RESUMO
The concept of cognitive radio (CR) as a tool to optimize the obstacle of spectral coexistence has promoted the development of shared satellite-terrestrial wireless networks. Nevertheless, in some applications like Earth Exploration Satellite Services, which demand high spectral efficiency (bps/Hz) for downlink transmissions, spectral coexistence amidst interferences from cellular Base Stations is still challenging. Our research aims to mitigate these interferences on low-orbit satellite downlinks carrying imaging data received from a ground station. In order to fulfill this, we present cognitive radio approaches to enhance spectrum exploitation and introduce the adaptive modulation and coding (MODCOD) technique to increase RF power and spectral efficiencies. Therefore, we propose a combined methodology using CR and adaptive MODCOD (ACM) techniques. Afterwards, we applied the solution by monitoring the signal to interference plus noise ratio and the MODCOD strategy. Finally, we provide a real in situ case study at the Cuiabá ground station located in Brazil's central area, which receives images from an Earth observation satellite (EOS). In addition to demonstrating the strategy effectiveness in this scenario, we conducted a bench test emulating the interfering wireless communication system. In this sense, we demonstrated the proposed approach, successfully mitigating the harmful effects on the received EOS images.
RESUMO
Silver nanoparticles (AgNPs) synthesized from green synthesis using medicinal plants are presented as an option for the development of new antimicrobial agents. In this context, this study aims to evaluate the antimicrobial activity of silver nanoparticles synthesized from the aqueous extract of Schinus terebinthifolius Raddi leaves, popularly known as "aroeira." A 23 factorial design was used to assess the statistical significance of the studied factors, and Box-Behnken design was used to define the optimal conditions for the green synthesis of AgNPs. The studied factors were significant for the synthesis of nanoparticles, and the optimal conditions were pH 9.5, reaction time of 180 min, and 10 g of S. terebinthifolius Raddi leaves. The samples were characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and dynamic light scattering. Antimicrobial activity was evaluated using the broth microdilution method and through the minimum microbicidal concentration. AgNPs showed greater antimicrobial efficacy compared to the extract, both for bacteria and fungi: bacteriostatic activity against all tested bacteria and bactericidal against Pseudomonas aeruginosa, besides fungistatic action against Candida albicans and Candida glabrata. Finally, the aqueous extract of "aroeira" leaves was effective in the synthesis of AgNPs, with greater antimicrobial potential than the extract.
Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Schinus , Prata/farmacologia , Prata/química , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Candida albicans , Espectroscopia de Infravermelho com Transformada de Fourier , Folhas de Planta/química , Testes de Sensibilidade Microbiana , Difração de Raios XRESUMO
Triatoma maculata (Hemiptera, Reduviidae, Triatominae) occurs across dry-to-semiarid ecoregions of northern South America, where it transmits Trypanosoma cruzi, causative agent of Chagas disease. Using 207 field-caught specimens from throughout the species' range, mitochondrial(mt) DNA sequence data, and cytogenetics, we investigated inter-population genetic diversity and the phylogenetic affinities of T. maculata. Mitochondrial DNA sequence analyses (cytb and nd4) disclosed a monophyletic T. maculata clade encompassing three distinct geographic groups: Roraima formation (Guiana shield), Orinoco basin, and Magdalena basin (trans-Andean). Between-group cytb distances (11.0-12.8%) were larger than the ~7.5% expected for sister Triatoma species; the most recent common ancestor of these T. maculata groups may date back to the late Miocene. C-heterochromatin distribution and the sex-chromosome location of 45S ribosomal DNA clusters both distinguished Roraima bugs from Orinoco and Magdalena specimens. Cytb genealogies reinforced that T. maculata is not sister to Triatoma pseudomaculata and probably represents an early (middle-late Miocene) offshoot of the 'South American Triatomini lineage'. In sum, we report extensive genetic diversity and deep phylogeographic structuring in T. maculata, suggesting that it may consist of a complex of at least three sibling taxa. These findings have implications for the systematics, population biology, and perhaps medical relevance of T. maculata sensu lato.
