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1.
Nanotechnology ; 34(38)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37336199

RESUMO

The superior properties, such as large interlayer spacing and the ability to host large alkali-metal ions, of two-dimensional (2D) materials based on transition metal di-chalcogenides (TMDs) enable next-generation battery development beyond lithium-ion rechargeable batteries. In addition, compelling but rarely inspected TMD alloys provide additional opportunities to tailor bandgap and enhance thermodynamic stability. This study explores the sodium-ion (Na-ion) and potassium-ion (K-ion) storage behavior of cation-substituted molybdenum tungsten diselenide (MoWSe2), a TMD alloy. This research also investigates upper potential suspension to overcome obstacles commonly associated with TMD materials, such as capacity fading at high current rates, prolonged cycling conditions, and voltage polarization during conversion reaction. The voltage cut-off was restricted to 1.5 V, 2.0 V, and 2.5 V to realize the material's Na+and K+ion storage behavior. Three-dimensional (3D) surface plots of differential capacity analysis up to prolonged cycles revealed the convenience of voltage suspension as a viable method for structural preservation. Moreover, the cells with higher potential cut-off values conveyed improved cycling stability, higher and stable coulombic efficiency for Na+and K+ion half-cells, and increased capacity retention for Na+ion half-cells, respectively, with half-cells cycled at higher voltage ranges.


Assuntos
Potássio , Sódio , Cátions , Ligas , Fontes de Energia Elétrica
2.
Drug Dev Ind Pharm ; 47(1): 12-21, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33190552

RESUMO

OBJECTIVE: The poly D, L-Lactic-co-glycolic acid (PLGA) and Polycaprolactone (PCL) have been widely applied for developing the prolonged-release formulation. The current study explores the application of these polymers for developing prolonged-release nanosphere of Duloxetine (DLX). Developing a prolonged release parenteral nanosphere formulation of DLX would be overcoming pitfalls like acid-labile degradation, first-pass metabolism and erratic bioavailability along with long-term therapeutic benefit in the treatment of depression. METHODS: DLX-loaded PLGA and PCL nanospheres were prepared by using the emulsion solvent evaporation technique. The developed formulation was compared with DLX oral solution concerning brain estimation. The prepared nanospheres were subjected to the morphology of the drug particles, polydispersity Index (PDI), distribution size, zeta potential, entrapment efficiency and percentage yield to generate a proof of concept. RESULTS: DLX-loaded polymeric nanosphere exhibited the uniform size from 89.48 nm to 100.9 nm. The entrapment efficiency was in the range of 74.93 to 77.49, respectively, of PLGA and PCL formulation. The FSEM image affirmed smooth spherical morphology. A good PDI and negative zeta potential value (-31.3 mV for F1 and -30.7 mV for F2) supported the stability of the nanosphere. The brain concentration of the drug was three times enhanced supporting the effectiveness of the nanosphere during pharmacodynamic and pharmacokinetic studies. CONCLUSION: The intramuscular DLX-loaded nanospheres signify improved brain availability relative to DLX solution. This can be a blueprint for the effective and targeted brain delivery of CNS drugs.


Assuntos
Cloridrato de Duloxetina/química , Nanopartículas , Nanosferas , Portadores de Fármacos , Ácido Láctico/química , Polímeros/química
3.
J Contemp Dent Pract ; 17(5): 349-53, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-27443359

