Research Progress of Polysaccharides of Portulaca oleracea

本文就近年来国内外有关马齿苋多糖的提取、化学结构、含量测定及药理作用等方面的研究现状进行了概述,并指出马齿苋多糖是一种极具开发潜力和开发价值的天然功能食品,在预防多种疾病的发生及延缓并发症的发展方面有着广阔的应用前景。This paper briefly introduced the extraction, constitution, determination and pharmacology of the polysaccharides of Portulace oleracea L. in the last decade. The polysaccharides of Portulace oleracea L. is a natural functional food with high development potentials and values and will be widely used to prevent various diseases.江西省教育厅科学技术研究项目(赣教技字[2007]285号

锂离子电池低温性能改善研究进展

锂离子电池因其能量密度高,循环寿命长等优点已成为新型动力电池领域的研究热点,但其温度特性尤其是低温性能较差制约着锂离子电池的进一步使用.本文综述了锂离子电池低温性能的研究进展,系统地分析了锂离子电池低温性能的主要限制因素.从正极、电解液、负极三个方面讨论了近年来研究者们提高电池低温性能的改性方法.并对提高锂离子电池低温性能的发展方向进行了展望.国家重点研发计划(No.2018YFB010400);;福建省高校产学合作项目(No.2018H6020)资

Screening Antitumor Effect of Active Constituents from Portulaca oleracea L. in vitro and in vivo

目的观察马齿苋活性成分对人肺腺癌细胞系(A-549 CEll)、人喉表皮样癌细胞系(HEP-2 CEll)、人宫颈癌细胞系(HElA CEll)和人恶性胚胎横纹肌瘤细胞系(rd CEll)生长的影响。方法体外培养条件下用不同浓度的马齿苋活性成分处理4种癌细胞,通过溴化二甲噻唑二苯四氮唑(MTT)试验法测定癌细胞的增殖;同时处理S180荷瘤小鼠,观察荷瘤小鼠的体重、瘤重、死亡率和抑瘤率。结果马齿苋生物碱对离体培养的A-549肺癌细胞、HElA细胞和HEP-2细胞的增殖均具有明显抑制作用,马齿苋多糖对HElA细胞有较强的抑制作用,马齿苋脂肪酸对HEP-2细胞有一定的抑制作用,马齿苋黄酮对rd细胞有很强的抑制作用,并存在浓度剂量效应,高浓度抑制作用强。结论马齿苋活性成分能选择性地杀伤癌细胞,有进一步研究的潜在价值。Objective To observe the effects of the active constituents from Portulaca oleracea L.on the proliferation of four human tumor cell lines.Methods The anti-proliferation activities of active constituents from Portulaca oleracea L.upon A549 cell,Hela cells,Hep-2 cell and RD cell were analyzed by MTT in vitro.Body weigt,tumor weigt,inhibition rate and death rate of these active constituents from Portulaca oleracea L.on the transplanted tumor cells of Sarcinoma 180 were observed in mice.Results Raw screening of the four compounds by MTT indicated polysaccharides,flavonoids,alkaloids and polyunsaturated fatty acid exerted obvious suppression on the proliferation of tumor cell lines in a dose dependent manner,respectively.The experiments in vivo indicated that the four active constituents had certain inhibition against the cells of implanted tumor ascites Sarcinoma 180.Conclusion The active constituents from Portulaca oleracea L.have selective cytotoxicity to the tumor cells and is worthy of further investigation.江西省教育厅科技项目(No.〔2007〕285);江西科技师范学院大学生创业科研训练项目(No.[2007]-178

Screening of α-glucosidase Inhibitors in Active Constituents from Portulaca oleracea L.

[目的]观察马齿苋活性成分对兔小肠黏膜α-葡萄糖苷酶活性的影响,筛选α-葡萄糖苷酶抑制剂。[方法]提取分离马齿苋活性成分,在体外建立微量酶反应体系,PnPg作为底物,以阿卡波糖为参照,检测马齿苋活性成分对α-葡萄糖苷酶活性的影响。[结果]马齿苋总提取液、粗多糖和总生物碱对α-葡萄糖苷酶具有明显抑制作用,抑制效果接近于阿卡波糖,不饱和脂肪酸和总黄酮无抑制作用。[结论]马齿苋防治糖尿病的主要成分是生物碱和多糖,可能具有阿卡波糖样的降糖机制。[Objective] The research aimed to observe the effects of active constituents from Portulaca oleracea L.on α-glucosidase activity in intestine mucous to screen α-glucosidase inhibitors.[Method] The active constituents were extracted from Portulaca oleracea L..The trace enzyme reaction system was constructed in vitro.Taking the pNPG as substrate,and acarbose as control,the effects of the active constituents from Portulaca oleracea L.on α-glucosidase activity.[Result] Total extraction,alkaloids and polysaccharides from Portulaca oleracea L.could obviously inhibit α-glucosidase activity,but polyunsaturated fatty acid and flavonoids had no inhibition.[Conclusion] The main active constituents are alkaloids and polysaccharides from Portulaca oleracea L.for preventing diabetes,and the hypoglycemic mechanism is similar to acarbose.江西省教育厅科技项目(赣教技字〔2007〕285号);江西科技师范学院人才创新基金项目(2005

