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Sample records for radiofrequences emises par

  1. Generation, compression et stabilisation d'impulsions breves emises par des lasers a semi-conducteurs

    Science.gov (United States)

    Langlois, Patrick

    1998-09-01

    Dans une premiere partie de la these (chapitres 1 et 2), nous presentons de nouvelles avenues pour produire des impulsions plus stables et plus breves a partir d'un laser a semi-conducteurs a synchronisation modale active. Nous demontrons pour la premiere fois l'application de la methode d'injection de photons coherents ('coherent photon seeding') pour reduire efficacement le bruit des impulsions emises par cette source. La compression et l'amplification des impulsions est realisee au moyen d'une cavite en anneau extra-cavite comprenant un amplificateur laser a semi-conducteurs. Le mecanisme de compression repose sur un remodelage interferometrique. Dans la deuxieme partie (chapitres 3 et 4), nous proposons et etudions deux nouvelles methodes pour la generation d'impulsions breves avec des lasers a semi- conducteurs. Nous etablissons les conditions d'applicabilite de la synchronisation modale interferentielle a ces lasers. Nos resultats numeriques et experimentaux demontrent qu'une modulation active du gain ou des pertes dans la cavite est necessaire a l'obtention d'un regime d'operation stable. Nous presentons finalement la premiere demonstration experimentale d'un regime d'autosynchronisation modale dans les lasers a semi-conducteurs, base sur un mecanisme d'autoflexion ('self-bending'). La synchronisation modale est initiee lorsque la cavite est desalignee et operee legerement au-dessus du seuil. Des impulsions picosecondes ayant un taux de repetition de 0.8 a 6.4 GHz sont alors produites de facon synchrone dans les deux directions de la cavite.

  2. Study of electronic field emission from large surfaces under static operating conditions and hyper-frequency; Etude de l'emision electronique par effet de champ sur des surfaces larges en regime statique et hyperfrequence

    Energy Technology Data Exchange (ETDEWEB)

    Luong, M

    1997-09-01

    The enhanced electronic field emission from large area metallic surfaces lowers performances of industrial devices that have to sustain high electric field under vacuum. Despite of numerous investigations in the past, the mechanisms of such an emission have never been well clarified. Recently, research in our laboratory has pointed out the importance played by conducting sites (particles and protrusions). A refined geometrical model, called superposed protrusions model has been proposed to explain the enhanced emission by local field enhancement. As a logical continuation, the present work aims at testing this model and, in the same time, investigating the means to suppress the emission where it is undesirable. Thus, we have showed: the cause of current fluctuations in a continuous field regime (DC), the identity of emission characteristics ({beta}, A{sub e}) in both radiofrequency (RF) and DC regimes, the effectiveness of a thermal treatment by extern high density electronic bombardment, the effectiveness of a mechanical treatment by high pressure rinsing with ultra pure water, the mechanisms and limits of an in situ RF processing. Furthermore, the electronic emission from insulating particles has also been studied concurrently with a spectral analysis of the associated luminous emission. Finally, the refined geometrical model for conducting sites is reinforced while another model is proposed for some insulating sites. Several emission suppressing treatments has been explored and validated. At last, the characteristic of a RF pulsed field emitted electron beam has been checked for the first time as a possible application of such a field emission. (author)

  3. 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.

  4. The role of the F.D.G.-PET in the evaluation of efficacy of radiofrequency treatment of metastases; Role de la TEP au FDG dans l'evaluation de l'efficacite du traitement des metastases par radiofrequence. Premiers resultats

    Energy Technology Data Exchange (ETDEWEB)

    Ungureanu, C.M.; Angoue, O.; Blagosklonov, O.; Zsigmond, R.; Boulahdour, H. [CHU Jean-Minjoz, Service de Medecine Nucleaire, 25 - Besancon (France); Kastler, B. [CHU Jean-Minjoz, Service de Radiologie, 25 - Besancon (France)

    2009-09-15

    Objectives Methods such as MRI and CT usually utilized in the assessment of the radiofrequency (RF) efficacy proved to be insufficient in the early detection of the residual tumors after RF treatment. In this study, we evaluated the effectiveness of utilizing the PET-CT in the follow-up of the RF treated patients. Methods PET-CT was performed before and after five RF treatments (three patients). Absence of focally increased F.D.G. uptake was considered complete efficacy, while the presence of focally increased F.D.G. uptake was considered incomplete efficacy. The efficacy was estimated on the PET-CT performed in the same day to three months after the RF treatment. Every RF administration was followed by at least two PET-CT exams. We used radiological evaluation as a control method. Results Complete efficacy was found for three of the five RF treatments and incomplete efficacy in two cases. The disease evolution confirmed the results obtained through PET-CT in 100% of the cases studied. Conclusion This preliminary study showed that the PET-CT has the potential of evaluating the efficacy of the RF treatment. Our findings showed that the PET-CT may very early evidence the presence of residual tumors. (authors)

  5. 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

  6. Spatial analysis of noise emission at the Los Azufres geothermal field, Mich.; Analisis espacial de emision de ruido en el campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Camarena Magana, Emilio; Ordaz Mendez, Christian A. [Comision Federal de Electricidad, Residencia de Los Azufres, Morelia, Michoacan (Mexico)]. E-mail: emilio.camarena@cfe.gob.mx

    2010-01-15

    To verify noise emissions from the usual activities in an operating geothermal field, noise measurements were carried out in a 4.2 km{sup 2} area in the southern zone of the Los Azufres, Mich., geothermal field. There are seven production wells operating here and three abandoned wells. The average noise emission in the southern zone was 36.5 decibels (dB), regarded as the natural reading of environmental-noise emission. In the Christmas (valves) tree for operating production wells, the noise ranges from 70.9 to 91.7 dB, while in open discharging valves for steam-pipes, the noise can reach 118 dB. In Mexico the maximum permissible limit of noise on the periphery of a property is 68 dB in daytime and 65 dB at night. Based on measurements made at the periphery of lots where the geothermal wells are located, four out of seven production wells measured do not exceed the maximum allowable level, while the other three seem to exceed it. However no definite limits exist for the lots. It is recommended that the measurement points as indicated by the official standard in environmental matters be re-established, which will enable noise emissions by several wells that have exceeded the permissible limit, to actually fall within it. [Spanish] Se realizaron mediciones sonicas en un area de 4.2 km{sup 2} localizada en la zona sur del campo geotermico de Los Azufres, Mich., a fin de verificar la emision de ruido asociada a las actividades usuales en un campo geotermico en operacion. En esta area se encuentran siete pozos productores en operacion y tres pozos abandonados. La emision promedio de ruido en estos ultimos fue de 36.5 decibeles (dB), considerandose como la condicion natural de emision de ruido ambiental. En el arbol de valvulas de los pozos productores en operacion el ruido va de los 70.9 a los 91.7 dB, mientras que en valvulas abiertas de descarga de vaporductos la emision puede llegar hasta los 118 dB. En Mexico el limite maximo permisible de ruido en la periferia de

  7. Radiofrequency attenuator and method

    Science.gov (United States)

    Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Hall, Simon B [Palmerston North, NZ

    2009-01-20

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  8. Musculoskeletal interventional radiology: radiofrequency ablation.

    Science.gov (United States)

    Ward, Emily; Munk, Peter L; Rashid, Faisal; Torreggiani, William C

    2008-05-01

    Radiofrequency ablation is the use of low-voltage high-frequency electrical energy to heat and destroy abnormal tissues within the human body. It has gained increasing acceptance as both a primary and secondary form of treatment in the musculoskeletal system because of its excellent safety profile, ease of use, and technical success. In the musculoskeletal system, radiofrequency ablation may be used to treat a wide range of lesions that include primary lesions such as osteoid osteomas and a variety of metastases both within the osseous skeleton as well as those lying within the muscles and soft tissues. In this chapter, a background to the principles, physics, and indications of radiofrequency is presented as well as an in-depth description of radiofrequency ablation techniques that may be utilized in the musculoskeletal system.

  9. Measurement of radiofrequency fields

    Energy Technology Data Exchange (ETDEWEB)

    Leonowich, J.A.

    1992-05-01

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

  10. Radiofrequency Catheter Ablation of Parahisian Accessory Pathway

    Directory of Open Access Journals (Sweden)

    Korodi Szilamér

    2016-06-01

    Full Text Available Radiofrequency catheter ablation of parahisian accessory pathways in pre-excitation syndrome is a challenging task, due to the extremely high risk of complete atrioventricular block. In this brief report we describe the case of a 32 year-old man presenting a parahisian accessory pathway, who has been successfully treated by radiofrequency ablation. Radiofrequency catheter ablation using low-power radiofrequency current is considered to be the most appropiate method of ablation in adult patients.

  11. New-generation radiofrequency technology.

    Science.gov (United States)

    Krueger, Nils; Sadick, Neil S

    2013-01-01

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

  12. Par-tjek Manualen

    DEFF Research Database (Denmark)

    Trillingsgaard, Tea; Due, Mattias Stølen; Nørr Fentz, Hanne

    Par-tjek er et tilbud til par, der ønsker at styrke forholdet og forebygge vanskeligheder. Et Par-tjek består af et indledende online spørgeskema efterfulgt at to samtaler med en psykolog eller lignende vejleder. Ved den sidste samtale modtager parret en personlig feedback-rapport, som de kan...... arbejde videre med. Samtalerne kombinerer elementer af udredning, caseformulering, psykoedukation og parterapi. Par-tjek manualen er en vejledning til fagpersoner, der arbejder med Par-tjek....

  13. Lymphangioma circumscriptum treated with radiofrequency ablation

    Directory of Open Access Journals (Sweden)

    Silonie Sachdeva

    2011-01-01

    Full Text Available Lymphangioma circumscriptum (LC, a hamartomatous lymphatic malformation, is a therapeutic challenge for the dermatologist. Various modalities like surgical excision, lasers, and sclerotherapy have been used in the past to treat this notorious skin condition. We report the efficacy of a radiofrequency ablation in a patient with LC. The treatment efficacy of radiofrequency was satisfactory in our patient with no recurrence during 1 year follow-up period. The radiofrequency technique is a safe and economic treatment for management of LC.

  14. FooPar

    DEFF Research Database (Denmark)

    Hargreaves, F. P.; Merkle, D.

    2013-01-01

    We present FooPar, an extension for highly efficient Parallel Computing in the multi-paradigm programming language Scala. Scala offers concise and clean syntax and integrates functional programming features. Our framework FooPar combines these features with parallel computing techniques. FooPar......, results based on a empirical analysis on two supercomputers are given. We achieve close-to-optimal performance wrt. theoretical peak performance. Based on this result we conclude that FooPar allows programmers to fully access Scalas design features without suffering from performance drops when compared...

  15. Nonconsecutive Pars Interarticularis Defects.

    Science.gov (United States)

    Elgafy, Hossein; Hart, Ryan C; Tanios, Mina

    2015-12-01

    Lumbar spondylolysis is a well-recognized condition occurring in adolescents because of repetitive overuse in sports. Nonconsecutive spondylolysis involving the lumbar spine is rare. In contrast to single-level pars defects that respond well to conservative treatment, there is no consensus about the management of multiple-level pars fractures; a few reports indicated that conservative management is successful, and the majority acknowledged that surgery is often required. The current study presents a rare case of pars fracture involving nonconsecutive segments and discusses the management options. In this case report, we review the patient's history, clinical examination, radiologic findings, and management, as well as the relevant literature. An 18-year-old man presented to the clinic with worsening lower back pain related to nonconsecutive pars fractures at L2 and L5. After 6 months of conservative management, diagnostic computed tomography-guided pars block was used to localize the symptomatic level at L2, which was treated surgically; the L5 asymptomatic pars fracture did not require surgery. At the last follow-up 2 years after surgery, the patient was playing baseball and basketball, and denied any back pain. This article reports a case of rare nonconsecutive pars fractures. Conservative management for at least 6 months is recommended. Successful management depends on the choice of appropriate treatment for each level. Single-photon emission computed tomography scan, and computed tomography-guided pars block are valuable preoperative tools to identify the symptomatic level in such a case.

  16. Predicting nurses' acceptance of radiofrequency identification technology.

    Science.gov (United States)

    Norten, Adam

    2012-10-01

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

  17. Effect of Radiofrequency Radiation from Telecommunication Base ...

    African Journals Online (AJOL)

    Effect of Radiofrequency Radiation from Telecommunication Base Stations on Microbial Diversity and Antibiotic Resistance. ... We aimed to investigate the effects of radiofrequency radiation from telecommunication on bacteria diversity and antibiotic sensitivity of surrounding bacteria micro-flora. In all cases of bacteria ...

  18. suPAR

    DEFF Research Database (Denmark)

    Hodges, Gethin W; Bang, Casper N; Wachtell, Kristian

    2015-01-01

    The fundamental role of inflammation in cardiovascular disease (CVD) has prompted interest in numerous biomarkers that detect subclinical levels of inflammation. Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker that correlates significantly with cardiovascular events...... and outperforms traditional markers of inflammation such as C-reactive protein (CRP) in prognosticating a range of CVDs. Furthermore, of particular interest is the suggestion that suPAR reflects a pathophysiological pathway more closely linked with subclinical organ damage than CRP. We provide the first...... comprehensive review of suPAR in CVD and explore its function and usefulness in predicting cardiovascular events....

  19. 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...

  20. Photo and cathode luminescence emission in oxide silicium films implanted with silicium; Emision de foto y catodoluminiscencia en peliculas de oxido de silicio termico implantadas con silicio

    Energy Technology Data Exchange (ETDEWEB)

    Flores, F; Aceves, M. [Instituto Nacional de Astrofisica Optica y Electronica, Mexico, D.F. (Mexico); Carrillo, J. [Benemrita Universidad Autonoma de Puebla, Puebla (Mexico); Dominguez, C. [Universida Autonoma de Barcelona, Barcelona (Spain); Falcony, C. [Instituto Politecnico Nacional, Mexico, D.F. (Mexico)

    2001-10-01

    We studied the photo and cathodoluminescence of Silicon Rich Oxides (SRO) obtained by ion implant of Si in thermal oxides. Doses of 10{sup 1}6 cm{sup -}2 (low dose) and 10{sup 1}7 cm{sup -}2 (high dose) and implant energy of 150 keV were used. The films were annealed for 30, 60 and 180 minutes in nitrogen at 1100 Celsius degrees. The spectra show photo and cathodoluminescence emission in the visible range, the bands in the spectra change with the conditions of ion implant and annealing. The films without thermal treatment in both dose present photoluminescence bands around 1.9 eV (band B) and 2.4 eV (band C). With the thermal treatments, the band B disappears. In the case of the films with low dose, the band C shows a blue shift and a decrease in intensity. The high dose films have a band centered in 1.7 eV (band A) that increases its intensity with annealings. The cathodoluminescence bands in all the cases are in 2.7 eV (band D) and they present changes with the thermal treatments that it seems they depend on the variation in the implant parameters. [Spanish] Se estudian las propiedades de foto y la catodoluminiscencia de peliculas de oxidos de silicio ricos en Si (Silicon Rich Oxide SRO) obtenidas por implantacion ionica de Si en oxidos termicos. Se usaron dosis de 10{sup 1}6 cm{sup -}2 (dosis baja) y 10{sup 1}7 cm{sup -}2 (dosis alta) y energia de implantacion de 150 keV. Las peliculas se sometieron a tratamientos termicos por 30, 60 y 180 minutos en nitrogeno de 1100 grados centigrados. Se encontro emision foto y catodoluminiscente en el rango visible, las bandas en los espectros cambian con las condiciones de implantacion ionica y con los tratamientos termicos. Las peliculas sin tratamiento termico en ambas dosis presentan bandas de fotoluminiscencia alrededor de 1.9 eV (banda B) y 2.4 eV (banda C). Con los tratamientos termicos, la banda B desaparece. En el caso de las peliculas con dosis baja, la banda C muestra un corrimiento hacia el azul junto con una

  1. 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.

  2. PAR-Aware Large-Scale Multi-User MIMO-OFDM Downlink

    CERN Document Server

    Studer, Christoph

    2012-01-01

    We investigate an orthogonal frequency-division multiplexing (OFDM)-based downlink transmission scheme for large-scale multi-user (MU) multiple-input multiple-output (MIMO) wireless systems. The use of OFDM causes a high peak-to-average (power) ratio (PAR), which necessitates expensive and power-inefficient radio-frequency (RF) components at the base station. In this paper, we present a novel downlink transmission scheme, which exploits the massive degrees-of-freedom available in large-scale MU-MIMO-OFDM systems to achieve low PAR. Specifically, we propose to jointly perform MU precoding, OFDM modulation, and PAR reduction by solving a convex optimization problem. We develop a corresponding fast iterative truncation algorithm (FITRA) and show numerical results to demonstrate tremendous PAR-reduction capabilities. The significantly reduced linearity requirements eventually enable the use of low-cost RF components for the large-scale MU-MIMO-OFDM downlink.

  3. It's quicker "Par Avignon"!

    CERN Document Server

    2005-01-01

    For a few years, the CERN Library has been receiving books from the University of Hanover sent via Avignon, at least that's what it says on the envelope. Such a detour would mean that parcels were travelling 720 km more than the distance separating Geneva and Hanover, which would be a very strange state of affairs. The explanation lies in a spelling mistake. The sender has been stamping parcels with a stamp that says "Par Avignon prioritaire" (first-class via Avignon) instead of "Par Avion prioritaire" (First Class Air Mail), a source of much amusement to the librarians!

  4. suPAR

    DEFF Research Database (Denmark)

    Eugen-Olsen, Jesper; Giamarellos-Bourboulis, Evangelos J

    2015-01-01

    promising biomarker is soluble urokinase-type plasminogen activator receptor (suPAR). Three studies in large populations of critically ill patients and patients admitted to the emergency department have shown that concentrations >12ng/mL can safely predict unfavourable outcome. This review presents...

  5. 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.

  6. 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,

  7. PAR Loop Schedule Review

    Energy Technology Data Exchange (ETDEWEB)

    Schaffer, Jr.; W.F.

    1958-04-30

    The schedule for the installation of the PAR slurry loop experiment in the South Facility of the ORR has been reviewed and revised. The design, fabrications and Installation is approximately two weeks behind schedule at this time due to many factors; however, indications are that this time can be made up. Design is estimated to be 75% complete, fabrication 32% complete and installation 12% complete.

  8. 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...

  9. Toxicity of particles emitted by the traffic: follow-up and bibliographic synthesis final report; Toxicite des particules emises par la circulation automobile: suivi et synthese bibliographique rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Tissot, S.

    1999-12-01

    This study compiles the data published recently concerning the diesel and petrol motor emissions toxicity and in particular the effects of the particles phase. The aim of the work is to give a synthetical overview of the state of knowledge in this domain to allow a scientific argumentation concerning the toxicity risks assessment from these pollutants. The data concern epidemiological studies and also experimental studies in vivo and in vitro. (A.L.B.)

  10. 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

  11. Effects of heating with radiofrequency power on myocardial impulse conduction: is radiofrequency ablation exclusively thermally mediated?

    NARCIS (Netherlands)

    Simmers, T. A.; de Bakker, J. M.; Wittkampf, F. H.; Hauer, R. N.

    1996-01-01

    Although it is generally accepted that radiofrequency (RF) ablation causes exclusively thermally mediated effects, it has never been proved. In a previous report, temperatures required to induce conduction block in superfused canine epicardial ventricular myocardium were identified by exposure to

  12. Management of trigeminal neuralgia by radiofrequency ...

    African Journals Online (AJOL)

    Methods: This retrospective study included 312 patients (280 with idiopathic TN, 8 with secondary or symptomatic TN, 20 with atypical TN, and 4 with post herpetic neuralgia) who underwent radiofrequency thermocoagulation of trigeminal nerve. This study was done in Alexandria main university hospital over a period of 7 ...

  13. Assessment of Radiofrequency Power Density Distribution around ...

    African Journals Online (AJOL)

    Background: Global system of mobile communication (GSM) and other telecommunication technologies are now common place in Lagos state Nigeria. The introduction of GSM in 2002 considerably increased radiofrequency (RF) radiation exposure of the public from telecommunications transmitting and receiving antennae ...

  14. Parametric study of radiofrequency helium discharge under ...

    Indian Academy of Sciences (India)

    2016-11-02

    Nov 2, 2016 ... treatment of heat sensitive surfaces such as wounds. [4,22]. Compared to different types of APGD plasma sources, the radiofrequency (RF) APGD plasmas pro- duced between two naked metallic electrodes have attracted considerable interest of the researchers in recent years, due to the distinct advantage ...

  15. 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

  16. 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

  17. Radiofrequency and microwave interactions between biomolecular systems

    Czech Academy of Sciences Publication Activity Database

    Kučera, Ondřej; Cifra, Michal

    2016-01-01

    Roč. 42, č. 1 (2016), s. 1-8 ISSN 0092-0606 R&D Projects: GA ČR(CZ) GA15-17102S Institutional support: RVO:67985882 Keywords : Cell signaling * Radiofrequency * Bioelectrodynamics Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.241, year: 2016

  18. Parálisis cerebral :

    OpenAIRE

    Aguado Navarro, Ana Belén

    2013-01-01

    Se aborda el tema de la parálisis cerebral definiendo qué es, clasificando los tipos de parálisis dependiendo de la afectación y las características principales. Se explican algunos de sus tratamientos, se dan sistemas alternativos y/o aumentativos de comunicación para un alumno con PC (parálisis cerebral).

  19. Brulures par Diluant

    Science.gov (United States)

    Benbrahim, A.; Jerrah, H.; Diouri, M.; Bahechar, N.; Boukind, E.H.

    2009-01-01

    Summary La flamme de diluant est une cause non rare de brûlure dans le contexte marocain. Nous avons jugé intéressant de faire une étude épidémiologique sur la brûlure par flamme de diluant (BFD) au centre national des brûlés (CNB) du CHU Ibn-Rochd de Casablanca. Ce travail a été réalisé sur une période de 10 mois (septembre 2007/juin 2008). Le but du travail est de montrer les caractéristiques de ce type de brûlures pour les prévenir et ce par l'information sur le diluant, produit causant ces brûlures, et ses différents dangers, la brûlure notamment. Durant cette période, nous avons colligé 17 cas de BFD sur un total de 356 patients admis au CNB pour brûlures aiguës toute étiologie confondue. La moyenne d'age des patients concernés est de 32 ans. Ils sont presque tous de sexe masculin (16 hommes/1 femme) et ont des antécédents de toxicomanie et/ou de délinquance. Tous nos patients sont de bas niveau socio-économique et habitent dans des bidonvilles pour la plupart. La brûlure est souvent secondaire à une agression dans la rue (92% des cas). Concernant les caractéristiques de la brûlure, la surface cutanée brûlée moyenne est de 23%; elle est souvent profonde et siège surtout au niveau des membres supérieurs et du tronc. PMID:21991179

  20. Insights into ParB spreading from the complex structure of Spo0J and parS.

    Science.gov (United States)

    Chen, Bo-Wei; Lin, Ming-Hsing; Chu, Chen-Hsi; Hsu, Chia-En; Sun, Yuh-Ju

    2015-05-26

    Spo0J (stage 0 sporulation protein J, a member of the ParB superfamily) is an essential component of the ParABS (partition system of ParA, ParB, and parS)-related bacterial chromosome segregation system. ParB (partition protein B) and its regulatory protein, ParA, act cooperatively through parS (partition S) DNA to facilitate chromosome segregation. ParB binds to chromosomal DNA at specific parS sites as well as the neighboring nonspecific DNA sites. Various ParB molecules can associate together and spread along the chromosomal DNA. ParB oligomer and parS DNA interact together to form a high-order nucleoprotein that is required for the loading of the structural maintenance of chromosomes proteins onto the chromosome for chromosomal DNA condensation. In this report, we characterized the binding of parS and Spo0J from Helicobacter pylori (HpSpo0J) and solved the crystal structure of the C-terminal domain truncated protein (Ct-HpSpo0J)-parS complex. Ct-HpSpo0J folds into an elongated structure that includes a flexible N-terminal domain for protein-protein interaction and a conserved DNA-binding domain for parS binding. Two Ct-HpSpo0J molecules bind with one parS. Ct-HpSpo0J interacts vertically and horizontally with its neighbors through the N-terminal domain to form an oligomer. These adjacent and transverse interactions are accomplished via a highly conserved arginine patch: RRLR. These interactions might be needed for molecular assembly of a high-order nucleoprotein complex and for ParB spreading. A structural model for ParB spreading and chromosomal DNA condensation that lead to chromosome segregation is proposed.

  1. 77 FR 74668 - Compliance Policy Guide; Radiofrequency Identification Feasibility Studies and Pilot Programs for...

    Science.gov (United States)

    2012-12-17

    ... ``Radiofrequency Identification (RFID) Feasibility Studies and Pilot Programs for Drugs'' to December 31, 2014. FOR... HUMAN SERVICES Food and Drug Administration Compliance Policy Guide; Radiofrequency Identification... 67360), FDA announced the ] availability of CPG Sec. 400.210 entitled ``Radiofrequency Identification...

  2. 75 FR 80827 - Compliance Policy Guide; Radiofrequency Identification Feasibility Studies and Pilot Programs for...

    Science.gov (United States)

    2010-12-23

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

  3. Aerosols produced by evaporation of a uranium wire; Aerosols produits par evaporation d'un fil d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Morel, C. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-03-01

    This work is devoted to the study of the aerosols formed when an uranium wire is evaporated in a normal or rarefied atmosphere, either with or without a drying agent. The heating of the wire can be either fast or slow. The first part is a study of aerosol production apparatus and of methods of measuring the aerosol. The second part presents the results obtained with various aerosols: the particles produced by the wire are less than one micron; during rapid heating, the granulometric distribution of the aerosol obeys a log-normal law; during slow heating, the distribution has two modes: one near 0.05 micron, the other close to 0.01 micron. (author) [French] Ce travail est consacre a l'etude des aerosols formes lors de l'evaporation d un fil d'uranium en atmosphere normale ou rarefiee en presence ou non de dessechant. Le chauffage du fil peut etre rapide ou lent. La premiere partie est une etude des appareils de production et des methodes de mesures de l'aerosol. La seconde partie consigne les resultats obtenus sur les differents aerosols: les particules emises par le fil sont inferieures au micron; lors d'un chauffage rapide, la repartition granulometrique de l'aerosol suit une loi log-normale; lors d un chauffage lent, la repartition presente deux modes: l'un voisin de 0.05 micron, l'autre voisin de 0.01 micron. (auteur)

  4. Radiofrequency and microwave interactions between biomolecular systems.

    Science.gov (United States)

    Kučera, Ondřej; Cifra, Michal

    2016-01-01

    The knowledge of mechanisms underlying interactions between biological systems, be they biomacromolecules or living cells, is crucial for understanding physiology, as well as for possible prevention, diagnostics and therapy of pathological states. Apart from known chemical and direct contact electrical signaling pathways, electromagnetic phenomena were proposed by some authors to mediate non-chemical interactions on both intracellular and intercellular levels. Here, we discuss perspectives in the research of nanoscale electromagnetic interactions between biosystems on radiofrequency and microwave wavelengths. Based on our analysis, the main perspectives are in (i) the micro and nanoscale characterization of both passive and active radiofrequency properties of biomacromolecules and cells, (ii) experimental determination of viscous damping of biomacromolecule structural vibrations and (iii) detailed analysis of energetic circumstances of electromagnetic interactions between oscillating polar biomacromolecules. Current cutting-edge nanotechnology and computational techniques start to enable such studies so we can expect new interesting insights into electromagnetic aspects of molecular biophysics of cell signaling.

  5. 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.

  6. Percutaneous radiofrequency thermal lumbar sympathectomy and its clinical use

    OpenAIRE

    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, 1971; Rosomoff, 1966, Sweet 1974, Uematsu, 1974). Apart from the report by Pernak (1985) no other clinical studies concerning the use of the radiofrequency electrocoagulation technique for denervation...

  7. Standard guidelines for electrosurgery with radiofrequency current

    OpenAIRE

    Mutalik Sharad

    2009-01-01

    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, ...

  8. Box Lesion with Single Radiofrequency Clamp.

    Science.gov (United States)

    Shaikhrezai, Kasra; Spadaccio, Cristiano; Hunter, Steven

    2017-04-12

    We introduce a maneuver to perform the box lesion as a part of Cox maze IV procedure with single radiofrequency clamp. The maneuver entails engaging the right pulmonary veins with the clamp, then advancing the clamp jaws underneath the superior vena cava through the transverse sinus to include the roof and the left pulmonary veins in the clamp. We regularly use this technique for box lesion with desirable transmurality. Georg Thieme Verlag KG Stuttgart · New York.

  9. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

    Energy Technology Data Exchange (ETDEWEB)

    Majdalany, Bill S., E-mail: bmajdala@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States); Elliott, Eric D., E-mail: eric.elliott@osumc.edu [The Ohio State University Wexner Medical Center, Division of Interventional Radiology, Department of Radiology (United States); Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu; Hanje, A. James, E-mail: James.Hanje@osumc.edu [The Ohio State University Wexner Medical Center, Division of Gastroenterology and Hepatology, Department of Medicine (United States); Saad, Wael E. A., E-mail: wsaad@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States)

    2016-07-15

    Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

  10. 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.

  11. Datation par thermoluminescence

    Directory of Open Access Journals (Sweden)

    1976-01-01

    Full Text Available Depuis 1953, de nombreux chercheurs se sont intéressés à la datation par thermoluminescence de minéraux anciennement brûlés ou cuits. Dans ce travail, après avoir rappelé quelques principes physiques de la thermoluminescence, on présente cette méthode de datation en mettant l'accent sur le mécanisme thermoluminescent dans une poterie. Ainsi la dose d'irradiation reçue par le matériau étant proportionnelle au temps écoulé depuis le 'zéro archéologique', il est possible de déterminer 'la dose archéologique' et d'en déduire l'âge de l'échantillon après avoir calculé la dose d'irradiation annuelle. La réalisation pratique d'un tel ensemble de mesure est cependant très ardue. Dans un prochain article, E. A. Decamps et A. Roman montreront des résultats relatifs à la thermoluminescence d'échantillons de quartz naturels, purs et dopés et la mise au point d'une nouvelle méthode de datation. Desde 1953, muchos investigadores se han interesado en la datación por termoluminiscencia de minerales antiguamente quemados o cocidos. Dentro de este trabajo, luego de haber recordado algunos principios físicos de la termoluminiscencia, se presenta este método de datación poniendo mayor atención en el mecanismo termoluminescente en una vasija de metal o de barro. Siendo proporcional la dosis de irradiación recibida al tiempo transcurrido desde el 'cero arqueológico', es posible determinar 'la dosis arqueológica', y deducir la edad de la muestra luego de haber calculado la dosis de irradiación anual. La realización práctica de un trabajo de tal dimensión es sin embargo muy ardua. En un próximo artículo, E. A. Decamps y A. Román presentarán los resultados relativos a la termoluminiscencia de muestras de cuarzo naturales, puras y dopadas y la elaboración de un nuevo método de datación. Since 1953, a number of scientists have been concerned with the use of thermoluminescence for the dating of burned or fired minerals

  12. Elusloom lennukiga puhkusele / Inge Parring

    Index Scriptorium Estoniae

    Parring, Inge

    2003-01-01

    Ilmunud ka: Delovõje Vedomosti 1. okt. lk. 13. Air Cargo Estonia/ACE Logisticsi müügijuht Inge Parring tutvustab elusloomade transpordivõimalusi. Vt. samas: Loomade transportimiseks vajalikud dokumendid

  13. suPAR: the molecular crystal ball

    DEFF Research Database (Denmark)

    Thunø, Maria; Macho, Betina; Eugen-Olsen, Jesper

    2009-01-01

    soluble urokinase Plasminogen Activator Receptor (suPAR) levels reflect inflammation and elevated suPAR levels are found in several infectious diseases and cancer. suPAR exists in three forms; suPAR(I-III), suPAR(II-III) and suPAR(I) which show different properties due to structural differences. ...... in inflammation and pathogenic processes. We focus on the molecular mechanisms of the suPAR fragments and the link to the inflammatory process,as this could lead to medical applications in infectious and pathological conditions........ Studies suggest that full-length suPAR is a regulator of uPAR/uPA by actingas uPA-scavenger, whereas the cleaved suPAR(II-III) act as a chemotactic agent promoting the immune response via the SRSRY sequence in the linker-region. This review focus on the various suPAR fragments and their involvement...

  14. Immunopathogenic Background of Pars Planitis.

    Science.gov (United States)

    Przeździecka-Dołyk, Joanna; Węgrzyn, Agnieszka; Turno-Kręcicka, Anna; Misiuk-Hojło, Marta

    2016-04-01

    Pars planitis is defined as an intermediate uveitis of unknown background of systemic disease with characteristic formations such as vitreous snowballs, snowbanks and changes in peripheral retina. The incidence of pars planitis varies 2.4-15.4 % of the uveitis patients. The pathogenesis of the disease is to be determined in future. Clinical and histopathological findings suggest an autoimmune etiology, most likely as a reaction to endogenous antigen of unknown source, with T cells predominant in both vitreous and pars plana infiltrations. T cells subsets play an important role as a memory-effector peripheral cell. Snowbanks are formed as an effect of post inflammatory glial proliferation of fibrous astrocytes. There is also a genetic predisposition for pars planitis by human leukocyte antigen and several other genes. A coexistence of multiple sclerosis and optic neuritis has been described in numerous studies. Epiretinal membrane, cataract, cystoid macular edema, retinal detachment, retinal vasculitis, neovascularization, vitreous peripheral traction, peripheral hole formation, vitreous hemorrhage, disc edema are common complications observed in pars planitis. There is a need to expand the knowledge of the pathogenic and immunologic background of the pars planitis to create an accurate pharmacological treatment.

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

    African Journals Online (AJOL)

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

  16. Current situation on radiofrequency ablation of hepatic hemangioma

    OpenAIRE

    Zou, Hua

    2013-01-01

    The recent progress in radiofrequency ablation (RFA) of hepatic hemangioma was reviewed, with a focus on radiofrequency electrodes, treatment modalities, complications, and prevention strategies. The foundation for the standardization of RFA of hepatic hemangioma was laid. The standardization of RFA will help to promote its clinical application and development as an important minimally invasive technique for hepatic hemangioma.

  17. Current situation on radiofrequency ablation of hepatic hemangioma

    Directory of Open Access Journals (Sweden)

    ZOU Hua

    2013-08-01

    Full Text Available The recent progress in radiofrequency ablation (RFA of hepatic hemangioma was reviewed, with a focus on radiofrequency electrodes, treatment modalities, complications, and prevention strategies. The foundation for the standardization of RFA of hepatic hemangioma was laid. The standardization of RFA will help to promote its clinical application and development as an important minimally invasive technique for hepatic hemangioma.

  18. 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.)

  19. 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...

  20. 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....

  1. Ultracold atoms in multiple radio-frequency dressed adiabatic potentials

    Science.gov (United States)

    Harte, T. L.; Bentine, E.; Luksch, K.; Barker, A. J.; Trypogeorgos, D.; Yuen, B.; Foot, C. J.

    2018-01-01

    We present the first experimental demonstration of a multiple radio-frequency dressed potential for the configurable magnetic confinement of ultracold atoms. We load cold 87Rb atoms into a double-well potential with an adjustable barrier height, formed by three radio-frequencies applied to atoms in a static quadrupole magnetic field. Our multiple radio-frequency approach gives precise control over the double-well characteristics, including the depth of individual wells and the height of the barrier, and enables reliable transfer of atoms between the available trapping geometries. We characterize the multiple radio-frequency dressed system using radio-frequency spectroscopy, finding good agreement with the eigenvalues numerically calculated using Floquet theory. This method creates trapping potentials that can be reconfigured by changing the amplitudes, polarizations, and frequencies of the applied dressing fields and easily extended with additional dressing frequencies.

  2. Carbon nanotube radio-frequency electronics

    Science.gov (United States)

    Zhong, Donglai; Zhang, Zhiyong; Peng, Lian-Mao

    2017-05-01

    Carbon nanotube (CNT) is considered a promising material for radio-frequency (RF) applications, owing to its high carrier mobility and saturated drift velocity, as well as ultra-small intrinsic gate capacitance. Here, we review progress on CNT-based devices and integrated circuits for RF applications, including theoretical projection of RF performance of CNT-based devices, preparation of CNT materials, fabrication, optimization of RF field-effect transistors (FETs) structures, and ambipolar FET-based RF applications, and we outline challenges and prospects of CNT-based RF applications.

  3. Radiofrequency Ablation Complicated by Skin Burn

    Science.gov (United States)

    Huffman, S.D.; Huffman, N.P.; Lewandowski, Robert J.; Brown, Daniel B.

    2011-01-01

    Radiofrequency (RF) ablation has been increasingly utilized as a minimally invasive treatment for primary and metastatic liver tumors, as well as tumors in the kidneys, bones, and adrenal glands. The development of high-current RF ablation has subsequently led to an increased risk of thermal skin injuries at the grounding pad site. The incidence of skin burns in recent studies ranges from 0.1–3.2% for severe skin burns (second-/third-degree), and from 5–33% for first-degree burns.1–3 PMID:22654258

  4. Active stabilization of ion trap radiofrequency potentials

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K. G.; Wong-Campos, J. D.; Restelli, A.; Landsman, K. A.; Neyenhuis, B.; Mizrahi, J.; Monroe, C. [Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742 (United States)

    2016-05-15

    We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.

  5. Seizure Freedom After Limited Hippocampal Radiofrequency Thermocoagulation.

    Science.gov (United States)

    Li, Han-Tao; Lee, Ching-Yi; Lim, Siew-Na; Chang, Chun-Wei; Lee, Shih-Tseng; Wu, Tony

    2016-12-01

    Surgical interventions are often used for freedom from seizure in patients with drug-resistant mesial temporal lobe epilepsy. A patient with seizure foci in the left mesiotemporal region underwent limited-size stereotactic radiofrequency thermocoagulation (RF-TC) over the left hippocampus. A 37-year-old woman with febrile convulsion in her childhood was admitted to our neurologic department with complex partial seizure with secondary generalization. Electroencephalography showed epileptogenic focus mainly from the left mesiotemporal region, and magnetic resonance imaging confirmed a left hippocampal atrophy. Because of failure to control seizure after use of several antiepileptic drugs, drug-resistant mesial temporal lobe epilepsy was diagnosed. RF-TC was done in the left hippocampus. Unique features of our technique include intraoperative electroencephalography recordings directly from electrodes on the left hippocampus, an aura sensation provoked during the low-temperature test thermocoagulation, and therapeutic thermocoagulation performed via a Radionics radiofrequency lead. In the 16-week period following the surgery, the patient experienced no seizure attacks and no significant postoperative adverse effects or memory impairments. Compared with other reports using RF-TC, our case demonstrates a 1-step minimally invasive surgery that reduces hippocampal volume loss, shortens the length of hospital stay, decreases the occurrence of postoperative infection, and achieves good outcomes for epilepsy control. Favorable seizure control was achieved with minimally invasive RF-TC. Further use of this technique is warranted in cases of drug-resistant mesial temporal lobe epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. 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.

  7. Designing Tone Reservation PAR Reduction

    Directory of Open Access Journals (Sweden)

    Johansson Albin

    2006-01-01

    Full Text Available Tone reservation peak-to-average (PAR ratio reduction is an established area when it comes to bringing down signal peaks in multicarrier (DMT or OFDM systems. When designing such a system, some questions often arise about PAR reduction. Is it worth the effort? How much can it give? How much does it give depending on the parameter choices? With this paper, we attempt to answer these questions without resolving to extensive simulations for every system and every parameter choice. From a specification of the allowed spectrum, for instance prescribed by a standard, including a PSD-mask and a number of tones, we analytically predict achievable PAR levels, and thus implicitly suggest parameter choices. We use the ADSL2 and ADSL2+ systems as design examples.

  8. Increased ParB level affects expression of stress response, adaptation and virulence operons and potentiates repression of promoters adjacent to the high affinity binding sites parS3 and parS4 in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Adam Kawalek

    Full Text Available Similarly to its homologs in other bacteria, Pseudomonas aeruginosa partitioning protein ParB facilitates segregation of newly replicated chromosomes. Lack of ParB is not lethal but results in increased frequency of anucleate cells production, longer division time, cell elongation, altered colony morphology and defective swarming and swimming motility. Unlike in other bacteria, inactivation of parB leads to major changes of the transcriptome, suggesting that, directly or indirectly, ParB plays a role in regulation of gene expression in this organism. ParB overproduction affects growth rate, cell division and motility in a similar way as ParB deficiency. To identify primary ParB targets, here we analysed the impact of a slight increase in ParB level on P. aeruginosa transcriptome. ParB excess, which does not cause changes in growth rate and chromosome segregation, significantly alters the expression of 176 loci. Most notably, the mRNA level of genes adjacent to high affinity ParB binding sites parS1-4 close to oriC is reduced. Conversely, in cells lacking either parB or functional parS sequences the orfs adjacent to parS3 and parS4 are upregulated, indicating that direct ParB- parS3/parS4 interactions repress the transcription in this region. In addition, increased ParB level brings about repression or activation of numerous genes including several transcriptional regulators involved in SOS response, virulence and adaptation. Overall, our data support the role of partitioning protein ParB as a transcriptional regulator in Pseudomonas aeruginosa.

  9. 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.

  10. Optical generation of radio-frequency power

    Energy Technology Data Exchange (ETDEWEB)

    Hietala, V.M.; Vawter, G.A.; Brennan, T.M.; Hammons, B.E.; Meyer, W.J.

    1994-11-01

    An optical technique for high-power radio-frequency (RF) signal generation is described. The technique uses a unique photodetector based on a traveling-wave design driven by an appropriately modulated light source. The traveling-wave photodetector (TWPD) exhibits simultaneously a theoretical quantum efficiency approaching 100 % and a very large electrical bandwidth. Additionally, it is capable of dissipating the high-power levels required for the RF generation technique. The modulated light source is formed by either the beating together of two lasers or by the direct modulation of a light source. A system example is given which predicts RF power levels of 100`s of mW`s at millimeter wave frequencies with a theoretical ``wall-plug`` efficiency approaching 34%.

  11. 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...

  12. Transcutaneous temperature controlled radiofrequency for orgasmic dysfunction

    Science.gov (United States)

    2016-01-01

    Background and Objectives To evaluate the safety, tolerability, and clinical efficacy of transcutaneous temperature controlled radiofrequency (TTCRF) on vulvovaginal tissue for orgasmic dysfunction. Study Design/Materials and Methods Subjects included 25 sexually active women, ages 21–65, with self‐reported difficulty in achieving orgasms during sex (anorgasmic or slow‐to‐orgasm). Each patient received three sessions at intervals of about 1 month. Treatment was performed using a slim S‐shaped probe with a stamp‐sized metal radiofrequency emitter on one surface of the tip (25 minutes total time on average). External treatments covered the labia majora and minora, lower mons pubis, perineal body, clitoral hood, and clitoris. Full length treatment of the vagina with concentration on the anterior wall was performed. Tissue temperature during therapy was elevated to and maintained between 40°C and 45°C. No anesthesia was required. After treatment, patients immediately resumed normal activities, including sex. Results Twenty‐three of 25 patients reported an average reduction in time to orgasm of 50%. Patients also noted significant vaginal tightening effects, increased vaginal moisture, and improved vulvar and clitoral sensitivity. All anorgasmic patients reported the ability to achieve orgasms. Two patients had minimal response. Conclusion TTCRF is an effective non‐hormonal, non‐surgical option for women having difficulty achieving orgasm. Treatment also has visible tightening effects on feminine tissues and appears to increase local blood flow, resulting in increased vaginal tightness and moisture. Improved appearance and friction resulted in improved confidence and reduced performance anxiety. Lasers Surg. Med. 48:641–645, 2016. © 2016 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc. PMID:27197701

  13. Burner redesign for the reduction of the unburned particulate emission in thermal power stations of Comision Federal de Electricidad; Rediseno de quemadores para la reduccion de la emision de particulas inquemadas en centrales termicas de la Comisionon Federal de Electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Huerta Espino, Mario; Espipnoza Garza, Jesus; Mani Gonzalez, Alejandro; Giles Alarcon, Armando; Pena Garcia, Adriana; Albarran Sanchez, Irma L.; Mendez Aranda, Angel [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    In the presence of the increasing demand for reaching higher efficiencies and a smaller production of polluting emissions in combustion systems, studies focused to the optimization of the present designs of burners are required. The Comision Federal de Electricidad (CFE) and the Instituto de Investigaciones Electricas (IIE) have established a project that contemplates the redesign of burners in ten of its units of thermoelectric generation. In this work the redesign of the flame stabilizer or diffuser for the reduction of the unburned particulate emission is explained. The results of the modeling of a burner of rotational flow of steam generators of the CFE are shown, as well as the graphs of the contours of the recirculation zone generated by each diffuser without combustion and a figure of the velocity profile that is generated in front of the diffuser. In agreement with the results obtained in the aerodynamic evaluation of frontal burners of rotational flow, it is possible to established that the characteristics of the recirculation zone, generated by this type of burners, are related to geometric parameters of the diffuser that identify with the number of turns and the pressure drop, where it is necessary to look for designs that improve the conditions of the mixing process and combustion in the burner. [Spanish] Ante la creciente demanda por alcanzar mayores eficiencias y una menor produccion de emisiones contaminantes en sistemas de combustion, se requieren estudios enfocados a la optimizacion de los disenos actuales de quemadores. La Comision Federal de Electricidad (CFE) y el Instituto de Investigaciones Electricas (IIE) han establecido un proyecto que contempla el rediseno de quemadores en diez de sus unidades de generacion termoelectrica. En este trabajo se explica el rediseno del estabilizador de flama o difusor para la reduccion de la emision de particulas inquemadas. Se muestran los resultados de la modelacion de un quemador de flujo rotacional de

  14. Effective treatment of chronic radiation proctitis using radiofrequency ablation

    National Research Council Canada - National Science Library

    Chao Zhou; Adler, Desmond C; Becker, Laren; Yu Chen; Tsai, Tsung-Han; Figueiredo, Marisa; Schmitt, Joseph M; Fujimoto, James G; Mashimo, Hiroshi

    2009-01-01

    .... Radiofrequency ablation (RFA) has been successful for mucosal ablation in the esophagus. Here we report the efficacy of RFA with the BarRx Halo90 system in three patients with bleeding from chronic radiation proctitis...

  15. Computer Aided Design of Radiofrequency and Microwave Circuits

    Directory of Open Access Journals (Sweden)

    J. Tomandl

    1993-04-01

    Full Text Available Radiofrequency and microwave CAD computer programs enabling for signal and yield analysis and circuit optimization have been developed. Program is used both in circuit design and student education.

  16. 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.)

  17. Lymphangioma Circumscriptum (Microcystic Lymphatic Malformation): Palliative Coagulation Using Radiofrequency Current

    Science.gov (United States)

    Omprakash HM; Rajendran SC

    2008-01-01

    Lymphangioma circumscriptum (LC, microcystic lymphatic malformation), a hamartomatous lymphatic malformation, is a difficult condition to treat. Different treatments such as surgical excision, lasers, sclerotherapy etc have all been tried with varying success. We report here the efficacy of a radiofrequency current in two patients with lymphangioma circumscriptum. The radiofrequency technique is a safe, economical, and commonly available technique for the treatment of LC; the surgical safety and outcome were satisfactory in our patients. PMID:20300350

  18. Lymphangioma Circumscriptum (Microcystic Lymphatic Malformation): Palliative Coagulation Using Radiofrequency Current

    OpenAIRE

    Omprakash HM,; Rajendran SC,

    2008-01-01

    Lymphangioma circumscriptum (LC, microcystic lymphatic malformation), a hamartomatous lymphatic malformation, is a difficult condition to treat. Different treatments such as surgical excision, lasers, sclerotherapy etc have all been tried with varying success. We report here the efficacy of a radiofrequency current in two patients with lymphangioma circumscriptum. The radiofrequency technique is a safe, economical, and commonly available technique for the treatment of LC; the surgical safety ...

  19. 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 treatment. Fractional radiofrequency microneedling is a safe and effective treatment for acne vulgaris. © 2014 Japanese Dermatological Association.

  20. Stereo-EEG-guided radiofrequency thermocoagulations.

    Science.gov (United States)

    Cossu, Massimo; Cardinale, Francesco; Casaceli, Giuseppe; Castana, Laura; Consales, Alessandro; D'Orio, Piergiorgio; Lo Russo, Giorgio

    2017-04-01

    The rationale and the surgical technique of stereo-electroencephalography (SEEG)-guided radiofrequency thermocoagulation (RF-TC) in the epileptogenic zone (EZ) of patients with difficult-to-treat focal epilepsy are described in this article. The application of the technique in pediatric patients is also detailed. Stereotactic ablative procedures by RF-TC have been employed in the treatment of epilepsy since the middle of the last century. This treatment option has gained new popularity in recent decades, mainly because of the availability of modern imaging techniques, which allow accurate targeting of intracerebral epileptogenic structures. SEEG is a powerful tool for identifying the EZ in the most challenging cases of focal epilepsy by recording electrical activity with tailored stereotactic implantation of multilead intracerebral electrodes. The same recording electrodes may be used to place thermocoagulative lesions in the EZ, following the indications provided by intracerebral monitoring. The technical details of SEEG implantation and of SEEG-guided RF-TC are described herein, with special attention to the employment of the procedure in pediatric cases. SEEG-guided RF-TC offers a potential therapeutic option based on robust electroclinical evidence with acceptable risks and costs. The procedure may be performed in patients who, according to SEEG recording, are not eligible for resective surgery, and it may be an alternative to resective surgery in a small subset of operable patients. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  1. 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.

  2. Size and geometry of hepatic radiofrequency lesions.

    Science.gov (United States)

    Mulier, S; Ni, Y; Miao, Y; Rosière, A; Khoury, A; Marchal, G; Michel, L

    2003-12-01

    To report and compare the size and geometry of hepatic radiofrequency (RF) lesions using the currently available commercial devices. A literature search was carried out for the period from January 1st 1990 to June 15th 2003. The commercial suppliers were asked to provide all available data. For each electrode and protocol, size and geometry of single-cycle thermal lesions were registered. No information at all on size and geometry of the inducible lesions was available for 17 of the 28 current commercial electrodes. Many descriptions of RF lesions are limited to the mean transverse diameter. With normal blood flow, diameter of lesions is often smaller than suggested by the length of the electrode tip or the diameter of the deployed prongs. Lesions are rarely perfect spheres but either ellipses or flattened spheres. Distortion of the RF lesion by nearby blood vessels is very common. Fusion of thermal zones between prongs of expandable electrodes can be incomplete. Blood flow interruption using a Pringle maneuver yields larger lesions that are less distorted and more complete. There is insufficient experimental data for many electrodes that are currently used in patients. RF companies should provide these data before releasing electrodes for use. For those electrodes for which data exist, coagulation lesions are often smaller, less spherical, less complete and less regular than generally presumed. Accurate knowledge of size and geometry of RF lesions is crucial to prevent local recurrence.

  3. Radiofrequency heating pathways for gold nanoparticles.

    Science.gov (United States)

    Collins, C B; McCoy, R S; Ackerson, B J; Collins, G J; Ackerson, C J

    2014-08-07

    This feature article reviews the thermal dissipation of nanoscopic gold under radiofrequency (RF) irradiation. It also presents previously unpublished data addressing obscure aspects of this phenomenon. While applications in biology motivated initial investigation of RF heating of gold nanoparticles, recent controversy concerning whether thermal effects can be attributed to nanoscopic gold highlight the need to understand the involved mechanism or mechanisms of heating. Both the nature of the particle and the nature of the RF field influence heating. Aspects of nanoparticle chemistry which may affect thermal dissipation include the hydrodynamic diameter of the particle, the oxidation state and related magnetism of the core, and the chemical nature of the ligand shell. Aspects of RF which may affect thermal dissipation include power, frequency and antenna designs that emphasize relative strength of magnetic or electric fields. These nanoparticle and RF properties are analysed in the context of three heating mechanisms proposed to explain gold nanoparticle heating in an RF field. This article also makes a critical analysis of the existing literature in the context of the nanoparticle preparations, RF structure, and suggested mechanisms in previously reported experiments.

  4. 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.

  5. Radiofrequency treatments: what can we expect?

    Science.gov (United States)

    Avantaggiato, A; Bertuzzi, G; Addonisio, T; Iannucci, G; Vitiello, U; Carinci, F

    2016-01-01

    Among non-ablative procedures in aesthetic medicine, the radiofrequency (RF) is one of the most popular for the treatment of face and body skin laxity. It can be classified as a physical bio-stimulation that produces a temperature increase on biological structures, using electromagnetic waves. The term encompasses devices having substantial differences in energy, wavelengths, handpieces dimension and structure. Moreover, for some of these, the protocols are only partially defined. The aim of this short review is to clarify some aspecst of the RF therapy starting from the physics, passing through the mechanism of action and finally, with the most suitable protocols. Contrary to mechanic waves, electromagnetic waves, physics are always transversal to the impulse and this leads to the different energy distribution in capacitive (monopolar) or resistive (bi- or multi-polar) applications. The thermal damage as therapeutic effect is a postulate that needs to be discussed and the same is true for the terms “non-surgical” and “non-ablative”, often recurrent in the scientific literature. Protocols must be optimized according to the machine and the patient, keeping in mind the possibilities of biostimulation in terms of immediate improvement and of long lasting investment in skin rejuvenation. It is mandatory to understand the possibilities and limitations of each device to perform useful, safe and correct medical treatments.

  6. Radiofrequency Heating Pathways for Gold Nanoparticles

    Science.gov (United States)

    Collins, C. B.; McCoy, R. S.; Ackerson, B. J.; Collins, G. J.

    2015-01-01

    This feature article reviews the thermal dissipation of nanoscopic gold under radiofrequency (RF) irradiation. It also presents previously unpublished data addressing obscure aspects of this phenomenon. While applications in biology motivated initial investigation of RF heating of gold nanoparticles, recent controversy concerning whether thermal effects can be attributed to nanoscopic gold highlight the need to understand the involved mechanism or mechanisms of heating. Both the nature of the particle and the nature of the RF field influence heating. Aspects of nanoparticle chemistry and physics, including the hydrodynamic diameter of the particle, the oxidation state and related magnetism of the core, and the chemical nature of the ligand shell may all strongly influence to what extent a nanoparticle heats in an RF field. Aspects of RF include: power, frequency and antenna designs that emphasize relative strength of magnetic or electric fields, and also influence the extent to which a gold nanoparticle heats in RF. These nanoparticle and RF properties are analysed in the context of three heating mechanisms proposed to explain gold nanoparticle heating in an RF field. This article also makes a critical analysis of the existing literature in the context of the nanoparticle preparations, RF structure, and suggested mechanisms in previously reported experiments. PMID:24962620

  7. PAR-1 and PAR-2 Expression Is Enhanced in Inflamed Odontoblast Cells.

    Science.gov (United States)

    Alvarez, M M P; Moura, G E; Machado, M F M; Viana, G M; de Souza Costa, C A; Tjäderhane, L; Nader, H B; Tersariol, I L S; Nascimento, F D

    2017-12-01

    Protease-activated receptors (PARs) are G protein-coupled receptors, which are activated by proteolytical cleavage of the amino-terminus and act as sensors for extracellular proteases. We hypothesized that PAR-1 and PAR-2 can be modulated by inflammatory stimulus in human dental pulp cells. PAR-1 and PAR-2 gene expression in human pulp tissue and MDPC-23 cells were analyzed by quantitative polymerase chain reaction. Monoclonal PAR-1 and PAR-2 antibodies were used to investigate the cellular expression of these receptors using Western blot, flow cytometry, and confocal microscopy in MDPC-23 cells. Immunofluorescence assays of human intact and carious teeth were performed to assess the presence of PAR-1 and PAR-2 in the dentin-pulp complex. The results show for the first time that human odontoblasts and MDPC-23 cells constitutively express PAR-1 and PAR-2. PAR-2 activation increased significantly the messenger RNA expression of matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and MMP-14 in MDPC-23 cells ( P < 0.05), while the expression of these enzymes decreased significantly in the PAR-1 agonist group ( P < 0.05). The high-performance liquid chromatography and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis showed the presence of MMP-13 activity cleaving PAR-1 at specific, noncanonical site TLDPRS42↓F43LL in human dental pulp tissues. Also, we detected a presence of a trypsin-like activity cleaving PAR-2 at canonical site SKGR20↓S21LIGRL in pulp tissues. Confocal microscopy analysis of human dentin-pulp complex showed intense positive staining of PAR-1 and PAR-2 in the odontoblast processes in dentinal tubules of carious teeth compared to intact ones. The present results support the hypothesis of activation of the upregulated PAR-1 and PAR-2 by endogenous proteases abundant during the inflammatory response in dentin-pulp complex.

  8. Percutaneous Radiofrequency Ablation with Artificial Ascites for Hepatocellular Carcinoma in the Hepatic Dome: Initial Experience

    National Research Council Canada - National Science Library

    Rhim, Hyunchul; Lim, Hyo K; Kim, Young-sun; Choi, Dongil

    2008-01-01

    ...) in the hepatic dome. MATERIALS AND METHODS. Sonographically guided percutaneous radiofrequency ablation with artificial ascites was performed in 25 patients with 34 HCCs using an internally cooled electrode radiofrequency system...

  9. 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...

  10. Continuous Cavitation Designed for Enhancing Radiofrequency Ablation via a Special Radiofrequency Solidoid Vaporization Process.

