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Background The most serious problem during vaginal birth after caesarean section (VBAC) is the risk of uterine rupture but there is controversy regarding important related factors. With the relaxation of birth policy in China, the maternal and perinatal outcomes after uterine rupture during VBAC are a societal concern. The lack of any large-scale study of uterine rupture during VBAC in China underscores the need for more research evidence. Methods We studied singleton pregnant women with VBAC from 2012 to 2019 registered in China’s National Maternal Near-Miss Surveillance System (NMNMSS). First, we calculated the incidence of uterine rupture during VBAC. Second, using a logistic regression model with weighting for the sampling distribution of the population and clustering of births within hospitals, we examined the association of sociodemographic and obstetric characteristics and maternal diseases with uterine rupture during VBAC. With multivariable logistic regression, adjusted odds ratio were estimated using two models. Finally, we compared the risk of adverse maternal and perinatal outcomes in women with and without uterine rupture during VBAC. Results This study included 155774 singleton pregnant women with VBAC, and the incidence of uterine rupture was 0.23%. Characteristics associated with the increased risk of uterine rupture during VBAC included two (aOR = 1.70; 95% CI: 1.06–2.73) and three or more (aOR = 2.59; 95% CI: 0.54–12.44) previous caesarean sections, delivery at 42 weeks or later (aOR = 2.62; 95% CI: 1.58–4.35), and foetal birthweight greater than 4000 g (aOR = 1.93; 95% CI: 1.30–2.87). Compared with those without these conditions, the risk of uterine rupture during VBAC among women with amniotic fluid embolism, severe anaemia, placenta accreta spectrum, placental abruption, preeclampsia or eclampsia, and mild anaemia was 25.7-fold, 15.89-fold, 4.17-fold, 3.96-fold, and 2.49-fold higher, respectively. The incidence of adverse maternal outcomes during VBAC was higher in women with uterine rupture than in women without. Conclusion The incidence of uterine rupture during VBAC is comparable between China and some developed countries. In the clinical medical practice of obstetrics, it is necessary to be vigilant to factors associated with uterine rupture during VBAC and identify uterine rupture as soon as possible to improve maternal and perinatal outcomes.

Summary Background Preterm birth rates have increased significantly worldwide over the past decade. Few epidemiological studies on the incidence of preterm birth and temporal trends are available in China. This study used national monitoring data from China's National Maternal Near Miss Surveillance System (NMNMSS) to estimate the rate of preterm birth and trends between 2012 and 2018 in China and to assess risk factors associated with preterm birth. Methods In this observational study, data were sourced from the NMNMSS between Jan 1, 2012, and Dec 31, 2018. Pregnancies with at least one livebirth, with the baby born at 28 weeks of gestation or more or 1000 g or more birthweight were included. We estimated the rates of overall preterm, very preterm (born between 28 and 31 weeks’ gestation), moderate preterm (born between 32 and 33 weeks’ gestation), and late preterm (born between 34 and 36 weeks’ gestation) births in singleton and multiple pregnancies and assessed their trends over time. We used logistic regression analysis to examine the associations between preterm birth and sociodemographic characteristics and obstetric complications, considering the sampling strategy and clustering of births within hospitals. Interrupted time series analysis was used to assess the changes in preterm birth rates during the period of the universal two child policy intervention. Findings From Jan 1, 2012, to Dec 31, 2018, 9 645 646 women gave birth to at least one live baby, of whom 665 244 (6·1%) were born preterm. In all pregnancies, the overall preterm birth rate increased from 5·9% in 2012 to 6·4% in 2018 (8·8% increase; annual rate of increase [ARI] 1·3 [95% CI 0·6 to 2·1]). Late preterm births (8·8%; ARI 1·5% [0·9 to 2·2]) and very preterm births (13·3%; ARI 1·8% [0·5 to 3·0]) significantly increased from 2012 to 2018, whereas moderate preterm births did not (3·8%; ARI 0·3% [95% CI –0·9 to 1·5]). In singleton pregnancies, the overall preterm birth rate showed a small but significant 6·4% increase (ARI 1·0% [0·4 to 1·7]) over the 7 year period. In multiple pregnancies, the overall preterm birth rate significantly increased from 46·8% in 2012 to 52·7% in 2018 (12·4% increase; ARI 1·9% [1·2 to 2·6]). Compared with women who gave birth in 2012, those who gave birth in 2018 were more likely to be older (aged ≥35 years; 7·4% in 2012 vs 15·9% in 2018), have multiples (1·6% vs 1·9%), have seven or more antenatal visits (50·2% vs 70·7%), and have antepartum complications and medical disease (17·9% vs 35·1%), but they were less likely to deliver via caesarean section (47·5% vs 45·0%). Compared with the baseline period (January, 2012 to June, 2016), a higher increase in preterm birth was observed after the universal two child policy came into effect in July, 2016 (β=0·034; p=0·03). Interpretation An increase in preterm births was noted for both singleton and multiple pregnancies between 2012 and 2018 in China. China's strategic investment in maternal and neonatal health has been crucial for the prevention of preterm birth. Due to rapid changes in sociodemographic and obstetric factors related to preterm birth—particularly within the context of the universal two child policy—such as advanced maternal age at delivery, maternal complications, and multiple pregnancies, greater efforts to reduce the burden of preterm birth are urgently needed. Funding National Key R&D Program of China, National Health Commission of the People's Republic of China, China Medical Board, WHO, and UNICEF.