RESUMO

BACKGROUND: The purpose of this research was to assess the antibacterial activity of a new bioceramic pulp capping material (endosequence root repair material [ERRM]) against the main cariogenic bacteria: Salivary mutans streptococci (MS) and lactobacilli and compare the results with mineral trioxide aggregate (MTA) and calcium hydroxide (Dycal). MATERIALS AND METHODS: The isolation of MS group bacteria and Lactobacillus (LB) spp. from stimulated saliva was performed with in-office caries risk test bacteria dip slide test. Endosequence root repair material, MTA (ProRoot MTA), and Dycal were used as pulp capping materials. Mutans Streptococci and LB were scattered on the agar dishes with a swab. The pulp capping materials under study were placed in the wells and prepared in the agar, immediately after mixing. The dishes were incubated for 24 hours at 37°C. The growth inhibition zones were recorded and compared for every material and bacterial strain. One-way analysis of variance test was done to compare the development of growth inhibition of selected bacteria against testing materials. Post hoc Tukey honest significant difference was conducted to compare each material group. RESULTS: All the three selected pulp capping materials were found to inhibit the bacteria LB and MS. The antibacterial activity of ERRM and ProRoot MTA was significantly better than the Dycal. Against MS, ERRM and MTA showed no statistically significant difference. Mineral trioxide aggregate showed significantly better inhibitory activity against LB. CONCLUSION: Endosequence root repair material and MTA had superior antibacterial properties against the main cariogenic bacteria: MS and LB compared with Dycal. CLINICAL SIGNIFICANCE: A pulp-capping agent having good antibacterial properties can have better success rate in maintaining the vitality of the tooth while treating deep carious lesions in patients.


Assuntos
Antibacterianos , Capeamento da Polpa Dentária , Streptococcus mutans , Antibacterianos/farmacologia , Fosfatos de Cálcio , Cimentos Dentários/farmacologia , Combinação de Medicamentos , Humanos , Lactobacillus/efeitos dos fármacos , Óxidos , Agentes de Capeamento da Polpa Dentária e Pulpectomia , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos , Streptococcus mutans/efeitos dos fármacos
4.
J Contemp Dent Pract ; 17(7): 553-6, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27595721

RESUMO

AIMS: The aim of the study was to compare the antimicrobial property of newly introduced EndoSequence BC sealer with commonly used zinc oxide-eugenol-based sealer (Zical) and epoxy resin-based sealer (MM-Seal) against Candida albicans, Lactobacillus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. MATERIALS AND METHODS: The agar diffusion test was done to measure the antimicrobial activity of sealers. The sealers were put in the 4 mm wells prepared in the inoculated agar plates. The agar plates were incubated at 37°C for 24 hours and the zones of inhibition that appeared was measured. Chi-square test was done to evaluate intraobserver bias for all study samples. Intergroup comparison was done for all five parameters using Pearson correlation statistical analysis. RESULTS: EndoSequence BC sealer showed maximum mean of diameter of zones of inhibition against all the microorganisms but with no statistically significant difference with other sealers. Zical did not show any zone of inhibition against the P. aeruginosa. MM-Seal did not show any inhibitory activity against the P. aeruginosa and C. albicans. CONCLUSION: EndoSequence BC sealer showed antimicrobial activity against all the microorganisms and proved to be a better choice when compared with other two sealers. CLINICAL SIGNIFICANCE: Antimicrobial properties of endodontic sealers are important to prevent the persistent infection of the complex root canals. EndoSequence BC sealer has been proved to be a better sealer in this aspect.


Assuntos
Anti-Infecciosos/farmacologia , Fosfatos de Cálcio/farmacologia , Resinas Epóxi/farmacologia , Óxidos/farmacologia , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos/farmacologia , Cimento de Óxido de Zinco e Eugenol/farmacologia , Candida albicans/efeitos dos fármacos , Combinação de Medicamentos , Escherichia coli/efeitos dos fármacos , Técnicas In Vitro , Lactobacillus/efeitos dos fármacos , Teste de Materiais , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
5.
Soft Matter ; 11(25): 5154-67, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26053660

