In vivo degradation and tissue compatibility of ZK60 magnesium alloy with micro-arc oxidation coating in a transcortical model

Magnesium alloys were studied extensively as a class of biodegradable metallic materials for medical applications. In the present study, ZK60 magnesium alloy was considered as a candidate and the micro-arc oxidation (MAO) treatment was adopted in order to reduce the degradation rate of the alloy. The in vivo degradation behaviors and biological compatibilities of ZK60 alloys with and without MAO treatment were studied with a transcortical model in rabbits. The implant and the surrounding bone tissues were characterized by CT, SEM and histological methods at 2, 4 and 12 weeks after the implantation. The results demonstrated that both the bare and MAO-coated ZK60 alloys completely degraded within 12 weeks in this animal model. The MAO coating decreased the degradation rate of ZK60 alloy and enhanced the response of the surrounding tissues within the first 2 weeks. After then, an acceleration of the degradation of the MAO-coated ZK60 alloy was observed. It was found that the alloy could be degraded before the complete degradation of the MAO coating, leading to the local peeling off of the coating. An in vivo degradation mechanism of the MAO-coated ZK60 alloy was proposed based on the experimental results. The severe localized degradation caused by the peeling off of the MAO coating was the main reason for the acceleration of the degradation of the MAO-coated ZK60 alloy.     

Application of genetic algorithm for fuzzy rules optimization on semi expert judgment automation using Pittsburg approach

Genetic algorithm is well-known of its best heuristic search method. Fuzzy logic unveils the advantage of interpretability. Genetic fuzzy system exploits potential of optimization with ease of understanding that facilitates rules optimization. This paper presents the optimization of fourteen fuzzy rules for semi expert judgment automation of early activity based duration estimation in software project management. The goal of the optimization is to reduce linguistic terms complexity and improve estimation accuracy of the fuzzy rule set while at the same time maintaining a similar degree of interpretability. The optimized numbers of linguistic terms in fuzzy rules by 27.76% using simplistic binary encoding mechanism managed to improve accuracy by 14.29% and reduce optimization execution time by 6.95% without compromising on interpretability in addition to promote improvement of knowledge base in fuzzy rule based systems.     

The geochemistry of trace elements in marine oil shales and their combustion residues: Occurrence and environmental aspects

With the aim of better understanding geochemistry of trace elements in marine oil shale and its combustion residues, 23 raw samples, 17 oil shale combustion residues, and 18 selected minerals from Bilong Co oil shale are studied. Potentially hazardous trace elements in raw samples include As, B, Cd, Mo, and Se, while Se, Mo, Cd, As, Bi, and U are potentially hazardous trace elements in combustion residues. As is controlled mainly by Fe-bearing minerals. B occurs mainly in clay minerals. Cd is enriched mainly in calcite. Mo is controlled mainly by organic matter. Se is mainly controlled by P-bearing minerals.     

某大型繁忙机场跑道大修工程设计分析

以虹桥机场东跑道大修工程为例,阐述了大修方案提出的技术依据和基础条件,介绍了方案设计中应重点考虑的关键因素,论证了所拟方案的技术合理性,最终形成完整的大修技术方案,为类似工程方案设计提供了参考。     

城市道路隔离护栏清洗技术研究

通过分析护栏污渍的微细成分、分布与动态变化规律,探索了适应工况面的可提高效果及效率的清洗途径。工况试验表明,清洗车优选行进速度为1.9～7.5 km/h,滚刷优选直径为500～600 mm,优选转速为350～500 r/min。针对顽固污渍与深度污染护栏,以四滚刷垂直对夹为框架,通过序配高压水湿润、低压水前喷刷、扫毛刷洗、低压水后喷刷、高压水冲洗的加强清洗模式进行清洗,可使其清洁度提高5%～7%。     

An ejector‐enhanced re‐liquefaction process (EERP) for liquid ethylene vessels

For liquid ethylene gas (LEG) vessels, developing high‐efficient re‐liquefaction plant to handle the continuously yielded boil‐off gas (BOG) could significantly improve its energy efficiency. In this study, an ejector enhanced re‐liquefaction process (EERP) for LEG vessels is proposed to improve the performance of the conventional re‐liquefaction process (CRP) with a cascaded two‐stage compression refrigeration cycle. In Aspen HYSYS, an ejector model was developed to analyse the performance of the proposed cycle system. The effects of the evaporating pressure of upper cycle p_{R0 '} and the intermediate pressures of upper and bottom cycles (p_R3 and p_E3) on the performances of both the CRP and EERP were studied. The results show that better performances can be reached with lower p_{R0 '} for the CRP and EERP. In order to achieve the best performances, the optimal p_R3 and p_E3 are, respectively, lifted to 510 kPa and 630 kPa by the EERP. When the proposed cycle system with the EERP is employed to re‐liquefy 3000 kg/h of ethylene BOG, its coefficient of performance (COP) and exergy efficiency can be improved by 2.95–5.31% and 2.70–4.86% over that of the cycle system with the CRP. Correspondingly, the EERP could reduce the total power consumption of 15.7–27.9 kW compared to the CRP. Copyright © 2016 John Wiley & Sons, Ltd.     

