bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave‐induced changes in nerve cells: Effects of modulation and temperature
Authors: Arber Simon L. , Lin James C. 
Published: February 2006

AbstractHelix aspersa neurons were irradiated with continuous‐wave (CW) and noise‐amplitudemodulated microwaves (carrier frequency 2450 MHz, 20% AM, 2 Hz‐20 kHz) in a specially designed waveguide exposure system. Continuous‐wave microwave irradiations were conducted at 8°, 21°, and 28°C, while noise‐modulated irradiation was performed at 21°C. The results showed that exposure of snail neurons to CW microwaves for 60 min at 12.9 W/kg inhibited spontaneous activity and reduced input resistance at 8° and 21°C but not at 28°C. The relative decrease in resistance at 21°C was half that at 8°C. Exposure of neurons to noise‐modulated microwaves at 6.8 and 14.4 W/kg predominately caused excitatory responses characterized by augmented membrane resistance and the appearance of greater activity. The effect differed qualitatively from the inhibition observed with continuous, unmodulated microwave irradiation.
Effect of microwave irradiation (2.45 GHz, CW) on egg weight loss, egg hatchability, and hatchling growth of the Coturnix quail
Authors: Byman David , Battista Sam P. , Wasserman Fred E. , Kunz Thomas H. 
Published: February 2006

AbstractFertile eggs of the Coturnix quail were exposed twice a day for 30 min to 2.45‐GHz continuous wave radiation at power densities of 25 or 50 mW cm−2 throughout the 17‐day incubation period. Other eggs were exposed to 20°C or 24°C temperatures twice daily. Repeated exposures to 20°C, 24°C, or 25 mW cm−2 did not reduce hatchability. Irradiation at 50 mW cm−2 lowered hatchability, probably as a result of high egg temperatures. Hatchlings that had been irradiated by microwaves as embryos had normal growth rates and no obvious developmental abnormalities.
Erythrocyte hemolysis by radiofrequency fields
Authors: Cleary Stephen F. , Liu Li‐Ming , Garber Francine 
Published: February 2006

AbstractA field‐strength‐dependent hemolytic effect of continuous‐wave radiofrequency (RF) exposure in vitro has been demonstrated. Erythrocytes in whole heparinized rabbit blood were hemolyzed by a 2‐h exposure to 50‐ or 100‐MHz RF fields at field strengths of greater than 4 V/cm. An effect of comparable magnitude resulted from exposure to 10‐MHz RF at a field strength of 9 V/cm. Sample temperatures were maintainted at 22.5° ± 0.2°C. There was no apparent involvement of heating or temperature gradients, nor were there any RF exposure effects on cellular K+ or Na+ concentration, nor on pH. The mechanism of the hemolytic effect is not known. Since the percentage of lysed erythrocytes was less than 1% and there was an absence of effects on cellular cation concentrations, RF radiation may have irreversibly altered the plasma membrane permeability of a sensitive subpopulation of red cells (possibly aged cells) leading to osmotic lysis. RF radiation at these frequencies appears to affect red cells in a manner that is qualitatively and quantitatively different from microwave radiation.
Thermoregulatory consequences of long‐term microwave exposure at controlled ambient temperatures
Authors: Adair Eleanor R. , Spiers Donald E. , Rawson Robert O. , Adams Barbara W. , Sheldon Douglas K. , Pivirotto Philip J. , Akel Gillian M. 
Published: February 2006