RESUMO

Block-copolymer orientation in thin films is controlled by the complex balance between interfacial free energies, including the inter-block segregation strength, the surface tensions of the blocks, and the relative substrate interactions. While block-copolymer lamellae orient horizontally when there is any preferential affinity of one block for the substrate, we recently described how nanoparticle-roughened substrates can be used to modify substrate interactions. We demonstrate how such 'neutral' substrates can be combined with control of annealing temperature to generate vertical lamellae orientations throughout a sample, at all thicknesses. We observe an orientational transition from vertical to horizontal lamellae upon heating, as confirmed using a combination of atomic force microscopy (AFM), neutron reflectometry (NR) and rotational small-angle neutron scattering (RSANS). Using molecular dynamics (MD) simulations, we identify substrate-localized distortions to the lamellar morphology as the physical basis of the novel behavior. In particular, under strong segregation conditions, bending of horizontal lamellae induce a large energetic cost. At higher temperatures, the energetic cost of conformal deformations of lamellae over the rough substrate is reduced, returning lamellae to the typical horizontal orientation. Thus, we find that both surface interactions and temperature play a crucial role in dictating block-copolymer lamellae orientation. Our combined experimental and simulation findings suggest that controlling substrate roughness should provide a useful and robust platform for controlling block-copolymer orientation in applications of these materials.


Assuntos
Nanopartículas/química , Transição de Fase , Polímeros/química , Temperatura de Transição , Calefação , Simulação de Dinâmica Molecular , Nanopartículas/ultraestrutura , Difração de Nêutrons , Espalhamento a Baixo Ângulo , Propriedades de Superfície
6.
Surg Today ; 45(11): 1378-84, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25381486

RESUMO

PURPOSE: To compare the efficacy of chlorhexidine-gluconate versus povidone iodine in preoperative skin preparation in the prevention of surgical site infections (SSIs) in clean-contaminated upper abdominal surgeries. METHODS: This was a prospective randomized controlled trial conducted on patients undergoing clean-contaminated upper abdominal surgeries. A total of 351 patients 18-70 years old were randomized into two groups; chlorhexidine and povidone iodine skin preparation before surgery. RESULTS: The incidence of SSIs in the chlorhexidine group was 10.8 %, in comparison to 17.9 % in the povidone iodine group. The odds ratio was 0.6 in favor of chlorhexidine use, but the results were not statistically significant (P = 0.06). In the first postoperative week, SSIs developed in 7 % of patients in the chlorhexidine group and 14.1 % in the povidone iodine group (P = 0.03), and in the second postoperative week, SSIs were present in 4.1 % of the patients in the chlorhexidine group and 4.4 % in the povidone iodine group, which was not statistically significant (P = 0.88). CONCLUSIONS: The incidence of SSIs after clean-contaminated upper abdominal surgeries was lower with the use of chlorhexidine skin preparation than with povidone iodine preparation, although the results were not statistically significant. However, the odds ratio between the two groups favored the use of chlorhexidine over povidone iodine for preventing SSIs.


Assuntos
Abdome/cirurgia , Anti-Infecciosos Locais/administração & dosagem , Clorexidina/análogos & derivados , Povidona-Iodo/administração & dosagem , Cuidados Pré-Operatórios , Pele/microbiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Administração Tópica , Adolescente , Adulto , Idoso , Clorexidina/administração & dosagem , Humanos , Incidência , Pessoa de Meia-Idade , Estudos Prospectivos , Soluções , Infecção da Ferida Cirúrgica/epidemiologia , Adulto Jovem
7.
Macromol Rapid Commun ; 34(20): 1642-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24105959

RESUMO

Sharp dynamic thermal gradient (∇T ≈ 45 °C mm(-1)) field-driven assembly of cylinder-forming block copolymer (c-BCP) films filled with PS-coated gold nanoparticles (AuNPs; dNP ≈ 3.6 nm, φNP ≈ 0-0.1) is studied. The influence of increasing AuNP loading fraction on dispersion and assembly of AuNPs within c-BCP (PS-PMMA) films is investigated via both static and dynamic thermal gradient fields. With φNP increasing, a sharp transition from vertical to random in-plane horizontal cylinder orientation is observed due to enrichment of AuNPs at the substrate side and favorable interaction of PMMA chains with gold cores. Furthermore, a detachable capping elastomer layer can self-align these random oriented PMMA microdomains into unidirectional hybrid AuNP/c-BCP nanolines, quantified with an alignment order parameter, S.


