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1.
Chemosphere ; 262: 127836, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32805657

RESUMO

Polyacrylonitrile fiber was successfully modified with triazine-based dendrimer via grafting method as a promising adsorbent for removal of mercury species from aqueous media. The prepared adsorbent was characterized by elemental analysis, scanning electron microscope, Fourier transform infrared spectroscopy, porous structure analysis and X-ray photoelectron spectroscopy, providing the evidence of successful fabrication. The adsorption conditions were found via varying pH, dosage, coexisting substances, contact time, temperature and concentration. Adsorption performance, described better by the pseudo-second-order kinetics with intraparticle diffusion as rate controlling step and Langmuir isotherm model, indicated a chemisorption process with the maximum Langmuir adsorption amount of 227.64 mg g-1 for mercury ions. Thermodynamically, adsorption of mercury ions was spontaneous and endothermic. Desorption and regeneration experiments demonstrated that it could be reused in five successive adsorption cycles without significant loss of its original performance. Experimental data and density functional theory calculation disclosed the coordination geometries and chelating mechanism between the adsorbent and mercury ions. The proposed study would provide a new prospect for the purification of mercury in aqueous system by functionalizing commercial polyacrylonitrile fiber with dendrimers.


Assuntos
Resinas Acrílicas/química , Dendrímeros/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Difusão , Concentração de Íons de Hidrogênio , Íons/análise , Cinética , Mercúrio/análise , Temperatura , Termodinâmica , Águas Residuárias/química , Água/química , Poluentes Químicos da Água/análise
2.
Food Chem ; 335: 127631, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32736157

RESUMO

In this work, sodium 4-styrenesulfonate functionalized polyacrylonitrile nanofibers mat (SS/PAN NFM) was firstly prepared and applied as 96-well plate solid-phase extraction adsorbent for quantitative determination of seven ß-agonists residues in pork samples. The functional modification endowed the SS/PAN NFM with superior adsorption performance for target ß-agonists. The adsorption process is spontaneous (ΔG < 0), the initial adsorption rate can reach 6.03-9.09 mg/g/min and the maximum adsorption capacity is calculated to be 48.3 mg/g at 298 K. Moreover, SS/PAN NFM can be reused for 12 times without degradation in adsorption capability. Combined with UPLC-MS/MS, the limits of detection can reach 0.006-0.24 µg/kg, the recoveries ranged from 87.2% to 111% and the relative standard deviations of intra-day and inter-day precisions were in the scope of 1.75%-11.6% and 5.08%-13.5%, respectively. The obtained results fully demonstrated the practicability of this method in preventing the hazard of ß-agonists residues.


Assuntos
Agonistas Adrenérgicos beta/análise , Agonistas Adrenérgicos beta/isolamento & purificação , Análise de Alimentos/métodos , Nanofibras/química , Poliestirenos/química , Carne Vermelha/análise , Extração em Fase Sólida/métodos , Resinas Acrílicas/química , Agonistas Adrenérgicos beta/química , Adsorção , Animais , Contaminação de Alimentos/análise , Limite de Detecção , Suínos
3.
Food Chem ; 337: 127763, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32791431

RESUMO

In this work, water-resistant poly (vinyl alcohol) (PVA)/poly (acrylic acid) (PAA) electrospun fibers encapsulating tangeretin (Tan) were fabricated by emulsion-electrospinning. To optimize the electrospinning condition, the size and morphology of electrospun fibers were characterized by dynamic light scattering (DLS), optical light microscope, fluorescence microscopy, and scanning electron microscopy (SEM), respectively. The optimized initial concentration of PVA/PAA was 10% (w/w) with a mass ratio of 3:7. The time and temperature of optimized thermal crosslinking treatment were 2 h and 145 °C, respectively. The results of XRD and SEM showed that the Tan was successfully incorporated into smooth PVA/PAA electrospun fibers and those fibers possessed nano-diameter size and high porosity. The encapsulation of Tan had no significant impact on the antioxidant activity of PVA/PAA/Tan crosslinking electrospun fibers. The in vitro release test showed the PVA/PAA/Tan crosslinking electrospun fibers achieved durable release profiles and lower burst release rates than that from the pure Tan emulsion. Based on these results, it is concluded that PVA/PAA/Tan crosslinking electrospun fibers prepared by emulsion-electrospinning serve as a promising technique in the fields of water-insoluble drug delivery and slow-release.


