243 resultados para Radiofrequency


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Companies that invest in current technologies maintain themselves updated, improve their business rules and anticipate themselves against rivals providing a better service to their customers. This project aims to develop an ERP - Enterprise Resource Planning module for Android which complements an existing manager system and, that attends the needs of a rental equipment business for civil building, i.e., it improves the communication channel company-client and betters the identification and control of products. During the developing of this project, it was necessary to study the company business rules, analyze the requirements and the appropriate technologies. This project was organized in two parts, contemplating e ach of these needs. It were implemented specific modules for generate budgets and pre-orders in the first part and, the use of radiofrequency tags in the second one. Thus, it was possible to assign mobility to company business rules so that a better rental service can be provided and the equipments can be better managed

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Inoue BH, dos Santos L, Pessoa TD, Antonio EL, Pacheco BPM, Savignano FA, Carraro-Lacroix LR, Tucci PJF, Malnic G, Girardi ACC. Increased NHE3 abundance and transport activity in renal proximal tubule of rats with heart failure. Am J Physiol Regul Integr Comp Physiol 302: R166-R174, 2012. First published October 26, 2011; doi:10.1152/ajpregu.00127.2011.-Heart failure (HF) is associated with a reduced effective circulating volume that drives sodium and water retention and extracellular volume expansion. We therefore hypothesized that Na(+)/H(+) exchanger isoform 3 (NHE3), the major apical transcellular pathway for sodium reabsorption in the proximal tubule, is upregulated in an experimental model of HF. HF was induced in male rats by left ventricle radiofrequency ablation. Sham-operated rats (sham) were used as controls. At 6 wk after surgery, HF rats exhibited cardiac dysfunction with a dramatic increase in left ventricular end-diastolic pressure. By means of stationary in vivo microperfusion and pH-dependent sodium uptake, we demonstrated that NHE3 transport activity was significantly higher in the proximal tubule of HF compared with sham rats. Increased NHE3 activity was paralleled by increased renal cortical NHE3 expression at both protein and mRNA levels. In addition, the baseline PKA-dependent NHE3 phosphorylation at serine 552 was reduced in renal cortical membranes of rats with HF. Collectively, these results suggest that NHE3 is upregulated in the proximal tubule of HF rats by transcriptional, translational, and posttranslational mechanisms. Enhanced NHE3-mediated sodium reabsorption in the proximal tubule may contribute to extracellular volume expansion and edema, the hallmark feature of HF. Moreover, our study emphasizes the importance of undertaking a cardiorenal approach to contain progression of cardiac disease.

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BACKGROUND: There is clinical evidence that very low and safe levels of amplitude-modulated electromagnetic fields administered via an intrabuccal spoon-shaped probe may elicit therapeutic responses in patients with cancer. However, there is no known mechanism explaining the anti-proliferative effect of very low intensity electromagnetic fields. METHODS: To understand the mechanism of this novel approach, hepatocellular carcinoma (HCC) cells were exposed to 27.12 MHz radiofrequency electromagnetic fields using in vitro exposure systems designed to replicate in vivo conditions. Cancer cells were exposed to tumour-specific modulation frequencies, previously identified by biofeedback methods in patients with a diagnosis of cancer. Control modulation frequencies consisted of randomly chosen modulation frequencies within the same 100 Hz-21 kHz range as cancer-specific frequencies. RESULTS: The growth of HCC and breast cancer cells was significantly decreased by HCC-specific and breast cancer-specific modulation frequencies, respectively. However, the same frequencies did not affect proliferation of nonmalignant hepatocytes or breast epithelial cells. Inhibition of HCC cell proliferation was associated with downregulation of XCL2 and PLP2. Furthermore, HCC-specific modulation frequencies disrupted the mitotic spindle. CONCLUSION: These findings uncover a novel mechanism controlling the growth of cancer cells at specific modulation frequencies without affecting normal tissues, which may have broad implications in oncology. British Journal of Cancer (2012) 106, 307-313. doi:10.1038/bjc.2011.523 www.bjcancer.com Published online 1 December 2011 (C) 2012 Cancer Research UK

