75 research outputs found

    Synergistic Effect of Nanosilica Aerogel with Phosphorus Flame Retardants on Improving Flame Retardancy and Leaching Resistance of Wood

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    Nanosilica (Nano-SiO2) sol fabricated by a sol-gel process was introduced into wood modification with phosphorus flame retardants to improve the flame retardancy and leaching resistance of wood. The obtained materials were characterized by scanning electron microscopy and energy dispersive spectrometer (SEM-EDS), thermogravimetric analysis (TGA), cone calorimetric (CONE), and infrared spectroscopy (FT-IR). The residual rate of flame retardants before and after leaching was determinated by a leaching resistance. The results showed that the phosphorus flame retardants and SiO2 sol could reside in the poplar wood and are widely distributed in the vessels, pits, wood timber, and the spaces between wood cells of poplar substrate. TGA and CONE results indicated that the introduction of nano-SiO2 aerogel with phosphorus flame retardants had a significantly synergistic effect on improving the flame retardancy and inhibiting the release of smoke and toxic gases. In addition, the leaching resistance test, combined with infrared analysis and EDS analysis, confirmed that the phosphorus flame retardants were able to be fixed by SiO2 aerogel in the wood

    Differential analysis of chromatin accessibility and histone modifications for predicting mouse developmental enhancers

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    Enhancers are distal cis-regulatory elements that modulate gene expression. They are depleted of nucleosomes and enriched in specific histone modifications; thus, calling DNase-seq and histone mark ChIP-seq peaks can predict enhancers. We evaluated nine peak-calling algorithms for predicting enhancers validated by transgenic mouse assays. DNase and H3K27ac peaks were consistently more predictive than H3K4me1/2/3 and H3K9ac peaks. DFilter and Hotspot2 were the best DNase peak callers, while HOMER, MUSIC, MACS2, DFilter and F-seq were the best H3K27ac peak callers. We observed that the differential DNase or H3K27ac signals between two distant tissues increased the area under the precision-recall curve (PR-AUC) of DNase peaks by 17.5-166.7% and that of H3K27ac peaks by 7.1-22.2%. We further improved this differential signal method using multiple contrast tissues. Evaluated using a blind test, the differential H3K27ac signal method substantially improved PR-AUC from 0.48 to 0.75 for predicting heart enhancers. We further validated our approach using postnatal retina and cerebral cortex enhancers identified by massively parallel reporter assays, and observed improvements for both tissues. In summary, we compared nine peak callers and devised a superior method for predicting tissue-specific mouse developmental enhancers by reranking the called peaks

    Acceptability and feasibility of smartphone-assisted 24 h recalls in the Chinese population

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    Abstract Objective To examine the acceptability and feasibility of using smartphone technology to assess beverage intake and evaluate whether the feasibility of smartphone use is greater among key sub-populations. Design An acceptability and feasibility study of recording the video dietary record, the acceptability of the ecological momentary assessment (EMA), wearing smartphones and whether the videos helped participants recall intake after a cross-over validation study. Setting Rural and urban area in Shanghai, China. Subjects Healthy adults ( n 110) aged 20ā€“40 years old. Results Most participants reported that the phone was acceptable in most aspects, including that videos were easy to use (70 %), helped with recalls (77 %), EMA reminders helped them record intake (75 %) and apps were easy to understand (85 %). However, 49 % of the participants reported that they had trouble remembering to take videos of the beverages before consumption or 46 % felt embarrassed taking videos in front of others. Moreover, 72 % reported that the EMA reminders affected their consumption. When assessing overall acceptability of using smartphones, 72 % of the participants were favourable responders. There were no statistically significant differences in overall acceptability for overweight v. normal-weight participants or for rural v. urban residents. However, we did find that the overall acceptability was higher for males (81 %) than females (61 %, P =0Ā·017). Conclusions Our study did not find smartphone technology helped with dietary assessments in a Chinese population. However, simpler approaches, such as using photographs instead of videos, may be more feasible for enhancing 24 h dietary recalls

    Serine palmitoyltransferase and ceramide kinase in embryo development of loblolly pine

