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1.
Science ; 374(6565): 355-359, 2021 Oct 15.
Article in English | MEDLINE | ID: mdl-34648328

ABSTRACT

Regeneration of skeletal muscle is a highly synchronized process that requires muscle stem cells (satellite cells). We found that localized injuries, as experienced through exercise, activate a myofiber self-repair mechanism that is independent of satellite cells in mice and humans. Mouse muscle injury triggers a signaling cascade involving calcium, Cdc42, and phosphokinase C that attracts myonuclei to the damaged site via microtubules and dynein. These nuclear movements accelerate sarcomere repair and locally deliver messenger RNA (mRNA) for cellular reconstruction. Myofiber self-repair is a cell-autonomous protective mechanism and represents an alternative model for understanding the restoration of muscle architecture in health and disease.


Subject(s)
Cell Nucleus/physiology , Muscle Fibers, Skeletal/physiology , Muscle, Skeletal/injuries , Muscle, Skeletal/physiology , Regeneration , Sarcomeres/physiology , Animals , Calcium/metabolism , Dyneins/metabolism , Mice , Microtubules/metabolism , Muscle Contraction , Muscle Fibers, Skeletal/ultrastructure , Muscle, Skeletal/ultrastructure , RNA, Messenger/metabolism , Signal Transduction , cdc42 GTP-Binding Protein/metabolism
2.
J Cell Sci ; 134(14)2021 07 15.
Article in English | MEDLINE | ID: mdl-34297126

ABSTRACT

Skeletal muscle myofibers are large and elongated cells with multiple and evenly distributed nuclei. Nuclear distribution suggests that each nucleus influences a specific compartment within the myofiber and implies a functional role for nuclear positioning. Compartmentalization of specific mRNAs and proteins has been reported at the neuromuscular and myotendinous junctions, but mRNA distribution in non-specialized regions of the myofibers remains largely unexplored. We report that the bulk of mRNAs are enriched around the nucleus of origin and that this perinuclear accumulation depends on recently transcribed mRNAs. Surprisingly, mRNAs encoding large proteins - giant mRNAs - are spread throughout the cell and do not exhibit perinuclear accumulation. Furthermore, by expressing exogenous transcripts with different sizes we found that size contributes to mRNA spreading independently of mRNA sequence. Both these mRNA distribution patterns depend on microtubules and are independent of nuclear dispersion, mRNA expression level and stability, and the characteristics of the encoded protein. Thus, we propose that mRNA distribution in non-specialized regions of skeletal muscle is size selective to ensure cellular compartmentalization and simultaneous long-range distribution of giant mRNAs.


Subject(s)
Muscle Fibers, Skeletal , Muscle, Skeletal , Cell Nucleus/genetics , RNA, Messenger/genetics , Tendons
3.
J Dent ; 96: 103334, 2020 05.
Article in English | MEDLINE | ID: mdl-32302640

ABSTRACT

OBJECTIVE: This study aimed to assess the survival and success of glass fiber posts compared to cast metal posts in teeth without ferrule. MATERIAL AND METHODS: An equivalency, prospective, double-blind (patient and outcome evaluator) randomized controlled trial (RCT) with parallel groups was designed to compare the clinical performance of cast metal and glass fiber posts cemented in endodontically treated teeth without ferrule (NCT01461239). Teeth were randomly allocated to the glass fiber or cast-metal post groups. All teeth were restored with single metal-ceramic crowns. Kaplan-Meier analysis with the log-rank test was used to test the success and survival between glass fiber and cast metal posts considering a cut-off value of P = 0.05. The annual failure rates were calculated considering the survival data for all restorations and separated by type of post after five years. RESULTS: A hundred and nineteen patients and 183 posts (72 cast metal posts and 111 glass fiber posts) were analyzed. The median follow-up was 62 months (IQR 37-81). The log-rank test for success (P = 0.26) and survival (P = 0.63) analyses did not present statistically significant differences. The AFR of both posts after 5 years was 1.5%. Considering the posts separately and after 5 years, cast metal posts presented AFR of 1.2% and glass fiber posts AFR of 1.7%. Most failures were in posterior teeth (16/23), 10 failures were classified as root fractures and 5 as post debonding. The follow-up rate was 95.3%. CONCLUSIONS: Glass fiber and cast metal posts showed good and similar clinical performance. CLINICAL SIGNIFICANCE: Results of this randomized controlled trial can help dentists to answer how the best technique to rehabilitate endodontically treated teeth with no remaining coronal wall.


