Au@MNPs-based electrochemical immunosensor for vitamin D3 serum samples analysis

We report a new sensitive label-free electrochemical immunosensor to detect Vitamin D3 (25-OHD3) in untreated serum samples. To this aim, a graphite screen printed electrode (SPE) was modified using cysteamine (CYM) functionalized core-shell magnetic nanoparticles (Au@MNPs) then, the 25-OHD3 antibody (AbD) was immobilized via glutaraldehyde crosslinking. The several steps involved in the immunosensor development and 25-OHD3 analysis were monitored by using differential pulse voltammetry (DPV). The developed immunosensor showed a LOD of 2.4 ng mL−1 and a linear range between 7.4 and 70 ng mL−1. The effectiveness of the immunosensor in human serum analysis was assessed by comparing the results obtained with the chemiluminescence-immunoassay (CLIA) reference method. The high sensitivity and excellent agreement with the reference method suggest its potential use as a POCT to monitor hypovitaminosis 25-OHD levels

Speckle patterns for DIC in challenging scenarios: rapid application and impact endurance

Digital image correlation (DIC) is a widely used technique in experimental mechanics for full field measurement of displacements and strains. The subset matching based DIC requires surfaces containing a random pattern. Even though there are several techniques to create random speckle patterns, their applicability is still limited. For instance, traditional methods such as airbrush painting are not suitable in the following challenging scenarios: (i) when time available to produce the speckle pattern is limited and (ii) when dynamic loading conditions trigger peeling of the pattern. The development and application of some novel techniques to address these situations is presented in this paper. The developed techniques make use of commercially available materials such as temporary tattoo paper, adhesives and stamp kits. The presented techniques are shown to be quick, repeatable, consistent and stable even under impact loads and large deformations. Additionally, they offer the possibility to optimise and customise the speckle pattern. The speckling techniques presented in the paper are also versatile and can be quickly applied in a variety of materials

Metopic synostosis

Premature closure of the metopic suture results in a growth restriction of the frontal bones, which leads to a skull malformation known as trigonocephaly. Over the course of recent decades, its incidence has been rising, currently making it the second most common type of craniosynostosis. Treatment consists of a cranioplasty, usually preformed before the age of 1 year. Metopic synostosis is linked with an increased level of neurodevelopmental delays. Theories on the etiology of these delays range from a reduced volume of the anterior cranial fossa to intrinsic malformations of the brain. This paper aims to provide an overview of this entity by giving an update on the epidemiology, etiology, evolution of treatment, follow-up, and neurodevelopment of metopic synostosis

Structural damage analysis on a typical aeronautical structure using piezoelectric devices19th AIAA Applied Aerodynamics Conference

The present work relates to the assessment and testing of an experimental based technique devoted to the structural incipient damage detection and location. The technique bases its fundamentals on experimental FRF's comparison and manipulation so to extract a damage index (DI) value as correlated as possible with the real modification of the structure. In this work an application of such a procedure on a typical aeronautical structure has been investigated. A cross talking configuration with separate locations for actuators and sensors for the FRF's acquisition has been chosen and piezoceramic patches has been selected as both devices. To verify the sensibility of the technique to reveal and locate a typical shear clip damage, a set of rivets have been successively cut in the area surrounding the frame shear clip. The analysis of the data showed a good sensibility of the system to identify the presence of a damage with maximum values of the DI in the sensor closest to the damage location and with a absolute value of the index growing up with damage extension