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Glucose oxidase (GOx)-based nanotheranostic agents hold great promise in tumor starvation and its synergistic therapy. Self-assembled plasmonic gold vesicles (GVs) with unique optical properties, large hollow cavity, and strong localized surface plasmon resonance, can be used as multi-functional nanocarriers for synergistic therapy. Herein, GOx-loaded GVs (GV-GOx) were developed for light-triggered GOx release as well as enhanced catalytic activity of GOx, achieving programmable photothermal/starvation therapy. Under near-infrared laser irradiation, the GV-GOx generated strong localized hyperthermia due to plasmon coupling effect of GVs, promoting the release of encapsulated GOx and increasing its catalytic activity, resulting in enhanced tumor starvation effect. In addition, the high photothermal effect improved the cellular uptake of GV-GOx and allowed an efficient monitoring of synergistic tumor treatment via photoacoustic/photothermal duplex imaging in vivo . Impressively, the synergistic photothermal/starvation therapy demonstrated complete tumor eradication in 4T1 tumor-bearing mice, verifying superior synergistic anti-tumor therapeutic effects than monotherapy with no apparent systemic side effects. Our work demonstrated the development of a light-triggered nanoplatform for cancer synergistic therapy.

International audience; The composition and structure properties of the CrOxNy films deposited by RF reactive magnetron sputtering were investigated and correlated with their optical properties. Two kinds of targets Cr2O3 and CrN compounds with variation of N2 and O2 gas flow were used to prepare two series of samples. The phase structure, chemical composition and optical properties of CrOxNy films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and ultraviolet-visible-near-infrared spectrophotometer, respectively. The films mainly consist of Cr2N and CrO3 phases. The Cr/ON ratio derived by XPS varies with the variation of nitrogen with Cr2O3 target. But only lower nitrogen content is detected with variation of oxygen using CrN target. TheCrOxNyy films with higher nitrogen content possess high absorbance around at 35% in the visible light range no matter the target.

The detection of fluoride ion (F−) in living subjects is of value for healthcare and environmental fields. Here, a near-infrared (NIR) turn-on photoacoustic (PA) probe composed of naphthalimide unit, namely LET-1, was developed for chemoselective photoacoustic detection (PAD) of F−. The response and mechanism of the interaction between F− and LET-1 were evaluated through kinetic optical studies, 1HNMR spectra analysis and docking calculations. The results demonstrated that LET-1 could rapidly recognize F− with good selectivity and high sensitivity. Upon the interaction with F−, this non-photoacoustic LET-1 probe could produce a turn-on PA signal at 680 nm, which was used as an indicator for PAD of F− in living subjects, such as soybean sprout and mouse. The present study provides a new approach for in vivo chemoselective PA detection of anions.

In this study, a novel gradient heating procedure was developed to fabricate the targeted metal-ion-imprinted thermo-responsive material, i.e. ion-imprinted thermo-responsive BC derivative (ITB), from bacterial cellulose using Cu2+ as a template and N-isopropylacrylamide (NIPAM) as a monomer; moreover, the structure and properties of ITB were analysed via various analytical techniques including FTIR spectroscopy, DSC, SEM, and Raman spectroscopy. The lower critical solution temperature (LCST) of ITB was 38.57 °C in the heating procedure, whereas it was 30.81 °C in the cooling procedure. The adsorption capacity of ITB for Cu2+ reached 95.20 mg g−1 at 45 °C (>LCST), the desorption rate was 98.81%, and desorption could be simply achieved by washing the adsorbents with water at 20 °C (

X-ray absorption spectroscopy (XAS) at the Co K edge was applied to investigate the chemical environment of Co atoms inside Co/Mo 2 C periodic multilayers. The results show a mixing between Co and Mo 2 C layers prior to any annealing process whereas following annealing from 300°C pure Co layers are observed. XAS results are in agreement with previous nuclear magnetic resonance spectroscopy results. They indicate that the pure Co content increases upon annealing, while it is absent in the as-deposited samples. The comparison of the results, based on the analysis of the data obtained on the multilayer samples and some reference materials, reveals that the ordering of Co atoms inside the Co layers increases upon annealing.

