28 research outputs found

    In situ evaluation of fluoride-, stannous- and polyphosphate-containing solutions against enamel erosion

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    Objective To evaluate the anti-erosive effect of solutions containing sodium fluoride (F: 225 ppm of fluoride), sodium fluoride + stannous chloride (F + Sn: 225 ppm of fluoride + 800 ppm of stannous), sodium fluoride + stannous chloride + sodium linear polyphosphate (F + Sn + LPP: 225 ppm of fluoride + 800 ppm of stannous + 2% of sodium linear polyphosphate), and deionized water (C: control), using a four-phase, single-blind, crossover in situ clinical trial. Methods In each phase, 12 volunteers wore appliances containing 4 enamel specimens, which were submitted to a 5-day erosion-remineralization phase that consisted of 2 h of salivary pellicle formation with the appliance in situ, followed by 2 min extra-oral immersion in 1% citric acid (pH 2.4), 6x/day, with 90 min of exposure to saliva in situ between the challenges. Treatment with the test solutions was performed extra-orally for 2 min, 2x/day. At the end of the experiment, surface loss (SL, in μm) was evaluated by optical profilometry. Data were analyzed using ANOVA and Tukey tests (α = 0.05). The surface of additional specimens was evaluated by x-ray diffraction after treatments (n = 3). Results C (mean SL ± standard-deviation: 5.97 ± 1.70) and F (5.36 ± 1.59) showed the highest SL, with no significant difference between them (p > 0.05). F + Sn (2.68 ± 1.62) and F + Sn + LPP (2.10 ± 0.95) did not differ from each other (p > 0.05), but presented lower SL than the other groups (P < 0.05). Apatite and stannous deposits on specimen surfaces were identified in the x-ray analysis for F + Sn and F + Sn + LPP. Conclusions Sodium fluoride solution exhibited no significant anti-erosive effect. The combination between sodium fluoride and stannous chloride reduced enamel erosion, irrespective of the presence of linear sodium polyphosphate. Clinical significance Under highly erosive conditions, sodium fluoride rinse may not be a suitable alternative to prevent enamel erosion. A rinse containing sodium fluoride and stannous chloride was shown to be a better treatment option, which was not further improved by addition of the sodium linear polyphosphate

    Inoculation with the endophytic bacterium Herbaspirillum seropedicae promotes growth, nutrient uptake and photosynthetic efficiency in rice

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    Main conclusion: Higher vacuolar proton pump activity may increase plant energy and nutrient use efficiency and provide the nexus between plant inoculation with Herbaspirillum seropedicae and growth promotion. Abstract: Global change and growing human population are exhausting arable land and resources, including water and fertilizers. We present inoculation with the endophytic plant-growth promoting bacterium (PGPB) Herbaspirillum seropedicae as a strategy for promoting growth, nutrient uptake and photosynthetic efficiency in rice (Oryza sativa L.). Because plant nutrient acquisition is coordinated with photosynthesis and the plant carbon status, we hypothesize that inoculation with H. seropedicae will stimulate proton (H+) pumps, increasing plant growth nutrient uptake and photosynthetic efficiency at low nutrient levels. Plants were inoculated and grown in pots with sterile soil for 90 days. Herbaspirillum seropedicae endophytic colonization was successful and, as hypothesized, inoculation (1) stimulated root vacuolar H+ pumps (vacuolar H+-ATPase and vacuolar H+-PPase), and (2) increased plant growth, nutrient contents and photosynthetic efficiency. The results showed that inoculation with the endophytic bacterium H. seropedicae can promote plant growth, nutrient uptake and photosynthetic efficiency, which will likely result in a more efficient use of resources (nutrients and water) and higher production of nutrient-rich food at reduced economic and environmental costs.info:eu-repo/semantics/publishedVersio

    Distribuição Do Carbono Orgânico Nas Frações Do Solo Em Diferentes Ecossistemas Na Amazônia Central

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    Organic matter plays an important role in many soil properties, and for that reason it is necessary to identify management systems which maintain or increase its concentrations. The aim of the present study was to determine the quality and quantity of organic C in different compartments of the soil fraction in different Amazonian ecosystems. The soil organic matter (FSOM) was fractionated and soil C stocks were estimated in primary forest (PF), pasture (P), secondary succession (SS) and an agroforestry system (AFS). Samples were collected at the depths 0-5, 5-10, 10-20, 20-40, 40-60, 60-80, 80-100, 100-160, and 160-200 cm. Densimetric and particle size analysis methods were used for FSOM, obtaining the following fractions: FLF (free light fraction), IALF (intra-aggregate light fraction), F-sand (sand fraction), F-clay (clay fraction) and F-silt (silt fraction). The 0-5 cm layer contains 60% of soil C, which is associated with the FLF. The F-clay was responsible for 70% of C retained in the 0-200 cm depth. There was a 12.7 g kg-1 C gain in the FLF from PF to SS, and a 4.4 g kg-1 C gain from PF to AFS, showing that SS and AFS areas recover soil organic C, constituting feasible C-recovery alternatives for degraded and intensively farmed soils in Amazonia. The greatest total stocks of carbon in soil fractions were, in decreasing order: (101.3 Mg ha-1 of C - AFS) > (98.4 Mg ha-1 of C - FP) > (92.9 Mg ha-1 of C - SS) > (64.0 Mg ha-1 of C - P). The forms of land use in the Amazon influence C distribution in soil fractions, resulting in short- or long-term changes. © 2015, Revista Brasileira de Ciencia do Solo. All rights reserved