Assuntos
Doença de Chagas , Triatoma , Trypanosoma cruzi , Animais , Triatoma/genética , Filogenia , Doença de Chagas/veterinária , Trypanosoma cruzi/genética , DNA Mitocondrial/genética , Análise Citogenética/veterináriaRESUMO
Chagas disease (CD) still imposes a heavy burden on most Latin American countries. Vector-borne and mother-to-child transmission cause several thousand new infections per year, and at least 5 million people carry Trypanosoma cruzi. Access to diagnosis and medical care, however, is far from universal. Starting in the 1990s, CD-endemic countries and the Pan American Health Organization-World Health Organization (PAHO-WHO) launched a series of multinational initiatives for CD control-surveillance. An overview of the initiatives' aims, achievements, and challenges reveals some key common themes that we discuss here in the context of the WHO 2030 goals for CD. Transmission of T. cruzi via blood transfusion and organ transplantation is effectively under control. T. cruzi, however, is a zoonotic pathogen with 100+ vector species widely spread across the Americas; interrupting vector-borne transmission seems therefore unfeasible. Stronger surveillance systems are, and will continue to be, needed to monitor and control CD. Prevention of vertical transmission demands boosting current efforts to screen pregnant and childbearing-aged women. Finally, integral patient care is a critical unmet need in most countries. The decades-long experience of the initiatives, in sum, hints at the practical impossibility of interrupting vector-borne T. cruzi transmission in the Americas. The concept of disease control seems to provide a more realistic description of what can in effect be achieved by 2030.
Assuntos
Doença de Chagas , Trypanosoma cruzi , Idoso , América/epidemiologia , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/prevenção & controle , Vetores de Doenças , Feminino , Humanos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , GravidezRESUMO
The environmental and health risks associated with the application of synthetic chemical inputs in agriculture increased the demand for technologies that allow higher performance and quality of vegetable crops by implementing synergistic materials with the principles of sustainability. In this work, the seed coating with the biomass of Dunaliella salina incorporated in a bioplastic film of Manihot esculenta (cassava) was evaluated as an initial growth and secondary compounds stimulator of Coriandrum sativum (coriander) plants. The obtained results demonstrated that the coating stimulated an increase in the germination percentage (28.75%) and also in concentration of bioactive compounds, such as the six-fold increment of caffeic acid (13.33 mg 100 g-1). The carbohydrates, lipids, and proteins present in the microalgae biomass seem to be responsible for these increments once they are known for providing energy to the seedling development and coordinating the secondary metabolites synthesis. As conclusion, we consider the coating with biomass of D. salina an alternative for crop improvement that contributes to the development of sustainable agricultural practices.
Assuntos
Biomassa , Clorofíceas , Coriandrum , Microalgas , Desenvolvimento Vegetal , Metabolismo Secundário , Sementes , Ácidos Cafeicos , Carboidratos , Clorofíceas/química , Coriandrum/química , Coriandrum/efeitos dos fármacos , Coriandrum/crescimento & desenvolvimento , Coriandrum/metabolismo , Produção Agrícola/métodos , Lipídeos , Manihot/química , Microalgas/química , Desenvolvimento Vegetal/efeitos dos fármacos , Metabolismo Secundário/efeitos dos fármacos , Sementes/química , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Desenvolvimento SustentávelRESUMO
The state of Pará has recorded seven Leishmania species that cause tegumentary leishmaniasis (TL). Leishmania species induce distinct immunological responses from the host and exhibit resistance to Glucantime, the first-line drug treatment for TL in Brazil. OBJECTIVE: Identify the etiology of TL in an Amazonian city in the state of Pará. MATERIAL AND METHODS: Eleven patients with TL were recruited and nasal swabs, lesion swabs, and skin fragments samples were collected. In the control group (n = 6), only the nasal swabs were collected. Polymerase Chain Reaction (PCR) amplification of the gene region hsp70-234 was performed using the extracted DNA from the samples, from which nine patients with TL and five in the control group were positive. Products were sequenced, mounted in CAP3 software, aligned using MAFFT v.7.221, edited in Geneious software v.8.1.7, and compared and aligned with sequences available in GenBank using the BLAST tool. RESULTS: For patients with TL, six molecular diagnosis at the species level (L. (Viannia) braziliensis (n = 5/9), L. (Viannia) shawi (n = 1/9)) and three at the genus level (Leishmania sp. (n = 3/9)) were obtained. In the control group, four individuals were infected with Leishmania sp. (n = 4/5) and L. (V.) shawi (n = 1/5). CONCLUSION: This is the first report of L. (V.) shawi infection in the mucosal secretion of a healthy person in Brazil. Moreover, genetic variants were identified in the haplotypes of L. (V.) braziliensis in the gene sequence hsp70-234.
