The potent greenhouse gas methane (CH₄) is readily emitted from tropical reservoirs, often via ebullition (bubbles). This highly stochastic emission pathway varies in space and time, however, ...hampering efforts to accurately assess total CH₄ emissions from water bodies. We systematically studied both the spatial and temporal scales of ebullition variability in a river inflow bay of a tropical Brazilian reservoir. We conducted multiple highly resolved spatial surveys of CH₄ ebullition using a hydroacoustic approach supplemented with bubble traps over a 12-month and a 2-week timescale to evaluate which scale of variation was more important. To quantify the spatial and temporal variability of CH₄ ebullition, we used the quartile coefficients of dispersion at each point in space and time and compared their frequency distributions across the various temporal and spatial scales. We found that CH₄ ebullition varied more temporally than spatially and that the intra-annual variability was stronger than daily variability within 2 weeks. We also found that CH₄ ebullition was positively related to water temperature increase and pressure decrease, but no consistent relationship with water column depth or sediment characteristics was found, further highlighting that temporal drivers of emissions were stronger than spatial drivers. Annual estimates of CH₄ ebullition from our study area may vary by 75–174% if ebullition is not resolved in time and space, but at a minimum we recommend conducting spatially resolved measurements at least once during each major hydrologic season in tropical regions (i.e., in dry and rainy season when water levels are falling and rising, respectively).
On November 2015, one of Brazil's most important watersheds was impacted by the mine waste from Fundão dam collapse in Mariana. The mine waste traveled over 600 km along the Doce River before ...reaching the sea, causing severe devastation along its way. Here we assessed trace element concentrations and cytogenotoxic effects of the released mine waste. Water samples were collected along the Doce River ten days after the disaster in two impacted sites and one non-impacted site. Sampling points were located hundreds of kilometers downstream of the collapsed dam. Water samples were used for trace element quantification and to run an experiment using Allium cepa to test cytogenotoxicity. We found extremely high concentrations of particulate Fe, Al, and Mn in the impacted sites. We observed cytogenotoxic effects such as alterations in mitotic and phase indexes, and enhanced frequency of chromosomal aberrations. Our results indicate interferences in the cell cycle in impacted sites located hundreds of kilometers downstream of the disaster. The environmental impacts of the dam collapse may not only be far-reaching but also very likely long-lasting, because the mine waste may persist in the Doce River sediment for decades.
•Higher concentrations of particulate metals were found in impacted sites.•Cytogenotoxic effects were found in the impacted sites.•Mining waste affected genetic aspects of Allium cepa.•Impacts of the tragedy are far-reaching and long-lasting.
Background and aim
COVID-19 is a respiratory disease caused by the new coronavirus SARS-CoV-2, for which the first cases were reported in China, by December 2019. The spectrum of clinical ...presentations is wide, ranging from asymptomatic cases to a severe acute respiratory syndrome, sometimes with multiple systems involvement. Viral infections, including those related to respiratory virus, may cause hearing loss and, by extent, considering its pathophysiology, tinnitus. A systematic review on inner ear related symptoms in patients with COVID-19 reported 4.5% occurrence rate of tinnitus, with high variance of prevalence between the studies. Our aim is to further explore the relationship between COVID-19 and tinnitus. For this purpose we analyzed a sample of people who had suffered from a COVID-19 infection in the city of Volta Redonda, Brazil. In detail, we compared those with new onset tinnitus during or after the COVID-19 infection with those without tinnitus and those with tinnitus onset before the COVID-19 infection.
Methods
Fifty-seven patients over 18 years old and previously diagnosed with COVID-19 confirmed by a RT-PCR test were included. Patients were subdivided in three groups: no tinnitus (NT), tinnitus that already existed before COVID-19 (chronic tinnitus, CT) and tinnitus that arose during or after COVID-19 (post-COVID-19 tinnitus, PCT). Data concerning COVID-19 symptoms, drugs prescribed for COVID-19, tinnitus characteristics, comorbidities and other otological symptoms were collected. For all the patients, tonal audiometry and otoacoustic emissions were performed. Tinnitus patients fulfilled the Tinnitus Handicap Inventory (THI) and visual-analog scales (VAS) for loudness and distress. Patients with CT answered a simple question about the worsening of their tinnitus after COVID-19.
