Damage of the retinal pigmented epithelial cells causes various diseases such as age-related macular degeneration in retinal tissue. Nowadays, scientists are attempting to replace lost retinal cells with healthy and efficient cells that provide better conditions for recovering and preventing blindness. In this study, gelatin/chitosan nanofibrous scaffolds with mean diameters of 180?nm were fabricated for subretinal space through electrospinning. Thickness and morphology of the gelatin–chitosan scaffolds were analyzed by scanning electron microscopy (SEM). The results showed that the high rate of degradation, i.e., 90% damage was obtained after 1 month. The cell viability of gelatin/chitosan nanofibers were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The SEM results of cultured RPE on gelatin/chitosan scaffolds showed the appropriate adhesion of cells on the substrate. The results of the identity of RPE cells cultured on the scaffolds indicated that a large number of cells strongly expressed RPE65 and cytokeratin 8/18. 相似文献
Attention deficit hyperactivity disorder (ADHD) is a common behavioural disorder that may be found in 5%–8% of the children. Early diagnosis of ADHD is crucial for treating the disease and reducing its harmful effects on education, employment, relationships, and life quality. On the other hand, non‐linear analysis methods are widely applied in processing the electroencephalogram (EEG) signals. It has been proved that the brain neuronal activity and its related EEG signals have chaotic behaviour. Hence, chaotic indices can be employed to classify the EEG signals. In this study, a new approach is proposed based on the combination of some non‐linear features to distinguish ADHD from normal children. Lyapunov exponent, fractal dimension, correlation dimension and sample, fuzzy and approximate entropies are the non‐linear extracted features. For computing, the chaotic time series of obtained EEG in the brain frontal lobe (FP1, FP2, F3, F4, and Fz) need to be analysed. Experiments on a set of EEG signal obtained from 50 ADHD and 26 normal cases yielded a sensitivity, specificity, and accuracy of 98, 92.31, and 96.05%, respectively. The obtained accuracy provides a significant improvement in comparison to the other similar studies in identifying and classifying children with ADHD.Inspec keywords: feature extraction, time series, fractals, electroencephalography, medical disorders, neurophysiology, medical signal processing, entropy, signal classification, Lyapunov methodsOther keywords: nonlinear extracted features, chaotic time series, identifying classifying children, attention deficit hyperactivity disorder, nonlinear analysis methods, electroencephalogram signals, brain neuronal activity, chaotic behaviour, chaotic indices, EEG signals, nonlinear features, approximate entropies, common behavioural disorder, early diagnosis, life quality, ADHD相似文献
This paper reports the production of a novel magnetic nanocomposite based on multi-walled carbon nanotubes (MWCNTs) decorated with magnetic core–shell Fe3O4@SiO2 nanoparticles which were used to fabricate a modified carbon paste electrode (Fe3O4@SiO2/MWCNT-CPE). The Fe3O4@SiO2/MWCNT-CPE was investigated for the simultaneous determination of sunset yellow (SY) and tartrazine (TT) in 0.1 mol/L phosphate buffer solution (pH 6.0) using square wave voltammetry (SWV). The synthesized nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. The proposed electrode exhibits linear ranges of 0.5–100 μmol/L SY and TT with detection limits of 0.05 and 0.04 μmol/L for SY and TT, respectively. The novel proposed voltammetric method was successfully applied in the simultaneous determination of SY and TT in food products, with results similar to those obtained using a HPLC method at 95 % confidence level.
