10 research outputs found

    Ultrahigh Performance Liquid Chromatography Analysis of Volatile Carbonyl Compounds in Virgin Olive Oils

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    The enzymatic and chemical oxidation reaction in olive oil produces many volatile carbonyl compounds that contribute to the complex flavor of olive oil. A novel ultrahigh performance liquid chromatography (UHPLC) method with dynamic headspace sampling and 2,4-dinitrophenylhydrazine (DNPH) derivatization were established to determine the volatile carbonyls in virgin olive oil. Quantification of nine characteristic carbonyls (acetone, hexanal, <i>E</i>-2-hexenal, octanal, <i>E</i>-2-octenal, nonanal, <i>E</i>-2-nonenal, <i>E</i>,<i>E</i>-2,4-nonadienal, and <i>E</i>,<i>E</i>-2,4-decadienal) was achieved using cyclopentanal as an internal standard. This method provides comparable linearity (<i>R</i><sup>2</sup> = 0.9917–1.0000) and repeatability (less than 7.6% relative standard deviations) with solid phase microextraction gas chromatography (SPME-GC). The relative standard deviations (%RSD) of all applied carbonyl standards were lower than 7.6%. The limits of detection (LOD) and quantification (LOQ) were in the ranges of 1.6–150.1 and 4.8–906.1 μg/kg. The recoveries obtained for olive oil samples were in the range of 81.0–115.3%. To show the potential of this method on the quantification of other volatile carbonyls that were not included in this study, GC–electron ionization mass spectrometry (GC–EI/MS) was employed to identify the derivatized carbonyls (carbonyl (2,4-DNPH) hydrazones) while peak assignments were made on the basis of elution sequences and peak areas. This method provided feasibility of using LC to determine volatile carbonyls in oil matrices, which can be applied to exam the degree of lipid oxidation and evaluate the sensory properties of VOO and other edible oils

    Association Study to Evaluate FoxO1 and FoxO3 Gene in CHD in Han Chinese

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    <div><p>Background</p><p>Coronary heart disease (CHD) is one of the leading causes of mortality and morbidity in China. Genetic factors that predispose individuals to CHD are unclear. In the present study, we aimed to determine whether the variation of FoxOs, a novel genetic factor associated with longevity, was associated with CHD in Han Chinese populations.</p><p>Methods</p><p>1271 CHD patients and 1287 age-and sex-matched controls from Beijing and Harbin were included. We selected four tagging single nucleotide polymorphisms (SNPs) of FoxO1 (rs2755209, rs2721072, rs4325427 and rs17592371) and two tagging SNPs of FoxO3 (rs768023 and rs1268165). And the genotypes of these SNPs were determined in both CHD patients and non-CHD controls.</p><p>Results</p><p>For population from Beijing, four SNPs of FoxO1 and two SNPs of FoxO3 were found not to be associated with CHD (p>0.05). And this was validated in the other population from Harbin (p>0.05). After combining the two geographically isolated case-control populations, the results showed that the six SNPs did not necessarily predispose to CHD in Han Chinese(p>0.05). In stratified analysis according to gender, the history of smoking, hypertension, diabetes mellitus, hyperlipidemia and the metabolic syndrome, we further explored that neither the variants of FoxO1 nor the variants of FoxO3 might be associated with CHD (p>0.05).</p><p>Conclusion</p><p>The variants of FoxO1 and FoxO3 may not increase the prevalence of CHD in Han Chinese population.</p></div

    Characteristics of populations.

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    <p>The data were presented as mean±SEM (standard error of the mean) for age and BMI as well as No.(percentage) for other factors. P values for age and BMI were calculated from t-test comparing case and control groups within population. P values for gender, smoking, hypertension, diabetes mellitus, hyperlipidemia, metabolic syndrome were calculated from Chi-square test within population. BMI: body mass index.</p

    Frequency of FoxO1 and FoxO3 polymorphism in CHD from two different populations.

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    <p>Calculations are performed with comparison of three different genotypes. Values are the number of subjects. No significant difference (chi-square test) was found in the frequency of either polymorphism between CHD cases and non-CHD controls.</p

    Workflow to construct the MI-specific miRNA and TF mediated regulatory network.

