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A series of ruthenium complexes of formulae [RuCl(triazenide)(p-cymene)] have been synthesized using as ligand a triazenide monofunctionalized with an N-heterocyclic moiety. Nuclear magnetic resonance, high resolution mass spectrometry and X-ray diffraction were used to characterize the triazenide ligands and their complexes. In addition, these ruthenium complexes catalyzed the reduction of nitrobenzene to aniline in the presence of sodium borohydride and ethanol as solvent at room temperature. Notably, complex 5 was especially active in the reduction of nitroarenes substituted at the aromatic ring with electron-withdrawing or electron-donating fuctional groups affording the desired arylamines in good to excellent yields (80-100%). The role of the N-heterocyclic moiety on catalysis was explored.
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Similar to other insular birds around the world, the Galapagos rail (Laterallus spilonota Gould, 1841) exhibits reduced flight capacity following its colonization of the archipelago ~1.2 mya. Despite their short evolutionary history, rails have colonized seven different islands spanning the entire width of the archipelago. Galapagos rails were once common on islands with sufficiently high altitudes to support shrubs in humid habitats. After humans introduced goats, this habitat was severely reduced due to overgrazing. Habitat loss devastated some rail populations, with less than 50 individuals surviving, rendering the genetic diversity of Galapagos rail a pressing conservation concern. Additionally, one enigma is the reappearance of rails on the island of Pinta after they were considered extirpated. Our approach was to investigate the evolutionary history and geographic distribution of Galapagos rails as well as examine the genome-wide effects of historical population bottlenecks using 39 whole genomes across different island populations. We recovered an early divergence of rail ancestors leading to the isolated populations on Pinta and a second clade comprising the rest of the islands, historically forming a single landmass. Subsequently, the separation of the landmass ~900 kya may have led to the isolation of the Isabela population with more panmictic populations found on Santa Cruz and Santiago islands. We found that rails genomes contain long runs of homozygosity (>2 Mb) that could be related to the introduction of goats. Finally, our findings show that the modern eradication of goats was critical to avoiding episodes of inbreeding in most populations.
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Variação Genética , Genética Populacional , Cabras , Animais , Cabras/genética , Equador , Ecossistema , Ilhas , Filogenia , Conservação dos Recursos Naturais , Sequenciamento Completo do GenomaRESUMO
BACKGROUND: The elaboration of biocompatible nerve guide conduits (NGCs) has been studied in recent years as a treatment for total nerve rupture lesions (axonotmesis). Different natural polymers have been used in these studies, including cellulose associated with soy protein. The purpose of this report was to describe manufacturing NGCs suitable for nerve regeneration using the method of dip coating and evaporation of solvent with cellulose acetate (CA) functionalized with soy protein acid hydrolysate (SPAH). METHODS: The manufacturing method and bacterial control precautions for the CA/SPAH NGCs were described. The structure of the NGCs was analyzed under a scanning electron microscope (SEM); porosity was analyzed with a degassing method using a porosimeter. Schwann cell (SCL 4.1/F7) biocompatibility of cell-seeded nerve guide conduits was evaluated with the MTT assay. RESULTS: The method employed allowed an easy elaboration and customization of NGCs, free of bacteria, with pores in the internal surface, and the uniform wall thickness allowed manipulation, which showed flexibility; additionally, the sample was suturable. The NGCs showed initial biocompatibility with Schwann cells, revealing cells adhered to the NGC structure after 5 days. CONCLUSIONS: The fabricated CA/SPAH NGCs showed adequate features to be used for peripheral nerve regeneration studies. Future reports are necessary to discuss the ideal concentration of CA and SPAH and the mechanical and physicochemical properties of this biomaterial.
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Formation of liquid condensates plays a critical role in biology via localization of different components or via altered hydrodynamic transport, yet the hydrogen-bonding environment within condensates, pivotal for solvation, has remained elusive. We explore the hydrogen-bond dynamics within condensates formed by the low-complexity domain of the fused in sarcoma protein. Probing the hydrogen-bond dynamics sensed by condensate proteins using two-dimensional infrared spectroscopy of the protein amide I vibrations, we find that frequency-frequency correlations of the amide I vibration decay on a picosecond time scale. Interestingly, these dynamics are markedly slower for proteins in the condensate than in a homogeneous protein solution, indicative of different hydration dynamics. All-atom molecular dynamics simulations confirm that lifetimes of hydrogen-bonds between water and the protein are longer in the condensates than in the protein in solution. Altered hydrogen-bonding dynamics may contribute to unique solvation and reaction dynamics in such condensates.
