Impact of electrolyte additives (alkali metal salts) on the capacitive behavior of NiO-based capacitors

Yong Zhang,Lizhen Wang,Aiqin Zhang,Yanhua Song,Xiaofeng Li,Xingbing Wu,Peipei Du,Lv Yan 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.2

To improve the specific capacitance and energy density of electrochemical capacitor, nanostructured NiO was prepared by high temperature solid-state method as electrode material. The crystal structure and morphology of as-parepared NiO samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Cyclic voltammetry (CV) measurement was applied to investigate the specific capacitance of the NiO electrode. Furthermore,a novel mixed electrolyte consisting of NaOH, KOH, LiOH and Li_2CO_3 was prepared for the NiO capacitor,and the component and concentration of the four different electrolytes was examined by orthogonal test. The results showed that the NiO sample has cubic structure with nano-size particles, and the optimal composition of the electrolyte was: NaOH 2 mol L^(−1), KOH 3 mol L^(−1), LiOH 0.05 mol L^(−1), and Li_2CO_3 0.05 mol L^−1. At a scan rate of 10 mV s^(−1), the fabricated capacitor exhibits excellent electrochemical capacitive performance, while the specific capacitance and the energy density were 239 F g^(−1) and 85 Wh kg^(−1), which was higher than one-component electrolyte.

Computing Minimal Curvature Variation in Curve Construction Using Computer Simulation Technique

Peipei Li,Caiming Zhang (사)한국CDE학회 2010 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

Comparing the normalization methods for the differential analysis of Illumina high-throughput RNA-Seq data

Li, Peipei,Piao, Yongjun,Shon, Ho Sun,Ryu, Keun Ho BioMed Central 2015 BMC bioinformatics Vol.16 No.-

<P><B>Background</B></P><P>Recently, rapid improvements in technology and decrease in sequencing costs have made RNA-Seq a widely used technique to quantify gene expression levels. Various normalization approaches have been proposed, owing to the importance of normalization in the analysis of RNA-Seq data. A comparison of recently proposed normalization methods is required to generate suitable guidelines for the selection of the most appropriate approach for future experiments.</P><P><B>Results</B></P><P>In this paper, we compared eight non-abundance (RC, UQ, Med, TMM, DESeq, Q, RPKM, and ERPKM) and two abundance estimation normalization methods (RSEM and Sailfish). The experiments were based on real Illumina high-throughput RNA-Seq of 35- and 76-nucleotide sequences produced in the MAQC project and simulation reads. Reads were mapped with human genome obtained from UCSC Genome Browser Database. For precise evaluation, we investigated Spearman correlation between the normalization results from RNA-Seq and MAQC qRT-PCR values for 996 genes. Based on this work, we showed that out of the eight non-abundance estimation normalization methods, RC, UQ, Med, TMM, DESeq, and Q gave similar normalization results for all data sets. For RNA-Seq of a 35-nucleotide sequence, RPKM showed the highest correlation results, but for RNA-Seq of a 76-nucleotide sequence, least correlation was observed than the other methods. ERPKM did not improve results than RPKM. Between two abundance estimation normalization methods, for RNA-Seq of a 35-nucleotide sequence, higher correlation was obtained with Sailfish than that with RSEM, which was better than without using abundance estimation methods. However, for RNA-Seq of a 76-nucleotide sequence, the results achieved by RSEM were similar to without applying abundance estimation methods, and were much better than with Sailfish. Furthermore, we found that adding a poly-A tail increased alignment numbers, but did not improve normalization results.</P><P><B>Conclusion</B></P><P>Spearman correlation analysis revealed that RC, UQ, Med, TMM, DESeq, and Q did not noticeably improve gene expression normalization, regardless of read length. Other normalization methods were more efficient when alignment accuracy was low; Sailfish with RPKM gave the best normalization results. When alignment accuracy was high, RC was sufficient for gene expression calculation. And we suggest ignoring poly-A tail during differential gene expression analysis.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s12859-015-0778-7) contains supplementary material, which is available to authorized users.</P>

Epigenetic inactivation of ACAT1 promotes epithelial-mesenchymal transition of clear cell renal cell carcinoma

Han Peipei,Wu Shu,Li Limei,Li Danping,Zhao Jun,Zhang Haishan,Wang Yifang,Zhong Xuemin,Zhang Zhe,Li Ping,Matskova Liudmila,Zhou Xiaoying 한국유전학회 2022 Genes & Genomics Vol.44 No.4

