Resurgence of human respiratory syncytial virus during COVID-19 pandemic in Southern Brazil.

Respiratory Syncytial Virus (RSV) is an important cause of respiratory infection in humans. Severe cases are common in children ≤2 years old, immunocompromised individuals, and the elderly. In 2020, RSV infection reduced in Rio Grande do Sul (RS), southern Brazil; however, in 2021 resurgence of RSV was observed. This study analyzed epidemiological and genetic features of RSV infection cases reported in 2021 in RS. Nasopharyngeal samples collected from individuals with respiratory infection negative for SARS-CoV-2, Influenza A and B viruses were assessed for the presence of RSV by real time RT-qPCR. RSV-A and RSV-B genomic sequencing and phylogenetic reconstructions were performed for genotyping and clade characterization. Among 21,035 respiratory samples analyzed, 2,947 were positive for RSV, 947 of which were hospitalized patients. Positive cases were detected year-round, with the highest number in June-July (winter). Children <1 year comprised 56.28% (n = 533) of the hospitalized patients infected with RSV, whereas 14.46% (n = 137) were individuals >60 years. Of a total of 361 deaths, 14.68% (n = 53) were RSV positive, mostly patients >60 years old (73.58%, n = 39). Chronic kidney disease, cardiopathy, Down syndrome and neurological diseases were associated with RSV infection. RSV-A was identified in 58.5% (n = 117/200) of the patients, and RSV-B in 41.5% (n = 83/200). Of 95 RSV genomes recovered from SARI cases, 66 were RSV-A GA.2.3.5 genotype, while 29 were RSV-B GB.5.0.5a genotype. This study provides epidemiological and molecular data on RSV cases in RS during the COVID-19 pandemic and highlights that investigation of different respiratory viruses is essential for decision-making and disease prevention and control measures.

Utilizing COVID-19 as a Model for Diagnostics Using an Electrochemical Sensor.

This paper reports a rapid and sensitive sensor for the detection and quantification of the COVID-19 N-protein (N-PROT) via an electrochemical mechanism. Single-frequency electrochemical impedance spectroscopy was used as a transduction method for real-time measurement of the N-PROT in an immunosensor system based on gold-conjugate-modified carbon screen-printed electrodes (Cov-Ag-SPE). The system presents high selectivity attained through an optimal stimulation signal composed of a 0.0 V DC potential and 10 mV RMS-1 AC signal at 100 Hz over 300 s. The Cov-Ag-SPE showed a log response toward N-PROT detection at concentrations from 1.0 ng mL-1 to 10.0 µg mL-1, with a 0.977 correlation coefficient for the phase (θ) variation. An ML-based approach could be created using some aspects observed from the positive and negative samples; hence, it was possible to classify 252 samples, reaching 83.0, 96.2 and 91.3% sensitivity, specificity, and accuracy, respectively, with confidence intervals (CI) ranging from 73.0 to 100.0%. Because impedance spectroscopy measurements can be performed with low-cost portable instruments, the immunosensor proposed here can be applied in point-of-care diagnostics for mass testing, even in places with limited resources, as an alternative to the common diagnostics methods.

Chemical contamination affecting filter-feeding bivalves in no-take marine protected areas from Brazil.

Marine protected areas (MPAs) are zones geographically delimited under pre-defined management goals, seeking to reduce anthropogenic threats to biodiversity. Despite this, in recent years reports of MPAs affected by chemical contamination has grown. Therefore, this study addresses this critical issue assessing legacy and current chemical contamination in filter-feeder bivalves obtained in very restrictive no-take MPAs from Brazil. The detected pollutants encompass polycyclic aromatic hydrocarbons (PAHs), linear alkylbenzenes (LABs), and persistent organic pollutants (POPs) like dichlorodiphenyltrichloroethane (DDTs) and polychlorinated biphenyls (PCBs). Despite protective measures, bivalves from nine MPAs exhibited high LABs (13.2-1139.0 ng g-1) and DDTs levels (0.1-62.3 ng g-1). PAHs were present in low concentrations (3.1-29.03 ng g-1), as PCBs (0.7-6.4 ng g-1), hexachlorobenzene (0.1-0.2 ng g-1), and Mirex (0.1-0.3 ng g-1). Regardless of the sentinel species, MPAs and management categories, similar accumulation patterns were observed for LABs, DDTs, PAHs, and PCBs. Based on the limits proposed by Oslo Paris Commission, the measured levels of PAHs, PCBs and were below the environmental assessment criteria. Such findings indicate the no biological effects are expected to occur. However, they are higher considering background conditions typically measured in remote or pristine areas and potential simultaneous exposure. Such findings indicate an influence of anthropogenic sources, emphasizing the urgency for monitoring programs guiding strategic management efforts to safeguard these areas.

