Tobacco smoke and all-cause mortality and premature death in China: a cohort study.

BACKGROUND: Tobacco smoke is associated with several diseases, and identified as the second leading risk factor for death from any cause worldwide. The relationship of tobacco smoke to mortality or premature death is not yet available from contemporary cohorts after 2010 in China. This study aimed to investigate the smoking behavior and the relationship of tobacco smoke to mortality and premature death among a nationally representative cohort starting from 2011 in China. METHODS: The nationally representative datasets (China Health and Retirement Longitudinal Study, CHARLS, 2011-2012) was employed and linked with follow-up data (2013). CHARLS was an ongoing nationally representative survey, which longitudinally followed up subjects aged over 45 years. Smoking status (non-smoker, ex-smoker, smoker, pack-years of smoking, age at starting and ceasing smoking) was used as independent variable, and all-cause mortality, premature death (defined as mortality before age 72.7 years in men and 76.9 years in women) were used as dependent variables. The Cox's proportional hazards regression mode was used to estimate the effect of tobacco smoke and pack-years of smoking on all-cause mortality and premature death. RESULTS: A total of 16,701 subjects were included. The association between tobacco smoker (hazard ratio [HR] = 1.37, 95%CI = 1.02, 1.83) / ex-smoker (HR = 1.75, 95%CI = 1.24, 2.46) and all-cause mortality was significant. Tobacco smoker (HR = 1.58, 95%CI = 1.04, 2.39) and ex-smoker (HR = 2.25, 95%CI = 1.38, 3.66) was associated with increase in the risk of premature death. Pack-years of smoking ≥ 30 was associated with increased risk of premature death compared with non-smokers in total (HR = 1.59, 95%CI = 1.03, 2.43) and women (HR = 3.38, 95%CI = 1.22, 9.38). Additionally, our results also revealed that there was a linear trend between pack-years of smoking and premature death in total (P = 0.002) and women (P = 0.010). CONCLUSION: This study found a negative effect of smoking status on all-cause mortality and premature death among a contemporary and nationally representative data in China. The correlation between pack-years of smoking and premature death and the trend of pack-years of smoking with premature death was also identified.

Examining the potential impacts of intensive blood pressure treatment on the socioeconomic inequity in hypertension prevalence in China: a nationally representative cross-sectional study.

Few studies focused on the equity of hypertension prevalence before and after the diagnostic threshold change. The study aimed to analyze the 130/80 mmHg hypertension diagnostic threshold on the equity of hypertension prevalence in China. The baseline survey data from the China Health and Retirement Longitudinal Study (CHARLS) conducted from 2011 to 2012 were utilized to evaluate the impact of the 130/80 mmHg diagnostic threshold on the equity of hypertension prevalence in China using the concentration index and its decomposition which was an index reflecting the health inequality caused by social and economic factors. The prevalence of hypertension was 41.56% and 57.33% under the diagnostic thresholds of 140/90 mmHg and 130/80 mmHg, respectively. The concentration index for hypertension prevalence in China was -0.017 (95%CI: -0.028, -0.006) under the 140/90 mmHg threshold and -0.010 (95%CI: -0.018, -0.002) under the 130/80 mmHg threshold. Concentration index decomposition analysis of hypertension prevalence diagnosed at both diagnostic thresholds showed that age, BMI, and economic status contributed more to the inequitable situation of hypertension prevalence. Higher age, higher BMI, and poorer economic status increased the inequity of hypertension prevalence. No significant difference in the increase in hypertension among individuals of different economic status after implementing the blood pressure control standard (130/80 mmHg), and the prevalence of hypertension in the region did not show a significant bias towards the low economic status population. Therefore, implementing this standard will not increase the risk of hypertension prevalence biased toward people of low economic status. Implementing the 130/80 mmHg diagnostic threshold will not increase the risk of hypertension prevalence biased towards people of low economic status.