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JUSTIFICATIVA E OBJETIVOS: A radiofrequência (RF) é uma corrente alternada com frequência de oscilação de 500.000 Hz, que tem sido usada com sucesso no tratamento de algumas morbidades que cursam com dor crônica. O objetivo deste relato de caso foi mostrar o uso bem sucedido da RF pulsátil do nervo sural para o tratamento de dor crônica no tornozelo. RELATO DO CASO: Paciente do sexo feminino, 60 anos, que há 5 anos apresentava dor em tornozelo direito, refratária ao tratamento com opioides, anti-inflamatório não esteroides (AINES), dipirona, antidepressivos e anticonvulsivantes, fisioterapia, infiltrações localizadas, acupuntura e palmilha. A paciente foi submetida a aplicação de RF pulsátil de nervo sural direito. O local da inserção da agulha foi na linha entre o tendão de Aquiles e maléolo lateral, região inicial de tendão de Aquiles e final dos músculos sóleo e gastrocnêmio. A estimulação sensitiva para identificação do nervo sural foi com 0,5 volts e 50 Hz. A corrente pulsátil foi aplicada durante 140 segundos com 45 volts com temperatura de até 42º C. Foram realizadas duas aplicações, ocorrendo melhora de cerca de 80% da dor, permitindo que a paciente pudesse deambular ou permanecer em pé, sem maiores dificuldades. CONCLUSÃO: A RF pulsátil do nervo sural pode ser uma opção para o controle das dores crônicas em tornozelo.

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Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is the periodic reduction or cessation of airflow during sleep. The syndrome is associated whit loud snoring, disrupted sleep and observed apnoeas. Surgery aims to alleviate symptoms of daytime sleepiness, improve quality of life and reduce the signs of sleep apnoea recordered by polysomnography. Surgical intervention for snoring and OSAHS includes several procedures, each designed to increase the patency of the upper airway. Procedures addressing nasal obstruction include septoplasty, turbinectomy, and radiofrequency ablation (RF) of the turbinates. Surgical procedures to reduce soft palate redundancy include uvulopalatopharyngoplasty with or without tonsillectomy, uvulopalatal flap, laser-assisted uvulopalatoplasty, and RF of the soft palate. More significant, however, particularly in cases of severe OSA, is hypopharyngeal or retrolingual obstruction related to an enlarged tongue, or more commonly due to maxillomandibular deficiency. Surgeries in these cases are aimed at reducing the bulk of the tongue base or providing more space for the tongue in the oropharynx so as to limit posterior collapse during sleep. These procedures include tongue-base suspension, genioglossal advancement, hyoid suspension, lingualplasty, and maxillomandibular advancement. We reviewed 269 patients undergoing to osas surgery at the ENT Department of Forlì Hospital in the last decade. Surgery was considered a success if the postoperative apnea/hypopnea index (AHI) was less than 20/h. According to the results, we have developed surgical decisional algorithms with the aims to optimize the success of these procedures by identifying proper candidates for surgery and the most appropriate surgical techniques. Although not without risks and not as predictable as positive airway pressure therapy, surgery remains an important treatment option for patients with obstructive sleep apnea (OSA), particularly for those who have failed or cannot tolerate positive airway pressure therapy. Successful surgery depends on proper patient selection, proper procedure selection, and experience of the surgeon. The intended purpose of medical algorithms is to improve and standardize decisions made in the delivery of medical care, assist in standardizing selection and application of treatment regimens, to reduce potential introduction of errors. Nasal Continuous Positive Airway Pressure (nCPAP) is the recommended therapy for patients with moderate to severe OSAS. Unfortunately this treatment is not accepted by some patient, appears to be poorly tolerated in a not neglible number of subjects, and the compliance may be critical, especially in the long term if correctly evaluated with interview as well with CPAP smart cards analysis. Among the alternative options in Literature, surgery is a long time honoured solution. However until now no clear scientific evidence exists that surgery can be considered a really effective option in OSAHS management. We have design a randomized prospective study comparing MMA and a ventilatory device (Autotitrating Positive Airways Pressure – APAP) in order to understand the real effectiveness of surgery in the management of moderate to severe OSAS. Fifty consecutive previously full informed patients suffering from severe OSAHS were enrolled and randomised into a conservative (APAP) or surgical (MMA) arm. Demographic, biometric, PSG and ESS profiles of the two group were statistically not significantly different. One year after surgery or continuous APAP treatment both groups showed a remarkable improvement of mean AHI and ESS; the degree of improvement was not statistically different. Provided the relatively small sample of studied subjects and the relatively short time of follow up, MMA proved to be in our adult and severe OSAHS patients group a valuable alternative therapeutical tool with a success rate not inferior to APAP.

