6,162 research outputs found

    Evaluation of the association between maternal folic acid supplementation and the risk of congenital heart disease : a systematic review and meta-analysis

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    Background: Folic acid (FA), as a synthetic form of folate, has been widely used for dietary supplementation in pregnant women. The preventive effect of FA supplementation on the occurrence and recurrence of fetal neural tube defects (NTD) has been confirmed. Incidence of congenital heart diseases (CHD), however, has been parallelly increasing worldwide. The present study aimed to evaluate whether FA supplementation is associated with a decreased risk of CHD. Methods: We searched the literature using PubMed, Web of Science and Google Scholar, for the peer-reviewed studies which reported CHD and FA and followed with a meta-analysis. The study-specific relative risks were used as summary statistics for the association between maternal FA supplementation and CHD risk. Cochran's Q and I2 statistics were used to test for the heterogeneity. Results: Maternal FA supplementation was found to be associated with a decreased risk of CHD (OR = 0.82, 95% CI: 0.72–0.94). However, the heterogeneity of the association was high (P < 0.001, I2 = 92.7%). FA supplementation within 1 month before and after pregnancy correlated positively with CHD (OR 1.10, 95%CI 0.99–1.23), and high-dose FA intake is positively associated with atrial septal defect (OR 1.23, 95%CI 0.64–2.34). Pregnant women with irrational FA use may be at increased risk for CHD. Conclusions: Data from the present study indicate that the heterogeneity of the association between maternal FA supplementation and CHD is high and suggest that the real relationship between maternal FA supplementation and CHD may need to be further investigated with well-designed clinical studies and biological experiments

    Classification of Gapped Symmetric Phases in 1D Spin Systems

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    Quantum many-body systems divide into a variety of phases with very different physical properties. The question of what kind of phases exist and how to identify them seems hard especially for strongly interacting systems. Here we make an attempt to answer this question for gapped interacting quantum spin systems whose ground states are short-range correlated. Based on the local unitary equivalence relation between short-range correlated states in the same phase, we classify possible quantum phases for 1D matrix product states, which represent well the class of 1D gapped ground states. We find that in the absence of any symmetry all states are equivalent to trivial product states, which means that there is no topological order in 1D. However, if certain symmetry is required, many phases exist with different symmetry protected topological orders. The symmetric local unitary equivalence relation also allows us to obtain some simple results for quantum phases in higher dimensions when some symmetries are present.Comment: 21 pages, 7 figures. Version 2, classification for parity and translation symmetry update

    A novel multi-objective evolutionary algorithm based on space partitioning

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    To design an e ective multi-objective optimization evolutionary algorithms (MOEA), we need to address the following issues: 1) the sensitivity to the shape of true Pareto front (PF) on decomposition-based MOEAs; 2) the loss of diversity due to paying so much attention to the convergence on domination-based MOEAs; 3) the curse of dimensionality for many-objective optimization problems on grid-based MOEAs. This paper proposes an MOEA based on space partitioning (MOEA-SP) to address the above issues. In MOEA-SP, subspaces, partitioned by a k-dimensional tree (kd-tree), are sorted according to a bi-indicator criterion de ned in this paper. Subspace-oriented and Max-Min selection methods are introduced to increase selection pressure and maintain diversity, respectively. Experimental studies show that MOEA-SP outperforms several compared algorithms on a set of benchmarks

    Induction of colonic epithelial cell apoptosis by p47-dependent oxidants11Nucleotide sequence data reported are available in GenBank database under accession # AF540955.

