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For sectioned biologic tissues, atomic force microscopy (AFM) topographic images alone hardly provide adequate information leading to revealing biological structures. We demonstrate that phase imaging in amplitude-modulation AFM is a powerful tool in mapping structures present on the surface of unfixed rat brains sections. The contrast in phase images is(More)
Chinese adults literate only in Chinese characters could not add or delete individual consonants in spoken Chinese words. A comparable group of adults, literate in alphabetic spelling as well as characters, could perform the same tasks readily and accurately. The two groups were similar in education and experience but differed in age and consequently in(More)
Condensed octadecylphosphonic acid (OPA) dimers, i.e., two OPA molecules combined with the loss of a water molecule, were detected by time-of-flight secondary ion mass spectrometry (TOF-SIMS) on OPA self-assembled monolayers (SAMs) that are only weakly bonded on the native oxide layer of a silicon wafer. In contrast, these condensed dimers were absent on(More)
Liquid 1-decanethiol was confined on an atomic force microscope (AFM) tip apex and the effect was investigated by measuring amplitude-distance curves in dynamic force mode. Within the working distance in the dynamic force mode AFM, the thiol showed strong interactions bridging between a gold-coated probe tip and a gold-coated Si substrate, resulting in(More)
A low-energy hydrogen bombardment method, without using any chemical additives, has been designed for fine tuning both physical and chemical properties of molecular thin films through selectively cleaving C-H bonds and keeping other bonds intact. In the hydrogen bombardment process, carbon radicals are generated during collisions between C-H bonds and(More)
We describe a simple experimental approach for delivering self-assembled monolayers (SAMs) of octadecylphosphonic acid (OPA) on many oxide surfaces using a nonpolar medium with a dielectric constant around 4 (e.g., trichloroethylene). This approach readily results in the formation of full-coverage OPA SAMs on a wide variety of oxide surfaces including(More)
Loading antibiotics in a biodegradable polymer matrix is an excellent way to control its release kinetics, which eliminates side effects caused by conventional administrations of the drug. This approach is especially beneficial for bone regeneration when using a scaffold made of a biodegradable polymer loaded with drug agents capable of controllable(More)
As determined by scratch tests, self-assembled monolayers (SAMs) of octadecylphosphonic acid (OPA) on a muscovite mica substrate were found to be mechanically robust and to serve as a lubricant to protect the underlying mica substrate. For comparison purposes, three polymer films were subjected to scratch tests under the same conditions. The scratch tests(More)
RATIONALE In order to determine the degree of cross-linking on the surface and its variations in a nanometer-scale depth of organic materials, we developed an approach based on time-of-flight secondary ion mass spectrometry (TOF-SIMS), which provides rich chemical information in the form of fragment ions. TOF-SIMS is extremely surface-sensitive and capable(More)