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Nuclear Magnetic Resonance (NMR) is a branch of spectroscopy that is based on the fact that many atomic nuclei may be oriented by a strong magnetic field and will absorb radiofrequency radiation at characteristic frequencies. The parameters that can be measured on the resulting spectral lines (line positions, intensities, line widths, multiplicities and transients in time-dependent experi-ments) can be interpreted in terms of molecular structure, conformation, molecular motion and other rate processes. In this way, high resolution (HR) NMR allows performing qualitative and quantitative analysis of samples in solution, in order to determine the structure of molecules in solution and not only. In the past, high-field NMR spectroscopy has mainly concerned with the elucidation of chemical structure in solution, but today is emerging as a powerful exploratory tool for probing biochemical and physical processes. It represents a versatile tool for the analysis of foods. In literature many NMR studies have been reported on different type of food such as wine, olive oil, coffee, fruit juices, milk, meat, egg, starch granules, flour, etc using different NMR techniques. Traditionally, univariate analytical methods have been used to ex-plore spectroscopic data. This method is useful to measure or to se-lect a single descriptive variable from the whole spectrum and , at the end, only this variable is analyzed. This univariate methods ap-proach, applied to HR-NMR data, lead to different problems due especially to the complexity of an NMR spectrum. In fact, the lat-ter is composed of different signals belonging to different mole-cules, but it is also true that the same molecules can be represented by different signals, generally strongly correlated. The univariate methods, in this case, takes in account only one or a few variables, causing a loss of information. Thus, when dealing with complex samples like foodstuff, univariate analysis of spectra data results not enough powerful. Spectra need to be considered in their wholeness and, for analysing them, it must be taken in consideration the whole data matrix: chemometric methods are designed to treat such multivariate data. Multivariate data analysis is used for a number of distinct, differ-ent purposes and the aims can be divided into three main groups: • data description (explorative data structure modelling of any ge-neric n-dimensional data matrix, PCA for example); • regression and prediction (PLS); • classification and prediction of class belongings for new samples (LDA and PLS-DA and ECVA). The aim of this PhD thesis was to verify the possibility of identify-ing and classifying plants or foodstuffs, in different classes, based on the concerted variation in metabolite levels, detected by NMR spectra and using the multivariate data analysis as a tool to inter-pret NMR information. It is important to underline that the results obtained are useful to point out the metabolic consequences of a specific modification on foodstuffs, avoiding the use of a targeted analysis for the different metabolites. The data analysis is performed by applying chemomet-ric multivariate techniques to the NMR dataset of spectra acquired. The research work presented in this thesis is the result of a three years PhD study. This thesis reports the main results obtained from these two main activities: A1) Evaluation of a data pre-processing system in order to mini-mize unwanted sources of variations, due to different instrumental set up, manual spectra processing and to sample preparations arte-facts; A2) Application of multivariate chemiometric models in data analy-sis.

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Magnetic resonance imaging (MRI) is today precluded to patients bearing active implantable medical devices AIMDs). The great advantages related to this diagnostic modality, together with the increasing number of people benefiting from implantable devices, in particular pacemakers(PM)and carioverter/defibrillators (ICD), is prompting the scientific community the study the possibility to extend MRI also to implanted patients. The MRI induced specific absorption rate (SAR) and the consequent heating of biological tissues is one of the major concerns that makes patients bearing metallic structures contraindicated for MRI scans. To date, both in-vivo and in-vitro studies have demonstrated the potentially dangerous temperature increase caused by the radiofrequency (RF) field generated during MRI procedures in the tissues surrounding thin metallic implants. On the other side, the technical evolution of MRI scanners and of AIMDs together with published data on the lack of adverse events have reopened the interest in this field and suggest that, under given conditions, MRI can be safely performed also in implanted patients. With a better understanding of the hazards of performing MRI scans on implanted patients as well as the development of MRI safe devices, we may soon enter an era where the ability of this imaging modality may be more widely used to assist in the appropriate diagnosis of patients with devices. In this study both experimental measures and numerical analysis were performed. Aim of the study is to systematically investigate the effects of the MRI RF filed on implantable devices and to identify the elements that play a major role in the induced heating. Furthermore, we aimed at developing a realistic numerical model able to simulate the interactions between an RF coil for MRI and biological tissues implanted with a PM, and to predict the induced SAR as a function of the particular path of the PM lead. The methods developed and validated during the PhD program led to the design of an experimental framework for the accurate measure of PM lead heating induced by MRI systems. In addition, numerical models based on Finite-Differences Time-Domain (FDTD) simulations were validated to obtain a general tool for investigating the large number of parameters and factors involved in this complex phenomenon. The results obtained demonstrated that the MRI induced heating on metallic implants is a real risk that represents a contraindication in extending MRI scans also to patient bearing a PM, an ICD, or other thin metallic objects. On the other side, both experimental data and numerical results show that, under particular conditions, MRI procedures might be consider reasonably safe also for an implanted patient. The complexity and the large number of variables involved, make difficult to define a unique set of such conditions: when the benefits of a MRI investigation cannot be obtained using other imaging techniques, the possibility to perform the scan should not be immediately excluded, but some considerations are always needed.