Background: Acetyl-CoA acyltransferase 1 (ACAT1) is a key enzyme catalyzing the production of mitochondrial ketone bodies. We have shown that ACAT1 is down-regulated in kidney renal clear cell carcinoma (KIRC) previously. Objective: To investigate the reasons for downregulation of ACAT1 in KIRC and explore the underlying mechanisms involved in metastatic inhibition regulated by ACAT1. Methods: The Gene Expression Omnibus (GEO) database was queried for meta-analysis of ACAT1 mRNA expression in KIRC. The UALCAN website was used to compare the methylation levels of the ACAT1 promoter region in KIRC and normal tissues. RT-qPCR was used to quantitate ACAT1 transcription levels. The GCBI and Tarbase V.8 databases were used to predict miRNAs that may target the mRNA of ACAT1. The correlation between mRNA expression of ACAT1, MMP7 (matrix metallopeptidase 7), CDH1 (E-cadherin), EpCAM (epithelial cell adhesion molecule), and VIM (vimentin) was analyzed. Extracellular MMP7 protein was quantitated using an ELISA assay. Results: The methylation level of the ACAT1 promoter region in KIRC was significantly higher than that in the normal kidney tissues. The ACAT1 mRNA expression in the KIRC cell lines was restored after treatment with 5-aza-dC (p < 0.05). MiR-21-5p is a conserved microRNA targeting ACAT1. It is expressed at a significantly higher level in KIRC than in normal tissues (p < 0.001). MiR-21-5p miRNA expression negatively correlates with ACAT1 mRNA expression. The expression of miR-21-5p is higher at the T3-T4 stages and in the histologic grades G3-G4. Patients with high miR-21-5p expression tended to have lower overall survival, suggesting that miR-21-5p could serve as a potentially valuable diagnostic biomarker for KIRC (AUC = 0.957; p < 0.001). A mimetic of miR-21-5p inhibited the expression of ACAT1 mRNA and protein. In addition, ACAT1 mRNA expression positively correlates with CDH1 and EpCAM but is negatively correlated with VIM. Overexpression of ACAT1 suppresses the secretion of MMP7 in KIRC cells. Conclusion: Expression of ACAT1 in KIRC is controlled at two levels, firstly by the hypermethylation of the ACAT1 promoter region and secondly by overexpression of miR-21-5p. Downregulation of ACAT1 expression correlates with epithelial-mesenchymal transition (EMT).

An Energy-efficient Transmission Scheme for Wireless Sensor Network with DSC and virtual MIMO

Guoqiang Zheng,Fangge Nie,Bing Li,Huahong Ma,Jishun Li,Yujun Xue,Peipei Li 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.10

Energy efficiency is one of the primary performance parametersin wireless sensor network (WSN). The data collected by neighboring nodesin the high density WSN tend to have a high correlation which isdirectly transmitted to the sink node (DGN) will seriously reduce the energy efficiency of wireless sensor networks.For improving the energy efficiency of high node density WSN, We introduce distributed source coding (DSC) which can compress the high correlation source data into WSNbased on virtual MIMO. In the simulationresults indicate thatDSC can effectively reduce the energy consumption in data transmission and improve the energy efficiencyof the whole WSN.

Kinetics and Modeling for Extraction of Chrysin from Oroxylum indicum Seeds

Li Zhou,Ting Jing,Peipei Zhang,Liqin Zhang,Shaona Cai,Tingting Liu,Huihui Fan,Guangde Yang,Rong Lin,Jiye Zhang 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.6

Research on extraction of chrysin is crucial for theoretical purposes and for food industrial bioprocesses. Optimization and kinetics of chrysin extraction from seeds of Oroxylum indicum (L.) Vent. were analyzed using agitated solid-liquid extractions with ethanol and water mixtures. The influence of extraction process parameters was investigated. Optimized conditions for chrysin extraction were a 0.2 mole fraction of ethanol as an extraction solvent, a temperature of 318 K, an agitation speed 1,400 rpm, and a solid to solvent ratio of 1:30. The extraction kinetic behavior of chrysin followed first order kinetics. The kinetic expression developed by Spiro and Siddique was used and the model was in agreement with experimental results. The diffusion coefficient ranged from 1.38×10−11 to 19.43×10−11 m2·s−1 and the activation energy for extraction kinetics was 21.85 kJ·mol−1.

