Flotation separation of scheelite from calcite using luteolin as a novel depressant

This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)system.The suitability of LUT as a calcite depressant is confirmed through micro-flotation testing.At pH=9,with LUT concentration of 50 mg·L^(-1) and NaOL concentration of 50 mg·L^(-1),scheelite recovery reaches 80.3%.Calcite,on the other hand,exhibits a recovery rate of 17.6%,indicating a significant difference in floatability between the two minerals.Subsequently,the surface modifica-tions of scheelite and calcite following LUT treatment are characterized using adsorption capacity testing,Zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and atomic force microscopy(AFM).The study in-vestigates the selective depressant mechanism of LUT on calcite.Adsorption capacity testing and Zeta potential analysis demonstrate sub-stantial absorption of LUT on the surface of calcite,impeding the further adsorption of sodium oleate,while its impact on scheelite is min-imal.FT-IR and XPS analyses reveal the selective adsorption of LUT onto the surface of calcite,forming strong chemisorption bonds between the hydroxyl group and calcium ions present.AFM directly illustrates the distinct adsorption densities of LUT on the two miner-al types.Consequently,LUT can effectively serve as a depressant for calcite,enabling the successful separation of scheelite and calcite.

Nano-CaO_(2)Promotes the Release of Carbon Sources from Municipal Sludge and the Preparation of Double-Network Hydrogels with High Swelling Ratios

In this study,hydrogels were prepared from municipal sludge to recycle and realize the value-added utilization of the carbon components in this abundant waste material.The carbon sources were extracted from the municipal sludge using synthesised nano CaO_(2)as an oxidant,and the carbon sources were graft copolymerised with acrylic acid monomer using N,N′-methylenebisacrylamide as a crosslinking agent and ammonium persulfate as an initiator.The factors influencing the hydrogel preparation were investigated by single-factor experiments.Based on the results of the single-factor experiments,a hydrogel with a swelling ratio of up to 19768.4%at 12 h was prepared with an oxidant dosage of 0.20 g,a monomer dosage of 5.8 g,a neutralisation degree of the monomer of 70%,an initiator dosage of 0.15 g,and a crosslinking agent dosage of 0.15 g.The hydrogel preparation conditions were optimized using the response surface method,and the interactions between the different reaction conditions were analysed to obtain the best preparation conditions.X-ray diffraction results showed that hydrogels were amorphous in structure.Scanning electron microscopy images showed that the SiO_(2)particles from the sludge acted as crosslinking points between different layers of hydrogel chains.The crosslinking polymerisation and crosslinking agent worked together to form hydrogels with an inorganic-organic double network structure,and this structure was highly stretchable,resulting in hydrogels with good swelling properties.

Two-photon AIE probe conjugated theranostic nanoparticles for tumor bioimaging and pH-sensitive drug delivery

Nanoparticles armed with chemotherapy drug and fluorescence probe have become an effective anticancer strategy for their advantages in cancer diagnosis and treatment.However,fluorophore for diagnostic medicine with deep penetration depth and high resolution are still very rare,while rational designs are also required to improve the tumor retention and target-site drug delivery.Herein,a two-photon fluorophore with aggregation-induced emission and large two-photon absorption cross-section has been designed for two-photon bioimaging,and a novel theranostic nanoplatform is also constructed based on doxorubicin and the two-photon fluorophore conjugated copolymer,P(TPMA-co-AEMA)-PEI(DA)-Blink-PEG (PAEEBlink-DA).The micelles maintain a “stealth” property during blood circulation and is activated in the acidic tumor microenvironment,which triggers the charge-conversion and results in enhanced micellar internalization.Meanwhile,PAEMA chains can convert from hydrophobicity to hydrophilicity with accelerated drug release and particle size expansion.The enlarged particle size would potentially extend the retention time of these micelles.Moreover,a great AIE active two-photon bioimaging with tissue penetration depth up to 150 μm is observed and the in vivo biodistribution of nanoparticles can be traced.The in vivo antitumor results further indicate the obvious reduction of adverse effect and enhanced treatment effect of these micelles,proving that these PAEEBlink-DA micelles would be a potential candidate for tumor theranostic applications.

