15 results on '"Leonardo Araujo"'
Search Results
2. 13C NMR as an analytical tool for the detection of carbonic acid and pKa determination.
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Oliveira, Daniel Rossado, da Costa, Eric Tavares, Schenberg, Leonardo Araujo, Ducati, Lucas Colucci, and do Lago, Claudimir Lucio
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CARBONIC acid ,NUCLEAR magnetic resonance spectroscopy ,ATMOSPHERIC carbon dioxide ,CARBON sequestration ,CHEMICAL shift (Nuclear magnetic resonance) ,CARBAMIC acid ,IONIC strength - Abstract
NMR spectroscopy has become a standard technique in studies both on carbon capture and storage. 13C NMR allows the detection of two peaks for carbonated aqueous samples: one for CO2(aq) and another one for the species H2CO3, HCO3−, and CO32−—herein collectively named HxCO3x‐2. The chemical shift of this second peak depends on the molar fraction of the three species in equilibrium and has been used to assess the equilibrium between HCO3− and CO32−. The detection of H2CO3 at low pH solutions is hindered, because of the concurrent liberation of CO2 when the medium is acidified. Herein, a valved NMR tube facilitates the detection of the HxCO3x‐2 peak across a wide pH range, even at pH 1.8 where the dominant species is H2CO3. The method employed the formation of frozen layers of NaH13CO3 and acid solutions within the tube, which are mixed as the tube reaches room temperature. At this point, the tube is already securely sealed, preventing any loss of CO2 to the atmosphere. A spectrophotometry approach allowed the measurement of the actual pH inside the pressurized NMR tube. The chemical shift for H2CO3 was determined as 160.33 ± 0.03 ppm, which is in good agreement with value obtained by DFT calculations combined with Car–Parrinello molecular dynamics. The H2CO3 pKa value determined by the present method was 3.41 ± 0.03, for 15% D2O aqueous medium and 0.8 mol/L ionic strength. The proposed method can be extended to studies about analogs such as alkyl carbonic and carbamic acids. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Designing and validation of specific primers for the quantitative detection of bacteria in sugarcane inoculant.
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Da Silva, Cleudison Gabriel Nascimento, Monteiro, Edevaldo de Castro, Diniz, Priscila Pereira, Terra, Leonardo Araujo, Schwab, Stefan, Reis, Veronica Massena, Simoes-Araujo, Jean Luiz, and Urquiaga, Segundo
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- 2023
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4. Brain Neuroplasticity after Treatment with Antiseizure: A Review.
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Silva de Souza, Débora Lopes, Goes e. Silva Costa, Hosana Mirelle, Neta, Francisca Idalina, de Gois Morais, Paulo Leonardo Araujo, de Medeiros Guerra, Luís Marcos, Pierdoná Guzen, Fausto, Clebeson de Oliveira, Lucídio, de Paiva Cavalcanti, José Rodolfo Lopes, Cavalcanti de Albuquerque, Cynthia, and Lopes de Vasconcelos, Claudio
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NEUROPLASTICITY ,SCIENTIFIC literature ,VALPROIC acid ,DRUG efficacy ,PHENOBARBITAL ,FAMILIAL Mediterranean fever - Abstract
Epilepsy is a disease characterized by the periodic occurrence of seizures. Seizures can be controlled by antiseizure medications, which can improve the lives of individuals with epilepsy when given proper treatment. Therefore, this study aimed to review the scientific literature on brain neuroplasticity after treatment with antiseizure drugs in different regions of the brain. According to the findings, that several antiseizure, such as lamotrigine, diazepam, levetiracetam, and valproic acid, in addition to controlling seizures, can also act on neuroplasticity in different brain regions. The study of this topic becomes important, as it will help to understand the neuroplastic mechanisms of these drugs, in addition to helping to improve the effectiveness of these drugs in controlling the disease. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Metabolic, Nutritional and Morphophysiological Behavior of Eucalypt Genotypes Differing in Dieback Resistance in Field When Submitted to PEG-Induced Water Deficit.