It is unclear whether there are different body mass index (BMI) trajectories among a population with normal BMI levels, and the association between BMI patterns and incident hypertension is not well characterized. This prospective cohort study includes surveys conducted at baseline and three follow‐ups. 3939 participants who are free of hypertension at baseline or first two follow‐ups were enrolled. At baseline, the age of participants ranged from 35 to 82 years and the mean age was 45.9 years. The BMI trajectories were identified using latent mixture modeling with data from the baseline and first two follow‐ups. The effects of different BMI trajectories on the development of hypertension were analyzed using a Cox proportional hazard model. Four distinct BMI trajectories were identified over the study period (2004‐2010): normal‐stable (n = 1456), normal‐increasing (n = 2159), normal‐fluctuated (n = 166), and normal‐sharp‐increasing (n = 158). Relative to the normal‐stable BMI group, the hazard ratios (HRs) and 95% confidence intervals (CIs) after adjustment for confounding factors of the normal‐increasing, normal‐fluctuated, and normal‐sharp‐increasing groups were 1.244 (1.103‐1.402), 1.331 (1.008‐1.756), and 1.641 (1.257‐2.142), respectively. Additionally, subgroup analysis showed that the normal‐fluctuated BMI trajectory was associated with a significantly higher risk of hypertension only in women (HR = 1.362; 95% CI = 1.151‐1.611). The BMI trajectories were significant predictors of hypertension incidence, and increasing BMI trajectories within the currently designated normal range were associated with an increased hypertension risk, especially in women.

The purpose of our study was to explore the association of blood pressure (BP) changes on short-and long-term outcomes of major adverse cardiovascular events (MACEs) in rural China. This study was designed to learn the effects of BP changes (2004-2008) on short-term (2008-2010, within 2 years of the initial examination) and long-term (2008-2017) outcomes of MACE, including 24 285 and 27 290 participants, respectively. In this study, 423 (short-term) and 1952 (long-term) MACEs were identified. For prehypertension to hypertension, the risk of long-term stroke was increased (hazard ratio [HR] = 1.18 [1.00-1.39]). For hypertension to prehypertension, the short-term MACE risk (0.65 [0.47-0.90]), short-term stroke risk (0.45 [0.26-0.76]), and long-term stroke risk (0.83 [0.70-0.99]) all decreased. Short-term outcomes conferred a stronger impact than long-term outcomes (Fisher Z test, measured as the difference of β coefficients, all P < .05).

This study aimed to assess the impact of the 2017 American College of Cardiology and American Heart Association (ACC/AHA) guideline and the 2018 Chinese hypertension guidelines on the different secular trends for hypertension prevalence. A total of 82 665 eligible individuals aged ≥20 years were selected from nine cross‐sectional study periods (1991‐2015) from the China Health and Nutrition Survey (CHNS). Over the 24‐year period, the long‐term trend for the prevalence of the 2017 ACC/AHA‐defined age‐adjusted hypertension showed an increase from 32.2% (95% confidence interval (CI): 31.0%‐33.3%) in 1991 to 60.0% (95% CI: 58.6%‐61.3%) in 2015 (P trend

Systolic blood pressure increased in middle-aged person contributes significantly to the risk of major adverse cardiovascular events (MACE). Meanwhile, different patterns (short- or long-term change) of SBP increase may result in differential risk and lead to differences in predictive ability.A total of 19,544 and 22,610 participants in the Fuxin Cardiovascular Cohort Study underwent measurement of SBP at 2 examinations for short- and long-term change study population. Cox proportional hazards models were used to relate future clinical outcomes with change in SBP.During a median follow-up period of 12.5 years, 1064 (772 stroke, 247 myocardial infarction, 528 CVD deaths) and 1316 (958 stroke, 301 myocardial infarction, 660 CVD deaths) MACE were identified during short- and long-terms SBP change, respectively. For SBP increased participants, short-term change in SBP was associated with future MACE (hazard ratio [HR]: 1.241 per 1-SD increase; 95% confidence interval [CI]: 1.146-1.344; P 0.001), long-term change in SBP (HR: 1.218; 95% CI: 1.123-1.322; P 0.001). For prehypertension participants, long-term changes conferred a strong impact than short-term. For hypertensive participants, short-term changes conferred a strong impact than long-term.Having a SBP rise in short- or long-term both confer an increased risk of MACE and its subgroups. Furthermore, short- and long-term SBP increase patterns adds different additional information beyond one single baseline examination. Change in SBP may be a prognostic surrogate marker and future studies are needed to clarify the possible mechanism for predicting MACE.

