Establishment of Reverse-transcription Loopmediated Isothermal Amplification Method for Detection of Wheat Streak Mosaic Virus

A reverse-transcription loop-mediated isothermal amplification （RT-LAMP） method was established for the detection of wheat streak mosaic virus （WSMV）. Ac-cording to the conservative regions of the genes that encode the coat protein of WSMV, 2 pairs of primers were designed. Final y, the 1st pair of primers was select-ed through the specificity test. The sensitivity test showed the sensitivity of RT-LAMP method was 10 times higher than that of RT-PCR. In addition, the amplifica-tion of target gene could be judged visual y from the presence of fluorescence （cal-cein） in the final reaction system. The RT-LAMP method, established in this study, was rapid, easy, specific and sensitive. Moreover, it did not require sophisticated equip-ment. The RT-LAMP was suitable for the rapid detection of WSMV.

Study on Kinetics of Iron Oxide Reduction by Hydrogen

Kinetics parameters of iron oxide reduction by hydrogen were evaluated by the isothermal method in a differential micro-packed bed. Influence of external diffusion, internal diffusion and heat transfer on the intrinsic reaction rate was investigated and the conditions free of internal and external diffusion resistance have been determined. In the experiments, in order to correctly evaluate the intrinsic kinetics parameters for reducing Fe203 to Fe3O4, the reaction temperatures were set between 440 ℃ and 490 ℃. However, in order to distinguish the reduction of Fe304 to FeO from that of FeO to Fe, the reaction temperature in the experiment was set to be greater than 570 ℃. Intrinsic kinetics of iron oxide reduction by hydrogen was established and the newly established kinetic models were validated by the experimental data.

Phase Equilibrium of Quaternary System Cd^(2+)//Cl^-,SO_4^(2-),NO_3^--H_2O at 298 K

Solid-liquid equilibrium of quaternary system Cd2＋//Cl–, SO42–, NO3–-H2O at 298 K was studied by means of an isothermal solution saturation method. Experimental results indicate that there are three univariant curves BE, AE and CE, one invariant point E and three crystallization fields in the quaternary system. The quaternary system belongs to a simple type, and there are no double salts or solid solution existing. The crystallization zones of equilibrium solid phases are CdCl2·5/2H2O（AEB field）, 3CdSO4·8H2O（AEC field） and Cd（NO3）2·4H2O（BEC field）, respectively. The composition of the invariant point is CdCl2, Cd（NO3）2, CdSO4 and H2O and the contents of which are 17.02%, 45.50%, 4.52% and 32.96%, respectively. The physico-chemical properties of solution in the quaternary system show regular changes along with the increased cadmium concentration. The results indicate that Cd（NO3）2 possessed the highest solubility among those three salts, which means a strong transfer of Cd ion and a high pollution risk of soil environment. And the solubility of CdSO4 would be restrained as the salts existing together.

A new strategy based on acid-alkali complexation for rapidly and accurately fishing phytochemicals in Sennae Folium

Objective:There are some anthraquinones,anthraquinones and flavonones in Sennae Folium which exhibited significant acidity,such as sennoside A/B and sennoside C/D.The current strategies used in separating these components are mainly based on conventional column chromatography which is time consuming,laborious and costly.This study is aimed at exploring a method of precipitation extraction of acid components in Sennae Folium.Using alkaloid as a"hook",it is reasonable to use the principle of"acid-alkali complexation"to"fish"the acidic components in Sennae Folium.Methods:Isothermal titration calorimeter(ITC)was used to measure the extraction efficiency of different alkaloids.Then,alkaloid determined by ITC was mixed with extracting solution of Sennae Folium to form complex.High performance liquid chromatography coupled with mass spectrometry(HPLC-MS2)was used to investigate the ingredients"fished"by berberine(Ber).The mechanism of"fishing"process was explained by ITC,optical activity,fluorescence spectrometry and scanning electron microscope.Results:The ITC results proved that the choice of"hook"was particularly important in the process of"fishing".Among the hooks,the fishing efficiency of the isoquinoline alkaloids(Ber)was the highest,reaching 10.3%.Nine ingredients were detected and determined by HPLC-MS2,and the main components were sennoside A/B and sennoside C/D.Based on ITC test of Ber and sennoside A,the combination mechanism of the two ingredients was a chemical reaction with a nearly binding ratio(2:1).Fluorescence and optical properties of the active ingredients were changed after complexation.By scanning electron microscope,we found that two types of components had obviously self-assembled behavior during the formation process.Conclusion:Ber successfully"fished"the main acidic components,sennoside A/B and sennoside C/D,from Sennae Folium.Combined with different characterizations,the"fishing"process was determined as a chemical association reaction induced by electrostatic interaction orπ-πstacking.Therefore,with special identification ability,the"fishing"process had the potential of practical application.