ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS

New challenges ahead in scientific publishing
Kellner AWA
Contribution of a special issue on Antarctic research to the AABC impact factor
Kellner AWA
Valorization of piassava fiber by its incorporation in adobe bricks
Gomes CDC, Delucis RA and Theisen KM
This study investigates valorization of piassava fiber through its incorporation in adobe bricks. The objective was to analyze the properties of adobe bricks reinforced with varying weight fractions of piassava fiber. The fibers were characterized for their chemical and physical characteristics, while the sand and clay were characterized for granulometry, XRD patterns, and EDX. Initial bricks were prepared with a constant piassava fiber weight fraction of 3% and varying sand:clay weight ratios. The mechanical properties of the adobe bricks were evaluated, and subsequent investigations involved variable fiber weight fractions of 0.5%, 1%, and 3%. Characterization included compressive characterization, apparent density, three-point bending, resistance to water erosion, and cracking behavior. The results showed that the physical and chemical characteristics of the fibers were consistent with the existing literature. The adobe bricks exhibited a range of apparent density values and compressive strength, with the S40C60P3 brick demonstrating higher strength and reduced crack visibility. The bricks with 3% fiber content outperformed others in terms of bending strength and displacement before fracture. Erosion tests revealed that higher fiber contents resulted in lower levels of mass loss and erosion depth. These findings highlight the potential of piassava fiber incorporation in adobe bricks for enhancing their properties.
Inhibition of human tumor cell migration by a rice-derived chimeric cysteine protease inhibitor
Dias-Oliveira M, Balbinott N, Ramos JMO, Vasconcellos JG, Guma FTCR, Zanatta G and Margis R
The cystatin superfamily includes proteins crucial for inhibiting cysteine proteases, enzymes involved in many biological processes. In plants, cystatins regulate seed germination, development, and pathogen defense. In humans, inhibiting legumain-type cysteine proteases offers a promising cancer treatment strategy, as this enzyme's expression often rises during tumor progression. We evaluated a novel rice-derived chimeric legumain inhibitor using in silico and in vitro methods. Computational simulations confirmed the inhibitor's stability and nanomolar affinity for legumain's active site. Post-expression and purification assays determined its kinetics and demonstrated its efficacy in reducing HT29 tumor cell migration and viability. Our findings suggest the chimeric Oryzacystatin I mutant with SNSL motifs is a promising candidate for cancer drug development.
TerraSAR-X SAR data for classification of ice-free areas and glacier facies on Fildes Peninsula, King George Island, Antarctica
Andrade AM, Michel RFM, Rosa KKD, Bremer UF, Schaefer CEGR and Simões JC
The region of the Maritime Antarctic suffers significantly from climate change, resulting in regional warming and consequently affecting coverage. This study characterized three surface zones of Collins Glacier and three other zones in ice-free areas on the Fildes Peninsula, which has an area of 29.6 km². We used TerraSAR-X satellite images from 2014 to 2016 and analyzed the influence of meteorological and environmental conditions on these surface zones. We used five images from the TerraSAR-X satellite, three of these data were obtained during the same period of fieldwork. The classification considered three classes on the glacier (higher moisture, transition in moisture, and lower moisture) and three on the ice-free areas (wet snow, transition wet snow-bare ice, and bare ice), using Maximum Likelihood and ISODATA methods. In low-altitude glaciers with maritime influence, such as Collins, monitoring variations in surface zones is essential because the continuous increase in exposed ice may indicate potential retreat. The TerraSAR-X images enabled the classification of land features, highlighting the potential for continuous monitoring in the Maritime Antarctic, regardless of weather conditions and solar illumination.
Specific immunohistochemical expression of Mmp-26 in prostatic adenocarcinoma
Silva RLD, Paes FLA, Silva SMSD, Santos F, Santana ES and Silva Neto JDC
Matrix metalloproteinases (MMP) have been identified as biomarkers for several diseases, including cancer. The increase in the expression of these enzymes has been related to greater tumor aggressiveness. MMP-26 is expressed constitutively in the endometrium and some cancer cells of epithelial origin. However, there is a lack of studies on its expression on prostatic carcinoma. In this study, the evaluation of MMP-26 reactivity by immunohistochemistry (IHC) was carried out in 150 paraffinized samples representative of benign and malignant prostatic lesions. 70 of the 150 samples showed IHC immunopositivity, being more prevalent in carcinoma cases (44 out of 70 cases) with moderate and strong intensity. The expression and intensity of the MMP-26 reaction showed a significant association with total PSA values. As expected, serum PSA levels were higher in cases of carcinoma than in prostatic hyperplasia or atrophy. Studies have demonstrated the potential of MMP-26 as a tumor marker, and our results have shown that its immunoexpression was useful to differentiate a group of benign and malignant samples in prostate tumors. This characteristic can assist in the predictive assessment and, consequently, in the development of new strategies for the diagnosis, prognosis, and treatment of prostate cancer.
