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Effects of microwave pretreatment on oxidation of pressed rapeseed oil during accelerated storage

Oil Crop Science 2017年第3期2卷 169-180页

作者： Qi Zhou Chang Zheng Chuyun Wan Pingmei Guo Wenlin Li Changsheng Liu Fenghong Huang Key Laboratory of Biology and Genetic Improvement of Oil Crops Ministry of Agriculture Oil Crops Research InstituteChinese Academy of Agricultural Sciences Wuhan China Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory Key Laboratory of Oilseeds Processing Ministry of Agriculture Hubei Key Laboratory of Lipid Chemistry and Nutrition Wuhan China

To investigate advantages of microwave pretreatment for oil storage, oxidative stability of pressed rapeseed oil with microwave pretreatment (M-RO) was evaluated, while pressed rapeseed oil (RO) and RO with 200 ppm tertiary butylhydroquinone added (T-RO) were used for comparison. Oil samples were collected after accelerated storage at 60oC in dark for 0-32 d. A total of 37 oxidized volatile compounds were identified and 9 typical key compounds were quantified by solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS). Correlation analysis showed that lipid oxidation parameters and induction time (IP) had significant association with typical indicators of volatile oxidized compounds. Hexanal and (E,E)-2,4-heptadienal were most suitable for differentiating RO sample at different storage times while 1-hexanol, 1-heptanal and (E)-2-octenal were suitable for T-RO sample. To M-RO sample, 5 substances described above together can provide a guide for monitoring lipid oxidation. M-RO has better oxidation resistance than RO, with advantage of 4 d in accelerated conditions both in sensory evaluation and PCA analysis. However, it still produces more volatile oxidized compounds and has higher peroxide value (PV) and p-anisidine value (p-AV) than T-RO sample at any sampling point. Anti-oxidation efficiency of rapeseed oil can be promoted via microwave pretreatment. This work provid new clues of benefits about microwave pretreatment in oil storage.

关键词： rapeseed oil microwave pretreatment synthetic antioxidant volatile oxidative compounds accelerated storage

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PPG Launches Environmentally-Responsible Zircobond pretreatment

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China Chemical Reporter 2009年第Z1期20卷 15-15页

PPG Industries announced on February 6th, 2009 the launch of its new, environmentally-responsible Zircobond (TM ) pretreatment *** pretreatment is a well-established method of providing cleanliness and

关键词： pretreatment providing launch manganese

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Heat shock pretreatment enhances porcine myoblasts survival after autotransplantation in intact skeletal muscle

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Science China(Life Sciences) 2007年第4期50卷 438-446页

作者： YANG Sheng1,2, Thomas LAUMONIER2 & Jacques MENETREY2 1 Department of Orthopedic Surgery, Affiliated Zhongshan Hospital of Dalian University, Dalian 116001, China 2 Department of Orthopedic Surgery, Geneva Faculty of Medicine and Universtiy Hospital, CH-1211 Geneva, Switzerland Department of Orthopedic Surgery Affiliated Zhongshan Hospital of Dalian University Dalian 116001 China Department of Orthopedic Surgery Geneva Faculty of Medicine and Universtiy Hospital CH-1211 Geneva Switzerland Department of Orthopedic Surgery Geneva Faculty of Medicine and Universtiy Hospital CH-1211 Geneva Switzerland