Subject(s)
Post and Core Technique , Tooth Fractures , Tooth, Nonvital , Composite Resins , Crowns , Dental Stress Analysis , Glass , Humans , Metals
4.
J Environ Manage ; 264: 110470, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32250899

ABSTRACT

Making cheese manufacturing environmentally sustainable is a major concern in the integrated management of this industrial sector. This concern is mainly due to the environmental impact of the discharge of its wastewaters, carrying heavy loads of salinity, nutrients, organic matter, solids and oils and fats. These discharges must meet increasingly stringent quality requirements. Some physicochemical (e.g. coagulation-flocculation, precipitation, oxidation) and biological (e.g. aerobic and anaerobic bioreactors and wetlands) treatments have been studied to address this problem. However, these treatments involve costs that some producers cannot sustain, face difficulties with biological reactor operational stability and often fail to consistently produce effluents compatible with discharge standards. In this context, aiming at the design of a simple and economical treatment method, several precipitation processes were tested using a fixed dosage of CaCO3 (75 g/L), combined with different dosages of FeCl3, FeSO4 or Ca(OH)2. The goal of the treatment was to produce a supernatant that would be evaluated as to its suitability for discharge into natural water courses or municipal treatment systems, or for reuse applications. The generated sludge would be evaluated for possible agricultural valorization. Through the measurement of the relevant supernatant quality parameters and using statistical analysis, it was possible to choose the best dosages for each of the tested coagulants (1.0, 1.0 and 0.6 g/L for FeCl3, FeSO4 and Ca(OH)2, respectively). Among these, the most efficient treatment was obtained with CaCO3 75 g/L + FeSO4 1.0 g/L. For this best-case scenario, the treatment led to removal yield values of 55.1% for chemical oxygen demand (COD), 92.0% for total phosphorus, 95.7% for turbidity, 59.1% for total phenols, 94.3% for nitrates, 71.0% for nitrites, 51.0% for total solids (TS) and 97.2% for oils and fats. The treatment did not produce an effluent supernatant with adequate quality for direct discharge into water courses, serving however as an efficient pretreatment for agricultural reuse. All the sludges generated in these treatments showed good potential for agricultural valorization due to their high nutrient content, along with pH and conductivity values within the acceptable ranges for soil application. Thus, this work contributes for a better integration of the cheese manufacturing industry in the overall aims of water and nutrient resources recovery in rural, agricultural areas.


Subject(s)
Cheese , Wastewater , Bioreactors , Fertilizers , Sewage , Waste Disposal, Fluid
5.
Eur J Neurosci ; 51(6): 1377-1387, 2020 03.
Article in English | MEDLINE | ID: mdl-31454441

ABSTRACT

Microglia cells exert a critical role in brain development, mainly supported by their immune functions, which predicts an impact on the genesis of psychiatric disorders. In fact, microglia stress during gestation is, for instance, associated with chronic anxiety and cognitive deficits accompanied by long-lasting, region- and sex-specific changes in microglia morphology. We recently reported that the pattern of microglia morphologic plasticity, which is sex-determined, impacts on anxious-like behaviour and cognition. We also reported that the pharmacologic blockade of adenosine A2A receptors (A2A R) is able to reshape microglia morphology, in a sex-specific manner and with behavioural sequelae. In order to better understand the role of A2A R in the sex differentiation of microglia, we now compared their morphology in wild-type and A2A R knockout male and female C57BL/6 mice in two cardinal brain regions implicated in anxiety-like behaviour and cognition, the prefrontal cortex (PFC) and the dorsal hippocampus (dHIP). We report interregional differences between PFC and dHIP in a sex-specific manner: while males presented more complex microglia in the dHIP, microglia from females had a more complex morphology in the PFC. Surprisingly, the genetic deletion of A2A R did not alter these sex differences, but promoted the exclusive remodelling (increase in complexity) in PFC microglia from females. These findings further support the existence of a heterogeneous microglial network, distinct between sexes and brain regions, and help characterizing the role of A2A R in the sex- and brain region-specific morphologic differentiation of microglia.


Subject(s)
Microglia , Receptor, Adenosine A2A , Sex Characteristics , Adenosine , Animals , Brain/metabolism , Female , Hippocampus/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Microglia/metabolism , Receptor, Adenosine A2A/genetics , Receptor, Adenosine A2A/metabolism
6.
Ecotoxicol Environ Saf ; 191: 110007, 2020 Mar 15.
Article in English | MEDLINE | ID: mdl-31796253