Assuntos
Resinas Acrílicas/química , Antioxidantes/química , Portadores de Fármacos/química , Eletricidade , Flavonas/química , Álcool de Polivinil/química , Liberação Controlada de Fármacos , Emulsões
4.
Chemosphere ; 262: 128072, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182132

RESUMO

A new synthesis method was developed to prepare an aluminum-based metal organic framework (MIL-96) with a larger particle size and different crystal habits. A low cost and water-soluble polymer, hydrolyzed polyacrylamide (HPAM), was added in varying quantities into the synthesis reaction to achieve >200% particle size enlargement with controlled crystal morphology. The modified adsorbent, MIL-96-RHPAM2, was systematically characterized by SEM, XRD, FTIR, BET and TGA-MS. Using activated carbon (AC) as a reference adsorbent, the effectiveness of MIL-96-RHPAM2 for perfluorooctanoic acid (PFOA) removal from water was examined. The study confirms stable morphology of hydrated MIL-96-RHPAM2 particles as well as a superior PFOA adsorption capacity (340 mg/g) despite its lower surface area, relative to standard MIL-96. MIL-96-RHPAM2 suffers from slow adsorption kinetics as the modification significantly blocks pore access. The strong adsorption of PFOA by MIL-96-RHPAM2 was associated with the formation of electrostatic bonds between the anionic carboxylate of PFOA and the amine functionality present in the HPAM backbone. Thus, the strongly held PFOA molecules in the pores of MIL-96-RHPAM2 were not easily desorbed even after eluted with a high ionic strength solvent (500 mM NaCl). Nevertheless, this simple HPAM addition strategy can still chart promising pathways to impart judicious control over adsorbent particle size and crystal shapes while the introduction of amine functionality onto the surface chemistry is simultaneously useful for enhanced PFOA removal from contaminated aqueous systems.


Assuntos
Alumínio/química , Caprilatos/análise , Fluorcarbonetos/análise , Dietilamida do Ácido Lisérgico/análogos & derivados , Estruturas Metalorgânicas/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Resinas Acrílicas/química , Adsorção , Carvão Vegetal/química , Dietilamida do Ácido Lisérgico/química , Tamanho da Partícula , Solubilidade , Propriedades de Superfície
5.
Oral Health Prev Dent ; 18(1): 999-1010, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33215491

RESUMO

PURPOSE: This study investigated the effect of long-term daily chemical disinfection on the topographic and Candida albicans biofilm formation on a denture base resin and a reline acrylic resin. MATERIAL AND METHODS: Circular samples (14 × 1.2 mm) were fabricated from a denture base (Vipi Wave) and reline acrylic resins (Tokuyama Rebase Fast II). Samples were kept in 50 ml of distilled water (48 h at 37°C). Subsequently, the samples were immersed in five different solutions: 0.5% sodium hypochlorite; 3.8% sodium perborate; 2% chlorhexidine gluconate; apple vinegar containing 4% maleic acid; and distilled water (control group). The specimen was immersed in the solutions for 8 h daily and transferred to distilled water at 37°C for more 16 h. The surface topographic and Candida albicans (ATCC 90028) biofilm formation were evaluated at baseline (before chemical disinfection) and after 1, 3 and 6 months of immersion. The surface topographic was evaluated by arithmetical roughness average (Ra) and scanning electron microscope (SEM), while the biofilm formation was evaluated by colony-forming units (CFU/ml) method and Alamar Blue assay (cell metabolism). The results were evaluated by three-way analysis of variance (ANOVAs) and post-hoc tests (α = 0.05). RESULTS: The results showed statistically significant effects from the type of acrylic resin (p = 0.029) and time (p <0.001) on the roughness of the specimen. In general, the reline resin had higher roughness than the denture base resin. In addition, the roughness of the samples after 1, 3 and 6 months of immersion in the cleaning solutions was higher than at baseline. In relation to the microbiological assays, there were no statistically significant differences (p >0.055) in the CFU/ml values of the biofilms among the different resins, periods of time and cleaning solutions. Considering the metabolism of the cells within the biofilms, the results showed that, at baseline, it was statistically significantly higher (p <0.05) than after 1, 3 and 6 months of storage. The SEM images showed that all disinfectant solutions provided surface changes of both acrylic resins (base and reline) after 1, 3 and 6 months of immersion. CONCLUSIONS: The roughness of both acrylic resins was affected by the disinfection in all cleaning agents, increasing over time, and this effect was more evident in the reline acrylic resin group. This surface change was also observed in the SEM images. While the number of cells within the biofilms was not affected by immersion in the cleaning agents, their metabolism was lower after 1, 3 and 6 months of immersion.


