1,160 research outputs found
Lagrangian Coherent Structures as a new frame to investigate the particle transport in highly chaotic magnetic systems
Ocular Refraction at Birth and Its Development During the First Year of Life in a Large Cohort of Babies in a Single Center in Northern Italy
The purpose of this study was to investigate refraction at birth and during the first year of life in a large cohort of babies born in a single center in Northern Italy. We also aimed to analyze refractive errors in relation to the gestational age at birth. An observational ophthalmological assessment was performed within 24 h of birth on 12,427 newborns. Refraction was examined using streak retinoscopy after the administration of tropicamide (1%). Values in the range of between +0.50 †D †+4.00 were defined as physiological refraction at birth. Newborns with refraction values outside of the physiological range were followed up during the first year of life. Comparative analyses were conducted in a subgroup of babies with known gestational ages. The following distribution of refraction at birth was recorded: 88.03% of the babies had physiological refraction, 5.03% had moderate hyperopia, 2.14% had severe hyperopia, 3.4%, had emmetropia, 0.45%, had myopia, 0.94% had astigmatism, and 0.01% had anisometropia. By the end of the first year of life, we observed reductions in hyperopia and astigmatism, and stabilization of myopia. Preterm babies had a four-fold higher risk of congenital myopia and a three-fold higher risk of congenital emmetropia as compared to term babies. Refraction profiles obtained at birth changed during the first year of life, leading to a normalization of the refraction values. Gestational age at birth affected the incidence of refractive errors and amblyopia
Widening use of dexamethasone implant for the treatment of macular edema
Sustained-release intravitreal 0.7 mg dexamethasone (DEX) implant is approved in Europe for the treatment of macular edema related to diabetic retinopathy, branch retinal vein occlusion, central retinal vein occlusion, and non-infectious uveitis. The implant is formulated in a biodegradable copolymer to release the active ingredient within the vitreous chamber for up to 6 months after an intravitreal injection, allowing a prolonged interval of efficacy between injections with a good safety profile. Various other ocular pathologies with inflammatory etioÂpathogeneses associated with macular edema have been treated by DEX implant, including neovascular age-related macular degeneration, IrvineâGass syndrome, vasoproliferative retinal tumors, retinal telangiectasia, Coatsâ disease, radiation maculopathy, retinitis pigmentosa, and macular edema secondary to scleral buckling and pars plana vitrectomy. We undertook a review to provide a comprehensive collection of all of the diseases that benefit from the use of the sustained-release DEX implant, alone or in combination with concomitant therapies. A MEDLINE search revealed lack of randomized controlled trials related to these indications. Therefore we included and analyzed all available studies (retrospective and prospective, comÂparative and non-comparative, randomized and nonrandomized, single center and multicenter, and case report). There are reports in the literature of the use of DEX implant across a range of macular edema-related pathologies, with their clinical experience supporting the use of DEX implant on a case-by-case basis with the aim of improving patient outcomes in many macular pathologies. As many of the reported macular pathologies are difficult to treat, a new treatÂment option that has a beneficial influence on the clinical course of the disease may be useful in clinical practice
On the use of the transfer matrix method to evaluate sound insulation in complex building partitions
The transfer matrix method (TMM) represents a powerful tool to investigate wave propagation through different media, which could be particularly suitable to compute sound transmission through building partitions. Even though layered structures can be easily modelled by using the TMM approach, it is not always easy to determine the elastic properties of each layer the partitions is made of. Traditional partitions, generally made in masonry with clay or concrete bricks coupled together with mortar joints, are inhomogeneous and anisotropic structures whose elastic properties are difficult to measure. Again, cross-laminated timber (CLT) panels, due to their peculiar substructure, might exhibit a highly orthotropic behaviour. A homogenisation approach, based on a minimization algorithm of the transmission loss (TL) of the bare structure, is proposed in this paper. It allows to consider inhomogeneous or anisotropic materials as an equivalent elastic solid described by effective frequency-depended elastic properties. The reliability of this approach is validated by comparing the TL of different building partitions computed using the TMM with the experimental sound insulation determined by means of laboratory measurements
Simultaneous recording of electrical and metabolic activity of cardiac cells in vitro using an organic charge modulated field effect transistor array
In vitro electrogenic cells monitoring is an important objective in several scientific and technological fields, such as electrophysiology, pharmacology and brain machine interfaces, and can represent an interesting opportunity in other translational medicine applications. One of the key aspects of cellular cultures is the complexity of their behavior, due to the different kinds of bio-related signals, both chemical and electrical, that characterize these systems. In order to fully understand and exploit this extraordinary complexity, specific devices and tools are needed. However, at the moment this important scientific field is characterized by the lack of easy-to-use, low-cost devices for the sensing of multiple cellular parameters. To the aim of providing a simple and integrated approach for the study of in vitro electrogenic cultures, we present here a new solution for the monitoring of both the electrical and the metabolic cellular activity. In particular, we show here how a particular device called Micro Organic Charge Modulated Array (MOA) can be conveniently engineered and then used to simultaneously record the complete cell activity using the same device architecture. The system has been tested using primary cardiac rat myocytes and allowed to detect the metabolic and electrical variations thar occur upon the administration of different drugs. This first example could lay the basis for the development of a new generation of multi-sensing tools that can help to efficiently probe the multifaceted in vitro environment
AVHRR Automated detection of volcanic clouds.
A new satelliteâbased technique has recently been proposed which seems suitable for an automatic detection of volcanic clouds in daytime conditions. In this paper the robustness of such a new approach, in particular in detecting early eruptive clouds, is evaluated, on several eruptive events at Mt Etna, by using five years of Advanced Very High Resolution Radiometer (AVHRR) data. The detection scheme is discussed together with its possible extension to nightâtime monitoring and the improvements expected by its application to the next generation of satellite sensors (in particular Spinning Enhanced Visible and Infrared Imager (SEVIRI)) with enhanced spectral and temporal resolution. The proposed approach seems to overcome the limitations related to other proposed methods which, in some conditions (very fresh eruptive clouds, coldâbackgrounds, etc.), give false or missed detection and will no longer be applicable to the next generation of Geostationary Operational Environmental Satellites (GOES) due to the planned reduction of their thermal infrared channels until 2010
An organic transistor-based system for reference-less electrophysiological monitoring of excitable cells
In the last four decades, substantial advances have been done in the understanding of the electrical behavior
of excitable cells. From the introduction in the early 70âs of the Ion Sensitive Field Effect Transistor (ISFET),
a lot of effort has been put in the development of more and more performing transistor-based devices to
reliably interface electrogenic cells such as, for example, cardiac myocytes and neurons. However, depending
on the type of application, the electronic devices used to this aim face several problems like the intrinsic
rigidity of the materials (associated with foreign body rejection reactions), lack of transparency and the
presence of a reference electrode. Here, an innovative system based on a novel kind of organic thin film
transistor (OTFT), called organic charge modulated FET (OCMFET), is proposed as a flexible, transparent,
reference-less transducer of the electrical activity of electrogenic cells. The exploitation of organic
electronics in interfacing the living matters will open up new perspectives in the electrophysiological field
allowing us to head toward a modern era of flexible, reference-less, and low cost probes with high-spatial and
high-temporal resolution for a new generation of in-vitro and in-vivo monitoring platforms
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