ABSTRACT

The biodegradation of dyes remains one of the biggest challenges of textile wastewater. Azo dyes are one of the most commonly employed dye classes, and biological treatment processes tend to generate recalcitrant aromatic amines, which are more toxic than the parent dye molecule. This study aimed to isolate bacterial strains with the capacity to degrade both the azo dye and the resulting aromatic amines towards the development of a simple and reliable treatment approach for dye-laden wastewaters. A mixed bacterial enrichment was first developed in an anaerobic-aerobic lab-scale sequencing batch reactor (SBR) fed with a synthetic textile wastewater containing the model textile azo dye Acid Red 14 (AR14). Eighteen bacterial strains were isolated from the SBR, including members of the Acinetobacter, Pseudomonas and Oerskovia genera, Oerskovia paurometabola presenting the highest decolorization capacity (91% after 24 h in static anaerobic culture). Growth assays supported that this is a facultative bacterium, and decolorization batch tests with 20-100 mg AR14 L-1 in a synthetic textile wastewater supplemented with yeast extract indicated that O. paurometabola has a high color removal capacity for a significant range of AR14 concentrations. In addition, a model typically used to describe biodegradation of xenobiotic compounds was adjusted to the results, to predict AR14 biodegradation time profiles at different initial concentrations. HPLC analysis confirmed that decolorization occurred through azo bond reduction under anaerobic conditions, the azo dye being completely reduced after 24 h of anaerobic incubation for the range of concentrations tested. Interestingly, partial (up to 63%) removal of one of the resulting aromatic amines (4-amino-naphthalene-1-sulfonic acid) was observed when subsequently subjected to aerobic conditions. Overall, this work showed the azo dye biodegradation potential of specific bacterial strains isolated from mixed culture bioreactors, reporting for the first time the decolorization capacity of an Oerskovia sp. with further biodegradation of a recalcitrant sulfonated aromatic amine metabolite.


Subject(s)
Actinobacteria/metabolism , Azo Compounds/metabolism , Coloring Agents/metabolism , Wastewater/chemistry , Water Pollutants, Chemical/metabolism , Amines/metabolism , Bacteria/isolation & purification , Bacteria/metabolism , Biodegradation, Environmental , Bioreactors/microbiology , Color , Textiles
7.
Mol Neurobiol ; 56(3): 2202-2210, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30003516

ABSTRACT

Diabetes mellitus is a chronic disease with numerous complications that severely impact on the quality of life of patients. Different neuropathies may arise as complications associated with the nervous system, both peripherally and at the central level. The mechanisms behind these neuronal complications are far from being clarified, but axonal transport impairment, a vital process for neuronal physiology, has been described in the context of experimental diabetes. Alterations in neuronal cytoskeleton and motor proteins, deficits in ATP supply or neuroinflammation, as processes that disturb the effective transport of cargoes along the axon, were reported as putative causes of axonal impairment, ultimately leading to axonal degeneration. The main goal of the present review is to reunite the main studies in the literature exploring diabetes-induced alterations likely involved in axonal transport deficits, and call the attention for the uttermost importance of further exploring the field. Understanding the mechanisms underlying neuronal deficits in diabetes is crucial for the development of new therapeutic strategies to prevent neuronal degeneration in diabetes and related neuropathies.


Subject(s)
Axonal Transport/physiology , Cytoskeleton/metabolism , Diabetic Neuropathies/metabolism , Animals , Dyneins/metabolism , Humans , Kinesins/metabolism
8.
Sci Total Environ ; 658: 830-835, 2019 Mar 25.
Article in English | MEDLINE | ID: mdl-30583178

ABSTRACT

This study investigated the occurrence of storage mechanisms in biofilm from constructed wetlands (CWs) through respirometric studies and calculated the corresponding heterotrophic growth yields. Respirometric tests were performed in biofilm extracted from horizontal sub-surface flow CWs batch loaded with three different COD mass loads: 7.0., 15.6 and 35.2 g COD/(m2∙day). The bed removal efficiency remained above 96% for all mass loads and COD mass removal rates increased from 6.8 g COD/(m2∙day) for the lowest load to 34.5 g COD/(m2∙day) for the highest load. The percentage of tests with storage evidence decreased from 85% to 10% with increasing mass loads and the responses of the microbial community to the acetate pulse showed an adaptation to the feast-famine conditions, through storage mechanisms, for lower loads, and a metabolic shift to the use of COD for growth for higher loads. Heterotrophic biomass yield values varied from 0.54-0.56 g COD/g COD for low mass loads to 0.69-0.71 for higher mass loads, indicating that greater substrate availably triggers growth and reduces the occurrence of storage. Storage yield values supported this trend varying between 0.89 and 0.94 with increasing mass loads. Given the significant storage evidence obtained in the present study, it is suggested that a modified modelling architecture, which includes storage mechanisms, should be considered in future simulations of CW systems.


Subject(s)
Bacterial Physiological Phenomena , Biofilms , Waste Disposal, Fluid/methods , Wetlands , Biomass , Heterotrophic Processes , Models, Theoretical
9.
Eng. sanit. ambient ; 23(4): 757-766, jul.-ago. 2018. tab, graf
Article in Portuguese | LILACS | ID: biblio-953282

ABSTRACT

RESUMO Este trabalho teve por objetivo produzir lodo granular aeróbio num reator em batelada sequencial não tubular, uma geometria diferente da usualmente utilizada nesses sistemas. Este reator foi inoculado com lodo ativado proveniente de uma estação de tratamento de esgoto municipal. O reator foi operado com ciclos de seis horas, com cinco horas de reação totalmente aeróbia. O efluente simulado continha um derivado de amido usado na indústria têxtil. A indução da granulação foi conseguida por meio da redução gradual do tempo de sedimentação, verificando-se que este é um parâmetro crítico do sistema. Após estabilização, com um tempo de sedimentação de 3 minutos, obteve-se um índice volumétrico de lodo de 25 mL.gSST-1, uma concentração de biomassa de 7 gSST.L-1 e uma eficiência de remoção da demanda química de oxigênio de 88%. Os grânulos obtidos foram armazenados úmidos durante 7 meses, a 4 e 25ºC, obtendo-se resultados excecionais na repartida dos reatores, com rápida recuperação das suas características de sedimentação, taxa de crescimento, estrutura e integridade granulares.