OBJECTIVES The 2017 American College of Cardiology/American Heart Association (ACC/AHA) Guideline for high blood pressure (BP) in adults redefined hypertension as SBP at least 130 mmHg or DBP at least 80 mmHg. However, the optimal BP for different BMI population to reduce stroke incidence is uncertain. METHODS A prospective cohort study was designed by four examinations: baseline (2004-2006), 2008, 2010 and 2017 follow-up. The study group composed of 36 352 individuals, to determine the ideal BP range to reduce stroke incidence of two BMI level, adjusted Cox proportional hazards models were utilized to establish the associations between SBP/DBP and the risk of stroke incident. Then, the restricted cubic spline regression was applied to find the ideal range of SBP/DBP values for two kinds of BMI categories definitions. RESULTS During a median follow-up period of 12.5 years, 2548 (7.0%) nonstroke individuals at baseline developed incident stroke. After fully adjusting confounding factors, SBP (per 20 mmHg increase) and DBP (per 10 mmHg increase) are independently associated with the risk of stroke incidence [SBP, hazard ratio = 1.277, 95% confidence interval (95% CI), 1.217-1.340, P

Background. The 2017 American College of Cardiology and American Heart Association hypertension guideline updated stage 1 hypertension definition as systolic blood pressure range from 130 to 139 mmHg or diastolic blood pressure from 80 to 89 mmHg. However, the association of stage 1 hypertension with stroke and its subtypes among the older population in rural China remains unclear. Methods. This population-based cohort study consisted of 7,503 adults aged ≥60 years with complete data and no cardiovascular disease at baseline from rural areas of Fuxin County, Liaoning province, China. Follow-up for the new cases of stroke was conducted from the end of the baseline survey to the end of the third follow-up survey (January 1, 2007–December 31, 2017). Adjusted Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals with the normal blood pressure as a reference, and calculated population attributable risk was based on prevalence and hazard ratios. Results. During a median follow-up of 12.5 years, we observed 1,159 first-ever incident stroke (774 ischemic, 360 hemorrhagic, and 25 uncategorized). With the blood pressure Conclusion. Among adults aged ≥60 years in rural China, stage 1 hypertension defined by 2017 American College of Cardiology and American Heart Association hypertension guideline was independently associated with the increased risk of all stroke and ischemic stroke, excluding hemorrhagic stroke.

Lockwire segmentation plays a vital role in ensuring mechanical safety in industrial fields. Aiming at the missed detection problem encountered in blurred and low-contrast situations, we propose a robust lockwire segmentation method based on multiscale boundary-driven regional stability. We first design a novel multiscale boundary-driven stability criterion to generate a blur-robustness stability map. Then, the curvilinear structure enhancement metric and linearity measurement function are defined to compute the likeliness of stable regions to belong to lockwires. Finally, the closed boundaries of lockwires are determined to achieve accurate segmentation. Experimental results demonstrate that our proposed method outperforms state-of-the-art object segmentation methods.

