Janet M. S. Skakle

Effect of the proportion of organic material in bone on thermal decomposition of bone mineral: an investigation of a variety of bones from different species using thermogravimetric analysis coupled to mass spectrometry, high-temperature X-ray diffraction, and Fourier transform infrared spectroscopy.

AbstractThermogravimetric analysis linked to mass spectrometry (TGA-MS) shows changes in mass and identifies gases evolved when a material is heated. Heating to 600°C enabled samples of bone to be classified as having a high (cod clythrum, deer antler, and whale periotic fin bone) or a low (porpoise ear bone, whale tympanic bulla, and whale ear bone) proportion of organic material. At higher temperatures, the mineral phase of the bone decomposed. High temperature X-ray diffraction (HTXRD) showed that the main solids produced by decomposition of mineral (in air or argon at 800°C to 1000°C) were β-tricalcium phosphate (TCP) and hydroxyapatite (HAP), in deer antler, and CaO and HAP, in whale tympanic bulla. In carbon dioxide, the decomposition was retarded, indicating that the changes observed in air and argon were a result of the loss of carbonate ions from the mineral. Fourier transform infrared (FTIR) spectroscopy of bones heated to different temperatures, showed that loss of carbon dioxide (as a result of decomposition of carbonate ions) was accompanied by the appearance of hydroxide ions. These results can be explained if the structure of bone mineral is represented by

Hydrothermal synthesis of polymeric metal carboxylates from benzene-1,2,4,5-tetracarboxylic acid and benzene-1,2,4-tricarboxylic acid

{\text{Ca}}_{{\text{10}} - {\text{x}}} {\text{V}}^{{\text{(Ca)}}} _{\text{x}} [({\text{PO}}_{\text{4}} )_{{\text{6}} - {\text{x}} - {\text{y}}} ({\text{HPO}}_{\text{4}} )_{\text{x}} ({\text{CO}}_{\text{3}} )_{\text{y}} ][({\text{OH}})_{{\text{2}} - {\text{x}} - {\text{y}}} ({\text{CO}}_{\text{3}} )_{\text{y}} {\text{V}}^{{\text{(OH)}}} _{\text{x}} ]

Synthesis and characterisation of polymeric metal-ion carboxylates from benzene-1,3,5-tricarboxylic acid with Mn(II), Co(II) or Zn(II) and 2,2-bipyridyl, phenanthroline or a pyridyl-2-(1-methyl-1H-pyrazol-3-yl) derivative

where V(Ca) and V(OH) correspond to vacancies on the calcium and hydroxide sites, respectively, and 2−x−y = 0.4. This general formula is consistent in describing both mature bone mineral (i.e., whale bone), with a high Ca/P molar ratio, lower HPO42− content, and higher CO32− content, and immature bone mineral (i.e., deer antler), with a low Ca/P ratio, higher HPO42−, and lower CO32− content.

Structure and electrical properties of oxygen-deficient hexagonal BaTiO3

OBJECTIVE To determine the water content, collagen content and collagen orientation angle in different regions of sheep lumbar discs. DESIGN A laboratory study of sheep discs obtained from an abattoir. METHODS A total of 21 sheep lumbar discs were obtained from three lumbar spines. Water content was determined by oven drying (60 degrees C) to constant mass. Collagen content was determined by hydroxyproline analysis. Fibre orientation angles were determined by X-ray diffraction. RESULTS Water content increased from 74% of total tissue mass in the outer annulus, to 82% in the inner annulus, to 86% in the nucleus. Collagen content decreased from 30% of total tissue mass in the outer region to 20% in the inner region of the anterior and lateral annulus; it was 16% in the posterior annulus. The orientation angle of the collagen fibres decreased from 59 degrees in the outer region to 56 degrees in the inner region of the anterior and lateral annulus; it was 51 degrees in the posterior annulus. CONCLUSIONS Sheep lumbar intervertebral discs provide a reasonable model for human lumbar intervertebral discs. RELEVANCE Sheep lumbar discs have been used to investigate the effects of removing and replacing the nucleus. These studies indicate that removal of nucleus may lead to further disc degeneration and indicate the material properties required for an implant material. The relevance of these previous studies is increased if human and sheep lumbar discs have a similar composition and structure.