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Sarcoma , Humanos , Proteínas , Amidas , HidrogênioRESUMO
Introduction: The hepatitis C virus (HCV) is responsible for 1.5 million new infections, and around 290 thousand deaths worldwide. 15 to 30% of the patients that go into a chronic phase of the disease will develop cirrhosis or hepatocellular carcinoma within 20 years and is the leading etiology for liver transplantation. HCV genetic characteristics display a remarkable genetic diversity, which divides HCV into 8 genotypes and 67 subgenotypes; the treatment and probability of chronic HCV depend on these genotypes and subgenotypes. In Ecuador, there is no available information regarding HCV genotypes and subgenotypes; therefore, this study aims to provide an overview of the main genotypes circulating in Ecuador. Methods: In a cross-sectional and descriptive study using the Ecuadorian Ministry of Health (MSP) registry of patients already diagnosed with Hepatitis C (HCV) between 2017 and 2019. From 51 patients identified by health ministry, blood samples from a total of 15 subjects (named HCV1 to HCV15) were collected using an appropriate venipuncture technique. Pandemic-related circumstances avoid reaching all patients identified by health ministry. Results: After the amplification of 11 samples from patients living in the Ecuadorian territory, the genotypes of HCV obtained were distributed as follows: 6 samples corresponding to subgenotype 2b (54.5%), 2 samples corresponding to subgenotype 1a (18.2%), 2 samples corresponding to subgenotype 4d (18.2%) and 1 corresponding to sample 1b (9.1%). Conclusion: These results represent the first epidemiological approach to genotype distribution in Ecuador, and it contributes to better management of patients. We emphasize the importance of the development of better strategies from the Healthcare Ministry of Ecuador (MSP) for the identification, treatment and tracking of HCV patients.
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Background: Carbapenem-resistant Klebsiella pneumoniae, particularly isolates classified as sequence-type 258 (ST258), are multidrug-resistant strains that are strongly associated with poor-prognosis nosocomial infections, as current therapeutic options are limited and ineffective. In recent years, phage therapy has emerged as a promising treatment option for these scenarios. Methodology and Results: We report the isolation and characterization of three new phages against Klebsiella pneumoniae ST258 strains recovered from Machángara river wastewater. These new members of the Ackermannviridae family showed stability over a wide temperature and pH range and burst sizes ranging from 6 to 44 plaque-forming units per bacteria. Their genomes were about 157 kilobases, with an average guanine-cytosine content of 46.4% and showed presence of several transfer RNAs, which also allowed us to predict in silico a lytic replicative cycle due to the presence of endolysins and lysozymes. Conclusion: Three lytic phages of Ackermannviridae family were recovered against Klebsiella pneumoniae ST258 strains from sewage; however, further characterization is needed for future consideration as therapeutic alternatives.
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In its natural distribution, Araucaria araucana is a plant species usually exposed to extreme environmental constraints such as wind, volcanism, fires, and low rainfall. This plant is subjected to long periods of drought, accentuated by the current climate emergency, causing plant death, especially in its early growth stages. Understanding the benefits that both arbuscular mycorrhizal fungi (AMF) and endophytic fungi (EF) could provide plants under different water regimes would generate inputs to address the above-mentioned issues. Here, the effect of AMF and EF inoculation (individually and combined) on the morphophysiological variables of A. araucana seedlings subjected to different water regimes was evaluated. Both the AMF and EF inocula were obtained from A. araucana roots growing in natural conditions. The inoculated seedlings were kept for 5 months under standard greenhouse conditions and subsequently subjected to three different irrigation levels for 2 months: 100, 75, and 25% of field capacity (FC). Morphophysiological variables were evaluated over time. Applying AMF and EF + AMF yielded a noticeable survival rate in the most extreme drought conditions (25% FC). Moreover, both the AMF and the EF + AMF treatments promoted an increase in height growth between 6.1 and 16.1%, in the production of aerial biomass between 54.3 and 62.6%, and in root biomass between 42.5 and 65.4%. These treatments also kept the maximum quantum efficiency of PSII (Fv/Fm 0.71 for AMF and 0.64 for EF + AMF) stable, as well as high foliar water content (>60%) and stable CO2 assimilation under drought stress. In addition, the EF + AMF treatment at 25% FC increased the total chlorophyll content. In conclusion, using indigenous strains of AMF, alone or in combination with EF, is a beneficial strategy to produce A. araucana seedlings with an enhanced ability to tolerate prolonged drought periods, which could be of great relevance for the survival of these native species under the current climate change.
