bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal field strength measurements in chick forebrains at 50, 147, and 450 MHz.
Authors: Weil Claude M. , Spiegel Ronald J. , Joines William T. 
Published: February 2006

AbstractThis report describes some experimental measurements of the internal field levels induced within isolated chick‐forebrains irradiated at 50, 147, and 450 MHz, under essentially the same conditions as those used in the in vitro calcium‐ion efflux experiments. Ratios of incident power at 50/147 MHz and 147/450 MHz that are needed to establish the same probe output are given and comparisons made with values predicted by different spherical models. Data predicted by the layered‐sphere model were found to be in close agreement with measured values for the 50/147‐MHz ratio. Agreement for the 147/450‐MHz ratio was poorer.
Biological effects of a 765‐kV, 60‐Hz transmission line on honey bees (Apis mellifera L.): Hemolymph as a possible stress indicator
Authors: Bindokas Vytautas , Greenberg Bernard 
Published: February 2006

AbstractNumber of circulating hemocytes and hemolymph protein patterns of adult worker honey bees were analyzed as possible indicators of stress resulting from colony placement under a 765‐kV transmission line. Although exposure to 55, 80, and 95 μA total induced hive current (THC) produced colony behavioral disturbance, there were no consistent effects on mean hemocyte counts at 55‐ or 95‐μA THC. Age‐dependent declines in circulating hemocyte number were similar in all exposure groups. There were no consistent differences in tube‐gel electropherograms. No consistent differences were found in two‐density slab‐gel electropherograms based on ultrasensitive silver stain. The 67 positively charged and four negatively charged protein fractions from overwintering bees are two‐ to threefold more than currently reported in the literature.
In utero exposure to microwave radiation and rat brain development
Authors: Merritt J. H. , Hardy K. A. , Chamness A. F. 
Published: February 2006

AbstractTimed‐pregnancy rats were exposed in a circular waveguide system starting on day 2 of gestation. The system operated at 2,450 MHz (pulsed waves; 8 μs PW; 830 pps). Specific absorption rate (SAR) was maintained at 0.4 W/kg by increasing the input power as the animals grew in size. On day 18 of gestation the dams were removed from the waveguide cages and euthanized; the fetuses were removed and weighed. Fetal brains were excised and weighed, and brain RNA, DNA and protein were determined. Values for measured parameters of the radiated fetuses did not differ significantly from those of sham‐exposed fetuses. A regression of brain weight on body weight showed no micrencephalous fetuses in the radiation group when using as a criterion a regression line based on two standard errors of the estimate of the sham‐exposed group. In addition, metrics derived from brain DNA (ie, cell number and cell size) showed no significant differences when radiation was compared to sham exposure. We conclude that 2,450‐MHz microwave radiation, at an SAR of 0.4 W/kg, did not produce significant alterations in brain organogenesis.
Cerebrovascular permeability to 86Rb in the rat after exposure to pulsed microwaves
Authors: Goldman Harold , Lin James C. , Murphy Sharon , Lin Mei F. 
Published: February 2006

AbstractMicrowaves (pulsed, 2,450 MHz) at an average power density of 3 W/cm2 were applied directly to the head for 5, 10, or 20 min, producing a peak specific absorption rate of 240 W/kg in the brain, which, after a 10‐min exposure, resulted in brain temperatures in excess of 43°C. A bolus of 86Rb in isotonic saline was injected intravenously and an arterial sample was collected for 20 s to determine cardiac output. Compared with unexposed controls, uptake of 86Rb increased most in those regions directly in the path of the irradiation, namely, the occipital and parietal cortex, as well as the dorsal hippocampus, midbrain, and basal ganglia. In a separate group of animals, regional brain‐vascular spaces were found to increase with brain temperature. These results support previous observations indicating that reliably demonstrable increases of blood‐brain barrier permeability are associated with intense, microwave‐induced hyperthermia, and that the observed changes are not due to field‐specific interaction.
Alterations in protein kinase activity following exposure of cultured human lymphocytes to modulated microwave fields
Authors: Byus Craig V. , Lundak Robert L. , Fletche Ramona M. , Adey W. Ross 
Published: February 2006

