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Objective: To examine the external validity of the Fetal Medicine Foundation (FMF) competing‐risks model for the prediction of small‐for‐gestational age (SGA) at 11–14 weeks' gestation in an Asian population. Methods: This was a secondary analysis of a multicenter prospective cohort study in 10 120 women with a singleton pregnancy undergoing routine assessment at 11–14 weeks' gestation. We applied the FMF competing‐risks model for the first‐trimester prediction of SGA, combining maternal characteristics and medical history with measurements of mean arterial pressure (MAP), uterine artery pulsatility index (UtA‐PI) and serum placental growth factor (PlGF) concentration. We calculated risks for different cut‐offs of birth‐weight percentile (< 10th, < 5th or < 3rd percentile) and gestational age at delivery (< 37 weeks (preterm SGA) or SGA at any gestational age). Predictive performance was examined in terms of discrimination and calibration. Results: The predictive performance of the competing‐risks model for SGA was similar to that reported in the original FMF study. Specifically, the combination of maternal factors with MAP, UtA‐PI and PlGF yielded the best performance for the prediction of preterm SGA with birth weight < 10th percentile (SGA < 10th) and preterm SGA with birth weight < 5th percentile (SGA < 5th), with areas under the receiver‐operating‐characteristics curve (AUCs) of 0.765 (95% CI, 0.720–0.809) and 0.789 (95% CI, 0.736–0.841), respectively. Combining maternal factors with MAP and PlGF yielded the best model for predicting preterm SGA with birth weight < 3rd percentile (SGA < 3rd) (AUC, 0.797 (95% CI, 0.744–0.850)). After excluding cases with pre‐eclampsia, the combination of maternal factors with MAP, UtA‐PI and PlGF yielded the best performance for the prediction of preterm SGA < 10th and preterm SGA < 5th, with AUCs of 0.743 (95% CI, 0.691–0.795) and 0.762 (95% CI, 0.700–0.824), respectively. However, the best model for predicting preterm SGA < 3rd without pre‐eclampsia was the combination of maternal factors and PlGF (AUC, 0.786 (95% CI, 0.723–0.849)). The FMF competing‐risks model including maternal factors, MAP, UtA‐PI and PlGF achieved detection rates of 42.2%, 47.3% and 48.1%, at a fixed false‐positive rate of 10%, for the prediction of preterm SGA < 10th, preterm SGA < 5th and preterm SGA < 3rd, respectively. The calibration of the model was satisfactory. Conclusion: The screening performance of the FMF first‐trimester competing‐risks model for SGA in a large, independent cohort of Asian women is comparable with that reported in the original FMF study in a mixed European population. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

To improve the reliability of the end faces of high-temperature mechanical seals, a high-performance composite material that introduces carbon nanotubes (CNTs) into the laser-melted Cr coating is proposed. In this study, for high-temperature and high-speed mechanical seals under actual working conditions, friction and wear tests were conducted under different working conditions and using different end face materials. The high-temperature tribological properties of the Cr-CNTs coatings were analyzed, and the strengthening mechanism of the Cr-CNTs coatings on end faces was investigated. The results indicate that the wear resistance of the Cr-CNTs coating at high temperatures is first enhanced and then weakened with the increase in the CNTs content. The composite coating end face performance is optimal when the CNTs content is 10 wt%. The presence of CNTs between the end faces when grinding against the graphite ring favors the generation of a graphite film. The coefficient of friction of the Cr-CNTs coating is reduced by at least 12.46% compared to the Cr coating at a temperature of 483 K. This study provides reference examples for the application of carbon nanotubes in high-performance mechanical seals and new research ideas for improving the performance of mechanical seal end faces. [ABSTRACT FROM AUTHOR]

The health risks of fine particulate matter (PM 2.5) and ambient ozone (O 3) have been widely recognized in recent years. An accurate estimate of PM 2.5 and O 3 exposures is important for supporting health risk analysis and environmental policy-making. The aim of our study was to construct random forest models with high-performance and estimate daily average PM 2.5 concentration and O 3 daily maximum of 8 h average concentration (O 3 -8 hmax) of China in 2005–2017 at a spatial resolution of 1 km × 1 km. The model variables included meteorological variables, satellite data, chemical transport model output, geographic variables and socioeconomic variables. Random forest model based on 10-fold cross-validation was established, and spatial and temporal validations were performed to evaluate the model performance. According to our sample-based division method, the daily, monthly and yearly estimations of PM 2.5 from test datasets gave average model-fitting R2 values of 0.85, 0.88 and 0.90, respectively; these R2 values were 0.77, 0.77 and 0.69 for O 3 -8 hmax, respectively. The meteorological variables and their lagged values can significantly affect both PM 2.5 and O 3 -8 hmax estimations. During 2005–2017, PM 2.5 concentration exhibited an overall downward trend, while ambient O 3 concentration experienced an upward trend. Whilst the spatial patterns of PM 2.5 and O 3 -8 hmax barely changed between 2005 and 2017, the temporal trend had spatial characteristics. The dataset is accessible to the public at 10.5281/zenodo.4009308 (Ma et al., 2021a), and the shared dataset of Chinese Environmental Public Health Tracking (CEPHT, 2022) is available at https://cepht.niehs.cn:8282/developSDS3.html. [ABSTRACT FROM AUTHOR]

