Radio Waves

There is considerable controversy surrounding the biological effects of radiofrequency (RF) fields, as emitted by mobile phones. Previous work from our laboratory has shown no effect related to the exposure of 1.9 GHz pulse-modulated RF fields on the expression of 22 000 genes in a human glioblastoma-derived cell-line (U87MG) at 6 h following a 4 h RF field exposure period. As a follow-up to this study, we have now examined the effect of RF field exposure on the possible expression of late onset genes in U87MG cells after a 24 h RF exposure period. In addition, a human monocyte-derived cell-line (Mono-Mac-6, MM6) was exposed to intermittent (5 min ON, 10 min OFF) RF fields for 6 h and then gene expression was assessed immediately after exposure and at 18 h postexposure. Both cell lines were exposed to 1.9 GHz pulse-modulated RF fields for 6 or 24 h at specific absorption rates (SARs) of 0.1-10.0 W/kg. In support of our previous results, we found no evidence that nonthermal RF field exposure could alter gene expression in either cultured U87MG or MM6 cells, relative to nonirradiated control groups. However, exposure of both cell-lines to heat-shock conditions (437C for 1 h) caused an alteration in the expression of a number of well-characterized heat-shock proteins.

This paper describes a heterogeneous phantom that mimics a human thigh with a deep seated tumor, for the purpose of studying the performance of radiofrequency (RF) heating equipment and non-invasive temperature monitoring with magnetic resonance imaging (MRI). The heterogeneous cylindrical phantom was constructed with an outer fat layer surrounding an inner core of phantom material mimicking muscle, tumor and marrow-filled bone. The component materials were formulated to have dielectric and thermal properties similar to human tissues. The dielectric properties of the tissue-mimicking phantom materials were measured with a microwave vector network analyzer and impedance probe over the frequency range of 80 -500 MHz and at temperatures of 24°C, 37°C, and 45°C. The specific heat values of the component materials were measured using a differential scanning calorimeter over the temperature range of 15 -55°C. The thermal conductivity value was obtained from fitting the curves obtained from one-dimensional heat transfer measurement. The phantom was used to verify the operation of a cylindrical 4antenna annular phased array extremity applicator (140 MHz), by examining the proton resonance frequency shift (PRFS) thermal imaging patterns for various magnitude/phase settings (including settings to focus heating in tumor). For muscle and tumor materials, MR imaging was also used to measure T1/T2* values (1.5 Tesla) and to obtain the slope of the PRFS phase change vs. temperature change curve. The dielectric and thermal properties of the phantom materials were in close agreement to well-accepted published results for human tissues. The phantom was able to successfully demonstrate satisfactory operation of the tested heating equipment. The MRImeasured thermal distributions matched the expected patterns for various magnitude/phase settings of the applicator, allowing the phantom to be used as a quality assurance tool. Importantly, the material formulations for the various tissue types may be used to construct customized phantoms that are tailored for different anatomical sites.

Radiofrequency surgery is a widely used modern technique for submucosal volume reduction of the tonsils. So far there is very limited information on morphologic changes in the human tonsils after radiofrequency surgery. We performed histopathological study of tonsillectomy specimens after previous bipolar radiofrequency induced thermotherapy (RFITT). A total of 83 patients underwent bipolar RFITT for hypertrophy of palatine tonsils. Tonsil volume reduction was measured by 3D ultrasonography. Five patients subsequently underwent tonsillectomy. Profound histopathological examination was performed to determine the effect of RFITT on tonsillar architecture. All tonsillectomy specimens showed the intact epithelium, intact germinal centers, normal vascularization, and no evidence of increased fibrosis. No microscopic morphological changes in tonsillectomy specimens after bipolar RFITT were observed. RFITT is an effective submucosal volume reduction procedure for treatment of hypertrophic palatine tonsils with no destructive effect on microscopic tonsillar architecture and hence most probably no functional adverse effect.

