El papel de los cannabinoides en los trastornos del neurodesarrollo de niños y adolescentes / The role of cannabinoids in neurodevelopmental disorders of children and adolescents

Introducción: Los trastornos del neurodesarrollo tienen una etiología multifactorial que resulta de la interacción entre factores biológicos y ambientales. La base biológica de muchos de estos trastornos se comprende sólo parcialmente, lo que hace que las intervenciones terapéuticas, especialmente las farmacológicas, sean particularmente difíciles. El impacto del cannabis medicinal en los trastornos neurológicos y psiquiátricos se ha estudiado durante mucho tiempo. Este estudio tuvo como objetivo revisar los estudios clínicos y preclínicos actualmente disponibles con respecto al uso de cannabinoides en trastornos del neurodesarrollo pediátrico y llamar la atención sobre el posible papel terapéutico del cannabidiol en este campo. Desarrollo: El cannabidiol es un modulador del sistema endocannabinoide y ejerce sus efectos tanto en cerebros en desarrollo como en cerebros maduros a través de numerosos mecanismos. El cannabidiol tiene un límite de toxicidad relativamente alto, y la bibliografía actual sugiere que puede tener propiedades ansiolíticas, antipsicóticas y neuroprotectoras. La evidencia clínica sugiere que el tratamiento temprano con cannabidiol podría ser una terapia prometedora para los trastornos del desarrollo neurológico, incluida la discapacidad intelectual, los trastornos del espectro autista, los tics y el trastorno por déficit de atención/hiperactividad. Conclusiones: Es de esperar que esta revisión llame la atención sobre un cuerpo emergente de evidencia sobre el potencial significativo del cannabidiol para mejorar de manera segura muchos de los síntomas comunes que afectan a niños y adolescentes con trastornos del neurodesarrollo, especialmente el trastorno del espectro autista.(AU)

INTRODUCTION: Neurodevelopmental disorders have a multifactorial etiology that results from the interaction between biological and environmental factors. The biological basis of many of these disorders is only partially understood, which makes therapeutic interventions, especially pharmacological ones, particularly difficult. The impact of medical cannabis on neurological and psychiatric disorders has been studied for a long time. This study aimed to review the currently available clinical and pre-clinical studies regarding the use of cannabinoids in pediatric neurodevelopmental disorders and to draw attention to the potential therapeutic role of cannabidiol in this field. DEVELOPMENT: Cannabidiol is an endocannabinoid system modulator and exerts its effects on both developing and mature brains through numerous mechanisms. Cannabidiol holds a relatively high toxicity limit and current literature suggests that it may have anxiolytic, antipsychotic, and neuroprotective properties. Clinical evidence suggests that early treatment with cannabidiol might be a promising therapy for neurodevelopmental disorders, including intellectual disability, autism spectrum disorders, tics, and attention/deficit hyperactivity disorder. CONCLUSIONS: This review hopefully draws attention to an emerging body of evidence concerning cannabidiol’s significant potential to safely improve many of the common symptoms affecting children and adolescents with neurodevelopmental disorders, especially autism spectrum disorder.(AU)

The role of cannabinoids in neurodevelopmental disorders of children and adolescents. / El papel de los cannabinoides en los trastornos del neurodesarrollo de niños y adolescentes.

INTRODUCTION: Neurodevelopmental disorders have a multifactorial etiology that results from the interaction between biological and environmental factors. The biological basis of many of these disorders is only partially understood, which makes therapeutic interventions, especially pharmacological ones, particularly difficult. The impact of medical cannabis on neurological and psychiatric disorders has been studied for a long time. This study aimed to review the currently available clinical and pre-clinical studies regarding the use of cannabinoids in pediatric neurodevelopmental disorders and to draw attention to the potential therapeutic role of cannabidiol in this field. DEVELOPMENT: Cannabidiol is an endocannabinoid system modulator and exerts its effects on both developing and mature brains through numerous mechanisms. Cannabidiol holds a relatively high toxicity limit and current literature suggests that it may have anxiolytic, antipsychotic, and neuroprotective properties. Clinical evidence suggests that early treatment with cannabidiol might be a promising therapy for neurodevelopmental disorders, including intellectual disability, autism spectrum disorders, tics, and attention/deficit hyperactivity disorder. CONCLUSIONS: This review hopefully draws attention to an emerging body of evidence concerning cannabidiol's significant potential to safely improve many of the common symptoms affecting children and adolescents with neurodevelopmental disorders, especially autism spectrum disorder.

