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Aging plays a crucial role in the mechanisms of the impacts of genetic and environmental factors on blood pressure and serum lipids. However, to our knowledge, how the influence of genetic and environmental factors on the correlation between blood pressure and serum lipids changes with age remains to be determined. In this study, data from the Chinese National Twin Registry (CNTR) were used. Resting blood pressure, including systolic and diastolic blood pressure (SBP and DBP), and fasting serum lipids, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TGs) were measured in 2378 participants (1189 twin pairs). Univariate and bivariate structural equation models examined the genetic and environmental influences on blood pressure and serum lipids among three age groups. All phenotypes showed moderate to high heritability (0.37–0.59) and moderate unique environmental variance (0.30–0.44). The heritability of all phenotypes showed a decreasing trend with age. Among all phenotypes, SBP and DBP showed a significant monotonic decreasing trend. For phenotype-phenotype pairs, the phenotypic correlation (Rph) of each pair ranged from −0.04 to 0.23, and the additive genetic correlation (Ra) ranged from 0.00 to 0.36. For TC&SBP, TC&DBP, TG&SBP and TGs&DBP, both the Rph and Ra declined with age, and the Ra difference between the young group and the older adult group is statistically significant (p < .05). The unique environmental correlation (Re) of each pair did not follow any pattern with age and remained relatively stable with age. In summary, we observed that the heritability of blood pressure was affected by age. Moreover, blood pressure and serum lipids shared common genetic backgrounds, and age had an impact on the phenotypic correlation and genetic correlations.
It is crucial to understand the genetic mechanisms and biological pathways underlying the relationship between obesity and serum lipid levels. Structural equation models (SEMs) were constructed to calculate heritability for body mass index (BMI), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and the genetic connections between BMI and the four classes of lipids using 1197 pairs of twins from the Chinese National Twin Registry (CNTR). Bivariate genomewide association studies (GWAS) were performed to identify genetic variants associated with BMI and lipids using the records of 457 individuals, and the results were further validated in 289 individuals. The genetic background affecting BMI may differ by gender, and the heritability of males and females was 71% (95% CI [.66, .75]) and 39% (95% CI [.15, .71]) respectively. BMI was positively correlated with TC, TG and LDL-C in phenotypic and genetic correlation, while negatively correlated with HDL-C. There were gender differences in the correlation between BMI and lipids. Bivariate GWAS analysis and validation stage found 7 genes (LOC105378740, LINC02506, CSMD1, MELK, FAM81A, ERAL1 and MIR144) that were possibly related to BMI and lipid levels. The significant biological pathways were the regulation of cholesterol reverse transport and the regulation of high-density lipoprotein particle clearance (p < .001). BMI and blood lipid levels were affected by genetic factors, and they were genetically correlated. There might be gender differences in their genetic correlation. Bivariate GWAS analysis found MIR144 gene and its related biological pathways may influence obesity and lipid levels.
A pulsed fast neutron source is critical for applications of fast neutron resonance radiography and fast neutron absorption spectroscopy. However, due to the large transversal source size (of the order of mm) and long pulse duration (of the order of ns) of traditional pulsed fast neutron sources, it is difficult to realize high-contrast neutron imaging with high spatial resolution and a fine absorption spectrum. Here, we experimentally present a micro-size ultra-short pulsed neutron source by a table-top laser–plasma wakefield electron accelerator driving a photofission reaction in a thin metal converter. A fast neutron source with source size of approximately 500 μm and duration of approximately 36 ps has been driven by a tens of MeV, collimated, micro-size electron beam via a hundred TW laser facility. This micro-size ultra-short pulsed neutron source has the potential to improve the energy resolution of a fast neutron absorption spectrum dozens of times to, for example, approximately 100 eV at 1.65 MeV, which could be of benefit for high-quality fast neutron imaging and deep understanding of the theoretical model of neutron physics.
