AFM studies

Al-Obaidi A H R, Rigby S J, Hegarty J N M, Bell S E J and McGarvey J J 1996 Direct formation of silver and gold metal liquid-like films (MELLFS) from thiols and sols without organic solvents SERS and AFM studies ICORS 96 XVth Int. Conf on Raman Spectroscopy ed S A Asher and P B Stein (New York Wiley) pp 590-1... 

Koinuma M and Uosaki K 1996 Atomic structure of bare p-GaAs(IOO) and electrodeposited Cu on p-GaAs (100) surfaces in H2SO4 solutions An AFM study J. Eiectroanai. Chem. 409 45-50... 

Recent developments have allowed atomic force microscopic (AFM) studies to follow the course of spherulite development and the internal lamellar structures as the spherulite evolves [206-209]. The major steps in spherulite formation were followed by AFM for poly(bisphenol) A octane ether [210,211] and more recently, as seen in the example of Figure 12 for a propylene 1-hexene copolymer [212] with 20 mol% comonomer. Accommodation of significant content of 1-hexene in the lattice allows formation and propagation of sheaf-like lamellar structure in this copolymer. The onset of sheave formation is clearly discerned in the micrographs of Figure 12 after crystallization for 10 h. Branching and development of the sheave are shown at later times. The direct observation of sheave and spherulitic formation by AFM supports the major features that have been deduced from transmission electron and optical microscopy. The fibrous internal spherulite structure could be directly observed by AFM. 

Schmidt, Alkire and Gewirth reported an extensive in-situ AFM study of copper deposits formed in acid sulfate solution, containing 0.05 M CuSCL, with and without additives [74], The applied current density was 0.8 mA/cm2. Without additive, the... 

Atomic force microscopy (AFM) can be used to obtain high-resolution imagery of molecular orientation and ordering for materials adsorbed onto substrates. Early AFM studies on gluconamides were hampered by the tendency of the fibers to unravel on substrates forming bilayer sheets.41 These layers showed the head-to-tail packing of a monolayer which is similar to the crystal structure reported for anhydrous gluconamides.38 A procedure to retain the fiber networks on surfaces with the addition of a small fraction of... 

Polymorphism also seems to influence the growth rate of filaments. In their AFM study of Sup35pNM filaments involving a compilation of the growth rates measured on many in dividual filaments, DePace and Weissmann (2002) found different classes, for example, fast on both ends, slow at one end, and so on (Section V.A Fig. 8). They were able to show in several rounds of growth analysis that growth rate is an intrinsic property for each class of filaments. 

This chapter describes the use of AFM as a methodology for characterizing dendritic macromolecules and their self-assembled films. Systematic AFM studies of the PAMAM dendrimers properties (e.g. their size, shape, rigidity, packing textures and molecular weight calculations) will be fully addressed in this chapter. 

As discussed in section 6.1, a relatively exhaustive HRTEM and AFM study was conducted by Mitter-dorfer and Gauckler of how secondary phases form at the LSM/YSZ boundary and how these phases effect electrode kinetics. This study placed the time scale for cation-transport processes in the correct range to be consistent with the theory described above. However, while all this may be interesting and useful speculation, to date no in-depth studies of the LSM surface as a function of A/B ratio, polarization history, or other factors have been performed which would corroborate any of these hypotheses. Such a study would require combining detailed materials characterization with careful electrochemical measurements on well-defined model systems. Given the... 

AFM studies of biochemically manipulated or reconstituted chromatin fibers... 

Several reports have used AFM imaging, in conjunction with traditional biochemical methods, to address this question (it must be noted that an in-depth AFM study of this issue is still to be performed). The AFM data suggest thus far that hyperacetylated histones isolated from cells treated with histone deacetylase inhibitors produce beads-on-a string structures somewhat more extended than those obtained using histones purified from control cells [37,38], in agreement with EM imaging results obtained on circular chromatin templates [49]. In addition, acetylation seems to enhance the non-random nucleosome-loading behavior seen in subsaturated nucleosomal arrays (see above, and Table 1). 

The substrates used for DNA immobihsation can be, at the level of the AFM analysis, either rigid (e.g., glass) or flexible (e.g., polymers). An atomically flat surface is preferable, but sometimes this is difficult to achieve. The DNA immobilisation mechanisms can be (i) physio-sorption, (ii) charge complementarity and (iii) covalent binding. Depending on the actual objective of the AFM study, each combination of the surface-immobilisation mechanism has both benefits and drawbacks. 

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