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To investigate the association of folic acid (FA) supplementation with birth weight, the risk of small for gestational age (SGA) and low birth weight (LBW) in singleton and twin pregnancy.
A population-based cross-sectional survey.
Twenty counties and ten districts in Shaanxi Province of northwestern China, 2013.
28 174 pregnant women with their infants, covering 27 818 single live births and 356 twin live births.
The prevalence of FA supplementation in singletons and twins was 63·9 and 66·3 %. The mean birth weight was 3267 (sd 459·1) g, 2525 (sd 534·0) g and 2494 (sd 539·5) g; the prevalence of SGA was 14·3, 51·4 and 53·4 %; the prevalence of LBW was 3·4, 42·4 and 46·6 % among singleton, twin A and twin B, respectively. Compared with non-users, women with FA supplementation were (β 17·3, 95 % CI 6·1, 28·4; β 166·3, 95 % CI 69·1, 263·5) associated with increased birth weight, lower risk of SGA (OR 0·85, 95 % CI 0·80, 0·92; OR 0·45, 95 % CI 0·30, 0·68) and LBW (OR 0·82, 95 % CI 0·71, 0·95; OR 0·50, 95 % CI 0·33, 0·75) in singletons and twins, and more prominent effects in twins. Moreover, there were significant interactions between FA supplementation and plurality on birth weight, SGA and LBW.
The present study suggests the association of periconceptional 0·4 mg/d FA supplementation with increased birth weight and reduced risk of SGA and LBW in both singletons and twins, and this association may be more prominent in twins.
Corporate social responsibility (CSR) disclosure is becoming increasingly important for modern corporations. Focusing on voluntary CSR disclosure and drawing on upper echelons theory, we propose that voluntary CSR disclosure is the manifestation of managerial preferences (e.g., managers’ professional ethical values and standards). Specifically, we argue that top executives with an academic background tend to have higher professional and ethical standards than their non-academic counterparts. These standards lead them to act with self-restraint and to perceive CSR disclosure as an opportunity rather than a threat. Compared with non-academic executives, therefore, top executives with an academic background provide stakeholders with more CSR information. Based on a sample of publicly listed firms in China, we find a significant difference in voluntary CSR disclosure between firms led by academic executives and firms without academic top executives. This difference is smaller for firms that are state-owned, firms that are audited by large audit firms, and firms with greater analyst coverage. We contribute to the literature on CSR voluntary disclosure by providing an in-depth analysis of the effects of top management teams’ academic backgrounds.
Previous studies have shown conflicting findings regarding the relationship between maternal vitamin D deficiency (VDD) and fetal growth restriction (FGR). We hypothesised that parathyroid hormone (PTH) may be an underlying factor relevant to this potential association. In a prospective birth cohort study, descriptive statistics were evaluated for the demographic characteristics of 3407 pregnancies in the second trimester from three antenatal clinics in Hefei, China. The association of the combined status of vitamin D and PTH with birth weight and the risk of small for gestational age (SGA) was assessed by a multivariate linear and binary logistic regression. We found that declined status of 25-hydroxyvitamin D is associated with lower birth weight (for moderate VDD: adjusted β = −49·4 g, 95 % CI −91·1, −7·8, P < 0·05; for severe VDD: adjusted β = −79·8 g, 95 % CI −127·2, −32·5, P < 0·01), as well as ascended levels of PTH (for elevated PTH: adjusted β = −44·5 g, 95 % CI −82·6, −6·4, P < 0·05). Compared with the non-VDD group with non-elevated PTH, pregnancies with severe VDD and elevated PTH had the lowest neonatal birth weight (adjusted β = −124·7 g, 95 % CI −194·6, −54·8, P < 0·001) and the highest risk of SGA (adjusted risk ratio (RR) = 3·36, 95 % CI 1·41, 8·03, P < 0·01). Notably, the highest risk of less Ca supplementation was founded in severe VDD group with elevated PTH (adjusted RR = 4·67, 95 % CI 2·78, 7·85, P < 0·001). In conclusion, elevated PTH induced by less Ca supplementation would further aggravate the risk of FGR in pregnancies with severe VDD through impaired maternal Ca metabolism homoeostasis.
