1,646 research outputs found
Automated hippocampal segmentation in patients with epilepsy: Available free online
Hippocampal sclerosis, a common cause of refractory focal epilepsy, requires hippocampal volumetry for accurate diagnosis and surgical planning. Manual segmentation is time-consuming and subject to interrater/intrarater variability. Automated algorithms perform poorly in patients with temporal lobe epilepsy. We validate and make freely available online a novel automated method
The Importance of Design in the Development of a Portable and Modular Iot-Based Detection Device for Clinical Applications
The integration of human factors engineering methods within the medical device design and development process has been highlighted by international standards organizations. Such methods are contributing to the development of safer medical devices, more suitable to users' needs. Errors during device operation might hamper effective patient diagnosis and treatment, or eventually lead to injury or death. Thus, the designing process of a medical device is indeed crucial to user experience and safety operation. This paper presents a human-centred design analysis of a novel IoT-based screening prototype (iLoF) based on Artificial Intelligence algorithms built-in in a patented-photonics system developed by a deep tech startup. The influence of the design process during the development of the prototype was addressed, based on a human-centred design methodology and considering the device's application environment. iLoF's prototype on-field applicability was evaluated considering a single case-study carried out at one of the main hospitals in Portugal through interviews to ten healthcare professionals with high experience in laboratorial testing. A benchmark assessment and a comparison matrix along with the market products are also presented to fully understand the technology state and to find new solutions that can influence iLoF's product development. © Published under licence by IOP Publishing Ltd
Economic History and History of Economics: Complementary Approaches to Portuguese Economic Development
This chapter focuses on how the problems of economic development were addressed by the Portuguese historiography of the late nineteenth and twentieth centuries. The ensuing discussion benefits from the simultaneous consideration of two historiographical domains that complement each other: economic history and the history of economics. On the one hand, there are the authors and texts of economic history that seek to describe the facts and circumstances related to the functioning and dynamics of economic reality, for a given period or succession of periods, in order to establish evolutionary trends. On the other hand, there are the authors and texts of the history of economics that seek to adopt analytical forms (principles and laws) and doctrinal and programmatic frameworks (visions and ideologies) aimed at providing explanatory meaning to the observed economic changes, phenomena and regularities. A true understanding of the important issues pertaining to Portuguese economic development is to be found, however, in the intersection of these distinct but complementary historiographical perspectives.info:eu-repo/semantics/publishedVersio
black hole at N=2 supergravity
In this paper, we consider the charged non-extremal black hole at five
dimensional N = 2 supergravity. We study thermodynamics of AdS_{5} black hole
with three equal charges (q_{1} = q_{2} = q_{3} = q). We obtain Schrodinger
like equation and discuss the effective potential. Then, we consider the case
of the perturbed dilaton field background and find presence of odd coefficients
of the wave function. Also we find that the higher derivative corrections have
no effect on the first and second even coefficients of the wave function.Comment: 17 pages, 4 figures. Published versio
Fake supersymmetry versus Hamilton-Jacobi
We explain when the first-order Hamilton-Jacobi equations for black holes
(and domain walls) in (gauged) supergravity, reduce to the usual first-order
equations derived from a fake superpotential. This turns out to be equivalent
to the vanishing of a newly found constant of motion and we illustrate this
with various examples. We show that fake supersymmetry is a necessary condition
for having physically sensible extremal black hole solutions. We furthermore
observe that small black holes become scaling solutions near the horizon. When
combined with fake supersymmetry, this leads to a precise extension of the
attractor mechanism to small black holes: The attractor solution is such that
the scalars move on specific curves, determined by the black hole charges, that
are purely geodesic, although there is a non-zero potential.Comment: 20 pages, v2: Typos corrected, references adde
A de Sitter Hoedown
Rotating black holes in de Sitter space are known to have interesting limits
where the temperatures of the black hole and cosmological horizon are equal. We
give a complete description of the thermal phase structure of all allowed
rotating black hole configurations. Only one configuration, the rotating Nariai
limit, has the black hole and cosmological horizons both in thermal and
rotational equilibrium, in that both the temperatures and angular velocities of
the two horizons coincide. The thermal evolution of the spacetime is shown to
lead to the pure de Sitter spacetime, which is the most entropic configuration.
We then provide a comprehensive study of the wave equation for a massless
scalar in the rotating Nariai geometry. The absorption cross section at the
black hole horizon is computed and a condition is found for when the scattering
becomes superradiant. The boundary-to-boundary correlators at finite
temperature are computed at future infinity. The quasinormal modes are obtained
in explicit form. Finally, we obtain an expression for the expectation value of
the number of particles produced at future infinity starting from a vacuum
state with no incoming particles at past infinity. Some of our results are used
to provide further evidence for a recent holographic proposal between the
rotating Nariai geometry and a two-dimensional conformal field theory.Comment: 35 + 1 pages, 9 figures; v3: typos correcte
A matter of life and death: the Middle Neolithic population from Bom Santo Cave (Lisbon, Portugal)
The study of the Bom Santo Cave (central Portugal), a Neolithic cemetery, indicated a complex social, palaeoeconomic and population scenario. With isotope, aDNA and provenience analyses of raw materials coupled with stylistic variability of material culture items and
palaeogeographical data light is shed on the territory and social organization of a population dated to 3800–3400 cal BC, i.e. the middle phase of the period. Results indicate an itinerant farming, segmentary society, where exogamic practices were the norm and patrilocality probably predominated. Its lifeway may be that of the earliest megalithic builders of the region, but further research is needed to correctly evaluate the degree of participation in such phenomenon
Nanoanalytical analysis of bisphosphonate-driven alterations of microcalcifications using a 3D hydrogel system and in vivo mouse model
Vascular calcification predicts atherosclerotic plaque rupture and cardiovascular events. Retrospective studies of women taking bisphosphonates (BiPs), a proposed therapy for vascular calcification, showed that BiPs paradoxically increased morbidity in patients with prior acute cardiovascular events but decreased mortality in event-free patients. Calcifying extracellular vesicles (EVs), released by cells within atherosclerotic plaques, aggregate and nucleate calcification. We hypothesized that BiPs block EV aggregation and modify existing mineral growth, potentially altering microcalcification morphology and the risk of plaque rupture. Three-dimensional (3D) collagen hydrogels incubated with calcifying EVs were used to mimic fibrous cap calcification in vitro, while an ApoE-/- mouse was used as a model of atherosclerosis in vivo. EV aggregation and formation of stress-inducing microcalcifications was imaged via scanning electron microscopy (SEM) and atomic force microscopy (AFM). In both models, BiP (ibandronate) treatment resulted in time-dependent changes in microcalcification size and mineral morphology, dependent on whether BiP treatment was initiated before or after the expected onset of microcalcification formation. Following BiP treatment at any time, microcalcifications formed in vitro were predicted to have an associated threefold decrease in fibrous cap tensile stress compared to untreated controls, estimated using finite element analysis (FEA). These findings support our hypothesis that BiPs alter EV-driven calcification. The study also confirmed that our 3D hydrogel is a viable platform to study EV-mediated mineral nucleation and evaluate potential therapies for cardiovascular calcification
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