Selective Laser Treatment on Cold-Sprayed Titanium Coatings: Numerical Modeling and Experimental Analysis

In this paper, a selective laser post-deposition on pure grade II titanium coatings, cold-sprayed on AA2024-T3 sheets, was experimentally and numerically investigated. Morphological features, microstructure, and chemical composition of the treated zone were assessed by means of optical microscopy, scanning electron microscopy, and energy dispersive X-ray spectrometry. Microhardness measurements were also carried out to evaluate the mechanical properties of the coating. A numerical model of the laser treatment was implemented and solved to simulate the process and discuss the experimental outcomes. Obtained results highlighted the key role played by heat input and dimensional features on the effectiveness of the treatment.     

Selective Laser Post-Treatment on Titanium Cold Spray Coatings

The aim of the present work is to investigate the feasibility and effects of a selective postdeposition laser treatment on titanium coatings. Commercially pure titanium grade 2 powders were deposited by means of a cold spray process on aluminum alloy AA2024-T3 sheets. The surface treatment of the coating was realized using a 220 W diode laser. The influence of heat input and dimensional features of coating layer and substrate was assessed by an experimental campaign conducted following a design of experiments approach. Optical and scanning electron microscopy analysis of the microstructure of the deposited and treated material as well as microhardness measurements showed the formation of a compact layer of titanium oxide on the coating surface and the preservation of the temper state of the aluminum substrate.     

Use of Staphylococcus xylosus as a starter culture in dried sausages: effect on the biogenic amine content

The main objective of this work was to investigate if the use of Staphylococcus xylosus S81 as a starter culture in sausage production can influence the amount of histamine during ripening, and the concentration of the other most important biogenic amines, by influencing the activity of the microbial amino oxidases as well as the aminoacid decarboxylases. The results confirm that the biogenic amines presence in foods is the consequence of a complex equilibrium between the composition of the medium and the enzymatic activities of the microbial population. In addition, the results suggest that the presence and relative activity of amino oxidases should be considered as an important characteristic in the selection of starter cultures used in the production of fermented foods.     

Turner Syndrome Mosaicism 45,X/46,XY with Genital Ambiguity and Duchenne Muscular Dystrophy: Translational Approach of a Rare Italian Case

Turner syndrome (gonadal dysgenesis with short stature and sterility) is characterized by chromosomal karyotype 45,X in 50% of cases or by mosaicism (45,X/46,XX and 45,X/46,XY) in 30–40% or X structural defects (deletions, long arm isochromosome, ring chromosome). When mosaic Turner syndrome (TS) occurs with a Y chromosome, there may be ambiguous genitalia. Duchenne muscular dystrophy (DMD) is an inherited neuromuscular disease with an X-Linked recessive pattern of inheritance that predominantly affects males, while females are usually asymptomatic. DMD has also been observed in groups of females affected by TS, not homozygous for the mutation. Here, we report a case of an Indian neonate born with ambiguous genitalia diagnosed prenatally by ultrasound who had a karyotype of 45,X/46,XY and who also had Duchenne muscular dystrophy caused by a de novo mutation in the DMD gene. Physical examination was normal without the typical dysmorphic features of TS with the exception of the genitourinary system showing ambiguous genitalia. Gender was assigned as female. At the age of three years, she had increasing difficulty walking, running, jumping and climbing stairs, proximal upper and lower extremity muscle weakness and a positive Gowers’ sign. In addition, the serum creatine kinase (CK) value was over 30X the upper limit of normal. This study shows that DMD can occur in females with TS having 45,X/46,XY mosaicism and that this coexistence should be considered in women affected by TS who start to develop potential typical symptoms such as motor or developmental delay.     

