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Copyright of Computer Engineering & Science / Jisuanji Gongcheng yu Kexue is the property of Computer Engineering & Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Public emergencies occur constantly. How to apply history public emergencies and obtain corresponding solutions rapidly is the key problem for coping with public emergencies. The level system of entity of public emergencies is researched, and the public attributes are described and extracted. OWL language is adopted to describe the ontology of public emergency, the definition of meta event is proposed, and the relationship among the meta events is discussed. Combining the related theory of CBR, the reasoning mechanism based on meta event is put forward, which will make decision-maker obtain the disposal schema rapidly according to meta event database. Finally, an example testified the feasibility. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of miR-101 on biological behaviors of colorectal cancer cell line SW620., Methods: CCK-8 method, colony formation assay, cell cycle analysis and apoptosis analysis were applied to assess the effects of miR-101 on cell proliferation, invasion and apoptosis of SW620 cells., Results: Over-expression of miR-101 in SW620 cells significantly suppressed the cell proliferation and attenuated the colony-forming ability of the cells. Flow cytometry showed that over-expression of miR-101 in SW620 cells caused obvious cell cycle arrest in G2/M and 1/ phases, and significantly increased the cell apoptosis rate., Conclusion: Over-expression of miR-101 can inhibit the proliferation, cause cell cycle arrest and promote apoptosis of colorectal cancer SW620 cells.

Objective: To construct a lentiviral vector of miR-335 gene and verify the target gene of miR-335., Methods: The precursor sequence of miR-335 gene was amplified from the genomic DNA by PCR and cloned into the lentiviral vector PLVTHM labeled with GFP. Real-time quantitative RT-PCR was used to detect miR-335 and RASA1 expression in different colorectal cancer cell lines. A recombinant vector psiCHECK-2-RASA1 containing RASA1 3'UTR was constructed followed by site-directed mutagenesis of RASA1 3'UTR to establish the vector psiCHECK-2-RASA1-Mut. Co-transfection of hsa-mir-335 or a NC with these recombined vectors in HEK293A and SW480 cells was performed, and dual-luciferase reporter assay was utilized to examine the changes in luciferase activities. The recombinant PLVTHM-miR335 plasmid was packaged into mature lentivirus by 293FT cells and used to infect SW620 cells. Flow cytometry was employed for sorting the GFP+ cells. The expression of miR-335 and RASA1 were determined by qRT-PCR, and Western blotting was used to detect the expression of RASA1 protein in SW620 cell lines., Results: The recombinant lentiviral vector PLVTHM-miR335, psiCHECK-2-RASA1 and the mutation expression vector psiCHECK-2-RASA1-Mut were successfully constructed. Dual-luciferase reporter assay showed that miR-335 decreased luciferase activity in cells co-transfected with psiCHECK-2-RASA1. The expression of miR-335 in SW620 cells infected with the lentivirus PLVTHM-miR335 was significantly increased, but the expression of RASA1 showed only slight changes. Overexpression of miR-335 suppressed the expression of RASA1 protein in SW620 cells., Conclusion: We have successfully constructed the lentiviral vector containing mir-335 gene and a SW620 cell line with miR-335 overexpression. MiR-335 can suppress RASA1 gene expression by targeting the specific sequence of RASA1 3'UTR.

Objective: To isolate CD133(+) hematopoietic progenitor cells from human umbilical cord blood and optimize the culture condition for maintaining their stem cell characteristics., Methods: CD133(+) hematopoietic progenitor cells were isolated from human umbilical cord blood using magnetic cell sorting system, and the cells were detected by flow cytometry. Four methods were used for culturing cells. After 8 weeks' culture, cytomorphology, flow cytometry, immunocytochemistry and immunofluorescence assay were used to identify the characteristics of the stem cells., Results: Over 80% of CD133(+) hematopoietic progenitor cells were isolated from human umbilical cord blood using magnetic cell sorting system. The cells were effectively expanded using optimized serum-free medium after 8 weeks of cell culture, whereas the cells in other media differentiated into adherent cells in a poor state., Conclusion: The optimized serum-free medium allows effective expansion of CD133(+) hematopoietic progenitor cells that maintain stem cell characteristics after a long-term culture.

Objective: To select the peptides that specifically bind human cancer stem cell surface marker CD133 from the Ph.D.-7>(TM) phage peptide library., Methods: With a biotinylated extracellular fragment of human cancer stem cell surface marker CD133 as the target protein, the CD133 high-affinity peptides were screened from the phage peptide library by liquid phase panning. The clones with high-binding force with human CD133 were then identified by sandwich ELISA and their single-stranded DNA was extracted to test the specificity by competitive ELISA. The amino acid sequences of the selected peptides derived from the phage DNA sequences were synthesized after sequence alignment analysis, and their capacity of binding with colorectal carcinoma cells was assessed by immunofluorescence technique., Results: After 4 rounds of liquid phase selection, the phages capable of specific binding with human CD133 were effectively enriched, with an enrichment ratio of 388 times compared to that at the fourth and first rounds. Thirteen out of the 20 clones from the fourth round of panning were identified as positive clones, among which 11 had identical amino acid sequence of TISWPPR, and 2 had the sequence of STTKLAL, and the former sequence showed a stronger binding specificity to CD133., Conclusion: We have successfully obtained a peptide that specifically binds human CD133 from the Ph.D.-7(TM) phage peptide library, demonstrating the feasibility of screening small molecule high-affinity polypeptides from phage peptide library by liquid-phase panning.