Universidade Federal de Alagoas

This study investigates the structural, optical, and magnetic properties of Ni²⁺-doped TiO₂ nanostructures (1.0–10.0 wt%) synthesized via an acidic sol–gel route. Dopant-induced lattice modifications are primarily expressed through microstructural strain, lattice parameter distortion, and phonon softening rather than macroscopic lattice defects visible by TEM. X-ray diffraction and Rietveld refinement reveal systematic shifts of the anatase (101) peak, lattice contraction, and increasing compressive strain with Ni incorporation, as confirmed by Williamson–Hall analysis. Raman and electron paramagnetic resonance (EPR) spectra indicate oxygen vacancy formation and localized electronic states. Optical absorption and Tauc analysis show progressive bandgap narrowing, while crystal field theory (CFT) confirms Ni²⁺ ions occupying both octahedral and tetrahedral coordination environments. EPR signals further evidence Ni²⁺ magnetic centers and Ti³ ⁺/oxygen vacancy-related species. These results demonstrate that defect-mediated lattice distortion governs the optoelectronic and magnetic tuning of Ni-doped TiO₂, offering insights for advanced photocatalytic and spintronic material design.

This study assesses the performance of a regional WRF configuration used operationally by SIMEPAR (SIWRF) and a set of MPAS experiments at 5-km grid spacing over southern Brazil to predict four recent severe weather events. MPAS is tested using a 200-5 km global variable-resolution (VR) mesh with two physics suites—Mesoscale Reference (MR) and Convection-Permitting (CP)—and two sources of initial conditions — NCEP-GFS and ECMWF-IFS forecasts. Skill is evaluated with respect to 48-h accumulated precipitation (correlation, bias, RMSE), hourly precipitation (fractions skill score; FSS, and QPF measures), radar reflectivity (FSS), near-surface variables (MAE, Taylor diagrams), and vertical soundings (bias, RMSE). Across events, MPAS generally outperforms SIWRF for precipitation, with CP physics suite often reducing positive bias relative to MR, while SIWRF tends to underestimate totals during the heaviest events. Notably, MR-IFS achieves the highest correlation for the event dominated by a long-lived, organized convective system, whereas CP-IFS provides the most balanced metrics in two other cases, including the coastal event, consistent with improved placement and intensity of convection. SIWRF exhibits the lowest skill for radar reflectivity, while MPAS shows event-dependent gains, particularly for MR-IFS and CP-GFS. Analysis of convective parameters reveal that MR configurations produce higher median CAPE and 0–3-km SRH than CP and SIWRF, implying more favorable storm environments. These results highlight event-dependent sensitivity to physics and initial conditions and suggest that tailoring MPAS configuration to event features (e.g., favoring CP physics for coastal/diurnally forced convection and MR physics for strongly forced organized systems) may improve forecasts, but this inference is preliminary and requires broader testing (larger case set, data assimilation, ensemble and operational-runtime evaluation) before operational adoption. • First comparison of MPAS and operational WRF for severe weather in southern Brazil. • MPAS with 200-5 km global VR mesh often outperformed 5-km regional WRF. • MPAS precipitation skill and biases strongly depend on physical options and IC source. • MPAS forecasts improved when initialized with ECMWF-IFS ICs rather than NCEP-GFS.

Work-related musculoskeletal disorders (WMSDs) are a prevalent issue, associated with a complex interaction of occupational risk factors that can be linked to lower quality of work life (QWL). While these relationships are well-established, it remains unclear how age-based differences mediate them, as younger and older workers may respond differently to various workplace hazards. Understanding these age-specific pathways is crucial for developing targeted interventions. This study aimed to investigate the relationships between occupational risk factors, WMSDs, and QWL across different age groups to identify key differences and inform ergonomic practice. A sample of 312 workers, divided into young (under 45 years) and older (45 years and above) groups, was analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM) to test hypotheses linking biomechanical, psychosocial, and organizational risk factors to WMSDs and QWL. Significant differences were observed between age groups. Tight deadlines were associated with occupational stress (OS) only in older workers, whereas WMSDs were significantly associated with lower QWL only among younger workers. Physical job demands and OS were associated with WMSDs in both groups, and OS was related to their QWL. The findings indicate that worker age significantly influences how occupational risks are associated with WMSDs and QWL, and that these associations are not uniform. This study validated a model that examined the relationships among occupational risk factors, WMSDs, and QWL across age groups. The model demonstrated robust psychometric properties, enabling the identification of significant differences between young and older workers.

Candidiasis, caused by yeasts of the Candida genus, is increasingly characterized by a high prevalence of clinical isolates resistant to conventional antifungals, rendering the development of novel therapeutic strategies paramount. Drug repurposing has emerged as a key strategy, utilizing established pharmaceuticals for indications beyond their original design; notably, haloperidol (HAL) has shown promising antimicrobial potential. In this context, the present study evaluates the activity of haloperidol, both as a monotherapy and in combination with conventional antifungals, against fluconazole-susceptible and fluconazole-resistant Candida spp. clinical strains. Furthermore, we investigate the underlying mechanisms of its antifungal action. Experimental approaches included broth microdilution assays to determine the Minimum Inhibitory Concentration (MIC), checkerboard assays for synergistic analysis, and cellular assessments via flow cytometry and fluorescence microscopy. Haloperidol displayed MIC values between 26.67 and 256 μg/mL. Synergistic interactions were identified between haloperidol and the azoles fluconazole and itraconazole, alongside a 2.5 % synergy rate with amphotericin B. Additionally, mechanistic assays confirmed that haloperidol induces programmed cell death (apoptosis) in C. albicans and C. auris strains. The oxidative stress caused by haloperidol altered Ca2+ homeostasis, followed by mitochondrial membrane depolarization, reduced ATP production, cytochrome c release into the cytosol and metacaspase activation, reduced viability, phosphatidylserine externalization, promoted fragmentation, damage and methylation of DNA. It also induced expression of genes related to oxidative stress. It reduced mitochondrial depolarization and decreased the reduction of glutathione (GSH), causing morphological alterations. The results suggest the apoptotic pathway as the main antifungal mechanism of haloperidol.

