Nebulized Gadolinium‐Based Nanoparticles: A Theranostic Approach for Lung Tumor Imaging and Radiosensitization

Lung cancer is the most common and most fatal cancer worldwide. Thus, improving early diagnosis and therapy is necessary. Previously, gadolinium‐based ultra‐small rigid platforms (USRPs) were developed to serve as multimodal imaging probes and as radiosensitizing agents. In addition, it was demonstrated that USRPs can be detected in the lungs using ultrashort echo‐time magnetic resonance imaging (UTE‐MRI) and fluorescence imaging after intrapulmonary administration in healthy animals. The goal of the present study is to evaluate their theranostic properties in mice with bioluminescent orthotopic lung cancer, after intrapulmonary nebulization or conventional intravenous administration. It is found that lung tumors can be detected non‐invasively using fluorescence tomography or UTE‐MRI after nebulization of USRPs, and this is confirmed by histological analysis of the lung sections. The deposition of USRPs around the tumor nodules is sufficient to generate a radiosensitizing effect when the mice are subjected to a single dose of 10 Gy conventional radiation one day after inhalation (mean survival time of 112 days versus 77 days for irradiated mice without USRPs treatment). No apparent systemic toxicity or induction of inflammation is observed. These results demonstrate the theranostic properties of USRPs for the multimodal detection of lung tumors and improved radiotherapy after nebulization.     

A first quantitative XPS study of the surface films formed, by exposure to water, on Mg and on the Mg-Al intermetallics: Al3Mg2 and Mg17Al12

An XPS investigation was carried out of the surface films, formed by exposure to ultrapure water, on mechanically ground Mg and the two Mg-Al intermetallic compounds: Al₃Mg₂ and Mg₁₇Al₁₂. The mechanically ground Mg surface had a film of MgO at the Mg metal surface covered by a Mg(OH)₂ layer, formed by the reaction of the MgO with water vapour in the air. Upon immersion in ultrapure water, this film converted to a duplex film with an inner MgO layer next to the Mg metal and an external porous hydroxide layer. For both intermetallics, the XPS data is consistent with (i) preferential dissolution of Mg and (ii) a 10 nm thick film on the surface after immersion in ultrapure water; the film composition on Al₃Mg₂ was AlMg_1.4O_0.2(OH)_5.4 whilst on Mg₁₇Al₁₂ the composition was AlMg_2.5(OH)₈.     

Sensory profiles and preference analysis in ornamental horticulture: The case of the rosebush

The context of ornamental horticulture is considered in order to extend the techniques of sensory and preference evaluation by taking the rosebush as a plant model. In a preliminary study (Boumaza, Demotes-Mainard, Huché-Thélier, & Guérin, 2009), a sensory evaluation was conducted in order to set up a list of attributes. Subsequently, this list was adapted to assess 10 rosebushes. After the control of the panel performance using a multivariate strategy of analysis, the average scores were used in product mapping. The evaluation of the preferences with regard to these rosebushes was undertaken: 253 subjects were asked to rank the products by decreasing order of liking. Thereafter, the preference data were subjected to an internal preference mapping and a cluster analysis. Six homogeneous segments of consumers were eventually retained. By way of performing an external preference mapping, the average ranks were regressed upon the sensory attributes using principal component regression: the preferences of 67% of the consumers were satisfactorily explained by the attributes.     

Chemical stimulation techniques for geothermal wells: experiments on the three-well EGS system at Soultz-sous-Forêts,France

Rock matrix stimulation is a method of enhancing well production or injection within a broad range of challenging environments, varying from naturally fractured limestones to sandstones with complex mineralogy. A common and often successful stimulation option, matrix acidizing, utilizes acids that react and remove mineral phases restricting fluid flow. Reviewed is the technology of chemical treatments available for oil, gas and geothermal wells and the key elements and results of the chemical reservoir stimulation program at the Soultz-sous-Forêts, France, Enhanced Geothermal System Project.     