Background With the development of assisted reproductive technology, the twinning rate in China has been increasing. However, little is known about twinning from 2014 onwards. In addition, previous studies analysing optimal gestational times have rarely considered maternal health conditions. Therefore, whether maternal health conditions affect the optimal gestational time remains unclear. Methods Data of women delivered between January 2012 and December 2020 were collected through China’s National Maternal Near Miss Surveillance System. Interrupted time series analysis was used to determine the rates of twinning, stillbirth, smaller than gestational age (SGA), and low Apgar scores ( Results There were 442,268 infants enrolled in this study, and the adjusted rates for twinning, stillbirth, SGA, and low Apgar scores were 3.10%, 1.75%, 7.70%, and 0.79%, respectively. From 2012 to 2020, the twinning rate showed an increasing trend. Adverse perinatal outcomes, including stillbirth, SGA, and low Apgar scores showed a decreasing trend. A gestational age between 34 and 36 weeks decreased most for rate of stillbirth (average changing rate -9.72%, 95% confidence interval [CI] -11.41% to -8.00%); and a gestational age of between 37 and 38 weeks decreased most for rates of SGA (average changing rate -4.64%, 95% CI -5.42% to -3.85%) and low Apgar scores (average changing rate -17.61%, 95% CI -21.73% to -13.26%). No significant difference in changes in twinning rate or changes of each perinatal outcome was observed during periods of different fertility policies. Infants born at 37 weeks of gestation had a decreased risk of stillbirth, SGA, and low Apgar scores. Maternal antepartum or medical complications increased the risk of SGA and low Apgar scores in different gestational weeks. Conclusion China’s twinning rate showed an increasing trend, while adverse perinatal outcomes decreased from 2012 to 2020. Fertility policy changes have had little effect on the twinning rate or the rate of adverse perinatal outcomes such as stillbirth, SGA, or low Apgar scores. The optimal gestational age for twins was 37 weeks. Women pregnant with twins and with antepartum or medical complications should be cautious due to an increased risk of SGA and low Apgar scores.

The relationship between serum spermidine levels and future cardiovascular disease risk has not yet been well elucidated in the general population based on community studies. Using a nested case-control study, we estimated the association between serum spermidine level and future stroke. New stroke cases had higher baseline levels of spermidine than controls [182.8 (141.8–231.5) vs. 152.0 (124.3–193.0), P < 0.001]. After multivariable adjustment, individuals with spermidine ≥ 205.9 nmol/L (T3) higher risks of stroke (HR 5.02, 95% CI 1.58–16.02) with the lowest quartile (< 136.9 nmol/L) as reference. The association between serum spermidine levels and risk of stroke seemed to be consistent and was reproducible in our cross-sectional studies. In addition, comparisons of the areas under receiver operator characteristics curves confirmed that a model including spermidine had better discrimination than without (0.755 vs. 0.715, P = 0.04). Here we report a close relationship exists between serum spermidine levels and risk of stroke.

Preliminary evidence from China and other countries has suggested that coronavirus disease 2019 (COVID-19) mitigation measures have caused a decline in preterm births, but evidence is conflicting. Utilising a national representative data of 11,714,947 pregnant women in China, we explored the immediate changes in preterm birth rates during the COVID-19 mitigation period using an interrupted-time-series analysis. We defined the period prior to February 1, 2020 as the baseline, followed by the COVID-19 mitigation stage. In the first month of the COVID-19 mitigation, a significant absolute decrease in preterm birth rates of 0.68% (95%CI:−1.10% to −0.26%) in singleton, and of 2.80% (95%CI:−4.51% to −1.09%) in multiple births was noted. This immediate decline in Wuhan was greater than that at the national level among singleton births [−2.21% (95%CI:−4.09% to −0.34% vs. −0.68%)]. Here we report an immediate impact of COVID-19 mitigation measures on preterm birth in China.

Background The goal of this study was to investigate whether pregnancy complications are associated with an increased risk of uterine rupture (UR) and how that risk changes with gestational age. Methods We obtained all data from China’s National Maternal Near Miss Surveillance System (NMNMSS) between 2012 and 2018. Poisson regression analysis was used to assess the risk of UR with pregnancy complications (preeclampsia, gestational diabetes mellitus, placental abruption, placenta previa and placenta percreta) among 9,454,239 pregnant women. Furthermore, we analysed the risks of UR with pregnancy complications in different gestational age groups. Results The risk of UR was increased 2.0-fold (1.2-fold to 2.7-fold) in women with pregnancy complications (except for preeclampsia). These associations also persisted in women without a previous caesarean delivery. Moreover, an increased risk of UR before term birth was observed among women with gestational diabetes mellitus, placental abruption and placenta percreta. The risk of UR was slightly higher in women with gestational diabetes mellitus who had a large for gestational age (LGA) foetus, especially at 32 to 36 weeks gestation. Conclusions The risk of UR is associated with gestational diabetes mellitus, placental abruption, placenta previa and placenta percreta, but varies in different gestational ages.