Is Increasing Diet Diversity of Animal-Source Foods Related to Better Health-Related Quality of Life among Chinese Men and Women?

Diet plays a crucial role in regulating individuals' lifestyles and is closely related to health. The intake of animal-sourced foods (ASF) provides the human body with high-quality protein and various micronutrients. This study aimed to investigate whether the diversity of animal foods has a positive impact on the health-related quality of life (HRQoL) among residents. The data came from the Shaanxi baseline survey of the Northwest Chinese Regional Ethnic Cohort Study, which recruited more than 100 thousand participants aged 35 to 74 from five provinces between June 2018 and May 2019. A total of 39,997 participants in Shaanxi (mean age: 50 years; 64% women) were finally included in this current study. The animal source food diet diversity score (ASFDDS) was established based on the frequency of consuming pork, mutton, beef, poultry, seafood, eggs, pure milk, and yogurt. The physical component score (PCS) and mental component score (MCS), ranging from 0 to 100 on the 12-Item Short Form Survey (SF-12), were used to assess participants' HRQoL. Better PCS/MCS was defined as scores higher than the 90th percentile. The results showed that men had a higher intake of ASF and ASFDDS than women. After adjusting for potential confounders, compared with those who never or rarely consumed animal foods, the likelihood of having better PCS and MCS increased by 16% (OR = 1.16, 95%CI: 1.01-1.34) and 24% (OR = 1.24, 95%CI: 1.03-1.448), respectively, in men with an ASFDDS ≥ 2. In women, a 34% increase (OR = l.34, 95%CI: 116-l.54) likelihood for better PCS was observed for an ASFDDS ≥ 2, but no association was observed for MCS. Increasing each specific animal source's food intake was associated with better PCS after adjusting for all covariates. However, for MCS, positive associations were only observed in seafood consumption among men and eggs among women. Restricted cubic splines showed a substantial dose-response association between intake frequency of animal-source foods and PCS, both in men and women. The study suggests that a diverse intake of animal-sourced foods can potentially improve the HRQoL of Chinese adults.

Generalisability and potential deaths averted from intensive blood pressure treatment among the elderly population in the US and China: A nationally representative cross-sectional study.

Background: The Systolic Blood Pressure Intervention Trial (SPRINT) from the US and the Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) trial from China have consistently demonstrated clinical benefits from intensive blood pressure (BP) treatment among elderly adults with hypertension. However, we have little data on the generalisability and potential implications of a scale-up of intensive BP treatment to all eligible elderly in the US and China. Methods: We used two nationally representative data sets from China (Health and Retirement Longitudinal Study (CHALRS), 2011-2012) and the US (National Health and Nutrition Examination Survey (NHANES), 2007-2012) and linked them with CHARLS follow-up data (2013) and the National Death Index (1999-2015), respectively. We estimated the percentage, number, and characteristics of elderly (≥60 years old) meeting the STEP and SPRINT eligibility criteria, and deaths that would be prevented or postponed with the implementation of intensive BP treatment. Results: Among the Chinese adults aged 60 years and over, 38.89% (95% confidence interval (CI) = 36.97-40.84) or 85.39 (95% CI = 81.14-89.64) million subjects met the STEP criteria, and 40.90 million (47.90%) adults were not taking antihypertensive medications. In the US, 23.77% (95% CI = 22.32%-25.28) or 12.46 (95% CI = 11.68-13.24) million elderly were eligible for the SPRINT, and 5.78 million (46.36%) were untreated. Overall, 0.07 (95% CI = 0.06-0.08) million deaths in the US and 0.31 (95% CI = 0.25-0.39) in China would be averted annually if intensive BP treatment was implemented, while 120 000 and 680 000 of hypotension cases would be identified yearly inthe US and China, respectively. Conclusions: A substantial percentage of Chinese and the US elderly meet the eligibility criteria for STEP and SPRINT. If intensive BP treatment was adopted, 70 000 and 310 000 deaths would be prevented or postponed yearly in the US and China, respectively.

