Quantum dots (QDs) have more and more attention as a novel example of nanocrystals due to their unique fluorescent characteristics.
Recently, the toxicity and the potential environmental effects of QDs have become a research hotspot. In this work, in vivo endocrine disrupting effect, toxicokinetics and oxidative stress of QDs were characterized following the intraperitoneal
dosing in Chinese loaches. Vitellogenin (Vtg) levels induced by E2 decreased significantly when administrated with the mixture
of QDs and E2, which was consistent with the observations of histopathology in testes. The release of free Cd2+ from QDs and the non-specific adsorption of E2 by QDs might be the joint factors contributing to the inhibition of Vtg expression
induced by E2 in the male Chinese loaches. In the muscle, bone, intestines, blood and testis, CdSe QDs reached the maximal
concentration (Cmax) in approximately 1-h postinjection and subsequently presented downtrend with the prolonged time. Whereas, there were even
increasing tendencies of CdSe QDs’ concentrations in the liver and kidney. It is educible that CdSe QDs can be persistent
at least for 7 days, indicating the overall half-life of CdSe QDs in the fish body is very long. The measurement of hepatic
superoxide dismutase (SOD) activity and reduced glutathione (GSH) content indicate that QDs have smaller effects on the antioxidative
system of the organisms compared with free Cd2+ due to the effective prevention of the release of Cd by PEG coating of QDs. The comprehensive evaluation of QDs’ toxicity
in the present study provides an essential and general framework towards more focused research on the elucidation of the biological
effects of QDs in vivo. 相似文献
The extraction of strontium ions using DCH18C6 as the extractant and various ionic liquids (ILs) as solvents has been investigated.
The distribution ratio of Sr2+ can reach as high as 103 under certain conditions, much larger than that in DCH18C6/n-octanol system. The extraction capacity depends greatly on the structure of ionic liquids. In IIs-based extraction systems,
the extraction efficiency of strontium ions is reduced by increasing the concentration of nitric acid and can also be influenced
directly by the presence of Na+ and K+ in the aqueous phase. It is confirmed that the extraction proceeds mainly via a cation-exchange mechanism. 相似文献
The extraction of thorium(IV) was investigated using two types of W/O microemulsion,one of which was formed by a surface-active saponified extractant sodium bis(2-ethylhexyl) phosphate(NaDEHP) and the other was formed by a mixture of an anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate(AOT) and an extractant bis(2-ethylhexyl)phosphoric acid(HDEHP) as the cosurfactant.The extraction capacities of the above two systems were higher than that of the HDEHP extraction system.High concentration of NaNO 3 showed no influence on the extraction in the NaDEHP based W/O microemulsion system,whilst reduced the extractability in the AOT-HDEHP W/O microemulsion system.The mechanism in acidic condition was demonstrated by the log-log plot method.The structure of the aggregations and the water content in the organic phase after extraction were measured by dynamic light scattering and Karl Fischer water titration,respectively.It was found that NaDEHP based W/O microemulsion broke up after extraction,while AOT-HDEHP W/O microemulsion was reserved. 相似文献
The study of cyclodextrin nanotubes is a significant topic among the self-assembly behaviors of cyclodextrins. We report herein the interaction of 2,5-bis(5′-tert-butyl-2-benzoxazoyl)thiophene (BBOT) with α-, β-, γ-cyclodextrins (CDs). It has been discovered that the reaction patterns of BBOT with CDs are remarkably different. β-CD forms a simple inclusion complex with BBOT in a stoichiometry of 1:2 (guest:host). β-CD forms a 1:1 inclusion complex with BBOT at its low concentration. At higher concentration of BBOT, the nanotube and secondary assembly of β-CD are formed. As for γ-CD, the nanotube and secondary assembly are formed within the whole concentration range of BBOT studied. The structure of γ-CD nanotubes is different from that of β-CD nanotubes to a certain extent.
Quantum dots (QDs) have received more and more attention as a novel example of nanomaterials. Due to their unique fluorescent characteristics,quantum dots have been successfully applied in biotech-nology and medicine applications. Recently,the toxicity and the potential environmental effects of QDs have become a research hotspot. In this paper,toxicological effects of QDs are reviewed,and the prospects and research directions are given based on the analysis of this research field. 相似文献