The aim of the present study was to compare the rate of preterm birth (PTB) and growth from birth to 18 years between twins conceived by in vitro fertilization (IVF) and twins conceived by spontaneous conception (SC) in mainland China. The retrospective cohort study included 1164 twins resulting from IVF and 25,654 twins conceived spontaneously, of which 494 from IVF and 6338 from SC were opposite-sex twins. PTB and low birth weight (LBW), and growth, including length/height and weight, were compared between the two groups at five stages: infancy (0 year), toddler period (1–2 years), preschool (3–5 years), primary or elementary school (6–11 years), and adolescence (10–18 years). Few statistically significant differences were found for LBW and growth between the two groups after adjusting for PTB and other confounders. Twins born by IVF faced an increased risk of PTB compared with those born by SC (adjusted odds ratio [aOR] 8.21, 95% confidence interval [CI] [3.19, 21.13], p < .001 in all twins and aOR 10.12, 95% CI [2.32, 44.04], p = .002 in opposite-sex twins). Twins born by IVF experienced a similar growth at five stages (0–18 years old) when compared with those born by SC. PTB risk, however, is significantly higher for twins conceived by IVF than those conceived by SC.
The objective of this study was to investigate how different obesity measures link to circulating metabolites, and whether the connections are due to genetic or environmental factors. A cross-sectional analysis was performed on follow-up survey data at the Chinese National Twin Registry (CNTR), which was conducted in four areas of China (Shandong, Jiangsu, Zhejiang and Sichuan) in 2013. The survey collected detailed questionnaire information and conducted physical examinations, fasting blood sampling and untargeted metabolomic measurements among 439 adult twins. Linear regression models and bioinformatics analysis were used to examine the relation of obesity measures, including body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) with serum metabolite levels and related pathways. A co-twin control study was additionally conducted among 15 obesity-discordant monozygotic (MZ) pairs (intrapair BMI difference >3 kg/m2) to examine any differences in metabolites controlling for genetic factors. Eleven metabolites were associated with BMI, WC and WHR after controlling for genetic and shared environmental factors. Pathway analysis identified pathways such as phenylalanine metabolism, purine metabolism, valine, leucine and isoleucine biosynthesis that were associated with obesity. A wide range of unfavorable alterations in the serum metabolome was associated with obesity. Obesity-discordant twin analysis suggests that these associations are independent of genetic liability.
We demonstrate an all-optical method for controlling the transverse motion of an ionization injected electron beam in a laser plasma accelerator by using the transversely asymmetrical plasma wakefield. The laser focus shape can control the distribution of a transversal wakefield. When the laser focus shape is changed from circular to slanted elliptical in the experiment, the electron beam profiles change from an ellipse to three typical shapes. The three-dimensional particle-in-cell simulation result agrees well with the experiment, and it shows that the trajectories of these accelerated electrons change from undulating to helical. Such an all-optical method could be useful for convenient control of the transverse motion of an electron beam, which results in synchrotron radiation from orbit angular momentum.
Mutation in CFAP43 leads to severe asthenozoospermia and multiple morphological abnormalities of the sperm flagellum (MMAF) in both human and mouse. Previous studies have shown that disruption of intra-manchette transport (IMT) caused failure of flagellum assembly and sperm head shaping. In a previous study, therefore, we postulated that disruption of IMT may contribute to the failure of sperm flagellum formation and result in MMAF, however the mechanisms underlying these defects are still poorly understood. Cfap43-deficient mice were studied here to reveal the cellular mechanisms of abnormal sperm head morphology and MMAF. Depletion of Cfap43 led to abnormal spermiogenesis and caused MMAF, sperm head abnormality and oligozoospermia. Furthermore, both abnormal manchette and disorganized ectoplasmic specialization (ES) could be observed at the elongated spermatids in Cfap43-deficient mice. Therefore, our findings demonstrated that, in mice, CFAP43-mediated IMT is essential for sperm head shaping and sperm flagellum formation.
The Chinese National Twin Registry (CNTR), initiated in 2001, has now become the largest twin registry in Asia. From 2015 to 2018, the CNTR continued to receive Chinese government funding and had recruited 61,566 twin-pairs by 2019 to study twins discordant for specific exposures such as environmental factors, and twins discordant for disease outcomes or measures of morbidity. Omic data, including genetics, genomics, metabolomics, and proteomics, and gut microbiome will be tested. The integration of omics and digital technologies in public health will advance our understanding of precision public health. This review introduces the updates of the CNTR, including study design, sample size, biobank, zygosity assessment, advances in research and future systems epidemiologic research.
