WorldWideScience

Sample records for radiofrequency radiation emitted

  1. Evaluation of stray radiofrequency radiation emitted by electrosurgical devices.

    Science.gov (United States)

    De Marco, M; Maggi, S

    2006-07-21

    Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m(-1) (E-field 400 V m(-1)). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy.

  2. Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

    Science.gov (United States)

    DeMarco, M.; Maggi, S.

    2006-07-01

    Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m-1 (E-field 400 V m-1). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy.

  3. Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

    Energy Technology Data Exchange (ETDEWEB)

    De Marco, M; Maggi, S [Department of Medical Physics, Ospedali Riuniti di Ancona, Ancona, 60021 (Italy)

    2006-07-21

    Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m{sup -1} (E-field 400 V m{sup -1}). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy.

  4. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors.

    Science.gov (United States)

    Mortazavi, Smj; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, Ar

    2014-09-01

    Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors.

  5. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    Directory of Open Access Journals (Sweden)

    SMJ Mortazavi

    2013-01-01

    Full Text Available Background: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs. Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. Aims: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF radiations emitted by common mobile jammers. Subjects and Methods: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. Statistical Analysis: T-test and analysis of variance were used to show statistical significance. Results: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples′ chances of conception. Conclusion: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places.

  6. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study

    Directory of Open Access Journals (Sweden)

    Rafati A.

    2015-09-01

    Full Text Available Introduction: The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog’s isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz. Materials and Methods: Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF radiation emitted from a common Jammer at a distance of 1m from the jammer’s antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T, the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz as stimuli. Results: The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, 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.

  7. 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

  8. Effect of long-term exposure of 2.4 GHz radiofrequency radiation emitted from Wi-Fi equipment on testes functions.

    Science.gov (United States)

    Dasdag, Suleyman; Taş, Muzaffer; Akdag, Mehmet Zulkuf; Yegin, Korkut

    2015-03-01

    The aim of this study was to investigate long-term effects of radiofrequency radiation (RFR) emitted from a Wireless Fidelity (Wi-Fi) system on testes. The study was carried out on 16 Wistar Albino adult male rats by dividing them into two groups such as sham (n: 8) and exposure (n: 8). Rats in the exposure group were exposed to 2.4 GHz RFR radiation for 24 h/d during 12 months (1 year). The same procedure was applied to the rats in the sham control group except the Wi-Fi system was turned off. Immediately after the last exposure, rats were sacrificed and reproductive organs were removed. Motility (%), concentration (×10(6)/mL), tail defects (%), head defects (%) and total morphologic defects (%) of sperms and weight of testes (g), left epididymis (g), prostate (g), seminal vesicles (g) were determined. Seminiferous tubules diameter (μm) and tunica albuginea thickness (μm) were also measured. However, the results were evaluated by using Johnsen's score. Head defects increased in the exposure group (p  0.05). In conclusion, we observed that long-term exposure of 2.4 GHz RF emitted from Wi-Fi (2420 μW/kg, 1 g average) affects some of the reproductive parameters of male rats. We suggest Wi-Fi users to avoid long-term exposure of RF emissions from Wi-Fi equipment.

  9. Does prolonged radiofrequency radiation emitted from Wi-Fi devices induce DNA damage in various tissues of rats?

    Science.gov (United States)

    Akdag, Mehmet Zulkuf; Dasdag, Suleyman; Canturk, Fazile; Karabulut, Derya; Caner, Yusuf; Adalier, Nur

    2016-09-01

    Wireless internet (Wi-Fi) providers have become essential in our daily lives, as wireless technology is evolving at a dizzying pace. Although there are different frequency generators, one of the most commonly used Wi-Fi devices are 2.4GHz frequency generators. These devices are heavily used in all areas of life but the effect of radiofrequency (RF) radiation emission on users is generally ignored. Yet, an increasing share of the public expresses concern on this issue. Therefore, this study intends to respond to the growing public concern. The purpose of this study is to reveal whether long term exposure of 2.4GHz frequency RF radiation will cause DNA damage of different tissues such as brain, kidney, liver, and skin tissue and testicular tissues of rats. The study was conducted on 16 adult male Wistar-Albino rats. The rats in the experimental group (n=8) were exposed to 2.4GHz frequency radiation for over a year. The rats in the sham control group (n=8) were subjected to the same experimental conditions except the Wi-Fi generator was turned off. After the exposure period was complete the possible DNA damage on the rat's brain, liver, kidney, skin, and testicular tissues was detected through the single cell gel electrophoresis assay (comet) method. The amount of DNA damage was measured as percentage tail DNA value. Based on the DNA damage results determined by the single cell gel electrophoresis (Comet) method, it was found that the% tail DNA values of the brain, kidney, liver, and skin tissues of the rats in the experimental group increased more than those in the control group. The increase of the DNA damage in all tissues was not significant (p>0.05). However the increase of the DNA damage in rat testes tissue was significant (pWi-Fi) does not cause DNA damage of the organs investigated in this study except testes. The results of this study indicated that testes are more sensitive organ to RF radiation.

  10. Long-term effects of 900 MHz radiofrequency radiation emitted from mobile phone on testicular tissue and epididymal semen quality.

    Science.gov (United States)

    Tas, Muzaffer; Dasdag, Suleyman; Akdag, Mehmet Zulkuf; Cirit, Umut; Yegin, Korkut; Seker, Ugur; Ozmen, Mehmet Ferit; Eren, Leyla Bilge

    2014-09-01

    The purpose of this study is to bridge this gap by investigating effects of long term 900 MHz mobile phone exposure on reproductive organs of male rats. The study was carried out on 14 adult Wistar Albino rats by dividing them randomly into two groups (n: 7) as sham group and exposure group. Rats were exposed to 900 MHz radiofrequency (RF) radiation emitted from a GSM signal generator. Point, 1 g and 10 g specific absorption rate (SAR) levels of testis and prostate were found as 0.0623 W/kg, 0.0445 W/kg and 0.0373 W/kg, respectively. The rats in the exposure group were subject to RF radiation 3 h per day (7 d a week) for one year. For the sham group, the same procedure was applied, except the generator was turned off. At the end of the study, epididymal sperm concentration, progressive sperm motility, abnormal sperm rate, all-genital organs weights and testis histopathology were evaluated. Any differences were not observed in sperm motility and concentration (p > 0.05). However, the morphologically normal spermatozoa rates were found higher in the exposure group (p radiation alter some reproductive parameters. However, more supporting evidence and research is definitely needed on this topic.

  11. Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli.

    Science.gov (United States)

    Taheri, M; Mortazavi, S M J; Moradi, M; Mansouri, S; Hatam, G R; Nouri, F

    2017-01-01

    Mobile phones and Wi-Fi radiofrequency radiation are among the main sources of the exposure of the general population to radiofrequency electromagnetic fields (RF-EMF). Previous studies have shown that exposure of microorganisms to RF-EMFs can be associated with a wide spectrum of changes ranged from the modified bacterial growth to the alterations of the pattern of antibiotic resistance. Our laboratory at the nonionizing department of the Ionizing and Non-ionizing Radiation Protection Research Center has performed experiments on the health effects of exposure to animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons, magnetic resonance imaging, and Helmholtz coils. On the other hand, we have previously studied different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. In this study, we assessed if the exposure to 900 MHz GSM mobile phone radiation and 2.4 GHz radiofrequency radiation emitted from common Wi-Fi routers alters the susceptibility of microorganisms to different antibiotics. The pure cultures of Listeria monocytogenes and Escherichia coli were exposed to RF-EMFs generated either by a GSM 900 MHz mobile phone simulator and a common 2.4 GHz Wi-Fi router. It is also shown that exposure to RF-EMFs within a narrow level of irradiation (an exposure window) makes microorganisms resistant to antibiotics. This adaptive phenomenon and its potential threats to human health should be further investigated in future experiments. Altogether, the findings of this study showed that exposure to Wi-Fi and RF simulator radiation can significantly alter the inhibition zone diameters and growth rate for L monocytogenes and E coli. These findings may have implications for the management of serious infectious diseases.

  12. Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli

    Science.gov (United States)

    Taheri, M.; Mansouri, S.; Hatam, G. R.; Nouri, F.

    2017-01-01

    Mobile phones and Wi-Fi radiofrequency radiation are among the main sources of the exposure of the general population to radiofrequency electromagnetic fields (RF-EMF). Previous studies have shown that exposure of microorganisms to RF-EMFs can be associated with a wide spectrum of changes ranged from the modified bacterial growth to the alterations of the pattern of antibiotic resistance. Our laboratory at the nonionizing department of the Ionizing and Non-ionizing Radiation Protection Research Center has performed experiments on the health effects of exposure to animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons, magnetic resonance imaging, and Helmholtz coils. On the other hand, we have previously studied different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. In this study, we assessed if the exposure to 900 MHz GSM mobile phone radiation and 2.4 GHz radiofrequency radiation emitted from common Wi-Fi routers alters the susceptibility of microorganisms to different antibiotics. The pure cultures of Listeria monocytogenes and Escherichia coli were exposed to RF-EMFs generated either by a GSM 900 MHz mobile phone simulator and a common 2.4 GHz Wi-Fi router. It is also shown that exposure to RF-EMFs within a narrow level of irradiation (an exposure window) makes microorganisms resistant to antibiotics. This adaptive phenomenon and its potential threats to human health should be further investigated in future experiments. Altogether, the findings of this study showed that exposure to Wi-Fi and RF simulator radiation can significantly alter the inhibition zone diameters and growth rate for L monocytogenes and E coli. These findings may have implications for the management of serious infectious diseases. PMID:28203122

  13. Genetic damage in subjects exposed to radiofrequency radiation.

    Science.gov (United States)

    Verschaeve, Luc

    2009-01-01

    Despite many research efforts and public debate there is still great concern about the possible adverse effects of radiofrequency (RF) radiation on human health. This is especially due to the enormous increase of wireless mobile telephones and other telecommunication devices throughout the world. The possible genetic effects of mobile phone radiation and other sources of radiofrequencies constitute one of the major points of concern. In the past several review papers were published on laboratory investigations that were devoted to in vitro and in vivo animal (cyto)genetic studies. However, it may be assumed that some of the most important observations are those obtained from studies with individuals that were exposed to relatively high levels of radiofrequency radiation, either as a result of their occupational activity or as frequent users of radiofrequency emitting tools. In this paper the cytogenetic biomonitoring studies of RF-exposed humans are reviewed. A majority of these studies do show that RF-exposed individuals have increased frequencies of genetic damage (e.g., chromosomal aberrations) in their lymphocytes or exfoliated buccal cells. However, most of the studies, if not all, have a number of shortcomings that actually prevents any firm conclusion. Radiation dosimetry was lacking in all papers, but some of the investigations were flawed by much more severe imperfections. Large well-coordinated multidisciplinary investigations are needed in order to reach any robust conclusion.

  14. Radiofrequency and microwave radiation in the microelectronics industry.

    Science.gov (United States)

    Cohen, R

    1986-01-01

    The microscopic precision required to produce minute integrated circuits is dependent on several processes utilizing radiofrequency and microwave radiation. This article provides a review of radiofrequency and microwave exposures in microelectronics and of the physical and biologic properties of these types of radiation; summarizes the existing, relevant medical literature; and provides the clinician with guidelines for diagnosis and treatment of excessive exposures to microwave and radiofrequency radiation.

  15. The link between radiofrequencies emitted from wireless technologies and oxidative stress.

    Science.gov (United States)

    Dasdag, Suleyman; Akdag, Mehmet Zulkuf

    2016-09-01

    Wireless communication such as cellular telephones and other types of handheld phones working with frequencies of 900MHz, 1800MHz, 2100MHz, 2450MHz have been increasing rapidly. Therefore, public opinion concern about the potential human health hazards of short and long-term effect of exposure to radiofrequency (RF) radiation. Oxidative stress is a biochemical condition, which is defined by the imbalance between reactive oxygen species (ROS) and the anti-oxidative defense. In this review, we evaluated available in vitro and in vivo studies carried out on the relation between RF emitted from mobile phones and oxidative stress. The results of the studies we reviewed here indicated that mobile phones and similar equipment or radars can be thought as a factor, which cause oxidative stress. Even some of them claimed that oxidative stress originated from radiofrequencies can be resulted with DNA damage. For this reason one of the points to think on is relation between mobile phones and oxidative stress. However, more performance is necessary especially on human exposure studies.

  16. Radiofrequency radiation leakage from microwave ovens.

    Science.gov (United States)

    Lahham, Adnan; Sharabati, Afifeh

    2013-12-01

    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(-2) 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 mW cm(-2) 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.

  17. Radiofrequency electromagnetic radiation from cell phone causes defective testicular function in male Wistar rats.

    Science.gov (United States)

    Oyewopo, A O; Olaniyi, S K; Oyewopo, C I; Jimoh, A T

    2017-03-06

    Cell phones have become an integral part of everyday life. As cell phone usage has become more widespread, concerns have increased regarding the harmful effects of radiofrequency electromagnetic radiation from these devices. The current study was undertaken to investigate the effects of the emitted radiation by cell phones on testicular histomorphometry and biochemical analyses. Adult male Wistar rats weighing 180-200 g were randomly allotted to control, group A (switched off mode exposure), group B (1-hr exposure), group C (2-hr exposure) and group D (3-hr exposure). The animals were exposed to radiofrequency electromagnetic radiation of cell phone for a period of 28 days. Histomorphometry, biochemical and histological investigations were carried out. The histomorphometric parameters showed no significant change (p radiation of cell phone leads to defective testicular function that is associated with increased oxidative stress and decreased gonadotropic hormonal profile. © 2017 Blackwell Verlag GmbH.

  18. 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...

  19. 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...

  20. 47 CFR 2.1091 - Radiofrequency radiation exposure evaluation: mobile devices.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency radiation exposure evaluation... Procedures Radiofrequency Radiation Exposure § 2.1091 Radiofrequency radiation exposure evaluation: mobile... stations devices only) and part 90 of this chapter are subject to routine environmental evaluation for...

  1. 47 CFR 2.1093 - Radiofrequency radiation exposure evaluation: portable devices.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency radiation exposure evaluation... Procedures Radiofrequency Radiation Exposure § 2.1093 Radiofrequency radiation exposure evaluation: portable.... These criteria for SAR evaluation are similar to those recommended by the National Council on...

  2. Radiotelemetry and wildlife: Highlighting a gap in the knowledge on radiofrequency radiation effects

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-01

    Radio transmitters and associated devices may induce negative effects that can bias the results of ongoing research. The main documented effects of radio transmitters on animals include reduced survival, decreased productivity, changes in behaviour and movement patterns and a biased sex ratio. The only factors that have claimed responsibility for these possible damages are the weight of the radio transmitter and associated devices, and the attachment type. The electromagnetic radiation produced by radio transmitters has not been considered so far in research. There have been no studies evaluating the effects of non-ionising electromagnetic radiation (radiofrequency signals) necessary for tracking, although the problems found were significantly associated with the length of time that animals had been carrying their radio transmitters. Similar problems as those in radiotracked animals have been found in numerous studies with animals exposed to radiofrequency radiation for a sufficient amount of time. Laboratory scientists investigating the orientation of animals know they have to shield the place where experiments are performed to prevent interference from man-made radiation, as anthropogenic signals may distort the results. It is paradoxical that, at the same time, field scientists investigating the movements and other aspects of animal biology are providing animals with radio transmitters that emit the same type of radiation, since this may affect the results concerning their orientation and movement. This paper identifies gaps in the knowledge that should be investigated in-depth. The possibility that the radiofrequency radiation from radiotracking devices is responsible for the findings should be considered. Considering this factor may allow researchers to best understand the long-term effects found. - Highlights: • Radiotracking may induce negative effects that can bias the results. • Effects have been documented on survival, reproduction and behaviour.

  3. 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.

  4. [Instrumental radiofrequency electromagnetic radiation dosimetry: general principals and modern methodology].

    Science.gov (United States)

    Perov, S Iu; Kudriashov, Iu B; Rubtsova, N B

    2012-01-01

    The modern experimental radiofrequency electromagnetic field dosimetry approach has been considered. The main principles of specific absorbed rate measurement are analyzed for electromagnetic field biological effect assessment. The general methodology of specific absorbed rate automated dosimetry system applied to establish the compliance of radiation sources with the safety standard requirements (maximum permissible levels and base restrictions) is described.

  5. 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.

  6. Non-linear adaptive phenomena which decrease the risk of infection after pre-exposure to radiofrequency radiation.

    Science.gov (United States)

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

    2014-05-01

    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 have indicated that pre-exposure of mice to radiofrequency radiation emitted by a GSM mobile phone increased their resistance to a subsequent Escherichia coli infection. In this study, the survival rates in animals receiving both adapting (radiofrequency) and challenge dose (bacteria) and the animals receiving only the challenge dose (bacteria) were 56% and 20%, respectively. In this light, our findings contribute to the assumption that radiofrequency-induced adaptive response can be used as an efficient method for decreasing the risk of infection in immunosuppressed irradiated individuals. The implication of this phenomenon in human's long term stay in the space is also discussed.

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

    OpenAIRE

    Seyed Mohammad Javad Mortazavi; Seyed Ali Reza Mortazavi

    2016-01-01

    ABSTRACT INTRODUCTION: 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. OBJECTIVE: The aim of this study was to evaluate the availabl...

  8. Radiotelemetry and wildlife: Highlighting a gap in the knowledge on radiofrequency radiation effects.

    Science.gov (United States)

    Balmori, Alfonso

    2016-02-01

    Radio transmitters and associated devices may induce negative effects that can bias the results of ongoing research. The main documented effects of radio transmitters on animals include reduced survival, decreased productivity, changes in behaviour and movement patterns and a biased sex ratio. The only factors that have claimed responsibility for these possible damages are the weight of the radio transmitter and associated devices, and the attachment type. The electromagnetic radiation produced by radio transmitters has not been considered so far in research. There have been no studies evaluating the effects of non-ionising electromagnetic radiation (radiofrequency signals) necessary for tracking, although the problems found were significantly associated with the length of time that animals had been carrying their radio transmitters. Similar problems as those in radiotracked animals have been found in numerous studies with animals exposed to radiofrequency radiation for a sufficient amount of time. Laboratory scientists investigating the orientation of animals know they have to shield the place where experiments are performed to prevent interference from man-made radiation, as anthropogenic signals may distort the results. It is paradoxical that, at the same time, field scientists investigating the movements and other aspects of animal biology are providing animals with radio transmitters that emit the same type of radiation, since this may affect the results concerning their orientation and movement. This paper identifies gaps in the knowledge that should be investigated in-depth. The possibility that the radiofrequency radiation from radiotracking devices is responsible for the findings should be considered. Considering this factor may allow researchers to best understand the long-term effects found.

  9. HF radiation emitted by chaotic leader processes

    Science.gov (United States)

    Mäkelä, J. S.; Edirisinghe, M.; Fernando, M.; Montaño, R.; Cooray, V.

    2007-04-01

    This paper presents direct measurements of narrowband 10 MHz HF radiation from so-called “chaotic leaders” associated with subsequent return strokes. Although the term is controversial and poorly defined, we find that more than 30% of subsequent strokes in close lightning flashes contain electric field characteristics that are best described as “chaotic”. In earlier studies, return strokes have consistently been observed to be the strongest sources of HF radiation, but the results for leader processes are less consistent. We also observe return strokes to be the main HF emitter, and the leaders before the first return stroke in a flash sequence also emit HF though somewhat less intensely. The leaders preceding subsequent strokes typically emit little or no HF radiation, whether they are dart or dart-stepped leaders. However, it was observed that the presence of a chaotic component increases the leader HF intensity dramatically Defining the HF intensity unequivocally can be problematic for processes like chaotic leaders which have a combination of continuous and impulsive phenomena. Two time-domain methods were used to measure the HF intensity, the peak energy and the RMS energy. In the frequency domain these correspond to the energy spectral density (ESD) and power spectral density (PSD), respectively. It was found that the methods are not necessarily compatible. Thus, it is suggested that to clarify future work, leader processes should be characterized by the PSD rather than the ESD.

  10. Effect of radiofrequency radiation in cultured mammalian cells: A review.

    Science.gov (United States)

    Manna, Debashri; Ghosh, Rita

    2016-01-01

    The use of mobile phone related technologies will continue to increase in the foreseeable future worldwide. This has drawn attention to the probable interaction of radiofrequency electromagnetic radiation with different biological targets. Studies have been conducted on various organisms to evaluate the alleged ill-effect on health. We have therefore attempted to review those work limited to in vitro cultured cells where irradiation conditions were well controlled. Different investigators have studied varied endpoints like DNA damage, cell cycle arrest, reactive oxygen species (ROS) formation, cellular morphology and viability to weigh the genotoxic effect of such radiation by utilizing different frequencies and dose rates under various irradiation conditions that include continuous or pulsed exposures and also amplitude- or frequency-modulated waves. Cells adapt to change in their intra and extracellular environment from different chemical and physical stimuli through organized alterations in gene or protein expression that result in the induction of stress responses. Many studies have focused on such effects for risk estimations. Though the effects of microwave radiation on cells are often not pronounced, some investigators have therefore combined radiofrequency radiation with other physical or chemical agents to observe whether the effects of such agents were augmented or not. Such reports in cultured cellular systems have also included in this review. The findings from different workers have revealed that, effects were dependent on cell type and the endpoint selection. However, contradictory findings were also observed in same cell types with same assay, in such cases the specific absorption rate (SAR) values were significant.

  11. Risk assessment and management of radiofrequency radiation exposure

    Science.gov (United States)

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

    2013-11-01

    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.

  12. 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.

  13. SUMER: Solar Ultraviolet Measurements of Emitted Radiation

    Science.gov (United States)

    Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber, M. C. E.; Jordan, M. C. E.; Lemaire, P.; Marsch, E.; Poland, A. I.

    1988-01-01

    The SUMER (solar ultraviolet measurements of emitted radiation) experiment is described. It will study flows, turbulent motions, waves, temperatures and densities of the plasma in the upper atmosphere of the Sun. Structures and events associated with solar magnetic activity will be observed on various spatial and temporal scales. This will contribute to the understanding of coronal heating processes and the solar wind expansion. The instrument will take images of the Sun in EUV (extreme ultra violet) light with high resolution in space, wavelength and time. The spatial resolution and spectral resolving power of the instrument are described. Spectral shifts can be determined with subpixel accuracy. The wavelength range extends from 500 to 1600 angstroms. The integration time can be as short as one second. Line profiles, shifts and broadenings are studied. Ratios of temperature and density sensitive EUV emission lines are established.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Interaction of Ionizing Radiation, Genetically Active Chemicals, and Radiofrequency Radiation in Human and Rodent Cells

    Science.gov (United States)

    1990-12-01

    Martin L. Meltz, Ph.D. Patricia K. Holahan , Ph.D. Steven T. Smith, Ph.D. James J. Kerbacher, Ph.D. Victor Ciaravino, Ph.D. Department of Radiology PO...Chemicals, and Radiofrequency Radiation in Human and Rodent Cells 12 PERSONAL AUTHOR(S) Meltz. Martin L.; Holahan Patricia K.; Smith Steven Kerbacher...Potentiation of SCE Induction and Cell Killing by Adriamycin in CHO Cells (Ciaravino and Holahan , in preparation), showed that Adriamycin exposure at 410C

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

    Directory of Open Access Journals (Sweden)

    Luisa Nascimento Medeiros

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: 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. OBJECTIVE: The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. METHODS: 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. RESULTS: 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. CONCLUSION: There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus.

  20. Short-duration exposure to radiofrequency electromagnetic radiation alters the chlorophyll fluorescence of duckweeds (Lemna minor).

    Science.gov (United States)

    Senavirathna, Mudalige Don Hiranya Jayasanka; Takashi, Asaeda; Kimura, Yuichi

    2014-12-01

    Plants growing in natural environments are exposed to radiofrequency electromagnetic radiation (EMR) emitted by various communication network base stations. The environmental concentration of this radiation is increasing rapidly with the congested deployment of base stations. Although numerous scientific studies have been conducted to investigate the effects of EMR on the physiology of humans and animals, there have been few attempts to investigate the effects of EMR on plants. In this study, we attempted to evaluate the effects of EMR on photosynthesis by investigating the chlorophyll fluorescence (ChF) parameters of duckweed fronds. During the experiment, the fronds were tested with 2, 2.5, 3.5, 5.5 and 8 GHz EMR frequencies, which are not widely studied even though there is a potentially large concentration of these frequencies in the environment. The duckweed fronds were exposed to EMR for 30 min, 1 h and 24 h durations with electric field strength of 45-50 V/m for each frequency. The results indicated that exposure to EMR causes a change in the non-photochemical quenching of the duckweeds. The changes varied with the frequency of the EMR and were time-varying within a particular frequency. The temperature remained unchanged in the duckweed fronds upon exposure to EMR, which confirms that the effect is non-thermal.

  1. Cytogenetic studies in human cells exposed in vitro to GSM-900 MHz radiofrequency radiation using R-banded karyotyping.

    Science.gov (United States)

    Bourthoumieu, S; Joubert, V; Marin, B; Collin, A; Leveque, P; Terro, F; Yardin, C

    2010-12-01

    It is important to determine the possible effects of exposure to radiofrequency (RF) radiation on the genetic material of cells since damage to the DNA of somatic cells may be linked to cancer development or cell death and damage to germ cells may lead to genetic damage in next and subsequent generations. The objective of this study was to investigate whether exposure to radiofrequency radiation similar to that emitted by mobile phones of second-generation standard Global System for Mobile Communication (GSM) induces genotoxic effects in cultured human cells. The cytogenetic effects of GSM-900 MHz (GSM-900) RF radiation were investigated using R-banded karyotyping after in vitro exposure of human cells (amniotic cells) for 24 h. The average specific absorption rate (SAR) was 0.25 W/kg. The exposures were carried out in wire-patch cells (WPCs) under strictly controlled conditions of temperature. The genotoxic effect was assessed immediately or 24 h after exposure using four different samples. One hundred metaphase cells were analyzed per assay. Positive controls were provided by using bleomycin. We found no direct cytogenetic effects of GSM-900 either 0 h or 24 h after exposure. To the best of our knowledge, our work is the first to study genotoxicity using complete R-banded karyotyping, which allows visualizing all the chromosomal rearrangements, either numerical or structural.

  2. Radiation emitted by transverse-gradient undulators

    Science.gov (United States)

    Bernhard, Axel; Braun, Nils; Rodríguez, Verónica Afonso; Peiffer, Peter; Rossmanith, Robert; Widmann, Christina; Scheer, Michael

    2016-09-01

    Conventional undulators are used in synchrotron light sources to produce radiation with a narrow relative spectral width as compared to bending magnets or wigglers. The spectral width of the radiation produced by conventional undulators is determined by the number of undulator periods and by the energy spread and emittance of the electron beam. In more compact electron sources like for instance laser plasma accelerators the energy spread becomes the dominating factor. Due to this effect these electron sources cannot in general be used for high-gain free electron lasers (FELs). In order to overcome this limitation, modified undulator schemes, so-called transverse gradient undulators (TGUs), were proposed and a first superconducting TGU was built at Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. In this paper simulations of the expected synchrotron radiation spectral distribution are presented. An experimental test with that device is under preparation at the laser wakefield accelerator at the JETI laser at the University of Jena, Germany.

  3. 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.

  4. Cognitive effects of cellular phones: a possible role of non-radiofrequency radiation factors.

    Science.gov (United States)

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

    2011-10-01

    Some studies found that cognitive functions of human beings may be altered while exposed to radiofrequency radiation (RFR) emitted by cellular phones. In two recent studies, we have found that experiment duration and exposure side (i.e., phone's location--right or left) may have a major influence on the detection of such effects. In this brief follow-up experiment, 29 right-handed male subjects were divided into two groups. Each subject had two standard cellular phones attached to both sides of his head. The subjects performed a spatial working memory task that required either a left-hand or a right-hand response under one of the two exposure conditions: left side of the head or right side. Contrary to our previous studies, in this work external antennas located far away from the subjects were connected to the cellular phones. This setup prevents any emission of RFR from the internal antenna, thus drastically reducing RFR exposure. Despite that, the results remain similar to those obtained in our previous work. These results indicate that some of the effects previously attributed to RFR can be the result of some confounders. Copyright © 2011 Wiley-Liss, Inc.

  5. [The assessment of modulated radiofrequence electromagnetic radiation on cognitive function in rats of different ages].

    Science.gov (United States)

    Priakhin, E A; Triapitsyna, G A; Andreev, S S; Kolomiets, I A; Polevik, N D; Akleev, A V

    2007-01-01

    The modulated radiofrequence electromagnetic radiation influence on cognitive function of male uninbred Wister rat exposed at the age of sexual maturation (2 months) and at the age of morphofunctional maturity (3.5 months) was examined. Animals were subjected to pulse electromagnetic radiation (925 MHz) modulated as a GSM standard with the power density 1.2 mW/cm2 for 10 minutes every day for 12 days. At day 8 of exposure the cognitive function were examined with the Morris water maze. In the result of investigation it was determines that modulated radiofrequence electromagnetic radiation at the sexual maturation age did not affect the spatial learning and improve the visual orientation performance. Modulated radiofrequence electromagnetic exposure of animals at the sex maturity age did not affect the visual performance and improve the spatial performance of male rats.

  6. 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.

  7. Radiation emitted by transverse-gradient undulators

    Directory of Open Access Journals (Sweden)

    Axel Bernhard

    2016-09-01

    Full Text Available Conventional undulators are used in synchrotron light sources to produce radiation with a narrow relative spectral width as compared to bending magnets or wigglers. The spectral width of the radiation produced by conventional undulators is determined by the number of undulator periods and by the energy spread and emittance of the electron beam. In more compact electron sources like for instance laser plasma accelerators the energy spread becomes the dominating factor. Due to this effect these electron sources cannot in general be used for high-gain free electron lasers (FELs. In order to overcome this limitation, modified undulator schemes, so-called transverse gradient undulators (TGUs, were proposed and a first superconducting TGU was built at Karlsruhe Institute of Technology (KIT, Karlsruhe, Germany. In this paper simulations of the expected synchrotron radiation spectral distribution are presented. An experimental test with that device is under preparation at the laser wakefield accelerator at the JETI laser at the University of Jena, Germany.

  8. Effect of Radiofrequency Radiation on DNA Duplex Stability and Replication.

    Science.gov (United States)

    1983-08-01

    R.W., J.B. Dodgson, I.F. Nes, and R.D. Wells. Duplex regions in single-stranded OX174 DNA are cleaved by a restriction endonuclease from Haemophilus ... aegyptius . J Biol Chem 252:7300-7306 (1977). *i Brown, R.F., S.V. Marshall, and C.W. Hughes. Effect of radiofrequency radi- ation (RFR) on excision

  9. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Science.gov (United States)

    2010-10-01

    ... Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz,” ANSI... Criteria for Radiofrequency Electromagnetic Fields,” NCRP Report No. 86, Sections 17.4.1, 17.4.1.1, 17.4.2... 1500 MHz, exposure limits for field strength and power density are also generally based on...

  10. 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).

  11. 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 plants seem to be very sensitive to RF-EMFs. Our findings also suggest that plants seem to be more responsive to certain frequencies, especially the frequencies between (i) 800 and 1500 MHz (p plants to date observed the significant trend of 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.

  12. Anticancer effects on leiomyosarcoma-bearing Wistar rats after electromagnetic radiation of resonant radiofrequencies.

    Science.gov (United States)

    Avdikos, Antonios; Karkabounas, Spyridon; Metsios, Apostolos; Kostoula, Olga; Havelas, Konstantinos; Binolis, Jayne; Verginadis, Ioannis; Hatziaivazis, George; Simos, Ioannis; Evangelou, Angelos

    2007-01-01

    In the present study, the effects of a resonant low intensity static electromagnetic field (EMF), causing no thermal effects, on Wistar rats have been investigated. Sarcoma cell lines were isolated from leiomyosarcoma tumors induced in Wistar rats by the subcutaneous (s.c) injection of 3,4-benzopyrene. Furthermore, smooth muscle cells (SMC) were isolated from the aorta of Wistar rats and cultivated. Either leiomyosarcoma cells (LSC) or SMC were used to record a number of characteristic resonant radiofrequencies, in order to determine the specific electromagnetic fingerprint spectrum for each cell line. These spectra were used to compose an appropriate algorithm, which transforms the recorded radiofrequencies to emitted ones. The isolated LSC were cultured and then exposed to a resonant low intensity radiofrequency EMF (RF-EMF), at frequencies between 10 kHz to 120 kHz of the radiowave spectrum. The exposure lasted 45 consecutive minutes daily, for two consecutive days. Three months old female Wistar rats were inoculated with exposed and non-exposed to EMF LSC (4 x 10(6) LCS for animal). Inoculated with non-exposed to EMF cells animals were then randomly separated into three Groups. The first Group was sham exposed to the resonant EMF (control Group-CG), the second Group after the inoculation of LSC and appearance of a palpable tumor mass, was exposed to a non-resonant EMF radiation pattern, for 5 h per day till death of all animals (experimental control Group-ECG). The third Group of animals after inoculation of LSC and the appearance of a palpable tumor mass, was exposed to the resonant EMF radiation for 5 h per day, for a maximum of 60 days (experimental Group-I, EG-I). A fourth Group of animals was inoculated with LSC exposed to EMF irradiation and were not further exposed to irradiation (experimental Group-II, EG-II). Tumor induction was 100% in all Groups studied and all tumors were histologically identified as leiomyosarcomas. In the case of the EG-I, a

  13. 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.

  14. Non-radiative and radiative decays in nanogap emitting devices

    CERN Document Server

    Faggiani, Remi; Lalanne, Philippe

    2015-01-01

    By placing a quantum emitter in the mouths of nanogaps consisting of two metal nanoparticles nearly into contact, significant increases in emission rate are obtained. This mechanism is central in the design of modern plasmonic nanoantennas. However, due to the lack of general knowledge on the balance between the different decay rates in nanogaps (emission, quenching, and metal absorption), nanoantenna design is performed in a rather haphazard fashion and relies on repeated numerical calculations; general intuitive design recipes do not presently exist. With accurate and simple closed-form expressions for the quenching rate and the decay rate into gap plasmons, we provide a comprehensive analysis of nanogap light emitting devices in the limit of small gap thickness. We disclose that the total spontaneous emission rate of quantum emitters in nanometer-thin gaps can largely overcome quenching, for specifically selected metallic and insulator materials, regardless of the gap size. Furthermore, to help further des...

  15. 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

  16. Effect of Ultrahigh Frequency Radiation Emitted from 2G Cell Phone on Developing Lens of Chick Embryo: A Histological Study

    Directory of Open Access Journals (Sweden)

    Mary Hydrina D'Silva

    2014-01-01

    Full Text Available A Mobile phone in operation emits a pulsed radiofrequency electromagnetic field which is absorbed into the user’s body particularly the head region. Contradictory scientific reports on the health effect of nonionizing radiations on biological tissues have prompted to undertake the present study to evaluate the damage in the developing lens of a chick embryo following exposure to radiation emitted from a 2G cell phone. Fertilized chick embryos were incubated in two groups in a standard egg incubator. The experiment group was exposed to radiation emitted from a 2G cell phone. On completion of scheduled duration, the embryos were collected and processed for routine histological studies. The 9th to 12th day chick embryo eyes were processed for assessment of DNA damage using the alkaline comet assay technique. The lens thickness and the equatorial diameter were measured using oculometer and statistically compared for both groups. In the present study, the exposure of chick embryos to a 2G cell phone caused structural changes in lens epithelial cells, formation of cystic cells and spaces, distortion of lens fibers, and formation of posterior aberrant nuclear layer. The DNA damage in the developing eyes of the experiment group assessed by comet assay was highly significant.

  17. 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.

  18. Vacuum ultraviolet radiation emitted by microwave driven argon plasmas

    Science.gov (United States)

    Espinho, S.; Felizardo, E.; Henriques, J.; Tatarova, E.

    2017-04-01

    Vacuum ultraviolet (VUV) radiation emitted by microwave driven argon plasmas has been investigated at low-pressure conditions (0.36 mbar). A classical surface-wave sustained discharge at 2.45 GHz has been used as plasma source. VUV radiation has been detected by emission spectroscopy in the 30-125 nm spectral range. The spectrum exhibits atomic and ionic argon emissions with the most intense spectral lines corresponding to the atomic resonance lines, at 104.8 nm and 106.7 nm, and to the ion lines, at 92.0 nm and 93.2 nm. Emissions at lower wavelengths were also detected, including lines with no information concerning level transitions in the well-known NIST database (e.g., the atomic line at 89.4 nm). The dependence of the lines' intensity on the microwave power delivered to the launcher was investigated. The electron density was estimated to be around 1012 cm-3 using the Stark broadening of the hydrogen Hβ line at 486.1 nm. The main population and loss mechanisms considered in the model for the excited argon atom and ion states emitting in the VUV range are discussed. The experimental results were compared to self-consistent model predictions, and a good agreement was obtained.

  19. ELISA reader does not interfere by mobile phone radiofrequency radiation

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Javad Mortazavi

    2016-01-01

    Conclusion: This study showed that ELISA reader does not interfere by mobile phone RF radiation at a closed contact (less than 5 cm distance. However, we recommend that medical institutions discuss these issues in the context of their specific use of technologies and frame a policy that is clear and straightforward to guide staff, patients, and visitors.

  20. Exposure to 1800 MHz radiofrequency radiation induces oxidative damage to mitochondrial DNA in primary cultured neurons.

    Science.gov (United States)

    Xu, Shangcheng; Zhou, Zhou; Zhang, Lei; Yu, Zhengping; Zhang, Wei; Wang, Yuan; Wang, Xubu; Li, Maoquan; Chen, Yang; Chen, Chunhai; He, Mindi; Zhang, Guangbin; Zhong, Min

    2010-01-22

    Increasing evidence indicates that oxidative stress may be involved in the adverse effects of radiofrequency (RF) radiation on the brain. Because mitochondrial DNA (mtDNA) defects are closely associated with various nervous system diseases and mtDNA is particularly susceptible to oxidative stress, the purpose of this study was to determine whether radiofrequency radiation can cause oxidative damage to mtDNA. In this study, we exposed primary cultured cortical neurons to pulsed RF electromagnetic fields at a frequency of 1800 MHz modulated by 217 Hz at an average special absorption rate (SAR) of 2 W/kg. At 24 h after exposure, we found that RF radiation induced a significant increase in the levels of 8-hydroxyguanine (8-OHdG), a common biomarker of DNA oxidative damage, in the mitochondria of neurons. Concomitant with this finding, the copy number of mtDNA and the levels of mitochondrial RNA (mtRNA) transcripts showed an obvious reduction after RF exposure. Each of these mtDNA disturbances could be reversed by pretreatment with melatonin, which is known to be an efficient antioxidant in the brain. Together, these results suggested that 1800 MHz RF radiation could cause oxidative damage to mtDNA in primary cultured neurons. Oxidative damage to mtDNA may account for the neurotoxicity of RF radiation in the brain.

  1. Cognitive effects of radiation emitted by cellular phones: the influence of exposure side and time.

    Science.gov (United States)

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

    2009-04-01

    This study examined the time dependence effects of exposure to radiofrequency radiation (RFR) emitted by standard GSM cellular phones on the cognitive functions of humans. A total of 48 healthy right-handed male subjects performed a spatial working memory task (that required either a left-hand or a right-hand response) while being exposed to one of two GSM phones placed at both sides of the head. The subjects were randomly divided into three groups. Each group was exposed to one of three exposure conditions: left-side of the head, right-side, or sham-exposure. The experiment consisted of 12 blocks of trials. Response times (RTs) and accuracy of the responses were recorded. It was found that the average RT of the right-hand responses under left-side exposure condition was significantly longer than those of the right-side and sham-exposure groups averaged together during the first two time blocks. These results confirmed the existence of an effect of exposure on RT, as well as the fact that exposure duration (together with the responding hand and the side of exposure) may play an important role in producing detectable RFR effects on performance. Differences in these parameters might be the reason for the failure of certain studies to detect or replicate RFR effects. (c) 2008 Wiley-Liss, Inc.

  2. ELISA reader does not interfere by mobile phone radiofrequency radiation.

    Science.gov (United States)

    Mortazavi, Seyyed Mohammad Javad; Baradaran-Ghahfarokhi, Hamid Reza; Abdi, Mohammad Reza; Baradaran-Ghahfarokhi, Milad; Mostafavi, Nayyer Sadat; Mahmoudi, Golshan; Berenjkoub, Nafiseh; Akmali, Zahra; Hossein-Beigi, Fahimeh; Arsang, Vajiheh

    2016-01-01

    The increasing number of mobile phones can physically cause electromagnetic interference (EMI) in medical environments; can also cause errors in immunoassays in laboratories. The ELISA readers are widely used as a useful diagnostic tool for Enzymun colorimetric assay in medicine. The aim of this study was to investigate whether the ELISA reader could be interfered by the exposure to the 900 MHz cell phones in the laboratory. Human serum samples were collected from 14 healthy donors (9 women and 5 men) and each sample was divided into four aliquots and was placed into four batches for the in-vitro quantitative determination of human chorionic gonadotropin (hCG). During colorimetric reading of the first, second, and third batches, the ELISA reader (Stat Fax 2100, Awareness Technology, Inc., USA) was exposed to 0.5, 1.0, and 2.0 W exposure of 900 MHz radiation, respectively. For the forth batch (control group), no radiation was applied. All experiments were performed comparing ELISA read out results of the I, II, and III batches with the control batch, using the Wilcoxon test with criterion level of P = 0.050. The final scores in the exposed batches I, II, and III were not statistically significant relative to the control batch (P > 0.05). The results showed that 900 MHz radiation exposure did not alter the ELISA measured levels of hCG hormone in I (P = 0.219), II (P = 0.909), and III (P = 0.056) batches compared to the control batch. This study showed that ELISA reader does not interfere by mobile phone RF radiation at a closed contact (less than 5 cm distance). However, we recommend that medical institutions discuss these issues in the context of their specific use of technologies and frame a policy that is clear and straightforward to guide staff, patients, and visitors.

  3. Ultraviolet radiation emitted by CO(2) arc welding.

    Science.gov (United States)

    Okuno, T; Ojima, J; Saito, H

    2001-10-01

    The arcs associated with arc welding emit high levels of ultraviolet radiation (UVR), and this often causes acute injuries in the workplace, particularly photokeratoconjunctivitis. It is important to know the level of UVR emitted by arc welding under various conditions, as this information will help in evaluating potential UVR hazards in welding workplaces and taking protective measures against it. In this study, the ACGIH effective irradiance for UVR was measured experimentally for CO(2) arc welding in order to evaluate its UVR hazards. A welding robot was used in the experiment in order to realize reproducible and consistent welding operations. The effective irradiance at 1 m from the arc was in the range 0.28-7.85 W/m(2) (28-785 microW/cm(2)) under the study conditions. The corresponding permissible exposure time per day is only 4-100 s, suggesting that UVR from CO(2) arc welding is actually hazardous for the eye and skin. It was found that the effective irradiance is inversely proportional to the square of the distance from the arc, is strongly dependent on the direction of emission from the arc with a maximum at 50-60 degrees from the plate surface, and tends to increase with welding current.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Direct detection of the Josephson radiation emitted from superconducting thin-film microbridges

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sørensen, O. H.; Mygind, Jesper;

    1976-01-01

    We report direct measurements of the Josephson radiation emitted in X band from a superconducting thin-film microbridge coupled to a resonance cavity. Power is emitted if one of the harmonics of the Josephson frequency is in the bandwidth of the receiver. The maximum power emitted during our expe...... experiment was 10−13 W. The Josephson radiation could easily be detected at frequencies off resonance. Applied Physics Letters is copyrighted by The American Institute of Physics....

  9. Polarization of Radiation Emitted after Electron Impact Excitation

    Institute of Scientific and Technical Information of China (English)

    WU Ze-Qing; LI Yue-Ming; DUAN Bin; YAN Jun; ZHANG Hong

    2007-01-01

    A programme is developed to calculate the polarizations of the radiation emitted after electron impact excitation. The fully relativistic distorted-wave method is used in cross-section calculations. The programme is applied to He- and Li-like ions. The calculated values of line polarization are compared with other theoretical results and experimental values. For He-like U, at lower incident energy, the present polarization agrees with the other theoretical ones within 1%, while at higher energy, the differences increase up to about 10%. For He-like Fe and Ti, the present results of polarization degree for most of the lines agree with the experimental data within the experimental error bars. For the Li-like Ti line q (1s2s2p2P3/2 to 1s22s), the present value of the polarization agree excellently with another theoretical one, and both the values are consistent with the measured data within the experimental error bar.

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

    Science.gov (United States)

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

    2004-07-01

    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.

  11. 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.

  12. Radiofrequency ablation using BarRx for the endoscopic treatment of radiation proctopathy: a series of three cases

    Directory of Open Access Journals (Sweden)

    Patel A

    2014-12-01

    Full Text Available Anish Patel, Rahul Pathak, Vrushak Deshpande, Sunil H Patel, Prasanna C Wickremesinghe, Deepak Vadada Department of Gastrointestinal Medicine, Richmond University Medical Center, Staten Island, NY, USA Abstract: Radiation proctopathy is a complication of pelvic radiotherapy, which occurs in patients treated for carcinoma of the prostate, rectum, urinary bladder, cervix, uterus, and testes. If it presents within 6 weeks to 9 months after therapy, it is called acute radiation proctitis/proctopathy (ARP, and if it occurs 9 months to a year after treatment, it is classified as chronic radiation proctitis/proctopathy (CRP. CRP occurs in 5%–20% of patients receiving pelvic radiation, depending on the radiation dose and the presence or absence of chemotherapy. In many cases, CRP resolves spontaneously, but in some, it can lead to persistent rectal bleeding. Other symptoms of CRP include diarrhea, mucoid discharge, urgency, tenesmus, rectal pain, and fecal incontinence. Despite the availability of several therapies, many patients fail to respond, and continue to suffer in their quality of life. Radiofrequency ablation (RFA is a newer endoscopic technique that uses radiofrequency energy to ablate tissue. This is an emerging way to treat radiation proctopathy and other mucosal telangiectasia. We present three cases of radiation proctopathy treated with RFA at our institute and review the literature on treatment modalities for CRP. We were also able to find 16 other cases of CRP that used RFA, and review their literature as well as literature on other treatment modalities. Keywords: radiofrequency ablation, radiation proctopathy, BarRx, Halo catheter

  13. Epidemiological studies of radio-frequency radiation: Current status and areas of concern

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, John R. [Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva (Israel)

    1996-02-11

    These comments deal with the possible impact on human populations of intense sources of radio-frequency radiation, and not the much lower level of the usual sources of such radiation associated, for example with household appliances. These intense sources were developed and extensively used first in World War II (1940-45). Much of the health evaluation has been done by, and for, military organizations. There are important differences in the energy generated by low frequency (ELF) and radar; it then follows that there may be differences in their effects on human populations. Problems common to both types are: (1) the uncertainty as to biological mechanisms; (2) weak experimental evidence of effect; (3) epidemiological preoccupation with carcinogenesis, with its latency and low incidence. For both types there is the presumption of greater occupational than community risk, the latter often not well studied, and problems as to exposure quantification and specificity. To these one must add (4) the inherently epidemiological problems of a study at a given source of adequate sample size, case-findings, exposure estimation, confounders, and residential and job instability. Despite these problems, there are findings from sets of studies which suggest four possible health effects from radar (radio-frequency radiation) exposure: (A) disturbances in blood counts, not necessarily of clinical severity; (B) changes in chromosomes of white blood cells; (C) increases in frequency of unfavorable reproductive outcomes, especially spontaneous abortion, and (D) increases in cancers of certain sites. A review article on this topic was published elsewhere, providing evidence from various exposures on such possible effects. A brief critique is provided of evidence on these four possible effects, identifying some areas of uncertainty for which studies at sites like Skrunda could provide useful information

  14. 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.

  15. 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 (pradio-frequency radiation 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.

  16. 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.

  17. Cancer in radar technicians exposed to radiofrequency/microwave radiation: sentinel episodes.

    Science.gov (United States)

    Richter, E; Berman, T; Ben-Michael, E; Laster, R; Westin, J B

    2000-01-01

    Controversy exists concerning the health risks from exposures to radiofrequency/microwave irradiation (RF/MW). The authors report exposure-effect relationships in sentinel patients and their co-workers, who were technicians with high levels of exposure to RF/MW radiation. Information about exposures of patients with sentinel tumors was obtained from interviews, medical records, and technical sources. One patient was a member of a cohort of 25 workers with six tumors. The authors estimated relative risks for cancer in this group and latency periods for a larger group of self-reported individuals. Index patients with melanoma of the eye, testicular cancer, nasopharyngioma, non-Hodgkin's lymphoma, and breast cancer were in the 20-37-year age group. Information about work conditions suggested prolonged exposures to high levels of RF/MW radiation that produced risks for the entire body. Clusters involved many different types of tumors. Latency periods were extremely brief in index patients and a larger self-reported group. The findings suggest that young persons exposed to high levels of RF/MW radiation for long periods in settings where preventive measures were lax were at increased risk for cancer. Very short latency periods suggest high risks from high-level exposures. Calculations derived from a linear model of dose-response suggest the need to prevent exposures in the range of 10-100 microw/cm(2).

  18. 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.

  19. Non-fluoroscopic navigation systems for radiofrequency catheter ablation for supraventricular tachycardia reduce ionising radiation exposure.

