We explored the genetic architecture of metabolic risk factors of cardiovascular diseases (CVDs) and their clustering in Chinese boys and girls. Seven metabolic traits (body mass index [BMI], waist circumference [WC], systolic blood pressure [SBP], diastolic blood pressure [DBP], total cholesterol [TC], triglyceride [TG], and uric acid [UA]) were measured in a sample of 1016 twins between 8 and 17 years of age, recruited from the Qingdao Twin Registry. Cholesky, independent pathway, and common pathway models were used to identify the latent genetic structure behind the clustering of these metabolic traits. Genetic architecture of these metabolic traits was largely similar in boys and girls. The highest heritability was found for BMI (a2 = 0.63) in boys and TC (a2 = .69) in girls. Three heritable factors, adiposity (BMI and WC), blood pressure (SBP and DBP), and metabolite factors (TC, TG, and UA), which formed one higher-order latent phenotype, were identified. Latent genetic, common environmental, and unique environmental factors indirectly impacted the three factors through one single latent factor. Our results suggest that there is one latent factor influencing several metabolic traits, which are known risk factors of CVDs in young Chinese twins. Latent genetic, common environmental, and unique environmental factors indirectly imposed on them. These results inform strategies for gene pleiotropic discovery and intervening of CVD risk factors during childhood and adolescence.

Pressure-induced crystallographic transitions and optical behavior of MAPbI3 (MA=methylammonium) were investigated using in-situ synchrotron X-ray diffraction and laser-excited photoluminescence spectroscopy. We observed that the tetragonal phase that presents under ambient pressure transformed to a ReO3-type cubic phase at 0.3 GPa, which further converted into a putative orthorhombic structure at 2.7 GPa. The sample was finally separated into crystalline and amorphous fractions beyond 4.7 GPa. During the decompression, the phase-mixed material restored the original structure in two distinct pathways depending on the peak pressures. Being monitored using a laser-excited photoluminescence technique under each applied pressure, it was determined that the bandgap reduced with an increase of the pressure till 0.3 GPa and then enlarged with an increase of the pressure up to 2.7 GPa. This work lays the foundation for understanding pressure-induced phase transitions and bandgap tuning of MAPbI3, enriching potentially the toolkit for engineering perovskites related photovoltaic devices.

The computation efficiency of high dimensional (3D and 4D) B-spline interpolation, constructed by classical tensor product method, is improved greatly by precomputing the B-spline function. This is due to the character of NLT code, i.e. only the linearised characteristics are needed so that the unperturbed orbit as well as values of the B-spline function at interpolation points can be precomputed at the beginning of the simulation. By integrating this fixed point interpolation algorithm into NLT code, the high dimensional gyro-kinetic Vlasov equation can be solved directly without operator splitting method which is applied in conventional semi-Lagrangian codes. In the Rosenbluth-Hinton test, NLT runs a few times faster for Vlasov solver part and converges at about one order larger time step than conventional splitting code.

The genetic influences on aging-related phenotypes, including cognition and depression, have been well confirmed in the Western populations. We performed the first twin-based analysis on cognitive performance, memory and depression status in middle-aged and elderly Chinese twins, representing the world's largest and most rapidly aging population. The sample consisted of 384 twin pairs with a median age of 50 years. Cognitive function was measured using the Montreal Cognitive Assessment (MoCA) scale; memory was assessed using the revised Wechsler Adult Intelligence scale; depression symptomatology was evaluated by the self-reported 30-item Geriatric Depression (GDS-30)scale. Both univariate and multivariate twin models were fitted to the three phenotypes with full and nested models and compared to select the best fitting models. Univariate analysis showed moderate-to-high genetic influences with heritability 0.44 for cognition and 0.56 for memory. Multivariate analysis by the reduced Cholesky model estimated significant genetic (rG = 0.69) and unique environmental (rE = 0.25) correlation between cognitive ability and memory. The model also estimated weak but significant inverse genetic correlation for depression with cognition (-0.31) and memory (-0.28). No significant unique environmental correlation was found for depression with other two phenotypes. In conclusion, there can be a common genetic architecture for cognitive ability and memory that weakly correlates with depression symptomatology, but in the opposite direction.

