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51.
The absorption of a resonant coupling laser driving a closed degenerate two-level system in an atomic cesium beam was investigated as a function of the detuning of a second laser probing the same transition. The measurements were performed for four different polarization combinations of the two laser beams. Except for the beams of counterrotating polarizations all coupling-laser absorption profiles showed "absorption within transparency," i.e., the absorption in the region around the two-photon resonance was smaller than the absorption corresponding to the one-photon transition induced by the coupling laser, and an extra absorption peak was observed on this curve at the two-photon resonance. With regard to the beams of counterrotating polarizations we observed a switch from absorption within transparency to "transparency within transparency" when the probe-laser power exceeded the constant coupling-laser power. In other words, the cesium ensemble became mostly transparent to the coupling-laser beam at the two-photon resonance. 相似文献
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Characterization and functionalization of cellulose microbeads for extracorporeal blood purification
Marion Ettenauer Fritz Loth Katrin Thümmler Steffen Fischer Viktoria Weber Dieter Falkenhagen 《Cellulose (London, England)》2011,18(5):1257-1263
In the frame of this work, cellulose microbeads with an average particle size of 2.3 μm were characterized with respect to
porosity using a batch solute exclusion method and two groups of model substances, namely proteins and polystyrene sulfonates.
The pores of the microbeads were almost completely accessible to proteins with Stokes radii below 2.5 nm. More than 60% of
the pores were accessible to albumin, which is relevant for the application in blood purification, since many target substances
are albumin bound. Activation of the microbeads with increasing amounts of sodium metaperiodate yielded matrices with dialdehyde
contents between 100 and 1,000 μmol/g. The activated beads were well suited for the covalent attachment of functional ligands,
such as antibodies. Immobilization of antibodies against the pro-inflammatory cytokine TNF-α resulted in efficient TNF-α adsorbents
which possess application potential in extracorporeal blood purification, e.g. for the modulation of cytokine levels as supportive
therapy for sepsis and other inflammatory disorders. 相似文献
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Katrin Schumacher 《Czechoslovak Mathematical Journal》2009,59(3):637-648
Given a domain Ω of class C
k,1, k ∈ ℕ, we construct a chart that maps normals to the boundary of the half space to normals to the boundary of in the sense
that (∂/∂x
n
)α(x′, 0) = − N(x′) and that still is of class C
k,1. As an application we prove the existence of a continuous extension operator for all normal derivatives of order 0 to k on domains of class C
k,1. The construction of this operator is performed in weighted function spaces where the weight function is taken from the class
of Muckenhoupt weights. 相似文献
59.
Next‐Generation o‐Nitrobenzyl Photolabile Groups for Light‐Directed Chemistry and Microarray Synthesis 下载免费PDF全文
Nicole Kretschy Ann‐Katrin Holik Prof. Veronika Somoza Dr. Klaus‐Peter Stengele Prof. Mark M. Somoza 《Angewandte Chemie (International ed. in English)》2015,54(29):8555-8559
Light as an external trigger is a valuable and easily controllable tool for directing chemical reactions with high spatial and temporal accuracy. Two o‐nitrobenzyl derivatives, benzoyl‐ and thiophenyl‐NPPOC, undergo photo‐deprotection with significantly improved efficiency over that of the commonly used NPPOC group. The two‐ and twelvefold increase in photo‐deprotection efficiency was proven using photolithograph synthesis of microarrays. 相似文献
60.
Marta Espina Palanco Klaus Bo Mogensen Katrin Kneipp 《Journal of Raman spectroscopy : JRS》2016,47(2):156-161
We report surface‐enhanced Raman studies on intact plant material using onion layers as a biological target, and silver nanoaggregates and silver island films as enhancing plasmonic structures. Surface‐enhanced Raman scattering (SERS) enhancement allows the detection of strong Raman signatures of chemical constituents of the surface of the onion layer such as cellulose, proteins, and flavonols. Because of long‐time incubation, SERS sensors can access the extracellular space in the inner of the layer. The location of silver nanoparticles inside the onion layer has been monitored by the SERS images collected from chemicals present in the onion and/or reporter molecules attached to the nanoparticles. Our studies show a competitive adsorption of intrinsic bio molecules of the onion layer and reporter molecules. Different spectra from different places of the layer indicate the complex heterogeneous chemical structure of the plant material. The pH‐sensitive reporter molecule para mercapto benzoic acid attached to the nanoparticles allows us to infer pH values inside the extracellular matrix of the onion layer. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献