    Science.gov (United States)

    See, Jason; Amora, Jonah L; Lee, Sheldon; Lim, Paul; Teo, Wee Siong; Tan, Boon Yew; Ho, Kah Leng; Lee, Chee Wan; Ching, Chi-Keong

    2016-07-01

    The use of non-fluoroscopic systems (NFS) to guide radiofrequency catheter ablation (RFCA) for the treatment of supraventricular tachycardia (SVT) is associated with lower radiation exposure. This study aimed to determine if NFS reduces fluoroscopy time, radiation dose and procedure time. We prospectively enrolled patients undergoing RFCA for SVT. NFS included EnSiteTM NavXTM or CARTO® mapping. We compared procedure and fluoroscopy times, and radiation exposure between NFS and conventional fluoroscopy (CF) cohorts. Procedural success, complications and one-year success rates were reported. A total of 200 patients over 27 months were included and RFCA was guided by NFS for 79 patients; those with atrioventricular nodal reentrant tachycardia (AVNRT), left-sided atrioventricular reentrant tachycardia (AVRT) and right-sided AVRT were included (n = 101, 63 and 36, respectively). Fluoroscopy times were significantly lower with NFS than with CF (10.8 ± 11.1 minutes vs. 32.0 ± 27.5 minutes; p < 0.001). The mean fluoroscopic dose area product was also significantly reduced with NFS (NSF: 5,382 ± 5,768 mGy*cm2 vs. CF: 21,070 ± 23,311 mGy*cm2; p < 0.001); for all SVT subtypes. There was no significant reduction in procedure time, except for left-sided AVRT ablation (NFS: 79.2 minutes vs. CF: 116.4 minutes; p = 0.001). Procedural success rates were comparable (NFS: 97.5% vs. CF: 98.3%) and at one-year follow-up, there was no significant difference in the recurrence rates (NFS: 5.2% vs. CF: 4.2%). No clinically significant complications were observed in both groups. The use of NFS for RFCA for SVT is safe, with significantly reduced radiation dose and fluoroscopy time. Copyright © Singapore Medical Association.

  20. Numerical calculations for the angular distribution of gamma radiation emitted by oriented 58Co NUCLEI

    NARCIS (Netherlands)

    Cox, J.A.M.; Groot, S.R. de; Hartogh, Chr.D.

    1953-01-01

    In this note the theoretical results for the angular distribution of γ-radiation emitted by oriented radioactive nuclei are applied to the case of 58Co nuclei. The angular distribution function of the γ-radiation has been calculated for an arbitrary degree of nuclear orientation and in dependence of

  1. 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.)

  2. 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.)

  3. Quantum properties of the radiation emitted by a conductor in the Coulomb blockade regime

    Science.gov (United States)

    Mora, C.; Altimiras, C.; Joyez, P.; Portier, F.

    2017-03-01

    We present an input-output formalism describing a tunnel junction strongly coupled to its electromagnetic environment. We exploit it in order to investigate the dynamics of the radiation being emitted and scattered by the junction. We find that the nonlinearity imprinted in the electronic transport by a properly designed environment generates strongly squeezed radiation. Our results show that the interaction between a quantum conductor and electromagnetic fields can be exploited as a resource to design simple sources of nonclassical radiation.

  4. Acoustic radiation force impulse elastography for hepatocellular carcinoma-associated radiofrequency ablation

    Institute of Scientific and Technical Information of China (English)

    Hee-Jin Kwon; Myong-Jin Kang; Jin-Han Cho; Jong-Young Oh; Kyung-Jin Nam; Sang-Yeong Han; Sung Wook Lee

    2011-01-01

    AIM: To evaluate the potential usefulness of acoustic radiation force impulse (ARFI) images for evaluation of hepatocellular carcinomas (HCC)-associated radiofrequency ablation.METHODS: From January 2010 to June 2010, a total of 38 patients with HCC including recurred HCCs after RFA underwent ARFI elastography.The brightness of tumor was checked and the shear wave velocity was measure-d for the quantification of stiffness.According to the b-rightness, the tumors were classified as brighter, same color and darker compared with adjacent parenchyma.Using the same methods, 8 patients with recurred HCCs after RFA state were evaluated about the brightness compared with adjacent RFA ablation area.RESULTS: In the 38 patients with HCCs, 20 (52.6%) were brighter than surrounding cirrhotic parenchyma.Another 13 (34.2%) were darker.The others (5 cases, 13.2%) were seen as the same color as the adjacent liver parenchyma.Post-RFA lesions were darker than previous tumor and surrounding parenchyma in all 38 cases.However, recurred HCCs were brighter than the treated site in all 8 cases.CONCLUSION: Using ARFI technique is helpful for differential diagnosis in order to detect recurred HCCs more easily in patients with confusing status.

  5. 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.

  6. Ultraviolet radiation emitted by lamps, TVs, tablets and computers: are there risks for the population?

    Science.gov (United States)

    Duarte, Ida Alzira Gomes; Hafner, Mariana de Figueiredo Silva; Malvestiti, Andrey Augusto

    2015-01-01

    The frequent human exposure to various types of indoor lamps, as well as other light sources (television monitors, tablets and computers), raises a question: are there risks for the population? In the present study the emission of UVA and UVB radiation by lamps and screens of electronic devices were measured in order to determine the safe distance between the emitting source and the individual. We concluded that the lamps and electronic devices do not emit ultraviolet radiation; so they pose no health risk for the population.

  7. Three-Dimensional Radiation in Absorbing -Emitting-Scattering Medium Using the Discrete-Ordinates Approximation

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The discrete-ordinates method is a simple,accurate and of little computational time solution to predict the radiactive heat transfer in the combustion chambers,In this paper,three-dimension radiative problems for absorbing-emitting-scattering medium are modeled using this method in the rectangular enclosure.And in addition,new discrete-ordinates are developed to study the absorbing-emitting-scattering radiation processes for complex phase function.The reasonable results can be obtained though these new ordinates,yet the deviated results are only obtained through conventional Sn ordinates.

  8. 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

  9. 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

    2017-03-01

    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). 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. Our finding showed that exposure to GSM cell phone RF radiation was capable of altering the pattern of ERα gene

  10. Device for determining relative angular position between a spacecraft and a radiation emitting celestial body

    Science.gov (United States)

    Farthing, W. H.; Frisbie, H. F. (Inventor)

    1973-01-01

    Signals indicative of the relative angular position between a spin stabilized spacecraft, probe, or sounding rocket and a radiation emitting celestial body are derived with a detector including four electrodes for deriving indications of the centroid of the radiation image on the detector. During each spin of the satellite each electrode derives a signal having a first non-zero level while the detector is not illuminated by the radiation, and a sound non-zero level while it is illuminated by the radiation.

  11. Radiated radiofrequency immunity testing of automated external defibrillators - modifications of applicable standards are needed

    Directory of Open Access Journals (Sweden)

    Bassen Howard I

    2011-07-01

    Full Text Available Abstract Background We studied the worst-case radiated radiofrequency (RF susceptibility of automated external defibrillators (AEDs based on the electromagnetic compatibility (EMC requirements of a current standard for cardiac defibrillators, IEC 60601-2-4. Square wave modulation was used to mimic cardiac physiological frequencies of 1 - 3 Hz. Deviations from the IEC standard were a lower frequency limit of 30 MHz to explore frequencies where the patient-connected leads could resonate. Also testing up to 20 V/m was performed. We tested AEDs with ventricular fibrillation (V-Fib and normal sinus rhythm signals on the patient leads to enable testing for false negatives (inappropriate "no shock advised" by the AED. Methods We performed radiated exposures in a 10 meter anechoic chamber using two broadband antennas to generate E fields in the 30 - 2500 MHz frequency range at 1% frequency steps. An AED patient simulator was housed in a shielded box and delivered normal and fibrillation waveforms to the AED's patient leads. We developed a technique to screen ECG waveforms stored in each AED for electromagnetic interference at all frequencies without waiting for the long cycle times between analyses (normally 20 to over 200 s. Results Five of the seven AEDs tested were susceptible to RF interference, primarily at frequencies below 80 MHz. Some induced errors could cause AEDs to malfunction and effectively inhibit operator prompts to deliver a shock to a patient experiencing lethal fibrillation. Failures occurred in some AEDs exposed to E fields between 3 V/m and 20 V/m, in the 38 - 50 MHz range. These occurred when the patient simulator was delivering a V-Fib waveform to the AED. Also, we found it is not possible to test modern battery-only-operated AEDs for EMI using a patient simulator if the IEC 60601-2-4 defibrillator standard's simulated patient load is used. Conclusions AEDs experienced potentially life-threatening false-negative failures from

  12. 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.

  13. Asymmetric lateral coherence of betatron radiation emitted in laser-driven light sources

    Science.gov (United States)

    Paroli, B.; Chiadroni, E.; Ferrario, M.; Petrillo, V.; Potenza, M. A. C.; Rossi, A. R.; Serafini, L.; Shpakov, V.

    2015-08-01

    We show that the radiation emitted by betatron oscillations of a high-energy electron beam undergoing wake-field acceleration is endowed with peculiar coherence properties which deliver quantitative information about the electron trajectories. Such results are achieved by means of accurate numerical simulations and a simple geometrical model gives a clear physical interpretation.

  14. Evaluation of radiation dose to anthropomorphic paediatric models from positron-emitting labelled tracers

    NARCIS (Netherlands)

    Xie, Tianwu; Zaidi, Habib

    2014-01-01

    PET uses specific molecules labelled with positron-emitting radionuclides to provide valuable biochemical and physiological information. However, the administration of radiotracers to patients exposes them to low-dose ionizing radiation, which is a concern in the paediatric population since children

  15. Estimating gravitational radiation from super-emitting compact binary systems

    CERN Document Server

    Hanna, Chad; Lehner, Luis

    2016-01-01

    Binary black hole mergers are among the most violent events in the Universe, leading to extreme warping of spacetime and copious emission of gravitational radiation. Even though black holes are the most compact objects they are not necessarily the most efficient emitters of gravitational radiation in binary systems. The final black hole resulting from a binary black hole merger retains a significant fraction of the pre-merger orbital energy and angular momentum. A non-vacuum system can in principle shed more of this energy than a black hole merger of equivalent mass. We study these super-emitters through a toy model that accounts for the possibility that the merger creates a compact object that retains a long-lived time-varying quadrupole moment. This toy model can capture the merger of neutron stars, but it can also be used to consider more exotic compact binaries. We hope that this toy model can serve as a guide to more rigorous numerical investigations into these systems.

  16. 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 mobile base stations, showed significantly (p mobile 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.

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

    Institute of Scientific and Technical Information of China (English)

    JIA Hui-lin; WANG En-yuan; SONG Xiao-yan; ZHANG Hong-jie; LI Zhong-hui

    2009-01-01

    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.

  18. Burst intensification by singularity emitting radiation in multi-stream flows

    CERN Document Server

    Pirozhkov, A S; Pikuz, T A; Faenov, A Ya; Ogura, K; Hayashi, Y; Kotaki, H; Ragozin, E N; Neely, D; Kiriyama, H; Koga, J K; Fukuda, Y; Sagisaka, A; Nishikino, M; Imazono, T; Hasegawa, N; Kawachi, T; Bolton, P R; Daido, H; Kato, Y; Kondo, K; Bulanov, S V; Kando, M

    2016-01-01

    In various media the elementary components can emit traveling waves such as electromagnetic, gravitational or acoustic types. If these elementary emitters are synchronized, the resulting emission is coherent. Moreover, the faster the emitters approach an observer, the more intense and directional their apparent emission is, with associated frequency increase. Multi-stream flows ubiquitously occur in media (such as with shock waves and jets in astrophysical and laboratory plasmas) and produce fast moving density singularities, where high concentration and synchronism can bring constructive interference. However, a singularity emitting such characteristic coherent radiation has not been demonstrated yet. We show this general phenomenon in laser-driven relativistic plasma, which is an ideal medium for realizing these effects in the laboratory under controllable conditions. Our experiments and simulations reveal bright coherent soft x-ray radiation from nanoscale electron density singularities in multi-stream pla...

  19. Effects of Long Term Exposure of 900-1800 MHz Radiation Emitted from 2G Mobile Phone on Mice Hippocampus- A Histomorphometric Study

    Science.gov (United States)

    Shanmugasamy, Kathirvelu; Anbalagan, Jayaram; Rajanarayanan, Swamynathan; Meenachi, Swamynathan

    2016-01-01

    Introduction The advancement in the telecommunications technology with multi-functional added features in mobile phone, attracts more users of all age group. It is alarming to note that, the mobile phone use has increased amongst children and they are exposed to potentially harmful radiofrequency radiation in their lifetime. Aim To investigate the long term exposure of 900 to 1800 MHz radiations emitted from 2G mobile phone in mice hippocampus at histomorphometric level. Materials and Methods With due approval from institutional animal ethics committee, 36 mice were exposed to 2G mobile phone radiation, 48 minutes per day for a period of 30-180 days. The control group was kept under similar conditions without 2G exposure. Mice were sacrificed and the brain was removed from the first month to six months period. Brain was removed from the cranial cavity and hippocampus region was dissected out carefully and processed for routine histological study. Random serial sections were analysed under microscope for histomorphometric changes. For statistical analysis, independent t-test was used for comparing control and 2G exposed groups. Results The mean density of neurons in the hippocampus regions CA1, CA2 and DGDB from first to sixth month was significantly lower in the 2G exposed groups; however, in CA3 and DGVB, the 2G exposed mice showed significantly higher density of neurons. The mean nuclear diameter of neurons in the hippocampus region of CA1, CA2, CA3, DGDB and DGVB from first to sixth months showed lower nuclear diameter in 2G exposed mice. Conclusion The long term exposure to 900-1800 MHz frequency radiations emitted from 2G mobile phone could cause significantly reduced neuron density and decreased nuclear diameter in the hippocampus neurons of mice. PMID:27656427

  20. [Effect of radio-frequency electromagnetic radiation on physiological features of Saccharomyces cerevisiae strain UCM Y-517].

    Science.gov (United States)

    Voĭchuk, S I; Podgorskiĭ, V S; Gromozova, E N

    2004-01-01

    Effect of electromagnetic radiation (40.68 MHz) on growth characteristics of Saccharomyces cerevisiae strain UCM Y-517 has been studied. Reliable increase of the specific growth rate (by 7-15%) and change of duration of growth phases as a result of irradiation of yeast population has been shown. The EMR effect has been found to depend on physiological state of the irradiated cells and composition of the irradiation performance medium: reliable effects were found only for the cells preliminarily grown on the dense nutrition medium in the late phase of delayed growth or on achieving the stationary growth phase. The role of radiation term and power as well as of temperature factor in EMR effect on the cells is discussed. It has been noted that the dependence of specific growth rate of yeast on the initial density of cells population acquire the nonlinear character as affected by EMR of radiofrequency range.

  1. Human fibroblasts and 900 MHz radiofrequency radiation: evaluation of DNA damage after exposure and co-exposure to 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5h)-furanone (MX).

    Science.gov (United States)

    Sannino, A; Di Costanzo, G; Brescia, F; Sarti, M; Zeni, O; Juutilainen, J; Scarfì, M R

    2009-06-01

    The aim of this study was to investigate DNA damage in human dermal fibroblasts from a healthy subject and from a subject affected by Turner's syndrome that were exposed for 24 h to radiofrequency (RF) radiation at 900 MHz. The RF-radiation exposure was carried out alone or in combination with 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a well-known environmental mutagen and carcinogen produced during the chlorination of drinking water. Turner's syndrome fibroblasts were also exposed for a shorter time (1 h). A signal similar to that emitted by Global System for Mobile Communications (GSM) mobile phones was used at a specific absorption rate of 1 W/kg under strictly controlled conditions of temperature and dosimetry. To evaluate DNA damage after RF-radiation exposure alone, the alkaline comet assay and the cytokinesis-block micronucleus assay were used. In the combined-exposure experiments, MX was given at a concentration of 25 microM for 1 h immediately after the RF-radiation exposure, and the effects were evaluated by the alkaline comet assay. The results revealed no genotoxic and cytotoxic effects from RF radiation alone in either cell line. As expected, MX treatment induced an increase in DNA migration in the comet assay, but no enhancement of the MX-induced DNA damage was observed in the cells exposed to RF radiation.

  2. Effect of Index of Refraction on Radiation Characteristics in a Heated Absorbing, Emitting, and Scattering Layer

    Science.gov (United States)

    Siegel, R.; Spuckler, C. M.

    1992-01-01

    The index of refraction can considerably influence the temperature distribution and radiative heat flow in semitransparent materials such as some ceramics. For external radiant heating, the refractive index influences the amount of energy transmitted into the interior of the material. Emission within a material depends on the square of its refractive index, and hence this emission can be many times that for a biackbody radiating into a vacuum. Since radiation exiting through an interface into a vacuum cannot exceed that of a blackbody, there is extensive reflection at the internal surface of an interface, mostly by total internal reflection. This redistributes energy within the layer and tends to make its temperature distribution more uniform. The purpose of the present analysis is to show that, for radiative equilibrium in a gray layer with diffuse interfaces, the temperature distribution and radiative heat flux for any index of refraction can be obtained very simply from the results for an index of refraction of unity. For the situation studied here, the layer is subjected to external radiative heating incident on each of its surfaces. The material emits, absorbs, and isotropically scatters radiation. For simplicity the index of refraction is unity in the medium surrounding the layer. The surfaces of the layer are assumed diffuse. This is probably a reasonable approximation for a ceramic layer that has not been polished. When transmitted radiation or radiation emitted from the interior reaches the inner surface of an interface, the radiation is diffused and some of it thereby placed into angular directions for which there is total internal reflection. This provides a trapping effect for retaining energy within the layer and tends to equalize its temperature distribution. An analysis of temperature distributions in absorbing-emitting layers, including index of refraction effects, was developed by Gardon (1958) to predict cooling and heat treating of glass plates

  3. Marked increase in the teratogenicity of the combined administration of the industrial solvent 2-methoxyethanol and radiofrequency radiation in rats

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, B.K.; Conover, D.L.; Brightwell, W.S.; Shaw, P.B.; Werren, D.; Edwards, R.M.; Lary, J.M. (Division of Biomedical and Behavioral Science, National Institute for Occupational Safety and Health, Cincinnati, OH (United States))

    1991-06-01

    Limited published animal research reports synergistic teratogenic effects following combined hyperthermia (induced by elevated ambient temperature) and administration of chemical teratogens. Radiofrequency (RF) radiation is widely used in occupational environments. Since RF radiation also elevates the body temperature of, and is teratogenic to, exposed animals, concurrent RF radiation and chemical agent administration may enhance teratogenicity. The present exploratory study, consisting of preliminary dose-finding studies and the primary study, was designed to investigate whether concurrent exposure of rats to RF radiation and the industrial solvent 2-methoxyethanol (2ME) can enhance the developmental toxicity of either agent acting alone. Preliminary dose-finding studies using small numbers of rats investigated the ability of various RF radiation conditions and doses of 2ME to produce external malformations (primarily of the paws) when administered on gestation day 13. Based on these preliminary studies, RF radiation exposure (sufficient to elevate rectal temperature to 42.0 degrees C (4 degrees C above normal for rats) for 30 min) and 2ME administration (150 mg/kg) were selected for the primary study. In the primary study, groups of 18 to 27 pregnant rats were administered RF radiation exposure and distilled water gavage, 2ME gavage and sham RF exposure, RF radiation exposure and 2ME gavage concurrently, or sham RF exposure and distilled water gavage. Pregnant rats were sacrificed on gestation day 20, and the offspring were examined for external malformations. Combined exposures enhanced the adverse effects produced by either experimental agent alone (no malformations were detected in the double sham group).

  4. 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.

  5. Direct radiative effect of aerosols emitted by transport: from road, shipping and aviation

    Directory of Open Access Journals (Sweden)

    Y. Balkanski

    2010-05-01

    Full Text Available Aerosols and their precursors are emitted abundantly by transport activities. Transportation constitutes one of the fastest growing activities and its growth is predicted to increase significantly in the future. Previous studies have estimated the aerosol direct radiative forcing from one transport sub-sector, but only one study to our knowledge estimated the range of radiative forcing from the main aerosol components (sulphate, black carbon (BC and organic carbon for the whole transportation sector. In this study, we compare results from two different chemical transport models and three radiation codes under different hypothesis of mixing: internal and external mixing using emission inventories for the year 2000. The main results from this study consist of a positive direct radiative forcing for aerosols emitted by road traffic of +20±11 mW m−2 for an externally mixed aerosol, and of +32±13 mW m−2 when BC is internally mixed. These direct radiative forcings are much higher than the previously published estimate of +3±11 mW m−2. For transport activities from shipping, the net direct aerosol radiative forcing is negative. This forcing is dominated by the contribution of the sulphate. For both an external and an internal mixture, the radiative forcing from shipping is estimated at −26±4 mW m−2. These estimates are in very good agreement with the range of a previously published one (from −46 to −13 mW m−2 but with a much narrower range. By contrast, the direct aerosol forcing from aviation is estimated to be small, and in the range −0.9 to +0.3 mW m−2.

  6. Evaluation of blackbody radiation emitted by arbitrarily shaped bodies using the source model technique.

    Science.gov (United States)

    Sister, Ilya; Leviatan, Yehuda; Schächter, Levi

    2017-06-12

    Planck's famous blackbody radiation law was derived under the assumption that the dimensions of the radiating body are significantly larger than the radiated wavelengths. What is unique about Planck's formula is the fact that it is independent of the exact loss mechanism and the geometry. Therefore, for a long period of time, it was regarded as a fundamental property of all materials. Deviations from its predictions were attributed to imperfections and referred to as the emissivity of the specific body, a quantity which was always assumed to be smaller than unity. Recent studies showed that the emission spectrum is affected by the geometry of the body and in fact, in a limited frequency range, the emitted spectrum may exceed Planck's prediction provided the typical size of the body is of the same order of magnitude as the emitted wavelength. For the investigation of the blackbody radiation from an arbitrarily shaped body, we developed a code which incorporates the fluctuation-dissipation theorem (FDT) and the source model technique (SMT). The former determines the correlation between the quasi-microscopic current densities in the body and the latter is used to solve the electromagnetic problem numerically. In this study we present the essence of combining the two concepts. We verify the validity of our code by comparing its results obtained for the case of a sphere against analytic results and discuss how the accuracy of the solution is assessed in the general case. Finally, we illustrate several configurations in which the emitted spectrum exceeds Planck's prediction as well as cases in which the geometrical resonances of the body are revealed.

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

    CERN Document Server

    Victor, U J Nwankwo; 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 \\mu W/sq m) from mobile base stations relative to radial distance (in metre). The minimum average power density from individual base station in the town was about 47\\mu W/sq m while the average maximum was about 1.5mW/sq m. Our result showed that average power density of a base station decreases with increase in distance (from base station) and that radiation intensity varies from one base station to another even at the same distance away. Our result (obtained signature of power density variation) was also compared with the 'expected' signature. It was found that radiation from external...

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

    CERN Document Server

    Ushie, P O; 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/sqm for 18000MHz) set by the International Commission on Non-ionizing Radiation Protection (ICNIRP) and other regulatory agencies.

  9. 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.

  10. 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

    2016-01-01

    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 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. PMID:27633090

  11. Hazard of ultraviolet radiation emitted in gas tungsten arc welding of aluminum alloys.

    Science.gov (United States)

    Nakashima, Hitoshi; Utsunomiya, Akihiro; Fujii, Nobuyuki; Okuno, Tsutomu

    2016-01-01

    Ultraviolet radiation (UVR) emitted during arc welding frequently causes keratoconjunctivitis and erythema. The extent of the hazard of UVR varies depending on the welding method and conditions. Therefore, it is important to identify the levels of UVR that are present under various conditions. In this study, we experimentally evaluated the hazard of UVR emitted in gas tungsten arc welding (GTAW) of aluminum alloys. The degree of hazard of UVR is measured by the effective irradiance defined in the American Conference of Governmental Industrial Hygienists guidelines. The effective irradiances measured in this study are in the range 0.10-0.91 mW/cm(2) at a distance of 500 mm from the welding arc. The maximum allowable exposure times corresponding to these levels are only 3.3-33 s/day. This demonstrates that unprotected exposure to UVR emitted by GTAW of aluminum alloys is quite hazardous in practice. In addition, we found the following properties of the hazard of UVR. (1) It is more hazardous at higher welding currents than at lower welding currents. (2) It is more hazardous when magnesium is included in the welding materials than when it is not. (3) The hazard depends on the direction of emission from the arc.

  12. Method and system for determining depth distribution of radiation-emitting material located in a source medium and radiation detector system for use therein

    Energy Technology Data Exchange (ETDEWEB)

    Benke, Roland R. (Helotes, TX); Kearfott, Kimberlee J. (Ann Arbor, MI); McGregor, Douglas S. (Ann Arbor, MI)

    2003-03-04

    A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder positioned so that its central axis is perpendicular to the upper surface of the large area source when positioned thereon. The collimator allows the detector to angularly sample the emitted radiation over many ranges of polar angles. This is done by forming the collimator as a single adjustable collimator or a set of collimator pieces having various possible configurations when connected together. In any one configuration, the collimator allows the detector to detect only the radiation emitted from a selected range of polar angles measured from the detector axis. Adjustment of the collimator or the detector therein enables the detector to detect radiation emitted from a different range of polar angles. The system further includes a signal processor for processing the signals from the detector wherein signals obtained from different ranges of polar angles are processed together to obtain a reconstruction of the radiation-emitting material as a function of depth, assuming, but not limited to, a spatially-uniform depth distribution of the material within each layer. The detector system includes detectors having

  13. Radiation-damage-induced phasing: a case study using UV irradiation with light-emitting diodes.

    Science.gov (United States)

    de Sanctis, Daniele; Zubieta, Chloe; Felisaz, Franck; Caserotto, Hugo; Nanao, Max H

    2016-03-01

    Exposure to X-rays, high-intensity visible light or ultraviolet radiation results in alterations to protein structure such as the breakage of disulfide bonds, the loss of electron density at electron-rich centres and the movement of side chains. These specific changes can be exploited in order to obtain phase information. Here, a case study using insulin to illustrate each step of the radiation-damage-induced phasing (RIP) method is presented. Unlike a traditional X-ray-induced damage step, specific damage is introduced via ultraviolet light-emitting diodes (UV-LEDs). In contrast to UV lasers, UV-LEDs have the advantages of small size, low cost and relative ease of use.

  14. Signature of Accretion Shocks in Emitted Radiation From a Two Temperature Advective Flows Around Black Holes

    CERN Document Server

    Mandal, S; Mandal, Samir; Chakrabarti, Sandip K.

    2005-01-01

    Centrifugal barrier supported boundary layer (CENBOL) of a black hole affects the spectrum exactly in the same way the boundary layer of a neutron star does. The CENBOL is produced due to standing or oscillating shock waves and these shocks accelerate electrons very efficiently and produce a power-law distribution. The accelerated particles in turn emit synchrotron radiation in presence of the magnetic field. We study the spectral properties of an accretion disk as a function of the shock strength, compression ratio, flow accretion rate and flow geometry. In the absence of a satisfactory description of magnetic fields inside the advective disk, we consider the presence of only stochastic fields and use the ratio of the field energy density to the gravitational energy density to be a parameter. Not surprisingly, stronger fields produce stronger humps due to synchrotron radiation. We not only include `conventional' synchrotron emission and Comptonization due to Maxwell-Bolzmann electrons in the gas, we also com...

  15. 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.

  16. Interaction of ionizing radiation, genetically active chemicals, and radiofrequency radiation in human and rodent cells. Final report 1 Oct 87-30 Sep 89

    Energy Technology Data Exchange (ETDEWEB)

    Meltz, M.L.; Holahan, P.K.; Smith, S.T.; Kerbacher, J.J.; Ciaravino, V.

    1990-12-01

    The purpose of this project was to investigate the possible interaction between radiofrequency radiation (RFR) and agents which are known to damage DNA. Experiments were performed using exposures of CHO cells to 350, 850, 1200, and 2450 MHz RFR at up to 40 W/kg and temperatures ranging from 37 to 40 C. No genotoxic effect was observed by sister chromotid exchange induction, chromosome aberration induction, or gene mutation (at the thymidine kinase locus). At levels at or below 10 mW/cm2 and specific absorption rates (SARs) at or below 4 W/kg, there was no evidence that DNA repair was induced or repair of preexisting DNA damage was inhibited. Adriamycin but not mitomycin c caused a statistically significant increase in the frequency of aberrant cells at 40 C with or without RFR. These observations support thermal mechanisms of RFR interaction.

  17. Comparison of chromosome aberrations in peripheral blood lymphocytes from people occupationally exposed to ionizing and radiofrequency radiation.

    Directory of Open Access Journals (Sweden)

    Lalić H

    2001-04-01

    Full Text Available The genotoxic effects of occupational exposure to ionizing and non-ionizing radiation were investigated in 25 physicians and nurses working in hospitals and in 20 individuals working at radio-relay stations. Examination was conducted by chromosome aberration analysis of peripheral blood lymphocytes. The data showed that total number of chromosome aberrations in people exposed to ionizing and radio-frequency radiation (4.08 +/- 0.37 and 4.35 +/- 0.5 on 200 scored metaphases, respectively were almost equally higher than those of non-irradiated subjects. The increase was in proportion to the number of individuals having more that 5-aberration/200 metaphases. Acentric fragments comprised the most frequently seen type of aberration. The average numbers in examined groups (11.8 x 10(-3 and 14.8 x 10(-3 per cell, respectively, were significantly higher than 4.2 x 10(-3, which was observed in controls, unexposed individuals. Dicentric fragments were also frequent (4.8 x 10(-3 and 6.25 x 10(-3, respectively, vs. 0.52 x 10(-3 in control. In contrast, the frequency of chromatid breaks increased only after ionizing radiation (3.8 x 10(-3 vs. 0.26 x 10(-3 in control. A positive correlation between the total number of chromosome aberrations and cumulative 6-years dosage was also found. The data emphasized the dangerous effects of prolonged exposure to both types of radiation and indicated that chromosomal aberration analysis should be obligatory for individuals working at radio-relay stations.

  18. Evaluation of parameters of oxidative stress after in vitro exposure to FMCW- and CDMA-modulated radiofrequency radiation fields.

    Science.gov (United States)

    Hook, Graham J; Spitz, Douglas R; Sim, Julia E; Higashikubo, Ryuji; Baty, Jack D; Moros, Eduardo G; Roti Roti, Joseph L

    2004-11-01

    The goal of this study was to determine whether radiofrequency (RF) radiation is capable of inducing oxidative stress or affecting the response to oxidative stress in cultured mammalian cells. The two types of RF radiation investigated were frequency-modulated continuous-wave with a carrier frequency of 835.62 MHz (FMCW) and code division multiple access centered on 847.74 MHz (CDMA). To evaluate the effect of RF radiation on oxidative stress, J774.16 mouse macrophage cells were stimulated with gamma-interferon (IFN) and bacterial lipopolysaccharide (LPS) prior to exposure. Cell cultures were exposed for 20-22 h to a specific absorption rate of 0.8 W/kg at a temperature of 37.0 +/- 0.3 degrees C. Oxidative stress was evaluated by measuring oxidant levels, antioxidant levels, oxidative damage and nitric oxide production. Oxidation of thiols was measured by monitoring the accumulation of glutathione disulfide (GSSG). Cellular antioxidant defenses were evaluated by measuring superoxide dismutase activity (CuZnSOD and MnSOD) as well as catalase and glutathione peroxidase activity. The trypan blue dye exclusion assay was used to measure any changes in viability. The results of these studies indicated that FMCW- and CDMA-modulated RF radiation did not alter parameters indicative of oxidative stress in J774.16 cells. FMCW- and CDMA-modulated fields did not alter the level of intracellular oxidants, accumulation of GSSG or induction of antioxidant defenses in IFN/LPS-stimulated cells. Consistent with the lack of an effect on oxidative stress parameters, no change in toxicity was observed in J774.16 cells after either optimal (with or without inhibitors of nitric oxide synthase) or suboptimal stimulation.

  19. Properties of the Coherent Radiation Emitted from Photonic Crystal in the Millimeter Wave Region III(III. Accelerator, Synchrotron Radiation, and Instrumentation)

    OpenAIRE

    2006-01-01

    Coherent radiation emitted from a Photonic crystal of a cylindrical tube of Teflon with periodic grooves is observed in the millimeter wave region. The observed spectra show a sharp peak at frequency of 4.625cm^. The inter-bunch coherence of the radiation is confirmed with an interferometer.

  20. USAFSAM (USAF School of Aerospace Medicine) Review and Analysis of Radiofrequency Radiation Bioeffects Literature: Third Report.

    Science.gov (United States)

    1984-03-01

    radiation was studied. Female CD-i mice were induced to superovulate , mated, and exposed to 2.45-GHz microwave or sham radiation for 3 h at power densities...38 deg C heat treatment. Prior to treatment, the mice were chemically induced to superovulate and were caged overnight in pairs with males. The next

  1. Pediatric radiation dosimetry for positron-emitting radionuclides using anthropomorphic phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva 4 (Switzerland); Bolch, Wesley E. [Departments of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Lee, Choonsik [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Rockville, Maryland 20850 (United States); Zaidi, Habib [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva 4 (Switzerland); Geneva Neuroscience Center, Geneva University, CH-1205 Geneva (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, 9700 RB Groningen (Netherlands)

    2013-10-15

    Purpose: Positron emission tomography (PET) plays an important role in the diagnosis, staging, treatment, and surveillance of clinically localized diseases. Combined PET/CT imaging exhibits significantly higher sensitivity, specificity, and accuracy than conventional imaging when it comes to detecting malignant tumors in children. However, the radiation dose from positron-emitting radionuclide to the pediatric population is a matter of concern since children are at a particularly high risk when exposed to ionizing radiation.Methods: The authors evaluate the absorbed fractions and specific absorbed fractions (SAFs) of monoenergy photons/electrons as well as S-values of 9 positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Rb-82, Y-86, and I-124) in 48 source regions for 10 anthropomorphic pediatric hybrid models, including the reference newborn, 1-, 5-, 10-, and 15-yr-old male and female models, using the Monte Carlo N-Particle eXtended general purpose Monte Carlo transport code.Results: The self-absorbed SAFs and S-values for most organs were inversely related to the age and body weight, whereas the cross-dose terms presented less correlation with body weight. For most source/target organ pairs, Rb-82 and Y-86 produce the highest self-absorbed and cross-absorbed S-values, respectively, while Cu-64 produces the lowest S-values because of the low-energy and high-frequency of electron emissions. Most of the total self-absorbed S-values are contributed from nonpenetrating particles (electrons and positrons), which have a linear relationship with body weight. The dependence of self-absorbed S-values of the two annihilation photons varies to the reciprocal of 0.76 power of the mass, whereas the self-absorbed S-values of positrons vary according to the reciprocal mass.Conclusions: The produced S-values for common positron-emitting radionuclides can be exploited for the assessment of radiation dose delivered to the pediatric population from various PET

  2. Effects of light-emitting diode radiations on human retinal pigment epithelial cells in vitro.

    Science.gov (United States)

    Chamorro, Eva; Bonnin-Arias, Cristina; Pérez-Carrasco, María Jesús; Muñoz de Luna, Javier; Vázquez, Daniel; Sánchez-Ramos, Celia

    2013-01-01

    Human visual system is exposed to high levels of natural and artificial lights of different spectra and intensities along lifetime. Light-emitting diodes (LEDs) are the basic lighting components in screens of PCs, phones and TV sets; hence it is so important to know the implications of LED radiations on the human visual system. The aim of this study was to investigate the effect of LEDs radiations on human retinal pigment epithelial cells (HRPEpiC). They were exposed to three light-darkness (12 h/12 h) cycles, using blue-468 nm, green-525 nm, red-616 nm and white light. Cellular viability of HRPEpiC was evaluated by labeling all nuclei with DAPI; Production of reactive oxygen species (ROS) was determined by H2DCFDA staining; mitochondrial membrane potential was quantified by TMRM staining; DNA damage was determined by H2AX histone activation, and apoptosis was evaluated by caspases-3,-7 activation. It is shown that LED radiations decrease 75-99% cellular viability, and increase 66-89% cellular apoptosis. They also increase ROS production and DNA damage. Fluorescence intensity of apoptosis was 3.7% in nonirradiated cells and 88.8%, 86.1%, 83.9% and 65.5% in cells exposed to white, blue, green or red light, respectively. This study indicates three light-darkness (12 h/12 h) cycles of exposure to LED lighting affect in vitro HRPEpiC.

  3. Effects of radiation emitted by WCDMA mobile phones on electromagnetic hypersensitive subjects

    Directory of Open Access Journals (Sweden)

    Kwon Min Kyung

    2012-09-01

    Full Text Available Abstract Background With the use of the third generation (3 G mobile phones on the rise, social concerns have arisen concerning the possible health effects of radio frequency-electromagnetic fields (RF-EMFs emitted by wideband code division multiple access (WCDMA mobile phones in humans. The number of people with self-reported electromagnetic hypersensitivity (EHS, who complain of various subjective symptoms such as headache, dizziness and fatigue, has also increased. However, the origins of EHS remain unclear. Methods In this double-blind study, two volunteer groups of 17 EHS and 20 non-EHS subjects were simultaneously investigated for physiological changes (heart rate, heart rate variability, and respiration rate, eight subjective symptoms, and perception of RF-EMFs during real and sham exposure sessions. Experiments were conducted using a dummy phone containing a WCDMA module (average power, 24 dBm at 1950 MHz; specific absorption rate, 1.57 W/kg within a headset placed on the head for 32 min. Results WCDMA RF-EMFs generated no physiological changes or subjective symptoms in either group. There was no evidence that EHS subjects perceived RF-EMFs better than non-EHS subjects. Conclusions Considering the analyzed physiological data, the subjective symptoms surveyed, and the percentages of those who believed they were being exposed, 32 min of RF radiation emitted by WCDMA mobile phones demonstrated no effects in either EHS or non-EHS subjects.

  4. 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.

  5. Temperature dependent polarization of the thermal radiation emitted by thin, hot tungsten wires

    CERN Document Server

    Borghesani, A F; Ruoso, G

    2013-01-01

    We report measurements of the temperature $T $ dependence of the linear polarization $ $ of the thermal radiation emitted by thin, incandescent tungsten wires. We investigate an interval ranging from a little above room temperature up to melting, $T_m= 3695\\,$K. These are the first measurements in such wide a range. We found that $ $ decreases with increasing temperature. We obtained a satisfactory agreement with the theoretical predictions based on the Kirchhoff's law by using a Drude-type formula for the optical properties of tungsten. This formula was tested and its parameters were assessed as valid for $T\\leq 2400 \\,$K and for wavelengths in the range from visible up to $\\lambda\\approx 2.6\\,\\mu$m. We have extended the range of validity of this formula for $T$ up to $T_m$ and for $\\lambda$ up to $\\approx 12\\,\\mu$m.

  6. 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)

  7. Radiofrequency radiation at 1950 MHz (UMTS) does not affect key cellular endpoints in neuron-like PC12 cells.

    Science.gov (United States)

    Zeni, Olga; Sannino, Anna; Sarti, Maurizio; Romeo, Stefania; Massa, Rita; Scarfì, Maria R

    2012-09-01

    In this study, rat pheochromocytoma (PC12) cells were exposed, as a model of neuron-like cells, to 1950 MHz radiofrequency (RF) radiation with a signal used by the 3G wireless technology of the Universal Mobile Telecommunications System (UMTS) to assess possible adverse effects. RF exposure for 24 h at a specific absorption rate (SAR) of 10 W/kg was carried out in a waveguide system under accurately controlled environmental and dosimetric parameters. DNA integrity, cell viability, and apoptosis were investigated as cellular endpoints relevant for carcinogenesis and other diseases of the central nervous system. Very sensitive biological assays were employed to assess the effects immediately after RF exposure and 24 h later, as demonstrated by the cellular response elicited in PC12 cells using positive control treatments provided for each assay. In our experimental conditions, 24 h of RF exposure at a carrier frequency and modulation scheme typical of a UMTS signal was not able to elicit any effect in the selected cellular endpoints in undifferentiated PC12 cells, despite the application of a higher SAR value than those applied in the majority of the studies reported in the literature. Copyright © 2012 Wiley Periodicals, Inc.

  8. Effect of 1.8 GHz radiofrequency electromagnetic radiation on novel object associative recognition memory in mice

    Science.gov (United States)

    Wang, Kai; Lu, Jun-Mei; Xing, Zhen-He; Zhao, Qian-Ru; Hu, Lin-Qi; Xue, Lei; Zhang, Jie; Mei, Yan-Ai

    2017-01-01

    Mounting evidence suggests that exposure to radiofrequency electromagnetic radiation (RF-EMR) can influence learning and memory in rodents. In this study, we examined the effects of single exposure to 1.8 GHz RF-EMR for 30 min on subsequent recognition memory in mice, using the novel object recognition task (NORT). RF-EMR exposure at an intensity of >2.2 W/kg specific absorption rate (SAR) power density induced a significant density-dependent increase in NORT index with no corresponding changes in spontaneous locomotor activity. RF-EMR exposure increased dendritic-spine density and length in hippocampal and prefrontal cortical neurons, as shown by Golgi staining. Whole-cell recordings in acute hippocampal and medial prefrontal cortical slices showed that RF-EMR exposure significantly altered the resting membrane potential and action potential frequency, and reduced the action potential half-width, threshold, and onset delay in pyramidal neurons. These results demonstrate that exposure to 1.8 GHz RF-EMR for 30 min can significantly increase recognition memory in mice, and can change dendritic-spine morphology and neuronal excitability in the hippocampus and prefrontal cortex. The SAR in this study (3.3 W/kg) was outside the range encountered in normal daily life, and its relevance as a potential therapeutic approach for disorders associated with recognition memory deficits remains to be clarified. PMID:28303965

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

    Energy Technology Data Exchange (ETDEWEB)

    Bastide, M.; Youbicier-Simo, B.J.; Lebecq, J.C.; Giaimis, J. [Laboratoire d' Immunologie et Parasitologie, Faculte de Pharmacie, Universite de Montpellier, Montpellier (France); Youbicier-Simo, B.J. [Tecnolab, Chateau de l' Orbize, Dracy-le-Fort (France)

    2001-07-01

    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)

  10. Induction of adaptive response: pre-exposure of mice to 900 MHz radiofrequency fields reduces hematopoietic damage caused by subsequent exposure to ionising radiation.

    Science.gov (United States)

    Cao, Yi; Xu, Qian; Jin, Zong-Da; Zhou, Zhen; Nie, Ji-Hua; Tong, Jian

    2011-07-01

    To investigate whether an adaptive response can be induced in mice which were pre-exposed to 900 MHz radiofrequency fields. Adult male Kunming mice were exposed to 900 MHz radiofrequency fields (RF) at power intensities of 12, 120 and 1200 μW/cm(2) for 1 h/day for 14 days and then subjected to whole body gamma-irradiation. The results were compared with those in unexposed control animals and those exposed to gamma-irradiation alone (without pre-exposure to RF). The extent of survival and hematopoietic tissue damage (assessed in the form of nucleated colony forming cells in the bone marrow and colony forming cells in the spleen of lethally irradiated 'recipient' mice) as well as the expression of cell cycle-related genes were investigated. The results indicated a significant increase in survival time, reduction in the hematopoietic tissue damage in RF pre-exposed mice which were gamma-irradiated (as compared with those exposed to gamma-radiation alone). This was accompanied by significantly increased expression of cell cycle-related genes, namely, cyclin-D1, cyclin-E, cyclin-DK4 and cyclin-DK2 in hematopoietic cells. Pre-exposure of mice to 900 MHz radiofrequency fields has resulted in a significant reduction in hematopoietic damage caused by subsequent exposure to ionising radiation. This phenomenon appears to be similar to that of the 'adaptive response' which is well documented in scientific literature.

  11. A survey of radiation dose to patients and operators during radiofrequency ablation using computed tomography

    Science.gov (United States)

    Saidatul, A; Azlan, CA; Megat Amin, MSA; Abdullah, BJJ; Ng, KH

    2010-01-01

    Computed tomography (CT) fluoroscopy is able to give real time images to a physician undertaking minimally invasive procedures such as biopsies, percutaneous drainage, and radio frequency ablation (RFA). Both operators executing the procedure and patients too, are thus at risk of radiation exposure during a CT fluoroscopy. This study focuses on the radiation exposure present during a series of radio frequency ablation (RFA) procedures, and used Gafchromic film (Type XR-QA; International Specialty Products, USA) and thermoluminescent dosimeters (TLD-100H; Bicron, USA) to measure the radiation received by patients undergoing treatment, and also operators subject to scatter radiation. The voltage was held constant at 120 kVp and the current 70mA, with 5mm thickness. The duration of irradiation was between 150-638 seconds. Ultimately, from a sample of 30 liver that have undergone RFA, the study revealed that the operator received the highest dose at the hands, which was followed by the eyes and thyroid, while secondary staff dosage was moderately uniform across all parts of the body that were measured. PMID:21611060

  12. A survey of radiation dose to patients and operators during radiofrequency ablation using computed tomography.

    Science.gov (United States)

    Saidatul, A; Azlan, Ca; Megat Amin, Msa; Abdullah, Bjj; Ng, Kh

    2010-01-01

    Computed tomography (CT) fluoroscopy is able to give real time images to a physician undertaking minimally invasive procedures such as biopsies, percutaneous drainage, and radio frequency ablation (RFA). Both operators executing the procedure and patients too, are thus at risk of radiation exposure during a CT fluoroscopy.This study focuses on the radiation exposure present during a series of radio frequency ablation (RFA) procedures, and used Gafchromic film (Type XR-QA; International Specialty Products, USA) and thermoluminescent dosimeters (TLD-100H; Bicron, USA) to measure the radiation received by patients undergoing treatment, and also operators subject to scatter radiation.The voltage was held constant at 120 kVp and the current 70mA, with 5mm thickness. The duration of irradiation was between 150-638 seconds.Ultimately, from a sample of 30 liver that have undergone RFA, the study revealed that the operator received the highest dose at the hands, which was followed by the eyes and thyroid, while secondary staff dosage was moderately uniform across all parts of the body that were measured.

  13. Percutaneous Renal Tumor Ablation: Radiation Exposure During Cryoablation and Radiofrequency Ablation

    Energy Technology Data Exchange (ETDEWEB)

    McEachen, James C., E-mail: james.mceachen2@gmail.com [Mayo Clinic, Division of Preventive, Occupational, and Aerospace Medicine (United States); Leng, Shuai; Atwell, Thomas D. [Mayo Clinic, Department of Radiology (United States); Tollefson, Matthew K. [Mayo Clinic, Department of Urology (United States); Friese, Jeremy L. [Mayo Clinic, Department of Radiology (United States); Wang, Zhen; Murad, M. Hassan [Mayo Clinic, Division of Preventive, Occupational, and Aerospace Medicine (United States); Schmit, Grant D. [Mayo Clinic, Department of Radiology (United States)

    2016-02-15

    IntroductionOnce reserved solely for non-surgical cases, percutaneous ablation is becoming an increasingly popular treatment option for a wider array of patients with small renal masses and the radiation risk needs to be better defined as this transition continues.Materials and MethodsRetrospective review of our renal tumor ablation database revealed 425 patients who underwent percutaneous ablation for treatment of 455 renal tumors over a 5-year time period. Imparted radiation dose information was reviewed for each procedure and converted to effective patient dose and skin dose using established techniques. Statistical analysis was performed with each ablative technique.ResultsFor the 331 cryoablation procedures, the mean DLP was 6987 mGycm (SD = 2861) resulting in a mean effective dose of 104.7 mSv (SD = 43.5) and the mean CTDI{sub vol} was 558 mGy (SD = 439) resulting in a mean skin dose of 563.2 mGy (SD = 344.1). For the 124 RFA procedures, the mean DLP was 3485 mGycm (SD = 1630) resulting in a mean effective dose of 50.3 mSv (SD = 24.0) and the mean CTDI{sub vol} was 232 mGy (SD = 149) resulting in a mean skin dose of 233.2 mGy (SD = 117.4). The difference in patient radiation exposure between the two renal ablation techniques was statistically significant (p < 0.001).ConclusionBoth cryoablation and RFA imparted an average skin dose that was well below the 2 Gy deterministic threshold for appreciable sequela. Renal tumor cryoablation resulted in a mean skin and effective radiation dose more than twice that for RFA. The radiation exposure for both renal tumor ablation techniques was at the high end of the medical imaging radiation dose spectrum.

  14. Estimation of radiofrequency power leakage from microwave ovens for dosimetric assessment at nonionizing radiation exposure levels.

    Science.gov (United States)

    Lopez-Iturri, Peio; de Miguel-Bilbao, Silvia; Aguirre, Erik; Azpilicueta, Leire; Falcone, Francisco; Ramos, Victoria

    2015-01-01

    The electromagnetic field leakage levels of nonionizing radiation from a microwave oven have been estimated within a complex indoor scenario. By employing a hybrid simulation technique, based on coupling full wave simulation with an in-house developed deterministic 3D ray launching code, estimations of the observed electric field values can be obtained for the complete indoor scenario. The microwave oven can be modeled as a time- and frequency-dependent radiating source, in which leakage, basically from the microwave oven door, is propagated along the complete indoor scenario interacting with all of the elements present in it. This method can be of aid in order to assess the impact of such devices on expected exposure levels, allowing adequate minimization strategies such as optimal location to be applied.

  15. Estimation of Radiofrequency Power Leakage from Microwave Ovens for Dosimetric Assessment at Nonionizing Radiation Exposure Levels

    Directory of Open Access Journals (Sweden)

    Peio Lopez-Iturri

    2015-01-01

    Full Text Available The electromagnetic field leakage levels of nonionizing radiation from a microwave oven have been estimated within a complex indoor scenario. By employing a hybrid simulation technique, based on coupling full wave simulation with an in-house developed deterministic 3D ray launching code, estimations of the observed electric field values can be obtained for the complete indoor scenario. The microwave oven can be modeled as a time- and frequency-dependent radiating source, in which leakage, basically from the microwave oven door, is propagated along the complete indoor scenario interacting with all of the elements present in it. This method can be of aid in order to assess the impact of such devices on expected exposure levels, allowing adequate minimization strategies such as optimal location to be applied.

  16. 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...

  17. Adverse health effects of occupational exposure to radiofrequency radiation in airport surveillance radar operators

    Directory of Open Access Journals (Sweden)

    Naser Dehghan

    2013-01-01

    Full Text Available Introduction: Radar workers are exposed to pulsed high frequency electromagnetic fields. In this study, health effects of these radiations in personnel who routinely work with radar systems are investigated. Materials and Methods: The 28-item General Health Questionnaire was used as a self-administered tool for assessment of general mental health and mental distress. One hundred workers occupationally exposed to radar radiations (14-18 GHz participated in the study. Visual reaction time was recorded with a simple blind computer-assisted-visual reaction time test. To assess the short-term memory, Wechsler Memory Scale-III test was performed. Results: Twenty to 39% of the radar workers reported different problems such as needing a good tonic, feeling run down and out of sorts, headache, tightness or pressure in the head, insomnia, getting edgy and bad-tempered. Furthermore, 47% of the radar workers reported feeling under strain. In response to this question that if they have been able to enjoy their normal day-to-day activities, 31% responded "less than usual". It was also shown that work experience had significant relationships with reaction time and short-term memory indices i.e., forward digit span, reverse digit span, word recognition and paired words. Conclusion: To the best of our knowledge, this is the first study to show that occupational exposure to radar microwave radiation leads to changes in somatic symptoms, anxiety and insomnia, social dysfunction, and severe depression. Altogether these results indicate that occupational exposure to radar microwave radiations may be linked to some adverse health effects.

