19,639 research outputs found
Sea-surface temperature and salinity mapping from remote microwave radiometric measurements of brightness temperature
A technique to measure remotely sea surface temperature and salinity was demonstrated with a dual frequency microwave radiometer system. Accuracies in temperature of 1 C and in salinity of part thousand for salinity greater than 5 parts per thousand were attained after correcting for the influence of extraterrestrial background radiation, atmospheric radiation and attenuation, sea-surface roughness, and antenna beamwidth. The radiometers, operating at 1.43 and 2.65 GHz, comprise a third-generation system using null balancing and feedback noise injection. Flight measurements from an aircraft at an altitude of 1.4 km over the lower Chesapeake Bay and coastal areas of the Atlantic Ocean resulted in contour maps of sea-surface temperature and salinity with a spatial resolution of 0.5 km
Purification and quantification of recombinant Epstein-Barr viral glycoproteins gp350/220 from Chinese hamster ovary cells
Truncated Epstein-Barr virus (EBV) membrane antigen gp350/220 (EBV-MA) lacking the membrane anchor was expressed and secreted into the medium of recombinant Chinese hamster ovary cells that had been cultured in Plasmapur hollow-fibre modules using defined serum-free medium. The EBV-MA in the medium was concentrated by 70% (w/v) ammonium sulphate precipitation and subsequently purified by immunoaffinity chromatography using an anti-EBV-MA (EBV.0T6) monoclonal antibody (mAb) column. Adsorbed antigen was eluted with 3 M MgCl2 in phosphate-buffered saline, concentrated by Mono Q anion-exchange chromatography and analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, silver staining and Western blotting using EBV-positive serum and anti-EBV-MA specific mAbs. Monospecific polyclonal rabbit antibodies against the purified EBV-MA were raised and purified by protein G affinity chromatography. For the measurement of EBV-MA antigen levels a sandwich enzyme-linked immunosorbent assay using rabbit polyclonal antibodies and a horseradish peroxidase-conjugated anti-MA mAb was developed having a detection level of 10 ng/ml
Glucocorticoids for human skin: New aspects of the mechanism of action
Topical glucocorticoids have always been considered first-line drugs for inflammatory diseases of the skin and bronchial system. Applied systemically, glucocorticoids are used for severe inflammatory and immunological diseases and the inhibition of transplant rejection. Owing to the progress in molecular pharmacology, the knowledge of the mechanism of action has increased during the last years. Besides distinct genomic targets, which are due to the activation of specific cytoplasmatic receptors resulting in the (trans-) activation or (trans-) repression of target genes, there are non-genomic effects on the basis of the interference with membrane-associated receptors as well as with membrane lipids. In fact, various glucocorticoids appear to differ with respect to the relative influence on these targets. Thus, the extended knowledge of glucocorticoid-induced cellular signalling should allow the design and development of even more specifically acting drugs-as it has been obtained with other steroids, e.g. estrogens for osteoporosis prevention. Copyright (C) 2005 S. Karger AG, Basel
Fatal lymphoproliferation and acute monocytic leukemia-like disease following infectious mononucleosis in the elderly
Three elderly patients are reported, in whom serologically confirmed recent infectious mononucleosis is followed by fatal lymphoproliferation (case 1), by acute monocytic leukemia (case 2), and by acute probably monocytic leukemia (case 3)
Dry and wet interfaces: Influence of solvent particles on molecular recognition
We present a coarse-grained lattice model to study the influence of water on
the recognition process of two rigid proteins. The basic model is formulated in
terms of the hydrophobic effect. We then investigate several modifications of
our basic model showing that the selectivity of the recognition process can be
enhanced by considering the explicit influence of single solvent particles.
When the number of cavities at the interface of a protein-protein complex is
fixed as an intrinsic geometric constraint, there typically exists a
characteristic fraction that should be filled with water molecules such that
the selectivity exhibits a maximum. In addition the optimum fraction depends on
the hydrophobicity of the interface so that one has to distinguish between dry
and wet interfaces.Comment: 11 pages, 7 figure
Influence of correlations on molecular recognition
The influence of the patchiness and correlations in the distribution of
hydrophobic and polar residues at the interface between two rigid biomolecules
on their recognition ability is investigated in idealised coarse-grained
lattice models. A general two-stage approach is utilised where an ensemble of
probe molecules is designed first and the recognition ability of the probe
ensemble is related to the free energy of association with both the target
molecule and a different rival molecule in a second step. The influence of
correlation effects are investigated using numerical Monte Carlo techniques and
mean field methods. Correlations lead to different optimum characteristic
lengths of the hydrophobic and polar patches for the mutual design of the two
biomolecules on the one hand and their recognition ability in the presence of
other molecules on the other hand.Comment: 15 pages, 5 figure
A universal platform for magnetostriction measurements in thin films
We present a universal nanomechanical sensing platform for the investigation
of magnetostriction in thin films. It is based on a doubly-clamped silicon
nitride nanobeam resonator covered with a thin magnetostrictive film. Changing
the magnetization direction within the film plane by an applied magnetic field
generates a magnetostrictive stress and thus changes the resonance frequency of
the nanobeam. A measurement of the resulting resonance frequency shift, e.g. by
optical interferometry, allows to quantitatively determine the magnetostriction
constants of the thin film. We use this method to determine the
magnetostriction constants of a 10nm thick polycrystalline cobalt film, showing
very good agreement with literature values. The presented technique can be
useful in particular for the precise measurement of magnetostriction in a
variety of (conducting and insulating) thin films, which can be deposited by
e.g. electron beam deposition, thermal evaporation or sputtering
The circumstellar envelope of AFGL 4106
We present new imaging and spectroscopy of the post-red supergiant binary
AFGL 4106. Coronographic imaging in H-alpha reveals the shape and extent of the
ionized region in the circumstellar envelope (CSE). Echelle spectroscopy with
the slit covering almost the entire extent of the CSE is used to derive the
physical conditions in the ionized region and the optical depth of the dust
contained within the CSE.
The dust shell around AFGL 4106 is clumpy and mixed with ionized gas. H-alpha
and [N II] emission is brightest from a thin bow-shaped layer just outside of
the detached dust shell. On-going mass loss is traced by [Ca II] emission and
blue-shifted absorption in lines of low-ionization species. A simple model is
used to interpret the spatial distribution of the circumstellar extinction and
the dust emission in a consistent way.Comment: 10 pages, 11 figures. Accepted for publication in Astronomy &
Astrophysics Main Journa
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