1.Preparation of Electrospun ZnO-Carbon Composite Nanofiber Modified Electrodes for the Detection of Trace Lead
Xin ZHOU ; Jianmao YANG ; Meng XIN ; Mengni CHEN ; Xing WANG ; Jianyun LIU
Chinese Journal of Analytical Chemistry 2014;(7):985-990
ZnO nanoparticle-containing carbon composite nanofiber ( ZnO-CNF ) was prepared by the electrospinning of the ZnCl2-PAN precursor, followed by preoxidation and carbonization. The ZnO nanoparticles were uniformly distributed on the surface of the carbon nanofiber with the size of 20-30 nm, confirmed by scanning electron microscopy ( SEM ) . The wettability of the ZnO-CNF was studied by water contact angle test. With Nafion as an additive, the ZnO-CNF modified electrode was successfully constructed by dip-coating. The surface morphology and electrochemical properties of the modified electrode were investigated by SEM and cyclic voltammetry. There was a sensitive response of the ZnO-CNF modified electrode on Pb ions in solution, demonstrated by square wave stripping voltammetry. Under the optimized conditions, a good linear relationship between peak current and Pb2+concentration was obtained in the range of 2. 4×10-10-2. 4×10-7 mol/L (R=0. 998) by 10 min preconcentration at -1. 0 V in 0. 1 mol/L NaAc buffer solution (pH=4. 6). The detection limit was 4. 8×10-11 mol/L. The practical analytical application of the ZnO-CNF modified electrode was assessed by the measurement of the actual water sample and the result was consistent with that obtained by ICP-MS.
2.Analysis of polymorphism of Pfhrp2 gene in Plasmodium falciparum from falciparum malaria patients in Yunnan Province
Ying DONG ; Aiming SUN ; Mengni CHEN ; Yanchun XU ; Xianghua MAO ; Yan DENG ; Henlin YANG
Chinese Journal of Schistosomiasis Control 2016;28(4):411-417
Objective To analyze the polymorphism of histidine rich protein 2(HRP II)gene in Plasmodium falciparum (Pfhrp2)from falciparum malaria patients in Yunnan Province,so as to lay the foundation for studying the defection of antigen genes of Plasmodium. Methods The filter paper blood samples and related information of falciparum malaria cases reported were obtained in Yunnan Province from August 2012 to September 2015. Under the guidance of the specific primers,the exon2 regions in Pfhrp2 gene in P. falciparum from DNA samples were amplified by PCR,and the PCR products were sequenced. The sequences of exon2 region in Pfhrp2 gene were blasted by comparing with the reference sequences AY816237,AY816240,and AY816301. Next,the polymorphism of the sequence in exon2 region of Pfhrp2 gene was analyzed by MEGA 5.04 software. The conserved sites and genetic distances between sequences were calculated by using the software as well,and the clustering tree was drawn according to the genetic distances between the amino acid sequences. Results A total of 218 bloods samples from the falciparum malaria cases in 15 prefectures of Yunnan Province were collected,and the sources of infection included Yun?nan,Africa and Myanmar. The PCR results showed that the exon2 regions in Pfhrp2 genes of 155 samples were positive by am?plification and their products were sequenced successfully. The sequence analysis showed that the length range of the amino acid residues of exon2 region in Pfhrp2 gene was from 115 aa to 298 aa,the average length was 239.7 aa. There was no statistically significance among the means of the amino acid residues of the isolates from Africa( 239.9 aa),Myanmar(239.5 aa)and Yun?nan(241.6 aa)(F=0.025,P>0.05). All the 155 amino acid sequences ended with type 12 repeat,98.1%(152/155)of them started with type 1 repeat and 1.9%(3/155)of them started with type 2. Type 2 presented most frequently repeat in all the se?quences and the average repeat times were 12.9. The homologous locus of the DNA sequences in exon2 regions of the 155 Pfhrp2 genes was 894 bp,among which the conservative sites accounted for 20.6%(186/894),and the variable sites for 78.2%(699/894). The genetic distances between the sequences of Africa isolates ranged from 0 to 0.741,and those of the Myanmar and Yun?nan isolates were 0-0.948 and 0-0.750,respectively. The cluster analysis showed that all the 155 sequences clustered into 3 cat?egories on genetic distances between amino acid sequences according to the size of the amino acid sequence length. At the same level,the sequences had approximate lengths and amino acid repeat types. Conclusion The sequence of exon2 region in Pfhrp2 gene of P. falciparum from falciparum malaria cases in Yunnan Province is highly polymorphic,the P. falciparum iso?lates are clustered mainly according to the size of the amino acid sequence of exon2 region in Pfhrp2 gene.
3.Preparation of Zinc Oxide-Graphene Composite Modified Electrodes for Detection of Lead
Yuanyuan LU ; Mengni CHEN ; Yili GAO ; Jianmao YANG ; Xiaoyu MA ; Jianyun LIU
Chinese Journal of Analytical Chemistry 2015;(9):1395-1401
ZnO nanotubes were prepared via electrospinning the Zn ( AC ) 2-polyacrylonitrile-polyvinylpyrrolidone ( PAN-PVP) precursor, followed by thermal decomposition of the above polymers from the precursor fibers. SEM and XRD characterization confirmed that the as-prepared ZnO nanofibers presented the hollow nanotube form, which was composed of ZnO nanoparticles with the size of about 40 nm in wurtzite crystal structure. By mixing with graphene, the obtained ZnO-graphene composite modified glassy carbon electrode ( ZnO-RGO/GCE ) was successfully constructed by dip-coating, which was used for the determination of Pb2+in water. With the sensitive response of the ZnO-RGO/GC electrode to Pb2+in solution was demonstrated by square wave stripping voltammetry, the response pctential was at -0. 4V. Under the optimized conditions, a good linear relationship between peak current and Pb2+ concentration was obtained in the range of 2. 4×10-9-4. 8×10-7 mol/L (R=0. 9970) by 10 min preconcentration at -1. 0 V in 0. 1 mol/L HAc-NaAc buffer solution (pH=4. 6). The detection limit was 4. 8×10-10 mol/L (S/N>3). The ZnO-RGO/GC electrode had good stability. The practical analytical application of the ZnO-RGO modified electrode was assessed by the measurement of the actual water sample and the result was consistent with that obtained by ICP-MS.