Hydrothermal crystallisation of metal (II) orotates (M=nickel, cobalt, manganese or zinc). Effect of 2,2-bipyridyl, 2,2-dipyridyl amine, 1-methyl-3-(2-pyridyl)pyrazole, phenanthroline and 2,9-dimethyl-1,10-phenanthroline upon structure

Abstract Crystallisation of benzene-1,2,4,5-tetracarboxylic acid or benzene-1,2,4-tricarboxylic acid with divalent metal-ions Co, Mn or Zn and 2,2-bipyridyl gives coordination solids of composition [Co2(C10H2O8)(C10H8N2)2(H2O)] (1), [Co3(C9H3O6)2(C10H8N2)2(H2O)2] (2), [Mn3(C9H3O6)2(C10H8N2)2(H2O)2] (3) or [Zn3(C9H3O6)2(C10H8N2)2(H2O)2] (4). Each has a sheet structure with a distorted octahedral coordination environment.

A triclinic polymorph of benzanilide: disordered molecules form hydrogen-bonded chains

Cortical and trabecular bone are both produced and maintained by the same cell types. At the microscopic scale they have a similar lamellar structure but at a macroscopic scale they are very different. Raman microscopy has been used to investigate compositional differences in the two bone types using bone from standard laboratory mice in physiological conditions. Clear differences were observed when complete spectra were compared by principal component analysis (PCA). Analysis of individual bands showed cortical bone to have compositional characteristics of older bone when compared with trabecular material, possibly due to the higher bone turnover traditionally reported in the trabecular compartment.

Isatin derivatives are reactive electrophilic components for the Baylis–Hillman reaction

A total of 13 new co-ordination solids have been prepared of composition [Co(HBTC)(PHEN)(H2O)] (12), [Mn-3(BTC)(2)(PHEN)(3)] (13), [Mn(HBTC)(6)(H2O)] (14), [Mn(HBTC)(7)(H2O)] (15), [Zn-3(BTC)(2)(6)(3)(H2O)(3)]. 4H(2)O (16), [Zn-(HBTC)(6)(H2O)] (17), [Zn(H2BTC)(2)(6)] (18), [Zn(HBTC)(7)(H2O)] (19), [Zn(HBTC)(8)(H2O)] (20), [Zn-2(HBTC)(2)(9)(2)]. 2H(2)O (21), [Zn(HBTC)(10)(H2O)].H2O (22), [Co(HBTC)(10)(H2O)].H2O (23) and [Co(HBTC)(11)(H2O)] (24) 6 = pyridine-2-(1-methyl-1H-pyrazol-3-yl); 7 = pyridine-2-(1-methyl-4-bromo-1H-pyrazol-3-yl); 8 = pyridine-2-(1-methyl-4-nitro-1H-pyrazol-3-yl); 9 = pyridine-2-(1-methyl-5-trifluoromethyl-1H-pyrazol-3-yl); 10 = pyridine-2-(1-methyl-5-tert-butyl-1H-pyrazol-3-yl); 11 = pyridine-2-(1-methyl-4-nitro-5-tert-butyl-1H-pyrazol-3-yl). Compounds 12, 14, 15 and 24 have similar structures which contain metal atoms in M2O2 rings. Compounds 17, 19 and 20 all contain single stranded coordinative chains. At low temperatures compounds 14 and 15 both have high spin S = 5 ground states.

Synthesis and characterisation of polymeric manganese and zinc 5-hydroxyisophthalates

Rietveld refinements using neutron diffraction data have been used to determine the crystal structure of a series of oxygen-deficient barium titanate powders, BaTi IV 1–x Ti III x O 3–x/2 (0<x<0.30). The powders were prepared by reduction of stoichiometric, tetragonal BaTiO 3 in a vacuum furnace at temperatures above 1300°C and under an oxygen partial pressure of 0.1 mbar. The 6H-BaTiO 3 hexagonal perovskite structure is retained throughout and partial reduction of Ti IV to Ti III is accompanied by the formation of O(1) oxygen vacancies in the h-BaO 3 layers which separate pairs of occupied face-sharing octahedra, Ti 2 O 9 . There is no evidence of O(2) vacancies associated with corner sharing TiO 6 octahedra. The Ti(2)-Ti(2) separation within face sharing dimers increases from 2.690(4) A for x=0 to 2.7469(30) A for x=0.30. BaTiO 2.85 is a band-gap semiconductor at 300 K with a resistivity of ca. 1 Ω cm and activation energy 0.16 eV. A switch in conduction mechanism to variable range hopping (VRH) of electrons between Ti III and Ti IV ions occurs on cooling below 240 K.