Two-Dimensional Covalent Framework Derived Nonprecious Transition Metal Single-Atomic-Site Electrocatalyst toward High-Efficiency Oxygen Reduction.

Designing an active, stable, and nonprecious metal catalyst substitute for Pt in the oxygen reduction reaction (ORR) is highly demanded for energy-efficient and cost-effective prototype devices. Single-atomic-site catalysts (SASCs) have been widely concerning because of their maximum atomic utilization and precise structural regulation. Despite being challenging, the controllable synthesis of SASCs is crucial for optimizing ORR activity. Here, we demonstrate an ultrathin organometallic framework template-assisted pyrolysis strategy to synthesize SASCs with a unique two-dimensional (2D) architecture. Electrochemical measurements revealed that Fe-SASCs displayed an excellent ORR activity in an alkaline media, having a half-wave potential and a diffusion-limited current density comparable to those of commercial Pt/C. Remarkably, the durability and methanol tolerance of Fe-SASCs were even superior to those of Pt/C. Furthermore, Fe-SASCs displayed a maximum power density of 142 mW cm-2 with a current density of 235 mA cm-2 as a cathode catalyst in a zinc-air battery, showing its great potential for practical applications.

Longer time in blood pressure target range improves cardiovascular outcomes among patients with Type 2 diabetes: A secondary analysis of a randomized clinical trial.

AIMS: To examine the prognostic value of time in target range (TIR) with adverse outcomes and validate it with common blood pressure (BP) metrics among patients with Type 2 diabetes mellitus. METHODS: We performed a post hoc analysis of the ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial. TIR for each subject was calculated using linear interpolation and an SBP target range of 110 to 130 mmHg. Cox models were used to assess the association of TIR and other BP metrics with the rate of clinical outcomes. RESULTS: A higher TIR (61.9-100.0 %) was associated with a 46 % reduction in major adverse cardiovascular events (MACE) (hazard ratio [HR]:0.54; 95 % CI: 0.43, 0.67) compared with TIR 0-22.9 %. Results were similar for stroke (0.19; 0.10, 0.36), myocardial infarction (0.67; 0.51, 0.89), heart failure (0.47; 0.33, 0.66), cardiovascular death (0.63; 0.42, 0.93) and all-cause mortality (0.70; 0.54, 0.91). Further analyses suggested a curvilinear association of TIR with MACE, and this association was independent with baseline, final SBP, mean SBP, or visit-to-visit SBP variability. CONCLUSIONS: Longer TIR is associated with lower cardiovascular risk and may add value as an outcome measure for hypertension control studies among patients with diabetes.

Association of maternity formula supplementation during pregnancy with small for gestational age birth in Chinese newborns.

OBJECTIVES: This study aimed to explore the association between maternity formula supplementation and small for gestational age (SGA) status in Chinese newborns. METHODS: Data were from a population-based cross-sectional survey conducted in Shaanxi, Northwest China between August and December 2013. A total of 27 780 women pregnant with singletons and 356 with twins were included in this survey. Information on use of maternity formulas fortified with vitamins, folic acid, pantothenic acid, calcium, iron, zinc, and docosahexaenoic acid (DHA) was collected. SGA was defined as birthweight <10th percentile of fetal growth. Generalized linear models and estimating equation models were used to estimate crude odds ratios (ORs) or adjusted ORs with 95% confidence intervals (CIs) for SGA. RESULTS: The rate of maternity formula supplementation during the entire pregnancy was 13.0% in the overall population. There was no significant association between maternal formula supplementation during pregnancy and the risk of total SGA birth (OR: 1.00; 95% CI, 0.90-1.11; P = 0.950). However, maternity formula supplementation during pregnancy was related to a lower risk of SGA for twins (OR: 0.49; 95% CI, 0.31-0.80; P = 0.004), twin A (OR: 0.50; 95% CI, 0.25-0.98; P = 0.045), and twin B (OR: 0.48; 95% CI, 0.25-0.95; P = 0.034). Furthermore, maternity formula supplementation during the first trimester was inversely associated with the risk of SGA birth of twins (OR: 0.32; 95% CI, 0.15-0.65; P = 0.002). CONCLUSIONS: No significant association was observed between maternity formula supplementation and total SGA birth. However, women supplemented with maternal formula during pregnancy, especially during the first trimester, may have a reduced risk of SGA birth of twins.

