656 research outputs found
Quantum Chessboards in the Deuterium Molecular Ion
We present a new algorithm for vibrational control in deuterium molecules
that is feasible with current experimental technology. A pump mechanism is used
to create a coherent superposition of the D2+ vibrations. A short, intense
infrared control pulse is applied after a chosen delay time to create selective
interferences. A `chessboard' pattern of states can be realized in which a set
of even- or odd-numbered vibrational states can be selectively annihilated or
enhanced. A technique is proposed for experimental realization and observation
of this effect using 5 fs pulses of 790 nm radiation, with intermediate
intensity (5e13 W/cm2)Comment: 12 pages, 5 figure
Immunoregulatory Potential of Exosomes Derived from Cancer Stem Cells.
Head and neck squamous cell carcinomas (HNSCCs) are malignancies that originate in the mucosal lining of the upper aerodigestive tract. Despite advances in therapeutic interventions, survival rates among HNSCC patients have remained static for years. Cancer stem cells (CSCs) are tumor-initiating cells that are highly resistant to treatment, and are hypothesized to contribute to a significant fraction of tumor recurrences. Consequently, further investigations of how CSCs mediate recurrence may provide insights into novel druggable targets. A key element of recurrence involves the tumor's ability to evade immunosurveillance. Recent published reports suggest that CSCs possess immunosuppressive properties, however, the underlying mechanism have yet to be fully elucidated. To date, most groups have focused on the role of CSC-derived secretory proteins, such as cytokines and growth factors. Here, we review the established immunoregulatory role of exosomes derived from mixed tumor cell populations, and propose further study of CSC-derived exosomes may be warranted. Such studies may yield novel insights into new druggable targets, or lay the foundation for future exosome-based diagnostics
Prohibition on research involving psychiatric patients subject to coercion
This paper compares legislation on clinical research conducted on patients subject to coercion in the Scandinavian countries and the UK, examines it from a human rights perspective, and problematizes the Danish legal model as the only one employing a total ban on this kind of research. Reference is made to the consequences to evidence-based psychiatric care improvements and international ethical principle statements generally entitling psychiatric patients to treatment under similar ethical and scientific conditions as patients with other illnesses, given the absolute premise that the patient does not object to research participation and always retains the right to withdraw
Copy number variants are produced in response to low‐dose ionizing radiation in cultured cells
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106089/1/em21840.pd
Differential gene expression between fall- and spring-run Chinook salmon assessed by long serial analysis of gene expression
Author Posting. © American Fisheries Society, 2008. This article is posted here by permission of American Fisheries Society for personal use, not for redistribution. The definitive version was published in Transactions of the American Fisheries Society 137 (2008): 1378–1388, doi:10.1577/T07-222.1.Of all Pacific salmonids, Chinook salmon Oncorhynchus tshawytscha display the greatest variability in return times to freshwater. The molecular mechanisms of these differential return times have not been well described. Current methods, such as long serial analysis of gene expression (LongSAGE) and microarrays, allow gene expression to be analyzed for thousands of genes simultaneously. To investigate whether differential gene expression is observed between fall- and spring-run Chinook salmon from California's Central Valley, LongSAGE libraries were constructed. Three libraries containing between 25,512 and 29,372 sequenced tags (21 base pairs/tag) were generated using messenger RNA from the brains of adult Chinook salmon returning in fall and spring and from one ocean-caught Chinook salmon. Tags were annotated to genes using complementary DNA libraries from Atlantic salmon Salmo salar and rainbow trout O. mykiss. Differentially expressed genes, as estimated by differences in the number of sequence tags, were found in all pairwise comparisons of libraries (freshwater versus saltwater = 40 genes; fall versus spring = 11 genes; and spawning versus nonspawning = 51 genes). The gene for ependymin, an extracellular glycoprotein involved in behavioral plasticity in fish, exhibited the most differential expression among the three groupings. Reverse transcription polymerase chain reaction analysis verified the differential expression of ependymin between the fall- and spring-run samples. These LongSAGE libraries, the first reported for Chinook salmon, provide a window of the transcriptional changes during Chinook salmon return migration to freshwater and spawning and increase the amount of expressed sequence data.This work was supported with a grant from the
California Department of Water Resources awarded to
M.A.B.; J.C.B. received additional funding from the
North Umpqua Foundation, Roseburg, Oregon
Observation of confined current ribbon in JET plasmas
we report the identification of a localised current structure inside the JET
plasma. It is a field aligned closed helical ribbon, carrying current in the
same direction as the background current profile (co-current), rotating
toroidally with the ion velocity (co-rotating). It appears to be located at a
flat spot in the plasma pressure profile, at the top of the pedestal. The
structure appears spontaneously in low density, high rotation plasmas, and can
last up to 1.4 s, a time comparable to a local resistive time. It considerably
delays the appearance of the first ELM.Comment: 10 pages, 6 figure
Risk of Kaposi's sarcoma and of other cancers in Italian renal transplant patients
A follow-up study of 1844 renal transplant patients in Italy showed a 113-fold increased risk for Kaposi's sarcoma. Kaposi's sarcoma risk was higher in persons born in southern than in northern Italy. Significant increases were also observed for cancers of the lip, liver, kidney and for non-Hodgkin's lymphoma
An evolutionary timeline of the oxytocin signaling pathway.
Oxytocin is a neuropeptide associated with both psychological and somatic processes like parturition and social bonding. Although oxytocin homologs have been identified in many species, the evolutionary timeline of the entire oxytocin signaling gene pathway has yet to be described. Using protein sequence similarity searches, microsynteny, and phylostratigraphy, we assigned the genes supporting the oxytocin pathway to different phylostrata based on when we found they likely arose in evolution. We show that the majority (64%) of genes in the pathway are 'modern'. Most of the modern genes evolved around the emergence of vertebrates or jawed vertebrates (540 - 530 million years ago, 'mya'), including OXTR, OXT and CD38. Of those, 45% were under positive selection at some point during vertebrate evolution. We also found that 18% of the genes in the oxytocin pathway are 'ancient', meaning their emergence dates back to cellular organisms and opisthokonta (3500-1100 mya). The remaining genes (18%) that evolved after ancient and before modern genes were classified as 'medium-aged'. Functional analyses revealed that, in humans, medium-aged oxytocin pathway genes are highly expressed in contractile organs, while modern genes in the oxytocin pathway are primarily expressed in the brain and muscle tissue
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