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To evaluate the effects of dietary Ca intake and Ca supplementation during pregnancy on low birth weight (LBW) and small for gestational age (SGA) infants.
Design:
A birth cohort study was conducted in 2010–2012 at the Gansu Provincial Maternity and Child Care Hospital in Lanzhou, China.
Setting:
A birth cohort study.
Participants:
Totally, 9595 pregnant women who came to the hospital for delivery at 20 weeks of gestation or more, and who were 18 years of age or older.
Results:
Compared with non-users, Ca supplement users had a reduced risk of LBW infants (OR = 0·77, 95 % CI: 0·63, 0·95) and a reduced risk of nulliparous women giving birth to LBW infants (OR = 0·75, 95 % CI: 0·58, 0·98) (P < 0·05). More specifically, both the use of Ca supplement before conception and during pregnancy (OR = 0·44, 95 % CI: 0·19, 0·99) and during pregnancy only (OR = 0·80, 95 % CI: 0·65, 0·99) had the main effect of reducing risk of nulliparous women giving birth to LBW infants (P < 0·05). There was no association between Ca supplementation and SGA (OR = 0·87, 95 % CI: 0·75, 1·01) (P > 0·05). However, higher dietary Ca intake during pregnancy decreases the risk of both LBW (quartile 2: OR = 0·72, 95 % CI: 0·55, 0·94; quartile 3: OR = 0·68, 95 % CI: 0·50, 0·62) and SGA infants (quartile 2: OR = 0·77, 95 % CI: 0·63, 0·95; quartile 3: OR = 0·71, 95 % CI: 0·57, 0·88, quartile 4: OR = 0·71, 95 % CI: 0·57, 0·88) (P < 0·05).
Conclusions:
Ca supplementation and adequate dietary intake of Ca during pregnancy are associated with a decreased risk of LBW infants born to nulliparous women.
The ablation and acceleration of diamond-like high-density carbon foils irradiated by thermal X-ray radiations are investigated with radiation hydrodynamics simulations. The time-dependent front of the ablation wave is given numerically for radiation temperatures in the range of 100–300 eV. The mass ablation rates and ablation pressures can be derived or implied from the coordinates of ablation fronts, which agree well with reported experiment results of high-density carbon with radiation temperatures Trad in the range of 160–260 eV. It is also found that the $T_{{\rm rad}}^3$ scaling law for ablation rates does not apply to Trad above 260 eV. The trajectories of targets and hydrodynamic efficiencies for different target thicknesses can be derived from the coordinates of ablation fronts using a rocket model and the results agree well with simulations. The peak hydrodynamic efficiencies of the acceleration process are investigated for different foil thicknesses and radiation temperatures. Higher radiation temperatures and target thicknesses result in higher hydrodynamic efficiencies. The simulation results are useful for the design of fusion capsules.
The microbiota–gut–brain axis, especially the microbial tryptophan (Trp) biosynthesis and metabolism pathway (MiTBamp), may play a critical role in the pathogenesis of major depressive disorder (MDD). However, studies on the MiTBamp in MDD are lacking. The aim of the present study was to analyze the gut microbiota composition and the MiTBamp in MDD patients.
Methods
We performed shotgun metagenomic sequencing of stool samples from 26 MDD patients and 29 healthy controls (HCs). In addition to the microbiota community and the MiTBamp analyses, we also built a classification based on the Random Forests (RF) and Boruta algorithm to identify the gut microbiota as biomarkers for MDD.
Results
The Bacteroidetes abundance was strongly reduced whereas that of Actinobacteria was significantly increased in the MDD patients compared with the abundance in the HCs. Most noteworthy, the MDD patients had increased levels of Bifidobacterium, which is commonly used as a probiotic. Four Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologies (KOs) (K01817, K11358, K01626, K01667) abundances in the MiTBamp were significantly lower in the MDD group. Furthermore, we found a negative correlation between the K01626 abundance and the HAMD scores in the MDD group. Finally, RF classification at the genus level can achieve an area under the receiver operating characteristic curve of 0.890.