Staple Food Preference and Obesity Phenotypes: The Regional Ethnic Cohort Study in Northwest China.

Staple food preference vary in populations, but evidence of its associations with obesity phenotypes are limited. Using baseline data (n = 105,840) of the Regional Ethnic Cohort Study in Northwest China, staple food preference was defined according to the intake frequency of rice and wheat. Overall and specifically abdominal fat accumulation were determined by excessive body fat percentage and waist circumference. Logistic regression and equal frequency substitution methods were used to evaluate the associations. We observed rice preference (consuming rice more frequently than wheat; 7.84% for men and 8.28% for women) was associated with a lower risk of excessive body fat (OR, 0.743; 95%CI, 0.669-0.826) and central obesity (OR, 0.886; 95%CI, 0.807-0.971) in men; and with lower risk of central obesity (OR, 0.898; 95%CI, 0.836-0.964) in women, compared with their wheat preference counterparties. Furthermore, similar but stronger inverse associations were observed in participants with normal body mass index. Wheat-to-rice (5 times/week) reallocations were associated with a 36.5% lower risk of normal-weight obesity in men and a 20.5% lower risk of normal-weight central obesity in women. Our data suggest that, compared with wheat, rice preference could be associated with lower odds ratios of certain obesity phenotypes in the Northwest Chinese population.

A Two-Dimensional van der Waals Heterostructure with Isolated Electron-Deficient Cobalt Sites toward High-Efficiency CO2 Electroreduction.

Electrochemical CO2 conversion is a promising way for sustainable chemical fuel production, yet the conversion efficiency is strongly limited by the sluggish kinetics and complex reaction pathways. Here we report the ultrathin conjugated metalloporphyrin covalent organic framework epitaxially grown on graphene as a two-dimensional van der Waals heterostructure to catalyze CO2 reduction. Operando X-ray absorption and density functional theory calculations reveal the strong interlayer coupling leads to electron-deficient metal centers and speeds up electrocatalysis. The Co(III)-N4 centers exhibit a CO Faradaic efficiency of 97% at a partial current density of 8.2 mA cm-2 in an H-cell, along with a stable running over 30 h. The selectivity of CO approached 99% with a partial current density of 191 mA cm-2 in a liquid flow cell, and the turnover frequency achieved 50 400 h-1 at -1.15 V vs RHE, outperforming most reported organometallic frameworks. This work highlights the key role of strong electronic coupling between van der Waals layers for accelerating the dynamics of CO2 conversion.

Clinical benefit of systolic blood pressure within the target range among patients with or without diabetes mellitus: a propensity score-matched analysis of two randomized clinical trials.