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Caetano-Madeira, Débora Durso, Omena-Garcia, Rebeca Patricia, Elerati, Tamiris Lopes, da Silva Lopes, Camila Batista, Corrêa, Thais Roseli, de Souza, Genaína Aparecida, Oliveira, Leonardo Araujo, Cruz, Cosme Damião, Bhering, Leonardo Lopes, Nunes-Nesi, Adriano, da Costa, Weverton Gomes, and Picoli, Edgard Augusto de Toledo
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DIEBACK ,WATER efficiency ,GENOTYPES ,EUCALYPTUS ,CARBON fixation ,LEAF area - Abstract
Dieback is a physiological disorder that has caused losses on eucalyptus plantations. Thinking that water stress is one of the triggers for the physiological disorder and aiming at the early identification of tolerant genotypes, we evaluated plantlets of four commercial clones with divergent behavior in field conditions. The plantlets were grown in a greenhouse where the drought conditions were provided by the application of polyethylene glycol 6000 solutions at 100 and 300 g L
−1 . After water deficit treatments, the morphological, physiological, nutritional and metabolic analyses were performed. SuzT maintained the carbon fixation and the instantaneous water use efficiency, even under water deficit, while sustaining growth. This resulted in higher leaf area and total dry mass in SuzT. Despite higher photosynthetic rate, SuzS exhibited reduced dry biomass accumulation, implying less efficient carbon use. SuzT revealed a higher level of calcium that supports cell structure and homeostasis and indicates higher capacity to manage specific resources and survival under water deficit. SuzT suffered reduction in some free amino acids; however, there was no significant variation for total amino acid content. The principal component and cluster analyses indicated that SuzMT and SuzTP genotypes behave similarly to SuzT under water deficit, while SuzS clustered in isolation. Our results support that there are common trends in water deficit responses for contrasting eucalypt genotypes. The existence of other strategies coping with water deficit resistance is not discarded and should be further evaluated. [ABSTRACT FROM AUTHOR]- Published
- 2023
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6. Developing a Roadmap to Define a Potential Ideotype for Drought Tolerance in Eucalyptus.
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Pita-Barbosa, Alice, Oliveira, Leonardo Araujo, Barros, Nairam Félix de, Hodecker, Bárbara Elias Reis, Oliveira, Franciele S, Araújo, Wagner L, and Martins, Samuel C V
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Climate change is escalating the water crisis worldwide, leading to unpredictable water availability and water scarcity, which is among the main environmental factors affecting plant growth and yield, severely affecting the productivity of planted forests, most of them composed of Eucalyptus species. The selection of genotypes capable of growing and surviving under water scarcity is required for eucalypt cultivation in areas with seasonal or continuous drought episodes. To achieve this goal, there is the current need for the identification of potential drought tolerance bioindicators, which is a challenging task since plant responses to drought involve numerous genes and strategies. We posit that eco-physiological and morphoanatomical analyses in combination with molecular approaches could help fill the current knowledge gap. In this review, we summarize recent advances in the identification of potential indicators of drought tolerance in Eucalyptus and discuss the typical responses to drought stress, as well as their importance as bioindicators for the development of a drought-tolerant eucalypt ideotype. [ABSTRACT FROM AUTHOR]
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- 2023
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7. Aedes fluviatilis cell lines as new tools to study metabolic and immune interactions in mosquito-Wolbachia symbiosis.
