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Abstract Precise and accurate measurement of metacognitive phenomena has never been more necessary than in today's fast-paced world in which vast quantities of information are readily available to the learner. The MAI, Jr. (see Sperling et al., 2002) is a widely used, 18-question, self-report measure of metacognitive awareness. However, this measure has not been re-examined for construct validity and internal consistency since its inception in 2002. In this manuscript we report on our findings of a 2-year study in which we worked to validate a shortened version of the MAI, Jr. Over the course of 2 years, 601 students in grades 6-8 participated in our study. In each year, data was examined using exploratory factor analysis with common factor extractions (principal axis factoring [PAF]) and oblique rotations (promax). The results of this study support the validation of a shortened, 7-item, scale. We discuss why shorter measures with appropriate construct validity and internal consistency are preferred.
Resumen La medición precisa y exacta de los fenómenos metacognitivos nunca ha sido más necesaria que en el acelerado mundo actual, en el que el alumno dispone de grandes cantidades de información. El MAI, Jr. (ver Sperling et al., 2002) es una medida de autoinforme de conciencia metacognitiva de 18 preguntas ampliamente utilizada. Sin embargo, esta medida no ha sido reexaminada en cuanto a validez de constructo y consistencia interna desde su inicio en 2002. En este documento se informa sobre los hallazgos de un estudio de 2 años en el que trabajamos para validar una versión abreviada del MAI, Jr. En el transcurso de 2 años, 601 estudiantes de 6.º a 8.º grado participaron en nuestro estudio. En cada año, los datos se examinaron mediante análisis factorial exploratorio con extracciones de factores comunes (factorización del eje principal [PAF]) y rotaciones oblicuas (promax). Los resultados de este estudio respaldan la validación de una escala abreviada de 7 ítems. Se discute por qué se prefieren medidas más cortas con validez de constructo y consistencia interna apropiadas.
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Brazilian nuts are native to the Amazon rainforest and are considered a non-timber forest-product of extreme economic importance to local populations. This study evaluated the lipid profile, bioactive compounds, and oxidative stability of semi-defatted Brazilian nut flour oil (BNSDFO) obtained using pressurized fluids (n-propane at 40 °C and 2, 4, and 8 MPa or a CO2/n-propane mixture at 40 °C and 12 MPa). A Brazilian nut kernel oil (BNKO) processed by conventional cold pressing was also obtained. The BNKO showed a higher concentration of total phenolic compounds and saturated fatty acids, higher antioxidant activity, and the presence of gallic acid derivatives. The oils extracted using pressurized fluids showed a higher concentration of linoleic acid, ß-sitosterol, and polyunsaturated fatty acids. The utilization of pressurized n-propane resulted in higher yields (13.7 wt%), and at intermediate pressures (4 MPa), the product showed myricetin 3-O-rhamnoside and higher oxidative stability (OSI, 12 h) than at lower pressures (2 MPa). The CO2/n-propane mixture of pressurized solvents resulted in higher concentrations of squalene (4.5 times), the presence of different phenolic compounds, and a high OSI (12 h) but lower yield (2.2 wt%). In conclusion, oils with better fatty acid profiles (oleic e linoleic acids), phytosterol composition, and suitable radical scavenging activity may be obtained using pressurized fluids and Brazilian nut flour, a byproduct of oil extraction. The mixture of solvents may improve the concentration of squalene, whereas using only n-propane may increase oil yield.
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Improper thermal cycles on duplex stainless steels can lead to the formation of detrimental phases or alter the proportion of ferrite and austenite phases, thus influencing the material's mechanical properties and corrosion resistance. Therefore, this study aimed to evaluate the effect of aging (at 850 and 950 °C) and solubilization (at 1000 and 1150 °C) thermal treatments on microstructure, indentation hardness, elasticity modulus, and susceptibility to intergranular corrosion of UNS S32205 duplex stainless steel. The sigma phase (σ) formation in the aged samples, with hardness values between 8 and 10 GPa, was confirmed. Furthermore, the pieces treated from 1000 °C upwards showed that increased temperature favored the formation of more equiaxial grains and the ferrite fraction growth. The thermal treatments barely affected the elasticity modulus of austenite and ferrite grains, increasing the hardness of ferrite. The effect of sulfuric acid concentration in the intergranular corrosion was evaluated. Also, the deconvolution of the corrosion curves permits the determination of the influence of the different phases in the corrosion performance. These tests revealed sensitization only at the σ phase grain boundaries in the samples treated at 850 °C in electrolytes containing H2SO4 2.5 mol/L and HCl 1 mol/L. Although the treatment at 950 °C led to the σ phase formation, its higher corrosion resistance was ascribed to the lower volumetric fraction of this phase, its morphology, and its increased Cr mobility compared to the 850 °C treatment. Therefore, it was shown that the σ characteristics and the sulfuric acid concentrations are determining factors in the UNS S32205 intergranular corrosion resistance.
