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Objective To investigate the time distribution characteristics and the epidemic trends of imported malaria cases in Yunnan Province. Methods The malaria case records and epidemiological history data of Yunnan Province were collected, and the local infection cases were excluded. The data were statistical analyzed. Results The imported malaria cases had a sig-nificantly seasonal periodicity(Q=26.574,P0.05). By using the model to predict the cases in January,February and March of 2016,the num-ber(95％CI)were 29(7-50),22(0-44)and 31(8-54),and the actual number of imported malaria cases were 29,24 and 38 cases respectively and all cases were included in the 95％CI. Conclusion The imported malaria cases in Yunnan Province had a significantly seasonal periodicity and epidemic trends,and the established model has good prediction on the recent cases.
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Objective To understand the geographical features of malaria in Yunnan Province,so as to provide the refer?ence for malaria elimination. Methods The data of malaria in Yunnan Province from 2012 to 2015 were collected and ana?lyzed. Results Totally 2 586 malaria cases were reported in Yunnan Province from 2012 to 2015,in which 274(10.60%) were local cases and 2 311(89.37%)were abroad imported,and one(0.03%)was domestic imported. The imported malaria cases and local cases were analyzed according to the sources and locations respectively,and the arithmetic means of the num?bers of imported and local cases were 96.29 and 10.96 respectively,the standard deviations of the numbers of imported and local cases were 421.18 and 19.12 respectively,and the difference of the means was not significant(Z=-0.326,P>0.10). Both the imported and local malaria cases could be clustered into five sections by the number of 5. The Herfendal?Hirshman indexes of the imported and local malaria cases were 8 121 and 1 598 respectively. Conclusions There is no significant difference of the distribution between the imported and local malaria cases,and they should be attaching equal importance. The non?uniform de?gree of imported cases is higher than that of the local cases,while both of them could be divided into five major clusters in the prevention and control work.
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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.
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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.
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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.