  18. Effect of electromagnetic radiofrequency radiation on the rats' brain, liver and kidney cells measured by comet assay.

    Science.gov (United States)

    Trosić, Ivancica; Pavicić, Ivan; Milković-Kraus, Sanja; Mladinić, Marin; Zeljezić, Davor

    2011-12-01

    The goal of study was to evaluate DNA damage in rat's renal, liver and brain cells after in vivo exposure to radiofrequency/microwave (Rf/Mw) radiation of cellular phone frequencies range. To determine DNA damage, a single cell gel electrophoresis/comet assay was used. Wistar rats (male, 12 week old, approximate body weight 350 g) (N = 9) were exposed to the carrier frequency of 915 MHz with Global System Mobile signal modulation (GSM), power density of 2.4 W/m2, whole body average specific absorption rate SAR of 0.6 W/kg. The animals were irradiated for one hour/day, seven days/week during two weeks period. The exposure set-up was Gigahertz Transversal Electromagnetic Mode Cell (GTEM--cell). Sham irradiated controls (N = 9) were apart of the study. The body temperature was measured before and after exposure. There were no differences in temperature in between control and treated animals. Comet assay parameters such as the tail length and tail intensity were evaluated. In comparison with tail length in controls (13.5 +/- 0.7 microm), the tail was slightly elongated in brain cells of irradiated animals (14.0 +/- 0.3 microm). The tail length obtained for liver (14.5 +/- 0.3 microm) and kidney (13.9 +/- 0.5 microm) homogenates notably differs in comparison with matched sham controls (13.6 +/- 0.3 microm) and (12.9 +/- 0.9 microm). Differences in tail intensity between control and exposed animals were not significant. The results of this study suggest that, under the experimental conditions applied, repeated 915 MHz irradiation could be a cause of DNA breaks in renal and liver cells, but not affect the cell genome at the higher extent compared to the basal damage.

  19. Effect of 900 MHz radiofrequency radiation on oxidative stress in rat brain and serum.

    Science.gov (United States)

    Bilgici, Birsen; Akar, Aysegul; Avci, Bahattin; Tuncel, Ozgur Korhan

    2013-03-01

    The increasing use of mobile telephones raises the question of possible adverse effects of the electromagnetic fields (EMF) that these phones produce. In this study, we examined the oxidative stress in the brain tissue and serum of rats that resulted from exposure to a 900-MHz EMF at a whole body average specific absorption rate (SAR) of 1.08 W/kg for 1 h/day for 3 weeks. We also examined the antioxidant effect of garlic powder (500 mg/kg/day) given orally to EMF-exposed rats. We found that malondialdehyde (MDA) (p advanced oxidation protein product (AOPP) (p electromagnetic radiation (EMR) exposure and that garlic has a protective effect against this oxidative stress.

  20. Evaluation of the Interference of the Microwave Radiation Emitted from GSM Mobile Phones on the Performance of Cell Counters

    Directory of Open Access Journals (Sweden)

    Bahaedini ,N.

    2009-01-01

    Full Text Available Background and Objectives: Incidents related to electromagneticinterference with medical devices have been reported over the past decades.It has also been indicated that the microwave radiation emitted from mobilephones interferes with the operation of medical devices; therefore, this studyaimed at testing the interference by GSM mobile phones with cell counters.Material and Methods: We did this experimental Study on thirty-twoheparinized blood samples of 32 healthy individuals Selected randomly. TheCell Counting was Carried out in the presence of Electro magnetic fieldproduced by three Cell phones with different levels of SAR (Low,intermediate and High and without being in electromagnetic field.Statistical tests were used to analyze the data (p<0.05.Results: Microwave radiation emitted from cell phones, regardless of theirSAR, interferes with the proper operation of cell Counter. This interferenceleads to false Counting.Conclusion: As mobile phones emit microwave radiation in an isotropicmanner, keeping mobile phones at a safe distance, 15cm, from medicalequipments will be necessary. These observations confirm the need for somerestrictions of mobile phone use in hospitals and medical laboratories.Key words: Interference, Cell Counters, Mobile Phone, MicrowaveRadiation

  1. Radiative corrections to the semileptonic Dalitz plot with angular correlation between polarized decaying hyperons and emitted charged leptons (17 pages)

    CERN Document Server

    Flores-Mendieta, R; Martínez, A; Torres, J J; Flores-Mendieta, Ruben

    2001-01-01

    We obtain a model-independent expression for the complete Dalitz plot of semileptonic decays of polarized hyperons, which includes both the three-body and the four-body regions. We calculate radiative corrections to order alpha, neglecting terms of order alpha q/(pi M_1), where q is the four-momentum transfer and M_1 is the mass of the decaying hyperon. Our results exhibit explicitly the correlation between the emitted hyperon three-momentum and the spin of the decaying hyperon. This allows us to obtain the corresponding radiative corrections to the integrated emitted hyperon spin-asymmetry coefficient. Our formulas are valid for charged as well as for neutral decaying hyperons and are appropriate for model-independent experimental analysis whether the real photon is discriminated or not.

  2. Increased micronucleated cell frequency related to exposure to radiation emitted by computer cathode ray tube video display monitors

    OpenAIRE

    Karina Carbonari; Luciane Gonçalves; Daniela Roth; Patrick Moreira; Ricardo Fernández; Maria da Graça Martino-Roth

    2005-01-01

    It is well recognized that electromagnetic fields can affect the biological functions of living organisms at both cellular and molecular level. The potential damaging effects of electromagnetic fields and very low frequency and extremely low frequency radiation emitted by computer cathode ray tube video display monitors (VDMs) has become a concern within the scientific community. We studied the effects of occupational exposure to VDMs in 10 males and 10 females occupationally exposed to VDMs ...

  3. Assessment of magnetic field interactions and radiofrequency-radiation-induced heating of metallic spinal implants in 7 T field.

    Science.gov (United States)

    Tsukimura, Itsuko; Murakami, Hideki; Sasaki, Makoto; Endo, Hirooki; Yamabe, Daisuke; Oikawa, Ryosuke; Doita, Minoru

    2016-10-21

    The safety of metallic spinal implants in magnetic resonance imaging (MRI) performed using ultrahigh fields has not been established. Hence, we examined whether the displacement forces caused by a static magnetic field and the heating induced by radiofrequency radiation are substantial for spinal implants in a 7 T field. We investigated spinal rods of various lengths and materials, a screw, and a cross-linking bridge in accordance with the American Society for Testing and Materials guidelines. The displacement forces of the metallic implants in static 7 T and 3 T static magnetic fields were measured and compared. The temperature changes of the implants during 15-min-long fast spin-echo and balanced gradient-echo image acquisition sequences were measured in the 7 T field. The deflection angles of the metallic spinal materials in the 7 T field were 5.0-21.0° [median: 6.7°], significantly larger than those in the 3 T field (1.0-6.3° [2.2°]). Among the metallic rods, the cobalt-chrome rods had significantly larger deflection angles (17.8-21.0° [19.8°]) than the pure titanium and titanium alloy rods (5.0-7.7° [6.2°]). The temperature changes of the implants, including the cross-linked rods, were 0.7-1.0°C [0.8°C] and 0.6-1.0°C [0.7°C] during the fast spin-echo and balanced gradient-echo sequences, respectively; these changes were slightly larger than those of the controls (0.4-1.1°C [0.5°C] and 0.3-0.9°C [0.6°C], respectively). All of the metallic spinal implants exhibited small displacement forces and minimal heating, indicating that MRI examinations using 7 T fields may be performed safely on patients with these implants. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  4. Genetic damage in mammalian somatic cells exposed to radiofrequency radiation: a meta-analysis of data from 63 publications (1990-2005).

    Science.gov (United States)

    VIjayalaxmi; Prihoda, Thomas J

    2008-05-01

    During the last several decades, numerous researchers have examined the potential of in vitro and /or in vivo exposure of radiofrequency( RF) radiation to damage the genetic material in mammalian somatic cells. A meta-analysis of reported data was conducted to obtain a quantitative estimate ( with 95% confidence intervals) of genotoxicity in RF-radiation-exposed cells compared with sham-exposed/unexposed control cells. The extent of genotoxicity was assessed for various end points, including single- and double-strand breaks in the DNA, incidence of chromosomal aberrations, micronuclei and sister chromatid exchanges. Among the several variables in the experimental protocols used in individual investigations, the influence of three specific variables related to RF-radiation exposure characteristics was examined in the meta-analysis: frequency, specific absorption rate, and exposure as continuous-wave, pulsed-wave and occupationally exposed/cell phone users. The overall data indicated that (1) the difference between RF-radiation exposure was small with few exceptions; (2) at certain RF radiation exposure conditions, there were statistically significant increases in genotoxicity for some end points; and (3) the mean indices for chromosomal aberrations and micronuclei in RF-radiation -exposed and sham-/unexposed controls were within the spontaneous levels reported in the historical database. Considerable evidence for publication bias was found in the meta-analysis.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ostorero, L.; /Turin U. /INFN, Turin; Moderski, R.; /Warsaw, Copernicus Astron. Ctr. /KIPAC, Menlo Park; Stawarz, L.; /KIPAC, Menlo Park /Jagiellonian U., Astron. Observ.; Diaferio, A.; /Turin U. /INFN, Turin; Kowalska, I.; /Warsaw U. Observ.; Cheung, C.C.; /NASA, Goddard /Naval Research Lab, Wash., D.C.; Kataoka, J.; /Waseda U., RISE; Begelman, M.C.; /JILA, Boulder; Wagner, S.J.; /Heidelberg Observ.

    2010-06-07

    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 {gamma}-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{sub H}) and radio (N{sub 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.

  6. Adaptive response in mouse bone-marrow stromal cells exposed to 900-MHz radiofrequency fields: Gamma-radiation-induced DNA strand breaks and repair.

    Science.gov (United States)

    Ji, Yongxin; He, Qina; Sun, Yulong; Tong, Jian; Cao, Yi

    2016-01-01

    The aim of this study was to examine whether radiofrequency field (RF) preexposure induced adaptive responses (AR) in mouse bone-marrow stromal cells (BMSC) and the mechanisms underlying the observed findings. Cells were preexposed to 900-MHz radiofrequency fields (RF) at 120 μW/cm(2) power intensity for 4 h/d for 5 d. Some cells were subjected to 1.5 Gy γ-radiation (GR) 4 h following the last RF exposure. The intensity of strand breaks in the DNA was assessed immediately at 4 h. Subsequently, some BMSC were examined at 30, 60, 90, or 120 min utilizing the alkaline comet assay and γ-H2AX foci technique. Data showed no significant differences in number and intensity of strand breaks in DNA between RF-exposed and control cells. A significant increase in number and intensity of DNA strand breaks was noted in cells exposed to GR exposure alone. RF followed by GR exposure significantly decreased number of strand breaks and resulted in faster kinetics of repair of DNA strand breaks compared to GR alone. Thus, data suggest that RF preexposure protected cells from damage induced by GR. Evidence indicates that in RF-mediated AR more rapid repair kinetics occurs under conditions of GR-induced damage, which may be attributed to diminished DNA strand breakage.

  7. Study of effects of radio-wave frequency radiation emitted from cellular telephones on embryonic development of danio rerio

    Science.gov (United States)

    Vagula, Mary; Harkless, Ryan

    2013-05-01

    Radio wave frequency (RF) radiation emitted from cellular telephones has become increasingly ubiquitous as a result of the popularity of these phones. With the increasing and unavoidable exposure to RF radiation a reality, it is imperative that the effects of such radiation on living tissue be well understood. In particular, it is critical to understand any effects that RF radiation may have as a carcinogen and on embryonic development, as pregnant women are not exempt from such exposure. As a model organism, zebrafish (Danio rerio) have been studied extensively, and their value in studies of gene expression cannot be overstated. This study observed the effects of RF radiation on the embryonic development of zebrafish. The expression of two genes, shha and hoxb9a, that are key to the early development of the fish was examined. Both genes have homologs in humans as well as in other model organisms. Preliminary results suggest that exposure to cell phone radiation might have an effect on the expression of shha in zebrafish embryos, causing under expression. More trials are necessary to validate these results.

  8. Photoelectron Emission from Metal Surfaces Induced by Radiation Emitted by a 14 GHz Electron Cyclotron Resonance Ion Source

    CERN Document Server

    Laulainen, Janne; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli

    2015-01-01

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10 % of the estimated total electron losses from the plasma.

  9. Photoelectron emission from metal surfaces induced by radiation emitted by a 14 GHz electron cyclotron resonance ion source

    Science.gov (United States)

    Laulainen, Janne; Kalvas, Taneli; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli

    2016-02-01

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10% of the estimated total electron losses from the plasma.

  10. Photoelectron emission from metal surfaces induced by radiation emitted by a 14 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Laulainen, Janne, E-mail: janne.p.laulainen@student.jyu.fi; Kalvas, Taneli; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli [Department of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla (Finland)

    2016-02-15

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10% of the estimated total electron losses from the plasma.

  11. 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...

  12. Studying the protein expression in human B lymphoblastoid cells exposed to 1.8-GHz (GSM) radiofrequency radiation (RFR) with protein microarray.

    Science.gov (United States)

    Zhijian, Chen; Xiaoxue, Li; Wei, Zheng; Yezhen, Lu; Jianlin, Lou; Deqiang, Lu; Shijie, Chen; Lifen, Jin; Jiliang, He

    2013-03-29

    In the present study, the protein microarray was used to investigate the protein expression in human B-cell lymphoblastoid cells intermittently exposed to 1.8-GHz GSM radiofrequency radiation (RFR) at the specific absorption rate (SAR) of 2.0 W/kg for 24 h. The differential expression of 27 proteins was found, which were related to DNA damage repair, apoptosis, oncogenesis, cell cycle and proliferation (ratio >1.5-fold, P<0.05). The results validated with Western blot assay indicated that the expression of RPA32 was significantly down-regulated (P<0.05) while the expression of p73 was significantly up-regulated in RFR exposure group (P<0.05). Because of the crucial roles of those proteins in DNA repair and cell apoptosis, the results of present investigation may explain the biological effects of RFR on DNA damage/repair and cell apoptosis. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Monte Carlo simulation of the Cherenkov radiation emitted by TeO{sub 2} crystal when crossed by cosmic muons

    Energy Technology Data Exchange (ETDEWEB)

    Casali, N., E-mail: nicola.casali@gmail.com [Dipartimento di Scienze Fisiche e Chimiche, Università degli studi dell' Aquila, Coppito (AQ) (Italy); Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso, Assergi (AQ) (Italy); Bellini, F. [Sapienza Università di roma, P.le A. Moro 2, Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy); Dafinei, I. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy); Marafini, M. [Museo Storico della Fisisca e Centro Studi e Ricerche “Enrico Fermi“, Piazza del Viminale 1, Roma (Italy); Morganti, S.; Orio, F.; Pinci, D.; Vignati, M.; Voena, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy)

    2013-12-21

    TeO{sub 2} crystals are currently used as bolometric detectors in experiments searching for the neutrinoless double beta decay of {sup 130}Te. The extreme rarity of the studied signal forces the experiments to reach an ultra low background level. The main background source is represented by α particles emitted by radioactive contaminants placed in the materials that compose and surround the detector. Recent measurements show that a particle discrimination in TeO{sub 2} bolometers detecting the light emitted by β/γ particles is possible, opening the possibility to make large improvements in the performance of experiments based on this kind of materials. In order to understand the nature of this light emission a measurement at room temperature with TeO{sub 2} crystals was performed. According to these results, the detected light was compatible with the Cherenkov emission, even though the scintillation hypothesis could not be discarded. In this work a Monte Carlo (MC) simulation of the Cherenkov radiation emitted by TeO{sub 2} crystal when crossed by cosmic muons was performed. The data from MC and the room temperature measurement are perfectly compatible and prove that the Cherenkov light is the only component of the light yield of TeO{sub 2} crystals.

  14. A general analytical expression for the radiation source function of emitting and scattering media within the matrix operator method

    Science.gov (United States)

    Liu, Quanhua; Simmer, C.; Ruprecht, E.

    1991-05-01

    An analytical expression has been derived for the radiation source function for a thermally emitting and scattering medium within the Matrix-Operator-Method (MOM). The final formulation is equivalent to the one found by Aronson and Yarmush (1966), who applied the transfer matrix to gamma-ray and neutron penetration and to transport problems in slab geometry. For the thermal infrared case, the general analytical expression reduces to a simple formula, which depends only on the zenith angle. The formula is incorporated in the MOM together with analytical expressions of the transmission and reflection operators following Liu (1990). With the aid of these formulations, expressions are derived as parameterizations of the scattering effects of clouds in nonscattering radiative transfer models by a modification of the emissivity and transmittance of clouds. The accuracy is better than 0.5 percent in the 11.5 micron window region for clouds of arbitrary optical depths.

  15. Chromosome damage and micronucleus formation in human blood lymphocytes exposed in vitro to radiofrequency radiation at a cellular telephone frequency (847.74 MHz, CDMA).

    Science.gov (United States)

    Vijayalaxmi; Bisht, K S; Pickard, W F; Meltz, M L; Roti Roti, J L; Moros, E G

    2001-10-01

    Peripheral blood samples collected from four healthy nonsmoking human volunteers were diluted with tissue culture medium and exposed in vitro for 24 h to 847.74 MHz radiofrequency (RF) radiation (continuous wave), a frequency employed for cellular telephone communications. A code division multiple access (CDMA) technology was used with a nominal net forward power of 75 W and a nominal power density of 950 W/m(2) (95 mW/cm(2)). The mean specific absorption rate (SAR) was 4.9 or 5.5 W/kg. Blood aliquots that were sham-exposed or exposed in vitro to an acute dose of 1.5 Gy of gamma radiation were included in the study as controls. The temperatures of the medium during RF-radiation and sham exposures in the Radial Transmission Line facility were controlled at 37 +/- 0.3 degrees C. Immediately after the exposures, lymphocytes were cultured at 37 +/- 1 degrees C for 48 or 72 h. The extent of genetic damage was assessed from the incidence of chromosome aberrations and micronuclei. 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-exposed and sham-exposed lymphocytes with respect to mitotic indices, frequencies of exchange aberrations, excess fragments, binucleate cells, and micronuclei. The response of gamma-irradiated lymphocytes was significantly different from that of both RF-radiation-exposed and sham-exposed cells for all of these indices. Thus there was no evidence for induction of chromosome aberrations and micronuclei in human blood lymphocytes exposed in vitro for 24 h to 847.74 MHz RF radiation (CDMA) at SARs of 4.9 or 5.5 W/kg.

  16. Childhood leukaemia in relation to radiofrequency electromagnetic fields emitted from television and radio broadcast transmitters: epidemiological aspects of a case-control study in Germany; Leukaemie bei Kindern in der Umgebung von Sendestationen des Rundfunks. Anforderungen an das Studiendesign

    Energy Technology Data Exchange (ETDEWEB)

    Merzenich, H.; Bennack, S.; Blettner, M. [Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Schmiedel, S.; Schuez, J. [Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Danish Cancer Society, Copenhagen (Denmark). Inst. of Cancer Epidemiology; Brueggemeyer, H. [Niedersaechsischer Landesbetrieb fuer Wasserwirtschaft, Kuesten- und Naturschutz, AB35 - Strahlenschutz in Niedersachsen, Hannover (Germany); Philipp, J. [Suedwestrundfunk, Stuttgart (Germany). Abt. Frequenz- und Versorgungsplanung; Spix, C. [Mainz Univ. (Germany). Deutsches Kinderkrebsregister

    2007-07-01

    Leukaemia is the most common type of cancer in children accounting for about a third of all cancers in children under the age of 15 years. Environmental factors such as non-ionising radiation exposure might play a role in the aetiology of childhood leukaemia. However, data to support such hypotheses are inconsistent. A case control study has been set up in West Germany (University of Mainz) in order to determine whether there is an increased risk of childhood leukaemia in populations exposed to radiofrequency electromagnetic fields from TV and/or Radio towers. Cases are children aged 0 to 14 years with a primary leukaemia diagnosed between 1984 and 2003 who lived in the vicinity of these TV- and/ or Radio towers. Cases have been identified through the German Childhood Cancer Registry. Three controls per case have been individually matched by age at diagnosis, sex, time of diagnosis and study area. The study focuses on an individual retrospective exposure assessment using data from transmitter network operators. The study has started in March 2005 with a pilot investigation in order to specify the study design and the methods for exposure assessment. A total of 2009 eligible cases have been identified. The study will be finished end of 2007. (orig.)

  17. 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.

  18. 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.)

  19. The effect of chronic exposure to 835.62 MHz FDMA or 847.74 MHz CDMA radiofrequency radiation on the incidence of spontaneous tumors in rats.

    Science.gov (United States)

    La Regina, Marie; Moros, Eduardo G; Pickard, William F; Straube, William L; Baty, Jack; Roti Roti, Joseph L

    2003-08-01

    This study was designed to determine whether chronic exposure to radiofrequency (RF) radiation from cellular phones increased the incidence of spontaneous tumors in F344 rats. Eighty male and 80 female rats were randomly placed in each of three irradiation groups. The sham group received no irradiation; the Frequency Division Multiple Access (FDMA) group was exposed to 835.62 MHz FDMA RF radiation; and the Code Division Multiple Access (CDMA) group was exposed to 847.74 MHz CDMA RF radiation. Rats were irradiated 4 h per day, 5 days per week over 2 years. The nominal time-averaged specific absorption rate (SAR) in the brain for the irradiated animals was 0.85 +/- 0.34 W/kg (mean +/- SD) per time-averaged watt of antenna power. Antennas were driven with a time-averaged power of 1.50 +/- 0.25 W (range). That is, the nominal time-averaged brain SAR was 1.3 +/- 0.5 W/kg (mean +/- SD). This number was an average from several measurement locations inside the brain, and it takes into account changes in animal weight and head position during irradiation. All major organs were evaluated grossly and histologically. The number of tumors, tumor types and incidence of hyperplasia for each organ were recorded. There were no significant differences among final body weights or survival days for either males or females in any group. No significant differences were found between treated and sham-exposed animals for any tumor in any organ. We conclude that chronic exposure to 835.62 MHz FDMA or 847.74 MHz CDMA RF radiation had no significant effect on the incidence of spontaneous tumors in F344 rats.

  20. 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

    2017-06-01

    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.

  1. High-power terahertz radiation from surface-emitted THz-wave parametric oscillator

    Institute of Scientific and Technical Information of China (English)

    Li Zhong-Yang; Yao Jian-Quan; Xu De-Gang; Zhong Kai; Wang Jing-Li; Bing Pi-Bin

    2011-01-01

    We report a pulsed surface-emitted THz-wave parametric oscillator based on two MgO:LiNbC>3 crystals pumped by a multi-longitudinal mode Q-switched Nd:YAG laser. Through varying the phase matching angle, the tunable THz wave output from 0.79 THz to 2.84 THz is realized. The maximum THz-wave output was 193.2 nJ/pulse at 1.84 THz as the pump power density was 212.5 MW/cm2, corresponding to the energy conversion efficiency of 2.42 ×10-6 and the photon conversion efficiency of about 0.037%. When the pump power density changed from 123 MW/cm2 to 148 MW/cm2 and 164 MW/cm2, the maximum output of the THz-wave moved to the high frequency band. We give a reasonable explanation for this phenomenon.

  2. Yields of positron and positron emitting nuclei for proton and carbon ion radiation therapy: a simulation study with GEANT4.

    Science.gov (United States)

    Lau, Andy; Chen, Yong; Ahmad, Salahuddin

    2012-01-01

    A Monte Carlo application is developed to investigate the yields of positron-emitting nuclei (PEN) used for proton and carbon ion range verification techniques using the GEANT4 Toolkit. A base physics list was constructed and used to simulate incident proton and carbon ions onto a PMMA or water phantom using pencil like beams. In each simulation the total yields of PEN are counted and both the PEN and their associated positron depth-distributions were recorded and compared to the incident radiation's Bragg Peak. Alterations to the physics lists are then performed to investigate the PEN yields dependence on the choice of physics list. In our study, we conclude that the yields of PEN can be estimated using the physics list presented here for range verification of incident proton and carbon ions.

  3. Ag-Ag2S/reduced graphene oxide hybrids used as long-wave UV radiation emitting nanocomposites

    Science.gov (United States)

    Li, Wenyao; Xu, Ruoyu; Ling, Min; He, Guanjie

    2017-10-01

    We report a facile thermal decomposition approach to synthesize Ag-Ag2S/reduced graphene oxide (Ag-Ag2S/rGO), the Ag-Ag2S nanoparticles uniformly dispersed on reduced graphene oxide with diameters of 10-20 nm. The photoluminescence spectra of Ag-Ag2S/rGO showed two obvious emission peaks at 327 and 339 nm with the excitation wavelength at 287 nm. Compared with Ag-Ag2S heterostructured clusters with two peaks at 407 and 430 nm, it showed a big blue shift and higher intensity, which makes it a novel candidate for long-wave UV radiation emitting nanocomposite.

  4. Frequency-dependent radiation patterns emitted by THz plasmons on finite length cylindrical metal wires

    NARCIS (Netherlands)

    Deibel, J.A.; Berndsen, N.; Wang, K.; Mittleman, D.M.; Van der Valk, N.C.J.; Planken, P.C.M.

    2006-01-01

    We report on the emission patterns from THz plasmons propagating towards the end of cylindrical metal waveguides. Such waveguides exhibit low loss and dispersion, but little is known about the dynamics of the terahertz radiation at the end of the waveguide, specifically in the near- and intermediate

  5. Evaluation of Possible Methods and Approaches for Registering of Non-Ionizing Radiation Emitted from the Human Body

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov

    2015-06-01

    Full Text Available This paper presents the results of evaluation of possible biophysical methods and approaches for registering of various non-ionizing radiation (NIR wave types of the human body in the optic and electromagnetic range. Various types of NIR (electromagnetic waves, infrared radiation, thermo radiation, bioluminiscence emitted from the human body were reviewed. In particular the results on the spontaneous biophoton emission and the delayed luminescence from the human body were submitted along with infrared thermography (IRT results. It was shown that 1 cm2 of skin generally emits 85 photons for 1 s. The intensity of biophoton emission ranges from 10−19 to 10−16 W/cm2 (approx. 1–1000 photons.cm-2.s-1. The specific bioluminiscence emission from part of the human thumb was detected as a spectrum of various colours with the method of Colour coronal spectral analysis on a device with an electrode made of polyethylene terephthalate (PET hostaphan with applied electric voltage 15 kV, electric impulse duration 10 s, and electric current frequency 15 kHz. It was established that photons corresponding to a red color emission of visible electromagnetic spectrum have energy at 1,82 еV. The orange color of visible electromagnetic spectrum has energy at 2,05 eV, yellow – 2,14 eV, blue-green (cyan – 2,43 eV, blue – 2,64 eV, and violet – 3,03 eV. The reliable result measurement norm was at E ≥ 2,53 eV, while the spectral range of the emission was within  = 380–495±5 nm and  = 570–750±5 nm. Also were estimated some important physical characteristics (energy of hydrogen bonds, wetting angle, surface tension of water by the methods of non-equilibrium energy (NES and differential non-equilibrium energy (DNES spectrum of water, that helps understand in general how electromagnetic radiation interacts with water and establish the structural characteristics of water.

  6. Medicina array demonstrator: calibration and radiation pattern characterization using a UAV-mounted radio-frequency source

    Science.gov (United States)

    Pupillo, G.; Naldi, G.; Bianchi, G.; Mattana, A.; Monari, J.; Perini, F.; Poloni, M.; Schiaffino, M.; Bolli, P.; Lingua, A.; Aicardi, I.; Bendea, H.; Maschio, P.; Piras, M.; Virone, G.; Paonessa, F.; Farooqui, Z.; Tibaldi, A.; Addamo, G.; Peverini, O. A.; Tascone, R.; Wijnholds, S. J.

    2015-06-01

    One of the most challenging aspects of the new-generation Low-Frequency Aperture Array (LFAA) radio telescopes is instrument calibration. The operational LOw-Frequency ARray (LOFAR) instrument and the future LFAA element of the Square Kilometre Array (SKA) require advanced calibration techniques to reach the expected outstanding performance. In this framework, a small array, called Medicina Array Demonstrator (MAD), has been designed and installed in Italy to provide a test bench for antenna characterization and calibration techniques based on a flying artificial test source. A radio-frequency tone is transmitted through a dipole antenna mounted on a micro Unmanned Aerial Vehicle (UAV) (hexacopter) and received by each element of the array. A modern digital FPGA-based back-end is responsible for both data-acquisition and data-reduction. A simple amplitude and phase equalization algorithm is exploited for array calibration owing to the high stability and accuracy of the developed artificial test source. Both the measured embedded element patterns and calibrated array patterns are found to be in good agreement with the simulated data. The successful measurement campaign has demonstrated that a UAV-mounted test source provides a means to accurately validate and calibrate the full-polarized response of an antenna/array in operating conditions, including consequently effects like mutual coupling between the array elements and contribution of the environment to the antenna patterns. A similar system can therefore find a future application in the SKA-LFAA context.

  7. Angular measurement of the cobalt-60 emitted radiation spectrum from a radiosurgery irradiator.

    Science.gov (United States)

    Drzymala, R E; Sohn, J W; Guo, C; Sobotka, L G; Purdy, J A

    2001-04-01

    The photon energy spectrum emanating from a Leksell Gamma Knife, Model 23004B, was measured between 0.250 and 3.5 MeV with the sources exposed. Measurements were made using a 2x2 inch NaI detector enclosed in a lead-shielded apparatus having a 1/4 inch diameter measurement aperture, which reduced the amount of radiation received by the crystal. All measurements were made one meter above the floor within a quadrant toward one side of the Gamma Knife couch. The measured spectra displayed the expected 60Co doublet of photon peaks at energies of 1.17 and 1.33 MeV. These peaks appeared in spectra beginning at approximately 50 degrees, as one proceeds from a point directly lateral to the source enclosure (0 degrees) toward the foot of the couch (90 degrees). The average photon energy of the spectrum shifts to lower values as the doublet decreases in magnitude with increasing angle until almost vanishing at an angle equal to 90 degrees. Inserting a 16 cm diameter plastic sphere phantom, provided with the Gamma Knife, into the radiation beams increases the low energy photon emissions appearing in the spectrum, especially for measurements at the foot of the couch. Implications for the design of shielding a treatment room containing the Gamma Knife, Model B, and estimation of the radiation exposure to personnel during an emergency procedure in the treatment room with the sources exposed are discussed.

  8. Single electron detection and spectroscopy via relativistic cyclotron radiation

    CERN Document Server

    Asner, D M; de Viveiros, L; Doe, P J; Fernandes, J L; Fertl, M; Finn, E C; Formaggio, J A; Furse, D; Jones, A M; Kofron, J N; LaRoque, B H; Leber, M; McBride, E L; Miller, M L; Mohanmurthy, P; Monreal, B; Oblath, N S; Robertson, R G H; Rosenberg, L J; Rybka, G; Rysewyk, D; Sternberg, M G; Tedeschi, J R; Thummler, T; VanDevender, B A; Woods, N L

    2014-01-01

    It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spec- trometer. We observe the cyclotron radiation emitted by individual magnetically-trapped electrons that are produced with mildly-relativistic energies by a gaseous radioactive source. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta elec- tron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work demonstrates a fundamentally new approach to precision beta sp...

  9. Single-electron detection and spectroscopy via relativistic cyclotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Asner, David M.; Bradley, Rich; De Viveiros Souza Filho, Luiz A.; Doe, Peter J.; Fernandes, Justin L.; Fertl, M.; Finn, Erin C.; Formaggio, Joseph; Furse, Daniel L.; Jones, Anthony M.; Kofron, Jared N.; LaRoque, Benjamin; Leber, Michelle; MCBride, Lisa; Miller, M. L.; Mohanmurthy, Prajwal T.; Monreal, Ben; Oblath, Noah S.; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Rysewyk, Devyn M.; Sternberg, Michael G.; Tedeschi, Jonathan R.; Thummler, Thomas; VanDevender, Brent A.; Woods, N. L.

    2015-04-01

    It has been understood since 1897 that accelerating charges should emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spectrometer. We observe the cyclotron radiation emitted by individual electrons that are produced with mildly-relativistic energies by a gaseous radioactive source and are magnetically trapped. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work is a proof-of-concept for future neutrino mass experiments using this technique.

  10. 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.

  11. Radiation Damage Effects in Heterostructure Light Emitting Diodes (HLEDs under Proton Irradiation Fields

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-05-01

    Full Text Available In the present paper, we have been analyzed the high temperature variations testing in order to be used to determine light emitting diode lifetime, even though laser diode failure mechanisms are more sensitive to increases in current density. As a measured parameter of degradation, the current density is of great significance when searching for failure modes in a laser diode. Raising the current density however, is not really indicative of lifetime since it is more likely a situation to be avoided than one that simulates normal lifetime degradation. The reliability of semiconductor sources is very dependent on the degradation modes. This paper has investigated some of the degradation modes and capabilities of typical LEDs currently used in many communication and sensing systems over wide range of the affecting parameters. LED’s are typically used in multimode transmission systems where data rates no larger than 50 Mbit/sec are required. They have larger spectral widths and can add to the problem of dispersion in communications systems. Laser diodes are used in systems that require coherent and often single mode light such as high data rate communications and sensing applications.

  12. 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.

  13. Transmission of Moessbauer rays through ferromagnets in radio-frequency magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Dzyublik, A. Ya., E-mail: dzyublik@ukr.net [Institute for Nuclear Research (Ukraine); Sadykov, E. K. [Kazan (Volga region) Federal University (Russian Federation); Petrov, G. I. [Kazan State Power Engineering University (Russian Federation); Arinin, V. V.; Vagizov, F. G. [Kazan (Volga region) Federal University (Russian Federation); Spivak, V. Yu. [Institute for Nuclear Research (Ukraine)

    2013-08-15

    The transmission of Moessbauer 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 Moessbauer forward scattering (FS) spectra of the weak ferromagnet FeBO{sub 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.

  14. Radiative Forcing Due to Major Aerosol Emitting Sectors in China and India

    Science.gov (United States)

    Streets, David G.; Shindell, Drew Todd; Lu, Zifeng; Faluvegi, Greg

    2013-01-01

    Understanding the radiative forcing caused by anthropogenic aerosol sources is essential for making effective emission control decisions to mitigate climate change. We examined the net direct plus indirect radiative forcing caused by carbonaceous aerosol and sulfur emissions in key sectors of China and India using the GISS-E2 chemistry-climate model. Diesel trucks and buses (67 mW/ sq. m) and residential biofuel combustion (52 mW/ sq. m) in India have the largest global mean, annual average forcings due mainly to the direct and indirect effects of BC. Emissions from these two sectors in China have near-zero net global forcings. Coal-fired power plants in both countries exert a negative forcing of about -30 mW/ sq. m from production of sulfate. Aerosol forcings are largest locally, with direct forcings due to residential biofuel combustion of 580 mW/ sq. m over India and 416 mW/ sq. m over China, but they extend as far as North America, Europe, and the Arctic

  15. Studying the protein expression in human B lymphoblastoid cells exposed to 1.8-GHz (GSM) radiofrequency radiation (RFR) with protein microarray

    Energy Technology Data Exchange (ETDEWEB)

    Zhijian, Chen [Department of Environmental and Occupational Health, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang (China); Institute of Environmental Health, Medical College, Zhejiang University, Hangzhou 310058, Zhejiang (China); Xiaoxue, Li [Institute of Environmental Health, Medical College, Zhejiang University, Hangzhou 310058, Zhejiang (China); Wei, Zheng [Zhejiang International Travel Healthcare Center, 230 Zhonghezhong Road, Hangzhou 310003 (China); Yezhen, Lu; Jianlin, Lou; Deqiang, Lu; Shijie, Chen; Lifen, Jin [Institute of Environmental Health, Medical College, Zhejiang University, Hangzhou 310058, Zhejiang (China); Jiliang, He, E-mail: he_jiliang@hotmail.com [Institute of Environmental Health, Medical College, Zhejiang University, Hangzhou 310058, Zhejiang (China)

    2013-03-29

    Highlights: ► Protein microarray shows the differential expression of 27 proteins induced by RFR. ► RPA32 related to DNA repair is down-regulated in Western blot. ► p73 related to cell genome stability and apoptosis is up-regulated in Western blot. -- Abstract: In the present study, the protein microarray was used to investigate the protein expression in human B-cell lymphoblastoid cells intermittently exposed to 1.8-GHz GSM radiofrequency radiation (RFR) at the specific absorption rate (SAR) of 2.0 W/kg for 24 h. The differential expression of 27 proteins was found, which were related to DNA damage repair, apoptosis, oncogenesis, cell cycle and proliferation (ratio >1.5-fold, P < 0.05). The results validated with Western blot assay indicated that the expression of RPA32 was significantly down-regulated (P < 0.05) while the expression of p73 was significantly up-regulated in RFR exposure group (P < 0.05). Because of the crucial roles of those proteins in DNA repair and cell apoptosis, the results of present investigation may explain the biological effects of RFR on DNA damage/repair and cell apoptosis.

  16. Influence of 1.8-GHz (GSM) radiofrequency radiation (RFR) on DNA damage and repair induced by X-rays in human leukocytes in vitro.

    Science.gov (United States)

    Zhijian, Chen; Xiaoxue, Li; Yezhen, Lu; Deqiang, Lu; Shijie, Chen; Lifen, Jin; Jianlin, Lou; Jiliang, He

    2009-01-01

    In the present study, the in vitro comet assay was used to determine whether 1.8-GHz radiofrequency radiation (RFR) can influence DNA repair in human leukocytes exposed to X-rays. The specific energy absorption rate (SAR) of 2 W/kg (the current European safety limit) was applied. The leukocytes from four young healthy donors were intermittently exposed to RFR for 24 h (fields on for 5 min, fields off for 10 min), and then irradiated with X-rays at doses of 0.25, 0.5, 1.0 and 2.0 Gy. DNA damage to human leukocytes was detected using the comet assay at 0, 15, 45, 90, 150 and 240 min after exposure to X-rays. Using the comet assay, the percent of DNA in the tail (% tail DNA) served as the indicator of DNA damage; the DNA repair percentage (DRP) served as the indicator of the DNA repair speed. The results demonstrated that (1) the DNA repair speeds of human leukocytes after X-ray exposure exhibited individual differences among the four donors; (2) the intermittent exposures of 1.8-GHz RFR at the SAR of 2 W/kg for 24 h did not directly induce DNA damage or exhibit synergistic effects with X-rays on human leukocytes.

  17. 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.

  18. 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.

  19. Efficient and robust method for simultaneous reconstruction of the temperature distribution and radiative properties in absorbing, emitting, and scattering media

    Science.gov (United States)

    Niu, Chun-Yang; Qi, Hong; Huang, Xing; Ruan, Li-Ming; Tan, He-Ping

    2016-11-01

    A rapid computational method called generalized sourced multi-flux method (GSMFM) was developed to simulate outgoing radiative intensities in arbitrary directions at the boundary surfaces of absorbing, emitting, and scattering media which were served as input for the inverse analysis. A hybrid least-square QR decomposition-stochastic particle swarm optimization (LSQR-SPSO) algorithm based on the forward GSMFM solution was developed to simultaneously reconstruct multi-dimensional temperature distribution and absorption and scattering coefficients of the cylindrical participating media. The retrieval results for axisymmetric temperature distribution and non-axisymmetric temperature distribution indicated that the temperature distribution and scattering and absorption coefficients could be retrieved accurately using the LSQR-SPSO algorithm even with noisy data. Moreover, the influences of extinction coefficient and scattering albedo on the accuracy of the estimation were investigated, and the results suggested that the reconstruction accuracy decreased with the increase of extinction coefficient and the scattering albedo. Finally, a non-contact measurement platform of flame temperature field based on the light field imaging was set up to validate the reconstruction model experimentally.

  20. Increased micronucleated cell frequency related to exposure to radiation emitted by computer cathode ray tube video display monitors

    Directory of Open Access Journals (Sweden)

    Carbonari Karina

    2005-01-01

    Full Text Available It is well recognized that electromagnetic fields can affect the biological functions of living organisms at both cellular and molecular level. The potential damaging effects of electromagnetic fields and very low frequency and extremely low frequency radiation emitted by computer cathode ray tube video display monitors (VDMs has become a concern within the scientific community. We studied the effects of occupational exposure to VDMs in 10 males and 10 females occupationally exposed to VDMs and 20 unexposed control subjects matched for age and sex. Genetic damage was assessed by examining the frequency of micronuclei in exfoliated buccal cells and the frequency of other nuclear abnormalities such as binucleated and broken egg cells. Although there were no differences regarding binucleated cells between exposed and control individuals our analysis revealed a significantly higher frequency of micronuclei (p < 0.001 and broken egg cells (p < 0.05 in individuals exposed to VDMs as compared to unexposed. We also found that the differences between individuals exposed to VDMs were significantly related to the sex of the individuals and that there was an increase in skin, central nervous system and ocular disease in the exposed individuals. These preliminary results indicate that microcomputer workers exposed to VDMs are at risk of significant cytogenetic damage and should periodically undergo biological monitoring.

  1. IEEE Committee on Man and Radiation--COMAR technical information statement radiofrequency safety and utility Smart Meters.

    Science.gov (United States)

    Bushberg, Jerrold T; Foster, Kenneth R; Hatfield, James B; Thansandote, Arthur; Tell, Richard A

    2015-03-01

    This Technical Information Statement describes Smart Meter technology as used with modern electric power metering systems and focuses on the radio frequency (RF) emissions associated with their operation relative to human RF exposure limits. Smart Meters typically employ low power (-1 W or less) transmitters that wirelessly send electric energy usage data to the utility company several times per day in the form of brief, pulsed emissions in the unlicensed frequency bands of 902-928 MHz and 2.4-2.48 GHz or on other nearby frequencies. Most Smart Meters operate as wireless mesh networks where each Smart Meter can communicate with other neighboring meters to relay data to a data collection point in the region. This communication process includes RF emissions from Smart Meters representing energy usage as well as the relaying of data from other meters and emissions associated with maintaining the meter's hierarchy within the wireless network. As a consequence, most Smart Meters emit RF pulses throughout the day, more at certain times and less at others. However, the duty cycle associated with all of these emissions is very small, typically less than 1%, and most of the time far less than 1%, meaning that most Smart Meters actually transmit RF fields for only a few minutes per day at most. The low peak power of Smart Meters and the very low duty cycles lead to the fact that accessible RF fields near Smart Meters are far below both U.S. and international RF safety limits whether judged on the basis of instantaneous peak power densities or time-averaged exposures. This conclusion holds for Smart Meters alone or installed in large banks of meters.

  2. Impact of 1.8-GHz radiofrequency radiation (RFR) on DNA damage and repair induced by doxorubicin in human B-cell lymphoblastoid cells.

    Science.gov (United States)

    Zhijian, Chen; Xiaoxue, Li; Yezhen, Lu; Shijie, Chen; Lifen, Jin; Jianlin, Lou; Deqiang, Lu; Jiliang, He

    2010-01-01

    In the present in vitro study, a comet assay was used to determine whether 1.8-GHz radiofrequency radiation (RFR, SAR of 2W/kg) can influence DNA repair in human B-cell lymphoblastoid cells exposed to doxorubicin (DOX) at the doses of 0microg/ml, 0.05microg/ml, 0.075microg/ml, 0.10microg/ml, 0.15microg/ml and 0.20microg/ml. The combinative exposures to RFR with DOX were divided into five categories. DNA damage was detected at 0h, 6h, 12h, 18h and 24h after exposure to DOX via the comet assay, and the percent of DNA in the tail (% tail DNA) served as the indicator of DNA damage. The results demonstrated that (1) RFR could not directly induce DNA damage of human B-cell lymphoblastoid cells; (2) DOX could significantly induce DNA damage of human B-cell lymphoblastoid cells with the dose-effect relationship, and there were special repair characteristics of DNA damage induced by DOX; (3) E-E-E type (exposure to RFR for 2h, then simultaneous exposure to RFR and DOX, and exposure to RFR for 6h, 12h, 18h and 24h after exposure to DOX) combinative exposure could obviously influence DNA repair at 6h and 12h after exposure to DOX for four DOX doses (0.075microg/ml, 0.10microg/ml, 0.15microg/ml and 0.20microg/ml) in human B-cell lymphoblastoid cells. Copyright 2009 Elsevier B.V. All rights reserved.

  3. 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.

  4. An Evaluation of the Nonlinearity Correction Applied to Atmospheric Emitted Radiance Interferometer (AERI) Data Collected by the Atmospheric Radiation Measurement Program

    Energy Technology Data Exchange (ETDEWEB)

    Turner, D. D. [National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.; Knuteson, R. O. [Univ. of Wisconsin, Madison, WI (United States); Revercomb, H. E. [Univ. of Wisconsin, Madison, WI (United States); Dedecker, R. G. [Univ. of Wisconsin, Madison, WI (United States); Feltz, W. F. [Univ. of Wisconsin, Madison, WI (United States)

    2004-09-01

    Mercury Cadmium Telluride (MCT) detectors provide excellent sensitivity to infrared radiation and are used in passive infrared remote sensors such as the Atmospheric Emitted Radiance Interferometer (AERI). However, MCT detectors have a nonlinear response and thus this nonlinearity must be characterized and corrected to provide accurate infrared radiance observations. This paper discusses the significance of the nonlinearity correction applied to AERI data and its impacts on the parameters retrieved from the AERI spectra. It also evaluates the accuracy of the scheme used to determine the nonlinearity of the MCT detectors used in the Atmospheric Radiation Measurement (ARM) Program’s AERIs.

  5. 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

  6. Evaluation of exposure to electromagnetic radiofrequency radiation in the indoor workplace accessible to the public by the use of frequency-selective exposimeters

    Directory of Open Access Journals (Sweden)

    Krzysztof Gryz

    2014-12-01

    Full Text Available Objectives: The aim of the study was to identify and assess electromagnetic radiofrequency radiation (EMRR exposure in a workplace located in a publicly accessible environment, and represented by offices (where exposure is caused by various transmitters of local fixed indoor and outdoor wireless communication systems. Material and Methods: The investigations were performed in 45 buildings (in urban and rural areas in various regions of Poland, using frequency-selective electric field strength (E-field exposimeters sensitive to the EMRR with a frequency range of 88–2500 MHz, split into 12 subbands corresponding to the operating frequencies of typical EMRR sources. The variability of the E-field was analyzed for each frequency range and the total level of exposure by statistical parameters of recorded exposimetric profiles: minimum, maximum, median values and 25–75th – percentiles. Results: The main sources of exposure to EMRR are mobile phone base transceiver stations (BTS and radio-television transmitters (RTV. The frequency composition in a particular office depends on the building’s location. The E-field recorded in buildings in urban and rural areas from the outdoor BTS did not exceed respectively: medians – 0.19 and 0.05 V/m, 75th percentiles – 0.25 and 0.09 V/m. In buildings equipped with the indoor BTS antennas the E-field did not exceed: medians – 1 V/m, 75th percentiles – 1.8 V/m. Whereas in urban and rural areas, the median and 75th percentile values of the E-field recorded in buildings located near the RTV (within 1 km did not exceed: 1.5 and 3.8 V/m or 0.4 and 0.8 V/m, for radio FM band or for TV bands, respectively. Conclusions: Investigations confirmed the practical applicability of the exposimetric measurements technique for evaluating parameters of worker’s exposure in both frequency- and time-domain. The presented results show EMRR exposure of workers or general public in locations comparable to offices to be

  7. Controlling non-radiative energy transfer in organic binary blends: a route towards colour tunability and white emission from single-active-layer light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Pisignano, Dario [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy); Mazzeo, Marco [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy); Gigli, Giuseppe [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy); Barbarella, Giovanna [Consiglio Nazionale delle Ricerche (CNR), ICOCEA, Area della Ricerca di Bologna, via Gobetti 101, I-40129 Bologna (Italy); Favaretto, Laura [Consiglio Nazionale delle Ricerche (CNR), ICOCEA, Area della Ricerca di Bologna, via Gobetti 101, I-40129 Bologna (Italy); Cingolani, Roberto [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy)

    2003-10-21

    We show how colour tunability (including white) can be achieved by controlling non-radiative intermolecular energy transfer from the donor to the acceptor in binary blends of oligomeric compounds. Blends of different concentrations of a novel functionalized thiophene-based oligomer and a low-molar-mass diamine derivative (N, N'-diphenyl-N, N'-bis(3-methylphenyl)-1, 1'-biphenyl-4.4'diamine) are used to tune both the photoluminescence and the electroluminescence (EL) from red to blue, including balanced white, according to the standards of the Commission Internationale de l'Eclairage. The single-active-layer light-emitting devices, realized by spin-coating, exhibit good EL performance. In particular, the white-emitting device shows an EL efficiency of 5 x 10{sup -1} cd A{sup -1} and a luminance of more than 180 cd m{sup -2}.

  8. 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.

  9. Experimental study of the radiation emitted by 180-GeV/c electrons and positrons volume-reflected in a bent crystal

    CERN Document Server

    Scandale, Walter; Baricordi, S; Dalpiaz, P; Fiorini, M; Guidi, V; Mazzolari, A; Della Mea, G; Milan, R; Ambrosi, G; Zuccon, P; Bertucci, B; Bürger, W; Duranti, M; Cavoto, G; Santacesaria, R; Valente, P; Luci, C; Iacoangeli, F; Vallazza, E; Afonin, A G; Chesnokov, Yu A; Kotov, V I; Maisheev, V A; Yazynin, I A; Kovalenko, A D; Taratin, A M; Denisov, A S; Gavrikov, Y A; Ivanov, Yu M; Lapina, L P; Malyarenko, L G; Skorogobogatov, V V; Suvorov, V M; Vavilov, S A; Bolognini, D; Hasan, S; Mozzanica, A; Prest, M

    2009-01-01

    The radiation emitted by 180-GeV/c volume-reflected electrons and positrons impinging on a bent crystal has been measured by the H8RD22 Collaboration on the H8 beamline at the CERN SPS. A dedicated spectrometer has been developed to measure high-energy photon spectra (up to ~100 GeV) under volume reflection: photon and charged particle beams have been separated by a bending magnet and leptons were detected and tagged by microstrip silicon detectors and a Pb-scintillator sampling calorimeter. A comparison between the experimental and analytical data for the amorphous and volume-reflection cases is presented and the differences are discussed.

