National Technological University

The building up of chitosan (CS)/gallic acid (GA) films was performed by casting method, thermally pre‐processing the reaction mixture at several temperatures and process times. This study focused on the thermal treatment impact on the antioxidant activity, mechanical deformation at break, water vapor diffusion, and surface CS film features. It is found that the thermal energy promotes the diffusion of species through CS chains as well as the GA interaction with the polysaccharide, producing films with different structural organizations. Since the crosslinking degree depends on the energy received by the system, heterogeneous materials with a low chain crosslinking and a high free GA content are generated at 40°C, while homogeneous films with covalently crosslinking are mostly generated from 50°C. The free GA availability within segregated CS film regions favors the antioxidant activity, but also the polyphenol interaction with the polysaccharide decreases the crystallinity and elastic modulus, increasing the tensile strength and elongation at break. Since a threshold of 516 kJ energy received regulates the transition from heterogeneous to homogeneous films can be thermally tuned. This discovery represents a controlling synthetic factor critical to the design of materials with unique characteristics such as those required for food packaging.

The design of non‐linear control systems remains a challenge today, therefore through this work a procedure to obtain a vertex‐reduced multi‐model representation, without loss of convexity, is proposed as a suitable solution. That is, a novel approach which considers all parameter variations around the Continuous Stirred Tank Reactor (CSTR) system operating region is developed, resulting in a unique polytopic representation. After that, based on the linear matrix inequalities approach, a control scheme is developed to compute the optimal matrix gains, while the operating, states and inputs, constraints are satisfied and the stability conditions are ensured. Finally, the realistic simulation results highlight the model representation effectiveness in capturing the CSTR dynamic behavior in the operating region, despite parameter variations, allowing the optimal control law design, overcoming the non‐linear system nature, to achieve the desired closed‐loop system performance.

The present study evaluated the potential use of methanolic extracts from two seaweeds from the Argentine Patagonian coasts, Macrocystis pyrifera and Undaria pinnatifida, as natural alternatives against Paenibacillus larvae. We carried out a detailed characterization of both seaweeds, comparing vegetative and reproductive thallus portions. We also assessed their phenolic content and antioxidant activity and evaluated the in vitro antibacterial action. Based on the minimal inhibitory concentration results, extracts from sporophyll of Undaria (US) and basal thallus portion of Macrocystis (MB) are strong inhibitors. US showed the best activity against P. larvae strain CMM(B)35 (12.2 μg/mL), and MB showed the same activity for strains CMM(B)35 and MAR1 (18.6 μg/mL). Antioxidant activity was higher in US, followed by MB, and a positive correlation was found with phenolic content. Taken together, our results indicate the role of specific chemical compounds present in algal extracts on antioxidant properties and antibacterial activity against P. larvae. We conclude that these seaweeds are promising alternatives against P. larvae.

Neurodegenerative pathologies such as age-related macular degeneration currently have no cure or effective treatment. In this type of disease, the presence of amyloid-β peptides, oxidative stress, and inflammation trigger dysregulation of retinal pigment epithelial cells and progression toward the death of these cells, resulting in a loss of vision. The production of amyloid-β peptides, oxidative stress, and inflammation can be triggered in response to viral infections. Fucoidans are sulfated polysaccharides that are present in the cell walls of brown algae. There is a large body of literature reporting a wide range of biological properties of these compounds. In this study, we investigated whether Undaria pinnatifida fucoidan extract can prevent infection with herpes simplex virus type 1 and if the extract has antioxidant activity. We also evaluated whether, under viral infection conditions, the synthesis of amyloid-β peptide and NF-κB activation could be inhibited by the extract. The results showed for the first time that this extract can prevent viral infection in retinal pigment epithelial cells and that they can prevent the formation of amyloid-β peptide and the activation of the NF-κB pathway during viral infection. We also found that Undaria pinnatifida fucoidan extract has antioxidant activity and reduces the levels of reactive oxygen species. These data suggest that Undaria pinnatifida fucoidan extract might be effective for treating diseases triggered by viral infections, such as degenerative retinal diseases.