4.A qualitative research on the causes of non-adherence to pulmonary rehabilitation exercise in patients with acute exacerbation of chronic obstructive pulmonary disease
Mengni JIN ; Beilei ZHANG ; Daqi CHEN ; Dongmei YANG
Chinese Journal of Practical Nursing 2020;36(34):2660-2664
Objective:To understand the reasons for non-adherence of pulmonary rehabilitation exercise in patients with acute exacerbation of COPD, and in order to provide theoretical and practical basis for improving patient adherence.Methods:Using qualitative phenomenological research methods, eighteen patients of non-adherence with exercise were conducted deeply semi-structured interviews, and the Colaizzi analysis was used for data analysis and extracting themes.Results:Seven themes were extracted: effect of subjective and objective symptoms, limited by comorbidity, negative mood disturbance, lack of perception effect, material environment in ward, cultural environment in ward and inappropriate form of exercise.Conclusions:Health care providers should value these obstacles and implement targeted measures, in order to achieve the goal of improving exercise adherence, so that more patients would complete pulmonary rehabilitation exercise.
5.Mendelian randomization study on the correlation between gluten free diet and rheumatoid arthritis
Yuyan HAN ; Lulu HUANG ; Mengni YANG ; Shihong HUANG ; Yan HUANG ; Yuanyuan XIAO ; Hongying LI ; Yunhui YOU
Chinese Journal of Rheumatology 2024;28(3):162-166
Objective:To evaluate the relationship between gluten-free diet and rheumatoid arthritis (RA).Methods:Data were obtained from large-scale genome-wide association studies (GWAS), and genetic loci that are independent of gluten-free diet and RA of people of Europe2 were selected as instrumental variables. The gluten-free diet GWAS data included 64 949 individuals and 9 851 867 controls. Data were obtained from GWAS of 58 284 RA patients and 13 108 512 controls. The inverse variance weighted (IVW), MR Egger, weighted median method and weighted model were used to conduct two sample Mendelian randomization (MR) analysis. Cochran Q test and mendelian randomness pleiotropy residual sum and outlier (MR-PRESSO) were used to assess SNP heterogeneity. Applying the MR Egger intercept to test the level pleiotropy of SNP. The sensitivity analysis of the "leave one method" that evaluates whether MR studies were influenced by a single SNP. Results:After matching GFD and RA data, three SNPs were included as instrumental variables in the study. IVW showed that GFD could significantly reduce the risk of RA ( β=-60.83, s x=3.82, P<0.001). The weighted median method and weighted pattern also showed that the gluten free diet could reduce the risk of RA ( β=-57.97, s x=4.41, P<0.001; β=-55.81, s x=5.10, P=0.008). Sensitivity analysis of the correlation between GFD and RA showed that there might be heterogeneity between SNPs (Cochran Q test, Q=12.80, P=0.002). The MR-PRESSO results showed that no abnormal SNP was detected ( P=0.174). The forest map showed that SNPs was closely related to GFD and RA stability. The method comparison chart showed that the results of multiple testing methods were basically consistent. The funnel plot showed that SNPs were basically symmetrical, indicating that there was no pleiotropy in MR analysis. The MR Egger intercept test showed no horizontal pleiotropy in MR analysis (intercept value was-0.24, P=0.174). The sensitivity analysis of the "leave one method" is suggested that no single SNP had a significant impact on the overall results. Conclusion:Gluten free diet is related to the risk reduction of RA.
6.Early Warning Model of Fall Risk for the Elderly Based on Gait Characteristics
Yonghao YOU ; Mengni SHAO ; Yanjie HU ; Yang ZHANG ; Guanglei WANG ; Jingjing ZHU
Journal of Medical Biomechanics 2020;35(4):E489-E495
Objective To construct an early warning model of fall risk for the elderly based on six kinds gait parameters. Methods A digital field was used to collect parameters from six kinds of gait for the elderly with or without the history of falls, and the binomial logistic regression analysis was used to establish a regression equation for predicting the fall risks in the elderly, and an early warning model was constructed. Results The regression equations constructed according to the parameters from six kinds of gait were statistically significant. The overall correct rate was predicted from high to low: walking forward with closed eyes (97.1%), walking backward with open eyes (92.9%), walking backward with closed eyes (88.6%), walking forward with open eyes (87.1%), turning head up and down with open eyes (85.7%), turning head left and right with open eyes(82.9%). The constructed early warning model for fall risk of the elderly mainly included five steps, namely, judgment, test, extraction, calculation and early warning, which was suitable for gait testing and evaluation of the elderly in the laboratory. Conclusions Parameters from six kinds of gait could predict the fall risk of the elderly. Among them, walking forward with closed eyes was best to predict the fall risk in the elderly. The established early warning model of fall risk for the elderly could be used to predict the fall risk of 65-75 year old people within one year, which could provide early warning based on the probability of falling, playing a positive effect on preventing falls in the elderly.