Assuntos
Nanopartículas Metálicas/química , Polímeros/química , Ouro/química , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Polimetil Metacrilato/química , Poliestirenos/química
8.
PLoS One ; 18(2): e0281418, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36809361

RESUMO

A variety of materials, including waste and rubber products, have been used in road construction to improve the performance of bituminous pavements. The present investigation is focused on modifying bitumen using Nitrile rubber (NBR) with different thermosets namely Bakelite (B), Furan Resin (FR), and Epoxy resin (ER). The emphasis of the problem is to arrive at a mix to achieve maximum Marshall Stability (MS) and minimum flow value of Modified Bituminous Concrete. Taguchi DOE technique has been used to design the experiments using Minitab software. Analysis of Variance (ANOVA) and Multi-objective optimization has been performed using the desirability approach in Design expert software. ANOVA analysis predicts that NBR, B, ER, and FR are the major significant parameters for Marshall Stability (MS) and Flow Value (FV). It has also been analyzed from SEM and EDS images of modified bitumen that sample S1 (5% NBR, 10% Bakelite, 10% FR, 2.5% ER) has a fine surface with small pores as compared to sample S34 (10% NBR, 0% Bakelite 10% FR, 2.5% ER). Multi-optimization results suggested the optimal conditions are achieved at NBR-7.6%, Bakelite-4.8%, FR-2.5%, and ER-2.6% for MS and FV. The maximum MS is 14.84 KN and the minimum FV is 2.84 mm is obtained using optimum conditions. To validate the optimization results, the confirmation runs have been conducted, and obtained results are within 5% error with optimal conditions.


Assuntos
Resinas Epóxi , Borracha , Análise de Variância , Nitrilas , Resinas Vegetais
9.
Br Dent J ; 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36473977

RESUMO

Introduction/objectives Radiotherapy (RT) has a detrimental effect on the histomorphology of oral tissues. Patients undergoing RT are at risk of developing macrovascular and microvascular changes, which can lead to significant clinical consequences. Despite advances in RT delivery systems, radiation injury remains a modern-day clinical problem. The aim of this systematic review is to investigate the available evidence regarding the impact of RT to the dental pulp and the clinical manifestations of these effects.Data and sources A multi-database search (PubMed, Medline, Embase and CINAHL) was performed to identify related papers published from inception until November 2021. An additional manual search was performed to identify further articles. The data extracted from relevant papers were analysed according to the outcomes selected in this review.Study selection The search generated seven articles eligible for analysis with a total of 2,709 teeth included. RT dose exposure ranged from 30-71.2 Gray with a common finding that RT decreases the number of teeth responding to pulp sensibility testing.Conclusions Knowledge related to the impact of RT on dental pulp is limited and based on weak evidence and a low-level quality of studies. Future studies should incorporate exact RT doses to the teeth and use replicable pulpal testing methods. Understanding the pulpal status post-RT remains an important consideration as dental extractions should be avoided in this cohort due to the risk of osteoradionecrosis.

10.
Curr Drug Deliv ; 20(1): 75-88, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35490322

RESUMO

BACKGROUND: Nowadays, biomedical research has been focusing on the design and development of new drug delivery systems that provide efficient drug targeting. The molecularly imprinted polymers (MIPs) have attracted wide interest and play an indispensable role as a drug carrier. Drug delivery systems based on MIPs have been frequently cited in the literature. They are cross-linked polymers that contain binding sites according to the complementary structure of the template molecules. They possess distinctive features of structure predictability and site recognition specificity. Versatile applications of MIPs include purification, biosensing, bioseparation, artificial antibodies, and drug delivery. An ideal MIPs should include features such as biocompatibility, biodegradability, and stability. OBJECTIVE: In this article, we elaborate on the historic growth, synthesis, and preparation of different MIPs and present an updated summary of recent advances in the development of new drug delivery systems which are based on this technique. Their potential to deliver drugs in a controlled and targeted manner will also be discussed. CONCLUSION: MIPs possess unique advantages, such as lower toxicity, fewer side effects, and good therapeutic potential. They offer administration of drugs by different routes, i.e., oral, ocular or transdermal. Despite several advantages, biomedical companies are hesitant to invest in MIPs based drug delivery systems due to the limited availability of chemical compounds.