Myoblast transplantation (MT) is a cell-based gene therapy treatment, representing a potential treat-ment for Duchenne muscular dystrophy (DMD), cardiac failure and muscle trauma. The rapid and mas-sive death of transplanted cells after MT is considered as a major hurdle which limits the efficacy of MT treatment. Heat shock proteins (HSPs) are overexpressed when cells undergo various insults. HSPs have been described to protect cells in vivo and in vitro against diverse insults. The aim of our study is to investigate whether HSP overexpression could increase myoblast survival after autotransplantation in pig intact skeletal muscle. HSP expression was induced by warming the cells at 42℃ for 1 h. HSP70 expression was quantified by Western blot and flow cytometry 24 h after the treatment. To investigate the myogenic characteristics of myoblasts, desmin and CD56 were analysed by Western blot and flow cytometry; and the fusion index was measured. We also quantified cell survival after autologous transplantation in pig intact skeletal muscle and followed cell integration. Results showed that heat shock treatment of myoblasts induced a significative overexpression of the HSP70 (P 0.05). However, the myoblast survival rate in the heat shocked cells increased by twofold at 48 h (53.32% ± 8.22% versus 28.27% ± 6.32%, P pretreatment increased the HSP70 expression in porcine myoblasts, and improved the survival rate after autologous transplantation. Therefore, heat s

关键词： myoblast heat shock pretreatment transplantation skeletal muscle HSP70

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Liquid-liquid extraction pretreatment samples method used for pharmacokinetic study of rhubarb in rats after oral administrated

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Journal of Traditional Chinese Medical Sciences 2018年第3期5卷 291-301页

作者： Hongmei Lin Longfei Lin Lingyan Xu Yuanping Xie Zhenzhen Xia Qing Wu Department of TCM Pharmaceutics School of Chinese Materia MedicaBeijing University of Chinese MedicineBeijingChina Institute of Chinese Materia Medica China Academy of Chinese Medical SciencesBeijingChina

Objective:pretreatment of biological samples is the most critical step in pharmacokinetic studies,especially pre-treatment of plasma *** pretreatment of biological samples in pharmacokinetic study of Traditional Chinese Medicines (TCM) is difficult due to the complexity of the *** organic solvent system ethyl acetate:acetone (10:1) solution used for liquid-liquid extraction has been developed in this study and compared with the commonly used protein precipitation ***:Rats,Beagle dogs and humans plasma samples were adopted in this study in order to demonstrate the universality of the pretreatment *** of this pretreatment method was also verified through its application to the pharmacokinetics of rhubarb in ***:According to the results of extraction recovery matrix effect,it was indicated that the liquid-liquid extraction methods with new organic solvent might be suitable for variety of structures of compounds and various types of plasma *** pharmacokinetic study result showed that the developed pretreatment method could successfully be used for simultaneous determination of three active compounds modin,emodin-8-O-β-D-glucopyranoside (EDG) and rhein in rat plasma with high sensitivity,accuracy,and recovery by liquid chromatography tandem mass spectrometry (LC-MS/MS).Conclusion:The pretreatment method of liquid-liquid extraction methods with new organic solvent could be successfully applied for multi-component pharmacokinetics of TCM.

关键词： pretreatment method Liquid-liquid extraction Protein precipitation LC-MS/MS Rhubarb

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Influence of Chemical pretreatment on the Dissolved Organics in Poplar Alkaline Peroxide Mechanical Pulping Effluent

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Paper And Biomaterials 2017年第1期2卷 32-39页

作者： XinYu Wang JiaChuan Chen HongLei Chen Lucian A.Lucia GuiHua Yang QinWu Key Laboratory of Beibu Gulf Environment Change and Resources Utilization Guangxi Teachers Education University Key Laboratory of Pulp & Paper Science and Technology of the Ministry of Education Qilu University of Technology Laboratory of Soft Materials & Green Chemistry Departments of Forest Biomaterials and ChemistryNorth Carolina State University