A Single Center Analysis of the Positivity of Hepatitis B Antibody after Neonatal Vaccination Program in Korea

김용주,Peipei Li,홍종면,류근호,남은우,장미수 대한의학회 2017 Journal of Korean medical science Vol.32 No.5

The antibody to hepatitis B surface antigen (anti-HBs) seropositivity rate after 3 doses of hepatitis B virus (HBV) vaccination during infancy period is known to be higher than 90%. However, a considerable number of vaccines do not form protective anti-HBs or chronologic decrease of anti-HBs. We retrospectively collected data of HBV serologic test results in 20,738 individuals from 2000 to 2015. After exclusion criteria were applied, 19,072 individuals were included. We analyzed the anti-HBs seropositivity rate, anti-HBs disappearance rate, anti-HBs positive seroconversion rate after receiving a booster vaccine, and the difference in anti-HBs positivity between the 2 groups; group A (born before 2005, while both recombinant vaccines and plasma-derived vaccines were used) and group B (born after 2005, when only recombinant vaccines were used by national regulation). The anti-HBs seropositivity rate was 55.8%, but there was a significant difference in the rate of seropositivity for anti-HBs between the group A and B (53.0% vs. 78.1%, P < 0.001). There was no significant age-adjusted difference in the mean seropositivity rate between the 2 groups (P = 0.058). In addition, the anti-HBs positivity rate was significantly lower in the group A as compared with the group B during infancy (83.1% vs. 92.1%, P < 0.001). A total of 1,106 anti-HBs-positive subjects underwent serologic tests more than twice. Of these, 217 subjects (19.6%) showed anti-HBs disappearance. After booster vaccinations, 87.4% (83/95) achieved seroconversion from seronegative to seropositive. Our results highlight the importance of lifelong protection against HBV and the possible necessity of booster vaccination after adolescent period.

A Dynamic Control Method for Cavs Platoon Based on the MPC Framework and Safety Potential Field Model

Linheng Li,Jing Gan,Xu Qu,Wenqi Lu,Peipei Mao,Bin Ran 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.5

Safety and efficiency have always been significant challenges to the development of road traffic. Detailed vehicle motion information is the prerequisite for achieving optimal control of the platoon and improving traffic safety and efficiency. The connected and automated vehicles (CAVs) system has offered unprecedented opportunities for the real-time collection and processing of these detailed vehicle motion data. Based on the model predictive control (MPC) framework and safety potential field (SPF) model, we developed an alternative CAVs platoon dynamic control method. The SPF model was applied to describe the road risk distribution under the complex driving environment and was embedded in the MPC framework to optimize the vehicle dynamics from the perspective of capacity, safety, and energy-saving. Also, some experiments were performed to verify the validity of our platoon control strategy. Compared with the fixed time-headway strategy, our proposed strategy can increase the traffic capacity by about 24.4%, while ensuring safety and improving fuel economy. The results indicate that the novel CAVs platoon control methodology proposed in this paper can be potentially applied to alleviate various traffic problems (e.g., traffic congestion, traffic accidents, and high emissions).

現代漢語動量詞次類的再劃分 - 基于?知?言?的?角 -

李明晶(Li, Mingjing),?沛沛(Zhang, Peipei) 한국중국어교육학회 2020 중국어교육과연구 Vol.0 No.31

Isolation, identification and characterization of a novel elastase from Chryseobacterium indologenes

Yunlong Lei,Peipei Zhao,Chenglei Li,Haixia Zhao,Zhi Shan,Qi Wu 한국응용생명화학회 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.3

Elastase is a type of protease that specifically degrades elastin. It has broad application prospects in medicine, food industry, and daily-use chemical industry. In this study, we isolated a bacterial strain WZE87 with high elastin-hydrolysis activity, which was identified as Chryseobacterium indologenes based on morphology, physiological and biochemical characteristics, and 16S rDNA sequence analysis. The elastase produced by this strain was purified by three steps: ammonium sulfate precipitation, Q-Sepharose fast-flow anion-exchange chromatography, and Sephadex G-75 gel-filtration chromatography. The purified elastase was 2376.5 U/mg in activity (a 8.3-fold increase in specific activity), and the recovery was 5.8%. Its molecular mass was estimated to be 26 kDa by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. This enzyme was stable in the pH range of 5.0–10.5 at 37 C. The optimal temperature and pH were 37 C and 7.5, respectively. The activity of this elastase was found to decrease when the temperature was higher than 50 C. The activity was also inhibited by Zn2?, Fe2?, Fe3?, and Mn2? ions. The specific hydrolytic ability of this enzyme was similar to that of papain on substrates like gelatin, casein, soybean-isolated protein and bovine hemoglobin. However, this elastase preferentially hydrolyzed elastin in a protein mixture because of its specific adsorption. Considering its promising properties, this protease may be considered a potential candidate for applications in related industries.