An intelligent model to predict the life condition of crude oil pipelines using artificial neural networks

Neural Computing and Applications - Inefficient scheduling of a pipeline system may lead to severe degradation and substantial economic losses. Earlier studies mostly focussed on corrosion and...     

Fabrication of BioFET linear array for detection of protein interactions

An extended-gate MOSFETs (metal–oxide-semiconductor field-effect transistors) based biosensing linear array has been fabricated for label-free protein interaction detection. The device was realized using a combination of very low leakage current MOSFET transistors and an external gate where the chemical reaction would take place. Peptide aptamers that recognize cyclin-dependent kinase (CDK), a protein cancer marker, were used as a biological test system. The test results showed a high sensitive in the detection of CDK.     

Studies on the Synthesis and Activity of Three Tripalladium Complexes Containing Planaramine Ligands

The present study deals with the synthesis, characterization and activity against human cancer cell lines: A2780, A2780^cisR and A2780^ZD0473R of three tripalladium complexes, MH3, MH4 and MH5, that each have two planaramine ligands bound to the central metal ion. Cellular uptake levels, extent of DNA binding, and nature of interaction with salmon sperm and pBR322 plasmid DNA were determined for each complex. Palladium compounds are much more reactive than their corresponding platinum derivatives, which makes them therapeutically inactive but toxic. However, the results of the present study suggest that significant antitumour activity can be introduced in palladium complexes by lessening their reactivity by the introduction of sterically hindered ligands such as 2‐hydroxypyridine, 3‐hydroxypyridine and 4‐hydroxypyridine. When bound to the central palladium ion, 4‐hydroxypyridine appears to be more activating than 2‐hydroxypyridine and 3‐hydroxypyridine, suggesting that noncovalent interactions, such as hydrogen bonding, may also be key determinants of antitumour activity in addition to the steric effect. While cisplatin binds with DNA to form intrastrand GG adducts that causes local bending of a DNA strand, these planaramine‐derived palladium complexes are expected to bind with DNA and form a number of long‐range interstrand GG adducts that would cause a global change in DNA conformation, provided the tripalladium cations in MH3, MH4 and MH5 persist under physiological conditions.     

A generalized film technique for the verification of vertex fields used in the treatment of brain tumors

With the availability of commercial three-dimensional (3D)-treatment planning systems, more and more treatment plans call for the use of noncoplanar conformal beams for the treatment of brain tumors. However, techniques for the verification of many noncoplaner beams, such as vertex fields which involve any combination of gantry, collimator, and table angles, do not exist. The purpose of this work is to report on the results of an algorithm and a technique that have been developed for the verification of noncoplanar vertex fields used in the treatment of brain tumors. This technique is applicable to any geometric orientation of the beam, i.e., a beam orientation that consists of any combination of gantry, table, and collimator rotations. The method consists of superimposing a central plane image of a correctly magnified vertex field on a lateral or oblique field port film. To achieve this, the 3D coordinates of the projection of the isocenter onto the film for lateral (or oblique) as well as the vertex fields are determined and then appropriately matched. Coordinate transformation equations have been developed that enable this matching precisely. A film holder has been designed such that a film cassette can be secured rigidly along the side rails of the treatment table. The technique for taking a patient treatment setup verification film consists of two steps. In the first step, the gantry, table, and collimator angles for the lateral (or oblique) field are set and the usual double exposures are made; the first exposure corresponds to that of the treatment portal with the isocenter clearly identified and the second one a larger radiation field so that the peripheral anatomy is visible on the film. In the next step, the gantry, table, and collimator angles are positioned for the vertex field and the table is moved laterally and vertically and the film longitudinally to a position that will enable precise matching of the isocenter on the film. A third exposure is then taken with the vertex portal. What is seen on the film is a superposition of a central plane image of the vertex field onto the image of the lateral or oblique field. This technique has been used on 60 patients treated with noncoplanar fields for brain tumors. In all of these cases, the coincidence of the projection of the isocenter for the lateral (or oblique) and the vertex fields was found to be within 3 mm.     

Modeling of fiber–polymer coupling for suspensions of mono‐modal fibers

The rheology of suspensions of fibers in polymer solutions is strongly dependent on fiber–fiber and fiber–polymer interactions. To model these interactions and their dependence on the flow and suspension properties, the steady shear viscosity of glass fibers in a polyethylene oxide polymer solution are measured for different fiber volume fractions and aspect‐ratios. The measurements are conducted for well characterized fiber samples that have a uniform and well defined aspect‐ratio and for moderate volume fractions. The results of the experimental study are used to correlate the polymer–fiber coupling factor and the fiber–fiber interaction coefficient using a mathematical model based on a modified FENE‐P (finitely extensible nonlinear elastic) constitutive equation. It was found that both parameters are strongly dependent on the characteristics of the suspension, but also depend on the flow shear rate that determines the degree of fiber orientation. In general, fiber–fiber and polymer–fiber interactions increase with both the aspect‐ratio and the volume fraction and are more important when the fibers are not fully oriented. POLYM. COMPOS., 27:82–91, 2006. © 2005 Society of Plastics Engineers