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1.
Front Cell Infect Microbiol ; 14: 1297099, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38495650

RESUMO

Introduction: Oral transmission of T. cruzi is probably the most frequent transmission mechanism in wild animals. This observation led to the hypothesis that consuming raw or undercooked meat from animals infected with T. cruzi may be responsible for transmitting the infection. Therefore, the general objective of this study was to investigate host-pathogen interactions between the parasite and gastric mucosa and the role of meat consumption from infected animals in the oral transmission of T. cruzi. Methods: Cell infectivity assays were performed on AGS cells in the presence or absence of mucin, and the roles of pepsin and acidic pH were determined. Moreover, groups of five female Balb/c mice were fed with muscle tissue obtained from mice in the acute phase of infection by the clone H510 C8C3hvir of T. cruzi, and the infection of the fed mice was monitored by a parasitemia curve. Similarly, we assessed the infective capacity of T. cruzi trypomastigotes and amastigotes by infecting groups of five mice Balb/c females, which were infected orally using a nasogastric probe, and the infection was monitored by a parasitemia curve. Finally, different trypomastigote and amastigote inoculums were used to determine their infective capacities. Adhesion assays of T. cruzi proteins to AGS stomach cells were performed, and the adhered proteins were detected by western blotting using monoclonal or polyclonal antibodies and by LC-MS/MS and bioinformatics analysis. Results: Trypomastigote migration in the presence of mucin was reduced by approximately 30%, whereas in the presence of mucin and pepsin at pH 3.5, only a small proportion of parasites were able to migrate (∼6%). Similarly, the ability of TCTs to infect AGS cells in the presence of mucin is reduced by approximately 20%. In all cases, 60-100% of the animals were fed meat from mice infected in the acute phase or infected with trypomastigotes or amastigotes developed high parasitemia, and 80% died around day 40 post-infection. The adhesion assay showed that cruzipain is a molecule of trypomastigotes and amastigotes that binds to AGS cells. LC-MS/MS and bioinformatics analysis, also confirmed that transialidase, cysteine proteinases, and gp63 may be involved in TCTs attachment or invasion of human stomach cells because they can potentially interact with different proteins in the human stomach mucosa. In addition, several human gastric mucins have cysteine protease cleavage sites. Discussion: Then, under our experimental conditions, consuming meat from infected animals in the acute phase allows the T. cruzi infection. Similarly, trypomastigotes and amastigotes could infect mice when administered orally, whereas cysteinyl proteinases and trans-sialidase appear to be relevant molecules in this infective process.


Assuntos
Doença de Chagas , Doenças Transmissíveis , Trypanosoma cruzi , Feminino , Animais , Camundongos , Humanos , Trypanosoma cruzi/metabolismo , Pepsina A/metabolismo , Parasitemia , Modelos Animais de Doenças , Cromatografia Líquida , Espectrometria de Massas em Tandem , Doença de Chagas/parasitologia , Mucinas
2.
Sci Rep ; 14(1): 5000, 2024 02 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424216

RESUMO

Trypanosoma cruzi is the protozoan that causes Chagas disease (CD), an endemic parasitosis in Latin America distributed around the globe. If CD is not treated in acute phase, the parasite remains silent for years in the host's tissues in a chronic form, which may progress to cardiac, digestive or neurological manifestations. Recently, studies indicated that the gastrointestinal tract represents an important reservoir for T. cruzi in the chronic phase. During interaction T. cruzi and host cells release extracellular vesicles (EVs) that modulates the immune system and infection, but the dynamics of secretion of host and parasite molecules through these EVs is not understood. Now, we used two cell lines: mouse myoblast cell line C2C12, and human intestinal epithelial cell line Caco-2to simulate the environments found by the parasite in the host. We isolated large EVs (LEVs) from the interaction of T. cruzi CL Brener and Dm28c/C2C12 and Caco-2 cells upon 2 and 24 h of infection. Our data showed that at two hours there is a strong cellular response mediated by EVs, both in the number, variety and enrichment/targeting of proteins found in LEVs for diverse functions. Qualitative and quantitative analysis showed that proteins exported in LEVs of C2C12 and Caco-2 have different patterns. We found a predominance of host proteins at early infection. The parasite-host cell interaction induces a switch in the functionality of proteins carried by LEVs and a heterogeneous response depending on the tissues analyzed. Protein-protein interaction analysis showed that cytoplasmic and mitochondrial homologues of the same parasite protein, tryparedoxin peroxidase, were differentially packaged in LEVs, also impacting the interacting molecule of this protein in the host. These data provide new evidence that the interaction with T. cruzi leads to a rapid tissue response through the release of LEVs, reflecting the enrichment of some proteins that could modulate the infection environment.


