Ciência e Natura

Adsorption study of micropollutants by biosorbents from different rice harvest residues for large scale applications

2024-05-22T13:23:33-03:00

A large-scale removal of micropollutants from residual waters is an urgent problem to be tackled. In this work, three biomasses from agricultural residues, produced by different processes, were compared in terms of the adsorption efficiency of toxic species in water. The biosorbents used were rice husk ashes (RHA), leached rice husk silica (SRHA), and rice straw ashes (RSA). Two representatives of the most common micropollutants present in the effluent waters, 2-nitrophenol and the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D), were chosen as probing molecules. The biosorbents were characterized by SEM, X-Ray FRX, FT-IR, BET, pHcpz, and hydrophobicity; surface areas of 175.81 m2 g-1(SRHA), 66.11 m2 g-1 (RHA) and 42.77 m2 g-1 (RSA) were found, together with a microporous morphology. Firstly, the efficiency of removal was evaluated through adsorption isotherms: RHA and SRHA proved to be more efficient, with an adsorption capacity of 29.14 mg g-1 and 23.75 mg g-1 of 2-nitrophenol and 10.82 mg g-1 and 10.55 mg g-1 for 2,4-D. In particular, the removal of more than 90% for both 2-Nitrophenol and 2,4-D stands out as a very promising result. In light of these results, pillow-shaped filters with RHA were fabricated and tested for the first time for 2-Nitrophenol removal on a larger scale. The positive outcome (removal efficiency of 73%) demonstrates the possibility of producing filters based on sustainable and cheap biosorbents that could be implemented industrially to improve water purification as well as to implement the concept of circular economy.

Effect of cryoprotectants on the semen quality of Nile Tilapia Oreochromis niloticus

2024-08-27T07:46:44-03:00

Samples of Nile Tilapia (Oreochromis niloticus) semen were collected with the aim of evaluating the quality of cryopreserved semen using methanol and dimethylacetamide (DMA) as cryoprotectant agents at the concentrations of 7.5% and 10% each. The diluent (base) used in each cryoprotectant consisted of Beltsville Thawing Solution (BTS). An examination of the motility factors, robustness, and duration of motility was conducted using sodium carbonate (at 1% solution) for semen activation. The results were higher in methanol regarding robustness, and 7.5% methanol in relation to motility rate and duration of motility. The cryopreservation process increased the number of morphological pathologies, primarily fractured tail, isolated head and folded tail, except for treatment with DMA 7.5%.

Importance of Macroscopic Environmental Analysis for spring preservation used for human consumption

2024-08-27T07:46:36-03:00

The lack and deterioration of the quality of water resources have made governments take educational measures and required society to rethink habits concerning the preservation and conservation of water quality. Thus, the present study aims to present the importance of spring preservation for water quality conservation as well as to develop a macroscopic environmental analysis of springs located in the state of Rio Grande do Sul, Brazil. Twenty springs were observed in two different periods of the year (May and November 2019), which had different economic activities: native forest – public domain; soybean, tobacco, and pig farming – private domain, in their surroundings. The study adopted five replications (different municipalities), and a macroscopic environmental analysis was carried out in each spring to classify them according to the extent of preservation. It was observed that most of the springs show “Good” and “Very good” preservation. However, it can be concluded that the economic activities developed in the surroundings do not interfere with spring preservation, and the methodology adopted is not recommended for the macroscopic environmental analysis in areas of native forest due to the characteristics considered.

Seasonal climatology of cold fronts in south-central South America from an automated detection system

2024-05-22T13:23:25-03:00

The cold fronts (CF) operating in south and south-central South America are the main ones responsible for heavy rain, thunderstorms with strong winds, and accentuated temperature drops. This study aimed to perform a seasonal climatology of CF’s displacement and intensity in the region above mentioned. A computational algorithm was developed called the Normalized Cold Front Detection Index (NCFI) for detecting and characterizing CFs through the CFSR and CFSv2 reanalysis data, using the meridional component of the wind at 10 meters and the air temperature at 2 meters. Ten areas were delimited: five coastal and five continentals. Seasonal climatology showed a higher frequency in winter, when these systems are more intense, averaging 20 per year. The patterns of displacement and intensity exhibited a decrease in CFs as they advanced toward lower latitudes. The synoptic analysis and the accumulated precipitation composites revealed that the CFs that act in the spring concentrated the accumulated precipitation in Santa Catarina’s western portion. In the summer, convection cells are responsible for storms and poorly distributed rain. In the autumn, rainfall is associated with CFs and maritime circulations, impacting Rio Grande do Sul and the west and north of Santa Catarina. In the winter, CFs dominate the precipitation pattern. According to the NCFI, spring, autumn, and winter cases are categorized as intense, while summer cases are moderate.

Graphene oxide assessment on the germination of Persian clover and buckwheat seeds

2024-05-22T13:23:28-03:00

The increase in the use of graphene oxide (GO) allows different studies in several fields, and raise concerns about its possible toxic effect on the environment, especially in the early growth of plants. Thus, this study aimed to evaluate the effect of GO on the germination of Persian clover and buckwheat seeds. The seeds were placed on germitest paper in different concentrations of graphene oxide (0, 125, 250, and 500 mg L^-1) and kept in a germination chamber at 20 °C (photoperiod of 12 hours). The evaluated parameters were seed germination and seedling growth (length and dry mass). Graphene oxide did not show toxic effects on seed germination and initial growth of both species up to 500 mg L^-1. In this context, understanding the role of graphene oxide in the germination process and the development of plants will be able to contribute positively to understanding its possible environmental impacts when used in large quantities in ecosystems.

Use of pseudomonas fluorecens isolated from the Serra de Ouro Branco State Park/Minas Gerais - Brazil in the biodegradation of residual automotive lubricating oils

2024-09-10T11:50:09-03:00

About 2% of the oil consumed worldwide is related to the production of automotive and industrial lubricating oils. The pollution derived from these oils in aquatic and terrestrial environments is responsible for several ecological and social problems due to their toxic, mutagenic, and carcinogenic properties. Thus, studies related to bioremediation are of importance, and the use of biological treatments, such as biodegradation, is a viable and effective alternative for the treatment of these compounds. The present study aimed to evaluate the biodegradation performance of residual automotive lubricating oils using the lipases Pseudomonas fluorecens obtained in bioprospecting carried out in the Serra do Ouro Branco State Park, Minas Gerais. Through the colorimetric method using the redox indicator 2.6-dichlorophenol-indophenol (DCPIP), the biodegradability of residual oils was monitored. The results obtained demonstrated the potential of the selected bacteria, since they degraded approximately 61.74 to 83.8 % of the waste studied.

