Located in the city of Maceió, the Federal University of Alagoas (Portuguese: Universidade Federal de Alagoas, UFAL or Ufal) is the major university in coastal state Alagoas and one of the main research centers in Brazilian north eastern region (one of the five regions of Brazil). It is located very near the city's airport..
Sb2-xMnxSe3 diluted magnetic semiconductor nanocrystals (NCs) were grown in situ within an SNAB borosilicate glass matrix by the fusion-nucleation method. X-ray diffraction, transmission electron microscopy, and Raman spectroscopy confirmed the formation of Mn-containing NCs with the orthorhombic Sb2Se3 structure, average diameters of approximately 6.3 nm, and no detectable secondary crystalline phases. Increasing Mn concentration induces lattice expansion and Raman-mode blueshifts, consistent with substitutional incorporation of Mn2+ into distorted pseudo-octahedral sites. Optical absorption reveals continuous bandgap narrowing from 3.02 to 2.26 eV, associated with Mn-induced electronic band restructuring involving a dominant CBM downshift of approximate to 0.65 eV and a smaller VBM upshift of approximate to 0.11 eV. Photoluminescence (PL) reveals two coexisting emission channels. The green band near 540 nm is assigned to the 4T1(4G)-> 6A1(6S) transition of Mn2+ ions in tetrahedral sites of the glass matrix, whereas the red-to-near-infrared PLdef. band, shifting from 1.79 to 1.68 eV, is associated with defect-related recombination in the Sb2-xMnxSe3 NCs. Electron paramagnetic resonance (EPR) distinguishes Mn2+ in pseudo-octahedral NC sites and tetrahedral glass sites, with hyperfine constants of approximate to 8.16 and approximate to 7.78 mT, respectively. The PL and EPR results demonstrate that thermal treatment promotes incorporation of Mn2+ into the growing Sb2Se3 NCs, while a residual Mn2+ population is retained in tetrahedral sites in the glass matrix. This Mn2+ partitioning between pseudo-octahedral sites in the Sb2-xMnxSe3 NCs and tetrahedral sites in the borosilicate glass matrix reveals the origin of the dual-emission in the Sb2-xMnxSe3 NCs/SNAB composite.
Tests are essential for ensuring code quality in software development. However, poor implementation practices can compromise the maintainability and evolution of test code, leading to additional costs and effort. These practices, known as test smells, have been the focus of numerous studies that expanded the catalog of known test smells. Despite this progress, little attention has been given to examining test smells from the perspective of programming languages, particularly their relationship with specific languages or test frameworks. As a result, researchers and practitioners have proposed various approaches and tools to detect and refactor the same test smells across different languages. In this work, we address this gap by analyzing test smells in the literature from a programming language perspective. We conducted a systematic mapping study, gathering data from papers published up to August 2025, examining 117 papers. We identified the most prevalent languages and frameworks associated with test smells, the most common test smells in each language, refactorings for addressing test smells, datasets of test smells, the criticality of specific test smells, and a collection of tools to detect or refactor test smells for various languages and frameworks. Our results show that while many test smells have been addressed, research remains limited to a few languages and frameworks. We also found datasets and detection/refactoring tools for some languages and analyzed the criticality of frequently mentioned test smells. This study highlights the need to expand research to more languages and develop more universal solutions.
Tetracycline antibiotics are widely used in cattle to treat and prevent bacterial infections, including enteric and systemic diseases. They are also used to treat bovine mastitis, which affects milk quality and productivity. Improper or excessive use can leave antibiotic residues in animal products, posing a public health risk and promoting antimicrobial resistance. In this study, we examined oxytetracycline (OTC) residues in raw cow’s milk from the semi-arid region of Alagoas, Northeastern Brazil. We used a paper-based microdevice (μPAD) with copper nanoparticles (CuNPs). Milk samples were collected from all four teats of 30 randomly selected Girolando cows across different rural properties. The method performed well, showing a linear response from 1 to 25 μg mL⁻1 and a high correlation coefficient (R2 = 0.99946). The recovery rate was 94.70
In Brazil, there are 41 food supply centers, and 72 warehouses distributed in 22 Federation Units, which generate about 42,000 tons of organic waste monthly, normally destined for landfills. This study investigated the energy use of these residues for different inocula and liquid biofertilizer to increase biomethane production in the anaerobic digestion of fruit and vegetable residues (VWF). The experiment used waste collected from the CEASA-PE supply center, which generates about 990 tons of organic waste per month. Different inoculum mixtures, composed of digestate, rumen liquid and anaerobic domestic sludge, were tested in combination with a liquid biofertilizer co-product. The application of the experimental design of mixtures based on the centroid simplex method and the response surface methodology, allowed us to systematically evaluate the interactions between the inocula and identify optimal proportions to produce biomethane. The results revealed that the combination of 25% biofertilizer and 75% rumen liquid provided the highest biomethane production, reaching 453.1 Nml/gSV, an increase of approximately 4 times in relation to the positive control. On the other hand, the mixture of 25% biofertilizer and 75% digestate resulted in a significantly lower yield of 256.7 Nml/gSV, about 2.5 times the control. In addition, based on the estimated amount of VWF of CEASA-PE, a potential for generating electricity from biomethane of 124 MWh/month\(\:{\eta\:}_{elec}\) was calculated, evidencing the energy and economic feasibility of the application of this technology for the use of urban organic waste.
Chitin is the second most abundant polysaccharide in nature and constitutes a key structural component in the cell wall of fungi and invertebrate exoskeletons. Chitinases produced by Antarctic organisms have demonstrated high catalytic efficiency, being promising tools for sustainable biotechnological processes. Therefore, the objective of this study was to identify the genes responsible for chitin degradation in the genomes of two Antarctic Arthrobacter strains, as well as to evaluate their biotechnological potential. Whole-genome sequencing followed by phylogenomic analysis revealed that both strains 492 and 285 belong to the species Arthrobacter psychrochitiniphilus. Genome assembly and annotation confirmed the genetic potential for chitinase production, showing that both bacteria possess the gene encoding type C chitinase (Chi C) from the GH18 family. Genomic comparative analysis revealed that they possess a total of eleven genes related to glycoside hydrolases (GH) and carbohydrate-binding modules (CBM), highlighting GH13 and GH65. Arthrobacter psychrochitiniphilus 492 was classified as psychrophilic, while A. psychrochitiniphilus 285 was classified as mesophilic-psychrotolerant. The enzyme production by A. psychrochitiniphilus 285 was 19.9 U/L, in 96 h at 15 °C, and the chitinase showed activity against the Aspergillus sp. series nigri CBMAI 1846, indicating promising potential for the formulation of bioinoculants and sustainable agriculture.