    Science.gov (United States)

    Zhang, Kun; Li, Pei; Chen, Hangrong; Bo, Xiaowan; Li, Xiaolong; Xu, Huixiong

    2016-02-23

    Lowering power output and radiation time during radiofrequency (RF) ablation is still a challenge. Although it is documented that metal-based magnetothermal conversion and microbubbles-based inertial cavitation have been tried to overcome above issues, disputed toxicity and poor magnetothermal conversion efficiency for metal-based nanoparticles and violent but transient cavitation for microbubbles are inappropriate for enhancing RF ablation. In this report, a strategy, i.e., continuous cavitation, has been proposed, and solid menthol-encapsulated poly lactide-glycolide acid (PLGA) nanocapsules have been constructed, as a proof of concept, to validate the role of such a continuous cavitation principle in continuously enhancing RF ablation. The synthesized PLGA-based nanocapsules can respond to RF to generate menthol bubbles via distinctive radiofrequency solidoid vaporization (RSV) process, meanwhile significantly enhance ultrasound imaging for HeLa solid tumor, and further facilitate RF ablation via the continuous cavitation, as systematically demonstrated both in vitro and in vivo. Importantly, this RSV strategy can overcome drawbacks and limitations of acoustic droplet vaporization (ADV) and optical droplet vaporization (ODV), and will probably find broad applications in further cancer theranostics.

  11. Percutaneous extrapulmonary radiofrequency ablation for tumors in the hepatic dome.

    Science.gov (United States)

    Wang, Zhen-Yuan; Sun, Wen-Bing; Li, Ming-Ying; Zhang, Xiao-Xia; Ding, Xue-Mei

    2008-01-01

    This study aims to assess the feasibility of one lung ventilation and computed tomography-guided extrapulmonary percutaneous radiofrequency ablation for tumors in the hepatic dome. Eleven patients (10 men, 1 women; age range, 34-84 years) with 12 tumors in the hepatic dome were enrolled in the study after institutional review board approval and informed consent had been obtained. A 35F or 37F left-sided double-lumen endotracheal tube was intubated after general anesthesia was induced. The right lung is permitted to collapse, with selective left lungs ventilation. With CT monitoring, the RF electrode was inserted through the empty pleural space to the targeted tumor and radiofrequency ablation procedures were performed. The median operative time was 122 minutes. The median one lung ventilation time was 134 minutes. The procedures of one lung ventilation and percutaneous radiofrequency ablation were successfully performed. There was no bronchial intubation, one lung ventilation and percutaneous radiofrequency ablation related complications, excluding minor pleural effusions recovering without thoracentesis in 2 patients. Complete tumor necrosis was achieved in 10 patients (90.9%). One lung ventilation and computed tomography guided percutaneous extrapulmonary radiofrequency ablation for tumors in the hepatic dome appears to be useful and safe.

  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

    2015-02-06

    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. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. 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.

  14. Differences in clinical characteristics of fallopian canal dehiscence associated with pars flaccida and pars tensa cholesteatomas.

    Science.gov (United States)

    Shinnabe, Akihiro; Yamamoto, Hiroki; Hara, Mariko; Hasegawa, Masayo; Matsuzawa, Shingo; Kanazawa, Hiromi; Yoshida, Naohiro; Iino, Yukiko

    2014-08-01

    This study investigated the difference in clinical characteristics of fallopian canal dehiscence associated with pars flaccida and pars tensa cholesteatomas for the purpose of increasing the preoperative detectability of dehiscence. A total of 189 ears of patients 7-80 years of age (mean 42 years) with pars flaccida cholesteatoma and 63 ears of patients 9-84 years of age (mean 50 years) with pars tensa cholesteatoma were studied. All patients had undergone prior surgical management at our institution from January 2006 to April 2012. The incidence of fallopian canal dehiscence and its location were compared between pars flaccida and pars tensa cholesteatomas. Intraoperative findings of coexistent pathologies, including destruction of the stapes superstructure, labyrinthine fistula, and dural exposure, were compared between the dehiscence and no-dehiscence groups for the two types of cholesteatomas. The incidence of dehiscence was significantly higher in patients with pars tensa cholesteatoma (55.6 %) than in patients with pars flaccida cholesteatoma (26.5 %). Dehiscence located posterior to the cochleariform process occurred slightly more frequently in patients with pars tensa cholesteatoma than in those with pars flaccida cholesteatoma. In patients with pars flaccida cholesteatoma, labyrinthine fistulas and dural exposure were significantly more frequent in the dehiscence group than in the no-dehiscence group. Fallopian canal dehiscence is more frequent in patients with pars tensa cholesteatoma than in those with pars flaccida cholesteatoma. Especially in patients with pars flaccida cholesteatoma, paying special attention to these coexisting pathologies is important to increase preoperative detectability of dehiscence.

  15. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Science.gov (United States)

    2010-04-01

    ... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implantable radiofrequency transponder system for...

  16. Chemically Induced Radio-frequency Emission and Chemical Radiophysics

    Science.gov (United States)

    Buchachenko, Anatolii L.; Berdinskii, V. L.

    1983-01-01

    Chemical reactions involving free radicals can yield molecules with inverted populations of the nuclear Zeeman levels and able to store energy in the nuclear Zeeman reservoir. These molecules produce a radio-frequency electromagnetic field which induces radiative transitions between the Zeeman levels resulting in the conversion of the stored energy into radio-frequency emission from the molecules. The dependence of the recombination probability of the radicals on their spin state allows the elementary acts of radical reactions to be controlled by the application of radio-frequency electromagnetic fields ("chemical" radio receiver). The generation and reception of r.f. radiation in chemical reactions are the object of a new field of science: chemical radiophysics. 29 references.

  17. Immunity of electronic devices against radio-frequency electromagnetic fields

    Directory of Open Access Journals (Sweden)

    Urbancokova Hana

    2017-01-01

    Full Text Available One of the major types of electromagnetic interference, which affect electronic devices in their normal operation, is the interference with radio-frequency electromagnetic fields. This interference is generated by the mainly radio and television transmitters, industrial equipment and other transmitters and receivers in general use for communication. Testing of electromagnetic susceptibility of electronic devices on radiated radio-frequency electromagnetic field is governed by the basic standard IEC 61000-4-3 and the equipment under test are exposed to test electromagnetic fields with an intensity from 1 V/m to 30 V/m, the most often in the frequency range from 80 MHz to 2 GHz. The aim of this paper is to explain the issue of electromagnetic susceptibility and to present sample the electromagnetic immunity tests of the basic set of the intrusion and hold-up alarm system against the radio-frequency electromagnetic field according to the relevant electromagnetic compatibility standards.

  18. Radiofrequency amplifier based on a dc superconducting quantum interference device

    Science.gov (United States)

    Hilbert, Claude; Martinis, John M.; Clarke, John

    1986-01-01

    A low noise radiofrequency amplifier (10), using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID (11) and an input coil (12) are maintained at superconductivity temperatures in a superconducting shield (13), with the input coil (12) inductively coupled to the superconducting ring (17) of the dc SQUID (11). A radiofrequency signal from outside the shield (13) is applied to the input coil (12), and an amplified radiofrequency signal is developed across the dc SQUID ring (17) and transmitted to exteriorly of the shield (13). A power gain of 19.5.+-.0.5 dB has been achieved with a noise temperature of 1.0.+-.0.4 K. at a frequency of 100 MHz.

  19. Rapid growth of left atrial myxoma after radiofrequency ablation.

    Science.gov (United States)

    Rubio Alvarez, José; Martinez de Alegria, Anxo; Sierra Quiroga, Juan; Adrio Nazar, Belen; Rubio Taboada, Carola; Martinez Comendador, José Manuel

    2013-01-01

    Atrial myxoma is the most common benign tumor of the heart, but its appearance after radiofrequency ablation is very rare. We report a case in which an asymptomatic, rapidly growing cardiac myxoma arose in the left atrium after radiofrequency ablation. Two months after the procedure, cardiovascular magnetic resonance, performed to evaluate the right ventricular anatomy, revealed a 10 × 10-mm mass (assumed to be a thrombus) attached to the patient's left atrial septum. Three months later, transthoracic echocardiography revealed a larger mass, and the patient was diagnosed with myxoma. Two days later, a 20 × 20-mm myxoma weighing 37 g was excised. To our knowledge, the appearance of an atrial myxoma after radiofrequency ablation has been reported only once before. Whether tumor development is related to such ablation or is merely a coincidence is uncertain, but myxomas have developed after other instances of cardiac trauma.

  20. Radiofrequency ablation of the lateral palatal space for snoring

    Directory of Open Access Journals (Sweden)

    B. Tucker Woodson

    2017-06-01

    Full Text Available Objective: Pilot study to examine the effect of radiofrequency ablation (RFA of the lateral palatal fat pad in patients with socially-disruptive snoring. Method: Snoring outcomes and complications were compared between a group of patients with treated with RFA ablation of the lateral soft palate fat pad with or without inferior turbinate reduction (8 patients and another group undergoing inferior turbinate reduction alone (12 patients. Results: Snoring loudness and bothersomeness improved in the palate but not inferior turbinate group. Pain was mild and no major complications were observed. Conclusion: The study supports RFA ablation of the lateral palatal space as a potential low morbidity procedure for snoring. Keywords: Snoring, Radiofrequency, Somnoplasty, Radiofrequency ablation, Inferior turbinate reduction, Turbinoplasty

  1. 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.

  2. 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.

  3. Quantitative calibration of radiofrequency NMR Stark effects.

    Science.gov (United States)

    Tarasek, Matthew R; Kempf, James G

    2011-10-01

    Nuclear magnetic resonance (NMR) Stark responses can occur in quadrupolar nuclei for an electric field oscillating at twice the usual NMR frequency (2ω(0)). Calibration of responses to an applied E field is needed to establish nuclear spins as probes of native E fields within material and molecular systems. We present an improved approach and apparatus for accurate measurement of quadrupolar Stark effects. Updated values of C(14) (the response parameter in cubic crystals) were obtained for both (69)Ga and (75)As in GaAs. Keys to improvement include a modified implementation of voltage dividers to assess the 2ω(0) amplitude, |E|, and the stabilization of divider response by reduction of stray couplings in 2ω(0) circuitry. Finally, accuracy was enhanced by filtering sets of |E| through a linear response function that we established for the radiofrequency amplifier. Our approach is verified by two types of spectral results. Steady-state 2ω(0) excitation to presaturate NMR spectra yielded C(14) = (2.59 ± 0.06) × 10(12) m(-1) for (69)Ga at room-temperature and 14.1 T. For (75)As, we obtained (3.1 ± 0.1) × 10(12) m(-1). Both values reconcile with earlier results from 77 K and below 1 T, whereas current experiments are at room temperature and 14.1 T. Finally, we present results where few-microsecond pulses of the 2ω(0) field induced small (tens of Hz) changes in high-resolution NMR line shapes. There too, spectra collected vs |E| agree with the model for response, further establishing the validity of our protocols to specify |E|.

  4. 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.

  5. Endoscopic ultrasound-guided radiofrequency ablation of the pancreas

    DEFF Research Database (Denmark)

    Silviu, Ungureanu Bogdan; Daniel, Pirici; Claudiu, Mărgăritescu

    2015-01-01

    ultrasound (EUS)-guided radiofrequency ablation (RFA) probe through a 19G needle in order to achieve a desirable necrosis area in the pancreas. Radiofrequency ablation of the head of the pancreas was performed on 10 Yorkshire pigs with a weight between 25 kg and 35 kg and a length of 40-70 cm. Using an EUS...... analysis revealed increased values of amylase, alkaline phosphatase, and gamma-glutamyl transpeptidase on the 3rd day but a decrease on the 5th day. After necropsy and isolation of the pancreas, the ablated area was easily found, describing a solid necrosis. The pathological examination revealed...

  6. 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

  7. Deposition rate in modulated radio-frequency silane plasmas

    NARCIS (Netherlands)

    A.C.W. Biebericher,; Bezemer, J.; W.F. van der Weg,; W. J. Goedheer,

    2000-01-01

    Plasma-enhanced chemical-vapor deposition of amorphous silicon by a square-wave amplitude-modulated radio-frequency excitation has been studied by optical emission spectroscopy and plasma modeling. By the modulation, the deposition rate is increased or reduced, depending on the plasma parameters.

  8. 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

  9. Health Impacts of Radiofrequency Exposure From Mobile Phones ...

    African Journals Online (AJOL)

    the possible health risks associated with radiofrequency (RF) exposure from mobile phones and their transmitter base stations. A literature review by internet browsing, Medline and manual search was carried out. There are epidemiological evidences showing that low intensity pulsed radiation from mobile phones and base ...

  10. Health Impacts of Radiofrequency Exposure From Mobile Phones ...

    African Journals Online (AJOL)

    The widespread use of mobile phones and indiscriminate siting of transmitter base stations near residential buildings in our environment may have serious health impacts. This report attempts to investigate the possible health risks associated with radiofrequency (RF) exposure from mobile phones and their transmitter base ...

  11. Health Impacts Of Radiofrequency Exposure From Mobile Phone ...

    African Journals Online (AJOL)

    Background: The widespread use of mobile phones and indiscriminate siting of transmitter base stations near residential buildings in our environment may have serious health impacts. Objective: To investigate the possible health risks associated with radiofrequency (RF) exposure from mobile phones and other transmitter ...

  12. 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...

  13. 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...

  14. 77 FR 43535 - Grantee Codes for Certified Radiofrequency Equipment

    Science.gov (United States)

    2012-07-25

    ... COMMISSION 47 CFR Part 2 Grantee Codes for Certified Radiofrequency Equipment AGENCY: Federal Communications... continue to have new ones to assign to parties that wish to certify new equipment. DATES: Effective August....gov . Summary of the Order 1. The Commission operates an equipment authorization program for...

  15. Design studies of a high-current radiofrequency quadrupole for ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 74; Issue 2. Design studies of a high-current radiofrequency quadrupole for accelerator-driven systems programme ... We have followed the conventional design technique with slight modifications and compared that with the equipartitioned (EP) type of design.

  16. Effect of Mobile Phone Radiofrequency Electromagnetic Fields on ...

    African Journals Online (AJOL)

    olayemitoyin

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

  17. The ParB-parS Chromosome Segregation System Modulates Competence Development in Streptococcus pneumoniae.

    Science.gov (United States)

    Attaiech, Laetitia; Minnen, Anita; Kjos, Morten; Gruber, Stephan; Veening, Jan-Willem

    2015-06-30

    ParB proteins bind centromere-like DNA sequences called parS sites and are involved in plasmid and chromosome segregation in bacteria. We previously showed that the opportunistic human pathogen Streptococcus pneumoniae contains four parS sequences located close to the origin of replication which are bound by ParB. Using chromatin immunoprecipitation (ChIP), we found here that ParB spreads out from one of these parS sites, parS(-1.6°), for more than 5 kb and occupies the nearby comCDE operon, which drives competence development. Competence allows S. pneumoniae to take up DNA from its environment, thereby mediating horizontal gene transfer, and is also employed as a general stress response. Mutating parS(-1.6°) or deleting parB resulted in transcriptional up-regulation of comCDE and ssbB (a gene belonging to the competence regulon), demonstrating that ParB acts as a repressor of competence. However, genome-wide transcription analysis showed that ParB is not a global transcriptional regulator. Different factors, such as the composition of the growth medium and antibiotic-induced stress, can trigger the sensitive switch driving competence. This work shows that the ParB-parS chromosome segregation machinery also influences this developmental process. Streptococcus pneumoniae (pneumococcus) is an important human pathogen responsible for more than a million deaths each year. Like all other organisms, S. pneumoniae must be able to segregate its chromosomes properly. Not only is understanding the molecular mechanisms underlying chromosome segregation in S. pneumoniae therefore of fundamental importance, but also, this knowledge might offer new leads for ways to target this pathogen. Here, we identified a link between the pneumococcal chromosome segregation system and the competence-developmental system. Competence allows S. pneumoniae to take up and integrate exogenous DNA in its chromosome. This process plays a crucial role in successful adaptation to--and escape from

  18. ParAB Partition Dynamics in Firmicutes: Nucleoid Bound ParA Captures and Tethers ParB-Plasmid Complexes.

    Directory of Open Access Journals (Sweden)

    Virginia S Lioy

    Full Text Available In Firmicutes, small homodimeric ParA-like (δ2 and ParB-like (ω2 proteins, in concert with cis-acting plasmid-borne parS and the host chromosome, secure stable plasmid inheritance in a growing bacterial population. This study shows that (ω:YFP2 binding to parS facilitates plasmid clustering in the cytosol. (δ:GFP2 requires ATP binding but not hydrolysis to localize onto the cell's nucleoid as a fluorescent cloud. The interaction of (δ:CFP2 or δ2 bound to the nucleoid with (ω:YFP2 foci facilitates plasmid capture, from a very broad distribution, towards the nucleoid and plasmid pairing. parS-bound ω2 promotes redistribution of (δ:GFP2, leading to the dynamic release of (δ:GFP2 from the nucleoid, in a process favored by ATP hydrolysis and protein-protein interaction. (δD60A:GFP2, which binds but cannot hydrolyze ATP, also forms unstable complexes on the nucleoid. In the presence of ω2, (δD60A:GFP2 accumulates foci or patched structures on the nucleoid. We propose that (δ:GFP2 binding to different nucleoid regions and to ω2-parS might generate (δ:GFP2 gradients that could direct plasmid movement. The iterative pairing and unpairing cycles may tether plasmids equidistantly on the nucleoid to ensure faithful plasmid segregation by a mechanism compatible with the diffusion-ratchet mechanism as proposed from in vitro reconstituted systems.

  19. The efficacy and safety of combined microneedle fractional radiofrequency and sublative fractional radiofrequency for acne scars in Asian skin.

    Science.gov (United States)

    Park, Jae Yang; Lee, Eo Gin; Yoon, Moon Soo; Lee, Hee Jung

    2016-06-01

    Microneedle fractional radiofrequency has been reported to be effective for improving wrinkles, enlarged pores and various scars. Sublative fractional radiofrequency has been shown to induce both fractional ablation of epidermis and upper dermal remodelling, which had rejuvenation effects in photoaged skin. Both modalities may have the potential synergy to improve acne scars. To evaluate the efficacy and safety of combined microneedle and sublative fractional radiofrequency for acne scars in Asian skin. Twenty subjects comprised 11 males and 9 females (mean age 23.65 ± 2.94, skin phototype III-IV) with moderate to severe acne scars. The subjects received three consecutive combined microneedle and sublative fractional radiofrequency at 4-week intervals over 12 weeks. Both blinded dermatologists and subjects assessed the clinical improvement based on the standardized photography and questionnaires, respectively. The quartile grading scale was utilized and defined as follows: grade 1, 0-25% improvement; grade 2, 26-50% improvement; grade 3, 51-75% improvement and grade 4, 76-100% improvement. All 20 subjects were assessed to have grade 2 or more clinical improvement by physicians; four (20%) had grade 4, 10 (50%) had grade 3, and six (30%) had grade 2 improvement. The subjects' grading also showed a good concordance as indicated by Kappa index of 0.695. The mean duration of post-therapy crusting was 5.2 days and post-therapy erythema lasted 2.5 days. Combined microneedle and sublative fractional radiofrequency can have a positive therapeutic effect with no serious complications and may provide a new therapeutic approach on acne scars in Asians. © 2015 Wiley Periodicals, Inc.

  20. ¡París!

    Directory of Open Access Journals (Sweden)

    Beatriz Caballero

    2003-01-01

    Full Text Available El día no le alcanzaba para caminarlo. Conocía cada puente, cada calle,plaza, museo, rincón, iglesia, café, y la mesa con el mejor ángulo para mirar siempre una iglesia, ojalá Saint-Germain-des-Pres, o Notre-Dame. Siempre contaba la impresión que le había causado a Bolívar ver allí cuando el papa coronó a Napoleón. Él se iba para la oficina todos los días, Luis a un taller a pintar, Antonio a estudiar ciencias políticas, yo al colegio y mamá hacía las cosas prácticas. Aprendíamos francés todos al tiempo y por la noche nos contábamos lo nuevo que cada uno había aprendido. Mamá después, cuando ya se quería volver, decía que París nos había maleado a todos. Estaba en pleno furor el cine francés de la "nueva ola", pero ella sólo me llevaba a ver películas de vaqueros pues no se fiaba de la clasificación de los periódicos.

  1. Radio-frequency identification of surgical sponges in the abdominal cavity of pigs.

    Science.gov (United States)

    Wiederkehr, Julio Cesar; Gama, Ricardo R; Wiederkehr, Henrique A; Stelmasuk, Kleber; Carvalho, Caroline A; Wiederkehr, Barbara A

    2014-06-01

    Counting the sponges is an important step in surgical procedures. A miscount may impact the patient's health, and it also has legal implications for the surgeon. This is an experimental study evaluating radio-frequency technology used in the perioperative period to identify surgical sponges left in the peritoneal cavity of swine. Radio-frequency labeled-disc identification tags were sewn into 40 surgical towels. Twenty labels had the ability to emit radio-frequency waves, and 20 labels were inert to radio-frequency identification. Twenty adult pigs that underwent laparotomy and randomly received two surgical sponges were scanned by a radio-frequency identification antenna. This method presented a positive predictive value of 100% and 100% specificity and sensitivity, as all of the tagged surgical sponges were detected. Radio-frequency identification has been proved to be a useful method for the identification of surgical sponges within the abdominal cavities of swine.

  2. Radiofrequency denervation for chronic low back pain.

    Science.gov (United States)

    Maas, Esther T; Ostelo, Raymond W J G; Niemisto, Leena; Jousimaa, Jukkapekka; Hurri, Heikki; Malmivaara, Antti; van Tulder, Maurits W

    2015-10-23

    Radiofrequency (RF) denervation, an invasive treatment for chronic low back pain (CLBP), is used most often for pain suspected to arise from facet joints, sacroiliac (SI) joints or discs. Many (uncontrolled) studies have shown substantial variation in its use between countries and continued uncertainty regarding its effectiveness. The objective of this review is to assess the effectiveness of RF denervation procedures for the treatment of patients with CLBP. The current review is an update of the review conducted in 2003. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, three other databases, two clinical trials registries and the reference lists of included studies from inception to May 2014 for randomised controlled trials (RCTs) fulfilling the inclusion criteria. We updated this search in June 2015, but we have not yet incorporated these results. We included RCTs of RF denervation for patients with CLBP who had a positive response to a diagnostic block or discography. We applied no language or date restrictions. Pairs of review authors independently selected RCTs, extracted data and assessed risk of bias (RoB) and clinical relevance using standardised forms. We performed meta-analyses with clinically homogeneous studies and assessed the quality of evidence for each outcome using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. In total, we included 23 RCTs (N = 1309), 13 of which (56%) had low RoB. We included both men and women with a mean age of 50.6 years. We assessed the overall quality of the evidence as very low to moderate. Twelve studies examined suspected facet joint pain, five studies disc pain, two studies SI joint pain, two studies radicular CLBP, one study suspected radiating low back pain and one study CLBP with or without suspected radiation. Overall, moderate evidence suggests that facet joint RF denervation has a greater effect on pain compared with placebo over the

  3. Pulsed and continuous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn.

    NARCIS (Netherlands)

    Zundert, J. van; Louw, A.J. de; Joosten, E.A.J.; Kessels, A.G.H.; Honig, W.; Dederen, P.J.W.C.; Veening, J.G.; Vles, J.S.; Kleef, M. van

    2005-01-01

    BACKGROUND: Pulsed radiofrequency treatment has recently been described as a non-neurodestructive or minimally neurodestructive alternative to radiofrequency heat lesions. In clinical practice long-lasting results of pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion for

  4. Combined kinetic and transport modeling of radiofrequency current drive

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, R.; Giruzzi, G. [Association Euratom-CEA, CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee (DRFC), 13 - Saint-Paul-lez-Durance (France); Barbato, E. [Associazione EURATOM-ENEA sulla Fusione, Frascati (Italy)

    2000-07-01

    A numerical model for predictive simulations of radiofrequency current drive in magnetically confined plasmas is developed. It includes the minimum requirements for a self consistent description of such regimes, i.e., a 3-D ,kinetic equation for the electron distribution function, 1-D heat and current transport equations, and resonant coupling between velocity space and configuration space dynamics, through suitable wave propagation equations. The model finds its full application in predictive studies of complex current profile control scenarios in tokamaks, aiming at the establishment of internal transport barriers by the simultaneous use of various radiofrequency current drive methods. The basic properties of this non-linear numerical system are investigated and illustrated by simulations applied to reversed magnetic shear regimes obtained by Lower Hybrid and Electron Cyclotron current drive for parameters typical of the Tore Supra tokamak. (authors)

  5. Irrigated Tip Catheters for Radiofrequency Ablation in Ventricular Tachycardia

    Directory of Open Access Journals (Sweden)

    Andreas Müssigbrodt

    2015-01-01

    Full Text Available Radiofrequency (RF ablation with irrigated tip catheters decreases the likelihood of thrombus and char formation and enables the creation of larger lesions. Due to the potential dramatic consequences, the prevention of thromboembolic events is of particular importance for left-sided procedures. Although acute success rates of ventricular tachycardia (VT ablation are satisfactory, recurrence rate is high. Apart from the progress of the underlying disease, reconduction and the lack of effective transmural lesions play a major role for VT recurrences. This paper reviews principles of lesion formation with radiofrequency and the effect of tip irrigation as well as recent advances in new technology. Potential areas of further development of catheter technology might be the improvement of mapping by better substrate definition and resolution, the introduction of bipolar and multipolar ablation techniques into clinical routine, and the use of alternative sources of energy.

  6. Simple Stabilized Radio-Frequency Transfer With Optical Phase Actuation

    Science.gov (United States)

    Gozzard, David R.; Schediwy, Sascha W.; Courtney-Barrer, Benjamin; Whitaker, Richard; Grainge, Keith

    2018-02-01

    We describe and experimentally evaluate a stabilized radio-frequency transfer technique that employs optical phase sensing and optical phase actuation. This technique can be achieved by modifying existing stabilized optical frequency equipment and also exhibits advantages over previous stabilized radio-frequency transfer techniques in terms of size and complexity. We demonstrate the stabilized transfer of a 160 MHz signal over an 166 km fiber optical link, achieving an Allan deviation of 9.7x10^-12 Hz/Hz at 1 s of integration, and 3.9x10^-1414 Hz/Hz at 1000 s. This technique is being considered for application to the Square Kilometre Array SKA1-low radio telescope.

  7. Radiofrequency catheter ablation for the management of cardiac tachyarrhythmias.

    Science.gov (United States)

    Wood, M; Ellenbogen, K; Stambler, B

    1993-10-01

    Radiofrequency catheter ablation techniques allow for safe and highly effective curative therapy of a variety of cardiac dysrhythmias. The technique involves the delivery of a high-frequency, alternating electrical current through an intravascular catheter to sites of arrhythmogenic myocardium. This current induces resistive electrical heating of the tissue, resulting in discrete areas of myocardial destruction through coagulation and desiccation. Dysrhythmias most commonly treated with these techniques are atrioventricular nodal reentry and tachycardias related to accessory atrioventricular bypass tracts. For these dysrhythmias, success rates of 90% to 95% are achievable with a low (2% to 4%) risk of complications. Radiofrequency catheter ablation techniques also have been used to treat ventricular tachycardias, atrial flutter, ectopic atrial tachycardia, and sinus node reentry, albeit with lower success rates. These techniques are still evolving, alternate energy sources (such as microwave and laser) and improved catheter technology should enhance the technique's safety and efficacy for a wider range of dysrhythmias.

  8. 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...

  9. Mechanisms for enlarging lesion size during irrigated tip radiofrequency ablation

    DEFF Research Database (Denmark)

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

    2004-01-01

    INTRODUCTION: Irrigated tip radiofrequency ablation of cardiac arrhythmias was developed to increase the size of the radiofrequency-induced lesion, since cooling of the electrode tip allows use of higher power settings. The purpose of this study was to determine if the increased lesion size during...... and in vivo canine left ventricles were ablated. In vitro closed loop tip and showerhead irrigated tip catheters were compared. In vitro and in vivo showerhead tip catheters irrigated with solutions having different ionic content were compared. We found no difference in lesion size for closed loop...... and showerhead-type catheters (998 +/- 345 vs. 811 +/- 313 mm(3) during power-controlled ablation and 227 +/- 76 vs 318 +/- 127 mm(3) during temperature-controlled ablation). For irrigation with liquids having increasing ionic strength we found a decrease in lesion volume in vitro (361 +/- 249 vs. 812 +/- 229 mm...

  10. Complications associated with radiofrequency ablation of pulmonary veins.

    Science.gov (United States)

    Madrid Pérez, J M; García Barquín, P M; Villanueva Marcos, A J; García Bolao, J I; Bastarrika Alemañ, G

    Radiofrequency ablation is an efficacious alternative in patients with symptomatic atrial fibrillation who do not respond to or are intolerant to at least one class I or class III antiarrhythmic drug. Although radiofrequency ablation is a safe procedure, complications can occur. Depending on the location, these complications can be classified into those that affect the pulmonary veins themselves, cardiac complications, extracardiac intrathoracic complications, remote complications, and those that result from vascular access. The most common complications are hematomas, arteriovenous fistulas, and pseudoaneurysms at the puncture site. Some complications are benign and transient, such as gastroparesis or diaphragmatic elevation, whereas others are potentially fatal, such as cardiac tamponade. Radiologists must be familiar with the complications that can occur secondary to pulmonary vein ablation to ensure early diagnosis and treatment. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Pulse-Dose Radiofrequency in Athletic Pubalgia: Preliminary Results.

    Science.gov (United States)

    Masala, Salvatore; Fiori, Roberto; Raguso, Mario; Ojango, Christine; Morini, Marco; Cuzzolino, Alessandro; Calabria, Eros; Simonetti, Giovanni

    2017-05-01

    Chronic pubalgia affects around 10% of athletes. To determine the role of pulse-dose radiofrequency (PDRF) in athletes with chronic pubalgia and investigate the causes with imaging. Prospective nonrandomized single-group study. PDRF was performed on 32 patients with a chronic pain that had been refractory to conservative therapies during the last 3 mo. The genital branches of the genitofemoral, ilioinguinal, and iliohypogastric nerves and the obturator nerve were the goals of treatment. A 10-cm, 20-gauge cannula was inserted with a percutaneous access on the upper and lower edges of the iliopubic branch. After the spindle was removed, a radiofrequency needle with a 10-mm "active tip" was inserted. The radiofrequency technique was performed with 1200 pulses at 45 V and 20-ms duration, followed by a 480-ms silent phase. The follow-up with a clinical examination was performed at 1, 3, 6, and 9 mo after the procedure. During the follow-up visits, the patients were asked to rate their pain on a 0-10 VAS scale. All of the enrolled patients completed the study. Mean VAS score before the treatment was 8.4 ± 0.6. Twenty-four patients had a reduction of pain VAS scores more than 50% during all follow-up visits and started training and physiotherapy in the days after the radiofrequency procedure. Six patients, each treated 2 times, had a reduction more than 50% of VAS scores and could start training and physiotherapy only after the 2nd procedure. One patient had no pain relief with 2 treatments. Pain intensity decreased up to 9 mo in 31 patients (mean VAS scores 3.4 ± 0.5 at 6 mo and 3.8 ± 0.9 at 9 mo). No complications were observed. PDRF is an effective and safe technique in management of chronic pubalgia in athletes.

  12. C9.A/14 steelwork joints de poutres par plaque frontale : assemblages par gousset

    CERN Document Server

    2015-01-01

    Les Tables de résistances ultimes des assemblages boulonnés par plaque frontale et par gousset, complétées par une description des modèles de calcul et des exemples d’application, ont pour but de faciliter la tâche de l'ingénieur et du constructeur. Cette première partie C9.A/14 contient les chapitres suivants: - Joints de poutres par plaque frontale en acier S235 et S355 - Assemblages par gousset en acier S235 et S355 Les Tables contiennent des données relatives à la géométrie ainsi que les valeurs de calcul correspondantes des résistances ultimes des assemblages ; elles remplacent le chapitre « Assemblages par plaques frontales et boulons HR » des anciennes Tables C9.1 de 1983 / 2002. Le calcul de ces assemblages par plaque frontale est basé sur les hypothèses du modèle de la méthode des composants décrite dans la norme SN EN 1993-1-8. Les vérifications sont effectuées selon la norme SIA 263:2013. Les assemblages par gousset remplacent les assemblages par double cornière, (telle...

  13. Radiofrequency coils for magnetic resonance applications: theory, design, and evaluation.

    Science.gov (United States)

    Giovannetti, Giulio; Hartwig, Valentina; Positano, Vincenzo; Vanello, Nicola

    2014-01-01

    Magnetic resonance imaging and magnetic resonance spectroscopy are noninvasive diagnostic techniques based on the phenomenon of nuclear magnetic resonance. Radiofrequency coils are key components in both the transmission and receiving phases of magnetic resonance systems. Transmitter coils have to produce a highly homogeneous alternating field in a wide field of view, whereas receiver coils have to maximize signal detection while minimizing noise. Development of modern magnetic resonance coils often is based on numerical methods for simulating and predicting coil performance. Numerical methods allows the behavior of the coil in the presence of realistic loads to be simulated and the coil's efficiency at high magnetic fields to be investigated. After being built, coils have to be characterized in the laboratory to optimize their setting and performance by extracting several quality indices. Successively, coils performance has to be evaluated in a scanner using standardized image quality parameters with phantom and human experiments. This article reviews the principles of radiofrequency coils, coil performance parameters, and their estimation methods using simulations, workbench, and magnetic resonance experiments. Finally, an overview of future developments in radiofrequency coils technology is included.

  14. Clinical effect of radiofrequency ablation in treatment of hepatic hemangioma

    Directory of Open Access Journals (Sweden)

    SUN Libo

    2017-01-01

    Full Text Available ObjectiveTo investigate the clinical effect and application experience of radiofrequency ablation in the treatment of hepatic hemangioma. MethodsA retrospective analysis was performed for the clinical data of 34 patients with hepatic hemangioma who underwent radiofrequency ablation in Beijing You′an Hospital from January 2011 to June 2015. Among these patients, 22 underwent ultrasound-guided percutaneous transhepatic radiofrequency ablation (PRFA, 10 underwent laparoscopic radiofrequency ablation (LRFA, and 2 underwent open hepatectomy combined with hepatic hemangioma radiofrequency ablation (OHRFA. The intraoperative and postoperative conditions were compared between patients undergoing different methods of radiofrequency ablation. ResultsAll the patients underwent successful radiofrequency ablation. The mean time of operation in PRFA group, LRFA group, and OHRFA group was 75.45±27.33 min, 97.90±32.37 min, and 192.5 min, respectively, and the median hospital stay in these groups was 3 d, 3 d, and 10.5 d, respectively. There were no serious complications during and after surgery. The complete remission rate at 1 month after surgery was 94.1%(32/34. The patients were followed up for 6-24 months and no recurrence was observed. ConclusionRadiofrequency ablation is a safe and effective procedure for the treatment of hepatic hemangioma. Strict control of surgical indications and selection of proper radiofrequency ablation approach are of great importance.

  15. Initial radiofrequency ablation failure for hepatocellular carcinoma: repeated radiofrequency ablation versus transarterial chemoembolisation.

    Science.gov (United States)

    Kim, S S; Kang, T W; Kim, M; Lee, M W; Cho, S K; Paik, Y H; Kim, M-J

    2018-02-01

    To compare the long-term therapeutic outcomes of repeated radiofrequency ablation (RFA) with that of transarterial chemoembolisation (TACE) in patients with local tumour progression (LTP) after initial RFA treatment for hepatocellular carcinoma (HCC). This retrospective study was approved by the institutional review board and the requirement for informed consent was waived. Between July 2006 and February 2012, 713 patients underwent RFA for single HCC as a first-line treatment. Fifty-eight patients who showed LTP as initial tumour recurrence post-RFA treatment were included. Patients were treated with either repeated RFA (n=33) or TACE (n=25). TACE was performed as an alternative therapeutic option when repeated RFA was not feasible based on the planning ultrasonography. Recurrence-free and overall survival rates were estimated using the Kaplan-Meier method. Prognostic factors for outcomes were evaluated using the Cox proportional hazards model. Both groups did not show significant differences in terms of baseline characteristics, with the exception being the proportion of subphrenic tumours (p=0.031). The RFA and TACE groups did not differ significantly in their 5-year recurrence-free and overall survival rates (17% versus 10.7% and 72.7% versus 51.9%, respectively, with all p-values >0.05). In addition, multivariate analyses revealed that type of treatment was not associated with recurrence-free or overall survival in patients with post-RFA LTP. TACE is an effective treatment, comparable to repeated RFA, in patients with LTP after initial RFA when repeated RFA is not feasible. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  16. Structural analysis of the ParR/parC plasmid partition complex

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Ringgaard, Simon; Mercogliano, Christopher P

    2007-01-01

    . coli plasmid pB171. ParR forms a tight dimer resembling a large family of dimeric ribbon-helix-helix (RHH)2 site-specific DNA-binding proteins. Crystallographic and electron microscopic data further indicate that ParR dimers assemble into a helix structure with DNA-binding sites facing outward. Genetic...

  17. Protease-activated receptor (PAR)-2 is required for PAR-1 signalling in pulmonary fibrosis

    NARCIS (Netherlands)

    Lin, Cong; von der Thüsen, Jan; Daalhuisen, Joost; ten Brink, Marieke; Crestani, Bruno; van der Poll, Tom; Borensztajn, Keren; Spek, C. Arnold

    2015-01-01

    Idiopathic pulmonary fibrosis is the most devastating diffuse fibrosing lung disease of unknown aetiology. Compelling evidence suggests that both protease-activated receptor (PAR)-1 and PAR-2 participate in the development of pulmonary fibrosis. Previous studies have shown that bleomycin-induced

  18. LES LESIONS DES ORGANES GENITAUX EXTERNES PAR ARME A

    African Journals Online (AJOL)

    Les lésions par arme à feu définies comme toute blessure produite sur le corps humain par rapprochement ou le choc d'une arme à feu, sont généralement rares qu'il s'agisse de plaies par armes de guerre ou de plaies par projectiles dans un contexte civil“. Parmi les facteurs de gravité des plaies par balles figu-.

  19. Traitement des eaux par électrofloculation

    OpenAIRE

    Cansado, Isabel

    1997-01-01

    Traitement des eaux par electrofloculation Les écosystèmes aquatiques sont très affectés par les eaux de rejet qui sont déversées dans les cours d’eau. La charge de ces eaux existe sous diverses formes: solutés, colloïdes ou particules. Il est important de traiter l’eau usée à de faibles coûts au lieu de la rejeter directement dans le milieu récepeteur. Dans le but d’améliorer les procédés physico-chimiques de déstabilisation des émulsions, nous étudions les traitements par électrocoagulat...

  20. 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.

  1. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Science.gov (United States)

    2010-04-01

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

  2. 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.

  3. 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

  4. Factors Influencing Lesion Formation During Radiofrequency Catheter Ablation

    Directory of Open Access Journals (Sweden)

    Olaf J. Eick

    2003-07-01

    Full Text Available In radiofrequency (RF ablation, the heating of cardiac tissue is mainly resistive. RF current heats cardiac tissue and in turn the catheter electrode is being heated. Consequently, the catheter tip temperature is always lower - or ideally equal - than the superficial tissue temperature. The lesion size is influenced by many parameters such as delivered RF power, electrode length, electrode orientation, blood flow and tissue contact. This review describes the influence of these different parameters on lesion formation and provides recommendations for different catheter types on selectable parameters such as target temperatures, power limits and RF durations

  5. The Influence of Radiofrequency Electromagnetic Radiation on the Platelet Aggregation

    Directory of Open Access Journals (Sweden)

    Gulzoda M. Khamidova

    2014-09-01

    Full Text Available The purpose of this study was to examine the impact of radiofrequency electromagnetic fields (RF-EMFs on platelet aggregation (PA in individuals working for a long time under a direct and continuous RF-EMF exposure. We examined 119 persons aged from 22 to 65 years. In individuals working under the direct and constant exposure to RF-EMFs, the various changes of PA with a predominance of hyperaggregation are detected. The dependence of the changes in the indicators of PA on length of work in conditions of RF-EMF exposure is determined.

  6. 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.

  7. A 66-kDa protein of bovine hypophyseal Pars tuberalis induces luteinizing hormone release from rat Pars distalis.

    Science.gov (United States)

    Lafarque, Martha; Oliveros, Liliana

    2008-12-01

    In this study, evidence for a factor secreted by bovine hypophyseal pars tuberalis that stimulates luteinizing hormone (LH) release from rat pars distalis cells is shown. The secretion products of bovine pars tuberalis cells into the culture medium were assayed on dispersed rat pars distalis cells in 30 min incubations and superfusion experiments. The culture medium from pars tuberalis total cell populations, added at a dose of 6 microg per tube, induced the greater LH release from pars distalis cells, without effect on follicle stimulating hormone (FSH) release. After pars tuberalis cells separation on a discontinuos Percoll gradient, only the culture medium of cells from 50 and 60% strength Percoll were able to release LH from rat pars distalis cells. Therefore, cell fractions from 50 and 60% strenght Percoll were cultured together. To elicit maximal LH release (6 times the basal output), with the addition of 2 microg of pars tuberalis protein was required, suggesting that these cells produce the factor or factors which affect pars distalis gonadotrope cells. After applying the pars tuberalis culture medium on 12% SDS-PAGE, the band with biological activity was that of 66-kDal. Fifty ng protein of its eluate released almost 9 times the basal output of LH from pars distalis cells. Results suggest a modulating effect of a protein from the bovine pars tuberalis on rat cultured gonadotrope cells from the pars distalis.

  8. Par-4: A New Activator of Myosin Phosphatase

    Science.gov (United States)

    Vetterkind, Susanne; Lee, Eunhee; Sundberg, Eric; Poythress, Ransom H.; Tao, Terence C.; Preuss, Ute

    2010-01-01

    Myosin phosphatase (MP) is a key regulator of myosin light chain (LC20) phosphorylation, a process essential for motility, apoptosis, and smooth muscle contractility. Although MP inhibition is well studied, little is known about MP activation. We have recently demonstrated that prostate apoptosis response (Par)-4 modulates vascular smooth muscle contractility. Here, we test the hypothesis that Par-4 regulates MP activity directly. We show, by proximity ligation assays, surface plasmon resonance and coimmunoprecipitation, that Par-4 interacts with the targeting subunit of MP, MYPT1. Binding is mediated by the leucine zippers of MYPT1 and Par-4 and reduced by Par-4 phosphorylation. Overexpression of Par-4 leads to increased phosphatase activity of immunoprecipitated MP, whereas small interfering RNA knockdown of endogenous Par-4 significantly decreases MP activity and increases MYPT1 phosphorylation. LC20 phosphorylation assays demonstrate that overexpression of Par-4 reduces LC20 phosphorylation. In contrast, a phosphorylation site mutant, but not wild-type Par-4, interferes with zipper-interacting protein kinase (ZIPK)-mediated MP inhibition. We conclude from our results Par-4 operates through a “padlock” model in which binding of Par-4 to MYPT1 activates MP by blocking access to the inhibitory phosphorylation sites, and inhibitory phosphorylation of MYPT1 by ZIPK requires “unlocking” of Par-4 by phosphorylation and displacement of Par-4 from the MP complex. PMID:20130087

  9. CFD analysis of PAR performance as function of inlet design

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kweonha, E-mail: khpark@kmou.ac.kr [Division of Mechanical and Energy systems Engineering, Korea Maritime University, Dongsam-dong, Yeongdo-gu, Busan 606-791 (Korea, Republic of); Khor, Chong Lee, E-mail: itachi_829@hotmail.com [Department of Mechanical Engineering, Korea Maritime University (Korea, Republic of)

    2016-01-15

    Highlights: • The new concept of PAR (passive autocatalytic recombiner) was proposed and analyzed. • Guidance wall was added at the bottom of PAR to enhance the flow rate through the catalyst. • The new concept of PAR was proved to have a better hydrogen removal performance. - Abstract: Passive autocatalytic recombiner (PAR) is very useful hydrogen mitigation measurement. It is widely implemented in the current and advanced light water reactors (ALWRs). The design of the PARs should be optimized for the specific use under severe accident scenarios. Several techniques and innovations have been fused into the PAR, as an effort to increase its efficiency of hydrogen mitigation. This study proposes different concepts of PAR, which applied some changes to the honeycomb catalyst PAR made by the Korea Nuclear Technology (KNT) Inc. Two slices of plate are added to the bottom of PAR model, which intended to act as a reflection wall and promote the gas flow into PAR. Hydrogen volume fraction was given 4 vol. % which tested by KNT to investigate the performance of PAR in different direction gas flow conditions to see maximum hydrogen recombination rate. The new concept of PAR was proved to have a better hydrogen removal performance compared to the original honeycomb catalyst PAR.

  10. PAR-TERRA directs homologous sex chromosome pairing.

    Science.gov (United States)

    Chu, Hsueh-Ping; Froberg, John E; Kesner, Barry; Oh, Hyun Jung; Ji, Fei; Sadreyev, Ruslan; Pinter, Stefan F; Lee, Jeannie T

    2017-08-01

    In mammals, homologous chromosomes rarely pair outside meiosis. One exception is the X chromosome, which transiently pairs during X-chromosome inactivation (XCI). How two chromosomes find each other in 3D space is not known. Here, we reveal a required interaction between the X-inactivation center (Xic) and the telomere in mouse embryonic stem (ES) cells. The subtelomeric, pseudoautosomal regions (PARs) of the two sex chromosomes (X and Y) also undergo pairing in both female and male cells. PARs transcribe a class of telomeric RNA, dubbed PAR-TERRA, which accounts for a vast majority of all TERRA transcripts. PAR-TERRA binds throughout the genome, including to the PAR and Xic. During X-chromosome pairing, PAR-TERRA anchors the Xic to the PAR, creating a 'tetrad' of pairwise homologous interactions (Xic-Xic, PAR-PAR, and Xic-PAR). Xic pairing occurs within the tetrad. Depleting PAR-TERRA abrogates pairing and blocks initiation of XCI, whereas autosomal PAR-TERRA induces ectopic pairing. We propose a 'constrained diffusion model' in which PAR-TERRA creates an interaction hub to guide Xic homology searching during XCI.

  11. Radiofrequency fistulotomy: a better alternative for treating low anal fistula

    Directory of Open Access Journals (Sweden)

    Pravin Jaiprakash Gupta

    Full Text Available CONTEXT: Wide varieties of approaches are employed in dealing with low anal fistula. However, the simple method of laying open the fistula tract (fistulotomy is still considered to be the favored one. MATERIALS AND METHODS: A modified approach to the procedure of fistulotomy is discussed. This study describes the procedure, which used a technique of radiofrequency surgery, and its outcome in 232 patients with low anal fistula. The patients were followed for a period of 15 months. RESULTS: The patients were discharged on the same day as the procedure. The mean period off work was four days. The average healing time recorded was 67 days. Four wound complications in the form of premature closure of the external wound were noted, which required trimming of the edges. Two of these wounds remained unhealed. The recurrence rate was 1.7%. CONCLUSION: In this era when the emphasis is on criteria like the minimization of hospital stay, reduction of postoperative pain, early resumption of work and low and comparable recurrence rates, there is a future for the procedure of radiofrequency fistulotomy.

  12. New concept for treating female stress urinary incontinence with radiofrequency.

    Science.gov (United States)

    Lordelo, Patrícia; Vilas Boas, Andrea; Sodré, Danielle; Lemos, Amanda; Tozetto, Sibele; Brasil, Cristina

    2017-01-01

    To evaluate the clinical response and adverse effects of radiofrequency on the urethral meatus in the treatment of stress urinary incontinence in women. This phase one study included ten women with Stress Urinary Incontinence (SUI). The evaluation consisted of 1 hour Pad tests to quantify urine loss and to assess the degree of procedure satisfaction by using the Likert scale. To evaluate safety, we observed the number of referred side effects. Average age was 53.10 years±7.08 years. In assessing the final Pad Test, 70% showed a reduction and 30% a worsening of urinary loss. Using the Pad Test one month later, there was a reduction in all patients (p=0.028). The degree of satisfaction was 90% and no side effects have been observed. One patient reported burning sensation. The treatment of SUI with radiofrequency on the urethral meatus has no adverse effects, being a low risk method that reduces urinary loss in women. However, to increase the validity of the study, larger clinical trials are warranted. Copyright® by the International Brazilian Journal of Urology.

  13. Radiofrequency Ablation of Hepatocellular Carcinoma: A Literature Review

    Directory of Open Access Journals (Sweden)

    Yasunori Minami

    2011-01-01

    Full Text Available Radiofrequency ablation (RFA of liver cancers can be performed safely using percutaneous, laparoscopic, or open surgical techniques, and much of the impetus for the use of RFA has come from cohort series that have provided an evidence base for this technique. Here, we give an overview of the current status of radiofrequency ablation (RFA for hepatocellular carcinoma (HCC, including its physical properties, to assess the characteristics that make this technique applicable in clinical practice. We review the technical development of probe design and summarize current indications and outcomes of reported clinical use. An accurate evaluation of treatment response is very important to secure successful RFA therapy since a sufficient safety margin (at least 0.5 cm can prevent local tumor recurrences. We also provide a profile of side effects and information on the integration of this technique into the general management of patients with HCC. To minimize complications of RFA, physicians should be familiar with each feature of complication. Appropriate management of complications is essential for successful RFA treatment. Moreover, adjuvant therapy, such as molecular targeted therapies following curative therapy, is expected to further improve survival after RFA.

  14. Radiofrequency ablation for pulmonary metastases from gastrointestinal cancers.

    Science.gov (United States)

    Baba, Yoshifumi; Watanabe, Masayuki; Yoshida, Naoya; Kawanaka, Koichi; Yamashita, Yasuyuki; Baba, Hideo

    2014-01-01

    The lung is one of the most common targets of metastases from gastrointestinal (GI) cancers. Surgical treatment (i.e., metastasectomy) is an accepted therapeutic option for pulmonary metastases from GI cancers. However, surgery may be contraindicated in advanced stages of cancer, compromised lung function, and/or comorbidities. This issue has prompted the search for innovative and less invasive ways of treating pulmonary metastases. Image-guided radiofrequency ablation (RFA) has attracted great interest as a minimally invasive approach against intrathoracic malignancies. In this technique, radiofrequency energy is applied via a needle electrode inserted into the target tissue. As the cells are agitated by the applied energy, they release heat, causing denaturation and cell death. Recently, this technique has been used on patients with pulmonary metastatic disease arising from GI cancers such as colorectal cancer, esophageal cancer, and hepatocellular carcinoma, as well as on patients with primary lung cancer. The present review updates the clinical outcomes and advances in RFA therapy of lung metastases from GI cancers.

  15. [Radiofrequency catheter ablation therapy in elderly patients with supraventricular tachycardia].

    Science.gov (United States)

    Shimizu, A; Yamagata, T; Tatsuno, H; Esato, M; Ueyama, T; Hayano, T; Oomura, M; Tamura, K; Matsuzaki, M

    1998-06-01

    138 patients with Wolf-Parkinson-White (WPW) syndrome (n = 96), atrioventricular nodal reentrant tachycardia (AVNRT; n = 27) and the other supraventricular tachycardia (n = 15), were divided into two groups, a control group (less than 65 years old; n = 108) and an elderly group (more than 66 years old; n = 30). We then estimated the success rate and safety of radiofrequency ablation for supraventricular tachycardia in elderly patients. For WPW syndrome, there were 76 (97%) successes and 9 (13%) recurrences in the control group (n = 78). In the elderly group of WPW patients, the number of successes was 18 (100%) and the number of recurrences one (63%). In 27 patients with AVNRT, the number of successes was 26 (96%) and there were no recurrences. In 15 patients with some other supraventricular tachycardia, there were 11 patients (73%) successes and one recurrence (11%). Major complications consisted of cardiac tamponade in 2 patients, dissecting aneurysm in one patient and cerebral embolism in one patients. All major complications occurred in patients with WPW syndrome. The cause of the complications, except the cerebral embolism was manipulation of the electrical or ablation catheter. Three of four patients with major complications belonged to the control group. It is possible that radiofrequency catheter ablation for supraventricular tachycardia in elderly patients is safe and highly effective. However, it is still invasive therapy. Ablation on a left accessory pathway by the transaortic valve approach especially needs meticulous care.

  16. Radio-frequency identification: its potential in healthcare.

    Science.gov (United States)

    2005-05-01

    Radio-frequency identification (RFID) technology is just starting to make inroads into healthcare. RFID uses radio-frequency tags attached to people or objects to provide identification, tracking, security, and other functions that fall under the general heading of automatic identification and data capture (AIDC). In the retail supply chain, RFID is already well established as a way to reduce theft and track objects from manufacture through shipment to delivery. In healthcare, basic RFID is already being used to track patients for anti-elopement and anti-abduction programs. As more sophisticated systems move into hospitals, RFID is also beginning to see use to provide more extensive patient identification than traditional bar coding can, and to track and locate capital equipment within the hospital. In years to come, RFID could be used for a variety of applications, including tracking and matching blood for transfusions, tracking pharmaceuticals, and combating the counterfeiting of medical products. RFID may ultimately be used for many of the functions currently carried out using bar coding--but not until the cost of RFID comes down. For the foreseeable future, the two technologies are likely to be used in tandem in many hospitals. In this article, we describe the components and operation of RFID systems and detail the different ways in which these systems are being used, and could be used, in hospitals.

  17. Treatment of trigeminal neuralgia: role of radiofrequency ablation

    Directory of Open Access Journals (Sweden)

    Dessy R Emril

    2010-12-01

    Full Text Available Dessy R Emril1 Kok-Yuen Ho21Neurology Department, Syiah Kuala University/Dr Zainoel Abidin Hospital, Banda Aceh, Indonesia; 2Pain Management Centre, Raffles Hospital, SingaporeAbstract: Trigeminal neuralgia (TN is a neuropathic pain condition affecting the face. It has a significant impact on the quality of life and physical function of patients. Evidence suggests that the likely etiology is vascular compression of the trigeminal nerve leading to focal demyelination and aberrant neural discharge. Secondary causes such as multiple sclerosis or brain tumors can also produce symptomatic TN. Treatment must be individualized to each patient. Carbamazepine remains the drug of choice in the first-line treatment of TN. Minimally invasive interventional pain therapies and surgery are possible options when drug therapy fails. Younger patients may benefit from microvascular decompression. Elderly patients with poor surgical risk may be more suitable for percutaneous trigeminal nerve rhizolysis. The technique of radiofrequency rhizolysis of the trigeminal nerve is described in detail in this review.Keywords: interventional treatment, minimally invasive, pain management, radiofrequency rhizolysis, trigeminal neuralgia 

  18. Radiofrequency catheter ablation for atrial flutter following orthotopic heart transplantation

    Science.gov (United States)

    Pitt, M; Bonser, R; Griffith, M

    1998-01-01

    A 26 year old woman with a diagnosis of limb girdle muscular dystrophy and peripartum cardiomyopathy underwent orthotopic heart transplantation using standard atrial anastomoses. Recurrent atrial flutter was demonstrated in the absence of histological evidence of cellular rejection. Radiofrequency ablation of the flutter circuit was successfully performed allowing the avoidance of long term antiarrhythmic therapy. Ten weeks following ablation and cessation of amiodarone, presyncopal symptoms were found, associated with daytime and nocturnal sinus pauses of 2.9 seconds and 4.2 seconds, respectively. There was no evidence of AV node conduction impairment. In view of the continued absence of cellular rejection and the evident denervated state of the heart, the pauses reflected significant donor sinus node dysfunction; therefore, an AAIR permanent pacing system was implanted. At the time of pacemaker implantation atrial pacing at 150 beats/min did not produce significant PR interval prolongation or AV block. This case serves to advise rigorous follow up in such patients to continue to seek evidence of sinus node dysfunction potentially requiring permanent pacemaker implantation.

 Keywords: heart transplantation;  atrial flutter;  radiofrequency catheter ablation PMID:9616353

  19. Interactive multi-criteria planning for radiofrequency ablation.

    Science.gov (United States)

    Schumann, Christian; Rieder, Christian; Haase, Sabrina; Teichert, Katrin; Süss, Philipp; Isfort, Peter; Bruners, Philipp; Preusser, Tobias

    2015-06-01

    Image-guided radiofrequency ablation (RFA) is a broadly used minimally invasive method for the thermal destruction of focal liver malignancies using needle-shaped instruments. The established planning workflow is based on examination of 2D slices and manual definition of the access path. During that process, multiple criteria for all possible trajectories have to be taken into account. Hence, it demands considerable experience and constitutes a significant mental task. An access path determination method based on image processing and numerical optimization is proposed. Fast GPU-based simulation approximation is utilized to incorporate the heat distribution including realistic cooling effects from nearby blood vessels. A user interface for intuitive exploration of the optimization results is introduced. The proposed methods are integrated into a clinical software assistant. To evaluate the suitability of the interactive optimization approach for the identification of meaningful therapy strategies, a retrospective study has been carried out. The system is able to propose clinically relevant trajectories to the target by incorporating multiple criteria. A novel method for planning of image-guided radiofrequency ablation by means of interactive access path determination based on optimization is presented. A first retrospective study indicates that the method is suited to improve the classical planning of RFA.

