Level of Radiofrequency (RF) Radiations from GSM Base Stations ...

African Journals Online (AJOL)

Levels of radiofrequency radiations around two global systems for mobile communication (GSM) base stations located in the vicinity of a residential quarter and workplace complex were measured. The effects of the radiofrequency radiations on albino mice placed in exposure cages and located around the base stations ...

Radiofrequency radiation

International Nuclear Information System (INIS)

Elder, J.A.; Czerski, P.A.; Stuchly, M.A.; Mild, K.H.; Sheppard, A.R.

1989-01-01

High-level radiofrequency radiation is a source of thermal energy that carries all of the known implications of heating for biological systems, including burns, temporary and permanent changes in reproduction, cataracts, and death. In general, no changes in chromosomes, DNA or the reproductive potential of animals exposed to RF radiation have been reported in the absence of significant rises in temperature, though there are limited data on DNA and chromosomal changes at non-thermal levels. Human data are currently limited and do not provide adequate information about the relationship between prolonged low-level RF radiation exposure and increased mortality or morbidity, including cancer incidence. In epidemiological studies and clinical reports of RF effects in man, the problems of quantification are numerous and include uncertainties about ''dose'', health effects, latent periods, dose-response relationships, and interactions with other physical or chemical agents. 228 refs, 6 figs, 2 tabs

Eye examinations of laser and radiofrequency radiation workers

International Nuclear Information System (INIS)

Hocking, B.

1988-01-01

There are a growing number of uses of lasers and radiofrequency radiation in industry. Because these radiations may lead to various ocular effects, examinations of the eye are required for laser and radiofrequency workers as part of safe working practices. Various issues concerning these examinations are raised for discussion including: handling personal data, placement criteria, data collection, quality control, control data, the load on service providers, and costs

Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model.

Science.gov (United States)

Mortazavi, S M J; Rahimi, S; Talebi, A; Soleimani, A; Rafati, A

2015-09-01

The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. In this study that was aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted by a GSM mobile phone on the pattern of contraction in frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz), pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

Looking at the other side of the coin: the search for possible biopositive cognitive effects of the exposure to 900 MHz GSM mobile phone radiofrequency radiation.

Science.gov (United States)

Mortazavi, Seyed Ali Reza; Tavakkoli-Golpayegani, Ali; Haghani, Masoud; Mortazavi, Seyed Mohammad Javad

2014-01-01

Although exposure to electromagnetic radiation in radiofrequency range has caused a great deal of concern globally, radiofrequency radiation has many critical applications in both telecommunication and non-communication fields. The induction of adaptive response phenomena by exposure to radiofrequency radiation as either increased resistance to a subsequent dose of ionizing radiation or resistance to a bacterial infection has been reported recently. Interestingly, the potential beneficial effects of mobile phone radiofrequency radiation are not only limited to the induction of adaptive phenomena. It has previously been indicated that the visual reaction time of university students significantly decreased after a 10 min exposure to radiofrequency radiation emitted by a mobile phone. Furthermore, it has been revealed that occupational exposures to radar radiations decreased the reaction time in radar workers. Based on these findings, it can be hypothesized that in special circumstances, these exposures might lead to a better response of humans to different hazards. Other investigators have also provided evidence that confirms the induction of RF-induced cognitive benefits. Furthermore, some recent reports have indicated that RF radiation may play a role in protecting against cognitive impairment in Alzheimer's disease. In this light, a challenging issue will arise if there are other RF-induced stimulating effects. It is also challenging to explore the potential applications of these effects. Further research may shed light on dark areas of the health effects of short and long-term human exposure to radiofrequency radiation.

21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation, including...

Survey of the Effects of Exposure to 900 MHz Radiofrequency Radiation Emitted by a GSM Mobile Phone on the Pattern of Muscle Contractions in an Animal Model

Directory of Open Access Journals (Sweden)

Mortazavi S. M. J.

2015-09-01

Full Text Available Background: The rapid development of wireless telecommunication technologies over the past decades, has led to significant changes in the exposure of the general public to electromagnetic fields. Nowadays, people are continuously exposed to different sources of electromagnetic fields such as mobile phones, mobile base stations, cordless phones, Wi-Fi routers, and power lines. Therefore, the last decade witnessed a rapidly growing concern about the possible health effects of exposure to electromagnetic fields emitted by these sources. Materials and Methods: In this study that was aimed at investigating the effects of exposure to radiofrequency (RF radiation emitted by a GSM mobile phone on the pattern of contraction in frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz, pulse height of contractions, the time interval between two subsequent contractions and the latency period were measured. Results: Our findings showed that the pulse height of contractions muscle could be affected by the exposure to electromagnetic fields. Especially, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. Conclusion: These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions

Radiation emitting devices act

International Nuclear Information System (INIS)

1970-01-01

This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

Radiation emitting devices regulations

International Nuclear Information System (INIS)

1970-01-01

The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

Science.gov (United States)

Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

2016-01-01

Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

Effects of radiofrequency exposure emitted from a GSM mobile phone on proliferation, differentiation, and apoptosis of neural stem cells

Science.gov (United States)

Eghlidospour, Mahsa; Ghanbari, Amir

2017-01-01

Due to the importance of neural stem cells (NSCs) in plasticity of the nervous system and treating neurodegenerative diseases, the main goal of this study was to evaluate the effects of radiofrequency radiation emitted from a GSM 900-MHz mobile phone with different exposure duration on proliferation, differentiation and apoptosis of adult murine NSCs in vitro. We used neurosphere assay to evaluate NSCs proliferation, and immunofluorescence assay of neural cell markers to examine NSCs differentiation. We also employed alamarBlue and caspase 3 apoptosis assays to assess harmful effects of mobile phone on NSCs. Our results showed that the number and size of resulting neurospheres and also the percentage of cells differentiated into neurons decreased significantly with increasing exposure duration to GSM 900-MHz radiofrequency (RF)-electromagnetic field (EMF). In contrast, exposure to GSM 900-MHz RF-EMF at different durations did not influence cell viability and apoptosis of NSCs and also their astrocytic differentiation. It is concluded that accumulating dose of GSM 900-MHz RF-EMF might have devastating effects on NSCs proliferation and neurogenesis requiring more causations in terms of using mobile devices. PMID:28713615

Safety assessment of RF and microwave radiation emitted by the mobile telephone base station (MTBS) in Malaysia: experience and challenge

International Nuclear Information System (INIS)

Roha Tukimin; Rozaimah Abd Rahim; Mohamad Amirul Nizam; Mohd Yusof Mohd Ali

2007-01-01

Non-ionising radiation (NIR) is known to be hazardous if the amount received is excessive. It is a fact that NIR, including extremely low frequency (ELF) electromagnetic fields, radiofrequency (RF) and microwave radiation can be found almost everywhere generated by both natural and man-made source. This is due to increase in demand for telecommunication and wireless technology which is become very important and as part of our lives. However, the widespread of the relevant technology contributed more NIR man-made sources exposure to the human. Due to public concern their potential of causing such health hazard, members of public and companies approached and request NIR Group of Nuclear Malaysia to carry out surveys and safety assessments of radiofrequency and microwave radiation emitted by the mobile telephone base station (MTBS) erected near the residential area or installed on the rooftop of the commercial building. Objective of the survey was to assess the presence of radiofrequency and microwave radiation and to identify radiation level which may lead to significant personnel exposure. Findings of the survey was compared to the standard guidelines issued by Malaysian Communication and Multimedia Commission (MCMC) and International Committee on Non-Ionising Radiation Protection (ICNIRP). This paper highlights the works that had been carried out by NIR Group of Nuclear Malaysia from 1997 to 2007. We will share the experience and challenge in carried out the NIR safety assessment at mobile telephone base station. Results of the assessment work will be used to develop non-ionising radiation database for future reference in Malaysia. (Author)

The effect of 2100 MHz radiofrequency radiation of a 3G mobile phone on the parotid gland of rats.

Science.gov (United States)

Aydogan, Filiz; Unlu, Ilhan; Aydin, Emine; Yumusak, Nihat; Devrim, Erdinc; Samim, Ethem Erdal; Ozgur, Elcin; Unsal, Velid; Tomruk, Arin; Ozturk, Goknur Guler; Seyhan, Nesrin

2015-01-01

We aimed to evaluate the effect of 2100 MHz radiofrequency radiation on the parotid gland of rats in short and relatively long terms. Thirty Wistar albino rats were divided into four groups. Groups A and B served as the control groups (for 10 days and 40 days, respectively), and each group included six rats. Groups C and D were composed of nine rats each, and they were the exposure groups. The rats were exposed to 2100 MHz radiofrequency radiation emitted by a generator, simulating a third generation mobile phone for 6 hours/day, 5 days/week, for 10 or 40 days. Following exposure, the rats were sacrificed and parotid glands were removed. Histopathological and biochemical examinations were performed. Although there were no histopathological changes in the control groups except for two animals in group A and three animals in group B, the exposure groups C (10 days) and D (40 days) showed numerous histopathological changes regarding salivary gland damage including acinar epithelial cells, interstitial space, ductal system, vascular system, nucleus, amount of cytoplasm and variations in cell size. The histopathological changes were more prominent in group D compared to group C. There was statistically significant different parameter regarding variation in cell size between the groups B and D (p=0.036). The parotid gland of rats showed numerous histopathological changes after exposure to 2100 MHz radiofrequency radiation, both in the short and relatively long terms. Increased exposure duration led to an increase in the histopathological changes. Copyright © 2015 Elsevier Inc. All rights reserved.

Administrative norms on radiofrequency radiation for occupationally exposed persons

International Nuclear Information System (INIS)

Saxeboel, G.

1982-01-01

The report presents a proposal for administrative norms on radiofrequency (RF) radiation for occupationally exposed persons. The norms establish maximum allowable field exposure in a frequency range from 1 MHz too 300 GHz. (RF)

Explanation for Cancer in Rats, Mice and Humans due to Cell Phone Radiofrequency Radiation

OpenAIRE

Feldman, Bernard J.

2016-01-01

Very recently, the National Toxicology Program reported a correlation between exposure to whole body 900 MHz radiofrequency radiation and cancer in the brains and hearts of Sprague Dawley male rats. This paper proposes the following explanation for these results. The neurons around the rat's brain and heart form closed electrical circuits and, following Faraday's Law, 900 MHz radiofrequency radiation induces 900 MHz electrical currents in these neural circuits. In turn, these 900 MHz currents...

Measurement uncertainty in broadband radiofrequency radiation level measurements

Directory of Open Access Journals (Sweden)

Vulević Branislav D.

2014-01-01

Full Text Available For the evaluation of measurement uncertainty in the measurement of broadband radio frequency radiation, in this paper we propose a new approach based on the experience of the authors of the paper with measurements of radiofrequency electric field levels conducted in residential areas of Belgrade and over 35 municipalities in Serbia. The main objective of the paper is to present practical solutions in the evaluation of broadband measurement uncertainty for the in-situ RF radiation levels. [Projekat Ministarstva nauke Republike Srbije, br. III43009

SOR/72-43 Radiation Emitting Devices Regulations

International Nuclear Information System (INIS)

1972-01-01

These Regulations of 10 February 1972, supplemented by SOR/77-895, lay down the classes of radiation emitting devices for the purposes of the Radiation Emitting Devices Act. They lay down their standards of design and construction and warning sign specifications and provide for the procedure to be followed by inspectors of such devices. The devices include inter alia extra-oral dental x-ray equipment, baggage inspection x-ray devices, laser scanners, television receivers. (NEA)

Radiation-emitting Electronic Product Codes

Data.gov (United States)

U.S. Department of Health & Human Services — This database contains product names and associated information developed by the Center for all products, both medical and non-medical, which emit radiation. It...

Public Exposure from Indoor Radiofrequency Radiation in the City of Hebron, West Bank-Palestine.

Science.gov (United States)

Lahham, Adnan; Sharabati, Afefeh; ALMasri, Hussien

2015-08-01

This work presents the results of measured indoor exposure levels to radiofrequency (RF) radiation emitting sources in one of the major cities in the West Bank-the city of Hebron. Investigated RF emitters include FM, TV broadcasting stations, mobile telephony base stations, cordless phones [Digital Enhanced Cordless Telecommunications (DECT)], and wireless local area networks (WLAN). Measurements of power density were conducted in 343 locations representing different site categories in the city. The maximum total power density found at any location was about 2.3 × 10 W m with a corresponding exposure quotient of about 0.01. This value is well below unity, indicating compliance with the guidelines of the International Commission on Non-ionizing Radiation Protection (ICNIRP). The average total exposure from all RF sources was 0.08 × 10 W m. The relative contributions from different sources to the total exposure in terms of exposure quotient were evaluated and found to be 46% from FM radio, 26% from GSM900, 15% from DECT phones, 9% from WLAN, 3% from unknown sources, and 1% from TV broadcasting. RF sources located outdoors contribute about 73% to the population exposure indoors.

Measuring Radiofrequency and Microwave Radiation from Varying Signal Strengths

Science.gov (United States)

Davis, Bette; Gaul, W. C.

2007-01-01

This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance.

Radiofrequency electromagnetic radiation exposure inside the metro tube infrastructure in Warszawa.

Science.gov (United States)

Gryz, Krzysztof; Karpowicz, Jolanta

2015-09-01

Antennas from various wireless communications systems [e.g. mobile phones base transceiver stations (BTS) and handsets used by passengers, public Internet access, staff radiophone transmitters used between engine-drivers and traffic operators] emitting radiofrequency electromagnetic radiation (RF-EMR) are used inside underground metro public transportation. Frequency-selective exposimetric investigations of RF-EMR exposure inside the metro infrastructure in Warsaw (inside metro cars passing between stations and on platforms) were performed. The statistical parameters of exposure to the E-field were analyzed for each frequency range and for a total value (representing the wide-band result of measurements of complex exposure). The recorded exposimetric profiles showed the dominant RF-EMR sources: handsets and BTS of mobile communication systems (GSM 900 and UMTS 2100) and local wireless Internet access (WiFi 2G). Investigations showed that the GSM 900 system is the dominant source of exposure - BTS (incessantly active) on platforms, and handsets - used by passengers present nearby during the tube drive. The recorded E-field varies between sources (for BTS were: medians - 0.22 V/m and 75th percentile - 0.37 V/m; and for handsets: medians - 0.28 V/m and 75th percentile - 0.47 V/m). Maximum levels (peaks) of exposure recorded from mobile handsets exceeded 10 V/m (upper limit of used exposimeters). Broadband measurements of E-field, including the dominant signal emitted by staff radiophones (151 MHz), showed that the level of this exposure of engine-drivers does not exceed 2.5 V/m.

The effects of radiofrequency electromagnetic radiation on sperm function.

Science.gov (United States)

Houston, B J; Nixon, B; King, B V; De Iuliis, G N; Aitken, R J

2016-12-01

Mobile phone usage has become an integral part of our lives. However, the effects of the radiofrequency electromagnetic radiation (RF-EMR) emitted by these devices on biological systems and specifically the reproductive systems are currently under active debate. A fundamental hindrance to the current debate is that there is no clear mechanism of how such non-ionising radiation influences biological systems. Therefore, we explored the documented impacts of RF-EMR on the male reproductive system and considered any common observations that could provide insights on a potential mechanism. Among a total of 27 studies investigating the effects of RF-EMR on the male reproductive system, negative consequences of exposure were reported in 21. Within these 21 studies, 11 of the 15 that investigated sperm motility reported significant declines, 7 of 7 that measured the production of reactive oxygen species (ROS) documented elevated levels and 4 of 5 studies that probed for DNA damage highlighted increased damage due to RF-EMR exposure. Associated with this, RF-EMR treatment reduced the antioxidant levels in 6 of 6 studies that discussed this phenomenon, whereas consequences of RF-EMR were successfully ameliorated with the supplementation of antioxidants in all 3 studies that carried out these experiments. In light of this, we envisage a two-step mechanism whereby RF-EMR is able to induce mitochondrial dysfunction leading to elevated ROS production. A continued focus on research, which aims to shed light on the biological effects of RF-EMR will allow us to test and assess this proposed mechanism in a variety of cell types. © 2016 Society for Reproduction and Fertility.

Tunable radiation emitting semiconductor device

NARCIS (Netherlands)

2009-01-01

A tunable radiation emitting semiconductor device includes at least one elongated structure at least partially fabricated from one or more semiconductor materials exhibiting a bandgap characteristic including one or more energy transitions whose energies correspond to photon energies of light

Radiofrequency radiation injures trees around mobile phone base stations.

Science.gov (United States)

Waldmann-Selsam, Cornelia; Balmori-de la Puente, Alfonso; Breunig, Helmut; Balmori, Alfonso

2016-12-01

In the last two decades, the deployment of phone masts around the world has taken place and, for many years, there has been a discussion in the scientific community about the possible environmental impact from mobile phone base stations. Trees have several advantages over animals as experimental subjects and the aim of this study was to verify whether there is a connection between unusual (generally unilateral) tree damage and radiofrequency exposure. To achieve this, a detailed long-term (2006-2015) field monitoring study was performed in the cities of Bamberg and Hallstadt (Germany). During monitoring, observations and photographic recordings of unusual or unexplainable tree damage were taken, alongside the measurement of electromagnetic radiation. In 2015 measurements of RF-EMF (Radiofrequency Electromagnetic Fields) were carried out. A polygon spanning both cities was chosen as the study site, where 144 measurements of the radiofrequency of electromagnetic fields were taken at a height of 1.5m in streets and parks at different locations. By interpolation of the 144 measurement points, we were able to compile an electromagnetic map of the power flux density in Bamberg and Hallstadt. We selected 60 damaged trees, in addition to 30 randomly selected trees and 30 trees in low radiation areas (n=120) in this polygon. The measurements of all trees revealed significant differences between the damaged side facing a phone mast and the opposite side, as well as differences between the exposed side of damaged trees and all other groups of trees in both sides. Thus, we found that side differences in measured values of power flux density corresponded to side differences in damage. The 30 selected trees in low radiation areas (no visual contact to any phone mast and power flux density under 50μW/m 2 ) showed no damage. Statistical analysis demonstrated that electromagnetic radiation from mobile phone masts is harmful for trees. These results are consistent with the fact

Radiofrequency (RF) radiation measurement for diathermy machine

International Nuclear Information System (INIS)

Rozaimah Abdul Rahim; Roha Tukimin; Mohd Amirul Nizam; Ahmad Fadzli; Mohd Azizi

2010-01-01

Full-text: Diathermy machine is one of medical device that use widely in hospital and clinic. During the diathermy treatment, high radiofrequency (RF) currents (shortwave and microwave) are used to heat deep muscular tissues through electromagnetic energy to body tissues. The heat increases blood flow, relieve pain and speeding up recovery. The stray RF radiation from the machine can exposes to unintended tissue of the patient, to the operator (physical therapist) and also can cause electromagnetic interference (EMI) effect to medical devices around the machine. The main objective of this study is to establish a database of the RF radiation exposure levels experienced by the operator and patient during the treatments. RF radiation (electric and magnetic field) produced by the diathermy machines were measured using special RF survey meters. The finding of this study confirms that radiation levels on the surface and near the applicator of the diathermy machine much more elevated due to the much closer distance to the source and they exceeding the occupational and general public exposure limit. The results also shows the field strengths drop very significantly when the distance of measurement increase. (author)

Review: Weak radiofrequency radiation exposure from mobile phone radiation on plants.

Science.gov (United States)

Halgamuge, Malka N

2017-01-01

The aim of this article was to explore the hypothesis that non-thermal, weak, radiofrequency electromagnetic fields (RF-EMF) have an effect on living plants. In this study, we performed an analysis of the data extracted from the 45 peer-reviewed scientific publications (1996-2016) describing 169 experimental observations to detect the physiological and morphological changes in plants due to the non-thermal RF-EMF effects from mobile phone radiation. Twenty-nine different species of plants were considered in this work. Our analysis demonstrates that the data from a substantial amount of the studies on RF-EMFs from mobile phones show physiological and/or morphological effects (89.9%, p radiofrequency radiation influence on plants. Hence, this study provides new evidence supporting our hypothesis. Nonetheless, this endorses the need for more experiments to observe the effects of RF-EMFs, especially for the longer exposure durations, using the whole organisms. The above observation agrees with our earlier study, in that it supported that it is not a well-grounded method to characterize biological effects without considering the exposure duration. Nevertheless, none of these findings can be directly associated with human; however, on the other hand, this cannot be excluded, as it can impact the human welfare and health, either directly or indirectly, due to their complexity and varied effects (calcium metabolism, stress proteins, etc.). This study should be useful as a reference for researchers conducting epidemiological studies and the long-term experiments, using whole organisms, to observe the effects of RF-EMFs.

Radiation Emitting Product Corrective Actions and Recalls

Data.gov (United States)

U.S. Department of Health & Human Services — This database provides descriptions of radiation-emitting products that have been recalled under an approved corrective action plan to remove defective and...

Occupational exposure of NRM spectrometrists to static and radiofrequency fields

International Nuclear Information System (INIS)

Berlana, Tania; Ubeda, Alejandro

2017-01-01

Occupational exposure to static and radiofrequency fields emitted by nuclear magnetic resonance spectrometers was assessed through systematic field metering during operation of 19 devices in nine research centers. Whereas no measurable levels of radiofrequency radiation were registered outside the spectrometers, significant exposure to static field was detected, with maximum values recorded at the user s hand (B = 683.00 mT) and head thorax (B = 135.70 mT) during spectrometer manipulation. All values were well below the exposure limits set by the European standard for workers protection against the effects of acute field exposure only. As for potential effects of chronic exposure, waiting for more complete knowledge, adoption of technical and operational strategies for exposure minimizing is advisable. In this respect, the data revealed that compared with standard magnetic shielding, ultra-shield technology allows a 20-65-fold reduction of the field strength received by the operator. (authors)

Radiofrequency radiation leakage from microwave ovens

International Nuclear Information System (INIS)

Lahham, A.; Sharabati, A.

2013-01-01

This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm -1 with an average value equalling 3.64 μW cm -2 . Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm -2 . The highest radiation leakage from any tested oven was ∼16.4 μW cm -2 , and found in two cases only. In no case did the leakage exceed the limit of 1 μWcm -1 recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age. (authors)

Increased Microleakage of Amalgam Restorations after Exposure to 2.4 Ghz Radiofrequency Electromagnetic Fields from Common Wi-Fi Routers

Directory of Open Access Journals (Sweden)

Mortazavi SMJ

2017-09-01

Full Text Available Statement of Problem: Previous studies have shown that exposure of dental amalgam fillings to MRI and mobile phones can increase microleakage of amalgam restorations. Objectives: The aim of this study was to evaluate the effects of exposure to radiofrequency radiation emitted from indoor Wi-Fi access devices on microleakage of amalgam restorations. Materials and Methods: Standard class V cavities were prepared on the buccal surfaces of 69 extracted human premolar teeth. The samples were divided into two exposure groups and one non-exposed control group of 23 teeth each. The specimens in the experimental groups were exposed to a radiofrequency (RF radiation emitted from a commercial 2.4 GHz Wi Fi router. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. Teeth samples in the first exposure group (group A were exposed to RF for 3 days while the second exposure group (group B was exposed for 6 days. Then the teeth were sectioned and scored for microleakage under a stereomicroscope. Results: The score of microleakage was significantly higher in the exposure group A compared to that of the control group. However, the score of microleakage was not significantly different between the exposure group B and control group. Furthermore, the scores of microleakage was signifi-cantly higher in the exposure group A than that of the exposure group B. Conclusions: Exposure of patients with amalgam restorations to radiofre-quency waves emitted from commercial Wi-Fi routers can lead to in-creased microleakage of amalgam restorations.

Radiofrequency radiation exposure from RF-generating plant

International Nuclear Information System (INIS)

Wright, J.M.; Bell, K.M.

2000-01-01

As part of an intervention to assist industry improve the control of risks associated with the use of RF-generating plant, exposure to radiofrequency radiation (RFR) was assessed in 30 workplaces. Information about the workplace, work practices and knowledge about RFR and its control was also collected. The study found that: 1. For 72% of operators and 35% of bystanders, the spatially averaged exposure exceeded the exposure limits. These figures approximately halved when the duty cycle was applied; 2. Assessment of RFR levels was not common; 3. Task rotation was used to limit exposure of operators; 4. Access was not controlled to areas where RFR sources were used; 5. There was lack of knowledge about RF shielding practices in industry; 6. Nearly 50% of workplaces did not maintain the plant regularly; and 7. There had been no health surveillance on any plant operators in any of the workplaces in the study. Copyright (2000) Australasian Radiation Protection Society Inc

Bill C-5, an act to amend the radiation emitting devices act

International Nuclear Information System (INIS)

1984-01-01

This Act, entitled Bill C-5, allows for a series of amendments to the Radiation Emitting Devices Act. The amendments relate to regulations concerned with the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of radiation emitting devices

Risk assessment and management of radiofrequency radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Dabala, Dana [Railways Medical Clinic Cluj-Napoca, Occupational Medicine Department, 16-20 Bilascu Gheorghe St., 400015 Cluj-Napoca (Romania); Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath St., 400293 Cluj-Napoca (Romania)

2013-11-13

Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management.

Risk assessment and management of radiofrequency radiation exposure

International Nuclear Information System (INIS)

Dabala, Dana; Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia

2013-01-01

Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management

ECG changes in factory workers exposed to 27.2  MHz radiofrequency radiation.

Science.gov (United States)

Chen, Qingsong; Xu, Guoyong; Lang, Li; Yang, Aichu; Li, Shilin; Yang, Liwen; Li, Chaolin; Huang, Hanlin; Li, Tao

2013-05-01

To research the effect of 27.2 MHz radiofrequency radiation on electrocardiograms (ECG), 225 female workers operating radiofrequency machines at a shoe factory were chosen as the exposure group and 100 female workers without exposure from the same factory were selected as the control group. The 6 min electric field strength that the female workers were exposed to was 64.0 ± 25.2 V/m (mean ± SD), which exceeded 61 V/m, the International Commission on Non-Ionizing Radiation Protection reference root mean square levels for occupational exposure. A statistical difference was observed between the exposed group and the control group in terms of the rate of sinus bradycardia (χ(2)  = 11.48, P = 0.003). When several known risk factors for cardiovascular disease were considered, including smoking, age, alcohol ingestion habit, and so on, the exposure duration was not an effective factor for ECG changes, sinus arrhythmia, or sinus bradycardia according to α = 0.05, while P = 0.052 for sinus arrhythmia was very close to 0.05. We did not find any statistical difference in heart rate, duration of the QRS wave (ventricular depolarization), or corrected QT intervals (between the start of the Q wave and end of the T wave) between the exposed and control groups. Occupational exposure to radiofrequency radiation was not found to be a cause of ECG changes after consideration of the confounding factors. Copyright © 2012 Wiley Periodicals, Inc.

Non-Linear Adaptive Phenomena Which Decrease The Risk of Infection After Pre-Exposure to Radiofrequency Radiation

OpenAIRE

Mortazavi, S.M.J.; Motamedifar, M.; Namdari, G.; Taheri, M.; Mortazavi, A.R.; Shokrpour, N.

2013-01-01

Substantial evidence indicates that adaptive response induced by low doses of ionizing radiation can result in resistance to the damage caused by a subsequently high-dose radiation or cause cross-resistance to other non-radiation stressors. Adaptive response contradicts the linear-non-threshold (LNT) dose-response model for ionizing radiation. We have previously reported that exposure of laboratory animals to radiofrequency radiation can induce a survival adaptive response. Furthermore, we ha...

Measurement and analysis of radiofrequency radiations from some mobile phone base stations in Ghana

International Nuclear Information System (INIS)

Amoako, J. K.; Fletcher, J. J.; Darko, E. O.

2009-01-01

A survey of the radiofrequency electromagnetic radiation at public access points in the vicinity of 50 cellular phone base stations has been carried out. The primary objective was to measure and analyse the electromagnetic field strength levels emitted by antennae installed and operated by the Ghana Telecommunications Company. On all the sites measurements were made using a hand-held spectrum analyser to determine the electric field level with the 900 and 1800 MHz frequency bands. The results indicated that power densities at public access points varied from as low as 0.01 μW m -2 to as high as 10 μW m -2 for the frequency of 900 MHz. At a transmission frequency of 1800 MHz, the variation of power densities is from 0.01 to 100 μW m -2 . The results were found to be in compliant with the International Commission on Non-ionizing Radiological Protection guidance level but were 20 times higher than the results generally obtained for such a practice elsewhere. There is therefore a need to re-assess the situation to ensure reduction in the present level as an increase in mobile phone usage is envisaged within the next few years. (authors)

Measurement and analysis of radiofrequency radiations from some mobile phone base stations in Ghana.

Science.gov (United States)

Amoako, J K; Fletcher, J J; Darko, E O

2009-08-01

A survey of the radiofrequency electromagnetic radiation at public access points in the vicinity of 50 cellular phone base stations has been carried out. The primary objective was to measure and analyse the electromagnetic field strength levels emitted by antennae installed and operated by the Ghana Telecommunications Company. On all the sites measurements were made using a hand-held spectrum analyser to determine the electric field level with the 900 and 1800 MHz frequency bands. The results indicated that power densities at public access points varied from as low as 0.01 microW m(-2) to as high as 10 microW m(-2) for the frequency of 900 MHz. At a transmission frequency of 1800 MHz, the variation of power densities is from 0.01 to 100 microW m(-2). The results were found to be in compliant with the International Commission on Non-ionizing Radiological Protection guidance level but were 20 times higher than the results generally obtained for such a practice elsewhere. There is therefore a need to re-assess the situation to ensure reduction in the present level as an increase in mobile phone usage is envisaged within the next few years.

Effects of radiofrequency radiation emitted by cellular telephones on the cognitive functions of humans.

Science.gov (United States)

Eliyahu, Ilan; Luria, Roy; Hareuveny, Ronen; Margaliot, Menachem; Meiran, Nachshon; Shani, Gad

2006-02-01

The present study examined the effects of exposure to Electromagnetic Radiation emitted by a standard GSM phone at 890 MHz on human cognitive functions. This study attempted to establish a connection between the exposure of a specific area of the brain and the cognitive functions associated with that area. A total of 36 healthy right-handed male subjects performed four distinct cognitive tasks: spatial item recognition, verbal item recognition, and two spatial compatibility tasks. Tasks were chosen according to the brain side they are assumed to activate. All subjects performed the tasks under three exposure conditions: right side, left side, and sham exposure. The phones were controlled by a base station simulator and operated at their full power. We have recorded the reaction times (RTs) and accuracy of the responses. The experiments consisted of two sections, of 1 h each, with a 5 min break in between. The tasks and the exposure regimes were counterbalanced. The results indicated that the exposure of the left side of the brain slows down the left-hand response time, in the second-later-part of the experiment. This effect was apparent in three of the four tasks, and was highly significant in only one of the tests. The exposure intensity and its duration exceeded the common exposure of cellular phone users.

World Health Organization, radiofrequency radiation and health - a hard nut to crack (Review)

OpenAIRE

Hardell, Lennart

2017-01-01

In May 2011 the International Agency for Research on Cancer (IARC) evaluated cancer risks from radiofrequency (RF) radiation. Human epidemiological studies gave evidence of increased risk for glioma and acoustic neuroma. RF radiation was classified as Group 2B, a possible human carcinogen. Further epidemiological, animal and mechanistic studies have strengthened the association. In spite of this, in most countries little or nothing has been done to reduce exposure and educate people on health...

Radiofrequency Electromagnetic Radiation and Memory Performance: Sources of Uncertainty in Epidemiological Cohort Studies.

Science.gov (United States)

Brzozek, Christopher; Benke, Kurt K; Zeleke, Berihun M; Abramson, Michael J; Benke, Geza

2018-03-26

Uncertainty in experimental studies of exposure to radiation from mobile phones has in the past only been framed within the context of statistical variability. It is now becoming more apparent to researchers that epistemic or reducible uncertainties can also affect the total error in results. These uncertainties are derived from a wide range of sources including human error, such as data transcription, model structure, measurement and linguistic errors in communication. The issue of epistemic uncertainty is reviewed and interpreted in the context of the MoRPhEUS, ExPOSURE and HERMES cohort studies which investigate the effect of radiofrequency electromagnetic radiation from mobile phones on memory performance. Research into this field has found inconsistent results due to limitations from a range of epistemic sources. Potential analytic approaches are suggested based on quantification of epistemic error using Monte Carlo simulation. It is recommended that future studies investigating the relationship between radiofrequency electromagnetic radiation and memory performance pay more attention to treatment of epistemic uncertainties as well as further research into improving exposure assessment. Use of directed acyclic graphs is also encouraged to display the assumed covariate relationship.

Radiofrequency Electromagnetic Radiation and Memory Performance: Sources of Uncertainty in Epidemiological Cohort Studies

Directory of Open Access Journals (Sweden)

Christopher Brzozek

2018-03-01

Full Text Available Uncertainty in experimental studies of exposure to radiation from mobile phones has in the past only been framed within the context of statistical variability. It is now becoming more apparent to researchers that epistemic or reducible uncertainties can also affect the total error in results. These uncertainties are derived from a wide range of sources including human error, such as data transcription, model structure, measurement and linguistic errors in communication. The issue of epistemic uncertainty is reviewed and interpreted in the context of the MoRPhEUS, ExPOSURE and HERMES cohort studies which investigate the effect of radiofrequency electromagnetic radiation from mobile phones on memory performance. Research into this field has found inconsistent results due to limitations from a range of epistemic sources. Potential analytic approaches are suggested based on quantification of epistemic error using Monte Carlo simulation. It is recommended that future studies investigating the relationship between radiofrequency electromagnetic radiation and memory performance pay more attention to treatment of epistemic uncertainties as well as further research into improving exposure assessment. Use of directed acyclic graphs is also encouraged to display the assumed covariate relationship.

Survey of radiofrequency radiation levels around GSM base stations and evaluation of measurement uncertainty

Directory of Open Access Journals (Sweden)

Vulević Branislav D.

2011-01-01

Full Text Available This paper is a summary of broadband measurement values of radiofrequency radiation around GSM base stations in the vicinity of residential areas in Belgrade and 12 other cities in Serbia. It will be useful for determining non-ionizing radiation exposure levels of the general public in the future. The purpose of this paper is also an appropriate representation of basic information on the evaluation of measurement uncertainty.

Exposure to radiofrequency radiation from diathermy units in medicine

International Nuclear Information System (INIS)

Hrnjak, M.; Zivkovic, D.; Milicevic, L.

1998-01-01

Intensities of microwave (MW) and radio wave (short wave) radiation to whom personnel occupied in use of radiofrequency (RF) diathermy in physical therapy could be exposed were measured in two hospitals, in two therapy wards. The Narda Microwave Corp. (USA) Broadband Radiation Meter - Model 8616, with appropriate probes, was used for measurements. The measurements were performed around the 3 types of diathermy units in various ways of application. Results of the measurements showed that the intensities of short waves radiation around the applicators, cables and units (at the distance of 30 cm) ranged from 187 mW/cm sup 2 , and on the majority of measuring points were considerably over the upper exposure limit of 1,22 mW/cm sup 2 (according to JUS N.NO.205:1190 limits of exposure to RF fields). Intensities of microwave radiation in the vicinity of units and patient range from <0,002 to 1,45 mW/cm sup 2. The intensities of MW radiation are over the exposure limit of 1 mW/cm sup 2 in two measuring points. Results of measurements show that personnel occupied in use of microwave and short wave diathermy in medicine could be regularly exposed to radiation, and that this radiation has considerably high intensity in the vicinity of the therapy unit and patient (author)

Effect of Mobile Phone Radiofrequency Electromagnetic Fields on ...

African Journals Online (AJOL)

olayemitoyin

Summary: Since cell phones emit radiofrequency electromagnetic fields (EMFs), this study tested the hypothesis that cell phones placed ... mobile phones on autonomic modulation of the heart. ..... Electrocardiogram and Its Technology. J. Am.

Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood-brain barrier in male & female rats.

Science.gov (United States)

Sırav, Bahriye; Seyhan, Nesrin

2016-09-01

With the increased use of mobile phones, their biological and health effects have become more important. Usage of mobile phones near the head increases the possibility of effects on brain tissue. This study was designed to investigate the possible effects of pulse modulated 900MHz and 1800MHz radio-frequency radiation on the permeability of blood-brain barrier of rats. Study was performed with 6 groups of young adult male and female wistar albino rats. The permeability of blood-brain barrier to intravenously injected evans blue dye was quantitatively examined for both control and radio-frequency radiarion exposed groups. For male groups; Evans blue content in the whole brain was found to be 0.08±0.01mg% in the control, 0.13±0.03mg% in 900MHz exposed and 0.26±0.05mg% in 1800MHz exposed animals. In both male radio-frequency radiation exposed groups, the permeability of blood-brain barrier found to be increased with respect to the controls (pradiation exposure was found more effective on the male animals (p0.01). However 900MHz pulse modulated radio-frequency exposure was found effective on the permeability of blood-brain barrier of female animals. Results have shown that 20min pulse modulated radio-frequency radiation exposure of 900MHz and 1800MHz induces an effect and increases the permeability of blood-brain barrier of male rats. For females, 900MHz was found effective and it could be concluded that this result may due to the physiological differences between female and male animals. The results of this study suggest that mobile phone radation could lead to increase the permeability of blood-brain barrier under non-thermal exposure levels. More studies are needed to demonstrate the mechanisms of that breakdown. Copyright © 2015 Elsevier B.V. All rights reserved.

An assessment of ultraviolet radiation components of light emitted ...

African Journals Online (AJOL)

An assessment of ultraviolet radiation components of light emitted from electric arc and their possible exposure risks. ... The study of Ultraviolet Radiation has of recent become interesting because of the health hazards it poses to human. Apart from its intensity reaching the earth from the sun, other man-made sources have ...

Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development

Science.gov (United States)

Sage, Cindy; Burgio, Ernesto

2018-01-01

Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes…

Industrial assessment of radiofrequency and microwave radiations: case study at electronic manufacturing industries in Penang

International Nuclear Information System (INIS)

Mohd Zaid Abdullah

1996-01-01

In electronic manufacturing industry, the applications of an equipment emitting radiofrequency radiation (RFR) are numerous and Increasing. It is known that exposure to RFR at sufficiently high intensity and duration can produce a variety of adverse health effects. This paper presents some results from an extensive studies in the RFR field measurements at frequency range from 100 MHz to 1 GHz. All measurements were performed inside factories located at the Penang Free Trade Zone. In this case, the factories chosen are those that manufacture the electronic components whereby the applications of RFR equipment are likely to be intensive compared to other type of industries. The measurement system used in this study are the portable spectrum-analyzer, the passive log-periodic antenna and a desktop computer for data analysis. Results from this study have indicated that the RFR exposure levels in most factories are in the range of 7.7 x 10 sup -4 - 4.31 x 10 sup -3 Wm sup -2 and 0.01 - 0. 741 Vm sup -1 for power density and electric strength measurement respectively. These ranges are at least 100 times lower compared to the RFR protection guidelines proposed by the American National Standard Institute (ANSI). However, the exposure levels inside the factory are consistently 10 sup -3 - 10 sup -4 higher than the levels caused by natural sources and is about 10 sup 2 - 10 sup 6 higher than the levels measured at a distance of 30 m from a low-power output mobile phone transmitter. In the case of the health effect assessment, no sufficient evidence has been found to indicate the potential consequences resulting from excessive RFR exposure. Nonetheless, many factories surveyed are unaware of the existence of the international guidelines and codes on the safe use of radiofrequency energy even though, some measures are being taken to protect their employees against RFR

Radiation exposure to patients and operator during radiofrequency ablation for supraventricular tachycardia

International Nuclear Information System (INIS)

Kovoor, P.; Ricciardello, M.; Collins, L.; Uther, J.B.; Ross, D.L.

1995-01-01

Radiofrequency (RF) ablation has become the primary method of treatment for supraventricular tachycardia and often requires prolonged fluoroscopy times. The aim of this study was to quantitate radiation exposure to patient and operator during RF ablation for supra- ventricular tachycardia. Thermoluminescent dosemeters were used to monitor radiation at seven sites. Positions were: patient's thyroid, left scapula, T9 vertebra, right scapula and L4-L5 vertebra and the operator's thyroid and left hand. Monitoring was performed during 22 procedures. Of the patients studied 10 (45%) had atrioventricular junctional re-entry tachycardia (AVJRT) and 12 (55%) had accessory pathway tachycardia. The median fluoroscopy times (minutes) and inter-quartile ranges were 46 (39-65) for AVJRT, 55 (52-60) for left free wall accessory pathway (LFW), 107 (89-140) for septal and 166 (128-176) for RFW pathways. The mean radiation doses (mGy) to the chest wall were 50 for AVJRT, 47 for LFW, 87 for septal and 151 for RFW pathways. The mean radiation to the chest wall of the patient per case was found to be 3.9 times that reported for diagnostic cardiac catheterisation and 1.5 times that reported for angioplasty. It is concluded that radiofrequency ablation is associated with significant irradiation of the patient and operator. All precautions should be taken to decrease this exposure. If eye irradiation is assumed to be equal to that to the thyroid, more than 45 procedures per month by a single operator (using ceiling-suspended lead glass shielding) may result in exceeding the recommended dose limit to the eye. 32 refs., 3 tabs

Transmission of Mössbauer rays through ferromagnets in radio-frequency magnetic field

International Nuclear Information System (INIS)

Dzyublik, A. Ya.; Sadykov, E. K.; Petrov, G. I.; Arinin, V. V.; Vagizov, F. G.; Spivak, V. Yu.

2013-01-01

The transmission of Mössbauer radiation through a thick ferromagnetic crystal, exposed to a radio-frequency (rf) magnetic field, is studied. The quantum-mechanical dynamical scattering theory is developed, taking into account the periodical reversals of the magnetic field at the nuclei. The Mössbauer forward scattering (FS) spectra of the weak ferromagnet FeBO 3 placed into rf field are measured. It is found that the coherent gamma wave in the crystal absorbs or emits only couples of the rf photons. As a result, the FS spectra consist of equidistant lines spaced by twice the frequency of the rf field in contrast to the absorption spectra

Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L

Energy Technology Data Exchange (ETDEWEB)

Tkalec, Mirta [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)], E-mail: mtkalec@zg.biol.pmf.hr; Malaric, Kresimir [Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000 Zagreb (Croatia); Pevalek-Kozlina, Branka [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)

2007-12-15

Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological responses of the plant Lemna minor after exposure to radiofrequency EMFs, and in particular, to clarify the possible role of oxidative stress in the observed effects. Duckweed was exposed for 2 h to EMFs of 400 and 900 MHz at field strengths of 10, 23, 41 and 120 V m{sup -1}. The effect of a longer exposure time (4 h) and modulation was also investigated. After exposure, parameters of oxidative stress, such as lipid peroxidation, H{sub 2}O{sub 2} content, activities and isoenzyme pattern of antioxidative enzymes as well as HSP70 expression were evaluated. At 400 MHz, lipid peroxidation and H{sub 2}O{sub 2} content were significantly enhanced in duckweed exposed to EMFs of 23 and 120 V m{sup -1} while other exposure treatments did not have an effect. Compared to the controls, the activities of antioxidative enzymes showed different behaviour: catalase (CAT) activity increased after most exposure treatments while pyrogallol (PPX) and ascorbate peroxidase (APX) activities were not changed. Exceptions were reduced PPX and APX activity after longer exposure at 23 V m{sup -1} and increased PPX activity after exposures at 10 and 120 V m{sup -1}. By contrast, at 900 MHz almost all exposure treatments significantly increased level of lipid peroxidation and H{sub 2}O{sub 2} content but mostly decreased PPX activity and did not affect CAT activity. Exceptions were exposures to a modulated field and to the field of 120 V m{sup -1} which increased PPX and CAT activity. At this frequency APX activity was significantly decreased after exposure at 10 V m{sup -1} and longer exposure at 23 V m{sup -1} but it increased after a shorter exposure at

Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L

International Nuclear Information System (INIS)

Tkalec, Mirta; Malaric, Kresimir; Pevalek-Kozlina, Branka

2007-01-01

Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological responses of the plant Lemna minor after exposure to radiofrequency EMFs, and in particular, to clarify the possible role of oxidative stress in the observed effects. Duckweed was exposed for 2 h to EMFs of 400 and 900 MHz at field strengths of 10, 23, 41 and 120 V m -1 . The effect of a longer exposure time (4 h) and modulation was also investigated. After exposure, parameters of oxidative stress, such as lipid peroxidation, H 2 O 2 content, activities and isoenzyme pattern of antioxidative enzymes as well as HSP70 expression were evaluated. At 400 MHz, lipid peroxidation and H 2 O 2 content were significantly enhanced in duckweed exposed to EMFs of 23 and 120 V m -1 while other exposure treatments did not have an effect. Compared to the controls, the activities of antioxidative enzymes showed different behaviour: catalase (CAT) activity increased after most exposure treatments while pyrogallol (PPX) and ascorbate peroxidase (APX) activities were not changed. Exceptions were reduced PPX and APX activity after longer exposure at 23 V m -1 and increased PPX activity after exposures at 10 and 120 V m -1 . By contrast, at 900 MHz almost all exposure treatments significantly increased level of lipid peroxidation and H 2 O 2 content but mostly decreased PPX activity and did not affect CAT activity. Exceptions were exposures to a modulated field and to the field of 120 V m -1 which increased PPX and CAT activity. At this frequency APX activity was significantly decreased after exposure at 10 V m -1 and longer exposure at 23 V m -1 but it increased after a shorter exposure at 23 V m -1 . At both frequencies no differences in isoenzyme

Acute effects of radiofrequency electromagnetic field emitted by mobile phone on brain function.

Science.gov (United States)

Zhang, Jun; Sumich, Alexander; Wang, Grace Y

2017-07-01

Due to its attributes, characteristics, and technological resources, the mobile phone (MP) has become one of the most commonly used communication devices. Historically, ample evidence has ruled out the substantial short-term impact of radiofrequency electromagnetic field (RF-EMF) emitted by MP on human cognitive performance. However, more recent evidence suggests potential harmful effects associated with MP EMF exposure. The aim of this review is to readdress the question of whether the effect of MP EMF exposure on brain function should be reopened. We strengthen our argument focusing on recent neuroimaging and electroencephalography studies, in order to present a more specific analysis of effects of MP EMF exposure on neurocognitive function. Several studies indicate an increase in cortical excitability and/or efficiency with EMF exposure, which appears to be more prominent in fronto-temporal regions and has been associated with faster reaction time. Cortical excitability might also underpin disruption to sleep. However, several inconsistent findings exist, and conclusions regarding adverse effects of EMF exposure are currently limited. It also should be noted that the crucial scientific question of the effect of longer-term MP EMF exposure on brain function remains unanswered and essentially unaddressed. Bioelectromagnetics. 38:329-338, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

A Technical Approach to the Evaluation of Radiofrequency Radiation Emissions from Mobile Telephony Base Stations

Directory of Open Access Journals (Sweden)

Raimondas Buckus

2017-03-01

Full Text Available During the last two decades, the number of macrocell mobile telephony base station antennas emitting radiofrequency (RF electromagnetic radiation (EMR in residential areas has increased significantly, and therefore much more attention is being paid to RF EMR and its effects on human health. Scientific field measurements of public exposure to RF EMR (specifically to radio frequency radiation from macrocell mobile telephony base station antennas and RF electromagnetic field (EMF intensity parameters in the environment are discussed in this article. The research methodology is applied according to the requirements of safety norms and Lithuanian Standards in English (LST EN. The article presents and analyses RF EMFs generated by mobile telephony base station antennas in areas accessible to the general public. Measurements of the RF electric field strength and RF EMF power density were conducted in the near- and far-fields of the mobile telephony base station antenna. Broadband and frequency-selective measurements were performed outside (on the roof and on the ground and in a residential area. The tests performed on the roof in front of the mobile telephony base station antennas in the near-field revealed the presence of a dynamic energy interaction within the antenna electric field, which changes rapidly with distance. The RF EMF power density values on the ground at distances of 50, 100, 200, 300, 400, and 500 m from the base station are very low and are scattered within intervals of 0.002 to 0.05 μW/cm2. The results were compared with international exposure guidelines (ICNIRP.

A Technical Approach to the Evaluation of Radiofrequency Radiation Emissions from Mobile Telephony Base Stations.

Science.gov (United States)

Buckus, Raimondas; Strukčinskienė, Birute; Raistenskis, Juozas; Stukas, Rimantas; Šidlauskienė, Aurelija; Čerkauskienė, Rimantė; Isopescu, Dorina Nicolina; Stabryla, Jan; Cretescu, Igor

2017-03-01

During the last two decades, the number of macrocell mobile telephony base station antennas emitting radiofrequency (RF) electromagnetic radiation (EMR) in residential areas has increased significantly, and therefore much more attention is being paid to RF EMR and its effects on human health. Scientific field measurements of public exposure to RF EMR (specifically to radio frequency radiation) from macrocell mobile telephony base station antennas and RF electromagnetic field (EMF) intensity parameters in the environment are discussed in this article. The research methodology is applied according to the requirements of safety norms and Lithuanian Standards in English (LST EN). The article presents and analyses RF EMFs generated by mobile telephony base station antennas in areas accessible to the general public. Measurements of the RF electric field strength and RF EMF power density were conducted in the near- and far-fields of the mobile telephony base station antenna. Broadband and frequency-selective measurements were performed outside (on the roof and on the ground) and in a residential area. The tests performed on the roof in front of the mobile telephony base station antennas in the near-field revealed the presence of a dynamic energy interaction within the antenna electric field, which changes rapidly with distance. The RF EMF power density values on the ground at distances of 50, 100, 200, 300, 400, and 500 m from the base station are very low and are scattered within intervals of 0.002 to 0.05 μW/cm². The results were compared with international exposure guidelines (ICNIRP).

Radiofrequency elektromagnetic radiation dynamics in vilnius city

OpenAIRE

Staniulytė, Justė

2017-01-01

Aim of the study – evaluate radio frequency electromagnetic radiation energy flux density emitted by Vilnius city base stations in the years 2009 – 2012 and compare results with the Republic of Lithuania hygiene standards HN 80:2011 and HN 80:2015 provisions. Study materials and method. In this paper the UAB (Ltd.)”Akustinių tyrimų centras” prepared measurement protocols of radio engineering objects in Vilnius city were used. Data analysis was performed using the statistical package ”R” 3.4.0...

Can a tachyon emit light radiation in all directions

Energy Technology Data Exchange (ETDEWEB)

Ramanujam, G A [NGM Coll., Tamil Nadu (India). Dept. of Physics

1976-03-01

It is shown here that a critical analysis of the approaches employed by various authors to accommodate tachyons into special relativity leads one to the conclusion that a tachyon can emit light radiation only along its line of motion.

Magnetic resonance in medicine occupational exposure to static magnetic field and radiofrequency radiation

International Nuclear Information System (INIS)

Zivkovic, D.; Hrnjak, M.; Ivanovic, C.

1997-01-01

Medical personnel working with magnetic resonance imaging (MRI) devices could be exposed to static magnetic (M) field, time-varying M fields and radiofrequency (RF) radiation. The aim of work was to investigate the density of magnetic flux of static magnetic field and the power density of RF radiation which appear in the working environment around the 0.5 T MRI unit in one hospital. The density of magnetic flux of static magnetic field was measured with Hall Effect Gauss meter - Magnetech (Great Britain), and the power density of RF radiation was measured with broadband isotropic meter - The Narda Microwave Corp. (USA). The results of measurement show that the density of magnetic flux of static M field on working places are below threshold limit of exposure and the intensities of RF radiation are far below maximum permissible level. (author)

Effect of Mobile Phone Radiofrequency Electromagnetic Fields on ...

African Journals Online (AJOL)

Summary: Since cell phones emit radiofrequency electromagnetic fields (EMFs), this study tested the hypothesis that cell phones placed near the heart may interfere with the electrical rhythm of the heart or affect the blood pressure. Following informed consent, eighteen randomly selected apparently healthy male volunteers ...

Non-radiative recombination losses in polymer light-emitting diodes

NARCIS (Netherlands)

Kuik, M.; Koster, L. J. A.; Dijkstra, A. G.; Wetzelaer, G. A. H.; Blom, P. W. M.

We present a quantitative analysis of the loss of electroluminescence in light-emitting diodes (LEDs) based on poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) due to the combination of non-radiative trap-assisted recombination and exciton quenching at the metallic cathode. It is

Radiofrequency radiation-induced calcium-ion-efflux enhancement from human and other neuroblastoma cells in culture: [Final technical report

International Nuclear Information System (INIS)

Dutta, S.K.; Ghosh, B.; Blackman, C.F.

1988-01-01

In order to test the generality of radiofrequency-radiation-induced change in alternation of 45 Ca/sup 2/plus// efflux from avian and feline brain tissues, human neuroblastoma cells were exposed to electromagnetic radiation at 147 MHz, amplitude modulated (AM) at 16 Hz, at specific absorption rates (SAR) of 0.1, 0.05, 0.01, 0.005, 0.001, and 0.0005 Wkg. Significant 45 Ca/sup 2/plus// efflux was obtained at SAR values of 0.05 and 0.005 Wkg. Enchanced efflux at 0.05 Wkg peaked at the 13-to-16 Hz and at the 57.5-to-60 Hz modulation ranges. A Chinese hamster-mouse hybrid neuroblastoma was also shown to exhibit enchanced radiation-induced 45 Ca/sup 2/plus// efflux at an SAR of 0.05 Wkg, using 147 MHz, AM at 16 hz. These results confirm that amplitude-modulated radiofrequency radiation can induce response in cells of nervous tissue origin from widely different animal species including humans. The results are also consistent with reports of similar findings in avian and feline brain tissue reported by others and indicate the general nature of the phenomenon. 9 refs., 3 tabs

Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling.

Science.gov (United States)

Aerts, Sam; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

2013-10-01

In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information-inside hotspots or in search of them-based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km2. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. Copyright © 2013 Elsevier Inc. All rights

Does Occupational Exposure of Shahid Dastghieb International Airport Workers to Radiofrequency Radiation Affect Their Short Term Memory and Reaction Time?

Directory of Open Access Journals (Sweden)

Jarideh S.

2015-05-01

Full Text Available Background: Airport workers are continuously exposed to different levels of radiofrequency microwave (RF/MW radiation emitted by radar equipments. Radars are extensively used in military and aviation industries. Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and MRI. The main goal of this study was to investigate if occupational exposure of Shahid Dastghieb international airport workers to radiofrequency radiation affects their short term memory and reaction time. Methods: Thirty two airport workers involved in duties at control and approach tower (21 males and 11 females, with the age range of 27-67 years old (mean age of 37.38, participated voluntary in this study. On the other hand, 29 workers (13 males, and 16 females whose offices were in the city with no exposure history to radar systems were also participated in this study as the control group. The employees’ reaction time and short term memory were analyzed using a standard visual reaction time (VRT test software and the modified Wechsler memory scale test, respectively. Results: The mean± SD values for the reaction times of the airport employees (N=32 and the control group (N=29 were 0.45±0.12 sec and 0.46±0.17 sec, respectively. Moreover, in the four subset tests; i.e. paired words, forward digit span, backward digit span and word recognition, the following points were obtained for the airport employees and the control group, respectively: (i pair words test: 28.00±13.13 and 32.07±11.65, (ii forward digit span: 8.38±1.40 and 9.03±1.32, (iii backward digit span: 5.54±1.87 and 6.31±1.46, and (iv word recognition: 5.73±2.36 and 6.50±1.93. These differences were not statistically significant. Conclusion: The occupational exposure of the employees to the RF radiation in Shahid

Automated radiofrequency radiation dosimetry. Final report, Jun 89-Sep 90

Energy Technology Data Exchange (ETDEWEB)

Gandhi, O.P.

1990-12-01

The interaction of radiofrequency (RF) and microwave (MW) electromagnetic radiation with biological tissues is of increasing importance from the standpoint of health and safety. From considerable literature devoted to the study of RF and MW bioeffects based primarily on animal experimentation it has been determined that bioeffects are correlated with mass-normalized rates of RF or MW energy absorption (specific absorption rates or SARs). An emphasis of our project was to improve the efficiency of the SAR algorithms and to extend their use to higher RF and MW frequencies. Another objective was to adapt these algorithms to computing workstations and distributed memory parallel processors that are becoming more affordable and hence readily available to potential users of these codes.

Measurement of Radiofrequency Radiation Exposure in Epidemiological Studies (invited paper)

International Nuclear Information System (INIS)

Swerdlow, A.J.

