bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of short electromagnetic pulses on brain acetylcholine content and spontaneous motor activity of mice
Authors: Modak A. T. , Stavinoha W. B. , Deam A. P. 
Published: February 2006

AbstractMice were exposed to a single 15‐ms or 25‐ms pulse of 2,450‐MHz microwaves which increased brain temperature by 2 °C or 4 °C, respectively. Immediately after exposure, the mice became hypokinetic but began recovering within 5 minutes. The 25‐ms pulse (18.7 j deposited in the brain) caused a significant decrease in acetylcholine content of the whole brain, probably owing to increased permeability of the membrane.
Endocrinological effects of strong 60‐Hz electric fields on rats
Authors: Free Michael J. , Kaune William T. , Phillips Richard D. , Cheng Hsien‐Chen 
Published: February 2006

AbstractAdult male rats were exposed or sham‐exposed to 60‐Hz electric fields without spark discharges, ozone, or significant levels of other secondary variables. No effects were observed on body weights or plasma hormone levels after 30 days of exposure at an effective field strength of 68 kV/m. After 120 days of exposure (effective field strength = 64 kV/m), effects were inconsistent, with significant reductions in body weight and plasma levels of follicle‐stimulating hormone and corticosterone occurring in one replicate experiment but not in the other. Plasma testosterone levels were significantly reduced after 120 days of exposure in one experiment, with a similar but not statistically significant reduction in a replicate experiment. Weanling rats, exposed or sham‐exposed in electric fields with an effective field strength of 80 kV/m from 20 to 56 days of age, exhibited identical or closely similar growth trends in body and organ weights. Hormone levels in exposed and sham‐exposed groups were also similar. However, there was an apparent phase shift between the two groups in the cyclic variations of concentrations of hormones at different stages of development, particularly with respect to follicle‐stimulating hormone and corticosterone. We concluded that 60‐Hz electric fields may bring about subtle changes in the endocrine system of rats, and that these changes may be related to alterations in episodic rhythms.
Effects of millimeter‐wave radiation on monolayer cell cultures. I. Design and validation of a novel exposure system
Authors: Partlow L. M. , Bush L. G. , Stensaas L. J. , Hill D. W. , Riazi A. , Gandhi O. P. 
Published: February 2006

AbstractA method has been devised whereby both the thermal and possible athermal biological effects resulting from microwave radiation can be assessed. Monolayer cultures of BHK‐21/C13 cells were grown on microwave‐transparent polystyrene coverslips, placed directly on the open end of a wave guide, and irradiated for 1 hour. In experiments seeking athermal biological effects of millimeter waves, culture medium was continuously recirculated over the cells to prevent temperature increases greater than 0.1 °C. Incorporation of 3H‐uridine into RNA and of 3H‐methionine into protein was quantified by measurement of optical densities of the autoradiographs in contiguous rectangular regions corresponding to portions of the cell monolayer immediately above the wave guide aperture and lying along its longer axis. Since power density was shown to vary with position along this axis according to a cosine2 relationship, it was possible to assess the extent of microwave effects on macromolecular synthesis at power densities ranging from zero at each edge to twice the average power density at the center of the waveguide.Monolayer cultures maintained at 37.2 °C by recirculation of the medium did not show microwave‐induced changes in synthesis of RNA and protein (41.8 or 74.0 GHz at average power densities of 320 or 450 mW/cm2, respectively). Since macromolecular synthesis was examined both during and after irradiation, our results exclude both transient and persistent athermal biological effects of acute exposure to millimeter waves. In contrast, irradiation of cultures incubated in a small volume of nonrecirculated medium resulted in 1) marked heating of the monolayer, 2) a graded decline in macromolecular synthesis with increasing incident power, and 3), in some cases, destruction of the cell monolayer in the region immediately above the center of the waveguide aperture.
Development of xenopus laevis embryos in a static magnetic field
Authors: Mild Kjell Hansson , Sandström Monic , Løvtrup Søren 
Published: February 2006

