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1.
BMJ Case Rep ; 14(5)2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016625

RESUMO

A 22-year old construction worker was shot with a fishing harpoon gun on the left side of his face. He consulted at the emergency room 12 days postinjury, stable but with blurring of vision on the right. The shaft of the harpoon was protruding at the left preauricular area; the tip was neither visible nor palpable. Craniofacial CT scan and skull anteroposterolateral radiographs revealed the tip of the harpoon to be at the right orbital apex. A hook attached 1 cm from the tip was lodged in the sphenoid sinus. The hook was dismantled from the shaft via a combined external and endoscopic transnasal approach, enabling the shaft to be gently pulled. The hook, together with the tip, were removed endoscopically. The patient's visual acuity improved. He was discharged after 2 days on oral antibiotics with no deficits on follow-up.


Assuntos
Endoscopia , Seio Esfenoidal , Adulto , Diamante , Humanos , Masculino , Seio Esfenoidal/diagnóstico por imagem , Seio Esfenoidal/cirurgia , Tomografia Computadorizada por Raios X , Transtornos da Visão , Adulto Jovem
2.
Environ Monit Assess ; 193(6): 337, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33982183

RESUMO

The most severe disturbance of the earth's surface occurs when the open-cut method of mineral deposits mining is used. The geoecological situation was assessed based on the nature of the soil cover based on the example of an industrial site of a diamond mining and processing plant located in the permafrost zone. During the period from 2007 to 2018, the soil cover of the industrial site is characterized by polyelement contamination. In the surface, soil horizons were an increase in the concentrations of mobile forms of Mn, Zn, Cd, Cr, Co, and Ni. It is identified that AO, ABcr, and CR are the accumulation horizons if the soil profile is preserved. Mobile forms Mn, Zn, Ni, Cr, Co, and As can migrate along with the soil profile to a depth of 40-50 cm depending on the amount of soil organic matter, the degree of its decomposition, and the scale of the cryoturbation. Research in 2018 allowed us to localize and confirm the increase in the area of contamination of the industrial site. Areas with an extremely dangerous category of soil cover contamination increased by 3 times compared to 2014. The results obtained are the basis for a more detailed study of the horizons of geochemical accumulation and the creation of artificial geochemical barriers with the development of technologies for the subsequent extraction of useful components.


Assuntos
Metais Pesados , Poluentes do Solo , Diamante , Monitoramento Ambiental , Metais Pesados/análise , Federação Russa , Solo , Poluentes do Solo/análise
3.
Chemosphere ; 279: 130525, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33866102

RESUMO

This work focuses on the treatment of gaseous perchloroethylene (PCE) using electro-scrubbing with diamond electrodes and cobalt mediators. PCE was obtained by direct desorption from an aqueous solution containing 150 mg L-1, trying to a real pollution case. The electro-scrubber consisted of a packed absorption column connected with an undivided electrochemical cell. Diamond anodes supported on two different substrates (tantalum and silicon) were used and the results indicated that Ta/BDD was more successful in the production of Co (III) species and in the degradation of PCE. Three experimental systems were studied for comparison purposes: absorbent free of Co (III) precursors, absorbent containing Co (III) precursors, and absorbent containing Co (III) precursors undergoing previous electrolysis to the electro-scrubbing to facilitate the accumulation of oxidants. The most successful option was the last, confirming the important role of mediated electrochemical processes in the degradation of PCE. Trichloroacetic acid (TCA) and carbon tetrachloride (CCl4) were found as the primary reaction products and ethyl chloroacetate esters were also identified. A comprehensive mechanism of the processes happening inside electro-scrubber is proposed.