We aimed to describe the characteristics of adolescent pregnancy, determine its effect on adverse maternal and perinatal outcomes and explore whether that association varies with gestational age with the goal of proposing specific recommendations for adolescent health in China. This study included 2,366,559 women aged 10–24 years who had singleton pregnancies between 2012 and 2019 at 438 hospitals. Adolescent pregnancy was defined as younger than 20 years of age. We used multivariable logistic regression to estimate the effects. Women aged 20–24 years served as the reference group in all analyses. The proportion of rural girls with adolescent pregnancies rebounded after 2015 even though common-law marriage in rural areas decreased. Higher risks of eclampsia (adjusted odds ratio (aOR) 1.87, 95% confidence interval (CI) 1.57 ~ 2.23), severe anaemia (aOR 1.18, 95% CI 1.09 ~ 1.28), maternal near miss (MNM; aOR 1.24, 95% CI 1.12 ~ 1.37), and small for gestational age (SGA; aOR 1.30, 95% CI 1.28 ~ 1.33) were observed when gestational age was > 37 weeks. Adolescent pregnancy was independently associated with increased risks of other perinatal outcomes. Further implementation of pregnancy prevention strategies and improved health care interventions are needed to reduce adolescent pregnancies and prevent adverse fertility outcomes among adolescent women in China at a time when adolescent fertility rate is rebounding.

This study aimed to investigate the effect of body mass index (BMI) changes on hypertension among rural areas of China. A population-based sample of 13,263 and 5944 rural Chinese people aged ≥35 years and without hypertension at baseline was included in our analysis of BMI changes (from (2004-2006) to 2008) and short- and long-term outcomes of hypertension (from 2008 to 2010 and 2010 to 2017). The participants were divided into four groups by a comprehensive cross-sectional combination according to baseline BMI (18.5-24 vs. ≥24 kg/m2) and follow-up changes (decreased vs. increased). Adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs). During a median follow-up period of 4.8 (short-term) and 11.7 (long-term) years, 2299 (17.33%) and 2020 (33.98%) participants developed hypertension, respectively. For participants with a baseline BMI ≥ 24 kg/m2, when BMI decreased in follow-ups, the multivariable-adjusted HRs (95% CI) of short-term hypertension were 0.898 (0.857-0.942). For baseline 18.5 kg/m2 ≤ BMI < 24 kg/m2, when BMI increased in follow-ups, the risks of short-term hypertension were 1.103 (1.068-1.139). We detected that BMI changes had a lower impact on the incidence of hypertension in long-term than short-term. Our study indicated that BMI changes were significantly associated with the incidence of hypertension for the short-term, and it had a stronger impact on short-term outcomes than long-term. Managing weight by lifestyle modification was particularly important for the primary prevention of hypertension in rural Chinese population.

This study was performed to investigate the association between stage 1 hypertension defined by the 2017 ACC/AHA guidelines and the risk of adverse events among adults aged 35 to 49 years. A total of 20,072 adults aged 35–49 years, without a history of cardiovascular disease (CVD) at baseline were included in the present study. Adjusted Cox proportional hazards models were applied to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). During a median follow-up period of 12.5 years, the results indicated that 777 subjects suffered all-cause death and 299 subjects developed CVD. A total of 830 subjects were involved in incident stroke and 141 subjects had a myocardial infarction (MI). Stage 1 hypertension had a HR (95% CI) of 1.38 (1.13–1.70) for all-cause mortality, 1.74 (1.20–2.53) for CVD mortality, 1.78 for (1.40–2.26) for stroke incidence, and 1.64 (0.99–2.71) for MI incidence, respectively, compared with blood pressure (BP)

Background Elevated blood pressure (BP) is closely related to stroke and its subtypes. However, different time periods changes in BP may result in differential risk of stroke. Hypothesis Short‐term blood pressure changes have a more strong impact on stroke and its subtypes than long‐term blood pressure changes. Methods We designed the study on the effects of short‐ (2008‐2010) and long‐term (2004‐2010) BP changes on stroke events (2011‐2017), including 22 842 and 28 456 subjects, respectively. The difference in β coefficients between short‐ and long‐term BP changes on the effects of stroke were examined using the Fisher Z test. Results During a median 12.5‐year follow‐up period, 1014 and 1505 strokes occurred in short‐ and long‐term groups. In short‐term group, going from prehypertension to hypertension, the risk of stroke events increased (stroke: hazard ratio [HR] = 1.537 [1.248‐1.894], ischemic stroke: 1.456 [1.134‐1.870] and hemorrhagic stroke: 1.630 [1.099‐2.415]); going from hypertension to prehypertension, the risk of stroke events decreased (stroke:0.757 [0.619‐0.927] and hemorrhagic stroke:0.569 [0.388‐0.835]). Similarly, in long‐term group, going from prehypertension to hypertension, individuals had an increased risk of stroke (1.291, 1.062‐1.569) and hemorrhagic stroke (1.818, 1.261‐2.623); going from hypertension to prehypertension, participants had a decreased risk of stroke (0.825, 0.707‐0.963) and hemorrhagic stroke (0.777, 0.575‐0.949). Furthermore, the effects of BP changes during short‐term period on stroke events were greater than that in long‐term period. Conclusions Short‐ and long‐terms BP changes were both associated with the risk of stroke events. Furthermore, short‐term BP changes had a stronger impact than did long‐term changes on risk of stroke events.

