Five million years of Antarctic Circumpolar Current strength variability.

The Antarctic Circumpolar Current (ACC) represents the world's largest ocean-current system and affects global ocean circulation, climate and Antarctic ice-sheet stability1-3. Today, ACC dynamics are controlled by atmospheric forcing, oceanic density gradients and eddy activity4. Whereas palaeoceanographic reconstructions exhibit regional heterogeneity in ACC position and strength over Pleistocene glacial-interglacial cycles5-8, the long-term evolution of the ACC is poorly known. Here we document changes in ACC strength from sediment cores in the Pacific Southern Ocean. We find no linear long-term trend in ACC flow since 5.3 million years ago (Ma), in contrast to global cooling9 and increasing global ice volume10. Instead, we observe a reversal on a million-year timescale, from increasing ACC strength during Pliocene global cooling to a subsequent decrease with further Early Pleistocene cooling. This shift in the ACC regime coincided with a Southern Ocean reconfiguration that altered the sensitivity of the ACC to atmospheric and oceanic forcings11-13. We find ACC strength changes to be closely linked to 400,000-year eccentricity cycles, probably originating from modulation of precessional changes in the South Pacific jet stream linked to tropical Pacific temperature variability14. A persistent link between weaker ACC flow, equatorward-shifted opal deposition and reduced atmospheric CO2 during glacial periods first emerged during the Mid-Pleistocene Transition (MPT). The strongest ACC flow occurred during warmer-than-present intervals of the Plio-Pleistocene, providing evidence of potentially increasing ACC flow with future climate warming.

In Silico characterization of satellitomes and cross-amplification of putative satDNAs in two species of the Hypostomus ancistroides complex (Siluriformes, Loricariidae).

Introduction The mapping of the satellite DNA on chromosomes is vital to understanding the distribution and evolution of repetitions in the genome since these chromosomal studies have shown the origin, evolutionary mode, and function of repetitive sequences. This study aimed to prospect the satellitome and determine its location in the genome of two cryptic species of Hypostomus, H. aff. ancistroides and H. ancistroides, with and without XX/XY sexual chromosome system. Methods Mitotic chromosomes and DNA extraction were obtained according to protocols. After the whole genome sequencing, the satDNAs were retrieved, amplified, and hybridized in chromosome preparations for male and female individuals. Results We found 30 satellite families (47 variants, two superfamilies) in H. ancistroides and 38 satellite families (45 variants, four superfamilies) in H. aff. ancistroides. The sequences varied from 14bp to 2662bp in H. ancistroides and from 14bp to 2918bp in H. aff. ancistroides. We did not observe any tandem repeats that were exclusive to each of the libraries, however, many sequences showed very different abundances and copy numbers between the libraries. Four satDNAs did not hybridize on the chromosomes of either species. Conversely, one satDNA hybridized in both species, HxySat1-80. However, the phenotypes found varied among species, populations, and in the same individual. There was no sign of HanSat3-464 and HanSat11-335 in any individuals of H. aff. ancistroides, but markings were in chromosomes of H. ancistroides. HxySat12-1127 and HxySat8-52, on the other hand, were only hybridized in H. aff. ancistroides, while H. ancistroides had a negative sign. No hybridization of satDNAs was found in the X and Y sex chromosomes, as they were mostly composed of euchromatin. Conclusion We distinguish H. aff. ancistroides as genetically different from H. ancistroides, recognizing that such characteristics go far beyond morphological, karyotypic, and molecular data. Our data support the differential abundance and location of satellite DNAs and confirm that many organisms, including fish, have repetitive sequences that validate the library hypothesis. All found and validated satDNAs and the characterization of the satelitomes of the two species represent important contributions to cytogenomic studies of the genus Hypostomus.

Neuroregeneration and immune response after neurorrhaphy are improved with the use of heterologous fibrin biopolymer in addition to suture repair alone.

