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1.
Int J Mol Sci ; 24(9)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37175664

RESUMO

The efficient degradation of organic effluent is always desirable when using advanced photocatalysts with enhanced activity under visible light. Nickel-doped indium oxide (Ni-In2O3) is synthesized via a hydrothermal route as well as its composites with reduced graphene oxide (rGO). Facile synthesis and composite formation methods lead to a well-defined morphology of fabricated nanocomposite at low temperatures. The bandgap energy of indium oxide lies in the range of 3.00-4.30 eV. Its high light absorption capacity, high stability, and non-toxicity make it a choice as a photocatalyst that is active under visible light. The transition metal Ni-doping changes the indium oxide's chemical, optical, and physicochemical properties. The Ni-In2O3 and rGO composites improved the charge transport and reduced the charge recombination. The phase analysis of the developed photocatalysts was performed using X-ray diffraction (XRD), and the morphological and structural properties were observed using advanced microscopic techniques (SEM and TEM), while UV-vis and FTIR spectroscopic techniques were used to confirm the structure and optical and chemical properties. The electrochemical properties of the photocatalysts were investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS), and the charge-transfer properties of the obtained photocatalysts and the mechanism of the photocatalytic degradation mechanism of methylene blue, a common dye used in the dyeing industry, were determined.


Assuntos
Poluentes Ambientais , Nanopartículas , Águas Residuárias , Óxidos/química , Luz , Nanopartículas/química
2.
Diagnostics (Basel) ; 13(10)2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37238220

RESUMO

In the post-pandemic era, point-of-care (POC) diagnosis of diseases is an important research frontier. Modern portable electrochemical (bio)sensors enable the design of POC diagnostics for the identification of diseases and regular healthcare monitoring. Herein, we present a critical review of the electrochemical creatinine (bio)sensors. These sensors either make use of biological receptors such as enzymes or employ synthetic responsive materials, which provide a sensitive interface for creatinine-specific interactions. The characteristics of different receptors and electrochemical devices are discussed, along with their limitations. The major challenges in the development of affordable and deliverable creatinine diagnostics and the drawbacks of enzymatic and enzymeless electrochemical biosensors are elaborated, especially considering their analytical performance parameters. These revolutionary devices have potential biomedical applications ranging from early POC diagnosis of chronic kidney disease (CKD) and other kidney-related illnesses to routine monitoring of creatinine in elderly and at-risk humans.

3.
Beilstein J Nanotechnol ; 11: 1190-1197, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32832314

RESUMO

High permittivity and breakdown strength are desired to improve the energy storage density of dielectric materials based on reinforced polymer composites. This article presents the synthesis of polythiophene-encapsulated BaTiO3 (BTO-PTh) nanoparticles via an in situ Cu(II)-catalyzed chemical oxidative polymerization of thiophene monomer on hydrothermally obtained tetragonal BTO nanocrystals. The formed core-shell-type BTO-PTh nanoparticles exhibit excellent dielectric properties with high permittivity (25.2) and low loss (0.04) at high frequency (106 Hz). A thick PTh encapsulation layer on the surface of the BTO nanoparticles improves their breakdown strength from 47 to 144 kV/mm and the energy storage density from 0.32 to 2.48 J/cm3. A 7.75-fold increase in the energy storage density of the BTO-PTh nanoparticles is attributed to simultaneously high permittivity and breakdown strength, which are excellent for potential energy storage applications.

4.
Nanoscale Res Lett ; 11(1): 377, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27558496

RESUMO

Polyvinyl alcohol (PVA)-stabilized graphene nanosheets (GNS) of lateral dimension (L) ~1 µm are obtained via liquid phase exfoliation technique to prepare its composites in the PVA matrix. These composites show low levels of reinforcements due to poor alignment of GNS within the matrix as predicted by the modified Halpin-Tsai model. Drawing these composites up to 200 % strain, a significant improvement in mechanical properties is observed. Maximum values for Young's modulus and strength are ~×4 and ~×2 higher respectively than that of neat PVA. Moreover, the rate of increase of the modulus with GNS volume fraction is up to 700 GPa, higher than the values predicted using the Halpin-Tsai theory. However, alignment along with strain-induced de-aggregation of GNS within composites accounts well for the obtained results as confirmed by X-ray diffraction (XRD) characterization.