Assuntos
Sistemas de Liberação de Medicamentos , Impressão Molecular , Polímeros Molecularmente Impressos , Portadores de Fármacos/química , Portadores de Fármacos/normas , Sistemas de Liberação de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/tendências , Polímeros Molecularmente Impressos/química , Polímeros Molecularmente Impressos/normas
11.
ACS Sens ; 6(11): 4145-4155, 2021 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-34735765

RESUMO

In this research, a highly sensitive and selective hydrogen gas sensor was developed based on Cu-doped SnO2. Sensing characteristics were compared based on SnO2 doped with different concentrations of Cu, and the highest sensitivity and fastest response time were shown when 3% Cu was contained. A 3D structure was formed using a polystyrene to increase the surface-to-volume ratio, which allows more oxygen molecules to bond with the surface of the SnO2 sensing material. Extremely increased sensitivity was observed as compared to the planar structure. A temperature sensor and micro-heater were integrated into the sensor, and the surface temperature was maintained constant regardless of external influences. In addition, an electronic sensor interface was developed for the efficient analysis of real-time data. The developed sensor was wire-bonded to the flexible printed circuit board (FPCB) cable and connected with the sensor interface. Sensitivity and linearity measured based on the developed sensor and interface system were analyzed as 0.286%/ppm and 0.98, respectively, which were almost similar to the results observed by a digital multimeter (DMM). This indicates that our developed sensor system can be a very promising candidate for real-time measurement and can be applied in various fields. The enhanced sensitivity of 3% doped SnO2 toward hydrogen is attributed to the huge number of oxygen vacancies in the doped sample.


Assuntos
Materiais Inteligentes , Compostos de Estanho , Eletrônica , Hidrogênio , Temperatura
12.
ACS Appl Mater Interfaces ; 13(19): 22914-22925, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-33956429

RESUMO

A flexible poly(vinylidene difluoride) (PVDF) composite film embedding LiNbO3 ceramics decorated with silver nanoparticles (Ag NPs) has been synthesized using the solvent casting method. The polar ß-phase, Ag NPs, and LiNbO3 phases were confirmed in the composite film using various characterization methods. The composite film showed promising degradation of cationic and anionic dyes using piezocatalysis under ultrasonication. Moreover, this composite film also effectively degraded two model pharmaceutical pollutants named tetracycline and ciprofloxacin using piezocatalysis under ultrasonication. In addition to this, this composite film piezocatalytically removed more than 99.999% of Escherichia coli and 96.65% of Staphylococcus aureus bacteria within 180 min of sonication. The piezocatalytic performance of the PVDF composite film embedding Ag-loaded LiNbO3 in all three applications was superior to that obtained in the case of the PVDF film embedding LiNbO3 and the bare PVDF film. This demonstrates the pronounced effect of Ag NPs in the increase of piezocatalytic activity in the composite film.


Assuntos
Bactérias/efeitos dos fármacos , Corantes/química , Nióbio/química , Óxidos/química , Preparações Farmacêuticas/química , Polivinil/química , Prata/química , Catálise , Desinfecção
13.
Hepatobiliary Pancreat Dis Int ; 9(1): 88-92, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20133236

