Tissue section analysis: Feature selection and image processing

Three examples are given of the state-of-the-art of pattern recognition as regards the analysis of images of human and animal tissue: (1) the counting of cell nuclei of normal and abnormal rabbit kidney; (2) the detection of boundaries of endothelial cells of the living human cornea; and (3) the differentiation of normal and abnormal cells in the human liver. The methodology employed is that of cellular logic matched filtering using the Carnegie-Mellon SUPRPIC image processing system.     

An Adhesion Paradox

In the study of the adhesion of solids, a curious paradox has arisen. The paradox concerns the strength of adhesive bonds in two test geometries, the pull-off and the peel test, illustrated in Figure 1.     

Ultrasonography of renal sinus lipomatosis

Gray scale B-scans in renal sinus lipomatosis show a variety of features which must be differentiated from clinically significant pathological processes. Normal kidneys show dense homogeneous central echoes. In renal sinus lipomatosis, however, the central echoes are divided and become more sparse (Type I), interspersed with small relatively echo-free areas (Type II), or outline a single relatively echo-free area resembling a mass (Type III). In contrast to similar features in hydronephrosis or multiple cysts, the relatively echo-free areas in lipomatosis are ill-defined and do present several weak internal echoes.     

Targeted,Needle‐Free Vaccinations in Skin using Multilayered,Densely‐Packed Dissolving Microprojection Arrays

Targeting of vaccines to abundant immune cell populations within our outer thin skin layers using miniaturized devices—much thinner than a needle and syringe, could improve the efficacy of vaccines (and other immunotherapies). To meet this goal, a densely packed dissolving microprojection array (dissolving Nanopatch) is designed, achieving functional miniaturization by 1) formulating small microneedles (two orders of magnitude smaller than a standard needle and syringe) and 2) multiple layering of the payload within microprojections with tight tolerances (of the order of a micrometer). The formulation method is suitable to many vaccines because it is without harsh or complex chemical processes, and it is performed at low temperatures and at a neutral pH. When the formulated dNPs are applied to skin, consistent and robust penetration is achieved, rapidly targeting the skin strata of interest (<5 min; significantly faster than larger dissolving microneedles that have been previously reported). Resultant diffusion is significantly enhanced within the dermis compared with the epidermis. Using two different antigens (ovalbumin and a commercial trivalent influenza vaccine [Fluvax2008]), the administration of these dissolving patches generate robust systemic immune responses in a mouse model. To the authors' knowledge, this is the first report of successful vaccination with any form of dissolving microneedles. The patches made by this method therefore have the potential for pain‐free, needle‐free, and effective vaccination in humans.     

Magnetic resonance diffusion imaging of ovarian masses: a first experience with 12 cases

Objective: The objective of the study was to determine the feasibility of using apparent diffusion coefficient (ADC) measurement for the differential diagnosis of malignancy in ovarian masses. Materials and methods: Twelve cases involving ovarian masses were imaged using spin echo diffusion magnetic resonance imaging (MRI). Five cases involved malignant ovarian masses, on the basis of postoperative histologic examination, and the rest involved benign masses. The ovarian masses were imaged in vivo (10 cases) before surgery and ex vivo (8 cases) after surgical resection. Diffusion-weighted data were corrected for motion using the phase data from unweighted data in nine cases. Multifactorial analysis of variance was used to evaluate the effects of malignancy, location (in vivo versus ex vivo), and motion correction on the measurement of ADC intensity and texture. Results: Motion correction caused an undesirable spatial smoothing of the ADC maps and a significant interaction ( ) was found between location and motion correction. ADC value ( ) and texture ( ) differences were found between malignant and nonmalignant ovarian masses. Conclusion: Measurement of ADC intensity and texture has the potential to differentially diagnose malignancy in individual ovarian masses if the problem of image motion artifact can be eliminated through the use of faster imaging sequences.Acknowledgements. The cooperation of Dr. Vance Chow in the acquisition of the in vivo diffusion MRI data is gratefully acknowledged. Thanks to Ron Borowsky for discussions on the statistical data analysis. Data management, final data analysis, and figure preparation was completed by Jennifer Hadley. This work was supported by the Canadian Institutes for Health Research (CIHR) and the Saskatchewan Health Services Utilization and Research Commission (HSURC).     

Novel temperature measurement method & thermodynamic investigations of amorphous polymers during high rate deformation

Polymers are frequently used in applications in which they may be exposed to high rate or impact loading, and there is growing industrial importance in understanding their mechanical behavior at different strain rates. An important aspect of this is the temperature rise due to adiabatic conditions in high rate loading. This paper describes research that has been performed to measure the temperature rise that occurs in specimens undergoing rapid deformation. A novel thermocouple design is presented and applied to PMMA and 20 wt% DINP-plasticized PVC, deformed at moderate and high strain rates. The measurements are accompanied by investigations of strain energy.