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1.
Sensors (Basel) ; 19(22)2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31698742

RESUMO

There is an increasing need for safe and simple techniques for sensing devices and prostheses implanted inside the human body. Microwave wireless inspection may be an appropriate technique for it. The implanted device may have specific characteristics that allow to distinguish it from its environment. A new sensing technique based on the principle of differential resonance is proposed and its basic parameters are discussed. This technique allows to use the implant as a signal scattering device and to detect changes produced in the implant based on the corresponding change in its scattering signature. The technique is first tested with a canonic human phantom and then applied to a real in vivo clinical experiment to detect coronary stents implanted in swine animals.


Assuntos
Tecnologia/instrumentação , Animais , Humanos , Micro-Ondas , Imagens de Fantasmas , Próteses e Implantes , Stents , Suínos
2.
Regul Toxicol Pharmacol ; 88: 252-261, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28666961

RESUMO

Increasing numbers of biosimilar medicines are becoming available. The objective of this survey was to assess awareness of and attitudes to biosimilars amongst physicians (medical specialists and General Practitioners (GPs)) and community pharmacists in Ireland. Physicians were invited to complete an online questionnaire during April and May 2016. Community pharmacists received a postal questionnaire in August 2015. Responses from 102 medical specialists, 253 GPs and 125 community pharmacists were analysed. The majority of medical specialists (85%) and pharmacists (77%) claimed to be either very familiar or familiar with the term biosimilar, whereas many GPs (60%) were unable to define or had never heard of the term. One in five (21%) healthcare professionals responded that biosimilars were the same as generic medicines. The majority of medical specialists opposed pharmacist-led substitution of biological medicines but some thought it could be appropriate if agreed with the clinician in advance. Medical specialists who prescribe biosimilars (n = 43) were more likely to do so on treatment initiation (67%), than switch a patient from an originator medicine to a biosimilar (28%). The findings will aid the design of educational initiatives for healthcare professionals and highlight attitudes of healthcare professionals to biosimilars, so informing regulators, policy makers and industry.


Assuntos
Atitude do Pessoal de Saúde , Conscientização , Medicamentos Biossimilares/uso terapêutico , Farmacêuticos/psicologia , Médicos/psicologia , Clínicos Gerais/psicologia , Pesquisas sobre Atenção à Saúde , Humanos , Irlanda
3.
Sci Rep ; 10(1): 12325, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32704019

RESUMO

A thorough microwave response study of high temperature superconductors, considered as an alternative beam screen coating, has become integral in the design decisions for CERN's future research infrastructure. Here, we present the surface resistance [Formula: see text] of various [Formula: see text] (RE = rare earth) coated conductors available in large scale as a function of magnetic field in a broad temperature range measured by a Hakki-Coleman type resonator with resonant frequency [Formula: see text]. Analysis of the high frequency dissipation supported by DC transport characterization reveals the vortex dynamics in thick [Formula: see text] films. Determined microscopic vortex parameters span over a wide range of magnitudes and reflect the relevance of the superconducting layer's microstructure. We demonstrate that the depinning frequencies [Formula: see text] surpass [Formula: see text], which confirms the operation in high performing, low dissipation pinning regime at measurement conditions. Surface impedance extrapolation to FCC-hh conditions points towards a significant outperformance of copper by coated conductors in terms of surface resistance. The surface resistance margins would open up potential ways for a more efficient frontier circular collider.

4.
Med Phys ; 2018 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-29807391

RESUMO

PURPOSE: Colorectal cancer is highly preventable by detecting and removing polyps, which are the precursors. Currently, the most accurate test is colonoscopy, but still misses 22% of polyps due to visualization limitations. In this paper, we preliminary assess the potential of microwave imaging and dielectric properties (e.g., complex permittivity) as a complementary method for detecting polyps and cancer tissue in the colon. The dielectric properties of biological tissues have been used in a wide variety of applications, including safety assessment of wireless technologies and design of medical diagnostic or therapeutic techniques (microwave imaging, hyperthermia, and ablation). The main purpose of this work is to measure the complex permittivity of different types of colon polyps, cancer, and normal mucosa in ex vivo human samples to study if the dielectric properties are appropriate for classification purposes. METHODS: The complex permittivity of freshly excised healthy colon tissue, cancer, and histological samples of different types of polyps from 23 patients was characterized using an open-ended coaxial probe between 0.5 and 20 GHz. The obtained measurements were classified into five tissue groups before applying a data reduction step with a frequency dispersive single-pole Debye model. The classification was finally compared with pathological analysis of tissue samples, which is the gold standard. RESULTS: The complex permittivity progressively increases as the tissue degenerates from normal to cancer. When comparing to the gold-standard histological tissue analysis, the sensitivity and specificity of the proposed method is the following: 100% and 95% for cancer diagnosis; 91% and 62% for adenomas with high-grade dysplasia; 100% and 61% for adenomas with low-grade dysplasia; and 100% and 74% for hyperplastic polyps, respectively. In addition, complex permittivity measurements were independent of the lesion shape and size, which is also an interesting property comparing to current colonoscopy techniques. CONCLUSIONS: The contrast in complex permittivities between normal and abnormal colon tissues presented here for the first time demonstrate the potential of these measurements for tissue classification. It also opens the door to the development of a microwave endoscopic device to complement the outcomes of colonoscopy with functional tissue information.

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