AbstractThis study was designed to identify and measure changes in thermoregulatory responses, both behavioral and physiological, that may occur when squirrel monkeys are exposed to 2450‐MHz continuous wave microwaves 40 hr/week for 15 weeks. Power densities of 1 or 5 mW/cm2 (specific absorption rate = 0.16 W/kg per mW/cm2) were presented at controlled environmental temperatures of 25, 30, or 35°C. Standardized tests, conducted periodically, before, during, and after treatment, assessed changes in thermoregulatory responses. Dependent variables that were measured included body mass, certain blood properties, metabolic heat production, sweating, skin temperatures, deep body temperature, and behavioral responses by which the monkeys selected a preferred environmental temperature. Results showed no reliable alteration of metabolic rate, internal body temperature, blood indices, or thermoregulatory behavior by microwave exposure, although the ambient temperature prevailing during chronic exposure could exert an effect. An increase in sweating rate occurred in the 35°C environment, but sweating was not reliably enhanced by microwave exposure. Skin temperature, reflecting vasomotor state, was reliably influenced by both ambient temperature and microwaves. The most robust consequence of microwave exposure was a reduction in body mass, which appeared to be a function of microwave power density.
Noninvasive thermometry using multiple‐frequency‐band radiometry: A feasibility study
Authors: Prionas Stavros D. , Hahn G. M. 
Published: February 2006

AbstractThe potential use of multiple‐frequency‐band radiometry as a means of noninvasive sensing of one‐dimensional temperature profiles is presented in this communication. The radiative energy transfer equation is solved numerically. Ideal‐condition thermal noise spectra and distributions of received energy, associated with specific temperature‐depth profiles, are presented. Performance characteristics are discussed.
Biological effects of high‐frequency electromagnetic fields on Salmonella typhimurium and Drosophila melanogaster
Authors: Hamnerius Yngve , Rasmuson Åsa , Rasmuson Bertil 
Published: February 2006

AbstractSalmonella typhimurium and Drosophila melanogaster were exposed to continuous wave (CW) 2.45‐GHz electromagnetic radiation, pulsed 3.10‐GHz electromagnetic radiation, CW 27.12‐MHz magnetic fields, or CW 27.12‐MHz electric fields (only Drosophila). The temperatures of the treated sample and the nonexposed control sample were kept constant. The temperature difference between exposed and control samples was less than ± 0.3°C. Ames' assays were made on bacteria that had been exposed to microwaves (SAR 60–130 W/kg) or RF fields (SAR up to 20 W/kg) when growing exponentially in nutrient broth. Survival and number of induced revertants to histidine prototrophy were determined by common plating techniques on rich and minimal agar plates. The Drosophila test consisted of a sensitive somatic system where the mutagenicity was measured by means of mutations in a gene‐controlling eye pigmentation. In none of these test systems did microwave or radiofrequency fields induce an elevated mutation frequency. However, a significantly higher concentration of cells was found in the bacterial cultures exposed to the 27‐MHz magnetic field or 2.45‐GHz CW and 3.10‐GHz pulsed microwave radiation.
Regional turnover of norepinephrine and dopamine in rat brain following acute exposure to air ions
Authors: Charry Jonathan M. , Bailey William H. 
Published: February 2006

AbstractExposure to air ions has been reported to influence serotonin (5HT), although critical reviews of these studies and previous measurements in our laboratory of the concentration, release, and utilization of brain 5HT indicate that neither the data nor the interpretations of the data are particularly convincing. Measurements of other possibly relevant neuro‐transmitter systems—norepinephrine (NE) and dopamine (DA)—were made in brain regions selected because of their importance in the modulation of brain functions relating to motivation, arousal, endocrine function, and motor activity, all responses that have been reported to be influenced by air ion exposure. Results indicate that exposure of male Holtzman rats to high concentrations (5.0 × 105/cm3) of positive or negative air ions or to DC electric fields (3.0 kV/m) for periods up to 66 h failed to affect the concentration of NE or DA significantly in any of the brain regions.
Sine waves enhance cellular transcription
Authors: Goodman Reba , Henderson Ann S. 
Published: February 2006

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 RNA.
Postmortem changes of the dielectric properties of bovine brain tissues at low radiofrequencies
Authors: Surowiec A. , Stuchly S. S. , Swarup Arvind 
Published: February 2006

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 species.
Magnetic field measurements near RF induction heaters
Authors: Conover David L. , Murray William E. , Lary Joseph M. , Johnson Peggy H. 
Published: February 2006