INTRODUCTION/AIMS: Peripheral nerve injuries result in impaired neuromuscular interactions, leading to morphological and functional alterations. Adjuvant suture repair methods have been used to improve nerve regeneration and modulate the immune response. Heterologous fibrin biopolymer (HFB), a scaffold with adhesive properties, plays a critical role in tissue repair. The aim of this study is to evaluate neuroregeneration and immune response focusing on neuromuscular recovery, using suture-associated HFB for sciatic nerve repair. METHODS: Forty adult male Wistar rats were distributed into four groups (n = 10): C (control), only sciatic nerve location; D (denervated), neurotmesis and 6-mm gap removal and fixation stumps in subcutaneous tissue; S (suture), neurotmesis followed by suture; and SB (suture + HFB), neurotmesis followed by suture and HFB. Analysis of M2 macrophages (CD206+ ), as well as the morphology and morphometry of nerves, soleus muscle, and neuromuscular junctions (NMJs), were performed at 7 and 30 days after surgery. RESULTS: The SB group had the highest M2 macrophage area in both periods. After 7 days, SB was the only group similar to the C group regarding the number of axons; furthermore, after 30 days, the SB group was closer to the C group concerning blood vessel and central myonuclear numbers, NMJ angle, and connective tissue volume. After 7 days, increases in nerve area, as well as the number and area of blood vessels, were also observed in SB. DISCUSSION: HFB potentiates the immune response, increases axonal regeneration, induces angiogenesis, prevents severe muscle degeneration, and assists in NMJ recovery. In conclusion, suture-associated HFB has major implications for improved peripheral nerve repair.

Headache and systemic lupus erythematosus: A narrative review.

OBJECTIVE: To review the epidemiology, the differential diagnosis, and the clinical and laboratory factors associated with the care management of headaches in patients with systemic lupus erythematosus (SLE). BACKGROUND: SLE is a chronic autoimmune disease and in 12%-95% of patients, the nervous system is involved. Headache is a frequently reported, although nonspecific, symptom that may potentially represent serious underlying diagnoses. Primary headaches may also occur in these patients, thereby causing a negative and significant impact on their quality of life. METHODS: This is a narrative review. A literature review was conducted on the PubMed platform using the following terms: (1) headache and (2) lupus. All articles considered relevant were included. No limitations were imposed for the publication date. RESULTS: Headache is a frequent symptom in patients with SLE. Although its prevalence is similar to the general population, headaches nonetheless tend to have a greater negative impact on these patients. Patients with SLE are more likely to experience headache due to vascular diseases such as cerebral venous sinus thrombosis, stroke, reversible cerebral vasoconstriction syndrome, posterior reversible encephalopathy syndrome, and vasculitis. Aseptic meningitis, neuroinfections, intracranial neoplasms, and intracranial hypertension or hypotension may also be a cause of headache in these patients. Although used in disease activity scores, the concept of lupus headache is controversial. CONCLUSIONS: Headache is a frequent symptom in patients with SLE. An appropriate approach enables the potentially serious conditions, which are the causes of secondary headaches, to be recognized and treated, together with an appropriate diagnosis and treatment of primary headaches.

Phylogeography and karyotypic evolution of some Deuterodon species from southeastern Brazil (Characiformes, Characidae, Stethaprioninae).

Deuterodon is a genus of the subfamily Stethaprioninae, a group of Neotropical fish known as tetras. Deuterodon hastatus represents a species complex, which is supported by cytogenetic and molecular data. In this study, we show the results of comparative evolutionary analyses of the ATP synthase subunit 6 gene in four Deuterodon species, in addition to ribosomal markers (18S rDNA and 5S rDNA), of a new population of the D. hastatus species complex from the Angra dos Reis/RJ region. The study population comprised a new cytotype, which we refer to as cytotype D, in D. hastatus, with 2n = 50 = 6M+8SM+8ST+28A. We obtained three different clades of D. hastatus in our phylogeny, one of them composed only by specimens of cytotype D. By using molecular clock dating, we observed that the radiation of Deuterodon from southeastern Brazil seemed to be associated with neotectonic events that occurred during the Miocene-Pliocene and Pliocene-Pleistocene transitions, marked by the capture of headwater streams and marine transgressions. The results obtained reinforce the idea that D. hastatus is a species complex, and at least three evolutionary significant units were identified in this group.

In silico and in vitro structure-stability-function relationship of analog peptides of Stigmurin and its antibacterial and antibiofilm activities.