Conclusions
The present findings enabled a better understanding of the changes in gut microbiota and the related Trp pathway in MDD. Alterations of the gut microbiota may have the potential as biomarkers for distinguishing MDD patients form HCs.
Maternal supraphysiological estradiol (E2) environment during pregnancy leads to adverse perinatal outcomes. However, the influence of oocyte exposure to high E2 levels on perinatal outcomes remains unknown. Thus, a retrospective cohort study was conducted to explore the effect of high E2 level induced by controlled ovarian stimulation (COH) on further outcomes after frozen embryo transfer (FET). The study included all FET cycles (n = 10,581) between 2014 and 2017. All cycles were categorized into three groups according to the E2 level on the day of the human Chorionic Gonadotropin trigger. Odds ratios (ORs) and their confidence intervals (CIs) were calculated to evaluate the association between E2 level during COH and pregnancy outcomes and subsequent neonatal outcomes. From our findings, higher E2 level was associated with lower percentage of chemical pregnancy, clinical pregnancy, ongoing pregnancy, and live birth as well as increased frequency of early miscarriage. Preterm births were more common among singletons in women with higher E2 level during COH (aOR1 = 1.93, 95% CI: 1.22–3.06; aOR2 = 2.05, 95% CI: 1.33–3.06). Incidence of small for gestational age (SGA) was more common in both singletons (aOR1 = 2.01, 95% CI: 1.30–3.11; aOR2 = 2.51, 95% CI: 1.69–3.74) and multiples (aOR1 = 1.58, 95% CI: 1.03–2.45; aOR2 = 1.99, 95% CI: 1.05–3.84) among women with relatively higher E2 level. No association was found between high E2 level during COH and the percentage of macrosomia or large for gestational age. In summary, oocyte exposure to high E2 level during COH should be brought to our attention, since the pregnancy rate decreasing and the risk of preterm birth and SGA increasing following FET.
Crystal structure and electronic structure of YMnO3 were investigated by X-ray diffraction and transmission electron microscopy related techniques. According to the density of states (DOS), the individual interband transitions to energy loss peaks in the low energy loss spectrum were assigned. The hybridization of O 2p with Mn 3d and Y 4d analyzed by the partial DOS was critical to the ferroelectric nature of YMnO3. From the simulation of the energy loss near-edge structure, the fine structure of O K-edge was in good agreement with the experimental spectrum. The valence state of Mn (+3) in YMnO3 was determined by a comparison between experiment and calculations.
The objective of the present study was to investigate the effect of curcumin on insulin resistance (IR) and hepatic lipid accumulation in intra-uterine growth restriction (IUGR). Rats with a normal birth weight (NBW) or IUGR were fed basic diets (NBW and IUGR groups) or basic diets supplemented with curcumin (NBW-C and IUGR-C groups) from 6 to 12 weeks. Rats in the IUGR group showed higher levels of glucose and homeostasis model assessment for insulin resistance index (HOMA-IR) (P < 0·05) than in the NBW group. The livers of IUGR rats exhibited higher (P < 0·05) concentration of TAG and lower (P < 0·05) activities of lipolysis enzymes compared with the normal rats. In response to dietary curcumin supplementation, concentrations of serum insulin, glucose and HOMA-IR, pyruvate, TAG, total cholesterol and NEFA in the liver were decreased (P < 0·05). The concentrations of glycogen and activities of lipolysis enzymes in the liver were increased (P < 0·05) in the IUGR-C group compared with the IUGR group. These results were associated with lower (P < 0·05) phosphorylated insulin receptor substrate 1, protein kinase B or Akt, glycogen synthase kinase 3β and expressions of sterol regulatory element binding protein 1 and fatty acid synthase (FASN); decreased expressions for Cd36, sterol regulatory element binding protein 1c (Srebf1) and Fasn; increased (P < 0·05) expression of PPARα; and expressions for Ppara and hormone-sensitive lipase in the liver of IUGR-C rats than the IUGR rats. Maternal malnutrition caused IR and lipid accumulation in the liver. Curcumin supplementation prevented IR by regulating insulin signalling pathways and attenuated hepatic lipid accumulation.
Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.
In this study, a thermal–elastic–plastic finite element model is proposed to investigate the effect of volume energy density on the temperature field, molten pool size, and residual stress distribution in the selective laser melting (SLM) process of Inconel 718 alloy. A temperature-dependent thermal–mechanical property of materials is considered, as well as the properties conversion between powder layer and solidified alloy. Within the scope of the study parameters, the simulated molten pool size increases with increasing volume energy density and exhibits linear growth relationship, which are validated by the experimental results and show a good agreement. In addition, five scanning strategies are adopted to study the effect of these scanning strategies on the residual stress distribution in this research. The results show that the residual stress distribution of SLM Inconel 718 specimen largely depends on the scanning strategy. Finally, to reveal the mechanism of residual stress formation, the restraint bar model is used to further analyze the formation mechanism of residual stress during the SLM process.
Kaolinite can be used for many applications, including the underground storage of gases. Density functional theory was employed to investigate the adsorption of hydrogen molecules on the kaolinite (001) surface. The coverage dependence of the adsorption sites and energetics was studied systematically for a wide range of coverage, Θ (from 1/16 to 1 monolayer). The three-fold hollow site is the most stable, followed by the bridge, top-z and top sites. The adsorption energy of H2 decreased with increasing coverage, thus indicating the lower stability of surface adsorption due to the repulsion of neighbouring H2 molecules. The coverage has obvious effects on hydrogen adsorption. Other properties of the H2/kaolinite (001) system, including the lattice relaxation and changes of electronic density of states, were also studied and are discussed in detail.
Rats with a normal birth weight (NBW) or intra-uterine growth retardation (IUGR) were fed basic diets (NBW and IUGR groups) or basic diets supplemented with curcumin (NC and IC groups) from 6 to 12 weeks. The body weight of IUGR rats was lower (P<0·05) than that of the controls. Rats with IUGR showed higher (P<0·05) concentrations of TNF-α, IL-1β and IL-6; higher (P<0·05) activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in their serum; and increased (P<0·05) concentrations of malondialdehyde (MDA), protein carbonyl (PC) and 8-hydroxy-2'-deoxyguanosine (8-OHDG) in the liver compared with the NBW rats. The livers of IUGR rats exhibited a lower (P<0·05) superoxide dismutase activity and decreased (P<0·05) metabolic efficiency of the hepatic glutathione redox cycle compared with those of the NBW rats. In response to dietary curcumin supplementation, concentrations of inflammatory cytokines and activities of AST and ALT in the serum and MDA, PC and 8-OHDG in the liver were lower (P<0·05), and the hepatic glutathione redox cycle in the liver was improved (P<0·05) in the IC group than in the IUGR group. These results were associated with lower (P<0·05) phosphorylated levels of the NF-κB pathway and Janus kinase 2 (JAK2) and higher (P<0·05) mRNA expression of genes involved in the nuclear factor, erythroid 2-like 2 (Nfe2l2)/antioxidant response element (ARE) pathway in the liver of the IC rats than that of the IUGR rats. Maternal undernutrition decreased birth weight and led to inflammation, oxidative damage and injury in rats. Curcumin appeared to be beneficial in preventing IUGR-induced inflammation, oxidative damage and injury by activating the expression of the NF-κB, JAK/STAT and Nfe2l2/ARE pathways in the liver.
In this work, differential scanning calorimetry (DSC) was used to characterize and analyze the precipitation/dissolution kinetics of second phase particles during the cooling/reheating process in a vanadium microalloyed steel. The results indicated that three obvious exothermic peaks were detected on the cooling DSC curve. Furthermore, three corresponding endothermic peaks were also detected on the heating DSC curve. Combined with thermodynamic calculation and transmission electron microscopy analysis, these three exothermic peaks along cooling DSC curve were defined as the precipitation reaction of V(CN), the reaction of austenite transformation into ferrite and the precipitation reaction of VC, respectively. Meanwhile, three corresponding reverse reactions for cooling were also defined along the reheating DSC curve. The linear regression result revealed that the precipitation activation energies for V(CN) and VC were identified as 311.2 kJ/mol and 167.6 kJ/mol, respectively. The dissolution activation energies for VC and V(CN) were identified as 255.4 kJ/mol and 592.6 kJ/mol, respectively.
