Search results for "Radio"
showing 10 items of 8895 documents
3C 279 Event Horizon Telescope imaging
2020
3C 279 is an archetypal blazar with a prominent radio jet that show broadband flux density variability across the entire electromagnetic spectrum. We use an ultra-high angular resolution technique - global Very Long Baseline Interferometry (VLBI) at 1.3mm (230GHz) - to resolve the innermost jet of 3C 279 in order to study its fine-scale morphology close to the jet base where highly variable gamma-ray emission is thought to originate, according to various models. The source was observed during four days in April 2017 with the Event Horizon Telescope (EHT) at 230 GHz, including the phased Atacama Large Millimeter/submillimeter Array (ALMA), at an angular resolution of ~20uarcsec (at a redshif…
Clinical justification of dental radiology in adult patients: A review of the literature
2007
Although the radiological doses used by dentists are low individually, patients are often exposured to many repeat dental radiographic examinations. The ‘routine’ use of dental radiography, such as screening of all patients using dental panoramic radiography (DPRs) or a random decision to take a dental radiograph, will inevitable lead to unnecessary patient exposure. The use of Radiographic Referral Criteria has now become a legal requirement for all practitioners following the adoption of European Legislation. All exposures to x-rays should be clinically justified and each exposure should be expected to give the patient a positive net benefit. Recently the European Commission has published…
Practical, Not Radical : Examining Innovative Learning Culture in a Public Service Media Organization
2022
Recent scholarship has argued for media organizations’ need to radically innovate to ensure their survival in the future. This study deploys the innovative learning culture (ILC) framework to qualitatively study innovation and learning in a legacy public service media organization. While innovation and learning are linked, the learning processes of professional journalists have received only little attention. Through an analysis of a development network operating in a public service media organization, we identify characteristics of ILC in the network and how those characteristics manifest in practice, as well as examine contextual factors that shape ILC. Our findings indicate that innovati…
Radioluminescence Response of Ce-, Cu-, and Gd-Doped Silica Glasses for Dosimetry of Pulsed Electron Beams
2021
Radiation-induced emission of doped sol-gel silica glass samples was investigated under a pulsed 20-MeV electron beam. The studied samples were drawn rods doped with cerium, copper, or gadolinium ions, which were connected to multimode pure-silica core fibers to transport the induced luminescence from the irradiation area to a signal readout system. The luminescence pulses in the samples induced by the electron bunches were studied as a function of deposited dose per electron bunch. All the investigated samples were found to have a linear response in terms of luminescence as a function of electron bunch sizes between 10−5 Gy/bunch and 1.5×10−2 Gy/bunch. The presented results show that these…
Properties of Gd-Doped Sol-Gel Silica Glass Radioluminescence under Electron Beams
2022
International audience; The radiation-induced emission (RIE) of Gd3+-doped sol–gel silica glass has been shown to have suitable properties for use in the dosimetry of beams of ionizing radiation in applications such as radiotherapy. Linear electron accelerators are commonly used as clinical radiotherapy beams, and in this paper, the RIE properties were investigated under electron irradiation. A monochromator setup was used to investigate the light properties in selected narrow wavelength regions, and a spectrometer setup was used to measure the optical emission spectra in various test configurations. The RIE output as a function of depth in acrylic was measured and compared with a reference…
Dental implants rehabilitation in a patient with head and neck radiotherapy for osteosarcoma in the jaw. A clinical case report
2021
A 52-year-old female patient with a diagnostic of osteosarcoma in the mandible, in which it was necessary a reconstruction with a microvascularized osteomyocutaneous fibula bone. Coadjuvant chemotherapy was scheduled. Two years later, 4 osseointegrated implants (OII) were placed in the fibula a 2 OII in the right mandible, using a splint guided surgery. The final prosthodontic consisted in a metal ceramic restoration using CAD/ CAM technology. Key words:Oral rehabilitation, oral cancer, head and neck radiotherapy, oral oncology.
Botulinum Toxin A for Oral Cavity Cancer Patients: In Microsurgical Patients BTX Injections in Major Salivary Glands Temporarily Reduce Salivary Prod…
2012
Abstract: In patients suffering from oral cavity cancer surgical treatment is complex because it is necessary to remove carcinoma and lymph node metastasis (through a radical unilateral or bilateral neck dissection) and to reconstruct the affected area by means of free flaps. The saliva stagnation in the post-operative period is a risk factor with regard to local complications. Minor complications related to saliva stagnation (such as tissue maceration and wound dehiscence) could become major complications compromising the surgery or the reconstructive outcome. In fact the formation of oro-cutaneous fistula may cause infection, failure of the free flap, or the patient’s death with carotid b…
Ortopantomogrāfijas izmeklējuma attēlu kvalitātes kritēriju izvērtējums
2017
Bakalaura darba temats ir „Ortopantomogrāfijas izmeklējuma attēlu kvalitātes kritēriju izvērtējums”. Darba mērķis ir noskaidrot ortopantomogrāfijas izmeklējuma attēlu atbilstību standarta kvalitātes kritērijiem. Pētījuma rezultāti rāda, ka visbiežāk izmeklējumu attēlos tiek novērota zobu metāla restaurāciju radīti artefakti, bet otrs visbiežākais kvalitātes ietekmējošais faktors ir pacientu kustību izraisīti artefakti, savukārt visretāk tiek novēroti neveiksmīgi izvēlēti ekspozīcijas parametri. Darbs sastāv no divām daļām – teorētiskās un praktiskās. Teorētiskajā daļā tiek iekļauta zinātniskās literatūras medicīnā par zobu un žokļu anatomiskjām strukūrām, ortopantomopāfijas izmeklējuma meto…
Association between radiography-based subchondral bone structure and MRI-based cartilage composition in postmenopausal women with mild osteoarthritis
2017
Abstract Objective: Our aim was to investigate the relation between radiograph-based subchondral bone structure and cartilage composition assessed with delayed gadolinium enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T₂ relaxation time. Design: Ninety-three postmenopausal women (Kellgren–Lawrence grade 0: n = 13, 1: n = 26, 2: n = 54) were included. Radiograph-based bone structure was assessed using entropy of the Laplacian-based image (ELap) and local binary patterns (ELBP), homogeneity indices of the local angles (HIAngles,mean, HIAngles,Perp, HIAngles,Paral), and horizontal (FDHor) and vertical fractal dimensions (FDVer). Mean dGEMRIC index and T₂ relaxation time of tibi…