BACKGROUND: Recent guidelines recommended a systolic blood pressure (SBP) target of < 130 mmHg for patients with or without diabetes but without providing a lower bound. Our study aimed to explore whether additional clinical benefits remain at achieved blood pressure (BP) levels below the recommended target. METHODS: We performed a secondary analysis of the Systolic Blood Pressure Intervention Trial (SPRINT) among the non-diabetic population and the Action to Control Cardiovascular Risk in Diabetes BP (ACCORD-BP) trial among diabetic subjects. We used the propensity score method to match patients from the intensive BP group to those from the standard group in each trial. Individuals with different achieved BP levels from the intensive BP group were used as "reference." For each stratum, the trial-specific primary outcome (i.e., composite outcome of myocardial infarction (MI), acute coronary syndrome not resulting in MI, stroke, acute decompensated heart failure (HF), or cardiovascular death for SPRINT; non-fatal MI, non-fatal stroke, or cardiovascular death for ACCORD-BP) was compared by Cox regression. RESULTS: A non-linear association was observed between the mean achieved BP and incidence of composite cardiovascular events, regardless of treatment allocation. The significant treatment benefit for primary outcome remained at SBP 110-120 mmHg (hazard ratio, 0.59 [95% CI, 0.46, 0.76] for SPRINT; 0.67 [0.52, 0.88] for ACCORD-BP) and SBP 120-130 mmHg for SPRINT (0.47 [0.34, 0.63]) but not for ACCORD-BP (0.93 [0.70, 1.23]). The results were similar for the secondary outcomes including all-cause mortality, cardiovascular mortality, MI, stroke, and HF. Intensive BP treatment benefits existed among patients maintaining a diastolic BP of 60-70 mmHg but were less distinct. CONCLUSIONS: The treatment benefit persists at as low as SBP 110-120 mmHg irrespective of diabetes status. Achieved very low BP levels appeared to increase cardiovascular events and all-cause mortality.

Structure-Function Correlation and Dynamic Restructuring of Cu for Highly Efficient Electrochemical CO2 Conversion.

The increasing global demand for sustainable energy sources and emerging environmental issues have pushed the development of energy conversion and storage technologies to the forefront of chemical research. Electrochemical carbon dioxide (CO2 ) conversion provides an attractive approach to synthesizing fuels and chemical feedstocks using renewable energy. On the path to deploying this technology, basic and applied scientific hurdles remain. Copper, as the only metal catalyst that is capable to produce C2+ fuels from CO2 reduction (CO2 R), still faces challenges in the improvement of electrosynthesis pathways for highly selective fuel production. In this regard, mechanistically understanding CO2 R on Cu-based electrocatalysts, particularly identifying the structure-function correlation, is crucial. Here, a broad view of the variable structural parameters and their complex interplay in CO2 R catalysis on Cu was given, with the purpose of providing deep insights and guiding the future rational design of CO2 R electrocatalysts. First, this Review described the progress and recent advances in the development of well-defined nanostructured catalysts and the mechanistic understanding on the influences from a particular structure of a catalyst, such as facet, defects, morphology, oxidation state, composition, and interface. Next, the in-situ dynamic restructuring of Cu was presented. The importance of operando characterization methods to understand the catalyst structure-sensitivity was also discussed. Finally, some perspectives on the future outlook for electrochemical CO2 R were offered.

Impact of the 2020 China Diabetes Society Guideline on the Prevalence of Diabetes Mellitus and Eligibility for Antidiabetic Treatment in China.

PURPOSE: This study aimed to estimate the impact of the 2020 China Diabetes Society's (CDS) guideline on the prevalence of diabetes mellitus and eligibility for antidiabetic treatment in China. MATERIAL AND METHODS: Baseline data from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2012) were used to estimate the prevalence of diabetes mellitus and compare the recommendations for antidiabetic medication and intensification of therapy between the 2017 and 2020 CDS guidelines. RESULTS: According to the 2017 CDS guideline, the prevalence of diabetes mellitus was 12.56% among Chinese adults who were ≥45 years of age. However, according to the 2020 CDS guideline, 0.65% (0.35%, 1.20%), or 3.54 (2.50, 4.57) million Chinese adults who were ≥45 years would additionally be diagnosed with diabetes mellitus. Among Chinese adults not taking antidiabetic medications, 1.06% (0.87%, 1.28%), or 5.37 (4.36, 6.38) million Chinese adults with diabetes mellitus were recommended to start antidiabetic medication according to the 2017 CDS guideline, while 1.27% (1.01%, 1.58%), or 6.44 (5.29, 7.60) million Chinese adults with diabetes would be recommended to initiate antidiabetic medication according to the 2020 CDS guideline. Among Chinese adults taking antidiabetic medication, 51.59% (44.19%, 58.93%), or 18.35 (15.58, 21.12) million Chinese adults with diabetes received antidiabetic treatment but had a hemoglobin A1c (HbA1c) level higher than that mentioned in the 2017 and 2020 CDS guidelines. CONCLUSION: The addition of HbA1c in the 2020 CDS guideline will result in a modest increase in the number of Chinese adults who are diagnosed with diabetes and diabetes patients recommended for antidiabetic medication; however, the 2020 CDS guideline does not affect the number of diabetes patients eligible for intensification of treatment.