We aimed to comprehensively examine the association of breast-feeding, types and initial timing of complementary foods with adolescent cognitive development in low- and middle-income countries. We conducted a prospective cohort study of 745 adolescents aged 10–12 years who were born to women who participated in a randomised trial of prenatal micronutrient supplementation in rural Western China. An infant feeding index was constructed based on the current WHO recommendations. Full-scale intelligence quotient (FSIQ) was assessed and derived by the fourth edition of the Wechsler Intelligence Scale for Children. The duration of exclusive or any breast-feeding was not significantly associated with adolescent cognitive development. Participants who regularly consumed Fe-rich or Fe-fortified foods during 6–23 months of age had higher FSIQ than those who did not (adjusted mean differences 4·25; 95 % CI 1·99, 6·51). For cows’/goats’ milk and high protein-based food, the highest FSIQ was found in participants who initially consumed at 10–12 and 7–9 months, respectively. A strong dose–response relationship of the composite infant feeding index was also identified, with participants in the highest tertile of overall feeding quality having 3·03 (95 % CI 1·37, 4·70) points higher FSIQ than those in the lowest tertile. These findings suggest that appropriate infant feeding practices (breast-feeding plus timely introduction of appropriate complementary foods) were associated with significantly improved early adolescent cognitive development scores in rural China. In addition, improvement in Fe-rich or Fe-fortified foods complementary feeding may produce better adolescent cognitive development outcomes.
Prior data on long-term association between legume consumption and hypertension risk are sparse. We aimed to evaluate whether total legume and subtype intakes prospectively associate with hypertension incidence among 8758 participants (≥30 years) from the China Health and Nutrition Survey 2004–2011. Diet was assessed by interviews combining 3-d 24-h food recalls and household food inventory weighing at each survey round. Incident hypertension was identified by self-reports or blood pressure measurements. We applied multivariable Cox regressions to estimate hazard ratios (HR) with corresponding 95 % CI for hypertension across increasing categories of cumulatively averaged legume intakes. For 35 990 person-years (median 6·0 years apiece), we documented 944 hypertension cases. After covariate adjustment, higher total legume intakes were significantly associated with lower hypertension risks, with HR comparing extreme categories being 0·56 (95 % CI 0·43, 0·71; Ptrend < 0·001). Then we found that intakes of dried legumes (HR 0·53 (95 % CI 0·43, 0·65); Ptrend < 0·001) and fresh legumes (HR 0·67 (95 % CI 0·55, 0·81); Ptrend < 0·001) were both related to decreased hypertension hazards. However, further dried legume classification revealed that negative association with hypertension substantially held for soyabean (HR 0·51 (95 % CI 0·41, 0·62); Ptrend < 0·001) but not non-soyabean intakes. In stratified analyses, the association of interest remained similar within strata by sex, BMI, physical activity, smoking and drinking status; rather, significant heterogeneity showed across age strata (Pinteraction = 0·02). Total legume consumption among the over-65s was related to a more markedly reduced hypertension risk (HR 0·47 (95 % CI 0·30, 0·73); Ptrend < 0·001). Our findings suggest an inverse association of all kinds of legume (except non-soyabean) intakes with hypertension risks.
Firefighters are routinely exposed to various traumatic events and often experience a range of trauma-related symptoms. Although these repeated traumatic exposures rarely progress to the development of post-traumatic stress disorder, firefighters are still considered to be a vulnerable population with regard to trauma.
To investigate how the human brain responds to or compensates for the repeated experience of traumatic stress.
We included 98 healthy firefighters with repeated traumatic experiences but without any diagnosis of mental illness and 98 non-firefighter healthy individuals without any history of trauma. Functional connectivity within the fear circuitry, which consists of the dorsal anterior cingulate cortex, insula, amygdala, hippocampus and ventromedial prefrontal cortex (vmPFC), was examined using resting-state functional magnetic resonance imaging. Trauma-related symptoms were evaluated using the Impact of Event Scale – Revised.
The firefighter group had greater functional connectivity between the insula and several regions of the fear circuitry including the bilateral amygdalae, bilateral hippocampi and vmPFC as compared with healthy individuals. In the firefighter group, stronger insula–amygdala connectivity was associated with greater severity of trauma-related symptoms (β = 0.36, P = 0.005), whereas higher insula–vmPFC connectivity was related to milder symptoms in response to repeated trauma (β = −0.28, P = 0.01).