  20. Centromere pairing by a plasmid-encoded type I ParB protein

    DEFF Research Database (Denmark)

    Ringgaard, Simon; Löwe, Jan; Gerdes, Kenn

    2007-01-01

    The par2 locus of Escherichia coli plasmid pB171 encodes two trans-acting proteins, ParA and ParB, and two cis-acting sites, parC1 and parC2, to which ParB binds cooperatively. ParA is related to MinD and oscillates in helical structures and thereby positions ParB/parC-carrying plasmids regularly...

  1. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign...

  2. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign (March,...

  3. A study of the fluorescence of the rare gases excited by nuclear particles. Use of the principle for the detection of nuclear radiation by scintillation; Etude de la fluorescence des gaz rares excites par des particules nucleaires. Utilisation pour la detection des rayonnements nucleaires par scintillation

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-12-15

    In the first part is studied the properties of atoms excited by the passage of {alpha} particles through the various rare gases at atmospheric pressure. A spectral analysis of the emitted light showed that certain impurities play an important part in producing the fluorescence, and it has led to the conclusion that the light emission contains at least two components - one very short - lived due to the direct deexcitation of the rare gas, the other relatively slower due to the energy transfers to the impurity. The measurement of the life-time of the excited states has confirmed this foregoing hypothesis, the rapid part of the impulse is extremely short: less than 2,25.10{sup -9} s in the case of xenon; the slower part has a life-time depending directly on the nitrogen concentration, nitrogen being the impurity giving the largest effect in all cases. The study of rare gases under the influence of an electric field has made it possible to show that the amount of light produced by an {alpha} particle can be multiplied (by 60, for example, in a field of 600 V:cm) so that the luminescent efficiency is greater than in the case of INaTI. In the second part the characteristics of the rare gases acting as scintillators is examined, the most important property being the absence of fluorescence saturation when the intensity of the excitation incident on the gas is very large. This, together with the very short time of scintillation has made it possible to study a certain number of nuclear physical applications (heavy particle energy-measurements, kinetic studies on nuclear reactors, neutron spectroscopy). (author) [French] On etudie dans la premiere partie les proprietes des atomes excites par le passage de particules {alpha} dans les differents gaz rares a la pression atmospherique. L'etude spectrale de la lumiere emise a montre que certaines impuretes jouent un role considerable dans la fluorescence et on a ete amene a penser que l'emission de lumiere comporte au

  4. An analytical description of balanced steady-state free precession with finite radio-frequency excitation.

    Science.gov (United States)

    Bieri, Oliver

    2011-02-01

    Conceptually, the only flaw in the standard steady-state free precession theory is the assumption of quasi-instantaneous radio-frequency pulses, and 10-20% signal deviations from theory are observed for common balanced steady-state free precession protocols. This discrepancy in the steady-state signal can be resolved by a simple T(2) substitution taking into account reduced transverse relaxation effects during finite radio-frequency excitation. However, finite radio-frequency effects may also affect the transient phase of balanced steady-state free precession, its contrast or its spin-echo nature and thereby have an adverse effect on common steady-state free precession magnetization preparation methods. As a result, an in-depth understanding of finite radio-frequency effects is not only of fundamental theoretical interest but also has direct practical implications. In this article, an analytical solution for balanced steady-state free precession with finite radio-frequency pulses is derived for the transient phase (under ideal conditions) and in the steady state demonstrating that balanced steady-state free precession key features are preserved but revealing an unexpected dependency of finite radio-frequency effects on relaxation times for the transient decay. Finally, the mathematical framework reveals that finite radio-frequency theory can be understood as a generalization of alternating repetition time and fluctuating equilibrium steady-state free precession sequence schemes. Copyright © 2010 Wiley-Liss, Inc.

  5. Low power radiofrequency ablation for symptomatic microcystic lymphatic malformation of the tongue.

    Science.gov (United States)

    Ryu, Nam-Gyu; Park, Sang Kyu; Jeong, Han-Sin

    2008-11-01

    Although many head and neck surgeons agree that complete surgical excision is the treatment of choice for lymphatic malformation, the infiltrating nature of microcystic lymphatic malformations and the involvement of vital structures of the head and neck make total removal nearly impossible in most cases. Recently radiofrequency ablation was introduced for the treatment of microcystic lymphatic malformations of the oral cavity; it destroys lesion tissues at low temperature (40-70 degrees C) with minimal damage to adjacent structures. However, high energy (800-1200 J) and general anesthesia for radiofrequency ablation can hinder the easy and repetitive application of radiofrequency to patients. To overcome this limitation of radiofrequency ablation for microcystic lymphatic malformations, we used the same technique with a lower power (6 W, less than 100 J per site) radiofrequency ablation in an office-based setting under local anesthesia in a child with a microcystic lymphatic malformation of the whole tongue, that was associated with recurrent bleeding and swelling. The repetitive low power energy radiofrequency ablation of the microcystic lymphatic malformation of the tongue was safe and effective; it provided the patient with symptomatic relief without recurrence at follow-up. Therefore, our modification of radiofrequency ablation of the microcystic lymphatic malformations could be technically feasible and easily applicable; our result suggests that it can be a useful alternative treatment option to relieve symptoms from microcystic lymphatic malformation of the oral cavity.

  6. A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parS Partition

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, Barnali [University of Buffalo, The State University of New York; Gupta, Sayan [Case Western Reserve University; Urban, Volker S [ORNL; Chance, Mark [Case Western Reserve University; D' Mello, Rhijuta [Case Western Reserve University; Smith, Lauren [University of Buffalo, The State University of New York; Lyons, Kelly [University of Buffalo, The State University of New York; Gee, Jessica [University of Buffalo, The State University of New York

    2010-01-01

    Combining diverse sets of data at global (size, shape) and local (residue) scales is an emerging trend for elucidating the organization and function of the cellular assemblies. We used such a strategy, combining data from X-ray and neutron scattering with H/D-contrast variation and X-ray footprinting with mass spectrometry, to elucidate the spatial organization of the ParB-parS assembly from Mycobacterium tuberculosis. The ParB-parS participates in plasmid and chromosome segregation and condensation in predivisional bacterial cells. ParB polymerizes around the parS centromere(s) to form a higher-order assembly that serves to recruit cyto-skeletal ParA ATPases and SMC proteins for chromosome segregation. A hybrid model of the ParB-parS was built by combining and correlating computational models with experiment-derived information about size, shape, position of the symmetry axis within the shape, internal topology, DNA-protein interface, exposed surface patches, and prior knowledge. This first view of the ParB-parS leads us to propose how ParB spread on the chromosome to form a larger assembly.

  7. A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parS Partition Assembly

    Energy Technology Data Exchange (ETDEWEB)

    B Chaudhuri; S Gupta; V Urban; M Chance; R DMello; L Smith; K Lyons; J Gee

    2011-12-31

    Combining diverse sets of data at global (size, shape) and local (residue) scales is an emerging trend for elucidating the organization and function of the cellular assemblies. We used such a strategy, combining data from X-ray and neutron scattering with H/D-contrast variation and X-ray footprinting with mass spectrometry, to elucidate the spatial organization of the ParB-parS assembly from Mycobacterium tuberculosis. The ParB-parS participates in plasmid and chromosome segregation and condensation in predivisional bacterial cells. ParB polymerizes around the parS centromere(s) to form a higher-order assembly that serves to recruit cyto-skeletal ParA ATPases and SMC proteins for chromosome segregation. A hybrid model of the ParB-parS was built by combining and correlating computational models with experiment-derived information about size, shape, position of the symmetry axis within the shape, internal topology, DNA-protein interface, exposed surface patches, and prior knowledge. This first view of the ParB-parS leads us to propose how ParB spread on the chromosome to form a larger assembly.

  8. Host response biomarker in sepsis: suPAR detection.

    Science.gov (United States)

    Giamarellos-Bourboulis, Evangelos J; Georgitsi, Marianna

    2015-01-01

    Recent studies of our group have shown that suPAR may complement APACHE II score for risk assessment in sepsis. suPAR may be measured in serum of patients by an enzyme immunosorbent assay developed by Virogates (suPARnostic™). Production of suPAR from circulating neutrophils and monocytes may be assessed after isolation of neutrophils and monocytes and ex vivo culture. This is followed by measurement of suPAR in culture supernatants.

  9. Copenhagen uPAR prostate cancer (CuPCa) database

    DEFF Research Database (Denmark)

    Lippert, Solvej; Berg, Kasper D; Høyer-Hansen, Gunilla

    2016-01-01

    AIM: Urokinase plasminogen activator receptor (uPAR) plays a central role during cancer invasion by facilitating pericellular proteolysis. We initiated the prospective 'Copenhagen uPAR Prostate Cancer' study to investigate the significance of uPAR levels in prostate cancer (PCa) patients. METHODS...

  10. Les Brulures Chimiques Par Le Laurier Rose

    Science.gov (United States)

    Bakkali, H.; Ababou, M.; Nassim Sabah, T.; Moussaoui, A.; Ennouhi, A.; Fouadi, F.Z.; Siah, S.; Ihrai, H.

    2010-01-01

    Summary Le laurier rose ou Nerium oleander est un arbuste qui pousse naturellement dans les régions méditerranéennes. Au Maroc on le trouve dans les lieux humides. Il est réputé par ses risques de toxicité systémique en cas d'empoisonnement à cause de la présence de deux alcaloïdes, surtout l'oléandrine. La littérature illustre des cas d'utilisation locale des feuilles de cette plante contre la gale, les hémorroïdes et les furoncles. Nous rapportons deux cas de brûlures chimiques par le laurier rose de gravité différente. Cela doit aboutir à une information élargie de la population, ainsi qu'une réglementation stricte de sa commercialisation. PMID:21991211

  11. Les Brulures Chimiques Par Le Laurier Rose

    OpenAIRE

    Bakkali, H.; Ababou, M.; Nassim Sabah, T.; Moussaoui, A.; Ennouhi, A.; Fouadi, F.Z.; Siah, S.; Ihrai, H.

    2010-01-01

    Le laurier rose ou Nerium oleander est un arbuste qui pousse naturellement dans les régions méditerranéennes. Au Maroc on le trouve dans les lieux humides. Il est réputé par ses risques de toxicité systémique en cas d'empoisonnement à cause de la présence de deux alcaloïdes, surtout l'oléandrine. La littérature illustre des cas d'utilisation locale des feuilles de cette plante contre la gale, les hémorroïdes et les furoncles. Nous rapportons deux cas de brûlures chimiques par le laurier rose ...

  12. Deltagerinvolveret organisationsudvikling med PAR som metode

    DEFF Research Database (Denmark)

    Sparre, Mogens

    2017-01-01

    resistant to change. The quite widespread narrative of resistance to change, is believed to originate from the many top-down driven change projects implemented by the top management or/and external consultants. Is it possible to create a desired change in the form of the inter-subjective perception building......When a leader wants to initiate or influence some necessary changes in the organization, he must be aware of the fact that the subjects that form the organization create their own meaning about actions the manager wants implemented. This article confronts the assumption that people are by nature...... about the organization in an management group with a Participatory Action Research (PAR) case study? The article deals with a Phenomenological case study, where the researcher, with a PAR approach method, creates a research design with the purpose to influence the participant’s “Subjective perception...

  13. [Ambroise Paré in French literature].

    Science.gov (United States)

    Dumaitre, P

    1995-01-01

    The 16th century by its passionate side has been the favourite one of authors of historical novels in which among the heroes of "cloak and dagger stories" appears sometime Ambroise Paré. Alexandre Dumas (the father) has shown him at the court of Charles IX in La Reine Margot (1845) where he does not however play a great role. On the contrary, Balzac in Le Martyr calviniste (1842) has given him a capital part close to the dying François II, whom he intended to trepanize but had to give up this idea as a consequence of the opposition of the queen-mother Catherine de Médicis. In the present century, Robert Merle in Paris ma bonne ville (Fortune de France, 3, 1980) shows Paré at the time of the Saint Barthélemy.

  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/m2) showed no damage. Statistical analysis demonstrated that electromagnetic radiation from mobile phone masts is harmful for trees. These results are consistent with the fact that

  15. étude par AFM dynamique.

    African Journals Online (AJOL)

    user

    Ces forces oscillatoires de solvatation sont carac- térisées par une augmentation en amplitude lorsque la distance de confinement diminue (en tendant vers zéro), la périodicité des oscillations étant approximativement égales au diamètre des molécules du liquide confiné. Dans ce travail, nous sommes partis des récents ...

  16. Proteinase-activated receptors (PARs) as targets for antiplatelet therapy.

    Science.gov (United States)

    Cunningham, Margaret; McIntosh, Kathryn; Bushell, Trevor; Sloan, Graeme; Plevin, Robin

    2016-04-15

    Since the identification of the proteinase-activated receptor (PAR) family as mediators of serine protease activity in the 1990s, there has been tremendous progress in the elucidation of their pathophysiological roles. The development of drugs that target PARs has been the focus of many laboratories for the potential treatment of thrombosis, cancer and other inflammatory diseases. Understanding the mechanisms of PAR activation and G protein signalling pathways evoked in response to the growing list of endogenous proteases has yielded great insight into receptor regulation at the molecular level. This has led to the development of new selective modulators of PAR activity, particularly PAR1. The mixed success of targeting PARs has been best exemplified in the context of inhibiting PAR1 as a new antiplatelet therapy. The development of the competitive PAR1 antagonist, vorapaxar (Zontivity), has clearly shown the value in targeting PAR1 in acute coronary syndrome (ACS); however the severity of associated bleeding with this drug has limited its use in the clinic. Due to the efficacy of thrombin acting via PAR1, strategies to selectively inhibit specific PAR1-mediated G protein signalling pathways or to target the second thrombin platelet receptor, PAR4, are being devised. The rationale behind these alternative approaches is to bias downstream thrombin activity via PARs to allow for inhibition of pro-thrombotic pathways but maintain other pathways that may preserve haemostatic balance and improve bleeding profiles for widespread clinical use. This review summarizes the structural determinants that regulate PARs and the modulators of PAR activity developed to date. © 2016 Authors; published by Portland Press Limited.

  17. Protein adsorption enhanced radio-frequency heating of silica nanoparticles.

    Science.gov (United States)

    Wosik, Jarek; Pande, Rohit; Xie, Leiming; Ketharnath, Dhivya; Srinivasan, Srimeenakshi; Godin, Biana

    2013-07-22

    Measurements of specific-absorption-rate (SAR) of silica 30, 50, and 100 nm nanoparticles (NP) suspended in water were carried out at 30 MHz in 7 kV/m radio-frequency (rf) electric field. Size dependent, NP-suspension interface related heating of silica NP was observed. To investigate a possible mechanism of heating, bovine serum albumin was adsorbed on the surface of silica NPs in suspension. It resulted in significant enhancement of SAR when compared to bare silica NPs. A calorimetric and rf loss model was used to calculate effective conductivity of silica NP with/without adsorbed albumin as a function of silica size and albumin concentration.

  18. Intractable hemifacial spasm treated by pulsed radiofrequency treatment.

    Science.gov (United States)

    Park, Hae Lang; Lim, Seung Mo; Kim, Tae Hwa; Kang, Kyung Ho; Kang, Hyun; Jung, Yong Hun; Baek, Chong Wha; Woo, Young Cheol; Kim, Jin Yun; Koo, Gill Hoi; Shin, Hwa Yong

    2013-01-01

    Hemifacial spasm is defined as unilateral, involuntary, irregular twitching of all or parts of the muscles innervated by facial nerves. Here, we present a case of recurrent hemifacial spasm after microvascular decompression (MVD) treated with pulsed radiofrequency (PRF) treatment with good results. A 35-year-old woman suffered from recurrent hemifacial spasm after MVD that was refractory to medical treatment and botulinum toxin injections. We attempted a left facial nerve block twice. Then, we applied PRF at a maximum temperature of 42℃ for 120 sec. Some response was observed, so we applied PRF two additional times. The frequency of twitch decreased from 3-4 Hz to hemifacial spasm and has fewer complications and is less invasive compared with those of surgery.

  19. Effects of radiofrequency hyperthermia on the healthy canine cornea

    Energy Technology Data Exchange (ETDEWEB)

    Glaze, M.B.; Turk, M.A.

    1986-04-01

    Radiofrequency hyperthermia was used to induce axial corneal lesions in the eyes of 10 dogs. Clinical observations were continued for up to 6 months, using biomicroscopy and indirect ophthalmoscopy. Eyes were harvested at intervals for light and electron microscopic evaluation. Clinical alterations included immediate corneal opacification and epithelial disruption at the site of electrode contact. Ulcerative keratitis persisted for 4 to 6 days, accompanied by anterior uveitis. Additional corneal changes included stromal thinning, edema, and vascularization. Final evaluation revealed negligible alterations in corneal contour or clarity 6 months after treatment. Microscopically, epithelial and superficial stromal necrosis preceded epithelial loss. Stromal alterations included edema (associated with focal endothelial detachments), vascularization, and inflammatory cell infiltration. Recovery was characterized by keratocytic hyperplasia and hypertrophy, epithelial proliferation, and stromal condensation.

  20. Characteristics of Radio-Frequency Circuits Utilizing Ferroelectric Capacitors

    Science.gov (United States)

    Eskridge, Michael; Gui, Xiao; MacLeod, Todd; Ho, Fat D.

    2011-01-01

    Ferroelectric capacitors, most commonly used in memory circuits and variable components, were studied in simple analog radio-frequency circuits such as the RLC resonator and Colpitts oscillator. The goal was to characterize the RF circuits in terms of frequency of oscillation, gain, etc, using ferroelectric capacitors. Frequencies of oscillation of both circuits were measured and studied a more accurate resonant frequency can be obtained using the ferroelectric capacitors. Many experiments were conducted and data collected. A model to simulate the experimental results will be developed. Discrepancies in gain and frequency in these RF circuits when conventional capacitors are replaced with ferroelectric ones were studied. These results will enable circuit designers to anticipate the effects of using ferroelectric components in their radio- frequency applications.

  1. Radio-frequency ion deflector for mass separation

    Energy Technology Data Exchange (ETDEWEB)

    Schlösser, Magnus, E-mail: magnus.schloesser@googlemail.com; Rudnev, Vitaly; Ureña, Ángel González, E-mail: laseres@pluri.ucm.es [Unidad de Láseres y Haces Moleculares, Instituto Plurisdisciplinar, Universidad Complutense de Madrid, Madrid 28040 (Spain)

    2015-10-15

    Electrostatic cylindrical deflectors act as energy analyzer for ion beams. In this article, we present that by imposing of a radio-frequency modulation on the deflecting electric field, the ion transmission becomes mass dependent. By the choice of the appropriate frequency, amplitude, and phase, the deflector can be used as mass filter. The basic concept of the new instrument as well as simple mathematic relations are described. These calculations and further numerical simulations show that a mass sensitivity is achievable. Furthermore, we demonstrate the proof-of-principle in experimental measurements, compare the results to those of from a 1 m linear time-of-flight spectrometer, and comment on the mass resolution of the method. Finally, some potential applications are indicated.

  2. Drone based measurement system for radiofrequency exposure assessment.

    Science.gov (United States)

    Joseph, Wout; Aerts, Sam; Vandenbossche, Matthias; Thielens, Arno; Martens, Luc

    2016-03-10

    For the first time, a method to assess radiofrequency (RF) electromagnetic field (EMF) exposure of the general public in real environments with a true free-space antenna system is presented. Using lightweight electronics and multiple antennas placed on a drone, it is possible to perform exposure measurements. This technique will enable researchers to measure three-dimensional RF-EMF exposure patterns accurately in the future and at locations currently difficult to access. A measurement procedure and appropriate measurement settings have been developed. As an application, outdoor measurements are performed as a function of height up to 60 m for Global System for Mobile Communications (GSM) 900 MHz base station exposure. Bioelectromagnetics. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. The biophysics of renal sympathetic denervation using radiofrequency energy.

    Science.gov (United States)

    Patel, Hitesh C; Dhillon, Paramdeep S; Mahfoud, Felix; Lindsay, Alistair C; Hayward, Carl; Ernst, Sabine; Lyon, Alexander R; Rosen, Stuart D; di Mario, Carlo

    2014-05-01

    Renal sympathetic denervation is currently performed in the treatment of resistant hypertension by interventionists who otherwise do not typically use radiofrequency (RF) energy ablation in their clinical practice. Adequate RF lesion formation is dependent upon good electrode-tissue contact, power delivery, electrode-tissue interface temperature, target-tissue impedance and the size of the catheter's active electrode. There is significant interplay between these variables and hence an appreciation of the biophysical determinants of RF lesion formation is required to provide effective and safe clinical care to our patients. In this review article, we summarize the biophysics of RF ablation and explain why and how complications of renal sympathetic denervation may occur and discuss methods to minimise them.

  4. 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.

  5. Cardiac Radiofrequency Ablation: A Clinical Update for Nurses.

    Science.gov (United States)

    Shoulders, Bridget; Mauriello, Jillian; Shellman, Tamika; Follett, Corrinne

    2016-01-01

    The field of electrophysiology (EP) has rapidly evolved from a focus on diagnostic procedures to an emphasis on interventions. Many cardiac arrhythmias traditionally treated with antiarrhythmic agents, cardioversion, or cardiac surgery are now routinely cured with cardiac ablation. To optimally manage the care of cardiac ablation patients, it is essential that nurses have an understanding of the EP procedures and related nursing implications. There are extensive evidence-based resources available in the medical literature; however, there are limited publications geared toward nurses caring for cardiac ablation patients.This article provides an overview of EP diagnostic and cardiac radio-frequency ablation procedures for select atrial and ventricular tachyarrhythmias. Evidence-based nursing practices related to postprocedure care will be addressed. The objective of this article is to increase nurses' knowledge of common cardiac ablation procedures and the nursing management of the patient postprocedure.

  6. The genotoxic effect of radiofrequency waves on mouse brain.

    Science.gov (United States)

    Karaca, Emin; Durmaz, Burak; Aktug, Huseyin; Altug, Huseyin; Yildiz, Teoman; Guducu, Candan; Irgi, Melis; Koksal, Mehtap Gulcihan Cinar; Ozkinay, Ferda; Gunduz, Cumhur; Cogulu, Ozgur

    2012-01-01

    Concerns about the health effects of radiofrequency (RF) waves have been raised because of the gradual increase in usage of cell phones, and there are scientific questions and debates about the safety of those instruments in daily life. The aim of this study is to evaluate the genotoxic effects of RF waves in an experimental brain cell culture model. Brain cell cultures of the mice were exposed to 10.715 GHz with specific absorbtion rate (SAR) 0.725 W/kG signals for 6 h in 3 days at 25°C to check for the changes in the micronucleus (MNi) assay and in the expression of 11 proapoptotic and antiapoptotic genes. It was found that MNi rate increased 11-fold and STAT3 expression decreased 7-fold in the cell cultures which were exposed to RF. Cell phones which spread RF may damage DNA and change gene expression in brain cells.

  7. The Low-Frequency Environment of the Murchison Widefield Array: Radio-Frequency Interference Analysis and Mitigation

    Science.gov (United States)

    Offringa, A. R.; Wayth, R. B.; Hurley-Walker, N.; Kaplan, D. L.; Barry, N.; Beardsley, A. P.; Bell, M. E.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Callingham, J. R.; Cappallo, R. J.; Carroll, P.; Deshpande, A. A.; Dillon, J. S.; Dwarakanath, K. S.; Ewall-Wice, A.; Feng, L.; For, B.-Q.; Gaensler, B. M.; Greenhill, L. J.; Hancock, P.; Hazelton, B. J.; Hewitt, J. N.; Hindson, L.; Jacobs, D. C.; Johnston-Hollitt, M.; Kapińska, A. D.; Kim, H.-S.; Kittiwisit, P.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Morgan, J.; Neben, A. R.; Oberoi, D.; Ord, S. M.; Paul, S.; Pindor, B.; Pober, J. C.; Prabu, T.; Procopio, P.; Riding, J.; Udaya Shankar, N.; Sethi, S.; Srivani, K. S.; Staveley-Smith, L.; Subrahmanyan, R.; Sullivan, I. S.; Tegmark, M.; Thyagarajan, N.; Tingay, S. J.; Trott, C. M.; Webster, R. L.; Williams, A.; Williams, C. L.; Wu, C.; Wyithe, J. S.; Zheng, Q.

    2015-03-01

    The Murchison Widefield Array is a new low-frequency interferometric radio telescope built in Western Australia at one of the locations of the future Square Kilometre Array. We describe the automated radio-frequency interference detection strategy implemented for the Murchison Widefield Array, which is based on the aoflagger platform, and present 72-231 MHz radio-frequency interference statistics from 10 observing nights. Radio-frequency interference detection removes 1.1% of the data. Radio-frequency interference from digital TV is observed 3% of the time due to occasional ionospheric or atmospheric propagation. After radio-frequency interference detection and excision, almost all data can be calibrated and imaged without further radio-frequency interference mitigation efforts, including observations within the FM and digital TV bands. The results are compared to a previously published Low-Frequency Array radio-frequency interference survey. The remote location of the Murchison Widefield Array results in a substantially cleaner radio-frequency interference environment compared to Low-Frequency Array's radio environment, but adequate detection of radio-frequency interference is still required before data can be analysed. We include specific recommendations designed to make the Square Kilometre Array more robust to radio-frequency interference, including: the availability of sufficient computing power for radio-frequency interference detection; accounting for radio-frequency interference in the receiver design; a smooth band-pass response; and the capability of radio-frequency interference detection at high time and frequency resolution (second and kHz-scale respectively).

  8. TREATMENT OF LUMBAR HERNIAS BY ENDOSCOPIC NUCLEOPLASTY WITH RADIOFREQUENCY

    Directory of Open Access Journals (Sweden)

    Heber Humberto Alfaro Pachicano

    2016-03-01

    Full Text Available ABSTRACT Objective: To evaluate the postoperative outcomes of minimally invasive technique for treating lumbar disc herniation in patients undergoing percutaneous endoscopic nucleoplasty with radiofrequency in the center of minimally invasive procedures Veracruz (CEMIVER of the HRAEV.. Methods: A descriptive, comparative, ambispective and longitudinal study. The clinical records of patients who underwent herniated disc surgery were reviewed from March 2010 to March 2015. Inclusion criteria were individuals of both sexes, aged 18-65 years, with disc herniation diagnosis by MRI, evocative discography (pain and clinical evaluation. The variables were analyzed by VAS, Oswestry disability index for functional assessment and Macnab criteria for modified retrospective cross clinical classification. Results: 161 patients were included, 81 female and 80 male, aged between 18 and 65 years with severe (83.8% and moderate (16.2% disability according to the Oswestry disability index; the total of excellent results was 83.8%, 9.5% were good, 4.8% were median and 1.9% were poor results, according to the Macnab criteria; the average time of surgery was 84 minutes per procedure, and the postoperative average bleeding was 65 ml. Of the total, 87.4% of the patients were on an outpatient basis and 7.6% had a short hospital stay.. Conclusion: It was found that percutaneous endoscopic nucleoplasty with radiofrequency technique is a procedure that offers great benefits for patients with lumbar disc herniation, including performing it under local anesthesia, with clear visualization of the surgical field, minimal pain, little bleeding, shorter operative time, does not cause instability of anatomical structures and has minimal rate of complications.

  9. Midterm outcome of radiofrequency thermal ablation for symptomatic uterine myomas.

    Science.gov (United States)

    Ghezzi, Fabio; Cromi, Antonella; Bergamini, Valentino; Scarperi, Stefano; Bolis, Pierfrancesco; Franchi, Massimo

    2007-11-01

    Over the past decade an increasing demand for uterine-sparing treatment to manage symptomatic uterine myomas has become apparent in women's health care. A preliminary report showed that radiofrequency ablation (RFA) of uterine fibroids under laparoscopic guidance was a safe and effective minimally invasive approach with encouraging short-term results. The purpose of this study was to evaluate the midterm outcomes of radiofrequency ablation (RFA) of uterine myomas in terms of durability of symptom control and level of health-related quality of life. Consecutive women with symptomatic uterine myomas, no plans for future pregnancy, and who declined hysterectomy were offered RFA ablation of uterine fibroids under laparoscopic guidance. Only 25 patients who completed at least the one-year follow-up assessment were included in the study group. Follow-up evaluations were scheduled at 1, 3, 6, 9, and 12 months and thereafter annually following the procedure. Improvement in myoma-related symptoms and impact on quality of life were assessed using a validated questionnaire (UFS-QOL). The median number of myomas treated per patient was 1 (range = 1-3). The median baseline volume of the dominant myoma was 76.8 cm3 (range = 14.8-332.8). No intraoperative or postoperative complications occurred. The median follow-up time was 24 months, with nine women completing three years of follow-up. The median reduction in myoma volume was 68.8% and 77.9% at six months and one year, respectively. No further change in fibroid size was observed at two years and three years. One year after the procedure, one woman (4%) underwent hysterectomy for recurrence of fibroid-related symptoms. Quality-of-life measures showed significant and durable improvement compared with baseline. RFA of symptomatic fibroids seems a valuable alternative to major surgery, with durable symptom relief for most patients and a low chance of recurrence at midterm.

  10. Successful treatment of erythematotelangiectatic rosacea with pulsed light and radiofrequency.

    Science.gov (United States)

    Taub, Amy Forman; Devita, Erin C

    2008-05-01

    Many laser and light devices have reported to be successful in the treatment of the flushing, background erythema, and telangiectasias that characterize erythematotelangiectatic rosacea including pulsed dye laser, potassium titanyl phosphate, intense pulsed light, and dual-wavelength lasers. A technology called ELOS (electro-optical synergy) combines pulsed light or laser with bipolar radiofrequency. This combination, developed in 2000, was based on the premise that these two forms of energy could be synergistic. One such device (Aurora SRA-skin-rejuvenation advanced handpiece, Syneron Medical Ltd., Yokneam, Israel) has a light spectrum of 470 to 980nm, energy up to 45J/cm(2), and a range of radiofrequency energy of 5 to 25J/cm(3) and is indicated for the treatment of vascular and pigmented lesions. We attempted to quantify the improvement of moderate-to-severe type-1 rosacea after three and five full-face treatments with this modality. Twenty-one patients with moderate-to-severe rosacea underwent five monthly full-face treatments with this device. The patients were evaluated with high-resolution photographs (Canfield Visia CR, Canfield, Fairfield, New Jersey) and self-evaluated via the National Rosacea Society's official "Scorecard." Erythema and telangiectasia (physician assessed) as well as flushing and global status (patient assessed) achieved improvement that was statistically significant. Five treatments were no more effective than three, although the photographs reveal subtle improvements. There were no significant adverse events. The results of this study suggest that the combination of optical and RF energies is effective for the treatment of rosacea. ELOS, as well as other vascular-focused lasers and light sources, provides an important treatment option for patients who fail medical therapy, reach a plateau in their response to medical therapy, or wish to avoid chronic oral therapy.

  11. Stereotactic Radiofrequency Ablation for Metastatic Melanoma to the Liver

    Energy Technology Data Exchange (ETDEWEB)

    Bale, Reto, E-mail: reto.bale@i-med.ac.at; Schullian, Peter [Medical University Innsbruck, Department of Radiology, Section of Interventional Oncology - Microinvasive Therapy (SIP) (Austria); Schmuth, Matthias [Medical University Innsbruck, Department of Dermatology (Austria); Widmann, Gerlig; Jaschke, Werner [Medical University Innsbruck, Department of Radiology, Section of Interventional Oncology - Microinvasive Therapy (SIP) (Austria); Weinlich, Georg [Medical University Innsbruck, Department of Dermatology (Austria)

    2016-08-15

    PurposeTo evaluate the outcome of patients with melanoma liver metastasis treated with stereotactic radiofrequency ablation (SRFA).Material and MethodFollowing IRB approval, a retrospective evaluation of the treatment of 20 patients with 75 melanoma liver metastases was performed.ResultsA median number of 2 lesions (range 1–14) per patient with a median size of 1.7 cm (range 0.5–14.5 cm) were treated. 67 lesions were <3 cm (89.3 %) and 8 lesions were >3 cm (10.7 %). Per patient a median of 1 ablation session was performed (range: 1–4) totaling 34 sessions. There were no procedure-related deaths and all major complications (n = 3) could be easily treated by pleural drainages. The primary and secondary success rates were 89.3 and 93.3 %, respectively. The overall local recurrence rate was 13.3 %. Four of ten local recurrences were re-treated successfully by SRFA. During follow-up, 9/20 patients developed extrahepatic metastatic disease and 10/20 had liver recurrence at any location. The median OS from the date of SRFA was 19.3 months, with an OS of 64, 41, and 17 % at 1, 3, and 5 years, with no significant difference for patients with cutaneous and ocular melanoma. The median DFS after SRFA for all 20 patients was 9.5 months, with 37, 9, and 0 % at 1, 3, and 5 years.ConclusionsDue to the high local curative potential and the promising long-term survival rates associated with minimal morbidity and mortality, radiofrequency ablation seems to be an attractive alternative to resection in patients with melanoma liver metastases.

  12. Regulatory cross-talk in the double par locus of plasmid pB171

    DEFF Research Database (Denmark)

    Ringgaard, Simon; Ebersbach, Gitte; Borch, Jonas

    2007-01-01

    The double par locus of Escherichia coli virulence factor pB171 consists of two adjacent and oppositely oriented par loci of different types, called par1 and par2. par1 encodes an actin ATPase (ParM), and par2 encodes an oscillating, MinD-like ATPase (ParA). The par loci share a central cis-actin...... well with the observed transcriptional regulation of the par operons in vivo and in vitro. Integration host factor (IHF) was identified as a novel factor involved in par2-mediated plasmid partitioning....

  13. Diagnosis of Parietaria judaica pollen allergy using natural and recombinant Par j 1 and Par j 2 allergens.

    Science.gov (United States)

    González-Rioja, R; Ferrer, A; Arilla, M C; Ibarrola, I; Viguera, A R; Andreu, C; Martínez, A; Asturias, J A

    2007-02-01

    Parietaria judaica pollen is one of the main causes of allergic diseases in the Mediterranean area and contains two major allergens, called Par j 1 and Par j 2. To evaluate the diagnostic potential of natural and recombinant forms of Par j 1 and Par j 2 in comparison with standardized P. judaica pollen extract. Thirty patients allergic to P. judaica pollen and 15 control patients were investigated. Skin prick tests and determination of specific IgE levels were performed with commercial P. judaica extract, natural Par j 1 and Par j 2, and recombinant forms of both allergens expressed in P. pastoris. The whole group of patients with allergy to P. judaica had a positive skin test reaction to purified nPar j 1-Par j 2 and rPar j 2 at 5 microg/mL, and no false-positive reactions were detected. Natural and recombinant Par j 1 and Par j 2 showed no significantly different responses in skin tests compared with P. judaica extract. A high correlation was found between the serum-specific IgE levels to P. judaica extract vs. natural (R=0.996; P<0.001) and recombinant allergens (R=0.887 and 0.982 for rPar j 1 and rPar j 2, respectively; P<0.001). rPar j 2 displayed a 100% sensitivity and specificity among P. judaica-allergic patients. In vivo and in vitro diagnosis of P. judaica pollen allergy could be simplified using rPar j 2. This protein showed comparable IgE response and skin prick reactivity with those produced by P. judaica pollen extract.

  14. Radiofrequency ablation in an infant with recurrent supraventricular tachycardia and cyanosis

    Directory of Open Access Journals (Sweden)

    Vora Amit

    2009-01-01

    Full Text Available We report an unusual presentation of supraventricular tachycardia, in an infant, with cyanosis. The child had atrial septal defect with hypoplastic right ventricle. Radiofrequency ablation was performed in view of drug resistant SVT

  15. Radiofrequency (thermal) ablation versus no intervention or other interventions for hepatocellular carcinoma

    DEFF Research Database (Denmark)

    Weis, Sebastian; Franke, Annegret; Mössner, Joachim

    2013-01-01

    Hepatocellular carcinoma is the fifth most common cancer worldwide. Percutaneous interventional therapies, such as radiofrequency (thermal) ablation (RFA), have been developed for early hepatocellular carcinoma. RFA competes with other interventional techniques such as percutaneous ethanol...

  16. Definitions and methodology for the grayscale and radiofrequency intravascular ultrasound and coronary angiographic analyses

    NARCIS (Netherlands)

    A. Maehara (Akiko); E. Cristea (Ecaterina); G.S. Mintz (Gary); A.J. Lansky (Alexandra); O. Dressler (Ovidiu); S. Biro (Sinan); B. Templin (Barry); R. Virmani (Renu); B. de Bruyne (Bernard); P.W.J.C. Serruys (Patrick); G.W. Stone (Gregg)

    2012-01-01

    textabstractObjectives: In a prospective study of the natural history of coronary atherosclerosis using angiography and grayscale and radiofrequency intravascular ultrasound (IVUS)virtual histology (VH), larger plaque burden, smaller luminal area, and plaque composition thin-cap fibroatheroma

  17. Radio-frequency transparent demodulation for broadband hybrid wireless-optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Sambaraju, Rakesh; Alemany, Ruben

    2010-01-01

    A novel demodulation technique which is transparent to radio-frequency (RF) carrier frequency is presented and experimentally demonstrated for multigigabit wireless signals. The presented demodulation technique employs optical single-sideband filtering, coherent detection, and baseband digital...

  18. Radiofrequency (mobile telephones) Exposures and Health Risks: Findings and Controversies - Linet

    Science.gov (United States)

    Radiofrequency (mobile telephones) Exposures and Health Risks: Findings and Controversies by Dr. Martha Linet - part of the Radiation Epidemiology and Dosimetry Course on the health effects of radiation exposure

  19. Thermometry during coblation and radiofrequency ablation of vertebral metastases: a cadaver study

    National Research Council Canada - National Science Library

    Groetz, Simon F; Birnbaum, Klaus; Meyer, Carsten; Strunk, Holger; Schild, Hans H; Wilhelm, Kai E

    2013-01-01

    To evaluate safety of coblation of simulated lytic metastases in human cadaveric vertebral bodies by measuring heat distribution during thermal tissue ablation and comparing it to radiofrequency ablation (RFA...

  20. WindSat Radio-Frequency Interference Signature and Its Identification Over Land and Ocean

    National Research Council Canada - National Science Library

    Li, L; Gaiser, Peter W; Bettenhausen, Michael H; Johnston, William

    2006-01-01

    Radio-frequency interference (RFI) in the spaceborne multichannel radiometer data of WindSat and the Advanced Microwave Scanning Radiometer EOS is currently being detected using a spectral difference technique...

  1. Papillary thyroid carcinoma treated with radiofrequency ablation in a patient with hypertrophic cardiomyopathy: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jian Yi; Liu, Xiao Sun; Zhang, Qing; Hong, Yan Yun; Song, Bin; Teng, Xiao Dong; Yu, Ji Ren [The First Affiliated Hospital, Medical College, Zhejiang University, Hangzhou (China)

    2016-07-15

    Standard therapy has not been established for thyroid cancer when a thyroidectomy is contraindicated due to systemic disease. Herein, we reported a patient who had hypertrophic cardiomyopathy and papillary thyroid carcinoma treated by radiofrequency ablation because of inability to tolerate a thyroidectomy. Radiofrequency ablation can be used to treat thyroid cancer when surgery is not feasible, although the long-term outcome needs further observation.

  2. Papillary Thyroid Carcinoma Treated with Radiofrequency Ablation in a Patient with Hypertrophic Cardiomyopathy: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jianyi; Liu, Xiaosun; Zhang, Qing; Hong, Yanyun; Song, Bin [Department of Gastrointestinal and Thyroid Surgery, The First Affiliated Hospital, Medical College, Zhejiang University, Hangzhou 310003 (China); Teng, Xiaodong [Department of Pathology, The First Affiliated Hospital, Medical College, Zhejiang University, Hangzhou 310003 (China); Yu, Jiren [Department of Gastrointestinal and Thyroid Surgery, The First Affiliated Hospital, Medical College, Zhejiang University, Hangzhou 310003 (China)

    2016-11-01

    Standard therapy has not been established for thyroid cancer when a thyroidectomy is contraindicated due to systemic disease. Herein, we reported a patient who had hypertrophic cardiomyopathy and papillary thyroid carcinoma treated by radiofrequency ablation because of inability to tolerate a thyroidectomy. Radiofrequency ablation can be used to treat thyroid cancer when surgery is not feasible, although the long-term outcome needs further observation.

  3. Bipolar radiofrequency-induced thermotherapy of great saphenous vein: Our initial experience

    Directory of Open Access Journals (Sweden)

    Venkatesh Kasi

    2012-01-01

    Full Text Available The incidence of varicose veins in lower limbs is increasing in the Indian subcontinent. With the advent of radiofrequency ablation (RFA, an effective minimally invasive technique is now available to treat varicose veins. RFA can be performed with either unipolar or bipolar probes. We present a simple technique for bipolar radiofrequency-induced thermotherapy of the great saphenous vein. This can be a safe and effective alternative to surgical procedures.

  4. A single parS sequence from the cluster of four sites closest to oriC is necessary and sufficient for proper chromosome segregation in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Paulina Jecz

    Full Text Available Among the mechanisms that control chromosome segregation in bacteria are highly-conserved partitioning systems comprising three components: ParA protein (a deviant Walker-type ATPase, ParB protein (a DNA-binding element and multiple cis-acting palindromic centromere-like sequences, designated parS. Ten putative parS sites have been identified in the P. aeruginosa PAO1 genome, four localized in close proximity of oriC and six, diverged by more than one nucleotide from a perfect palindromic sequence, dispersed along the chromosome. Here, we constructed and analyzed P. aeruginosa mutants deprived of each single parS sequence and their different combinations. The analysis included evaluation of a set of phenotypic features, chromosome segregation, and ParB localization in the cells. It was found that ParB binds specifically to all ten parS sites, although with different affinities. The P. aeruginosa parS mutant with all ten parS sites modified (parSnull is viable however it demonstrates the phenotype characteristic for parAnull or parBnull mutants: slightly slower growth rate, high frequency of anucleate cells, and defects in motility. The genomic position and sequence of parS determine its role in P. aeruginosa biology. It transpired that any one of the four parS sites proximal to oriC (parS1 to parS4, which are bound by ParB with the highest affinity, is necessary and sufficient for the parABS role in chromosome partitioning. When all these four sites are mutated simultaneously, the strain shows the parSnull phenotype, which indicates that none of the remaining six parS sites can substitute for these four oriC-proximal sites in this function. A single ectopic parS2 (inserted opposite oriC in the parSnull mutant facilitates ParB organization into regularly spaced condensed foci and reverses some of the mutant phenotypes but is not sufficient for accurate chromosome segregation.

  5. A single parS sequence from the cluster of four sites closest to oriC is necessary and sufficient for proper chromosome segregation in Pseudomonas aeruginosa.

    Science.gov (United States)

    Jecz, Paulina; Bartosik, Aneta A; Glabski, Krzysztof; Jagura-Burdzy, Grazyna

    2015-01-01

    Among the mechanisms that control chromosome segregation in bacteria are highly-conserved partitioning systems comprising three components: ParA protein (a deviant Walker-type ATPase), ParB protein (a DNA-binding element) and multiple cis-acting palindromic centromere-like sequences, designated parS. Ten putative parS sites have been identified in the P. aeruginosa PAO1 genome, four localized in close proximity of oriC and six, diverged by more than one nucleotide from a perfect palindromic sequence, dispersed along the chromosome. Here, we constructed and analyzed P. aeruginosa mutants deprived of each single parS sequence and their different combinations. The analysis included evaluation of a set of phenotypic features, chromosome segregation, and ParB localization in the cells. It was found that ParB binds specifically to all ten parS sites, although with different affinities. The P. aeruginosa parS mutant with all ten parS sites modified (parSnull) is viable however it demonstrates the phenotype characteristic for parAnull or parBnull mutants: slightly slower growth rate, high frequency of anucleate cells, and defects in motility. The genomic position and sequence of parS determine its role in P. aeruginosa biology. It transpired that any one of the four parS sites proximal to oriC (parS1 to parS4), which are bound by ParB with the highest affinity, is necessary and sufficient for the parABS role in chromosome partitioning. When all these four sites are mutated simultaneously, the strain shows the parSnull phenotype, which indicates that none of the remaining six parS sites can substitute for these four oriC-proximal sites in this function. A single ectopic parS2 (inserted opposite oriC in the parSnull mutant) facilitates ParB organization into regularly spaced condensed foci and reverses some of the mutant phenotypes but is not sufficient for accurate chromosome segregation.

  6. Regulatory cross-talk in the double par locus of plasmid pB171

    DEFF Research Database (Denmark)

    Ringgaard, Simon; Ebersbach, Gitte; Borch, Jonas

    2007-01-01

    The double par locus of Escherichia coli virulence factor pB171 consists of two adjacent and oppositely oriented par loci of different types, called par1 and par2. par1 encodes an actin ATPase (ParM), and par2 encodes an oscillating, MinD-like ATPase (ParA). The par loci share a central cis......-acting region of approximately 200 bp, called parC1, located between the two par loci. An additional cis-acting region, parC2, is located downstream of the parAB operon of par2. Here we show that ParR of par1 and ParB of par2 bind cooperatively to unrelated sets of direct repeats in parC1 to form the cognate...... partition and promoter repression complexes. Surprisingly, ParB repressed transcription of the noncognate par operon, indicating cross-talk and possibly epistasis between the two systems. The par promoters, P1 and P2, affected each other negatively. The DNA binding activities of ParR and ParB correlated...

  7. A Fractional Bipolar Radiofrequency Device Combined with a Bipolar Radiofrequency and Infrared Light Treatment for Improvement in Facial Wrinkles and Overall Skin Tone and Texture.

    Science.gov (United States)

    Gold, Alan H; Pozner, Jason; Weiss, Robert

    2016-10-01

    A variety of techniques and energy-based technologies are currently utilized for the treatment of facial wrinkles. Fractional bipolar radiofrequency treatment and treatment with bipolar radiofrequency combined with infrared light have both been reported to be safe and effective for the non-invasive treatment of wrinkles and overall facial rejuvenation. A multicenter, prospective clinical trial evaluated a protocol of treatment with a device incorporating bipolar radiofrequency and infrared light followed by treatment with a fractional bipolar radiofrequency device for facial wrinkle reduction and improvement in the overall appearance of aged facial skin. Fifty-six patients with mild to moderate facial wrinkles received three full-face treatments (forehead, nose, cheeks, periorbital, and perioral areas) at 4 to 6 week intervals and were evaluated at 12 and 24 weeks after the last treatment. Clinical photographs at baseline and follow-ups were assessed by both the investigators and patients using the Global Aesthetic Improvement scale. Treatment safety was evaluated. Study participants also completed a satisfaction and improvement questionnaire. Fitzpatrick Wrinkling and Elastosis Score was decreased significantly at three months (P wrinkles and overall facial skin appearance throughout the study, and high a degree of satisfaction with their final results. Subjects tolerated the procedures well, with only transient mild to moderate erythema and edema occurring in most patients, and without complications. A combined protocol of bipolar radiofrequency and infrared light treatment followed by fractionated bipolar radiofrequency treatment results in safe, well tolerated, and effective improvement in overall skin tone and texture and reduction of facial wrinkles. 4 Therapeutic. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

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

    Directory of Open Access Journals (Sweden)

    Yeon Jin Choi

    2012-01-01

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

  9. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  11. Comparative study between radiofrequency sinus excision and open excision in sacro-coccygeal pilonidal sinus disease.

    Science.gov (United States)

    Gupta, Pravin J

    2005-01-01

    Evaluation of outcome of pilonidal sinus excision using a radiofrequency device and comparing its results with excision and open granulation procedure. Patients with sacro-coccygeal pilonidal sinus disease (n=44) were randomly assigned to undergo either a wide excision and healing by open granulation procedure [WEG] (n=23) or a radiofrequency sinus excision [RSE] (n=21). An Ellman radiofrequency generator was used for RSE. Intra- and postoperative events and outcome data were evaluated and analyzed by Student's unpaired t test and chi(2) test. The significant differences in the two groups WEG and RSE were as follows: mean hospital stay (47 vs. 10 h, p< 0.05), period off work (29 vs. 8 days, p< 0.05), mean analgesic requirement (39 vs. 15 tablets, p< 0.05), time for complete wound healing (84 vs. 49 days, p< 0.05). At the mean follow-up of 30 months, 2 patients from the wide excision and open granulation group and one patient from the radiofrequency sinus excision group developed recurrence. These findings suggest that sinus excision with radiofrequency is a simple and swift procedure. It needs a short hospital stay and is associated with less postoperative pain and early resumption to work. As compared to excision and healing by granulation technique, the radiofrequency sinus excision procedure achieves faster wound healing and a better outcome. Copyright (c) 2005 S. Karger AG, Basel.

  12. Radiofrequency denervation for neck and back pain. A systematic review of randomized controlled trials.

    Science.gov (United States)

    Niemisto, L; Kalso, E; Malmivaara, A; Seitsalo, S; Hurri, H

    2003-01-01

    The diagnosis of cervical or lumbar zygapophyseal joint pain can only be made by using local anesthesia to block the nerves supplying the painful joint. There is a lack of effective treatment for chronic zygapophyseal joint pain or discogenic pain. Radiofrequency denervation appears to be an emerging technology, with substantial variation in its use between countries. To assess the effectiveness of radiofrequency denervation for the treatment of musculoskeletal pain disorders. We searched MEDLINE, PsycLIT, and EMBASE from start to February 2002, plus the Cochrane Library 2002, Issue 2. The references of identified articles were checked and three experts in the field of radiofrequency treatment were consulted to identify studies we might have missed. Randomized controlled trials (RCTs) of radiofrequency denervation for musculoskeletal pain disorders, with no language or date restrictions. Two reviewers selected RCTs that met predefined inclusion criteria, extracted the data, and assessed the main results and methodological quality of the selected trials, using standardized forms. Qualitative analysis was conducted to evaluate the level of scientific evidence. We found only nine articles, reporting on seven relevant RCTs. Six of the seven were considered to be high-quality. The selected trials included 275 randomized patients, 141 of whom received active treatment. One study examined cervical zygapophyseal joint pain, two cervicobrachial pain, three lumbar zygapophyseal joint pain, and one discogenic low-back pain. The study sample sizes were small, follow-up times short, and there were some deficiencies in patient selection, outcome assessments, and statistical analyses. The level of scientific evidence for the short-term effectiveness of radiofrequency denervation was limited for cervical zygapophyseal joint and cervicobrachial pain, and conflicting for lumbar zygapophyseal joint pain. There was limited evidence suggesting that intradiscal radiofrequency

  13. Ionisation D'atomes Par un Laser Carbon Dioxide Intense Par L'effet Tunnel

    Science.gov (United States)

    Xiong, Wei

    Cette these decrit des experiences d'ionisation d'atomes (Xe et K) par un laser CO_2 intense. Des spectrometres de masse et d'energie electronique ont ete developpes pour mesurer le nombre d'ions crees et l'energie des electrons acceleres par le gradient spatial du champ laser. Des details sur ces mesures sont fournis et justifies. On a mesure des energies d'electrons jusqu'a 1000eV, a une intensite de 10^{14} W/cm^2. Les mesures experimentales sont comparees avec deux types de theorie, qui decrivent le processus d'ionisation dans deux limites: l'interaction entre electron et noyau est beaucoup plus forte que celle entre electron et champ laser (processus multiphotonique), ou l'inverse (effect tunnel). Les resultats montrent que la courbe du nombre d'ions crees en fonction de l'intensite n'est pas tres sensible aux details du processus d'ionsisation. Par contre les spectres d'energie des electrons dependent fortement du processus d'ionisation, et on peut en deduire le taux d'ionisation. On trouve que la theorie multiphotonique ne fournit pas une explication satisfaisante aux resultats experimentaux, mais que la theorie de l'effet tunnel s'ajuste bien si on suppose que le seuil d'ionisation peut etre deplace legerement par le champ laser. Le deplacement necessaire du seuil est estime dans cette these, mais une explication theorique reste a trouver.

  14. Cataract surgery after pars plana vitrectomy.

    Science.gov (United States)

    Shousha, Mohamed Abou; Yoo, Sonia H

    2010-01-01

    To review recent studies and advances and their possible implications in the care of patients undergoing cataract surgery after pars plana vitrectomy. Optical biometry has shown to be superior to ultrasound biometry in vitrectomized eyes but still not achieving as good results as it does in nonvitrectomized eyes. Blue light-filter intraocular lenses, with their possible advantage of macular protection, have shown no operative or functional disadvantages in vitrectomized eyes, and thus their routine use can be justified. However, presbyopia-correcting intraocular lenses, at least at their current stage of development, generally, are still not accepted for vitrectomized eyes. Combining cataract surgery with intravitreal injections of bevacizumab or triamcinolone acetonide in patients with macular edema and cataract is advisable to avoid exacerbation of the condition and improve visual outcome. Despite the recent advances, incidences of posterior capsular opacification and retinal detachment are still considerable. Understanding ocular anatomical alterations imposed by the previous pars plana vitrectomy surgery and the underlying vitreoretinal disease will allow the surgeon to address the special challenges. Despite that, recent advances in techniques and instrumentation have improved the surgical safety and outcomes, reported complications rates are still relatively high.

  15. Wireless Chalcogenide Nanoionic-Based Radio-Frequency Switch

    Science.gov (United States)

    Nessel, James; Miranda, Felix

    2013-01-01

    A new nonvolatile nanoionic switch is powered and controlled through wireless radio-frequency (RF) transmission. A thin layer of chalcogenide glass doped with a metal ion, such as silver, comprises the operational portion of the switch. For the switch to function, an oxidizable electrode is made positive (anode) with respect to an opposing electrode (cathode) when sufficient bias, typically on the order of a few tenths of a volt or more, is applied. This action causes the metal ions to flow toward the cathode through a coordinated hopping mechanism. At the cathode, a reduction reaction occurs to form a metal deposit. This metal deposit creates a conductive path that bridges the gap between electrodes to turn the switch on. Once this conductive path is formed, no further power is required to maintain it. To reverse this process, the metal deposit is made positive with respect to the original oxidizable electrode, causing the dissolution of the metal bridge thereby turning the switch off. Once the metal deposit has been completely dissolved, the process self-terminates. This switching process features the following attributes. It requires very little to change states (i.e., on and off). Furthermore, no power is required to maintain the states; hence, the state of the switch is nonvolatile. Because of these attributes the integration of a rectenna to provide the necessary power and control is unique to this embodiment. A rectenna, or rectifying antenna, generates DC power from an incident RF signal. The low voltages and power required for the nanoionic switch control are easily generated from this system and provide the switch with a novel capability to be operated and powered from an external wireless device. In one realization, an RF signal of a specific frequency can be used to set the switch into an off state, while another frequency can be used to set the switch to an on state. The wireless, miniaturized, and nomoving- part features of this switch make it

  16. The study of thermal change by chemoport in radiofrequency hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Lee, Sun Young; Gim, Yang Soo; Kwak, Keun Tak; Yang, Myung Sik; Cha, Seok Yong [Dept. of Radiation Oncology, Chonbuk National University Hospital, Jeonju (Korea, Republic of)

    2015-12-15

    This study evaluate the thermal changes caused by use of the chemoport for drug administration and blood sampling during radiofrequency hyperthermia. 20 cm size of the electrode radio frequency hyperthermia (EHY-2000, Oncotherm KFT, Hungary) was used. The materials of the chemoport in our hospital from currently being used therapy are plastics, metal-containing epoxy and titanium that were made of the diameter 20 cm, height 20 cm insertion of the self-made cylindrical Agar phantom to measure the temperature. Thermoscope(TM-100, Oncotherm Kft, Hungary) and Sim4Life (Ver2.0, Zurich, Switzerland) was compared to the actual measured temperature. Each of the electrode measurement position is the central axis and the central axis side 1.5 cm, 0 cm(surface), 0.5 cm, 1.8 cm, 2.8 cm in depth was respectively measured. The measured temperature is 24.5 - 25.5℃, humidity is 30% - 32%. In five-minute intervals to measure the output power of 100 W, 60 min. In the electrode central axis 2.8 cm depth, the maximum temperature of the case with the unused of the chemoport, plastic, epoxy and titanium were respectively 39.51℃, 39.11℃, 38.81℃, 40.64℃, simulated experimental data were 42.20 ℃, 41.50℃, 40.70℃, 42.50℃. And in the central axis electrode side 1.5 cm depth 2.8 cm, measured data were 39.37℃, 39.32℃, 39.20℃, 39.46℃, the simulated experimental data were 42.00℃, 41.80℃, 41.20℃, 42.30℃. The thermal variations were caused by radiofrequency electromagnetic field surrounding the chemoport showed lower than in the case of unused in non-conductive plastic material and epoxy material, the titanum chemoport that made of conductor materials showed a slight differences. This is due to the metal contents in the chemoport and the geometry of the chemoport. And because it uses a low radio frequency bandwidth of the used equipment. That is, although use of the chemoport in this study do not significantly affect the surrounding tissue. That is, because the

  17. A Par-1-Par-3-Centrosome Cell Polarity Pathway and Its Tuning for Isotropic Cell Adhesion.

    Science.gov (United States)

    Jiang, Tao; McKinley, R F Andrew; McGill, Melanie A; Angers, Stephane; Harris, Tony J C

    2015-10-19

    To form regulated barriers between body compartments, epithelial cells polarize into apical and basolateral domains and assemble adherens junctions (AJs). Despite close links with polarity networks that generate single polarized domains, AJs distribute isotropically around the cell circumference for adhesion with all neighboring cells [1-3]. How AJs avoid the influence of polarity networks to maintain their isotropy has been unclear. In established epithelia, trans cadherin interactions could maintain AJ isotropy [4], but AJs are dynamic during epithelial development and remodeling [5, 6], and thus specific mechanisms may control their isotropy. In Drosophila, aPKC prevents hyper-polarization of junctions as epithelia develop from cellularization to gastrulation [7]. Here, we show that aPKC does so by inhibiting a positive feedback loop between Bazooka (Baz)/Par-3, a junctional organizer [5, 8-10], and centrosomes. Without aPKC, Baz and centrosomes lose their isotropic distributions and recruit each other to single plasma membrane (PM) domains. Surprisingly, our loss- and gain-of-function analyses show that the Baz-centrosome positive feedback loop is driven by Par-1, a kinase known to phosphorylate Baz and inhibit its basolateral localization [8, 11, 12]. We find that Par-1 promotes the positive feedback loop through both centrosome microtubule effects and Baz phosphorylation. Normally, aPKC attenuates the circuit by expelling Par-1 from the apical domain at gastrulation. The combination of local activation and global inhibition is a common polarization strategy [13-16]. Par-1 seems to couple both effects for a potent Baz polarization mechanism that is regulated for the isotropy of Baz and AJs around the cell circumference. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The PAR Proteins: Fundamental Players in Animal Cell Polarization

    OpenAIRE

    Goldstein, Bob; Macara, Ian G.

