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Nowadays, problems in healthcare sector seem to be more crucial than ever. Among these, cardiovascular diseases (CVDs) play an important role, being for years a major threat to human health. In a bid to reduce the number of deaths due to heart diseases by taking precautions, science has turned to the development of devices able to offer early diagnosis of a heart failure. Recently, many biosensors have been developed based on cardiac biomarkers that can be detected in blood and predict the risk of heart failure. Of these, cardiac troponin is the best known, while C-reactive protein and myoglobin have also been used. Troponin is a complex of proteins found in the thin filaments of striated muscles and consists of three protein subunits, I, C and T. In case of myocardial malfunction, troponin is released into the blood. Consequently, the detection of elevated troponin levels at an early stage in human serum, is an indication of high risk of cardiovascular event enabling early medical intervention and treatment. In the present work, after the analysis of heart diseases, medical tests, troponin and its role in controlling myocardial health, there is an overview of the available biosensor platforms for cardiac biomarkers detection.

Mapping microstructural to macroscopic magnetic properties is challenging yet necessary for the development of novel non-destructive testing techniques based on magnetic measurements. The macroscopic properties of a material reflect the underlying magnetization processes and the microstructural configuration as a result of the history of the material. Magnetic nondestructive evaluation techniques are needed for the health monitoring in critical structures and the quality monitoring of materials used in components, such as transformers and motors. In this work, we assess the usability of metrics related to AC magnetometry and magnetic Barkhausen Noise through measurements on several series of samples of various grain sizes and levels of plastic deformation. AC magnetometry is preferred to magnetic Barkhausen Noise as it provides more repeatable and reliable metrics than mBN which suffers from higher uncertainty. Also, differential permeability curves are preferred to hysteresis loops because they can be obtained directly through ac magnetometry and provide several types of information, such as the peak value, the coercivity, the overall shape, the emergence and location of multiple peaks which are related to stresses. In the case of stress-dependent magnetization processes, both differential permeability and mBN results are consistent, regardless of the way strain is applied, and corroborate results previously reported. However, permeability measurements are inconclusive on the effect of grain size on magnetization processes while the mBN voltage increases monotonically with decreasing grain size, in both types of samples. The mBN energy associated with each applied field step is proposed as a complementary measure for the assessment of the contribution of the irreversible processes in a material where the permeability measurements are inconclusive. Finally, the experimental observations have been used to set up micromagnetic calculations by modeling a plastically deformed material as a soft matrix with grains enclosed by boundaries with high transverse anisotropy which act as pinning centres and prevent further rotation of the magnetization and its alignment with the applied field thus reproducing the typical phenomenological features of plastically strained materials. © 2021 Elsevier B.V.

Different means of residual stress distribution monitoring in magnetic rods are illustrated in this paper, through measurements of permeability, magnetoelastic uniformity using two different setups, sound velocity, and eddy currents. The effectiveness of these techniques was assessed through the stress monitoring of the same magnetic rod, suffering residual stresses in two known volumes caused by controlled hammering. Furthermore, rehabilitation has been achieved by means of stress annihilation, achieved by localized induction heating. As a result, the magnetoelastic and sound velocity uniformity measurements are more appropriate for the monitoring of localized residual stresses, while eddy current measurements are useful for the monitoring of the geometrical deformation. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