Exposure to electromagnetic fields (EMFs) released from mobile phones has been evident to affect individuals' health, indicating that almost all individuals in the globe will be affected in case health is influenced by mobile phones. Recently, using cellular phones has provoked several queries about their safety, since operators are exposed to ultra-high frequency EMFs. The effect on individuals' bodies is mainly dependent on the EMFs exposure's power and frequency. Besides, the potential health results of weak, high-frequency EMFs and biological effects have been increasingly interested in. Various system diseases have strong association with EMFs, including mobile phones, as reported by some studies conducted on the association of magnetic fields (MFs) with reproduction, cancer or neurobehavioral reactions. Since clinical and/or electrical appliances have been widely used, there is nowadays a growing increase in studies investigating the EMFs effect on the biological system. Some of which suggested EMFs exposure's adverse effects. Similar to technological advances, using EMFs is of a growing increase, resulting in higher levels of everyday EMFs exposure than those which naturally exist. The continuous increase in using cell phones with their effects produced by the exposure to EMFs has provoked another query of their potential side effect on the living organism and has raised various measures of concerns. The social life of humans has been dramatically changed after the discovery of electricity. A huge number of electronic devices has been generated due to the rapidly industrial and economic developments and improvements. Currently, exposure to EMFs from different electronic devices, including computers, phones, power lines, radios, etc. is inevitable in everyday lives. Nonetheless, the most individuals' awareness and knowledge of the harmful effect of EMFs on their health emitted by such devices are poor. In mobile-phone telecommunications, radio waves of 900-MHz as well as 1800-MHz are frequently used. Radiation technologies such as mobile phone, microwave and radiofrequency have intensively used in the recent decades with the growing demand of electronic devices. X band radar frequency between 8-12 GHz is widely used in industrial and scientific devices and domestic, military, and medical applications. Irradiation emitted by radar system into the environment may pose a health risk to the workers in certain occupations. Since mobile phones and military radar devices are placed in close proximity to the genitals, the reproductive system is then absorbed high radiation rates when compared with other organs. Several studies have reported the detrimental EMFs effect on testis and seminal factors, such as morphology, motility, and concentration. Other studies investigated the cytotoxic effects of EMFs exposure on spermatogonia, spermatogenesis, induced apoptosis, decreased testicular biopsy score, degeneration of germ cells. Whereas, other studies suggested that EMFs do not impact the male reproductive system. Similar experiments were conducted to investigate the EMFs effects on the kidney structure. They were found that the exposure EMF scan cause pathological effects in kidney tissue

The effect of exposing magnetic fields (MFs) with low frequency on human cardiovascular parameters are still unidentified. As a predictor of specific cardiovascular pathologies, estimating the exposure of employees' workplace with dosimeters by changed variability of heart rates is performed in epidemiological studies. Besides, microcirculatory factors such as blood pressure, variability of heart rates or heart rates are concentrated on by laboratory studies. Studies about microcirculatory system's responses to exposing low frequencymagnetic fields are sparse. In the international existing re-evaluation contexts of exposure guidelines, tackling such issues is important for further studies regarding low frequencymagnetic fields, international exposure guideline re-evaluation. In these studies, the potential negative and positive influences of low frequencymagnetic fields and the detections and characterizations of their induced subtle physiological changes should be addressed. The investigation of the micro-and macro-circulatory relationships and the utalization of laboratory geomagnetic shielding are recommended for futher studies. The micro-and macro-circulation, lymph vascular system, and heart are included in the cardiovascular system. Although the cardiovascular system's mechanics and characteristics had a wide discussion in literature which is beyond this paper' scope, a consise description of this system was conducted for the facilitatation of understanding the effects of exposing low frequency magnetic fields on human cardiovascular parameters.