    2007-01-01

    The par genes were discovered in genetic screens for regulators of cytoplasmic partitioning in the early embryo of C. elegans, and encode six different proteins required for asymmetric cell division by the worm zygote. Some of the PAR proteins are localized asymmetrically and form physical complexes with one another. Strikingly, the PAR proteins have been found to regulate cell polarization in many different contexts in diverse animals, suggesting they form part of an ancient and fundamental ...

  19. Trapping ions from a fast beam in a radio-frequency ion trap: Exploring the energy exchange with the longitudinal radio-frequency field

    DEFF Research Database (Denmark)

    Svendsen, Annette; Lammich, Lutz; Vad Andersen, John Erik

    2013-01-01

    The possibility of injecting ions from an initially fast moving beam into a multipole radio-frequency (RF) ion trap without the use of buffer gas is described. The chosen trap geometry gives rise to an oscillating electric field along the direction of the incoming ions, and through an analytical...

  20. Heat sink effect on tumor ablation characteristics as observed in monopolar radiofrequency, bipolar radiofrequency, and microwave, using ex vivo calf liver model.

    Science.gov (United States)

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

    2015-03-01

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

  1. Operating a radio-frequency plasma source on water vapor.

    Science.gov (United States)

    Nguyen, Sonca V T; Foster, John E; Gallimore, Alec D

    2009-08-01

    A magnetically enhanced radio-frequency (rf) plasma source operating on water vapor has an extensive list of potential applications. In this work, the use of a rf plasma source to dissociate water vapor for hydrogen production is investigated. This paper describes a rf plasma source operated on water vapor and characterizes its plasma properties using a Langmuir probe, a residual gas analyzer, and a spectrometer. The plasma source operated first on argon and then on water vapor at operating pressures just over 300 mtorr. Argon and water vapor plasma number densities differ significantly. In the electropositive argon plasma, quasineutrality requires n(i) approximately = n(e), where n(i) is the positive ion density. But in the electronegative water plasma, quasineutrality requires n(i+) = n(i-) + n(e). The positive ion density and electron density of the water vapor plasma are approximately one and two orders of magnitude lower, respectively, than those of argon plasma. These results suggest that attachment and dissociative attachment are present in electronegative water vapor plasma. The electron temperature for this water vapor plasma source is between 1.5 and 4 eV. Without an applied axial magnetic field, hydrogen production increases linearly with rf power. With an axial magnetic field, hydrogen production jumps to a maximum value at 500 W and then saturates with rf power. The presence of the applied axial magnetic field is therefore shown to enhance hydrogen production.

  2. Importância da radiofrequência na oftalmologia

    Directory of Open Access Journals (Sweden)

    José Ricardo Carvalho Lima Rehder

    2013-04-01

    Full Text Available Este trabalho revisa e faz uma análise crítica da radiofrequência em oftalmologia. O aquecimento da córnea tem sido realizado desde 1889 com diferentes finalidades terapêuticas e cirúrgicas. O princípio do aquecimento da córnea causa um enrugamento do colágeno que muda a curvatura da córnea. Após a aprovação da FDA em 2004, iniciou-se um estudo multicêntrico no Brasil coordenado pela Faculdade de Medicina do ABC que resultou na análise de 258 pacientes. Como conclusão o estudo mostrou que o procedimento tem um resultado temporário e que os melhores resultados foram obtidos em pacientes entre 45 e 55 anos de idade sem correção óptica para longe. Acreditamos que o problema ainda não foi resolvido e que novas pesquisas devem ser realizadas.

  3. Percutaneous treatment of bone tumors by radiofrequency thermal ablation

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Santiago, Fernando, E-mail: ferusan@ono.com [Department of Radiology, Hospital of Traumatology (Ciudad Sanitaria Virgen de las Nieves), Carretera de Jaen SN, 18013 Granada (Spain); Mar Castellano Garcia, Maria del; Guzman Alvarez, Luis [Department of Radiology, Hospital of Traumatology (Ciudad Sanitaria Virgen de las Nieves), Carretera de Jaen SN, 18013 Granada (Spain); Martinez Montes, Jose Luis [Department of Traumatology, Hospital of Traumatology (Ciudad Sanitaria Virgen de las Nieves), Carretera de Jaen SN, 18013 Granada (Spain); Ruiz Garcia, Manuel; Tristan Fernandez, Juan MIguel [Department of Radiology, Hospital of Traumatology (Ciudad Sanitaria Virgen de las Nieves), Carretera de Jaen SN, 18013 Granada (Spain)

    2011-01-15

    We present our experience of the treatment of bone tumors with radiofrequency thermal ablation (RFTA). Over the past 4 years, we have treated 26 cases (22 benign and 4 malignant) using CT-guided RFTA. RFTA was the sole treatment in 19 cases and was combined with percutaneous cementation during the same session in the remaining seven cases. Our approach to the tumors was simplified, using a single point of entrance for both RFTA and percutaneous osteoplasty. In the benign cases, clinical success was defined as resolution of pain within 1 month of the procedure and no recurrence during the follow-up period. It was achieved in 19 out of the 21 patients in which curative treatment was attempted. The two non-resolved cases were a patient with osteoid osteoma who developed a symptomatic bone infarct after a symptom-free period of 2 months and another with femoral diaphysis osteoblastoma who suffered a pathological fracture after 8 months without symptoms. The procedure was considered clinically successful in the five cases (4 malign and 1 benign) in which palliative treatment was attempted, because there was a mean ({+-}SD) reduction in visual analogue scale (VAS) pain score from 9.0 {+-} 0.4 before the procedure to <4 during the follow-up period.

  4. Radiofrequency-dressed-state potentials for neutral atoms

    DEFF Research Database (Denmark)

    Hofferberth, S.; Lesanovsky, Igor; Fischer, B.

    2006-01-01

    Potentials for atoms can be created by external fields acting on properties such as magnetic moment, charge, polarizability, or by oscillating fields that couple internal states. The most prominent realization of the latter is the optical dipole potential formed by coupling ground and electronica......Potentials for atoms can be created by external fields acting on properties such as magnetic moment, charge, polarizability, or by oscillating fields that couple internal states. The most prominent realization of the latter is the optical dipole potential formed by coupling ground...... and electronically excited states of an atom with light. Here, we present an extensive experimental analysis of potentials derived from radiofrequency (RF) coupling of electronic ground states. The coupling is magnetic and the vector character allows the design of versatile microscopic state-dependent potential...... landscapes. Compared with standard magnetic trapping, we find no additional heating or (collisional) loss up to densities of 1015 atoms cm-3. We demonstrate robust evaporative cooling in RF potentials, which allows easy production of Bose-Einstein condensates in complex potentials. Altogether, this makes RF...

  5. Thermal modeling of lesion growth with radiofrequency ablation devices

    Directory of Open Access Journals (Sweden)

    Nguyen Uyen D

    2004-08-01

    Full Text Available Abstract Background Temperature is a frequently used parameter to describe the predicted size of lesions computed by computational models. In many cases, however, temperature correlates poorly with lesion size. Although many studies have been conducted to characterize the relationship between time-temperature exposure of tissue heating to cell damage, to date these relationships have not been employed in a finite element model. Methods We present an axisymmetric two-dimensional finite element model that calculates cell damage in tissues and compare lesion sizes using common tissue damage and iso-temperature contour definitions. The model accounts for both temperature-dependent changes in the electrical conductivity of tissue as well as tissue damage-dependent changes in local tissue perfusion. The data is validated using excised porcine liver tissues. Results The data demonstrate the size of thermal lesions is grossly overestimated when calculated using traditional temperature isocontours of 42°C and 47°C. The computational model results predicted lesion dimensions that were within 5% of the experimental measurements. Conclusion When modeling radiofrequency ablation problems, temperature isotherms may not be representative of actual tissue damage patterns.

  6. 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.

  7. Radiofrequency Ablation: A Minimally Invasive Approach in Kidney Tumor Management

    Energy Technology Data Exchange (ETDEWEB)

    Salagierski, Maciej, E-mail: maciej.salagierski@umed.lodz.pl [I Urology Department, Medical University of Lodz (Poland); Salagierski, Marek S. [II Urology Department, Medical University of Lodz (Poland)

    2010-11-17

    The management and diagnosis of renal tumors have changed significantly over the last decade. Due to advances in imaging techniques, more than 50% of kidney tumors are discovered incidentally and many of them represent an early stage lesion. This has stimulated the development of nephron-sparing surgery and of the minimally invasive treatment options including ablative techniques, i.e., radiofrequency ablation (RFA) and cryoablation. The objective of the minimally invasive approach is to preserve the renal function and to lower the perioperative morbidity. RFA involves inducing the coagulative necrosis of tumor tissue. Being probably one of the least invasive procedures in kidney tumor management, RFA may be performed percutaneously under ultrasound (US), computed tomography (CT) or magnetic resonance (MR) guidance. Most of the studies show that the RFA procedure is efficient, safe and has a low complication rate. Due to the still limited data on the oncological outcome of RFA, the indication for this intervention remains limited to selected patients with small organ-confined renal tumors and contraindication to surgery or who have a solitary kidney. The aim of our study is to review the literature on RFA of kidney tumors.

  8. Bilateral Intra-Articular Radiofrequency Ablation for Cervicogenic Headache

    Directory of Open Access Journals (Sweden)

    Charles A. Odonkor

    2017-01-01

    Full Text Available 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.

  9. Polarization image segmentation of radiofrequency ablated porcine myocardial tissue.

    Directory of Open Access Journals (Sweden)

    Iftikhar Ahmad

    Full Text Available Optical polarimetry has previously imaged the spatial extent of a typical radiofrequency ablated (RFA lesion in myocardial tissue, exhibiting significantly lower total depolarization at the necrotic core compared to healthy tissue, and intermediate values at the RFA rim region. Here, total depolarization in ablated myocardium was used to segment the total depolarization image into three (core, rim and healthy zones. A local fuzzy thresholding algorithm was used for this multi-region segmentation, and then compared with a ground truth segmentation obtained from manual demarcation of RFA core and rim regions on the histopathology image. Quantitative comparison of the algorithm segmentation results was performed with evaluation metrics such as dice similarity coefficient (DSC = 0.78 ± 0.02 and 0.80 ± 0.02, sensitivity (Sn = 0.83 ± 0.10 and 0.91 ± 0.08, specificity (Sp = 0.76 ± 0.17 and 0.72 ± 0.17 and accuracy (Acc = 0.81 ± 0.09 and 0.71 ± 0.10 for RFA core and rim regions, respectively. This automatic segmentation of parametric depolarization images suggests a novel application of optical polarimetry, namely its use in objective RFA image quantification.

  10. [Transvesical radiofrequency needle ablation on prostatic benign hyperplasia].

    Science.gov (United States)

    Arustamov, D L; Mukhtarov, Sh T; Arustamov, L D

    2000-01-01

    Transurethral needle ablation (TUNA) of the prostate is an effective method of thermal treatment of patients with benign prostatic hyperplasia (BPH). Suprapubic transvesical access was used in order to extend indications for interstitial application of radiofrequency energy. Transvesical needle ablation (TVNA) was performed in 89 patients with BPH under conditions of chronic ischuria or in the presence of a suprapubic cystostoma. A cystoscope with an attachment for fixation and insertion of a needle electrode into prostatic tissue is inserted into the bladder through a newly created or adapted suprapubic access. The position of the needle is monitored by transurethral sonography. The ablation protocol is virtually the same as transurethral. Spontaneous urination normalized in 63 (70.8%) patients within 12 months. I-PSS, Qol, Qmax, RU, and PQmax improved. The prostate volume decreased by 1-.5%. TVNA is more effective than TUNA as a less invasive method which allows interventions under local anesthesia; there are virtually no contraindications to the use of TVNA and in many patients it can be performed in an outpatient setting.

  11. Pilot-scale radiofrequency blanching of potato cuboids: heating uniformity.

    Science.gov (United States)

    Zhang, Zhenna; Guo, Chaofan; Gao, Tong; Fu, Hongfei; Chen, Qin; Wang, Yunyang

    2018-01-01

    Traditional hot water blanching has a slow heat transfer rate, whereas radiofrequency (RF) heating has the advantages of a much faster heating rate and a higher penetration depth. In the present study, RF heating was applied to improve heating uniformity for subsequent blanching experiments involving potato cuboids. Potato cuboids were treated in a pilot-scale, RF heating system (27.12 MHz, 6 kW) under different operating conditions. The dielectric constant increased first and then decreased with temperature, whereas the loss factor increased as the temperature increased. The results of the present study reveal that the electrode gap, sample height and NaCl solution had significant effects (P uniformity of the sample after RF heating. The optimum RF heating uniformity was obtained at an electrode gap of 120 mm, a sample height of 60 mm and when immersed in NaCl solution of 0.5 s m-1 . The central heating pattern was presented in a sample. Cold spots were located at the edge of the top surface of the sample. The present study shows the great potential of RF heating for the blanching of vegetables. Future studies should aim to determine changes in the texture and nutrient contents of vegetables during RF heating. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. ALINE: A device dedicated to understanding radio-frequency sheaths

    Directory of Open Access Journals (Sweden)

    S. Devaux

    2017-08-01

    Full Text Available In fusion devices, radiofrequency (RF antennas are used for heating the plasma. Those antennas and the plasma interact with each other through the so-called RF sheaths, layers of plasma where the quasi-neutrality breaks down and large electric fields arise. Among the effects of RF sheaths, there is the enhancement of the particles and energy fluxes toward the surface of the antenna, which in turn generate hot spots and release impurities, which are both deleterious for plasma operations. RF sheaths comprehension stumbles on the difficulty to achieve in situ measurements of the sheath properties, as scrape-off layer plasmas are a harsh environment. The very goal of the ALINE device is to tackle this issue and to fulfil the blank between numerical simulations and full-scale experiment by providing measurements within the RF sheaths in a controlled environment. In this paper we report on the latest experimental results from ALINE, in which a cylindrical Langmuir probe mounted on a remotely controlled and programmable arm allows for plasma characterizations in the three dimensions of space around the stainless steel antenna, including the sheath. We present a series of density and potential profiles and three dimension (3D maps in the plasma surrounding a stainless-steel RF antenna as well as in the sheath itself, for unmagnetized and magnetized plasmas.

  13. Analysis and analytical characterization of bioheat transfer during radiofrequency ablation.

    Science.gov (United States)

    Wang, Keyong; Tavakkoli, Fatemeh; Wang, Shujuan; Vafai, Kambiz

    2015-04-13

    Understanding thermal transport and temperature distribution within biological organs is important for therapeutic aspects related to hyperthermia treatments such as radiofrequency ablation (RFA). Unlike surface heating, the RFA treatment volumetrically heats up the biological media using a heating probe which provides the input energy. In this situation, the shape of the affected region is annular, which is described by an axisymmetric geometry. To better understand the temperature responses of the living tissues subject to RFA, comprehensive characteristics of bioheat transport through the annular biological medium is presented under local thermal non-equilibrium (LTNE) condition. Following the operational features of the RFA treatment, based on the porous media theory, analytical solutions have been derived for the blood and tissue temperature distributions as well as an overall heat exchange correlation in cylindrical coordinates. Our analytical results have been validated against three limiting cases which exist in the literature. The effects of various physiological parameters, such as metabolic heat generation, volume fraction of the vascular space, ratio of the effective blood to tissue conductivities, different biological media and the rate of heat exchange between the lumen and the tissue are investigated. Solutions developed in this study are valuable for thermal therapy planning of RFA. A criterion is also established to link deep heating protocol to surface heating. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Wavelet Domain Radiofrequency Pulse Design Applied to Magnetic Resonance Imaging.

    Directory of Open Access Journals (Sweden)

    Andrew M Huettner

    Full Text Available A new method for designing radiofrequency (RF pulses with numerical optimization in the wavelet domain is presented. Numerical optimization may yield solutions that might otherwise have not been discovered with analytic techniques alone. Further, processing in the wavelet domain reduces the number of unknowns through compression properties inherent in wavelet transforms, providing a more tractable optimization problem. This algorithm is demonstrated with simultaneous multi-slice (SMS spin echo refocusing pulses because reduced peak RF power is necessary for SMS diffusion imaging with high acceleration factors. An iterative, nonlinear, constrained numerical minimization algorithm was developed to generate an optimized RF pulse waveform. Wavelet domain coefficients were modulated while iteratively running a Bloch equation simulator to generate the intermediate slice profile of the net magnetization. The algorithm minimizes the L2-norm of the slice profile with additional terms to penalize rejection band ripple and maximize the net transverse magnetization across each slice. Simulations and human brain imaging were used to demonstrate a new RF pulse design that yields an optimized slice profile and reduced peak energy deposition when applied to a multiband single-shot echo planar diffusion acquisition. This method may be used to optimize factors such as magnitude and phase spectral profiles and peak RF pulse power for multiband simultaneous multi-slice (SMS acquisitions. Wavelet-based RF pulse optimization provides a useful design method to achieve a pulse waveform with beneficial amplitude reduction while preserving appropriate magnetization response for magnetic resonance imaging.

  15. Water-cooled radiofrequency neuroablation for sacroiliac joint dysfunctional pain

    Directory of Open Access Journals (Sweden)

    Binay Kumar Biswas

    2016-01-01

    Full Text Available 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. Bilateral water cooled = RF was applied for neuroablation of nerves supplying both SI joints. Postprocedure pain intensity was 5/10 and after 7 days it was 2/10. On 18th-month follow-up, he is pain free except for mild pain (NRS 2/10 on occasional extreme twisting of the back. This case attempts to highlight that sacral neuroablation based on cooled RF technique can be a long lasting remedial option for chronic SI joint pain unresponsive to conventional treatment.

  16. Water-cooled radiofrequency neuroablation for sacroiliac joint dysfunctional pain

    Science.gov (United States)

    Biswas, Binay Kumar; Dey, Samarjit; Biswas, Saumya; Mohan, Varinder Kumar

    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. Bilateral water cooled = RF was applied for neuroablation of nerves supplying both SI joints. Postprocedure pain intensity was 5/10 and after 7 days it was 2/10. On 18th-month follow-up, he is pain free except for mild pain (NRS 2/10) on occasional extreme twisting of the back. This case attempts to highlight that sacral neuroablation based on cooled RF technique can be a long lasting remedial option for chronic SI joint pain unresponsive to conventional treatment. PMID:28096589

  17. 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.

  18. Measured radiofrequency exposure during various mobile-phone use scenarios.

    Science.gov (United States)

    Kelsh, Michael A; Shum, Mona; Sheppard, Asher R; McNeely, Mark; Kuster, Niels; Lau, Edmund; Weidling, Ryan; Fordyce, Tiffani; Kühn, Sven; Sulser, Christof

    2011-01-01

    Epidemiologic studies of mobile phone users have relied on self reporting or billing records to assess exposure. Herein, we report quantitative measurements of mobile-phone power output as a function of phone technology, environmental terrain, and handset design. Radiofrequency (RF) output data were collected using software-modified phones that recorded power control settings, coupled with a mobile system that recorded and analyzed RF fields measured in a phantom head placed in a vehicle. Data collected from three distinct routes (urban, suburban, and rural) were summarized as averages of peak levels and overall averages of RF power output, and were analyzed using analysis of variance methods. Technology was the strongest predictor of RF power output. The older analog technology produced the highest RF levels, whereas CDMA had the lowest, with GSM and TDMA showing similar intermediate levels. We observed generally higher RF power output in rural areas. There was good correlation between average power control settings in the software-modified phones and power measurements in the phantoms. Our findings suggest that phone technology, and to a lesser extent, degree of urbanization, are the two stronger influences on RF power output. Software-modified phones should be useful for improving epidemiologic exposure assessment.

  19. Hydrodynamic and kinetic modelling of complex radio-frequency plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Goedheer, W J; Venema, J [FOM Institute for Plasma Physics ' Rijnhuizen' , Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Land, V, E-mail: W.J.Goedheer@rijnhuizen.n [Center for Astrophysics, Space Physics and Engineering Research, Baylor University, Waco, TX 76798 (United States)

    2009-10-07

    In this paper hydrodynamic and kinetic approaches to model low-pressure capacitively coupled complex radio-frequency discharges are discussed and applied to discharges under micro-gravity. Complex plasmas contain dust grains with a large negative charge and are characterized by a strong coupling between the properties of the plasma and those of the dust grains. After a discussion of the physics and methods involved, examples are presented from modelling of experiments under micro-gravity in the PKE-Nefedov reactor on board the International Space Station. These discharges are simulated with a 2D cylindrically symmetric hydrodynamic model. Kinetic effects are studied with a 1D particle-in-cell plus Monte Carlo model in which capture and scattering by dust grains is included. Since experiments are often performed at low pressures, the electron energy distribution function is no longer determined by the local plasma properties. This has consequences for the charging of the dust. Results of simulations with this model are compared with the hydrodynamic results. In addition, we address the behaviour of the dust charge in decaying plasmas.

  20. Actual role of radiofrequency ablation of liver metastases

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Philippe L. [Eberhard-Karls-University of Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany)

    2007-08-15

    The liver is, second only to lymph nodes, the most common site for metastatic disease irrespective of the primary tumour. More than 50% of all patients with malignant diseases will develop liver metastases with a significant morbidity and mortality. Although the surgical resection leads to an improved survival in patients with colorectal metastases, only approximately 20% of patients are eligible for surgery. Thermal ablation and especially radiofrequency ablation emerge as an important additional therapy modality for the treatment of liver metastases. RF ablation shows a benefit in life expectancy and may lead in a selected patient group to cure. Percutaneous RF ablation appears safer (versus cryotherapy), easier (versus laser), and more effective (versus ethanol instillation and transarterial chemoembolisation) compared with other minimally invasive procedures. RF ablation can be performed by a percutaneous, laparoscopical or laparotomic approach, and may be potentially combined with chemotherapy and surgery. At present ideal candidates have tumours with a maximum diameter less than 3.5 cm. An untreatable primary tumour or a systemic disease represents contraindications for performing local therapies. Permanent technical improvements of thermal ablation devices and a better integration of thermal ablation in the overall patient care may lead to prognosis improvement in patients with liver metastases. (orig.)

  1. 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.

  2. Cryoballoon ablation versus radiofrequency ablation for atrial fibrillation.

    Science.gov (United States)

    Reissmann, Bruno; Metzner, Andreas; Kuck, Karl-Heinz

    2017-05-01

    Catheter ablation (CA) provides the most effective treatment option for patients suffering from symptomatic atrial fibrillation (AF). The procedural cornerstone of all ablation strategies and for all entities of AF is the electrical isolation of the pulmonary veins (PV). CA with the use of radiofrequency (RF) in conjunction with a 3-dimensional electroanatomical mapping system is the most established ablation approach, but it demands a long learning curve and recurrences of AF are commonly the result of recovered PV conduction. As a consequence, novel ablation systems such as the Cryoballoon (CB) have been evolved aiming at facilitation and increased efficacy of pulmonary vein isolation (PVI). CB ablation is characterized by a short learning curve as well as short procedure times and demonstrated non-inferiority with regard to safety and efficacy when being directly compared to RF ablation for treatment of paroxysmal AF. However, RF ablation is first choice for treatment of persistent AF, in particular when expanded ablation strategies beyond PVI are intended in order to improve clinical outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    Medeiros, Luisa Nascimento; Sanchez, Tanit Ganz

    2016-01-01

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

  4. Synthetic signal injection using a single radiofrequency channel.

    Science.gov (United States)

    Marro, Kenneth I; Lee, Donghoon; Shankland, Eric G; Mathis, Clinton M; Hayes, Cecil E

    2011-12-01

    To demonstrate that, when injecting an artificial reference signal for quantitation purposes, the real and artificial signals can be acquired separately, using a single radiofrequency (RF) channel, with no loss of fidelity. Conversion of MR signals to units of concentration can be simplified by injection of a precalibrated, artificial reference signal, or pseudo-signal. In previous implementations, the pseudo-signal was acquired simultaneously with the real signals arising from the sample and this requires a second, integrated RF channel. We used in vivo spectroscopy and in vitro imaging measurements to test the validity of the separate acquisition method. There was very strong correlation (r = 0.94; P = 0.02) between the in vivo concentrations determined with separate and simultaneous acquisition methods. The in vitro measurements validated that the separate acquisition method compensates for differences in coil loading conditions as well as the simultaneous acquisition method. Separate acquisition eliminates the need for a second RF channel, which allows easier implementation at sites that have only one channel available, and relaxes the constraints on the number and amplitude of pseudo-signals. This flexibility can be exploited to increase the signal to noise ratio of the pseudo-signal and reduce variability when making the conversion to units of concentration. Copyright © 2011 Wiley Periodicals, Inc.

  5. Radiofrequency Ablation Treatment for Renal Cell Carcinoma: Early Clinical Experience

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seong Hoon; Yoon, Seong Kuk; Cho, Jin Han; Oh, Jong Young; Nam, Kyung Jin; Kwon, Hee Jin; Kim, Su Yeon; Kang, Myong Jin; Choi, Sun Seob; Sung, Gyung Tak [Dong-A University College of Medicine, Busan (Korea, Republic of)

    2008-08-15

    To evaluate the early clinical experience associated with radiofrequency (RF) ablation in patients with renal cell carcinoma (RCC). The RF ablation treatment was performed on 17 tumors from 16 patients (mean age, 60.5 years; range, 43 73 years) with RCC. The treatment indications were localized, solid renal mass, comorbidities, high operation risk, and refusal to perform surgery. All tumors were treated by a percutaneous CT (n = 10), followed by an US-guided (n = 2), laparoscopy-assisted US (n = 2), and an open (n = 2) RF ablation. Furthermore, patients underwent a follow- up CT at one day, one week, one month, three and six months, and then every six months from the onset of treatment. We evaluated the technical success, technical effectiveness, ablation zone, benign periablation enhancement, irregular peripheral enhancement, and complications. All 17 exophytic tumors (mean size, 2.2 cm; range, 1.1 5.0 cm) were completely ablated. Technical success and effectiveness was achieved in all cases and the mean follow-up period was 23.8 months (range, 17 33 months). A local recurrence was not detected in any of the cases; however, five patients developed complications as a result of treatment, including hematuria (n = 2), mild thermal injury of the psoas muscle (n = 1), mild hydronephrosis (n = 1), and fistula formation (n = 1). The RF ablation is an alternative treatment for exophytic RCCs and represents a promising treatment for some patients with small RCCs.

  6. MR Detection of Mechanical Vibrations Using a Radiofrequency Field Gradient

    Science.gov (United States)

    Baril, Nathalie; Lewa, Czeslaw Jozef; de Certaines, Jacques Donald; Canioni, Paul; Franconi, Jean-Michel; Thiaudière, Eric

    2002-01-01

    A new method for NMR characterization of mechanical waves, based upon radiofrequency field gradient for motion encoding, is proposed. A binomial B1 gradient excitation scheme was used to visualize the mobile spins undergoing a periodic transverse mechanical excitation. A simple model was designed to simulate the NMR signal as a function of the wave frequency excitation and the periodicity of the NMR pulse sequence. The preliminary results were obtained on a gel phantom at low vibration frequencies (0-200 Hz) by using a ladder-shaped coil generating a nearly constant RF field gradient along a specific known direction. For very small displacements and/or B1 gradients, the NMR signal measured on a gel phantom was proportional to the vibration amplitude and the pulse sequence was shown to be selective with respect to the vibration frequency. A good estimation of the direction of vibrations was obtained by varying the angle between the motion direction and the B1 gradient. The method and its use in parallel to more conventional MR elastography techniques are discussed. The presented approach might be of interest for noninvasive investigation of elastic properties of soft tissues and other materials.

  7. Incidence and Cause of Hypertension During Adrenal Radiofrequency Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Yamakado, Koichiro, E-mail: yama@clin.medic.mie-u.ac.jp; Takaki, Haruyuki [Mie University School of Medicine, Department of Interventional Radiology (Japan); Yamada, Tomomi [Mie University School of Medicine, Department of Translational Medicine (Japan); Yamanaka, Takashi; Uraki, Junji; Kashima, Masataka; Nakatsuka, Atsuhiro; Takeda, Kan [Mie University School of Medicine, Department of Interventional Radiology (Japan)

    2012-12-15

    Purpose: To evaluate the incidence and cause of hypertension prospectively during adrenal radiofrequency ablation (RFA). Methods: For this study, approved by our institutional review board, written informed consent was obtained from all patients. Patients who received RFA for adrenal tumors (adrenal ablation) and other abdominal tumors (nonadrenal ablation) were included in this prospective study. Blood pressure was monitored during RFA. Serum adrenal hormone levels including epinephrine, norepinephrine, dopamine, and cortisol levels were measured before and during RFA. The respective incidences of procedural hypertension (systolic blood pressure >200 mmHg) of the two patient groups were compared. Factors correlating with procedural systolic blood pressure were evaluated by regression analysis.ResultsNine patients underwent adrenal RFA and another 9 patients liver (n = 5) and renal (n = 4) RFA. Asymptomatic procedural hypertension that returned to the baseline by injecting calcium blocker was found in 7 (38.9%) of 18 patients. The incidence of procedural hypertension was significantly higher in the adrenal ablation group (66.7%, 6/9) than in the nonadrenal ablation group (11.1%, 1/9, P < 0.0498). Procedural systolic blood pressure was significantly correlated with serum epinephrine (R{sup 2} = 0.68, P < 0.0001) and norepinephrine (R{sup 2} = 0.72, P < 0.0001) levels during RFA. The other adrenal hormones did not show correlation with procedural systolic blood pressure. Conclusion: Hypertension occurs frequently during adrenal RFA because of the release of catecholamine.

  8. Radiofrequency pulse design in parallel transmission under strict temperature constraints.

    Science.gov (United States)

    Boulant, Nicolas; Massire, Aurélien; Amadon, Alexis; Vignaud, Alexandre

    2014-09-01

    To gain radiofrequency (RF) pulse performance by directly addressing the temperature constraints, as opposed to the specific absorption rate (SAR) constraints, in parallel transmission at ultra-high field. The magnitude least-squares RF pulse design problem under hard SAR constraints was solved repeatedly by using the virtual observation points and an active-set algorithm. The SAR constraints were updated at each iteration based on the result of a thermal simulation. The numerical study was performed for an SAR-demanding and simplified time of flight sequence using B1 and ΔB0 maps obtained in vivo on a human brain at 7T. The proposed adjustment of the SAR constraints combined with an active-set algorithm provided higher flexibility in RF pulse design within a reasonable time. The modifications of those constraints acted directly upon the thermal response as desired. Although further confidence in the thermal models is needed, this study shows that RF pulse design under strict temperature constraints is within reach, allowing better RF pulse performance and faster acquisitions at ultra-high fields at the cost of higher sequence complexity. Copyright © 2013 Wiley Periodicals, Inc.

  9. Surgical and Pathological Changes after Radiofrequency Ablation of Thyroid Nodules

    Directory of Open Access Journals (Sweden)

    Chiara Dobrinja

    2015-01-01

    Full Text Available 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 to undergo a total thyroidectomy. Here we present how RFA has affected the operation and the final pathological features of the surgically removed nodules. Results and Conclusions. RFA is effective for the treatment of Thy2 nodules, but it should not be recommended as first-line therapy for the treatment of Thy3 nodules (irrespective of their mutational status, as it delays surgery in case of malignancy. Moreover, it is unknown whether RFA might promote residual tumor progression or neoplastic progression of Thy3 lesions. Nevertheless, here we show for the first time that one session of RFA does not affect subsequent thyroid surgery and/or histological diagnosis.

  10. Development of A Pulse Radio-Frequency Plasma Jet

    Science.gov (United States)

    Wang, Shou-Guo; Zhao, Ling-Li; Yang, Jing-Hua

    2013-09-01

    A small pulse plasma jet was driven by new developed radio-frequency (RF) power supply of 6.78 MHz. In contrast to the conventional RF 13.56 MHz atmospheric pressure plasma jet (APPJ), the power supply was highly simplified by eliminating the matching unit of the RF power supply and using a new circuit, moreover, a pulse controller was added to the circuit to produce the pulse discharge. The plasma jet was operated in a capacitively coupled manner and exhibited low power requirement of 5 W at atmospheric pressure using argon as a carrier gas. The pulse plasma plume temperature remained at less than 45 °C for an extended period of operation without using water to cool the electrodes. Optical emission spectrum measured at a wide range of 200-1000 nm indicated various excited species which were helpful in applying the plasma jet for surface sterilization to human skin or other sensitive materials. Institude of Plasma Physics, Chinese Academy of Science, Hefei, China.

  11. Aplicación de la técnica PIXE (Particle Induced X-Ray Emision a la caracterización no destructiva de una pieza de ajuar funerario (siglo I d.c. procedente de una excavación arqueológica (antiguo Hospital de las Cinco Llagas, Sevilla

    Directory of Open Access Journals (Sweden)

    Enrique Magariño, M. E.

    2002-12-01

    Full Text Available In this work, a non-destructive characterization of a burial-sample object dated S.I. a.C. (ring with an incrusted material coming from an archaeological excavation (former Hospital de las Cinco Llagas, Sevilla has been carried out. The glass or ceramic nature of this sample was unknown. Several non-destructive techniques have been applied: optical microscopy, SEM-EDX, XRD and XRF. In this particular case, the technique Particle Induced X-ray Emision (PIXE has been also applied. PIXE allows to obtain a fast information concerning chemical composition of trace elements using the object directly. The study of this interesting object indicates the extreme quality and accurance of the engrave observed on its surface, for instance a long-legged bird and a palm leaf despite their reduced size. Relief effects have been observed in the engrave using the own constitution of this particular material. The XRD phase analysis demonstrates that crystalline quartz as single phase constitutes the incrusted material of the ring considered as a gem: blue quartz. The chemical composition obtained from XRF analysis confirm the XRD result, with Si and O as main elements, although there are minoritary elements such as Ca and Fe (< 1,5 %, Na and Al (ca. 0,3 %. Other elements, such as Cl, K and P were detected in similar percentages (0.2-0,25 %, besides Mg and S (less than 0,08 %. However, the application of the PIXE technique based on ion beam analysis to this material allowed to demonstrate the presence of Ti and V, probably as ions in the quartz crystal structure which constitutes the gem. This experimental fact would then explain the blue colour observed in the gem. Consequently, PIXE as a non-destructive technique allows to find an important chemical difference between zones of the same object. There are some advantages, first of all that these chemical differences can not be accurately observed using other conventional techniques and secondly, the analysis is

  12. É possível diminuir o sangramento em hepatectomias sem a realização de exclusão vascular total ou parcial?: Resultados do uso de radiofrequência bipolar com agulhas resfriadas Is it possible to reduce the bleeding in hepatic resections without conducting total or partial vascular exclusion?: Results of the use of bipolar radiofrequency with cold needles

    Directory of Open Access Journals (Sweden)

    José Artur Sampaio

    2011-06-01

    Full Text Available RACIONAL: Embora a ressecção seja ainda o procedimento de escolha no tratamento curativo das lesões malignas do fígado, o sangramento permanece como fator de morbidade com grande impacto na cirurgia hepática. Com o intuito de minimizar esta complicação, diversas opções tecnológicas têm sido utilizadas, entre elas mais recentemente a radiofrequência, permitindo que o procedimento seja realizado com incisões menores, sem necessidade de clampeamento vascular, com mínima dissecção hepática, ou sangramento. OBJETIVO: Apresentar os resultados em uma série de pacientes utilizando nova técnica de ressecção do parênquima hepático através de agulhas paralelas de radiofrequência bipolar desenvolvidas pelos próprios autores, verificando o impacto no sangramento trans-operatório dos pacientes submetidos à hepatectomias. MÉTODOS: Sessenta pacientes foram submetidos à ressecção hepática através do uso da radiofrequência bipolar. O sangramento per-operatório foi avaliado através da medição do volume coletado em aspirador e pela diferença de peso nas compressas utilizadas durante o procedimento. Todos os casos foram acompanhados em sua função hepatocitária através de exames laboratoriais durante a primeira semana de pós-operatório. RESULTADOS: As ressecções hepáticas foram realizadas com média de 87 minutos, tamanho médio da incisão abdominal de 14 cm e sangramento médio de 58 mililitros. Nenhum paciente recebeu transfusão de sangue ou derivados. Não foram utilizados cateteres venosos centrais. Todos pacientes obtiveram rápida recuperação anestésica, obtendo alta da sala de recuperação para a enfermaria em menos de 12 horas. A drenagem pós-operatória foi anotada até a retirada do dreno abdominal em todos os pacientes. O tempo de internação hospitalar médio foi de 3,2 dias. Após um pico de elevação das provas de função hepática nos primeiros três dias, todos apresentaram retorno destes

  13. Radiofrequência na dor crônica Radiofrecuencia en el dolor crónico Radiofrequency in chronic pain

    Directory of Open Access Journals (Sweden)

    José Luciano Braun Filho

    2009-06-01

    Full Text Available Radiofrequência (RF é uma técnica minimamente invasiva alvo-seletiva e tem sido usada durante muitos anos para o tratamento de diferentes doenças, como dor lombar crônica, neuralgia trigeminal e outros. Trata-se de uma corrente elétrica alternada com frequência oscilatória de 500.000 hz, que flui através de um eletrodo introduzido percutaneamente. O calor é formado ao redor do eletrodo porque o tecido age como um resistor. Essa técnica pode, portanto, ser usada para causar lesões em tecidos nervosos no tratamento de dor crônica. O objetivo desta revisão é abordar alguns aspectos importantes do mecanismo e evolução da radiofrequência na dor crônica. Serão abordados os aspectos básicos da Física e o mecanismo de ação da radiofrequência, método que tem sido usado para tratar dores crônicas de diferentes etiologias, além da evolução com o advento da radiofrequência pulsátil. O uso da radiofrequência no manejo da dor crônica é uma ferramenta útil em diferentes condições dolorosas e tem sido usada com sucesso por mais de 25 anos. Seu mecanismo de ação ainda não foi totalmente elucidado. A radiofrequência pulsátil é, em particular, uma técnica minimamente destrutiva e poderá ser uma alternativa à forma convencional de tratamento para a dor por radiofrequência.Radiofrecuencia (RF es una técnica mínimamente invasiva con blanco selectivo, y ha sido usada durante muchos años para el tratamiento de diferentes patologías como dolor lumbar crónico, neuralgia trigeminal entre otros. Radiofrecuencia es una corriente eléctrica alternada con frecuencia oscilatoria de 500.000 hz. La corriente fluye por medio de un electrodo introducido percutáneamente y el calor es formado alrededor del electrodo, porque el tejido actúa como una resistencia. Por lo tanto, la radiofrecuencia puede ser usada para causar lesiones en tejidos nerviosos para tratamiento de dolor crónico. El objetivo de esta revisión es abordar

  14. Parálisis cerebral Cerebral palsy

    OpenAIRE

    Jorge Malagon Valdez

    2007-01-01

    El término parálisis cerebral (PC) engloba a un gran número de síndromes neurológicos clínicos, de etiología diversa. Estos síndromes se caracterizan por tener una sintomatología común: los trastornos motores. Algunos autores prefieren manejar términos como "encefalopatía fija", "encefalopatías no evolutivas". Se mencionan la utilidad de programas de intervención temprana y métodos especiales de rehabilitación, así como el manejo de las deficiencias asociadas como la epilepsia, deficiencia me...

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

    Science.gov (United States)

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

    2015-01-12

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

  16. Effects of radiation from a radiofrequency identification (RFID) microchip on human cancer cells.

    Science.gov (United States)

    Lai, Henry C; Chan, Ho Wing; Singh, Narendra P

    2016-01-01

    Radiofrequency identification (RFID) microchips are used to remotely identify objects, e.g. an animal in which a chip is implanted. A passive RFID microchip absorbs energy from an external source and emits a radiofrequency identification signal which is then decoded by a detector. In the present study, we investigated the effect of the radiofrequency energy emitted by a RFID microchip on human cancer cells. Molt-4 leukemia, BT474 breast cancer, and HepG2 hepatic cancer cells were exposed in vitro to RFID microchip-emitted radiofrequency field for 1 h. Cells were counted before and after exposure. Effects of pretreatment with the spin-trap compound N-tert-butyl-alpha-phenylnitrone or the iron-chelator deferoxamine were also investigated. Results We found that the energy effectively killed/retarded the growth of the three different types of cancer cells, and the effect was blocked by the spin-trap compound or the iron-chelator, whereas an inactive microchip and energy from the external source had no significant effect on the cells. Conclusions Data of the present study suggest that radiofrequency field from the microchip affects cancer cells via the Fenton Reaction. Implantation of RFID microchips in tumors may provide a new method for cancer treatment.

  17. Surgical Radiofrequency MAZE III Ablation for Treatment of Atrial Fibrillation During Open Heart Surgery

    Directory of Open Access Journals (Sweden)

    Fariborz Akbarzadeh

    2006-05-01

    Full Text Available Background: Atrial fibrillation is a common arrhythmia in patients with rheumatic mitral and other valve diseases who are candidates for valve repair surgeries. Conversion of rhythm to sinus has positive effects on quality of life and lower use of medications. The aim of this clinical study was to evaluate the effectiveness of the radiofrequency ablation Maze III procedure in the treatment of atrial fibrillation associated with rheumatic heart valve disease. Methods: We applied a modified Cox III Maze procedure using radiofrequency ablation in the treatment of atrial fibrillation associated with rheumatic heart valve disease and evaluated the outcome of 20 patients of atrial fibrillation associated rheumatic valve disease who underwent radiofrequency ablation Maze III procedure plus heart valve surgery. Demographic, echocardiographic, Electrocardiographic and Doppler study data were calculated before surgery, six month and one year after surgery.. Results: No perioperative deaths occurred in the study group. Duration of additional time for doing radiofrequency ablation was about 22 minutes. Freedom from atrial fibrillation was 85% and 75% at six months and one year follow-up respectively... Conclusions: The addition of the radiofrequency ablation Maze procedure to heart valve surgery is safe and effective in the treatment of atrial fibrillation associated with rheumatic heart valve disease.

  18. Evaluation of the current radiofrequency ablation systems using axiomatic design theory.

    Science.gov (United States)

    Zhang, Bing; Moser, Michael A J; Luo, Yigang; Zhang, Edwin M; Zhang, Wenjun

    2014-04-01

    This article evaluates current radiofrequency ablation systems using axiomatic design theory. Due to its minimally invasive procedure, short-time hospital stay, low cost, and tumour metastasis treatment, the radiofrequency ablation technique has been playing an important role in tumour treatment in recent decades. Although the radiofrequency ablation technique has many advantages, some issues still need to be addressed. Among these issues, the two most important are as follows: (1) the size of tumours to be removed (has to be larger than 3 cm in diameter) and (2) cleanness of the removal. Many device solutions have been proposed to address the two issues. However, there is a lack of knowledge regarding the systematic evaluation of these solutions. This article evaluates these systems in terms of their solution principles (or simply called conceptual design in general product design theory) using a design theory called axiomatic design theory. In addition, with the axiomatic design theory, a better conceptual design in terms of its feasibility to cope with incomplete target tissue necrosis from the large size of tumours has been found. The detailed analysis and simulation of the new conceptual design are conducted using finite element approach. The results in this article are proved by the information of animal experiments and clinical practices obtained from the literature. This study thus contributes to the current knowledge to further developments in radiofrequency ablation systems and procedure guidelines for physicians to perform the radiofrequency ablation operation more effectively.

  19. Noninvasive assessment of tissue heating during cardiac radiofrequency ablation using MRI thermography.

    Science.gov (United States)

    Kolandaivelu, Aravindan; Zviman, Menekhem M; Castro, Valeria; Lardo, Albert C; Berger, Ronald D; Halperin, Henry R

    2010-10-01

    Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences.

  20. Percutaneous radiofrequency treatment of osteoid osteoma using cool-tip electrodes

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-15

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

  1. Noninvasive Assessment of Tissue Heating During Cardiac Radiofrequency Ablation Using MRI Thermography

    Science.gov (United States)

    Kolandaivelu, Aravindan; Zviman, Menekhem M.; Castro, Valeria; Lardo, Albert C.; Berger, Ronald D.; Halperin, Henry R.

    2010-01-01

    Background Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. Methods and Results An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. Conclusions MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences. PMID:20657028

  2. TMS suppression of right pars triangularis, but not pars opercularis, improves naming in aphasia

    Science.gov (United States)

    Naeser, Margaret A.; Martin, Paula I.; Theoret, Hugo; Kobayashi, Masahito; Fregni, Felipe; Nicholas, Marjorie; Tormos, Jose M.; Steven, Megan S.; Baker, Errol H.; Pascual-Leone, Alvaro

    2011-01-01

    This study sought to discover if an optimum 1 cm2 area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1 Hz rTMS was applied to suppress different RH ROIs in eight aphasia cases. Picture naming and response time (RT) were examined before, and immediately after rTMS. In aphasia patients, suppression of right pars triangularis (PTr) led to significant increase in pictures named, and significant decrease in RT. Suppression of right pars opercularis (POp), however, led to significant increase in RT, but no change in number of pictures named. Eight normals named all pictures correctly; similar to aphasia patients, RT significantly decreased following rTMS to suppress right PTr, versus right POp. Differential effects following suppression of right PTr versus right POp suggest different functional roles for these regions. PMID:21864891

  3. Transcriptome profiling reveals links between ParS/ParR, MexEF-OprN, and quorum sensing in the regulation of adaptation and virulence in Pseudomonas aeruginosa.

    Science.gov (United States)

    Wang, Dongping; Seeve, Candace; Pierson, Leland S; Pierson, Elizabeth A

    2013-09-13

    The ParS/ParR two component regulatory system plays critical roles for multidrug resistance in Pseudomonas aeruginosa. It was demonstrated that in the presence of antimicrobials, ParR enhances bacterial survival by distinct mechanisms including activation of the mexXY efflux genes, enhancement of lipopolysaccharide modification through the arn operon, and reduction of the expression of oprD porin. In this study, we report on transcriptomic analyses of P. aeruginosa PAO1 wild type and parS and parR mutants growing in a defined minimal medium. Our transcriptomic analysis provides the first estimates of transcript abundance for the 5570 coding genes in P. aeruginosa PAO1. Comparative transcriptomics of P. aeruginosa PAO1 and par mutants identified a total of 464 genes regulated by ParS and ParR. Results also showed that mutations in the parS/parR system abolished expression of the mexEF-oprN operon by down-regulating the regulatory gene mexS. In addition to the known effects on drug resistance genes, transcript abundances of the quorum sensing genes (rhlIR and pqsABCDE-phnAB) were higher in both parS and parR mutants. In accordance with these results, a significant portion of the ParS/ParR regulated genes belonged to the MexEF-OprN and quorum sensing regulons. Deletion of the par genes also led to increased phenazine production and swarming motility, consistent with the up-regulation of the phenazine and rhamnolipid biosynthetic genes, respectively. Our results link the ParS/ParR two component signal transduction system to MexEF-OprN and quorum sensing systems in P. aeruginosa. These results expand our understanding of the roles of the ParS/ParR system in the regulation of gene expression in P. aeruginosa, especially in the absence of antimicrobials.

  4. Movement and equipositioning of plasmids by ParA filament disassembly

    DEFF Research Database (Denmark)

    Ringgaard, Simon; van Zon, Jeroen; Howard, Martin

    2009-01-01

    Bacterial plasmids encode partitioning (par) loci that confer stable plasmid inheritance. We showed previously that, in the presence of ParB and parC encoded by the par2 locus of plasmid pB171, ParA formed cytoskeletal-like structures that dynamically relocated over the nucleoid. Simultaneously, ...... of the plasmids. Mathematical modeling of ParA and plasmid dynamics support these interpretations. Mutational analysis supports a molecular mechanism in which the ParB/parC complex controls ParA filament depolymerization....

  5. Pratique du bloc infraclaviculaire par voie sous coracoïdienne par ...

    African Journals Online (AJOL)

    Toutefois, des efforts pour réduire le temps de réalisation, choisir la meilleure réponse motrice distale sur laquelle injecter l'anesthésique local, par une pratique plus fréquente des techniques d'ALR périphérique, sont nécessaires pour augmenter le confort des patients et le taux de succès du bloc. Mots clés: Anesthésie ...

  6. Combined pars plana vitrectomy and pars plana Baerveldt tube placement in eyes with neovascular glaucoma.

    Science.gov (United States)

    Kolomeyer, Anton M; Seery, Christopher W; Emami-Naeimi, Parisa; Zarbin, Marco A; Fechtner, Robert D; Bhagat, Neelakshi

    2015-01-01

    To describe characteristics and outcomes of combined pars plana vitrectomy and Baerveldt tube insertion procedure from 2005 to 2010 in eyes with neovascular glaucoma. Seventy-nine patients (89 eyes) with ≥2 months of follow-up were included. Outcome measures were visual acuity, intraocular pressure (IOP), number of glaucoma medications, and complications. Changes in mean logMAR visual acuity, IOP, and glaucoma medications were compared by a two-tailed t-test. Mean patient age was 69.0 years. Forty-three (54%) were male. Mean follow-up time was 19.9 months. Most common causes of neovascular glaucoma was diabetes (n = 63 [71%]) and central retinal vein occlusion (n = 21 [24%]). Eighty-six eyes (97%) underwent a 250 mm Baerveldt drainage device and 3 (3.4%) a 350 mm Baerveldt. Forty-five (51%) 20-gauge, 12 (13%) 23-gauge, and 32 (36%) 25-gauge pars plana vitrectomies were performed. Fifty-two eyes (58%) preoperatively and 23 (33%) postoperatively received intraocular injections for rubeosis and macular edema. Mean ± standard deviation logMAR visual acuity at 18-, 24-, 36-, and 48-month follow-up time points was significantly better than preoperative vision (P pars plana vitrectomy eyes. Nine eyes (10%) required return to the operating room after combined procedure, including 4 eyes (4.5%) for retinal detachment and 3 (3.4%) for high IOP due to tube occlusion. Three eyes (3.4%) developed endophthalmitis and 2 (2.2%) progressed to being pre/phthisical (none were enucleated). Combined pars plana vitrectomy and Baerveldt glaucoma shunt may be a useful procedure in reducing IOP and number of glaucoma medications in eyes with neovascular glaucoma along with stabilizing visual acuity in a majority of these eyes. Further studies are warranted to verify and expand on these findings.

  7. Doxycycline directly targets PAR1 to suppress tumor progression.

    Science.gov (United States)

    Zhong, Weilong; Chen, Shuang; Zhang, Qiang; Xiao, Ting; Qin, Yuan; Gu, Ju; Sun, Bo; Liu, Yanrong; Jing, Xiangyan; Hu, Xuejiao; Zhang, Peng; Zhou, Honggang; Sun, Tao; Yang, Cheng

    2017-03-07

    Doxycycline have been reported to exert anti-cancer activity and have been assessed as anti-cancer agents in clinical trials. However, the direct targets of doxycycline in cancer cells remain unclear. In this study, we used a chemical proteomics approach to identify the Protease-activated receptor 1 (PAR1) as a specific target of inhibition of doxycycline. Binding assays and single-molecule imaging assays were performed to confirm the inhibition of doxycycline to PAR1. The effect of doxycycline on multi-omics and cell functions were assessed based on a PAR1/thrombin model. Molecular docking and molecular dynamic simulations revealed that doxycycline interacts with key amino acids in PAR1. Mutation of PAR1 further confirmed the computation-based results. Moreover, doxycycline provides highly selective inhibition of PAR1 signaling in tumors in vitro and in vivo. Using pathological clinical samples co-stained for doxycycline and PAR1, it was found that doxycycline fluorescence intensity and PAR1 expression shown a clear positive correlation. Thus, doxycycline may be a useful targeted anti-cancer drug that should be further investigated in clinical trials.

  8. Priapisme induit par la chlorpromazine: A propos de deux cas

    African Journals Online (AJOL)

    I. Marrag

    Nous rapportons ici le cas de deux patients qui ont présenté un priapisme en concomitance avec une pres- cription de chlorpromazine .... ischémiques pourraient être induits par des médicaments dont les neuroleptiques occupent ... vie sexuelle des patients, souvent touchée par la prescription des traitements psychotropes ...

  9. Bacterial mitosis: partitioning protein ParA oscillates in spiral-shaped structures and positions plasmids at mid-cell

    DEFF Research Database (Denmark)

    Ebersbach, Gitte; Gerdes, Kenn; Charbon, Gitte Ebersbach

    2004-01-01

    The par2 locus of Escherichia coli plasmid pB171 encodes oscillating ATPase ParA, DNA binding protein ParB and two cis-acting DNA regions to which ParB binds (parC1 and parC2). Three independent techniques were used to investigate the subcellular localization of plasmids carrying par2. In cells w...

  10. ParABS system in chromosome partitioning in the bacterium Myxococcus xanthus.

    Directory of Open Access Journals (Sweden)

    Antonio A Iniesta

    Full Text Available Chromosome segregation is an essential cellular function in eukaryotic and prokaryotic cells. The ParABS system is a fundamental player for a mitosis-like process in chromosome partitioning in many bacterial species. This work shows that the social bacterium Myxococcus xanthus also uses the ParABS system for chromosome segregation. Its large prokaryotic genome of 9.1 Mb contains 22 parS sequences near the origin of replication, and it is shown here that M. xanthus ParB binds preferentially to a consensus parS sequence in vitro. ParB and ParA are essential for cell viability in M. xanthus as in Caulobacter crescentus, but unlike in many other bacteria. Absence of ParB results in anucleate cells, chromosome segregation defects and loss of viability. Analysis of ParA subcellular localization shows that it clusters at the poles in all cells, and in some, in the DNA-free cell division plane between two chromosomal DNA masses. This ParA localization pattern depends on ParB but not on FtsZ. ParB inhibits the nonspecific interaction of ParA with DNA, and ParA colocalizes with chromosomal DNA only when ParB is depleted. The subcellular localization of ParB suggests a single ParB-parS complex localized at the edge of the nucleoid, next to a polar ParA cluster, with a second ParB-parS complex migrating after the replication of parS takes place to the opposite nucleoid edge, next to the other polar ParA cluster.

  11. Radiofrequency Coblation Versus Intramural Bipolar Cautery for the Treatment of Inferior Turbinate Hypertrophy.

    Science.gov (United States)

    Shah, Anil N; Brewster, Douglas; Mitzen, Kelly; Mullin, David

    2015-09-01

    Compare intramural bipolar electrocautery and radiofrequency coblation in the treatment of inferior turbinate hypertrophy with regards to objective and subjective improvement in nasal obstruction, rate and type of complications, experience during the procedure, and rate of recovery. Prospective, single-blinded study. Single tertiary medical center from 2008 to 2010. Forty-one adult patients with inferior turbinate hypertrophy refractory to medical management were treated with radiofrequency coblation in one nostril and intramural bipolar cautery in the other. Subjective and objective data, including use of a Visual Analog Scale (VAS) for subjective outcomes, acoustic rhinometry, and nasal endoscopy, were then obtained from each patient comparing the 2 techniques. Radiofrequency coblation was significantly less painful than intramural bipolar cautery during the procedure (P = .03) and during the early postoperative period (P hypertrophy with less discomfort during the procedure and early post-operative period. © The Author(s) 2015.

  12. Photonic radio-frequency dissemination via optical fiber with high-phase stability.

    Science.gov (United States)

    Wang, Xiaocheng; Liu, Zhangweiyi; Wang, Siwei; Sun, Dongning; Dong, Yi; Hu, Weisheng

    2015-06-01

    We demonstrate a photonic radio-frequency transmission system via optical fiber. Optical radio-frequency signal is generated utilizing a Mach-Zehnder modulator based on double-side-band with carrier suppression modulation scheme. The phase error induced by optical fiber transmission is transferred to an intermediate frequency signal by the dual-heterodyne phase error transfer scheme, and then canceled by a phase locked loop. With precise phase compensation, a radio frequency with high-phase stability can be obtained at the remote end. We performed 20.07-GHz radio-frequency transfer over 100-km optical fiber, and achieved residual phase noise of -65  dBc/Hz at 1-Hz offset frequency, and the RMS timing jitter in the frequency range from 0.01 Hz to 1 MHz reaches 110 fs. The long-term frequency stability also achieves 8×10(-17) at 10,000 s averaging time.

