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131.
We report a procedure to prepare a conducting nano-composites composed of multi-walled carbon nanotubes (MWNTs) and PEDOT by using a poly(sodium 4-styrenesulfonate) (PSSNa) as a inter-linking molecule between MWNT and PEDOT. When PSSNa chains are introduced on the MWNTs via physicochemical interaction, the surface of MWNT becomes negatively charged, and PSS-modified MWNTs promote the effective association of the positively charged PEDOT chains. The resulting MWNT-PSS/PEDOT composites are characterized by a better interconnection between MWNT and PEDOT components. 相似文献
132.
Haliza Katas Maria Abdul Ghafoor Raja Lee Choy Ee 《Drug development and industrial pharmacy》2014,40(11):1443-1450
Recently, a newly discovered Dicer-substrate siRNA (DsiRNA) demonstrates higher potency in gene silencing than siRNA but both suffer from rapid degradation, poor cellular uptake and chemical instability. Therefore, Tat-peptide was exploited to protect and facilitate their delivery into cells. In this study, Tat-peptide was complexed with siRNA or DsiRNA through simple complexation. The physicochemical properties (particle size, surface charge and morphology) of the complexes formed were then characterized. The ability of Tat-peptide to carry and protect siRNA or DsiRNA was determined by UV-Vis spectrophotometry and serum protection assay, respectively. Cytotoxicity effect of these complexes was assessed in V79 cell line. siRNA-Tat complexes had particle size ranged from 186?±?17.8 to 375?±?8.3?nm with surface charge ranged from ?9.3?±?1.0 to +13.5?±?1.0?mV, depending on the Tat-to-siRNA concentration ratio. As for DsiRNA-Tat complexes, the particle size was smaller than the ones complexed with siRNA, ranging from 176?±?8.6 to 458?±?14.7?nm. Their surface charge was in the range of +27.1?±?3.6 to +38.1?±?0.9?mV. Both oligonucleotide (ON) species bound strongly to Tat-peptide, forming stable complexes with loading efficiency of more than 86%. These complexes were relatively non cytotoxic as the cell viability of ~90% was achieved. In conclusion, Tat-peptide has a great potential as siRNA and DsiRNA vector due to the formation of stable complexes with desirable physical characteristics, low toxicity and able to carry high amount of siRNA or DsiRNA. 相似文献
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135.
High Charge‐Carrier Mobility of 2.5 cm2 V−1 s−1 from a Water‐Borne Colloid of a Polymeric Semiconductor via Smart Surfactant Engineering
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136.
137.
Locally Welded Silver Nano‐Network Transparent Electrodes with High Operational Stability by a Simple Alcohol‐Based Chemical Approach
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Haifei Lu Di Zhang Jiaqi Cheng Jian Liu Jian Mao Wallace C. H. Choy 《Advanced functional materials》2015,25(27):4211-4218
As an indispensable aspect of emerging flexible optoelectronics, flexible transparent electrodes, especially those comprised of metal nanowires, have attracted great attentions recently. Welding the nanowire junctions is an effective strategy for reducing the sheet resistance and improving the operational stability of flexible nanowire electrode in practical applications. Herein, a simple alcohol‐based solution approach is proposed to weld crossed silver nanowires by chemically growing silver “solder” at the junctions of the nanowires, forming transparent silver nano‐network electrodes with improved electrical conductivity and operational stability. Remarkably, silver nano‐networks can be rapidly formed by this simple approach under ambient condition and room temperature, requiring no assistance from heat, light, electrical current, or mechanical pressure. Furthermore, our results show that the nano‐network electrode formed from large diameter nanowires offers a better operational stability, whose trend is opposite to that of the untreated electrodes. To demonstrate the potential application of the highly stable silver nano‐network from large diameter nanowires, organic solar cells fabricated on the nano‐network electrode incorporated with silicon dioxide nanoparticles achieve comparable performance to the ITO control device. Consequently, strategy demonstrated in this work can contribute to low‐cost and highly stable transparent electrodes in emerging flexible optoelectronics. 相似文献
138.
