Little is known about the effects of dietary patterns on prevalent pre-eclampsia in Chinese population. This study aimed to investigate the associations between dietary patterns and the odds of pre-eclampsia among Chinese pregnant women. A 1:1 age- and gestational week-matched case–control study was conducted between March 2016 and February 2019. A total of 440 pairs of pre-eclampsia cases and healthy controls were included. Dietary intakes were assessed by a seventy-nine-item FFQ and subsequently grouped into twenty-eight distinct groups. Factor analysis using the principal component method was adopted to derive the dietary patterns. Conditional logistic regression was used to analyse the associations of dietary patterns with prevalent pre-eclampsia. We identified four distinct dietary patterns: high fruit-vegetable, high protein, high fat-grain and high salt-sugar. We found that high fruit-vegetable dietary pattern (quartile (Q)4 v. Q1, OR 0·71, 95 % CI 0·55, 0·92, Ptrend = 0·013) and high protein dietary pattern (Q4 v. Q1, OR 0·72, 95 % CI 0·54, 0·95, Ptrend = 0·011) were associated with a decreased odds of pre-eclampsia in Chinese pregnant women. Whereas high fat-grain dietary pattern showed a U-shaped association with pre-eclampsia, the lowest OR was observed in the third quartile (Q3 v. Q1, OR 0·75, 95 % CI 0·57, 0·98, Ptrend = 0·111). No significant association was observed for high salt-sugar dietary pattern. In conclusion, pregnancy dietary pattern characterised by high fruit-vegetable or high protein was found to be associated with a reduced odds of pre-eclampsia in Chinese pregnant women.

We perform a theoretical investigation of the instability of a helical vortex filament beneath a free surface in a semi-infinite ideal fluid. The focus is on the leading-order free-surface boundary effect upon the equilibrium form and instability of the vortex. This effect is characterised by the Froude number $F_r = U(gh^*)^{-{1}/{2}}$ where $g$ is gravity, and $U = \varGamma /(2{\rm \pi} b^*)$ with $\varGamma$ being the strength, $2{\rm \pi} b^*$ the pitch and $h^*$ the centre submergence of the helical vortex. In the case of $F_r \rightarrow 0$ corresponding to the presence of a rigid boundary, a new approximate equilibrium form is found if the vortex possesses a non-zero rotational velocity. Compared with the infinite fluid case (Widnall, J. Fluid Mech., vol. 54, no. 4, 1972, pp. 641–663), the vortex is destabilised (or stabilised) to relatively short- (or long-)wavelength sub-harmonic perturbations, but remains stable to super-harmonic perturbations. The wall-boundary effect becomes stronger for smaller helix angle and could dominate over the self-induced flow effect depending on the submergence. In the case of $F_r > 0$, we obtain the surface wave solution induced by the vortex in the context of linearised potential-flow theory. The wave elevation is unbounded when the $m$th wave mode becomes resonant as $F_r$ approaches the critical Froude numbers ${\mathcal {F}} (m) = (C_0^*/U)^{-1} (mh^*/b^*)^{-{1}/{2}}$, $m=1, 2, \ldots,$ where $C_0^*$ is the induced wave speed. We find that the new approximate equilibrium of the vortex exists if and only if $F_r < {\mathcal {F}}(1)$. Compared with the infinite fluid and $F_r \rightarrow 0$ cases, the wave effect causes the vortex to be destabilised to super-harmonic and long-wavelength sub-harmonic perturbations with generally faster growth rate for greater $F_r$ and smaller helix angle.

Few studies have suggested that long-term adherence to low-carbohydrate diets (LCD) may affect maternal glucose metabolism in Western countries. We aimed to investigate the association between LCD during pregnancy and glucose metabolism in a Chinese population. A total of 1018 women in mid-pregnancy were recruited in 2017–2018. Participants underwent a 75 g oral glucose tolerance test (OGTT). Daily dietary intakes over the past month were accessed using a validated FFQ. The overall, animal and vegetable LCD scores which represent adherence to different low-carbohydrate dietary patterns were calculated. Mixed linear regression and generalised linear mixed regression were conducted to evaluate the associations between LCD scores and maternal glucose metabolism. Of the 1018 subjects, 194 (19·1 %) were diagnosed with gestational diabetes mellitus (GDM). The overall LCD score (β: 0·024, se 0·008, PFDR = 0·02) and animal LCD score (β: 0·023, se 0·008, PFDR = 0·02) were positively associated with OGTT 1-h glucose. No significant associations were found between the three different LCD scores with fasting plasma glucose, OGTT 2-h glucose, or insulin resistance, respectively. Compared with the lowest quartile, the crude OR of GDM for the highest quartile were 1·84 (95 % CI 1·14, 2·95) for overall LCD score (Pfor trend = 0·02) and 1·56 (95 % CI 1·00, 2·45) for animal LCD score (Pfor trend = 0·02). However, these associations became non-significant after adjustment for covariates. In conclusion, a low-carbohydrate dietary pattern with high animal protein and fat is associated with higher postprandial 1-h glucose levels in Chinese pregnant women.

Deformation twins have a major role in the microstructure evolution of hexagonal close packed (HCP) metals. Voids are common defects in metals and have a significant impact on their properties. In this work, using molecular dynamics, a tension simulation of single-crystal titanium (Ti) with different void sizes under uniaxial stress conditions was performed. The results showed that the evolution and dominance of the $\left\{ {10\bar{1}2} \right\}$ twin system using the Henning potential was not consistent with the Schmid criterion when the single-crystal Ti contained void defects. From a microscopic perspective, the authors analyzed the relationship between the nucleation and growth of twins and the emission of dislocation loops. The authors found that the existence of voids not only contributes to the emission of dislocation loops but also hinders the movement of these loops. With the increase in void size, the peak dislocation density of ${1 \over 3}\left\langle {\bar{1}100} \right\rangle$ partial dislocation loops decreased. This work is helpful to further investigate the nucleation and evolution of tension twins and to form an effective growth criterion for twins to study the twinning process of HCP metals during plastic deformation.

Previous studies have suggested that daidzein's metabolites, equol and O-desmethylangolensin (O-DMA), rather than daidzein itself may contribute to the beneficial effects of soya foods in the prevention of CVD. The present study aims to assess the proportion of equol and O-DMA producers, and to compare differences in anthropometric factors, serum lipids, glucose and uric acid between producers and non-producers in Chinese adults aged 20–69 years. For the present cross-sectional study, 202 subjects (100 women and 102 men) were recruited. Twenty-four-hour urinary daidzein and its metabolites were determined in these subjects while on their usual diet and again after a 3-d isoflavone challenge. Fasting serum lipids, glucose and uric acid were examined on their usual diet. Three days of 24 h dietary recalls were used to assess dietary intakes. Of the 202 subjects, 27 (13·4 %) and 27 (13·4 %) excreted equol and O-DMA on their usual diet, and 101 (50 %) and 94 (46·5 %) produced equol and O-DMA after a load of 80 mg/d isoflavones. Equol producers showed lower serum uric acid ( − 10·2 %, P = 0·001), TAG ( − 29·5 %, P = 0·007) and waist:hip ratio ( − 2·6 %, P = 0·032), and tended to have higher HDL cholesterol (6·3 %, P = 0·069) compared with equol non-producers. There were no significant differences in serum lipids, glucose and uric acid between O-DMA producers and non-producers. In conclusion, equol phenotypes might influence cardiovascular risk.