The State University of Maringá (Portuguese: Universidade Estadual de Maringá, UEM) is a public university whose main campus is in Maringá, Paraná, Brazil. It was founded in 1970 and recognized in 1976 by the Federal Government of Brazil. Its academic population is estimated in 18,000 people among professors, undergraduates, graduate students and manager technicals.UEM has 48 undergraduate courses and about 25 graduate programs. The university has 5 campuses in Maringá, Goioere, Cianorte, Cidade Gaúcha and Umuarama, all cities located in Paraná state..
The main purpose of this paper is to investigate the global well-posedness and orbital stability of odd periodic traveling waves for the ϕ^4-equation in the Sobolev space of periodic functions with zero mean. We establish new results on the global well-posedness of weak solutions by combining a semigroup approach with energy estimates. As a consequence, we prove the orbital stability of odd periodic waves by applying a Morse index theorem to the constrained linearized operator defined in the Sobolev space with the zero mean property.
Hydrochars were synthesized from cellulose and nanocellulose, and their structural, chemical, textural, and morphological evolutions were systematically investigated. Unlike most recent studies focused on a single cellulose-based precursor, isolated HTC parameter, catalytic/additive-assisted route, or specific application, this work provides a comparative multi-variable evaluation of α-cellulose- and nanocellulose-derived hydrochars. For α-cellulose-derived hydrochars (HC), the effects of temperature, residence time, precursor loading, and agitation speed were examined, whereas for nanocellulose-derived hydrochars (HN), the influence of temperature and initial pH was evaluated. The resulting materials were characterized by elemental analysis, FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, N2 adsorption–desorption measurements, while multivariate statistical tools were used to correlate processing conditions with compositional, structural, and fuel-related properties. HC showed progressive carbonization with increasing HTC severity, as indicated by decreasing the H/C and O/C atomic ratios, higher carbon content, and improved higher heating value (HHV). FTIR spectra indicated the formation of oxygenated functional groups and aromatic domains, while XRD patterns showed broad amorphous halos typical of non-graphitizing carbon. SEM images revealed irregular carbonaceous matrices containing micrometer-sized spherical particles. For HN, the influence of temperature (200–260 °C) and initial pH (3.3 and 12) was examined. The CHN elemental analysis showed that the acidic initial reaction medium favored dehydration, deoxygenation, and carbon enrichment, whereas the initially alkaline condition delayed carbonization. Overall, this systematic comparison demonstrates how precursor type and HTC processing variables modulate hydrochar yield, composition, structure, morphology, and fuel-related properties, providing a clearer basis for the rational design of cellulose- and nanocellulose-derived hydrochars.
Metal contamination in aqueous effluents remains a critical environmental challenge due to the toxicity, persistence, and bioaccumulation of heavy metals such as Pb²⁺ and Cu²⁺. In this study, poly(vinylidene fluoride) (PVDF)/montmorillonite Clay nanofibrous membranes were produced by the solution blow spinning (SBS) technique and evaluated for heavy metal removal through adsorption and membrane filtration processes. Membranes containing different Clay loadings were successfully fabricated, forming micro- and nanofibrous structures suitable for water treatment applications. Batch adsorption experiments indicated moderate metal removal efficiencies, which were strongly dependent on Clay content and contact time. The adsorption kinetics were better described by the pseudo-second-order model, while equilibrium data were consistent with the Langmuir isotherm, suggesting monolayer adsorption on active sites associated with the Clay phase. Filtration experiments demonstrated significantly higher removal efficiencies, with membranes containing 10 wt
The hawksbill turtle (Eretmochelys imbricata), classified as critically endangered, has a global distribution in tropical and subtropical waters. The Brazilian colony is essential for the species’ conservation, as it is the largest remaining nesting population in the South Atlantic. Furthermore, it exhibits the highest hybridization rate worldwide. This study investigated the foraging population in the state of São Paulo (Southeast Brazil), which previously lacked genetic data, using mitochondrial DNA (D-loop) analysis of immature individuals. Hybrids between E. imbricata and Caretta caretta were identified, along with hawksbill haplotypes previously recorded in southern South America and a novel haplotype for the region. The absence of Indo-Pacific haplotypes suggests the influence of the Benguela Current, which reduces genetic diversity compared to the Brazilian Northeast and the Caribbean. The results indicate that the foraging individuals in southern South America predominantly originate from the Brazilian Northeast, with some influence from the Caribbean, highlighting the role of the Brazil Current in the dispersal of hatchlings. These findings emphasize the importance of Southeast Brazil for hawksbill turtle conservation and its relevance to the species’ life cycle across different regions.
Endophytic fungi are recognized as important sources of bioactive specialized metabolites. In this study, six compounds were isolated from cultures of endophytic fungus Epicoccum sorghinum (DF1) associated with Disynaphia filifolia, including a new aliphatic amide (1) identified as 2-hydroxy-N-(4’-oxohexan-2’-yl)-propanamide and other known compounds 2,3-dihydro-2-hydroxy-2,4-dimethyl-5-trans-propenylfuran-3-one (2), 2,3-dihydro-2-hydroxy-2,4-dimethyl-5-propylfuran-3-one (3), cyclo-L-Pro-L-Phe (4), cyclo-L-Pro-L-Tyr (5) and tetrahydroaltersolanol B (6). The structures were established by spectroscopic analysis and comparison with related compounds reported in the literature. The cytotoxic activities of the isolated compounds were evaluated against human prostate carcinoma (PC-3), cervical carcinoma (HeLa), and non-tumorigenic keratinocyte (HaCaT) cell lines. Among the tested compounds, cyclo-L-Pro-L-Phe showed the most pronounced cytotoxic effects against PC-3 and HeLa cells. The new amide derivative (1) exhibited weak activity toward PC-3 cells and no detectable activity against HeLa cells, while presenting low cytotoxicity toward HaCaT cells. The remaining compounds displayed weak to moderate cytotoxic activity, with PC-3 cells being the most sensitive overall. These findings contribute to the chemical characterization of metabolites produced by E. sorghinum, isolated for the first time from D. filifolia, and highlight its potential as a source of structurally diverse compounds with biological activity to be explored.
