Search Results (77)

Soil degradation and water scarcity pose major challenges to sustainable agriculture in semiarid regions, requiring innovative strategies to enhance water use efficiency (WUE) and soil fertility. This study assessed the effects of sewage sludge biochar (SSB) on soil properties, WUE, and common bean yield through a small-scale controlled field experiment under rainfed conditions in Northeast Brazil. Four SSB application rates (5, 10, 20, and 40 t ha⁻¹) were compared with conventional NPK fertilization, treated sewage sludge (SS), and chicken manure (CM). The application of 20 t ha⁻¹ (B20) significantly improved soil organic carbon, nitrogen content, water retention, and microbial biomass. B20 also increased WUE by 148% and grain yield by 146% relative to NPK, while maintaining safe levels of potentially toxic elements (PTE) in bean grains. Although 40 t ha⁻¹ (B40) enhanced soil fertility further, it posed a risk of PTE accumulation, reinforcing the advantage of B20 as an optimal and safe dose. These results highlight the potential of SSB to replace or complement conventional fertilizers, especially in sandy soils with limited water retention. The study supports SSB application as a sustainable soil management practice that aligns with circular economy principles, offering a viable solution for improving productivity and environmental resilience in semiarid agriculture. Full article

Human T-lymphotropic virus 1 (HTLV-1) infection has been associated with inflammatory, autoimmune, and lymphoproliferative diseases with a wide spectrum of clinical manifestations. Among patients with inflammatory rheumatological disease manifestations, cases of rheumatoid arthritis, Sjögren’s syndrome, polymyositis, and fibromyalgia, among others, have been reported. Another common feature of rheumatological diseases is the presence of joint manifestations, such as arthralgia and arthritis. In the present study, we sought to determine the laboratory profile and clinical rheumatological manifestations of people living with HTLV-1/2 residing in a metropolitan area in the Brazilian Amazon. A total of 957 individuals were screened for HTLV-1/2 infection by enzyme-linked immunosorbent assay (ELISA), and samples from seropositive individuals were subjected to infection confirmation by Western blotting or quantitative polymerase chain reaction (qPCR). Individuals with confirmed HTLV-1 and HTLV-2 infection were clinically evaluated for signs and symptoms of rheumatological diseases. Of the 957 individuals tested, 69 were positive for HTLV-1/2 infection, with 56 confirmed cases of HTLV-1 infection (5.9%), 12 of HTLV-2 infection (1.2%), and 1 classified as undetermined (0.1%). After clinical screening, 15 infected individuals with complaints suggestive of rheumatological disease were selected for evaluation by a rheumatologist (11 with HTLV-1 infection (1.1%) and 4 with HTLV-2 infection (0.4%)). The predominant pain pattern was symmetrical polyarthralgia, with large joints predominantly being affected. The diseases diagnosed were psoriatic arthritis, osteoarthritis, fibromyalgia, and regional pain syndromes. Antinuclear antibody (ANA) positivity was observed in two patients. Our findings confirm that HTLV-1 infection is associated with rheumatological disease manifestations and highlight the novel finding of cases of HTLV-2 infection in patients with rheumatoid arthritis symptoms. Full article

The Brazilian forestry sector comprises 9.94 million hectares of plantations, with eucalyptus dominating 75% of this area for pulp production. Technological advances have enhanced machinery performance, with the cut-to-length system being the primary method for pulpwood production. This study aimed to optimize the operational cycle of the log loader by evaluating productivity, operational cycles, and loading costs. Data were collected in Bahia, northeastern Brazil, from a forestry company operating under varying productivity scenarios and forest rotations. Time and motion studies were conducted to assess the log loader’s cycles, while productivity and cost analyses were performed. The results indicated that predictive models effectively explained productivity variations. The log loader’s productivity increased with the average volume per tree (AVT) and decreased with the number of movements, which consumed 68% of the cycle time due to wood adjustment and stack organization. Stages such as personal breaks, truck movements, crane adjustments, and cleaning of fallen material showed no significant statistical differences. Loading costs rose by up to 154% with increased movements and decreased with a higher AVT. Additionally, loading tri-train trucks significantly influenced transportation efficiency, emphasizing the importance of optimizing the log loader’s cycle to balance costs and enhance transportation operations. Full article

