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1.
Environ Res ; 212(Pt C): 113396, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35525292

RESUMEN

Literature is scarce on the performance of Fenton-based processes as post-treatment of municipal wastewater treated by upflow anaerobic sludge blanket (UASB) reactor. This study aims to perform Fenton and photo-Fenton from UASB influent and effluent matrices to remove micropollutants (MPs) models: atrazine (ATZ), rifampicin (RIF), and 17α-ethynylestradiol (EE2). A UASB reactor at bench-scale (14 L) was operated with these MPs, and the AOPs experiments at bench-scale were performed on a conventional photochemical reactor (1 L). A high-pressure vapor mercury lamp was used for photo-Fenton process (UVA-Vis) as a radiation source. Microcrustacean Daphnia magna (acute toxicity) and seeds of Lactuca sativa (phytotoxicity) were indicator organisms for toxicity monitoring. The UASB reactor showed stability removing 90% of the mean chemical oxygen demand, and removal efficiencies for ATZ, RIF, and EE2 were 16.5%, 45.9%, and 15.7%, respectively. A matrix effect was noted regarding the application of both Fenton and photo-Fenton in UASB influent and effluent to remove MPs and toxicity responses. The pesticide ATZ was the most recalcitrant compound, yet the processes carried out from UASB effluent achieved removal >99.99%. The post-treatment of the UASB reactor by photo-Fenton removed acute toxicity in D. magna for all treatment times. However, only the photo-Fenton conducted for 90 min did not result in a phytotoxic effect in L. sativa.


Asunto(s)
Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Anaerobiosis , Reactores Biológicos , Aguas del Alcantarillado/química , Aguas Residuales
2.
Altern Ther Health Med ; 27(2): 22-26, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33711819

RESUMEN

BACKGROUND: Auricular acupuncture (AA) is a complementary/integrative therapy, and can be used as adjuvant treatment in sleep disorders, anxiety and the painful symptomatology of temporomandibular disorders (TMDs). OBJECTIVE: The aim of this investigation was to evaluate the effectiveness of AA in reducing the symptoms of sleep disorders, anxiety and TMDs by applying the Fletcher and Luckett, Beck-BAI and RDC/TMD questionnaires: Axis II, respectively. DESIGN: This was a nonrandomized clinical trial in which AA was administered to patients between the ages of 20 and 45 years from the School of Dentistry at Ribeirão Preto, São Paolo, Brazil, who had at least one of the following: sleep disorder, anxiety or TMD. INTERVENTION: Mustard seeds were applied to predetermined auricular acupoints including: Shen Men, neurovegetative system (sympathetic), kidney, anxiety, stomach, maxilla and mandible, liver and stress, once a week for 8 weeks. OUTCOME MEASURES: To analyze the reduction in sleep disorder symptoms, we used the Fletcher and Luckett questionnaire; for anxiety symptoms, the Beck-BAI questionnaire, and for the degree of chronic TMD pain, the RDC/TMD (Axis II) questionnaire. RESULTS: Data on sleep, anxiety and TMD disorders were analyzed via Fisher's exact, Wilcoxon and Chi-Square non-parametric tests (α = 0.05), respectively. Reduction in sleep disorder symptoms after the proposed intervention was verified, showed a statistically significant difference (P = .014). There was a reduction in mean anxiety score and a decrease in painful TMD symptoms, but no significant difference (P = .50; P = .947, respectively) before and after AA. CONCLUSION: In our study, AA was effective in reducing sleep disorder symptoms and our data suggests some relief of symptoms of anxiety and TMD pain.


Asunto(s)
Acupuntura Auricular , Trastornos del Sueño-Vigilia , Trastornos de la Articulación Temporomandibular , Adulto , Ansiedad/terapia , Trastornos de Ansiedad , Brasil , Depresión , Humanos , Masculino , Persona de Mediana Edad , Sueño , Trastornos del Sueño-Vigilia/terapia , Trastornos de la Articulación Temporomandibular/terapia , Adulto Joven
3.
J Prosthet Dent ; 123(3): 529.e1-529.e5, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31952862