Graphical Abstract A magnetic nanocomposite based on MWCNTs decorated with core–shell Fe3O4@SiO2 was prepared and showed good ability to distinguish the response of SY and TT
Due to their sensitivity and temporal response, optical microresonators are used extensively in the biosensor arena, particularly in the development of label-free diagnostics and measurement of protein kinetics. In the present letter, we investigate using microcavities to probe molecules within biomimetic membranes. Specifically, a method for self-assembling lipid bilayers on spherical microresonators is developed and the bilayer-nature is verified. Subsequently, the microcavity is used to excite a Cy5-conjugated lipid located within the bilayer while the optical performance of the microcavity is characterized. The emission wavelength of the dye and the optical behavior of the microcavity agree with theoretical predictions. 相似文献
In this paper, we consider a three-stage assembly flowshop scheduling problem with bi-objectives, namely the mean flow time and maximum tardiness. This problem can be considered as a production system model consisting of three stages: (1) different production operations are done in parallel, concurrently and independently, (2) the manufactured parts are collected and transferred to the next stage, and (3) these parts are assembled into final products. In this paper, sequence-dependent setup times and transfer times are also considered as two important presumptions in order to make the problem more realistic. We present a novel mathematical model for a production system with a new lower bound for the given problem. Obtaining an optimal solution for this type of complex, large-sized problem in reasonable computational time by using traditional approaches and optimization tools is extremely difficult. Thus, we propose two meta-heuristics, namely simulated annealing and tabu search, to solve a number of test problems generated at random. Finally, the computational results are illustrated and compared in order to show the efficiency of the foregoing meta-heuristics. 相似文献
Objective: The aim of this study was the preparation of a self nano-emulsifying drug delivery system (SNEDDS) for oral delivery of heparin.Significance: Preparation of hydrophobic complexes between heparin as the hydrophilic macromolecule and cationic polymer of β-cyclodextrin (CPβCD) was considered for preparation of orally administered SNEDDS in which the drug incorporated in internal oil phase of O/W nano-droplets.Methods: Hydrophobic complexes of heparin-CPβCD were prepared by electrostatic interaction. The lipophilic feature of complexes was characterized by determining their partition co-efficients. SNEDDS prototypes were prepared by mixing liquid paraffin, Tween 80, propylene glycol and ethanol, diluted 1:100 in an aqueous medium. Central composite response surface methodology was applied for statistical optimization. Independent variables were the amount of liquid paraffin and the amount of Tween 80, while responses were size and poly dispersity index (PdI). Optimized SNEDDS were studied morphologically using transmission electron microscopy (TEM). In vitro release of heparin was studied in the simulated gastric and simulated intestinal media.Results: The data revealed that in molar ratio 1:3 (heparin:CPβCD), the n-octanol recovery was maximized and reached 67.6?±?11.86%. Size, PdI, zeta potential, EE% in gastric medium and EE% in intestinal medium for optimized nano-droplets were reported as 307?±?30.51?nm, 0.236?±?0.02,?+2.1?±?0.66?mV, 90.2?±?0.04 and 96.1?±?0.73%, respectively. Microscopic images revealed spherical nano-droplets. The obtained data revealed no burst release of heparin from nano-droplets.Conclusions: The obtained results indicate that SNEDDS could be regarded as a good candidate for oral delivery of heparin as the hydrophilic macromolecule. 相似文献
The main aim of this research was to compare the effects of hydrothermal treatment on rice flour and its related rice starch. The treatment was performed at 120°C for 3 and 5 h. Scanning electron microscopy results showed that the proteins of hydrothermaled rice flour were denatured and formed clusters and the granules of hydrothermaled rice starch became aggregated and had an irregular surface. The treatment reduced water solubility and water absorption and decreased peak viscosity while increased pasting temperature. It increased the final visosity of modified rice flour while reduced the final viscosity of modified rice starch. Following hydrothermal treatment, the hardness and elasticity of the gels increased. The cohesiveness of rice flour gels decreased while that of the rice starch gels remained unchanged. This study showed how the hydrothermal treatment can have different effects on rice flour and its related rice starch. The effects of hydrothermal treatment on rice flour were stronger than rice starch. Increasing the treatment time from 3 to 5 h was more effective on rice starch. 相似文献
Tensile strength, modulus of rupture, and impact resistance were found for different layer orientations of ABS rapid prototype solid models. The samples were fabricated by a Stratasys rapid prototyping machine in five different layer orientations. The 0° orientation where layers were deposited along the length of the samples displayed superior strength and impact resistance over all the other orientations. The anisotropic properties were probably caused by weak interlayer bonding and interlayer porosity. 相似文献