AbstractCultures of human tonsil lymphocytes were exposed in a Crawford cell to a 450‐MHz field (peak envelope intensity 1.0 mW/cm2), sinusoidally amplitude modulated (depth 80%) at frequencies between 3 and 100 Hz for periods up to 60 min. The Crawford cell was housed in a temperature‐controlled chamber (35°C) and control cultures were placed in the same chamber. Activity of cAMP‐dependent protein kinase relative to controls remained unaltered by fields modulated at 16 or 60 Hz with exposures of 15, 30, and 60 min. By contrast, total non‐cAMP‐dependent kinase activity fell to less than 50% of unexposed control levels after 15 and 30 min exposures, but, despite continuing field exposure, returned to control or preexposure levels by 45 and 60 min. A smaller reduction (20–25%) also occurred with 60‐Hz modulation and was also restricted to exposure durations of 15 and 30 min. CW 450‐MHz fields were without effect. Reduced enzyme activity occurred with 16‐, 40‐, and 60‐Hz modulation frequencies, but not with 3‐, 6‐, 80‐, or 100‐Hz modulation. The specific identity of this kinase is unknown. This rapid but transient reduction in lymphocyte protein kinase activity restricted to modulation frequencies between 16 and 60 Hz and to less than 30 min exposure is consistent with „windowing”︁ with respect to modulation frequency and exposure duration.
Short‐circuit currents, surface electric fields, and axial current densities for guinea pigs exposed to ELF electric fields.
Authors: Kaune W. T. , Miller M. C. 
Published: February 2006

AbstractShort‐circuit currents, surface electric fields, and axial current densities were measured in electrically grounded guinea pigs exposed to a uniform, vertical, ELF electric field. These data are 70–110% of corresponding values obtained in grounded rats exposed to the same electric field.
The relationship between flash evoked potentials and evoked amplitude modulation patterns of an applied UHF electromagnetic field in the rat
Authors: Kelley James T. , Everett Robert , Reilly Edward L. , Colton Glenn S. 
Published: February 2006

AbstractPilot studies demonstrate evidence that the electrophysiological processes associated with flash stimulation of the central nervous system (CNS) of rats, as seen in the recordings of visual‐evoked potentials, may also be detectable using an ultrahigh frequency electromagnetic field (UHFEMF). Patterns of amplitude modulation of an applied UHFEMF, when recorded and averaged, show strong correlations with simultaneously recorded evoked potentials. The data support the hypothesis that the UHFEMF amplitude is altered in a dynamic fashion by the tissue's electrophysiological processes that are involved with the generation of CNS electric fields.
SAR in rats exposed in 2,450‐MHz circularly polarized waveguides
Authors: Chou Chung‐Kwang , Guy Arthur W. , Johnson Robert B. 
Published: February 2006

AbstractAverage specific absorption rates (SARs) for live rats exposed in 2,450‐MHz circularly polarized waveguides were estimated from the total system loss determined from measurements using five power meters, and a correction factor representing actual SAR/apparent SAR. The actual SAR was measured by twin‐well calorimetry and the apparent SAR by power meters. Values were obtained for carcasses of various body masses for five orientations. The average SAR with free movement in the cages changed less than threefold as the rats grew from 200 to 700 g. The ratio of peak to average SAR in the body was less than 3. These results indicate relatively constant energy disposition in rats exposed in the circularly polarized waveguide.
Design of a magnetic field generator for experiments on magnetic effects in cell cultures
Authors: Kinouchi Y. , Ushita T. , Sato K. , Miyamoto H. , Yamaguchi H. , Yoshida Y. 
Published: February 2006

AbstractA magnetic field generator constructed of rare earth‐cobalt magnets is proposed for examining the biological effects of static magnetic fields (less than 1 T) on tissue cultures. Important quantities of a magnetic field from a biological‐effects viewpoint, ie, its strength and the product of strength and gradient, are analysed. A practical procedure for designing the generator with optimum parameters is given. Also, parameters are determined which will yield a sinusoidal spatial field distribution.
Calorimetric measurements of the effect of 330‐MHz radiofrequency radiation on human erythrocyte ghosts
Authors: Shnyrov Valery L. , Zhadan Galina G. , Akoev Inal G. 
Published: February 2006