Systolic and diastolic blood pressure, pulse pressure (PP), and body mass index (BMI) are heritable traits in human metabolic health but their common genetic and environmental backgrounds are not well investigated. The aim of this article was to explore the phenotypic and genetic associations among PP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and BMI. The studied sample contained 615 twin pairs (17–84 years) collected in the Qingdao municipality. Univariate and multivariate structural equation models were fitted for assessing the genetic and environmental contributions. The AE model combining additive genetic (A) and unique environmental (E) factors produced the best fit for each four phenotypes. Heritability estimated in univariate analysis ranged from 0.42 to 0.74 with the highest for BMI (95% CI 0.70–0.78), and the lowest for PP (95% CI 0.34–0.49). The multivariate model estimated (1) high genetic correlations for DBP with SBP (0.87), PP with SBP (0.75); (2) low–moderate genetic correlations between PP and DBP (0.32), each BP component and BMI (0.24–0.37); (3) moderate unique environmental correlation for PP with SBP (0.68) and SBP with DBP (0.63); (4) there was no significant unique environmental correlation between PP and BMI. Overall, our multivariate analyses revealed common genetic and environmental backgrounds for PP, BP, and BMI in Chinese twins.

Hierarchical Zn0.5Cd0.5S nanohexagon dendrites were synthesized by a one-step hydrothermal method. The Zn0.5Cd0.5S nanohexagon dendrites were made up of nanohexagons with a side length of about 90 nm. The nanohexagons were regularly arranged forming as embranchments which were parallel to each other along certain hexagonal directions. Furthermore, these embranchments made up primary trunks shaping as dendrites. The growth mechanism of Zn0.5Cd0.5S nanohexagon dendrites was proposed in which molecular soft template and lowest energy principle played key roles. By adjusting the composition of the reactants, a series of ZnxCd1–xS solid solutions could be obtained. The morphology of the synthesized ZnxCd1–xS depended much on the x value. The UV-vis spectra absorb edges of the ZnxCd1–xS samples continuously shifted indicating the changes of the band gap.

We evaluated the genetic and environmental contributions to metabolic cardiovascular risk factors and their mutual associations. Eight metabolic factors (body mass index, waist circumference, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, total serum cholesterol, serum triglycerides, and serum uric acid) were measured in 508 twin pairs aged 8–17 years from the Qingdao Twin Registry, China. Linear structural equation models were used to estimate the heritability of these traits, as well as the genetic and environmental correlations between them. Among boys, body mass index and uric acid showed consistently high heritability (0.49–0.81), whereas other traits showed moderate to high common environmental variance (0.37–0.73) in children (8–12 years) and adolescents (13–17 years) except total cholesterol. For girls, moderate to high heritability (0.39–0.75) were obtained for six metabolic traits in children, while only two traits showed high heritability and others mostly medium to large common environmental variance in adolescents. Genetic correlations between the traits were strong in both boys and girls in children (r g = 0.64–0.99 between body mass index and diastolic blood pressure; r g = 0.71–1.00 between body mass index and waist circumference), but decreased for adolescent girls (r g = 0.51 between body mass index and waist-to-hip ratio; r g = 0.55 between body mass index and uric acid; r g = 0.61 between body mass index and systolic blood pressure). The effect of genetic factors on most metabolic traits decreased from childhood to adolescence. Both common genetic and specific environmental factors influence the mutual associations among most of the metabolic traits.

In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes using twin modeling and genome-wide association analysis. Cross-cultural collaborative studies have been carried out between China, Denmark, Finland, and US cohorts. Ongoing data collection and analysis for the Qingdao Twin Registry will be discussed in this article.

