2,151 research outputs found
Stakeholder perspectives on the development of a virtual clinic for diabetes care : qualitative study
Background: The development of the Internet has created new opportunities for health care provision, including its use as a
tool to aid the self-management of chronic conditions. We studied stakeholder reactions to an Internet-based “virtual clinic,”
which would allow people with diabetes to communicate with their health care providers, find information about their condition,
and share information and support with other users.
Objective: The aim of the study was to present the results of a detailed consultation with a variety of stakeholder groups in
order to identify what they regard as the desirable, important, and feasible characteristics of an Internet-based intervention to aid
diabetes self-management.
Methods: Three focus groups were conducted with 12 people with type 1 diabetes who used insulin pumps. Participants were
recruited through a local diabetes clinic. One-on-one interviews were conducted with 5 health care professionals from the same
clinic (2 doctors, 2 nurses, 1 dietitian) and with 1 representative of an insulin pump company. We gathered patient consensus via
email on the important and useful features of Internet-based systems used for other chronic conditions (asthma, epilepsy, myalgic
encephalopathy, mental health problems). A workshop to gather expert consensus on the use of information technology to improve
the care of young people with diabetes was organized.
Results: Stakeholder groups identified the following important characteristics of an Internet-based virtual clinic: being grounded
on personal needs rather than only providing general information; having the facility to communicate with, and learn from, peers;
providing information on the latest developments and news in diabetes; being quick and easy to use. This paper discusses these
characteristics in light of a review of the relevant literature. The development of a virtual clinic for diabetes that embodies these
principles, and that is based on self-efficacy theory, is described.
Conclusions: Involvement of stakeholders is vital early in the development of a complex intervention. Stakeholders have clear
and relevant views on what a virtual clinic system should provide, and these views can be captured and synthesized with relative
ease. This work has led to the design of a system that is able to meet user needs and is currently being evaluated in a pilot study
Interactions between sub-10 nm iron and cerium oxide nanoparticles and 3T3 fibroblasts : the role of the coating and aggregation state
Recent nanotoxicity studies revealed that the physico-chemical
characteristics of engineered nanomaterials play an important role in the
interactions with living cells. Here, we report on the toxicity and uptake of
the cerium and iron oxide sub-10 nm nanoparticles by NIH/3T3 mouse fibroblasts.
Coating strategies include low-molecular weight ligands (citric acid) and
polymers (poly(acrylic acid), MW = 2000 g mol-1). Electrostatically adsorbed on
the surfaces, the organic moieties provide a negatively charged coating in
physiological conditions. We find that most particles were biocompatible, as
exposed cells remained 100% viable relative to controls. Only the bare and the
citrate-coated nanoceria exhibit a slight decrease of the mitochondrial
activity for cerium concentrations above 5 mM (equivalent to 0.8 g L-1). We
also observe that the citrate-coated particles are internalized by the cells in
large amounts, typically 250 pg per cell after a 24 h incubation for iron
oxide. In contrast, the polymer-coated particles are taken up at much lower
rates (< 30 pg per cell). The strong uptake shown by the citrate-coated
particles is related to the destabilization of the dispersions in the cell
culture medium and their sedimentation down to the cell membranes. In
conclusion, we show that the uptake of nanomaterials by living cells depends on
the coating of the particles and on its ability to preserve the colloidal
nature of the dispersions.Comment: 9 figures, 2 table
Relaxation and derelaxation of pure and hydrogenated amorphous silicon during thermal annealing experiments
The structural relaxation of pure amorphous silicon (a-Si) and hydrogenated
amorphous silicon (a-Si:H) materials, that occurs during thermal annealing
experiments, has been analysed by Raman spectroscopy and differential scanning
calorimetry. Unlike a-Si, the heat evolved from a-Si:H cannot be explained by
relaxation of the Si-Si network strain, but it reveals a derelaxation of the
bond angle strain. Since the state of relaxation after annealing is very
similar for pure and hydrogenated materials, our results give strong