AbstractIrreversible changes in the heat capacity of human erythrocyte ghost suspensions due to the effect of 330‐MHz radiofrequency radiation (at a specific absorption rate of approximately 9 mW/g) were detected by the method of scanning differential microcalorimetry. Using the data obtained from the analysis of infrared spectra of air‐dried films of erythrocyte membranes, it can be postulated that the observed microcalorimetric changes are connected with the local interaction of electromagnetic radiation with the channel‐forming portion of band‐3 protein.
The differential effects of 200, 591, and 2,450 MHz radiation on rat brain energy metabolism
Authors: Sanders Aaron P. , Joines William T. , Allis John W. 
Published: February 2006

AbstractThree key compounds in brain energy metabolism have been measured during and after exposure to continuous wave radiofrequency radiation at 200, 591, and 2,450 MHz. Frequency‐dependent changes have been found for all three compounds. Changes in NADH fluorescence have been measured on the surface of a surgically uncovered rat brain during exposure. At 200 and 591 MHz, NADH fluorescence increased in a dose‐dependent manner between approximately 1 and 10 mW/cm2, then became constant at higher exposures. There was no effect at 2,450 MHz. Levels of ATP and CP were measured in whole brain after exposure. The ATP levels were decreased at 200 and 591 MHz but not at 2,450 MHz. The CP levels decreased only at 591 MHz. The effect of duration of exposure (up to 5 min) was investigated for all compounds at 200 MHz and 2,450 MHz, and exposures to 20 minutes were examined at 591 MHz. Temperature in the rat brain was essentially constant for all exposures. A general mechanism for inhibition of the mitochondrial electron transport chain and the CP‐kinase reaction pathway by radiofrequency radiation has been proposed.
Assessment of the immune responsiveness of mice exposed to a 1.5‐Tesla stationary magnetic field
Authors: Tenforde T. S. , Shifrine M. 
Published: February 2006

AbstractHumoral and cell‐mediated immune responses were assayed following a 6‐day exposure of LAF1/J mice to a 1.50 Tesla (1 T = 104 Gauss) stationary magnetic field. In tests of the immune response to sheep erythrocytes, the number of Jerne plaques formed by spleen lymphocytes and the level of serum IgM were not significantly different for the exposed mice in comparison with control animals. Tests for mitogen‐induced lymphocyte proliferation also demonstrated no significant differences in the response of spleen lymphocytes from exposed and control groups of mice.
Current densities measured in human models exposed to 60‐Hz electric fields
Authors: Kaune W. T. , Forsythe W. C. 
Published: February 2006

AbstractThis paper gives current densities measured in homogeneous grounded human models exposed to vertical, 60‐Hz electric fields. The methods used for these measurements were validated by measuring the current densities induced in a grounded hemisphere and in a grounded prolate hemispheroid; agreement between measurement and theory was good. For an unperturbed field strength of 10 kV/m, current densities measured in the human chest were in the range 125–300 nA/cm2. A strong horizontal current‐density enhancement was observed in the axillae, with peak values of about 400 nA/cm2. The vertical current density in the arms, when held downward, was in the opposite direction to that in the chest. Current densities in the abdomen, pelvis, and legs were a strong function of whether the body was grounded through one or both feet. With one foot grounded, the horizontal current density in the lower pelvic region, just above the crotch, was 770 nA/cm2. This value was the largest of those measured in the head, arms, or torso of the human model. Scaling factors derived from these data and similar data for animals will provide a quantitative basis for comparing animal and human exposure to 60‐Hz electric fields. In addition, current‐density data given in this paper can be directly extrapolated to higher frequencies, at least to 1 MHz. These extrapolated data may be useful to individuals and groups involved in the determination of safety standards for the lower radiofrequency region.
Further studies of human whole‐body radiofrequency absorption rates
Authors: Hill Douglas A. 
Published: February 2006