The current findings suggest an active involvement of insular functional connectivity in response to repeated traumatic stress. Functional connectivity of the insula in relation to the amygdala and vmPFC may be potential pathways that underlie the risk for and resilience to repeated traumatic stress, respectively.
Northeastern China is a region of high tick abundance, multiple tick-borne pathogens and likely human infections. The spectrum of diseases caused by tick-borne pathogens has not been objectively evaluated in this region for clinical management and for comparison with other regions globally where tick-transmitted diseases are common. Based on clinical symptoms, PCR, indirect immunofluorescent assay and (or) blood smear, we identified and described tick-borne diseases from patients with recent tick bite seen at Mudanjiang Forestry Central Hospital. From May 2010 to September 2011, 42% (75/180) of patients were diagnosed with a specific tick-borne disease, including Lyme borreliosis, tick-borne encephalitis, human granulocytic anaplasmosis, human babesiosis and spotted fever group rickettsiosis. When we compared clinical and laboratory features to identify factors that might discriminate tick-transmitted infections from those lacking that evidence, we revealed that erythema migrans and neurological manifestations were statistically significantly differently presented between those with and without documented aetiologies (P < 0.001, P = 0.003). Twelve patients (6.7%, 12/180) were co-infected with two tick-borne pathogens. We demonstrated the poor ability of clinicians to identify the specific tick-borne disease. In addition, it is necessary to develop specific laboratory assays for optimal diagnosis of tick-borne diseases.
As a key indicator of childhood malnutrition, few studies have focused on stunting in relation to various socio-economic factors in which disadvantaged groups face in China. We conducted a community-based cross-sectional study incorporating forty-two rural counties in seven western provinces of China in 2011. In total, 5196 children aged 6–23 months were included. We used Poisson regression to examine risk factors for inadequate minimum dietary diversity (MDD) and stunting status, respectively. Overall, the proportion of children not meeting MDD was 44·5 %. Children aged 6–11 months (adjusted risk ratio (ARR)=1·39; 95 % CI 1·31, 1·49), with two siblings (ARR=1·09; 95 % CI 1·02, 1·17), delivered at home (ARR=1·30; 95 % CI 1·20, 1·41), within Yi (ARR=1·15; 95 % CI 1·04, 1·28) or Uighur groups (ARR=1·52; 95 % CI 1·36, 1·71), with an illiterate caregiver (ARR=2·12; 95 % CI 1·52, 2·96), receiving lowest income (ARR=1·32; 95 % CI 1·17, 1·50), and with breast-feeding in the last day (ARR=1·55; 95 % CI 1·44, 1·66) were more likely to have inadequate MDD. Moreover, inadequate MDD was positively associated with stunting (ARR=1·15; 95 % CI 1·01, 1·31). Other determinants for stunting were age, sex, place of delivery, minority group and income. The stunting prevalence and proportion of inadequate MDD remained high in Western China; to reduce stunting rates of ethnic minorities, further efforts addressing appropriate dietary feeding practices are needed, especially within these groups.
A “RE-free” and I-phase-containing Mg–8Sn-based alloy system was developed and successfully fabricated through the equal channel angular pressing (ECAP) process. The influence of the Zn/Al mass ratio on the microstructures and mechanical properties of the as-ECAPed Mg–8Sn–(5,6,7)Zn–2(wt%)Al alloys was investigated using an optical microscope, an X-ray diffractometer, a scanning electron microscope, a transmission electron microscope, and a universal testing machine. Grain size, dynamic recrystallization behavior, and texture were found to be greatly affected by the Zn/Al mass ratio. Furthermore, the ultimate tensile strength (250 MPa) and elongation (14.5%) of the alloy with a Zn/Al mass ratio of 3 were considerably increased compared to those of the as-ECAPed alloys with Zn/Al ratios of 2.5 and 3.5 (ultimate tensile strength and elongation of 215 MPa and 13% and 184 MPa and 10%, respectively). This significant enhancement was attributed to extensive grain boundary strengthening, precipitation strengthening, and higher work hardening capacity as well as texture randomization. The strength and ductility of the as-ECAPed alloys are also discussed in terms of the I-phase and Mg2Sn formation.
