Journal of Electron Microscopy - Advance Access

Development of a stage-scanning system for high-resolution confocal STEM

Takeguchi, M., Hashimoto, A., Shimojo, M., Mitsuishi, K., Furuya, K. — 2008-07-04

A stage-scanning system is composed of a specially designed transmission electron microscopy specimen holder equipped with a piezo-driven specimen stage, power supplier and control software. This system enables the specimen to be scanned three-dimensionally, and therefore confocal scanning transmission electron microscopy (STEM) can be performed with a fixed electron-optics configuration. It is demonstrated that stage-scanning confocal STEM images can be obtained with the lateral atomic resolution and the specimen can be moved three-dimensionally with high precision.

Fine structure and mineral components of primary calculi in some human prostates

Kodaka, T., Hirayama, A., Sano, T., Debari, K., Mayahara, M., Nakamura, M. — 2008-07-02

The fine structure of prostatic calculi has not been elucidated yet, although the chemical components were reported in detail. We studied the primary or endogenous calculi removed from eight human prostates by secondary scanning electron microscopy, backscattered electron imaging, energy-dispersive X-ray microanalysis and X-ray diffraction. The primary calculi containing Mg, Zn and S, besides Ca and P were basically classified into four stone groups (I–IV) by fine structure and mineral components. Stone I had the core deposits of calcospherites showing concentric rings and the laminated deposits concentrically around the core. Their deposits were identified as apatite. Stone II was occupied with the calcospherite deposits of apatite although the stone growth showed a rough concentric formation. Stone III contained the core of calcospherites and concentric laminated structures, similar to a smaller type of group I, whereas the wider peripheral region was deposited with needle-like structures, identified as calcium oxalates. Stone IV had the core deposits containing small hexahedral structures, identified as whitlockite, which were surrounded with several incompletely concentric laminated bands of apatite. Whitlockite crystals were also found between the fused large calculi. The initial and formative calculi were basically observed as the deposition of mineralizing spherical structures suggesting variously sized corpora amylaceous bodies. Thus, the primary prostatic calculi of stones I–III will begin from the mineralization of amylaceous bodies as a core, while the organic substances, which form stone IV, might be derived from the simple precipitation of prostatic secretion.

A simple technique for the estimation of the voltage of a transmission electron microscope

Rao, D. V. S. — 2008-06-02

A convergent beam electron diffraction (CBED) technique has been described for the determination of the voltage of a transmission electron microscope (TEM). It involves observing the intersections of HOLZ lines ( ), ( ), ( ) and ( ), in the transmitted disc of the CBED pattern obtained along the [37 37 4] zone axis of silicon. It is suitable for the TEMs with operational voltage in the range of 200 kV, and is also free from the tilt limitations.