The evolution of Rayleigh–Taylor instability (RTI) for weakly compressible fluids was numerically simulated using the smooth particle hydrodynamics method. It was found that the speed of spikes and ...bubbles in most cases will reach a stable value, which is called terminal speed. The calculated terminal speed of the bubble was found to be systematically higher than the theoretical model based on the potential flow hypothesis. This deviation could be modified by including the vortex effect on the terminal speed of the bubble. A significant correlation between the bubble speed and the vorticity in the bubble head was found during the whole evolution of RTI. The analysis of the vortex dynamics in the bubble head region during the terminal speed stage shows that there is a balance between the baroclinic production, viscous dissipation, and convective transport of the vorticity.
In inertial confinement fusion, quantitative and high-spatial resolution (Formula: see textm) measurements of the X-rays self-emitted by the hotspot are critical for studying the physical processes ...of the implosion stagnation stage. Herein, the 8 ± 0.39-keV monochromatic X-ray distribution from the entire hotspot is quantitatively observed in 5-Formula: see textm spatial resolution using a Kirkpatrick-Baez microscope, with impacts from the responses of the diagnosis system removed, for the first time, in implosion experiments at the 100 kJ laser facility in China. Two-dimensional calculations along with 2.5% P2 drive asymmetry and 0.3 ablator self-emission are congruent with the experimental results, especially for the photon number distribution, hotspot profile, and neutron yield. Theoretical calculations enabled a better understanding of the experimental results. Furthermore, the origins of the 17.81% contour profile of the deuterium-deuterium hotspot and the accurate Gaussian source approximation of the core emission area in the implosion capsule are clarified in detail. This work is significant for quantitatively exploring the physical conditions of the hotspot and updating the theoretical model of capsule implosion.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Background
Recurrent pregnancy loss (RPL) refers to two or more consecutive spontaneous abortion before 24 weeks of gestation, representing 1% of couples of childbearing age. Epigenetic factors ...including dysregulation of DNA methylation of some genes may play a role in RPL.
Objective
To identify RPL related genes modulated by DNA methylation expressed in decidua and blood.
Methods
Three decidua samples each from RPL patients and normal controls were recruited to perform genome-wide bisulfite sequencing (GWBS) and transcriptome sequencing. Based on the above results, 22.52 kb of differential methylation regions (DMRs) from 17 genes were verified by bisulfite sequencing PCR at specific region (Hi-MethylSeq) in another 15 decidua (7RPL vs. 8 Controls) and 13 blood (5RPL vs. 8 Controls) samples.
Results
23 genes showed significantly differential cytosine methylation status and distinct expression level between PRL patients and healthy controls synergistically. Three signaling pathways were found to be shared between genes with both hypomethylated differential methylation regions (DMR) and upregulated differential gene expression (DGE). The results from Hi-MethylSeq showed that the hypermethylation of SGK1 in both blood and decidua samples in RPL patients, which was consistent to its lower expression in endometrium reported earlier. SGK3 and CREB5 also showed modulated methylation level in RPL decidua.
Conclusion
Our finding supported that aberrant methylation of SGK1 and CREB5 could be a cause of the dysregulation of these gens in the endometrium, which is one of cause of reproductive failure. The function of SGK3 in reproduction system deserves further investigation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•First cohort study in China to investigate long-term ambient O3 exposure and CVD.•MDA8 O3 may increase the risk of total CVD, heart disease and hypertension.•Effects of MDA8 O3 were ...greater in males, urban areas, and Southern China.•We also provided the PAFs of CVD attributable to MDA8 O3.•This study extended our understanding of chronic health effects of ambient O3.
The health effects of ambient ozone have been investigated in many previous studies. However, the effects of long-term exposure to ambient ozone on the incidence of cardiovascular disease (CVD) remain inconclusive.
To estimate the associations of long-term exposure to maximum daily 8-hours average ozone (MDA8 O3) with the incidence of total CVD, heart disease, hypertension, and stroke.
This was a prospective cohort study, and the data was obtained from the China Health and Retirement Longitudinal Survey (CHARLS) implemented during 2011–2018 and the China Family Panel Studies (CFPS) implemented during 2010–2018. We applied a Cox proportional hazards regression model to evaluate the associations of MDA8 O3 with total CVD, heart disease, hypertension, and stroke risks, and the corresponding population-attributable fractions (PAF) attributable to MDA8 O3 were also calculated. All analyses were conducted by R software.
