功能化石墨烯对海洋环境细菌群落结构及生长的影响

功能化石墨烯因其优异的导电、传热和机械性能，应用前景广阔。为了解功能化石墨烯对海洋环境可能的生态毒性效应，将功能化石墨烯分别加入近岸海水（终质量浓度50 mg/L）和沉积物（终质量分数50 mg/kg）中，通过模拟海洋环境对样品培养2周，并采用DNA高通量测序技术分析功能化石墨烯对海洋细菌群落结构的影响。结果表明功能化石墨烯对两种海洋环境来源的细菌物种组成均有明显影响，但影响效果不同：暴露于功能化石墨烯后，海水中细菌的物种多样性和丰度降低，而沉积物中细菌的物种多样性和丰度升高，这可能是功能化石墨烯在海水和海洋沉积物中分散、吸附和团聚等环境行为存在差异所致。然而，无论在哪种环境来源的处理组中，功能化石墨烯的存在均对光合细菌的生长起促进作用。上述结果可为功能化石墨烯的海洋生态安全性评估提供参考。厦门市海洋经济创新发展示范项目(16PZP001SF16);;\n国家微生物资源平台项目(NIMR-2019-9);;\n国家海洋局海洋生物遗传资源重点实验室开放研究基金(HY201505

Selectivity of biopolymer membranes using HepG2 cells

Bioartificial liver (BAL) system has emerged as an alternative treatment to bridge acute liver failure to either liver transplantation or liver regeneration. One of the main reasons that the efficacy of the current BAL systems was not convincing in clinical trials is attributed to the lack of friendly interface between the membrane and the hepatocytes in liver bioreactor, the core unit of BAL system. Here, we systematically compared the biological responses of hepatosarcoma HepG2 cells seeded on eight, commercially available biocompatible membranes made of acetyl cellulose&ndash;nitrocellulose mixed cellulose (CA&ndash;NC), acetyl cellulose (CA), nylon (JN), polypropylene (PP), nitrocellulose (NC), polyvinylidene fluoride (PVDF), polycarbonate (PC) and polytetrafluoroethylene (PTFE). Physicochemical analysis and mechanical tests indicated that CA, JN and PP membranes yield high adhesivity and reasonable compressive and/or tensile features with friendly surface topography for cell seeding. Cells prefer to adhere on CA, JN, PP or PTFE membranes with high proliferation rate in spheriod-like shape. Actin, albumin and cytokeratin 18 expressions are favorable for cells on CA or PP membrane, whereas protein filtration is consistent among all the eight membranes. These results further the understandings of cell growth, morphology and spreading, as well as protein filtration on distinct membranes in designing a liver bioreactor.</p

不同水分处理下农田黑土水分特征

采用田间定位试验,利用中子仪原位监测土壤储水量的方法,研究3个水分处理下农田土壤水分特征。结果表明:受长期不同水分处理的影响,适宜水分处理0—110 cm土壤储水量最高,其次为自然降水处理,分别比干旱处理增加了23.4%和12.9%;在大豆生育期内,各水分处理土壤储水量的季节性变化均呈"减小—增加—减小—增加"的趋势,与大豆生育期内降雨分布密切相关;各处理大豆耗水量表现为适宜水分处理>自然降水处理>干旱处理,其值分别为459.4、420.3、326.4 mm;不同时段大豆耗水量表现为在无控水影响的时期(2008-05-01—2008-06-15)大豆耗水量处理间差异较小,而在控水时期差异较明显;从进水量与耗水量的比值可以看出,黑土调节土壤水分的能力较强;干旱处理、自然降水处理和适宜水分处理水分利用效率分别为3.9、4.8和5.4kg.hm-2.mm-1,表明一般年份灌溉能够提高水分利用效率