Abstract
Limited information is available about the effect of mid-pregnancy viral infections on the placental expression of efflux transporters and offspring behavior. We hypothesized that maternal ...exposure to polyinosinic-polycytidylic acid poly(I:C), a synthetic double-stranded RNA viral mimic, would impair placental cell turnover, the expression of selected ABC transporters and adult offspring behavior. C57BL/6 mice were administered poly(I:C) (10 mg/Kg;ip) or vehicle at gestational day (GD) 13.5 (mid-pregnancy). Dams were euthanized for blood collection 4 h after injection, fetal and placental collection at GD18.5 or allowed to deliver spontaneously at term. At GD 13.5, poly(I:C) induced an acute pro-inflammatory response characterized by an increase in maternal plasma levels of IL-6, CXCL-1 and CCL-2/MCP-1. At GD 18.5, poly(I:C) decreased cell proliferation/death in the labyrinthine and increased cell death in the junctional zones, characterizing a disruption of placental cell turnover. Abca1 and Abcg1 immunolabelling was decreased in the labyrinthine zone, whereas Abca1, Abcg1 and breast cancer resistance transporter (Bcrp) expression increased in the junctional zone. Moreover, adult offspring showed motor and cognitive impairments in the Rotarod and T-water maze tests. These results indicate that viral infection during mid-pregnancy may disrupt relevant placental efflux transporters, as well as placental cell turnover and offspring behavior in adult life.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the worst global health crisis in living memory. The reverse transcription polymerase chain reaction (RT-qPCR) is considered ...the gold standard diagnostic method, but it exhibits limitations in the face of enormous demands. We evaluated a mid-infrared (MIR) data set of 237 saliva samples obtained from symptomatic patients (138 COVID-19 infections diagnosed via RT-qPCR). MIR spectra were evaluated via unsupervised random forest (URF) and classification models. Linear discriminant analysis (LDA) was applied following the genetic algorithm (GA-LDA), successive projection algorithm (SPA-LDA), partial least squares (PLS-DA), and a combination of dimension reduction and variable selection methods by particle swarm optimization (PSO-PLS-DA). Additionally, a consensus class was used. URF models can identify structures even in highly complex data. Individual models performed well, but the consensus class improved the validation performance to 85% accuracy, 93% sensitivity, 83% specificity, and a Matthew’s correlation coefficient value of 0.69, with information at different spectral regions. Therefore, through this unsupervised and supervised framework methodology, it is possible to better highlight the spectral regions associated with positive samples, including lipid (∼1700 cm–1), protein (∼1400 cm–1), and nucleic acid (∼1200–950 cm–1) regions. This methodology presents an important tool for a fast, noninvasive diagnostic technique, reducing costs and allowing for risk reduction strategies.
Control of Chagas disease in endemic countries is primarily accomplished through insecticide spraying for triatomine vectors. In this context, pyrethroids are the first‐choice insecticide, and the ...evolution of insect resistance to these insecticides may represent an important barrier to triatomine control. In insects, cytochrome P450s are enzymes involved in the metabolism of xenobiotics and endogenous chemicals that are encoded by genes divided into different families. In this work, we evaluated the role of three Rhodnius prolixus CYP4EM subfamily genes during blood meal and after deltamethrin exposure. CYP4 gene members were expressed in different insect organs (integument, salivary glands (SGs), midgut, fat body and malpighian tubules) at distinct transcriptional levels. CYP4EM1 gene was highly expressed in the SG and was clearly modulated after insect blood meal. Injection of CYP4EM1dsRNA promoted significant reduction in mRNA levels of both CYP4EM1 and CYP4EM2 genes and induced deleterious effects in R. prolixus nymphs subsequently exposed to sublethal doses of deltamethrin (3.4 or 3.8 ng/nymph treated). The higher dose reduced the survival over time and increased susceptibility of R. prolixus nymphs to deltamethrin. A better understanding of this mechanism can help in developing of more efficient strategies to reduce Trypanosoma cruzi vector transmission in Americas.
CYP4EM genes are differentially expressed in Rhodnius prolixus organs/tissues.
Injection of CYP4EM1 dsRNA in R. prolixus induced a long‐term silencing of CYP4EM1 and CYP4EM2 genes.
Silencing of CYP4EM genes increased deltamethrin intoxication and decreased this insecticide lethal time in R. prolixus.
Cytochrome P450 acts on insecticide detoxification in triatomines.
Designing and deploying telecommunications and broadcasting networks in the challenging terrain of the Amazon region pose significant obstacles due to its unique morphological characteristics. Within ...low-power wide-area networks (LPWANs), this research study introduces a comprehensive approach to modeling large-scale propagation loss channels specific to the LoRaWAN protocol operating at 915 MHz. The objective of this study is to facilitate the planning of Internet of Things (IoT) networks in riverside communities while accounting for the mobility of end nodes. We conducted extensive measurement campaigns along the banks of Universidade Federal do Pará, capturing received signal strength indication (RSSI), signal-to-noise ratio (SNR), and geolocated point data across various spreading factors. We fitted the empirical close-in (CI) and floating intercept (FI) propagation models for uplink path loss prediction and compared them with the Okumura-Hata model. We also present a new model for path loss with dense vegetation. Furthermore, we calculated received packet rate statistics between communication links to assess channel quality for the LoRa physical layer (PHY). Remarkably, both CI and FI models exhibited similar behaviors, with the newly proposed model demonstrating enhanced accuracy in estimating radio loss within densely vegetated scenarios, boasting lower root mean square error (RMSE) values than the Okumura-Hata model, particularly for spreading factor 9 (SF9). The radius coverage threshold, accounting for node mobility, was 945 m. This comprehensive analysis contributes valuable insights for the effective deployment and optimization of LoRa-based IoT networks in the intricate environmental conditions of the Amazon region.