Assuntos
Tetracloroetileno , Poluentes Químicos da Água , Cobalto , Diamante , Eletrodos , Eletrólise , Gases , Oxirredução
4.
Chemosphere ; 278: 130488, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33839390

RESUMO

The construction of a photoanode with several layers of titanium oxysulfate as a precursor to form titanium dioxide-TiO2 on boron doped diamond-BDD (TiO2/BDD), and its application for the photoelectro-degradation of glyphosate in aqueous medium are presented. The study was divided into three stages: i) optimization of the number of layers of the TiO2 precursor to modify BDD using a novel method combining Sol-gel/Spin-Coating; ii) characterization of the TiO2/BDD electrodes, by scanning electron microscopy-SEM, dispersive energy spectroscopy-EDX, Ray diffraction-XRD, contact angle, and electrochemical response by cyclic voltammetry using [Fe(CN)6]3-/4- system; iii) degradation of glyphosate (50 mg L-1) by electrochemical oxidation on BDD and photoelectrocatalysis on TiO2/BDD in dark and UV-light conditions, at different current densities, for 5 h. The glyphosate degradation and mineralization were evaluated by High-Performance Liquid Chromatography, Total Organic Carbon, Chemical Oxygen Demand and inorganic-ions concentration (NO3-, PO43-, and NH4+). Also, the aminomethylphosphonic acid-AMPA was quantified by HPLC, as a degradation intermediate. Using five layers of the TiO2 precursor, in the construction of TiO2/BDD photoanode, and a lower contact angle, greater photoelectrocatalysis against the [Fe(CN)6]3-/4- redox system and better degradation of glyphosate compared to BDD without modification were achieved. The formation of TiO2 nanoparticles (14.79 ± 3.43 nm) in anatase phase on BDD was verified by SEM and XRD. Additionally, glyphosate degradation and mineralization were 2.3 times faster by photoelectrocatalysis on TiO2/BDD, relative to BDD, at 3 mA cm-2 and UV-light. Thus, the presence of TiO2 on BDD increases the rate and efficiency of glyphosate degradation with respect to electrochemical oxidation on BDD.


Assuntos
Diamante , Poluentes Químicos da Água , Boro , Dioxóis , Eletrodos , Glicina/análogos & derivados , Organofosfonatos , Oxirredução , Titânio
5.
Anal Chim Acta ; 1159: 338418, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33867032

RESUMO

Favipiravir, a promising antiviral agent, is undergoing clinical trials for the potential treatment of the novel coronavirus disease 2019 (COVID-19). This is the first report for the electrochemical activity of favipiravir and its electroanalytical sensing. For this purpose, the effect of cationic surfactant, CTAB was demonstrated on the enhanced accumulation of favipiravir at the surface of cathodically pretreated boron-doped diamond (CPT-BDD) electrode. At first, the electrochemical properties of favipiravir were investigated in the surfactant-free solutions by the means of cyclic voltammetry. The compound presented a single oxidation step which is irreversible and adsorption controlled. A systematic study of various operational conditions, such as electrode pretreatment, pH of the supporting electrolyte, concentration of CTAB, accumulation variables, and instrumental parameters on the adsorptive stripping response, was examined using square-wave voltammetry. An oxidation signal at around +1.21 V in Britton-Robinson buffer at pH 8.0 containing 6 × 10-4 M CTAB allowed to the adsorptive stripping voltammetric determination of favipiravir (after 60 s accumulation step at open-circuit condition). The process could be used in the concentration range with two linear segments of 0.01-0.1 µg mL-1 (6.4 × 10-8-6.4 × 10-7 M) and 0.1-20.0 µg mL-1 (6.4 × 10-7-1.3 × 10-4 M). The limit of detection values were found to be 0.0028 µg mL-1 (1.8 × 10-8 M), and 0.023 µg mL-1 (1.5 × 10-7 M) for the first and second segments of calibration graph, respectively. The feasibility of developed methodology was tested to the analysis of the commercial tablet formulations and model human urine samples.