Association of Short and Long Interpregnancy Intervals with Adverse Birth Outcomes: Evidence from a Cross-Sectional Study in Northwest China.

PURPOSE: To analyze the effects of a short interpregnancy interval (IPI) (<6 months) and a long IPI (>120 months) on neonatal adverse birth outcomes including low birth weight (LBW), small for gestational age (SGA), preterm birth (PTB), and birth defects in Shaanxi Province. PATIENTS AND METHODS: A stratified multistage random sampling method was used to recruit participants who gave birth between 2010 and 2013 in Shaanxi province. A self-designed questionnaire was used to collect the information of the participants. With the confounding factors controlled, the generalized linear model (GLM) was used to investigate the association between IPI and neonatal birth outcomes. The restricted cubic spline (RCS) function was used to evaluate the dose-response relationship between IPI and birth outcomes. RESULTS: A total of 13,231 women were included. The prevalence of LBW, SGA, PTB, and birth defects was 3.24%, 12.96%, 2.93%, and 2.12%, respectively. GLM showed that a short IPI (<6 months) was associated with a higher risk of SGA (RR=1.25, 95% CI: 1.04-1.52) and birth defects (RR=2.55, 95% CI: 1.45-4.47), and a long IPI (≥120 months) was associated with a higher risk of LBW (RR=1.54, 95% CI: 1.01-2.34) and PTB (RR=1.73, 95% CI: 1.08-2.76) than an IPI of 18-23 months. The RCS showed that LBW, SGA, and PTB demonstrated a j-shaped relationship with IPI (P for overall association < 0.001 for these three birth outcomes), and birth defects (P for overall association <0.001) had an inversely non-linear relationship with IPI. CONCLUSION: Both short and long IPIs are associated with an increased risk of adverse birth outcomes.

Association between maternal iron supplementation and newborn birth weight: a quantile regression analysis.

OBJECTIVE: Our study aimed to explore the association between maternal iron supplementation and newborn birth weight (BW) in Shaanxi Province using quantile regression (QR). METHOD: The data used in this study were derived from a large cross-sectional survey of a population in Shaanxi Province, Northwest China. A total of 28,209 women and their infants were selected using a stratified multistage random sampling method. The effect of iron supplementation on the newborn BW was assessed by a multiple linear regression model and QR. RESULTS: A total of 5.15% of the women took iron supplements during pregnancy. Multiple linear regression showed that the iron supplementation during pregnancy had positive effects on the BW, with an average increase of 43.07 g (ß = 43.07, t = 3.55, and p < 0.001). The QR showed that the iron supplementation during pregnancy was associated with an increased newborn BW from very low to higher percentiles (quantiles: 0 ~ 0.40), with the ß ranging from 136.51 to 43.86. As the percentiles of the BW increased, the neonatal BW gain gradually declined in the iron supplementation group compared with the group that did not receive iron supplementation (quantiles: 0 ~ 0.40, with the ß ranging from 136.51 to 43.86). Iron supplementation was more effective among women who suffered from anemia during pregnancy (ß = 45.84, t = 2.05, and p = 0.04; quantiles: 0 ~ 0.15, 0.30, 0.80, with ß ranging from 150.00 to 39.29) than it was in any other group (ß = 38.18, t = 2.62, and p = 0.009; quantiles: 0 ~ 0.15, with ß ranging from 133.33 to 28.32). CONCLUSIONS: Iron supplementation during pregnancy is associated with an increased newborn BW, and the effect was more obvious in the newborns with the lower BW and newborns whose mothers suffered from anemia during pregnancy.