The components of the effluent from the chemical pretreatment of poplar alkaline peroxide mechanical pulp(APMP) were analyzed in this study. The main dissolved organics were low-molecular weight(LMW) lignin, oligosaccharides, and monosaccharides. The lignin and sugar concentrations in the effluent obtained using different chemical pretreatment conditions and chemical dosages were analyzed using ultraviolet(UV) spectroscopy. This analysis provided a theoretical basis for the subsequent treatment and utilization of APMP effluent. The experimental results showed that the dosages of Na OH, H_2O_2, and Na_2 SiO_3 in the chemical pretreatment process affected the lignin and sugar concentrations in the effluent and that different chemicals had differing degrees of influence. The degree of influence exhibited the following order: Na OH>H_2O_2>Na_2SiO_3. More specifically, the dosages of Na OH and H_2O_2 had stronger influences on the lignin and sugar concentrations than that of Na_2 SiO_3. Indeed, the Na_2 SiO_3 dosage hardly affected the lignin and sugar concentrations in the effluent, but Na_2 SiO_3 could stabilize the chemical pretreatment system and improve the reactive efficiency of Na OH and H_2O_2. The pretreatment temperature and time also affected the organic components, and the influence of the temperature was stronger than that of time.

关键词： poplar APMP effluent pretreatment lignin oligosaccharides

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Nanofibrillation of a Bleached Acacia Pulp by Grinding with Carboxymethylation pretreatment

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Paper And Biomaterials 2018年第3期3卷 32-38页

作者： Ming He GuiHua Yang JiaChuan Chen FanGong Kong Qiang Wang State Key Laboratory of Biobased Material and Green Papermaking/Key Lab of Pulp & Paper Science and Technology of Education Ministry of China Qilu University of Technology (Shandong Academy of Sciences)

In this study,carboxymethylation,which introduces carboxyl groups to hydroxyl sites in pulp fibers,was used as a pretreatment before mechanical *** carboxyl group content of the pulp fibers was greatly affected by the dosage of chloroacetic acid and the reaction *** the following fibrillation process,it was found that pulp fibers with higher carboxyl group content exhibited higher water holding capacities and smaller dimensions.A more homogenous structure with a higher amount of individual fibrils was also observed in FE-SEM images of pulp fibers with high carboxyl group *** can be explained by a high ionic group content in the fiber wall resulting in lower delamination resistance,making the fibrils easier to *** pretreatment as a facilitator of fibrillation in cellulosic pulps is an efficient way to obtain cellulose nanofibrils and consequently decrease the energy consumption of the process.

关键词： nanofibrillation grinder carboxymethylation pretreatment bleached acacia pulp

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Effect of Hot Dip Galvanized Steel Surface Chemistry and Morphology on Titanium Hexafluoride pretreatment

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Advances in Materials Physics and Chemistry 2017年第2期7卷 28-41页

作者： Ville Saarimaa Antti Markkula Kai Arstila Jere Manni Jyrki Juhanoja Top Analytica Oy Turku Finland SSAB Europe Oy H&auml meenlinna Finland Department of Physics University of Jyv&auml skylä Jyv&auml skylä Finland

Titanium hexafluoride pretreatments are known to improve paint adhesion and function as a barrier between the coating and the hot dip galvanized (HDG) steel surface. Interactions at the zinc/pretreatment interface are of utmost importance for the formation of pretreatment layers and the corrosion resistance of color coated hot dip galvanized steels. Removal rate of inert aluminum oxide from HDG steel samples by chemical dissolution was studied. XPS measurements showed that the surface Al2O3 layer thickness decreased rapidly already at mild alkaline cleaning, while complete removal of Al required severe etching. Low reactivity of an Al2O3-rich surface was confirmed by impaired formation of a titanium hexafluoride pretreatment layer. Grain boundaries and deformation twinnings were shown to be of importance for the reactivity of the HDG surface and for the precipitation of the pretreatment chemical. Helium ion microscopy images and electron probe microanalysis (EPMA) of a pretreated sample showed accumulation of the pretreatment chemical at the grain boundaries. Al removal rate was fast at the deformation twinnings at the grain plateaus. Slow Al removal was observed at dendritic valleys and grain boundaries. The results increase understanding of the reactivity of hot dip galvanized steel surface.