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Inflammation plays a pivotal role in the pathogenesis of primary and post-essential thrombocythemia or post-polycythemia vera myelofibrosis (MF) in close cooperation with the underlying molecular drivers. This inflammatory state is induced by a dynamic spectrum of inflammatory cytokines, although recent evidence points to the participation of additional soluble inflammatory mediators. Damage-associated molecular patterns (DAMPs) represent endogenous signals released upon cell death or damage which trigger a potent innate immune response. We assessed the contribution of two prototypical DAMPs, HMGB1 and S100A8/A9, to MF inflammation. Circulating HMGB1 and S100A8/A9 were elevated in MF patients in parallel to the degree of systemic inflammation and levels increased progressively during advanced disease stages. Patients with elevated DAMPs had higher frequency of adverse clinical features, such as anemia, and inferior survival, suggesting their contribution to disease progression. Monocytes, which are key players in MF inflammation, were identified as a source of S100A8/A9 but not HMGB1 release, while both DAMPs correlated with cell death parameters, such as serum LDH and cell-free DNA, indicating that passive release is an additional mechanism leading to increased DAMPs. HMGB1 and S100A8/A9 promote inflammation through binding to Toll-like receptor (TLR) 4, whereas the former also binds TLR2. Monocytes from MF patients were shown to be hyperactivated at baseline, as reflected by higher CD11b and tissue factor exposure and increased expression levels of proinflammatory cytokines IL-1ß and IL-6. Patient monocytes showed preserved TLR4 and TLR2 expression and were able to mount normal or even exacerbated functional responses and cytokine upregulation following stimulation of TLR4 and TLR2. Elevated levels of endogenous TLR ligands HMGB1 and S100A8/A9 coupled to the finding of preserved or hyperreactive TLR-triggered responses indicate that DAMPs may promote monocyte activation and cytokine production in MF, fueling inflammation. Plasma IL-1ß and IL-6 were elevated in MF and correlated with DAMPs levels, raising the possibility that DAMPs could contribute to cytokine generation in vivo. In conclusion, this study highlights that, in cooperation with classic proinflammatory cytokines, DAMPs represent additional inflammatory mediators that may participate in the generation of MF inflammatory state, potentially providing novel biomarkers of disease progression and new therapeutic targets.
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Alarminas , Calgranulina A , Calgranulina B , Proteína HMGB1 , Inflamación , Monocitos , Mielofibrosis Primaria , Humanos , Proteína HMGB1/sangre , Proteína HMGB1/metabolismo , Calgranulina A/sangre , Calgranulina B/sangre , Masculino , Femenino , Monocitos/inmunología , Monocitos/metabolismo , Anciano , Persona de Mediana Edad , Alarminas/metabolismo , Alarminas/inmunología , Inflamación/inmunología , Mielofibrosis Primaria/inmunología , Mielofibrosis Primaria/metabolismo , Anciano de 80 o más Años , Receptores Toll-Like/metabolismo , Citocinas/metabolismo , Adulto , Receptor Toll-Like 4/metabolismo , BiomarcadoresRESUMEN
Canopy shade enhances the activity of PHYTOCHROME INTERACTING FACTORs (PIFs) to boost auxin synthesis in the cotyledons. Auxin, together with local PIFs and their positive regulator CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), promotes hypocotyl growth to facilitate access to light. Whether shade alters the cellular redox status thereby affecting growth responses, remains unexplored. Here, we show that, under shade, high auxin levels increased reactive oxygen species and nitric oxide accumulation in the hypocotyl of Arabidopsis. This nitroxidative environment favored the promotion of hypocotyl growth by COP1 under shade. We demonstrate that COP1 is S-nitrosylated, particularly under shade. Impairing this redox regulation enhanced COP1 degradation by the proteasome and diminished the capacity of COP1 to interact with target proteins and to promote hypocotyl growth. Disabling this regulation also generated transversal asymmetries in hypocotyl growth, indicating poor coordination among different cells, which resulted in random hypocotyl bending and predictably low ability to compete with neighbors. These findings highlight the significance of redox signaling in the control of diffuse growth during shade avoidance.