Assuntos
Leishmania braziliensis , Leishmania , Leishmaniose Cutânea , Brasil , Humanos , Leishmania/genética , Leishmania braziliensis/genética , Leishmaniose Cutânea/diagnóstico , Reação em Cadeia da PolimeraseRESUMO
The perturbative integral method was applied to quantify the contribution of external forces during a specific interval of time in trajectories of spacecraft around asteroids and under the Luni-solar influence. However, this method has not been used to quantify the contributions of drag in aerocapture and aerobraking. For this reason, the planet Mars is selected to apply this method during an aerogravity-assisted maneuver. Several trajectories are analyzed, making use of a drag device with area to mass ratios varying from 0.0 to 20.0 m2/kg, simulating solar sails or de-orbit devices. The mathematical model is based in the restricted three-body problem. The use of this maneuver makes it possible to obtain the variations of energy in the trajectory, replacing expensive maneuvers based on fuel consumption. To observe the effects of the maneuvers, different values of pericenter velocity and altitude were selected for prograde and retrograde orbits. The innovation of this research is the application of an integral method to quantify the delta-V of the aero gravity maneuver, comparing the cost of the maneuver with the traditional methods of space propulsion. The results allow the identification of orbits with conditions to capture, and the perturbative maps show the velocity variations.
Assuntos
Marte , Voo Espacial , Gravitação , Modelos Teóricos , AstronaveRESUMO
In this study, mineral composition, centesimal composition and lead were evaluated in pine nut seeds (raw and cooked) from five Brazilian states. Mineral composition was determined by ICP OES and lead by GF AAS. The results for minerals were evaluated by Boxplot, PCA and HCA, using the R software. Average minerals in raw and cooked samples (mg 100 g-1) were: 15.2 and 10.8 (Ca), 0.168 and 0.113 (Cu), 0.506 and 0.330 (Fe), 536 and 420 (K), 51.3 and 40.6 (Mg), 0.373 and 0.208 (Mn), 132 and 102 (P) and 0.746 and 0.520 (Zn). The average centesimal composition (raw and cooked) was: 53.5 and 47.2% (moisture), 1.76 and 1.26% (ash), 3.90 and 3.53% (protein), 40.8 and 48.0% (carbohydrate) and 179 and 206 kcal/100 g (total caloric value) and Pb was not detected. The chemometric analysis showed a distinction of raw and cooked samples due to significant nutrient losses after thermal processing.
Assuntos
Araucaria , Nozes , Análise de Dados , Minerais , SementesRESUMO
Chagas disease (CD) still imposes a heavy burden on most Latin American countries. Vector-borne and mother-to-child transmission cause several thousand new infections per year, and at least 5 million people carry Trypanosoma cruzi. Access to diagnosis and medical care, however, is far from universal. Starting in the 1990s, CD-endemic countries and the Pan American Health Organization-World Health Organization (PAHO-WHO) launched a series of multinational initiatives for CD control-surveillance. An overview of the initiatives' aims, achievements, and challenges reveals some key common themes that we discuss here in the context of the WHO 2030 goals for CD. Transmission of T. cruzi via blood transfusion and organ transplantation is effectively under control. T. cruzi, however, is a zoonotic pathogen with 100+ vector species widely spread across the Americas; interrupting vector-borne transmission seems therefore unfeasible. Stronger surveillance systems are, and will continue to be, needed to monitor and control CD. Prevention of vertical transmission demands boosting current efforts to screen pregnant and childbearing-aged women. Finally, integral patient care is a critical unmet need in most countries. The decades-long experience of the initiatives, in sum, hints at the practical impossibility of interrupting vector-borne T. cruzi transmission in the Americas. The concept of disease control seems to provide a more realistic description of what can in effect be achieved by 2030.
