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111.
Goveia D Rosa AH Bellin IC Lobo FA Fraceto LF Roveda JA Romão LP Dias Filho NL 《Analytical and bioanalytical chemistry》2008,390(4):1173-1180
This work involved the development and application of a new analytical procedure for in-situ characterization of the lability
of metal species in aquatic systems by using a system equipped with a diffusion membrane and cellulose organomodified with
p-aminobenzoic acid groups (DM-Cell-PAB). To this end, the DM-Cell-PAB system was prepared by adding cellulose organomodified
with p-aminobenzoic acid groups (Cell-PAB) to pre-purified cellulose bags. After the DM-Cell-PAB system was sealed, it was examined
in the laboratory. The in-situ application involved immersing the DM-Cell-PAB system in two different rivers, enabling us
to study the relative lability of metal species (Cu, Cd, Fe, Mn, and Ni) as a function of time and quantity of exchanger.
The procedure is simple and opens up a new perspective for understanding environmental phenomena relating to the complexation,
transport, stability, and lability of metal species in aquatic systems rich in organic matter. 相似文献
112.
Corr SA Byrne SJ Tekoriute R Meledandri CJ Brougham DF Lynch M Kerskens C O'Dwyer L Gun'ko YK 《Journal of the American Chemical Society》2008,130(13):4214-4215
Using a one-step procedure we have prepared magnetic fluids comprising of polyelectrolyte stabilized magnetite nanoparticles. These nanocomposites are comprised of linear, chain-like assemblies of magnetic nanoparticles, which can be aligned in parallel arrays by an external magnetic field. We have shown the potential use of these materials as contrast agents by measuring their MR response in live rats. The new magnetic fluids have demonstrated good biocompatibility and potential for in vivo MRI diagnostics. 相似文献
113.
Gautier A Juillerat A Heinis C Corrêa IR Kindermann M Beaufils F Johnsson K 《Chemistry & biology》2008,15(2):128-136
The visualization of complex cellular processes involving multiple proteins requires the use of spectroscopically distinguishable fluorescent reporters. We have previously introduced the SNAP-tag as a general tool for the specific labeling of SNAP-tag fusion proteins in living cells. The SNAP-tag is derived from the human DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) and can be covalently labeled in living cells using O6-benzylguanine derivatives bearing a chemical probe. Here we report the generation of an AGT-based tag, named CLIP-tag, which reacts specifically with O2-benzylcytosine derivatives. Because SNAP-tag and CLIP-tag possess orthogonal substrate specificities, SNAP and CLIP fusion proteins can be labeled simultaneously and specifically with different molecular probes in living cells. We furthermore show simultaneous pulse-chase experiments to visualize different generations of two different proteins in one sample. 相似文献
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检验分子晶体非线性光学极化率的可加性,对于确认有向气体模型(Oriented-Gas Model) 具有重要的科学意义,对探索新型实用的分子非线性光学材料也有实际的意义。本文对尿素晶体中分子簇非线性光学极化率的可加性做了详尽的理论研究。首次做到了尿素分子最近邻排布团簇的非线性光学极化率的从头算,从而扩展了前人的工作。研究结果有效地确认了有向气体模型。同时,我们还提出了壳层结构模型 (Shell-Structure Model),用以解决有向气体模型中的缺陷,可实现更为有效可靠地计算晶体宏观非线性光学系数。 相似文献
118.
Could the New Absorption Cross Section of J/ψ Change the Aspect of Nuclear Absorption Mechanism
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The enlarged new absorption cross sections of J/ψ by π and ρ were put into the hadron and string cascade model, JPCIAE, and the J/ψ suppression factors in P-A, O-U, S-U and Pb-Pb minimum bias collisions at 200A GeV/c were calculated with nuclear absorption mechanism only. The results seem to indicate that, with new enlarged cross section it is still hard to change the aspect that nuclear absorption mechanism itself could not easily account for the J/ψ anomalous suppression in Pb-Pb collisions. 相似文献
119.
Qian Rong LI* Ting Hu ZHANG Robert S.WARD Structure Research Laboratory University of Science Technology of China Hefei Chemistry Department University of Wales Swansea Singleton Park Swansea SA PP UK 《中国化学快报》2001,(12)
Introduction 2, 3-Dichloro-5, 6-dicyanobenzoquinone (DDQ) can react with lignans of the mono- arylidene-butyrolactone1, aryltetralin2, dibenzylbutane3 and aryltetralin-butyrolactone4,5 series. We have studied the reactions of this reagent with podophyllotoxin 1, which is a well-known natural product on account of its long history of use in folk medicine and the biological activity of its many derivatives6. In particular, derivatives of 4-demethyl epipodophyllotoxin are used in cancer chemo… 相似文献
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