LID Implementation in an urban basin: a Brazilian case study

2024-08-27T07:46:48-03:00

Problems related to urban drainage systems and the disorderly growth of large urban centers have led to the search for alternative drainage techniques. These techniques have been called Low Impact Development (LID), and generally influence the reduction of peak flow and runoff volume. In an urban sub-basin in the city of Recife, PE, the hypothesis of replacing existing roofs with a green roof (GR) was considered in three scenarios: (1) pre-urbanized, (2) current, (3.1) 30% of GR, (3.2) 50% of GR, (3.3) 75% of GR, (3.4) 100% of T.V. For this, simulations were carried out in PCSWMM based on the current urbanization situation. Linimetric readings were taken for calibration, obtaining 0.61 NSE and 0.903 R². Validation was carried out using images at two points within the basin. The reduction in peak flow values ranged from 0.74 to 2.10 m³/s, in addition to the time being delayed from 31 to 90 minutes. As for river level values, the variation was between 4 and 13 cm, while volume reductions recorded values between 67.42 and 190.81 m³. Overall, this proposed methodology can help stormwater managers better evaluate the performance of LID techniques at different hydrological scales, showing the importance of prioritizing urban adaptation and green infrastructure implementation.

Environmental variables, floristics, diversity, and species distribution in an Urban Alluvial Forest

2024-08-27T07:46:29-03:00

The Alluvial Forest occurs along the margins of watercourses, as well as in wet lowlands and temporarily flooded zones. This study established correlations between the arboreal vegetation and environmental variables, to discover the main factors that influence the species distribution in fragments of the urban Alluvial Mixed Ombrophilous Forest (Guarapuava, Paraná, Brazil). The floristic survey was conducted in three transects (subdivided into 42 sample subunits of 100 m2), covering the water gradient across the riverbed. The tree species that presented Diameter at breast height (DBH) ≥ 5 cm were measured and identified. The variables measured were: piezometric level, volumetric and gravimetric soil moisture, penetration resistance, and chemical and granulometric soil analysis. The species abundance data were processed using the multivariate technique TWINSPAN, with subsequent phytosociological analysis; the environmental variables were then correlated with the abundance data (ind ha^-1) through the Canonical Correspondence Analysis (CCA). Four groups were formed: (1) well drained soils; (2) moderately drained soils (intermediate characteristics); (3) soils with water saturation and (4) soils with greater hydromorphy. Subunits with higher water influence showed the lowest diversity values and the highest dominance values. The canonical correspondence analysis showed that the distribution of Gymnanthes klotzschiana, Ligustrum lucidum, and Allophylus edulis are related to soil water saturation, while the distribution of Matayba elaeagnoides and Ocotea puberula is correlated with well drained soils. The other species showed a preference for moderately drained soils. The groups separated the species according to environmental characteristics, indicating that hydromorphism influences the establishment of the forest community.

Development and assessment of a selective collection plan for two districts in the Oceanic Region of Niterói, based on the template of the pioneer selective collection of São Francisco - RJ

2024-01-17T15:37:59-03:00

The growing production of urban solid waste is a reality of modern society. A large part of this quantity can be recycled and/or reused in new processes. In some countries, such as Brazil, a very small percentage of total waste is picked up through selective collection projects, and an even smaller portion is recycled. A selective collection initiative established in the district of São Francisco, in the city of Niterói, in the state of Rio de Janeiro, was successful and kept in operation for more than 35 years, being one of the first initiatives of this type registered in the country. Its methodology is different from the general collection, using an alternative model truck where the materials are stored more diligently without the risk of one damaging the other. The present work implemented, monitored, and evaluated a pilot project of selective collection in the districts of Itacoatiara and Camboinhas, also located in Niterói. An average of 900 kilograms of material with recycling potential were taken weekly in the Itacoatiara district, an amount 3 times higher than what was collected before the operation, proving the effectiveness of the new model. In Camboinhas, similar results were obtained, although they needed to be improved in some respects. Thus, it was found that changing the type of vehicle and optimizing the collection were crucial points to improving the efficiency of the carried-out processes.

Aflatoxin M1 in milk and dairy products in Brazil: a review of characteristics, contamination, human exposure and health risks

2024-05-22T13:23:50-03:00

This paper aimed to present a review of the presence of aflatoxin M1 in milk and dairy products in Brazil, along with its characteristics and potential risks to human health. Overall, most studies analyzed during the defined period of this review (2013 to May 2023) reported average concentrations of AFM1 within the limits established by Brazilian legislation for milk, powdered milk, and cheese. However, considering the consumption of milk and dairy products by more vulnerable groups, such as children, two studies reported levels of AFM1 above the limits established for aflatoxins in different regions of Brazil. Thus, a more rigorous inspection by the responsible Brazilian authorities is necessary. Furthermore, since AFM1 is the only mycotoxin present in milk relevant to public health, it is important to continue conducting studies on the detection and determination of aflatoxins in milk and dairy products. This is necessary to monitor these contaminants and estimate the levels to which the population is exposed.

Use of green vegetable barriers as environmental noise attenuators: a case study in Irati, Parana

2024-05-22T13:23:37-03:00

The present study aims to evaluate the potential of the Secondary Mixed Ombrophilous Forest as a vertical noise-attenuating green barrier. The methodology calls for the development of an analysis of proximity between sampling points of omnidirectional noise monitoring to be measured at various distances from the source from the beginning of the barrier and inside the forest. A sound source reproducing amplified pink noise was used. In this research, an experimental strategy was used to prove the influence of this type of green plant barrier as a noise attenuator as one enters the interior of a fragment of Mixed Ombrophilous Forest, carrying out successive measurements of the sound pressure level at distances from the proximity of the source and the distances from the edge towards the interior of the forest that can prove the significant attenuating function of this type of green vertical barrier. In fact, the analyses performed for LZeq A and Z (dB) confirm a significant correlation for distance from the source regardless of the sound amplitude for measurements performed outside the barrier (in front of the source, 6 m behind the source, 6 meters in front of the source), as noise attenuation occurs as the sound propagates. However, the analyses inside the barrier (at 12m, 18m and 24m) present a negative correlation for distance, confirming the hypothesis of the effectiveness of the attenuation by the vegetal barrier.

