Evaluation of the antimicrobial activity of silver nanoparticles biosynthesized from the aqueous extract of Schinus terebinthifolius Raddi leaves.

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.

Molecular and cytogenetic evidence for sibling species in the Chagas disease vector Triatoma maculata.

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.

Cognitive Radio Strategy Combined with MODCOD Technique to Mitigate Interference on Low-Orbit Satellite Downlinks.

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.

Chagas disease control-surveillance in the Americas: the multinational initiatives and the practical impossibility of interrupting vector-borne Trypanosoma cruzi transmission.

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.

Effect of the seed coating with biomass of Dunaliella salina on early plant growth and in the secondary metabolites content of Coriandrum sativum.

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.

Phenolic content and antioxidant capacity of infusions herbs: Optimization of phenolic extraction and HPLC-DAD method.

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.

Optimization of the Production Parameters of Composites from Sugarcane Bagasse and Iron Salts for Use in Dye Adsorption.

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.

Spray-dried microcapsules of anthocyanin-rich extracts from Euterpe edulis M. as an alternative for maintaining color and bioactive compounds in dairy beverages.

Color is a sensory attribute that influences the acceptance of food and dyes are added into food products to provide them attractiveness. In this context, anthocyanins have merged as an alternative to synthetic dyes. This study aimed to develop food model systems of fermented or unfermented dairy beverages containing added microencapsulated anthocyanin-rich extracts from juçara palm fruit. The stabilities of both pigment and beverage throughout storage in opaque or transparent packaging have been evaluated. Acidity, pH and anthocyanin content in both beverages did not vary during 28 days of storage, and the content of bioactive compounds did not decrease over time. A slight overall color difference that is probably invisible to naked eyes was detected between the beverages analyzed at days 0 and 28. The potential of applying microencapsulated natural pigments into dairy matrices is an effort to increase their nutritional and sensorial values.

Satellite Telemetry and Image Reception with Software Defined Radio Applied to Space Outreach Projects in Brazil.

Software Defined Radio (SDR) uses a processor, a special receiver and software that play the main parts of the receiver (mixer, filters, amplifiers, modulators, demodulators, etc.) and it is quite advantageous for its flexibility and compact size as it reduces the amount of hardware components while adapting for different needs. This work briefly presents the SDR concept and approach for obtaining satellite telemetries and imagery in the context of different modulation schemes, link budget requirements and different satellites types. Two case studies are presented for supporting affordable ground segment and promoting satellites projects in Brazil. Reception from the 1st Brazilian picosatellite, Tancredo-1, with specific software developed, UbaTM is presented for obtaining satellite raw telemetries, convert them to engineering value and friendly present on user screen. A series of support software packages are then introduced so that one can pipeline various operations and automate tasks in the ground station. Finally, a second study case was performed in order to receive NOAA class satellites imagery over VHF band and decoded by specific software freely available. Using the proposed SDR approach, it can adapt to projects mainly those with a limited budget and outreach for major inclusion on space topics in Brazil.

Multivariate optimization of a method for antimony determination by hydride generation atomic fluorescence spectrometry in hair samples of patients undergoing chemotherapy against Leishmaniasis.

A method was developed for determination of total antimony in hair samples from patients undergoing chemotherapy against Leishmaniasis based on the administration of pentavalent antimonial drugs. The method is based on microwave assisted digestion of the samples in a pressurized system, reduction of Sb5+ to Sb3+ with KI solution (10% w/v) in ascorbic acid (2%, w/v) and its subsequent determination by hydride generation atomic fluorescence spectrometry (HG-AFS). The proportions of each component (HCl, HNO3 and water) used in the digestion were studied applying a constrained mixtures design. The optimal proportions found were 50% water, 25% HNO3 and 25% HCl. Variables involved in the generation of antimony hydride were optimized using a Doehlert design revealing that good sensitivity is found when using 2.0% w/v NaBH4 and 4.4 mol L-1 HCl. Under the optimum experimental conditions, the method allows the determination of antimony in hair samples with detection and quantification limits of 1.4 and 4.6 ng g-1, respectively, and precision expressed as relative standard deviation (RSD) of 2.8% (n = 10 to 10.0 mg L-1). The developed method was applied in the analysis of hair samples from patients who take medication against Leishmaniasis.

