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1.
Nature ; 551(7678): 67-70, 2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-29094694

RESUMO

The merger of two neutron stars is predicted to give rise to three major detectable phenomena: a short burst of γ-rays, a gravitational-wave signal, and a transient optical-near-infrared source powered by the synthesis of large amounts of very heavy elements via rapid neutron capture (the r-process). Such transients, named 'macronovae' or 'kilonovae', are believed to be centres of production of rare elements such as gold and platinum. The most compelling evidence so far for a kilonova was a very faint near-infrared rebrightening in the afterglow of a short γ-ray burst at redshift z = 0.356, although findings indicating bluer events have been reported. Here we report the spectral identification and describe the physical properties of a bright kilonova associated with the gravitational-wave source GW170817 and γ-ray burst GRB 170817A associated with a galaxy at a distance of 40 megaparsecs from Earth. Using a series of spectra from ground-based observatories covering the wavelength range from the ultraviolet to the near-infrared, we find that the kilonova is characterized by rapidly expanding ejecta with spectral features similar to those predicted by current models. The ejecta is optically thick early on, with a velocity of about 0.2 times light speed, and reaches a radius of about 50 astronomical units in only 1.5 days. As the ejecta expands, broad absorption-like lines appear on the spectral continuum, indicating atomic species produced by nucleosynthesis that occurs in the post-merger fast-moving dynamical ejecta and in two slower (0.05 times light speed) wind regions. Comparison with spectral models suggests that the merger ejected 0.03 to 0.05 solar masses of material, including high-opacity lanthanides.

2.
Sci Total Environ ; 648: 1210-1218, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30340266

RESUMO

Soil and water bioengineering is a technology that encourages scientists and practitioners to combine their knowledge and skills in the management of ecosystems with a common goal to maximize benefits to both man and the natural environment. It involves techniques that use plants as living building materials, for: (i) natural hazard control (e.g., soil erosion, torrential floods and landslides) and (ii) ecological restoration or nature-based re-introduction of species on degraded lands, river embankments, and disturbed environments. For a bioengineering project to be successful, engineers are required to highlight all the potential benefits and ecosystem services by documenting the technical, ecological, economic and social values. The novel approaches used by bioengineers raise questions for researchers and necessitate innovation from practitioners to design bioengineering concepts and techniques. Our objective in this paper, therefore, is to highlight the practice and research needs in soil and water bioengineering for reconciling natural hazard control and ecological restoration. Firstly, we review the definition and development of bioengineering technology, while stressing issues concerning the design, implementation, and monitoring of bioengineering actions. Secondly, we highlight the need to reconcile natural hazard control and ecological restoration by posing novel practice and research questions.


Assuntos
Conservação dos Recursos Naturais/métodos , Recuperação e Remediação Ambiental/métodos , Água Doce , Águas Salinas , Solo , Biodegradação Ambiental , Recuperação e Remediação Ambiental/instrumentação
3.
Transl Med UniSa ; 19: 109-115, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31360675

RESUMO

In February 2017, the "Programma Mattone Internazionale Salute" (ProMis), that is the Italian Program for Internationalization of Regional Health Systems of the Ministry of Health (MoH), presented the first version of its Position Paper on Health Tourism, which embeds a first shared approach to the recommendations expressed by the European Committee of Regions (CoR) on "Age-Friendly" tourism. The CoR stresses the importance of local and regional authorities in the coordination of multi-sectoral policies such as healthcare, social assistance, transport, urban planning and rural development in relation to the promotion of mobility, security, accessibility of services, including health care and social services. "Age-friendly" tourism is an example of an innovative tourist offer that strives to meet the health needs of the entire "traveling" population, with an integrated and cross-sector approach that involves various organizations operating in sectors such as healthcare, accessibility and transport. The aim of the workshop was to explore the interest of the stakeholders to participate in a systemic action in the field of "health" tourism, and to identify priority implementation areas that offer opportunities to take advantage of validated, innovative experiences that strengthen the accessibility to health and social services in regional, national and international contexts. This effort provides the opportunity to take advantage of aligning the European Structural and Investment Funds (ESIF) to the development of tourism, coherently with the needs and resources of local and regional health authorities.

4.
Lab Chip ; 7(8): 978-80, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17653337

RESUMO

We present an innovative thin layer chromatography plate, which integrates a linear array of amorphous silicon photodiodes for real-time qualitative and quantitative chromatographic analysis.

5.
Biosens Bioelectron ; 93: 315-321, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27567262

RESUMO

Lab-on-Chip are miniaturized systems able to perform biomolecular analysis in shorter time and with lower reagent consumption than a standard laboratory. Their miniaturization interferes with the multiple functions that the biochemical procedures require. In order to address this issue, our paper presents, for the first time, the integration on a single glass substrate of different thin film technologies in order to develop a multifunctional platform suitable for on-chip thermal treatments and on-chip detection of biomolecules. The proposed System on-Glass hosts thin metal films acting as heating sources; hydrogenated amorphous silicon diodes acting both as temperature sensors to monitor the temperature distribution and photosensors for the on-chip detection and a ground plane ensuring that the heater operation does not affect the photodiode currents. The sequence of the technological steps, the deposition temperatures of the thin films and the parameters of the photolithographic processes have been optimized in order to overcome all the issues of the technological integration. The device has been designed, fabricated and tested for the implementation of DNA amplification through the Polymerase Chain Reaction (PCR) with thermal cycling among three different temperatures on a single site. The glass has been connected to an electronic system that drives the heaters and controls the temperature and light sensors. It has been optically and thermally coupled with another glass hosting a microfluidic network made in polydimethylsiloxane that includes thermally actuated microvalves and a PCR process chamber. The successful DNA amplification has been verified off-chip by using a standard fluorometer.


Assuntos
Técnicas Biossensoriais , DNA/isolamento & purificação , Dispositivos Lab-On-A-Chip , DNA/química , Dimetilpolisiloxanos/química , Vidro/química , Reação em Cadeia da Polimerase , Silício/química
6.
Artigo em Inglês | MEDLINE | ID: mdl-18267614

RESUMO

The effect of trapped charges on the transverse acoustoelectric voltage (TAV) is investigated with the aim of extending the use of TAV measurements to the study of semiconductors with high defect density. Even if surface acoustic wave frequencies are as high as 100 MHz, charge trapping can influence the TAV. This has been verified by two particular experiments performed on Si/SiO(2) structures with high density of interface states. A theoretical model is proposed to explain the effects of the presence of deep-trap levels on the TAV. Novel boundary conditions for the acoustoelectric equations are introduced and an approximate solution for the TAV amplitude is presented. The model is used to define a novel procedure for the determination of interface-states' density using TAV versus bias voltage measurements.

8.
Appl Opt ; 36(13): 2751-4, 1997 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18253265

RESUMO

We report on thin-film photodetectors optimized for detecting the vacuum UV and rejection of the visible spectrum of electromagnetic radiation. The devices are made of hydrogenated amorphous silicon and silicon carbide on a glass substrate. At room temperature the photodetectors exhibit quantum efficiencies of 52% at lambda = 58.4 nm, 1% at lambda = 400 nm, and 0.1% at lambda = 650 nm. The response time for UV pulses from an N(2) laser gives signals of 6-mus full width at half-maximum and 500-ns rise time.

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