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This study aimed to describe diet quality of pregnant women and explore the association between maternal diet and the prevalence of low birth weight (LBW) and small for gestational age (SGA). A total of 3856 participants from a birth cohort in Beijing, China, were recruited between June 2018 and February 2019. Maternal diet in the first and second trimesters was assessed by the Chinese diet balance index for pregnancy (DBI-P), using data collected by the inconsecutive 2-d 24-h dietary recalls. Logistic regressions were performed to explore the independent effects of DBI-P components on LBW and SGA. The prevalence of LBW and SGA was 3·8% and 6·0%, respectively. Dietary intakes of the participants were imbalanced. The proportions of participants having insufficient intake of vegetables (87·3% and 86·6%), dairy product (95·9% and 96·7%) and aquatic foods (80·5% and 85·3%) were high in both trimesters. The insufficiency of fruit intake was more severe in the second (85·2%) than that in the first trimester (22·5%) (P < 0·05). After adjusting for potential confounders, the intake of fruits and dairy in the second trimester was negatively associated with the risk of LBW (OR = 0·850, 95% CI: 0·723, 0·999) and SGA (OR = 0·885, 95% CI: 0·787, 0.996), respectively. Sufficient consumption of fruits and dairy products in pregnancy may be suggested in order to prevent LBW and SGA.
Let $\mathbb {N}$ be the set of all nonnegative integers. For $S\subseteq \mathbb {N}$ and $n\in \mathbb {N}$, let $R_S(n)$ denote the number of solutions of the equation $n=s_1+s_2$, $s_1,s_2\in S$ and $s_1<s_2$. Let A be the set of all nonnegative integers which contain an even number of digits $1$ in their binary representations and $B=\mathbb {N}\setminus A$. Put $A_l=A\cap [0,2^l-1]$ and $B_l=B\cap [0,2^l-1]$. We prove that if $C \cup D=[0, m]\setminus \{r\}$ with $0<r<m$, $C \cap D=\emptyset $ and $0 \in C$, then $R_{C}(n)=R_{D}(n)$ for any nonnegative integer n if and only if there exists an integer $l \geq 1$ such that $m=2^{l}$, $r=2^{l-1}$, $C=A_{l-1} \cup (2^{l-1}+1+B_{l-1})$ and $D=B_{l-1} \cup (2^{l-1}+1+A_{l-1})$. Kiss and Sándor [‘Partitions of the set of nonnegative integers with the same representation functions’, Discrete Math.340 (2017), 1154–1161] proved an analogous result when $C\cup D=[0,m]$, $0\in C$ and $C\cap D=\{r\}$.
The relationship between SFA consumption and the risk of overweight/obesity remains unclear. Epidemiological evidence is lacking among Chinese population. This study aimed to investigate the association between individual dietary SFA intake and the risk of overweight/obesity in Chinese adults. Data from 8465 adults with BMI < 24 kg/m2 at entry in the China Health and Nutrition Survey (1989–2011) were analysed. Three-day 24-h dietary records were used to collect dietary data. Cox proportional hazards regression models were constructed to estimate hazard ratios (HR) and 95 % CI for the risk of developing overweight or obesity. A total of 3171 incident cases of overweight/obesity were identified (1649 for women and 1522 for men) during a median of 11 years of follow-up. Compared with the lowest category, the intake of total SFA (TSFA) showed no significant association with the risk of overweight/obesity. However, an increased risk of overweight/obesity was observed with a higher intake of medium chain SFA (MCSFA) (Ptrend = 0·004), especially decanoic acid (10:0) (HR was 1·25 (95 % CI 1·10, 1·42) comparing the highest category with the reference group; Ptrend < 0·001), whereas an inverse relationship was observed for hexanoic acid (6:0) consumption; compared with non-consumers, 6:0 intake was associated with 32 % lower risk of overweight/obesity (HR: 0·68 (95 % CI 0·56, 0·84); Ptrend < 0·001). Overall, the intake of subtypes of MCSFA but not TSFA was associated with the risk of overweight/obesity. Increasing hexanoic acid (6:0) and limiting decanoic acid (10:0) consumption may be protective for overweight/obesity among Chinese population.