ABSTRACT This study aimed to produce aerobic granular sludge in a non-tubular sequencing batch reactor, which is an unusual geometry in these systems. This reactor was inoculated with activated sludge from a municipal wastewater treatment plant. The reactor was operated in cycles of six hours, with five hours of fully aerobic reaction. The simulated wastewater contained a starch derivative used in the textile industry. Granulation was induced by gradually reducing the settling time; therefore, this is a critical parameter of the system. After stabilization, with a sedimentation time of 3 minutes, a Sludge Volume Index after 30 minutes of settling of 25 mL.gSST-1, a biomass concentration of 7 gTSS.L-1 and a Chemical Oxygen Demand removal of 88% were obtained. The granules were stored wet for 7 months at 4 and 25ºC, yielding exceptional results in the re-start of the reactor, with rapid recovery of their sedimentation characteristics, growth rate, and granular structure and integrity.

10.
J Environ Qual ; 47(4): 718-725, 2018 Jul.
Article in English | MEDLINE | ID: mdl-30025066

ABSTRACT

The soil organic matter (SOM) content and dynamic are related to vegetation cover, climate, relief, and geology; these factors have strong variation in space in the southeastern of Brazil. The objective of the study was to compare and evaluate performance of classical multiple linear regressions (MLR) and geographically weighted regression (GWR) models to predict soil organic carbon (SOC) and chemical fractions of organic matter in the Brazilian southeastern mountainous region. The regression models were fitted based on SOC and chemical fractions of SOM. The points ( = 89) were selected by pedologist's experience along transects and toposequences. The covariates were also selected using the empirical knowledge of pedologists when choosing variables that drive soil carbon content and its dynamics. Geology map, legacy soils map, terrain attributes derived from digital elevation model, and remote sensing indices derived from RapidEye sensor bands were used as covariates. In all MLR models (except for fulvic acid fraction [FAF]), the legacy soil map was selected as a covariate by the stepwise approach. The geology map was not selected as important covariate to predict FAF and humin (HUM). At least one variable derived from remote sensing was selected by the adjusted models. For the prediction of the SOC, HUM, and FAF, the GWR models had the highest performance. The MLR models extrapolated the results, especially for SOC. The relationships among SOC, SOM fractions, and environmental covariates were affected by local landscape variability, and the GWR model was better at modeling.


Subject(s)
Carbon/analysis , Soil/chemistry , Brazil , Climate , Models, Theoretical , Spatial Regression
11.
Environ Monit Assess ; 190(6): 364, 2018 May 27.
Article in English | MEDLINE | ID: mdl-29804219

ABSTRACT

The increasing concern regarding the preservation of soil quality suggests the adoption of quality reference values as a first step in environmental monitoring actions. In this context, the objective of this study was to establish soil quality reference values for Al, Zn, Mn, Cd, Fe, Pb, Ni, Cr, and Cu and to correlate several soil properties with the occurrence of these elements in the hillslope region of Rio de Janeiro State. Sixty-two samples were collected at depths of 0-20 and 20-40 cm and analyzed using the USEPA method 3051A. After clustering analysis, the samples were separated into three groups. Classification functions were obtained based on the variables pH - Mg - Fe - Mn, i.e., the variables that were best related to heavy metal content. We determined to establish the quality reference values for the 75th percentile of the three groups. The relief forms of the area, which facilitate the transport of soil fine-particle fractions and accumulation in lowlands, were revealed to be one of most important factors in understanding the distribution of soil heavy metals.


Subject(s)
Metals, Heavy/analysis , Soil Pollutants/analysis , Brazil , Environmental Monitoring/methods , Reference Values , Soil/chemistry
12.
Front Pharmacol ; 9: 219, 2018.
Article in English | MEDLINE | ID: mdl-29615903

