Background Titanium dioxide nanoparticles (TiO 2 NPs) have recently found applications in a wide variety of consumer goods. TiO 2 NPs exposure significantly increases fetal deformities and mortality. However, the potential toxicity of TiO 2 NPs on the growth and development of placenta has been rarely studied during mice pregnancy. Purpose The objective of this study was to investigate the effects of maternal exposure of TiO 2 NPs on the placentation. Methods Mice were administered TiO 2 NPs by gavage at 0, 1 and 10 mg/kg/day from gestational day (GD) 1 to GD 13. Uteri and placentas from these mice were collected and counted the numbers of implanted and resorbed embryo and measured the placental weight on GD 13. Placental morphometry was observed by hematoxylin and eosin staining. The levels of Hand1, Esx1 , Eomes , Hand2 , Ascl2 and Fra1 mRNA were assessed by qRT-PCR. Uterine NK (uNK) cells were detected by using DBA lectin. Laminin immunohistochemical staining was to identify fetal vessels. Western blotting and transmission electron micrograph (TEM) were used to assess the apoptosis of placenta. Results No treatment-related difference was observed in the numbers of implanted and resorbed embryos and weight of placenta between the groups. However, 1 mg/kg/day TiO 2 NPs treatment significantly reduced the ratio of placenta/body weight on GD 13. The proportion of spongiotrophoblast in the 10 mg/kg/day dose group became higher than that in the control group, yet that of labyrinth was significantly lower in 10 mg/kg/day mice. The expression levels of Hand1 , Esx1 , Eomes , Hand2 , Ascl2 and Fra1 mRNA markedly decreased in TiO 2 NP treated placentas. Furthermore, TiO 2 NPs treatment impaired the formation of intricate networks of fetal vessels and reduced the number of uNK cells, and inhibited proliferation and induced apoptosis of placenta by nuclear pyknosis, the activation of caspase-3 and upregulation of Bax protein and downregulation of Bcl-2 protein on GD 13. Conclusion Gestational exposure to TiO 2 NPs significantly impairs the growth and development of placenta in mice, with a mechanism that seems to be involved in the dysregulation of vascularization, proliferation and apoptosis. Therefore, our results suggested the need for great caution while handling of the nanomaterials by workers and specially pregnant consumers.

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The composition of electrolyte affects to a great extent the electrochemical performance of vanadium redox flow batteries (VRB). The effects of Cr 3+ concentration in the anolyte on the electrode process of V(V)/V(IV) couple have been investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that Cr 3+ causes no side reactions, but affects the electrochemical performance of V(V)/V(IV) redox reaction, including the reaction activity, the reversibility of electrode reaction, the diffusivity of vanadium ions, the interface film impedance, and the electrode reaction impedance. The experimental results show that Cr 3+ within a certain concentration range can improve the reversibility of electrode reaction and the diffusion of vanadium ions. With the Cr 3+ concentration increasing from 0 to 0.30 g L −1, the reversibility of V(V)/V(IV) reaction increases, while the diffusion resistance decreases. Correspondingly, the diffusion coefficient of vanadium ions increases from (5.48-6.77) × 10 −7 to (6.82-8.44) × 10 −7 cm 2 s −1 , an increase of ~24%. However, the diffusion resistance increases and the diffusion coefficient decreases when Cr 3+ concentration is over 0.30 g L −1 , while the impedances of the interface, the film as well as the charge transfer increase continuously. As a result, Cr 3+ with a certain concentration improves the diffusion and mass transfer process, but the resistances of the film, the interface, and the charge transfer rise. Furthermore, Cr 3+ concentration of no more than 0.10 g L −1 has few effect on the electrode reaction process, and that of no more than 0.30 g L −1 is favorable to the diffusion of vanadium ions. Vanadium redox flow batteries (VRB), a high efficient and clean rechargeable device for energy conversion and storage, have promising prospects in the fields of generating electricity using renewable power sources, peak regulation of electric networks, emergency power, remote supply and electric vehicles. They have unique advantages such as high power density, excellent cycling stability, high reliability, simple operation and convenient maintenance [1]. The process of energy storage and release of VRB is generally achieved through an interconversion of soluble redox couples like V(V)/V(IV) and V(III)/V(II) in a electrolyte. Thus, the electrolyte is both the electroactive species and the reservoirs for energy storage, and has a determining influence on the electrochemical performance of VRB. The anolyte can be prepared directly by dissolving VOSO 4 in a dilute sulfuric acid solution [2]. However, it is usually prepared by dissolving V 2 O 5 in a dilute sulfuric acid with a reduction treatment because of the high cost of VOSO 4 [3]. V 2 O 5 is an intermediate product in the smelting process for producing steel in Pangang Group, but it usually contains small amounts of impurities, such as Cr 3+ , Mn 2+ ions, which exist also in the VOSO 4 prepared by using such V 2 O 5 . We have investigated the influence of Mn 2+ concentration on the electroc...

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A QuEChERS-type method without matrix interference was designed and developed to determine organophosphorus pesticide residues in edible vegetable oils, based on dispersive solid-phase extraction with cleanup using UiO-66 as sorbent. Microporous UiO-66 directly and selectively adsorbed organophosphorus pesticides and excluded interfering compounds. Clean analytes were obtained by elution and analyzed using gas chromatography–tandem mass spectrometry. The dispersive solid-phase extraction conditions (amount of adsorbent, extraction time, desorption solvent volume, and elution time) were optimized. The limits of detection of the pesticides in vegetable oils were 0.16–1.56 ng/g. Under optimized conditions, the average pesticide recoveries were 81.1–113.5%. The intraday and interday relative standard deviations for analyte recovery were <8.2 and <13.9%, respectively. Thus, the method is reliable and could detect organophosphorus pesticide residues in edible vegetable oils. Furthermore, UiO-66 can be easily recycled and reused at least 10 times, reducing the cost of analysis.