Dihydroquinazolin-4(3H)-imines have emerged as a promising scaffold for developing novel antimycobacterial agents. Here, we integrated QSAR modeling, in vitro screening, molecular dynamics (MD), binding free-energy calculations, and in vivo toxicity assessment to identify potent inhibitors against Mycobacterium tuberculosis (Mtb). Four QSAR models demonstrated strong internal and external reliability (R2>0.68; Q2LOO>0.62; R2extup to 0.82). Additional validation parameters met recommended thresholds (Q2-F1/F2/F3≥0.72; CCCext≥0.88; r2m aver≥0.72; r2m delta: 0.04), and Williams plots confirmed that all predictions fell within the applicability domain (h*: 0.286). Biological assays identified 11 active compounds, with MIC values ranging from 25 to 200μM. Compound 2c (p-methylphenyl derivative) and 3d (m, p-dichlorophenyl analog) were the most potent, displaying MIC values of 50 and 25μM, respectively. MD simulations revealed stable and specific interactions with Eis, an acetyltransferase linked to kanamycin resistance. Compound 2c exhibited a mean ΔGbind of -52.19±3.21kcal/mol, while 3d showed a more favorable ΔGbind of -73.15±3.16kcal/mol, consistent with its superior in vitro potency. Distinct interaction profiles-especially the engagement of Tyr126 and hydrophobic clusters-help explain their differential affinities. Moreover, both leads demonstrated low to moderate in vitro cytotoxicity against HepG2 cells at the concentrations evaluated. In vivo acute toxicity in Zophobas morio indicated LD₅₀ values of 500mg/kg for 2c and 100mg/kg for 3d, with transient tremors and melanization observed only for 3d. Since compound 2c exhibited a safer in vivo toxicity profile, this compound was investigated for its association with antimicrobial drugs. These compounds were validated as promising anti-TB candidates, supported by robust QSAR predictivity, favorable binding energetics, and measurable in vitro and in vivo toxicity profiles, reinforcing their potentials for further optimization.

The COVID-19 pandemic disrupted all healthcare systems in Brazil, including HIV/AIDS surveillance and control. This study aimed to quantify the pandemic’s impact on HIV case notification counts in the state of Bahia, located in northeastern Brazil, from 2015 to 2022. We conducted an observational time-series analysis of HIV cases in Bahia from January 2015 to December 2022. The pre-pandemic period (2015–2019) served as the baseline to forecast expected notification trends, which were then compared to observed case numbers during the pandemic years (2020–2022). The percentage change between observed and expected values was calculated and analyzed at the state, regional, and macro-regional levels. Between 2020 and 2022, a total of 8382 new HIV cases were expected (an average of 2794 annually). A significant reduction was observed in 2020, with a 12.8% decrease (357 fewer cases than expected), followed by a 3.2% decrease in 2021 (89 fewer cases). Notifications partially recovered in 2022, showing a 2.1% increase (50 more cases than expected). The most affected health macro-regions in 2020 were the Central-Eastern macro-region with the largest negative percentage decrease in cases (-38%). The impact was heterogeneously distributed, with the Central-Eastern macro-region experiencing the sharpest decline in 2020 (-38%), the Northern macro-region in 2021 (-21%), and the Far Southern macro-region in 2022 (-29%). The Covid-19 pandemic led to a substantial and heterogeneous reduction in HIV cases across Bahia. Although a partial recovery occurred in 2022, case detection has not yet returned to pre-pandemic projected levels. These findings underscore an urgent need for bold, targeted strategic plans to actively identify and link to care people living with HIV in the affected regions.

We investigate the scattering of spin waves in a two-dimensional square Heisenberg lattice containing an extended ladder-type bond defect. Within a semiclassical large- S approach, we derive analytical expressions for the magnon transmission coefficient and identify the conditions for perfect (resonant) transmission across the defect. We show that the presence of an antisymmetric Dzyaloshinskii–Moriya interaction induces chiral phase shifts that lead to momentum-dependent transparency windows and strong nonreciprocal (diode-like) magnon transport in the ferromagnetic regime. The positions and widths of the resonant channels can be tuned by the defect coupling, exchange anisotropy, and the strength of the Dzyaloshinskii–Moriya interaction. In contrast, antiferromagnetic magnons exhibit a qualitatively different scattering behavior, characterized by mode-selective resonances and fragmented rectification patterns that require finer parameter tuning. These findings demonstrate that ladder-type defects provide a simple and versatile platform for controlling magnon transport in two-dimensional magnetic systems. • We investigate spin-wave scattering in square lattices containing an extended ladder-type bond defect line. • The transmission of ferro and antiferromagnetic magnons is modified by combining anisotropic and antisymmetric interactions along the defect ladder. • Ferromagnetic magnon transport is transparent and strongly non-reciprocal under specific incidence conditions. • Antiferromagnetic magnon transport exhibits qualitatively different scattering behavior, showing selective resonances and a fragmented rectification pattern. • Our results highlight the extended ladder-type defect line as a flexible platform for engineering resonant and momentum-selective magnon transport.