Preparation of magnetic porous terpolymer and its application in cellulase immobilization

In this work, a series of porous terpolymers with degrees of crosslinking at 30–65% were synthesized by suspension polymerization. Fe₃O₄ nanoparticles were used to modify the porous terpolymer with degree of crosslinking at 30%. The resulting terpolymers with mean pore size of 10–30 nm were used as supports for immobilization of cellulases through covalent bondings. The Fourier transform infrared spectroscopy and thermal gravity analysis measurements demonstrated that cellulases were immobilized onto the porous terpolymers. The effects of pH and temperature on enzyme activity were investigated in acetate buffer medium by hydrolysis of sodium carboxymethyl celluloses. The reusability of immobilized cellulases was also investigated. The result showed that immobilized cellulases exhibited higher residual activities and enzyme activities than free cellulases in wide ranges of pH and temperature. We also found that the reusability of cellulases immobilized on terpolymers with magnetism was better than that of cellulases immobilized on terpolymers without magnetism. POLYM. ENG. SCI., 55:1039–1045, 2015. © 2014 Society of Plastics Engineers     

Non-isothermal crystallization kinetics of polypropylene and hyperbranched polyester blends☆

Polypropylene (PP) with different contents of the second generation hyperbranched polyester (HBP) is prepared by melt blending method. The non-isothermal crystallization kinetics of PP and PP/HBP blend...     

大型机械设备融资租赁应用研究

大型机械设备是许多企业生产经营的核心,融资租赁作为一种新型的金融工具,可实现融资、融物的有机结合,逐渐成为企业添置大型设备的主流方式之一。首先,分析了融资租赁的特点;其次,分析了融资租赁应用过程中存在的风险;最后,提出了企业应用融资租赁的对策建议。     

综合性考核在本科《药理学》课程中的应用

为了培养学生自主学习能力、提升药理学学习兴趣和信心,在本科药学专业中推行综合性考核方法,内容包括:学生考勤、小测验、病例分析、实践技能、期末考试。对药理学考试成绩进行比较分析。结果综合性考核方式学生及格率、平均分均较传统考核方式提高,学生对这一考核方法接受度较高,为其进一步的推广奠定了基础。     

土方调配优化中的问题及其解决方法

在土方调配中,对土方调配的求解方法通常采用线性规划法中的"表上作业法"进行改进,采用"表上两侧夹逼作业法"。这种方法可以提高工作效率,减少检验等步骤,可一次性得到更为准确、高效的最优解。     

基于大数据的城市交通态势推演与综合评估关键技术及应用

城市交通态势推演和评估技术是城市交通治理的核心量化分析技术.随着城市交通治理综合化、精细化和智能化要求的提高,传统依托小样本数据调查与分析,建立集计经验模型进行多方案比选评估的方法和技术,已难以适应新时期城市交通治理要求.本项目历时十余年,在国家自然科学基金等国家级、省部级课题支持下,突破了基于多源大数据的个体出行活动链全过程全方式融合感知、城市交通演化态势可靠推演与敏捷预测、城市交通精细化治理综合评估等关键技术,建立了面向城市交通精细化治理的个体出行活动链模型和大规模路网实时在线推演模型,构建了大数据综合评估体系,支撑了城市交通精细化治理科学量化分析与评估.项目应用超过1000个项目,推广至成都、重庆、苏州、湛江、南昌、长春、兰州等100多座城市,影响了全国约2亿人的交通出行.     

游船旅游活动对洱海水环境的影响分析

根据洱海现有游船的特点和数量,基于游船产生的含油废水、固体废弃物、生活污水,分析了游船旅游活动对洱海环境的影响及其特点,并在此基础上提出了洱海游船污染防治措施。     

A New and Practical Synthetic Method for the Synthesis of 6-O-Methyl-scutellarein: One Metabolite of Scutellarin in Vivo

Scutellarin (1) has been used for the treatment of angina pectoris, cerebral infarction and coronary heart disease with a large market share in China. Pharmacokinetic studies on scutellarin showed that scutellarin (1) is readily converted into its metabolites in vivo. In this paper, a new and practical synthetic method for the synthesis of 6-O-methyl-scutellarein (3) (one metabolite of scutellarin in vivo) is reported. The benzyl bromide was firstly used to selectively replace the acetyl group at C-7 in 7, and was then used to protect the hydroxy groups at C-4'' in 10, 6-O-methyl-scutellarein (3) is obtained in high yield through these methods.     

Unveiling the Mode of Action of Two Antibacterial Tanshinone Derivatives

In this study, 2-(N-pyrrolidine-alkyl) tanshinones bearing pyrrolidine groups were synthesized and the antibacterial mechanism was explored. These derivatives selectively elicited antibacterial activity against Gram-positive bacteria. Moreover, their antibacterial activities were time-, concentration-dependent and persistent. It appeared that Fenton-mediated hydroxyl radicals were involved, and the disruption of cell membranes was observed. This study indicates that 2-(N-pyrrolidine-alkyl) tanshinones might be potential candidates as antibacterial agents.     

Ovine Hair Follicle Stem Cells Derived from Single Vibrissae Reconstitute Haired Skin

Hair follicle stem cells (HFSCs) possess fascinating self-renewal capacity and multipotency, which play important roles in mammalian hair growth and skin wound repair. Although HFSCs from other mammalian species have been obtained, the characteristics of ovine HFSCs, as well as the methods to isolate them have not been well addressed. Here, we report an efficient strategy to obtain multipotent ovine HFSCs. Through microdissection and organ culture, we obtained keratinocytes that grew from the bulge area of vibrissa hair follicles, and even abundant keratinocytes were harvested from a single hair follicle. These bulge-derived keratinocytes are highly positive for Krt15, Krt14, Tp63, Krt19 and Itga6; in addition to their strong proliferation abilities in vitro, these keratinocytes formed new epidermis, hair follicles and sebaceous glands in skin reconstitution experiments, showing that these are HFSCs from the bulge outer root sheath. Taken together, we developed an efficient in vitro system to enrich ovine HFSCs, providing enough HFSCs for the investigations about the ovine hair cycle, aiming to promote wool production in the future.