Assuntos
Doença de Chagas , Vesículas Extracelulares , Trypanosoma cruzi , Animais , Camundongos , Humanos , Trypanosoma cruzi/metabolismo , Células CACO-2 , Doença de Chagas/parasitologia , Vesículas Extracelulares/metabolismo , Interações Hospedeiro-Parasita
3.
J Evol Biol ; 36(11): 1595-1608, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37885128

RESUMO

Hybridization could be considered part of the evolutionary history of many species. The hybridization among sea turtle species on the Brazilian coast is atypical and occurs where nesting areas and reproductive seasons overlap. Integrated analysis of morphology and genetics is still scarce, and there is no evidence of the parental chromosome set distribution in sea turtle interspecific hybrids. In this study, chromosome markers previously established for pure sea turtle species were combined with morphological and molecular analyses aiming to recognize genetic composition and chromosome sets in possible interspecific hybrids initially identified by mixed morphology. The data showed that one hybrid could be an F2 individual among Caretta caretta × Eretmochelys imbricata × Chelonia mydas, and another is resulting from backcross between C. caretta × Lepidochelys olivacea. Native alleles of different parental lineages were reported in the hybrids, and, despite this, it was verified that the hybrid chromosome sets were still balanced. Thus, how sea turtle hybridism can affect genetic features in the long term is a concern, as the implications of the crossing-over in hybrid chromosomal sets and the effects on genetic function are still unpredictable.


Assuntos
Tartarugas , Animais , Tartarugas/genética , Evolução Biológica , Reprodução , Cromossomos , Análise Citogenética
4.
PhytoKeys ; 232: 109-131, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37746324

RESUMO

Connective glands are important morphological characters for the taxonomy of some genera of Malpighiaceae, with few recent studies having just elucidated these glands' anatomical and ecological functions. In order to test the systematic relevance of connective glands to the currently accepted phylogenetic informal clades of Malpighiaceae, we characterised the anatomy and/or histochemistry of two-thirds of Malpighiaceae genera and ten species from nine families of Malpighiales to test: 1. Do connective glands occur in the flowers of all informal clades of Malpighiaceae?; and 2. Are they taxonomically relevant to characterise those clades? We sampled 25 genera and 26 species of Malpighiaceae, processing their anthers using traditional anatomical methods and characterising their glands using light microscopy and SEM imaging. Selected species were subjected to histochemical tests, and an additional 21 genera and 33 species of Malpighiaceae and nine families (ten species) of Malpighiales were included in our sampling from the literature. Three anatomical characters were scored, coded and mapped using Maximum Likelihood methods onto the molecular phylogeny of Malpighiaceae. All sampled species of Malpighiaceae showed connective glands characterised as epidermal or trichomal elaiophores. Our character-mapping analyses recovered connective elaiophores as a new synapomorphy for Malpighiaceae. Different types of epidermal or trichomal elaiophores were recovered as homoplasies for the Christianella and Banisteriopsis clades and the genera Byrsonima, Camarea and Cottsia. Our analyses also recovered the glands' place of insertion in the stamen and the exudate type as potential new synapomorphies or homoplasies for the families of Malpighiales sampled. Our results propose the connective elaiophores as a new synapomorphy for Malpighiaceae and hypothesise the role that different staminal glands might play in the systematics of Malpighiales. Further comprehensive anatomical studies are still needed for the staminal glands of most families of this order to shed new light on the patterns recovered in our study.