ABSTRACT

The exposure to supra-physiological levels of glucocorticoids in prenatal life can lead to a long-term impact in brain cytoarchitecture, increasing the susceptibility to neuropsychiatric disorders. Dexamethasone, an exogenous glucocorticoid widely used in pregnant women in risk of preterm delivery, is associated with higher rates of neuropsychiatric conditions throughout life of the descendants. In animal models, prenatal dexamethasone exposure leads to anxious-like behavior and increased susceptibility to depressive-like behavior in adulthood, concomitant with alterations in neuronal morphology in brain regions implicated in the control of emotions and mood. The pharmacologic blockade of the purinergic adenosine A2A receptor, which was previously described as anxiolytic, is also able to modulate neuronal morphology, namely in the hippocampus. Additionally, recent observations point to an interaction between glucocorticoid receptors (GRs) and adenosine A2A receptors. In this work, we explored the impact of dexamethasone on neuronal morphology, and the putative implication of adenosine A2A receptor in the mediation of dexamethasone effects. We report that in vitro hippocampal neurons exposed to dexamethasone (250 nM), in the early phases of development, exhibit a polarized morphology alteration: dendritic atrophy and axonal hypertrophy. While the effect of dexamethasone in the axon is dependent on the activation of adenosine A2A receptor, the effect in the dendrites relies on the activation of GRs, regardless of the activation of adenosine A2A receptor. These results support the hypothesis of the interaction between GRs and adenosine A2A receptors and the potential therapeutic value of modulating adenosine A2A receptors activation in order to prevent glucocorticoid-induced alterations in developing neurons.

13.
Environ Res ; 164: 32-38, 2018 07.
Article in English | MEDLINE | ID: mdl-29475106

ABSTRACT

The ability of microalgae to grow in nutrient-rich environments and to accumulate nutrients from wastewaters (WW) makes them attractive for the sustainable and low-cost treatment of WW. The valuable biomass produced can be further used for the generation of bioenergy, animal feed, fertilizers, and biopolymers, among others. In this study, Scenedesmus obliquus was able to remove nutrients from different wastewaters (poultry, swine and cattle breeding, brewery and dairy industries, and urban) with removal ranges of 95-100% for nitrogen, 63-99% for phosphorus and 48-70% for chemical oxygen demand. The biomass productivity using wastewaters was higher (except for poultry) than in synthetic medium (Bristol), the highest value being obtained in brewery wastewater (1025 mg/(L.day) of freeze-dried biomass). The produced biomass contained 31-53% of proteins, 12-36% of sugars and 8-23% of lipids, regardless of the type of wastewater. The potential of the produced Scenedesmus obliquus biomass for the generation of BioH2 through batch dark fermentation processes with Enterobacter aerogenes was evaluated. The obtained yields ranged, in mL H2/g Volatile Solids (VS), from 50.1 for biomass from anaerobically digested cattle WW to 390 for swine WW, whereas the yield with biomass cultivated in Bristol medium was 57.6 mL H2/gVS.


Subject(s)
Biofuels , Biotechnology , Microalgae , Scenedesmus , Animals , Biomass , Cattle , Nitrogen , Phosphorus , Poultry , Swine , Wastewater
14.
Arch Oral Biol ; 87: 157-162, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29304422

ABSTRACT

Tooth bleaching is considered a non-invasive treatment, although the use of highly-concentrated products may provoke increased surface roughness and enamel demineralization, as well as postoperative sensitivity. Thus, the aim of this study was to investigate whether hydrogen peroxide (H2O2) concentration would affect tooth bleaching effectiveness and the enamel surface properties. Enamel/dentin bovine specimens (6 × 4 mm) were immersed in coffee solution for 7 days and evaluated with a spectrophotometer (Easyshade; baseline), using the CIEL*a*b* color parameters. Hardness was measured using a hardness tester. The specimens were randomly assigned into four groups: one negative control, in which the specimens were not bleached, but they were irradiated with a laser-light source (Whitening Lase II, DMC Equipments); and three groups using distinct H2O2 concentration, namely LP15% (15% Lase Peroxide Lite), LP25% (25% Lase Peroxide Sensy), and LP35% (35% Lase Peroxide Sensy), all products from DMC. The bleached specimens were also irradiated with the laser-light source. After bleaching, all specimens were evaluated using scanning electron microscopy (SEM). pH kinetics and rate was monitored during bleaching. The data were analyzed using ANOVA and Tukey's test (p < 0.05). All bleaching gels produced similar color change (p > 0.05). Concerning hardness, only the LP25% and LP35% significantly reduced hardness after bleaching; also, there was a progressive tendency for a greater percentage reduction in hardness with increased H2O2 concentration of the gel (R2 = 0.9973, p < 0.001). SEM showed that LP25% and LP35% produced an etching pattern on enamel with prism rods exposure. In conclusion, H2O2 concentration above the 15% level does not increase bleaching effectiveness, and may increase the possibility for alteration of enamel hardness, surface morphology, and acidity of the medium. When using H2O2-based bleaching agents, dental practitioners should choose for less concentrated gels, e.g., around the 15% level.


