Delivery of vinblastine-containing niosomes results in potent in vitro/in vivo cytotoxicity on tumor cells

Vinblastine (VB), as a chemotherapeutic agent, is widely used in treatment of different types of cancer. However, its clinical application is limited due to its low water solubility, side effects, and multidrug resistance. The aim of this study was to increase the therapeutic efficacy of VB using drug delivery systems. For this purpose, a PEGylated niosomal formulation of vinblastine (Pn-VB) was prepared by thin film hydration method and physicochemically characterized. Drug release pattern was performed by dialysis diffusion method. The cytotoxicity of Pn-VB was investigated against murine lung cancer TC-1 cells using MTT assay and its tumor inhibitory effect was evaluated in lung tumor-bearing C57BL/6 mice. Mean particle size, zeta potential, entrapment, and loading efficiency of niosomes were obtained to be about 234.3?±?11.4?nm, -34.6?±?4.2?mV, 99.92?±?1.6%, and 2.673?±?0.30%, respectively. While, the mean particle size and zeta potential for non-PEGylated niosomes were obtained about 212.4?nm and -31.4?mV, respectively. The in vitro release pattern of drug from niosomes showed a sustained release behavior. Pn-VB indicated a significant increase in toxicity against TC-l cells as compared to free VB. In animal model, Pn-VB exhibited stronger tumor inhibitory effect and longer life time in comparison to free VB. In conclusion, Pn-VB showed appropriate stability, high-entrapment efficacy, lower releasing rate, and stronger cytotoxic activity against lung cancer TC-1 cells as compared to free drug. Thus, the Pn-VB could be a promising formulation for delivery of vinblastine to tumor cells with enhanced drug bioavailability and therapeutic efficacy.     

Effect of processing method on migration of antioxidant from HDPE packaging into a fatty food simulant in terms of crystallinity

Migration of additives from plastic packaging into food products is generally considered to be affected by polymer crystallinity. In the present work, migration of Irganox 1010 from high density polyethylene into a fatty food simulant (ethanol 95%) was studied for samples prepared with different percent crystallinities. For this purpose, 2 different processing techniques, injection and compression molding, were used, and the preparation conditions were changed to obtain high density polyethylene samples with crystallinities in the range of 50 to 70%. Migration analysis was carried out at 121°C for 2 hours, and then at 40°C for 238 hours using high performance liquid chromatography. In general, the injection molded specimens had lower crystallinity and higher overall migration than the compression molded ones. A similar trend for both injection and compression molded samples was observed indicating that the overall migration was a function of crystallinity degree. However, the specific migration rates of Irganox 1010 especially before 50 hours were found to be different for the 2 processing methods because of dissimilar morphologies. Theoretical modeling based on Fickian diffusion was applied to give more insights into the involved processes during specific migration. The interaction of the food simulant with the polymer was taken into account considering the food sorption into the polymer. By fitting the model on experimental data, it was possible to obtain the model parameters such as partition coefficients (K) and the swelling constant (B) as a function of sample crystallinity.     

Thermodynamic entropy generation in the course of the fatigue crack initiation

Evolution of the thermodynamic entropy generation during fatigue crack initiation life of notched specimens is studied. A set of experimental results of AA7075‐T651 is examined to determine applicability of the thermodynamic entropy generation as an index of fatigue crack initiation. Entropy accumulation is calculated from hysteresis energy and temperature rise. An increasing trend of entropy accumulation with the number of cycle to failure is observed on macroscale measurements. Results also determine that the entropy generations from the samples under the same operating conditions are similar as the crack grows. Scanning electron microscope analysis is performed on the fractured surfaces to observe the fatigue striations, and persistent slip bands are observed employing an optical microscope. A discussion is presented regarding the length scales on which crack initiation occurs and entropy calculation is made.     

Multi-objective scheduling of dynamic job shop using variable neighborhood search

Dynamic job shop scheduling that considers random job arrivals and machine breakdowns is studied in this paper. Considering an event driven policy rescheduling, is triggered in response to dynamic events by variable neighborhood search (VNS). A trained artificial neural network (ANN) updates parameters of VNS at any rescheduling point. Also, a multi-objective performance measure is applied as objective function that consists of makespan and tardiness. The proposed method is compared with some common dispatching rules that have widely used in the literature for dynamic job shop scheduling problem. Results illustrate the high effectiveness and efficiency of the proposed method in a variety of shop floor conditions.     