Mineral composition, nutritional properties, total phenolics and flavonoids compounds of the atemoya fruit (Annona squamosa L. x Annona cherimola Mill.) and evaluation using multivariate analysis techniques.

The atemoya is a hybrid fruit obtained by crossing of cherimoya (Annona cherimola Mill.) with sweet sop (Annona squamosa L.). The information about chemical composition of atemoya is scarce. The mineral composition was evaluated employing Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) and the centesimal composition and the physico-chemical parameters were assessed employing procedures described in the AOAC methods. The total phenolic compounds (TPC) and total flavonoids (TF) were determined using spectroanalytical methods. Considering the Reference Daily Intake (RDI), the concentrations of K, Cu and Vitamin C found in atemoya were the highest, representing about 32, 23 and 37% of the RDI, respectively. The total carbohydrates were 32 g 100g-1 and the soluble solids was equivalent to (32.50 ± 0.03) °Brix. The result for TPC was 540.47 ± 2.32 mgGAE 100 g-1 and the TF was 11.56 ± 1.36 mgQE 100 g-1. The exploratory evaluation of 42 atemoya samples was performed through Principal Component Analysis (PCA), which discriminated green and ripe fruits according to their mineral composition. The elements that contributed most for the variability between green and ripe fruits were: Ba, Ca, Cu, K, Mg and P.

Removal of mercury(II) ions in aqueous solution using the peel biomass of Pachira aquatica Aubl: kinetics and adsorption equilibrium studies.

Mercury is a highly toxic substance that is a health hazard to humans. This study aims to investigate powders obtained from the peel of the fruit of Pachira aquatica Aubl, in its in natura and/or acidified form, as an adsorbent for the removal of mercury ions in aqueous solution. The materials were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. The infrared spectra showed bands corresponding to the axial deformation of carbonyls from carboxylic acids, the most important functional group responsible for fixing the metal species to the adsorbent material. The thermograms displayed mass losses related to the decomposition of three major components, i.e., hemicellulose, cellulose, and lignin. The adsorption process was evaluated using cold-vapor atomic fluorescence spectrometry (CV AFS) and cold-vapor atomic absorption spectrometry (CV AAS). Three isotherm models were employed. The adsorption isotherm model, Langmuir-Freundlich, best represented the adsorption process, and the maximum adsorption capacity was predicted to be 0.71 and 0.58 mg g(-1) at 25 °C in nature and acidified, respectively. Adsorption efficiencies were further tested on real aqueous wastewater samples, and removal of Hg(II) was recorded as 69.6 % for biomass acidified and 76.3 % for biomass in nature. Results obtained from sorption experiments on real aqueous wastewater samples revealed that recovery of the target metal ions was very satisfactory. The pseudo-second-order model showed the best correlation to the experimental data. The current findings showed that the investigated materials are potential adsorbents for mercury(II) ion removal in aqueous solution, with acidified P. aquatica Aubl being the most efficient adsorbent.

Evaluation of optimal conditions for determination of low selenium content in shellfish samples collected at Todos os Santos Bay, Bahia, Brazil using HG-AFS.