Introduction: Osteoarthritis of the knee is a common cause of chronic pain, functional limitation, and poor quality of life among elderly individuals. Conventional treatments such as analgesics, physiotherapy, and intra-articular injections often provide only temporary relief. Hyaluronic acid injection improves joint lubrication and pain control, though its effectiveness may be short-lived. Ultrasound-guided pulsed radiofrequency (PRF) of genicular nerves is a minimally invasive intervention that modulates nociceptive pathways without causing permanent neural damage. Comparative evidence between these modalities remains limited.
Aim: To compare the effectiveness of ultrasound-guided genicular nerve pulsed radiofrequency and intra-articular hyaluronic acid injection in relieving pain and improving function in chronic osteoarthritis knee pain.
Methods: This prospective randomized study will include adult patients with chronic osteoarthritis knee pain refractory to conservative treatment. Participants will be randomly allocated into two groups:
Group A will receive ultrasound-guided pulsed radiofrequency of the superior medial, superior lateral, and inferior medial genicular nerves, while Group B will receive ultrasound-guided intra-articular hyaluronic acid injection. Pain intensity will be assessed using the Visual Analogue Scale (VAS) and functional outcome using the WOMAC score at baseline, 1 week, 1 month, 3 months, and 6 months after intervention. Analgesic requirement, patient satisfaction, and procedure-related complications will also be evaluated.
Results: Genicular nerve pulsed radiofrequency is expected to provide longer-lasting pain relief, improved functional outcomes, and reduced analgesic consumption compared to hyaluronic acid injection.

Background: Intima-media thickness of the common carotid artery (CCA-IMT) is a validated marker of systemic atherosclerosis process. The aim of this study was to evaluate the association between coronary artery disease (CAD), left ventricular hypertrophy (LVH) and CCA-IMT, assessed by Radio Frequency-Quality Intima Media Thickness ( RF QIMT) method, the next generation of IMT real-time measurement, based on the direct analysis of the radiofrequency signal and endowed with high accuracy and reproducibility in early detection of arterial wall thickness. Methods: 115 patients (76 men, mean age: 65.1 ± 12 years) referred to our department and shown significant (≥ 70% luminal obstruction) stenosis at least in one major epicardial coronary artery were studied. Coronary angiograms were divided for severity and extent of the disease: 79 patients (69%) had one, 24 patients (21%) two, 12 patients (10%) three major epicardial coronary arteries with ≥ 70% stenosis. All patients underwent echocardiography and carotid ultrasound examination, assessed by RF. Results: Dividing RF QIMT data in tertiles, dyslipidaemia (31 patients with IMT ≥ 1.20 mm vs 16 with IMT = 0.91-1.19 vs 25 with IMT ≤ 0.9, p = 0.004), LVMI (153.5 ± 20.6 g/m 2 in IMT ≥ 1.20 mm vs 131.2 ± 8.4 g/m 2 in IMT = 0.91-1.19 mm vs 114.3 ± 11.1 g/m 2 in IMT ≤ 0.9 mm, P < 0.001) and number of high stenosed coronary arteries (IMT ≥ 1.20 mm population more often showed three vessel diseases than IMT ≤ 0.90 mm one, P < 0.001) seemed to be significantly related to CCA-IMT increases. Furthermore, LVMI is positively related to IMT (r = 0.91; P < 0.001). In a multivariate regression model (R 2 = 0.88), RF QIMT remained significantly associated with the dyslipidemia (regression coefficient ± standard error [SE]: 0.057 ± 0.023; p = 0.017), LVMI (regression coefficient ± SE: 0.01 ± 0.001; P < 0.0001) and number of damaged coronaries (regression coefficient ± SE: 0.0174 ± 0.028; P < 0.0001). Conclusions: RF QIMT is a sophisticated method for carotid ultrasound evaluation. Its evaluation in patients with at least one important major epicardial coronary vessel stenosis would help the accuracy in the general assessment of the number of coronary lesions in these patients.

Reports of incidents such as those in Havana (2016) and elsewhere have drawn comparisons to documented microwave and RF effects, including auditory perception, pain, and vestibular disruption. My hypothesis suggests remote RF transmission via ethernet to radar as a possible mechanism, given that close-range or wearable sources such as back packs would affect the operator as well.

