A study on solvent extraction of cerium/III/ ion with 1-/2-pyridylazo/-2-naphthol /PAN or HL/ in chloroform from perchloric acid solution is described. The effect of equilibrium time, the pH of the aqueous phase and the concentration centration of extractant in organic phase on the extraction efficiency of cerium/III/ has been studied. The results show that the mechanism of extraction reaction is 3Ce
CeL3/o/ + 3H
Authors:Zhu Zhaowu, He Jianyu, Zhang Zefu, Zhang Yu, and Zheng Weifang
The kinetics of the reduction of plutonium(IV) by hydroxyurea (HU), a novel salt free reductant, in nitric acid solutions
has been studied. The observed reaction rate can be expressed as: -d[Pu(IV)]/dt=k0[Pu(IV)]2[HU]/[H+]0.9, where k0 = 5853±363 (l1.1.mol-1.1.s-1) at t = 13 °C. The activation energy is about 81.2 kJ/mol. The study also shows that uranium(VI) has no appreciable influence on
the reaction rate. Compared with other organic reductants our experiments indicate that HU is a very fast reductant for plutonium(IV).
Authors:Zhen Li, Li Yu, Liqiang Zheng, and Fei Geng
In this work, solid lipid nanoparticles (SLN) have been prepared from water-in-oil-in-water double emulsion, using monocaprate as solid lipid, sorbitan monooleate (Span 80) and polyoxyethylene sorbitan monolaurate (Tween 20) as emulsifier, and puerarin as target drug. The morphology of SLN with drug loaded or not was investigated by the transmission electron microscope (TEM). The crystal order and structure of particles were studied by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD), respectively. The results indicate that the diameters of SLN with puerarin inside are larger than those without drugs. The analysis of WAXD and DSC shows that the state of crystallinity SLN prepared by double emulsion method was worse than that of SLN prepared by microemulsion. And also the drug-loaded SLN presents a less ordered crystallinity than the drug-free SLN. But both the drug-free and drug-loaded SLN exist in an amorphous state. The reasons of the phenomenon have been discussed.
Authors:Deqiao Tian, Yunzhou Yu, Yumin Wang, and Tao Zheng
The proportion of pathogenic microorganisms in the microbial world is relatively small, while their threat to human health, economic development and social stability is severe. The quantity and variation of Science Citation Index (SCI) literature related to pathogenic microorganisms may reflect the level of relevant research and the degree of attention. Here we compared trends in the quantity and variety of SCI literature relating to certain important pathogenic microorganisms published by scientists from United States and China from 1996 to 2010 by searching the Science Citation Index database. The pathogenic microorganisms in this study comprise two categories of pathogens: Bacillus anthracis, Yersinia pestis, Francisella tularensis, Ebola virus, Burkholderia pseudomallei, which belong to biodefense-associated pathogens (BDAPs) and the human immunodeficiency virus (HIV), SARS coronavirus, hepatitis B virus (HBV), Mycobacterium tuberculosis, influenza virus, which belong to the commonly encountered health-threatening pathogens. Our results showed that the United States (US) published much more SCI literature on these pathogens than China. Furthermore, literature on BDAPs published by scientists from the US has increased sharply since 2002. However, the numbers of literature relating to CEHTPs from China has demonstrated a gradual increase from 1996 to 2010. Research into pathogenic microorganisms requires three balance to be achieved: investment in BDAP and CEHTP studies; basic and applied research; a faster pace of research into pathogens and fulfilling biosafety and biosecurity requirements.
Authors:Jun Yuan, Wei Yue, Cheng Su, Zheng Wu, Zheng Ma, Yun Pan, Nan Ma, Zhi Hu, Fei Shi, Zheng Yu, and Yi Wu
This research intends to investigate the patent activity on water pollution and treatment in China (1985–2007), and then compares
the results with patents data about Triadic patents, South Korea, Brazil and India over the same periods, patents data were
collected from Derwent World Patents Index between 1985 and May 2008. For this study, 169,312 patents were chosen and examined.
Total volume of patents, technology focus, assignee sector, priority date and the comparison with other countries are analyzed.
It is found that patents on water pollution and treatment filed at China have experienced a remarkable increase and the increase
rate of patents filed at China change simultaneous with the percentage of domestic applications. However, the number of high
quality Triadic patents with priority country as China remains small. Furthermore, in addition to individual patent assignees,
both Chinese universities and enterprises also play important roles in patent activity of water pollution and treatment. In
addition, the pattern of South Korea’s development can provide short-term implications for China and the regularity in Triadic
patents’ development can provide some guidance to China’s long-term development. In contrast, the development pattern of Brazil
and India is less influential to China’s development. Furthermore, China’s technology focuses on water pollution and treatment
seem to parallel global and triadic patent trends. This research provides a comprehensive picture of China’s innovation capability
in the area of water pollution and treatment. It will help China’s local governments to improve their regional S&T capability
and will provide support the National Water Pollution Control and Treatment Project in China.
