SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
EEG records were obtained from 9 blinds under several types of stimulation. The occipital alpha rhythm was much reduced in them, whereas small parietal activity in the alpha range was often observed in the later blind. Any type of stimulation did not produce beta rhythm, but accelerated the background alpha rhythm.
Transient current density J(t) induced in the body of a person exposed to a single magnetic pulse of arbitrary shape or to a magnetic jump is filtered by a convolution integral containing in its kernel the frequency and phase dependence of the basic limit value adopted in a way similar to that used for reference values in the International Commission on Non-lonising Radiation Protection statement. From the obtained time-dependent dimensionless impact function W(J)(t) can immediately be determined whether the exposure to the analysed single event complies with the basic limit. For very slowly varying field, the integral kernel is extended to include the softened ICNIRP basic limit for frequencies lower than 4 Hz.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
There is a widespread public perception that exposure to electricity is linked to cancer. The public concern stems largely from epidemiological studies which appear to show a relationship between cancer incidence and exposure to power-frequency electromagnetic fields. This review will discuss the biophysics of power-frequency electromagnetic fields as it relates to biological effects, summarize the current state of the cancer epidemiology, and then concentrate on the laboratory studies that are relevant to addressing the possibility that power-frequency fields are carcinogenic. Review of the epidemiological evidence shows that the association between exposure to power-frequency fields and cancer is weak and inconsistent, and generally fails to show a dose-response relationship. The laboratory studies of power-frequency fields show little evidence of the type of effects on cells or animals that point towards power-frequency fields causing or contributing to cancer. Finally, from what is known about the biophysics of power-frequency fields, there is no reason to even suspect that they would cause or contribute to cancer. Application of "Hill's criteria" to epidemiological and laboratory studies shows that the evidence for a causal association between exposure to power-frequency fields and the incidence of cancer is weak.
Melanosome is a cellular organelle that is composed of a melanosomal matrix and a brown biochrome, melanin which is formed by tyrosine-tyrosinase reactions. The melanosome is formed within the melanocyte and transferred to the surrounding keratinocytes through dendritic processes. Human skin color is related to the number, size, type and distribution of melanosomes, and the major role of melanosomes is to prevent skin from injurious nonionizing ultraviolet radiation. Controlled NaOH hydrolysis and centrifugation of human hair make it possible to isolate large amounts of melanosomes which are synthesized within the follicular melanocytes and transferred to hair matrix cells. In this study, the sun protection factors of topically applied melanosomes isolated from human hair were evaluated using ultraviolet B phototesting. Topically applied melanosomes increased the minimal erythemal doses. And the sun protection factors of each 50% and 25% melanosomal preparation were 12.3 +/- 5.5 and 3.1 +/- 1.3 respectively, and these ultraviolet B protection effects showed statistically significant differences from 10%, 5% and 1% melanosomal preparations and vehicle. Form these results, the dose-related photoprotective role of melanosomes was confirmed.
OBJECTIVES: The aim of this study was to explore the possible influence of radiofrequency (RF) radiation exposure on human brain function. METHODS: The electroencephalographic (EEG) activity of 19 volunteers was quantitatively analyzed. Ten of the subjects were men (28-48 years of age) and 9 were women (32-57 years of age). The sources of exposure were 5 different cellular phones (analogue and digital models) operating at a frequency of 900 MHz or 1800 MHz. The EEG activity was recorded in an awake, closed-eyes situation. Six 30-minute experiments, including 1 sham exposure, were made for each subject. The duration of a real exposure phase was 20 minutes. RESULTS: Exposure to one of the phones caused a statistically significant change in the absolute power at the delta band of the EEG recording. However, no difference was seen in the relative power of the same band, and no changes occurred during exposure to other phones at any frequency bands. CONCLUSIONS: The findings of this study suggest that exposure to radiofrequency fields emitted by cellular phones has no abnormal effects on human EEG activity. The observed difference in 1 parameter was probably caused by statistical chance.
Pulsed light is a non-thermal sterilization method that uses brief intense pulses or flashes of white light to kill micro-organisms. This article discusses tests performed on blow/fill/seal containers. The results suggest that pulsed light has potential as a terminal sterilization method for filled and sealed transmissive products and packages. It also examines the effectiveness of pulsed light in eliminating water-borne pathogenic organisms.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Intensive use of various emitters of radiofrequency electromagnetic fields is a potential health hazard both for workers and general population. Thus, improved hygienic regulation and control of nonionizing electromagnetic radiation becomes very important for prophylactics. Hygienic regulation of radiofrequency electromagnetic fields is based on elimination of their influence on human health. Incomplete knowledge of biologic mechanisms underlying influence of low-intensity radiofrequency electromagnetic fields is a serious obstacle to further improvement of hygienic regulation. Special attention should be paid on clinical, physiologic and epidemiologic research aimed to study long-term effects and influence of the stated fields on general morbidity.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
This article tackles the problem of primary reception of millimeter waves by live systems. It also discusses the physical mechanisms of low-intensity millimeter-wave effect on live systems. It is postulated that water molecules of the skin can be the primary molecular receptors that transfer the energy of external radiation to primary physiological targets in the exposure site (a "water-primary target" model). The effect of solute molecules on the absorption of millimeter-wave radiation (lambda= 2, 5.84, and 7.12 mm) by aqueous solutions was studied on alpha-amino acids. Various mechanisms are outlined of intermolecular interaction of alpha-amino acids in aqueous solutions, such as the raised absorption of water molecules in solute hydration shells (negative hydration) and the decreased absorption of water molecules in solute hydration shells (positive hydrophilic and hydrophobic hydration).
Explore the source record for details and available documents.
Future space travellers and settlers will be exposed to a variety of electromagnetic fields (EMFs). Extrinsic sources will include solar and stellar fluxes, planetary fluxes, and supernovae. Intrinsic sources may include fusion and ion engines, EMFs from electrical equipment, radar, lighting, superconduction energy storage systems, magnetic bearings on gyroscopic control and orientation systems, and magnetic rail microprobe launch systems. Communication sources may include radio and microwave frequencies, and laser generating systems. Magnetic fields may also be used for deflection of radiation. There is also a loss of the normal Geomagnetic field (GMF) which includes static, alternating, and time-varying components. This paper reviews exposure limits and the biological effects of EMFs, and evidence for an electromagnetic sense organ and a relationship between man and the Geomagnetic field.
The work is the first attempt to study nuclear dualism of ciliates with ultraviolet microbeam (UV-beam), which was not applied earlier for these purposes. The special advantage of the UV-beam is that it allow to inactivate selectively of the particular elements of nuclear apparatus of living ciliates is to observe consequences of operation on distant descendants of irradiated cell. On Paramecium caudatum the ways of UV-beam have been devised specifically. The original rotocompression chamber was employed for immobilization of cell in space of irradiation. The effective UV-doses were selected, the relative resistance of cytoplasm, macro-, micronucleus (Mi), and symbiotic bacteria of Mi -- omega particles -- was detected. The "pure" and infected cells were irradiated, in some different variants. The effect of UV-beam depends on dose and consists in a reduction the effectiveness of cell cloning, the loss of omega-particles from Mi, the appearance of the cells with 2--3 Mi, and, possibly, of amicronucleate cells. The injuries due to UV-beam are restored by photoreactivation of visible light.