The use of agro-industrial waste, such as wood ash or biomass ash, has been adopted as an alternative to synthetic fertilizers for providing nutrients to plants. This study aimed to evaluate the levels of primary and secondary macronutrients in soil cultivated with chrysanthemum under different types of fertilization management: organic, organomineral, and mineral, with and without liming. The experiment was conducted in a greenhouse for 185 days, using a randomized blocks design in a 5 × 2 factorial scheme: five fertilization types (incubated and unincubated wood ash, organomineral fertilizer, mineral fertilizer, and control) and two levels of liming (without liming and 70% base saturation) with five replicates. The soil used was Oxisol. The phosphorus, potassium, calcium, magnesium, and sulfur contents in the soil after cultivation were analyzed. There was a 77% increase in potassium in treatments with ash compared to treatments without ash. The corrected soil presented 173.2 mg dm⁻³ of potassium, compared to 153.6 mg dm⁻³ in the uncorrected soil, an increase of 11.6%. The calcium levels increased by 60% with the application of ash (incubated or not) and organomineral fertilizer, compared to soils without ash. Liming increased calcium by 1.12 cmol_c dm⁻³. Fertilizers with ash associated with liming resulted in higher magnesium levels. The sulfur content varied according to the fertilizer, with non-incubated ash showing the highest value (69.11 mg dm⁻³) compared to the control (11.08 mg dm⁻³), a difference of 83.96%. Organomineral fertilizer is an alternative for increasing the availability of macronutrients in the soil, allowing a second cropping cycle without the need to manage soil fertility, contributing to sustainable agriculture, encouraging the reuse of waste, and reducing the use of mineral fertilizers. Full article

This study seeks to investigate the heat dissipation process in a minichannel heat exchanger, commonly employed for cooling electronic components. The analysis centers on two key factors: global thermal resistance (G_TR) and the heat transfer coefficient. The innovation of this study resides in the development and analysis of a mini heat exchanger optimized using chemometric methods to achieve efficient thermal dissipation. Various conditions, including the power source, volumetric flow rate, and ambient temperature, were varied at both low and high levels to assess their impact on these variables and establish the optimal conditions for heat dissipation. The cooling of electronic components, such as processors, remains a topic of ongoing research, as the miniaturization of components through nanotechnology requires enhanced heat dissipation within increasingly smaller spaces. This experimental study identifies the optimal conditions for both G_TR and the heat transfer coefficient within the examined parameters. G_TR is minimized with a power of 30 W, an ambient temperature of 29 °C, and a flow rate of 2.50 L·min⁻¹. The results indicate that electrical power was the most significant variable affecting G_TR, while ambient temperature also played a determining role in the heat transfer coefficient. Full article

Introduction: The fruit of the cashew tree, known as cashew, is accompanied by the fleshy extension of its stem, referred to as the cashew nut. Rich in phenolic compounds, such as phenolic acids, anthocyanins, flavonoids, carotenoids, polyphenols, as well as vitamins C and E, the cashew nut exhibits antioxidant properties. Objective: This systematic review investigated the effects of cashew nuts on oxidative stress in rats. Methodology: The study followed PRISMA guidelines and was registered in PROSPERO. Searches were conducted in the Medline (PubMed), EMBASE, BVS, MedRxiv, Science Direct, Scopus, and Web of Science databases. Experimental studies with rats as the target population, evaluating the effects of cashew nut supplementation on oxidative stress, antioxidant enzymatic activities, and inflammatory markers, were included. Exclusion criteria comprised dissertations, reviews, expert opinions, duplicates, and preprints. Results: Five studies published between 2018 and 2022 were included, all utilizing cashew nut supplementation as the intervention. The results demonstrated a significant reduction in oxidative stress, an increase in the activity of antioxidant enzymes, such as SOD and catalase, and a decrease in inflammatory markers, including TNF-α and IL-1β. The most effective dose was 100 mg/kg/day, yielding consistent results across studies. Conclusion: Cashew nuts show potential for reducing oxidative stress, mitigating inflammation, and enhancing antioxidant defenses in rats. However, further clinical studies are required to better explore their benefits in humans, a field that remains less studied compared to other types of nuts. Full article