Rhodnius prolixus expresses nitric oxide synthase (NOS) in the cytosol of the salivary gland (SG) cells. The NO produced is stored in the SG lumen bound to NO-carrier haemeproteins called ...nitrophorins (NPs). NPs bind tightly to NO in the acidic SG lumen, but release NO when the pH becomes high, e.g., at the host skin (pH~7.4). NO elicits potent and transient relaxation of vascular smooth muscle. Here, we investigated the role of salivary NO in the R. prolixus feeding behaviour and the salivary vasodilator activity of the host microcirculation. NOS knockdown in R. prolixus changed the SG colour, decreased the number of NO-loaded NPs and caused impairment of feeding performance. When salivary gland extracts (SGEs) were obtained from NOS- and NPs-knockdown insects and prepared in pH 5.0 solution and injected (i.v.) into mice via the tail vein, no vasodilation was observed, whereas SGEs from control insects caused long-term venodilation in the mouse skin. SGs disrupted directly in PBS (pH 7.4) containing BSA produced long-term vasodilation compared to the controls without BSA due to the possible formation of nitroso-albumin, suggesting that host serum albumin extends the NO half-life when NO is injected into the host skin by triatomine during their blood-feeding.
This work aims to improve the corrosion properties of the 2198-T851 aluminium alloy by coating with a set of niobium oxide thin films, using the reactive sputtering technique. The structural and ...morphological properties of the niobium oxide thin films were characterized by using SEM/EDX, AFM, FTIR and Raman spectroscopy. Global electrochemical tests (OCP, PPc, CV, and EIS) were performed in 0.6 mol L−1 NaCl solution. The results demonstrated that the reactive sputtering technique was advantageous for producing thin films on the 2198-T851 aluminium surface. Raman spectroscopy results revealed a band near 650 cm−1 related to NbO single bonds, whilst the band centred at 868 cm−1 may be attributed to NbO double bonds. The PPc results indicated that the niobium oxide acts as a protective barrier, since a difference of about 210 mV was observed between Epitting and Ecorr. The coated specimens displayed a superior breakdown potential when compared to the base material (−0.387 vs − 0.505 V/SCE). The impedance modulus has increased more than one order of magnitude and the phase angle is closer to - 90°, demonstrating a capacitive thin film was deposited on the 2198-T851 aluminium alloy surface.
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•The reactive sputtering method was able to produce NbxOy film on the 2198-T851.•Coated material has increased the impedance modulus more than one order of magnitude.•A difference of about 210 mV between the corrosion and pitting potentials was obtained..•A higher resistance to localised corrosion was achieved when compared to the untreated alloy.
This study aims to investigate the effects of melatonin on follicular growth, viability and ultrastructure, as well as on the levels of mRNA for antioxidant enzymes, reactive oxygen species (ROS) and ...meiotic progression in oocytes from in vitro cultured bovine early antral follicles. To this end, isolated early antral follicles (500–600 μm) were cultured in TCM‐199+ alone or supplemented with 10−6, 10−7 or 10−8 M melatonin at 38.5°C with 5% CO2 for 8 days. Follicle diameters were evaluated at days 0, 4 and 8 of culture. At the end of culture, ultrastructure, chromatin configuration, viability (calcein‐AM and ethidium homodimer‐1 staining), and the levels of ROS and mRNA for catalase (CAT), superoxide dismutase (SOD) and peroxiredoxin 6 (PRDX6) and glutathione peroxidase (GPx) were investigated in oocyte‐granulosa cell complexes (OGCs). The results showed that early antral follicles cultured with 10−6 and 10−8 M melatonin had a progressive and significant increase in their diameters throughout the culture period (p < .05). Additionally, oocytes from follicles cultured with 10−7 or 10−8 M melatonin had increased fluorescence for calcein‐AM, while those cultured with 10−6 or 10−7 M had reduced fluorescence for ethidium homodimer‐1. Different from follicles cultured in other treatments, those cultured with 10−8 M melatonin had well‐preserved ultrastructure of oocyte and granulosa cells. Melatonin, however, did not influence the levels of ROS, the mitochondrial activity, oocyte meiotic resumption and expression mRNA for SOD, CAT, GPX1 and PRDX6. In conclusion, the presence of 10−8 M melatonin in culture medium improves viability and preserves the ultrastructure of oocyte and granulosa cells of early antral follicles cultured in vitro.
BACKGROUND: TB is an infectious disease with a worldwide impact. TB is closely associated with social and housing conditions, exerting a significant impact on the prison population, which is ...particularly susceptible to the disease. Evidence suggests that the COVID-19 pandemic
has exacerbated social vulnerability. This study therefore aimed to analyse the impact of the pandemic on the diagnosis of new cases of TB in the Brazilian prison population in the years 2020 and 2021.METHODS: This is an ecological study involving cases of TB recorded in the prison
population of Brazil from 2015 to 2021. Data were collected from the Brazil’s Information System for Notifiable Diseases.RESULTS: The incidence of TB in the prison population in Brazil fell from 1,005.9/100,000 population between 2015 and 2019 to 852.3/100,000 population between
2020 and 2021. In 2021, there was a deficit of 539 cases (–7.6%) compared to what was expected for the year. In 2020, there was a 10% reduction in TB diagnoses in January and February, reaching 3.8% in March. A negative percentage was observed in most of the subsequent months. In 2021,
the year began with a 21.6% decline in January, returning to positive values only in August and September.CONCLUSION: The first years of the COVID-19 pandemic resulted in underdiagnosis of TB in the Brazilian prison population.
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