One-Instant Flux Observer design for Three-Phase induction motor with reduced bound active load rejection speed controller
Hameed AH, Al-Samarraie SA and Humaidi AJ
Latency in flux observation has an adverse effect on the performance of observer-based field-oriented speed control for three-phase induction motor (IM). The reduction of the convergent rate of estimation errors could improve the performance of speed-controlled IM based on flux observers. The main contribution is to design a fast convergent flux observer, which provides bounded estimation error immediately after one instant of motor startup. The proposed flux observer fused barrier function adaptive mechanism with integral sliding mode control principle to yield BFISMO. Rigorous stability analysis has been conducted to achieve global flux estimation error ultimate boundedness. Moreover, three controllers have been designed. The first control design is devoted to flux control based on a backstepping controller, while the other two controllers' design is dedicated to rotor speed control of the motor. The speed controller is developed by combining the backstepping control with disturbance observers to estimate the unmatched load torque named quasi-sliding mode observer (QSMDO), and nonlinear disturbance observer (NLDO). Based on numerical simulations, the performance and efficacy of the proposed BFISMO have been assessed by conducting a comparison study to other observer techniques. The results showed the superiority of the proposed observer over the conventional versions.
Gas Chromatography-mass Spectrometry analysis, Biotoxicity and Antibiofilm Activities of Syzygium aromaticum against Corynebacterium diphtheriae
Alves MB, Nascimento KS, Araújo JMM, Firmo WCA, Mouchrek Filho VE, Sousa DA, Guaraldi ALM, Lima Neto LG and Sabbadini PS
The objective of this study was to investigate the chemical composition of Syzygium aromaticum essential oil (SAEO), both as its toxicity and biological activities on Corynebacterium diphtheriae. The essential oil (EO) was obtained by hydrodistillation and verified by GC-MS. The main chemical components were eugenol (48.79%), caryophyllene (44.29%) and α-humulene (4.87%). In vitro tests with human red blood cells, blood compatibility. SAEO showed high toxicity for Artemia salina and the bioassay on Tenebrio molitor larvae revealed an average survival rate of 80.00%. The antioxidant activity of SAEO was moderate (40.60%) using the phosphomolybdenum method. SAEO inhibited the growth of all C. diphtheriae strains tested at minimum inhibitory concentrations of 62.5-1000 µg mL-1 (strong to moderate). The minimum bactericidal concentration of SAEO was observed in two strains. Microorganisms cultivated in the presence of subinhibitory concentrations (subMIC) do not show morphological changes. The subMIC of SAEO inhibited in some strains, but in most cases, increased biofilm formation. In conclusion, the results of this study found that SAEO has an inhibitory effect against C. diphtheriae, representing an alternative antimicrobial therapy, although more in vivo biological studies, alone or in combination with occasional antimicrobials, should be carried out to better evaluate its effects.
Polyphenolic contents, antioxidant, and antimicrobial activities of Saccocalyx satureioides Coss. & Dur. essential oil and methanol extracts
Hendel N, Sarri D, Sarri M, Ghafsi AA and Benseghir A
The whole plant Saccocalyx satureioides, an endemic medicinal plant in Algeria, was evaluated for its polyphenolic contents, antioxidant and antimicrobial activities. The polyphenolic contents of the plant methanolic extracts ranged from 170.47 to 285.56 (µg GAEs/mg extract) and from 25.39 to 82.68 (µg QEs/mg extract), respectively. High antioxidant activity was registered: DPPH average IC50 = 14.68 µg/mL, and β-carotene average IC50 = 21.08 µg/mL. The essential oil and methanolic extracts from the aerial parts and roots were tested against bacteria and molds. Different methods, including disk diffusion, well diffusion, and microdilution tests for bacteria, were used. The essential oil (February and June harvest periods) value 1.25 µL/mL was the MIC and the MBC for all bacterial strains, except E. coli, K. pneumonia and Ps. aeruginosa. The average fungal inhibition of the methanol extracts ranged from 5.10 to 71.25%, except for F. oxysporum. The essential oil effect was 6.67-83.53% and 17.01-90.57% by the food poisoned and fumigation methods, respectively. The preliminary phytochemical evaluation demonstrated the high polyphenolic contents and effective antioxidant power of the plant extracts. This may have an essential role in the antimicrobial effectiveness and indicate that the plant contains high-quality bioactive molecules in addition to the essential oil.
