Volume 2 Issue 4

Authors: Ronald K. June; John P. Cunningham; David P. Fyhrie

Abstract: The stretched exponential function has many applications in modeling numerous types of experimental relaxation data. However, problems arise when using standard algorithms to fit this function: we have observed that different initializations result in distinct fitted parameters. To avoid this problem, we developed a novel algorithm for fitting the stretched exponential model to relaxation data. This method is advantageous both because it requires only a single adjustable parameter and because it does not require initialization in the solution space. We tested this method on simulated data and experimental stress-relaxation data from bone and cartilage and found favorable results compared to a commonly-used Quasi-Newton method. For the simulated data, strong correlations were found between the simulated and fitted parameters suggesting that this method can accurately determine stretched exponential parameters. When this method was tested on experimental data, high quality fits were observed for both bone and cartilage stress-relaxation data that were significantly better than those determined with the Quasi-Newton algorithm.

Keywords: Cartilage Biomechanics; Osteoarthritis; Curvefitting; Optimization; Polymer Dynamics

Doi:10.5963/BER0204001

Authors: Mohamed M. Elseweidy; Sahar E. Elswefy; Mohamed Shawky

Abstract: Background: Renal injury may develop in uncontrolled diabetic manifestations, mostly attributed to increased oxidative stress and release of pro-inflammatory mediators and finally leading to diabetic complications. Methods: Curcumenoids which have anti-oxidant and anti-inflammatory properties were tested in alloxan-induced hyperglycemia in rats on oxidative stress, gene expression of tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1), in relation to microalbuminuria and renal function. Results: We found that the onset of microalbuminuria preceded the increase in serum glucose after alloxan administration. Gene expression of TNF-α and TGF-β1 showed a gradual increase after one and two weeks of alloxan administration as compared to the normal group. Curcumenoids administration decreased gene expression of TNF-α and TGF-β1 in kidneys, serum-glucose, fructosamine, urea, creatinine, C-reactive protein, malondialdehyde, urinary microalbumin and total protein. Histological examination of kidney tissues showed significant improvement in Curcumenoids-treated rats as compared to untreated diabetic rats. Conclusions: Curcumenoids modulated renal injury of alloxan-induced diabetic rats as revealed by observed biochemical data. This may refer to it as therapeutic candidate for treatment of diabetic renal injury and clinical trials are mostly requested.

Keywords: Nephropathy; Curcumenoids; Malondialdehyde; Tumor Necrosis Factor-alpha; Transforming Growth Factor-beta1; Microalbuminuria

Doi:10.5963/BER0204003

Authors: E. Leonora; N. Randazzo; F. Romano; G. V. Russo; M. Russo; V. Sipala; C. Stancampiano; V. Giordano; G. A. P. Cirrone; S. Aiello; C. Pugliatti; D. Lo Presti; D. L. Bonanno; F. Longhitano

Abstract: This paper presents the design flow of a detector for tracking charged particles together with the characterization techniques developed to extract the main design specifications. The goals for the final detector are to achieve real-time imaging, a large detection area and a high spatial resolution particularly suitable for medical imaging applications. The main concepts have been patented by the INFN. This paper describes the prototype tracker, which has a 20x20 cm2 sensitive area consisting of two crossed ribbons of 500 µm square scintillating fibers. The track position information is real-time extracted in an innovative way, using a reduced number of read-out channels to obtain a very large detection area but with moderate costs and complexity. The performance of the tracker has been investigated using ß sources, cosmic rays, and a 62 MeV proton beam.

Keywords: Scintillating Fiber; Tracking Detector; Real-time

Doi:10.5963/BER0204002