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21.
Gláucia K. Braga 《Drying Technology》2013,31(2):303-310
The aim of this work was to determine specifications for spray-drying manufacturing of sustained-release drug-loaded microparticles with potential application in dentistry. Chitosan was used as the microencapsulation polymer and ketoprofen as the model drug. A 1:1 chitosan/ketoprofen suspension was spray-dried under different operating conditions. The size distribution, morphology, total drug load, and release profile of the powders were characterized. In vitro release studies were performed with the powder samples entrapped in cellulose dialysis tubes. The microparticles produced had a narrow size distribution (mean diameter ranging from 2.11 to 3.27 µm), good sphericity, and a smooth surface. In vitro release studies showed a linear drug dissolution behavior. 相似文献
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This article discusses the methodological problems of integrating scientometric methods into a qualitative study. Integrative
attempts of this kind are poorly supported by the methodologies of both the sociology of science and scientometrics. Therefore
it was necessary to develop a project-specific methodological approach that linked scientometric methods to theoretical considerations.
The methodological approach is presented and used to discuss general methodological problems concerning the relation between
(qualitative) theory and scientometric methods. This discussion enables some conclusions to be drawn as to the relations that
exist between scientometrics and the sociology of science.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Glässer 《Holz als Roh- und Werkstoff》1968,26(3):100-108
Ohne Zusammenfassung 相似文献
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Models and indicators characterizing the dynamics of national publication productivity distributions are presented. The indicator triplet: transience, renewal, and dynamism is used to describe the «physical shape» of a national scientific community. 相似文献
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Schlorf T Meincke M Kossel E Glüer CC Jansen O Mentlein R 《International journal of molecular sciences》2010,12(1):12-23
Superparamagnetic iron-oxide particles (SPIO) are used in different ways as contrast agents for magnetic resonance imaging (MRI): Particles with high nonspecific uptake are required for unspecific labeling of phagocytic cells whereas those that target specific molecules need to have very low unspecific cellular uptake. We compared iron-oxide particles with different core materials (magnetite, maghemite), different coatings (none, dextran, carboxydextran, polystyrene) and different hydrodynamic diameters (20-850 nm) for internalization kinetics, release of internalized particles, toxicity, localization of particles and ability to generate contrast in MRI. Particle uptake was investigated with U118 glioma cells und human umbilical vein endothelial cells (HUVEC), which exhibit different phagocytic properties. In both cell types, the contrast agents Resovist, B102, non-coated Fe(3)O(4) particles and microspheres were better internalized than dextran-coated Nanomag particles. SPIO uptake into the cells increased with particle/iron concentrations. Maximum intracellular accumulation of iron particles was observed between 24 h to 36 h of exposure. Most particles were retained in the cells for at least two weeks, were deeply internalized, and only few remained adsorbed at the cell surface. Internalized particles clustered in the cytosol of the cells. Furthermore, all particles showed a low toxicity. By MRI, monolayers consisting of 5000 Resovist-labeled cells could easily be visualized. Thus, for unspecific cell labeling, Resovist and microspheres show the highest potential, whereas Nanomag particles are promising contrast agents for target-specific labeling. 相似文献