1,721,339 research outputs found
UTILIZZO DI STENT AUTOMODELLANTI ALLIUM NEL TRATTAMENTO DELLE STENOSI DELLE VIE URINARIE
No full textl'apparato urinario svolge nel suo complesso una funzione emuntoria; lo stent è uno strumento utilizzato per prevenire o risolvere rapidamente un'ostruzione delle alte vie urinarie. gli stent DJ sono la via convenzionale per risolvere le stenosi ureterali; lo stent allium è un endoprotesi autoespandibile
Analytical and numerical solution of the one dimensional steady state bioheat transfer equation
No full textThis work describes the comparison between the analytical and numerical solution of the one dimensional (1D) bioheat transfer equation in the steady state condition along the axis of a muscle slab. Aim of the work is the definition of an analytical framework for hyperthermia devices design and optimization. Oncological hyperthermia is a medical technique aimed at generating a temperature increase in the tumour region of the patient through the application of a single frequency electromagnetic field. The absorbed electromagnetic power per unit mass is defined as specific absorption rate (SAR). The SAR and the temperature distributions inside the human tissue are related by the bioheat transfer equation. In this study a plane wave at the working frequency of 434 MHz is considered as electromagnetic source, and the analytical solution is calculated solving the bioheat equation in case of an exponential approximation of the SAR distribution, in order to evaluate and predict the temperature distribution along the axis of the tissue. Results show an optimum agreement between the analytical and numerical temperature distributions
Muscle and fat equivalent mixtures at radiative hyperthermia frequencies
No full textThis work describes the realisation of two mixtures which can be used for the production of phantoms for oncological radiative hyperthermia. This therapeutic technique is based on the use of antennas for the application of electromagnetic fields on the body for the treatment of tumours. The efficacy of hyperthermia depends on the response of the biological tissues of the subject under the exposure of the field. Before the application on the patient, the technique must be validated on phantoms, made by mixtures of materials which mimic the dielectric properties of biological tissues. In this way, phantoms can represent the response of the human body to an external applied electromagnetic field and can substitute the patient for the validation procedures
La Modulazione dell’espressione del Tnf-Alfa e del suo recettore nella placca Psoriasica durante il trattamento con farmaci biologici
No full textContinuous detection of fluid leaks into the body by means of partially dissolvable antennas
No full textInternal fluid leaks in the human body can be caused by underlying medical disorders. Leakage may also be relevant to implanted stent grafts for the treatment of abdominal aneurysms. Indeed, blood may leak through the stent into the aneurysm sac with the risk of rupture due to increased internal pressure. As standard screenings cannot be performed frequently enough, this paper proposes wireless monitoring of fluid leaks into human body regions exploiting an implanted antenna partially coated by an engineered material and an auto-tuning IC in the UHF RFID band. The presence of fluid modifies the antenna impedance in a controlled way by the hydrolysis of the coating. An indication of this change can be obtained through radiofrequency interrogation from an external reader even when the antenna is implanted at 6 cm. Simulations and tests with a mock-up demonstrated the ability to distinguish the degradation of the bioresorbable coating. The sensor is responsive to up to 3.5 mm(3) of dissolved coating, with a sensitivity of more 10 units mm(3). Provided that the size of the coating has been properly engineered, the response of the sensor is robust w.r.t. the unpredictable interaction with the fluid
1450-57, Mariotto di Cristofano, Florence, Accademia (NH 103)
No full textDate 1450-57 Peintre Mariotto di Cristofano Dates/Activité 1393 – 1457 Appartenance géographique Florence Emplacement d’origine Doccia (Florence), Sant’Andrea Lieu de conservation Florence, Accademia Numéro de collection 8508 Restauration(s) 2004, 2006 (Veronesi Pesciolini) Dimensions (H x L en cm) 225 x 175 (ens.) Technique or et détrempe sur bois Forme polyptyque registre supérieur : Jésus parmi les docteurs, Dormition de la Vierge, Nativité registre inférieur : Fuite e..
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