Multidrug-resistant bacterial infections are a threat to public health worldwide, which boosts the urgent need for pharmacological research for new drugs. Although the peptides without disulfide bridges from scorpions have shown antimicrobial action, usually their toxicity hamper their pharmacological application. Stigmurin is a non-hemolytic cationic peptide from Tityus stigmurus venom with antibacterial effect and toxicity on normal cells. In this approach, the conformational changes and stability of two Stigmurin analog peptides, named StigA8 and StigA18, were evaluated by circular dichroism, as well as the mechanism of interaction with bacterial membranes in silico. In addition, the in vitro and in vivo antibacterial activity and the action against the biofilm formed by multidrug-resistant Staphylococcus aureus were investigated. StigA8 (+4) and StigA18 (+5) revealed the ability to change their structural conformation depending on the medium composition, and high stability at different temperatures and pH conditions. Both analog peptides showed greater ability to interact with bacterial membranes in silico when compared to the native one. StigA8 and StigA18 demonstrated low hemolytic action, with non-toxic effect on G. mellonella larvae up to 120 mg/kg. StigA8 and StigA18 presented a broad spectrum of antibacterial action in vitro, especially against multidrug-resistant clinical isolates. The analog peptides (7.5 µM) also reduced the biofilm biomass of multidrug-resistant S. aureus, as well as increased the larval survival of the Galleria mellonella infected larvae. Therefore, StigA8 and StigA18 showed a beneficial potential in the treatment of bacterial infections, constituting promising bioactive components for the development of new antimicrobial agents.

Intrauterine and Postnatal Exposure to High Levels of Fluoride Is Associated with Motor Impairments, Oxidative Stress, and Morphological Damage in the Cerebellum of Offspring Rats.

Fluoride (F) is abundantly present on Earth and plays a beneficial role in human health. However, exposure to high doses of F can be a risk, mainly in endemic fluorosis regions. In light of this, we investigated the effects of F exposure during the intrauterine and postnatal periods of rats, in doses similar to those recommended in drinking water and the levels of F in regions with endemic fluorosis, on the offspring rats' cerebellum. Pregnant rats were divided into three groups: control (received ultrapure water only), 10 mg F/L, and 50 mg F/L for a period of 42 days (21 days gestation and 21 days lactation). At the end of the lactation period, the male pups were evaluated by behavioral tests, morphological markers, and biochemistry assays. The results pointed out that 50 mg F/L exposure during the intrauterine and lactational period of rats is capable of promoting oxidative stress in the cerebellum with a decrease in Purkinje cell density and myelin basic protein compromise, which could be associated with functional motor impairments. In addition, although 10 mg F/L exposure promoted redox alterations, it did not affect other parameters evaluated, highlighting the safe use of F in low doses.

Binge-Like Exposure During Adolescence Induces Detrimental Effects in Alveolar Bone that Persist in Adulthood.

BACKGROUND: Alcohol (EtOH) intake during adolescence has become an important public health issue. Although the detrimental effects of EtOH intake on the musculoskeletal system are well known, only a few studies have investigated its impact on the stomatognathic system of adolescents. This study aimed to investigate the effect of EtOH binge drinking on the alveolar bone and the long-term consequences after abstinence. METHODS: Adolescent female Wistar rats (35 days old) were exposed to 4 cycles of EtOH binge drinking (3 g/kg/d; 3 days On-4 days Off) or distilled water (control group). Alveolar bone micromorphology and vertical bone distance were evaluated at 1, 30, and 60 days after that last EtOH intake through X-ray computed microtomography. The mineral:matrix ratio was assessed through Raman spectroscopy. RESULTS: A decrease in both trabecular thickness and volume ratio, and an increase in trabecular separation were observed at the 1-day evaluation (immediate withdrawal). After 30 and 60 days, the alveolar bone parameters were found similar to control, except for the mineral:matrix ratio in the long-term abstinence. CONCLUSIONS: EtOH binge drinking during adolescence results in alveolar bone damage that may persist in adulthood, even after abstinence.

Burning in southwestern Brazilian Amazonia, 2016-2019.