Platinum-modified activated carbon was synthesized and studied for hydrodeoxygenation (HDO) of guaiacol. The activated carbon support was prepared using orange peel from industrial waste. Platinum was added by wetness impregnation. The activity was compared with that of platinum supported on mesoporous silica and commercial activated carbon catalysts. The catalysts prepared were characterized by different techniques: XRD and N2 adsorption isotherms to confirm the mesoporous structure, and XPS, H2-Chemisorption and Boehm titration to determine active sites and acidity. The results showed that high-surface-area active carbon support favors the formation of small platinum metallic particles, highly dispersed over the surface. The catalysts were active for guaiacol HDO performed in the laboratory at 200 °C and 12 atm of H2 in a Batch PARR reactor. Carbon was activated using phosphoric acid during the synthesis. The interaction between the peculiar acidity generated on the support by H3PO4, accompanied by the high hydrogenation capacity of the metallic platinum particles, enhanced catalytic activity, and selectivity for deoxygenated products. The most acidic-activated carbon support modified with 0.5 wt% of platinum was the most active catalyst in the HDO of guaiacol, reaching 88 mol% of guaiacol conversion and selectivity of 78% toward HDO products such as phenol, benzene and cyclohexane. The novelty of this research aims at developing an environmentally friendly catalyst to produce biomolecules of high aggregated value at mild reaction conditions reducing energy consumption. Graphical abstract

The use of video games is linked to current social changes and to inherent characteristics such as their interactive nature. They are a lens through which we can observe new dynamics and models. The video game industry is central to the entertainment and technology sector and is growing year after year in terms of audiences and profits. Recent studies from the technological, social and business sectors have attempted to analyse the effectiveness of the use of video games as tools for education, information, training, participation and interaction. A total of 286 students from two educational institutions in Argentina participated in this study, which utilized a quantitative approach with a descriptive correlational scope and a non-experimental cross-sectional design. Data collection occurred in May 2022 through non-probabilistic convenience sampling. Sociodemographic information and data on video game usage were gathered using a survey technique administered to students from both public institutions located in the Metropolitan Area of Buenos Aires. The results show that men have a greater preference for video games, confirming the relevance of such cultural products for them. There are also significant gender differences in age, hours of use, game modes, platform, and video game genre. We therefore conclude that video games are an important emerging consumer technology for different age and gender groups, and that there are gender differences and similarities in the use of video games as an entertainment activity that deserve to be explored in order to exploit the potential of these resources.

This study addresses the extension of the service life of carbon-fiber reinforced epoxies by inducing thermal healing of microcracks through the use of a vitrimer as a polymeric matrix. Our aim was to explore the feasibility of using a blend of selected carboxylic acids (citric, glutaric, and sebacic acids) and commercial monomers to design a matrix specifically developed for technological implementation in composites with the ability of intrinsic repair of microcracks under moderate (even remote) heating treatments. The selection of the formulation (the acid blend, catalysts, and monomers) was the result of an exhaustive prescreening analysis of processing requisites and final properties. The glass transition temperature of the cured vitrimer composite measured by differential scanning calorimetry (DSC) is 94 °C, a value lying in the range required for several technological applications, whereas stress relaxation to (1/e) of the initial value took ∼4.7 h at 180 °C and only 1.1 h at 200 °C. Composites containing 50 vol % of carbon fibers could be successfully prepared by compression molding. Acoustic emission tests proved the formation and partial healing of microcracks during tensile tests performed until 350 MPa. Surface scratches could also be healed by remote activation using near-infrared irradiation (NIR). These first results under nonoptimized thermal cycles are a proof of concept that microcrack and scratch healing can be produced in high glass-transition temperature epoxy-based carbon-reinforced composites.

