Home About us Contact
|
Home About us Contact | ||
|
|
||
Imaging Modes (imaging + mode)
Selected AbstractsScanning Ion Conductance MicroscopyIMAGING & MICROSCOPY (ELECTRONIC), Issue 2 2007Imaging Technique Integrating Shear Force Distance Control Abstract Scanning ion conductance microscopy (SICM) is an imaging technique, measuring conductance through a nanometer-sized pipette tip opening that is brought close to a sample surface submerged in electrolyte solution. In combination with an integrated shear force distance control, the local ion conductance can be measured independently of and simultaneously with topography. The design of a shear-force-controlled SICM is presented and a new imaging mode that significantly improves image quality is discussed. [source] Morphology of phase-separated thermotropic layers based on UV cured acrylate resinsPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 12 2009Katharina Resch Abstract In this paper, relationships between the scattering domain parameters (size and shape) and the light-shielding properties of thermotropic systems with fixed domains (TSFD) are established. Specific focus is given to the effect of additive type on the formation of scattering domain size. Various functional layers are prepared by a variation of thermotropic additives. Scattering domains are investigated applying high resolution Atomic Force Microscopy (AFM) in a phase imaging mode. Thermotropic layers formulated with additive types exhibiting a short chain length display roughly spherical scattering particles with dimensions between 0.5 and 3,µm and a moderate reduction in hemispheric solar transmittance along with a significant increase in diffuse solar transmittance above the switching threshold. Additive types with long-chain molecules develop anisotropic scattering domains resembling distorted disks with a diameter up to 50,µm and a thickness between 100 and 400,nm. Disk-like scattering features yield enhanced light-shielding properties. Copyright © 2009 John Wiley & Sons, Ltd. [source] Brief communication: Paleohistopathological analysis of pathology museum specimens: Can periosteal reaction microstructure explain lesion etiology?AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009Darlene A. Weston Abstract The assertion that the microstructure of periosteal new bone formation can be used to differentiate between disease etiologies (Schultz: Yrbk Phys Anthropol 44 2001 106,147; Schultz: Identification of pathological conditions in human skeletal remains, 2nd ed. London: Academic Press 2003 73,109) was tested in a pilot-study, using diagnosed bone specimens from St George's Hospital Pathology Museum, London, UK. Embedded bone specimens exhibiting pathological periosteal new bone formation were examined using scanning electron microscopy in back-scattered electron imaging mode (SEM-BSE). The results suggest that several histological features (i.e. Grenzstreifen, Polsters, and sinuous lacunae) deemed to be diagnostic of specific pathological conditions are of no specific diagnostic value, as they are encountered in pathological conditions of differing disease etiology. These results tie in with a previous investigation demonstrating a lack of diagnostic qualitative or quantitative characteristics seen in the macroscopic and radiographic appearance of periosteal reactions (Weston: Am J Phys Anthropol 137 2008 48,59). Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Quantitative structure retrieval using scanning transmission electron microscopyACTA CRYSTALLOGRAPHICA SECTION A, Issue 4 2005S. D. Findlay A method is described that reconstructs the projected object potential using data recorded in the coherent imaging mode of a scanning transmission electron microscope. The technique is applicable in the presence of multiple scattering. It is not required that the thickness is known. Model examples exploring the nature of the data set required, the stability of the algorithm and the limitations on resolution are provided. [source] Correlative 3D Microscopy: CLSM and FIB/SEM TomographyIMAGING & MICROSCOPY (ELECTRONIC), Issue 3 2008A Study of Cellular Entry of Vaccinia Virus Abstract Subcellular structural investigation on single cells or tissue samples requires the coupling of optimal structural preservation with detailed imaging at the light and electron microscopic level. To apply light microscopy (FLM, CLSM) and electron microscopy (SEM, FIB/SEM, TEM) imaging modes to the identical sample area has become available with the establishment of chemical preparation, or freeze-substitution protocols after high pressure freezing, adapted to retain fluorophores. One and the same structure can now be investigated at mm to nm range in 2D and 3D in a multimodal set-up [1, 2]. In combination with live cell imaging prior to immobilisation, this approach becomes a powerful tool in life science, e.g. in the development of new anti-viral strategies, as this requires detailed information on the replication cycle of viruses and their interaction