In dialogo con Vico

Traducción del italiano por María José Rebollo Espinosa.El texto constituye el extracto de una “entrevista a Vico”, aún inédita, imaginaria pero rigurosamente basada en textos viquianos, a la que solamente se le han añadido las necesarias modernizaciones lingüísticas.This text is an extract of an “interview with Vico”, still unpublished, imaginary but rigorously based on Vichian texts, to which only the necessary linguistic modernizations have been added.Il presente testo è l’estratto di un “colloquio con Vico”, tuttavia inedito, immaginario ma rigorosamente basato su testi viquiani, a cui sono state aggiunte solo alcune necessarie modernizzazioni linguistiche

RASEM Squared: Assisting Students in their Transition to the STEM Workforce

RASEM Squared works to increase the number of people with disabilities pursuing careers in science, technology, engineering, and mathematics (STEM) fields. To accomplish this goal, it provides funding directly to students to support their college education and to educators who accommodate students with disabilities in their STEM curricula. This paper describes several projects that illustrate RASEM Squared’s activities, and identifies six major issues that have arisen in its work. These issues involve student self-disclosure, transition from supports under the Individuals with Disabilities Education Act (IDEA) to those under the American with Disabilities Act (ADA), training of special education and science education teachers, use of assistive technology (AT) devices, compatibility of software and hardware, and links between services