AbstractFurther studies of human whole‐body radiofrequency (RF) absorption rates were carried out using a TEM‐cell exposure system. Experiments were done at one frequency near the grounded resonance frequency ( ∼ 40 MHz), and at several below‐resonance frequencies. Absorption rates are small for the K and H orientations of the body, even when grounded. For the body trunk in an E orientation, the absorption rate of a sitting person is about half of the rate for the same person standing with arms at the sides; the latter in turn is about half the rate for the same subject standing with arms over the head. Two‐body interactions cause no increase in absorption rates for grounded people. They do, however, increase the absorption rates for subjects in an E orientation in free space; the largest interaction occurs when one subject is λ/2 behind the other (as seen by the incident wave). When these results are applied to practical occupational exposure situations, the whole‐body specific absorption rate does not exceed the ANSI limit of 0.4 W/kg for exposures permitted by the ANSI standard (C95.1‐1982) at frequencies from 7 to 40 MHz.
Effects of microwave exposure on the hamster immune system. IV. Spleen cell IgM hemolytic plaque formation
Authors: Rao G. V. Rama , Cain C. A. , Tompkins W. A. F. 
Published: February 2006

AbstractMicrowave exposure has been reported to affect various components of the immune system. In this study, we examined the effect of a single whole‐body exposure of hamsters to microwave (mw) energy (2.45 GHz; 5–25 mW/cm2; 1 h) on the IgM antibody (Ab) response of spleen cells to sheep red blood cells (SRBC). MW‐exposed, sham‐exposed, and cage‐control hamsters were immunized with SRBC and plaque‐forming cells (PFC) in spleens assayed using the direct hemolytic plaque assay. In cage‐control hamsters the Ab response was highest between days 4 and 5, returning to baseline by day 9. MW exposure (25 mW/cm2 for 1 h) significantly augmented PFC response only on days 4 and 5 postimmunization, causing approximately a 4.3‐ and 3.5‐fold increase over controls, respectively. Exposure to 15 mW/cm2 caused a lesser, but significant increase in PFC. Exposure to intensities below 15 mW/cm2 for 1 h did not produce any increase in Ab response. Immunization with different concentrations of SRBC following 1 h of 25 mW/cm2 MW exposure revealed a stimulation in PFC at all concentrations ranging from 5 × 107 to 5 × 108 SRBC. Pretreatment of hamsters with MW radiation prior to immunization showed that the animals retained an increased sensitivity to SRBC for as long as 4 days after MW exposure. In contrast, exposure of hamsters to MW energy on different days after immunization showed an effect of the PFC response only if given between 0 and 1 day after immunization. These results suggest that MW exposure augments the primary IgM response to SRBC by affecting some early event in the immune response process. The various possible explanations for this phenomenon are discussed.
Effects of an extremely low frequency electromagnetic field on the cell division rate and plasma membrane of Paramecium tetraurelia
Authors: Dihel Larry E. , Smith‐Sonneborn Joan , Middaugh C. Russell 
Published: February 2006

AbstractThe eukaryotic protozoan, Paramecium, was examined as a model for effects of pulsated electromagnetic fields (PEMF) on cells. A 72‐Hz PEMF similar to fields employed clinically increased cell division rates in Paramecium by 8.5%. Two calcium transport mutants of these organisms showed differential responses to the same field. Verapamil, a calcium channel blocker, abolished any effect of PEMFs on cell division rates. A fluorescent probe that is thought to sense changes in membrane potential also manifested an altered response in the PEMF‐exposed cells whereas a fluorescent lipid bilayer fluidity probe produced evidence of decreased membrane fluidity in the exposed cells. An effect of PEMFs on ion transport mediated by either a direct or indirect effect on the cell membrane is suggestd by these studies.
Specific absorption rate in rats exposed to 2,450‐MHz microwaves under seven exposure conditions
Authors: Chou Chung‐Kwang , Guy Arthur W. , McDougall John A. , Lai Henry 
Published: February 2006

AbstractBoth positive and negative biological effects of microwaves on drug actions in rats exposed to 1‐mW/cm2, 2,450‐MHz microwaves have been reported by several investigators. We conducted dosimetry studies for seven different exposure conditions to determine whether these different results could be due to the rats having been exposed differently. They included anterior and posterior exposures in a circular waveguide, near field, far field with E‐or H‐field parallel to the long axis of the body and dorsal exposure in a miniature anechoic chamber with E‐ or H‐field parallel to the long axis of the body. The average specific absorption rates (SARs) in the head, tail, and body of the exposed rats were measured by means of a calorimetry system. The local SARs at eight locations in the brain were determined by temperature measurement with Vitek probes. Intensive coupling of energy to the tail when it was exposed parallel to the E‐field was shown by thermography. For the same average incident power density, the average SARs in the heads of rats were about two times higher in the circular waveguide than for other exposures. The local SARs in the brain varied for different exposure conditions. Statistical comparisons of SARs under the different exposure conditions are presented.
60‐Hz electric fields: Detection by female rats
Authors: Stern Sander , Laties Victor G. 
Published: February 2006