1999-01-01

The measurement of radiofrequency (RF) exposure is important to the quality of epidemiological studies of the possible association of RF exposure with disease. The extent and type of exposure measurement in past epidemiological studies of RF, and the features of measurement that would be desirable for better studies in the future are summarised. Measurement characteristics that are discussed include quantification of radiation frequency and of intensity and timing of exposures, measurement (or good estimation) of exposures for individuals rather than only for groups, quality of measurement, and measurement of RF exposures experienced outside the study setting. Integration of exposure measurement into the design of epidemiological studies is needed for better assessments of possible RF effects. (author)

Bray–Liebhafsky oscillatory reaction in the radiofrequency electromagnetic field

Energy Technology Data Exchange (ETDEWEB)

Stanisavljev, Dragomir R., E-mail: dragisa@ffh.bg.ac.rs [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, P.O. Box 473, 11001 Belgrade (Serbia); Velikić, Zoran [Institute of Physics, University of Belgrade, Pregrevica 118, Zemun (Serbia); Veselinović, Dragan S.; Jacić, Nevena V.; Milenković, Maja C. [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, P.O. Box 473, 11001 Belgrade (Serbia)

2014-09-30

Highlights: • Oscillatory Bray–Liebhafsky reaction is coupled with the radiofrequency radiation. • The effects of radiofrequency field on oscillatory parameters are investigated. • Radiofrequency power of up to the 0.2 W did not produced observable changes. • The explanation related with dissipative and capacitive effects is given. • Open the possibility of investigations of reactive effects on biological systems. - Abstract: Oscillatory Bray–Liebhafsky (BL) reaction is capacitively coupled with the electromagnetic radiation in the frequency range 60–110 MHz. Because of the specific reaction dynamics characterized by several characteristic parameters (induction period, period between chemical oscillations and their amplitude) it served as a good model system for the investigation of the effects of radiofrequent (RF) radiation. RF power of up to 0.2 W did not produce observable changes of the BL reaction parameters in the limit of the experiment reproductivity. Results indicate that, under the given experimental conditions, both dissipative and reactive properties of the solution are not considerably coupled with the RF electrical field.

Metallic implants and exposure to radiofrequency radiation

International Nuclear Information System (INIS)

Joyner, K.H.; Fleming, A.H.F.; MacFarlane, I.P.; Hocking, B.

1988-01-01

There is increasing use of radiofrequency radiation (RFR) in industry for communications, welding, security, radio, medicine, navigation etc. It has been recognised for some years that RFR may interact with cardiac pacemakers and steps have been taken to prevent this interference. It is less well recognised that other metallic implants may also act as antennas in an RFR field and possibly cause adverse health effects by heating local tissues. There are a large and increasing number of implants having metal components which may be found in RFR workers. These implants include artificial joints, rods and plates used in orthopaedics, rings in heart valves, wires in sutures, bionic ears, subcutaneous infusion systems and (external) transdermal drug delivery patches 1 . The physician concerned with job placement of such persons requires information on the likelihood of an implant interacting with RFR so as to impair health. The following outlines the approach developed in Telecom Australia, beginning with the general principles and then presenting a specific example discussion of a specific example

Potential Hazards of Cellular Phone Radiation: Responses to Fear and Uncertainty

OpenAIRE

Wisz, Jamie T.

2002-01-01

In recent years, the public has become concerned that the electromagnetic radio-frequency radiation (“RF radiationâ€) emitted by cellular telephones may pose serious health risks, including the risk of cancer. There are over 110 million cell phone users in the United States and many of them may not know that cell phones actually send electromagnetic waves into the user’s brain. Depending on how close the cell phone antenna is to oneâ&euro...

Radiofrequency radiation at Stockholm Central Railway Station in Sweden and some medical aspects on public exposure to RF fields

OpenAIRE

Hardell, Lennart; Koppel, Tarmo; Carlberg, Michael; Ahonen, Mikko; Hedendahl, Lena

2016-01-01

The Stockholm Central Railway Station in Sweden was investigated for public radiofrequency (RF) radiation exposure. The exposimeter EME Spy 200 was used to collect the RF exposure data across the railway station. The exposimeter covers 20 different radiofrequency bands from 88 to 5,850 MHz. In total 1,669 data points were recorded. The median value for total exposure was 921 ?W/m2 (or 0.092 ?W/cm2; 1 ?W/m2=0.0001 ?W/cm2) with some outliers over 95,544 ?W/m2 (6 V/m, upper detection limit). The...

Nonionising radiation and risk of human cancer: comparison of ultraviolet and radiofrequency radiation

International Nuclear Information System (INIS)

Green, A.

2003-01-01

Human exposure to ultraviolet radiation (UVR) comes largely from sunlight, although a small proportion of people receive high dose UVR from artificial sources. The causal link between solar UVR and the keratinocyte cancers, basal cell carcinomas and squamous cell carcinomas of the skin, is well-established based on a large body of observational and experimental evidence. UVR damages molecules such as DNA directly and this is the principal mechanism of carcinogenesis, though other mechanisms such as immunosuppression and interaction with viruses may also be involved. People are also exposed to another form of nonionising radiation, radiofrequency radiation (RFR), through occupation, the community environment from base stations, and through use of cellular telephones and related communications devices. However, unlike UVR, the relationship between RFR and cancer is far from clear. The main tumours that have been investigated to date are brain tumours and leukaemia but assessing the RFR exposure pathway to such cancers poses many methodological challenges for epidemiologists. Refinements to measurement of exposure are the major urgent need, and the lack of evidence regarding carcinogenic effects of RFR in experimental settings complicates the assessment. Further insights into the links between RFR and chronic disease such as cancer are likely in the next few years however when results of several large-scale epidemiological studies now in train around the world become available

RADIOFREQUENCY AND MICROWAVE RADIATION HEALTH EFFECTS AND OCCUPATIONAL EXPOSURE

Directory of Open Access Journals (Sweden)

Ivana Damnjanović

2011-12-01

Full Text Available In the recent years, there have been considerable discussion and concern about the possible hazards of RF/MW radiation. More recently, the growth and development in personal mobile communications have focused attention on the frequencies associated with this technology. A number of studies have examined the health effects of RF/MW electromagnetic fields (EMFs, originating from occupational exposure, hobbies, or residence near the radio or television transmitters. Particularly controversial are the biophysical mechanisms by which these RF fields may affect biological systems. General health effects reviews explore possible carcinogenic, reproductive and neurological effects. Health effects by exposure source have been observed in radar traffic devices, wireless communications with cellular phones, radio transmission, and magnetic resonance imaging (MRI. Several epidemiological surveys have suggested associations with non-specific complaints such as headache, tiredness, sleep disturbance, loss of memory, and dizziness. These findings, which echo reports of illness associated with other types of radiofrequency (RF radiation, relate not only to the use of mobile phones, but also to residence near the mobile phone base stations and other settings involving occupational exposure. The biological effects suggest that some precautions are necessary, and preventive approaches are highly recommended. Further researches are required to give more information about the effects of microwave radiation on our health, especially in occupational setting and professionally exposed workers.

Biophysical evaluation of radiofrequency electromagnetic field effects on male reproductive pattern.

Science.gov (United States)

Kesari, Kavindra Kumar; Kumar, Sanjay; Nirala, Jayprakash; Siddiqui, Mohd Haris; Behari, Jitendra

2013-03-01

There are possible hazardous health effects of exposure to radiofrequency electromagnetic radiations emitted from mobile phone on the human reproductive pattern. It is more effective while keeping mobile phones in pocket or near testicular organs. Present review examines the possible concern on radio frequency radiation interaction and biological effects such as enzyme induction, and toxicological effects, including genotoxicity and carcinogenicity, testicular cancer, and reproductive outcomes. Testicular infertility or testicular cancer due to mobile phone or microwave radiations suggests an increased level of reactive oxygen species (ROS). Though generation of ROS in testis has been responsible for possible toxic effects on physiology of reproduction, the reviews of last few decades have well established that these radiations are very harmful and cause mutagenic changes in reproductive pattern and leads to infertility. The debate will be focused on bio-interaction mechanism between mobile phone and testicular cancer due to ROS formation. This causes the biological damage and leads to several changes like decreased sperm count, enzymatic and hormonal changes, DNA damage, and apoptosis formation. In the present review, physics of mobile phone including future research on various aspects has been discussed.

Null bactericidal effect of ultraviolet radiation emitted by LEDs.

Directory of Open Access Journals (Sweden)

Francisco Alcántara Muñoz

2016-11-01

Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

Evaluation of cellular effects of pulsed and continuous wave radiofrequency radiation

International Nuclear Information System (INIS)

Pavicic, Ivan; Trosic, Ivancica

2008-01-01

proliferation was determined by cell counts for each hour of exposure during five post-exposure days. To identify colony-forming ability, cells were cultivated in concentration of 40 cells/mL and incubated as above. Colony forming ability was defined by colony counts on the 7 th post-exposure day for each hour of exposure. In comparison to the controls, growth curve shows that proliferation ability of CW irradiated cells significantly decrease after 3 hours of exposure on the 3rd post-exposure day. PW exposed cell samples showed significant decrease after 3 hours of exposure on the 2nd and 3rd post-exposure day. CFA of CW and PW exposed cells did not significantly differ from the matched controls. The applied radiofrequency fields have shown similar effect on cell culture growth and CFA. Under the comparable conditions of exposure, pulsed radiofrequency radiation can be more effective in producing biological effects than continuous radiofrequency radiation. (author)

Radiofrequency radiation: safe working practices in the Royal Australian Air Force

International Nuclear Information System (INIS)

Joyner, K.H.; Stone, K.R.

1988-01-01

The Royal Australian Air Force (RAAF) has long recognised the value of its work force and the need to preserve their health and wellbeing to achieve operational objectives. The Directorate of Air Force Safety (DAFS) is required by the Chief of the Air Staff to take all measures possible to prevent accidents and incidents in the RAAF, under the provisions of the Defence Instruction, 'Air Force Safety and Occupational Health Policy'. Consequently, the RAAF has exercised a pragmatic approach to radiofrequency radiation (RFR) and has always adopted and implemented strict exposure standards. DAFS receives technical advice on RFR from the Directorate of Telecommunications Engineering (DTELENG) and on occupational health from the Directorate General of Air Force Health Services (DGAFHS)

Assessment of Radio-Frequency Radiation Exposure Level from Selected Mobile Base Stations (MBS) in Lokoja, Kogi State, Nigeria

OpenAIRE

Nwankwo, U. J. Victor; Jibiri, N. N.; Dada, S. S.; Onugba, A. A.; Ushie, P.

2012-01-01

The acquisition and use of mobile phone is tremendously increasing especially in developing countries, but not without a concern. The greater concern among the public is principally over the proximity of mobile base stations (MBS) to residential areas rather than the use of handsets. In this paper, we present an assessment of Radio-Frequency (RF) radiation exposure level measurements and analysis of radiation power density (in W/sq m) from mobile base stations relative to radial distance (in ...

Cytogenetic Damages Induced by Chronic Exposure to Microwave Non-Ionizing Radiofrequency Fields

Directory of Open Access Journals (Sweden)

Boris Đinđić

2013-12-01

Full Text Available Non-ionizing radiation has a significant and positive impact on modern society through a number of uses. There is increasing public concern regarding the health risks of radio-frequency (RF radiation, particularly that produced by mobile phones. Concern regarding the potential risks of exposure to EMFs has led to many epidemiological investigations, but the effects of EMF exposure on human and other mammalian cells are still unclear. One of the most frequently asked questions about the effects of microwave radiation on biological systems is whether they produce genotoxic effects and could be there a possible link with oncogenic processes. It is most difficult to get accurate and reproducible results for the studies that tell us most about the effects of EMF on humans. Based on some “weak” evidence suggesting an association between exposure to radiofrequency fields (RF emitted from mobile phones and two types of brain cancer, glioma and acoustic neuroma, the International Agency for Research on Cancer has classified RF as ‘possibly carcinogenic to humans’ in group 2B. Literature results suggest that pulsed microwaves from working environment can be the cause of genetic and cell alterations. Taken together, the increased frequency of DNA damages, increased intensity of oxydative stress and production of reactive oxygen species as well as prolonged disruption in DNA repair mechanisms could be possible mechanisms for microwave induced cytogenetic damages even at low-level electromagnetic fields. Although there were contradictory results about harmful effects of electromagnetic fields we recommend that the mobile phone should be kept as far as possible from the body during conversations and also during usual daily activities to reduce the absorption of radiation by cells. In addition, the appropriate intake of antioxidant-rich food or drugs may be helpful for preventing the genotoxic effects that could be caused by mobile phone use.

Assessment of occupational exposure to radiofrequency fields and radiation

International Nuclear Information System (INIS)

Cooper, T. G.; Allen, S. G.; Blackwell, R. P.; Litchfield, I.; Mann, S. M.; Pope, J. M.; Van Tongeren, M. J. A.

2004-01-01

The use of personal monitors for the assessment of exposure to radiofrequency fields and radiation in potential future epidemiological studies of occupationally exposed populations has been investigated. Data loggers have been developed for use with a commercially available personal monitor and these allowed personal exposure records consisting of time-tagged measurements of electric and magnetic field strength to be accrued over extended periods of the working day. The instrumentation was worn by workers carrying out tasks representative of some of their typical daily activities at a variety of radio sites. The results indicated significant differences in the exposures of workers in various RF environments. A number of measures of exposure have been examined with a view to assessing possible exposure metrics for epidemiological studies. There was generally a good correlation between a given measure of electric field strength and the same measure of magnetic field strength. (authors)

Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

Energy Technology Data Exchange (ETDEWEB)

Aerts, Sam, E-mail: sam.aerts@intec.ugent.be; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

2013-10-15

In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km{sup 2}. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an

Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

International Nuclear Information System (INIS)

Aerts, Sam; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

2013-01-01

In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km 2 . In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an

Neutron emission from 9Be nucleus under the action of β+ and γ radiation emitted in radioactive decay

International Nuclear Information System (INIS)

Vo Dak Bang; Gangrskij, Yu.P.; Miller, M.B.; Mikhajlov, L.V.; Fam Zui Khien; Kharisov, I.F.

1980-01-01

The neutron yield from the 9 Be nucleus under the action of beta and gamma-radiation emitted at the radiative decay of 11 C, 62 Cu, 66 Ga, 74 Br isotopes is measured. These isotopes differ essentially by the emitted radiation spectra. The contribution of various processes ((γ, n)-reactions, inelastic scattering and positron nonradiative annihilation) to the neutron yield observed is determined [ru

Measurement and Analysis of Radio-frequency Radiation Exposure Level from Different Mobile Base Transceiver Stations in Ajaokuta and Environs, Nigeria

OpenAIRE

Ushie, P. O.; Nwankwo, Victor U. J.; Bolaji, Ayinmode; Osahun, O. D.

2013-01-01

We present the result of a preliminary assessment of radio-frequency radiation exposure from selected mobile base stations in Ajaokuta environs. The Power density of RF radiation within a radial distance of 125m was measured. Although values fluctuated due to the influence of other factors, including wave interference from other electromagnetic sources around reference base stations, we show from analysis that radiation exposure level is below the standard limit (4.5W/sqm for 900MHz and 9W/sq...

Cytogenetic investigation of subjects professionally exposed to radiofrequency radiation.

Science.gov (United States)

Maes, Annemarie; Van Gorp, Urbain; Verschaeve, Luc

2006-03-01

Nowadays, virtually everybody is exposed to radiofrequency radiation (RFR) from mobile phone base station antennas or other sources. At least according to some scientists, this exposure can have detrimental health effects. We investigated cytogenetic effects in peripheral blood lymphocytes from subjects who were professionally exposed to mobile phone electromagnetic fields in an attempt to demonstrate possible RFR-induced genetic effects. These subjects can be considered well suited for this purpose as their RFR exposure is 'normal' though rather high, and definitely higher than that of the 'general population'. The alkaline comet assay, sister chromatid exchange (SCE) and chromosome aberration tests revealed no evidence of RFR-induced genetic effects. Blood cells were also exposed to the well known chemical mutagen mitomycin C in order to investigate possible combined effects of RFR and the chemical. No cooperative action was found between the electromagnetic field exposure and the mutagen using either the comet assay or SCE test.

World Health Organization, radiofrequency radiation and health - a hard nut to crack (Review).

Science.gov (United States)

Hardell, Lennart

2017-08-01

In May 2011 the International Agency for Research on Cancer (IARC) evaluated cancer risks from radiofrequency (RF) radiation. Human epidemiological studies gave evidence of increased risk for glioma and acoustic neuroma. RF radiation was classified as Group 2B, a possible human carcinogen. Further epidemiological, animal and mechanistic studies have strengthened the association. In spite of this, in most countries little or nothing has been done to reduce exposure and educate people on health hazards from RF radiation. On the contrary ambient levels have increased. In 2014 the WHO launched a draft of a Monograph on RF fields and health for public comments. It turned out that five of the six members of the Core Group in charge of the draft are affiliated with International Commission on Non-Ionizing Radiation Protection (ICNIRP), an industry loyal NGO, and thus have a serious conflict of interest. Just as by ICNIRP, evaluation of non-thermal biological effects from RF radiation are dismissed as scientific evidence of adverse health effects in the Monograph. This has provoked many comments sent to the WHO. However, at a meeting on March 3, 2017 at the WHO Geneva office it was stated that the WHO has no intention to change the Core Group.

Low power radiofrequency electromagnetic radiation for the treatment of pain due to osteoarthritis of the knee

Directory of Open Access Journals (Sweden)

U. Santosuosso

2011-09-01

Full Text Available Different techniques have been used in some rheumatic diseases to induce a therapeutic effect by heating deep tissues. These techniques are commonly known as ‘thermotherapy’ (1-4. It should be observed that adequate heating of deep tissues cannot be obtained by conduction or convection of heat because the skin and subcutaneous fat are good thermal insulators and because heating is reduced by blood flow in superficial vessels. Heating of deep tissues can instead be obtained by conversion of other forms of energy into heat. Conversion heat is generated by different types of radiations absorbed by deep tissues: when radiation interacts with tissues, some energy is converted into heat. High power radiofrequency electromagnetic radiation (RF, which produces strong thermal energy, has been widely applied in medicine for ablative procedures (5-7.

Radiative flux emitted by a burning PMMA slab

International Nuclear Information System (INIS)

Parent, G; Acem, Z; Collin, A; Berfroi, R; Boulet, P; Pizzo, Y; Mindykowski, P; Kaiss, A; Porterie, B

2012-01-01

The degradation of a PMMA sample has been studied based on experimental results obtained for the radiation emission by a burning slab. Observations of the infrared emission perpendicular to the plate, in the range where the optically thin flame is weakly emitting, indicate a plate temperature close to 680 K which is an indication on the surface temperature during the degradation process. Observations from the side allow a flame characterization without the plate emission superimposition. This is a promising way for evaluating data regarding the flame characteristics: temperature, gaz concentration and soot volumetric fraction.

Geometric radiation exchange factors for axial radiative transfer in an LWR core filled with absorbing-emitting gases

International Nuclear Information System (INIS)

Chan, S.H.; Cho, D.H.

1984-01-01

A reactor core filled with an emitting-absorbing mixture (like steam, hydrogen gas and fission gases) is considered. Analysis is provided to evaluate axial radiative heat exchange of a rod bundle with a nonuniform axial temperature distribution. The necessary radiation exchange shape factors (geometric mean absorptance, emittance and transmittance) between segments of the complex rod bundle arrangement are presented. They are applicable to arbitrary sizes of segments, well suited for numerical computations

Potential health risks due to telecommunications radiofrequency radiation exposures in Lagos State Nigeria.

Science.gov (United States)

Aweda, M A; Ajekigbe, A T; Ibitoye, A Z; Evwhierhurhoma, B O; Eletu, O B

2009-01-01

The global system mobile telecommunications system (GSM) which was recently introduced in Nigeria is now being used by over 40 million people in Nigeria. The use of GSM is accompanied with exposure of the users to radiofrequency radiation (RFR), which if significant, may produce health hazards. This is the reason why many relevant national and international organizations recommended exposure limits to RFR and why it is made compulsory for GSM handsets to indicate the maximum power output as a guide to potential consumers. This study was conducted to measure the RFR output power densities (S) from the most commonly used GSM handsets used in Lagos State and compare with the limit recommended for safety assessment. Over 1100 most commonly used handsets of different makes and models as well as wireless phones were sampled and studied in all over the local government areas of the State. An RFR meter, Electrosmog from LESSEMF USA was used for the measurements. The handsets were assessed for health risks using the reference value of 9 Wm(-2) as recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The range of the S-values obtained varied from a minimum of 1.294 0.101 Wm(-2) with Siemens model R228 to a maximum of 16.813 +/- 0.094 Wm(-2) with Samsung model C140*. The results from wireless telephones showed very low S-values ranging from a minimum of 0.024 +/- 0.001 Wm(-2) with HUAWEI and ST CDMA 1 to a maximum of 0.093 +/- 0.002 Wm(-2) with HISENSE. The results showed that the population in Lagos State may be at risk due to significant RFR exposures resulting principally from the use of GSM. Quite a number of handsets emit power above the ICNIRP recommended value. Measured RFR power close to Radio and Television masts and transmitters are within tolerable limits in most cases, only that the public should not reside or work close to RFR installations. Phone calls with GSM should be restricted to essential ones while youths and children

International radiofrequency standards

International Nuclear Information System (INIS)

Lincoln, J.

2001-01-01

Of the various radiofrequency standards in use around the world, many are based on or similar to the Guidelines published by ICNIRP (The International Commission on Non-ionising Radiation Protection). This organisation is a working group operating in co-operation with the Environmental Health division of the World Health Organisation (WHO). This paper presents a very brief overview of current international standards, beginning with a summary of the salient points of the ICNIRP Guidelines. It should be remembered that these are guidelines only and do not exist as a separate standard. Copyright (2001) Australasian Radiation Protection Society Inc

An evaluation of safety guidelines to restrict exposure to stray radiofrequency radiation from short-wave diathermy units

Energy Technology Data Exchange (ETDEWEB)

Shields, Nora [School of Physiotherapy, La Trobe University, Victoria 3086 (Australia); O' Hare, Neil [Department of Medical Physics and Bioengineering, St James' s Hospital, Dublin 8 (Ireland); Gormley, John [School of Physiotherapy, Trinity College Dublin, Trinity Centre for Health Sciences, St James' s Hospital, Dublin 8 (Ireland)

2004-07-07

Short-wave diathermy (SWD), a form of radiofrequency radiation used therapeutically by physiotherapists, may be applied in continuous (CSWD) or pulsed (PSWD) mode using either capacitive or inductive methods. Stray radiation emitted by these units may exceed exposure guidelines close to the equipment. Discrepant guidelines exist on a safe distance from an operating unit for operators and other personnel. Stray electric (E-field) and magnetic (H-field) field strengths from 10 SWD units in six departments were examined using a PMM 8053 meter and two isotropic probes (EP-330, HP-032). A 5 l saline phantom completed the patient circuit. Measurements were recorded in eight directions between 0.5 m and 2 m at hip and eye levels while the units operated at maximum output and data compared to current guidelines. Results found stray fields from capacitive CSWD fell below operator limits at 2 m (E-field 4.8-39.8 V/m; H-field 0.015-0.072 A/m) and at 1 m for inductive CSWD (E-field 0-36 V/m; H-field 0.01-0.065 A/m). Capacitive PSWD fields fell below the limits at 1.5 m (E-field 1.2-19.9 V/m; H-field 0.002-0.045 A/m) and at 1m for inductive PSWD (E-field 0.7-4.0 V/m; H-field 0.009-0.03 A/m). An extra 0.5 m was required before fields fell below the guidelines for other personnel. These results demonstrate, under a worst case scenario, emissions from SWD exceed the guidelines for operators at distances currently recommended as safe. Future guidelines should include recommendations for personnel other than physiotherapists.

An evaluation of safety guidelines to restrict exposure to stray radiofrequency radiation from short-wave diathermy units

International Nuclear Information System (INIS)

Shields, Nora; O'Hare, Neil; Gormley, John

2004-01-01

Short-wave diathermy (SWD), a form of radiofrequency radiation used therapeutically by physiotherapists, may be applied in continuous (CSWD) or pulsed (PSWD) mode using either capacitive or inductive methods. Stray radiation emitted by these units may exceed exposure guidelines close to the equipment. Discrepant guidelines exist on a safe distance from an operating unit for operators and other personnel. Stray electric (E-field) and magnetic (H-field) field strengths from 10 SWD units in six departments were examined using a PMM 8053 meter and two isotropic probes (EP-330, HP-032). A 5 l saline phantom completed the patient circuit. Measurements were recorded in eight directions between 0.5 m and 2 m at hip and eye levels while the units operated at maximum output and data compared to current guidelines. Results found stray fields from capacitive CSWD fell below operator limits at 2 m (E-field 4.8-39.8 V/m; H-field 0.015-0.072 A/m) and at 1 m for inductive CSWD (E-field 0-36 V/m; H-field 0.01-0.065 A/m). Capacitive PSWD fields fell below the limits at 1.5 m (E-field 1.2-19.9 V/m; H-field 0.002-0.045 A/m) and at 1m for inductive PSWD (E-field 0.7-4.0 V/m; H-field 0.009-0.03 A/m). An extra 0.5 m was required before fields fell below the guidelines for other personnel. These results demonstrate, under a worst case scenario, emissions from SWD exceed the guidelines for operators at distances currently recommended as safe. Future guidelines should include recommendations for personnel other than physiotherapists

Assessment of radiofrequency radiation within the vicinity of some GSM base stations in Ghana

International Nuclear Information System (INIS)

Deatanyah, P.; Amoako, J. K.; Fletcher, J. J.; Asiedu, G. O.; Adjei, D. N.; Dwapanyin, G. O.; Amoatey, E. A.

2012-01-01

A radiofrequency (RF) electromagnetic radiation safety survey had been carried out at public access points in 46 towns with 76 Global Systems for Mobile communication cell sites in two major cities in Ghana. The objective was to determine the levels of RF field in residential areas, schools and market places, and compare the measured results with the guidelines set by the International Commission of Non-Ionising Radiation (ICNIRP). Measurements were made with log-periodic antenna coupled with spectrum analyzer. The results varied from 0.85 to 1.07 mW m -2 and 0.78 to 1.19 mW m -2 for the transmission frequencies of 900 and 1800 MHz, respectively. The result generally shows a compliance with the ICNIRP limit of 0.024 % but was 108 times higher than a similar survey carried out in Ghana 2 y ago. (authors)

Induction of adaptive response in human blood lymphocytes exposed to radiofrequency radiation.

Science.gov (United States)

Sannino, Anna; Sarti, Maurizio; Reddy, Siddharth B; Prihoda, Thomas J; Vijayalaxmi; Scarfì, Maria Rosaria

2009-06-01

The incidence of micronuclei was evaluated to assess the induction of an adaptive response to non-ionizing radiofrequency (RF) radiation in peripheral blood lymphocytes collected from five different human volunteers. After stimulation with phytohemagglutinin for 24 h, the cells were exposed to an adaptive dose of 900 MHz RF radiation used for mobile communications (at a peak specific absorption rate of 10 W/kg) for 20 h and then challenged with a single genotoxic dose of mitomycin C (100 ng/ml) at 48 h. Lymphocytes were collected at 72 h to examine the frequency of micronuclei in cytokinesis-blocked binucleated cells. Cells collected from four donors exhibited the induction of adaptive response (i.e., responders). Lymphocytes that were pre-exposed to 900 MHz RF radiation had a significantly decreased incidence of micronuclei induced by the challenge dose of mitomycin C compared to those that were not pre-exposed to 900 MHz RF radiation. These preliminary results suggested that the adaptive response can be induced in cells exposed to non-ionizing radiation. A similar phenomenon has been reported in cells as well as in animals exposed to ionizing radiation in several earlier studies. However, induction of adaptive response was not observed in the remaining donor (i.e., non-responder). The incidence of micronuclei induced by the challenge dose of mitomycin C was not significantly different between the cells that were pre-exposed and unexposed to 900 MHz RF radiation. Thus the overall data indicated the existence of heterogeneity in the induction of an adaptive response between individuals exposed to RF radiation and showed that the less time-consuming micronucleus assay can be used to determine whether an individual is a responder or non-responder.

Combined Effect of Ambient Temperature with Radiofrequency Electromagnetic Radiation in Rabbit

International Nuclear Information System (INIS)

Kim, Jin Kyu; Choi, Dae Seong; Komarova, Ludmila N.; Petin, Vladislav G.

2010-01-01

There has been an increasing interest in synergistic effects observed after combined action of various agents. Many studies have shown that numerous physical and chemical agents combined with hyperthermia can interact in a synergistic manner when the effect produced by both agents used in combination exceeded the expected results from simple summation of the every effect produced by heat and the particular agent. I t was found that ambient temperature had a profound effect on the thermoregulatory responses to radiofrequency electromagnetic radiation (RFR) in various animals and humans. An extensive quantitative investigation of synergistic interaction of ambient temperature and microwaves has been published for rabbit heating. I t would be of interest to estimate whether or not the general features of the combined action revealed with unicellular organisms can be expressed for animals exposed to microwave power combined with a higher environmental temperature.

Exposure to 1800 MHz radiofrequency electromagnetic radiation induces oxidative DNA base damage in a mouse spermatocyte-derived cell line.

Science.gov (United States)

Liu, Chuan; Duan, Weixia; Xu, Shangcheng; Chen, Chunhai; He, Mindi; Zhang, Lei; Yu, Zhengping; Zhou, Zhou

2013-03-27

Whether exposure to radiofrequency electromagnetic radiation (RF-EMR) emitted from mobile phones can induce DNA damage in male germ cells remains unclear. In this study, we conducted a 24h intermittent exposure (5 min on and 10 min off) of a mouse spermatocyte-derived GC-2 cell line to 1800 MHz Global System for Mobile Communication (GSM) signals in GSM-Talk mode at specific absorption rates (SAR) of 1 W/kg, 2 W/kg or 4 W/kg. Subsequently, through the use of formamidopyrimidine DNA glycosylase (FPG) in a modified comet assay, we determined that the extent of DNA migration was significantly increased at a SAR of 4 W/kg. Flow cytometry analysis demonstrated that levels of the DNA adduct 8-oxoguanine (8-oxoG) were also increased at a SAR of 4 W/kg. These increases were concomitant with similar increases in the generation of reactive oxygen species (ROS); these phenomena were mitigated by co-treatment with the antioxidant α-tocopherol. However, no detectable DNA strand breakage was observed by the alkaline comet assay. Taking together, these findings may imply the novel possibility that RF-EMR with insufficient energy for the direct induction of DNA strand breaks may produce genotoxicity through oxidative DNA base damage in male germ cells. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

Radiofrequency catheter ablation in the treatment of cardiac arrhythmias (first of two parts)

International Nuclear Information System (INIS)

Kou, W.H; Morady, F.

1997-01-01

The intravenous radiofrequency catheter inside cardiac s chambers, for inspect signals intracardiac s and to encourage, has been developed as diagnostic tool with the purpose to search arrhythmias physiology and physiopathology.Many energy sources has been used: direct energy, radiofrequency 11-15, laser 6,17, and microwave 18,19. A comparison between radiofrequency and electric energy shock has been described in cardiac arrhythmias treatment, in the present article. It has been tested the radiation biological effects and risk in Wolff Parkinson White patients as well as doctors who handling the fluoroscopy for image during the radiofrequency ablation. Has been described the following techniques: Catheter ablation radiofrequency slow way and fast way

Mössbauer forward scattering spectra of ferromagnets in radio-frequency magnetic field

Directory of Open Access Journals (Sweden)

A. Ya. Dzyublik

2012-03-01

Full Text Available The transmission of Mössbauer radiation through a thick ferromagnetic crystal, subjected to the radio-frequency (rf magnetic field, is studied. A quantum-mechanical dynamical scattering theory is developed, taking into account both the periodical reversals of the magnetic field at the nuclei and their coherent vibrations. The Mössbauer forward scattering (FS spectra of the weak ferromagnet FeBO3 exposed to the rf field are measured. It is discovered that the coherent gamma wave in the crystal, interacting with Mössbauer nuclei, absorbs or emits only couples of the rf photons. As a result, the FS spectra consist of equidistant lines spaced by twice the frequency of the rf field in contrast to the absorption spectra. Our experimental data and calculations well agree if we assume that the hyperfine field at the nuclei in FeBO3 periodically reverses and there are no coherent vibrations.

The 2100MHz radiofrequency radiation of a 3G-mobile phone and the DNA oxidative damage in brain.

Science.gov (United States)

Sahin, Duygu; Ozgur, Elcin; Guler, Goknur; Tomruk, Arın; Unlu, Ilhan; Sepici-Dinçel, Aylin; Seyhan, Nesrin

2016-09-01

We aimed to evaluate the effect of 2100MHz radiofrequency radiation emitted by a generator, simulating a 3G-mobile phone on the brain of rats during 10 and 40 days of exposure. The female rats were randomly divided into four groups. Group I; exposed to 3G modulated 2100MHz RFR signal for 6h/day, 5 consecutive days/wk for 2 weeks, group II; control 10 days, were kept in an inactive exposure set-up for 6h/day, 5 consecutive days/wk for 2 weeks, group III; exposed to 3G modulated 2100MHz RFR signal for 6h/day, 5 consecutive days/wk for 8 weeks and group IV; control 40 days, were kept in an inactive exposure set-up for 6h/day, 5 consecutive days/wk for 8 weeks. After the genomic DNA content of brain was extracted, oxidative DNA damage (8-hydroxy-2'deoxyguanosine, pg/mL) and malondialdehyde (MDA, nmoL/g tissue) levels were determined. Our main finding was the increased oxidative DNA damage to brain after 10 days of exposure with the decreased oxidative DNA damage following 40 days of exposure compared to their control groups. Besides decreased lipid peroxidation end product, MDA, was observed after 40 days of exposure. The measured decreased quantities of damage during the 40 days of exposure could be the means of adapted and increased DNA repair mechanisms. Copyright © 2016 Elsevier B.V. All rights reserved.

Optical radiation emitted by a silver surface bombarded by low-energy electrons

International Nuclear Information System (INIS)

Miserey, F.; Lebon, P.; Septier, A.; Trehin, F.; Beaugrand, C.

1975-01-01

Thick silver targets are obtained on flat glass discs by evaporation in a UHV cell (p -10 torr) and their optical coefficients measured by ellipsometry. A field-emission electron gun bombards a limited region of the target, corresponding to the entry pupil of a light spectrometer. Radiation emitted in the domain 250-600nm is analyzed for both normal and parallel polarizations. Spectral distributions of photons are obtained by using a very sensitive counting device including a multi channel analyzer. First experimental results concerning optical radiation generated by 6keV electrons are reported and compared to Transition Radiation and Bremsstrahlung theoretical spectra [fr

Radiofrequency Neurotomy

Science.gov (United States)

... your specific symptoms. What you can expect Before radiofrequency neurotomy Let your doctor know if you take ... tobacco products the day of your procedure. During radiofrequency neurotomy Radiofrequency neurotomy is an outpatient procedure, so ...

Assessment of DNA sensitivity in peripheral blood leukocytes after occupational exposure to microwave radiation: the alkaline comet assay and chromatid breakage assay

International Nuclear Information System (INIS)

Garaj-Vrhovac, V.; Kopjar, N.

2002-01-01

The people of industrialised societies are continuously exposed to increasing levels of electromagnetic fields (EMF) emitted by various electrical installations and telecommunication systems. In recent years there has been growing interest in the health effects of the electromagnetic radiation's designated extremely low frequency (ELF) and radiofrequency radiation (RFR). It is known that exposure to microwave radiation has different biological effects on eye, the nervous system and its function, circulatory and the reproductive system. Available data on cytogenetic consequences of microwave exposure on the induction of chromosome damage are sometimes contradictory, mostly because of different experimental conditions of in vitro and in vivo studies. However, in occupationally exposed persons elevated levels of DNA damage as expressed by means of cytogenetic endpoints were observed. Positive results in induction of micronuclei are also reported after in vitro exposure to microwave radiation on human lymphocytes. It has been suggested that exposure to radiofrequency radiation may have genetic effects which predispose to the development of cancer, particularly lymphoma and leukaemia, and also birth defects such as Down's syndrome

High radiofrequency radiation at Stockholm Old Town: An exposimeter study including the Royal Castle, Supreme Court, three major squares and the Swedish Parliament

OpenAIRE

Hardell, Lennart; Carlberg, Michael; Koppel, Tarmo; Hedendahl, Lena

2017-01-01

Exposure to radiofrequency (RF) radiation was classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO in 2011. The exposure pattern is changing due to the rapid development of technology. Outdoor RF radiation level was measured during five tours in Stockholm Old Town in April, 2016 using the EME Spy 200 exposimeter with 20 predefined frequencies. The results were based on 10,437 samples in total. The mean level of the total RF radiation w...

Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

Science.gov (United States)

Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

2011-01-01

The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

Klebsiella pneumonia, a Microorganism that Approves the Non-linear Responses to Antibiotics and Window Theory after Exposure to Wi-Fi 2.4 GHz Electromagnetic Radiofrequency Radiation

Directory of Open Access Journals (Sweden)

Taheri M.

2015-09-01

Full Text Available Background: Drug resistance is widely believed to be an increasingly serious threat to global public health. We have previously reported that short term exposure of microorganisms to diagnostic ultrasound waves could significantly alter their sensitivity to antibiotics. In our previous studies, Klebsiella pneumoniae showed major differences in the sensitivity to antibiotics in exposed and non-exposed samples. This study was aimed at investigating the alteration of antibiotic resistance of Klebsiella pneumonia, after exposure to Wi-Fi 2.4 GHz electromagnetic radiofrequency radiation. Materials and Methods: In this in vitro study, three replicate agar plates were used for each test. The antibiotic susceptibility test was carried out using disc diffusion method on Mueller Hinton agar plates and the inhibition zones in both control and exposed groups were measured. A common Wi-Fi router was used in this study as the radiofrequency exposure source. Irradiated samples were exposed to Wi-Fi radiofrequency radiation for 3, 4.5 and 8 hours. Results: Statistically significant variations of sensitivity to antibiotics were found for all studied antibiotics after 4.5 hours of RF exposure, compared to non-exposed bacteria. Interestingly, the mean diameters of the inhibition zones after 3 hours of exposure were less than those exposed for 4.5 hours. Following this rise in the sensitivity to antibiotics, a fall was observed in the bacteria exposed for 8 hours for all studied antibiotics. Conclusion: The findings of this study show a statistically significant rise in the sensitivity of Klebsiella pneumoniae to different antibiotics after 4.5 hours of exposure to 2.4 GHz Wi-Fi radiation, followed by a fall after 8 hours of exposure. These observations can be interpreted by the concept of non-linearity in the responses of Klebsiella pneumoniae to different antibiotics after exposure to electromagnetic radiofrequency radiation. As in this study a minimum level of

Radiofrequency fields in our surroundings

International Nuclear Information System (INIS)

2011-01-01

In 2010, the National Radiation Protection Authority (NRPA) with the Post and Telecommunications Authority carried out a project where it is measured radiofrequency fields from various telecom systems in homes, kindergartens, schools, offices, and urban environments. Close to 99 percent of the measurement points were found values of less than one thousandth of the maximum. No values were near the limits. (AG)

Correlation of electromagnetic radiation emitted from coal or rock to supporting resistance

Energy Technology Data Exchange (ETDEWEB)

Jia, Hui-lin; Wang, En-yuan; Song, Xiao-yan; Zhang, Hong-jie; Li, Zhong-hui [China University of Mining & Technology, Xuzhou (China). School of Safety Engineering

2009-05-15

More accurate forecasting of rock burst might be possible from observations of electromagnetic radiation emitted in the mine. We analyzed experimental observations and field data from the Muchengjian coal mine to study the relationship between electromagnetic radiation signal intensity and stress during the fracturing of coal, or rock, and samples under load. The results show that the signal intensity is positively correlated with stress. In addition, we investigated the change in the electromagnetic radiation intensity, the supporting resistance in a real coal mine environment, and the coal or rock stress in the mining area. The data analysis indicates that: (1) electromagnetic radiation intensity can accurately reflect the distribution of stress in the mining area; and, (2) there is a correlation between electromagnetic radiation intensity and supporting resistance. The research has some practical guiding significance for rock burst forecasting and for the prevention of accidents in coal mines. 9 refs., 6 figs.

Cell oxidation-reduction imbalance after modulated radiofrequency radiation.

Science.gov (United States)

Marjanovic, Ana Marija; Pavicic, Ivan; Trosic, Ivancica

2015-01-01

Aim of this study was to evaluate an influence of modulated radiofrequency field (RF) of 1800 MHz, strength of 30 V/m on oxidation-reduction processes within the cell. The assigned RF field was generated within Gigahertz Transversal Electromagnetic Mode cell equipped by signal generator, modulator, and amplifier. Cell line V79, was irradiated for 10, 30, and 60 min, specific absorption rate was calculated to be 1.6 W/kg. Cell metabolic activity and viability was determined by MTT assay. In order to define total protein content, colorimetric method was used. Concentration of oxidised proteins was evaluated by enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) marked with fluorescent probe 2',7'-dichlorofluorescin diacetate were measured by means of plate reader device. In comparison with control cell samples, metabolic activity and total protein content in exposed cells did not differ significantly. Concentrations of carbonyl derivates, a product of protein oxidation, insignificantly but continuously increase with duration of exposure. In exposed samples, ROS level significantly (p < 0.05) increased after 10 min of exposure. Decrease in ROS level was observed after 30-min treatment indicating antioxidant defence mechanism activation. In conclusion, under the given laboratory conditions, modulated RF radiation might cause impairment in cell oxidation-reduction equilibrium within the growing cells.

"Triple M" Effect: A Proposed Mechanism to Explain Increased Dental Amalgam Microleakage after Exposure to Radiofrequency Electromagnetic Radiation.

Science.gov (United States)

Mortazavi, Gh; Mortazavi, S A R; Mehdizadeh, A R

2018-03-01

A large body of evidence now indicates that the amount of mercury released from dental amalgam fillings can be significantly accelerated by exposure to radiofrequency electromagnetic fields (RF-EMFs) such as common mobile phones and magnetic resonance imaging (MRI). Studies performed on the increased microleakage of dental amalgam restorations after exposure to RF-EMFs have further supported these findings. Although the accelerated microleakage induced by RF-EMFs is clinically significant, the entire mechanisms of this phenomenon are not clearly understood. In this paper, we introduce "Triple M" effect, a new evidence-based theory which can explain the accelerated microleakage of dental amalgam fillings after exposure to different sources of electromagnetic radiation. Based on this theory, there are saliva-filled tiny spaces between amalgam and the tooth. Exposure of the oral cavity to RF-EMFs increases the energy of these small amounts of saliva. Due to the small mass of saliva in these tiny spaces, a small amount of energy will be required for heating. Moreover, reflection of the radiofrequency radiation on the inner walls of the tiny spaces causes interference which in turn produces some "hot spots" in these spaces. Finally, formation of gas bubbles in response to increased temperature and very rapid expansion of these bubbles will accelerate the microleakage of amalgam. Experiments that confirm the validity of this theory are discussed.

Measurement of radiofrequency fields

International Nuclear Information System (INIS)

Leonowich, J.A.

1992-05-01

We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs

Temperature responsive porous silicon nanoparticles for cancer therapy - spatiotemporal triggering through infrared and radiofrequency electromagnetic heating.

Science.gov (United States)

Tamarov, Konstantin; Xu, Wujun; Osminkina, Liubov; Zinovyev, Sergey; Soininen, Pasi; Kudryavtsev, Andrey; Gongalsky, Maxim; Gaydarova, Azha; Närvänen, Ale; Timoshenko, Victor; Lehto, Vesa-Pekka

2016-11-10

One critical functionality of the carrier system utilized in targeted drug delivery is its ability to trigger the release of the therapeutic cargo once the carrier has reached its target. External triggering is an alluring approach as it can be applied in a precise spatiotemporal manner. In the present study, we achieved external triggering through the porous silicon (PSi) nanoparticles (NPs) by providing a pulse of infrared or radiofrequency radiation. The NPs were grafted with a temperature responsive polymer whose critical temperature was tailored to be slightly above 37°C. The polymer coating improved the biocompatibility of the NPs significantly in comparison with their uncoated counterparts. Radiation induced a rapid temperature rise, which resulted in the collapse of the polymer chains facilitating the cargo release. Both infrared and radiofrequency radiation were able to efficiently trigger the release of the encapsulated drug in vitro and induce significant cell death in comparison to the control groups. Radiofrequency radiation was found to be more efficient in vitro, and the treatment efficacy was verified in vivo in a lung carcinoma (3LL) mice model. After a single intratumoral administration of the carrier system combined with radiofrequency radiation, there was clear suppression of the growth of the carcinoma and a prolongation of the survival time of the animals. The temperature responsive (TR) polymer grafted on the surface of porous silicon nanoparticles (PSi NPs) changes its conformation in response to the heating induced by infrared or radiofrequency radiation. The conformation change allows the loaded doxorubicin to escape from the pores, achieving controlled drug release from TR PSi NPs, which displayed efficacy against malignant cells both in vitro and in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

Continuum radiation emitted from transition metals under ion bombardment

International Nuclear Information System (INIS)

El Boujlaidi, A.; Kaddouri, A.; Ait El Fqih, M.; Hammoum, K.; Aouchiche, H.

2012-01-01

Optical emission of transition metals has been studied during 5 keV Kr + ions bombardment within and without oxygen atmosphere in the colliding chamber. The observed spectra consist of a series of discrete lines superimposed on a broad continuum. Generally, the emission intensity was influenced by the presence of oxygen giving rise to transient effects as well as to an increase in the line intensity. The behaviours of spectral lines were successfully explained in term of electron-transfer process between the excited sputtered atom and the solid surface. In this work, we have focused our study on the continuous radiation emitted during ion bombardment. The experimental results suggest that the continuum emission depends on the nature of metal and very probably related to its electronic structure. The collective deactivation of 3d-shell electrons appears to play a role in the emission of this radiation. The observed enhancement in the presence of oxygen is probably due to a significant contribution of the oxide molecules. (authors)

Radiofrequency Ablation Effectively Treated Focal Recurrence of Mesothelioma.

Science.gov (United States)

Nakamura, Akifumi; Takuwa, Teruhisa; Hashimoto, Masaki; Kondo, Nobuyuki; Takaki, Haruyuki; Fujiwara, Masayuki; Yamakado, Koichiro; Hasegawa, Seiki

2018-02-01

A 55-year-old man with malignant pleural mesothelioma underwent multimodality treatment comprising induction chemotherapy followed by extrapleural pneumonectomy and radiation therapy. After 2.5 years, focal recurrence occurred, with computed tomography revealing a tumor in the left cardiophrenic angle. Surgery was considered a problem for the patient because of the previous extrapleural pneumonectomy and difficult tumor location. Radiofrequency ablation was thus performed; the course was uneventful, and there was no recurrence. Radiofrequency ablation should be considered an option to treat recurrence of malignant pleural mesothelioma. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Effects of radiation emitted from visual display terminals on the oral health status

International Nuclear Information System (INIS)

Kazem, H.H.

2008-01-01

This study was designed to investigate the effects of exposure to radiation emitted from visual display terminals (VDTs) on the oral health status; a cross sectional study was carried out on 100 participants both males and females with age ranging between 22- 40 years working in various places in Cairo. They were divided into two groups; the first consists of 50 subjects working in front of VDTs eight hours min. daily, min. 5 days/ week, 2 years or more, and the other group 50 subjects working away from any VDTs. Both groups were subjected to both oral and dental examinations, including soft tissues assessment by using gingival index (GI) and hard tissues assessment by using decayed, missed, filled (DMF) index. Saliva analysis was done including ph analysis by ph meter cyberscan 500 and trace elements analysis by ion chromatography and salivary immunoglobulin A (sIgA) analysis by ELISA, body temperature by using digital thermometer. The values were compared between both groups and also between before and after exposure in the exposed group. The results demonstrated that the difference in the mean values of either GI or DMF or ph or anions and cations or sIgA levels between exposed and non exposed groups or even between before and after exposure in the exposed group was found to be statistically insignificant. On the other hand there were significant changes in the mean values of body temperature between exposed and non-exposed group and also between before and after exposure in the exposed group. Accordingly, within the limits of this study we can conclude that radiation emitted from VDTs affects body temperature, but do not have any effect on oral health including; hard or soft tissues or salivary components. This might be explained by the radiation with very low energy emitted from VDTs

Effects of radiation emitted from visual display terminals on the oral health status

Energy Technology Data Exchange (ETDEWEB)

Kazem, H H [National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

2008-07-01

This study was designed to investigate the effects of exposure to radiation emitted from visual display terminals (VDTs) on the oral health status; a cross sectional study was carried out on 100 participants both males and females with age ranging between 22- 40 years working in various places in Cairo. They were divided into two groups; the first consists of 50 subjects working in front of VDTs eight hours min. daily, min. 5 days/ week, 2 years or more, and the other group 50 subjects working away from any VDTs. Both groups were subjected to both oral and dental examinations, including soft tissues assessment by using gingival index (GI) and hard tissues assessment by using decayed, missed, filled (DMF) index. Saliva analysis was done including ph analysis by ph meter cyberscan 500 and trace elements analysis by ion chromatography and salivary immunoglobulin A (sIgA) analysis by ELISA, body temperature by using digital thermometer. The values were compared between both groups and also between before and after exposure in the exposed group. The results demonstrated that the difference in the mean values of either GI or DMF or ph or anions and cations or sIgA levels between exposed and non exposed groups or even between before and after exposure in the exposed group was found to be statistically insignificant. On the other hand there were significant changes in the mean values of body temperature between exposed and non-exposed group and also between before and after exposure in the exposed group. Accordingly, within the limits of this study we can conclude that radiation emitted from VDTs affects body temperature, but do not have any effect on oral health including; hard or soft tissues or salivary components. This might be explained by the radiation with very low energy emitted from VDTs.

Impact of radiofrequency radiation on DNA damage and antioxidants in peripheral blood lymphocytes of humans residing in the vicinity of mobile phone base stations.

Science.gov (United States)

Zothansiama; Zosangzuali, Mary; Lalramdinpuii, Miriam; Jagetia, Ganesh Chandra

2017-01-01

Radiofrequency radiations (RFRs) emitted by mobile phone base stations have raised concerns on its adverse impact on humans residing in the vicinity of mobile phone base stations. Therefore, the present study was envisaged to evaluate the effect of RFR on the DNA damage and antioxidant status in cultured human peripheral blood lymphocytes (HPBLs) of individuals residing in the vicinity of mobile phone base stations and comparing it with healthy controls. The study groups matched for various demographic data including age, gender, dietary pattern, smoking habit, alcohol consumption, duration of mobile phone use and average daily mobile phone use. The RF power density of the exposed individuals was significantly higher (p base stations, showed significantly (p base station/s. The analysis of various antioxidants in the plasma of exposed individuals revealed a significant attrition in glutathione (GSH) concentration (p < 0.01), activities of catalase (CAT) (p < 0.001) and superoxide dismutase (SOD) (p < 0.001) and rise in lipid peroxidation (LOO) when compared to controls. Multiple linear regression analyses revealed a significant association among reduced GSH concentration (p < 0.05), CAT (p < 0.001) and SOD (p < 0.001) activities and elevated MN frequency (p < 0.001) and LOO (p < 0.001) with increasing RF power density.

Comparison of GSM Modulated and CW Radiofrequency Radiation on Cells

International Nuclear Information System (INIS)

Pavicic, I.; Marjanovic, A.M.; Trosic, I.

2011-01-01

The aim of our study was to evaluate and compare effect of global system of mobile (GSM) modulation and continuous wave (CW) radiofrequency radiation (RF) on proliferation ability and viability of V79 Chinese hamster lung cells. Previously prepared samples of cells in culture were exposed for 1, 2 and 3 hours both to 915 MHz GSM modulated and to 935 MHz CW RF field in gigahertz transversal electromagnetic mode cell (GTEM-cell). Electric field strength for cells exposed to GSM modulation was set at 10 V/m and for CW exposed cells was 8.2 V/m. Average specific absorption rate (SAR) was calculated to be for GSM 0.23 W/kg and for CW 0.12 W/kg. V79 samples were plated in concentration of 1x10 4 cells/mL. Cell proliferation was determined by cell counts for each hour of exposure during five post-exposure days. Trypan blue exclusion test was used to determine cell viability. In comparison to control cell samples, proliferation of GSM irradiated cells showed significant decrease after 3 hours of exposure on the second and third post-exposure day. CW exposed cell samples showed significant decrease after 3 hours of exposure on the third post-exposure day. Viability of GSM and CW exposed cells did not significantly differ from matched control cell samples. Both applied RF fields have shown similar effect on cell culture growth, and cell viability of V79 cell line. In addition, applied GSM modulated RF radiation demonstrate bigger influence on proliferation of cells. (author)

Potential health risks due to telecommunications radiofrequency ...

African Journals Online (AJOL)

Background: The global system mobile telecommunications system (GSM) which was recently introduced in Nigeria is now being used by over 40 million people in Nigeria. The use of GSM is accompanied with exposure of the users to radiofrequency radiation (RFR), which if significant, may produce health hazards. This is ...

Toxicologic study of electromagnetic radiation emitted by television and video display screens and cellular telephones on chickens and mice

International Nuclear Information System (INIS)

Bastide, M.; Youbicier-Simo, B.J.; Lebecq, J.C.; Giaimis, J.; Youbicier-Simo, B.J.

2001-01-01

The effects of continuous exposure of chick embryos and young chickens to the electromagnetic fields (EMFs) emitted by video display units (VDUs) and GSM cell phone radiation, either the whole spectrum emitted or attenuated by a copper gauze, were investigated. Permanent exposure to the EMFs radiated by a VDU was associated with significantly increased fetal loss (47-68%) and markedly depressed levels of circulating specific antibodies (lgG), corticosterone and melatonin. We have also shown that under chronic exposure conditions, GSM cell phone radiation was harmful to chick embryos, stressful for healthy mice and, in this species, synergistic with cancer insofar as it depleted stress hormones. The same pathological results were observed after substantial reduction of the microwaves radiated from the cell phone by attenuating them with a copper gauze. (author)

Effect of Exposure to 900 MHz GSM Mobile Phone Radiofrequency Radiation on Estrogen Receptor Methylation Status in Colon Cells of Male Sprague Dawley Rats

Science.gov (United States)

Mokarram, P.; Sheikhi, M.; Mortazavi, S.M.J.; Saeb, S.; Shokrpour, N.

2017-01-01

Background: Over the past several years, the rapidly increasing use of mobile phones has raised global concerns about the biological effects of exposure to radiofrequency (RF) radiation. Numerous studies have shown that exposure to electromagnetic fields (EMFs) can be associated with effects on the nervous, endocrine, immune, cardiovascular, hematopoietic and ocular systems. In spite of genetic diversity, the onset and progression of cancer can be controlled by epigenetic mechanisms such as gene promoter methylation. There are extensive studies on the epigenetic changes of the tumor suppressor genes as well as the identification of methylation biomarkers in colorectal cancer. Some studies have revealed that genetic changes can be induced by exposure to RF radiation. However, whether or not RF radiation is capable of inducing epigenetic alteration has not been clarified yet. To date, no study has been conducted on the effect of radiation on epigenetic alterations in colorectal cancer (CRC). Several studies have also shown that methylation of estrogen receptor α (ERα), MYOD, MGMT, SFRP2 and P16 play an important role in CRC. It can be hypothesized that RF exposure can be a reason for the high incidence of CRC in Iran. This study aimed to investigate whether epigenetic pattern of ERα is susceptible to RF radiation and if RF radiation can induce radioadaptive response as epigenetic changes after receiving the challenge dose (γ-ray). Material and Method: 40 male Sprague-Dawley rats were divided into 4 equal groups (Group I: exposure to RF radiation of a GSM cell phone for 4 hours and sacrificed after 24 hours; Group II: RF exposure for 4 hours, exposure to Co-60 gamma radiation (3 Gy) after 24 hours and sacrificed after 72 hrs; Group III: only 3Gy gamma radiation; Group 4: control group). DNA from colon tissues was extracted to evaluate the methylation status by methylation specific PCR. Results: Our finding showed that exposure to GSM cell phone RF radiation was

Effect of Exposure to 900 MHz GSM Mobile Phone Radiofrequency Radiation on Estrogen Receptor Methylation Status in Colon Cells of Male Sprague Dawley Rats

Directory of Open Access Journals (Sweden)

Mokarram P.