AbstractXenopus laevis embryos were exposed to a DC magnetic field (2.5 kG) for periods up to 1 week. The previously reported stabilization of cell membranes by stationary magnetic fields could not be demonstrated.
Chronic exposure to a 60‐Hz electric field: Effects on neuromuscular function in the rat
Authors: Jaffe R. A. , Laszewski B. L. , Carr D. B. 
Published: February 2006

AbstractNeuromuscular function in adult male rats was studied following 30 days of exposure to a 60‐Hz electric field at 100 kV/m (unperturbed field strength). Isometric force transducers were attached to the tendons of the plantaris (predominantly fast twitch), and soleus (predominantly slow twitch) muscles in the urethan‐anesthetized rat. Square‐wave stimuli were delivered to the distal stump of the transected sciatic nerve. Several measurements were used to characterize neuromuscular function, including twitch characteristics, chronaxie, tetanic and posttetanic potentiation, and fatigue and recovery. The results from three independent series of experiments are reported. Only recovery from fatigue in slow‐twitch muscles was consistently and significantly affected (enhanced) by electrifield exposure. This effect does not appear to be mediated by field‐induced changes in either neuromuscular transmission, or in the contractile mechanism itself. It is suggested that the effect may be mediated secondary to an effect on mechanisms regulating muscle blood flow or metabolism.
Effect of nonionizing radiation on the purkinje cells of the uvula in squirrel monkey cerebellum
Authors: Albert E. N. , Sherif M. F. , Papadopoulos N. J. 
Published: February 2006

AbstractPregnant squirrel monkeys were exposed to 2450‐MHz (CW) microwaves at an equivalent power density of 10 mW/cm2 (SAR 3.4 mW/g) for three hours daily in a cavity‐cage module. The exposure began when pregnancy was determined by a hormonal method, and continued through the offspring's first 9.5 months. After irradiation, the brains of the offspring were fixed with formaldehyde, and the inferior vermis of each cerebella was removed and processed for histologic observations. Purkinje cell density in the uvula was determined in sagittal serial sections. There was no significant difference between control and experimental animals in the number of Purkinje cells per mm of Purkinje cell line (linear density), as well as in the density of Purkinje cells in the Purkinje cell layer.
Biological effects of long‐term exposure of rats to 970‐MHz radiofrequency radiation
Authors: Smialowicz R. J. , Weil C. M. , Marsh P. , Riddle M. M. , Rogers R. R. , Rehnberg B. F. 
Published: February 2006

AbstractRats (N = 16) exposed individually in circularly polarized waveguides to 970‐MHz electromagnetic radiation (SAR=2.5 mW/g, 22 h daily for 70 consecutive days) had significantly higher serum levels of triglycerides, albumin, and total protein compared with sham‐irradiated controls. No difference was observed in the weights, hematologic profile, or in vitro lymphocyte responses to mitogens between these two groups. The higher serum levels of triglycerides in radiofrequency‐radiation‐exposed rats suggest a non‐specific stress reaction.
Effects of intermittent 60‐Hz high voltage electric fields on metabolism, activity, and temperature in mice
Authors: Rosenberg R. S. , Duffy P. H. , Sacher G. A. 
Published: February 2006

AbstractTransient effects of 100‐kV/m extremely low frequency electric fields were studied in the white footed deermouse, Peromyscus leucopus. Gross motor activity, carbon dioxide production, oxygen consumption, and core body temperature were monitored before, during, and after intermittent field exposures (four hour‐long exposures, at one‐hour intervals). Thirty‐four mice were exposed in cages with plastic floors floating above ground potential, and 21 mice were exposed in cages with grounded metal floor plates. The first field exposure produced an immediate, transient increase of activity and gas measures during the inactive phase of the circadian cycle. All measures returned to baseline levels before the second exposure and were not significantly changed throughout the remainder of the exposures. The rapid habituation of field‐induced arousal suggests that significant metabolic changes will not be measured in experiments in which the interval between exposure and measurement is greater than two hours.
Longevity and food consumption of microwave‐treated (2.45 GHz Cw) honeybees in the laboratory
Authors: Westerdahl Becky Brown , Gary Norman E. 
Published: February 2006