The mean MDA8 O3 concertation of all included participants in the CHARLS and CFPS were 51.03 part per billion (ppb) and 51.15 ppb, respectively. In the CHARLS including 18,177 participants, each 10 ppb increment in MDA8 O3 concentration was associated with a 31% increase hazard ratio (HR) = 1.31, 95% confidence interval (CI): 1.22–1.42 in the risk of incident heart disease, and the corresponding population-attributable fractions (PAF) was 13.79% 10.12%-17.32%. In the CFPS including 30,226 participants, each 10 ppb increment in MDA8 O3 concentration was associated with an increase in the risk of incident total CVD (1.07 1.02–1.13), and hypertension (1.10 1.03–1.18). The PAFs of total CVD, and hypertension attributable to MDA8 O3 were 3.53% 0.82%-6.16%, and 5.11% 1.73%-8.38%, respectively. Stratified analyses showed greater associations in males, urban areas, and Southern China.
Long-term exposure to MDA8 O3 may increase the incidence of CVD. Therefore, the policies that control O3 and related precursors are persistently needed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We present the first integrated implosion experiments which were carried out on the SG-III Laser facility in 2015. Vacuum hohlraums and squared laser pulses were used in the experiments. The purpose ...of the experiments was to demonstrate the one-dimensional implosion performance at low-convergence ratios. To characterize the implosion performance, the hohlraum energetics, the implosion dynamics and the nuclear products were measured. In particular, the radiation flux was diagnosed through laser entrance hole at different angles by an array of flat response detectors, and the energy and the spectrum of the back-scattered lasers were monitored for 8 laser beams which correspond to 2 beams in each cone at the lower hemisphere. Moreover, the hotspot shape was imaged using KB microscopes of high spatial resolution simultaneously from the equator and polar views. Taking advantage of the high resolution, some detailed structures in the hotspots were noticed. For the best implosion performances, the neutron yields over 1D calculation reached 50% at the convergence-ratios of 15.
Abstract
Background
The effects of COVID-19 lockdown measures on maternal and fetal health remain unclear. We examined the associations of COVID-19 lockdown with gestational length and preterm birth ...(PTB) in a Chinese population.
Methods
We obtained medical records of 595,396 singleton live infants born between 2015 and 2020 in 5 cities in Guangdong Province, South China. The exposed group (
N
= 101,900) included women who experienced the COVID-19 Level I lockdown (1/23–2/24/2020) during pregnancy, while the unexposed group (
N
= 493,496) included women who were pregnant during the same calendar months in 2015–2019. Cumulative exposure was calculated based on days exposed to different levels of emergency responses with different weighting. Generalized linear regression models were applied to estimate the associations of lockdown exposure with gestational length and risk of PTB (< 37 weeks).
Results
The exposed group had a shorter mean gestational length than the unexposed group (38.66 vs 38.74 weeks: adjusted β = − 0.06 week 95%CI, − 0.07, − 0.05 week). The exposed group also had a higher risk of PTB (5.7% vs 5.3%; adjusted OR = 1.08 95%CI, 1.05, 1.11). These associations seemed to be stronger when exposure occurred before or during the 23rd gestational week (GW) than during or after the 24th GW. Similarly, higher cumulative lockdown exposure was associated with a shorter gestational length and a higher risk of PTB.
Conclusions
The COVID-19 lockdown measures were associated with a slightly shorter gestational length and a moderately higher risk of PTB. Early and middle pregnancy periods may be a more susceptible exposure window.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Individual metal levels are potential risk factors for the development of preeclampsia (PE). However, understanding of relationship between multiple metals and PE remains elusive.
The purpose of this ...study was to explore whether eight metals zinc (Zn), manganese (Mn), copper (Cu), nickel (Ni), lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) in serum had a certain relationship with PE.
A study was conducted in Dongguan, China. The concentrations of metals in maternal serum were assessed using inductively coupled plasma mass spectrometry (ICP-MS). Data on various factors were collected through a face-to-face interview and hospital electronic medical records. The unconditional logistic regression model, principal component analysis (PCA) and Bayesian Kernel Machine Regression (BKMR) were applied in our study.
The logistic regression model revealed that the elevated levels of Cu, Pb, and Hg were associated with an increased risk of PE. According to PCA, principal component 1 (PC1) was predominated by Hg, Pb, Mn, Ni, Cu, and As, and PC1 was associated with an increased risk of PE, while PC2 was predominated by Cd and Zn. The results of BKMR indicated a significant positive cumulative effect of serum metals on PE risk, with Ni and Cu exhibiting a significant positive effect. Moreover, BKMR results also revealed the nonlinear effects of Ni and Cd.
The investigation suggests a potential positive cumulative impact of serum metals on the occurrence of PE, with a particular emphasis on Cu as a potential risk factor for the onset and exacerbation of PE. These findings offer valuable insights for guiding future studies on this concern.
During the special period of the global spread of COVID-19, pregnant women are sensitive groups to the impacts of COVID-19 epidemic. However, the effects of lockdown measures implemented in response ...to the COVID-19 on fetal birthweight remain unclear.
