In recent years, many image encryption approaches have been proposed on the basis of chaotic maps. The various types of chaotic maps such as one-dimensional and multi-dimensional have been used to ...generate the secret keys. Chaotic maps require some parameters and value assignment to these parameters is very crucial. Because, poor value assignments may make the chaotic map un-chaotic. Therefore, hyper-parameter tuning of chaotic maps is required. Recently, meta-heuristic based image encryption approaches have been designed by researchers to resolve this issue. However, the majority of the techniques suffer from poor computational speed and stuck in local optima problems. Therefore, in this study, a strength Pareto evolutionary algorithm-II based meta-heuristic approach is proposed to tune the hyper-parameters of the four-dimensional chaotic map. The proposed approach is also implemented in a parallel fashion to enhance the computational speed. The effectiveness of the proposed approach is evaluated through extensive experiments. Comparative analyses show that the proposed approach outperforms the competitive approaches in terms of entropy, NPCR, UACI, and PSNR by $0.9834$0.9834, $ 1.0728$1.0728, $ 0.9134$0.9134, and $ 0.8971\%$0.8971%, respectively.
Due to the relatively poor cell-material interaction of alginate hydrogel, alginate-gelatin crosslinked (ADA-GEL) hydrogel was synthesized through covalent crosslinking of alginate di-aldehyde (ADA) ...with gelatin that supported cell attachment, spreading and proliferation. This study highlights the evaluation of the physico-chemical properties of synthesized ADA-GEL hydrogels of different compositions compared to alginate in the form of films. Moreover, in vitro cell-material interaction on ADA-GEL hydrogels of different compositions compared to alginate was investigated by using normal human dermal fibroblasts. Viability, attachment, spreading and proliferation of fibroblasts were significantly increased on ADA-GEL hydrogels compared to alginate. Moreover, in vitro cytocompatibility of ADA-GEL hydrogels was found to be increased with increasing gelatin content. These findings indicate that ADA-GEL hydrogel is a promising material for the biomedical applications in tissue-engineering and regeneration.
Abstract
In this paper, an SIR epidemic model is investigated and analysed by incorporating an incubation time delay in identification of infected population. The state variables considered ...are:susceptible, infected and recovered host individuals. The non-zero interior equilibrium is calculated. By applying the time delay as a bifurcation parameter, the local stability of the endemic equilibrium is studied and the condition which is absolutely stable or conditionally stable is established. Furthermore, a Hopf bifurcation occurs under certain conditions. Numerical simulations are carried out using MATLAB. to illustrate the main results.
The synthesis of Ag
x
Zn
1−
x
O is completed by chemical precipitation method and then X-ray diffraction is used to detail out the structural parameters (like crystallite size and phase ...identification). A hexagonal wurtzite structure is confirmed after analyzing the XRD results, which shows a single phase. The crystallite size and microstrain are evaluated by different models of W–H and SSP method; their values show an increasing pattern with the rise in the doping element. While band gap value decreases with rise in the concentration ratio of silver doping, in contrast to this Urbach energy (eV) is opposite to the band gap value that is evaluated by the absorption spectra of UV–Vis. This is mostly used in the optoelectronic application. The FTIR (Fourier transmission infrared spectroscopy) results are detailed about functional bonds; Ag bonds appear in its representation within ZnO bond. FESEM confirmed that the aggregation formation increases with increases in silver doping concentrations.
The photovoltaic sector needs a high-throughput slicing method that produces minimal waste to meet rising demand. Wire electric discharge machining (WEDM) has emerged as an alternative slicing method ...in recent research efforts. Polycrystalline silicon is sliced using the WEDM process with a zinc-coated electrode of Ø0.25 mm in diameter. Experiments were planned and conducted according to Box Behnken’s design of experiments. As inputs, seven different process parameters were used: pulse on time (PONT), pulse off time (POFFT), peak current (PC), spark gap voltage (SGV), wire feed (WF), wire tension (WT), and water pressure (WP). Response parameters measured were cutting speed (CS), surface roughness (SR), and kerf width (KW). Various process parameters have also been analyzed with ANOVA methods for predictive modeling. Based on experimental data, this study determines the appropriate optimal solutions
desirability functions. During the WEDM process, the PONT, POFFT, PC, and SGV significantly influence the discharge energy on the sliced surface. As a result of this study, CS of 0.78 mm
/min, SR of 2.87 μm, and KW of 0.70 mm were observed at the optimal settings of PONT of 119 μs, POFFT of 42 μs, PC of 38A, SGV of 36V, WF of 3 mm/min, WT of 2 kg and WP of 6 kg/cm
. Surface morphology was determined using scanning electron microscope and Energy dispersive X-ray to investigate the surface characteristics.
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•PCL and silk fibroin (SF) blended fibers are electrospun using benign solvents.•Growth of primary endothelial cells and fibroblasts is enhanced on PCL/SF fibers.•Radial magnetic cell ...seeding is tested to colonize 3D tubular PCL/SF scaffolds.•Lumen endothelialization is improved by the presence of fibroblasts.
The availability of cell growth-supporting materials for regenerative medicine is limited. Here, we aimed to improve the attachment and growth of endothelial cells (HUVECs) and fibroblasts on electrospun poly(ε-caprolactone) (PCL) mats with different fiber diameters and on newly-established PCL and silk fibroin (PCL/SF) blended fibers obtained by using benign solvents (mixture of acetic acid and formic acid) for electrospinning.
PCL mats were produced in two different average fiber diameters, namely micro and nano range. The electrospinning method was optimized to produce PCL/SF blended fibers. Morphology (F-actin), viability (calcein) and metabolic activity (WST-8 assay) of HUVECs and fibroblasts cultured in 2D on the mats of different fiber size and composition were compared. Subsequently, cylindrical PCL/SF scaffolds were produced and colonized with cells using 3D radial magnetic cell seeding.
Both PCL and PCL/SF nanofibers provided better support for initial cell adhesion (day 1) compared with PCL microfibers. At day 7, the highest metabolic activity in HUVECs and fibroblasts was observed on PCL/SF mats. Microscopic studies confirmed that on day 7, the best support for cell growth was observed on PCL/SF. Tubular PCL/SF scaffolds were successfully colonized using magnetic nanoparticles and 3D radial magnetic cell seeding.
Taken together, the fibers obtained by blending SF with PCL combine the mechanical benefits of PCL with improved biological functionality of SF. Electrospun PCL/SF nanofibers represent a promising material to produce both flat and 3D structures with potential for enhanced cell attachment and tissue regeneration.
Rupture of the distal biceps tendon is a relatively uncommon injury. Different methods have been described for its surgical repair. According to published reports, current surgical techniques result ...in decreased strength and endurance of upper extremity functions requiring supination and flexion. In our anatomic study of 74 cadaveric elbows, we observed that the distal biceps tendon spirals in a predictable manner and has a complex fiber arrangement. Successful surgical repair of a ruptured distal biceps tendon should be predicated on an understanding of the tendon anatomy, but current surgical techniques do not take into account the salient anatomic features of the distal biceps tendon. To our knowledge, there is no description in the surgical literature of the fiber arrangement of the distal biceps tendon. We provide a basis for developing an anatomically accurate protocol for repairing a distal biceps tendon rupture.
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