RESUMO

BACKGROUND: Endoscopic palliation in malignant hilar biliary obstruction requires endoscopic retrograde cholangiopancreatography (ERCP), whereas contrast injection leads to cholangitis. Contrast-free metal stenting with or without magnetic resonance cholangiopancreatography (MRCP) has shown encouraging results, but MRCP and metal stents are costly. There have been no reports on the use of air cholangiography. METHODS: We prospectively evaluated the role of air cholangiography-assisted unilateral plastic stenting in 10 patients with type II malignant hilar biliary obstruction. A retrospectively analysed group of 10 patients treated with contrast-free unilateral metal stenting served as historical controls. RESULTS: Ten patients with unresectable type II malignant hilar biliary obstruction were studied. Air cholangiography detected type II obstruction in all patients, similar to MRCP. The patients underwent unilateral stenting. Successful endoscopic drainage was achieved in all patients. The mean patency of the stent was 95.8+/-17.5 days in the study group and 143.9+/-115.1 days in the control group (P=0.20). The mean survival was 121.8+/-41.6 days in the study group and 154.9+/-122.5 days in the control group (P=0.42). Kaplan-Meier analysis showed an estimated median survival of 100:95% CI (65.9, 134.1) days in the study group and 98:95% CI (84.1, 111.9) days in the control group (P=0.62). Cholangitis occurred in none of the patients and there were no 30-day deaths nor major complications. Air cholangiography-assisted unilateral plastic stenting was cheaper than contrast-free unilateral metal stenting. CONCLUSION: Air cholangiography-assisted unilateral plastic stenting is as safe and effective as contrast-free unilateral metal stenting in type II malignant hilar biliary obstruction for palliating patients, but it is cheaper.


Assuntos
Neoplasias dos Ductos Biliares/cirurgia , Colangiografia/métodos , Colestase/cirurgia , Plásticos , Stents , Adulto , Neoplasias dos Ductos Biliares/complicações , Colangiografia/efeitos adversos , Colangiografia/economia , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica/economia , Colangiopancreatografia por Ressonância Magnética/efeitos adversos , Colangiopancreatografia por Ressonância Magnética/economia , Colangite/induzido quimicamente , Colestase/etiologia , Meios de Contraste/efeitos adversos , Análise Custo-Benefício , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Metais , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
14.
Int J Biol Macromol ; 151: 519-528, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32088225

RESUMO

In this study, bioglass (BG)­iron oxide (Fe3O4) nanocomposite coating was developed to produce bioactive and antibacterial coatings. The nanocomposite coating was embedded in chitosan (CS) matrix and coating was fabricated by electrophoretic deposition (EPD) method. The coating was characterized by using SEM/EDX and XRD respectively. The experiment was performed with three varying concentrations (1, 3, 5 (wt%)) of Fe3O4 nanoparticles prepared by the co- precipitation method in the bioactive glass coating. The antibacterial activity was examined in Escherichia coli and Staphylococcus aureus bacteria which determine that the growth of microorganisms was inhibited with the progressive increment of Fe3O4 nanoparticles. The bioactivity assessment was done in PBS for 7 days and it was detected that the composite coatings improve the bone-bonding ability which was again confirmed by SEM-EDX. The corrosion behavior was evaluated in Ringer's solution by electrochemical test. The corrosion analysis revealed that the BG-1% Fe3O4 nanocomposite coating has superior corrosion resistance as compared to the other coatings. The findings of the research have shown that the BG-Fe3O4-CS nanocomposite coating can be widely used as a suitable material for orthopedic applications.


Assuntos
Ligas/química , Cerâmica/química , Quitosana/química , Materiais Revestidos Biocompatíveis , Magnésio/química , Nanopartículas Magnéticas de Óxido de Ferro/química , Nanocompostos/química , Antibacterianos/química , Antibacterianos/farmacologia , Nanopartículas Magnéticas de Óxido de Ferro/ultraestrutura , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Análise Espectral
15.
Proc Inst Mech Eng H ; 234(2): 232-242, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31804148