5.
Development ; 150(12)2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37309812

RESUMO

Targeted knock-in of fluorescent reporters enables powerful gene and protein analyses in a physiological context. However, precise integration of long sequences remains challenging in vivo. Here, we demonstrate cloning-free and precise reporter knock-in into zebrafish genes, using PCR-generated templates for homology-directed repair with short homology arms (PCR tagging). Our novel knock-in reporter lines of vesicle-associated membrane protein (vamp) zebrafish homologues reveal subcellular complexity in this protein family. Our approach enables fast and efficient reporter integration in the zebrafish genome (in 10-40% of injected embryos) and rapid generation of stable germline-transmitting lines.


Assuntos
Sistemas CRISPR-Cas , Peixe-Zebra , Animais , Sistemas CRISPR-Cas/genética , Peixe-Zebra/genética , Técnicas de Introdução de Genes , Genoma , Edição de Genes
6.
Proteomics ; 23(16): e2200230, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37183273

RESUMO

Post-translational methylation of proteins, which occurs in arginines and lysines, modulates several biological processes at different levels of cell signaling. Recently, methylation has been demonstrated in the regulation beyond histones, for example, in the dynamics of protein-protein and protein-nucleic acid interactions. However, the presence and role of non-histone methylation in Trypanosoma cruzi, the etiologic agent of Chagas disease, has not yet been elucidated. Here, we applied mass spectrometry-based-proteomics (LC-MS/MS) to profile the methylproteome of T. cruzi epimastigotes, describing a total of 1252 methyl sites in 824 proteins. Functional enrichment and protein-protein interaction analysis show that protein methylation impacts important biological processes of the parasite, such as translation, RNA and DNA binding, amino acid, and carbohydrate metabolism. In addition, 171 of the methylated proteins were previously reported to bear phosphorylation sites in T. cruzi, including flagellar proteins and RNA binding proteins, indicating that there may be an interplay between these different modifications in non-histone proteins. Our results show that a broad spectrum of functions is affected by methylation in T. cruzi, indicating its potential to impact important processes in the biology of the parasite and other trypanosomes.


Assuntos
Histonas , Trypanosoma cruzi , Histonas/metabolismo , Trypanosoma cruzi/química , Trypanosoma cruzi/genética , Metilação , Cromatografia Líquida , Espectrometria de Massas em Tandem , Proteínas de Protozoários/genética
7.
Biomark Insights ; 17: 11772719221131470, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36311208

RESUMO

Background: Systemic lupus erythematosus (SLE) is a chronic, multi phenotypic, autoimmune inflammatory disease and renal involvement significantly worsens its prognosis. Apoptosis dysregulation plays a key pathogenic role. Survivin, a protein from the apoptosis inhibitors family, has been considered a promising strategy in cancer therapy and evaluated as one of the regulatory pathways in the scenario of immune-mediated disorders. Objective: This study aims to explore survivin behaviour in SLE patients with lupus nephritis (LN), assessing its potential as a therapeutic and prognostic biomarker. Methods: 297 SLE patients were classified based on the American College of Rheumatology (ACR) 1997 criteria, from 2000 to 2015. In a cross-sectional study, the serum level of survivin was measured by an ELISA test and compared between 200 SLE individuals and healthy controls. In a longitudinal cohort, 97 patients with active LN had the concentration of survinin measured, before and after treatment with cyclophosphamide pulse therapy. Results: The serum concentration of survivin was significantly lower in the SLE group than in healthy controls, regardless of concomitant NL or disease activity. The longitudinal evaluation revealed a significant reduction in survivin serum level after treatment. However, survivin rates were not able to discriminate groups that achieved remission from those that maintained nephritis activity. Conclusion: Our study suggests that survivin levels in SLE patients are lower than in the general population. Even so, its use as a biomarker in SLE seems limited, not reflecting disease activity or response to LN treatment, as in other contexts.