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Conceição, Christiano Calixto, da Silva, Jhenifer Nascimento, Arcanjo, Angélica, Nogueira, Cíntia Lopes, de Abreu, Leonardo Araujo, de Oliveira, Pedro Lagerblad, Gondim, Katia C., Moraes, Bruno, de Carvalho, Stephanie Serafim, da Silva, Renato Martins, da Silva Vaz Jr., Itabajara, Moreira, Luciano Andrade, and Logullo, Carlos
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CELL lines ,GRAM-negative bacteria ,AEDES ,METABOLIC regulation ,SYMBIOSIS - Abstract
In the present work, we established two novel embryonic cell lines from the mosquito Aedes fluviatilis containing or not the naturally occurring symbiont bacteria Wolbachia, which were called wAflu1 and Aflu2, respectively. We also obtained wAflu1 without Wolbachia after tetracycline treatment, named wAflu1.tet. Morphofunctional characterization was performed to help elucidate the symbiont-host interaction in the context of energy metabolism regulation and molecular mechanisms of the immune responses involved. The presence of Wolbachia pipientis improves energy performance in A. fluviatilis cells; it affects the regulation of key energy sources such as lipids, proteins, and carbohydrates, making the distribution of actin more peripheral and with extensions that come into contact with neighboring cells. Additionally, innate immunity mechanisms were activated, showing that the wAflu1 and wAflu1.tet cells are responsive after the stimulus using Gram negative bacteria. Therefore, this work confirms the natural, mutually co-regulating symbiotic relationship between W. pipientis and A. fluviatilis, modulating the host metabolism and immune pathway activation. The results presented here add important resources to the current knowledge of Wolbachia-arthropod interactions. [ABSTRACT FROM AUTHOR]
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- 2021
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8. Upper Airway Findings and Markers of Lung Disease Progression in Patients with Cystic Fibrosis.
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Steffen, Luciane Mazzini, Pezzin, Luise Sgarabotto, Sulis, Natassia, Steffen, Nedio, and Pinto, Leonardo Araujo
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CYSTIC fibrosis ,LUNG diseases ,DISEASE progression ,NASAL polyps ,BODY mass index ,BRONCHIECTASIS ,NASAL tumors - Abstract
Introduction Cystic fibrosis (CF) is a genetic disease that limits the quality of life mainly due to respiratory symptoms. The relationship between findings of the upper airways and CF lung disease is not yet completely understood. Objective The aim of the present study is to describe the most frequent nasal findings and pathogens in patients with CF and investigate the association between the findings of the upper respiratory tract and markers of lung disease progression. Methods Retrospective study in patients with CF from the Pediatric Pulmonology Department who underwent otorhinolaryngological evaluation between 2015 and 2017. Nasal endoscopy and nasal swab collection were part of the evaluation. The severity markers used were: percentage of predicted forced expiratory volume in the first second (FEV1%), body mass index (BMI) and the Shwachman-Kulczycki (SK) clinical score. Results A total of 48 patients with CF were included. The mean of the predicted percentage of FEV1% was 83.36 ± 30.04. The average 14 and SK score 89.11 ± 10.50. The bacteriology of the nasal swab was positive in 27 (54.1%) patients. Staphylococcus aureus was positive in 18 patients, Pseudomonas aeruginosa in 5, Pseudomonas cepacea in 3 and Stenotrophomonas maltophila in 1 patient.Nasal polypswere found in nine participants. Nasal polyps were found in nine participants and were associated with lower SK score. Conclusion The pathogens found in the upper airway were, in order: S. aureus, P. aeruginosa, P. cepacea e S. maltophila. The presence of polyps in the nasal cavity showed statistical significance and appears to have association with the prognostic factor measured by the SK score. [ABSTRACT FROM AUTHOR]
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- 2020
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9. Genomic characterization of Nitrospirillum amazonense strain CBAmC, a nitrogen-fixing bacterium isolated from surface-sterilized sugarcane stems.