RESUMEN

STATEMENT OF PROBLEM: Dental porcelain restorations are subject to biological failures related to secondary caries and periodontal disease leading to prosthesis replacement. PURPOSE: The purpose of this in vitro study was to explore the microbiological and mechanical properties of dental porcelain incorporated with different percentages of silver vanadate (ß-AgVO3) through microbiological analysis, roughness tests, and the Vickers microhardness test. MATERIAL AND METHODS: IPS InLine porcelain specimens were made by using a cylindrical Teflon matrix in the dimensions of 8×2 mm. For the control group, the porcelain was manipulated according to the manufacturer's instructions. The groups incorporating the nanomaterial were prepared with 2.5%, 5%, and 10% of ß-AgVO3, which was added proportionally by mass to the porcelain powder. In vitro microbiologic analysis, roughness tests, and the Vickers microhardness test were performed. RESULTS: Against Streptococcus mutans, the control group showed no inhibition halo (0 mm). All groups with AgVO3 showed a zone of inhibition, the highest for the group with 10% (30 mm) and then the groups with 2.5% (9 mm) and 5% (17 mm). For Vickers microhardness, no statistically significant difference (P<.05) was observed between the evaluated groups. The group with 10% of AgVO3 had the highest mean roughness and was statistically different (P<.001) from the other groups. CONCLUSIONS: Adding ß-AgVO3 to dental porcelain demonstrated antimicrobial effectiveness at all concentrations (2.5%, 5%, and 10%), with no effect on Vickers microhardness. The 10% group had higher roughness than the other groups.


Asunto(s)
Porcelana Dental , Nanoestructuras , Ensayo de Materiales , Plata , Streptococcus mutans , Propiedades de Superficie
4.
J Relig Health ; 59(3): 1626-1634, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31696376

RESUMEN

Anxiety and sleep disorders are highly prevalent affecting millions of people worldwide. Complementary therapies like art therapy, bibliotherapy, and music have been used to manage these problems. The objective of this study was to evaluate levels of anxiety and sleep disorder symptoms of participants before and after a 30-day intervention of listening to short poetic audios. Thirty-one participants listened to audio-taped messages, which associate music and literature for 30 days. Questionnaires were answered by participants prior to the start of the study (baseline collection) and after 30 days (final collection). Setting: the study was done in the city of Ribeirao Preto (Sao Paulo-Brazil). Participants were 31 adults with anxiety symptoms and sleep problems. The scores of the questionnaires were analyzed and compared by the t test for paired samples (α = 0.05), used to evaluate possible differences in anxiety and stress symptoms and sleep disturbances before and after the 30 days of intervention. Significantly lower levels of anxiety and sleep disorders were found after the 30-day intervention. This study reinforces the benefits of music and literature for improving the quality of life of people by reducing levels of anxiety and sleep disorder symptoms.


Asunto(s)
Ansiedad/terapia , Musicoterapia , Calidad de Vida/psicología , Trastornos del Sueño-Vigilia/terapia , Adulto , Ansiedad/psicología , Brasil , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Procesos y Resultados en Atención de Salud
5.
J Environ Sci Health B ; 52(1): 48-58, 2017 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-27726598

RESUMEN

The Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was applied to the extraction of 14 organochlorine pesticides (OCPs) residues from commercial fruit pulps available in supermarkets in Fortaleza, Northeastern Brazil. The analyses were carried out by gas chromatography (GC), coupled to an electron-capture detector (ECD), and were confirmed by GC-tandem mass spectrometry (MS). The parameters of the analytical method, such as accuracy, precision, linear range, limits of detection and quantification, were determined for each pesticide. The results showed good linearity (R2 ≥ 0.9916) and the overall average recoveries were considered satisfactory obtaining values between 69 and 110%, RSD of 2-15 %, except for hexachlorobenzene (HCB) in açai, acerola and guava pulp samples. The OCPs were detected in guava (α-HCH; lindane) and soursop (α, ß-HCH isomers) samples. The QuEChERS method and GC-ECD were successfully used to analyze OCPs in commercially available Brazilian fruit pulps and can be applied in routine analytical laboratories.


