The Production-Oriented Approach(POA)has been proposed as a remedy for overcoming the problem of input-output separation in the traditional text-centered teaching and learning paradigm in tertiary education in China.T...The Production-Oriented Approach(POA)has been proposed as a remedy for overcoming the problem of input-output separation in the traditional text-centered teaching and learning paradigm in tertiary education in China.This two-week quasi-experimental study investigated the effect of the POA,compared with the traditional text-centered Intensive Reading Approach(IRA),on college students’L2 writing performance in terms of overall quality of the writing and its components of language,idea,and discourse structure.Data included writing samples of both experimental and control groups before and after classroom instruction and the results of a language achievement test on mastery of target language forms predicating students’language use in writing.The results showed that:1)no significant difference was found between the two groups either in the overall quality or in the“idea”and“structure”of the written texts;2)the experimental group outperformed the control group with respect to language use,in terms of both language quality and the frequency of target language use.These results indicated that the POA might have an advantage over the IRA in facilitating learners’writing development.展开更多
AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Singl...AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Single-cell Fas mRNA expression in H2O2-exposed L02 hepatocytes with or without treatment of Rxa,an extract from an anti-peroxidant, Radix Salviae Miltiorrhizae,was determined by all-cell patch clamp and single-cell reverse transcriptase polymerase chain reaction (RT-PCR). Transient calcium influx change ([Ca2+]i) in the cells was evaluated with all-cell patch clamp micro-fluorescence single-cytosolic free Ca2+ concentration technique. Fas protein expression, early apoptotic index (annexin-V+) and cell membrane change inthe cells were evaluated by immunohistochemistry, flow cytometry (FCM) and scan electron microscopy respectively.RESULTS: In cells exposed to H2O2 for 2 h, the specific lane for Fas mRNA was vivid on electrophoresis, with increased Fas protein expression, [Ca2+]i (from 143.66±34.21 to 1115.28±227.16), annexin-V+ index (from 4.00±0.79 to 16.18±0.72) and membrane vesicle formation. However, in cells exposed to H2O2 but pre-treated with Rxa, there was no increase in Fas mRNA or protein expression and [Ca2+]i (103.56±28.92). Annexin-V+ index (8.92±1.44) was lower than the controls (P＜0.01), and the cell membrane was intact.CONCLUSION: H2O2 induces apoptosis of L02 cells by increasing cytosolic [Ca2+]i, and inducing Fas mRNA and protein expression. Rxa protects the L02 cells from apoptosis through anti-peroxidation, inhibition of calcium overloading and prevention of the activation of cytosolic Fas signal pathway.展开更多
文摘The Production-Oriented Approach(POA)has been proposed as a remedy for overcoming the problem of input-output separation in the traditional text-centered teaching and learning paradigm in tertiary education in China.This two-week quasi-experimental study investigated the effect of the POA,compared with the traditional text-centered Intensive Reading Approach(IRA),on college students’L2 writing performance in terms of overall quality of the writing and its components of language,idea,and discourse structure.Data included writing samples of both experimental and control groups before and after classroom instruction and the results of a language achievement test on mastery of target language forms predicating students’language use in writing.The results showed that:1)no significant difference was found between the two groups either in the overall quality or in the“idea”and“structure”of the written texts;2)the experimental group outperformed the control group with respect to language use,in terms of both language quality and the frequency of target language use.These results indicated that the POA might have an advantage over the IRA in facilitating learners’writing development.
基金Supported by National Natural Science Fundation of China, No.39770938Whole Army Medical Scientific Research Task during the Fifteen the Five-year Plan, No. 01MA040
文摘AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Single-cell Fas mRNA expression in H2O2-exposed L02 hepatocytes with or without treatment of Rxa,an extract from an anti-peroxidant, Radix Salviae Miltiorrhizae,was determined by all-cell patch clamp and single-cell reverse transcriptase polymerase chain reaction (RT-PCR). Transient calcium influx change ([Ca2+]i) in the cells was evaluated with all-cell patch clamp micro-fluorescence single-cytosolic free Ca2+ concentration technique. Fas protein expression, early apoptotic index (annexin-V+) and cell membrane change inthe cells were evaluated by immunohistochemistry, flow cytometry (FCM) and scan electron microscopy respectively.RESULTS: In cells exposed to H2O2 for 2 h, the specific lane for Fas mRNA was vivid on electrophoresis, with increased Fas protein expression, [Ca2+]i (from 143.66±34.21 to 1115.28±227.16), annexin-V+ index (from 4.00±0.79 to 16.18±0.72) and membrane vesicle formation. However, in cells exposed to H2O2 but pre-treated with Rxa, there was no increase in Fas mRNA or protein expression and [Ca2+]i (103.56±28.92). Annexin-V+ index (8.92±1.44) was lower than the controls (P＜0.01), and the cell membrane was intact.CONCLUSION: H2O2 induces apoptosis of L02 cells by increasing cytosolic [Ca2+]i, and inducing Fas mRNA and protein expression. Rxa protects the L02 cells from apoptosis through anti-peroxidation, inhibition of calcium overloading and prevention of the activation of cytosolic Fas signal pathway.