Fire is one of the most powerful modifiers of the Amazonian landscape and knowledge about its drivers is needed for planning control and suppression. A plethora of factors may play a role in the annual dynamics of fire frequency, spanning the biophysical, climatic, socioeconomic and institutional dimensions. To uncover the main forces currently at play, we investigated the area burned in both forested and deforested areas in the outstanding case of Brazil's state of Acre, in southwestern Amazonia. We mapped burn scars in already-deforested areas and intact forest based on satellite images from the Landsat series analyzed between 2016 and 2019. The mapped burnings in already-deforested areas totalled 550,251 ha. In addition, we mapped three forest fires totaling 34,084 ha. Fire and deforestation were highly correlated, and the latter occurred mainly in federal government lands, with protected areas showing unprecedented forest fire levels in 2019. These results indicate that Acre state is under increased fire risk even during average rainfall years. The record fires of 2019 may continue if Brazil's ongoing softening of environmental regulations and enforcement is maintained. Acre and other Amazonian states must act quickly to avoid an upsurge of social and economic losses in the coming years.

Structure-activity relationship study of antitrypanosomal chalcone derivatives using multivariate analysis.

Chagas disease represents one of several neglected diseases with a reduced number of chemotherapeutical drugs including the highly toxic compounds benznidazole and nifurtimox. In this sense, natural products represent an import scaffold for the discovery of new biologically active compounds, in which chalcones are promising representatives due to their antitrypanosomal potential. In this work, a series of 36 chalcone derivatives were synthesized and tested against trypomastigotes of Trypanosoma cruzi. In addition, a detailed investigation on their molecular features was performed. The obtained results suggest that certain molecular features are fundamental for an efficient antitrypanosomal potential of chalcones, such as allylic groups, α,ß-unsaturated carbonyl system, and aromatic hydroxyl groups. These results were obtained based on the interpretation of machine-learning and multivariate statistical methods, which revealed the essential characteristics of chalcone prototypes against trypomastigotes of T. cruzi.

Functional and regulatory conservation of the soybean ER stress-induced DCD/NRP-mediated cell death signaling in plants.

BACKGROUND: The developmental and cell death domain (DCD)-containing asparagine-rich proteins (NRPs) were first identified in soybean (Glycine max) as transducers of a cell death signal derived from prolonged endoplasmic reticulum (ER) stress, osmotic stress, drought or developmentally-programmed leaf senescence via the GmNAC81/GmNAC30/GmVPE signaling module. In spite of the relevance of the DCD/NRP-mediated signaling as a versatile adaptive response to multiple stresses, mechanistic knowledge of the pathway is lacking and the extent to which this pathway may operate in the plant kingdom has not been investigated. RESULTS: Here, we demonstrated that the DCD/NRP-mediated signaling also propagates a stress-induced cell death signal in other plant species with features of a programmed cell death (PCD) response. In silico analysis revealed that several plant genomes harbor conserved sequences of the pathway components, which share functional analogy with their soybean counterparts. We showed that GmNRPs, GmNAC81and VPE orthologs from Arabidopsis, designated as AtNRP-1, AtNRP-2, ANAC036 and gVPE, respectively, induced cell death when transiently expressed in N. benthamiana leaves. In addition, loss of AtNRP1 and AtNRP2 function attenuated ER stress-induced cell death in Arabidopsis, which was in marked contrast with the enhanced cell death phenotype displayed by overexpressing lines as compared to Col-0. Furthermore, atnrp-1 knockout mutants displayed enhanced sensitivity to PEG-induced osmotic stress, a phenotype that could be complemented with ectopic expression of either GmNRP-A or GmNRP-B. In addition, AtNRPs, ANAC036 and gVPE were induced by osmotic and ER stress to an extent that was modulated by the ER-resident molecular chaperone binding protein (BiP) similarly as in soybean. Finally, as putative downstream components of the NRP-mediated cell death signaling, the stress induction of AtNRP2, ANAC036 and gVPE was dependent on the AtNRP1 function. BiP overexpression also conferred tolerance to water stress in Arabidopsis, most likely due to modulation of the drought-induced NRP-mediated cell death response. CONCLUSION: Our results indicated that the NRP-mediated cell death signaling operates in the plant kingdom with conserved regulatory mechanisms and hence may be target for engineering stress tolerance and adaptation in crops.

Actívatexto: Feasibility and Acceptability of a Mobile Intervention That Promotes Smoking Cessation and Physical Activity among Latinos.

