Dominique Thiaudière

Bio: Dominique Thiaudière is an academic researcher from Soleil Synchrotron. The author has contributed to research in topics: Thin film & Beamline. The author has an hindex of 28, co-authored 120 publications receiving 2185 citations. Previous affiliations of Dominique Thiaudière include Centre national de la recherche scientifique & European Synchrotron Radiation Facility.

Food-grade TiO 2 impairs intestinal and systemic immune homeostasis, initiates preneoplastic lesions and promotes aberrant crypt development in the rat colon.

Abstract: Food-grade titanium dioxide (TiO2) containing a nanoscale particle fraction (TiO2-NPs) is approved as a white pigment (E171 in Europe) in common foodstuffs, including confectionary. There are growing concerns that daily oral TiO2-NP intake is associated with an increased risk of chronic intestinal inflammation and carcinogenesis. In rats orally exposed for one week to E171 at human relevant levels, titanium was detected in the immune cells of Peyer’s patches (PP) as observed with the TiO2-NP model NM-105. Dendritic cell frequency increased in PP regardless of the TiO2 treatment, while regulatory T cells involved in dampening inflammatory responses decreased with E171 only, an effect still observed after 100 days of treatment. In all TiO2-treated rats, stimulation of immune cells isolated from PP showed a decrease in Thelper (Th)-1 IFN-γ secretion, while splenic Th1/Th17 inflammatory responses sharply increased. E171 or NM-105 for one week did not initiate intestinal inflammation, while a 100-day E171 treatment promoted colon microinflammation and initiated preneoplastic lesions while also fostering the growth of aberrant crypt foci in a chemically induced carcinogenesis model. These data should be considered for risk assessments of the susceptibility to Th17-driven autoimmune diseases and to colorectal cancer in humans exposed to TiO2 from dietary sources.

Modulated phases in NaNbO3: Raman scattering, synchrotron x-ray diffraction, and dielectric investigations

Abstract: Raman spectra of sodium niobate (NaNbO3) were obtained in all phases and revealed a significant disorder in the high-temperature U, T2 and T1 phases and ac omplicated folding of the Brillouin zone at the transitions into modulated S, R, P and N phases associated with the competitive zone-boundary soft mode s( in-phase and out-of phase octahedral tilts) along the M–T–R line. An extensive Raman study combined with x-ray diffraction (XRD) and dielectric measurements confirmed the presence of the incommensurate (INC) phase in sodium niobate. XRD experiments revealed the invar effect in the temperature interval 410–460 K corresponding to the INC phase associated with rotations of the NbO6 octahedra modulated along the b-direction. Our experiments suggest that the phase P consists of three phases: monoclinic (Pm) between 250 and 410 K, INC between 410 and 460 K, and orthorhombic (Po) between 460 and 633 K. At the low-temperature transition to the ferroelectric rhombohedral N phase all folded modes originating from the M- and T-points of the Brillouin zone abruptly disappear, Raman spectra in the N phase become much simpler and all peaks were assigned.

Diffraction techniques and vibrational spectroscopy opportunities to characterise bones.

Abstract: From a histological point of view, bones that allow body mobility and protection of internal organs consist not only of different organic and inorganic tissues but include vascular and nervous elements as well. Moreover, due to its ability to host different ions and cations, its mineral part represents an important reservoir, playing a key role in the metabolic activity of the organism. From a structural point of view, bones can be considered as a composite material displaying a hierarchical structure at different scales. At the nanometre scale, an organic part, i.e. collagen fibrils and an inorganic part, i.e. calcium phosphate nanocrystals are intimately mixed to assure particular mechanical properties.

Local structure in liquid binary Al-Cu and Al-Ni alloys

Abstract: The local short-to-intermediate range structure was studied in liquid Al-Ni and Al-Cu alloys by X-ray diffraction as a function of temperature and composition. A containerless technique, combining aerodynamic levitation and inductive heating, was used to position and melt the samples. The scattered intensity was recorded by an image plate. Liquid samples with compositions corresponding to an intermetallic solid phase show a pronounced prepeak in the structure function S(Q).

Ion specific effects on the structure of molten AF-ZrF4 systems (A+ = Li+, Na+, and K+).

Abstract: The structure of AF-ZrF(4) system (A(+) = Li(+), Na(+), K(+)) compounds in the liquid state is studied using an approach combining EXAFS spectroscopy with molecular dynamics simulations. A very good agreement is observed between the two techniques, which allows us to propose a quantitative description of the liquids. From the Zr(4+) solvation shell point of view, we observe a progressive stabilization of the 7-fold and then of the 6-fold coordinated complexes when passing from Li(+) to Na(+) and K(+) as a "counterion". Particular attention is given to the systems consisting of 35 mol % of ZrF(4). At that particular composition, the ZrF(6)(2-) complex predominates largely whatever the nature of the alkali. The calculated vibrational properties of this complex are in excellent agreement with a previous Raman spectroscopy experiment on molten KF-ZrF(4). The most important differences are observed for the lifetime of these octahedral units, which increases importantly with the size of the monovalent cation. On a larger scale, an intense first sharp diffraction peak is observed for the Zr(4+)-Zr(4+) partial structure factor, which can be attributed to the correlations between the octahedral units formed.

X-Ray Diffraction

Abstract: Interpretation of X-ray Powder Diffraction Patterns . By H. Lipson and H. Steeple. Pp. viii + 335 + 3 plates. (Mac-millan: London; St Martins Press: New York, May 1970.) £4.

The side effects of platinum-based chemotherapy drugs: a review for chemists

Abstract: The platinum-based drugs cisplatin, carboplatin and oxaliplatin are regularly prescribed in the treatment of cancer and while they are effective, their use is limited by their severe, dose-limiting side effects (also referred to as adverse effects/events). In total, a cancer patient can experience any combination of around 40 specific side effects. The dose-limiting side effect for cisplatin is nephrotoxicity, for carboplatin it is myelosuppression, and for oxaliplatin it is neurotoxicity. Other common side effects include anaphylaxis, cytopenias (including leukopenia and neutropenia, thrombocytopenia, and anaemia), hepatotoxicity, ototoxicity, cardiotoxicity, nausea and vomiting, diarrhea, mucositis, stomatitis, pain, alopecia, anorexia, cachexia, and asthenia. The side effects may require patients to be prescribed dose reductions in their platinum drugs of between 25 and 100%. Furthermore, patients require extensive monitoring of their biochemistries, kidney and liver function, and depending on the drug, hearing tests. Finally, patients are commonly co-prescribed additional non-chemotherapy based drugs to treat the side effects which can include antiemetics, antibiotics and myeloid growth factors, mannitol, propafenone, saline hyperhydration, magnesium supplements, monoclonal antibody cytokine blockers, and antioxidants.