Inhibitory Effect on the Tyrosinase Activity and Low Cytotoxicity of Monounsaturated Long-Chain Chelating Fatty Ester
Carvalho ASC, Pedrosa TN, Dantas Filho HA, Montenegro RC, Lima ES, Vasconcellos MC and Santos AS
In the present study, 5-Hydroxy-2-(Oleoyloxymethyl) -4H-pyran-4-one (KMO 3), and their chelated with Cu(II) and Fe(III) ions were synthesized to explore their inhibitory activity against tyrosinase and cytotoxicity. To this end, the structures of the obtained compounds were confirmed by ATR/FT-IR, 13C and 1H-NMR, and UV-vis techniques. The results show that chelating fatty ester presents the bands at 1567m, 1511w cm-1 attributed to the coordinated carbonyl (Cu(II)←[O=C]2), and the bands at 1540m, 1519m cm-1 which were attributed to the coordinated carbonyl (Fe(III)←[O=C]3). The inhibitory effect of chelating Oleic acid 2 (inhibition 68.3% ± 4.5) showed a factor of 19 times higher than free fatty acid (3.6% ± 3.2). IC50 Anti-tyrosinase activity of the Kojic acid 1 and KMO 3 compounds were 62.8 ± 6.6 µM and 77.6 ± 4.3 µM. The IC50 and IC90 values for tyrosinase inhibitory activity for chelating fatty ester and their complexes are values > 400 µM. Finally, the assay with the series showed no hemolytic activity (EC50> 250 μg mL-1), and not cytotoxic to B16F10, ACP-02, and human dermal fibroblast cells at 100 µM and showed no hemolytic potential at the concentration of IC50 250 µM.
Production of free fatty acids by enzymatic hydrolysis of residual frying oil using non-commercial lipases from Aspergillus niger
Dos Santos CJ, Santos RD, Cerqueira KS, Rodrigues JRS and Souza RR
Lipases are enzymes that have an important role in the industry for their wide use, giving rise to a great interest in industrial bioprocesses due to their versatility. One of the applications is the enzymatic hydrolysis of waste oils. This work consists of evaluating the production of lipases using several concentrations of residual frying oil (RFO) and different pHs, through ANOVA analysis. The production of free fatty acids was carried out by hydrolysis of RFO using noncommercial lipases produced in the previous step. The production of lipase enzymes was favored at pH 2.0, with an oil concentration of 1.5% (v/v) for a period of 24 hours, resulting in an enzyme activity of 141.90 U. mL-1 . The highest result of enzymatic hydrolysis of RFO was 20.70% in 40 minutes. This conversion was favored by increasing the concentration of the enzymatic extract. In this study, it was possible to obtain free fatty acids (FFAs) using a noncommercial enzyme and waste oil as an environmentally correct and low-cost alternative.
The first ornithocheiromorph humerus from Wuerho (Urho), China, with a new isotopic age of the Tugulu Group
Song J, Zhong Y, Jiang S and Wang X
Pterosaur remains are rare from the lowermost Cretaceous, hampering our understanding of the taxonomic and morphological diversities of pterosaurs during this period. The Lower Cretaceous Tugulu Group in Wuerho, China is renowned for hosting the Wuerho Pterosaurian Fauna (WPF), which has so far yielded numerous fossil remains of two dsungaripterid pterosaurs, Dsungaripterus weii and Noripterus complicidens. Here we report a partial ornithocheiromorph humerus from the WPF, representing a deeply divergent clade from Dsungaripteridae. The scarcity of ornithocheiromorphs from the WPF might be interpreted by niche partitioning with dsungaripterids. Meanwhile, we also report a U-Pb zircon age of 134.27 ± 0.36 Ma dated by LA-ICP-MS for the tuffaceous layer at the uppermost part of the Shengjinkou Formation, confirming the Valanginian age of the WPF presented by a previous study. The Wuerho region is one of the few localities producing abundant pterosaur fossils and the only one with an earliest Cretaceous age. The new finding here also suggests that Ornithocheiromorpha had rapidly diversified and achieved a global distribution during the earliest Cretaceous, presumably through a series of modifications on the locomotor apparatus including the warped deltopectoral crest of the humerus, which might substantially improve their flight efficiency.