Fluvial waters toxicology related to its land use and land cover

2024-09-10T11:50:13-03:00

Due to uncontrolled population growth and intensified anthropic activities, numerous environmental impacts occur in water bodies, such as the toxicity of their waters. This study aimed to evaluate the water toxicity of the Antas River through ecotoxicological bioassays using neonates of the microcrustacean Daphnia magna, and to relate it to land use and land cover in areas near the river. Fourteen sampling points were selected along the entire assessed stretch of the river, and water samples were collected and subjected to acute toxicity analyses using neonates. Land use and land cover mapping of the Antas River Watershed was generated, and an analysis was conducted within approximately a 400-meter radius from each sampling point. The occupation rates for each evaluated area were quantified and subsequently correlated with the obtained toxicity data. The results revealed a high significance level (99%) indicating that land use and land cover in the vicinity of water bodies directly influence water toxicity, impacting it in urban areas or preserving it in native forest areas, depending on the land use, as assessed through acute assays using neonates of the microcrustacean Daphnia magna.

Contamination by potentially toxic metals from urban rivers located in an area covered by the Guarani Aquifer in Southern Brazil

2024-09-10T11:50:50-03:00

The present study aimed to evaluate the concentration of heavy metals considered globally alarming, such as cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn), in the surface water and in the sediment of urban rivers located in an area covered by the Guarani Aquifer, in Lages, southern Brazil. The water and sediment samples were collected in September and October 2016 in three urban rivers. The quantification of the metals was performed through an atomic absorption spectrometer. The levels of Cd, Cr, Cu, Pb and Zn in the control points (P1 and P7) presented a concentration below the level I proposed by Brazilian legislation 344/2004 of the National Environment Council (CONAMA), while the other points presented concentrations higher and above level I, evidencing an increase of metals in the rivers from upstream to downstream of the urban area of Lages. Cr concentrations above level II proposed by Brazilian legislation at the mouth of the Carahá River were also found, and this value may have adverse effects on aquatic biota. The results show that urban rivers in the area covered by the Guarani Aquifer in Lages have been contaminated by toxic elements associated with anthropogenic activities.

The use of magnetic nanocomposites containing carbon derivatives and biopolymer for aquatic contaminants removal

2024-07-16T09:31:55-03:00

Anthropogenic activities and industrial development are consequences of the increase in the world population occurred in the last century. The result is more generation of waste through textile and metal-mechanic industries mainly by carrying out improper disposal, without proper treatment directly in the environment. This practice is criminal and causes irreversible damages to humans and other animals affected by the contaminants. As a result, the exploration, research, and development of new materials with “green” characteristics as well as new compounds, which is the case of magnetic nanocomposites containing graphene oxide and chitosan in their structure. The present review approaches these materials and their application in process for adsorption of metallic contaminants and dyes. The combination of these nanomaterials presents a potential and promising characteristic in the adsorption processes, demonstrating high efficiency, easy handling, and reusable capacity due their magnetic characteristic and combined properties.

Comparison between evapotranspiration estimate methods in the state of Rio Grande do Sul

2024-08-27T07:46:21-03:00

The characterization of evapotranspiration requires time and financial investment, but from meteorological data, it is possible to estimate the values of this phenomenon by means of indirect methods. The Penman-Monteith FAO (PM) method is considered the most accurate by the Food and Agriculture Organization of the United Nations (FAO), which recommends its use because it takes into account solar radiation, temperature, relative humidity, and wind speed, data that are not always available in some locations in Brazil, making it necessary to use more simplified methods. Therefore, the objective of this work is to compare the evapotranspiration estimated by the Penman-Monteith FAO method with the evapotranspiration estimated by the methods of Penman-Monteith Simplified (PMS), Priestley-Taylor (PT), and Hargraves-Samani (HS) for the 10 weather stations of the National Institute of Meteorology (INMET) distributed in the Pampa biome in the state of Rio Grande do Sul. The results obtained indicated some divergences between the compared methods. However, the PT method showed more accurate results, with the best performance among the proposed methods. This indicates that this method can be used in future studies in the region, especially in cases of a lack of meteorological data.

Spatial distribution of soil loss tolerance limits for the state of Paraíba using GIS

2024-05-22T13:23:12-03:00

Changes in the physical and chemical attributes and biological processes of the soil over a long period of time lead to loss of ecosystem function and agricultural productivity. This work aimed to estimate, classify and map the soil loss tolerance limits for the lands of the State of Paraíba based on the values of the different soil classes, with variation in thickness of horizons and textural relationship, using modeling of geoprocessing data and techniques. The estimate was based on the effective depth, texture and density of the soils described in the 64 profiles from the Exploratory and Soil Recognition Survey and the Agricultural Zoning of the State of Paraíba and calculated using the Smith and Stamey (1964) method and using QGIS© for mapping. Soil loss tolerance followed the order of Oxisols > Cambisols > Argisols > Luvisols > Planosols > Neosols > Vertisols due to the influence of parameters such as effective soil depth and textural relationship between B and A horizons. Soil loss tolerance presented in the very high class an average of 20.08 t ha-1 yr-1 and are associated with Oxisols, Argisols, Cambisols, Planosols and Gleissoils. The upper class presented average losses of 10.56 t ha-1 yr-1 under Argisols. The tolerance limit for losses in the middle class was 6.59 t ha-1 yr-1 distributed under the Luvisols. The low class occurred in Luvisols, Planosols and Neosols distributed in 389 mapping units with an average limit of 3.90 t ha-1 yr-1; in the very low class it occurred under the Vertisols, Nátric Planosols and shallow Neosols with an average of 1.64 t ha-1 yr-1 of soil loss tolerance distributed in 362 mapping units.