8.
Front Plant Sci ; 13: 854842, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35498703

RESUMO

Natural products produced by plants are one of the most investigated natural sources, which substantially contributed to the development of the natural products field. Even though these compounds are widely explored, the literature still lacks comprehensive investigations aiming to explore the evolution of secondary metabolites produced by plants, especially if classical methodologies are employed. The development of sensitive hyphenated techniques and computational tools for data processing has enabled the study of large datasets, being valuable assets for chemosystematic studies. Here, we describe a strategy for chemotaxonomic investigations using the Malpighiaceae botanical family as a model. Our workflow was based on MS/MS untargeted metabolomics, spectral searches, and recently described in silico classification tools, which were mapped into the latest molecular phylogeny accepted for this family. The metabolomic analysis revealed that different ionization modes and extraction protocols significantly impacted the chemical profiles, influencing the chemotaxonomic results. Spectral searches within public databases revealed several clades or genera-specific molecular families, being potential chemical markers for these taxa, while the in silico classification tools were able to expand the Malpighiaceae chemical space. The classes putatively annotated were used for ancestral character reconstructions, which recovered several classes of metabolites as homoplasies (i.e., non-exclusive) or synapomorphies (i.e., exclusive) for all sampled clades and genera. Our workflow combines several approaches to perform a comprehensive evolutionary chemical study. We expect it to be used on further chemotaxonomic investigations to expand chemical knowledge and reveal biological insights for compounds classes in different biological groups.

9.
Int J Equity Health ; 20(1): 197, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34461895

RESUMO

BACKGROUND: Most estimates of visual impairment and blindness worldwide do not include data from specific minority groups as indigenous populations. We aimed to evaluate frequencies and causes of visual impairment and blindness in a large population sample from the Xingu Indigenous Park. METHODS: Cross-sectional study performed at Xingu Indigenous Park, Brazil, from 2016 to 2017. Residents from 16 selected villages were invited to participate and underwent a detailed ocular examination, including uncorrected (UVA) and best-corrected visual acuity (BCVA). The main cause of UVA < 20/32 per eye was determined. RESULTS: A total of 2,099 individuals were evaluated. Overall, the frequency of visual impairment and blindness was 10.00% (95% CI: 8.72-11.29%) when considering UVA, decreasing to 7.15% (95% CI: 6.04-8.25%) when considering BCVA. For each increasing year on age, the risk  of being in the visually impaired or blind category increased by 9% (p < 0.001). Cataracts (39.1%) and uncorrected refractive errors (29.1%) were the most frequent causes of visual impairment and blindness in this population. The main causes among those aged 45 years and more were cataracts (54.5%) while refractive errors were the main cause in adults aged 18 to 45 years (50.0%) and children up to 18 years old (37.1%). CONCLUSIONS: A higher frequency of visual impairment and blindness was observed in the indigenous population when compared to worldwide estimates with most of the causes being preventable and/or treatable. Blindness prevention programs should focus on accessibility to eye exam, cataract surgeries and eyeglass distribution.


Assuntos
Cegueira , Baixa Visão , Adolescente , Adulto , Cegueira/epidemiologia , Cegueira/etiologia , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Disparidades nos Níveis de Saúde , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Grupos Populacionais/estatística & dados numéricos , Prevalência , Baixa Visão/epidemiologia , Baixa Visão/etiologia , Adulto Jovem
10.
Sci Data ; 8(1): 93, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33767201

RESUMO

In humans and other eukaryotes, histone post-translational modifications (hPTMs) play an essential role in the epigenetic control of gene expression. In trypanosomatid parasites, conversely, gene regulation occurs mainly at the post-transcriptional level. However, our group has recently shown that hPTMs are abundant and varied in Trypanosoma cruzi, the etiological agent of Chagas Disease, signaling for possible conserved epigenetic functions. Here, we applied an optimized mass spectrometry-based proteomic workflow to provide a high-confidence comprehensive map of hPTMs, distributed in all canonical, variant and linker histones of T. cruzi. Our work expands the number of known T. cruzi hPTMs by almost 2-fold, representing the largest dataset of hPTMs available to any trypanosomatid to date, and can be used as a basis for functional studies on the dynamic regulation of chromatin by epigenetic mechanisms and the selection of candidates for the development of epigenetic drugs against trypanosomatids.


