Crystal-chemical and structural characterization of fluorapatites in ejecta from Somma-Vesuvius volcanic complex

2011 ◽  
Vol 96 (11-12) ◽  
pp. 1828-1837 ◽  
Author(s):  
M. Rossi ◽  
M. R. Ghiara ◽  
G. Chita ◽  
F. Capitelli
2008 ◽  
Vol 20 (5) ◽  
pp. 713-720 ◽  
Author(s):  
Giuseppina Balassone ◽  
Angela Mormone ◽  
Manuela Rossi ◽  
Alessandro Bernardi ◽  
Martin Fisch ◽  
...  

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 772
Author(s):  
Karla Quiroz-Estrada ◽  
Alessandro Pacella ◽  
Paolo Ballirano ◽  
Miguel Ángel Hernández-Espinosa ◽  
Carlos Felipe ◽  
...  

In this work, the chemical structural characterization of the erionite-type zeolite from Agua Prieta, Sonora, México, was performed on both pristine and Na, Ca, and Mg exchanged samples in order to identify the various modifications due to cation exchange. The samples investigated were those that showed the best behaviour of CO2 and CH4 adsorption at zero coverage levels and the higher values of surface area reported in our previous studies. According to the crystal-chemical formula (Na3.44K1.96Mg0.63Ca0.62)[Al8.21Si27.79O71.85]·29.63H2O, the pristine sample has been classified as erionite-Na. Morphological FE-SEM investigation performed on both pristine (ERIN) and Na-exchanged samples (ERINa3) showed a similar range of fiber diameters (27–37 nm). The chemical analyses of the ion-exchanged samples evidenced the upload of Ca and Mg following ion exchange with Na. Rietveld analysis results allowed the identification of the chemical structural modification caused by the ion exchange process, occurring mainly at the Ca1 site.


Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.


2011 ◽  
Vol 44 (06) ◽  
Author(s):  
A Bracher ◽  
C Kozany ◽  
AK Thost ◽  
F Hausch

Planta Medica ◽  
2014 ◽  
Vol 80 (10) ◽  
Author(s):  
YH Wang ◽  
B Avula ◽  
N Abe ◽  
F Wei ◽  
M Wang ◽  
...  

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