In this study, we argue that foreign subsidiaries may benefit from the corporate strategies of multinational enterprises (MNEs) in different ways in terms of knowledge transfer and strategic flexibility. From this viewpoint, we explore the relationship between product diversification and financial performance of their subsidiaries under the condition of MNE geographic diversification. Using panel data on foreign subsidiaries in European countries from 2006 to 2011, we find a U-shaped relationship between product diversification and subsidiary performance and the joint effect of product and geographic diversification. Given the importance of transition economies in international business today, we conducted a subsample test contrasting the results based on the transitional (Central and Eastern European) versus Western European countries. The contrasting results provide important implications for other transition economies like China. We validate the relationship in several ways in our robustness tests.
From a coopetition perspective, we differentiate between a multinational enterprise's product-similar subsidiary network and product-different subsidiary network in a host country. We argue that the product-similar network will have a curvilinear (inverted U-shaped) effect on foreign subsidiary performance, whereas the product-different network will produce a monotonic (positive) effect. Moreover, we introduce host-country economic advantage and intangible resource of the subsidiary as moderators into the relationship between subsidiary network and performance. Using longitudinal panel data of foreign subsidiaries, we find evidence that when host-country economic advantage is large, and the level of intangible asset intensity is high, the inverted U-shaped effect of product-similar subsidiary network is less pronounced. Moreover, host-country economic advantage and intangible asset intensity both enhance the positive effect of product-different subsidiary network. However, the moderating effect of intangible asset intensity is opposite to our prediction.
Palladium (Pd) and gold (Au) nanoparticles (NPs) hybridized on two types of carbon supports, graphene and granular activated carbon (GAC), were shown to be promising catalysts for the sustainable hydrodehalogenation of aqueous trichloroethylene (TCE). These catalysts are capable of degrading TCE more rapidly than commercial Pd-on-GAC catalysts. The catalysts were synthesized at room temperature without the use of any environmentally unfriendly chemicals. Pd was chosen for its catalytic potency to break down TCE, while Au acts as a strong promoter of the catalytic activity of Pd. The results indicate that both graphene and GAC are favorable supports for the NPs due to high surface-to-volume ratios, unique surface properties, and the prevention of NP aggregation. The properties of NP catalysts were characterized using electron microscopy and spectroscopy techniques. The TCE degradation results indicate that the GAC-supported catalysts have a higher rate of TCE removal than the commercial Pd-on-GAC catalyst, and the degradation rate is greatly increased when using graphene-supported samples.
The in vivo effects of administering free and microencapsulated Lactobacillus plantarum LIP-1 cells (2·0×109 colony-forming units/d) were evaluated in high-fat-diet-induced hyperlipidaemic rats. Results from real-time quantitative PCR targeting to LIP-1 cells showed a higher colon colonisation count of LIP-1 in the rats receiving microencapsulated cells compared with free cells (P<0·05). Moreover, the microencapsulated LIP-1 treatment resulted in a more obvious lipid-lowering effect (P<0·05). Meanwhile, their faecal samples had significantly less lipopolysaccharide-producing bacteria (especially Bilophila, Sutterella and Oscillibacter) and mucosa-damaging bacteria (Bilophila and Akkermansia muciniphila), whereas significantly more SCFA-producing bacteria (P<0·05) (namely Lactobacillus, Alloprevotella, Coprococcus, Eubacterium and Ruminococcus) and bacteria that potentially possessed bile salt hydrolase activity (Bacteroides, Clostridium, Eubacterium and Lactobacillus), and other beneficial bacteria (Alistipes and Turicibacter). Further, Spearman’s correlation analysis showed significant correlations between some of the modulated gut bacteria and the serum lipid levels. These results together confirm that microcapsulation enhanced the colon colonisation of LIP-1 cells, which subsequently exhibited more pronounced effects in improving the gut microbiota composition of hyperlipidaemic rats and lipid reduction.
