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The growth of nanotechnology has led to an unprecedented research and development effort in both the public and the private sectors; world wide, an increasing number of laboratories, fabrication and manufacturing plants develop or apply novel nanometre-sized materials for applications ranging from large-scale industrial materials, to electronic components and healthcare and medical products; an increasing number of start-ups have been launched to establish their nanotechnology-based products in a trillion-dollar market.

Very little, however, is known about the interaction of man-made nanostructured materials and living organisms, as studies of nanotoxicology are gaining increasing interest, but are still in their infancy. Despite the formation of many focus and lobbying groups, proper legislation of the environmental, health and safety aspects of nanotechnology will take years to be implemented. In the mean time, it is of utmost importance that companies working with nanometre-sized matter take appropriate precautions to protect their staff, the environment and the customer. Toxicology tests and agency approval of new nanometre-sized materials are prohibitively expensive, but, even if working on a tight budget, nanotechnology companies can achieve an ethical and safe business conduct via a number of possible routes.  相似文献   

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This research investigates the growing phenomenon of university–industry (U–I) collaboration in high-tech strategic projects in China. After significant changes in the trading policies of 1978, China has gained heightened attention in technology and innovation. To achieve the stated strategic national goals, Research and Development (R&D) collaboration is essential. Organizations preferred to collaborate in order to share the burden of R&D costs and efforts. The academic outputs (research publications) of Chinese academic institutions and technology patenting ratio are increasing daily in China. These increasing numbers signal the importance of R&D. High-tech industries are inclined to share projects with universities. Foreign enterprises, state supported enterprises and local industry have played key roles to strengthening university–industry relationships.  相似文献   

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Strain-rate cycling tests associated with ultrasonic oscillation were carried out at 80–239 K for two kinds of KCl:Sr2+ (0.05 mol.% in the melt) single crystals: one is a quenched specimen and the other an annealed one. In this study, it was found that the density of moving dislocation is not influenced by the heat treatment. Furthermore, the increase in forest dislocation density for the annealed specimen seemed to be remarkable under the compression test, compared with that for the quenched specimen. As a result, the strain-hardening rate increased and the extent of plastic deformation region became short at a given temperature by annealing the quenched specimens. The investigation concerning forest dislocation density was conducted on the basis of the which will represent the variation of the strain-rate sensitivity due to dislocation cuttings with shear strain.  相似文献   

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Purpose: To develop an osmotically-driven pellet coated with polymeric film for sustained release of oxymatrine (OMT), a freely water soluble drug.

Methods: Pellet containing OMT and sodium chloride (NaCl), an osmotically active agent, were prepared by extrusion/spheronization and then coated with acrylic copolymers (Eudragit® RS 30 D) by the fluidized bed coating process. In vitro release and swelling behavior studies were employed to optimize and to evaluate the sustained-release behavior from the osmotically-driven pellets with film coated. Finally, in vivo evaluation in rabbits was employed to investigate the sustained plasma level of OMT and its active metabolite matrine.

Results: It was found that the F3 formulation, prepared with 20% NaCl and an 8% coating level, showed a continuous NaCl-induced water influx into the pellets providing a gradual sustained release of OMT for over 12?h. Finally, we confirmed that oral OMT with sustained release led to a gradual sustained plasma profile of both OMT, with a reduction in its bioavailability, and MT with an increase in the bioavailability compared with that of oral OMT with immediate release. Conclusions: The pharmaceutical parameters obtained suggested the potential usefulness of oral OMT with sustained release for the treatment of stress ulcers, as well as reducing the risk of MT-induced side effects.  相似文献   

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