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Sensor technology is one of the most important key technologies of the future with a constantly increasing number of applications, both in the industrial and in the private sectors. More and more gas sensors are used for the control of technical processes, in environment monitoring, healthcare, and automobiles. Consequently, the development of fast and sensitive gas sensors with small cross sensitivity is the subject of intense research, propelled by strategies based on nanoscience and -technology. Established systems can be improved and novel sensor concepts based on bottom-up approaches show that the sensor properties can be controlled by molecular design. This Review highlights the recent developments and reflects the impact of nanoscience on sensor technology. 相似文献
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Kruss S Wolfram T Martin R Neubauer S Kessler H Spatz JP 《Advanced materials (Deerfield Beach, Fla.)》2010,22(48):5499-5506
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Ballesteros B Tobias G Shao L Pellicer E Nogués J Mendoza E Green ML 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(9):1501-1506
Purification and shortening of single-walled carbon nanotubes (SWNTs) is carried out by treatment with steam. During the steam purification the graphitic shells coating the catalytic metal particles are removed. Consequently, the exposed catalytic particles can be easily dissolved by treatment with hydrochloric acid. No damage to the carbon nanotube tubular structure is observed, even after prolonged treatment with steam. Samples are characterized by HRTEM, TGA, magnetic measurements, Raman spectroscopy, AFM, and XPS. 相似文献
46.
Loher S Schneider OD Maienfisch T Bokorny S Stark WJ 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(6):824-832
The antimicrobial activity of silver has attracted significant research interest and contributes to an exponentially growing use of this noble metal in commodity products. In this investigation, we describe a general approach to increase the antimicrobial activity of a silver-containing surface by two to three orders of magnitude. The use of 1-2-nm silver particles decorating the surface of 20-50-nm carrier particles consisting of a phosphate-based, biodegradable ceramic allows the triggered release of silver in the presence of a growing microorganism. This effect is based on the organism's requirements for mineral uptake during growth creating a flux of calcium, phosphate, and other ions to the organism. The growing micro-organism dissolves the carrier containing these nutrients and thereby releases the silver nanoparticles. Further, we demonstrate the rapid self-sterilization of polymer surfaces containing silver on calcium phosphate nanoparticles using a series of human pathogens. Colony-forming units (viable bacteria or fungi counts) have been routinely reduced below detection limit and suggest application of these self-sterilizing surfaces in hospital environments, food and pharmaceutical processing, and personal care. 相似文献
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A.M.M. Abeykoon M. Castro-Colin E.V. Anokhina M.N. Iliev W. Donner M. Brunelli A.J. Jacobson S.C. Moss 《Metallurgical and Materials Transactions A》2008,39(13):3179-3183
Structural studies done on HgSe nanoclusters fabricated in the pores of two types of zeolite frameworks, LTL (tubular pore) and Nd-Y (nearly spherical pore), are presented. Nanoclusters were synthesized in these zeolite frameworks via chemical vapor deposition. Anomalous X-ray scattering (AXS) studies were performed on both HgSe/zeolite-Y and HgSe/zeolite-L systems. As a result, we present two distinct structural models for NdY/HgSe and LTL/HgSe systems. A remarkable feature present in our X-ray diffraction (XRD) patterns, diffuse scattering, will also be discussed using our initial results of the atomic pair distribution function (PDF) studies. X-ray structural work is complemented using the results of optical and Raman studies. This article is based on a presentation given in the symposium entitled “Neutron and X-Ray Studies for Probing Materials Behavior,” which occurred during the TMS Spring Meeting in New Orleans, LA, March 9–13, 2008, under the auspices of the National Science Foundation, TMS, the TMS Structural Materials Division, and the TMS Advanced Characterization, Testing, and Simulation Committee. 相似文献
48.
Landon BE Huskamp HA Tobias C Epstein AM 《The Joint Commission journal on quality improvement》2002,28(2):72-82
BACKGROUND: Concern has been expressed about whether managed care health plans can successfully meet the special needs of Medicaid beneficiaries. A 1996 survey indicated that state Medicaid agencies had just begun conducting quality oversight and management. Since then the federal government has released guidelines under the Quality improvement System for Managed Care (QISMC) program to assist states with quality management of managed care programs. In 1999 a follow-up telephone survey was conducted with representatives from 45 states to describe the current state of and changes in quality management activities by state Medicaid agencies for Medicaid beneficiaries enrolled in managed care. RESULTS: The 45 states represented a 50% increase between 1995 and 1999. The number of states enrolling the disabled had doubled (from 15 to 30). Most states collecting data on satisfaction and childhood immunizations fed it back to health plans, although feedback of other measures of access and quality occurred less frequently and fewer states provided information to beneficiaries choosing health plans. Fewer than 25% of states reported having even one health plan demonstrate improvement in individual measures of access and quality except for prenatal care (28%) and childhood immunizations (33%). Fewer than half of the states included contractual penalties in their contracts with health plans, and very few (three or fewer per penalty) had over invoked such penalties. CONCLUSIONS: State Medicaid agencies continue to adapt to their new roles as value-based purchasers of health care. Although increasing numbers of states collect data on satisfaction, access, and quality of care, few states have been able to document improved performance in the health plans they oversee. 相似文献
49.
Casals E Pfaller T Duschl A Oostingh GJ Puntes VF 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(24):3479-3486
The surface modifications of metal and metal oxide nanoparticles with sizes ranging from 7 to 20 nm dispersed in commonly used cell culture medium supplemented with serum are investigated. All the tested nanoparticles adsorb proteins onto their surface, thereby forming a protein corona through a dynamic process evolving towards an irreversible coating (hard protein corona). Despite the fact that the studied nanomaterials have similar characteristics of hydrophobicity and surface charge, different temporal patterns of the protein corona formation are observed that can be considered a fingerprint for nanoparticle identification. Some of the biological and toxicological implications of the formation of the nanoparticle-protein corona are studied using the human monocytic cell line THP-1 exposed to cobalt oxide nanoparticles. Results show that production of reactive oxygen species is decreased if the nanoparticles are preincubated for 48 h with serum. 相似文献
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