2017-03-01

Full Text Available Background: Over the past several years, the rapidly increasing use of mobile phones has raised global concerns about the biological effects of exposure to radiofrequency (RF radiation. Numerous studies have shown that exposure to electromagnetic fields (EMFs can be associated with effects on the nervous, endocrine, immune, cardiovascular, hematopoietic and ocular systems. In spite of genetic diversity, the onset and progression of cancer can be controlled by epigenetic mechanisms such as gene promoter methylation. There are extensive studies on the epigenetic changes of the tumor suppressor genes as well as the identification of methylation biomarkers in colorectal cancer. Some studies have revealed that genetic changes can be induced by exposure to RF radiation. However, whether or not RF radiation is capable of inducing epigenetic alteration has not been clarified yet. To date, no study has been conducted on the effect of radiation on epigenetic alterations in colorectal cancer (CRC. Several studies have also shown that methylation of estrogen receptor α (ERα, MYOD, MGMT, SFRP2 and P16 play an important role in CRC. It can be hypothesized that RF exposure can be a reason for the high incidence of CRC in Iran. This study aimed to investigate whether epigenetic pattern of ERα is susceptible to RF radiation and if RF radiation can induce radioadaptive response as epigenetic changes after receiving the challenge dose (γ-ray. Material and Method: 40 male Sprague-Dawley rats were divided into 4 equal groups (Group I: exposure to RF radiation of a GSM cell phone for 4 hours and sacrificed after 24 hours; Group II: RF exposure for 4 hours, exposure to Co-60 gamma radiation (3 Gy after 24 hours and sacrificed after 72 hrs; Group III: only 3Gy gamma radiation; Group 4: control group. DNA from colon tissues was extracted to evaluate the methylation status by methylation specific PCR. Results: Our finding showed that exposure to GSM cell phone RF

Behavior and memory evaluation of Wistar rats exposed to 1·8 GHz radiofrequency electromagnetic radiation.

Science.gov (United States)

Júnior, Luiz Carlos de Caires; Guimarães, Ernesto da Silveira Goulart; Musso, Camila Manso; Stabler, Collin Turner; Garcia, Raúl Marcel González; Mourão-Júnior, Carlos Alberto; Andreazzi, Ana Eliza

2014-09-01

The development of communication systems has brought great social and economic benefits to society. As mobile phone use has become widespread, concerns have emerged regarding the potential adverse effects of radiofrequency electromagnetic radiation (RF-EMR) used by these devices. To verify potential effects of mobile phone radiation on the central nervous system (CNS) in an animal model. Male Wistar rats (60 days old) were exposed to RF-EMR from a Global System for Mobile (GSM) cell phone (1·8 GHz) for 3 days. At the end of the exposure, the following behavioral tests were performed: open field and object recognition. Our results showed that exposed animals did not present anxiety patterns or working memory impairment, but stress behavior actions were observed. Given the results of the present study, we speculate that RF-EMR does not promote CNS impairment, but suggest that it may lead to stressful behavioral patterns.

“Triple M” Effect: A Proposed Mechanism to Explain Increased Dental Amalgam Microleakage after Exposure to Radiofrequency Electromagnetic Radiation

Science.gov (United States)

Mortazavi, Gh.; Mortazavi, S.A.R.; Mehdizadeh, A.R.

2018-01-01

A large body of evidence now indicates that the amount of mercury released from dental amalgam fillings can be significantly accelerated by exposure to radiofrequency electromagnetic fields (RF-EMFs) such as common mobile phones and magnetic resonance imaging (MRI). Studies performed on the increased microleakage of dental amalgam restorations after exposure to RF-EMFs have further supported these findings. Although the accelerated microleakage induced by RF-EMFs is clinically significant, the entire mechanisms of this phenomenon are not clearly understood. In this paper, we introduce “Triple M” effect, a new evidence-based theory which can explain the accelerated microleakage of dental amalgam fillings after exposure to different sources of electromagnetic radiation. Based on this theory, there are saliva-filled tiny spaces between amalgam and the tooth. Exposure of the oral cavity to RF-EMFs increases the energy of these small amounts of saliva. Due to the small mass of saliva in these tiny spaces, a small amount of energy will be required for heating. Moreover, reflection of the radiofrequency radiation on the inner walls of the tiny spaces causes interference which in turn produces some “hot spots” in these spaces. Finally, formation of gas bubbles in response to increased temperature and very rapid expansion of these bubbles will accelerate the microleakage of amalgam. Experiments that confirm the validity of this theory are discussed. PMID:29732349

X-ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra

International Nuclear Information System (INIS)

Ostorero, L.; Moderski, R.; Stawarz, L.; Diaferio, A.; Kowalska, I.; Cheung, C.C.; Kataoka, J.; Begelman, M.C.; Wagner, S.J.

2010-01-01

In a dynamical-radiative model we recently developed to describe the physics of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate across the inner, kpc-sized region of the host galaxy, while the electron population of the expanding lobes evolves and emits synchrotron and inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the expanding lobes, and photoionized by the active nucleus, are responsible for the radio spectral turnover through free-free absorption (FFA) of the synchrotron photons. The model provides a description of the evolution of the GPS spectral energy distribution (SED) with the source expansion, predicting significant and complex high-energy emission, from the X-ray to the γ-ray frequency domain. Here, we test this model with the broad-band SEDs of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object (CSO) morphology, and show that: (i) the shape of the radio continuum at frequencies lower than the spectral turnover is indeed well accounted for by the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as non-thermal radiation produced via IC scattering of the local radiation fields off the lobe particles, providing a viable alternative to the thermal, accretion-disk dominated scenario. We also show that the relation between the hydrogen column densities derived from the X-ray (N H ) and radio (N HI ) data of the sources is suggestive of a positive correlation, which, if confirmed by future observations, would provide further support to our scenario of high-energy emitting lobes.

CASPER: Concordia Atmospheric SPectroscopy of Emitted Radiation

Science.gov (United States)

de Petris, M.; Catalano, A.; de Gregori, S.; Lamagna, L.; Lattanzi, V.; Luzzi, G.; Maoli, R.; Melchiorri, A.; Melchiorri, F.; Savini, G.; Vetrani, G. G.; Battistelli, E. S.; Valenziano, L.; Mandolesi, N.; Villa, F.; Cuttaia, F.; Ade, P. A. R.; Mauskopf, P.; Orlando, A.; Encrenaz, P.; Pardo, J. R.; Cernicharo, J.

CASPER (Concordia Atmospheric SPectroscopy of Emitted Radiation) is a spectrometer proposed for installation at Dome C, devoted to measurements of atmospheric emission in the spectral region between 180 μm and 3 mm (3 55 cm-1). This instrument will be able to perform continuous spectral sampling at different altitudes at angular scales of 1°. From the recorded data it is possible to extract atmospheric transmittance within 1% in the whole wide operating band, together with water vapour content and O{2} and O{3} concentrations. CASPER will allow us to characterize the site for future FIR/mm telescopes. Atmospheric data recorded by CASPER will allow for correction of astrophysical and cosmological observations without the need for telescope-specific procedures and further loss of observation time with more precision in the observations themselves. Calibration of ground-based telescopes on known sky sources is strongly affected by atmospheric absorption. CASPER has this as its primary goal. The spectrometer is based on a Martin-Puplett interferometer. Two data sampling solutions will be performed: phase modulation & fast scan strategy. Sky radiation is collected towards the interferometer by an optical setup that allows the field of view, to explore the full 0° div 90° range of elevation angles. With a low spurious polarization instrument, monitoring of polarized atmospheric contribution will be possible.

Intraoperative radio-frequency capacitive hyperthermia and radiation therapy for unresectable pancreatic cancer

International Nuclear Information System (INIS)

Nakazawa, M.; Yamashita, T.; Hashida, I.

1988-01-01

The authors have initiated intraoperative radiation therapy (IORT) and intraoperative radio-frequency capacitive hyperthermia (IOHT) for unresectable pancreatic cancer. After gastric (corpus) resection, IORT and IOHT were conducted and gastro-duodenostomy was performed IORT was delivered with 12 meV electron (25 Gy) and 10 MV Linac x-ray (7.5 Gy). IOHT was done with 13.56 MHz capacitive equipment aiming 43 0 C for over 30 min along with concurrent administration of 500 mg 5-FU. Five cases were heated by the conventional method and two additional cases were heated with a newly fabricated applicator. Attained temperatures monitored directly from tumor were 38.5 0 C-44.3 0 C (over 43 0 C in four cases, 40 0 C in one case, and below 40 0 C in two cass.) Pain relief was achieved in most cases. Using the new applicators, the authors could avoid unexpected hot spots and insufficient heating

Soil moisture estimation using reflected solar and emitted thermal infrared radiation

Science.gov (United States)

Jackson, R. D.; Cihlar, J.; Estes, J. E.; Heilman, J. L.; Kahle, A.; Kanemasu, E. T.; Millard, J.; Price, J. C.; Wiegand, C. L.

1978-01-01

Classical methods of measuring soil moisture such as gravimetric sampling and the use of neutron moisture probes are useful for cases where a point measurement is sufficient to approximate the water content of a small surrounding area. However, there is an increasing need for rapid and repetitive estimations of soil moisture over large areas. Remote sensing techniques potentially have the capability of meeting this need. The use of reflected-solar and emitted thermal-infrared radiation, measured remotely, to estimate soil moisture is examined.

Synchrotron radiation and its various uses in physics, chemistry and biology

Energy Technology Data Exchange (ETDEWEB)

Farge, Y [Laboratoire pour l' Utilisation du Rayonnement Electromagnetique (LURE), Paris-11 Univ., 91 - Orsay (France)

1975-01-01

The synchrotron radiation emitted by synchrotrons or storage rings has exceptional properties: spectral continuity from X-rays to radiofrequencies, high intensity, focussed emission in the orbit plane, polarization, and time pulsed structure. The radiation is a unique tool for spectroscopic investigations in the far uv or X-rays on atoms, molecules, or solids. Time resolved spectroscopy in the nano and subnanosecond range is now available in a very broad wavelength range. In the X-ray range, these sources are revolutionary because they are more powerful than the best X-ray tubes by two to four orders of magnitude; it will be very soon possible to do kinetic measurements with typical times of one second and less either by diffraction, scattering, or topography.

Comparative studies of the ITU-T prediction model for radiofrequency radiation emission and real time measurements at some selected mobile base transceiver stations in Accra, Ghana

International Nuclear Information System (INIS)

Obeng, S. O

2014-07-01

Recent developments in the electronics industry have led to the widespread use of radiofrequency (RF) devices in various areas including telecommunications. The increasing numbers of mobile base station (BTS) as well as their proximity to residential areas have been accompanied by public health concerns due to the radiation exposure. The main objective of this research was to compare and modify the ITU- T predictive model for radiofrequency radiation emission for BTS with measured data at some selected cell sites in Accra, Ghana. Theoretical and experimental assessment of radiofrequency exposures due to mobile base station antennas have been analysed. The maximum and minimum average power density measured from individual base station in the town was 1. 86µW/m2 and 0.00961µW/m2 respectively. The ITU-T Predictive model power density ranged between 6.40mW/m 2 and 0.344W/m 2 . Results obtained showed a variation between measured power density levels and the ITU-T predictive model. The ITU-T model power density levels decrease with increase in radial distance while real time measurements do not due to fluctuations during measurement. The ITU-T model overestimated the power density levels by a factor l0 5 as compared to real time measurements. The ITU-T model was modified to reduce the level of overestimation. The result showed that radiation intensity varies from one base station to another even at the same distance. Occupational exposure quotient ranged between 5.43E-10 and 1.89E-08 whilst general public exposure quotient ranged between 2.72E-09 and 9.44E-08. From the results, it shows that the RF exposure levels in Accra from these mobile phone base station antennas are below the permitted RF exposure limit to the general public recommended by the International Commission on Non-Ionizing Radiation Protection. (au)

Optical spectroscopy and microscopy of radiation-induced light-emitting point defects in lithium fluoride crystals and films

Science.gov (United States)

Montereali, R. M.; Bonfigli, F.; Menchini, F.; Vincenti, M. A.

2012-08-01

Broad-band light-emitting radiation-induced F2 and F3+ electronic point defects, which are stable and laser-active at room temperature in lithium fluoride crystals and films, are used in dosimeters, tuneable color-center lasers, broad-band miniaturized light sources and novel radiation imaging detectors. A brief review of their photoemission properties is presented, and their behavior at liquid nitrogen temperatures is discussed. Some experimental data from optical spectroscopy and fluorescence microscopy of these radiation-induced point defects in LiF crystals and thin films are used to obtain information about the coloration curves, the efficiency of point defect formation, the effects of photo-bleaching processes, etc. Control of the local formation, stabilization, and transformation of radiation-induced light-emitting defect centers is crucial for the development of optically active micro-components and nanostructures. Some of the advantages of low temperature measurements for novel confocal laser scanning fluorescence microscopy techniques, widely used for spatial mapping of these point defects through the optical reading of their visible photoluminescence, are highlighted.

Radiation and the New Zealand community : a scientific overview

International Nuclear Information System (INIS)

1998-01-01

This book is intended to give information and perspective on the risks associated with the widespread use of radiations of different types in modern society. Chapter 1 introduces the radiations that are discussed. It raises questions, which the book seeks to answer about risks and benefits of radiation applications, and discusses the meaning of the oft-quoted expression n uclear free . Chapter 2 briefly describes the nature of radioactivity and the types of radioactive decay processes and emitted radiations most commonly observed. Chapter 3 traces from the perspective of historical developments the use of x-rays and radioactive materials in medical practice. Chapter 4 outlines the wide range of applications of radioactive materials in x-ray equipment in industry with particular emphasis on applications in New Zealand. Chapter 5 is devoted to a description of food irradiation. Chapter 6 is devoted to non-ionizing radiation applications, with separate sections on ultraviolet radiation, visible radiation, lasers, infrared radiation, microwave and radiofrequency radiation ,with some particular reference to cellular phone systems, extremely low frequency electric and magnetic fields and ultrasound. Chapter 7 concludes with an outline of the system of controls on ionizing radiation sources in New Zealand. (author). 7 appendices

Exposure of Ontario workers to radiofrequency fields from dielectric heaters

International Nuclear Information System (INIS)

Bitran, M.E.; Nishio, J.M.; Charron, D.E.

1992-01-01

As part of a program to assess and reduce the exposure of Ontario workers to non-ionizing radiations, stray electric and magnetic fields from 383 dielectric heaters were measured in 71 industrial establishments from 1988 to 1990. This represents a population of over 800 workers potentially exposed to radiofrequency (RE) electromagnetic fields. Electric and magnetic field strengths at the head, waist, and thigh levels of the operators, corrected by duty cycle, are presented for the different heater types surveyed. Worker exposure data and compliance with Ontario radiofrequency exposure guidelines are discussed. (author)

Risk of Ionizing Radiation in Women of Childbearing Age undergoing Radiofrequency Ablation

Energy Technology Data Exchange (ETDEWEB)

Lima, Gustavo Glotz de, E-mail: gglima.pesquisa@gmail.com; Gomes, Daniel Garcia; Gensas, Caroline Saltz; Simão, Mariana Fernandez; Rios, Matheus N.; Pires, Leonardo Martins; Kruse, Marcelo Lapa; Leiria, Tiago Luiz Luz [Instituto de Cardiologia, Fundação Universitária de Cardiologia, Porto Alegre, RS (Brazil)

2013-11-15

The International Commission of Radiology recommends a pregnancy screening test to all female patients of childbearing age who will undergo a radiological study. Radiation is known to be teratogenic and its effect is cumulative. The teratogenic potential starts at doses close to those used during these procedures. The prevalence of positive pregnancy tests in patients undergoing electrophysiological studies and/or catheter ablation in our midst is unknown. To evaluate the prevalence of positive pregnancy tests in female patients referred for electrophysiological study and/or radiofrequency ablation. Cross-sectional study analyzing 2,966 patients undergoing electrophysiological study and/or catheter ablation, from June 1997 to February 2013, in the Institute of Cardiology of Rio Grande do Sul. A total of 1490 procedures were performed in women, of whom 769 were of childbearing age. All patients were screened with a pregnancy test on the day before the procedure. Three patients tested positive, and were therefore unable to undergo the procedure. The prevalence observed was 3.9 cases per 1,000 women of childbearing age. Because of their safety and low cost, pregnancy screening tests are indicated for all women of childbearing age undergoing radiological studies, since the degree of ionizing radiation needed for these procedures is very close to the threshold for teratogenicity, especially in the first trimester, when the signs of pregnancy are not evident.

Risk of Ionizing Radiation in Women of Childbearing Age undergoing Radiofrequency Ablation

International Nuclear Information System (INIS)

Lima, Gustavo Glotz de; Gomes, Daniel Garcia; Gensas, Caroline Saltz; Simão, Mariana Fernandez; Rios, Matheus N.; Pires, Leonardo Martins; Kruse, Marcelo Lapa; Leiria, Tiago Luiz Luz

2013-01-01

The International Commission of Radiology recommends a pregnancy screening test to all female patients of childbearing age who will undergo a radiological study. Radiation is known to be teratogenic and its effect is cumulative. The teratogenic potential starts at doses close to those used during these procedures. The prevalence of positive pregnancy tests in patients undergoing electrophysiological studies and/or catheter ablation in our midst is unknown. To evaluate the prevalence of positive pregnancy tests in female patients referred for electrophysiological study and/or radiofrequency ablation. Cross-sectional study analyzing 2,966 patients undergoing electrophysiological study and/or catheter ablation, from June 1997 to February 2013, in the Institute of Cardiology of Rio Grande do Sul. A total of 1490 procedures were performed in women, of whom 769 were of childbearing age. All patients were screened with a pregnancy test on the day before the procedure. Three patients tested positive, and were therefore unable to undergo the procedure. The prevalence observed was 3.9 cases per 1,000 women of childbearing age. Because of their safety and low cost, pregnancy screening tests are indicated for all women of childbearing age undergoing radiological studies, since the degree of ionizing radiation needed for these procedures is very close to the threshold for teratogenicity, especially in the first trimester, when the signs of pregnancy are not evident

Freescale Sdn Bhd: Monitoring Radiofrequency Assessment

International Nuclear Information System (INIS)

Wan Saffiey Wan Abdullah; Noor Ezati Shuib; Rozaimah Abdul Rahim; Pasupathy, E.; Muhammad Yusri Yahaya

2015-01-01

Freescale Semiconductor (M) Sdn Bhd, requested the assistance of Malaysian Nuclear Agency (Nuclear Malaysia) to conduct an electromagnetic radiation (Radiofrequency Radiation) measurements around its facilities at Freescale Semiconductor (M) Sdn Bhd, 2, Jalan SS8/2, Sungai Wai Free Industrial Zone, 47300 Petaling Jaya, Selangor. Nuclear Agency Non-Ionising Radiation (NIR) Group carried out the measurement on 30th July 2012. In carrying out the work, the Group was assisted by Mr Daniel. The main objectives of the measurement were to assess the presence of electromagnetic radiation (RF field) in an accessible work places within and around the facilities and to advise the company on outcomes of the assessment and measurement based on international recommendations of standard guidelines issued by Malaysian Communication and Multimedia Commission (MCMC) and International Commission on Non-Ionising Radiation Protection (ICNIRP). (author)

High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

Science.gov (United States)

Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

2018-04-01

High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

Preliminary Assessment of Radiofrequency Radiation Exposure Level, From Mobile Base Stations in Ajaokuta and Environs, Kogi State, Nigeria

International Nuclear Information System (INIS)

Ushie, P. O.; Nwankwo, U.J.V.; Osahun, O. D.; Ayinmode, B.

2013-01-01

We present the result of a preliminary assessment of radio-frequency radiation exposure from selected mobile base stations in Ajaokuta environs using radio frequency (RF) meter (electromoge meter). The Power density of RF radiation within a radial distance of 125m was measured. Although values fluctuated due to the influence of unavoidable factors suspected to be interferences from other electromagnetic sources around reference base stations, we show from analysis that radiation exposure level is far below the standard limit (10W/cm 2 or 10 7 μW/m 2 ) set by the International Commission on Non-ionizing Radiation Protection (ICNIRP) regulatory agencies. The assessment was done in about ten (10) base stations in Ajaokuta, Kogi state. The position and elevation of the base stations were noted using a global positioning system (GPS) to ascertain the position of such stations on the world map. It was discovered that the limit of exposure to radio frequency radiation set by International Commission on Non-ionizing, Radiation Protection (ICNIRP) of 900MHz band expressed in the same unit as 10W/cm 2 or 10 7 μW/m 2 was not exceeded, the values were also influenced by some inevitable factors. Positions of most of the stations are sited close to homes.

Temperature mapping and thermal dose calculation in combined radiation therapy and 13.56 MHz radiofrequency hyperthermia for tumor treatment

Science.gov (United States)

Kim, Jung Kyung; Prasad, Bibin; Kim, Suzy

2017-02-01

To evaluate the synergistic effect of radiotherapy and radiofrequency hyperthermia therapy in the treatment of lung and liver cancers, we studied the mechanism of heat absorption and transfer in the tumor using electro-thermal simulation and high-resolution temperature mapping techniques. A realistic tumor-induced mouse anatomy, which was reconstructed and segmented from computed tomography images, was used to determine the thermal distribution in tumors during radiofrequency (RF) heating at 13.56 MHz. An RF electrode was used as a heat source, and computations were performed with the aid of the multiphysics simulation platform Sim4Life. Experiments were carried out on a tumor-mimicking agar phantom and a mouse tumor model to obtain a spatiotemporal temperature map and thermal dose distribution. A high temperature increase was achieved in the tumor from both the computation and measurement, which elucidated that there was selective high-energy absorption in tumor tissue compared to the normal surrounding tissues. The study allows for effective treatment planning for combined radiation and hyperthermia therapy based on the high-resolution temperature mapping and high-precision thermal dose calculation.

Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation.

Science.gov (United States)

Medeiros, Luisa Nascimento; Sanchez, Tanit Ganz

2016-01-01

Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR). Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity), and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Quantum dot superluminescent light emitting diodes: Ideal blackbody radiators?

Energy Technology Data Exchange (ETDEWEB)

Blazek, Martin; Elsaesser, Wolfgang [Institute of Applied Physics, Darmstadt University of Technology (Germany); Hopkinson, Mark [Dept. E and E.E, University of Sheffield (United Kingdom); Krakowski, Michel [Alcatel Thales, III-V Lab. (France)

2008-07-01

Quantum dot (QD) superluminescent light emitting diodes (SLEDs) provide large optical bandwidths at desired wavelengths and are therefore promising devices for incoherent light application. The intensity noise behavior of QD SLEDs is of fundamental physical interest as it provides insight into the photon emission process. We performed high precision intensity noise measurements over several decades of optical output power. For low driving currents spontaneous emission leads to Shot Noise. For high currents we find excess noise behavior with Amplified Spontaneous Emission acting as the dominant source of noise. The QD SLEDs' noise can be described as blackbody radiation noise with a limited number of optical modes. It is therefore possible to identify the SLEDs' relevant intensity noise parameters.

Radiofrequency radiation at Stockholm Central Railway Station in Sweden and some medical aspects on public exposure to RF fields.

Science.gov (United States)

Hardell, Lennart; Koppel, Tarmo; Carlberg, Michael; Ahonen, Mikko; Hedendahl, Lena

2016-10-01

The Stockholm Central Railway Station in Sweden was investigated for public radiofrequency (RF) radiation exposure. The exposimeter EME Spy 200 was used to collect the RF exposure data across the railway station. The exposimeter covers 20 different radiofrequency bands from 88 to 5,850 MHz. In total 1,669 data points were recorded. The median value for total exposure was 921 µW/m2 (or 0.092 µW/cm2; 1 µW/m2=0.0001 µW/cm2) with some outliers over 95,544 µW/m2 (6 V/m, upper detection limit). The mean total RF radiation level varied between 2,817 to 4,891 µW/m2 for each walking round. High mean measurements were obtained for GSM + UMTS 900 downlink varying between 1,165 and 2,075 µW/m2. High levels were also obtained for UMTS 2100 downlink; 442 to 1,632 µW/m2. Also LTE 800 downlink, GSM 1800 downlink, and LTE 2600 downlink were in the higher range of measurements. Hot spots were identified, for example close to a wall mounted base station yielding over 95,544 µW/m2 and thus exceeding the exposimeter's detection limit. Almost all of the total measured levels were above the precautionary target level of 3-6 µW/m2 as proposed by the BioInitiative Working Group in 2012. That target level was one-tenth of the scientific benchmark providing a safety margin either for children, or chronic exposure conditions. We compare the levels of RF radiation exposures identified in the present study to published scientific results reporting adverse biological effects and health harm at levels equivalent to, or below those measured in this Stockholm Central Railway Station project. It should be noted that these RF radiation levels give transient exposure, since people are generally passing through the areas tested, except for subsets of people who are there for hours each day of work.

Decay Curves and Half-Lives of Gamma-Emitting States from a Study of Prompt Fission Gamma Radiation

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

1971-04-15

Measurements were made on the time distributions of the prompt gamma radiation emitted from fragments in the thermal-neutron induced fission of 235U. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fragments. In this way decay curves were obtained from which half-lives could be estimated. Time components with half-lives of 7.5, 18 and 60 ps were found and their relative intensities were calculated. Half-lives and associated intensities are in good agreement with earlier data from uranium and californium fission. Problems involved in this type of study are discussed. The collimator technique has proved to be effective for determination of half lives down to less than 10 ps

Combined Natural Convection and Radiation Heat Transfer of Various Absorbing-Emitting-Scattering Media in a Square Cavity

Directory of Open Access Journals (Sweden)

Xianglong Liu

2014-01-01

Full Text Available A numerical model is developed to simulate combined natural convection and radiation heat transfer of various anisotropic absorbing-emitting-scattering media in a 2D square cavity based on the discrete ordinate (DO method and Boussinesq assumption. The effects of Rayleigh number, optical thickness, scattering ratio, scattering phase function, and aspect ratio of square cavity on the behaviors of heat transfer are studied. The results show that the heat transfer of absorbing-emitting-scattering media is the combined results of radiation and natural convection, which depends on the physical properties and the aspect ratio of the cavity. When the natural convection becomes significant, the convection heat transfer is enhanced, and the distributions of NuR and Nuc along the walls are obviously distorted. As the optical thickness increases, NuR along the hot wall decreases. As the scattering ratio decreases, the NuR along the walls decreases. At the higher aspect ratio, the more intensive thermal radiation and natural convection are formed, which increase the radiation and convection heat fluxes. This paper provides the theoretical research for the optimal thermal design and practical operation of the high temperature industrial equipments.

Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

Science.gov (United States)

Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

1996-01-01

Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

Science.gov (United States)

Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Paval, Jaijesh; Kedage, Vivekananda; Bhat, M Shankaranarayana; Nayak, Satheesha; Bhat, P Gopalakrishna

2013-07-01

In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

The Precautionary Principle in the Context of Mobile Phone and Base Station Radiofrequency Exposures

OpenAIRE

Dolan, Mike; Rowley, Jack

2009-01-01

Background No health hazard has been established from exposure to radiofrequency fields up to the levels recommended by the International Commission on Non-Ionizing Radiation Protection. However, in response to public concern and the perceived level of scientific uncertainty, there are continuing calls for the application of the precautionary principle to radiofrequency exposures from mobile phones and base stations. Objective We examined the international evolution of calls for precautionary...

Evaluation of scattered radiation emitted from X-ray security scanners on occupational dose to airport personnel

International Nuclear Information System (INIS)

Dalah, Entesar; Fakhry, Angham; Mukhtar, Asma; Al Salti, Farah; Bader, May; Khouri, Sara; Al-Zahmi, Reem

2017-01-01

Based on security issues and regulations airports are provided with luggage cargo scanners. These scanners utilize ionizing radiation that in principle present health risks toward humans. The study aims to investigate the amount of backscatter produced by passenger luggage and cargo toward airport personnel who are located at different distances from the scanners. To approach our investigation a Thermo Electron Radeye-G probe was used to quantify the backscattered radiation measured in terms of dose-rate emitted from airport scanners, Measurements were taken at the entrance and exit positions of the X-ray tunnel at three different distances (0, 50, and 100 cm) for two different scanners; both scanners include shielding curtains that reduce scattered radiation. Correlation was demonstrated using the Pearson coefficient test. Measurements confirmed an inverse relationship between dose rate and distance. An estimated occupational accumulative dose of 0.88 mSv/y, and 2.04 mSv/y were obtained for personnel working in inspection of carry-on, and cargo, respectively. Findings confirm that the projected dose of security and engineering staff are being well within dose limits. - Highlights: • Backscattered radiation emitted from the airport security scanners is estimated. • Inverse relation observed between backscattered radiation and scanners distance. • Occupational dose for personnel inspecting the scanners were up to 2.04 mSv/y. • The projected dose of security and engineering staff are well within dose limits.

The synchrotron radiation and its various uses in physics, chemistry and biology

International Nuclear Information System (INIS)

Farge, Y.

1975-01-01

The synchrotron radiation emitted by synchrotrons or storage rings has exceptional properties: spectral continuity from X-rays to radiofrequencies, high intensity, focussed emission in the orbit plane, polarization, time pulsed structure. For the sake of these properties, this radiation is a unique tool for spectroscopic investigations in the far UV or X-rays on atoms, molecules or solids. Time resolved spectroscopy in the nano and subnanosecond range is now available in a very broad wavelength range. In the X-ray range, these sources are introducing a revolution because they are more powerfull than the best X-ray tubes by two to four orders of magnitude; it will be very soon possible to do kinetic measurements with typical times of one second and less either by diffraction, scattering or topography [fr

WORKSHOPS: Radiofrequency superconductivity

International Nuclear Information System (INIS)

Anon.

1992-01-01

In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991

WORKSHOPS: Radiofrequency superconductivity

Energy Technology Data Exchange (ETDEWEB)

Anon.

1992-01-15

In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991.

Fabrication and characterization of UV-emitting nanoparticles as novel radiation sensitizers targeting hypoxic tumor cells

Science.gov (United States)

Squillante, Michael R.; Jüstel, Thomas; Anderson, R. Rox; Brecher, Charles; Chartier, Daniel; Christian, James F.; Cicchetti, Nicholas; Espinoza, Sara; McAdams, Daniel R.; Müller, Matthias; Tornifoglio, Brooke; Wang, Yimin; Purschke, Martin

2018-06-01

Radiation therapy is one of the primary therapeutic techniques for treating cancer, administered to nearly two-thirds of all cancer patients. Although largely effective in killing cancer cells, radiation therapy, like other forms of cancer treatment, has difficulty dealing with hypoxic regions within solid tumors. The incomplete killing of cancer cells can lead to recurrence and relapse. The research presented here is investigating the enhancement of the efficacy of radiation therapy by using scintillating nanoparticles that emit UV photons. UV photons, with wavelengths between 230 nm and 280 nm, are able to inactivate cells due to their direct interaction with DNA, causing a variety of forms of damage. UV-emitting nanoparticles will enhance the treatment in two ways: first by generating UV photons in the immediate vicinity of cancer cells, leading to direct and oxygen-independent DNA damage, and second by down-converting the applied higher energy X-rays into softer X-rays and particles that are more efficiently absorbed in the targeted tumor region. The end result will be nanoparticles with a higher efficacy in the treatment of hypoxic cells in the tumor, filling an important, unmet clinical need. Our preliminary experiments show an increase in cell death using scintillating LuPO4:Pr nanoparticles over that achieved by the primary radiation alone. This work describes the fabrication of the nanoparticles, their physical characterization, and the spectroscopic characterization of the UV emission. The work also presents in vitro results that demonstrate an enhanced efficacy of cell killing with x-rays and a low unspecific toxicity of the nanoparticles.

Assessment of radiation emitted by the colour video monitors using a silicon surface-barrier detection system

International Nuclear Information System (INIS)

Tykva, R.; Sabol, J.

1998-01-01

About 5% of the commonly used colour monitors tested showed radiation levels on the screen surface approaching the dose rate of 5 μGy/h. There is practically no difference between 'low radiation' monitors and other monitors. The level of radiation emitted to the sides is generally higher than that of X-ray photons emerging from the surface of the screen. Although the contribution to the effective dose of a person exposed to radiation from the monitors may be below the limit set for the general public, the skin and eye lens dose may reach significant levels, taking into account some factors such as a high density of monitors in small rooms, short distance, long exposure time, etc. (M.D.)

Oxidative stress response in SH-SY5Y cells exposed to short-term 1800 MHz radiofrequency radiation.

Science.gov (United States)

Marjanovic Cermak, Ana Marija; Pavicic, Ivan; Trosic, Ivancica

2018-01-28

The exact mechanism that could explain the effects of radiofrequency (RF) radiation exposure at non-thermal level is still unknown. Increasing evidence suggests a possible involvement of reactive oxygen species (ROS) and development of oxidative stress. To test the proposed hypothesis, human neuroblastoma cells (SH-SY5Y) were exposed to 1800 MHz short-term RF exposure for 10, 30 and 60 minutes. Electric field strength within Gigahertz Transverse Electromagnetic cell (GTEM) was 30 V m -1 and specific absorption rate (SAR) was calculated to be 1.6 W kg -1 . Cellular viability was measured by MTT assay and level of ROS was determined by fluorescent probe 2',7'-dichlorofluorescin diacetate. Concentrations of malondialdehyde and protein carbonyls were used to assess lipid and protein oxidative damage and antioxidant activity was evaluated by measuring concentrations of total glutathione (GSH). After radiation exposure, viability of irradiated cells remained within normal physiological values. Significantly higher ROS level was observed for every radiation exposure time. After 60 min of exposure, the applied radiation caused significant lipid and protein damage. The highest GSH concentration was detected after 10 minute-exposure. The results of our study showed enhanced susceptibility of SH-SY5Y cells for development of oxidative stress even after short-term RF exposure.

Anthropogenic radiofrequency electromagnetic fields as an emerging threat to wildlife orientation.

Science.gov (United States)

Balmori, Alfonso

2015-06-15

The rate of scientific activity regarding the effects of anthropogenic electromagnetic radiation in the radiofrequency (RF) range on animals and plants has been small despite the fact that this topic is relevant to the fields of experimental biology, ecology and conservation due to its remarkable expansion over the past 20 years. Current evidence indicates that exposure at levels that are found in the environment (in urban areas and near base stations) may particularly alter the receptor organs to orient in the magnetic field of the earth. These results could have important implications for migratory birds and insects, especially in urban areas, but could also apply to birds and insects in natural and protected areas where there are powerful base station emitters of radiofrequencies. Therefore, more research on the effects of electromagnetic radiation in nature is needed to investigate this emerging threat. Copyright © 2015 Elsevier B.V. All rights reserved.

Radiofrequency Ablation of Lung Tumors

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z Radiofrequency Ablation (RFA) / Microwave Ablation (MWA) of Lung Tumors ... and Microwave Ablation of Lung Tumors? What are Radiofrequency and Microwave Ablation of Lung Tumors? Radiofrequency ablation, ...

Power output and efficiency of beta-emitting microspheres

International Nuclear Information System (INIS)

Cheneler, David; Ward, Michael

2015-01-01

Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire’s theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer. - Highlights: • Range-energy relationship for the beta particles in yttrium-90 is calculated. • Formalism for the semi-analytical calculation of self-absorption coefficients. • Energy-dependent self-absorption coefficient calculated for yttrium-90. • Flux rate of beta particles from a self-attenuating radioactive sphere is shown. • The efficiency of beta particle emitting radioactive microspheres is calculated

Radiofrequency radiation from nearby base stations gives high levels in an apartment in Stockholm, Sweden: A case report

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Hedendahl, Lena K.

2018-01-01

Exposure to radiofrequency (RF) radiation was classified in 2011 as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer of the World Health Organisation. Evidence of the risk of cancer risk has since strengthened. Exposure is changing due to the rapid development of technology resulting in increased ambient radiation. RF radiation of sufficient intensity heats tissues, but the energy is insufficient to cause ionization, hence it is called non-ionizing radiation. These non-thermal exposure levels have resulted in biological effects in humans, animals and cells, including an increased cancer risk. In the present study, the levels of RF radiation were measured in an apartment close to two groups of mobile phone base stations on the roof. A total of 74,531 measurements were made corresponding to ~83 h of recording. The total mean RF radiation level was 3,811 µW/m2 (range 15.2–112,318 µW/m2) for the measurement of the whole apartment, including balconies. Particularly high levels were measured on three balconies and 3 of 4 bedrooms. The total mean RF radiation level decreased by 98% when the measured down-links from the base stations for 2, 3 and 4 G were disregarded. The results are discussed in relation to the detrimental health effects of non-thermal RF radiation. Due to the current high RF radiation, the apartment is not suitable for long-term living, particularly for children who may be more sensitive than adults. For a definitive conclusion regarding the effect of RF radiation from nearby base stations, one option would be to turn them off and repeat the measurements. However, the simplest and safest solution would be to turn them off and dismantle them. PMID:29725476

Radiofrequency radiation from nearby base stations gives high levels in an apartment in Stockholm, Sweden: A case report.

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Hedendahl, Lena K

2018-05-01

Exposure to radiofrequency (RF) radiation was classified in 2011 as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer of the World Health Organisation. Evidence of the risk of cancer risk has since strengthened. Exposure is changing due to the rapid development of technology resulting in increased ambient radiation. RF radiation of sufficient intensity heats tissues, but the energy is insufficient to cause ionization, hence it is called non-ionizing radiation. These non-thermal exposure levels have resulted in biological effects in humans, animals and cells, including an increased cancer risk. In the present study, the levels of RF radiation were measured in an apartment close to two groups of mobile phone base stations on the roof. A total of 74,531 measurements were made corresponding to ~83 h of recording. The total mean RF radiation level was 3,811 µW/m 2 (range 15.2-112,318 µW/m 2 ) for the measurement of the whole apartment, including balconies. Particularly high levels were measured on three balconies and 3 of 4 bedrooms. The total mean RF radiation level decreased by 98% when the measured down-links from the base stations for 2, 3 and 4 G were disregarded. The results are discussed in relation to the detrimental health effects of non-thermal RF radiation. Due to the current high RF radiation, the apartment is not suitable for long-term living, particularly for children who may be more sensitive than adults. For a definitive conclusion regarding the effect of RF radiation from nearby base stations, one option would be to turn them off and repeat the measurements. However, the simplest and safest solution would be to turn them off and dismantle them.

Pulsed radiofrequency microwave fields around a quadrupole particle accelerator: measurement and safety evaluation

International Nuclear Information System (INIS)

Sachdev, R.N.; Swarup, G.; Rajan, K.K.; Joseph, L.

1996-01-01

Pulsed radiofrequency microwave radiation (RFMR) fields occur during the use of high power microwaves in plasma heating in fusion research, plasma and solid state diagnostics, particle accelerators and colliders, pump sources in lasers, material processing as well as in high power radars. This paper describes the experimental work done at Trombay for measurement of pulsed RFMR fields in the working area of a radiofrequency quadrupole (RFQ) accelerator with the use of a meter calibrated in continuous field and interprets the observed fields in the light of existing protection criteria for pulsed RFMR fields. (author)

The protective effect of autophagy on mouse spermatocyte derived cells exposure to 1800MHz radiofrequency electromagnetic radiation.

Science.gov (United States)

Liu, Kaijun; Zhang, Guowei; Wang, Zhi; Liu, Yong; Dong, Jianyun; Dong, Xiaomei; Liu, Jinyi; Cao, Jia; Ao, Lin; Zhang, Shaoxiang

2014-08-04

The increasing exposure to radiofrequency (RF) radiation emitted from mobile phone use has raised public concern regarding the biological effects of RF exposure on the male reproductive system. Autophagy contributes to maintaining intracellular homeostasis under environmental stress. To clarify whether RF exposure could induce autophagy in the spermatocyte, mouse spermatocyte-derived cells (GC-2) were exposed to 1800MHz Global System for Mobile Communication (GSM) signals in GSM-Talk mode at specific absorption rate (SAR) values of 1w/kg, 2w/kg or 4w/kg for 24h, respectively. The results indicated that the expression of LC3-II increased in a dose- and time-dependent manner with RF exposure, and showed a significant change at the SAR value of 4w/kg. The autophagosome formation and the occurrence of autophagy were further confirmed by GFP-LC3 transient transfection assay and transmission electron microscopy (TEM) analysis. Furthermore, the conversion of LC3-I to LC3-II was enhanced by co-treatment with Chloroquine (CQ), indicating autophagic flux could be enhanced by RF exposure. Intracellular ROS levels significantly increased in a dose- and time-dependent manner after cells were exposed to RF. Pretreatment with anti-oxidative NAC obviously decreased the conversion of LC3-I to LC3-II and attenuated the degradation of p62 induced by RF exposure. Meanwhile, phosphorylated extracellular-signal-regulated kinase (ERK) significantly increased after RF exposure at the SAR value of 2w/kg and 4w/kg. Moreover, we observed that RF exposure did not increase the percentage of apoptotic cells, but inhibition of autophagy could increase the percentage of apoptotic cells. These findings suggested that autophagy flux could be enhanced by 1800MHz GSM exposure (4w/kg), which is mediated by ROS generation. Autophagy may play an important role in preventing cells from apoptotic cell death under RF exposure stress. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Radiofrequency ablation of osteoid osteoma

NARCIS (Netherlands)

Vanderschueren, Geert Maria Joris Michael

2009-01-01

The main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the technical requirements needed for safe radiofrequency ablation and the clinical outcome after radiofrequency

Development of computational pregnant female and fetus models and assessment of radiation dose from positron-emitting tracers

Energy Technology Data Exchange (ETDEWEB)

Xie, Tianwu [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Southern Denmark, Department of Nuclear Medicine, Odense (Denmark)

2016-12-15

Molecular imaging using PET and hybrid (PET/CT and PET/MR) modalities nowadays plays a pivotal role in the clinical setting for diagnosis and staging, treatment response monitoring, and radiation therapy treatment planning of a wide range of oncologic malignancies. The developing embryo/fetus presents a high sensitivity to ionizing radiation. Therefore, estimation of the radiation dose delivered to the embryo/fetus and pregnant patients from PET examinations to assess potential radiation risks is highly praised. We constructed eight embryo/fetus models at various gestation periods with 25 identified tissues according to reference data recommended by the ICRP publication 89 representing the anatomy of the developing embryo/fetus. The developed embryo/fetus models were integrated into realistic anthropomorphic computational phantoms of the pregnant female and used for estimating, using Monte Carlo calculations, S-values of common positron-emitting radionuclides, organ absorbed dose, and effective dose of a number of positron-emitting labeled radiotracers. The absorbed dose is nonuniformly distributed in the fetus. The absorbed dose of the kidney and liver of the 8-week-old fetus are about 47.45 % and 44.76 % higher than the average absorbed dose of the fetal total body for all investigated radiotracers. For {sup 18}F-FDG, the fetal effective doses are 2.90E-02, 3.09E-02, 1.79E-02, 1.59E-02, 1.47E-02, 1.40E-02, 1.37E-02, and 1.27E-02 mSv/MBq at the 8th, 10th, 15th, 20th, 25th, 30th, 35th, and 38th weeks of gestation, respectively. The developed pregnant female/fetus models matching the ICRP reference data can be exploited by dedicated software packages for internal and external dose calculations. The generated S-values will be useful to produce new standardized dose estimates to pregnant patients and embryo/fetus from a variety of positron-emitting labeled radiotracers. (orig.)

On the radiation emitted by a particle falling into a black hole in the semi-relativistic approximation

International Nuclear Information System (INIS)

Coretti, C.; Ferrari, V.

1986-01-01

In this paper the limits of applicability of the semi-relativistic approximation for estimating the radiation emitted in processes of capture of particles by black holes are discussed. It is shown that it gives reliable estimates in the case of spherically symmetric black holes, but it fails in the case of rotating black holes

Adaptive response in human blood lymphocytes exposed to non-ionizing radiofrequency fields: resistance to ionizing radiation-induced damage.

Science.gov (United States)

Sannino, Anna; Zeni, Olga; Romeo, Stefania; Massa, Rita; Gialanella, Giancarlo; Grossi, Gianfranco; Manti, Lorenzo; Vijayalaxmi; Scarfì, Maria Rosaria

2014-03-01

The aim of this preliminary investigation was to assess whether human peripheral blood lymphocytes which have been pre-exposed to non-ionizing radiofrequency fields exhibit an adaptive response (AR) by resisting the induction of genetic damage from subsequent exposure to ionizing radiation. Peripheral blood lymphocytes from four healthy donors were stimulated with phytohemagglutinin for 24 h and then exposed for 20 h to 1950 MHz radiofrequency fields (RF, adaptive dose, AD) at an average specific absorption rate of 0.3 W/kg. At 48 h, the cells were subjected to a challenge dose (CD) of 1.0 or 1.5 Gy X-irradiation (XR, challenge dose, CD). After a 72 h total culture period, cells were collected to examine the incidence of micronuclei (MN). There was a significant decrease in the number of MN in lymphocytes exposed to RF + XR (AD + CD) as compared with those subjected to XR alone (CD). These observations thus suggested a RF-induced AR and induction of resistance to subsequent damage from XR. There was variability between the donors in RF-induced AR. The data reported in our earlier investigations also indicated a similar induction of AR in human blood lymphocytes that had been pre-exposed to RF (AD) and subsequently treated with a chemical mutagen, mitomycin C (CD). Since XR and mitomycin-C induce different kinds of lesions in cellular DNA, further studies are required to understand the mechanism(s) involved in the RF-induced adaptive response.

21 CFR 882.4725 - Radiofrequency lesion probe.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

Adaptive Response in Animals Exposed to Non-Ionizing Radiofrequency Fields: Some Underlying Mechanisms

Directory of Open Access Journals (Sweden)

Yi Cao

2014-04-01

Full Text Available During the last few years, our research group has been investigating the phenomenon of adaptive response in animals exposed to non-ionizing radiofrequency fields. The results from several separate studies indicated a significant increase in survival, decreases in genetic damage as well as oxidative damage and, alterations in several cellular processes in mice pre-exposed to radiofrequency fields and subsequently subjected to sub-lethal or lethal doses of γ-radiation or injected with bleomycin, a radiomimetic chemical mutagen. These observations indicated the induction of adaptive response providing the animals the ability to resist subsequent damage. Similar studies conducted by independent researchers in mice and rats have supported our observation on increased survival. In this paper, we have presented a brief review of all of our own and other independent investigations on radiofrequency fields-induced adaptive response and some underlying mechanisms discussed.

Radiofrequency fields in our surroundings; Radiofrekvente felt i vaare omgivelser

Energy Technology Data Exchange (ETDEWEB)

2011-07-01

In 2010, the National Radiation Protection Authority (NRPA) with the Post and Telecommunications Authority carried out a project where it is measured radiofrequency fields from various telecom systems in homes, kindergartens, schools, offices, and urban environments. Close to 99 percent of the measurement points were found values of less than one thousandth of the maximum. No values were near the limits. (AG)

Finite volume method for radiative heat transfer in an unstructured flow solver for emitting, absorbing and scattering media

International Nuclear Information System (INIS)

Gazdallah, Moncef; Feldheim, Véronique; Claramunt, Kilian; Hirsch, Charles

2012-01-01

This paper presents the implementation of the finite volume method to solve the radiative transfer equation in a commercial code. The particularity of this work is that the method applied on unstructured hexahedral meshes does not need a pre-processing step establishing a particular marching order to visit all the control volumes. The solver simply visits the faces of the control volumes as numbered in the hexahedral unstructured mesh. A cell centred mesh and a spatial differencing step scheme to relate facial radiative intensities to nodal intensities is used. The developed computer code based on FVM has been integrated in the CFD solver FINE/Open from NUMECA Int. Radiative heat transfer can be evaluated within systems containing uniform, grey, emitting, absorbing and/or isotropically or linear anisotropically scattering medium bounded by diffuse grey walls. This code has been validated for three test cases. The first one is a three dimensional rectangular enclosure filled with emitting, absorbing and anisotropically scattering media. The second is the differentially heated cubic cavity. The third one is the L-shaped enclosure. For these three test cases a good agreement has been observed when temperature and heat fluxes predictions are compared with references taken, from literature.

47 CFR 2.801 - Radiofrequency device defined.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency device defined. 2.801 Section 2... MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency device defined. As used in this part, a radiofrequency device is any device which in its operation is capable of...

Volatiles emitted from flowers by gamma-radiated and nonradiated Jasminum polyanthum Franch. in situ

International Nuclear Information System (INIS)

Christensen, L.P.; Jakobsen, H.B.; Kristiansen, K.; Moller, J.

1997-01-01

Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%), eugenol (3.5%), 2-methoxy-p-cresol (3.1%), linalool (3.0%), phenethyl acetate (2.1%), and (Z)3-hexenyl butyrate (1.9%). The strong scent of Pepita reduces its production potentialities as a pot plant, thus the possibility to reduce or modify the emission of volatiles from Pepita by mutagenesis was investigated. The average total yields of volatiles in Pepita were approximately 2800 ng flower-1 h-1, and in one gamma-radiated clone a significantly lower yield of 1050 ng flower-1 h-1 was found. The volatile profiles of the gamma-radiated plants were made up of the same 32 compounds found in Pepita. Significant differences in the headspace composition between Pepita and gamma-radiated plants were found for some of the major volatiles

Arthrography

Medline Plus

Full Text Available ... utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while ... any chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit ...

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while ... any chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit ...

MRI of the Chest

Medline Plus

Full Text Available ... utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while ... any chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while ... any chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while you ... chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit different ...

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while you ... chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit different ...

Arthrography

Medline Plus

Full Text Available ... ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while you ... chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit different ...

MRI of the Chest

Medline Plus

Full Text Available ... ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that naturally exist within the body while you ... chemical changes in the tissues. As the hydrogen atoms return to their usual alignment, they emit different ...

Stress and Fatigue in Operators Under Radiofrequency Electromagnetic Radiation and Shift Work

Directory of Open Access Journals (Sweden)

Vangelova K.

2014-12-01

Full Text Available The aim was to study the effect of radiofrequency electromagnetic radiation (EMR on stress indices, health complaints and fatigue of operators working fast-rotating extended shifts. Working conditions, job content, job control, social support, health complaints and fatigue were followed in 220 operators, 110 exposed to EMR and 110 control operators, matched by age and sex. The EMR was measured and time-weighted average (TWA was calculated. The excretion rates of stress hormones cortisol, adrenaline and noradrenaline were followed during the extended shifts in 36 operators, working at different levels of exposure and 24-hour exposure was calculated. The exposed group pointed more problems with the working conditions, including EMR, noise, currents and risk of accidents, more health complaints and higher level of fatigue. The most common health complaints were mental and physical exhaustion after work, pains in the chest, musculoskeletal complaints, headache, and apathy. High level EMR exposure (TWAmean = 3.10 μW/cm2, TWAmax = 137.00 μW/cm2 significantly increased the 24-hour excretion of cortisol and noradrenaline, whereas the increase of adrenaline excretion did not reach significance, as well as hormone excretion rates under low level exposure (TWAmean = 1.89 μW/cm2, TWAmax = 5.24 μW/cm2. In conclusion, higher number of health complaints, higher stress hormone excretion rates and fatigue were found in operators under EMR.

Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media

Science.gov (United States)

Stamnes, Knut; Tsay, S.-CHEE; Jayaweera, Kolf; Wiscombe, Warren

1988-01-01

The transfer of monochromatic radiation in a scattering, absorbing, and emitting plane-parallel medium with a specified bidirectional reflectivity at the lower boundary is considered. The equations and boundary conditions are summarized. The numerical implementation of the theory is discussed with attention given to the reliable and efficient computation of eigenvalues and eigenvectors. Ways of avoiding fatal overflows and ill-conditioning in the matrix inversion needed to determine the integration constants are also presented.

Predicting nurses' acceptance of radiofrequency identification technology.

Science.gov (United States)

Norten, Adam

2012-10-01

The technology of radiofrequency identification allows for the scanning of radiofrequency identification-tagged objects and individuals without line-of-sight requirements. Healthcare organizations use radiofrequency identification to ensure the health and safety of patients and medical personnel and to uncover inefficiencies. Although the successful implementation of a system incorporating radiofrequency identification technologies requires acceptance and use of the technology, some nurses using radiofrequency identification in hospitals feel like "Big Brother" is watching them. This predictive study used a theoretical model assessing the effect of five independent variables: privacy concerns, attitudes, subjective norms, controllability, and self-efficacy, on a dependent variable, nurses' behavioral intention to use radiofrequency identification. A Web-based questionnaire containing previously validated questions was answered by 106 US RNs. Multiple linear regression showed that all constructs together accounted for 60% of the variance in nurses' intention to use radiofrequency identification. Of the predictors in the model, attitudes provided the largest unique contribution when the other predictors in the model were held constant; subjective norms also provided a unique contribution. Privacy concerns, controllability, and self-efficacy did not provide a significant contribution to nurses' behavioral intention to use radiofrequency identification.

Conventional Radiofrequency Thermocoagulation vs Pulsed Radiofrequency Neuromodulation of Ganglion Impar in Chronic Perineal Pain of Nononcological Origin.

Science.gov (United States)

Usmani, Hammad; Dureja, G P; Andleeb, Roshan; Tauheed, Nazia; Asif, Naiyer

2018-01-10

Chronic nononcological perineal pain has been effectively managed by ganglion Impar block. Chemical neurolysis, cryoablation, and radiofrequency ablation have been the accepted methods of blockade. Recently, pulsed radiofrequency, a novel variant of conventional radiofrequency, has been used for this purpose. This was a prospective, randomized, double-blind study. Two different interventional pain management centers in India. To compare the efficacy of conventional radiofrequency and pulsed radiofrequency for gangliom Impar block. The patients were randomly allocated to one of two groups. In the conventional radiofrequency (CRF) group (N = 34), conventional radiofrequency ablation was done, and in the PRF pulsed radiofrequency (PRF) group (N = 31), pulsed radiofrequency ablation was done. After informed and written consent, fluoroscopy-guided ganglion Impar block was performed through the first intracoccygeal approach. The extent of pain relief was assessed by visual analog scale (VAS) at 24 hours, and at the first, third, and sixth weeks following the intervention. A questionnaire to evaluate subjective patient satisfaction was also used at each follow-up visit. In the CRF group, the mean VAS score decreased significantly from the baseline value at each follow-up visit. But in the PRF group, this decrease was insignificant except at 24-hour follow-up. Intergroup comparison also showed significantly better pain relief in the CRF group as compared with the PRF group. At the end of follow-up, 28 patients (82%) in the CRF group and four patients (13%) in the PRF group had excellent results, as assessed by the subjective patient satisfaction questionnaire. There was no complication in any patient of either study group, except for short-lived infection at the site of skin puncture in a few. Ganglion Impar block by conventional radiofrequency provided a significantly better quality of pain relief with no major side effects in patients with chronic

Radiofrequency exposure on fast patrol boats in the Royal Norwegian Navy--an approach to a dose assessment.

Science.gov (United States)

Baste, Valborg; Mild, Kjell Hansson; Moen, Bente E

2010-07-01

Epidemiological studies related to radiofrequency (RF) electromagnetic fields (EMF) have mainly used crude proxies for exposure, such as job titles, distance to, or use of different equipment emitting RF EMF. The Royal Norwegian Navy (RNoN) has measured RF field emitted from high-frequency antennas and radars on several spots where the crew would most likely be located aboard fast patrol boats (FPB). These boats are small, with short distance between the crew and the equipment emitting RF field. We have described the measured RF exposure aboard FPB and suggested different methods for calculations of total exposure and annual dose. Linear and spatial average in addition to percentage of ICNIRP and squared deviation of ICNIRP has been used. The methods will form the basis of a job exposure matrix where relative differences in exposure between groups of crew members can be used in further epidemiological studies of reproductive health. 2010 Wiley-Liss, Inc.

Radiofrequency ablation in dermatology

Directory of Open Access Journals (Sweden)

Sachdeva Silonie

2007-01-01

Full Text Available Radiofreqeuency ablation is a versatile dermatosurgical procedure used for surgical management of skin lesions by using various forms of alternating current at an ultra high frequency. The major modalities in radiofrequency are electrosection, electrocoagulation, electrodessication and fulguration. The use of radiofrequency ablation in dermatosurgical practice has gained importance in recent years as it can be used to treat most of the skin lesions with ease in less time with clean surgical field due to adequate hemostasis and with minimal side effects and complications. This article focuses on the major tissue effects and factors influencing radiofrequency ablation and its application for various dermatological conditions.