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Prosopis laevigata (mesquite; Fabaceae) forms fertility islands in soils of semi-arid lands where microbial diversity concentrates in response to the accumulation of resources in the soil beneath individual plants, promoting organic matter decomposition and nutrient cycling. This phenomenon provides suitable conditions for the proliferation of key edaphic elements such as fungi and mites. Mite-fungal interactions are central for our understanding of nutrient cycling processes in resource-limited arid food webs; yet, no information is available about fertility islands in semi-arid lands. Thus, we aimed to determine in vitro fungal-based feeding preferences and molecular gut content of the oribatid mite species Zygoribatula cf. floridana and Scheloribates cf. laevigatus, which are abundant under the canopy of P. laevigata in an intertropical semi-arid zone in Central Mexico. Our results on the gut content analysis of these oribatid species resulted in the ITS-based identification of the following fungi: Aspergillus homomorphus, Beauveria bassiana, Filobasidium sp., Mortierella sp., Roussoella sp., Saccharomyces cerevisiae, Sclerotiniaceae sp. and Triparticalcar sp. Furthermore, under laboratory conditions both oribatid mite species exhibited feeding preferences on melanized fungi, such as Cladosporium spp., whereas A. homomorphus and Fusarium penzigi were avoided. Our findings indicated that the analyzed oribatid mite species have similar feeding preferences for melanized fungi, which might suggest resource partitioning and a degree of preference, explaining the coexistence of both oribatid species.
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Fabaceae , Ácaros , Prosopis , Animais , Cadeia Alimentar , Fertilidade , SoloRESUMO
The research interest of the scientific community in biofilm-forming microorganisms is growing due to the problems caused by their infections affecting humans and animals, mainly because of the difficulty of the host immune system in eradicating these microbial complex communities and the increasing antimicrobial resistance rates worldwide. This review describes the virulence factors and their interaction with the microbial communities of four well-known and highly biofilm-forming pathogens, more exactly, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus spp., and Candida spp. The innate and adaptive immune responses caused by the infection with these microorganisms and their evasion to the host immune system by biofilm formation are discussed in the present work. The relevance of the differences in the expression of certain virulence factors and the immune response in biofilm-associated infections when compared to planktonic infections is usually described as the biofilm architecture protects the pathogen and alters the host immune responses, here we extensively discussed these mechanisms.
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In Northwestern Patagonia (Chile), three species of Morchella from undisturbed environments have been identified to date: Morchella tridentina, Morchella andinensis and Morchella aysenina, all belonging to the Elata clade and associated mainly with Nothofagus forests. In this study, the search for Morchella specimens was extended to disturbed environments in Central-Southern Chile, to further explore Morchella species diversity in the country, which is still very limited. The Morchella specimens were identified through multilocus sequences analysis, and the mycelial cultures were characterized, establishing comparisons with specimens from undisturbed environments. To the best of our knowledge, these results reveal for the first time in Chile the presence of the species Morchella eximia and Morchella importuna, and in the case of the last one also the first record in South America. These species were found associated almost exclusively with harvested or burned coniferous plantations. The in vitro mycelial characterization revealed certain inter- and intra-specific patterns of the morphology, such as pigmentation, mycelium type, and development and formation of sclerotia, which varied according to growth media and incubation temperature. The growth rates (mm/day) and mycelial biomass (mg) were significantly influenced by the temperature (p < 0.05), with maximum rates (>10 mm/day) and biomass (approx. 20 mg) between 20 and 24 °C, while a significant growth reduction (70-90%) was observed at 28 °C, mainly in the species from undisturbed environments. Potato-dextrose (PDA) medium stimulated the greatest mycelial density and sclerotia formation in most of the isolates, mainly in M. eximia (UDEC-LAF 236 isolate) which recorded the best mycelial growth performance. Among isolates, UDEC-LAF 236 also showed the best performance in sclerotia production (>350 sclerotia/dish) in 10 days of growth. This study contributes to the knowledge of the diversity of Morchella species in Chile by broadening the species range to those from disturbed environments. It also provides molecular and morphological characterization of the in vitro cultures of different Morchella species. The report on M. eximia and M. importuna, species known as cultivable, adapted to local climatic and edaphic conditions could represent the first step to developing artificial Morchella cultivation methods in Chile.