  10. Reducing the in-vitro electromagnetic field effect of cellular phones on human DNA and the intensity of their emitted radiation.

    Science.gov (United States)

    Syldona, Maria

    2007-01-01

    Several studies have demonstrated detrimental effects of cellular phone radiation on in-vitro biological systems. This article introduces a novel in-vitro method for demonstrating conformational changes in human DNA induced by a 5 minute exposure to cellular phone radiation emitted by an actual contemporary cellular phone. Dynamic changes in DNA conformation was determined in real-time by measuring the rate of DNA rewinding (in a spectrophotometer) following exposure to heat which causes the unwinding of the two strands of the helix. Cellular phone radiation produced a 40% increase in the rate of DNA rewinding. This effect was 95% attenuated when the experiment was repeated with the same cellular phone to which was attached a commercially available shielding disk shaped sheet containing a paramagnetic mineral. In a separate series of experiments the intensity of the cellular phone radiation was measured using an electromagnetic frequency spectrum analyzer. The intensity was reduced by approximately 50% in the presence of the shielding disk. Taken together these studies indicate the efficacy of a shielding disk to protect the body from cellular phone radiation.

  11. 强脉冲光及射频对BALB/c小鼠皮肤胶原的影响%Effects of intense pulsed light and radiofrequency radiation on the content of collagen in BALB/c mouse skin

    Institute of Scientific and Technical Information of China (English)

    潘敏; 蒋艺

    2012-01-01

    Objective To investigate the effects of intense pulsed light (IPL) and radiofrequency radiation on the appearance,histopathological manifestation,dermal depth and collagen content in BALB/c mouse skin.Methods The back of BALB/c mice was irradiated with intense pulsed light (IPL group,n =9),radiofrequency (RF group,N =9),IPL and radiofrequency (IPL+RF group,n =9) respectively,for 4 sessions at 1-week intervals followed by 2 sessions at 2-week intervals.Three mice remaining untreated served as the control group.The appearance of skin on the back of mice was observed at different time points after irradiation.Some mice were sacrificed and skin specimens were obtained from the back at week 4,8 and 12 after the first irradiation.Hematoxylin and eosin staining was performed to observe the histopathological manifestation and measure the dermal depth of mouse skin,and Masson staining to detect the expression of collagen fiber in mouse skin.Results No local adverse effects were observed in the back skin of mice after irradiation with IPL or radiofrequency.Since the 8th week after the first irradiation,the dermal layer had appeared to be thickened,with an increase in the content of collagen fiber and extraeellular matrix,in the IPL group,RF group and IPL+ RF group compared witb the control group,and the increase was more obvious in the IPL+RF group than in the IPL group and RF group (all P < 0.05 ).Increased collagen fiber was densely arranged in irradiated mice.There was no apparent thickening of skin epidermis after irradiation.Conclusions Both IPL and radiofrequency can stimulate an increase in dermal collagen production in mice,and a synergistic effect exists between IPL and radiofrequency in the biostimulation of collagen synthesis.%目的 探讨强脉冲光和射频对BALB/c小鼠皮肤的外观不良反应、组织病理、真皮厚度变化及胶原含量的影响.方法 将BALB/c小鼠随机分为强脉冲光照射组(IPL组)、射频照射组(RF组)、强脉冲

  12. Method and system for determining depth distribution of radiation-emitting material located in a source medium and radiation detector system for use therein

    Energy Technology Data Exchange (ETDEWEB)

    Benke, Roland R.; Kearfott, Kimberlee J.; McGregor, Douglas S.

    2004-04-27

    A radiation detector system includes detectors having different properties (sensitivity, energy resolution) which are combined so that excellent spectral information may be obtained along with good determinations of the radiation field as a function of position.

  13. Effect of sheath potential on electromagnetic radiation emitted from the rear surface of a metallic foil target

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In ultra-intense laser-matter interactions, intense electric fields formed at the rear surface of a foil target may have strong influences on the motion of energetic electrons, and thereby affect the electromagnetic emissions from the rear surface, usually ascribed to transition radiation. Due to the electric fields, transition radiation occurs twice and bremsstrahlung radiation also happens because the electrons will cross the rear surface twice and have large accelerations.In the optic region, transition radiation is dominant. The radiation spectrum depends on the electric field only when the electrons are monochromatic, and becomes independent of the electric field when the electrons have a broadband momentum distribution. Therefore, in an actual experiment, the electric field at the rear surface of a foil could not be studied just with the measurement of optic emissions. In the terahertz region, both bremsstrahlung and transition radiations should be taken into account, and the radiation power could be enhanced in comparison with that without the inclusion of bremsstrahlung radiation. The frequency at which the maximum terahertz radiation appears depends on the electric field.

  14. 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.

  15. Evidence for mobile phone radiation exposure effects on reproductive pattern of male rats: role of ROS.

    Science.gov (United States)

    Kesari, Kavindra Kumar; Behari, Jitendra

    2012-09-01

    The relationship between radiofrequency electromagnetic fields emitted from mobile phone and infertility is a matter of continuing debate. It is postulated that these radiations may affect the reproduction pattern spell by targeting biochemistry of sperm. In an attempt to expedite the issue, 70 days old Wistar rats (n = 6) were exposed to mobile phone radiofrequency (RF) radiation for 2 h per day for 45 days and data compared with sham exposed (n = 6) group. A significant decrease (P rats showed significant decreases in number and weight as compared with that of sham-exposed animals. A reduction in testosterone, an increase in caspase-3, and distortion in spermatozoa could be caused by overproduction of reactive oxygen species (ROS) in animals under mobile phone radiation exposure. Our findings on these biomarkers are clear indications of possible health implications of repeated exposure to mobile phone radiation.

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

    DEFF Research Database (Denmark)

    Xie, Tianwu; Zaidi, H.

    2016-01-01

    Purpose: 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. Methods: 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...

  17. Radiofrequency coblation tonsillectomy.

    Science.gov (United States)

    Grobler, Alethea; Carney, A Simon

    2006-06-01

    Radiofrequency coblation is a new technology that is finding favour as a method for performing tonsillectomy. Its benefits include reduced pain and postoperative morbidity but there is controversy regarding possible increased postoperative haemorrhage rates.

  18. 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

  19. Study of the Distribution of Radiative Defects and Reabsorption of the UV in ZnO Nanorods-Organic Hybrid White Light Emitting Diodes (LEDs).

    Science.gov (United States)

    Hussain, Ijaz; Bano, Nargis; Hussain, Sajjad; Soomro, Yousuf; Nur, Omer; Willander, Magnus

    2011-07-08

    In this study, the low temperature aqueous chemical growth (ACG) method was employed to synthesized ZnO nanorods to process-organic hybrid white light emitting diodes (LEDs) on glass substrate. Electroluminescence spectra of the hybrid white LEDs demonstrate the combination of emission bands arising from radiative recombination of the organic and ZnO nanorods (NRs). Depth resolved luminescence was used for probing the nature and spatial distribution of radiative defects, especially to study the re-absorption of ultraviolet (UV) in this hybrid white LEDs structure. At room temperature the cathodoluminescence (CL) spectra intensity of the deep band emission (DBE) is increased with the increase of the electron beam penetration depth due to the increase of defect concentration at the ZnO NRs/Polyfluorene (PFO) interface and probably due to internal absorption of the UV. A strong dependency between the intensity ratio of the UV to the DBE bands and the spatial distribution of the radiative defects in ZnO NRs has been found. The comparison of the CL spectra from the PFO and the ZnO NRs demonstrate that PFO has a very weak violet-blue emission band, which confirms that most of the white emission components originate from the ZnO NRs.

  20. Study of the Distribution of Radiative Defects and Reabsorption of the UV in ZnO Nanorods-Organic Hybrid White Light Emitting Diodes (LEDs

    Directory of Open Access Journals (Sweden)

    Yousuf Soomro

    2011-07-01

    Full Text Available In this study, the low temperature aqueous chemical growth (ACG method was employed to synthesized ZnO nanorods to process-organic hybrid white light emitting diodes (LEDs on glass substrate. Electroluminescence spectra of the hybrid white LEDs demonstrate the combination of emission bands arising from radiative recombination of the organic and ZnO nanorods (NRs. Depth resolved luminescence was used for probing the nature and spatial distribution of radiative defects, especially to study the re-absorption of ultraviolet (UV in this hybrid white LEDs structure. At room temperature the cathodoluminescence (CL spectra intensity of the deep band emission (DBE is increased with the increase of the electron beam penetration depth due to the increase of defect concentration at the ZnO NRs/Polyfluorene (PFO interface and probably due to internal absorption of the UV. A strong dependency between the intensity ratio of the UV to the DBE bands and the spatial distribution of the radiative defects in ZnO NRs has been found. The comparison of the CL spectra from the PFO and the ZnO NRs demonstrate that PFO has a very weak violet-blue emission band, which confirms that most of the white emission components originate from the ZnO NRs.

  1. Coherence properties and diagnostics of betatron radiation emitted by an externally-injected electron beam propagating in a plasma channel

    Energy Technology Data Exchange (ETDEWEB)

    Paroli, B., E-mail: bruno.paroli@unimi.it [Dipartimento di Fisica, Universitá degli Studi di Milano and INFN Sezione di Milano, via G. Celoria, 16, 20133 Milano (Italy); Chiadroni, E.; Ferrario, M. [INFN-LNF, via E. Fermi, 00044 Frascati (Italy); Mostacci, A. [“La Sapienza” University, SBAI Department, via A. Scarpa 14, 00161 Rome (Italy); INFN-LNF, via E. Fermi, 00044 Frascati (Italy); Petrillo, V.; Potenza, M.A.C.; Rossi, A.R.; Serafini, L. [Dipartimento di Fisica, Universitá degli Studi di Milano and INFN Sezione di Milano, via G. Celoria, 16, 20133 Milano (Italy)

    2015-07-15

    A 3-dimensional time-domain simulation of X-ray produced by a laser wakefield accelerated electron beam was performed in order to know its properties like intensity, spectrum, divergence and coherence. Particular attention was paid to the coherence around the acceleration axis. The broad spectrum of betatron radiation (1–10 keV) leads to a short coherence length. Nevertheless we observe that under particular detection condition the spatial coherence has a characteristic enlargement. We give a simplified interpretation of this effect in terms of phase shift of the electric field on a virtual detector. Moreover we describe a near field scattering technique to characterize the betatron radiation. This diagnostics will be used to map the transverse spatio-temporal coherence of X-ray radiation in the laser wakefield accelerator under development at Frascati National Laboratories (LNF)

  2. Coherence properties and diagnostics of betatron radiation emitted by an externally-injected electron beam propagating in a plasma channel

    Science.gov (United States)

    Paroli, B.; Chiadroni, E.; Ferrario, M.; Mostacci, A.; Petrillo, V.; Potenza, M. A. C.; Rossi, A. R.; Serafini, L.

    2015-07-01

    A 3-dimensional time-domain simulation of X-ray produced by a laser wakefield accelerated electron beam was performed in order to know its properties like intensity, spectrum, divergence and coherence. Particular attention was paid to the coherence around the acceleration axis. The broad spectrum of betatron radiation (1-10 keV) leads to a short coherence length. Nevertheless we observe that under particular detection condition the spatial coherence has a characteristic enlargement. We give a simplified interpretation of this effect in terms of phase shift of the electric field on a virtual detector. Moreover we describe a near field scattering technique to characterize the betatron radiation. This diagnostics will be used to map the transverse spatio-temporal coherence of X-ray radiation in the laser wakefield accelerator under development at Frascati National Laboratories (LNF).

  3. Automatic control by natural gamma radiation emitted by coal; Control Automatico mediante Radiometria Gamma Natural de la Cenizas de los Carbones

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Due to the characteristics of its coal and orebody, Monsacro shaft was chosen to host the test. The ash percentage of the different coal seams was carried out by two different methods: Traditional analysis in laboratory. Analysis by means of natural gamma radiation emitted by coal. The following conclusions were obtained after the test: Neither during the mounting nor during the test, a problem was encountered in the working of the radioactive methods. The absolute error between the two methods was minimum. The radioactive analysis is total (this means that the whole coal is analysed) and it is carried out in short period of time. The traditional one is just partial, and could take a few hours to accomplish it. The radioactive one is done in the wagon or in the belt conveyor directly, meanwhile the traditional one needs sample takers permanently. The investment cost of the radioactivity method is amortized within two years. (Author)

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

    NARCIS (Netherlands)

    Xie, Tianwu; Zaidi, Habib

    2016-01-01

    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

  5. Enhanced coherent emission of terahertz radiation by energy-phase correlation in a bunched electron beam.

    Science.gov (United States)

    Doria, A; Gallerano, G P; Giovenale, E; Messina, G; Spassovsky, I

    2004-12-31

    We report the first observation of enhanced coherent emission of terahertz radiation in a compact free electron laser. A radio-frequency (rf) modulated electron beam is passed through a magnetic undulator emitting coherent radiation at harmonics of the rf with a phase which depends on the electron drift velocity. A proper correlation between the energy and phase distributions of the electrons in the bunch has been exploited to lock in phase the radiated field, resulting in over 1 order of magnitude enhancement of the coherent emission.

  6. Radiative corrections to the semileptonic Dalitz plot with angular correlation between polarized decaying hyperons and emitted charged leptons

    CERN Document Server

    Martínez, A; Flores-Mendieta, R; García, A

    2001-01-01

    We obtain a model-independent expression for the Dalitz plot of semileptonic decays of polarized hyperons including radiative corrections to order alpha and neglecting terms of order (alpha q)/(pi M_1), where q is the four-momentum transfer and M_1 is the mass of the decaying hyperon. We specialize our results to exhibit the correlation between the charged-lepton momentum and the spin of the decaying hyperon. We present results for the three-body region of the Dalitz plot and for the complete Dalitz plot (which includes the four-body region). From these results we also obtain the corresponding radiative corrections to the integrated lepton spin-asymmetry coefficient. Our formulas are valid for charged as well as for neutral decaying hyperons and are appropriate for model-independent experimental analysis whether the real photon is discriminated or not.

  7. Gene expression does not change significantly in C3H 10T(1/2) cells after exposure to 847.74 CDMA or 835.62 FDMA radiofrequency radiation.

    Science.gov (United States)

    Whitehead, T D; Moros, E G; Brownstein, B H; Roti Roti, J L

    2006-06-01

    In vitro experiments with C3H 10T(1/2) mouse cells were performed to determine whether Frequency Division Multiple Access (FDMA) or Code Division Multiple Access (CDMA) modulated radiofrequency (RF) radiations induce changes in gene expression. After the cells were exposed to either modulation for 24 h at a specific absorption rate (SAR) of 5 W/ kg, RNA was extracted from both exposed and sham-exposed cells for gene expression analysis. As a positive control, cells were exposed to 0.68 Gy of X rays and gene expression was evaluated 4 h after exposure. Gene expression was evaluated using the Affymetrix U74Av2 GeneChip to detect changes in mRNA levels. Each exposure condition was repeated three times. The GeneChip data were analyzed using a two-tailed t test, and the expected number of false positives was estimated from t tests on 20 permutations of the six sham RF-field-exposed samples. For the X-ray-treated samples, there were more than 90 probe sets with expression changes greater than 1.3-fold beyond the number of expected false positives. Approximately one-third of these genes had previously been reported in the literature as being responsive to radiation. In contrast, for both CDMA and FDMA radiation, the number of probe sets with an expression change greater than 1.3-fold was less than or equal to the expected number of false positives. Thus the 24-h exposures to FDMA or CDMA RF radiation at 5 W/kg had no statistically significant effect on gene expression.

  8. 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

  9. Childhood leukemia in relation to radiofrequency electromagnetic fields emitted from television and radio broadcast transmitters. Results of a case-control study; Leukaemien im Kindesalter und elektromagnetische Felder in der Umgebung von Rundfunkstationen. Ergebnisse einer Fall-Kontroll-Studie

    Energy Technology Data Exchange (ETDEWEB)

    Schmiedel, Sven [Danish Cancer Society, Copenhagen (Denmark). Inst. of Cancer Epidemiology; Universitaetsmedizin Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Merzenich, Hiltrud; Bennack, Sabrina; Blettner, Maria [Universitaetsmedizin Mainz Univ. (DE). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Brueggemeyer, Hauke [Niedersaechsischer Landesbetrieb fuer Wasserwirtschaft, Kuesten- und Naturschutz, Hildesheim (Germany). AB35 - Strahlenschutz in Niedersachsen; Philipp, Johannes [Suedwestrundfunk, Stuttgart (Germany). Abt. Frequenz- und Versorgungsplanung; Schuetz, Joachim [Danish Cancer Society, Copenhagen (Denmark). Inst. of Cancer Epidemiology

    2009-07-01

    The causes of childhood leukemia are poorly understood. Radio frequency electromagnetic fields (RF-EMF) emitted from broadcast stations are possible risk factors. A case-control study was conducted in West Germany on RF-EMF and childhood leukemia. The study region consisted of municipalities near 24 radio and television transmitters. Cases (aged 0-14 years, diagnosis 1984-2003) were registered at the German childhood cancer registry. Three age-, gender- and transmitter areamatched controls per case were drawn randomly from population registries. The analysis included 1,959 cases and 5,848 controls. The RF-EMF exposure was calculated with a field strength prediction program. In the statistical analysis conditional logistic regression was used. Considering total RF-EMF, the odds ratio for leukemia was 0.86 (95% confidence interval 0.67-1.11) comparing upper ({>=}95%) and lower (<90%) quantile for the RF-EMF distribution. No association between RF-EMF exposure and leukemia was observed for the time periods before and after the introduction of mobile telecommunication. There was no increased risk among children living in the 2 km vicinity of the transmitters. The study provides no evidence for an association between RF-EMF and childhood leukemia. (orig.)

  10. 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

  11. Occupational exposure of welders to ultraviolet and "blue light" radiation emitted during TIG and MMA welding based on field measuremants

    Directory of Open Access Journals (Sweden)

    Agnieszka Wolska

    2013-02-01

    Full Text Available Background: The aim of the study was to present the results of welders' occupational exposure to "blue light" and UV radiation carried out at industrial workstations during TIG and MMA welding. Materials and methods: Measurements were performed at 13 workstations (TIG welding: 6; MMA welding: 7, at which different welding parameters and materials were used. The radiation level was measured using a wide-range radiometer and a set of detectors, whose spectral responses were adequately fit to particular hazard under study. The measurement points corresponded with the location of eye and hand. Results: The highest values of eye irradiance were found for aluminum TIG welding. Effective irradiance of actinic UV was within the range Es = 7.79-37.6 W/m2; UVA total irradiance, EUVA = 18-53.1 W/m2 and effective blue-light irradiance EB = 35-67 W/m2. The maximum allowance time ranged from 1.7 to 75 s, which means that in some cases even unintentional very short eye exposure can exceed MPE. Conclusions: The influence of welded material and the type of electrode coating on the measured radiation level were evidenced. The exceeded value of MPE for photochemical hazard arising for the eyes and skin was found at all measured workstations. Welders should use appropriately the eye and face protective equipment and avoid direct staring at welding arc when starting an arcwelding operation. Besides, the lack of head and neck skin protection can induce acute and chronic harmful health effects. Therefore, an appropriate wear of personal protective equipment is essential for welders' health. Med Pr 2013;64(1:69–82

  12. 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.

  13. 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).

  14. Lepton-pair Cerenkov radiation emitted by tachyonic neutrinos: Lorentz-covariant approach and IceCube data

    CERN Document Server

    Jentschura, Ulrich D

    2016-01-01

    Current experiments do not exclude the possibility that one or more neutrinos are very slightly superluminal or that they have a very small tachyonic mass. Important bounds on the size of a hypothetical tachyonic neutrino mass term are set by lepton pair Cerenkov radiation (LPCR), i.e., by the decay channel nu -> e^+ e^- nu which proceeds via a virtual Z0 boson. Here, we use a Lorentz-invariant dispersion relation which leads to very tight constraints on the tachyonic mass of neutrinos; we also calculate decay and energy loss rates. A possible cutoff seen in the IceCube neutrino spectrum for E_nu > 2 PeV, due to the potential onset of LPCR, is discussed.

  15. 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.

  16. 8-oxoG DNA Glycosylase-1 Inhibition Sensitizes Neuro-2a Cells to Oxidative DNA Base Damage Induced by 900 MHz Radiofrequency Electromagnetic Radiation

    Directory of Open Access Journals (Sweden)

    Xiaoya Wang

    2015-09-01

    Full Text Available Background/Aims: The purpose of this study was to explore the in vitro putative genotoxicity during exposure of Neuro-2a cells to radiofrequency electromagnetic fields (RF-EMFs with or without silencing of 8-oxoG DNA glycosylase-1 (OGG1. Methods: Neuro-2a cells treated with or without OGG1 siRNA were exposed to 900 MHz Global System for Mobile Communication (GSM Talk signals continuously at a specific absorption rate (SAR of 0, 0.5, 1 or 2 W/kg for 24 h. DNA strand breakage and DNA base damage were measured by the alkaline comet assay and a modified comet assay using formamidopyrimidine DNA glycosylase (FPG, respectively. Reactive oxygen species (ROS levels and cell viability were monitored using the non-fluorescent probe 2, 7-dichlorofluorescein diacetate (DCFH-DA and CCK-8 assay. Results: Exposure to 900 MHz RF-EMFs with insufficient energy could induce oxidative DNA base damage in Neuro-2a cells. These increases were concomitant with similar increases in the generation of reactive oxygen species (ROS. Without OGG1 siRNA, 2 W/kg RF-EMFs induced oxidative DNA base damage in Neuro-2a cells. Interestingly, with OGG1 siRNA, RF-EMFs could cause DNA base damage in Neuro-2a cells as low as 1 W/kg. However, neither DNA strand breakage nor altered cell viability was observed. Conclusion: Even if further studies remain conducted we support the hypothesis that OGG1 is involved in the process of DNA base repair and may play a pivotal role in protecting DNA bases from RF-EMF induced oxidative damage.

  17. Free radical release and HSP70 expression in two human immune-relevant cell lines after exposure to 1800 MHz radiofrequency radiation.

    Science.gov (United States)

    Lantow, M; Schuderer, J; Hartwig, C; Simkó, M

    2006-01-01

    The goal of this study was to investigate whether radiofrequency (RF) electromagnetic-field (EMF) exposure at 1800 MHz causes production of free radicals and/or expression of heat-shock proteins (HSP70) in human immune-relevant cell systems. Human Mono Mac 6 and K562 cells were used to examine free radical release after exposure to incubator control, sham, RF EMFs, PMA, LPS, heat (40 degrees C) or co-exposure conditions. Several signals were used: continuous-wave, several typical modulations of the Global System for Mobile Communications (GSM): GSM-non DTX (speaking only), GSM-DTX (hearing only), GSM-Talk (34% speaking and 66% hearing) at specific absorption rates (SARs) of 0.5, 1.0, 1.5 and 2.0 W/kg. Heat and PMA treatment induced a significant increase in superoxide radical anions and in ROS production in the Mono Mac 6 cells when compared to sham and/or incubator conditions. No significant differences in free radical production were detected after RF EMF exposure or in the respective controls, and no additional effects on superoxide radical anion production were detected after co-exposure to RF EMFs+PMA or RF EMFs+LPS. The GSM-DTX signal at 2 W/kg produced a significant difference in free radical production when the data were compared to sham because of the decreasing sham value. This difference disappeared when data were compared to the incubator controls. To determine the involvement of heat-shock proteins as a possible inhibitor of free radical production, we investigated the HSP70 expression level after different RF EMF exposures; no significant effects were detected.

  18. Establishment of the central radiation dose registration system for decontamination work involving radioactive fallout emitted by the Fukushima Daiichi APP accident.

    Science.gov (United States)

    Yasui, Shojiro

    2016-10-01

    With respect to radiation protection for decontamination efforts involving radioactive fallout emitted by the accident at the Fukushima Daiichi Atomic Power Plant, new regulations were established and obligated employers to monitor, record, and store of workers' dose records, and to check their past dose records at the time of employment. However, cumulative doses may not be properly maintained if a worker declares incorrect values for past doses. In response, with facilitation from the Ministry of Health, Labour and Welfare, primary contractors of decontamination works decided to establish a central dose registration system. There are four major issues in the design of the system to be resolved, included the following: primary contractors (a) do not have a legal responsibility to perform dose control for subcontractors, (b) do not have the right to control decontamination sites, (c) often organize joint ventures, and (d) correspond to a wide range of ambient dose rates. To resolve the issues, requirements of the system included the following: (a) centralize the operation of radiation passbooks, which records past doses and the results of medical examinations to each worker; (b) develop a database system that could register all dose data and accept inquiry from primary contractors; (c) establish a permanent data storage system for transferred records; and (d) provide graded type of services that are appropriate to the risk of radiation exposure. The system started its operation in December 2013 and provided dose distributions in April and July 2015. The average yearly dose in 2014 was 0.7 mSv, which increased by 0.2 mSv from 0.5 mSv in 2012 and 2013. However, no cumulative dose from 2012-2014 exceeded 20 mSv, which was far below than the dose limits (100 mSv/5 years and 50 mSv/year). Although current dose distributions of decontamination workers were within appropriate levels, careful monitoring of dose distribution is necessary for preserving the proper

  19. The sensitivity of tropical convective precipitation to the direct radiative forcings of black carbon aerosols emitted from major regions

    Directory of Open Access Journals (Sweden)

    C. Wang

    2009-10-01

    Full Text Available Previous works have suggested that the direct radiative forcing (DRF of black carbon (BC aerosols are able to force a significant change in tropical convective precipitation ranging from the Pacific and Indian Ocean to the Atlantic Ocean. In this in-depth analysis, the sensitivity of this modeled effect of BC on tropical convective precipitation to the emissions of BC from 5 major regions of the world has been examined. In a zonal mean base, the effect of BC on tropical convective precipitation is a result of a displacement of ITCZ toward the forcing (warming hemisphere. However, a substantial difference exists in this effect associated with BC over different continents. The BC effect on convective precipitation over the tropical Pacific Ocean is found to be most sensitive to the emissions from Central and North America due to a persistent presence of BC aerosols from these two regions in the lowermost troposphere over the Eastern Pacific. The BC effect over the tropical Indian and Atlantic Ocean is most sensitive to the emissions from South as well as East Asia and Africa, respectively. Interestingly, the summation of these individual effects associated with emissions from various regions mostly exceeds their actual combined effect as shown in the model run driven by the global BC emissions, so that they must offset each other in certain locations and a nonlinearity of this type of effect is thus defined. It is known that anthropogenic aerosols contain many scattering-dominant constituents that might exert an effect opposite to that of absorbing BC. The combined aerosol forcing is thus likely differing from the BC-only one. Nevertheless, this study along with others of its kind that isolates the DRF of BC from other forcings provides an insight of the potentially important climate response to anthropogenic forcings particularly related to the unique particulate solar absorption.

  20. The effect of 835.62 MHz FDMA or 847.74 MHz CDMA modulated radiofrequency radiation on the induction of micronuclei in C3H 10T(1/2) cells.

    Science.gov (United States)

    Bisht, Kheem S; Moros, Eduardo G; Straube, William L; Baty, Jack D; Roti Roti, Joseph L

    2002-05-01

    To determine if radiofrequency (RF) radiation induces the formation of micronuclei, C3H 10T(1/2) cells were exposed to 835.62 MHz frequency division multiple access (FDMA) or 847.74 MHz code division multiple access (CDMA) modulated RF radiation. After the exposure to RF radiation, the micronucleus assay was performed by the cytokinesis block method using cytochalasin B treatment. The micronuclei appearing after mitosis were scored in binucleated cells using acridine orange staining. The frequency of micronuclei was scored both as the percentage of binucleated cells with micronuclei and as the number of micronuclei per 100 binucleated cells. Treatment of cells with cytochalasin B at a concentration of 2 microg/ml for 22 h was found to yield the maximum number of binucleated cells in C3H 10T(1/2) cells. The method used for the micronucleus assay in the present study detected a highly significant dose response for both indices of micronucleus production in the dose range of 0.1-1.2 Gy and it was sensitive enough to detect a significant (P > 0.05) increase in micronuclei after doses of 0.3 Gy in exponentially growing cells and after 0.9 Gy in plateau-phase cells. Exponentially growing cells or plateau-phase cells were exposed to CDMA (3.2 or 4.8 W/kg) or FDMA (3.2 or 5.1 W/kg) RF radiation for 3, 8, 16 or 24 h. In three repeat experiments, no exposure condition was found by analysis of variance to result in a significant increase relative to sham-exposed cells either in the percentage of binucleated cells with micronuclei or in the number of micronuclei per 100 binucleated cells. In this study, data from cells exposed to different RF signals at two SARs were compared to a common sham-exposed sample. We used the Dunnett's test, which is specifically designed for this purpose, and found no significant exposure-related differences for either plateau-phase cells or exponentially growing cells. Thus the results of this study are not consistent with the possibility that

  1. Effect of limb darkening on the radiation flux emitted from the inner region towards the outer region in accretion discs around black holes

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Ci-sheng

    1984-06-01

    Because of the thermal instability of bremsstrahlung, the optically thin outer region in accretion discs around black holes would collapse to form the optically thick inner region. The former would be geometrically much thicker than the latter. Taking limb darkening into account, accurate calculations have been carried out for the ratio L*/L/sub 0/, where L/sub 0/ is the total radiation flux emitted in the inner region of the discs and L* is a part of L/sub 0/ which strikes the outer region. A limb-darkening law I(r,theta) = I(r,0)(1-u+u cos theta) is used, u being the limb-darkening coefficient. L*/L/sub 0/ can be expressed as L*/L/sub 0/ = ..beta..h/sup 2//sub asterisk/, where ..beta.. is determined by formulae (10)--(12). r/sub 0/, r/sub 1/ and h(r/sub 1/), which appear in the definition of the dimensionless parameters x,x/sub 1/ and h/sub asterisk/, are the innermost radius of the inner region, the radius of the boundary between the two regions, and the half thickness of the outer region at radius r/sub 1/, respectively.

  2. Blue light hazard optimization for white light-emitting diode sources with high luminous efficacy of radiation and high color rendering index

    Science.gov (United States)

    Zhang, Jingjing; Guo, Weihong; Xie, Bin; Yu, Xingjian; Luo, Xiaobing; Zhang, Tao; Yu, Zhihua; Wang, Hong; Jin, Xing

    2017-09-01

    Blue light hazard of white light-emitting diodes (LED) is a hidden risk for human's photobiological safety. Recent spectral optimization methods focus on maximizing luminous efficacy and improving color performances of LEDs, but few of them take blue hazard into account. Therefore, for healthy lighting, it's urgent to propose a spectral optimization method for white LED source to exhibit low blue light hazard, high luminous efficacy of radiation (LER) and high color performances. In this study, a genetic algorithm with penalty functions was proposed for realizing white spectra with low blue hazard, maximal LER and high color rendering index (CRI) values. By simulations, white spectra from LEDs with low blue hazard, high LER (≥297 lm/W) and high CRI (≥90) were achieved at different correlated color temperatures (CCTs) from 2013 K to 7845 K. Thus, the spectral optimization method can be used for guiding the fabrication of LED sources in line with photobiological safety. It is also found that the maximum permissible exposure duration of the optimized spectra increases by 14.9% than that of bichromatic phosphor-converted LEDs with equal CCT.

  3. Cellular and molecular level responses after radiofrequency radiation exposure, alone or in combination with x-rays or chemicals. Final report, 1 April 1991-30 September 1994

    Energy Technology Data Exchange (ETDEWEB)

    Meltz, M.L.; Natarajan, M.; Prasad, A.V.

    1995-02-21

    This project was initiated to explore the potential bioeffects of microwave radiation, alone or in combination with ionizing radiation and chemicals. Over the time period of the project, an automated thermal control system, to be used for maintaining the temperature in tissue culture medium during microwave exposures, was designed, constructed, and software was created. While this was underway during the project period, numerous positive control biological experiments were performed on two different cell types, the Epstein Barr Virus transformed 244B human lymphoblastoid cell, and the freshly isolated peripheral human lymphocyte. The 244B cells were used to address the question of whether a physical agent, ionizing radiation, at low doses where cells would predominantly remain viable, would induce the DNA binding protein NF-kB, and/or four immediate early genes (IEG) (protooncogenes).

  4. Definition of Procedures for Chronic Exposure of Cancer-Prone Mice to Low-Level 2,450-MHz Radiofrequency Radiation

    Science.gov (United States)

    1991-09-01

    et al. ’s work yielded two positive correlations between microwave exposure and cancer: (1) The incidence of benign pheochromocytomas of the adrenal...Radiat Environ Biophys 28:67-77 (1989a). Frei, M.R., Jauchem, J.R., Padilla, J.M., and Merritt, J.H. Thermal and physiological responses of rats exposed

  5. Comparison of the efficiency of titanium(IV) and iron(III) oxide nanoparticles as mediators in suppression of bacterial growth by radiation of a blue (405 nm) light-emitting diode

    Science.gov (United States)

    Petrov, P. O.; Tuchina, E. S.; Kulikova, M. V.; Kochubei, V. I.; Tuchin, V. V.

    2013-08-01

    The effect of blue (405 nm) radiation of a light-emitting diode in combination with titanium(IV) and iron(III) oxide nanoparticles on S. aureus 209 P, S. simulans, and D. hominis bacteria is studied. It is shown that, upon irradiation of bacteria by blue (405 nm) light, Fe2O3 nanoparticles have a stronger (by 5-30%) antibacterial effect than TiO2 nanoparticles.

  6. Robust Satellite Techniques for monitoring earth emitted radiation in the Japanese seismic area by using MTSAT observations in the TIR spectral range

    Science.gov (United States)

    Genzano, Nicola; Filizzola, Carolina; Hattori, Katsumi; Lisi, Mariano; Paciello, Rossana; Pergola, Nicola; Tramutoli, Valerio

    2016-04-01

    Since eighties, the fluctuations of Earth's thermally emitted radiation, measured by satellite sensors operating in the thermal infrared (TIR) spectral range, have been associated with the complex process of preparation for major earthquakes. But, like other claimed earthquake precursors (seismological, physical, chemical, biological, etc.) they have been for long-time considered with some caution by scientific community. The lack of a rigorous definition of anomalous TIR signal fluctuations and the scarce attention paid to the possibility that other causes (e.g. meteorological) different from seismic activity could be responsible for the observed TIR variations were the main causes of such skepticism. Compared with previously proposed approaches the general change detection approach, named Robust Satellite Techniques (RST), showed good ability to discriminate anomalous TIR signals possibly associated to seismic activity, from the normal variability of TIR signal due to other causes. Thanks to its full exportability on different satellite packages, since 2001 RST has been implemented on TIR images acquired by polar (e.g. NOAA-AVHRR, EOS -MODIS) and geostationary (e.g. MSG-SEVIRI, NOAA-GOES/W, GMS-5/VISSR) satellite sensors, in order to verify the presence (or absence) of TIR anomalies in presence (absence) of earthquakes (with M>4) in different seismogenic areas around the world (e.g. Italy, Greece, Turkey, India, Taiwan, etc.). In this paper, the RST data analysis approach has been implemented on TIR satellite records collected over Japan by the geostationary satellite sensor MTSAT (Multifunctional Transport SATellites) and RETIRA (Robust Estimator of TIR Anomalies) index was used to identify Significant Sequences of TIR Anomalies (SSTAs) in a possible space-time relations with seismic events. Achieved results will be discussed in the perspective of a multi-parametric approach for a time-Dependent Assessment of Seismic Hazard (t-DASH).

  7. Microwave discharge electrodeless lamps (MDEL). III. A novel tungsten-triggered MDEL device emitting VUV and UVC radiation for use in wastewater treatment.

    Science.gov (United States)

    Horikoshi, Satoshi; Miura, Takashi; Kajitani, Masatsugu; Serpone, Nick

    2008-03-01

    Exposure to low doses of the xenoestrogen bisphenol A (BPA) and to the hormonal 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide, an environmental endocrine disruptor, can have serious health consequences such as the induction of mammary gland ductal hyperplasias and carcinoma (LaChapelle et al., Reprod. Toxicol., 2007, 23, 20; Murray et al., Reprod. Toxicol., 2007, 23, 383). To the extent that these toxins are present in wastewaters (Donald et al., Sci. Total Environ. 1999, 231, 173; Brotons et al., Environ. Health Perspect. 1994, 103, 608; Olea et al., Environ. Health Perspect. 1996, 104, 298; Biles et al., J. Agric. Food Chem. 1997, 45, 3541; Markey et al., J. Steroid Biochem. Mol. Biol., 2003, 83, 235), we examined their oxidative destruction in aqueous media by a novel light source. A tungsten-triggered microwave discharge electrodeless lamp (W-MDEL) was fabricated for possible use in wastewater treatment using vacuum UV-transparent quartz in which a tungsten trigger, also embedded in quartz, was attached to the MDEL to aid in the self-ignition of the lamp on irradiation at low microwave power levels. The quantity of mercury gas in the W-MDEL was optimized by monitoring the continuous radiation and peak intensities of the emitted light in the vacuum UV (VUV) and UVC regions. The usefulness of the W-MDEL device was assessed through the degradation of 2,4-D and BPA in air-equilibrated aqueous media and in oxygen-saturated aqueous media. Enhanced degradation of these two xenoestrogenic toxins was achieved by increasing the number of W-MDEL devices while keeping constant the microwave radiation feeding each W-MDEL lamp. This novel lamp provides an additional light source in the photooxidation of environmental contaminants without the need for a metal-oxide photocatalyst. Under our conditions, process dynamics using the W-MDEL light source are greater than with the more conventional photochemical methods that employ low-pressure Hg arc electrode lamps in synthetic

  8. Spectral investigation of hot-spot and cavity resonance effects on the terahertz radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ single crystal mesa structures

    Science.gov (United States)

    Kadowaki, Kazuo; Watanabe, Chiharu; Minami, Hidetoshi; Yamamoto, Takashi; Kashiwagi, Takanari; Klemm, Richard

    2014-03-01

    Terahertz (THz) electromagnetic radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ mesa structures in the case of single mesa and series-connected mesas is investigated by the FTIR spectroscopic technique while observing its temperature distribution simultaneously by a SiC photoluminescence technique. Changing the bias level, sudden jumps of the hot-spot position were clearly observed. Although the radiation intensity changes drastically associated with the jump of the hot spot position, the frequency is unaffected as long as the voltage per junction is kept constant. Since the frequency of the intense radiation satisfies the cavity resonance condition, we confirmed that the cavity resonance is of primarily importance for the synchronization of whole intrinsic Josephson junctions in the mesa for high power radiation. This work was supported in part by the Grant-in-Aid for challenging Exploratory Research, the Ministry of Education, Culture, Sports, Science & Technology (MEXT).

  9. 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.

  10. Effects of radiofrequency electromagnetic waves (RF-EMW) from cellular phones on human ejaculated semen: an in vitro pilot study.

    Science.gov (United States)

    Agarwal, Ashok; Desai, Nisarg R; Makker, Kartikeya; Varghese, Alex; Mouradi, Rand; Sabanegh, Edmund; Sharma, Rakesh

    2009-10-01

    To evaluate effects of cellular phone radiofrequency electromagnetic waves (RF-EMW) during talk mode on unprocessed (neat) ejaculated human semen. Prospective pilot study. Center for reproductive medicine laboratory in tertiary hospital setting. Neat semen samples from normal healthy donors (n = 23) and infertile patients (n = 9). After liquefaction, neat semen samples were divided into two aliquots. One aliquot (experimental) from each patient was exposed to cellular phone radiation (in talk mode) for 1 h, and the second aliquot (unexposed) served as the control sample under identical conditions. Evaluation of sperm parameters (motility, viability), reactive oxygen species (ROS), total antioxidant capacity (TAC) of semen, ROS-TAC score, and sperm DNA damage. Samples exposed to RF-EMW showed a significant decrease in sperm motility and viability, increase in ROS level, and decrease in ROS-TAC score. Levels of TAC and DNA damage showed no significant differences from the unexposed group. Radiofrequency electromagnetic waves emitted from cell phones may lead to oxidative stress in human semen. We speculate that keeping the cell phone in a trouser pocket in talk mode may negatively affect spermatozoa and impair male fertility.

  11. Progress Towards High-Sensitivity Arrays of Detectors of Sub-mm Radiation using Superconducting Tunnel Junctions with Radio-Frequency Single-Electron Transistors

    Science.gov (United States)

    Stevenson, T. R.; Hsieh, W.-T.; Li, M. J.; Stahle, C. M.; Wollack, E. J.; Schoelkopf, R. J.; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The science drivers for the SPIRIT/SPECS missions demand sensitive, fast, compact, low-power, large-format detector arrays for high resolution imaging and spectroscopy in the far infrared and submillimeter. Detector arrays with 10,000 pixels and sensitivity less than 10(exp 20)-20 W/Hz(exp 20)0.5 are needed. Antenna-coupled superconducting tunnel junction detectors with integrated rf single-electron transistor readout amplifiers have the potential for achieving this high level of sensitivity, and can take advantage of an rf multiplexing technique when forming arrays. The device consists of an antenna structure to couple radiation into a small superconducting volume and cause quasiparticle excitations, and a single-electron transistor to measure currents through tunnel junction contacts to the absorber volume. We will describe optimization of device parameters, and recent results on fabrication techniques for producing devices with high yield for detector arrays. We will also present modeling of expected saturation power levels, antenna coupling, and rf multiplexing schemes.

  12. Radio-frequency sheath voltages and slow wave electric field spatial structure

    Energy Technology Data Exchange (ETDEWEB)

    Colas, Laurent, E-mail: laurent.colas@cea.fr; Lu, Ling-Feng [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Křivská, Alena [LPP-ERM-KMS, TEC partner, Brussels (Belgium); Jacquot, Jonathan [Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2015-12-10

    We investigate theoretically how sheath radio-frequency (RF) oscillations relate to the spatial structure of the RF parallel electric field emitted by Ion Cyclotron (IC) wave launchers, using a simple model of Slow Wave (SW) evanescence coupled with Direct Current (DC) plasma biasing via sheath boundary conditions in a plasma-filled 2-dimensional (parallel, radial) rectangle. Within a “wide sheaths” asymptotic regime, valid for large-amplitude near RF fields, our model becomes partly linear: the sheath oscillating voltage at open field line boundaries is a linear combination of elementary contributions by every source point of the radiated RF field map. These individual contributions are all the more intense as the SW emission point is toroidally nearer to the sheath walls. A limit formula is given for a source infinitely close to the sheaths. The decay of sheath RF voltages with the sheath/source parallel distance is quantified as a function of two characteristic SW evanescence lengths. Decay lengths are smaller than antenna parallel extensions. The sheath RF voltages at an IC antenna side limiter are therefore mainly sensitive to SW emission near this limiter, as recent observations suggest. Toroidal proximity effects could also explain why sheath oscillations persist with antisymmetric strap toroidal phasing, despite the parallel anti-symmetry of the radiated field map. They could also justify current attempts at reducing the RF fields induced near antenna boxes to attenuate sheath oscillations in their vicinity.

  13. Radiofrequency Ablation in Barrett's Esophagus

    Directory of Open Access Journals (Sweden)

    Vani J.A. Konda

    2014-01-01

    Full Text Available Radiofrequency ablation (RFA is an endoscopic modality used in the treatment of Barrett's esophagus. RFA may be performed using a balloon-based catheter or using one of the probe catheters that attaches to the distal end of the endoscope. Here we demonstrate step-by-step instruction in using radiofrequency ablation in the treatment of Barrett's esophagus and highlight key concepts in the technique.

  14. Radiofrequency Radiation Effects on Excitable Tissues

    Science.gov (United States)

    1983-11-01

    B. G. Katzung , and J. S. Schroeder. Do calcium-dependent ionic currents mediate ischemic ventricular fibrillation? Am J Cardiol 49:606-612 (1982). 20...Trans Microwave Theory Tech MTT-19:168-173 (1971). 29. Karagueuzian, H. S., and B. G. Katzung . Voltage clamp studies of transient inward current and

  15. Radiofrequency Radiation Dosimetry Handbook. 4th Edition

    Science.gov (United States)

    1986-10-01

    healthy humans of specific age and somatotype .......... ................ 10.17 10.3. Variation of metabolic rate with activity for a normal 20-24...metabulic rate," varies greatly with body size and proportion ( somatotype ), several measures of this variable are in wide use. Figure 10.4 is a log-log...is often called "metabolic rate" (MR). Table 10.2 lists resting metabolic rates for normal healthy humans of varying age and somatotype . The specific

  16. Radiofrequency fields and teratogenesis.

    Science.gov (United States)

    Heynick, Louis N; Merritt, James H

    2003-01-01

    Experimental studies that sought teratologic effects or developmental abnormalities from exposure to radiofrequency electromagnetic fields (RFEMF) in the range 3 kHz-300 GHz are critically reviewed for their possible consequences on human health. Those studies were conducted on beetles, birds, rodents, and nonhuman primates. Collectively, those experimental studies indicate that teratologic effects can occur only from exposure levels that cause biologically detrimental increases in body temperature. No reliable experimental evidence was found for nonthermal teratologic effects; rodents, mouse fetuses, and perinatal mice are more susceptible to such effects than rats. The primary confirmed effect in rats at high RFEMF levels was initial weight deficits in fetuses and neonates that decreased with infant growth. More generally from findings with pregnant mammals, exposures at RFEMF levels far higher than those permitted under the IEEE human exposure guidelines are necessary to reach or exceed cited experimental thresholds for maternal temperature increases. Some results indicated that the levels necessary to cause such effects in pregnant mammals could exceed those lethal to the dams. In a behavioral study of squirrel monkeys, no effects were observed on usual dam-offspring interactions or EEGs, but unexpected deaths of a number of offspring had occurred. However, this finding was not confirmed in a study solely on infant death using a larger number of subjects for greater statistical validity. Also reviewed were epidemiologic studies of various human populations considered to have been chronically exposed to environmental levels of RFEMF. Early studies on the incidence of congenital anomalies yielded no credible evidence that chronic exposure of pregnant women or of fathers exposed to RFEMF from nearby sources at levels below those guidelines would cause any anomalies in their offspring. The findings of studies on pregnancy outcomes of female physiotherapists

  17. 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

  18. Creating Feshbach resonances for ultracold molecule formation with radiofrequency fields

    CERN Document Server

    Owens, Daniel J; Hutson, Jeremy M

    2016-01-01

    We show that radiofrequency (RF) radiation may be used to create Feshbach resonances in ultracold gases of alkali-metal atoms at desired magnetic fields that are convenient for atomic cooling and degeneracy. For the case of $^{39}$K+$^{133}$Cs, where there are no RF-free resonances in regions where Cs may be cooled to degeneracy, we show that a resonance may be created near 21~G with 67~MHz RF radiation. This resonance is almost lossless with circularly polarized RF, and the molecules created are long-lived even with plane-polarized RF.

  19. Radiofrequency ablation of atrial fibrillation

    NARCIS (Netherlands)

    Wiesfeld, ACP; Tan, ES; Van Veldhuisen, DJ; Crijns, HJGM; Van Gelder, IC

    2004-01-01

    Twenty-five patients (16 males, mean age 46 years.) underwent radiofrequency ablation because of either paroxysmal (13 patients) or persistent atrial fibrillation (12 patients). Ablation aimed at earliest activation of spontaneous and catheter-induced repetitive ectopy in left and right atria and ap

  20. LEP radio-frequency cavity

    CERN Multimedia

    1991-01-01

    One of the copper radio-frequency accelerating cavities installed for the first phase of LEP (1989-1995). Bunches of electrons and positrons circulated in LEP in opposite directions and were accelerated in eight different sets of 16 cavities (situated on either side of the four experiments), gaining 400 million volts of accelerating power per turn.

  1. Spectral characteristics of radiation emitted by a YAG:Nd/sup 3 +/ laser with a saturable absorber in the form of an LiF crystal containing F/sub 2//sup -/ centers

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, Y.L.; Kirpichnikov, A.V.; Lisitsyn, V.N.; Marennikov, S.I.

    1981-05-01

    An experimental investigation was made of the spectral characteristics of radiation emitted by a YAG:Nd/sup 3 +/ laser in which an LiF crystal containing F/sub 2//sup -/ centers was used as a passive switch. Single-frequency emission and mode locking operation regimes were investigated. In the single-frequency regime the minimum width of the emission line was 5 x 10/sup -3/ cm/sup -1/ for a single pulse. The frequency selection mechanism involved spatially inhomogeneous saturation of the absorption. Mode locking took place in a ring resonator when a saturable crystal filter with an initial transmission 0.7 was used. The use of a switch containing color centers made it possible to generate picosecond pulses simply and reliably.

  2. 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...

  3. Addressed qubit manipulation in radio-frequency dressed lattices

    Science.gov (United States)

    Sinuco-León, G. A.; Garraway, B. M.

    2016-03-01

    Precise control over qubits encoded as internal states of ultracold atoms in arrays of potential wells is a key element for atomtronics applications in quantum information, quantum simulation and atomic microscopy. Here we theoretically study atoms trapped in an array of radio-frequency dressed potential wells and propose a scheme for engineering fast and high-fidelity single-qubit gates with low error due to cross-talk. In this proposal, atom trapping and qubit manipulation relies exclusively on long-wave radiation making it suitable for atom-chip technology. We demonstrate that selective qubit addressing with resonant microwaves can be programmed by controlling static and radio-frequency currents in microfabricated conductors. These results should enable studies of neutral-atom quantum computing architectures, powered by low-frequency electromagnetic fields with the benefit of simple schemes for controlling individual qubits in large ensembles.

  4. Induction of Autophagy in the Striatum and Hypothalamus of Mice after 835 MHz Radiofrequency Exposure

    OpenAIRE

    Kim, Ju Hwan; Huh, Yang Hoon; Kim, Hak Rim

    2016-01-01

    The extensive use of wireless mobile phones and associated communication devices has led to increasing public concern about potential biological health-related effects of the exposure to electromagnetic fields (EMFs). EMFs emitted by a mobile phone have been suggested to influence neuronal functions in the brain and affect behavior. However, the affects and phenotype of EMFs exposure are unclear. We applied radiofrequency (RF) of 835 MHz at a specific absorption rate (SAR) of 4.0 W/kg for 5 h...

