Authors:Yaling Chi, Yuantao Chen, Xia Liu, Zhijun Guo and Linsen Cai
The sorption of UO22+ from aqueous solution on attapulgite was investigated as a function of contact time, solid content, pH, ionic strength, foreign
ions, humic acid (HA), and fulvic acid (FA) under ambient conditions by using batch technique. The attapulgite sample was
characterized by XRD and FTIR in detail. The results indicated that the sorption of UO22+ was strongly dependent on pH and ionic strength. The sorption of UO22+ on attapulgite increased quickly with rising pH at pH < 6.5, and decreased with increasing pH at pH > 6.5. The presence of
HA or FA enhanced the sorption of UO22+ on attapulgite obviously at low pH because of the strong complexation of surface adsorbed HA/FA with UO22+ on attapulgite surface. Sorption of UO22+ on attapulgite was mainly dominated by ion-exchange or outer-sphere surface complexation at low pH values, but by inner-sphere
surface complexation at high pH values. The results indicate that attapulgite is a very suitable adsorbent for the preconcentration
and solidification of UO22+ from large volumes of aqueous solutions because of its negative surface charge and large surface areas.
Authors:Liu Xia, Chen Yuantao, Chi Yaling, Guo Zhijun and Cai Linsen
In this article, a series of batch experiments were carried out to investigate the effect of various environmental factors
such as contact time, solid content, pH, ionic strength, foreign ions, temperature and coexisting humic acid on the sorption
behavior radionuclide 60Co(II) on illite. The results indicated that the sorption of Co(II) was strongly dependent on pH, ionic strength and temperature.
At low pH, the sorption was dominated by outer-sphere surface complexation and ion exchange on illite surfaces, whereas inner-sphere
surface complexation was the main sorption mechanism at high pH. The Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models
were used to simulate the sorption isotherms at three different temperatures of 303.15, 323.15 and 343.15 K. The thermodynamic
data (∆G0, ∆S0, ∆H0) were calculated from the temperature dependent sorption isotherms and the results suggested that the sorption process of
Co(II) on illite was an endothermic and spontaneous process. The sorption test revealed that the illite can be as a cost-effective
adsorbent suitable for pre-concentration of Co(II) from large volumes of aqueous solutions.
Authors:Mina Luo, Huaqiao Ma, Xia Liu and Shengxiang Jiang
A simple and precise high-performance liquid chromatographic (HPLC) method has been developed for analysis of flavonoids in Lamiophlomis rotata. HPLC conditions were optimized. Baseline separation was achieved by use of a binary gradient prepared from 100:0.2 (v/v) water-trifluoroacetic acid (component A), and acetonitrile (component B). The gradient was from 20 to 35% B in 10 min, hold at 35% B for 20 min, then from 35 to 70% B in 10 min. The injection volume was 10 μL, and the detection wavelength was 366 nm. Linearity and precision were investigated. When normal least-squares linear regression (LSLR) was compared with weighted least-squares linear regression (WLSLR), values obtained by use of the latter were much closer to the actual values, over the whole range of concentration, than those obtained by use of the former. WLSLR was therefore used in this work. This HPLC method was successfully used for analysis of the flavonoids in Lamiophlomis rotata and could be effective for quality control of the plant.
Authors:Guangjuan Ren, Yuan Gao, Xia Liu, An Xing, Huitao Liu and Jungang Yin
A simple method for preparing F-doped anatase TiO2 nanoparticles with high visible light photocatalytic activity was developed using TiCl4 and HF as TiO2 and fluorine precursors in HCl solution by a one-step hydrothermal treatment without any organic species. The presence of
HF plays an important role in the formation of the F-doped shuttle-like anatase TiO2 nanostructures. XRD analysis showed that the F− could prevent the transformation of anatase to rutile in HCl solution. Compared with ordinary TiO2, the F-doped TiO2 nanoparticles synthesized at 180 °C exhibited better photocatalytic activity for the degradation of rhodamine B under visible
light irradiation. Possible formation mechanism of F-doped anatase TiO2 under hydrothermal conditions was discussed.
The importance of angiogenesis in tumor growth and metastasis has led to develop new imaging tracers to understand angiogenic
vasculature. Based on the previous study, we further focused on the tumor molecular imaging application of the novel peptide
Arginine-Arginine-Leucine (Tyr-Cys-Gly-Gly-Arg-Arg-Leu-Gly-Gly-Cys, tRRL) in this study. The cytotoxicity of raioiodinated
tRRL (131I-tRRL) in HepG2 cells was assessed by tested cell viability using kit. tRRL was conjugated with fluorescein FITC to observe
its binding with tumor cells and human aortic endothelial cells (HAEC) in vitro. Whole body SPECT imaging of varied tumors
xenograftes was performed after intravenous injection of 131I-tRRL for 24 h in BALB/c nude mice. Compared with negative control PBS, small peptide tRRL was of non-cytotoxicity. 131I-tRRL could lead to significant cytotoxicity on HepG2 cells when the radioactivity was greater than 370 kBq. In vitro binding
experiment and cellular uptake results revealed that tRRL could adhere to tumor cells besides tumor derived endothelial cells.