Although the strong coupling of polarization to spontaneous strain in ferroelectrics would impart a flux-closure with severe disclination strains, recent studies have successfully stabilized such a domain via a nano-scaled multi-layer growth. Nonetheless, the detailed distributions of polarizations in three-dimensions (3D) and how the strains inside a flux closure affect the structures of domain walls are still less understood. Here we report a 3D polarization texture of a 4-fold flux closure domain identified in tensile strained ferroelectric PbTiO3/SrTiO3 multilayer films. Ferroelectric displacement analysis based on aberration-corrected scanning transmission electron microscopic imaging reveals highly inhomogeneous strains with strain gradient above 107/m. These giant disclination strains significantly broaden the 90° domain walls, while the flexoelectric coupling at 180° domain wall is less affected. The present observations are helpful for understanding the basics of topological dipole textures and indicate novel applications of ferroelectrics through engineering strains.
Creative conceptual design requires significant previous design knowledge. Case-based reasoning enables learning from previous design experience and has a great potential in supporting creative conceptual design by means of seeking to retrieve, reuse, and revise most appropriate cases to generate inspired solutions. However, traditional case-based reasoning based creative conceptual design models focus on design strategies research, pay little attention to defining a consistent knowledge representation model, and neglect the research to make various types of knowledge retrieval tractable. Faced with such drawbacks, the expected design knowledge cannot be retrieved properly, especially in cases where multidisciplinary knowledge is concerned or exact query terms are absent. In order to solve these issues, this paper presents a combined approach to support creative conceptual design process. First, function–behavior–structure knowledge cell is introduced as a unified consistent design knowledge representation model. Second, a hybrid similarity measure is proposed to increase the overall possibility of obtaining useful design knowledge by considering semantic understanding ability. Third, an intelligent creative conceptual design system has been developed with a case study of a novel insulin pump design to demonstrate its usage, and two experiments are conducted to evaluate the performance of the proposed approach. The results show that the proposed approach outperforms other case-based reasoning based creative conceptual design models.
The present study was conducted to evaluate the anti-parasitic activity of a pure compound from Streptomyces sp. HL-2-14 against fish parasite Ichthyophthirius multifiliis, and elucidate its chemical structure. By electron ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance spectrum (1H NMR and 13C NMR), the compound was identified as amphotericin B (AmB). The in vitro trials revealed that AmB can effectively kill the theronts and tomonts of I. multifiliis with the median lethal concentration (LC50) of 0·8 mg L−1 at 30 min for the theronts and 4·3 mg L−1 at 2 h for the tomonts, respectively. AmB at 5 mg L−1 significantly reduced I. multifiliis infectivity prevalence and intensity on grass carp (Ctenopharyngodon idella), and consequently decreased fish mortality, from 100% in control group to 30% in treated group. The 72 h acute toxicity (LC50) of AmB on grass carp was 20·6 mg L−1, but fish mortality was occurred when exposure to 13·0 mg L−1. These results indicated that AmB was effective in the therapy of I. multifiliis infection, but the safety concentration margin is relatively narrow. Further efforts aiming to decrease the toxicity and improve the therapeutic profile remain to be needed.
An epigenetic mechanism has been suggested to explain the effects of the maternal diet on the development of disease in offspring. The present study aimed to observe the effects of a maternal high-lipid, high-energy (HLE) diet on the DNA methylation pattern of male offspring in mice. Female C57BL/6J mice were fed an HLE diet during gestation and lactation. The genomic DNA methylations at promoter sites of genes in the liver, mRNA and protein levels of selected genes related to lipid and glucose metabolism were measured by microarray, real-time PCR and Western blot. The results indicated that the percentage of methylated DNA in offspring from dams that were fed an HLE diet was significantly higher than that from dams that were fed a chow diet, and most of these genes were hypermethylated in promoter regions. The nuclear protein content and mRNA levels of hypermethylated genes, such as PPARγ and liver X receptor α (LXRα), were decreased significantly in offspring in the HLE group. The results suggested that the DNA methylation profile in adult offspring livers was changed by the maternal HLE diet during gestation and lactation.
The present study aimed to compare the effects of a general dietary intervention and an intervention with low glycaemic load (GL) on glycaemic control, blood lipid metabolism and pregnancy outcomes in women with gestational diabetes mellitus.