  5. Increased Radioresistance to Lethal Doses of Gamma Rays in Mice and Rats after Exposure to Microwave Radiation Emitted by a GSM Mobile Phone Simulator.

    Science.gov (United States)

    Mortazavi, Smj; Mosleh-Shirazi, Ma; Tavassoli, Ar; Taheri, M; Mehdizadeh, Ar; Namazi, Sas; Jamali, A; Ghalandari, R; Bonyadi, S; Haghani, M; Shafie, M

    2013-01-01

    The aim of this study was to investigate the effect of pre-irradiation with microwaves on the induction of radioadaptive response. In the 1(st) phase of the study, 110 male mice were divided into 8 groups. The animals in these groups were exposed/sham-exposed to microwave, low dose rate gamma or both for 5 days. On day six, the animals were exposed to a lethal dose (LD). In the 2(nd) phase, 30 male rats were divided into 2 groups of 15 animals. The 1(st) group received microwave exposure. The 2(nd) group (controls) received the same LD but there was no treatment before the LD. On day 5, all animals were whole-body irradiated with the LD. Statistically significant differences between the survival rate of the mice only exposed to lethal dose of gamma radiation before irradiation with a lethal dose of gamma radiation with those of the animals pre-exposed to either microwave (p=0.02), low dose rate gamma (p=0.001) or both of these physical adapting doses (p=0.003) were observed. Likewise, a statistically significant difference between survival rates of the rats in control and test groups was observed. Altogether, these experiments showed that exposure to microwave radiation may induce a significant survival adaptive response.

  6. Radiofrequency Ablation of Lung Cancer at Okayama University Hospital: A Review of 10 Years of Experience

    Directory of Open Access Journals (Sweden)

    Hiraki,Takao

    2011-10-01

    Full Text Available The application of radiofrequency ablation for the treatment of lung cancer by our group at Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences began in June 2001, and in the present report, we review our 10-year experience with this treatment modality at Okayama University Hospital. The local efficacy of radiofrequency ablation for the treatment of lung cancer depends on tumor size and the type of electrode used, but not on tumor type. An important factor for the prevention of local failure may be the acquisition of an adequate ablative margin. The combination of embolization and radiation therapy enhances the local efficacy. Local failure may be salvaged by repeating the radiofrequency ablation, particularly in small tumors. Survival rates after radiofrequency ablation are quite promising for patients with clinical stage I non-small cell lung cancer and pulmonary metastasis from colorectal cancer, hepatocellular carcinoma, and renal cell carcinoma. The complications caused by radiofrequency ablation can be treated conservatively in the majority of cases. However, attention should be paid to rare but serious complications. This review shows that radiofrequency ablation is a promising treatment for patients with lung cancer.

  7. The radio-frequency quadrupole

    CERN Document Server

    Vretenar, Maurizio

    2013-01-01

    Radio-frequency quadrupole (RFQ) linear accelerators appeared on the accelerator scene in the late 1970s and have since revolutionized the domain of low-energy proton and ion acceleration. The RFQ makes the reliable production of unprecedented ion beam intensities possible within a compact radio-frequency (RF) resonator which concentrates the three main functions of the low-energy linac section: focusing, bunching and accelerating. Its sophisticated electrode structure and strict beam dynamics and RF requirements, however, impose severe constraints on the mechanical and RF layout, making the construction of RFQs particularly challenging. This lecture will introduce the main beam optics, RF and mechanical features of a RFQ emphasizing how these three aspects are interrelated and how they contribute to the final performance of the RFQ.

  8. Precision radiative corrections to the semileptonic Dalitz plot with angular correlation between polarized decaying baryon and emitted charged lepton: Effects of the four-body region

    CERN Document Server

    Neri, M; García, A; Martínez, A; Torres, J J; Flores-Mendieta, Ruben

    2007-01-01

    Analytical radiative corrections of order (alpha/pi)(q/M) are calculated for the four-body region of the Dalitz plot of baryon semileptonic decays when the s1.l correlation is present. Once the final result is available, it is possible to exhibit it in terms of the corresponding final result of the three-body region following a set of simple changes in the latter, except for a few exceptions. We cover two cases, a charged and a neutral polarized decaying baryon.

  9. 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.

  10. A DSM-based “2.0” System for Human Intervention Planning and Scheduling in Facilities Emitting Ionizing Radiations

    CERN Document Server

    Baudin, M; De Jonghe, J

    2012-01-01

    To efficiently and safely plan, schedule and control its interventions in underground facilities, which are subject to ionizing radiations, CERN is currently developing a collaborative Web-based system. A similar project for maintenance management is also under way. On top of presenting their key requirements, this paper shows how the implementation of DSM can enhance a so-called Web 2.0 or collaborative dimension by bringing an intuitive and fair way of taking the dependencies between several activities into account. It is also discussed that the incoherencies brought in DSM by collaborative use (for instance regarding the time intervals) can be addressed by enlarging the binary DSM span of dependencies to ones of the Allen’s interval algebra or at least a subset of its dependencies.

  11. Long-lasting analgesic effect of radiofrequency treatment of the lumbosacral dorsal root ganglion

    NARCIS (Netherlands)

    Geurts, JWM; Wynne, HJ; van Wijk, R.

    2001-01-01

    Object. The authors conducted a study to establish the benefit of radiofrequency (RF) treatment of the lumbosacral dorsal root ganglion (DRG) as a therapy to reduce symptomatic pain in patients with chronic spinal pain radiating to the leg. Methods. Two hundred seventy-nine patients were evaluated a

  12. Therapy of HCC-radiofrequency ablation.

    Science.gov (United States)

    Buscarini, L; Buscarini, E

    2001-01-01

    Radiofrequency interstitial hyperthermia has been used for percutaneous ablation of hepatocellular carcinoma, under ultrasound guidance in local anesthesia. Conventional needle electrodes require a mean number of 3 sessions to treat tumors of diameter hemotorax in one case; a fluid collection in the site of ablated tumor in one patient treated by combination of transcatheter arterial embolization and radiofrequency application.

  13. Visible optical radiation generates bactericidal effect applicable for inactivation of health care associated germs demonstrated by inactivation of E. coli and B. subtilis using 405-nm and 460-nm light emitting diodes

    Science.gov (United States)

    Hönes, Katharina; Stangl, Felix; Sift, Michael; Hessling, Martin

    2015-07-01

    The Ulm University of Applied Sciences is investigating a technique using visible optical radiation (405 nm and 460 nm) to inactivate health-hazardous bacteria in water. A conceivable application could be point-of-use disinfection implementations in developing countries for safe drinking water supply. Another possible application field could be to provide sterile water in medical institutions like hospitals or dental surgeries where contaminated pipework or long-term disuse often results in higher germ concentrations. Optical radiation for disinfection is presently mostly used in UV wavelength ranges but the possibility of bacterial inactivation with visible light was so far generally disregarded. One of the advantages of visible light is, that instead of mercury arc lamps, light emitting diodes could be used, which are commercially available and therefore cost-efficient concerning the visible light spectrum. Furthermore they inherit a considerable longer life span than UV-C LEDs and are non-hazardous in contrast to mercury arc lamps. Above all there are specific germs, like Bacillus subtilis, which show an inactivation resistance to UV-C wavelengths. Due to the totally different deactivation mechanism even higher disinfection rates are reached, compared to Escherichia coli as a standard laboratory germ. By 460 nm a reduction of three log-levels appeared with Bacillus subtilis and a half log-level with Escherichia coli both at a dose of about 300 J/cm². By the more efficient wavelength of 405 nm four and a half log-levels are reached with Bacillus subtilis and one and a half log-level with Escherichia coli also both at a dose of about 300 J/cm². In addition the employed optical setup, which delivered a homogeneous illumination and skirts the need of a stirring technique to compensate irregularities, was an important improvement compared to previous published setups. Evaluated by optical simulation in ZEMAX® the designed optical element provided proven

  14. Cutaneous remodeling and photorejuvenation using radiofrequency devices

    Directory of Open Access Journals (Sweden)

    Elsaie Mohamed

    2009-01-01

    Full Text Available Radio frequency (RF is electromagnetic radiation in the frequency range of 3-300GHz. The primary effects of RF energy on living tissue are considered to be thermal. The goal of the new devices based on these frequency ranges is to heat specific layers of the skin. The directed use of RF can induce dermal heating and cause collagen degeneration. Wound healing mechanisms promote the remodeling of collagen and wound contraction, which ultimately clinically enhances the appearance of mild to moderate skin laxity. Preliminary studies have reported efficacy in the treatment of laxity that involves the periorbital area and jowls. Because RF energy is not dependent on specific chromophore interaction, epidermal melanin is not at risk of destruction and treatment of all skin types is possible. As such, radiofrequency-based systems have been used successfully for nonablative skin rejuvenation, atrophic scar revision and treatment of unwanted hair, vascular lesions and inflammatory acne. The use of RF is becoming more popular, although a misunderstanding exists regarding the mechanisms and limitations of its actions. This concise review serves as an introduction and guide to many aspects of RF in the non ablative rejuvenation of skin.

  15. 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...

  16. 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.

  17. 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.

  18. Radiofrequency field surveys in hospitals.

    Science.gov (United States)

    Foster, K R; Soltys, M; Arnofsky, S; Doshi, P; Hanover, D; Mercado, R; Schleck, D

    1996-01-01

    The authors surveyed levels of radiofrequency (RF) fields in the frequency range 0.1-1,000 MHz in four hospitals in the Philadelphia area, to obtain background information related to the possible interference of radiofrequency fields with medical equipment. Two large center-city hospitals, a regional county hospital, and two suburban hospitals were surveyed. Measurements were made at six to 12 sites in each hospital, in each of the three frequency bands. More limited additional measurements were conducted in a fifth hospital as well. Sites were selected to include areas where strong RF signals from transmitting antennas might be expected to be present (e.g., locations close to windows in upper stories of buildings near paging antennas) as well as other representative sites in the hospital. The median RF field strengths were quite low (0.1-0.5 V/m), but at specific locations the RF signals from broadcast sources exceeded 1 V/m. Much stronger fields were recorded close to electrosurgical units and hand-held transmitters (cellular telephones and UHF transceivers).

  19. Trigeminal Neuralgia and Radiofrequency Lesioning

    Directory of Open Access Journals (Sweden)

    Andy R. Eugene

    2015-12-01

    Full Text Available Trigeminal Neuralgia is a disorder that is characterized with electrical-type shocking pain in the face and jaw. This pain may either present as sharp unbearable pain unilateral or bilaterally. There is no definite etiology for this condition. There are various treatment methods that are currently being used to relieve the pain. One of the pharmacological treatments is Carbamazepine and the most prevalent surgical treatments include Gamma Knife Surgery (GKS, Microvascular Decompression (MVD and Radiofrequency Lesioning (RFL. Although, MVD is the most used surgical method it is not an option for all the patients due to the intensity of the procedure. RFL is used when MVD is not suitable. In this paper we present the various treatments and Monte-Carlo based pharmacokinetic simulations of Carbamazepine in treatment of Trigeminal Neuralgia.

  20. Light-emitting Diodes

    Science.gov (United States)

    Opel, Daniel R.; Hagstrom, Erika; Pace, Aaron K.; Sisto, Krisanne; Hirano-Ali, Stefanie A.; Desai, Shraddha

    2015-01-01

    Background: In the early 1990s, the biological significance of light-emitting diodes was realized. Since this discovery, various light sources have been investigated for their cutaneous effects. Study design: A Medline search was performed on light-emitting diode lights and their therapeutic effects between 1996 and 2010. Additionally, an open-label, investigator-blinded study was performed using a yellow light-emitting diode device to treat acne, rosacea, photoaging, alopecia areata, and androgenetic alopecia. Results: The authors identified several case-based reports, small case series, and a few randomized controlled trials evaluating the use of four different wavelengths of light-emitting diodes. These devices were classified as red, blue, yellow, or infrared, and covered a wide range of clinical applications. The 21 patients the authors treated had mixed results regarding patient satisfaction and pre- and post-treatment evaluation of improvement in clinical appearance. Conclusion: Review of the literature revealed that differing wavelengths of light-emitting diode devices have many beneficial effects, including wound healing, acne treatment, sunburn prevention, phototherapy for facial rhytides, and skin rejuvenation. The authors’ clinical experience with a specific yellow light-emitting diode device was mixed, depending on the condition being treated, and was likely influenced by the device parameters. PMID:26155326

  1. Power output and efficiency of beta-emitting microspheres

    Science.gov (United States)

    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.

  2. Examples of Radiation-Emitting Products

    Science.gov (United States)

    ... Slit lamp • Retinal acuity • Fluorescence spectroscopy • Transilluminator • Wound healing • Low-level laser therapy • PUVA therapy • Intra-operative ... ELF, magnetic • Magnetic resonance imaging • Hyperthermia • Diathermy • Bone healing • Wound healing • Prostate therapy • Electrocautery • Bone density measurement • ...

  3. Plutonium radiation surrogate

    Science.gov (United States)

    Frank, Michael I [Dublin, CA

    2010-02-02

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  4. 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).

  5. Radiation hazards of radio frequency waves on the early embryonic development of Zebrafish

    Science.gov (United States)

    Harkless, Ryan; Al-Quraishi, Muntather; Vagula, Mary C.

    2014-06-01

    With the growing use of wireless devices in almost all day-to-day activities, exposure to radio-frequency radiation has become an immediate health concern. It is imperative that the effects of such radiation not only on humans, but also on other organisms be well understood. In particular, it is critical to understand if RF radiation has any bearing on the gene expression during embryonic development, as this is a crucial and delicate phase for any organism. Owing to possible effects that RF radiation may have on gene expression, it is essential to explore the carcinogenic or teratogenic properties that it may show. This study observed the effects of RF radiation emitted from a cellular telephone on the embryonic development of zebra fish. The expression of the gene shha plays a key role in the early development of the fish. This gene has homologs in humans as well as in other model organisms. Additionally, several biomarkers indicative of cell stress were examined: including lactate dehydrogenase (LDH), superoxide dismutase (SOD), and lipid peroxidation (LPO). Results show a significant decrease in the expression of shha, a significant decrease in LDH activity. There was no significant increase in SOD and LPO activity. No morphological abnormalities were observed in the developing embryos. At present, these results indicate that exposure to cell phone radiation may have a suppressive effect on expression of shha in D. rerio, though such exposure does not appear to cause morphological detriments. More trials are underway to corroborate these results.

  6. 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.

  7. 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.

  8. The radiofrequency magnetic dipole discharge

    Science.gov (United States)

    Martines, E.; Zuin, M.; Marcante, M.; Cavazzana, R.; Fassina, A.; Spolaore, M.

    2016-05-01

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3-4 eV and higher in the cathode proximity. Plasma densities of the order of 1016 m-3 have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  9. Percutaneous radiofrequency thermal lumbar sympathectomy and its clinical use

    NARCIS (Netherlands)

    J. Pernak (Jamina)

    1988-01-01

    textabstractPercutaneous radiofrequency thermolesion techniques are commonly used in the treatment of chronic pain in different pain syndromes. There are many reports describing techniques of percutaneous radiofrequency thermolesion for denervation of central & spinal nerves (Mullan 1963), 1965,

  10. Light-Emitting Pickles

    Science.gov (United States)

    Vollmer, M.; Mollmann, K-P.

    2015-01-01

    We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

  11. Red Emitting VCSEL

    Science.gov (United States)

    Jetter, Michael; Roßbach, Robert; Michler, Peter

    This chapter describes the progress in development of vertical-cavity surface-emitting lasers (VCSEL) emitting in the red spectral region around 650 nm for data transmission over polymer optical fibers (POF). First, growth issues of red VCSEL using two different material systems, namely AlGaAs and AlGaInP, are introduced. In particular, the optical and electrical state-of-the-art characteristics as low threshold currents ({≤} 1 mA) and high output powers (several mW) are presented with a special focus on emission wavelength. Also the thermal budget and heat removal in the devices are pointed out with regard to the geometry of the VCSEL. Small-signal modulation response in terms of maximum resonance frequency in dependance on temperature behavior are discussed. Applications of these devices in optical interconnects are described and digital data transmission at data rates up to 2.1 Gbit/s over step-index POF is reported. These properties make red emitting VCSEL perfectly suited for high-speed low power consuming light sources for optical data communication via POF. By introducing InP quantum dots as gain material in red emitting VCSEL nearly temperature independent record low threshold current densities of around 10 A/cm2 could be observed.

  12. Light-Emitting Pickles

    Science.gov (United States)

    Vollmer, M.; Mollmann, K-P.

    2015-01-01

    We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

  13. 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... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce lesions in the nervous system or other tissue by the direct application of radiofrequency currents to...

  14. Radiations from GSM Base Stations and its Biological Effects on ...

    African Journals Online (AJOL)

    Michael Horsfall

    The levels of radiofrequency (RF) radiations around the base stations were found .... of Turk's solution (Glacial Acetic Acid tinted with ... dissolved in distilled, 40% formaldehyde) is balanced .... agencies in different countries have come up with.

  15. Bilateral vision loss associated with radiofrequency exposure

    Directory of Open Access Journals (Sweden)

    Liu D

    2012-12-01

    Full Text Available Dianna Liu, Franz Marie Cruz, Prem S SubramanianWilmer Eye Institute, The Johns Hopkins School of Medicine, Baltimore, Maryland, USAAbstract: A 57-year-old otherwise healthy woman presented with painless binocular vision loss 1 week after direct application of radiofrequency energy to her orbits. She had no light perception bilaterally. Pupils were dilated and not reactive to light. Fundoscopic exam initially showed optic disc swelling in the right eye and a normal-appearing disc in the left eye. Magnetic resonance imaging of the brain and orbits showed gadolinium enhancement of both intraorbital optic nerves. She underwent a course of high-dose steroid treatment without recovery of vision. Optic discs were pale 11 weeks after injury. With exclusion of other possible causes, this represents a unique case of irreversible binocular optic nerve damage and blindness secondary to radiofrequency exposure.Keywords: optic neuropathy, blindness, radiofrequency, vision loss

  16. Multiplexed infrared photodetection using resonant radio-frequency circuits

    Energy Technology Data Exchange (ETDEWEB)

    Liu, R.; Lu, R.; Gong, S.; Wasserman, D. [Department of Electrical and Computer Engineering, University of Illinois Urbana Champaign, Urbana, Illinois 61801 (United States); Roberts, C. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Allen, J. W.; Allen, M. S. [Air Force Research Laboratory, Munitions Directorate, Eglin Air Force Base, Florida 32542 (United States); Wenner, B. R. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States)

    2016-02-08

    We demonstrate a room-temperature semiconductor-based photodetector where readout is achieved using a resonant radio-frequency (RF) circuit consisting of a microstrip split-ring resonator coupled to a microstrip busline, fabricated on a semiconductor substrate. The RF resonant circuits are characterized at RF frequencies as function of resonator geometry, as well as for their response to incident IR radiation. The detectors are modeled analytically and using commercial simulation software, with good agreement to our experimental results. Though the detector sensitivity is weak, the detector architecture offers the potential for multiplexing arrays of detectors on a single read-out line, in addition to high speed response for either direct coupling of optical signals to RF circuitry, or alternatively, carrier dynamics characterization of semiconductor, or other, material systems.

  17. 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

  18. 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.)

  19. 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.

    Science.gov (United States)

    Meo, Sultan Ayoub; Alsubaie, Yazeed; Almubarak, Zaid; Almutawa, Hisham; AlQasem, Yazeed; Hasanato, Rana Muhammed

    2015-11-13

    Installation of mobile phone base stations in residential areas has initiated public debate about possible adverse effects on human health. This study aimed to determine the association of exposure to radio frequency electromagnetic field radiation (RF-EMFR) generated by mobile phone base stations with glycated hemoglobin (HbA1c) and occurrence of type 2 diabetes mellitus. For this study, two different elementary schools (school-1 and school-2) were selected. We recruited 159 students in total; 96 male students from school-1, with age range 12-16 years, and 63 male students with age range 12-17 years from school-2. Mobile phone base stations with towers existed about 200 m away from the school buildings. RF-EMFR was measured inside both schools. In school-1, RF-EMFR was 9.601 nW/cm² at frequency of 925 MHz, and students had been exposed to RF-EMFR for a duration of 6 h daily, five days in a week. In school-2, RF-EMFR was 1.909 nW/cm² at frequency of 925 MHz and students had been exposed for 6 h daily, five days in a week. 5-6 mL blood was collected from all the students and HbA1c was measured by using a Dimension Xpand Plus Integrated Chemistry System, Siemens. The mean HbA1c for the students who were exposed to high RF-EMFR was significantly higher (5.44 ± 0.22) than the mean HbA1c for the students who were exposed to low RF-EMFR (5.32 ± 0.34) (p = 0.007). Moreover, students who were exposed to high RF-EMFR generated by MPBS had a significantly higher risk of type 2 diabetes mellitus (p = 0.016) relative to their counterparts who were exposed to low RF-EMFR. It is concluded that exposure to high RF-EMFR generated by MPBS is associated with elevated levels of HbA1c and risk of type 2 diabetes mellitus.

  20. 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

    Directory of Open Access Journals (Sweden)

    Sultan Ayoub Meo

    2015-11-01

    Full Text Available Installation of mobile phone base stations in residential areas has initiated public debate about possible adverse effects on human health. This study aimed to determine the association of exposure to radio frequency electromagnetic field radiation (RF-EMFR generated by mobile phone base stations with glycated hemoglobin (HbA1c and occurrence of type 2 diabetes mellitus. For this study, two different elementary schools (school-1 and school-2 were selected. We recruited 159 students in total; 96 male students from school-1, with age range 12–16 years, and 63 male students with age range 12–17 years from school-2. Mobile phone base stations with towers existed about 200 m away from the school buildings. RF-EMFR was measured inside both schools. In school-1, RF-EMFR was 9.601 nW/cm2 at frequency of 925 MHz, and students had been exposed to RF-EMFR for a duration of 6 h daily, five days in a week. In school-2, RF-EMFR was 1.909 nW/cm2 at frequency of 925 MHz and students had been exposed for 6 h daily, five days in a week. 5–6 mL blood was collected from all the students and HbA1c was measured by using a Dimension Xpand Plus Integrated Chemistry System, Siemens. The mean HbA1c for the students who were exposed to high RF-EMFR was significantly higher (5.44 ± 0.22 than the mean HbA1c for the students who were exposed to low RF-EMFR (5.32 ± 0.34 (p = 0.007. Moreover, students who were exposed to high RF-EMFR generated by MPBS had a significantly higher risk of type 2 diabetes mellitus (p = 0.016 relative to their counterparts who were exposed to low RF-EMFR. It is concluded that exposure to high RF-EMFR generated by MPBS is associated with elevated levels of HbA1c and risk of type 2 diabetes mellitus.

  1. Creating Feshbach resonances for ultracold molecule formation with radio-frequency fields

    Science.gov (United States)

    Owens, Daniel J.; Xie, Ting; Hutson, Jeremy M.

    2016-08-01

    We show that radio-frequency (rf) radiation may be used to create Feshbach resonances in ultracold gases of alkali-metal atoms at desired magnetic fields that are convenient for atomic cooling and degeneracy. For the case of 39K+133Cs , where there are no rf-free resonances in regions where Cs may be cooled to degeneracy, we show that a resonance may be created near 21 G with 69.2 MHz rf radiation. This resonance is almost lossless with circularly polarized rf, and the molecules created are long-lived even with plane-polarized rf.

  2. Managing turbinate hypertrophy: coblation vs. radiofrequency treatment.

    Science.gov (United States)

    Passali, D; Loglisci, M; Politi, L; Passali, G C; Kern, E

    2016-06-01

    The role of inferior turbinate hypertrophy in the reduction of nasal airflow is well established. Although chronic nasal obstruction is not life- threatening, it significantly impairs patients' quality of life, affecting many aspects of daily activities; therefore, patients seek medical intervention. 40 patients were selected (27 males and 13 females) between 27 and 64 years of age with a symptom of nasal obstruction. The patients were divided in two groups: Group 1: coblation, 25 patients (18 males and 7 females); Group 2: radiofrequency, 15 patients (7 males and 6 females). These 40 patients were followed for 3 years. Patients were analyzed using both subjective and objective methods. The visual analog scale (VAS) subjective data and objective data including both active anterior rhinomanometry and acoustic rhinometry were recorded and analyzed. Data were collected pre-operatively and at 1 and 3 years post-operatively. According to our data, both coblation and radiofrequency turbinate reduction benefit patients with good results. The complications, found during the follow-up, are limited to minimal bleeding and crusting. Coblation and radiofrequency were significantly less painful than others procedures during the early post-operative period. In our study, both coblation and radiofrequency provide an improvement in nasal airflow with a reduction in nasal obstructive symptoms in the short term, but their efficacy tended to decrease within 3 years.

  3. Radiofrequency for the treatment of liver tumours.

    NARCIS (Netherlands)

    Ruers, T.J.M.; Jong, K.P. de; Ijzermans, J.N.M.

    2005-01-01

    Resection should still be considered the gold standard for many liver tumours. There is, however, growing interest in the use of radiofrequency (RFA) for the treatment of liver tumours. By RFA, tumour tissue can be destructed selectively without significant damage to vascular structures in the

  4. Radiofrequency for the treatment of liver tumours

    NARCIS (Netherlands)

    Ruers, TJM; de Jong, KP; Ijzermans, JNM

    2005-01-01

    Resection should still be considered the gold standard for many liver tumours. There is, however, growing interest in the use of radiofrequency (RFA) for the treatment of liver tumours. By RFA, tumour tissue can be destructed selectively without significant damage to vascular structures in the

  5. Light Emitting Porous Silicon

    Science.gov (United States)

    1993-05-01

    ml - mm m lm m ~ m m ThO report Page 14 preparation method which has been originally described by Wohler [23] leads to a bright yellow substance with...Solid State Commun. 81, 307 (1992). [221 H. Kautsky, and H. Zocher, Z. Phys. 9,267 (1992). L TNO report Page 28 [231 F. Wohler , Lieb. Ann. 127, 275 (1863...Netherlands Fax + 31 70 328 09 61 Phone + 31 70 326 42 21 TNO- report copy no. e FEL-93eo047r Lh Emitting Porous Silicon sitho(s): DTICHMi.P.Th

  6. Achieving low-emissivity materials with high transmission for broadband radio-frequency signals.

    Science.gov (United States)

    Liu, Liu; Chang, Huiting; Xu, Tao; Song, Yanan; Zhang, Chi; Hang, Zhi Hong; Hu, Xinhua

    2017-07-07

    The use of low-emissivity (low-e) materials in modern buildings is an extremely efficient way to save energy. However, such materials are coated by metallic films, which can strongly block radio-frequency signals and prevent indoor-outdoor wireless communication. Here, we demonstrate that, when specially-designed metallic metasurfaces are covered on them, the low-e materials can remain low emissivity for thermal radiation and allow very high transmission for a broad band of radio-frequency signals. It is found that the application of air-connected metasurfaces with subwavelength periods is critical to the observed high transmission. Such effects disappear if periods are comparable to wavelengths or metal-connected structures are utilized. The conclusion is supported by both simulations and experiments. Advantages such as easy to process, low cost, large-area fabrication and design versatility of the metasurface make it a promising candidate to solve the indoor outdoor communication problem.

  7. Ocular effects of radiofrequency energy.

    Science.gov (United States)

    Elder, J A

    2003-01-01

    Radiofrequency (RF) energy has been reported to cause a variety of ocular effects, primarily cataracts but also effects on the retina, cornea, and other ocular systems. Cataracts have been observed in experimental animals when one eye was exposed to a localized, very high RF field and the other eye was the unexposed control. The results show that 2450 MHz exposures for >or=30 min at power densities causing extremely high dose rates (>or=150 W/kg) and temperatures (>or=41 degrees C) in or near the lens caused cataracts in the rabbit eye. However, cataracts were not observed in the monkey eye exposed to similar exposure conditions, reflecting the different patterns of energy absorption (SAR, specific absorption rate) distribution, due to their different facial structure. Since the monkey head is similar in structure to the human head, the nonhuman primate study showed that the incident power density levels causing cataracts in rabbits and other laboratory animals cannot be directly extrapolated to primates, including human beings. It is reasonable to assume that an SAR that would induce temperatures >or=41 degrees C in or near the lens in the human eye would produce cataracts by the same mechanism (heating) that caused cataracts in the rabbit lens; however, such an exposure would greatly exceed the currently allowable limits for human exposure and would be expected to cause unacceptable effects in other parts of the eye and face. Other ocular effects including corneal lesions, retinal effects, and changes in vascular permeability, have been observed after localized exposure of the eye of laboratory animals to both continuous wave (CW) and pulsed wave (PW) exposures, but the inconsistencies in these results, the failure to independently confirm corneal lesions after CW exposure, the failure to independently confirm retinal effects after PW exposure, and the absence of functional changes in vision are reasons why these ocular effects are not useful in defining an

  8. 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.

  9. The optimal radiofrequency temperature in radiofrequency thermocoagulation for idiopathic trigeminal neuralgia

    Science.gov (United States)

    Tang, Yuan-Zhang; Yang, Li-Qiang; Yue, Jian-Ning; Wang, Xiao-Ping; HE, Liang-Liang; NI, Jia-Xiang

    2016-01-01

    Abstract Objective: Our previous study evaluated the effectiveness and safety of radiofrequency thermocoagulation (RFT) of trigeminal gasserian ganglion for idiopathic trigeminal neuralgia (ITN). The aim of this study was to evaluate the optimal radiofrequency temperature of computed tomography (CT)-guided RFT for treatment of ITN. Methods: A retrospective study of patients with ITN treated with a single CT-guided RFT procedure between January 2002 and December 2013. Patients were divided into ≤75 °C, 75 °C, and ≥80 °C groups according to the highest radiofrequency temperature used. Pain relief was graded from poor to excellent, and facial numbness/dysesthesia from I (absent) to IV (most severe). Results: A total of 1161 RFT procedures were undertaken in the 1137 patients. The mean follow-up time was 46 ± 31 months. There were no significant differences in the rate of excellent pain relief according to the radiofrequency temperature used. However, more patients experienced with no facial numbness or facial numbness gradually resolved and those patients treated at 75 °C had a lower rate of grade IV facial numbness/dysesthesia than other groups. Conclusions: The optimal radiofrequency temperature to maximize pain relief and minimize facial numbness or dysesthesia may be 75 °C, but this requires confirmation. PMID:27428194

  10. Dose-dependent and gender-related radiation-induced transcription alterations of Gadd45a and Ier5 inhuman lymphocytes exposed to gamma ray emitted by (60)Co.

    Science.gov (United States)

    Tavakoli, Hassan; Manoochehri, Mahdi; Modarres Mosalla, Sayed Mahdi; Ghafori, Mostafa; Karimi, Ali Akbar

    2013-04-01

    Growth arrest DNA damage-inducible 45a gene (Gadd45a) and immediate early response gene 5 (Ier5) have been emphasised as ideal radiation biomarkers in several reports. However, some aspects of radiation-induced transcriptional alterations of these genes are unknown. In this study, gender-dependency and dose-dependency as two factors that may affect radiation-induced transcription of Gadd45a and Ier5 genes were investigated. Human lymphocyte cells from six healthy voluntary blood donors (three women and three men) were irradiated in vitro with doses of 0.5-4.0 Gy from a (60)Co source and RNA isolated 4 h later using the High Pure RNA Isolation Kit. Dose and gender dependency of radiation-induced transcriptional alterations of Gadd45a and Ier5 genes were studied by quantitative real-time polymerase chain reaction. The results showed that as a whole, Gadd45a and Ier5 gave responses to gamma rays, while the responses were independent of radiation doses. Therefore, regardless of radiation dose, Gadd45a and Ier5 can be considered potential radiation biomarkers. Besides, although radiation-induced transcriptional alterations of Gadd45a in female and male lymphocyte samples were insignificant at 0.5 Gy, at other doses, their quantities in female samples were at a significantly higher level than in male samples. Radiation-induced transcription of Ier5 of females samples had a reduction in comparison with male samples at 1 and 2 Gy, but at doses of 0.5 and 4 Gy, females were significantly more susceptible to radiation-induced transcriptional alteration of Ier5.

  11. 75 FR 80827 - Compliance Policy Guide; Radiofrequency Identification Feasibility Studies and Pilot Programs for...

    Science.gov (United States)

    2010-12-23

    ...; Radiofrequency Identification Feasibility Studies and Pilot Programs for Drugs; Notice To Extend Expiration Date...) Sec. 400.210 entitled ``Radiofrequency Identification (RFID) Feasibility Studies and Pilot Programs... ``Radiofrequency Identification (RFID) Feasibility Studies and Pilot Programs for Drugs.'' Previous extensions...

  12. 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.

  13. 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.

  14. ROLE OF RADIOFREQUENCY ABLATION IN ADENOMA SEBACEUM

    Directory of Open Access Journals (Sweden)

    Ch. Madh

    2016-03-01

    Full Text Available Adenoma sebaceum, pathognomonic of tuberous sclerosis, are tiny angiofibromas which commonly occur over central part of face. Recurrence after treatment is common and hence a need for inexpensive, safe and efficient treatment is required. Radiofrequency ablation is a safe and an economical procedure and has been known to cause less scarring with good aesthetic results compared to other ablative methods such as electrocautery.

  15. Radiofrequency tonsillotomy in Sweden 2009-2012.

    Science.gov (United States)

    Sunnergren, Ola; Hemlin, Claes; Ericsson, Elisabeth; Hessén-Söderman, Anne-Charlotte; Hultcrantz, Elisabeth; Odhagen, Erik; Stalfors, Joacim

    2014-06-01

    The Swedish National Registry for Tonsil Surgery has been operational since 1997. All ENT clinics in Sweden are encouraged to submit data for all patients scheduled for tonsil surgery. Preoperatively, age, gender and indication are recorded. Postoperatively, method (tonsillectomy or tonsillotomy), technique, and perioperative complications are recorded. Postoperative bleedings, pain, infections, and symptom relief are assessed through questionnaires. An earlier report from this registry showed that tonsillotomy had become more common than tonsillectomy in children with tonsil-related upper airway obstruction. The aim of this study was to categorize which instruments were used for tonsillotomy in Sweden and to compare their outcome and complication rate. All children 2-18 years, reported to the registry from March 2009 until September 2012, who underwent tonsillotomy on the indication upper airway obstruction, were included in the study. 1,676 patients were identified. In 1,602 cases (96%), a radiofrequency instrument was used. The postoperative bleeding rate was low (1.2%) and the degree of symptom relief was high (95.1%). Three different radiofrequency instruments (ArthroCare Coblation(®), Ellman Surgitron(®), and Sutter CURIS(®)) were used in 96% of the patients. There were no significant differences in the number of postoperative bleedings, postoperative infections or symptom relief between the instruments. The only difference found was in the number of days on analgesics, where more days were registered after use of Coblation(®). In Sweden, radiofrequency tonsillotomy is the dominant surgical technique used for tonsil hypertrophy causing upper airway obstruction in children. There are no significant differences in outcome between the different radiofrequency instruments except for number of days on analgesics after surgery.

  16. Radiofrequency Microtenotomy for Elbow Epicondylitis: Midterm Results.

    Science.gov (United States)

    Tasto, James P; Richmond, John M; Cummings, Jeffrey R; Hardesty, Renee; Amiel, David

    2016-01-01

    We conducted a prospective, nonrandomized, single-center clinical study to evaluate the safety and midterm effectiveness of microtenotomy using a radiofrequency probe to treat chronic tendinosis of the elbow. All patients had failed conservative treatment for 6 months. The radiofrequency-based microtenotomy was performed using the Topaz Microdebrider (ArthroCare). Patients were followed annually for up to 9 years postoperatively. Pain status was documented using a visual analog scale self-reported measure. Eighty consecutive patients with tendinosis of the elbow were enrolled; 69 patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The duration of follow-up ranged from 6 months to 9 years (mean, 2.5 years). Ninety-one percent of the patients reported a successful outcome. Within the lateral epicondylitis group, the preoperative visual analog scale improved from 6.9 to 1.3 postoperatively and demonstrated an 81% improvement (P ≤ .01). For the medial epicondylitis patients, the preoperative visual analog scale improved from 6.1 to 1.3 after surgery, a 79% improvement (P ≤ .01). No complications were reported. Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed at 9 years after surgery.

  17. Determination of the exposure speed of radiation emitted by the linear accelerator, using the code MCNP5 to evaluate the radiotherapy room shields of ABC Hospital; Determinacion de la rapidez de exposicion de la radiacion emitida por el acelerador lineal, utilizando el codigo MCNP5, para evaluar los blindajes de la sala de radioterapia del Hospital ABC

    Energy Technology Data Exchange (ETDEWEB)

    Corral B, J. R.

    2015-07-01

    Humans should avoid exposure to radiation, because the consequences are harmful to health. Although there are different emission sources of radiation, generated by medical devices they are usually of great interest, since people who attend hospitals are exposed in one way or another to ionizing radiation. Therefore, is important to conduct studies on radioactive levels that are generated in hospitals, as a result of the use of medical equipment. To determine levels of exposure speed of a radioactive facility there are different methods, including the radiation detector and computational method. This thesis uses the computational method. With the program MCNP5 was determined the speed of the radiation exposure in the radiotherapy room of Cancer Center of ABC Hospital in Mexico City. In the application of computational method, first the thicknesses of the shields were calculated, using variables as: 1) distance from the shield to the source; 2) desired weekly equivalent dose; 3) weekly total dose equivalent emitted by the equipment; 4) occupation and use factors. Once obtained thicknesses, we proceeded to model the bunker using the mentioned program. The program uses the Monte Carlo code to probabilistic ally determine the phenomena of interaction of radiation with the shield, which will be held during the X-ray emission from the linear accelerator. The results of computational analysis were compared with those obtained experimentally with the detection method, for which was required the use of a Geiger-Muller counter and the linear accelerator was programmed with an energy of 19 MV with 500 units monitor positioning the detector in the corresponding boundary. (Author)

  18. USAF Radiofrequency Radiation Bioeffects Research Program - A Review

    Science.gov (United States)

    1981-12-01

    initial slope of the curve is P divided by Kpc . By recording the femperature increase versus time at sutcessive 1-cm depth of the brain of the animal...in mutation rates of genes of prokaryotic (bacteria and/or bacterio-phage) and eukaryotic (saccharomyces species) organisms by irradistion at closely

  19. Subcellular Responses to Narrowband and Wideband Radiofrequency Radiation

    Science.gov (United States)

    2008-02-15

    Lumpur, Malaysia , June 4-6, 2007. (in press). U. Pliquett, T. Nacke, and K. Schoenbach, "High frequency and low concentration - limitation for...Weintraub, Ph.D, Co-Investigator Mohan Natarajan, Ph.D, Co-Investigator Bijaya Nayak, Ph.D. Norma Vela- Roche , M.S. Cynthia Galindo, B.S. Kevin Hakalah

  20. 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.

  1. An Analysis of the Far-Field Radiation Pattern of the Ultraviolet Light-Emitting Diode (LED) Engin LZ4-00UA00 Diode with and without Beam Shaping Optics

    Science.gov (United States)

    2015-09-01

    5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Karl K Klett Jr 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7...light-emitting diode (LED), with and without beam shaping optics. This LED has 4 emitters arranged in a square pattern that are off-center from the...in this work that the spectra of the LED, the Lexan LS2 polycarbonate, and the ThorLabs FES0450, 450-nm shortpass filter are correct, as specified in

  2. 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 scinti

  3. Light Emitting Diodes (LEDs)

    Science.gov (United States)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique, called Photodynamic Therapy, requires the surgeon to use tiny, pinhead-size Light Emitting Diodes (LEDs) (a source that releases long wavelengths of light ) to activate light-sensitive, tumor-treating drugs. 'A young woman operated on in May 1999 has fully recovered with no complications and no evidence of the tumor coming back,' said Dr. Harry Whelan, a pediatric neurologist at the Medical Hospital of Wisconsin in Milwaukee. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can be used for hours at a time while still remaining cool to the touch. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The LEDs, developed and managed by NASA's Marshall Space Flight Center, have been used on seven Space Shuttle flights inside the Microgravity Astroculture Facility. This technology has also been successfully used to further commercial research in crop growth.

  4. Spectrochemical studies with {beta}-emitting radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Chesta, Miguel A.; Plivelic, Tomas S.; Mainardi, Raul T. [Cordoba Univ. Nacional (Argentina). Facultad de Matematica, Atronomia y Fisica

    1997-12-01

    Electrons emitted by {sup 90} Sr radioactive source and positrons from a {sup 22} Na source were used to produce ionizations in the constituents of a sample. The sources have similar energy spectra and this allowed us to compare the characteristic radiation emission efficiencies. The new proposed experimental set up for radioisotope excited x-ray fluorescence analysis (XRFA) is of a transparent source type and provides at least a ten times increase in the intensity of characteristic x-rays emitted by the sample as compared with a standard set up in XRFA. It is shown that this fact, together with the relatively high energy of the beta particles, make it possible to carry out a mirror elemental analysis in a few minutes using low intensity radioactive sources (no special handling license). Preliminary experimental results are shown using both electrons and positrons impinging on pure and composed samples and simple analytical expressions are provided for the characteristic radiation intensity as detected by an HPGe detector. (author). 7 refs., 4 figs.

  5. Adaptive Response Induced by Pre-Exposure to 915 MHz Radiofrequency: A Possible Role for Antioxidant Enzyme Activity.

    Science.gov (United States)

    Mortazavi, S M J; Mostafavi-Pour, Z; Daneshmand, M; Zal, F; Zare, R; Mosleh-Shirazi, M A

    2017-06-01

    Over the past few years, the rapid use of high frequency electromagnetic fields like mobile phones has raised global concerns about the negative health effects of its use. Adaptive response is the ability of a cell or tissue to better resist stress damage by prior exposure to a lesser amount of stress. This study aimed to assess whether radiofrequency radiation can induce adaptive response by changing the antioxidant balance. In order to assess RF-induced adaptive response in tissues, we evaluated the level of GSH and the activity of GR in liver. 50 rats were divided into 5 groups. Three groups were pre-exposed to 915 MHz RF radiation, 4 hours per day for one week at different powers, as low, medium and high. 24 hours after the last exposure to radiation, they were exposed to 4 Gy sublethal dose of gamma radiation and then sacrificed after 5 hours. Their livers were removed, washed and were kept at -80o C until used. Our finding showed that pre-exposure to 915 MHz radiofrequency radiation with specific power could induce adaptive response in liver by inducing changes in the activity and level of antioxidant enzymes. It can be concluded that pre-exposure to microwave radiation could increase the level of GSH and the activity of GR enzyme, although these increases were seen just in low power group, and the GR activity was indicated in medium power group. This increase protects tissue from oxidative damage induced by sublethal dose of gamma radiation.

  6. Powerful infrared emitting diodes

    Directory of Open Access Journals (Sweden)

    Kogan L. M.

    2012-02-01

    Full Text Available Powerful infrared LEDs with emission wavelength 805 ± 10, 870 ± 20 and 940 ± 10 nm developed at SPC OED "OPTEL" are presented in the article. The radiant intensity of beam diode is under 4 W/sr in the continuous mode and under 100 W/sr in the pulse mode. The radiation power of wide-angle LEDs reaches 1 W in continuous mode. The external quantum efficiency of emission IR diodes runs up to 30%. There also has been created infrared diode modules with a block of flat Fresnel lenses with radiant intensity under 70 W/sr.

  7. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation

    DEFF Research Database (Denmark)

    Cosedis Nielsen, Jens; Johannessen, Arne; Raatikainen, Pekka;

    2012-01-01

    There are limited data comparing radiofrequency catheter ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation.......There are limited data comparing radiofrequency catheter ablation with antiarrhythmic drug therapy as first-line treatment in patients with paroxysmal atrial fibrillation....

  8. 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.)

  9. Genetic effects of radio-frequency, atmospheric-pressure glow discharges with helium

    Science.gov (United States)

    Li, Guo; Li, He-Ping; Wang, Li-Yan; Wang, Sen; Zhao, Hong-Xin; Sun, Wen-Ting; Xing, Xin-Hui; Bao, Cheng-Yu

    2008-06-01

    Due to low gas temperatures and high densities of active species, atmospheric-pressure glow discharges (APGDs) would have potential applications in the fields of plasma-based sterilization, gene mutation, etc. In this letter, the genetic effects of helium radio-frequency APGD plasmas with the plasmid DNA and oligonucleotide as the treated biomaterials are presented. The experimental results show that it is the chemically active species, instead of heat, ultraviolet radiation, intense electric field, and/or charged particles, that break the double chains of the plasmid DNA. The genetic effects depend on the plasma operating parameters, e.g., power input, helium flow rate, processing distance, time, etc.

  10. Moessbauer absorption by thick ferromagnets in radio-frequency magnetic field

    CERN Document Server

    Dzyublik, A Y

    2002-01-01

    The dynamical scattering theory is developed for transmission of the Moessbauer radiation through a ferromagnetic absorber of arbitrary thickness whose magnetization periodically reverses under the influence of an external radio-frequency (RF) magnetic field. The thickness dependence of the Moessbauer absorption spectrum as well as the time dependence and energy distribution of the transmitted beam are analyzed. The transmitted spectrum as a function of the frequency of transmitted gamma-quanta, reveals a sideband structure separated by twice the frequency of the RF field, which collapses to a single line at high frequencies.

  11. Energy Saving Glass Lamination via Selective Radio-Frequency Heating

    Energy Technology Data Exchange (ETDEWEB)

    Shulman, Holly S.; Allan, Shawn M.

    2009-11-11

    This Inventions and Innovations program supported the technical and commercial research and development needed to elevate Ceralink's energy saving process for flat glass lamination from bench scale to a self-supporting technology with significant potential for growth. Radio-frequency heating was any un-explored option for laminating glass prior to this program. With significant commercial success through time and energy savings in the wood, paper, and plastics industries, RF heating was found to have significant promise for the energy intensive glass lamination industry. A major technical goal of the program was to demonstrate RF lamination across a wide range of laminate sizes and materials. This was successfully accomplished, dispelling many skeptics' concerns about the abilities of the technology. Ceralink laminated panels up to 2 ft x 3 ft, with four sets processed simultaneously, in a 3 minute cycle. All major categories of interlayer materials were found to work with RF lamination. In addition to laminating glass, other materials including photovoltaic silicon solar cells, light emitting diodes, metallized glass, plastics (acrylic and polycarbonate), and ceramics (alumina) were found compatible with the RF process. This opens up a wide range of commercial opportunities beyond the initially targeted automotive industry. The dramatic energy savings reported for RF lamination at the bench scale were found to be maintained through the scale up of the process. Even at 2 ft x 3 ft panel sizes, energy savings are estimated to be at least 90% compared to autoclaving or vacuum lamination. With targeted promotion through conference presentations, press releases and internet presence, RF lamination has gained significant attention, drawing large audiences at American Ceramic Society meetings. The commercialization success of the project includes the establishment of a revenue-generating business model for providing process development and demonstrations for

  12. Gravitational waves emitted by a particle rotating around a Schwarzschild black hole: A semiclassical approach

    Science.gov (United States)

    Bernar, Rafael P.; Crispino, Luís C. B.; Higuchi, Atsushi

    2017-03-01

    We analyze the gravitational radiation emitted from a particle in circular motion around a Schwarzschild black hole using the framework of quantum field theory in curved spacetime at tree level. The gravitational perturbations are written in a gauge-invariant formalism for spherically symmetric spacetimes. We discuss the results, comparing them to the radiation emitted by a particle when it is assumed to be orbiting a massive object due to a Newtonian force in flat spacetime.

  13. Radiofrequency energy in surgery: state of the art.

    Science.gov (United States)

    Ihnát, Peter; Ihnát Rudinská, Lucia; Zonča, Pavel

    2014-06-01

    Over a period of more than 100 years, radiofrequency energy has been introduced in many fields and applications in medicine. At present, radiofrequency constitutes the basis of numerous medical devices employed in almost all medical specialties. It is particularly applicable and valuable in various minimally invasive procedures for its locally focused effects. Radiofrequency energy is a technical term established to describe high-frequency alternating electrical currents (with a frequency ranging from 300 kHz to 3 MHz) and their impact on biological tissue. The application of RF energy causes controlled tissue heating with consequent cell protein denaturation and desiccation, which leads to cell death and tissue destruction. The primary principle of radiofrequency is that the generated heat can be used to cut, coagulate or induce metabolic processes in the target tissue. The authors of this paper offer a comprehensive and compact review of the definition, history, physics, biological principles and applications of radiofrequency energy in current surgery.

  14. Radio-frequency measurement in semiconductor quantum computation

    Science.gov (United States)

    Han, TianYi; Chen, MingBo; Cao, Gang; Li, HaiOu; Xiao, Ming; Guo, GuoPing

    2017-05-01

    Semiconductor quantum dots have attracted wide interest for the potential realization of quantum computation. To realize efficient quantum computation, fast manipulation and the corresponding readout are necessary. In the past few decades, considerable progress of quantum manipulation has been achieved experimentally. To meet the requirements of high-speed readout, radio-frequency (RF) measurement has been developed in recent years, such as RF-QPC (radio-frequency quantum point contact) and RF-DGS (radio-frequency dispersive gate sensor). Here we specifically demonstrate the principle of the radio-frequency reflectometry, then review the development and applications of RF measurement, which provides a feasible way to achieve high-bandwidth readout in quantum coherent control and also enriches the methods to study these artificial mesoscopic quantum systems. Finally, we prospect the future usage of radio-frequency reflectometry in scaling-up of the quantum computing models.

  15. Radiofrequency ablation for benign thyroid nodules.

    Science.gov (United States)

    Bernardi, S; Stacul, F; Zecchin, M; Dobrinja, C; Zanconati, F; Fabris, B

    2016-09-01

    Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

  16. Emissive Ion Thruster -EMIT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A propulsion system is proposed that is based on acceleration of ions emitted from a thin, solid-state electrochemical ceramic membrane. This technology would...