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    AbstractExogenous oxidants appear capable of initiating both proliferative and death signals, but the role of endogenous oxidants in either tumorigenesis or tumor suppression is unclear. We found that expression of the NAD(P)H oxidase adapter p47phox was suppressed in human colon carcinoma specimens relative to adjacent normal colon. Overexpression of p47phox increased apoptosis in colon cancer cell lines independent of p53 and mismatch-repair competency. p47phox was found to interact with the c-Abl adapter Abl interactor-1 (ABI-1), and p47phox coprecipitated with both ABI-1 and c-Abl. Ectopic expression of p47phox in colon cancer cells increased oxidant production with phosphorylation and activation of nuclear c-Abl and consequent apoptosis. Colonic epithelial p47phox may be specifically targeted to a c-Abl-containing complex that serves a physiologic tumor suppressing function

    The entanglement in one-dimensional random XY spin chain with Dzyaloshinskii-Moriya interaction

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    The impurities of exchange couplings, external magnetic fields and Dzyaloshinskii--Moriya (DM) interaction considered as Gaussian distribution, the entanglement in one-dimensional random XYXY spin systems is investigated by the method of solving the different spin-spin correlation functions and the average magnetization per spin. The entanglement dynamics at central locations of ferromagnetic and antiferromagnetic chains have been studied by varying the three impurities and the strength of DM interaction. (i) For ferromagnetic spin chain, the weak DM interaction can improve the amount of entanglement to a large value, and the impurities have the opposite effect on the entanglement below and above critical DM interaction. (ii) For antiferromagnetic spin chain, DM interaction can enhance the entanglement to a steady value. Our results imply that DM interaction strength, the impurity and exchange couplings (or magnetic field) play competing roles in enhancing quantum entanglement.Comment: 12 pages, 3 figure

    Measuring Invisible Particle Masses Using a Single Short Decay Chain

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    We consider the mass measurement at hadron colliders for a decay chain of two steps, which ends with a missing particle. Such a topology appears as a subprocess of signal events of many new physics models which contain a dark matter candidate. From the two visible particles coming from the decay chain, only one invariant mass combination can be formed and hence it is na\"ively expected that the masses of the three invisible particles in the decay chain cannot be determined from a single end point of the invariant mass distribution. We show that the event distribution in the log(E1T/E2T)\log(E_{1T}/E_{2T}) vs. invariant mass-squared plane, where E1TE_{1T}, E2TE_{2T} are the transverse energies of the two visible particles, contains the information of all three invisible particle masses and allows them to be extracted individually. The experimental smearing and combinatorial issues pose challenges to the mass measurements. However, in many cases the three invisible particle masses in the decay chain can be determined with reasonable accuracies.Comment: 45 pages, 32 figure

    Effects of ac-field amplitude on the dielectric susceptibility of relaxors

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    The thermally activated flips of the local spontaneous polarization in relaxors were simulated to investigate the effects of the applied-ac-field amplitude on the dielectric susceptibility. It was observed that the susceptibility increases with increasing the amplitude at low temperatures. At high temperatures, the susceptibility experiences a plateau and then drops. The maximum in the temperature dependence of susceptibility shifts to lower temperatures when the amplitude increases. A similarity was found between the effects of the amplitude and frequency on the susceptibility.Comment: 8 pages, 7 figures, Phys. Rev. B (in July 1st

    NHERF1 suppresses lung cancer cell migration by regulation of epithelial-mesenchymal transition

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    Background/Aim: Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) has been reported to interact with many cancer-related proteins and plays an important role in cancer progression. However, little is known about the biological functions of NHERF1 in lung cancer cells. The aim of the current study was to explore whether NHERF1 is involved in transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in non-small-cell lung cancer cells. Materials and Methods: The expression of NHERF1 and EMT-associated markers including E-cadherin, N-cadherin, snail family transcriptional repressor 1 (SNAI1) and snail family transcriptional repressor 2 (SLUG) were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and western blotting. The migratory properties of cells were assessed using a wound-healing assay. Results: TGF-β1-induced a pro-migratory response in the A549 lung cancer cell line, that was consistently associated with corresponding changes in the expression levels of EMT-related genes. The expression of NHERF1 significantly decreased in the TGF-β1-induced A549 cells. Overexpression of NHERF1 significantly inhibited the migratory ability of cells and reversed the TGF-β1-induced mesenchymal phenotype of A549 cells. Conclusion: These data showed an important role of NHERF1 in the EMT of non-small-cell lung cancer cells, as well as migration
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