10,773 research outputs found
Evaluation of influenza vaccination services and users’ perception about its utility: a study in a community pharmacy in Lisbon, Portugal
Poster presented at the 25th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID). Copenhagen, Denmark, 25–28 April 201
Revealing hidden symmetries and gauge invariance of the massive Carroll-Field-Jackiw model
In this paper we have analyzed the improved version of the Gauge Unfixing
(GU) formalism of the massive Carroll-Field-Jackiw model, which breaks both the
Lorentz and gauge invariances, to disclose hidden symmetries to obtain gauge
invariance, the key stone of the Standard Model. In this process, as usual, we
have converted this second-class system into a first-class one and we have
obtained two gauge invariant models. We have verified that the Poisson brackets
involving the gauge invariant variables, obtained through the GU formalism,
coincide with the Dirac brackets between the original second-class variables of
the phase space. Finally, we have obtained two gauge invariant Lagrangians
where one of them represents the Stueckelberg form.Comment: revised version. To appear in Europhysics Letter
Optical microtopographic characterization of arqueological ceramics
Optics and optics and photonics based inspection tools and methods had expensively proven their invaluable importance in the preservation of cultural heritage and artwork. The non-invasive inspection of the 3D shape of objects and of the micro-relief structure of its surfaces can be of high importance in the characterization process required in most works of restoration or preservation of archeological artwork. In this communication we will report on a method of optical non-invasive microtopographic characterization of the surface of archeological ceramics. The samples used in this study are pre-historical and pre-colonial ceramics and pottery of tribes in the Paranaiba valley in Minas Gerais, Brazil. The pottery found is decorated with incisions with different geometric distributions and levels of complexity corresponding to two periods of indigenous Indian occupations: one from a period dated at 1,095 ± 186 years ago and another of the early nineteenth century dated between 212 ± 19 years and 190 ± 30 years ago seemingly corresponding to the occupation of the territory by southern Kayapós tribes.info:eu-repo/semantics/publishedVersio
3D characterization of arqueological ceramics
Optics and optics and photonics based inspection tools and methods had expensively proven their invaluable importance in the preservation of cultural heritage and artwork. The non-invasive inspection of the 3D shape of objects and of the micro-relief structure of its surfaces can be of high importance in the characterization process required in most works of restoration or preservation of archeological artwork. In this communication we will report on a method of optical non-invasive microtopographic characterization of the surface of archeological ceramics. The samples used in this study are pre-historical and pre-colonial ceramics and pottery of tribes in the Paranaiba valley in Minas Gerais, Brazil. The pottery found is decorated with incisions with different geometric distributions and levels of complexity corresponding to two periods of indigenous Indian occupations: one from a period dated at 1,095 ± 186 years ago and another of the early nineteenth century dated between 212 ± 19 years and 190 ± 30 years ago seemingly corresponding to the occupation of the territory by southern Kayapós tribes.info:eu-repo/semantics/publishedVersio
PET imaging using titanium-45: Could it be useful?
In the last decade a wider application of positron emission tomography (PET) as one of the most powerful medical imaging technologies was observed. This was largely due to the increased availability of equipment dedicated to production of radioisotopes, mainly due to the installation of low energy cyclotrons in hospitals, research institutes and pharmaceutical industries specialized in radiopharmaceutical production.info:eu-repo/semantics/publishedVersio
The use of radiolabeled nanoparticles for biomedical imaging
Introduction: In the last years, the practice of medicine is being changing with a special emphasis on the application of technological innovations where medical imaging modalities play an important role. Between several imaging modalities, Molecular Imaging (that is essentially based on Nuclear Medicine) is one of the most interesting solutions. On the other hand, assuming that nanoparticles are being studied as drug delivery systems, its application as vectors for radionuclide-based imaging is in a clear growing
Trends in income inequality: comparing the United States and Portugal
This article presents a comparative analysis of the United States and Portugal in terms of economic inequality from the early twentieth century to the present decade. We use different measures of inequality from several statistical sources. The article revolves around three complementary points. The first is a synchronic and diachronic analysis of economic inequalities in Portugal and the United States, the second is the issue of redistribution of income and the final analysis addresses the evolution of top incomes in both countries.info:eu-repo/semantics/acceptedVersio
Multimodal interaction with BIM data in immersive virtual reality
In this paper, we combine the potential brought by BIM standards to AEC
processes, with the recent trends and results taken from human-computer interaction (HCI). As a result, our system supports the visualization and interaction with 3D BIM models of buildings, at full scale in an immersive virtual reality (VR) environment, using natural and multimodal HCI, namely, combining gesture with speech. We´ve carried usability and user satisfaction evaluation with a panel of architects, engineers and architect students and our research shows that such an environment allows a deeper understanding of the work throughout the design process and improve the communication between AEC specialties, during design briefs. We have concluded also, that our technology offers great
benefits during all the stages of design, from the initial phase of conceptual design until the detailed stages up to the construction work. The practical experimentation of our in-house developed system, was possible by taking advantage of the virtual reality facilities of ISCTE-IUL, namely, its PocketCAVE lab.info:eu-repo/semantics/acceptedVersio
Tribological behavior of bioactive multi-material structures targeting orthopedic applications
Acknowledgments
This work was supported by Fundação para a Ciência e Tecnologia
(FCT), Portugal through the grants SFRH/BD/140191/2018, SFRH/BD/
128657/2017 and SFRH/BPD/112111/2015, the project PTDC/EMSTEC/
5422/2014 and also by project NORTE 01-0145_FEDER-000018.
Additionally, this work is supported by FCT with the reference project
UID/EEA/04436/2019.The following study proposes a multi-material solution in which Ti6Al4V cellular structures produced by Selective Laser Melting are impregnated with bioactive materials (hydroxyapatite or β-tricalcium phosphate) using press and sintering technique. To assess the tribological response of these structures, an alumina plate was used as a counterpart in a flat-on-flat reciprocating sliding test. Ti6Al4V cellular structures impregnated with bioactive materials displayed the highest wear resistance when compared with the unreinforced structures. Among the bioactive structures, Ti6Al4V cellular structures impregnated with βTCP were the ones with higher wear resistance, having the lowest weight loss. Hence, these structures are promising multifunctional solutions for load-bearing applications by gathering suitable mechanical properties (strength and stiffness); bioactive properties and in addition an improved wear performance.info:eu-repo/semantics/publishedVersio
Vascular liver anatomy and main variants: what the radiologist must know
Advances in surgical techniques are extremely demanding regarding the accuracy and level of detail expected for display of the vascular anatomy of the liver. Precise knowledge of the arterial, portal and hepatic vein territories are mandatory whenever a liver intervention is planned. Sectional anatomy can now be routinely performed on multidetector computed tomography (MDCT) with volumetric data and isotropic voxel display, by means of sub-millimetric slice thickness acquisition. The relevant vascular information can thus be gathered, reviewed and post-processed with unprecedented clarity, obviating the need for digital subtraction angiography. The scope of the present paper is to review the normal vascular liver anatomy, its most relevant variants including additional sources of vascular inflow. Apart from providing the surgeon with a detailed vascular and parenchymal roadmap knowledge of imaging findings may avoid potential confusion with pathologic processes
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