  17. Electrochemical Light-Emitting Gel

    Directory of Open Access Journals (Sweden)

    Nobuyuki Itoh

    2010-06-01

    Full Text Available Light-emitting gel, a gel state electroluminescence material, is reported. It is composed of a ruthenium complex as the emitter, an ionic liquid as the electrolyte, and oxide nanoparticles as the gelation filler. Emitted light was produced via electrogenerated chemiluminescence. The light-emitting gel operated at low voltage when an alternating current was passed through it, regardless of its structure, which is quite thick. The luminescence property of the gel is strongly affected by nanoparticle materials. TiO2 nanoparticles were a better gelation filler than silica or ZnO was, with respect to luminescence stability, thus indicating a catalytic effect. It is demonstrated that the light-emitting gel device, with quite a simple fabrication process, flashes with the application of voltage.

  18. Bilateral Intra-Articular Radiofrequency Ablation for Cervicogenic Headache

    Science.gov (United States)

    Tang, Teresa; Taftian, David; Chhatre, Akhil

    2017-01-01

    Introduction. Cervicogenic headache is characterized by unilateral neck or face pain referred from various structures such as the cervical joints and intervertebral disks. A recent study of patients with cervical pain showed significant pain relief after cervical medial branch neurotomy but excluded patients with C1-2 joint pain. It remains unclear whether targeting this joint has potential for symptomatic relief. To address this issue, we present a case report of C1-2 joint ablation with positive outcomes. Case Presentation. A 27-year-old female presented with worsening cervicogenic headache. Her pain was 9/10 by visual analog scale (VAS) and described as cramping and aching. Pain was localized suboccipitally with radiation to her jaw and posterior neck, worse on the right. Associated symptoms included clicking of her temporomandibular joint, neck stiffness, bilateral headaches with periorbital pain, numbness, and tingling. History, physical exam, and diagnostic studies indicated localization to the C1-2 joint with 80% decrease in pain after C1-2 diagnostic blocks. She underwent bilateral intra-articular radiofrequency ablation of the C1-C2 joint. Follow-up at 2, 4, 8, and 12 weeks showed improved function and pain relief with peak results at 12 weeks. Conclusion. Clinicians may consider C1-C2 joint ablation as a viable long-term treatment option for cervicogenic headaches. PMID:28149652

  19. Radiofrequency Exposure Amongst Employees of Mobile Network Operators and Broadcasters.

    Science.gov (United States)

    Litchfield, Ian; van Tongeren, Martie; Sorahan, Tom

    2016-10-13

    Little is known about personal exposure to radiofrequency (RF) fields amongst employees in the telecommunications industry responsible for installing and maintaining transmitters. IARC classified RF exposure as a possible carcinogen, although evidence from occupational studies was judged to be inadequate. Hence, there is a need for improved evidence of any potentially adverse health effects amongst the workforce occupationally exposed to RF radiation. In this study, results are presented from an exposure survey using data from personal monitors used by employees in the broadcasting and telecommunication industries of the UK. These data were supplemented by spot measurements using broadband survey metres and information on daily work activities provided by employee questionnaires. The sets of real-time personal data were categorised by four types of site determined by the highest powered antenna present (high, medium or low power and ground-level sites). For measurements gathered at each type of site, the root mean square and a series of box plots were produced. Results from the daily activities diaries suggested that riggers working for radio and television broadcasters were exposed to much longer periods as compared to colleagues working for mobile operators. Combining the results from the measurements and daily activity diaries clearly demonstrate that exposures were highest for riggers working for broadcasting sites. This study demonstrates that it is feasible to carry out exposure surveys within these populations that will provide reliable estimates of exposure that can be used for epidemiological studies of occupational groups exposed to RF fields.

  20. Compact Superconducting Radio-frequency Accelerators and Innovative RF Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kephart, Robert [Fermilab; Chattopadhyay, Swaapan [Northern Illinois U.; Milton, Stephen [Colorado State U.

    2015-04-10

    We will present several new technical and design breakthroughs that enable the creation of a new class of compact linear electron accelerators for industrial purposes. Use of Superconducting Radio-Frequency (SRF) cavities allow accelerators less than 1.5 M in length to create electron beams beyond 10 MeV and with average beam powers measured in 10’s of KW. These machines can have the capability to vary the output energy dynamically to produce brehmstrahlung x-rays of varying spectral coverage for applications such as rapid scanning of moving cargo for security purposes. Such compact accelerators will also be cost effective for many existing and new industrial applications. Examples include radiation crosslinking of plastics and rubbers, creation of pure materials with surface properties radically altered from the bulk, modification of bulk or surface optical properties of materials, sterilization of medical instruments animal solid or liquid waste, and destruction of organic compounds in industrial waste water effluents. Small enough to be located on a mobile platform, such accelerators will enable new remediation methods for chemical and biological spills and/or in-situ crosslinking of materials. We will describe one current design under development at Fermilab including plans for prototype and value-engineering to reduce costs. We will also describe development of new nano-structured field-emitter arrays as sources of electrons, new methods for fabricating and cooling superconducting RF cavities, and a new novel RF power source based on magnetrons with full phase and amplitude control.

  1. Radio-frequency scanning tunnelling microscopy.

    Science.gov (United States)

    Kemiktarak, U; Ndukum, T; Schwab, K C; Ekinci, K L

    2007-11-01

    The scanning tunnelling microscope (STM) relies on localized electron tunnelling between a sharp probe tip and a conducting sample to attain atomic-scale spatial resolution. In the 25-year period since its invention, the STM has helped uncover a wealth of phenomena in diverse physical systems--ranging from semiconductors to superconductors to atomic and molecular nanosystems. A severe limitation in scanning tunnelling microscopy is the low temporal resolution, originating from the diminished high-frequency response of the tunnel current readout circuitry. Here we overcome this limitation by measuring the reflection from a resonant inductor-capacitor circuit in which the tunnel junction is embedded, and demonstrate electronic bandwidths as high as 10 MHz. This approximately 100-fold bandwidth improvement on the state of the art translates into fast surface topography as well as delicate measurements in mesoscopic electronics and mechanics. Broadband noise measurements across the tunnel junction using this radio-frequency STM have allowed us to perform thermometry at the nanometre scale. Furthermore, we have detected high-frequency mechanical motion with a sensitivity approaching approximately 15 fm Hz(-1/2). This sensitivity is on par with the highest available from nanoscale optical and electrical displacement detection techniques, and the radio-frequency STM is expected to be capable of quantum-limited position measurements.

  2. Pulmonary radiofrequency ablation (Part 1): current state.

    Science.gov (United States)

    Plasencia Martínez, J M

    2015-01-01

    The risks involved in surgical treatment and conventional radiotherapy in patients with early lung cancer or lung metastases often make these treatments difficult to justify. However, on the other hand, it is also unacceptable to allow these lesions to evolve freely because, left untreated, these neoplasms will usually lead to the death of the patient. In recent years, alternative local therapies have been developed, such as pulmonary radiofrequency ablation, which has proven to increase survival with a minimal risk of complications. There are common recommendations for these treatments, and although the specific indications for using one technique or another have yet to be established, there are clearly defined situations that will determine the outcome of the treatment. It is important to know these situations, because appropriate patient selection is essential for therapeutic success. This article aims to describe the characteristics and constraints of pulmonary radiofrequency ablation and to outline its role in thoracic oncology in light of the current evidence. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  3. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    Science.gov (United States)

    Evtushenko, A. V.; Evtushenko, V. V.; Saushkina, Yu. V.; Lishmanov, Yu. B.; Pokushalov, E. A.; Sergeevichev, D. S.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V.; Anfinogenova, Ya. D.; Smyshlyaev, K. A.; Lotkov, A. I.; Kurlov, I. O.

    2015-11-01

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using 123I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  4. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, A. V., E-mail: ave@cardio-tomsk.ru; Evtushenko, V. V. [National Research Tomsk State University, Tomsk (Russian Federation); Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Saushkina, Yu. V.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Smyshlyaev, K. A.; Kurlov, I. O. [Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Lishmanov, Yu. B.; Anfinogenova, Ya. D. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Sergeevichev, D. S. [Academician E.N. Meshalkin State Research Institute of Circulation Pathology, Novosibirsk (Russian Federation); Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V. [National Research Tomsk State University, Tomsk (Russian Federation); Lotkov, A. I. [Institute of Strength Physics and Materials Science of the Siberian Branch of the RAS, Tomsk (Russian Federation); Pokushalov, E. A.

    2015-11-17

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using {sup 123}I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  5. Long-term risk of fatal malignancy following pediatric radiofrequency ablation.

    Science.gov (United States)

    Clay, Mark A; Campbell, Robert M; Strieper, Margaret; Frias, Patricio A; Stevens, Mary; Mahle, William T

    2008-10-01

    Children undergoing radiofrequency ablation (RFA) are believed to be at increased risk of developing malignancy caused by radiation, although the magnitude of this risk is incompletely understood. We previously reported a strategy to reduce radiation exposure during pediatric RFA. In a cohort of 15 subjects (median age 12 years, range 9 to 17), radiation was measured using dosimeters at 5 sites. The risk of malignancy using measured radiation absorbed dose was calculated. International Council for Radiation Protection 60 risk estimates were applied to calculate absorbed organ doses. Median duration of combined biplane fluoroscopy was 14.4 minutes. Of the 5 dosimeter locations, the right scapular location had the highest median radiation exposure (43 mGy). Incorporating data from the 5 dosimeters, the risk model calculated that the organ with the greatest absorbed dose and at greatest risk of malignancy was the lung, followed by bone marrow, then breast. Thyroid and ovary exposures were negligible. The increased lifetime risk of fatal malignancy was 0.02% per single RFA procedure. In conclusion, with appropriate measures to reduce radiation exposure, the increased risk of malignancy after a single RFA procedure in children is low. These data should be of help counseling families and will contribute to analysis of the relative risk reduction benefits of such novel imaging approaches as a magnetic resonance imaging-based catheterization laboratory.

  6. Gravitational radiation from a rotating magnetic dipole

    CERN Document Server

    Hacyan, Shahen

    2016-01-01

    The gravitational radiation emitted by a rotating magnetic dipole is calculated. Formulas for the polarization amplitudes and the radiated power are obtained in closed forms, considering both the near and radiation zones of the dipole. For a neutron star, a comparison is made with other sources of gravitational and electromagnetic radiation.

  7. A Hadron Radiation Installation and Verification Method

    NARCIS (Netherlands)

    Beekman, F.J.; Bom, V.R.

    2013-01-01

    A hadron radiation installation adapted to subject a target to irradiation by a hadron radiation beam, said installation comprising: - a target support configured to support, preferably immobilize, a target: - a hadron radiation apparatus adapted to emit a hadron radiation beam along a beam axis to

  8. Radiofrequency coblation of congenital nasopharyngeal teratoma: a novel technique.

    Science.gov (United States)

    Hwang, Sang Yun; Jefferson, Niall; Mohorikar, Alok; Jacobson, Ian

    2015-01-01

    Introduction. Congenital nasopharyngeal teratomas are rare tumours that pose difficulties in diagnosis and surgical management. We report the first use of radiofrequency coblation in the management of such tumours. Case Report. A premature baby with a perinatal diagnosis of a large, obstructing nasooropharyngeal mass was referred to the ENT service for further investigations and management. The initial biopsy was suggestive of a neuroblastoma, but the tumour demonstrated rapid growth despite appropriate chemotherapy. In a novel use of radiofrequency coblation, the nasooropharyngeal mass was completely excised, with the final histopathology revealing a congenital nasopharyngeal teratoma. Conclusion. We report the first use of radiofrequency coblation to excise a congenital nasopharyngeal teratoma and discuss its advantages.

  9. Studies of radiation fields of LCLS-II super conducting radio frequency cavities

    Science.gov (United States)

    Santana Leitner, M.; Ge, L.; Li, Z.; Xu, C.; Adolphsen, C.; Ross, M.; Carrasco, M.

    2016-09-01

    The Linac Coherent Light Source II (LCLS-II) will be a hard X-ray Free Electron Laser whose linac can deliver a 1.2 MW CW electron beam with bunch rates up to 1 MHz. To efficiently generate such a high power beam, Super-Conducting Radio-Frequency (SCRF) cavities will be installed in the upstream portion of the existing 3 km Linac at the SLAC National Accelerator Laboratory. The 9-cell niobium cavities will be cooled at 2K inside 35 cryomodules, each containing a string of eight of those cavities followed by a quadrupole. The strong electromagnetic fields in the SCRF cavities will extract electrons from the cavity walls that may be accelerated. Most such dark current will be deposited locally, although some electrons may reach several neighboring cryomodules, gaining substantial energy before they hit a collimator or other aperture. The power deposited by the field emitted electrons and the associated showers may pose radiation and machine protection issues at the cryomodules and also in other areas of the accelerator. Simulation of these effects is therefore crucial for the design of the machine. The in-house code Track3P was used to simulate field emitted electrons from the LCLS-II cavities, and a sophisticated 3D model of the cryomodules including all cavities was written to transport radiation with the Fluka Monte Carlo code, which was linked to Track3P through custom-made routines. This setup was used to compute power deposition in components, prompt and residual radiation fields, and radioisotope inventories.

  10. 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.

  11. Polarisation analysis of VUV synchrotron radiation emitted from a bending magnet source in the energy range 20-50 eV: A comparison between measurements and theoretical predictions

    Energy Technology Data Exchange (ETDEWEB)

    Finetti, P.; Holland, D.M.P. E-mail: d.m.p.holland@dl.ac.uk; Latimer, C.J.; Binns, C

    2004-02-01

    The results of a study to characterise the polarisation properties of the photon beam emerging from beamline 5D, mounted on a bending magnet source at the Synchrotron Radiation Source, Daresbury Laboratory, are presented. The expectation values for the Stokes parameters corresponding to the light transmitted by the beamline have been calculated by combining ray-tracing and optical methods. The polarisation of the light at the source is modified both by the beamline geometry and by the reflections at the optical components. Although it is often assumed that the polarising properties of grazing incidence optics are negligible, this assumption leads to rather inaccurate results in the VUV region. A study of the reflectivity shows that even at incidence angles ({theta}{sub i}=80-85 deg.) which are far from the Brewster angle ({theta}{sub B}{approx}45 deg. for VUV and soft X-ray radiation) the residual changes in the amplitudes of the reflected light can result in non-negligible polarisation effects. Furthermore, reflection at grazing incidence gives rise to a substantial change in the phase, and this has the effect of rotating the elliptically polarised state. Theoretical Stokes parameters have been compared with full polarisation measurements obtained using a reflection polarimeter in the energy range 20-40 eV.

  12. ORGANIC LIGHT EMITTING DIODE (OLED

    Directory of Open Access Journals (Sweden)

    Aririguzo Marvis Ijeaku

    2015-09-01

    Full Text Available An Organic Light Emitting Diode (OLED is a device composed of an organic layer that emits lights in response to an electrical current. Organic light emitting diodes have advanced tremendously over the past decades. The different manufacturing processes of the OLED itself to several advantages over flat panel displays made with LCD technology which includes its light weight and flexible plastic substrates, wider viewing angles, improved brightness, better power efficiency and quicker response time. However, its drawbacks include shorter life span, poor color balance, poor outdoor performance, susceptibility to water damage etc.The application of OLEDs in electronics is on the increase on daily basics from cameras to cell phones to OLED televisions, etc. Although OLEDs provides prospects for thinner, smarter, lighter and ultraflexible electronics displays, however, due to high cost of manufacturing, it is not yet widely used.

  13. Multiparametric imaging with heterogeneous radiofrequency fields

    Science.gov (United States)

    Cloos, Martijn A.; Knoll, Florian; Zhao, Tiejun; Block, Kai T.; Bruno, Mary; Wiggins, Graham C.; Sodickson, Daniel K.

    2016-08-01

    Magnetic resonance imaging (MRI) has become an unrivalled medical diagnostic technique able to map tissue anatomy and physiology non-invasively. MRI measurements are meticulously engineered to control experimental conditions across the sample. However, residual radiofrequency (RF) field inhomogeneities are often unavoidable, leading to artefacts that degrade the diagnostic and scientific value of the images. Here we show that, paradoxically, these artefacts can be eliminated by deliberately interweaving freely varying heterogeneous RF fields into a magnetic resonance fingerprinting data-acquisition process. Observations made based on simulations are experimentally confirmed at 7 Tesla (T), and the clinical implications of this new paradigm are illustrated with in vivo measurements near an orthopaedic implant at 3T. These results show that it is possible to perform quantitative multiparametric imaging with heterogeneous RF fields, and to liberate MRI from the traditional struggle for control over the RF field uniformity.

  14. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.

    2015-01-01

    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  15. LAPAROSCOPIC NEPHRECTOMY USING RADIOFREQUENCY THERMAL ABLATION

    Directory of Open Access Journals (Sweden)

    B. Ya. Alekseev

    2012-01-01

    Full Text Available The wide use of current diagnostic techniques, such as ultrasound study, computed tomography, and magnetic resonance imaging, has led to significantly increased detection rates for disease in its early stages. This gave rise to a change in the standards for the treatment of locally advanced renal cell carcinoma (RCC. Laparoscopic nephrectomy (LN has recently become the standard treatment of locally advanced RCC in the clinics having much experience with laparoscopic surgery. The chief drawback of LN is difficulties in maintaining intraoperative hemostasis and a need for creating renal tissue ischemia. The paper gives the intermediate results of application of the new procedure of LN using radiofrequency thermal ablation in patients with non-ischemic early-stage RCC.

  16. Modes of oscillation in radiofrequency Paul traps

    DEFF Research Database (Denmark)

    Landa, H.; Reznik, B.; Drewsen, M.;

    2012-01-01

    We examine the time-dependent dynamics of ion crystals in radiofrequency traps. The problem of stable trapping of general threedimensional crystals is considered and the validity of the pseudopotential approximation is discussed. We analytically derive the micromotion amplitude of the ions......, rigorously proving well-known experimental observations. We use a recently proposed method to find the modes that diagonalize the linearized time-dependent dynamical problem. This allows one to obtain explicitly the ('Floquet-Lyapunov') transformation to coordinates of decoupled linear oscillators. We...... demonstrate the utility of the method by analyzing the modes of a small 'peculiar' crystal in a linear Paul trap. The calculations can be readily generalized to multispecies ion crystals in general multipole traps, and time-dependent quantum wavefunctions of ion oscillations in such traps can be obtained....

  17. Radiofrequency interstitial tumor ablation: dry electrode.

    Science.gov (United States)

    Johnson, D Brooke; Cadeddu, Jeffrey A

    2003-10-01

    With the shift in the treatment of small renal tumors from radical extirpative surgery to nephron-sparing approaches, dry-electrode radiofrequency ablation (RFA) has emerged as one potential modality. This application of RF energy leads to the production of heat within the treatment zone secondary to the native impedance of living tissue. Animal studies and human clinical series have demonstrated that RFA can create controlled, targeted, reproducible, and lethal lesions. Most clinical series have reported promising results, although some authors question the totality of tumor destruction by RFA. With time, the efficacy of RFA, as measured by patient survival, will be determined. Once this is known, RFA may be compared with other therapeutic modalities for small renal tumors to determine its place.

  18. Radiofrequency ablation of a misdiagnosed Brodie's abscess.

    Science.gov (United States)

    Chan, Rs; Abdullah, Bjj; Aik, S; Tok, Ch

    2011-04-01

    Radiofrequency ablation (RFA) therapy is recognised as a safe and effective treatment option for osteoid osteoma. This case report describes a 27-year-old man who underwent computed tomography (CT)-guided percutaneous RFA for a femoral osteoid osteoma, which was diagnosed based on his clinical presentation and CT findings. The patient developed worsening symptoms complicated by osteomyelitis after the procedure. His clinical progression and subsequent MRI findings had led to a revised diagnosis of a Brodie's abscess, which was further supported by the eventual resolution of his symptoms following a combination of antibiotics treatment and surgical irrigations. This case report illustrates the unusual MRI features of osteomyelitis mimicking soft tissue tumours following RFA of a misdiagnosed Brodie's abscess and highlights the importance of a confirmatory histopathological diagnosis for an osteoid osteoma prior to treatment.

  19. Free-electron laser operation with a superconducting radio-frequency photoinjector at ELBE

    Energy Technology Data Exchange (ETDEWEB)

    Teichert, J., E-mail: j.teichert@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Arnold, A.; Büttig, H.; Justus, M. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Kamps, T. [Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Lehnert, U. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Lu, P. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Technische Universität Dresden, 01062 Dresden (Germany); Michel, P.; Murcek, P. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Rudolph, J. [Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Schurig, R.; Seidel, W. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Vennekate, H. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Technische Universität Dresden, 01062 Dresden (Germany); Will, I. [Max-Born-Institut, Berlin, Max-Born-Str. 2a, 12489 Berlin (Germany); Xiang, R. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany)

    2014-04-11

    At the radiation source ELBE a superconducting radio-frequency photoinjector (SRF gun) was developed and put into operation. Since 2010 the gun has delivered beam into the ELBE linac. A new driver laser with 13 MHz pulse repetition rate allows now to operate the free-electron lasers (FELs) with the SRF gun. This paper reports on the first lasing experiment with the far-infrared FEL at ELBE, describes the hardware, the electron beam parameters and the measurement of the FEL infrared radiation output. - Highlights: • The superconducting RF gun produces beam with Cs{sub 2}Te photocathodes. • The SRF gun operates as an injector for the ELBE linear accelerator. • First lasing of an infrared free-electron laser with an SRF gun.

  20. 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.)

  1. SYNCHROTRON RADIATION SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    HULBERT,S.L.; WILLIAMS,G.P.

    1998-07-01

    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.

  2. Process for selected gas oxide removal by radiofrequency catalysts

    Science.gov (United States)

    Cha, Chang Y.

    1993-01-01

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

  3. Percutaneous radiofrequency thermocoagulation of osteoid osteomas: factors affecting therapeutic outcome

    Energy Technology Data Exchange (ETDEWEB)

    Cribb, G.L.; Goude, W.H.; Cool, P.; Tins, B.; Cassar-Pullicino, V.N.; Mangham, D.C. [Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry (United Kingdom)

    2005-11-01

    To examine factors which affect local recurrence of osteoid osteomas treated with percutaneous CT-guided radiofrequency thermocoagulation. A prospective study was carried out on 45 patients with osteoid osteoma who underwent percutaneous radiofrequency thermocoagulation with a minimum follow-up of 12 months There were seven local recurrences (16%); all occurred within the first year. Local recurrence was significantly related to a non-diaphyseal location (P<0.01). There was no significant relationship (P=0.05) between local recurrence and age of the patient, duration of symptoms, previous treatment, size of the lesion, positive biopsy, radiofrequency generator used or the number of needle positions. There were no complications. Osteoid osteomas in a non-diaphyseal location are statistically more likely to recur than those in a diaphyseal location when treated with CT-guided percutaneous radiofrequency thermocoagulation. This relationship between local recurrence and location has not been previously reported. (orig.)

  4. Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation.

    OpenAIRE

    Chun, KR; Bestehorn, K; Pocock, SJ; FIRE AND ICE Investigators; , COLLABORATORS; Kuck, KH; Metzner, A; Ouyang, F; Chun, J; Fürnkranz, A; Elvan, A.; Arentz, T.; Kühne, M.; Sticherling, C; Gellér, L

    2016-01-01

    BACKGROUND: Current guidelines recommend pulmonary-vein isolation by means of catheter ablation as treatment for drug-refractory paroxysmal atrial fibrillation. Radiofrequency ablation is the most common method, and cryoballoon ablation is the second most frequently used technology. METHODS: We conducted a multicenter, randomized trial to determine whether cryoballoon ablation was noninferior to radiofrequency ablation in symptomatic patients with drug-refractory paroxysmal atrial fibrillatio...

  5. A case of splenic abscess after radiofrequency ablation

    Institute of Scientific and Technical Information of China (English)

    Dimitris Zacharoulis; Emmanuel Katsogridakis; Constantinos Hatzitheofilou

    2006-01-01

    Radiofrequency ablation (RFA) is an innovative technique used primarily for the palliative treatment of unresectable liver tumors. Its therapeutic indications however, have been expanded and now include various other organs and diseases. There is a paucity of data regarding technical details and complications of the use of RFA in the spleen. We report a case of partial splenectomy using radiofrequency ablation for splenic hydatid disease,complicated by an abscess formation.

  6. Surface-emitting laser logic

    Energy Technology Data Exchange (ETDEWEB)

    Olbright, G.R.; Bryan, R.P.; Brennan, T.M.; Lear, K.; Poirier, G.E.; Fu, W.S. (Sandia National Labs., Albuquerque, NM (USA)); Jewell, J.L.; Lee, Y.H. (AT and T Bell Labs., Holmdel, NJ (USA))

    1990-10-31

    We describe a new class of optical logic devices which consist of integrated phototransistors and surface-emitting lasers. The devices function as optical neurons having high gain and, as arrays, are ideal for neural networks, parallel optical signal processing and optical computing applications. 3 refs., 3 figs.

  7. In Vitro Effect of Cell Phone Radiation on Motility, DNA Fragmentation and Clusterin Gene Expression in Human Sperm

    Directory of Open Access Journals (Sweden)

    Adel Zalata

    2015-04-01

    Full Text Available Background: Use of cellular phones emitting radiofrequency electromagnetic field (RF-EMF has been increased exponentially and become a part of everyday life. This study aimed to investigate the effects of in vitro RF-EMF exposure emitted from cellular phones on sperm motility index, sperm DNA fragmentation and seminal clusterin (CLU gene expression. Materials and Methods: In this prospective study, a total of 124 semen samples were grouped into the following main categories: i. normozoospermia (N, n=26, ii. asthenozoospermia (A, n=32, iii. asthenoteratozoospermia (AT, n=31 and iv. oligoasthenoteratozoospermia (OAT, n=35. The same semen samples were then divided into two portions non-exposed and exposed samples to cell phone radiation for 1 hour. Before and immediately after exposure, both aliquots were subjected to different assessments for sperm motility, acrosin activity, sperm DNA fragmentation and CLU gene expression. Statistical differences were analyzed using paired t student test for comparisons between two sub-groups where pAT>A>N groups, respectively (p<0.05. Conclusion: Cell phone emissions have a negative impact on exposed sperm motility index, sperm acrosin activity, sperm DNA fragmentation and seminal CLU gene expression, especially in OAT cases.

  8. Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation.

    Science.gov (United States)

    Nittby, Henrietta; Grafström, Gustav; Tian, Dong Ping; Malmgren, Lars; Brun, Arne; Persson, Bertil R R; Salford, Leif G; Eberhardt, Jacob

    2008-04-01

    Considering the frequent use of mobile phones, we have directed attention to possible implications on cognitive functions. In this study we investigated in a rat model the long-term effects of protracted exposure to Global System for Mobile Communication-900 MHz (GSM-900) radiation. Out of a total of 56 rats, 32 were exposed for 2 h each week for 55 weeks to radio-frequency electromagnetic radiation at different SAR levels (0.6 and 60 mW/kg at the initiation of the experimental period) emitted by a (GSM-900) test phone. Sixteen animals were sham exposed and eight animals were cage controls, which never left the animal house. After this protracted exposure, GSM-900 exposed rats were compared to sham exposed controls. Effects on exploratory behaviour were evaluated in the open-field test, in which no difference was seen. Effects on cognitive functions were evaluated in the episodic-like memory test. In our study, GSM exposed rats had impaired memory for objects and their temporal order of presentation, compared to sham exposed controls (P = 0.02). Detecting the place in which an object was presented was not affected by GSM exposure. Our results suggest significantly reduced memory functions in rats after GSM microwave exposure (P = 0.02).

  9. Enhancement of FEM radiation by prebunching of the e-beam (stimulated super-radiance)

    CERN Document Server

    Arbel, M; Kleinman, H; Yakover, I M; Abramovich, A; Pinhasi, Y; Luria, Y; Tecimer, M; Gover, A

    2001-01-01

    An electron beam (e-beam) prebunched at the synchronous FEM frequency and traversing through a waveguide, located coaxially with a magnetic undulator, emits coherent radiation at the bunching frequency. Introduction of both a premodulated e-beam and a radio-frequency (r.f.) signal at the same frequency at the input of the waveguide can lead to more efficient interaction, and thus more power can be extracted from the electron beam. In order to achieve this, the density modulation of the electron beam should be at an appropriate phase with respect to the r.f. signal. We report a first experimental demonstration of the influence of the phase difference between the r.f. input signal and the fundamental component of the density modulation of the e-beam on the radiated power in a Free-Electron Maser (FEM). Our experimental system allows control of the current density modulation, of the r.f. input power level, in the undulator region and of the phase between that r.f. input and the modulation of the e-beam. A compar...

  10. 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

  11. Investigations on bipolar radio-frequency current application for interstitial thermotherapy (RF-ITT)

    Science.gov (United States)

    Desinger, Kai; Mueller, Gerhard J.; Stein, Thomas; Tschepe, Johannes

    1996-01-01

    This paper discusses the feasibility of radio-frequency current in bipolar technique for interstitial thermotherapy (rf-ITT). A short survey of established methods for interstitial tissue coagulation, e.g. the interstitial laser photocoagulation (ILP) and microwave exposure are given. In addition, a new concept for interstitial application of bipolar or quasi-bipolar radio- frequency alternating current is presented. Theoretical investigations of the electrical field distribution generated by a dipole model come together in the different mechanisms of heat generation by using radio-frequency alternating current. New concepts of bipolar or quasi- bipolar coaxial layered applicators are presented. This bipolar needle electrode enables the surgeon to use a partial and homogeneous exposure of radio-frequency current for interstitial thermotherapy, e.g. for the treatment of BPH or for concha coagulation in ENT. Less power is needed due to the limited current exposition at the immediate operation site and a highly safe procedure is possible. Therefore, to determine the thermal damage of tissue, depending on the rf parameters, a computer model for a real-time simulation of the spatial electrical field distribution especially for a multiple probe application is currently being developed. This is an appropriate tool for dosimetry. A similar program for LITT, called LITCIT, developed at the Laser-Medizin-Zentrum Berlin has already shown its efficiency in clinical use. Furthermore the feasibility of a 'cross-over' applicator is discussed which combines ILP and rf-application by using metallized optical fibers for a simultaneous application of electrical energy and laser radiation.

  12. 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.)

  13. Noninvasive radiofrequency treatment effect on mitochondria in pancreatic cancer cells.

    Science.gov (United States)

    Curley, Steven A; Palalon, Flavio; Lu, Xiaolin; Koshkina, Nadezhda V

    2014-11-01

    The development of novel therapeutic approaches for cancer therapy is important, especially for tumors that have poor response or develop resistance to standard chemotherapy and radiation. We discovered that noninvasive radiofrequency (RF) fields can affect cancer cells but not normal cells, inhibit progression of tumors in mice, and enhance the anticancer effects of chemotherapy. However, it remains unclear what physiological and molecular mechanisms this treatment induces inside cells. Here, we studied the effect of RF treatment on mitochondria in human pancreatic cancer cells. The morphology of mitochondria in cells was studied via electron microscopy. The alteration of mitochondrial membrane potential (Δψ) was accessed using a Mitotracker probe. The respiratory activity of mitochondria was evaluated by analyzing changes in oxygen consumption rates determined with a Mito Stress Test Kit. The production of intracellular reactive oxygen species was performed using flow cytometry. The colocalization of mitochondria and autophagosome markers in cells was performed using fluorescence immunostaining and confocal microscopy analysis. RF fields treatment changed the morphology of mitochondria in cancer cells, altered polarization of the mitochondrial membrane, substantially impaired mitochondrial respiration, and increased reactive oxygen species production, indicating RF-induced stress on the mitochondria. We also observed frequent colocalization of the autophagosome marker LC3B with the mitochondrial marker Tom20 inside cancer cells after RF exposure, indicating the presence of mitochondria in the autophagosomes. This suggests that RF-induced stress can damage mitochondria and induce elimination of damaged organelles via autophagy. RF treatment impaired the function of mitochondria in cancer cells. Therefore, mitochondria can represent one of the targets of the RF treatment. © 2014 American Cancer Society.

  14. Indirect detection of radiation sources through direct detection of radiolysis products

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C [Tracy, CA; Fischer, Larry E [Los Gatos, CA; Felter, Thomas E [Livermore, CA

    2010-04-20

    A system for indirectly detecting a radiation source by directly detecting radiolytic products. The radiation source emits radiation and the radiation produces the radiolytic products. A fluid is positioned to receive the radiation from the radiation source. When the fluid is irradiated, radiolytic products are produced. By directly detecting the radiolytic products, the radiation source is detected.

  15. VDT Emissions Radiate Debate.

    Science.gov (United States)

    Morgan, Bill

    1990-01-01

    Discusses the possible health effects of electromagnetic fields of radiation that are emitted from video display terminals (VDTs). Responses from vendors in the computer industry are related, steps to reduce possible risks are suggested, and additional sources of information on VDTs are listed. (LRW)

  16. Radiation Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is

  17. Reduction of radiofrequency exposure to the operator during short-wave diathermy treatments.

    Science.gov (United States)

    Skotte, J

    1986-01-01

    Radiofrequency electromagnetic fields near short-wave diathermy equipment operating at a frequency of 27.12 MHz can expose the physical therapist to levels above those recommended in standards for radiofrequency exposure in Western countries. Electric and magnetic fields around air-gap, diplode, monode and circuplode applicators were mapped by the author. Large differences in stray field intensities were found for the various applicators. The air-gap electrodes caused the highest levels of unwanted radiation, and the circuplode caused the lowest levels. The use of the circuplode would normally ensure an operator exposure far below the levels in recommended standards. In order to reduce the exposure during the first few minutes of a treatment, when air-gap electrodes or diplode are used, the operator should stand at the end of the diathermy console opposite to the applicator and cables and not, as is often the case, at one side. It is recommended that manufacturers change the design of the diathermy console (a minor modification) in order to ensure this operating position.

  18. Why only some plants emit isoprene.

    Science.gov (United States)

    Monson, Russell K; Jones, Ryan T; Rosenstiel, Todd N; Schnitzler, Jörg-Peter

    2013-03-01

    Isoprene (2-methyl-1,3-butadiene) is emitted from many plants and it appears to have an adaptive role in protecting leaves from abiotic stress. However, only some species emit isoprene. Isoprene emission has appeared and been lost many times independently during the evolution of plants. As an example, our phylogenetic analysis shows that isoprene emission is likely ancestral within the family Fabaceae (= Leguminosae), but that it has been lost at least 16 times and secondarily gained at least 10 times through independent evolutionary events. Within the division Pteridophyta (ferns), we conservatively estimate that isoprene emissions have been gained five times and lost two times through independent evolutionary events. Within the genus Quercus (oaks), isoprene emissions have been lost from one clade, but replaced by a novel type of light-dependent monoterpene emissions that uses the same metabolic pathways and substrates as isoprene emissions. This novel type of monoterpene emissions has appeared at least twice independently within Quercus, and has been lost from 9% of the individuals within a single population of Quercus suber. Gain and loss of gene function for isoprene synthase is possible through relatively few mutations. Thus, this trait appears frequently in lineages; but, once it appears, the time available for evolutionary radiation into environments that select for the trait is short relative to the time required for mutations capable of producing a non-functional isoprene synthase gene. The high frequency of gains and losses of the trait and its heterogeneous taxonomic distribution in plants may be explained by the relatively few mutations necessary to produce or lose the isoprene synthase gene combined with the assumption that isoprene emission is advantageous in a narrow range of environments and phenotypes.

  19. Near-field radiofrequency electromagnetic exposure assessment.

    Science.gov (United States)

    Rubtsova, Nina; Perov, Sergey; Belaya, Olga; Kuster, Niels; Balzano, Quirino

    2015-09-01

    Personal wireless telecommunication devices, such as radiofrequency (RF) electromagnetic field (EMF) sources operated in vicinity of human body, have possible adverse health effects. Therefore, the correct EMF assessment is necessary in their near field. According to international near-field measurement criteria, the specific absorption rate (SAR) is used for absorbed energy distribution assessment in tissue simulating liquid phantoms. The aim of this investigation is to validate the relationship between the H-field of incident EMF and absorbed energy in phantoms. Three typical wireless telecommunication system frequencies are considered (900, 1800 and 2450 MHz). The EMF source at each frequency is an appropriate half-wave dipole antenna and the absorbing medium is a flat phantom filled with the suitable tissue simulating liquid. Two methods for SAR estimation have been used: standard procedure based on E-field measured in tissue simulating medium and a proposed evaluation by measuring the incident H-field. Compared SAR estimations were performed for various distances between sources and phantom. Also, these research data were compared with simulation results, obtained by using finite-difference time-domain method. The acquired data help to determine the source near-field space characterized by the smallest deviation between SAR estimation methods. So, this region near the RF source is suitable for correct RF energy absorption assessment using the magnetic component of the RF fields.

  20. Radiofrequency treatment alters cancer cell phenotype

    Science.gov (United States)

    Ware, Matthew J.; Tinger, Sophia; Colbert, Kevin L.; Corr, Stuart J.; Rees, Paul; Koshkina, Nadezhda; Curley, Steven; Summers, H. D.; Godin, Biana

    2015-07-01

    The importance of evaluating physical cues in cancer research is gradually being realized. Assessment of cancer cell physical appearance, or phenotype, may provide information on changes in cellular behavior, including migratory or communicative changes. These characteristics are intrinsically different between malignant and non-malignant cells and change in response to therapy or in the progression of the disease. Here, we report that pancreatic cancer cell phenotype was altered in response to a physical method for cancer therapy, a non-invasive radiofrequency (RF) treatment, which is currently being developed for human trials. We provide a battery of tests to explore these phenotype characteristics. Our data show that cell topography, morphology, motility, adhesion and division change as a result of the treatment. These may have consequences for tissue architecture, for diffusion of anti-cancer therapeutics and cancer cell susceptibility within the tumor. Clear phenotypical differences were observed between cancerous and normal cells in both their untreated states and in their response to RF therapy. We also report, for the first time, a transfer of microsized particles through tunneling nanotubes, which were produced by cancer cells in response to RF therapy. Additionally, we provide evidence that various sub-populations of cancer cells heterogeneously respond to RF treatment.

  1. Radiofrequency ablation of idiopathic ventricular tachycardia

    Energy Technology Data Exchange (ETDEWEB)

    Vohra, J.; Shah, A.; Hua, W.; Gerloff, J.; Riters, A. [Royal Melbourne Hospital, Melbourne, VIC (Australia)

    1996-04-01

    Radiofrequency ablation (RFA) has been shown to be very effective in the treatment of supraventricular tachycardias and has replaced surgical ablation. Only a few reports of RFA for idiopathic ventricular tachycardia (VT) have appeared in the literature during the last two years. This paper presents our experience with RFA for idiopathic VT in 19 patients. In all patients the diagnostic study and therapeutic RFA were combined in a single procedure. Pacemapping were used to guide the site of RFA in patients with VT arising from the RV. Local activation time (LAT), Purkinje potentials (PP) and pacemapping were used to guide RFA in those patients with LV septal tachycardias. Idiopathic VT frequently arises from the RVOT and inferobasal portion of the LV septum. These tachycardias can be diagnosed on clinical and ECG grounds. RFA for idiopathic VT arising from these areas has a high success rate and this mode of treatment should be considered as a nonpharmacological curative treatment for symptomatic patients. 13 refs., 3 tabs., 4 figs.

  2. Epidemiology of health effects of radiofrequency exposure.

    Science.gov (United States)

    Ahlbom, Anders; Green, Adele; Kheifets, Leeka; Savitz, David; Swerdlow, Anthony

    2004-12-01

    We have undertaken a comprehensive review of epidemiologic studies about the effects of radiofrequency fields (RFs) on human health in order to summarize the current state of knowledge, explain the methodologic issues that are involved, and aid in the planning of future studies. There have been a large number of occupational studies over several decades, particularly on cancer, cardiovascular disease, adverse reproductive outcome, and cataract, in relation to RF exposure. More recently, there have been studies of residential exposure, mainly from radio and television transmitters, and especially focusing on leukemia. There have also been studies of mobile telephone users, particularly on brain tumors and less often on other cancers and on symptoms. Results of these studies to date give no consistent or convincing evidence of a causal relation between RF exposure and any adverse health effect. On the other hand, the studies have too many deficiencies to rule out an association. A key concern across all studies is the quality of assessment of RF exposure. Despite the ubiquity of new technologies using RFs, little is known about population exposure from RF sources and even less about the relative importance of different sources. Other cautions are that mobile phone studies to date have been able to address only relatively short lag periods, that almost no data are available on the consequences of childhood exposure, and that published data largely concentrate on a small number of outcomes, especially brain tumor and leukemia.

  3. Evaluation of radiofrequency dielectric heaters workers exposure.

    Science.gov (United States)

    Benes, M; Del Frate, S; Villalta, R

    2008-01-01

    Radiofrequency dielectric heaters (RFDH) are widely used in the woodworking industry for gluing laminates by applying pressure and RF heating. The workers operating such equipment remain in the vicinity of the machinery all day and can therefore be exposed to considerable levels of electric and magnetic field at RFs. This work describes the method used to measure the strength of fields generated by this particular machinery. This procedure is based on current methods cited in the literature and introduces the necessary modifications to meet this specific case. In particular, as there is often a scarcity of technical data available relating to such heaters, it is suggested that a spectrum analyser be used for measurements in the frequencies domain. On the basis of the data obtained the norms of reference are established, the instrumentation to be used in successive stages determined as well as the identification of possible sources of interference from spurious signals. Furthermore, a mapping of the field strengths is presented and the means of determining the decay curve as a function of distance. This last type of measurement is done to estimate the effectiveness of grounding the machinery. The report ends with an estimate of the exposure of workers to electromagnetic fields and also some recommendations for reducing risk.

  4. Radio Frequency Radiation of Millimeter Wave Length: An Evaluation of Potential Occupational Safety Issues Relating to Surface Heating

    Science.gov (United States)

    2016-06-14

    Radio frequency radiation of millimeter wave length: An evaluation of potential occupational safety issues. 5a. CONTRACT NUMBER 5b. GRANT NUMBER...Paper------------------------------- RADIO FREQUENCY RADIATION OF MILLIMETER WAVE LENGTH: POTENTIAL OCCUPATIONAL...cancer. Health Phys. 78(2):170-181; 2000 Key words: cancer; radiation , nonionizing; occupational safety; radiofrequency INTRODUCTION THE RADIO

  5. Radiofrequency catheter ablation maintains its efficacy better than antiarrhythmic medication in patients with paroxysmal atrial fibrillation

    DEFF Research Database (Denmark)

    Raatikainen, M J Pekka; Hakalahti, Antti; Uusimaa, Paavo;

    2015-01-01

    BACKGROUND: The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) is a randomized trial comparing radiofrequency catheter ablation (RFA) to antiarrhythmic drugs (AADs) as first-line treatment of paroxysmal atrial fibrillation (PAF). In order...

  6. Effects of RF fields emitted from smart phones on cardio-respiratory parameters: a preliminary provocation study.

    Science.gov (United States)

    Kwon, Min Kyung; Nam, Ki Chang; Lee, Da Som; Jang, Kyung Hwan; Kim, Deok Won

    2011-01-01

    This paper describes an experimental setup for evaluating the physiological effects of radiofrequency (RF) emitted from a Wideband Code Division Multiple Access (WCDMA) module with a 24 dBm at 1950 MHz for specific absorption rate (SAR(1g)) of 1.57 W/kg. This provocation study was executed in a double-blind study of two volunteer groups of 10 self-reported electromagnetic hypersensitivity (EHS) and 10 non-EHS subjects under both sham and real exposures in a randomly assigned and counter-balanced order. In the preliminary results, WCDMA RF exposure of 30 min did not have any effects on physiological changes in either group.

  7. Room-temperature fabrication of light-emitting thin films based on amorphous oxide semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junghwan, E-mail: JH.KIM@lucid.msl.titech.ac.jp; Miyokawa, Norihiko; Ide, Keisuke [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Toda, Yoshitake [Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox SE-6, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Hiramatsu, Hidenori; Hosono, Hideo; Kamiya, Toshio [Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox SE-6, 4259 Nagatsuta, Midori-ku, Yokohama (Japan)

    2016-01-15

    We propose a light-emitting thin film using an amorphous oxide semiconductor (AOS) because AOS has low defect density even fabricated at room temperature. Eu-doped amorphous In-Ga-Zn-O thin films fabricated at room temperature emitted intense red emission at 614 nm. It is achieved by precise control of oxygen pressure so as to suppress oxygen-deficiency/excess-related defects and free carriers. An electronic structure model is proposed, suggesting that non-radiative process is enhanced mainly by defects near the excited states. AOS would be a promising host for a thin film phosphor applicable to flexible displays as well as to light-emitting transistors.

  8. A Rare Complication of Radiofrequency Tonsil Ablation: Horner Syndrome

    Directory of Open Access Journals (Sweden)

    Cuneyt Kucur

    2015-01-01

    Full Text Available Chronic tonsillitis is a common disease, and several different surgical techniques are used to treat this condition. In recent years, techniques such as radiofrequency ablation and coblation have been commonly used for tonsil surgery. In this report, we present the cases of two pediatric patients who developed ptosis, miosis, and enophthalmos (Horner syndrome after radiofrequency ablation for tonsil reduction and discuss the technique of radiofrequency ablation of the tonsils. In the early postoperative period, miosis and ptosis were observed on the right side in one patient and on the left side in the other patient. Both patients were treated with 1 mg/kg/day methylprednisolone, which were tapered by halving the dose every 3 days. Miosis and ptosis improved after treatment in both patients. Along with the case presentation, we discuss the effectiveness and complications of radiofrequency ablation of the tonsils. These unusual complications of tonsil ablation may help ENT physicians who do not yet have a preferred surgical technique for tonsillectomy to make an informed decision. Limited data are available about the possible complications of radiofrequency ablation of the tonsils. The present report contributes to the literature on this topic.

  9. 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.

  10. A Rare Complication of Radiofrequency Tonsil Ablation: Horner Syndrome.

    Science.gov (United States)

    Kucur, Cuneyt; Ozbay, Isa; Oghan, Fatih; Yildirim, Nadir; Zeybek Sivas, Zuhal; Canbaz Kabay, Sibel

    2015-01-01

    Chronic tonsillitis is a common disease, and several different surgical techniques are used to treat this condition. In recent years, techniques such as radiofrequency ablation and coblation have been commonly used for tonsil surgery. In this report, we present the cases of two pediatric patients who developed ptosis, miosis, and enophthalmos (Horner syndrome) after radiofrequency ablation for tonsil reduction and discuss the technique of radiofrequency ablation of the tonsils. In the early postoperative period, miosis and ptosis were observed on the right side in one patient and on the left side in the other patient. Both patients were treated with 1 mg/kg/day methylprednisolone, which were tapered by halving the dose every 3 days. Miosis and ptosis improved after treatment in both patients. Along with the case presentation, we discuss the effectiveness and complications of radiofrequency ablation of the tonsils. These unusual complications of tonsil ablation may help ENT physicians who do not yet have a preferred surgical technique for tonsillectomy to make an informed decision. Limited data are available about the possible complications of radiofrequency ablation of the tonsils. The present report contributes to the literature on this topic.

  11. A Rare Complication of Radiofrequency Tonsil Ablation: Horner Syndrome

    Science.gov (United States)

    Ozbay, Isa; Yildirim, Nadir; Zeybek Sivas, Zuhal; Canbaz Kabay, Sibel

    2015-01-01

    Chronic tonsillitis is a common disease, and several different surgical techniques are used to treat this condition. In recent years, techniques such as radiofrequency ablation and coblation have been commonly used for tonsil surgery. In this report, we present the cases of two pediatric patients who developed ptosis, miosis, and enophthalmos (Horner syndrome) after radiofrequency ablation for tonsil reduction and discuss the technique of radiofrequency ablation of the tonsils. In the early postoperative period, miosis and ptosis were observed on the right side in one patient and on the left side in the other patient. Both patients were treated with 1 mg/kg/day methylprednisolone, which were tapered by halving the dose every 3 days. Miosis and ptosis improved after treatment in both patients. Along with the case presentation, we discuss the effectiveness and complications of radiofrequency ablation of the tonsils. These unusual complications of tonsil ablation may help ENT physicians who do not yet have a preferred surgical technique for tonsillectomy to make an informed decision. Limited data are available about the possible complications of radiofrequency ablation of the tonsils. The present report contributes to the literature on this topic. PMID:26064747

  12. Magnetoreception in birds: the effect of radio-frequency fields.

    Science.gov (United States)

    Wiltschko, Roswitha; Thalau, Peter; Gehring, Dennis; Nießner, Christine; Ritz, Thorsten; Wiltschko, Wolfgang

    2015-02-01

    The avian magnetic compass, probably based on radical pair processes, works only in a narrow functional window around the local field strength, with cryptochrome 1a as most likely receptor molecule. Radio-frequency fields in the MHz range have been shown to disrupt the birds' orientation, yet the nature of this interference is still unclear. In an immuno-histological study, we tested whether the radio-frequency fields interfere with the photoreduction of cryptochrome, but this does not seem to be the case. In behavioural studies, birds were not able to adjust to radio-frequency fields like they are able to adjust to static fields outside the normal functional range: neither a 2-h pre-exposure in a 7.0 MHz field, 480 nT, nor a 7-h pre-exposure in a 1.315 MHz field, 15 nT, allowed the birds to regain their orientation ability. This inability to adjust to radio-frequency fields suggests that these fields interfere directly with the primary processes of magnetoreception and therefore disable the avian compass as long as they are present. They do not have lasting adverse after-effects, however, as birds immediately after exposure to a radio-frequency field were able to orient in the local geomagnetic field.

  13. Successful treatment of hepatic oligometastases with stereotactic ablative radiotherapy and radiofrequency ablation in an anaplastic lymphoma kinase fusion-positive lung cancer patient

    DEFF Research Database (Denmark)

    Weber, Britta; Liu, Mitchell; Sobkin, Paul

    2016-01-01

    Local ablative therapy with stereotactic ablative radiotherapy may improve survival in oncogene‐addicted lung cancer patients with extracranial oligometastatic disease treated with targeted therapies. There is limited data on the use of radiofrequency ablation (RFA) in this same setting. We present...... a case of an anaplastic lymphoma kinase (ALK)‐positive lung cancer patient with hepatic oligometastatic progression who was successfully treated with both stereotactic ablative radiation and RFA while continuing with an ALK inhibitor....