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Die diffusionsgewichtete Magnetresonanztomographie (MRT) mit dem hyperpolarisierten Edelgas-Isotop 3He ist ein neues Verfahren zur Untersuchung von Erkrankungen der Atem-wege und der Lunge. Die Diffusionsbewegung der 3He-Atome in den Luftwegen der Lunge wird durch deren Wände begrenzt, wobei diese Einschränkung sowohl von den Dimensionen der Atemwege als auch von den Messparametern abhängt. Man misst daher einen scheinbaren Diffusionskoeffizienten (Apparent Diffusion Coefficient, ADC) der kleiner ist als der Diffusionskoeffizient bei freier Diffusion. Der ADC gestattet somit eine qualitative Abschät-zung der Größe der Luftwege und deren krankhafte Veränderung, ohne eine direkte Abbil-dung der Luftwege selbst. Eine dreidimensionale Abbildung der räumlichen Verteilung von Lungenschädigungen wird dadurch möglich. Ziel der vorliegenden Arbeit war es, ein tieferes physikalisch fundiertes Verständnis der 3He-Diffusionsmessung zu ermöglichen und die Methode der diffusionsgewichteten 3He-MRT hin zur Erfassung des kompletten 3He-Diffusionstensors weiterzuentwickeln. Dazu wurde systematisch im Rahmen von Phantom- und tierexperimentellen Studien sowie Patientenmes-sungen untersucht, inwieweit unterschiedliche Einflussfaktoren das Ergebnis der ADC-Messung beeinflussen. So konnte beispielsweise nachgewiesen werden, dass residuale Luftströmungen am Ende der Einatmung keinen Einfluss auf den ADC-Wert haben. Durch Simulationsrechnungen konnte gezeigt werden, in welchem Maße sich die durch den Anregungspuls hervorgerufene Abnah-me der Polarisation des 3He-Gases auf den gemessenen ADC-Wert auswirkt. In einer Studie an lungengesunden Probanden und Patienten konnte die Wiederholbarkeit der ADC-Messung untersucht werden, aber auch der Einfluss von Gravitationseffekten. Diese Ergebnisse ermöglichen genauere Angaben über systematische und statistische Messfehler, sowie über Grenzwerte zwischen normalem und krankhaft verändertem Lungengewebe. Im Rahmen dieser Arbeit wurde die bestehende diffusionsgewichtete Bildgebung methodisch zur Erfassung des kompletten Diffusionstensors von 3He in der Lunge weiterentwickelt. Dies war wichtig, da entlang der Luftwege weitestgehend freie Diffusion vorherrscht, während senkrecht zu den Luftwegen die Diffusion eingeschränkt ist. Mit Hilfe von Simulationsrech-nungen wurde der kritische Einfluss von Rauschen in den MRT-Bildern auf die Qualität der Messergebnisse untersucht. Diese neue Methodik wurde zunächst an einem Phantom beste-hend aus einem Bündel aus Glaskapillaren, deren innerer Durchmesser mit dem des mensch-lichen Azinus übereinstimmt, validiert. Es ergab sich eine gute Übereinstimmung zwischen theoretischen Berechnungen und experimentellen Ergebnissen. In ersten Messungen am Menschen konnten so unterschiedliche Anisotropiewerte zwischen lungengesunden Proban-den und Patienten gefunden werden. Es zeigte sich eine Tendenz zu isotroper Diffusion bei Patienten mit einem Lungenemphysem. Zusammenfassend tragen die Ergebnisse der vorliegenden Arbeit zu einem besseren Ver-ständnis der ADC-Messmethode bei und helfen zukünftige Studien aufgrund des tieferen Verständnisses der die 3He Messung beeinflussenden Faktoren besser zu planen.

