摘要:

AbstractSimultaneous measurements were made of the electrocardiogram (ECG) and the intraarterial blood pressure of adult male Macaca monkeys during acute exposures to homogeneous stationary magnetic fields ranging in strength up to 1.5 tesla. An instantaneous, field strength‐dependent increase in the ECG signal amplitude at the locus of the T wave was observed in fields greater than 0.1 tesla. The temporal sequence of this signal in the ECG record and its reversibility following termination of the magnetic field exposure are consistent with an earlier suggestion that it arises from a magnetically induced aortic blood flow potential superimposed on the native T‐wave signal. No measurable alterations in blood pressure resulted from exposure to fields up to 1.5 tesla. This experimental finding is in agreement with theoretical calculations of the magnetohydrodynamic effect on blood flow in the major arteries of the cardiovascular sys

ISSN:0197-8462    

DOI:10.1002/bem.2250040102

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

年代:1983

数据来源: WILEY

摘要:

AbstractRats were exposed to a 60‐Hz electric field at an unperturbed field strength of 100 kV/m to determine its affect on bone growth and fracture repair. Exposure of immature male and female rats for 20 h/day for 30 days did not alter growth rate, cortical bone area, or medullary cavity area of the tibia. In another experiment, midfibular osteotomies were performed and the juvenile rats were exposed at 100 kV/m for 14 days. Evaluation by resistance to deformation and breaking strength indicated that fracture repair was not as advanced in the exposed animals as in the shamexposed animals. In another experiment measurements of resistance to deformation were made in adult rats at 16, 20, and 26 days after osteotmy. Fracture repair was slower in exposed compared to control animals at day 20 and, to a lesser extent, at day 16, but not at day 2

ISSN:0197-8462    

DOI:10.1002/bem.2250040103

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

年代:1983

数据来源: WILEY

摘要:

AbstractDirect determination of the microwave absorption characteristics of biological molecules in solution by an optical heterodyne technique is described. A visibly transparent sample is irradiated in a spatially nonuniform manner with pulsed microwaves, and the spatial variation in temperature increase measured by detecting the phase chirp impressed on a single‐frequency HeNe laser beam passing through the heated region. Results for several liquids and solutions such as water, methanol, various saline solutions, and solutions of DNA and DNA sodium salt in water are described. Where direct comparison is possible the results agree very well with published values. A significant increase in the absorption of DNA solutions compared with pure water has been observed that is consistent with microwave absorption by the longitudinal mode of the double he

ISSN:0197-8462    

DOI:10.1002/bem.2250040104

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

年代:1983

数据来源: WILEY

摘要:

AbstractTurkey sperm were exposed to 2.45‐GHz microwave radiation in a temperature‐controlled waveguide apparatus. Temperature was maintained at either 25 or 40.5 °C. The sperm were exposed for 30 min at a specific absorption rate (SAR) of 10 or 50 mW/g. Following irradiation, the sperm were used to inseminate virgin turkey hens artificially. During the 9 weeks following the single insemination, the following were assessed: mean number of eggs, percentage of fertile eggs, rate of decrease in egg fertility, percentage of hatched eggs, and percentage of early and late deaths. These data demonstrate that, for the conditions used in these experiments, microwave radiation has no effect on the fertilizing capacity of turkey s

ISSN:0197-8462    

DOI:10.1002/bem.2250040105

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

年代:1983

数据来源: WILEY

摘要:

AbstractNa+, K+, and Ca2+concentrations in the blood serum and submaxillary salivary gland (SSG) were investigated in adult, male rats exposed to 2880‐MHz microwaves modulated with 1.5‐μs pulses at a pulse repetition rate of 1000 Hz or in a hyperthermal environment. Rats were exposed, one at a time, for 30 min to microwaves producing a specific absorption rate (SAR) of: 4.2, 6.3,6.8,8.4, 10.8, or 12.6 W/kg, or were sham exposed under similar environmental conditions. In a second series, one group of rats was exposed singly for 15, 30, or 60 min to microwaves producing an SAR of 9.5 W/kg and other rats were exposed for similar periods at 40 °C; and 10 rats were sham exposed. Flame photometric analysis indicated that the thresholds of microwave radiation required to induce a change in Na+, K+, and Ca2+concentrations in the salivary glands are 6.8, 6.8, and 6.3 W/kg, respectively. The directions of Na+, K+, and Ca2+ion shifts in exposed rats' salivary glands are similar, whether affected by microwaves or hyperthermia. Greater changes in Na+and K+concentrations in SSG of rats exposed to microwaves for 15 and 30 min were found than in those exposed at 40 °C. On the other hand, exposure to hyperthermia at 40 °C or to microwaves for 1 h caused Na+concentration to be increased by 68.7 and 59.5% and K+concentration to be decreased by 29.6 and 21.7%, respe