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/m2 and 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).
Circulating antibody response of mice exposed to 9‐GHz pulsed microwave radiation
Authors: Liddle C. G. , Putnam J. P. , Lewter O. H. , West M. , Morrow G. 
Published: February 2006

AbstractFemale CD‐1 mice immunized against the bacterium Streptococcus pneumoniae type 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/cm2 do not alter the immune response of mice immunized against S pneumoniae.
Dosimetric study of microwave cataractogenesis
Authors: Foster Mark R. , Ferri Esther S. , Hagan Gary J. 
Published: February 2006

AbstractA closed waveguide method has been used to induce opacities in the rabbit eye. A 30‐min exposure to 2.45‐GHz radiation such that 8.7 W is incident on the head (5.75 W being absorbed) produces a cataract in half of the exposed eyes of New Zealand white rabbits.
Dielectric behavior of water in biological solutions: Studies on myoglobin, human low‐density lipoprotein, and polyvinylpyrrolidone
Authors: Grant E. H. , McClean V. E. R. , Nightingale N. R. V. , Sheppard R. J. , Chapman M. J. 
Published: February 2006

AbstractThe dielectric behavior of the aqueous solutions of three widely differing macromolecules has been investigated: myoglobin, polyvinylpyrrolidone (PVP), and human serum low‐density lipoprotein (LDL). It was not possible to interpret unambiguously the dielectric properties of the PVP solution in terms of water structure. The best interpretation of the dielectric data on the myoglobin and LDL solutions was that, in both cases, the macromolecule attracts a layer of water of hydration one or two water molecules in width. For LDL, this corresponds to a hydration factor of only 0.05 g/g, whereas for myoglobin the figure is nearer 0.6 g/g. With myoglobin, part of the water of hydration exhibits its dispersion at frequencies of a few GHz, and the rest disperses at lower frequencies, perhaps as low as 10–12 MHz. The approximate constancy of the width of the hydration shell for two molecules as dissimilar in size as LDL and myoglobin confirms that the proportion of water existing as water of hydration in a biological solution depends critically on the size of the macromolecules as well as on their concentration.
Dynamic characteristics of membrane ions in multifield configurations of low‐frequency electromagnetic radiation
Authors: McLeod B. R. , Liboff Abraham R. 
Published: February 2006

AbstractWe seek to extend the recent suggestion that classical cyclotron resonance of biologically important ions is implicated in weak electromagnetic field‐cell interactions. The motion of charged particles in a constant magnetic field and periodic electric field is examined under the simplifying assumption of no damping. Each of the nine terms of the relative dielectric tensor is found to have a dependence on functions that include the factor (ω2 – ω)−1, where ωB is the gyrofrequency. We also find a plasmalike decomposition of the electric field into oppositely rotating components that could conceivably act to drive oppositely charged ions in the same direction through helical membrane channels. For weak low‐frequency magnetic fields, an additional feature arises, namely, periodic reinforcement of the resonance condition with intervals of the order of tens of msec for biological ions such as Li+, Na+, and K+.
Cardiovascular, hematologic, and biochemical effects of acute ventral exposure of conscious rats to 2450‐MHz (CW) microwave radiation
Authors: Galvin M. J. , McRee D. I. 
Published: February 2006