Assuntos
Doença de Chagas/metabolismo , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/metabolismo , Cromatina/metabolismo , Desenvolvimento de Medicamentos , Epigênese Genética , Humanos , Espectrometria de Massas/métodos , Proteômica/métodos , Proteínas de Protozoários/genética , Tripanossomicidas/química , Trypanosoma cruzi/genética
11.
J Nat Prod ; 83(11): 3239-3249, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33196207

RESUMO

Proper chromatographic methods may reduce the challenges inherent in analyzing natural product extracts, especially when utilizing hyphenated detection techniques involving mass spectrometry. As there are many variations one can introduce during chromatographic method development, this can become a daunting and time-consuming task. To reduce the number of runs and time needed, the use of instrumental automatization and commercial software to apply Quality by Design and statistical analysis automatically can be a valuable approach to investigate complex matrices. To evaluate this strategy in the natural products workflow, a mixture of nine species from the family Malpighiaceae was investigated. By this approach, the entire data collection and method development procedure (comprising screening, optimization, and robustness simulation) was accomplished in only 4 days, resulting in very low limits of detection and quantification. The analysis of the individual extracts also proved the efficiency of the use of a mixture of extracts for this workflow. Molecular networking and library searches were used to annotate a total of 61 compounds, including O-glycosylated flavonoids, C-glycosylated flavonoids, quinic/shikimic acid derivatives, sterols, and other phenols, which were efficiently separated by the method developed. These results support the potential of statistical tools for chromatographic method optimization as an efficient approach to reduce time and maximize resources, such as solvents, to get proper chromatographic conditions.


Assuntos
Produtos Biológicos/química , Malpighiaceae/química , Cromatografia Líquida de Alta Pressão/métodos , Limite de Detecção , Extratos Vegetais/química , Reprodutibilidade dos Testes , Especificidade da Espécie , Espectrometria de Massas em Tandem/métodos , Fluxo de Trabalho
12.
Plants (Basel) ; 9(11)2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33203045

RESUMO

We investigated the biogeography of Stigmaphyllon, the second-largest lianescent genus of Malpighiaceae, as a model genus to reconstruct the age and biogeographic history of the Brazilian Atlantic Rainforest (BAF). Few studies to date have focused on the tertiary diversification of plant lineages in the BAFs, especially on Stigmaphyllon. Phylogenetic relationships for 24 species of Stigmaphyllon (18 ssp. From the Atlantic forest (out of 31 spp.), three spp. from the Amazon Rainforest, two spp. from the Caatinga biome, and a single species from the Cerrado biome) were inferred based on one nuclear DNA (PHYC) and two ribosomal DNA (ETS, ITS) regions using parsimony and Bayesian methods. A time-calibrated phylogenetic tree for ancestral area reconstructions was additionally generated, coupled with a meta-analysis of vascular plant lineages diversified in the BAFs. Our results show that: (1) Stigmaphyllon is monophyletic, but its subgenera are paraphyletic; (2) the most recent common ancestor of Stigmaphyllon originated in the Brazilian Atlantic Rainforest/Caatinga region in Northeastern Brazil ca. 26.0 Mya; (3) the genus colonized the Amazon Rainforest at two different times (ca. 22.0 and 6.0 Mya), the Caatinga biome at least four other times (ca. 14.0, 9.0, 7.0, and 1.0 Mya), the Cerrado biome a single time (ca. 15.0 Mya), and the Southern Atlantic Rainforests five times (from 26.0 to 9.0 Mya); (4) a history of at least seven expansion events connecting the Brazilian Atlantic Rainforest to other biomes from 26.0 to 9.0 Mya, and (5) a single dispersion event from South America to Southeastern Asia and Oceania at 22.0 Mya via Antarctica was proposed. Compared to a meta-analysis of time-calibrated phylogenies for 64 lineages of vascular plants diversified in the Brazilian Atlantic Rainforests, our results point to a late Eocene origin for this megadiverse biome.