Nutraceuticals have gained growing attention during the last year, becoming one of the most relevant areas of investigation. Among the existing natural sources of high value bioactive compounds, microalgae have assumed paramount importance. Indeed, they are a natural source of carotenoids, essential omega-3 fatty acids, proteins, carbohydrates, pigments, vitamins and minerals. Among these components, beta-carotene, a potent antioxidant pigment, is particularly attractive to the nutraceutical and cosmetic sector, being an ingredient in many supplements, functional, cosmetic and pharmaceutical products. Moreover, beta-carotene is one of the forms (precursor) of Vitamin A, which may be used in the manufacture of food supplements according to Directive 2002/46/EC. Even though some cyanobacteria produce beta-carotene (80% of total carotenoids) as the major components followed by zeaxanthin, the commercial biological source of betacarotene is Dunaliella salina. This microalga lives in very saline environment and has the capacity to produce beta-carotene up to 10% of the dry weight. In this work, beta-carotenewas extracted by using supercritical CO2 under optimized operational conditions, resulting in increased amount of carotenoids (from 3.46% to 18.62%), proteins (from 10.03% to 43.08%), and lipids (from 3.49% to 7.93%). Then, the investigation on the main operational parameters affecting extraction from Dunaliella salina and a cost-effectiveness evaluation of the process are presented; the results evidence as 194.3-366.6 kWh/day reflecting a cost of 26.89- 52.60euros/day are required for natural based beta-carotene recovery(59.3%) from Dunaliella salina.

Immobilization of living cells is a useful technique that allows to enhance the biotechnological properties of many organisms. Currently, cell-immobilization is obtained via carrier adsorption, self-aggregation and entrapment. We are currently investigating the possibility to immobilize microalgae cells using magnetic nanoparticles on a magnetic surface. The principle is based on the introduction, inside the cell-body of microalgae, superparamagnetic nanoparticles through electroporation. Once microalgae have absorbed enough magnetic nanoparticles they will be responding to an external magnetic field. By using a flat magnetic surface, it will be possible to trap them in a specific position by means of magnetic force. Importantly, immobilized cells will be covered with a thin layer of water and during cell division only one of the daughter cells will keep the magnetic nanoparticles since they will face permanently the magnetic surface. The first step towards this goal is the introduction of magnetic nanoparticles in the microalgae cells. This work will present preliminary results of magnetic cells preparation. Magnetic nanoparticles covered with lipid, to make them biocompatible, and electroporation method to inset nanoparticles in the cells have been used. The protocol to obtain magnetic cells and viability assay that proved the feasibility of the method will be described.

The monitoring and control of residual stresses and microstructure are of paramount importance for the steel industry. Residual stress annihilation is needed during the entire lifetime of steels. In this paper, we presented a stress monitoring and annihilation method, based on a force sensor for stress monitoring and an induction heater for localized heat treatment and corresponding stress annihilation. The heat treatment results indicated an at least 90% reduction of localized stresses, allowing for the implementation of the method in steel production and manufacturing to improve steel quality and perform faultless steel production and manufacturing. © 2020 by the authors.

In this paper, a new type of force sensor is presented, able to monitor localized residual stresses on steel surfaces. The principle of operation of the proposed sensor is based on the monitoring of the force exerted between a permanent magnet and the under-test steel which is dependent on the surface permeability of the steel providing a non-hysteretic response. The sensor’s response, calibration, and performance are described followed by a discussion concerning the applications for steel health monitoring. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

The aim of this study is to describe the synthetic procedure of superparamagnetic nanoparticles of magnetite and maghemite and to use the magnetic merit of thesenano-sized ferrite particles coated byorganic substances having good water solubility to desalinate saline water. The idea derives from the experimental results of research groups using magnetic particles covered by polymers to increase the efficiency of membranes in forward osmosis desalination plants. The magnetic particles can beseparatedfrom water by an external magnet field easily.As magnetic particles, Fe3O4 can be prepared in different sizes from nano- to microscale by the help of coprecipitation or thermal decomposition techniques. These superparamagnetic nanoparticles are wellpromising candidates for use in desalination purposes either from own or after their fabrication with polymer molecules, such as cyclodexrins, in their original form or in a modified one in order to enhance their water solubility, according to some preliminary experimental results found by our research team but not referred here. Herein, various inexpensive synthetic routes for superparamagnetic nanoparticles of magnetite(Fe3O4) and maghemite (γ -Fe2O3) are described, as well as the characterization results of the produced nanoparticles with XRD, TEM, FT-IR, RAMAN, DFT and TGA/DTG analytical techniques are also referred.