A self-made die with large cross section (180.2 × 22.2 mm) for equal channel angular pressing (ECAP) was used to study the influence of two different pressing routes (CX and CY) on refining homogeneity of high-purity aluminum plates. Microstructures were investigated by optical microscopy (OM) and electron back scatter diffraction (EBSD) methods, and micro-hardness and tensile tests were taken to evaluate deformation degree across the cross section and mechanical properties, respectively. The results indicate that pressing routes of ECAP have a great influence on structure homogeneity of plate samples. The route CY leads to fine grains with better homogeneity because the same deformation direction is taken through each pass. Coarse columnar crystals with 3–4 mm change to 68.6 μm nearly equiaxed grains and a strong cube texture forms after four CY passes, and corresponding mechanical properties increase by a factor compared to as-cast plate.
A generalised Hermite spectral method for Fisher's equation in genetics with different asymptotic solution behaviour at infinities is proposed, involving a fully discrete scheme using a second order finite difference approximation in the time. The convergence and stability of the scheme are analysed, and some numerical results demonstrate its efficiency and substantiate our theoretical analysis.
The present study aimed to investigate the prevalence of metabolic syndrome (MetS) in 7- to 17-year-old children and adolescents in China and to examine the relationship between MetS and its associated early-life factors.
Design
Data were collected using a standard parent/guardian questionnaire in a face-to-face interview. Each participant underwent a complete anthropometric evaluation. MetS was defined according to the criteria of the International Diabetes Federation (IDF; 2007) for children and adolescents.
Setting
Guangzhou, a large city in South China, September 2013.
Subjects
A total of 1770 children and adolescents were enrolled in the study, including 913 girls (51·6 %) and 857 boys (48·4 %).
Results
The overall prevalence of MetS in children and adolescents was 1·1 % (n 19), which was higher in boys (1·4 %) than in girls (0·8 %). Multivariate analysis indicated that high birth weight was significantly associated with abdominal obesity (OR=2·86; 95 % CI 1·62, 5·06) and MetS (OR=3·61; 95 % CI 1·33, 9·82). Furthermore, >6 months of maternal breast-feeding was inversely associated with MetS (OR=0·39; 95 % CI 0·16, 0·98).
Conclusion
Based on IDF criteria, the prevalence of MetS among southern Chinese children was significantly lower than that in other populations. High birth weight was significantly associated with abdominal obesity and MetS, and breast-feeding for longer than 6 months was inversely associated with MetS in South China.
The authors investigated the effects of annealing in Ar atmosphere at different temperatures (350–1100 °C) on the densification and leakage current characteristics of thermally oxidized SiO2 films on n-type 4H-SiC. A strong correlation between densification improvement and leakage current reduction was observed. Densification of the SiO2 films, which were characterized by spectroscopic ellipsometry, Fouriertransform infrared spectroscopy and atomic force microscopy, can be significantly improved after annealing at moderate temperature (600 °C). The leakage current is decreased by two orders of magnitude of the SiO2 thin film after annealing at 600 °C. Based on the studies, SiO2 film of the highest quality can be obtained after annealing at 600 °C. Improvements in the quality of the SiO2 thin films after annealing at 600 °C may be explained by the consumption and formation of carbon-related and oxygen-related defects during annealing.
Stable, aqueous, red-to-near infrared emission is critical for the use of silicon nanoparticles (Si NPs) in biological fluorescence assays, but such Si NPs have been difficult to attain. We report a synthesis and surface modification strategy that protects Si NPs and preserves red photoluminescence (PL) in water for more than 6 mo. The Si NPs were synthesized via high temperature reaction, liberated from an oxide matrix, and functionalized via hydrosilylation to yield hydrophobic particles. The hydrophobic Si NPs were phase transferred to water using the surfactant cetyltrimethylammonium bromide (CTAB) with retention of red PL. CTAB apparently serves a double role in providing stable, aqueous, red-emitting Si NPs by (i) forming a hydrophobic barrier between the Si NPs and water and (ii) providing aqueous colloidal stability via the polar head group. We demonstrate preservation of the aqueous red emission of these Si NPs in biological media and examine the effects of pH on emission color.