Results
PCT was reported by 19.3% of the patients, while 22.8% reported CT. No statistical difference was found between CT and PCT concerning hearing function, tinnitus characteristics and tinnitus distress. There was also no statistically significant difference between PCT and NT with respect to COVID-19 symptoms and pharmacological COVID-19 treatment. Patients with CT reported worsening of their tinnitus after COVID-19.
Conclusion
As with other viral infections, inner ear symptoms may be associated with COVID-19. In our sample patients with tinnitus onset before COVID-19 and those with tinnitus onset during or after COVID-19 did not differ significantly in their clinical characteristics and their hearing function, suggesting that tinnitus occurring in the context of a COVID-19 infection is not related to a unique pathophysiological mechanism. The comparison of COVID-19 patients, who developed tinnitus with those who did not develop tinnitus did not reveal any differences in COVID-19 symptoms or COVID-19 treatment. Thus, there was no hint, that a specific expression of COVID-19 is closely related to post COVID-19 tinnitus onset. Although some drugs used to treat tinnitus are known to damage the inner ear cells (especially hydroxychloroquine), we did not see any relationship between the intake of these drugs and tinnitus onset, eventually due to the short prescription time and low doses. Among those patients who had tinnitus before COVID-19 30,8% reported worsening after COVID-19. Overall, tinnitus emerging in the context of a COVID-19 infection seems not to differ from tinnitus unrelated to COVID-19. For further exploring the relationship of tinnitus and COVID-19, large population based studies are warranted.
Transcatheter aortic valve implantation (TAVI) has become the alternative procedure to high-risk patients who are diagnosed with aortic valve stenosis. Differently from the traditional open-chest ...surgical procedure, a small variation on the prosthetic aortic valve deployment angle is expected with the TAVI procedure. The hemodynamic patterns of the blood flow in the ascending aorta are related to the development of many cardiovascular diseases. There are, however, few data available in the literature correlating the aortic valve tilt angle to hemodynamic effects. In this work, a 3D printed aorta model made of a transparent silicon resin was produced, based on the anatomy of a specific patient submitted to a TAVI procedure. The stereoscopic Particle Image Velocimetry technique was employed to measure three-component velocity fields at closely spaced cross-sectional planes, along the ascending aorta. The measurements were performed for a constant flow rate corresponding to the peak of the systolic phase of the cardiac cycle. Averaged velocity fields and turbulent quantities were determined for both, the base case, with no valve tilt, and for cases with an inclination of 4° and 8°, oriented at the four anatomical directions of the human body reference system, namely anterior, posterior, right and left. The results revealed the dominant flow patterns in the ascending aorta formed by a jet-like inlet flow impinging on the curved aorta right wall, inducing a significant eccentricity on the axial velocity profile. Regions of reverse flow were identified and linked to the abrupt area change associated with the typical reduced inlet diameter of TAVI implants. The impinging flow and wall curvature effects established circulation patterns defining a helical flow structure. The influence of the inlet flow orientation on the flow turbulent characteristics was assessed by the spatial evolution of the turbulent kinetic energy (TKE), Reynolds and viscous stresses. The maximum values of TKE were found around the inlet jet boundaries and concentrated in the neighborhood of the right aorta wall where the eccentric axial flow prevailed. Spatial distributions of the maximum Reynolds stresses were similar to the TKE distributions and presented maximum stresses typically one order of magnitude higher than the maximum average viscous shear stresses. Maximum average viscous stress distributions were revealed at the jet-like flow boundaries and in the vicinity of the right wall, displaying moderate stress levels that, according to the literature, can be sufficient to produce cell damage and platelet activation. The complex nature of the flow field was revealed by streamlines obtained from the measured flow fields, allowing the identification of the influence of the inlet flow orientation and tilt angle on the position of the stagnation point on the aorta right wall, as well as the angle of incidence of the jet-like flow on the wall. A simple model based on momentum balance was used to estimate the pressure increment on the wall due to flow impingement. The model captured the influence of the inlet flow orientation, indicating that pressure increases of the order of 40% in relation to the base case condition were obtained for the 8°, left inlet flow orientation.
