Jun. 25, 2010
This article briefly describes the basics of both optical and atomic force microscopy, followed by a discussion of some of the technical challenges of integrating these two distinct imaging modalities. In certain cases, the benefits and disadvantages of different approaches to design and integration are discussed. Lastly, a few examples of successful application of these combined imaging modalities are presented. moreJun. 23, 2010
80kV- High Resolution Transmission Electron Microscopy (HRTEM) characterization of micromechanically cleaved graphene shows in real- time atomically resolved dynamics of the carbon atoms in graphene constrictions. During electron irradiation, processes of hole formation generate graphene constrictions and eventually lead to stable single carbon atom chains. Carbon chains also occur between carbonaceous adsorbates and looping along graphene edges. moreMay. 03, 2010
Optical microscopes are subject to the diffraction barrier of light which imposes an optical resolution limit of approximately 200 nm in the imaging plane. dSTORM enables super-resolution imaging with commercially available standard fluorophores and probes at a resolution of ~ 20 nm even in living cells. moreApr. 19, 2010
Hydrothermal decomposition of KMnO4 in the acidic environment in the presence of Fe3+(aq) ions leads to the formation of α-MnO2 nanotubes. The morphology evolution from the sponge-like spheres to the nanotubes as a function of reaction time was imaged by FE-SEM and TEM. The presence of iron in nanotubes was unambiguously confirmed by STEM-EELS measurement across the nanotube diameter.
Introduction moreMar. 31, 2010
Organic and mineral samples, containing light elements like oxygen, nitrogen or beryllium have been analyzed using an attachable X-ray optic with an SDD in SEM. Compared to the measurements without the additional optic, there is a significant increase of the detection sensitivity for X-rays in the energy range below 1 keV. In contrast the spectrum above 1 keV is not affected. The optic can provide similar intensities for low and high energy X-ray lines even at high accelerating voltage.
Introduction moreMar. 24, 2010
We have shown that 50 nm details can be distinguished in x-ray images using a compact laboratory set-up. A novel emitter design inside the x-ray source produces a very small, stable focal spot and prevents diffraction limiting effects. Due to unlimited depth of focus, the source doesn't impose a limit on the specimen size that can be reconstructed by 3D x-ray nano-tomography.
Introduction moreFeb. 22, 2010
Fully understanding the functionality and the complexity of the human central nervous system remains as one of the major open questions in modern science. The Drosophila neuromuscular junction (NMJ) is a widely used and acknowledged model for the analysis of synapse structure and assembly. When considering the size of a Drosophila NMJ synapse of about 500 nm in diameter it appears logical that in order to visualize its spatial architecture the resolution of image acquisition methods needs to be accordingly high. moreFeb. 15, 2010
The view of a tumor as an aberrant tissue whose growth and differentiation is sustained by cancer stem cells is now largely accepted for a wide variety of cancer diseases. Cancer stem cells, as their physiological counterparts, possess the ability to control their fate by maintaining themselves in a quiescent and undifferentiated state or self-renewing to geometrically expand their number. more