This article is related to the proposed hypothesis and experimental data regarding the ability of defined polar polymer compound (MRET polymer) applied to RF phones to increase the dielectric permittivity of water based solutions and to reduce the SAR (Specific Absorption Rate) values inside the &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;phantom head&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; filled with the jelly simulating muscle and brain tissues. Due to the high organizational state of fractal structures of MRET polymer compounds and the phenomenon of piezoelectricity, this polymer generates specific subtle, low frequency, non-coherent electromagnetic oscillations (optimal random field) that can affect the hydrogen lattice of the molecular structure of water and subsequently modify the electrodynamic properties of water. The increase of dielectric permittivity of water finally leads to the reduction of the absorption rate of the electromagnetic field by living tissue. The reduction of SAR values is confirmed by the research conducted in June - July of 2006 at RF Exposure Laboratory in Escondido, California. This test also confirmed that the application of MRET polymer to RF phones does not significantly affect the air measurements of RF phone signals, and subsequently does not lead to any significant distortion of transmitted RF signals.

Both microwave ablation (MWA) and radiofrequency ablation (RFA) are commonly employed local ablation techniques for malignant liver tumors. However, comparative data on long-term results between these two techniques is scarce in the literature. This is a retrospective comparative study between MWA and RFA for hepatocellular carcinoma (HCC) using surgical approach. The MWA group consisted of 26 patients while the RFA group consisted of 47 case-matched patients. The two groups were comparable, except patients were older and their platelet count was lower in the MWA group. The median follow-up period was 47.5 months in MWA group and 52.9 months in RFA group (p = 0.322). There was no difference in 5-year overall survival (MWA 73.1%, RFA 46.3%, p = 0.082) and 5-year disease free survival (MWA 13.8%, RFA 14.6%, p = 0.736). When a subgroup analysis of tumors ≥ 3.5 cm was performed, there were 16 patients in the MWA group and 21 patients in the RFA group, the 5-year overall and disease-free...

We have previously presented a histopathological grading scheme for thermal damage in normal porcine adipose and skeletal muscle tissues. Here we have used this scheme to assess the heat sensitivity of these tissues, and evaluate the protective benefit of thermotolerance as induced by a prior thermal exposure. Tissues were exposed to temperatures rang ing from 40-50°for 30 min. Half of all sites also received a thermal exposure of 41.0-43.0°4 hr earlier. Biopsies for histological evaluation were obtained at 18 to 24 hr ("acute") and at 28 to 31 days ("chronic") following treatment. Only mild acute injury was seen in the early samples, following either single or double heat exposures, at all temperature levels. Minimal chronic damage was also seen in the late samples following single exposures of 45°or less. Higher single exposures caused im portant chronic lesions, the severity of which was dose depend ent. Regions that had received the earlier conditioning thermal exposure showed a significant protection against the subsequent thermal exposure. In such regions, mean (chronic) pathology scores were reduced by 76 to 86% over the temperature range 45-48°. The degree of acute damage failed to predict the degree of chronic damage. Overall, induction of thermotolerance pro vided an advantage of 2°or more in normal tissue protection.

We have plotted data from a number of studies on the range of radiofrequency (RF) field levels associated with a variety of environmental and occupational sources. Field intensity is shown in units of volts/meter (V/m) for electric field strength and amps/meter (A/m) for magnetic field strength. Duty factors, modulation frequencies, and modulation indices are also reported for some sources. This paper is organized into seven sections, each cataloging sources into appropriate RF frequency bands from very-low frequency (VLF) to super-high frequency (SHF), and covers frequencies from 10 kHz to 30 GHz. Sources included in this summary are the following: Coast Guard navigational transmitters, a Navy VLF transmitter, computer visual display terminals (VDTs), induction stoves or range tops, industrial induction and dielectric heaters, radio and television broadcast transmitters, amateur and citizens band (CB) transmitters, medical diathermy and electrosurgical units, mobile and handheld transmitters, cordless and cellular telephones, microwave ovens, microwave terrestrial relay and satellite uplinks, and police, air traffic, and aircraft onboard radars. For the sources included in this summary, the strongest fields are found near industrial induction and dielectric heaters, and close to the radiating elements or transmitter leads of high power antenna systems. Handheld transmitters can produce near fields of about 500 V/m at the antenna. Fields in the general urban environment are principally associated with radio and TV broadcast services and measure about 0.1 V/m root-meansquare (rms). Peak fields from air traffic radars sampled in one urban environment were about 10 V/m, 300 times greater than the rms value of 0.03 V/m when the duty factor associated with antenna rotation and pulsing are factored in.