This study investigated the associations of COVID-19 lockdown with birth weight in Chinese population.
We collected 730,153 data of participants from hospitals of five cities in the south of China, we defined the time period of level I response (1/23-2/24/2020) as level I lockdown, and women who were pregnant during level I lockdown as the exposure group. Women who were pregnant during the same calendar month from 2015 to 2019 were defined as the unexposed group. We quantitatively estimate the individual cumulative exposure dose by giving different weights to days with different emergency response levels. Generalized linear regression models were used to estimate the association between COVID-19 lockdown exposure with birth weight and risk of low birth weight (<2,500 g) and macrosomia (>4,000 g).
The birth weight of the exposed group is heavier than the unexposed group (3,238.52 vs. 3,224.11 g: adjusted
= 24.39 g 95% CI: 21.88, 26.91 g). The exposed group had a higher risk of macrosomia (2.8% vs. 2.6%; adjusted OR = 1.17 95% CI: 1.12, 1.22). More obvious associations were found between COVID-19 lockdown and macrosomia in women who experienced the lockdown in their early pregnancy. Women who experienced the lockdown at their 4-7 weeks of pregnancy showed statistically significant heavier birth weight than unexposed group (after adjustment):
= 1.28 (95% CI: 1.11, 1.46) g. We also observed a positive association between cumulative exposure dose of COVID-19 lockdown in all pregnant women and birth weight, after divided into four groups,
1:
= 32.95 (95% CI: 28.16, 37.75) g;
2:
= 18.88 (95% CI: 14.12, 23.64) g;
3:
= 19.50 (95% CI: 14.73, 24.28) g;
4:
= 21.82 (95% CI: 17.08, 26.56) g. However, there was no statistically significant difference in the risk of low birth weight between exposed and unexposed groups.
The COVID-19 lockdown measures were associated with a heavier birth weight and a higher risk of macrosomia. Early pregnancy periods may be a more susceptible exposure window for a heavier birth weight and a higher risk of macrosomia. We also observed a positive association between cumulative exposure dose of COVID-19 lockdown and birth weight. The government and health institutions should pay attention to the long-term health of the infants born during the COVID-19 lockdown period, and follow up these mothers and infants is necessary.
The ongoing pandemic of COVID-19 is still affecting our life, but the effects of lockdown measures on gestational diabetes mellitus (GDM) in pregnant women remain unclear.
To investigate the ...association between COVID-19 lockdown and GDM.
Medical records of 140844 pregnant women during 2015-2020 were extracted from 5 hospitals in Guangdong Province, China. Pregnant women who underwent the COVID-19 Level I lockdown (1/23 - 2/24/2020) during pregnancy were defined as the exposed group (N=20472) and pregnant women who underwent the same calendar months during 2015-2019 (1/23 - 2/24) were defined as the unexposed group (N=120372). Subgroup analyses were used to explore the potential susceptible exposure window of COVID-19 lockdown on GDM. Cumulative exposure is quantitatively estimated by assigning different weights to response periods with different exposure intensities. A logistic regression model was used to estimate the association between COVID-19 lockdown exposure and GDM.
The rates of GDM in the exposed and unexposed groups were 15.2% and 12.4%, respectively. The overall analyses showed positive associations (odds ratio, OR=1.22, 95%CI: 1.17, 1.27) between lockdown exposure and GDM risk in all pregnant women. More pronounced associations were found in women who underwent the COVID-19 lockdown in their first four months of pregnancy, and the adjusted OR values ranged from 1.24 (95%CI: 1.10, 1.39) in women with 5-8 gestational weeks (GWs) to 1.35 (95%CI: 1.20, 1.52) with < 5 GWs. In addition, we found a positive exposure-response association of cumulative lockdown exposure with the risk of GDM.
The COVID-19 lockdown was associated with an increased risk of GDM, and the first four months of pregnancy may be the window for sensitive exposure.
The evolution of ablative Rayleigh–Taylor instability (ARTI) induced by single-mode stationary and time-varying perturbations in heat flux is studied numerically in two dimensions. Compared with the ...stationary case, time-varying heat-flux perturbation mitigates ARTI growth because of the enhanced thermal smoothing induced by the wave-like traveling heat flux. A resonance is found to form when the phase velocity of the heat-flux perturbation matches the average sound speed in the ablation region. In the resonant regime, the coherent density and temperature fluctuations enhance the electron thermal conduction in the ablation region and lead to larger ablation pressure and effective acceleration, which consequently yield higher linear growth rate and saturated bubble velocity. The enhanced effective acceleration offers increased implosion velocity but can also compromise the integrity of inertial confinement fusion shells by causing faster ARTI growth.
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