The effect of surface pre-treatment on the electrochemical response of boron-doped diamond (BDD) electrodes is reported. Initially, several examples from published works illustrate the dramatic ...changes observed when a cathodic polarisation is applied before measurements instead of the classically adopted anodic treatment. In particular, electroanalytical determinations of pesticides in pure and contaminated waters could only be possible after holding the BDD electrode at −3.0
V versus Ag/AgCl for 30
min. Cyclic voltammetry of well-known reversible systems such as K
4Fe(CN)
6 and ferrocene in aqueous solutions rendered the expected behaviour after the cathodic pre-treatment while for the usual anodic treatment considerable distortions were recorded. Electrochemical impedance spectroscopy carried out in the presence and in the absence of the mentioned electroactive species confirmed the previously observed differences. Nyquist plots showed that in both cases the resistance associated to a high-frequency element diminishes from over 300 to about 4
Ω
cm
2 when a cathodic pre-treatment replaces the anodic pre-treatment. Moreover, Mott–Schottky plots in the absence of electroactive species revealed that the flat-band potential decreases by ca. 250
mV when measurements are carried out after the cathodic pre-treatment. All these effects could be explained in terms of the presence of a discontinuous passive layer on the BDD surface but they still require further studies for a definite conclusion.
•Decentralised sewage monitoring was used to assess COVID-19 prevalence.•Relative prevalence index (RPI) was proposed to assess severity of pandemic in different regions.•Decay of SARS-CoV-2 RNA in ...sewage was estimated based on modelling.•Monitored areas had different peak length, week of peak occurrence, number of peaks.•The most vulnerable regions in the city were the hardest hit by the pandemic.
Brazil has become one of the epicentres of the COVID-19 pandemic, with cases heavily concentrated in large cities. Testing data is extremely limited and unreliable, which restricts health authorities’ ability to deal with the pandemic. Given the stark demographic, social and economic heterogeneities within Brazilian cities, it is important to identify hotspots so that the limited resources available can have the greatest impact. This study shows that decentralised monitoring of SARS-CoV-2 RNA in sewage can be used to assess the distribution of COVID-19 prevalence in the city. The methodology developed in this study allowed the identification of hotspots by comprehensively monitoring sewers distributed through Belo Horizonte, Brazil's third largest city. Our results show that the most vulnerable neighbourhoods in the city were the hardest hit by the pandemic, indicating that, for many Brazilians, the situation is much worse than reported by official figures.
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Cell membrane-derived particles (Mp) are rounded membrane-enclosed particles that are shed from tumor cells. Mp are formed from tumor membranes and are capable of tumor targeting and ...immunotherapeutic agents because they share membrane homology with parental cells; thus, they are under consideration as a drug delivery vehicle. Prostate-specific membrane antigen (PSMA), a transmembrane glycoprotein with enzymatic functionality, is highly expressed in Mp and extracellular vesicles (EV) from prostate cancer (PCa) with poor clinical prognosis. Although PSMA expression was previously shown in EV and Mp isolated from cell lines and from the blood of patients with high-grade PCa, no pathophysiological effects have been linked to PCa-derived Mp. Here, we compared Mp from PSMA-expressing (PSMA-Mp) and PSMA-non-expressing (WT-Mp) cells side by side in vitro and in vivo. PSMA-Mp can transfer PSMA and new phenotypic characteristics to the tumor microenvironment. The consequence of PSMA transfer to cells and increased secretion of vascular endothelial growth factor-A (VEGF-A), pro-angiogenic and pro-lymphangiogenic mediators, with increased 4E binding protein 1 (4EBP-1) phosphorylation.
Mycoplasma ovis infection in goat farms from northeastern Brazil Machado, Carolina A.L.; Vidotto, Odilon; Conrado, Francisco O. ...
Comparative immunology, microbiology and infectious diseases,
December 2017, 2017-Dec, 2017-12-00, 20171201, Letnik:
55
Journal Article
Recenzirano
•First report of a molecular investigation of M. ovis infection in goats from South America.•M. ovis is highly prevalent in goats from northeastern Brazil, mainly in dairy animals.•No association ...between M. ovis infection and the presence of ticks was observed.•Anemia was a common find in Mycoplasma-infected animals.
Although Mycoplasma ovis (formerly Eperythrozoon ovis) has been described in small ruminants worldwide, data on M. ovis in goats remain scarce. Accordingly, the aims of the present study were to i) determine the prevalence of hemoplasmas in goats, ii) identify the tick species parasitizing the animals, and iii) determine factors associated with infection in five dairy and three beef goat farms from the Paraíba State, northeastern Brazil. Blood samples were obtained from 402 goats. Samples were screened for hemoplasmas using a pan-hemoplasma PCR. The positive samples were confirmed by sequencing. An epidemiological questionnaire was given to each farm owner addressing age, gender, and presence of ticks. A total of 158/402 (39.3%) goats were positive for M. ovis by PCR. Sequencing of PCR positive samples has shown ≥99% identity with multiple M. ovis 16S rDNA sequences deposited in GenBank, including M. ovis isolates from humans. Dairy (OR=2.15; 95% CI: 1.40–3.32%; P=0.0004) and anemic goats (OR=2.33; 95% CI: 1.51–3.71%; P=0.0001) were more likely to be infected than beef and non-anemic animals, respectively. Amblyomma parvum (49/52, 94.23%) and Rhipicephalus microplus (3/52, 5.77%) were the tick species found parasitizing the animals, with no significant association between the presence of ticks and infection by M. ovis (P=0.1164). This is the first reportedly molecular detection of M. ovis infection in goats from South America. In conclusion, M. ovis is highly prevalent in goats from northeastern Brazil, mainly in dairy animals.