AbstractIn this study the influence of acute (6 hr) exposure to 2450 MHz (CW) microwave radiation on certain cardiovascular, biochemical, and hematologic indices was examined in unanesthetized rats. Under methoxyflurane anesthesia, a catheter was inserted into the right femoral artery, which was used for monitoring blood pressure, heart rate, and blood sampling. Colonic temperature was monitored via a VITEK thermistor probe inserted rectally to a depth of 5 cm. The rat was subsequently placed into a ventilated restraining cage which was located inside an anechoic chamber. The temperature and humidity in the chamber were maintained at 22 ± 0.5°C and 60 ± 5% (means ± S.E.), respectively, during the experimental period. Rats (60) were exposed to either 0 (sham) or 10 mW/cm2 (exposed) for 6 hr. During exposure rats were oriented perpendicular to the E‐field, and the measured specific absorption rate (SAR) was 3.7 mW/g. In the sham and exposed rats, the preexposure (time 0) mean ± S.E. arterial blood pressure (MABP), heart rate, and colonic temperature were approximately 120 ± 5 mmHg, 450 ± 10 beats/min, and 37.0 ± 0.2 °C, respectively. In the sham‐exposed rats these values remained stable throughout the 6‐hr exposure period. In the exposed rats, no effects were noted on MABP or colonic temperature; however after 1 hr of exposure, a significant reduction in heart rate was noted (450 versus 400 beats/min). This decrease in heart rate persisted throughout the remainder of the exposure period. None of the hematologic or biochemical parameters examined were affected by the microwave exposure. Although other mechanisms may be responsible, this decrease in heart rate may have been due to subtle cardiovascular adjustments because of microwave‐induced heating with a resultant reduction in resting metabolic rate.
60‐Hz electric‐field effects on pineal melatonin rhythms: Time course for onset and recovery
Authors: Wilson B. W. , Chess E. K. , Anderson L. E. 
Published: February 2006

AbstractRats exposed for 3 weeks to uniform 60‐Hz electric fields of 39 kV/m (effective field strength) failed to show normal pineal gland circadian rhythms in serotonin N‐acetyl transferase activity and melatonin concentrations. The time required for recovery of the melatonin rhythm after cessation of field exposure was determined to be less than 3 days. The rapid recovery suggests that the overall metabolic competence of the pineal is not permanently compromised by electric‐field exposure, and that the circadian rhythm effect may be neuronally mediated.
Use of the loss‐tangent function in dielectric spectroscopy
Authors: Surowiec Andrzej , Stuchly Stanislaw S. 
Published: February 2006

AbstractA new method for finding the dielectric parameters of biological substances is presented. The method makes use of the loss‐tangent as a function of frequency to identify the dominating relaxation process. The method was tested for a few cell suspensions (blood and lymphocytes) and two tissues (liver and spleen). The obtained parameters agree well with those calculated from Maxwell‐Wagner theory (β dispersion).
Measurement of small mechanical vibrations of brain tissue exposed to extremely‐low‐frequency electric fields
Authors: Spiegel R. J. , Ali J. S. , Peoples J. F. , Joines W. T. 
Published: February 2006

AbstractElectromagnetic fields can interact with biological tissue both electrically and mechanically. This study investigated the mechanical interaction between brain tissue and an extremely‐low‐frequency (ELF) electric field by measuring the resultant vibrational amplitude. The exposure cell is a section of X‐band waveguide that was modified by the addition of a center conductor to form a small TEM cell within the waveguide structure. The ELF signal is applied to the center conductor of the TEM cell. The applied ELF electric field generates an electrostrictive force on the surface of the brain tissue. This force causes the tissue to vibrate at a frequency equal to twice the frequency of the applied sinusoidal signal. An X‐band signal is fed through the waveguide, scattered by the vibrating sample, and detected by a phase‐sensitive receiver. Using a time‐averaging spectrum analyzer, a vibration sensitivity of approximately 0.2 nmp‐p can be achieved. The amplitude of the brain tissue vibrational response is constant for vibrational frequencies below 50 Hz; between 50 and 200 Hz resonant phenomena were observed; and above 200 Hz the amplitude fall‐off is rapid.
Intermittent exposure of rats to 2450 MHz microwaves at 2.5 mW cm2: Behavioral and physiological effects
Authors: D'Andrea John A. , Dewitt John R. , Emmerson Rita Y. , Bailey Cory , Stensaas Suzanne , Gandhi Om P. 
Published: February 2006