TITLE: El papel de los cannabinoides en los trastornos del neurodesarrollo de niños y adolescentes.Introducción. Los trastornos del neurodesarrollo tienen una etiología multifactorial que resulta de la interacción entre factores biológicos y ambientales. La base biológica de muchos de estos trastornos se comprende sólo parcialmente, lo que hace que las intervenciones terapéuticas, especialmente las farmacológicas, sean particularmente difíciles. El impacto del cannabis medicinal en los trastornos neurológicos y psiquiátricos se ha estudiado durante mucho tiempo. Este estudio tuvo como objetivo revisar los estudios clínicos y preclínicos actualmente disponibles con respecto al uso de cannabinoides en trastornos del neurodesarrollo pediátrico y llamar la atención sobre el posible papel terapéutico del cannabidiol en este campo. Desarrollo. El cannabidiol es un modulador del sistema endocannabinoide y ejerce sus efectos tanto en cerebros en desarrollo como en cerebros maduros a través de numerosos mecanismos. El cannabidiol tiene un límite de toxicidad relativamente alto, y la bibliografía actual sugiere que puede tener propiedades ansiolíticas, antipsicóticas y neuroprotectoras. La evidencia clínica sugiere que el tratamiento temprano con cannabidiol podría ser una terapia prometedora para los trastornos del desarrollo neurológico, incluida la discapacidad intelectual, los trastornos del espectro autista, los tics y el trastorno por déficit de atención/hiperactividad. Conclusiones. Es de esperar que esta revisión llame la atención sobre un cuerpo emergente de evidencia sobre el potencial significativo del cannabidiol para mejorar de manera segura muchos de los síntomas comunes que afectan a niños y adolescentes con trastornos del neurodesarrollo, especialmente el trastorno del espectro autista.

Validation of a Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire.

BACKGROUND: The aim of this study was to validate and determine at pretest level the reliability of the Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire. MATERIAL AND METHODS: This study employed 37 head and neck cancer patients. Each patient signed an informed consent and responded to the Portuguese version of the questionnaire in the form of an interview. This was repeated again after 2 weeks. A standard single question provided a validity check. Data were analyzed using Cronbach's α to test its reliability and total and interitem correlation, and intraclass correlation to determine its internal consistency and test-retest reliability. Construct validity supported by objective measurements as salivary secretion was also investigated. Significance was set at .05. RESULTS: Cronbach's α was 0.91 and 0.89 for the first and second test administrations, respectively, which indicates that the internal consistency was excellent. The intraclass correlation coefficient value for the test-retest reliability was 0.70. The correlation between the total score of the questionnaire and standard single dry mouth question was 0.72 for the first round, indicating a good correlation. CONCLUSIONS: Demonstrating very good psychometric properties, the Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire is a valid tool and can be considered a reliable instrument to measure xerostomia in head and neck cancer patients.

Antifungal activity of linalool against fluconazole-resistant clinical strains of vulvovaginal Candida albicans and its predictive mechanism of action.

Candida albicans is the most frequently isolated opportunistic pathogen in the female genital tract, with 92.3% of cases in Brazil associated with vulvovaginal candidiasis (VVC). Linalool is a monoterpene compound from plants of the genera Cinnamomum, Coriandrum, Lavandula, and Citrus that has demonstrated a fungicidal effect on strains of Candida spp., but its mechanism of action is still unknown. For this purpose, broth microdilution techniques were applied, as well as molecular docking in a predictive manner for this mechanism. The main results of this study indicated that the C. albicans strains analyzed were resistant to fluconazole and sensitive to linalool at a dose of 256 µg/mL. Furthermore, the increase in the minimum inhibitory concentration (MIC) of linalool in the presence of sorbitol and ergosterol indicated that this molecule possibly affects the cell wall and plasma membrane integrity of C. albicans. Molecular docking of linalool with proteins that are key in the biosynthesis and maintenance of the cell wall and the fungal plasma membrane integrity demonstrated the possibility of linalool interacting with three important enzymes: 1,3-ß-glucan synthase, lanosterol 14α-demethylase, and Δ 14-sterol reductase. In silico analysis showed that this monoterpene has theoretical but significant oral bioavailability, low toxic potential, and high similarity to pharmaceuticals. Therefore, the findings of this study indicated that linalool probably causes damage to the cell wall and plasma membrane of C. albicans, possibly by interaction with important enzymes involved in the biosynthesis of these fungal structures, in addition to presenting low in silico toxic potential.