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La chirurgia con ultrasuoni focalizzati guidati da MRI (MR-g-FUS) è un trattamento di minima invasività, guidato dal più sofisticato strumento di imaging a disposizione, che utilizza a scopo diagnostico e terapeutico forme di energia non ionizzante. Le sue caratteristiche portano a pensare un suo possibile e promettente utilizzo in numerose aree della patologia umana, in particolare scheletrica. L'osteoma osteoide affligge frequentemente pazienti di giovane età, è una patologia benigna, con origine ed evoluzione non chiare, e trova nella termoablazione con radiofrequenza continua sotto guida CT (CT-g-RFA) il suo trattamento di elezione. Questo lavoro ha valutato l’efficacia, gli effetti e la sicurezza del trattamento dell’osteoma osteoide con MR-g-FUS. Sono stati presi in considerazione pazienti arruolati per MR-g-FUS e, come gruppo di controllo, pazienti sottoposti a CT-g-RFA, che hanno raggiunto un follow-up minimo di 18 mesi (rispettivamente 6 e 24 pazienti). Due pazienti erano stati esclusi dal trattamento MR-g-FUS per claustrofobia (2/8). Tutti i trattamenti sono stati portati a termine con successo tecnico e clinico. Non sono state registrate complicanze o eventi avversi correlati all’anestesia o alle procedure di trattamento, e tutti i pazienti sono stati dimessi regolarmente dopo 12-24 ore. La durata media dei trattamenti di MR-g-FUS è stata di 40±21 min. Da valori di score VAS pre-trattamento oscillanti tra 6 e 10 (su scala 0-10), i trattamenti hanno condotto tutti i pazienti a VAS 0 (senza integrazioni farmacologiche). Nessun paziente ha manifestato segni di persistenza di malattia o di recidiva al follow-up. Nonostante la neurolisi e la risoluzione dei sintomi, la perfusione del nidus è stata ritrovata ancora presente in oltre il 70% dei casi sottoposti a MR-g-FUS (4/6 pazienti). I risultati derivati da un'analisi estesa a pazienti più recentemente arruolati confermano questi dati. Il trattamento con MR-g-FUS sembra essere efficace e sicuro nel risolvere la sintomatologia dell'osteoma osteoide.

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The primary goals of this study were to develop a cell-free in vitro assay for the assessment of nonthermal electromagnetic (EMF) bioeffects and to develop theoretical models in accord with current experimental observations. Based upon the hypothesis that EMF effects operate by modulating Ca2+/CaM binding, an in vitro nitric oxide (NO) synthesis assay was developed to assess the effects of a pulsed radiofrequency (PRF) signal used for treatment of postoperative pain and edema. No effects of PRF on NO synthesis were observed. Effects of PRF on Ca2+/CaM binding were also assessed using a Ca2+-selective electrode, also yielding no EMF Ca2+/CaM binding. However, a PRF effect was observed on the interaction of hemoglobin (Hb) with tetrahydrobiopterin, leading to the development of an in vitro Hb deoxygenation assay, showing a reduction in the rate of Hb deoxygenation for exposures to both PRF and a static magnetic field (SMF). Structural studies using pyranine fluorescence, Gd3+ vibronic sideband luminescence and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy were conducted in order to ascertain the mechanism of this EMF effect on Hb. Also, the effect of SMF on Hb oxygen saturation (SO2) was assessed under gas-controlled conditions. These studies showed no definitive changes in protein/solvation structure or SO2 under equilibrium conditions, suggesting the need for real-time instrumentation or other means of observing out-of-equilibrium Hb dynamics. Theoretical models were developed for EMF transduction, effects on ion binding, neuronal spike timing, and dynamics of Hb deoxygenation. The EMF sensitivity and simplicity of the Hb deoxygenation assay suggest a new tool to further establish basic biophysical EMF transduction mechanisms. If an EMF-induced increase in the rate of deoxygenation can be demonstrated in vivo, then enhancement of oxygen delivery may be a new therapeutic method by which clinically relevant EMF-mediated enhancement of growth and repair processes can occur.