314 research outputs found
EpCAM expression in lymph node and bone metastases of prostate carcinoma: A pilot study
There is an urgent need for new imaging modalities in prostate carcinoma staging. A non-invasive modality that can assess lymph node and bone metastases simultaneously is preferred. Epithelial cell adhesion molecule (EpCAM) is a membranous protein of interest as an imaging target since it is overexpressed in prostatic carcinoma compared with benign prostate epithelium and compared with stroma. However, EpCAM expression in lymph node metastases is sparsely available in the literature and EpCAM expression in bone metastases is yet unknown. The current study evaluates the expression of EpCAM in prostate carcinoma lymph nodes, in matched normal lymph nodes, in prostate carcinoma bone metastases, and in normal bone by immunohistochemistry. EpCAM was expressed in 100% of lymph node metastases (21 out of 21), in 0% of normal lymph nodes (0 out of 21), in 95% of bone metastases (19 out of 20), and in 0% of normal bone (0 out of 14). Based on these results, EpCAM may be a feasible imaging target in prostate carcinoma lymph node and bone metastases. Prospective clinical trials are needed to confirm current results. Preoperative visualization of prostate carcinoma metastases will improve disease staging and will prevent unnecessary invasive surgery
Stabilization of i-motif structures by 2'-ÎČ-fluorination of DNA
i-Motifs are four-stranded DNA structures consisting of two parallel DNA duplexes held together by hemi-protonated and intercalated cytosine base pairs (C:CH). They have attracted considerable research interest for their potential role in gene regulation and their use as pH responsive switches and building blocks in macromolecular assemblies. At neutral and basic pH values, the cytosine bases deprotonate and the structure unfolds into single strands. To avoid this limitation and expand the range of environmental conditions supporting i-motif folding, we replaced the sugar in DNA by 2-deoxy-2-fluoroarabinose. We demonstrate that such a modification significantly stabilizes i-motif formation over a wide pH range, including pH 7. Nuclear magnetic resonance experiments reveal that 2-deoxy-2-fluoroarabinose adopts a C2'-endo conformation, instead of the C3'-endo conformation usually found in unmodified i-motifs. Nevertheless, this substitution does not alter the overall i-motif structure. This conformational change, together with the changes in charge distribution in the sugar caused by the electronegative fluorine atoms, leads to a number of favorable sequential and inter-strand electrostatic interactions. The availability of folded i-motifs at neutral pH will aid investigations into the biological function of i-motifs in vitro, and will expand i-motif applications in nanotechnology.Funding for open access charge: NSERC Discovery grant (to M.J.D., A.K.M.); CIHR DDTP Training Grant (to H.A., R.H.V.); MINECO [BFU2014-52864-R to C.G.]; CSIC-JAE contract (to N.M.P.).Peer Reviewe
One-Way Entangled-Photon Autocompensating Quantum Cryptography
A new quantum cryptography implementation is presented that combines one-way
operation with an autocompensating feature that has hitherto only been
available in implementations that require the signal to make a round trip
between the users. Using the concept of advanced waves, it is shown that this
new implementation is related to the round-trip implementations in the same way
that Ekert's two-particle scheme is related to the original one-particle scheme
of Bennett and Brassard. The practical advantages and disadvantages of the
proposed implementation are discussed in the context of existing schemes.Comment: 5 pages, 1 figure; Minor edits--conclusions unchanged; accepted for
publication in Physical Review
On the thin-shell limit of branes in the presence of Gauss-Bonnet interactions
In this paper we study thick-shell braneworld models in the presence of a
Gauss-Bonnet term. We discuss the peculiarities of the attainment of the
thin-shell limit in this case and compare them with the same situation in
Einstein gravity. We describe the two simplest families of thick-brane models
(parametrized by the shell thickness) one can think of. In the thin-shell
limit, one family is characterized by the constancy of its internal density
profile (a simple structure for the matter sector) and the other by the
constancy of its internal curvature scalar (a simple structure for the
geometric sector). We find that these two families are actually equivalent in
Einstein gravity and that the presence of the Gauss-Bonnet term breaks this
equivalence. In the second case, a shell will always keep some non-trivial
internal structure, either on the matter or on the geometric sectors, even in
the thin-shell limit.Comment: 17 pages, 2 figures, RevTeX 4. Revised version accepted for
publication in Physical Review
Multiorder coherent Raman scattering of a quantum probe field
We study the multiorder coherent Raman scattering of a quantum probe field in
a far-off-resonance medium with a prepared coherence. Under the conditions of
negligible dispersion and limited bandwidth, we derive a Bessel-function
solution for the sideband field operators. We analytically and numerically
calculate various quantum statistical characteristics of the sideband fields.
We show that the multiorder coherent Raman process can replicate the
statistical properties of a single-mode quantum probe field into a broad comb
of generated Raman sidebands. We also study the mixing and modulation of photon
statistical properties in the case of two-mode input. We show that the prepared
Raman coherence and the medium length can be used as control parameters to
switch a sideband field from one type of photon statistics to another type, or
from a non-squeezed state to a squeezed state and vice versa.Comment: 12 pages, 7 figures, to be published in Phys. Rev.
Measurement-induced nonlinearity in linear optics
Published versio
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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