RESUMO
The contamination of milk by antibiotic residues is a worldwide health and food safety problem. There is a need to develop new methods for the rapid determination of antibiotic residues in milk. A method has been developed for determining tylosin residues directly in powdered milk using Fourier Transformed Infrared spectroscopy (FTIR). Tylosin is a broad-spectrum macrolide antibiotic. The spectra obtained were submitted to chemometric analysis to obtain a prediction model for tylosin concentration in powdered milk. Using the Boruta algorithm, the absorption bands related to the milk contamination by the antibiotic were identified. Random forest was shown to be adequate for the prediction of tylosin residues in milk at low concentrations (≤ 100 µg L-1) and the prediction model generated showed high correlation and determination coefficients (greater than 0.95). The proposed methodology proved to be efficient for the investigation of antibiotic residues in powdered milk.
Assuntos
Leite , Tilosina , Animais , Antibacterianos/análise , Leite/química , Pós , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Tilosina/análiseRESUMO
Unconventional edible plants (UEP) are potential supplementary sources of minerals and bioactive compounds. However, there is still a gap in the literature on UEP composition. In this study, the multielement/proximate composition of ten UEP from Brazil was evaluated by ICP OES. Furthermore, phenolic bioactives were quantified by HPLC-UV-DAD. The UEP showed high moisture content (84.85-95.27%) and elements (in mg Kg-1): Al (122-657), Ca (145-14,229), Cu (8.3-18.81), Fe (177-586), K (12.46-34.50%), Mg (157-1,552), Mn (16.85-84.96), Na (1,107-23,775), P (2,535-6,127), Si (189-1,695), Sr (25.56-104.63) and Zn (0.3-72.31). Nine phenolic bioactive compounds (1-2,147) and three flavonoids (1-2,042 mg Kg-1) were determined. PCA and HCA grouped samples (Java ginseng, Coriander, Spearmint and Indian borage) rich in minerals. Spearmint showed high levels of transcinamic acid, kaempferol and quercetin. This study contributes to the scientific development and use of UEP.
Assuntos
Oligoelementos , Brasil , Minerais , Análise Multivariada , Plantas Comestíveis , Oligoelementos/análiseRESUMO
In the present work, multivariate designs were used to optimize an alkaline dissolution, assisted by ultrasound energy, procedure of goat meat using tetramethylammonium hydroxide (TMAH) aiming to determine Ca, Cu, Fe, K, Mg, Na and Zn by flame atomic absorption (FAAS) and emission (FAES) spectrometry. The optimal conditions found for the dissolution were in the following ranges: 0.4-0.5 g for the sample mass, 12-15 min of sonication and using 700-1000 µL of 25% TMAH at a temperature of 50 °C. The obtained limits of quantification varied between 0.221 (Mg) and 7.60 (Ca) µg g-1. Accuracy was assessed by comparing the results obtained by applying the proposed method with the digestion in an acid medium using a digesting block and by analyzing bovine liver certified reference material. The application of a t-test revealed that, at a 95% confidence level, there were no significant differences between the values obtained.