基于线粒体控制区序列的黄河上游厚唇裸重唇鱼种群遗传结构

采集黄河上游厚唇裸重唇鱼(Gymnodiptychus pachycheilus)甘肃玛曲群体,测定其线粒体DNA控制区序列,并从GenBank中下载青海玛多和贵德等3地2个群体的同源序列,分析该物种的遗传多样性、遗传结构及其演化历史。从81条729 bp序列中,检测到26个变异位点(占3.57%),碱基序列总的单倍型多样性为0.844,核苷酸多样性为0.0054,界定了34个单倍型,有1个广布单倍型H2,占所有样品的38.27%。单倍型网络图图显示单倍型没有明显的亲缘地理格局,H2处于中心,呈星状发散,系统发育分析没有显示出单倍型与地理位置的对应关系。AMOVA分析显示变异主要来自地理区内群体间,歧点分布和中性检测显示厚唇裸重唇鱼近期经历了种群扩张。分析表明黄河上游3地种厚唇裸重唇鱼种群未出现分化,建议应作为一个整体进行保护

Research Progresses in Improvement for Low Temperature Performance of Lithium-Ion Batteries

锂离子电池因其能量密度高，循环寿命长等优点已成为新型动力电池领域的研究热点，但其温度特性尤其是低温性能较差制约着锂离子电池的进一步使用. 本文综述了锂离子电池低温性能的研究进展，系统地分析了锂离子电池低温性能的主要限制因素. 从正极、电解液、负极三个方面讨论了近年来研究者们提高电池低温性能的改性方法. 并对提高锂离子电池低温性能的发展方向进行了展望.Lithium-ion batteries (LIBs) have become a new research hotspot due to their high energy density and long service life. However, the temperature characteristics, especially the poor performance at low temperatures, have seriously limited their wider applications. In this report, the research progresses in the low temperature performance of LIBs are reviewed. The main existing limitations of LIBs at low temperatures were systematically analyzed, and followed by discussion on the recent improvements in low temperature performances by developing novel cathode, electrolyte, and anode materials. The developments for improving the low temperature performance of LIBs are prospected. The three most important factors that influence the low temperature electrochemical performance of LIBs are as follows: 1) a reduced ion conductivity of the electrolyte and solid electrolyte interface (SEI) film formed on the electrode/electrolyte interface; 2) increased charge-transfer resistances at both the cathode and anode electrolyte- electrode interfaces; 3) slow lithium diffusion in the electrodes. The above three points lead to high polarization and lithium deposition, which may cause problems in terms of performance, reliability and safety of the cell. The key point is to provide expedite paths for the transport of lithium ions and electrons at low temperatures. All the influential aspects, such as cathode, electrolyte,and anode, should be considered to improve the low temperature performance of LIBs. The low temperature electrolyte can be obtained by adjusting the relative compositions, and species of the solvent, salt, and additive. The conductivity of electrolyte can be improved by adding low melting point cosolvents and salts. In addition, use of electrolyte additives forming low impedance interface film is one of the most economic and effective methods to improve the low temperature performance. And the structure of electrode materials can be optimized by doping, coating and decreasing the particle size, which can ensure sufficient conductivity and shorten diffusion path length for lithium ions and electrons. Managing the electrolyte and developing electrodes are efficient methods to improve the low temperature performance. Future studies should be focused on achieving high performance lithium-ion battery materials.国家重点研发计划（No. 2018YFB010400）和福建省高校产学合作项目（No. 2018H6020）资助作者联系地址：1.多氟多化工股份有限公司，河南 焦作 454150; 2. 厦门大学化学化工学院/能源学院，福建 厦门 361005; 3. 多氟多(焦作)新能源科技有限公司，河南 焦作454150Author's Address: 1. Do-fluoride Chemicals Co., Ltd, Jiaozuo 454150, Henan, China; 2. College of Chemistry and Chemical Engineering/College of energy, Xiamen University, Xiamen 361005, Fujian China 3. Do-Fluoride Jiaozuo New Energy Technology CO., Ltd, Jiaozuo 454150, Henan, China通讯作者E-mail：[email protected]; yyang@xmu. edu. c

2005～2014年CERN野外台站气象观测场土壤含水量数据集

土壤水分是影响陆地–大气边界层能量和物质传输的重要因子。土壤水分含量是中国生态系统研究网络(CERN)陆地生态系统水环境长期定位观测的重要指标。截至2014年,CERN全国范围内包括农田、森林、草地、荒漠与湿地等生态类型的34个陆地生态系统台站,依据陆地水环境观测规范、质量保证与质量控制规范,设立观测样地,并开展土壤含水量的长期定位观测与数据汇交及质控工作。CERN水分分中心选取了这34个台站2005～2014年气象观测场的土壤含水量长期监测数据,通过进一步统一规范数据格式,形成了全国范围内较长时间序列的公开共享数据集,为土壤含水量时空动态的遥感反演、模型估算验证提供地面实测数据支撑