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Proteínas de Arabidopsis , Arabidopsis , Hipocótilo , Especies Reactivas de Oxígeno , Ubiquitina-Proteína Ligasas , Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Especies Reactivas de Oxígeno/metabolismo , Hipocótilo/crecimiento & desarrollo , Hipocótilo/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Óxido Nítrico/metabolismo , Ácidos Indolacéticos/metabolismo , Luz , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Oxidación-Reducción , Transducción de SeñalRESUMEN
In the search for more sustainable remediation strategies for PAH-contaminated soils, an integrated application of thermal remediation and bioremediation (TEB) may allow the use of less impacting temperatures by associating heating to biological degradation. However, the influence of heating on soil microbiota remains poorly understood, especially in soils from tropical regions. This work investigated the effects of low-temperature heating on creosote-contaminated soil bacteria. We used culture-dependent and 16 S rRNA sequencing methods to compare the microbial community of soil samples heated to 60 and 100 oC for 1 h in microcosms. Heating to 60 °C reduced the density of cultivable heterotrophic bacteria compared to control soil (p < 0.05), and exposure to 100 °C inactivated the viable heterotrophic community. Burkholderia-Caballeronia-Paraburkholderia (BCP) group and Sphingobium were the predominant genera. Temperature and incubation time affected the Bray-Curtis dissimilarity index (p < 0.05). At 60 °C and 30 days incubation, the relative abundance of Sphingobium decreased and BCP increased dominance. The network of heated soil after 30 days of incubation showed fewer nodes and edges but maintained its density and complexity. Both main genera are associated with PAH degradation, suggesting functional redundancy and a likely potential of soil microbiota to maintain biodegradation ability after exposure to higher temperatures. We concluded that TEB can be considered as a potential strategy to bioremediate creosote-contaminated soils, allowing biodegradation in temperature ranges where thermal remediation does not completely remove contaminants. However, we recommend further research to determine degradation rates with this technology.
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Sparisoma species (parrotfish) comprise an important functional group contributing to coral-reef resilience. The morphological diagnostic characteristics for species identification are clearly described for adult forms but not for the early stages. Consequently, many taxonomical listings of Sparisoma larvae are restricted to the genus level. The aims of this study are to determine whether the morphological and molecular identification techniques are useful to assign the species taxonomic level to Sparisoma larvae occurring in the Gulf of Mexico and whether there is a set of diagnostic features that could be used to discriminate between species in larvae of different developmental stages. Morphological assignment of Sparisoma was performed based on morphological and meristic features for 30 larvae collected in the Gulf of Mexico from late August to mid-September 2015. To corroborate and complement the morphological assignments, molecular identification was carried out using DNA sequences from regions of two mitochondrial genes, mitochondrial cytochrome oxidase I (mtDNA COI) and mitochondrial 16S rRNA (mtDNA 16S rRNA). COI and 16S gene trees for Sparisoma and related fish taxa were constructed using sequences available in the NCBI (National Center for Biotechnology Information) GenBank and BOLD (Barcode of Life Data) databases. Two morphotypes were identified based on morphology, but no diagnostic characteristics for species discrimination were found. Molecular identification, in contrast, successfully discriminated four early development stages of Sparisoma atomarium, three stages of Sparisoma radians, and two stages of Sparisoma chrysopterum and Sparisoma aurofrenatum, therefore demonstrating the successful and necessary application of molecular taxonomic approaches for species-level identifications of Sparisoma larvae.
