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• Ruthenium nanoparticles incorporated in mesoporous carbon are reported for production of γ-valerolactone. • The incorporated catalysts demonstrate excellent reusability and thermal stability. • Leaching can be minimised by tailoring the mesoporous structure. • The mechanism of high reusability and thermal stability for incorporated ruthenium catalysts are studied. The hydrogenation of levulinic acid to γ-valerolactone with water as solvent is a crucial reaction for producing fine chemicals. However, the development of highly stable catalysts is still a major challenge. Here, we prepared a Ru nanoparticles incorporated in mesoporous-carbon (Ru-MC) catalyst to achieve high stability in acidic aqueous medium. The Ru-MC showed excellent catalytic performance (12024 h−1 turnover frequency) in the hydrogenation of LA-to-GVL. Compared with Ru supported on mesoporous carbon catalyst (Ru/MC) prepared by conventional wet impregnation method, the Ru-MC showed excellent reusability (more than 6 times) and thermal stability (up to 600 °C). Based on H 2 -TPR-MS characterization, it was proposed that the incorporated structure significantly increased the interaction between Ru nanoparticles and carbon support, which effectively prevent the leaching and sintering of Ru nanoparticles and contributed to increased high reusability and thermal stability of the Ru-MC. [ABSTRACT FROM AUTHOR]

Abstract: A porous polysulfone microcapsule containing organic modified montmorillonite and magnetic nanoparticles (OMMT-Fe3O4@PSF) has been successfully prepared by a phase-inversion method and evaluated as a magnetic solid-phase extraction (MSPE) sorbent for clean-up and enrichment of 4-chlorophenol (4-CP) and 2-chlorophenol (2-CP) in aqueous samples. Compared with a microcapsule containing the conventional extraction sorbent C18 (C18-Fe3O4@PSF), OMMT-Fe3O4@PSF had much lower cost, a faster adsorption rate, and superior uptake amounts for the investigated analytes. The proposed microcapsule has been developed for the extraction of 4-CP and 2-CP from environmental water samples and their analysis by high-performance liquid chromatography with UV detection (HPLC-UV). Various parameters, such as pH, extraction time, the mass of sorbent, and the desorption conditions, have been evaluated and the calibration curves of the chlorophenols were linear (R 2 ≥0.9985) in the range from 1.01 to 104.5ngmL−1. The limits of detection at a signal-to-noise (S/N) ratio of 3 were 0.22 and 0.17ngmL−1 and the limits of quantification calculated at S/N=10 were 1.52 and 1.07ngmL−1 for 2-CP and 4-CP, respectively. The recoveries of 2-CP and 4-CP from natural water and the treated wastewater samples were in the range of 84.4–115% with relative standard deviations (RSDs) lower than 7.0%. The results have demonstrated the suitability of the MSPE approach for the analysis of trace chlorophenols in aqueous samples. [Copyright &y& Elsevier]

Abstract: The effects of titanium dioxide (TiO2) nanoparticles (NPs) on the differentiation of neural stem cells are reported. Our findings indicate that TiO2 NPs lead to a differentiational tendency towards neurons from neural stem cells, suggesting TiO2 NPs might be a beneficial inducer for neuronal differentiation. To insight into the possible molecular mechanism of the neuronal differentiation, we conducted a protein–protein interaction network (PIN) analysis. To this end, a global mapping of target proteins induced by TiO2 NPs was first made by a 2-dimensional electrophoresis analysis. Results showed that 9 proteins were significantly changed and then they were subjected to the mass spectrometric assay. All 9 identified proteins are involved in signal, molecular chaperones, cytoskeleton, and nucleoprotein. Further, based on our experimental data and DIP, IntAct–EBI, GRID database, a protein–protein interaction network was constructed, which provides highly integrated information exhibiting the protein–protein interaction. By analysis of the gene expression, the signal pathway involving Cx43 phosphorylation, which is negatively regulated by the protein kinase C epsilon (PKCɛ), is demonstrated. It is inferred that PKCɛ plays a pivotal negative role in the neuronal differentiation of stem neural cells in response to the TiO2 NPs exposure. [Copyright &y& Elsevier]