Subject(s)
Dental Enamel/drug effects , Hydrogen Peroxide/chemistry , Tooth Bleaching Agents/chemistry , Tooth Bleaching/methods , Animals , Cattle , Color , Hardness Tests , Hydrogen-Ion Concentration , In Vitro Techniques , Microscopy, Electron, Scanning , Random Allocation , Surface Properties
15.
Biotechnol Adv ; 36(1): 228-246, 2018.
Article in English | MEDLINE | ID: mdl-29157974

ABSTRACT

Aerobic granular sludge technology has been extensively studied over the past 20 years and is regarded as the upcoming new standard for biological treatment of domestic and industrial wastewaters. Aerobic granules (AG) are dense, compact, self-immobilized microbial aggregates that allow better sludge-water separation and thereby higher biomass concentrations in the bioreactor than conventional activated sludge aggregates. This brings potential practical advantages in terms of investment cost, energy consumption and footprint. Yet, despite the relevant advances regarding the process of AG formation, instability of AG during long-term operation is still seen as a major barrier for a broad practical application of this technology. This paper presents an up-to-date review of the literature focusing on AG stability, aiming to contribute to the identification of key factors for promoting long-term stability of AG and to a better understanding of the underlying mechanisms. Operational conditions leading to AG disintegration are described, including high organic loads, particulate substrates in the influent, toxic feed components, aerobic feeding and too short famine periods. These operational and influent wastewater composition conditions were shown to influence the micro-environment of AG, consequently affecting their stability. Granule stability is generally favored by the presence of a dense core, with microbial growth throughout the AG depth being a crucial intrinsic factor determining its structural integrity. Accordingly, possible practical solutions to improve granule long-term stability are described, namely through the promotion of minimal substrate concentration gradients and control of microbial growth rates within AG, including anaerobic, plug-flow feeding and specific sludge removal strategies.


Subject(s)
Aerobiosis , Bioreactors , Extracellular Polymeric Substance Matrix
16.
Appl Spectrosc ; 70(3): 443-54, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26798079

ABSTRACT

Online monitoring programs based on spectroscopy have a high application potential for the detection of hazardous wastewater discharges in sewer systems. Wastewater hydraulics poses a challenge for in situ spectroscopy, especially when the system includes storm water connections leading to rapid changes in water depth, velocity, and in the water quality matrix. Thus, there is a need to optimize and fix the location of in situ instruments, limiting their availability for calibration. In this context, the development of calibration models on bench spectrophotometers to estimate wastewater quality parameters from spectra acquired with in situ instruments could be very useful. However, spectra contain information not only from the samples, but also from the spectrophotometer generally invalidating this approach. The use of calibration transfer methods is a promising solution to this problem. In this study, calibration models were developed using interval partial least squares (iPLS), for the estimation of total suspended solids (TSS) and chemical oxygen demand (COD) in sewage from Ultraviolet-visible spectra acquired in a bench scanning spectrophotometer. The feasibility of calibration transfer to a submersible, diode array equipment, to be subsequently operated in situ, was assessed using three procedures: slope and bias correction (SBC); single wavelength standardization (SWS) on mean spectra; and local centering (LC). The results showed that SBC was the most adequate for the available data, adding insignificant error to the base model estimates. Single wavelength standardization was a close second best, potentially more robust, and independent of the base iPLS model. Local centering was shown to be inadequate for the samples and instruments used.


Subject(s)
Sewage/analysis , Spectrophotometry, Ultraviolet/methods , Water Pollutants, Chemical/analysis , Biological Oxygen Demand Analysis , Calibration , Least-Squares Analysis , Spectrophotometry, Ultraviolet/instrumentation , Wastewater/analysis
17.
Water Res ; 85: 327-36, 2015 Nov 15.
Article in English | MEDLINE | ID: mdl-26343991

ABSTRACT

This study analyzed the effect of an azo dye (Acid Red 14) on the performance of an aerobic granular sludge (AGS) sequencing batch reactor (SBR) system operated with 6-h anaerobic-aerobic cycles for the treatment of a synthetic textile wastewater. In this sense, two SBRs inoculated with AGS from a domestic wastewater treatment plant were run in parallel, being one supplied with the dye and the other used as a dye-free control. The AGS successfully adapted to the new hydrodynamic conditions forming smaller, denser granules in both reactors, with optimal sludge volume index values of 19 and 17 mL g(-1) after 5-min and 30-min settling, respectively. As a result, high biomass concentration levels and sludge age values were registered, up to 13 gTSS L(-1) and 40 days, respectively, when deliberate biomass wastage was limited to the sampling needs. Stable dye removal yields above 90% were attained during the anaerobic reaction phase, confirmed by the formation of one of the aromatic amines arising from azo bond reduction. The control of the sludge retention time (SRT) to 15 days triggered a 30% reduction in the biodecolorization yield. However, the increase of the SRT values back to levels above 25 days reverted this effect and also promoted the complete bioconversion of the identified aromatic amine during the aerobic reaction phase. The dye and its breakdown products did not negatively affect the treatment performance, as organic load removal yields higher than 80% were attained in both reactors, up to 77% occurring in the anaerobic phase. These high anaerobic organic removal levels were correlated to an increase of Defluviicoccus-related glycogen accumulating organisms in the biomass. Also, the capacity of the system to deal with shocks of high dye concentration and organic load was successfully demonstrated. Granule breakup after long-term operation only occurred in the dye-free control SBR, suggesting that the azo dye plays an important role in improving granule stability. Fluorescence in situ hybridization (FISH) analysis confirmed the compact structure of the dye-fed granules, microbial activity being apparently maintained in the granule core, as opposed to the dye-free control. These findings support the potential application of the AGS technology for textile wastewater treatment.