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Micélio , ChileRESUMO
We examined armadillos from museum collections in the United States using molecular assays to detect leprosy-causing bacilli. We found Mycobacterium leprae bacilli in samples from the United States, Bolivia, and Paraguay; prevalence was 14.8% in nine-banded armadillos. US isolates belonged to subtype 3I-2, suggesting long-term circulation of this genotype.
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Hanseníase , Mycobacterium leprae , Humanos , Estados Unidos , Animais , Tatus/microbiologia , Hanseníase/microbiologia , Museus , GenótipoRESUMO
The high prevalence of nosocomial infections is related to the use of medical insertion devices such as central venous catheters (CVCs). Most of the microorganisms causing nosocomial infections are biofilm producers, this characteristic allows them to adhere to abiotic surfaces and cause initial catheter infections that can lead to bloodstream infections. Our main goal in this systematic review was to evaluate the prevalence of biofilm among CVC-related infections, particularly among Intensive Care Unit (ICU) patients, in the studies applying different in vitro and in vivo methodologies. All studies reporting clinical isolates from patients with catheter-related nosocomial infections and biofilm evaluation published up to 24 June 2022 in the PubMed and Scopus databases were included. Twenty-five studies met the eligibility criteria and were included in this systematic review for analysis. Different methodologies were applied in the assessment of biofilm-forming microorganisms including in vitro assays, catheter-infected in vitro, and in vivo mouse models. The present study showed that between 59 and 100% of clinical isolates were able to form biofilms, and the prevalence rate of biofilm formation varied significantly between studies from different countries and regions. Among the clinical isolates collected in our study set, a wide variety of microorganisms including Gram-positive strains, Gram-negative strains, and Candida albicans were found. Many authors studied resistance mechanisms and genes related to biofilm development and surface adherence properties. In some cases, the studies also evaluated biofilm inhibition assays using various kinds of catheter coatings.
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Faced with the convergence of economic, social, political and environmental crises, the importance of the public sector has been rediscovered on a global scale. The article offers a review of the evolution of political and academic debates on public ownership in general and public services provision in particular over the last decades, with emphasis on the energy sector. Taking as a temporal and analytical reference the research and advocacy work developed by the authors and other scholar-activists based at the Transnational Institute from 2006 to the present, the article summarizes the main issues currently in the spotlight and highlights gaps in knowledge and points of contention. It also suggests elements for future research and campaign agendas around public ownership in different regions of the world.
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Melatonin (MEL), an indolamine with diverse functions in the brain, has been shown to produce antidepressant-like effects, presumably through stimulating neurogenesis. We recently showed that the combination of MEL with ketamine (KET), an NMDA receptor antagonist, has robust antidepressant-like effects in mice, at doses that, by themselves, are non-effective and have no adverse effects. Here, we show that the KET/MEL combination increases neurogenesis in a clone derived from human olfactory neuronal precursors, a translational pre-clinical model for effects in the human CNS. Neurogenesis was assessed by the formation of cell clusters > 50 µm in diameter, positively stained for nestin, doublecortin, BrdU and Ki67, markers of progenitor cells, neurogenesis, and proliferation. FGF, EGF and BDNF growth factors increased the number of cell clusters in cultured, cloned ONPs. Similarly, KET or MEL increased the number of clusters in a dose-dependent manner. The KET/MEL combination further increased the formation of clusters, with a maximal effect obtained after a triple administration schedule. Our results show that the combination of KET/MEL, at subeffective doses that do not produce adverse effects, stimulate neurogenesis in human neuronal precursors. Moreover, the mechanism by which the combination elicits neurogenesis is meditated by melatonin receptors, CaM Kinase II and CaM antagonism. This could have clinical advantages for the fast treatment of depression.
