报告基因在柞蚕幼虫体内表达的研究

利用柞蚕核型多角体病毒(AntheraeapernyiNuclearPolyhedrosisVirus,ApNPV)作为载体研究了报告基因(β-半乳糖苷酶基因)在柞蚕幼虫体内的表达。结果表明 :重组ApNPV能够使柞蚕幼虫产生典型的脓病病症 ,但不形成多角体。柞蚕核型多角体病毒作为表达载体能够使β-半乳糖苷酶基因在柞蚕幼虫体内得到高效表达。雌性幼虫个体的表达量为2.4×107u,雄性幼虫个体的表达量为1.8×107U;雌性个体较雄性个体在表达时相上早96h;对于同一个体 ,组织细胞中β-半乳糖苷酶的含量较血淋巴上清液中β-半乳糖苷酶的含量高。SDS-PAGE结果显示,所表达的β-半乳糖苷酶分子量为116kD。

Preparation of Mn substituted La-hexaaluminate catalysts by using supercritical drying

LaMnxAl12-xO19 catalysts were prepared from NH4OH and metal nitrates solutions. Supercritical drying (SCD) and conventional oven drying (CD) methods were used to extract the water in the hydrogel. The effects of drying methods on properties of the catalysts were investigated by means of TEM, N-2-adsorption, thermogravimetry (TG)-differential thermal analysis (DTA) and X-ray diffraction. SCD method is beneficial to maintain high surface area and improving catalytic activity for methane combustion of the catalyst. The specific surface area and pore volume of LaMn1Al11O19 catalyst prepared by SCD method are 28 m(2)/g and 0.23 cm(3)/g, respectively, and the ignition of methane could be carried out at 450degreesC. However, those of the CD catalyst prepared from the same precursor are 15 m(2)/g, 0.11 cm(3)/g and 530 degreesC, respectively. Suitable Mn content (0 less than or equal to x less than or equal to 2) could promote the formation of LaMnAl11O19 hexaaluminate, while further addition of Mn (2 less than or equal to x less than or equal to 6) cause the formation of LaMnO3. (C) 2003 Elsevier B.V All rights reserved.

不同放牧率下小花碱茅可溶性碳水化合物和氮素含量的变化

在东北松嫩草原上通过小区围栏放牧,对不同放牧率下小花碱茅可溶性碳水化合物和氮素含量的变化进行了分析。结果表明,小花碱茅在生长季初期茎基部的可溶性碳水化合物含量最低,随着季节推移逐渐增加;一定程度的放牧有利于牧草可溶性碳水化合物的提高,促进牧草再生。氮素含量在生长季初期最大,然后随季节推移逐渐降低;适当放牧能够刺激根对土壤中氮素的吸收,使其向地上部分转移,提高牧草的营养价值。

Application of uniform design and genetic algorithm in optimization of reversed-phase chromatographic separation

An optimization method based on uniform design in conjunction with genetic algorithm is described. According to the proposed method, the uniform design technique was applied to the design of starting experiments, which can reduce the number of experiments compared with traditional simultaneous methods, such as simplex. And genetic algorithm was used in optimization procedure, which can improve the rapidity of optimal procedure. The hierarchical chromatographic response function was modified to evaluate the separation equality of a chromatogram. An iterative procedure was adopted to search for the optimal condition to improve the accuracy of predicted retention and the quality of the chromatogram. The optimization procedure was tested in optimization of the chromatographic separation of 11 alkaloids in reversed-phase ion pair chromatography and satisfactory optimal result was obtained. (C) 2003 Elsevier B.V. All rights reserved.

The shape parameter of Liposomes and DNA-lipid complexes determined by viscometry utilizing small sample volumes

A minicapillary viscometer utilizing <0.5 ml of sample at a volume fraction of <0.1% is described. The calculated a/b of DPPC/DPPG multilamellar liposome was 1.14 as prolate ellipsoids and a/b of dioleoylpropyltrimethyl ammonium methylsulfate-DNA complex at a charge ratio of 4: 1 (+/-) was 3.7 as prolate ellipsoids or 4.9 as oblate ellipsoids. The deviation of shape from perfect sphere is thus expressed quantitatively in more than two significant figures. In these measurement, the necessary amount of DNA is <0.5 mg.

多环芳烃降解菌ZL5分离鉴定及其降解质粒

通过选择性富集培养 ,从辽河油田石油污染土壤中分离到一株多环芳烃 (PAHs)降解菌ZL5 .它能以菲和芘为唯一碳源生长 ,但是不能利用萘 .16SrDNA核苷酸序列分析结果表明 ,ZL5属于变形细菌α亚类中的鞘氨醇单胞菌属 .该菌株含有一个大小约为 6 0kb的质粒 .丝裂霉素C消除实验表明 ,随着质粒的丢失 ,菌株利用菲和芘的能力也丧失 .用电转化和氯化铷转化法分别将菌株ZL5的质粒导入大肠杆菌JM10 9和DH5α中 ,随着质粒的获得 ,这些转化子获得了降解菲和芘的能力 .本研究结果表明 ,鞘氨醇单胞菌ZL5降解PAHs的功能和质粒有关 .图 4参 16

An alternative approach to ascertain the rate-determining steps of TiO2 photoelectrocatalytic reaction by electrochemical impedance spectroscopy

In an attempt to ascertain the rate-determining steps (RDS) of TiO2 photoelectrocatalytic (PEC) reaction, the PEC oxidation of sulfosalicylic acid (SSA) solution in a TiO2-coated electrode reactor system was monitored by applying the electrochemical impedance spectroscopy (EIS) method. In the meantime, an EIS mathematical model was first established to theoretically simulate the PEC reaction. Based on the EIS model, the theoretical simulation indicates three typical reactions in a PEC oxidation process, which include the charge-transfer-dominated reaction, both the charge-transfer- and adsorption-dominated reaction, and the adsorption-dominated reaction. The experimental results of EIS measurement showed that there was only one arc/semicircle on the EIS plane display when the external bias applied was below 200 mV (vs SCE) in the SSA PEC degradation whereas there were two arcs/semicircles when the externally applied bias exceeded 200 mV (vs SCE). The experimental results have a good agreement with the model simulation. The EIS method in this study provides an easier way to determine the RDS in a PEC oxidation process, which would be helpful to better control the reaction in practice.