Asunto(s)
Contaminación de Alimentos/análisis , Frutas/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Plaguicidas/análisis , Espectrometría de Masas en Tándem/métodos , Brasil , Euterpe/química , Análisis de los Alimentos/métodos , Hexaclorociclohexano/análisis , Hidrocarburos Clorados/análisis , Residuos de Plaguicidas/análisis , Psidium/química
6.
Environ Technol ; 35(13-16): 1711-20, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24956762

RESUMEN

This work investigates copper, nickel and zinc ion biosorption in single- and multi-component systems in a fixed-bed column using green coconut shells (CS). Approximately 85% of biosorbents are in a particle size ranging from 0.25 to 2 mm. Operational parameters selected include a flow rate of 200 mL min-1 and a bed height of 100 cm, which were selected for a shorter execution time and good adsorption capacity. Empty-bed contact time and Thomas models were applied, showing a good fit with the experimental data. The column adsorption capacity increased after the green CS powder was treated in a column with NaOH at a concentration of 0.1 mol L-1. The highest values of adsorption capacities founded were 0.69, 0.45 and 0.39 mmol L-1 for Cu(II), Ni(II) and Zn(Il), respectively, using green CS treated inside a column with NaOH of 0.1 M. The pH and chemical oxygen demand were monitored in the treatment solution and indicated that the adjustment of these parameters is necessary before disposal of these solutions. A study of desorption using an acid solution was carried out for recovery of metal ions.


Asunto(s)
Cocos/química , Metales Pesados/química , Contaminantes Químicos del Agua/química , Purificación del Agua/instrumentación , Adsorción , Análisis de la Demanda Biológica de Oxígeno , Concentración de Iones de Hidrógeno , Proyectos Piloto
7.
J Dent ; 143: 104825, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38157974

RESUMEN

OBJECTIVE: The possibility of making impressions of teeth prepared with a rubber dam in place has been proposed; however, this requires trimming and rescanning the mesh, which has been described as a cause of accuracy loss. This study aims to clinically determine whether overlay restorations obtained from a scan with a rubber dam in place have equivalent marginal fit, contact points, and occlusal fit to the same type of restorations obtained from a scan without a rubber dam. MATERIAL AND METHODS: Thirty patients who underwent overlay restoration of a molar with at least one neighbouring tooth were selected. After tooth preparation, two scans were performed: one without a rubber dam and the other with a rubber dam. Restorations were randomly created from one scan or another. The marginal fit, interproximal contact points, and occlusal fit were evaluated clinically. Two meshes, with and without rubber dams, were also compared. RESULTS: No significant differences were observed in the clinical evaluation of the overlays made of the two meshes. The trueness of the mesh from the impression made with a rubber dam with respect to the mesh without a rubber dam was about 40 µm in the critical areas of the preparation (margins, intaglio, and interproximal contact points). CONCLUSIONS: The results of this study show that under the conditions performed and with the equipment used, there are no significant clinical differences between overlay restorations made from a scan with a rubber dam and those made from a scan without a rubber dam. CLINICAL SIGNIFICANCE: Scanning with a rubber dam in place may be a valid option for certain types of restorations under certain clinical conditions.


Asunto(s)
Restauración Dental Permanente , Diente , Humanos , Diseño Asistido por Computadora , Restauración Dental Permanente/métodos , Diente Molar , Dique de Goma
8.
Cranio ; 41(4): 362-367, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33287687

RESUMEN

OBJECTIVE: The purpose of this study was to evaluatephotobiomodulation applied at auriculotherapy points forsleep disorder (SD) and anxiety related to temporomandibulardysfunction (TMD). METHODS: The study consisted of two groups of 20 participants: Auriculotherapy group (A) and Control Group(C). The participants responded to the RDC/TMD, Fletcher & Luckett questionnaires, and the Beck Anxiety Inventory to analyze TMD, SD, and anxiety before and after the treatment. RESULTS: The participants presented scores corresponding to mild to moderateanxiety (MDN = 17; CI = [13.16;22.31]) and after treatment, normalor non-existent anxiety (MDN = 9; CI = [8.76; 17.12]) (p = 0.005). There was no significant difference (p > 0.05) between the controland 20 auriculotherapy groups for TMD and SD. DISCUSSION: The results suggest that auriculotherapy was effective in the treatment of anxiety. However, it did not prove effective with the results of the SD and symptoms of TMD.