Abstract: ZnO nanoparticles (NPs) have been successfully synthesized by the chemical precipitation method in different atmospheres at 500°C. The annealing atmospheres were argon, forming gas (50% Ar/50% O2) and air, respectively. The effects of annealing atmosphere on the structure and optical properties of ZnO NPs were investigated in detail by X-ray diffraction, transmission electron microscope, photoluminescence and Raman scattering measurements. The results showed that the as-prepared ZnO NPs had a hexagonal wurtzite structure, and all the samples kept the overall crystal structure of bulk ZnO. From the Raman and photoluminescence spectra, it can be seen that the content of oxygen in different annealing atmospheres strongly influenced the crystallization and light emission of the ZnO NPs. The results revealed that the content of oxygen in air was the optimal condition for growing the ZnO NPs with the best crystalline quality and optical properties. Defect emission was significantly enhanced by annealing in Ar atmosphere, which indicated that the green defect emission was most likely due to oxygen vacancy. Moreover, the effect mechanism of annealing atmospheres on the structure and optical properties of ZnO NPs were also investigated. [Copyright &y& Elsevier]

To raise photocatalytic efficiency of ZnS nanoparticles (ZnS NPs) under visble light, the novel Ti 3 C 2 Tix (MXene) material was used to modify ZnS NPs through ultrasonic oscillation. Research results showed that ZnS nanoparticles (ZnS NPs) were successfully attached on layered MXene sheet, and the resultant 0.1ZnS NPs/MXene (0.1ZnS/M) sample exhibited very high photocatalytic performance under visible light. The degraded velocity of 0.1ZnS/M sample is about 0.02464 min−1, in which is as 3.2 times as that of pure ZnS (0.0077 min−1). Moreover, 0.1 ZnS/M sample displayed good hydrogen production yield about 212 μmol h−1. The enhanced catalytic performance was attributed to the excellent property of MXene sheets and the effective interaction between ZnS NPs and MXene sheets. • ZnS/MXene (ZnS/M) hybrids were fabricated by ultrasonic oscillation. • ZnS/MX hybrids exhibited high photocatalytic activity under visible-light. • ZnS/M hybrids displayed good photocatalytic hydrogen production ability. • MXene can enhance the photocatalytic activity of ZnS nanonanoparticles. [ABSTRACT FROM AUTHOR]

• A in-situ growth of CNTs strategy is used to trigger perovskite electrocatalysts. • The optimal perovskite exhibits a remarkably enhanced catalytic performance on HER. • The interaction between CNTs and perovskite modifies the electrochemical activity. The naturally scarce and costly precious metal as catalysts for electrochemical water electrolysis have prevent the large-scale applications in the transition of this technology. Therefore, it is emergency to explore for much cheaper and superior active scalable materials in making this technology to be more promising. The perovskite oxides, with rich constitutions and structures, can be easily to tune of the electrocatalytic applications by tailoring compositions. Herein, a highly efficient catalyst composed of nitrogen-doped carbon coated multi-metals core decorated Ruddlesden-Popper type structure (Pr 0.4 Sr 0.6) 3 (Fe 0.85 Nb 0.15) 2 O 7 (NC-CF-PSFN) compounds is synthesized via a in situ growth of carbon nanotubes treatment that trigger their catalytic activities. The optimal electrocatalyst exhibits a significantly enhanced electrocatalytic activity for hydrogen evolution reaction (HER) by affording an overpotential of 124 mV at the current density of 10 mA cm−2, an onset potential of –12 mV vs. RHE, accompanied by an outstanding durability in acidic media, outperforming that of perovskite-based catalysts. The optimized internal/external interaction between the complex carbon and perovskite phases would contribute to modify its electrochemical performance. This protocol highlights a novel strategy to prepare excellent perovskite materials for applications in energy generation and storage. [ABSTRACT FROM AUTHOR]