•The reactions were carried out in catalysts absence and the alcohol was methanol.•The Rf value of 0.8 verified the formation of methyl esters.•The methyl ester can be obtained in chemical catalysts ...absence and no co-products.
This article aims to describe an alternative and innovative methodology to transform waste, frying oil in a potential energy source, the biodiesel. The biodiesel was produced from fatty acids, using a waste product of the food industry as the raw material. The methodology to be described is the corona discharge plasma technology, which offers advantages such as acceleration of the esterification reaction, easy separation of the biodiesel and the elimination of waste generation. The best conditions were found to be an oil/methanol molar ratio of 6:1, ambient temperature (25°C) and reaction time of 110min and 30mL of sample. The acid value indicates the content of free fatty acids in the biodiesel and the value obtained in this study was 0.43mgKOH/g. Peaks corresponding to octadecadienoic acid methyl ester, octadecanoic acid methyl ester and octadecenoic acid methyl ester, from the biodiesel composition, were identified using GC–MS. A major advantage of this process is that the methyl ester can be obtained in the absence of chemical catalysts and without the formation of the co-product (glycerin).
Highlights • Cerebral malaria mice showed significant memory impairment. • Infected mice showed reduction of BDNF mRNA expression in the CNS. • TRKB mRNA expression was enhanced in the CNS of ...infected mice. • Inflammatory cytokine levels were increased in the hippocampus of infected mice. • Infected mice showed neurogenesis reduction and increased hippocampal cell death.
We present a theoretical model for the longitudinal spin-Seebeck effect (LSSE) in bilayers made of a ferromagnetic insulator (FMI), such as yttrium iron garnet (YIG), and a normal metal (NM), such as ...platinum (Pt), that relies on the bulk magnon spin current created by the temperature gradient across the thickness of the FMI. We show that the spin current pumped into the NM layer by the magnon accumulation in the FMI provides continuity of the spin current at the FMI/NM interface and is essential for the existence of the longitudinal spin-Seebeck effect. The results of the theory are in good agreement with experimental data for the variation of the LSSE with the sample temperature and with the FMI layer thickness in YIG/Pt bilayers.
The goals of this research were to evaluate the phenotypic and genotypic correlations between agronomic traits, to perform path analysis, having as main character grain yield, and to identify ...indirect selection criteria for grain yield. The experiment was carried out in an experimental area located at Capim Branco farm, which belongs to Federal University of Uberlândia, during the growing season of 2015/2016.Twenty-four soybean genotypes were evaluated under randomized complete block design with three repetitions, of which agronomic traits and grain yield were measured. There was genetic variability for all traits at 5% probability level through the F-test. Thirty significant phenotypic correlations were also observed with values oscillating from 0.42 to 0.87, which indicated a high level of association between some evaluated traits. Additionally, we verified that phenotypic and genotypic correlations were essential of the same direction, being the genotypic ones of superior magnitudes. Plants with superior vegetative cycle had longer life cycles; this fact could be explained by the significant phenotypic correlations between the number of days to the blooming and number of days to maturity (0.76). Significantly positive phenotypic and genotypic correlations for the total number of pods per plant and grain yield per plant (0.84) were observed. Through the path analysis, the trait that contributed the most over grain yield was the number of pods with three seeds as it showed the highest direct effect on grain yield per plant, as well as a strong indirect effect on the total number of pods. Therefore, the phenotypic and genotypic correlations suggested high correlations between grain yield and number of branched nodes, the number of pods with two and three seeds, and the total number of pods. Also, the path analysis determined the number of pods with three seeds as having the highest favorable effect on grain yield, and thus, being useful for indirect selection toward productive soybean genotypes.
The palaeolimnological conditions of Mirim Lagoon, a large coastal shallow lagoon under the influence of historical human impacts related to the development of the primary sector of the economy were ...reconstructed. The first significant human impact consisted of locking the estuarine system to induce the transition from brackish to freshwater conditions. During this transition, the sedimentation rate consistently increased from pre-disturbance values of 0.25 cm yr−1 to >1 cm yr−1. A concomitant increase in nitrogen and carbon values was recorded indicating a related eutrophication process. The highest nutrient levels were achieved during the 1990s after the incorporation of cutting-edge technologies for agricultural production such as high-yielding varieties of rice resistant to climate variability and pests, and the use of inorganic fertilisers, pesticides and water supply controlled by irrigation. After 2011, the soybean production boosted and the area cultivated with this oilseed equalled the area of rice paddies, i.e., 2 × 105 ha. A sharp decrease in δ13C from −19 to −24‰ and in δ15N from 6 to 2‰ were observed in the sedimentary record, indicating a major shift in the composition of the organic matter after the agricultural intensification. Trace elements Cr, Cu, Ni and Zn showed a high positive correlation with Al and Fe, and enrichment factors near 1, indicating a natural and terrigenous source of these elements and also unpolluted conditions. However, the increase of As after 1990 and the positive correlation with Pb was associated with agricultural practices. All elemental ratios (K/Al, Ti/Al and V/Cr) showed constant pre-disturbance trends and a turning point ca. the 1990s. Microplastics were detected from the beginning of the 1990s and increased towards recent sediments, thus corroborating an anthropogenically impacted scenario. Therefore, the development of the primary sector of the economy exerted clear impacts on the environmental quality of the system.
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•Mirim Lagoon estuary was transformed into a freshwater body in 1977.•Subsequent growth of the primary sector of the economy was documented.•Sedimentation increases and eutrophication symptoms were observed after 1990.•After 2011, the inclusion of soy cultivation changed the organic matter composition.•Mirim Lagoon is the final fate of agricultural production waste.
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