Asunto(s)
Auriculoterapia , Trastornos del Sueño-Vigilia , Trastornos de la Articulación Temporomandibular , Humanos , Trastornos de la Articulación Temporomandibular/radioterapia , Ansiedad/terapia , Trastornos de Ansiedad , Trastornos del Sueño-Vigilia/radioterapia , Sueño
9.
J Environ Manage ; 112: 178-85, 2012 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-22922136

RESUMEN

Various technologies have been used for the treatment and remediation of areas contaminated by BTEX (benzene, toluene, ethylbenzene and xylenes), which are organic compounds that are of particular concern due to their toxicity. Potential applications of synthetic zeolites for environmental fieldwork have also been reported worldwide. In this work, a hexadecyltrimethyl ammonium (HDTMA) surfactant-modified synthetic zeolite was investigated for its efficiency in removing BTEX from aqueous solutions. Three surfactant-modified zeolites were synthesized, with amounts of surfactant corresponding to 50%, 100%, and 200% of the total cation-exchange capacity (CEC) of the synthetic zeolite Y. The results of the BTEX adsorption experiments onto both synthetic zeolite and surfactant-modified zeolites (SMZ) showed that the SMZ-100 (zeolite modified with surfactant levels at 100% of CEC) was the most efficient modified zeolite for BTEX removal. Kinetics studies indicated that the multicomponent adsorption equilibrium was reached within 6 h and followed pseudo-second-order kinetics. The Langmuir, Freundlich, Redlich-Peterson and Temkin models were used to evaluate the BTEX adsorption capacity by SMZ-100. The Temkin model was found to be suitable for all BTEX compounds in a multicomponent system. Regeneration cycles of the modified zeolite were also performed, and the results showed that the adsorbent could be used efficiently in as many as four adsorption cycles, except for benzene.


Asunto(s)
Zeolitas/química , Adsorción , Benceno/química , Derivados del Benceno/química , Tensoactivos/química , Tolueno/química , Xilenos/química
10.
Antibiotics (Basel) ; 10(2)2021 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-33498278

RESUMEN

Biofilm formation on biomaterials is a challenge in the health area. Antimicrobial substances based on nanomaterials have been proposed to solve this problem. The aim was to incorporate nanostructured silver vanadate decorated with silver nanoparticles (ß-AgVO3) into dental porcelains (IPS Inline and Ex-3 Noritake), at concentrations of 2.5% and 5%, and evaluate the surface characteristics (by SEM/EDS), antimicrobial activity (against Streptococcus mutans, Streptococcus sobrinus, Aggregatibacter actinomycetemcomitans, and Pseudomonas aeruginosa), silver (Ag+) and vanadium (V4+/V5+) ions release, and mechanical properties (microhardness, roughness, and fracture toughness). The ß-AgVO3 incorporation did not alter the porcelain's components, reduced the S. mutans, S. sobrinus and A. actinomycetemcomitans viability, increased the fracture toughness of IPS Inline, the roughness for all groups, and did not affect the microhardness of the 5% group. Among all groups, IPS Inline 5% released more Ag+, and Ex-3 Noritake 2.5% released more V4+/V5+. It was concluded that the incorporation of ß-AgVO3 into dental porcelains promoted antimicrobial activity against S. mutans, S. sobrinus, and A. actinomycetemcomitans (preventing biofilm formation), caused a higher release of vanadium than silver ions, and an adequate mechanical behavior was observed. However, the incorporation of ß-AgVO3 did not reduce P. aeruginosa viability and increased the surface roughness of dental porcelains.

