AFM of cocrystals: Atomic force microscopy can be used to observe phase changes at crystal surfaces where the transformation is accompanied by a change in the spacing between layers of molecules. The conversion of a metastable polymorph of the caffeine-glutaric acid cocrystal into the thermodynamically stable form was analyzed continuously in situ using intermittent-contact-mode atomic force mi...

Laser light scattering by a drying droplet of water fullerene suspension several micrometers in size was studied. Two light wavelengths were used. The evolution of refractive index and radius of the droplet was investigated. Resonant scattering was identified and analyzed. Some conclusions were drawn on the microscopic properties of the suspension. Supplementing measurements of samples obtained...

Metal tips decorated with CO molecules have paved the way for an impressively high resolution in atomic force microscopy (AFM). Although Pauli repulsion and the associated CO tilting play a dominant role at short distances, experiments on polar and metallic systems show that electrostatic interactions are necessary to understand the complex contrast observed and its distance evolution. Attempts...

Atomic force microscopy (AFM) uses a pyramidal tip attached to a cantilever to probe the force response of a surface. The deflections of the tip can be measured to ~10 pN by a laser and sectored detector, which can be converted to image topography. Amplitude modulation or "tapping mode" AFM involves the probe making intermittent contact with the surface while oscillating at its resonant frequen...

The dynamic assembly and disassembly of microtubules and the mechanical properties of these polymers are essential for many key cellular processes. Mathematical and computational modeling, especially coupled mechanochemical modeling, has contributed significantly to our understanding of microtubule dynamics. However, critical discrepancies exist between experimental observations and modeling re...

Atomic force microscopy and single-molecule force spectroscopy were combined to image and manipulate purple membrane patches from Halobacterium salinarum. Individual bacteriorhodopsin molecules were first localized and then extracted from the membrane; the remaining vacancies were imaged again. Anchoring forces between 100 and 200 piconewtons for the different helices were found. Upon extractio...

The aim of the study was to synthesize silver nanoparticles by using filamentous fungus Penicillium sp. The fungal culture was isolated from the soil samples collected from agriculture fields in Vellore district, Tamil Nadu, India. The purified fungal isolates were inoculated in minimal medium and incubated at room temperature for three days. For the synthesis of silver nanoparticles, 50 ml of ...

Mass energy absorption coefficients and effective atomic numbers for photon energy absorption, ZPEAeff have been calculated in the energy range from 1 keV to 20 MeV for human tissues, Adipose Tissue, Blood Whole, Bone Cortical, Brain Grey/White Matter, Breast Tissue, Eye Lens, Lung Tissue, Muscle Skeletal, Ovary, Testis, Soft Tissue. Mass energy absorption coefficients and effective atomic numb...