Maps of (baseline) δ 13 C and δ 15 N values of primary producers or consumers near the base of food webs provide crucial information for interpreting patterns in the isotopic composition of consumers that occupy higher trophic levels. In marine systems, understanding how oceanographic variables influence these values enables the creation of dynamic isoscapes across time and space, providing insights into how ecosystems function. The San Jorge Gulf (SJG) in the southwest Atlantic Ocean (45 • S-47 • S) is an area of particular importance, as it is located on one of the most productive continental shelves in the world, supporting large fisheries and marine mammal and seabird populations. We reconstructed spatial variation in zooplankton δ 13 C and δ 15 N values across SJG and investigated their relationship with physical and chemical oceanographic conditions. During cruises in the austral spring of 2016 and 2017, we collected medium-sized copepods whose isotopic composition integrate short-term (days to weeks) variation in oceanographic conditions recorded by phytoplankton at the base of the food web. We also collected data on water column depth, surface and bottom temperatures, water column stability, and macronutrient (nitrate, phosphate, and silicic Biology 2024, 13, 990. https://doi.org/10.3390/biology13120990 https://www.mdpi.com/journal/biology Biology 2024, 13, 990 2 of 18 acid) concentrations. The results revealed significant variation in both δ 13 C and δ 15 N values of up to 7-8‰ over a relatively small spatial scale (200-300 km). Copepod δ 13 C values were lower at the center of the SJG, showing an inverse correlation with water column stability, surface nitrate concentration, and water column depth. δ 15 N values showed a strong and negative relationship with surface nitrate concentration and water column stability, increasing from south to north in the SJG. δ 15 N values also showed a positive relationship with surface silicic acid concentration. These spatial patterns in nutrient dynamics and copepod carbon and nitrogen isotope values are interpreted in the context of the dominant northward current and temporal development of the frontal systems in the SJG.

Los patrones sociales actuales de producción y consumo provocan una doble crisis ambiental de escasez de recursos y sobrecarga de residuos. La propuesta de una economía circular que contribuya a un medio ambiente resiliente y al bienestar humano permitirá contribuir a los Objetivos de Desarrollo Sostenible de la ONU. Las iniciativas de investigación-acción participativa pueden formar parte de esta transición, generando evidencia que valorice los residuos integrando factores ambientales, sociales y económicos. En este artículo se presenta una secuencia de experiencias de dispositivos participativos en la Comarca VIRCH-Valdés, Chubut, y los instrumentos utilizados para generar estrategias de valor agregado sobre la base de residuos industriales y urbanos, mediante el diseño de tecnologías sociales orientadas a identificar y valorar los beneficios de cambios en la demanda de servicios ecosistémicos.

Sphere formation assay is an accepted cancer stem cell (CSC) enrichment method. CSCs play a crucial role in chemoresistance and cancer recurrence. Therefore, CSC growth is studied in plates and microdevices to develop prediction chemotherapy assays in cancer. As counting spheres cultured in devices is laborious, time-consuming, and operator-dependent, a computational program called the Automatic Quantification of Spheres Algorithm (ASQA) that detects, identifies, counts, and measures spheres automatically was developed. The algorithm and manual counts were compared, and there was no statistically significant difference (p = 0.167). The performance of the AQSA is better when the input image has a uniform background, whereas, with a nonuniform background, artifacts can be interpreted as spheres according to image characteristics. The areas of spheres derived from LN229 cells and CSCs from primary cultures were measured. For images with one sphere, area measurements obtained with the AQSA and SpheroidJ were compared, and there was no statistically significant difference between them (p = 0.173). Notably, the AQSA detects more than one sphere, compared to other approaches available in the literature, and computes the sphere area automatically, which enables the observation of treatment response in the sphere derived from the human glioblastoma LN229 cell line. In addition, the algorithm identifies spheres with numbers to identify each one over time. The AQSA analyzes many images in 0.3 s per image with a low computational cost, enabling laboratories from developing countries to perform sphere counts and area measurements without needing a powerful computer. Consequently, it can be a useful tool for automated CSC quantification from cancer cell lines, and it can be adjusted to quantify CSCs from primary culture cells. CSC-derived sphere detection is highly relevant as it avoids expensive treatments and unnecessary toxicity.

Engineering, as a rapidly evolving field, thrives on innovation and technological advancement. Beyond the needed technical expertise, engineers require a diverse set of professional skills such as effective communication, teamwork, problem-solving, critical thinking, and management. There is also a demand for a complex set of abilities and attitudes such as ethics, integrity, adaptability, curiosity, compassion, and empathy. Engineering schools should strive to equip their students with these skills, abilities and attitudes thereby fostering the development of a ‘lifelong learning mindset’ that will prepare future professionals to rapidly adapt to actual and future, hence unknown, engineering (and personal) challenges. While addressing this responsibility, universities will necessarily face another challenge, change. This chapter is aimed to provide engineering institutions and educators effective strategies along with worldwide examples about engineering schools, programs and teaching initiatives that took this challenge. From different but complementary landscapes and viewpoints, this chapter analyses how to integrate professional skills into engineering careers and courses along with the needed compliance to local and international accreditation frameworks. Furthermore, several hints and takeaways are shared regarding how institutions and teachers can address this challenge and succeed.