Participants were randomly assigned to two groups, receiving either an individualized general dietary intervention (Control group) or an intensive low-GL intervention (Low-GL group) every two weeks, from 24–26 weeks of gestation to delivery.
The Center of Maternal Primary Care in Guangdong General Hospital, China.
Ninety-five women with gestational diabetes mellitus were enrolled from June 2008 to July 2009.
After the intervention, both groups significantly decreased their dietary intakes of energy, fat and carbohydrate. The Low-GL group had significantly lower values for GL (122 v. 136) and glycaemic index (50 v. 54) but greater dietary fibre intake (33 v. 29 g/d) than did the Control group (all P<0·01). Significantly greater decreases in fasting plasma glucose (−0·33 v. −0·02 mmol/l, P<0·01) and 2 h postprandial glucose (−2·98 v. −2·51 mmol/l, P<0·01), significantly lower increases in total cholesterol (0·12 v. 0·23 mmol/l) and TAG (0·41 v. 0·56 mmol/l) and a significantly lower decrease in HDL cholesterol (−0·01 v. −0·11 mmol/l) were also observed in the Low-GL group compared with the Control group (all P<0·05). There were no significant differences in body weight gain, birth weight or other maternal–fetal perinatal outcomes between the two groups.
The low-GL targeted dietary intervention outperformed the general dietary intervention in glycaemic control and the improvement of blood lipid levels in women with gestational diabetes mellitus.
To date, there has been little improvement in cryopreservation of bull sperm due to lack of understanding of the freezing mechanisms. Therefore, this study set out to investigate expression levels of fertility-associated proteins in bull sperm, and in particular the relationship between the 90 kDa heat-shock protein (HSP90) and the sperm characteristics after freezing–thawing. Semen was collected from eight Holstein bulls by artificial vagina. Characteristics of these fresh semen, including sperm motility, morphology, viability and concentration, were evaluated. Sperm quality was also assessed after freezing–thawing. Eight ejaculates were divided into two groups based on freezing resistance and sperm motility. Sperm proteins were extracted and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and western blotting were performed. SDS-PAGE results showed that there was substantial diversity in 90 kDa proteins in the frozen–thawed sperm and HSP90 was confirmed as one of the 90 kDa proteins by western blot. This study indicated that HSP90 expression correlated positively with sperm quality. The amount of expressed 90 kDa proteins in the high freezing resistance (HFR) group was significantly higher than that in the low freezing resistance (LFR) group (P < 0.05). Thus, higher expression of HSP90 could probably lead to the higher motility and freezing resistance of sperm found after freezing–thawing. Therefore, we concluded that level of HSP90 expression could be used to predict reliably and simply the freezing resistance of bull sperm.
Structure and demographics in many tropical forests is changing, but the causes of these changes remain unclear. We studied 5 y (2005–2010) of species turnover, recruitment, mortality and population change data from a 20-ha subtropical forest plot in Dinghushan, China, to identify trends in forest change, and to test whether tree mortality is associated with intraspecific or interspecific competition. We found the Dinghushan forest to be more dynamic than one temperate and two tropical forests in a comparison of large, long-term forest dynamics plots. Within Dinghushan, size-class distributions were bell-shaped only for the three most dominant species and reverse J-shaped for other species. Bell-shaped population distributions can indicate a population in decline, but our data suggest that these large and long-lived species are not in decline because the pattern is driven by increasing probabilities of transition to larger size class with increasing size and fast growth in saplings. Spatially aggregated tree species distributions were common for surviving and dead individuals. Competitive associations were more frequently intraspecific than interspecific. The competition that induced tree mortality was more associated with intraspecific than interspecific interactions. Intraspecific competitive exclusion and density-dependence appear to play important roles in tree mortality in this subtropical forest.