  14. MATHEMATICAL MODELS FOR SOME RADIO-FREQUENCY TRANSMISSION-LINE TRANSFORMERS

    Science.gov (United States)

    MATRICES(MATHEMATICS), *PHASE SHIFT CIRCUITS, *RADIOFREQUENCY, *TRANSFORMERS, *TRANSMISSION LINES, BROADBAND, DIELECTRIC PROPERTIES, ELECTRICAL IMPEDANCE, FERRITES, IMPEDANCE MATCHING , MATHEMATICAL ANALYSIS.

  15. 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 range

  16. 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

  17. Stimulated coherent transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Influence of radiofrequency surgery on architecture of the palatine tonsils.

    Science.gov (United States)

    Plzak, Jan; Macokova, Pavla; Zabrodsky, Michal; Kastner, Jan; Lastuvka, Petr; Astl, Jaromir

    2014-01-01

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

  19. Radiofrequency Coblation of Congenital Nasopharyngeal Teratoma: A Novel Technique

    Directory of Open Access Journals (Sweden)

    Sang Yun Hwang

    2015-01-01

    Full Text Available Introduction. Congenital nasopharyngeal teratomas are rare tumours that pose difficulties in diagnosis and surgical management. We report the first use of radiofrequency coblation in the management of such tumours. Case Report. A premature baby with a perinatal diagnosis of a large, obstructing nasooropharyngeal mass was referred to the ENT service for further investigations and management. The initial biopsy was suggestive of a neuroblastoma, but the tumour demonstrated rapid growth despite appropriate chemotherapy. In a novel use of radiofrequency coblation, the nasooropharyngeal mass was completely excised, with the final histopathology revealing a congenital nasopharyngeal teratoma. Conclusion. We report the first use of radiofrequency coblation to excise a congenital nasopharyngeal teratoma and discuss its advantages.

  20. Influence of Radiofrequency Surgery on Architecture of the Palatine Tonsils

    Directory of Open Access Journals (Sweden)

    Jan Plzak

    2014-01-01

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

  1. Cooling analysis of a light emitting diode automotive fog lamp

    Directory of Open Access Journals (Sweden)

    Zadravec Matej

    2017-01-01

    Full Text Available Efficiency of cooling fins inside of a light emitting diode fog lamp is studied using computational fluid dynamics. Diffusion in heat sink, natural convection and radiation are the main principles of the simulated heat transfer. The Navier-Stokes equations were solved by the computational fluid dynamics code, including Monte Carlo radiation model and no additional turbulence model was needed. The numerical simulation is tested using the existing lamp geometry and temperature measurements. The agreement is excellent inside of few degrees at all measured points. The main objective of the article is to determine the cooling effect of various heat sink parts. Based on performed simulations, some heat sink parts are found to be very ineffective. The geometry and heat sink modifications are proposed. While radiation influence is significant, compressible effects are found to be minor.

  2. Photoacoustic characterization of radiofrequency ablation lesions

    Science.gov (United States)

    Bouchard, Richard; Dana, Nicholas; Di Biase, Luigi; Natale, Andrea; Emelianov, Stanislav

    2012-02-01

    Radiofrequency ablation (RFA) procedures are used to destroy abnormal electrical pathways in the heart that can cause cardiac arrhythmias. Current methods relying on fluoroscopy, echocardiography and electrical conduction mapping are unable to accurately assess ablation lesion size. In an effort to better visualize RFA lesions, photoacoustic (PA) and ultrasonic (US) imaging were utilized to obtain co-registered images of ablated porcine cardiac tissue. The left ventricular free wall of fresh (i.e., never frozen) porcine hearts was harvested within 24 hours of the animals' sacrifice. A THERMOCOOLR Ablation System (Biosense Webster, Inc.) operating at 40 W for 30-60 s was used to induce lesions through the endocardial and epicardial walls of the cardiac samples. Following lesion creation, the ablated tissue samples were placed in 25 °C saline to allow for multi-wavelength PA imaging. Samples were imaged with a VevoR 2100 ultrasound system (VisualSonics, Inc.) using a modified 20-MHz array that could provide laser irradiation to the sample from a pulsed tunable laser (Newport Corp.) to allow for co-registered photoacoustic-ultrasound (PAUS) imaging. PA imaging was conducted from 750-1064 nm, with a surface fluence of approximately 15 mJ/cm2 maintained during imaging. In this preliminary study with PA imaging, the ablated region could be well visualized on the surface of the sample, with contrasts of 6-10 dB achieved at 750 nm. Although imaging penetration depth is a concern, PA imaging shows promise in being able to reliably visualize RF ablation lesions.

  3. Percutaneous radiofrequency ablation in painful bone metastases

    Directory of Open Access Journals (Sweden)

    German Garabano

    2015-09-01

    Full Text Available Backgraund There are different treatment for painful bone metastases (mtts, with different results. CT-guided Percutaneous Radiofrequency Ablation (CT-PRA is one of them. The pupose of this retrospective study was to assess the initial results using this methods, focusing on pain relief, showing details of the surgical technique. Methods 18 patients with an average age of 59.2 years and 15 months follow-up were treated. Nine mtts were located in the femur, 4 dorsal / lumbar spine, 3 in scapula and 2 in Iliac. The Mtts origin were Breast Ca 7 cases, lung in 4, Kidney in 4 and 3 in Thyroid. The rachis mtts were found at more than 10mm of the medullary cavity and mtts of long bones showed low risk of fracture. Lesions >3cm were treated whit CT-PRA  using Valleylab Rita needle and these <3cm with CoolTip needle. Pain was assessed by Visual Analog Scale (VAS preoperatively, at 2, 7 and 30 days, and then at 3 and 6 months. Results Preoperative pain score was 8.33 on average. At 7 days of ablatión de VAS score was 5 on average and at 30 days was 2 points. After at 3 and 6 months de VAS average was 1. This method had excellent patients tolerance and no complications. There were two recurrences which underwent endoprosthesis unconventional proximal femur and knee respectively, evolving favorably. Conclusion CT-guided APRF impresses a promising, simple and effective tool in the treatment of painfull bone mtts, achieving excellent pain control with good tolerance by the patient.

  4. Laparoscopic radiofrequency ablation of neuroendocrine liver metastases.

    Science.gov (United States)

    Berber, Eren; Flesher, Nora; Siperstein, Allan E

    2002-08-01

    We previously reported on the safety and efficacy of laparoscopic radiofrequency thermal ablation (RFA) for treating hepatic neuroendocrine metastases. The aim of this study is to report our 5-year RFA experience in the treatment of these challenging group of patients. Of the 222 patients with 803 liver primary and secondary tumors undergoing laparoscopic RFA between January 1996 and August 2001, a total of 34 patients with 234 tumors had neuroendocrine liver metastases. There were 25 men and 9 women with a mean +/- SEM age of 52 +/- 2 years who underwent 42 ablations. Primary tumor types included carcinoid tumor in 18 patients, medullary thyroid cancer in 7, secreting islet cell tumor in 5, and nonsecreting islet cell tumor in 4. There was no mortality, and the morbidity was 5%. The mean hospital stay was 1.1 days. Symptoms were ameliorated in 95%, with significant or complete symptom control in 80% of the patients for a mean of 10+ months (range 6-24 months). All patients were followed for a mean +/- SEM of 1.6 +/- 0.2 years (range 1.0-5.4 years). During this period new liver lesions developed in 28% of patients, new extrahepatic disease in 25%, and local liver recurrence in 13%; existing liver lesions progressed in 13%. Overall 41% of patients showed no progression of their cancer. Nine patients (27%) died. Mean +/- SEM survivals after diagnosis of primary disease, detection of liver metastases, and performance of RFA were 5.5 +/- 0.8 years, 3.0 +/- 0.3 years, and 1.6 +/- 0.2 years, respectively. Sixty-five percent of the patients demonstrated a partial or significant decrease in their tumor markers during follow-up. In conclusion, RFA provides excellent local tumor control with overnight hospitalization and low morbidity in the treatment of liver metastases from neuroendocrine tumors. It is a useful modality in the management of these challenging group of patients.

  5. Radiofrequency ablation for treatment of atrial fibrillation.

    Science.gov (United States)

    Safaei, Nasser; Montazerghaem, Hossein; Azarfarin, Rasoul; Alizadehasl, Azin; Alikhah, Hossein

    2011-01-01

    Atrial Fibrillation (AF) is the most common cardiac arrhythmia which represents a major public health problem. The main purpose of this research is to evaluate the Radiofrequency (RF) ablation effects in the patients with chronic AF scheduled for cardiac surgery because of different heart diseases. The descriptive and prospective study was conducted on 60 patients with AF scheduled for surgery along with RF ablation. The data were collected by questionnaire and included: patients' age, sex, NYHA class, operation type, past medical history, type and cause of valvular heart disease, preoperative ECG (electrocardiogram), duration of surgery, clamping time, cardiopulmonary bypass, and RF ablation time. RF ablation was followed by the main operation. The follow up examination, ECG, and echocardiography were performed 3 and 6 months after operation. The mean age of patients was 48±10 years (18-71 years). Forty one patients had permanent AF and 19 had the persistent AF. The left ventricular ejection fraction was 48.27±9.75 percent before operation, and reached to 56.27±7.87 percent after the surgery (P<0.001). The mean NYHA class before the surgery was 2.83±0.68 which decreased to 1.34±0.46 6 months after the surgery with RF ablation (P<0.001). One patient (1.6%) died after surgery. Complete relief and freedom from AF recurrence was observed in 70% of patients in the mean follow up in 7 months after the surgery. The sinus rhythm with efficient atrial contraction was established in 100% of discharged patients. RF ablation is an effective procedure to cure atrial fibrillation in patients undergoing cardiac surgeries.

  6. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation

    DEFF Research Database (Denmark)

    Walfridsson, H; Walfridsson, U; Nielsen, J Cosedis

    2015-01-01

    AIMS: The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) trial assessed the long-term efficacy of an initial strategy of radiofrequency ablation (RFA) vs. antiarrhythmic drug therapy (AAD) as first-line treatment for patients with PAF. I......L and symptom burden in patients with PAF. Patients randomized to RFA showed greater improvement in physical scales (SF-36) and the EQ-visual analogue scale. CLINICAL TRIAL REGISTRATION: URL http://www.clinicaltrials.gov. Unique identifier: NCT00133211....

  7. Differentially-Enhanced Sideband Imaging via Radio-frequency Encoding

    CERN Document Server

    Fard, A M; Jalali, B

    2015-01-01

    We present a microscope paradigm that performs differential interference imaging with high sensitivity via optical amplification and radio-frequency (RF) heterodyne detection. This method, termed differentially-enhanced sideband imaging via radio-frequency encoding (DESIRE), uniquely exploits frequency-to-space mapping technique to encode the image of an object onto the RF sidebands of an illumination beam. As a proof-of-concept, we show validation experiment by implementing radio frequency (f = 15 GHz) phase modulation in conjunction with spectrally-encoded laser scanning technique to acquire one-dimensional image of a barcode-like object using a commercial RF spectrum analyzer.

  8. 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...... a coagulative necrosis area with minimal invasion and inflammatory tissue at about 2 cm surrounding the lesion. CONCLUSION: EUS-RFA is a feasible technique and might represent a promising therapy for the future treatment of pancreatic cancer. However, further studies are necessary to investigate EUS-guided RFA...

  9. Endovenous radiofrequency ablation for the treatment of varicose veins.

    Science.gov (United States)

    Kayssi, Ahmed; Pope, Marc; Vucemilo, Ivica; Werneck, Christiane

    2015-04-01

    Varicose veins are a common condition that can be treated surgically. Available operative modalities include saphenous venous ligation and stripping, phlebectomy, endovenous laser therapy and radiofrequency ablation. Radiofrequency ablation is the newest of these technologies, and to our knowledge our group was the first to use it in Canada. Our experience suggests that it is a safe and effective treatment for varicose veins, with high levels of patient satisfaction reported at short-term follow-up. More studies are needed to assess long-term effectiveness and compare the various available treatment options for varicose veins.

  10. Bacterial meningitis after radiofrequency diathermy for adenoid hypertrophy.

    Science.gov (United States)

    Nagasaki, Azusa; Sato, Atsuo; Shiro, Hiroyuki

    2014-06-01

    A 6-year-old otherwise healthy girl who underwent radiofrequency diathermy for adenoid hypertrophy presented with fever on the same day and was diagnosed as having bacterial meningitis 2 days later. Culture of cerebrospinal fluid indicated that the pathogens were penicillin-sensitive Streptococcus pneumoniae and methicillin-sensitive Staphylococcus aureus. The serotype of the causative pneumococcus, 11A, was not covered by the 7-valent pneumococcal conjugate vaccine the patient had been inoculated with. Although not previously reported, radiofrequency diathermy for adenoid hypertrophy can be considered a risk factor for bacteremia and meningitis.

  11. Bright light-emitting diodes based on organometal halide perovskite.

    Science.gov (United States)

    Tan, Zhi-Kuang; Moghaddam, Reza Saberi; Lai, May Ling; Docampo, Pablo; Higler, Ruben; Deschler, Felix; Price, Michael; Sadhanala, Aditya; Pazos, Luis M; Credgington, Dan; Hanusch, Fabian; Bein, Thomas; Snaith, Henry J; Friend, Richard H

    2014-09-01

    Solid-state light-emitting devices based on direct-bandgap semiconductors have, over the past two decades, been utilized as energy-efficient sources of lighting. However, fabrication of these devices typically relies on expensive high-temperature and high-vacuum processes, rendering them uneconomical for use in large-area displays. Here, we report high-brightness light-emitting diodes based on solution-processed organometal halide perovskites. We demonstrate electroluminescence in the near-infrared, green and red by tuning the halide compositions in the perovskite. In our infrared device, a thin 15 nm layer of CH3NH3PbI(3-x)Cl(x) perovskite emitter is sandwiched between larger-bandgap titanium dioxide (TiO2) and poly(9,9'-dioctylfluorene) (F8) layers, effectively confining electrons and holes in the perovskite layer for radiative recombination. We report an infrared radiance of 13.2 W sr(-1) m(-2) at a current density of 363 mA cm(-2), with highest external and internal quantum efficiencies of 0.76% and 3.4%, respectively. In our green light-emitting device with an ITO/PEDOT:PSS/CH3NH3PbBr3/F8/Ca/Ag structure, we achieved a luminance of 364 cd m(-2) at a current density of 123 mA cm(-2), giving external and internal quantum efficiencies of 0.1% and 0.4%, respectively. We show, using photoluminescence studies, that radiative bimolecular recombination is dominant at higher excitation densities. Hence, the quantum efficiencies of the perovskite light-emitting diodes increase at higher current densities. This demonstration of effective perovskite electroluminescence offers scope for developing this unique class of materials into efficient and colour-tunable light emitters for low-cost display, lighting and optical communication applications.

  12. Standard guidelines for electrosurgery with radiofrequency current

    Directory of Open Access Journals (Sweden)

    Mutalik Sharad

    2009-08-01

    Full Text Available Definition: Radiofrequency (RF induces thermal destruction of the targeted tissue by an electrical current at a frequency of 0.5 MHz (RF. As the electrode tip is not heated, there is minimal thermal damage to the surrounding tissues, producing good esthetic results. Therefore, RF ablation is also known as cold ablation or "coblation." Modality: It has three modes of operation: (a Cut, (b cut and coagulate and (c coagulate. Therefore, it can be used for various purposes like incision, ablation, fulguration, shave excision and coagulation. Because of the coagulation facility, hemostasis can be achieved and operation becomes easier and faster. Indications: It is effective in treating various skin conditions like dermatosis papulosa nigra, warts, molluscum contagiosum, colloid milia, acquired junctional, compound and dermal melanocytic nevi, seborrheic keratosis, skin tags, granuloma pyogenicum, verrucous epidermal nevi, xanthelesma, rhinophyma, superficial basal cell carcinoma and telangiectasia. It can also be used for cosmetic indications such as resurfacing, earlobe repair and blepharoplasty. Anesthesia: The procedure is accomplished either under topical anesthesia eutactic mixture of local anesthetics or local injectable anesthesia, under all aseptic precautions. Procedure: While operating, only the tip of the electrode should come in contact with the tissue. Actual contact of the electrode with the tissue should be very brief in order to prevent excessive damage to the deeper tissues. This can be accomplished by moving the electrode quickly. Complications: Complications are uncommon and mainly occur due to an improper technique. The treating physician should be aware of the contraindications of the procedure as listed in these guidelines. Physician qualification: RF surgery may be performed by a dermatologist who has acquired adequate training during post-graduation or through recognized fellowships and workshops dedicated to RF surgery. He

  13. Endovascular Radiofrequency Ablation for Varicose Veins

    Science.gov (United States)

    2011-01-01

    Executive Summary Objective The objective of the MAS evidence review was to conduct a systematic review of the available evidence on the safety, effectiveness, durability and cost–effectiveness of endovascular radiofrequency ablation (RFA) for the treatment of primary symptomatic varicose veins. Background The Ontario Health Technology Advisory Committee (OHTAC) met on August 26th, 2010 to review the safety, effectiveness, durability, and cost-effectiveness of RFA for the treatment of primary symptomatic varicose veins based on an evidence-based review by the Medical Advisory Secretariat (MAS). Clinical Condition Varicose veins (VV) are tortuous, twisted, or elongated veins. This can be due to existing (inherited) valve dysfunction or decreased vein elasticity (primary venous reflux) or valve damage from prior thrombotic events (secondary venous reflux). The end result is pooling of blood in the veins, increased venous pressure and subsequent vein enlargement. As a result of high venous pressure, branch vessels balloon out leading to varicosities (varicose veins). Symptoms typically affect the lower extremities and include (but are not limited to): aching, swelling, throbbing, night cramps, restless legs, leg fatigue, itching and burning. Left untreated, venous reflux tends to be progressive, often leading to chronic venous insufficiency (CVI). A number of complications are associated with untreated venous reflux: including superficial thrombophlebitis as well as variceal rupture and haemorrhage. CVI often results in chronic skin changes referred to as stasis dermatitis. Stasis dermatitis is comprised of a spectrum of cutaneous abnormalities including edema, hyperpigmentation, eczema, lipodermatosclerosis and stasis ulceration. Ulceration represents the disease end point for severe CVI. CVI is associated with a reduced quality of life particularly in relation to pain, physical function and mobility. In severe cases, VV with ulcers, QOL has been rated to be as bad

  14. Extreme diffusion limited electropolishing of niobium radiofrequency cavities

    Science.gov (United States)

    Crawford, Anthony C.

    2017-03-01

    A deeply modulated, regular, continuous, oscillating current waveform is reliably and repeatably achieved during electropolishing of niobium single-cell elliptical radiofrequency cavities. Details of the technique and cavity test results are reported here. The method is applicable for cavity frequencies in the range 500 MHz to 3.9 GHz and can be extended to multicell structures.

  15. Longevity of radiofrequency identification device microchips in citrus trees

    Science.gov (United States)

    Long-term identification of individual plants in the field is an important part of many types of botanical and horticultural research. In a previous report, we described methods for using implanted radiofrequency (RFID) microchips to tag citrus trees for field research. This report provides an upd...

  16. Radiofrequency solutions in clinical high field magnetic resonance

    NARCIS (Netherlands)

    Andreychenko, A.|info:eu-repo/dai/nl/341697672

    2013-01-01

    Magnetic resonance imaging (MRI) and spectroscopy (MRS) benefit from the sensitivity gain at high field (≥7T). However, high field brings also certain challenges associated with growing frequency and spectral dispersion. Frequency growth results in degraded performance of large volume radiofrequency

  17. Radiofrequency ablation in the treatment of liver tumors in children

    NARCIS (Netherlands)

    van Laarhoven, Stijn; van Baren, Robertine; Tamminga, Rienk Yde Johan; de Jong, Koert Pieter

    Hepatoblastoma and liver metastasis of Wilms' tumors are rare hepatic tumors in children. Treatment of both tumors consists of a combination of chemotherapy and liver surgery. Radiofrequency ablation (RFA) is frequently used for the treatment of adult liver tumors but is rarely mentioned as a

  18. 77 FR 43535 - Grantee Codes for Certified Radiofrequency Equipment

    Science.gov (United States)

    2012-07-25

    ... radiofrequency (RF) devices under part 2 of its rules. This program is one of the primary means that the Commission uses to ensure that the multitude of RF devices used in the United States operates effectively without causing harmful interference and otherwise complies with the rules. RF devices that are subject to...

  19. Arthroscopic gluteal muscle contracture release with radiofrequency energy.

    Science.gov (United States)

    Liu, Yu-Jie; Wang, Yan; Xue, Jing; Lui, Pauline Po-Yee; Chan, Kai-Ming

    2009-03-01

    Gluteal muscle contracture is common after repeated intramuscular injections and sometimes is sufficiently debilitating to require open surgery. We asked whether arthroscopic release of gluteal muscle contracture using radiofrequency energy would decrease complications with clinically acceptable results. We retrospectively reviewed 108 patients with bilateral gluteal muscle contractures (57 males, 51 females; mean age, 23.7 years). We used inferior, anterosuperior, and posterosuperior portals. With the patient lying laterally, we developed and enlarged a potential space between the gluteal muscle group and the subcutaneous fat using blunt dissection. Under arthroscopic guidance through the inferior portal, we débrided and removed fatty tissue overlying the contractile band of the gluteal muscle group using a motorized shaver introduced through the superior portal. Radiofrequency then was introduced through the superior portal to gradually excise the contracted bands from superior to inferior. Finally, hemostasis was ensured using radiofrequency. Patients were followed a minimum of 7 months (mean, 17.4 months; range, 7-42 months). At last followup, the adduction and flexion ranges of the hip were 45.3 degrees +/- 8.7 degrees and 110.2 degrees +/- 11.9 degrees, compared with 10.4 degrees +/- 7.2 degrees and 44.8 degrees +/- 14.1 degrees before surgery. No hip abductor contracture recurred and no patient had residual hip pain or gluteal muscle wasting. We found gluteal muscle contracture could be released effectively with radiofrequency energy.

  20. Electron Paramagnetic Resonance Imaging: 2. Radiofrequency FT-EPR Imaging

    Indian Academy of Sciences (India)

    2016-08-01

    In this part we shall outline the challenges one faces whiledeveloping time-domain radiofrequency (RF) EPR imagingspectrometer for in vivo studies. Time-domain or FT-EPR isquite a different animal compared to the CW modality. Theevolution of FT-EPR instrumentation at the National CancerInstitute, NIH, USA and representative examples of applicationin cancer research are outlined in this article.

  1. Mitral valve perforation appearing years after radiofrequency ablation

    DEFF Research Database (Denmark)

    Fisch-Thomsen, Marie; Jensen, Jesper K; Egeblad, Henrik

    2011-01-01

    The case is reported of a young adult with Wolff-Parkinson-White (WPW) syndrome who, three years after a complicated radiofrequency (RF) catheter ablation procedure, developed dyspnea on exertion. Echocardiography revealed severe mitral valve regurgitation caused by a perforation of the posterior...

  2. Radiofrequency ablation for the treatment of gastric antral vascular ectasia

    DEFF Research Database (Denmark)

    Dray, X.; Repici, A.; Gonzalez, P.;

    2014-01-01

    Background and study aims: The traditional endoscopic treatment for gastric antral vascular ectasia (GAVE) is argon plasma coagulation, but results are not always positive. Radiofrequency ablation (RFA) is a new endoscopic therapy that may be an attractive option for the treatment of GAVE. The ai...

  3. Radiofrequency Ablation of Hepatic Metastases from Thyroid Carcinoma

    NARCIS (Netherlands)

    Wertenbroek, Marieke W. J. L. A. E.; Links, Thera P.; Prins, Ted R.; Plukker, John T. M.; van der Jagt, Erik J.; de Jong, Koert P.

    2008-01-01

    Background: Radiofrequency ablation (RFA) is performed for various types of liver tumors. It might also have a role in the palliative treatment of liver metastases from thyroid carcinoma. Summary: Three patients with liver metastases of thyroid carcinoma were retrieved from our database of 125 patie

  4. [Treatment of pulmonary vein stenosis secondary to radiofrequency ablation].

    Science.gov (United States)

    Ferrero Guadagnoli, Adolfo; Contreras, Alejandro E; Leonardi, Carlos R; Ballarino, Miguel A; Atea, Leonardo; Peirone, Alejandro R

    2014-01-01

    Isolation of the pulmonary veins by applying radiofrequency is an effective treatment for atrial fibrillation. One of the potential complications with higher clinical compromise utilizing this invasive technique is the occurrence of stenosis of one or more pulmonary veins. This complication can be treated by angioplasty with or without stent implantation, with an adequate clinical improvement, but with a high rate of restenosis.

  5. Extreme diffusion limited electropolishing of niobium radiofrequency cavities

    CERN Document Server

    Crawford, Anthony C

    2016-01-01

    Deeply modulated, continuous, diffusion-limited current waveforms for electropolishing niobium single-cell elliptical radiofrequency cavities are reliably and repeatedly achieved at Fermilab. Details of the technique and cavity test results are reported here. The method is applicable for cavity frequencies in the range 500MHz to 3.9 GHz and can be extended to multicell structures.

  6. CT-guided percutaneous radiofrequency ablation of spinal osteoid osteoma

    Institute of Scientific and Technical Information of China (English)

    LIU Chen; LIU Xiao-guang; ZHU Bin; YUAN Hui-shu; HAN Song-bo; MA Yong-qiang

    2011-01-01

    Background This study evaluated the feasibility,efficacy and safety of CT-guided percutaneous radiofrequency ablation in patients with spinal osteoid osteoma.Methods Two patients suffered spinal osteoid osteoma were treated with CT-guided percutaneous radiofrequency ablation under local anesthesia.Lesions located in sacral vertebrae and cervical vertebrae,which were adjacent to nerve root and spinal canal respectively.Tumors were treated under 90°C radiofrequency temperature lasting 4 minutes by an electrode placement.Visual analog scale was used to evaluate the pain improvement.Results No complications were observed pre- and post-operation.Patients recovered to normal activities immediately and achieved complete pain relief in 24 hours.No symptoms were recurrent in 5 months and 4 months follow up.Mild scoliosis has been recovered in case 2.Conclusions CT-guided percutaneous radiofrequency ablation of spinal osteoid osteoma is safe,effective and has more clinical benefits.The long-term outcome needs further observation.

  7. Investigation of co-genotoxic effects of radiofrequency electromagnetic fields in vivo.

    Science.gov (United States)

    Verschaeve, L; Heikkinen, P; Verheyen, G; Van Gorp, U; Boonen, F; Vander Plaetse, F; Maes, A; Kumlin, T; Mäki-Paakkanen, J; Puranen, L; Juutilainen, J

    2006-05-01

    We investigated the possible combined genotoxic effects of radiofrequency (RF) electromagnetic fields (900 MHz, amplitude modulated at 217 Hz, mobile phone signal) with the drinking water mutagen and carcinogen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX). Female rats were exposed to RF fields for a period of 2 years for 2 h per day, 5 days per week at average whole-body specific absorption rates of 0.3 or 0.9 W/kg. MX was given in the drinking water at a concentration of 19 microg/ml. Blood samples were taken at 3, 6 and 24 months of exposure and brain and liver samples were taken at the end of the study (24 months). DNA damage was assessed in all samples using the alkaline comet assay, and micronuclei were determined in erythrocytes. We did not find significant genotoxic activity of MX in blood and liver cells. However, MX induced DNA damage in rat brain. Co-exposures to MX and RF radiation did not significantly increase the response of blood, liver and brain cells compared to MX exposure only. In conclusion, this 2-year animal study involving long-term exposures to RF radiation and MX did not provide any evidence for enhanced genotoxicity in rats exposed to RF radiation.

  8. Numerical Simulations of Early-Stage Dynamics of Electron Bunches Emitted from Plasmonic Photocathodes

    CERN Document Server

    Lueangaramwong, Anusorn; Andonian, Gerard; Piot, Philippe

    2016-01-01

    High-brightness electron sources are a key ingredient to the development of compact accelerator-based light sources. The electron sources are commonly based on (linear) a photoemission process where a laser pulse with proper wavelength impinges on the surface of a metallic or semiconductor cathode. Very recently the use of plasmonic cathodes--cathodes with a nano-patterned surface--have demonstrated great enhancement in quantum efficiencies [1]. Alternatively, this cathode type could support the formation of structured beams composed of transversely separated beamlets. In this paper we discuss numerical simulations of the early-stage beam dynamics of the emission process from plasmonic cathodes using the Warp [2] framework. The model is used to investigate the properties of beams emitted from this type of cathode and combined with PIC simulation to explore the imaging of cathode pattern after acceleration in a radiofrequency gun.

  9. 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...

  10. Neodymium YAG lasers pumped by light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Bilak, V.I.; Goldobin, I.S.; Zverev, G.M.; Kuratev, I.I.; Pashkov, V.A.; Stel' makh, M.F.; Tsvetkov, Y.V.; Solov' eva, N.M.

    1981-11-01

    The results are presented of theoretical and experimental investigations of room-temperature YAG:Nd lasers pumped by light-emitting diodes. The lasing characteristics of a laser operated at the 1.06 and 1.32 ..mu.. wavelengths were investigated in the cw and pulsed regimes and dependences of its parameters on the temperature, pulse repetition frequency, and other factors were studied. In the pulsed regime the laser efficiency was 0.2% and in the cw regime the radiation power reached 50 and 17 mW at the 1.06 and 1.32 ..mu.. wavelengths, respectively.

  11. Polarization of photons emitted by decaying dark matter

    Directory of Open Access Journals (Sweden)

    W. Bonivento

    2017-02-01

    Full Text Available Radiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through the study of a polarization state of emitted photons. Starting from the basic principles of quantum mechanics we show that the models of symmetric dark matter are indiscernible by the photon polarization. However, we find that the asymmetric dark matter consisted of Dirac fermions is a source of circularly polarized photons, calling for the experimental determination of the photon state.

  12. High efficiency III-nitride light-emitting diodes

    Science.gov (United States)

    Crawford, Mary; Koleske, Daniel; Cho, Jaehee; Zhu, Di; Noemaun, Ahmed; Schubert, Martin F; Schubert, E. Fred

    2013-05-28

    Tailored doping of barrier layers enables balancing of the radiative recombination among the multiple-quantum-wells in III-Nitride light-emitting diodes. This tailored doping enables more symmetric carrier transport and uniform carrier distribution which help to reduce electron leakage and thus reduce the efficiency droop in high-power III-Nitride LEDs. Mitigation of the efficiency droop in III-Nitride LEDs may enable the pervasive market penetration of solid-state-lighting technologies in high-power lighting and illumination.

  13. Polarization of photons emitted by decaying dark matter

    CERN Document Server

    Gorbunov, D; Tokareva, A

    2016-01-01

    Radiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through the study of a polarization state of emitted photons. Starting from the basic principles of quantum mechanics we show that the models of symmetric dark matter are indiscernible by the photon polarization. However, we find that the asymmetric dark matter consisted of Dirac fermions is a source of circularly polarized photons, calling for the experimental determination of the photon state.

  14. Polarization of photons emitted by decaying dark matter

    Science.gov (United States)

    Bonivento, W.; Gorbunov, D.; Shaposhnikov, M.; Tokareva, A.

    2017-02-01

    Radiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through the study of a polarization state of emitted photons. Starting from the basic principles of quantum mechanics we show that the models of symmetric dark matter are indiscernible by the photon polarization. However, we find that the asymmetric dark matter consisted of Dirac fermions is a source of circularly polarized photons, calling for the experimental determination of the photon state.

  15. Pathophysiology of cell phone radiation: oxidative stress and carcinogenesis with focus on male reproductive system

    Directory of Open Access Journals (Sweden)

    Kesari Kavindra K

    2009-10-01

    Full Text Available Abstract Hazardous health effects stemming from exposure to radiofrequency electromagnetic waves (RF-EMW emitted from cell phones have been reported in the literature. However, the cellular target of RF-EMW is still controversial. This review identifies the plasma membrane as a target of RF-EMW. In addition, the effects of RF-EMW on plasma membrane structures (i.e. NADH oxidase, phosphatidylserine, ornithine decarboxylase and voltage-gated calcium channels are discussed. We explore the disturbance in reactive oxygen species (ROS metabolism caused by RF-EMW and delineate NADH oxidase mediated ROS formation as playing a central role in oxidative stress (OS due to cell phone radiation (with a focus on the male reproductive system. This review also addresses: 1 the controversial effects of RF-EMW on mammalian cells and sperm DNA as well as its effect on apoptosis, 2 epidemiological, in vivo animal and in vitro studies on the effect of RF-EMW on male reproductive system, and 3 finally, exposure assessment and dosimetry by computational biomodeling.

  16. Pathophysiology of cell phone radiation: oxidative stress and carcinogenesis with focus on male reproductive system.

    Science.gov (United States)

    Desai, Nisarg R; Kesari, Kavindra K; Agarwal, Ashok

    2009-10-22

    Hazardous health effects stemming from exposure to radiofrequency electromagnetic waves (RF-EMW) emitted from cell phones have been reported in the literature. However, the cellular target of RF-EMW is still controversial. This review identifies the plasma membrane as a target of RF-EMW. In addition, the effects of RF-EMW on plasma membrane structures (i.e. NADH oxidase, phosphatidylserine, ornithine decarboxylase) and voltage-gated calcium channels are discussed. We explore the disturbance in reactive oxygen species (ROS) metabolism caused by RF-EMW and delineate NADH oxidase mediated ROS formation as playing a central role in oxidative stress (OS) due to cell phone radiation (with a focus on the male reproductive system). This review also addresses: 1) the controversial effects of RF-EMW on mammalian cells and sperm DNA as well as its effect on apoptosis, 2) epidemiological, in vivo animal and in vitro studies on the effect of RF-EMW on male reproductive system, and 3) finally, exposure assessment and dosimetry by computational biomodeling.

  17. Hierarchical Non-Emitting Markov Models

    CERN Document Server

    Ristad, E S; Ristad, Eric Sven; Thomas, Robert G.

    1998-01-01

    We describe a simple variant of the interpolated Markov model with non-emitting state transitions and prove that it is strictly more powerful than any Markov model. More importantly, the non-emitting model outperforms the classic interpolated model on the natural language texts under a wide range of experimental conditions, with only a modest increase in computational requirements. The non-emitting model is also much less prone to overfitting. Keywords: Markov model, interpolated Markov model, hidden Markov model, mixture modeling, non-emitting state transitions, state-conditional interpolation, statistical language model, discrete time series, Brown corpus, Wall Street Journal.

  18. Light-Emitting Devices with Conjugated Polymers

    Directory of Open Access Journals (Sweden)

    Xian-Yu Deng

    2011-03-01

    Full Text Available This article introduces a previous study and tremendous progress in basic theoretical modeling, material developments and device engineering for polymer light-emitting devices (PLEDs.

  19. 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.

  20. Optimization of the generator settings for endobiliary radiofrequency ablation

    Institute of Scientific and Technical Information of China (English)

    Maximilien; Barret; Sarah; Leblanc; Ariane; Vienne; Alexandre; Rouquette; Frederic; Beuvon; Stanislas; Chaussade; Frederic; Prat

    2015-01-01

    AIM:To determine the optimal generator settings for endobiliary radiofrequency ablation. METHODS:Endobiliary radiofrequency ablation was performed in live swine on the ampulla of Vater,the common bile duct and in the hepatic parenchyma. Radiofrequency ablation time,"effect",and power were allowed to vary. The animals were sacrificed two hours after the procedure. Histopathological assessment of the depth of the thermal lesions was performed. RESULTS:Twenty-five radiofrequency bursts were applied in three swine. In the ampulla of Vater(n = 3),necrosis of the duodenal wall was observed starting with an effect set at 8,power output set at 10 W,and a 30 s shot duration,whereas superficial mucosal damage of up to 350 μm in depth was recorded for an effect set at 8,power output set at 6 W and a 30 s shot duration. In the common bile duct(n = 4),a 1070 μm,safe and efficient ablation was obtained for an effect set at 8,a power output of 8 W,and an ablation time of 30 s. Within the hepatic parenchyma(n = 18),the depth of tissue damage varied from 1620 μm(effect = 8,power = 10 W,ablation time = 15 s) to 4480 μm(effect = 8,power = 8 W,ablation time = 90 s). CONCLUSION:The duration of the catheter application appeared to be the most important parameter influencing the depth of the thermal injury during endobiliary radiofrequency ablation. In healthy swine,the currently recommended settings of the generator may induce severe,supratherapeutic tissue damage in the biliary tree,especially in the high-risk area of the ampulla of Vater.

  1. 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.

  2. International and National Expert Group Evaluations: Biological/Health Effects of Radiofrequency Fields

    Directory of Open Access Journals (Sweden)

    Vijayalaxmi

    2014-09-01

    Full Text Available The escalated use of various wireless communication devices, which emit non-ionizing radiofrequency (RF fields, have raised concerns among the general public regarding the potential adverse effects on human health. During the last six decades, researchers have used different parameters to investigate the effects of in vitro and in vivo exposures of animals and humans or their cells to RF fields. Data reported in peer-reviewed scientific publications were contradictory: some indicated effects while others did not. International organizations have considered all of these data as well as the observations reported in human epidemiological investigations to set-up the guidelines or standards (based on the quality of published studies and the “weight of scientific evidence” approach for RF exposures in occupationally exposed individuals and the general public. Scientists with relevant expertise in various countries have also considered the published data to provide the required scientific information for policy-makers to develop and disseminate authoritative health information to the general public regarding RF exposures. This paper is a compilation of the conclusions, on the biological effects of RF exposures, from various national and international expert groups, based on their analyses. In general, the expert groups suggested a reduction in exposure levels, precautionary approach, and further research.

  3. Radiofrequency Field Distribution Assessment in Indoor Areas Covered by Wireless Local Area Network

    Directory of Open Access Journals (Sweden)

    HELBET, R.

    2009-02-01

    Full Text Available Electromagnetic environment becomes day by day more congested. Radio communication systems in the short range are now part of everyday life, and there is a need to also assess the pollution level due to their emission if we take into account human health and protection. There is consistent scientific evidence that environmental electromagnetic field may cause undesirable biological effects or even health hazards. Present paper aims at giving a view on exposure level due to wireless local area networks (WLAN emission solely, as part of environmental radiofrequency pollution. Highly accurate measurements were made indoor by using a frequency-selective measurement system and identifying the correct settings for an error-minimum assessment. We focused on analysis of the electric flux density distribution inside a room, in the far field of the emitting antennas, in case of a single network communication channel. We analyze the influence the network configuration parameters have on the field level. Distance from the source and traffic rate are also important parameters that affect the exposure level. Our measurements indicate that in the immediate vicinity of the WLAN stations the average field may reach as much as 13% from the present accepted reference levels given in the human exposure standards.

  4. Compatibility of Radiofrequency Surgical Sponge Detection Technology with Cardiac Implantable Electronic Devices and Temporary Pacemakers.

    Science.gov (United States)

    Salcedo, Jonathan D; Pretorius, Victor G; Hsu, Jonathan C; Lalani, Gautam G; Schricker, Amir A; Hebsur, Shrinivas M; McGARRY, Thomas J; Hunter, Jessica A; Lewis, Kathryn E; Krummen, David E; Feld, Gregory K; Birgersdotter-Green, Ulrika

    2016-11-01

    Radiofrequency (RF) technology has improved detection of retained surgical sponges with a reported 100% sensitivity and specificity. However, the potential for interactions of the RF signals emitted by the detection system with cardiac implantable electronic devices (CIEDs) or temporary pacemakers may limit its use in those patients with these devices. This study investigated whether RF detection technology causes interference or clinically significant changes in the programmed settings of implanted pacemakers and defibrillators or temporary epicardial pacemakers. Fifty patients who were scheduled either for CIED removal or placement of a temporary epicardial pacemaker (at the time of open heart surgery) were recruited for this study. Device settings and measurements from separate interrogations before and after scanning with the RF detection system were compared. For the temporary pacemakers, we observed for any changes in hemodynamics or signs of pacing interference. Twenty (40%) pacemakers, 20 (40%) implantable cardioverter defibrillators, and 10 (20%) temporary pacemakers were analyzed in this study. During scanning, no signal interference was detected in any permanent device, and there were no significant changes in programmed settings after scanning with the RF detection system. However, pacing inhibition was detected with temporary pacing systems when programmed to a synchronous mode (DDD). RF detection technology can be safely used to scan for retained surgical sponges in patients with permanent CIEDs and temporary pacemakers set to asynchronous mode. © 2016 Wiley Periodicals, Inc.

  5. Mobile phone radiofrequency exposure has no effect on DNA double strand breaks (DSB) in human lymphocytes.

    Science.gov (United States)

    Danese, Elisa; Lippi, Giuseppe; Buonocore, Ruggero; Benati, Marco; Bovo, Chiara; Bonaguri, Chiara; Salvagno, Gian Luca; Brocco, Giorgio; Roggenbuck, Dirk; Montagnana, Martina

    2017-07-01

    The use of mobile phones has been associated with an increased risk of developing certain type of cancer, especially in long term users. Therefore, this study was aimed to investigate the potential genotoxic effect of mobile phone radiofrequency exposure on human peripheral blood mononuclear cells in vitro. The study population consisted in 14 healthy volunteers. After collection of two whole blood samples, the former was placed in a plastic rack, 1 cm from the chassis of a commercial mobile phone (900 MHz carrier frequency), which was activated by a 30-min call. The second blood sample was instead maintained far from mobile phones or other RF sources. The influence of mobile phone RF on DNA integrity was assessed by analyzing γ-H2AX foci in lymphocytes using immunofluorescence staining kit on AKLIDES. No measure of γ-H2AX foci was significantly influenced by mobile phone RF exposure, nor mobile phone exposure was associated with significant risk of genetic damages in vitro (odds ratio comprised between 0.27 and 1.00). The results of this experimental study demonstrate that exposure of human lymphocytes to a conventional 900 MHz RF emitted by a commercial mobile phone for 30 min does not significantly impact DNA integrity.

  6. Reduction and degradation of amyloid aggregates by a pulsed radio-frequency cold atmospheric plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Bayliss, D L; Walsh, J L; Iza, F; Kong, M G [Department of Electronic and Electrical Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Shama, G [Department of Chemical Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)], E-mail: m.g.kong@lboro.ac.uk

    2009-11-15

    Surface-borne amyloid aggregates with mature fibrils are used as a non-infectious prion model to evaluate cold atmospheric plasmas (CAPs) as a prion inactivation strategy. Using a helium-oxygen CAP jet with pulsed radio-frequency (RF) excitation, amyloid aggregates deposited on freshly cleaved mica discs are reduced substantially leaving only a few spherical fragments of sub-micrometer sizes in areas directly treated by the CAP jet. Outside the light-emitting part of the CAP jet, plasma treatment results in a 'skeleton' of much reduced amyloid stacks with clear evidence of fibril fragmentation. Analysis of possible plasma species and the physical configuration of the jet-sample interaction suggests that the skeleton structures observed are unlikely to have arisen as a result of physical forces of detachment, but instead by progressive diffusion of oxidizing plasma species into porous amyloid aggregates. Composition of chemical bonds of this reduced amyloid sample is very different from that of intact amyloid aggregates. These suggest the possibility of on-site degradation by CAP treatment with little possibility of spreading contamination elsewhere , thus offering a new reaction chemistry route to protein infectivity control with desirable implications for the practical implementation of CAP-based sterilization systems.

  7. Reduction and degradation of amyloid aggregates by a pulsed radio-frequency cold atmospheric plasma jet

    Science.gov (United States)

    Bayliss, D. L.; Walsh, J. L.; Shama, G.; Iza, F.; Kong, M. G.

    2009-11-01

    Surface-borne amyloid aggregates with mature fibrils are used as a non-infectious prion model to evaluate cold atmospheric plasmas (CAPs) as a prion inactivation strategy. Using a helium-oxygen CAP jet with pulsed radio-frequency (RF) excitation, amyloid aggregates deposited on freshly cleaved mica discs are reduced substantially leaving only a few spherical fragments of sub-micrometer sizes in areas directly treated by the CAP jet. Outside the light-emitting part of the CAP jet, plasma treatment results in a 'skeleton' of much reduced amyloid stacks with clear evidence of fibril fragmentation. Analysis of possible plasma species and the physical configuration of the jet-sample interaction suggests that the skeleton structures observed are unlikely to have arisen as a result of physical forces of detachment, but instead by progressive diffusion of oxidizing plasma species into porous amyloid aggregates. Composition of chemical bonds of this reduced amyloid sample is very different from that of intact amyloid aggregates. These suggest the possibility of on-site degradation by CAP treatment with little possibility of spreading contamination elsewhere , thus offering a new reaction chemistry route to protein infectivity control with desirable implications for the practical implementation of CAP-based sterilization systems.

  8. Induction of Autophagy in the Striatum and Hypothalamus of Mice after 835 MHz Radiofrequency Exposure.

    Science.gov (United States)

    Kim, Ju Hwan; Huh, Yang Hoon; Kim, Hak Rim

    2016-01-01

    The extensive use of wireless mobile phones and associated communication devices has led to increasing public concern about potential biological health-related effects of the exposure to electromagnetic fields (EMFs). EMFs emitted by a mobile phone have been suggested to influence neuronal functions in the brain and affect behavior. However, the affects and phenotype of EMFs exposure are unclear. We applied radiofrequency (RF) of 835 MHz at a specific absorption rate (SAR) of 4.0 W/kg for 5 hours/day for 4 and 12 weeks to clarify the biological effects on mouse brain. Interestingly, microarray data indicated that a variety of autophagic related genes showed fold-change within small range after 835 MHz RF exposure. qRT-PCR revealed significant up-regulation of the autophagic genes Atg5, LC3A and LC3B in the striatum and hypothalamus after a 12-week RF. In parallel, protein expression of LC3B-II was also increased in both brain regions. Autophagosomes were observed in the striatum and hypothalamus of RF-exposed mice, based on neuronal transmission electron microscopy. Taken together, the results indicate that RF exposure of the brain can induce autophagy in neuronal tissues, providing insight into the protective mechanism or adaptation to RF stress.

  9. Simulation of radio-frequency atmospheric pressure glow discharge in γ mode

    Institute of Scientific and Technical Information of China (English)

    Shang Wan-Li; Wang De-Zhen; Michael G. Kong

    2007-01-01

    The existence of two different discharge modes has been verified in an rf (radio-frequency) atmospheric pressure glow discharge (APGD) by Shi [J. Appl. Phys. 97, 023306 (2005)]. In the first mode, referred to as α mode, the discharge current density is relatively low and the bulk plasma electrons acquire the energy due to the sheath expansion.In the second mode, termed γ mode, the discharge current density is relatively high, the secondary electrons emitted by cathode under ion bombardment in the cathode sheath region play an important role in sustaining the discharge. In this paper, a one-dimensional self-consistent fluid model for rf APGDs is used to simulate the discharge mechanisms in the γmode in helium discharge between two parallel metallic planar electrodes. The results show that as the applied voltage increases, the discharge current becomes greater and the plasma density correspondingly increases, consequentially the discharge transits from the c mode into the γ mode. The high collisionality of the APGD plasma results in significant drop of discharge potential across the sheath region, and the electron Joule heating and the electron collisional energy loss reach their maxima in the region. The validity of the simulation is checked with the available experimental and numerical data.

  10. Induction of Autophagy in the Striatum and Hypothalamus of Mice after 835 MHz Radiofrequency Exposure

    Science.gov (United States)

    Kim, Hak Rim

    2016-01-01

    The extensive use of wireless mobile phones and associated communication devices has led to increasing public concern about potential biological health-related effects of the exposure to electromagnetic fields (EMFs). EMFs emitted by a mobile phone have been suggested to influence neuronal functions in the brain and affect behavior. However, the affects and phenotype of EMFs exposure are unclear. We applied radiofrequency (RF) of 835 MHz at a specific absorption rate (SAR) of 4.0 W/kg for 5 hours/day for 4 and 12 weeks to clarify the biological effects on mouse brain. Interestingly, microarray data indicated that a variety of autophagic related genes showed fold-change within small range after 835 MHz RF exposure. qRT-PCR revealed significant up-regulation of the autophagic genes Atg5, LC3A and LC3B in the striatum and hypothalamus after a 12-week RF. In parallel, protein expression of LC3B-II was also increased in both brain regions. Autophagosomes were observed in the striatum and hypothalamus of RF-exposed mice, based on neuronal transmission electron microscopy. Taken together, the results indicate that RF exposure of the brain can induce autophagy in neuronal tissues, providing insight into the protective mechanism or adaptation to RF stress. PMID:27073885

  11. Efficiency limits for the rectification of solar radiation

    Science.gov (United States)

    Mashaal, Heylal; Gordon, Jeffrey M.

    2013-05-01

    Efficiency limits for rectifying (converting AC to DC) incoherent broadband radiation are presented, prompted by establishing a fundamental bound for solar rectennas. For an individual full-wave rectifier, the bound is 2/π. The efficiency boosts attainable with cascaded rectifiers are also derived. The derivation of the broadband limit follows from the analysis of an arbitrary number of random-phase sinusoidal signals, which is also relevant for harvesting ambient radio-frequency radiation from a discrete number of uncorrelated sources.

  12. Development of novel UV emitting single crystalline film scintillators

    Science.gov (United States)

    Zorenko, Yu; Gorbenko, V.; Savchyn, V.; Voznyak, T.; Nikl, M.; Mares, J. A.; Martin, T.; Douissard, P.-A.

    2011-04-01

    The work is dedicated to development of new types of UV -emitting scintillators based on single crystalline films (SCF) of aluminimum perovskites and garnets grown by the liquid phase epitaxy (LPE) method. The development of the following three types of UV SCF scintillators is considered in this work: i) Ce-doped SCF of Y-Lu-Al-perovskites with Ce3+ emission in the 360-370 nm range with a decay time of 16-17 ns; ii) Pr-doped SCF of Y-Lu-Al garnets with Pr3+ emission in the 300-400 nm range with a decay time of 13-17 ns; iii) La3+ and Sc3+ doped SCF of Y-Lu-Al-garnets, emitting in the 290-400 nm range due to formation of the LaY,Lu, ScY,Lu and ScAl centers with decay time of 250-575 ns. The results of testing the several novel UV-emitting SCFs scintillators for visualization of X-ray images at ESFR are presented. It is shown that the UV emission of the LuAG:Sc, LuAG:La and LuAG:Pr SCFs is efficient enough for conversion of X-ray to the UV light and that these scintillators can be used for improvement of the resolution of imaging detectors in synchrotron radiation applications.