5.
J Photochem Photobiol B ; 159: 125-32, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27054875

RESUMO

Acanthamoeba is an opportunistic protozoan pathogen that plays a pivotal role in the ecosystem. It may cause blinding keratitis and fatal encephalitis involving the central nervous system. Here we synthesized pure and Zn doped TiO2 nanoparticles (~10-30nm) via sol-gel and sol-hydrothermal methods and demonstrated its impact on the biological characteristics of pathogenic Acanthamoeba castellanii. Our results revealed that pure and Zn doped TiO2 nanoparticles synthesized by sol-hydrothermal methods (ranging 5, 10, 25 and 50µg/ml) exhibited amoebicidal effects i.e., >60% of trophozoites executed under normal light at maximum dose (50µg/ml) within 1h incubation. In contrast pure/doped TiO2 obtained via sol gel method showed ~40% amoeba damage. Furthermore, amoebae growth assay demonstrated that Zn doped TiO2 also inhibited Acanthamoeba numbers up to 7days in dose dependent manner. It was interesting to note that all the tested TiO2 nanoparticles have shown maximum amoebicidal effects at pH7 which is quite relevant to amoebic growth favorable conditions. Our results confirmed that TiO2 has inhibitory effects on Acanthamoeba growth and viability. Overall, we reported the amoebicidal and amoebic growth inhibition potential of pure and Zn doped TiO2 nanoparticles against Acanthamoeba due to attached OH(-) groups, reduced size and decreased band gap of sol hydrothermally synthesized TiO2 nanoparticles.


Assuntos
Acanthamoeba/efeitos dos fármacos , Amebicidas/farmacologia , Nanopartículas , Titânio/farmacologia , Técnicas In Vitro , Microscopia Eletrônica de Varredura
6.
Dent Mater J ; 35(1): 112-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26830831

RESUMO

The purpose of this study was to investigate the chemical composition and particle morphology of white mineral trioxide aggregate (WMTA) and two white Portland cements (CEM 1 and CEM 2). Compositional analysis was performed by energy dispersive X-ray spectroscopy, X-ray fluorescence spectrometry and X-ray diffraction whereas, morphological characteristics were analyzed by scanning electron microscope and Laser scattering particle size distribution analyzer. The elemental composition of WMTA, CEM 1 and CEM 2 were similar except for the presence of higher amounts of bismuth in WMTA. Calcium oxide and silicon oxide constitute the major portion of the three materials whereas, tricalcium silicate was detected as the major mineral phase. The particle size distribution and morphology of WMTA was finer compared to CEM 1 and CEM 2. The three tested materials had relatively similar chemical composition and irregular particle morphologies.


Assuntos
Compostos de Alumínio/química , Compostos de Cálcio/química , Cimentos Dentários/química , Óxidos/química , Silicatos/química , Bismuto/química , Combinação de Medicamentos , Teste de Materiais , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Silício/química , Espectrometria por Raios X , Propriedades de Superfície , Difração de Raios X
7.
J Mech Behav Biomed Mater ; 54: 283-94, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26479428

RESUMO

To evaluate the physical and mechanical properties of an experimental bis-GMA-based resin composite incorporated with non-silanized and silanized nano-hydroxyapatite (nHAP) fillers. Experimental bis-GMA based resin composites samples which were reinforced with nHAP fillers were prepared. Filler particles were surface treated with a silane coupling agent. Five test groups were prepared: 1. Unfilled, 2. Reinforced with 10wt% and 30wt% non-silanized nHAP fillers, and 3. Reinforced with 10wt% and 30wt% silanized nHAP fillers. The samples were subjected to tests in dry condition and in deionized water, aged at 37°C for 30 days. Prepared silanized and non-silanized nHAP were analyzed with Fourier Transform Infrared (FTIR) Spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The micro-hardness and water sorption were evaluated. Data were analyzed by one-way ANOVA (p<0.05). The samples were characterized by FTIR Spectroscopy, Thermogravimetric Analysis and Differential Scanning Calorimetry. The surface morphology of sample surfaces was examined by Scanning Electron Microscope (SEM). The results showed that the water sorption for nHAP fillers reinforced resins was significantly lower than unfilled resins. Surface hardness for resins reinforced with silane treated fillers was superior to unfilled and untreated fillers resins. The resin matrix loaded with 30wt% silanized-nHAP fillers would improve the physical and mechanical properties of a bis-GMA based resin.


