生态维度 生活细度 生命深度——心灵成长引领作文真情实感“三级跳”

高中记叙文写作中的“真情实感”应与义务教育阶段有所不同，但教材并没有给出明确答案，许多语文教师也没能辟出可行之路。义务教育阶段记叙文写作的“真情实感”更强调写作的“真实性”与“真实感”，而高中记叙文写作必须在实践中启发学生的心灵成长，从“生态维度”“生活细度”“生命深度”三个层面循序渐进，将“真情实感”推向更高层次。

Expression of the Phycoerythrin Gene of Gracilaria lemaneiformis (Rhodophyta) in E. coli and Evaluation of the Bioactivity of Recombinant PE

Phycoerythrin （PE） is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E.coli BL21 to make two recombinant strains BEX （pGEX-PE） and BGL （pBGL）. PE expressing in BEX （pGEX-PE） was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bodies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX （pGEX-PE） cells were collected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indicated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein concentration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates were significantly higher than the negative control BL2 I（pGEX-4T） （P〈0.02）, and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mgmL^-1 BGL （pBGL） products, the scavenging effects of the supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates were stronger than that of negative control BL21（pGEX-4T）. However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially decreased hydroxyl radical scavenging activity was led by heating, the biological activity was still retained and conspicuous. This research showed that phycoerythrin protein expressing in E. coli has the potential medical and sanitarian value.

Methane production and small intestinal bacterial overgrowth in children living in a slum

AIM:To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests.METHODS:This transversal study included 85 children residing in a slum and 43 children from a private school,all aged between 6 and 10 years,in Osasco,Brazil.For characterization of the groups,data regarding the socioeconomic status and basic housing sanitary conditions were collected.Anthropometric data was obtained in children from both groups.All children completed the hydrogen(H 2) and methane(CH 4) breath test in order to assess small intestinal bacterial overgrowth(SIBO).SIBO was diagnosed when there was an increase in H 2 ≥ 20 ppm or CH 4 ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion.RESULTS:Children from the slum group had worse living conditions and lower nutritional indices than children from the private school.SIBO was found in 30.9%(26/84) of the children from the slum group and in 2.4%(1/41) from the private school group(P = 0.0007).Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school(P = 0.007).A higher concentration of hydrogen in the small intestine(P < 0.001) and in the colon(P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO.Methane production was observed in 63.1%(53/84) of the children from the slum group and in 19.5%(8/41) of the children from the private school group(P < 0.0001).Methane production was observed in 38/58(65.5%) of the children without SIBO and in 15/26(57.7%) of the children with SIBO from the slum.Colonic production of hydrogen was lower in methaneproducing children(P = 0.017).CONCLUSION:Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production.Hydrogen is a substrate for methane production in the colon.