Visible light-induced polarization-dependent photochemical deposition of silver nanoparticles (AgNPs) has been demonstrated using Mn-doped congruent LiNbO3 (CLN) single crystals. Mn-doped CLN has a strong absorption over a wide region of the visible spectrum that allowed effective visible light irradiation for photochemical deposition. The AgNPs deposition on Mn-doped CLN was compared with that on non-doped congruent LiNbO3, and together these further confirmed that the photochemical deposition on LiNbO3 is caused by the strong photogalvanic effect. [ABSTRACT FROM AUTHOR]

Metallic nanoparticle deposition from an aqueous solution onto the +Z surfaces of LiNbO3 nanodomain patterns has been demonstrated. The distribution of the selectively deposited Ag particles was uniform and their sizes were 2–10 nm both in the diameter and height. The authors have inferred the mechanism by which the photovoltaic effect causes Ag particles to be deposited selectively on the +Z surfaces. The photovoltaic current density and the ferroelectric crystal thickness are found to be fundamental parameters of the photocatalytic deposition. [ABSTRACT FROM AUTHOR]

Strategies to enhance survival and direct the differentiation of stem cells in vivo following transplantation in tissue repair site are critical to realizing the potential of stem cell-based therapies. Here we demonstrated an effective approach to promote neuronal differentiation and maturation of human fetal tissue-derived neural stem cells (hNSCs) in a brain lesion site of a rat traumatic brain injury model using biodegradable nanoparticle-mediated transfection method to deliver key transcriptional factor neurogenin-2 to hNSCs when transplanted with a tailored hyaluronic acid (HA) hydrogel, generating larger number of more mature neurons engrafted to the host brain tissue than non-transfected cells. The nanoparticle-mediated transcription activation method together with an HA hydrogel delivery matrix provides a translatable approach for stem cell-based regenerative therapy. [ABSTRACT FROM AUTHOR]

This study investigated the preparation and mechanical performance of graphene/metal composites using Ni nanoparticles decorated graphene nanoplatelets (Ni-GPLs) as a reinforcing component in Cu matrix (Ni-GPL/Cu). Ni-GPLs consisting of well-dispersed Ni nanoparticles strongly attached on GPLs were successfully synthesized by chemically reducing Ni ions on the surface of GPLs. The Ni-GPL/Cu composites with only 0.8 vol% Ni-GPLs exhibited a significant improvement in ultimate tensile strength (UTS), being 42 % higher than that of monolithic Cu. The significant strength enhancement is attributed to the unique structure of Ni-GPLs, which was expected to generate a good dispersion and strong GPL-Cu interfacial bonding. The UTS of 0.8 vol% GPL/Cu composites was even lower than that of the monolithic Cu due to the GPL aggregates. The obtained results indicated that Ni-GPLs are novel and effective reinforcing components for greatly improving the mechanical properties of the graphene/metal composites. [ABSTRACT FROM AUTHOR]

Abstract: The nearly monodisperse starch capped CdSe nanoparticles were successfully synthesized by a simple and “green” route at room temperature. The as-prepared nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV–vis absorption and photoluminescence (PL) spectra. The XRD analysis showed that the starch capped CdSe nanoparticles were of the cubic structure, the average particle size was calculated to be about 3nm according to the Debye–Scherrer equation. TEM micrographs exhibited that the starch capped CdSe nanoparticles were well dispersed than the uncapped CdSe nanoparticles, the mean particles size of the capped CdSe was about 3nm in the TEM image, which was in good agreement with the XRD. [Copyright &y& Elsevier]