Tooth replacement of the filter-feeding pterosaur Forfexopterus and its implications for ecological adaptation
Zhou CF and Fan F
A "comb-dentition", characterized by long, needle-like, and closely-spaced teeth, is found in the ctenochasmatid pterosaurs as an adaptation for filter-feeding. However, little is known about their tooth replacement pattern, hindering our understanding of the development of the filter-feeding apparatus of the clade. Here, we describe the tooth replacement of the pterosaur Forfexopterus from the Jehol Biota based on high-resolution X-ray Computed Tomography (CT) reconstruction. As in the ornithocheirid Coloborhynchus, the tooth germs are relatively medially positioned along the middle line; the replacement teeth erupt at the posteromedial side of the functional tooth; no more than one replacement tooth present in each alveolus. The replacement teeth are less than half of the length of the full-grown tooth, and alternatively positioned along the tooth row. The alternatively-positioned young and mature functional teeth are dominant and abrased, maintaining the active tooth-tooth occlusion of the filter-feeding apparatus. Reconstruction of Zahnreihen shows an average Z-spacing of 2.02, comparable to that of the simple alternate replacement (Z-spacing = 2) between odd- and even-numbered tooth positions in reptiles. Based on comparisons with Balaenognathus, Ctenochasma, and Pterodaustro, the tooth replacement pattern appears to be varied in ctenochasmatids, and needs to be further studied in the future.
Biochemical and histological effects of the subchronic treatment with a beer containing Baccharis dracunculifolia in an experimental model of diabetes
Pereira RA, Hey A, Jesus AB, Marin AT, Fiorini F, Corassa R, Goes AKS, Grolli M, Dangui AZ, Wouk J, Prasniewski A, Oldoni TLC, Parpinello GP, Tylewicz U, Carraro E and Malfatti CRM
This article reports the development of a beer made with Baccharis dracunculifolia and its application in an experimental model of diabetes. Initially, the production of the beverage was standardized in order to incorporate the plant extract properly. Next, the beer was analyzed by the UHPLC-MS to identify the substances present. Among others, caffeic acid (5.85 mg / L), m-coumaric acid (5.16 mg / L), pinocembrin (2.99 mg / L), chrysin (10.86 mg / L), myricetin (1.73 mg / L) and spathulenol (9.30 mg / L) were found. Animal tests indicate improvement in biochemical and histological parameters of STZ-induced Wistar rats that ingested the beer made with the plant. The antidiabetic potential of this beverage was observed in the different tests that evaluated insulin resistance and the decrease of the clinical manifestations of diabetes in animals. The use of the drink as an adjunct in clinical treatments for DM2 may be useful, especially in suppressing the oxidative damage caused by the disease.
Soilscapes from Byers Peninsula, Maritime Antarctic: landform-lithology controls in soil formation
Silva JPD, Francelino MR, Faria ALL, Palma HP, Oliveira IA, Souza JJLL and Schaefer CEGR
The Byers Peninsula, the largest ice-free area in Maritime Antarctica, is vital for studying landscape-scale natural processes due to its diverse periglacial landforms. This study aim to characterize the soils and environments of its southern sector, focusing on soil-landform-lithology interactions. Thirty-seven soil profiles were classified, collected, and chemically and physically analyzed. Principal component analysis explored relationships among variables in these profiles and 36 others from the Peninsula project database. The soils are generally shallow, with lithic or paralithic contact within the first meter. Four main soil groups were identified: patterned-ground soils on plateaus, ornithogenic soils, non-ornithogenic soils, and non-ornithogenic sodic and sandy soils on beaches and marine terraces. The Peninsula, divided into six geological units, represents a diverse periglacial morphogenetic system. Sixteen landform types were identified, each associated with different processes, topographies, lithologies, altitudes, and orientations, highlighting the importance of periglacial morphogenesis. Stable soilscapes, such as upper cryoplanation platforms, raised beaches, volcanic plugs, and ornithogenically influenced areas, show greater soil development and weathering. In contrast, dynamic periglacial landforms like scree stony slopes and talus exhibit minimal soil development and instability. The Byers Peninsula's pedodiversity is due to its varied lithologies, landforms, extensive ornithogenic influences from seabirds, and long-term vegetation establishment.
Lectin-carbohydrate analysis by molecular dynamics: Parkia lectins case study
Nascimento KS, Osterne VJS, Oliveira MV, Domingos JLC, Ferreira WP, Damme EJMV, Cavada BS and Pinto-Junior VR
Understanding lectin-carbohydrate interactions at the structural and molecular levels is crucial to the field of lectins, as the diverse roles and biological activities exhibited by these proteins are fundamentally linked to their specific binding to target glycoconjugates. This study aimed to apply molecular dynamics to analyze the structure and binding properties of Parkia lectins. 3D structures of Parkia platycephala and P. biglobosa lectins, both unliganded and in complex with D-mannose, were used as inputs for simulations. The trajectories data enabled the study of stability, carbohydrate-binding interactions, and intermonomeric contacts for both proteins. The results revealed stable binding of D-mannose within the lectin domains and their binding mode at each of the three domains, displaying consistent binding motifs across the sites, with slight variations between the lectins and other Jacalin-related lectins. Despite these variations, the binding energies of the lectins with the ligand, as estimated using MM/GBSA, demonstrated favorable interactions in all cases. The dimeric interfaces of both lectins could be identified, and the main contacts have been mapped. These findings enhance our understanding of lectin-carbohydrate interactions and provide insights into the structural properties of Parkia lectins for potential biological and therapeutic applications.