A Study of the interaction of radiation and semiconductor lasers: an analysis of transient and permanent effects induced on edge emitting and vertical cavity surface emitting laser diodes

International Nuclear Information System (INIS)

Pailharey, Eric

2000-01-01

The behavior of laser diodes under transient environment is presented in this work. The first section describes the basic phenomena of radiation interaction with matter. The radiative environments, the main characteristics of laser diodes and the research undertaken on the subject are presented and discussed. The tests on 1300 nm edge emitting laser diode are presented in the second section. The response to a transient ionizing excitation is explored using a 532 nm laser beam. The time of return to steady state after the perturbation is decomposed into several steps: decrease of the optical power during excitation, turn-on delay, relaxation oscillations and optical power offset. Their origins are analyzed using the device structure. To include all the phenomena in a numerical simulation of the device, an individual study of low conductivity materials used for the lateral confinement of the current density is undertaken. The effects of a single particle traversing the optical cavity and an analysis of permanent damages induced by neutrons are also determined. In the last section, 850 nm vertical cavity surface emitting laser diodes (VCSEL) are studied. The behavior of these devices which performances are in constant evolution, is investigated as a function of both temperature and polarization. Then VCSEL are submitted to transient ionizing irradiation and their responses are compared to those of edge emitting diodes. When proton implantation is used in the process, we observe the same behavior for both technologies. VCSEL were submitted to neutron fluence and we have studied the influence of the damages on threshold current, emission patterns and maximum of optical power. (author) [fr

Effects of Mobile Phones on Children's and Adolescents' Health: A Commentary

Science.gov (United States)

Hardell, Lennart

2018-01-01

The use of digital technology has grown rapidly during the last couple of decades. During use, mobile phones and cordless phones emit radiofrequency (RF) radiation. No previous generation has been exposed during childhood and adolescence to this kind of radiation. The brain is the main target organ for RF emissions from the handheld wireless…

Estimation of soft X-ray and EUV transition radiation power emitted from the MIRRORCLE-type tabletop synchrotron.

Science.gov (United States)

Toyosugi, N; Yamada, H; Minkov, D; Morita, M; Yamaguchi, T; Imai, S

2007-03-01

The tabletop synchrotron light sources MIRRORCLE-6X and MIRRORCLE-20SX, operating at electron energies E(el) = 6 MeV and E(el) = 20 MeV, respectively, can emit powerful transition radiation (TR) in the extreme ultraviolet (EUV) and the soft X-ray regions. To clarify the applicability of these soft X-ray and EUV sources, the total TR power has been determined. A TR experiment was performed using a 385 nm-thick Al foil target in MIRRORCLE-6X. The angular distribution of the emitted power was measured using a detector assembly based on an NE102 scintillator, an optical bundle and a photomultiplier. The maximal measured total TR power for MIRRORCLE-6X is P(max) approximately equal 2.95 mW at full power operation. Introduction of an analytical expression for the lifetime of the electron beam allows calculation of the emitted TR power by a tabletop synchrotron light source. Using the above measurement result, and the theoretically determined ratio between the TR power for MIRRORCLE-6X and MIRRORCLE-20SX, the total TR power for MIRRORCLE-20SX can be obtained. The one-foil TR target thickness is optimized for the 20 MeV electron energy. P(max) approximately equal 810 mW for MIRRORCLE-20SX is obtained with a single foil of 240 nm-thick Be target. The emitted bremsstrahlung is negligible with respect to the emitted TR for optimized TR targets. From a theoretically known TR spectrum it is concluded that MIRRORCLE-20SX can emit 150 mW of photons with E > 500 eV, which makes it applicable as a source for performing X-ray lithography. The average wavelength, \\overline\\lambda = 13.6 nm, of the TR emission of MIRRORCLE-20SX, with a 200 nm Al target, could provide of the order of 1 W EUV.

CT-guided radiofrequency tumor ablation in children

International Nuclear Information System (INIS)

Botsa, Evanthia; Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas; Koutsogiannis, Ioannis; Ziakas, Panayiotis D.; Alexopoulou, Efthimia

2014-01-01

Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

CT-guided radiofrequency tumor ablation in children

Energy Technology Data Exchange (ETDEWEB)

Botsa, Evanthia [National and Kapodistrian University of Athens, First Pediatric Clinic, Agia Sofia Children' s Hospital, Athens (Greece); Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas [Sotiria General Hospital for Chest Diseases, Department of Medical Imaging and Interventional Radiology, Athens (Greece); Koutsogiannis, Ioannis [General Military Hospital NIMTS, Department of Medical Imaging, Athens (Greece); Ziakas, Panayiotis D. [Warren Alpert Medical School of Brown University Rhode Island Hospital, Division of Infectious Diseases, Providence, RI (United States); Alexopoulou, Efthimia [Attikon University Hospital, Second Department of Radiology, Athens University School of Medicine, Athens (Greece)

2014-11-15

Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

Radiofrequency electromagnetic fields in the Cookridge area of Leeds

CERN Document Server

Fuller, K; Judd, P M; Lowe, A J; Shaw, J

2002-01-01

On the 8 and 9 May 2002 representatives of the National Radiological Protection Board (NRPB) performed a radiofrequency electromagnetic field survey in the Cookridge area of Leeds in order to assess exposure to radio signals from transmitters mounted on a water tower/a lattice tower and a radio station tower. Guidelines on limiting exposure to radio signals have been published by NRPB and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are designed to prevent established adverse effects on human health. During this survey, the total exposures due to all radio signals from 30 MHz to 18000 MHz (18 GHz) were measured. This frequency range was chosen as it includes mobile phone base station transmissions, which are at around 900 and 1800 MHz and super high frequency (SHF) transmissions from most of the large microwave dish antennas mounted on the towers. In addition, other major sources of radiofrequency electromagnetic fields in the environment such as broadcast radio...

RADIOFREQUENCY SUPERCONDUCTIVITY: Workshop

International Nuclear Information System (INIS)

Lengeler, Herbert

1989-01-01

Superconducting radiofrequency is already playing an important role in the beam acceleration system for the TRISTAN electron-positron collider at the Japanese KEK Laboratory and new such systems are being prepared for other major machines. Thus the fourth Workshop on Radiofrequency Superconductivity, organized by KEK under the chairmanship of local specialist Yuzo Kojima and held just before the International Conference on High Energy Accelerators, had much progress to review and even more to look forward to

Anthropogenic radiofrequency electromagnetic fields as an emerging threat to wildlife orientation

International Nuclear Information System (INIS)

Balmori, Alfonso

2015-01-01

The rate of scientific activity regarding the effects of anthropogenic electromagnetic radiation in the radiofrequency (RF) range on animals and plants has been small despite the fact that this topic is relevant to the fields of experimental biology, ecology and conservation due to its remarkable expansion over the past 20 years. Current evidence indicates that exposure at levels that are found in the environment (in urban areas and near base stations) may particularly alter the receptor organs to orient in the magnetic field of the earth. These results could have important implications for migratory birds and insects, especially in urban areas, but could also apply to birds and insects in natural and protected areas where there are powerful base station emitters of radiofrequencies. Therefore, more research on the effects of electromagnetic radiation in nature is needed to investigate this emerging threat. - Highlights: • The growth of wireless telecommunication technologies causes increased electrosmog. • Radio frequency fields in the MHz range disrupt insect and bird orientation. • Radio frequency noise interferes with the primary process of magnetoreception. • Existing guidelines do not adequately protect wildlife. • Further research in this area is urgent

Anthropogenic radiofrequency electromagnetic fields as an emerging threat to wildlife orientation

Energy Technology Data Exchange (ETDEWEB)

Balmori, Alfonso, E-mail: balmaral@jcyl.es

2015-06-15

The rate of scientific activity regarding the effects of anthropogenic electromagnetic radiation in the radiofrequency (RF) range on animals and plants has been small despite the fact that this topic is relevant to the fields of experimental biology, ecology and conservation due to its remarkable expansion over the past 20 years. Current evidence indicates that exposure at levels that are found in the environment (in urban areas and near base stations) may particularly alter the receptor organs to orient in the magnetic field of the earth. These results could have important implications for migratory birds and insects, especially in urban areas, but could also apply to birds and insects in natural and protected areas where there are powerful base station emitters of radiofrequencies. Therefore, more research on the effects of electromagnetic radiation in nature is needed to investigate this emerging threat. - Highlights: • The growth of wireless telecommunication technologies causes increased electrosmog. • Radio frequency fields in the MHz range disrupt insect and bird orientation. • Radio frequency noise interferes with the primary process of magnetoreception. • Existing guidelines do not adequately protect wildlife. • Further research in this area is urgent.

High performance multilayered nano-crystalline silicon/silicon-oxide light-emitting diodes on glass substrates

Energy Technology Data Exchange (ETDEWEB)

Darbari, S; Shahmohammadi, M; Mortazavi, M; Mohajerzadeh, S [Thin Film and Nano-Electronic Laboratory, School of ECE, University of Tehran, Tehran (Iran, Islamic Republic of); Abdi, Y [Nano-Physics Research Laboratory, Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of); Robertson, M; Morrison, T, E-mail: mohajer@ut.ac.ir [Department of Physics, Acadia University, Wolfville, NS (Canada)

2011-09-16

A low-temperature hydrogenation-assisted sequential deposition and crystallization technique is reported for the preparation of nano-scale silicon quantum dots suitable for light-emitting applications. Radio-frequency plasma-enhanced deposition was used to realize multiple layers of nano-crystalline silicon while reactive ion etching was employed to create nano-scale features. The physical characteristics of the films prepared using different plasma conditions were investigated using scanning electron microscopy, transmission electron microscopy, room temperature photoluminescence and infrared spectroscopy. The formation of multilayered structures improved the photon-emission properties as observed by photoluminescence and a thin layer of silicon oxy-nitride was then used for electrical isolation between adjacent silicon layers. The preparation of light-emitting diodes directly on glass substrates has been demonstrated and the electroluminescence spectrum has been measured.

Resonance effects of transition radiation emitted from thin foil stacks using electron beam

Energy Technology Data Exchange (ETDEWEB)

Awata, Takaaki; Yajima, Kazuaki; Tanaka, Takashi [Kyoto Univ. (Japan). Faculty of Engineering; and others

1997-03-01

Transition Radiation(TR) X rays are expected to be a high brilliant X-ray source because the interference among TR X rays emitted from many thin foils placed periodically in vacuum can increase their intensity and make them quasi-monochromatic. In order to study the interference (resonance) effects of TR, we measured the energy spectra of TR for several sets of thin-foil stacks at various emission angles. It was found that the resonance effects of TR are classified into intrafoil and interfoil resonances and the intensity of TR X rays increases nonlinearly with increasing foil number, attributing to the interfoil resonance. It became evident that the brilliance of TR is as high as that of SR. (author)

21 CFR 882.4400 - Radiofrequency lesion generator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion generator. 882.4400 Section... (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4400 Radiofrequency lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting

Energy Technology Data Exchange (ETDEWEB)

Matsui, Yusuke, E-mail: wckyh140@yahoo.co.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp; Iguchi, Toshihiro, E-mail: i10476@yahoo.co.jp; Fujiwara, Hiroyasu, E-mail: hirofujiwar@gmail.com; Kawabata, Takahiro, E-mail: tkhr-kwbt@yahoo.co.jp [Okayama University Medical School, Department of Radiology (Japan); Yamauchi, Takatsugu, E-mail: me9248@hp.okayama-u.ac.jp; Yamaguchi, Takuya, E-mail: me8738@hp.okayama-u.ac.jp [Okayama University Hospital, Central Division of Radiology (Japan); Kanazawa, Susumu, E-mail: susumu@cc.okayama-u.ac.jp [Okayama University Medical School, Department of Radiology (Japan)

2016-06-15

IntroductionComputed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking.Materials and MethodsRadiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator’s finger skin was measured using thermoluminescent dosimeter rings.ResultsThe mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator’s finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA.ConclusionRadiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting.

Science.gov (United States)

Matsui, Yusuke; Hiraki, Takao; Gobara, Hideo; Iguchi, Toshihiro; Fujiwara, Hiroyasu; Kawabata, Takahiro; Yamauchi, Takatsugu; Yamaguchi, Takuya; Kanazawa, Susumu

2016-06-01

Computed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking. Radiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator's finger skin was measured using thermoluminescent dosimeter rings. The mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator's finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA. Radiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

Biological effects of exposure to non-ionising electromagnetic fields and radiation: III radiofrequency and microwave radiation

International Nuclear Information System (INIS)

Saunders, R.D.; Kowalczuk, C.I.; Sienkiewicz, Z.J.

1991-12-01

The biological effects of experimental exposure to radiofrequency (RF) and microwave radiation above 100 kHz are reviewed with the intention of providing a summary of effects directly relevant to considerations of the health and safety of exposed people. The biological bases for restricting exposures are also briefly discussed. Studies of the possible effects of electromagnetic field exposure on human populations are described in a separate report. The majority of the biological effects of acute exposure to radiofrequency (RF) and microwave radiation are consistent with responses to induced heating, resulting either from frank rises in tissue or body temperature of about 1 0 C or more, or from responses involved in minimising the total heat load. Most responses have been reported at specific energy absorption rates (SARs) above about 1-2 W kg -1 in different animal species exposed under various environmental conditions. These animal, particularly primate, data indicate the sorts of responses that are likely to occur in humans subject to a sufficient heat load. In addition, most animal and cell culture data indicate that RF and microwave exposure is not mutagenic and so will not result in somatic mutation or in hereditary effects; such exposure is therefore unlikely to initiate cancers. With some exceptions that are described below, restrictions on the acute exposure of humans to RF or microwave radiation should be based on the acute responses to raised body temperature. It seems probable that healthy people can tolerate short-term (minute-hour) rises in body temperature of up to about 1 0 C. This rise is well below the maximum tolerable increase but nevertheless represents a significant thermal load. The evidence suggests that the exposure of resting humans in moderate environments at whole-body SARs of 1 W kg -1 , and up to 4 W kg -1 for short periods, will result in body temperature rises of less than 1 0 C. A restriction of whole-body SAR for healthy people to 0

Radiofrequency Energy and Electrode Proximity Influences Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation Lesion Size: An In Vitro Study with Clinical Correlation.

Science.gov (United States)

Staudt, Michael D; Maturu, Sarita; Miller, Jonathan P

2018-02-16

Radiofrequency thermocoagulation of epileptogenic foci via stereoelectroencephalography (SEEG) electrodes has been suggested as a treatment for medically intractable epilepsy, but reported outcomes have been suboptimal, possibly because lesions generated using conventional high-energy radiofrequency parameters are relatively small. To describe a technique of delivering low energy across separate SEEG electrodes in order to create large confluent radiofrequency lesions. The size and configuration of radiofrequency lesions using different radiofrequency intensity and interelectrode distance was assessed in egg whites. Magnetic resonance images (MRI) from 3 patients who had undergone radiofrequency lesion creation were evaluated to determine the contribution of lesion intensity and electrode separation on lesion size. Electroencephalography, MRI, and clinical data were assessed before and after lesion creation. Both in Vitro and in Vivo analysis revealed that less energy paradoxically produced larger lesions, with the largest possible lesions produced when radiofrequency power was applied for long duration at less than 3 W. Linear separation of electrodes also contributed to lesion size, with largest lesions produced when electrodes were separated by a linear distance of between 5 and 12 mm. Clinical lesions produced using these parameters were large and resulted in improvement in interictal and ictal activity. Radiofrequency lesions produced using low-energy delivery between SEEG electrodes in close proximity can produce a large lesion. These findings might have advantages for treatment of focal epilepsy.

Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

Science.gov (United States)

Cartier, Victoire; Boursier, Jérôme; Lebigot, Jérôme; Oberti, Frédéric; Fouchard-Hubert, Isabelle; Aubé, Christophe

2016-03-01

Thermo-ablation by radiofrequency is recognized as a curative treatment for early-stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure. A total of 171 consecutive patients with 214 hepatocellular carcinomas were retrospectively included. One hundred fifty-eight tumors were treated with an expandable monopolar electrode and 56 with a multipolar technique using several linear bipolar electrodes. Imaging studies at 6 weeks after treatment, then every 3 months, assessed local effectiveness. Radiofrequency failure was defined as persistent residual tumor after two sessions (primary radiofrequency failure) or local tumor recurrence during follow-up. This study received institutional review board approval (number 2014/77). Imaging showed complete tumor ablation in 207 of 214 lesions after the first session of radiofrequency. After a second session, only two cases of residual viable tumor were observed. During follow-up, there were 46 local tumor recurrences. Thus, radiofrequency failure occurred in 48/214 (22.4%) cases. By multivariate analysis, technique (P radiofrequency failure. Failure rate was lower with the multipolar technique for tumors radiofrequency, multipolar radiofrequency improves tumor ablation with a subsequent lower rate of local tumor recurrence. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Most cancer in firefighters is due to radio-frequency radiation exposure not inhaled carcinogens.

Science.gov (United States)

Milham, S

2009-11-01

Recent reviews and reports of cancer incidence and mortality in firefighters conclude that they are at an increased risk of a number of cancers. These include leukemia, multiple myeloma, non-Hodgkin's lymphoma, male breast cancer, malignant melanoma, and cancers of the brain, stomach, colon, rectum, prostate, urinary bladder, testes, and thyroid. Firefighters are exposed to a long list of recognized or probable carcinogens in combustion products and the presumed route of exposure to these carcinogens is by inhalation. Curiously, respiratory system cancers and diseases are usually not increased in firefighters as they are in workers exposed to known inhaled carcinogens. The list of cancers with increased risk in firefighters strongly overlaps the list of cancers at increased risk in workers exposed to electromagnetic fields (EMF) and radiofrequency radiation (RFR). Firefighters have increased exposure to RFR in the course of their work, from the mobile two-way radio communications devices which they routinely use while fighting fires, and at times from firehouse and fire vehicle radio transmitters. I suggest that some of the increased cancer risk in firefighters is caused by RFR exposure, and is therefore preventable. The precautionary principle should be applied to reduce the risk of cancer in firefighters, and workman's compensation rules will necessarily need to be modified.

Synchrotron radiation

International Nuclear Information System (INIS)

Farge, Y.

1982-01-01

Synchrotron radiation is produced by electrons accelerated near the velocity of light in storage rings, which are used for high energy Physics experiments. The radiation light exhibits a wide spread continuous spectrum ranging from 01 nanometre to radiofrequency. This radiation is characterized by high power (several kilowatts) and intense brightness. The paper recalls the emission laws and the distinctive properties of the radiation, and gives some of the numerous applications in research, such as molecular spectroscopy, X ray diffraction by heavy proteins and X ray microlithography in LVSI circuit making [fr

Pulse-dose radiofrequency treatment in pain management-initial experience.

Science.gov (United States)

Ojango, Christine; Raguso, Mario; Fiori, Roberto; Masala, Salvatore

2018-05-01

Radiofrequency procedures have been used for treating various chronic pain conditions for decades. These minimally invasive percutaneous treatments employ an alternating electrical current with oscillating radiofrequency wavelengths to eliminate or alter pain signals from the targeted site. The aim of the continuous radiofrequency procedure is to increase the temperature sufficiently to create an irreversible thermal lesion on nerve fibres and thus permanently interrupt pain signals. The pulsed radiofrequency procedure utilises short pulses of radiofrequency current with intervals of longer pauses to avert a temperature increase to the level of permanent tissue damage. The goal of these pulses is to alter the processing of pain signals, but to avoid relevant structural damage to nerve fibres, as seen in the continuous radiofrequency procedure. The pulse-dose radiofrequency procedure is a technical improvement of the pulsed radiofrequency technique in which the delivery mode of the current is adapted. During the pulse-dose radiofrequency procedure thermal damage is avoided. In addition, the amplitude and width of the consecutive pulses are kept the same. The method ensures that each delivered pulse keeps the same characteristics and therefore the dose is similar between patients. The current review outlines the pulse-dose radiofrequency procedure and presents our institution's chronic pain management studies.

Discrete curved ray-tracing method for radiative transfer in an absorbing-emitting semitransparent slab with variable spatial refractive index

International Nuclear Information System (INIS)

Liu, L.H.

2004-01-01

A discrete curved ray-tracing method is developed to analyze the radiative transfer in one-dimensional absorbing-emitting semitransparent slab with variable spatial refractive index. The curved ray trajectory is locally treated as straight line and the complicated and time-consuming computation of ray trajectory is cut down. A problem of radiative equilibrium with linear variable spatial refractive index is taken as an example to examine the accuracy of the proposed method. The temperature distributions are determined by the proposed method and compared with the data in references, which are obtained by other different methods. The results show that the discrete curved ray-tracing method has a good accuracy in solving the radiative transfer in one-dimensional semitransparent slab with variable spatial refractive index

Effect of Exposure to Non-ionizing Radiation (Electromagnetic Fields on Human System: A Literature Review

Directory of Open Access Journals (Sweden)

Paula Rubya Souza C and acirc;mara

2014-08-01

Full Text Available The indiscriminate presence of radio base stations, which emit non-ionizing radiation (NIR, as well as the frequent use of mobile phones, can cause increased susceptibility of populations to the emergence of diseases such as cancers of the head and neck, biochemical, hematopoietic and hepatic changes, among others. Exposure to physical contamination, including NIR, has been implicated in numerous diseases, raising concerns about the widespread sources of exposure to this type of radiation. This paper reviews studies that have assessed associations between likely exposure to electromagnetic fields, such as radiofrequency transmissions, and many kinds of human diseases including cancer, as well as alerts to the current knowledge on the association between environmental exposure to NIR and the risk of development of adverse human health effects. This way, there appears to be an urgent need to reconsider exposure limits for low frequency and static magnetic fields, based on combined experimental and epidemiological research. [J Interdiscipl Histopathol 2014; 2(4.000: 187-190

A survey on monopolar radiofrequency treatment.

Science.gov (United States)

Suh, Dong Hye; Hong, Eun Sun; Kim, Hyun Joo; Lee, Sang Jun; Kim, Hei Sung

2017-09-01

This questionnaire-based study was aimed to measure the level of appreciation, awareness of the special tips, and practice patterns of monopolar radiofrequency among Korean dermatologists practicing a specific monopolar radiofrequency device (Thermage® Inc., Hayward, CA). A total of 82 surveys were analyzed to show that the majority of participants (78.8%) were highly satisfied with the outcomes of monopolar radiofrequency treatment. All respondents were aware of the Eye Tip 0.25 cm 2 , and the majority knew the difference between the Face tip (blue) and the Total tip (orange). Most (86.3%) agreed to the statement that 900 shots were appropriate for facial tightening in those between the ages of 35 and 65 years. 66.2% of participants reported to have perform monopolar radiofrequency to extra-facial sites within the past year. As for the tips, the Total tip was most popular for all body sties and the Big tip was favored for the abdomen, thighs and buttock. We hope our data allow dermatologists to better utilize monopolar radiofrequency. © 2017 Wiley Periodicals, Inc.

Mobile phone base station-emitted radiation does not induce phosphorylation of Hsp27.

Science.gov (United States)

Hirose, H; Sakuma, N; Kaji, N; Nakayama, K; Inoue, K; Sekijima, M; Nojima, T; Miyakoshi, J

2007-02-01

An in vitro study focusing on the effects of low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields act to induce phosphorylation and overexpression of heat shock protein hsp27. First, we evaluated the responses of human cells to microwave exposure at a specific absorption rate (SAR) of 80 mW/kg, which corresponds to the limit of the average whole-body SAR for general public exposure defined as a basic restriction in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Second, we investigated whether continuous wave (CW) and Wideband Code Division Multiple Access (W-CDMA) modulated signal RF fields at 2.1425 GHz induced activation or gene expression of hsp27 and other heat shock proteins (hsps). Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80 and 800 mW/kg for 2-48 h, and CW radiation at 80 mW/kg for 24 h. Human IMR-90 fibroblasts from fetal lungs were exposed to W-CDMA at 80 and 800 mW/kg for 2 or 28 h, and CW at 80 mW/kg for 28 h. Under the RF field exposure conditions described above, no significant differences in the expression levels of phosphorylated hsp27 at serine 82 (hsp27[pS82]) were observed between the test groups exposed to W-CDMA or CW signal and the sham-exposed negative controls, as evaluated immediately after the exposure periods by bead-based multiplex assays. Moreover, no noticeable differences in the gene expression of hsps were observed between the test groups and the negative controls by DNA Chip analysis. Our results confirm that exposure to low-level RF field up to 800 mW/kg does not induce phosphorylation of hsp27 or expression of hsp gene family.

Statistical analysis of electromagnetic radiation measurements in the vicinity of indoor microcell GSM/UMTS base stations in Serbia.

Science.gov (United States)

Koprivica, Mladen; Petrić, Majda; Nešković, Nataša; Nešković, Aleksandar

2016-01-01

To determine the level of radiofrequency radiation generated by base stations of Global System for Mobile Communications and Universal Mobile Telecommunication System, extensive electromagnetic field strength measurements were carried out in the vicinity of 664 base station locations. These were classified into three categories: indoor, masts, and locations with installations on buildings. Although microcell base stations with antennas installed indoors typically emit less power than outdoor macrocell base stations, the fact that people can be found close to antennas requires exposure originating from these base stations to be carefully considered. Measurement results showed that maximum recorded value of electric field strength exceeded International Commission on Non-Ionizing Radiation Protection reference levels at 7% of indoor base station locations. At the same time, this percentage was much lower in the case of masts and installations on buildings (0% and 2.5%, respectively). © 2015 Wiley Periodicals, Inc.

Exposure to non-ionizing electromagnetic fields emitted from mobile phones induced DNA damage in human ear canal hair follicle cells.

Science.gov (United States)

Akdag, Mehmet; Dasdag, Suleyman; Canturk, Fazile; Akdag, Mehmet Zulkuf

2018-01-01

The aim of this study was to investigate effect of radiofrequency radiation (RFR) emitted from mobile phones on DNA damage in follicle cells of hair in the ear canal. The study was carried out on 56 men (age range: 30-60 years old)in four treatment groups with n = 14 in each group. The groups were defined as follows: people who did not use a mobile phone (Control), people use mobile phones for 0-30 min/day (second group), people use mobile phones for 30-60 min/day (third group) and people use mobile phones for more than 60 min/day (fourth group). Ear canal hair follicle cells taken from the subjects were analyzed by the Comet Assay to determine DNA damages. The Comet Assay parameters measured were head length, tail length, comet length, percentage of head DNA, tail DNA percentage, tail moment, and Olive tail moment. Results of the study showed that DNA damage indicators were higher in the RFR exposure groups than in the control subjects. In addition, DNA damage increased with the daily duration of exposure. In conclusion, RFR emitted from mobile phones has a potential to produce DNA damage in follicle cells of hair in the ear canal. Therefore, mobile phone users have to pay more attention when using wireless phones.

21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency electrosurgical cautery apparatus... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency electrosurgical cautery apparatus. (a) Identification. A radiofrequency electrosurgical cautery apparatus is an AC...

Miniature scanning electron microscope for investigation of the interior surface of a superconducting Nb radiofrequency accelerating cavity

International Nuclear Information System (INIS)

Mathewson, A.G.; Grillot, A.

1982-01-01

A miniature scanning electron microscope with an electron beam diameter approx.1 μm has been constructed for high resolution examination at room temperature of the interior surface of a superconducting Nb radiofrequency accelerating cavity. Various objects and surface structures were observed, some of which could be correlated with lossy regions or ''hot spots'' detected previously on the outside surface during cavity operation at < or =4.2 K by a chain of carbon resistors. No internal surface features were observed which could conclusively be correlated with field emitting electron sources

Project 8: Update on a radiofrequency tritium spectrometer

Energy Technology Data Exchange (ETDEWEB)

Monreal, B. [University of California, Santa Barbara (United States)

2012-09-28

We describe a novel technique for measuring the energies of beta decay electrons. The technique relies on the detection of coherent radiation emitted by an electron in a cyclotron orbit in a strong magnetic field. Since the frequency of cyclotron orbit depends on the particle Lorentz boost, the detection and measurement of the coherent radiation emitted is tantamount to measuring the kinetic energy of the electron. As the technique inherently involves a nondestructive frequency measurement, it can in principle achieve a high resolution and accuracy. A new experimental effort, known as Project 8, will apply this technique to a sensitive measurement of the beta endpoint of tritium, which is sensitive to the absolute mass scale of the neutrino. In this paper we describe experimental progress towards demonstrating the Project 8 technique, and present the configuration of a pilot experiment.

Temperature-controlled irrigated tip radiofrequency catheter ablation

DEFF Research Database (Denmark)

Petersen, H H; Chen, X; Pietersen, Adrian

1998-01-01

INTRODUCTION: In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion......: We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip....

Radiofrequency Ablation of Hepatic Cysts : Case Report

International Nuclear Information System (INIS)

Lee, Ye Ri; Kim, Pyo Nyun

2005-01-01

Radiofrequency ablation has been frequently performed on intra-hepatic solid tumor, namely, hepatocellular carcinoma, metastatic tumor and cholangio carcinoma, for take the cure. But, the reports of radiofrequency ablation for intrahepatic simple cysts are few. In vitro experiment of animal and in vivo treatment for intrahepatic cysts of human had been reported in rare cases. We report 4 cases of radiofrequency ablation for symptomatic intrahepatic cysts

Hybrid Light-Emitting Diode Enhanced With Emissive Nanocrystals

DEFF Research Database (Denmark)

Kopylov, Oleksii

This thesis investigates a new type of white light emitting hybrid diode, composed of a light emitting GaN/InGaN LED and a layer of semiconductor nanocrystals for color conversion. Unlike standard white LEDs, the device is configured to achieve high color conversion efficiency via non-radiative e......This thesis investigates a new type of white light emitting hybrid diode, composed of a light emitting GaN/InGaN LED and a layer of semiconductor nanocrystals for color conversion. Unlike standard white LEDs, the device is configured to achieve high color conversion efficiency via non...... of the hybrid diode fabrication including process techniques for GaN LED and incorporation of the nanocrystals are presented with the emphasis on the differences with standard LED processing. Results and analysis of optical and electrical characterization including photoluminescence (PL), micro-PL, time......-resolved PL and electroluminescence (EL) together with current-voltage characteristics are presented to evaluate the device performance. A clear evidence of non-radiative energy transfer was seen in the carrier dynamics of both the LED and the nanocrystals when the quantum well – nanocrystals separation...

Ablation of liver metastases by radiofrequency

International Nuclear Information System (INIS)

Baere, T. de

2012-01-01

Radiofrequency is a thermal ablative technique that is most often used percuteanously under image guidance. Thermal damage is obtained through frictional heating of a high frequency current. The maximal volume of destruction obtained in one radiofrequency delivery is around 4 cm and consequently, best indication for treatment are tumours below 3 cm. When compared, radiofrequency and surgical removal for tumours below 25 mm in diameter demonstrated a rate of incomplete resection/ablation of 6% and 7.3% respectively. Median survival after the first radiofrequency of a liver metastasis of CRC is reported to be 24 to 52 months with a 5 years overall survival of 18 to 44%. The median overall survival increases from 22 to 48 months depending on the use of radiofrequency ablation as rescue treatment after failure of others, or as a first line treatment. For patients with a single tumour, less than 4 cm, the survival rates at 1, 3, and 5 years are respectively 97%, 84% and 40%, with a median survival of 50 months. Follow-up imaging requires to use contrast-enhanced CT or MRI, looking for local recurrences evidenced by local foci of enhancement at the periphery of the ablation zone. (author)

Electromagnetic noise inhibits radiofrequency radiation-induced DNA damage and reactive oxygen species increase in human lens epithelial cells

Science.gov (United States)

Wu, Wei; Wang, KaiJun; Ni, Shuang; Ye, PanPan; Yu, YiBo; Ye, Juan; Sun, LiXia

2008-01-01

Purpose The goal of this study was to investigate whether superposing of electromagnetic noise could block or attenuate DNA damage and intracellular reactive oxygen species (ROS) increase of cultured human lens epithelial cells (HLECs) induced by acute exposure to 1.8 GHz radiofrequency field (RF) of the Global System for Mobile Communications (GSM). Methods An sXc-1800 RF exposure system was used to produce a GSM signal at 1.8 GHz (217 Hz amplitude-modulated) with the specific absorption rate (SAR) of 1, 2, 3, and 4 W/kg. After 2 h of intermittent exposure, the ROS level was assessed by the fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). DNA damage to HLECs was examined by alkaline comet assay and the phosphorylated form of histone variant H2AX (γH2AX) foci formation assay. Results After exposure to 1.8 GHz RF for 2 h, HLECs exhibited significant intracellular ROS increase in the 2, 3, and 4 W/kg groups. RF radiation at the SAR of 3 W/kg and 4 W/kg could induce significant DNA damage, examined by alkaline comet assay, which was used to detect mainly single strand breaks (SSBs), while no statistical difference in double strand breaks (DSBs), evaluated by γH2AX foci, was found between RF exposure (SAR: 3 and 4 W/kg) and sham exposure groups. When RF was superposed with 2 μT electromagnetic noise could block RF-induced ROS increase and DNA damage. Conclusions DNA damage induced by 1.8 GHz radiofrequency field for 2 h, which was mainly SSBs, may be associated with the increased ROS production. Electromagnetic noise could block RF-induced ROS formation and DNA damage. PMID:18509546

Influence of radiation-dose pattern from inhaled beta--gamma-emitting radionuclides on canine peripheral lymphocytes

International Nuclear Information System (INIS)

Jones, R.K.; Boecker, B.B.; Pickrell, J.A.; Hobbs, C.H.; McClellan, R.O.

1976-01-01

As part of studies assess the biological hazards associated with inhaled radionuclides, periodic hematologic evaluations were performed on beagle dogs given a single nose-only exposure to aerosols of beta--gamma-emitting isotopes. The physical form and specific radionuclides selected produced radiation-dose patterns representative of those which might be encountered in the event of human accidental exposures. Dogs received graded lung burdens of either 90 Y, 91 Y, 144 Ce, or 90 Sr, each in fused clay. Differences in the effective half-lives of these radionuclides resulted in a spectrum of cumulative radiation doses to lung delivered at a variety of dose rates. Since the form in which the radionuclides were inhaled was relatively insoluble, the lung and intrathoracic tissues represented the primary recipient of the dose. Regardless of the effective half-life of radionuclide retention, a dose-related depression of peripheral lymphocytes was observed at various times after inhalation exposure. The time at which maximum depression and subsequent recovery occurred, however, was most directly related to the effective half-life of the radionuclide. Of special interest was the persistence of lymphopenia through 2 1 / 2 years after exposure to 144 Ce and 90 Sr in fused clay where, other than tracheobronchial lymph nodes, the lymphoid tissue received very little radiation dose. The possible mechanisms responsible for lymphocyte depression from these various radiation-dose patterns are discussed

Radiofrequency and health. Expertise update. Opinion of the ANSES. Collective expertise report

International Nuclear Information System (INIS)

Cardis, Elisabeth; Dore, Jean-Francois; Marc-Vergnes, Jean-Pierre; Agnani, Jean-Benoit; Bruguiere, Pierre; Crouzier, David; Debaz, Josquin; Debuire, Brigitte; Deltour, Isabelle; LE Drean, Yves; Ledoigt, Gerard; Letertre, Thierry; Marchand, Dorothee; Massardier-Pilonchery, Amelie; Nadi, Mustapha; Pereira De Vasconcelos, Anne; Hours, Martine; Fite, Johanna; Merckel, Olivier; Roth, Olivia; Vergriette, Benoit; Saddoki, Sophia

2013-10-01

In a context of development of new technologies of wireless communications, and therefore of radio-electric signals used to transmit information, this voluminous document reports a detailed study on the effects of radiofrequency on health. It is notably based on a large literature survey and on an assessment of the level of proof of these effects by experts (proved, possible, probable, insufficiently proved, or no effect on mankind). These effects can be either biological or on health. The report presents the context, scope and modalities of the expertise study, presents the main artificial and natural sources of radiofrequency radiation, gives a detailed presentation of new exposure sources (new signals, new radio-electric networks and their applications like mobile phones, pads, mobile television, local wireless networks, RFID, so on). It describes metrology and dose measurement techniques for electromagnetic fields (exposure characterization in laboratory, characterization of the electromagnetic environment, individual exposure measurement devices, digital dosimetry). It addresses the efficiency of anti-wave devices. The next part presents the literature survey (method, analysis, results). The authors then report an assessment of the risk level related to radio-frequencies for the central nervous system (neurotoxicity mechanisms, cognitive functions, memory and behaviour, sleep and circadian rhythms, hearing functions, neurological and neuro-degenerative diseases), and an assessment of the risk level of radio-frequencies for other non-carcinogenic effects (possible mechanisms, reproduction, immunology, endocrine system, and so on). They discuss the researches on potential carcinogenic mechanisms. They give an overview of the evolutions of regulations and management measures in France, and propose a set of recommendations

Enhancement of chemically induced reactive oxygen species production and DNA damage in human SH-SY5Y neuroblastoma cells by 872 MHz radiofrequency radiation

Energy Technology Data Exchange (ETDEWEB)

Luukkonen, Jukka [Department of Environmental Science, University of Kuopio, Bioteknia 2, P.O. Box 1627, FI-70211 Kuopio (Finland)], E-mail: Jukka.Luukkonen@uku.fi; Hakulinen, Pasi; Maeki-Paakkanen, Jorma [Department of Environmental Health, National Public Health Institute, P.O. Box 95, FI-70701 Kuopio (Finland); Juutilainen, Jukka; Naarala, Jonne [Department of Environmental Science, University of Kuopio, Bioteknia 2, P.O. Box 1627, FI-70211 Kuopio (Finland)

2009-03-09

The objective of the study was to investigate effects of 872 MHz radiofrequency (RF) radiation on intracellular reactive oxygen species (ROS) production and DNA damage at a relatively high SAR value (5 W/kg). The experiments also involved combined exposure to RF radiation and menadione, a chemical inducing intracellular ROS production and DNA damage. The production of ROS was measured using the fluorescent probe dichlorofluorescein and DNA damage was evaluated by the Comet assay. Human SH-SY5Y neuroblastoma cells were exposed to RF radiation for 1 h with or without menadione. Control cultures were sham exposed. Both continuous waves (CW) and a pulsed signal similar to that used in global system for mobile communications (GSM) mobile phones were used. Exposure to the CW RF radiation increased DNA breakage (p < 0.01) in comparison to the cells exposed only to menadione. Comparison of the same groups also showed that ROS level was higher in cells exposed to CW RF radiation at 30 and 60 min after the end of exposure (p < 0.05 and p < 0.01, respectively). No effects of the GSM signal were seen on either ROS production or DNA damage. The results of the present study suggest that 872 MHz CW RF radiation at 5 W/kg might enhance chemically induced ROS production and thus cause secondary DNA damage. However, there is no known mechanism that would explain such effects from CW RF radiation but not from GSM modulated RF radiation at identical SAR.

Enhancement of chemically induced reactive oxygen species production and DNA damage in human SH-SY5Y neuroblastoma cells by 872 MHz radiofrequency radiation

International Nuclear Information System (INIS)

Luukkonen, Jukka; Hakulinen, Pasi; Maeki-Paakkanen, Jorma; Juutilainen, Jukka; Naarala, Jonne

2009-01-01

The objective of the study was to investigate effects of 872 MHz radiofrequency (RF) radiation on intracellular reactive oxygen species (ROS) production and DNA damage at a relatively high SAR value (5 W/kg). The experiments also involved combined exposure to RF radiation and menadione, a chemical inducing intracellular ROS production and DNA damage. The production of ROS was measured using the fluorescent probe dichlorofluorescein and DNA damage was evaluated by the Comet assay. Human SH-SY5Y neuroblastoma cells were exposed to RF radiation for 1 h with or without menadione. Control cultures were sham exposed. Both continuous waves (CW) and a pulsed signal similar to that used in global system for mobile communications (GSM) mobile phones were used. Exposure to the CW RF radiation increased DNA breakage (p < 0.01) in comparison to the cells exposed only to menadione. Comparison of the same groups also showed that ROS level was higher in cells exposed to CW RF radiation at 30 and 60 min after the end of exposure (p < 0.05 and p < 0.01, respectively). No effects of the GSM signal were seen on either ROS production or DNA damage. The results of the present study suggest that 872 MHz CW RF radiation at 5 W/kg might enhance chemically induced ROS production and thus cause secondary DNA damage. However, there is no known mechanism that would explain such effects from CW RF radiation but not from GSM modulated RF radiation at identical SAR

Saline-enhanced radiofrequency electrocoagulation in bovine liver

Energy Technology Data Exchange (ETDEWEB)

Shin, Hong Seop; Oh, Joo Hyeong; Yoon, Yup; Kim, Hyun Cheol; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Kim, Eui Jong [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

1997-08-01

To determine the effectiveness of saline-enhanced radiofrequency electrocoagulation in bovine liver tissue Saline-enhanced radiofrequency electrocoagulation (group I), hot saline injection induced by radiofrequency electrocoagulation (group II), and radiofrequency electrocoagulation (group III) were performed in ex vivo bovine liver. Radiofrequency power was 100 and 200 watts, and current was applied for 10, 20, and 30 seconds. Tissue was histopathologically examined for thermal injury. The largest diameter of thermal injury was about 41.0 mm in group I, 12.3 mm in group II and 9.3 mm in group III. The mean diameter of the injury increased with higher wattage in group I and II and with longer procedure time in group I (p<0.05). At corresponding wattage and times, group I showed a larger diameter of thermal injury and more increase in than group II or III (p<0.05). The degree of carbonization was more severe in group III than in groups I and II. Grossly, thermal injury showed a well-defined, relatively spherical configuration without extension along parenchymal interstitium. In an animal model, saline-enhanced radiofrequency electrocoagulation may effectively induce thermal injury, and may thus be another effective tool for use in the treatment of hepatic tumors. Further clinical experience is needed.

Saline-enhanced radiofrequency electrocoagulation in bovine liver

International Nuclear Information System (INIS)

Shin, Hong Seop; Oh, Joo Hyeong; Yoon, Yup; Kim, Hyun Cheol; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Kim, Eui Jong

1997-01-01

To determine the effectiveness of saline-enhanced radiofrequency electrocoagulation in bovine liver tissue Saline-enhanced radiofrequency electrocoagulation (group I), hot saline injection induced by radiofrequency electrocoagulation (group II), and radiofrequency electrocoagulation (group III) were performed in ex vivo bovine liver. Radiofrequency power was 100 and 200 watts, and current was applied for 10, 20, and 30 seconds. Tissue was histopathologically examined for thermal injury. The largest diameter of thermal injury was about 41.0 mm in group I, 12.3 mm in group II and 9.3 mm in group III. The mean diameter of the injury increased with higher wattage in group I and II and with longer procedure time in group I (p<0.05). At corresponding wattage and times, group I showed a larger diameter of thermal injury and more increase in than group II or III (p<0.05). The degree of carbonization was more severe in group III than in groups I and II. Grossly, thermal injury showed a well-defined, relatively spherical configuration without extension along parenchymal interstitium. In an animal model, saline-enhanced radiofrequency electrocoagulation may effectively induce thermal injury, and may thus be another effective tool for use in the treatment of hepatic tumors. Further clinical experience is needed

Effect of 905 MHz microwave radiation on colony growth of the yeast Saccharomyces cerevisiae strains FF18733, FF1481 and D7

International Nuclear Information System (INIS)

Vrhovac, Ivana; Hrascan, Reno; Franekic, Jasna

2010-01-01

The aim of this study was to evaluate the effect of weak radiofrequency microwave (RF/MW) radiation emitted by mobile phones on colony growth of the yeast Saccharomyces cerevisiae. S. cerevisiae strains FF18733 (wild-type), FF1481 (rad1 mutant) and D7 (commonly used to detect reciprocal and nonreciprocal mitotic recombinations) were exposed to a 905 MHz electromagnetic field that closely matched the Global System for Mobile Communication (GSM) pulse modulation signals for mobile phones at a specific absorption rate (SAR) of 0.12 W/kg. Following 15-, 30- and 60-minutes exposure to RF/MW radiation, strain FF18733 did not show statistically significant changes in colony growth compared to the control sample. The irradiated strains FF1481 and D7 demonstrated statistically significant reduction of colony growth compared to non-irradiated strains after all exposure times. Furthermore, strain FF1481 was more sensitive to RF/MW radiation than strain D7. The findings indicate that pulsed RF/MW radiation at a low SAR level can affect the rate of colony growth of different S. cerevisiae strains

Image-guided radiofrequency ablation of renal cell carcinoma

International Nuclear Information System (INIS)

Boss, Andreas; Clasen, Stephan; Pereira, Philippe L.; Kuczyk, Markus; Schick, Fritz

2007-01-01

The incidence of renal cell carcinoma is rising with the increased number of incidental detection of small tumours. During the past few years, percutaneous imaging-guided radiofrequency ablation has evolved as a minimally invasive treatment of small unresectable renal tumours offering reduced patient morbidity and overall health care costs. In radiofrequency ablation, thermal energy is deposited into a targeted tumour by means of a radiofrequency applicator. In recent studies, radiofrequency ablation was shown to be an effective and safe modality for local destruction of renal cell carcinoma. Radiofrequency applicator navigation can be performed via ultrasound, computed tomography or magnetic resonance guidance; however, ultrasound seems less favourable because of the absence of monitoring capabilities during ablation. On-line monitoring of treatment outcome can only be performed with magnetic resonance imaging giving the possibility of eventual applicator repositioning to ablate visible residual tumour tissue. Long-term follow-up is crucial to assess completeness of tumour ablation. New developments in ablation technology and radiological equipment will further increase the indication field for radiofrequency ablation of renal cell carcinoma. Altogether, radiofrequency ablation seems to be a promising new modality for the minimally invasive treatment of renal cell carcinoma, which was demonstrated to exhibit high short-term effectiveness. (orig.)

Annual report of the Chief Executive Officer of Australian Radiation Protection And Nuclear Safety Agency, 2001-200

International Nuclear Information System (INIS)

2002-01-01

In the period analysed ARPANSA contributed to the (then) Health and Aged Care portfolio's 'Outcome 1: Population Health and Safety'. The objective of this outcome was the promotion and protection of the health of all Australians and minimising the incidence of preventable mortality, illness, injury and disability. The main outcomes, as outlined in the reports are: regulation of Commonwealth activities involving radiation sources and nuclear facilities; progress towards the development of a National Directory for Radiation Protection; quality assurance programs in medical radiation and conduct evaluations of individual and population doses; health impact assessment of radiation exposure and methodologies for this assessment, recommendations and guidelines for limiting radiation exposure; progress towards third-party quality assurance certification for the personal radiation monitoring service, radionuclide analysis of gamma ray emitting nuclides, Ultraviolet Protection Factor; assessing radiopharmaceutical testing and the protection dosimeter calibration service; maintenance of a network for monitoring radionuclides in the atmosphere; safety standards and guidance in support of the work of the Radiation Health and Safety Advisory Council, the Radiation Health Committee and the Nuclear Safety Committee. The major priorities for ARPANSA in the reporting year, included the assessment of an application to construct the replacement research reactor at ANSTO, implementation of a process for public consultation and participation in the licensing of nuclear facilities and the development of national standards and codes of practice, including a standard for radiofrequency radiation

New-generation radiofrequency technology.

Science.gov (United States)

Krueger, Nils; Sadick, Neil S

2013-01-01

Radiofrequency (RF) technology has become a standard treatment in aesthetic medicine with many indications due to its versatility, efficacy, and safety. It is used worldwide for cellulite reduction; acne scar revision; and treatment of hypertrophic scars and keloids, rosacea, and inflammatory acne in all skin types. However, the most common indication for RF technology is the nonablative tightening of tissue to improve skin laxity and reduce wrinkles. Radiofrequency devices are classified as unipolar, bipolar, or multipolar depending on the number of electrodes used. Additional modalities include fractional RF; sublative RF; phase-controlled RF; and combination RF therapies that apply light, massage, or pulsed electromagnetic fields (PEMFs). This article reviews studies and case series on these devices. Radiofrequency technology for aesthetic medicine has seen rapid advancements since it was used for skin tightening in 2003. Future developments will continue to keep RF technology at the forefront of the dermatologist's armamentarium for skin tightening and rejuvenation.

Radiated Emissions Test Approach

Science.gov (United States)

2015-10-02

1. Draft Department of Transportation (DOT) Test Plan to Develop : Interference Tolerance Masks for GNSS Receivers in the L1 : Radiofrequency Band (1559 1610 MHz) provides high level : overview of radiated emissions test setup : 2. Presenta...

INTERACTION OF LASER RADIATION WITH MATTER: Influence of a target on operation of a pulsed CO2 laser emitting microsecond pulses

Science.gov (United States)

Baranov, V. Yu; Dolgov, V. A.; Malyuta, D. D.; Mezhevov, V. S.; Semak, V. V.

1987-12-01

The profile of pulses emitted by a TEA CO2 laser with an unstable resonator changed as a result of interaction of laser radiation with the surface of a metal in the presence of a breakdown plasma. This influence of a target on laser operation and its possible applications in laser processing of materials are analyzed.

Cytogenetic studies in human blood lymphocytes exposed in vitro to radiofrequency radiation at a cellular telephone frequency (835.62 MHz, FDMA).

Science.gov (United States)

Vijayalaxmi; Leal, B Z; Meltz, M L; Pickard, W F; Bisht, K S; Roti Roti JL; Straube, W L; Moros, E G

2001-01-01

Freshly collected peripheral blood samples from four healthy human volunteers were diluted with RPMI 1640 tissue culture medium and exposed in sterile T-75 tissue culture flasks in vitro for 24 h to 835.62 MHz radiofrequency (RF) radiation, a frequency employed for customer-to-base station transmission of cellular telephone communications. An analog signal was used, and the access technology was frequency division multiple access (FDMA, continuous wave). A nominal net forward power of 68 W was used, and the nominal power density at the center of the exposure flask was 860 W/m(2). The mean specific absorption rate in the exposure flask was 4.4 or 5.0 W/kg. Aliquots of diluted blood that were sham-exposed or exposed in vitro to an acute dose of 1.50 Gy of gamma radiation were used as negative or positive controls. Immediately after the exposures, the lymphocytes were stimulated with a mitogen, phytohemagglutinin, and cultured for 48 or 72 h to determine the extent of genetic damage, as assessed from the frequencies of chromosomal aberrations and micronuclei. The extent of alteration in the kinetics of cell proliferation was determined from the mitotic indices in 48-h cultures and from the incidence of binucleate cells in 72-h cultures. The data indicated no significant differences between RF-radiation- and sham-exposed lymphocytes with respect to mitotic indices, incidence of exchange aberrations, excess fragments, binucleate cells, and micronuclei. In contrast, the response of the lymphocytes exposed to gamma radiation was significantly different from both RF-radiation- and sham-exposed cells for all of these indices. Thus, under the experimental conditions tested, there is no evidence for the induction of chromosomal aberrations and micronuclei in human blood lymphocytes exposed in vitro for 24 h to 835.62 MHz RF radiation at SARs of 4.4 or 5.0 W/kg.

Electromagnetic radiation emitted by a plasma produced in air by laser pulses with lambda = 10.6 μm

International Nuclear Information System (INIS)

Danilychev, V.A.; Zvorykin, V.D.; Kholin, I.V.; Chugunov, A.Y.

1981-01-01

The spectrum, brightness, and energy have been measured for the electromagnetic radiation emitted by a plasma produced in air near a solid surface by pulses from a high-power CO 2 laser. The air pressure was varied over the range p 0 = 0.1--760 torr, and the laser power density was varied over the range q = 5 x 10 6 --10 8 W/cm 2 . At p 0 > or approx. =2--5 torr the radiation properties of the plasma are determined by a laser-beam absorption wave which arises in the gas. The maximum brightness temperature, T/sub b/approx. =50 000 K (lambda = 400 +- 20 nm), is reached at p 0 = 25 torr. The emission spectrum is quite different from an equilibrium spectrum, consisting primarily of NII, OII, and NIII lines. The total energy radiation by the plasma in the wavelength interval 360--2600 nm into a solid angle of 4π sr reaches 2.3% of the laser pulse energy

Measurements of Radiofrequency Radiation with a Body-Borne Exposimeter in Swedish Schools with Wi-Fi

Directory of Open Access Journals (Sweden)

Lena K. Hedendahl

2017-11-01

Full Text Available IntroductionWireless access to the Internet is now commonly used in schools. Many schools give each student their own laptop and utilize the laptops and wireless fidelity (Wi-Fi connection for educational purposes. Most children also bring their own mobile phones to school. Since children are obliged by law to attend school, a safe environment is important. Lately, it has been discussed if radiofrequency (RF radiation can have long-term adverse effects on children’s health.MethodThis study conducted exposimetric measurements in schools to assess RF emissions in the classroom by measuring the teachers’ RF exposure in order to approximate the children’s exposure. Teachers in grades 7–12 carried a body-borne exposimeter, EME-Spy 200, in school during 1–4 days of work. The exposimeter can measure 20 different frequency bands from 87 to 5,850 MHz.ResultsEighteen teachers from seven schools participated. The mean exposure to RF radiation ranged from 1.1 to 66.1 µW/m2. The highest mean level, 396.6 µW/m2, occurred during 5 min of a lesson when the teacher let the students stream and watch YouTube videos. Maximum peaks went up to 82,857 µW/m2 from mobile phone uplink.DiscussionOur measurements are in line with recent exposure studies in schools in other countries. The exposure levels varied between the different Wi-Fi systems, and if the students were allowed to use their own smartphones on the school’s Wi-Fi network or if they were connected to GSM/3G/4G base stations outside the school. An access point over the teacher’s head gave higher exposure compared with a school with a wired Internet connection for the teacher in the classroom. All values were far below International Commission on Non-Ionizing Radiation Protection’s reference values, but most mean levels measured were above the precautionary target level of 3–6 µW/m2 as proposed by the Bioinitiative Report. The length of time wireless devices are used is an

Flexible organic light-emitting device based on magnetron sputtered indium-tin-oxide on plastic substrate

International Nuclear Information System (INIS)

Wong, F.L.; Fung, M.K.; Tong, S.W.; Lee, C.S.; Lee, S.T.

2004-01-01

A radio-frequency sputtering deposition method was applied to prepare indium tin oxide (ITO) on a plastic substrate, polyethylene terephthalate (PET). The correlation of deposition conditions and ITO film properties was systematically investigated and characterized. The optimal ITO films had a transmittance of over 90% in the visible range (400-700 nm) and a resistivity of 5.0x10 -4 Ω-cm. Sequentially α-napthylphenylbiphenyl diamine, tris-(8-hydroxyquinoline) aluminium, and magnesium-silver were thermally deposited on the ITO-coated PET substrate to fabricate flexible organic light-emitting diodes (FOLEDs). The fabricated devices had a maximum current efficiency of ∼4.1 cd/A and a luminance of nearly 4100 cd/m 2 at 100 mA/cm 2 . These values showed that the FOLEDs had comparable performance characteristics with the conventional organic light-emitting diodes made on ITO-coated glasses with the same device configuration

Does the cellphone radio-frequency electromagnetic radiation ...

African Journals Online (AJOL)

Debate regarding the biological effect of electromagnetic radiation has been recently raised. The effects of this radiation on locomotor activity are not well known. Hence, in this study, we used Drosophila melanogaster as a model organism to investigate the possible effects of short-term exposure to ringing or talking ...

New Horizons in Enhancing the Proliferation and Differentiation of Neural Stem Cells Using Stimulatory Effects of the Short Time Exposure to Radiofrequency Radiation.

Science.gov (United States)

Eghlidospour, M; Mortazavi, S M J; Yousefi, F; Mortazavi, S A R

2015-09-01

Mobile phone use and wireless communication technology have grown explosively over the past decades. This rapid growth has caused widespread global concern about the potential detrimental effects of this technology on human health. Stem cells generate specialized cell types of the tissue in which they reside through normal differentiation pathways. Considering the undeniable importance of stem cells in modern medicine, numerous studies have been performed on the effects of ionizing and non-ionizing radiation on cellular processes such as: proliferation, differentiation, cell cycle and DNA repair processes. We have conducted extensive studies on beneficial (stimulatory) or detrimental biological effects of exposure to different sources of electromagnetic fields such as mobile phones, mobile phone base stations, mobile phone jammers, radar systems, magnetic resonance imaging (MRI) systems and dentistry cavitrons over the past years. In this article, recent studies on the biological effects of non-ionizing electromagnetic radiation in the range of radiofrequency (RF) on some important features of stem cells such as their proliferation and differentiation are reviewed. Studies reviewed in this paper indicate that the stimulatory or inhibitory effects of RF radiation on the proliferation and differentiation of stem cells depend on various factors such as the biological systems, experiment conditions, the frequency and intensity of RF and the duration of exposure.