Antifungal activity of linalool against fluconazole-resistant clinical strains of vulvovaginal Candida albicans and its predictive mechanism of action

Candida albicans is the most frequently isolated opportunistic pathogen in the female genital tract, with 92.3% of cases in Brazil associated with vulvovaginal candidiasis (VVC). Linalool is a monoterpene compound from plants of the genera Cinnamomum, Coriandrum, Lavandula, and Citrus that has demonstrated a fungicidal effect on strains of Candida spp., but its mechanism of action is still unknown. For this purpose, broth microdilution techniques were applied, as well as molecular docking in a predictive manner for this mechanism. The main results of this study indicated that the C. albicans strains analyzed were resistant to fluconazole and sensitive to linalool at a dose of 256 µg/mL. Furthermore, the increase in the minimum inhibitory concentration (MIC) of linalool in the presence of sorbitol and ergosterol indicated that this molecule possibly affects the cell wall and plasma membrane integrity of C. albicans. Molecular docking of linalool with proteins that are key in the biosynthesis and maintenance of the cell wall and the fungal plasma membrane integrity demonstrated the possibility of linalool interacting with three important enzymes: 1,3-β-glucan synthase, lanosterol 14α-demethylase, and Δ 14-sterol reductase. In silico analysis showed that this monoterpene has theoretical but significant oral bioavailability, low toxic potential, and high similarity to pharmaceuticals. Therefore, the findings of this study indicated that linalool probably causes damage to the cell wall and plasma membrane of C. albicans, possibly by interaction with important enzymes involved in the biosynthesis of these fungal structures, in addition to presenting low in silico toxic potential.

miRNA-34 and miRNA-210 target hexamerin genes enhancing their differential expression during early brain development of honeybee (Apis mellifera) castes.

During the honeybee larval stage, queens develop larger brains than workers, with morphological differentiation appearing at the fourth larval phase (L4), just after a boost in nutritional difference both prospective females experience. The molecular promoters of this caste-specific brain development are already ongoing in previous larval phases. Transcriptomic analyses revealed a set of differentially expressed genes in the L3 brains of queens and workers, which represents the early molecular response to differential feeding females receive during larval development. Three genes of this set, hex70b, hex70c and hex110, are more highly transcribed in the brain of workers than in queens. The microRNAs miR-34, miR-210 and miR-317 are in higher levels in the queens' brain at the same phase of larval development. Here, we tested the hypothesis that the brain of workers expresses higher levels of hexamerins than that of queens during key phases of larval development and that this differential hexamerin genes expression is further enhanced by the repressing activity of miR-34, miR-210 and miR-317. Our transcriptional analyses showed that hex70b, hex70c and hex110 genes are differentially expressed in the brain of L3 and L4 larval phases of honeybee queens and workers. In silico reconstructed miRNA-mRNA interaction networks were validated using luciferase assays, which showed miR-34 and miR-210 negatively regulate hex70b and hex110 genes by directly and redundantly binding their 3'UTR (untranslated region) sequences. Taken together, our results suggest that miR-34 and miR-210 act together promoting differential brain development in honeybee castes by downregulating the expression of the putative antineurogenic hexamerin genes hex70b and hex110.

Copper molybdate synthesized by sonochemistry route at room temperature as an efficient solid catalyst for esterification of oleic acid.

