赤豆β-半乳糖苷酶固定化及其性质研究

用阳离子修饰的 Sephadex G- 1 0 0 ,经 Br CN活化 ,将部分纯化的赤豆 β-半乳糖苷酶通过吸附和共价交联法固定化。固定化载体表现出较高的蛋白载量和酶活性收率。固定化酶活性收率达 6 5 %。动力学性质研究表明 ,固定化酶酸碱稳定性、热稳定性、存储稳定性和使用稳定性都比游离酶好。

Relationship between Living Rate of Bud and Emergence Rate of Ratoon Rice and Characteristics of the First Cropping Mid-season Hybrid Rice

[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.

Study of the Chemical Flooding Effect in Gao-63 Reservoir

This article is aimed to discuss the impact of using two different kinds of surfactant in enhancing oil recovery in heterogeneous reservoirs. With the background of Jidong oilfield, Rui Feng surfactant which could reach ultra-low interracial tension and combination surfactant RZ-JD80 with strong emulsifying property are chosen to do oil displacement and profile control-oil displacement experiment in homogeneous core and heterogeneous core respectively. The experiment is aimed to study the effect of oil displacement by injecting surfactant individually and the effect after injecting different profile control agent slug before surfactant flooding in heterogeneous cores. The results suggest that injecting Rui Feng surfactant and RZ-JD80 individually could enhance the oil displacement efficiency about 15 percentage points for homogeneous core. For strongly heterogeneous core, it is low efficiency by using either of these two surfactants individually. However, if injected a very little profile control agent slug before surfactant flooding, both of these two kinds of surfactant could enhance the oil recovery by different degree, especially, polymer microsphere plugging^RZ-JD80 flooding composite technology is more adaptable to Gao-63 reservoir. This technology could increase the recovery by 18.52 percentage points aRer surfactant flooding.

核糖核酸酶A的错流超滤复性

针对重组蛋白高表达形成的包涵体,基于中空纤维膜的错流超滤复性具有较大的应用潜力。为研究不同条件对基于中空纤维膜的错流超滤复性的影响,以核糖核酸酶A(RNase A)为例,以复性过程的活性收率和质量收率作为考察指标,设计了RNase A复性初始浓度(A)、跨膜压力(B)、循环流速(C)的3因素3水平正交实验。结果表明,错流超滤复性过程中,以上复性条件对RNase A的质量收率基本没有影响,对RNase A的活性收率具有显著影响,其较优组合为A1B1C2,即RNase A复性初始浓度为0.3 mg/mL、跨膜压力34.0 kPa、循环流速935 cm/min。在以上复性条件下,RNase A的活性收率可达92.31%,质量收率为77.56%。

Effect of Nitrogen Starvation on the Responses of Two Rice Cultivars to Nitrate Uptake and Utilization

Ammonium(NH+4) is the main nitrogen(N) form for rice crops, while NH+4near the root surface can be oxidized to nitrate(NO-3)by NH+4-oxidizing bacteria. Nitrate can be accumulated within rice tissues and reused when N supply is insufficient. We compared the remobilization of NO-3stored in the tissue and vacuolar between two rice(Oryza sativa L.) cultivars, Yangdao 6(YD6, indica)with a high N use efficiency(NUE) and Wuyujing 3(WYJ3, japonica) with a low NUE and measured the uptake of NO-3, expression of nitrate reductase(NR), NO-3transporter genes(NRTs), and NR activity after 4 d of N starvation following 7-d cultivation in a solution containing 2.86 mmol L-1NO-3. The results showed that both tissue NO-3concentration and vacuolar NO-3activity were higher in YD6 than WYJ3 under N starvation. YD6 showed a 2- to 3-fold higher expression of OsNRT2.1 in roots on the 1st and 4th day of N starvation and had significantly higher values of NO-3uptake(maximum uptake velocity, Vmax) than the cultivar WYJ3.Furthermore, YD6 had significantly higher leaf and root maximum NR activity(NRAmax) and actual NR activity(NRAact) as well as stronger root expression of the two NR genes after the 1st day of N starvation. There were no significant differences in NRAmax and NRAact between the two rice cultivars on the 4th day of N starvation. The results suggested that YD6 had stronger NRA under N starvation, which might result in better NO-3re-utilization from the vacuole, and higher capacity for NO-3uptake and use, potentially explaining the higher NUE of YD6 compared with WYJ3.

Simultaneous determination of Repaglinide and Irbesartan in biological plasmas using micellar enhanced excitation-emission matrix fluorescence coupled with ATLD method

A highly sensitive and selective 3D excitation-emission fluorescence method has been proposed to rapidly quantify the combined antidiabetics Repaglinide(Re) and Irbesartan(Ir) in rat and human plasmas with the aid of second-order calibration method based on alternating trilinear decomposition(ATLD) method. Re and Ir with weak fluorescence can be endowed with strong fluorescent property by changing the microenvironment in samples and improving the fluorescence quantum yield by using an appropriate micellar enhanced surfactant. The enhanced excitation-emission matrix fluorescence of Re and Ir can be accurately resolved and can simultaneously attain the optimal concentration even in the presence of a potentially strong intrinsic fluorescence from complex biological matrices, such as rat and human plasmas, by using the ATLD method, which completely exploits the "second-order advantage". The average recoveries of Re and Ir obtained from ATLD with the factor number of 3(N=3) were 101.0%±4.3% and 99.1%±4.1% for rat plasma and 100.5%±5.4% and 97.1%±3.6% for human plasma. Several statistical methods, including Student's t-test, figures of merit, and elliptical joint confidence region, have been utilized to evaluate the accuracy of the proposed method. Results show that the developed method can maintain second-order advantage in simultaneous determinations of the weak fluorescent analytes of interest in different biological plasma matrices.