  13. Comparative study of four radiofrequency generators for the treatment of snoring.

    Science.gov (United States)

    Blumen, Marc B; Chalumeau, Frédéric; Gauthier, Anne; Bobin, Serge; Coste, André; Chabolle, Frédéric

    2008-03-01

    To compare the efficacy and safety of four radiofrequency generators (Ellman, Select Sutter, Coblator, Somnus) for the treatment of simple snoring. Multicenter, randomized, prospective single-blind study on 120 selected patients with simple snoring (apnea/hypopnea index <10/h of sleep). Snoring sound intensity was measured on a visual analog scale and the partner's short-term satisfaction rate was evaluated after two treatment sessions maximum. Discomfort, pain, and medication intake were compared. Radiofrequency decreased the snoring sound intensity from 7.9 +/- 1.7 to 4.4 +/- 2.7 (P < 0.0001). The four radiofrequency generators had a statistically comparable efficacy. The Ellman generator caused less discomfort and required less anti-inflammatory drugs. Despite different technical characteristics, the four generators had a comparable efficacy with good safety. The Ellman generator induced the least discomfort.

  14. Bilateral occipital lobe infarction with altitudinal field loss following radiofrequency cardiac catheter ablation

    Directory of Open Access Journals (Sweden)

    Chen Celia S

    2010-03-01

    Full Text Available Abstract Background Bilateral stroke following radiofrequency catheter ablation is an unusual complication and may result in bilateral altitudinal visual field defects. Bilateral altitudinal visual field defects usually result from prechiasmal pathology causing damage to both retinas or optic nerves and rarely from bilateral symmetric damage to the post chiasmal visual pathways. Case presentation A 48-year-old man complained of visual disturbance on wakening following radiofrequency catheter ablation. The patient had a CHADS score of 1 pre-operatively and no complications were noted intra-operatively. Examination revealed a bilateral superior altitudinal defect and MRI of the brain showed multifocal areas of infarction predominantly involving the occipital lobes which correlated to with the visual deficits. Conclusion While the risk of thromboembolism and perioperative stroke during radiofrequency catheter ablation is small, it is not insignificant.

  15. Non-invasive radiofrequency ablation of malignancies mediated by quantum dots, gold nanoparticles and carbon nanotubes.

    Science.gov (United States)

    Glazer, Evan S; Curley, Steven A

    2011-10-01

    Various types of nanoparticles efficiently heat in radiofrequency fields, which can potentially be used to produce cancer cell cytotoxicity within minutes. Multifunctional and targeted nanoparticles have demonstrated effective cancer control in vivo without significant toxicity associated with radiofrequency field exposure. Importantly, animals treated systemically with targeted nanoparticles smaller than 50 nm demonstrate tumor necrosis after radiofrequency field exposure without acute or chronic toxicity to normal tissues. Likewise, the future holds great promise for multifunctional imaging as well as multimodality therapy with chemotherapeutic molecules and ionizing radiation sensitizing agents attached to nanoparticle constructs. However, the appropriate balance of safety and efficacy for diagnosis, therapy, and therapeutic monitoring with these nanoparticles remains to be fully elucidated.

  16. A randomized study between excision and marsupialization and radiofrequency sinus excision in sacro-coccygeal pilonidal disease.

    Science.gov (United States)

    Gupta, Pravin J

    2004-01-01

    The surgical approach to pilonidal sinus disease is open to debate. This prospective, randomized study was aimed to compare the outcome of the excision and marsupialization and the sinus excision technique by radiofrequency. Thirty patients of chronic pilonidal sinus disease were randomly assigned to radiofrequency sinus excision (n = 15) and excision and marsupialization (n = 15). The parameters measured included intraoperative and postoperative data, wound-related complications, and recurrence. Patient satisfaction score was assessed at 1-year follow-up. The operation time, postoperative pain, hospital stay, and off work periods were significantly less (p < 0.05) in the technique employing radiofrequency surgery. At 1-year follow-up, there was 1 case of recurrence in each group. The patients from radiofrequency group expressed better satisfaction than the patients operated by marsupialization. Radiofrequency sinus excision technique needs a shorter hospital stay with reduced postoperative pain and early resumption to work in comparison with the sinus excision and marsupialization technique.

  17. Postoperative metabolic acidosis following the minimally invasive radiofrequency maze procedure

    Directory of Open Access Journals (Sweden)

    Raymond Patrick Hom

    2016-01-01

    Full Text Available Purpose: Atrial fibrillation (AF is the most common arrhythmia treated in the world. While medical treatment with antiarrhythmic drugs remains the primary treatment modality, symptomatic refractory AF often requires treatment with a catheter or surgical ablation. One minimally invasive therapy is the Mini-Maze procedure, which utilizes epicardial radiofrequency ablation via a subxiphoid approach to rid the heart of arrhythmogenic atrial foci without a median sternotomy or cardiopulmonary bypass. The goal of this retrospective cohort study was to identify clinical factors associated with metabolic acidosis following the Mini-Maze procedure. Materials and Methods: After Institutional Review Board approval, we studied patients undergoing the Mini-Maze procedure, off-pump coronary artery bypass grafting or patients conventional Cox-Maze on cardiopulmonary bypass. The first base deficit value obtained in the Intensive Care Unit was used as a measure of metabolic acidosis. Using logistic regression with Akaike information criteria, we analyzed preoperative, intraoperative, and postoperative data to determine the factors associated with changes in base deficit. Results: A multivariable model using stepwise selection demonstrated that diabetes mellitus and weight were associated with a decrease in the base deficit by 2.87 mEq/L (95% CI: −5.55-−0.19 and 0.04 mEq/L (95%CI: −0.08, 0.004, respectively. Furthermore, creatinine was associated with a 1.57 mEq/L (95% CI: 0.14, 2.99 increase in the base deficit. Conclusion: The Mini-Maze procedure was not associated with postoperative metabolic acidosis. Instead, nondiabetic patients and patients with higher creatinine were associated with greater base deficits after undergoing cardiac surgery.

  18. Postoperative metabolic acidosis following the minimally invasive radiofrequency maze procedure.

    Science.gov (United States)

    Hom, Raymond Patrick; Dubovoy, Anna; Jewell, Elizabeth; Engoren, Milo

    2016-01-01

    Atrial fibrillation (AF) is the most common arrhythmia treated in the world. While medical treatment with antiarrhythmic drugs remains the primary treatment modality, symptomatic refractory AF often requires treatment with a catheter or surgical ablation. One minimally invasive therapy is the Mini-Maze procedure, which utilizes epicardial radiofrequency ablation via a subxiphoid approach to rid the heart of arrhythmogenic atrial foci without a median sternotomy or cardiopulmonary bypass. The goal of this retrospective cohort study was to identify clinical factors associated with metabolic acidosis following the Mini-Maze procedure. After Institutional Review Board approval, we studied patients undergoing the Mini-Maze procedure, off-pump coronary artery bypass grafting or patients conventional Cox-Maze on cardiopulmonary bypass. The first base deficit value obtained in the Intensive Care Unit was used as a measure of metabolic acidosis. Using logistic regression with Akaike information criteria, we analyzed preoperative, intraoperative, and postoperative data to determine the factors associated with changes in base deficit. A multivariable model using stepwise selection demonstrated that diabetes mellitus and weight were associated with a decrease in the base deficit by 2.87 mEq/L (95% CI: -5.55--0.19) and 0.04 mEq/L (95%CI: -0.08, 0.004), respectively. Furthermore, creatinine was associated with a 1.57 mEq/L (95% CI: 0.14, 2.99) increase in the base deficit. The Mini-Maze procedure was not associated with postoperative metabolic acidosis. Instead, nondiabetic patients and patients with higher creatinine were associated with greater base deficits after undergoing cardiac surgery.

  19. Noninvasive radiofrequency ablation of cancer targeted by gold nanoparticles.

    Science.gov (United States)

    Cardinal, Jon; Klune, John Robert; Chory, Eamon; Jeyabalan, Geetha; Kanzius, John S; Nalesnik, Michael; Geller, David A

    2008-08-01

    Current radiofrequency ablation (RFA) techniques require invasive needle placement and are limited by accuracy of targeting. The purpose of this study was to test a novel non invasive radiowave machine that uses RF energy to thermally destroy tissue. Gold nanoparticles were designed and produced to facilitate tissue heating by the radiowaves. A solid state radiowave machine consisting of a power generator and transmitting/receiving couplers which transmit radiowaves at 13.56 MHz was used. Gold nanoparticles were produced by citrate reduction and exposed to the RF field either in solutions testing or after incubation with HepG2 cells. A rat hepatoma model using JM-1 cells and Fisher rats was employed using direct injection of nanoparticles into the tumor to focus the radiowaves for select heating. Temperatures were measured using a fiber-optic thermometer for real-time data. Solutions containing gold nanoparticles heated in a time- and power-dependent manner. HepG2 liver cancer cells cultured in the presence of gold nanoparticles achieved adequate heating to cause cell death upon exposure to the RF field with no cytotoxicity attributable to the gold nanoparticles themselves. In vivo rat exposures at 35 W using direct gold nanoparticle injections resulted in significant temperature increases and thermal injury at subcutaneous injection sites as compared to vehicle (water) injected controls. These data show that non invasive radiowave thermal ablation of cancer cells is feasible when facilitated by gold nanoparticles. Future studies will focus on tumor selective targeting of nanoparticles for in vivo tumor destruction.

  20. Nanoionics-Based Switches for Radio-Frequency Applications

    Science.gov (United States)

    Nessel, James; Lee, Richard

    2010-01-01

    Nanoionics-based devices have shown promise as alternatives to microelectromechanical systems (MEMS) and semiconductor diode devices for switching radio-frequency (RF) signals in diverse systems. Examples of systems that utilize RF switches include phase shifters for electronically steerable phased-array antennas, multiplexers, cellular telephones and other radio transceivers, and other portable electronic devices. Semiconductor diode switches can operate at low potentials (about 1 to 3 V) and high speeds (switching times of the order of nanoseconds) but are characterized by significant insertion loss, high DC power consumption, low isolation, and generation of third-order harmonics and intermodulation distortion (IMD). MEMS-based switches feature low insertion loss (of the order of 0.2 dB), low DC power consumption (picowatts), high isolation (>30 dB), and low IMD, but contain moving parts, are not highly reliable, and must be operated at high actuation potentials (20 to 60 V) generated and applied by use of complex circuitry. In addition, fabrication of MEMS is complex, involving many processing steps. Nanoionics-based switches offer the superior RF performance and low power consumption of MEMS switches, without need for the high potentials and complex circuitry necessary for operation of MEMS switches. At the same time, nanoionics-based switches offer the high switching speed of semiconductor devices. Also, like semiconductor devices, nanoionics-based switches can be fabricated relatively inexpensively by use of conventional integrated-circuit fabrication techniques. More over, nanoionics-based switches have simple planar structures that can easily be integrated into RF power-distribution circuits.

  1. Percutaneous Ultrasound-guided Radiofrequency Ablation of Intrahepatic Cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Yi-You Chiou

    2005-07-01

    Full Text Available This study evaluated the clinical applications, treatment effects, and complications of percutaneous ultrasound (US-guided radiofrequency ablation (RFA of intrahepatic cholangiocarcinoma. Ten patients (6 men and 4 women with histologically proven cholangiocarcinoma underwent US-guided percutaneous RFA. Tumor diameters ranged from 1.9 to 6.8 cm. There were 12 sessions of RFA for 10 solitary cholangiocarcinomas. Eight patients were treated at a single session and two patients had two treatment sessions. The efficacy of RFA was evaluated using contrast-enhanced dynamic computed tomography 1 month after treatment and then every 3 months. Complete necrosis was defined as lack of contrast enhancement of the treated region. There was complete necrosis in eight tumors. In two patients with large tumors (4.7 and 6.8 cm in diameter, enhancement of residual tissue was observed after RFA treatment, indicating residual tumor. Complete necrosis was seen in all five tumors (100% with diameters of 3.0 cm or less, two of three tumors (67% with diameters of 3.1-5.0 cm, and one of two tumors (50% with diameters of more than 5.0 cm. A large biloma was found in one patient after treatment. No serious complications occurred in the other nine patients. In conclusion, percutaneous RFA is effective and successful in the treatment of intrahepatic cholangiocarcinoma of 3 cm or less and satisfactory for tumors of 3-5 cm. The rate of serious complications after RFA is low. Further follow-up is necessary to determine long-term efficacy.

  2. The effects of radiofrequency electromagnetic radiation on sperm function.

    Science.gov (United States)

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

    2016-12-01

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

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

    Science.gov (United States)

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

    2017-06-15

    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. © The Author 2016. Published by Oxford University Press.

  4. Screen printed flexible radiofrequency identification tag for oxygen monitoring.

    Science.gov (United States)

    Martínez-Olmos, A; Fernández-Salmerón, J; Lopez-Ruiz, N; Rivadeneyra Torres, A; Capitan-Vallvey, L F; Palma, A J

    2013-11-19

    In this work, a radiofrequency identification (RFID) tag with an optical indicator for the measurement of gaseous oxygen is described. It consists of an O2 sensing membrane of PtOEP together with a full electronic system for RFID communication, all printed on a flexible substrate. The membrane is excited by an LED at 385 nm wavelength and the intensity of the luminescence generated is registered by means of a digital color detector. The output data corresponding to the red coordinate of the RGB color space is directly related to the concentration of O2, and it is sent to a microcontroller. The RFID tag is designed and implemented by screen printing on a flexible substrate for the wireless transmission of the measurement to a remote reader. It can operate in both active and passive mode, obtaining the power supply from the electromagnetic waves of the RFID reader or from a small battery, respectively. This system has been fully characterized and calibrated including temperature drifts, showing a high-resolution performance that allows measurement of very low values of oxygen content. Therefore this system is perfectly suitable for its use in modified atmosphere packaging where the oxygen concentration is reduced below 2%. As the reading of the O2 concentration inside the envelope is carried out with an external RFID reader using wireless communication, there is no need for perforations for probes or wires, so the packaging remains completely closed. With the presented device, a limit of detection of 40 ppm and a resolution as low as 0.1 ppm of O2 can be reached with a low power consumption of 3.55 mA.

  5. Percutaneous selective radiofrequency nerve ablation for glabellar frown lines.

    Science.gov (United States)

    Kim, Jun Hyung; Jeong, Jin Wook; Son, Daegu; Han, Kihwan; Lee, So Young; Choi, Tae Hyun; Chang, David W

    2011-09-01

    The dynamic muscles of the glabellar region can be overactive, giving patients a "scowling" look and making them appear angry, worried, or stressed. The authors describe percutaneous selective nerve ablation, a minimally-invasive procedure for treatment of glabellar frown lines, and report results from a series of patients treated with the technique. From November 2007 to December 2009, 27 patients (22 women and five men) underwent percutaneous selective nerve ablation to improve glabellar frown lines. Initially, the surface pathway of the nerve to the corrugator supercilii and procerus was checked with a peripheral nerve stimulator. For percutaneous localization, a 22-gauge monopolar electrode was introduced into the lateral brow and cheek skin without incision. Short electrical stimulation (0.3-0.5 mA) was delivered to identify the proper lesion sites. Synchronous contraction of corrugator supercilii was elicited and radiofrequency nerve ablation performed (85°C, 70 seconds). In all patients, the frontal branch of the facial nerve and angular nerve were treated bilaterally. The improvement was evaluated with the Wrinkle Assessment Scale. Mean patient age was 54.5 years, and mean follow-up time was 18 months (range, 12-26 months). One patient had superficial second-degree burns to the brow skin, which healed with conservative treatment. Two patients had temporary paresthesia that completely resolved in a few weeks without sequelae. The Wrinkle Assessment Scale indicated a statistically significant improvement in the glabellar frown lines (preoperative vs postoperative mean, 3.7 vs 1.8; P safety and efficacy of percutaneous selective nerve ablation.

  6. Bleeding after percutaneous radiofrequency ablation: Successful treatment with transcatheter embolization

    Energy Technology Data Exchange (ETDEWEB)

    Carrafiello, Gianpaolo [Vascular and Interventional Radiology, Department of Radiology, University of Insubria, 21100 Varese (Italy)]. E-mail: gcarraf@tin.it; Lagana, Domenico [Vascular and Interventional Radiology, Department of Radiology, University of Insubria, 21100 Varese (Italy)]. E-mail: donlaga@gmail.com; Ianniello, Andrea [Vascular and Interventional Radiology, Department of Radiology, University of Insubria, 21100 Varese (Italy)]. E-mail: ianand@libero.it; Craparo, Giuseppe [Vascular and Interventional Radiology, Department of Radiology, University of Insubria, 21100 Varese (Italy)]. E-mail: crapgiu@libero.it; Recaldini, Chiara [Vascular and Interventional Radiology, Department of Radiology, University of Insubria, 21100 Varese (Italy)]. E-mail: chiarec@libero.it; Lumia, Domenico [Vascular and Interventional Radiology, Department of Radiology, University of Insubria, 21100 Varese (Italy)]. E-mail: domenicolumia@gmail.com; Dionigi, Gianlorenzo [Department of General Surgery, University of Insubria, 21100 Varese (Italy)]. E-mail: gianlorenzodionigi@uninsubria.it; Cuffari, Salvatore [Service of Anaesthesiology, University of Insubria, 21100 Varese (Italy)]. E-mail: domi7@libero.it; Fugazzola, Carlo [Vascular and Interventional Radiology, Department of Radiology, University of Insubria, 21100 Varese (Italy)]. E-mail: radiovarese@libero.it

    2007-02-15

    Purpose: This knowledge will provide an ability to earlier detect bleeding complications after radiofrequency ablation (RFA), to manage these complications appropriately with endovascular procedures and minimize the sequelae. Materials and methods: From 2002 to 2005, 96 patients with 150 hepatic tumours underwent 126 RFA sessions. Fifty-eight patients had HCC, 34 had liver colorectal metastases and 4 had cholangiocellular carcinoma. Sixty-one patients were men and 35 were women (mean age 69.82 years, age range 39-89). The lesions number ranged from 1 to 7 per patients (mean 1.6 nodules) with a mean diameter of 28.5 mm (range 80-10 mm). Seventy-seven patients underwent a single ablative session, 13 patients underwent 2 sessions, 4 patients underwent 3 sessions and 2 patients underwent 4 sessions. The number of tumours treated in each ablative session was 1 in 106, 2 in 18 and 4 in 2 patients. Results: Two cases of serious haemorrhages occurred after the procedures in two patients treated for liver metastases. An endovascular embolization was proposed for both patients using polyvinyl-alcohol and micro-coils. The absence of bleeding was first confirmed during angiography and then by CT performed the day after the angiographic procedure. Conclusion: Transarterial embolization (TAE) represents the treatment of choice in the management of iatrogenic bleeding after RFA since it is minimally invasive, have a high success rate and a low incidence of complications compared to the more complex and dangerous surgical or laparoscopic options in patients who are often haemodynamically unstable and therefore at high anaesthetic and surgical risk.

  7. Anatomical Comparison of Radiofrequency Ablation Techniques for Sacroiliac Joint Pain.

    Science.gov (United States)

    Roberts, Shannon L; Stout, Alison; Loh, Eldon Y; Swain, Nathan; Dreyfuss, Paul; Agur, Anne M

    2018-02-05

    To compare the percentage of sacral lateral branches (LBs) that would be captured if lesions were created by seven current sacroiliac joint (SIJ) radiofrequency ablation (RFA) techniques: three monopolar and four bipolar. Cadaveric fluoroscopy study. Anatomy and surgical skills laboratories. Forty cadaveric SIJs. LBs were exposed, radiopaque wires were sutured to LBs, and anterior-posterior fluoroscopic images through the S1 superior endplate were obtained. Lesions that would be created by 17 versions of seven current SIJ RFA techniques were mapped on the fluoroscopic images. These 17 versions were compared: 1) percentage of LBs that would be captured; 2) percentage of SIJ specimens in which 100% of LBs would be captured; and 3) percentage of LBs that would not be captured at each level (S1-S4). Both the mean LB and 100% capture rates were greater for the bipolar techniques (93.4-99.7% and 62.5-97.5%, respectively) than for the monopolar techniques (49.6-99.1% and 2.5-92.5%, respectively) evaluated. For the bipolar techniques, 1.5-29.2% of LBs would not be captured at S1 and 0% at S2-S4 vs 0-29.2% at S1-S4 for the cooled monopolar techniques vs 36.9-100% at S1-S4 for the conventional monopolar technique. The findings suggest that, if lesions were created, the RFA needle placement locations of the bipolar techniques evaluated may be capable of capturing all LBs, but those of the current monopolar techniques evaluated may not. Future in vivo imaging studies are required to compare the lesion morphology generated by different SIJ RFA techniques and correlate the findings with clinical outcomes.

  8. Adaptive ultrasound temperature imaging for monitoring radiofrequency ablation.

    Directory of Open Access Journals (Sweden)

    Yi-Da Liu

    Full Text Available Radiofrequency ablation (RFA has been widely used as an alternative treatment modality for liver tumors. Monitoring the temperature distribution in the tissue during RFA is required to assess the thermal dosage. Ultrasound temperature imaging based on the detection of echo time shifts has received the most attention in the past decade. The coefficient k, connecting the temperature change and the echo time shift, is a medium-dependent parameter used to describe the confounding effects of changes in the speed of sound and thermal expansion as temperature increases. The current algorithm of temperature estimate based on echo time shift detection typically uses a constant k, resulting in estimation errors when ablation temperatures are higher than 50°C. This study proposes an adaptive-k algorithm that enables the automatic adjustment of the coefficient k during ultrasound temperature monitoring of RFA. To verify the proposed algorithm, RFA experiments on in vitro porcine liver samples (total n = 15 were performed using ablation powers of 10, 15, and 20 W. During RFA, a clinical ultrasound system equipped with a 7.5-MHz linear transducer was used to collect backscattered signals for ultrasound temperature imaging using the constant- and adaptive-k algorithms. Concurrently, an infrared imaging system and thermocouples were used to measure surface temperature distribution of the sample and internal ablation temperatures for comparisons with ultrasound estimates. Experimental results demonstrated that the proposed adaptive-k method improved the performance in visualizing the temperature distribution. In particular, the estimation errors were also reduced even when the temperature of the tissue is higher than 50°C. The proposed adaptive-k ultrasound temperature imaging strategy has potential to serve as a thermal dosage evaluation tool for monitoring high-temperature RFA.

  9. Efficacy of percutaneous radiofrequency ablation of osteoid osteoma in children

    Energy Technology Data Exchange (ETDEWEB)

    Donkol, Ragab H. [Cairo University, Department of Radiology, Faculty of Medicine, Cairo (Egypt); Assir Central Hospital, Department of Radiology, P.O. Box 34, Abha (Saudi Arabia); Al-Nammi, Ahmed [Assir Central Hospital, Department of Radiology, P.O. Box 34, Abha (Saudi Arabia); Moghazi, Khaled [Alexandria University, Faculty of Medicine, Alexandria (Egypt)

    2008-02-15

    Percutaneous radiofrequency (RF) ablation of osteoid osteoma has high technical and clinical success rates. However, there are limited data on its use in the treatment of osteoid osteoma in children. To assess the safety and efficacy of CT-guided percutaneous RF ablation of osteoid osteoma in children and compare the outcomes with published data on its use in patients unselected for age. From January 2003 to July 2006, 23 children with osteoid osteoma were treated with CT-guided RF ablation using a straight rigid electrode. Their mean age was 11 years (range 3.5-16 years) and there were 15 boys and 8 girls. The procedures were carried out under general anaesthesia. Follow-up was performed to assess technical and clinical outcome. The mean follow-up period was 2.5 years (range 13-49 months). Technical success was achieved in 21 children (91.3%). Failure occurred in two children, in one due to failure to adequately localize the nidus within the dense sclerosis and in the other because of a short ablation time (2 min) because he developed hyperthermia. Clinical success was achieved in 18 patients within 2-5 days (primary clinical success rate 78.2%).These patients were allowed to fully weight-bear and function without limitation 1 week after the procedure. Pain recurrence was observed in two patients; one was treated successfully with a second ablation after 6 months (secondary clinical success rate 82.6%). Hyperthermia was observed in two patients during the procedure. Three other minor complications were observed: wound infection in one child and skin burn in two children. No major immediate or delayed complications were observed. Percutaneous CT-guided RF ablation is an effective and safe minimally invasive procedure for the treatment of osteoid osteoma in children. It has high technical and clinical success rates that are slightly lower than those of patients with a wider range of ages. (orig.)

  10. Recombination in the human Pseudoautosomal region PAR1.

    Directory of Open Access Journals (Sweden)

    Anjali G Hinch

    2014-07-01

    Full Text Available The pseudoautosomal region (PAR is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome.

  11. INTRAOPERATIVE RADIOFREQUENCY AND CRYOABLATION FOR ATRIAL FIBRILLATION IN PATIENTS WITH VALVULAR HEART DISEASE

    Directory of Open Access Journals (Sweden)

    N. Maghamipour N. Safaie

    2007-05-01

    Full Text Available Patients with valvular heart disease and suffering atrial fibrillation of more than 12 months duration have a low probability of remaining in sinus rhythm after valve surgery alone. We performed intra-operative radiofrequency ablation or cryoablation as an alternative to surgical maze ІІІ procedure to create linear lesion lines for conversion of this arrhythmia to sinus rhythm. A total of 30 patients with valvular heart disease and chronic persistent atrial fibrillation underwent different combinations of valve surgery and concomitant maze procedure with radiofrequency or cryo probes. These patients aged 48.10 ± 9.84 years in radiofrequency ablation group and 51.10 ± 13.93 years in cryoablation group. Both atrial ablation with radiofrequency probes, needed 26.15 ± 3.67 min extra ischemic time and ablation by mean of cryo-probes needed an extra ischemic time of 29.62 ± 4.27 min. There was one in hospital death postoperatively because of respiratory failure but no other complication. 6 months after the operation, among 30 patients with both atrial ablations, 25 patients were in sinus rhythm, no patient had junctional rhythm and 5 patients had persistent atrial fibrillation. At 12 months follow up, freedom from atrial fibrillation was 85% in radiofrequency group and 80% in cryo group. Doppler echocardiography in these patients demonstrated atrial contractility in 70% of the patients. Intraoperative radiofrequency or cryo-ablation of both atriums are effective and less invasive alternatives for the original maze procedure to eliminate the atrial fibrillation, and can be done in patients with valvular heart disease without increasing the risk of operation.

  12. [Radiofrequency kyphoplasty - an innovative method for the treatment of vertebral compression fractures - comparison with conservative treatment].

    Science.gov (United States)

    Bornemann, R; Kabir, K; Otten, L A; Deml, M; Koch, E M W; Wirtz, D C; Pflugmacher, R

    2012-09-01

    An evaluation of treatment protocols was used to expand the documentation of efficacy and safety of radiofrequency kyphoplasty (RFK). Additionally, a comparison of this new and innovative procedure with conservative treatment was carried out. Patients with painful osteoporotic vertebral fractures according to the common findings in an orthopaedic university hospital were included in the comparison study in which the indication for surgical intervention action according to the DVO guidelines was interdisciplinary confirmed. For the comparison group, patients with the same clinical and radiological findings were recruited who rejected a surgical intervention. For surgery, the StabiliT® Vertebral Augmentation System for a radiofrequency kyphoplasty by the company DFine was used. The cement was injected with a "multiplex controller". Thus, the results of the new method were compared to those of a group that was treated conservatively. The radiofrequency kyphoplasty (n = 114) resulted in an average decrease of VAS scores by almost 60 mm, which increased during the follow-up. Similarly, the Oswestry scores showed a marked improvement by 46 % points after 6 weeks. The mean increase in vertebral body height was 2.8 mm after radiofrequency kyphoplasty. In the conservatively treated group only very small changes compared to the initial findings were registered during the 6-week observation period. Accordingly, 33 of 67 patients decided after 6 weeks for surgery, which led to corresponding improvements (VAS, Oswestry, vertebral body height). Noteworthy is the low rate of cement leakage in the radiofrequency kyphoplasty group of 6 % (n = 7). Radiofrequency kyphoplasty offers a secure superiority over conservative treatment regarding clinical efficacy. In addition, the fractured vertebrae can be better targeted and erected, a longer processing time of the cement is ensured, a high interdigitation of the cement with the bone is guaranteed, the rate of cement leakage is low, the

  13. Megestrol acetate NCD oral suspension--Par Pharmaceutical: megestrol acetate nanocrystal dispersion oral suspension, PAR 100.2, PAR-100.2.

    Science.gov (United States)

    2007-01-01

    Par Pharmaceutical has developed megestrol acetate (Megace ES) oral suspension for the treatment of anorexia, cachexia and a significant weight loss associated with AIDS. Par Pharmaceutical used Elan Corporation's NanoCrystal Dispersion (NCD) technology to develop an advanced, concentrated formulation of megestrol acetate with improved bioavailability, more rapid onset of action, more convenient dosing and a lower dosing regimen compared with the original marketed formulation of megestrol acetate oral suspension. Patients are administered a teaspoon (5mL) of the new NCD formulation once daily, compared with a daily 20mL dosage cup of the original formulation. The new megestrol acetate NCD formulation represents a line-extension of Par's megestrol acetate oral suspension (800mg/20mL, Megace O/S) that has been marketed for anorexia, cachexia and AIDS-related weight loss since July 2001. Par's megestrol acetate is the generic version of Bristol-Myers Squibb's Megace Oral Suspension. NanoCrystal Dispersion (NCD) is a trademark of Elan Corporation. Par Pharmaceutical will market megestol acetate NCD oral suspension under the Megace brand name. The company licensed the Megace name from Bristol-Myers Squib in August 2003. The US FDA approved megestrol acetate oral suspension (625 mg/mL) in July 2005 for the treatment of anorexia, cachexia or a significant, unexplained weight loss in patients with AIDS. The NDA for the product was accepted for review by the agency in September 2004, following its submission in June of that year.Par Pharmaceutical commenced the first of two phase III clinical trials of megestrol acetate oral suspension (PAR 100.2) in cancer-induced anorexia in the first quarter of 2006. However, this trial was discontinued in September 2006 because of slow patient enrolment. The company intends to discuss future development options in this indication with the FDA.New formulations or dosage forms of megestrol acetate concentrated suspension are also in

  14. Effects of thrombin, PAR-1 activating peptide and a PAR-1 antagonist on umbilical artery resistance in vitro

    Directory of Open Access Journals (Sweden)

    Elliott John T

    2005-02-01

    Full Text Available Abstract Background The non-thrombotic effects of thrombin in cardiovascular tissues, as mediated via the protease activated receptors (PARs, and particularly PAR-1, have been the focus of much recent research. The aims of this study were to evaluate the effects of thrombin, a specific PAR-1 activating peptide (PAR1-AP, and a PAR-1 antagonist on human umbilical artery tone in vitro. Methods Human umbilical artery samples were obtained from 17 women at term. Arterial rings were suspended under physiologic conditions for isometric recording. The in vitro effects of thrombin (0.5 units/mL to 3 units/mL, PAR1-AP TFLLR-NH2 [10(-9 to 10(-6 M], and PAR-1 antagonist (N-trans cinnamoyl- p-fluoroPhe-p-guanidinoPhe-Leu-Arg-Orn-NH2 [10(-9 M to 10(-5 M] on umbilical artery tone were measured. Results Both thrombin and TFLLR-NH2 exerted a potent cumulative vasodilatory effect on human umbilical artery resistance (P 0.05. Conclusion These findings highlight a potential role for thrombin and PAR-1 receptors in vascular regulation of feto-placental blood flow in normal pregnancy, and in association with the vascular lesions associated with IUGR and pre-eclampsia.

  15. IGF-II receptors in luminal and basolateral membranes isolated from pars convoluta and pars recta of rabbit proximal tubule

    DEFF Research Database (Denmark)

    Jacobsen, Christian; Jessen, H; Flyvbjerg, A

    1995-01-01

    The binding of 125I-labeled insulin-like growth factor-II (125I-IGF-II) to luminal and basolateral membrane vesicles isolated from pars convoluta and the straight part (pars recta) of rabbit proximal tubule was investigated. Analyses of the binding data by use of the general stoichiometric bindin...

  16. Thermistor guided radiofrequency ablation of atrial insertion sites in patients with accessory pathways.

    Science.gov (United States)

    Tracy, C M; Moore, H J; Solomon, A J; Rodak, D J; Fletcher, R D

    1995-11-01

    Radiofrequency ablation has gained acceptance in the treatment of patients with symptomatic Wolff-Parkinson-White syndrome. The purpose of this study was to characterize the relation between temperature and other electroconductive parameters in patients undergoing atrial insertion accessory pathway ablation utilizing a thermistor equipped catheter. The mean temperature and power at sites of atrial insertion ablation are lower than has been previously associated with creation of radiofrequency lesions in the ventricle. While high cavitary blood flow in the atrium may result in cooling, the thinner atrial tissue may require less energy to achieve adequate heating than ventricular myocardium.

  17. Transthoracic percutaneous radiofrequency ablation for liver tumors in the hepatic dome.

    Science.gov (United States)

    Shibata, Toyomichi; Shibata, Toshiya; Maetani, Yoji; Kubo, Takeshi; Itoh, Kyo; Togashi, Kaori; Hiraoka, Masahiro

    2004-11-01

    Computed tomography (CT)-guided transthoracic radiofrequency ablation was performed for nine liver tumors of eight patients, which were located in the hepatic dome and undetectable by ultrasound (US). A total 11 sessions of ablation were performed. Complications were noted in five sessions (45%) and no complications were noted in six sessions (55%). Pneumothorax was noted in five sessions (45%), including two sessions (18%) with major pneumothorax requiring a chest tube. Major complications were seen in two sessions (18%), major pneumothorax and both major pneumothorax and moderate pleural effusion, respectively. CT-guided transthoracic radiofrequency ablation may be an alternative for treatments of liver tumor in the hepatic dome.

  18. [A new method of radiofrequency needle ablation of the prostate in the treatment of benign hyperplasia].

    Science.gov (United States)

    Mukhtarov, Sh T; Arustamov, D L

    2002-01-01

    The authors present the results of a new transvesical approach for radiofrequency needle ablation of the prostate in 29 patients with benign prostatic hyperplasia (BPH). The ablation has been done using a new radiofrequency generator ESHFG-440-40-1 made in Russia. Upon 12-month follow-up urination normalized in 23 patients. This result is better than that after transurethral needle ablation. The transvesical needle ablation has no contradictions and can be used in a wide range of patients with BPH both in hospital and outpatient settings.

  19. Experimental and clinical studies with radiofrequency-induced thermal endometrial ablation for functional menorrhagia

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, J.H.; Lewis, B.V.; Prior, M.V.; Roberts, T. (Watford General Hospital, Herts (England))

    1990-11-01

    A method of ablating the endometrium has been introduced into clinical practice that uses radiofrequency electromagnetic energy to heat the endometrium, using a probe inserted through the cervix. Preliminary studies suggest that over 80% of patients treated will develop either amenorrhea or a significant reduction in flow. The advantages of radiofrequency endometrial ablation over laser ablation or resection are the avoidance of intravascular fluid absorption, simplicity (no special operative hysteroscopic skills are required), speed of operation, and reduced cost compared with the Nd:YAG laser. In this paper, we describe the experimental studies performed during development of this new technique.

  20. Lumbar Sympathetic Pulsed Radiofrequency Treatment for Primary Erythromelalgia: A Case Report.

    Science.gov (United States)

    Lee, Jin Young; Sim, Woo Seog; Kang, Ryung A; Lee, Eun Kyung; Yang, Jae Young; Kim, Dae Yoon

    2017-01-01

    Erythromelalgia is often refractory and resistant to many forms of treatment. Numerous therapeutic options have been tried, but effective treatment remains elusive. The sympathetic nervous system has been involved in various painful conditions of neuropathic, vascular, and visceral origin. Sympathetic block is helpful in making a diagnosis and managing pain. We report a case of excellent pain relief after lumbar sympathetic pulsed radiofrequency treatment in a patient with primary erythromelalgia of the lower extremities. This case suggests the viability of pulsed radiofrequency treatment in patients with erythromelalgia. © 2016 Wiley Periodicals, Inc.

  1. Par j 1 and Par j 2, the major allergens from Parietaria judaica pollen, have similar immunoglobulin E epitopes.

    Science.gov (United States)

    Asturias, J A; Gómez-Bayón, N; Eseverri, J L; Martínez, A

    2003-04-01

    Parietaria judaica is the main cause of allergy in Mediterranean countries. The major allergens from P. judaica pollen, Par j 1 and Par j 2, have amino acid sequence identity of 45% and contain eight cysteine residues involved in disulphide bonds that compact the structure. The aim of the study was to identify IgE-binding epitopes on Par j 1 and Par j 2, the major allergens from P. judaica pollen and correlate them with the three-dimensional structure of the proteins. Overlapping peptides representing the complete length of Par j 1 and Par j 2 were synthesized on a cellulose-derivatized membrane. Sera from 17 P. judaica-allergenic patients were used to identify IgE-binding epitopes. Homology modelling of the three dimensional structure of both allergens was generated using the Swiss-Model software on the basis of previously reported crystal structures. Five and eight IgE-binding epitopes were identified on Par j 1 and Par j 2 allergens, respectively. Both proteins belonged to the non-specific lipid transfer proteins (ns-LTP) family and therefore a three-dimensional model of both allergens was constructed on the basis of the maize ns-LTP crystal structure. Par j 1 and Par j 2 allergens have three similar allergenic epitopes with high homology and identical conformation. Three similar IgE-epitopes of major allergens from P. judaica have been described. They could be good candidates for designing of IgE haptens as therapeutic agents with reduced anaphylactic side-effects or for developing hypoallergenic variants of these major allergens.

  2. Scleral Buckling for Rhegmatogenous Retinal Detachment Associated with Pars Planitis.

    Science.gov (United States)

    Kim, Yong-Kyu; Yoon, Wontae; Ahn, Jae Kyoun; Park, Sung Pyo

    2016-01-01

    Purpose. To evaluate the surgical outcome of scleral buckling (SB) in rhegmatogenous retinal detachment (RRD) patients associated with pars planitis. Methods. Retrospective review of RRD patients (32 eyes of pars planitis RRD and 180 eyes of primary RRD) who underwent SB. We compared primary and final anatomical success rates and visual outcomes between two groups. Results. Primary and final anatomical success were achieved in 25 (78.1%) and 31 (96.8%) eyes in the pars planitis RRD group and in 167 eyes (92.7%) and 176 eyes (97.7%) in primary RRD group, respectively. Both groups showed significant visual improvement (p Pars planitis RRD group was associated with higher rate of postoperative proliferative vitreoretinopathy (PVR) development (12.5% versus 2.8%, p = 0.031). Pars planitis and high myopia were significant preoperative risk factors and pseudophakia was borderline risk for primary anatomical failure after adjusting for various clinical factors. Conclusions. Pars planitis associated RRD showed inferior primary anatomical outcome after SB due to postoperative PVR development. However, final anatomical and visual outcomes were favorable. RRD cases associated with pars planitis, high myopia, and pseudophakia might benefit from different surgical approaches, such as combined vitrectomy and SB.

  3. Scleral Buckling for Rhegmatogenous Retinal Detachment Associated with Pars Planitis

    Directory of Open Access Journals (Sweden)

    Yong-Kyu Kim

    2016-01-01

    Full Text Available Purpose. To evaluate the surgical outcome of scleral buckling (SB in rhegmatogenous retinal detachment (RRD patients associated with pars planitis. Methods. Retrospective review of RRD patients (32 eyes of pars planitis RRD and 180 eyes of primary RRD who underwent SB. We compared primary and final anatomical success rates and visual outcomes between two groups. Results. Primary and final anatomical success were achieved in 25 (78.1% and 31 (96.8% eyes in the pars planitis RRD group and in 167 eyes (92.7% and 176 eyes (97.7% in primary RRD group, respectively. Both groups showed significant visual improvement (p<0.001 and there were no significant differences in final visual acuity. Pars planitis RRD group was associated with higher rate of postoperative proliferative vitreoretinopathy (PVR development (12.5% versus 2.8%, p=0.031. Pars planitis and high myopia were significant preoperative risk factors and pseudophakia was borderline risk for primary anatomical failure after adjusting for various clinical factors. Conclusions. Pars planitis associated RRD showed inferior primary anatomical outcome after SB due to postoperative PVR development. However, final anatomical and visual outcomes were favorable. RRD cases associated with pars planitis, high myopia, and pseudophakia might benefit from different surgical approaches, such as combined vitrectomy and SB.

  4. Multi-scale photoacoustic remote sensing (PARS) (Conference Presentation)

    Science.gov (United States)

    Haji Reza, Parsin; Bell, Kevan; Shi, W.; Zemp, Roger J.

    2016-03-01

    We introduce a novel multi-scale photoacoustic remote sensing (PARS) imaging system. Our system can provide optical resolution details for superficial structures as well as acoustic resolution for deep-tissue imaging down to 5 cm, in a non-contact setting. PARS system does not require any contact with the sample or ultrasound coupling medium. The optical resolution PARS (OR-OARS) system uses optically focused pulsed excitation with optical detection of photoacoustic signatures using a long-coherence interrogation beam co-focused and co-scanned with the excitation spot. In the OR-PARS initial pressures are sampled right at their subsurface origin where acoustic pressures are largest. The Acoustic resolution PARS (AR-PARS) picks up the surface oscillation of the tissue caused by generated photoacoustic signal using a modified version of Michelson interferometry. By taking advantage of 4-meters polarization maintaining single-mode fiber and a green fiber laser we have generated a multi-wavelength source using stimulated Raman scattering. Remote functional imaging using this multi-wavelength excitation source and PARS detection mechanism has been demonstrated. The oxygen saturation estimations are shown for both phantom and in vivo studies. Images of blood vessel structures for an In vivo chicken embryo model is demonstrated. The Phantom studies indicates ~3µm and ~300µm lateral resolution for OR-PARS and AR-PARS respectively. To the best of our knowledge this is the first dual modality non-contact optical and acoustic resolution system used for in vivo imaging.

  5. Quantitation of the major allergen of several Parietaria pollens by an anti-Par 1 monoclonal antibody-based ELISA. Analysis of crossreactivity among purified Par j 1, Par o 1 and Par m 1 allergens.

    Science.gov (United States)

    Ayuso, R; Carreira, J; Polo, F

    1995-10-01

    Plants of the genus Parietaria, Urticaceae family, represent a major cause of pollinosis in the Mediterranean area. Different Parietaria species crossreact to a great extent, but studies on the crossreactivity among the major allergens of these pollens have not been carried out so far. To develop an immunochemical method to quantify the major Parietaria judaica allergen, Par j 1, as well as to verify the presence of Par j 1-like proteins in different Urticaceae pollens. These proteins would be purified in order to study the cross-reactivity among them. Immunoaffinity chromatography with a monoclonal antibody, solid-phase enzyme-linked immunoassays and SDS-PAGE. A monoclonal antibody-based ELISA for the quantification of Par j 1 has been developed. The assay has a sensitivity of 0.2 ng/mL and shows a high correlation with the allergenic activity of P. judaica extracts determined by radioallergosorbent assay (RAST) inhibition. By means of this assay, proteins homologous to Par j 1 were detected in P. officinalis and P. mauritanica. These proteins (Par o 1 and Par m 1, respectively) were purified by affinity chromatography using the same monoclonal antibody employed in the ELISA. Crossed-inhibition experiments demonstrated that Par j 1, Par o 1, and Par m 1, competed for the binding of specific IgE from a P. judaica-sensitive patients serum pool. The results here described suggest that shared allergenic epitopes are present in the three main allergens investigated, which may simplify the diagnosis and therapy for Parietaria allergy.

  6. uPAR as anti-cancer target

    DEFF Research Database (Denmark)

    Lund, Ida K; Illemann, Martin; Thurison, Tine

    2011-01-01

    , and a potential diagnostic and predictive impact of the different uPAR forms has been reported. Hence, pericellular proteolysis seems to be a suitable target for anti-cancer therapy and numerous approaches have been pursued. Targeting of this process may be achieved by preventing the binding of uPA to u...... using mouse monoclonal antibodies (mAbs) against mouse uPA or uPAR. These reagents will target uPA and uPAR in both stromal cells and cancer cells, and their therapeutic potential can now be assessed in syngenic mouse cancer models....

  7. The inflammatory marker suPAR after cardiac arrest

    DEFF Research Database (Denmark)

    Rundgren, Malin; Lyngbaek, Stig; Fisker, Helle

    2015-01-01

    BACKGROUND: Soluble urokinase plasminogen activator receptor (suPAR) is released in response to inflammatory stimuli, and plasma levels are associated with long-term outcomes. The ischemia/reperfusion injury caused by cardiac arrest (CA) and resuscitation triggers an inflammatory response...... analysis shoved an AUC of 0.76 at 6 hours. In the subgroup of CA of cardiac cause, the AUC was 0.84. CONCLUSION: suPAR levels at 6 and 36 hours after CA were significantly higher in nonsurviving patients compared with survivors; however, the overlap in suPAR levels between the outcome groups...

  8. Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation.

    Science.gov (United States)

    Perry, Daniel; Morris, Alan; Burgon, Nathan; McGann, Christopher; Macleod, Robert; Cates, Joshua

    2012-02-23

    Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts.

  9. [Transoral radiofrequency coblation surgery for the treatment of hypopharyngeal carcinoma].

    Science.gov (United States)

    Xiao, S F; Li, W Y; Zhang, J B; Wang, J; Jia, J X; Yang, D H; Zhao, X; Huo, H; Shen, H

    2017-05-07

    Objective: To explore the feasibility and effectiveness of transoral surgery (TOS) for the treatment of hypopharyngeal carcinoma by means of the radiofrequency coblation(RFC). Methods: Twenty-two patients with hypopharyngeal carcinoma who were treated with TOS using RFC during the years of 2010-2016 were enrolled. Among these patients, 15 suffered from pyriform sinus carcinoma, 4 suffered from postcricoid carcinoma, and 3 suffered from posterior hypopharyngeal wall carcinoma. According to the AJCC 2002 guideline, the tumor stages were T1N0M0 for 3 patients, T2N0M0 for 9 patients, T1N1M0 for 1 patient, T1N2M0 for 1 patient, T2N1M0 for 4 patients, and T2N2M0 for 4 patients respectively. All patients with N+ underwent concurrent neck dissection; 2 patients underwent concurrent prophylactic tracheotomy; 17 underwent post-operative radiotherapy for 50-66 Gy. The follow-up time was 6-72 months with a median 35 months.Two patients were lost to follow-up. Results: All patients except 2 underwent the TOS successfully, while the two patients were treated with open approach surgery due to unsure safe margin. Most patients returned to oral feeding within one week. Among the 18 patients with complete follow up data, 3 had the local recurrence of the tumor (16.7%) and one died due to local recurrence, multiple primary esophageal carcinoma, and distant metastasis 4 years after surgery (5.6%). According to the Kaplan-Meier method, the 5-years local control rate and survival rate were 57.8% and 67.5% respectively. All patients had no disorders in speech, swallowing and respiration during the follow up. Conclusions: The RFC can be applied in TOS for the treatments of hypopharyngeal carcinoma with high cutting efficiency and better control of intraoperative hemorrhage, which is useful in lowering the operation difficulty. The oncologic results are comparable to the open surgery with satisfactory postoperative organ function preservation.

  10. POTENTIAL OF ULTRASOUND-GUIDED LUMBAR FACET RADIOFREQUENCY DENERVATION

    Directory of Open Access Journals (Sweden)

    I. V. Volkov

    2017-01-01

    Full Text Available The aim of the study was to evaluate the possibility of US navigation for Radiofrequency denervation (RFD of the lumbar facets.Material and methods. The authors performed a prospective controlled cohort study which included 50 patients with chronic pain syndrome who underwent RFD LIII-SI facets on both sides. The main group (US included 25 patients, who underwent US guided navigation with FScontrol of the correct placement of the cannula prior to ablation. In the control group (FS the RFD was performed only under FS control. Patients were selected after preliminary test block of medial branch with 50% pain reduction from the baseline. Patients with overweight, spinal deformity, pronounced degenerative changes, spinal stenosis and developmental anomalies were not included in the study. For the evaluation of outcomes, the numeric pain scale NRS-11 and the Oswestry index (ODI were used, the accuracy of the cannula position was assessed and factors determining the accuracy were searched.Results. As a result of the intervention, there was a significant decrease of NRS-11 and ODI criteria in both groups (p<0.001, a positive outcome was achieved in 18 (72% of US patients and 16 (64% of FS patients, p = 0.564. Of the 200 attempts to position the cannula under the ultrasound control, 169 (84.5% were successful, in most cases (187 out of 200, 93.5% at least 3 attempts were required to reposition the cannula. The average time for performing the procedure under the ultrasound control was 47.3±1.13 minutes. The facet angle and procedure level were defined as predictors of the cannula positioning accuracy, odds ratio 0.93 (95% CI 0.894–0.963 and 0.51 (95% CI 0.32–0.805, respectively.Conclusion. RFD of lumbar facet under ultrasound navigation allows to achieve a relatively high accuracy of the cannula position into the zone of passage of the articular branch. The navigation capabilities are reduced at the level of LV and SI vertebrae due to structural

  11. Unipolar radiofrequency treatment to improve the appearance of cellulite.

    Science.gov (United States)

    Alexiades-Armenakas, Macrene; Dover, Jeffrey S; Arndt, Kenneth A

    2008-09-01

    Previous studies suggest that radiofrequency (RF) energy may be effective as a treatment for cellulite. This bilateral paired blinded comparative study assesses the efficacy and safety of a unipolar RF device for improving the appearance of cellulite using a new quantitative cellulite grading system. In this randomized, blinded, split-design study, 10 individuals (aged 32-57 years) with a clinically observable excess of subcutaneous fat and cellulite (minimum grade 2 out of 4) on the thighs received up to six unilateral treatments (number of treatments at the investigator's discretion) at 2-week intervals with unipolar RF. The untreated side of the thigh served as an internal control. Treated thighs were randomly assigned by alternate allocation. Results were evaluated using study participant questionnaires and by two blinded evaluators (JSD, KAA) using photographs and the author's (MAA) cellulite grading scale at each treatment visit and at 1-month and 3-month follow-up visits after the final treatment. A novel quantitative four-point cellulite grading system is presented and applied, which separately grades dimple density, dimple distribution, dimple depth, diameter and contour. All participants responded to treatment (mean of 4.22 and range of three to six treatments). The blinded evaluations of photographs using the cellulite grading scale demonstrated the following mean grading scores for the treated leg versus the control leg: dimple density of 2.73 vs 3.18 (11.25% mean improvement), dimple distribution 2.89 vs 3.32 (10.75% mean improvement), dimple depth 1.47 vs 1.54 (2.5% mean improvement), and mean score of 2.36 (SEM 0.45) vs 2.68 (SEM 0.57) (8.00+/-2.84% mean improvement). The treatment was painless and side effects included minimal to moderate erythema which resolved within 1 to 3 hours. No crusting, scarring or dyspigmentation was observed. This randomized, blinded, split-design, controlled study employing a quantitative four-point grading scale

  12. Radiofrequency ablation of liver metastases; Radiofrequenzablation von Lebermetastasen

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, P.L.; Clasen, S.; Schmidt, D.; Wiskirchen, J.; Tepe, G.; Claussen, C.D. [Abt. fuer Radiologische Diagnostik, Eberhard-Karls-Univ. Tuebingen (Germany); Boss, A. [Abt. fuer Radiologische Diagnostik, Eberhard-Karls-Univ. Tuebingen (Germany); Sektion fuer Experimentelle Radiologie der Abt. fuer Radiologische Diagnostik, Eberhard-Karls-Univ. Tuebingen (Germany); Gouttefangeas, C. [Abt. Immunologie des Inst. fuer Zellbiologie, Eberhard-Karls-Univ. Tuebingen (Germany); Burkart, C. [Zentrum fuer gastroenterologische Onkologie der Medizinischen Klinik, Eberhard-Karls-Univ. Tuebingen (Germany)

    2004-04-01

    The liver is the second only to lymph nodes as the most common site of metastatic disease irrespective of the primary tumor. Up to 50% of all patients with malignant diseases will develop liver metastases with a significant morbidity and mortality. Although the surgical resection leads to an improvement of the survival time, only approximately 20% of the patients are eligible for surgical intervention. Radiofrequency (RF) ablation represents one of the most important alternatives as well as complementary methods for the therapy of liver metastases. RF ablation can lead in a selected patient group to a palliation or to an increased life expectancy. RF ablation appears either safer (vs. cryotherapy) or easier (vs. laser) or more effective (percutaneous ethanol instillation [PEI]), transarterial chemoembolisation [TACE] in comparison with other minimal invasive procedures. RF ablation can be performed percutaneously, laparoscopically or intraoperatively and may be combined with chemotherapy as well as with surgical resection. Permanent technical improvements of RF systems, a better understanding of the underlying electrophysiological principles and an interdisciplinary approach will lead to a prognosis improvement in patients with liver metastases. (orig.) [German] Die Leber ist unabhaengig vom Primaertumor nach den Lymphknoten die zweithaeufigste Lokalisation von Metastasen. Bis zu 50% aller Patienten mit malignen Erkrankungen werden im Verlauf ihrer Erkrankung Lebermetastasen entwickeln, die mit einer signifikanten Morbiditaet und Mortalitaet verbunden sind. Obwohl die chirurgische Resektion zu einer verlaengerten Ueberlebenszeit fuehrt, sind nur ca. 20% der Patienten fuer einen chirurgischen Eingriff geeignet. Die Radiofrequenz-(RF-)Ablation stellt derzeit eine der effektivsten Alternativen und komplementaeren Methoden bei der Therapie von Lebermetastasen dar. In einem selektierten Patientengut fuehrt die RF-Ablation ueber den palliativen Einsatz hinaus zu einer

  13. Par j 1 and Par j 2, the two major allergens in Parietaria judaica, bind preferentially to monoacylated negative lipids.

    Science.gov (United States)

    González-Rioja, Roberto; Asturias, Juan A; Martínez, Alberto; Goñi, Félix M; Viguera, Ana Rosa

    2009-03-01

    Par j 1 and Par j 2 proteins are the two major allergens in Parietaria judaica pollen, one of the main causes of allergic diseases in the Mediterranean area. Each of them contains eight cysteine residues organized in a pattern identical to that found in plant nonspecific lipid transfer proteins. The 139- and 102-residue recombinant allergens, corresponding respectively to Par j 1 and Par j 2, refold properly to fully functional forms, whose immunological properties resemble those of the molecules purified from the natural source. Molecular modeling shows that, despite the lack of extensive primary structure homology with nonspecific lipid transfer proteins, both allergens contain a hydrophobic cavity suited to accommodate a lipid ligand. In the present study, we present novel evidence for the formation of complexes of these natural and recombinant proteins from Parietaria pollen with lipidic molecules. The dissociation constant of oleyl-lyso-phosphatidylcholine is 9.1 +/- 1.2 microm for recombinant Par j 1, whereas pyrenedodecanoic acid shows a much higher affinity, with a dissociation constant of approximately 1 microm for both recombinant proteins, as well as for the natural mixture. Lipid binding does not alter the secondary structure content of the protein but is very efficient in protecting disulfide bonds from reduction by dithiothreitol. We show that Par j 1 and Par j 2 not only bind lipids from micellar dispersions, but also are able to extract and transfer negative phospholipids from bilayers.

  14. Influence of x-rays on the radiofrequency dielectric properties of ...

    African Journals Online (AJOL)

    The radiofrequency dielectric properties of x-irradiated and non-irradiated bovine kidney tissues have been investigated. The relative permittivity α , the dielectric loss factor α , and the a.c conductivity α of the tissues have been measured in the frequency range 1.0 to 50.0 MHz using a Marconi Q-meter, TF 1245 working in ...

  15. Residential characteristics and radiofrequency electromagnetic field exposures from bedroom measurements in Germany

    DEFF Research Database (Denmark)

    Breckenkamp, J; Blettner, M; Schüz, J

    2012-01-01

    The objectives of this study were to assess total exposure to radiofrequency electromagnetic fields (RF-EMF) in bedrooms and the contribution of different radioservices (FM radio, analogue TV and DVB-T, TETRA, GSM900 downlink, GSM1800 downlink, UMTS downlink, DECT, and wireless LAN and blue tooth...

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

    Science.gov (United States)

    Sage, Cindy; Burgio, Ernesto

    2018-01-01

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

  17. Effects of 1.84 GHz radio-frequency electromagnetic field on sperm ...

    African Journals Online (AJOL)

    sunny t

    Full Length Research Paper. Effects of 1.84 GHz radio-frequency electromagnetic field on sperm maturation in epididymis micro- environment. Guangzhou An1*, Jing Li1, Shenglong Xu1, Tao Zhao1, Kangchu Li1, Jiajin Lin1, Yan Zhou1,. Lihua Zeng2, Guozhen Guo2 and Guirong Ding1. 1Department of Radiation Biology, ...

  18. Loop radiofrequency coils for clinical magnetic resonance imaging at 7 tesla

    NARCIS (Netherlands)

    Kraff, Oliver; Kraff, O.

    2011-01-01

    To date, the 7 T magnetic resonance imaging (MRI) scanner remains a pure research system and there is still a long way ahead till full clinical integration. Key challenges are the absence of a body transmit radiofrequency (RF) coil as well as of dedicated RF coils in general, short RF wavelengths of

  19. Comparison of Quadrapolar™ radiofrequency lesions produced by standard versus modified technique: an experimental model.