关键词： Hot Dip Galvanized Steel Aluminum Oxide pretreatment Surface Morphology Helium Ion Microscopy

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Hydrothermal pretreatment of Lignocellulosic Biomass and Kinetics

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Journal of Sustainable Bioenergy Systems 2013年第4期3卷 250-259页

作者： Hanwu Lei Iwona Cybulska James Julson Bioproducts Sciences and Engineering Laboratory Department of Biological Systems Engineering Washington State University Richland USA Department of Agricultural and Biosystems Engineering South Dakota State University Brookings USA

The study focus was an examination of the hydrothermal pretreatment method applied to the lignocellulosic substrate, represented by the prairie cord grass, and comparison between different conditions based on the yield of glucose after enzymatic hydrolysis. The treatment did not involve any chemicals usage. Enzymatic hydrolysis was performed in order to examine the amount of glucose which was released from pretreated materials. The most efficient pretreatment conditions were at high temperature and relatively short reaction time (210°C and 10 min), after which the lignocellulose structure was the most available for enzymes actions which resulted in a pretreatment conversion rate of 97%. Temperature had a significant influence on glucose release during the hydrolysis, which was confirmed by the Michaelis-Menten and kinetic models. Kinetic models were used to fit the inhibitors and their conversion rates were related to temperature.

关键词： Hydrothermal pretreatment Prairie Cord Grass Enzymatic Hydrolysis Kinetics

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Rapid Determination of Residual Quinolones in Honey Samples by Fast HPLC with an On-Line Sample pretreatment System

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American Journal of Analytical Chemistry 2011年第2期2卷 200-205页

作者： Wei Du JianGuo Yao YueQi Li Yuki Hashi Shimadzu Corporation Kyoto Japan Shimadzu International Trading (Shanghai) Co. Limited Beijing China

A method of on-line pretreatment coupled to HPLC with fluorescence detection was developed and validated for the determination of nine quinolones in honey samples. This method simplified the complicated process of sample pretreatment and reduced sample treatment time. Recovery of the quinolones was between 92% - 101% for spiked honey samples. The limit of detection was 0.22 - 3.78 ng/mL (signal/noise ratio = 3). There was good linear correlation between HPLC peak area and concentration of the quinolones, with a linear range of 1.0 - 100.0 ng/mL and correlation coefficients >0.9997. The method proposed was validated for detecting quinolones in honey samples.

关键词： Antibiotics High Performance Liquid Chromatography (HPLC) Honey On-Line pretreatment Quinolones

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Phosphoric Acid-assisted pretreatment Strategy for the Rational Synthesis of Lignin-derived Hierarchical Porous Carbon Toward High-performance Supercapacitors

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Paper And Biomaterials 2020年第1期5卷 43-53页

作者： Xiuwen Mei Jia Liu Feng Peng Runcang Sun Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing100083China Center for Lignocellulose Science and Engineering Liaoning Key Laboratory Pulp and Paper EngineeringDalian Polytechnic UniversityDalianLiaoning Province116034China

In this article, a facile two-step activation method, coupled with phosphoric acid(H3PO4)-assisted pretreatment and followed KOH activation,was reported for constructing hierarchical porous carbon(HPC) materials derived from lignin. The introduction of H3PO4, cross-linked with lignin sources generated phosphate(and/or polyphosphate) ester groups throughout the lignin structure, which endowed the pre-activated intermediate char(IC)with a hierarchical porous structure. Such phosphate esters contributed to the multi-scale pore structure within the pre-activated IC, which was beneficial for the uniform distribution and impregnation of subsequent KOH activators,thus leading to the formation of HPC materials. The as-prepared HPC exhibited a large specific surface area(SSA) of 1345.1 m^2/g, which ensures the accessibility of the ion diffusion pathways. The supercapacitors integrated with HPC delivered a high specific capacitance of 241 F/g(in a threeelectrode system) and outstanding rate capability with an 80.9% capacitance retention from 0.5 A/g to an ultra-high current density of 50 A/g.

关键词： lignin phosphoric acid-assisted pretreatment two-step activation hierarchical porous carbon supercapacitors electrochemical performance

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