69 research outputs found
The structures of the crystalline phase and columnar mesophase of rhodium (II) heptanoate and of its binary mixture with copper (II) heptanoate probed by EXAFS
Look Who’s Talking: The Impacts of the Intrahousehold Allocation of Mobile Phones on Agricultural Prices
Hyper-IgG4 disease: report and characterisation of a new disease
BACKGROUND: We highlight a chronic inflammatory disease we call 'hyper-IgG4 disease', which has many synonyms depending on the organ involved, the country of origin and the year of the report. It is characterized histologically by a lymphoplasmacytic inflammation with IgG4-positive cells and exuberant fibrosis, which leaves dense fibrosis on resolution. A typical example is idiopathic retroperitoneal fibrosis, but the initial report in 2001 was of sclerosing pancreatitis. METHODS: We report an index case with fever and severe systemic disease. We have also reviewed the histology of 11 further patients with idiopathic retroperitoneal fibrosis for evidence of IgG4-expressing plasma cells, and examined a wide range of other inflammatory conditions and fibrotic diseases as organ-specific controls. We have reviewed the published literature for disease associations with idiopathic, systemic fibrosing conditions and the synonyms: pseudotumour, myofibroblastic tumour, plasma cell granuloma, systemic fibrosis, xanthofibrogranulomatosis, and multifocal fibrosclerosis. RESULTS: Histology from all 12 patients showed, to varying degrees, fibrosis, intense inflammatory cell infiltration with lymphocytes, plasma cells, scattered neutrophils, and sometimes eosinophilic aggregates, with venulitis and obliterative arteritis. The majority of lymphocytes were T cells that expressed CD8 and CD4, with scattered B-cell-rich small lymphoid follicles. In all cases, there was a significant increase in IgG4-positive plasma cells compared with controls. In two cases, biopsies before and after steroid treatment were available, and only scattered plasma cells were seen after treatment, none of them expressing IgG4. Review of the literature shows that although pathology commonly appears confined to one organ, patients can have systemic symptoms and fever. In the active period, there is an acute phase response with a high serum concentration of IgG, and during this phase, there is a rapid clinical response to glucocorticoid steroid treatment. CONCLUSION: We believe that hyper-IgG4 disease is an important condition to recognise, as the diagnosis can be readily verified and the outcome with treatment is very good
Discotic Liquid Crystals of Transition Metal Complexes, 2: The Effect of Alkyl Chain Length on Discotic Mesomorphism in Bis[1,3-di( p-n
Scattering of a Crystalline Gel Network:Â A New Organogel Based upon a Benzohydroxamic Acid Derivative
Columnar to nematic mesophase transition in mixtures of rhodium or copper soaps with hydrocarbon solvents
This paper describes observations of the mesomorphic behaviour of mixtures of rhodium eicosanoate or copper dodecanoate with solvents such as toluene, decahydronaphthalene, and (+) camphene. The mesophase found with these compounds at high temperatures turns from columnar to nematic when the weight fraction of the solvent (toluene, decahydronaphthalene is increased beyond a value of about 50Â %. The binary phase diagram of the copper compound with toluene was experimentally determined using polarizing optical microscopy, differential scanning calorimetry and X-ray diffraction. The novel feature of the nematic phase is that the basic physical object which align parallel to the nematic director are not individual molecules, but columns of molecules (one-dimensional supramolecular assemblies) which have lost the long-range lateral positional order characteristic of the columnar mesophase. These observations are discussed on the grounds of recent theoretical calculations. Cholesteric-like textures are observed for mixtures of rhodium eicosanoate with the chiral solvent (+) camphene
The structures of the crystalline phase and columnar mesophase of rhodium (II) heptanoate and of its binary mixture with copper (II) heptanoate probed by EXAFS
EXAFS was used to investigate the local structure of the polar spines of rhodium (II) soaps in the columnar liquid crystalline state. It was also used to ascertain the degree of blending of the cores in binary mixtures of rhodium (II) and copper (II) soaps. For the pure rhodium soaps, the columns are shown to result from the stacking of binuclear metal-metal bonded dirhodium tetracarboxylate units bonded to one another by apical ligation of the metal atom of each complex with one of the oxygen atoms of the adjacent molecule. Mixtures of rhodium (II) and copper (II) soaps give a hexagonal columnar mesophase in which pure rhodium and pure copper columns are randomly distributed
Copper K edge EXAFS spectroscopy of the crystalline and columnar phases of copper (II) carboxylates
EXAFS spectra were obtained at the copper-K edge for a series of binuclear copper (II) complexes of fatty acids with 6,12,18 and 22 carbon atoms, in both their crystalline phase and their columnar mesophase. Curve-fitting analysis, using backscattering phases and amplitudes obtained from the structurally characterized copper (II) acetate and copper (II) propionate, gave comparative information on the coordination spheres of copper in both phases. It appeals that the binuclear structure of the complexes and the five-coordination of copper are maintained in the columnar mesophase, with insignificant changes in bond lengths of the binuclear core
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