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Cyclodextrin-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplets coupled with HPLC for the determination of pyrethroid residues in cereals

Jiang Haijuan, Bi Xinyuan, Huang Xin, Guo Xingle, Zou Ziyu, Li Ying, Jing Xu, Wu Junxue

Acta Chromatographica

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2023

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Vol. 35, no. 1

21--27

EN

A simple, rapid, and environmentally friendly sample preparation method for pyrethroids determination in cereals using cyclodextrin-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplets coupled with high-performance liquid chromatography was established. The cereal samples were extracted with acetonitrile, cleaned up, and concentrated by green extractant menthol via γ-cyclodextrin assisted extraction process. The extractant menthol dispersed as fine droplets in the cyclodextrin solution and then solidified at room temperature for efficient extraction and convenient collection. The optimized method provided good linearity in the range of 0.01–10 mg kg⁻¹ with limits of detection of 3.5–9.5 μg kg⁻¹. The fortified recoveries of three pyrethroids (i.e., lambda-cyhalothrin, deltamethrin, and bifenthrin) in four cereals (i.e., rice, wheat, maize, and millet) at three levels were in the range of 77.6–101.6% with relative standard deviations of 0.6–6.6%. Overall, the proposed method can be successfully applied for the determination of pyrethroids in cereals.

2

UV polymerization and property analysis of maleacylated methyl cellulose acrylic acid absorbent resin

Li Ying, Sawut Amatjan, Hou Gongbo, He Mingyu, Yimit Mamatjan

Polish Journal of Chemical Technology

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2020

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Vol. 22, nr 2

34--41

EN

In this paper, maleic anhydride (MA) was grafted onto methyl cellulose (MC) and then reacted with acrylic acid to synthesize a high gel strength and fast water absorption resin (AA-co-MC-g-MA) by UV polymerization. The reaction conditions of maleylated methylcellulose (MC-g-MA) were investigated, including the ratio of MC to MA, reaction time and catalyst amount. In addition, the reaction conditions for the synthesis of super absorbent resin were as follows: the amount of MC-g-MA, the degree of substitution of MC-g-MA, polymerization time, and the amount of initiator. Under optimal conditions, the maximum water absorption volume of synthetic resin was 2116 g/g, and the maximum salt absorption rate was 139 g/g. The water absorption resin prepared this time had high water absorption, water retention, excellent pH sensitivity, etc. It was hoped that it will have a good application prospect in the field of industrial production and agriculture in the future.

3

Role of different lignin systems in polymers: mechanical properties and thermal stability

Hasan Gvlmira, Musajan Dilhumar, Hou Gong-bo, He Mingyu, Li Ying, Yimit Mamatjan

Polish Journal of Chemical Technology

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2020

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Vol. 22, nr 4

10--16

EN

Lignin was used to study the mechanical properties and thermal stability of polymers. The lignin was blended with three kinds of polymers, and the addition of lignin was 0.5 wt%. Under the condition of thermal oxidation, the thermal stability of lignin/polymer samples varies with the structure of lignin. The effects of lignin on the mechanical properties and thermal stability of the polymers were investigated by oxidation induction time (OIT), rheological properties, mechanical properties and differential scanning calorimetry (DSC). The results show that the effect of lignin on the thermal properties of polymer samples is 2~3oC. It can be inferred that lignin can effectively improve the interaction between polymer molecular chain segments, and improve the crystallization rate and rigidity to a certain extent, so it can be seen that lignin has good compatibility and thermal stability.

4

Tissue coefficient as a novel index in bioelectric impedance analysis researches and applications

Li Ying, Ma Ren, Wang Xin, Jin Jingna, Wang He, Liu Zhipeng, Yin Tao

Biocybernetics and Biomedical Engineering

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2020

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Vol. 40, no. 3

950--964

EN

Background: Bioimpedance is of great importance in both basic and clinical researches. Though several parameters have been used in detection and analyzing the condition of the tissues and human body epidemically and clinically, we hypothesize that the ratio of resistive and capacitive components of tissues could be discriminative in bioelectric impedance analysis (BIA) related researches. Materials and methods: In this article, we introduced a newly coined parameter, tissue coefficient, to the open data from an online database. Results: The 54 kinds of tissues can be classified into 4 categories: (1) liquid, (2) nail, (3) stomach & muscle, (4) fat & brain. The related time coefficient is especially useful to characterize the liquid-like tissues. Conclusion: The results suggest that the tissue coefficient is promising in distinguishing different tissues, and other BIA-related (bioelectric impedance analysis) scenarios.