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Early exposure to stressors affects how the organism reacts to stimuli, its emotional state throughout life, and how it deals with emotional memories. Consequently, it may affect susceptibility to psychopathology later in life. We used an animal model of early stress by maternal separation to study its potential impact on the extinction of aversive memories and anxiety-like behavior in adulthood, as well as its effects on mitochondrial functionality, inflammatory and astrocytic markers in the amygdala. We also assessed whether a diet enriched with linseed oil, known for its high content in omega-3 fats, could be used to attenuate the behavioral and neurochemical effects of early stress. Litters of Wistar rats were divided into controls (intact) or subjected to maternal separation (MS). They were subdivided into two groups receiving isocaloric diets enriched in soy or linseed oils at weaning. In adulthood, the animals were exposed to the open field and the elevated plus maze, to evaluate exploratory activity and anxiety-like behavior. They were also trained in a context of fear conditioning, and afterward subjected to an extinction session, followed by a test session to evaluate the extinction memory. Amygdalae were evaluated for inflammatory cytokines (interleukin (IL)-1beta, IL-6, and tumor-necrose factor (TNF)-alpha), mitochondrial functionality, and astrocyte markers (glial fibrillary acidic protein - GFAP, S100B, and glutamine synthetase activity). MS induced anxiety-like behavior in the elevated plus-maze, which was reversed by a diet enriched in linseed oil offered from weaning. When testing the memory of an extinction session of fear conditioning, MS animals showed more freezing behavior. MS males receiving a linseed oil-enriched diet had lower functional mitochondria in the amygdala. In addition, MS led to increased inflammatory cytokines, particularly IL-1beta, and the diet enriched in linseed oil further increased these levels in MS animals. MS also increased S100B levels. These results point to a higher emotionality presented by MS animals, with higher levels of inflammatory cytokines and S100B. While a diet enriched in linseed oil attenuated anxiety-like behavior, it further altered amygdala IL-1beta and reduced mitochondria functionality, particularly in males. MS also increased glutamine synthetase activity in the amygdala, and this effect was higher when the animals received a diet enriched in linseed oil, particularly in females. In conclusion, these results point to MS effects on emotional behavior, and neurochemical alterations in the amygdala, with sex-specific effects. Although a diet enriched in linseed oil appears to be able to reverse some of MS behavioral effects, these results must be considered with caution, since biochemical parameters could be worsened in MS animals receiving a linseed oil-enriched diet. This knowledge is important for the understanding of mechanisms of action of strategies aiming to reverse early stress effects, and future studies are warranted to determine possible interventions to promote resilience.
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Psoriasis is an immune-mediated chronic inflammatory disease that causes major psychosocial impact. Topical corticosteroids represent the standard pharmacological treatment for mild-to-moderate disease, but their local and systemic adverse effects reinforce the need for treatment innovations. Here we developed lamellar phase-based formulations for topical delivery of a hybrid dexamethasone and hydrogen sulfide (H2S) donor molecule (Dexa-TBZ), aiming to potentiate the effects of the glucocorticoid with H2S. They offer the possibility to obtain precursor formulations free of water that originate lamellar phases upon water addition, preventing drug hydrolysis during storage. Two groups of formulations were developed varying the surfactants and oil phase types and content. Systems containing 20 and 70 % of water formed, respectively, bulk lamellar phase and a more fluid formulation consisting of dispersed droplets (< 1000 nm) stabilized by lamellar phase. Both presented pseudoplastic behavior. Dexa-TBZ was incorporated at 1 %, remaining stable for 8 h. Drug content decreased to â¼80 % after 1 week in precursor formulations free of water, but remained stable after that. Without causing changes to the cutaneous barrier function ex vivo or to the histological structure of the skin in vivo, the formulation containing phosphatidylcholine as surfactant and 70 % of water promoted 1.8- and 2.7-fold increases in Dexa-TBZ penetration in the stratum corneum and epidermis+dermis, respectively, compared to a control solution, demonstrating their potential applicability as topical delivery systems.