experimental support to the predicted configurational gap between a-Si and
crystalline silicon.Comment: 15 pages, 3 figures, 1 table to be published in Applied Physics
Letter
SIMSAFADIM-CLASTIC : a new approach to mathematical 3D forward simulation modelling for terrigenous and carbonate marine sedimentation
Most sedimentary modelling programs developed in recent years focus on either terrigenous or carbonate marine sedimentation. Nevertheless, only a few programs have attempted to consider mixed terrigenous-carbonate sedimentation, and most of these are two-dimensional, which is a major restriction since geological processes take place in 3D. This paper presents the basic concepts of a new 3D mathematical forward simulation model for clastic sediments, which was developed from SIMSAFADIM, a previous 3D carbonate sedimentation model. The new extended model, SIMSAFADIM-CLASTIC, simulates processes of autochthonous marine carbonate production and accumulation, together with clastic transport and sedimentation in three dimensions of both carbonate and terrigenous sediments. Other models and modelling strategies may also provide realistic and efficient tools for prediction of stratigraphic architecture and facies distribution of sedimentary deposits. However, SIMSAFADIM-CLASTIC becomes an innovative model that attempts to simulate different sediment types using a process-based approach, therefore being a useful tool for 3D prediction of stratigraphic architecture and facies distribution in sedimentary basins. This model is applied to the neogene Vallès-Penedès half-graben (western Mediterranean, NE Spain) to show the capacity of the program when applied to a realistic geologic situation involving interactions between terrigenous clastics and carbonate sediments
Surfactant effects in monodisperse magnetite nanoparticles of controlled size
Monodisperse magnetite Fe3O4 nanoparticles of controlled size within 6 and 20
nm in diameter were synthesized by thermal decomposition of an iron organic
precursor in an organic medium. Particles were coated with oleic acid. For all
samples studied, saturation magnetization Ms reaches the expected value for
bulk magnetite, in contrast to results in small particle systems for which Ms
is usually much smaller due to surface spin disorder. The coercive field for
the 6 nm particles is also similar to that of bulk magnetite. Both results
suggest that the oleic acid molecules covalently bonded to the nanoparticle
surface yield a strong reduction in the surface spin disorder. However,
although the saturated state may be similar, the approach to saturation is
different and, in particular, the high-field differential susceptibility is one
order of magnitude larger than in bulk materials. The relevance of these
results in biomedical applications is discussed.Comment: 3 pages, 3 figures. Presented at JEMS 2006 (San Sebastian, Spain).
Submitted to JMM
The structure of the South-Central-Pyrenean fold and thrust belt as constrained by subsurface data
The interpretation of the available seismic lines of the South-Central-Pyrenean fold and thrust belt, conveniently tied with the exploration wells, define the main structural features of this realm of the Pyrenees. In particular, they define the geometry and areal extension of the autochthonous foreland underneath the sole thrust. The mapping ofseveral selected structural lines brings constraints for the structural interpretation of the South-Central Pyrenees, including the cut-off lines between selected stratigraphic horizons of the autochthonous foreland and the branch line between basement-involved thrust sheets and the sole thrust. The thrust salient which characterizes at surface the geometry of the South-Pyrenean fold and thrust belt contrasts with the linear trend of these structural lines at subsurface. This salient has been the result of a secondary progressive curvature developed since Middle Eocene times by thrust displacement gradients during verthrusting of the South-Pyrenean thrust sheets above a Paleogene autochthonous sequence. Displacement gradients resulted from the uneven distribution of weak salt layers, mostly the Triassic and the Upper Eocene ones. The minimum amount of South-directed displacement from early MiddleEocene times to Late Oligocene is 52km, which would be significantly higher if internal shortening by folding and cleavage/fracture development as well as hanging-wall erosion is added
Concurrent infall of satellites: Collective effects changing the overall picture
A variety of new physical processes have proven to play an important role in
orbital decay of a satellite galaxy embedded inside a dark matter halo but this
is not fully understood. Our goal is to assess if the orbital history of a