Elevated pulse pressure is associated with cardiovascular disorders and mortality in various populations. The genetic influence on pulse pressure has been confirmed by heritability estimates using related individuals. Recently, efforts have been made in mapping genes that are linked to the phenotype. We report results on our heritability and linkage study conducted on the Chinese population in mainland China where cardiovascular and cerebrovascular diseases are becoming the leading cause of death. A total of 630 pairs of middle-aged Chinese twins were collected for heritability analysis, from which 63 dizygotic twin pairs were randomly selected for genome-wide linkage analysis using Affymetrix 6.0 SNP array. Regression analysis reconfirmed the significant effects of age, sex, and BMI on pulse pressure. Comparison of twin models suggested the parsimonious AE model as the best model with a heritability estimate of 0.45. Genome-wide non-parametric linkage analysis identified three significant linkage peaks on chromosome 11 (lod score 4.06 at 30.5 cM), chromosome 12 (lod score 3.97 at 100.7 cM), and chromosome 18 (lod score 4.01 at 70.7 cM) with the last two peaks closely overlapping with linkage peaks reported by two American studies. In addition, multiple regions with suggestive linkage were identified with many of them overlapping with published linkage regions. Our results provide both epidemiological and molecular genetic evidence for the genetic dissection of pulse pressure in the Chinese population, which could help in fine mapping and in characterizing genes that are involved in the regulation of pulse pressure.

Positron annihilation lifetime measurements are performed for sol–gel-derived 70 mol% SiO2–30 mol% CaO bioactive glass. Strong positronium formation processes are shown to be an inherent feature for these kinds of materials. Observed orthopositronium (o-Ps) lifetimes show a three-modal distribution with lifetime values weighed at ∼2, ∼18, and ∼70 ns. The exposure of the investigated sol–gel-derived bioactive glasses to water vapor significantly modifies o-Ps lifetime distribution due to the penetration of water molecules into the nanopores, indicating high ratio of their interconnectivity. Classic Tao–Eldrup equation is used to relate the o-Ps lifetimes with the size of nanopores, whose distribution is verified by nitrogen adsorption porosimetry.

Background: Though multiple policies have been implemented, the cigarette control in China is still facing a great challenge. At the same time, alcohol drinking has increasingly become a public health problem. Considering cigarette smoking and alcohol drinking often co-occur, a few studies tested the covariance of these phenotypes. However, the genetic and environmental correlation between them among Chinese population has not been determined. The main aim of this study is to fill this gap. Methods: From the Chinese National Twin Registry, we obtained the data on cigarette smoking and alcohol drinking behaviors. The ordinal bivariate genetic analysis was performed to fit the categorical variables. After identifying the best decomposition among the Cholesky, common, and independent pathway model, we established the most parsimonious submodel. Results: The correlation between current tobacco and alcohol use could be explained by Cholesky model. The shared environmental variances for both phenotypes were dropped to construct the most parsimonious submodel. Furthermore, the most parsimonious submodel showed a moderate correlation (0.32, 95%CI = 0.17 – 0.46) between the genetic components and a negligible non-shared environmental correlation. Conclusion: As the first bivariate genetic analysis on current tobacco smoking and current alcohol drinking in China, this study suggested a common genetic vulnerability to tobacco and alcohol use in male twins. Further studies should be carried out to track the pertinent genes that are related to the comorbidity of smoking and drinking in Chinese population. Another urgent need is to recognize the behavior-specific environmental risk factors.

Health is a multidimensional and continual concept. Traditional latent analytic approaches have inherent deficits in capturing the complex nature of the concept; however, the Grade of Membership (GoM) model is well suited for this problem. We applied the GoM method to a set of 31 indicators to construct ideal profiles of health status based on physical, mental and social support items among 848 adult twins from Qingdao, China. Four profiles were identified: healthy individuals (pure type I), individuals with personality disorders (pure type II), individuals with mental impairments (pure type III) and individuals with physical impairments (pure type IV). The most frequently occurring combination in this population was profiles I, II, IV (14.74%), followed by profiles I, II, III, IV (13.44%), and then type I (11.08%). Only 13.56% of subjects fell completely into one single pure type, most individuals exhibited some of the characteristics of two or more pure types. Our results indicated that, compared to conventional statistical methods, the GoM model was more suited to capture the complex concept of health, reflecting its multidimensionality and continuity, while also exhibiting preferable reliability. This study also made an important contribution to research on GoM application in non-independent samples.