The purpose of this study was to assess the feasibility and acceptability of a mobile intervention that promotes smoking cessation and physical activity among Latinos living in the United States. Twenty Latino adults who smoked and did not meet recommended levels of physical activity were recruited using community-based recruitment strategies. Participants received Actívatexto, a theory-based, culturally accommodated, 12-week text messaging intervention (available in English and Spanish) that promotes smoking cessation and physical activity. Actívatexto integrates four components: (i) a text messaging program, (ii) a wearable device, (iii) an online dashboard where the research team manages participants' incoming and outgoing data from both the text messaging program and wearable device, and (iv) nicotine replacement therapies (NRT). We assessed self-reported 7-day point prevalence smoking abstinence at month 3, weekly minutes of moderate to vigorous physical activity (MVPA), pharmacotherapy adherence, and satisfaction. At baseline, participants' mean age was 47.3 years old (SD 16.0), 55% of participants were female, and 60% indicated that Spanish was their language of preference. Seventy-five percent of participants smoked 1-10 cigarettes daily and 35% smoked their first cigarette within 5 minutes after waking up. At month 3, 14 participants (70%) self-reported 7-day point prevalence smoking abstinence (90% follow-up rate). Fitbit-assessed mean minutes of MVPA per week increased from 113 (SD 127; range: 0-399) at week 1 to 177 (SD 163; range: 0-513) at month 3 (P = 0.15). Sixteen participants (88.9%, 16/18) reported NRT use in the past 90 days. Most participants reported being extremely satisfied or satisfied with the intervention (88.9%, 16/18). SIGNIFICANCE: Actívatexto resulted in a noteworthy cessation rate at month 3 (70%), increased mean weekly minutes of MVPA, produced high use of NRT, and was well received by participants. Additional testing in a randomized clinical trial is warranted to assess the efficacy of the intervention.

In silico approaches for predicting natural compounds with therapeutic potential and vaccine candidates against Streptococcus equi.

Equine strangles is a prevalent disease that affects the upper respiratory in horses and is caused by the Gram-positive bacterium Streptococcus equi. In addition to strangles, other clinical conditions are caused by the two S. equi subspecies, equi and zooepidemicus, which present relevant zoonotic potential. Treatment of infections caused by S. equi has become challenging due to the worldwide spreading of infected horses and the unavailability of effective therapeutics and vaccines. Penicillin treatment is often recommended, but multidrug resistance issues arised. We explored the whole genome sequence of 18 S. equi isolates to identify candidate proteins to be targeted by natural drug-like compounds or explored as immunogens. We considered only proteins shared among the sequenced strains of subspecies equi and zooepidemicus, absent in the equine host and predicted to be essential and involved in virulence. Of these, 4 proteins with cytoplasmic subcellular location were selected for molecular docking with a library of 5008 compounds, while 6 proteins were proposed as prominent immunogens against S. equi due to their probabilities of behaving as adhesins. The molecular docking analyses revealed the best ten ligands for each of the 4 drug target candidates, and they were ranked according to their binding affinities and the number of hydrogen bonds for complex stability. Finally, the natural 5-ring compound C25H20F3N5O3 excelled in molecular dynamics simulations for the increased stability in the interaction with UDP-N-acetylenolpyruvoylglucosamine reductase (MurB). This research paves the way to developing new therapeutics to minimize the impacts caused by S. equi infections.Communicated by Ramaswamy H. Sarma.

Ethanol binge drinking exposure during adolescence displays long-lasting motor dysfunction related to cerebellar neurostructural damage even after long-term withdrawal in female Wistar rats.

