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Integral Closure, Whitney Stratification, and Bi-Lipschitz Invariants on Toric Varieties
(Universidade Federal de São Carlos, 2026-06-23) Araújo, Amanda Santos; Silva, Thiago Filipe da; https://lattes.cnpq.br/5049713215002090; Dalbelo, Thaís Maria; https://lattes.cnpq.br/8872438977518818; https://lattes.cnpq.br/3001239481307791; Oréfice Okamoto, Bruna; Hernandes, Marcelo Escudeiro; Fernandes, Alexandre Cesar Gurgel; Bivià-Ausina, Carles; https://lattes.cnpq.br/6824383277098012; https://lattes.cnpq.br/1501547381354779; https://lattes.cnpq.br/8791056897839415; https://orcid.org/0000-0003-0784-3353
This work, we investigate the interation between combinatorial structures, algebraic and geometric properties, and metric aspects in Singularity Theory, with affine toric varieties as the main setting. The central objective is to develop an approach that allows one to describe invariants and properties of singularities using combinatorial data associated with semigroups and Newton polyhedra. First, we study the integral closure of non-degenerate ideals in rings of analytic functions associated with affine toric varieties. We show that, under suitable non-degeneracy conditions with respect to the Newton polyhedron, the integral closure of such ideals admits a precise combinatorial description, extending classical results known in the regular case. Next, we investigate toric surfaces in C3 and construct a Whitney stratification adapted to their combinatorial structure. We prove that, under appropriate conditions, it is possible to obtain a stratification with a reduced number of strata while preserving Whitney regularity conditions. Finally, we analyze the bi-Lipschitz invariance of local invariants of singularities. We establish algebraic conditions ensuring the invariance of the Łojasiewicz exponent and the local Euler obstruction. The obtained results show that toric varieties constitute a particularly suitable setting to translate analytic, algebraic, and metric phenomena into combinatorial terms, providing new tools for the systematic study of singularities in more general contexts.
Dados ambientais e biológicos da bacia hidrográfica do Rio Ribeira de Iguape
(Universidade Federal de São Carlos, 2026-06-23) Cetra, Mauricio; https://lattes.cnpq.br/6775493342513120; https://orcid.org/0000-0002-3902-0661
Nanopartículas para o tratamento do câncer cervical
(Universidade Federal de São Carlos, 2026-06-23) Coury Ribeiro, Guilherme; Leite, Ana Elisa Tognoli; https://lattes.cnpq.br/3170931739485037; Batista, Ana Paula de Lima ; https://lattes.cnpq.br/7345615178834792
Cervical cancer represents a public health problem in Brazil, frequently characterized by diagnoses in advanced stages that compromise the clinical prognosis and raise the costs of the public healthcare system. Treatment for advanced carcinomas may involve the systemic administration of cisplatin, a chemotherapeutic agent with excellent pharmacological mechanics, whose therapeutic index is, however, limited by the occurrence of severe systemic side effects and the development of tumor resistance. Faced with this scenario, nanomedicine has studied ways to optimize drug targeting specifically to the tumor microenvironment. This work introduces the concepts of nanomedicine and presents a comparative analysis of three nanoplatforms documented in the scientific literature for the delivery of cisplatin in HeLa cervical carcinoma cell lines. The studied works involve estrone-targeted PEGylated liposomes, polymeric PLGA nanoparticles in a co-delivery regimen, and mesoporous silica nanoparticles functionalized with carboxylic groups. The results revealed that the chemical nature of each matrix outlines distinct biological and physicochemical profiles. ES-SSL-DDP liposomes showed the highest in vitro cytotoxic potency, increasing efficacy by 169.6-fold compared to the free drug, driven by active targeting of estrone via estrogen receptors in HeLa cells. In turn, MSNs-C demonstrated quantitative superiority in loading parameters, with an approximate encapsulation efficiency of 63.7% and a loading capacity of 11.3%. In addition, they exhibited highly responsive release at more acidic pH, ensuring drug protection under neutral physiological conditions. PLGA nanoparticles enabled a synergistic therapeutic effect in inducing apoptosis when combined with silibinin, although they lack direct cellular uptake data. Regarding colloidal stability, the PLGA polymeric nanoparticle exhibited the highest negative zeta potential module of -59 mV. In summary, the analyzed nanocarriers demonstrate remarkable potential to overcome the limitations of classical chemotherapy.
