Graphic carbon nitride prepared by the thermal decomposition of urea was used a catalyst support for the in situ immobilization of Ru nanoparticles (NPs) (Ru/g-C sub(3)N sub(4)). The catalytic ...property of Ru/g-C sub(3)N sub(4) was investigated in the hydrolysis of ammonia borane (AB) in an aqueous solution under mild conditions. Results show that the in situ generated Ru NPs are well dispersed on the surface of g-C sub(3)N sub(4) with a mean particle size of 2.8 nm. The catalytic performance for AB hydrolysis indicates that 3.28 wt% Ru/g-C sub(3)N sub(4) exhibits excellent catalytic activity with a high turnover frequency number of 313.0 mol H sub(2) (mol Ru.min) super(-1) at room temperature. This strategy may provide an eco-friendly catalytic system for developing a sustainable catalytic route to hydrogen production.
It has been reported that folic acid supplementation before and/or during pregnancy could reduce the risk of congenital heart defects (CHDs). However, the results from limited epidemiologic studies ...have been inconclusive. We investigated the associations between maternal folic acid supplementation, dietary folate intake, and the risk of CHDs.
A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. After exclusion of stillbirths and multiple births, a total of 94 births were identified with congenital heart defects, and 9,993 births without any birth defects. Unconditional logistic regression was used to estimate the associations.
Compared to non-users, folic acid supplement users before pregnancy had a reduced risk of overall CHDs (OR: 0.42, 95% CI: 0.21-0.86, Ptrend = 0.025) after adjusted for potential confounders. A protective effect was observed for certain subtypes of CHDs (OR: 0.37, 95% CI: 0.16-0.85 for malformation of great arteries; 0.26, 0.10-0.68 for malformation of cardiac septa; 0.34, 0.13-0.93 for Atrial septal defect). A similar protective effect was also seen for multiple CHDs (OR: 0.49, 95% CI: 0.26-0.93, Ptrend = 0.004). Compared with the middle quartiles of dietary folate intake, lower dietary folate intake (<149.88 μg/day) during pregnancy were associated with increased risk of overall CHDs (OR: 1.63, 95% CI: 1.01-2.62) and patent ductus arteriosus (OR: 1.85, 95% CI: 1.03-3.32). Women who were non-user folic acid supplement and lower dietary folate intake have almost 2-fold increased CHDs risk in their offspring.
Our study suggested that folic acid supplementation before pregnancy was associated with a reduced risk of CHDs, lower dietary folate intake during pregnancy was associated with increased risk. The observed associations varied by CHD subtypes. A synergistic effect of dietary folate intake and folic acid supplementation was also observed.
To evaluate the independent and joint effects of maternal pre-pregnancy BMI and gestational weight gain (GWG) on the risk of preeclampsia and its subtypes.
A birth cohort study was conducted from ...2010 to 2012 in Lanzhou, China. Three hundred fourty seven pregnant women with preeclampsia and 9516 normotensive women at Gansu Provincial Maternity and Child Care Hospital were included in the present study. Unconditional logistic regression models were used to evaluate the associations between pre-pregnancy BMI, GWG, and risk of preeclampsia and its subtypes.
Compared to women with normal pre-pregnancy BMI, those who were overweight/obese had an increased risk of preeclampsia (OR = 1.81; 95%CI: 1.37-2.39). Women with excessive GWG had an increased risk of preeclampsia (OR = 2.28; 95%CI: 1.70-3.05) compared to women with adequate GWG. The observed increased risk was similar for mild-, severe- and late-onset preeclampsia. No association was found for early-onset preeclampsia. Overweight/obese women with excessive GWG had the highest risk of developing preeclampsia compared to normal weight women with no excessive weight gain (OR = 3.78; 95%CI: 2.65-5.41).
Our results suggested that pre-pregnancy BMI and GWG are independent risk factors for preeclampsia and that the risk might vary by preeclampsia subtypes. Our study also proposed a potential synergistic effect of pre-pregnancy BMI and GWG that warrants further investigation.