Strong metal–support interaction (SMSI) has gained great attention in the field of heterogeneous catalysis. However, whether single‐atom catalysts can exhibit SMSI remains unknown. Here, we demonstrate that SMSI can occur on TiO2‐supported Pt single atoms but at a much higher reduction temperature than that for Pt nanoparticles (NPs). Pt single atoms involved in SMSI are not covered by the TiO2 support nor do they sink into its subsurface. The suppression of CO adsorption on Pt single atoms stems from coordination saturation (18‐electron rule) rather than the physical coverage of Pt atoms by the support. Based on the new finding it is revealed that single atoms are the true active sites in the hydrogenation of 3‐nitrostyrene, while Pt NPs barely contribute to the activity since the NP sites are selectively encapsulated. The findings in this work provide a new approach to study the active sites by tuning SMSI. [ABSTRACT FROM AUTHOR]

Strong metal–support interaction (SMSI) has gained great attention in the field of heterogeneous catalysis. However, whether single‐atom catalysts can exhibit SMSI remains unknown. Here, we demonstrate that SMSI can occur on TiO2‐supported Pt single atoms but at a much higher reduction temperature than that for Pt nanoparticles (NPs). Pt single atoms involved in SMSI are not covered by the TiO2 support nor do they sink into its subsurface. The suppression of CO adsorption on Pt single atoms stems from coordination saturation (18‐electron rule) rather than the physical coverage of Pt atoms by the support. Based on the new finding it is revealed that single atoms are the true active sites in the hydrogenation of 3‐nitrostyrene, while Pt NPs barely contribute to the activity since the NP sites are selectively encapsulated. The findings in this work provide a new approach to study the active sites by tuning SMSI. [ABSTRACT FROM AUTHOR]

The factors that cause the instability of dye‐sensitized solar cells (DSSCs) remain to be elucidated. In this work, we focus on the light‐induced instability of N719 sensitizer that represents a large class of the ruthenium bipyridine sensitizers in DSSCs through in situ surface‐enhanced Raman spectroscopy (SERS) investigations. Systematic studies of surface plasmon‐driven reactions coupled with density functional theory (DFT) calculations clearly suggest the decarboxylation reaction induced by "hot electrons" generated on plasmonic metal surface as the reason for the instability. This decarboxylation reaction is also validated on TiO2 surface with the assistance of matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF‐MS). This reaction is possibly the main reason leading to the inefficiency of N719 sensitization in DSSCs. Our findings may broaden the research scope of surface plasmon‐assisted catalytic reactions and provide insight into the optimal design of ruthenium based photosensitizers for DSSCs. The decarboxylation reaction of N719 molecules upon light illumination, which could be the main reason leading to the instability of DSSCs, was demonstrated by the in situ SERS technique. [ABSTRACT FROM AUTHOR]

Artificial photosynthesis requires the practical use of efficient, robust, and economical water-oxidation catalysts (WOCs) for chemical-fuel production. The synthesis of amorphous cobalt oxide nanoparticles (ca. 2 nm) is reported as a WOC with a turnover frequency up to 8.6 s−1 in the photocatalytic Ru(bpy)32+-Na2S2O8 system (bpy=2,2′-bipyridyl). This activity is unprecedented in heterogeneous cobalt-based WOCs and is even comparable to that of a state-of-the-art homogeneous cobalt-based polyoxometalate catalyst. With the help of experimental and computational X-ray absorption spectroscopy, the atomic structure of the synthesized amorphous cobalt oxide nanoparticles was characterized, and it consists of a one-dimensional chain of dimeric edge-sharing CoO6 octahedra. Theoretical calculations suggest that this structure was able to promote O−O bond coupling, unlike crystalline cobalt oxide WOCs, which led to the enhanced water-oxidation activity. [ABSTRACT FROM AUTHOR]