A RP-HPLC-DAD method for analysis of Brazilian southeast brown propolis and its leishmanicidal properties.

Propolis is a natural product of great economic and pharmacological importance. The flora surrounding the bee communities is a determining factor in the composition of propolis and therefore in its biological and medicinal properties. Brown propolis is one of the most important types of propolis in Brazil, produced in the southeastern region. The ethanolic extract of a brown propolis sample from Minas Gerais state was chemically characterized for the subsequent development of a RP-HPLC method, validated according to the standards of regulatory agencies. The leishmanicidal activity of this extract was assessed. The brown propolis was characterized by the presence of chemical markers reported on green propolis such as ferulic acid, coumaric acid, caffeic acid, cinnamic acid, baccharin, artepillin and drupanin, indicating a probable origin on Baccharis dracunculifolia. The developed method agreed with the parameters established by the validation guidelines, then proved to be reliable for the analysis of this type of propolis. The brown propolis displayed significant activity against Leishmania amazonensis with IC50 values of 1.8 and 2.4 µg/ml against the promastigote and amastigote forms, respectively. The studied propolis exhibited promising evidence for use as a natural source against L. amazonensis.

Copaifera langsdorffii Oleoresin-Loaded Nanostructured Lipid Carrier Emulgel Improves Cutaneous Healing by Anti-Inflammatory and Re-Epithelialization Mechanisms.

The skin is essential to the integrity of the organism. The disruption of this organ promotes a wound, and the organism starts the healing to reconstruct the skin. Copaifera langsdorffii is a tree used in folk medicine to treat skin affections, with antioxidant and anti-inflammatory properties. In our study, the oleoresin of the plant was associated with nanostructured lipid carriers, aiming to evaluate the healing potential of this formulation and compare the treatment with reference drugs used in wound healing. Male Wistar rats were used to perform the excision wound model, with the macroscopic analysis of wound retraction. Skin samples were used in histological, immunohistochemical, and biochemical analyses. The results showed the wound retraction in the oleoresin-treated group, mediated by α-smooth muscle actin (α-SMA). Biochemical assays revealed the anti-inflammatory mechanism of the oleoresin-treated group, increasing interleukin-10 (IL-10) concentration and decreasing pro-inflammatory cytokines. Histopathological and immunohistochemical results showed the improvement of re-epithelialization and tissue remodeling in the Copaifera langsdorffii group, with an increase in laminin-γ2, a decrease in desmoglein-3 and an increase in collagen remodeling. These findings indicate the wound healing potential of nanostructured lipid carriers associated with Copaifera langsdorffii oleoresin in skin wounds, which can be helpful as a future alternative treatment for skin wounds.

Antifungal and Phytotoxic Activities of Isolated Compounds from Helietta parvifolia Stems.

The identification of natural and environmentally friendly pesticides is a key area of interest for the agrochemical industry, with many potentially active compounds being sourced from numerous plant species. In this study, we report the bioassay-guided isolation and identification of phytotoxic and antifungal compounds from the ethyl acetate extract of Helietta parvifolia stems. We identified eight compounds, consisting of two coumarins and six alkaloids. Among these, a new alkaloid, 2-hydroxy-3,6,7-trimethoxyquinoline-4-carbaldehyde (6), was elucidated, along with seven known compounds. The phytotoxicity of purified compounds was evaluated, and chalepin (4) was active against Agrostis stolonifera at 1 mM with 50% inhibition of seed germination and it reduced Lemna pausicotata (duckweed) growth by 50% (IC50) at 168 µM. Additionally, we evaluated the antifungal activity against the fungal plant pathogen Colletotrichum fragariae using a thin-layer chromatography bioautography assay, which revealed that three isolated furoquinoline alkaloids (flindersiamine (3), kokusagenine (7), and maculine (8)) among the isolated compounds had the strongest inhibitory effects on the growth of C. fragariae at all tested concentrations. Our results indicate that these active natural compounds, i.e., (3), (4), (7), and (8), could be scaffolds for the production of more active pesticides with better physicochemical properties.