DNA metabarcoding reveal hidden diversity of periphytic eukaryotes on marine Antarctic macroalgae
Câmara PEAS, Pellizzari FM, Lopes FAC, Amorim ET, Bones FLV, Anjos DA, Carvalho-Silva M, Convey P and Rosa LH
Polar marine macroalgae thrive in extreme conditions, often displaying geographic isolation and high degree of endemism. The "phycosphere" refers to the zone around the algae inhabited by microrganisms. Our study used DNA metabarcoding to survey the eukaryotic communities associated with seven seaweed species obtained at King George Island (South Shetland Islands, maritime Antarctic), including two Rhodophyta, two Chlorophyta and three Phaeophyceae. The ITS2 region was used as a barcode and our analysis yielded 77 eukaryotic ASVs spanning five Kingdoms (Fungi, Metazoa, Chromista, Protozoa, and Viridiplantae) and ten phyla (Ascomycota, Basidiomycota, Cercozoa, Ciliophora, Ochrophyta, Amebozoa, Chlorophyta, Rhodophyta, Bryophyta and Cnidaria). Additionally, we identified 14 potential new occurrence records for Antarctica. Ciliates and green algae were the most species-rich groups. The most abundant assigned associated species was Monostroma angicava (Chrorophyta). Within the macroalgal, the Chlorophyceans Ulothrix sp. hosted the greatest number of taxa, followed by Monostroma hariotii. Our data suggested that Antarctic macroalgae host a rich diversity of associated organisms and the biodiversity associated with the phycosphere remains underestimated.
First report of Penicillium brevicompactum causing disease in Pleurotus ostreatus
Silva RSA, Jarek TM, Jesus GL, Oliveira GD and Cuquel FL
Oyster mushroom (Pleurotus ostreatus) is the second most produced mushroom globally, but increased production is linked to new diseases. This study reports the first occurrence of Penicillium brevicompactum on P. ostreatus mushrooms. Symptoms, identified in the primordia, include atrophy, malformation, drying, and sporulation, causing up to 100% losses. The pathogen was confirmed with 99% identity via ITS region analysis and phylogenetic comparison. The research highlights P. brevicompactum's infection of mushroom primordia, emphasizing the need for pathogen identification and preventive measures to mitigate production losses.
Antarctic nematodes survival in Martian and Lunar regolith simulants under terrestrial conditions
Amaral CRL, Bones FLV, Freitas AC, Goldenberg-Barbosa R, Magalhães MGP, Moreira LM, Anjos D, Donato A, Amorim A and Câmara PEAS
The exploration of extraterrestrial environments has become a focal point of scientific inquiry, driven by advancements in technology and a growing interest in the potential for life beyond Earth. This study investigates the adaptability of Antarctic nematodes, known for thriving in extreme cold and isolation, to simulated Martian (MGS-1) and Lunar (LMS-1) soils. The experiment revealed differential responses in nematode survivability to the two simulants, with Lunar soil demonstrating better adaptability compared to Martian soil. Our study provides valuable insights into the potential survivability of Antarctic nematodes on real Martian and Lunar substrates with the use of the MGS-1 and the LMS-1 under terrestrial conditions. The observed results suggest differential survival responses to Lunar (6.92 ± 0.74) and Martian (5.58 ± 1.91) regolith simulants and highlight the complexity of factors influencing organismal survival. Considering their crucial role in soil food webs, and their relation with nutrient cycling and carbon dioxide emissions, the observed capacity of nematodes to thrive in Martian and Lunar regoliths positions them as potential candidates to sustain human habitats, helping on the development of in-situ resource utilization (ISRU) systems, and forming the basis for a biological life-support system to facilitate human survival in extraterrestrial environments.
A third volume commemorating forty years of the Brazilian Antarctic Program
Simões JC, Sayão JM and Alder V
Urgent call: Environmental mismanagement after historical flood amplifies Rio Grande do Sul's ecological crisis in south of Brazil
Beys-DA-Silva WO, Faustino AM, Schrank A, Vainstein MH and Santi L