Assuntos
Análise de Alimentos/métodos , Carne/análise , Metais/análise , Espectrofotometria Atômica/métodos , Animais , Análise de Alimentos/estatística & dados numéricos , Cabras , Análise Multivariada , Compostos de Amônio Quaternário/química , Solubilidade , Espectrofotometria Atômica/estatística & dados numéricos , TemperaturaRESUMO
Attalea palms provide primary habitat to Rhodnius spp., vectors of Trypanosoma cruzi. Flying from palms, these blood-sucking bugs often invade houses and can infect people directly or via food contamination. Chagas disease (CD) risk may therefore increase when Attalea palms thrive near houses. For example, Attalea dominate many deforested landscapes of eastern Amazonia, where acute-CD outbreaks are disturbingly frequent. Despite this possible link between deforestation and CD risk, the population-level responses of Amazonian Attalea and their resident Rhodnius to anthropogenic landscape disturbance remain largely uncharted. We studied adult Attalea palms in old-growth forest (OGF), young secondary forest (YSF), and cattle pasture (CP) in two localities of eastern Amazonia. We recorded 1856 Attalea along 10 transects (153.6 ha), and detected infestation by Rhodnius spp. in 18 of 280 systematically-sampled palms (33 bugs caught). Distance-sampling models suggest that, relative to OGF, adult Attalea density declined by 70-80% in CP and then recovered in YSF. Site-occupancy models estimate a strong positive effect of deforestation on palm-infestation odds (ßCP-infestation = 4.82±1.14 SE), with a moderate decline in recovering YSF (ßYSF-infestation = 2.66±1.10 SE). Similarly, N-mixture models suggest that, relative to OGF, mean vector density sharply increased in CP palms (ßCP-density = 3.20±0.62 SE) and then tapered in YSF (ßYSF-density = 1.61±0.76 SE). Together, these results indicate that disturbed landscapes may support between ~2.5 (YSF) and ~5.1 (CP) times more Attalea-dwelling Rhodnius spp. per unit area than OGF. We provide evidence that deforestation may favor palm-dwelling CD vectors in eastern Amazonia. Importantly, our landscape-disturbance effect estimates explicitly take account of (i) imperfect palm and bug detection and (ii) the uncertainties about infestation and vector density arising from sparse bug data. These results suggest that incorporating landscape-disturbance metrics into the spatial stratification of transmission risk could help enhance CD surveillance and prevention in Amazonia.
Assuntos
Doença de Chagas/parasitologia , Insetos Vetores/parasitologia , Rhodnius/patogenicidade , Trypanosoma cruzi/patogenicidade , Animais , EcossistemaRESUMO
Engulfment requires the coordinated, targeted synthesis and degradation of peptidoglycan at the leading edge of the engulfing membrane to allow the mother cell to completely engulf the forespore. Proteins such as the DMP and Q:AH complexes in Bacillus subtilis are essential for engulfment, as are a set of accessory proteins including GerM and SpoIIB, among others. Experimental and bioinformatic studies of these proteins in bacteria distinct from Bacillus subtilis indicate that fundamental differences exist regarding the organization and mechanisms used to successfully perform engulfment. As a consequence, the distribution and prevalence of the proteins involved in engulfment and other proteins that participate in different sporulation stages have been studied using bioinformatic approaches. These works are based on the prediction of orthologs in the genomes of representative Firmicutes and have been helpful in tracing hypotheses about the origin and evolution of sporulation genes, some of which have been postulated as sporulation signatures. To date, an extensive study of these signatures outside of the representative Firmicutes is not available. Here, we asked whether phyletic profiles of proteins involved in engulfment can be used as signatures able to describe the sporulation phenotype. We tested this hypothesis in a set of 954 Firmicutes, finding preserved phyletic profiles defining signatures at the genus level. Finally, a phylogenetic reconstruction based on non-redundant phyletic profiles at the family level shows the non-monophyletic origin of these proteins due to gain/loss events along the phylum Firmicutes.
Assuntos
Membrana Celular/metabolismo , Membrana Celular/microbiologia , Genômica , Peptidoglicano/metabolismo , Bacillus subtilis/genética , Parede Celular/metabolismo , Esporos Bacterianos/genéticaRESUMO
As roupas constituem, em parte, a maneira como as pessoas vivem e expressam as necessidades humanas que avançam vorazmente sobre o sistema natural. Sob forma de vestuário, é possível visualizar a representatividade da cadeia têxtil no cotidiano das pessoas, os efeitos e influência da produção, consumo e descarte na sociedade. Do montante produzido anualmente, menos de 1% desses materiais são reciclados em novas roupas ou outros produtos. O setor têxtil é intensivo na extração de recursos e geração de resíduos, possui altos índices de desperdício e é extremamente poluidor. O Brasil possui a quinta maior cadeia têxtil do mundo. A economia circular e a economia criativa podem contribuir neste enfrentamento pelo seu potencial de promover a reutilização de recursos existentes e a redução de impactos sociais, ambientais e à saúde. Nesse contexto, o objetivo deste estudo é analisar empresas da cadeia têxtil que adotam princípios da economia criativa e da economia circular com o intuito de identificar práticas que minimizam os impactos ambientais de resíduos têxteis e expandem a consciência ambiental de consumidores e empresas. A partir da revisão bibliográfica sistemática e das informações obtidas em visitas técnicas, com observação de campo e registro fotográfico, assim como de entrevistas com base em roteiro pré-elaborado com os empreendedores, foi possível observar os princípios da economia circular e da economia criativa como diferencial estratégico do negócio. Foram identificados alguns marcadores que alicerçam as práticas sustentáveis desenvolvidas nos negócios analisados como: i) gestão da parceria e alinhamento de propósito; ii) Gestão do ciclo de vida ou associação aos fluxos de resíduos dos grandes geradores; iii) Logística reversa e a estruturação de custos para sua viabilidade. O estudo de caso evidenciou como diferentes domínios de conhecimento inter-relacionam os temas de economia criativa e economia circular de forma hierárquica. Assim, foi elaborado framework de planejamento estratégico e os dados levantados durante a pesquisa foram organizados em website, consolidando imagens e conceitos para divulgação da pesquisa, e apoiar empreendedores na concepção de novos negócios cujo propósito é a sustentabilidade.
