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Abstract  

In terms of pre-safety assessment of a potential site for high-level radioactive wastes disposal in China, the geochemical behavior of key radionuclides which tend to be released from the repository must be thoroughly investigated. 99Tc is a long-lived fission product with appreciable productivity in nuclear fuel, and Tc (+7) has unlimited solubility in near-field geochemical environments. In this study, the effects of ionic strength and humic acid on 99TcO4 sorption and diffusion in Beishan granite were investigated with through-diffusion and batch sorption experiments. Results indicated that the effective diffusion coefficients (D e) of 99TcO4 in Beishan granite varied from 1.07 × 10−12 to 1.28 × 10−12 m2/s without change with ionic strength, while the distribution coefficients (K d) negatively correlated with ionic strength of the rock/water system. This study also indicates that there is no evident influence of humic acid concentration on the diffusion behavior of 99TcO4 in Beishan granite, due to the limited interaction between humic acid and 99TcO4 .

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The aim of this study was to investigate the effects of maternal lead exposure on the learning and memory ability and expression of tau protein phosphorylation (P-tau) and beta amyloid protein (Aβ) in hippocampus of mice offspring. Pb exposure initiated from beginning of gestation to weaning. Pb acetate administered in drinking solutions was dissolved in distilled deionized water at the concentrations of 0.1%, 0.5% and 1% groups. On the 21 th of postnatal day, the learning and memory ability of the mouse pups was tested by Water Maze test and the Pb levels in blood and hippocampus of the offspring were also determined. The expression of P-tau and Aβ in hippocampus was measured by immunohistochemistry and Western blotting. The Pb levels in blood and hippocampus of all exposure groups were significantly higher than that of the control group ( P < 0.05). In Water Maze test, the performances of 0.5% and 1% groups were worse than that of the control group ( P < 0.05). The expression of P-tau and Aβ was increased in Pb exposed groups than that of the control group ( P < 0.05). Tau hyper-phosphorylation and Aβ increase in the hippocampus of pups may contribute to the impairment of learning and memory associated with maternal Pb exposure.

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Patrinia scabra Bunge has long been used in clinic as a traditional Chinese medicine for treating leukemia and cancer and regulating host immune response. Despite their wide use in China, no report on system analysis on their chemical constituents is available so far. The current study was designed to profile the fingerprint of ethyl acetate extract of it, and in addition, to characterize the major fingerprint peaks and determine their quantity. Therefore, a detailed gradient high-performance liquid chromatography was described to separate more than 30 compounds with satisfactory resolution in P. scabra Bunge. Based on the chromatograms of 10 batches samples, a typical high-performance liquid chromatographic (HPLC) fingerprint was established with 23 chromatographic peaks being assigned as common fingerprint peaks. Furthermore, a quadrupole time of flight mass spectrometry (Q-TOF/MS) was coupled for the characterization of major compound. As (+)-nortrachelogenin was the most predominant compound in P. scabra Bunge, the quantification on it was also carried out with the method being validated. As a result, (+)-nortrachelogenin was found to be from 1.33 to 2.21 mg g−1 in this plant material. This rapid and effective analytical method could be employed for quality assessment of P. scabra Bunge, as well as pharmaceutical products containing this herbal material.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
Li-Fang Song
,
Cheng-Li Jiao
,
Chun-Hong Jiang
,
Jian Zhang
,
Li-Xian Sun
,
Fen Xu
,
Qing-Zhu Jiao
,
Yong-Heng Xing
,
F. L. Huang
,
Yong Du
,
Zhong Cao
,
Fen Li
, and
Jijun Zhao

Abstract

One-three-dimensional metal-organic frameworks Mg1.5(C12H6O4)1.5(C3H7NO)2 (MgNDC) has been synthesized solvothermally and characterized by single crystal XRD, powder XRD, FT-IR spectra. The low-temperature molar heat capacities of MgNDC were measured by temperature modulated differential scanning calorimetry (TMDSC) over the temperature range from 205 to 470 K for the first time. No phase transition or thermal anomaly was observed in the experimental temperature range. The thermodynamic parameters of MgNDC such as entropy and enthalpy relative to reference temperature of 298.15 K were derived based on the above molar heat capacities data. Moreover, the thermal stability and decomposition of MgNDC was further investigated through thermogravimetry (TG)–mass spectrometer (MS). Three stages of mass loss were observed in the TG curve. TG–MS curve indicated that the oxidative degradation products of MgNDC are mainly H2O, CO2, NO, and NO2.

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