In this work, tin and zinc salts of silicotungstic and phosphotungstic acids were synthesized, characterized, and tested as catalysts for esterification reactions of glycerol with acetic acid (HOAc) to produce glycerol esters such as monoacetyl glycerol (MAG), which are used as additives in the pharmaceutical and food industries and in the manufacturing of explosives, or, in the case of di- or triacetyl glycerol (DAG and TAG), green bioadditives for diesel or gasoline. The activity of metal-exchanged salts (Zn, Sn) in H₃PW₁₂O₄₀ and H₄SiW₁₂O₄₀ heteropolyacids was evaluated in esterification reactions at room temperature. Among the catalysts tested, Sn_2/3PW₁₂O₄₀ was the most active and selective toward the glycerol esters. The process’s selectivity can be controlled by changes to reaction conditions. The maximum selectivitiesy of DAG and TAG were 60% and 30%, respectively, using a 1:3 molar ratio of glycerol/HOAc and a Sn_3/2PW₁₂O₄₀/673 K catalyst load of 0.4 mol%. Under these conditions, a glycerol conversion rate of 95% was observed and selectivity towards DAG and TAG was observed at 60% and 30%, respectively. The results were achieved after an 8 h reaction at a temperature of 333 K. The Sn_3/2PW₁₂O₄₀/673 K catalyst demonstrated the highest efficiency, which was attributed to its higher degree of acidity. Full article

Background/Objectives: Curcumin has antimicrobial activity, and its mechanism of action involves changing histone acetylation. Our group has shown that histone deacetylases (HDACs) inhibitors increase the sensibility of Cryptococcus neoformans to certain antifungal treatments. Therefore, the aim of this work was to investigate whether curcumin pretreatment increases the effect of photodynamic therapy (PDT) mediated by aluminum phthalocyanine in nanoemulsion (AlPc-NE) against C. neoformans. Methods: The minimum inhibitory concentrations (MIC) of AlPc-NE and curcumin, along with the 72-h growth curve of cells exposed to the combined treatments, were evaluated in the C. neoformans reference strain H99. Additionally, further analysis was performed using HDAC gene deletion mutant strains, hda1Δ and hos2Δ. Results: Curcumin reduces the effect of PDT on C. neoformans reference strain H99, likely due to its antioxidant properties. In the hda1Δ strain, 50% MIC of curcumin reduced the effect of PDT, but this effect was not observed in response to 75% MIC of curcumin. Conversely, in the hos2Δ strain, pretreatment with curcumin at 75% MIC enhanced the efficacy of PDT in combination with 50% MIC of AlPc-NE. Conclusions: These results indicate that curcumin inhibits C. neoformans. Moreover, at lower concentrations, curcumin protects cells against oxidant damage, while at higher concentrations, it may trigger epigenetic mechanisms that compromise cell viability. In conclusion, both curcumin and PDT are active against C. neoformans, with HDACs affecting their efficacy, and the effectiveness of the combined treatment depends on the concentration of both curcumin and AlPc-NE. Full article

This study aimed to evaluate the influence of age on the colorimetric parameters, chemical composition, and biological resistance of teak heartwood, transition zone, and sapwood. Samples of 13- and 22-year-old trees were collected from fast-growing commercial plantations in Mato Grosso, Brazil. From the heartwood, transition zone, and sapwood sections, we determined the CIEL*a*b* system colorimetric parameters and extractive contents and performed Py-CG/MS analysis and an accelerated degradation assay with the xylophagous fungus Trametes versicolor (L.) Lloyd. The 22-year-old wood presented greater redness and lower yellowness, and the heartwood was darker, with greater redness and lower yellowness than the other radial positions. The average content of total extractives varied between ages: 7.83% (13years) and 8.23% (22years). A total of 119 compounds were identified in teak wood, of which 51 presented areas greater than 1%. Quinones were identified in the heartwood and transition zone, with similar values between ages and approximately 7% in the heartwood. Although the durability increased significantly with age, the magnitude was slight. Wood from 22-year-old trees exhibited a lower average mass loss (10.30%) compared to wood from 13-year-old trees (12.68%). In contrast, differences between regions were more pronounced. Sapwood showed a mass loss of 22.5%, transition zone wood of 10.14%, and heartwood of 1.86%. We concluded that age influenced the colorimetric parameters, chemical composition, and biological resistance of teak wood. Teak heartwood from fast-growing plantations, both from final harvesting (22-years-old) and from thinning (13-years-old), is indicated for uses that require high biological resistance. Full article

