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A 4-factorial (water temperature,salinity,nitrogen,and phosphorus) experiment was designed to study the niche characteristics of four common microalgae communities in prawn-aquaculture pond. The results showed that the niche breadth was the greatest for Cryptomonas erosa in temperature and salinity resources (0.980 and 0.988,respectively) and for Niztzschia closterium in nitrogen and phosphorus resources (0.990),but the smallest for Chlorella pyrenoidosa in all test resources,with an average value of 0.926. As for niche overlap,it was the smallest for C. erosa and C. pyrenoidosa in temperature and salinity resources (0.809 and 0.702,respectively) and for C. erosa and N. closterium in nitrogen and phosphorus resources (0.829),but the greatest for C. pyrenoidosa and Nannichloropsis oculata in temperature,salinity,and nitrogen and phosphorus resources,with the values being 0.986,0.974 and 0.989,respectively. All of these suggested that in prawn-aquaculture pond,C. erosa could be bred with any other three of the microalgae communities,while N. oculata and C. pyrenoidosa should not be bred together for their obvious competition on the resources. [ABSTRACT FROM AUTHOR]

Objective: To investigate the expression of CD95 and special marker for activation of peripheral blood lymphocytes in patients with hand foot and mouth disease (HFMD) and its significance., Methods: Immunofluorescent two-color flow cytometry was used to study the expression of CD95 and HLA-DR on lymphocytes in 58 patients with HFMD and 34 normal controls., Results: Expression of CD3+ T cells was significantly lower in patients (63.82 +/- 7.74)% than that in controls (P < 0.001), meanwhile the expression of CD4+ T cells was (34.29 +/- 7.33)%, significantly lower than that of the controls (P < 0.005). The percentage of lymphocytes expressing HLA-DR in patients was (23.77 +/- 5.78)%, significantly higher than that of the controls (P < 0.005). Significant difference was observed in the expression of HLA- DR on CD8+ T cells in patients (1.34 +/- 1.12)% as compared with controls (P < 0.005). No significant difference in the expression of CD95 on lymphocytes was observed between patients and the controls (P > 0.05)., Conclusion: The findings support that cellular immunodeficiency exists in patients and that lymphocytes were abnormally activated in the patients. The activation of peripheral blood T lymphocytes in patients mainly involves CD8 subset and it may play an important role in the immune response to antiviral infection.

Objective: To study the application of decision tree in the research of anemia among rural children., Methods: In the Enterprise Miner module of software SAS 8.2, 3000 observations were sampled from database and the decision tree model was built. The model using decision tree of CART bases on Gini impurity index., Results: The misclassification rate of decision tree model was, training set 21.2%, validation set 21.9%. The Root ASE of decision tree model was, training set 0.399, validation set 0.404. The area under the ROC curve was larger than the reference line. The diagnostic chart showed that the corresponding percentage was higher than the other. The decision tree model selected 9 important factors and ranked them by their power, among which mother of anemia (1.00) was the most important factor. Others were children's age (0.75), time of ablactation (0.53), mother's age (0.32), the time of egg supplementation (0.26), category of the project county (0.26), the time of milk supplementation (0.16), number of people in the family (0.13), the education status of the mother (0.12). Decision tree produced simple and easy rules that might be used to classify and predict in the same research., Conclusion: Decision tree could screen out the important factors of anemia and identify the cutting-points for factors. With the wide application of decision tree, it would exhibit important application values in the research of the rural children health care.

A pPICZ alpha1 vector was reconstructed with pPICZ alpha vector and PCR product of His4-Kan sequence from pPIC9K vector. The sequence encoding human brain-derived neurotrophic factor (hBDNF) was inserted into pPICZ alpha1. The expression vectors carrying 1, 2, 3, 6 copies of expression cassettes were constructed and transformed into Pichia pastoris GS115 respectively. The transformants were screened with G418/Zeocin and induced by 0.5% methanol, and the results of SDS-PAGE confirmed that the expression protein was about 14 kD and the percentage of the protein was about 20% of the total secreted protein. ELISA and Western blot analysis demonstrated that the protein could be specifically combined with chicken antibodies to human-BDNF.

Objective: To explore the point mutation in hepatitis B virus polymerase (HBV P) gene in HBV-infected patients resistant to lamivudine., Methods: HBV P gene was amplified by PCR and the products was sequenced to analyze the YMDD mutation. Then the variants were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with the following restriction enzymes: Fok I, Ssp I, Alw441 and were separated by 8.0% polyacrylamide gel electrophoresis., Results: Comparing with the sequences of standard HBV genome, there were 16 patients with G743C mutation and 1 patient with G743A mutation, and the codon ATG turned to ATC and ATA, YMDD motif changed into YIDD. But this kind of YIDD mutation was not proved by PCR-RFLP assay in the 17 patients., Conclusions: The G743C and G743A mutations in HBV P gene, resulting in YMDD motif changed into YIDD, are detected only by direct sequencing, not by PCR-RFLP. The new kind of G743C and G743A point mutations in HBV P gene is important for the detection of HBV P gene YMDD mutation.

Objective: To study the types and emergence time of YMDD motif mutation in hepatitis B virus (HBV) polymerase gene during lamivudine treatment., Methods: The serum samples were collected from 33 patients with HBV DNA rebounding and 2 non-responders after at least one year lamivudine treatment. HBV polymerase gene was amplificated by PCR, then the products were detected by restriction fragment length polymorphism (RFLP) and by direct sequence analysis., Results: The variants with YMDD mutation were 14 out of the 35 patients. Mutation patterns detected in these patients included four YIDD, six YVDD, three YI/VDD and one YI/MDD. The mean emergence time of YMDD variants was 11.07+/-3.65 months after the treatment, and the earliest one and the latest one occurred 5 months and 17 months after the treatment respectively. The emergence times of YIDD, YVDD, YI/VDD were (10.00 +/- 1.41) months, (11.67 +/- 4.41) months and (13.33 +/- 3.31) months respectively, which had no statistical significance (F = 0.543, P < 0.05). Three patients treated with lamivudine 200 mg every day after the mutation were followed up for 6 months, whose HBV variants had not vanished., Conclusions: There are many kinds of HBV variants after lamivudine treatment, including YIDD, YVDD, YI/VDD and YI/MDD. The emergence time of variants is quite variable between different types and the mean time is (11.07 +/- 3.65) months after treatment, and there is no relationship between the type of YMDD mutation and the time of lamivudine administration.