Clothes constitute, in part, the way in which people live and express human needs that voraciously advance over the natural system. In the form of clothing, it is possible to visualize the representativeness of the textile chain in peoples daily lives, the effects and influence of production, consumption and disposal in society. Of the amount produced annually, less than 1% of these materials are recycled into new clothes or other products. The textile sector is intensive in resource extraction and waste production, has high levels of waste and is extremely polluting. Brazil has the fifth largest textile chain in the world. The circular economy and the creative economy can contribute to this confrontation by their potential to promote the reuse of existing resources and the reduction of social, environmental and health impacts. In this context, the objective of this study is to analyze companies in the textile chain that adopt principles of the creative economy and the circular economy in order to identify practices that minimize the environmental impacts of textile waste and expand the environmental awareness of consumers and companies. From the systematic bibliographic review and the information obtained in technical visits, with field observation and photographic record, as well as interviews based on a pre-prepared script with the entrepreneurs, it was possible to observe the principles of circular economy and creative economy as strategic differential of the business. Some markers were identified that underpin the sustainable practices developed in the analyzed businesses, such as: i) management of the partnership and alignment of purpose; ii) Life cycle management or association with waste streams from large generators; iii) Reverse logistics and cost structuring for its viability. The case study showed how different domains of knowledge interrelate the themes of creative economy and circular economy in a hierarchical way. Thus, a strategic planning framework was developed and the data collected during the research were organized on a website, consolidating images and concepts for disseminating the research, and supporting entrepreneurs in the conception of new businesses whose purpose is sustainability.
Assuntos
Indústria Têxtil , Têxteis , Vestuário , Gerenciamento de Resíduos , Desenho , EconomiaRESUMO
The aim of this work was to investigate the phenolic content and antioxidant capacity of infusions of commercial herb samples (fennel, anise, peppermint, lemon grass and lemon balm) popularly consumed in Brazil. The infusion preparation for phenolic extraction was optimized using multivariate planning. Spectrophotometric methods were used to determine in vitro antioxidant activity and total phenolic and flavonoid content. Peppermint infusions had higher phenolic content and antioxidant potential. It was developed and validated a method by HPLC-DAD for the determination of caffeine, phenolic acids and flavonoids and applied for the analysis of the composition of the infusions. Higher concentrations were obtained for chlorogenic and p-coumaric phenolic acids and for flavonoids rutin and catechin. Principal Components Analysis and Hierarchical Cluster Analysis were applied for the comparative evaluation of the phenolic composition of the infusions. The multivariate analyzes indicate that the phenolic profile for the samples of the same species tend to present greater similarities in relation to other herbs and one of the analyzed samples, commercialized as anise, does not belong to the P. anisum species.