Análise da influência comportamental e ambiental na regulação térmica de botos-cinza utilizando modelos mistos
(Universidade Federal de São Carlos, 2026-06-23) Jordão, José Rafael; Montoril, Michel Helcias; http://lattes.cnpq.br/9993502064983663; https://orcid.org/ 0000-0001-8431-3087; http://lattes.cnpq.br/8665846117933773; https://orcid.org/0009-0006-5313-2332
Thermoregulation in aquatic mammals involves physiological, anatomical, and behavioral processes that contribute to heat conservation and dissipation in environments characterized by high rates of thermal exchange. In this study, the apparent temperature of Guiana dolphins (Sotalia guianensis) inhabiting an estuarine environment was analyzed using thermographic data associated with environmental, behavioral, and body-region variables. The dataset had a hierarchical and unbalanced structure, with repeated observations for the same individuals, which motivated the use of mixed-effects models with a random intercept. Initially, univariate and bivariate descriptive analyses were conducted to characterize the distribution of apparent temperature and identify patterns associated with water surface temperature, season, time of day, behavior, and body region. Gaussian and Gamma formulations were then compared, and the Gaussian mixed-effects model was selected as the reference model based on information criteria. Residual diagnostics indicated that the relationship between water temperature and apparent temperature was not adequately represented by a strictly linear term; therefore, the final model included polynomial terms up to the third degree for centered water temperature. The results indicated a strong influence of water surface temperature and seasonality on apparent temperature, as well as effects associated with behavior and the interaction between time of day and season. Sensitivity analyses, including nonparametric bootstrap resampling at the individual level, supported the stability of the main effects, although some contrasts among body regions showed greater uncertainty due to the unbalanced sample sizes. It is concluded that mixed-effects models provide an appropriate framework for analyzing thermographic data with a hierarchical structure, allowing environmental, behavioral, and individual factors to be jointly incorporated into the assessment of apparent thermal variation in Guiana dolphins.
Materiais à base de ZnO na degradação fotocatalítica de antibióticos: uma revisão sobre fundamentos e aplicações
(Universidade Federal de São Carlos, 2026-06-23) Farias, Júlia Mendes; Silva, Elson Longo da; http://lattes.cnpq.br/9848311210578810; https://orcid.org/0000-0001-8062-7791; Bernardi, Maria Inês Basso; http://lattes.cnpq.br/7998391975397420; https://orcid.org/0000-0001-7220-078X; http://lattes.cnpq.br/7220310771709868
The increasing presence of antibiotics in aquatic environments has raised growing concern due to their environmental persistence, ecotoxicological potential, and contribution to the spread of antimicrobial resistance. Conventional water and wastewater treatment processes often exhibit limited efficiency in removing these compounds, allowing their continuous release into the environment. In this context, Advanced Oxidation Processes (AOP) have emerged as promising alternatives because of their ability to generate reactive species capable of degrading persistent organic contaminants. Among these technologies, heterogeneous photocatalysis has attracted considerable attention due to its high degradation efficiency and potential application in water treatment. Among the semiconductors employed in this process, zinc oxide (ZnO) stands out because of its combination of favorable properties, including photocatalytic activity, chemical stability, and low cost compared with other semiconductor materials. The present study aimed to review the literature on the application of ZnO-based materials for the photocatalytic degradation of antibiotics in aqueous media. The main aspects addressed include the occurrence of these contaminants in the environment, the limitations of conventional treatment methods, the fundamentals of AOP and heterogeneous photocatalysis, as well as the structural, morphological, and optical properties of ZnO associated with its photocatalytic performance. Strategies for improving the material, including doping and heterojunction formation, were also discussed to enhance its photocatalytic efficiency. The reviewed studies demonstrate that ZnO-based materials show significant potential for the degradation of different classes of antibiotics, achieving high removal efficiencies when properly modified and applied under suitable operating conditions. Therefore, ZnO and its composites represent promising alternatives for the development of sustainable technologies aimed at the treatment of water contaminated with emerging contaminants.