Cell-graph coloring for cancerous tissue modelling and classification

In traditional cancer diagnosis process, pathologists manually examine biopsies to make diagnostic assessments. The assessments are largely based on visual interpretation of cell morphology and tissue distribution, lacking of quantitative measures. Therefore, they are subject to considerable inter-observer variability. To circumvent this problem, numerous studies aim at quantifying the characteristics of cancerous cells and tissues that distinguish them from their counterparts. Such quantification facilitates to design automated systems that operate on quantitative measures, and in turn, to reduce the inter-observer variability. There is a computational model available that relies solely on the topological features of cancerous cells in a tumor. Despite their complex dynamic nature, the self-organizing clusters of cancerous cells exhibit distinctive graph properties that distinguish the cancerous tissue from non-cancerous tissues; e.g. from a healthy tissue or an inflamed tissue. It is difficult to distinguish a cancerous tissue sample visually from an inflamed one. It is possible to construct a graph of the cells (cell graph) based on the location of the cells in the low-magnification image of a tissue sample surgically removed from a human patient. Assuming the cells present in a sample as the vertices of the cell graphs and the edges connecting those vertices/cells we can construct the cell graphs. There is a possibility of implementing the technique of using cell graphs to detect cancerous sample biopsies using some simple or a little bit complex computational techniques. Here possibly a new way is going to be introduced in this field, which is an application of graph coloring using the cell graphs to classify the normal, cancerous and inflamed sample biopsies. This work intends to automate the solution to the problem of identifying cancerous sample biopsies applying customized graph Coloring method solving by Genetic Algorithm on the cell graphs.     

Chemical surface treatment of ultrahigh molecular weight polyethylene for improved adhesion to methacrylate resins

Ultrahigh molecular weight polyethylene (UHMWPE) has high yield strength and modulus, but is nonpolar and chemically inert. For it to be used as an effective reinforcing agent for composites, methods to make the UHMWPE wettable or capable of reaction with the matrix are critical. In the current work, Spectra 900? (UHMWPE) fibers were surface modified by swelling in p‐xylene with: (1) methylmethacrylate (MMA) monomer; (2) PMMA; (3) camphorquinone (CQ); (4) 3‐methacryloxypropyltrichlorosilane (Cl‐MPS); (5) trimethoxysilyl modified polyethylene, N‐(triethoxysilylpropyl)‐dansylamide (fluorescent silane), or octadecyltrimethoxy silane (OMS), followed by hydrolysis and reaction with Cl‐MPS; and (6) by coating with SiO₂ films followed by reaction with MPS. These modifiers were used to improve wettability and provide sites for chemical interactions with the resin matrix. Beads of resin [60/40 BisGMA‐TEGMA (bis‐phenol A bis‐(2‐hydroxypropyl) methacrylate and tri(ethylene glycol) dimethacrylate)] were light‐cured around the treated fibers and the improvement in adhesion was tested by microbond shear strength (τ) tests. The improvements were comparable to those reported by acid etching and plasma treatments. The OMS, fluorescent silane, and SiO₂/Cl‐MPS treatments yielded the best results, that is fourfold increases in τ compared with untreated fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1564–1572, 2005     

Chrysamine-G, a lipophilic analogue of Congo red, inhibits A beta-induced toxicity in PC12 cells

Increasing evidence suggests that deposition of amyloid-beta (A beta) peptide leads to neurodegeneration in Alzheimer's disease. Congo red, a histologic dye that binds to amyloid has previously been shown to diminish the toxic effects of A beta in cell culture. Since Congo red is too highly charged to enter the brain in significant quantities, a lipophilic derivative, Chrysamine-G, was tested for the ability to attenuate A beta[25-35]-induced toxicity in PC12 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Chrysamine-G showed a concentration-dependent inhibition of A beta[25-35]-induced toxicity. This protective effect became significant at 0.2 microM, a concentration very close to the Ki for Chrysamine-G binding to synthetic A beta (0.37 microM). A decarboxy derivative of Chrysamine-G, which does not bind to A beta, also did not protect against A beta-induced toxicity. The protective effects of Chrysamine-G may relate to its ability to bind directly to A beta and may involve other post-binding effects as well.     

Sediment Threshold under Stream Flow on Horizontal and Sloping Beds

A model is presented to determine the threshold shear stress for noncohesive sediment (uniform and nonuniform) motion on horizontal and stream-wise sloping sedimentary beds, under a unidirectional steady-uniform streamflow. Hydrodynamic and particle-mechanic forces on a solitary sediment particle, resting over a sedimentary bed under the slip-spinning condition, are analyzed including the effect of turbulent fluctuations. Hydrodynamic forces such as drag, shear lift, and Magnus lift are taken into consideration. The drag coefficient is determined using an empirical formula. The inclusion of Magnus lift is significant because spherical particles spin just before dislodging downstream from their original position due to the differential hydrodynamic force along the vertical. The experimental data of sediment threshold are used to calibrate the model making the lift coefficient as a free parameter. The dependency of normalized threshold shear stress on particle parameter for various angles of repose and stream-wise bed slopes is presented graphically. The results obtained using the present model are compared with the curves proposed by different investigators and the experimental data of sediment (uniform and nonuniform) threshold for horizontal and stream-wise sloping beds.     