Assuntos
Amidas/química , Antivirais/química , Boro , Diamante , Eletrodos , Pirazinas/química , Tensoativos/química , Humanos , SARS-CoV-2/efeitos dos fármacos
6.
Water Sci Technol ; 83(8): 1907-1919, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33905361

RESUMO

Bisphenol A (BPA) is a known endocrine disrupter and was detected in surface waters. We investigated the mineralization of BPA by electrochemical oxidation. Six different types of electrodes, including the boron-doped diamond (BDD), platinum (Pt), and mixed metal oxide (MMO) electrodes; RuO2-IrO2, RuO2-TiO2, IrO2-Ta2O5, and Pt-IrO2, were compared as the anode material. Total organic carbon (TOC) was analyzed to monitor the mineralization efficiency of BPA. BDD achieved 100% BPA mineralization efficiency in 180 min and at a current density of 125 mA/cm2, whereas the TOC removal efficiency of Pt was 60.9% and the efficiency of MMO electrodes ranged between 48 and 54%. BDD exhibited much lower specific energy consumption, which corresponds to a lower energy cost (USD63.4 /kg TOC). The effect of operational parameters showed that the BDD anode was much more affected by the current density, initial BPA concentration, and electrolyte concentration than the other parameters such as the stirring speed and interelectrode distance.


Assuntos
Poluentes Químicos da Água , Compostos Benzidrílicos , Diamante , Eletrodos , Oxirredução , Fenóis , Poluentes Químicos da Água/análise
7.
Talanta ; 229: 122260, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33838771

RESUMO

7-Dehydrocholesterol is an essential biomarker of Smith-Lemli-Opitz syndrome, a congenital autosomal recessive disorder. This study shows for the first time that electrochemical oxidation of 7-dehydrocholesterol can be used for its voltammetric determination. Two classes of supporting electrolytes in acetonitrile and a mixture of acetonitrile-water were used: inorganic acids known to promote structural changes of steroids and indifferent electrolytes. Oxidation of 7-dehydrocholesterol at ca +0.8 V (vs. Ag/AgNO3 in acetonitrile) in 0.1 mol L-1 NaClO4 in acetonitrile is useful for its voltammetric detection using common bare electrode materials. Detection limits for 7-dehydrocholesterol lie in the low micromolar range for all the working electrodes, including boron-doped diamond (0.4 µmol L-1) and disposable thin-film platinum electrodes (0.5 µmol L-1), which are advantageous because of the low volumes of studied solutions. After Bligh-Dyer extraction, quantification of 7-dehydrocholesterol concentration (boron-doped diamond) or concentration range (thin-film platinum) is easily attainable in artificial serum. The mere knowledge of the concentration range provides clinically valuable information, as 7-dehydrocholesterol levels are employed for SLOS diagnosis as a binary criterion (elevated, tens to hundreds µmol L-1 in symptomatic/non-elevated, typically bellow 1 µmol L-1 in healthy individuals in plasma). Moreover, it is shown that 7-dehydrocholesterol (provitamin D3) and cholecalciferol (vitamin D3) can be oxidized in 0.1 mol L-1 HClO4 in acetonitrile. Under these conditions, their voltammetric response changes dramatically, and their oxidation potential difference transiently increases from 0.08 V to 0.25 V, which should facilitate their simultaneous voltammetric determination. This work constitutes a foundation for a reliable and straightforward method for Smith-Lemli-Opitz syndrome diagnosis and monitoring 7-dehydrocholesterol's biotransformation to cholecalciferol.