Copper molybdate nanoplates were synthesized by a sonochemical process at room temperature, which we report as a simple and cost-effective route. Structural analysis of the material by the Rietveld method of X-ray diffraction (XRD) data revealed lindgrenite Cu3(MoO4)2(OH)2 in a single-phase structure. All the vibrational modes characteristic of the space group were identified by Raman vibrational and near-infrared (NIR) spectroscopies. The profile obtained for N2 adsorption/desorption was type III hysteresis, characteristic of mesoporous materials, with a surface area of 70.77(1) m2 g-1. The micrographs of the material obtained by scanning electron microscopy showed nanoplates with nanometric sizes and an anisotropic growth aspect. The catalytic activity of lindgrenite was evaluated by esterifying oleic acid with methanol, showing high conversion rate to methyl oleate and good catalyst stability after seven recycling cycles. Above all, the best catalytic performance was reached when we optimized parameters such as oleic acid:methanol molar ratio of 1:5, 5% of catalyst dosage, and reaction time of 5 h, resulting in 98.38% of conversion at 413 K. Therefore, sonochemically synthesized lindgrenite proved to be a high potential material for biofuel production by oleic acid esterification.

Genotypical characterization of thermotolerant coliforms isolated from food produced by a Solidarity Economic Venture of Bahia (Brazil) / Caracterização genotípica de coliformes termotolerantes isolados de alimentos produzidos por um Empreendimento Econômico Solidário

Abstract Many Solidarity Economic Venture (SEV) are family farmers who seek to add value to production through artisanal processing, which can lead to food contamination. Thus, this study aimed to genotypically characterize thermotolerant coliforms (TtC) strains from food produced by local agribusinesses of SEV during January to April 2019. Samples from thirteen production units (PU) from the SEV were submitted to a microbiological analysis of thermotolerant coliforms (AFNOR 3M1/2 - 09/89), using a fast count method in Petrifilm™ dishes. The Polymerase Chain Reaction (PCR) technique was used to verify the following virulence genes (VGs) associated with Escherichia coli: stx, typical from enterohemorrhagic E. coli (EHEC); bfpA typical from entheropathogenic E. coli (EPEC) and elt and slt, typical from entherotoxigenic E. coli (ETEC). The results showed that two samples of queijadinha (typical Brazilian candy made with eggs and coconut) and one sample of cassava cake presented characteristic colonies TtC. This way, three strains were isolated in order to perform the PCR technique. However, the genes used in the reaction were not detected in the isolated strains. Therefore, it is suggested that the isolated strains are from E. coli pathotypes with different virulence genes than the ones analyzed belong other types of TtC, such as Enterobacter and Klebsiella. Although the virulence of genes has not been confirmed, the presence of TtC on food indicates hygiene flaws during production and, therefore, measurements to control and prevent contamination should be taken.

Resumo Muitos Empreendimentos Econômicos Solidários (EES) são formados por agricultores familiares que buscam agregar valor à produção por meio do beneficiamento artesanal, que pode ocasionar a contaminação dos alimentos. Desta forma, este estudo objetivou caracterizar genotipicamente coliformes termotolerantes (CT) isolados em alimentos produzidos por agroindústrias de um EES no período de janeiro a abril de 2019. Então, foi realizada análise microbiológica de coliformes termotolerantes (AFNOR 3M1/2 - 09/89), utilizando um método contagem de contagem rápida em placas Petrifilm™, em amostras de alimentos de treze Unidades de Produção (UP) do EES. Foram coletadas assepticamente cinco amostras de cada UP, totalizando 65 amostras. Utilizou-se a técnica de Reação em Cadeia de Polimerase (PCR) para verificação dos seguintes genes de virulência de Escherichia coli: stx, característico de E. coli enterohemorrágica (EHEC), bfpA, característico de E. coli enteropatogênica (EPEC) e elt e stI, característicos de E. coli enterotoxigênica (ETEC). Os resultados demonstraram que duas amostras de queijadinha e uma amostra do bolo de aipim apresentaram colônias características de coliformes termotolerantes. Desta forma, foram isoladas três cepas para a realização da PCR, no entanto os genes utilizados nas reações não foram identificados nas cepas isoladas. Portanto, sugere-se que as cepas isoladas sejam de patótipos de E. coli com genes de virulência diferentes dos analisados ou de outro membro dos CT, como Enterobacter e Klebsiella. Apesar de não serem confirmados os genes de virulência analisados, a detecção dos CT nos alimentos indica falhas na higiene durante a produção, portanto medidas para controlar e prevenir a contaminação dos produtos devem ser tomadas.