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Schwab, Stefan, Terra, Leonardo Araujo, and Baldani, José Ivo
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SUGARCANE ,BIOSYNTHESIS ,AZOSPIRILLUM ,BACTERIAL communities ,NITROGENASE genetics - Abstract
Nitrospirillum amazonense is a nitrogen-fixing bacterium that shows potential to promote plant growth when inoculated into sugarcane and rice plants. This microorganism has been the subject of biochemical and genetic characterization to elucidate important functions related to host plant interaction and growth promotion, including the determination of draft genome sequences of two strains, Y2 and CBAmC, the second of which is the aim of the present study. CBAmC has been isolated from sugarcane (Saccharum spp.), and is currently used in a sugarcane consortium inoculant with four other nitrogen-fixing bacterial strains. The present paper describes a significant improvement in the genome sequence and assembly for the N. amazonense strain CBAmC, and determination for the first time of a complete genome sequence for this bacterial species, using PacBio technology. The analysis of the genomic data obtained allowed the discovery of genes coding for metabolic pathways and cellular structures that may be determinant for the success of the bacterial establishment and colonization into the host sugarcane plant, besides conferring important characteristics to the inoculant. These include genes for the use of sucrose and N-glycans, biosynthesis of autoinducer molecules, siderophore production and acquisition, auxin and polyamine biosynthesis, flagellum, σ-fimbriae, a variety of secretion systems, and a complete denitrification system. Concerning genes for nitrogenase and auxiliary proteins, it was possible to corroborate literature data that in N. amazonense these probably had originated from horizontal gene transfer, from bacteria of the Rhizobiales order. The complete genomic sequence of the CBAmC strain of N. amazonense revealed that the bacterium harbors four replicons, including three chromosomes and one chromid, a profile that coincides with that of other two strains, according to literature data, suggesting that as a replicon pattern for the species. Finally, results of phylogenomic analyses in this work support the recent reclassification of the species, separating it from the Azospirillum genus. More importantly, results of the present work shall guide subsequent studies on strain CBAmC as well as the development of a sugarcane inoculant. [ABSTRACT FROM AUTHOR]
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- 2018
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10. PALABRA DE LECTOR.
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Araque, José Leonardo Araujo
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- 2023
11. Uso de macrolídeos em doenças pulmonares: controvérsias da literatura recente.
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Ferreira da Silva Filho, Luiz Vicente Ribeiro, Pinto, Leonardo Araujo, and Stein, Renato Tetelbom
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Copyright of Jornal de Pediatria is the property of Sociedade Brasileira de Pediatria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2015
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12. Non-Invasive Delivery of dsRNA into De-Waxed Tick Eggs by Electroporation.
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Ruiz, Newton, Abreu, Leonardo Araujo de, Parizi, Luís Fernando, Kim, Tae Kwon, Mulenga, Albert, Braz, Gloria Regina Cardoso, Jr.Vaz, Itabajara da Silva, and Logullo, Carlos
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DOUBLE-stranded RNA ,ELECTROPORATION ,TICKS ,GENE silencing ,RNA interference ,PROTEIN kinase B - Abstract
RNA interference-mediated gene silencing was shown to be an efficient tool for validation of targets that may become anti-tick vaccine components. Here, we demonstrate the application of this approach in the validation of components of molecular signaling cascades, such as the Protein Kinase B (AKT) / Glycogen Synthase Kinase (GSK) axis during tick embryogenesis. It was shown that heptane and hypochlorite treatment of tick eggs can remove wax, affecting corium integrity and but not embryo development. Evidence of AKT and GSK dsRNA delivery into de-waxed eggs of via electroporation is provided. Primers designed to amplify part of the dsRNA delivered into the electroporated eggs dsRNA confirmed its entry in eggs. In addition, it was shown that electroporation is able to deliver the fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI). To confirm gene silencing, a second set of primers was designed outside the dsRNA sequence of target gene. In this assay, the suppression of AKT and GSK transcripts (approximately 50% reduction in both genes) was demonstrated in 7-day-old eggs. Interestingly, silencing of GSK in 7-day-old eggs caused 25% reduction in hatching. Additionally, the effect of silencing AKT and GSK on embryo energy metabolism was evaluated. As expected, knockdown of AKT, which down regulates GSK, the suppressor of glycogen synthesis, decreased glycogen content in electroporated eggs. These data demonstrate that electroporation of de-waxed R. microplus eggs could be used for gene silencing in tick embryos, and improve the knowledge about arthropod embryogenesis. [ABSTRACT FROM AUTHOR]
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- 2015
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13. Non-Classical Gluconeogenesis-Dependent Glucose Metabolism in Rhipicephalus microplus Embryonic Cell Line BME26.