Assuntos
Desidrocolesteróis , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Síndrome de Smith-Lemli-Opitz , Desidrocolesteróis/análise , Diamante , Humanos , Síndrome de Smith-Lemli-Opitz/diagnóstico
8.
J Environ Manage ; 290: 112573, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33873022

RESUMO

Electrochemical degradation using boron-doped diamond (BDD) electrodes has been proven to be a promising technique for the treatment of water contaminated with per- and poly-fluoroalkyl substances (PFAS). Various studies have demonstrated that the extent of PFAS degradation is influenced by the composition of samples and electrochemical conditions. This study evaluated the significance of several factors, such as the current density, initial concentration of PFAS, concentration of electrolyte, treatment time, and their interactions on the degradation of PFAS. A 24 factorial design was applied to determine the effects of the investigated factors on the degradation of perfluorooctanoic acid (PFOA) and generation of fluoride in spiked water. The best-performing conditions were then applied to the degradation of PFAS in wastewater samples. The results revealed that current density and time were the most important factors for PFOA degradation. In contrast, a high initial concentration of electrolyte had no significant impact on the degradation of PFOA, whereas it decreased the generation of F-. The experimental design model indicated that the treatment of spiked water under a current density higher than 14 mA cm-2 for 3-4 h could degrade PFOA with an efficiency of up to 100% and generate an F- fraction of approximately 40-50%. The observed high PFOA degradation and a low concentration of PFAS degradation products indicated that the mineralization of PFOA was effective. Under the obtained best conditions, the degradation of PFOA in wastewater samples was 44-70%. The degradation efficiency for other PFAS in these samples was 65-80% for perfluorooctane sulfonic acid (PFOS) and 42-52% for 6-2 fluorotelomer sulfonate (6-2 FTSA). The presence of high total organic carbon (TOC) and chloride contents was found to be an important factor affecting the efficiency of PFAS electrochemical degradation in wastewater samples. The current study indicates that the tested method can effectively degrade PFAS in both water and wastewater and suggests that increasing the treatment time is needed to account for the presence of other oxidizable matrices.


Assuntos
Fluorcarbonetos , Poluentes Químicos da Água , Boro , Diamante , Eletrodos , Águas Residuárias , Poluentes Químicos da Água/análise
9.
J Environ Manage ; 290: 112548, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33878628

RESUMO

Large amounts of silicon cutting waste (SCW) are generated during Si wafers producing process. In this paper, SCW was mixed with Al powder to prepare Al-Si alloys by a one-step smelting process in corundum crucibles. The influences of smelting temperature (1000 °C, 1200 °C and 1500 °C) on the products of each zone (surface layer zone, loose granular zone and blocky products zone) were investigated. Al-Si alloys in the form of granular and blocky were prepared and the blocky Al-Si alloys mainly concentrated in the blocky products zone. The increase of smelting temperature can promote the aggregation of Al-Si alloy particles. The yields of Al-Si alloy blocks obtained at 1000 °C, 1200 °C and 1500 °C were 0%, 58% and 69%, respectively. The Si contents of Al-Si alloy blocks at 1200 °C and 1500 °C were 15.8 wt% and 17.1 wt% respectively. After compacting the raw materials, the yields of the blocky Al-Si alloys obtained at 1000 °C, 1200 °C and 1500 °C were increased to 65%, 72% and 79% and the corresponding Si contents of the blocky Al-Si alloys were increased to 16.0 wt%, 16.5 wt% and 17.3 wt% respectively. The reaction mechanism of the alloying process was also investigated.


Assuntos
Ligas , Silício , Óxido de Alumínio , Diamante , Temperatura
10.
Front Cell Infect Microbiol ; 11: 595323, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33732655