Integral Backstepping Control of an Unconventional Dual-Fan Unmanned Aerial Vehicle

In this paper, a dynamic model of vertical take-off and landing (VTOL) aerial vehicles, having lateral and longitudinal rotor tilting mechanism, is first developed using a Newton–Euler formulation. Then an integral backstepping (IB) control technique is proposed to improve the pitch, yaw, and roll stability of the vehicle. Such control mechanisms enables the UAV to perform complex tasks that no other Unmanned Aerial Vehicles (UAVs) can execute such as hover pitched. This control tactic allows the vehicle under investigation, eVader, to use the full potential of its flying characteristics enabled by the novel dual-axis oblique active tilting (OAT) mechanism, which enables it to maneuver inside obstructed environments. The potential of the eVader as a small UAV and its model are verified and then used to for autonomous take-off and landing as well as stabilizing the vehicle’s attitude. Finally, diverse simulation scenarios on attitude and position control, stabilization and autonomous take off and landing are presented.     

Optimal 3D trajectory generation in delivering missions under urban constraints for a flying robot

Interest in applying flying robots especially quadcopters for civil applications, in particular for delivering purposes, has dramatically grown in the recent years. In fact, since quadcopters are capable of vertical takeoff and landing, they can be widely employed for nearly any aerial task where a human presence is hazardous or response time is critical. In this regard, quadcopters come to be very beneficial in delivering packages; accordingly, generating an optimal flight trajectory plays a preponderant role for meeting this vision. This paper is concerned with generation of a time-optimal 3D path for a quadcopter under municipal restrictions in delivering tasks. To this end, the flying robot’s dynamics is first modeled through Newton–Euler method. Subsequently, the problem is formulated as a time-optimal control problem such that the urban constraints, which are safe-margins of high-rise buildings located throughout the course, are first modeled and then imposed to the trajectory optimization problem as inequality constraints. After discretizing the trajectory by means of Hermit–Simpson method, the optimal control problem is transformed into a nonlinear programming problem and finally is solved by the direct collocation technique. Extensive simulations demonstrate the efficacy of the proposed method and correspondingly verify the effectiveness of the suggested method in generation of optimum 3D routes while all constraints and mission requirements are satisfied.     

Numerical simulation of residual stress induced by roll-peening

There are various techniques to improve the components resistance against oscillating loads or fatigue. One of the most efficient techniques is to induce a compressive residual stress layer on the surface of the component. This can be accomplished by different methods such as surface coating, shot-peening, heat treatment, laser peening and roll-peening. The latter is widely used for surface modification of flat and cylindrical industrial components such as crankshaft and etc. The distribution, layer thickness, and the maximum of residual stress induced by roll-peening can be influenced by parameters of rolling such as work piece material, radius of roller curved boundary, roller angular velocity, roller transverse speed, and rolling depth. In this work the effect of these parameters are studied by numerical simulations. The material used in this work is AISI 4340. The roller is a solid disk with a curved boundary. The results indicate that: (i) the surface residual stress increases with the increase of rolling depth up to a specific value thereafter begins to decline; (ii) the effect of roller curvature radius on surface residual stress shows exactly the same trend as the rolling depth does; (iii) for a strain rate hardened material which is the case for the material used in this work, the angular velocity of the roller gives rise to the increase of the surface residual stress and finally, (iv) the increase of the transverse speed of the roller brings about the reduction in the residual surface, as expected.     

Nickel electrodeposition on copper substrate for cyclotron production of <Superscript>64</Superscript>Cu

Natural nickel electrodeposition on a copper substrate with a gold layer was studied with the aim of production of ⁶⁴Cu radionuclide. The electrodeposition experiments were carried out in acid plating baths. The operating parameters such as pH, temperature, and current density were optimized. The current efficiency was measured at different current densities. The optimum conditions of the nickel electrodeposition are as follows: 5.7 g 1⁻¹ nickel, pH 3–4, dc current density 85.54 mA cm⁻², and 55°C, with 97% current efficiency. SEM photomicrographs demonstrated fine-grained structure of the deposit obtained from the optimum bath. A 46-μm high-quality layer was deposited on a gold layer of the copper substrate.     

Poly(ε-caprolactone) electrospun nanofibers containing curcumin nanocontainers: enhanced solubility,dissolution and physical stability of curcumin via formation of inclusion complex with cyclodextrins

Supramolecular nanocontainers of cyclodextrins (α- and β-CD)/curcumin (CUR) were prepared by inclusion complex (IC) forming between CDs and guest molecule at two conditions. Formation of the inclusion complex between CDs and CUR at various conditions in solid phase was characterized by various methods. Solubility and in vitro dissolution of obtaining CUR nanocapsules were investigated and results showed that encapsulation of CUR, improved CUR bioavailability with a controllable release. Electrospun nanofibers of poly-ε-caprolactone (PCL) containing CUR/CDs inclusion complex of various conditions have been fabricated using a conventional electrospinning process and indicated that these nanofibers are bead-free.