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da Silva, Renato Martins, Noce, Bárbara Della, Waltero, Camila Fernanda, Costa, Evenilton Pessoa, de Abreu, Leonardo Araujo, Naftaly Wang'ombe Githaka, Moraes, Jorge, Gomes, Helga Fernandes, Konnai, Satoru, da Silva Vaz Jr., Itabajara, Ohashi, Kazuhiko, and Logullo, Carlos
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GENE expression in mammals ,REGULATION of gluconeogenesis ,RHIPICEPHALUS ,GLUCOSE metabolism ,GLYCOLYSIS ,PYRUVATE kinase - Abstract
In this work we evaluated several genes involved in gluconeogenesis, glycolysis and glycogen metabolism, the major pathways for carbohydrate catabolism and anabolism, in the BME26 Rhipicephalus microplus embryonic cell line. Genetic and catalytic control of the genes and enzymes associated with these pathways are modulated by alterations in energy resource availability (primarily glucose). BME26 cells in media were investigated using three different glucose concentrations, and changes in the transcription levels of target genes in response to carbohydrate utilization were assessed. The results indicate that several genes, such as glycogen synthase (GS), glycogen synthase kinase 3 (GSK3), phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6 phosphatase (GP) displayed mutual regulation in response to glucose treatment. Surprisingly, the transcription of gluconeogenic enzymes was found to increase alongside that of glycolytic enzymes, especially pyruvate kinase, with high glucose treatment. In addition, RNAi data from this study revealed that the transcription of gluconeogenic genes in BME26 cells is controlled by GSK-3. Collectively, these results improve our understanding of how glucose metabolism is regulated at the genetic level in tick cells. [ABSTRACT FROM AUTHOR]
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- 2015
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14. Glycogen Synthase Kinase-3 is involved in glycogen metabolism control and embryogenesis of Rhodnius prolixus.
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MURY, FLÁVIA B., LUGON, MAGDA D., DA FONSECA, RODRIGO NUNES, SILVA, JOSE R., BERNI, MATEUS, ARAUJO, HELENA M., FONTENELE, MARCIO RIBEIRO, ABREU, LEONARDO ARAUJO DE, DANSA, MARÍLVIA, BRAZ, GLÓRIA, MASUDA, HATISABURO, and LOGULLO, CARLOS
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GLYCOGEN synthase kinase-3 ,RHODNIUS prolixus ,INSECT physiology ,GENE silencing ,EMBRYOLOGY ,INSECTS - Abstract
Rhodnius prolixus is a blood-feeding insect that transmits Trypanosoma cruzi and Trypanosoma rangeli to vertebrate hosts. Rhodnius prolixus is also a classical model in insect physiology, and the recent availability of R. prolixus genome has opened new avenues on triatomine research. Glycogen synthase kinase 3 (GSK-3) is classically described as a key enzyme involved in glycogen metabolism, also acting as a downstream component of the Wnt pathway during embryogenesis. GSK-3 has been shown to be highly conserved among several organisms, mainly in the catalytic domain region. Meanwhile, the role of GSK-3 during R. prolixus embryogenesis or glycogen metabolism has not been investigated. Here we show that chemical inhibition of GSK-3 by alsterpaullone, an ATP-competitive inhibitor of GSK3, does not affect adult survival rate, though it alters oviposition and egg hatching. Specific GSK-3 gene silencing by dsRNA injection in adult females showed a similar phenotype. Furthermore, bright field and 4’−6-diamidino-2-phenylindole (DAPI) staining analysis revealed that ovaries and eggs from dsGSK-3 injected females exhibited specific morphological defects. We also demonstrate that glycogen content was inversely related to activity and transcription levels of GSK-3 during embryogenesis. Lastly, after GSK-3 knockdown, we observed changes in the expression of the Wingless (Wnt) downstream target β-catenin as well as in members of other pathways such as the receptor Notch. Taken together, our results show that GSK-3 regulation is essential for R. prolixus oogenesis and embryogenesis. [ABSTRACT FROM PUBLISHER]
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- 2016
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15. Correction: Non-Invasive Delivery of dsRNA into De-Waxed Tick Eggs by Electroporation.
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Ruiz, Newton, de Abreu, Leonardo Araujo, Parizi, Luís Fernando, Kim, Tae Kwon, Mulenga, Albert, Cardoso Braz, Gloria Regina, da Silva Vaz, Itabajara, and Logullo, Carlos
- Subjects
DOUBLE-stranded RNA ,ELECTROPORATION ,TICKS ,INVERTEBRATE eggs ,PUBLISHING ,PERIODICAL publishing - Published
- 2015
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