11.
Environ Sci Pollut Res Int ; 28(7): 8012-8021, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33044696

RESUMEN

Chemometric tools are powerful strategies to efficiently optimize many processes. These tools were employed to optimize a fast-solid phase microextraction procedure, which was used for the analysis of polycyclic aromatic hydrocarbons (PAHs) in oil-based produced water using a Headspace-Solid Phase Microextraction technique (HS-SPME/GC-MS). This optimization was achieved with a 24 factorial design approach, where the final conditions for this extraction procedure were 10 µg L-1, 1 h, 92 °C (at headspace), and 0.62 mol L-1 for PAHs concentration, fiber exposition to headspace, temperature, and NaCl concentration, respectively. The limit of detection (LOD) in this protocol ranged from 0.2 to 41.4 ng L-1, while recovery values from 67.65 to 113.10%. Besides that, relative standard deviation (RSD) were lower than 8.39% considering high molecular weight compounds. Moreover, the proposed methodology in this work does not require any previous treatment of the sample and allows to quantify a higher number of PAHs. Notably, naphthalene was the major PAHs compound quantified in all samples of the produced water at 99.99 µg L-1. Altogether, these results supported this methodology as a suitable analytical strategy for fast determination of PAHs in produced water from oil-based industry.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Cromatografía de Gases y Espectrometría de Masas , Hidrocarburos Policíclicos Aromáticos/análisis , Microextracción en Fase Sólida , Agua , Contaminantes Químicos del Agua/análisis
12.
ACS Omega ; 5(7): 3346-3357, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32118149

RESUMEN

Parabens are widely used as preservatives in food, pharmaceutical, and cosmetic products. These compounds are known for their estrogen agonist activity. This research investigates the synthesis of micro- and mesoporous silica from coal fly ash at different pH values (13, 11, 9, and 7) as well as its use as an adsorbent for the removal of parabens. The materials were characterized, and X-ray fluorescence (XRF) analysis revealed that the fly ash acid treatment reduced the presence of aluminum, iron, and calcium oxides and also that silica synthesized at lower pH values (7 and 9) showed a higher SiO2 content. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses revealed microporous silica formation for silica synthesized at pH 13 and mesoporous silica at pH 7, 9, and 11. Adsorption tests were performed with materials, and FA-AT7 showed a higher adsorption capacity. The effect of factors (A) adsorbent mass, (B) initial paraben concentration, and (C) agitation rate on the adsorption process was studied for the FA-AT7 adsorbent using a factorial experimental design. Standardized Pareto charts revealed a negative effect of factor A, positive effect of factor B, and negative interaction effects of factors A-B for all studied parabens. Isotherms and multicomponent kinetic studies were performed. A linear type-III isotherm was obtained, and adsorption equilibrium was reached at approximately 10 min.

13.
Iran Endod J ; 14(1): 7-13, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-36879594

RESUMEN

Introduction: The aim of this study was adding the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) (0, 2.5, 5, and 10%) to the endodontic sealers AH-Plus, Sealer 26 and Endomethasone N, and evaluate the antimicrobial activity, solubility and pH. Methods and Materials: The antimicrobial activity of freshly mixed sealers (n=10) and set sealers (n=9) against Enterococcus faecalis (E. faecalis) was evaluated by colony forming units per milliliter and epifluorescence microscopy. Solubility (n=9) and pH (n=10), 6 and 24 h and 7, 14, and 30 days were also evaluated. The Kruskal-Wallis and Dunn's post-test were applied for the antimicrobial activity of fresh sealers. ANOVA and Tukey's post-test was used for set sealers and solubility, and Friedman's two-way analysis of variance for pH (α=0.05). Results: The fresh sealers inhibited E. faecalis. Set Sealer 26 (5 and 10% AgVO3) and Endomethasone N (2.5, 5, and 10% AgVO3) presented higher activity then the corresponding controls. Modification with AgVO3 did not influence the solubility of AH Plus and Sealer 26, but Endomethasone N (5%) presented reduced solubility. The AH-Plus groups showed acidic pH, and Sealer 26, basic pH after 30 days. Endomethasone N (5 and 10% AgVO3) presented statistical difference compared to 0% (P<0.05). Conclusion: In this in vitro study all fresh sealers and set Sealer 26 (5 and 10%) and Endomethasone N (2.5, 5, and 10%) presented higher antimicrobial activity than controls. The modification with 5% and 10% AgVO3 decreased solubility and pH of Endomethasone N, but did not affect the other groups.