Assuntos
Candida albicans , Desinfecção , Resinas Acrílicas , Biofilmes , Bases de Dentadura , Higienizadores de Dentadura/farmacologia , Teste de Materiais , Propriedades de Superfície
6.
Braz Dent J ; 31(5): 511-515, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33146335

RESUMO

This study aimed to assess the physicochemical properties of a repair material in the Brazilian market, BioMTA, in comparison to other two materials currently in use (Biodentine and MTA Angelus). The initial setting time was evaluated using Gillmore needle. The pH was measured with a pH-meter after 24 h, 3, 7, 14 and 21 days. The radiopacity was determined using the equivalence in millimeters of aluminum (mm Al) from digitized occlusal radiographs. Solubility was determined after immersion in water for 7 days. The data were analyzed by one-way ANOVA and Tukey tests (a=0.05). The BioMTA initial setting time (5.2 min) was lower than the other materials (p<0.05). All materials showed an alkaline pH at 21 days. At 24 h, BioMTA was the most alkaline material (p<0.05); and at 3, 7, 14 and 21 days there was no difference between BioMTA and Biodentine (p>0.05), both being more alkaline than MTA Angelus (p<0.05). The radiopacity of BioMTA (4.2 mm Al) was significantly higher compared to Biodentine (p<0.05) and lower than MTA Angelus (p<0.05). The solubility of the materials was -4.2%, -1.6% and 4.1% for BioMTA, MTA Angelus and Biodentine, respectively, with a significant difference between them (p<0.05). Therefore, it can be concluded that BioMTA displayed a shorter setting time, an alkaline pH, a higher radiopacity, and a gain in mass.


Assuntos
Materiais Restauradores do Canal Radicular , Silicatos , Resinas Acrílicas , Compostos de Alumínio , Brasil , Compostos de Cálcio , Combinação de Medicamentos , Teste de Materiais , Óxidos , Solubilidade , Água
7.
J Adhes Dent ; 22(5): 465-474, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33073778

RESUMO

PURPOSE: This sub-analysis of our multicenter trial was to assess the long-term periodontal health (PH) of teeth, esthetically reshaped by means of direct composite buildups. MATERIALS AND METHODS: 198 patients who received 667 direct composite buildups on 585 treated teeth (TT) between 01/2001 and 12/2013 were included. PH was assessed for each TT and for an untreated control tooth (CT) by recording the pocket probing depths (PPD), clinical attachment level (CAL), sulcus bleeding index (SBI), and Turesky's modification of the Quigley Hein plaque index (PI). Statistical analysis was performed using the two-sample Student's t-test and Mann-Whitney U-test. Regression models were performed to check for associations between PH and patients' age, gender, age of the buildups, enlargement range, jaw, and tooth type. The level of significance was set at α = 0.05. RESULTS: PI scores were significantly (p < 0.001) higher in TT (1.60 ± 0.81) than in CT (1.41 ± 0.81). Differences between TT and CT regarding PPD (TT: 2.14 ± 0.56/CT: 2.18 ± 0.56), CAL (TT: 2.34 ± 1.05/CT: 2.33 ± 0.92), and SBI (TT: 0.41 ± 0.60/CT: 0.41 ± 0.65) were not statistically significant (p > 0.05). The enlargement range of the TT and the tooth type were not associated with PH. Male patients had significantly higher PPDs, CAL, and SBI values than did female patients. CAL and SBI values increased over time for both the TT and CT. CAL, SBI, and PI values were significantly higher in the mandible and the PPD values in the maxilla. CONCLUSION: Direct composite buildups made for reshaping, change of color or position of teeth did not impair PH in the long term.