satellite remains unchanged during a concurrent sinking. For this purpose we
analyze the impact that the internal structure of the satellites and their
spatial distribution inside the host halo may have on the concurrent sinking
process due to both mass loss and the combined effect of self-friction, which
have not been studied before for concurrent sinking. We set up a set of N-body
simulations that include multiple satellites, sinking simultaneously in a host
halo and we compare them with models including a single satellite. The main
result of our work is that the satellite's accretion history differs from the
classical isolated view when we consider the collective effects. The accretion
history of each satellite strongly depends on the initial configuration, the
number of satellites in the halo at the time of infall and the internal
properties of each satellite. We observe that compact satellites in a flat
configuration fall slower than extended satellites that have lost mass, showing
a non-reported behavior of self-friction. We find that such effects are
maximized when satellites are located in a flat configuration. We show that in
a flat configuration similar to the Vast Polar Structure, deviations in the
apocenters can be of about 30% with respect to the isolated case, and up to 50%
on the eccentricities. We conclude that ignoring the collective effects
produced by the concurrent sinking of satellite galaxies may lead to large
errors in the determination of the merger progenitors properties, making it
considerably more challenging to trace back the accretion event. Timing
constrains on host density profile may be modified by the effects discussed
here.Comment: A&A, Forthcoming article Received: 29 March 2022 / Accepted: 26
September 2022 6 pages, 6 figure
Raman microprobe characterization of electrodeposited S-rich CuIn(S,Se)2 for photovoltaic applications: Microstructural analysis
This article reports a detailed Raman scattering and microstructural characterization of S-rich CuIn(S,Se)2 absorbers produced by electrodeposition of nanocrystalline CuInSe2 precursors and subsequent reactive annealing under sulfurizing conditions. Surface and in-depth resolved Raman microprobe measurements have been correlated with the analysis of the layers by optical and scanning electron microscopy, x-ray diffraction, and in-depth Auger electron spectroscopy. This has allowed corroboration of the high crystalline quality of the sulfurized layers. The sulfurizing conditions used also lead to the formation of a relatively thick MoS2 intermediate layer between the absorber and the Mo back contact. The analysis of the absorbers has also allowed identification of the presence of In-rich secondary phases, which are likely related to the coexistence in the electrodeposited precursors of ordered vacancy compound domains with the main chalcopyrite phase, in spite of the Cu-rich conditions used in the growth. This points out the higher complexity of the electrodeposition and sulfurization processes in relation to those based in vacuum deposition techniques
Weld kinematics of syn-rift salt during basement-involved extension and subsequent inversion: Results from analog models
Scaled analog models based on extensional basins with synrift salt show how basement topography exerts a control factor on weld kinematics during the extension and inversion phases. In the case of basement-involved extension, syn-rift salt thickness differences may lead to variable degrees of extensional decoupling between basement topography and overburden, which in turn have a strong impact on the development of salt structures. With ongoing extension and after welding, the basin kinematics evolves toward a coupled deformation style. The basin architecture of our experimental results record the halokinetic activity related to growing diapirs and the timing of weld formationduring extension. Moreover, the structures that result from anysubsequent inversion of these basins strongly depends on the inherited welds and salt structures. While those basins are uplifted,the main contractional deformation during inversion is absorbed by the pre-existing salt structures, whose are squeezed developing secondary welds that often evolve into thrust welds. The analysis of our analog models shows that shortening of diapirs is favored by: i) basement topography changes that induce reactivation of primary welds as thrust welds; ii) reactivation of the salt unit as a contractional detachment and iii) synkinematic sedimentation during basin inversion. Finally, in this article, we also compare two natural examples from the southern North Sea that highlight deformation patterns very similar to those observed in our analog models
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