Accuracy analysis of mapping land use and occupation using Sentinel-2 and CBERS-4 images in the surroundings of a reservoirs

2024-08-27T07:46:15-03:00

Detecting changes in land cover helps policymakers understand the dynamics of environmental changes to ensure sustainable development in the Caatinga biome. Thus, the identification of spatial characteristics by Remote Sensing has emerged as an important aspect of research, and, therefore, adequate and efficient methodology for mapping the necessary land cover is a preponderant factor. In this study, data from the Sentinel-2 and CBERS-4 satellites captured by the MultiSpectral Instrument (MSI) and Panchromatic and Multispectral Camera (PAN) sensors, respectively, were used for classification and accuracy analysis for five land cover classes around dams located in the municipality of Belo Jardim, Pernambuco. The KNN algorithm (K-th nearest neighbor) with a value of k=1 was used for image training and classification. Recent high-resolution images from the European program WorldCover were used as a spatial and thematic reference image. After the Contingency Matrix analysis between the land cover maps and the reference data, an overall accuracy of 57.4% was obtained for the MSI and 54.5% for the PAN product. The results obtained showed that the MSI presented more satisfactory land cover maps than the PAN data. On the other hand, for the shrubby vegetation class, the PAN product presented an r of 0.5, while the MSI had an r of 0.47. Spatial and spectral characteristics of the images were the main causes of the variability found in the thematic accuracy coefficients.

Chemical characterization and biotechnological potential of Salvia rosmarinus Spenn essential oil nanoemulsions

2024-08-27T07:47:01-03:00

This study aimed to determine the total phenolic compounds, evaluate the antioxidant and anti-inflammatory activities of nanoemulsions (O/W) and essential oils (EOs) from Salvia rosmarinus (rosemary). The plant material was obtained in the city of São Luís (MA). The EO was obtained by the hydrodistillation technique in a modified Clevenger extractor and the NOE's by phase inversion. The chemical constituents of EO were determined by GC-MS. The determination of total phenolic compounds (TPC) was performed by the Folin-Ciocalteu method. The anti-inflammatory activity was performed by the method of protein denaturation and the antioxidant activity by the spectrophotometric method of scavenging hydroxyl radicals. The GC-MS allowed quantifying 1,8-cineol (30.22%), α-pinene (22.14%), camphor (18.33%) and camphene (10.36%) as major components of the EO. The TPC of the EO was quantified at 26.74 mg EAT g^-1 and the refractive index at 1.466 nD 25°. In the antioxidant activity test, an EC₅₀ of 80.33 mgL^-1 was obtained for the EO and from 19.56 to 408.85 mg L^-1 for the nanoemulsions. In the anti-inflammatory activity assay, an EC₅₀of 62.46 mgL^-1 was obtained for EO and 64.96 to 4220.25 mg L^-1 for NOE's. Finally, the pharmacological activities tested showed efficient values for EC_50, therefore considered active. This activity is attributed to its chemical compounds present, thus encouraging studies with this species aiming at its potential application in a formulated bioproduct.

Chemical constituents and larvicidal activity of the microencapsulated essential oil of Citrus aurantium L. against Aedes aegypti

2024-09-10T11:50:32-03:00

This study aimed to evaluate the chemical profile and larvicidal activity of the microencapsulated essential oil (EO) of Citrus aurantium L. against Aedes aegypti. The barks of C. aurantium were collected in São Luís-MA. The EO was extracted by hydrodistillation at 100°C for 3h, with chemical characterization through Gas Chromatography coupled with mass spectrometry (GC-MS). Encapsulation of the EO was performed by ionic gelling. To quantify the total phenolic content of the EO, the Folin-Ciocalteu spectrophotometric method was applied. Then, the lethality of the EO against Aedes aegypti was evaluated, and the LC50 for the action of the EO was calculated using the Probit method. The major constituents found in the EO of C. aurantium were: (-)-Terpinen-4-ol (32, 56%) and Caryophyllene oxide (23.52%). The larvicidal activity of the EO showed a LC50 of 3.589 mg L-1. The results indicate that the evaluated EO is composed of substances that provide a good larvicidal effect, revealing its efficiency in combating and controlling Aedes aegypti.

Nanoemulsions of plant-based bioactive compounds with antimicrobial applications: a review

2024-05-22T13:23:41-03:00

The search for alternative antimicrobial agents is attracting increasing scientific interest. Natural products of plant origin are sources of several substances with proven biological activities, including antimicrobial activity. The encapsulation of these products in the form of a nanoemulsion seeks to overcome problems inherent to these products, such as instability and degradation. Based on these considerations, we carried out a bibliographical survey of nanoemulsions produced from plant-derived substances, such as essential oils and extracts, with antimicrobial potential, focusing on antibacterial, antifungal and antiviral activities. Articles and documents published in scientifically relevant journals, as well as keywords classified from Health Sciences Descriptors, were used. All documents relevant to this search reported that nanoemulsions loaded with essential oils and plant extracts from different botanical species had in vitro antimicrobial activity against different microorganisms of medical importance, in addition to enhancing the antimicrobial effects of these bioproducts. Therefore, nanostructured antimicrobials with essential oils and plant extracts can be considered treatment options for microbial diseases: due to their physicochemical properties, they act as better delivery vehicles for natural products with good bioavailability, by reducing toxicity and prolonging the useful life of these natural antimicrobials, thus enhancing treatment for infectious human diseases.

Drying study and phytochemical profile of the aqueous extract of the scaly leaf bulb of Allium cepa L (var.roxa)

2024-05-22T13:23:54-03:00

The objective of this study was to evaluate the phytochemical profile, predict drying kinetics, and quantify the content of total phenolics and flavonoids present in the aqueous extract of the bulb of scamiform leaves of Allium cepa L. The plant material was collected in the municipality of São Luís (MA). For the preparation of the aqueous extract, the cold maceration process was used using distilled water as a solvent. For the study of the drying kinetics, 10 g of the material in natura was submitted to a convective air oven at 45 °C/4h. The statistical parameters were determined by nonlinear regression using the Statistica 10.0software, using the Quasi-Newton method. To determine the total phenolic content, the Folin-Ciocalteu methodology was used. And for the total flavonoids, the aluminum complexation assay was used. The determination of phenolics and total flavonoids revealed significant quantities in the extract, with values of 106.54 mg EAT g-1 and 26.36 mg EAT g-1, respectively. According to the prediction of the statistical data, it was verified that the mathematical methods of Midilli-Kucuk and Verma proved to be adequate to describe the drying process of Allium cepa L. Through the results obtained, the mathematical model was determined for the drying kinetics of the squamous leaf bulb Allium cepa L, in addition to attesting the presence of secondary metabolites, thus making the product fit for biologically active activities.