14.
J Conserv Dent ; 20(6): 392-397, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29430089

RESUMEN

OBJECTIVES: The objective of the study is to incorporate the nanostructured silver vanadate (AgVO3) decorated with silver nanoparticles at endodontic sealers AH Plus, Sealapex, Sealer 26, and Endofill, at concentrations of 2.5%, 5%, and 10%, and to evaluate physical-chemical properties. MATERIALS AND METHODS: The study was to evaluate the radiopacity using digital radiography (n = 5), the tooth color change in 48 incisors (n = 3) for 7, 30, 90, and 180 days in a spectrophotometer, and the topographic distribution in a confocal laser (n = 5). The radiopacity was analyzed by Kruskal-Wallis test and the permutation (α = 0.05) and the color and topographical distribution by descriptive statistical analysis. RESULTS: The AgVO3 had no effect on the radiopacity of Endofill and Sealapex (P > 0.05) and at 2.5% concentrations increased the radiopacity of Sealer 26 and AH Plus (P < 0.05). The Endofill 10% showed less color change, and the major changes were the modified groups in 180 days. The AgVO3 showed a circular topographic distribution in areas of the sealers. CONCLUSION: It was found that the addition of AgVO3 did not affect the radiopacity of Endofill and Sealapex however, increased the radipacity of Sealer 26 and AH Plus. For modified groups, the greatest color change was promoted after 180 days, except for Endofill with 10%. Topographic distribution of nanomaterial affected the color change of theevaluated sealers.

15.
Eur Endod J ; 2(1): 1-6, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-33403330

RESUMEN

OBJECTIVE: This preliminary study aimed to evaluate the antimicrobial activity, flow and radiopacity of endodontic sealers with nanostructured silver vanadate decorated with silver nanoparticles (AgVO3). METHODS: The minimum inhibitory concentration (MIC) of AgVO3 was evaluated against Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. Specimens were prepared from the following endodontic sealers: AH Plus (DENTSPLY DeTrey GmbH, Konstanz, Germany), Sealapex (Sybron Endo, Orange, CA, USA), Sealer 26 (DENTSPLY, Petrópolis, Brazil) and Endofill (DENTSPLY, Petrópolis, Brazil), with concentrations of 0%, 2.5%, 5% and 10% of AgVO3. Agar diffusion was used to evaluate the materials after 48 hours and 7 days (n=6). Flow (n=6) and radiopacity (n=9) were evaluated. The data were analysed by analysis of variance (ANOVA) and the Tukey honestly significant difference (HSD) (α=0.05). RESULTS: The MIC of AgVO3 was 500 µg/mL for E. faecalis and 31.25 µg/mL for P. aeruginosa and E. coli. The AgVO3 did not influence the antimicrobial activity of AH Plus against E. faecalis (P>0.05) but did promote this activity for Sealapex (P<0.01). Moreover, this activity increased for Endofill from 2.5% and for Sealer 26 from 5% (P<0.05). Against P. aeruginosa, only AH Plus and Endofill 10% inhibited zone formation (P<0.01). The antimicrobial activity of Endofill increased from 2.5% against E. coli (P<0.01). Sealapex 5% and 10% (P<0.01), Sealer 26 10% and AH Plus promoted antimicrobial activity against E. coli. An increase in the zone of inhibition occurred between 48 hours and 7 days in the Sealapex 10% and Endofill 5% groups against E. coli. The flow of AH Plus and Endofill decreased with the increase of AgVO3 (P<0.05), and the flow of Sealer 26 and Sealapex was not affected (P>0.05). The radiopacity of AH Plus increased with AgVO3 (P<0.05). Endofill 5% and 10% did not differ from the control Endofill (P>0.05). The incorporation of AgVO3 did not influence the radiopacity of Sealer 26 (P>0.05). The incorporation of 2.5% and 5% AgVO3 reduced the radiopacity of Sealapex (P<0.05). CONCLUSION: Adding AgVO3 may increase the antimicrobial effect of endodontic sealers without major changes in their physicochemical properties.

16.
Environ Technol ; 37(17): 2157-71, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26950526

RESUMEN

Buriti fibers were subjected to an alkaline pre-treatment and tested as an adsorbent to investigate the adsorption of copper, cadmium, lead and nickel in mono- and multi-element aqueous solutions, the results showed an increase in the adsorption capacity compared to the unmodified Buriti fiber. The effects of pH, adsorbent mass, agitation rate and initial metal ions concentration on the efficiency of the adsorption process were studied using a fractional 2(4-1) factorial design, and the results showed that all four parameters influenced metal adsorption differently. Fourier transform infrared spectrometry and X-ray fluorescence analysis were used to identify the groups that participated in the adsorption process and suggest its mechanisms and they indicated the probable mechanisms involved in the adsorption process are mainly ion exchange. Kinetic and thermodynamic equilibrium parameters were determined. The adsorption kinetics were adjusted to the homogeneous diffusion model. The adsorption equilibrium was reached in 30 min for Cu(2+) and Pb(2+), 20 min for Ni(2+) and instantaneously for Cd(2+). The results showed a significant difference was found in the competitiveness for the adsorption sites. A mathematical model was used to simulate the breakthrough curves in multi-element column adsorption considering the influences of external mass transfer and intraparticle diffusion resistance.