The East Kunlun Orogen (EKO) is the NW part of the Central China Orogenic Belt, which records the evolutionary history of the Proto- and Palaeo-Tethys Oceans from the Cambrian to the Triassic. An Early Palaeozoic eclogite belt has been recognized in recent years, which extends discontinuously for ∼500 km as three eclogite-bearing terranes. In this study, we report an integrated study of zircon grains from mica-schists accompanying the eclogites, in terms of mineral inclusions, U–Pb age systematics and P–T conditions. The presence of coesite is identified, as inclusions within the metamorphic domain of zircons, which provides unambiguous evidence for subducted terrigenous clastic rocks of the Proto-Tethys Ocean exhumed from coesite-forming depths. U–Pb dating of the metamorphic zircons yields a concordia age of 426.5 ± 0.88 Ma, which is likely to be the time of ultrahigh-pressure metamorphism in the Kehete terrane. P–T calculations suggest that metapelite may have experienced a clockwise P–T path with peak P/T conditions of 685 ± 41 °C and >28 kbar, and equilibrated at 482–566 °C and 5.6–8.9 kbar during subsequent exhumation. The high-pressure – ultrahigh-pressure (HP-UHP) metamorphic belt within the EKO may have formed by collision between the Qaidam Block and the South Kunlun Block, as a consequence of the closure of the Proto-Tethys Ocean.
The prevalence of overweight and obesity is growing rapidly in many countries. Socioeconomic inequalities might be important for this increase. The aim of this study was to determine associations of body mass index (BMI), overweight and obesity with educational level and marital status in Chinese twins. Participants were adult twins recruited through the Chinese National Twin Registry (CNTR), aged 18 to 79 years, and the sample comprised 10,448 same-sex twin pairs. Current height, weight, educational attainment, and marital status were self-reported. Regression analyses and structural equation models were conducted to evaluate BMI, overweight, and obesity associated with educational level and marital status in both sexes. At an individual level, both educational level and marital status were associated with higher BMI and higher risk of being overweight and obesity in men, while in women the effects of educational level on BMI were in the opposite direction. In within-Monozygotic (MZ) twin-pair analyses, the effects of educational level on BMI disappeared in females. Bivariate structural equation models showed that genetic factors and shared environmental confounded the relationship between education and BMI in females, whereas marital status was associated with BMI on account of significant positive unique environmental correlation apart in both sexes. The present data suggested that marital status and BMI were associated, independent of familiar factors, for both sexes of this study population, while common genetic and shared environmental factors contributed to education-associated disparities in BMI in females.
The hot deformation behavior of Nb–V–Ti microalloyed ultra-high strength steel was investigated by isothermal compression at 900–1200 °C with strain rates from 0.01 to 10 s−1. The microstructure evolution and precipitation behavior were studied using an optical microscope and a transmission electron microscope Results indicate that the peak stress of experimental steel increases with increasing the strain rate and decreasing the deformation temperature. The constitutive equation of hot deformation was developed with the activation energy Q being about 407.29 kJ/mol. The processing maps were also obtained to identify the instable regions of the flow behavior and to evaluate the efficiency of hot deformation. The size of dynamically recrystallized grains increases gradually with a decrease in the strain rate. Three types of carbides were identified, namely M3C, rich-Ti MC, and rich-Nb MC. With the increase of the deformation rate, the amounts of carbides increase, and the average sizes of the carbides decrease gradually.
The push–pull fatigue characteristics of the peak-aged Mg–0.2Zn–0.5Zr alloys with different addition levels of neodymium (Nd) have been investigated. The fatigue strength (σf) of the Mg–xNd–0.2Zn–0.5Zr (NZx0K) alloy increases proportionally with the increase of the Nd content (CNd) as follows: σf (T6) ≈ (13.8–14.0) CNd + 46 (for x between 0 and 3.0 wt%). The cyclic stress amplitude also increases but the plastic strain value decreases with the increase of the Nd content. The studied alloys exhibit the strain hardening followed by cyclic softening during fatigue test. During the low-cycle fatigue (LCF) test, the cracks originate from the cyclic deformation and cumulative damage. In high-cycle fatigue (HCF), the failure is due to the cyclic deformation and damage irreversibly caused by environment-assisted cyclic slip. The LCF lives of the alloys fitted well with the Coffin–Manson relation and Basquin laws, the three-parameter equation, and the energy-based concepts. The developed multi-scale fatigue (MSF) life models can be used to predict the LCF and HCF lives of the alloys. Among these models, the MSF life can well capture the influence of Nd addition on fatigue.