Impact of pretreatments with ethanol and freezing on drying slice papaya: drying performance and kinetic of ultrasound-assisted extraction of phenolics compounds.

BACKGROUND: Pretreatments of drying can represent an alternative to minimize the negative aspect process on the dry samples. Thus, the influence of ethanol (ET) and freezing (FG) as drying pretreatments was analyzed for slices of papaya. The slices (5 mm) were submitted for drying kinetics (60 °C and 1.5 m s-1 ). Drying kinetics experimental data were fitted using Page's model and a diffusive model with boundary condition of types I and III. Also the thermophysical properties (thermal conductivity and specific heat) were determined and finally, the kinetics of ultrasound-assisted (40 kHz and 132 W) extraction of total phenolic compounds (TPCs) were realized. RESULTS: The combined method (ET + FG) was more efficient in reducing the drying time of papaya slices (48%) and the model 2 simulating the boundary condition of the third type (type III) showed the best fit to the experimental data. Effective diffusivity and convective coefficient were higher for ET + FG, where the maximum reduction in water content was 91% compared to fresh slices. The pretreatments did not influence the thermal conductivity, however, they were significant in the specific heat and in the extraction of TPCs, being higher in the time of 180 min. CONCLUSION: It was confirmed in the results presented that the combined pretreatment ET + FG is the most viable for drying papaya slices. Furthermore, it was found to be the most efficient in minimizing the loss of TPCs. Therefore, this pretreatment has great potential for application in the development of high value-added foods. © 2022 Society of Chemical Industry.

Cigarette butts in two urban areas from Brazil: Links among environmental impacts, demography and market.

Environmental impacts are currently linked to smoking cigarette behavior, as cigarette butts (CBs) represent the most common litter item in natural areas. Despite this, even the best ranked Brazilian cities, in terms of urban cleaning, have no information about urban littered CBs. Thus, CBs were monitored in Santos and Niterói cities, aiming to assess contamination, Cigarette Butt Pollution Index (CBPI) and the illegal market size. CBs were collected in 36 walkways considering different land usage types and urban density levels. The CBPI was calculated, and brands were used to identify the size of the illegal market. CBs contamination in Santos (0.25 CBs/m2) was three times higher than Niterói (0.08 CBs/m2) and their occurrence and distribution presented no relationship with land usage types and urban population densities levels. CBPI = 17.6 was severe and the highest so far reported. A total of 28 cigarette brands were found both studied cities. Further, illegal cigarette consumption in Santos and Niteroi was estimated, based on brands of collected CBs, at 25.2% and 36.8%, respectively. Such data may be valuable for implementation of logistic reverse actions seeking to environmentally sustainable and socially resilient cities. Cigarette consumption threatens human life and the environment, and tobacco companies should be accountable for the pollution they generate.

In vitro comparison between antimicrobial and antibiofilm effects of Green Propolis and Baccharis dracunculifolia against Staphylococcus pseudintermedius isolate.

Staphylococcus pseudintermedius is the leading cause of canine pyoderma. Honeybee products are common to treat this and other types of infections. High average annual population loss of bees has been observed. This study evaluated antibacterial and antibiofilm profile of Green Propolis and Baccharis dracunculifolia against S. pseudintermedius and the chemical similarities among both. Ethanolic extracts were produced and chemically characterized. The isolates were subjected to treatment with the extracts in both planktonic and sessile forms. Green propolis minimum inhibitory concentration (MIC) was 0.156 mg / mL, and minimum bactericidal concentration (MBC) was 0.312mg / mL. Baccharis dracunculifolia extract MIC and MBC was 0.312mg / mL and 2.5 mg / mL, respectivelly. Both extracts reduced SD55 formation of biofilm at minimum inhibitory concentration and at 1/8 minimum inhibitory concentration. The results observed in relation to ED99, were similar for both extracts. Besides that, similar chemical indicators between both extracts, including the presence of Artepellin C, suggest that the Baccharis dracunculifolia extract could be an alternative to the Green Propolis extract in the treatment of staph infections.