13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 406-409, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018014

RESUMO

Catheter ablation is increasingly used to treat atrial fibrillation (AF), the most common sustained cardiac arrhythmia encountered in clinical practice. A recent breakthrough finding in AF ablation consists in identifying ablation sites based on their spatiotemporal dispersion (STD). STD stands for a delay of the cardiac activation observed in intracardiac electrograms (EGMs) across contiguous leads. In practice, interventional cardiologists localize STD sites visually using the PentaRay multipolar mapping catheter. This work aims at automatically characterizing STD by classifying EGM data into STD vs. non STD groups using machine learning (ML) techniques. A dataset of 23082 multichannel EGM recordings acquired by the PentaRay coming from 16 persistent AF patients is included in this study. A major problem hampering the classification performance lies in the highly imbalanced dataset ratio. We suggest to tackle data imbalance using adapted data augmentation techniques including 1) undersampling 2) oversampling 3) lead shift 4) time reversing and 5) time shift. These tools are designed to preserve the integrity of the cardiac data and are validated by a partner cardiologist. They provide enhancement in classification performance in terms of sensitivity, which increases from 50% to 80% while maintaining accuracy and AUC around 90% with oversampling. Bootstrapping is applied to check the variability of the trained classifiers.Clinical relevance-The machine learning techniques developed in this contribution are expected to aid cardiologists in performing patient-tailored catheter ablation procedures for treating persistent AF.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Fibrilação Atrial/cirurgia , Doença do Sistema de Condução Cardíaco , Técnicas Eletrofisiológicas Cardíacas , Humanos , Aprendizado de Máquina
14.
Clin Nephrol ; 94(4): 187-196, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32691731

RESUMO

BACKGROUND: NPHS2 gene variants are associated with focal segmental glomerulosclerosis (FSGS) and steroid-resistant nephrotic syndrome (SRNS). In this study, the prevalence of NPHS2 variants p.R229Q, p.A242V, and p.R138Q was investigated in patients with familial or sporadic FSGS. MATERIALS AND METHODS: The sample consisted of 40 children and 70 adults diagnosed with FSGS confirmed by renal biopsy. Clinical and laboratory parameters were evaluated. Genotyping for the three single nucleotide polymorphisms (SNPs) was performed by real-time polymerase chain reaction: two variants in exon 5 (p.R229Q and p.A242V) and one in exon 3 (p.R138Q). Variants were correlated with ethnicity, clinical presentation, treatment response, and renal outcomes. RESULTS: Among the 40 children analyzed, 20% had familial and 80% sporadic FSGS and among adults, 4.3% had familial and 95.7% sporadic FSGS, respectively. Overall, SRNS was found in 70% of adults and 90% in children. Among children, variants were detected in 2 (5%) with sporadic FSGS, p.R229Q and p.A242V in 1 each. Among adults, variants were present in 9 (12.9%) patients, all with sporadic FSGS, p.R229Q in 4 and p.A242V in 5. No patient had the p.R138Q variant. Among adults, a trend of higher proteinuria at the end of follow-up (p = 0.06) was found in patients carrying a variant. There was no significant association between NPHS2 variants with the clinical presentation, dependence on immunosuppressive treatment, or renal outcomes. Regarding ethnicity, all patients carrying the p.R229Q variant were White, while 67% of carriers of the p.A242V variant were Black. CONCLUSION: In these patients with familial or sporadic FSGS, the prevalence of p.R229Q and p.A242V variants in children was 5% and in adults 12.9%. More studies of patients with FSGS could better define a strategy for genetic analysis and therapeutic management.


