A simple chromatographic method to separate carrier-free60Co and54Mn, produced in the neutron irradiation of Fe2O3, has been developed. The separation of carrier-free60Co was performed in the displacement mode using DTPA as a displacer and H+ as a barrier ion; carrier-free54Mn was separated in the form of54MnO
from55+59Fe in the elution mode using HNO3 as an eluent.
One of the most dramatic economic transformations in modern times has been the entry of women into the labor force. The purpose of this study is to address issues related to interactions among gender differences, economic growth and education with endogenous physical and human capital accumulation. Our model is a synthesis of the Solow model (Solow 1956) and the Uzawa-Lucas two-sector growth model (Uzawa 1965; Lucas 1988) with Zhang’s approach to household behavior (Zhang 1993). It adds gender issues to the traditional models. We examine behavior of the economy by simulation. We demonstrate the existence of equilibrium points and plot the motion of the dynamic system. We also examine the effects of changes on the time distributions and human capital of man and woman in the propensity to receive education, the efficiency of learning, the efficiency of education, and the propensity to save upon dynamic paths of the system.
Chronic hepatitis B virus (HBV) carriers may develop hepatocellular carcinoma (HCC) by a wide range of mechanisms including angiogenesis. We show that HBV replication induces the expression of angiogenic proteins interleukin 6 (IL6) and cyclooxygenase-2 (Cox2). Interestingly, ibuprofen (a Cox2 inhibitor) is found to attenuate the levels of IL6 and Cox 2 which are induced by HBV replication.
The mechanism of attenuation of angiogenic proteins by ibuprofen was further investigated. Our results show that HBx is involved in the increase of the expression of Cox2 through the NFκB pathway. However, the expression of Cox2 is decreased when the HBx-expressing cells are incubated with ibuprofen. The contrasting effect of HBx on Cox2 is found to be determined by differential dimer formation among the members of the NFκB family of proteins, including NFκB, RelA, and C-rel. Specifically, HBx alone results in dimer formation between NFκB and RelA, while the combined presence of HBx and ibuprofen leads to the formation of NFκB and C-rel. Additional information on the interaction network involving HBx, ibuprofen, and NFκB pathways is revealed by two-dimensional liquid chromatography-tandem mass spectrometry proteomics analysis. Taken together, our findings provide new insights on the angiogenesis induced by HBV replication.
Nanoscience and technology (NST) is a young scientific and technological field that has generated great worldwide interest
in the past two decades. Previous bibliometric analyses have unmistakably demonstrated the remarkable growth of the global
NST literature. While almost all published research articles in NST are in English, increasingly a larger share of NST publications
is published in the Chinese language. Perplexingly, Chinese is the only language — apart from English — that displays an ascendant
trend in the NST literature. In this brief note, we explore and evaluate three arguments that could explain this phenomenon:
coverage bias, language preference, and community formation.
To separate minor actinides from HLLW by extraction chromatography, a few novel silica-based di(2-ethylhexyl)phosphoric acid (HDEHP), 4,4¢,(5¢)-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6), octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO), and N,N,N¢,N¢-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) polymeric adsorption materials (HDEHP/SiO2-P, DtBuCH18C6/SiO2-P, CMPO/SiO2-P, and TODGA/SiO2-P) were synthesized by impregnating HDEHP, DtBuCH18C6, CMPO, and TODGA into the pores of porous SiO2-P particles, which were the new kind of inorganic/organic composites consisted of macroporous SiO2 and copolymer. The bleeding behavior of these composites was investigated by examining the effect of contact time and HNO3 concentration. It was found that in the tested HNO3 concentration range, a noticeable quantity of DtBuCH18C6, at least 600 ppm, leaked out from DtBuCH18C6/SiO2-P because of the protonation of DtBuCH18C6 with hydrogen ion, while the others were lower and basically equivalent to the solubility of HDEHP, CMPO, or TODGA in corresponding acidities solutions. Based on the batch experiment, the bleeding of CMPO/SiO2-P and TODGA/SiO2-P, the main adsorbents used in MAREC process for HLLW partitioning, was evaluated by column operation in 0.01M HNO3 and 3M HNO3. The quantity of CMPO leaked was ~48 ppm in 0.01M HNO3 and ~37 ppm in 3.0M HNO3. The bleeding of TODGA decreased from 23.2 ppm to 7.27 ppm at the initial stage and then basically kept constant. An actual bleeding of TODGA was evaluated by the separation of Sr(II) from a 2.0M HNO3 solution containing 5.0 . 10-3M of 6 typically simulated elements.