Obesity is associated with blood pressure (BP), but the associations between different obesity indicators and BP have not reached agreement. Besides, both obesity and BP are influenced by genetic and environmental factors. Whether they share the same genetic or environmental etiology has not been fully understood. We therefore analyzed the relationship between different obesity indicators and BP components as well as the genetic and environmental contributions to these relationships in a Chinese adult twin sample. Twins aged 18–79 years (n = 941) were included in this study. Body mass index (BMI) was used as the index of general obesity, whereas waist circumference (WC), waist-to-height ratio (WHtR), and waist-to-hip ratio (WHR) were used as the indicators of central obesity. BP components included systolic blood pressure (SBP) and diastolic blood pressure (DBP). Linear regression models and bivariate structural equation models were used to examine the relation of various obesity indicators with BP components, and genetic or environmental influences on these associations, respectively. A strong association of BP components with BMI—and a somewhat weaker association with WC, WHtR, and WHR—was found in both sexes, independent of familial factors. Of these phenotypic correlations between obesity indicators and BP components, 60–76% were attributed to genetic factors, whereas 24–40% were attributed to unique environmental factors. General obesity was most strongly associated with high BP in Chinese adult twins. There were common genetic backgrounds for obesity and BP, and unique environmental factors also played a role.
To study the hot deformation behavior of the Ti–22Al–25Nb alloy, isothermal compression tests were conducted at the temperature range of 930–1080 °C with strain rates of 0.001–1.0 s−1. Both the strain rate and the deformation temperature have a significant influence on the stress–strain behavior of the Ti–22Al–25Nb alloy. A hyperbolic–sine constitutive equation is established to quantitatively demonstrate the relationship between the parameters involved, and the hot deformation activation energy Q is determined as 621 kJ/mol. To optimize the processing window, a hot processing map is established, which is related to the microstructure evolution in hot working. The lamellar globularization as well as the dynamic recrystallization (DRX) would contribute to the stable regions with high power dissipation, while the adiabatic shear bands would lead to unstable regions. Moreover, an Avrami-type kinetics model is applied to examine the evolution of DRX during isothermal deformation process.
To investigate the effects of cold rolling on the microstructure, the precipitation behavior and the morphology of δ-phase, Inconel 718 alloy samples with different cold rolling reductions were aged for different periods at temperatures range from 850 °C to 1000 °C. Detailed microstructural observations and quantitative measurements were conducted to characterize the evolution of the δ-phase during aging. The results show that the microstructure consists of large deformed grains as a result of a slow static recovery at the low aging temperatures (850 and 900 °C); whereas the austenite matrix is fully recrystallized at the high aging temperatures (950 and 1000 °C). It is also found that the amount of δ-phase and the number density of spherical δ-phase particles increase with the increase in the degree of cold rolling both at low and high aging temperatures. With respect to different microstructural changes for the cold-rolled samples at the low or the high aging temperatures, two distinct mechanisms have been, respectively, introduced to interpret the changes in the precipitation behavior and the appearance of δ-phase.
The microstructural evolution of type 347H heat-resistant austenitic steel during long-term aging at 700–900 °C was investigated by using a transmission microscope, a scanning electron microscope, and electron energy spectrum technology. The microstructural examination showed the typical micrographs of MX carbonitrides and M23C6 carbides after aging. The existence of the Z phase (NbCrN) at the grain boundaries during aging was identified. Meanwhile, the possible precipitation sequence of these particles was also confirmed. In the beginning of aging, fine Nb(C,N) precipitates first, then, M23C6 carbides precipitate along the grain boundaries. Finally, the Z phase is also observed at the grain boundaries. Moreover, the influence of isothermal holding temperature on the precipitation of MX carbonitrides and M23C6 carbides was discussed. The various microstructural characterizations showed that the M23C6 carbides and MX carbonitrides precipitate more easily with the increase of aging temperature. Furthermore, the number and the size of MX particles and M23C6 carbides increase when the isothermal holding time is prolonged.