Fah Choy Chia Martin Skitmore Goran Runeson Adrian Bridge 《Construction Management & Economics》2013,31(12):1055-1069
The construction industry is an industry of major strategic importance. Its level of productivity has a significant effect on national economic growth. Productivity indicators are examined. The indicators consist of labour productivity, capital productivity, labour competitiveness, capital intensity and added value content of data, which are obtained from the published census/biannual surveys of the construction industry between the years 1999 and 2011 from the Department of Statistics of Malaysia. The results indicated that there is an improvement in the labour productivity, but the value-added content is declining. The civil engineering and special trades subsectors are more productive than the residential and non-residential subsectors in terms of labour productivity because machine-for-labour substitution is a more important process in those subsectors. The capital-intensive characteristics of civil engineering and special trade works enable these subsectors to achieve higher added value per labour cost but not the capital productivity. The added value per labour cost is lower in larger organizations despite higher capital productivity. However, the capital intensity is lower and unit labour cost is higher in the larger organizations. 相似文献
139.
Fah Choy Chia Martin Skitmore Goran Runeson Adrian Bridge 《Construction Management & Economics》2013,31(9):874-887
The productivity of the construction industry has a significant effect on national economic growth. Gains from higher construction productivity flow through the economy, as all industries rely on construction to some extent as part of their business investment. Contractions and expansions of economic activity are common phenomena in an economy. Three construction cycles occurred between the years 1970 and 2011 in Malaysia. The relationships between construction productivity and economic development are examined by the partial correlation method to establish the underlying factors driving the change in construction productivity. Construction productivity is statistically significantly correlated with gross domestic product (GDP) per capita in a positive direction for the 1985–98 and 1998–2009 cycles, but not the 1970–85 cycle. Fluctuations in construction activities and the influx of foreign workers underlie the changes of construction productivity in the 1985–98 cycle. There was less fluctuation in construction activities in the 1998–2009 cycle, with changes being mainly due to the fiscal stimulation policies of the government in attempting to stabilize the economy. The intensive construction of mega-projects resulted in resource constraints and cost pressures during the 1980s and 1990s. A better management of the ‘boom-bust’ nature of the construction business cycle is required to maintain the capability and capacity of the industry. 相似文献
140.
Zambaga Otgonbayar Kwang Youn Cho Chong-Hun Jung Won-Chun Oh 《Frontiers of Chemical Science and Engineering》2022,16(10):1438
The development of CO2 into hydrocarbon fuels has emerged as a green method that could help mitigate global warning. The novel structured photocatalyst is a promising material for use in a photocatalytic and magneto-electrochemical method that fosters the reduction of CO2 by suppressing the recombination of electron−hole pairs and effectively transferring the electrons to the surface for the chemical reaction of CO2 reduction. In our study, we have developed a novel-structured AgCuZnS2–graphene–TiO2 to analyze its catalytic activity toward the selective evolution of CO2. The selectivity of each nanocomposite substantially enhanced the activity of the AgCuZnS2–graphene–TiO2 ternary nanocomposite due to the successful interaction, and the selectivity of the final product was improved to a value 3 times higher than that of the pure AgCuZnS2 and 2 times higher than those of AgCuZnS2–graphene and AgCuZnS2–TiO2 under ultra-violet (UV)-light (λ = 254 nm) irradiation in the photocatalytic process. The electrochemical CO2 reduction test was also conducted to analyze the efficacy of the AgCuZnS2–graphene–TiO2 when used as a working electrode in laboratory electrochemical cells. The electrochemical process was conducted under different experimental conditions, such as various scan rates (mV·s–1), under UV-light and with a 0.07 T magnetic-core. The evolution of CO2 substantially improved under UV-light (λ = 254 nm) and with 0.07 T magnetic-core treatment; these improvements were attributed to the facts that the UV-light activated the electron-transfer pathway and the magnetic core controlled the pathway of electron-transmission/prevention to protect it from chaotic electron movement. Among all tested nanocomposites, AgCuZnS2–graphene–TiO2 absorbed the CO2 most strongly and showed the best ability to transfer the electron to reduce the CO2 to methanol. We believe that our newly-modeled ternary nanocomposite opens up new opportunities for the evolution of CO2 to methanol through an electrochemical and photocatalytic process. 相似文献