Background: We aimed to appraise the impact of the changing national childbirth policy since 2002, currently allowing two children per family, on obstetric workload in a regional referral center in China.Methods: In a retrospective cohort study, temporal changes were examined in relation with maternal demographics, incidence of women with high risk pregnancies and resource statistics in our hospital in managing singleton viable pregnancies (birth from 28 weeks gestational age onwards) for the period 2005-2017.Results: During this 13-year period, the number of singleton livebirths from 28 weeks gestational age onwards was 49,479. Annual numbers of births increased from 1,941 to 2005 to 5,777 in 2017. There were concomitant and significant increases in the incidence of multiparous women (10.6-50.8 %), of age ≥35 years (6.5-24.3 %), with prior caesarean Sec. (2.6-23.6 %), with ≥3 previous pregnancy terminations (1.0-4.9 %), with pre-gestational diabetes (0.2-0.9 %), and with chronic hypertension (0.2-1.2 %). There were associated increases in beds and staff complement and reduced average hospital stay. Nevertheless, while the workload of medical staff remained stable with increasing staff complement, that of midwives increased significantly as reflected by the total births: midwife ratio which increased from 194.1:1 to 320.9:1 (p < 0.001).Conclusions: In our hospital, progressively increasing numbers of annual births in combination with an increased incidence of women with high risk pregnancies took place following the revised national childbirth policy. Only the increase in medical and nursing, but not midwifery, staff was commensurate with workload. Remedial measures are urgently required before the anticipated progressive increase in care demand would overwhelm maternity care with potentially disastrous consequences. [ABSTRACT FROM AUTHOR]

Background: Chinese population has a high prevalence of chronic hepatitis B virus (HBV) infection, the impact of which on pregnancy outcome remains controversial. A single-center retrospective cohort study was performed in Kunming, a multi-ethnic city in south-western China to examine this issue.Methods: The singleton pregnancies delivering at ≥28 weeks gestation under our care in 2005-2017 constituted the study cohort. Maternal characteristics and pregnancy outcome were compared between mothers with and without seropositivity for hepatitis B surface antigen (HBsAg) determined at routine antenatal screening.Results: Among the 49,479 gravidae in the cohort, the 1624 (3.3%) HBsAg seropositive gravidae had a lower incidence of nulliparity (RR 0.963, 95% CI 0.935-0.992) and having received tertiary education (RR 0.829, 95% CI 0.784-0.827). There was no significant difference in the medical history, pregnancy complications, or labor or perinatal outcome, except that HBV carriers had significantly lower incidence of labor induction (RR 0.827, 95% CI 0.714-0.958) and of small-for-gestational age (SGA) infants (RR 0.854, 95% CI 0.734-0.994). On regression analysis, maternal HBV carriage was independently associated with spontaneous labor (aRR 1.231, 95% CI 1.044-1.451) and reduced SGA infants (aRR 0.842, 95% CI 0.712-0.997).Conclusions: Our 3.3% prevalence of maternal HBV infection was around the lower range determined in the Chinese population. The association with spontaneous labor and reduced SGA infants could have helped to promote the perpetuation of the infection through enhanced survival of the offspring infected at birth, thus explaining the high prevalence in the Chinese population. [ABSTRACT FROM AUTHOR]

Aim: To describe changed epidemiological features of advanced maternal age (AMA) and to examine the effect of AMA on the risk for Cesarean section (CS) in a Chinese pregnant population. Methods: This retrospective single‐center cohort study investigated the changes of epidemiological features of AMA parturients with respect to the revised reproductive policy in China in 43 702 singleton deliveries with live birth at ≥28 weeks managed from January 2005 to December 2016. We also evaluated the pregnancy outcomes in different age groups and risk factors of CS with multivariate analysis. Results: In this 12‐year study period, the average maternal age increased from 28.5 to 30.2 years, and the proportion of AMA raised from 6.5% to 17.2%. AMA was significantly associated with increased risk of adverse pregnancy outcomes, and after adjustment for confounding factors, AMA remained a significant independent risk factor for CS. Furthermore, the effect of AMA in nulliparous women on the risk of CS was more significant than in multiparous women, while the history of previous CS (adjusted odds ratio 39.85) and interdelivery interval ≥10 years (adjusted odds ratio 1.52) also increased the risk of CS in multiparous women. Conclusion: AMA increased the risk of a number of adverse pregnancy outcomes, and was independently associated with increased risk for CS. The increasing number of AMA parturients with risk factors is likely to increase CS rate in China in the near future, thus it is imperative to reduce the rate of primary CS as a matter of policy. [ABSTRACT FROM AUTHOR]

