Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has...Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.展开更多
Objective To understand the mechanism of invasion by Legionella dumoffii. Methods The L. dumoffii strain Tex-KL was mutated using the Tn903 derivative, Tn903 d IIlac Z. After screening 799 transposon insertion mutants...Objective To understand the mechanism of invasion by Legionella dumoffii. Methods The L. dumoffii strain Tex-KL was mutated using the Tn903 derivative, Tn903 d IIlac Z. After screening 799 transposon insertion mutants, we isolated one defective mutant. We then constructed the gene-disrupted mutant, KL16, and studied its invasion of and intracellular growth in He La and A549 cells, and in A/J mice survival experiments. The structure of traC-traD operon was analyzed by RT-PCR. Results The transposon insertion was in a gene homologous to Salmonella typhi tra C, which is required for the assembly of F pilin into the mature F pilus structure and for conjugal DNA transmission. Results from RT-PCR suggested that the traC-traD region formed an operon. We found that when the tra C gene was disrupted, invasion and intracellular growth of L. dumoffii Tex-KL were impaired in human epithelial cells. When mice were infected by intranasal inoculation with a tra C deficient mutant, their survival significantly increased when compared to mice infected with the wild-type strain. Conclusion Our results indicated that the traC-traD operon is required for the invasion and intracellular growth abilities of L. dumoffii Tex-KL in epithelial cells.展开更多
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2012BAD35B04)
文摘Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.
基金supported by the National Natural Scientific Foundation(No.81201251)from the Ministry of Science and Technology of the People’s Republic of Chinathe Priority Project on Infectious Disease Control and Prevention(No.2012ZX10004215 and 2013ZX10004-610-007)from the Ministry of Health and the Ministry of Science and Technology of the People’s Republic of Chinathe Science Foundation for the State Key Laboratory for Infectious Disease Prevention and Control from China(Grant No.2015SKLID508 and 2011SKLID202)
文摘Objective To understand the mechanism of invasion by Legionella dumoffii. Methods The L. dumoffii strain Tex-KL was mutated using the Tn903 derivative, Tn903 d IIlac Z. After screening 799 transposon insertion mutants, we isolated one defective mutant. We then constructed the gene-disrupted mutant, KL16, and studied its invasion of and intracellular growth in He La and A549 cells, and in A/J mice survival experiments. The structure of traC-traD operon was analyzed by RT-PCR. Results The transposon insertion was in a gene homologous to Salmonella typhi tra C, which is required for the assembly of F pilin into the mature F pilus structure and for conjugal DNA transmission. Results from RT-PCR suggested that the traC-traD region formed an operon. We found that when the tra C gene was disrupted, invasion and intracellular growth of L. dumoffii Tex-KL were impaired in human epithelial cells. When mice were infected by intranasal inoculation with a tra C deficient mutant, their survival significantly increased when compared to mice infected with the wild-type strain. Conclusion Our results indicated that the traC-traD operon is required for the invasion and intracellular growth abilities of L. dumoffii Tex-KL in epithelial cells.