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Administración Cutánea , Dexametasona , Sulfuro de Hidrógeno , Piel , Sulfuro de Hidrógeno/administración & dosificación , Sulfuro de Hidrógeno/química , Dexametasona/administración & dosificación , Dexametasona/química , Animales , Piel/metabolismo , Piel/efectos de los fármacos , Absorción Cutánea/efectos de los fármacos , Nanoestructuras/administración & dosificación , Nanoestructuras/química , Sistemas de Liberación de Medicamentos/métodos , Humanos , Psoriasis/tratamiento farmacológico , Corticoesteroides/administración & dosificación , Corticoesteroides/química , Antiinflamatorios/administración & dosificación , Antiinflamatorios/químicaRESUMEN
The introduction of optimized nanoheaters, which function as theranostic agents integrating both diagnostic and therapeutic processes, holds significant promise in the medical field. Therefore, developing strategies for selecting and utilizing optimized plasmonic nanoheaters is crucial for the effective use of nanostructured biomedical agents. This work elucidates the use of the Joule number (Jo) as a figure of merit to identify high-performance plasmonic theranostic agents. A framework for optimizing metallic nanoparticles for heat generation was established, uncovering the size dependence of plasmonic nanoparticles optical heating. Gold nanospheres (AuNSs) with a diameter of 50 nm and gold nanorods (AuNRs) with dimensions of 41×10 nm were identified as effective nanoheaters for visible (530 nm) and infrared (808 nm) excitation. Notably, AuNRs achieve higher Jo values than AuNSs, even when accounting for the possible orientations of the nanorods. Theoretical results estimate that 41×10 nm gold nanorods have an average Joule number of 80, which is significantly higher compared to larger rods. The photothermal performance of optimal and suboptimal nanostructures was evaluated using photoacoustic imaging and photothermal therapy procedures. The photoacoustic images indicate that, despite having larger absorption cross-sections, the large nanoparticle volume of bigger particles leads to less efficient conversion of light into heat, which suggests that the use of optimized nanoparticles promotes higher contrast, benefiting photoacoustic-based procedures in diagnostic applications. The photothermal therapy procedure was performed on S180-bearing mice inoculated with 41×10 nm and 90×25 nm PEGylated AuNRs. Five minutes of laser irradiation of tumor tissue with 41×10 nm produced an approximately 9.5% greater temperature rise than using 90×25 AuNRs in the therapy trials. Optimizing metallic nanoparticles for heat generation may reduce the concentration of the nanoheaters used or decrease the light fluence for bioscience applications, paving the way for the development of more economical theranostic agents.
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Over the past two decades, zoonotic sporotrichosis transmitted by naturally infected cats has become hyperendemic in Rio de Janeiro, Brazil. Sporothrix brasiliensis is the main agent involved. However, there are other forms of transmission of sporotrichosis. The aim of this study was to evaluate and associate the epidemiological, clinical and therapeutic data and the susceptibility of Sporothrix spp. to antifungal drugs in 43 non-zoonotic sporotrichosis cases. Forty-three clinical strains of Sporothrix were identified by partial sequencing of the calmodulin gene. An antifungal susceptibility test of amphotericin B, terbinafine, itraconazole, posaconazole and isavuconazole was performed according to the broth microdilution method. Most patients were male (55.8%). Regarding the source of infection, 21 patients (48.8%) reported trauma involving plants and/or contact with soil. Sporothrix brasiliensis was the predominant species (n = 39), followed by S. globosa (n = 3) and S. schenckii (n = 1). Sporothrix brasiliensis was associated with all the sources of infection, reinforcing previous data showing the presence of this species in environmental sources, as well as with all the clinical forms, including severe cases. One clinical strain of Sporothrix brasiliensis was classified as a non-wild-type strain for amphotericin B and another for itraconazole. S. schenckii was classified as non-WT for all the antifungals tested. In this context, it is important to emphasize that non-zoonotic sporotrichosis still occurs in the state of Rio de Janeiro, with S. brasiliensis as the main etiological agent, primarily associated with infections acquired after traumatic inoculation with plants and/or soil contact, followed by S. globosa and S. schenckii. In addition, non-WT strains were found, indicating the need to monitor the antifungal susceptibility profile of these species. It is crucial to investigate other natural sources of S. brasiliensis to better understand this fungal pathogen and its environment and host cycle.