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    <p>Step 1: Collecting MIgenes, MImiRNAs and known human TFs from publicly available databases and literature. Step 2: Retrieving regulatory relationships among MIgenes, MImiRNAs and known human TFs using an integrated strategy. Step 3: Identifying three types of FFLs based on the relationships among MIgenes, MImiRNAs and known human TFs. Step 4: Constructing the MI-specific miRNA and TF mediated regulatory network by merging the FFLs obtained in step 3.</p

    MicroRNA and Transcription Factor Mediated Regulatory Network Analysis Reveals Critical Regulators and Regulatory Modules in Myocardial Infarction

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    <div><p>Myocardial infarction (MI) is a severe coronary artery disease and a leading cause of mortality and morbidity worldwide. However, the molecular mechanisms of MI have yet to be fully elucidated. In this study, we compiled MI-related genes, MI-related microRNAs (miRNAs) and known human transcription factors (TFs), and we then identified 1,232 feed-forward loops (FFLs) among these miRNAs, TFs and their co-regulated target genes through integrating target prediction. By merging these FFLs, the first miRNA and TF mediated regulatory network for MI was constructed, from which four regulators (SP1, ESR1, miR-21-5p and miR-155-5p) and three regulatory modules that might play crucial roles in MI were then identified. Furthermore, based on the miRNA and TF mediated regulatory network and literature survey, we proposed a pathway model for miR-21-5p, the miR-29 family and SP1 to demonstrate their potential co-regulatory mechanisms in cardiac fibrosis, apoptosis and angiogenesis. The majority of the regulatory relations in the model were confirmed by previous studies, which demonstrated the reliability and validity of this miRNA and TF mediated regulatory network. Our study will aid in deciphering the complex regulatory mechanisms involved in MI and provide putative therapeutic targets for MI.</p></div

    Three modules in the MI-specific miRNA and TF mediated network.

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    <p>The nodes in the orange box denote hub nodes, and the nodes in the purple box denote having a top 5% betweenness centrality in the network.</p

    Model of co-regulation of miR-21-5p, the miR-29 family and SP1 involving a biological pathway and the regulatory network.

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    <p>After MI, the expression of TNF-α, IL-6 and TGF-β increased and activated several biological pathways, including JAK and PI3K/AKT pathways. These signal transductions activated several TFs, such as NFκB, STAT3 and SP1, to promote the transcription of miRNAs (e.g. mir-21) and genes (e.g. <i>TIMP3</i>, <i>VEGFA</i>, <i>FASLG</i> and <i>COL4A1</i>). miR-21-5p, the miR-29 family and SP1 co-regulated the process of cardiac fibrosis, apoptosis and angiogenesis through several cascades.</p

    An Effective Approach for Alleviating Cation-Induced Backbone Degradation in Aromatic Ether-Based Alkaline Polymer Electrolytes

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    Aromatic ether-based alkaline polymer electrolytes (APEs) are one of the most popular types of APEs being used in fuel cells. However, recent studies have demonstrated that upon being grafted by proximal cations some polar groups in the backbone of such APEs can be attacked by OH<sup>–</sup>, leading to backbone degradation in an alkaline environment. To resolve this issue, we performed a systematic study on six APEs. We first replaced the polysulfone (PS) backbone with polyphenylsulfone (PPSU) and polyphenylether (PPO), whose molecular structures contain fewer polar groups. Although improved stability was seen after this change, cation-induced degradation was still obvious. Thus, our second move was to replace the ordinary quaternary ammonia (QA) cation, which had been closely attached to the polymer backbone, with a pendant-type QA (pQA), which was linked to the backbone through a long side chain. After a stability test in a 1 mol/L KOH solution at 80 °C for 30 days, all pQA-type APEs (pQAPS, pQAPPSU, and pQAPPO) exhibited as low as 8 wt % weight loss, which is close to the level of the bare backbone (5 wt %) and remarkably lower than those of the QA-type APEs (QAPS, QAPPSU, and QAPPO), whose weight losses under the same conditions were >30%. The pQA-type APEs also possessed clear microphase segregation morphology, which led to ionic conductivities that were higher, and water uptakes and degrees of membrane swelling that were lower, than those of the QA-type APEs. These observations unambiguously indicate that designing pendant-type cations is an effective approach to increasing the chemical stability of aromatic ether-based APEs
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