Controlled Drug Delivery for Cancer Treatment Using Electrospun Structure

Le cancer étant l’une des premières causes de décès dans les pays développés, les chercheurs doivent continuer à mettre au point de nouvelles stratégies eÿcaces pour traiter les patients. De nombreux traitements couramment utilisés agissent souvent sur des processus cellulaires de base, entraînant des e˙ets secondaires et nuisant à la qualité de vie du patient. En outre, ces médicaments ont souvent des fenêtres thérapeutiques très étroites et, en raison de leur mode d’administration, leur concentration initiale dépassera le seuil de toxicité. Les stratégies récemment développées pour répondre à ces problèmes sont la combinaison d’une administration contrôlée et ciblée des médicaments, visant un traitement localisé avec un dosage plus faible libéré sur une plus longue période. D’autre part, l’électrofilage et l’électronébulisation sont des méthodes qui suscitent un intérêt croissant pour la fabrication de composés pharmaceutiques. Ces techniques partagent une configuration simple qui permet une grande polyvalence, permettant même l’électrofilage de plusieurs solutions à la fois, en électrofilage coaxial. Cette caractéristique permet d’obtenir des particules noyau-enveloppe en une seule étape, di˙éremment de la plupart des méthodes actuellement employées pour ce faire. Ce projet vise à utiliser la technique d’électronébulisation pour concevoir et tester un vecteur d’administration de médicaments. La littérature a été examinée afin de trouver un agent pharmaceutique présentant un profil de toxicité qui nécessiterait le plus une libération pro-gressive, in situ. En fait, le médicament choisi, doxorubicin (DOX), est connu pour aug-menter les risques de cardiomyopathies à long terme, même à très faible dose. Le délai et les conditions les plus appropriés pour l’administration ont ensuite été recherchés, afin de comprendre les exigences que le matériau de piégeage devrait avoir. Cela a abouti au choix d’un copolymère 50/50 poly(lactic-co-glycolic acid) (PLGA), qui serait capable de perdre lentement de la masse et de libérer le médicament sur une période de trois à quatre semaines. Afin de réduire les coûts et les risques, l’ibuprofène a été choisi comme médicament test lors des étapes préliminaires des travaux. L’optimisation du processus d’électronébulisation, par un mélange d’analyse de la littérature et d’essais et erreurs, a permis d’obtenir des particules de 598 ±286 nm. Malheureusement, les expériences se sont arrêtées lorsque les mesures contre le Covid-19 ont été mises en place et une fois l’accès aux laboratoires rétabli, les conditions environnementales ont changé et les paramètres optimisés n’ont pas donné les mêmes résultats. Après une phase de tests visant à rétablir les conditions idéales pour les paramètres optimisés, la production a été transférée dans une installation di˙érente, équipée d’un système capable de surmonter les problèmes. Grâce aux connaissances acquises lors de la précédente optimisation, des particules de 685,9±286 nm ont été rapidement produites, permettant au projet de passer à la phase suivante. La dégradation du polymère et l’administration du médicament ont été caractérisées par une série de tests qui ont consisté à immerger deux groupes d’échantillons de particules pendant 28 jours, un groupe dans une solution de PBS avec un pH de 7.4, l’autre dans une solution similaire avec un pH de 6.6, afin d’imiter l’environnement acide que l’on trouve dans les tissus cancéreux. Le pH des échantillons, ainsi que leur perte de poids, ont été suivis au fil des semaines, tandis que des spectres FTIR étaient acquis pour caractériser la libération du médicament et que les échantillons étaient mis de côté pour être lyophilisés et observés plus tard avec MEB. La baisse du pH a permis de confirmer la dégradation du PLGA. L’observation avec le MEB a montré que les particules avaient formé des agglomérats en PBS. En ce qui concerne l’administration du médicament, la présence d’agglomérats plus gros a certainement retardé le délai prévu. Si ces tests ont permis d’avoir une première idée du comportement des particules, plusieurs problèmes rencontrés ont mis en évidence la nécessité de les répéter afin de fournir un aperçu beaucoup plus précieux des structures produites. Enfin, les travaux présentés ici ont permis de tester la faisabilité de l’utilisation de la technique d’électro-pulvérisation coaxiale comme autre moyen de produire des particules nanométriques cœur-enveloppe. Deux questions principales ont permis de conclure que cette technique pourrait être mieux appliquée à l’échelle micrométrique. En e˙et, si les particules peuvent être obtenues à plus petite échelle, le processus d’optimisation peut être long et il peut y avoir des concessions à faire en ce qui concerne leur morphologie. En outre, le rendement a tendance à être très faible et devrait certainement être amélioré pour être compétitif dans un cadre industriel.----------ABSTRACT With cancer being one of the first causes of death in developed countries, researchers need to keep coming up with new, eÿcient strategies to treat patients. Many of the treatments commonly employed often act on basic cellular processes, causing side e˙ects and hindering the patient’s quality of life. Moreover, these drugs often have very narrow therapeutic win-dows and, due to their administration methods, their initial concentration will overshoot the toxicity threshold. The recent strategies developed to address these issues are the combina-tion of controlled and targeted drug delivery, aiming for a localized treatment with a lower dosage released over a longer time. On the other hand, the electrospinning and electrospraying are methods gaining increased interest for the fabrication of pharmaceutical compounds. These techniques share a simple set-up that allows for great versatility, even allowing for the electrospinning of multiple solution at once, in coaxial electrospinning. This feature can obtain core-shell particles in a single step, di˙erently than most methods currently employed to do so. This project set out to employ the coaxial electrospraying technique to design and test a drug delivery carrier. The literature was looked into to find a pharmaceutical agent with a toxicity profile that would most need a gradual, in situ release. In fact, the chosen drug, doxorubicin (DOX), is known to increase risks of long-term cardiomyopathies even with very low dosages. The most appropriate time frame and conditions for the delivery were then researched, to understand the requirements that the entrapping material would need have. This resulted in the choice of a 50/50 poly(lactic-co-glycolic acid) (PLGA) copolymer, which would be able to slowly lose mass and release the drug over the course of three to four weeks. To reduce costs and risks, ibuprofen was selected as a test drug during the preliminary steps of the work. The optimization of the electrospraying process, through a mix of literature review and trial and error, allowed to obtain particles of 598 ±286 nm. Unfortunately, the experiments came to a halt as measures against Covid-19 were put in place and once access to the laboratories was reestablished the environmental conditions had changed and the optimized parameters were not achieving the same results. After a phase of tests geared towards restoring the ideal conditions for the optimized parameters, the production moved to a di˙erent set-up, equipped with a system able to overcome the issues. Thanks to the knowledge acquired with the previous optimization, particles of 685.9 ±286 nm were quickly produced, allowing the project to proceed to its next phase.The degradation of the polymer and the delivery of the drug were characterized in a series of tests which involved submerging two sample groups of particles over the course of 28 days, one group in a PBS solution with a 7.4 pH, the other in a similar solution with a 6.6 pH, in order to mimic the acidic environment found in cancer tissues. The pH of the samples, as well as their weight loss was monitored through the weeks, while FTIR spectra were being taken to characterize the drug release and samples were put aside to be freeze dried and later observed with SEM. The pH decrease was able to confirm the degradation of PLGA. The SEM observation showed that the particles had formed agglomerates in PBS. For what concerns the drug delivery, the presence of bigger clusters has certainly delayed the expected time frame. While these tests allowed for an initial outlook over the particles’ behaviour, several issues encountered highlighted the need to repeat them in order to provide a much more valuable insight regarding the structures produced. Finally, the work here presented was able to test the feasibility of employing the coaxial electrospraying technique as an alternative way to produce nanometric core-shell particles. Two main issues brought to the conclusion that this technique might be better applied to the micrometric scale. In fact, while particles can be obtained in the smaller scale, the optimization process can be lengthy and there might be concessions to be made for what concerns their morphology. Moreover, the yield tends to be very poor and would need to be certainly improved to be competitive in an industrial setting

