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Colmont M.,CNRS Laboratory of Catalysis and Solid State Chemistry | Endara D.,CNRS Laboratory of Catalysis and Solid State Chemistry | Aliev A.,CNRS Laboratory of Catalysis and Solid State Chemistry | Terryn C.,Plateforme Imagerie Cellulaire et Tissulaire | And 2 more authors.
Journal of Solid State Chemistry

Single crystals of two novel bismuth copper oxyphosphates were grown from a unique melt. They have been structurally characterized by means of single crystal X-Ray Diffraction (XRD). Bi29.4Cu9.29O 32(PO4)16Cu2.63 (1) is orthorhombic, space group Pca21, a=33.0549(2)Ǻ, b=11.6991(4) Ǻ and c= 5.2902(2)Ǻ, R1= 0.059 and wR 2=0.061. Bi37.2Cu18.8O44(PO 4)24Cu5 (2) is orthorhombic, space group Pna21, a=11.6010(3)Ǻ, b=47.4384(5) Ǻ and c= 5.267(2)Ǻ, R1=0.0940 and wR2=0.0981. Both compounds are formed of similar 1D building units (BUs) organized into two different 3D regular intergrowths mediated by phosphate groups. Here, the so-called 1D-BUs are infinite ribbons formed by edge-sharing O(BiM)4 tetrahedra with n=4 and n=3 tetrahedra-wide units. Both compounds were analyzed from the viewpoint of their relationship with the parent δ-Bi 2O3 fluoritelike structure, where phosphorus atoms substitutes for some Bi sites. A non-exhaustive review of the related structural types is given. We have checked by second harmonic generacy (SHG) microscopy that the two noncentrosymmetric structures (despite polar subunits) lead to SHG before the samples are irreversibly damaged. © 2013 Elsevier Inc. All rights reserved. Source

Lu M.,University of Lille Nord de France | Lu M.,CAS Changchun Institute of Applied Chemistry | Colmont M.,University of Lille Nord de France | Huve M.,University of Lille Nord de France | And 4 more authors.
Inorganic Chemistry

Two new alkali bismuth oxosulfates, [Bi12O15]Li2(SO4)4 (I) and [Bi7K2O8]K(SO4)4 (II), have been synthesized by heating a mixture of Bi2O3, CuSO45H2O, and A2CO3 (A = Li, K), and characterized by single crystal XRD, transmission electron microscopy, and multiphoton SHG and IR spectroscopy. In the above formula the [BixOy] subunits denote the 3D-porous (I) or 1D-columnar (II) polycationic host-lattice formed of edge-sharing OBi4 or O(Bi,K)4 oxocenterd tetrahedra. The SO4 2- groups and alkali ions are arranged into channels in the interstices leading to original opened crystal structures for these two first reported alkali oxo-bismuth sulfates. The strong adaptability of the oxocentered framework is demonstrated by the possibility of preparing single crystals of [Bi8.73K0.27O8]K1.54(PO4)4 (III) whose crystal structure is similar to those of II with disorder between OBi4 and O(Bi3,K) tetrahedra and different channel occupancy due to the aliovalent replacement of SO4 2- for PO4 3-. © 2014 American Chemical Society. Source

Kovrugin V.M.,University of Lille Nord de France | Kovrugin V.M.,Saint Petersburg State University | Colmont M.,University of Lille Nord de France | Terryn C.,Plateforme Imagerie Cellulaire et Tissulaire | And 4 more authors.
Inorganic Chemistry