Subject(s)
Azo Compounds/metabolism , Bioreactors , Rhodospirillaceae/metabolism , Sewage/analysis , Waste Disposal, Fluid , Water Pollutants, Chemical/metabolism , Biological Oxygen Demand Analysis , Textile Industry , Wastewater/analysis
18.
Front Cell Neurosci ; 9: 521, 2015.
Article in English | MEDLINE | ID: mdl-26834566

ABSTRACT

Recent studies combining pharmacological, behavioral, electrophysiological and molecular approaches indicate that depression results from maladaptive neuroplastic processes occurring in defined frontolimbic circuits responsible for emotional processing such as the prefrontal cortex, hippocampus, amygdala and ventral striatum. However, the exact mechanisms controlling synaptic plasticity that are disrupted to trigger depressive conditions have not been elucidated. Since glial cells (astrocytes and microglia) tightly and dynamically interact with synapses, engaging a bi-directional communication critical for the processing of synaptic information, we now revisit the role of glial cells in the etiology of depression focusing on a dysfunction of the "quad-partite" synapse. This interest is supported by the observations that depressive-like conditions are associated with a decreased density and hypofunction of astrocytes and with an increased microglia "activation" in frontolimbic regions, which is expected to contribute for the synaptic dysfunction present in depression. Furthermore, the traditional culprits of depression (glucocorticoids, biogenic amines, brain-derived neurotrophic factor, BDNF) affect glia functioning, whereas antidepressant treatments (serotonin-selective reuptake inhibitors, SSRIs, electroshocks, deep brain stimulation) recover glia functioning. In this context of a quad-partite synapse, systems modulating glia-synapse bidirectional communication-such as the purinergic neuromodulation system operated by adenosine 5'-triphosphate (ATP) and adenosine-emerge as promising candidates to "re-normalize" synaptic function by combining direct synaptic effects with an ability to also control astrocyte and microglia function. This proposed triple action of purines to control aberrant synaptic function illustrates the rationale to consider the interference with glia dysfunction as a mechanism of action driving the design of future pharmacological tools to manage depression.

19.
São Paulo; s.n; 2012. 93 p. ilus, tab. (BR).
Thesis in Portuguese | LILACS, BBO - Dentistry | ID: lil-695608

ABSTRACT

Objetivo: Investigar in situ a influência de materiais bioativos sobre a superfície do esmalte e dentina clareados, utilizando o teste de dureza Knoop (KHN), microscópio por emissão de campo (FEG) e quantificação do conteúdo mineral por fluorescência do substrato dental (QLF). Material e Métodos: Vinte molares humanos intactos foram selecionados. Para KHN e FEG, foram necessários 10 dentes. Foram obtidos 6 espécimes da porção cervical de cada dente, contendo esmalte e dentina, e distribuídos entre os 5 grupos experimentais, mais um controle (n=10). O grupo controle (sem tratamento) foi utilizado para o FEG, pois neste tipo de análise há destruição da amostra, não sendo possível a utilização de um mesmo espécime para obtenção de imagens nas fases antes e após o tratamento. Para o teste de dureza, as fatias tiveram os valores iniciais de dureza do esmalte e dentina medidos. Para o QLF, foram usados outros 10 dentes. Cada um foi seccionado em 5 fragmentos de esmalte superficial, retirados da porção coronária de cada dente. Metade de cada espécime foi protegida com verniz e a outra metade serviu para entrar em contato com os diversos tratamentos. Os fragmentos tiveram a quantificação mineral inicial medida pelo QLF. Todos os espécimes foram montados em retentores palatinos intraorais e usados por 10 voluntários durante 24h/dia, por 14 dias. Em cada dispositivo, eram aplicados os 5 diferentes tratamentos: 1: Opal, tratamento clareador com peróxido de carbamida (PC) 15% - Opalescence PF, Ultradent; 2: NiteWhite ACP, PC16% (Philips); 3: Opal + Bio (Biosilicato®, Vitrovita) misturados; 4: Opal Bio (Biosilicato® aplicado por 5 min, 1 vez por semana após clareamento); 5: Opal Rel ACP, Relief ACP (Philips) aplicado por 30 min por dia após clareamento. Em seguida, foram realizadas análises finais de KHN, FEG e QLF. Resultados: A análise estatística revelou que no grupo Opal houve redução significante dos valores de dureza em esmalte. No grupo Opal Bio, a aplicação do material bioativo não foi capaz de evitar a desmineralização do esmalte. Para os demais grupos, não houve alteração dos valores de dureza. Na dentina, o grupo Opal também causou diminuição na dureza. Nos grupos Opal Bio e Opal Rel ACP, a aplicação dos dois materiais bioativos não foi suficiente para evitar diminuição dos valores de dureza em dentina. Já nos grupos NW ACP e Opal + Bio, não foi observada desmineralização desse substrato. Os dados de dureza refletem os resultados observados na análise ultraestrutural do esmalte e da dentina, em que os grupos NW ACP e Opal + Bio apresentaram os melhores desempenhos em relação aos demais grupos. A análise por QLF não apresentou sensibilidade para detectar diferenças estatisticamente significantes entre os grupos e nem entre as fases inicial e final em nenhum dos grupos. Conclusão: No grupo Opal, observa-se desmineralização do esmalte e dentina clareados. A aplicação de Biosilicato® 1x por semana não foi suficiente para evitar alterações em esmalte e dentina. Relief ACP, aplicado diariamente após o tratamento clareador, foi capaz de evitar alterações em esmalte, mas não em dentina. A mistura de um gel clareador com um agente bioativo, como acontece nos grupos NW ACP e Opal + Bio, teve influência positiva em relação à dureza e morfologia da estrutura dental evitando sua desmineralização; nesses dois grupos, foram observados os melhores resultados tanto de dureza, quanto na análise ultraestrutural.