International audience; The Kossel effect is the diffraction by a periodically structured medium, of the characteristic X-ray radiation emitted by the atoms of the medium. We show that multilayers designed for X-ray optics applications are convenient periodic systems to use in order to produce the Kossel effect, modulating the intensity emitted by the sample in a narrow angular range defined by the Bragg angle. We also show that excitation can be done by using photons (X-rays), electrons or protons (or charged particles), under near normal or grazing incident geometries, which makes the method relatively easy to implement. The main constraint comes from the angular resolution necessary for the detection of the emitted radiation. This leads to small solid angles of detection and long acquisition times to collect data with sufficient statistical significance. Provided this difficulty is overcome, the comparison or fit of the experimental Kossel curves, i.e., the angular distributions of the intensity of an emitted radiation of one of the element of the periodic stack, with the simulated curves enables getting information on the depth distribution of the elements throughout the multilayer. Thus the same kind of information obtained from the more widespread method of X-ray standing wave induced fluorescence used to characterize stacks of nanometer period, can be obtained using the Kossel effect.

The feasibility of using GeTe based alloys in thermoelectric power generation has received a revived interest and has been extensively investigated through the approach of substitutional doping in recent times. Here, a systematic study of the thermoelectric properties of Sn doped GeTe prepared by DC magnetron co-sputtering using Sn and GeTe targets is presented. The effect of variation in Sn content was studied on the chemical bonds and of as-deposited films. Thermoelectric properties of as-deposited and fast annealed thin films at 280 °C in vacuum were measured. It is found that Sn forms bond with Te and increasing Sn content decreases the band gap of amorphous samples. The power factor was enhanced both at low temperature and high temperature through the reduction of the electrical resistivity and enhanced seebeck effect caused by changes in the carrier effective mass and carrier concentration. A competitively high power factor of 2.789 × 103 μW/K2m is reached at 300 K for the amorphous films and 1.423 × 103 μW/K2m at 718 K for the crystalline film. This provides a good basis for further enhancement of the power factor.

The adhesion strength between thin films has a significant effect on performance of micro-devices. It is introduced that the effects of three pre-treatment methods: acid, pulse reverse current and anodic current, on the adhesion performance of electrodeposited Ni films on Ni substrate. The adhesion strength, surface and fracture morphology of the Ni films were investigated. The dense oxide films on the Ni substrate were removed effectively by using the anodic dissolution current method in the acidic chloride solutions. Meanwhile, the Ni films treated with specific treatment conditions produced different roughness, which was responsible for the improved adhesion strength. The adhesion strength of the Ni films increased up to 629.8 MPa when substrates were treated with anodic current density of 30 mA/cm2 for 10 min, which is nearly two times higher than that of films treated by 5 vol % HCl for 10 min. The results indicate that the anodic current treatment method effectively improves the adhesion strength of Ni films.

The interface layer has great significance on the potential barrier height of the CdTe/GaAs heterointerface. In this study, the electronic properties of the CdTe/GaAs heterostructure prepared by molecular beam epitaxy was investigated in situ by synchrotron radiation photoemission spectroscopy for CdTe thicknesses ranging from 3.5 to 74.6 Å. During CdTe deposition, an As-Te and Ga-Te interface reaction occurred, which caused the out diffusion of Ga. As a result a stable GaTe interface dipole layer (more than 30 Å) was formed, which reduced the potential barrier height by 0.38 eV. The potential barrier height was in proportion to the chemical bonding density and thickness of the Ga-Te interface layer. These results provide a more fundamental understanding of the influencing mechanism of the interface layer on the potential barrier height of the CdTe/GaAs heterointerface.