The PbO-NiO-SeO2 ternary system was fully studied using constant hydrothermal conditions at 473 K. It yields the establishment of the corresponding phase diagram using a systematic assignment of reaction products by both powder and single-crystal X-ray diffraction. It leads to the preparation of three novel lead nickel selenites, α-PbNi(SeO3)2 (I), β-PbNi(SeO3)2 (II), and PbNi2(SeO2OH)2(SeO3)2 (III), and one novel lead cobalt selenite, α-PbCo(SeO3)2 (IV), which have been structurally characterized. The crystal structures of the α-forms I, IV, and III are based on a 3D complex nickel selenite frameworks, whereas the β-PbNi(SeO3)2 modification (II) consists of nickel selenite sheets stacked in a noncentrosymmetric structure, second-harmonic generation active. The pH value of the starting solution was shown to play an essential role in the reactive processes. Magnetic measurements of I, III, and IV are discussed. © 2015 American Chemical Society. Source

Millerot-Serrurot E.,French National Center for Scientific Research | Guilbert M.,French National Center for Scientific Research | Fourre N.,French National Center for Scientific Research | Witkowski W.,French National Center for Scientific Research | And 6 more authors.
Cancer Cell International

Background: The cell microenvironment, especially extracellular matrix proteins, plays an important role in tumor cell response to chemotherapeutic drugs. The present study was designed to investigate whether this microenvironment can influence the antimigratory effect of an anthracycline drug, doxorubicin, when tumor cells are grown in a matrix of type I collagen, a three-dimensional (3D) context which simulates a natural microenvironment.Methods: To this purpose, we studied the migratory parameters, the integrin expression, and the activation state of focal adhesion kinase (FAK) and GTPase RhoA involved in the formation of focal adhesions and cell movement. These parameters were evaluated at non toxic concentrations which did not affect HT1080 cell proliferation.Results: We show that while doxorubicin decreased cell migration properties by 70% in conventional two-dimensional (2D) culture, this effect was completely abolished in a 3D one. Regarding the impact of doxorubicin on the focal adhesion complexes, unlike in 2D systems, the data indicated that the drug neither affected β1 integrin expression nor the state of phosphorylation of FAK and RhoA.Conclusion: This study suggests the lack of antiinvasive effect of doxorubicin in a 3D environment which is generally considered to better mimic the phenotypic behaviour of cells in vivo. Consistent with the previously shown resistance to the cytotoxic effect in a 3D context, our results highlight the importance of the matrix configuration on the tumor cell response to antiinvasive drugs. © 2010 Millerot-Serrurot et al; licensee BioMed Central Ltd. Source

Aliev A.,University of Lille Nord de France | Kovrugin V.M.,University of Lille Nord de France | Kovrugin V.M.,Saint Petersburg State University | Colmont M.,University of Lille Nord de France | And 5 more authors.
Crystal Growth and Design

The reactions between PbO, Bi2O3 (or BiOCl), and SeO2 by the chemical vapor transport method using HCl as a transporting agent afforded three novel bismuth/lead chloroselenites, namely, β-BiSeO3Cl (1), Bi6(SeO3) 4Cl10 (2), and PbBi10(SeO3) 12Cl8 (3). Compound 1 is noncentrosymmetric (space group Cc, SHG active) and has a giant unit cell (V = 19792(2) Å3). In the context of the complex BiSeO3Cl phase diagram reported by Oppermann et al., it was assigned to the undescribed β-form on the basis of its IR spectra and powder X-ray diffraction pattern. The comparison between the α-, β-, and γ-forms suggests their formation via the condensation of volatile Bi(SeO3)Cl molecules. Analysis of the structures of the α-, β-, and γ-forms indicates that the α → β → γ phase transitions are associated with a dramatic fluctuation of structural complexity together with the transitional character of the β phase. Compounds 1 and 3 are layered compounds with identical ([M8Cl16]8+ and [M 14(SeO3)24]6-) layers, where M stands for Bi in 1 and Pb/Bi in 3. There are additional [Bi12Cl 32]4+ layered subunits in 1. The crystal structure of 2 consists of the [Bi6(SeO3)4Cl10] building blocks forming an open framework with six-membered-ring channels. These three compounds complete the poorly known bismuth selenium oxochloride panorama. © 2014 American Chemical Society. Source

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