RESUMO

The gut microbiota of preterm infants is affected by perinatal factors and, in turn, may impact upon infant health. In this study, we collected fecal samples at Day-10 (D10) and 4-months corrected-age (4M) from 227 moderate-late preterm (MLPT) babies enrolled in a randomized controlled trial of nutritional management. A total of 320 samples underwent 16S amplicon sequencing, and shotgun metagenomic sequencing was performed on 94 samples from the 4M time point. The microbiome of babies whose families lived in lower socioeconomic status (SES) areas exhibited a significantly higher microbial alpha diversity at D10 (Wilcoxon test, p = 0.021), greater abundance of Bifidobacterium (linear model, q = 0.020) at D10 and Megasphaera (q = 0.031) at 4M. Hospital of birth explained 5.2% of the observed variance in 4M samples (PERMANOVA, p = 0.038), with Staphylococcus aureus more abundant in fecal samples from babies born in Middlemore hospital (linear model, q = 0.016). Maternal antibiotic (Wilcoxon test, p = 0.013) and probiotic (p = 0.04) usage within the four-week period before sample collection was associated with a reduction in the alpha diversity of D10 samples. Infant probiotic intake explained 2.1% (PERMANOVA, p = 0.021) of the variance in the D10 microbial profile with increased Lactobacillus (linear model, q = 1.1 × 10-10) levels. At 4M, the microbiome of infants who were breastmilk fed had reduced alpha diversity when compared to non-breastmilk fed infants (Wilcoxon test, p < 0.05). Although causality cannot be inferred within our study, we conclude that in MLPT babies, maternal socioeconomic factors, as well as the perinatal medical environment and nutrition impact on the development of the newborn microbiome.


Assuntos
Recém-Nascido Prematuro , Microbiota , Estudos de Coortes , Diamante , Fezes , Feminino , Humanos , Lactente , Recém-Nascido , Gravidez , RNA Ribossômico 16S
11.
Water Sci Technol ; 83(6): 1357-1368, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33767042

RESUMO

Conventional biological treatments used in most Indonesian landfill sites are mostly ineffective in treating stabilized landfill leachates to meet the standard regulation. Thus, a combination of biological and electrochemical process is offered to successfully treat leachates containing a high concentration of organic and nitrogenous compounds. In this study, a moving bed biofilm reactor (MBBR) was applied prior to electrochemical oxidation by using boron-doped diamond (BDD), Ti/IrO2, and Ti/Pt anodes with applied current of 350, 400 and 450 mA. The objectives were to investigate the effect of anode type and the applied current on the removal of organics as well as total nitrogen from the MBBR-treated leachate with electrochemical oxidation. The optimum removal of chemical oxygen demand (COD) observed on the Ti/Pt anode was 78% by applying 400 mA, with an estimated energy of 56.7 Wh g L-1. In the case of Ti/IrO2 and BDD anodes, the optimum removal of COD was 76 and 85% with an energy consumption of 58.9 and 36.9 Wh g L-1, respectively, both achieved at 350 mA. Although all anodes showed less-satisfactory performances for total nitrogen reduction, around 46-95% removal of nitrogenous compounds was achieved by MBBR, with their partial conversion to nitrates.


Assuntos
Diamante , Poluentes Químicos da Água , Biofilmes , Reatores Biológicos , Boro , Eletrodos , Indonésia , Oxirredução , Titânio , Poluentes Químicos da Água/análise
12.
J Vis Exp ; (168)2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33720136

RESUMO

Serial data collection is a relatively new technique for synchrotron users. A user manual for fixed target data collection at I24, Diamond Light Source is presented with detailed step-by-step instructions, figures, and videos for smooth data collection.


Assuntos
Coleta de Dados , Diamante/química , Cristalografia por Raios X , Análise de Dados , Luz , Síncrotrons , Interface Usuário-Computador
13.
J Mech Behav Biomed Mater ; 118: 104478, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33770586