Infrared Radiation and Blackbody Radiation

OpenAIRE

2005-01-01

tut present graph Tutorial Presentation Graph Interactive Media Element This interactive tutorial covers the following: How infrared radiation was discovered., The regions of infrared radiation and their relations to temperature., The nature of blackbody radiation and Planck's radiation law., The relationship between temperature and the power emitted by radiation.The interactions in this tutorial include clicking to reveal new information, and questions that help students...

78 FR 25916 - Authorization of Radiofrequency Equipment

Science.gov (United States)

2013-05-03

...] Authorization of Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Proposed rule... bodies, and measurement procedures used to determine RF equipment compliance. The Commission believes... Commission is responsible for an equipment authorization program for radiofrequency (RF) devices under part 2...

Radiofrequency initiation and radiofrequency sustainment of laser initiated seeded high pressure plasma

International Nuclear Information System (INIS)

Paller, Eric S.; Scharer, John E.; Akhtar, Kamran; Kelly, Kurt; Ding, Guowen

2001-01-01

We examine radiofrequency initiation of high pressure(1-70 Torr) inductive plasma discharges in argon, nitrogen, air and organic seed gas mixtures. Millimeter wave interferometry, optical emission and antenna wave impedance measurements for double half-turn helix and helical inductive antennas are used to interpret the rf/plasma coupling, measure the densities in the range of 10 12 cm -3 and analyze the ionization and excited states of the gas mixtures. We have also carried out 193 nm excimer laser initiation of an organic gas seed plasma which is sustained at higher pressures(150 Torr) by radiofrequency coupling at 2.8 kW power levels

Lifetime enhanced phosphorescent organic light emitting diode using an electron scavenger layer

Energy Technology Data Exchange (ETDEWEB)

Hong, Seokhwan; Kim, Ji Whan; Lee, Sangyeob, E-mail: sy96.lee@samsung.com [Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., 130 Samsung-ro, Suwon, Gyeonggi 443-803 (Korea, Republic of)

2015-07-27

We demonstrate a method to improve lifetime of a phosphorescent organic light emitting diode (OLED) using an electron scavenger layer (ESL) in a hole transporting layer (HTL) of the device. We use a bis(1-(phenyl)isoquinoline)iridium(III)acetylacetonate [Ir(piq){sub 2}(acac)] doped HTL to stimulate radiative decay, preventing thermal degradation in HTL. The ESL effectively prevented non-radiative decay of leakage electron in HTL by converting non-radiative decay to radiative decay via a phosphorescent red emitter, Ir(piq){sub 2}(acac). The lifetime of device (t{sub 95}: time after 5% decrease of luminance) has been increased from 75 h to 120 h by using the ESL in a phosphorescent green-emitting OLED.

Shining light on radiation detection and energy transfer : Triazole ligands used for detection of radiation and lanthanide binding

NARCIS (Netherlands)

Dijkstra, Peter

2016-01-01

Some substances, fluorophores, absorb light and then emit that light again as fluorescence. Apart from absorption of light, some of these substances can also emit light after having absorbed energy from radiation. A substance which can absorb radiation and emit the energy as light is called a

Code of practice for safety in laboratory - non ionising radiation

International Nuclear Information System (INIS)

Ramli Jaya; Mohd Yusof Mohd Ali; Khoo Boo Huat; Khatijah Hashim

1995-01-01

The code identifies the non-ionizing radiation encountered in laboratories and the associated hazards. The code is intended as a laboratory standard reference document for general information on safety requirements relating to the usage of non-ionizing radiations in laboratories. The nonionizing radiations cover in this code, namely, are ultraviolet radiation, visible light, radio-frequency radiation, lasers, sound waves and ultrasonic radiation. (author)

Top-emitting organic light-emitting diodes.

Science.gov (United States)

Hofmann, Simone; Thomschke, Michael; Lüssem, Björn; Leo, Karl

2011-11-07

We review top-emitting organic light-emitting diodes (OLEDs), which are beneficial for lighting and display applications, where non-transparent substrates are used. The optical effects of the microcavity structure as well as the loss mechanisms are discussed. Outcoupling techniques and the work on white top-emitting OLEDs are summarized. We discuss the power dissipation spectra for a monochrome and a white top-emitting OLED and give quantitative reports on the loss channels. Furthermore, the development of inverted top-emitting OLEDs is described.

Hyperkalaemia after radiofrequency ablation of hepatocellular carcinoma

NARCIS (Netherlands)

Verhoevena, BH; Haagsma, EB; Appeltans, BMG; Slooff, MJH; de Jong, KP

Radiofrequency ablation of liver tumours is a useful therapy for otherwise unresectable tumours. The complication rate is said to be low. In this case report we describe hyperkalaemia after radiofrequency ablation of a hepatocellular carcinoma in a patient with end-stage renal insufficiency. (C)

New Radiofrequency Exposure System with Real Telecommunication Signals

Directory of Open Access Journals (Sweden)

Jakub Misek

2018-01-01

Full Text Available In recent years, there has been an increase in the number of studies on biological effects of Electromagnetic (EM fields emitted from Base Transceiver Stations (BTSs. The biological effects of generated and real telecommunication signals produced by different types of exposure systems are discussed. However, the proper exposure methods for such experiments are very limited. We successfully developed a simple and cost-effective exposure unit with real GSM/DCS/UMTS signal from BTS containing proper modulations or intermittence (continuous, interrupted. Signal processing and conditioning unit is based on a Radiofrequency (RF repeater. The downlink signal is filtered by integrated high selectivity passband filters and amplified to a required level. The main part of exposure unit is a Faraday cage with the specimen (exposure area measuring 150 x 250 mm with E-field percent deviation less than 18%. This exposure system can be helpful in experiments with living organisms in in vivo studies and in vitro studies with normal or pathological cells and other micro scale structures being exposed to RF EM fields from BTS.

Ab initio investigation of barium-scandium-oxygen coatings on tungsten for electron emitting cathodes

Science.gov (United States)

Vlahos, Vasilios; Booske, John H.; Morgan, Dane

2010-02-01

Microwave, x-ray, and radio-frequency radiation sources require a cathode emitting electrons into vacuum. Thermionic B-type dispenser cathodes consist of BaxOz coatings on tungsten (W), where the surface coatings lower the W work function and enhance electron emission. The new and promising class of scandate cathodes modifies the B-type surface through inclusion of Sc, and their superior emissive properties are also believed to stem from the formation of a low work function surface alloy. In order to better understand these cathode systems, density-functional theory (DFT)-based ab initio modeling is used to explore the stability and work function of BaxScyOz on W(001) monolayer-type surface structures. It is demonstrated how surface depolarization effects can be calculated easily using ab initio calculations and fitted to an analytic depolarization equation. This approach enables the rapid extraction of the complete depolarization curve (work function versus coverage relation) from relatively few DFT calculations, useful for understanding and characterizing the emitting properties of novel cathode materials. It is generally believed that the B-type cathode has some concentration of Ba-O dimers on the W surface, although their structure is not known. Calculations suggest that tilted Ba-O dimers are the stable dimer surface configuration and can explain the observed work function reduction corresponding to various dimer coverages. Tilted Ba-O dimers represent a new surface coating structure not previously proposed for the activated B-type cathode. The thermodynamically stable phase of Ba and O on the W surface was identified to be the Ba0.25O configuration, possessing a significantly lower Φ value than any of the Ba-O dimer configurations investigated. The identification of a more stable Ba0.25O phase implies that if Ba-O dimers cover the surface of emitting B-type cathodes, then a nonequilibrium steady state must dominate the emitting surface. The identification of

Radio-frequency integrated-circuit engineering

CERN Document Server

Nguyen, Cam

2015-01-01

Radio-Frequency Integrated-Circuit Engineering addresses the theory, analysis and design of passive and active RFIC's using Si-based CMOS and Bi-CMOS technologies, and other non-silicon based technologies. The materials covered are self-contained and presented in such detail that allows readers with only undergraduate electrical engineering knowledge in EM, RF, and circuits to understand and design RFICs. Organized into sixteen chapters, blending analog and microwave engineering, Radio-Frequency Integrated-Circuit Engineering emphasizes the microwave engineering approach for RFICs. Provide

Radiofrequency catheter oblation in atrial flutter

International Nuclear Information System (INIS)

Yan Ji; Wang Heping; Xu Jian; Liu Fuyuan; Fan Xizhen; An Chunsheng; Han Xiaoping; Ding Xiaomei; Wang Jiasheng; Gu Tongyuan

2002-01-01

Objective: To evaluate the radiofrequency catheter ablation for type I atrial flutter through application of Holo catheter labelling with anatomic imaging localization to ablate the isthmus of IVCTA during complete double-way block. Methods: Eleven cases with type I atrial flutter undergone Holo catheter labelling technique and consecution with conduction time change of coronary venous sinus orifice with-right atrial lower lateral wall pace excitation, were performed with radiofrequency catheter ablation for the isthmus outcoming with complete double-way conduction block. Results: All together 11 cases with 4 of atrial flutter and 7 of sinus rhythm were undergone radiofrequency catheter ablation resulting with double-way conduction block of the isthmus accompanied by prolongation of right atrial conduction time 56.0 ± 2.3 ms and 53.0 ± 4.6 ms respectively. The right atrial excitation appeared to be in clockwise and counter-clockwise of single direction. No recurrence occurred during 3-34 months follow up with only one showing atrial fibrillation. Conclusions: The application of Holo catheter labelling technique with anatomic imaging localization to achieve the double-way conduction block by radiofrequency catheter ablation of TVC-TA isthmus, is a reliable method for treating atrial flutter

Comparison of bone tumors induced by beta-emitting or alpha-emitting radionuclides: Schemes of pathogenesis

International Nuclear Information System (INIS)

Gillett, N.A.; Muggenburg, B.A.; Pool, R.R.; Hahn, F.F.

1988-01-01

Life-span studies in Beagle dogs have documented the occurrence of bone tumors following exposure to bone-seeking alpha- or beta-emitting radionuclides administered by different routes of exposure. Bone tumors from dogs in four different life-span studies were analyzed according to tumor phenotype, tumor location, radiographic appearance, incidence of metastasis, and association with radiation osteodystrophy. Marked differences in these parameters were observed that did not correlate with differences in radionuclide type, route of exposure, or duration of radionuclide uptake. Radiation osteodystrophy, which is postulated to be a preneoplastic lesion, was not a significant component in one of the studies. Analysis of the data from these four studies suggests that at least two different mechanisms of bone tumor pathogenesis occur for radiation-induced bone tumors. (author)

Reprint of 'Evaluation of Scattered Radiation Emitted From X-ray Security Scanners on Occupational Dose to Airport Personnel'

Science.gov (United States)

Dalah, Entesar; Fakhry, Angham; Mukhtar, Asma; Al Salti, Farah; Bader, May; Khouri, Sara; Al-Zahmi, Reem

2017-11-01

Based on security issues and regulations airports are provided with luggage cargo scanners. These scanners utilize ionizing radiation that in principle present health risks toward humans. The study aims to investigate the amount of backscatter produced by passenger luggage and cargo toward airport personnel who are located at different distances from the scanners. To approach our investigation a Thermo Electron Radeye-G probe was used to quantify the backscattered radiation measured in terms of dose-rate emitted from airport scanners, Measurements were taken at the entrance and exit positions of the X-ray tunnel at three different distances (0, 50, and 100 cm) for two different scanners; both scanners include shielding curtains that reduce scattered radiation. Correlation was demonstrated using the Pearson coefficient test. Measurements confirmed an inverse relationship between dose rate and distance. An estimated occupational accumulative dose of 0.88 mSv/y, and 2.04 mSv/y were obtained for personnel working in inspection of carry-on, and cargo, respectively. Findings confirm that the projected dose of security and engineering staff are being well within dose limits.

Non-surgical radiofrequency facelift.

Science.gov (United States)

Narins, David J; Narins, Rhoda S

2003-10-01

There has been considerable interest in using non-ablative methods to rejuvenate the skin. The ThermaCool TC (Thermage Inc.) is a radiofrequency (RF) device that has been introduced to induce tightening of the address the problem of skin via a uniform volumetric heating into the deep dermis tightening, resulting in a 'non-surgical facelift'. Radiofrequency produces a uniform volumetric heating into the deep dermis. Twenty treatment areas in 17 patients were treated to evaluate the efficacy and safety of RF treatment to the brow and jowls. The technique was found to produce gradual tightening in most patients, and there were no adverse effects.

21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological signal...

Diverse radiofrequency sensitivity and radiofrequency effects of mobile or cordless phone near fields exposure in Drosophila melanogaster.

Science.gov (United States)

Geronikolou, Styliani; Zimeras, Stelios; Davos, Constantinos H; Michalopoulos, Ioannis; Tsitomeneas, Stephanos

2014-01-01

The impact of electromagnetic fields on health is of increasing scientific interest. The aim of this study was to examine how the Drosophila melanogaster animal model is affected when exposed to portable or mobile phone fields. Two experiments have been designed and performed in the same laboratory conditions. Insect cultures were exposed to the near field of a 2G mobile phone (the GSM 2G networks support and complement in parallel the 3G wide band or in other words the transmission of information via voice signals is served by the 2G technology in both mobile phones generations) and a 1880 MHz cordless phone both digitally modulated by human voice. Comparison with advanced statistics of the egg laying of the second generation exposed and non-exposed cultures showed limited statistical significance for the cordless phone exposed culture and statistical significance for the 900 MHz exposed insects. We calculated by physics, simulated and illustrated in three dimensional figures the calculated near fields of radiation inside the experimenting vials and their difference. Comparison of the power of the two fields showed that the difference between them becomes null when the experimental cylinder radius and the height of the antenna increase. Our results suggest a possible radiofrequency sensitivity difference in insects which may be due to the distance from the antenna or to unexplored intimate factors. Comparing the near fields of the two frequencies bands, we see similar not identical geometry in length and height from the antenna and that lower frequencies tend to drive to increased radiofrequency effects.

Nanometer-scale elongation rate fluctuations in the Myriophyllum aquaticum (Parrot feather) stem were altered by radio-frequency electromagnetic radiation.

Science.gov (United States)

Senavirathna, Mudalige Don Hiranya Jayasanka; Asaeda, Takashi; Thilakarathne, Bodhipaksha Lalith Sanjaya; Kadono, Hirofumi

2014-01-01

The emission of radio-frequency electromagnetic radiation (EMR) by various wireless communication base stations has increased in recent years. While there is wide concern about the effects of EMR on humans and animals, the influence of EMR on plants is not well understood. In this study, we investigated the effect of EMR on the growth dynamics of Myriophyllum aquaticum (Parrot feather) by measuring the nanometric elongation rate fluctuation (NERF) using a statistical interferometry technique. Plants were exposed to 2 GHz EMR at a maximum of 1.42 Wm(-2) for 1 h. After continuous exposure to EMR, M. aquaticum plants exhibited a statistically significant 51 ± 16% reduction in NERF standard deviation. Temperature observations revealed that EMR exposure did not cause dielectric heating of the plants. Therefore, the reduced NERF was due to a non-thermal effect caused by EMR exposure. The alteration in NERF continued for at least 2.5 h after EMR exposure and no significant recovery was found in post-EMR NERF during the experimental period.

Assessment of Radiofrequency Radiation Distribution around Mobile Base Stations in Makurdi, Benue State

OpenAIRE

J.T. Iortile; E.H. Agba

2014-01-01

The radiofrequency field levels of selected MTN and ZAIN base stations in Makurdi were measured using electromagnetic field tester (EMF 827, Lutron). Measurements were done at distances of approximately 5.00, 10.00, 15.00 and 20.00 metres for each base station at the North, South, West, and East directions. Results shows that the average magnetic field levels of MTN and ZAIN base station ranged between 0.09 μT to 0.15 μT. The mean electric field values for eye, brain and muscles ranged betwee...

How I do it-optimizing radiofrequency ablation in spinal metastases using iCT and navigation.

Science.gov (United States)

Kavakebi, Pujan; Freyschlag, C F; Thomé, C

2017-10-01

Exact positioning of the radiofrequency ablation (RFA) probe for tumor treatment under fluoroscopic guidance can be difficult because of potentially small inaccessible lesions and the radiation dose to the medical staff in RFA. In addition, vertebroplasty (VP) can be significantly high. Description and workflow of RFA in spinal metastasis using iCT (intraoperative computed tomography) and 3D-navigation-based probe placement followed by VP. RFA and VP can be successfully combined with iCT-based navigation, which leads to a reduction of radiation to the staff and optimal probe positioning due to 3D navigation.

Radiofrequency-thermoablation in malignant liver disease

International Nuclear Information System (INIS)

Pichler, L.; Anzboeck, W.; Paertan, G.; Hruby, W.

2002-01-01

The clinical application of radiofrequency tumor ablation in primary liver tumors and metastatic liver disease is rapidly growing because this technique has proven to be simple, safe, and effective in first clinical studies. Most of the patients with malignant liver disease are not candidates for surgical resection due localisation or comorbidity, so radiofrequency therapy offers a good alternative for inoperable patients. With this method, high frequency alternating current is delivered to tissue via a needle electrode, the produced heat leads to coagulation necrosis. The largest focus of necrosis that can be induced with the currently available systems is approximately 4-5 cm with a single application. The radiofrequency needle is usually placed with US or CT guidance. For follow up examinations CT and MRI can be used, they proved to be equally accurate in the assessment of treatment response. (orig.) [de

Fractionated bipolar radiofrequency and bipolar radiofrequency potentiated by infrared light for treating striae: A prospective randomized, comparative trial with objective evaluation.

Science.gov (United States)

Harmelin, Yona; Boineau, Dominique; Cardot-Leccia, Nathalie; Fontas, Eric; Bahadoran, Philippe; Becker, Anne-Lise; Montaudié, Henri; Castela, Emeline; Perrin, Christophe; Lacour, Jean-Philippe; Passeron, Thierry

2016-03-01

Very few treatments for striae are based on prospective randomized trials. The objective of this study was to assess the efficacy of bipolar fractional radiofrequency and bipolar radiofrequency potentiated with infrared light, alone or combined, for treating abdominal stretch marks. Bicentric prospective interventional randomized controlled trial in the department of Dermatology of University Hospital of Nice and Aesthetics Laser Center of Bordeaux, France. Men and women of age 18 years or above, who presented for the treatment of mature or immature abdominal striae were included. The patients' abdomens were divided into four equal quadrants. Bipolar radiofrequency potentiated with infrared light and fractional bipolar radiofrequency were applied, alone or combined, and compared to the remaining untreated quadrant. The main criterion of evaluation was the measurement of depth of striae, using 3D photography at 6 months follow-up. A global assessment was also rated by the physician performing the treatment and by the patients. Histological analysis and confocal laser microscopy were additionally performed. A total of 22 patients were enrolled, and 384 striae were measured. In per protocol analysis mean striae depth was decreased by 21.64%, observed at 6 months follow-up with the combined approach, compared to an increase of 1.73% in the control group (P radiofrequency, combined with bipolar radiofrequency potentiated by infrared light, is an effective treatment of both immature and mature striae of the abdomen. © 2016 Wiley Periodicals, Inc.

Temperature-controlled radiofrequency ablation of cardiac tissue

DEFF Research Database (Denmark)

Petersen, H H; Chen, X; Pietersen, Adrian

1999-01-01

BACKGROUND: A variety of basic factors such as electrode tip pressure, flow around the electrode and electrode orientation influence lesion size during radiofrequency ablation, but importantly is dependent on the chosen mode of ablation. However, only little information is available for the frequ......BACKGROUND: A variety of basic factors such as electrode tip pressure, flow around the electrode and electrode orientation influence lesion size during radiofrequency ablation, but importantly is dependent on the chosen mode of ablation. However, only little information is available...... for the frequently used temperature-controlled mode. The purpose of the present experimental study was to evaluate the impact during temperature-controlled radiofrequency ablation of three basic factors regarding electrode-tissue contact and convective cooling on lesion size. METHODS AND RESULTS: In vitro strips......-controlled radiofrequency ablation increased external cooling of the electrode tip due to either flow of the surrounding liquid or poor electrode tissue contact, as exemplified by perpendicular versus parallel electrode orientation, increases lesion size significantly. This is in contrast to the impact of these factors...

Pulsed Radiofrequency Ablation for Treating Sural Neuralgia.

Science.gov (United States)

Abd-Elsayed, Alaa; Jackson, Markus; Plovanich, Elizabeth

2018-01-01

Sural neuralgia is persistent pain in the distribution of the sural nerve that provides sensation to the lateral posterior corner of the leg, lateral foot, and fifth toe. Sural neuralgia is a rare condition but can be challenging to treat and can cause significant limitation. We present 2 cases of sural neuralgia resistant to conservative management that were effectively treated by pulsed radiofrequency ablation. A 65-year-old female developed sural neuralgia after a foot surgery and failed conservative management. She had successful sural nerve blocks, and pulsed radiofrequency ablation led to an 80% improvement in her pain. A 33-year-old female presented with sural neuralgia secondary to two falls. The patient had tried several conservative modalities with no success. We performed diagnostic blocks and pulsed radiofrequency ablation, and the patient reported 80% improvement in her pain. Pulsed radiofrequency ablation may be a safe and effective treatment for patients with sural neuralgia that does not respond to conservative therapy. However, studies are needed to elucidate its effectiveness and safety profile.

Overview of a benefit/risk ratio optimized for a radiation emitting device used in non-destructive testing

Energy Technology Data Exchange (ETDEWEB)

Maharaj, H.P., E-mail: H_P_Maharaj@hc-sc.gc.ca [Health Canada, Dept. of Health, Consumer and Clinical Radiaton Protection Bureau, Ottawa, Ontario (Canada)

2016-03-15

This paper aims to provide an overview of an optimized benefit/risk ratio for a radiation emitting device. The device, which is portable, hand-held, and open-beam x-ray tube based, is utilized by a wide variety of industries for purposes of determining elemental or chemical analyses of materials in-situ based on fluorescent x-rays. These analyses do not cause damage or permanent alteration of the test materials and are considered a non-destructive test (NDT). Briefly, the key characteristics, principles of use and radiation hazards associated with the Hay device are presented and discussed. In view of the potential radiation risks, a long term strategy that incorporates risk factors and guiding principles intended to mitigate the radiation risks to the end user was considered and applied. Consequently, an operator certification program was developed on the basis of an International Standards Organization (ISO) standard (ISO 20807:2004) and in collaboration with various stake holders and was implemented by a federal national NDT certification body several years ago. It comprises a written radiation safety examination and hands-on training with the x-ray device. The operator certification program was recently revised and the changes appear beneficial. There is a fivefold increase in operator certification (Levels 1 a nd 2) to date compared with earlier years. Results are favorable and promising. An operational guidance document is available to help mitigate radiation risks. Operator certification in conjunction with the use of the operational guidance document is prudent, and is recommended for end users of the x-ray device. Manufacturers and owners of the x-ray devices will also benefit from the operational guidance document. (author)

Overview of a benefit/risk ratio optimized for a radiation emitting device used in non-destructive testing

International Nuclear Information System (INIS)

Maharaj, H.P.

2016-01-01

This paper aims to provide an overview of an optimized benefit/risk ratio for a radiation emitting device. The device, which is portable, hand-held, and open-beam x-ray tube based, is utilized by a wide variety of industries for purposes of determining elemental or chemical analyses of materials in-situ based on fluorescent x-rays. These analyses do not cause damage or permanent alteration of the test materials and are considered a non-destructive test (NDT). Briefly, the key characteristics, principles of use and radiation hazards associated with the Hay device are presented and discussed. In view of the potential radiation risks, a long term strategy that incorporates risk factors and guiding principles intended to mitigate the radiation risks to the end user was considered and applied. Consequently, an operator certification program was developed on the basis of an International Standards Organization (ISO) standard (ISO 20807:2004) and in collaboration with various stake holders and was implemented by a federal national NDT certification body several years ago. It comprises a written radiation safety examination and hands-on training with the x-ray device. The operator certification program was recently revised and the changes appear beneficial. There is a fivefold increase in operator certification (Levels 1 a nd 2) to date compared with earlier years. Results are favorable and promising. An operational guidance document is available to help mitigate radiation risks. Operator certification in conjunction with the use of the operational guidance document is prudent, and is recommended for end users of the x-ray device. Manufacturers and owners of the x-ray devices will also benefit from the operational guidance document. (author)

NEW Fe IX LINE IDENTIFICATIONS USING SOLAR AND HELIOSPHERIC OBSERVATORY/SOLAR ULTRAVIOLET MEASUREMENT OF EMITTED RADIATION AND HINODE/EIS JOINT OBSERVATIONS OF THE QUIET SUN

International Nuclear Information System (INIS)

Landi, E.; Young, P. R.

2009-01-01

In this work, we study joint observations of Hinode/EUV Imaging Spectrometer (EIS) and Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation of Fe IX lines emitted by the same level of the high energy configuration 3s 2 3p 5 4p. The intensity ratios of these lines are dependent on atomic physics parameters only and not on the physical parameters of the emitting plasma, so that they are excellent tools to verify the relative intensity calibration of high-resolution spectrometers that work in the 170-200 A and 700-850 A wavelength ranges. We carry out extensive atomic physics calculations to improve the accuracy of the predicted intensity ratio, and compare the results with simultaneous EIS-SUMER observations of an off-disk quiet Sun region. We were able to identify two ultraviolet lines in the SUMER spectrum that are emitted by the same level that emits one bright line in the EIS wavelength range. Comparison between predicted and measured intensity ratios, wavelengths and energy separation of Fe IX levels confirms the identifications we make. Blending and calibration uncertainties are discussed. The results of this work are important for cross-calibrating EIS and SUMER, as well as future instrumentation.

Synchroton Radiation Sources

International Nuclear Information System (INIS)

Hulbert, S.L.; Williams, G.P.

1998-01-01

Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light

The radiofrequency frontier: a review of radiofrequency and combined radiofrequency pulsed-light technology in aesthetic medicine.

Science.gov (United States)

Sadick, Neil; Sorhaindo, Lian

2005-05-01

Radiofrequency (RF) and combined RF light source technologies have established themselves as safe and effective treatment modalities for several dermatologic procedures, including skin tightening, hair and leg vein removal, acne scarring, skin rejuvenation, and wrinkle reduction. This article reviews the technology, clinical applications, and recent advances of RF and combined RF light/laser source technologies in aesthetic medicine.

Non-Ionizing Radiation - sources, exposure and health effects

International Nuclear Information System (INIS)

Hietanen, M.

2003-01-01

Non-ionizing radiation contains the electromagnetic wavelengths from ultraviolet (UV) radiation to static electric and magnetic fields. Optical radiation consists of UV, visible and infrared (IR) radiation while EM fields include static, extremely low (ELF), low frequency (LF) and radiofrequency (RF) fields. The principal scientific organization on non-ionizing radiation is the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The main activity of ICNIRP is to provide guidance on safe exposure and protection of workers and members of the public by issuing statements and recommendations. (orig.)

Comprehensive evaluation of the Berthold LB1200 survey meter

International Nuclear Information System (INIS)

Davis, M.W.

1986-05-01

The performance of two Berthod LB1200 survey meters was evaluated under the influence of a range of beta and photon radiation energies and environmental conditions likely to be encountered in the field. The survey meters responded satisfactorily to the range of beta particle and photon radiation energies emitted by most radioisotopes commonly used in Canada. The survey meters performed acceptably under most of the environmental conditions tested here with the exception of radiofrequency interference and electrostatic charge

Ultraviolet light-emitting diodes in water disinfection.

Science.gov (United States)

Vilhunen, Sari; Särkkä, Heikki; Sillanpää, Mika

2009-06-01

The novel system of ultraviolet light-emitting diodes (UV LEDs) was studied in water disinfection. Conventional UV lamps, like mercury vapor lamp, consume much energy and are considered to be problem waste after use. UV LEDs are energy efficient and free of toxicants. This study showed the suitability of LEDs in disinfection and provided information of the effect of two emitted wavelengths and different test mediums to Escherichia coli destruction. Common laboratory strain of E. coli (K12) was used and the effects of two emitted wavelengths (269 and 276 nm) were investigated with two photolytic batch reactors both including ten LEDs. The effects of test medium were examined with ultrapure water, nutrient and water, and nutrient and water with humic acids. Efficiency of reactors was almost the same even though the one emitting higher wavelength had doubled optical power compared to the other. Therefore, the effect of wavelength was evident and the radiation emitted at 269 nm was more powerful. Also, the impact of background was studied and noticed to have only slight deteriorating effect. In the 5-min experiment, the bacterial reduction of three to four log colony-forming units (CFU) per cubic centimeter was achieved, in all cases. When turbidity of the test medium was greater, part of the UV radiation was spent on the absorption and reactions with extra substances on liquid. Humic acids can also coat the bacteria reducing the sensitivity of the cells to UV light. The lower wavelength was distinctly more efficient when the optical power is considered, even though the difference of wavelengths was small. The reason presumably is the greater absorption of DNA causing more efficient bacterial breakage. UV LEDs were efficient in E. coli destruction, even if LEDs were considered to have rather low optical power. The effect of wavelengths was noticeable but the test medium did not have much impact. This study found UV LEDs to be an optimal method for bacterial

GSM 900 MHz Microwave RadiationInduced Alterations of Insulin Level and Histopathological Changes of Liver and Pancreas in Rat

Directory of Open Access Journals (Sweden)

Mortazavi S. M. J.

2016-12-01

Full Text Available Background: The rapidly increasing use of mobile phones has led to public concerns about possible health effects of these popular communication devices. This study is an attempt to investigate the effects of radiofrequency (RF radiation produced by GSM mobile phones on the insulin release in rats. Methods: Forty two female adult Sprague Dawley rats were randomly divided into 4 groups. Group1 were exposed to RF radiation 6 hours per day for 7 days. Group 2 received sham exposure (6 hours per day for 7 days. Groups 3 and 4 received RF radiation 3 hours per day for 7 days and sham exposure (3 hours per day, respectively. The specific absorption rate (SAR of RF was 2.0W/kg. Results: Our results showed that RF radiations emitted from mobile phone could not alter insulin release in rats. However, mild to severe inflammatory changes in the portal spaces of the liver of rats as well as damage in the cells of islet of Langerhans were observed. These changes were linked with the duration of the exposures. Conclusion: RF exposure can induce inflammatory changes in the liver as well causing damage in the cells of islet of Langerhans.

Treatment of acne vulgaris with fractional radiofrequency microneedling.

Science.gov (United States)

Kim, Sang Tae; Lee, Kang Hoon; Sim, Hyung Jun; Suh, Kee Suck; Jang, Min Soo

2014-07-01

Fractional radiofrequency microneedling is a novel radiofrequency technique that uses insulated microneedles to deliver energy to the deep dermis at the point of penetration without destruction of the epidermis. It has been used for the treatment of various dermatological conditions including wrinkles, atrophic scars and hypertrophic scars. There have been few studies evaluating the efficacy of fractional radiofrequency microneedling in the treatment of acne, and none measuring objective parameters like the number of inflammatory and non-inflammatory acne lesions or sebum excretion levels. The safety and efficacy of fractional radiofrequency microneedling in the treatment of acne vulgaris was investigated. In a prospective clinical trial, 25 patients with moderate to severe acne were treated with fractional radiofrequency microneedling. The procedure was carried out three times at 1-month intervals. Acne lesion count, subjective satisfaction score, sebum excretion level and adverse effects were assessed at baseline and at 4, 8 and 12 weeks after the first treatment as well as 4, 8 and 12 weeks after the last treatment. Number of acne lesions (inflammatory and non-inflammatory) decreased. Sebum excretion and subjective satisfaction were more favorable at every time point compared with the baseline values (P acne vulgaris. © 2014 Japanese Dermatological Association.

Radiofrequency protection guidelines and standards: basic concepts and principles

International Nuclear Information System (INIS)

Czerski, P.

1985-01-01

Over the past quarter of a century, radiofrequency radiation protection guidelines and standards evolved gradually and are continuously revised and refined. The scientific rationales presented for proposed exposure limits are achieving a considerable scientific sophistication. With increasing scientific validity of the presented arguments, the values of exposure limits are converging and one may hope that they will become convincing and acceptable to all schools of thought. Still more research is needed to refine the available exposure limits. This is recognized by ANSI who revise their recommendations periodically and are now engaged in the preparation of the next revision. INIRC/IRPA is also reconsidering their interim guideline. The Australian Standards Association also stressed the temporary nature of their exposure limits

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

Directory of Open Access Journals (Sweden)

Seyed Mohammad Javad Mortazavi

2017-04-01

Full Text Available Background: Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium, Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6 mm; it was 14.7 (SD 0.6 mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

Science.gov (United States)

Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

2017-04-01

Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium ( S. typhimurium ), Staphylococcus aureus , and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

Diverse Radiofrequency Sensitivity and Radiofrequency Effects of Mobile or Cordless Phone near Fields Exposure in Drosophila melanogaster

Science.gov (United States)

Geronikolou, Styliani; Zimeras, Stelios; Davos, Constantinos H.; Michalopoulos, Ioannis; Tsitomeneas, Stephanos

2014-01-01

Introduction The impact of electromagnetic fields on health is of increasing scientific interest. The aim of this study was to examine how the Drosophila melanogaster animal model is affected when exposed to portable or mobile phone fields. Methods/Results Two experiments have been designed and performed in the same laboratory conditions. Insect cultures were exposed to the near field of a 2G mobile phone (the GSM 2G networks support and complement in parallel the 3G wide band or in other words the transmission of information via voice signals is served by the 2G technology in both mobile phones generations) and a 1880 MHz cordless phone both digitally modulated by human voice. Comparison with advanced statistics of the egg laying of the second generation exposed and non-exposed cultures showed limited statistical significance for the cordless phone exposed culture and statistical significance for the 900 MHz exposed insects. We calculated by physics, simulated and illustrated in three dimensional figures the calculated near fields of radiation inside the experimenting vials and their difference. Comparison of the power of the two fields showed that the difference between them becomes null when the experimental cylinder radius and the height of the antenna increase. Conclusions/Significance Our results suggest a possible radiofrequency sensitivity difference in insects which may be due to the distance from the antenna or to unexplored intimate factors. Comparing the near fields of the two frequencies bands, we see similar not identical geometry in length and height from the antenna and that lower frequencies tend to drive to increased radiofrequency effects. PMID:25402465

Diverse radiofrequency sensitivity and radiofrequency effects of mobile or cordless phone near fields exposure in Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Styliani Geronikolou

Full Text Available INTRODUCTION: The impact of electromagnetic fields on health is of increasing scientific interest. The aim of this study was to examine how the Drosophila melanogaster animal model is affected when exposed to portable or mobile phone fields. METHODS/RESULTS: Two experiments have been designed and performed in the same laboratory conditions. Insect cultures were exposed to the near field of a 2G mobile phone (the GSM 2G networks support and complement in parallel the 3G wide band or in other words the transmission of information via voice signals is served by the 2G technology in both mobile phones generations and a 1880 MHz cordless phone both digitally modulated by human voice. Comparison with advanced statistics of the egg laying of the second generation exposed and non-exposed cultures showed limited statistical significance for the cordless phone exposed culture and statistical significance for the 900 MHz exposed insects. We calculated by physics, simulated and illustrated in three dimensional figures the calculated near fields of radiation inside the experimenting vials and their difference. Comparison of the power of the two fields showed that the difference between them becomes null when the experimental cylinder radius and the height of the antenna increase. CONCLUSIONS/SIGNIFICANCE: Our results suggest a possible radiofrequency sensitivity difference in insects which may be due to the distance from the antenna or to unexplored intimate factors. Comparing the near fields of the two frequencies bands, we see similar not identical geometry in length and height from the antenna and that lower frequencies tend to drive to increased radiofrequency effects.

The exemption from the requirement of registration and/or licensing of some sources. machines and devices emitting ionizing and /or on ionizing radiation: a proposed draft for Israeli regulations

Energy Technology Data Exchange (ETDEWEB)

Schlesinger, T; Margaliot, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

1997-11-16

The licensing and authorization of the import, purchase, distribution, transportation and application of radioactive materials and devices emitting ionizing and/or non-ionizing radiation are carried out in Israel by the Ministries of the Environment and of Health. The legal basis for file authority of these Ministries in radiation protection matters is file {sup P}harmacists Regulation- Radioactive Elements and Products Thereof, 1981 (revision 1994) (PRREPT). Licenses are issued by the Chief Radiation Executive (CUE) appointed by the Minister of the Environment and the Minister of Health. The Regulations include a clause which enables the CUE to exempt certain amounts of radioactive materials from file requirements laid down in the PRREPT. The exemption clause is general and does not indicate the types and amounts of radioactive material may be exempted. The proposed draft Israeli regulations are related to exemption of some sources, machines and devices emitting ionizing and non-ionizing radiation, wife a suggestion to extend file above mentioned exemption clause to include some machines and devices and to provide an explicit and detailed list of materials, sources and devices to be exempted. Among these are the following: (authors)

The exemption from the requirement of registration and/or licensing of some sources. machines and devices emitting ionizing and /or on ionizing radiation: a proposed draft for Israeli regulations

International Nuclear Information System (INIS)

Schlesinger, T.; Margaliot, M.

1997-01-01

The licensing and authorization of the import, purchase, distribution, transportation and application of radioactive materials and devices emitting ionizing and/or non-ionizing radiation are carried out in Israel by the Ministries of the Environment and of Health. The legal basis for file authority of these Ministries in radiation protection matters is file P harmacists Regulation- Radioactive Elements and Products Thereof, 1981 (revision 1994) (PRREPT). Licenses are issued by the Chief Radiation Executive (CUE) appointed by the Minister of the Environment and the Minister of Health. The Regulations include a clause which enables the CUE to exempt certain amounts of radioactive materials from file requirements laid down in the PRREPT. The exemption clause is general and does not indicate the types and amounts of radioactive material may be exempted. The proposed draft Israeli regulations are related to exemption of some sources, machines and devices emitting ionizing and non-ionizing radiation, wife a suggestion to extend file above mentioned exemption clause to include some machines and devices and to provide an explicit and detailed list of materials, sources and devices to be exempted. Among these are the following: (authors)

Red-emitting alkaline-earth rare-earth pentaoxometallates powders ...

Indian Academy of Sciences (India)

Moisture-insensitive metal carboxylates that are mostly liquids at room temperature have been first applied to the preparation of strontium europium aluminate (Sr2EuAlO5) powders for red-emitting phosphor under near ultraviolet radiation. Strontium naphthenate, aluminium-2-ethylhexanoate and ...

Cost-Effectiveness Analysis of Stereotactic Body Radiation Therapy Compared With Radiofrequency Ablation for Inoperable Colorectal Liver Metastases

Energy Technology Data Exchange (ETDEWEB)

Kim, Hayeon, E-mail: kimh2@upmc.edu [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania (United States); Gill, Beant; Beriwal, Sushil; Huq, M. Saiful [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania (United States); Roberts, Mark S. [Department of Health Policy and Management, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania (United States); Smith, Kenneth J. [Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (United States)

2016-07-15

Purpose: To conduct a cost-effectiveness analysis to determine whether stereotactic body radiation therapy (SBRT) is a cost-effective therapy compared with radiofrequency ablation (RFA) for patients with unresectable colorectal cancer (CRC) liver metastases. Methods and Materials: A cost-effectiveness analysis was conducted using a Markov model and 1-month cycle over a lifetime horizon. Transition probabilities, quality of life utilities, and costs associated with SBRT and RFA were captured in the model on the basis of a comprehensive literature review and Medicare reimbursements in 2014. Strategies were compared using the incremental cost-effectiveness ratio, with effectiveness measured in quality-adjusted life years (QALYs). To account for model uncertainty, 1-way and probabilistic sensitivity analyses were performed. Strategies were evaluated with a willingness-to-pay threshold of $100,000 per QALY gained. Results: In base case analysis, treatment costs for 3 fractions of SBRT and 1 RFA procedure were $13,000 and $4397, respectively. Median survival was assumed the same for both strategies (25 months). The SBRT costs $8202 more than RFA while gaining 0.05 QALYs, resulting in an incremental cost-effectiveness ratio of $164,660 per QALY gained. In 1-way sensitivity analyses, results were most sensitive to variation of median survival from both treatments. Stereotactic body radiation therapy was economically reasonable if better survival was presumed (>1 month gain) or if used for large tumors (>4 cm). Conclusions: If equal survival is assumed, SBRT is not cost-effective compared with RFA for inoperable colorectal liver metastases. However, if better local control leads to small survival gains with SBRT, this strategy becomes cost-effective. Ideally, these results should be confirmed with prospective comparative data.

Cost-Effectiveness Analysis of Stereotactic Body Radiation Therapy Compared With Radiofrequency Ablation for Inoperable Colorectal Liver Metastases

International Nuclear Information System (INIS)

Kim, Hayeon; Gill, Beant; Beriwal, Sushil; Huq, M. Saiful; Roberts, Mark S.; Smith, Kenneth J.

2016-01-01

Purpose: To conduct a cost-effectiveness analysis to determine whether stereotactic body radiation therapy (SBRT) is a cost-effective therapy compared with radiofrequency ablation (RFA) for patients with unresectable colorectal cancer (CRC) liver metastases. Methods and Materials: A cost-effectiveness analysis was conducted using a Markov model and 1-month cycle over a lifetime horizon. Transition probabilities, quality of life utilities, and costs associated with SBRT and RFA were captured in the model on the basis of a comprehensive literature review and Medicare reimbursements in 2014. Strategies were compared using the incremental cost-effectiveness ratio, with effectiveness measured in quality-adjusted life years (QALYs). To account for model uncertainty, 1-way and probabilistic sensitivity analyses were performed. Strategies were evaluated with a willingness-to-pay threshold of $100,000 per QALY gained. Results: In base case analysis, treatment costs for 3 fractions of SBRT and 1 RFA procedure were $13,000 and $4397, respectively. Median survival was assumed the same for both strategies (25 months). The SBRT costs $8202 more than RFA while gaining 0.05 QALYs, resulting in an incremental cost-effectiveness ratio of $164,660 per QALY gained. In 1-way sensitivity analyses, results were most sensitive to variation of median survival from both treatments. Stereotactic body radiation therapy was economically reasonable if better survival was presumed (>1 month gain) or if used for large tumors (>4 cm). Conclusions: If equal survival is assumed, SBRT is not cost-effective compared with RFA for inoperable colorectal liver metastases. However, if better local control leads to small survival gains with SBRT, this strategy becomes cost-effective. Ideally, these results should be confirmed with prospective comparative data.

Decrease of the exposure to electromagnetic waves emitted by mobile phone relay antennas. Synthesis report on experimentations performed by the COPIC

International Nuclear Information System (INIS)

2013-01-01

A synthetic introduction outlines that simulations reveal a globally low level of public exposure to waves emitted by relay antennas, discusses lessons learned from exposure measurements, indicates that possibilities of treatment exist for the most exposed places, outlines the consequences of a global decrease of exposure on service coverage and quality, outlines a necessary increase of the number of antennas to conceal low exposure and coverage, and that the deployment of 4G should result in an increase of public exposure. Then, the main part of the report presents the fundamental notions related to mobile phone networks and radio waves (electromagnetic radiation, radiofrequency waves and mobile phones, relay antennas and networks, legal thresholds), the implemented method the characteristics of studied areas. It reports the methodology, exposure simulations and exposure measurements, coverage simulations and service quality measurements. It discusses the treatment of the most exposed locations (results from simulations and from measurements). It discusses the results of simulations and experimentations of a decrease of the power of relay antennas, of the simulation of the impact of theoretical 4G additional antennas on exposure. Results obtained in different towns and locations are reported in appendix

Radiofrequency amplifier based on a DC superconducting quantum interference device

International Nuclear Information System (INIS)

Martinis, J.M.; Hilbert, C.; Clarke, J.

1986-01-01

A method is described of amplifying a radiofrequency signal consisting of: disposing a single symmetrically biased dc SQUID and an input coil within a superconducting shield, the dc SQUID having a superconducting ring interrupted by two shunted Josephson junctions, and the input coil being inductively coupled solely to the ring of the single SQUID, establishing a constant magnetic flux threading the SQUID ring, applying the radiofrequency signal to the input coil from outside of the superconducting shield, obtaining an amplified radiofrequency signal solely from across the ring of the single SQUID, transmitting the amplified radiofrequency signal from across the SQUID ring to the outside of the superconducting shield

Effect of Ultra High Frequency Mobile Phone Radiation on Human Health

Science.gov (United States)

Moradi, Mosa; Naghdi, Nasrollah; Hemmati, Hamidreza; Asadi-Samani, Majid; Bahmani, Mahmoud

2016-01-01

Introduction Public and occupational exposure to electromagnetic fields due to the growing trend of electronic devices may cause adverse effects on human health. This paper describes the risk of mutation and sexual trauma and infertility in masculine sexual cell by mobile phone radiations. Methods In this study, we measured the emitted dose from a radiofrequency device, such as switching high voltage at different frequencies using a scintillation detector. The switching high voltage power supply (HVPS) was built for the Single Photon Emission Computed Tomography (SPECT) system. For radiation dosimetry, we used an ALNOR scintillator that can measure gamma radiation. The simulation was performed by MATLAB software, and data from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) were used to verify the simulation. Results We investigated the risks that result from the waves, according to a report by International Commission on Non Ionizing Radiation Protection (ICNIRP), to every organ of the body is defined by the beam and electromagnetic radiation from this electronic device on people. The results showed that the maximum personal dose over a 15-min period working at the mentioned HVPS did not exceed 0.31 μSV/h (with an aluminum shield). So, according to other sources of radiation, continuous working time of the system should not be more than 10 hours. Finally, a characteristic curve for secure working with modules at different frequencies was reported. The RF input signal to the body for maximum penetration depth (δ) and electromagnetic energy absorption rate (SAR) of biological tissue were obtained for each tissue. Conclusion The results of this study and International Commission of Non Ionization Radiation Protection (ICNIRP) reports showed the people who spend more than 50 minutes a day using a cell phone could have early dementia or other thermal damage due to the burning of glucose in the brain. PMID:27382458

COMAR technical information statement: expert reviews on potential health effects of radiofrequency electromagnetic fields and comments on the bioinitiative report.

Science.gov (United States)

2009-10-01

The Committee on Man and Radiation (COMAR) is a technical committee of the Engineering in Medicine and Biology Society (EMBS) of the Institute of Electrical and Electronics Engineers (IEEE). Its primary area of interest is biological effects of non-ionizing electromagnetic radiation, including radiofrequency (RF) energy. The public interest in possible health effects attributed to RF energy, such as emitted by mobile phones, wireless telephone base stations, TV and radio broadcasting facilities, Wi-Fi systems and many other sources, has been accompanied by commentary in the media that varies considerably in reliability and usefulness for their audience. The focus of this COMAR Technical Information Statement is to identify quality sources of scientific information on potential health risks from exposure to RF energy. This Statement provides readers with references to expert reports and other reliable sources of information about this topic, most of which are available on the Internet. This report summarizes the conclusions from several major reports and comments on the markedly different conclusions in the BioInitiative Report (abbreviated BIR below). Since appearing on the Internet in August 2007, the BIR has received much media attention but, more recently, has been criticized by several health organizations (see Section titled "Views of health agencies about BIR"). COMAR concludes that the weight of scientific evidence in the RF bioeffects literature does not support the safety limits recommended by the BioInitiative group. For this reason, COMAR recommends that public health officials continue to base their policies on RF safety limits recommended by established and sanctioned international organizations such as the Institute of Electrical and Electronics Engineers International Committee on Electromagnetic Safety and the International Commission on Non-Ionizing Radiation Protection, which is formally related to the World Health Organization.

New resonant circuits for the ISOLTRAP radiofrequency quadrupole trap

CERN Document Server

SENECAL, Pierre

2015-01-01

This report describes my work during my Summer Student Program. My main project was building and testing a resonance-circuit box for a radio-frequency power supply used with the radio-frequency cooler and buncher.

Reducing radiation exposure in an electrophysiology lab with introduction of newer fluoroscopic technology

Directory of Open Access Journals (Sweden)

Munish Sharma

2017-09-01

Full Text Available The use of fluoroscopic devices exposes patients and operators to harmful effects of ionizing radiation in an electrophysiology (EP lab. We sought to know if the newer fluoroscopic technology (Allura Clarity installed in a hybrid EP helps to reduce prescribed radiation dose. We performed radiation dose analysis of 90 patients who underwent various procedures in the EP lab at a community teaching hospital after the introduction of newer fluoroscopic technology in June of 2016.Watchman device insertion, radiofrequency ablation procedures, permanent pacemaker (PPM/implantable cardioverter defibrillator (ICD placement and battery changes were included in the study to compare radiation exposure during different procedures performed commonly in an EP lab. In all cases of watchman device placement, radiofrequency ablation procedures, PPM/ICD placement and battery changes, there was a statistically significant difference (<0.05 in radiation dose exposure. Significant reduction in radiation exposure during various procedures performed in an EP lab was achieved with aid of newer fluoroscopic technology and better image detection technology.

Radiation in everyday life

International Nuclear Information System (INIS)

Wahlstroem, B.

1994-01-01

The world is radioactive. Radioactive substances and radiation existed on Earth before the first man was born. Radiation reaches man from the cosmos and is also emitted from radioactive substances in the ground, in construction material, in the food and the air. All people are radioactive, too. For instance, all people have got radioactive Radium and Polonium in their skeleton, radioactive Carbon and Potassium in their muscles and radioactive noble gases and Tritium in their lungs. The radiation emitted by the body can be measured by a very sensitive radiation meter called a Whole Body Counter. This paper is a discussion of natural radioactivity and the increased exposure to radiations released by energy production and medical testing

Sources of exposure to radiofrequency and microwave radiations in the UK

CERN Document Server

Allen, S G

1983-01-01

A comprehensive survey is presented of sources of radiofrequency and microwave fields in the United Kingdom that give rise to the exposure of both workers and the general public. The information is presented in the context of the existing guidelines for the restrictions of exposures to such fields and of proposed new guidelines based on restricting the rate of energy absorption averaged over the human body to 0.4 watts per kilogram or, at frequencies below 3 MHz, limiting field strengths to 600 volts per metre. It is concluded that unless account is taken of time averaging relaxations and possible modifying factors relating to energy absorption arising under near field and partial body exposure conditions, there may be difficulties in applying the proposed guidelines to the use of radio frequencies for industrial heating purposes and to some portable and mobile transmitters used for communications.

Radiofrequency for the Treatment of Lumbar Radicular Pain: Impact on Surgical Indications.

Science.gov (United States)

Trinidad, José Manuel; Carnota, Ana Isabel; Failde, Inmaculada; Torres, Luis Miguel

2015-01-01

Study Design. Quasiexperimental study. Objective. To investigate whether radiofrequency treatment can preclude the need for spinal surgery in both the short term and long term. Background. Radiofrequency is commonly used to treat lumbosacral radicular pain. Only few studies have evaluated its effects on surgical indications. Methods. We conducted a quasiexperimental study of 43 patients who had been scheduled for spinal surgery. Radiofrequency was indicated for 25 patients. The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment (pulsed radiofrequency of dorsal root ganglion, 76%; conventional radiofrequency of the medial branch, 12%; combined technique, 12%). The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment. In addition, we also evaluated adverse effects, ODI, NRS. Results. We observed after treatment with radiofrequency 80% of patients rejected spinal surgery in the short term and 76% in the long term. We conclude that radiofrequency is a useful treatment strategy that can achieve very similar outcomes to spinal surgery. Patients also reported a very high level of satisfaction (84% satisfied/very satisfied). We also found that optimization of the electrical parameters of the radiofrequency improved the outcome of this technique.

Radiofrequency for the Treatment of Lumbar Radicular Pain: Impact on Surgical Indications

Directory of Open Access Journals (Sweden)

José Manuel Trinidad

2015-01-01

Full Text Available Study Design. Quasiexperimental study. Objective. To investigate whether radiofrequency treatment can preclude the need for spinal surgery in both the short term and long term. Background. Radiofrequency is commonly used to treat lumbosacral radicular pain. Only few studies have evaluated its effects on surgical indications. Methods. We conducted a quasiexperimental study of 43 patients who had been scheduled for spinal surgery. Radiofrequency was indicated for 25 patients. The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment (pulsed radiofrequency of dorsal root ganglion, 76%; conventional radiofrequency of the medial branch, 12%; combined technique, 12%. The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment. In addition, we also evaluated adverse effects, ODI, NRS. Results. We observed after treatment with radiofrequency 80% of patients rejected spinal surgery in the short term and 76% in the long term. We conclude that radiofrequency is a useful treatment strategy that can achieve very similar outcomes to spinal surgery. Patients also reported a very high level of satisfaction (84% satisfied/very satisfied. We also found that optimization of the electrical parameters of the radiofrequency improved the outcome of this technique.

Symplicity multi-electrode radiofrequency renal denervation system feasibility study.

Science.gov (United States)

Whitbourn, Robert; Harding, Scott A; Walton, Antony

2015-05-01

The aim of this study was to test the safety and performance of the Symplicity™ multi-electrode radio-frequency renal denervation system which was designed to reduce procedure time during renal denervation. The multi-electrode radiofrequency renal denervation system feasibility study is a prospective, non-randomised, open label, feasibility study that enrolled 50 subjects with hypertension. The study utilises a new renal denervation catheter which contains an array of four electrodes mounted in a helical configuration at 90 degrees from each other to deliver radiofrequency energy simultaneously to all four renal artery quadrants for 60 seconds. The protocol specified one renal denervation treatment towards the distal end of each main renal artery with radiofrequency energy delivered for 60 seconds per treatment. Total treatment time for both renal arteries was two minutes. The 12-month change in office systolic blood pressure (SBP) and 24-hour SBP was -19.2±25.2 mmHg, prenal artery stenosis or hypertensive emergencies occurred. The Symplicity multi-electrode radiofrequency renal denervation system was associated with a significant reduction in SBP at 12 months and minimal complications whilst it also reduced procedure time. NCT01699529.

Emerging indications of endoscopic radiofrequency ablation

Science.gov (United States)

Becq, Aymeric; Camus, Marine; Rahmi, Gabriel; de Parades, Vincent; Marteau, Philippe

2015-01-01

Introduction Radiofrequency ablation (RFA) is a well-validated treatment of dysplastic Barrett's esophagus. Other indications of endoscopic RFA are under evaluation. Results Four prospective studies (total 69 patients) have shown that RFA achieved complete remission of early esophageal squamous intra-epithelial neoplasia at a rate of 80%, but with a substantial risk of stricture. In the setting of gastric antral vascular ectasia, two prospective monocenter studies, and a retrospective multicenter study, (total 51 patients), suggest that RFA is efficacious in terms of reducing transfusion dependency. In the setting of chronic hemorrhagic radiation proctopathy, a prospective monocenter study and a retrospective multicenter study (total 56 patients) suggest that RFA is an efficient treatment. A retrospective comparative study (64 patients) suggests that RFA improves stents patency in malignant biliary strictures. Conclusions Endoscopic RFA is an upcoming treatment modality in early esophageal squamous intra-epithelial neoplasia, as well as in gastric, rectal, and biliary diseases. PMID:26279839

Impact of electromagnetic radiation emitted by monitors on changes in the cellular membrane structure and protective antioxidant effect of vitamin A - In vitro study.

