Experimental crushed granite column breakthrough curves, using 99Tc as spike tracer and 3H as invariant tracer, were analyzed by different linear regression techniques. Dispersity of crushed granite and the retardation factor of 99TcO4- on the crushed granite were determined simultaneously by one linear regression. Dispersity of crushed granite was also obtained with 3H as invariant tracer by the other linear regression. The dispersities found by spike source and invariant source methods are compared. Experimental results show that the dispersity found by the spike source method is close to that found by the invariant source method. This indicates that dispersity is only a characteristic of the dispersion medium.
The adsorption of 99Tc on the adsorbers Fe, Fe2O3 and Fe3O4 was studied by batch experiments under aerobic and anoxic conditions. The effects of pH and CO32- concentration of the simulated ground water on the adsorption ratios were also investigated, and the valences of Tc in solution after the adsorption equilibrium were studied by solvent extraction. The adsorption isotherms of TcO4- on the adsorbers Fe, Fe2O3 and Fe3O4 were determined. Experimental results have shown that the adsorption ratio of Tc on Fe decreases with the increase of pH in the range of 5-12 and increases with the decrease of the CO32- concentration in the range of 10-8M-10-2M. Under aerobic conditions, the adsorption ratios of 99Tc on Fe2O3 and Fe3O4 were not influenced by pH and CO32-concentration. When Fe was used as adsorbent, Tc existed mainly in the form of Tc(IV) after equilibrium and in the form of Tc(VII) when the adsorbent was Fe2O3 or Fe3O4 under aerobic conditions. The adsorption ratios of Tc on Fe, Fe2O3 and Fe3O4 decreased with the increase of pH in the range of 5-12 and increased with the decrease of the CO32- concentration in the range of 10-8M-10-2M under anoxic conditions. Tc existed mainly in the form of Tc(IV) after equilibrium when Fe, Fe2O3 and Fe3O4 was the adsorbent under anoxic conditions. The adsorption isotherms of TcO4- on the adsorbers Fe, Fe2O3 and Fe3O4 are fairly in agreement with the Freundlich’s equation under both aerobic and anoxic conditions.
Authors:H. Bai, H. Jin, H. Fan, J. Du, F. Wang, D. Chen and Zh. Cheng
The behavior of153Sm-EDTMP in vitro and vivo is analyzed by the size exclusion HPLC. The experimental results show that EDTMP amounts have an
obvious effect on the stability in vitro and uptake of153Sm-EDTMP in the liver. HPLC analysis of urine sample indicates that153Sm-EDTMP es excreted in the original form. The behavior in vivo of153Sm-EDTMP containing 4 μg is similar to that of153Sm-EDTMP containing 50 μg EDTMP at 1 h post-injection.
Authors:F. Wang, H. Fan, D. Chen, H. Bai, Z. Chen and L. Xiao
Radiolabeled somatostatin analogue is a useful ligand for scintigraphic imaging of somatostatin receptor-bearing tumors. In
this study, we investigated the effects of different radiolabeling conditions on labeling yield and ratio between mono-iodinated
and di-iodinated125I-Tyr3-octreotide by HPLC analysis. In vitro and in vivo stabilities of125I-Tyr3-octreotide and111In-DTPA-D-Phe1-octreotide were also determined. Both radiolabeled compounds were relatively stable in vitro, but were decomposed to free125I− and111In-DTPA in vivo, respectively.
Authors:Z. Cheng, Q. Lin, X. Jin, F. Wang, H. Bai, D. Chen, H. Fan and J. Du
DTPA-Octreotide(Pentetreotide), a somatostatin analogue which can bind specifically and with high affinity to somatostatin
receptor in vitro and vivo, labeled with99mTc by tin reduction in acetate buffer, has been characterized by Reverse-phase High performance Liquid Chromatography. The
effect of different solvents, mobile phase pH, linear gradient and the injected volume on the separation efficiency was evaluated.
The results show that the separation efficiency is best using μBondapak-C18 (300×3.9 mm2), linear gradient of 40% to 80% methanol (1.0 ml/min) in 0.05M acetate buffer (pH 5.5) over a 30 min period and maintaining
for another 10 min. The labeled product is a mixture which mainly consists of five components (a, b, c, d, e) successfully
proved by HPLC. Paper chromatography is also evaluated in this paper. It may be used to determine the radiochemical purity
of the labeling product, but is not a good choice for the verification each components.