Assuntos
Glomerulosclerose Segmentar e Focal , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Adulto , Criança , Estudos Transversais , Glomerulosclerose Segmentar e Focal/epidemiologia , Glomerulosclerose Segmentar e Focal/genética , Humanos , Polimorfismo de Nucleotídeo Único/genética
15.
Chemphyschem ; 21(6): 476-483, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-31943643

RESUMO

Herein, a detailed investigation of the surface modification of a zinc oxide (ZnO) nanorod electrode with FeOOH nanoparticles dispersed in glycine was conducted to improve the water oxidation reaction assisted by sunlight. The results were systematically analysed in terms of the general parameters (light absorption, charge separation, and surface for catalysis) that govern the photocurrent density response of metal oxide as photoanode in a photoelectrochemical (PEC) cell. ZnO electrodes surface were modified with different concentration of FeOOH nanoparticles using the spin-coating deposition method, and it was found that 6-layer deposition of glycine-FeOOH nanoparticles is the optimum condition. The glycine plays an important role decreasing the agglomeration of FeOOH nanoparticles over the ZnO electrode surface and increasing the overall performance. Comparing bare ZnO electrodes with the ones modified with glycine-FeOOH nanoparticles an enhanced photocurrent density can be observed from 0.27 to 0.57 mA/cm2 at 1.23 VRHE under sunlight irradiation. The impedance spectroscopy data aid us to conclude that the higher photocurrent density is an effect associated with more efficient surface for chemical reaction instead of electronic improvement. Nevertheless, the charge separation efficiency remains low for this system. The present discovery shows that the combination of glycine-FeOOH nanoparticle is suitable and environmentally-friend cocatalyst to enhance the ZnO nanorod electrode activity for the oxygen evolution reaction assisted by sunlight irradiation.

16.
Sci Total Environ ; 687: 917-928, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31412495

RESUMO

Although high levels of dissolved arsenic were detected in surface and ground waters of Nhecolândia, a sub-region of the vast Pantanal wetlands in Brazil, the possible sources have not been clearly identified and the potential release from the wetland to the draining rivers has not been investigated. In this study we measured the dissolved As content in all the rivers and small streams that supply the southern Pantanal region, as well as in the two main rivers draining the wetland, i.e., the Cuiaba and Paraguay rivers and tributaries. In addition, Arsenic in surface waters, perched water-table, soils and sediments from 3 experimental sites located in the heart of Nhecolândia were compared. On the one hand, the results show the absence of As contamination in rivers that supply the Pantanal floodplain, as well as a lack of significant release from the floodplain to the main drains. The As contents in the rivers are <2 µg L-1, with variations that depend on the lithology and on the geomorphology at the collection point (uplands or floodplain). On the other hand, they confirm the regional extension of As contamination in Nhecolândia's alkaline waters with some values above 3 mg L-1. Arsenic is mainly in the arsenate form, and increases with the evaporation process estimated from sodium ion concentrations. The pH of soil solution and surface water increases rapidly during evapo-concentration up to values above 9 or 10, preventing adsorption processes on oxides and clay minerals and promoting the retention of dissolved arsenic in solution. Solutions from organic soil horizons show higher As contents in relation to Na, attributed to the formation of ternary complex As-(Fe/Al)-OM. In this alkaline pH range, despite high levels of dissolved As, soil horizons and lake sediments in contact with these waters show As values that correspond to uncontaminated environments.

17.
Anesth Prog ; 64(3): 153-161, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28858549

RESUMO

Surgical treatment of panfacial fractures usually requires intraoperative temporary occlusion of the teeth and simultaneous access to the nasal pyramid. In such cases, the standard method of airway management is to perform a tracheostomy, but this may be associated with a significant number of perioperative and late complications. This study aimed to determine if submental endotracheal intubation (SEI) is a viable alternative to tracheostomy, especially when short-term postoperative control of the airway is foreseen. This was an observational retrospective study, carried out between 2012 and 2014, which involved 32 consecutive patients who sustained panfacial fractures and were surgically treated during a 3-year period in a level I trauma center hospital. Only those who required SEI were included in the sample. Four cases were excluded because of incomplete registries, follow-up period less than 4 months after hospital discharge, or other unrelated complications. The medical charts of all patients involved in the sample were carefully reviewed in order to qualify and quantify perioperative and postoperative complications related to anesthetic management. We hypothesized that SEI would not interfere with the surgical procedures and would present less morbidity and reduced complication rates. Twenty-eight patients, 24 male and 4 female, met all the inclusion criteria. The mean age was 29.5 ± 9.05 years (range, 18-56 years). The mean duration time of surgery was 8.07 ± 4.0 hours (range, 4-16 hours). There were no perioperative complications. Postoperatively, only 1 patient (3.57%) experienced a cutaneous infection at the submental region, which was easily treated. Additionally, only 1 case (3.57%) of hypertrophic scar was reported. SEI appears to be a safe, simple, and effective technique of immediate perioperative airway management in selected cases of panfacial fractures.