Pearlitic transformation in an ultrafine-grained (UFG) hypereutectoid steel was investigated. The steel was a plain carbon steel containing 1.0 wt% C and very few other elements. The UFG samples were prepared by thermomechanical treatment, and an average grain size of approximately 1 μm was achieved. The pearlitic transformation was conducted by heating the UFG samples at 1023 K for different times and then cooling in air. A new pearlitic transformation phenomenon was observed: traditional lamellar pearlite can be observed only when the grain size increases to a dimension larger than approximately 4 μm, which is a critical value. When grain size is smaller than this value, the pearlitic transformation occurs in the form of divorced eutectoid, and the microstructure is the ferrite matrix with granular cementite. This research indicates that grain size has a great influence on pearlitic transformation by shortening the diffusion distance and increasing the diffusion rate of carbon atoms in the UFG steel.
Vanadium-beard bone coal is one of important vanadium resources in China. to extract vanadium tailings from Stone coal is prduced after extracted vanadium from stone coal through the roasting, leaching and other processes. About 120-150 tons of tailings will be produced in extracting 1 ton of vanadium pentoxide. A lot of tailings that are willfully piled up have caused serious environmental pollution and wasting of resources; it is therefore necessary to realize its resource utilization. This study increases the activity of vanadium tailings by means of alkali fusion, and then uses different alkali activators to react with vanadium tailings so that geopolymer with high value added is produced. Sample of geopolymer is acquired from mixture containing vanadium tailings, alkali activators, water and a little sodium aluminate through compression-molding process under 20MPa pressure. After cured in room temperature for three days, the maximum compressive strength of the sample can reach 36.2MPa. XRD analysis indicates: quartz, the major crystal phase in vanadium tailings is decomposed and the activity of vanadium tailings is heightened. FTIR and SEM analyses show: structural change having important impact on the mechanical strength of geopolymer occurred during the process of vanadium tailings generating geopolymer.
The mechanical properties of arrays of nominally vertically aligned carbon nanotubes, often referred to as turfs, have been measured using nanoindentation and the electrical properties have been measured using electrical contact resistance (ECR) nanoindentation. The elastic properties do not vary significantly between the top and the bottom of the same carbon nanotube turf. Within a single turf the lateral spatial variation is less than 10% when volumes of μm's are probed with the indenter, indicating that each turf can be treated mechanically as continuum on this scale. The electrical properties vary significantly within a single turf on the same scale. This suggests that the use of average mechanical properties for a given vertically aligned turf should be suitable for design purposes without the need to account for spatial variation in structure, and variations in mechanical properties on the micrometer scale are not dependent on spatially distinct defects. However, local contact behavior appears to dominate the electrical behavior on this same length scale.
Biological fabrication approaches were used to enhance the performance of a dye-sensitized solar cell (DSSC) device stack for the conversion of light to electricity. Diatoms are single-celled algae that make silica shells called frustules that possess periodic structures ordered at the micro- and nanoscale. Nanostructured TiO2 was deposited onto the frustule biosilica of the diatom Pinnularia sp. Poly-L-lysine (PLL) conformally adsorbed onto surface of the frustule biosilica. The hydrolysis and condensation of soluble Ti-BALDH to TiO2 by PLL-adsorbed diatom biosilica deposited 0.77 ± 0.05 g TiO2/g SiO2 onto the diatom biosilica. The periodic pore array of the diatom frustule served as a template for the deposition of ˜20 nm TiO2 nanoparticles, which completely filled the 200 nm frustule pores and also coated the frustule outer surface. This material was then integrated into the DSSC device stack. Specifically, a single layer of diatom-TiO2 frustules was deposited to surface coverage 100μg/cm2 on top of the 25 nm anatase TiO2 nanocrystal layer (2.5 mg/cm2) that was doctor-bladed onto conductive FTO glass. The composite structure was thermally annealed in air at 400 °C, followed by addition of N719 dye, I3-/3I- liquid electrolyte, and semi-transparent Pt back electrode sputter coated on FTO glass. The solar cell efficiency increased from 0.20% to 0.70% when the diatom-TiO2 layer was added to anatase TiO2 base layer of the semi-transparent device. The increase in efficiency cannot be attributed solely to the added TiO2, because the amount of TiO2 in the diatom-TiO2 layer contributed to only 3% of the total TiO2 in the device. Instead, it is proposed that the diatom-TiO2 layer may have helped to improve photon capture within the DSSC because of its periodic structure and high dielectric contrast.