RESUMO

Nano-hydroxyapatite powder was used in electric discharge machining to modify the surface of Ti-6Al-4V medical alloy. Herein, electric discharge machining was performed, with and without powder-mixed flushing for evaluation of the material erosion rate and surface roughness. In addition to dielectric type, several process parameters including current, pulse-on duration, pulse-off duration, and electrode hole diameter were considered. The experiments were planned by Taguchi design technique and conducted to analyze the material erosion rate and surface roughness. After machining, scanning electron microscope, energy-dispersive X-ray spectrometry, and X-ray diffraction techniques were used to evaluate the surfaces of the samples. Furthermore, wear and corrosion tests were also carried out on the Ti alloy with modified surfaces. The influential factors were identified based on analysis of variance results. Current and dielectric type were the significant factors, both for the material erosion rate and surface roughness. The scanning electron microscope images of Ti-6Al-4V samples highlighted that the process parameters exhibited a vital influence on the topology and microstructure of machined surface. Furthermore, energy-dispersive X-ray spectrometry and X-ray diffraction analyses confirmed the presence of hydroxyapatite on Ti alloy surface after machining. Moreover, the results of wear and corrosion tests revealed lower wear and corrosion rates of the surface-treated workpiece with nano-hydroxyapatite.


Assuntos
Materiais Biocompatíveis/química , Durapatita/química , Titânio/química , Ligas , Eletroquímica , Eletrodos , Nanoestruturas/química , Desenho de Prótese
16.
Hip Int ; 28(6): 573-583, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29998768

RESUMO

Ultra-high molecular weight polyethylene (UHMWPE) continues to be the gold standard bearing surface in total hip arthroplasty (THA) for nearly 5 decades. Highly cross-linked UHMWPE (HXLPE) was adapted for routine use in the early 2000s to reduce the revision rates related to wear, osteolysis, and aseptic loosening resulting from conventional UHMWPE wear. Since its inception, consistent evidence showing reduced wear rates and osteolysis supports the use of HXLPE in THA. High quality studies demonstrating the advantage in long term survivorship of HXLPE over conventional UHMWPE are emerging. Though retrieval studies have demonstrated evidence of in vivo oxidation and fatigue related damage at the rim of the first generation HXLPE liners, clinical significance of this remains to be seen. Second-generation sequentially annealed and vitamin E containing HXLPE liners demonstrate improved mechanical properties, resistance to oxidation, and equivalent wear rates in comparison to their first-generation counterparts, but long term success remains to be seen.


Assuntos
Artroplastia de Quadril/instrumentação , Prótese de Quadril , Polietilenos , Desenho de Prótese , Humanos , Falha de Prótese
17.
Acta Cytol ; 51(4): 621-3, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17718138

RESUMO

BACKGROUND: Multifocal nodular oncocytic hyperplasia (MNOH) is a rare lesion of the parotid gland. Fine needle aspiration cytology (FNAC) in MNOH has not been described previously to the best of our knowledge. CASE: A 55-year-old woman presented with a lump at the left angle of her mouth for 2 months. Local examination revealed a hard, nontender parotid mass. FNAC revealed clusters as well as discretely lying oncocytic cells. cells at places showed moderate nuclear pleomorphism. The features were consistent with a diagnosis of oncocytic neoplasm neoplasm; however, because of pleomorphism, a suspicion of carcinoma was offered. The patient underwent superficial parotidectomy, and histopathology examination revealed it to be multifocal nodular oncocytic hyperplasia. CONCLUSION: MNOH is a rare nonneoplastic salivary gland lesion and should be considered in the differential diagnosis of oncocytic neoplasm on FNAC.


Assuntos
Células Oxífilas/patologia , Glândula Parótida/patologia , Biópsia por Agulha Fina , Células Epiteliais/patologia , Feminino , Humanos , Hiperplasia , Pessoa de Meia-Idade , Mitocôndrias/ultraestrutura , Células Oxífilas/ultraestrutura , Glândula Parótida/ultraestrutura
18.
Clin Nucl Med ; 42(5): 335-340, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28263210