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Ketamina , Melatonina , Animais , Antidepressivos/metabolismo , Antidepressivos/farmacologia , Hipocampo/metabolismo , Humanos , Ketamina/metabolismo , Ketamina/farmacologia , Melatonina/metabolismo , Melatonina/farmacologia , Camundongos , Neurogênese , NeurôniosRESUMO
The remarkable radiation of South American (SA) canids produced 10 extant species distributed across diverse habitats, including disparate forms such as the short-legged, hypercarnivorous bush dog and the long-legged, largely frugivorous maned wolf. Despite considerable research spanning nearly two centuries, many aspects of their evolutionary history remain unknown. Here, we analyzed 31 whole genomes encompassing all extant SA canid species to assess phylogenetic relationships, interspecific hybridization, historical demography, current genetic diversity, and the molecular bases of adaptations in the bush dog and maned wolf. We found that SA canids originated from a single ancestor that colonized South America 3.9 to 3.5 Mya, followed by diversification east of the Andes and then a single colonization event and radiation of Lycalopex species west of the Andes. We detected extensive historical gene flow between recently diverged lineages and observed distinct patterns of genomic diversity and demographic history in SA canids, likely induced by past climatic cycles compounded by human-induced population declines. Genome-wide scans of selection showed that disparate limb proportions in the bush dog and maned wolf may derive from mutations in genes regulating chondrocyte proliferation and enlargement. Further, frugivory in the maned wolf may have been enabled by variants in genes associated with energy intake from short-chain fatty acids. In contrast, unique genetic variants detected in the bush dog may underlie interdigital webbing and dental adaptations for hypercarnivory. Our analyses shed light on the evolution of a unique carnivoran radiation and how it was shaped by South American topography and climate change.
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Adaptação Fisiológica , Canidae , Filogenia , Adaptação Fisiológica/genética , Animais , Canidae/classificação , Canidae/genética , Demografia , Variação Genética , Genômica , América do SulRESUMO
Capacitive-resistive energy transfer therapy (CRet) is used to improve the rehabilitation of different injuries. This study aimed to evaluate and compare the changes in temperature and current flow during different CRet applications on upper and lower molars and incisors, with and without implants, on ten cryopreserved corpses. Temperatures were taken on molars and incisors with invasive devices and skin temperature was taken with a digital thermometer at the beginning and after treatments. Four interventions: 15 VA capacitive hypothermic (CAPH), 8 watts resistive (RES8), 20 watts resistive (RES20) and 75 VA capacitive (CAP75) were performed for 5 min each. All treatments in this study generated current flow (more than 0.00005 A/m2) and did not generate a significant temperature increase (p > 0.05). However, RES20 application slightly increased surface temperature on incisors without implants (p = 0.010), and molar with (p = 0.001) and without implant (p = 0.008). Also, CAP75 application increased surface temperature on molars with implant (p = 0.002) and upper incisor with implant (p = 0.001). In conclusion, RES8 and CAPH applications seem to be the best options to achieve current flow without an increase in temperature on molars and incisors with and without implants.
