The aim of this study was to fabricate docetaxel loaded nanocapsules (DTX-NCs) with a high payload using Layer-by-Layer (LbL) technique by successive coating with alternate layers of oppositely charged polyelectrolytes. Developed nanocapsules (NCs) were characterized in terms of morphology, particle size distribution, zeta potential (ζ-potential), entrapment efficiency and in vitro release. The morphological characteristics of the NCs were assessed using transmission electron microscopy (TEM) that revealed coating of polyelectrolytes around the surface of particles. The developed NCs successfully attained a submicron particle size while the ζ-potential of optimized NCs alternated between (+) 34.64?±?1.5 mV to (?) 33.25?±?2.1 mV with each coating step. The non-hemolytic potential of the NCs indicated the suitability of the developed formulation for intravenous administration. A comparative study indicated that the cytotoxicity of positively charged NCs (F4) was significant higher (p?0.05) rather than negative charged NCs (F3), plain drug (DTX) and marketed preparation (Taxotere®) when evaluated in vitro on MCF-7 cells. Furthermore, cell uptake studies evidenced a higher uptake of positive NCs (≥1.2 fold) in comparison to negative NCs. In conclusion, formulated NCs are an ideal vehicle for passive targeting of drugs to tumor cells that may result in improved efficacy and reduced toxicity of encapsulated drug moiety. 相似文献
Scientometrics - The currently prevailing international ranking systems for institutions are limited in their assessment as they only provide assessments either at an overall level or at very broad... 相似文献
The present work focused on the comparative analysis of organic Rankine cycle (ORC) operated with nanoparticles. The effect of CuO and Al2O 3 nanoparticles synthesized with water and circulated within heat exchangers are examined. Thermal efficiency and levelized energy cost (LEC) of the nanofluid based ORC are evaluated simultaneously in the present work. The optimization problem of ORC is formed and solved using heat transfer search algorithm. Operating parameters of the nanofluid based ORC such as pinch point temperature difference of heat exchangers, evaporation pressure, the mass flow rate of refrigerant, and concentration of nanoparticles are investigated in the optimization study. Further, the effect of turbine ratio, heat source temperature, and mass flow rate of heat source fluid on CuO and Al 2O 3 based ORC is explored and discussed. It was observed that a total variation of 35.2% was obtained at the cost of 3.5% variation in LEC between extreme design points. The maximum thermal efficiency of 19.3% and 19.32% can be obtained with CuO and Al 2O 3 with 2.616 and 2.62 $/kWh, respectively. Comparative results reveal that CuO based ORC shows dominance in terms of economic performance over Al 2O 3 based ORC for any given value of the thermal efficiency. 相似文献
Scientometrics - Open Access has emerged as an important movement worldwide during the last decade. There are several initiatives now that persuade researchers to publish in open access journals... 相似文献
Journal of Computational Electronics - In this paper, a new method for the cross-term-free Wigner–Ville distribution (WVD) is proposed. The proposed method is based on sliding... 相似文献
Analysis of everyday work practices in sociotechnical systems for eliciting design/intervention requirements involves appropriate work analysis frameworks. The current article provides an extension to one such framework — Cognitive Work Analysis (CWA) — by scrutinising its sociotechnical basis. CWA's forte depends on its ‘design for adaptation’, system related operations, and operators. In contrast, sociotechnical work systems require not only operators and adaptation, but also a significant emphasis on ‘users’ and ‘appropriation’. The current article extends CWA (based on Rasmussen's original concepts) for users; subsequently allowing for system flexibility and possibilities of ‘appropriation’ within acceptable boundaries of the system's correct functioning. To this end, the first phase of Work Domain Analysis is extended by adding a new layer to the abstraction hierarchy (AH), based on Rasmussen's original insights. 相似文献
One of the strategies to overcome the drawbacks of fast charge recombination of a photocatalyst is to develop semiconductor heterostructures. Herein, we report a two-step precipitation-hydrothermal process to create CuFeO2-ZnO heterostructures with different weight percentages of CuFeO2 (0.5, 1, 5, and 10%). Though X-ray diffraction detected the presence of CuFeO2 on ZnO above 5%, Raman spectroscopy could reveal the presence of CuFeO2 phase as low as 0.5 wt%. For all of the compositions, the bandgap of ZnO did not vary (3.15 eV) on forming heterostructures with CuFeO2. The oxidation of methylene blue under sunlight was used to determine the photocatalytic performance of the heterostructures. In comparison to pure ZnO and CuFeO2, CuFeO2-ZnO heterostructures exhibited a better photocatalytic efficiency. Overall, 5 wt% CuFeO2 on ZnO showed 100% degradation with a rate constant of 0.272?±?0.002 min?1, which is 16 times faster than ZnO. Time-resolved photoluminescence analysis indicated a higher lifespan of charge carriers in the 5wt% CuFeO2-ZnO heterostructure (32.3 ns) than that of CuFeO2 (0.85 ns) and ZnO (27.6 ns). The Mott–Schottky flat band potentials of ZnO and CuFeO2 was determined to be -0.82 and 1.17 eV, respectively, revealing the presence of Type I heterostructures. The heterostructures also showed outstanding recyclability, with a degradation rate of 97% even after four cycles. The current study shows the significance of forming p-type CuFeO2 and n-type ZnO heterostructures for enhanced photocatalysis.
Human Factors and Ergonomics (HFE) recognises itself as a design-driven, systemic and scientific discipline geared towards well-being and performance. Being a scientific discipline and design-oriented requires that the epistemic basis of science and design/engineering be fully comprehended. In interdisciplinary research where these two viewpoints meet, there are often dilemmas posed in terms of knowledge construction and labelling of activity. Therefore, this article scrutinises these two orientations and addresses the differences and commonalities, using case studies from engineering and psychological science (both constituents of HFE). Based on these insights, a way forward is suggested in terms of (1) a reflexive engagement with epistemic concepts and methods; (2) finding a conceptual space for balancing and bridging the science-engineering divide; (3) comprehending ‘design-thinking/design knowledge’ and not treating it as an application of science; (4) providing emphasis on problem formulation and practices of HFE focusing on developing them in systemic terms. 相似文献
Delay tolerant networks (DTNs) are characterized by delay and intermittent connectivity. Satisfactory network functioning in a DTN relies heavily on co-ordination among participating nodes. However, in practice, such co-ordination cannot be taken for granted due to possible misbehaviour by relay nodes. Routing in a DTN is, therefore, vulnerable to various attacks, which adversely affect network performance. Several strategies have been proposed in the literature to alleviate such vulnerabilities—they vary widely in terms of throughput, detection time, overhead etc. One key challenge is to arrive at a tradeoff between detection time and overhead. We observe that the existing table-based reactive strategies to combat Denial-of-service (DoS) attacks in DTN suffer from two major drawbacks: high overhead and slow detection. In this paper, we propose three secure, light-weight and time-efficient routing algorithms for detecting DoS attacks (Blackhole and Grey-hole attacks) in the Spray & Focus routing protocol. The proposed algorithms are based on use of a small fraction of privileged (trusted) nodes. The first strategy, called TN, outperforms the existing table-based strategy with 20–30 % lesser detection time, 20–25 % higher malicious node detection and negligible overhead. The other two strategies, CTN_MI and CTN_RF explore the novel idea that trusted nodes are able to utilize each others’ information/experience using their long range connectivity as and when available. Simulations performed using an enhanced ONE simulator reveals that investing in enabling connectivity among trusted nodes (as in CTN_RF) can have significant performance benefits. 相似文献