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We searched for an extraction method that would allow a precise quantification of metal(loid)s in milligram-size samples using high-resolution graphite furnace atomic absorption spectrometry (HR-GFAAS). We digested biological (DORM-4, DOLT-5 and TORT-3) and sediment (MESS-4) certified reference materials (CRMs) using nitric acid in a drying oven, aqua regia in a drying oven, or nitric acid in a microwave. In addition, we digested MESS-4 using a mixture of nitric and hydrofluoric acids in a drying oven. We also evaluated the effect of sample size (100 and 200 mg) on the extraction efficiency. Nitric acid extraction in a drying oven yielded the greatest recovery rates for all metal(loid)s in all tested CRMs (80.0 %-100.0 %) compared with the other extraction methods tested (67.3 %-99.2 %). In most cases, the sample size did not have a significant effect on the extraction efficiency. Therefore, we conclude that nitric acid digestion in a drying oven is a reliable extraction method for milligram-size samples to quantify metal(loid)s with HR-GFAAS. This validated method could provide substantial benefits to environmental quality monitoring programs by significantly reducing the time and costs required for sample collection, storage, transport and preparation, as well as the amount of hazardous chemicals used during sample extraction and analysis. â¢Sample digestion with nitric acid in a drying oven yielded the greatest recovery rates of metal(loid)s from biological and sediment certified reference materials.â¢The recovery rates of metal(loid)s from biological and sediment certified reference materials using nitric acid digestion in a drying oven ranged from 73 % to 100 %.â¢Digestion with nitric acid in a drying oven is a simple and reliable method to extract small size environmental samples for metal(loid)s quantification by high-resolution graphite furnace atomic absorption spectrometry.
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The Mi-1.2 gene confers resistance to a wide range of Meloidogyne species, being the most important resistance factor employed in tomato breeding so far. However, many aspects related to the interaction of Mi-1.2-carrying tomato cultivars and virulent/avirulent Meloidogyne populations have not yet been clarified. Herein, comparative histopathological analyses were carried after inoculation of the homozygous (Mi-1.2/Mi-1.2) tomato rootstock 'Guardião' and the susceptible cultivar 'Santa Clara' (mi-1.2/mi-1.2) with virulent and avirulent populations of M. javanica. In the susceptible control, it was possible to visualize second stage juveniles (J2) of avirulent population and feeding sites from 2 to 30 days after infection (DAI) with females reaching maturity at 24-34 DAI. In the resistant rootstock, the Mi-1.2 gene-mediated resistance was related mainly to early defense responses (pre-infection and hypersensitive reaction), which led to an immunity-like phenotype that completely prevented the reproduction of the avirulent Meloidogyne population. On the other hand, J2s of the virulent M. javanica population were able to penetrate roots much more than the avirulent population, migrated and developed normally, showing intense and similar pattern of penetration from 4 to 34 DAI in the root tissues of both resistant and susceptible tomato genotypes. The total numbers of J2, J3, J4, and females counted in 'Santa Clara' for the virulent population of M. javanica were higher than in 'Guardião'.
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Monitoring of stream water quality is a key element of water resource management worldwide, but methods that are commonly used in temperate habitats may not be appropriate in humid tropical systems. We assessed the influence of four land uses on microbial water quality in 21 streams in the Panama Canal Watershed over a one-year period, using a common culture-based fecal indicator test and 16S rDNA metabarcoding. Each stream was located within one of four land uses: mature forest, secondary forest, silvopasture, and traditional cattle pasture. Culturing detected total coliforms and Escherichia coli across all sites but found no significant differences in concentrations between land uses. However, 16S rDNA metabarcoding revealed variability in the abundance of coliforms across land uses and several genera that can cause false positives in culture-based tests. Our results indicate that culture-based fecal indicator bacteria tests targeting coliforms may be poor indicators of fecal contamination in Neotropical oligotrophic streams and suggest that tests targeting members of the Bacteroidales would provide a more reliable indication of fecal contamination.
