176 research outputs found

    A feasibility study of indocyanine green fluorescence mapping for sentinel lymph node detection in cutaneous melanoma

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    Objectives: Sentinel lymph node biopsy (SLNB) is standard of care for staging regional LN in AJCC stage IB-IIC melanoma; using dual localization with radiolabelled colloid and blue dye. Combining these gives optimal accuracy; drawbacks include cumulative radiation exposure for healthcare workers, coordination between disciplines and anaphylaxis. An alternative tracer agent is indocyanine green (ICG); an optical enhancer that fluoresces in the near infrared range. This prospective cohort study assesses the feasibility of using ICG as a tracer agent to detect SLN in cutaneous melanoma. Methods: Primary melanoma patients diagnosed with pT1b-pT4b tumours undergoing SLNB were recruited over a 6-month period at a tertiary referral centre. All underwent standard preoperative lymphoscintigraphy (LSG) using 20-40MBq of Tc99radiolabelled nanocolloid plus intraoperative Patent Blue dye (PBD). ICG was administered as a third tracer agent intraoperatively. Results: 62 patients (33M/29F) were recruited; median age was 61 years. Median melanoma Breslow thickness was 1.6mm. 144 specimens containing 135 SLN were excised. Concordance rate for all 3 tracer agents was 88.1%(119/135 LN); that for radioisotope/PBD was 88.2%(95%CI:82.2,93.7). There were no discordance pairs between radioisotope/PBD compared to radioisotope/PBD/ICG. Radioisotope/ICG significantly increased the sensitivity of detecting SLN to 98.5%(95%CI:94.8,99.8); p<0.00001 compared to radioisotope/PBD. Concordance rate of intraoperative ICG drainage pattern with LSG was 22.6%. Conclusion: ICG utilization showed comparable sensitivity with gold standard. Technical challenges e.g. ICG leakage into biopsy field, poor concordance with LSG limits its efficacy in melanoma SLNB. We therefore do not recommend replacing current practice with ICG alone or by using a combination with TC99

    High-quality genome sequence and description of Paenibacillus dakarensis sp. nov.

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    AbstractStrain FF9T was isolated in Dakar (Senegal) from a blood-culture taken from a 16-month-old child. MALDI-TOF analysis did not allow for identification. After sequencing, strain FF9T exhibited 98.18% similarity with the 16SrRNA sequence of Paenibacillus uliginis. A polyphasic study of phenotypic and genomic analyses showed that strain FF9T is Gram variable, catalase-positive, and presents a genome of 4,569,428 bp (one chromosome but no plasmid) with 4,427genes (4,352 protein-coding and 75 RNA genes (including 3 rRNA operons). The G+C content is 45.7%. On the basis of these genomic and phenotypic data analyses, we propose the creation of Paenibacillus dakarensis strain FF9T

    Performance of the First ANTARES Detector Line

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    In this paper we report on the data recorded with the first Antares detector line. The line was deployed on the 14th of February 2006 and was connected to the readout two weeks later. Environmental data for one and a half years of running are shown. Measurements of atmospheric muons from data taken from selected runs during the first six months of operation are presented. Performance figures in terms of time residuals and angular resolution are given. Finally the angular distribution of atmospheric muons is presented and from this the depth profile of the muon intensity is derived.Comment: 14 pages, 9 figure

    Targeted profiling of human extrachromosomal DNA by CRISPR-CATCH

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    Extrachromosomal DNA (ecDNA) is a common mode of oncogene amplification but is challenging to analyze. Here, we adapt CRISPR-CATCH, in vitro CRISPR-Cas9 treatment and pulsed field gel electrophoresis of agarose-entrapped genomic DNA, previously developed for bacterial chromosome segments, to isolate megabase-sized human ecDNAs. We demonstrate strong enrichment of ecDNA molecules containing EGFR, FGFR2 and MYC from human cancer cells and NRAS ecDNA from human metastatic melanoma with acquired therapeutic resistance. Targeted enrichment of ecDNA versus chromosomal DNA enabled phasing of genetic variants, identified the presence of an EGFRvIII mutation exclusively on ecDNAs and supported an excision model of ecDNA genesis in a glioblastoma model. CRISPR-CATCH followed by nanopore sequencing enabled single-molecule ecDNA methylation profiling and revealed hypomethylation of the EGFR promoter on ecDNAs. We distinguished heterogeneous ecDNA species within the same sample by size and sequence with base-pair resolution and discovered functionally specialized ecDNAs that amplify select enhancers or oncogene-coding sequences

    Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

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    We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

    Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

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    The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

    Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

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    [no abstract available

    Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

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    We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society

    Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

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    Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society
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