    Science.gov (United States)

    Safakish, Ramin

    2017-01-01

    Lower back pain (LBP) is a global public health issue and is associated with substantial financial costs and loss of quality of life. Over the years, different literature has provided different statistics regarding the causes of the back pain. The following statistic is the closest estimation regarding our patient population. The sacroiliac (SI) joint pain is responsible for LBP in 18%-30% of individuals with LBP. Quadrapolar™ radiofrequency ablation, which involves ablation of the nerves of the SI joint using heat, is a commonly used treatment for SI joint pain. However, the standard Quadrapolar radiofrequency procedure is not always effective at ablating all the sensory nerves that cause the pain in the SI joint. One of the major limitations of the standard Quadrapolar radiofrequency procedure is that it produces small lesions of ~4 mm in diameter. Smaller lesions increase the likelihood of failure to ablate all nociceptive input. In this study, we compare the standard Quadrapolar radiofrequency ablation technique to a modified Quadrapolar ablation technique that has produced improved patient outcomes in our clinic. The methodology of the two techniques are compared. In addition, we compare results from an experimental model comparing the lesion sizes produced by the two techniques. Taken together, the findings from this study suggest that the modified Quadrapolar technique provides longer lasting relief for the back pain that is caused by SI joint dysfunction. A randomized controlled clinical trial is the next step required to quantify the difference in symptom relief and quality of life produced by the two techniques.

  20. Radiofrequency preserves histoarchitecture and enhances collagen synthesis in experimental tendon injury.

    Science.gov (United States)

    Akamatsu, Flavia Emi; Saleh, Samir Omar; Hojaij, Flávio; Martinez, Carlos Augusto Real; Andrade, Mauro; Teodoro, Walcy Rosolia; Jacomo, Alfredo Luiz

    2016-05-01

    We investigated the action of radiofrequency (RF) on the healing process after inducing experimental lesions of the Achilles tendon in rats. Wistar rats were surgically subjected to bilateral partial transverse sectioning of the Achilles tendon. The right tendon was treated with radiofrequency (RFT), whereas the left tendon served as a control (CT). On the third postoperative day, the rats were divided into three experimental groups consisting of ten rats each, which were treated with monopolar radiofrequency (Tonederm™) until they were sacrificed on the 7th, 14th or 28th days. The histological specimens were studied for inflammatory cell content, collagen types I and III, immunostaining and morphometry. Total collagen were biochemically analyzed and to evalute fibroblast and myofibroblast proliferation by vimentin and α-actin smooth muscle immunohistochemistry methods. Statistical analysis was performed using the Student's t-test, the sign test and the Kruskal-Wallis test to compare tendons treated with radiofrequency with the non-treated tendons (α=5%; α=10%). Larger amounts of collagen I with hydroxyproline content and myofibroblast cells were clearly evident within 7 days (ptendon healing. Clinical studies may include RF among the therapeutic tools in tendinous lesion management.

  1. Effect of percutaneous renal sympathetic nerve radiofrequency ablation in patients with severe heart failure.

    Science.gov (United States)

    Dai, Qiming; Lu, Jing; Wang, Benwen; Ma, Genshan

    2015-01-01

    This study aimed to investigate the clinical feasibility and effects of percutaneous renal sympathetic nerve radiofrequency ablation in patients with heart failure. A total of 20 patients with heart failure were enrolled, aged from 47 to 75 years (63±10 years). They were divided into the standard therapy (n = 10), and renal nerve radiofrequency ablation groups (n = 10). There were 15 males and 5 female patients, including 8 ischemic cardiomyopathy, 8 dilated cardiomyopathy, and 8 hypertensive cardiopathy. All of the patients met the criteria of New York Heart Association classes III-IV cardiac function. Patients with diabetes and renal failure were excluded. Percutaneous renal sympathetic nerve radiofrequency ablation was performed on the renal artery wall under X-ray guidance. Serum electrolytes, neurohormones, and 24 h urine volume were recorded 24 h before and after the operation. Echocardiograms were performed to obtain left ventricular ejection fraction at baseline and 6 months. Heart rate, blood pressure, symptoms of dyspnea and edema were also monitored. After renal nerve ablation, 24 h urine volume was increased, while neurohormone levels were decreased compared with those of pre-operation and standard therapy. No obvious change in heart rate or blood pressure was recorded. Symptoms of heart failure were improved in patients after the operation. No complications were recorded in the study. Percutaneous renal sympathetic nerve radiofrequency ablation may be a feasible, safe, and effective treatment for the patients with severe congestive heart failure.

  2. The Bohm Criterion for Radiofrequency Discharges - a Numerical Verification Based on Poisson Equation

    NARCIS (Netherlands)

    Meijer, P. M.; W. J. Goedheer,

    1993-01-01

    Recently it was shown that, by using the analysis of electrostatic waves entering the plasma-sheath edge, the direct-current (dc) Bohm criterion also holds for discharges under radio-frequency (rf) conditions. In this paper, the influence of Bohm's criterion on the sheath characteristics for

  3. Effects of 2.45 GHz Radiofrequency Radiation Exposures on Normal ...

    African Journals Online (AJOL)

    sickle cell patients. Blood samples were collected for analysis before and after being irradiated with a 2.45 GHz radiofrequency source. The osmotic fragility of the red blood cells, the packed cell volume and percentage haemolysis for irreversibly ...

  4. Ultracold atoms in radio-frequency dressed potentials beyond the rotating-wave approximation

    DEFF Research Database (Denmark)

    Hofferberth, S.; Fischer, B.; Schumm, Thorsten

    2007-01-01

    We study dressed Bose-Einstein condensates in an atom chip radio-frequency trap. We show that in this system sufficiently strong dressing can be achieved to cause the widely used rotating-wave approximation (RWA) to break down. We present a full calculation of the atom-field coupling which shows...

  5. Outcomes after resection and/or radiofrequency ablation for recurrence after treatment of colorectal liver metastases

    NARCIS (Netherlands)

    Hof, J.; Wertenbroek, M. W. J. L. A. E.; Peeters, P. M. J. G.; Widder, J.; Sieders, E.; de Jong, K. P.

    Background: Repeat liver resection for colorectal liver metastases (CRLMs) is possible in a limited number of patients, with radiofrequency ablation (RFA) as an alternative for unresectable CRLMs. The aim of this study was to analyse survival rates with these interventions. Methods: This was a

  6. Percutaneous Radiofrequency Ablation of a Small Renal Mass Complicated by Appendiceal Perforation

    NARCIS (Netherlands)

    Boone, Judith; Bex, Axel; Prevoo, Warner

    2012-01-01

    Percutaneous radiofrequency ablation (RFA) has gained wide acceptance as nephron-sparing therapy for small renal masses in select patients. Generally, it is a safe procedure with minor morbidity and acceptable short-term oncologic outcome. However, as a result of the close proximity of vital

  7. [The new technology of enhanced radiofrequency ablation is safe and effective for treating giant hepatic hemangioma].

    Science.gov (United States)

    Zou, Hua; Yan, Jun; Wu, Yan-xia; Ou, Xia; Li, Xiao-wu; Xia, Feng; Ma, Kuan-sheng; Bie, Ping

    2012-04-01

    To determine the safety and efficacy of the enhanced radiofrequency ablation (RFA) new technology for treatment of giant hepatic hemangiomas. From August 2010 to September 2011, 30 patients with giant hepatic hemangiomas (average diameter: 7.7+/-1.9 cm, range: 5.0 to 12.8 cm) were treated with enhanced RFA. The original lesion diameter, enhanced radiofrequency duration, and cases of RFA-induced burning were recorded. Cases requiring a second RFA treatment were also recorded. Correlation analysis was carried out to determine the association of enhanced RFA with adverse events and change in lesion diameter. The rate of completely destroyed lesions by enhanced RFA was 70.96%, and the total rate of reduced lesions was 87.1%. No severe adverse events occurred. The duration of enhanced radiofrequency correlated positively with the original lesion diameter (r=0.687, P less than 0.01). The enhanced RFA treatment significantly reduced the average lesion diameter (follow-up: 6.2+/-1.8 cm; t=6.417, P less than 0.01). The new minimally-invasive technology of enhanced radiofrequency ablation is effective and safe for treating giant hepatic hemangiomas and produces an obvious, short-term curative effect.

  8. Effects of Multipolar Radiofrequency and Pulsed Electromagnetic Field Treatment for Face and Neck Rejuvenation

    Directory of Open Access Journals (Sweden)

    Thais Cristina Ferraz de Oliveira

    2017-01-01

    Full Text Available Skin aging is a gradual process that leads to wrinkle formation, laxity, and overall changes in skin appearance. In recent years, the demands to noninvasive treatments for facial rejuvenation increased, along with a variety of technologies and devices, such as radiofrequency. The present study aimed to evaluate the clinical effects of a multipolar radiofrequency and pulsed electromagnetic field treatment for face and neck rejuvenation. Eleven patients with mild to moderate grades of photoaging underwent eight radiofrequency and pulsed electromagnetic field treatment sessions, once a week. Clinical photographs were taken before and a week after the end of the treatment, and improvement of facial skin parameters was evaluated by two different investigators. Significant improvement in skin laxity was observed in all eleven patients (100%. Improvement in facial contour was noted in 73% and 100% of patients when analyzed by investigators A and B, respectively. The score for overall improvement in skin condition was 3 ± 0.78 for investigator A and 3.6 ± 0.67 for investigator B. All patients were satisfied with the procedure and noted significant improvement in the skin. The combined multipolar radiofrequency and pulsed electromagnetic field device is effective and safe for treatment of aged skin in Brazilian patients.

  9. Evaluation of microneedling fractional radiofrequency device for treatment of acne scars

    Directory of Open Access Journals (Sweden)

    Byalekere Shivanna Chandrashekar

    2014-01-01

    Full Text Available Background: Various treatment modalities including non-invasive methods such as chemical peels, topical retinoids, microdermabrasion, minimally invasive techniques such as microneedling, fractional lasers, microneedling radiofrequency devices and invasive procedures such as acne scar surgeries and ablative lasers are used for acne scars, each with its own unique advantages and disadvantages. This study is a retrospective assessment of efficacy and safety of microneedling fractional radiofrequency in the treatment of acne scars. Methods: Thirty one patients of skin types III-V with moderate and severe facial acne scarring received four sequential fractional radiofrequency treatments over a period of 6 months with an interval of 6 weeks between each session. Goodman & Baron′s acne scar grading system was used for assessment by a side by side comparison of preoperative and post- operative photographs taken at their first visit and at the end of 3 months after the last session. Results: Estimation of improvement with Goodman and Baron′s Global Acne Scarring System showed that by qualitative assessment of 31 patients with grade 3 and grade 4 acne scars, 80.64% showed improvement by 2 grades and 19.35% showed improvement by 1 grade. Quantitative assessment showed that 58% of the patients had moderate, 29% had minimal, 9% had good and 3% showed very good improvement. Adverse effects were limited to transient pain, erythema, edema and hyperpigmentation. Conclusion: Microneedling fractional radiofrequency is efficacious for the treatment of moderate and severe acne scars.

  10. Multipolar radiofrequency ablation for colorectal liver metastases close to major hepatic vessels

    NARCIS (Netherlands)

    Snoeren, Nikol; Nijkamp, Maarten W.; Berendsen, Tim; Govaert, Klaas M.; van Kessel, Charlotte S.; Borel Rinkes, Inne H M; Van Hillegersberg, Richard

    2015-01-01

    Background: Resection of colorectal liver metastases (CRLM) is often hindered by their location close to the major hepatic vessels. So far, radiofrequency ablation for perivascular tumours was thought to be ineffective and unsafe due to either the heat sink effect or vascular thrombosis. The aim of

  11. Radiofrequency-assisted Liposuction for Arm Contouring: Technique under Local Anesthesia

    Directory of Open Access Journals (Sweden)

    Spero Theodorou, MD

    2013-08-01

    Conclusions: In appropriately selected patients, RFAL arm contouring under local anesthesia represents an alternative procedure with acceptably low morbidity and high patient satisfaction. To achieve consistent results while minimizing complications, consideration to anatomic details, infiltration of the local anesthetic, and application of the radiofrequency energy must be given.

  12. Osteoid osteoma of the spine: CT-guided monopolar radiofrequency ablation

    Energy Technology Data Exchange (ETDEWEB)

    Martel, Jose [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain)], E-mail: jmartel@fhalcorcon.es; Bueno, Angel [Departamento de Diagnostico por Imagen, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain); Nieto-Morales, M Luisa [Servicio de Radiologia, Hospital Universitario de Tenerife (Spain); Ortiz, Eduardo J. [Departamento de Cirugia Ortopedica, Fundacion Hospital Alcorcon, Alcorcon, Madrid (Spain)

    2009-09-15

    CT-guided percutaneous radiofrequency ablation and laser photocoagulation have become the methods of choice for the treatment of all osteoid osteomas except those in contact with neural structures. We report 10 patients with spinal osteoid osteoma adjacent to the neural elements treated with 12 sessions of CT-guided monopolar radiofrequency ablation. The size range of the lesion was 3-14 mm (mean, 7.5 mm) and the distance between the nidus and the adjacent spinal cord or nerve root was 2-12 mm (mean, 5 mm). No intact cortex between the tumor and the spinal cord or nerve roots constituted an exclusion criterion because of a higher risk of undesirable neurotoxic effects. Patients were under general anesthesia. After location of the lesion, a 11G-bone biopsy was introduced into the nidus. The radiofrequency electrode was inserted through the biopsy needle and heated at 90 deg. C for 4 min. Primary success was obtained in eight patients. At follow-up (mean, 19.5 months; range, 6-24 months), pain persisted in two patients after 2 months. Both of them were re-treated. All patients are currently pain-free and complications were not detected. In our opinion, radiofrequency ablation can also be considered the treatment of choice for spinal osteoid osteoma.

  13. Indication of the radiofrequency induced lesion size by pre-ablation measurements

    DEFF Research Database (Denmark)

    Stagegaard, Niels; Petersen, Helen Høgh; Chen, Xu

    2005-01-01

    BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool for asses......BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool...... for assessing these factors prior to ablation may indicate the lesion size which will be obtained for any given catheter position. METHODS AND RESULTS: Radiofrequency ablation was performed in vitro on strips of left ventricular porcine myocardium during two different levels of convective cooling (0 or 0.1 m......, during unchanged conditions, radiofrequency ablation was performed as either temperature-controlled, power-controlled or irrigated tip ablation and lesion size was determined. DeltaIMP increased significantly (P

  14. Increased resting heart rate following radiofrequency catheter ablation for atrial fibrillation

    DEFF Research Database (Denmark)

    Nilsson, Brian; Chen, Xu; Pehrson, Steen

    2005-01-01

    AIM: Sinus tachycardia has been observed following radiofrequency (RF) catheter ablation for various kinds of supraventricular tachycardia. This study is aimed at determining the occurrence of changes in sinus-rhythm heart rate (HR) after pulmonary vein (PV) isolation in patients with paroxysmal...

  15. Hip fracture after radiofrequency ablation therapy for bone tumors : two case reports

    NARCIS (Netherlands)

    Dierselhuis, Edwin F.; Jutte, Paul C.; van der Eerden, Pepijn J. M.; Suurmeijer, Albert J. H.; Bulstra, Sjoerd K.

    2010-01-01

    Radiofrequency ablation (RFA) has become a valuable therapeutic modality in cancer treatment over the last decade. In orthopedic surgery, RFA is used for the treatment of benign bone tumors and bone metastases. Complications are rare and, to our knowledge, bone fracture as a complication due solely

  16. Parálisis cerebral Cerebral palsy

    Directory of Open Access Journals (Sweden)

    Jorge Malagon Valdez

    2007-01-01

    Full Text Available El término parálisis cerebral (PC engloba a un gran número de síndromes neurológicos clínicos, de etiología diversa. Estos síndromes se caracterizan por tener una sintomatología común: los trastornos motores. Algunos autores prefieren manejar términos como "encefalopatía fija", "encefalopatías no evolutivas". Se mencionan la utilidad de programas de intervención temprana y métodos especiales de rehabilitación, así como el manejo de las deficiencias asociadas como la epilepsia, deficiencia mental, trastornos del lenguaje, audición, visión, déficit de la atención que mejoran el pronóstico de manera significativa. El pronóstico también depende de la gravedad del padecimiento y de las manifestaciones asociadas.The term cerebral palsy (CP, is used for a great number of clinical neurological syndromes. The syndromes are characterized by having a common cause, motor defects. It is important, because they can cause a brain damage by presenting motor defects and some associated deficiencies, such as mental deficiency, epilepsy, language and visual defects and pseudobulbar paralysis, with the nonevolving fact. Some authors prefer using terms such as "non-evolving encephalopathies". In the treatment the utility of prevention programs of early stimulation and special rehabilitation methods, and treatment of associated deficiencies such as epilepsy, mental deficiency, language, audition and visual problems, and the attention deficit improve the prognosis in an important way. The prognosis depends on the severity of the disease and the associated manifestations.

  17. Acute and chronic effects of epicardial radiofrequency applications delivered on epicardial coronary arteries.

    Science.gov (United States)

    Viles-Gonzalez, Juan F; de Castro Miranda, Reynaldo; Scanavacca, Mauricio; Sosa, Eduardo; d'Avila, Andre

    2011-08-01

    Epicardial coronary injury is by far the most feared complication of epicardial ablation. Little information is available regarding the chronic effects of delivering radiofrequency in the vicinity of large coronary vessels, and the long-term impact of this approach for mapping and ablation on epicardial vessel integrity is poorly understood. Therefore, the aim of this study was to characterize the acute and chronic histopathologic changes produced by in vivo epicardial pulses of radiofrequency ablation on coronary artery of porcine hearts. Seven pigs underwent a left thoracotomy. The catheter was sutured adjacent to the left anterior descending artery and left circumflex artery, and 20 pulses of radiofrequency energy were applied. Radiofrequency lesions located no more than 1 mm of the vessel were used for this analysis. Three animals were euthanized 20 days (acute phase) after the procedure and 4 animals after 70 days (chronic phase). The following parameters were obtained in each vessel analyzed: (1) internal and external perimeter; (2) vessel wall thickness; (3) tunica media thickness, and (4) tunica intima thickness. The presence of adipose tissue around the coronary arteries, the distance between the artery and the epicardium, and the anatomic relationship of the artery with the coronary vein was also documented for each section. Sixteen of 20 (80%) sections analyzed, showed intimal thickening with a mean of 0.18 ± 0.14 mm compared with 0.13 ± 0.16 mm in the acute phase (P = 0.331). The mean tunica media thickness was 0.25 ± 0.10 mm in the chronic phase animals compared with 0.18 ± 0.03 mm in the acute phase animals (P = 0.021). A clear protective effect of pericardial fat and coronary veins was also present. A positive correlation between depth of radiofrequency lesion and the degree of vessel injury expressed as intimal and media thickening (P = 0.001) was present. A negative correlation was identified (r = -0.83; P = 0.002) between intimal thickening

  18. Bovine pars tuberalis secretions release growth hormone from rat pars distalis of pituitary gland.

    Science.gov (United States)

    Lafarque, Martha María; Ezquer, Marcelo; Aguado, Luis Inocencio; Oliveros, Liliana Beatriz

    2004-08-01

    The pituitary pars tuberalis (PT) is characterized by PT-specific secretory cells which have raised the possibility of an endocrine function for this portion of adenohypophysis. To investigate the effect of the secretion of bovine PT cells into culture medium on growth hormone (GH) response of dispersed pars distalis (PD) cells of rats. 48-hour culture medium of all PT cells at 1 microg of protein concentration induced the greatest GH release from PD cells. After PT cells separation on a discontinuos Percoll gradient and culturing, only the culture medium of cells from 50 and 60% Percoll strength released GH from PD cells. Therefore, cells from 50 and 60% strenght Percoll were cultured together. Only 0.2 mg protein of this culture medium was required to induce the maximal GH release from PD cells, suggesting that these cells could be responsible for producing the factor(s) which affect PD somatotrophe cells. After protein separation by 12% SDS-PAGE of this PT culture medium bands were eluted. The biological activity, measured as ng/ml of GH from PD cells, corresponded to a protein(s) of molecular weight between 45 and 66 kDal. The results indicate that there is an active proteic factor(s) secreted by the PT that acts upon PD cells to stimulate GH release and that PD could be an effector organ for some secretory product(s) of the PT.

  19. Récolte et consommation de pollen par les abeilles

    OpenAIRE

    Odoux, Jean Francois

    2005-01-01

    La récolte de pollen par les abeilles fait appel à des organes spécialisés de l'abeille, comme celle du nectar. Par contre, elle est régie par de très nombreux facteurs, en fonction des ressources, bien sûr, mais aussi des besoins de la colonie, alors que son attractivité n'est pas toujours en rapport avec la qualité. Ce texte décrit le contexte de l'utilisation du pollen par les abeilles, de la récolte à la digestion, d'après une synthèse bibliographique.

  20. PARS: Programs for Analysis and Resizing of Structures, user manual

    Science.gov (United States)

    Haftka, R. T.; Prasad, B.; Tsach, U.

    1979-01-01

    PARS processors and their use, flutter analysis, sensitivity analysis for stresses, and resizing are presented. Design variable definition and interface with finite element model, static constraints and their derivatives, flutter derivatives, and optimization are discussed.

  1. First-in-human uPAR PET

    DEFF Research Database (Denmark)

    Persson, Morten; Skovgaard, Dorthe; Brandt-Larsen, Malene

    2015-01-01

    A first-in-human clinical trial with Positron Emission Tomography (PET) imaging of the urokinase-type plasminogen activator receptor (uPAR) in patients with breast, prostate and bladder cancer, is described. uPAR is expressed in many types of human cancers and the expression is predictive...... of invasion, metastasis and indicates poor prognosis. uPAR PET imaging therefore holds promise to be a new and innovative method for improved cancer diagnosis, staging and individual risk stratification. The uPAR specific peptide AE105 was conjugated to the macrocyclic chelator DOTA and labeled with (64)Cu...... for targeted molecular imaging with PET. The safety, pharmacokinetic, biodistribution profile and radiation dosimetry after a single intravenous dose of (64)Cu-DOTA-AE105 were assessed by serial PET and computed tomography (CT) in 4 prostate, 3 breast and 3 bladder cancer patients. Safety assessment...

  2. Peptide-Based Optical uPAR Imaging for Surgery

    DEFF Research Database (Denmark)

    Juhl, Karina; Christensen, Anders; Persson, Morten

    2016-01-01

    Near infrared intra-operative optical imaging is an emerging technique with clear implications for improved cancer surgery by enabling a more distinct delineation of the tumor margins during resection. This modality has the potential to increase the number of patients having a curative radical...... tumor resection. In the present study, a new uPAR-targeted fluorescent probe was developed and the in vivo applicability was evaluated in a human xenograft mouse model. Most human carcinomas express high level of uPAR in the tumor-stromal interface of invasive lesions and uPAR is therefore considered...... an ideal target for intra-operative imaging. Conjugation of the flourophor indocyanine green (ICG) to the uPAR agonist (AE105) provides an optical imaging ligand with sufficiently high receptor affinity to allow for a specific receptor targeting in vivo. For in vivo testing, human glioblastoma xenograft...

  3. Croissance epitaxiale de GaAs sur substrats de Ge par epitaxie par faisceaux chimiques

    Science.gov (United States)

    Belanger, Simon

    La situation energetique et les enjeux environnementaux auxquels la societe est confrontee entrainent un interet grandissant pour la production d'electricite a partir de l'energie solaire. Parmi les technologies actuellement disponibles, la filiere du photovoltaique a concentrateur solaire (CPV pour concentrator photovoltaics) possede un rendement superieur et mi potentiel interessant a condition que ses couts de production soient competitifs. La methode d'epitaxie par faisceaux chimiques (CBE pour chemical beam epitaxy) possede plusieurs caracteristiques qui la rendent interessante pour la production a grande echelle de cellules photovoltaiques a jonctions multiples a base de semi-conducteurs III-V. Ce type de cellule possede la meilleure efficacite atteinte a ce jour et est utilise sur les satellites et les systemes photovoltaiques a concentrateur solaire (CPV) les plus efficaces. Une des principales forces de la technique CBE se trouve dans son potentiel d'efficacite d'utilisation des materiaux source qui est superieur a celui de la technique d'epitaxie qui est couramment utilisee pour la production a grande echelle de ces cellules. Ce memoire de maitrise presente les travaux effectues dans le but d'evaluer le potentiel de la technique CBE pour realiser la croissance de couches de GaAs sur des substrats de Ge. Cette croissance constitue la premiere etape de fabrication de nombreux modeles de cellules solaires a haute performance decrites plus haut. La realisation de ce projet a necessite le developpement d'un procede de preparation de surface pour les substrats de germanium, la realisation de nombreuses sceances de croissance epitaxiale et la caracterisation des materiaux obtenus par microscopie optique, microscopie a force atomique (AFM), diffraction des rayons-X a haute resolution (HRXRD), microscopie electronique a transmission (TEM), photoluminescence a basse temperature (LTPL) et spectrometrie de masse des ions secondaires (SIMS). Les experiences ont permis

  4. Differences in middle ear ventilation disorders between pars flaccida and pars tensa cholesteatoma in sonotubometry and patterns of tympanic and mastoid pneumatization.

    Science.gov (United States)

    Shinnabe, Akihiro; Hara, Mariko; Hasegawa, Masayo; Matsuzawa, Shingo; Kanazawa, Hiromi; Kanazawa, Takeharu; Yoshida, Naohiro; Iino, Yukiko

    2012-07-01

    To investigate differences in middle ear ventilation mechanisms between pars flaccida and pars tensa cholesteatoma. Retrospective case review. A referral hospital otolaryngology department. Sixty-six ears with pars flaccida cholesteatoma (mean age, 45.7 yr) and 19 ears with pars tensa cholesteatoma (mean age, 58.8 yr) were included. Patients with totally adhesive tympanic membranes or mixed-type cholesteatoma were excluded. Patients underwent canal wall down tympanoplasty with canal reconstruction. The canal wall was reconstructed with tragal or conchal cartilage and cortical bone grafts. Habitual sniffing, preoperative sonotubometry results, mastoid pneumatization (maturation), and postoperative aeration around the stapes were investigated. Preoperative mastoid pneumatization and postoperative aeration around the stapes were measured on computed tomography scans. Ten (15.4%) of 65 patients with pars flaccida cholesteatoma and 3 (15.7%) of 19 patients with pars tensa cholesteatoma were habitual sniffers (p = 0.5). Preoperative sonotubometry indicated that a patulous pattern was more common in ears with pars flaccida than pars tensa cholesteatoma (42.8% versus 7.1%, p pars tensa than pars flaccida cholesteatoma (85.8% versus 42.8%, p pars flaccida than pars tensa cholesteatoma (p pars flaccida and pars tensa cholesteatoma.

  5. Prise en charge des intoxications par envenimation chez les enfants ...

    African Journals Online (AJOL)

    Les signes cliniques étaient dominés par les douleurs (98%) suivies des hémorragies (73,80%) pour les morsures de serpent, la douleur pour les piqures de scorpion (100%) et les oedèmes pour les piqures d'abeilles (100%). Les cas de morsure de serpent ont été traités par le sérum antivenimeux polyvalent. Conclusion: ...

  6. Lumbar vertebral body and pars fractures following laminectomy

    OpenAIRE

    Yadhati, Akshay; Kurra, Swamy; Tallarico, Richard A.; Lavelle, William F.

    2017-01-01

    Abstract A 56-year-old alcoholic male incurred L5 vertebral body and bilateral L4 pars fractures with progressive L4 on L5 anterolisthesis following low-energy falls while intoxicated. Recently, he had a L3?S1 laminectomy for lumbar spinal stenosis with claudication. Preoperative imaging and radiographs were negative for pars defects and instability, so an isolated decompressive surgery was performed. Following low-energy falls, his outpatient work-up revealed fractures through the bilateral ...

  7. Radiofrequency ablation of the supra-orbital nerve in the treatment algorithm of hemicrania continua.

    Science.gov (United States)

    Weyker, Paul; Webb, Christopher; Mathew, Leena

    2012-01-01

    Hemicrania continua (HC) is an uncommon primary headache disorder in which the diagnosis centers on unilaterality and its absolute responsiveness to indomethacin. We describe 3 patients with a long standing history of headache diagnosed as hemicrania continua. There was profound response to indomethacin which was limited by side effects. In one patient the therapy with indomethacin was limited secondary to co-morbidities. Initial diagnostic blockade provided significant relief of symptoms based on which radio-frequency ablation of the supraorbital nerve was performed with substantial improvement in symptoms. Traditionally, hemicrania continua has been managed exclusively with oral analgesics and is defined by its singular response to indomethacin. Radio-frequency ablation (RFA) has been reported in the literature for multiple indications. This case series is unique in that it describes 3 patients diagnosed with hemicrania continua with pain referred in the supraorbital nerve distribution, who underwent radiofrequency ablation of the supraorbital nerve with resultant resolution of headaches. Traditionally, hemicrania continua has been managed exclusively with oral analgesics and is defined by its singular response to indomethacin. This report is unique in that it describes three patients diagnosed with hemicrania continua with pain referred in the supraorbital nerve distribution who underwent radiofrequency ablation of the supraorbital nerve with resultant resolution of headaches. After the RFA medical management was minimal to none in both patients. Though the utility and cost efficacy of RFA of peripheral nerves needs to be confirmed in well-designed trials we present these cases as an example of how this minimally invasive technique can safely provide analgesia in a difficult to treat cephalgia. Moreover if precise anatomical localization of the headache is possible then diagnostic blockade of the appropriate peripheral nerve may be performed followed by

  8. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids.

    Directory of Open Access Journals (Sweden)

    Flavien Pillet

    Full Text Available Bacterial centromeres-also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA-the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres.

  9. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids

    Science.gov (United States)

    Pillet, Flavien; Passot, Fanny Marie

    2017-01-01

    Bacterial centromeres–also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA—the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi) mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres. PMID:28562673

  10. Transurethral radiofrequency collagen denaturation for the treatment of women with urinary incontinence.

    Science.gov (United States)

    Kang, Diana; Han, Julia; Neuberger, Molly M; Moy, M Louis; Wallace, Sheila A; Alonso-Coello, Pablo; Dahm, Philipp

    2015-03-18

    Transurethral radiofrequency collagen denaturation is a relatively novel, minimally invasive device-based intervention used to treat individuals with urinary incontinence (UI). No systematic review of the evidence supporting its use has been published to date. To evaluate the efficacy of transurethral radiofrequency collagen denaturation, compared with other interventions, in the treatment of women with UI.Review authors sought to compare the following.• Transurethral radiofrequency collagen denaturation versus no treatment/sham treatment.• Transurethral radiofrequency collagen denaturation versus conservative physical treatment.• Transurethral radiofrequency collagen denaturation versus mechanical devices (pessaries for UI).• Transurethral radiofrequency collagen denaturation versus drug treatment.• Transurethral radiofrequency collagen denaturation versus injectable treatment for UI.• Transurethral radiofrequency collagen denaturation versus other surgery for UI. We conducted a systematic search of the Cochrane Incontinence Group Specialised Register (searched 19 December 2014), EMBASE and EMBASE Classic (January 1947 to 2014 Week 50), Google Scholar and three trials registries in December 2014, along with reference checking. We sought to identify unpublished studies by handsearching abstracts of major gynaecology and urology meetings, and by contacting experts in the field and the device manufacturer. Randomised and quasi-randomised trials of transurethral radiofrequency collagen denaturation versus no treatment/sham treatment, conservative physical treatment, mechanical devices, drug treatment, injectable treatment for UI or other surgery for UI in women were eligible. We screened search results and selected eligible studies for inclusion. We assessed risk of bias and analysed dichotomous variables as risk ratios (RRs) with 95% confidence intervals (CIs) and continuous variables as mean differences (MDs) with 95% CIs. We rated the quality of

  11. The urokinase receptor (uPAR) and the uPAR-associated protein (uPARAP/Endo180)

    DEFF Research Database (Denmark)

    Behrendt, Niels

    2004-01-01

    The breakdown of the barriers formed by extracellular matrix proteins is a pre-requisite for all processes of tissue remodeling. Matrix degradation reactions take part in specific physiological events in the healthy organism but also represent a crucial step in cancer invasion. These degradation...... processes involve a highly organized interplay between proteases and their cellular binding sites as well as specific substrates and internalization receptors. This review article is focused on two components, the urokinase plasminogen activator receptor (uPAR) and the uPAR-associated protein (uPARAP, also...... designated Endo180), that are considered crucially engaged in matrix degradation. uPAR and uPARAP have highly diverse functions, but on certain cell types they interact with each other in a process that is still incompletely understood. uPAR is a glycosyl-phosphatidylinositol-anchored glycoprotein...

  12. Attenuated vasodilator effectiveness of protease-activated receptor 2 agonist in heterozygous par2 knockout mice.

    Directory of Open Access Journals (Sweden)

    John C Hennessey

    Full Text Available Studies of homozygous PAR2 gene knockout mice have described a mix of phenotypic effects in vitro and in vivo. However, there have been few studies of PAR2 heterozygous (wild-type/knockout; PAR2-HET mice. The phenotypes of many hemi and heterozygous transgenic mice have been described as intermediates between those of wild-type and knockout animals. In our study we aimed to determine the effects of intermediary par2 gene zygosity on vascular tissue responses to PAR2 activation. Specifically, we compared the vasodilator effectiveness of the PAR2 activating peptide 2-furoyl-LIGRLO-amide in aortas of wild-type PAR2 homozygous (PAR2-WT and PAR2-HET mice. In myographs under isometric tension conditions, isolated aortic rings were contracted by alpha 1-adrenoeceptor agonist (phenylephrine, and thromboxane receptor agonist (U46619 and then relaxation responses by the additions of 2-furoyl-LIGRLO-amide, acetylcholine, and nitroprusside were recorded. A Schild regression analysis of the inhibition by a PAR2 antagonist (GB-83 of PAR2 agonist-induced aortic ring relaxations was used to compare receptor expression in PAR2-WT to PAR2-HET. PAR2 mRNA in aortas was measured by quantitative real-time PCR. In aortas contracted by either phenylephrine or U46619, the maximum relaxations induced by 2-furoyl-LIGRLO-amide were less in PAR2-HET than in the gender-matched PAR2-WT. GB-83 was 3- to 4-fold more potent for inhibition of 2fly in PAR2-HET than in PAR2-WT. PAR2 mRNA content of aortas from PAR2-HET was not significantly different than in PAR2-WT. Acetylcholine- and nitroprusside-induced relaxations of aortas from PAR2-HET were not significantly different than in PAR2-WT and PAR2 knockout. An interesting secondary finding was that relaxations induced by agonists of PAR2 and muscarinic receptors were larger in females than in males. We conclude that the lower PAR2-mediated responses in PAR2-HET aortas are consistent with evidence of a lower quantity of functional

  13. Une terreur par l’image

    Directory of Open Access Journals (Sweden)

    Annie DULONG

    2011-09-01

    Full Text Available Si d’autres événements — Hiroshima, la découverte des camps de concentration, la chute du mur de Berlin — ont, au cours du XXe siècle, marqué suffisamment l’imaginaire pour trouver leur réponse dans des œuvres d’art, le 11 septembre 2001 pose la question de la fictionnalisation autrement : il ne s’agit plus tant de combler les manques de la représentation, liés à l’absence d’images ou au délai dans leur dévoilement, mais bien de composer avec l’omniprésence d’une représentation martelée à la télévision et sur Internet. Que cette représentation soit partielle, tronquée et qu’il lui manque la présence des corps, ces grands absents des photographies et des images tournées par les journalistes, ne change rien au fait que c’est avec le trop-plein que les artistes doivent maintenant négocier.Cet article s’intéresse aux romans qui traitent l’événement de front au lieu de l’aborder sur un mode mineur, et a pour objectif de tracer un portrait de la représentation des médias dans les romans du 11 septembre 2001. Ces romans, outre le fait qu’ils traitent des événements de New York, ont comme point commun un personnage, ou décor : les médias, représentés par la télévision, l’Internet, les photographies de presse, interviennent dans les récits d’une manière significative et témoignent de la force brute des images. À travers une étude de certains des mécanismes à l’œuvre dans The Writing on the Wall (Lynne Sharon Schwartz, Extremely Loud and Incredibly Close (Jonathan Safran Foer, Falling Man (Don DeLillo et A Disorder Peculiar to the Country (Ken Kalfus, il s’agira de proposer des réponses à ces quelques questions : quel rôle les médias jouent-ils, et comment participent-ils au récit ? Quelle pression les images exercent-elles sur les personnages ? Que révèlent les personnages enfants dans leur rapport aux médias ? Quelle critique, finalement, les romans

  14. Serum suPAR in patients with FSGS: trash or treasure?

    NARCIS (Netherlands)

    Maas, R.J.H.; Deegens, J.K.J.; Wetzels, J.F.M.

    2013-01-01

    The urokinase-type plasminogen activator receptor (uPAR) has important functions in cell migration. uPAR can be shed from the cell membrane resulting in soluble uPAR (suPAR). Further cleavage gives rise to shorter fragments with largely unknown functions. Recent studies have demonstrated that both

  15. Outcomes from a prospective trial of endoscopic radiofrequency ablation of early squamous cell neoplasia of the esophagus

    NARCIS (Netherlands)

    Bergman, Jacques J. G. H. M.; Zhang, Yue-Ming; He, Shun; Weusten, Bas; Xue, Liyan; Fleischer, David E.; Lu, Ning; Dawsey, Sanford M.; Wang, Gui-Qi

    2011-01-01

    Radiofrequency ablation (RFA) is safe and effective for eradicating neoplasia in Barrett's esophagus. To evaluate RFA for eradicating early esophageal squamous cell neoplasia (ESCN) defined as moderate-grade squamous intraepithelial neoplasia (MGIN) and high-grade squamous intraepithelial neoplasia

  16. Combined use of radioiodine therapy and radiofrequency ablation in treating postsurgical thyroid remnant of differentiated thyroid carcinoma

    Directory of Open Access Journals (Sweden)

    Bin Long

    2015-01-01

    Conclusion: Combined use of RAI therapy and radiofrequency ablation in treating excessive postsurgical thyroid remnant of DTC can be an effective approach and avoids re-operation. Long-term efficacy monitoring would further determine its feasibility.

  17. Combined pars plana vitrectomy-scleral buckle versus pars plana vitrectomy for proliferative vitreoretinopathy.

    Science.gov (United States)

    Lai, Frank H P; Lo, Ernie C F; Chan, Vesta C K; Brelen, Mårten; Lo, Wai Ling; Young, Alvin L

    2016-04-01

    The purpose of the study is to evaluate the surgical outcomes of combined pars plana vitrectomy-scleral buckle (PPV-SB) versus pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment complicated with proliferative vitreoretinopathy (PVR). One thousand one hundred and seventy four patients with rhegmatogenous retinal detachment surgery between January 2002 and December 2013 were retrospectively reviewed. Patients with grade C PVR treated with either combined PPV-SB or PPV alone were included in the study. Study outcomes included single surgery anatomic success rate and postoperative visual outcome at 12 months postoperatively. Seventy-seven patients with grade C PVR were identified for analysis. At the end of 12-month follow-up, 80.5 % eyes (33/41) in the PPV-SB group and 58.3 % eyes (21/36) in the PPV group achieved single surgery anatomical success. In a multiple logistic regression model, none of the baseline variables (age, gender, macula status, grade of PVR, extent of detachment, presence of vitreous hemorrhage, lens status, status of high myopia) nor types of retinal detachment surgery (use of scleral buckle, barrier endolaser, 360 degree endolaser, cryopexy, retinectomy, tamponade agent, phacoemulsification) had significant effect on single surgery anatomical success. The post-treatment mean logMAR visual acuity of the PPV-SB group was 1.58 ± 0.58 and the PPV group was 1.57 ± 0.61. There was no significant difference in the postoperative visual acuity between the two groups (P = 0.849). For patients with grade C PVR, PPV-SB did not demonstrate a superiority over PPV alone in achieving single surgery anatomical success.

  18. Pars planitis: Epidemiology, clinical characteristics, management and visual prognosis

    Directory of Open Access Journals (Sweden)

    Pinar Cakar Ozdal

    2015-01-01

    Full Text Available Pars planitis is an idiopathic chronic intermediate uveitis which predominantly affects children and adolescents, and accounts for 5-26.7% of pediatric uveitis. Although an autoimmune process with a genetic predisposition has been suggested, its etiology still remains unknown. The most common presenting symptoms are floaters and blurred vision. Diffuse vitreous cells, haze, snowballs and snowbanks are typical findings of pars planitis. Peripheral retinal vasculitis, optic disc edema and anterior segment inflammation are other well-known findings. Although pars planitis is known to be a benign form of uveitis in most cases, it may become a potentially blinding disease due to complications including cataract, cystoid macular edema, vitreous opacities and optic disc edema. Cystoid macular edema is the most common cause of visual morbidity. Band keratopathy, epiretinal membrane formation, vitreous condensation, neovascularizations, vitreous hemorrhage, retinal detachment, cyclitic membranes, glaucoma and amblyopia may develop as a consequence of the chronic course of the disease. Exclusion of infectious and non-infectious causes which may present with intermediate uveitis is of utmost importance before starting treatment. Treatment of pars planitis has been a controversial issue. There is no consensus specifically for treatment of cases with minimal inflammation and relatively good visual acuity. However, current experience shows that pars planitis may cause severe inflammation and needs an aggressive treatment. A stepladder approach including corticosteroids, immunosupressive agents, anti-tumor necrosis factor-alpha and pars plana vitrectomy and/or laser photocoagulation is the most commonly used method for treatment of pars planitis. Adequate control of inflammation and prompt detection of associated complications are crucial in order to improve the overall prognosis of the disease.

  19. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned.

  20. Pars Planitis: Epidemiology, Clinical Characteristics, Management and Visual Prognosis.

    Science.gov (United States)

    Ozdal, Pinar Cakar; Berker, Nilufer; Tugal-Tutkun, Ilknur

    2015-01-01

    Pars planitis is an idiopathic chronic intermediate uveitis which predominantly affects children and adolescents, and accounts for 5-26.7% of pediatric uveitis. Although an autoimmune process with a genetic predisposition has been suggested, its etiology still remains unknown. The most common presenting symptoms are floaters and blurred vision. Diffuse vitreous cells, haze, snowballs and snowbanks are typical findings of pars planitis. Peripheral retinal vasculitis, optic disc edema and anterior segment inflammation are other well-known findings. Although pars planitis is known to be a benign form of uveitis in most cases, it may become a potentially blinding disease due to complications including cataract, cystoid macular edema, vitreous opacities and optic disc edema. Cystoid macular edema is the most common cause of visual morbidity. Band keratopathy, epiretinal membrane formation, vitreous condensation, neovascularizations, vitreous hemorrhage, retinal detachment, cyclitic membranes, glaucoma and amblyopia may develop as a consequence of the chronic course of the disease. Exclusion of infectious and non-infectious causes which may present with intermediate uveitis is of utmost importance before starting treatment. Treatment of pars planitis has been a controversial issue. There is no consensus specifically for treatment of cases with minimal inflammation and relatively good visual acuity. However, current experience shows that pars planitis may cause severe inflammation and needs an aggressive treatment. A stepladder approach including corticosteroids, immunosupressive agents, anti-tumor necrosis factor-alpha and pars plana vitrectomy and/or laser photocoagulation is the most commonly used method for treatment of pars planitis. Adequate control of inflammation and prompt detection of associated complications are crucial in order to improve the overall prognosis of the disease.

  1. PH motifs in PAR1&2 endow breast cancer growth

    OpenAIRE

    Kancharla, A.; Maoz, M.; Jaber, M.; Agranovich, D.; Peretz, T.; Grisaru-Granovsky, S.; Uziely, B.; Bar-Shavit, R.

    2015-01-01

    Although emerging roles of protease-activated receptor1&2 (PAR1&2) in cancer are recognized, their underlying signalling events are poorly understood. Here we show signal-binding motifs in PAR1&2 that are critical for breast cancer growth. This occurs via the association of the pleckstrin homology (PH) domain with Akt/PKB as a key signalling event of PARs. Other PH-domain signal-proteins such as Etk/Bmx and Vav3 also associate with PAR1 and PAR2 through their PH domains. PAR1 and PAR2 bind wi...

  2. Micropuntura com radiofrequência no tratamento da ceratopatia bolhosa sintomática Micropuncture with radiofrequency for the treatment of symptomatic bullous keratopathy

    Directory of Open Access Journals (Sweden)

    José Ricardo Carvalho Lima Rehder

    2010-06-01

    Full Text Available OBJETIVO: Avaliar o efeito da micropuntura com radiofrequência no tratamento dos pacientes portadores de ceratopatia bolhosa sintomática. MÉTODOS: Estudo prospectivo em 10 pacientes com ceratopatia bolhosa sintomática e baixa acuidade visual. Micropunturas com radiofrequência foram realizadas em estroma anterior nas áreas com descompensação epitelial. A evolução dos pacientes foi realizada através de dados clínicos (biomicroscopia, paquimetria, tonometria e estesiometria e graduação de sintomas (intensidade da dor, sensação de corpo estranho, fotofobia e insônia devido à dor. RESULTADOS: A comparação dos sintomas antes do tratamento e no pós-operatório apresentou redução da sensação de corpo estranho, da intensidade da dor e na insônia em mais de 90% dos pacientes. A medida da sensibilidade corneana pelo estesiômetro de Cocher Bonnet apresentou uma redução da sensibilidade, entre o pré tratamento e o pós de 1 semana, entre 0,5 a 2, em 5 pacientes . A comparação do pré-tratamento com o pós-tardio apresentou aumento na sensibilidade corneana em 07 pacientes variando de 0,5 a 2. A avaliação de espessura corneana através do exame de paquimetria ultra- sônica e a medida de pressão intraocular dos pacientes através do tonômetro de aplanação de Goldman não obtiveram diferenças significativas. CONCLUSÃO: A micropuntura com radiofrequência mostrou-se um tratamento válido no controle dos sintomas da ceratopatia bolhosa principalmente na redução de sintomas como dor e sensação de corpo estranho.PURPOSE: Evaluate the effect of micro puncture with radiofrequency as treatment of symptomatic patients with bullous keratopathy. METHODS: Prospective study in 10 pacients with syntomatic bullous keratopathy and low vision. Micro puncture with radiofrequency was made in areas of the anterior stromal that had an epithelial descompensation. The evaluation of the patients was realized trough clinical examinations

  3. [Arthroscope monitored solution of adult intramuscular injection associated gluteal muscle contracture by radiofrequency].

    Science.gov (United States)

    Liu, Yu-Jie; Xue, Jing; Zhou, Mi; Wang, Zhi-Gang; Li, Zhong-Li; Cai, Xu; Wei, Min; Wang, Yan; Zhu, Juan-Li

    2008-07-01

    To evaluate the result of releasing adult intramuscular injection associated gluteal muscle contracture under the monitor of arthroscope by radiofrequency probe. From June 2001 to June 2005, 108 cases of bilateral gluteal muscle contracture were treated with radiofrequency colation under the arthroscope and solution with an average age of 24 years (from 18 to 40 years). There were 57 males and 51 females. Preoperatively, the course of the outline of the femur greater trochanter the sciatic nerve in buttocks and the area of gluteal muscle contracture were marked. With the patients firmly anchored in the straight lateral position, normal saline (which contains Adnephrin) was injected between the surface of contracted gluteus and subcutaneous fat to reduce bleeding in operation. The ports for the motorized shaver and radiofrequency probe were located at the edge of gluteal muscle contracture and were 5 mm superior to the greater trochanter. The 6 mm diameter port for the arthroscope was 3 cm inferior to the greater trochanter. Space was made between contracture bands and overlying subcutaneous tissue with a periosteal elevator by blunt dissection. After the anterior and posterior edge of the contracture bands were fully revealed, normal saline were filled in the space. With the monitor of arthroscope, the procedures were: removing fatty tissue from the surface of the contracture bands with motorized shaver, then cutting off the contracture bands curve and carefully probing and cutting off contracture bands which were mixed in gluteus maximus with radiofrequency probe, finally hemostasis by radiofrequency probe. In the operation flexion, adduction, internal rotation and straightening hip joint were repeated, until it got normal range of motion without snap and bleeding. Results One hundred and one patients were followed up with an average of 19 months. According to a comprehensive evaluating system, 91 cases were excellent, 7 were good, and 3 were fair. No infection

  4. Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

    Energy Technology Data Exchange (ETDEWEB)

    Anfinsen, Ole-Gunnar

    1999-07-01

    The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks

  5. A measurement method of time jitter of a laser pulse with respect to the radio-frequency wave phase in a photocathode radio-frequency gun

    CERN Document Server

    Liu Sheng Guang; Wang Ming Kai

    2002-01-01

    In a photo-cathode radio-frequency (rf) gun, the micro-bunched charge output from the gun is dependent linearly on the laser injection phase, due to the Scottay effect in the process of photoemission and the procedure of the electron longitudinal acceleration. Based on this principle, a new method is proposed, which should be utilized to measure the time jitter between the driving laser pulse and the rf phase with a very high resolution of a few tens of femto-seconds

  6. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  7. Plasma suPAR is lowered by smoking cessation

    DEFF Research Database (Denmark)

    Eugen-Olsen, Jesper; Ladelund, Steen; Sørensen, Lars Tue

    2016-01-01

    , in smokers, predictive of long-term lung cancer development. Whether smoking cessation impacts the suPAR level is unknown. MATERIALS AND METHODS: Forty-eight smokers were randomized into three groups of 16: (i) continued to smoke 20 cigarettes per day, (ii) refrained from smoking and used transdermal...... nicotine patches and (iii) refrained from smoking and used placebo patches. Nonsmokers were included for comparison. suPAR and C-reactive protein (CRP) levels were measured by ELISA. RESULTS: At baseline, the suPAR level was significantly higher in the 48 smokers (median 3·2 ng mL, IQR (2·5-3·9)) than...... in 46 never smokers (1·9 ng/mL (1·7-2·2)). In smokers randomized to smoking cessation, suPAR levels after 4 weeks of stopping were decreased and no longer significantly different from the never smokers values. SuPAR decreased in both those who received a placebo as well as nicotine patch. Interestingly...

  8. Pulsed radiofrequency of brachial plexus under ultrasound guidance for refractory stump pain: a case report

    Directory of Open Access Journals (Sweden)

    Zheng B

    2017-11-01

    Full Text Available Bixin Zheng, Li Song, Hui Liu Department of Pain Management, West China Hospital of Sichuan University, Chengdu, China Abstract: The post-amputation (pain syndrome, including stump pain, phantom limb sensation, and phantom limb pain is common but difficult to treat. Refractory stump pain in the syndrome is an extremely challenging and troublesome clinical condition. Patients respond poorly to drugs, nerve blocks, and other effective treatments like spinal cord stimulation and surgery. Pulsed radiofrequency (PRF technique has been shown to be effective in reducing neuropathic pain. This report describes a patient with persistent and refractory upper limb stump pain being successfully relieved with PRF of brachial plexus under ultrasound guidance after a 6-month follow-up period, suggesting that PRF may be considered as an alternative treatment for refractory stump-neuroma pain. Keywords: ultrasound guidance, pulsed radiofrequency, brachial plexus, refractory stump pain 

  9. Nonsurgical Transurethral Radiofrequency Collagen Denaturation: Results at Three Years after Treatment

    Directory of Open Access Journals (Sweden)

    Denise M. Elser

    2011-01-01

    Full Text Available Objective. To assess treatment efficacy and quality of life in women with stress urinary incontinence 3 years after treatment with nonsurgical transurethral radiofrequency collagen denaturation. Methods. This prospective study included 139 women with stress urinary incontinence due to bladder outlet hypermobility. Radiofrequency collagen denaturation was performed using local anesthesia in an office setting. Assessments included incontinence quality of life (I-QOL and urogenital distress inventory (UDI-6 instruments. Results. In total, 139 women were enrolled and 136 women were treated (mean age, 47 years. At 36 months, intent-to-treat analysis (n=139 revealed significant improvements in quality of life. Mean I-QOL score improved 17 points from baseline (P=.0004, while mean UDI-6 score improved (decreased 19 points (P=.0005. Conclusions. Transurethral collagen denaturation is a low-risk, office-based procedure that results in durable quality-of-life improvements in a significant proportion of women for as long as 3 years.

  10. INFLUENCE OF CONSTRUCTIVE AND TECHNOLOGICAL DEFECTS ON COAXIAL RADIO-FREQUENCY CABLE IMPEDANCE

    Directory of Open Access Journals (Sweden)

    G.V. Bezprozvannych

    2013-04-01

    Full Text Available Coaxial user's radio-frequency cables belong to a category of cable television network elements parameters of which essentially specify the system capabilities as a whole. The cable working frequency spectrum spreading to 1000 MHz along with digital television and soundtrack signals transmission and high-definition television introduction causes more rigid requirements for wave impedance and, consequently, for the cable design. The established norms on user's cable impedance deviations fail to answer the state-of-the-art requirements for granting a complex of interactive services. On the basis of calculations performed, values of internal and external conductor diameters deviations as well as dielectric permeability of the insulation material are validated. For up-to-date user's radio-frequency cables, the impedance deviation from the normalized average value of 75 Ohm should not exceed ± 2 Ohm.

  11. Estimation of the electrical power needed for LHC magnets and radiofrequency at 7 TeV

    CERN Document Server

    Thiesen, H; Burnet, J P

    2012-01-01

    The purpose of this paper is to provide the electrical power needed from the grid for the power converters feeding the magnets (superconducting, warm and experiments) and the radiofrequency of the LHC. At 4 TeV, the active power required for the magnets is 17.6MW and the estimation is 25.5MW at 7 TeV. The active power needed for the radiofrequency depends on the beam intensity and on the bunch spacing. It will grow from 7MW to 10MW with 25ns bunch spacing operation. This does not include the power needed for the cryogenic and magnet auxiliary systems. This paper gives also the instantaneous profile of the power needed from the grid during the ramp and the reactive power which needs to be compensated by the static VAR compensators.

  12. Radiofrequency identification specimen tracking in anatomical pathology: pilot study of 1067 consecutive prostate biopsies.

    Science.gov (United States)

    Bostwick, David G

    2013-10-01

    Improved methods such as radiofrequency identification (RFID) are needed to optimize specimen tracking in anatomical pathology. We undertook a study of RFID in an effort to optimize specimen tracking and patient identification, including the following: (1) creation of workflow process maps, (2) evaluation of existing RFID hardware technologies, (3) creation of Web-based software to support the RFID-enabled workflow, and (4) assessment of the impact with a series of prostate biopsies. We identified multiple steps in the workflow process in which RFID enhanced specimen tracking. Multiple product choices were found that could withstand the harsh heat and chemical environments encountered in pathology processing, and software that was compatible with our laboratory information system was designed in-house. A total of 1067 prostate biopsies were received, and 78.3% were successfully processed with the RFID system. Radiofrequency identification allowed dynamic specimen tracking throughout the workflow process in anatomical pathology. Copyright © 2013. Published by Elsevier Inc.

  13. Radiofrequency antenna for suppression of parasitic discharges in a helicon plasma thruster experiment

    Science.gov (United States)

    Takahashi, Kazunori

    2012-08-01

    A radiofrequency (rf) antenna for helicon plasma thruster experiments is developed and tested using a permanent magnets helicon plasma source immersed in a vacuum chamber. A magnetic nozzle is provided by permanent magnets arrays and an argon plasma is produced by a 13.56 MHz radiofrequency helicon-wave or inductively-coupled discharge. A parasitic discharge outside the source tube is successfully suppressed by covering the rf antenna with a ceramic ring and a grounded shield; a decrease in the ion saturation current of a Langmuir probe located outside the source tube is observed and the ion saturation current on axis increases simultaneously, compared with the case of a standard uncovered rf antenna. It is also demonstrated that the covered antenna can yield stable operation of the source.

  14. Submucosal resection of a microcystic oropharyngeal lymphatic malformation using radiofrequency ablation.

    Science.gov (United States)

    Thottam, Prasad John; Al-Barazi, Randa; Madgy, David N; Rozzelle, Arlene

    2013-09-01

    Lymphatic malformations (LMs) are uncommon congenital anomalies noted to have a prevalence of 1 per 5000 births and comprise roughly 6% of all pediatric soft tissue lesions. Recently radiofrequency ablation has been described as a surgical option for the treatment microcystic LMs in the oral cavity, more specifically the tongue. The following case describes the use of radiofrequency ablation for the submucosal removal of a large obstructing pharyngeal LM in a 4-year-old female. The mucosal sparing approach and surgical method of extirpation are discussed in detail. To the authors' knowledge this is the first description of a submucosal coblation technique being used as treatment for pharyngeal LMs. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Value of radiofrequency ablation in the management of retropharyngeal lymphatic malformation.

    Science.gov (United States)

    Lisan, Quentin; Villepelet, Aude; Parodi, Marine; Garabedian, Eréa-Noël; Blouin, Marie Julie; Couloigner, Vincent; Leboulanger, Nicolas

    2016-04-01

    Lymphatic malformations are benign malformations frequently occurring in the head and neck. Retropharyngeal location is rare, can be life threating and its management is particularly challenging. Over a three-year period, three patients presented with symptomatic (dyspnea and/or dysphagia) retropharyngeal lymphatic malformation. All were treated using a radiofrequency ablation of lymphatic malformation through a trans-oral approach. No major complications occurred following the surgery. During the follow-up, no recurrence was noted and all patients were asymptomatic. Radiofrequency ablation in the management of retropharyngeal lymphatic malformations is a simple technique with very good results and allows a fast recovery with minimum morbidity and a short hospital stay. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

    Science.gov (United States)

    Balmori, Alfonso

    2015-06-15

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

  17. 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.