Many cities have promoted decarbonized transportation modes to mitigate climate change, reduce air pollution and promote healthy behaviors. However, cyclists may be particularly exposed to higher concentrations of on-road air pollutants than other commuters due to their proximity to traffic, higher breathing rates, and prolonged commutes. In addition, there is scarce information analyzing the geographic exposure levels of cyclists in medium-sized urban agglomerations of Latin American cities. We aimed to assess cyclists' exposure to PM2.5 at the spatio-temporal level using low-cost sensors in the Mendoza Metropolitan Area, Argentina. We calculated PM2.5 inhalation doses (IDs) for different routes with distinctive characteristics, considering different age ranges and gender of cyclists. The dose was represented as temporally and spatially disaggregated exposure maps, one of the first to represent it in Latin America using this method. All link types analyzed exhibited significant differences in PM2.5 concentrations, although the most frequent concentrations were less than 5 µg m⁻³, with secondary peaks of 6.5 and 9 µg m⁻³. As expected, ID increases with age and is greater in males than in females. Our findings further reinforce the fact that route choice (busy vs. quiet) and time of day (peak vs. off-peak) appreciably affect the pollutant exposure of cyclists. All these results could be helpful in the selection of alternative cycling routes with lower PM2.5 at different hours of day but also enable us to investigate further implications of exposure to PM2.5 for the health of urban bicycle commuters.

Freshwater and groundwater are important resources for the drinking water supporting agricultural and livestock activities in the Córdoba province, Argentina. The aim of this study was to assess the physicochemical and microbiological quality of surface water (n = 14) and groundwater (n = 17) sites in the middle-lower basin of the Ctalamochita River (Córdoba, Argentina) for human and animal consumption. A total of 18 physicochemical and five microbiological parameters were evaluated to determine the hydrogeological characteristics of both water resources and their suitability for human and animal consumption using the Water Quality Index (WQI). The results indicated that Na⁺ and HCO3⁻ were the dominant cation and anion, respectively, in both water resources. Physicochemical and microbiological parameters values were compared with national and international guidelines. The WQI showed that groundwater samples exhibited poorer quality when compared to surface waters for human consumption, primarily due to elevated concentrations of major ions and the presence of total coliforms and Pseudomonas aeruginosa. Meanwhile, the WQI for animal consumption indicated that both surface and groundwater samples were suitable for this purpose. The Piper diagram showed that most of the surface water samples were classified as Na⁺–Cl⁻–HCO3⁻, while groundwater samples were classified as Na⁺–HCO3⁻. This classification highlights the hydrogeochemical differences between the two water resources. The Gibbs diagram indicates that the chemical composition of both surface and groundwater sources is primarily controlled by processes of rock-water interaction and evaporation. The findings of this study will facilitate the development of a proactive plan to safeguard and sustain water resources in the middle-lower basin of the Ctalamochita River. This can be achieved through the implementation of preventive strategies and the introduction of innovative policies.

This study presents an innovative methodology for optimal economic valuation of emissions (carbon price) under uncertainty, using Fuzzy Decision Making and Analytic Hierarchy Process to manage hierarchical variation, applied to the Argentinean production chain through Life Cycle Analysis and Demand and Supply Management. The paper presents three original contributions: 1) an economic index of marginal evaluation called Camargo Generic Intrinsic Cost, 2) optimal graphical efficiency points, regions and limits together with their economic evaluation, and 3) a computable general equilibrium model incorporating fundamental uncertainty. The results obtained, both mathematical and graphical, demonstrate the effectiveness of the methodology, providing an optimal valuation of the externality in the Argentinean production chain under uncertainty, with significant implications for both theory and practice.