AbstractLong‐Evans male adult rats were intermittently exposed for 14 weeks to continuous wave (CW) 2450‐MHz microwaves at an average power density of 2.5 mW/cm2. The mean specific absorption rate was 0.70 W/kg (± 0.02 SEM). The rats were exposed 7 h/day, 7 days/week in a radiation chamber with a monopole above ground, while housed in Plexiglas cages. Weekly measures of body mass and food intake did not indicate statistically significant effects of microwave irradiation. Assessments of threshold for electric‐footshock detection revealed a significant difference between microwave and sham‐exposed animals. Assessments of cholinesterase and sulfhydryl groups in blood and 17‐ketosteriods in urine did not distinguish the two groups of rats. Behavioral measures made at the end of the 14‐week exposure included an open‐field test, shuttlebox avoidance performance, and schedule‐controlled lever‐pressing for food pellets. Statistically significant differences between microwave‐ and sham‐exposed rats were observed for these measures. Examination of adrenal tissue, plasma electrolytes, and organ masses after 14 weeks of exposure revealed no difference between the two groups of rats.
Behavioral monitoring of rats during exposure to air ions and DC electric fields
Authors: Bailey William H. , Charry Jonathan M. 
Published: February 2006

AbstractAir ions and direct current (DC) electric fields have been reported to exert subtle behavioral and biological effects on rodents and humans. These effects often appear inconsistent, yet there have been few attempts to resolve these inconsistencies by experimental replication. Rats exposed to negatively or positively charged air ions over a wide range of concentrations and exposure periods have been reported to show alterations in their level of locomotor activity. In this study, locomotor activity of Sprague‐Dawley rats was quantified during exposure to either (1) unipolar air ions and DC fields of the same polarity or (2) DC fields alone. Both polarities were studied. Air ion concentrations were 5.0 × 103, DC fields were 3 kV/m, and exposures lasted 2, 18, or 66 h. In one experiment rats were exposed to DC fields of 12 kV/m. No exposure condition exerted any effect on locomotor activity or rearing behavior. In addition, no behavioral perturbations were observed after the onset of any of the exposure conditions, suggesting that the rats may have failed to detect the altered environment.
Thermoregulation in rodents exposed to high‐intensity stationary magnetic fields
Authors: Tenforde T. S. 
Published: February 2006

AbstractRectal temperatures were recorded in mice and rats during exposure to a stationary 7.55 Tesla (1 T = 104 Gauss) homogeneous magnetic field, and to magnetic field gradients ranging from 58.1–58.6 T/m. Contrary to observations reported recently by other investigators, no evidence was found for a change in the body temperature of rodents exposed to strong homogeneous or gradient magnetic fields.
Microwave effects on isolated chick embryo hearts
Authors: Caddemi A. , Tamburello C. C. , Zanforlin L. , Torregrossa M. V. 
Published: February 2006

AbstractThis study was designed to examine the effects of microwaves on the electric activity of hearts as a means of elucidating interactive mechanisms of nonionizing radiations with cardiac tissue. Experiments were performed on isolated hearts of 9–12‐day‐old chick embryos placed in small petri dishes. Oxygenated isotonic Ringer's solution at 37°C permitted heart survival. Samples were irradiatd at 2.45 GHz with a power density of 3 mW/cm2. The heart signal was detected with a glass micropipet inserted into the sinoatrial node and examined by means of a Berg‐Fourier analyzer. Pulsed microwaves caused the locking of the heartbeat to the modulation frequency, whereas continuous wave irradiation might have induced slight bradycardia. Pulsed fields induced stimulation or regularization of the heartbeat in arrhythmia, fibrillation, or arrest of the heart.
Lack of an effect of static magnetic field on calcium efflux from isolated chick brains
Authors: Bellossi A. 
Published: February 2006

Abstract45Ca2+ efflux from neonatal isolated chick brains was measured. The brains were exposed to uniform or nonuniform static magnetic fields. The field intensity ranged from 200–900 mT. The exposure took place during incubation and/or when efflux was being measured. No difference appeared in the 45Ca2+ efflux between controls and exposed brains.