To optimize the hydration process of blended cement, cement clinker and supplementary cementitious materials (SCMs) were ground and classified into several fractions. Early hydration process of each cementitious materials fraction was investigated by isothermal calorimeter. The results show fine cement clinker fractions show very high hydration rate, which leads to high water requirement, while fine SCMs fractions present relatively high hydration (or pozzolanic reaction) rate. Cement clinker fractions in the range of 8–24 μm show proper hydration rate in early ages and continue to hydrate rapidly afterward. Coarse cement clinker fractions largely play “filling effect” and make little contribution to the properties of blended cement regardless of their hydration activity (or pozzolanic activity). The hydration process of blended cement can be optimized by arranging high activity SCMs, cement clinker, and low activity SCMs in fine, middle, and coarse fractions, respectively, which not only results in reduced water requirement, high packing density, and homogeneous, dense microstructure, but also in high early and late mechanical properties.
Owing to poor bonding between coarse fly ash particles and hydration products, gap-graded blended cements with fly ash usually show lower compressive strengths than Portland cement. Surface cementitious properties of coarse fly ash were improved by dehydration and rehydration processes in the present study. The results show that during the calcination at 750 °C, C–S–H gel is mainly transformed into a new nesosilicate, which is similar to a less crystalline C2S. The formation of melilite from hydration products is also noticed at 900 °C, however, this will not contribute to rehydration of calcined fly ash. Rehydration of new generated nesosilicate on the surface of coarse fly ash leads to a better bonding between coarse fly ash particles and hydration products. As a result, both early and late mechanical properties of gap-graded blended cements containing 25% cement clinker and 39% calcined coarse fly ash are higher than those of 100% Portland cements.
Authors:Zhang Yuanxun, Zhang Yongping, Li Delu, Zhang Guilin, Long Jiangang, Shen Hui, Huang Yuying, and He Wei
In order to explore the interaction between the expression of ZnT3 (Zinc Transporter 3) mRNA (Messenger Ribonucleic Acid)
and the concentration of elemental zinc in mouse brain, zinc distribution in brain was determined by synchrotron radiation
X-ray fluorescence (SRXRF) technique and a ZnT3 mRNA expression in tissue was examined by the reverse-transcriptase polymerase
chain reaction (RT-PCR) method.The results show that the zinc concentration is not evenly distributed in brain slices. Its
concentrations in cerebral cortex and hippocampus are nearly 5-10 times higher than those in other positions. A corresponding
relation is that ZnT3 mRNA in cerebral cortex, hippocampus and testis has higher abundant degree, but it is not examined out
in other tissues. Furthermore, the results promote that ZnT3 facilitates the accumulation of zinc in synaptic vesicles and
may play an important role in structuring of vesicular zinc pool.
Authors:Liqin Liu, Guangrong Zhong, Yaqian Wei, Min Zhang, and Xuebin Wang
A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with aminomethylenediphosphonic acid (AMDP) was synthesized through
a multiple-step reaction. HYNIC–AMDP could be labeled easily and efficiently with 99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) as coligand to form the 99mTc–HYNIC–AMDP complex in high yield (> 95%). Its partition coefficient indicated that it was a good hydrophilic complex. The
biodistribution studies of 99mTc–HYNIC–AMDP in normal ICR mice showed that this complex had high bone uptake and low or negligible accumulation in non-target
organs. As compared with 99mTc–MDP, 99mTc–HYNIC–AMDP had a higher bone uptake and the ratios of bone/blood and bone/muscle at early time after injection, suggesting
that it could be potentially useful for bone imaging at an earlier time after injection according to further investigations
of the biological behavior of this complex.
Authors:Cuiying Li, Wei Zhang, Bo Zhao, Mei Liang, and Canhui Lu
In this study, the solid-state shear pan-milling was employed to prepare a series of polymer/layered silicate (PLS) nanocomposites. During the process of pan-milling at ambient temperature, poly(vinyl alcohol)/organic montmorillonite (PVA/OMMT) can be effectively pulverized, resulting in coexistence of intercalated and exfoliated OMMT layers. The obtained PLS nanocomposites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM analysis indicated that OMMT dispersed homogeneously in PVA matrix and XRD results illustrated that pan-milling had an obvious effect on increase in the interlayer spacing of OMMT, and resulted in coexistence of intercalated and exfoliated OMMT layers formed. Thermal gravimetric analysis showed that thermal stability of PVA was improved owing to the incorporation of OMMT. Thermal decomposition kinetics of PVA/OMMT nanocomposites with different milling cycles of OMMT was also studied. Two types of OMMT are chosen to compare the effect of hydrophilicity of OMMT on PVA/OMMT nanocomposites.