Objective: To Investigate in situ the influence of bioactive materials on whitened enamel and dentin surfaces using Knoop hardness test (KHN), field emission microscope (FEG) and quantitative light-induced fluorescence (QLF). Material and Methods: Twenty intact human molars were selected. Ten teeth for KHN and FEG were used. Six specimens were obtained from the cervical portion of each tooth, containing enamel and dentin. The slices were distributed into five experimental groups and one control (n=10). The control group (no treatment) was used for the FEG images, as this type of analysis destroys the sample, making it impossible to use the same specimens for before and after treatment images. For the hardness test, the enamel and dentin baseline Knoop hardness were measured for each slice for the control group and the five experimental groups. For QLF the other 10 teeth were used, each one sectioned into 5 superficial enamel slices. Half of each specimen was protected with varnish and the other half used to be in contact with the different treatments. The specimens had their baseline mineral content values measured by QLF. All specimens were mounted on intra-oral palatal retainers, which were used by 10 volunteers during 24h/day for 14 days. On each retainer five different treatments were applied: 1: Opal, whitening treatment (WT) with Opalescence PF, 15% carbamide peroxide (CP) (Ultradent); 2: NW ACP, whitening treatment with NiteWhite ACP, 16% CP (Philips); 3: Opal + Bio (Biosilicate®, Vitrovita) mixed; 4: Opal Bio (Biosilicate® applied for 5 minutes once a week after WT; 5: Opal Rel ACP, Relief ACP (Philips) applied 30 min per day after WT. Afterward, further KHN, FEG and QLF analysis were performed. Results: A statistical analyses revealed that the Opal group had a significant enamel hardness decrease. In the Opal Bio group, the application of the bioactive material was not able to prevent enamel demineralization.


Subject(s)
Biocompatible Materials , Tooth Bleaching , Dental Enamel , Dentin/physiology , Tooth Demineralization/diagnosis , Dental Enamel/physiology
20.
Am J Dent ; 24(3): 131-7, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21874930

ABSTRACT

PURPOSE: To investigate the influence of calcium phosphate enhanced home whitening agents on human enamel and dentin surface microhardness and ultramorphology. METHODS: Five intact molars crowns were used for ultrastructural analysis and five for microhardness test. Each resulting coronal structure was cut in slices. After measuring baseline Knoop Hardness Number (KHN) of the enamel and dentin, the slices were divided into six experimental groups and one control (n= 5). G1= 15% carbamide peroxide (CP); G2= 16% CP; G3= Ca and PO4 (remineralizing agent); G4= 16% CP with Ca and PO4; G5= 7.5% hydrogen peroxide (HP) with Ca and PO4; G6=7.5% HP with Ca. After each daily session of treatment, specimens were stored in distilled water (37 degrees C) until the next session. Products were applied for 2 weeks, according to manufacturers' instructions. Additional KHN weredetermined. RESULTS: Conventional whitening agents (G1; G2) and the gel with Ca (G6), caused KHN decrease (P< 0.05).The remineralizing and whitening agents with Ca and PO4 (G3; G4; G5) did not change KHN. A change of morphology was observed on enamel and dentin surfaces in G1; G2; G5.


Subject(s)
Dental Enamel/drug effects , Dentin/drug effects , Tooth Bleaching Agents/pharmacology , Tooth Remineralization/methods , Calcium Phosphates/pharmacology , Carbamide Peroxide , Dental Enamel/ultrastructure , Dental Enamel Solubility/drug effects , Dentin/ultrastructure , Dentin Solubility/drug effects , Gels , Hardness , Humans , Hydrogen Peroxide/pharmacology , Hydrogen-Ion Concentration , Materials Testing , Microscopy, Electron, Scanning , Peroxides/pharmacology , Temperature , Urea/analogs & derivatives , Urea/pharmacology , Water/chemistry
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