Assuntos
Resinas Acrílicas , Resinas Compostas , Dentição , Poliuretanos , Cor , Feminino , Humanos , Masculino
8.
Indian J Dent Res ; 31(4): 589-592, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33107462

RESUMO

Aim: Nano-sized metal particles exhibit special biological, chemical, and physical properties. The aim of this study was to evaluate the effect of incorporating silver nanoparticles into a resin-modified glass ionomer (GI) on its antimicrobial property. Materials and Methods: Antibacterial action of GI samples containing 0, 40, 80 ppm silver nanoparticles against standard strains of Streptococcus sanguinis and Streptococcus mutans were assessed by agar diffusion and direct contact tests. Data were analyzed using analysis of variance and Duncan test (P < 0.05). Results: Agar diffusion test showed no bacterial inhibition zone, but direct contact test exhibited significant antimicrobial activity against S. sanguinis and S. mutans in resin containing 80 ppm of nanosilver. Conclusion: Incorporation of a certain amount of silver nanoparticles into GI can increase its antimicrobial activity compared to the original material.


Assuntos
Nanopartículas Metálicas , Streptococcus mutans , Resinas Acrílicas , Antibacterianos/farmacologia , Dióxido de Silício , Prata/farmacologia
9.
Water Sci Technol ; 82(7): 1350-1369, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33079715

RESUMO

A hydrophobically associating cationic polyacrylamide (HACPAM) was prepared by using a micellar polymerization method with V-50 (azobisisobutyramidine hydrochloride) as the initiator and acrylamide, acryloyloxyethyl trimethylammonium chloride and butyl methacrylate as substrates under ultraviolet light irradiation. Structural analysis using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance and X-ray photoelectron spectroscopy analyses showed that the substrates were successfully polymerized. HACPAM was used to condition sludge to improve its dewatering performance, and the results showed that as the amount of HACPAM increases, the sludge dewatering performance is significantly improved, and 3.532 kg/t dry solids of HACPAM is regarded as the optimal amount. Compared with the commercially available cationic polyacrylamide (CPAM), HACPAM has a stronger hydrophobic group association effect, with better promotion of the conversion of bound water in sludge flocs into free water, thereby improving the sewage dewatering performance. The 3D spatial structure of dewatered sludge cakes analyzed by computed tomography technology showed that the number of pores of the dewatered sludge cake treated by HACPAM 3 was smaller than that of the cake treated by CPAM, with a reduction in the porosity of 68.8%, resulting in a better hydrophobic effect. In addition, the mechanism of HACPAM improving the dewatering performance is discussed.


Assuntos
Resinas Acrílicas , Esgotos , Cátions , Polimerização
10.
Indian J Ophthalmol ; 68(11): 2486-2489, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33120649

RESUMO

Since the emergence of COVID pandemic, health workers have been facing major challenges every day. Ophthalmology practice has encountered countless modifications in the practice pattern not to jeopardize patient care and at the same time maintain all safety measures to reduce transmission. One such modification we made was the Safe Slit-Lamp Shield (SSS) which has been found to be extremely protective in differentiation to other available shield. Although SSS has a larger surface area when compared to already available shields, it won't compromise the comfort of the clinician at the same time gives satisfactory protection.


Assuntos
Betacoronavirus , Infecções por Coronavirus/transmissão , Segurança de Equipamentos , Ergonomia , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Pneumonia Viral/transmissão , Equipamentos de Proteção , Microscopia com Lâmpada de Fenda/instrumentação , Resinas Acrílicas , Aerossóis , Desenho de Equipamento , Humanos , Pandemias , Lâmpada de Fenda
11.
Bioresour Technol ; 318: 124053, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32942092

RESUMO

Economical removal of fermentation inhibitors from lignocellulosic hydrolysate plays a considerable role in bioconversion of lignocellulose biomass. In this work, the textural properties of polyacrylamide/polystyrene interpenetrating polymer networks (PAM/PS IPNs) on adsorption of fermentation inhibitors from sugarcane bagasse hydrolysate (SCBH) were investigated for the first time. The results showed that, the specific surface area, pore diameter and surface polarity had important influence on its adsorption performance towards sugars, organic acids, furans and acid-soluble lignin. The PAM/PS IPNs under the optimal copolymerization situation achieved the high selectivity coefficients of 4.07, 14.9, 21.2 and 25.8 with respective to levulinic acid, furfural, hydroxymethylfurfural (HMF) and acid-soluble lignin, and had a low total sugar loss of 2.09%. Overall, this research puts forward a design and synthetic strategy for adsorbent to remove fermentation inhibitors from lignocellulosic hydrolysate.