Assuntos
Bis-Fenol A-Glicidil Metacrilato/química , Durapatita/química , Fenômenos Mecânicos , Fenômenos Físicos , Resinas Sintéticas/química , Silanos/química , Adsorção , Dureza , Propriedades de Superfície , Água/química
8.
J Agric Food Chem ; 63(31): 6876-82, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26194089

RESUMO

Application of engineered nanoparticles (NPs) with respect to nutrient uptake in plants is not yet well understood. The impacts of TiO2 and Fe3O4 NPs on the availability of naturally soil-bound inorganic phosphorus (Pi) to plants were studied along with relevant parameters. For this purpose, Lactuca sativa (lettuce) was cultivated on the soil amended with TiO2 and Fe3O4 (0, 50, 100, 150, 200, and 250 mg kg(-1)) over a period of 90 days. Different techniques, such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman, and Fourier transform infrared spectroscopy (FTIR) were used to monitor translocation and understand the possible mechanisms for phosphorus (P) uptake. The trends for P accumulation were different for roots (TiO2 > Fe3O4 > control) and shoots (Fe3O4 > TiO2 > control). Cystine and methionine were detected in the rhizosphere in Raman spectra. Affinities of NPs to adsorb phosphate ions, modifications in P speciation, and NP stress in the rhizosphere had possibly contributed to enhanced root exudation and acidification. All of these changes led to improved P availability and uptake by the plants. These promising results can help to develop an innovative strategy for using NPs for improved nutrient management to ensure food security.


Assuntos
Lactuca/metabolismo , Nanopartículas Metálicas/química , Fósforo/metabolismo , Solo/química , Transporte Biológico , Óxido Ferroso-Férrico/química , Lactuca/química , Fósforo/química , Rizosfera , Titânio/química
9.
Drugs Aging ; 31(10): 749-54, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25142050

RESUMO

BACKGROUND/OBJECTIVES: Patients with congestive heart failure (CHF) have a high prevalence of cognitive impairment and the association is multifactorial. In general, the burden of anticholinergic drugs has consistently been shown to be a risk factor for cognitive impairment in the elderly. The aim of this study was to assess the cognitive burden of medications in patients with CHF. DESIGN: This was a cross-sectional, retrospective, single-center study. SETTING: The study was conducted in an outpatient setting. PARTICIPANTS: Patients who presented to a comprehensive heart failure clinic during a 1-month period were included. MEASUREMENTS: The primary outcomes of interest were mean anticholinergic cognitive burden (ACB) score of all medications and CHF medications (ACB-CHF), calculated based on the ACB Scoring Scale (ACB-SS). The ACB-CHF score was further dichotomized as 0 or 1 (low anticholinergic burden) versus 2 or 3 (high anticholinergic burden). RESULTS: A total of 182 patients were included. The mean ACB and ACB-CHF scores were 2.4 (range 0-13) and 1.0 (range 0-4), respectively, while 25.8 % of patients had an ACB-CHF score of 2 or 3. There was no association found between ejection fraction in patients with systolic heart failure and the ACB (p = 0.28) or ACB-CHF (p = 0.62) score. CONCLUSION: We conclude that patients with CHF have a substantial exposure to anticholinergic medications with adverse cognitive effects. This may be another important contributor to the increased prevalence of cognitive impairment in these patients.


Assuntos
Envelhecimento , Antagonistas Colinérgicos/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Insuficiência Cardíaca/tratamento farmacológico , Idoso , Transtornos Cognitivos/epidemiologia , Estudos Transversais , Feminino , Serviços de Saúde para Idosos , Humanos , Indiana/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
Nanoscale ; 6(9): 4889-95, 2014 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-24671118

RESUMO

We have used liquid exfoliation of hexagonal Boron-Nitride (BN) to prepare composites of BN nanosheets of three different sizes in polyvinylchloride matrices. These composites show low levels of reinforcement, consistent with poor alignment of the nanosheets as-described by a modified version of Halpin-Tsai theory. However, drawing of the composites to 300% strain results in a considerable increase in mechanical properties with the maximum composite modulus and strength both ∼×3 higher than that of the pristine polymer. In addition, the rate of increase of modulus with BN volume fraction was up to 3-fold larger than for the unstrained composites. This is higher than can be explained by drawing-induced alignment using Halpin-Tsai theory. However, the data was consistent with a combination of alignment and strain-induced de-aggregation of BN multilayers.

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