Graphdiyne/Graphene Heterostructure: A Universal 2D Scaffold Anchoring Monodispersed Transition-Metal Phthalocyanines for Selective and Durable CO2 Electroreduction.

Electrochemical CO2 reduction (CO2R) is a sustainable way of producing carbon-neutral fuels, yet the efficiency is limited by its sluggish kinetics and complex reaction pathways. Developing active, selective, and stable CO2R electrocatalysts is challenging and entails intelligent material structure design and tailoring. Here we show a graphdiyne/graphene (GDY/G) heterostructure as a 2D conductive scaffold to anchor monodispersed cobalt phthalocyanine (CoPc) and reduce CO2 with an appreciable activity, selectivity, and durability. Advanced characterizations, e.g., synchrotron-based X-ray absorption spectroscopy (XAS), and density functional theory (DFT) calculation disclose that the strong electronic coupling between GDY and CoPc, together with the high surface area, abundant reactive centers, and electron conductivity provided by graphene, synergistically contribute to this distinguished electrocatalytic performance. Electrochemical measurements revealed a high FECO of 96% at a partial current density of 12 mA cm-2 in a H-cell and an FECO of 97% at 100 mA cm-2 in a liquid flow cell, along with a durability over 24 h. The per-site turnover frequency of CoPc reaches 37 s-1 at -1.0 V vs RHE, outperforming most of the reported phthalocyanine- and porphyrin-based electrocatalysts. The usage of the GDY/G heterostructure as a scaffold can be further extended to other organometallic complexes beyond CoPc. Our findings lend credence to the prospect of the GDY/G hybrid contributing to the design of single-molecule dispersed CO2R catalysts for sustainable energy conversion.

Enhanced Electrochemical Methanation of Carbon Dioxide at the Single-Layer Hexagonal Boron Nitride/Cu Interfacial Perimeter.

The electrochemical conversion of CO2 to valuable fuels is a plausible solution to meet the soaring need for renewable energy sources. However, the practical application of this process is limited by its poor selectivity due to scaling relations. Here we introduce the rational design of the monolayer hexagonal boron nitride/copper (h-BN/Cu) interface to circumvent scaling relations and improve the electrosynthesis of CH4. This catalyst possesses a selectivity of >60% toward CH4 with a production rate of 15 µmol·cm-2·h-1 at -1.00 V vs RHE, along with a much smaller decaying production rate than that of pristine Cu. Both experimental and theoretical calculations disclosed that h-BN/Cu interfacial perimeters provide specific chelating sites to immobilize the intermediates, which accelerates the conversion of *CO to *CHO. Our work reports a novel Cu catalyst engineering strategy and demonstrates the prospect of monolayer h-BN contributing to the design of heterostructured CO2 reduction electrocatalysts for sustainable energy conversion.

Associations between maternal calcium intake from diet and supplements during pregnancy and the risk of preterm birth in a Chinese population.

