Radiochemical determination of protactinium-231 in environmental and biological materials

1978 ◽  
Vol 50 (11) ◽  
pp. 1559-1571 ◽  
Author(s):  
Claude W. Sill
Keyword(s):  
Biological Materials ◽  
Radiochemical Determination

Enhanced information from biological materials through technological improvements in cryo-electron microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 788-789
Author(s):  
Marc J.C. de Jong ◽  
Wim M. Busing ◽  
Max T. Otten
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Biological Materials ◽  
Electron Crystallography ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
The Many ◽  
Technological Improvements ◽  
Beam Damage

Biological materials damage rapidly in the electron beam, limiting the amount of information that can be obtained in the transmission electron microscope. The discovery that observation at cryo temperatures strongly reduces beam damage (in addition to making it unnecessaiy to use chemical fixatives, dehydration agents and stains, which introduce artefacts) has given an important step forward to preserving the ‘live’ situation and makes it possible to study the relation between function, chemical composition and morphology.Among the many cryo-applications, the most challenging is perhaps the determination of the atomic structure. Henderson and co-workers were able to determine the structure of the purple membrane by electron crystallography, providing an understanding of the membrane's working as a proton pump. As far as understood at present, the main stumbling block in achieving high resolution appears to be a random movement of atoms or molecules in the specimen within a fraction of a second after exposure to the electron beam, which destroys the highest-resolution detail sought.

Separation and determination of Cd in biological materials by continuous-flow fluid extraction coupled to flow-injection ICP-AES

1995 ◽  
Vol 351 (8) ◽  
pp. 802-804 ◽  
Author(s):  
E. Vereda Alonso ◽  
M. T. Siles Cordero ◽  
A. Garc�a de Torres ◽  
J. M. Cano Pav�n
Keyword(s):  
Flow Injection ◽  
Continuous Flow ◽  
Biological Materials ◽  
Fluid Extraction
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