Enhancement of in vitro antitumour activity of epirubicin in HER2+ breast cancer cells using immunoliposome formulation

Epirubicin (EPI) is one of the potent breast cancer (BC) chemotherapeutic agents, but its adverse effects limit its efficacy. Herein, EPI was selected to be loaded in liposomal carrier, which has been targeted by a monoclonal antibody, Herceptin. The preparation process of liposomes was a modified ethanol injection method followed by Herceptin conjugation. The in vitro cell toxicity and cellular uptake of optimum formulation against HER2+ and HER2− cancer cell lines were evaluated. The results showed that the drug loading (DL%) and encapsulation efficiency (EE%) of liposome preparation method yielded 30.62% ± 0.49% and 62.39% ± 8.75%, respectively. The average size of naked liposomes (EPI‐Lipo) and immunoliposomes (EPI‐Lipo‐mAb) was 234 ± 9.86 and 257.26 ± 6.25 nm, with a relatively monodisperse distribution, which was confirmed by SEM micrographs. The release kinetic followed Higuchi model for both naked and immunoliposomes. In vitro cytotoxicity study on three different BC cell lines including BT‐20, MDA‐MB‐453 and MCF‐7 demonstrated higher toxicity of EPI in the Herceptin conjugated form (EPI‐Lipo‐mAb) in comparison with the free EPI and EPI‐Lipo in HER2 overexpressing cell line. In addition, the cellular uptake study showed a higher uptake of immunoliposomes by MCF‐7 cells in comparison with naked liposomes. In conclusion, these data show that the targeted delivery of EPI to breast cancer cells can be achieved by EPI‐Lipo‐mAb in vitro, and this strategy could be used for breast cancer therapy with further studies.     

Modelling the effects of machine breakdowns in the generalized cell formation problem

Machines are key elements in manufacturing systems and their breakdowns can dramatically affect system performance measures. This paper proposes a new multi-objective pure integer linear programming approach for the cell formation problem with alternative process routings and machine reliability consideration. The model minimizes total cost and maximizes system reliability simultaneously. Traditional reliability evaluation approaches attempt to model the reliability of the manufacturing system as a function of its elements. These approaches have some negative aspects; therefore, instead of modeling the system reliability as an explicit objective function, we use an approach to model the effects of the machine unreliability in terms of cost and time-based effects. Using the ?-constraint method as an optimization tool for multi-objective programming, a numerical example is solved to demonstrate the capability of the proposed model in evaluating various effects of the reliability consideration.     

Stepping toward standard methods of small-signal parameterextraction for HBTs

An improved HBT small-signal parameter extraction procedure is presented in which all the equivalent circuit elements are extracted analytically without reference to numerical optimization. Approximations required for simplified formulae used in the extraction routine are revised, and it is shown that the present method has a wide range of applicability, which makes it appropriate for GaAs and InP-based single and double HBTs. Additionally, a new method is developed to extract the total delay time of HBTs at low frequencies, without the need to measure h₂₁ at very high frequencies and/or extrapolate it with -20 dB/dec roll-off. The existing methods of finding the forward transit time are also modified to improve the accuracy of this parameter and its components. The present technique of parameter extraction and delay time analysis is applied to an InGaP/GaAs DHBT and it is shown that: (1) variations of all the extracted parameters are physically justifiable; (2) the agreement between the measured and simulated S- and Z-parameters in the entire range of frequency is excellent; and (3) an optimization step following the analytical extraction procedure is not necessary. Therefore, we believe that the present technique can be used as a standard extraction routine applicable to various types of HBTs     

Sono-Fenton regeneration of granular activated carbon saturated with Rhodamine B: Optimization using response surface methodology

This study investigated the combination of chemical and ultrasonic regeneration (Sono-Fenton), used for regenerating granular activated carbon (GAC) saturated with Rhodamine B (RB). This process was modeled and optimized using response surface methodology (RSM) based on central composite design (CCD). Effective parameters on regeneration efficiency such as pH, concentration of hydrogen peroxide (H₂O₂), and time of ultrasonic irradiation were optimized and modeled using the reduced quadratic method. The fitness of the model was checked by the determination coefficient (R²?=?0.9978). At optimum condition, the effective parameters of pH?=?3.84, concentration of H₂O₂?=?38.28 (mM), and time of ultrasonic irradiation?=?23.11(min), maximum regeneration efficiency (87.88%) was achieved, the results of which were obtained after four-time sequential adsorption–regeneration cycles were acceptable. Desorption and degradation of RB were conducted through the generation of active species, including hydroxyl radicals and high-energy ultrasound. The regeneration efficiency was increased using this combination method. In conclusion, the Sono-Fenton method is suggested to be used more widely in regeneration processes.     