Chemical profile and therapeutic potential of the essential oil and nanoemulsions of Citrus x sp (Tanja Lemon)

2024-08-27T07:46:58-03:00

The objective of this study was to evaluate the chemical profile and therapeutic potential of the essential oil and nanoemulsions of Citrus x sp (Tanja Lemon). Hydrodistillation was used to extract the essential oil. Gas Chromatography coupled to Mass Spectrometry (GC/MS) was used for the analysis of chemical constituents. The phenolic content (CFT) was analyzed by the Folin-Ciocalteau assay, and flavonoids (CFLT) by complexation with aluminum. The nanoemulsions were formulated by the phase inversion method. The antioxidant activity was evaluated by a hydroxyl radical assay and the anti-inflammatory activity by protein denaturation, and antiarthritic activity by a cyclooxygenase inhibition assay in bovine albumin serum. By means of GC/MS, limonene was identified as the major component (70.25%). The determination of CFT and CFLT quantified 227.645 mg EAT g^-1 and 86.57 mg EQ g^-1. For antioxidant capacity, nanoemulsions have EC₅₀ values of 9.10-11.28 mg L^-1. In anti-inflammatory activity, synergies quantified 4.63-11.03 mg L^-1. For the antiarthritic activity, it is noted that among the nine synergies formulated, some manifested excellent antiarthritic activity, with EC₅₀ values of 1.9-1.98 mg L^-1. It can be affirmed that the formulations produced from Citrus x sp presented satisfactory results, evidencing the efficacy of their properties.

Genotoxic and antiproliferative effect of Alpinia zerumbet (Zingiberaceae) essential oil in Allium cepa biotest

2024-08-27T07:46:34-03:00

The species Alpinia zerumbet popularly known as colony is quite abundant in northeastern Brazil and is widely used for medicinal purposes, due to its hypotensive and cardiovascular effect, without, however, due scientific evidence. Therefore, the objective of this study was to evaluate the genotoxic and antiproliferative effect of A. zerumbet essential oil, in test systems with Allium cepa. The chemical composition of the essential oil was determined by gas chromatography coupled with mass spectrometry (GC-MS). The antiproliferative and genotoxic effect was tested in seven treatments with three replications, and five concentrations of essential oil (0.01 to 1.0%) using onion bulbs. Two roots were analyzed from each bulb, with a count of 500 cells per slide/root, totaling 3,000 cells per treatment. The results showed that the main chemical constituents of the essential oil were 1.8 cineole (60.50%) and terpinen-4-ol (23.80%). In the assays with A. cepa, both the mitotic index (MI) and the cellular alteration percentages differed significantly in relation to the control, through the appearance of chromosomal and nuclear aberrations at the concentrations tested, revealing possible harmful effects to human health.

Chemical characterization and biological potentials of the essential oil from the peel of the fruit of Citrus x sp

2024-09-10T11:50:42-03:00

Considering the importance of essential oils, the study aimed to chemically characterize the peel essential oil of Citrus x sp, determine the phenolic compounds, verify the toxicity against Artemia salina, and test the anti-inflammatory, larvicides, and activities with molluscicides. The peel essential oil of Citrus x sp was extracted by the hydrodistillation technique. GC/MS shows that the major component of the essential oil is limonene (70.25%), observing similarity between the peel essential oil of the same species and between species of the same genus. The total phenolic was 19,25 EAT g^-1. The essential oil showed anti-inflammatory, larvicide, and molluscicide potential, with EC₅₀= 400.05 mg L^-1, LC₅₀ = 20.26 μg mL^-1 and LC₉₀ = 87,50 μg mL^-1, respectively. It did not show toxicity against Artemia salina. The results indicate that the chemical compounds of the peel essential oil of Citrus x sp, which are mostly monoterpenes, prove their wide biological activity, and their use is encouraged.

Polyphenols of four medicinal plants extracts and relation with antifungal activities through in vitro and in silico studies

2024-08-27T07:46:25-03:00

Several medicinal plant´s extracts contain phenolic compounds with antifungal properties useful in pharmaceutical formulations. This study selected species from Cocó River State Park in Fortaleza, Ceará, Brazil, and compare their efficiency as antifungal products. To achieve this goal phenolic profile and anticandidal actions of extracts were evaluated, main constituents were characterized and correlated with antifungal properties through in vitro and in silico studies. Anacardium occidentale, Myracrodruon urundeuva, Laguncularia racemosa, and Terminalia catappa were chosen. The plant parts were collected in accordance with folk medicine recommendation. The main compounds present in the extracts were gallic acid, epicatechin, ellagic acid, isoquercitrin, quercetin and rutin, detected by high performance liquid chromatography analysis. The anticandidal activity of extracts varied from high to moderate, and A. occidentale present the best activity followed by L. racemosa. The in silico studies revealed that affinity energy (∆G) for ellagic acid (-9.4), isoquercitrin (-9.3) and rutin (-9.0) kcal moL^-1 were better in relation to secreted aspartic proteinase 5 (Sap5) from Candida albicans, nevertheless ellagic acid and isoquercitrin act in different places in relation to the active site of Sap5 and could act in synergism with fluconazole.

Potentiation of the anti-inflammatory effect of Attalea speciosa (babassu) oil microemulsions through the incorporation of Citrus x aurantium L. (sour-orange) essential oil.

2024-08-27T07:47:07-03:00

This study analyzed the anti-inflammatory activity of a microemulsion of A. speciosa oil with incorporation of the essential oil of Citrus × aurantium (sour orange). The plant material used in this research was collected in the region of São Luís-MA. The essential oil was extracted by hydrodistillation. The chemical constituents were identified by Gas Chromatography coupled with Mass Spectrometry (GC/MS). The microemulsions were formulated with A. speciosa oil, Citrus × aurantium and Tween 20. The total phenolic content was determined by the Folin-Ciocalteu spectrophotometric method. The anti-inflammatory activity was evaluated using the protein denaturation method with calculation of the 50% Efficient Concentration (EC₅₀). The total phenolic content and refractive index were found, respectively, for the oil of A. speciosa and for the essential oil of C. aurantium, being 238.01; 1.454 and 232.2; 1,470. It was observed that the oil of A. speciosa has greater anti-inflammatory activity than the essential oil of C. aurantium, while the formulated microemulsion showed greater anti-inflammatory activity than both tested individual oils. Finally, it is concluded that the microemulsion was effective in the anti-inflammatory process, indicating that the incorporation of the essential oil of C. aurantium to the microemulsion of A. speciosa increased its anti-inflammatory potential, confirming the possibility of its use with anti-inflammatory action.