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Incisivo , Dente Molar , Cadáver , Transferência de Energia , HumanosRESUMO
BACKGROUND: Evidence suggests that tibialis posterior muscle plays an important role in equinovarus foot deformity in patients who had suffered a stroke and it is one of the most frequently injected lower-extremity muscles for the management of spasticity. Our aim was to assess if a needle accurately and safely penetrates the tibialis posterior muscle during the application of dry needling. METHODS : We conducted a cadaveric descriptive study. Needling insertion of the tibialis posterior was conducted in 11 cryopreserved cadavers with a 70 mm needle. The needle was inserted using two common approaches, at midpoint (posterior/medial approach) and at upper third (anterior approach) of the leg towards the tibialis posterior. The needle was advanced into the tibialis posterior based upon clinician judgement. Cross-sectional anatomical dissections were photographed and analyzed by photometry. Safety was assessed by calculating the distances from the tip and the path of the needle to proximate neurovascular structures. RESULTS: Accurate needle penetration of the tibialis posterior muscle was observed in all cadavers with both approaches. In general, distances from the needle to the neurovascular bundles were larger with the posterior/medial approach than with the anterior approach, reaching statistically significance for needle tip to nerve (mean difference: 0.6 cm, 95%CI 0.35 to 0.85 cm) and vascular bundle (mean difference: 0.55 cm, 95%CI 0.3 to 0.8 cm) distances (P < 0.001) and needle path to vascular bundle distance (difference: 0.25 cm, 95%CI 0.1 to 0.4 cm, P = 0.045). Age and gender did not influence the main results. CONCLUSIONS: This cadaveric study suggests that needling of the tibialis posterior muscle can be accurately and safely conducted. Safety seems to be larger with the posterior/medial approach when compared with the anterior approach.
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Agulhamento Seco , Perna (Membro) , Cadáver , Estudos Transversais , Humanos , Músculo EsqueléticoRESUMO
We report herein the synthesis and application of enantiopure C2 -symmetric primary amine-1,3-bis-thiourea organocatalysts in enantioselective conjugate 1,4-Michael addition of carbonyl containing nucleophiles, to nitroalkenes and N-phenylmaleimide, leading to final products in good enantioselectivities (up to 99%) and yields (up to 99%). We propose supramolecular noncovalent interactions within the organocatalyst's cleft between the substrate and the catalyst, via hydrogen bonding. Supramolecular interaction thus lowers the transition state energy mimicking an enzyme. Mechanism underlying our experimental results is supported by theorical calculations.
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Alcenos , Tioureia , Alcenos/química , Catálise , Nitrocompostos/química , Estereoisomerismo , Tioureia/químicaRESUMO
BACKGROUND: The wind tunnel is a compression cabin through which a stream of air rises homogeneously, generated by fans. To perform different acrobatics, indoor skydivers have to change their body position by turning their body and orientation in reference to the space. Thus, the vestibular, visual and somatosensory systems are subjected to multiple disturbances. Postural control could be affected by altering the visual, vestibular and somatosensory systems during indoor skydiving in the wind tunnel. The aim of this study is to describe the influence of a standard wind tunnel training session on postural control in a normal gravitational situation in indoor skydiving. METHODS: Ten indoor skydivers registered with the Royal Spanish Aeronautical Federation, who had participated in national or international competitions one year ago, were recruited. A single 30 min training session was performed. Postural control was assessed through posturographic analysis using a stabilometric platform immediately before and after the training session. The variables studied were related to the relative position and length of the centre of pressure. RESULTS: No statistically significant changes were found between the initial and final assessment for the posturographic variables studied. CONCLUSIONS: No differences in postural control were found after a standard wind tunnel training session in indoor competition skydivers.
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Aviação , Equilíbrio Postural , Estudos Transversais , Postura , Modalidades de FisioterapiaRESUMO
During the COVID-19 pandemic, the use of masks has been recommended as a containment measure. The mask is a hindrance to normal breathing that causes discomfort. This could put more work on the respiratory accessory muscles, and, consequently, these muscles could see their tone increase. For this reason, during this clinical trial (registered in clincaltrials.gov, number: NCT04789603), it was observed whether the use of the mask produced changes in the distance traveled, in the heart rate, in the oxygenometry, in the self-perceived dyspnea and in the tone of accessory respiratory muscles during a 6-min walk test (6MWT). Fifty healthy volunteers were recruited and carried out the 6MWT on three occasions. They carried out the 6MWT in various situations: using an FFP2/N95 mask, using a surgical mask, and without using a mask. The distance walked, the heart rate, the oxygen therapy, the tone of the accessory respiratory muscles, and the self-perceived dyspnea were recorded in each situation. Significant differences were found between the three situations in terms of self-perceived dyspnea FFP2/N95 > surgical mask > no mask. However, there are no differences between the experimental situations during the 6MWT in terms of distance travelled, heart rate, oxygenometry or respiratory muscle tone.