Background and Objectives: Suicide is a pressing public health issue globally, including in Brazil, where it ranks among the leading causes of mortality. This study aimed to analyze the spatial, temporal, and spatiotemporal distribution of suicide mortality in Brazil from 2000 to 2022. Materials and Methods: Using secondary data from the Mortality Information System of Brazil’s 5570 municipalities, an ecological study of time series was conducted. Segmented linear regression (Joinpoint 4.6 version) was used to calculate temporal trends, while Moran’s indices were employed to analyze spatial autocorrelations. Retrospective scanning was utilized to investigate spatiotemporal clusters, and choropleth maps were developed to visualize high-risk areas. Results: The analysis revealed the occurrence of 240,843 suicides in Brazil, with higher percentages in the southeast, south, and northeast regions. The south, central–west, and southeast regions exhibited the highest mortality rates, predominantly among white, single men, aged 20 to 59, with 1 to 11 years of schooling. Intentional self-harm by hanging, strangulation, and suffocation was the main cause. The general trend of mortality due to suicide in Brazil was increasing (AAPC: 2.9; CI 95%: 2.6 to 3.0), with emphasis on the age groups from 10 to 19 years (AAPC: 3.7; CI 95%: 2.9 to 4.5) and 20–39 years old (AAPC: 2.9; CI 95%: 2.3 to 3.5). The brutal and smoothed rates revealed areas of high mortality in the south, north, and central–west regions. Conclusions: The findings of this study highlight the need to direct resources and efforts to the south and midwest regions of Brazil, where suicide rates are the highest. Additionally, implementing targeted prevention programs for young men, who are the most affected, is essential to reduce suicide mortality in these areas. Full article

Green hydrogen (H₂) offers a sustainable alternative to non-renewable energy sources. This study focuses on enhancing H₂ generation from sodium borohydride (NaBH₄) using a platinum nanoparticle (Pt-NP) catalyst supported on a niobium-based coordination compound, [Nb(BDC)_0.9(PDC)_0.1]_n, synthesized via a solvothermal method with 1,4-benzenedicarboxylic acid (BDC) and 2,5-pyridinedicarboxylic acid (PDC). Characterization techniques including Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Brunauer–Emmett–Teller (BET) analysis, Raman spectroscopy, and X-ray diffraction (XRD) confirm the morphology, composition, surface area (398.583 m²g⁻¹), and crystallinity of the material. The in situ synthesized Pt-NPs showed a hydrogen generation rate (HGR) of 86.588 mL min⁻¹ g⁻¹ when alone, while the supported catalyst achieved an enhanced HGR of 119.020 mL min⁻¹ g⁻¹ under optimal conditions (10 mmol% Pt, 0.5 mmol NaBH₄, 303.15 K). The low activation energy (E_a) of 16.38 kJ mol⁻¹ indicates efficient catalysis. The catalyst maintained stable performance in recycling tests, demonstrating its potential for practical applications in H₂ evolution from NaBH₄. Full article

Anaerobic digestion followed by microalgal cultivation is considered a promising renewable alternative for the production of biomethane with reduced effluent generation, thus lowering the environmental impact. In this arrangement, in addition to generating energy, the microalgae act by potentiating the refinement of the effluents generated via anaerobic digestion (digestates). In this study, the microalga Tetradesmus obliquus was cultivated in photobioreactors with the final digestate resulting from the co-digestion of Arundo donax L. plant biomass and cattle wastewater. The biotechnological route used was efficient, and the biogas production ranged from 50.20 to 94.69 mL gVS⁻¹. The first-order kinetic model with variable dependence (FOMT) provided the best fit for the biogas production data. In the microalgal post-treatment, the removal values ranged from 81.5 to 93.8% for the chemical oxygen demand, 92.0 to 95.3% for NH₄⁺-N, and 41.7 to 83.3% for PO₄³⁻ after 26 days. The macromolecular composition of the algal biomass reached lipid contents ranging from 33.4 to 42.7%. Thus, the proposed process mediated by microalgae can be considered promising for the bioremediation and recovery of effluents produced by agriculture through the use of microalgal biomass for bioproduct production. Full article