AbstractAdult honeybees, confined singly or in small clusters, were exposed for 0.5, 6, and 24 hours to 2.45‐GHz continuous wave microwave radiation at power densities of 3, 6, 12, 25, and 50 mW/cm2. Following exposure, bees were held in the incubator for 21 days to determine the consumption of sucrose syrup and to observe mortality. No significant differences were found between microwave‐treated and sham‐treated or control bees.
Inhibition and recovery of growth processes in roots of pisum sativum L. Exposed to 60‐Hz electric fields
Authors: Robertson Dominique , Miller Morton W. , Cox Christopher , Davis Henry T. 
Published: February 2006

AbstractRoots of Pisum sativum L. were chronically exposed in aqueous inorganic nutrient medium to 60‐Hz electric fields between 140 and 490 V/m (growth medium conductivity ∼ 0.08 S/m). The growth rate, meristematic mitotic index, and growth rate recovery of the roots were determined. At 140 V/m there was no perturbation in growth rate or mitotic index. At 430 V/m the growth rate and the mitotic index were reduced. The mitotic index had a maximum depression (∼ 55% of control), which occurred at 4 h. The depression in growth rate was immediate and constant over time. When roots were exposed to an electric field at 430 V/m for 2 days, the growth rate was depressed by about 40%. When the field was terminated, the growth rate steadily increased and was almost normal after 5 days. At 490 V/m root growth rate was almost completely arrested. According to these results, there is a narrow range of induced membrane potentials that span the range from slightly altered to almost completely arrested growth rates.
Thermoregulatory physiologic responses in the human body exposed to microwave radiation
Authors: Way W. I. , Kritikos H. , Schwan H. 
Published: February 2006

AbstractBy introduction of an additional compartment in the hypothalamic region Stolwijk's thermo‐regulatory model has been modified to consider partial heating due to hot spots induced by microwaves. It was found that because of thermoregulatory action, the temperature of the hypothalamus will not increase drastically until the rate of energy deposition exceeds the threshold level of about 50 mW/g. The primary controlling mechanisms are blood flow and sweating. For an energy deposition rate of 10 mW/g in the hypothalamus the increase in blood flow in the skin is negligible and the temperature rise of the hypothalamus as compared with blood temperature is about 0.5 °C. It was found that exposure of the head to electromagnetic radiation, in general, causes a decrease in temperature of the trunk and skin. The results show that while the deposition of energy in the hypothalamus at the rate of 10 mW/g produced significant conductive and convective effects, the same total energy uniformly distributed over the cranial cavity produces less significant effects.
Chronic exposure to 60‐Hz electric fields: Effects on pineal function in the rat
Authors: Wilson Bary W. , Anderson Larry E. , Ian Hilton D. , Phillips Richard D. 
Published: February 2006

AbstractAs a component of studies to search for effects of 60‐Hz electric field exposure on mammalian endocrine function, concentrations of melatonin, 5‐methoxytryptophol, and serotonin‐Nacetyl transferase activity were measured in the pineal glands of rats exposed or sham‐exposed at 65 kV/m for 30 days. In two replicate experiments there were statistically significant differences between exposed and control rats in that the normal nocturnal increase in pineal melatonin content was depressed in the exposed animals. Concentrations of 5‐methoxytryptophol were increased in the pineal glands of the exposed groups when compared to shamexposed controls. An alteration was also observed in serotonin‐N‐acetyl transferase activity, with lower levels measured in pineal glands from exposed animals.
Growth and metabolism of rodents exposed to 60‐Hz electric fields
Authors: Hilton D. I. , Phillips R. D. 
Published: February 2006

