The use of urea carbon 14 in breath tests as diagnostic method for Helicobacter pylori infections

The Helicobacter Pylori has been indicated as a pathologic agent in the pathogenesis of antral gastritis, gastric and duodenal ulcers and probably in gastric cancer. Due to the high incidence of this infection in our place, we decided to look for a diagnostic method quick to perform, sensitive, reliable and no invasive. The breath test of 14C urea, based in the production of urea by the H. Pylori, represents this alternative. We have found, using does of 1 microCi, a high correlation with the diagnosis of H. Pylori by biopsies. We determined as negative less than 100 DPM, doubtful between 100 and 200 DPM and positive more than 200 DPM. The high pick of the curve keeps tight relation with the degree of infection. We checked this when we suppressed the H. Pylori with bismuth subsalicylate. The breath 14C Urea test showed high sensitivity (100%) and specificity (85.71%). We conclude that this breath test is an alternative way of diagnosing and follow up for H. Pylori infections. It is highly sensitive, reproducible and no invasive.     

On the strong discontinuity approach in finite deformation settings

Taking the strong discontinuity approach as a framework for modelling displacement discontinuities and strain localization phenomena, this work extends previous results in infinitesimal strain settings to finite deformation scenarios. By means of the strong discontinuity analysis, and taking isotropic damage models as target continuum (stress–strain) constitutive equation, projected discrete (tractions–displacement jumps) constitutive models are derived, together with the strong discontinuity conditions that restrict the stress states at the discontinuous regime. A variable bandwidth model, to automatically induce those strong discontinuity conditions, and a discontinuous bifurcation procedure, to determine the initiation and propagation of the discontinuity, are briefly sketched. The large strain counterpart of a non‐symmetric finite element with embedded discontinuities, frequently considered in the strong discontinuity approach for infinitesimal strains, is then presented. Finally, some numerical experiments display the theoretical issues, and emphasize the role of the large strain kinematics in the obtained results. Copyright © 2003 John Wiley & Sons, Ltd.     

Effect of warping-pretwist coupling on the natural vibration of torsionally clamped-pinned thin-walled open-profile bars

Exact natural frequencies are determined for the torsional vibration of pretwisted thin-walled open-profile bars having torsionally clamped and pinned end restraints. The equation of motion and boundary conditions are derived from a multifilament model of a pretwisted thin-walled bar undergoing warp deformation and a moderately large twist about the elastic axis. Closed-form torsional frequencies and mode shapes are derived from the linear terms of the resulting non-linear equations. As the length-to-leg ratio (L/b) and leg-to-thickness ratio (b/t) of typical open-profile bars are varied, the individual and collective effects of warping and pretwist on the non-dimensional torsional frequencies are demarcated. In addition, the closed-form solutions offered here reveal considerable destiffening of the torsional frequencies due to warping-pretwist coupling present in thin-walled bars having pretwisted, unsymmetrical, open-profiles and torsionally clamped and pinned end restraints. This coupling effect, which have been ignored in thin-walled bar vibration theories hitherto, is brought out by the Wagner effect and warping shear stresses acting on the profiles.     

The practitioner perspective on the modeling of pedagogy and practice

Abstract   The promotion of e-learning in policies internationally has led to questions about how best to employ technology in support of learning. A range of models has since been developed that attempts to relate pedagogy to technology. However, research into the effectiveness of such models in changing teaching practice is sparse, and work that compares these models to practitioners' own representations of their practice is absent. The study described here involved asking practitioners to model their own practice, and to compare these with a model developed by a government organization. Practitioners were adept at using existing models and repurposing them to suit their own context. Our research provided evidence of broad acceptance of the existing model with practitioners, but indicated that practitioners would take this tool and remodel it for their own contexts of learning to make it meaningful, relevant and useful to them.     

A biochemical microdevice with an integrated chemiluminescence detector

By taking advantage of both the semiconductor properties and the advanced micromachining possibilities of silicon, integration of back-side photodiodes with a microfluidic channel network on a single substrate is accomplished. The resulting microsystem has all fluidic and electrical connections on one side of the chip. Hermetic sealing by anodic bonding is greatly facilitated by the simple topography on the front-side of the chip. To test the chemical functionality and performance of the device a chemiluminescence-based detection scheme is implemented. The introduction and control of the necessary chemical solutions is achieved using a flow injection analysis approach. Hydrogen peroxide is used as a model compound; injected plugs with concentrations in the range of 100 μM to 1 mM are successfully detected.     

ICT and operations outsourcing in banking

Outsourcing of ICT (Information and communications technology) and Operations services has reappeared on the agenda of top management in European banking. As a contribution to this important topic, McKinsey & Company has carried out a comprehensive survey, based primarily on 70 interviews with executives of banks and providers. Key topics analyzed are: the relevance of outsourcing to address current challenges in banking; the value created by outsourcing and the barriers to its successful implementation; the degree of viability of outsourcing across specific services and functions; and likely developments in the outsourcing market. In addition, industry best practices have been collected and synthesized.     

Thermal properties of fats and oils

Summary 1. The heat content of a quickly chilled sample, and that of a slowly chilled and tempered sample, of almost completely hydrogenated cottonseed oil, has been measured over a temperature range within which there is in each case complete transformation of the oil from a solid to a liquid form. 2. Heat capacity data have been calculated for the liquid oil and for the quickly chilled and the tempered solid oil. Equations expressing the changes in heat capacity with temperature have been derived. A correlation of the heat capacity data on highly hydrogenated cottonseed oil and similar data previously obtained on unhydrogenated cottonseed oil, and on partially hydrogenated oil, in both liquid and solid states, is presented. 3. The heat of fusion calculated for the quickly chilled and for the tempered solid oil is given. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.