We present results of a supernova light-curve population synthesis, predicting the range of possible supernova lightcurves arising from a population of progenitor stars that include interacting binary systems. We show that the known diversity of supernova lightcurves can be interpreted as arising from binary interactions. Given detailed models of the progenitor stars, we are able to the determine what parameters within these stars determine the shape of their supernova lightcurve. The primary factors are the mass of supernova ejecta and the mass of hydrogen in the final progenitor. We find that there is a continuum of light-curve behaviour from type IIP, IIL to IIb supernovae related to the range of hydrogen and ejecta masses. Most type IIb supernovae arise from a relatively narrow range of initial masses from 10 to 15 M⊙. We also find a few distinct lightcurves that are the result of stellar mergers.
We use the results of a supernova light-curve population synthesis to predict the range of possible supernova light curves arising from a population of single-star progenitors that lead to type IIP supernovae. We calculate multiple models varying the initial mass, explosion energy, nickel mass and nickel mixing and then compare these to type IIP supernovae with detailed light curve data and pre-explosion imaging progenitor constraints. Where a good fit is obtained to observations, we are able to achieve initial progenitor and nickel mass estimates from the supernova lightcurve that are comparable in precision to those obtained from progenitor imaging. For two of the eleven IIP supernovae considered our fits are poor, indicating that more progenitor models should be included in our synthesis or that our assumptions, regarding factors such as stellar mass loss rates or the rapid final stages of stellar evolution, may need to be revisited in certain cases. Using the results of our analysis we are able to show that most of the type IIP supernovae have an explosion energy of the order of log(Eexp/ergs)=50.52±0.10 and that both the amount of nickel in the supernovae and the amount of mixing may have a dependence on initial progenitor mass.
BACKGROUND: Pregnancy-related cardiovascular physiologic changes increase the likelihood of pulmonary edema, with the risk of fluid extravasating into the pulmonary interstitium being potentially at a maximum during the early postpartum period. Data on the impact of labor and peripartum hemodynamic strain on lung ultrasound (LUS) are limited, and the prevalence of subclinical pulmonary interstitial syndrome in peripartum women is poorly described. The primary aim of this exploratory study was to estimate the prevalence of pulmonary interstitial syndrome in healthy term parturients undergoing vaginal (VD), elective (eCD), and unplanned intrapartum cesarean deliveries (uCD). Secondary aims were to estimate the prevalence of positive lung regions (≥3 B-lines on LUS per region) and to assess the associations between positive lung regions and possible contributing factors. METHODS: In this prospective observational cohort study, healthy women at term undergoing VD, eCD, or uCD were enrolled. Following international consensus recommendations, a LUS examination was performed within 4 hours after delivery applying an 8-region technique. Pulmonary interstitial syndrome was defined by the presence of 2 or more positive lung regions per hemithorax. Ultrasound studies were reviewed by 2 blinded reviewers and assessed for interobserver reliability. RESULTS: Seventy-five women were assessed (n = 25 per group). No pulmonary interstitial syndrome was found in the VD and eCD groups (each 0 of 25; 0%, 95% confidence interval [CI], 0-13.7). Pulmonary interstitial syndrome was found in 2 of 25 (8%, 95% CI, 1-26) women undergoing an uCD (P = .490 for VD versus uCD and P = .490 for eCD versus uCD). In 1 woman, this correlated clinically with the development of pulmonary edema. One or more positive lung regions were present in 5 of 25 (20%), 6 of 25 (24%), and 11 of 25 (44%) parturients following VD, eCD, and uCD, respectively (P = .136). Positive lung regions were predominantly found in lateral lung regions. The number of positive lung regions showed a weak correlation with patient age (r = 0.25, 95% CI, 0.05-0.47; P = .033). No significant association was found between LUS pattern and parity, duration of labor, labor augmentation, labor induction, estimated total intravenous fluid intake, or net intravenous fluid intake. CONCLUSIONS: Although many focal areas of increased extravascular lung water (20%–44% prevalence) can be identified on LUS, the overall prevalence of pulmonary interstitial syndrome was 2.7% (2 of 75; 95% CI, 0.3-9.3) among healthy term parturients soon after delivery. Focal areas of positive lung water regions were weakly correlated with maternal age.
Background Some ultrasonic soft markers can be found during ultrasound examination. However, the etiology of the fetuses with ultrasonic soft markers is still unknown. This study aimed to evaluate the genetic etiology and clinical value of chromosomal abnormalities and copy number variations (CNVs) in fetuses with ultrasonic soft markers. Methods Among 1131 fetuses, 729 had single ultrasonic soft marker, 322 had two ultrasonic soft markers, and 80 had three or more ultrasonic soft markers. All fetuses underwent conventional karyotyping, followed by single nucleotide polymorphism (SNP) array analysis. Results Among 1131 fetuses with ultrasonic soft markers, 46 had chromosomal abnormalities. In addition to the 46 fetuses with chromosomal abnormalities consistent with the results of the karyotyping analysis, the SNP array identified additional 6.1% (69/1131) abnormal CNVs. The rate of abnormal CNVs in fetuses with ultrasonic soft marker, two ultrasonic soft markers, three or more ultrasonic soft markers were 6.2%, 6.2%, and 5.0%, respectively. No significant difference was found in the rate of abnormal CNVs among the groups. Conclusions Genetic abnormalities affect obstetrical outcomes. The SNP array can fully complement conventional karyotyping in fetuses with ultrasonic soft markers, improve detection rate of chromosomal abnormalities, and affect pregnancy outcomes.
Pallister‐Killian syndrome (PKS) is a rare sporadic genetic disorder usually caused by mosaicism of an extra isochromosome of 12p (i(12p)). This retrospective study analysed the prenatal ultrasound manifestations and molecular and cytogenetic results of five PKS foetuses. Samples of amniotic fluid and/or cord blood, skin biopsy and placenta were collected. Conventional karyotyping and single nucleotide polymorphism array (SNP array) were performed on all the amniotic fluid or cord blood samples. Copy number variants sequencing (CNV‐seq) and fluorescence in situ hybridization (FISH) were also used for the validation for one foetus. All the five foetuses were from pregnancies with advanced parental age. Two foetuses involved structural abnormalities and one foetus had only soft markers, all of which included increased nuchal translucency. The rest two foetuses had normal ultrasounds in the second trimester, which has rarely been reported before. The karyotype revealed typical i(12p) in four cases and a small supernumerary marker chromosome consisting of 12p and 20p in the remaining one case. The proportion of cells with i(12p) ranged from 0 to 100% in cultural cells, while SNP array results suggested 2−4 copies of 12p. For one foetus, metaphase FISH showed normal results, but the interphase FISH suggested cell lines with two, three and four copies of 12p in the amniotic fluid. Advanced parental age may be an important risk factor for PKS, and there were no typical ultrasound manifestations related to PKS. A combination of karyotype analysis and molecular diagnosis is an effective method for the diagnosis of PKS.
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