3,213 research outputs found

    A new approach for solving nonlinear Thomas-Fermi equation based on fractional order of rational Bessel functions

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    In this paper, the fractional order of rational Bessel functions collocation method (FRBC) to solve Thomas-Fermi equation which is defined in the semi-infinite domain and has singularity at x=0x = 0 and its boundary condition occurs at infinity, have been introduced. We solve the problem on semi-infinite domain without any domain truncation or transformation of the domain of the problem to a finite domain. This approach at first, obtains a sequence of linear differential equations by using the quasilinearization method (QLM), then at each iteration solves it by FRBC method. To illustrate the reliability of this work, we compare the numerical results of the present method with some well-known results in other to show that the new method is accurate, efficient and applicable

    Preliminary assessment of various additives on the specific reactivity of anti- rHBsAg monoclonal antibodies

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    Background: Antibodies have a wide application in diagnosis and treatment. In order to maintain optimal stability of various functional parts of antibodies such as antigen binding sites, several approaches have been suggested. Using additives such as polysaccharides and polyols is one of the main methods in protecting antibodies against aggregation or degradation in the formulation. The aim of this study was to evaluate the protective effect of various additives on the specific reactivity of monoclonal antibodies (mAbs) against recombinant HBsAg (rHBsAg) epitopes. Methods: To estimate the protective effect of different additives on the stability of antibody against conformational epitopes (S3 antibody) and linear epitopes (S7 and S11 antibodies) of rHBsAg, heat shock at 37°C was performed in liquid and solid phases. Environmental factors were considered to be constant. The specific reactivity of antibodies was evaluated using ELISA method. The data were analyzed using SPSS software by Mann-Whitney nonparametric test with the confidence interval of 95%. Results: Our results showed that 0.25 M sucrose, 0.04 M trehalose and 0.5% BSA had the most protective effect on maintaining the reactivity of mAbs (S3) against conformational epitopes of rHBsAg. Results obtained from S7 and S11 mAbs against linear characteristics showed minor differences. The most efficient protective additives were 0.04 M trehalose and 1 M sucrose. Conclusion: Nowadays, application of appropriate additives is important for increasing the stability of antibodies. It was concluded that sucrose, trehalose and BSA have considerable effects on the specific reactivity of anti rHBsAg mAbs during long storage. © 2015, Avicenna Journal of Medical Biotechnology. All rights reserved

    Water disinfection using photocatalytic process with titanium dioxide nanoparticles

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    Background and purpose: Disinfection is one of the most important stages in water treatment. So far, various chemical disinfection methods such as chlorination have been widely used. However, these methods have serious disadvantages, like producing DBPs. The purpose of this research was to study the efficacy of nTiO2 photocatalyst process on removing E.Coli as a water microbial pollution index and effects of some parameters on its efficiency. Materials and methods: Water was artificially contaminated with E.Coli. Culture method and counting were performed according to standard methods for water and wastewater and was reported as CFU/ml. The size of nTiO2 was 20 nm that was used in the presence or absence of UV for disinfection. The Kolmogorov-Smirnov Test was used to check the normality of the data. The ANOVA and T-Test were used for analyzing the data. Results: The results indicated that the inactivation of Escherichia coli increased with increase of nTiO2 catalyst dose and contact time. However, the efficiency decreased when the number of colonies increased. Minimum, average and maximum percentage removal of nTiO2+UV process were 75.1, 88.9±12.7, and 100%, respectively, in 40 min contact time and 0.8 g/L catalyst dose. Conclusion: The bacteria mortality rate in the presence of UV alone was more than that of the nTiO2 alone process. However, the efficiency of the photocatalytic process (UV+nTiO2) was more than that of the UV alone or nTiO2 alone. © 2015, Mazandaran University of Medical Sciences. All rights reserved

    The effects of diclofenac suppository and intravenous acetaminophen and their combination on the severity of postoperative pain in patients undergoing spinal anaesthesia during cesarean section