ISSN:0197-8462    

DOI:10.1002/bem.2250040106

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

年代:1983

数据来源: WILEY

摘要:

AbstractTwo groups of 16 male New Zealand rabbits were exposed to 2450‐MHz continuous wave microwave fields in two experiments of 90 days each. The incident power densities of the first and second experiment were 0.5 and 5 mW/cm2, respectively. During each study, 16 animals were adapted to a miniature anechoic chamber exposure system for at least 2 weeks, then 8 of them were exposed for 7 h daily, 5 days a week for 13 weeks, and the other 8 animals were sham exposed. The rabbits were placed in acrylic cages, and each was exposed from the top in an individual miniature anechoic chamber. Thermography showed a maximum specific absorption rate of 5.5 W/kg in the head and 7 W/kg in the back at 5‐mW/cm2incident power density. After each 7‐h exposure session, the animals were returned to their home cages. Food consumption in the exposure chamber and body mass were measured daily. Blood samples were taken before exposure and monthly thereafter for hematological, morphological, chemical, protein electrophoresis, and lymphocyte blast transformation studies. Eyes were examined for cataract formation. Finally, pathological examinations of 28 specimens of organs and tissues of each rabbit were performed. Statistically, there was a significant (P<.01) decrease only of food consumption during the 5‐mW/cm2exposure; other variables were not significantly different between exposed and control

ISSN:0197-8462    

DOI:10.1002/bem.2250040107

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

年代:1983

数据来源: WILEY

摘要:

AbstractNumerous hematologic and serum chemistry variables were examined in rats exposed to unperturbed 60‐Hz electric fields at 100 kV/m for 15, 30, 60, or 120 days. Each study was replicated once. Rigorous statistical evaluations of these data did not detect any consistent effect of the electric field for exposures of up to 120 days. It was, however, not unusual in any individual study to detect certain variables that were significantly different between the exposed and shamexposed animals. This emphasizes the need for replicate designs and appropriate statistical analyses when investigating chemical or physical insults that may have minimal influence on biologic functio

ISSN:0197-8462    

DOI:10.1002/bem.2250040108

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

年代:1983

数据来源: WILEY

摘要:

AbstractA retrospective study on reproductive hazards was performed among 542 employees at Swedish power plants. Questionnaires were answered by 89% of the employees. Data on pregnancies were checked by studying hospital case records. There was a statistically significant, decreased frequency of „normal”︁ pregnancy outcome, almost exclusively due to an increased frequency of congenital malformations, when the father was a high‐voltage switchyard worker. The differences in pregnancy outcome could not be explained by any of the confounding factors analyzed. The total number of children with malformations (26) and the total number of pregnancies in this study, however, were ver

ISSN:0197-8462    

DOI:10.1002/bem.2250040109

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

年代:1983

数据来源: WILEY

摘要:

AbstractRabbit islets of Langerhans were exposed at 37 °C for 18 h to a low‐frequency‐pulsed magnetic field, generated in paired Helmholtz coils. Exposed islets showed a reduction of 26.1 ± 4.3% in45Ca2+content (P<.004). a reduction of 25.1 ± 6.3% in45Ca2+efflux (P<.006), and a reduction of 35.0 ± 8.7% (P<.002) in insulin released during glucose stimulation when compared with appropriate c

ISSN:0197-8462    

DOI:10.1002/bem.2250040110

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.2250040101

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

年代:1983

数据来源: WILEY