BiVO 4 film coupled with resorcinol–formaldehyde resin (RFS) nanoparticles to form BiVO 4 /RFS heterojunction film as photoanode for solar water oxidation. The conduction and valence band potential of RFS nanoparticles were lower than those of BiVO 4 , and the surface holes and electrons could be directionally transferred to RFS nanoparticles and BiVO4 film, respectively. [Display omitted] • BiVO 4 /RFS film photoanodes were prepared by coupling BiVO 4 films with resorcinol–formaldehyde resin nanoparticles for solar water oxidation. • The light harvesting and electrochemical properties of the optimal BiVO 4 /RFS film was close to the BiVO 4 film. • Better water oxidation activity, kinetics and stability were observed on the BiVO 4 /RFS film photoanode. • The conduction and valence band potential of RFS nanoparticles were lower than those of BiVO 4 , and their surface holes and electrons could be directionally transferred to RFS nanoparticles and BiVO 4 film, respectively. The poor properties of carrier separation and transfer on BiVO 4 surface are two major bottlenecks for nanostructured BiVO 4 photoanodes during solar water oxidation. Herein, BiVO 4 /resorcinol–formaldehyde resin (BiVO 4 /RFS) heterojunction films were prepared by coupling resorcinol–formaldehyde resin (RFS) nanoparticles on BiVO 4 films' surface, and investigated as photoanodes for solar water oxidation. The light harvesting and electrochemical properties of the resultant BiVO 4 /RFS film was close to the BiVO 4 film, but its carrier radiative recombination was weakened significantly. Relative to the BiVO 4 film photoanode, better water oxidation activity, kinetics and stability were observed on the BiVO 4 /RFS film photoanode. The conduction and valence band potential of RFS nanoparticles were discovered to be lower than those of BiVO 4 , and the surface photogenerated holes and electrons could be directionally transferred to RFS nanoparticles and BiVO 4 film, respectively. The higher solar water oxidation performance on the BiVO 4 /RFS photoanode was mainly originated from the separation and transfer of surface carrier through the BiVO 4 /RFS coupling interfaces under AM 1.5G irradiation. The present work could provide inspiration in the design and development of similar heterojunction materials for solar water splitting. [ABSTRACT FROM AUTHOR]

Plate-like LiMnPO 4 nanomaterial for Li-ion batteries is synthesised successfully via a facile solvothermal process in mixed water-diethylene glycol (DEG) solvents at 190 °C for 3 h. Experimental variables, including reaction time, reaction temperature and reactant mole ratio, are discussed in detail. A tentative reaction mechanism is proposed on the basis of the time dependent trials. It is found that, with the increase of reaction temperature, the formation of LiMnPO 4 phase is accelerated and the reaction for synthesizing LiMnPO 4 can be finished in a shorter time. Studies on the effect of reactant mole ratio further support the proposed mechanism. The electrochemical properties of obtained LiMnPO 4 are examined after a carbon coating process. Electrochemical tests show that the obtained LiMnPO 4 at 190 °C for 3 h exhibits better electrochemical performances than the LiMnPO 4 synthesized at 170 °C for 4.5 h or 150 °C for 6 h. It is clear that an improved electrochemical performance can be obtained with the increase of reaction temperature and the decrease of reaction time. This result provides us thoughts and guidance to optimize the reaction conditions by harmonizing the reaction temperature and reaction time, which is beneficial for the practical application. [ABSTRACT FROM AUTHOR]

Abstract: Zn0.95Cu0.02Cr0.03O nanoparticles were successfully prepared by sol–gel method under different atmospheres (air and argon). X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, photoluminescence spectroscopy and vibrating sample magnetometer were used to investigate the effect of annealing atmospheres on the structure, optical and magnetic properties of Zn0.95Cu0.02Cr0.03O diluted magnetic semiconductors. The results showed that the Zn0.95Cu0.02Cr0.03O nanoparticles with 16.5nm and 17.2nm sintered in different atmospheres had a hexagonal wurtzite structure without any secondary phases. X-ray photoelectron spectroscopy analysis indicated that the Cr ions were the +3 and the Cu exhibits different valence state in the Zn0.95Cu0.02Cr0.03O samples annealed in different atmosphere. The annealing atmosphere was found to have effect on the optical and magnetic properties of the Zn0.95Cu0.02Cr0.03O samples. [Copyright &y& Elsevier]