This study reports on the determination of zygosity in Chinese adult twins by simple questionnaire and physical features comparison. The subjects were 511 twin pairs from two cities and their town areas, consisting of 371 monozygotic (MZ) and 140 same-sex dizygotic (DZ) pairs, identified by ABO blood group and multiplex polymerase chain reaction of several polymorphic short tandem repeat markers. The twins themselves responded to 8 questionnaire items, 4 items on twin similarity, and 4 items on the frequency of mistaking one twin for another by parents, relatives, teachers and strangers when they were 6 to 13 years old. Research assistants responded to 20 items regarding twins' physical features at the moment of interview. A parsimonious model established using stepwise logistic regression analysis of the 28 items showed that the total accuracy of zygosity diagnosis was 90.1%. The accuracy was 89.2% when using only the items dealing with the confusion of twins and 85.4% using only similarity. In the questionnaire, ‘facial appearance’, ‘mistaken by teachers’ and ‘mistaken by strangers’ had stronger discriminating power between MZ and DZ twins. Two physical features — ‘eyelid’ and ‘middigital hair’ — were informative to some extent. There was no statistically significant sex and area difference in the validity of such questionnaire and physical features comparison-based classification. In conclusion, questionnaire-based zygosity assessment in this Chinese adult twin sample could still be regarded as a valid and valuable classification method. Physical features comparison, however, could only provide limited information for zygosity determination.

With the changing patterns of morbidity and mortality in China, noncommunicable chronic diseases have become the major threats to the health of the Chinese population. The causes of chronic diseases include genetic factors and behavioral risk factors such as the use of tobacco, alcohol, and other drugs, unhealthy dietary behaviors, and lack of physical activity. Twin studies offer a unique opportunity to disentangle the genetic and environmental risk and protective factors for chronic disease. The Qingdao Twin Registry (QTR) was initiated in 1998 as part of the National Chinese Twin Registry. Over 11,000 pairs of twins and multiples of all ages have been recruited into the registry. Several studies of physical and mental health are underway. Many of the adult twins have completed health and behavioral risk factor surveys, and the adolescent twins are participating in a study of gene–environment interactions in tobacco and alcohol use. Studies of the heritability of personality factors have been conducted. In 2002, Qingdao established the Qingdao Twin Health Promotion Association, a nonprofit organization that supports health services for twins and their parents, organizes special events and health-related activities for twins, and raises funds to conduct twin health examinations. The QTR will be a useful resource for future studies of population genetics in human health and disease.

We report on the preparation of a bioactive CaO–SiO2 monolithic scaffold with interconnected bimodal nanomacro porosity, which simulates the morphology of a natural trabecular bone, by a newly developed modified sol-gel process. This method inherently creates nanopores, whose average diameter can be tailored to approximately 5–20 nm by solvent exchange. To achieve interconnected macroporosity (pores ∼5–300 μm in size), a polymer [poly(ethylene oxide)] is added, which causes phase separation simultaneously with the sol-gel transition. High-resolution scanning electron microscopy and mercury intrusion porosimetry demonstrate a high degree of three-dimensional interconnectivity and sharp distributions of pore size. In vitro bioactivity tests in simulated body fluid (SBF) show bioactivity of the material after soaking for approximately 5 h, as verified by the formation of a hydroxyapatite layer deep into the scaffold structure. Analysis of the SBF after the reaction indicates the dissolution of the samples, another desired feature of temporary scaffolds for bone regeneration. MG63 osteoblast-like cells seeded on our sol-gel glass samples responded better to samples with nanopores enlarged by a solvent exchange process than to the one with normal nanopores. Thus, the benefits of the high surface area achieved by sol-gel and solvent exchange procedures are most clearly demonstrated for the first time.

Large-scale, well-aligned, and oriented ZnS nanorod arrays were fabricated by a novel and original template-free hydrothermal method. The ZnS nanorods were grown on the pulse-plating Zn nanocrystallines along a certain Zn crystalline direction. It was found that reaction factors such as hydrothermal reaction time, zinc source, and sulfide source concentration in the precursor solution, the acid–base property of the precursor solution, and the substrate where ZnS nanorod arrays were grown greatly influence the morphology of the final products. The growth mechanism of ZnS nanorod arrays was also studied. Pulse-plating Zn nanocrystallines were found to be essential for the growth of ZnS nanorod arrays. These ZnS nanorod arrays could be theoretically fabricated on almost any raw base plate as long as Zn nanocrystallines could be pulse-plated on it. Therefore, the as-synthesized ZnS nanorod array might be one of the promising candidates for field-emission or sensitive nanomaterials in the future.