with their host cells. [source] Effect of lateral target motion on image registration accuracy in CT-guided helical tomotherapy: A phantom studyJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 3 2010J Medwig Summary Optimisation of imaging modes for kilovoltage CT (kVCT) used for treatment planning and megavoltage CT (MVCT) image guidance used in ungated helical tomotherapy was investigated for laterally moving targets. Computed tomography images of the QUASARÔ Respiratory Motion Phantom were acquired without target motion and for lateral motion of the target, with 2-cm peak-to-peak amplitude and a period of 4 s. Reference kVCT images were obtained using a 16-slice CT scanner in standard fast helical CT mode, untagged average CT mode and various post-processed 4D-CT modes (0% phase, average and maximum intensity projection). Three sets of MVCT images with different inter-slice spacings of were obtained on a Hi-Art tomotherapy system with the phantom displaced by a known offset position. Eight radiation therapists performed co-registration of MVCT obtained with 2-, 4- and 6-mm slice spacing and kVCT studies independently for all 15 CT imaging combinations. In the investigated case, the untagged average kVCT and 4-mm slice spacing for the MVCT yielded more accurate registration in the transverse plane. The average residual uncertainty of this combination of imaging procedures was 0.61 ± 0.16 mm in the longitudinal direction, 0.45 ± 0.14 mm in the anterior,posterior direction and insignificant in the lateral direction. Manual registration of MVCT,kVCT study pairs is necessary to account for a target in significant lateral motion with respect to bony structures. [source] Near-field scanning optical microscopy and near-field induced photocurrent investigations of buried heterostructure multiquantum well lasersJOURNAL OF MICROSCOPY, Issue 3 2005M. P. ACKLAND Summary Buried heterostructure multiquantum well laser devices are investigated utilizing a near-field scanning optical microscope to characterize and correlate the surface topography, optical output and electronic properties of the device. Near-field photocurrent imaging has been used to accurately measure the unbiased buried heterostructure multiquantum well device in cross-section, successfully revealing the distribution of pn -junctions and their associated fields. Moreover, this has been accurately correlated with the physical structure of the device determined by simultaneous shear-force imaging of the surface. Topographic structure is manifested as a result of strain relaxation (,10,10 m) of the cleaved cross-section. These imaging modes are similarly correlated with the optical output of the operational device mapped with 50 nm lateral resolution. The collection-mode measurements detected electroluminescence external to the active region, highlighting the existence of carrier recombination away from the multiquantum well device region. The combination and correlation of different near-field scanning optical microscope imaging modes proved powerful in the analysis of the buried heterostructure multiquantum well device, and was shown to assist in the identification of current leakage pathways within the structure. [source] Magnetic Resonance Imaging is Superior to Cardiac Scintigraphy to Identify Nonresponders to Cardiac Resynchronization TherapyPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009MIKI YOKOKAWA M.D. Background: Left ventricular (LV) postero-lateral scar and total scar burden are factors responsible for a poor response to cardiac resynchronization therapy (CRT). Contrast-enhanced magnetic resonance imaging (CMR) and 99mTc-2-methoxy isobutyl isonitrile single photon emission computed tomography (SPECT) perfusion imaging are widely used to detect myocardial scar tissue; however, their ability to detect regional scars and predict a positive response to CRT has not been fully evaluated. Methods: CMR and SPECT were performed in 17 patients with dilated cardiomyopathy (DCM) and seven patients with ischemic cardiomyopathy (ICM) before CRT. All images were scored, using a 17-segment model. To analyze the LV scar regions by CMR, we assessed the transmural delayed enhancement extent as the transmural score in each segment (0 = no scar, 4 = transmural scar). Similarly, a perfusion defect score was assigned to each segment by SPECT (0 = normal uptake, 4 = defect). Results: By both SPECT and CMR imaging, the total scar score was significantly higher in the ICM than in the DCM group. An LV postero-lateral wall scar region was detected using both imaging modes. By SPECT imaging, the percentage of regional scar score in the LV inferior wall was significantly higher in the DCM than in the ICM group. Conclusions: By SPECT imaging in the DCM group, severe perfusion defects, due to attenuation artifacts, were frequently observed in the LV inferior wall, resulting in the overestimation of scar tissue. CMR identified nonresponders to CRT more reliably than SPECT in patients with DCM. [source] | ||||||||||