Reactions with Proteins of Three Novel Anticancer Platinum(II) Complexes Bearing N-Heterocyclic Ligands

Three novel platinum(II) complexes bearing N-heterocyclic ligands, i.e., Pt2c, Pt-IV and Pt-VIII, were previously prepared and characterized. They manifested promising in vitro anticancer properties associated with non-conventional modes of action. To gain further mechanistic insight, we have explored here the reactions of these Pt compounds with a few model proteins, i.e., hen egg white lysozyme (HEWL), bovine pancreatic ribonuclease (RNase A), horse heart cytochrome c (Cyt-c) and human serum albumin (HSA), primarily through ESI MS analysis. Characteristic and variegate patterns of reactivity were highlighted in the various cases that appear to depend both on the nature of the Pt complex and of the interacting protein. The protein-bound Pt fragments were identified. In the case of the complex Pt2c, the adducts formed upon reaction with HEWL and RNase A were further characterized by solving the respective crystal structures: this allowed us to determine the exact location of the various Pt binding sites. The implications of the obtained results are discussed in relation to the possible mechanisms of action of these innovative anticancer Pt complexes.     

REACTION MECHANISMS OF ETHANOL DEEP OXIDATION OVER PLATINUM CATALYST

Considerable amounts of ethanal may form in ethanol deep oxidation over platinum. The selectivity toward CO₂ increases at higher temperatures and at very low concentrations. An inhibiting effect of primarily formed aldehyde on ethanol conversion rate was observed; a power-law type equation rate is not applicable to describe the kinetics. The dependence of the selectivity on the contact time indicates that the gas-phase aldehyde may adsorb on the catalyst and further react to CO₂. At lower temperature direct complete oxidation to CO₂ and partial oxidation occur as parallel competitive reactions; at higher temperature a series-parallel mechanism takes place     

Profile of enzyme in drupe of oueslati's cv. olives during ripening phases: A support method implementation in the production of extra virgin olive oil

Quality of virgin olive oil (VOO) depends on phenolic molecules content, which depends on the biochemical characteristics of olive fruits, namely endogenous enzymes. In order to ascertain the influence of olive fruit ripening degree on the phenol content, enzyme activities in olive fruits, and the quality of the corresponding oils were studied during Oueslati olive ripening. In fact, three enzymes were studied: peroxidase (POX) in olive seeds, polyphenoloxidase (PPO), and β-glucosidase (β-GL) in olive fruits mesocarp. Each enzyme showed specific trend: POX activity increased gradually until reaching a maximum (17.061 ± 0.101 U g⁻¹ FW) at ripening index (RI) 3.6 and then decreased slowly at advanced ripening stage. However, the maximum of PPO activity (240.421 ± 0.949 U g⁻¹ FW) was observed earlier at RI of 0.7. Concerning β-glucosidase activity, its maximal was 60.857 ± 1.105 U g⁻¹ FW at RI 2.8, then, it decreased sharply to reach 17.096 ± 0.865 U g⁻¹ FW at RI 3.9. A significant increase of total phenol content as well as the antioxidant activity were observed during Oueslati olive ripening. Moreover, phenolic profile indicated that appropriate harvesting date of Oueslati olives coincided with RI 3.9 given that highest content of most important individuals phenolic compounds responsible for the main VOO biological properties achieved on this date. Furthermore, phenols amount of Oueslati VOO was principally due to PPO enzyme activity as the increase in total phenols coincides with the decrease in PPO activity.     

In-Line and Off-Line Optimization of Freeze-Drying Cycles for Pharmaceutical Products

The problem of process design for the freeze-drying of pharmaceutical products is here addressed. A comparative analysis between the various optimization tools so far proposed is given. The above analysis aims to give some guidelines to lyophilization professionals in the choice of the best design strategy compatible with their objectives and the technology available. In particular, this study examines the strengths and weaknesses of design space and of the different model-based control techniques so far proposed with a view to a better understanding of factors that still limit the use of these techniques at the manufacturing scale. With this regard, the above methods are compared in terms of robustness and scalability of the cycle, number and type of input parameters, management of product and equipment constraints, as well as batch unevenness. The first part of the study is carried out by means of mathematical simulations, as this approach makes it possible to better investigate the controller performance eliminating the uncertainty due to the experiment reproducibility. This study shows that although design space can provide a detailed view of the impact of processing conditions on product quality, its use for the cycle development can hardly lead to a real process optimization. By contrast, this objective can be achieved if model-based control is used. Experiments obtained for mannitol and sucrose-based formulations confirmed this result.