The Federal University of Rio Grande (Portuguese: Universidade Federal do Rio Grande, FURG) is a public Brazilian university funded by the Brazilian federal government, located in the city of Rio Grande, Rio Grande do Sul, Brazil. Formally established on October 21, 1969, it includes 18 departments providing 31 different undergraduate courses, as well as a number of graduate programs.
We investigate the structural, electronic, and magnetic properties of HfS _2 monolayers doped with transition metals (Cr, Fe, Mn, Co) using first-principles calculations. Pure HfS _2 is non-magnetic and an indirect-bandgap semiconductor. Substitutional TM doping, especially at S-sites, induces magnetism, tunes the bandgap, and enhances the magnetic ordering temperature, making HfS _2 suitable for spintronic applications. Doping creates structural changes and introduces new electronic states, resulting in local magnetic moments for single dopants. All doped structures are confirmed to be structurally and thermally stable, as evidenced by negative formation energies and ab initio molecular dynamics simulations. Our calculations reveal significant dopant magnetic moments induced by doping, with values of approximately 1.07 _B , 1.92 _B , 1.76 _B , 2.88 _B , and 1.45 _B for Cr _Hf-site , Cr _S-site , Mn _S-site , Fe _S-site , and Co _S-site , respectively. Significant magnetic moments appear, especially for Cr, Mn, Fe, and Co at S-sites, and S-site doping is more stable than Hf-site doping. Band structure analysis shows a shift from semiconducting to half-metallic (Cr at Hf-site) or metallic (Cr at S-site) character. Extending our study to higher dopant concentration and varying the dopant separation distances, we considered two configurations. Both 2Cr-doped configurations are antiferromagnetic, with S-site doping showing stronger coupling. Two-dopant configurations at S-sites demonstrate Néel temperatures ( T_N^corr ) of 274 K (near S-sites) and 352 K (far S-sites), indicating possible long-range magnetic ordering above room temperature. Site-specific TM doping, particularly at S-sites, is a promising method to induce robust magnetism in HfS _2 monolayers for room-temperature spintronics.
Random mutagenesis combined with genome-scale analysis represents a powerful approach to uncover metabolic reprogramming in non-model microalgae. In this study we investigated the strain Desmodesmus sp. Petrobras/FURG, a thermotolerant and contamination-resistant microalga with potential for large-scale cultivation. UV mutagenesis followed by iodine-vapor screening yielded the starch-deficient mutant tN-30, which maintained wild-type growth but exhibited 2.3-fold higher neutral lipid fluorescence, 25
Banana peel ash has attracted great interest of the academic community since this agrowaste can be either transformed into value-added products or applied as an efficient promoter in chemical reactions. In particular, the use of Water Extract of Banana peel ash (WEB) in synthetic organic chemistry has provided great advances on environmental point of view. In this study, the composition of banana peel ash has been determined using Inductively Coupled Plasma Optical Emission Spectrometry and thermogravimetric analysis. Noteworthy, the banana peel ash was converted into corresponding water agrowaste extract and successfully applied as a green reaction media for the hydrophenoxylation and hydrothiolation of acetylenedicarboxylates. In general, the desired products were achieved in reasonable yields under environmentally friendly conditions. Indeed, acetylenedicarboxylates were treated with different phenols and thiols derivatives which afforded the corresponding products in 22–87
Foodborne illnesses, particularly those caused by Salmonella spp., represent a major global health concern, with S. typhimurium being a significant contributor to outbreaks. The persistence of S. typhimurium in food production environments and its resistance to conventional disinfectants highlight the need for alternative antimicrobial solutions. Essential oils (EOs) from Eucalyptus globulus (EGEO) and Cymbopogon flexuosus (CFEO) have shown antimicrobial potential against S. typhimurium, but their mechanisms of action and cytotoxic effects on eukaryotic cells require further investigation to assess their safety for food applications, particularly in situ. We evaluated cytotoxicity in erythrocytes and zebrafish liver (ZF-L) cells using hemolysis (HA), MTT, and NR uptake assays. Additionally, we investigated the antimicrobial behavior of EGEO and CFEO against S. typhimurium ATCC 14,028 through MIC/MBC tests, time-kill assays, and a newly designed TSI-adapted test to assess the EOs’ impact on bacterial metabolism. An in situ experiment was also conducted to evaluate the preservative effects of EGEO and CFEO on pork sirloin contaminated with an infectious dose of S. typhimurium and treated with EO-based brines for 7 days under refrigeration. We monitored the presence of Salmonella spp., as well as pH, calcium (Ca²⁺), and magnesium (Mg²⁺) concentrations in the brined samples. Results indicated that CFEO was hemolytic above 0.73 mg/mL and EGEO above 0.45 mg/mL. The MTT assay showed that CFEO did not impair mitochondrial function from 2.941 mg/mL and EGEO from 14.36 mg/mL. NR uptake assay showed that both EOs did not impaired lysossomal function in ZF-L. The MICs and MBCs for CFEO and EGEO were 0.37 mg/mL and 1.79 mg/mL, respectively. Time-kill assays revealed bactericidal effects for CFEO at 4x and 2x MIC within 6 h, while EGEO showed a bactericidal effect only at 4x MIC. The EO-TSI agar assay demonstrated that EGEO inhibited sugar fermentation and sulfur metabolism, while CFEO impacted peptone oxidation and protein metabolism. In situ analyses showed CFEO caused more significant changes in color and odor of the pork samples than EGEO, while both maintained pH levels around 6. Ca²⁺ and Mg²⁺ levels were lower in CFEO-treated samples. Microbiological data confirmed the absence of Salmonella spp. in all samples except for two in the CFEO-brine group. None of the samples showed signs of autolysis or putrefaction, suggesting that both CFEO and EGEO, particularly EGEO, are feasible alternatives as food preservatives, depending on the desired application.
Persistent organic pollutants (POPs) are widespread contaminants that bioaccumulate in the food web, posing risks to wildlife, especially top predators. This study investigates the occurrence of POPs in liver tissues of 23 Magellanic Penguins (Spheniscus magellanicus) stranded along the Brazilian coast from June to September 2017. We analyzed concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (DDTs, Drins, mirex, endosulfans), and hexachlorobenzene (HCB). POPs were detected in all samples. PCBs and DDTs showed the highest concentrations, with PCBs ranging from < LOD to 199.4 ng g−1 ww (mean: 57.2 ± 49.0 ng g−1 ww), showing a declining trend compared to previous reports. DDT metabolites, especially p,p′-DDE, remained persistent in the samples. HCB was found in 70
