Digital holography and 3-D imaging

This feature issue on Digital Holography and 3-D Imaging comprises 15 papers on digital holographic techniques and applications, computer-generated holography and encryption techniques, and 3-D display. It is hoped that future work in the area leads to innovative applications of digital holography and 3-D imaging to biology and sensing, and to the development of novel nonlinear dynamic digital holographic techniques.     

Thermal activation and saturation of ion beam sculpting

We report a material-dependent critical temperature for ion beam sculpting of nanopores in amorphous materials under keV ion irradiation. At temperatures below the critical temperature, irradiated pores open at a rate that soon saturates with decreasing temperature. At temperatures above the critical temperature, the pore closing rate rises rapidly and eventually saturates with increasing temperature. The observed behavior is well described by a model based on adatom diffusion, but is difficult to reconcile with an ion-stimulated viscous flow model.     

FLIM of NAD(P)H in Lymphatic Nodes Resolves T-Cell Immune Response to the Tumor

Assessment of T-cell response to the tumor is important for diagnosis of the disease and monitoring of therapeutic efficacy. For this, new non-destructive label-free methods are required. Fluorescence lifetime imaging (FLIM) of metabolic coenzymes is a promising innovative technology for the assessment of the functional status of cells. The purpose of this work was to test whether FLIM can resolve metabolic alterations that accompany T-cell reactivation to the tumors. The study was carried out on C57Bl/6 FoxP3-EGFP mice bearing B16F0 melanoma. Autofluorescence of the immune cells in fresh lymphatic nodes (LNs) was investigated. It was found that fluorescence lifetime parameters of nicotinamide adenine dinucleotide (phosphate) NAD(P)H are sensitive to tumor development. Effector T-cells in the LNs displayed higher contribution of free NADH, the form associated with glycolysis, in all tumors and the presence of protein-bound NADPH, associated with biosynthetic processes, in the tumors of large size. Flow cytometry showed that the changes in the NADH fraction of the effector T-cells correlated with their activation, while changes in NADPH correlated with cell proliferation. In conclusion, FLIM of NAD(P)H in fresh lymphoid tissue is a powerful tool for assessing the immune response to tumor development.     

USE OF SODA FELDSPAR IN WHITEWARE BODIES *

A comparative study is presented of a soda feldspar produced by a flotation process and of two potash feldspars when tested alone and made up in semivitreous and vitreous bodies. The investigation was divided into two parts, (1) a laboratory study and (2) plant trials on semivitreous dinnerware and on vitreous sanitary porcelain. From the results of the investigation, it was concluded that (1) it should be possible to substitute soda feldspar for North Carolina potash feldspar in semivitreous bodies containing not more than 12% feldspar, on an equal basis, with no significant change in properties except possibly crazing resistance; where crazing occurs, a slight modification of the regular glaze to give it a lower thermal expansion should correct the trouble; the formula of one modified glaze for this purpose is suggested; and (2) the substitution of soda feldspar for potash feldspar in sanitary porcelain and other similar vitreous whiteware bodies will doubtless require a reduction in amount in order to duplicate the vitrification and other properties of the potash-feldspar body in use; a modification of the regular glaze to fit the soda-feldspar body will probably be required; and the castability and control of casting slips should not be affected by the use of soda feldspar in place of potash feldspar.     

GRAIN SIZE OF WHITEWARE CLAYS AS DETERMINED BY THE ANDREASEN PIPETTE *

The Andreasen pipette method of determining grain sizes by sedimentation is a refinement of the ordinary pipette method. The apparatus was selected for the determination of grain size in a general study of clay casting slips after consideration of other methods. It permits precise results but requires more time and precision than some other methods. Graphs are presented for comparison of typical American kaolins and ball clays and English china clays and ball clays.