AbstractThere have been a number of reports in the literature concerning growth‐related changes in various animal species exposed to high‐strength electric fields. Many of the laboratories reporting such effects have not documented and controlled for the secondary factors that are associated with generating high‐strength electric fields (ie, corona, ozone, harmonic distortion, cage vibration, spark discharge). We have designed an exposure system in which we eliminated or minimized these secondary factors, therefore enabling us to examine only the effects of electric fields per se. Sprague‐Dawley rats and Swiss‐Webster mice were exposed to 60‐Hz electric fields at kV/m for up to four months. In 17 individual experiments, we found a greater number of experiments in which the exposed rats had lower body weights than controls. This trend was not evident in data obtained from 14 individual mouse experiments. In more exhaustive growth studies, we found no significant differences in body weights, organ weights, or O2 consumption between exposed and sham‐exposed controls. Our failure to detect any major changes in growth was probably the result of eliminating or minimizing the secondary factors associated with electric field exposure.
Temporal variation of the static electric field inside an animal cage
Authors: Shigemitsu Tsukasa , Tsuchida Yoshikazu , Nishiyama Fumihiko , Matsumoto Goro , Nakamura Hiroshi , Shimizu Koichi 
Published: February 2006

AbstractThe temporal variation of a static electric field inside an animal cage was investigated with a newly developed small, simple field meter. The field inside the cage was found to be highly dependent on the surface conductivity of the dielectric material. As the surface of the cage became dirty because of animal occupancy, the static electric field inside it became considerably smaller from the moment the field was turned on. Clean cages also modified the static electric field inside them, the field decaying from an initial to a much lower value over several hours. The mechanism of field attenuation for both cases is surface leakage. Surface leakage for a clean cage takes place much more slowly than for a dirty cage. This was confirmed by measuring DC insulation resistance. To examine this phenomenon further, the field in a metal cage with high electrical conductivity was measured. The static electric field inside the metal cage was also found to be reduced. An improved cage design that avoids these problems, is suggested for the study of the biologic effects of static electric fields.
Power‐frequency electric fields averaged over the body surfaces of grounded humans and animals
Authors: Kaune William T. 
Published: February 2006

AbstractCalculated electric‐field strengths averaged over the body surfaces of grounded humans, swine, rats, horses, and cattle exposed to vertical, uniform, power‐frequency electric fields are presented. To produce the same average fields over the body surfaces of grounded animals, as that experienced by a grounded man exposed to an unperturbed vertical field of 10 kV/m, the following unperturbed fields are required: swine, 19 kV/m; rat, 37 kV/m; horse, 18 kV/m; cow, 18 kV/m.
The dielectric method of investigating bound water in biological material: An appraisal of the technique
Authors: Grant E. H. 
Published: February 2006

AbstractThree independent dielectric methods for the measurement of water of hydration (bound water) in a biological material are described and discussed comparatively. For well‐defined aqueous solutions of biological molecules, hydration can be obtained from direct observations made on the δ dispersion or from measurement of the dielectric values of the β dispersion. For whole tissue, however, neither of these two methods is applicable, and to deduce the hydration, it is necessary to use the third technique in which the volume of the hydrated biological particle is obtained by measuring the effect of it on the known dielectric properties of pure water. The hydration can then be calculated by deducting the volume of the anhydrous particle from the experimentally determined volume of the hydrated particle. Owing to possible systemmatic errors the uncertainty in the absolute hydration value associated with this technique is rather larger than that obtained with the other two dielectric methods. For studying the differences between hydration in similar tissues, however, this objection disappears.
Dielectric probe of the electric‐field‐sensitive peptide alamethicin
Authors: Schwarz G. , Savko P. 
Published: February 2006

AbstractDielectric constant and loss of alamethicin in solvents of various degrees of lipophilicity (namely mixtures of n‐octanol and dioxane) have been measured at frequencies from 5 kHz to 50 MHz. By means of a conventional Cole‐Cole approach, dielectric properties were evaluated to obtain information about the structural and dipolar properties of the peptide in view of its function as a voltage‐dependent pore former in membranes. The results for a pure octanol solvent (together with an apparent molecular weight determined by ultracentrifugation) indicate the existence of primarily monomeric particles of quite elongated shape and of comparatively high dipole moment. Adding dioxane was found to yield considerable aggregation and a decrease of polarity.
Electromagnetic absorption in an inhomogeneous model of man for realistic exposure conditions
Authors: Gandhi O. P. 
Published: February 2006