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    Using the known sequences for serine palmitoyltransferase (SPT) and ceramide kinase (CERK) from Arabidopsis, candidates for the corresponding genes in Loblolly pine were cloned and examined during embryogenesis. The cloned two cDNA sequences from Loblolly pine, which has similarity of 81% and 88% respectively to two subunits of SPT1 and SPT2 in Arabidopsis, were presumed as the Loblolly pine SPT1 and SPT2 (Pt-SPT1 and Pt-SPT2). A few different versions of Pt-SPT1 mRNAs (2223 nts, 756 nts, 822 nts, and 754 nts respectively), most likely the alternative splicing results, were found. Three of these mRNAs are capable of encoding proteins. The long version (2223 nts) encodes a protein with 484 amino acids (Pt-SPT1); two short versions (822 nts, 756 nts) encode a 90 a.a. protein. Another cDNA sequence of 2396 nts encodes a protein of 493 a.a. (Pt-SPT2). Both predicted Pt-SPT1 and Pt-SPT2 proteins possess highly conserved serine palmitoyltransferase functional domains (E value 5.7e-61). Their expression patterns are different between somatic and zygotic embryogenesis. Two different versions of mRNAs, with 2786 nts (long), and 2320 nts (short) respectively, of ceramide kinases in Loblolly pine (Pt-CERKs) have been cloned. The long version encodes a protein with 721 a.a.; the short version with 560 a.a. The expression patterns for these two CERK mRNAs are different during embryo development. The long version is constitutively expressed, while the short one is only expressed in some stages with much lower expression level. Overexpression Pt-CERKL, Pt-CERKS, and Pt-CERKF in E.coli and function analysis in vitro show that all Pt-CERKs appear to have the same catalytic functions as their homologs in human and Arabidopsis, but with different efficiency. The catalytic efficiency was dramatically lower in the short Pt-CERK protein compared with the long Pt-CERK protein and Pt-CERKF. The membrane system is not necessary for the catalytic reactions of these three Pt-CERKs in vitro and Pt-CERKs were less dependent on the Ca2+ ions. Thus, these studies have provided the first information about SPT- and CERK- like proteins in loblolly pine, and open new avenues of investigation for the roles of sphingolipids in embryonic development.Ph.D.Committee Chair: Cairney, John; Committee Member: Merrill, Alfred Jr.; Committee Member: Nichols, Wylie; Committee Member: Pullman, Jerry; Committee Member: Streelman,Tod

    Control Materials of Hydrogen Concentration in Micro Environment and Their Summary of Application

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    Some materials will be hydrogenated to corrosion, such as metal materials, organic materials, polymer materials and so on, when the concentration of hydrogen in a mixed gas is greater than 4% in a closed space of micro environment. Their performances will be seriously affected. So removing or reducing the concentration of hydrogen in a micro environment can fundamentally solve the problem of hydrogenation corrosion. Metallic hydrogen removing agent and organic hydrogen removing agent are the main research directions of controlling materials of hydrogen concentration in micro environment. Current research status in the world are comprehensively reviewed from these two aspects. Features and application scopes of these two kinds of materials are pointed out separately, which provide a theoretical reference for the prevention of accidents caused by hydrogenation corrosion

    Control Materials of Hydrogen Concentration in Micro Environment and Their Summary of Application

    No full text
    Some materials will be hydrogenated to corrosion, such as metal materials, organic materials, polymer materials and so on, when the concentration of hydrogen in a mixed gas is greater than 4% in a closed space of micro environment. Their performances will be seriously affected. So removing or reducing the concentration of hydrogen in a micro environment can fundamentally solve the problem of hydrogenation corrosion. Metallic hydrogen removing agent and organic hydrogen removing agent are the main research directions of controlling materials of hydrogen concentration in micro environment. Current research status in the world are comprehensively reviewed from these two aspects. Features and application scopes of these two kinds of materials are pointed out separately, which provide a theoretical reference for the prevention of accidents caused by hydrogenation corrosion

    Effect of Cellulose Nanocrystal Addition on the Physicochemical Properties of Hydroxypropyl Guar-Based Intelligent Films

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    As an important functional material in food industry, intelligent packaging films can bring great convenience for consumers in the field of food preservation and freshness detection. Herein, we fabricated pH-sensing films employing hydroxypropyl guar (HPG), 1-butyl-3-methylimidazolium chloride (BmimCl), and anthocyanin (Anth). Besides, the effects of adding cellulose nanocrystals (CNC) into the composite films upon the filmsā€™ structures and physicochemical properties are elucidated. The addition of CNC promoted more compact film structures. Moreover, CNC dramatically improved several properties of the pH-sensing films, including the distinguishability of their color changes, sensitivity to pH, permeability to oxygen and water vapor, solvent resistance, durability, and low-temperature resistance. These results expand the application range of pH-sensing films containing CNC in the fields of food freshness detection and intelligent packaging
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