Polyethylene/Polypropylene (PE/PP) composite non-woven fabrics have been used widely for surgical packages due to its dual features of PE surface and PP surfaces. PP fabric pre-treated by hydrophilic agent provides high water absorbency, while PE surface is responsible for high barrier functions. However, the PP water absorbency declines once PE film is laminated, and no report devoted to study the extent and the reasons of this declining. Herein, the hydrophilic finishing of the PP non-woven fabrics was processed via Kiss-roll method, then the PE/PP fabrics were obtained using a normal hot melt adhesive PE film laminating process. The wicking height, water absorption specific gravity (LAC%), static contact angle, as well as the complete wetting time of the finished PP and PE/PP fabric were measured and compared. Meanwhile, the SEM was used to detect the morphology changing. The results revealed that the pores between fibers in the PP non-woven were filled with non-hydrophilic hot melt adhesive penetrated during PE lamination, so that the PP structure changed to be less porous. Moreover, the laminated PP layer actually blocks the water flow channel in the system, resulting in the absorbency reduction after lamination. As a result, comparing with the PP non-woven fabric, the wicking height of the PE/PP fabric decreased by 25.3 %, the LAC % value reduced by 40.83 %, and the complete wetting time extended from 0.29 s to 1.74 s.

In this paper, the compound hot-melt adhesives were prepared by blending alkyl sulfonate polymer antistatic agent with modified rosin hot-melt adhesive and used for the preparation of polyethylene film/polypropylene-coated non-woven fabrics. The effects of the amount of antistatic agent on the melt viscosity, softening point, and thermal stability of the compounded hot-melt adhesives were studied. Then, the antistatic properties and its washing fastness of the coated non-woven fabrics were tested and analyzed. The results showed that the softening point and the melt viscosity of the hot-melt adhesives decreased after compounding, and the thermal stability of the compound hot-melt adhesives decreased in the high temperature range, which was not affected before 200℃. The surface inductive voltage, half-life, and specific resistance of the coated non-woven fabrics prepared from the compound adhesives decreased gradually with the increase of the amount of the antistatic agent, indicating that the antistatic property of the prepared fabrics was gradually improved. In addition, the fabrics still exhibited antistatic properties after soaping for several times. The influence of compound adhesive on the wettability of fabric surface was consistent with that of antistatic property. Finally, the mechanism of the hot-melt adhesive and antistatic agent compounding technology to improve the antistatic performance of the coated non-woven fabrics was elaborated, and the reason for its excellent soaping durability was also explained.

Bolt-loosening can cause poor running quality of trains, even resulting in terrible accidents. Currently, existing bolt-loosening detection methods for running trains need 3D data of the whole train body, extremely decreasing the efficiency of fault detection. In this paper, we propose a fast bolt-loosening detection method for the running train's key components based on binocular vision. Since a train generally consists of many cars with the same structure, the position distribution of train's key components is regular and periodic. First, we propose a novel method to detect key component regions including bolts, taking full advantage of this periodic distribution rule. Second, the sub-pixel edges of the bolt cap and mounting surface in the localized regions are extracted and segmented, respectively, combining with the convolutional neural network (CNN). Finally, based on stereo matching and the binocular vision model, the 3D data of these edges are obtained to calculate the distance between the bolt cap and mounting surface. By comparing the calculated distance with the reference value, we can judge whether bolt-loosening has occurred. The experimental results indicate that multi-bolt looseness can be calculated simultaneously. The measurement repeatability and precision are superior to 0.03 and 0.08 mm, respectively, and the relative error is less than 1.42%.

Background Waist circumference (WC) and uric acid (UA) are significantly related. Still, their temporal sequence and how the sequence works on future risk of triglyceride glucose (TyG) are unknown, especially in the Chinese population. Methods Cross-lagged panel model was used to analyze the reciprocal, longitudinal relationships among a set of interrelated variables. The mediation model was constructed to test the effect of the relationship between WC and UA on TyG. Results A total of 5727 subjects were enrolled in our study population, of which 53.5% were women, and the mean age was 59.0 (standard deviation, 8.62) years. After adjusting for traditional confounding factors, the results showed that a higher level of baseline WC was significantly associated with a higher level of follow-up UA (β = 0.003, P = 0.031) and follow-up TyG (β = 0.003, P < 0.001);. Simultaneously, there was no statistical association between the level of baseline UA and the level of follow-up WC (β = − 0.009, P = 0.951). The mediation effects of UA on WC-TyG were estimated to be 18.1% in adults, and 36.2% in women. Conclusions The current study demonstrated that higher baseline level of WC probably preceded UA’ level in general population. In addition, UA mediated the relationship of WC to TyG, especially in females. And the possible mechanism would require further clarification.

