Rapid detection of pathogenic microorganisms is important to the prevention and control of diseases.Com-pared with traditional approaches, electrochemical DNA biosensors present great advantages in promising rapid, portable, sensitive and cost-saving detection of pathogens.In this review, the working principle of electrochemical DNA biosensors and the progress in detection of pathogens is introduced, the latest developments of DNA tetrahedron structure and new nano materials in electrochemical DNA biosensors are reviewed, and the challenges to and prospects of development in this field are also discussed.

Objective To establish a quick electrochemical biosensor for the detection of nucleic acid of Ebola virus . Methods The DNA tetrahedral nanostructure was self-assembled on gold surface by strong Au-S chemical bonds , leaving the target probe at the top .A biotinylated-ssDNA was introduced as the detection probe by specific binding of the captured target sequence , before avidin-horseradish peroxidase ( HRP) was used as a signal amplifier to transduce amperometric sig-nal through interactions with TMB substrate .Results The results indicated that the nucleotide sequence of Ebola virus could be recognized and detected by the sensor .The linear range for the detection of target DNA was from 1.0 ×10 -9 to 5.0 ×10 -6 mol/L,and the detection limit was 5.2 ×10 -10 mol/L.Conclusion The fabricated sensor is demonstrated to be sensitive and specific for the detection of Ebola virus nucleotide .

OBJECTIVETo explore the prevalence and the different risk factors for asthma in children between urban and rural areas in Fuzhou, Fujian province.

METHODThe epidemiological survey of asthma in 0-14 years old children was conducted from October 2009 to October 2010 between Fuzhou urban and rural areas in Fujian province. The investigation subjects were selected in urban and rural areas by phased stratified random cluster sampling. The 2010 third national epidemiological survey questionnaire of children with asthma was used for screening for possible patients. Diagnosis of asthma was confirmed by physical examination. The children with asthma were designated as the positive cases, while non asthmatic children who were age, gender, ethnic, and living environment matched with asthmatic patients were designated as negative control. Comparison of the prevalence of asthma in children between Fuzhou urban and rural areas was performed. The influencing factors of asthma were analyzed and screened by the regression equation model of two element Logistic regression.

RESULTTotally 12 235 questionnaires of children with asthma and allergic disease screening were issued and 11 738 questionnaire were sent back (6 221 were male and 5 517 were female). The return rate was 95.9% in urban Fuzhou; 648 children were diagnosed as asthma. The prevalence of asthma in male was 6.48% and female children was 4.44% (comparison of the prevalence of gender χ(2) = 23.267, P < 0.001) in urban areas . A total of 6 000 questionnaires of children with asthma and allergic disease screening were sent out and 5 860 were responded (male children 3 228, female children 2 632). The recovery rate was 97.7% in rural Fuzhou; 135 children with asthma was diagnosed. The prevalence of asthma in male was 2.73%and female children and was 1.79%. Adding protein supplement before 6 months (OR = 1.908, 95%CI:1.233-2.959), the use of antibiotics in the treatment of asthma (OR = 14.541, 95%CI:8.920-23.705), furniture materials (non wood) (OR = 2.432, 95%CI:1.563-3.785) were the main risk factors of children with asthma in urban. Adding protein supplement before 6 months(OR = 3.021, 95%CI:1.357-6.711), the use of antibiotics in the treatment of asthma(OR = 14.784, 95%CI:3.842-56.885), the use of coal as fuel (OR = 63.339, 95% CI: 7.993-501.943), domesticated livestock (OR = 13.659, 95% CI:1.342-139.068), the family smoking before and after birth (OR = 6.226, 95%CI:2.674-14.495) and chemical fiber pillow (OR = 3.638, 95%CI:1.241-10.666) were the main risk factors of children with asthma in rural areas.

CONCLUSIONThe prevalence of children with asthma in urban areas was higher than that in rural areas. The prevalence of asthma in male children was higher than in female children. Adding protein food supplement before 6 months, the use of antibiotics and non solid wood furniture material were the main risk factors in children with asthma in urban areas. Adding protein supplement before 6 months, the use of antibiotics, domesticated livestock, the use of coal as fuel and the family smoking before and after birth were the main risk factor of asthma in children in rural areas.

Adolescent ; Anti-Bacterial Agents ; administration & dosage ; adverse effects ; Asthma ; epidemiology ; etiology ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Logistic Models ; Male ; Prevalence ; Risk Factors ; Rural Population ; statistics & numerical data ; Sampling Studies ; Smoking ; adverse effects ; Surveys and Questionnaires ; Urban Population ; statistics & numerical data