BACKGROUND/OBJECTIVES: Preterm birth is a global public health priority related to maternal nutrition. The effect of maternal calcium intake during pregnancy on preterm birth is inconclusive and data is lacking in China. We aimed to estimate the role of calcium intake from diet and supplements on preterm birth in the Chinese population. METHODS: We used data of 7195 women from a large-scale cross-sectional study in Northwest China. Dietary intake was evaluated via a validated food frequency questionnaire, and other information was collected by a structured questionnaire. Generalized estimating equation models were used to estimate the relationship between calcium intake and preterm birth. RESULTS: Inadequate dietary calcium intake was universal in our population (85.9%), and no association was found between daily dietary calcium intake and preterm birth. Maternal calcium supplementation was significantly associated with reduced risk of preterm birth (OR 0.72, 95% CI 0.60, 0.87, P = 0.001), particularly among women who commenced calcium supplementation in the second and third trimester of pregnancy with longer duration (OR 0.62, 95% CI 0.42, 0.91, P = 0.015). Higher daily calcium intake from supplements was linked with lower preterm birth risk (every 100 mg increase: OR 0.87, 95% CI 0.79, 0.96, P = 0.004). There is a negative association between daily total calcium intake and preterm birth among calcium supplement users (every 100 mg increase: OR 0.91, 95% CI 0.84, 0.97, P = 0.007). CONCLUSIONS: In conclusion, appropriate calcium supplementation during pregnancy could be beneficial in the prevention of preterm birth, and it might be suitable for implementing in low calcium intake areas of China.

Maternal exposure to low-to-medium altitude and birth outcomes: evidence from a population-based study in Chinese newborns.

Despite high altitude was implicated in adverse birth outcomes, there remained a paucity of evidence on low-to-medium altitude effect. This study aimed to explore the association of low-to-medium altitude with birth outcomes. A population-based cross-sectional survey was performed using a stratified multistage random sampling method among women with their infants born during 2010-2013 in Northwestern China. Altitude was determined in meters based on the village or community of the mother's living areas. Birth outcomes involved birth weight, gestational age, and small for gestational age (SGA). Generalized linear models were fitted to investigate the association of altitude with birth outcomes. Moreover, the dose-response relationship between altitude and birth outcomes was evaluated with a restricted cubic spline function. A total of 27 801 women with their infants were included. After adjusting for potential confounders, every 100-m increase in the altitude was associated with reduced birth weight by 6.4 (95% CI -8.1, -4.6) g, the slight increase of gestational age by 0.015 (95% CI 0.010, 0.020) week, and an increased risk of SGA birth (odds ratio 1.03, 95% CI 1.02, 1.04). Moreover, there was an inversely linear relationship between altitude and birth weight (P for overall < 0.001 and P for nonlinear = 0.312), and a positive linear relationship between altitude and SGA (P for overall < 0.001 and P for nonlinear = 0.194). However, a nonlinear relationship was observed between altitude and gestational age (P for overall < 0.001 and P for nonlinear = 0.010). The present results suggest that low-to-medium altitude is possibly associated with adverse birth outcomes.

Job satisfaction among primary care physicians in western China.

BACKGROUND: There has been great shortage of primary care physicians (PCPs) in China, especially in western areas. Job satisfaction plays a great role in retaining people. The aim of this study is to investigate the job satisfaction of PCPs and associated factors in 11 provinces of western China, thus providing necessary reference values for stabilizing the primary care workforce and improving the quality of primary care services. METHOD: A sample of 2103 PCPs working in western China were surveyed using a stratified, multistage and random sampling method in 2011. The characteristics of participants were recorded by a structured questionnaire. A multilevel model (MLM) and quantile regression (QR) were applied to assess the association between job satisfaction and possible risk factors. RESULTS: Of the 2103 doctors surveyed, the overall satisfaction score was 3.26 ± 0.68 (from 1 to 5). MLM indicated that age group, income satisfaction, unit policy approval, personal planning, career attitude, work value and patient recognition were positively correlated with job satisfaction, while turnover intention was negatively correlated with job satisfaction. QR were not completely consistent with MLM and further explored the differences in different job satisfaction score percentiles on each domains. CONCLUSION: This study showed that the job satisfaction of PCPs in western China was not high. The MLM and QR discussed were not entirely consistent, the latter one provided more information and robust results. Measures should be taken in streamlining administration and institute decentralization, creating more opportunities for additional training, raising PCPs' income, improving the social status of doctors and improving the relationship between doctors and patients.