Chemical characterization of Brazilian propolis using automated direct thermal desorption-gas chromatography-mass spectrometry.

BACKGROUND: Propolis, produced by honey bees, is used around the world, displaying several corroborated biological activities. Brazil is one of the leading producers of propolis, with a great diversity of types, each with a characteristically chemical fingerprint influenced by the flora of the local region. The secondary metabolite's composition of propolis strongly impacts its biological properties, and its chemical characterization is of great importance for its quality control. Several chromatographic techniques have been applied to characterize propolis, highlighting the extraction of its volatiles and its analysis through gas chromatography. Fourteen Brazilian propolis samples collected in four states, including brown, green and red propolis types, were chemically characterized using the automated direct thermal desorption-gas chromatography-mass spectrometry (DTD-GC-MS). RESULTS: Red propolis type was characterized by acyclic saturated hydrocarbons, fatty alcohols, terpenes, and phenylpropanoids as nonacosane, α-copaene, ß-amyrin acetate, anethole, and 7-O-methylvestitol. Brown propolis presented hydrocarbons, monoterpenes, and sesquiterpenes, as α-pinene and α-bisabolol. Brazilian green propolis presented polycyclic aromatic hydrocarbons and sesquiterpenes, including 1-methyl-octahydroanthracene, 2,5-dimethyl-γ-oxo-benzenebutanoic acid, nerolidol, and spathulenol. Principal component analysis (PCA) was performed, allowing for clustering brown and red propolis types, indicating a divergence with the chemical composition of the green propolis samples. The hierarchical cluster analysis (HCA) allowed the chemical fingerprint of each propolis type to be differentiated. CONCLUSION: Red propolis was characterized by sesquiterpenes, pterocarpans, and isoflavans; brown propolis was characterized by hydrocarbons, aldehydes, and monoterpenes, while green propolis samples were characterized by the presence of polycyclic aromatic hydrocarbons, sesquiterpenes, and naphthalene derivatives. © 2022 Society of Chemical Industry.

Nonclinical Toxicological Studies of Brazilian Red Propolis and Its Primary Botanical Source Dalbergia ecastaphyllum.

Propolis is one of the most widely used products in traditional medicine. One of the most prominent types of Brazilian propolis is the red one, whose primary botanical source is Dalbergia ecastaphyllum (L.) Taub. Despite the potential of Brazilian red propolis for developing new products with pharmacological activity, few studies guarantee safety in its use. The objective of this study was the evaluation of the possible toxic effects of Brazilian red propolis and D. ecastaphyllum, as well as the cytotoxicity assessment of the main compounds of red propolis on tumoral cell lines. Hydroalcoholic extracts of the Brazilian red propolis (BRPE) and D. ecastaphyllum stems (DSE) and leaves (DLE) were prepared and chromatographed for isolation of the major compounds. RP-HPLC-DAD was used to quantify the major compounds in the obtained extracts. The XTT assay was used to evaluate the cytotoxic activity of the extracts in the human fibroblast cell line (GM07492A). The results revealed IC50 values of 102.7, 143.4, and 253.1 µg/mL for BRPE, DSE, and DLE, respectively. The extracts were also evaluated for their genotoxic potential in the micronucleus assay in Chinese hamster lung fibroblasts cells (V79), showing the absence of genotoxicity. The BRPE was investigated for its potential in vivo toxicity in the zebrafish model. Concentrations of 0.8-6.3 mg/L were safe for the animals, with a LC50 of 9.37 mg/L. Of the 11 compounds isolated from BRPE, medicarpin showed a selective cytotoxic effect against the HeLa cell line. These are the initial steps to determine the toxicological potential of Brazilian red propolis.

Isolation of diterpenes from Araucaria sp Brazilian brown propolis and development of a validated high-performance liquid chromatography method for its analysis.