RESUMO

Ag-doped Cr/DLC coatings were deposited on medical grade 316 LVM stainless steel using DC magnetron sputtering. Morphological study of the coating indicated the formation of island of Ag clusters owing to the inability of Ag to form carbides, which is also corroborated from the XRD analysis. The composite coating showcased elastic nature suggestive from the p-h curve obtained from the nanoindentation test. However, the coating possesses 33% ductility, which is an important virtue for stress relieving attributed to Ag in the carbon matrix. The coating registered improved adhesion due to Cr3C2 carbide formation in the interlayer. The composite coating was subjected to lubricated sliding in physiological fluid against carbon fiber reinforced PEEK (CFRPEEK) friction pair to realize a closer scenario to hip implant articulation. A lubricious film of Ag with scattered particles of PEEK was formed in the sliding interface resulting in a long run-in process during sliding. The composite coating suffered mild wear on the Ag-doped DLC top layer with few gullies of wear scar deep into the interlayer due to graphitization of carbon in the film. A statistically significant difference was observed in the hardness, H3/E2, elastic work, and plastic work; however, there was no statistically significant difference in H/E attribute between the unworn and worn surface. What is more, Raman spectra of the worn (ID/IG = 1.9 ± 0.2) and unworn surface (ID/IG = 2.1 ± 0.1) were indicative of no significant loss in the structural integrity of the composite coating.


Assuntos
Ligas , Prata , Fibra de Carbono , Diamante , Cetonas , Teste de Materiais , Polietilenoglicóis
14.
Chemosphere ; 273: 129696, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33524759

RESUMO

The electro-oxidation of tetracycline (TeC) in methanol medium containing chloride or sulfate ions was evaluated using a DSA®-Cl2 in a flow reactor and compared with BDD. The results show that after 30 min of electrolysis no TeC is detected by liquid chromatography when chloride is used as supporting electrolyte. On the other hand, after 90 min of electrolysis using a BDD anode only 61% of TeC was removed from solutions with chloride, but in the presence of sulfate the removal reaches 94%. This evidences that the oxidizing species generated during electrochemical oxidation control the process and the mechanism of degradation of the TeC. Besides that, it was possible to infer that only a small amount of methanol might convert to formaldehyde or formic acid, although they were not detected according to the nil changes in the FTIR spectra or in the HPLC chromatograms recorded.


Assuntos
Metanol , Poluentes Químicos da Água , Diamante , Eletrodos , Eletrólise , Oxirredução , Sulfatos , Poluentes Químicos da Água/análise
15.
J Chromatogr A ; 1640: 461936, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33548824

RESUMO

Since the advent of diamond-based adsorbents in the late 1960s, the interest in their use for solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) has steadily increased. This is primarily due to their unique properties, such as extreme chemical and thermal stability, high mechanical strength and biocompatibility, and complex mixed-mode retention mechanisms. Currently, the most commonly used synthetic diamonds in SPE and HPLC are detonation nanodiamonds (DND), high-pressure high-temperature (HPHT) diamonds, and chemical vapour deposition (CVD) diamonds. These diamonds have been either used as individual particles (in both modified and unmodified forms), or for surface modification, or entrapped within composites and core-shell particles to develop new diamond-based adsorbents. These diamond-based adsorbents have been used for a variety of applications, including streamlined proteome analysis; extraction of anions, cations, actinides, uranium, lanthanides, alkaline earth metals, transition metals, and post-transition metals; and development of reversed-phase, normal phase, hydrophilic interaction, ion chromatography, and mixed-mode liquid chromatography columns, to name but a few. These varied applications of different types of diamonds are typically governed by their specific properties. This review discusses the various surface and bulk properties of DND, HPHT diamonds, and CVD diamonds that facilitate or limit their use in different SPE and HPLC based applications.


Assuntos
Diamante/química , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Interações Hidrofóbicas e Hidrofílicas , Nanodiamantes/ultraestrutura , Temperatura
16.
Mater Sci Eng C Mater Biol Appl ; 121: 111792, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33579442