Asunto(s)
Arecaceae/química , Simulación por Computador , Metales/metabolismo , Contaminantes Químicos del Agua/metabolismo , Adsorción , Cinética , Metales/análisis , Metales/química , Proyectos de Investigación , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Purificación del Agua
17.
J Colloid Interface Sci ; 449: 180-91, 2015 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-25527089

RESUMEN

Wood-based activated carbon and its sulfur-doped counterpart were used as adsorbents of endocrine disruptor chemicals (EDC) from aqueous solution. Adsorption process was carried out in dynamic conditions and Thomas model was used to predict the performance of the column. The results showed a good fitting of the theoretical curve to the experimental data. S-doped carbon exhibited a higher adsorption capacity of trimethoprim (TMP) and smaller of sulfamethoxazole (SMX) and diclofenac (DCF) in comparison with the carbon with no sulfur incorporated into the matrix. The surface features of the initial carbons and those exposed to EDC were evaluated in order to derive the adsorption mechanism and elucidate the role of surface features. An increase in the amount of TMP from a low concentration solution (10 mg/L) on sulfur-doped carbon was linked to acid-base interactions and the reactive adsorption/oxidation of TMP. A decrease in SMX and DCF after sulfur doping was explained by a considerable increase in surface hydrophobicity, which does not favor the retention of polar DCF and SMX molecules. When the adsorption was measured from a high concentration solution at equilibrium conditions at the dark or under solar light irradiation different trends in the adsorption capacities were found. This was linked to the photoactivity of carbons and the degradation of EDC in the pore system promoted by visible light followed by the adsorption of the products of surface reactions.


Asunto(s)
Carbón Orgánico/química , Disruptores Endocrinos/aislamiento & purificación , Nanoestructuras/química , Azufre/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Luz , Modelos Moleculares , Oxidación-Reducción , Fotólisis , Porosidad , Propiedades de Superficie , Agua/análisis , Contaminación Química del Agua/análisis
18.
Sci Total Environ ; 490: 288-95, 2014 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-24858226

RESUMEN

This paper evaluated the occurrence and removal efficiency of four estrogenic hormones in five biological wastewater treatment plants (WWTPs), located in the State of Ceará, Brazil. The five WWTPs comprised: two systems consisted of one facultative pond followed by two maturation ponds, one facultative pond, one activated sludge (AS) system followed by a chlorination step, and one upflow anaerobic sludge blanket (UASB) reactor followed by a chlorination step. Estrogen occurrence showed a wide variation among the analyzed influent and effluent samples. Estrone (E1) showed the highest occurrence in the influent (76%), whereas both 17ß-estradiol (E2) and 17α-ethynylestradiol (EE2) presented a 52% occurrence, and the compound 17ß-estradiol 17-acetate (E2-17A), a 32% one. The occurrence in the effluent samples was 48% for E1, 28% for E2, 12% for E2-17A, and 40% for EE2. The highest concentrations of E1 and EE2 hormones in the influent were 3050 and 3180 ng L(-1), respectively, whereas E2 and E2-17A had maximum concentrations of 776 and 2300 ng L(-1), respectively. The lowest efficiencies for the removal of estrogenic hormones were found in WWTP consisted of waste stabilization ponds, ranging from 54 to 79.9%. The high-rate systems (AS and UASB), which have chlorination as post-treatment, presented removal efficiencies of approximately 95%.