Authors:X. H. Fan, H. J. He, J. Wang, C. Y. Xu and K. v. Gadow
The geographical patterns of tree species richness in forest communities have been studied widely, but little is known about the geographical variation of the estimated species richness and minimum areas using species-area curves. A differential technique based on the species-area relationships (SAR) was developed for estimating the minimum area (Amin) capturing 60- 80% of the species in each plot, which is an important characteristic of a forest community. The relationship between estimated species richness (ESR) from the SAR and the corresponding minimum area is described by the linear model ESR = 0.0051×Amin (R2 = 0.98, p < 0.0001). Both the ESR and the minimum area exhibit similar geographical variations with a significant increase along altitudinal and a decrease along latitudinal gradients. The spatial variations of the ESR were partitioned into three geographical components and their combined effects. Altitude accounted for 40% and 45% of the total variation in the ESR and the minimum area, respectively. While latitude accounted for 69% and 61% of the total variation in the ESR and the minimum area, respectively. Thus, latitude is the main determinant which influences the geographical variation of the ESR. As far as we know, this study presents the first report of the geographical patterns of the minimum area in temperate forests.
Authors:Q. Xu, H. Fan, Z. Jiang, Z. Zhou, L. Yang, F. Mei and L. Qu
This research was aimed to study the cell wall degradation and the dynamic changes of Ca2+ and related enzymes in developing aerenchyma of wheat root under waterlogging. An examination of morphological development by light and electron microscope revealed that the structure of cell wall in middle cortical cells remained intact after 12 h of waterlogging and turned thinner after waterlogging for 24 h. At 48 h, the aerenchyma has been formed. The cellulase activity gradually increased in middle cortical cells within 24 h of waterlogging, and decreased with the formation of aerenchyma. Fluorescence detection and subcellular localization of Ca2+ showed the dynamic changing of Ca2+ at the cellular and subcellular levels during the development of aerenchyma. The activity of Ca2+-ATPase enhanced markedly in intercellular space, plasma membrane and tonoplast of some middle cortical cells after 8 h of waterlogging and remained high after 24 h, but it decreased after 48 h of waterlogging. All these suggests that cellulase, Ca2+ and Ca2+-ATPase show a dynamic distribution during the aerenchyma development which associated with the cell wall degradation of middle cortical cells. Moreover, there is a feedback regulation between Ca2+ and Ca2+-ATPase.
Authors:H. Yang, Hua Yin, Z. Wang, L. Fan, Q. Li and X. Zhu
Traditional Chinese medicine (TCM) has been widely used in many countries for thousands of years and played an indispensable role in the prevention and treatment of diseases, especially the complicated and chronic ones. However, the application of TCM in diseases is still not fully recognized by people around the world, the main reason is that Chinese herb is a very complex mixture containing hundreds of different components. Thus, it is essential to make quality control and evaluation of TCM. A new quality evaluation method, quantitative analysis of multi-components by single marker (QAMS), was developed to the quality control of alkaloids in TCM, a case study on Radix aconiti lateralis, named Fuzi in Chinese. Six alkaloids, including aconitine, hypaconitine, mesaconitine, benzoylaconine, benzoylmesaconine, and benzoylhypaconine, were selected as main components to evaluate the quality of Radix aconiti lateralis. The feasibility and accuracy of QAMS were checked by the external standard method, and various high-performance liquid chromatographic instruments and chromatographic conditions were investigated to verify its applicability. Using aconitine as the internal reference substance and the content of aconitine was calculated according to relative correction factors by high-performance liquid chromatography. The present results showed that there was no significant difference observed between the QAMS method and the external standard method with the relative average deviations less than 3.0%, and QAMS is an effective way to control the quality of herbal medicines and seems to be a convenient and accurate approach to analyze multi-composition when reference substances are unavailable.
Authors:Y.G. Shi, Y. Lian, H.W. Shi, S.G. Wang, H. Fan, D.Z. Sun and R.L. Jing
Senescence in a wheat (Triticum aestivum L.) leaf is a programmed degeneration process leading to death. During this process, green leaf area duration (GLAD) and green leaf number of main stem (GLNMS) are gradually reduced. In this study, the two traits of Hanxuan10/Lumai14 DH population at different development stages after anthesis were evaluated under rainfed and irrigated conditions, and QTLs were detected. GLAD and GLNMS of two parents and DH population under rainfed condition were less than those under irrigated condition, and close correlations (P < 0 05) were found between GLAD and GLNMS after 25 DAA under both water conditions. GLAD and GLNMS were co-controlled by major and minor genes. QTLs for GLAD were stably expressed at different development stages after anthesis under both water conditions, such as QGlad22-1B-1, QGlad25-1B-1, QGlad28-1B-2 detected under irrigated condition and QGlad25-1B-3, QGlad28-1B-4 mapped under rainfed condition were located at a 20.7 cM marker interval of Xgwm273-EST122 on 1B chromosome. But QTLs for GLNMS were inducibly and specifically expressed at specific developmental stages after anthesis under both water conditions. The findings provide dynamic genetic information related to wheat senescence.