Crystal Chemistry of Lamellar Calcium Aluminate Sulfonate Hydrates: Fixation of Aromatic Sulfonic Acid Anions

Crystal chemistry of manganese-containing perovskites related to calcium aluminate cements

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767310099071 ◽

2010 ◽

Vol 66 (a1) ◽

pp. s41-s41

Author(s):

S. Stöber ◽

G. Redhammer ◽

O. Prokhnenko ◽

S. Schorr ◽

H. Pöllmann

Keyword(s):

Crystal Chemistry ◽

Calcium Aluminate

Download Full-text

Electron Microscopy of Mycoplasma Pneumoniae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065341 ◽

1971 ◽

Vol 29 ◽

pp. 258-259 ◽

Cited By ~ 1

Author(s):

E. S. Boatman ◽

G. E. Kenny

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Growth Phase ◽

Hela Cells ◽

Sulfonic Acid ◽

Gamma Globulin ◽

Horse Serum ◽

Morphological Aspects ◽

The Family

Information concerning the morphology and replication of organism of the family Mycoplasmataceae remains, despite over 70 years of study, highly controversial. Due to their small size observations by light microscopy have not been rewarding. Furthermore, not only are these organisms extremely pleomorphic but their morphology also changes according to growth phase. This study deals with the morphological aspects of M. pneumoniae strain 3546 in relation to growth, interaction with HeLa cells and possible mechanisms of replication.The organisms were grown aerobically at 37°C in a soy peptone yeast dialysate medium supplemented with 12% gamma-globulin free horse serum. The medium was buffered at pH 7.3 with TES [N-tris (hyroxymethyl) methyl-2-aminoethane sulfonic acid] at 10mM concentration. The inoculum, an actively growing culture, was filtered through a 0.5 μm polycarbonate “nuclepore” filter to prevent transfer of all but the smallest aggregates. Growth was assessed at specific periods by colony counts and 800 ml samples of organisms were fixed in situ with 2.5% glutaraldehyde for 3 hrs. at 4°C. Washed cells for sectioning were post-fixed in 0.8% OSO4 in veronal-acetate buffer pH 6.1 for 1 hr. at 21°C. HeLa cells were infected with a filtered inoculum of M. pneumoniae and incubated for 9 days in Leighton tubes with coverslips. The cells were then removed and processed for electron microscopy.

Download Full-text

An HREM study of superstructures in Ca4Al6SO16

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017846x ◽

1990 ◽

Vol 48 (4) ◽

pp. 1066-1067

Author(s):

Y.G. Wang ◽

H.Q. Ye ◽

K.H. Kuo

Keyword(s):

Calcium Aluminate ◽

Structural Model ◽

Bright Spot ◽

Sulphur Atom ◽

Synthetic Compound ◽

Space Group ◽

Lattice Images ◽

Cubic Structure ◽

Good Agreement

A synthetic compound Ca4Al6SO16 (usually abbreviated as C4A3S) obtained by mixing CaO, A12O3 and CaSO4 powders and finally sintered at 1380°C is a cement with excellent hydraulicity and greatly expanding in application. It is hydralysed rapidly by water to form predominatly calcium aluminate hydrates and therefore unlikly to occur naturally, although structurally it may be regarded as an end member of the sodalite-hauynite series of naturally occuring minerals. C4A3S has a cubic structure with ao=9.19Å and space group . Fig.1 is the projection viewed down axis, in which there are two sets of 8C position in , namely CaI and CaII, occupied by the calcium atoms, respectively, and the ratio of occupations in these two sets of positions is about 3:1. This suggests that the calcium atoms can freely occupy these sites in various degrees and usually they almost locates on the CaI positions. A through-focus series of the lattice images were found in good agreement with the simulated ones. Each bright spot in the image taken at Scherzer defocus correspounds to a colunm of sulphur atom in the structural model (Fig.1).

Download Full-text