Lutein and zeaxanthin are thought to decrease the incidence of age-related macular degeneration (AMD); however, findings have been inconsistent. We conducted a systematic literature review and meta-analysis to evaluate the relationship between dietary intake of lutein and zeaxanthin and AMD risk. Relevant studies were identified by searching five databases up to April 2010. Reference lists of articles were retrieved, and experts were contacted. Literature search, data extraction and study quality assessment were performed independently by two reviewers and results were pooled quantitatively using meta-analysis methods. The potential sources of heterogeneity and publication bias were also estimated. The search yielded six longitudinal cohort studies. The pooled relative risk (RR) for early AMD, comparing the highest with the lowest category of lutein and zeaxanthin intake, was 0·96 (95 % CI 0·78, 1·17). Dietary intake of these carotenoids was significantly related with a reduction in risk of late AMD (RR 0·74; 95 % CI 0·57, 0·97); and a statistically significant inverse association was observed between lutein and zeaxanthin intake and neovascular AMD risk (RR 0·68; 95 % CI 0·51, 0·92). The results were essentially consistent among subgroups stratified by participant characteristics. The findings of the present meta-analysis indicate that dietary lutein and zeaxanthin is not significantly associated with a reduced risk of early AMD, whereas an increase in the intake of these carotenoids may be protective against late AMD. However, additional studies are needed to confirm these relationships.
The correlation of glutathione S-transferase (GST) M1/T1 genetic polymorphisms with oxidative stress-related chronic diseases was proved recently. The aim of the present study was to investigate the association of GSTM1/T1 genetic polymorphisms with antioxidant biomarkers and consumption of fruits and vegetables (F&V) in healthy subjects. In this study, for conducting a 3 d dietary survey, 190 healthy adults were recruited. After DNA extraction, a multiple PCR method was used for GSTM1/T1 genotyping. A spectrophotometer method was applied for the determination of plasma total antioxidant capacity (T-AOC), vitamin C level and erythrocyte GST enzyme activity. A general linear model was used to compare the mean values of antioxidant parameters for different GSTM1/T1 genotypes and consumption of F&V. Polymorphisms of GSTM1/T1 had no effects on plasma T-AOC and vitamin C levels. Deletion of the GSTM1 gene decreased the erythrocyte GST activity. There was correlation between plasma T-AOC and consumption of F&V in the GSTM1− or GSTT1+ subjects. A similar pattern was evident for erythrocyte GST activity in the GSTM1− subjects. No association was found among consumption of F&V and GSTM1/T1 genotypes and plasma vitamin C level. Different consumption of F&V had no impact on plasma T-AOC and vitamin C levels in the GSTM1−/GSTT1+ or GSTM1−/GSTT1− subjects. The erythrocyte GST activity was more sensitive to consumption of F&V in the individuals with the GSTM1−/GSTT1+ genotype. Association was found among GSTM1/T1 genotypes, antioxidant parameters and consumption of F&V. Large-scale and multiple ethnic studies are needed to further evaluate the relationship.
The oocyte is known from recent studies in the mouse, cow, sheep and human to be a central regulator of follicular cell function. However, in the pig, little information is known about the regulation of cumulus expansion by oocyte-secreted factors and oocyte quality. We investigated the possible effects of oocyte-secreted factors during in vitro maturation on cumulus expansion and on porcine oocytes as judged by subsequent embryonic development after parthenogenetic activation. Cumulus–oocyte complexes (COC) from antral follicles of pig ovaries collected from a local abattoir were divided into control and treatment groups and were cultured in tissue culture medium 199 supplemented with follicle-stimulating hormone. Treatment groups consisted of increasing numbers of denuded oocytes (DO) co-cultured with COC (at ratios of COC to DO of 1:1, 1:2, 1:3, 1:4 and 1:5). After incubation for 44 h, cumulus expansion and maturation rates were assessed and oocytes were activated parthenogenetically. Cumulus expansion in the 1 COC:4 DO and 1 COC:5 DO groups was low and altered because full dispersion of the outer layer did not occur. Cell viability was not affected, as measured by the automated cell counter, but scanning electron microscopy revealed only a scanty extracellular matrix. Blastocyst rate was significantly higher in the 1 COC:4 DO (34.4%) and in the 1 COC:5 DO (34.9%) groups (p < 0.05) when compared with other groups. Maturation rate, cleavage rate and total cell number showed no significant difference between control and treatment groups. Amplification by reverse transcription polymerase chain reaction (RT-PCR) showed up-regulation of growth differentiation factor 9 (GDF9) in the cumulus cells in the 1 COC:4 DO group at 44 h. We conclude that denuded porcine oocytes could improve the maturation of COC as evidenced by increased blastocyst development in the 1 COC:4 DO, even though cumulus expansion was poor. This improvement could be a result of the GDF9 up-regulation.