Seismic Behavior of CFT Column and Steel Pile Footings

In this study, two column and pile-footing models consisting of concrete-filled steel tube (CFT) columns, reinforced concrete footings, and steel H-piles were designed and constructed at approximately one-fifth scale. The experimental differences between the two models were in the design details of the CFT column-to-footing connections. One connection consisted of welded studs, and the other used a base plate and stiffeners. The two models were tested in a vertical cantilever condition with cyclic horizontal forces and a constant axial load applied to the top of the column. The model footings were supported on 16 model steel H-piles simulating the pile foundation. Under imposed horizontal displacement, the two models with different CFT-to-pile-cap connection details demonstrated satisfactory cyclic behavior, with the development of full plastic hinges at the bottom of the columns. Strut-and-tie modeling analysis was carried out to show the force-resisting mechanism in the reinforced concrete footing. The study also validated a new design detail for the anchorage of steel H-piles to pile caps.     

Effect of silane coupling agent on vulcanization,network structure,polymer-filler interaction,physical properties and failure mode of mica-filled styrene-butadiene rubber

Physical properties of composites from mica and styrene-butadiene rubber (SBR) have been studied with special reference to the effect of silane coupling agent (A-174) in the compound. Tensile and tear properties increase with the addition of mica. The increase of tensile properties in more pronounced in the case of silane-treated mica. Silane treatment also raises the volume fraction of rubber in solvent-swollen rubber vulcanizate. Attempts have been made to correlate the changes in properties with the network structure of rubber. In order to understand the mechanism of failure, tensile fracture surfaces have been examined by scanning electron microscopy (SEM). The fractographs have been correlated with the strength and type of failure of these composites. The observed values of viscosity (rheometric) correspond to the calculated values from existing theory based on the hydrodynamic model of dispersed particles in a fluid medium.     

A study of magneto-thermoelastic problems with thermal relaxation and heat sources in a three-dimensional infinite rotating elastic medium

This paper is concerned with a study of magneto-thermoelastic problems with thermal relaxation and heat sources in a three-dimensional infinite rotating elastic medium. The medium under consideration is assumed to be homogeneous, orthotropic, electrically as well as thermally conducting. The fundamental equations of the three-dimensional problem of generalized thermoelasticity with one relaxation parameter including heat source in an infinite rotating elastic medium under the influence of magnetic field are obtained as a vector-matrix differential equation form in the Laplace–Fourier transform domain which is then solved by the eigenvalue approach. A closed form solution of the problem is derived in the Laplace–Fourier domain. Finally, the inversion of the transform solution is obtained numerically in the space–time domain. Results of this paper presented graphically and then compared with previous results available in the literature. Two short appendices are included in this paper in order to make the work self-contained.     

Mutual phase stabilization of aluminium phosphate and titania in AlPO4-TiO2 binary system

Crystallization behaviour of amorphous aluminium phosphate (AlPO₄) and titania (TiO₂) in a mixed system of the two (5:1) has been reviewed in the light of our recent results. The polymorphous aluminium phosphate in such a binary system grows exclusively in a single phase over a temperature range 500–1150°C. The phase is reported to have a tridymite-like structure belonging to orthorhombic system with cell parametersa=9·638±0·0019,b=8·664±0·0017 andc=18·280±0036Å. Titania in the system preferentially retains its anatase phase morphology up to a temperature (950°C) well beyond its normal anatase → rutile transformation temperature showing a phenomenon of stabilization of this phase in such mixture. An interfacial reaction mechanism that can explain the observed phenomenon of mutual phase stabilization has been discussed and implications of this result towards the use of such technique for stabilization of various polymorphous compounds in a single phase has been pointed out.     

Deposition of yttria-stabilized zirconia buffer layer on Si and its suitability for Y-Ba-Cu-O thin films

The deposition of yttria-stabilized zirconia (YSZ) as buffer layer on (100) silicon has been studied by rf sputtering with a view to subsequently preparing superconducting films of YBa₂Cu₃O _x on it. As-deposited films were found to be (100) oriented. The thermal mismatch and reaction between Si and YSZ at high temperatures were found to give rise to cracks in the films. Grain growth of buffer layer on annealing helped in the formation of superconducting phase.