Artificial Intelligence (AI) has changed how processes are developed, and decisions are made in the agricultural area replacing manual and repetitive processes with automated and more efficient ones. This study presents the application of deep learning techniques to detect and segment weeds in agricultural crops by applying models with different architectures in the analysis of images captured by an Unmanned Aerial Vehicle (UAV). This study contributes to the computer vision field by comparing the performance of the You Only Look Once (YOLOv8n, YOLOv8s, YOLOv8m, and YOLOv8l), Mask R-CNN (with framework Detectron2), and U-Net models, making public the dataset with aerial images of soybeans and beans. The models were trained using a dataset consisting of 3021 images, randomly divided into test, validation, and training sets, which were annotated, resized, and increased using the Roboflow application interface. Evaluation metrics were used, which included training efficiency (mAP50 and mAP50-90), precision, accuracy, and recall in the model’s evaluation and comparison. The YOLOv8s variant achieved higher performance with an mAP50 of 97%, precision of 99.7%, and recall of 99% when compared to the other models. The data from this manuscript show that deep learning models can generate efficient results for automatic weed detection when trained with a well-labeled and large set. Furthermore, this study demonstrated the great potential of using advanced object segmentation algorithms in detecting weeds in soybean and bean crops. Full article

The industrial processes used to produce paper and cellulose generate many lignocellulosic residues. These residues are usually burned to produce heat to supply the energy demands of other processes, increasing greenhouse gas emissions and resulting in a high environmental impact. Instead of burning these lignocellulosic residues, they can be converted into saccharides, which are feedstock for high-value products and biofuels. Keggin heteropolyacids are efficient catalysts for obtaining saccharides from cellulose and hemicellulose and converting them into bioproducts or biofuel. Furfural, 5-hydroxymethylfurfural, levulinic acid, and alkyl levulinates are important platform molecules obtained from saccharides and raw materials in the biorefinery processes used to produce fine chemicals and biofuels. This review discusses the significant progress achieved in the development of the processes based on heteropolyacid-catalyzed reactions to convert biomass and their residues into furfural, 5-hydroxymethylfurfural, levulinic acid, and alkyl levulinates in homogeneous and heterogeneous reaction conditions. The different modifications that can be performed to a Keggin HPA structure, such as the replacement of the central atom (P or Si) with B or Al, the doping of the heteropolyanion with metal cations, and a proton exchange with metal or organic cations, as well as their impact on the catalytic activity of HPAs, are detailed and discussed herein. Full article

We examined the effectiveness of metal-exchanged phosphomolybdic acid salts in converting levulinic acid, derived from biomass, into valuable products (alkyl levulinate). We prepared salts of phosphomolybdic acid using different metals (Fe³⁺, Al³⁺, Zn²⁺, Cu²⁺, Mn²⁺, Ni²⁺, and Co²⁺). The influence of metal cations on the conversion and selectivity of the reactions was assessed. We found that the salts prepared with iron and aluminum phosphomolybdate were the most effective catalysts for the esterification of levulinic acid with methanol, with the conversion and selectivity tending towards 100% after 6 h of reaction at a temperature of 323 K. The effect of catalyst loading and its recovery and reuse was evaluated; the results from the reaction using aluminum phosphomolybdate remained similar for four cycles of use. The influence of temperature on conversion and selectivity was investigated between 298 and 353 K. The reactivity of different alcohols with a carbon chain size of C1-C4 was assessed and conversions above 65% were obtained for all alcohols tested under the conditions evaluated, except for tert-butyl alcohol. These catalysts are a promising alternative to the traditional soluble and corrosive Brønsted acid catalysts. The superior performance of these catalysts was ascribed to the higher pH decline triggered by the hydrolysis of these metal cations. Full article