    Intraoperative thermal mapping of mammary tumors in dogs

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    Abstract In this study, videothermometry’s application in detecting mammary tumors in dogs is explored in-depth. The research hypothesizes that this technique can effectively identify cancerous tissues during surgery by analyzing thermal patterns. The methodology involved comparing thermal imaging results from dogs with palpable mammary nodules against a control group, focusing on capturing real-time thermal patterns. Results were significant, showing distinct thermal patterns in carcinomas. This indicates videothermometry’s capability in accurately identifying micro metastases and differentiating between neoplastic and non-neoplastic changes. The study concludes that videothermometry has considerable potential in enhancing surgical precision, especially in tumor resection and safety margin definition, but emphasizes the need for further research to thoroughly understand the thermal signatures of various mammary tumors in dogs

    Danger in the canopy: comparative proteomics and bioactivities of the venoms of the South American palm viper Bothrops bilineatus subspecies bilineatus and smaragdinus, and antivenomics of B. b. bilineatus (Rondônia) venom against the Brazilian pentabothropic antivenom

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    We report a structural and functional proteomics characterization of venoms of the two subspecies (Bothrops bilineatusbilineatus and B. b. smaragdinus) of the South American palm pit viper from the Brazilian state of Rondônia and B. b. smaragdinus from Perú. These poorly known arboreal and mostly nocturnal generalist predators are widely distributed in lowland rainforests throughout the entire Amazon region, where they represent an important cause of snakebites. The three B. bilineatus spp. venom samples exhibit overall conserved proteomic profiles comprising components belonging to 11 venom protein classes, with PIII (34–40% of the total venom proteins) and PI (8–18%) SVMPs and their endogenous tripeptide inhibitors (SVMPi, 8–10%); bradykinin-potentiating-like peptides (BBPs, 10.7–15%); snake venom serine proteinases (SVSP, 5.5–14%); C-type lectin-like proteins (CTL, 3–10%); phospholipases A2 (PLA2, 2.8–7.6%); cysteine-rich secretory proteins (CRISP, 0.9–2.8%); l-amino acid oxidases (LAO, 0.9–5%) representing the major components of their common venom proteomes. Comparative analysis of the venom proteomes of the two geographic variants of B. b. smaragdinus with that of B. b. bilineatus revealed that the two Brazilian taxa share identical molecules between themselves but not with Peruvian B. b. smaragdinus, suggesting hybridization between the geographically close, possibly sympatric, Porto Velho (RO, BR) B. b. smaragdinus and B. b. bilineatus parental populations. However, limited sampling does not allow determining the frequency of this event. The toxin arsenal of the South American palm pit vipers may account for the in vitro recorded collagenolytic, caseinolytic, PLA2, l-amino acid oxidase, thrombin-like and factor X-activating activities, and the clinical features of South American palm pit viper envenomings, i.e., local and progressively ascending pain, shock and loss of consciousness, spontaneous bleeding, and profound coagulopathy. The remarkable cross-reactivity of the Brazilian pentabothropic SAB antivenom toward the heterologous B. b. bilineatus venom suggests that the paraspecific antigenic determinants should have been already present in the venom of the last common ancestor of the Bothrops ″jararaca″ and ″taeniatus″ clades, about 8.5 Mya in the mid-late Miocene epoch of the Cenozoic era. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the data set identifiers PXD020043, PXD020026, and PXD020013.Ministerio de Ciencia, Innovación y Universidades/[BFU2017-89103-P]//EspañaUniversidad de Costa Rica/[]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

    Sobre o sinal de um downscaling dinâmico às oscilações intrassazonais de precipitação no setor norte do Nordeste do Brasil On the intraseasonal sign of the rainfall over northern Northeast Brazil simulated by a dynamic downscaling

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    Oscilações intrassazonais são fatores controladores da variabilidade pluviométrica interanual de áreas tropicais. O conhecimento de como os modelos numéricos reproduzem suas variabilidades é importante para entender melhor suas atuações e subsidiar operações de previsão de tempo e clima. Neste artigo investiga-se a sensibilidade de um modelo de downscaling dinâmico de precipitação na reprodução das oscilações intrassazonais observadas no setor norte do Nordeste do Brasil (SNNEB - 45ºW-37ºW e 2ºS-12ºS) no período de 1974 a 2000. Os resultados mostraram que a precipitação simulada sobre o SNNEB explicou aproximadamente 70% da variabilidade da precipitação observada no trimestre fevereiro a abril nesta região. Estatísticas de médias, desvios normalizados e percentuais neste trimestre, nessa região, em anos de contrastes climáticos nos Oceanos Pacífico e Atlântico Tropicais, também foram bem capturadas pela precipitação simulada através do downscaling. Análises espectrais com uso de ondeletas mostraram que o downscaling dinâmico tem potencial para reproduzir picos espectrais de precipitação observada no SNNEB nas escalas acima de 8 dias, e nas escalas entre 64 e 128 dias para o período de 01 de janeiro a 30 de junho.<br>Intraseasonal oscillations are factors controlling the interannual variability of tropical rainfall. The knowledge of how numerical models reproduce its variability is important to better understand their roles and support operations of weather and climate. This paper investigates the sensitivity of a downscaling dynamic precipitation model in predicting the intraseasonal oscillations observed in the northern sector of Northeast Brazil (SNNEB - 45°W-37ºW and 2ºS-12°S) during the period from 1974 to 2000. The results showed that rainfall was simulated on SNNEB explained more than 70% of the variability of rainfall observed in the quarter February to April in this region. Statistical of averages, standard deviations and percent this quarter, in this region in years of climatic contrasts in the Oceans Pacific and Atlantic Tropical were also well captured by the precipitation simulated by downscaling. Spectral analysis with the use of wavelets showed that dynamic downscaling has the potential to reproduce observed spectral peaks of precipitation in SNNEB scales up to 8 days and the scales between 64 and 128 days for the period January 1 to June 30
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