Authors:Shao-Ning Yu, Zheng-Ping Fan, Li Ma, Yan-Zhao Yang, and Bo-Rong Bao
The influence of the concentration of nitric, hydrochloric and phosphoric acids, petroleum sulfoxides (PSO), salting-out agent,
kind of diluent and temperature on the distribution ratio of U(VI) and Th(IV) has been systematically studied. It is found
that the extraction regularity of PSO is similar to that of TBP. The distribution ratio in phosphoric acid is lower, but it
increases with the increase of hydrochloric acid concentration and reaches a high value. The U(VI) exhibits the maximum distribution
ratio at 3–4 mol/l HNO3. The distribution ratio of U(VI) and Th(IV) increases rapidly in the presence of a salting out agent. The extracted compounds
are determined to be UO2(NO3)22PSO and Th(NO3)42PSO. The extraction enthalpies of U(VI) and Th(IV) with PSO were also calculated.
Authors:X. Zheng, Y. Yu, G. Xiao, Y. Xu, J. Wu, D. Tang, Y. Cheng, and Y. Zhang
Changes in microbial population, pH, sugar, organic acid, anthocyanins, total soluble phenolics, and anti-glucosidase contents were measured during fermentation of mulberry juice at 30 °C by probiotic Leuconostoc mesenteroides showing rapid growth after an approximately 1-day lag phase and reaching a maximum of 8.6 log CFU ml−1 after 4 d. During the rapid growth phase, the main mulberry juice sugars, glucose and fructose, were largely consumed, and the acidic metabolites, lactic acid and acetic acid, were produced accordingly. A slow decrease in the concentration of the main organic acid, citric acid, was also observed during fermentation. After 4 d fermentation, anthocyanin content showed a 44.4% reduction, but the total amount of soluble phenolics and α-glucosidase inhibitory activity showed no significant changes (P>0.05). This suggests that L. mesenteroides fermentation of mulberry juice is a good strategy to enhance its probiotic value and to decrease the sugar content without changing the anti-glucosidase activity, which is required to reduce postprandial rise in blood glucose.
Authors:Lixia Wang, Wanchun Zhu, Dafang Zheng, Xue Yu, Jing Cui, Mingjun Jia, Wenxiang Zhang, and Zhenlu Wang
The reaction of direct transformation of ethanol to ethyl acetate was investigated on reduced Cu/ZrO2 catalysts prepared by a co-precipitation procedure. The catalytic performances of these Cu–Zr mixed oxides were considerably
influenced by changing the molar ratio of Cu to Zr. The highest selectivity to ethyl acetate was found over Cu/ZrO2(1) catalyst (molar ratio of Cu to Zr was 1). A variety of characterization techniques, such as N2 adsorption, XRD, XPS, TPR and NH3-TPD were carried out on the catalysts. The results revealed that the presence of a certain amount of Cu+ species may play very important role in improving the selectivity to ethyl acetate of the Cu/ZrO2 catalysts.
8-O-Acetylharpagide is the main active component of the herb Ajuga decumbens, which possesses anti-tumor, anti-virus, and anti-inflammation properties. In this study, ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was used to measure the concentration of 8-O-acetylharpagide in mouse blood, with subsequent investigation of the pharmacokinetics of the drug after intravenous or oral administration. Shanzhiside methyl ester was used as an internal standard, and the acetonitrile precipitation method was used to process the blood samples. Chromatographic separation was achieved using an ultra-performance liquid chromatography ethylene-bridged hybrid (UPLC BEH) column (2.1 mm × 50 mm, 1.7 μm) with a gradient methanol–water mobile phase (containing 0.1% formic acid). The flow rate was 0.4 mL/min, and the elution time was 5.0 min. 8-O-Acetylharpagide was quantitatively measured using electrospray ionization (ESI) tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive ionization. The result indicated that, within the range of 5–500 ng/mL, the linearity of 8-O-acetylharpagide in mouse blood was satisfactory (r > 0.995), and the lower limit of quantification (LLOQ) was 5 ng/mL. Intra-day precision relative standard deviation (RSD) of 8-O-acetylharpagide in blood was lower than 9%, and the inter-day precision RSD was lower than 13%. The accuracy range was between 94.3% and 107.1%, average recovery was higher than 91.3%, and the matrix effect was between 100.8% and 110.8%. This analytical method was sensitive and fast with good selectivity and was successfully applied to perform pharmacokinetic studies of 8-O-acetylharpagide in mice. The bioavailability of 8-O-acetylharpagide was 10.8%, and the analysis of the primary pharmacokinetic parameters after oral and intravenous administration indicated that 8-O-acetylharpagide had a significant first pass effect after oral administration.
Authors:M. Zheng, Y. Tian, H. Teng, J. Hu, F. Wang, Y. Zhao, and L. Yu
In this paper, the wind energy resource in China’s oilfields is analyzed, the difference between China’s energy consumption structure and that of the world in average is analyzed as well, and the application prospect of wind heating technology in China’s oilfields is discussed as an example to reform China’s energy consumption structure. It shows that it is possible to use wind energy as an appropriate heat resource or supplementary heat source in some oilfields to supply heat energy for oil heating and living, more room to improve the energy resource utilization in various fields in China remain. It is a benefit to both oilfield and society to improve energy saving and environments.