Liver X receptorβis required for the survival of single-positive thymocytes by regulating IL-7Rαexpression

Liver X receptors(LXRs)are known as key transcription factors in lipid metabolism and have been reported to play an important role in T-cell proliferation.However,whether LXRs play a role in thymocyte development remains largely unknown.Here,we demonstrated that LXRβdeficiency caused a reduction in single-positive(SP)thymocytes,whereas the transitions from the double-negative to SP stage were normal.Meanwhile,LXRβ-null SP thymocytes exhibited increased apoptosis and impairment of the IL-7Rα-Bcl2 axis.In addition,the LXR agonist T0901317 promoted the survival of SP thymocytes with enhanced IL-7Rαexpression in wild-type mice but not in LXRβ-deficient mice.Mechanistically,LXRβpositively regulated the expression of IL-7Rαvia direct binding to the Il7r allele in SP thymocytes,and forced expression of IL-7Rαor Bcl2 restored the survival of LXRβ-defective SP thymocytes.Thus,our results indicate that LXRβfunctions as an important transcription factor upstream of IL-7Rαto promote the survival of SP thymocytes.

Constructing bimodal nanoprobe based on Gd:AgInS_(2)/ZnS quantum dots for fluorometric/magnetic resonance imaging in mesenchymal stem cells

Mesenchymal stem cells(MSCs)hold great promise in regenerative medicine and received overwhelm-ing concerns to promote their therapeutic effects.Owing to the shortage of MSCs-specific biomarkers,bimodal imaging nanoprobes with integrated complementary information are of great importance in ameliorating the efficacy of MSCs terminal tracking.In this study,a noninvasive dual-mode imaging nanoprobe with enhanced detection sensitivity and spatial resolution based on alloyed Gd:AgInS_(2)/ZnS quantum dots(QDs)was first fabricated through a microwave-assisted heating method.The QDs with red emissive fluorescence exhibit excellent biocompatibility in MSCs under a confocal microscope.As for magnetic resonance imaging(MRI),the longitudinal relaxation rate of 11.1420 mM^(-1) S^(-1) of Gd:AgInS_(2)/ZnS QDs was achieved,which was 1.7 times higher than that of commercial MRI contrast agent(6.4667 mM^(-1) S^(-1)).Furthermore,the cellular internalization of Gd:AgInS_(2)/ZnS QDs exerts no significant effect on the adipogenesis of MSCs and is conducive to the observation of further adipogenic differentiation.Our work helps to verify the promising prospect to develop a bimodal nanoprobe of fluorescence/MRI based on Gd:AgInS_(2)/ZnS QDs,which could monitor the differentiation and migration of MSCs for further therapeu-tic approach.

Waste sludge disintegration, methanogenesis and final disposal via various pretreatments: Comparison of performance and effectiveness

This study compared the three wastewater pretreatments of ozonation,Fe2þ-S2O82and freeze-thawing(F/T)in the disintegration,anaerobic digestion(AD)and final disposal of the sludge.The F/T pretreatment increased the dewaterability and settleability of the sludge by 7.8%and 47.1%,respectively.The ozonation pretreatment formed more volatile fatty acids(VFAs),with a peak value of 320.82 mg SCOD/L and controlled the release of sulfides.The Fe2þ-S2O82pretreatment removed heavy metals through the absorption and flocculation of ferric particles formed in-situ.During the anaerobic digestion of the sludge,the ozonation pretreatment accelerated the hydrolysis rate(k)rather than the biochemical methane potential(B0)of the sludge due to the high VFA content in the supernatant.Comparatively,the F/T pretreatment facilitated the B0 with great economic efficiency by enhancing the solubilisation of the sludge.Although Fe2þ-S2O82pretreatment decreased the methane production,the ferric particle was a unique advantage in the disintegration and harmless disposal of the sludge.The digested sludge had more VFAs after ozonation pretreatment,which contributed to the recycling of carbon.In addition,the lower sludge volume could save the expense of transportation and disposal by ozonation pretreatment.Different pretreatments had different characteristics.The comparative study provided information allowing the selection of the type of pretreatment to achieve different objectives of the treatment and disposal of sludge.