The experiments reported in this research communication aimed to plot the expression pattern of Sirt3, a master regulator of energy metabolism and antioxidation defence, in the liver of dairy goats during perinatal period. Ten healthy dairy goats in late pregnancy were chosen, and needle biopsy was applied to collect liver samples at 1-week intervals. Protein levels of hepatic Sirt3 were analysed by western-blotting. Serum enzyme activities of manganese superoxide dismutase (Mn-SOD) and non-esterified fatty acids (NEFA) levels were measured, and their correlation with Sirt3 mRNA levels was also estimated. Compared with >3-week before parturition (BP), Sirt3 proteins were significantly reduced at 1-week after parturition (AP) and 2-week AP (P < 0·05), but increased on the day of parturition (P < 0·01). Correlation analysis revealed a positive association between hepatic Sirt3 mRNA levels and serum enzyme activity of Mn-SOD (r = 0·46), but a negative association between that and serum NEFA levels (r = −0·41). These data indicate that the decreased hepatic expression of Sirt3 might be one of the reasons that dairy goats undergo oxidative stress after parturition.
This work was aimed to use the peak separation method to directly measure the critical temperatures and phase transition fractions of austenite decomposition products based on experimental dilatometric curves in hypo-eutectoid steels. The results indicated that pearlite transformation start temperature and ferrite transformation finish temperature could be clearly obtained through peak separation processing, which were generally hidden in the overlapped peaks of the linear thermal expansion coefficient curve. Moreover, four critical temperatures of austenite decomposition were retarded to lower temperature with cooling rate increasing. The phase transition fraction for austenite decomposition was quantitated by measuring the area of the corresponding phase transformation peak. The final ferrite phase fraction after austenite decomposition decreased with cooling rate increasing. On the contrary, the final pearlite phase fraction increased with cooling rate increasing. Compared with the lever rule, the calculation result using peak area method can accurately reflect the actual phase fraction change versus the temperature during austenite decomposition.
Change mode and effects analysis (CMEA) is a powerful technique for measuring product flexibility toward future changes and diminishing the cost of redesign as well as shortening time to market. As a systematic methodology, it provides an in-depth view for the investigation of potential changes, causes, and effects in designs, products, and processes. Traditional CMEA determines the risk priorities of change modes by using change potential number, which requires the risk factors of design flexibility, occurrence, and readiness to be precisely evaluated. However, this is not always possible in real applications due to the uncertainty and subjectivity involved in the early design stages. It has been criticized much for its deficiencies in criteria weighting of the risk factors, change potential number calculation, and risk priorities determination of the change modes. This paper presents a systematic evaluation approach for determining a more rational rank of change modes by combining with the entropy weight method, rough number, and grey relational analysis. In this study, the entropy weight method is adopted to calculate the relative importance of risk factors. Rough number is presented to aggregate individual weights and preferences, and to manipulate the vagueness in the evaluation process. Then a rough number enhanced grey relational analysis is proposed to evaluate the risk ranking of change modes. Finally, a practical example is put forward to validate the performance of the proposed method. The result shows that the proposed change mode evaluation method can effectively overcome the shortcomings of traditional CMEA and strengthen the objectivity of product flexibility measurement.
The prevalence of CHD has been well described worldwide except in Tibet. This study aimed to illustrate the prevalence and composition of CHD in Tibetan children according to altitude.