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    Introduction: The main tasks of postoperative care are postoperative pain and complications control which play an important role in accelerating the recovery of patient’s general condition. Aim: This study was performed in order to compare the effects of diclofenac suppository, intravenous acetaminophen and their combination on the severity of postoperative pain in patients undergoing spinal anaesthesia for cesarean section in Sayyad Shirazi teaching Hospital, Gorgon, Iran. Materials and Methods: This was a double-blind clinical trial on 90 patients undergoing cesarean section. The patients were randomly divided into three groups, group A: 100 mg diclofenac suppository, group B: 1000 mg intravenous acetaminophen, group C: 100 mg diclofenac suppository and 500 mg intravenous acetaminophen. The same spinal anaesthesia circumstances were applied for all the participants. At the end of surgery, pain severity was assessed according to VAS scale at different times. Data were then analysed by SPSS 18 statistical software. Results: The mean age of participants was (28.27±6.07). There was significant difference between the mean pain scores of the three groups before the intervention (p=0.018), which was considered as co-variate. This difference was more notable between the combination of acetaminophen - diclofenac group and diclofenac alone. After the intervention, significant difference was observed in mean pain severity between acetaminophen group and the combination group and also between diclofenac and the combination group. During the study, the least mean pain severity was found in the combination group and the highest was observed in the diclofenac group. Conclusion: Results of this study indicates a significant effect of concomitant use of intravenous acetaminophen and diclofenac suppository on pain severity reduction and reducing the need for repeated doses of narcotics and prolonging the postoperative analgesia. © 2016, Journal of Clinical and Diagnostic Research. All rights reserved

    Design Considerations of Structural Parameters in Resonant Tunneling Diode by None-Equilibrium Green Function Method

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    This paper presents the effects of structural parameters like Quantum well width, barrier width, spacer width, contact width and contact doping, on performance of Resonant Tunneling Diode using full quantum simulation. The simulation is based on a self-consistent solution of the Poisson equation and Schrodinger equation with open boundary conditions, within the non-equilibrium Green’s function formalism. The effects of varying the structural parameters is investigated in terms of the output current, peak current, valley current, peak to valley current ratio and the voltage associated with the peak current. Simulation results illustrate that the device performance can be improved by proper selection of the structural parameters

    Synthesis of M–Nd doped Fe3O4 nanoparticles (M = Co, Ce, Cr, Ni) with tunable magnetic properties

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    Magnetic nanoparticles were prepared by the aqueous co-precipitation method. The magnetic nanoparticles obtained were characterized systematically through the use of an X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and a vibrating  sampling  magnetometer (VSM). The results revealed that the magnetic nanoparticles were spherical shaped with inverse spinel structure. The size of Fe3O4 and Nd-Co doped Fe3O4 magnetic nanoparticles were approximately 15 nm. Magnetic measurement revealed that the nanoparticles were super paramagnetic at room temperature. It was found that the magnetic response of the Fe3O4 increased when it was doped with Nd3+ and Co2+. However, the magnetic response of the Fe3O4 decreased when it was doped with Nd3+ or Ce3+ or Cr3+or Ni2+. KEYWORDS: Fe3O4, Magnetic nanoparticles, Superparamagnetic, Magnetite, Fe3O4 doped Bull. Chem. Soc. Ethiop. 2013, 27(1), 49-56.DOI: http://dx.doi.org/10.4314/bcse.v27i1.

    Design Considerations of Structural Parameters in Resonant Tunneling Diode by None-Equilibrium Green Function Method

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    This paper presents the effects of structural parameters like Quantum well width, barrier width, spacer width, contact width and contact doping, on performance of Resonant Tunneling Diode using full quantum simulation. The simulation is based on a self-consistent solution of the Poisson equation and Schrodinger equation with open boundary conditions, within the non-equilibrium Green’s function formalism. The effects of varying the structural parameters is investigated in terms of the output current, peak current, valley current, peak to valley current ratio and the voltage associated with the peak current. Simulation results illustrate that the device performance can be improved by proper selection of the structural parameters

    Linear and Nonlinear Frequency-Division Multiplexing

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    Two signal multiplexing schemes for optical fiber communication are considered: Wavelength-division multiplexing (WDM) and nonlinear frequency-division multiplexing (NFDM), based on the nonlinear Fourier transform. Achievable information rates (AIRs) of NFDM and WDM are compared in a network scenario with an ideal lossless model of the optical fiber in the defocusing regime. It is shown that the NFDM AIR is greater than the WDM AIR subject to a bandwidth and average power constraint, in a representative system with one symbol per user. The improvement results from nonlinear signal multiplexing
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