Chemical profile and biotechnological potential larvicidal of a nanoemulsion (o/w) of the essential oil of Salvia officinalis L

2024-09-10T11:50:34-03:00

This study aims to evaluate the chemical profile and biotechnological larvicidal potential of the nanoemulsion of the essential oil of Salvia officinalis L. The leaves of the plant were collected in São Luís, MA, from January to May 2021. The essential oil was extracted by hydrodistillation at 100°C for 3h. Chemical characterization was obtained by GC-MS. The oil-in-water nanoemulsion was formulated by the low-energy phase inversion method and subjected to thermodynamic stability tests. Antioxidant activity is performed by the spectrophotometric method of scavenging hydroxyl radicals from salicylic acid. For larvicidal activity, Aedes aegypti larvae were subjected to EO solutions and nanoemulsions in concentrations (10-100 mg L^-1), larval mortality was evaluated, and the LC₅₀was determined by the Probit method. The majority compounds of the EO were: eucalyptol with 65.14%, camphor (30.63%), and α-Terpineol (1.53%). The formulations were characterized as nanoemulsions with a droplet size <200 nm. The PDI was <0.200, indicating a narrow size distribution. The antioxidant activity exhibited EC₅₀ of 136.29 mg L^-1 and 51.59 mg L^-1. The nanoemulsion with larvicidal potential showed an LC₅₀ of 71.17 mg L^-1. The nanoemulsion showed bioactive potential for larvicidal action, which may be related to the presence of its chemical compounds, and its use is encouraged in the fight against Aedes aegypti.

Polyurethanes Thermal, Hydrolytic and Soil Degradation: Systematic Literature Review

2024-06-05T10:41:24-03:00

A search in the Scopus and Web of Science databases covering the period from 2016 to 2021 was carried out and used to update the methodology of polyurethanes hydrolytic, thermal and soil degradation assessment. To that effect, three groups of search words were used: (1) polymer degradation AND “hydrolytic degradation” AND polyurethane; (2) polymer degradation AND “thermal degradation” AND polyurethane; and (3) polymer degradation AND “soil degradation” AND polyurethane. It was observed that the studies on the degradation of polymers are disseminated in different research groups and on a continuous basis during the survey period. The main methodologies found to perform the degradation of polymers were: method of immersion of samples in aqueous solution to evaluate hydrolytic degradation, thermogravimetric analysis, differential exploratory calorimetry and accelerated weathering to evaluate thermal degradation and inoculation of the polymer in soils with different characteristics, such as pH, moisture and organic load to assess soil degradation. Polymers can become a biodegradable solution to the environmental issues generated by plastic waste.

Eco-friendly strategies for the graphene oxide reduction

2024-06-05T10:41:28-03:00

The reduced graphene oxide (rGO) is a nanomaterial derived from graphene, which exhibits a high surface area, chemical stability, and extensive diffusion of π-conjugated bonds. Graphene oxide (GO) can be reduced to rGO through different protocols, however, commonly applied methodologies involving the use of chemical reagents may have disadvantageous effects on the environment. Considering the excellent properties of rGO, this study aimed to reduce GO through sustainable green strategies using carrots, oranges, and beets as reducing agents. The characterization of GO and rGO was carried out by X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electronic microscopy (SEM), which revealed a reduction in the spacing between the layers of GO, indicating the formation of rGO. Due to the outstanding results obtained, future studies will explore the properties of this nanomaterial as an adsorbent for contaminants of emerging concern.

Chemical characterization and biotechnological potential of Salvia rosmarinus Spenn essential oil nanoemulsions

2024-09-10T11:50:37-03:00

This study aimed to determine the total phenolic compounds, evaluate the antioxidant and antiinflammatory activities of nanoemulsions (O/W) and essential oils (EOs) from Salvia rosmarinus (rosemary). The plant material was obtained in the city of São Luís (MA). The EO was obtained by the hydrodistillation technique in a modified Clevenger extractor, and the NOE’s by phase inversion. The chemical constituents of EO were determined by GC-MS. The determination of total phenolic compounds (TPC) was performed by the Folin-Ciocalteu method. The anti-inflammatory activity was performed by the method of protein denaturation, and the antioxidant activity was performed by the spectrophotometric method of scavenging hydroxyl radicals. The GC-MS allowed quantifying 1,8-cineol (30.22%), α-pinene (22.14%), camphor (18.33%), and camphene (10.36%) as major components of the EO. The TPC of the EO was quantified at 26.74 mg EAT g-1 and the refractive index at 1.466 nD 25°. In the antioxidant activity test, an EC50 of 80.33 mgL-1 was obtained for the EO and from 19.56 to 408.85 mg L-1 for the nanoemulsions. In the anti-inflammatory activity assay, an EC50 of 62.46 mgL-1 was obtained for EO and 64.96 to 4220.25 mg L-1 for NOE’s. Finally, the pharmacological activities tested showed efficient values for EC50, therefore being considered active. This activity is attributed to the chemical compounds present, thus encouraging studies with this species aiming at its potential application in a formulated bioproduct.

Impact of climate change on grape composition: a review

2024-09-10T11:50:16-03:00

The objective of this study was to prepare a literature review on the main implications of climate change for the composition of grapes and wine. A literature review was carried out with articles, books, and other scientific materials available in internet databases for indexing terms. A systematic literature review was adopted to prepare this review. Initially, the question for the development of the research was formulated. Soon after the search strategy was defined, the search for manuscripts related to the subject in the databases began. The manuscripts were selected for their relevance and relationship with the key subject of this review. Results inferred that the problems caused by the greenhouse effect, not only globally but also at regional and local levels, are worrying for the agricultural sector. In Brazil, projections for the end of the century indicate an increase of approximately 2°C in temperature, and the vine is a crop highly influenced by the climate, considered a factor of utmost importance for its development, productivity, and quality in the vineyard. Studies have shown that climate change causes changes in temperature, solar radiation, water, and CO2, consequently compromising the composition of sugars, organic acids, phenolic compounds and aromatic compounds, in grapes and wine. It is concluded that the problems caused by climate change in both the composition of grapes and wine are worrying, as they can cause great losses for producers and vineyards. However, more studies and research are needed to propose strategies that can minimize the effects of climate implications.

