Timing of diagnosis of fetal structural abnormalities after the introduction of universal cell-free DNA in the absence of first-trimester anatomical screening

Introduction: Since 2021, first-trimester anatomical screening (FTAS) is offered in the Netherlands alongside genome-wide cell-free DNA (cfDNA). Previously, only second-trimester anatomical screening (STAS) was offered. This study identifies structural abnormalities amenable to first-trimester diagnosis detected at/after STAS in the period following cfDNA implementation and preceding FTAS introduction.Methods: This retrospective cohort includes 547 fetuses referred between 2017 and 2020 because of suspected structural abnormalities before/at/after STAS. Additional prenatal investigations and postnatal follow-up were searched. Abnormalities were classified into "always", "sometimes", and "never" detectable in the first-trimester based on a previously suggested classification.Results: Of the 547 pregnancies, 13 (2.6%) received FTAS and 534 (97.6%) received a dating ultrasound and STAS. In 492/534 (92.1%) anomalies were confirmed; 66 (13.4%) belonged to the "always detectable" group in the first trimester, 303 (61.6%) to the "sometimes detectable", and 123 (25.0%) to the never detectable. Of the "always detectable" anomalies 29/66 (44%) were diagnosed during dating ultrasounds and 37 (56%) during STAS. The rate of termination of pregnancy for anomalies detected during FTAS and at/after STAS was 84.6% (n = 11/13) and 29.3% (n = 144/492) (p &lt; 0.01).Conclusion: When FTAS is not part of screening paradigms, most fetal anomalies remain undetected until the second trimester or later in pregnancy, including 56% of anomalies "always detectable" in the first trimester.</p

Coulomb-nuclear interference in the breakup of 11^{11}Be

Within a theory of breakup reactions formulated in the framework of the post form distorted wave Born approximation, we calculate contributions of the pure Coulomb and the pure nuclear breakup as well as those of their interference terms to a variety of cross sections in breakup reactions of the one-neutron halo nucleus $^{11}$Be on a number of target nuclei. In contrast to the assumption often made, the Coulomb-nuclear interference terms are found to be non-negligible in case of exclusive cross sections of the fragments emitted in this reaction on medium mass and heavy target nuclei. The consideration of the nuclear breakup leads to a better description of such data.Comment: 9 pages, latex, 2 figures, to be published in Phys. Rev. C (Rapid Communication

MOMDIS: a Glauber model computer code for knockout reactions

A computer program is described to calculate momentum distributions in stripping and diffraction dissociation reactions. A Glauber model is used with the scattering wavefunctions calculated in the eikonal approximation. The program is appropriate for knockout reactions at intermediate energy collisions (30 MeV $\leq$ E$_{lab}/$nucleon $\leq 2000$ MeV). It is particularly useful for reactions involving unstable nuclear beams, or exotic nuclei (e.g. neutron-rich nuclei), and studies of single-particle occupancy probabilities (spectroscopic factors) and other related physical observables. Such studies are an essential part of the scientific program of radioactive beam facilities, as in for instance the proposed RIA (Rare Isotope Accelerator) facility in the US.Comment: 22 pages. Accepted for publication in Computer Physics Communications. Code available from CPC web sit

Coulomb-Nuclear Coupling and Interference Effects in the Breakup of Halo Nuclei

Nuclear and Coulomb breakup of halo nuclei have been treated often as incoherent processes and structure information have been extracted from their study. The aim of this paper is to clarify whether interference effects and Coulomb-nuclear couplings are important and how they could modify the simple picture previously used. We calculate the neutron angular and energy distributions by using first order perturbation theory for the Coulomb amplitude and an eikonal approach for the nuclear breakup. This allows for a simple physical interpretation of the results which are mostly analytical. Our formalism includes the effect of the nuclear distortion of the neutron wave function on the Coulomb amplitude. This leads to a Coulomb-nuclear coupling term derived here for the first time which gives a small contribution for light targets but is of the same order of magnitude as nuclear breakup for heavy targets. The overall interference is constructive for light to medium targets and destructive for heavy targets. Thus it appears that Coulomb breakup experiments need to be analyzed with more accurate models than those used so far.Comment: 28 Latex pages, 2 tables, 2 eps figures, 5 ps figures. Accepted for publication in Nucl. Phys.