• Ag nanoparticles are anchored onto CuS sub-micron flowers to form composites. • The CuS@Ag electrodes exhibit enhanced charge storage property. • The decoration of Ag nanoparticles increases the electrical conductivity. • The generated electric field at the CuS/Ag interface accelerates the charge transfer. [Display omitted] In this reported work, Ag nanoparticles (NPs) decorated CuS sub-micron flowers are synthesized using a facile, solvothermal reaction coupled with a silver mirror reaction. The experimental results and theoretical calculations reveal that decorating the CuS with Ag NPs increases its intrinsic electrical conductivity and generates an electric field at the interface between Ag and CuS. These effects promote the efficient utilization of active materials and accelerate the interface charge transfer and electrochemical reaction kinetics. Consequently, the maximum specific capacity of the prepared CuS@Ag electrodes is found to be as high as 702 C g−1 at 2 A g−1, which is about 5 times greater than the pure CuS electrode. In addition, the capacity value is 400 C g−1 at 20 A g−1 and it exhibits 93% retention of the initial capacity after 5000 cycles at 10 A g−1. Moreover, a hybrid supercapacitor (HSC) device is assembled employing the CuS@Ag electrode as the positive electrode, which delivers an energy density of 51.1 Wh kg−1 at a power density of 798 W kg−1. These results demonstrate the promising potential of the fabricated CuS@Ag composites for further application in HSCs. [ABSTRACT FROM AUTHOR]

Abstract: Zn0.97Cu0.01V0.02O nanoparticles have been successfully prepared by the sol–gel method and sintered at 600°C in argon and air atmosphere, respectively. The effects of annealing atmosphere on the structural, optical and magnetic properties of the obtained samples were studied. The X-ray diffraction result showed that the Zn0.97Cu0.01V0.02O was single phase with the wurtzite structure of ZnO. The sample annealed in air had much better crystallization. Photoluminescence shows an increase in green emission when annealing in argon. The two Zn0.97Cu0.01V0.02O samples exhibited ferromagnetism at room temperature. The ferromagnetism in this study was itself property of Cu, V co-doped ZnO and not originated from the secondary phase. [Copyright &y& Elsevier]

Abstract: Carbon nanoparticles (CNPs) (6–18nm in size) were prepared by refluxing corn stalk soot in nitric acid. The obtained acid-oxidized CNPs are soluble in water due to the existence of carboxylic and hydroxyl groups. 13C NMR measurement shows the CNPs are mainly of sp2 and sp3 carbon structure different from CNPs obtained from candle soot and natural gas soot. Furthermore, these CNPs exhibit unique photoluminescence properties. Interestingly, the CNPs might be exploited to immobilize on the surface of porous silica particles as chromatographic stationary phase. The resultant packing material was evaluated by high-performance liquid chromatography, indicating that the new stationary phase could be used in hydrophilic interaction liquid chromatography (HILIC) and per aqueous liquid chromatography (PALC) modes. The separation of five nucleosides, four sulfa compounds and safflower injection was achieved by using the new column in the HILIC and PALC modes, respectively. [Copyright &y& Elsevier]

Abstract: Yttrium-doped ZnO nanoparticles (Zn1−x Y x O, x =0, 0.03, 0.05) were synthesized by sol–gel technique. The effects of yttrium doping concentration on the structures, morphologies and optical properties of as-synthesized Zn1−x Y x O nanoparticles were investigated in detail. The results from structural characterizations clearly demonstrated that yttrium ions were successfully doped into the crystal lattice of ZnO matrix. Besides a UV emission centered at ∼383nm, the PL spectra of all the samples exhibited a broad deep-level emission, which can be deconvoluted into two Gauss peaks centered at 539nm (P1) and 598nm (P2), respectively. As the concentration of Y doping increased from 0% to 5%, the peak position with maximum intensity in deep-level emission band was gradually tuned from 539nm to 598nm and the relative intensity ratio of I P1/I P2 also decreased step by step, which revealed a unique optical property of yttrium-doped ZnO nanoparticles. [Copyright &y& Elsevier]