5

Research on operation fault diagnosis algorithm of power grid equipment based on power big data

Qian Jianguo, Zhu Bingquan, Li Ying, Shi Zhengchai

Archives of Electrical Engineering

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2020

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Vol. 69, nr 4

793--800

EN

Power big data contains a lot of information related to equipment fault. The analysis and processing of power big data can realize fault diagnosis. This study mainly analyzed the application of association rules in power big data processing. Firstly, the association rules and the Apriori algorithm were introduced. Then, aiming at the shortage of the Apriori algorithm, an IM-Apriori algorithm was designed, and a simulation experiment was carried out. The results showed that the IM-Apriori algorithm had a significant advantage over the Apriori algorithm in the running time. When the number of transactions was 100 000, the running of the IM-Apriori algorithm was 38.42% faster than that of the Apriori algorithm. The IM-Apriori algorithm was little affected by the value of supportmin. Compared with the Extreme Learning Machine (ELM), the IM-Apriori algorithm had better accuracy. The experimental results show the effectiveness of the IM-Apriori algorithm in fault diagnosis, and it can be further promoted and applied in power grid equipment.

6

Badanie in vitro działania chemicznych składników owoców kotewki orzecha wodnego i ich aktywności względem komórek niedrobnokomórkowego raka płuc A549

Mao Zhifang, Wang Qing, Cheng Faxiu, Zhang Zhiyong, Cary, Kang Gongli, Li Ying

Przemysł Chemiczny

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2019

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T. 98, nr 2

204--207

PL

Z łupin owoców kotewki orzecha wodnego wyekstrahowano niektóre składniki chemiczne i oznaczono w nich zawartość polifenoli metodą kolorymetryczną. Do ekstrakcji wykorzystano etanol oraz wodę. Ekstrakt zastosowano do zwalczania komórek raka płuc A549 i sprecyzowano jego działanie hamujące wzrost tych komórek. Zawartość polifenoli w odmianie Trapa natans L. var. incisa Makino była większa niż w odmianie Trapa bicornis var. bispinosa. Lepszym ekstrahentem polifenoli okazał się etanol. Wskaźnik zahamowania wzrostu komórek rakowych A549 ekstraktu alkoholowego z Trapa bicornis var. bispinosa był większy w porównaniu z ekstraktem wodnym, zaś wskaźnik zahamowania wzrostu komórek rakowych ekstraktu wodnego z Trapa natans L. var. incisa Makino był wyższy niż ekstraktu wodnego z Trapa bicornis var. bispinosa.

EN

Some chem. components were extd. from chestnut shells with EtOH or H₂O and studied for content of polyphenols by colorimetric method. The ext. was applied to control lung cancer A549 cells and its growth inhibitory effect was detd. The content of polyphenols in Trapa natans L. var. incisa Makino was higher than that in Trapa bicornis var. bispinosal. EtOH was more efficient in extg. polyphenols than H₂O. The inhibition rate of the EtOH ext. of Trapa bicornis var. bispinosal on lung cancer A549 cells was higher than that of the aq. ext., and the inhibition rate of the aq. ext. of Trapa natans L. var. incisa Makino on the growth of lung cancer A549 cells was higher than that of the aq. ext. in the Trapa bicornis var. bispinosa.

7

Tissue coefficient of bioimpedance spectrometry as an index to discriminate different tissues in vivo

Li Ying, Ma Ren, Wang Xin, Jin Jingna, Wang He, Liu Zhipeng, Yin Tao

Biocybernetics and Biomedical Engineering

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2019

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Vol. 39, no. 3

923--936

EN

Bioimpedance indicating cell and tissue condition of the living things is of great importance in impedance spectrum analysis and other related researches, in which measurement of the skin impedance is a tricky problem due to the peculiarity of the stratum corneum. The aim of the study is to develop a method to elucidate the skin impedance in a large frequency range and to find out a biomarker to estimate it. In this article, we introduce a non-destructive method of using both surface and needle electrodes to investigate the electrical properties of the skin including stratum corneum of sixteen anesthetized C57BL/6 mice in vivo. A capacitance model was introduced to bridge the complex Debye's model and the practical three-element model. A new biomarker (tissue coefficient) was introduced to compare the whole skin with the viable skin. The contribution of the viable skin to the impedance of the whole skin can be ignored unless the concerned frequency is much higher than 10 kHz. The CG plot show direct link with the e-s plot, and the tissue coefficient shows significant difference between the whole skin and viable skin and reflects the alpha and beta dispersions. The results suggest that the method of using both surface and needle electrodes to investigate the impedance the whole skin including stratum corneum is practical, and the tissue coefficient is especially suitable for in vivo study, and has great potentials in estimation and discrimination of living tissues, cancer detection, bioelectrical impedance analysis (BIA) and other related fields.