236 research outputs found
Quantum-limited directional amplifiers with optomechanics
Directional amplifiers are an important resource in quantum information
processing, as they protect sensitive quantum systems from excess noise. Here,
we propose an implementation of phase-preserving and phase-sensitive
directional amplifiers for microwave signals in an electromechanical setup
comprising two microwave cavities and two mechanical resonators. We show that
both can reach their respective quantum limits on added noise. In the reverse
direction, they emit thermal noise stemming from the mechanical resonators and
we discuss how this noise can be suppressed, a crucial aspect for technological
applications. The isolation bandwidth in both is of the order of the mechanical
linewidth divided by the amplitude gain. We derive the bandwidth and
gain-bandwidth product for both and find that the phase-sensitive amplifier has
an unlimited gain-bandwidth product. Our study represents an important step
toward flexible, on-chip integrated nonreciprocal amplifiers of microwave
signals
Effect of bone decalcification procedures on DNA in situ hybridization and comparative genomic hybridization. EDTA is highly preferable to a routinely used acid decalcifier
Decalcification is routinely performed for histological studies of
bone-containing tissue. Although DNA in situ hybridization (ISH) and
comparative genomic hybridization (CGH) have been successfully employed on
archival material, little has been reported on the use of these techniques
on archival decalcified bony material. In this study we compared the
effects of two commonly used decalcifiers, i.e. , one proprietary,
acid-based agent (RDO) and one chelating agent (EDTA), in relation to
subsequent DNA ISH and CGH to bony tissues (two normal vertebrae, six
prostate tumor bone metastases with one sample decalcified by both EDTA
and RDO). We found that RDO-decalcified tissue was not suited for DNA ISH
in tissue sections with centromere-specific probes, whereas we were able
to adequately determine the chromosomal status of EDTA-decalcified
material of both control and tumor material. Gel electrophoresis revealed
that no DNA could be successfully retrieved from RDO-treated material.
Moreover, in contrast to RDO-decalcified tumor material, we detected
several chromosomal imbalances in the EDTA-decalcified tumor tissue by CGH
analysis. Furthermore, it was possible to determine the DNA ploidy status
of EDTA- but not of RDO-decalcified material by DNA flow cytometry.
Decalcification of bony samples by EDTA is highly recommended for
application in DNA ISH and CGH techniques
Interphase cytogenetics and comparative genomic hybridization of human epithelial cancers and precursor lesions
Molecular cytogenetic evaluation of gastric cardia adenocarcinoma and precursor lesions
Analyses of cancer incidence data in the United States and Western Europe
revealed steadily rising rates over the past decades of adenocarcinomas of
the esophagus and gastric cardia. Genetic information on gastric cardia
adenocarcinoma and its preneoplasias is sparse. We have used comparative
genomic hybridization to obtain a genome-wide overview of 20 archival
gastric cardia adenocarcinomas and 10 adjacent preneoplastic lesions (
Neuroendocrine Cells in Barrett's Mucosa and Adenocarcinomas of the Gastroesophageal Junction
Pancreatic fibrosis correlates with exocrine pancreatic insufficiency after pancreatoduodenectomy
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