117 research outputs found
Influence of nuclear physics inputs and astrophysical conditions on Th/U chronometer
The productions of thorium and uranium are key ingredients in -process
nucleo-cosmochronology. With the combination of improved nuclear and stellar
data, we have made detailed investigations on the -process abundance pattern
in the very metal-poor halo stars based on the classical -process approach.
It is found that the results are almost independent of specified simulations to
observed abundances. The influence from nuclear mass uncertainties on Th/U
chronometer can approach 2 Gyr. Moreover, the ages of the metal-poor stars HE
1523-0901, CS 31082-001, and BD +173248 are determined as , , and Gyr, respectively. The results can
serve as an independent check for age estimate of the universe.Comment: 20 pages, 5 figures. accepted by Phys. Rev.
Feasibility of the finite amplitude method in covariant density functional theory
Self-consistent relativistic random-phase approximation (RPA) in the radial
coordinate representation is established by using the finite amplitude method
(FAM). Taking the isoscalar giant monopole resonance in spherical nuclei as
example, the feasibility of the FAM for the covariant density functionals is
demonstrated, and the newly developed methods are verified by the conventional
RPA calculations. In the present relativistic RPA calculations, the effects of
the Dirac sea can be automatically taken into account in the coordinate-space
representation. The rearrangement terms due to the density-dependent couplings
can be implicitly calculated without extra computational costs in both
iterative and matrix FAM schemes.Comment: 12 pages, 5 figure
Finite-amplitude method: An extension to the covariant density functionals
The finite-amplitude method (FAM) is one of the most promising methods for
optimizing the computational performance of the random-phase approximation
(RPA) calculations in deformed nuclei. In this report, we will mainly focus on
our recent progress in the self-consistent relativistic RPA established by
using the FAM. It is found that the effects of Dirac sea can be taken into
account implicitly in the coordinate-space representation and the rearrangement
terms due to the density-dependent couplings can be treated without extra
computational costs.Comment: 5 pages, 2 figures, Proceedings of the 20th Nuclear Physics Workshop
"Marie & Pierre Curie", Kazimierz, Poland, 25-29 September, 201
Nuclear mass table in deformed relativistic Hartree-Bogoliubov theory in continuum, II: Even- nuclei
The mass table in the deformed relativistic Hartree-Bogoliubov theory in
continuum (DRHBc) with the PC-PK1 density functional has been established for
even- nuclei with , extended from the previous work for
even-even nuclei [Zhang (DRHBc Mass Table Collaboration), At.
Data Nucl. Data Tables 144, 101488 (2022)]. The calculated binding energies,
two-nucleon and one-neutron separation energies, root-mean-square (rms) radii
of neutron, proton, matter, and charge distributions, quadrupole deformations,
and neutron and proton Fermi surfaces are tabulated and compared with available
experimental data. A total of 4829 even- nuclei are predicted to be bound,
with an rms deviation of 1.477 MeV from the 1244 mass data. Good agreement with
the available experimental odd-even mass differences, decay energies,
and charge radii is also achieved. The description accuracy for nuclear masses
and nucleon separation energies as well as the prediction for drip lines is
compared with the results obtained from other relativistic and nonrelativistic
density functional. The comparison shows that the DRHBc theory with PC-PK1
provides an excellent microscopic description for the masses of even-
nuclei. The systematics of the nucleon separation energies, odd-even mass
differences, pairing energies, two-nucleon gaps, decay energies, rms
radii, quadrupole deformations, potential energy curves, neutron density
distributions, and neutron mean-field potentials are discussed.Comment: 394 pages, 17 figures, 2 tables, published in Atomic Data and Nuclear
Data Tables, data file in the TXT form is available for download under
"Ancillary files
Sex differences in oncogenic mutational processes.
Sex differences have been observed in multiple facets of cancer epidemiology, treatment and biology, and in most cancers outside the sex organs. Efforts to link these clinical differences to specific molecular features have focused on somatic mutations within the coding regions of the genome. Here we report a pan-cancer analysis of sex differences in whole genomes of 1983 tumours of 28 subtypes as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We both confirm the results of exome studies, and also uncover previously undescribed sex differences. These include sex-biases in coding and non-coding cancer drivers, mutation prevalence and strikingly, in mutational signatures related to underlying mutational processes. These results underline the pervasiveness of molecular sex differences and strengthen the call for increased consideration of sex in molecular cancer research
Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke
Importance
It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy.
Objective
To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO.
Design, Setting, and Participants
This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023.InterventionsEligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy.
Main Outcomes and Measures
The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours.
Results
Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo.
Conclusions and Relevance
Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability.Trial RegistrationChiCTR.org.cn Identifier: ChiCTR210005172
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
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