  18. CFD Application to Hydrogen Risk Analysis and PAR Qualification

    Directory of Open Access Journals (Sweden)

    Jinbiao Xiong

    2009-01-01

    Full Text Available A three dimensional computation fluid dynamics (CFD code, GASFLOW, is applied to analyze the hydrogen risk for Qinshan-II nuclear power plant (NPP. In this paper, the effect of spray modes on hydrogen risk in the containment during a large break loss of coolant accident (LBLOCA is analyzed by selecting three different spray strategies, that is, without spray, with direct spray and with both direct and recirculation spray. A strong effect of spray modes on hydrogen distribution is observed. However, the efficiency of the passive auto-catalytic recombiners (PAR is not substantially affected by spray modes. The hydrogen risk is significantly increased by the direct spray, while the recirculation spray has minor effect on it. In order to simulate more precisely the processes involved in the PAR operation, a new PAR model is developed using CFD approach. The validation shows that the results obtained by the model agree well with the experimental results.

  19. PARS PLANA VITRECTOMY THROUGH A CUSTOM FLEXIBLE IRIS PROSTHESIS.

    Science.gov (United States)

    Toygar, Okan; Snyder, Michael E; Riemann, Christopher D

    2016-08-01

    To demonstrate the outcomes of pars plana vitrectomy in patients with custom flexible iris prosthesis (CFIP). The medical records of patients who underwent CFIP placement were retrospectively reviewed. Patients who underwent pars plana vitrectomy concurrent with or after placement of CFIP were identified. Preoperative, intraoperative, and postoperative parameters were analyzed. Surgeons were surveyed regarding the technical aspects of the vitreoretinal surgery. Outcome measures included: anatomic success, complications, surgeon-rated ease of visualization through CFIP during pars plana vitrectomy, and Snellen best-corrected visual acuity. Twenty-four surgeries were performed in 20 eyes of 20 patients. Postoperative best-corrected visual acuity improved in 11 eyes (55%), remained unchanged in 5 eyes (25%), and declined in 4 eyes (20%) after a mean follow-up of 16.1 ± 16.\

  20. Protease activated receptor-2 (PAR2): possible target of phytochemicals.

    Science.gov (United States)

    Kakarala, Kavita Kumari; Jamil, Kaiser

    2015-09-01

    The use of phytochemicals either singly or in combination with other anticancer drugs comes with an advantage of less toxicity and minimal side effects. Signaling pathways play central role in cell cycle, cell growth, metabolism, etc. Thus, the identification of phytochemicals with promising antagonistic effect on the receptor/s playing key role in single transduction may have better therapeutic application. With this background, phytochemicals were screened against protease-activated receptor 2 (PAR2). PAR2 belongs to the superfamily of GPCRs and is an important target for breast cancer. Using in silico methods, this study was able to identify the phytochemicals with promising binding affinity suggesting their therapeutic potential in the treatment of breast cancer. The findings from this study acquires importance as the information on the possible agonists and antagonists of PAR2 is limited due its unique mechanism of activation.

  1. 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.

  2. Percutaneous radiofrequency ablation of liver cancer in the hepatic dome using the intrapleural fluid infusion technique.

    Science.gov (United States)

    Kondo, Y; Yoshida, H; Tateishi, R; Shiina, S; Kawabe, T; Omata, M

    2008-08-01

    Intrapleural fluid infusion improves ultrasonographic visualization of tumours in the hepatic dome. The aim of this study was to assess the safety and long-term efficacy of ultrasonographically guided percutaneous radiofrequency ablation for tumours in the hepatic dome with intrapleural infusion. Of 2575 patients with hepatocellular carcinoma or hepatic metastases treated with radiofrequency ablation, intrapleural fluid infusion was performed in 587 patients for tumours in the hepatic dome. After the tip of a 14-G metallic needle was positioned in the pleural cavity under ultrasonographic guidance, 500-1000 ml of 5 per cent glucose solution was infused in 5-15 min. Radiofrequency ablation was performed using an internally cooled electrode. Long-term results were evaluated in 347 patients with a single hepatocellular carcinoma who were naive to any treatment. Intrapleural fluid infusion was successfully performed in all 587 patients. The major complication rate on a per tumour basis was similar for patients treated with and without intrapleural infusion (1.6 versus 1.6 per cent; P = 0.924). The overall and recurrence-free survival were both similar for naive patients with a single hepatocellular carcinoma treated with and without intrapleural infusion (P = 0.429 and P = 0.109 respectively). Intrapleural infusion was not associated with lower overall survival in multivariable analysis. With intrapleural fluid infusion, radiofrequency ablation for tumours in the hepatic dome was safe and effective, resulting in satisfactory overall and recurrence-free survival. Copyright (c) 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

  3. 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.

  4. Exposure to radiofrequency electromagnetic fields and sleep quality : a prospective cohort study

    OpenAIRE

    Evelyn Mohler; Patrizia Frei; Jürg Fröhlich; Charlotte Braun-Fahrländer; Martin Röösli

    2012-01-01

    BACKGROUND: There is persistent public concern about sleep disturbances due to radiofrequency electromagnetic field (RF-EMF) exposure. The aim of this prospective cohort study was to investigate whether sleep quality is affected by mobile phone use or by other RF-EMF sources in the everyday environment. METHODS: We conducted a prospective cohort study with 955 study participants aged between 30 and 60 years. Sleep quality and daytime sleepiness was assessed by means of standardized questionna...

  5. First experience using navigation-guided radiofrequency kyphoplasty for sacroplasty in sacral insufficiency fractures

    Energy Technology Data Exchange (ETDEWEB)

    Klingler, J.H.; Kluge, P.; Sircar, R.; Kogias, E.; Scholz, C.; Krueger, M.T.; Scheiwe, C.; Hubbe, U. [Freiburg Univ. Medical Center, Freiburg (Germany). Dept. of Neurosurgery

    2013-08-15

    Purpose: To evaluate the efficacy and safety of navigation-guided radiofrequency kyphoplasty for sacroplasty in patients with sacral insufficiency fractures. Methods: In this single-center retrospective observational study, four consecutive patients with sacral insufficiency fractures were treated with navigation-guided radiofrequency kyphoplasty for sacroplasty between April 2010 and May 2012. Symptom characteristics, pain duration and pain intensity were recorded for each patient. Cement extravasation was evaluated in thin-sliced and triplanar reconstructed CT scans of the sacrum. Results: Four female patients with painful sacral insufficiency fractures and extensive osteopenic areas significantly improved from an average pre-treatment VAS score of 8.3 {+-} 0.5 to 2.3 {+-} 1.0 (p < 0.001) on the first postoperative day and to 1.3 {+-} 1.9 (p < 0.004) at follow-up (mean, 20.1 weeks). Slight cement extravasations were observed without evidence of being symptomatic. No major complications or procedure-related morbidity were noted. Conclusion: From the limited experience in four patients, navigation-guided radiofrequency kyphoplasty appears to be a safe and effective treatment option for sacral insufficiency fractures even though asymptomatic cement extravasation was noted. The use of navigation based on intraoperative 3 D images simplifies the positioning of the navigated bone needles via the long axis approach. The radiofrequency kyphoplasty system provides the possibility to administer a sufficient amount of bone cement with a well-defined viscosity over the entire period of the procedure leading to high security and low cement extravasation. Sacroplasty provides rapid and enduring pain relief and facilitates prompt mobilization. (orig.)

  6. Right atrial mass following transcatheter radiofrequency ablation for recurrent atrial fibrillation: thrombus, endocarditis or mixoma?

    Science.gov (United States)

    Ancona, Roberta; Comenale Pinto, Salvatore; Caso, Pio; Di Palma, Vito; Pisacane, Francesca; Martiniello, Alfonso Roberto; Quarto, Cesare; De Rosa, Nicla; Pisacane, Carlo; Calabrò, Raffaele

    2009-03-01

    We report a case of an asymptomatic patient in whom a right atrial mass was fortuitously documented by echocardiography few months after a transcatheter radiofrequency catheter ablation for recurrent AF. No masses were seen in the cardiac chambers before the ablative procedure, raising important diagnostic and decision-making issues. The patient was referred to the surgeon and a diagnosis of right atrial myxoma was made.

  7. Radio-frequency properties of stacked long Josephson junctions with nonuniform bias current distribution

    DEFF Research Database (Denmark)

    Filatrella, G; Pedersen, Niels Falsig

    1999-01-01

    We have numerically investigated the behavior of stacks of long Josephson junctions considering a nonuniform bias profile. In the presence of a microwave field the nonuniform bias, which favors the formation of fluxons, can give rise to a change of the sequence of radio-frequency induced steps....... The amplitude of the steps is enhanced when the external frequency matches the fluxon shuttling regime. ©1999 American Institute of Physics....

  8. Retrograde Transpubic Approach for Percutaneous Radiofrequency Ablation and Cementoplasty of Acetabular Metastasis

    Directory of Open Access Journals (Sweden)

    Salem Bauones

    2015-01-01

    Full Text Available We report a case of painful and disabling anterior acetabular bone metastasis treated with bipolar radiofrequency ablation and cementoplasty. Due to the high risk of complications related to the proximity of the femoral neurovascular structures with a direct approach, we successfully performed a retrograde transpubic approach under combined CT and fluoroscopic guidance. In the present report, we describe this approach detailing its indications, advantages, and the technical tips to achieve a safe and satisfactory procedure.

  9. Electrophysiological Studies and Radiofrequency Ablations in Children and Adolescents with Arrhythmia

    Science.gov (United States)

    Simão, Mariana Fernandez; Rios, Matheus Nardi; Leiria, Tiago Luiz Luz; Kruse, Marcelo Lapa; Pires, Leonardo Martins; SantAnna, Roberto Tofani; de Lima, Gustavo Glotz

    2015-01-01

    Background Radiofrequency ablation is the standard non-pharmacological treatment for arrhythmias in pediatric patients. However, arrhythmias and their associated causes have particular features in this population. Objective To analyze the epidemiological characteristics and findings of electrophysiological diagnostic studies and radiofrequency ablations in pediatric patients referred to the Electrophysiology Unit at Instituto de Cardiologia do Rio Grande do Sul, in order to characterize the particularities of this population. Methods Cross-sectional study with 330 electrophysiological procedures performed in patients aged less than 20 years between June 1997 and August 2013. Results In total, 330 procedures (9.6% of the overall procedures) were performed in patients aged less than 20 years (14.33 ± 3.25 years, age range 3 months to 19 years), 201 of which were males (60.9%). A total of 108 (32.7%) electrophysiological diagnostic studies were performed and of these, 48.1% showed abnormal findings. Overall, 219 radiofrequency ablations were performed (66.3%) with a success rate of 84.8%. The presence of an accessory pathway was the most prevalent finding, occurring in 158 cases (72.1%), followed by atrioventricular nodal reentrant tachycardia (16.8%), typical atrial flutter (3.1%) and extrasystoles originating from the right ventricular outflow tract (2.7%). Three patients developed complications during ablation (1.4%). Among congenital heart diseases, which occurred in 51 (15.4%) patients, atrial sept defect was the most frequent (27.4%), followed by ventricular sept defect (25.4%) and Ebstein's anomaly (17.6%). Conclusion Electrophysiological study and radiofrequency ablation are effective tools for diagnosis and treatment of arrhythmias in the pediatric population. PMID:25372472

  10. Effectiveness of Radiofrequency Hyperthermia for Treating Cartilage in Guinea Pigs with Primary Osteoarthritis.

    Science.gov (United States)

    Takahashi, Kenji; Nakamura, Hiroshi; Ozawa, Hitoshi; Hashimoto, Sanshiro; Iijima, Norio; Higo, Shimpei; Watanabe, Hiroshi; Mochizuki, Yusuke; Takai, Shinro

    2018-01-01

    Objective Autophagy was reported to be essential for maintaining chondrocyte function, and reduced autophagy leads to osteoarthritis (OA). Previous studies showed involvement of heat shock stress in the control of autophagy in cells. This study sought to investigate the effect of hyperthermia on the expression of autophagy-related proteins in articular cartilage and the progression of naturally occurring OA in Hartley guinea pigs. Design Radiofrequency pulses of 13.56 MHz were applied to the animals' knees for 20 minutes to induce hyperthermia. The knee joints were resected at 8 hours, 24 hours, 72 hours, 7 days, and 6 months after hyperthermia. Serial sections of knees were examined for histopathological changes. The expression levels of Unc-51-like kinase 1 (ULK1) and Beclin1 were analyzed by immunohistochemistry. Results Analysis of the distribution of positive cells showed that, in cases of moderate OA, ULK1 and Beclin1 expression levels were significantly decreased in the superficial zone (SZ) and middle zone (MZ) ( P < 0.01) compared with normal cartilage. Seven days after exposure to radiofrequency waves, expression levels of ULK1 and Beclin1 were augmented in the SZ in animals with mild OA. The severity of cartilage degradation was significantly reduced ( P < 0.01) in the radiofrequency-treated knees versus the untreated knees. Conclusions This study showed that heat stimulation enhanced autophagy in healthy knee chondrocytes and chondrocytes in knees with mild OA. The study also showed that long-term periodic application of hyperthermia suppresses aging-related progression of OA. The activation of autophagy by radiofrequency hyperthermia may be an effective therapeutic approach for osteoarthritis.

  11. Noise performance of the radio-frequency single-electron transistor

    OpenAIRE

    Roschier, Leif; Hakonen, Pertti J.; Bladh, K.; Delsing, P.; Lehnert, K. W.; Spietz, Lafe; Schoelkopf, Rob

    2004-01-01

    We have analyzed a radio-frequency single-electron-transistor (RF-SET) circuit that includes a high-electron-mobility-transistor (HEMT)amplifier, coupled to the single-electron-transistor (SET) via an impedance transformer. We consider how power is transferred between different components of the circuit, model noise components, and analyze the operating conditions of practical importance. The results are compared with experimental data on SETs. Good agreement is obtained between our noise mod...

  12. Does Exposure to a Radiofrequency Electromagnetic Field Modify Thermal Preference in Juvenile Rats?

    OpenAIRE

    Amandine Pelletier; Stéphane Delanaud; René de Seze; Véronique Bach; Jean-Pierre Libert; Nathalie Loos

    2014-01-01

    Some studies have shown that people living near a mobile phone base station may report sleep disturbances and discomfort. Using a rat model, we have previously shown that chronic exposure to a low-intensity radiofrequency electromagnetic field (RF-EMF) was associated with paradoxical sleep (PS) fragmentation and greater vasomotor tone in the tail. Here, we sought to establish whether sleep disturbances might result from the disturbance of thermoregulatory processes by a RF-EMF. We recorded th...

  13. Adiabatic radio-frequency potentials for the coherent manipulation of matter waves

    DEFF Research Database (Denmark)

    Lesanovsky, Igor; Schumm, Thorsten; Hofferberth, S.

    2006-01-01

    Adiabatic dressed state potentials are created when magnetic substates of trapped atoms are coupled by a radio-frequency field. We discuss their theoretical foundations and point out fundamental advantages over potentials purely based on static fields. The enhanced flexibility enables one...... to implement numerous configurations, including double wells, Mach-Zehnder, and Sagnac interferometers which even allows for internal state-dependent atom manipulation. These can be realized using simple and highly integrated wire geometries on atom chips....

  14. Low-Power Radio-Frequency SiGe Analog-to-Digital Converter

    Science.gov (United States)

    Thompson, Willie L, II; Hall, Wesley G.; Piepmeier, Jeffrey R.; Johnson-Bey, Charles T.

    2003-01-01

    A low-power, radio-frequency analog-to-digital converter (RF-ADC) for soil moisture remote sensing was designed and fabricated. The RF-ADC is the fundamental component used in a direct-sampling digital radiometer, which is proposed to minimize the power dissipation and system complexity for synthetic thinned array radiometer. The circuit was implemented using 0.8 micron 35-GHz silicon germanium BiCMOS technology. The total power dissipation was 222 mW.

  15. New horizons in MR-controlled and monitored radiofrequency ablation of liver tumours

    OpenAIRE

    Cernicanu, Alexandru; Lepetit-Coiff?, Matthieu; Viallon, Magalie; Terraz, Sylvain; Becker, Christoph D.

    2007-01-01

    Abstract There is a sustained interest in using magnetic resonance (MR) thermometry to monitor the radiofrequency ablation of liver tumours as a means of visualizing the progress of the thermal coagulation and deciding the optimal end-point. Despite numerous technical challenges, important progress has been made and demonstrated in animal studies. In addition to MR thermometry, MR can now be used for the guidance of the tumour targeting with ?fluoroscopic? rapid image acquisition, and it can ...

  16. Percutaneous osteoid osteoma treatment with combination of radiofrequency and alcohol ablation

    Energy Technology Data Exchange (ETDEWEB)

    Akhlaghpoor, S. [Noor Medical Imaging Center, Tehran (Iran, Islamic Republic of)]. E-mail: akhlaghpoor@nmri-ir.com; Tomasian, A. [Noor Medical Imaging Center, Tehran (Iran, Islamic Republic of); Arjmand Shabestari, A. [Noor Medical Imaging Center, Tehran (Iran, Islamic Republic of); Ebrahimi, M. [Noor Medical Imaging Center, Tehran (Iran, Islamic Republic of); Alinaghizadeh, M.R. [Noor Medical Imaging Center, Tehran (Iran, Islamic Republic of)

    2007-03-15

    Aim: To assess the efficacy of percutaneous osteoid osteoma treatment using a combination of radiofrequency ablation (RFA) and alcohol ablation with regard to technical and long-term clinical success. Materials and methods: From December 2001 to November 2004, RFA and subsequent alcohol ablation was performed on 54 patients with osteoid osteoma, diagnosed clinically using radiography, computed tomography (CT) and symptoms. Under general anaesthesia, treatment was performed via percutaneous access under thin section (2 mm) spiral CT guidance in all cases with an 11 G radiofrequency-compatible coaxial needle and 2 mm coaxial drill system and 1.0 cm active tip 17 G non-cooled radiofrequency needle. RFA was performed at 90 {sup o}C for a period of 6 min. After needle removal, 0.5-1.0 ml absolute alcohol (99.8% concentration) was injected directly into the nidus using a 20 G needle. Patients were discharged within 24 h and followed up clinically (at 1 week, 1 month and every 3 months thereafter). Results: The technical success rate was 100%. Complications occurred in two patients consisting of local mild cellulitis in entry site and peripheral small zone paresthesia on the anterior part of leg. The follow-up period range was 13-48 months (mean {+-} SD, 28.2 {+-} 7.4 months). Prompt pain relief and return to normal activities were observed in 52 of 54 patients. Recurrent pain occurred in two patients after a 1 and 3 months period of being pain free, respectively; a second RFA and alcohol ablation was performed achieving successful results. Primary and secondary clinical success rates were 96.3% (52/54 patients) and 100% (2/2 patients), respectively. Conclusion: Percutaneous osteoid osteoma treatment with combination of radiofrequency and alcohol ablation is safe, effective and minimally invasive with high primary and secondary success rates. Persistent or recurrent lesions can be effectively re-treated.

  17. Biliary peritonitis after radiofrequency ablation diagnosed by gadoxetic acid-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Akihiro; Isoda, Hiroyoshi; Togashi, Kaori [Dept. of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto (Japan); Koyama, Takashi; Todo, Giro; Osaki, Yukio [Osaka Red Cross Hospital, Osaka (Japan)

    2013-12-15

    This study describes the first case of biliary peritonitis after radiofrequency ablation diagnosed by magnetic resonance (MR) imaging with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA), a hepatocyte-specific MR imaging contrast agent. The image acquired 300 minutes after the administration of Gd-EOB-DTPA was useful to make a definite diagnosis and to identify the pathway of bile leakage. It is important to decide on the acquisition timing with consideration of the predicted location of bile duct injury.

  18. Treatment of Osteoid Osteomas Using a Navigational Bipolar Radiofrequency Ablation System

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Adam N., E-mail: wallacea@mir.wustl.edu; Tomasian, Anderanik, E-mail: tomasiana@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States); Chang, Randy O., E-mail: changr@wusm.wustl.edu [Washington University School of Medicine (United States); Jennings, Jack W., E-mail: jenningsj@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States)

    2016-05-15

    BackgroundPercutaneous CT-guided radiofrequency ablation is a safe and effective minimally invasive treatment for osteoid osteomas. This technical case series describes the use of a recently introduced ablation system with a probe that can be curved in multiple directions, embedded thermocouples for real-time monitoring of the ablation volume, and a bipolar design that obviates the need for a grounding pad.MethodsMedical records of all patients who underwent radiofrequency ablation of an osteoid osteoma with the STAR Tumor Ablation System (DFINE; San Jose, CA) were reviewed. The location of each osteoid osteoma, nidus volume, and procedural details were recorded. Treatment efficacy and long-term complications were assessed at clinical follow-up.ResultsDuring the study period, 18 osteoid osteomas were radiofrequency ablated with the multidirectional bipolar system. Lesion locations included the femur (50 %; 9/18), tibia (22 %; 4/18), cervical spine (11 %; 2/18), calcaneus (5.5 %; 1/18), iliac bone (5.5 %; 1/18), and fibula (5.5 %; 1/18). The median nidus volume of these cases was 0.33 mL (range 0.12–2.0 mL). All tumors were accessed via a single osseous channel. Median cumulative ablation time was 5 min and 0 s (range 1 min and 32 s–8 min and 50 s). All patients with clinical follow-up reported complete symptom resolution. No complications occurred.ConclusionSafe and effective CT-guided radiofrequency ablation of osteoid osteomas can be performed in a variety of locations using a multidirectional bipolar system.

  19. Radiofrequency ablation of a cervical osteoid osteoma: a trans-thyroid approach

    Energy Technology Data Exchange (ETDEWEB)

    Sutphen, Sean A.; Murakami, James W. [Columbus Children' s Hospital, Children' s Radiological Institute, Columbus, OH (United States)

    2007-01-15

    We present a 16-year-old girl with an osteoid osteoma in the vertebral body of C5. Given the difficulty of surgically treating the lesion, radiofrequency ablation was used. Percutaneous needle access to this lesion in the anterior aspect of the cervical vertebral body was limited by the many critical adjacent structures. We present our successful treatment of this lesion utilizing a transthyroid needle approach. (orig.)

  20. La projection par plasma : une revue

    Science.gov (United States)

    Fauchais, P.; Grimaud, A.; Vardelle, A.; Vardelle, M.

    are presented in the fields of aeronautics and mechanics. La qualité d'un dépôt projete par plasma dépend de nombreux paramètres que l'on commence à mieux appréhender du fait des progrès de la modélisation et de la métrologie tant des écoulements plasmas que des transferts plasma-particules ou que des conditions d'écrasement et de refroidissement des particules lors de leur impact sur le substrat ou les couches déjà déposées. Les techniques de mesure utilisdes et leurs limitations sont d'abord rappelées tant pour les jets de plasma que pour les particules en vol et l'importance des différents phénomènes intervenant dans les transferts plasma-particules est soulignée : gradients de température et de concentration d'espèces chimiques très élevés autour des particules, effets de propagation de la chaleur, notamment pour les particules céramiques, effet d'évaporation, effet de raréfaction sensible dès la pression atmosphérique. Les problèmes de distribution de taille et de vitesse d'injection des particules sont également abordés car ils conditionnent les distributions de trajectoires et donc le traitement des particules dans le jet de plasma. La génération du plasma montre d'une part 1'influence considérable de l'injection du gaz, de sa nature, du dessin de la chambre d'arc et de la tuyère ainsi que du pompage de l'air ambiant sur la longueur des jets de plasma d'arc et d'autre part les problèmes d'injection pour éviter le couplage avec la décharge dans les jets de plasmas R.E Tout ceci est illustré avec des exemples de dépôt d'alumine, de zircone, de cermet carbure et de nickel. L'écrasement des particules est ensuite abordé avec les problèmes de réactions chimiques, de trempe ultra-rapide et donc de structure cristalline des dépôts, d'adhdsion mais aussi de containtes résiduelles et de leur contrôle via les gradients de température dans les dépôts pendant le tir. Enfin quelques applications actuelles sont pr

  1. Contributions of Protease-Activated Receptors PAR1 and PAR4 to Thrombin-Induced GPIIbIIIa Activation in Human Platelets.

    Science.gov (United States)

    Duvernay, Matthew T; Temple, Kayla J; Maeng, Jae G; Blobaum, Anna L; Stauffer, Shaun R; Lindsley, Craig W; Hamm, Heidi E

    2017-01-01

    Human platelets display a unique dual receptor system for responding to its primary endogenous activator, α-thrombin. Because of the lack of efficacious antagonists, the field has relied on synthetic peptides and pepducins to describe protease-activated receptor PAR1 and PAR4 signaling. The precise contributions of each receptor have not been established in the context of thrombin. We took advantage of newly discovered PAR antagonists to contrast the contribution of PAR1 and PAR4 to thrombin-mediated activation of the platelet fibrin receptor (GPIIbIIIa). PAR1 is required for platelet activation at low but not high concentrations of thrombin, and maximal platelet activation at high concentrations of thrombin requires PAR4. As the concentration of thrombin is increased, PAR1 signaling is quickly overcome by PAR4 signaling, leaving a narrow window of low thrombin concentrations that exclusively engage PAR1. PAR4 antagonism reduces the maximum thrombin response by over 50%. Thus, although the PAR1 response still active at higher concentrations of thrombin, this response is superseded by PAR4. Truncation of a known PAR4 antagonist and identification of the minimum pharmacophore converted the mechanism of inhibition from noncompetitive to competitive, such that the antagonist could be outcompeted by increasing doses of the ligand. Fragments retained efficacy against both soluble and tethered ligands with lower cLogP values and an increased free fraction in plasma. These reversible, competitive compounds represent a route toward potentially safer PAR4 antagonists for clinical utility and the development of tools such as radioligands and positron emission tomography tracers that are not currently available to the field for this target. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  2. Radiofrequency therapy in back pain and complex regional pain syndrome (CRPS

    Directory of Open Access Journals (Sweden)

    Norina Bergamin

    2011-01-01

    Full Text Available Percutaneous radiofrequency procedures are frequently used in the management of chronic pain. Continuous radiofrequency (CRF has been established as a safe and effective treatment for pain originating from facet and sacroiliac joints by way of co-agulation of their nerve supply. Different methods have been proposed to account for the complex nerve supply of the sacroiliac joint. Due to its neurodestructive property, CRF was limited to the treatment of neuropathic pain. When applied to the dorsal root ganglion (DRG for spinal pain or to the sympathetic ganglia in treatment of CRPS, heat related side effects have been reported. With the development of pulsed radiofrequency (PRF, a less destructive alternative to CRF became available, that is more suitable to treat neuropathic pain. PRF was adopted in the treatment of several pain conditions with different success. The results with PRF adjacent to the DRG are promising, whereas for facet and sacroiliac joint pain PRF could not yet be proven equally effective as CRF. As for PRF in CRPS there is almost no evidence available. The potential of PRF seems to lie in those areas where CRF is of limited value. Con-versely, it is questionable if PRF will ever be equally effective in indications, where CRF is already well established. Despite its active use in clinical practice, PRF is not validated yet nor is its mode of action. The literature in both cases is accumulating but further studies are urgently needed.

  3. Mathematical 3D modelling and sensitivity analysis of multipolar radiofrequency ablation in the spine.

    Science.gov (United States)

    Matschek, Janine; Bullinger, Eric; von Haeseler, Friedrich; Skalej, Martin; Findeisen, Rolf

    2017-02-01

    Radiofrequency ablation is a valuable tool in the treatment of many diseases, especially cancer. However, controlled heating up to apoptosis of the desired target tissue in complex situations, e.g. in the spine, is challenging and requires experienced interventionalists. For such challenging situations a mathematical model of radiofrequency ablation allows to understand, improve and optimise the outcome of the medical therapy. The main contribution of this work is the derivation of a tailored, yet expandable mathematical model, for the simulation, analysis, planning and control of radiofrequency ablation in complex situations. The dynamic model consists of partial differential equations that describe the potential and temperature distribution during intervention. To account for multipolar operation, time-dependent boundary conditions are introduced. Spatially distributed parameters, like tissue conductivity and blood perfusion, allow to describe the complex 3D environment representing diverse involved tissue types in the spine. To identify the key parameters affecting the prediction quality of the model, the influence of the parameters on the temperature distribution is investigated via a sensitivity analysis. Simulations underpin the quality of the derived model and the analysis approach. The proposed modelling and analysis schemes set the basis for intervention planning, state- and parameter estimation, and control. Copyright © 2016. Published by Elsevier Inc.

  4. Comparison of power- and temperature-guided radiofrequency modification of the atrioventricular node. Polaris Investigator Group.

    Science.gov (United States)

    Kavesh, N G; Gosnell, M R; Shorofsky, S R; Gold, M R

    1997-12-01

    The purpose of this study was to compare the performance and clinical outcome of radiofrequency ablation of the substrate of atrioventricular (AV) nodal reentrant tachycardia (AVNRT) when guided by power output or temperature monitoring. Two sequential multicenter studies of power-controlled and open-loop, temperature-controlled radiofrequency ablation were analyzed in 171 patients undergoing AV node modification for the treatment of AVNRT. After successful ablation of AVNRT, complete elimination of slow AV node pathway function was accomplished more often with than without temperature monitoring (92% vs 69%, p = 0.005). Greater power was delivered to each patient with than without temperature monitoring (median 47 W, range 10 to 57, vs median 35 W, range 5 to 68, p = 0.001). Acute elimination of tachycardia (100% vs 96%), 3-month recurrence (6% vs 8%), procedural times (162 vs 170 minutes), fluoroscopy times (24.6 vs 29.5 minutes), complications (6% vs 3%), and catheter removals to check for coagulum (8% vs 6%) did not differ between patients treated with and without temperature monitoring, respectively. Power- and temperature-controlled radiofrequency techniques are highly successful with low complication rates for slow pathway ablation. Temperature monitoring may allow the safe delivery of more power, and the more complete elimination of slow AV node pathway function.

  5. [Surgical treatment of chronic non-insertional Achilles tendinopathy in runners using bipolar radiofrequency].

    Science.gov (United States)

    Arnal-Burró, J; López-Capapé, D; Igualada-Blázquez, C; Ortiz-Espada, A; Martín-García, A

    2016-01-01

    To present the surgical technique with release of peritendon and radiofrequency as an effective treatment for athletes with chronic tendinopathy of the Achilles tendon body. This is a retrospective case series descriptive type study. The series consists of 17 Achilles tendon surgeries in 13 patients, who habitually run. The study included patients with non-insertional Achilles tendinopathy refractory to conservative treatments. After a minimum follow-up of 12 months, clinical improvement of the athletes was assessed using the Nirschl pain scale, as well as athletic performance. An improvement was obtained in 94% of symptoms and a return to the previous performance in of 70% of cases in the 12 months follow-up. Peritendon release combined with bipolar radiofrequency is presented as an effective solution in this condition, for which there is currently no consensus on the best treatment. In patients in whom, after an appropriate conservative treatment for a sufficient period (at least 6 months) the non-insertional Achilles tendinopathy persists, open adhesiolysis combined with bipolar radiofrequency is a safe and with a high success rate clinical and functional intervention. In high performance athletes this technique allows a return to previous activity in a high percentage of cases. Copyright © 2015 SECOT. Published by Elsevier Espana. All rights reserved.

  6. [Radiofrequency kyphoplasty combined with posterior fixation in the treatment of burst fractures].

    Science.gov (United States)

    Jansen, T; Bornemann, R; Otten, L A; Kabir, K; Wirtz, D; Sander, K; Pflugmacher, R

    2013-12-01

    Radiofrequency kyphoplasty is an advancement of the balloon kyphoplasty and offers comparable results with a shorter operation time and a lower risk of cement leakage. This prospective study investigates the outcome of radiofrequency kyphoplasty in combination with posterior fixation by a cement-augmented screw system. Accordingly, statistical analyses of the treatment data were performed. 19 patients (mean age: 74.5 ± 7.2 years) with osteoporotic vertebral burst fractures were included in the study. All of them required a surgical intervention for treating the fracture. Thereby, the vertebrae were augmented by radiofrequency kyphoplasty and a posterior fixation by cement-augmentable screws was performed. To evaluate the effectiveness and safety of the procedure, pain was measured with the visual analog scale (VAS) and functional impairment was analysed by measuring the Oswestry disability index (ODI). Furthermore, a radiographic analysis of the anterior and medial height of the vertebrae and the degree of kyphosis were undertaken. All data were recorded preoperatively, 3 to 4 days postoperatively, 3 months postoperatively and 6 months postoperatively and any additionally occurring cement leakage was documented. The treatment showed a significant reduction of pain and improvement of the functional impairment at the 3 to 4 days postoperative evaluation (pVAS kyphoplasty is a safe and effective procedure for the treatment of vertebral compression fractures in combination with the use of posterior fixation by cement-augmentable screws with an acceptable rate of cement leakage. Georg Thieme Verlag KG Stuttgart · New York.

  7. Tunable Photonic Radiofrequency Filter with A Record High Out-Of-Band Rejection

    CERN Document Server

    Li, Peixuan; Pan, Wei; Yan, Lianshan; Pan, Shilong

    2016-01-01

    As radiofrequency filtering plays a vital role in electromagnetic devices and systems, recently photonic techniques have been intensively studied to implement radiofrequency filters to harness wide frequency coverage, large instantaneous bandwidth, low frequency-dependent loss, flexible tunability and strong immunity to electromagnetic interference. However, one crucial challenge facing the photonic radiofrequency filter (PRF) is the less impressive out-of-band rejection, normally less than 70 dB (see Table I). Here, to the best of our knowledge, we demonstrate a tunable PRF with a record out-of-band rejection of 80 dB, which is one order of magnitude higher than the maximum value (~70 dB) reported so far, when incorporating highly selective polarization control and large narrow-band amplification enabled by stimulated Brillouin scattering effect. Tunable central frequency ranging from 2.1 to 6.1 GHz is also demonstrated. Moreover, the proposed PRF is an active one capable of providing negligible insertion lo...

  8. Use of a novel combined radiofrequency and ultrasound device for lipolysis, skin tightening and cellulite treatment.

    Science.gov (United States)

    Kapoor, Rinky; Shome, Debraj; Ranjan, Anima

    2017-10-01

    Skin laxity and excessive subcutaneous fat are growing cosmetic concerns. The objective of this study is to evaluate the efficacy and safety of a novel radiofrequency and ultrasound workstation for lipolysis, circumference reduction, treatment of skin laxity and cellulite. Two hundred seventy-five (235 women and 40 men) patients were enrolled into the study. Each patient received 3 treatment sessions, each session comprising Ultrasound and Radiofrequency treatments, at two-week intervals. Some received treatment for the abdomen, some for the thighs and some for both. Efficacy was assessed accordingly by measuring changes in abdominal circumference, thigh circumference and appearance of cellulite. Any adverse effect was noted. Paired t-test between measurements at baseline and 4 weeks after 3rd session was significant amongst all the groups, showing that most patients showed improvement in abdominal and/or thigh circumferences. No significant adverse effects were noted during or after the treatment. A combination of alternating hot and cold module Ultrasound and Radiofrequency technologies is a safe and effective modality for lipolysis and to treat skin laxity and cellulite.

  9. Aneuploidy studies in human cells exposed in vitro to GSM-900 MHz radiofrequency radiation using FISH.

    Science.gov (United States)

    Bourthoumieu, Sylvie; Terro, Faraj; Leveque, Philippe; Collin, Alice; Joubert, Vanessa; Yardin, Catherine

    2011-04-01

    Since previous research found an increase in the rate of aneuploidies in human lymphocytes exposed to radiofrequencies, it seems important to perform further studies. The objective of this study was then to investigate whether the exposure to RF (radiofrequency) radiation similar to that emitted by mobile phones of a second generation standard, i.e., Global System for Mobile communication (GSM) may induce aneuploidy in cultured human cells. The potential induction of genomic instability by GSM-900 MHz radiofrequency (GSM-900) was investigated after in vitro exposure of human amniotic cells for 24 h to average-specific absorption rates (SAR) of 0.25, 1, 2 and 4 W/kg in the temperature range of 36.3-39.7°C. The exposures were carried out in a wire-patch cell (WPC). The rate of aneuploidy of chromosomes 11 and 17 was determined by interphase FISH (Fluorescence In Situ Hybridisation) immediately after independent exposure of three different donors for 24 h. At least 100 interphase cells were analysed per assay. No significant change in the rate of aneuploidy of chromosomes 11 and 17 was found following exposure to GSM-900 for 24 h at average SAR up to 4 W/kg. Our study did not show any in vitro aneuploidogenic effect of GSM using FISH and is not in agreement with the results of previous research.

  10. Percutaneous Intraductal Radiofrequency Ablation is a Safe Treatment for Malignant Biliary Obstruction: Feasibility and Early Results

    Energy Technology Data Exchange (ETDEWEB)

    Mizandari, Malkhaz [Tbilisi State Medical University, Department of Radiology (Georgia); Pai, Madhava, E-mail: madhava.pai@imperial.ac.uk; Xi Feng [Imperial College, London, Hammersmith Hospital Campus, Department of Surgery (United Kingdom); Valek, Vlastimil; Tomas, Andrasina [University Hospital Brno Bohunice, Department of Radiology (Czech Republic); Quaretti, Pietro [IRCCS Policlinico San Matteo, Department of Radiology (Italy); Golfieri, Rita; Mosconi, Cristina [University of Bologna, Department of Radiology, Policlinico S. Orsola-Malpighi (Italy); Ao Guokun [The 309 Hospital of Chinese PLA, Department of Radiology (China); Kyriakides, Charis [Imperial College, London, Hammersmith Hospital Campus, Department of Surgery (United Kingdom); Dickinson, Robert [Imperial College London, Department of Bioengineering (United Kingdom); Nicholls, Joanna; Habib, Nagy, E-mail: nagy.habib@imperial.ac.uk [Imperial College, London, Hammersmith Hospital Campus, Department of Surgery (United Kingdom)

    2013-06-15

    Purpose. Previous clinical studies have shown the safety and efficacy of this novel radiofrequency ablation catheter when used for endoscopic palliative procedures. We report a retrospective study with the results of first in man percutaneous intraductal radiofrequency ablation in patients with malignant biliary obstruction. Methods. Thirty-nine patients with inoperable malignant biliary obstruction were included. These patients underwent intraductal biliary radiofrequency ablation of their malignant biliary strictures following external biliary decompression with an internal-external biliary drainage. Following ablation, they had a metal stent inserted. Results. Following this intervention, there were no 30-day mortality, hemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the 39 patients, 28 are alive and 10 patients are dead with a median survival of 89.5 (range 14-260) days and median stent patency of 84.5 (range 14-260) days. One patient was lost to follow-up. All but one patient had their stent patent at the time of last follow-up or death. One patient with stent blockage at 42 days postprocedure underwent percutaneous transhepatic drain insertion and restenting. Among the patients who are alive (n = 28) the median stent patency was 92 (range 14-260) days, whereas the patients who died (n = 10) had a median stent patency of 62.5 (range 38-210) days. Conclusions. In this group of patients, it appears that this new approach is feasible and safe. Efficacy remains to be proven in future, randomized, prospective studies.

  11. Sacroiliac joint pain: Prospective, randomised, experimental and comparative study of thermal radiofrequency with sacroiliac joint block.

    Science.gov (United States)

    Cánovas Martínez, L; Orduña Valls, J; Paramés Mosquera, E; Lamelas Rodríguez, L; Rojas Gil, S; Domínguez García, M

    2016-05-01

    To compare the analgesic effects between the blockade and bipolar thermal radiofrequency in the treatment of sacroiliac joint pain. Prospective, randomised and experimental study conducted on 60 patients selected in the two hospitals over a period of nine months, who had intense sacroiliac joint pain (Visual Analogue Scale [VAS]>6) that lasted more than 3 months. Patients were randomised into three groups (n=20): Group A (two intra-articular sacroiliac injections of local anaesthetic/corticosteroid guided by ultrasound in 7 days). Group B: conventional bipolar radiofrequency "palisade". Target points were the lateral branch nerves of S1, S2, and S3, distance needles 1cm. Group C: modified bipolar radiofrequency "palisade" (needle distance >1cm). Patients were evaluated at one month, three months, and one year. Demographic data, VAS reduction, and side effects of the techniques were assessed. One month after the treatment, pain reduction was >50% in the three groups PDolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Use of radiofrequency in cosmetic dermatology: focus on nonablative treatment of acne scars

    Directory of Open Access Journals (Sweden)

    Simmons BJ

    2014-12-01

    Full Text Available Brian J Simmons, Robert D Griffith, Leyre A Falto-Aizpurua, Keyvan Nouri Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, University of Miami, Miami, FL, USA Abstract: Acne is a common affliction among many teens and some adults that usually resolves over time. However, the severe sequela of acne scarring can lead to long-term psychological and psychiatric problems. There exists a multitude of modalities to treat acne scars such as more invasive surgical techniques, subcision, chemical peels, ablative lasers, fractional lasers, etc. A more recent technique for the treatment of acne scars is nonablative radiofrequency (RF that works by passing a current through the dermis at a preset depth to produce small thermal wounds in the dermis which, in turn, stimulates dermal remodeling to produce new collagen and soften scar defects. This review article demonstrates that out of all RF modalities, microneedle bipolar RF and fractional bipolar RF treatments offers the best results for acne scarring. An improvement of 25%–75% can be expected after three to four treatment sessions using one to two passes per session. Treatment results are optimal approximately 3 months after final treatment. Common side effects can include transient pain, erythema, and scabbing. Further studies are needed to determine what RF treatment modalities work best for specific scar subtypes, so that further optimization of RF treatments for acne scars can be determined. Keywords: acne scarring, radiofrequency treatments, nonablative radiofrequency treatments, scars

  13. Treatment of hemicrania continua with radiofrequency ablation and long-term follow-up.

    Science.gov (United States)

    Beams, Jennifer L; Kline, Matthew T; Rozen, Todd D

    2015-11-01

    The objective of this research is to describe novel procedural treatments for hemicrania continua that allow patients to remain off indomethacin. Case reports are presented. We describe four distinct patients with indomethacin-responsive hemicrania continua who were unable to discontinue the use of indomethacin without headache recurrence. No other medications were effective for their syndrome. Secondary causes of headache were ruled out in each case. Each patient underwent diagnostic blockade of either the atlanto-axial joint, C2 dorsal root ganglion or sphenopalantine ganglion depending on their clinical examination and presence of cranial autonomic symptoms. A positive response led to a radiofrequency ablation of the C2 ventral ramus, C2 dorsal root ganglion or sphenopalantine ganglion, which provided headache relief in all case patients as complete as indomethacin. Long-term follow-up of these patients has shown that all have remained essentially headache free without the need for indomethacin. One patient has needed repeat radiofrequency procedures with consistent response. Hemicrania continua is defined by its sensitivity to indomethacin but very few patients are able to discontinue the medication without headache recurrence. As the risks of chronic indomethacin use are substantial, alternative treatments are necessary to protect patient health. We are now able to suggest several radiofrequency ablation procedures as effective as indomethacin with long-term follow-up. © International Headache Society 2015.

  14. Outcomes of Radiofrequency Ablation for Dysplastic Barrett’s Esophagus: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Carmelo Luigiano

    2016-01-01

    Full Text Available Barrett’s esophagus is a condition in which the normal squamous lining of the esophagus has been replaced by columnar epithelium containing intestinal metaplasia induced by recurrent mucosal injury related to gastroesophageal reflux disease. Barrett’s esophagus is a premalignant condition that can progress through a dysplasia-carcinoma sequence to esophageal adenocarcinoma. Multiple endoscopic ablative techniques have been developed with the goal of eradicating Barrett’s esophagus and preventing neoplastic progression to esophageal adenocarcinoma. For patients with high-grade dysplasia or intramucosal neoplasia, radiofrequency ablation with or without endoscopic resection for visible lesions is currently the most effective and safe treatment available. Recent data demonstrate that, in patients with Barrett’s esophagus and low-grade dysplasia confirmed by a second pathologist, ablative therapy results in a statistically significant reduction in progression to high-grade dysplasia and esophageal adenocarcinoma. Treatment of dysplastic Barrett’s esophagus with radiofrequency ablation results in complete eradication of both dysplasia and of intestinal metaplasia in a high proportion of patients with a low incidence of adverse events. A high proportion of treated patients maintain the neosquamous epithelium after successful treatment without recurrence of intestinal metaplasia. Following successful endoscopic treatment, endoscopic surveillance should be continued to detect any recurrent intestinal metaplasia and/or dysplasia. This paper reviews all relevant publications on the endoscopic management of Barrett’s esophagus using radiofrequency ablation.

  15. La parálisis cerebral en el cine

    OpenAIRE

    María Lucila MERINO MARCOS

    2005-01-01

    [ES] En los últimos veinticinco años se han rodado un número importante de películas en las que el protagonista o algún personaje secundario presentaban o simulaban una parálisis cerebral. Estos personajes en ocasiones han sido interpretados por personas con minusvalías. En la narración de su historia las cintas han incluido diversos aspectos sanitario-asistenciales, sociales y familiares obligados en el campo de la parálisis cerebral. [EN] In the last twenty-five years, a number of import...

  16. Transplantaciones tendinosas por parálisis radial

    OpenAIRE

    De la Puente, Luis; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú

    2014-01-01

    Entre las parálisis periféricas determinadas por lesiones traumáticas de los nervios, la parálisis del radial es la que origina mayores perturbaciones en las funciones del miembro. La inhabilitación del miembro enfermo es, generalmente, mas seria que la que ocasionan las lesiones del nervio cubital o del mediano, nervios que, funcionalmente, son susceptibles de suplirse en el territorio muscular que inervan conjuntamente. Among peripheral paralysis determined by traumatic nerve injuries, p...

  17. Predicting Spectral and PAR Light Attenuation in Greenlandic Coastal Waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Stedmon, Colin A.; Markager, Stiig

    present models for spectral and PAR (photosynthetically active radiation) attenuation in two contrasting Greenlandic fjords, Godthåbsfjord (SW Greenland) and Young Sound (NE Greenland). The fjords differ in the character and concentrations of optically active components present: dissolved organic material...... (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  18. Predicting spectral and PAR light attenuation in Greenlandic coastal waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Markager, Stiig; Stedmon, Colin

    present models for spectral and PAR (photosynthetically active radiation) attenuation in two contrasting Greenlandic fjords, Godthåbsfjord (SW Greenland) and Young Sound (NE Greenland). The fjords differ in the character and concentrations of optically active components present: dissolved organic material...... (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  19. Intoxication par la paraphényléne-diamine

    African Journals Online (AJOL)

    raoul

    9 mars 2011 ... La symptomatologie des intoxications aigues par la PPD est stéréotypée, le tableau clinique était dominé au départ par un oedème cervico-facial avec une ... réalisée chez 13% des patients devant une hyperkaliémie (8,6%) et/ou effondrement de la diurèse (5%), en moyenne 2 séances avec des extrêmes ...

  20. Intact and cleaved uPAR forms: diagnostic and prognostic value in cancer

    DEFF Research Database (Denmark)

    Rasch, M.G.; Lund, I.K.; Hoyer-Hansen, G.

    2008-01-01

    PA-catalyzed cleavage of uPAR is fast on the cell surface, when uPA is bound to a neighboring uPAR molecule. uPAR can be shed from the cell surface. However, the soluble form cannot be cleaved by uPA. Glycolipid-anchored and soluble forms of intact, uPAR(I-III), and cleaved receptor, uPAR(II-III) and uPAR(I), have been...... identified in tissue and body fluids. It is well-established, that the total amount of all uPAR forms is a strong prognostic marker in different types of cancer. Using immunoassays, measuring the individual uPAR forms, has revealed that the cleaved uPAR forms are even stronger prognostic markers and have...

  1. Novel technology in the treatment of acne scars: The matrix-tunable radiofrequency technology

    Directory of Open Access Journals (Sweden)

    M Ramesh

    2010-01-01

    Full Text Available Background : Despite the many advances, scarring, particularly acne or pimple scarring, does not have a satisfactory treatment. A new armamentarium in this field is this recently devised matrix-tunable radiofrequency technology, which utilizes radiofrequency emission in the treatment of acne scars. Aims : To evaluate the efficiency of the new matrix-tunable radiofrequency technology in patients with acne scars of varying sizes. Settings and Design : A prospective study of 30 randomly selected patients with acne scars was carried out. Materials and Methods : Thirty healthy patients with different types of acne scars - ice pick, box and rolling type - were randomly selected. The scars were either shallow or deep, varied in size from 2 to 20 mm and ranged in number from 10 to 50. These patients were first treated with broad-spectrum antibiotics and local exfoliating agents (topical tretinoin 0.025% and then subjected to matrix-tunable radiofrequency technology. Each scar was treated at intervals of 1 month. A maximum of four such sittings were carried out. Patients were followed-up every 15 days. Results were noted at the end of 2 months and 6 months. Improvement was assessed by using the visual analog scale (VAS at 2 months and 6 months, and results were noted in terms of percentage improvement of the whole face by calculating an average of percentage improvement on the basis of interviews of the patient and his/her accompanying relatives. The visual analog scaling was performed by means of high-resolution digital photographs taken at the baseline and at each subsequent visit. Results : The VAS improvement in scars ranged from 10 to 50% at the end of 2 months to 20 to 70% at the end of 6 months. Of the 30 patients of acne scars, the cosmetic result was excellent (>60% improvement in four, good (35-60% improvement in 18 and moderate to poor (<35% improvement in eight. A few patients reported burning sensation and a mild sunburn-like sensation for

  2. Efficacy and survival analysis of percutaneous radiofrequency versus microwave ablation for hepatocellular carcinoma: an Egyptian multidisciplinary clinic experience.

    Science.gov (United States)

    Abdelaziz, Ashraf; Elbaz, Tamer; Shousha, Hend Ibrahim; Mahmoud, Sherif; Ibrahim, Mostafa; Abdelmaksoud, Ahmed; Nabeel, Mohamed

    2014-12-01

    Hepatocellular carcinoma (HCC) is a primary tumor of the liver with poor prognosis. For early stage HCC, treatment options include surgical resection, liver transplantation, and percutaneous ablation. Percutaneous ablative techniques (radiofrequency and microwave techniques) emerged as best therapeutic options for nonsurgical patients. We aimed to determine the safety and efficacy of radiofrequency and microwave procedures for ablation of early stage HCC lesions and prospectively follow up our patients for survival analysis. One Hundred and 11 patients with early HCC are managed in our multidisciplinary clinic using either radiofrequency or microwave ablation. Patients are assessed for efficacy and safety. Complete ablation rate, local recurrence, and overall survival analysis are compared between both procedures. Radiofrequency ablation group (n = 45) and microwave ablation group (n = 66) were nearly comparable as regards the tumor and patients characteristics. Complete ablation was achieved in 94.2 and 96.1% of patients managed by radiofrequency and microwave ablation techniques, respectively (p value 0.6) with a low rate of minor complications (11.1 and 3.2, respectively) including subcapsular hematoma, thigh burn, abdominal wall skin burn, and pleural effusion. Ablation rates did not differ between ablated lesions ≤ 3 and 3-5 cm. A lower incidence of local recurrence was observed in microwave group (3.9 vs. 13.5% in radiofrequency group, p value 0.04). No difference between both groups as regards de novo lesions, portal vein thrombosis, and abdominal lymphadenopathy. The overall actuarial probability of survival was 91.6% at 1 year and 86.1% at 2 years with a higher survival rates noticed in microwave group but still without significant difference (p value 0.49). Radiofrequency and microwave ablations led to safe and equivalent ablation and survival rates (with superiority for microwave ablation as regards the incidence of local recurrence).

  3. Percutaneous treatment of hepatocellular carcinoma in patients with cirrhosis: A comparison of the safety of cryoablation and radiofrequency ablation

    Energy Technology Data Exchange (ETDEWEB)

    Dunne, Ruth M., E-mail: rmdunne@partners.org [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Shyn, Paul B., E-mail: pshyn@partners.org [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Sung, Jeffrey C., E-mail: jcsung@gmail.com [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Tatli, Servet, E-mail: statli@partners.org [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Morrison, Paul R. [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Catalano, Paul J., E-mail: pcata@jimmy.harvard.edu [Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, 450 Brookline Avenue, CLSB 11007, Boston, MA 02215 (United States); Department of Biostatistics, Harvard School of Public Health, Boston, MA 02215 (United States); Silverman, Stuart G., E-mail: sgsilverman@partners.org [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)

    2014-04-15

    Purpose: To compare the safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis. Materials and methods: This retrospective HIPAA-compliant study received institutional review board approval. Forty-two adult patients with cirrhosis underwent image-guided percutaneous ablation of hepatocellular carcinoma from 2003 to 2011. Twenty-five patients underwent 33 cryoablation procedures to treat 39 tumors, and 22 underwent 30 radiofrequency ablation procedures to treat 39 tumors. Five patients underwent both cryoablation and radiofrequency ablation procedures. Complication rates and severity per procedure were compared between the ablation groups. Potential confounding patient, procedure, and tumor-related variables were also compared. Statistical analyses included Kruskal–Wallis, Wilcoxon rank sum, and Fisher's exact tests. Two-sided P-values <0.05 were considered significant. Results: The overall complication rates, 13 (39.4%) of 33 cryoablation procedures versus eight (26.7%) of 30 radiofrequency ablation procedures and severe/fatal complication rates, two (6.1%) of 33 cryoablation procedures versus one (3.3%) of 30 radiofrequency ablation procedures, were not significantly different between the ablation groups (both P = 0.26). Severe complications included pneumothoraces requiring chest tube insertion during two cryoablation procedures. One death occurred within 90 days of a radiofrequency ablation procedure; all other complications were managed successfully. Conclusion: No significant difference was seen in the overall safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis.

  4. [A middle to long-term clinical study on pars flaccida and pars tensa cholesteatoma using survival analysis].

    Science.gov (United States)

    Somekawa, Yukihiro; Nagashima, Tsutomu; Masaki, Tomoyuki; Asano, Katsuji; Yajima, Ryoto; Himi, Tetsuo

    2014-12-01

    The current clinical study was performed on 311 cases of pars flaccida and 89 cases of pars tensa cholesteatoma which were treated with canal wall reconstructed tympanoplasty between 1991 and 2012. The average follow-up time of these patients was 5.3 years. Since follow-up periods were different in each case and some censored patients were involved, we used survival analysis on this study to discuss the cumulative rates of disease-free successful cases and the rates of recurrent cholesteatoma throughout the postoperative course. The disease-free successful cases were defined as those cases in which patients were both out of re-operation with recurrent and residual cholesteatoma and out of revision operation with another problem, furthermore, maintained good hearing outcome. Based on the criteria set by the Japan Otological Society (2010), the cases that satisfied the following were evaluated as good hearing results; (a) a successful case in which preoperative bone conduction was used, and (b) a case in which the postoperative air-bone gap was within 20dB after tympanoplasty for chronic otitis media. The analysis results were shown for each of (a) and (b). 1. In pars flaccida cholesteatoma, the 5-year survival rate of successful case was (a) 76.1% and (b) 83.9%, the 10-year survival rate was (a) 58.9% and (b) 73.0%. In pars tensa cholesteatoma, the 5-year survival rate of successful cases was (a) 57.7% and (b) 63.5%, the 10-year rate was (a) 42.1% and (b) 56.9%. A significant difference was seen between pars flaccida and pars tensa cholesteatoma (p pars flaccida cholesteatoma, the 5-year recurrence rate was 7.6% and the 10-year rate was 15.3%, and the recurrence rate increased gradually throughout the follow-up period. On the other hand, in pars tensa cholesteatoma, the increase in the recurrence rate reached a peak 15.8% at 5.5 years after the surgery. A long-term follow-up is necessary when evaluating the clinical results after tympanoplasty.

  5. A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay to quantify Parietaria judaica major allergens, Par j 1 and Par j 2.

    Science.gov (United States)

    Arilla, M C; González-Rioja, R; Ibarrola, I; Mir, A; Monteseirín, J; Conde, J; Martínez, A; Asturias, J A

    2006-01-01

    Parietaria pollen is one of the most important causes of pollinosis in Mediterranean countries. Parietaria judaica pollen extract presents two major allergens, Par j 1 and Par j 2, that belong to the lipid transfer protein family. To develop an ELISA for quantification of both major allergens of P. judaica pollen extracts, and to assert correlation of these allergens content with the allergenic activity of extracts. Natural Par j 1-Par j 2 allergens were purified by gel filtration, ion exchange, and affinity chromatography and identified by mass spectrometry. Rabbit antisera were obtained using this protein preparation as antigen and used for immunoaffinity purification of nPar j 1-Par j 2. BALB/c mice were immunized with the immunopurified nPar j 1-Par j 2 and after fusion and screening by direct ELISA, 5D4 monoclonal antibody was selected as capture antibody to develop a quantitative two-site ELISA. Bound proteins were detected by a biotinylated Par j 1-Par j 2-specific polyclonal antibody. The optimized ELISA was developed from 25 to 8000 pg/mL of purified Par j 1-Par j 2, and a linear portion of 200-1000 pg/mL. The intraassay and interassay coefficients of variation were lower than 7% and 14% respectively. The assay was very sensitive and specific as it had a detection limit of 25 pg/mL and did not detect reactivity with the same family plants, as Urtica. Par j 1-Par j 2 allergens content was measured in 14 P. judaica and two P. officinalis pollen extracts showing a significant correlation with their allergenic activity measured by enzyme allergosorbent test inhibition. The results proved the usefulness of the two-sandwich ELISA for the standardization of Parietaria pollen extracts intended for clinical use, because of its good correlation with allergenic potency.

