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A novel species of DNA--protein conjugate was synthesized by chemically linking DNA oligonucleotides to Aequorea victoria green fluorescent protein mutant EYFP. An additional cysteine was added to the C-terminus of the EYFP by genetic engineering and used to covalently attach amino-modified oligonucleotide with the aid of the heterobifunctional crosslinker sSMCC. EYFP maintained its fluorescence upon conjugation. The oligonucleotide provides an additional binding site to the fluorescent protein, and hence, the EYFP conjugate could be specifically hybridized with both complementary DNA-protein conjugates in-solution as well as immobilized at capture oligonucleotides attached to a solid substrate. These studies are paving the way for future applications in the self-assembly of photoactive supramolecular complexes, such as artificial light-harvesting systems. 相似文献
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Ohne Zusammenfassung
Accuracy of the graphite furnace AAS for trace determinations in foodstuffs相似文献
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We present a novel technique that intrinsically mitigates the quantum-defect heating in Raman lasers. The basic principle of this so-called "coherent anti-Stokes Raman scattering (CARS)-based heat mitigation" is to suppress the phonon creation in the Raman medium by increasing the number of out-coupled anti-Stokes photons with respect to the number of out-coupled Stokes photons. We demonstrate with the aid of numerical simulations that for a hydrogen and a silicon Raman laser, CARS-based heat mitigation efficiencies of at least 30% and 35%, respectively, can be obtained. 相似文献
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Teuscher C 《Chaos (Woodbury, N.Y.)》2007,17(2):026106
Future nanoscale electronics built up from an Avogadro number of components need efficient, highly scalable, and robust means of communication in order to be competitive with traditional silicon approaches. In recent years, the networks-on-chip (NoC) paradigm emerged as a promising solution to interconnect challenges in silicon-based electronics. Current NoC architectures are either highly regular or fully customized, both of which represent implausible assumptions for emerging bottom-up self-assembled molecular electronics that are generally assumed to have a high degree of irregularity and imperfection. Here, we pragmatically and experimentally investigate important design tradeoffs and properties of an irregular, abstract, yet physically plausible three-dimensional (3D) small-world interconnect fabric that is inspired by modern network-on-chip paradigms. We vary the framework's key parameters, such as the connectivity, number of switch nodes, and distribution of long- versus short-range connections, and measure the network's relevant communication characteristics. We further explore the robustness against link failures and the ability and efficiency to solve a simple toy problem, the synchronization task. The results confirm that (1) computation in irregular assemblies is a promising and disruptive computing paradigm for self-assembled nanoscale electronics and (2) that 3D small-world interconnect fabrics with a power-law decaying distribution of shortcut lengths are physically plausible and have major advantages over local two-dimensional and 3D regular topologies. 相似文献
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In this contribution we discuss the role disordered (or random) systems have played in the study of non-Gibbsian measures.
This role has two main aspects, the distinction between which has not always been fully clear: 1) From disordered systems: Disordered systems can be used as a tool; analogies with, as well as results and methods from the study
of random systems can be employed to investigate non-Gibbsian properties of a variety of measures of physical and mathematical
interest. 2) Of disordered systems: Non-Gibbsianness is a property of various (joint) measures describing quenched disordered systems. We
discuss and review this distinction and a number of results related to these issues. Moreover, we discuss the mean-field version
of the non-Gibbsian property, and present some ideas how a Kac limit approach might connect the finite-range and the mean-field
non-Gibbsian properties. 相似文献
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Jing Wang Christof Asbach Heinz Fissan Tim Hülser Thomas A. J. Kuhlbusch Drew Thompson David Y. H. Pui 《Journal of nanoparticle research》2011,13(4):1373-1387
Nanotechnology has great potential to transform science and industry in the fields of energy, material, environment, and medicine.
At the same time, more concerns are being raised about the occupational health and safety of nanomaterials in the workplace
and the implications of nanotechnology on the environment and living systems. Studies on environmental, health, and safety
(EHS) issues of nanomaterials have a strong influence on public acceptance of nanotechnology and, eventually, affect its sustainability.
Oversight and regulation by government agencies and non-governmental organizations (NGOs) play significant roles in ensuring
responsible and environmentally friendly development of nanotechnology. The EHS studies of nanomaterials can provide data
and information to help the development of regulations and guidelines. We present research results on three aspects of EHS
studies: physico-chemical characterization and measurement of nanomaterials; emission, exposure, and toxicity of nanomaterials;
and control and abatement of nanomaterial releases using filtration technology. Measurement of nanoparticle agglomerates using
a newly developed instrument, the Universal NanoParticle Analyzer (UNPA), is discussed. Exposure measurement results for silicon
nanoparticles in a pilot scale production plant are presented, as well as exposure measurement and toxicity study of carbon
nanotubes (CNTs). Filtration studies of nanoparticle agglomerates are also presented as an example of emission control methods. 相似文献
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Adams GJ Greene J Vick GW Harrist R Kimball KT Karmonik C Ballantyne CM Insull W Morrisett JD 《Magnetic resonance imaging》2004,22(9):1249-1258
BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) can accurately and reproducibly measure the volume of atherosclerotic plaque in human carotid arteries. Atherosclerotic plaques may either progress or regress over time, depending on individual risk factors and treatment regimens. This study was designed to determine if regression or progression of human carotid atherosclerosis in patients receiving statin therapy over 24 months can be detected by high-resolution MRI. METHODS: In 11 subjects who had undergone unilateral carotid endarterectomy and were on statin therapy, volumes for total carotid artery, concentric wall (normal wall), eccentric wall (plaque), and lumen were quantified at 0, 16 and 24 months using a 1.5-T human imager equipped with 6-cm phased array coils. RESULTS: The interobserver mean coefficient of variation (CV) was lowest for the lumen volume (3.1%) and highest for the plaque volume (9.8%). The interscan mean CV was lowest for the total artery volume (3.2%) and highest for the plaque volume (9.9%). As much as 26% regression and 35% progression were observed in individual subject's carotid artery eccentric wall (plaque) volumes over time. Mean eccentric wall volume increased 5% by 16 months and 8% by 24 months. Mean total wall volume increased slightly at both 16 and 24 months (+1.2% and +1.8%). CONCLUSIONS: High-resolution MRI provides a noninvasive reproducible method of tracking changes in carotid atherosclerosis. This pilot study detected changes in individual subjects at both 16 and 24 months. MRI tracking of changes in atherosclerotic plaques should prove useful in assessing vascular disease risk and monitoring the efficacy of interventions designed to induce regression or retard progression. 相似文献
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