Several experiments are currently carried out to measure the magnitude of the B mode polarization of the cosmic microwave background (CMB). It is a strong indicator of the presence of gravitational waves from the early universe inflationary epoch. As the average variations of the B mode components of the CMB are expected to be of the order of a few tens of nK or below, the detection of these polarized signals requires an ultrasensitive system. This article is focused on CMB detection at frequencies around the 150 GHz band of the electromagnetic spectrum, near the peak of the CMB 2.7K blackbody band of the EM spectrum. We propose a readout system for CMB cryogenic detection based on a software-defined radio (SDR) that uses frequency division multiplexing (FDM), a Goertzel channelizer and a radio frequency microwave SQUID multiplexer ($\mu$MUX) working at the cryogenic temperatures of $\approx$ 320mK. These interfaces can be used to read an array of 1024 magnetic microbolometers (MMBs) as detectors that are photon-limited for CMB detection in the band of interest. As part of the requirements for these measurements, we introduce a design of the detection and read out chain and show its expected performance and potential implementation. The proposed system can read the desired number of detectors from an array in a modular way, which allows future expansions, and its frequency division multiplexing system improves the cooling capacity of the cryostat by minimizing the amount of active cryogenic electronics. In this article, we first describe this proposed FDM readout chain and then present noise measurements of a test implementation.

Objectives We performed a systematic review and meta-analysis on long-term exposure to nitrogen dioxide (NO 2 ) and ozone (O 3 ) with mortality, to expand evidence that informed 2021 the WHO Air Quality Guidelines and guide the Health Risks of Air Pollution in Europe project. Methods We included cohorts investigating NO 2 and O 3 mortality from all-causes, respiratory diseases, chronic obstructive pulmonary disease (COPD), acute lower respiratory infections (ALRI); and NO 2 mortality from circulatory, ischemic heart, cerebrovascular diseases and lung cancer. We pooled estimates by random-effects models and investigated heterogeneity. We assessed the certainty of the evidence using the Grading of Recommendations Assessment Development approach and Evaluation (GRADE). Results We selected 83 studies for NO 2 and 26 for O 3 for the meta-analysis. NO 2 was associated with all outcomes, except for cerebrovascular mortality. O 3 was associated with respiratory mortality following annual exposure. There was high heterogeneity, partly explained by region and pollutant levels. Certainty was high for NO 2 with COPD and ALRI, and annual O 3 with respiratory mortality. Conclusion An increasing body of evidence, with new results from countrywide areas and the Western Pacific, supports certainty, including new outcomes.

In critical applications, a fault in the analog sections of a complex integrated circuit implies severe risks, compromising the mission or potentially causing harm to the people or the ambient. In this context, detecting faults during the operation in the field becomes mandatory, and built-in self-test (BIST) arises as suitable for this purpose. This paper presents an innovative user-oriented in-field BIST solution for switched-capacitor (SC) filters embedded in analog-configurable PSoC™ analog coprocessor (PSoC-AC) from Infineon Technologies AG. The BIST targets catastrophic faults in switches and deviation faults in capacitors, adopting the single-fault paradigm. The method is based on comparing the time-domain responses of the filter (for step input) against a pre-established pattern using a low computational cost signal similarity measure (SSM). The scheme implements the test signal generator and response analyzer with the resources available in the selected platform. This, along with the simple SSM used, achieves zero hardware overhead and low penalty in the memory available for the user application. The method does not require sophisticated signal processing techniques, reducing it to a simple offset removal process. The paper reports an extensive experimental fault injection and measurements campaign. Additionally, it extends the evaluations through fault simulation characterization using a low-cost filter model to establish the lowest deviation fault the method can detect in capacitors. The results show an outstanding performance, detecting all the considered catastrophic faults. Regarding deviation faults, the method detects incipient ones, which is a relevant aspect because the BIST can detect degradations at an early stage.

In this study, we comparatively analyzed traditional photocatalyst materials like TiO2 and ZnO alongside more recently considered ones, such as BiOBr and BiOI. We investigated their bactericidal activities against two control species with different types of cell walls: Escherichia coli (ATCC 25922) and Enterococcus faecalis (ATCC 25212), under identical conditions. Additionally, we assessed the adsorptive and photocatalytic capabilities of these materials for the removal and remediation of the antibiotic norfloxacin (NFX). We measured the concentration of hydrogen peroxide (H2O2) generated by the most effective bactericidal materials. The results indicate that the more modern materials, BiOBr and BiOI, exhibited higher bactericidal efficiency against both types of bacteria, as well as superior adsorptive capacity (100% for BiOI) and photocatalytic activity (100% for BiOBr) for the studied antibiotic.