We report the synthesis of Zn-doped TiO2 nanowires by a solution-based process. The synthesis takes place at 200°C in an alkali solution and results in both nanowire and nanoparticle precipitates. Several transmission electron microscopy techniques were used to characterize the resulting precipitates: diffraction patterns and high resolution phase contrast images provided identification of the crystalline phase of the material as well as insights into the resulting lattice parameters, energy dispersive x-ray spectroscopy allowed identification of constituent elements, and electron energy loss spectroscopy permitted quantification of relative concentrations of hydroxyl and lattice-type oxygen bonding. In addition, scanning electron microscope images provide overall perspective of the growth uniformity and morphology.
Diatoms are unicellular, photosynthetic microalgae that live in marine and freshwater environments. The cell walls of diatoms are composed of biosilica and have exceedingly hierarchical ornate nanostructures. Consequently, these nanostructures have long been regarded as the paradigm for future silica nanotechnology. We have coated diatom Pinnularia sp. biosilica with a thin film of CdS using a chemical bath deposition technique. Possible uses for these CdS coated diatoms include the development of new nanodevice fabrication techniques and optoelectronic applications. Electron microscopy techniques were utilized to study their morphologies. Their electrical characteristics were investigated using an Agilent 4156C precision semiconductor parameter analyzer and a Cascade probe station. The CdS coating was found to be dense, adherent and nanostructured. The diatoms coated with CdS exhibited both metallic and semiconductor diode behavior.
Microbial fuel cells (MFCs) use microorganisms to simultaneously break down organic materials and generate electricity. One of the greatest challenges in the practical application of MFCs is to sufficiently increase their power generation. Nanomodified graphite carbon anodes were prepared for use in MFCs to enhance the electron transport from the microbes to the electrode. Nanomodification to the anodes included growth of nanoparticles and multi-walled carbon nanotubes (MWCNTs). Nanoparticles of various metals, including Au, Ni, Pd, and Fe, were synthesized through thermal annealing and Fe catalyzed MWCNTs were synthesized through chemical vapor deposition. Power density was measured in MFCs for each type of nanomodified electrodes. Significant increase in power density was observed for the MFC with anodes decorated with MWCNTs (with 50-100nm diameters).
Interconnected TiO2 nanobelt networks were prepared to serve as anode materials. The aim is to enhance the electron transport through the anode of dye-sensitized solar cells. Using an alkaline hydrothermal procedure and by controlling the reaction time, two kinds of nanostructures were synthesized: TiO2 nanobelts and the mixture of TiO2 nanobelts/TiO2 nanoparticles. This investigation suggests that TiO2 nanobelts are the result of the rearrangement of the [Ti(OH)6]2- monomers formed during the erosion process of TiO2 nanoparticles. The nanostructures of as-synthesized nanobelts were woven and interconnected, resulting in networks after an annealing process. Raman analysis indicates that both kinds of nanostructures were pure anatase. Electrical characterization suggests that the conductivities of these TiO2 nanobelt networks were higher than those of the TiO2 nanoparticle films. Under simulated sunlight with an intensity of AM 1.5 G, the solar cells made of TiO2 nanobelt networks show exceptional photocurrent in comparison to those made of TiO2 nanoparticles.