Abstract: ZnS:Mn2+ nanocrystals (NCs) were synthesized by a simple solvothermal method at 180°C in different solvents. The NCs prepared in ethanol yielded cubic nanoparticles (NPs) with diameters of 10–15nm. The NCs prepared in ethylenediamine and water (1:1 in volume ratio) yielded hexagonal nanorods (NRs) with diameters of 8–10nm. X-ray absorption fine structure (XAFS) measurements were carried out to probe the local environment surrounding the Mn ions in the NPs and the NRs. The results showed that Mn ions were incorporated into the ZnS lattice substituting the Zn sites. The yellow–orange emission from the Mn2+ 4T1–6A1 transition was observed, its intensity relative to the blue–green emission increased from NPs to NRs. The surface effect was the main factor affecting the thermal and optical stability of NCs. The fluorescence lifetime of the Mn2+ emission for the NPs and NRs was 0.662 and 0.224ms, respectively. [Copyright &y& Elsevier]

Abstract: The undoped ZnO nanoparticles and the Cr-doped ZnO nanoparticles were successfully synthesized by the sol–gel method. The structure, the optical characteristics and the magnetic properties of the produced samples were studied. The results indicated that Cr ions substituted for Zn ions successfully and the Cr-doping restrained the growth of the crystal lattice. The Cr ions exhibited +3 valence state other than +2 valence state. The dopant concentration was about 3atm% in the Cr-doped ZnO nanoparticles, which was consistent with the design of our experiment. Compared with the photoluminescence (PL) spectrum of the ZnO nanoparticles, the peak position of ultraviolet (UV) emission of the Cr-doped ZnO nanoparticles exhibited blue shift, and the deep level emission band was sharply suppressed. Moreover, the Cr-doped ZnO nanoparticles had good ferromagnetic property at room temperature. [Copyright &y& Elsevier]

Abstract: Mg-doped Ni nanoparticles with the hexagonal close-packed (hcp) and face-centered cubic (fcc) structure have been synthesized by sol–gel method sintered at different temperatures in argon atmosphere. The sintering temperature played an important role in the control of the crystalline phase and the particle size. The pure hcp Mg-doped Ni nanoparticles with average particle size of 6.0nm were obtained at 320°C. The results indicated that the transition from the hcp to the fcc phase occurred in the temperature range between 320°C and 450°C. Moreover, the VSM results showed that the hcp Mg-doped Ni nanoparticles had unique ferromagnetic and superparamagnetic behavior. The unsaturation even at 5000Oe is one of the superparamagnetic characteristics due to the small particle size. From the ZFC and FC curves, the blocking temperature T B of the hcp sample (6.0nm) was estimated to be 10K. The blocking temperature was related to the size of the magnetic particles and the magnetocrystalline anisotropy constant. By theoretical calculation, the deduced particle size was 6.59nm for hcp Mg-doped Ni nanoparticles which was in agreement with the results of XRD and TEM. [Copyright &y& Elsevier]

In the present study, the manganese ferrite (MnFe 2 O 4) nanoparticles were controllably anchored on the surface of MgAl-layered double hydroxide (MgAl-LDH) using a facile two-step hydrothermal method, and the as-prepared MnFe 2 O 4 /MgAl-LDH nanocomposites were adopted as the magnetic dispersed phase to prepare a stable and uniform magnetorheological (MR) suspension. The obtained MnFe 2 O 4 /MgAl-LDH nanocomposites were deeply characterized by XRD, TEM, XPS, BET and SQUID, and the viscoelastic properties of MnFe 2 O 4 /MgAl-LDH based MR fluid were investigated in detail under the action of different magnetic fields. More importantly, the results of sedimentation tests showed that the sedimentation stability of MnFe 2 O 4 /MgAl-LDH based MR fluid was much higher than that of carbonyl iron (CI) particles based MR fluid. The improved sedimentation stability can be attributed to the special plate-like structure, high specific surface area and reduced density difference. • MnFe 2 O 4 /MgAl-LDH nanocomposites were prepared using a facile two-step hydrothermal method. • Mesoporous structures, high specific surface area and superparamagnetic behavior. • A stable MR fluid based on MnFe 2 O 4 /MgAl-LDH was prepared. • Improved viscoelastic properties and sedimentation stability were achieved. [ABSTRACT FROM AUTHOR]