Kinetics, acid sites and deactivation of H-mordenite during the SCR of NOx with CH4

H-mordenites are active for the SCR reaction but they suffer irreversible partial deactivation after being on stream for one hour at 650°C. The reaction orders and activation energies are not significantly affected by deactivation. This indicates that deactivation originates in a decrease in the number of active sites due to dealumination and possible pore blockage. The NO disappearance rate correlates with TPD NH₃ between 300 and 700°C; FTIR confirms these results. ¹²⁹Xe NMR of adsorbed xenon shows that pore blockage occurs and is due to the presence of aluminum species in the main zeolite channels. The overall deactivation process and the role of acid sites is discussed in terms of the current literature. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermoreversible gelation of poly[hexyl isocyanate]: Effect of solvent type

The thermoreversible gelation of poly[hexyl isocyanate] (PHIC), a rather stiff polymer, has been studied in two closely-related solvents of the alcane series, namely heptane and octane. Temperature-concentrations phase diagrams have been established for both systems. The occurrence of polymer-solvent compound is suggested in heptane but not in octane. This conclusion receives further support from neutron diffraction investigations through the use of the isotopic labelling technique. Finally, it is observed that the morphology is also affected by the solvent type although still displaying a fibrillar network structure.     

Tensile basic creep versus compressive basic creep at early ages: comparison between normal strength concrete and a very high strength fibre reinforced concrete

The paper presents experimental results concerning the comparison of tensile and compressive basic creep behaviours at early ages of two different concretes: a normal strength concrete (NSC) and a very high strength fibre reinforced concrete (HPFRC). This research project has been done in the context of a bilateral collaboration between Polytechnique Montreal and IFSTTAR. Observations on the HPFRC showed specific compressive creep similar to the specific tensile creep. Moreover, the specific creep curves obtained under compressive and tensile loading had always positive values, i.e. they were in same direction of the applied load on specimens. Measurements made on the NSC revealed specific compressive creep with positive values (in the loading direction). However, specific tensile creep presented negative values (opposite direction of loading) for a long period. A physical explanation based on the existence of two mechanisms with opposite effect is proposed to describe these basic creep results. The first mechanism is a coupling between the microcracking process and the water transfers that lead to additional self-drying shrinkage; the second mechanism is the self-healing of concrete induced by the microcracking.     

Ageing of V2O5 thin films induced by Li intercalation multi-cycling

Cyclic voltammetry, XPS, RBS and AFM have been combined to study the ageing mechanism of Li intercalation in V₂O₅ thin films prepared by thermal oxidation of vanadium metal. Multi-cycling tests were performed in 1 M LiClO₄-PC in the potential range E ∈ [3.8, 2.8 V] versus Li/Li⁺, corresponding to the α-to-δ phase transition. XPS and AFM were performed using direct anaerobic and anhydrous transfer. Capacity fading remains inferior to 20% during ∼2500 cycles. XPS shows slight modifications of the oxide composition with a V⁴⁺ concentration increasing from ∼5% prior to cycling to ∼16–27% after cycling, due to Li trapped in the oxide film and to the loss of V₂O₅ active material. The presence of lithium carbonate and lithium-alkyl carbonate species evidences the formation of the so-called SEI layer. AFM evidences the loss of crystalline material by grain exfoliation from the outer V₂O₅ layer of the oxide film. By further exfoliation, the inner VO₂ layer of the oxide film is reached and pits are formed, occupying ∼9–13% of the surface. This de-cohesion at grain boundaries is attributed to the strain generated by repeated lattice distortions. After 3300 cycles, the disappearance of lithium carbonates, whereas Li-alkyl carbonates and/or Li-alkoxides remain on the surface, indicates the dissolution and/or conversion of the SEI layer. After 4500 cycles, the oxide film became very labile and could be stripped away by rinsing to reveal the vanadium metal substrate.