Graphic abstract
Topical application of aluminum-chloride phthalocyanine (AlClPc) is a challenge because of the drug's extremely low solubility, which prevents its absorption into deeper skin layers and causes ...molecule aggregation, reducing the photophysical effect. The goal of this study was to obtain a formulation applied in a certain condition that would allow homogeneous accumulation of AlClPc in cutaneous tissues, meaning a safer and non-invasive topical treatment for skin tumors based on photodynamic therapy. We first prepared and characterized AlClPc complexes with cyclodextrin to increase the photosensitizing agent solubility. The inclusion complex of AlClPc with hydroxypropyl-β-cyclodextrin (HP-βCD) amplified its loading dose in aqueous medium and maintained its photosensitizing properties in terms of reactive oxygen species production. Assays to determine the complex's in vitro cytotoxicity against murine melanoma skin cancer cells showed that when irradiated, the complex significantly reduced cell viability, whereas the absence of irradiation did not affect cell viability. Three physical techniques for permeation enhancement (i.e., tape-stripping abrasion, microneedle pretreatment and iontophoresis) were then evaluated. When applied in impaired skin, the complex could not increase drug penetration. The skin penetration of AlClPc, however, increased 2.3-fold following iontophoresis application in a shorter period compared to passive permeation. Therefore, these results suggest the administration of complexed AlClPc mediated by iontophoresis, followed by application of photodynamic therapy, might be an effective and non-invasive alternative for topical treatment of cutaneous tumors.
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Several studies have been developed regarding human health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various micro-organisms, ...including
. In this context, the objective of this study was to characterize
isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of
virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates and observed a great variation among them for the various virulence factors evaluated. In general, environmental isolates were more adherent to human buccal epithelial cells (HBEC) than
ATCC13803 reference strain, and they also showed increased biofilm production. Most of the isolates presented wrinkled phenotypes on Spider medium (34 isolates, 54.8%). The majority of the isolates also showed higher proteinase production than control strains, but low phospholipase activity. In addition, 35 isolates (56.4%) had high hemolytic activity (hemolysis index > 0.55). With regard to
resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride. The strains were highly resistant to the azoles tested (fluconazole, voriconazole and itraconazole). Fifteen strains were resistant to the three azoles tested (24.2%). Some strains were also resistant to amphotericin B (14 isolates; 22.6%), while all of them were susceptible for the echinocandins tested, except for a single strain of intermediate susceptibility to micafungin. Our results demonstrate that
isolated from the sand can fully express virulence attributes and showed a high persistence capacity on the coastal environment; in addition of showing high minimal inhibitory concentrations to several antifungal drugs used in current clinical practice, demonstrating that environmental isolates may have pathogenic potential.
is a Brazilian plant species that has been used in folk medicine to treat a range of diseases. Our ongoing work focuses on the discovery of new bioactive natural products derived from Brazilian ...flora. The current study describes the identification of cytotoxic compounds from the EtOH extract of leaves from
using bioactivity-guided fractionation. This approach resulted in the isolation and characterization of four compounds: cycloart-23
-ene-3
,25-diol (
), (23
*,24
*)-dihydroxycicloart-25-en-3-one (
), isopimara-7,15-diene-2
,3
-diol (
), and isopimara-7,15-dien-3
-ol (
), in which
and
are identified as new derivatives.
assays were conducted to evaluate the cytotoxic activity of compounds
-
against a panel of cancer cell lines and to determine the possible mechanism(s) related to the activity of the compounds on B16F10Nex2 cells. The most active compound
induced cytotoxic effects on tumor cells, with IC
values of 18.3, 52.1, and 58.9 µM against HL-60, HeLa, and B16F10-Nex2 tumor cells, respectively. Furthermore, it was observed in melanoma cells that compound
induced several specific apoptotic hallmarks, such as morphological changes in the cell shape structure, nuclear DNA condensation, specific chromatin fragmentation, and disruption in the mitochondrial membrane potential, which are related to the intrinsic apoptotic pathway.