  6. La lecture de Merleau-Ponty par Renaud Barbaras

    Czech Academy of Sciences Publication Activity Database

    Pechar, Jiří

    2015-01-01

    Roč. 11, č. 2 (2015), s. 1-6 ISSN 1336-6556 Institutional support: RVO:67985955 Keywords : Merleau-Ponty * Husserl * phenomenology * linguistics of Ferdinand de Saussure Subject RIV: AA - Philosophy ; Religion http://www.ostium.sk/sk/la-lecture-de-merleau-ponty-par-renaud-barbaras/

  7. Radiative transfer code: Application to the calculation of PAR

    Indian Academy of Sciences (India)

    Radiative transfer code: Application to the calculation of PAR. DEVRED EMMANUEL, DUBUISSON .... water vapor from Leckner (1978), with absorption coefficients for these gases taken from Gregg and. Carder (1990). ... law for the size distribution. The particle size ranges from 0.01 "m to 50 "m. 3. Validation of the code.

  8. Indications and Visual Outcome of First Hundred Pars Plana ...

    African Journals Online (AJOL)

    tulyasys

    Indications and Visual Outcome of First. Hundred Pars Plana Vitrectomies at Makkah. Specialist Eye Hospital, Kano, Nigeria. Abdulsalam Shuaib, Abdul Fattah Memon1. Department of Ophthalmology, Bayero University Kano/Aminu Kano Teaching Hospital, Kano State, Nigeria, 1Vitreoretinal Unit,. Al Ibrahim Eye Hospital, ...

  9. Indications and visual outcome of first hundred pars plana ...

    African Journals Online (AJOL)

    Conclusion: Rhegmatogenous retinal detachment and vitreous hemorrhage are the major indications for pars plana vitrectomy in this environment. As vitreoretinal disorders have become more common in this part of the world, there would be a corresponding increase in demand for vitreoretinal services. There is therefore a ...

  10. Sir Mokshagundam Visvesvaraya–A Visionary Engineer par ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 5. Sir Mokshagundam Visvesvaraya – A Visionary Engineer par Excellence. A V Shankara Rao. Article-in-a-Box Volume 7 Issue 5 May 2002 pp 3-5. Fulltext. Click here to view fulltext PDF. Permanent link:

  11. Efficacite et tolerance du captopril par voie sublinguale dans la ...

    African Journals Online (AJOL)

    insuffisance rénale chronique étaient les deux principales causes d'échec thérapeutique. Conclusion : Le captopril par voie sublinguale est donc aussi efficace chez le noir africain que chez le caucasien. Dans le contexte de pays en voie de ...

  12. Traitement De La Peripneumonie Contagieuse Bovine Par L ...

    African Journals Online (AJOL)

    oxytétracycline LA) dans le traitement des bovins atteints de péripneumonie contagieuse bovine (PPCB) et de déterminer le risque de transmission de la maladie à partir d'animaux traités. Une transmission expérimentale a été conduite par la mise ...

  13. Parasitisme des champs semenciers de cacaoyers par les ...

    African Journals Online (AJOL)

    SARAH

    30 janv. 2015 ... Parasitisme des champs semenciers de cacaoyers par les Loranthaceae dans la localité de Nkoemvone (sud. Cameroun). ONDOUA Joseph Marie1, DIBONG Siegfried Didier (2,3,4)*, TAFFOUO Victor Désiré (2,4), NGOTTA BIYON. Jacques Bruno (2). (1). Département de Botanique et de Physiologie ...

  14. Parasitisme de Dacryodes edulis par le genre Tapinanthus ...

    African Journals Online (AJOL)

    SARAH

    31 août 2013 ... hôtes de Dacryodes edulis alors que les autres ligneux cultivés étaient parasités par Phragmanthera capitata. Le taux moyen de ...... Mistletoes as parasites host specificity and speciation. Trends. Ecology and Evolution 13: 101-105. Peakall R, 1994. Interactions between orchids and ants. In: Orchid ...

  15. Aqueous misdirection following pars plana vitrectomy and silicone oil injection.

    Science.gov (United States)

    Ghoraba, Hammouda H; Ghali, Ali Ahmed; Mansour, Hosam Othman

    2015-01-01

    To report a retrospective series of seven phakic eyes of seven patients suffering from a malignant glaucoma-like syndrome following pars plana vitrectomy and silicone oil (SO) injection. Seven eyes with retinal detachment treated with pars plana vitrectomy with or without scleral buckling with SO tamponade. This was followed by cataract extraction to manage the elevated intraocular pressure (IOP). This was a retrospective review of seven cases that received pars plana vitrectomy and SO with or without scleral buckling for different causes of retinal detachment (three were rhegmatogenous and four were tractional). After a period ranging from 1 week to 1 month, they presented with malignant glaucoma-like manifestations; high IOP, shallow axial anterior chamber, and remarkable decrease of visual acuity. Atropine eye drops and anti-glaucoma medical treatment (topical and systemic) had been tried but failed to improve the condition. Dramatic decrease of IOP and deepening of the axial anterior chamber was observed in all cases in the first postoperative day after phacoemulsification and posterior chamber foldable intraocular lens implantation with posterior capsulotomy. Aqueous misdirection syndrome may be observed following pars plana vitrectomy and SO tamponade. This must be differentiated from other causes of post vitrectomy glaucoma. Cataract extraction with posterior capsulotomy controls the condition.

  16. BOREAS RSS-10 TOMS Circumpolar One-Degree PAR Images

    Science.gov (United States)

    Dye, Dennis G.; Holben, Brent; Nickeson, Jaime (Editor); Hall, Forrest G. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science (RSS)-10 team investigated the magnitude of daily, seasonal, and yearly variations of Photosynthetically Active Radiation (PAR) from ground and satellite observations. This data set contains satellite estimates of surface-incident PAR (400-700 nm, MJ/sq m) at one-degree spatial resolution. The spatial coverage is circumpolar from latitudes of 41 to 66 degrees north. The temporal coverage is from May through September for years 1979 through 1989. Eleven-year statistics are also provided: (1) mean, (2) standard deviation, and (3) coefficient of variation for 1979-89. The PAR estimates were derived from the global gridded ultraviolet reflectivity data product (average of 360, 380 nm) from the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS). Image mask data are provided for identifying the boreal forest zone, and ocean/land and snow/ice-covered areas. The data are available as binary image format data files. The PAR data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  17. Den eneste ene - hvordan etniske minoritetsunge i Danmark danner par

    DEFF Research Database (Denmark)

    Singla, Rashmi

    Rapporten handler om etniske unges måde at danne par på. Rapporten er baseret på en større empirisk undersøgelse gennemført af forfatteren i 2003 og er desuden inspireret af forfatterens egen ph.d.-afhandling: "Ungdom, etnicitet og psychosocial intervention" (2000, Københavns Universitet...

  18. Ankaferd Blood Stopper induces apoptosis and regulates PAR1 and ...

    African Journals Online (AJOL)

    Mine Mumcuoglu

    2014-12-16

    Dec 16, 2014 ... Expression analyses of PAR1, EPCR and p21 upon ABS treatment were performed by quantitative real time PCR. Annexin V ... 2014 Production and hosting by Elsevier B.V. on behalf of Ain Shams University. 1. Introduction. Ankaferd Blood ..... effects of Ankaferd as an alternative medicine. Altern Med Rev.

  19. Priapisme induit par la chlorpromazine: A propos de deux cas

    Directory of Open Access Journals (Sweden)

    I. Marrag

    2016-06-01

    Le priapisme veineux est une urgence urologique. Il constitue un des effets secondaires des neuroleptiques parmi les quels la chlorpromazine. Cet effet iatrogène, qui est rare mais grave, doit être connu par les cliniciens afin d’être mieux prévenu pour éviter les séquelles érectiles.

  20. Evaluation De L'activite Antifongique Par Bioautographie De ...

    African Journals Online (AJOL)

    Evaluation De L'activite Antifongique Par Bioautographie De Quelques Plantes Medicinales De Côte D'ivoire Contre Deux Formes Speciales De Fusarium Oxysporum. ... Fusariosis are among the most devastating diseases in crops, especially in tomato, cotton and banana. This study was carried out in order to identify ...

  1. PH motifs in PAR1&2 endow breast cancer growth.

    Science.gov (United States)

    Kancharla, A; Maoz, M; Jaber, M; Agranovich, D; Peretz, T; Grisaru-Granovsky, S; Uziely, B; Bar-Shavit, R

    2015-11-24

    Although emerging roles of protease-activated receptor1&2 (PAR1&2) in cancer are recognized, their underlying signalling events are poorly understood. Here we show signal-binding motifs in PAR1&2 that are critical for breast cancer growth. This occurs via the association of the pleckstrin homology (PH) domain with Akt/PKB as a key signalling event of PARs. Other PH-domain signal-proteins such as Etk/Bmx and Vav3 also associate with PAR1 and PAR2 through their PH domains. PAR1 and PAR2 bind with priority to Etk/Bmx. A point mutation in PAR2, H349A, but not in R352A, abrogates PH-protein association and is sufficient to markedly reduce PAR2-instigated breast tumour growth in vivo and placental extravillous trophoblast (EVT) invasion in vitro. Similarly, the PAR1 mutant hPar1-7A, which is unable to bind the PH domain, reduces mammary tumours and EVT invasion, endowing these motifs with physiological significance and underscoring the importance of these previously unknown PAR1 and PAR2 PH-domain-binding motifs in both pathological and physiological invasion processes.

  2. Radiofrequency thermal ablation of hepatocellular carcinoma: using contrast-enhanced harmonic power doppler sonography to assess treatment outcome.

    Science.gov (United States)

    Cioni, D; Lencioni, R; Rossi, S; Garbagnati, F; Donati, F; Crocetti, L; Bartolozzi, C

    2001-10-01

    We evaluated the accuracy of contrast-enhanced harmonic power Doppler sonography in assessing the outcome of radiofrequency thermal ablation of hepatocellular carcinoma. Fifty patients with 65 hepatocellular carcinoma nodules (1-5 cm in diameter; mean diameter, 2.5 cm) were studied using unenhanced and contrast-enhanced harmonic power Doppler sonography before and after IV administration of a microbubble contrast agent. The examinations were repeated after treatment of the tumors with radiofrequency ablation. Findings of the Doppler studies were compared with those of dual-phase helical CT, which were used as points of reference for assessing treatment outcome. Before radiofrequency treatment, intratumoral blood flow was revealed by unenhanced power Doppler sonography in 48 (74%) of 65 hepatocellular carcinoma nodules. After injection of the contrast agent, intratumoral enhancement was observed in 61 (94%) of 65 hepatocellular carcinomas (p enhancement on power Doppler sonograms. In nine of the 10 lesions that showed a residual viable tumor on helical CT scans, persistent intratumoral enhancement-matching the enhancing areas on helical CT images-was revealed by power Doppler sonography. These nine hepatocellular carcinomas were subjected to repeated radiofrequency thermal ablation with the guidance of contrast-enhanced power Doppler sonography. Complete necrosis was seen after the second treatment session in six of the nine lesions. Contrast-enhanced harmonic power Doppler sonography is an accurate technique for assessing the outcome of radiofrequency thermal ablation of hepatocellular carcinoma and may be useful in guiding additional treatment in patients with incomplete response to initial efforts.

  3. A comparison between pulsed radiofrequency and electro-acupuncture for relieving pain in patients with chronic low back pain.

    Science.gov (United States)

    Lin, Mu-Lien; Lin, Mu-Hung; Fen, Jun-Jeng; Lin, Wei-Tso; Lin, Chii-Wann; Chen, Po-Quang

    2010-01-01

    Many treatment options for chronic low back pain are available, including varied forms of electric stimulation. But little is known about the electricity effect between electro-acupuncture and pulsed radiofrequency. The objective of this study is to assess the difference in effectiveness of pain relief between pulsed radiofrequency and electro-acupuncture. Visual analog score (VAS) pain score, the Oswestry disability index (ODI) to measure a patient's permanent functional disability, and Short form 36 (SF-36) which is a survey used in health assessment to determine the cost-effectiveness of a health treatment, were used as rating systems to measure the pain relief and functional improvement effect of pulsed radiofrequency and electro-acupuncture, based on the methodological quality of the randomized controlled trials, the relevance between the study groups, and the consistency of the outcome evaluation. First, the baseline status before therapy shows no age and gender influence in the SF-36 and VAS score but it is significant in the ODI questionnaire. From ANOVA analyses, it is apparent that radiofrequency therapy is a significant improvement over electro-acupuncture therapy after one month. But electro-acupuncture also showed functional improvement in the lumbar spine from the ODI. This study provides sufficient evidence of the superiority of pulsed radiofrequency (PRF) therapy for low back pain relief compared with both electro-acupuncture (EA) therapy and the control group. But the functional improvement of the lumbar spine was proved under EA therapy only. Both therapies are related to electricity effects.

  4. Comparison of Extrapolation and Interpolation Methods for Estimating Daily Photosynthetically Active Radiation (PAR)

    NARCIS (Netherlands)

    Wu, G.; Skidmore, A.K.; Leeuw, de J.; Liu, X.; Prins, H.H.T.

    2010-01-01

    Measurements of photosynthetically active radiation (PAR), which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one interpolation methods for estimating daily PAR reaching the earth surface within the

  5. Alpine grassland fPAR change over the Northern Tibetan Plateau from 2002 to 2011

    National Research Council Canada - National Science Library

    CHEN Bao-Xiong ZHANG Xian-Zhou SUN Yu-Fang WANG Jing-Sheng HE Yong-Tao

    2017-01-01

    ...) and traditional in situ fPAR observation for measuring the in situ point fPAR of very short alpine grass vegetation were compared, and the Moderate Resolution Imaging Spectroradiometer (MODIS...

  6. Contamination des eaux de puits traditionnels par les nitrates sur le ...

    African Journals Online (AJOL)

    SARAH

    30 juin 2014 ... Objectif : La contamination des eaux souterraines par les nitrates ... Methodology and Results: the origin of nitrate water from traditional wells of Lobo's watershed was ..... avec celles faites par Hudak (1999) au Texas et Liu et.

  7. Apoplejía pituitaria con parálisis del III par craneal: Reporte de caso

    Directory of Open Access Journals (Sweden)

    Miguel Pinto Valdivia

    2011-10-01

    Full Text Available Se describe el caso de un varón de 65 años de edad, sin antecedentes patológicos de importancia, que acudió a emergencia del Hospital Nacional Cayetano Heredia por presentar cefalea intensa y ptosis palpebral izquierda. El examen físico mostró parálisis aislada del III par craneal izquierdo. Los análisis de laboratorio mostraron hiponatremia e hipopituitarismo y la resonancia magnética nuclear un adenoma pituitario con áreas de hemorragia e invasión de los senos cavernosos. El tratamiento incluyó glucocorticoides y descompresión quirúrgica transesfenoidal. La anatomía patológica confirmó el diagnóstico de infarto hemorrágico de un adenoma pituitario. El paciente fue dado de alta con terapia sustitutiva de levotiroxina y prednisona. La ptosis palpebral izquierda se recuperó en forma parcial. La apoplejía pituitaria es un síndrome clínico producido por un proceso expansivo dentro de la silla turca, secundario a hemorragia o infarto de un adenoma pituitario, que se caracteriza por cefalea, déficit visual, oftalmoplejía y alteración del nivel de conciencia. Este proceso expansivo puede comprimir los pares craneales en los senos cavernosos, produciendo diferentes grados de parálisis de los músculos oculomotores. La parálisis aislada del III par craneal es rara.(Rev Med Hered 2011;22:186-189.

  8. Temperature-controlled irrigated tip radiofrequency catheter ablation: comparison of in vivo and in vitro lesion dimensions for standard catheter and irrigated tip catheter with minimal infusion rate

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, A

    1998-01-01

    In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures <60% partly due to the limited lesion size after conventional radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion size, but has...

  9. Lesion dimensions during temperature-controlled radiofrequency catheter ablation of left ventricular porcine myocardium: impact of ablation site, electrode size, and convective cooling

    DEFF Research Database (Denmark)

    Høgh Petersen, H; Chen, X; Pietersen, A

    1999-01-01

    It is important to increase lesion size to improve the success rate for radiofrequency ablation of ischemic ventricular tachycardia. This study of radiofrequency ablation, with adjustment of power to approach a preset target temperature, ie, temperature-controlled ablation, explores the effect of...

  10. ParCAT: A Parallel Climate Analysis Toolkit

    Science.gov (United States)

    Haugen, B.; Smith, B.; Steed, C.; Ricciuto, D. M.; Thornton, P. E.; Shipman, G.

    2012-12-01

    Climate science has employed increasingly complex models and simulations to analyze the past and predict the future of our climate. The size and dimensionality of climate simulation data has been growing with the complexity of the models. This growth in data is creating a widening gap between the data being produced and the tools necessary to analyze large, high dimensional data sets. With single run data sets increasing into 10's, 100's and even 1000's of gigabytes, parallel computing tools are becoming a necessity in order to analyze and compare climate simulation data. The Parallel Climate Analysis Toolkit (ParCAT) provides basic tools that efficiently use parallel computing techniques to narrow the gap between data set size and analysis tools. ParCAT was created as a collaborative effort between climate scientists and computer scientists in order to provide efficient parallel implementations of the computing tools that are of use to climate scientists. Some of the basic functionalities included in the toolkit are the ability to compute spatio-temporal means and variances, differences between two runs and histograms of the values in a data set. ParCAT is designed to facilitate the "heavy lifting" that is required for large, multidimensional data sets. The toolkit does not focus on performing the final visualizations and presentation of results but rather, reducing large data sets to smaller, more manageable summaries. The output from ParCAT is provided in commonly used file formats (NetCDF, CSV, ASCII) to allow for simple integration with other tools. The toolkit is currently implemented as a command line utility, but will likely also provide a C library for developers interested in tighter software integration. Elements of the toolkit are already being incorporated into projects such as UV-CDAT and CMDX. There is also an effort underway to implement portions of the CCSM Land Model Diagnostics package using ParCAT in conjunction with Python and gnuplot. Par

  11. Attic cholesteatoma with tiny retraction of pars flaccida.

    Science.gov (United States)

    Lee, Jun Ho; Hong, Seok Min; Kim, Chang Woo; Park, Yeo Hoon; Baek, So-Hye

    2015-04-01

    This clinical study was performed to analyze the characteristics of attic cholesteatoma occurring behind a tiny retraction of the pars flaccida, which was classified as Tos type I or II and had an intact pars tensa of the tympanic membrane. The clinical records of patients who underwent tympanomastoidectomy for attic cholesteatoma at a tertiary care referral center (Kangdong Sacred Heart Hospital of Seoul, Korea) between March 2004 and December 2012 were retrospectively reviewed. Eleven patients (five men and six women) who underwent tympanomastoidectomy between March 2004 and December 2012 for attic cholesteatoma occurring behind a tiny attic retraction were included. The mean age of patients was 41.1 years (range 20-58 years) and the mean duration of follow-up was 29.5 months (range 13-52 months). Every patient had a unilateral cholesteatoma, and the opposite side was normal except in one patient. Hearing loss was the most common symptom, followed by earfullness and otalgia. Five patients had type I attic retraction, and six patients had type II attic retraction. No patient had definite scutum erosion. Interestingly, during regular postoperative checkup, one patient was found incidentally for the opposite ear. Six patients had a cholesteatoma sac that was separated from the pars flaccida, whereas in five patients it was in contact with the pars flaccida but was easily separated. Six patients had a limited cholesteatoma within the epitympanum, and five patients had extension beyond the epitympanum. The average air-bone gap was 24.3±10.1dB before the operation and 14.2±6.6dB after the operation. Every patient had an intact tympanic membrane without retraction pocket postoperatively. There was no recurrence of cholesteatoma during follow-up. The rate of attic cholesteatomas occurring behind a tiny retraction of the pars flaccida was 7.7% (11 of 142 patients with attic cholesteatoma). Attic retractions must be followed closely using endoscopy, microscopy, and

  12. Painless, safe, and efficacious noninvasive skin tightening, body contouring, and cellulite reduction using multisource 3DEEP radiofrequency.

    Science.gov (United States)

    Harth, Yoram

    2015-03-01

    In the last decade, Radiofrequency (RF) energy has proven to be safe and highly efficacious for face and neck skin tightening, body contouring, and cellulite reduction. In contrast to first-generation Monopolar/Bipolar and "X -Polar" RF systems which use one RF generator connected to one or more skin electrodes, multisource radiofrequency devices use six independent RF generators allowing efficient dermal heating to 52-55°C, with no pain or risk of other side effects. In this review, the basic science and clinical results of body contouring and cellulite treatment using multisource radiofrequency system (Endymed PRO, Endymed, Cesarea, Israel) will be discussed and analyzed. © 2015 Wiley Periodicals, Inc.

  13. The cost-effectiveness of radiofrequency catheter ablation as first-line treatment for paroxysmal atrial fibrillation

    DEFF Research Database (Denmark)

    Aronsson, Mattias; Walfridsson, Håkan; Janzon, Magnus

    2014-01-01

    AIM: The aim of this prospective substudy was to estimate the cost-effectiveness of treating paroxysmal atrial fibrillation (AF) with radiofrequency catheter ablation (RFA) compared with antiarrhythmic drugs (AADs) as first-line treatment. METHODS AND RESULTS: A decision-analytic Markov model......, based on MANTRA-PAF (Medical Antiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation) study data, was developed to study long-term effects and costs of RFA compared with AADs as first-line treatment. Positive clinical effects were found in the overall population, a gain......-effectiveness ratio of €3434/QALY in ≤50-year-old patients respectively €108 937/QALY in >50-year-old patients. CONCLUSION: Radiofrequency catheter ablation as first-line treatment is a cost-effective strategy for younger patients with paroxysmal AF. However, the cost-effectiveness of using RFA as first-line therapy...

  14. The Urokinase Receptor (uPAR) Facilitates Clearance of Borrelia burgdorferi

    NARCIS (Netherlands)

    Hovius, Joppe W. R.; Bijlsma, Maarten F.; van der Windt, Gerritje J. W.; Wiersinga, W. Joost; Boukens, Bastiaan J. D.; Coumou, Jeroen; Oei, Anneke; de Beer, Regina; de Vos, Alex F.; van 't Veer, Cornelis; van Dam, Alje P.; Wang, Penghua; Fikrig, Erol; Levi, Marcel M.; Roelofs, Joris J. T. H.; van der Poll, Tom

    2009-01-01

    The causative agent of Lyme borreliosis, the spirochete Borrelia burgdorferi, has been shown to induce expression of the urokinase receptor (uPAR); however, the role of uPAR in the immune response against Borrelia has never been investigated. uPAR not only acts as a proteinase receptor, but can

  15. 78 FR 42584 - Additional Designation of Aluminat, Pars Amayesh Sanaat Kish, Parviz Khaki, Pishro Systems...

    Science.gov (United States)

    2013-07-16

    ... Additional Designation of Aluminat, Pars Amayesh Sanaat Kish, Parviz Khaki, Pishro Systems Research Company... the Treasury and the Attorney General, has determined that Aluminat, Pars Amayesh Sanaat Kish, Parviz..., Parcham Street, Arak, Iran PARS Amayesh Sanaat Kish AKA: PASK AKA: Vacuumkaran AKA: Vacuum Karan AKA...

  16. Five-Port Combined Limbal and Pars Plana Vitrectomy for Infectious Endophthalmitis.

    Science.gov (United States)

    Xu, Kunyong; Chin, Eric K; Almeida, David R P

    2016-01-01

    Pars plana vitrectomy for acute infectious endophthalmitis can be challenging due to severe inflammation in the anterior chamber creating significant media opacity. We describe a surgical technique combining limbal based vitrectomy and pars plana vitrectomy to manage acute infectious endophthalmitis. Limbal based vitrectomy facilitates removal of anterior chamber fibrin and inflammatory membranes for safe and optimal posterior pars plana vitrectomy.

  17. 12 CFR 925.19 - Par value and price of stock.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Par value and price of stock. 925.19 Section... ASSOCIATES MEMBERS OF THE BANKS Stock Requirements § 925.19 Par value and price of stock. The capital stock of each Bank shall be sold at par, unless the Board has fixed a higher price. ...

  18. Neo-Positivist Intrusions, Post-Qualitative Challenges, and PAR's Generative Indeterminacies

    Science.gov (United States)

    Miller, Janet L.

    2017-01-01

    Although committed to PAR's overarching aspirations, many advocates also have noted myriad complexities of engaging in PAR, where ambiguities and disarrays--all kinds of inconclusive evidence--can proliferate. Uncertainties especially can erupt if PAR education-focused projects are positioned, oxymoronically, as expected to produce "high…

  19. Is There an "F" in Your PAR? Understanding, Teaching and Doing Action Research

    Science.gov (United States)

    Lorenzetti, Liza; Walsh, Christine Ann

    2014-01-01

    Participatory Action Research (PAR) is increasingly recognized within academic research and pedagogy. What are the benefits of including feminism within participatory action research and teaching? In responding to this question, we discuss the similarities and salient differences between PAR and feminist informed PAR (FPAR). There are eight themes…

  20. A network of cis and trans interactions is required for ParB spreading

    Science.gov (United States)

    Song, Dan; Rodrigues, Kristen; Graham, Thomas G.W.

    2017-01-01

    Abstract Most bacteria utilize the highly conserved parABS partitioning system in plasmid and chromosome segregation. This system depends on a DNA-binding protein ParB, which binds specifically to the centromere DNA sequence parS and to adjacent non-specific DNA over multiple kilobases in a phenomenon called spreading. Previous single-molecule experiments in combination with genetic, biochemical and computational studies have argued that ParB spreading requires cooperative interactions between ParB dimers including DNA bridging and possible nearest-neighbor interactions. A recent structure of a ParB homolog co-crystallized with parS revealed that ParB dimers tetramerize to form a higher order nucleoprotein complex. Using this structure as a guide, we systematically ablated a series of proposed intermolecular interactions in the Bacillus subtilis ParB (BsSpo0J) and characterized their effect on spreading using both in vivo and in vitro assays. In particular, we measured DNA compaction mediated by BsSpo0J using a recently developed single-molecule method to simultaneously visualize protein binding on single DNA molecules and changes in DNA conformation without protein labeling. Our results indicate that residues acting as hubs for multiple interactions frequently led to the most severe spreading defects when mutated, and that a network of both cis and trans interactions between ParB dimers is necessary for spreading. PMID:28407103

  1. Is radiofrequency treatment effective for shoulder impingement syndrome? A prospective randomized controlled study.

    Science.gov (United States)

    Lu, Yi; Zhang, Qiang; Zhu, Yiming; Jiang, Chunyan

    2013-11-01

    To determine whether radiofrequency based plasma microtenotomy has a positive effective in the treatment of shoulder impingement syndrome with cuff tendinosis. Eighty patients with impingement syndrome and cuff tendinosis that were treated arthroscopically were enrolled in the study. The patients were randomly assigned to receive either arthroscopic subacromial decompression (ASD) alone (ASD group, n = 40) or arthroscopic subacromial decompression combined with radiofrequency (RF) based plasma microtenotomy (RF group, n = 40). Clinical outcome data including VAS pain score, shoulder range of motion (ROM), ASES, UCLA, Constant-Murley, and SST score were recorded preoperatively and at 3 weeks, 6 weeks, 3 months, 6 months, and 1 year postoperatively. Sixty-five out of eighty patients (81.3%) were available for the final follow-up at 1 year postoperation. There were 32 patients in the ASD group and 33 in the RF group. Both treatment groups showed significantly (P = .031 in the ASD group vs P = .017 in the RF group) reduced pain 3 weeks postoperatively. Both treatment groups showed significantly improved functional scores 3 months postoperatively. Both treatment groups showed significantly improved flexion elevation (FE) and external rotation (ER) 1 year postoperatively and internal rotation (IR) 6 months postoperatively. No significant difference between the 2 groups was found in any of the outcome measurements at any time point postoperatively. Arthroscopic subacromial decompression is a reliable treatment for refractory impingement syndrome. The additional radiofrequency based plasma microtenotomy did not show any significant positive effects regarding pain relief, ROM, or functional recovery. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  2. Exposure to radio-frequency electromagnetic fields and behavioural problems in Bavarian children and adolescents.

    Science.gov (United States)

    Thomas, Silke; Heinrich, Sabine; von Kries, Rüdiger; Radon, Katja

    2010-02-01

    Only few studies have so far investigated possible health effects of radio-frequency electromagnetic fields (RF EMF) in children and adolescents, although experts discuss a potential higher vulnerability to such fields. We aimed to investigate a possible association between measured exposure to RF EMF fields and behavioural problems in children and adolescents. 1,498 children and 1,524 adolescents were randomly selected from the population registries of four Bavarian (South of Germany) cities. During an Interview data on participants' mental health, socio-demographic characteristics and potential confounders were collected. Mental health behaviour was assessed using the German version of the Strengths and Difficulties Questionnaire (SDQ). Using a personal dosimeter, we obtained radio-frequency EMF exposure profiles over 24 h. Exposure levels over waking hours were expressed as mean percentage of the reference level. Overall, exposure to radiofrequency electromagnetic fields was far below the reference level. Seven percent of the children and 5% of the adolescents showed an abnormal mental behaviour. In the multiple logistic regression analyses measured exposure to RF fields in the highest quartile was associated to overall behavioural problems for adolescents (OR 2.2; 95% CI 1.1-4.5) but not for children (1.3; 0.7-2.6). These results are mainly driven by one subscale, as the results showed an association between exposure and conduct problems for adolescents (3.7; 1.6-8.4) and children (2.9; 1.4-5.9). As this is one of the first studies that investigated an association between exposure to mobile telecommunication networks and mental health behaviour more studies using personal dosimetry are warranted to confirm these findings.

  3. 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.)

  4. Efficacy of percutaneous intraductal radiofrequency ablation combined with biliary stenting in treatment of malignant biliary obstruction

    Directory of Open Access Journals (Sweden)

    ZHANG Kai

    2015-05-01

    Full Text Available ObjectiveTo investigate the safety and feasibility of percutaneous intraductal radiofrequency ablation (palliative therapy in the treatment of malignant obstructive jaundice. MethodsThis study included 20 patients with unresectable malignant obstructive jaundice, who were treated in the First Affiliated Hospital of Zhengzhou University from January 2013 to March 2014. Nine of them (test group underwent percutaneous intraductal radiofrequency ablation plus metallic biliary stent placement. The other 11 similar cases (control group underwent metallic biliary stent placement alone after successful percutaneous transhepatic cholangiography. Operative complications and remission of jaundice were observed, and the stent patency after at 3 and 6 months after operation was evaluated and compared between the two groups. ResultsAll patients were followed completely by outpatient or telephone. The stent patency rate at 3 months after operation was 9/9 in the test group and 8/11 in the control group (χ2=2.888, P=0.218, and the stent patency rates at 6 months were 7/8 and 3/11, respectively (χ2=6.739, P=0.02. During follow-up, one case in the test group died of gastrointestinal bleeding at 113 d after operation; one case in the control group died of liver failure at 57 d after operation and one case died of disseminated intravascular coagulation at 142 d. ConclusionPercutaneous intraductal radiofrequency ablation is safe and feasible in the treatment of malignant biliary obstruction, and the preliminary efficacy in prolonging the patency of self-expanding metallic stent is satisfactory. However, this therapy needs to be further verified via large-sample randomized controlled studies.

  5. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. 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

    2017-12-01

    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 < .05) in the levels of germinal epithelial diameter in all the experimental groups compared with the control group. There was no significant change (p < .05) in cross-sectional diameter of all the experimental groups compared with the control group. Group D rats showed a significant decrease (p ˂ .05) in lumen diameter compared with group B rats. There was an uneven distribution of germinal epithelial cells in groups B, C and D. However, there was degeneration of the epithelia cells in group D when compared to the control and group B rats. Sera levels of malondialdehyde (MDA) and superoxide dismutase (SOD), which are markers of reactive oxygen species, significantly increased (MDA) and decreased (SOD), respectively, in all the experimental groups compared with the control group. Also sera levels of gonadotropic hormones (FSH, LH and testosterone) significantly decreased (p < .05) in groups C and D compared with the control group. The study demonstrates that chronic exposure to radiofrequency electromagnetic radiation of cell phone leads to defective testicular function that is associated with increased oxidative stress and decreased

  7. Hardware and software platform for real-time processing and visualization of echographic radiofrequency signals.

    Science.gov (United States)

    Scabia, Marco; Biagi, Elena; Masotti, Leonardo

    2002-10-01

    In this paper the architecture of a hardware and software platform, for ultrasonic investigation is presented. The platform, used in conjunction with an analog front-end hardware for driving the ultrasonic transducers of any commercial echograph, having the radiofrequency echo signal access, make it possible to dispose of a powerful echographic system for experimenting any processing technique, also in a clinical environment in which real-time operation mode is an essential prerequisite. The platform transforms any echograph into a test-system for evaluating the diagnostic effectiveness of new investigation techniques. A particular user interface was designed in order to allow a real-time and simultaneous visualization of the results produced in the different stages of the chosen processing procedure. This is aimed at obtaining a better optimization of the processing algorithm. The most important platform aspect, which also constitutes the basic differentiation with respect to similar systems, is the direct processing of the radiofrequency echo signal, which is essential for a complete analysis of the particular ultrasound-media interaction phenomenon. The platform completely integrates the architecture of a personal computer (PC) giving rise to several benefits, such as the quick technological evolution in the PC field and an extreme degree of programmability for different applications. The PC also constitutes the user interface, as a flexible and intuitive visualization support, and performs some software signal processing, by custom algorithms and commercial libraries. The realized close synergy between hardware and software allows the acquisition and real-time processing of the echographic radiofrequency (RF) signal with fast data representation.

  8. A prospective multicenter trial of bipolar radiofrequency ablation for atrial fibrillation: early results.

    Science.gov (United States)

    Mokadam, Nahush A; McCarthy, Patrick M; Gillinov, A Marc; Ryan, William H; Moon, Marc R; Mack, Michael J; Gaynor, Sydney L; Prasad, Sunil M; Wickline, Samuel A; Bailey, Marci S; Damiano, Nicholas R; Ishii, Yosuke; Schuessler, Richard B; Damiano, Ralph J

    2004-11-01

    The Cox-Maze III remains the gold standard for the surgical treatment of atrial fibrillation. However, the "cut-and-sew" technique is time consuming and technically challenging. The pulmonary veins are the source of ectopy in the majority of patients with atrial fibrillation. The safety and efficacy of bipolar radiofrequency to electrically isolate the pulmonary veins was evaluated in a prospective multi-center trial. Beginning in January 2002, 30 patients at three medical centers underwent pulmonary vein isolation using bipolar radiofrequency and were followed for 6 months. Twenty-four of the patients also underwent a modified Cox-Maze III. Electrical isolation of the pulmonary veins was confirmed with intraoperative pacing. Pulmonary vein patency was assessed by magnetic resonance imaging or three-dimensional computed tomography in 15 patients at 1 month. Mean age was 60.9 +/- 11.7 years. Nineteen patients had paroxysmal atrial fibrillation. All pulmonary veins were isolated in every patient. The left pulmonary veins underwent 3.0 +/- 1.4 applications for a total of 26.4 +/- 10.5 seconds. The right pulmonary veins underwent 2.8 +/- 1.1 applications for a total of 26.3 +/- 12.6 seconds. There was no operative mortality. At 1 month, imaging revealed no evidence of pulmonary vein stenosis. At 6 months, 96% of patients were in normal sinus rhythm. The use of bipolar radiofrequency for electrical isolation of pulmonary veins and to replace other Cox-Maze III incisions is safe and effective at controlling atrial fibrillation. This emerging technology may shorten and simplify the surgical management of atrial fibrillation.

  9. Safety and feasibility of endoscopic biliary radiofrequency ablation treatment of extrahepatic cholangiocarcinoma.

    Science.gov (United States)

    Laquière, A; Boustière, C; Leblanc, S; Penaranda, G; Désilets, E; Prat, F

    2016-03-01

    Biliary bipolar radiofrequency ablation (RFA) is a new treatment for extrahepatic cholangiocarcinoma (CCA) currently under evaluation. The purpose of this study was to evaluate the safety, particularly biliary fistula occurrence, and the feasibility of biliary RFA in a homogeneous group of patients treated using the same RFA protocol. Twelve patients with inoperable or unresectable CCA were included in a bicentric case series study. After removal of biliary plastic stents, a radiofrequency treatment with a new bipolar probe (Habib™ EndoHBP) was applied. The energy was delivered by a RFA generator (VIO 200 D), supplying electrical energy at 350 kHz and 10 W for 90 s. At the end of the procedure, one or more biliary stents were left in place. Adverse events were assessed per-procedure and during follow-up visits. CCA was confirmed in all patients by histology (66%), locoregional evolution or metastatic evolution. The types of CCA were Bismuth I stage (N = 4), Bismuth II stage (N = 3), Bismuth III stage (N = 2) and Bismuth IV stage (N = 3). No serious adverse events occurred within 30 days following endoscopic treatment: One patient had a sepsis due to bacterial translocation on day 1 and another had an acute cholangitis on day 12 due to early stent migration. No immediate or delayed biliary fistula was reported. The ergonomics of the probe made treatment easy in 100 % of cases. Mean survival was 12.3 months. Endoscopic radiofrequency treatment of inoperable CCA appears without major risks and is feasible. No major adverse events or biliary fistula were identified.

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

    Science.gov (United States)

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

    2013-05-01

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

  11. Radiofrequency ablation of stellate ganglion in a patient with complex regional pain syndrome

    Directory of Open Access Journals (Sweden)

    Chinmoy Roy

    2014-01-01

    Full Text Available Complex regional pain syndrome (CRPS is characterized by a combination of sensory, motor, vasomotor, pseudomotor dysfunctions and trophic signs. We describe the use of radiofrequency (RF ablation of Stellate ganglion (SG under fluoroscopy, for long-term suppression of sympathetic nervous system, in a patient having CRPS-not otherwise specified. Although the effects of thermal RF neurolysis may be partial or temporary, they may promote better conditions toward rehabilitation. The beneficial effect obtained by the RF neurolysis of SG in this particular patient strongly advocates the use of this mode of therapy in patients with CRPS.

  12. Pulsed Radiofrequency Treatment of Complex Regional Pain Syndrome: A Case Series

    Directory of Open Access Journals (Sweden)

    Vlad Djuric

    2014-01-01

    Full Text Available BACKGROUND: Various forms of sympathetic chain neurolysis (sympathectomy have, at one time or another, held promise as effective treatment options for complex regional pain syndrome (CRPS. Complications, such as worsening pain and the development of new pain syndromes, have prevented sympathectomy from emerging as a standard intervention. In an effort to avoid poor outcomes associated with neurolysis, pulsed radiofrequency (PRF has been proposed as a potential treatment alternative for a number of chronic neuropathic pain states, including some forms of CRPS.

  13. Stabilized operation of the Spallation Neutron Source radio-frequency quadrupole

    Directory of Open Access Journals (Sweden)

    Sang-ho Kim

    2010-07-01

    Full Text Available The Spallation Neutron Source (SNS radio-frequency quadrupole (RFQ had resonance control instabilities at duty factors higher than approximately 4%. Systematic investigations have been carried out to understand the cause of the instability and to ensure the operational stability of the RFQ. The most critical source of the instability is revealed to be an interaction between hydrogen released by beam bombardments and the RFQ rf field resulting in a discharge, which consumes additional rf power and could cause the RFQ to operate in an unstable region. This paper reports improvement of the SNS RFQ operational stability based on the findings during the SNS operation.

  14. Anti-collision radio-frequency identification system using passive SAW tags

    Science.gov (United States)

    Sorokin, A. V.; Shepeta, A. P.

    2017-06-01

    Modern multi sensor systems should have high operating speed and resistance to climate impacts. Radiofrequency systems use passive SAW tags for identification items and vehicles. These tags find application in industry, traffic remote control systems, and railway remote traffic control systems for identification and speed measuring. However, collision of the passive SAW RFID tags hinders development passive RFID SAW technology in Industry. The collision problem for passive SAW tags leads for incorrect identification and encoding each tag. In our researching, we suggest approach for identification of several passive SAW tags in collision case.

  15. Pulsed radiofrequency ablation for treatment of severe pain after shoulder arthroplasty (case report

    Directory of Open Access Journals (Sweden)

    D. V. Zabolotsky

    2015-01-01

    Full Text Available A case of refractory neuropathic pain syndrome in patient who underwent monopolar shoulder replacement is presented. The patient had right lung tumor metastasis in the right humeral head. Severe neuropathic pain syndrome, not responding to 6-months conservative treatment, developed in post-operative period. Pulsed radiofrequency ablation of C4-C6 nerve roots via interscalene access was performed. The procedure allowed the patient to stop taking painkillers and improved his quality of life. The patient was monitored for 2 months.

  16. Radiofrequency identification and medical devices: the regulatory framework on electromagnetic compatibility. Part I: medical devices.

    Science.gov (United States)

    Censi, Federica; Mattei, Eugenio; Triventi, Michele; Bartolini, Pietro; Calcagnini, Giovanni

    2012-05-01

    Radiofrequency identification (RFID) technology has acheived significant success and has penetrated into various areas of healthcare. Several RFID-based applications are used in various modalities with the ultimate aim of improving patient care. When a wireless technology is used in a healthcare environment, attention must be paid to the potential risks deriving from its use; one of the most important being electromagnetic interference with medical devices. In this paper, the regulatory framework concerning the electromagnetic compatibility between RFID and medical devices is analyzed to understand whether and how the application of the current standards allows for the effective control of the risks of electromagnetic interference.

  17. Distributed fiber temperature and strain sensor using coherent radio-frequency detection of spontaneous Brillouin scattering

    Science.gov (United States)

    Geng, Jihong; Staines, Sean; Blake, Mike; Jiang, Shibin

    2007-08-01

    A novel technique that enables coherent detection of spontaneous Brillouin scattering in the radio-frequency (<500 MHz) region with excellent long-term stability has been demonstrated for distributed measurements of temperature and strain in long fiber. An actively stabilized single-frequency Brillouin fiber laser with extremely low phase noise and intensity noise is used as a well-defined, frequency-shifted local oscillator for the heterodyne detection, yielding measurements of spontaneous Brillouin scattering with high frequency stability. Based on this approach, a highly stable real-time fiber sensor for distributed measurements of both temperature and strain over long fiber has been developed utilizing advanced digital signal processing techniques.

  18. Radiofrequency kyphoplasty - a case report on mulitple osteoporotic sintering of the lumbar spine

    Directory of Open Access Journals (Sweden)

    Schekelmann R

    2011-01-01

    Full Text Available At St. Marien Hospital, 176 patients with osteoporotic vertebral fractures were treated with balloon kyphoplasty (BKP from January 2007 to September 2009. The functional outcome was good and no relevant complications were encountered. Since September 2009, a further 41 patients with the same indication have been treated with the new procedure of radiofrequency (RF kyphoplasty (DFine. Operating times were markedly shorter and the extravasation of cement was reduced by two thirds. We encountered no complications or circulatory problems. The new procedure (RF kyphoplasty resulted in equally good functional results as did BKP, required less time in the operating room, and reduced the number of negative side effects.

  19. Measurement of radio-frequency temporal phase modulation using spectral interferometry

    Science.gov (United States)

    Jachura, Michał; Szczepanek, Jan; Wasilewski, Wojciech; Karpiński, Michał

    2018-02-01

    We present an optical method to measure radio-frequency electro-optic phase modulation profiles by employing spectrum-to-time mapping realized by highly chirped optical pulses. We directly characterize temporal phase modulation profiles of up to 12.5 GHz bandwidth, with temporal resolution comparable to high-end electronic oscilloscopes. The presented optical setup is a valuable tool for direct characterization of complex temporal electro-optic phase modulation profiles, which is indispensable for practical realization of deterministic spectral-temporal reshaping of quantum light pulses.

  20. Prevention and treatment of complications after radiofrequency ablation for hepatic tumors in high-risk locations

    Directory of Open Access Journals (Sweden)

    SONG Li

    2017-04-01

    Full Text Available Percutaneous radiofrequency ablation (RFA has been widely used in the treatment of malignant hepatic tumors and has achieved satisfactory effects. Complications after RFA have been taken seriously and the risk of the development of complications is closely associated with tumor location. It is a great challenge for physicians to perform RFA for hepatic tumors in high-risk locations due to related difficulties and risks. This article reviews the complications after RFA for hepatic tumors in high-risk locations and analyzes related control strategies.

  1. Tumor lysis syndrome following endoscopic radiofrequency interstitial thermal ablation of colorectal liver metastases.

    LENUS (Irish Health Repository)

    Barry, B D

    2012-02-03

    Radiofrequency interstitial thermal ablation (RITA) provides a palliative option for patients suffering from metastatic liver disease. This procedure can be performed using a laparoscopic approach with laparoscopic ultrasound used to position the RITA probe. We describe a case of laparoscopic RITA performed for colorectal liver metastasis that was complicated by tumor lysis syndrome (TLS) following treatment. We consider RITA to be a safe procedure, as supported by the literature, but where intracorporal tumor lysis is the treatment goal we believe that the systemic release of tumor products can overwhelm the excretory capacity; therefore, TLS is an inevitable consequence in some patients.

  2. Combination therapy of temporary tracheal stenting and radiofrequency ablation for multinodular thyroid goiter with airway compression

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ji Hoon; Beak, Jung Hwan; Oh, Yeon Mok; Ha, Eun Ju; Lee, Jeong Hyun [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2013-10-15

    We report a case of multinodular thyroid goiter in an 80-year-old man who successfully underwent tracheal stent placement for respiratory distress caused by the thyroid goiter and following two radiofrequency (RF) ablation sessions performed for thyroid volume reduction. This sequential treatment allowed elective stent removals four weeks after the second RF ablation session because the thyroid volume had been progressively reduced. Combination therapy of temporary airway stenting and RF ablation for the treatment of thyroid goiter has two advantages, i.e., immediate reliefs of dyspnea with airway stenting and reductions of the thyroid volume with RF ablation, and thus, allowing symptom reliefs even after the stent removals.

  3. 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.

  4. Single particle dynamics in a radio-frequency produced plasma sheath

    Science.gov (United States)

    Rubin-Zuzic, M.; Nosenko, V.; Zhdanov, S.; Ivlev, A.; Thomas, H.; Khrapak, S.; Couedel, L.

    2018-01-01

    Recently different research groups have investigated the motion of a single dust particle levitated in a rf plasma. Here we describe a highly resolved experiment where a single spherical melamine formaldehyde microparticle is suspended in the plasma sheath above the lower electrode of a capacitively coupled radio-frequency discharge at controlled pressure, power and neutral gas flow rate. The particle's horizontal oscillation is investigated, from which its neutral gas damping rate, kinetic temperature and eigenfrequency of the potential trap are measured. Compared to prior experiments we report about inhomogeneous and anisotropic velocity variations.

  5. Donor Kidney With Renal Cell Carcinoma Successfully Treated With Radiofrequency Ablation

    DEFF Research Database (Denmark)

    Christensen, S F; Hansen, Jesper Melchior

    2015-01-01

    BACKGROUND: The risk of donor-transmitted cancer is evident. CASE REPORT: We report the case of a 69-year-old woman who was transplanted with a kidney from a deceased donor. Four days after transplantation a routine ultrasound scan revealed a 3-cm tumor in the middle-upper pole of the allograft....... A biopsy showed the tumor to be papillary renal cell carcinoma. The patient was treated with radiofrequency ablation. This procedure was complicated by the development of a cutaneous fistula and open surgery was done with resection of an area of necrosis in the kidney and of the fistula. The maintenance...

  6. Radiofrequency Identification by using Drones in Railway Accidents and Disaster Situations

    Directory of Open Access Journals (Sweden)

    Géza Károly Kiss Leizer

    2017-06-01

    Full Text Available Today, railway operation procedures include the transportation of large amount of hazardous substances. Our research has been motivated by the desire to find concrete and urgent solutions to the safety issues of handling waste generated manly in case of accidents and disaster situations during the transportation of hazardous substances In order to ensure safety in the transportation of dangerous goods, and to facilitate the fast and efficient waste handling of hazardous substances released into the environment during unexpected events, we have elaborated a new method, in which we suggest the radiofrequency identification of dangerous consignments in case of disaster situations by the use of drones.

  7. In vivo imaging of a stable paramagnetic probe by pulsed-radiofrequency electron paramagnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Murugesan; Cook; Devasahayam

    1997-01-01

    Imaging of free radicals by electron paramagnetic resonance (EPR) spectroscopy using time domain acquisition as in nuclear magnetic resonance (NMR) has not been attempted because of the short spin-spin relaxation times, typically under 1 μs, of most biologically relevant paramagnetic species......, Recent advances in radiofrequency (RF) electronics have enabled the generation of pulses of the order of 10-50 ns. Such short pulses provide adequate spectral coverage for EPR studies at 300 MHz resonant frequency. Acquisition of free induction decays (FID) of paramagnetic species possessing...

  8. Pulsed Radiofrequency in the Treatment of Persistent Pain After Inguinal Herniotomy

    DEFF Research Database (Denmark)

    Werner, Mads U; Bischoff, Joakim Mutahi; Rathmell, James P

    2012-01-01

    ABSTRACT: In the United States, it is estimated that between 6000 and 18,000 individuals each year present with disabling pain after inguinal hernia repair. Although surgical treatment with mesh removal is one of few options available, effective alternatives to nonsurgical management are needed....... The use of pulsed radiofrequency (PFR), leading to nondestructive lesions of nerve structures, has been proposed as a treatment option. To examine the evidence of treatment efficacy, a systematic literature search was made. From the databases PubMed, Embase, and CINAHL, 4 case reports were retrieved and 8...

  9. Avis 6 sur la formation à et par la recherche

    OpenAIRE

    Centre de Coopération Internationale en Recherche Agronomique pour le Développement

    2015-01-01

    La formation à et par la recherche s’appuie sur la démarche scientifique, les savoirs, les connaissances à transmettre, tout autant que l’acquisition de compétences en gestion de projet, de capacités au travail en équipe, d’une ouverture d’esprit qui favorisera la créativité. Elle doit permettre de prendre conscience de la responsabilité endossée par la communauté scientifique vis-à-vis de la société et de l’environnement, mais aussi préparer l’avenir professionnel de celle ou de celui qu...

  10. La syphilis congenitale revelee par une fracture spontanee

    Directory of Open Access Journals (Sweden)

    Mounia Lakhdar Idrissi

    2011-11-01

    Full Text Available Alors qu�elle est actuellement oubliee dans les pays developpes, la syphilis congenitale se voit encore chez nous faute du depistage antenatal. Ses formes cliniques sont polymorphes et orientent a tord vers d�autres pathologies surtout en periode neonatale. Le diagnostic n�est donc pas toujours facile. La revelation d�une syphilis congenitale par une fracture spontanee est exceptionnellement decrite. Nous rapportons dans ce travail le cas d�un nourrisson de 2 mois ramene en consultation pour limitation douloureuse des mouvements du bras droit. Le diagnostic est evoque sur les donnees radiologiques et confirme par la serologie syphilitique. Le traitement a repose essentiellement sur l�administration de la penicilline G avec une bonne evolution clinique.

  11. Chaos quantique avec des atomes refroidis par laser

    OpenAIRE

    Lignier, Hans; Thommen, Quentin; Chabé, Julien; Delande, Dominique; Garreau, Jean Claude; Szriftgiser, Pascal; Zehnlé, Véronique

    2005-01-01

    Conférence présentée au 5e Colloque "Chaos Temporel et Chaos Spatio-Temporel", Le Havre, décembre 2005; La dynamique des systèmes chaotiques est le sujet de nombreuses études en physique. Après les percées accomplies par Poincaré au début du XXe siècle, les idées se sont fixées avec la découverte par Lorenz dans les années 60 de la ``sensibilité aux conditions initiales'', qui découle de la non linéarité des équations du mouvement. Plusieurs difficultés se présentent cependant quand l'on tent...

  12. Insights into energy delivery to myocardial tissue during radiofrequency ablation through application of the first law of thermodynamics.

    Science.gov (United States)

    Bunch, T Jared; Day, John D; Packer, Douglas L

    2009-04-01

    The approach to catheter-based radiofrequency ablation of atrial fibrillation has evolved, and as a consequence, more energy is delivered in the posterior left atrium, exposing neighboring tissue to untoward thermal injury. Simultaneously, catheter technology has advanced to allow more efficient energy delivery into the myocardium, which compounds the likelihood of collateral injury. This review focuses on the basic principles of thermodynamics as they apply to energy delivery during radiofrequency ablation. These principles can be used to titrate energy delivery and plan ablative approaches in an effort to minimize complications during the procedure.

  13. Adoption d'innovations agricoles par le truchement de services ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'agriculture est le fer de lance de nombreuses économies en développement, mais la capacité des petits agriculteurs privés de ressources à adopter des innovations agricoles est freinée par le manque d'accès à des services financiers adéquats. Des experts internationaux estiment qu'il existe un manque à gagner ...

  14. Notre experience de la myelopathie par arthrose cervicale a Dakar ...

    African Journals Online (AJOL)

    ... (p=0,48 > 0,05) ne semblent pas influencer la récupération fonctionnelle post opératoire. Conclusion L'incidence de myélopathie par arthrose cervicale apparaît au Sénégal comme une pathologie sousestimée. La laminectomie décompressive sans instrumentation postérieure constitue notre choix thérapeutique majeur.

  15. Démarginalisation des travailleurs pauvres par le droit | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Démarginalisation des travailleurs pauvres par le droit. Cette subvention appuiera une étude approfondie de la situation, des revendications et des combats juridiques des travailleurs pauvres (plus particulièrement des femmes) membres de l'économie non structurée au Ghana, au Pérou et en Thaïlande. On aura recours à ...

  16. Inondations dans la banlieue de Dakar : vers une adaptation par ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Inondations dans la banlieue de Dakar : vers une adaptation par des améliorations du bâti, des infrastructures et de la gouvernance locale. La gestion des inondations représente un des défis majeurs du continent africain en regard des changements climatiques. Une urbanisation effrénée, un étalement urbain hors de ...

  17. Anesthesie topique par oxybuprocaine dans la chirurgie de cataracte

    African Journals Online (AJOL)

    Étude prospective portant sur 100 patients opérés pour cataracte simple stade I, II et III sous anesthésie topique par instillation de quatre gouttes d'Oxybuprocaïne 0.4% collyre, nous avons analysé les complications rencontrées et le confort des patients à l'aide de l'échelle visuelle analogique. La tolérance du patient durant ...

  18. La parálisis cerebral en el contexto escolar /

    OpenAIRE

    Rodríguez Gimeno, Ignacio

    2012-01-01

    Se analiza el concepto de parálisis cerebral, los diferentes tipos y sus características. También las adaptaciones que se deben realizar a nivel de centro, de aula, y a nivel individual para estos alumnos, conocer los diferentes sistemas alternativos y aumentativos de comunicación y aplicar las ayudas técnicas que precisa este alumnado

  19. Irrigation endoscopic assisted percutaneous pars repair: technical note.

    Science.gov (United States)

    Soliman, Hesham Magdi

    2016-10-01

    Spondylolysis is a common source of low back pain in children and adolescents. Despite the benign natural history of the pathology, however, it should be noted that as part of conservative management many young individuals are forced to discontinue their routine sports activities. In cases resistant to conservative management, direct repair of a pars defect is considered a safe and effective option in young adults with preserved discs. Recently, some reports of minimally invasive pars repair have been described, aiming at preservation of the paraspinal muscles and improvement of the postoperative course. The study aimed to present a new minimally invasive endoscopic technique for pars repair. This is a technical note. Seven consecutive patients complaining of back pain due to spondylolysis and resistant to conservative management were included. Outcome was assessed using the modified Macnab criteria, and bone union was assessed on postoperative radiographs. Two portals of 0.5 cm were used on each side, 1 cm lateral to the midline. One portal is used for the endoscope and the second for the surgical instruments. Following endoscopic debridement of the defect, the inferior portal was used for percutaneous placement of the Buck screw. There was no source for external funding for this study and no potential conflict of interest to disclose. Outcome was excellent in six cases and good in one case. All patients returned back to their normal level of activities. Complete radiographic union was seen in all patients. The mean period of postoperative hospital stay and follow-up was 8 hours and 21 months, respectively. The irrigation endoscopic technique has previously shown promising results in lumbar discectomy and laminectomy. Similar results were observed in the current study on the ability to achieve minimally invasive pars defect debridement and a smooth postoperative course. This is a pilot study and larger patient series and different surgeons' experience are

  20. Excision Les jeunes changent l'Afrique par les TIC

    International Development Research Centre (IDRC) Digital Library (Canada)

    Encadré 8 - Recherche sur les MGF : des concepts et méthodes à actualiser. 58. Encadré 9 - Faire comme les grands, quand on est jeune. 69. Encadré 10 - Etre un aîné, le rêve. 71. Encadré 11 - Le paradigme transdisciplinaire vu par les jeunes. 78. Encadré 12 - Citoyenneté au féminin/masculin. 83. Encadré 13 - Le projet, ...