Science.gov (United States)

Lewicka, Małgorzata; Henrykowska, Gabriela; Zawadzka, Magdalena; Rutkowski, Maciej; Pacholski, Krzysztof; Buczyński, Andrzej

2017-07-14

The increasing number of devices emitting electromagnetic radiation (EMR) in people's everyday life attracted the attention of researchers because of possible adverse effects of this factor on living organisms. One of the EMR effect may be peroxidation of lipid membranes formed as a result of free radical process. The article presents the results of in vitro studies aimed at identifying changes in malondialdehyde (MDA) concentration - a marker of lipid peroxidation and antioxidant role of vitamin A during the exposure of blood platelets to electromagnetic radiation generated by liquid-crystal-display (LCD) monitors. Electromagnetic radiation emitted by LCD monitors is characterized by parameters: 1 kHz frequency and 220 V/m intensity (15 cm from display screen). The time of exposure was 30 and 60 min. The study was conducted on porcine blood platelets. The samples were divided into 6 groups: unexposed to radiation, unexposed + vitamin A, exposed for 30 min, exposed for 30 min + vitamin A, exposed for 60 min, exposed for 60 min + vitamin A. The MDA concentration in blood platelets increases significantly as compared to control values after 60 min of exposure to EMR. A significant decrease in MDA concentration after the addition of vitamin A was noticed. In the blood samples exposed to EMR for 30 and 60 min the MDA concentration was significantly increased by addition of vitamin A. The results show the possibly negative effect of electromagnetic radiation on the cellular membrane structure manifested by changes in malondialdehyde concentration and indicate a possible protective role of vitamin A in this process. Int J Occup Med Environ Health 2017;30(5):695-703. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

White top-emitting organic light-emitting diodes using one-emissive layer of the DCJTB doped DPVBi layer

Energy Technology Data Exchange (ETDEWEB)

Kim, M.S.; Jeong, C.H.; Lim, J.T. [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyonggi-Do, 440-746 (Korea, Republic of); Yeom, G.Y. [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyonggi-Do, 440-746 (Korea, Republic of); The National Program for Tera-level Devices, Hawolgok-dong, Sungbuk-gu, Seoul, 136-791 (Korea, Republic of)], E-mail: gyyeom@skku.edu

2008-04-01

White top-emitting organic light-emitting diodes (TEOLEDs) composed of one doped emissive layer which emits two-wavelength light though the radiative recombination were fabricated. As the emissive layer, 4,4-bis(2,2-diphenylethen-1-yl)biphenyl (DPVBi) was used as the host material and 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl) -4H-pyran (DCJTB) was added as the dopant material. By optimizing the DCJTB concentration (1.2%) and the thickness of the DPVBi layer (30 nm), the intensity ratio of the two wavelengths could be adjusted for balanced white light emission. By using the device composed of glass/Ag (100 nm)/ITO (90 nm)/2-TNATA (60 nm)/NPB (15 nm)/DPVBi:DCJTB (1.2%, 30 nm)/Alq{sub 3} (20 nm)/Li (1.0 nm)/Al (2.0 nm)/Ag (20 nm)/ITO (63 nm)/SiO{sub 2} (42 nm), the Commission Internationale d'Eclairage (CIE) chromaticity coordinate of (0.32, 0.34) close to the ideal white color CIE coordinate could be obtained at 100 cd/m{sup 2}.

Treatment of Benign Thyroid Nodules: Comparison of Surgery with Radiofrequency Ablation.

Science.gov (United States)

Che, Y; Jin, S; Shi, C; Wang, L; Zhang, X; Li, Y; Baek, J H

2015-07-01

Nodular goiter is one of the most common benign lesions in thyroid nodule. The main treatment of the disease is still the traditional surgical resection, however there are many problems such as general anesthesia, surgical scar, postoperative thyroid or parathyroid function abnormalities, and high nodules recurrence rate in residual gland. The purpose of this study was to compare the efficacy, safety, and cost-effectiveness of 2 treatment methods, surgery and radiofrequency ablation, for the treatment of benign thyroid nodules. From May 2012 to September 2013, 200 patients with nodular goiters who underwent surgery (group A) and 200 patients treated by radiofrequency ablation (group B) were enrolled in this study. Inclusion criteria were the following: 1) cosmetic problem, 2) nodule-related symptoms, 3) hyperfunctioning nodules related to thyrotoxicosis, and 4) refusal of surgery (for group B). An internally cooled radiofrequency ablation system and an 18-ga internally cooled electrode were used. We compared the 2 groups in terms of efficacy, safety, and cost-effectiveness during a 1-year follow-up. After radiofrequency ablation, the nodule volume decreased significantly from 5.4 to 0.4 mL (P = .002) at the 12-month follow-up. The incidence of complications was significantly higher from surgery than from radiofrequency ablation (6.0% versus 1.0%, P = .002). Hypothyroidism was detected in 71.5% of patients after surgery but in none following radiofrequency ablation. The rate of residual nodules (11.9% versus 2.9%, P = .004) and hospitalization days was significantly greater after surgery (6.6 versus 2.1 days, P radiofrequency ablation are both effective treatments of nodular goiter. Compared with surgery, the advantages of radiofrequency ablation include fewer complications, preservation of thyroid function, and fewer hospitalization days. Therefore, radiofrequency ablation should be considered a first-line treatment for benign thyroid nodules. © 2015 by American

Possible cause for altered spatial cognition of prepubescent rats exposed to chronic radiofrequency electromagnetic radiation.

Science.gov (United States)

Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Karun, Kalesh M; Nayak, Satheesha B; Bhat, P Gopalakrishna

2015-10-01

The effects of chronic and repeated radiofrequency electromagnetic radiation (RFEMR) exposure on spatial cognition and hippocampal architecture were investigated in prepubescent rats. Four weeks old male Wistar rats were exposed to RF-EMR (900 MHz; SAR-1.15 W/kg with peak power density of 146.60 μW/cm(2)) for 1 h/day, for 28 days. Followed by this, spatial cognition was evaluated by Morris water maze test. To evaluate the hippocampal morphology; H&E staining, cresyl violet staining, and Golgi-Cox staining were performed on hippocampal sections. CA3 pyramidal neuron morphology and surviving neuron count (in CA3 region) were studied using H&E and cresyl violet stained sections. Dendritic arborization pattern of CA3 pyramidal neuron was investigated by concentric circle method. Progressive learning abilities were found to be decreased in RF-EMR exposed rats. Memory retention test performed 24 h after the last training revealed minor spatial memory deficit in RF-EMR exposed group. However, RF-EMR exposed rats exhibited poor spatial memory retention when tested 48 h after the final trial. Hirano bodies and Granulovacuolar bodies were absent in the CA3 pyramidal neurons of different groups studied. Nevertheless, RF-EMR exposure affected the viable cell count in dorsal hippocampal CA3 region. RF-EMR exposure influenced dendritic arborization pattern of both apical and basal dendritic trees in RF-EMR exposed rats. Structural changes found in the hippocampus of RF-EMR exposed rats could be one of the possible reasons for altered cognition.

Radiations from GSM Base Stations and its Biological Effects

African Journals Online (AJOL)

Michael Horsfall

All rights reserved ... radiofrequency radiations on albino mice placed in exposure cages and ... information in Nigeria on the possible effects of the .... The slides were left to dry on the hot plate ... potential health effect of the RF radiations. It is also a pointer to the need for .... The telecommunication industry is an essential.

Radio-Frequency Emissions from Streamer Collisions: Implications for High-Energy Processes.

Science.gov (United States)

Luque, A.

2017-12-01

The production of energetic particles in a discharge corona is possibly linked to the collision of streamers of opposite polarities [Cooray et al. (2009), Kochkin et al. (2012), Østgaard et al. (2016)]. There is also experimental evidence linking it to radio-frequency emissions in the UHF frequency range (300 MHz-3 GHz) [Montanyà et al. (2015), Petersen and Beasley (2014)]. Here we investigate these two links by modeling the radio-frequency emissions emanating from an encounter between two counter-propagating streamers. Our numerical model combines self-consistently a conservative, high-order Finite-Volume scheme for electron transport with a Finite-Difference Time-Domain (FDTD) method for electromagnetic propagation. We also include the most relevant reactions for streamer propagation: impact ionization, dissociative attachment and photo-ionization. Our implementation benefits from massive parallelization by running on a General-Purpose Graphical Processing Unit (GPGPU). With this code we found that streamer encounters emit electromagnetic waves predominantly in the UHF range, supporting the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges. References Cooray, V., et al., J. Atm. Sol.-Terr. Phys., 71, 1890, doi:10.1016/j.jastp.2009.07.010 (2009). Kochkin, P. O., et al., J. Phys. D, 45, 425202, doi: 10.1088/0022-3727/45/42/425202 (2012). Montanyà, J., et al., J. Atm. Sol.-Terr. Phys., 136, 94, doi:10.1016/j.jastp.2015.06.009, (2015). Østgaard, N., et al., J. Geophys. Res. (Atmos.), 121, 2939, doi:10.1002/2015JD024394 (2016). Petersen, D., and W. Beasley, Atmospheric Research, 135, 314, doi:10.1016/j.atmosres.2013.02.006 (2014).

Heat Sink Effect on Tumor Ablation Characteristics as Observed in Monopolar Radiofrequency, Bipolar Radiofrequency, and Microwave, Using Ex Vivo Calf Liver Model

Science.gov (United States)

Pillai, Krishna; Akhter, Javid; Chua, Terence C.; Shehata, Mena; Alzahrani, Nayef; Al-Alem, Issan; Morris, David L.

2015-01-01

Abstract Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices. With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored. With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres. Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected. Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5. MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. PMID:25738477

Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

Energy Technology Data Exchange (ETDEWEB)

Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

1995-09-01

This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC.

Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

International Nuclear Information System (INIS)

Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E.

1995-09-01

This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC

Applications for radio-frequency identification technology in the perioperative setting.

Science.gov (United States)

Zhao, Tiyu; Zhang, Xiaoxiang; Zeng, Lili; Xia, Shuyan; Hinton, Antentor Othrell; Li, Xiuyun

2014-06-01

We implemented a two-year project to develop a security-gated management system for the perioperative setting using radio-frequency identification (RFID) technology to enhance the management efficiency of the OR. We installed RFID readers beside the entrances to the OR and changing areas to receive and process signals from the RFID tags that we sewed into surgical scrub attire and shoes. The system also required integrating automatic access control panels, computerized lockers, light-emitting diode (LED) information screens, wireless networks, and an information system. By doing this, we are able to control the flow of personnel and materials more effectively, reduce OR costs, optimize the registration and attire-changing process for personnel, and improve management efficiency. We also anticipate this system will improve patient safety by reducing the risk of surgical site infection. Application of security-gated management systems is an important and effective way to help ensure a clean, convenient, and safe management process to manage costs in the perioperative area and promote patient safety. Copyright © 2014 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Occupational exposure to radiofrequency fields in antenna towers

International Nuclear Information System (INIS)

Alanko, T.; Hietanen, M.

2007-01-01

Exposure of workers to radiofrequency fields was assessed in two medium-sized antenna towers. Towers had transmitting antennas from different networks, e.g. mobile phone networks, radio and digital TV sub-stations and amateur radio. The levels of radiofrequency fields were measured close to the ladders of the towers. All measured values were below ICNIRP occupational reference levels. (authors)

Percutaneous Radiofrequency Ablation for Treatment of Recurrent Retroperitoneal Liposarcoma

International Nuclear Information System (INIS)

Keil, Sebastian; Bruners, Philipp; Brehmer, Bernhard; Mahnken, Andreas Horst

2008-01-01

Percutaneous CT-guided radiofrequency ablation (RFA) is becoming more and more established in the treatment of various neoplasms, including retroperitoneal tumors of the kidneys and the adrenal glands. We report the case of RFA in a patient suffering from the third relapse of a retroperitoneal liposarcoma in the left psoas muscle. After repeated surgical resection and supportive radiation therapy of a primary retroperitoneal liposarcoma and two surgically treated recurrences, including replacement of the ureter by a fraction of the ileum, there was no option for further surgery. Thus, we considered RFA as the most suitable treatment option. Monopolar RFA was performed in a single session with a 2-cm umbrella-shaped LeVeen probe. During a 27-month follow-up period the patient remained free of tumor.

Recent developments in white light emitting diodes

Science.gov (United States)

Lohe, P. P.; Nandanwar, D. V.; Belsare, P. D.; Moharil, S. V.

2018-05-01

because they can emit visible light strongly under blue light irradiation. These are chemically, thermally and mechanically stable materials with high efficiency to down convert blue radiation into green and red. Efficient white light can be generated by coating these phosphors on blue LED.CRI of white emitting LED lamp can be improved significantly if green and red emitting phosphors are coated on efficient blue emitting LED chips. In this approach CRI will be maintained if appropriate combination of red, green along with blue emission is used. This article reviews some recent developments in phosphors for white light emitting diodes.

Preliminary results on soil-emitted gamma radiation and its relation with the local atmospheric electric field at Amieira (Portugal)

International Nuclear Information System (INIS)

Lopes, F; Barbosa, S M; Silva, H G; Bárias, S

2015-01-01

The atmospheric electric field near the Earth's surface is dominated by atmospheric pollutants and natural radioactivity, with the latter directly linked to radon ( 222 Rn) gas. For a better comprehension on the temporal variability of both the atmospheric electric field and the radon concentration and its relation with local atmospheric variables, simultaneous measurements of soil-emitted gamma radiation and potential gradient (defined from the vertical component of the atmospheric electric field) were taken every minute, along with local meteorological parameters (e.g., temperature, atmospheric pressure, relative humidity and daily solar radiation). The study region is Amieira, part of the Alqueva lake in Alentejo Portugal, where an interdisciplinary meteorological campaign, ALEX2014, took place from June to August 2014. Soil gamma radiation is more sensitive to small concentrations of radon as compared with alpha particles measurements, for that reason it is more suited for sites with low radon levels, as expected in this case. Preliminary results are presented here: statistical and spectral analysis show that i) the potential gradient has a stronger daily cycle as compared with the gamma radiation, ii) most of the energy of the gamma signal is concentrated in the low frequencies (close to 0), contrary to the potential gradient that has most of the energy in frequency 1 (daily cycle) and iii) a short-term relation between gamma radiation and the potential gradient has not been found. Future work and plans are also discussed. (paper)

Cherenkov radiation; La radiation Cerenkov

Energy Technology Data Exchange (ETDEWEB)

Hubert, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

Radiofrequency ablation of liver tumors (II): clinical application and outcomes.

Science.gov (United States)

Vanagas, Tomas; Gulbinas, Antanas; Pundzius, Juozas; Barauskas, Giedrius

2010-01-01

Radiofrequency ablation is one of the alternatives in the management of liver tumors, especially in patients who are not candidates for surgery. The aim of this article is to review applicability of radiofrequency ablation achieving complete tumor destruction, utility of imaging techniques for patients' follow-up, indications for local ablative procedures, procedure-associated morbidity and mortality, and long-term results in patients with different tumors. The success of local thermal ablation consists in creating adequate volumes of tissue destruction with adequate "clear margin," depending on improved delivery of radiofrequency energy and modulated tissue biophysiology. Different volumes of coagulation necrosis are achieved applying different types of electrodes, pulsing energy sources, utilizing sophisticated ablation schemes. Some additional methods are used to increase the overall deposition of energy through alterations in tissue electrical conductivity, to improve heat retention within the tissue, and to modulate tolerance of tumor tissue to hyperthermia. Contrast-enhanced computed tomography, magnetic resonance imaging, ultrasound or positron emission tomography are applied to control the effectiveness of radiofrequency ablation. The long-term results of radiofrequency ablation are controversial.

77 FR 43535 - Grantee Codes for Certified Radiofrequency Equipment

Science.gov (United States)

2012-07-25

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 2 [FCC 12-60] Grantee Codes for Certified Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: This document... authorization program for radiofrequency (RF) devices under part 2 of its rules. This program is one of the...

Robot-assisted radiofrequency ablation of primary and secondary liver tumours: early experience

International Nuclear Information System (INIS)

Abdullah, Basri Johan Jeet; Yeong, Chai Hong; Goh, Khean Lee; Yoong, Boon Koon; Ho, Gwo Fuang; Yim, Carolyn Chue Wai; Kulkarni, Anjali

2014-01-01

Computed tomography (CT)-compatible robots, both commercial and research-based, have been developed with the intention of increasing the accuracy of needle placement and potentially improving the outcomes of therapies in addition to reducing clinical staff and patient exposure to radiation during CT fluoroscopy. In the case of highly inaccessible lesions that require multiple plane angulations, robotically assisted needles may improve biopsy access and targeted drug delivery therapy by avoidance of the straight line path of normal linear needles. We report our preliminary experience of performing radiofrequency ablation of the liver using a robotic-assisted CT guidance system on 11 patients (17 lesions). Robotic-assisted planning and needle placement appears to have high accuracy, is technically easier than the non-robotic-assisted procedure, and involves a significantly lower radiation dose to both patient and support staff. (orig.)

Robot-assisted radiofrequency ablation of primary and secondary liver tumours: early experience

Energy Technology Data Exchange (ETDEWEB)

Abdullah, Basri Johan Jeet [University of Malaya, Department of Biomedical Imaging, Faculty of Medicine, Kuala Lumpur (Malaysia); Yeong, Chai Hong [University of Malaya, University of Malaya Research Imaging Centre, Faculty of Medicine, Kuala Lumpur (Malaysia); Goh, Khean Lee [University of Malaya, Department of Internal Medicine, Faculty of Medicine, Kuala Lumpur (Malaysia); Yoong, Boon Koon [University of Malaya, Department of Surgery, Faculty of Medicine, Kuala Lumpur (Malaysia); Ho, Gwo Fuang [University of Malaya, Department of Oncology, Faculty of Medicine, Kuala Lumpur (Malaysia); Yim, Carolyn Chue Wai [University of Malaya, Department of Anesthesia, Faculty of Medicine, Kuala Lumpur (Malaysia); Kulkarni, Anjali [Perfint Healthcare Corporation, Florence, OR (United States)

2014-01-15

Computed tomography (CT)-compatible robots, both commercial and research-based, have been developed with the intention of increasing the accuracy of needle placement and potentially improving the outcomes of therapies in addition to reducing clinical staff and patient exposure to radiation during CT fluoroscopy. In the case of highly inaccessible lesions that require multiple plane angulations, robotically assisted needles may improve biopsy access and targeted drug delivery therapy by avoidance of the straight line path of normal linear needles. We report our preliminary experience of performing radiofrequency ablation of the liver using a robotic-assisted CT guidance system on 11 patients (17 lesions). Robotic-assisted planning and needle placement appears to have high accuracy, is technically easier than the non-robotic-assisted procedure, and involves a significantly lower radiation dose to both patient and support staff. (orig.)

Clinical application and developmental trend of radiofrequency ablation technology

International Nuclear Information System (INIS)

Chen Dongfeng

2009-01-01

For recent two decades, radiofrequency ablation technology has made great progress in the field of the treatment for neoplasm. At the very beginning, radiofrequency ablation was adopted in treating the hepatic carcinoma, and since then it has been gradually practiced in treating malignancies of lung, bone, kidney, breast, prostate and other solid tumors. Statistical report of the year 2008 has indicated that in the aspect of similar therapeutic measures radiofrequency ablation therapy for tumors holds a 9% market share. Moreover, in the coming years the clinical use of this kind of therapy for tumors will be steadily increasing by 13% every year. (authors)

Direct measurement of the lethal isotherm for radiofrequency ablation of myocardial tissue.

Science.gov (United States)

Wood, Mark; Goldberg, Scott; Lau, Melissa; Goel, Aneesh; Alexander, Daniel; Han, Frederick; Feinstein, Shawn

2011-06-01

The lethal isotherm for radiofrequency catheter ablation of cardiac myocardium is widely accepted to be 50°C, but this has not been directly measured. The purpose of this study was to directly measure the tissue temperature at the edge of radiofrequency lesions in real time using infrared thermal imaging. Fifteen radiofrequency lesions of 6 to 240 seconds in duration were applied to the left ventricular surface of isolated perfused pig hearts. At the end of radiofrequency delivery, a thermal image of the tissue surface was acquired with an infrared camera. The lesion was then stained and an optical image of the lesion was obtained. The thermal and optical images were electronically merged to allow determination of the tissue temperature at the edge of the lesion at the end of radiofrequency delivery. By adjusting the temperature overlay display to conform with the edge of the radiofrequency lesion, the lethal isotherm was measured to be 60.6°C (interquartile ranges, 59.7° to 62.4°C; range, 58.1° to 64.2°C). The areas encompassed by the lesion border in the optical image and the lethal isotherm in the thermal image were statistically similar and highly correlated (Spearman ρ=0.99, Pradiofrequency delivery or to lesion size (both P>0.64). The areas circumscribed by 50°C isotherms were significantly larger than the areas of the lesions on optical imaging (P=0.002). By direct measurement, the lethal isotherm for cardiac myocardium is near 61°C for radiofrequency energy deliveries radiofrequency ablation is important to clinical practice as well as mathematical modeling of radiofrequency lesions.

Radiofrequency ablation of osteoid osteomas: five years experience.

Science.gov (United States)

Papathanassiou, Zafiria G; Petsas, Theodore; Papachristou, Dionysios; Megas, Panagiotis

2011-12-01

The purpose of this study is to retrospectively evaluate the efficacy of radiofrequency ablation as a curative treatment method for benign bone tumours. Twenty-nine osteoid osteomas were treated with radiofrequency ablation. Primary success rate was 89.6% and total secondary success rate was 93.1%. Mean clinical follow-up period was 26.7 months (range: 6-63 months). Statistical analysis of 25 cases of osteoid osteomas with CT follow-up revealed that post-treatment re-ossification does not correlate with clinical outcome (p = 0.14) but is strongly correlated with long-term (> or = 12 months) CT follow-up (p = 0.014). Percutaneous radiofrequency ablation was found to be an effective and safe treatment for osteoid osteomas. CT findings cannot solely differentiate between treatment successes and failures.

Developing and validating of predictive model for radiofrequency radiation emission within the vicinity of fm stations in Ghana

International Nuclear Information System (INIS)

Ahenkora-Duodu, Kingsley

2016-07-01

The rapid growing number of FM stations with their corresponding antennas have led to an increase in the concern of the potential health risks that may arise as a result of exposure to RF radiations. The main objective of this research was to develop and validate a predictive model with real time measured data for FM antennas in Ghana. Theoretical and experimental assessment of radiofrequency emission due to FM antennas has been analysed. The maximum and minimum electric field spatial average recorded was 7.17E-01 ± 6.97E-01V/m at Kasapa FM and 6.39E-02 ± 5.39E-02V/m at Asempa FM respectively. At a transmission frequency range of 88 -108 MHz, the average power density of the real time measured data ranged between 3.92E-05W/m"2 and 1.37E-03W/m"2 whiles that of the FM model varied from 9.72E-03W/m"2 to 5.35E-01W/m"2 respectively. Results obtained showed a variation between measured power density levels and the FM model. The FM model overestimates the power density levels as compared to that of the measured data. The impact predictions were based on the maximum values estimated by the FM model, hence these results validates the credibility of the impact analysis for the FM stations. The general public exposure quotient ranged between 9.00E-03 and 2.68E-01 whilst that of the occupational exposure quotient varied from 9.72E-04 to 5.35E-02. The results obtained were found to be in compliance with the International Commission on Non-Ionizing Radiation Protection (ICNIRP) RF exposure limit. (au)

Interactions between radiofrequency signals and living organisms

International Nuclear Information System (INIS)

Boudin, F.; Hours, M.; Lacronique, J.F.; Conil, E.; Hadjem, A.; El Habachi, A.; Wiart, K.; Mann, S.; Kundi, M.; Marc-Vergnes, J.P.; Roosli, M.; Mohler, E.; Frei, P.; Davis, Ch.C.; Balzano, Q.; Ait-Aissa, S.; Billaudel, B.; Poulletier De Gannes, F.; Hurtier, A.; Haro, E.; Taxile, M.; Veyret, B.; Lagroye, I.; Ait-Aissa, S.; Poulletier De Gannes, F.; Athane, A.; Veyret, B.; Lagroye, I.; Yardin, C.; Perrin, A.; Freire, M.; Bachelet, Ch.; Collin, A.; Pla, S.; Debouzy, J.C.; Leveque, Ph.; Van Nierop, L.E.; Huss, A.; Roosli, M.; Egger, M.; Calvez, M.; Salomon, D.

2010-01-01

This dossier is composed of 13 articles dealing with the interactions between radio-frequencies and living organisms. It is an overview of various scientific approaches to the field and is of interest for all citizens as the use of mobile phones is widely spread. In the first article it is shown how a model has been built to assess the distribution of the whole body exposure of the population. The second article reviews the state of the art in personal exposure measurements at radio-frequencies. The third article shows that the knowledge of the mechanism of action by which exposure increases the risk of health hazards is necessary. The fourth article shows that individual neuro-psychic factors take a prominent but maybe not unique, part in electromagnetic hypersensitivity. The fifth article shows that no evidence was found to link health disturbances of electromagnetic hypersensitive individuals with radiofrequency exposure. The sixth article shows that the wireless phone is not an athermal hazard to the brain. The seventh article shows that the in utero and post-natal exposure to Wi-Fi does not damage the brains of young rats. The eighth article concludes that recent studies provide no convincing proof of deleterious effects of radiofrequency exposure on the integrity of the blood-brain barrier for specific absorption rates up to 6 W/kg. The ninth article shows that no co-genotoxic effect of radiofrequency was found at levels of exposure that did not induce heating. The tenth article confirms that industry-sponsored studies were least likely to report results suggesting effects. The last article shows that general practitioners are increasingly questioned by their patients about the issue of electromagnetic waves. (A.C.)

CT-guided radiofrequency ablation of osteoid osteoma using a novel battery-powered drill

Energy Technology Data Exchange (ETDEWEB)

Schnapauff, Dirk; Streitparth, Florian; Wieners, Gero; Collettini, Federico; Hamm, Bernd; Gebauer, Bernhard [Charite Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Joehrens, Korinna [Charite Universitaetsmedizin Berlin, Department of Pathology, Berlin (Germany)

2015-05-01

To evaluate the use of a novel battery-powered drill, enabling specimen requirement while drilling, in radiofrequency ablation of osteoid osteoma as an alternative to conventional orthopedic drills. Between 2009 and 2013, altogether 33 patients underwent CT-guided radiofrequency ablation of an osteoid osteoma at our institution. To access the nidus of the clinically and radiologically suspected osteoid osteoma, a channel was drilled using the OnControl Bone Marrow Biopsy System (OBM, Arrow OnControl, Teleflex, Shavano Park, TX, USA) and a biopsy was taken. Procedure time (i.e., drilling including local anesthesia), amount of scans (i.e., single-shot fluoroscopy), radiation exposure, and the results of biopsy were investigated and compared retrospectively to a classical approach using either a manual bone biopsy system or a conventional orthopedic drill (n = 10) after ethical review board approval. Drilling the tract into the nidus was performed without problems in 22 of the 23 OBM cases. Median procedure time was 7 min compared to 13 min using the classical approach (p < 0.001). Median amount CT scans, performed to control correct positioning of the drill was comparable with 26 compared to 24.5 (p = NS) scans. Histologically, the diagnosis of osteoid osteomas could be determined in all 17 cases where a biopsy was taken. Radiofrequency ablation could be performed without problems in any case. The use of the battery-powered drill was feasible and facilitated the access to the osteoid osteoma's nidus offering the possibility to extract a specimen in the same step. (orig.)

Reconfigurable radio-frequency arbitrary waveforms synthesized in a silicon photonic chip.

Science.gov (United States)

Wang, Jian; Shen, Hao; Fan, Li; Wu, Rui; Niu, Ben; Varghese, Leo T; Xuan, Yi; Leaird, Daniel E; Wang, Xi; Gan, Fuwan; Weiner, Andrew M; Qi, Minghao

2015-01-12

Photonic methods of radio-frequency waveform generation and processing can provide performance advantages and flexibility over electronic methods due to the ultrawide bandwidth offered by the optical carriers. However, bulk optics implementations suffer from the lack of integration and slow reconfiguration speed. Here we propose an architecture of integrated photonic radio-frequency generation and processing and implement it on a silicon chip fabricated in a semiconductor manufacturing foundry. Our device can generate programmable radio-frequency bursts or continuous waveforms with only the light source, electrical drives/controls and detectors being off-chip. It modulates an individual pulse in a radio-frequency burst within 4 ns, achieving a reconfiguration speed three orders of magnitude faster than thermal tuning. The on-chip optical delay elements offer an integrated approach to accurately manipulating individual radio-frequency waveform features without constraints set by the speed and timing jitter of electronics, and should find applications ranging from high-speed wireless to defence electronics.

Self-powered radiation detector

International Nuclear Information System (INIS)

Playfoot, K.C.; Bauer, R.F.; Goldstein, N.P.

1980-01-01

This invention relates to a self powered radiation detector requiring no excitation potential to generate a signal indicating a radiation flux. Such detectors comprise two electrically insulated electrodes, at a distance from each other. These electrodes are made of conducting materials having a different response for neutron and/or gamma ray radiation flux levels, as in nuclear power stations. This elongated detector generates an electric signal in terms of an incident flux of radiations cooperating with coaxial conductors insulated from each other and with different radiation reaction characteristics. The conductor with the greatest reaction to the radiations forms the central emitting electrode and the conductor with the least reaction to the radiations forms a tubular coaxial collecting electrode. The rhodium or cobalt tubular emitting electrode contains a ductile central conducting cable placed along the longitudinal axis of the detector. The latter is in high nickel steel with a low reaction to radiation [fr

Fast beam radiofrequency spectroscopy

International Nuclear Information System (INIS)

Pipkin, F.M.

1983-01-01

The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

Enhanced Radiofrequency Ablation With Magnetically Directed Metallic Nanoparticles.

Science.gov (United States)

Nguyen, Duy T; Tzou, Wendy S; Zheng, Lijun; Barham, Waseem; Schuller, Joseph L; Shillinglaw, Benjamin; Quaife, Robert A; Sauer, William H

2016-05-01

Remote heating of metal located near a radiofrequency ablation source has been previously demonstrated. Therefore, ablation of cardiac tissue treated with metallic nanoparticles may improve local radiofrequency heating and lead to larger ablation lesions. We sought to evaluate the effect of magnetic nanoparticles on tissue sensitivity to radiofrequency energy. Ablation was performed using an ablation catheter positioned with 10 g of force over prepared ex vivo specimens. Tissue temperatures were measured and lesion volumes were acquired. An in vivo porcine thigh model was used to study systemically delivered magnetically guided iron oxide (FeO) nanoparticles during radiofrequency application. Magnetic resonance imaging and histological staining of ablated tissue were subsequently performed as a part of ablation lesion analysis. Ablation of ex vivo myocardial tissue treated with metallic nanoparticles resulted in significantly larger lesions with greater impedance changes and evidence of increased thermal conductivity within the tissue. Magnet-guided localization of FeO nanoparticles within porcine thigh preps was demonstrated by magnetic resonance imaging and iron staining. Irrigated ablation in the regions with greater FeO, after FeO infusion and magnetic guidance, created larger lesions without a greater incidence of steam pops. Metal nanoparticle infiltration resulted in significantly larger ablation lesions with altered electric and thermal conductivity. In vivo magnetic guidance of FeO nanoparticles allowed for facilitated radiofrequency ablation without direct infiltration into the targeted tissue. Further research is needed to assess the clinical applicability of this ablation strategy using metallic nanoparticles for the treatment of cardiac arrhythmias. © 2016 American Heart Association, Inc.

Coherent radiation mechanism for cometary kilometric radiation

International Nuclear Information System (INIS)

Lakhina, G.S.; Buti, B.

1988-01-01

A mechanism involving nonlinear interaction of Alfven solitons and Langmuir waves is proposed to explain the cometary kilometric radiation (CKR) observed in the vicinity of comet Halley. According to this model, the frequency of the radiation emitted depends on the position of the interaction (or emission) region relative to the comet; higher frequencies being emitted when this region is closer to the comet. The CKR source is shown to lie at a distance ranging between 10 to the 5th and 2 x 10 to the 6th km from the comet nucleus. Several observed features of CKR, type D, S, and C emissions, can be explained nicely by this model. 24 references

Polaron self-localization in white-light emitting hybrid perovskites

KAUST Repository

Cortecchia, Daniele

2017-02-03

Two-dimensional (2D) perovskites with the general formula APbX are attracting increasing interest as solution processable, white-light emissive materials. Recent studies have shown that their broadband emission is related to the formation of intra-gap colour centres. Here, we provide an in-depth description of the charge localization sites underlying the generation of such radiative centres and their corresponding decay dynamics, highlighting the formation of small polarons trapped within their lattice distortion field. Using a combination of spectroscopic techniques and first-principles calculations to study the white-light emitting 2D perovskites (EDBE)PbCl and (EDBE)PbBr, we infer the formation of Pb , Pb, and X (where X = Cl or Br) species confined within the inorganic perovskite framework. Due to strong Coulombic interactions, these species retain their original excitonic character and form self-trapped polaron-excitons acting as radiative colour centres. These findings are expected to be relevant for a broad class of white-light emitting perovskites with large polaron relaxation energy.

Auger Emitting Radiopharmaceuticals for Cancer Therapy

Science.gov (United States)

Falzone, Nadia; Cornelissen, Bart; Vallis, Katherine A.

Radionuclides that emit Auger electrons have been of particular interest as therapeutic agents. This is primarily due to the short range in tissue, controlled linear paths and high linear energy transfer of these particles. Taking into consideration that ionizations are clustered within several cubic nanometers around the point of decay the possibility of incorporating an Auger emitter in close proximity to the cancer cell DNA has immense therapeutic potential thus making nuclear targeted Auger-electron emitters ideal for precise targeting of cancer cells. Furthermore, many Auger-electron emitters also emit γ-radiation, this property makes Auger emitting radionuclides a very attractive option as therapeutic and diagnostic agents in the molecular imaging and management of tumors. The first requirement for the delivery of Auger emitting nuclides is the definition of suitable tumor-selective delivery vehicles to avoid normal tissue toxicity. One of the main challenges of targeted radionuclide therapy remains in matching the physical and chemical characteristics of the radionuclide and targeting moiety with the clinical character of the tumor. Molecules and molecular targets that have been used in the past can be classified according to the carrier molecule used to deliver the Auger-electron-emitting radionuclide. These include (1) antibodies, (2) peptides, (3) small molecules, (4) oligonucleotides and peptide nucleic acids (PNAs), (5) proteins, and (6) nanoparticles. The efficacy of targeted radionuclide therapy depends greatly on the ability to increase intranuclear incorporation of the radiopharmaceutical without compromising toxicity. Several strategies to achieve this goal have been proposed in literature. The possibility of transferring tumor therapy based on the emission of Auger electrons from experimental models to patients has vast therapeutic potential, and remains a field of intense research.

Percutaneous radiofrequency treatment for refractory anteromedial pain of osteoarthritic knees.

Science.gov (United States)

Ikeuchi, Masahiko; Ushida, Takahiro; Izumi, Masashi; Tani, Toshikazu

2011-04-01

Although severe knee osteoarthritis with refractory pain is commonly treated surgically, this is often not an option for patients with poor health status or unwillingness to undergo major surgery. We examined the efficacy of radiofrequency application to sensory nerves as a novel alternative treatment for refractory knee pain. This study was an open-label, nonrandomized, and controlled study. Patients complaining of refractory anteromedial knee pain associated with radiological osteoarthritis (moderate or severe) were included. They were assigned to one of two groups: those receiving radiofrequency thermocoagulation (N = 18) or those receiving nerve block (N = 17), depending on the time period that they were referred to the clinic. Radiofrequency current or local anesthetics was applied to the medial retinacular nerve and the infrapatellar branch of the saphenous nerve. Western Ontario McMaster Universities osteoarthritis index score, pain visual analog scale (VAS), and patient's global assessment were assessed with a minimum follow-up of 6 months.   Radiofrequency treatment significantly decreased knee pain as measured by VAS for 12 weeks compared with the control group. In terms of responders, more patients in the RF group responded to the treatment than in the control group. The differences were statistically significant at 4 weeks, 8 weeks, and 12 weeks in pain VAS. Eight patients (44%) treated with radiofrequency rated excellent or good but only three (18%) in the control group rated good, although the difference was not statistically significant. Some patients were able to benefit substantially from radiofrequency treatment. Even if its effective period is limited, radiofrequency application is a promising treatment to alleviate refractory anteromedial knee pain with osteoarthritis. Further experience and technical improvements are needed to establish its role in the management of knee osteoarthritis. Wiley Periodicals, Inc.

Treatment of Refractory Idiopathic Supraorbital Neuralgia Using Percutaneous Pulsed Radiofrequency.

Science.gov (United States)

Luo, Fang; Lu, Jingjing; Ji, Nan

2018-02-26

No ideal therapeutic method currently exists for refractory idiopathic supraorbital neuralgia patients who do not respond to conservative therapy, including medications and nerve blocks. Pulsed radiofrequency is a neuromodulation technique that does not produce sequelae of nerve damage after treatment. However, the efficacy of percutaneous pulsed radiofrequency for the treatment of refractory idiopathic supraorbital neuralgia is still not clear. The purpose of our study was to evaluate the efficacy and safety of pulsed radiofrequency treatment of the supraorbital nerve for refractory supraorbital neuralgia patients. We prospectively investigated the long-term effects of ultrasound-guided percutaneous pulsed radiofrequency in the treatment of 22 refractory idiopathic supraorbital neuralgia patients. A reduction in the verbal pain numeric rating scale score of more than 50% was used as the standard of effectiveness. The effectiveness rates at different time points within 2 years were calculated. After a single pulsed radiofrequency treatment, the effectiveness rate at 1 and 3 months was 77%, and the rates at 6 months, 1 year, and 2 years were 73%, 64%, and 50%, respectively. Except for a small portion of patients (23%) who experienced mild upper eyelid ecchymosis that gradually disappeared after approximately 2 weeks, no obvious complications were observed. In conclusion, the results of our study demonstrate that for patients with refractory idiopathic supraorbital neuralgia, percutaneous pulsed radiofrequency may be an effective and safe treatment choice. © 2018 World Institute of Pain.

Percutaneous radiofrequency treatment of osteoid osteoma using cool-tip electrodes

Energy Technology Data Exchange (ETDEWEB)

Martel, Jose [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Avda. de Budapest s/n, 28922 Alcorcon, Madrid (Spain)]. E-mail: jmartel@fhalcorcon.es; Bueno, Angel [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Avda. de Budapest s/n, 28922 Alcorcon, Madrid (Spain); Ortiz, Eduardo [Departamento de Cirugia ortopedica, Fundacion Hospital Alcorcon, Madrid (Spain)

2005-12-15

Objectives: To report our experience with percutaneous cool-tip radiofrequency ablation of osteoid osteomas and to evaluate clinical outcome. Methods and material: Forty-one patients with clinically and radiologically suspected osteoid osteoma were seen over a 48-month period (27 males and 14 females with a mean age of 18.7 years; range 5-43 years). Thirty-eight patients were treated by computed tomography (CT)-guided percutaneous radiofrequency ablation. The procedure was performed under regional or general anaesthesia. After location of the nidus, a 14G-bone biopsy needle is introduced into the nidus. Sampling is performed with a 17G-bone biopsy needle using a coaxial technique. The radiofrequency needle with a 10 mm active tip (cool-tip) is inserted through the biopsy needle and is connected to the radiofrequency generator for 6-8 min. Results: Primary success was obtained in 37 patients (97%) with a 100% secondary success rate. All patients are currently pain-free. No major complications occurred. Patients could resume unrestricted normal activity within 24 h. Conclusions: Percutaneous radiofrequency ablation of osteoid osteomas is an efficient and safe method that can be considered the procedure of choice for most cases.

Visualizing radiofrequency-skin interaction using multiphoton microscopy in vivo.

Science.gov (United States)

Tsai, Tsung-Hua; Lin, Sung-Jan; Lee, Woan-Ruoh; Wang, Chun-Chin; Hsu, Chih-Ting; Chu, Thomas; Dong, Chen-Yuan

2012-02-01

Redundant skin laxity is a major feature of aging. Recently, radiofrequency has been introduced for nonablative tissue tightening by volumetric heating of the deep dermis. Despite the wide range of application based on this therapy, the effect of this technique on tissue and the subsequent tissue remodeling have not been investigated in detail. Our objective is to evaluate the potential of non-linear optics, including multiphoton autofluorescence and second harmonic generation (SHG) microscopy, as a non-invasive imaging modality for the real-time study of radiofrequency-tissue interaction. Electro-optical synergy device (ELOS) was used as the radiofrequency source in this study. The back skin of nude mouse was irradiated with radiofrequency at different passes. We evaluated the effect on skin immediately and 1 month after treatment with multiphoton microscopy. Corresponding histology was performed for comparison. We found that SHG is negatively correlated to radiofrequency passes, which means that collagen structural disruption happens immediately after thermal damage. After 1 month of collagen remodeling, SHG signals increased above baseline, indicating that collagen regeneration has occurred. Our findings may explain mechanism of nonablative skin tightening and were supported by histological examinations. Our work showed that monitoring the dermal heating status of RF and following up the detailed process of tissue reaction can be imaged and quantified with multiphoton microscopy non-invasively in vivo. Copyright © 2011. Published by Elsevier Ireland Ltd.

Radiation dose electrophysiology procedures

International Nuclear Information System (INIS)

Hernandez-Armas, J.; Rodriguez, A.; Catalan, A.; Hernandez Armas, O.; Luque Japon, L.; Moral, S.; Barroso, L.; Rfuez-Hdez, R.

2006-01-01

The aim of this paper has been to measure and analyse some of the parameters which are directly related with the doses given to patients in two electrophysiology procedures: diagnosis and ablation with radiofrequency. 16 patients were considered in this study. 13 them had an ablation with radiofrequency at the Unit of Electrophysiology at the University Hospital of the Canaries, La Laguna., Tenerife. The results of skin doses, in the ablation cases, were higher than 2 Gy (threshold of some deterministic effects). The average value was 1.1 Gy. The personal doses, measured under the lead apron, for physician and nurses were 4 and 3 micro Sievert. These results emphasised the necessity of radiation protection measures in order to reduce, ad much as possible, the doses to patients. (Author)

Higher curvature self-interaction corrections to Hawking radiation

Science.gov (United States)

Fairoos, C.; Sarkar, Sudipta; Yogendran, K. P.

2017-07-01

The purely thermal nature of Hawking radiation from evaporating black holes leads to the information loss paradox. A possible route to its resolution could be if (enough) correlations are shown to be present in the radiation emitted from evaporating black holes. A reanalysis of Hawking's derivation including the effects of self-interactions in general relativity shows that the emitted radiation does deviate from pure thermality; however no correlations exist between successively emitted Hawking quanta. We extend the calculations to Einstein-Gauss-Bonnet gravity and investigate if higher curvature corrections to the action lead to some new correlations in the Hawking spectra. The effective trajectory of a massless shell is determined by solving the constraint equations and the semiclassical tunneling probability is calculated. As in the case of general relativity, the radiation is no longer thermal and there is no correlation between successive emissions. The absence of any extra correlations in the emitted radiations even in Gauss-Bonnet gravity suggests that the resolution of the paradox is beyond the scope of semiclassical gravity.

Characterization of radiofrequency field emissions from smart meters.

Science.gov (United States)

Tell, Richard A; Kavet, Robert; Mezei, Gabor

2013-01-01

This study presents measurement data that describe radiofrequency emission levels and patterns from smart meters (rated nominally at 1 W) currently deployed in Pacific Gas and Electric Company's service territory in northern California. The smart meters in our investigation could not be set to operate continuously and required a Field Service Unit to induce short periods of emitted fields. To obtain peak field data under both laboratory and ambient conditions, a spectrum analyzer scanned across the 83 transmitting channels between 902 and 928 MHz used by the smart meter on a random frequency-hopping basis. To obtain data describing temporal emission patterns, the analyzer operated in scope mode. Duty cycle was estimated using transmit data acquired by the system operator from over 88,000 m. Instantaneous peak fields at 0.3 m in front of the meters were no more than 15% of the US Federal Communications Commission (FCC) exposure limit for the general public, and 99.9% of the meters operated with a duty cycle of 1.12% or less during the sampling period. In a sample of measurements in six single-detached residences equipped with individual smart meters, no interior measurement of peak field exceeded 1% of the FCC's general public exposure limit.

Effect of radiofrequency on capacitance of low density plasma sheath

International Nuclear Information System (INIS)

Carneiro, L.T.; Cunha Rapozo, C. da

1988-01-01

It is shown that the influence of induced radiofrequency potential (V RF ) modifies the Bohm theory on ion saturation current, measured with Langmuir probes. The effect of radiofrequency potential on diode type plasma sheath resonance is also investigated. (M.C.K.)

An explanation of efficiency droop in InGaN-based light emitting diodes: saturated radiative recombination rate at randomly distributed In-rich active areas

International Nuclear Information System (INIS)

Shim, Jong-In; Kim, Hyun-Sung; Shin, Dong-Soo; Yoo, Han-Youl

2011-01-01

We present a comprehensive model of the dependence of the internal quantum efficiency (IQE) on both the temperature and the carrier density in InGaN-based blue and green light emitting diodes (LEDs). In our model, carriers are dominantly located and recombine both radiatively and nonradiatively inside randomly distributed In-rich areas of the InGaN quantum wells (QWs). In those areas, the carrier density is very high even at a small current density. We propose that the saturated radiative recombination rate is a primary factor determining the IQE droop of InGaN based LEDs. In typical InGaN-based QWs, it is common for the total carrier recombination rate to be smaller than the carrier injection rate even at a small current density. This is mostly attributable to the saturation of the radiative recombination rate. The saturation of the radiative recombination rate increases carrier density in InGaN QWs, enlarges nonradiative carrier losses, and eventually gives rise to the large IQE droop with increasing current. We show how the radiative recombination rate saturates and the radiative recombination rate has influence on the IQE droop in InGaN-based QW LEDs.

Effects of the Effect of Ultra High Frequency Mobile Phone Radiation on Human Health.

Science.gov (United States)

Moradi, Mosa; Naghdi, Nasrollah; Hemmati, Hamidreza; Asadi-Samani, Majid; Bahmani, Mahmoud

2016-05-01

Public and occupational exposure to electromagnetic fields due to the growing trend of electronic devices may cause adverse effects on human health. This paper describes the risk of mutation and sexual trauma and infertility in masculine sexual cell by mobile phone radiations. In this study, we measured the emitted dose from a radiofrequency device, such as switching high voltage at different frequencies using a scintillation detector. The switching high voltage power supply (HVPS) was built for the Single Photon Emission Computed Tomography (SPECT) system. For radiation dosimetry, we used an ALNOR scintillator that can measure gamma radiation. The simulation was performed by MATLAB software, and data from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) were used to verify the simulation. We investigated the risks that result from the waves, according to a report by International Commission on Non Ionizing Radiation Protection (ICNIRP), to every organ of the body is defined by the beam and electromagnetic radiation from this electronic device on people. The results showed that the maximum personal dose over a 15-min period working at the mentioned HVPS did not exceed 0.31 μSV/h (with an aluminum shield). So, according to other sources of radiation, continuous working time of the system should not be more than 10 hours. Finally, a characteristic curve for secure working with modules at different frequencies was reported. The RF input signal to the body for maximum penetration depth (δ) and electromagnetic energy absorption rate (SAR) of biological tissue were obtained for each tissue. The results of this study and International Commission of Non Ionization Radiation Protection (ICNIRP) reports showed the people who spend more than 50 minutes a day using a cell phone could have early dementia or other thermal damage due to the burning of glucose in the brain.

Percutaneous radiofrequency ablation for benign nodules of the thyroid gland

International Nuclear Information System (INIS)

Baek, Jung Hwan; Jeong, Hyun Jo; Kim, Yoon Suk; Kwak, Min Sook; Chang, Sun Hee; Rhim, Hyun Chul

2005-01-01

We wanted to evaluate the efficacy and safety of using ultrasound guided percutaneous radiofrequency ablation for the benign nodules of the thyroid gland. We studied 148 patients with benign thyroid nodules (200 total nodules) that were confirmed histopathologically, and we performed ultrasound guided radiofrequency ablation. The radiofrequency ablation was done 1 to 5 times per one nodule, and follow-up ultrasonography was performed one to nineteen months after the ablation procedures. The physical changes and the decrease of volume of the nodules were evaluated, and the complications related to radiofrequency ablation were observed. The mean initial nodule volume was 0.01-95.61 ml (mean; 6.83 ± SD of 10.63 ml) and the nodule volume after radiofrequency ablation was decreased to 0.00-46.56 ml (mean; 1.83 ± SD of 4.69 ml). The mean volume reduction rate was 73.2%. Reduction of more than 50% was noted in 90% of all cases. For 180 nodules (90%), the decrease was 50% or more, in 20 nodules (10%), the decrease was 49% or less. On gray-scale ultrasonogram obtained after ablation, the echogenicity of the nodules changed to darker, and on the doppler-sonogram, the vascular flow within the nodules disappeared in all cases. Most patients complained pain during or right after the procedure, but the pain was transient and subsided after medication. Two patients developed hoarseness that was improved in 1 week and 2 months, respectively. Sonoguided percutaneous radiofrequency ablation can be one of the treatments for benign nodules of the thyroid gland

Knee cooled radiofrequency vs continuous radiofrequency for genicular neurotomy: preliminary experience - Crio-radiofrequenza vs radiofrequenza continua per neurotomia dei nervi genicolati: esperienza preliminare

Directory of Open Access Journals (Sweden)

Alfonso Papa

2016-09-01

Full Text Available Radiofrequency neurotomy of genicular nerves has been often used as an efficacious treatment option in all patients suffering from chronic osteoarthritis pain to provide long-term pain relief. After providing informed written consent, 80 patients with severe knee chronic osteoarthritis pain had been enrolled; patients had been divided into two groups (Group C, crioneurolysis, vs Group R, traditional radiofrequency, 40 patients for each group. Pain relief in C group was poorer and with shorter time in duration (median NRS reducing from 8 to 5. Radiofrequency can be considered as an effective, minimally invasive treat­ment for these kinds of conditions, and offers the benefit of being a fast procedure with long-term pain relief.

Mechanisms for enlarging lesion size during irrigated tip radiofrequency ablation

DEFF Research Database (Denmark)

Petersen, Helen Høgh; Roman-Gonzalez, Javier; Johnson, Susan B

2004-01-01

INTRODUCTION: Irrigated tip radiofrequency ablation of cardiac arrhythmias was developed to increase the size of the radiofrequency-induced lesion, since cooling of the electrode tip allows use of higher power settings. The purpose of this study was to determine if the increased lesion size during...

Paying attention to radiofrequency ablation therapy for neoplasms

International Nuclear Information System (INIS)

Wang Zhongming; Li Linsun

2010-01-01

Radiofrequency ablation is an effective treatment for malignant tumors. With the development of imaging technique, it has been widely used in treating different kinds of malignant tumors, such as liver cancer, lung cancer, kidney carcinoma, etc. Radiofrequency ablation has a lot of advantages. As a minimally-invasive, safe and effective treatment with less sufferings and fewer complications, this technique has attracted more and more attention of the experts both at home and abroad. (authors)

Radiofrequency for the treatment of skin laxity: mith or truth*

Science.gov (United States)

de Araújo, Angélica Rodrigues; Soares, Viviane Pinheiro Campos; da Silva, Fernanda Souza; Moreira, Tatiane da Silva

2015-01-01

The nonablative radiofrequency is a procedure commonly used for the treatment of skin laxity from an increase in tissue temperature. The goal is to induce thermal damage to thus stimulate neocollagenesis in deep layers of the skin and subcutaneous tissue. However, many of these devices haven't been tested and their parameters are still not accepted by the scientific community. Because of this, it is necessary to review the literature regarding the physiological effects and parameters for application of radiofrequency and methodological quality and level of evidence of studies. A literature search was performed in MEDLINE, PEDro, SciELO, PubMed, LILACS and CAPES and experimental studies in humans, which used radiofrequency devices as treatment for facial or body laxity, were selected. The results showed that the main physiological effect is to stimulate collagen synthesis. There was no homogeneity between studies in relation to most of the parameters used and the methodological quality of studies and level of evidence for using radiofrequency are low. This fact complicates the determination of effective parameters for clinical use of this device in the treatment of skin laxity. The analyzed studies suggest that radiofrequency is effective, however the physiological mechanisms and the required parameters are not clear in the literature. PMID:26560216

Preparation and Characterization of UV Emitting Fluoride Phosphors for Phototherapy Lamps

Science.gov (United States)

Belsare, P. D.; Moharil, S. V.; Joshi, C. P.; Omanwar, S. K.

2011-10-01

The use of ultraviolet radiation for the treatment of various skin diseases is well known for long time. Phototherapy employs ultraviolet-blue radiation to cure skin diseases. The basis of phototherapy is believed to be the direct interaction of light of certain frequencies with tissue to cause a change in immune response. Currently dermatologists use UV lamps having specific emissions in UV region for treating various skin diseases. The treatment of skin diseases using artificial sources of UV radiation is now well established and more than 50 types of skin diseases are treated by phototherapy. This is an effective treatment for many skin disorders, such as psoriasis, vitiligo, ofujis disease, morphea , scleroderma, cutaneous T-cell lymphoma, lupus erythematosus, hyperbilirubinemia commonly known as infant jaundice, acne vulgaris, This paper reports photoluminescence properties of UV emitting fluoride phosphors prepared by wet chemical method. Emission characteristics of these phosphors are found similar to those of commercial UV lamp phosphors with comparable intensities. The usefulness of UV emitting fluoride phosphor is discussed in the paper.

Radiation protection problems with sealed Pu radiation sources

International Nuclear Information System (INIS)

Naumann, M.; Wels, C.

1982-01-01

A brief outline of the production methods and most important properties of Pu-238 and Pu-239 is given, followed by an overview of possibilities for utilizing the different types of radiation emitted, a description of problems involved in the safe handling of Pu radiation sources, and an assessment of the design principles for Pu-containing alpha, photon, neutron and energy sources from the radiation protection point of view. (author)

The biological effects of quadripolar radiofrequency sequential application: a human experimental study.

Science.gov (United States)

Nicoletti, Giovanni; Cornaglia, Antonia Icaro; Faga, Angela; Scevola, Silvia

2014-10-01

An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model. Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening. The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radiofrequency applications were performed on human full-thickness skin and subcutaneous tissue specimens harvested during surgery for body contouring. In the in vivo assessments the applications were performed on two volunteer patients scheduled for body contouring surgery at the end of the study. The assessment methods were: clinical examination and medical photography, temperature measurement with thermal imaging scan, and light microscopy histological examination. The ex vivo assessments allowed for identification of the effective safety range for human application. The in vivo assessments allowed for demonstration of the biological effects of sequential radiofrequency applications. After a course of radiofrequency applications, the collagen fibers underwent an immediate heat-induced rearrangement and were partially denaturated and progressively metabolized by the macrophages. An overall thickening and spatial rearrangement was appreciated both in the collagen and elastic fibers, the latter displaying a juvenile reticular pattern. A late onset in the macrophage activation after sequential radiofrequency applications was appreciated. Our data confirm the effectiveness of sequential radiofrequency applications in obtaining attenuation of the skin wrinkles by an overall skin tightening.

Safety of light emitting diodes in toys.

Science.gov (United States)

Higlett, M P; O'Hagan, J B; Khazova, M

2012-03-01

Light emitting diodes (LEDs) are increasingly being used in toys. An assessment methodology is described for determining the accessible emission limits for the optical radiation from the toys, which takes account of expected use and reasonably foreseeable misuse of toys. Where data are available, it may be possible to assess the toy from the data sheet alone. If this information is not available, a simple measurement protocol is proposed.

Safety of light emitting diodes in toys

International Nuclear Information System (INIS)

Higlett, M P; O'Hagan, J B; Khazova, M

2012-01-01

Light emitting diodes (LEDs) are increasingly being used in toys. An assessment methodology is described for determining the accessible emission limits for the optical radiation from the toys, which takes account of expected use and reasonably foreseeable misuse of toys. Where data are available, it may be possible to assess the toy from the data sheet alone. If this information is not available, a simple measurement protocol is proposed.

One-year results of the use of endovenous radiofrequency ablation utilising an optimised radiofrequency-induced thermotherapy protocol for the treatment of truncal superficial venous reflux.

Science.gov (United States)

Badham, George E; Dos Santos, Scott J; Lloyd, Lucinda Ba; Holdstock, Judy M; Whiteley, Mark S

2018-06-01

Background In previous in vitro and ex vivo studies, we have shown increased thermal spread can be achieved with radiofrequency-induced thermotherapy when using a low power and slower, discontinuous pullback. We aimed to determine the clinical success rate of radiofrequency-induced thermotherapy using this optimised protocol for the treatment of superficial venous reflux in truncal veins. Methods Sixty-three patients were treated with radiofrequency-induced thermotherapy using the optimised protocol and were followed up after one year (mean 16.3 months). Thirty-five patients returned for audit, giving a response rate of 56%. Duplex ultrasonography was employed to check for truncal reflux and compared to initial scans. Results In the 35 patients studied, there were 48 legs, with 64 truncal veins treated by radiofrequency-induced thermotherapy (34 great saphenous, 15 small saphenous and 15 anterior accessory saphenous veins). One year post-treatment, complete closure of all previously refluxing truncal veins was demonstrated on ultrasound, giving a success rate of 100%. Conclusions Using a previously reported optimised, low power/slow pullback radiofrequency-induced thermotherapy protocol, we have shown it is possible to achieve a 100% ablation at one year. This compares favourably with results reported at one year post-procedure using the high power/fast pullback protocols that are currently recommended for this device.