The aim of this study was to determine the ideal level of neutral detergent fibre (NDF) that maximises productive performance and to evaluate the ingestive behaviour of feedlot Santa Inês lambs. ...Diets consisted of Tifton 85 grass hay (Cynodon sp.), with particle size from 1 to 2 cm, and concentrate, and the treatments were represented by different NDF levels (20, 32, 44, 56 and 68% NDF dry matter). There was a quadratic effect (P < 0.05) for the intake of dry matter, organic matter and crude protein, with maximum intake estimated at 27, 26 and 27% NDF. There was a quadratic effect (P < 0.05) for digestibility of crude protein and NDF, with the lowest digestibility estimated at 40 and 37% NDF. There was a quadratic effect (P < 0.05) for weight gain, average daily gain and feed efficiency, with maximum gains estimated at 27, 29 and 30% NDF. There was an effect (P < 0.05) of NDF levels on variables of ingestive behaviour periods/day of feeding, rumination and idle. For the feedlot Santa Inês lambs fed diets based on Tifton 85 grass hay, we recommend 27 - 30% neutral detergent fibre.
is able to switch from yeast to hyphal growth and this is an essential step for tissue invasion and establishment of infection. Due to the limited drug arsenal used to treat fungal infections and the ...constant emergence of resistant strains, it is important to search for new therapeutic candidates. Therefore, this study aimed to investigate by proteomic analysis the role of a natural product (
) in impairing hypha formation in
. We also tested the potential action of
to prevent and treat oral candidiasis induced in a murine model of oral infection and the ability of polymorphonuclear neutrophils to phagocytize
cells treated with the ethyl acetate fraction of the extract. We found that this fraction greatly reduced hypha formation after morphogenesis induction in the presence of serum. Besides, several proteins were differentially expressed in cells treated with the fraction. Surprisingly, the ethyl acetate fraction significantly reduced phagocytosis in
(Mean 120.36 ± 36.71 yeasts/100 PMNs vs. 44.68 ± 19.84 yeasts/100 PMNs). Oral candidiasis was attenuated when
cells were either pre-incubated in the presence of
or when the fraction was applied to the surface of the oral cavity after infection. These results were consistent with the reduction in CFU counts (2.36 vs. 1.85 Log10 CFU/ml) and attenuation of tissue damage observed with histopathological analysis of animals belonging to treated group. We also observed shorter true hyphae by direct examination and histopathological analysis, when cells were treated with the referred natural product. The
ethyl acetate fraction was non-toxic to human cells.
may act on essential proteins mainly related to cellular structure, reducing the capacity of filamentation and attenuating infection in a murine model, without causing any toxic effect on human cells, suggesting that it may be a future therapeutic alternative for the treatment of
infections.
Trypanosoma cruzi is a flagellated protozoan belonging to the Trypanosomatidae family, the etiologic agent of Chagas disease. Currently, there is neither a licensed vaccine nor effective treatment, ...characterizing an unmet clinical need. The IgY refers to the egg yolk immunoglobulin (Y=yolk) and its production and use are subjects of many studies due to the diversity of its diagnostic and therapeutic applications. Several researchers have shown that the use of specific IgY may prevent and/or control infectious and parasitic diseases. Based on these evidences, the aim of this study was to immunize chickens with trypomastigotes of T. cruzi in order to produce highly effective and pure antibodies (IgY), as well as extract, characterize, quantify, and verify cytotoxic effects of IgY anti-T. cruzi. After the induction of IgY production by chickens, the eggs were collected and the IgY was extracted by method of precipitation of polyethylene glycol 6000. The IgY anti-T. cruzi characterization was performed using polyacrylamide gel electrophoresis (SDS-PAGE), western-blot and enzyme-linked immunosorbent assay (ELISA). Moreover, the cytotoxic or proliferative effects of IgY anti-T. cruzi was verified by MTT assay. The concentration of IgY in yolk was 8.41±1.47mg/mL. The characterization of IgY reveled bands of stained peptides with molecular weight between 75 and 50kDa and 37 and 25kDa. In the ELISA test was observed that there was antigen-antibody reaction throughout the sample period. The concentrations of 1, 5 and 10mg/mL of IgY anti-T. cruzi presented no cytotoxic of proliferative effects in mononuclear and VERO cells in vitro. The results indicated that T. cruzi is able to generate a high production of specific immunoglobulins in chickens, it did not cause damage to the cell membrane and no proliferative effect.
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