Dehydrogenation kinetics and catalysis of organic heteroaromatics for hydrogen storage

The complete recovery of the H₂ stored on dodecahydro-N-ethylcarbazole was achieved at 443 K and 101 kPa using Pd catalysts prepared by incipient wetness impregnation and calcination in He rather than air. Over a 4 wt% Pd/SiO₂ catalyst, the reaction proceeded to complete conversion within 22 min and complete H₂ recovery (5.8 wt%) within 1.6 h. The dehydrogenation rate of dodecahydro-N-ethylcarbazole and selectivity to the completely dehydrogenated product, N-ethylcarbazole, were dependent upon the Pd particle size. The dehydrogenation rate of dodecahydro-N-ethylcarbazole was compared to that of dodecahydrocarbazole and dodecahydrofluorene. The lower turn-over frequency (TOF) for dodecahydrocarbazole was attributed to a strong adsorption of the dehydrogenated products to Pd through the N atom, whereas the ethyl group in dodecahydro-N-ethylcarbazole prevented a strong N interaction with the surface. Density functional theory (DFT) results showed that dodecahydrocarbazole and dodecahydrofluorene were more strongly adsorbed on Pd than dodecahydro-N-ethylcarbazole leading to a significant decrease in their TOFs for H₂ recovery.     

Modeling Effects of Mass Transfer Rate and Catalyst Concentration on Biodiesel Production in Batch Reactors

This article presents a new approach to investigate the kinetics of sunflower and rapeseed oils methanolysis. Due to its heterogeneous nature, the methanolysis reaction is affected by different physical properties such as mass transfer coefficients and specific surface area of the dispersed phase. Considering these parameters, a model was developed, and was evaluated by comparing the results of the model with the experimental data found in the literature. The mean absolute deviation obtained for sunflower and rapeseed oils is 0.039 mol L^?1, which demonstrates the accuracy of the model. The results show that the mixing speed is more effective in the first few minutes of the process. Furthermore, at mixing speed above 700 rpm, the process is controlled only by the reactions. The rate of biodiesel production increases with increasing catalyst concentration; however, catalyst concentration above 1.5 wt% has little or no significant effect on the rate of biodiesel production. In addition, because of its higher activation energy the rapeseed oil transesterification is more temperature dependent than the sunflower transesterification.     

Progress on Electrospun Composite Fibers Incorporating Bioactive Glass: An Overview

Electrospinning is a promising approach for the development of fibrous tissue engineering (TE) scaffolds suitable for hard and soft tissues. Apart from physicomechanical properties, electrospun fibers are required to incorporate bioactive cues to control cellular functions, including facilitating biomineralization and osteogenic differentiation in case of bone TE, as well as vascularization, to support successful tissue regeneration. In recent years, bioactive glass (BG) addition to electrospun biopolymer fibers has shown promising results in enhancing the properties of fibers, including the improvement of biological performance. In this article, a comprehensive overview of BG-containing electrospun polymer composite fibers is presented, identifying the parameters that affect the mechanical properties as well as the biological response in vivo and in vitro. Subsequently, the effects of BG addition on the properties of the scaffolds are discussed. Recent developments in the fields of bone regeneration, wound healing, and drug delivery using BG-containing electrospun fibrous scaffolds are described in detail. Essential aspects related to BG-polymer composite fibers for translational research in TE are highlighted for future research in this field.     

Extraction of lipid-soluble antioxidants from rosemary leaves using vegetable oils

The objective of this research was to extract carnosic acid and carnosol, natural lipid-soluble antioxidants, from rosemary leaves without the use of chemical aid. Three different vegetable oils [high oleic soybean oil (HOSO), peanut oil (PO) and cottonseed oil (CO)] were used as the medium for extracting rosemary's lipid-soluble antioxidants. Dried rosemary leaves were ground into fine particles, added two of the selected vegetable oils, mixed and heated. The vegetable oil containing the extracted antioxidants was filtered from the rosemary particles and analysed using high-performance liquid chromatography (HPLC). As a control, a common extraction method using ethanol was performed to compare the oil extraction efficiency for carnosic acid and carnosol. HPLC analysis confirmed the presence of carnosic acid and carnosol in all three vegetable oil solutions. Compared to the ethanol extraction, a higher level of the carnosic acid was found in the vegetable oil solutions. Among the vegetable oils, high oleic soybean oil contained the most carnosic acid; however, there were similar amounts of carnosol in all three vegetable oil solutions. The extractions' efficacy was tested on soybean oil's (SO) oxidative stability by adding 2% (w/w) of the antioxidant–vegetable oil solution. The results obtained from peroxide value (PV) and p-anisidine value (AnV) analysis documented a significantly lower degree of oxidation in the soybean oil containing the extracted antioxidant solutions, compared to the pure soybean oil.     

Safety Integrity Level in Valves

Journal of Failure Analysis and Prevention - Safety integrity level (SIL) is a part of an international standard such as IEC 61508 that provides suppliers and end users with a common framework to...