1,296 research outputs found
Supramolecular aggregates containing lipophilic Gd(III) complexes as contrast agents in MRI
Magnetic resonance imaging (MRI) contrast agents based on paramagnetic gadolinium complexes
are widely used in biomedical research and diagnosis. Their application is intended to improve efficacy
of MRI providing physiological information along with the impressive anatomical detail already
obtained by images without contrast. The classical gadolinium complexes currently used for MRI contrast
enhancement are all lowmolecularweightcompounds that rapidly equilibrate between the intra and
extravascular spaces after intravenous administration. In order to obtain gadolinium-based agents with
different pharmacokinetic properties, supramolecular aggregates such as micelles and liposomes have
been recently proposed. Micelles and liposomes, obtained by the aggregation of lipophilic gadolinium
complexes are here described, with the aim to correlate their structural and relaxometric properties.We
report on the state of the art in the development of supramolecular aggregates obtained by self-assembly
of lipophilic gadolinium complexes and aggregates in which lipophilic gadolinium complexes are assembled
with surfactants. Moreover aggregates derivatized with bioactive molecules, such as peptides and
antibodies, acting as target selective MRI contrast agents are described
End-of-Life Impact on the Cradle-to-Grave LCA of Light-Duty Commercial Vehicles in Europe
A cradle-to-grave life cycle assessment focused on end-of-life (EoL) was conducted in this study for three configurations of a light-duty commercial vehicle (LDCV): diesel, compressed natural gas (CNG), and battery electric vehicle (BEV). The aim is to investigate the impact of recycling under two EoL scenarios with different allocation methods. The first is based on the traditional avoided burden method, while the second is based on the circular footprint formula (CFF) developed by the European Commission. For each configuration, a detailed multilevel waste management scheme was developed in compliance with the 2000/53/CE directive and ISO22628 standard. The results showed that the global warming potential (GWP) impact under the CFF method is significantly greater when compared to the avoided burden method because of the A-parameter, which allocates the burdens and benefits between the two connected product systems. Furthermore, in all configurations and scenarios, the benefits due to the avoided production of virgin materials compensate for the recycling burdens within GWP impact. The main drivers of GWP reduction are steel recycling for all of the considered LDCVs, platinum, palladium, and rhodium recycling for the diesel and CNG configurations, and Li-ion battery recycling for the BEV configuration. Finally, the EoL stage significantly reduces the environmental impact of those categories other than GWP
Influence of Mother Tongue on Dynamic Handwriting Features in Primary School
Handwriting is an essential fine motor skill in school-aged children and plays a crucial role for educational development and autonomy of everyday life. To analyze hand-writing movement an objective quantitative kinematic analysis can be performed by using digital tablets. Through this tech-nology it was possible to identify a lot of parameters useful to characterize the handwriting process.
In order to study the influence of mother tongue on the dy-namic of handwriting in primary school, we examined the writing response of 42 non-native speakers and compared their characteristics with those of 131 Italian mother tongue chil-dren. All children undertook one repetitive sequence of le and an Italian sentence written in two different ways: as accurately as and as fast as possible.
The results showed that the differences between native and non-native speakers were not significant in the repetitive se-quence while a clear influence of mother tongue was present only in the third grade for the sentence tasks
Return to school in the COVID-19 era: considerations for temperature measurement
COVID-19 pandemics required a reorganisation of social spaces to prevent the spread of the virus. Due to the common presence of fever in the symptomatic patients, temperature measurement is one of the most common screening protocols. Indeed, regulations in many countries require temperature measurements before entering shops, workplaces, and public buildings. Due to the necessity of providing rapid non-contact and non-invasive protocols to measure body temperature, infra-red thermometry is mostly used. Many countries are now facing the need to organise the return to school and universities in the COVID-19 era, which require solutions to prevent the risk of contagion between students and/or teachers and technical/administrative staff. This paper highlights and discusses some of the strengths and limitations of infra-red cameras, including the site of measurements and the influence of the environment, and recommends to be careful to consider such measurements as a single \u201csafety rule\u201d for a good return to normality
Naposomes: a new class of peptide-derivatized, target-selectivemultimodal nanoparticles for imaging and therapeutic applications