Assuntos
Saccharum , Resinas Acrílicas , Adsorção , Celulose , Fermentação , Hidrólise , Lignina/metabolismo , Polímeros , Poliestirenos , Saccharum/metabolismo
12.
Trends Pharmacol Sci ; 41(10): 681-684, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32891428

RESUMO

Fast-acting insulins are central to the regulation of prandial glucose in diabetic patients. Current fast-acting insulins require 20-30 min for the onset and longer for the peak blood concentrations. The recent work by Mann et al. used high-throughput synthesis and screening of polyacrylamide-based excipients to yield a formulation with pharmacokinetics that is faster than the currently available fast-acting insulins.


Assuntos
Excipientes , Insulina , Resinas Acrílicas , Humanos , Hipoglicemiantes
13.
Medicine (Baltimore) ; 99(33): e21516, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32871998

RESUMO

INTRODUCTION: Breast filler injections are less commonly used due to their associated complications, such as pain and foreign body reactions. Yet, these fillers are often administered illegally, resulting in aesthetic or life-threatening complications. These are treated by removing the foreign material, and the breasts are reconstructed using silicone implants or autologous tissue/fat injection. PATIENT CONCERNS: Case 1. A 45-year-old woman with polyacrylamide gel injections in both breasts visited our clinic for breast pain and tenderness. Grade I ptosis was observed in each breast, without skin necrosis and discoloration. Case 2. A 51-year-old woman, with unknown breast filler injections, visited our clinic for painful masses. Intraoperatively, massive amounts of foreign material had severely infiltrated the nearby tissues; thus, an immediate breast reconstruction could not be performed. Three months later, severe deformities including shrinkage and irregular breast skin surfaces were observed. DIAGNOSIS: Case 1. Multiple cystic lesions, fluid collection in the retromammary spaces, and diffuse infiltration were observed on mammography, computed tomography, and ultrasonography. Case 2. Multiple cystic lesions, calcified areas, and diffuse infiltrations in the axillae and retromammary spaces were observed on mammography, computed tomography, and ultrasonography. INTERVENTIONS: Case 1. The foreign material was removed and the breasts were reconstructed using silicone implants into subpectoral pocket with acellular dermal matrices (Alloderm, Lipocell Corporation). Case 2. A delayed reconstruction was undertaken using silicone implants covered by latissimus dorsi muscle flaps, 3 months after the foreign material removal. OUTCOMES: Case 1. The foreign material was removed and there were no complications such as foreign body reaction, capsular contracture. Ptosis was corrected and both breasts were symmetric with proper projection. Case 2. Residual foreign material was removed and there were no complications such capsular contracture, implant malposition. CONCLUSION: Massive injections of foreign materials into the breast can cause severe infiltration and associated foreign body reactions. By a near-complete removal of the foreign materials and breast reconstruction using silicone implants, we achieved satisfactory results, without complications such as wound disruption, capsular contracture, and implant malposition.


Assuntos
Resinas Acrílicas/efeitos adversos , Preenchedores Dérmicos/efeitos adversos , Reação a Corpo Estranho/cirurgia , Mamoplastia/métodos , Mastodinia/cirurgia , Feminino , Reação a Corpo Estranho/induzido quimicamente , Humanos , Mastodinia/induzido quimicamente , Pessoa de Meia-Idade
14.
Int J Prosthodont ; 33(5): 536-545, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956435

