887 research outputs found
A methodological proposal and tool support for the HL7 standards compliance in the development of health information systems
Health information systems are increasingly complex, and their development is presented as a challenge for software development companies offering quality, maintainable and interoperable products. HL7 (Health level 7) International, an international non-profit organization, defines and maintains standards related to health information systems. However, the modelling languages proposed by HL7 are far removed from standard languages and widely known by software engineers. In these lines, NDT is a software development methodology that has a support tool called NDT-Suite and is based, on the one hand, on the paradigm of model-driven engineering and, on the other hand, in UML that is a widely recognized standard language. This paper proposes an extension of the NDT methodology called MoDHE (Model Driven Health Engineering) to offer software engineers a methodology capable of modelling health information systems conforming to HL7 using UML domain models
All-carbon multi-electrode array for real-time in vitro measurements of oxidizable neurotransmitters
We report on the ion beam fabrication of all-carbon multi electrode arrays
(MEAs) based on 16 graphitic micro-channels embedded in single-crystal diamond
(SCD) substrates. The fabricated SCD-MEAs are systematically employed for the
in vitro simultaneous amperometric detection of the secretory activity from
populations of chromaffin cells, demonstrating a new sensing approach with
respect to standard techniques. The biochemical stability and biocompatibility
of the SCD-based device combined with the parallel recording of
multi-electrodes array allow: i) a significant time saving in data collection
during drug screening and/or pharmacological tests over a large number of
cells, ii) the possibility of comparing altered cell functionality among cell
populations, and iii) the repeatition of acquisition runs over many cycles with
a fully non-toxic and chemically robust bio-sensitive substrate.Comment: 24 pages, 5 figure
Nanodiamonds-induced effects on neuronal firing of mouse hippocampal microcircuits
Fluorescent nanodiamonds (FND) are carbon-based nanomaterials that can
efficiently incorporate optically active photoluminescent centers such as the
nitrogen-vacancy complex, thus making them promising candidates as optical
biolabels and drug-delivery agents. FNDs exhibit bright fluorescence without
photobleaching combined with high uptake rate and low cytotoxicity. Focusing on
FNDs interference with neuronal function, here we examined their effect on
cultured hippocampal neurons, monitoring the whole network development as well
as the electrophysiological properties of single neurons. We observed that FNDs
drastically decreased the frequency of inhibitory (from 1.81 Hz to 0.86 Hz) and
excitatory (from 1.61 Hz to 0.68 Hz) miniature postsynaptic currents, and
consistently reduced action potential (AP) firing frequency (by 36%), as
measured by microelectrode arrays. On the contrary, bursts synchronization was
preserved, as well as the amplitude of spontaneous inhibitory and excitatory
events. Current-clamp recordings revealed that the ratio of neurons responding
with AP trains of high-frequency (fast-spiking) versus neurons responding with
trains of low-frequency (slow-spiking) was unaltered, suggesting that FNDs
exerted a comparable action on neuronal subpopulations. At the single cell
level, rapid onset of the somatic AP ("kink") was drastically reduced in
FND-treated neurons, suggesting a reduced contribution of axonal and dendritic
components while preserving neuronal excitability.Comment: 34 pages, 9 figure
Micro-beam and pulsed laser beam techniques for the micro-fabrication of diamond surface and bulk structures
Micro-fabrication in diamond is involved in a wide set of emerging
technologies, exploiting the exceptional characteristics of diamond for
application in bio-physics, photonics, radiation detection. Micro ion-beam
irradiation and pulsed laser irradiation are complementary techniques, which
permit the implementation of complex geometries, by modification and
functionalization of surface and/or bulk material, modifying the optical,
electrical and mechanical characteristics of the material. In this article we
summarize the work done in Florence (Italy) concerning ion beam and pulsed
laser beam micro-fabrication in diamond.Comment: 14 pages, 5 figure
Polarized micro-Raman studies of femtosecond laser written stress-induced optical waveguides in diamond
Understanding the physical mechanisms of the refractive index modulation
induced by femtosecond laser writing is crucial for tailoring the properties of
the resulting optical waveguides. In this work we apply polarized Raman
spectroscopy to study the origin of stress-induced waveguides in diamond,
produced by femtosecond laser writing. The change in the refractive index
induced by the femtosecond laser in the crystal is derived from the measured
stress in the waveguides. The results help to explain the waveguide
polarization sensitive guiding mechanism, as well as providing a technique for
their optimization.Comment: 5 pages, 4 figure
Photo-physical properties of He-related color centers in diamond
Diamond is a promising platform for the development of technological
applications in quantum optics and photonics. The quest for color centers with
optimal photo-physical properties has led in recent years to the search for
novel impurity-related defects in this material. Here, we report on a
systematic investigation of the photo-physical properties of two He-related
(HR) emission lines at 535 nm and 560 nm created in three different diamond
substrates upon implantation with 1.3 MeV He+ ions and subsequent annealing.
The spectral features of the HR centers were studied in an "optical grade"
diamond substrate as a function of several physical parameters, namely the
measurement temperature, the excitation wavelength and the intensity of
external electric fields. The emission lifetimes of the 535 nm and 560 nm lines
were also measured by means of time-gated photoluminescence measurements,
yielding characteristic decay times of (29 +- 5) ns and (106 +- 10) ns,
respectively. The Stark shifting of the HR centers under the application of an
external electrical field was observed in a CVD diamond film equipped with
buried graphitic electrodes, suggesting a lack of inversion symmetry in the
defects' structure. Furthermore, the photoluminescence mapping under 405 nm
excitation of a "detector grade" diamond sample implanted at a 1x1010 cm-2 He+
ion fluence enabled to identify the spectral features of both the HR emission
lines from the same localized optical spots. The reported results provide a
first insight towards the understanding of the structure of He-related defects
in diamond and their possible utilization in practical applicationsComment: 9 pages, 3 figure
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