Telomerase and microRNA (miRNA) are biomarkers closely related to tumors. Simultaneous detection of both markers can improve accuracy and reliability of early diagnosis. Based on the mechanism of fluorescence resonance energy transfer (FRET), two fluorescent DNA probes were designed for telomerase and miRNA-21. The probes were wrapped by gelatin through electrostatic interaction to form nanoparticles. After that, we synthesized molecularly imprinted coating of transferrin on the surface of gelatin nanoparticles, which can avoid the immune stress response and macrophage phagocytosis to help gelatin nanoparticles enter into the cells smoothly through endocytosis. Following with the degradation of gelatin in the cells, DNA probes were released to react with telomerase and miRNA-21 and lead to the change of the fluorescence signal. Thereby the simultaneous imaging of telomerase and miRNA-21 were successfully achieved in HeLa cells and HepG2 cells. The proposed strategy shows the simultaneous imaging for different biological markers with DNA probes by preventing them from being hydrolyzed with nucleases before the determination and achieves reliable method for early diagnosis of cancer. Image 1 • Simultaneous imaging of telomerase and microRNA-21 in living cells were performed. • Two probes were designed based on fluorescence resonance energy transfer. • Gelatin nanoparticles (GNPs) are biodegradable in lysosome to release the probes. • The molecularly imprinted coating of transferrin on GNPs can avoid immune stress response and macrophage phagocytosis. [ABSTRACT FROM AUTHOR]

This work was primarily focused on the synthesis, characterization and biomedical applications of cobalt ferrite (CoFe 2 O 4) nanoparticles, which were synthesized by a facile solvothermal method using an amino acid of Leucine (Leu) as the surface coating agents. The morphology, structure and properties of the as-synthesized uncoated and Leu-coated CoFe 2 O 4 nanoparticles were characterized in detail by means of XRD, SEM, TEM, DLS, FTIR, XPS, TGA and SQUID. More importantly, it was found that the Leu-coated CoFe 2 O 4 nanoparticles can be used as the efficient drug delivery with a drug loading capacity of 0.32 mg/mg for doxorubicin hydrochloride (DOX), and the loaded DOX demonstrated a sustained and progressive release manner. The in vitro cytotoxicity studies towards the HeLa cells were carried out, and the results indicated that the Leu-coated CoFe 2 O 4 nanoparticles exhibited a relatively high cell viability compared with that of bare CoFe 2 O 4 nanoparticles and the DOX loaded Leu-coated CoFe 2 O 4 nanoparticles presented an obvious cytotoxic effect on HeLa cells. • Leucine coated CoFe 2 O 4 nanoparticles obtained by a facile solvothermal method. • Superparamagnetic behavior with saturation magnetization of 40.1 emu/g. • Negligible cytotoxicity after 24 h treatment even at a high particle concentration. • High drug loading capacity and a sustained and progressive release manner. [ABSTRACT FROM AUTHOR]

DNA-loaded molecularly imprinted gelatin nanoparticles (GDMI-NPs) were prepared to deliver the Cy3- and Cy5-labelled DNA probe to a tumor region. This allows the activity of telomerase can be detected over 3–400 cells with a low detection limit (3 cells). Fluorescence images were acquired at an excitation wavelength of 535 nm and the emission from the green channel (550–580 nm; label Cy3) and the red channel (650–680 nm; label Cy5). HeLa cells and HepG2 cells were both used to test the performance of GDMI-NPs. Experimental results confirmed the GDMI-NPs has hardly retained in liver and spleen tissue, and its circulated time was longer than that of non-imprinted nanoparticles in blood. The ability of GDMI-NPs to resist immuno stress and anti-macrophage phagocytosis shows great potential for cancer diagnosis and as a drug carrier. [ABSTRACT FROM AUTHOR]