To investigate whether pregnancy complications are associated with increased risk of UR and how that risk changes with gestational age. We obtained all data from China’s National Maternal Near Miss Surveillance System (NMNMSS) between 2012 and 2018. Poisson regression analysis was used to assess the risk of UR with pregnancy complications (preeclampsia, gestational diabetes mellitus, placental abruption, placenta previa and placenta accreta) among 9,502,250 pregnant women. Furthermore, we analyzed the risks of UR with pregnancy complications in different gestational age groups. Compared to women without pregnancy complications, those with different complications (except for preeclampsia) had a 1- to 3-fold greater risk of UR. These associations also persisted in women without previous cesarean delivery. Women with placental abruption or placenta accreta had an increased risk of UR in all gestational age groups, while the increased risk of UR among women with placenta previa was only observed at term. Moreover, an increased risk of UR among women with gestational diabetes mellitus was only observed at 32 to 36 weeks gestation and increased with the offspring’s birth weight. Better quality antenatal care and early intervention for women with these pregnancy complications are needed to minimize the incidence of UR.

We aimed to describes characteristic of adolescent pregnancy, determines its effect on adverse maternal and perinatal outcomes and explores whether that association varies with gestational age with the goal of proposing specific recommendations for adolescent health in China. 2,366,559 women aged 10-24 years who had singleton pregnancies between 2012 and 2019 from 438 hospitals were included in the study. Adolescent pregnancy was defined as younger than 20 years of age. We used multivariable logistic regression to estimate the effect. Women aged 20-24 years served as the reference group in all analyses. The proportion of rural girls with adolescent pregnancies rebounded after 2015 despite common-law marriage in rural areas have improved. Higher risks of eclampsia (adjusted odds ratio (aOR) 1.87, 95% confidence interval (CI) 1.57~2.23), severe anaemia (aOR 1.18, 95% CI 1.09~1.28), maternal near miss (aOR 1.24, 95% CI 1.12~1.37), and small-for-gestational-age (aOR 1.30, 95% CI 1.28~1.33) were observed when gestational age was > 37 weeks. Adolescent pregnancy was independently associated with increased risks of other perinatal outcomes. Further implementation of pregnancy prevention strategies and improved health care interventions are needed to reduce adolescent fertility and to avoid adverse fertility outcomes among adolescent women in China at a time when adolescent fertility is rebounding.

The star formation activity of the host galaxies of active galactic nuclei (AGNs) provides valuable insights into the complex interconnections between black hole growth and galaxy evolution. A major obstacle arises from the difficulty of estimating accurate star formation rates in the presence of a strong AGN. Analyzing the $1-500\, \mu m$ spectral energy distributions and high-resolution mid-infrared spectra of low-redshift ($z < 0.5$) Palomar-Green quasars with bolometric luminosity $\sim 10^{44.5}-10^{47.5}\rm\,erg\,s^{-1}$, we find, from comparison with an independent star formation rate indicator based on [Ne II] 12.81$\, \mu m$ and [Ne III] 15.56$\, \mu m$, that the torus-subtracted, total infrared ($8-1000\, \mu m$) emission yields robust star formation rates in the range $\sim 1-250\,M_\odot\,{\rm yr^{-1}}$. Combined with available stellar mass estimates, the vast majority ($\sim 75\%-90\%$) of the quasars lie on or above the main sequence of local star-forming galaxies, including a significant fraction ($\sim 50\%-70\%$) that would qualify as starburst systems. This is further supported by the high star formation efficiencies derived from the gas content inferred from the dust masses. Inspection of high-resolution Hubble Space Telescope images reveals a wide diversity of morphological types, including a number of starbursting hosts that have not experienced significant recent dynamical perturbations. The origin of the high star formation efficiency is unknown., Comment: 17 pages, 5 figures, 2 tables. Accepted for publication in ApJ

Background To examine the association between the Apgar score and neonatal mortality over gestational age in China and to explore whether this association changed when Apgar scores were combined at 1 and 5 min. Methods Data for all singleton live births collected from 438 hospitals between 2012 and 2016 were used in this study. Poisson regression with a robust variance estimator adjusted for a complete set of confounders was used to describe the strength of the association between the Apgar score and neonatal mortality. Results The relative risks of neonatal death-associated intermediate Apgar score at 5 min peaked at 39–40 weeks of gestation and subsequently decreased if the gestational age increased to 42 weeks or above, in contrast to the low Apgar score. Among both preterm and term new-borns with Apgar scores at 5 min, new-borns that were not small for gestational age had a lower mortality rate than those that were small for gestational age. The association between Apgar score and the neonatal mortality was even stronger when scores at 1 and 5 min were combined. Conclusions Apgar score is not only meaningful for preterm new-borns but also useful for term new-borns, especially term new-borns that are not small for gestational age. Once the baby’s Apgar score worsens, timely intervention is needed. There is still a gap between China and high-income countries in terms of sustained treatment of new-borns with low Apgar scores.