This work proposes a procedure for the determination of total selenium content in shellfish after digestion of samples in block using cold finger system and detection using atomic fluorescent spectrometry coupled hydride generation (HG AFS). The optimal conditions for HG such as effect and volume of prereduction KBr 10 % (m/v) (1.0 and 2.0 ml) and concentration of hydrochloric acid (3.0 and 6.0 mol L(-1)) were evaluated. The best results were obtained using 3 mL of HCl (6 mol L(-1)) and 1 mL of KBr 10 % (m/v), followed by 30 min of prereduction for the volume of 1 mL of the digested sample. The precision and accuracy were assessed by the analysis of the Certified Reference Material NIST 1566b. Under the optimized conditions, the detection and quantification limits were 6.06 and 21.21 µg kg(-1), respectively. The developed method was applied to samples of shellfish (oysters, clams, and mussels) collected at Todos os Santos Bay, Bahia, Brazil. Selenium concentrations ranged from 0.23 ± 0.02 to 3.70 ± 0.27 mg kg(-1) for Mytella guyanensis and Anomalocardia brasiliana, respectively. The developed method proved to be accurate, precise, cheap, fast, and could be used for monitoring Se in shellfish samples.

A novel replication initiation region encoded in a widespread Acinetobacter plasmid lineage carrying a blaNDM-1 gene.

The blaNDM-1 gene and its variants encode metallo-beta-lactamases that confer resistance to almost all beta-lactam antibiotics. Genes encoding blaNDM-1 and its variants can be found in several Acinetobacter species, and they are usually linked to two different plasmid clades. The plasmids in one of these clades contain a gene encoding a Rep protein of the Rep_3 superfamily. The other clade consists of medium-sized plasmids in which the gene (s) involved in plasmid replication initiation (rep)have not yet been identified. In the present study, we identified the minimal replication region of a blaNDM-1-carrying plasmid of Acinetobacter haemolyticus AN54 (pAhaeAN54e), a member of this second clade. This region of 834 paired bases encodes three small peptides, all of which have roles in plasmid maintenance. The plasmids containing this minimal replication region are closely related; almost all contain blaNDM genes, and they are found in multiple Acinetobacter species, including A. baumannii. None of these plasmids contain an annotated Rep gene, suggesting that their replication relies on the minimal replication region that they share with the plasmid pAhaeAN54e. These observations suggest that this plasmid lineage plays a crucial role in the dissemination of the blaNDM-1 gene and its variants.

PhyloString: A web server designed to identify, visualize, and evaluate functional relationships between orthologous protein groups across different phylogenetic lineages.

Proteins are biological units whose essence is defined by their functional relationships with other proteins or biomolecules such as RNA, DNA, lipids, or carbohydrates. These functions encompass enzymatic, structural, regulatory, or physical interaction roles. The STRING database (Nucleic Acids Research, 8 Jan 2021;49(D1): D605-12) provides an index that defines the functional interaction networks between proteins in model organisms. To facilitate the identification, visualization, and evaluation of potential functional networks across organisms from different phylogenetic lineages, we have developed PhyloString (https://biocomputo.ibt.unam.mx/phylostring/), a web server that utilizes the indices of the STRING database. PhyloString decomposes these functional networks into modules, representing cohesive units of proteins grouped based on their similarity of STRING values and the phylogenetic origins of their respective organisms. This study presents and thoroughly discusses examples of such functional networks and their modules identified using PhyloString.

The effect of the genomic GC content bias of prokaryotic organisms on the secondary structures of their proteins.

One of the main characteristics of prokaryotic genomes is the ratio in which guanine-cytosine bases are used in their DNA sequences. This is known as the genomic GC content and varies widely, from values below 20% to values greater than 74%. It has been demonstrated that the genomic GC content varies in accordance with the phylogenetic distribution of organisms and influences the amino acid composition of their corresponding proteomes. This bias is particularly important for amino acids that are coded by GC content-rich codons such as alanine, glycine, and proline, as well as amino acids that are coded by AT-rich codons, such as lysine, asparagine, and isoleucine. In our study, we extend these results by considering the effect of the genomic GC content on the secondary structure of proteins. On a set of 192 representative prokaryotic genomes and proteome sequences, we identified through a bioinformatic study that the composition of the secondary structures of the proteomes varies in relation to the genomic GC content; random coils increase as the genomic GC content increases, while alpha-helices and beta-sheets present an inverse relationship. In addition, we found that the tendency of an amino acid to form part of a secondary structure of proteins is not ubiquitous, as previously expected, but varies according to the genomic GC content. Finally, we discovered that for some specific groups of orthologous proteins, the GC content of genes biases the composition of secondary structures of the proteins for which they code.

