Smart packaging with biodegradable polymers has emerged as a response to food challenges in a modern society, in terms of environmental impact, innovation, quality and safety. For that reason, it is important to design and understand smart materials that may have high potential for application in food science. In this work, films based on potato starch reinforced with six different levels of content of silver nanoparticles (AgNp) were produced by casting with the aim of evaluating its potential use as a material for smart packaging. The films were evaluated in terms of shape memory stimulated by temperature, antibacterial activity (against Salmonella typhimurium), thermo-mechanical and physicochemical tests. Addition of AgNp in potato starch films modified the assembly of polymer chains, with changes observed in superficial water affinity, thickness, and shape memory. Nanocomposites films showed antibacterial activity against Salmonella typhimurium, and they were efficient at blocking ultraviolet light and extending this protection to visible light, unlike control samples without nanoparticles. AgNp mechanically reinforced potato starch films, showing an increase in the elastic modulus greater than 200%. Furthermore, the film intermediate content of AgNp exhibited higher thermal stability than the control potato starch film, increasing its thermal degradation temperature by 15 °C. Additionally, an enhanced shape memory response of potato starch films is observed at an activation temperature of 80 °C for the formulation with the lowest AgNp content. Therefore, establishing the amounts of AgNp in potato starch allows us to modulate the properties of the nanocomposite, depending on the requirements of smart packaging.
Background Multiple myeloma (MM) results in significant mortality and disability; however, long-term trends and forecasts specific to Mexico remain insufficiently characterized. Methods A secondary analysis of Global Burden of Disease (GBD) estimates for Mexico (1990–2023) was conducted. Incidence, prevalence, deaths, DALYs, YLLs, and YLDs were summarized as counts and age-standardized rates (per 100,000) with 95% uncertainty intervals. Temporal trends were examined using Joinpoint regression. Forecasts for 2024–2040 were generated using SPSS Expert Modeler and evaluated using a 5-year retrospective holdout analysis. To contextualize burden by development, correlations between national SDI and age-standardized outcomes were analyzed. Results Incident MM cases increased from 457.58 in 1990–1,795.96 in 2023, and the age-standardized incidence rate rose from 1.04–1.28 per 100,000. Prevalent cases increased from 941.58–4,484.50, with an increase in age-standardized prevalence from 2.03–3.16 per 100,000. Age-standardized mortality changed modestly. DALYs were mainly driven by YLLs, while YLDs increased over time; substantial state-level heterogeneity was observed in 2023. SDI correlated positively with burden indicators, most strongly with age-standardized prevalence and YLD rates. Retrospective validation showed that the Brown models did not outperform a naïve benchmark and had low prediction interval coverage. Consequently, long-term extrapolations were considered exploratory. Conclusions MM burden in Mexico has increased over the past three decades. While the mortality-dominated burden remains stable, the disability burden is growing. Descriptive development-related gradients and geographic heterogeneity suggest areas of variation relevant to service planning. Findings should be interpreted as patterns in GBD-estimated burden trajectories rather than directly observed surveillance trends.
This paper presents a robust observer-based proportional-derivative (PD) control strategy for a two-dimensional crane system with varying rope length to attenuate payload swing. The proposed control architecture integrates a PD controller, an Extended State Observer (ESO), a fuzzy compensation mechanism, and a coupling function that links the translational motion to the payload swing dynamics, thereby improving oscillation attenuation during transportation tasks. An energy-like function framework is developed to systematically derive the fuzzy compensation mechanism and establish practical stability properties of the tracking-error dynamics. The proposed controller is derived from crane dynamics for analysis. However, its real-time implementation does not require explicit knowledge of the system parameters. To assess its effectiveness, the proposed methodology is compared with three robust control approaches reported in the literature. Extensive numerical simulations demonstrate satisfactory tracking performance, effective reduction of payload swing, and robustness to parameter uncertainties, measurement imperfections, and external disturbances. Finally, experimental results obtained on a real overhead crane platform validate the practical applicability of the proposed methodology, showing reliable closed-loop performance under large initial deviations, repeated external perturbations, and implementation uncertainties.
The thermal reactivity of kerogen is primarily determined by skeletal bond strength and intermolecular interactions. To elucidate this, we established a multiscale framework integrating high-fidelity molecular modeling, Density Functional Theory (DFT), Reactive Molecular Dynamics (ReaxFF) simulations, and nonisothermal kinetic analysis. Three-dimensional molecular models for Type II1, II2, and III kerogens were constructed under rigorous experimental constraints. DFT calculations revealed significant electronic structural heterogeneity: Type III kerogen exhibited a high average skeletal bond order of 1.17 and a charge standard deviation of 0.0918, indicating pronounced structural rigidity and strong electrostatic polarization. In contrast, Type II1 kerogen was characterized by a flexible aliphatic content exceeding 54% and a radical attack index (f 0) more than four times that of Type III, implying abundant reactive sites. Iso-conversional kinetic analysis yielded systematically increasing pyrolysis activation energies (Ea) for Type II1, II2, and III kerogens, measured at 234.34, 240.67, and 247.10 kJ/mol, respectively. General correlation analysis indicates that macroscopic Ea scales positively with skeletal bond order and electrostatic polarization, while negatively with flexible domain abundance and radical initiation capacity. These findings indicate that thermal stability is dominated by skeletal rigidity and electrostatic confinement; conversely, reactivity is driven by aliphatic flexibility and radical generation potential. Guided by these electronic properties, strategies utilizing polarity-matched hydrothermal fluids and active hydrogen capping are proposed to overcome high energy barriers and suppress condensation, mechanisms further validated by ReaxFF simulations. These findings provide molecular-level insights for optimizing in-situ kerogen conversion.
Smart packaging with biodegradable polymers has emerged as a response to food challenges in a modern society, in terms of environmental impact, innovation, quality and safety. For that reason, it is important to design and understand smart materials that may have high potential for application in food science. In this work, films based on potato starch reinforced with six different levels of content of silver nanoparticles (AgNp) were produced by casting with the aim of evaluating its potential use as a material for smart packaging. The films were evaluated in terms of shape memory stimulated by temperature, antibacterial activity (against Salmonella typhimurium) , thermo-mechanical and physicochemical tests. Addition of AgNp in potato starch films modified the assembly of polymer chains, with changes observed in superficial water affinity, thickness, and shape memory. Nanocomposites films showed antibacterial activity against Salmonella typhimurium , and they were efficient at blocking ultraviolet light and extending this protection to visible light, unlike control samples without nanoparticles. AgNp mechanically reinforced potato starch films, showing an increase in the elastic modulus greater than 200%. Furthermore, the film intermediate content of AgNp exhibited higher thermal stability than the control potato starch film, increasing its thermal degradation temperature by 15 °C. Additionally, an enhanced shape memory response of potato starch films is observed at an activation temperature of 80 °C for the formulation with the lowest AgNp content. Therefore, establishing the amounts of AgNp in potato starch allows us to modulate the properties of the nanocomposite, depending on the requirements of smart packaging.