Comparison of the heat shock response induced by conventional heating and two methods of delivery of pulsed radiofrequency energy

International Nuclear Information System (INIS)

Laurence, J.A.; University of Sydney, NSW; McKenzie, D.R.; Veas, L.; French, P.W.

2002-01-01

Full text: In 2001, we published a (hypothetical) mechanism by which radiofrequency (RF) radiation from mobile phones could induce cancer, via the chronic induction of the heat shock response (HSR). This hypothesis provides the focus for our research. Other groups have reported induction of the HSR by RF at apparently non thermal levels. The aim of this study was to determine whether the HSR induced by RF is (a) truly non thermal and (b) quantitatively or qualitatively different from that induced by conventional heating of cells. A rat mast cell line, RBL-2H3, was chosen as the target RBL-2H3 cells were exposed in an air incubator at 41.1 deg C for 45 minutes and 75 minutes, and then returned to a 37 deg C incubator. Sham exposures were performed in the same air incubator at 37 deg C. Cells were exposed for 1 hour in the two pulsed RF exposure systems. The first was a converted 750W microwave oven that emits a short burst of 2.45GHz pulses at the start of each contiguous six minute period. This exposes cells to an average specific energy absorption rate (SAR) of 20W/kg. The second system was a TEM cell, which simulates. GSM pulses - the earner frequency is 0.9GHz pulse modulated at 217Hz. The SAR was approx 0.1W/kg. Both of these exposure systems are housed in incubators maintained at 37 deg C. Sham exposures were performed in the two systems with the same conditions but with no RF radiation present. Cell samples for the conventional heating and microwave exposures were taken 0, 2. 5, 5 and 20 hours after exposure, and expression of heat shock proteins hsp 110, 90, 70, 60 and 56 were determined by Western Blotting and compared between exposures

Report by the work-group on 'safety of medical devices emitting ionizing radiations'. Articulation of radiation protection requirements of the 97/43/Euratom directive and IAEA recommendations with the essential requirements of the 93/42/CEE directive related to medical devices used in external radiotherapy

International Nuclear Information System (INIS)

2010-01-01

As some dysfunctions and events had been reported in 2007 and 2008 in field of radiotherapy, this report aims at clarifying the articulation between the different European regulations concerning medical devices emitting ionizing radiations and radiation protection. The authors report a survey with device manufacturers, and analyze the content of the different regulations and recommendations. Then, the authors recommend and propose a set of actions related to the IAEA requirements and recommendations, to CE marking requirements, and to new radiation protection and safety requirements present in the Euratom directive

Comparison of renal artery, soft tissue, and nerve damage after irrigated versus nonirrigated radiofrequency ablation.

Science.gov (United States)

Sakakura, Kenichi; Ladich, Elena; Fuimaono, Kristine; Grunewald, Debby; O'Fallon, Patrick; Spognardi, Anna-Maria; Markham, Peter; Otsuka, Fumiyuki; Yahagi, Kazuyuki; Shen, Kai; Kolodgie, Frank D; Joner, Michael; Virmani, Renu

2015-01-01

The long-term efficacy of radiofrequency ablation of renal autonomic nerves has been proven in nonrandomized studies. However, long-term safety of the renal artery (RA) is of concern. The aim of our study was to determine if cooling during radiofrequency ablation preserved the RA while allowing equivalent nerve damage. A total of 9 swine (18 RAs) were included, and allocated to irrigated radiofrequency (n=6 RAs, temperature setting: 50°C), conventional radiofrequency (n=6 RAs, nonirrigated, temperature setting: 65°C), and high-temperature radiofrequency (n=6 RAs, nonirrigated, temperature setting: 90°C) groups. RAs were harvested at 10 days, serially sectioned from proximal to distal including perirenal tissues and examined after paraffin embedding, and staining with hematoxylin-eosin and Movat pentachrome. RAs and periarterial tissue including nerves were semiquantitatively assessed and scored. A total of 660 histological sections from 18 RAs were histologically examined by light microscopy. Arterial medial injury was significantly less in the irrigated radiofrequency group (depth of medial injury, circumferential involvement, and thinning) than that in the conventional radiofrequency group (Pradiofrequency group (Pradiofrequency group and conventional radiofrequency group (P=0.36), there was a trend toward less nerve damage in the irrigated compared with conventional. Compared to conventional radiofrequency, circumferential medial damage in highest-temperature nonirrigated radiofrequency group was significantly greater (Pradiofrequency ablation, and there is a trend toward less nerve damage. © 2014 American Heart Association, Inc.

Electromagnetic field sources in radiofrequency

International Nuclear Information System (INIS)

Oliveira, C.; Sebastiao, D.; Ladeira, D.; Antunes, M.; Correia, L.M.

2010-01-01

In the scope of the monIT Project, several measurements were made of electromagnetic fields in Portugal. This paper presents an analysis of the sources operating in the radiofrequency range, resulting from 2429 measurements in 466 locations.

Instrument development for atmospheric radiation measurement (ARM): Status of the Atmospheric Emitted Radiance Interferometer - extended Resolution (AERI-X), the Solar Radiance Transmission Interferometer (SORTI), and the Absolute Solar Transmission Inferometer (ASTI)

Energy Technology Data Exchange (ETDEWEB)

Murcray, F.; Stephen, T.; Kosters, J. [Univ. of Denver, CO (United States)

1996-04-01

This paper describes three instruments currently under developemnt for the Atmospheric Radiation Measurement (ARM) Program at the University of Denver: the AERI-X (Atmospheric Emitted Radiance Interferometer-Extended Resolution) and the SORTI (Solar R adiance Transmission Interferometer), and ASTI (Absolute Solar transmission Interferometer).

Radiofrequency electromagnetic fields emitted from base stations of DECT cordless phones and the risk of glioma and meningioma (Interphone Study Group, Germany)

DEFF Research Database (Denmark)

Schüz, Joachim; Böhler, Eva; Schlehofer, Brigitte

2006-01-01

The objective of this study was to test the hypothesis that exposure to continuous low-level radiofrequency electromagnetic fields (RF EMFs) increases the risk of glioma and meningioma. Participants in a population-based case-control study in Germany on the risk of brain tumors in relation...... to cellular phone use were 747 incident brain tumor cases between the ages of 30 and 69 years and 1494 matched controls. The exposure measure of this analysis was the location of a base station of a DECT (Digital Enhanced Cordless Telecommunications) cordless phone close to the bed, which was used as a proxy...

Cellular responses to 836 MHz and 1,765 GHz CDMA radiations

International Nuclear Information System (INIS)

Park, Woong Yang; Seo, Jeong Sun; Paik, Jung Ki; Lim, Kye Jae; Yoon, Hyun Bo

2002-01-01

The effect of radiofrequency (RF) radiation in the cellular phone communication range (836.5 MHz and 1.765 GHz code division multiple access, CDMA) on tumorigenesis and other health effect was measured using the in vitro cell culture system. To determine whether 836.5 MHz or 1.765 GHz CDMA radiations have any genotoxic effects to induce neoplastic transformation, C3H 10T1/2 cells were exposed to either of the above radiations at a specific absorption rate (SAR) of 35.6W/Kg (836.5 MHz) and 38.2 W/kg(1.765 GHz) or sham- exposed at the same time for 7 days. Cells were maintained in incubators and refed with fresh growth medium every 3 days. At this SAR, radiofrequency radiation did not induce neoplastic transformation in vitro. The extent of alteration in the kinetics of cell proliferation indicated no significant differences between RF-radiation- and sham-exposed cells with respect to MTS assay and 8-OHdG. Under this experimental conditions tested, there is no evidence for the induction of genotoxic indices in human and mouse cells exposed in vitro for 7 days to 836.5 MHz or 1.765 GHz RF radiation at SARs of up to 35.6 or 38.2 W/kg

Thermal hadron production by QCD Hawking radiation

International Nuclear Information System (INIS)

Satz, Helmut

2007-01-01

The QCD counterpart of Hawking radiation from black holes leads to thermal hadron production in high energy collisions, from e + e - annihilation to heavy ion interactions. This hadronic radiation is emitted at a universal temperature T≅(σ/2π) 1/2 , where the string tension σ measures the colour field at the event horizon of confinement. Moreover, the emitted radiation is thermal 'at birth'; since the event horizon prevents all information transfer, no memory has to be destroyed kinetically. (author)

Radiofrequency electromagnetic fields in the Cookridge area of Leeds

International Nuclear Information System (INIS)

Fuller, K.; Gulson, A.D.; Judd, P.M.; Lowe, A.J.; Shaw, J.

2002-01-01

On the 8 and 9 May 2002 representatives of the National Radiological Protection Board (NRPB) performed a radiofrequency electromagnetic field survey in the Cookridge area of Leeds in order to assess exposure to radio signals from transmitters mounted on a water tower/a lattice tower and a radio station tower. Guidelines on limiting exposure to radio signals have been published by NRPB and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are designed to prevent established adverse effects on human health. During this survey, the total exposures due to all radio signals from 30 MHz to 18000 MHz (18 GHz) were measured. This frequency range was chosen as it includes mobile phone base station transmissions, which are at around 900 and 1800 MHz and super high frequency (SHF) transmissions from most of the large microwave dish antennas mounted on the towers. In addition, other major sources of radiofrequency electromagnetic fields in the environment such as broadcast radio and television transmissions are included in this range. Measurements of power density were made at eight locations in the vicinity of the transmitter sites. Comparison of the measurements with the guidelines showed that the total exposure from radio signals measured between 30 MHz and 18 GHz ranged from 0.26 millionths (0.000026%) to 190 millionths (0.019%) of the NRPB investigation level and from 1.6 millionths (0.00016%) to 1400 millionths (0.14%) of the ICNIRP reference level for exposure of the general public. All the measured exposures are therefore many times below guideline levels and are not considered hazardous. (author)

Canada: Living with radiation

International Nuclear Information System (INIS)

1995-01-01

Canadians are exposed daily to a variety of naturally occurring radiation. Heat and light from the sun, are familiar examples. Radium and uranium are naturally occurring materials which have been found to emit radiation and so have been called radioactive. There are also various types of artificially produced forms of radiation that are employed routinely in modern living, such as radio and television waves and microwaves. X-rays, another common type of radiation, are widely used in medicine as are some man-made radioactive substances. These emit radiation just like naturally occurring radioactive materials. Surveys have shown that many people have a poor understanding of the risks associated with the activities of modern living. Exposure to ionizing radiation from radioactive materials is also considered by many persons to have a high risk, This booklet attempts to inform the readers about ionizing radiation, its uses and the risks associated with it, and to put these risks in perspective with the risks of other activities and practices. A range of topics from medical uses of radiation to emergency planning, from biological effects of radiation to nuclear power, each topic is explained to relate radiation to our everyday lives. 44 figs

Canada: Living with radiation

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

Canadians are exposed daily to a variety of naturally occurring radiation. Heat and light from the sun, are familiar examples. Radium and uranium are naturally occurring materials which have been found to emit radiation and so have been called radioactive. There are also various types of artificially produced forms of radiation that are employed routinely in modern living, such as radio and television waves and microwaves. X-rays, another common type of radiation, are widely used in medicine as are some man-made radioactive substances. These emit radiation just like naturally occurring radioactive materials. Surveys have shown that many people have a poor understanding of the risks associated with the activities of modern living. Exposure to ionizing radiation from radioactive materials is also considered by many persons to have a high risk, This booklet attempts to inform the readers about ionizing radiation, its uses and the risks associated with it, and to put these risks in perspective with the risks of other activities and practices. A range of topics from medical uses of radiation to emergency planning, from biological effects of radiation to nuclear power, each topic is explained to relate radiation to our everyday lives. 44 figs.

[Catheter ablation in patients with refractory cardiac arrhythmias with radiofrequency techniques].

Science.gov (United States)

de Paola, A A; Balbão, C E; Silva Netto, O; Mendonça, A; Villacorta, H; Vattimo, A C; Souza, I A; Guiguer Júnior, N; Portugal, O P; Martinez Filho, E E

1993-02-01

evaluate the efficacy of radiofrequency catheter ablation in patients with refractory cardiac arrhythmias. twenty patients with refractory cardiac arrhythmias were undertaken to electrophysiologic studies for diagnosis and radiofrequency catheter ablation of their reentrant arrhythmias. Ten patients were men and 10 women with ages varying from 13 to 76 years (mean = 42.4 years). Nineteen patients had supraventricular tachyarrhythmias: One patient had atrial tachycardia and 1 atrial fibrillation with rapid ventricular rate, 5 patients had reentrant nodal tachycardia, 12 patients had reentrant atrioventricular tachycardia and 1 patient had right ventricular outflow tract tachycardia. the mean time of the procedure was 4.1 hours. The radiofrequency current energy applied was 40-50 V for 30-40 seconds. Ablation was successful in 18/20 (90%) patients; in 15/18 (83%) of successfully treated patients the same study was done for diagnosis and radiofrequency ablation. One patient had femoral arterial occlusion and was treated with no significant sequelae. During a mean follow-up of 4 months no preexcitation or reentrant tachycardia occurred. the results of our experience with radiofrequency catheter ablation of cardiac arrhythmias suggest that this technique can benefit an important number of patients with cardiac arrhythmias.

Radiofrequency ablation of hepatic metastasis: Results of treatment in forty patients

Directory of Open Access Journals (Sweden)

Rath G

2008-01-01

Full Text Available Aim: To evaluate the local control of hepatic metastasis with radiofrequency ablation treatment. Materials and Methods: We did a retrospective analysis in 40 patients treated with radiofrequency ablation for hepatic metastasis. The tumors ablated included up to two metastatic liver lesions, with primaries in breast, gastrointestinal tract, cervix, etc. Radiofrequency ablation was performed under general anesthesia in all cases, using ultrasound guidance. Radionics Cool-Tip RF System was used to deliver the treatment. Results: The median age of patients treated was 49 years. There were 13 female and 27 male patients. The median tumor size ablated was 1.5 cm (0.75-4.0 cm. A total of 52 radiofrequency ablation cycles were delivered. Successful ablation was achieved in all patients with hepatic metastasis less than 3 cm in size. Pain was the most common complication seen (75%. One patients developed skin burns. At 2-year follow-up 7.5% of patients had locally recurrent disease. Conclusions: Radiofrequency ablation is a minimally invasive treatment modality. It can be useful in a select group of patients with solitary liver metastasis of less than 3 cm size.

Stimulated coherent transition radiation

International Nuclear Information System (INIS)

Hung-chi Lihn.

1996-03-01

Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed

Palliative treatment with radiation-emitting metallic stents in unresectable Bismuth type III or IV hilar cholangiocarcinoma.

Science.gov (United States)

Lu, Jian; Guo, Jin-He; Zhu, Hai-Dong; Zhu, Guang-Yu; Wang, Yong; Zhang, Qi; Chen, Li; Wang, Chao; Pan, Tian-Fan; Teng, Gao-Jun

2017-01-01

The emerging data for stenting in combination with brachytherapy in unresectable hilar cholangiocarcinoma are encouraging. The aim of this study was to evaluate the efficacy and safety of radiation-emitting metallic stents (REMS) for unresectable Bismuth type III or IV hilar cholangiocarcinoma. Consecutive patients who underwent percutaneous placement with REMS or uncovered self-expandable metallic stent (SEMS) for unresectable Bismuth type III or IV hilar cholangiocarcinoma between September 2011 and April 2016 were identified into this retrospective study. Data on patient demographics and overall survival, functional success, stent patency and complications were collected at the authors' hospital. A total of 59 patients were included: 33 (55.9%) in the REMS group and 26 (44.1%) in the SEMS group. The median overall survival was 338 days in the REMS group and 141 days in the SEMS group (philar cholangiocarcinoma, and seems to prolong survival as well as patency of stent in these patients.

Acoustic Radiation Force Impulse Elastography for Efficacy Evaluation after Hepatocellular Carcinoma Radiofrequency Ablation: A Comparative Study with Contrast-Enhanced Ultrasound

Directory of Open Access Journals (Sweden)

Xiaohong Xu

2014-01-01

Full Text Available Aim. To explore acoustic radiation force impulse (ARFI elastography in assessing residual tumors of hepatocellular carcinoma (HCC after radiofrequency ablation (RFA. Materials and Methods. There were 83 HCC lesions among 72 patients. All patients were examined with ARFI, contrast enhanced ultrasound (CEUS, and CT or MRI. Tumor brightness on virtual touch tissue imaging (VTI and shear wave velocity (SWV were assessed before and approximately one month after RFA. Results. There were 14 residual tumors after RFA. VTI showed that all the tumors were darker after RFA. VTI was not able to distinguish the ablated lesions and the residual tumors. 13 residual tumor lesions were detected by CEUS. All completely ablated nodules had SWV demonstration of x.xx., while with those residual nodules, 6 tumors had x.xx measurement and 8 tumors had measurable SWV. nine lesions with residual tumors occurred in cirrhosis subjects and 5 lesions with residual tumors occurred in fibrosis subjects; there was no residual tumor in the normal liver subjects. Conclusion. VTI technique cannot demonstrate residual tumor post RFA. While SWV measurement of less than x.xx is likely associated with residual tumors, measurement of less than x.xx cannot exclude residual tumors. Liver cirrhosis is associated with decreased chance of a complete ablation.

Acoustic Radiation Force Impulse Elastography for Efficacy Evaluation after Hepatocellular Carcinoma Radiofrequency Ablation: A Comparative Study with Contrast-Enhanced Ultrasound

Science.gov (United States)

Xu, Xiaohong; Luo, Liangping; Chen, Jiexin; Wang, Jiexin; Zhou, Honglian; Li, Mingyi; Jin, Zhanqiang; Chen, Nianping; Miao, Huilai; Lin, Manzhou; Dai, Wei; Ahuja, Anil T.; Wang, Yi-Xiang J.

2014-01-01

Aim. To explore acoustic radiation force impulse (ARFI) elastography in assessing residual tumors of hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA). Materials and Methods. There were 83 HCC lesions among 72 patients. All patients were examined with ARFI, contrast enhanced ultrasound (CEUS), and CT or MRI. Tumor brightness on virtual touch tissue imaging (VTI) and shear wave velocity (SWV) were assessed before and approximately one month after RFA. Results. There were 14 residual tumors after RFA. VTI showed that all the tumors were darker after RFA. VTI was not able to distinguish the ablated lesions and the residual tumors. 13 residual tumor lesions were detected by CEUS. All completely ablated nodules had SWV demonstration of x.xx., while with those residual nodules, 6 tumors had x.xx measurement and 8 tumors had measurable SWV. nine lesions with residual tumors occurred in cirrhosis subjects and 5 lesions with residual tumors occurred in fibrosis subjects; there was no residual tumor in the normal liver subjects. Conclusion. VTI technique cannot demonstrate residual tumor post RFA. While SWV measurement of less than x.xx is likely associated with residual tumors, measurement of less than x.xx cannot exclude residual tumors. Liver cirrhosis is associated with decreased chance of a complete ablation. PMID:24895624

The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism - in vitro studies.

Science.gov (United States)

Lewicka, Małgorzata; Henrykowska, Gabriela A; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

2015-12-10

Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins - superoxide dismutase (SOD-1) and catalase (CAT) - and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets' oxygen metabolism and thus may lead to physiological dysfunction of the organism.

Radiofrequency field emitted by mobile phones and alteration of the blood-brain barrier: how strong is the experimental evidence?

International Nuclear Information System (INIS)

Lagroye, I.; Haro, E.; Billaudel, B.; Ruffie, G.; Poulletier de Gannes, F.; Taxile, M.; Laclau, M.; Veyret, B.; Leveque, P.

2006-01-01

Full text of publication follows: It is known that high power, thermal radiofrequency radiation (RFR) can alter the blood-brain barrier (BBB) permeability with a brain averaged specific absorption rate (BASAR) threshold evaluated at around 100 W/kg (1). Mobile communication technologies are using RFR with exposure guidelines for public local exposure at 2 W/kg, far lower than the threshold previously mentioned. However, in a paper recently published (2) the occurrence of BBB leakage and brain damage (presence of dark neurons) has been reported 50 days after a single 2-hour exposure of rats to a GSM-900 signal. In that investigation however, bias could have occurred as, for instance, exposed animals were mixed in terms of age (12- to 26-week old) and gender, while those differences were not taken into account in the analysis. Moreover, other groups have published contradictory results (3). Our group undertook a confirmation study of the Salford experiments within an international collaborative programme including technical improvements. Our study includes the detection of dark neurons, alteration of the permeability of the BBB and apoptosis 14 or 50 days after GSM-900 exposure. The exposure setup was the loop antenna that allows for head-only exposure. Five groups of 16 Fisher 344 rats (14 -week old) were exposed to GSM-900 during 2 hours at various SAR levels (0, 0.14 and 2.0 W/kg), or were used as cage control or positive controls. Positive controls were treated with kainic acid (10 mg/kg) or by cold injury (dry ice during 5 minutes). After exposure, rats were kept alive during 14 or 50 days to study brain damages. Then, they were anesthetized with urethane (i.p. 1.5 mg/kg), perfused with PBS and fixed with paraformaldehyde 4% (PAF 4%). Brains were extracted and put in cold PAF 4% during the following night, then placed in cold sucrose 20% during 2-3 days, frozen with isopentane and placed at -80 deg. C. Coding was done on brains. Frozen brains were cut in 3

Radiofrequency field emitted by mobile phones and alteration of the blood-brain barrier: how strong is the experimental evidence?

Energy Technology Data Exchange (ETDEWEB)

Lagroye, I.; Haro, E.; Billaudel, B.; Ruffie, G.; Poulletier de Gannes, F.; Taxile, M.; Laclau, M.; Veyret, B. [PIOM/UMR 5501 and Bioelectromagnetics laboratory/EPHE, ENSCPB, 33607 Pessac, (France); Leveque, P. [IRCOM, CNRS UMR 6615, Limoges (France)

2006-07-01

Full text of publication follows: It is known that high power, thermal radiofrequency radiation (RFR) can alter the blood-brain barrier (BBB) permeability with a brain averaged specific absorption rate (BASAR) threshold evaluated at around 100 W/kg (1). Mobile communication technologies are using RFR with exposure guidelines for public local exposure at 2 W/kg, far lower than the threshold previously mentioned. However, in a paper recently published (2) the occurrence of BBB leakage and brain damage (presence of dark neurons) has been reported 50 days after a single 2-hour exposure of rats to a GSM-900 signal. In that investigation however, bias could have occurred as, for instance, exposed animals were mixed in terms of age (12- to 26-week old) and gender, while those differences were not taken into account in the analysis. Moreover, other groups have published contradictory results (3). Our group undertook a confirmation study of the Salford experiments within an international collaborative programme including technical improvements. Our study includes the detection of dark neurons, alteration of the permeability of the BBB and apoptosis 14 or 50 days after GSM-900 exposure. The exposure setup was the loop antenna that allows for head-only exposure. Five groups of 16 Fisher 344 rats (14 -week old) were exposed to GSM-900 during 2 hours at various SAR levels (0, 0.14 and 2.0 W/kg), or were used as cage control or positive controls. Positive controls were treated with kainic acid (10 mg/kg) or by cold injury (dry ice during 5 minutes). After exposure, rats were kept alive during 14 or 50 days to study brain damages. Then, they were anesthetized with urethane (i.p. 1.5 mg/kg), perfused with PBS and fixed with paraformaldehyde 4% (PAF 4%). Brains were extracted and put in cold PAF 4% during the following night, then placed in cold sucrose 20% during 2-3 days, frozen with isopentane and placed at -80 deg. C. Coding was done on brains. Frozen brains were cut in 3

Inverse Source Data-Processing Strategies for Radio-Frequency Localization in Indoor Environments

Directory of Open Access Journals (Sweden)

Gianluca Gennarelli

2017-10-01

Full Text Available Indoor positioning of mobile devices plays a key role in many aspects of our daily life. These include real-time people tracking and monitoring, activity recognition, emergency detection, navigation, and numerous location based services. Despite many wireless technologies and data-processing algorithms have been developed in recent years, indoor positioning is still a problem subject of intensive research. This paper deals with the active radio-frequency (RF source localization in indoor scenarios. The localization task is carried out at the physical layer thanks to receiving sensor arrays which are deployed on the border of the surveillance region to record the signal emitted by the source. The localization problem is formulated as an imaging one by taking advantage of the inverse source approach. Different measurement configurations and data-processing/fusion strategies are examined to investigate their effectiveness in terms of localization accuracy under both line-of-sight (LOS and non-line of sight (NLOS conditions. Numerical results based on full-wave synthetic data are reported to support the analysis.

The safety and efficacy of a combined diode laser and bipolar radiofrequency compared with combined infrared light and bipolar radiofrequency for skin rejuvenation

Directory of Open Access Journals (Sweden)

Yeon Jin Choi

2012-01-01

Full Text Available Background: As the demand for noninvasive procedures for skin rejuvenation is increasing, combined diode laser and radiofrequency and combined infrared and radiofrequency devices have recently emerged. Aim: To compare Polaris WRA TM , a combination device of diode light and RF, and ReFirme ST TM , a combination device of infrared and bipolar RF, in terms of safety and efficacy on skin rejuvenation. Methods: Fourteen Korean volunteers of skin type II-IV, with facial laxity and periorbital rhytids, received three treatments at 3-week intervals with combined diode laser and bipolar radiofrequency (laser fluence 30 J/cm 2 , RF fluence 90 J/cm 3 on the right half of their faces and combined infrared light and bipolar radiofrequency (RF fluence 120 J/cm 3 on the left half of their faces. Clinical photos of front and bilateral sides of the subjects′ faces were taken at baseline and at 6, 9, 12 weeks after the treatment initiation. The investigators′ and the subjects′ global assessments were performed. Results: There is no statistically significant difference in the overall outcome between Polaris WRA TM and Refirme ST TM based on pre- and post-treatment objective measurements. Polaris WRA TM was more effective than Refirme ST TM at reducing wrinkles when therapeutic results of the two appliances were compared based on the patient satisfaction measurements. After the treatment with both instruments, histological increase in the production and rearrangement of collagen fibers at the dermal layer was observed. The density of the collagen fibers was more increased with the Polaris WRA TM -treated facial area than that of Refirme ST TM . Treatment was generally well tolerated, and there was no serious complication. Conclusion: In this study, both the lasers appeared to be safe, and effective methods for treating skin laxity and facial wrinkles. Combined diode laser and radiofrequency was more effective than combined infrared and radiofrequency at

The safety and efficacy of a combined diode laser and bipolar radiofrequency compared with combined infrared light and bipolar radiofrequency for skin rejuvenation.

Science.gov (United States)

Choi, Yeon Jin; Lee, Jung Yeon; Ahn, Ji Young; Kim, Myeung Nam; Park, Mi Youn

2012-01-01

As the demand for noninvasive procedures for skin rejuvenation is increasing, combined diode laser and radiofrequency and combined infrared and radiofrequency devices have recently emerged. To compare Polaris WRA(TM), a combination device of diode light and RF, and ReFirme ST(TM), a combination device of infrared and bipolar RF, in terms of safety and efficacy on skin rejuvenation. Fourteen Korean volunteers of skin type II-IV, with facial laxity and periorbital rhytids, received three treatments at 3-week intervals with combined diode laser and bipolar radiofrequency (laser fluence 30 J/cm2, RF fluence 90 J/cm3) on the right half of their faces and combined infrared light and bipolar radiofrequency (RF fluence 120 J/cm3) on the left half of their faces. Clinical photos of front and bilateral sides of the subjects' faces were taken at baseline and at 6, 9, 12 weeks after the treatment initiation. The investigators' and the subjects' global assessments were performed. There is no statistically significant difference in the overall outcome between Polaris WRA(TM) and Refirme ST(TM) based on pre- and post-treatment objective measurements. Polaris WRA(TM) was more effective than Refirme ST(TM) at reducing wrinkles when therapeutic results of the two appliances were compared based on the patient satisfaction measurements. After the treatment with both instruments, histological increase in the production and rearrangement of collagen fibers at the dermal layer was observed. The density of the collagen fibers was more increased with the Polaris WRA(TM)-treated facial area than that of Refirme ST(TM). Treatment was generally well tolerated, and there was no serious complication. In this study, both the lasers appeared to be safe, and effective methods for treating skin laxity and facial wrinkles. Combined diode laser and radiofrequency was more effective than combined infrared and radiofrequency at reducing wrinkles and pores when the therapeutic results of both the

Mutagenic and morphologic impacts of 1.8 GHz radiofrequency radiation on human peripheral blood lymphocytes (hPBLs) and possible protective role of pre-treatment with Ginkgo biloba (EGb 761)

Energy Technology Data Exchange (ETDEWEB)

Esmekaya, Meric Arda, E-mail: mericarda@yahoo.com [Department of Biophysics, Gazi University, Faculty of Medicine and Gazi Non-ionizing Radiation, Protection (GNRP) Center, Ankara (Turkey); Aytekin, Ebru [Department of Medical Genetics, Gazi University Faculty of Medicine, Ankara (Turkey); Ozgur, Elcin; Gueler, Goeknur [Department of Biophysics, Gazi University, Faculty of Medicine and Gazi Non-ionizing Radiation, Protection (GNRP) Center, Ankara (Turkey); Ergun, Mehmet Ali [Department of Medical Genetics, Gazi University Faculty of Medicine, Ankara (Turkey); Oemeroglu, Suna [Department of Histology and Embryology, Gazi University, Faculty of Medicine, Ankara (Turkey); Seyhan, Nesrin [Department of Biophysics, Gazi University, Faculty of Medicine and Gazi Non-ionizing Radiation, Protection (GNRP) Center, Ankara (Turkey)

2011-12-01

The mutagenic and morphologic effects of 1.8 GHz Global System for Mobile Communications (GSM) modulated RF (radiofrequency) radiation alone and in combination with Ginkgo biloba (EGb 761) pre-treatment in human peripheral blood lymphocytes (hPBLs) were investigated in this study using Sister Chromatid Exchange (SCE) and electron microscopy. Cell viability was assessed with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) reduction assay. The lymphocyte cultures were exposed to GSM modulated RF radiation at 1.8 GHz for 6, 8, 24 and 48 h with and without EGb 761. We observed morphological changes in pulse-modulated RF radiated lymphocytes. Longer exposure periods led to destruction of organelle and nucleus structures. Chromatin change and the loss of mitochondrial crista occurred in cells exposed to RF for 8 h and 24 h and were more pronounced in cells exposed for 48 h. Cytoplasmic lysis and destruction of membrane integrity of cells and nuclei were also seen in 48 h RF exposed cells. There was a significant increase (p < 0.05) in SCE frequency in RF exposed lymphocytes compared to sham controls. EGb 761 pre-treatment significantly decreased SCE from RF radiation. RF radiation also inhibited cell viability in a time dependent manner. The inhibitory effects of RF radiation on the growth of lymphoctes were marked in longer exposure periods. EGb 761 pre-treatment significantly increased cell viability in RF + EGb 761 treated groups at 8 and 24 h when compared to RF exposed groups alone. The results of our study showed that RF radiation affects cell morphology, increases SCE and inhibits cell proliferation. However, EGb 761 has a protective role against RF induced mutagenity. We concluded that RF radiation induces chromosomal damage in hPBLs but this damage may be reduced by EGb 761 pre-treatment. - Highlights: Black-Right-Pointing-Pointer RF Radiation inhibits cell proliferation. Black-Right-Pointing-Pointer RF radiation induces chromosomal damage

Regulation on Radiation Safety of Guatemala

International Nuclear Information System (INIS)

2001-03-01

This regulation includes all the requirements administrative, radiation protection, that licensees must meet in order to obtain authorization from the competent authority to apply and use radiation sources, equipment emiting ionizing radiation in different practices authorized

12-month efficacy of a single radiofrequency ablation on autonomously functioning thyroid nodules.

Science.gov (United States)

Bernardi, Stella; Stacul, Fulvio; Michelli, Andrea; Giudici, Fabiola; Zuolo, Giulia; de Manzini, Nicolò; Dobrinja, Chiara; Zanconati, Fabrizio; Fabris, Bruno

2017-09-01

Radiofrequency ablation has been advocated as an alternative to radioiodine and/or surgery for the treatment of autonomously functioning benign thyroid nodules. However, only a few studies have measured radiofrequency ablation efficacy on autonomously functioning benign thyroid nodules. The aim of this work was to evaluate the 12-month efficacy of a single session of radiofrequency ablation (performed with the moving shot technique) on solitary autonomously functioning benign thyroid nodules. Thirty patients with a single, benign autonomously functioning benign thyroid nodules, who were either unwilling or ineligible to undergo surgery and radioiodine, were treated with radiofrequency ablation between April 2012 and May 2015. All the patients underwent a single radiofrequency ablation, performed with the 18-gauge needle and the moving shot technique. Clinical, laboratory, and ultrasound evaluations were scheduled at baseline, and after 1, 3, 6, and 12 months from the procedure. A single radiofrequency ablation reduced thyroid nodule volume by 51, 63, 69, and 75 % after 1, 3, 6, and 12 months, respectively. This was associated with a significant improvement of local cervical discomfort and cosmetic score. As for thyroid function, 33 % of the patients went into remission after 3 months, 43 % after 6 months, and 50 % after 12 months from the procedure. This study demonstrates that a single radiofrequency ablation allowed us to withdraw anti-thyroid medication in 50 % of the patients, who remained euthyroid afterwards. This study shows that a single radiofrequency ablation was effective in 50 % of patients with autonomously functioning benign thyroid nodules. Patients responded gradually to the treatment. It is possible that longer follow-up studies might show greater response rates.

WORKSHOP: Radiofrequency superconductivity

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-10-15

The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators.

WORKSHOP: Radiofrequency superconductivity

International Nuclear Information System (INIS)

Anon.

1984-01-01

The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators

Coherent radiation from atoms and a channeled particle

International Nuclear Information System (INIS)

Epp, V.; Sosedova, M.A.

2013-01-01

Highlights: ► Impact of coherent atoms vibrations on radiation of a channeled particle is studied. ► Resonant amplification of atomic radiation is possible under certain conditions. ► Radiation of vibrating atoms forms an intense narrow peak in angular distribution. ► Radiation of atoms on resonance conditions is higher than that of channeled particle. -- Abstract: A new mechanism of radiation emitted at channeling of a relativistic charged particle in a crystal is studied. The superposition of coherent radiation from atoms, which are excited to vibrate in the crystal lattice by a channeled charged particle, with the ordinary channeling radiation is considered. It is shown that the coherent radiation from a chain of oscillating atoms forms a resonance peak on the tail of radiation emitted by the channeled particle

Hawking radiation

Science.gov (United States)

Parentani, Renaud; Spindel, Philippe

2011-12-01

Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

Bipolar Radiofrequency Facet Ablation of the Lumbar Facet Capsule: An Adjunct to Conventional Radiofrequency Ablation for Pain Management.

Science.gov (United States)

Jacobson, Robert E; Palea, Ovidiu; Granville, Michelle

2017-09-01

Radiofrequency facet ablation (RFA) has been performed using the same technique for over 50 years. Except for variations in electrode size, tip shape, and change in radiofrequency (RF) stimulation parameters, using standard, pulsed, and cooled RF wavelengths, the target points have remained absolutely unchanged from the original work describing RFA for lumbar pain control. Degenerative changes in the facet joint and capsule are the primary location for the majority of lumbar segmental pathology and pain. Multiple studies show that the degenerated facet joint is richly innervated as a result of the inflammatory overgrowth of the synovium. The primary provocative clinical test to justify an RFA is to perform an injection with local anesthetic into the facet joint and the posterior capsule and confirm pain relief. However, after a positive response, the radiofrequency lesion is made not to the facet joint but to the more proximal fine nerve branches that innervate the joint. The accepted target points for the recurrent sensory branch ignore the characteristic rich innervation of the pathologic lumbar facet capsule and assume that lesioning of these recurrent branches is sufficient to denervate the painful pathologic facet joint. This report describes the additional targets and technical steps for further coagulation points along the posterior capsule of the lumbar facet joint and the physiologic studies of the advantage of the bipolar radiofrequency current in this location. Bipolar RF to the facet capsule is a simple, extra step that easily creates a large thermo-coagulated lesion in this capsule region of the pathologic facet joint. Early studies demonstrate bipolar RF to the facet capsule can provide long-term pain relief when used alone for specific localized facet joint pain, to coagulate lumbar facet cysts to prevent recurrence, and to get more extensive pain control by combining it with traditional lumbar RFA, especially when RFA is repeated.

Radiation detectors based by polymer materials

International Nuclear Information System (INIS)

Cherestes, Margareta; Cherestes, Codrut; Constantinescu, Livia

2004-01-01

Scintillation counters make use of the property of certain chemical compounds to emit short light pulses after excitation produced by the passage of charged particles or photons of high energy. These flashes of light are detected by a photomultiplier tube that converts the photons into a voltage pulse. The light emitted from the detector also can be collected, focussed and dispersed by a CCD detector. The study of the evolution of the light emission and of the radiation damage under irradiation is a primary topic in the development of radiation hard polymer based scintillator. Polymer scintillator thin films are used in monitoring radiation beam intensities and simultaneous counting of different radiations. Radiation detectors have characteristics which depend on: the type of radiation, the energy of radiation, and the material of the detector. Three types of polymer thin films were studied: a polyvinyltoluene based scintillator, fluorinated polyimide and PMMA. (authors)

Radiofrequency ablation of pulmonary tumors

Energy Technology Data Exchange (ETDEWEB)

Crocetti, Laura, E-mail: l.crocetti@med.unipi.i [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy); Lencioni, Riccardo [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy)

2010-07-15

The development of image-guided percutaneous techniques for local tumor ablation has been one of the major advances in the treatment of solid tumors. Among these methods, radiofrequency (RF) ablation is currently established as the primary ablative modality at most institutions. RF ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma when liver transplantation or surgical resection are not suitable options and is considered as a viable alternate to surgery for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer. Recently, RF ablation has been demonstrated to be a safe and valuable treatment option for patients with unresectable or medically inoperable lung malignancies. Resection should remain the standard therapy for non-small cell lung cancer (NSCLC) but RF ablation may be better than conventional external-beam radiation for the treatment of the high-risk individual with NSCLC. Initial favourable outcomes encourage combining radiotherapy and RF ablation, especially for treating larger tumors. In the setting of colorectal cancer lung metastases, survival rates provided by RF ablation in selected patients, are substantially higher than those obtained with any chemotherapy regimens and provide indirect evidence that RF ablation therapy improves survival in patients with limited lung metastatic disease.

A New Radiofrequency Ablation Procedure to Treat Sacroiliac Joint Pain.

Science.gov (United States)

Cheng, Jianguo; Chen, See Loong; Zimmerman, Nicole; Dalton, Jarrod E; LaSalle, Garret; Rosenquist, Richard

2016-01-01

Low back pain may arise from disorders of the sacroiliac joint in up to 30% of patients. Radiofrequency ablation (RFA) of the nerves innervating the sacroiliac joint has been shown to be a safe and efficacious strategy. We aimed to develop a new RFA technique to relieve low back pain secondary to sacroiliac joint disorders. Methodology development with validation through prospective observational non-randomized trial (PONRT). Academic multidisciplinary health care system, Ohio, USA. We devised a guide-block to facilitate accurate placement of multiple electrodes to simultaneously ablate the L5 dorsal ramus and lateral branches of the S1, S2, and S3 dorsal rami. This was achieved by bipolar radiofrequency ablation (b-RFA) to create a strip lesion from the lateral border of the base of the sacral superior articular process (L5-S1 facet joint) to the lateral border of the S3 sacral foramen. We applied this technique in 31 consecutive patients and compared the operating time, x-ray exposure time and dose, and clinical outcomes with patients (n = 62) who have been treated with the cooled radiofrequency technique. Patients' level of pain relief was reported as 80% pain relief at one, 3, 6, and 12 months after the procedure. The relationship between RFA technique and duration of pain relief was evaluated using interval-censored multivariable Cox regression. The new technique allowed reduction of operating time by more than 50%, x-ray exposure time and dose by more than 80%, and cost by more than $1,000 per case. The percent of patients who achieved > 50% pain reduction was significantly higher in the b-RFA group at 3, 6, and 12 months follow-up, compared to the cooled radiofrequency group. No complications were observed in either group. Although the major confounding factors were taken into account in the analysis, use of historical controls does not balance observed and unobserved potential confounding variables between groups so that the reported results are potentially

Blind spot may reveal vacuum radiation

International Nuclear Information System (INIS)

Rosu, H.

1999-01-01

Back in the 1970s Stephen Hawking of Cambridge University in the UK made the theoretical discovery that small black holes are not 'completely black'. Instead, a black hole emits radiation with a well defined temperature that is proportional to the gravitational force at its surface. The finding uncovered a deep connection between gravity, quantum mechanics and thermodynamics. Later, Bill Unruh of the University of British Columbia in Canada proposed that quantum particles should emit thermal radiation in a similar way when they are accelerated. Now, Pisin Chen of the Stanford Linear Accelerator Center and Toshi Tajima of the University of Texas at Austin in the US have suggested that it should be possible to detect the Unruh radiation emitted by electrons that are accelerated by high-intensity lasers (Phys. Rev. Lett. 1999 83 256). In this article the author explains their proposal. (UK)

Blind spot may reveal vacuum radiation

Energy Technology Data Exchange (ETDEWEB)

Rosu, H. [Universidad de Guanajuato, Leon (Mexico)

1999-10-01

Back in the 1970s Stephen Hawking of Cambridge University in the UK made the theoretical discovery that small black holes are not 'completely black'. Instead, a black hole emits radiation with a well defined temperature that is proportional to the gravitational force at its surface. The finding uncovered a deep connection between gravity, quantum mechanics and thermodynamics. Later, Bill Unruh of the University of British Columbia in Canada proposed that quantum particles should emit thermal radiation in a similar way when they are accelerated. Now, Pisin Chen of the Stanford Linear Accelerator Center and Toshi Tajima of the University of Texas at Austin in the US have suggested that it should be possible to detect the Unruh radiation emitted by electrons that are accelerated by high-intensity lasers (Phys. Rev. Lett. 1999 83 256). In this article the author explains their proposal. (UK)

Alteration of glycine receptor immunoreactivity in the auditory brainstem of mice following three months of exposure to radiofrequency radiation at SAR 4.0 W/kg.

Science.gov (United States)

Maskey, Dhiraj; Kim, Hyung Gun; Suh, Myung-Whan; Roh, Gu Seob; Kim, Myeung Ju

2014-08-01

The increasing use of mobile communication has triggered an interest in its possible effects on the regulation of neurotransmitter signals. Due to the close proximity of mobile phones to hearing-related brain regions during usage, its use may lead to a decrease in the ability to segregate sounds, leading to serious auditory dysfunction caused by the prolonged exposure to radiofrequency (RF) radiation. The interplay among auditory processing, excitation and inhibitory molecule interactions plays a major role in auditory function. In particular, inhibitory molecules, such a glycine, are predominantly localized in the auditory brainstem. However, the effects of exposure to RF radiation on auditory function have not been reported to date. Thus, the aim of the present study was to investigate the effects of exposure to RF radiation on glycine receptor (GlyR) immunoreactivity (IR) in the auditory brainstem region at 835 MHz with a specific absorption rate of 4.0 W/kg for three months using free-floating immunohistochemistry. Compared with the sham control (SC) group, a significant loss of staining intensity of neuropils and cells in the different subdivisions of the auditory brainstem regions was observed in the mice exposed to RF radiation (E4 group). A decrease in the number of GlyR immunoreactive cells was also noted in the cochlear nuclear complex [anteroventral cochlear nucleus (AVCN), 31.09%; dorsal cochlear nucleus (DCN), 14.08%; posteroventral cochlear nucleus (PVCN), 32.79%] and the superior olivary complex (SOC) [lateral superior olivary nucleus (LSO), 36.85%; superior paraolivary nucleus (SPN), 24.33%, medial superior olivary nucleus (MSO), 23.23%; medial nucleus of the trapezoid body (MNTB), 10.15%] of the mice in the E4 group. Auditory brainstem response (ABR) analysis also revealed a significant threshold elevation of in the exposed (E4) group, which may be associated with auditory dysfunction. The present study suggests that the auditory brainstem region

Cooling system for the IFMIF-EVEDA radiofrequency system

International Nuclear Information System (INIS)

Perez Pichel, G. D.

2012-01-01

The IFMIF-EVEDA project consists on an accelerator prototype that will be installed at Rokkasho (Japan). Through CIEMAT, that is responsible of the development of many systems and components. Empresarios Agrupados get the responsibility of the detailed design of the cooling system for the radiofrequency system (RF system) that must feed the accelerator. the RF water cooling systems is the water primary circuit that provides the required water flow (with a certain temperature, pressure and water quality) and also dissipates the necessary thermal power of all the radiofrequency system equipment. (Author) 4 refs.

Cherenkov radiation

International Nuclear Information System (INIS)

Hubert, P.

1955-01-01

When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

Modification in oxidative processes in muscle tissues exposed to laser- and light-emitting diode radiation.

Science.gov (United States)

Monich, Victor A; Bavrina, Anna P; Malinovskaya, Svetlana L

2018-01-01

Exposure of living tissues to high-intensity red or near-infrared light can produce the oxidative stress effects both in the target zone and adjacent ones. The protein oxidative modification (POM) products can be used as reliable and early markers of oxidative stress. The contents of modified proteins in the investigated specimens can be evaluated by the 2,4-dinitrophenylhydrazine assay (the DNPH assay). Low-intensity red light is able to decrease the activity of oxidative processes and the DNPH assay data about the POM products in the biological tissues could show both an oxidative stress level and an efficiency of physical agent protection against the oxidative processes. Two control groups of white rats were irradiated by laser light, the first control group by red light and the second one by near-infrared radiation (NIR).Two experimental groups were consequently treated with laser and red low-level light-emitting diode radiation (LED). One of them was exposed to red laser light + LED and the other to NIR + LED. The fifth group was intact. Each group included ten animals. The effect of laser light was studied by methods of protein oxidative modifications. We measured levels of both induced and spontaneous POM products by the DNPH assay. The dramatic increase in levels of POM products in the control group samples when compared with the intact group data as well as the sharp decrease in the POM products in the experimental groups treated with LED low-level light were statistically significant (p ≤ 0.05). Exposure of skeletal muscles to high-intensity red and near-infrared laser light causes oxidative stress that continues not less than 3 days. The method of measurement of POM product contents by the DNPH assay is a reliable test of an oxidative process rate. Red low-intensity LED radiation can provide rehabilitation of skeletal muscle tissues treated with high-intensity laser light.

Comments on Meo et al. Association of Exposure to Radio-Frequency Electromagnetic Field Radiation (RF-EMFR Generated by Mobile Phone Base Stations with Glycated Hemoglobin (HbA1c and Risk of Type 2 Diabetes Mellitus. Int. J. Environ. Res. Public Health, 2015, 12, 14519–14528

Directory of Open Access Journals (Sweden)

Seyed Alireza Mortazavi

2016-02-01

Full Text Available With great interest and enthusiasm, we have read the article by Meo et al. entitled “Association of Exposure to Radio-Frequency Electromagnetic Field Radiation (RF-EMFR Generated by Mobile Phone Base Stations with Glycated Hemoglobin (HbA1c and Risk of Type 2 Diabetes Mellitus” that is published in the latest issue of the International Journal of Environmental Research and Public Health [1].[...

Fraxelated radiofrequency device for acne scars

Science.gov (United States)

Rao, Babar K.; Khokher, Sairah

2012-09-01

Acne scars can be improved with various treatments such as topical creams, chemical peels, dermal fillers, microdermabrasion, laser, and radiofrequency devices. Some of these treatments especially lasers and deep chemical peels can have significant side effects such as post inflammatory hyperpigmentation in darker skin types. Fraxelated RF Laser devices have been reported to have lower incidence of side effects in all skin phototypes. Nine patients between ages 18 and 35 of various skin phototypes were selected from a private practice and treated with a RF fraxelated device (E-matrix) for acne scars. Outcomes were measured by physician observation, subjective feedback received by patients, and comparison of before and after photographs. In this small group of patients with various skin phototypes, fraxelated radiofrequency device improved acne scars with minimal side effects and downtime.

Arthroscopic surgery using radio-frequency electrocautery

International Nuclear Information System (INIS)

Takatsuka, Shigeyuki; Yoshida, Kan; Nakagawa, Kiyomasa; Yamamoto, Etsuhide; Kubota, Yoshiyuki; Narinobou, Masayoshi; Terai, Koichi; Hasegawa, Hiroshi

2008-01-01

Arthroscopic surgery using radio-frequency electrocautery was carried out on 23 temporomandibular joints (TMJs) in 13 patients. Because these patients did not respond to conservative therapy, surgery was indicated. Preoperative MRI showed anterior disc displacement without reduction in all patients. Disturbed translation was also recognized in all of the discs and mandibular condyles. Intraoperative arthroscopic examination showed severe fibrous adhesion in the upper joint compartment and disc displacement. Four joints showed perforation between the disc and retrodiscal tissue. Postoperative findings included an increased range of vertical maximal mouth opening and decreased pain on mandibular movement. Analyses of postoperative MRI indicated recovery of disc and condylar translation. These results suggested that the introduction of arthroscopic surgery using radiofrequency electrocautery would significantly reduce the number of patients with osteoarthritic TMJ disorders. (author)

Transurethral radiofrequency collagen denaturation for the treatment of women with urinary incontinence.

Science.gov (United States)

Kang, Diana; Han, Julia; Neuberger, Molly M; Moy, M Louis; Wallace, Sheila A; Alonso-Coello, Pablo; Dahm, Philipp

2015-03-18

Transurethral radiofrequency collagen denaturation is a relatively novel, minimally invasive device-based intervention used to treat individuals with urinary incontinence (UI). No systematic review of the evidence supporting its use has been published to date. To evaluate the efficacy of transurethral radiofrequency collagen denaturation, compared with other interventions, in the treatment of women with UI.Review authors sought to compare the following.• Transurethral radiofrequency collagen denaturation versus no treatment/sham treatment.• Transurethral radiofrequency collagen denaturation versus conservative physical treatment.• Transurethral radiofrequency collagen denaturation versus mechanical devices (pessaries for UI).• Transurethral radiofrequency collagen denaturation versus drug treatment.• Transurethral radiofrequency collagen denaturation versus injectable treatment for UI.• Transurethral radiofrequency collagen denaturation versus other surgery for UI. We conducted a systematic search of the Cochrane Incontinence Group Specialised Register (searched 19 December 2014), EMBASE and EMBASE Classic (January 1947 to 2014 Week 50), Google Scholar and three trials registries in December 2014, along with reference checking. We sought to identify unpublished studies by handsearching abstracts of major gynaecology and urology meetings, and by contacting experts in the field and the device manufacturer. Randomised and quasi-randomised trials of transurethral radiofrequency collagen denaturation versus no treatment/sham treatment, conservative physical treatment, mechanical devices, drug treatment, injectable treatment for UI or other surgery for UI in women were eligible. We screened search results and selected eligible studies for inclusion. We assessed risk of bias and analysed dichotomous variables as risk ratios (RRs) with 95% confidence intervals (CIs) and continuous variables as mean differences (MDs) with 95% CIs. We rated the quality of

Solid state radiation detector system

International Nuclear Information System (INIS)

1977-01-01

A solid state radiation flux detector system utilizes a detector element, consisting of a bar of semiconductor having electrical conductance of magnitude dependent upon the magnitude of photon and charged particle flux impinging thereon, and negative feedback circuitry for adjusting the current flow through a light emitting diode to facilitate the addition of optical flux, having a magnitude decreasing in proportion to any increase in the magnitude of radiation (e.g. x-ray) flux incident upon the detector element, whereby the conductance of the detector element is maintained essentially constant. The light emitting diode also illuminates a photodiode to generate a detector output having a stable, highly linear response with time and incident radiation flux changes

Calibration techniques for the in vivo measurement of alpha-emitting actinides

International Nuclear Information System (INIS)

Fleming, R.R.

1976-01-01

Reliable interpretation of in vivo measurements for alpha-emitting actinides deposited in the lungs is largely dependent on three factors: correction of observed count rates for background contributions; correction for photon absorption in the body; and accurate calibration of the counting system. Terrestrial and cosmic radiation contributions can be minimized by extensive shielding and good pulse-shape discrimination. Techniques are available to minimize errors inherent in the calibration of an in vivo counting system. Minimum amounts of alpha-emitting actinides detectable in the lungs are primarily affected by the accuracy of two factors: predicted body background due to 137 Cs and 40 K, and estimated photon absorption in chest-wall tissue. A matched pair of 12.5-cm-dia phoswich detectors, purchased from the Harshaw Chemical Company, are used to measure low-energy photons emitted by the radioactive actinides

Bluish-green color emitting Ba2Si3O8:Eu2+ ceramic phosphors for white light-emitting diodes.

Science.gov (United States)

Xiao, F; Xue, Y N; Zhang, Q Y

2009-10-15

This paper reports on the structural and optical properties of Eu(2+) activated Ba(2)Si(3)O(8) ceramic phosphors synthesized by a sol-gel method. The ceramic phosphors have been characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and fluorescence measurements. The structural characterization results suggest that the as-prepared phosphors are of single phase monoclinic Ba(2)Si(3)O(8) with rod-like morphology. A broad excitation band ranging from 300 to 410 nm matches well with the ultraviolet (UV) radiation of light-emitting diodes (LEDs). Upon 380 nm UV light excitation, these phosphors emit bluish-green emission centered at 500 nm with color coordination (x=0.25, y=0.40). All the obtained results indicate that the Ba(2)Si(3)O(8):Eu(2+) ceramic phosphors are promising bluish-green candidates for the phosphor-converted white LEDs.

Ion collection from laser-induced plasma by applying radio-frequency voltage

International Nuclear Information System (INIS)

Shibata, Takemasa; Ogura, Koichi

1995-01-01

Ions were collected on the electrodes from a laser resonance photoionized plasma by applying 1.8MHz radio-frequency voltage to the electrode. It was demonstrated that the ions are collected in a shorter time at the same kinetic energy of the collected ions compared with ion collection by applying DC voltage to the electrode. A simple one-dimensional model was extended for prediction of ion collection times in the cases of applications of not only the DC voltage but also the radio-frequency voltage. The ion collection times estimated using the simple one-dimensional model agreed with experimental values in both cases of DC and radio-frequency voltages. (author)

Electromagnetic Radiation of Electrons in Periodic Structures

CERN Document Server

Potylitsyn, Alexander Petrovich

2011-01-01

Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

Radiofrequency waves with filling and peeling substances: An innovative minimally invasive technique for facial rejuvenation.

Science.gov (United States)

Savoia, Antonella; Vannini, Fulvio; Baldi, Alfonso

2011-09-01

This study describes a pivotal clinical trial of a new minimally invasive cosmetic procedure for facial rejuvenation and for the treatment of scars and wrinkles. The procedure consisted of a combination of techniques such as fillers, biorevitalization, peeling, and intradermal radiofrequency, emitted from a new device denominated by Spherofill Medical Plus (SMP; Spherofill MD, PromoItalia Group S.p.A., Pozzuoli, Italy), for treating cutaneous regeneration, depressions, and striae. One hundred and twelve patients, divided into five groups, were treated. The results produced were statistically analyzed and resulted in significant and long-lasting effects for facial rejuvenation. Indeed, the analysis of the Global Aesthetic Improvement Scale (GAIS) scores in the five groups demonstrated statistically significant results between 3 and 9 months after the treatments. Evaluating the patients included in the study, it is possible to conclude that the treatment with SMP represents a safe and efficient solution for the treatment of wrinkles, acne lesions, striae, and of degenerated tissues caused by aging.

Measurement of radio frequency radiation (RFR) power levels from ...

African Journals Online (AJOL)

With the upsurge in the number of network providers and the attendant increase in the installation of mast in Nigeria, the environment is being inundated with radiofrequency radiation (RFR). There is, therefore, increasing concern about the health implications of this development. In this study measurements of RFR output ...