A series of Pd/γ-Al2O3 catalysts modified by potassium salts were prepared and evaluated in the reductive cyclization of 2-nitro-2′-hydroxy-5′-methylazobenzene without additional base. These solid base-hydrogenation bifunctional catalysts were characterized and the results demonstrated that potassium salts could have an important impact on the properties and catalytic performance of Pd/γ-Al2O3.

International audience; The evolution upon annealing from room temperature to 600 °C of the microstructure of Co/Mo2C/Y and Co/Y/Mo2C multilayer stacks has been studied by transmission electron microscopy combining HAADF-STEM, EDX and HRTEM. Both kinds of samples show significant amount of intermixing even in the as-deposited state. The mixing further increases upon annealing. Most of the mixing occurs between the Co and the Mo elements, the Y layers staying comparatively preserved. After annealing at 600 °C a surprising sharpening of the interfaces is observed. It is ascribed to the formation of Co-Mo compounds. Combining these analyses with the results we have already published, we can explain in a consistent way the evolution of the x-ray reflectivity measurements of the samples upon annealing. Understanding the evolution the optical properties of such stacks designed to work in the soft x-ray range is essential for improving the optical performance of multilayer structures.

The in situ SiC/Al composites were fabricated in Al-Si-C systems with different Si/C mass ratios and holding time by the method of combustion synthesis and hot press consolidation. The influences of Si/C mass ratio and holding time on the phase constitution, microstructure, and hardness of the composites were investigated. The results indicate that the increase of Si/C mass ratio leads to more uniform size distribution of the SiC particles in the Al matrix. Moreover, by improving the Si/C mass ratio from 4 : 1 to 5 : 1, the maximum size of SiC particle was reduced from 4.1 μm to 2.0 μm. Meanwhile, the percentage of submicroparticles was increased from 22% to 63%, and the average hardness value of the composites was increased by 13%. In addition, when the holding time is set to be fifteen minutes, the Al4C3 phase did not exist in the composites because of its total reactions with Si atoms to form SiC particles, and the average hardness value was 73.8 HB.

The poor adhesion between Diamond-like carbon (DLC) coating and substrates has always restricted its application in tooling industry. In this work, DLC coating was produced on the Cr12MoV steel by in-situ duplex plasma nitriding and arc ion plating (AIP) process to improve its adhesion strength. For comparison, DLC coating was also produced only by AIP process. The microstructure and mechanical properties were investigated by field emission scanning electron microscope, X-ray diffraction, Raman spectroscope, X-ray photoelectron spectroscopy and nanoindenter. Rockwell C indentation, scratch test and tribological tests were conducted to evaluate the adhesion and tribological performance of the coatings. The results show that the hardness of the DLC coating is 22.5 Gpa with a sp3 bond concentration 29.9%. The in-situ duplex process improves the adhesion strength of DLC coating with substrates from 6.4 N to 15.2 N, measured by a diamond Rockwell tip with a 100 μm radius tip. The DLC coating by in-situ duplex process exhibits low friction coefficient of 0.08 and low wear rate of 4.32×10−7 mm3/Nm. The in-situ duplex process does not affect the friction coefficient and wear mechanism, while it is expected to improve the wear resistance due to the better load capacity.

Flexible solar cells have drawn wide attention because of their high photoelectric conversion efficiency, convenient preparation, excellent bendability and lower cost advantages. This paper introduces the effect of mesoporous layer on the morphology of CH3NH3PbI3 films. The uniformity and optical transmittance of the different films were also studied in detail. By adjusting the ratio of TiO2 and ZrO2, mesoporous structure of CH3NH3PbI3 perovskite solar cells were prepared by two-step spin coating. The fabricated films were investigated by XRD, SEM and spectrophotometer. The results indicate that perovskite layers have good surface morphology, density and coverage with TiO2 and ZrO2 composition ratio of 1:1. These well-structured thin films lay a good foundation for the preparation of high performance flexible perovskite solar cells.