In vitro germination and seedling formation of Plantago tomentosa Lam. (Plantaginaceae): influence of concentrations of the MS medium

2024-08-27T07:46:40-03:00

Plantago tomentosa Lam. (Plantaginaceae) is an herbaceous plant native to Brazil. It is widely used in folk medicine. The species has potential for use in the pharmaceutical and food industry due to its possible bioactive properties and the presence of mucilage in the seeds. The objective of this work was to investigate the influence of different concentrations of Murashige-Skoog (MS) medium on germination and seedling formation in vitro of P. tomentosa. The seeds were collected in Lajeado, disinfected, and inoculated in bottles with MS medium added to 7 g L^-1 of agar and 30 g L^-1 of sucrose, in four treatments: 25%, 50%, 75%, and 100% of the medium concentration. The experimental design was completely randomized, consisting of 17 replications of ten seeds for each treatment. The evaluation of germination and formed seeds was carried out every two days to determine the variables of germination percentage (GP), mean germination time (MGT), germination speed index (GSI), seedling formation percentage (SFP), mean seedling formation time (MSFT) and seedling formation speed index (SFSI). No significant difference was found between treatments for all the assessed variables. It is concluded that the use of a concentration of 25% of the MS medium is viable, as it promoted a high percentage of germination and seedling formation and in a time interval similar to that of the other concentrations, with the advantage of using fewer reagents.

Urban conservation and tree diversity: a case study in Parque Xokleng, Nova Veneza, Southern Santa Catarina

2024-09-10T11:49:40-03:00

Urban forests can be defined as sets comprising vegetation fragments and isolated or grouped trees inserted in urban or peri-urban areas. Within this mosaic, urban fragments are important for biodiversity conservation. The aim of this study is to contribute to the knowledge about the structure of vegetation in an urban forest in the town of Nova Veneza, Santa Catarina, Brazil. The study was conducted in the Parque Natural Municipal Xokleng (PNMX). A phytosociological survey was conducted in the forest, using the plot method, in which 30 continuous plots of 10 m x 10 m were established. We considered a tree every individual that had a diameter at breast height greater than or equal to 5 cm. In this study, 497 individuals belonging to 75 species and 32 families were sampled, along with 14 dead individuals, three individuals identified only at genus level, and one unidentified individual. The species with the highest importance values were Tetrorchidium rubrivenium, Machaerium stipitatum, Ficus adhatodifolia, Cabralea canjerana, Mollinedia triflora. The vegetation structure is similar to the structure observed in other secondary forest fragments in the southern region of Santa Catarina. The presence of secondary species in the canopy and with high dominance values reflects the regeneration process the forest is undergoing.

Apomictic seed formation and viability in Ilex paraguariensis A.St.-Hil. (Aquifoliaceae)

2024-09-10T11:50:05-03:00

The objective of this study was to investigate fruit and seed formation in Ilex paraguariensis A.St.-Hil. without sexual reproduction in addition to evaluating their viability. This study was based on the hypothesis that the formation of apomictic fruit and seeds occurs, but the seeds are non-viable, contributing to the low germination percentage of the species. Five branches of 20 pistillate mother plants were bagged before anthesis (T1) and five immediately after fruit formation (TC). Once they reach maturity, the fruit were collected and counted. Their seeds were cut lengthwise and classified as intact (with embryo and endosperm) or non-intact (empty and/or deteriorated). The viability of intact seeds was evaluated with the tetrazolium test when they were classified as viable or non-viable. The data were submitted to the Kruskal-Wallis Test. The formation of viable fruit and seeds occurred in smaller numbers in T1, all statistically different from TC (p<0.05). Although in smaller quantities and with a statistical difference, the formation of viable fruit and seeds occurs without sexual reproduction, suggesting that the process responsible for their formation is the facultative apomixis. The higher percentage of viable fruit and seeds in TC is probably a result of the occurrence of both apomixis and sexual reproduction. The percentage of non-viable seeds does not differ between the two treatments, suggesting that apomixis may not be the cause of the low percentage of viable seeds and germination, requiring further studies to understand its causes.

Tree architecture and leaf morphometry of Qualea grandiflora Mart. (Vochysiaceae) in a fragment of dry forest and pasture in the State of Goiás, Brazil

2024-09-10T11:50:21-03:00

Investigating the functional traits of plant communities is extremely important for conserving habitats and plant species. This study aimed to evaluate the tree architecture and leaf morphometry of Qualea grandiflora (Vochysiaceae) in a fragment of semideciduous dry forest and pasture in the Boa Esperança settlement, municipality of Piracanjuba, State of Goiás, Brazil. Environmental, tree architecture, and foliar morphometry data were collected for seven trees in the semideciduous dry forest and five in the pasture area. We used the Shapiro-Wilk test to assess the normality of the collected data. The student t-test was used to compare the means of the functional traits between the two environments (forest and pasture). The average value of canopy cover was 85% for the semideciduous dry forest and 0% for the pasture. The mean values for leaf length and width were lower in the pasture. There was no significant difference in the petiole length in the two evaluated environments and for none of the functional traits related to the tree architecture. However, individuals of Qualea grandiflora grow better in the seasonal semideciduous dry forest, probably as a response to less stressful environmental conditions for this species. Thus, for sustainable exploitation by the local community, it is recommended that the tree matrices be chosen within the semideciduous dry forest area.

Mazaceae in the state of Rio Grande do Sul (Brazil): new records of Mazus pumilus (Burm.f) Steenis

2024-09-10T11:50:26-03:00

Mazaceae in the state of Rio Grande do Sul (Brazil): new records of Mazus pumilus (Burm.f) Steenis. This work contributes to the knowledge about the naturalized species existing in Brazil, with a historical review of the records of Mazus pumilus in the national territory and with the report of the news records of the Mazaceae family for the Pampa biome and the state of Rio Grande do Sul, Southern Brazil, with the occurrence of M. pumilus in the municipalities of Santa Maria and Pelotas. The material was photographed in situ, collected, and registered in herbaria SMDB and ECT.

