Effect of tomato variety, cultivation, climate and processing on Sola l 4, an allergen from Solanum lycopersicum

Tomatoes (Solanum lycopersicum) are one of the most consumed vegetables worldwide. However, tomato allergies in patients suffering from birch pollen allergy occur frequently. Due to highly similar protein structures of the tomato allergen Sola l 4 and the major birch pollen allergen Bet v 1, patients cross-react with allergenic proteins from tomato as well as other fruits or vegetables. The aim of this study was to quantify Sola l 4 in various tomatoes differing in color, size and shape for identification of varieties with a reduced allergen level. Therefore, an indirect competitive ELISA using a specific polyclonal Sola l 4 antibody was developed. In addition, two varieties, both cultivated either conventionally or organically and furthermore dried with different methods, were analyzed to investigate the influence of the cultivation method and processing techniques on Sola l 4 level. Within 23 varieties, Sola l 4 content varied significantly between 0.24 and 1.71 μg Sola l 4/g FW. The tomato cultivars Rugantino and Rhianna showed the significantly lowest level, whereas in cultivars Farbini and Bambello the significantly highest concentration was determined. Drying of tomatoes in the oven and by sun resulted in a significant decrease. The thermal instability was verified for the recombinant Sola l 4 emphasizing the results for the native protein in dried tomato samples. Overall, the Sola l 4 content is cultivar-dependent and no correlation between color and Sola l 4 amount was found. During the drying process of tomatoes Sola l 4 level was significantly reduced due to thermal instability. Growing conditions have a minor effect whereas seasonal effects show a more pronounced impact. These findings could extend the knowledge about the allergen level of different tomato varieties and may help to improve food safety to potentially increase the life quality of patients suffering from birch pollen allergy

Influence of the Experimental Setup on the Damping Properties of SLM Lattice Structures

Background: Metal lattice structures obtained through Selective Laser Melting may increase the strength-to-weight ratio of advanced 3D printed parts, as well as their damping properties. Recent experimental results showed that AlSi10Mg and AISI 316L lattices are characterized by higher Rayleigh damping coefficients with respect to the fully dense material. However, some unclear or contradictory results were found, depending on the experimental setup adopted for modal analysis. Objective: In this work the influence of the experimental setup when performing modal analysis on different SLM AISI 316L lattice structures was deeply investigated. The study provides a critical comparison of various experimental modal analysis approaches, allowing to evaluate the influence of external damping sources and material internal damping phenomena. Methods: The dynamic behaviour of SLM AISI 316L specimens incorporating lattice structures was estimated by means of pulse testing and sinusoidal excitation through an electromagnetic shaker. The validity of the viscous damping model was assessed by means of sinusoidal excitation with different levels of vibration velocity. Moreover, the influence of experimental setup on modal analysis results was critically evaluated, by considering different actuators, contact and non-contact sensors and boundary/clamping conditions. Results: The classical viscous damping model describes with good approximation the damping properties of SLM lattice structures. When exciting single specimens in free-free conditions, those embedding lattice structure and unmelted metal powder filler were characterized by superior internal damping properties with respect to the specimens incorporating the lattice structure without any filler, which was however more effective than the full density equivalent material. Most of the other experimental setups introduced additional external damping sources, that could alter this important outcome. Conclusions: SLM lattice structures embedded into 3D printed components provide superior damping properties against mechanical and acoustic vibrations and the metal powder filler does significantly enhance such damping capacity. A correct estimation of material internal damping was achieved by applying non-contact sensors and free-free boundary conditions, whereas other experimental setups were partly inadequate

Passive chatter suppression of thin-walled parts by means of high-damping lattice structures obtained from selective laser melting

Chatter vibrations arising during machining operations are detrimental for cutting process performance, since they may cause poor surface quality of the machined part and severe damages to machine tool elements. Passive approaches for chatter suppression are based on the integration of special mechanical components with high-damping properties within the machining system. They represent a good solution to this problem thanks to their intrinsic simplicity. Recently, the application of metallic lattice structures inside 3D printed parts obtained from the Selective Laser Melting technology have proven superior damping properties with respect to the same full density material. Here, this idea is further explored by considering the novel configuration where the unmelted powder grains are retained inside the lattice structure by an external shell, acting as a multiplicity of microscopic mechanical dampers. This concept is applied for passive chatter suppression of thin-walled parts that are of particular relevance for industry. Preliminary experimental investigation was first carried out on simple beam-like specimens, and then on thin-walled benchmarks that were identified through modal analysis and tested under real cutting conditions. The main conclusion is that the novel proposed configuration (lattice plus unmelted powder) has higher damping properties with respect to the full density and lattice alternatives. Accordingly, it may be successfully applied for passive chatter suppression in real machining operations