An isoquinoline alkaloid from the Chinese herbal plant Corydalis yanhusuo W.T. Wang inhibits P-glycoprotein and multidrug resistance-associate protein 1

Overexpression of P-glycoprotein (P-gp) and multidrug resistance-associate protein 1 (MRP1) is a major mechanism leading to multidrug resistance (MDR) of cancer cells. These transporters expel anti-cancer drugs and greatly impair therapeutic efficacy of chemotherapy. A Chinese herbal plant Yanhusuo (Corydalis yanhusuo W.T. Wang, YHS) is frequently used in functional food and traditional Chinese medicine to improve the efficacy of chemotherapy. The objective of this work was to study effects of glaucine, an alkaloid component of YHS, on P-gp and MRP1 in resistant cancer cells.The resistant cancer cell line, MCF-7/ADR and corresponding parental sensitive cells were employed to determine reversal properties of glaucine. Glaucine inhibits P-gp and MRP1-mediated efflux and activates ATPase activities of the transporters, indicating that it is a substrate and inhibits P-gp and MRP1 competitively. Furthermore, glaucine suppresses expression of ABC transporter genes. It reverses the resistance of MCF-7/ADR to adriamycin and mitoxantrone effectively.     

Research on Opportunity-Driven Redesign Process to Cooperate With Training Innovative Engineers in China

Many design engineers in cross-domain industries have attended training classes of TRIZ to improve their innovative abilities in China. Most of them are successful, but others are not. So the latest target of the trainers is to improve the training process used now in industry in China and to make the engineers to understand the basic principles of TRIZ better. Based on the mass-engineer-oriented training model(MEOTM) and mechanical engineers' design cases, a relationship between managing activities about the opportunities for innovation and the training process is set up. It is shown that the inventive problems come first from opportunity searching for engineers. A training and gate system for evaluation is developed to involve the managing activities of the companies in the training process. Then comparison between the general analogous process and the application of TRIZ is made, which shows the advantages and depth principles of TRIZ for the engineers to apply them confidently. Lastly a new process is formed in which opportunity searching, engineers training, inventive problems identifying and solving,and three redesign paths are connected seamlessly. The research proposes an opportunity-driven redesign path that cooperates the training and opportunity searching, which will be applied in future training classes to make more and more engineers to follow.     

Controlled oxidative nanopatterning of microrough titanium surfaces for improving osteogenic activity

To further enhance the biological properties of acid-etched microrough titanium surfaces, titania nanotextured thin films were produced by simple chemical oxidation, without significantly altering the existing topographical and roughness features. The nanotextured layers on titanium surfaces can be controllably varied by tuning the oxidation duration time. The oxidation treatment significantly reduced water contact angles and increased the surface energy compared to the surfaces prior to oxidation. The murine bone marrow stromal cells (BMSCs) were used to evaluate the bioactivity. In comparison, oxidative nanopatterning of microrough titanium surfaces led to improved attachment and proliferation of BMSCs. The rate of osteoblastic differentiation was also represented by the increased levels of alkaline phosphatase activity and mineral deposition. These data indicated that oxidative nanopatterning enhanced the biological properties of the microrough titanium surfaces by modulating their surface chemistry and nanotopography. Based on the proven mechanical interlocking ability of microtopographies, enhancement of multiple osteoblast functions attained by this oxidative nanopatterning is expected to lead to better implant osseointegration in vivo.     

Effect of ultrasonic pretreatment on the antioxidant properties of porcine liver protein hydrolysates

In this study, the effect of ultrasonic pretreatment on the antioxidant activity of porcine liver protein hydrolysates (PLPHs) was investigated. The results showed that the degree of hydrolysis (DH) and peptide contents of the PLPHs increased as the time of ultrasonication increased. The hydrolysate pretreated with ultrasonication for 60 s exhibited the highest DH and peptide contents. The hydrolysate pretreated with ultrasonication for 45 s exhibited the highest ferrous ion chelating ability and reducing power. The hydrolysate pretreated with ultrasonication for 30 s exhibited the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity and the higher inhibitory activity in the linoleic acid autoxidation system. The molecular weight of peptides in the hydrolysates was less than 6.2 kDa. The results clearly demonstrated that ultrasonic pretreatment enhances the antioxidant activities of the PLPHs in a short period of time (15–30 s).