Quantum key distribution with prepare-and-measure Bell test.

The prepare-and-measure quantum key distribution (QKD) has the merits of fast speed, high key generation rate, and easy implementation. However, the detector side channel attacks greatly undermine the security of the key bits. The eavesdropper, Eve, exploits the flaws of the detectors to obtain illegal information without violating quantum principles. It means that she can intervene in the communication without being detected. A prepare-and-measure Bell test protocol will be proposed. By randomly carrying out Bell test at the side of the information receiver, Bob, Eve's illegal information gain within the detector side channel attack can be well bounded. This protocol does not require any improvement on the detectors used in available prepare-and-measure QKD. Though we only illustrate its application in the BB84 protocol, it is applicable for any prepare-and-measure QKD.

Screening of differentially expressed microRNA in ulcerative colitis related colorectal cancer.

OBJECTIVE: To investigate the differential expression of microRNA (miRNA) in colon between ulcerative colitis (UC) and ulcerative colitis related colorectal cancer (UCRCC). METHODS: An UC mouse model was built by dextran sodium sulfate, and an UCRCC mouse model by dextran sodium sulfate and 1,2-diformylhydrazine. RNAs were extracted from the colon, purified and hybridized with fluorescence-labeled miRNA oligonucleotide gene chip. Real-time fluorescence quantitative PCR was used to verify the expression variation of miRNA. SAM was employed for the data analysis. RESULTS: The up-regulated miRNAs in colon cancer included has-miR-194, has-miR-215, has-miR-93, has-miR-192, has-miR-92a, has-miR-29b, and has-miR-20a (median false discovery rate<5%), while the down-regulated miRNAs were has-miR-1231, has-miR-195, has-miR-143, and has-miR-145 (median false discovery rate<5%). CONCLUSIONS: Significant differential expression of miRNA was found between the UC mouse and UCRCC mouse, which may be related to the onset, erosion and transfer of colorectal cancer.

Identification of microRNA target genes in vivo.

MicroRNAs (miRNAs) are short non-coding RNAs transcribed from intergenic or intronic sequences as long precursors that are sequentially processed by the endonucleases Drosha and Dicer into short double-stranded sequences. It is clear that miRNAs play essential roles in gene expression, development, and cell fate specification in animals. However, one of the barriers of miRNA research is how to find the target genes. In this study, we have developed a rapid and effective method to isolate miRNA target genes in vivo. MicroRNA was synthesized in vitro and labeled by biotin. After transfected into cells, the miRNA/mRNA complexes were isolated by streptavidin-coated magnetic beads. hsa-miR155 was taken as model to validate this method, which is a very important modulator in tumor development. It is useful for validation of targets predicted in silico, and, potentially, for discovery of previously uncharacterized targets.