Single-Proton Removal Reaction Study of 16B

The low-lying level structure of the unbound system $^{16}$B has been investigated via single-proton removal from a 35 MeV/nucleon $^{17}$C beam. The coincident detection of the beam velocity $^{15}$B fragment and neutron allowed the relative energy of the in-flight decay of $^{16}$B to be reconstructed. The resulting spectrum exhibited a narrow peak some 85 keV above threshold. It is argued that this feature corresponds to a very narrow ($\Gamma \ll$100 keV) resonance, or an unresolved multiplet, with a dominant $\pi (p_{3/2})^{-1} \otimes \nu (d_{5/2}^3)_{J=3/2^+}$ + $\pi (p_{3/2})^{-1} \otimes \nu (d_{5/2}^2,s_{1/2})_{J=3/2^+}$ configuration which decays by d-wave neutron emission.Comment: 16 pages, 5 figures, 1 table, submitted to Phys. Lett.

Dynamical description of the breakup of one-neutron halo nuclei 11Be and 19C

We investigate the breakup of the one-neutron halo nuclei 11Be and 19C within a dynamical model of the continuum excitation of the projectile. The time evolution of the projectile in coordinate space is described by solving the three-dimensional time dependent Schroedinger equation, treating the projectile-target (both Coulomb and nuclear) interaction as a time dependent external perturbation. The pure Coulomb breakup dominates the relative energy spectra of the fragments in the peak region, while the nuclear breakup is important at higher relative energies. The coherent sum of the two contributions provides a good overall description of the experimental spectra. Cross sections of the first order perturbation theory are derived as a limit of our dynamical model. The dynamical effects are found to be of the order of 10-15% for the beam energies in the range of 60 - 80 MeV/nucleon. A comparison of our results with those of a post form distorted wave Born approximation shows that the magnitudes of the higher order effects are dependent on the theoretical model.Comment: 15 pages, ReVTeX, 5 figures, typos corrected, accepted for publication in Physical Review

Elastic scattering and breakup of 17^F at 10 MeV/nucleon

Angular distributions of fluorine and oxygen produced from 170 MeV 17^F incident on 208^Pb were measured. The elastic scattering data are in good agreement with optical model calculations using a double-folding potential and parameters similar to those obtained from 16^O+208^Pb. A large yield of oxygen was observed near \theta_lab=36 deg. It is reproduced fairly well by a calculation of the (17^F,16^O) breakup, which is dominated by one-proton stripping reactions. The discrepancy between our previous coincidence measurement and theoretical predictions was resolved by including core absorption in the present calculation.Comment: 9 pages, 5 figure

Genetic instability from a single S phase after whole-genome duplication

Diploid and stable karyotypes are associated with health and fitness in animals. By contrast, whole-genome duplications—doublings of the entire complement of chromosomes—are linked to genetic instability and frequently found in human cancers(1–3). It has been established that whole-genome duplications fuel chromosome instability through abnormal mitosis(4–8); however, the immediate consequences of tetraploidy in the first interphase are not known. This is a key question because single whole-genome duplication events such as cytokinesis failure can promote tumorigenesis(9). Here we find that human cells undergo high rates of DNA damage during DNA replication in the first S phase following induction of tetraploidy. Using DNA combing and single-cell sequencing, we show that DNA replication dynamics is perturbed, generating under- and over-replicated regions. Mechanistically, we find that these defects result from a shortage of proteins during the G1/S transition, which impairs the fidelity of DNA replication. This work shows that within a single interphase, unscheduled tetraploid cells can acquire highly abnormal karyotypes. These findings provide an explanation for the genetic instability landscape that favours tumorigenesis after tetraploidization