The Global System for Mobile Communications (GSM) services like General Packet Radio Service (GPRS) and Short Message Service (SMS) have proven to be logical and cost effective techniques for wireless data acquisition systems from remote locations. A communication protocol that facilitates remote data collection using SMS has been successfully applied to acquire data from remote locations. In this study, we have designed a prototype circuit using PIC microcontroller and interfaced this with our newly fabricated ZnO nanotubes based glucose nanosensor fabricated on gold coated glass substrate using low temperature aqueous chemical method. Such applications can reduce the health care costs and provide caregivers and Doctors to monitor and support to their patients from a remote location in case of emergency.

The aim of this study was to investigate if age and body mass of humans have an impact on the DNA-damaging properties of high-frequency mobile phone-specific electromagnetic fields (HF-EMF, 1950 MHz, universal mobile telecommunications system, UMTS signal) and if this form of radiation has an impact on the genotoxic effects of occupationally relevant exposures. Pooled peripheral blood mononuclear cells (PBMC) from three groups [young normal weight, young obese (YO), and older age normal weight individuals] were exposed to different doses of HF-EMF (0.25, 0.5, and 1.0 W/kg specific absorption rate—SAR) and simultaneously or sequentially to different chemicals which cause DNA damage (CrO3, NiCl2, benzo[a]pyrene diol epoxide—BPDE, and 4-nitroquinoline 1-oxide—4NQO) via different molecular mechanisms. We found no difference in regard to the background values in the three groups but a significant increase of DNA damage (81% without and 36% with serum) in cells from old participants after...

One of the most crucial magnetic resonance (MR) safety concerns is related to excessive heating of metallic implants by the radio frequency (RF) magnetic field. In this study, heating by the MR imaging (MRI) RF magnetic field of bare and insulated wires was evaluated to model the heating of medical lead wires. Currents induced in the wire were calculated using the method of moments. The electric field in the tissue surrounding the wire was calculated to determine the power deposition. From the power, the temperature rise was calculated using the bioheat equation. For bare wires, the calculated and maximal temperature rise, which is about 28 degrees C, occurred for a length of 20 cm. For lengths exceeding 20 cm, temperature rises for the insulated wires were greater, and the resonance length exceeded 40 cm.114139sciescopu

Nocturnal respiration rate parameters were collected from 20 COPD subjects over an 8 week period, to determine if changes in respiration rate were associated with exacerbations of COPD. These subjects were primarily GOLD Class 2 to 4, and had been recently discharged from hospital following a recent exacerbation. The respiration rates were collected using a non-contact radio-frequency biomotion sensor which senses respiratory effort and body movement using a short-range radio-frequency sensor. An adaptive notch filter was applied to the measured signal to determine respiratory rate over rolling 15 s segments. The accuracy of the algorithm was initially verified using ten manually-scored 15 min segments of respiration extracted from overnight polysomnograms. The calculated respiration rates were within 1 breath min -1 for >98% of the estimates. For the 20 subjects monitored, 11 experienced one or more subsequent exacerbation of COPD (ECOPD) events during the 8 week monitoring period (19 events total). Analysis of the data revealed a significant increase in nocturnal respiration rate (e.g. >2 breath min -1 ) prior to many ECOPD events. Using a simple classifier of a change of 1 breath min -1 in the