Ethanol is one of the psychoactive substances most used by young individuals, usually in an intermittent and episodic manner, also called binge drinking. In the adolescent period, brain structures undergo neuromaturation, which increases the vulnerability to psychotropic substances. Our previous studies have revealed that ethanol binge drinking during adolescence elicits neurobehavioral alterations associated with brain damage. Thus, we explored the persistence of motor function impairment and cerebellum damage in the context of ethanol withdrawal periods (emerging adulthood and adult life) in adolescent female rats. Female Wistar rats (35 days old) received orally 4 cycles of ethanol (3.0 g/kg/day) or distilled water in 3 days on-4 days off paradigm (35th until 58th day of life). Motor behavioral tests (open field, grip strength, beam walking, and rotarod tests) and histological assays (Purkinje's cell density and NeuN-positive cells) were assessed on the 1-, 30-, and 60-days of binge alcohol exposure withdrawal. Our findings demonstrate that the adolescent binge drinking exposure paradigm induced cerebellar cell loss in all stages evaluated, measured through the reduction of Purkinje's cell density and granular layer neurons. The cerebellar tissue alterations were accompanied by behavioral impairments. In the early withdrawal, the reduction of spontaneous movement, incoordination, and unbalance was seen. However, the grip strength reduction was found at long-term withdrawal (60 days of abstinence). The cerebellum morphological changes and the motor alterations persisted until adulthood. These data suggest that binge drinking exposure during adolescence causes motor function impairment associated with cerebellum damage, even following a prolonged withdrawal, in adult life.

Degradation of Dyes Catalyzed by Aminophenyl-Substituted Mn-Porphyrin Immobilized on Chloropropyl Silica Gel and Evaluation of Phytotoxicity.

A heterogenized Mn(III) porphyrin-based catalyst was prepared for dye degradation. The new Mn(III) complex of 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin was immobilized, via covalent bond, in chloropropyl silica gel, generating the material (Sil-Cl@MnP) with a loading of 23 µmol manganese porphyrin (MnP) per gram of Sil-Cl. This material was used as a catalyst in degradation reactions of model dyes, a cationic dye [methylene blue (MB)] and an anionic dye (reactive red 120, RR120), using PhI(OAc)2 and H2O2 as oxidants. The oxidation reactions were carried out after the dye reached adsorption/desorption equilibrium with the catalytic material, with a much higher percentage of adsorption being observed for the cationic MB dye (20%) than for the anionic RR120 dye (3%), which may be associated with electrostatic attraction or repulsion effects, respectively, with the negatively charged surface of the silica (zeta potential measurement for Sil-Cl@MnP, ζ = -19.2 mV). In general, there was a higher degradation percentage for MB than for RR120, probably because the size and charge of RR120 would hinder its approach to the MnP active species on the silica surface. With respect to the oxidant, the PhI(OAc)2-based systems showed a higher degradation percentage than those of H2O2. It was observed that the increase in the oxidant concentration promoted a significant increase in the degradation of MB, with a degradation of approximately 65%. The efficiency of the catalyst was also evaluated after successive additions of the oxidant every 2 h, and it can be seen that the catalyst had no loss of efficiency, with a degradation percentage greater than 80% being observed after 8 h of reaction. The phytotoxicity of the products formed in the system was evaluated in a 1:23.5:188 molar ratio Sil-Cl@MnP: MB:PhI(OAc)2 was used. In these studies, phytotoxicity was found for the germination of lettuce seeds when the original solution was used without dilution; however, when diluted (10% V/V), the results were close to the positive and negative controls. Thus, the material obtained proved to be a potential candidate for application in the degradation reactions of environmental pollutants.

Big jaw, small genome: first description of the mitochondrial genome of Odontomachus (Formicidae, Ponerinae): evolutionary implications for Ponerinae ants.

Mitochondrial DNA is a valuable tool for population genetics and evolutionary studies in a wide range of organisms. With advancements in sequencing techniques, it's now possible to gain deeper insights into this molecule. By understanding how many genes there are, how they're organized within the molecule, identifying the presence of spacers, and analyzing the composition of the D-Loop, we can better grasp the rearrangements that play a crucial role in the evolutionary dynamics of mitochondrial DNA. Additionally, phylogenetic analyses benefit significantly from having access to a larger pool of mtDNA genes. This wealth of genetic information allows for the establishment of evolutionary relationships with greater accuracy than ever before, providing a more robust framework than analyses based on a limited number of genes. Studies on mitogenomes belonging to the family Formicidae have proven promising, enabling the identification of gene rearrangements and enhancing our understanding of the internal relationships within the group. Despite this, the number of mitogenomes available for the subfamily Ponerinae is still limited, and here we present for the first time the complete mitogenome of Odontomachus. Our data reveal a gene duplication event in Formicidae, the first involving trnV, and new gene arrangements involving the trnM-trnI-trnQ and trnW-trnC-trnY clusters, suggesting a possible synapomorphy for the genus. Our phylogenetic analysis using the PCGs available for Formicidae supports the monophyly of the subfamily Ponerinae and sheds light on the relationship between Odontomachus and Pachycondyla.

