Plug-and-play round-robin differential phase-shift quantum key distribution.

The round-robin differential-phase-shift quantum key distribution (RRDPS-QKD) protocol could provide an effective way to estimate the leakage information without monitoring the signal disturbance. Moreover, the self-compensating property of plug-and-play (P&P) setup can eliminate the variations of phase or polarization in QKD procedure. In the paper, we introduce the P&P concept into RRDPS-QKD, and propose a QKD protocol, named P&P RRDPS-QKD protocol, to make the RRDPS-QKD scheme more practical. We analyze the security, and discuss the key generation rate with infinite-intensity decoy state method. The results show that the proposed protocol is a good solution to RRDPS-QKD protocol with untrusted sources. It has a high security and its key generation rate could be as good as the protocol with trusted sources when the average input photon number N is greater than 106. In addition, the proposed protocol has a high noise tolerance in comparison with P&P BB84-QKD protocol.

Cloning and truncation modification of trehalose-6-phosphate synthase gene from Selaginella pulvinata.

A homologous sequence was amplified from resurrection plant Selaginella pulvinta by RACE technique, proved to be the full-length cDNA of trehalose-6-phosphate synthase gene by homologous alignment and yeast complementation assay, and nominated as SpTPS1 gene. The open reading frame of this gene was truncated 225bp at the 5'-end, resulting the N-terminal truncation modification of 75 amino acids for its encoding protein. The TPS1 deletion mutant strain YSH290 of the brewer's yeast transformed by the truncated gene SpTPS1Δ and its original full-length version restored growth on the medium with glucose as a sole carbon source and displayed growth curves with no significant difference, indicating their encoding proteins functioning as TPS enzyme. The TPS activity of the mutant strain transformed by the truncated gene SpTPS1Δ was about six fold higher than that transformed by its original version, reasoning that the extra N-terminal extension of the full-length amino acid sequence acts as an inhibitory domain to trehalose synthesis. However, the trehalose accumulation of the mutant strain transformed by the truncated gene SpTPS1Δ was only 8% higher than that transformed by its original version. This result is explained by the feedback balance of trehalose content coordinated by the comparative activities between trehalose synthase and trehalase. The truncated gene SpTPS1Δ is suggested to be used in transgenic operation, together with the inhibition of trehalase activity by the application of validamycin A or genetic deficiency of the endogenous trehalase gene, for the enhancement of trehalose accumulation and improvement of abiotic tolerance in transgenic plants.

[A preliminary study on the relationship between HLA-Cw polymorphism and susceptibility to pulmonary tuberculosis].

OBJECTIVE: To analyze the relationship between HLA-Cw polymorphism and susceptibility to pulmonary tuberculosis (PTB), and therefore to explore the susceptible or resistant genes of PTB. METHODS: A hundred and twelve patients who were confirmed to have secondary PTB in Shandong Chest Hospital from May 2010 to May 2011 were selected as the PTB group, including 62 males and 50 females aged 19 - 69 years (mean 41.7). According to the acid-fast staining results, PTB patients were divided into a smear-negative group (SN group, 77 cases) and a smear-positive group (SP group, 35 cases). A hundred and ten subjects who underwent physical examination in Shandong Chest Hospital at the same period were selected as the control group, including 59 males and 51 females aged 21 - 67 years (mean 38.3). After genomic DNA was extracted, genotyping of HLA-Cw was conducted by sequence specific primer polymerase chain reaction (PCR-SSP) method. Then Hardy-Weinberg (H-W) equilibrium was tested, and gene frequencies(%) were estimated = 1-(1-phenotype frequencies)(1/2). Gene frequencies were compared between the PTB group and the control group, and between the SN group and SP group by χ(2) test. According to Bonferroni's principle, α was divided by the number of alleles (n = 8), and P < 0.006 25 was regarded as statistically significant. RESULTS: The frequency of HLA-Cw08 was significantly higher in PTB patients (43.6%, 75/112) compared with the controls (27.4%, 52/110), χ(2) = 8.790, P < 0.006 25. Among PTB patients, HLA-Cw04 had a significantly higher frequency in the SP group (20.7%, 13/35) than in the SN group (4.7%, 7/77), while HLA-Cw08 had a significantly lower frequency in the SP group (22.5%, 14/35) than in the SN group (54.4%, 61/77), χ(2) = 12.909, 16.732, both P < 0.006 25. CONCLUSIONS: HLA-Cw polymorphism is related to susceptibility to PTB. HLA-Cw08 may be one of the susceptible genes for PTB, and HLA-Cw04 and 08 may be related to MTB infectious status and clinical outcomes.

[Relationship between the expression of human leukocyte antigen-b in peripheral blood leukocytes and the differentiation and metastasis of gastric carcinoma].

OBJECTIVE: To investigate the relationship between the expression of host human leukocyte antigen-B mRNA (HLA-B mRNA) and HLA-B antigen in peripheral blood leukocytes (PBLs) and the differentiation and metastasis of gastric carcinoma (GC). METHODS: To design and screen specific primers of HLA-B gene independently, detect the expression of HLA-B mRNA from 30 GC patients by reverse transcription-PCR and compare with the HLA-B antigen expression measured by flow cytometry. RESULTS: The expression rate of PBL HLA-B mRNA from GC patients (23. 3% ) was very significantly lower than that of normals (87. 5% ) (P <0. 01) , especially concerning the poorly differentiated GC patients with lymph node metastasis (16. 0% ). Measured by flow cytometry, the expression percentage of HLA-B antigen of well-differentiated GC patients without lymph node metastasis was 88. 2% , an obviously decreasing tendency was showed in comparison with that in the normal group (98. 8% ) , although the difference was not significant (P = 0. 056) , and the expression percentage in poorly differentiated GC patients with lymph node metastasis(73. 3% )was declined significantly (P <0. 05). CONCLUSION: The expression of PBL HLA-B mRNA and HLA-B antigen in GC patients is decreased or lost, and correlated with differentiation and metastasis of the cancer. The expression of PBL HLA-B mRNA may more directly reflect its relationship with the tumor differentiation and metastasis than that of HLA-B antigen.