Objectives. Our aim is to explore the clinical outcome of patients with acute fatty liver of pregnancy (AFLP), and evaluate the effect of early diagnosis and treatment. Methods. Seven patients who were diagnosed with AFLP were retrospectively analyzed from February 2005 to January 2013. The clinical records of the patients with AFLP were reviewed for clinical features, laboratory examinations, and maternal and perinatal prognosis. Routine laboratory evaluation revealed hyperbilirubinemia, moderately elevated liver transaminase, but negative serum hepatitis virus in each patient. For additional evidence, 126 cases of AFLP were reviewed retrospectively from original articles researched in A Medline-based English and Chinese Knowledge Infrastructure between the same periods. Results. The initial symptoms of all the 7 cases with AFLP were gastrointestinal symptoms; anorexia, nausea, vomiting, and progressive jaundice. Complications revealed with renal insufficiency in all 7 patients. Hepatic failure, MODS, hypoglycemia and DIC were seen in 4 patients (57.1%). Hemorrhagic shock, ARDS, and hepatic encephalopathy were seen in 3 patients (42.8%). There was only one case of maternal death (14.2%), three cases of perinatal death (30%) and one postnatal death (10%). Conclusion. AFLP occurs in late pregnancy is a rare clinical syndrome occurs at about 36 weeks of gestation. Early diagnosis and prompt termination of pregnancy is the key of management with multidisciplinary collaboration, comprehensive treatment and effective prevention are helpful to improve prognosis of the cases with AFLP and perinatal death. [ABSTRACT FROM AUTHOR]

Graphite-based composites are well recognized as ideal functional materials in mechanical seals, bearings of canned pumps, and electrical contact systems because of their outstanding self-lubricating ability, thermostability, and chemical stability. Working in harsh conditions is a huge challenge for the graphite materials, and their tribological properties and wear mechanisms are not well studied. In this study, the tribological performance of metal-impregnated graphite, resin-impregnated graphite, and non-metal-impregnated graphite under high temperature and high load are studied using a ball-on-disc tribometer. The results show that the metal-impregnated graphite (Metal-IG) has a stable friction regime and exhibits better anti-friction and anti-wear properties than that of resin-impregnated graphite (Resin-IG) and non-impregnated graphite (Non-IG) under extreme pressure (200~350 MPa) and high temperature (100–350 ℃). The Metal-IG and Resin-IG can reduce the wear depth by 60% and 80%, respectively, when compared with Non-IG substrate. The impregnated materials (metal or resin) can enhance the strength of the graphite matrix and improve the formation of graphite tribofilm on the counterpart surfaces. Friction-induced structural ordering of graphite and slight oxidation of metal in the formed mechanically mixed layer is also beneficial for friction and wear reduction. This study demonstrates the tribological characteristics of impregnated graphite under harsh conditions and provides the experimental basis for the advanced usage of high-reliability and self-lubrication graphite composites. [ABSTRACT FROM AUTHOR]

Purpose To investigate whether prenatal screening for thalassemia is presented as a choice, and how the condition is described in written information given to pregnant women in different countries. Method One leaflet from each of seven countries (UK, The Netherlands, Greece, Italy, Israel, India and China) was collected for evaluation. Statements relating to choice and those describing the condition were extracted for analysis. Results The leaflets varied in length from 26 to 74 sentences (mean: 42). Overall, more sentences were devoted to describing the condition (mean: 5) than to conveying choice (mean: 2). Leaflets from Northern Europe contained the highest proportion of sentences relating to choice, while those from Italy and Israel contained none. The majority of sentences describing thalassemia were classified as negative. The leaflets from China and India contained the highest proportion of negative sentences and the leaflets from the Netherlands and Italy, the lowest. Conclusion For women to make an informed decision they need to be offered a choice and given balanced information regarding the condition for which screening is being offered. The results of this study raise doubts as to the extent to which prenatal services in many countries are facilitating informed choices. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

To date, studies assessing whether the information given to people about screening tests facilitates informed choices have focussed mainly on the UK, US and Australia. The extent to which written information given in other countries facilitates informed choices is not known. The aim of this study is to describe the presentation of choice and information about Down's syndrome in written information about prenatal screening given to pregnant women in five European and two Asian countries. Leaflets were obtained from clinicians in UK, Netherlands, Spain, Italy, Czech Republic, China and India. Two analyses were conducted. First, all relevant text relating to the choice about undergoing screening was extracted and described. Second, each separate piece of information or statement about the condition being screened for was extracted and then coded as either positive, negative or neutral. Only Down's syndrome was included in the analysis since there was relatively little information about other conditions. There was a strong emphasis on choice and the need for discussion about prenatal screening tests in the leaflets from the UK and Netherlands. The leaflet from the UK gave most information about Down's syndrome and the smallest proportion of negative information. By contrast, the Chinese leaflet did not mention choice and gave the most negative information about Down's syndrome. Leaflets from the other countries were more variable. This variation may reflect cultural differences in attitudes to informed choice or a failure to facilitate informed choice in practice. More detailed studies are needed to explore this further.European Journal of Human Genetics (2007) 15, 563–569. doi:10.1038/sj.ejhg.5201790; published online 21 February 2007 [ABSTRACT FROM AUTHOR]