Synthesis and spectroscopic study of mesoporous aluminum methylphosphonate foam templated by dibutyl methylphosphonate

New types of templates and novel interactive mechanisms between template and framework are very important for creating porous materials. In this work, by using neutral dibutyl methylphosphonate as a template, an inorganic-organic hybrid mesoporous material, aluminum methylphosphonate, was prepared. The as-synthesized material was studied by P-31 magnetic angle spinning nuclear magnetic resonance (MAS NMR), Al-27 MAS NMR, C-13 CP/MAS, FT-IR spectroscopy, thermogravimetry (TG), differential thermal analysis (DTA), and transmission electron microscopy. After thermal treatment at 673 K and 10 mmHg for 2 h, hybrid mesoporous foam was obtained. The transformation process was investigated by FT-IR. TG-DTA results indicate that the methyl group bonded to the framework keeps intact up to 792 K under air and 823 K under nitrogen. The characterization results from nitrogen gas adsorption-desorption measurements show that the BET surface area and the Barrett-Joyner-Halenda desorption cumulative pore volume of the foam are 90 m(2) g(-1) and 0.32 cm(3) g(-1) respectively. (C) 2003 Elsevier Inc. All rights reserved.

耕地土壤交换性镁含量的空间变异性特征

利用地统计学和地理信息系统相结合的方法研究了沈阳市郊耕地土壤(0～20cm)交换性镁含量的空间变异性特征 ,绘制了交换性镁含量的空间分布图。结果表明 :土壤交换性镁含量符合正态分布 ,变异函数的最佳理论模型为球状模型 ,交换性镁含量具有中等的空间相关性(C0 与C0+C比值为55.0 %) ,但空间自相关距离较大(73.1km) ,影响其空间变异的结构性因子主要是成土母质、河流走向以及土壤类型。

Improvement of Pt catalyst for soot oxidation using mixed oxide as a support

Catalytic activity of Pt catalysts for soot oxidation was studied using temperature programmed reactions. The activity of Pt loaded over TiO2-SiO2 (Pt/TiO2-SiO2) showed higher activity than other Pt/MOx systems (MOx = TiO2, ZrO2, SiO2, Al2O3. TiO2-ZrO2. TiO2-Al2O3, ZrO2-SiO2, ZrO2-Al2O3, SiO2-Al2O3). The activity was highest when the molar ratio of TiO2/(TiO2 + SiO2) ranged from 0.4 to 0.7. The effect of pretreatment with a gas containing low SO2 concentrations on the activity was compared for Pt/SiO2, Pt/TiO2 and Pt/TiO2-SiO2. In the case of Pt/TiO2-SiO2, the activity was markedly promoted by the pretreatment whereas no variation in the activity was observed for Pt/SiO2. The difference in the behavior towards the SO, pretreatment was attributed to property difference in the supports for sulfate accumulation. The high activity of Pt/TiO2-SiO2 was also confirmed under practical conditions with a diesel engine exhaust using a catalyst-supported diesel particulate filter (DPF). (C) 2003 Elsevier Science B.V. All rights reserved.

Capillary electrochromatographic separation of enantiomers on chemically bonded type of cellulose derivative chiral stationary phases with a positively charged spacer

Positively charged chiral stationary phases (CSPs) were prepared for capillary electrochromatography (CEC) separation of enantiomers by chemically immobilizing cellulose derivatives onto diethylenetriaminopropylated silica (DEAPS) with tolylene-2,4-diisocyanate (TDI) as a spacer reagent. Anodic electroosmotic mobility was observed in both nonaqueous and aqueous mobile phases due to the positively charged amines on the surface of the prepared CSPs. For comparison, the traditionally used 3-aminopropyl silica (APS) was also adopted as the base material instead of DEAPS to prepare CSP. It was observed that the EOF on the DEAPS-based CSP was 18%-60% higher than that on the APS-based CSP under nonaqueous mobile phase conditions. Separation of enantiomers in CEC was performed on the positively charged CSPs with the nonaqueous mobile phases of pure ethanol or mixture of hexane-alcohol and the aqueous phases of acetonitrile-water or 95% ethanol. Fast separation of enantiomers was achieved on the newly prepared CSPs.

光合细菌及其在化工有机废水处理方面的应用

光合细菌作为一类古老的细菌类群 ,已经在众多领域得到应用。利用光合细菌处理有机废水具有处理有机负荷高、占地面积小、便于管理、能耗低、投资费用少、菌体可以回收利用等优点 ,已经引起人们的重视。对光合细菌在处理化工有机废水方面的研究和应用进行了综述 ,指出光合细菌处理法的优缺点和发展趋势 ,认为光合细菌在有机废水处理方面的应用前景广阔