RESUMO

A unique composite nanodiamond-based porous material with a hierarchically-organized submicron-nano-structure was constructed for potential bone tissue engineering. This material consisted of submicron fibers prepared by electrospinning of silicon oxide (SiOx), which were oxygen-terminated (O-SiOx) and were hermetically coated with nanocrystalline diamond (NCD) films. The NCD films were then terminated with hydrogen (H-NCD) or oxygen (O-NCD). The materials were tested as substrates for the adhesion, growth and osteogenic differentiation of human osteoblast-like Saos-2 cells. The number and the spreading area of the initially adhered cells, their growth rate during 7 days after seeding and the activity of alkaline phosphatase (ALP) were significantly higher on the NCD-coated samples than on the uncoated O-SiOx samples. In addition, the concentration of type I collagen was significantly higher in the cells on the O-NCD-coated samples than on the bare O-SiOx samples. The observed differences could be attributed to the tunable wettability of NCD and to the more appropriate surface morphology of the NCD-coated samples in contrast to the less stable, rapidly eroding bare SiOx surface. The H-NCD coatings and the O-NCD coatings both promoted similar initial adhesion of Saos-2 cells, but the subsequent cell proliferation activity was higher on the O-NCD-coated samples. The concentration of beta-actin, vinculin, type I collagen and alkaline phosphatase (ALP), the ALP activity, and also the calcium deposition tended to be higher in the cells on the O-NCD-coated samples than on the H-NCD-coated samples, although these differences did not reach statistical significance. The improved cell performance on the O-NCD-coated samples could be attributed to higher wettability of these samples (water drop contact angle less than 10°), while the H-NCD-coated samples were hydrophobic (contact angle >70°). NCD-coated porous SiOx meshes can therefore be considered as appropriate scaffolds for bone tissue engineering, particularly those with an O-terminated NCD coating.


Assuntos
Diamante , Osteogênese , Adesão Celular , Diferenciação Celular , Proliferação de Células , Materiais Revestidos Biocompatíveis/farmacologia , Humanos , Osteoblastos
17.
Dent Mater J ; 40(3): 727-735, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-33563847

RESUMO

This study aimed to compare the change of surface roughness (Ra) and gloss units (GU) of five dental composites (Filtek Z250, Filtek Z350XT, Metafil CX, Ceram X one, and Venus Diamond) polished with three systems (Sof-Lex XT, Enhance/Pogo, and Sof-Lex Diamond) before/after simulated brushings and to determine the amount of time required to achieve maximum gloss. Ninety rectangular specimens (n=18 per composite) were prepared. Six specimens of each composite were assigned to one of the polishing systems. The Ra and GU of each specimen were measured after each polishing step. Five polished specimens per composite were brushed with a toothbrush machine, and the Ra and GU values were determined. Filtek Z350XT exhibited the most stable and lowest Ra during the brushing cycles regardless of polishing system. When using the Sof-Lex Diamond and Enhance/Pogo systems, the highest gloss and the smoothest surfaces were achieved after polishing and brushing.


Assuntos
Resinas Compostas , Polimento Dentário , Diamante , Teste de Materiais , Propriedades de Superfície , Escovação Dentária
18.
Chemosphere ; 270: 129344, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33395582

RESUMO

The treatment of hospital wastewater is very complex, so treating polluted human urine is a significant challenge. Here, we tested a novel MMO-Ti/RuO2IrO2 electrode to reduce the ecotoxicity risk of hospital urines contaminated with antibiotics. This electrode was used as the anode in electro-Fenton (EF) and photoelectro-Fenton (PhEF) processes. The results were compared with those obtained using the boron-doped diamond (BDD) anode, as well as those obtained by a conventional Fenton oxidation. In order to analyze the performance of the processes, the treatments were evaluated on the subject of Penicilin G (PenG) removal, toxicity (using a standardized method with Vibrio Fisheri), and antibiotic activity (Enterococcus faecalis as the target bacterium). The results reveal that PenG degrades in the following order: Fenton < EF < PhEF. The best results are found for the MMO-PhEF, which completely removed PenG, decreased 96% of toxicity, and completely removed antibiotic activity. Besides, for comparison, tests were performed with BDD, and results point out the higher convenience of the new electrode in terms of acceptable use of energy because the effluents generated can be further degraded in an urban wastewater treatment plant. Because of that, MMO-RuO2-IrO2 emerges as a promising cost-effective material for the pre-treatment of hospital urine effluents.