We present the characterization of Mg-Co-Zr tri-layer stacks by using x-ray fluorescence induced by x-ray standing waves, both in the grazing incidence (GI) and grazing exit (GE) modes. The introduction of a slit in the direction of the detector improves the angular resolution by a factor 2 and significantly the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kalpha and Co Lalpha characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, we show that the interfaces of the Si/[Mg/Co/Zr] x30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] x30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. The explanation of this opposite behaviour of the Co-on-Zr and Zr-on-Co interfacesis given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents anegative value and the two others positive values. Together with the difference of the surface free energies of Zr and Co, this leads us to consider the Mg/Zr/Co system as aMg/Co x Zr y bi-layer stack, with x/y estimated around 3.5., Published in Journal of Synchrotron Radiation 22, 1419 (2015)http://scripts.iucr.org/cgi-bin/paper?S1600577515016239

We study the interface evolution of a series of periodic Co/Mo2C multilayers as a function of the annealing temperature up to 600{\textdegree}C. Different complementary techniques are implemented to get information on the phenomenon taking place at the interfaces of the stack. The periodical structure of Co/Mo2C multilayer is proven by Time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiles which demonstrate the formation of an oxide layer at both air/stack and stack/substrate interfaces. From Nuclear magnetic resonance (NMR) spectra, we observed the intermixing phenomenon of Co and C atoms for the as-deposited sample, and then at annealing temperature above 300{\textdegree}C Co and C atoms separate from their mixed regions. Comparison of NMR results between Co/Mo 2 C and Co/C references confirms this phenomenon. This is in agreement with x-ray emission spectroscopy (XES) measurements. Furthermore the calculation of the Co-C, Co-Mo and Mo-C mixing enthalpy using Miedema's model gives a proof of the demixing of Co and C atoms present within the stacks above 300{\textdegree}C. From the transmission electron microscopy (TEM) analysis, we found the presence of some crystallites within the as-deposited sample as well as the mainly amorphous nature of all layers. This is confirmed using x-ray diffraction (XRD) patterns which also demonstrate the growth of crystallites induced upon annealing., Published in Applied Surface Science 331, 8-16 (2015). http://dx.doi.org/10.1016/j.apsusc.2014.12.055

6 pages, published in Applied Surface Science 315, 499 (2014) http://www.sciencedirect.com/science/article/pii/S0169433214007272# http://dx.doi.org/10.1016/j.apsusc.2014.03.176; International audience; We study the thermal behaviour of a tri-layer multilayer, designed by inserting a third material, yttrium, into the previously studied Co/Mo2C system. The system is designed to work at near-normal incidence at the wavelength of 14.1 nm. The theoretical reflectivity of Co-based multilayer (Co/Mo2C/Y system) is improved up to 54% after the addition of yttrium. Two types of multilayers with different orders of yttrium layer are deposited: Co/Mo2C/Y and Co/Y/Mo2C. The samples are annealed up to 600 °C. The multilayers were characterized using hard x-ray and extreme ultraviolet reflectivity, nuclear magnetic resonance (NMR) spectroscopy and x-ray diffraction (XRD). The results show that the reflectivity of the Co/Mo2C/Y multilayer is 27.5% at near normal incidence around 14.6 nm for as-deposited sample, and then it decreases gradually after annealing up to 600 °C. A significant period compression is observed from 300 °C annealing and above. The Co/Y/Mo2C multilayer shows low reflectivity, less than 2.5%. NMR spectra reveal that the pure Co layers are completely mixed with other elements since there is no signal from ferromagnetic Co in the annealing samples of the Co/Mo2C/Y multilayer and all Co/Y/Mo2C samples. Based on the NMR and XRD results, we fit the EUV data for both multilayers with two different models in one period taking into account the formation of the interfacial compounds.