Methods and results
In the first part, we prospectively recruited 7088 unselected Tibetan children (4–17 years) from south-west Tibet. The total prevalence of CHD increased from 4.6/1000 below 4200 m to 13.4/1000 above 4700 m, with a female-to-male ratio of 1.3:3.1. The total prevalence and female prevalence of patent ductus arteriosus increased more than 10-fold. Females living above 4700 m had exceptionally high prevalence of patent ductus arteriosus (14.9/1000). The prevalence of atrial septal defect was comparable among different altitudes (3.3–3.8/1000). The prevalence of ventricular septal defect was 1.3/1000 below 4700 m, and no cases were found above this altitude. In the second part, we retrospectively reviewed the clinical data of 383 CHD children in Tibet and 73 children at lower altitudes. The percentage of isolated ventricular septal defect decreased from 54.8 to 3.1%, and the percentage of isolated patent ductus arteriosus increased from 8.2 to 68.4% with elevation. Children living below 4200 m (10.4–13.7%) had a larger proportion of complex CHD than those above this altitude (2.0–3.1%). Of the 20 Tibetan children with complex CHD, 14 (70.0%) lived below 4200 m.
Conclusions
A wide variation in CHD prevalence and composition existed in Tibetan children among different altitudes.
We analyze in this paper the pressure splitting scheme of a partitioned semi-implicit coupling algorithm for fluid-structure interaction (FSI) simulation. The semi-implicit coupling algorithm is developed on the ground of the artificial compressibility characteristic-based split (AC-CBS) scheme that serves not only for the fluid subsystem but also for the global FSI system. As the dual-time stepping procedure recommended for quasi-incompressible flows is incorporated into the implicit coupling stage, the fluctuating pressure may be unusually susceptible to the AC coefficient. Moreover, it is not trivial to devise an optimal AC formulation for pressure estimation. Instead, we consider a stabilized second-order pressure splitting scheme in the AC-CBS-based partitioned semi-implicit coupling algorithm. Computer simulation of a benchmark FSI experiment demonstrates that good agreement is exposed between the available and present data.
In this paper, numerical simulations of solid particle erosion phenomena on H-type finned circular/elliptic tube surface, which is of great significance to the antiwear design of heat exchanger, are presented. The Eulerian-Lagrangian approach is applied to simulate the dilute gas-solid flow through H-type finned circular/elliptic tubes. A semi-empirical model is adopted to predict the erosion rate. The dynamics behavior of the entrained solid particles in the flow is presented. The geometry of eroded tube surface is changed with the predicted erosion which is taken into account by a UDF and the flow field is re-solved for the eroded tube surface at every time step. The influences of ten parameters (the tube bundle arrangement, particle size, particle concentration, fluid Reynolds number, fin thickness, fin pitch, fin length, fin width, slit width and the transverse tube pitch) on the maximum erosion depth of the H-type circular/elliptic finned tube surface are investigated. Using H-type finned elliptic tube surface can effectively reduce the erosion rate of tube surface comparedwith that using H-type finned circular tube surface. The erosion in in-line arrangement is less severe than that in staggered arrangement. With the increase of particle size, particle concentration and the fluid Reynolds number, the erosion rate of the tube surface rises. The numerically predicted effect of Reynolds number is in good agreement with previous test data. Among the six geometry parameters, the most influential parameter is the transverse tube pitch.
As the basic conditions for laser inertial confinement fusion (ICF) research, the targets are required to be well specified and elaborately fabricated. Because of the characteristics of the targets, the research and fabrication process is a systematically tough task, which needs fundamental and deep insights into film deposition, mechanical machining, precise measurement and assembly, etc. As a result, knowledge of material science, physics, mechanical as well as electronics is a necessity for target researchers. In this paper, we give introductions to the state of art on target fabrication for ICF research at Research Center of Laser Fusion (RCLF) in China.
In this paper, field effect transistors (FET) based on different kinds of non-graphene materials are introduced, which are MoS2, WSe2 and black phosphorus (BP). Those devices have their unique features in fabrication process compared with conventional FETs. Among them, MoS2 FET shows better electrical characteristics by applying a SiO2 protective layer; WSe2 FET is fabricated based on a new low pressure chemical vapor deposition (LPCVD) method; BP FET acquires high on/off ratio and high hole mobility by using a simple dry transfer method. Those novel non-graphene materials inspire new design and fabrication process of basic logic device.