Propolis comprises a complex resinous product composed of plant's parts or exudates, pollen, bee wax, and enzymes. Brazilian brown propolis from Araucaria sp displays several biological activities. Considering the lack of validated analytical methods for its analysis, we are reporting the development of a validated high-performance liquid chromatography with photodiode array detector method to analyze Araucaria brown propolis. The crude propolis were extracted and chromatographed, furnishing six main diterpenes. The isolated standards were used to draw the analytical curves, allowing the studies of selectivity, precision, accuracy, recovery, robustness, the determination of limits of detection and limits of quantification. The mobile phase consisted of 0.1% acetic acid in water and acetonitrile, using an octadecylsilane column, 1 mL/min flow rate and detection at 200 or 241 nm. Relative standard deviation values obtained for intra-day and inter-day precision were lower than 4% for all diterpenes. From the five parameters for robustness, wavelength detection and flow rate were the critical ones. Limits of detection and quantification ranged from 0.808 to 10.359 µg/mL and from 2.448 to 31.392 µg/mL, respectively. The recoveries were between 105.03 and 108.13%, with relative standard deviation values around 5.0%. The developed method is precise, sensitive, and reliable for analyzing Araucaria brown propolis.

Artepillin C as an outstanding phenolic compound of Brazilian green propolis for disease treatment: A review on pharmacological aspects.

Propolis is a viscous resin consisting of plant material (shoots, flowers, and plant exudates), salivary secretions and waxes produced by Apis mellifera bees. Its popular use aroused the interests of scientific research, which proved to be a potential source of various bioactive substances. The chemical composition of propolis depends on several factors, such as the different types of plant sources collected by bees, geographic origin, and the time of year in which they are produced, but it is known that phenolic represent the main bioactive constituents of propolis. Baccharis dracunculifolia DC (Asteraceae) is the most important botanical source of propolis and a native to southeastern Brazil. It is widely known as the green propolis because of its deep green color. One of its major phenolic acids is artepillin C (Art-C), a diprenyl-p-hydroxycinnamic acid derivative. This review aims to provide a comprehensive summary of the pharmacological effects of Art-C. The limited number of publications on this topic over the past two decades have been collected from databases and summarized. Numerous biological activities have been described for the Art-C, such as gastroprotective, anti-inflammatory, antimicrobial, antioxidant, antitumor. This article describes aspects of occurrence, synthesis, biological activities and pharmacokinetic approaches.

Phytochemical, Antiplasmodial, Cytotoxic and Antimicrobial Evaluation of a Southeast Brazilian Brown Propolis Produced by Apis mellifera Bees.

Seven phenolic compounds (ferulic acid, caffeic acid, 4-methoxycinnamic acid, 3,4-dimethoxycinnamic acid, 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 1-O,2-O-digalloyl-6-O-trans-p-coumaroyl-ß-D-glucopyranoside), a flavanonol (7-O-methylaromadendrin), two lignans (pinoresinol and matairesinol) and six diterpenic acids/alcohol (19-acetoxy-13-hydroxyabda-8(17),14-diene, totarol, 7-oxodehydroabietic acid, dehydroabietic acid, communic acid and isopimaric acid) were isolated from the hydroalcoholic extract of a Brazilian Brown Propolis and characterized by NMR spectral data analysis. The volatile fraction of brown propolis was characterized by CG-MS, composed mainly of monoterpenes and sesquiterpenes, being the major α-pinene (18.4 %) and ß-pinene (10.3 %). This propolis chemical profile indicates that Pinus spp., Eucalyptus spp. and Araucaria angustifolia might be its primary plants source. The brown propolis displayed significant activity against Plasmodium falciparum D6 and W2 strains with IC50 of 5.3 and 9.7 µg/mL, respectively. The volatile fraction was also active with IC50 of 22.5 and 41.8 µg/mL, respectively. Among the compounds, 1-O,2-O-digalloyl-6-O-trans-p-coumaroyl-ß-D-glucopyranoside showed IC50 of 3.1 and 1.0 µg/mL against D6 and W2 strains, respectively, while communic acid showed an IC50 of 4.0 µg/mL against W2 strain. Cytotoxicity was determined on four tumor cell lines (SK-MEL, KB, BT-549, and SK-OV-3) and two normal renal cell lines (LLC-PK1 and VERO). Matairesinol, 7-O-methylaromadendrin, and isopimaric acid showed an IC50 range of 1.8-0.78 µg/mL, 7.3-100 µg/mL, and 17-18 µg/mL, respectively, against the tumor cell lines but they were not cytotoxic against normal cell lines. The crude extract of brown propolis displayed antimicrobial activity against C. neoformans, methicillin-resistant Staphylococcus aureus, and P. aeruginosa at 29.9 µg/mL, 178.9 µg/mL, and 160.7 µg/mL, respectively. The volatile fraction inhibited the growth of C. neoformans at 53.0 µg/mL. The compounds 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 7-oxodehydroabietic acid were active against C. neoformans, and caffeic and communic acids were active against methicillin-resistant Staphylococcus aureus.