Genotypical characterization of thermotolerant coliforms isolated from food produced by a Solidarity Economic Venture of Bahia (Brazil).

Many Solidarity Economic Venture (SEV) are family farmers who seek to add value to production through artisanal processing, which can lead to food contamination. Thus, this study aimed to genotypically characterize thermotolerant coliforms (TtC) strains from food produced by local agribusinesses of SEV during January to April 2019. Samples from thirteen production units (PU) from the SEV were submitted to a microbiological analysis of thermotolerant coliforms (AFNOR 3M1/2 - 09/89), using a fast count method in Petrifilm™ dishes. The Polymerase Chain Reaction (PCR) technique was used to verify the following virulence genes (VGs) associated with Escherichia coli: stx, typical from enterohemorrhagic E. coli (EHEC); bfpA typical from entheropathogenic E. coli (EPEC) and elt and slt, typical from entherotoxigenic E. coli (ETEC). The results showed that two samples of queijadinha (typical Brazilian candy made with eggs and coconut) and one sample of cassava cake presented characteristic colonies TtC. This way, three strains were isolated in order to perform the PCR technique. However, the genes used in the reaction were not detected in the isolated strains. Therefore, it is suggested that the isolated strains are from E. coli pathotypes with different virulence genes than the ones analyzed belong other types of TtC, such as Enterobacter and Klebsiella. Although the virulence of genes has not been confirmed, the presence of TtC on food indicates hygiene flaws during production and, therefore, measurements to control and prevent contamination should be taken.

Genetic associations between visual scores, body weight and age at first calving in nellore breed cattle / Associações genéticas entre escores visuais, peso corporal e idade ao primeiro parto de bovinos da raça Nelore

Body weight records of 231,416 Nellore females obtained from the Brazilian Association of Zebu Breeders were used to determine a linear combination between visual appraisal scores (body structure, precocity and muscling) using principal components analysis (PC), and to verify their genetic association with body weight at 12 months (BW) and age at first calving (AFC). The mixed linear model included the fixed effect of the contemporary group and the linear and quadratic effects of age at calving, random effects of genetic additive, maternal environment and temporary environment. Heritability estimates for BW, PC and AFC were 0.51, 0.30 and 0.17, respectively. Genetic additive correlations between BW and PC; BW and AFC, and PC and AFC were 0.48; -0.31 and -0.55; respectively. Spearman's correlations for the best-ranked bulls based on PC prediction were positive between BW and PC and negative among the other combinations. Heritability estimates and correlations indicate potential genetic gains for BW and CP with reduced AFC in cows. The use of PC allows positive responses on precocity and body weight development.(AU)

Utilizaram-se registros de pesos corporais de 231.416 fêmeas bovinas da raça Nelore, oriundos dos registros da Associação Brasileira de Criadores de Zebu-ABCZ, com o objetivo de estabelecer, por componentes principais, uma combinação linear (CP) das características de escores visuais de estrutura (E), precocidade (P) e musculosidade (M), bem como verificar sua associação genética com o peso corporal aos 12 meses (PC) e à idade ao primeiro parto (IPP). O modelo linear misto utilizado incluiu os efeitos fixos de grupo de contemporâneos e os efeitos linear e quadrático da idade da vaca ao parto, os efeitos aleatórios genético aditivo, ambiente materno e ambiente temporário. Estimativas de herdabilidade para PC, CP e IPP foram iguais a 0,51; 0,30 e 0,17, respectivamente. Correlações genéticas aditivas entre PC e CP; PC e IPP; e, ainda, CP e IPP foram iguais a 0,48; -0,31 e -0,55, respectivamente. As correlações de Spearman para os melhores reprodutores classificados em relação à predição de CP foram positivas entre PC e CP e negativas entre as demais combinações. Estimativas de herdabilidade e de correlações indicam possibilidade de ganhos genéticos expressivos para PC e CP com redução para IPP nas fêmeas. A utilização de CP possibilita respostas favoráveis para precocidade sexual e desenvolvimento ponderal.(AU)

Marine collagen scaffolds and photobiomodulation on bone healing process in a model of calvaria defects.