AbstractFemale rats were trained to detect a vertical, 60‐Hz electric field using the same apparatus and procedure we used previously to study behavioral detection of the field by male rats. Each rat was trained individually to press a lever in the presence of the field and not to press in its absence. Correct detections occasionally produced a food pellet. The probability of detecting the field increased 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—varied among rats between 3 and 10 kV/m. Behavioral detection by female rats was indistinguishable from that by male rats.
Blood‐brain barrier permeation in the rat during exposure to low‐power 1.7‐GHz microwave radiation
Authors: Ward T. R. , Ali J. S. 
Published: February 2006

AbstractThe permeability of the blood‐brain barrier to high‐ and low‐molecular‐weight compounds has been measured as a function of continuous‐wave (CW) and pulsed‐microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [14C] sucrose and [3H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7‐GHz CW and pulsed (0.5‐μs pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham‐exposed animals.
Low‐voltage ELF electric field measurements in ionic media
Authors: Gundersen R. , Greenebaum B. 
Published: February 2006

AbstractLow‐voltage electric fields were measured in conductive tissue culture media using three techniques: voltage slope, current density‐conductivity, and dipole methods. All three methods tested yielded comparable results. However, all three techniques have associated errors. These errors fall into three major categories: 1) those associated with the measurement equipment, 2) those associated with electrodes, and 3) errors in cross‐sectional area measurements. Each source of error is discussed so that all can be taken into account during construction and/or testing of exposure equipment.
Potassium ion influx measurements on cultured Chinese hamster cells exposed to 60‐Hertz electromagnetic fields
Authors: Stevenson Anita P. , Tobey Robert A. 
Published: February 2006

AbstractPotassium ion influx was measured by monitoring 42KCI uptake by Chinese hamster ovary (CHO) cells grown in suspension culture and exposed in the culture medium to 60–Hz electromagnetic fields up to 2.85 V/m. In the presence of the field CHO cells exhibited two components of uptake, the same as previously observed for those grown under normal conditions; both these components of influx were decreased when compared to sham‐exposed cells. Although decreases were consistently observed in exposed cells when plotted as logc of uptake, the differences between the means of the calculated fluxes of exposed and sham‐exposed cells were quite small (on the order of 4–7%). When standard deviations were calculated, there was no significant difference between these means; however, when time‐paired uptake data were analyzed, the differences were found to be statistically significant. Cells exposed only to the magnetic field exhibited similar small decreases in influx rates when compared to sham‐exposed cells, suggesting that the reduction in K+ uptake could be attributed to the magnetic field. Additionally, intracellular K+ levels were measured over a prolonged exposure period (96 h), and no apparent differences in intracellular K+ levels were observed between field‐exposed and shamexposed cultures. These results indicate that high‐strength electric fields have a small effect on the rate of transport of potassium ions but no effect on long‐term maintenance of intracellular K+.
Microwave radiation absorption in the rat: Frequency‐dependent SAR distribution in body and tail
Authors: D'Andrea John A. , Emmerson Rita Y. , Bailey Cory M. , Olsen Richard G. , Gandhi Om P. 
Published: February 2006

AbstractExperiments were conducted using twin‐well calorimetry to determine the averaged whole‐body specific absorption rate (SAR) for rat carcasses exposed to 360, 700, 915, and 2,450 MHz CW radiation in an anechoic chamber. All exposures were done with the long axis of the rat in an E‐polarization. Additional experiments were conducted using a fiber optical temperature probe to determine local SAR in the brain, esophagus, colon, rectum, and tail during microwave exposure. The whole‐body averaged SAR for the radiation frequencies examined follows a nonmonotonic function with 700 MHz as the resonant frequency. This result agrees with previous analytical estimates. Local SARs within the body and tail are nonuniform with significant frequency‐specific hotspots in the colon, rectum, and tail.