AbstractThe advances made in quantifying electromagnetic absorption and its distribution for various exposure profiles are described. The conditions that have been studied extensively are: free‐space irradiation and its variations, such as the presence of ground and reflecting surfaces and other humans in close proximity. Using an inhomogeneous block model of man, work has recently been extended to leakage‐type near‐fields such as those from RF heat sealers and other electronic equipment. Projections are made for the extension of this work to evaluate coupled near‐fields, design of multielement near‐field applicators to obtain physician‐prescribed uniform or nonuniform rates of regional heating, and for the inverse scattering problem necessary for electromagnetic biomedical imaging. Accurate information about the dielectric properties of various tissues becomes increasingly important for proper inhomogeneous modeling of man.
Active electric properties of cardiac muscle
Authors: Geselowitz David B. , Miller W. T. 
Published: February 2006

AbstractA model of electrical activity in the heart has been developed that treats the intracellular domain and the extracellular domain as electrical syncytia with anisotropic resistivities (bi‐syncytial model). At the microscopic level, propagation is assumed to proceed primarily along the axes of individual cells. Considerations at the macroscopic level relate the transmembrane current to the intracellular and extracellular resistivity and the transmembrane potential. The result is a relationship between instantaneous extracellular potentials and cardiac action potentials.
Analysis of inphase interaction pattern in EEG
Authors: Meleis Hanafy , Takashima Shiro , Harner Richard N. 
Published: February 2006

AbstractInphase interactions among EEG signals recorded using eight electrodes were investigated. The inphase interaction parameters are presented in two ways: (1) matrix form in which the number of inphase interactions are tabulated; and (2) histogram in which the number of inphase interactions are plotted pair‐wise between two sites as a function of phase delays in milliseconds. The highest number of interactions occurs between 0 and 8 ms in normal brains.The values of interaction parameters are enhanced by various activities. For example, inphase interaction parameters increase in the motor area in the right hemisphere if the EEG is recorded during repeated left fist clenching. Inphase interactions are drastically altered by the presence of a tumor. We studied the inphase interactions of the EEG of a patient having an occipital tumor. The interaction parameters are greatly diminished in this area, indicating a severe impairment of neuronal communications between both hemispheres in the occipital region.The confidence limits of the changes in inphase interaction parameters during fist clenching are tested statistically using the Student's t test. The test shows that the interaction parameters increase, in general, with 1–5% confidence limits in respective cortex areas as a result of fist clenching.
Biological effects of low‐temporal, average‐intensity, pulsed ultrasound
Authors: Carstensen Edwin L. 
Published: February 2006

AbstractStudies with both plant and animal tissues show that, when the tissues contain micron‐sized, stabilized gas bodies, pulsed ultrasound can produce damage at very low time‐averaged intensities. However, it is the temporal peak intensity rather than the time‐averaged intensity that is closely correlated with the effects observed. The data suggest that there may be thresholds for damage at peak intensities within an order of magnitude of 10 W/cm2.
Wideband acoustic energy studies of pulmonary airways
Authors: Jacobs John E. 
Published: February 2006

AbstractThe impulse response of the pulmonary system has been measured by exciting the system with wideband acoustic noise introduced through the mouth. The transmitted sound is detected using microphones placed on the patient's back at appropriate locations. A specially designed analog correlator is used to obtain the impulse response of the pulmonary system through cross‐correlation techniques. Uniquely characteristic responses have been obtained from smoking and nonsmoking patient groups.
Investigation of the effects of continuous‐wave, pulse‐ and amplitude‐modulated microwaves on single excitable cells of chara corallina
Authors: Liu Li‐Ming , Garber Francine , Cleary Stephen F. 
Published: February 2006

AbstractSingle internodal excitable cells of Chara corallina were exposed to CW, pulse‐modulated and sinusoidally modulated S‐band microwave fields in a temperature‐controled waveguide exposure chamber. All electrical measurements were made external to the waveguide (ie, under no impressed microwave field). The dependent variables measured before, during, and after exposure to the S‐band microwave fields included: resting potential, amplitude of the action potential, rise and decay time of the action potential, conduction velocity, and excitability. Cells maintained at 22 ± 0.1 °C during exposure showed no consistent or statistically significant microwave‐dependent alterations in any of the dependent variables.