RESUMO

PURPOSE: To evaluate the shear bond strength (SBS) and color stability (ΔE) of four ceramic veneers (VITA VM 9; VITA VM 13; VITA VMK 95; and IPS e.max Ceram) following repair with three different self-adhesive composite resins (Fusio Liquid Dentin; Constic; and Vertise Flow) and BISCO Intraoral Repair Kit + Filtek Supreme (BC + FS). MATERIALS AND METHODS: A total of 96 specimens were prepared per ceramic material, and each ceramic group was divided into subgroups according to testing method (32 specimens for color stability analysis and 64 specimens for SBS testing). ΔE and SBS (SBS1 = non-aged, SBS2 = thermally aged) values of the repaired specimens were calculated. One specimen from each of the thermally aged groups was investigated under scanning electron microscopy (SEM). Two-way ANOVA was used to analyze the mean ΔE, SBS1, and SBS2 values. The differences between SBS1 and SBS2 values were analyzed using independent-samples t test. RESULTS: The lowest ΔE values were calculated for Constic (P ≤ .05). The SBS2 values among all groups were lower than the SBS1 values (P ≤ .05). The lowest SBS2 values were observed for Vertise Flow (2.3 ± 1.47 MPa) (P ≤ .05) and were below the acceptable limit of 5 MPa. CONCLUSION: All of the investigated repair materials in combination with the ceramic veneers exhibited ΔE values that were higher than the clinically acceptable limits. Thermal aging negatively affected the SBS values in all groups (P ≤ .05). All tested self-adhesive composite resins, with the exception of Vertise Flow, could be used instead of a repair kit with flowable composite resin, especially in noncooperative patients, for the purpose of repairing chipping fractures for VITA VM 9, VITA VM 13, and VITA VMK 95 (P > .05).


Assuntos
Colagem Dentária , Cimentos Dentários , Resinas Acrílicas , Cerâmica , Cor , Resinas Compostas , Porcelana Dentária , Humanos , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície
15.
Braz Oral Res ; 34: e110, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32876123

RESUMO

Acrylic resin has been used in the manufacture of prostheses, however, in the oral cavity, this material starts to retain microorganisms capable of causing gingival inflammation due its porosities. The aim of this study was to evaluate the influence of the use of silicon dioxide as a coating layer applied onto acrylic resin, on the adhesion of Candida albicans (Ca). After the incubation period in Sabouraud Dextrose Broth, a total of 1 ml of the Ca suspension was added to plate wells, each well containing a specimen of acrylic resin. The adhesion ability of Ca on acrylic resin was determined by counting colonies. Three groups (n = 6) of acrylic resin were assessed: with polishing (RP); without polishing (RW); with polishing and coating layer of silicon dioxide (RPC). Ca deposited on the surface of the acrylic resin was also observed using Scanning Electron Microscopy (SEM). Statistical assessment by Kruskal-Wallis and Student-Newman-Keuls Method were done (α = 2%). There was significant difference among the groups. The RPC group showed the lowest growth, with an average of 5.59 Log CFU/cm 2 ; there was a statistically significant difference in relation to group RW, which presented a growth of 6.07 Log CFU/cm 2 and to group RP with 5.91 Log CFU/cm 2 (p < 000.1). SEM images demonstrated that in the RP and RPC group, the surface of the resin had greater regularity, and smaller number of microorganisms. The application of silicon dioxide coating on acrylic resin appears to be a promising alternative, and its use can help in reducing the adhesion of Ca in prostheses.


Assuntos
Candida albicans , Resinas Acrílicas , Bases de Dentadura , Dióxido de Silício , Propriedades de Superfície
16.
Oral Health Prev Dent ; 18(1): 747-756, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32895658

RESUMO

PURPOSE: This in vitro study evaluated the effectiveness of polyacrylic acid as an acid etchant similar to phosphoric acid and its effect on the microtensile bond strength of self-adhesive resin cement to enamel. MATERIALS AND METHODS: Ninety Te-Econom Plus resin blocks (11 x 4 mm) were cemented onto bovine enamel and distributed into 10 groups according to the surface treatments (no surface treatment; etching with 37% phosphoric acid; etching with 20% polyacrylic acid; etching with 37% phosphoric acid + dental adhesive, and etching with 20% polyacrylic acid + dental adhesive) and the self-adhesive resin cements used (RelyX U200 and MaxCem Elite) (n = 9). After bonding, the specimens were sectioned into sticks, subjected to thermocycling (5760 cycles, 5°C and 55°C) and microtensile bond strength testing (n = 6). Images of representative specimens were obtained using a scanning electron microscope. Enamel penetration evaluation of different surface treatments was analysed by confocal laser scanning microscopy (n = 3). Data on bond strength were subjected to 2-way ANOVA and Tukey's least significant difference test (α = 0.05). RESULTS: Both 37% phosphoric acid and 20% polyacrylic acid yielded the same microtensile bond strength between self-adhesive resin cement and enamel, independent of the application of dental adhesives (p > 0.05). MaxCem Elite showed higher bond strength values than RelyX U200 just for the 20% polyacrylic acid group (p = 0.001). CONCLUSION: Acid pre-conditioning of dental enamel may influence the bond strength of self-adhesive resin cement to enamel, and 20% polyacrylic acid showed efficacy similar to that of 37% phosphoric acid.


