐exposed rats were observed in shuttlebox performances and lever pressing. Post mortem measures of mass of several organs and microscopic examination of adrenal tissue revealed no differences between the tw

ISSN:0197-8462    

DOI:10.1002/bem.2250070106

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

年代:1986

数据来源: WILEY

摘要:

AbstractRats exposed to microwaves prenatally (2,450 MHz, 10 mW/cm2, 3 h/day, days 5–20 of gestation) or perinatally (same as above plus days 2–20 postnatally) were examined by a neurobehavioral test battery on postnatal days 30 and 100. Body mass, locomotor activity, startle to acoustic and air‐puff stimuli, fore‐ and hindlimb grip strength, negative geotaxis, reaction to thermal stimulation, and swimming endurance were assessed. The prenatally and the perinatally exposed rats (male and female) weighed more than sham‐exposed rats at 30, but not at 100, days of age. In addition, the perinatally exposed animals had less swimming endurance at 30, but not at 100, days of age relative to sham‐exposed rats. For the other measures, only the air‐puff startle response was altered and was limited to the prenatally exposed female pups; ie, at postnatal day 30, the startle response was increased in magnitude, and at postnatal day 100, the response was decreased. No other reliable effects were observed. In a second experiment, rats treated as described above were examined for alterations in body mass, locomotor activity, reaction to air‐puff stimuli, reaction to thermal stimulation, and swimming endurance at postnatal days 30–36. Again, perinatally exposed rats were larger in body mass and had less swimming endurance compared with sham‐exposed rats. The latency to the air‐puff startle response was longer in female pups exposed prenatally. These data indicate that altered endurance and gross motor activity result from perinatal exposure to

ISSN:0197-8462    

DOI:10.1002/bem.2250070107

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe relative permittivity and conductivity of rabbit eye lens were measured in the frequency domain between 2 and 18 GHz at temperatures of 37 and 20°C. An analysis of the data suggested that a significant proportion of the bulk water in nuclear and cortical lens tissue may behave differently to pure water. In addition, the Maxwell‐Fricke mixture theory was used to estimate the amount of hydrated water that relaxes far below 1 G

ISSN:0197-8462    

DOI:10.1002/bem.2250070108

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

年代:1986

数据来源: WILEY

摘要:

AbstractWe discuss initial magnetic field strength measurements made around radiofrequency (RF) induction heaters. These measurements were made with a monitor developed for the National Institute for Occupational Safety and Health (NIOSH) by the National Bureau of Standards (NBS). The monitor has a dynamic range of .01 to 10,000 A2/m2, a frequency range of 300 kHz to 100 MHz, an isotropic response (± .3 dB) with three mutally orthogonal loop antennas that have the ability to measure and display each of three orthogonal magnetic field components, a high probe burnout protection level of 20,000 A2/m2, and an accuracy of ± 1.0 dB at 13 calibration frequencies. The portable survey monitor was used to measure the magnetic field strengths in the vicinity of 16 RF induction heaters. Typically these induction heaters are operated continuously for several hours. The maximum field strengths (without duty factor correction) ranged from 15 to 4,500 A2/m2and were measured 5 to 51 cm from the loop applicators of the induction heaters. At locations commonly occupied by workers (ie, approximately 30 to 76 cm from heaters), the fields ranged from .01 to 300 A2/m2(without duty factor correction

ISSN:0197-8462    

DOI:10.1002/bem.2250070109

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

年代:1986

数据来源: WILEY

摘要:

AbstractFemale CD‐1 mice immunized against the bacteriumStreptococcus pneumoniaetype III were exposed to 9‐GHz pulsed microwaves (pulse repetition rate 970‐1,000, pulse width 1.0 μs, peak power 1 W/cm2) at an average incident power density of 1 mW/cm2(calculated SAR = 0.47 W/kg) for 2 h per day for 5 days. Circulating antibody titers for the microwave‐exposed animals were not significantly different from those of the shamirradiated animals, and there were no differences in any of the hematological parameters analyzed, indicating that 9‐GHz pulsed microwaves at 1 mW/cm2do not alter the immune response of mice immunized againstS

ISSN:0197-8462    

DOI:10.1002/bem.2250070110

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

年代:1986

数据来源: WILEY

摘要:

AbstractFew studies are available that relate conductivity and temperature in solutions commonly used in tissue culture media. The purpose of this paper is to provide equations relating conductivity and temperature (in the range 20°C–40°C) for five solutions: 0.9% saline, MEM (Minimum Essential Media), horse serum, MEM with 1% horse serum, and MEM with 10% horse se

ISSN:0197-8462    

DOI:10.1002/bem.2250070111

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

年代:1986

数据来源: WILEY