In vivo SPECT imaging, 131I-tRRL mainly accumulated in various tumor tissues, including melanoma, liver cancer and lung cancer bearing mice. In breast
cancer xenografte imaging, the tumor has no significant radionuclide accumulation at 24 h after injected of 131I-tRRL. Radioiodinated tRRL offers a noninvasive nuclear imaging method for functional molecular imaging of tumors, and may
be a promising candidate carrier for tumor targeted therapy.
Authors:Chen Cheng, Nie Cun-Xi, Liang Jing, Wang Yong-Qiang, Liu Yan-Feng, Ge Wen-Xia and Zhang Wen-Ju
A validated high-performance liquid chromatography (HPLC) method has been developed to analyze the (±)-gossypol in the selection of strains of Candida tropicalis culture. Since gossypol was easily degraded and oxidized, the addition of antioxidant NADPH-Na4 and acetone extraction was chosen to prevent gossypol degradation and gradient elution assay was applied to obtain gossypol resolution. Concentrations of gossypol in C. tropicalis ZD-3 culture 20 μg/mL were determined, and concentration–time profiles were observed. Linearity of the gossypol standard curve by HPLC area method was ranged from 0.1 to 20 μg/mL with Y = 26.954 × X − 29.547, R2 = 0.9991, and n = 3, with limit of detection (LOD) of 50 ng/mL and lower limit of quantification (LLOQ) of 500 ng/mL. The recovery rate is dose-dependent and ranged from 85.3% to 103.5%. It is a rapid and reliable HPLC method for gossypol quantization in microorganism culture which could be applied in solid fermentation in the feed industry.
Authors:Mei-Xia Zhu, Sheng-Nan Li, Hai-Dan You, Bin Han, Zhi-Ping Wang, Yan-Xi Hu, Jin Li and Yu-Feng Liu
High-performance liquid chromatography coupled with photodiode array detection and evaporative light scattering detection (HPLC—DAD—ELSD) was established to determine paeoniflorin and albiflorin simultaneously in Radix Paeoniae Rubra. The assay was performed on a Diamonsil C18 (4.6 mm × 250 mm, 5 μm) column by a gradient elution program with acetonitrile and aqueous formic acid (0.05% v/v) as mobile phase at a flow rate of 1.0 mL min−1. The detection wavelength of DAD was 230 nm, and the evaporator tube temperature of ELSD was set at 110 °C with the nebulizing gas flow rate of 3 L min−1. The temperature of column was kept at 30 °C. The linear ranges of paeoniflorin and albiflorin were within 0.050–1.510 mg mL−1 and 1.007–5.035 mg mL−1. The recoveries of paeoniflorin and albiflorin were 96.2–102.9% and 95.0–102.4%, respectively, while the relative standard deviation (RSD) of them was 0.2–2.5%. This method was quick, simple, accurate, and specific. It could be used for the quality control of Radix Paeoniae Rubra. The proposed approach was expected as a powerful tool for the quality control of Radix Paeoniae Rubra.
Authors:Xia Yang, Lei Feng, Kang-Zhen Xu, Hui-Zhou Gao, Chao Jia, Cheng-Cheng Liu, Jian-Min Xiao, Le Zhai, Li-Sheng Zhou and Ke-Wu Yang
In an effort to understand the reaction of antibiotic hydrolysis with B2 metallo-β-lactamases (MβLs), the thermodynamic parameters of imipenem hydrolysis catalyzed by metallo-β-lactamase ImiS from Aeromonas veronii bv. sobria were determined by microcalorimetric method. The values of activation free energy are 86.400 ± 0.043, 87.543 ± 0.034, 88.772 ± 0.024, and 89.845 ± 0.035 kJ mol−1 at 293.15, 298.15, 303.15, and 308.15 K, respectively, activation enthalpy is 18.586 ± 0.009 kJ mol−1, activation entropy is −231.34 ± 0.12 J mol−1 K−1, apparent activation energy E is 21.084 kJ mol−1, and the reaction order is 1.5. The thermodynamic parameters reveal that the imipenem hydrolysis catalyzed by metallo-β-lactammase ImiS is an exothermic and spontaneous reaction.
Radiolabeling of biologically active molecules with fac-[188Re(CO)3(H2O)3]+ unit has been of primary interest in recent years. Therefore, we herein report ligands L1−L4 (L1=histidine, L2=nitrilotriacetic acid, L3=2-picolylamine-N,N-diacetic acid, L4=bis(2-pyridymethy)amine) that have been evaluated by radiochemical reactions with fac-[188Re(CO)3(H2O)3]+. These reactions yielded the radioactive complexes of fac-[188Re(CO)3L] (L = L1−L4, 188Re tricarbonyl complexes 1–4), which were identified by HPLC. Complexes 1–4, with log Po/w values ranging from −2.23 to 2.18, were obtained with yields of ≥95% using ligand concentrations within 10−6–10−4M range. Thus, specific activities of 220 GBq/μmol could be achieved. Challenge studies with cysteine and histidine revealed
high stability for all of these radioactive complexes, and biodistribution studies in mice indicated a fast rate of blood
clearance and high rate of total radioactivity excretion occurring primarily through the renal-urinary pathway. In summary,
the ligands L1–L4 are potent chelators for the future functionalization of biomolecules labeling with fac-[188Re(CO)3(H2O)3]+.