In this paper, the evolution of the γ′ and η phases of new Ni–Co-based superalloy with different Nb contents was investigated using a combination of thermodynamic calculations and high-throughput ...selective laser melting (SLM). Thermodynamic calculations show that the increase of Nb content lowered the solubility temperature of the γ′ phase and caused the precipitation of the η phase. The alloys with the Nb gradient content prepared by SLM during aging at 800 °C for 100h indicated that the maximum volume fraction and size of the γ′ phase reach the maximum at 3.0–3.5% Nb. The elongated η phases enrichment in Ni, Ti, and Nb atoms precipitate for the Nb content higher than 2.2% Nb and prefer to grow longitudinally at the expense of the γ′ precipitates. Combining the influence of the Al/(Nb + Ta + Ti) ratio on the η precipitates, the addition of Nb content in the Ni–Co-based superalloys is less than 2.2%, which increases the high-temperature yield strength and tensile strength.
Studies investigating the relationship between maternal passive smoking and the risk of preterm birth have reached inconsistent conclusions. A birth cohort study that included 10,095 nonsmoking women ...who delivered a singleton live birth was carried out in Lanzhou, China, between 2010 and 2012. Exposure to passive smoking during pregnancy was associated with an increased risk of very preterm birth (<32 completed weeks of gestation; odds ratio = 1.98, 95% confidence interval: 1.41, 2.76) but not moderate preterm birth (32-36 completed weeks of gestation; odds ratio = 0.98, 95% confidence interval: 0.81, 1.19). Risk of very preterm birth increased with the duration of exposure (P for trend = 0.0014). There was no variability in exposures by trimester. The associations were consistent for both medically indicated and spontaneous preterm births. Overall, our findings support a positive association between passive smoking and the risk of very preterm birth.
Congenital heart defects are the most prevalent type of birth defects. The association of air pollution with congenital heart defects is not well understood. We investigated a cohort of 8969 ...singleton live births in Lanzhou, China during 2010-2012. Using inverse distance weighting, maternal exposures to particulate matter with diameters ≤10 m (PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2) were estimated as a combination of monitoring station levels for time spent at home and in a work location. We used logistic regression to estimate the associations, adjusting for maternal age, education, income, BMI, disease, folic acid intake and therapeutic drug use, and smoking; season of conception, fuel used for cooking and temperature. We found significant positive associations of Patent Ductus Arteriosus (PDA) with PM10 during the 1st trimester, 2nd trimester and the entire pregnancy (OR 1st trimester = 3.96, 95% confidence interval (CI): 1.36, 11.53; OR 2nd trimester = 3.59, 95% CI: 1.57, 8.22; OR entire pregnancy = 2.09, 95% CI: 1.21, 3.62, per interquartile range (IQR) increment for PM10 (IQR = 71.2, 61.6, and 27.4 g m−3, respectively)), and associations with NO2 during 2nd trimester and the entire pregnancy (OR 2nd trimester = 1.92, 95% CI: 1.11, 3.34; OR entire pregnancy = 2.32, 95% Cl: 1.14, 4.71, per IQR increment for NO2 (IQR = 13.4 and 10.9 g m−3, respectively)). The associations for congenital malformations of the great arteries and pooled cases showed consistent patterns. We also found positive associations for congenital malformations of cardiac septa with PM10 exposures in the 2nd trimester and the entire pregnancy, and SO2 exposures in the entire pregnancy. Results indicate a health burden from maternal exposures to air pollution, with increased risk of congenital heart defects.
Studies investigating the relationship between maternal tea drinking and risk of preterm birth have reached inconsistent results.
The present study analyzed data from a birth cohort study including ...10,179 women who delivered a singleton live birth were conducted in Lanzhou, China between 2010 and 2012.