Exposure and susceptibility of inactive and abandoned tailings to flash floods in Chile

The 2020 Global Industry Standard on Tailings Management exemplifies the move to reduce risks posed by tailings worldwide. However, inadequate attention focuses on various non-active tailings, which may ultimately become the responsibility of national or state regulators. This challenge is particularly evident in Chile, which hosts 467 inactive and 173 abandoned tailings according to Chile’s National Geology and Mining Service (SERNAGEOMIN). The two drivers of tailings failures globally are heavy precipitation and seismic activity. In Chile, from 1915 to 2010, earthquakes accounted for about 80 per cent of recorded major tailings failures, with heavy rainfall mainly responsible for the remainder. Since 2015, however, there have been several extreme rainfall and associated flash flood events in northern Chile that have mobilized tailings. Events in 2015 and 2017 have been analyzed remotely to understand the mechanisms and magnitudes of tailings erosion and mobilization. The 24–26 March 2015 intense rainfall event most affected the Salado river basin and led to significant modification of the tailings beach at Chañaral in the Atacama Region. At least several 100 000 m3 of tailings were scoured from the beach and transported into coastal water. Another inundation event on 11–13 May 2017 caused erosion, undercutting and partial collapse of several inactive and abandoned tailings deposits along the Marquesa river channel, which is a tributary of the Elqui river in the Coquimbo Region. The total volume of missing tailings is of the order of 100 000 m3 . These volumes are of magnitudes equivalent to those reported for some of the most significant tailings failures in Chile and highlight the urgency to systematically assess the exposure of Chile’s tailings to floods, particularly in the context of changing climate and weather patterns

Lab-Scale Zero Exchange Shrimp Aquaculture

ME450 Capstone Design and Manufacturing Experience: Winter 2008Shrimp aquaculture is a global market that tends to negatively impact the environment due to excess nitrogen rich waste. The School of Natural Resources in coordination with the Department of Environmental Engineering at the University of Michigan are in need of over ten separate closed loop zero-exchange shrimp aquaculture systems to research survival and growth potential for dense shrimp populations. The focus is on biofilters, feed, and various environmental conditions. At the completion of the project there should be two customizable experimental lab setups prepared for the University of Michigan researchers to effectively conduct experiments.Prof. Jim Diana and Prof. Lutgarde Raskinhttp://deepblue.lib.umich.edu/bitstream/2027.42/58676/1/me450w08project25_report.pd

Acute Embolic Occlusion of the Left Common Iliac Artery Treated With Intra-Arterial Thrombolysis and Percutaneous Thrombectomy

Acute embolic occlusion of the common iliac artery is a rare medical emergency that is not only limb-threatening, but also potentially life-threatening. Several treatment options exist for acute limb ischemia, although no treatment is clearly best. We report a case of acute embolic occlusion of the left common iliac artery in a patient with atrial fibrillation who was treated successfully using mechanical thrombectomy following intra-arterial thrombolysis

Epithelialization of hydrogels achieved by amine functionalization and co-culture with stromal cells

The aim of this study was to develop a hydrogel which would be suitable for corneal cell re-epithelialization when used as a corneal implant. To achieve this, a series of hydrogels were functionalized with primary amines by post-polymerization reactions between amine compounds and glycidyl ether groups attached to the hydrogels. We report a strong correlation between the structure of the amine and the viability of stromal cells and epithelial cells cultured on these hydrogels. Subsequent co-culture of epithelial and stromal cells on the amine modified hydrogels allowed successful expansion of epithelial cells on surfaces functionalized with alkyl α–ω diamines with carbon chain lengths of between 3 and 6. Analysis of variance showed that corneal epithelial cells had a strong preference for surfaces functionalized by the reaction of excess 1,3 diaminopropane with units of glycidyl methacrylate compared to the reaction products of other amines (ammonia; 1,2-diaminoethane; 1,4-diaminobutane or 1,6-diaminohexane). We suggest this approach of amine functionalization combined with stromal/epithelial co-culture offers a promising new approach to achieving a secure corneal epithelium. Keywords: Epithelial cell