[Loeffler's endocarditis--a case report]. / Endomiocardite de Löffler--a propósito de um caso clínico.

Loeffler's endocarditis is an acute form of primary restrictive cardiomyopathy. We report the case of a young woman with pleuritic chest pain associated with fever and hypereosinophilia. She was hospitalized with suspected acute myopericarditis and was treated with aspirin, leading to clinical improvement. Ten days after discharge, she was rehospitalized due to recurrence of chest pain. The echocardiogram showed what appeared to be a mass filling the apex of the right ventricle (RV). She was referred for magnetic resonance imaging, which revealed marked myocardial thickening in the apex of the RV. The patient underwent an endomyocardial biopsy, resulting in a diagnosis of eosinophilic endocarditis. After treatment with prednisolone, all symptoms and the eosinophilia disappeared, and there was complete remission of the RV abnormalities. After three years of follow-up, the patient remains asymptomatic. This case shows that, even without an etiologic diagnosis of eosinophilia, the prognosis for Loeffler's endocarditis can be favorable if treatment is initiated early.

[Fulminant myocarditis]. / Miocardite fulminante - a propósito de um caso clínico.

A 46-year-old woman was admitted due to diplopia because of ophthalmoplegia, which improved with corticosteroid therapy. Eight days later, she was admitted with fulminant myocarditis in cardiogenic shock, with severe left ventricular dysfunction and frequent episodes of nonsustained ventricular tachycardia. As there was no clinical improvement, an endomyocardial biopsy was performed that revealed inflammatory infiltrate, vasculitis, and PCR positive for cytomegalovirus, Epstein-Barr virus, parvovirus B19 and enterovirus. Left ventricular function recovered with heart failure treatment and corticosteroids. Three months later, after progressive withdrawal of prednisolone, there was recurrence of myocarditis and left ventricular dysfunction, which was successfully treated by restarting corticosteroid therapy. One month later she was readmitted with fulminant myocarditis which again responded to steroids. She intermittently presented cutaneous purpura lesions. At this time the provisional diagnosis was vasculitis and she started monthly cycles of cyclophosphamide. Before the second cycle she was admitted with pneumonia and ventricular dysfunction and died.

Implementation of a pre-hospital network favoring primary angioplasty in STEMI to reduce mortality: the Algarve Project.

OBJECTIVE: To analyze the impact of reperfusion by either primary percutaneous coronary intervention (PPCI) or fibrinolysis, and mortality rates of a pre-hospital fast-track network for treating patients with ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: A pre-hospital network for STEMI patients, designated the Green Lane for Acute Myocardial Infarction (GL-AMI), has been implemented in the southern region of Portugal --the Algarve Project. We performed an observational study based on a prospective registry of 1338 patients admitted to Faro Hospital between 2004 and 2009, classified in two groups according to the method of admission: emergency department group (EDG) and GL-AMI group (GLG). More patients from GLG were reperfused (p < 0.0001). PPCI was the preferred method of reperfusion, 73.1% in GLG and 45.3% in EDG. Time delays were significantly shorter in GLG, except for pre-hospital delay: pre-hospital delay (p = 0.11); door-to-needle (p < 0.0001); door-to-balloon (p < 0.0001); and delay between symptoms and reperfusion (p < 0.0001). In-hospital mortality (4.3% vs 9.2%, p = 0.0007) and 6-month mortality (6.3% vs 13.8%, p < 0.0001) were significantly lower in GLG. CONCLUSIONS: The Algarve Project significantly reduced the time delay between onset of symptoms and reperfusion, significantly increased the rate of reperfusion, and significantly reduced in-hospital and six-month mortality.

Applying the perturbative integral in aeromaneuvers around Mars to calculate the cost.

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.