Brazilian southeast brown propolis: gas chromatography method development for its volatile oil analysis, its antimicrobial and leishmanicidal activities evaluation.

INTRODUCTION: Propolis is widely used in folk medicine, and many factors can affect its chemical composition, including abiotic factors that can influence plants and bees. Therefore, analytical methods are powerful techniques in the quality control of such products. OBJECTIVE: Develop and validate an analytical method for quantifying volatile compounds in Brazilian brown propolis, and evaluate its biological activities. METHODS: A gas chromatography flame ionisation detector (GC-FID) analytical method was validated, attending the parameters of international validation guidelines as ANVISA 2017 and ICH 2005, for quantification of compounds present in volatile oils from propolis. Evaluation of cytotoxic, antimicrobial, and leishmanicidal activities of the oil. RESULTS: The compounds 1,8-cineole, terpinen-4-ol, α-copaene, ß-caryophyllene, γ-muurolene, nerolidol, spathulenol, and γ-palmitolactone were isolated from the volatile fraction of a Brazilian brown propolis and used in the method validation. All the validation parameters of the method were satisfactory. The volatile fraction displayed a significant leishmanicidal activity, with half maximal inhibition concentration (IC50 ) = 21.3 µg/mL against amastigote forms and IC50 = 25.1 µg/mL against promastigote forms of Leishmania amazonensis. The oil also displayed an antibacterial effect by inhibiting the growth of Streptococcus mutans and Staphylococcus aureus at 25 µg/mL and 50 µg/mL, respectively, but it was not cytotoxic against AGP-01, He-La and CHO-K1cell lines, with IC50 > 100 µg/mL. CONCLUSION: The GC-FID method can be a useful tool in the quality control of propolis material. The southeast brown propolis showed a high chemical complexity in its volatile fraction, which displayed leishmanicidal activity and bactericidal activity.

Effects of continuous and intermittent aerobic physical training on hormonal and metabolic profile, and body composition in women with polycystic ovary syndrome: A randomized controlled trial.

OBJECTIVE: To evaluate the effects of continuous (CA) and intermittent (IA) aerobic training on hormonal and metabolic parameters and body composition of women with polycystic ovary syndrome (PCOS). DESIGN: Prospective, interventional, randomized study. METHODS: Randomized controlled training (RCT) with sample allocation and stratification into three groups: CAT (n = 28) and IAT (n = 29) training and no training [control (CG), n = 30]. Before and after 16 weeks of intervention (CAT or IAT) or observation (CG), hormonal and metabolic parameters, body composition and anthropometric indices were evaluated. Aerobic physical training on a treadmill consisted of 30- to 50-minute sessions with intensities ranging from 60% to 90% of the maximum heart rate. RESULTS: In the CA group, there was reduction in waist circumference (WC) (P = .045), hip circumference (P = .032), cholesterol (P ≤ .001), low-density lipoprotein (P = .030) and testosterone (P ≤ .001). In the IAT group, there was a reduction in WC (P = .014), waist-to-hip ratio (P = .012), testosterone (P = .019) and the free androgen index (FAI) (P = .037). The CG showed increases in WC (P = .049), total body mass (P = .015), body fat percentage (P = .034), total mass of the arms (P ≤ .001), trunk fat percentage (P = .033), leg fat percentage (P = .021) and total gynoid mass (P = .011). CONCLUSION: CAT and IAT training reduced anthropometric indices and hyperandrogenism in PCOS, whereas only IAT training reduced the FAI. Furthermore, only CAT training improved the lipid profile.