Assuntos
Titânio , Poluentes Químicos da Água , Antibacterianos/toxicidade , Diamante , Eletrodos , Humanos , Peróxido de Hidrogênio , Oxirredução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
19.
Head Face Med ; 17(1): 2, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33499906

RESUMO

Oro-Pharyngeal Dysphagia - or simply dysphagia - is the difficulty (persistent) in swallowing/passing food and/or liquid from the mouth to the pharynx into the esophagus and finally the stomach; a deglutition disorder (a symptom, by definition, often due to neuro-degenerative/-muscular, drug-induced or localized structural pathologies such as head and neck tumors, lesions and associated surgical and/or radiation injuries) linked to severe consequences on Quality of Life (QoL), including malnutrition, dehydration, and even sudden death. Likewise, Temporo-Mandibular Jaw and Joint disorder(s) - or simply TMD - is a multifactorial etiological condition, regularly encountered in the dental office. Whether due to malocclusion, bruxism, stress and/or trauma, TMD destabilizes the whole cranio-mandibular system structurally and functionally, via affecting mastication, teeth, supporting structures, comfort and aesthetics, and thus, QoL, again. While several treatment regimens do exist for such conditions, some of which have been standardized for use over the years, most continue to lack proper evidence-based literature support. Hence, (1) caution is to be exercised; and (2) the need for alternative therapeutic strategies is amplified, subsequently, the door for innovation is wide open. Indeed, neuromuscular electrical stimulation or "NMES", is perhaps a fine example. Herein, we present the interested oro-dental health care provider with an up-dated revision of this therapeutic modality, its potential benefits, risks and concerns, to best handle the dysphagic patient: an intra-disciplinary approach or strategy bridging contemporary dentistry with speech and language therapy; a rather obscure and un-discovered yet critical allied health profession. A pre-clinical and clinical prospectus on employing inventive NMES-based regimens and devices to manage TMD is also highlighted.


Assuntos
Transtornos de Deglutição , Qualidade de Vida , Deglutição , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/terapia , Diamante , Estética Dentária , Humanos , Boca
20.
Water Res ; 190: 116783, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33387957

RESUMO

The solar driven advanced oxidation process (AOP) has the potential to be developed as a passive stormwater post-treatment method. Despite its widespread studies in wastewater treatment, the applicability of the process for micropollutant removal in stormwater (which has very different chemical properties from wastewater) is still unknown. This paper investigated the feasibility of three different AOP processes for the degradation of two herbicides (diuron and atrazine) in pre-treated stormwater: (i) photoelectrochemical oxidation (PECO), (ii) electrochemical oxidation (ECO), and (iii) photocatalytic oxidation (PCO). The durability of different anode materials, the effects of catalyst loading, and solar photo- and thermal impacts under different applied voltages were studied. Boron-doped diamond (BDD) was found to be the most durable anode material compared to carbon fiber and titanium foil for long-term operation. Due to the very low electroconductivity of stormwater, a high voltage was required, causing severe oxidation of the carbon fiber material. PECO achieved the best degradation results compared to ECO and PCO, with over 90% degradation of both herbicides in 2 h under 5 V, following a first-order decay process (with a half-life value of 0.40 h for diuron and 0.58 h for atrazine). The voltage increase had a positive impact on the oxidation processes, with 5 V found to be the optimal applied voltage, while catalyst loading had a negligible effect. Interestingly, the solar thermal effect plays a dominant role in enhancing the performance of the PECO process, which indicates the potential of integrating a photovoltaic chamber with a PECO system to harness both the light and heat of solar energy for stormwater treatment.


Assuntos
Herbicidas , Poluentes Químicos da Água , Purificação da Água , Diamante , Eletrodos , Estudos de Viabilidade , Herbicidas/análise , Oxirredução , Chuva , Poluentes Químicos da Água/análise , Abastecimento de Água
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