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Fast Development (fast + development)

Distribution by Scientific Domains
Life Sciences33%
Chemistry33%

Selected Abstracts

Recent Progress in n-Channel Organic Thin-Film Transistors

ADVANCED MATERIALS, Issue 12 2010
Yugeng Wen
Abstract Particular attention has been focused on n-channel organic thin-film transistors (OTFTs) during the last few years, and the potentially cost-effective circuitry-based applications in flexible electronics, such as flexible radiofrequency identity tags, smart labels, and simple displays, will benefit from this fast development. This article reviews recent progress in performance and molecular design of n-channel semiconductors in the past five years, and limitations and practicable solutions for n-channel OTFTs are dealt with from the viewpoint of OTFT constitution and geometry, molecular design, and thin-film growth conditions. Strategy methodology is especially highlighted with an aim to investigate basic issues in this field. [source]

Advances in laser technology for isolated attosecond pulse generation

LASER PHYSICS LETTERS, Issue 4 2009
C. Vozzi
Abstract In this review we report on recent advances in laser technology, which have contributed to the fast development of attosecond science. In particular we will concentrate on two experimental methods for the generation of high-peak-power, fewoptical-cycle laser pulses with controlled electric field, which are crucial for the generation of isolated attosecond pulses. The first method is the hollow-fiber compression technique, introduced in 1996 and now routinely used in several laboratories. So far, isolated attosecond pulses have been generated by using few-cycle pulses produced by such compression technique, in combination with active stabilization of the carrier-envelope phase. More recently, few-cycle pulses tunable in the infrared region have been generated by optical parametric amplification with passive stabilization of the carrier-envelope phase. Such parametric sources represent excellent drivers for the generation of harmonic radiation with an extended cutoff, and offer the possibility to extend attosecond science towards the soft-X rays region. Finally, we will briefly discuss the basic elements of attosecond metrology. (© 2009 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Molecular characterization of esterase E3 gene associated with organophosphorus insecticide resistance in the New World screwworm fly, Cochliomyia hominivorax

MEDICAL AND VETERINARY ENTOMOLOGY, Issue 2009
R. A. CARVALHO
Abstract The New World screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), is one of the most important myiasis-causing flies in South America. It is responsible for severe economic losses to livestock producers, mainly because it causes mortality in newborn calves and reductions in the quality of leather and in the production of milk and meat. The economic losses caused by myiasis, along with those caused by other internal and external parasites, are the main factors limiting meat production. In Brazil, C. hominivorax has been controlled by applying insecticides, particularly organophosphate (OP)-based compounds. However, the improper and continuous use of these chemicals can lead to the selection of OP-resistant strains. This, associated with the fast development of OP resistance in other myiasis-causing flies, shows the importance of investigating resistance in C. hominivorax. Based on the findings of previous studies, the objective of the current work was to isolate and sequence the E3 gene in C. hominivorax. Mutations at the positions (Gly137 and Trp251) responsible for conferring OP resistance in Lucilia cuprina and Musca domestica L. (Muscidae) were identified in C. hominivorax. In addition, the orthologous region in C. hominivorax contained motifs that are highly conserved among carboxyl/cholinesterases and contribute to the catalytic mechanism of the active site. The characterization of this gene in natural populations of New World screwworm can be an important tool for monitoring resistance to insecticides throughout its current geographic distribution. This will provide information for the selection and implementation of more effective pest management programmes. [source]

Evaluating soil rhizobacteria for their ability to enhance plant growth and tuber yield in potato

ANNALS OF APPLIED BIOLOGY, Issue 2 2010
A. Oswald
The objectives of this study were to identify promising microorganisms to improve potato productivity in low-input systems of tropical highlands and to compare results from in vitro, greenhouse and field experiments to advance the development of a screening method for rhizobacteria and develop an efficient assessment of their effect on plant growth in field conditions. A total of 150 bacterial strains were screened in vitro, in greenhouse and field trials. The series of experiments confirmed the plant growth-promoting ability of a range of rhizobacteria. Although in vitro and greenhouse results were promising, the field experiment showed variability and the results require further verification. The in vitro tests might have limited value for screening as no correlation could be found between in vitro tests and pot trial results. However, trials in controlled conditions produced insights into the mechanisms causing better plant growth in potato, such as early tuberisation, fast development of leaf area and probably greater photosynthetic rates. [source]

Protein adsorption at air,water interfaces: A combination of details

BIOPOLYMERS, Issue 1-2 2004
Harmen H. J. de Jongh
Abstract Using a variety of spectroscopic techniques, a number of molecular functionalities have been studied in relation to the adsorption process of proteins to air,water interfaces. While ellipsometry and drop tensiometry are used to derive information on adsorbed amount and exerted surface pressure, external reflection circular dichroism, infrared, and fluorescence spectroscopy provide, next to insight in layer thickness and surface layer concentration, molecular details like structural (un)folding, local mobility, and degree of protonation of carboxylates. It is shown that the exposed hydrophobicity of the protein or chemical reactivity of solvent-exposed groups may accelerate adsorption, while increased electrostatic repulsion slows down the process. Also aggregate formation enhances the fast development of a surface pressure. A more bulky appearance of proteins lowers the collision intensity in the surface layer, and thereby the surface pressure, while it is shown to be difficult to affect protein interactions within the surface layer on basis of electrostatic interactions. This work illustrates that the adsorption properties of a protein are a combination of molecular details, rather than determined by a single one. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004 [source]

Doing Homogeneous Catalysis between Basic Research and Application

CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 8 2006
M. BellerArticle first published online: 3 AUG 200
Abstract Recent achievements in applied homogeneous catalysis are described. Special focus is given on the development of novel palladium catalysts which are of industrial interest for the synthesis of bulk and fine chemicals. Most of the reported work has been done in an intensive collaboration between the Degussa AG (DHC) and the Leibniz-Institut für Katalyse e.V. The clear vision of the goal and a close interaction of basic research and applied catalysis have led to a fast development from the initial discovery to the upscaling of the ligands. Such a combination of know how from academic and industrial partners will provide the basis for further innovations in catalysis in future. [source]