The extraction of uranium(VI) with bis(hexylsulfinyl)methane (BHxSM) from nitric acid aqueous solution has been investigated. It was found that the extraction increased with increasing nitric acid concentration up 8.5 mol/l and then decreased. Extraction distribution ratio also increased with the bis(hexylsulfinyl)methane concentration. The extraction species appear to be UO2(NO3)2.2BHxSM. The influences of temperature, salting-out concentration and oxalate concentration on the extraction equilibrium were also investigated, and the enthalpy of the extraction reaction was obtained. The result shows that the reaction of uranium(VI) extraction with BHxSM is an exothermic one.
The thermodynamic extraction of uranium(VI) with hexyloctylsulfoxide (HxOSO) has been studied. It was found that the distribution ratio increases with increasing nitric acid concentration up to 2.3 mol/l and then decreases. The distribution ratio also increases with increasing extractant concentration. The extracted species appears to be UO2(NO3)2.2HxOSO. The influences of temperature, sodium nitrate and oxalate concentrations on the extraction were also investigated, and the thermodynamic functions of the extraction reaction were obtained.
Authors:Gao Feng, Zhou Meiying, Zhao Xialing, Zhang Sunxi, and Wang Guoping
Endothelin (ET) is a novel endothelium-derived vasoconstrictive peptide, purified from porcine aortic endothelial cells.125I-ET was prepared by lodogen method and purified by HPLC, the specific activity was 62.9 TBq/mmol. The stability of125I-ET was investigated in different storage conditions by radioimmunoassay.
Authors:Yang Yan-Zhao, Sun Si-Xiu, and Feng Sheng-Yu
The liquid-liquid extraction behavior of 2-ethylhexyltolylsulfoxide (EHTSO) towards uranium(VI) contained in nitric acid aqueous solution has been investigated. It was found that the extraction increases with increasing nitric acid concentration up to 5.0 mol/l and then decreases. Extraction also increases with increasing extractant concentration. The extracted species appears to be UO2(NO3)2.2EHTSO. The influences of temperature, NH4NO3 and Na2C2O4 concentrations on the extraction equilibrium were also investigated and the thermodynamic functions of the extraction reaction were obtained.
Recently, it was reported that the toxicity of copper particles increases with the decrease of the particle size on a mass
basis. To understand this phenomenon, inductively coupled plasma mass spectrometry (ICP-MS) techniques and in vitro chemical
studies were carried out to explore how they produce toxicity in vivo. The results suggest that when the sizes of particles
become small and down to a nanoscale, copper becomes extremely reactive in a simulative intracorporeal environment. The nanosized
copper particles consume the hydrogen ions in stomach more quickly than micron ones. These processes further convert the copper
nanoparticles into cupric ions whose toxicity is very high in vivo.
Nanosized copper particles are widely used in fields of lubricants, polymers/plastic, metallic coating and ink. Recently,
we found that copper particles in different sizes can lead to different toxicological effects. To clarify the target organs
of copper particles of different sizes, the inductively coupled plasma mass spectroscopy (ICP-MS) was employed to evaluate
the distribution of copper in different organs of mice after a single dose oral exposure. The results suggest that the main
target organs for copper nanoparticles are kidney, liver and blood. Liver is the main damaged organ.
Authors:Sun Tong-Shan, Xiao Yu-Mei, Wang Da-Qing, Wang Feng-Lian, and Zhao Yu-Ting
The complexes of rare earth bromides with alanine, REBr33AlanH2O (RE=Ce, Pr, Sm, Eu, Gd and Tb, n=3; RE=Dy and Y, n=2.5
Ala=alanine), were prepared and characterized by means of chemical analysis, elemental analysis, molar conductivity, thermogravimetry,
IR spectra and X-ray diffraction. The thermal decomposition in N2 of these complexes was studied by means of TG-DTG techniques
from ambient temperature to 1000C. During heating, the hydrated complexes of Ce, Pr and Y lose waters in one step, but the
hydrated complexes of Sm, Eu, Gd, Tb and Dy lose waters in two steps. Then anhydrous complexes lose 2.5 alanine molecules
except the complexes of Eu which lose three alanine molecules. Apparently, only be complex of Eu has an intermediate, EuOBr.
All complexes finally decompose to oxides.
Authors:Y. Zhao, C. Zhang, C. Qi, S. Feng, G. You, Z. Fu, F. Guo, and R. Wang
Two peptide ligands conjugated adenine, [9-N-(tritylmercapto acetyl diglycyl aminoethyl) adenine, Tr-MAG2-Ade] and [9-N-(tritylmercapto acetyl triglycyl aminoethyl) adenine, Tr-MAG3-Ade], are synthesized and labeled with 99mTc by directly labeling method. The stability of 99mTc-MAG2-adenine and 99mTc-MAG3-adenine in vitro is measured. The uptake radios of tumor to muscle at 3h post-injection are 5.70 and 4.92, respectively.
The biodistribution and scintigraphic imaging studies show that the two complexes have high localization in tumor and high
contrasted tumor images can be obtained, which suggest their potential utility as tumor imaging agents. But the high radioactivity
of abdomen could prevent the tumor imaging in this area.
Authors:C. Zhang, Y. Zhao, S. Feng, C. Qi, Z. Fu, F. Guo, and R. Wang
To increase the tumor uptake of Val-Gly-Gly (VGG), adenine was introduced into the peptide. N-mercaptoacetyl-VGG-adenine (MAVGG-adenine)
and MAVGG were labeled with 99mTc using a solution of SnCl2 and tartaric acid as reducing agent. Biodistribution in mice bearing the S180 tumor was measured and γ imaging was performed.
Compared with MAVGG, adenine conjugated MAVGG had higher tumor uptake and tumor to normal tissue ratios, which suggested that
the tumor uptake property of a peptide may be improved by introducing a nucleotide base. The high contrasted tumor images
of 99mTc-MAVGG-adenine also suggested its potential utility as tumor imaging agent.