Assuntos
Antioxidantes , Extratos Vegetais , Brasil , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Fenóis/análiseRESUMO
The American cutaneous (CL) and visceral leishmaniasis (VL) are zooanthroponoses transmitted by sand flies. Brazil records thousands of human leishmaniasis cases annually. Dogs are reservoirs of Leishmania infantum, which causes VL, but their role in the transmission cycle of CL is debatable. Wild mammals are considered reservoirs of the aetiological agents of CL (Leishmania spp.). OBJECTIVE: To describe the aetiology of leishmaniasis in dogs in an endemic area for CL and VL in the Amazon, Brazil. METHODS: Clinical evaluation and blood collection of 40 dogs from the villages Ubim (20) and Socorro (20), city of Tomé-Açu, state of Pará, were carried out. The DNA extracted from the blood was used for PCR with Leishmania-specific primers targeting the hsp70-234 gene sequence. Products were sequenced (ABI3500XL), and the sequences were aligned, edited (BioEdit), and analyzed (Blastn). RESULTS: Of the 34 amplified samples, 21 were sequenced, namely Leishmania infantum (12), L. guyanensis (5), L. braziliensis (3), and Leishmania sp. (01). CONCLUSION: Given the diversity of circulating pathogens, elucidation of the role of the dog in the Leishmania spp. cycle in Amazonian villages is imperative to the surveillance of CL in the region. We present the first report in Brazil, confirmed by sequencing, of canine infection by L. guyanensis, a species highly resistant to treatment in humans, with the drug of first choice (Glucantime®).
Assuntos
Doenças do Cão , Leishmania guyanensis , Leishmaniose , Animais , Brasil/epidemiologia , Cidades , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Leishmania/classificação , Leishmania/genética , Leishmania guyanensis/genética , Leishmaniose/epidemiologia , Leishmaniose/parasitologia , Leishmaniose/veterináriaRESUMO
In this work is presented the development of a method for As and Se determination in crude palm oil samples by hydride generation atomic fluorescence spectrometry and Hg by cold vapor atomic fluorescence spectrometry after ultrasound-assisted emulsification and extraction induced by emulsion breaking (EIEB). The optimization of the method was carried out by multivariate designs. The developed method has presented limits of quantification (LOQ) of 0.72, 0.12, and 1.5 µg L-1 for As, Hg, and Se, respectively. The precisions of the proposed method expressed as repeatability were 0.92, 2.2, and 3.7% RSD for 2 µg L-1 (n = 10) of As, Hg and Se, respectively. The developed methodology was applied in palm oil samples collected in the Bahia State. Concentrations (µg L-1) found in the samples were between Assuntos
Arsênio/análise
, Emulsões/química
, Análise de Alimentos/métodos
, Mercúrio/análise
, Óleo de Palmeira/análise
, Selênio/análise
, Fracionamento Químico/métodos
, Análise de Alimentos/estatística & dados numéricos
, Contaminação de Alimentos
, Gases/química
, Limite de Detecção
, Análise Multivariada
, Óleo de Palmeira/química
, Espectrometria de Fluorescência/métodos
, Espectrofotometria Atômica/métodos
RESUMO
In this study, mechanical mixtures of sugarcane bagasse and iron salts (nitrate, acetate, or a mixture of both) were subjected to thermal decomposition for producing iron oxide and carbonaceous composite materials, which were evaluated as adsorbents for removing dyes from water using methylene blue (MB) as a model system. Aiming to optimize the conditions for obtaining composite adsorbents, the Box-Behnken design (BBD) was used to study the effects of mass sugarcane bagasse/mass iron salt, type of mixture of sugarcane bagasse/iron salt, and temperature on the response to be obtained (adsorption capacity, q e ) before the execution of the adsorption tests. The synthesized composites were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The relationship between the characteristics of different materials, based on the processing of statistical data and the results of the adsorption tests, helped determine the routes that led to formation of composites with the most suitable properties for the removal of MB dye. Different phases, such as magnetite (Fe3O4) and/or maghemite (γ-Fe2O3) and iron carbide (Fe3C), were formed. The composites that presented the highest q e values were SB/IN 1:1 (600°C) and SB/IN-IA 1:2 (400°C). The first, which contained iron carbide (Fe3C), according to the XRD results, also showed larger BET surface area than the other composites. These properties may have contributed to the higher MB adsorption efficiency of this material in aqueous medium. The sample SB/IN-IA 1:2 (400°C) had lower specific area and was composed of magnetite and/or maghemite phases. In this case, the high q e was probably associated with the surface properties promoted by combination with the carbonaceous material, favoring interactions with MB.