Drinking tea (OR = 1.36, 95 % CI: 1.09-1.69), and specifically green (OR = 1.42, 95 % CI: 1.08-1.85) or scented tea (OR = 1.61, 95 % CI: 1.04-2.50), was associated with an increased risk of preterm birth. Drinking tea was associated with both moderate preterm (OR = 1.41, 95 % CI: 1.12-1.79) and spontaneous preterm birth (OR = 1.41, 95 % CI: 1.09-1.83). Risk of preterm birth increased with decreasing age of starting tea drinking (<20 years, OR = 1.60, 95 % CI: 1.17-2.20) and increasing duration (p for trend < 0.01). The relationship between tea drinking and preterm birth is modified by both maternal age (p < 0.05) and gestational weight gain (p < 0.05).
Despite conflicting findings in the previous literature, we saw a significant association with maternal tea drinking and risk of preterm birth in our cohort. More studies are needed both to confirm this finding and to elucidate the mechanism behind this association.
Objectives
To investigate the independent and collective effects of maternal folic acid supplementation or dietary folate intake on the risk of low birth weight (LBW), and to further comprehensively ...examine the joint associations of folic acid supplementation and dietary folate intake with LBW by various clinical subtypes.
Design
Participants were recruited from Gansu Provincial Maternity and Child Care Hospital. A standardized and structured questionnaire was distributed to collect demographic factors, reproductive and medical history, occupational and residential history, physical activity, and diet. Data on pregnancy-related complications and birth outcomes were extracted from medical records. Unconditional logistic regression models were used to estimate the odds ratio (
OR
) and 95% confidence interval (95%
CI
) for single and joint associations of folic acid supplementation and dietary folate intake with LBW.
Setting
A birth cohort data analysis using the 2010–2012 Gansu Provincial Maternity and Child Care Hospital in Lanzhou, China.
Participants
In total, 9,231 pregnant women and their children were enrolled in the study.
Results
Compared with non-users, folic acid supplementation was associated with a reduced risk of LBW (
OR
: 0.80, 95%
CI
: 0.66–0.97), and the reduced risk was mainly seen for term-LBW (
OR
: 0.59, 95%
CI
: 0.41–0.85), and multiparous-LBW (
OR
: 0.72, 95%
CI
: 0.54–0.94). There were no significant associations between dietary folate intake and LBW, and there was no interaction between folic acid supplement and dietary folate intake on LBW.
Conclusions
Our study results indicated that folic acid supplementation was associated with a reduced risk of LBW, and there was no interaction between folic acid supplements and dietary folate intake on LBW.
This article describes the characteristics of natural dusts, industrial dusts, and artificial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and ...calcite are the main phases of natural dusts and industrial dusts with high SiO
2
and CaO and low K
2
O and Na
2
O in the chemical composition. The dissolution and electrochemical action of dusts in glutamic acid liquor at the simulated human body temperature (37 °C) in 32 h was investigated. The potential harm that the dust could lead to in body glutamic acid acidic environment, namely biological activity, is of great importance for revealing the human toxicological mechanism. The changes of pH values and electric conductivity of suspension of those dusts were similar, increased slowly in the first 8 h, and then the pH values increased rapidly. The total amount of dissolved ions of K, Ca, Na, and Mg was 35.4 to 429 mg/kg, particularly Ca was maximal of 20 to 334 mg/kg. The total amount of dissolved ions of Fe, Zn, Mn, Pb, and Ba was 0.18 to 5.59 mg/kg and in Al and Si was 3.0 to 21.7 mg/kg. The relative solubility order of dusts in glutamic acid is wollastonite > serpentine > sepiolite, the cement plant industrial dusts > natural dusts > power plant industrial dusts. The wollastonite and cement plant industrial dusts have the highest solubility, which also have high content of CaO; this shows that there are a poorer corrosion-resisting ability and lower bio-resistibility. Sepiolite and power plant industrial dusts have lowest solubility, which also have high content of SiO
2
; this shows that there are a higher corrosion-resisting ability and stronger bio-resistibility.
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