Effect of Radiofrequency Endometrial Ablation on Dysmenorrhea.

Science.gov (United States)

Wyatt, Sabrina N; Banahan, Taylor; Tang, Ying; Nadendla, Kavita; Szychowski, Jeff M; Jenkins, Todd R

To examine rates of dysmenorrhea after radiofrequency endometrial ablation in patients with and without known dysmenorrhea symptoms prior to the procedure in a diverse population. Retrospective cohort study (Canadian Task Force classification II-2). Academic gynecology practice. A total of 307 women underwent endometrial ablation between 2007 and 2013 at our institution. Patients who had preoperative and postoperative pain symptom assessments as well as a description of pain timing recorded were included in our analysis. Exclusion criteria were age dysmenorrhea was evaluated. Demographic information and other outcome variables were used to evaluate factors associated with resolution of dysmenorrhea. A total of 307 patients who underwent radiofrequency endometrial ablation were identified. After exclusions, 296 charts were examined, and 144 patients met our enrollment criteria. The mean age of the study cohort was 45.4 ± 6.2 years; 57 patients (40%) were African American, 16 (11%) had a body mass index (BMI) > 40, and 41 (29%) were of normal weight. Preoperative dysmenorrhea was reported by 100 patients (69%); 48 of these patients (48%) experienced resolution of symptoms postoperatively. Only 3 of the 44 patients (7%) without preoperative dysmenorrhea reported new-onset dysmenorrhea postoperatively. Significantly fewer patients had dysmenorrhea after compared to before radiofrequency ablation (55 of 144 [38%] vs 100 of 144 [69%]; p dysmenorrhea after ablation was associated with reduction in bleeding volume (p = .048) but not with a reduction in frequency of bleeding (p = .12). Approximately one-half of women who undergo radiofrequency endometrial ablation to treat heavy menstrual bleeding who also have preoperative dysmenorrhea exhibit documented pain resolution after the procedure. Resolution of dysmenorrhea is more likely if menstrual flow volume is decreased postprocedure. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

POWER, METALLURGICAL AND CHEMICAL MECHANICAL ENGINEERING THERMOELECTRIC EVENTS IN LIGHT-EMITTING BIPOLAR SEMICONDUCTOR STRUCTURES

Directory of Open Access Journals (Sweden)

P. A. Magomedova

2017-01-01

Full Text Available Objective. The development of light-emitting bipolar semiconductor structures having a low level of parasitic heat release.Methods. A method for converting thermoelectric heat in bipolar semiconductor structures into optical radiation to divert the excess energy into the environment was developed. At the same time, the cooling effect on thermoelectric junctions remains. Instead of an inertial process of conductive or convective heat transfer, practically instantaneous heat removal from electronic components to the environment takes place.Results. As a result, light-emitting bipolar semiconductor structures will allow more powerful devices with greater speed and degree of integration to be created. It is possible to produce transparent LED matrices with a two-way arrangement of transparent solar cells and mirror metal electrodes along the perimeter. When current is applied, the LED matrix on one of the transitions will absorb thermal energy; on other electrodes, it will emit radiation that is completely recovered into electricity by means of transparent solar cells following repeated reflection between the mirror electrodes. The low efficiency of solar cells will be completely compensated for with the multiple passages of photons through these batteries.Conclusion. Light-emitting bipolar semiconductor structures will not only improve the reliability of electronic components in a wide range of performance characteristics, but also improve energy efficiency through the use of optical radiation recovery. Semiconductor thermoelectric devices using optical phenomena in conjunction with the Peltier effect allow a wide range of energy-efficient components of radio electronic equipment to be realised, both for discrete electronics and for microsystem techniques. Systems for obtaining ultra-low temperatures in order to achieve superconductivity are of particular value. 

Analysis of public perception of increased radiofrequency exposure from mobile phone in Southwestern Nigeria

International Nuclear Information System (INIS)

Oladapo, O.O.; Ishola, G.A.; Ayokunnnu, D.O.

2011-01-01

Wireless communication devices have been increasingly used recently in Nigeria with a corresponding public perception of increase in radiofrequency (RF) radiation. This perception has developed into public concerns, thus requiring verification. For the purpose of verification, a survey in form of an opinion poll was conducted by means of an interview using questionnaires. The survey shows that people actually experienced symptoms like headache, fatigue, dizziness, and heat sensation. However, out of the respondents that have experienced one symptoms or the other, 84% still believe it is safe to use mobile phones. Only 4 % of those that claimed they experienced symptoms had consulted a doctor in connection with the symptoms.

The effect of electromagnetic radiation emitted by display screens on cell oxygen metabolism – in vitro studies

Science.gov (United States)

Henrykowska, Gabriela A.; Pacholski, Krzysztof; Śmigielski, Janusz; Rutkowski, Maciej; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

2015-01-01

Introduction Research studies carried out for decades have not solved the problem of the effect of electromagnetic radiation of various frequency and strength on the human organism. Due to this fact, we decided to investigate the changes taking place in human blood platelets under the effect of electromagnetic radiation (EMR) emitted by LCD monitors. Material and methods The changes of selected parameters of oxygen metabolism were measured, i.e. reactive oxygen species concentration, enzymatic activity of antioxidant defence proteins – superoxide dismutase (SOD-1) and catalase (CAT) – and malondialdehyde concentration (MDA). A suspension of human blood platelets was exposed to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity for 30 and 60 min. The level of changes of the selected parameters of oxidative stress was determined after the exposure and compared to the control samples (not exposed). Results The measurements revealed an increase of the concentration of reactive oxygen species. The largest increase of ROS concentration vs. the control sample was observed after exposure to EMF of 220 V/m intensity for 60 min (from x = 54.64 to x = 72.92). The measurement of MDA concentration demonstrated a statistically significant increase after 30-min exposure to an EMF of 220 V/m intensity in relation to the initial values (from x = 3.18 to x = 4.41). The enzymatic activity of SOD-1 decreased after exposure (the most prominent change was observed after 60-min and 220 V/m intensity from x = 3556.41 to x = 1084.83). The most significant change in activity of catalase was observed after 60 min and 220 v/m exposure (from x = 6.28 to x = 4.15). Conclusions The findings indicate that exposure to electromagnetic radiation of 1 kHz frequency and 150 V/m and 220 V/m intensity may cause adverse effects within blood platelets’ oxygen metabolism and thus may lead to physiological dysfunction of the organism. PMID:26788099

Thermal and physiological responses of rats exposed to 2. 45-GHz radiofrequency radiation: A comparison of E and H orientation

Energy Technology Data Exchange (ETDEWEB)

Frei, M.R.; Jauchem, J.R.; Padilla, J.M.; Merritt, J.H.

1989-07-01

Ketamine-anesthetized Sprague-Dawley rats were exposed in both E and H orientations to far-field 2.45-GHz continuous-wave radiofrequency radiation (RFR) at a power density of 60 mW/cm/sup 2/ (wholebody average specific absorption rate of approx. = 14 W/kg). Intermittent exposures were performed in both orientations in the same animal to repeatedly increase colonic temperature from 38.5 to 39.5/sup 0/C. Tympanic, subcutaneous (sides toward and away from RFR source), and colonic temperature, ECG, arterial blood pressure, and respiratory rate were continuously recorded. The pattern of heat distribution within the animal and the physiological responses were significantly different between E- and H-orientation exposure. Irradiation in E orientation resulted in greater peripheral and tympanic heating, while irradiation in H orientation resulted in greater core heating. Heart rate and blood pressure increased significantly during irradiation and returned to baseline levels when exposure was discontinued; the increases were significantly greater in E than in H orientation. Respiratory rate increased significantly during irradiation in H, but not in E orientation. The physiological responses could have been influenced by the different levels or rates of subcutaneous and tympanic heating, or the differential between core and peripheral heating during E- and H-orientation irradiation. These results suggest that, when interpreting results of RFR exposure, animal orientation during irradiation must be considered.

Endoscopic ultrasound-guided radiofrequency ablation of the pancreas

DEFF Research Database (Denmark)

Silviu, Ungureanu Bogdan; Daniel, Pirici; Claudiu, Mărgăritescu

2015-01-01

ultrasound (EUS)-guided radiofrequency ablation (RFA) probe through a 19G needle in order to achieve a desirable necrosis area in the pancreas. Radiofrequency ablation of the head of the pancreas was performed on 10 Yorkshire pigs with a weight between 25 kg and 35 kg and a length of 40-70 cm. Using an EUS...... analysis revealed increased values of amylase, alkaline phosphatase, and gamma-glutamyl transpeptidase on the 3rd day but a decrease on the 5th day. After necropsy and isolation of the pancreas, the ablated area was easily found, describing a solid necrosis. The pathological examination revealed...

The precautionary principle in the context of mobile phone and base station radiofrequency exposures.

Science.gov (United States)

Dolan, Mike; Rowley, Jack

2009-09-01

No health hazard has been established from exposure to radiofrequency fields up to the levels recommended by the International Commission on Non-Ionizing Radiation Protection. However, in response to public concern and the perceived level of scientific uncertainty, there are continuing calls for the application of the precautionary principle to radiofrequency exposures from mobile phones and base stations. We examined the international evolution of calls for precautionary measures in relation to mobile phones and base stations, with particular focus on Australia and the United Kingdom. The precautionary principle is difficult to define, and there is no widespread agreement as to how it should be implemented. However, there is a strong argument that precautionary measures should not be implemented in the absence of reliable scientific data and logical reasoning pointing to a possible health hazard. There is also experimental evidence that precautionary advice may increase public concern. We argue that conservative exposure standards, technical features that minimize unnecessary exposures, ongoing research, regular review of standards, and availability of consumer information make mobile communications inherently precautionary. Commonsense measures can be adopted by individuals, governments, and industry to address public concern while ensuring that mobile networks are developed for the benefit of society.

Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism

Science.gov (United States)

Volkow, Nora D.; Tomasi, Dardo; Wang, Gene-Jack; Vaska, Paul; Fowler, Joanna S.; Telang, Frank; Alexoff, Dave; Logan, Jean; Wong, Christopher

2011-01-01

Context The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain. However, whether acute cell phone exposure affects the human brain is unclear. Objective To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity. Design, Setting, and Participants Randomized crossover study conducted between January 1 and December 31, 2009, at a single US laboratory among 47 healthy participants recruited from the community. Cell phones were placed on the left and right ears and positron emission tomography with (18F)fluorodeoxyglucose injection was used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes (“on” condition) and once with both cell phones deactivated (“off” condition). Statistical parametric mapping was used to compare metabolism between on and off conditions using paired t tests, and Pearson linear correlations were used to verify the association of metabolism and estimated amplitude of radiofrequency-modulated electromagnetic waves emitted by the cell phone. Clusters with at least 1000 voxels (volume >8 cm3) and P < .05 (corrected for multiple comparisons) were considered significant. Main Outcome Measure Brain glucose metabolism computed as absolute metabolism (µmol/100 g per minute) and as normalized metabolism (region/whole brain). Results Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher for on than off conditions (35.7 vs 33.3 µmol/100 g per minute; mean difference, 2.4 [95% confidence interval, 0.67–4.2]; P = .004). The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism (R = 0.95, P < .001) and normalized metabolism (R = 0.89; P < .001

Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucos Metabolism

International Nuclear Information System (INIS)

Volkow, N.D.; Tomasi, D.; Wang, G.-J.; Vaska, P.; Fowler, J.S.; Telang, F.; Alexoff, D.; Logan, J.; Wong, C.

2011-01-01

The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain. However, whether acute cell phone exposure affects the human brain is unclear. To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity. Randomized crossover study conducted between January 1 and December 31, 2009, at a single US laboratory among 47 healthy participants recruited from the community. Cell phones were placed on the left and right ears and positron emission tomography with ( 18 F)fluorodeoxyglucose injection was used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes ('on' condition) and once with both cell phones deactivated ('off' condition). Statistical parametric mapping was used to compare metabolism between on and off conditions using paired t tests, and Pearson linear correlations were used to verify the association of metabolism and estimated amplitude of radiofrequency-modulated electromagnetic waves emitted by the cell phone. Clusters with at least 1000 voxels (volume >8 cm 3 ) and P < .05 (corrected for multiple comparisons) were considered significant. Brain glucose metabolism computed as absolute metabolism ((micro)mol/100 g per minute) and as normalized metabolism (region/whole brain). Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher for on than off conditions (35.7 vs 33.3 (micro)mol/100 g per minute; mean difference, 2.4 (95% confidence interval, 0.67-4.2); P = .004). The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism (R = 0.95, P < .001) and normalized metabolism (R = 0.89; P < .001). In healthy participants and compared with no exposure, 50-minute cell phone

Multipole resonance in the interaction of a spherical Ag nanoparticle with an emitting dipole

International Nuclear Information System (INIS)

Liu Jia-Dong; Song Feng; Zhang Jun; Wang Feng-Xiao; Wang Li-Chao; Liu Shu-Jing

2014-01-01

The effect of multipole resonance in the interaction between a spherical metallic nanoparticle (MNP) and an emitting dipole is studied with the Mie theory. The results show that the absorption peak of the MNP with respect to the field of the emitting dipole is blue-shifted with the decrease of the spacing between MNP and emitting dipole due to the enhanced multipole resonance. At a short distance, the enhanced multipole terms of scattering are not obvious compared with the dipole term. For the decay rate of the emitting dipole, multipole resonance brings about the enhancement of it largely at short spacing. For the radiative decay rate, the behavior is quite different. The dipole term is dominant at a short spacing, and the multipole term is dominant at a larger spacing. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia.

Science.gov (United States)

Zhang, W C; Zhong, W X; Li, S T; Zheng, X S; Yang, M; Shi, J

2012-03-01

Although radiofrequency thermocoagulation is considered as a primary treatment for most patients with trigeminal neuralgia, neuronavigator-guided percutaneous radiofrequency thermocoagulation has been rarely reported. The object of this study was to assess the clinical value of neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia. The radiofrequency thermocoagulation was performed in 100 cases of trigeminal neuralgia. The patients were positioned supine or sitting, under Hartel's technique (reported by Sweet and Wepsic J Neurosurg 40:143-156, 1974), by anterior lateral facial approaches. The Gasserian ganglions were acupunctured, assisted by intraoperative CT scanning (3-digital reconstruction) and electrophysiology in order to accurately locate target. The needles located in oval foramen at the first puncture, the direction and position could be defined according to the electrophysiology examination. The pain alleviated immediately after operation. There occurred no serious complication and other nerve injury in all patients despite face numbness only. 3D-CT and electrophysiology Gasser's ganglion locations can raise the success rate of puncture, enhance the safety and reduce the incidence of complication, showing high academic value and its promising future.

Somatostatin-receptor-targeted α-emitting 213Bi is therapeutically more effective than β--emitting 177Lu in human pancreatic adenocarcinoma cells

International Nuclear Information System (INIS)

Nayak, Tapan K.; Norenberg, Jeffrey P.; Anderson, Tamara L.; Prossnitz, Eric R.; Stabin, Michael G.; Atcher, Robert W.

2007-01-01

Introduction: Advance clinical cancer therapy studies of patients treated with somatostatin receptor (sstr)-targeted [DOTA 0 -Tyr 3 ]octreotide (DOTATOC) labeled with low-linear-energy-transfer (LET) β - -emitters have shown overall response rates in the range of 15-33%. In order to improve outcomes, we sought to compare the therapeutic effectiveness of sstr-targeted high-LET α-emitting 213 Bi to that of low-LET β - -emitting 177 Lu by determining relative biological effectiveness (RBE) using the external γ-beam of 137 Cs as reference radiation. Methods: Sstr-expressing human pancreatic adenocarcinoma Capan-2 cells and A549 control cells were used for this study. The effects of different radiation doses of 213 Bi and 177 Lu labeled to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid and sstr-targeted DOTATOC were investigated with a clonogenic cell survival assay. Apoptosis was measured using the Cell Death Detection ELISA PLUS 10x kit. Results: Using equimolar DOTATOC treatment with concurrent irradiation with a 137 Cs source as reference radiation, the calculated RBE of [ 213 Bi]DOTATOC was 3.4, as compared to 1.0 for [ 177 Lu]DOTATOC. As measured in terms of absorbance units, [ 213 Bi]DOTATOC caused a 2.3-fold-greater release of apoptosis-specific mononucleosomes and oligonucleosomes than [ 177 Lu]DOTATOC at the final treatment time of 96 h (P 213 Bi]DOTATOC is therapeutically more effective in decreasing survival than is [ 177 Lu]DOTATOC in human pancreatic adenocarcinoma cells due to its comparatively higher RBE

DISCERNING THE GAMMA-RAY-EMITTING REGION IN THE FLAT SPECTRUM RADIO QUASARS

Energy Technology Data Exchange (ETDEWEB)

Zheng, Y. G. [Department of Physics, Yunnan Normal University, Kunming, 650092 (China); Yang, C. Y.; Wang, J. C. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Zhang, L., E-mail: ynzyg@ynu.edu.cn, E-mail: chyy@ynao.ac.cn [Department of Astronomy, Yunnan University, Kunming, 650091 (China)

2017-01-01

A model-dependent method is proposed to determine the location of the γ -ray-emitting region for a given flat spectrum radio quasar (FSRQ). In the model, the extra-relativistic electrons are injected at the base of the jet and non-thermal photons are produced by both synchrotron radiation and inverse-Compton (IC) scattering in the energy dissipation region. The target photons dominating IC scattering originate from both synchrotron photons and external ambient photon fields, and the energy density of external radiation field is a function of the distance between the position of the dissipation region and a central supermassive black hole, and their spectra are seen in the comoving frame. Moreover, the energy dissipation region could be determined by the model parameter through reproducing the γ -ray spectra. Such a model is applied to reproduce the quasi-simultaneous multi-wavelength observed data for 36 FSRQs. In order to define the width of the broad-line region (BLR) shell and dusty molecular torus (MT) shell, a simple numerical constraint is used to determine the outer boundary of the BLR and dusty MT. Our results show that (1) the γ -ray-emitting regions are located at the range from 0.1 to 10 pc; (2) the γ -ray-emitting regions are located outside the BLRs and within the dusty molecular tori; and (3) the γ -ray-emitting regions are located closer to the dusty MT ranges than the BLRs. Therefore, it may be concluded that direct evidence for the far site scenario could be obtained on the basis of the model results.

Feasibility of Noninvasive Temperature Assessment During Radiofrequency Liver Ablation on Computed Tomography

NARCIS (Netherlands)

Pandeya, Ganga D.; Greuter, Marcel J. W.; de Jong, Koert P.; Schmidt, Bernhard; Flohr, Thomas; Oudkerk, Matthijs

2011-01-01

Purpose: The purpose of this study was to assess the feasibility of noninvasive thermometry using high-resolution computer tomography (CT) for the monitoring of bovine liver during radiofrequency (RF) ablation. Methods: Radiofrequency probes were used to ablate bovine livers from 20 degrees C to 98

Ophthalmic branch radiofrequency thermocoagulation for atypical trigeminal neuralgia:a case report.

Science.gov (United States)

Du, Shibin; Ma, Xiaoliang; Li, Xiaoqin; Yuan, Hongjie

2015-01-01

Trigeminal neuralgia is an intense neuralgia involving facial areas supplied by trigeminal nerve. The pain is characterized by sudden onset, short persistence, sharp or lancinating. Trigeminal neuralgia commonly affects frontal areas, infraorbital or paranasal areas, mandibular areas and teeth. While Trigeminal neuralgia affecting merely the upper eyelid is rare. Here we report a case of atypical Trigeminal neuralgia confined to the upper eyelid. The patient was pain free during the follow-up period of 6 months after unusual ophthalmic branch radiofrequency thermocoagulation. A 55-year-old female patient was diagnosed as primary trigeminal neuralgia involving the right upper eyelid. As the pain could not be controlled by drug therapy, peripheral nerve branch radiofrequency thermocoagulation was recommended. A combination of infratrochlear, supratrochlear and lacrimal radiofrequency thermocoagulation was implemented in this case. The point where the bridge of the nose abuts the supraorbital ridge and the point slightly above the lateral canthus along outer border of the orbit were selected respectively as the puncture sites. After positive diagnostic test, radiofrequency thermocoagulation of the above-mentioned nerve branches was performed respectively. The patient was pain free immediately after the treatment and during the follow-up period of 6 months. Trigeminal neuralgia is a common severe and chronic facial neuralgia which requires accurate diagnosis and effective therapy. With typical clinical symptoms, normal neurological signs, normal CT and MRI findings, the patient was diagnosed as classic trigeminal neuralgia. As the patient was drug resistant, some invasive treatments were considered. Peripheral branch neurolysis was chosen for its minimal invasiveness, convenience, low risk and not affecting further invasive treatments. According to the anatomic data and the diagnostic test results, infratrochlear, supratrochlear and lacrimal nerve were responsible

Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation - a systematic review.

Science.gov (United States)

Ho, Kwo Wei David; Przkora, Rene; Kumar, Sanjeev

2017-12-28

Sphenopalatine ganglion is the largest collection of neurons in the calvarium outside of the brain. Over the past century, it has been a target for interventional treatment of head and facial pain due to its ease of access. Block, radiofrequency ablation, and neurostimulation have all been applied to treat a myriad of painful syndromes. Despite the routine use of these interventions, the literature supporting their use has not been systematically summarized. This systematic review aims to collect and summarize the level of evidence supporting the use of sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Medline, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were reviewed for studies on sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Studies included in this review were compiled and analyzed for their treated medical conditions, study design, outcomes and procedural details. Studies were graded using Oxford Center for Evidence-Based Medicine for level of evidence. Based on the level of evidence, grades of recommendations are provided for each intervention and its associated medical conditions. Eighty-three publications were included in this review, of which 60 were studies on sphenopalatine ganglion block, 15 were on radiofrequency ablation, and 8 were on neurostimulation. Of all the studies, 23 have evidence level above case series. Of the 23 studies, 19 were on sphenopalatine ganglion block, 1 study on radiofrequency ablation, and 3 studies on neurostimulation. The rest of the available literature was case reports and case series. The strongest evidence lies in using sphenopalatine ganglion block, radiofrequency ablation and neurostimulation for cluster headache. Sphenopalatine ganglion block also has evidence in treating trigeminal neuralgia, migraines, reducing the needs of analgesics after endoscopic sinus surgery and reducing pain associated with nasal packing

Continuous Emission of A Radiation Quantum

International Nuclear Information System (INIS)

Zheng-Johansson, J X

2013-01-01

It is in accordance with such experiments as single photon self-interference that a photon, conveying one radiation energy quantum h × frequency , is spatially extensive and stretches an electromagnetic wave train. A wave train, hence an energy quantum, can only be emitted (or absorbed) by its source (or absorber) gradually. In both two processes the wave and ''particle'' attributes of the radiation field are simultaneously prominent, where an overall satisfactory theory has been lacking; for the latter process no known theoretical description currently exists. This paper presents a first principles treatment, in a unified framework of the classical and quantum mechanics, of the latter process, the emission (similarly absorption) of a single radiation quantum based on the dynamics of the radiation-emitting source, a charged oscillator, which is itself extensive across the potential well in which it oscillates. During the emission of one single radiation quantum, the extensive charged oscillator undergoes a continuous radiation damping and is non-stationary. This process is in this work treated using a quasi stationary approach, whereby the classical equation of motion, which directly facilitates the correspondence principle for a particle oscillator, and the quantum wave equation are established for each sufficiently brief time interval. As an inevitable consequence of the division of the total time for emitting one single quantum, a fractional Planck constant h is introduced. The solutions to the two simultaneous equations yield for the charged oscillator a continuously exponentially decaying Hamiltonian that is at the same time quantised with respect to the fractional-h at any instant of time; and the radiation wave field emitted over time stretches a wave train of finite length. The total system of the source and radiation field maintains at any time (integer n times) one whole energy quantum, (n×) h× frequency, in complete accordance with

Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

International Nuclear Information System (INIS)

Kulkarni, A.; Bak, M. S.; Ha, S.; Joshirao, P.; Manchanda, V.; Kim, T.

2015-01-01

A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO 3 ) 4 ⋅ 5H 2 O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories

Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

Science.gov (United States)

Kulkarni, A.; Ha, S.; Joshirao, P.; Manchanda, V.; Bak, M. S.; Kim, T.

2015-06-01

A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO3)4 ṡ 5H2O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

Energy Technology Data Exchange (ETDEWEB)

Kulkarni, A.; Bak, M. S., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Ha, S. [SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Joshirao, P.; Manchanda, V. [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, T., E-mail: tkim@skku.edu, E-mail: moonsoo@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2015-06-15

A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO{sub 3}){sub 4} ⋅ 5H{sub 2}O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

A Physical Model of Pulsars as Gravitational Shielding and Oscillating Neutron Stars

Directory of Open Access Journals (Sweden)

Zhang T. X.

2015-04-01

Full Text Available Pulsars are thought to be fast rotating neutron stars, synchronously emitting periodic Dirac-delta-shape radio-frequency pulses and Lorentzian-shape oscillating X-rays. The acceleration of charged particles along the magnetic field lines of neutron stars above the magnetic poles that deviate from the rotating axis initiates coherent beams of ra- dio emissions, which are viewed as pulses of radiation whenever the magnetic poles sweep the viewers. However, the conventional lighthouse model of pulsars is only con- ceptual. The mechanism through which particles are accelerated to produce coherent beams is still not fully understood. The process for periodically oscillating X-rays to emit from hot spots at the inner edge of accretion disks remains a mystery. In addition, a lack of reflecting X-rays of the pulsar by the Crab Nebula in the OFF phase does not support the lighthouse model as expected. In this study, we develop a physical model of pulsars to quantitatively interpret the emission characteristics of pulsars, in accor- dance with the author’s well-developed five-dimensional fully covariant Kaluza-Klein gravitational shielding theory and the physics of thermal and accelerating charged par- ticle radiation. The results obtained from this study indicate that, with the significant gravitational shielding by scalar field, a neutron star nonlinearly oscillates and produces synchronous periodically Dirac-delta-shape radio-frequency pulses (emitted by the os- cillating or accelerating charged particles as well as periodically Lorentzian-shape os- cillating X-rays (as the thermal radiation of neutron stars whose temperature varies due to the oscillation. This physical model of pulsars broadens our understanding of neu- tron stars and develops an innovative mechanism to model the emissions of pulsars.

Calculating the radiation characteristics of accelerated electrons in laser-plasma interactions

International Nuclear Information System (INIS)

Li, X. F.; Yu, Q.; Qu, J. F.; Kong, Q.; Gu, Y. J.; Ma, Y. Y.; Kawata, S.

2016-01-01

In this paper, we studied the characteristics of radiation emitted by electrons accelerated in a laser–plasma interaction by using the Lienard–Wiechert field. In the interaction of a laser pulse with a underdense plasma, electrons are accelerated by two mechanisms: direct laser acceleration (DLA) and laser wakefield acceleration (LWFA). At the beginning of the process, the DLA electrons emit most of the radiation, and the DLA electrons emit a much higher peak photon energy than the LWFA electrons. As the laser–plasma interaction progresses, the LWFA electrons become the major radiation emitter; however, even at this stage, the contribution from DLA electrons is significant, especially to the peak photon energy.

SPEAKING IN LIGHT - Jupiter radio signals as deflections of light-emitting electron beams in a vacuum chamber

Science.gov (United States)

Petrovic, K.

2015-10-01

Light emitting electron beam generated in a vacuum chamber is used as a medium for visualizing Jupiter's electromagnetic radiation. Dual dipole array antenna is receiving HF radio signals that are next amplified to radiate a strong electromagnetic field capable of influencing the propagation of electron beam in plasma. Installation aims to provide a platform for observing the characteristics of light emitting beam in 3D, as opposed to the experiments with cathode ray tubes in 2-dimensional television screens. Gas giant 'speaking' to us by radio waves bends the light in the tube, allowing us to see and hear the messages of Jupiter - God of light and sky.

Health Effects of Non-Ionizing Radiation on Human

International Nuclear Information System (INIS)

Zubaidah-Alatas; Yanti Lusiyanti

2001-01-01

Increases of development and use of equipment that procedures non-ionizing radiant energy such as laser, radar, microwave ovens, power lines and hand phones, bring about public concern about the possible health effects owing to the non-ionizing radiation exposure. Non ionizing electromagnetic radiation compared to ionizing radiation, has longer wavelength, lower frequency, and lower photon energy in its interaction with body tissues. The term on non-ionizing radiation refers to the groups of electromagnetic radiations with energies less than about 10 eV corresponding to wavelengths in the ultraviolet, visible, infra red microwave and radiofrequency spectral regions. This paper describes the current state of knowledge about types of non-ionizing radiation and the health effects at molecular and cellular levels as well as its effects on human health. (author)

GaN-Based Multiple-Quantum-Well Light-Emitting Diodes Employing Nanotechnology for Photon Management

KAUST Repository

Hsiao, Yu Hsuan; Tsai, Meng Lin; He, Jr-Hau

2015-01-01

Nanostructures have been proved to be an efficient way of modifying/improving the performance of GaN-based light-emitting diodes (LEDs). The achievements in photon management include strain relaxation, light extraction enhancement, radiation pattern

Cooled radiofrequency denervation for treatment of sacroiliac joint pain: two-year results from 20 cases

Science.gov (United States)

Ho, Kok-Yuen; Hadi, Mohamed Abdul; Pasutharnchat, Koravee; Tan, Kian-Hian

2013-01-01

Background Sacroiliac joint pain is a common cause of chronic low back pain. Different techniques for radiofrequency denervation of the sacroiliac joint have been used to treat this condition. However, results have been inconsistent because the variable sensory supply to the sacroiliac joint is difficult to disrupt completely using conventional radiofrequency. Cooled radiofrequency is a novel technique that uses internally cooled radiofrequency probes to enlarge lesion size, thereby increasing the chance of completely denervating the sacroiliac joint. The objective of this study was to evaluate the efficacy of cooled radiofrequency denervation using the SInergy™ cooled radiofrequency system for sacroiliac joint pain. Methods The charts of 20 patients with chronic sacroiliac joint pain who had undergone denervation using the SInergy™ cooled radiofrequency system were reviewed at two years following the procedure. Outcome measures included the Numeric Rating Scale for pain intensity, Patient Global Impression of Change, and Global Perceived Effect for patient satisfaction. Results Fifteen of 20 patients showed a significant reduction in pain (a decrease of at least three points on the Numeric Rating Scale). Mean Numeric Rating Scale for pain decreased from 7.4 ± 1.4 to 3.1 ± 2.5, mean Patient Global Impression of Change was “improved” (1.4 ± 1.5), and Global Perceived Effect was reported to be positive in 16 patients at two years following the procedure. Conclusion Cooled radiofrequency denervation showed long-term efficacy for up to two years in the treatment of sacroiliac joint pain. PMID:23869175

Development of Radiation-Resistant In-Water Wireless Transmission System Using Light Emitting Diodes and Photo Diodes

Science.gov (United States)

Takeuchi, T.; Shibata, H.; Otsuka, N.; Uehara, T.; Tsuchiya, K.; Shibagaki, T.; Komanome, H.

2016-10-01

Several kinds of commercially available light emitting diodes (LED) and photo diodes (PD) were irradiated with 60Co gamma ray up to 1 MGy for development of a radiation-resistant in-water wireless transmission system using visible light. The lens parts of the LEDs turned brown by the irradiation and their colors became dark with the absorbed dose. The total luminous fluxes decreased with the absorbed dose and the LED with shorter emission wavelength had the higher decrease rate. Meanwhile, the current-voltage characteristics hardly changed. These results indicate that the decreases of the total luminous flux of the LEDs were mainly caused not by the degradation of the semiconductor parts but by the coloring of the lens parts by the irradiation. On the other hand, the light sensitivities of the PDs decreased with the absorbed dose. The PDs with the window part which turned a darker color had the higher decrease rate. These results indicate that the decreases of light sensitivities of the PDs were also mainly caused by the coloring of the resin parts by the irradiation. If the wireless transmission is performed using the candidate LED and PD between 5 meters in water, using a few LEDs and PDs, the PD's output current generated by the emission light of the LED is estimated to be detectable even considering the effects of the absorption of the light in water and the increased dark current by the irradiation. Therefore, a radiation resistant in-water transmission system can be constructed using commercially available LEDs and PDs in principle.

Combination acetabular radiofrequency ablation and cementoplasty using a navigational radiofrequency ablation device and ultrahigh viscosity cement: technical note.

Science.gov (United States)

Wallace, Adam N; Huang, Ambrose J; Vaswani, Devin; Chang, Randy O; Jennings, Jack W

2016-03-01

Percutaneous radiofrequency ablation and cementoplasty is an alternative palliative therapy for painful metastases involving axial load-bearing bones. This technical report describes the use of a navigational radiofrequency probe to ablate acetabular metastases from an anterior approach followed by instillation of ultrahigh viscosity cement under CT-fluoroscopic guidance. The tumor ablation databases of two institutions were retrospectively reviewed to identify patients who underwent combination acetabular radiofrequency ablation and cementoplasty using the STAR Tumor Ablation and StabiliT Vertebral Augmentation Systems (DFINE; San Jose, CA). Pre-procedure acetabular tumor volume was measured on cross-sectional imaging. Pre- and post-procedure pain scores were measured using the Numeric Rating Scale (10-point scale) and compared. Partial pain improvement was categorically defined as ≥ 2-point pain score reduction. Patients were evaluated for evidence of immediate complications. Electronic medical records were reviewed for evidence of delayed complications. During the study period, 12 patients with acetabular metastases were treated. The median tumor volume was 54.3 mL (range, 28.3-109.8 mL). Pre- and post-procedure pain scores were obtained from 92% (11/12) of the cohort. The median pre-procedure pain score was 8 (range, 3-10). Post-procedure pain scores were obtained 7 days (82%; 9/11), 11 days (9.1%; 1/11) or 21 days (9.1%; 1/11) after treatment. The median post-treatment pain score was 3 (range, 1-8), a statistically significant difference compared with pre-treatment (P = 0.002). Categorically, 73% (8/11) of patients reported partial pain relief after treatment. No immediate symptomatic complications occurred. Three patients (25%; 3/12) were discharged to hospice within 1 week of treatment. No delayed complications occurred in the remaining 75% (9/12) of patients during median clinical follow-up of 62 days (range, 14-178 days). Palliative percutaneous

Molecular-scale simulation of electroluminescence in a multilayer white organic light-emitting diode

DEFF Research Database (Denmark)

Mesta, Murat; Carvelli, Marco; de Vries, Rein J

2013-01-01

we show that it is feasible to carry out Monte Carlo simulations including all of these molecular-scale processes for a hybrid multilayer organic light-emitting diode combining red and green phosphorescent layers with a blue fluorescent layer. The simulated current density and emission profile......In multilayer white organic light-emitting diodes the electronic processes in the various layers--injection and motion of charges as well as generation, diffusion and radiative decay of excitons--should be concerted such that efficient, stable and colour-balanced electroluminescence can occur. Here...

Osteoid osteoma of the spine: CT-guided monopolar radiofrequency ablation

Energy Technology Data Exchange (ETDEWEB)

Martel, Jose [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain)], E-mail: jmartel@fhalcorcon.es; Bueno, Angel [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain); Nieto-Morales, M Luisa [Servicio de Radiologia, Hospital Universitario de Tenerife (Spain); Ortiz, Eduardo J. [Departamento de Cirugia Ortopedica, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain)

2009-09-15

CT-guided percutaneous radiofrequency ablation and laser photocoagulation have become the methods of choice for the treatment of all osteoid osteomas except those in contact with neural structures. We report 10 patients with spinal osteoid osteoma adjacent to the neural elements treated with 12 sessions of CT-guided monopolar radiofrequency ablation. The size range of the lesion was 3-14 mm (mean, 7.5 mm) and the distance between the nidus and the adjacent spinal cord or nerve root was 2-12 mm (mean, 5 mm). No intact cortex between the tumor and the spinal cord or nerve roots constituted an exclusion criterion because of a higher risk of undesirable neurotoxic effects. Patients were under general anesthesia. After location of the lesion, a 11G-bone biopsy was introduced into the nidus. The radiofrequency electrode was inserted through the biopsy needle and heated at 90 deg. C for 4 min. Primary success was obtained in eight patients. At follow-up (mean, 19.5 months; range, 6-24 months), pain persisted in two patients after 2 months. Both of them were re-treated. All patients are currently pain-free and complications were not detected. In our opinion, radiofrequency ablation can also be considered the treatment of choice for spinal osteoid osteoma.

Long-wave plasma radiofrequency ablation for treatment of xanthelasma palpebrarum.

Science.gov (United States)

Baroni, Adone

2018-03-01

Xanthelasma palpebrarum is the most common type of xanthoma affecting the eyelids. It is characterized by asymptomatic soft yellowish macules, papules, or plaques over the upper and lower eyelids. Many treatments are available for management of xanthelasma palpebrarum, the most commonly used include surgical excision, ablative CO 2 or erbium lasers, nonablative Q-switched Nd:YAG laser, trichloroacetic acid peeling, and radiofrequency ablation. This study aims to evaluate the effectiveness of RF ablation in the treatment of xanthelasma palpebrarum, with D.A.S. Medical portable device (Technolux, Italia), a radiofrequency tool working with long-wave plasma energy and without anesthesia. Twenty patients, 15 female and 5 male, affected by xanthelasma palpebrarum, were enrolled for long-wave plasma radiofrequency ablation treatment. The treatment consisted of 3/4 sessions that were carried out at intervals of 30 days. Treatments were well tolerated by all patients with no adverse effects and optimal aesthetic results. The procedure is very fast and can be performed without anesthesia because of the low and tolerable pain stimulation. Long-wave plasma radiofrequency ablation is an effective option for treatment of xanthelasma palpebrarum and adds an additional tool to the increasing list of medical devices for aesthetic treatments. © 2018 Wiley Periodicals, Inc.

Osteoid osteoma of the spine: CT-guided monopolar radiofrequency ablation

International Nuclear Information System (INIS)

Martel, Jose; Bueno, Angel; Nieto-Morales, M Luisa; Ortiz, Eduardo J.

2009-01-01

CT-guided percutaneous radiofrequency ablation and laser photocoagulation have become the methods of choice for the treatment of all osteoid osteomas except those in contact with neural structures. We report 10 patients with spinal osteoid osteoma adjacent to the neural elements treated with 12 sessions of CT-guided monopolar radiofrequency ablation. The size range of the lesion was 3-14 mm (mean, 7.5 mm) and the distance between the nidus and the adjacent spinal cord or nerve root was 2-12 mm (mean, 5 mm). No intact cortex between the tumor and the spinal cord or nerve roots constituted an exclusion criterion because of a higher risk of undesirable neurotoxic effects. Patients were under general anesthesia. After location of the lesion, a 11G-bone biopsy was introduced into the nidus. The radiofrequency electrode was inserted through the biopsy needle and heated at 90 deg. C for 4 min. Primary success was obtained in eight patients. At follow-up (mean, 19.5 months; range, 6-24 months), pain persisted in two patients after 2 months. Both of them were re-treated. All patients are currently pain-free and complications were not detected. In our opinion, radiofrequency ablation can also be considered the treatment of choice for spinal osteoid osteoma.

Study of variations of radiofrequency power density from mobile phone base stations with distance

International Nuclear Information System (INIS)

Ayinmode, B. O.; Farai, I. P.

2013-01-01

The variations of radiofrequency (RF) radiation power density with distance around some mobile phone base stations (BTSs), in ten randomly selected locations in Ibadan, western Nigeria, were studied. Measurements were made with a calibrated hand-held spectrum analyser. The maximum Global System of Mobile (GSM) communication 1800 signal power density was 323.91 μW m -2 at 250 m radius of a BTS and that of GSM 900 was 1119.00 μW m -2 at 200 m radius of another BTS. The estimated total maximum power density was 2972.00 μW m -2 at 50 m radius of a different BTS. This study shows that the maximum carrier signal power density and the total maximum power density from a BTS may be observed averagely at 200 and 50 m of its radius, respectively. The result of this study demonstrates that exposure of people to RF radiation from phone BTSs in Ibadan city is far less than the recommended limits by International scientific bodies. (authors)

A Simulation Study of a Radiofrequency Localization System for Tracking Patient Motion in Radiotherapy.

Science.gov (United States)

Ostyn, Mark; Kim, Siyong; Yeo, Woon-Hong

2016-04-13

One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF) localization system designed to track intrafraction motion (target motion during the radiation treatment). This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range) for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a localization estimate and angular resolution of sensors (signal receivers) in a simulated room. The results indicate that the external sensor needs an angular resolution of about 0.03 degrees to achieve millimeter-level localization accuracy in a treatment room. This fundamental study of a novel RF localization system offers the groundwork to design a radiotherapy-compatible patient positioning system for active motion compensation.

A Simulation Study of a Radiofrequency Localization System for Tracking Patient Motion in Radiotherapy

Directory of Open Access Journals (Sweden)

Mark Ostyn

2016-04-01

Full Text Available One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF localization system designed to track intrafraction motion (target motion during the radiation treatment. This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a localization estimate and angular resolution of sensors (signal receivers in a simulated room. The results indicate that the external sensor needs an angular resolution of about 0.03 degrees to achieve millimeter-level localization accuracy in a treatment room. This fundamental study of a novel RF localization system offers the groundwork to design a radiotherapy-compatible patient positioning system for active motion compensation.

Radiofrequency energy in the arthroscopic treatment of knee chondral lesions: a systematic review.

Science.gov (United States)

Rocco, Papalia; Lorenzo, Diaz Balzani; Guglielmo, Torre; Michele, Paciotti; Nicola, Maffulli; Vincenzo, Denaro

2016-03-01

Cartilage debridement is one of the recommended procedures for the management of chondral defects. Radiofrequency probes allow to debride the cartilage, but may induce subchondral bone necrosis. Medline, Cochrane and Google Scholar were searched to identify studies on arthroscopic debridement of the articular cartilage of the knee using radiofrequency chondroplasty. The methodological quality of the studies was assessed using the Coleman methodology score (CMS). Monopolar and bipolar radiofrequency devices provide significantly better clinical outcomes, especially for patients with high-grade chondral lesions, compared with mechanical shaver only. Despite the original concerns regarding subchondral bone necrosis, low complication rates are reported. Heterogeneity in terms of type of device does not allow sound comparison of the published results. There is lack of evidence on the long-term effects of radiofrequency chondroplasty. Study methodology should be improved: the average Coleman methodology score was 56.2 out of 100. More comparative, well-designed and larger cohort trials are needed to ascertain whether radiofrequency chondroplasty offers long-term benefits over other simpler and more economical alternatives. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Radiation effects in optoelectronic devices

International Nuclear Information System (INIS)

Barnes, C.E.

1977-03-01

A summary is given of studies on radiation effects in light-emitting diodes, laser diodes, detectors, optical isolators and optical fibers. It is shown that the study of radiation damage in these devices can provide valuable information concerning the nature of the devices themselves, as well as methods of hardening these devices for applications in radiation environments

Electromagnetic radiation from a laser wakefield accelerator

NARCIS (Netherlands)

Khachatryan, A.G.; van Goor, F.A.; Boller, Klaus J.

2008-01-01

Coherent and incoherent electromagnetic radiation emitted from a laser wakefield accelerator is calculated based on Lienard-Wiechert potentials. It is found that at wavelengths longer than the bunch length, the radiation is coherent. The coherent radiation, which typically lies in the infrared

NIOSH (National Institute for Occupational Safety and Health) testimony on radiation before the Senate Committee on Commerce, Science, and Transportation, by Elliot Harris, June 28, 1977

International Nuclear Information System (INIS)

1977-01-01

The statement concerned National Institute for Occupational Safety and Health (NIOSH) research programs relating to occupational exposure to radiation. Much epidemiological data points to exposure to radon daughters as hazards to uranium miners and milling operators. Problems also arise from the operation of radiation-generating equipment. Nonionizing radiation hazards included visible, ultraviolet, radiofrequency and microwave radiation, infrared and ultrasonic radiation. Ultraviolet radiation can cause sunburn, eye damage, depigmentation, precancerous tumors, basal and squamous cell cancers, and malignant melanomas. Infrared radiation has been implicated in the development of cataracts. Laser radiation was linked with burns and fire hazards. The only hazard associated with visible radiation thus far has been eyestrain due to the lack of sufficient light while performing a given task. Optical radiation exposures occurred among workers using cathode ray tubes, such as computer screens, in their jobs. Workers were exposed to many sources of microwave and radiofrequency radiation from radio and radar transmitters, industrial drying equipment, heat sealing and curing equipment, and certain medical research devices. Training and support services were mentioned

Dual-wavelength electroluminescence from an n-ZnO/p-GaN heterojunction light emitting diode

International Nuclear Information System (INIS)

Tsai, Bor-Sheng; Chiu, Hung-Jen; Chen, Tai-Hong; Lai, Li-Wen; Ho, Chai-Cheng; Liu, Day-Shan

2015-01-01

Highlights: • The LEDs fabricated by 450 °C- and 700 °C-annealed n-ZnO/p-GaN heterojunction structures were investigated. • The structure annealed at 700 °C emitted yellowish light composed of the dual-wavelength radiations centered at 420 and 610 nm. • The long-wavelength radiation was attributed to emerge from the deep-level emission and the Ga–O interlayer emission. - Abstract: We investigated the electro-optical properties of light emitting diodes (LEDs) fabricated by using the n-ZnO/p-GaN heterojunction structures annealed at 450 °C and 700 °C, in vacuum ambient. A dominant near-UV emission at approximately 420 nm was observed from the LED fabricated by the 450 °C-annealed n-ZnO/p-GaN heterojunction structure, whereas that of the structure annealed at 700 °C emitted a yellowish light composed of the dual-wavelength emissions centered at 420 and 610 nm. The mechanism responsible for the broad long-wavelength radiation was ascribed to the transitions associated with both the deep-level emissions due to the activation of the native defects on the n-ZnO side surface and the formation of the Ga–O interlayer resulting from the in-diffusion of oxygen atoms to the p-GaN side surface of the n-ZnO/p-GaN interface.

Ultrasound-guided radiofrequency ablation of thyroid gland: a preliminary study in dogs

International Nuclear Information System (INIS)

Choi, Ji Won; Yoo, Seung Min; Kwak, Seo Hyun

2005-01-01

The purpose of this study was to evaluate the possibility of using radiofrequency ablation as the treatment modality for the benign or malignant thyroid nodules in humans. Therefore, we examined the results of using radiofrequency ablation on the thyroid glands in dogs, in respect of the extent of the ablated tissue and the complications. Five dogs (10 lobes of the thyroid glands) were included in this study. US-guided radiofrequency ablation was undertaken with a 10 mm, uncovered 17 gauge cool-tip needle. The power and duration was 20 wattage and 1 minute in five thyroid lobes (group 1) and 20 wattage and 2 minutes in another 5 thyroid lobes (group 2). The ultrasound scans and the pre-and post-enhancement CT scans were undertaken before and immediately after the procedures, and at 24 hours, 72 hours and 1 week later. The US and CT findings of the ablated tissue and complications were evaluated. Blood sampling was done at the pre-procedure time and 1 week later for evaluating the functional status of the thyroid gland. Laryngoscopy was done at the pre-procedure and post-procedure times, and at 24 hours, 72 hours and 1 week later for the evaluation of any recurrent laryngeal nerve palsy. The echo pattern of the ablated thyroid gland at immediately after the radiofrequency ablation appeared as poorly marginated and hyperechoic. On the US obtained 24 hours after radiofrequency ablation, the echo pattern of the ablated thyroid gland was hypoechoic. The maximum diameters after RFA were 9.4 ρ 0.5 mm in group I and 11.4 ρ 0.5 mm in group II. The pre-enhanced CT scan taken at immediately after the radiofrequency ablation showed ill defined hypodense areas in the ablated thyroid gland. Differentiation between the normal and abnormal portions of the thyroid gland was difficult on the contrast enhanced CT scan. Complications induced by radiofrequency ablation were one recurrent laryngeal nerve palsy, two perforations of esophagus and five thickenings of the esophageal wall

Ultrasound-guided radiofrequency ablation of thyroid gland: a preliminary study in dogs

Energy Technology Data Exchange (ETDEWEB)

Choi, Ji Won; Yoo, Seung Min [College of Medicine, Chungang University, Seoul, (Korea, Republic of); Kwak, Seo Hyun [Seoul Veterans Hospital, Seoul (Korea, Republic of)

2005-07-15

The purpose of this study was to evaluate the possibility of using radiofrequency ablation as the treatment modality for the benign or malignant thyroid nodules in humans. Therefore, we examined the results of using radiofrequency ablation on the thyroid glands in dogs, in respect of the extent of the ablated tissue and the complications. Five dogs (10 lobes of the thyroid glands) were included in this study. US-guided radiofrequency ablation was undertaken with a 10 mm, uncovered 17 gauge cool-tip needle. The power and duration was 20 wattage and 1 minute in five thyroid lobes (group 1) and 20 wattage and 2 minutes in another 5 thyroid lobes (group 2). The ultrasound scans and the pre-and post-enhancement CT scans were undertaken before and immediately after the procedures, and at 24 hours, 72 hours and 1 week later. The US and CT findings of the ablated tissue and complications were evaluated. Blood sampling was done at the pre-procedure time and 1 week later for evaluating the functional status of the thyroid gland. Laryngoscopy was done at the pre-procedure and post-procedure times, and at 24 hours, 72 hours and 1 week later for the evaluation of any recurrent laryngeal nerve palsy. The echo pattern of the ablated thyroid gland at immediately after the radiofrequency ablation appeared as poorly marginated and hyperechoic. On the US obtained 24 hours after radiofrequency ablation, the echo pattern of the ablated thyroid gland was hypoechoic. The maximum diameters after RFA were 9.4 {rho} 0.5 mm in group I and 11.4 {rho} 0.5 mm in group II. The pre-enhanced CT scan taken at immediately after the radiofrequency ablation showed ill defined hypodense areas in the ablated thyroid gland. Differentiation between the normal and abnormal portions of the thyroid gland was difficult on the contrast enhanced CT scan. Complications induced by radiofrequency ablation were one recurrent laryngeal nerve palsy, two perforations of esophagus and five thickenings of the esophageal

High radiofrequency radiation at Stockholm Old Town: An exposimeter study including the Royal Castle, Supreme Court, three major squares and the Swedish Parliament

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Koppel, Tarmo; Hedendahl, Lena

2017-01-01

Exposure to radiofrequency (RF) radiation was classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO in 2011. The exposure pattern is changing due to the rapid development of technology. Outdoor RF radiation level was measured during five tours in Stockholm Old Town in April, 2016 using the EME Spy 200 exposimeter with 20 predefined frequencies. The results were based on 10,437 samples in total. The mean level of the total RF radiation was 4,293 µW/m2 (0.4293 µW/cm2). The highest mean levels were obtained for global system for mobile communications (GSM) + universal mobile telecommunications system (UMTS) 900 downlink and long-term evolution (LTE) 2600 downlink (1,558 and 1,265 µW/m2, respectively). The town squares displayed highest total mean levels, with the example of Järntorget square with 24,277 µW/m2 (min 257, max 173,302 µW/m2). These results were in large contrast to areas with lowest total exposure, such as the Supreme Court, with a mean level of 404 µW/m2 (min 20.4, max 4,088 µW/m2). In addition, measurements in the streets surrounding the Royal Castle were lower than the total for the Old Town, with a mean of 756 µW/m2 (min 0.3, max 50,967 µW/m2). The BioInitiative 2012 Report defined the scientific benchmark for possible health risks as 30–60 µW/m2. Our results of outdoor RF radiation exposure at Stockholm Old Town are significantly above that level. The mean exposure level at Järntorget square was 405-fold higher than 60 µW/m2. Our results were below the reference level on 10,000,000 µW/m2 established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), which, however, are less credible, as they do not take non-thermal effects into consideration and are not based on sound scientific evaluation. Our highest measured mean level at Järntorget was 0.24% of the ICNIRP level. A number of studies have found adverse, non-thermal (no measurable temperature

High radiofrequency radiation at Stockholm Old Town: An exposimeter study including the Royal Castle, Supreme Court, three major squares and the Swedish Parliament.

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Koppel, Tarmo; Hedendahl, Lena

2017-04-01

Exposure to radiofrequency (RF) radiation was classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO in 2011. The exposure pattern is changing due to the rapid development of technology. Outdoor RF radiation level was measured during five tours in Stockholm Old Town in April, 2016 using the EME Spy 200 exposimeter with 20 predefined frequencies. The results were based on 10,437 samples in total. The mean level of the total RF radiation was 4,293 µW/m 2 (0.4293 µW/cm 2 ). The highest mean levels were obtained for global system for mobile communications (GSM) + universal mobile telecommunications system (UMTS) 900 downlink and long-term evolution (LTE) 2600 downlink (1,558 and 1,265 µW/m 2 , respectively). The town squares displayed highest total mean levels, with the example of Järntorget square with 24,277 µW/m 2 (min 257, max 173,302 µW/m 2 ). These results were in large contrast to areas with lowest total exposure, such as the Supreme Court, with a mean level of 404 µW/m 2 (min 20.4, max 4,088 µW/m 2 ). In addition, measurements in the streets surrounding the Royal Castle were lower than the total for the Old Town, with a mean of 756 µW/m 2 (min 0.3, max 50,967 µW/m 2 ). The BioInitiative 2012 Report defined the scientific benchmark for possible health risks as 30-60 µW/m 2 . Our results of outdoor RF radiation exposure at Stockholm Old Town are significantly above that level. The mean exposure level at Järntorget square was 405-fold higher than 60 µW/m 2 . Our results were below the reference level on 10,000,000 µW/m 2 established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), which, however, are less credible, as they do not take non-thermal effects into consideration and are not based on sound scientific evaluation. Our highest measured mean level at Järntorget was 0.24% of the ICNIRP level. A number of studies have found adverse, non-thermal (no measurable

InP/ZnS nanocrystals for colour conversion in white light emitting diodes

DEFF Research Database (Denmark)

Shirazi, Roza

In this work a comprehensive study of a colloidal InP/ZnS nanocrystals (NC) as the colour conversion material for white light emitting diodes (WLED) is shown. Studied nanocrystals were synthesised by wet chemistry using one pot, hot injection method. A quantum efficiency (QE) of photoluminescence......, radiative and non-radiative recombination rates were determined and QE of 63% for the population of NCs that emit light was derived. A search for source of exciton losses in bright nanocrystals temperature resolved TRPL was studied and it revealed carrier trapping most likely at core-shell interface as well...... as at the surface and which competes with bright and dark exciton states. A presence of long-lived dark excitons and trapped charges lead to strong Auger recombination at high (relative to the trapping times) excitation. A colour conversion efficiency of the nanocrystals upon light absorption and in a process...

Volatiles emitted from flowers of gamma-radiated and nonradiated Jasminum polyanthum Franch

DEFF Research Database (Denmark)

Christensen, Lars P; Jakobsen, Henrik B; Kristiansen, Kell

1997-01-01

Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%),...

Stepwise radiofrequency ablation of Barrett's esophagus preserves esophageal inner diameter, compliance, and motility

NARCIS (Netherlands)

Beaumont, H.; Gondrie, J. J.; McMahon, B. P.; Pouw, R. E.; Gregersen, H.; Bergman, J. J.; Boeckxstaens, G. E.

2009-01-01

Background and aim: Stepwise endoscopic circumferential and focal radiofrequency ablation is safe and effective for the eradication of Barrett's esophagus. In contrast to other techniques, radiofrequency ablation appears to avoid significant esophageal scarring or stenosis. Our aim was to evaluate

Electromagnetic radiation of electrons in periodic structures

International Nuclear Information System (INIS)

Potylitsyn, Alexander Petrovich

2011-01-01

Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation and the Smith-Purcell effect. Characteristics of such radiation sources and perspectives of their usage are discussed. The recent experimental results as well as their interpretation are presented. (orig.)

Superconducting Radio-Frequency Cavities

Science.gov (United States)

Padamsee, Hasan S.

2014-10-01

Superconducting cavities have been operating routinely in a variety of accelerators with a range of demanding applications. With the success of completed projects, niobium cavities have become an enabling technology, offering upgrade paths for existing facilities and pushing frontier accelerators for nuclear physics, high-energy physics, materials science, and the life sciences. With continued progress in basic understanding of radio-frequency superconductivity, the performance of cavities has steadily improved to approach theoretical capabilities.

Influence of radiofrequency surgery on architecture of the palatine tonsils.