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排序方式: 共有419条查询结果,搜索用时 15 毫秒
411.
412.
Letícia Dias de Melo Carrasco Jorge Luiz Mello Sampaio Ana Maria Carmona-Ribeiro 《International journal of molecular sciences》2015,16(3):6337-6352
The growing challenge of antimicrobial resistance to antibiotics requires novel synthetic drugs or new formulations for old drugs. Here, cationic nanostructured particles (NPs) self-assembled from cationic bilayer fragments and polyelectrolytes are tested against four multidrug-resistant (MDR) strains of clinical importance. The non-hemolytic poly(diallyldimethylammonium) chloride (PDDA) polymer as the outer NP layer shows a remarkable activity against these organisms. The mechanism of cell death involves bacterial membrane lysis as determined from the leakage of inner phosphorylated compounds and possibly disassembly of the NP with the appearance of multilayered fibers made of the NP components and the biopolymers withdrawn from the cell wall. The NPs display broad-spectrum activity against MDR microorganisms, including Gram-negative and Gram-positive bacteria and yeast. 相似文献
413.
Oil price volatility and stock price fluctuations in an emerging market: Evidence from South Korea 总被引:1,自引:0,他引:1
How important are oil price fluctuations and oil price volatility on equity market performance? What are the policy implications if volatility turns out to be significant? We assess this issue in an economics/finance nexus for Korea using a VEC model including interest rates, economic activity, real stock returns, real oil prices and oil price volatility. Our main aim is to capture the effects of crude oil prices on the Korean economy thoroughly covering the period of the Asian Financial Crisis of 1997, which heavily affected the country, and the oil price hikes in the early 1990s after the Gulf War. South Korea was the country most hit by the financial crisis together with Indonesia and Thailand. Results indicate the dominance of oil price volatility on real stock returns and emphasize how this has increased over time. Oil price volatility can have profound effect on the time horizon of investment and firms need adjust their risk management procedures accordingly. This increase in dependency has been found in other net oil importing emerging equity markets. We test the relationship between oil price movements and economic activity by using modern time series techniques in a cointegrating framework. We expand the standard error correction model by examining the dynamics of out of sample causality through the generalized variance decomposition and impulse response function techniques. The evidence from persistence profiles also gives important guidelines based on how fast the entire system adjusts back to equilibrium. In addition, we find the cointegrating relationship to be stable and find that the linear error correction model to be more favorable than an asymmetric 2 period Markov switching model. 相似文献
414.
dos Santos Sarah Marcilene Machado de Mello Prado Renato Teixeira Gelza Carliane Marques de Souza Júnior Jonas Pereira de Medeiros Robson Luis Silva Barreto Rafael Ferreira 《SILICON》2022,14(3):773-782
Silicon - The aim of this study was to determine whether silicon (Si) supplied via nutrient solution or foliar spray is nutritionally and physiologically efficient in mitigating potassium (K)... 相似文献
415.
Fernando de Mello Franco 《Architectural Design》2011,81(3):80-85
In the last few years, the emergence of a burgeoning middle class in Brazil has transformed the country into one of the fastest growing consumer markets in the world. For MMBB Arquitetos, based in São Paulo, social mobility and the upgrading of urban infrastructure represent a unique opportunity to develop the city. Fernando de Mello Franco of MMBB describes the practice's strategy for ‘urbanising’ much needed new infrastructure. A canal with a public park can be inserted, for instance, alongside a new drainage system, providing necessary social adhesion in a fragile urban culture. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
416.
Renata Botti Murilo D. M. Innocentini Thais A. Faleiros Cristina F. P. R. Paschoalato Murilo F. Mello Giorgia Franchin Paolo Colombo 《International Journal of Applied Ceramic Technology》2022,19(2):794-802
Geopolymer powders and 3D-printed lattices have shown promising preliminary results as heterogeneous catalysts for the transesterification of vegetable oils to produce biodiesel. However, questions about the basicity of catalytic sites and the leaching characteristics of metals (K, Na) and hydroxyl groups in the reactional mixtures remained. The leaching of alkaline ions in methanol and biodiesel for powder and printed geopolymer formulations based on K, Na, or Na+K activators and treated at 110 to 700°C was investigated, as well as the physiochemical modifications of the materials. The Hammett indicators were used to determine base strength, and both leachable and total basicities were quantified. The amount of Na and K leached into the biodiesel phase was negligible (<1% wt.%). Methanol leaching reached a maximum of 29.3%. The base strength ranged between 11.0 and 18.4. Potassium-based geopolymer lattices presented the highest basicity, followed by sodium and sodium-potassium geopolymer catalysts. The basicity of all formulations decreased gradually as the calcination temperature increased. When compared to the homogeneous catalysts NaOH and KOH, the level of biodiesel contamination with Na and K is 81–93% lower. The findings support the heterogeneous nature of geopolymers as biodiesel catalysts and further validates their use for this application. 相似文献
417.
Flores Rilner Alves Pessoa-de-Souza Marco Aurélio de Andrade Aline Franciel Bueno Amanda Magalhães de Oliveira Abdala Klaus de Souza Júnior Jonas Pereira de Mello Prado Renato Santos Glenio Guimarães Mesquita Marcio 《SILICON》2022,14(7):3591-3600
Silicon - Silicon, although not an essential element for plant, when it is absorbed can alter cells flexibility, and then may affect plant architecture; reduce leaf senescence and deleterious... 相似文献
418.
de Farias Guedes Victor Hugo de Mello Prado Renato Frazão Joaquim José Oliveira Kamilla Silva Cazetta Jairo Osvaldo 《SILICON》2022,14(1):281-287
Silicon - Foliar-applied silicon may reduce the damage caused by zinc (Zn) deficiency in plants. While adding silicon (Si) and Zn to the solution may increase foliar fertilization efficiency, Si... 相似文献
419.