Jacopo Emilio Giaretta  Farshad Oveissi  Fariba Dehghani  Sina Naficy 《Advanced Materials Technologies》2021,6(4):2001148

Detecting hydrogen peroxide (H₂O₂) as the side product of enzymatic reactions is of great interest in food and medical applications. Despite the advances in this field, the majority of reported H₂O₂ sensors are bulky, expensive, limited to only one phase detection (either gas or liquid), and require multistep fabrications. This article aims to address some of these limitations by presenting a 3D printable paper-based sensor made from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) decorated with horseradish peroxidase, an enzyme able to interact with H₂O₂. Unlike most electrochemical PEDOT:PSS-based H₂O₂ sensors with voltametric or potentiometric mechanisms, the sensing mechanism in this technology is impedimetric, significantly simplifying the fabrication process. Here, the resistance of sensors proportionally changes with H₂O₂ concentration upon exposure to liquid or gas with a linear trend within the range of 61.3 × 10⁻⁹ and 61.3  ×  10⁻⁶ m H₂O₂. The observed correlation between the resistance and H₂O₂ concentration is highly dependent on the level of integrated enzyme, suggesting the direct contribution of horseradish peroxidase in the co-redoxing of PEDOT:PSS in the presence of H₂O₂. Raman and UV–vis spectroscopies also confirm the structural change of PEDOT in the presence of H₂O₂ which is facilitated by the enzyme.  相似文献   

    

Sahar Dehghani  Mohammad Haghighi  Neda Vardast 《国际能源研究杂志》2019,43(8):3779-3793

In present work, the aim of producing biodiesel from waste cooking oil was pursued by doping the cerium element into the MCM‐41 framework as catalyst with various Si/Ce molar ratio (5, 10, 25, 50, and Ce = 0). The catalytic performance and stability improved by employing the ultrasound irradiation in active phase loading step of catalyst preparation. The physicochemical characteristics of synthesized samples were investigated using various techniques as follows: Brunauer‐Emmett‐Teller (BET), X‐ray powder diffraction (XRD), Fourier transfer infrared (FTIR), energy‐dispersive X‐ray spectroscopy (EDX), transmission electron microscopy (TEM), and field emission scanning electron microscope (FESEM). The XRD patterns along with the results of FTIR and BET analysis revealed the MCM‐41 framework destruction while increasing the Ce content. The FESEM images of the nanocatalysts illustrated a well distribution and uniform morphology for the Ca/CeM (Si/Ce = 25). The particle size and size distribution of the Ca/CeM (Si/Ce = 25) were subsequently determined by TEM and FESEM images. The activity of fabricated nanocatalysts was evaluated by measuring the free acid methyl ester (FAME) content of produced biodiesel. The tests were carried out at constant operational conditions: T = 60°C, catalyst loading = 5 wt%, methanol/oil molar ratio = 9, and 6‐hour reaction time. A superior activity was observed for Ca/CeM (Si/Ce = 25) among other nanocatalysts with 96.8% conversion of triglycerides to biodiesel. The mentioned sample was utilized in five reaction cycles, and at the end of the fifth cycle, the conversion reached to 91.5% which demonstrated its significant stability.  相似文献   

    

Mostafa Dehghani 《Numerical Heat Transfer, Part A: Applications》2019,75(9):627-645

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Hesam Dehghani  Mahsa Zangeneh 《Energy Sources, Part B: Economics, Planning, and Policy》2018,13(7):328-339

The importance of crude oil in the world economy has made it imperative for efficient models to be designed for predicting future prices. This paper proposes an alternative approach based on a time series and biogeography-based optimization (BMMR–BBO) for the estimation of the West Texas Intermediate (WTI) crude oil price. To evaluate the forecasting ability of the presented model, we compared its performance with those of time series functions. The results of the experiment showed that BMMR-BBO performed better than the other methods and is a fairly good option for crude oil price prediction. The proposed model can be useful in the formulation of policies related to international crude oil price estimations, development plans, and industrial production.  相似文献   

    

K. R. Sultana  S. R. Dehghani  K. Pope  Y. S. Muzychka 《Numerical Heat Transfer, Part B: Fundamentals》2018,73(3):129-145

This article reviews several mathematical formulations including the corresponding boundary conditions for numerical predictions of solidification and melting. Emphasis is on techniques that are used in solving solid–liquid interface phenomena. The fixed grid enthalpy method is reviewed based on the solution techniques of conduction and convection related phase change problems. Variable grid methods are categorized and then analyzed based on their accuracy, computational efforts and convergence characteristics. The article concludes with some guidance for selecting the accurate solution techniques for solving solidification and melting problems.  相似文献   

    

Emma M. Meeus  Jan Novak  Hamid Dehghani  Andrew C. Peet 《Magma (New York, N.Y.)》2018,31(2):269-283

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Milad Dehghani 《Behaviour & Information Technology》2018,37(2):145-158

