源于地衣的苏云金芽孢杆菌分离及PCR-RFLP分析

以非维管植物地衣为分离材料,采用热处理加抗生素及醋酸钠的方法,经常规形态学鉴定,分离到6株苏云金芽孢杆菌.为了解其生物学特性,分别对这6株菌株进行生理生化测定和cry基因的PCR-RFLP检测,结果显示: 6个菌株均含有cry1、cry1I 、cry2基因,所有菌株均不含cry3、cry4、cry5、cry6、cry8、cry10、cry11基因.初步确定6株菌株中含有5种 cry1亚类基因(cry1Ad,cry1Ba,cry1Cb,cry1Da,cry1Ea),1种cry2亚类基因cry2Ac,2种cry1I基因亚类(cry1Ia1、cry1Ib1),其中有2个菌株的PCR-RFLP图谱均出现特异性片段,推测可能存在新基因.     

Subtyping of type A influenza by sequencing the variable regions of HA gene specifically amplified with RT-PCR

The outbreak of a novel influenza A （H1N1） virus across the globe poses a threat to human health. It is of paramount importance to develop a rapid, reliable and inexpensive diagnostic procedure. Based on the bioinformatic information from public database, primers specific for influenza A virus surface protein haemagglutinin （HA） of several subtypes （including H1, H2, H3, H5, H7 and H9） were designed. Primer-specific PCR products were subiected to sequencing for accurately distinguishing H1 and H3 subtypes from others. This sequencing-based detection method will not only be applied to rapid detection and simultaneous subtype identification of new influenza A virus H1N1, but also provide the strategies to monitor other new types of influenza virus with explosive potential.     

基于双模式载波预付费电能表的自动抄表管理系统

针对高校学生公寓用电管理的特殊需求,给出了基于PL3201芯片的双模式载波预付费电能表设计方案,设计了一套双模式工作的载波预付费自动抄表管理系统,满足了高校学生公寓用电管理的特殊需求,提升了用电管理水平。     

铁观音茶多糖的酶法提取及脱蛋白工艺研究

采用纤维素酶水解方法提取铁观音茶多糖,并对其脱蛋白工艺进行了研究.酶法提取的正交实验结果表明,铁观音茶多糖的得率随酶用量和水解时间的增加而增大,随pH值和温度的升高先增后降,最佳的酶处理条件为:加酶量15 mg/g,pH=4.0,水解温度45℃以及水解时间90 min.比较了Sevag法、三氯醋酸法以及酶与三氯醋酸结合法对铁观音茶多糖的脱蛋白效果,结果表明,三氯醋酸法可以简单高效地去除蛋白质,而又不会造成多糖过多损失,4 mol/L三氯醋酸溶液的最佳使用量为2%(v/v).     

Effects of intermittent negative pressure on osteogenesis in human bone marrow-derived stroma cells

Objective: We investigated the effects of intermittent negative pressure on osteogenesis in human bone marrow-derived stroma cells (BMSCs) in vitro. Methods: BMSCs were isolated from adult marrow donated by a hip osteoarthritis patient with prosthetic replacement and cultured in vitro. The third passage cells were divided into negative pressure treatment group and control group. The treatment group was induced by negative pressure intermittently (pressure: 50 kPa, 30 min/times, and twice daily). The control was cultured in conventional condition. The osteogenesis of BMSCs was examined by phase-contrast microscopy, the determination of alkaline phosphatase (ALP) activities, and the immunohistochemistry of collagen type I. The mRNA expressions of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) in BMSCs were analyzed by real-time polymerase chain reaction (PCR). Results: BMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure, the activity of ALP increased significantly, and the expression of collagen type I was positive. In the treatment group, the mRNA expression of OPG increased significantly (P<0.05) and the mRNA expression of OPGL decreased significantly (P<0.05) after 2 weeks, compared with the control. Conclusion: Intermittent negative pressure could promote osteogenesis in human BMSCs in vitro.     

可实测FRP-混凝土最大粘结滑移量的双拉试件

探讨既有试件难以测出纤维复合材料(FRP)一混凝十最大粘结滑移量δu的原因,进而提出一种可稳妥实测δu的概念舣拉试件.并经实验研究、设计定型.结果表明,双拉试件的FRP-凝土界面局部范围内有较大滑移时,也不会发生界面整体剥离,从而克服了既有试件的缺点.其后又制作10个试件,探讨δu的确定方法和范围.结果显示,在本文实验条件下,实测δu为0.31～O.52 mm左右.     

大学数学实验课开设的探讨

数学实验课是一门新型的教学课程,它将数学知识、数学建模和数学软件有机结合,强化学生对数学理论的理解和应用,培养学生的创新能力和团队精神。针对该课程的开设,就大学数学实验课程开设的意义、课程的设置、数学软件的选取、教学原则等方面进行探讨,提出相应的建议和方法。     

Efficacy of anti-CD20 chimeric Fab’ fragment on proliferation of B lymphoma cells

The variable domain of heavy chain (V_H) and light chain (V_L) genes of anti-CD20 monoclonal antibody HI⁴⁷ were cloned from anti-CD20 ScFv expression vector pCANBTEcd20 by PCR and ligated into vector pYZF to construct chimeric anti-CD20 Fab’ fragment expression vector pYZFcd20. Chimeric anti-CD20 Fab’ fragment was expressed inE. coli 16C9 and purified by protein G affinity chromatography. Competitive inhibition assay showed that anti-CD20 Fab’ fragment inhibited binding of HI⁴⁷ to CD20 on the surface of Daudi cells. Results from MTT assay indicated that chimeric anti-CD20 Fab’ fragment inhibited the proliferation of Daudi cells, IC₅₀ = 69 μg/mL. Affinity of chimeric anti-CD20 Fab’ fragment was determined, K_a was about 8.9×10⁸ (mol/L)⁻¹.     

Investigation of novel zirconium based perovskite-type mixed conducting membranes for oxygen separation

A series of BaZr_0.2Co_0.8-xFe_xO_3-δ materials for oxygen separation were synthesized through a citric and EDTA acid combined complexing method, and their crystal structures, oxygen permeabilities, sintering and sealing abilities were investigated. The results showed that the cubic perovskite structure was formed for materials in the composition range investigated. Oxygen permeation flux and stability, as well as sintering and sealing abilities of the synthesized materials were increased or improved apparently due to the introduction of zirconium. For example, the oxygen permeation flux reached 0.8 mL/min·cm² when x = 0.2 or 0.3 at 950℃, and a stable time-related oxygen permeation flux was found for the BaZr_0.2Co_0.3Fe_0.5O_3-δ membrane at 800℃.     

HAsO_2在金电极上的阴极还原行为

采用环盘电极实验和交流阻抗技术等研究了ＨＡｓＱ_２在硫酸钠溶液（ｐＨ＝４．０）中在金电极上的阴极还原行为．结果表明,ＨＡｓＯ_２可以最终还原为 ＡｓＨ_３．整个还原过程可以分为两步：ＨＡｓＱ_２还原为金属Ａｓ和金属Ａｓ进一步还原成ＡｓＨ_３,还原产物ＡｓＨ_３在电极上的吸附较强,溶出性能较差．这两步还原过程在阻抗的复数平面图上呈现二个明显的电容弧,利用 ＥＱＵＩＶＣＲＴ软件对其进行计算机拟合,得到了对应的等效电路以及其中的反应电阻元件的数值．