Covid-19: the renin-angiotensin system imbalance hypothesis.

The emergency of SARS-CoV-2 in China started a novel challenge to the scientific community. As the virus turns pandemic, scientists try to map the cellular mechanisms and pathways of SARS-CoV-2 related to the pathogenesis of Coronavirus Disease 2019 (Covid-19). After transmembrane angiotensin-converting enzyme 2 (ACE2) has been found to be SARS-CoV-2 receptor, we hypothesized an immune-hematological mechanism for Covid-19 based on renin-angiotensin system (RAS) imbalance to explain clinical, laboratory and imaging findings on disease course. We believe that exaggerated activation of ACE/Angiotensin II (Ang II)/Angiotensin Type 1 (AT1) receptor RAS axis in line with reduction of ACE2/Angiotensin-(1-7)/Mas receptor may exert a pivotal role in the pathogenesis of Covid-19. In this perspective, we discuss potential mechanisms and evidence on this hypothesis.

Morphoanatomical injuries in Pistia stratiotes L. (Araceae) as a result of exposure to clomazone in water.

Contamination of water sources due to herbicide is of great concern. Clomazone is a pesticide with a high contamination potential which could possibility lixiviate to water streams. Changes caused by residual herbicide include flora modifications which are generally detrimental for some species. The lack of morphological studies performed in aquatic plants exposed to herbicide-contaminated environments has encouraged the development of our research. For the first time, we present a study that aimed to evaluate leaf injuries visible to the naked eye as well as microscopical effects which may be caused by clomazone on Pistia stratiotes. Pistia stratiotes was subjected to five concentrations of clomazone. Our analysis showed leaf injuries, especially after 15 days of clomazone application. Hormesis was observed when the water lettuce was subjected to the lower concentrations. Total leaf area showed increase following by reduction while injured until reaching the highest concentration. Although the concentrations of clomazone tested in our study are not lethal to water lettuce, such herbicide have still caused morphoanatomical damages on leaves which advocates for the use of P. stratiotes as a bioindicator of the presence of herbicides such as clomazone in water.

Reliable Methods for Analyses of Volatile Compounds of Copaifera Oleoresins Combining Headspace and Gas Chromatography.

Two analytical methods were developed in this study for direct and fast chemical investigation of authentic Copaifera oleoresins (COR) and commercial products. Polydimethylsiloxane microfiber coupled to gas chromatography-mass spectrometry (HS-SPME-GC/MS) showed the best results for oleoresin qualitative analysis, setting the following extraction conditions: equilibrium time of 15 min, extraction time of 30 min, extraction temperature at 60 °C and constant stirring of 400 rpm. Sesquiterpenes α-copaene, ß-elemene, ß-caryophyllene and trans-α-bergamotene were found in all investigated samples. Quantitative analysis by gas chromatography coupled with flame ionization detector (GC-FID) measured the content of the four sesquiterpenes in all samples. Qualitative and quantitative results showed important differences between COR of distinct species and commercial products. Data regarding the volatile composition of C. oblongifolia and C. trapezifolia oleoresins were first presented in this study and two new analytical methods were reported for direct and fast qualitative and quantitative analysis of COR.

Enhancing Key Management in LoRaWAN with Permissioned Blockchain.

Low-Power Wide-Area Network (LPWAN) is one of the enabling technologies of the Internet of Things (IoT), and focuses on providing long distance connectivity for a vast amount of smart devices. Currently, LoRa is one of the leading LPWAN solutions available for public use. In LPWANs, especially in LoRa, security is a major concern due to the resource constraints of the devices, the sensitivity level of the transmitted data, the large amount of connected devices, among other reasons. This paper studies the key management mechanism of LoRaWAN environments. A secure architecture for key management based on smart contracts and permissioned blockchain to enhance security and availability in LoRaWAN networks is proposed. To demonstrate the feasibility of the proposed blockchain-based LoRaWAN architecture, a working prototype has been created using open-source tools and commodity hardware. Performance analysis shows that the prototype presents similar execution time and latency values, when compared to a traditional system, especially for small and medium-sized LoRaWAN networks. We also discuss why the proposed solution can be used in environments with a large number of end-devices.