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Zircon is a critical mineral for the extraction of zirconium, uranium and hafnium. Physical separation techniques like gravity and electrical separation have been widely used to obtain a commercial-grade zircon. Flotation, as a supplementary approach, can be used to separate fine zircon from heavy minerals (i.e. rutile, cassiterite). However, it is challenging to selectively recover iron/aluminosilicate contaminated zircon, due to its low floatability. In this study, two zircon samples containing high and low amounts of impurities were selected in order to determine the influence of surface composition on flotation. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), speciation diagrams, and zeta-potentials demonstrated that pretreatment methods can improve the surface purity of zircon via the removal of coated impurities (iron-oxides and aluminosilicates) as well as increasing the exposure of the ZrO2 and ZrSiO4 phases. SEM, XPS, zeta-potential and flotation studies performed with sodium oleate (NaOL) as an environmentally benign collector show that the pretreated zircon samples display better flotation performance than the untreated zircon. First-principle calculations revealed that the chemical bond between NaOL and zircon is ionic in nature; NaOL can be both chemically and physically adsorbed onto zircon surfaces. Adsorption is mainly affected by electrostatic attractions reflected by changes in the zeta-potential. Surface pretreatment can thus substantially improve the flotation performance of zircon. Refereed/Peer-reviewed

Parkinson's disease is a common progressive neurodegenerative disease, and presently has no curative agent. Curcumin, as one of the natural polyphenols, has great potential in neurodegenerative diseases and other different pathological settings. The brain-derived neurotrophic factor (BDNF) and phosphatidylinositol 3 kinase (PI3k)/protein kinase B (Akt) signaling pathways are significantly involved nerve regeneration and anti-apoptotic activities. Currently, relevant studies have confirmed that curcumin has an optimistic impact on neuroprotection via regulating BDNF and PI3k/Akt signaling pathways in neurodegenerative disease. Here, we summarized the relationship between BDNF and PI3k/Akt signaling pathway, the main biological functions and neuroprotective effects of curcumin via activating BDNF and PI3k/Akt signaling pathways in Parkinson's disease. This paper illustrates that curcumin, as a neuroprotective agent, can delay the progression of Parkinson's disease by protecting nerve cells.

This article has been withdrawn at the request of the author for the following reason. Recently, we found an experimental error in this study. The results of dual-luciferase reporter assay in Fig. 5G and 5F may be incorrect. We conducted the experiment again, and found that the luciferase activity didn’t reduced by miR-149-5p in FGF5-wt group. The results were showed as below. So whether miR-149-5p directly targets FGF5 is uncertain. Therefore, we decide to withdraw the manuscript. We are very sorry for the trouble. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal

In this paper we first compute the out-of-time-order correlators (OTOC) for both a phenomenological model and a random-field XXZ model in the many-body localized phase. We show that the OTOC decreases in power law in a many-body localized system at the scrambling time. We also find that the OTOC can also be used to distinguish a many-body localized phase from an Anderson localized phase, while a normal correlator cannot. Furthermore, we prove an exact theorem that relates the growth of the second R\'enyi entropy in the quench dynamics to the decay of the OTOC in equilibrium. This theorem works for a generic quantum system. We discuss various implications of this theorem., Comment: 6 pages, 3 figures, published version