INTRODUCTION: Collagen from marine esponges has been used as a promising material for tissue engineering proposals. Similarly, photobiomodulation (PBM) is able of modulating inflammatory processes after an injury, accelerating soft and hard tissue healing and stimulating neoangiogenesis. However, the effects of the associated treatments on bone tissue healing have not been studied yet. In this context, the present study aimed to evaluate the biological temporal modifications (using two experimental periods) of marine sponge collagen or sponging (SPG) based scaffold and PBM on newly formed bone using a calvaria bone defect model. MATERIAL AND METHODS: Wistar rats were distributed into two groups: SPG or SPG/PBM and euthanized into two different experimental periods (15 and 45 days post-surgery). A cranial critical bone defect was used to evaluate the effects of the treatments. Histology, histomorfometry and immunohistological analysis were performed. RESULTS: Histological findings demonstrated that SPG/PBM-treated animals, 45 days post-surgery, demonstrated a higher amount of connective and newly formed bone tissue at the region of the defect compared to CG. Notwithstanding, no difference among groups were observed in the histomorphometry. Interestingly, for both anti-transforming growth factor-beta (TGF-ß) and anti-vascular endothelial growth factor (VEGF) immunostaining, higher values for SPG/PBM, at 45 days post-surgery could be observed. CONCLUSION: It can be concluded that the associated treatment can be considered as a promising therapeutical intervention.

Late-onset sepsis and mortality among neonates in a Brazilian Intensive Care Unit: a cohort study and survival analysis.

A cohort study was performed from January 2014 to December 2016 in a Brazilian neonatal intensive care unit, including neonates with high risk for infection and death. We estimated bloodstream infection (BSI) incidence and conducted a survival analysis, considering the time to death and to the first episode of BSI as outcomes, comparing very low birth weight (VLBW) neonates with the remaining neonates. An extended Cox model was performed and the hazard ratio (HR) was calculated for different time periods. The study had 1560 neonates included, the incidence and the incidence density of BSI was 22% and 18.6 per 1000 central venous catheter-days, respectively. Considering VLBW neonates as the reference group, the HR for time to death was 4.06 (95% CI 2.75-6.00, P < 0.01) from day 0 to 60 and for time to the first episode of BSI was 1.76 (95% CI 1.31-2.36, P < 0.01) from day 0 to 36. Having the heavier neonates group as reference, the HR for time to the first episode of BSI was 2.94 (95% CI 1.92-4.34, P < 0.01) from day 37 to 90. Late-onset neonatal sepsis prevention measures should consider the differences in risk during time, according to neonates' birth weight.

Dynamics of clonal and plasmid backgrounds of Enterobacteriaceae producing acquired AmpC in Portuguese clinical settings over time.

OBJECTIVES: The objective of this work was to provide detailed molecular data on clinically acquired AmpC (qAmpC)-producing Enterobacteriaceae from two different periods (2002-2008 and 2010-2013) in order to clarify the contribution of clonal and plasmid genetic platforms for the current epidemiological scenario concerning extended-spectrum beta-lactams resistance. METHODS: We analysed 1246 Enterobacteriaceae non-susceptible to third-generation cephalosporins from two hospitals and one community laboratory between 2010 and 2013. Bacterial identification, antibiotic susceptibility, identification of qAmpC and plasmid-mediated quinolone resistance genes, clonal (pulsed-field gel electrophoresis (PFGE), Multilocus sequence typing (MLST)) and plasmid (S1-/I-CeuI-PFGE, replicon typing, hybridization) analysis were performed by standard methods. Whole-genome sequencing (WGS) was performed in two ST11-Klebsiella pneumoniae isolates harbouring DHA-1. RESULTS: The occurrence of qAmpC was lower (2.6%) than that observed in a previous survey (7.4%), and varied slightly over time. Isolates produced DHA-1 (53%), CMY-2 (44%) or DHA-6 (3%), but significant epidemiological changes were observed in the two surveys. While DHA-1 persisted in different institutions by selection of a worldwide epidemic IncR plasmid in an ST11 harbouring KL105, CMY-2 rates increased over time linked to IncI1 plasmids (instead of IncK or IncA/C2) in multiple Escherichia coli clones. CONCLUSIONS: The higher frequency of DHA-1 qAmpC in these species contrasts with the scenario in most European countries. Furthermore, the different genetic backgrounds associated with either extended-spectrum ß-lactamases (ESBLs) or acquired AmpC ß-lactamases (qAmpC) in our country might have contributed to their differential expansion.