Smartphone use and addiction during the coronavirus disease 2019 (COVID-19) pandemic: cohort study on 184 Italian children and adolescents

Background: The lives of many children and adolescents are today increasingly influenced by new technological devices, including smartphones. The coronavirus disease 2019 (COVID-19) pandemic occurred in a time of outstanding scientific progress and global digitalization. Young people had relevant adverse psychological and behavioral effects due to the COVID-19 pandemic, mainly related to infection control measures, which led them to spend more time at home and with major use of technological tools. The goal this study proposes is to evaluate health and social outcomes of smartphone overuse among Italian children and adolescents during the COVID-19 pandemic, analyzing patterns and aims of utilization, as well as the eventual presence and degree of addiction. Methods: This study was based on a self-report and anonymous questionnaire, which was administered to 184 Italian school-age (6–18 years) children and adolescents during the second wave of the COVID-19 pandemic. The test was electronically (email, whatsapp) explained and sent by pediatricians either directly to older children (middle and high school), or indirectly, through the help of teachers, to younger ones (primary school). All participants spontaneously and voluntarily joined the present study. The survey was made by 4 sections, and designed to know and outline modalities (frequency, patterns and aims) of smartphone use, adverse outcomes, and related parental behaviors, also in order to reveal the eventual occurrence and degree of addiction. The same information, related to the pre-epidemic period, was also investigated and analyzed. Results: The data obtained revealed a significantly greater adhesion to the questionnaire by females, likely reflecting higher attention and interest than boys to initiatives relating to health education. Our study showed more frequent smartphone use among Italian children and adolescents during the COVID-19 pandemic, compared to the pre-epidemic period. This may be related to the social distancing measures adopted during the months under investigation. The present survey also outlined the changing patterns and aims in the use of smartphones among young people, which allowed to limit some effects of the crisis. Indeed, they were used for human connection, learning and entertainment, providing psychological and social support. Finally, it was observed a significant increase of overuse and addiction. This led to many clinical (sleep, ocular and musculoskeletal disorders), psychological (distraction, mood modification, loss of interest) and social (superficial approach to learning, isolation) unfavorable outcomes. Conclusions: Pediatricians and health care professionals should be aware of the potential risks related to inappropriate use of smartphones. They should monitor, in cooperation with parents, possible associated adverse effects, in order to early recognize signs and symptoms suggestive, or at high risk, for addiction. They must carry out, as well, the necessary interventions to prevent and/or lower the detrimental impact of smartphone overuse on children and adolescents’ health, oriented to sustain adequate physical and psychological development as well as social relationships

Cooking influence on physico-chemical fruit characteristics of eggplant (Solanum melongena L.)

Physico-chemical traits of three eggplant genotypes ("Tunisina", "Buia" and "L 305") were evaluated before and after two cooking treatments (grilling and boiling). Different genotypes revealed different changes after cooking, with "Tunisina" showing a better retention of phytochemicals with respect to other two genotypes. The main physical phenomena were water loss during grilling, and dry matter loss after boiling. Chlorogenic acid, the main phenolic in eggplant, resulted higher in grilled samples, while delphinidin glycosides resulted more retained in boiled samples. Glycoalkaloids, thiols and biogenic amines were generally stable, while 5-hydroxy-methyl-furfural was found only in grilled samples. Interestingly, Folin-Ciocalteu index and free radical scavenging capacity, measured with three different assays, were generally increased after cooking, with a greater formation of antioxidant substances in grilled samples. NMR relaxation experiments clarified the hypothesis about the changes of eggplant compounds in terms of decomposition of larger molecules and production of small ones after cooking

Le conoscenze in Física all'inizio dei corsi universitari in Italia

The article reports the results of an investigation on Italian university students concerning physics knowledge related to common sense schemes at the beginning of the university courses. The results of the diagnosis were communicated both to the students and to the teachers of the courses. The communication enabled the teachers, in the didactical practice, to pinpoint and discuss with the students the discrepancies between the scientific newtonian scheme and common sense scheme. A posttest, given at the end of the course, gives the indication that this practice is effective in inducing a change in the students ideas, notwithstanding the fact that no complete understanding of the scientific viewpoint is teached by the majority of students