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Enterobacteriaceae , Monitoreo del Ambiente , Heces , Ríos , Microbiología del Agua , Heces/microbiología , Ríos/microbiología , Monitoreo del Ambiente/métodos , Enterobacteriaceae/aislamiento & purificación , Enterobacteriaceae/genética , Escherichia coli/aislamiento & purificación , Clima Tropical , ARN Ribosómico 16S/genética , Calidad del AguaRESUMEN
To assess microbial dynamics during anaerobic digestion (AD) of sewage sludge (SWS) from a municipal Wastewater Treatment Plant (WWTP), a Biochemical Methane Potential (BMP) assay at 37 °C under mono-digestion conditions was conducted. Utilizing the Illumina MiSeq platform, 16S ribosomal RNA (rRNA) gene sequencing unveiled a core bacterial community in the solid material, showcasing notable variations in profiles. The research investigates changes in microbial communities and metabolic pathways to understand their impact on the efficiency of the digestion process. Prior to AD, the relative abundance in SWS was as follows: Proteobacteria > Bacteroidota > Actinobacteriota. Post-AD, the relative abundance shifted to Firmicutes > Synergistota > Proteobacteria, with Sporanaerobacter and Clostridium emerging as dominant genera. Notably, the methanogenic community underwent a metabolic pathway shift from acetoclastic to hydrogenotrophic in the lab-scale reactors. At the genus level, Methanosaeta, Methanolinea, and Methanofastidiosum predominated initially, while post-AD, Methanobacterium, Methanosaeta, and Methanospirillum took precedence. This metabolic transition may be linked to the increased abundance of Firmicutes, particularly Clostridia, which harbor acetate-oxidizing bacteria facilitating the conversion of acetate to hydrogen.
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BACKGROUND: A colorimetric method for the quantification of hydrogen sulfide (H2S) produced in microbial fermentations was developed using lead gelled alginate microparticles packed in glass columns. The formation of a lead sulfide complex, between H2S and lead ion (Pb2+) immobilized on the microparticles, allowed simple and accurate quantification by colorimetry. RESULTS: The microparticle-loaded columns were calibrated and showed significant analytical sensitivity. The calibration curve of the system showed a correlation coefficient (r2) of 0.995 and a detection limit of 1.29 ± 0.02 µg L-1. The application of the columns in laboratory wine fermentations was able to detect variations in H2S production from 10.6 to 23.5 µg L-1 by increasing the sugar content in the medium, and from 10.6 to 3.2 µg L-1 with decreasing nitrogen content in the medium. CONCLUSION: Validation of the proposed method was carried out by determining H2S in a vinic fermentation model, the results of which were compared with those obtained using a reference chemical method. The data obtained showed no statistically significant differences between the two methods, confirming the reliability and accuracy of the developed system. © 2024 Society of Chemical Industry.
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Patients with advanced Parkinson's disease often suffer from severe gait and balance problems, impacting quality of live and persisting despite optimization of standard therapies. The aim of this review was to systematically review the efficacy of STN-DBS programming techniques in alleviating gait disturbances in patients with advanced PD. Searches were conducted in PubMed, Embase, and Lilacs databases, covering studies published until May 2024. The review identified 36 articles that explored five distinct STN-DBS techniques aimed at addressing gait and postural instability in Parkinson's patients: low-frequency stimulation, ventral STN stimulation for simultaneous substantia nigra activation, interleaving, asymmetric stimulation and a short pulse width study. Among these, 21 articles were included in the meta-analysis, which revealed significant heterogeneity among studies. Notably, low-frequency STN-DBS demonstrated positive outcomes in total UPDRS-III score and FOG-Q, especially when combined with dopaminergic therapy. The most favorable results were found for low-frequency STN stimulation. The descriptive analysis suggests that unconventional stimulation approaches may be viable for gait problems in patients who do not respond to standard therapies.
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Estimulación Encefálica Profunda , Trastornos Neurológicos de la Marcha , Enfermedad de Parkinson , Núcleo Subtalámico , Humanos , Estimulación Encefálica Profunda/métodos , Trastornos Neurológicos de la Marcha/etiología , Trastornos Neurológicos de la Marcha/fisiopatología , Trastornos Neurológicos de la Marcha/terapia , Enfermedad de Parkinson/terapia , Enfermedad de Parkinson/complicaciones , Núcleo Subtalámico/fisiopatología , Resultado del TratamientoRESUMEN
Piaractus brachypomus (Pacú) is the main native fish species cultivated in Peru and holds great potential for growth in aquaculture from the Peruvian Amazon. Between October 2021 and January 2022 in two fish producing farms in the Amazon region of San Martín in Peru, P. brachypomus individuals were examined for parasite evaluation. A total of 6366 monogeneans were isolated from the gills of 30 fish, revealing a prevalence of 100%, with an abundance and mean intensity of 212 parasites per fish. Monogeneans were morphologically identified as Mymarothecium viatorum and Anacanthorus penilabiatus. The genetic divergence in the 28S rDNA gene found among A. penilabiatus sequences was 0.1% and among Anacanthorus spp. it ranged from 0.9% to 7.5%. The genetic divergence found among the M. viatorum sequences was 0.3%. These finding represents the first molecular data of M. viatorum and A. penilabiatus in Peru using the 28S rDNA gene of these monogeneans. The new sequences obtained will contribute to future studies on the phylogenetic relationships among dactylogyrids. However, further research with a broader range of host-parasite samples and additional genetic markers is needed to clarify these relationships and provide stronger support for the phylogenetic positions.