Photochemistry and desorption induced by X-rays in water rich astrophysical ice analogs: implications for the moon Enceladus and other frozen space environments.

Soft X-rays are an important agent for chemical processing in the Solar System and in the interstellar medium. The photolysis and photodesorption processes of H2O-rich ices triggered by soft X-rays was, experimentally, addressed in this paper. The experiments were performed at the Brazilian synchrotron facility LNLS/CNPEN employing broadband radiation (from 6 to 2000 eV; mainly soft X-rays and a small fraction of VUV) in solid samples at temperatures of 20 and 80 K. The icy samples were monitored by infrared spectroscopy. We determined the effective destruction cross section (in the order 10-18 cm2) as well as the formation cross section for the new species produced after the irradiation. Among them, we list OCN-, CO, CO3, CH3OH, H2O2, HCOO-, NH4 +, HCONH2 and CH3HCO, mostly formed in the experiment at 80 K. The chemical equilibrium stage was characterized and molecular abundances were quantified. In addition, we discuss a methodology to estimate the amount of unknown species in the ice produced by photolysis. The samples reach chemical equilibrium at fluences around 2-3 × 1018 cm-2. Timescales for reaching chemical equilibrium in space environments illuminated by X-rays were given, as well as the desorption yields induced by X-rays. The astrophysical implication on the surface chemistry and desorption processes at the moon Enceladus are provided.

Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae) / Acumulação de cobre pela macrófita aquática Salvinia biloba Raddi (Salviniaceae)

Abstract Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu) accumulation by Salvinia biloba Raddi (Salviniaceae) in different metal concentrations (1, 3 and 5 µg mL-1), as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days). The highest accumulation values were observed in treatment with 5 µg mL-1, which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.

Resumo Macrófitas aquáticas apresentam propriedades e mecanismos úteis à remoção de substâncias presentes em solução, comumente, utilizadas em processos de fitorremediação de ambientes aquáticos. Este estudo avaliou o desempenho de acumulação de cobre (Cu) por Salvinia biloba Raddi (Salviniaceae) em diferentes concentrações do metal (1, 3 e 5 µg mL-1), além do tratamento controle, avaliados em intervalos de 0, 7 e 14 dias, sob condições laboratoriais, com controle de pH e luminosidade. Após o experimento a biomassa de S. biloba, foi lavada, seca em estufa, triturada e submetida ao processo de digestão, sendo, posteriormente, o teor de cobre acumulado determinado por espectroscopia de absorção atômica. Os resultados evidenciaram que S. biloba é hábil em acumular cobre em sua biomassa, variando significativamente entre os diferentes tratamentos e dias de exposição ao contaminante, bem como por sua interação (tratamentos × dias). Os maiores teores de acúmulo foram observados no tratamento com 5 µg mL-1, que aos 14 dias apresentou até 11.861 µg g-1 de Cu. Observamos sintomas de toxicidade e mortalidade nas plantas, evidenciando, provavelmente, o efeito do cobre sobre a espécie quando em elevados níveis. Salvinia biloba é uma espécie eficiente na remoção do cobre em solução, sendo possível sua recomendação como agente de remediação em ecossistemas aquáticos.

Biosynthesis of silver nanoparticles and polyhydroxybutyrate nanocomposites of interest in antimicrobial applications.