RESUMO

PURPOSE: The aim of this study was to evaluate the incremental value of cocktail F-FDG/F-NaF PET/CT over F-FDG PET/CT alone for detection of skeletal metastases in breast cancer patients. METHODS: Seventy patients with locally advanced/recurrent breast cancer were prospectively included. All patients underwent whole-body F-FDG PET/CT and cocktail F-FDG/F-NaF PET/CT within a span of 1 week. Both studies were evaluated to detect presence of skeletal/marrow metastases on PET/CT images by 2 nuclear medicine physicians. Clinical and radiological correlation/follow-up was used as criterion standard. RESULTS: Of 70 patients, 50 (71.0%) had locally advanced breast cancer, and 20 had recurrent breast cancer. On patient-wise analysis, both cocktail PET/CT and F-FDG PET/CT identified skeletal/marrow lesions in 23 (32.8%) of 70 patients. In 8 patients (11.4%), only cocktail PET/CT identified skeletal/marrow lesions, whereas F-FDG PET/CT was negative. In the rest of the 39 patients (55.8%), no skeletal/marrow lesion was identified on both scans. Good correlation was noted between cocktail PET/CT and F-FDG PET/CT results (r = 0.785, P < 0.0001). Cocktail PET/CT detected lesions in significantly more number of patients than F-FDG PET/CT alone (P = 0.007). On lesion-wise analysis, cocktail PET/CT detected more number of lesions in 20 patients as compared with F-FDG-PET/CT alone. Both scans detected same number of lesions in the rest of 11 patients with positive findings. A total of 32 additional lesions were identified on cocktail PET/CT imaging as compared with F PET/CT alone (P < 0.0001). CONCLUSIONS: Cocktail F-FDG and F-NaF PET/CT is superior to F-FDG PET/CT alone for the detection of skeletal/marrow metastases in breast cancer. It can be a better alternative to F-FDG PET/CT alone in facilities where both tracers are available.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Neoplasias da Mama/patologia , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Fluoreto de Sódio , Adulto , Idoso , Feminino , Radioisótopos de Flúor , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estudos Prospectivos
19.
Eur J Dent ; 10(3): 366-369, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27403055

RESUMO

OBJECTIVE: Our goal of the study was to evaluate the antibacterial properties of endodontic sealers against the E. faecalis. MATERIALS AND METHODS: Six millimeters wells were made for each material in all the preinoculated petri plates. Then, the petri plates were incubated for 24 h. The zones of inhibition appeared were measured, and the measurements were put to statistical analysis. RESULTS: EndoSequence BC Sealer, MM-mineral trioxide aggregate (MTA), and ProRoot MTA showed maximum means of diameter of zones of inhibition, whereas MM-seal and Endoseal did not show any zones of inhibition. CONCLUSION: EndoSequence BC Sealer was found to be a better endodontic sealer as compared to resin-based and zinc oxide-eugenol-based sealer.

20.
Sci Rep ; 6: 20419, 2016 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-26842915

RESUMO

Skulls are amongst the most informative documents of evolutionary history but a complex geometry, coupled with composite material properties and complicated biomechanics, have made it particularly challenging to identify mechanical principles guiding the skull's morphogenesis. Despite this challenge, multiple lines of evidence, for example the relationship between masticatory function and the evolution of jaw shape, nonetheless suggest that mechanobiology plays a major role in skull morphogenesis. To begin to tackle this persistent challenge, cellular, molecular and tissue-level analyses of the developing mouse palate were coupled with finite element modeling to demonstrate that patterns of strain created by mammalian-specific oral behaviors produce complementary patterns of chondrogenic gene expression in an initially homogeneous population of cranial neural crest cells. Neural crest cells change from an osteogenic to a chondrogenic fate, leading to the materialization of cartilaginous growth plate-like structures in the palatal midline. These growth plates contribute to lateral expansion of the head but are transient structures; when the strain patterns associated with suckling dissipate at weaning, the growth plates disappear and the palate ossifies. Thus, mechanical cues such as strain appear to co-regulate cell fate specification and ultimately, help drive large-scale morphogenetic changes in head shape.


Assuntos
Animais Lactentes/crescimento & desenvolvimento , Crista Neural/citologia , Palato/crescimento & desenvolvimento , Animais , Evolução Biológica , Fenômenos Biomecânicos , Análise de Elementos Finitos , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Modelos Biológicos
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