Assuntos
Colagem Dentária , Cimentos de Resina , Condicionamento Ácido do Dente , Resinas Acrílicas , Animais , Bovinos , Resinas Compostas , Cimentos Dentários , Esmalte Dentário , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Resistência à Tração
17.
J Vasc Interv Radiol ; 31(10): 1612-1618.e1, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32826152

RESUMO

PURPOSE: To evaluate the utility of visualizing preprocedural MR images in 3-dimensional (3D) space using augmented reality (AR) before transarterial embolization of hepatocellular carcinoma (HCC) in a preclinical model. MATERIALS AND METHODS: A total of 28 rats with diethylnitrosamine-induced HCCs > 5 mm treated with embolization were included in a prospective study. In 12 rats, 3D AR visualization of preprocedural MR images was performed before embolization. Procedural metrics including catheterization time and radiation exposure were compared vs a prospective cohort of 16 rats in which embolization was performed without AR. An additional cohort of 15 retrospective cases was identified and combined with the prospective control cohort (n = 31) to improve statistical power. RESULTS: A 37% reduction in fluoroscopy time, from 11.7 min to 7.4 minutes, was observed with AR when compared prospectively, which did not reach statistical significance (P = .12); however, when compared with combined prospective and retrospective controls, the reduction in fluoroscopy time from 14.1 min to 7.4 minutes (48%) was significant (P = .01). A 27% reduction in total catheterization time, from 42.7 minutes to 31.0 minutes, was also observed with AR when compared prospectively, which did not reach statistical significance (P = .11). No significant differences were seen in dose-area product or air kerma prospectively. CONCLUSIONS: Three-dimensional AR visualization of preprocedural imaging may aid in the reduction of procedural metrics in a preclinical model of transarterial embolization. These data support the need for further studies to evaluate the potential of AR in endovascular oncologic interventions.


Assuntos
Resinas Acrílicas/administração & dosagem , Realidade Aumentada , Carcinoma Hepatocelular/terapia , Embolização Terapêutica , Gelatina/administração & dosagem , Holografia , Neoplasias Hepáticas Experimentais/terapia , Imagem por Ressonância Magnética , Animais , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/diagnóstico por imagem , Dietilnitrosamina , Feminino , Fluoroscopia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Masculino , Valor Preditivo dos Testes , Doses de Radiação , Exposição à Radiação , Ratos , Fatores de Tempo
18.
Int J Nanomedicine ; 15: 5517-5526, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801703

RESUMO

Introduction: Hypertension is a major health problem worldwide and is typically treated using oral drugs. However, the frequency of oral administration may result in poor patient compliance, and reduced bioavailability owing to the first-pass effect can also prove problematic. Methods: In this study, we developed a new transdermal-drug-delivery system (TDDS) for the treatment of hypertension using atenolol (ATE) based on poly(acrylic acid) (PAA)-decorated three-dimensional (3D) flower-like MoS2 nanoparticles (PAA-MoS2 NPs) that respond to NIR laser irradiation. The PAA-modified MoS2 NPs were synthesized and characterized using attenuated total reflection Fourier-transform infrared spectroscopy, X-ray diffraction measurements, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, and the sedimentation equilibrium method. The drug-loading efficiency and photothermal conversion effect were also explored. Results: The results showed that the colloidally stable PAA-MoS2 NPs exhibited a high drug-loading capacity of 54.99% and high photothermal conversion ability. Further, the capacity of the PAA-MoS2 NPs for controlled release was explored using in vitro drug-release and skin-penetration studies. The drug-release percentage was 44.72 ± 1.04%, and skin penetration was enhanced by a factor of 1.85 in the laser-stimulated group. Sustained and controlled release by the developed TDDS were observed with laser stimulation. Moreover, in vivo erythema index analysis verified that the PAA-MoS2 NPs did not cause skin irritation. Discussion: Our findings demonstrate that PAA-MoS2 NPs can be used as a new carrier for transdermal drug delivery for the first time.