This study deals with the optimization and scaling up of the production of poly(3-hydroxybutyrate), PHB, nanocomposites containing biosynthesized silver nanoparticles (AgNPs) to generate materials with antimicrobial performance. First, a comparative study of the chemical and biological synthesis of AgNPs during the fermentation process of Cupriavidus necator at shake flask-scale was carried out. These experiments demonstrated the inherent capacity of C. necator to reduce the silver salt and produce AgNPs without the need for adding a reducing agent and, that the method of synthesis (with or without reducing agent) affects the dispersion of the AgNPs and their antimicrobial performance. Finally, the process was scaled-up to a 10Liters bioreactor and the relevant physical properties of the PHB-AgNPs nanocomposites pressed into films were determined. From the characterization work, the AgNPs were found to be well dispersed and distributed into the polymer matrix, having a maximum frequency of particles with average diameter of 76-95nm. Moreover, the presence of AgNPs did not cause any effect on the thermal properties of the biopolymer, although a slight reduction in crystallinity was seen. The developed materials presented a strong antimicrobial activity against the food-borne pathogens Salmonella enterica and Listeria monocytogenes, which makes them potentially suitable for active coatings and packaging applications. Complete biodisintegration of the samples occurred during composting conditions within the first 40days. Interestingly, the presence of the AgNPs did not impair the profile of biodegradation of the microbial polymer.

Characterization and Comparison of Genetic Variation in Cotesia flavipes (Hymenoptera: Braconidae) Mass Reared for Biological Pest Control Using Microsatellite Markers.

The larval parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) is an important biological control agent of the sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). This exotic parasitoid has been mass reared for field release since its introduction in the 1970s. Insects are exchanged between labs or introduced from the field, but without basic studies or criteria. Thus, the objective of this study was to evaluate the genetic variability of insects from six Brazilian States (São Paulo, Minas Gerais, Paraná, Goiás, Maranhão, and Alagoas) using microsatellites. Analysis of five loci using at least 22 females from each location was performed. The molecular analysis made possible to verify that four out of the five loci analyzed were polymorphic. The allele frequencies of three loci were in agreement with the Hardy-Weinberg Equilibrium for all insects of all regions. It was also observed that five alleles were exclusively presented in only two loci. The variation among and within populations was 24.65 and 75.34%, respectively. The estimated shared genotypes between the C. flavipes individuals showed that K = 2 was the most likely number of genetic groups causing the current variation, as well as high shared genotypes from these groups of the individuals. Considering all the analyzed loci, the genetic differentiation was at a moderate level. We suggest a possible mixture of biological materials based on genetic distances and the degree of structuring displayed.

Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae).

Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu) accumulation by Salvinia biloba Raddi (Salviniaceae) in different metal concentrations (1, 3 and 5 µg mL-1), as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days). The highest accumulation values were observed in treatment with 5 µg mL-1, which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.

Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae)

Abstract Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu) accumulation by Salvinia biloba Raddi (Salviniaceae) in different metal concentrations (1, 3 and 5 µg mL-1), as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days). The highest accumulation values were observed in treatment with 5 µg mL-1, which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.

Resumo Macrófitas aquáticas apresentam propriedades e mecanismos úteis à remoção de substâncias presentes em solução, comumente, utilizadas em processos de fitorremediação de ambientes aquáticos. Este estudo avaliou o desempenho de acumulação de cobre (Cu) por Salvinia biloba Raddi (Salviniaceae) em diferentes concentrações do metal (1, 3 e 5 µg mL-1), além do tratamento controle, avaliados em intervalos de 0, 7 e 14 dias, sob condições laboratoriais, com controle de pH e luminosidade. Após o experimento a biomassa de S. biloba, foi lavada, seca em estufa, triturada e submetida ao processo de digestão, sendo, posteriormente, o teor de cobre acumulado determinado por espectroscopia de absorção atômica. Os resultados evidenciaram que S. biloba é hábil em acumular cobre em sua biomassa, variando significativamente entre os diferentes tratamentos e dias de exposição ao contaminante, bem como por sua interação (tratamentos × dias). Os maiores teores de acúmulo foram observados no tratamento com 5 µg mL-1, que aos 14 dias apresentou até 11.861 µg g-1 de Cu. Observamos sintomas de toxicidade e mortalidade nas plantas, evidenciando, provavelmente, o efeito do cobre sobre a espécie quando em elevados níveis. Salvinia biloba é uma espécie eficiente na remoção do cobre em solução, sendo possível sua recomendação como agente de remediação em ecossistemas aquáticos.