3,369 research outputs found

    Phase-Resolved Timing Analysis of GRS 1915+105 in Its {\rho} State

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    We made a phase-resolved timing analysis of GRS 1915+105 in its {\rho} state and obtained detailed {\rho} cycle evolutions of the frequency, the amplitude and the coherence of low-frequency quasi-periodic oscillation (LFQPO). We combined our timing results with the spectral study by Neilsen et al. to perform an elaborate comparison analysis. Our analyses show that the LFQPO frequency does not scale with the inner disk radius, but it is related to the spectral index, indicating a possible correlation between the LFQPOs and the corona. The LFQPO amplitude spectrum and other results are naturally explained by tying the LFQPO to the corona. The similarities of the spectra of variability parameters between the LFQPO from {\rho} state and those from more steady states indicate that the LFQPOs of GRS 1915+105 in very different states seem to share the same origin.Comment: 21 pages, 4 figures, accepted for publication in Ap

    Large-deviation analysis for counting statistics in mesoscopic transports

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    We present an efficient approach, based on a number-conditioned master equation, for large-deviation analysis in mesoscopic transports. Beyond the conventional full-counting-statistics study, the large-deviation approach encodes complete information of both the typical trajectories and the rare ones, in terms of revealing a continuous change of the dynamical phase in trajectory space. The approach is illustrated with two examples: (i) transport through a single quantum dot, where we reveal the inhomogeneous distribution of trajectories in general case and find a particular scale invariance point in trajectory statistics; and (ii) transport through a double dots, where we find a dynamical phase transition between two distinct phases induced by the Coulomb correlation and quantum interference.Comment: 8 pages, 3 figure

    Insights into the Ecological Roles and Evolution of Methyl-Coenzyme M Reductase-Containing Hot Spring Archaea

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    Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor

    Phase I Trial of Escalating-dose Cisplatin with 5-fluorouracil and Concurrent Radiotherapy in Chinese Patients with Esophageal Cancer

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    We defined the maximum-tolerated dose (MTD) of chemoradiotherapy (cisplatin (CDDP) with 5-fluorouracil (5-FU) and concurrent chemoradiotherapy) for Chinese patients with esophageal cancer. Twenty-one previously untreated patients with primary esophageal cancer were entered into this study. Escalating doses of CDDP with 5-FU were administered in a modified Fibonacci sequence, with concurrent conventional fractionation radiotherapy (CFR) of 60 Gy or 50 Gy. The starting doses were CDDP 37.5 mg/m2 on day 1, and 5-FU 500 mg/m2 on days 1-5, respectively. The regimen was repeated 4 times every 28 days. If no dose-limiting toxicity (DLT) was observed, the next dose level was applied. The procedures were repeated until DLT appeared. The MTD was declared to be 1 dose level below the level at which DLT appeared. DLT was grade 3 radiation-induced esophagitis at a dose level of CDDP 60 mg/m2 with 5-FU 700 mg/m2 and concurrent 60 Gy CFR. MTD was defined as CDDP 52.5 mg/m2 with 5-FU 700 mg/m2 and concurrent 50 Gy CFR. The MTD of CDDP with 5-FU and in concurrent chemoradiotherapy for Chinese patients with esophageal cancer is CDDP 52.5 mg/m2 on day 1 and 5FU 700 mg/m2 on days 1-5, repeated 4 times every 28 days, and concurrent 50 Gy CFR. Further evaluation of this regimen in a prospective phase II trial is ongoing.</p
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