BackgroundWaist circumference (WC) and uric acid (UA) are significantly related. Still, their temporal sequence and how the sequence works on future risk of insulin resistance (IR) are unknown, especially in the Chinese population. MethodsCross-lagged panel model was used to analyze the reciprocal, longitudinal relationships between a set of inter-related variables. The mediation model was constructed to test the impact of the relationship between WC and UA on IR.ResultsA total of 5,727 subjects in our study population were enrolled, of which 53.5% were women, and the mean age was 59.0 (SD, 8.62) years. After adjusting for traditional confounding factors, we found that a higher level of baseline WC was significantly associated with a higher level of follow-up UA (β = 0.003, P = 0.031) and follow-up triglycerides glucose index (TyG) (β = 0.003, P < 0.001);. Simultaneously, there was no statistical association between the level of baseline UA and the level of follow-up WC (β = -0.009, P = 0.951). Besides, the cross-lagged panel model showed that the baseline WC had influenced the level of follow-up UA. The mediation effects of UA on WC-IR were estimated to be 18.1% in general adults, and 36.2% in women.ConclusionsThe current study demonstrated that the higher WC levels probably preceded UA in general population, and UA mediated the relationship of WC to TyG, especially among females. However, the mediation effect was different between men and women, and the possible mechanism would require further clarification.

Background: With the increasing need to explore the association between interpregnancy interval (IPI) and adverse maternal and neonatal outcome, numerous studies have been conducted worldwide. However, national reports of the IPI in China are lacking. Furthermore, except for age as a known factor for IPI and adverse maternal and neonatal outcomes, the effect of gestational age in previous pregnancy is unknown. The aim of this study was to determine the IPI distribution between 2010 and 2019 and identify the effect of IPI and gestational age in previous pregnancy on adverse maternal and neonatal outcomes in China. Methods: We used individual data from China's National Maternal Near Miss Surveillance System (NMNMSS) between 2010 and 2019. The surveillance system collected data prospectively on all pregnant and postpartum women admitted to the obstetric department. The analysis was restricted to women with records of at least two consecutive singleton births and without any complication that the NMNMSS collected during their previous pregnancy. Multivariable generalized linear models with the restricted cubic spline (RCS) were used to evaluate the effect of IPI on each adverse neonatal and maternal outcome on different categories of gestational age in previous pregnancy. Further analysis was performed in subgroups categorized by the gestational age of previous pregnancy. Results: Over the study period, 408,843 women with 420,810 pregnancies were enrolled in our study. The median and quartile range of IPI was 32 [22, 47] months. Few women (49,084, 11.67%) became pregnant again within an extremely short (≤6 months) or long (≥60 months) IPI, and over half (289,846, 68.88%) of the women became pregnant again after an IPI between 7 and 42 months. The risk of large for gestational age (LGA), Gestational Diabetes Mellitus (GDM) and gestational hypertension was increased with increased IPI, while the risk of spontaneous preterm and small for gestational age (SGA) was inversely decreased with increased IPI. The relationship between IPI and all the other adverse neonatal and maternal outcomes was in a “U” shape. The risk of adverse neonatal and maternal outcomes differs between subgroups stratified by gestational age in the previous pregnancy. The risk of spontaneous preterm and abortion at short IPI, iatrogenic preterm, GDM, preeclampsia or eclampsia and gestational hypertension at long IPI increased more when women were of a greater gestational age in the previous pregnancy. Conclusions: This was the first comprehensive exploration of the IPIs of Chinese women from a national database. In this research, both extreme short and long IPI were associated with a higher risk of adverse maternal and neonatal outcomes. The gestational age in the previous pregnancy was also a determinant factor for the adverse maternal and neonatal outcomes in subsequent pregnancies. Funding Statement: This study was supported by the National Key R&D Program of China (Grant No. 2019YFC1005100), the National Health Commission of the People’s Republic of China, the China Medical Board (Grant No. 11-065), the WHO (Grant No. CHN-12-MCN-004888), and UNICEF (Grant No. 2016EJH016). Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: This study was approved by the ethics committee of the West China Second University Hospital.

Additional file 3. The relative risks in different parity and previous caesatean section of women by age, China.