Air pollution from forest burning as environmental risk for millions of inhabitants of the Brazilian Amazon: an exposure indicator for human health.

In this study, we propose an indicator of air pollution exposure to identify potential hazardous areas for human health in the Amazon and Central-West Regions of Brazil from 2010 to 2019. This indicator aggregates both concentrations and time of exposure to fine particulate matter (PM2.5), according to the current limit recommended by the World Health Organization (WHO). We used daily PM2.5 averages obtained from the Brazilian Health Integrated Environmental Information System (SISAM) to calculate the percentages of days with PM2.5 concentrations exceeding the limit of 15µg/m³ per year and per month. From 2010 to 2019, the months from August to October presented the largest areas and the highest percentages of days with unacceptable pollution concentration values, harmful to human health. These areas were concentrated in the Arc of Deforestation. Therefore, 60% of the residents of the Amazon and Central-West regions were subjected to inadequate air quality for approximately six months per year. The proposed indicator is reproducible and appropriate to monitor areas of exposure and risk for human health.

Characterization of six new complete mitochondrial genomes of Chiasmodontidae (Scombriformes, Percomorpha) and considerations about the phylogenetic relationships of the family.

The fishes of the Chiasmodontidae family, known as swallower fishes, are species adapted to live in deep seas. Several studies have shown the proximity of this family to Tetragonuridae and Amarsipidae. However, the phylogenetic position of this clade related to other Pelagiaria groups remains uncertain even when phylogenomic studies are employed. Since the low number of published mitogenomes, our study aimed to assemble six new mitochondrial genomes of Chiasmodontidae from database libraries to expand the discussion regarding the phylogeny of this group within Scombriformes. As expected, the composition and organization of mitogenomes were stable among the analyzed species, although we detected repetitive sequences in the D-loop of species of the genus Kali not seen in Chiasmodon, Dysalotus, and Pseudoscopelus. Our phylogeny incorporating 51 mitogenomes from several families of Scombriformes, including nine chiasmodontids, recovered interfamilial relationships well established in previous studies, including a clade containing Chiasmodontidae, Amarsipidae, and Tetragonuridae. However, phylogenetic relationships between larger clades remain unclear, with disagreements between different phylogenomic studies. We argue that such inconsistencies are not only due to biases and limitations in the data but mainly to complex biological events in the adaptive irradiation of Scombriformes after the Cretaceous-Paleogene extinction event.

Cellulose Hydrogel with Hyaluronic Acid and Silver Nanoparticles: Sustained-Release Formulation with Antibacterial Properties against Pseudomonas aeruginosa.

Pathogenic bacteria resistant to conventional antibiotics represent a global challenge and justify the need for new antimicrobials capable of combating bacterial multidrug resistance. This study describes the development of a topical hydrogel in a formulation composed of cellulose, hyaluronic acid (HA), and silver nanoparticles (AgNPs) against strains of Pseudomonas aeruginosa. AgNPs as an antimicrobial agent were synthesized by a new method based on green chemistry, using arginine as a reducing agent and potassium hydroxide as a carrier. Scanning electron microscopy showed the formation of a composite between cellulose and HA in a three-dimensional network of cellulose fibrils, with thickening of the fibrils and filling of spaces by HA with the presence of pores. Ultraviolet-visible spectroscopy (UV-vis) and particle size distribution for dynamic light scattering (DLS) confirmed the formation of AgNPs with peak absorption at ~430 nm and 57.88 nm. AgNPs dispersion showed a minimum inhibitory concentration (MIC) of 1.5 µg/mL. The time-kill assay showed that after 3 h of exposure to the hydrogel containing AgNPs, there were no viable cells, corresponding to a bactericidal efficacy of 99.999% in the 95% confidence level. We obtained a hydrogel that is easy to apply, with sustained release and bactericidal properties against strains of Pseudomonas aeruginosa at low concentrations of the agent.