Asunto(s)
Estrógenos/análisis , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Brasil , Disruptores Endocrinos/análisis , Estradiol/análogos & derivados , Estradiol/análisis , Estrona/análisis , Etinilestradiol/análisis , Eliminación de Residuos Líquidos/estadística & datos numéricos , Aguas Residuales/estadística & datos numéricos
19.
Int J Pediatr Otorhinolaryngol ; 78(10): 1592-8, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25085074

RESUMEN

OBJECTIVES: Investigation sought to determine whether there is any acoustic variable to objectively differentiate gender in children with normal voices. METHODS: A total of 30 children, 15 boys and 15 girls, with perceptually normal voices were examined. They were between 7 and 10 years old (mean: 8.1, SD: 0.7 years). Subjects were required to perform the following phonatory tasks: (1) to phonate sustained vowels [a:], [i:], [u:], (2) to read a phonetically balanced text, and (3) to sing a song. Acoustic analysis included long-term average spectrum (LTAS), fundamental frequency (F0), speaking fundamental frequency (SFF), equivalent continuous sound level (Leq), linear predictive code (LPC) to obtain formant frequencies, perturbation measures, harmonic to noise ratio (HNR), and Cepstral peak prominence (CPP). Auditory perceptual analysis was performed by four blinded judges to determine gender. RESULTS: No significant gender-related differences were found for most acoustic variables. Perceptual assessment showed good intra and inter rater reliability for gender. Cepstrum for [a:], alpha ratio in text, shimmer for [i:], F3 in [a:], and F3 in [i:], were the parameters that composed the multivariate logistic regression model to best differentiate male and female children's voices. CONCLUSION: Since perceptual assessment reliably detected gender, it is likely that other acoustic markers (not evaluated in the present study) are able to make clearer gender differences. For example, gender-specific patterns of intonation may be a more accurate feature for differentiating gender in children's voices.


Asunto(s)
Caracteres Sexuales , Canto , Acústica del Lenguaje , Voz , Biomarcadores , Niño , Femenino , Humanos , Modelos Logísticos , Masculino , Fonética , Reproducibilidad de los Resultados
20.
Eng. sanit. ambient ; 24(4): 667-673, jul.-ago. 2019. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1039784

RESUMEN

ABSTRACT The present paper aimed to evaluate the impact of microaeration on both the removal performance of some emerging micropollutants (pharmaceuticals, hormones, and bisphenol A) and the microbial community structure of an anaerobic reactor treating synthetic wastewater. Under anaerobic conditions, the removal efficiencies of the micropollutants were very low (< 10%). However, the microaeration (1.0 mL air·min-1 at 27 °C and 1 atm, equivalent to a QAIR/QINF ratio of 0.1) expressively improved the removal efficiencies of all compounds (> 50%). Therefore, supplementing anaerobic reactors with low amounts of oxygen seems to be an interesting strategy to enhance the removal of the micropollutants tested. However, further studies should be carried out with other compounds in order to evaluate the wide applicability of microaeration to different classes of micropollutants in lab- and full-scale treatment systems. Concerning the microbiota structure, both bacterial and archaeal communities were not compromised by the different operational conditions and preserved their functional organization with high richness during the whole experiment.


RESUMO O presente trabalho teve como objetivo avaliar o impacto da microaeração tanto no desempenho de remoção de alguns micropoluentes emergentes (fármacos, hormônios e bisfenol A) quanto na estrutura da comunidade microbiana de um reator anaeróbio tratando uma água residuária sintética. Sob condições anaeróbias, as eficiências de remoção dos micropoluentes foram muito baixas (< 10%). Entretanto, a microaeração (1,0 mL de ar·min-1 a 27 °C e 1 atm, equivalente a uma relação QAR/QAF de 0,1) melhorou expressivamente as eficiências de remoção de todos os compostos (> 50%). Portanto, a suplementação de reatores anaeróbios com baixas quantidades de oxigênio parece ser uma estratégia interessante para melhorar a remoção dos micropoluentes testados. Entretanto, mais estudos devem ser realizados com outros compostos para avaliar a ampla aplicabilidade da microaeração a diferentes classes de micropoluentes em sistemas de tratamento em escala laboratorial e real. Com relação à estrutura da microbiota, tanto as comunidades de bactérias quanto as de arqueias não foram comprometidas pelas diferentes condições operacionais e preservaram sua organização funcional com elevada riqueza durante todo o experimento.

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