Modified supramolecular aggregates for selective delivery of contrast agents and/or drugs are examined with a focus on a new class of peptide-derivatized nanoparticles: naposomes. These nanoparticles are based on the co‑aggregation of two different amphiphilic monomers that give aggregates of different shapes and sizes (micelles, vesicles and liposomes) with diameters ranging between 10 and 300 nm. Structural properties and in vitro and in vivo behaviors are discussed. For the high relaxitivity values (12–19 mM-1s-1) and to detect for the presence of a surface exposed peptide, the new peptide-derived supramolecular aggregates are very promising candidates as targetselective MRI contrast agents. The efficiency of surface-exposed peptides in homing these nanovectors to a specific target introduces promising new opportunities for the development of diagnostic and therapeutic agents with high specificity toward the biological target and reduced toxic side effects on nontarget organs
A Deep Learning Method for Automatic Identification of Drusen and Macular Hole from Optical Coherence Tomography
Deep Learning methods have become dominant in various fields of medical imaging, including ophthalmology. In this preliminary study, we investigated a method based on Convolutional Neural Network for the identification of drusen and macular hole from Optical Coherence Tomography scans with the aim to assist ophthalmologists in diagnosing and assessing retinal diseases
Development of a Male Turbo-Prop Unmanned Aerial Vehiche for Civil Application
Unmanned Aerial Vehicles (UAV) increasingly are seen as the next step in aircraft evolution with the potential to replace manned aircraft over a broad range of civilian roles. Industry, who recognise the cost effectiveness of UAV, is keen to grasp this potential and the technology is rapidly developing with numerous projects currently in operation of development throughout Europe and worldwide. In response to this needs University of Naples has developed a MALE configuration TurboProp engined using innovative structural and aerodynamic solutions. Regarding the structural aspect the extensive use of composite materials led to the definition of a weight efficient vehicle capable to carry on up to 500 kg of payloads covering a wide range of medium altitude missions. With reference to aerodynamic solution, an Eppler modified profile, numerically optimized, has been adopted for its efficiency that has granted long endurance and, coupled with the power provided by the chosen engine (PT6A – 67 B), high performance. The aeroelastic assessment has revealed that no critical phenomena occur in the flight envelope. Once defined the aerodynamic and structural aspects, an analysis of reliability and safety has been performed aimed to evaluate MTBL (Mean Time Between Loss) and MTBCF (Mean Time Between Critical Failure) features
Amphiphilic CCK peptides assembled in supramolecular aggregates: structural investigations and in vitro studies
Supramolecular aggregates obtained by self-aggregation of five new cationic amphiphilic CCK8 peptides have been obtained in water solution and characterized for: (i) aggregate structure and
stability; (ii) CCK8 peptide conformation and bioavailability on the external aggregate surface; and (iii) for their cell binding properties. The cationic amphiphilic CCK8 peptides self-aggregate giving a combination of liposomal and micelle structures, with radii ranging between B60 nm and B90 nm, and between B5 and B10 nm, respectively. The presence of CCK8 peptide well-exposed on the aggregate surface is demonstrated by fluorescence measurements. Peptide conformation changes in
the five supramolecular aggregates: the CCK8 conformational behaviour is probably induced by the presence of three charged lysine residues close to the bioactive peptide sequence. Only aggregates in which the CCK8 peptide presents a structural arrangement similar to that found for the same peptide in DPC micelles give promising binding properties to CCK2-R receptors overexpressed by transfected A431 cells. Chemical modifications on the CCK8 N-terminus seem to play an important role in stabilizing the peptide active conformation, either when the peptide derivative is in monomeric or in aggregate form. For their easy preparation procedures and their binding properties, supramolecular aggregates based on cationic peptide amphiphiles can be considered as promising candidates for target selective drug carriers on cancer cells
Navigation Facility for High Accuracy Offline Trajectory and Attitude Estimation in Airborne Applications
The paper focuses on a navigation facility, relying on commercial-off-the-shelf (COTS) technology, developed to generate high-accuracy attitude and trajectory measurements in postprocessing. Target performance is cm-level positioning with tenth of degree attitude accuracy. The facility is based on the concept of GPS-aided inertial navigation but comprises carrier-phase differential GPS (CDGPS) processing and attitude estimation based on multiantenna GPS configurations. Expected applications of the system include: (a) performance assessment of integrated navigation systems, developed for general aviation aircraft and medium size unmanned aircraft systems (UAS); (b) generation of reference measurements to evaluate the flight performance of airborne sensors (e.g., radar or laser); and (c) generation of reference trajectory and attitude for improving imaging quality of airborne remote sensing data. The paper describes system architecture, selected algorithms for data processing and integration, and theoretical performance evaluation. Experimental results are also presented confirming the effectiveness of the implemented approach
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