Distribution of IgG subclasses in antimonial unresponsive Indian kala-azar patients

BACKGROUND: Interleukin 10 (IL-10) decreases the severity of experimental acute pancreatitis. The role of endogenous IL-10 in modulating the course of pancreatitis is currently unknown. AIMS: To examine the systemic release of IL-10 and its messenger RNA production in the pancrease, liver, and lungs and analyse the effects of IL-10 neutralisation in caerulein induced acute pancreatitis in mice. METHODS: Acute necrotising pancreatitis was induced by intraperitoneal caerulein. Serum levels of IL-10 and tumour necrosis factor (TNF), and tissue IL-10 and TNF-alpha gene expression were assessed. After injecting control antibody or after blocking the activity of endogenous IL-10 by a specific monoclonal antibody, the severity of acute pancreatitis was assessed in terms of serum enzyme release, histological changes, and systemic and tissue TNF production. RESULTS: In control conditions, serum IL-10 levels increased and correlated with the course of pancreatitis, with a maximal value eight hours after induction. Both IL-10 and TNF-alpha messengers showed a similar course, and were identified in the pancreas, liver, and lungs. Neutralisation of endogenous IL-10 significantly increased the severity of pancreatitis and associated lung injury as well as serum TNF protein levels (+75%) and pancreatic, pulmonary, and hepatic TNF messenger expression (+33%, +29%, +43%, respectively). CONCLUSIONS: In this non-lethal model, systemic release of IL-10 correlates with the course of acute pancreatitis. This anti-inflammatory response parallels the release of TNF and both cytokines are produced multisystemically. Endogenous IL-10 controls TNF-alpha production and plays a protective role in the local and systemic consequences of the disease.     

ECG coding by wavelet-based linear prediction

Presents a novel coding scheme for the electrocardiogram (ECG). Following beat delineation, the periods of the beats are normalized by multirate processing. After amplitude normalization, a discrete wavelet transform is applied to each beat. Due to the period and amplitude normalization, the wavelet transform coefficients bear a high correlation across beats at identical locations. To increase the compression ratio, the residual sequence obtained after linear prediction of the significant wavelet coefficients is transmitted to the decoder. The difference between the actual period and the mean beat period, and that between the actual scale factor and the average amplitude scale factor are also transmitted for each beat. At the decoder, the inverse wavelet transform is computed from the reconstructed wavelet transform coefficients. The original amplitude and period of each beat are then recovered. The approximation achieved, at an average rate of 180 b/s, is of high quality. The authors have evaluated the normalized maximum amplitude error and its position in each cycle, in addition to the normalized root mean square error. The significant feature of the proposed technique is that, while the error is nearly uniform throughout the cycle, the diagnostically crucial QRS region is kept free of maximal reconstruction error     

Modified technique of using conventional slider boat for liquid phase epitaxy of silicon for solar cell application

Epitaxial layers of silicon are grown on single crystal Si- substrate from a solution of silicon in indium using conventional graphite slider boat technique. The important problems of natural convection due to lower density of silicon compared to indium,poor wetting of substrate due to high angle of contact of indium solution on silicon substrate resulting in poor nucleation, melt removal from the growth substrate and saturation wafer associated with LPE in this technique are practically eliminated using sandwich method with simple modifications of the boat and the method of growth. Some experimental studies on the effect of different surface preparations of growth substrate are also reported. Growth results are shown and discussed. Further, improvization of slider boat to facilitate better study of growth parameters is suggested in the line of modification already carried out.     

Studies on phospholipids of different mutants of Salmonella minnesota

Lipid composition of the cells of smooth (S form) and core-defective rough mutants (Ra, Rb & Re) of Salmonella minnesota has been studied. The readily-extractable lipids (RELs), acid-extractable lipids, and polar and nonpolar phospholipids have been analysed. Fatty acid composition of the different fractions containing phospholipids and other neutral lipids have been determined by GLC and GC-MS techniques. Phosphatidyl glycerol (PG), phosphatidylethanolamine (PE) and diphosphatidyl glycerol (DPG) were the major phospholipids present in all the strains. The major saturated fatty acid found was C16:0, and unsaturated fatty acids were, C16:1 and C18:1. Cyclopropane fatty acids, C17cy and C19cy, were also present in small amounts. Increased amounts of REL and unsaturated fatty acids were found in the mutants compared with the smooth strain. The amount of PG and PE decreased and DPG increased in the mutant strains.     