Assuntos
Manuseio das Vias Aéreas/métodos , Traumatismos Faciais/cirurgia , Intubação Intratraqueal/métodos , Fraturas Cranianas/cirurgia , Adolescente , Adulto , Anestésicos/administração & dosagem , Ossos Faciais/lesões , Ossos Faciais/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Adulto Jovem
18.
Photochem Photobiol Sci ; 16(8): 1230-1237, 2017 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-28613329

RESUMO

Mono-nuclear fac-[Re(CO)3(ph2phen)(4,4'-bpy)]+ and di-nuclear [(ph2phen)(CO)3Re(4,4'-bpy)Re(ph2phen)(CO)3]2+ complexes, ph2phen = 4,7-diphenyl-1,10-phenanthroline and 4,4'-bpy = 4,4'-bipyridine, were synthesized and characterized by 1H NMR, UV-visible and FT-IR spectroscopy. Also, their photophysical properties were investigated using steady-state and time-resolved emission spectroscopy. Both complexes showed UV absorption assigned to intraligand, 1ILph2phen, and metal-to-ligand charge transfer, 1MLCTRe→ph2phen, transitions, and typical 3MLCTRe→ph2phen emission (ϕ = 0.360 and τ = 3.81 µs; ϕ = 0.177 and τ = 1.90 µs for mono- and di-nuclear, respectively). Additionally, the luminescence of these complexes is quenched by hydroquinone with approximately 4 × 109 L mol-1 s-1 rate constant for the bimolecular excited state, kq. The Stern-Volmer constants, KSV, determined by the emission intensity and lifetime showed excellent correlation, which is indicative of the dynamic quenching. The similarity of the bimolecular rate constants between the two complexes implies that the photoinduced electron transfer is the main pathway with a very small (or no) influence of the proton transfer step. The results provide additional insight into the role of the protonable nitrogen atom in the photophysical properties of rhenium(i) complexes, using a dyad architecture.

19.
Cortex ; 88: 42-52, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28068640

RESUMO

Knowledge extracted across previous experiences, or schemas, benefit encoding and retention of congruent information. However, they can also reduce specificity and augment memory for semantically related, but false information. A demonstration of the latter is given by the Deese-Roediger-McDermott (DRM) paradigm, where the studying of words that fit a common semantic schema are found to induce false memories for words that are congruent with the given schema, but were not studied. The medial prefrontal cortex (mPFC) has been ascribed the function of leveraging prior knowledge to influence encoding and retrieval, based on imaging and patient studies. Here, we used transcranial magnetic stimulation (TMS) to transiently perturb ongoing mPFC processing immediately before participants performed the DRM-task. We observed the predicted reduction in false recall of critical lures after mPFC perturbation, compared to two control groups, whereas veridical recall and recognition memory performance remained similar across groups. These data provide initial causal evidence for a role of the mPFC in biasing the assimilation of new memories and their consolidation as a function of prior knowledge.


Assuntos
Transtornos da Memória/fisiopatologia , Rememoração Mental/fisiologia , Córtex Pré-Frontal/fisiologia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Reconhecimento Psicológico/fisiologia , Estimulação Magnética Transcraniana , Adulto Jovem
20.
PhytoKeys ; (74): 35-78, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28127236

RESUMO

This study provides a taxonomic revision for the Neotropical species of the genus Murdannia. Six species are recognized as native, including a new species and a new combination, while two Asian species are recognized as invasive. We present an identification key, a table summarizing the morphologic differences among the species, a new synonym, six lectotypifications, a distribution map, and descriptions, comments and photographic plates for each species. We also provide comments on the morphology of the Neotropical species of Murdannia, comparing them with the Paleotropical species, and a discussion of inflorescence architecture in the genus as a whole.

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