This study examined the genetic and environmental effects on variances in weight, height, and body mass index (BMI) under 18 years in a population-based sample from China. We selected 6,644 monozygotic and 5,969 dizygotic twin pairs from the Chinese National Twin Registry (CNTR) aged under 18 years (n = 12,613). Classic twin analyses with sex limitation were used to estimate the genetic and environmental components of weight, height, and BMI in six age groups. Sex-limitation of genetic and shared environmental effects was observed, especially when puberty begins. Heritability for weight, height, and BMI was low at 0–2 years old (less than 20% for both sexes) but increased over time, accounting for half or more of the variance in the 15–17 year age group for boys. For girls, heritabilities for weight, height and BMI was maintained at approximately 30% after puberty. Common environmental effects on all body measures were high for girls (59–87%) and presented a small peak during puberty. Genetics appear to play an increasingly important role in explaining the variation in weight, height, and BMI from early childhood to late adolescence, particularly in boys. Common environmental factors exert their strongest and most independent influence specifically in the pre-adolescent period and more significantly in girls. These findings emphasize the need to target family and social environmental interventions in early childhood years, especially for females. Further studies about puberty-related genes and social environment are needed to clarify the mechanism of sex differences.
To study the thermal deformation behavior and microstructural evolution of the type 347H austenitic steel, compression experiments were conducted at the temperatures of 800–1100 °C with strain rates of 0.01–10 s−1. The activation energy and constitutive equation of the type 347H steel during thermal deformation process were determined according to the flow stress curves. Both the hot processing maps and microstructure characteristics under different deformation conditions were investigated. Based on the thermal processing maps, two unstable regions under 800 °C/0.01–10 s−1 and 1100 °C/0.01 s−1 were identified. The processing maps were in favor of optimizing thermal processing parameters and improving thermal processing properties of the type 347H austenitic steel. After thermal deformation, the dislocation in the austenite matrix increases significantly. Besides, in the stable regions, the precipitation of carbides is facilitated by thermal deformation.
The genetic contribution of blood pressure and heart rate (HR) varied widely between studies. Demographic factors such as ethnicity, age and/or sex might explain some of the heterogeneity. We performed a systematic review focusing on four phenotypes: systolic blood pressure (SBP), diastolic blood pressure (DBP), HR and pulse pressure (PP). Meta-regression was conducted to analyze potential factors in relation to SBP and DBP heritability. A total of 10,613 independent twins that came from 17 studies were included in the analysis. The weighted mean value of heritability for SBP and DBP was 0.54 (95% CIs: 0.48–0.60) and 0.49 (95% CIs: 0.42–0.56). Comparatively, three studies of HR and four studies of PP heritability were limited for the heterogeneity test. Meta-regression showed that, on average, SBP heritability with additive genes/unique environment (AE) model tend to have a higher heritability than additive genes/shared environment/unique environment (ACE) model (coefficient = 0.0947, p = .0142). A similar result was found for DBP as well. No other factors such as sex, age, ethnicity, publication year were significantly associated with heritability variance. Our study shows heritability estimates based on twin studies of both SBP and DBP are around 50%, using an AE rather than an ACE model; the variance due to C ended up in A, suggesting that the AE model may overestimate heritability if a small contribution of shared environment exists.
Twins reared apart provide a fascinating experiment to distinguish genetic from environmental influences. However, there is as yet no broad report on distribution of twins reared apart, especially in the Chinese population. In this study, information on 18,295 volunteer twin pairs of all age groups was compiled in nine provinces or cities of China, and questionnaires were used for zygosity determination. It was discovered that twins reared apart from 0 to 10 years of age accounted for 2.2% of all twin interviewees, with the proportion of this 0–10 group separated before 1, 2, and 5 years old, accounting for 65.3%, 76.1%, and 91.3%, respectively. The proportion of twins reared apart is not significantly related to zygosity or gender, but it is related to region and twin age. As the age of twins lowers, the proportion of those reared apart gradually decreases. Twins reared apart will become rarer in the future and therefore should be cherished as a resource.