Influence of surface texturization on the light trapping andspectral response of silicon solar cells

A quantitative model that explains the spectral response, internal quantum efficiency, total short-circuit current, open-circuit voltage, and efficiency of high-efficiency solar cells with textured front surface and Lambertian back-surface reflectors is presented. A comparison of the textured cell characteristics is made with those of planar cells, and the separate roles of the front surface reflection coefficient and internal quantum efficiency in enhancing the short-circuit current have been investigated. It is shown that, in the case of large diffusion lengths, almost all the contribution to the increase of spectral response on texturization is due to the reduced reflection coefficient whereas, for small diffusion lengths, there is a significant increase in internal quantum efficiency on texturization, especially in the region of higher wavelengths. However, there is a small decrease in open-circuit voltage for large diffusion lengths, whereas no significant change is observed for small diffusion lengths on texturization. Nevertheless, there is a net gain in power conversion efficiency which is larger for smaller diffusion lengths     

Electrical and chemical diagnostics of transformers insulation. B.Accelerated aged insulation samples

This paper describes the analysis of accelerated aged insulation samples to investigate the degradation processes observed in the insulation from aged power transformers. Short-term accelerated ageing experiments were performed on paper-wrapped insulated conductors and on pressboard samples. The condition of aged insulation samples was investigated by two relatively new diagnostic techniques: (a) measurements of interfacial polarization spectra by a DC method; and (b) measurements of molecular weight and its distribution by gel permeation chromatography (GPC). Several other electrical properties of the paper/pressboard samples were also studied. Possible correlations have been investigated among the different measured properties. The GPC results have been used to predict how power transformer insulation molecular weights change with temperature and time     

Mechanical behavior and microstructure characterization of sinter-forged SiC particle reinforced aluminum matrix composites

A novel, low-cost sinter-forging approach to processing particle reinforced metal matrix composites for high-performance applications was examined. The microstructure of the sinter-forged composites exhibited relatively uniform distribution of SiC particles, which appeared to be somewhat aligned perpendicular to the forging direction. The degree of alignment and interparticle bond strength was not as high as that observed for the extruded composite. The sinter-forged composite exhibited higher Young’s modulus and ultimate tensile strength than the extruded material, but lower strain-to-failure. The higher modulus and strength were attributed to the absence of any significant processing-induced particle fracture, while the lower strain-to-failure was caused by poorer matrix interparticle bonding compared to the extruded material. Fatigue behavior of sinter-forged composites was similar to that of the extruded material. Fe-rich inclusions were extremely detrimental to fatigue life. Cleaner processing, which eliminated the inclusions, enhanced the fatigue life of the sinter-forged composites to levels similar to that of the extruded material.     

Solid state reactions of cordierite precursor oxides and effect of CaO doping on the thermal expansion behaviour of cordierite honeycomb structures

The extruded cordierite honeycomb structure from a stoichiometric formulation of talc, kaolinite, and alumina was subjected to TGA-DSC, dilatometric and XRD investigations. The experimental observations were made to identify the phase transformation sequence in order to understand the solid state reactions involved in the cordierite formation. A maximum cordierite content of 90% was achieved for the samples sintered at 1693 K with a soaking time of 4 h, corresponding to a lowest coefficient of thermal expansion (CTE) of 0.74 × 10^–6/K (along the direction of extrusion) was observed. Attempts were made to establish correlations with cordierite content, processing temperature and CTE of the samples. A few mechanisms are proposed to explain our observations. Attempts are also made to rationalize the low CTE observed along the direction of extrusion on the basis of orientation of anisotropic cordierite crystals as revealed by the transverse I-ratio calculated from the XRD patterns. Effect of CaO doping on CTE of cordierite has been studied in the present work. It was observed that though there is an increase in bulk thermal expansion of cordierite honeycombs on CaO doping due to the absence of micro-cracks as reveled by thermal cycling hysteresis, axial anisotropy was found to be reduced significantly.     

Network Model for Rural Roadway Tolling with Pavement Deterioration and Repair

The objective of roadway tolling in rural areas is often tied to revenue generation for roadway maintenance. Thus, rural pricing models should directly incorporate a pavement deterioration and maintenance model. However, the interactions between these models are not simple, because tolls cause traffic diversion, which in turn affects deterioration rates and forecasted revenue. This article describes a rural pricing model which calculates diversion endogenously with a network assignment model. This model captures deterioration rates and pavement condition in the toll‐setter's objective function, maximizing long‐run net present value of the highway infrastructure. A novel deterioration model is used which is particularly suitable for computational efficiency. The resulting model is discontinuous and nondifferentiable, and involves solving a combinatorial knapsack problem as a subproblem. Thus, a simulated annealing‐based algorithm is presented to solve it, in the framework of a new solution method built upon partitioning the feasible region. A demonstration is made using a network representing the state of Wyoming (28 zones, 60 nodes, and 188 links). Sensitivity analyses reveal that although the locations for optimal tolling are relatively stable as demand changes, the revenue collected can vary substantially. Relatively simple models are used throughout for computational reasons, and future research should investigate strategies for incorporating more advanced pavement and network models.