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Corresponding Variation (corresponding + variation)
Selected AbstractsA Multifunctional Nanodevice Capable of Imaging, Magnetically Controlling, and In Situ Monitoring Drug ReleaseADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Shang-Hsiu Hu Abstract The multifunctional nanodevice described here integrates nanoscaled imaging, targeting, and controlled drug delivery, as well as the capability to monitor, in situ, the amount of drug released from the nanodevice with single-cell resolution. The nanodevice is composed of a polymer core/single-crystal iron oxide shell nanostructure bonded to a quantum dot. It shows outstanding release and retention characteristics via an external on/off manipulation of a high-frequency magnetic field. Upon magnetic stimulation, the single-crystal iron oxide shell demonstrates formation of nanometer-sized polycrystal domains of varying orientation. This allows a variation between retention and slow release of the drug. Further stimulation causes permanent rupturing of the shell, causing release of the drug in a burst-like manner. The quantum dot bonded to the nanodevice provides optical information for in situ monitoring of the drug release through use of a magnetic field. Remote control drug release from the nanodevice in a cancerous cell line (HeLa) was successfully accomplished using the same induction scenario. When nanodevices equipped with quantum dots are taken into cancerous cells, they are able to provide real-time drug dose information through a corresponding variation in emission spectrum. The nanodevice designed in this study has achieved its potential as a cell-based drug-delivery system for therapeutic applications. [source] Diffusion through time-dependent mediaGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2000M. Holschneider Summary In this theoretical paper we show how to solve a time-dependent diffusion equation by means of a perturbation series. This technique is applied to the case of diffusion of a liquid through a time-dependent porous matrix. We compute to first order the phase and amplitude relations between the small deformation of the transporting matrix and the corresponding variation of the saturation at the surface. In particular we show that, for a large frequency range, there is a constant phase shift of ,/2 between the matrix and the surface saturation variations. Since the conductivity is to first approximation proportional to the saturation at the surface, this might explain the observed phase relations observed in an experiment in a cave near Abaratsubo (Japan). [source] pH-induced on,off switching of polycarbonate track-etched membranes by plasma-induced surface graftingPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 10 2010Chunyan Li Abstract Surface functionalization of the plasma-pretreated polycarbonate (PC) track-etched membranes via plasma-induced thermally graft copolymerization of acrylic acid (AAc) was carried out. The resulting PC membranes with grafted AAc side chains were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis. The morphology of the PC membranes was studied by scanning electron microscopy (SEM). The results showed that the grafted PAAc polymers were formed uniformly inside the pores throughout the entire membrane thickness. With increase in the pore-filling ratio, the pore diameters of PAAc-grafted membranes became smaller. The PC-g-PAAc membranes exhibit rapid and reversible response of the flux to the environmental pH as pH is switched between 3 and 9. Between pH 3.5 and 5.5, the membranes demonstrate a pH-valve function as the carboxyl group changes from neutral to charged with a corresponding variation in chain configuration. Copyright © 2009 John Wiley & Sons, Ltd. [source] Association among growth, food consumption-related traits and amylase gene polymorphism in the Pacific oyster Crassostrea gigasANIMAL GENETICS, Issue 6 2008A. Huvet Summary To examine further a previously reported association between amylase gene polymorphism and growth in the Pacific oyster Crassostrea gigas, ecophysiological parameters and biochemical and molecular expression levels of ,-amylase were studied in Pacific oysters of different amylase genotypes. Genotypes that previously displayed significantly different growth were found to be significantly different for ingestion and absorption efficiency. These estimated parameters, used in a dynamic energy budget model, showed that observed ingestion rates (unlike absorption efficiencies) allowed an accurate prediction of growth potential in these genotypes. The observed association between growth and amylase gene polymorphism is therefore more likely to be related to ingestion than to absorption efficiency. Additionally, relative mRNA levels of the two amylase cDNAs were also strongly associated with amylase gene polymorphism, possibly reflecting variation in an undefined regulatory region, although no corresponding variation was observed in specific amylase activity. Amylase gene sequences were determined for each genotype, showing the existence of only synonymous or functionally equivalent non-synonymous polymorphisms. The observed associations among growth, food consumption-related traits and amylase gene polymorphism are therefore more likely to be related to variation in the level of amylase gene expression than to functional enzymatic variants. [source] Geochemistry of the Cenozoic Potassic Volcanic Rocks in the West Kunlun Mountains and Constraints on Their SourcesACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2004ZHANG Zhaochong Abstract, The geochemical characteristics of the Cenozoic volcanic rocks from the north Pulu, east Pulu and Dahongliutan regions in the west Kunlun Mountains are somewhat similar as a whole. However, the volcanic rocks from the Dahongliutan region in the south belt are geochemically distinguished from those in the Pulu region; Nd, 207Pb/204Pb and 208Pb/204Pb. Their trace elements and isotopic data suggest that they were derived from lithospheric mantle, consisting of biotite- and hornblende-bearing garnet lherzolite, which had undertaken metasomatism and enrichment. On the primitive mantle-normalized patterns, they display remarkably negative Nb and Ta anomalies, indicating the presence of early-stage subducted oceanic crust. The metasomatism and enrichment resulted from the fluid released from the crustal materials enclosed in the source region in response to the uplift of asthenospheric mantle. Based on the previous experiments it can be inferred that the thickness of the lithosphere ranges from 75 to 100 km prior to the generation of the magmas. However, the south belt differs from the north one by its thicker lithosphere and lower degree of partial melting. The different thickness of the lithosphere gives rise to corresponding variation of the degree of crustal contamination. The volcanic rocks in the south belt are much more influenced by crustal contamination. In view of the tectonic setting, the generation of potassic magmas is linked with the uplift of asthenosphere resulted from large-scale thinning of the lithosphere after the collision of Indian and Eurasian plates, whereas the thinning of the lithosphere may result from delamination. The potassic magmas mainly resulted from partial melting of lithosphere mantle caused by the uplift of asthenosphere. [source] | |||||||||||||