APPLICATION OF THE BOOTSTRAP METHOD IN THE OPTIMIZATION OF BEET BETACYANIN EXTRACTION

2024-09-10T11:51:00-03:00

The bootstrap method with resampling is a statistical tool that allows obtaining a greater confidence interval without the need for repetitions, as is the case with the RSM. The objective of this work was to apply this method in the extraction optimization of betacyanin from beet. Time and temperature were used in a second-order CCRD, and the response variable was the betacyanin content. The optimum extraction point was obtained by RSM, at 28min and 66°C. From the bootstrap analysis a reliable ellipse was constructed, and the maximum amounts were located at 20-35min and 60-65ºC, confirming the maximum extraction point. These results suggest that the bootstrap method is useful in evaluating the reliability of the optimization of betacyanin extraction from beet, predicted by RSM.

Penny Circle: a study of the Quadratic Function

2024-05-22T13:23:23-03:00

This work aims to present and discuss a pedagogical proposal involving the teaching of Quadratic Function, aimed at high school students. This is research with a qualitative approach, and is supported by the assumptions of mathematical research (Ponte et al., 2019). The activity arose from a reflection on the following question: how could the student recognize the graph of a Quadratic Function in a problem situation, using concrete material? Based on this proposal, the teacher can reflect on the teaching of functions and encourage the student to establish relationships between objects and mathematical problems that, through concrete material, allow experimentation and verification of conjectured results. In addition, review the contents of Affine Function, System Resolution, Radicals, Exponential Function, discuss the concepts of domain, codomain, range and properties of the graph of functions.

Mycology content before and after the BNCC changes: analysis of high school textbooks in public schools in Ariquemes-RO

2024-09-10T11:50:29-03:00

The textbook is considered an essential tool during the teaching-learning process, which is why, for it, the contents must be developed in a clear way and with a scientific basis, in order to facilitate the assimilation of the subjects. The present study aimed to analyze the mycology content before and after the changes in the National Common Curricular Base (BNCC) in high school biology textbooks used in public schools in the city of Ariquemes, Rondônia. For this purpose, a form was prepared containing four axes (content, illustrations, contextualization and extras) and evaluation criteria, points are assigned through a semantic differential rating scale, by means of qualitative and quantitative analysis and later, for the presentation of the results, it was decided to carry out the graphic demonstration of the results obtained in a radar chart. The analysis showed that the books used by schools before the BNCC changes achieved better results in all analyzed axes, while the book used by schools in the state network expressed the lowest degree of satisfaction for all axes and criteria, showing a deficit in the content covered. Finally, there is the need for books to bring the content of mycology arranged in a broad and integral way.

Stress factors and cytotoxic and genotoxic action of ethanol in Saccharomyces cerevisiae

2024-09-10T11:50:57-03:00

In industrial fermentation, Saccharomyces cerevisiae are exposed to different stress conditions. In this sense, the aim of this study was to evaluate the toxic action of ethanolic stress on Saccharomyces cerevisiae. Exploratory research was carried out on the stress factors that cause injuries in yeast. Fermentation tests were conducted with the Fleischmann® and Pedra-2 strains, cultivated in sugarcane juice at 22 ºBrix and pH 5.0, adding concentrations of 5, 10, and 15% of ethyl alcohol, and incubated at 30°C at 250 rpm for 10 hours. For the cytotoxic tests, 100 µl of samples were collected for evaluation of cell growth by spectrophotometric measurements at 570 nm, and 5 µl were dripped into Petri dishes containing 2% YPD solid medium and incubated at 30ºC for 72 hours for colony growth. For the genotoxicity test, the comet test was used with 0.5 µl of the samples added to slides previously prepared and subjected to electrophoretic running and subsequently stained in a 0.1% silver nitrate solution. 100 random nucleotides were evaluated, evaluating five DNA damage classes (0, 1, 2, 3, and 4) according to the intensity and pattern of genetic material entrainment. The results show that stress factors interfere with yeast performance. Fleischmann® showed sensitivity to ethanolic stress.

Cytotoxicity and genotoxicity of aqueous and hydroalcoholic extracts from Gallesia Integrifolia (Spreng) Harms

2024-08-27T07:46:52-03:00

Gallesia integrifolia (Spreng) Harms is a medicinal plant commonly known in Brazil as pau-d'alho. This large tree species belongs to family Phytolaccaceae, which is widely distributed in several Brazilian states. Studies carried out with extracts deriving from different parts of this plant have evidenced its acaricidal, larvicidal, antifungal and bactericidal properties, among others. Thus, given its potential to be used as therapeutic alternative, the aim of the current study was to assess the cytogenetic and mutagenic effect of G. integrifolia, based on using the Allium cepa system and Random Amplified Polymorphic DNA (RAPD) as analysis tools, as well as on germination assay conducted with Lactuca sativa L. Results have indicated that aqueous and hydroalcoholic extracts from G. integrifolia leaves presented cytotoxic, genotoxic and mutagenic effects at the tested concentrations. The herein observed effects may be associated with phytochemical agents found in the tested extracts, as well as emphasize the importance of raising awareness about the indiscriminate use of medicinal plants. Thus, future research should be conducted to help isolating and better understanding the structure of components capable of inhibiting cell division.

The use of maximum correlations of TSM of the Atlantic dipole and precipitation in the state of Ceará

2024-05-22T13:23:20-03:00

It is known that the relationship between the ocean and the atmosphere is a major precursor of a wide range of meteorological events that influence the entire globe, including the rainfall regime in various regions. Understanding how these events explain precipitation is of constant interest. In this sense, the present work aimed to determine the maximum correlations between the Surface Sea Temperature (SST) anomalies in the Atlantic dipole region and precipitation in the State of Ceará. For this, we used observed and interpolated data of daily precipitation and SST anomalies from the National Oceanic and Atmospheric Administration (NOAA) for the period from 1982 to 2021. Using a tree algorithm between the maximum correlations of the Atlantic Dipole, based on in daily SST data, and precipitation we propose a methodological proposal to predict precipitation in the State of Ceará.