  13. Strain tunable light emitting diodes with germanium P-I-N heterojunctions

    Science.gov (United States)

    Lagally, Max G; Sanchez Perez, Jose Roberto

    2016-10-18

    Tunable p-i-n diodes comprising Ge heterojunction structures are provided. Also provided are methods for making and using the tunable p-i-n diodes. Tunability is provided by adjusting the tensile strain in the p-i-n heterojunction structure, which enables the diodes to emit radiation over a range of wavelengths.

  14. Phosphorescent Nanocluster Light-Emitting Diodes.

    Science.gov (United States)

    Kuttipillai, Padmanaban S; Zhao, Yimu; Traverse, Christopher J; Staples, Richard J; Levine, Benjamin G; Lunt, Richard R

    2016-01-13

    Devices utilizing an entirely new class of earth abundant, inexpensive phosphorescent emitters based on metal-halide nanoclusters are reported. Light-emitting diodes with tunable performance are demonstrated by varying cation substitution to these nanoclusters. Theoretical calculations provide insight about the nature of the phosphorescent emitting states, which involves a strong pseudo-Jahn-Teller distortion.

  15. Light emitting device having peripheral emissive region

    Science.gov (United States)

    Forrest, Stephen R

    2013-05-28

    Light emitting devices are provided that include one or more OLEDs disposed only on a peripheral region of the substrate. An OLED may be disposed only on a peripheral region of a substantially transparent substrate and configured to emit light into the substrate. Another surface of the substrate may be roughened or include other features to outcouple light from the substrate. The edges of the substrate may be beveled and/or reflective. The area of the OLED(s) may be relatively small compared to the substrate surface area through which light is emitted from the device. One or more OLEDs also or alternatively may be disposed on an edge of the substrate about perpendicular to the surface of the substrate through which light is emitted, such that they emit light into the substrate. A mode expanding region may be included between each such OLED and the substrate.

  16. Comparison between bipolar pulsed radiofrequency and monopolar pulsed radiofrequency in chronic lumbosacral radicular pain

    Science.gov (United States)

    Chang, Min Cheol; Cho, Yun Woo; Ahn, Sang Ho

    2017-01-01

    Abstract Background: Chronic lumbosacral radicular pain is a challenging medical problem with respect to therapeutic management. Many patients with lumbosacral radicular pain complain of persistent leg pain after transforaminal epidural steroid injection. Nowadays, pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) is widely used for controlling lumbosacral radicular pain. Methods: We evaluated the effect of bipolar PRF on the DRG for the management of lumbosacral radicular pain. In addition, we compared the effect of bipolar PRF to monopolar PRF. Fifty patients with chronic lumbosacral radicular pain were included in the study and randomly assigned to 1 of 2 groups, the bipolar or monopolar PRF group (n = 25 per group). Pain intensity was evaluated using a numeric rating scale (NRS) at pretreatment, and 1, 2, and 3 months after treatment. Results: When compared to the pretreatment NRS scores, patients in both groups showed a significant decrease in NRS scores at 1, 2, and 3 months after treatment. Reductions in the NRS scores over time were significantly larger in the bipolar PRF group. Three months after treatment, 19 patients (76.0%) in the bipolar PRF group and 12 patients (48.0%) in the monopolar PRF group reported successful pain relief (pain relief of ≥50%). Conclusion: The use of bipolar PRF on the DRG can be an effective and safe interventional technique for chronic refractory lumbosacral radiculopathy, particularly in patients whose pain are refractory to epidural steroid injection or monopolar PRF stimulation. PMID:28248888

  17. Shielding of emitting dust particles

    Science.gov (United States)

    Luca Delzanno, Gian; Lapenta, Giovanni; Rosenberg, Marlene

    2003-10-01

    In the present work we focus on the role of electron emission (either thermionic or photoelectric) in charging an object immersed in a plasma. In fact, it is well known that the higher mobility of the plasma electrons (that would lead to negatively charged objects) can be overcome by electron emission, thus reversing the object polarity. Moreover, recent work [1] has shown how electron emission can fundamentally affect the shielding potential around the dust. In particular, depending on the physical parameters of the system (that were chosen such to correspond to common experimental conditions), the shielding potential can develop an attractive potential well. The aim of the present work is two-fold. First, we will present a parametric study in order to enlight the conditions for the formation, as well as the stability of the well. Furthermore, simulations will be presented with physical parameters corresponding to the ionosphere, thus extending our study to the case of meteroids. [1] G.L. Delzanno, G. Lapenta, M. Rosenberg, "Attractive Potential among Thermionically Emitting Microparticles", submitted.

  18. Majorana fermions coupled to electromagnetic radiation

    Science.gov (United States)

    Ohm, Christoph; Hassler, Fabian

    2014-01-01

    We consider a voltage-biased Josephson junction between two nanowires hosting Majorana zero modes which occur as topological protected zero-energy excitations at the junction. We show that two Majorana fermions localized at the junction, despite being neutral particles, interact with the electromagnetic field and generate coherent radiation similar to the conventional Josephson radiation. Within a semiclassical analysis of the radiation field, we find that the phase of the radiation gets locked to the superconducting phase difference and that the radiation is emitted at half the Josephson frequency. In order to confirm the coherence of the radiation, we study correlations of the radiation emitted by two spatially separated junctions in a dc-SQUID geometry taking into account decoherence due to spontaneous state-switches as well as due to quasi-particle poisoning.

  19. Measurement of Electromagnetic Fields Emitted from Some Medical Devices

    Directory of Open Access Journals (Sweden)

    Shaker Faisel

    2013-04-01

    Full Text Available     New medical devices such as surgery devices, physiotherapy devices, cosmetological devices and Magnetic Resonance Imaging (MRI systems generate a complex electromagnetic fields, so they consider as a potential   hazard for medical personnel during surgical procedures. The aim of this research is to detect the EMFs emitted from medical devices and determine the safety ranges from these devices which emit EMF radiations in order to protect Medical staff from its risks. The research has been performed in two parts, numerical calculation and practical measurement. Practical measurements are done in Dijlah hospital at Tikrit city. Obtaining results shows that the practical measurements are consistent with the mathematical calculation results. Comparison of these results with the safety standard guideline limits shows that they   are within the acceptable exposure limits recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP and that means there is no health risk from exposure to these fields if the exposure is for a short and not continued periods and lay within the acceptable limits.    

  20. Proton synchrotron radiation at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Thurman-Keup, Randy; /Fermilab

    2006-05-01

    While protons are not generally associated with synchrotron radiation, they do emit visible light at high enough energies. This paper presents an overview of the use of synchrotron radiation in the Tevatron to measure transverse emittances and to monitor the amount of beam in the abort gap. The latter is necessary to ensure a clean abort and prevent quenches of the superconducting magnets and damage to the silicon detectors of the collider experiments.

  1. Pulmonary radiofrequency ablation (Part 2): Procedure and follow-up.

    Science.gov (United States)

    Plasencia Martínez, J M

    2015-01-01

    Pulmonary radiofrequency ablation requires more than just interventional radiology skills. Patients must be selected carefully, and the acts that need to be done before, during, and after the procedure must be coordinated. To guarantee patient safety, radiologists need to know the variants of the technique, the precautions that must be taken, the complications that can occur, and the risks involved. Early differentiation between tumor tissue and normal changes secondary to treatment on imaging tests will make it possible to repeat the treatment without delays, and this will increase survival. This article describes how to coordinate and carry out pulmonary radiofrequency ablation, the complications of the technique, and the current evidence in follow-up. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  2. Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucos Metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Wang, G.; Volkow, N.D.; Tomasi, D.; Wang, G.-J.; Vaska, P.; Fowler, J.S.; Telang, F.; Alexoff, D.; Logan, J.; Wong, C.

    2011-03-01

    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 ({sup 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{sup 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

  3. Survey of ambient electromagnetic and radio-frequency interference levels in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kercel, S.W.; Moore, M.R.; Blakeman, E.D.; Ewing, P.D.; Wood, R.T.

    1996-11-01

    This document reports the results of a survey of ambient electromagnetic conditions in representative nuclear power plants. The U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research engaged the Oak Ridge National Laboratory (ORNL) to perform these measurements to characterize the electromagnetic interference (EMI) and radio-frequency interference (RFI) levels that can be expected in nuclear power plant environments. This survey is the first of its kind, being based on long-term unattended observations. The data presented in this report were measured at eight different nuclear units and required 14 months to collect. A representative sampling of power plant conditions (reactor type, operating mode, site location) monitored over extended observation periods (up to 5 weeks) were selected to more completely determine the characteristic electromagnetic environment for nuclear power plants. Radiated electric fields were measured over the frequency range of 5 MHz to 8 GHz. Radiated magnetic fields and conducted EMI events were measured over the frequency range of 305 Hz to 5 MHz. Highest strength observations of the electromagnetic ambient environment across all measurement conditions at each site provide frequency-dependent profiles for EMI/RFI levels in nuclear power plants.

  4. Study of variations of radiofrequency power density from mobile phone base stations with distance.

    Science.gov (United States)

    Ayinmode, B O; Farai, I P

    2013-10-01

    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.

  5. 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.

  6. Capacitively coupled radio-frequency discharges in nitrogen at low pressures

    KAUST Repository

    Alves, Luís Lemos

    2012-07-06

    This paper uses experiments and modelling to study capacitively coupled radio-frequency (rf) discharges in pure nitrogen, at 13.56MHz frequency, 0.11 mbar pressures and 230W coupled powers. Experiments performed on two similar (not twin) setups, existing in the LATMOS and the GREMI laboratories, include electrical and optical emission spectroscopy (OES) measurements. Electrical measurements give the rf-applied and the direct-current-self-bias voltages, the effective power coupled to the plasma and the average electron density. OES diagnostics measure the intensities of radiative transitions with the nitrogen second-positive and first-negative systems, and with the 811.5 nm atomic line of argon (present as an actinometer). Simulations use a hybrid code that couples a two-dimensional time-dependent fluid module, describing the dynamics of the charged particles (electrons and positive ions N 2 + and N 4 + ), and a zero-dimensional kinetic module, describing the production and destruction of nitrogen (atomic and molecular) neutral species. The coupling between these modules adopts the local mean energy approximation to define spacetime-dependent electron parameters for the fluid module and to work out spacetime-averaged rates for the kinetic module. The model gives general good predictions for the self-bias voltage and for the intensities of radiative transitions (both average and spatially resolved), underestimating the electron density by a factor of 34. © 2012 IOP Publishing Ltd.

  7. Radiofrequency ablation of recurrent cholangiocarcinoma after orthotopic liver transplantation - a case report

    Institute of Scientific and Technical Information of China (English)

    Rakesh Rai; Derek Manas; John Rose

    2005-01-01

    AIM: To report the use of radiofrequency ablation in the treatment of recurrenct cholangiocarcinoma in the transplanted liver.METHODS: A lady who underwent orthotopic liver transplantation (OLT) for intrahepatic cholangiocarcinoma recurrence of tumour 13 mo after tralsplantation inspite of adjuvant chemotherapy. Her recurrent tumour was treated with radiofrequency ablation.RESULTS: She survived for 18 mo following the recurrence of her tumour.CONCLUSION: Radiofrequency ablation can be used safely in the transplanted liver to treat recurrent tumour.

  8. ALICE Transition Radiation Detector (TRD), test beam.

    CERN Multimedia

    2003-01-01

    Electrons and positrons can be discriminated from other charged particles using the emission of transition radiation - X-rays emitted when the particles cross many layers of thin materials. To develop such a Transition Radiation Detector(TRD) for ALICE many detector prototypes were tested in mixed beams of pions and electrons, as in the example shown here.

  9. Thermal Ablation for Benign Thyroid Nodules: Radiofrequency and Laser

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Jung Hwan; Lee, Jeong Hyun [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Valcavi, Roberto [Endocrinology Division and Thyroid Disease Center, Arcispedale Santa Maria Nuova, Reggio Emilia (Italy); Pacella, Claudio M. [Diagnostic Imaging and Interventional Radiology Department, Ospedale Regina Apostolorum, Albano Laziale-Rome (IT); Rhim, Hyun Chul [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Na, Dong Kyu [Human Medical Imaging and Intervention Center, Seoul (Korea, Republic of)

    2011-10-15

    Although ethanol ablation has been successfully used to treat cystic thyroid nodules, this procedure is less effective when the thyroid nodules are solid. Radiofrequency (RF) ablation, a newer procedure used to treat malignant liver tumors, has been valuable in the treatment of benign thyroid nodules regardless of the extent of the solid component. This article reviews the basic physics, techniques, applications, results, and complications of thyroid RF ablation, in comparison to laser ablation.

  10. One and Two Photon Excitation of Radiofrequency Trapped Ca+

    Institute of Scientific and Technical Information of China (English)

    C. Zumsteg; C. Champenois; D. Guyomarc'h; G. Hagel; M. Houssin; M. Knoop

    2009-01-01

    Radiofrequency (rf) trapped ions are versatile candidates for a large panel of applications ranging from quantum information to the creation of cold molecules. Sample size can range from a single to 106 ions, and the internal and external energy states of the atoms can be controlled with high precision. In the experiment, we focus on different protocols related to frequency metrology using rf trapped Ca+.

  11. Arthroscopic Gluteal Muscle Contracture Release With Radiofrequency Energy

    OpenAIRE

    LIU Yu-jie; Wang, Yan; Xue, Jing; Lui, Pauline Po-Yee; Chan, Kai-Ming

    2008-01-01

    Gluteal muscle contracture is common after repeated intramuscular injections and sometimes is sufficiently debilitating to require open surgery. We asked whether arthroscopic release of gluteal muscle contracture using radiofrequency energy would decrease complications with clinically acceptable results. We retrospectively reviewed 108 patients with bilateral gluteal muscle contractures (57 males, 51 females; mean age, 23.7 years). We used inferior, anterosuperior, and posterosuperior portals...

  12. Water-cooled radiofrequency neuroablation for sacroiliac joint dysfunctional pain

    OpenAIRE

    2016-01-01

    Sacroiliac (SI) joint dysfunction is a common source of chronic low-back pain. Recent evidences from different parts of the world suggest that cooled radiofrequency (RF) neuroablation of sacral nerves supplying SI joints has superior pain alleviating properties than available existing treatment options for SI joint dysfunctional pain. A 35-year-old male had intractable bilateral SI joint pain (numeric rating scale [NRS] - 9/10) with poor treatment response to intra-articular steroid therapy. ...

  13. Primary papillary thyroid carcinoma previously treated incompletely with radiofrequency ablation

    OpenAIRE

    Kim Hoon; Ryu Woo; Woo Sang; Son Gil; Lee Eun; Lee Jae; Bae Jeoung

    2010-01-01

    Radiofrequency ablation (RFA) recently has been applied to benign thyroid nodules, mainly for the cosmetic reasons, and limited cases of local recurrences or focal distant metastases of well-differentiated thyroid cancer, in the high-risk reoperative condition or for the palliative purpose. But no report has been made on the RFA for primary thyroid cancer to date. We report on a patient with primary papillary carcinoma of thyroid gland who had undergone RFA before the cytological diagnosis of...

  14. Surgical and Pathological Changes after Radiofrequency Ablation of Thyroid Nodules

    OpenAIRE

    Chiara Dobrinja; Stella Bernardi; Bruno Fabris; Rita Eramo; Petra Makovac; Gabriele Bazzocchi; Lanfranco Piscopello; Enrica Barro; Nicolò de Manzini; Deborah Bonazza; Maurizio Pinamonti; Fabrizio Zanconati; Fulvio Stacul

    2015-01-01

    Background. Radiofrequency ablation (RFA) has been recently advocated as an effective technique for the treatment of symptomatic benign thyroid nodules. It is not known to what extent it may affect any subsequent thyroid surgery and/or histological diagnosis. Materials and Methods. RFA was performed on 64 symptomatic Thy2 nodules (benign nodules) and 6 symptomatic Thy3 nodules (follicular lesions/follicular neoplasms). Two Thy3 nodules regrew after the procedure, and these patients accepted t...

  15. Radiofrequency ablation for postsurgical thyroid removal of differentiated thyroid carcinoma

    OpenAIRE

    Xu, Dong; Wang, Lipin; Long, Bin; Ye, Xuemei; Ge, MingHua; Wang, Kejing; Guo, Liang; Li, Linfa

    2016-01-01

    Differentiated thyroid carcinoma (DTC) is the most common endocrine malignancy. Surgical removal with radioactive iodine therapy is recommended for recurrent thyroid carcinoma, and the postsurgical thyroid removal is critical. This study evaluated the clinical values of radiofrequency ablation (RFA) in the postsurgical thyroid removal for DTC. 35 DTC patients who had been treated by subtotal thyroidectomy received RFA for postsurgical thyroid removal. Before and two weeks after RFA, the thyro...

  16. Sympathetic cooling of $^4$He$^+$ ions in a radiofrequency trap

    CERN Document Server

    Roth, B; Schiller, S

    2004-01-01

    We have generated Coulomb crystals of ultracold $^4$He$^+$ ions in a linear radiofrequency trap, by sympathetic cooling via laser--cooled $^9$Be$^+$. Stable crystals containing up to 150 localized He$^+$ ions at $\\sim$20 mK were obtained. Ensembles or single ultracold He$^+$ ions open up interesting perspectives for performing precision tests of QED and measurements of nuclear radii. The present work also indicates the feasibility of cooling and crystallizing highly charged atomic ions using $^9$Be$^+$ as coolant.

  17. Radiation from moving charged particles with spin

    Energy Technology Data Exchange (ETDEWEB)

    Luccio, A.

    1992-10-05

    The theory of radiation emitted by a charged particle with spin in relativistic motion in an external magnetic field is reviewed. Approximate expressions suitable numerical computation, in far and near field, are derived. In particular, the case of the passage of a particle accelerator beam through an undulator is considered. It is shown that observation of the spectrum of the emitted radiation, in its two states of polarization, can be used not only for beam diagnostics, but also to measure the spin state of the accelerated particles. Undulator radiation is compared with Compton scattering of laser light by the particle beam. Examples for high energy electron and proton colliders are presented.

  18. Hepatectomia videolaparoscópica com dispositivo de radiofrequência Laparoscopic hepatectomy with radiofrequency device

    Directory of Open Access Journals (Sweden)

    Vivian Resende

    2013-04-01

    Full Text Available As ressecções hepáticas laparoscópicas vêm ganhando adeptos entre cirurgiões pois evidenciam recuperação rápida, menor permanência hospitalar e melhor resultado estético. A utilização do dispositivo laparoscópico de radiofreqüência foi pela primeira vez utilizada, com sucesso, no Brasil, para a ressecção de carcinoma hepatocelular no segmento VI, em dois pacientes cirróticos. Apesar do sangramento intraoperatório continuar sendo um grande desafio para o cirurgião durante ressecções hepáticas laparoscópicas, em ambos os casos, a exclusão vascular hepática foi dispensável e não houve necessidade de hemotransfusão. Os pacientes receberam alta hospitalar no quarto dia pós-operatório.Laparoscopic liver resections are gaining adherents among surgeons, as they show rapid recovery, shorter hospital stay and better cosmetic results. The use of a laparoscopic radiofrequency device was first carried out successfully in Brazil for resection of hepatocellular carcinoma of the segment VI in two cirrhotic patients. Although intraoperative bleeding remains a major challenge for the surgeon during laparoscopic liver resections, in both cases the hepatic vascular exclusion was expendable and there was no need for blood transfusion. Patients were discharged on the fourth postoperative day.

  19. The radio-frequency design of an iris-type coupler for the CPHS radio-frequency quadrupole

    Science.gov (United States)

    Xiong, Zheng-Feng; Zheng, Shu-Xin; Xing, Qing-Zi; Guan, Xia-Ling

    2012-01-01

    The Compact Pulsed Hadron Source (CPHS) project is a university-based proton accelerator platform (13 MeV, 16 kW, 50 mA peak current, 0.5 ms pulse width at 50 Hz) for multi-disciplinary neutron and proton applications. The CPHS linac consists of a 3 MeV radio-frequency quadrupole (RFQ) linac and a 13 MeV drift tube linac (DTL). Both the RFQ and DTL share a 325 MHz, 2.1 MW klystron source. A single iris-type radio-frequency (RF) coupler is used to feed 537 kW of RF power to the RFQ cavity. Three-dimensional electromagnetic models of the ridge-loaded tapered waveguide (RLWG) and the coupler-cavity system are presented, and the design process and results of the RLWG and iris plate are described in detail.

  20. Electrically driven green, olivine, and amber color nanopyramid light emitting diodes.

    Science.gov (United States)

    Chang, Shih-Pang; Chang, Jet-Rung; Sou, Kuok-Pan; Liu, Mei-Chun; Cheng, Yuh-Jen; Kuo, Hao-Chung; Chang, Chun-Yen

    2013-10-07

    We report the fabrication and studies of electrically driven green, olivine, and amber color nanopyramid GaN light emitting diodes (LEDs). InGaN/GaN multiple quantum wells (MQWs) were grown on the nanopyramid semipolar facets. Compared with the commonly used (0001) c-plane MQWs, the semipolar facet has lower piezoelectric field, resulting in much faster radiative recombination efficiency. This is important for high In content MQWs. The measured internal quantum efficiencies for green, olivine, and amber color LED are 30%, 25%, and 21%, respectively. The radiative and non-radiative lifetime of the semipolar MQWs are also investigated.

  1. Pathophysiology of cell phone radiation: oxidative stress and carcinogenesis with focus on male reproductive system

    OpenAIRE

    Kesari Kavindra K; Desai Nisarg R; Agarwal Ashok

    2009-01-01

    Abstract Hazardous health effects stemming from exposure to radiofrequency electromagnetic waves (RF-EMW) emitted from cell phones have been reported in the literature. However, the cellular target of RF-EMW is still controversial. This review identifies the plasma membrane as a target of RF-EMW. In addition, the effects of RF-EMW on plasma membrane structures (i.e. NADH oxidase, phosphatidylserine, ornithine decarboxylase) and voltage-gated calcium channels are discussed. We explore the dist...

  2. Home-based wrinkle reduction using a novel handheld multisource phase-controlled radiofrequency device.

    Science.gov (United States)

    Shemer, Avner; Levy, Hanna; Sadick, Neil S; Harth, Yoram; Dorizas, Andrew S

    2014-11-01

    In the last decade, energy-based aesthetic treatments, using light, radiofrequency (RF), and ultrasound, have gained scientific acceptance as safe and efficacious for non-invasive treatment for aesthetic skin disorders. The phase-controlled multisource radiofrequency technology (3DEEP™), which is based on the simultaneous use of multiple RF generators, was proven to allow significant pigment-independent dermal heating without pain or the need of epidermal cooling. This study was performed in order to evaluate the efficacy and safety of a new handheld device delivering multisource radiofrequency to the skin for wrinkle reduction and skin tightening in the home setting. A total of 69 participants (age 54.3 years ± 8.09; age range 37-72 years) were enrolled in the study after meeting all inclusion/exclusion criteria (100%) and providing informed consent. Participants were provided with the tested device together with a user manual and treatment diary, to perform independent treatments at home for 4 weeks. The tested device, (Newa™, EndyMed Medical, Cesarea, Israel) emits 12 W of 1Mhz, RF energy through six electrodes arranged in a linear fashion. Independent control of RF polarity through each one of the 6 electrodes allows significant reduction of energy flow through the epidermis with increased dermal penetration. Participants were instructed to perform at least 5 treatments a week, for one month. Four follow-up visits were scheduled (once a week) during the period of independent treatments at home, following 4 weeks of home treatments, 1 month follow-up visit (1 month after treatment end) and at 3 months follow-up (3 months following treatment end). Analysis of pre-and post treatment images was conducted by three uninvolved physicians experienced with the Fitzpatrick Wrinkle and Elastosis Scale. Fitzpatrick Wrinkle and Elastosis score of each time point (4 weeks following home use treatments; 1 month follow-up, 3 months follow-up) was compared to baseline

  3. Radiation in Particle Simulations

    Energy Technology Data Exchange (ETDEWEB)

    More, R; Graziani, F; Glosli, J; Surh, M

    2010-11-19

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of megabars to thousands of gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known. The second method expands the electromagnetic field in normal modes (planewaves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion. The third method is a hybrid molecular dynamics/Monte Carlo (MD/MC) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions. The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc. This approach is inspired by the virial expansion method of equilibrium statistical mechanics. Using a combination of these methods we believe it is possible to do atomic-scale particle

  4. Continuous Emission of A Radiation Quantum

    CERN Document Server

    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 \\times$ frequency", is spatially extensive and stretches an electromagnetic wave train. A wave train, hence an energy quantum, can only be emitted by its source gradually. In both the two processes the wave and "particle" attributes of the radiation field are simultaneously prominent, where an overall satisfactory theory has been lacking. This paper presents a first principles treatment, in a unified framework of the classical and quantum mechanics, of the latter process, the emission of a single radiation quantum based on the dynamics of the radiation-emitting source, a charged oscillator which is itself extensive across its confining potential well. 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, whereb...

  5. Pulsed UV-C disinfection of Escherichia coli with light-emitting diodes, emitted at various repetition rates and duty cycles.

    Science.gov (United States)

    Wengraitis, Stephen; McCubbin, Patrick; Wade, Mary Margaret; Biggs, Tracey D; Hall, Shane; Williams, Leslie I; Zulich, Alan W

    2013-01-01

    A 2010 study exposed Staphylococcus aureus to ultraviolet (UV) radiation and thermal heating from pulsed xenon flash lamps. The results suggested that disinfection could be caused not only by photochemical changes from UV radiation, but also by photophysical stress damage caused by the disturbance from incoming pulses. The study called for more research in this area. The recent advances in light-emitting diode (LED) technology include the development of LEDs that emit in narrow bands in the ultraviolet-C (UV-C) range (100-280 nm), which is highly effective for UV disinfection of organisms. Further, LEDs would use less power, and allow more flexibility than other sources of UV energy in that the user may select various pulse repetition frequencies (PRFs), pulse irradiances, pulse widths, duty cycles and types of waveform output (e.g. square waves, sine waves, triangular waves, etc.). Our study exposed Escherichia coli samples to square pulses of 272 nm radiation at various PRFs and duty cycles. A statistically significant correlation was found between E. coli's disinfection sensitivity and these parameters. Although our sample size was small, these results show promise and are worthy of further investigation. Comparisons are also made with pulsed disinfection by LEDs emitting at 365 nm, and pulsed disinfection by xenon flash lamps. © 2012 U.S. Government. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  6. Radiation effects in optoelectronic devices. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, C.E.; Wiczer, J.J.

    1984-05-01

    Purpose of this report is to provide not only a summary of radiation damage studies at Sandia National Laboratories, but also of those in the literature on the components of optoelectronic systems: light emitting diodes (LEDs), laser diodes, photodetectors, optical fibers, and optical isolators. This review of radiation damage in optoelectronic components is structured according to device type. In each section, a brief discussion of those device properties relevant to radiation effects is given.

  7. 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.

  8. 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.

  9. Role of percutaneous ultrasonographic guided radiofrequency ablation in the management of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Youssef

    2014-06-01

    Conclusion: Radiofrequency thermal ablation is a simple, effective and less expensive technique with a low morbidity compared with surgical treatment. Radiofrequency thermal ablation can produce significant long-term survival rates and excellent local control for cirrhotic patients with early stage, unresectable HCC.

  10. Temporal changes in patient characteristics and prior pharmacotherapy in patients undergoing radiofrequency ablation of atrial fibrillation

    DEFF Research Database (Denmark)

    Karasoy, Deniz; Gislason, Gunnar Hilmar; Hansen, Jim

    2013-01-01

    Trends in patient selection and pharmacotherapy before radiofrequency ablation (RFA) of atrial fibrillation are not well studied. We examined temporal trends in RFA utilization on a nationwide scale in Denmark.......Trends in patient selection and pharmacotherapy before radiofrequency ablation (RFA) of atrial fibrillation are not well studied. We examined temporal trends in RFA utilization on a nationwide scale in Denmark....

  11. Radiofrequency Ablation of Benign Thyroid Nodules and Recurrent Thyroid Cancers: Consensus Statement and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Na, Dong Gyu [Human Medical Imaging and Intervention Center, Seoul (Korea, Republic of); Lee, Jeong Hyun [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Jung, So Lyung [Seoul St. Marys Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2012-06-15

    Radiofrequency ablation is a new non-surgical treatment modality for patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for the treatment of benign thyroid nodules and recurrent thyroid cancers using radiofrequency ablation. These recommendations are based on evidence from the current literature and expert consensus

  12. Quantitative sensory testing may predict response to sphenopalatine ganglion pulsed radiofrequency treatment in cluster headaches: a case series

    NARCIS (Netherlands)

    Chua Hai Liang, N.; Vissers, K.C.P.; Wilder-Smith, O.H.G.

    2011-01-01

    Pulsed radiofrequency treatment has been described as a nonablative alternative to radiofrequency thermocoagulation for the management of certain chronic pain syndromes. We present our first three patients with long-standing cluster headaches who were treated with pulsed radiofrequency to the spheno

  13. Properties of undulator radiation

    Energy Technology Data Exchange (ETDEWEB)

    Veal, B.W.

    1985-11-01

    Properties of the radiation emitted by a plane sinusoidal undulator are calculated in the far field approximation. Software has been developed to calculate the spectral distribution and polarization of the radiated intensity I(E) at a point on (or integrated over) a cross sectional observation plane of the photon beam. Spatial distribution of monochromatic radiation and power density contours are also calculated. Spectral broadening caused by an electron beam of finite spatial distribution is considered. Dispersive properties of the photon beam, including the dependence on deflection parameter, are analyzed. It is shown that reasonably constant intensity distribution I(E) can be obtained by properly shaping the beam acceptance aperture. 5 refs., 11 figs.

  14. Antenna coupling--a novel mechanism of radiofrequency electrosurgery complication: practical implications.

    Science.gov (United States)

    Robinson, Thomas N; Barnes, Kelli S; Govekar, Henry R; Stiegmann, Greg V; Dunn, Christina L; McGreevy, Francis T

    2012-08-01

    (1) To determine if antenna coupling occurs in common operating room scenarios. (2) To define modifiable clinical variables that reduce the magnitude of antenna coupling. Mechanisms of electrosurgical burns where monitoring devices contact the surgical patient are unclear. Antenna coupling occurs when the "bovie" active electrode (electrically active transmitting antenna) emits energy, which is captured by a nonelectrically active wire (electrically inactive receiving antenna) in close proximity without direct contact. Monopolar radiofrequency energy was delivered to a laparoscopic instrument (electrically active transmitting antenna), whereas other nonelectrically active wires (electrically inactive receiving antenna) including electrocardiogram (EKG) lead, nonactive "bovie" pencil, and nerve electrode monitor were placed in proximity. Temperature changes of tissue placed adjacent to the electrically inactive receiving antennae were measured. Nonelectrically active wires (receiving antenna) increase tissue temperature when lying parallel to the active electrode cord: EKG pad 2.4°C ± 1.2°C (P = 0.002), "bovie" pencil tip 90°C ± 9°C (P antenna coupling included the following: increasing angulation between transmitting and receiving antennae (parallel = 90°C ± 9°C; 45° angle = 53°C ± 10°C; perpendicular = 35°C ± 11°C; P antenna (Antenna coupling occurs in common operating room scenarios. Simple, practical measures by the surgeon, such as orienting the receiving antenna at a greater angle and with greater separation to the active electrode cord, or lowering the generator power setting reduce antenna coupling.

  15. Radiation Protection

    Science.gov (United States)

    ... EPA United States Environmental Protection Agency Search Search Radiation Protection Share Facebook Twitter Google+ Pinterest Contact Us Radiation Protection Document Library View and download EPA radiation ...

  16. Measurements of Electromagnetic Fields Emitted from Cellular Base Stations in

    Directory of Open Access Journals (Sweden)

    K. J. Ali

    2013-05-01

    Full Text Available With increasing the usage of mobile communication devices and internet network information, the entry of private telecommunications companies in Iraq has been started since 2003. These companies began to build up cellular towers to accomplish the telecommunication works but they ignore the safety conditions imposed for the health and environment that are considered in random way. These negative health effects which may cause a health risk for life beings and environment pollution. The aim of this work is to determine the safe and unsafe ranges and discuss damage caused by radiation emitted from Asia cell base stations in Shirqat city and discuses the best ways in which can be minimize its exposure level to avoid its negative health effects. Practical measurements of power density around base stations has been accomplished by using a radiation survey meter type (Radio frequency EMF Strength Meter 480846 in two ways. The first way of measurements has been accomplished at a height of 2 meters above ground for different distances from (0-300 meters .The second way is at a distance of 150 meters for different levels from (2-15 meters above ground level. The maximum measured power density is about (3 mW/m2. Results indicate that the levels of power density are far below the RF radiation exposure of USSR safety standards levels. And that means these cellular base station don't cause negative the health effect for life being if the exposure is within the acceptable international standard levels.

  17. Results of a cross-sectional study on the association of electromagnetic fields emitted from mobile phone base stations and health complaints; Ergebnisse einer Querschnittsstudie zum Zusammenhang von elektromagnetischen Feldern von Mobilfunksendeanlagen und unspezifischen gesundheitlichen Beschwerden

    Energy Technology Data Exchange (ETDEWEB)

    Breckenkamp, Juergen; Berg-Beckhoff, Gabriele [Bielefeld Univ. (Germany). Arbeitsgebiet Epidemiologie und International Public Health; Blettner, Maria [Mainz Univ. (Germany). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik; Kowall, Bernd [Duesseldorf Univ. (Germany). Deutsches Diabetes Zentrum; Schuez, Joachim [Institute of Cancer Epidemiology, Strandboulevarden (Denmark). Dept. of Biostatistics and Epidemiology; Schlehofer, Brigitte [Deutsches Krebsforschungszentrum Heidelberg (Germany). Arbeitsgebiet Umweltepidemiologie; Schmiedel, Sven [Mainz Univ. (Germany). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik; Institute of Cancer Epidemiology, Strandboulevarden (Denmark). Dept. of Biostatistics and Epidemiology; Bornkessel, Christian [Institut fuer Mobil- und Satellitenfunktechnik (IMST GmbH), Pruefzentrum EMV, Kamp-Lintfort (Germany); Reis, Ursula; Potthoff, Peter [TNS Healthcare GmbH, Muenchen (Germany)

    2010-07-01

    Background: Despite the fact that adverse health effects are not confirmed for exposure to radiofrequency electromagnetic field (RFEMF) levels below the limit values, as defined in the guidelines of the International Commission on Non-Ionizing Radiation Protection, many persons are worried about possible adverse health effects caused by the RF-EMF emitted from mobile phone base stations, or they attribute their unspecific health complaints like headache or sleep disturbances to these fields. Method: In the framework of a cross-sectional study a questionnaire was sent to 4150 persons living in predominantly urban areas. Participants were asked whether base stations affected their health. Health complaints were measured with standardized health questionnaires for sleep disturbances, headache, health complaints and mental and physical health. 3,526 persons responded (85%) to the questionnaire and 1,808 (51%) agreed to dosimetric measurements in their flats. Exposure was measured in 1,500 flats. Results: The measurements accomplished in the bedrooms in most cases showed very low exposure values, most often below sensitivity limit of the dosimeter. An association of exposure with the occurrence of health complaints was not found, but an association between the attribution of adverse health effects to base stations and the occurrence of health complaints. Conclusions: However, concerns about health and the attribution of adverse health effects to these mobile phone base stations should be taken serious and require a risk communication with concerned persons. Future research should focus on the processes of perception and appraisal of RF-EMF risks, and ascertain the determinants of concerns and attributions in the context of RF-EMF. (orig.)

  18. Effects of radiation on laser diodes.

    Energy Technology Data Exchange (ETDEWEB)

    Phifer, Carol Celeste

    2004-09-01

    The effects of ionizing and neutron radiation on the characteristics and performance of laser diodes are reviewed, and the formation mechanisms for nonradiative recombination centers, the primary type of radiation damage in laser diodes, are discussed. Additional topics include the detrimental effects of aluminum in the active (lasing) volume, the transient effects of high-dose-rate pulses of ionizing radiation, and a summary of ways to improve the radiation hardness of laser diodes. Radiation effects on laser diodes emitting in the wavelength region around 808 nm are emphasized.

  19. RADIOFREQUENCY ABLATION USING HYPERTONIC SALINE SOLUTION INSTILLATION: AN EX VIVO STUDY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To determine whether radiofrequency ablation using hypertonic saline solution instillation can increase the extent of thermally mediated coagulation in ex vivo pig liver tissue. Methods Fifty-six radiofrequency ablation lesions were produced in fresh ex vivo pig's liver. According to different saline solutions, the lesions were divided into six groups: 25% acetic acid, 18% NaCl, 10% NaCl, 5% NaCl, 0.9% NaCl, and distilled water. After radiofrequency ablation, the lesions size and morphology were measured and compared.Results Using different instillation, the volume of coagulation necrosis was different: 25% acetic acid >18% NaCl >10% NaCl >5% NaCl >0.9% NaCl>distilled water. Conclusion Radiofrequency ablation using hypertonic saline solution instillation can increase the volume of radiofrequency ablation induced necrosis.

  20. Radiation in Particle Simulations

    Energy Technology Data Exchange (ETDEWEB)

    More, R M; Graziani, F R; Glosli, J; Surh, M

    2009-06-15

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of Megabars to thousands of Gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known (section 3). The second method expands the electromagnetic field in normal modes (plane-waves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion (section 4). The third method is a hybrid MD/MC (molecular dynamics/Monte Carlo) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions (section 5). The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc.(section 6). This approach is inspired by the Virial expansion method of equilibrium statistical mechanics.

  1. RADIATION AND EFFECTS ON HUMAN HEALTH

    Directory of Open Access Journals (Sweden)

    Hakan YAREN

    2005-08-01

    Full Text Available In modern world, living without radiation is impossible. Radiation is defined as ?energy transmitted through space as waves or particles? and also determined as ?particles or waves emitted from the nucleus of unstable radioactive atoms to become stable? Mainly two types of radiation are exist; ionising radiation and non-ionising radiation. Ionising radiation is consist of alpha, beta particules, neutrons, x rays and gamma rays. Ionising radiation which can be measured by ion chambers, geiger-Mueller detectors, Scintillation Counters, fluorescent counters etc. Has harmfull effects on human health in levels of molecular, cellular, tissue, organs and organ systems. These harmfull effects can also be named somatic and genetic. One of the most encountered problem is ?Acute Radiation Syndrom? which has three sub syndroms called haematopoetic syndrom, gastrointestinal syndrom and neurovascular syndrom. Exposure time, distance and armorisation are the key elements of protection from radiation. [TAF Prev Med Bull 2005; 4(4.000: 199-208

  2. Radiofrequency identification and medical devices: the regulatory framework on electromagnetic compatibility. Part II: active implantable medical devices.

    Science.gov (United States)

    Mattei, Eugenio; Censi, Federica; Triventi, Michele; Bartolini, Pietro; Calcagnini, Giovanni

    2012-05-01

    The number and the types of electromagnetic emitters to which patients with active implantable medical devices (AIMD) are exposed to in their daily activities have proliferated over the last decade. Radiofrequency identification (RFID) is an example of wireless technology applied in many fields. The interaction between RFID emitters and AIMD is an important issue for patients, industry and regulators, because of the risks associated with such interactions. The different AIMDs refer to different standards that address the electromagnetic immunity issue in different ways. Indeed, different test setups, immunity levels and rationales are used to guarantee that AIMDs are immune to electromagnetic nonionizing radiation. In this article, the regulatory framework concerning electromagnetic compatibility between RFID systems and AIMDs is analyzed to understand whether and how the application of the current AIMD standards allows for the effective control of the possible risks associated with RFID technology.

  3. Intraductal radiofrequency ablation for management of malignant biliary obstruction.

    Science.gov (United States)

    Rustagi, Tarun; Jamidar, Priya A

    2014-11-01

    Self-expandable metal stents (SEMS) are the current standard of care for the palliative management of malignant biliary strictures. Recently, endoscopic ablative techniques with direct affect to local tumor have been developed to improve SEMS patency. Several reports have demonstrated the technical feasibility and safety of intraductal radiofrequency ablation (RFA), by both endoscopic and percutaneous approaches, in palliation of malignant strictures of the bile duct. Intraductal RFA has also been used in the treatment of occlusion of both covered and uncovered SEMS occlusion from tumor ingrowth or overgrowth. This article provides a comprehensive review of intraductal RFA in the management of malignant biliary obstruction.

  4. Eddy current imaging with an atomic radio-frequency magnetometer

    CERN Document Server

    Wickenbrock, Arne; Blanchard, John W; Budker, Dmitry

    2016-01-01

    We use a radio-frequency $^{85}$Rb alkali-vapor cell magnetometer based on a paraffin-coated cell with long spin-coherence time and a small, low-inductance driving coil to create highly resolved conductivity maps of different objects. We resolve sub-mm features in conductive objects, we characterize the frequency response of our technique, and by operating at frequencies up to 250 kHz we are able to discriminate between differently conductive materials based on the induced response. The method is suited to cover a wide range of driving frequencies and can potentially be used for detecting non-metallic objects with low DC conductivity.

  5. Probing properties of cold radiofrequency plasma with polymer probe

    Science.gov (United States)

    Bormashenko, E.; Chaniel, G.; Multanen, V.

    2015-01-01

    The probe intended for the characterization of cold plasma is introduced. The probe allows the estimation of Debye length of cold plasma. The probe is based on the pronounced modification of surface properties (wettability) of polymer films by cold plasmas. The probe was tested with the cold radiofrequency inductive air plasma discharge. The Debye length and the concentration of charge carriers were estimated for various gas pressures. The reported results coincide reasonably with the corresponding values established by other methods. The probe makes possible measurement of characteristics of cold plasmas in closed chambers.

  6. Subsurface Laser and Radiofrequency for Face and Body Rejuvenation.

    Science.gov (United States)

    DiBernardo, Barry E; DiBernardo, Gabriella; Pozner, Jason N

    2016-07-01

    Minimally invasive devices are a departure from standard laser therapies, because energy is delivered directly below the skin through a 1-mm incision. Lasers can affect such tissues as fat for enhanced disruption, coagulation of small blood vessels, and skin tightening at the right temperatures. Minimally invasive radiofrequency devices can tighten skin but can also improve neck muscle laxity. These devices can achieve results not possible with traditional external devices and, because the skin is not penetrated with energy, a much improved healing profile is seen as well. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Electromagnetic induction imaging with a radio-frequency atomic magnetometer

    CERN Document Server

    Deans, Cameron; Hussain, Sarah; Renzoni, Ferruccio

    2016-01-01

    We report on a compact, tunable, and scalable to large arrays imaging device, based on a radio-frequency optically pumped atomic magnetometer operating in magnetic induction tomography modality. Imaging of conductive objects is performed at room temperature, in an unshielded environment and without background subtraction. Conductivity maps of target objects exhibit not only excellent performance in terms of shape reconstruction but also demonstrate detection of sub-millimetric cracks and penetration of conductive barriers. The results presented here demonstrate the potential of a future generation of imaging instruments, which combine magnetic induction tomography and the unmatched performance of atomic magnetometers.

  8. Radiofrequency Ablation for Iatrogenic Thyroid Artery Pseudoaneurysm: Initial Experience.

    Science.gov (United States)

    Jun, Ye Kyeong; Jung, So Lyung; Byun, Ho Kyun; Baek, Jung Hwan; Sung, Jin Yong; Sim, Jung Suk

    2016-10-01

    Eight iatrogenic thyroid pseudoaneurysms (ITPAs) after thyroid biopsy are reported. The mean ITPA diameter was 7.2 mm (range 4 to 12 mm). Ultrasound (US)-guided compression was initially performed at the neck of the ITPA in all cases. Among them, 4 ITPAs persisted (50%) in which radiofrequency (RF) ablation was performed. Mean RF ablation time and power were 13.5 seconds (range 5 to 24 seconds) and 20 W (range 10 to 50 W), respectively. All 4 cases were treated with RF ablation without any complications.

  9. Probing Properties of Cold Radiofrequency Plasma with Polymer Probe

    CERN Document Server

    Bormashenko, Edward; Multanen, Victor

    2014-01-01

    The probe intended for the characterization of cold plasma is introduced. The probe allows estimation of the Debye length of the cold plasma. The probe is based on the pronounced modification of surface properties (wettability) of polymer films by cold plasmas. The probe was tested with the cold radiofrequency inductive air plasma discharge. The Debye length and the concentration of charge carriers were estimated for various gas pressures. The reported results coincide reasonably with the corresponding values established by other methods. The probe makes possible measurement of characteristics of cold plasmas in closed chambers.

  10. Lesion size in relation to ablation site during radiofrequency ablation

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, A;

    1998-01-01

    convective cooling by induction of a flow around the electrode tip increases lesion dimensions and power consumptions. Furthermore we conclude that for the given target temperature the power consumption is positively correlated with lesion volume (p ...This study was designed to investigate the effect of the convective cooling of the tip of the ablation electrode during temperature controlled radiofrequency ablation. In vivo two different application sites in the left ventricle of anaesthetised pigs were ablated and in vitro ablation...... larger for septal applications than apical applications (p convective cooling by induction of flow yielded larger lesion volume, depth and width (p

  11. Radiofrequency Ablation of Hepatic Paragonimiasis:a Case Report

    Institute of Scientific and Technical Information of China (English)

    Wei-gang Cao; Bao-an Qiu

    2012-01-01

    HEPATIC paragonimiasis is a rare disease with non-specific manifestation,which is often misdiagnosed in clinical practice.Long-time drug therapy treating this disease would be accompanied by the possible development of side effects.Given the fact that this disease has seldom been reported in the literature,we provide in this article a detailed report of one case with hepatic paragonimiases treated by radiofrequency ablation,which brought favorable outcome,aiming to shed some light on the understanding of this rare condition.

  12. Thyroid radiofrequency ablation: Updates on innovative devices and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye Sun; Baek, Jung Hwan; Chung, Sae Rom; Choi, Young Jun; Lee, Jeong Hyun [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Park, Auh Whan [Dept. of Radiology, Vascular and Interventional Radiology Section, University of Virginia Health System, Charlottesville (United States)

    2017-08-01

    Radiofrequency ablation (RFA) is a well-known, effective, and safe method for treating benign thyroid nodules and recurrent thyroid cancers. Thyroid-dedicated devices and basic techniques for thyroid RFA were introduced by the Korean Society of Thyroid Radiology (KSThR) in 2012. Thyroid RFA has now been adopted worldwide, with subsequent advances in devices and techniques. To optimize the treatment efficacy and patient safety, understanding the basic and advanced RFA techniques and selecting the optimal treatment strategy are critical. The goal of this review is to therefore provide updates and analysis of current devices and advanced techniques for RFA treatment of benign thyroid nodules and recurrent thyroid cancers.

  13. Radiofrequency ablation for incidentally identified primary intrahepatic cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Witold Zgodzinski; N.Joseph Espat

    2005-01-01

    Cholangiocarcinoma is the second most common primary hepato-biliary malignancy. The majority of patients with primary hepatic tumors are not suitable candidates for resection, due to advanced stage of the disease at presentation, anatomic limitations and medical comorbidities. At present, radiofrequency ablation (RFA) may offer an alternative, feasible and safe therapy for selected patients with hepatic tumors, who are not otherwise candidates for hepatic resection. Herein, we present the case of successful RFA in a patient with a solitary, primary intrahepatic cholangiocarcinoma. The patient remained free of disease 24 mo after the procedure, and is still followed up. This is the first report of RFA application inthe treatment of primary intrahepatic cholangiocarcinoma.

  14. Local recurrence of hepatocellular carcinoma after radiofrequency ablation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A 51-year-old Chinese male with a 20-year history of hepatitis B was diagnosed with hepatocellular carcinoma in the right anterior portion of the liver, sized 3.5 cm × 3.2 cm, and was treated with radiofrequency ablation (RFA) on December 18, 2001. The patient did not receive antiviral therapy for hepatitis B virus after RFA. The treated lesion reduced gradually and reached its minimum size of 1.7 cm × 1.5 cm seven years later on November 18, 2008. However computed tomography findings revealed that a recurr...

  15. Computer controls of the CERN PS radio-frequency system

    Energy Technology Data Exchange (ETDEWEB)

    Benincasa, G.P.; Garoby, R.

    1986-06-01

    The PS computer control project has recently been terminated with the integration of the radio-frequency system. While the general controls frame was used, special software and hardware solutions were also necessary to cope with the peculiarities of the RF system. After a brief description of both the RF process and the PS control system, this paper recalls the various operational requirements and real-time constraints and relates on the criteria and methods followed during the design phase. Some implementation is illustrated with emphasis on diagnostics and measurements.

  16. Computer controls of the CERN PS radio-frequency system

    Science.gov (United States)

    Benincasa, G. P.; Garoby, R.

    1986-06-01

    The PS computer control project has recently been terminated with the integration of the radio-frequency system. While the general controls frame was used, special software and hardware solutions were also necessary to cope with the peculiarities of the rf system. After a brief description of both the rf process and the PS control system, this paper recalls the various operational requirements and real-time constraints and relates on the criteria and methods followed during the design phase. Some implementation is illustrated with emphasis on diagnostics and measurements.

  17. 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)

  18. Modeling the radiation pattern of LEDs.

    Science.gov (United States)

    Moreno, Ivan; Sun, Ching-Cherng

    2008-02-01

    Light-emitting diodes (LEDs) come in many varieties and with a wide range of radiation patterns. We propose a general, simple but accurate analytic representation for the radiation pattern of the light emitted from an LED. To accurately render both the angular intensity distribution and the irradiance spatial pattern, a simple phenomenological model takes into account the emitting surfaces (chip, chip array, or phosphor surface), and the light redirected by both the reflecting cup and the encapsulating lens. Mathematically, the pattern is described as the sum of a maximum of two or three Gaussian or cosine-power functions. The resulting equation is widely applicable for any kind of LED of practical interest. We accurately model a wide variety of radiation patterns from several world-class manufacturers.

  19. Radiation Therapy

    Science.gov (United States)

    ... the area is stitched shut. Another treatment, called proton-beam radiation therapy , focuses the radiation on the ... after radiation treatment ends. Sore mouth and tooth decay. If you received radiation therapy to the head ...

  20. Radiation sickness

    Science.gov (United States)

    ... radiation. There are two basic types of radiation: ionizing and nonionizing. Nonionizing radiation comes in the form of light, radio waves, microwaves and radar. This kind of radiation usually ...