Nowadays, smart wearable technology comes up to different sectors and is gaining momentum to be implemented in everyday objects. Smartwatches are the most popular type of wearable devices. The current study attempts to understand the motivational factors of consumers’ continuous intention to use smartwatches. In particular, a netnography research has been conducted and consumers’ opinions on smartwatches on Amazon have been analysed. Eight key determinants of continuous usage intention of smartwatches have been identified. Some of them (healthology, complementary goods and enabling technologies) were not included in previous technology adoption models, highlighting that existing models need to be updated when it comes in the domain of continuous usage intention of wearable technologies.  相似文献   

    

Mehdi Dehghani  Kilean Lucas  Jonathan Flax  James McGrath  Thomas Gaborski 《Advanced Materials Technologies》2019,4(11)

Membranes have been used extensively for the purification and separation of biological species. A persistent challenge is the purification of species from concentrated feed solutions such as extracellular vesicles (EVs) from biological fluids. Investigated is a new method to isolate micro‐ and nanoscale species termed tangential flow for analyte capture (TFAC), which is an extension of traditional tangential flow filtration. Initially, EV purification from plasma on ultrathin nanomembranes is compared between both normal flow filtration (NFF) and TFAC. NFF results in rapid formation of a protein cake which completely obscures any captured EVs and also prevents further transport across the membrane. On the other hand, TFAC shows capture of CD63 positive small EVs with minimal contamination. The use of TFAC to capture target species over membrane pores, wash, and then release in a physical process that does not rely upon affinity or chemical interactions is explored. This process is studied with model particles on both ultrathin and conventional thickness membranes. Successful capture and release of model particles is observed using both membranes. Ultrathin nanomembranes show higher efficiency of capture and release with significantly lower pressures indicating that ultrathin nanomembranes are well‐suited for TFAC of delicate nanoscale particles such as EVs.  相似文献   

    

Roozbeh Abolpour  Maryam Dehghani  Heidar Ali Talebi 《国际强度与非线性控制杂志
》2019,29(15):5164-5177

This paper deals with the problem of designing a robust static output feedback controller for polytopic systems. The current research that tackled this problem is mainly based on LMI method, which is conservative by nature. In this paper, a novel approach is proposed, which considers the design space of the controller parameters and iteratively partitions the space to small simplexes. Then, by assessing the stability in each simplex, the solution space for design parameters is directly determined. It has been theoretically proved that, if there exists a feasible solution in the design space, the algorithm can find it. To validate the result of the proposed approach, comparative simulation examples are given to illustrate the performance of the design methodology as compared to those of previous approaches.  相似文献   

    

Sana Pirmardvand Chegini  Jaleh Varshosaz  Hamid Mirmohammad Sadeghi  Alireza Dehghani  Mohsen Minayian 《IET nanobiotechnology / IET》2019,13(9):974

Poly(glycerol sebacate) (PGS) is a new biodegradable polymer with good biocompatibility used in many fields of biomedicine and drug delivery. Sunitinib‐loaded PGS/gelatine nanoparticles were prepared by the de‐solvation method for retinal delivery and treatment of diabetic retinopathy. The nanoparticles were characterised by Fourier‐transform infrared and differential scanning calorimetry. The effects of different formulation variables including drug‐to‐carrier ratio, gelatine‐to‐PGS ratio, and glycerine‐to‐sebacate ratio were assessed on the encapsulation efficiency (EE%), particle size, release efficiency (RE), and zeta potential of the nanoparticles. The in vitro cytotoxicity of PGS/gelatine nanoparticles was studied on L929 cells. Draize test on rabbit eyes was also done to investigate the possible allergic reactions caused by the polymer. Glycerine/sebacic acid was the most effective parameter on the EE and RE. Gelatine‐to‐PGS ratio had the most considerable effect on the particle size while the RE was more affected by the glycerine/sebacic acid ratio. The optimised formulation (S₁ G_0.7 D_21.2) exhibited a particle size of 282 nm, 34.6% EE, zeta potential of −8.9 mV, and RE% of about 27.3% for drug over 228 h. The 3‐(4,5‐dimethylthuazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay indicated PGS/gelatine nanoparticles were not cytotoxic and sunitinib‐loaded nanoparticles were not toxic at concentrations <36 nM.Inspec keywords: polymers, differential scanning calorimetry, toxicology, drug delivery systems, solvation, eye, encapsulation, particle size, drugs, biodegradable materials, nanofabrication, nanomedicine, nanoparticles, gelatin, Fourier transform infrared spectraOther keywords: gelatine‐to‐PGS ratio, glycerine‐to‐sebacate ratio, particle size, zeta potential, sunitinib‐loaded nanoparticles, biodegradable polymer, retinal delivery, differential scanning calorimetry, drug‐to‐carrier ratio, allergic reactions, physicochemistry, cytotoxicity, poly(glycerol sebacate) nanoparticles, sunitinib ocular delivery, drug delivery, sunitinib‐loaded PGS‐gelatine nanoparticles, Fourier‐transform, in vitro cytotoxicity, biocompatibility, Draize test, rabbit eyes, 3‐(4,5‐dimethylthuazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay  相似文献