Assuntos
Anti-Hipertensivos/administração & dosagem , Atenolol/administração & dosagem , Dissulfetos/química , Sistemas de Liberação de Medicamentos/métodos , Molibdênio/química , Nanopartículas/administração & dosagem , Resinas Acrílicas/química , Administração Cutânea , Animais , Anti-Hipertensivos/farmacocinética , Atenolol/efeitos adversos , Atenolol/farmacocinética , Sistemas de Liberação de Medicamentos/efeitos adversos , Liberação Controlada de Fármacos , Difusão Dinâmica da Luz , Eritema/induzido quimicamente , Humanos , Lasers , Masculino , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Coelhos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
19.
Chemosphere ; 261: 127687, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32750620

RESUMO

One of the major challenges facing the practical application of forward osmosis (FO) membranes is the need for high performance. Thus, the fabrication of highly permselective FO membranes is of great importance. The objective of this study was to improve the wettability/hydrophilicity of electrospun nanofiber (ESNF)-based substrates for the fabrication of nanofiber-supported thin film composite (NTFC) membranes for FO application. This study explored the impact of electrospun polyethersulfone/polyacrylonitrile (PES/PAN) nanofibers as the blend support to produce NTFC membranes. The blending of PES/PAN in the spinning dope was optimized. The blending of hydrophilic PAN (0-10 wt%) in PES affects the fiber diameter, hydrophilicity, water uptake, and roughness of the ESNF membrane substrates. Continuous thermal-rolling pretreatment was performed on the ESNF substrates prior to interfacial polymerization for polyamide active layer deposition. The results indicated that the fabricated NTFC membrane achieved significantly greater water flux (L/m2 h) while retaining a low specific salt flux (g/L) compared to traditional TFC membranes. The NTFC membrane flux increased with an increase in PAN content in the ESNF substrate. According to the FO performance results, the NTFC-10 (PES/PAN blend ratio of 90:10) exhibited optimal performance: a high water flux of 42.1 and 52.2 L/m2 h for the FO and PRO modes, respectively, and low specific salt flux of 0.27 and 0.24 g/L for the FO and PRO modes, respectively, using 1 M NaCl as the draw solution. This demonstrated the higher selectivity and water flux achieved by the developed NTFC membranes compared to the traditional TFC membranes.


Assuntos
Nanofibras/química , Polímeros/química , Sulfonas/química , Resinas Acrílicas , Interações Hidrofóbicas e Hidrofílicas , Estudos Longitudinais , Membranas Artificiais , Nylons , Osmose , Cloreto de Sódio , Água , Purificação da Água/métodos
20.
J Oral Rehabil ; 47(12): 1530-1537, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32841412

RESUMO

OBJECTIVE: To compare the manual time and preliminary clinical effects between the digital manufactured occlusal splints for sleep bruxism patients with those of traditional hard splints. METHODS: Sixteen individuals (18 to 44 y/o) with clinically diagnosed sleep bruxism were selected based on the inclusion criteria. All patients were divided into two groups, and a random control method was applied. Digital splints (test group) were designed and milled using CAD/CAM. Hard splints (control group) were made of transparent acrylic resin in laboratory office. The manual time spent including impression obtaining, splint production and clinical occlusal adjustment was recorded. A visual analog scale was used to report the subjective evaluations. The maximum depth loss and volumetric loss of the occlusal surface of splints in posterior tooth were measured. SPSS software was used for statistical analysis (P = .05). RESULTS: Comparing with control group, the manual time spent in test group was significantly less in all of three procedures (P < .001). The VAS scores for retention were not significantly different (P = .086), but the wearing comfort scores of test group were significantly higher (P < .001). Both maximum depth loss (P = .007) and volumetric loss in test group were significantly less than control group (P = .005). CONCLUSION: In the current study, the digitally manufactured splints exhibit significantly improved comfort and time efficiency than traditional hard splints. Moreover, the new milling material (PEEK) has better wear resistance than acrylic resins.


Assuntos
Bruxismo , Bruxismo do Sono , Resinas Acrílicas , Humanos , Cetonas , Placas Oclusais , Polietilenoglicóis , Bruxismo do Sono/terapia , Contenções
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