Asunto(s)
Acuicultura , Enfermedades de los Peces , Infecciones por Trematodos , Animales , Perú/epidemiología , Enfermedades de los Peces/parasitología , Enfermedades de los Peces/epidemiología , Infecciones por Trematodos/veterinaria , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/epidemiología , Branquias/parasitología , Filogenia , Trematodos/clasificación , Trematodos/genética , Trematodos/aislamiento & purificación , ARN Ribosómico 28S/genética , ARN Ribosómico 28S/análisis , Prevalencia , Explotaciones Pesqueras , ADN Ribosómico/análisis , ADN Ribosómico/genéticaRESUMEN
Mine-tailing dumps are one of the leading sources of environmental degradation, often with public health and ecological consequences. Due to the complex ecosystems generated, they are ideal sites for exploring the bacterial diversity of specially adapted microorganisms. We investigated the concentrations of trace metals in solid copper (Cu) mine tailings from the Ovejería Tailings Dam of the National Copper Corporation of Chile and used high-throughput sequencing techniques to determine the microbial community diversity of the tailings using 16S rRNA gene-based amplicon sequence analysis. The concentrations of the detected metals were highest in the following order: iron (Fe) > Cu > manganese (Mn) > molybdenum (Mo) > lead (Pb) > chromium (Cr) > cadmium (Cd). Furthermore, 16S rRNA gene-based sequence analysis identified 12 phyla, 18 classes, 43 orders, 82 families, and 154 genera at the three sampling points. The phylum Proteobacteria was the most dominant, followed by Chlamydiota, Bacteroidetes, Actinobacteria, and Firmicutes. Genera, such as Bradyrhizobium, Aquabacterium, Paracoccus, Caulobacter, Azospira, and Neochlamydia, showed high relative abundance. These genera are known to possess adaptation mechanisms in high concentrations of metals, such as Cd, Cu, and Pb, along with nitrogen-fixation capacity. In addition to their tolerance to various metals, some of these genera may represent pathogens of amoeba or humans, which contributes to the complexity and resilience of bacterial communities in the studied Cu mining tailings. This study highlights the unique microbial diversity in the Ovejería Tailings Dam, including the discovery of the genus Neochlamydia, reported for the first time for heavy metal resistance. This underscores the importance of characterizing mining sites, particularly in Chile, to uncover novel bacterial mechanisms for potential biotechnological applications.
RESUMEN
Globally, coral reef ecosystems are undergoing significant change related to climate change and anthropogenic activities. Yet, the Cuban archipelago of Jardines de la Reina (JR) has experienced fewer stressors due to its geographical remoteness and high level of conservation. This study examines the surface and benthic reef water microbial communities associated with 32 reef sites along the JR archipelago and explores the relationship between the community composition of reef microorganisms examined using bacterial and archaeal small subunit ribosomal RNA gene (16S rRNA gene) sequencing compared to geographic, conservation/protection level, environmental, physicochemical, and reef benthic and pelagic community features. Reef nutrient concentrations were low and microbial communities dominated by picocyanobacteria and SAR11 and SAR86 clade bacteria, characteristic of an oligotrophic system. Reef water microbial community alpha and beta diversity both varied throughout the archipelago and were strongly related to geography. Three sites in the western archipelago showed unique microbial communities, which may be related to the hydrogeography and influences of the channels linking the Ana Maria gulf with the Caribbean Sea. Overall, this work provides the first extensive description of the reef microbial ecology of the Caribbean's 'Crown Jewel' reef system and a framework to evaluate the influence of ongoing stressors on the reef microorganisms.