Ameliorative effect of α‐tocopherol on monosodium glutamate‐induced cardiac histological alterations and oxidative stress

BACKGROUND: Chronic oral intake of high doses of monosodium glutamate (MSG) causes oxidative stress. Oxidative stress plays an important role in the development of cardiac dysfunction and injury. Supplementation with α‐tocopherol protects the body against oxidative stress and its related complications. This study was proposed to examine the protective effect of α‐tocopherol against MSG‐induced biochemical and histological alterations in blood and cardiac tissue of rats for a period of 180 days. RESULTS: Chronic oral administration of MSG (4 g kg^?1) caused oxidative stress that was manifested by significant increase (P < 0.05) in malondialdehyde, conjugated dienes and by the decrease in the activities of superoxide dismutase, catalase, reduced glutathione, glutathione peroxidase and glutathione S‐transferase in cardiac tissue. The significantly increased (P < 0.05) activities of aspartate transaminase, creatine phosphokinase and lactate dehydrogenase in serum suggested a cardiac functional disorder. Moreover, heart muscle fibers showed cloudy swelling, fiber separation and vascular congestion. Administration of α‐tocopherol (200 mg kg^?1) significantly (P < 0.05) attenuated the MSG‐induced biochemical alterations in serum and cardiac tissue. α‐Tocopherol also prevented the pathological changes in cardiac tissue when compared with the MSG‐treated group. CONCLUSION: Our findings suggest that α‐tocopherol may have a protective effect against MSG‐induced cardiotoxicity, possibly through its antioxidant activity. Copyright © 2012 Society of Chemical Industry     

Low-Cost Specification Based Testing of RF Amplifier Circuits using Oscillation Principles

In this paper, we propose a low-cost approach for testing GHz RF amplifiers. It is demonstrated for the first time that GHz RF amplifiers can be tested for their specifications using oscillation principles. In the test mode, the RF test signal is “self generated” by the amplifier with the help of additional external circuitry which forces the amplifier to oscillate (Barkhausen criterion) around its characteristic frequency. The RF sinusoidal output from the oscillating RF amplifier is down-converted to a lower frequency enabling low frequency test response analysis as well as increased sensitivity to parametric deviations. In addition to the detection of catastrophic failures, it is shown that multiple RF specifications (Gain, P1dB, and Noise Figure) can be predicted via analysis of the frequency of the down-converted response. To account for RF parasitics on the production floor, a calibration technique is proposed in the test-setup. Thus, the proposed method reduces test cost significantly by reducing the cost of test setup (by as much as 80%) and significantly reducing test time. The viability of the proposed test method is demonstrated both by simulation experiments and measurement.     

Multi-objective optimization and decision making approaches to cricket team selection

Selection of players for a sports team within a finite budget is a complex task which can be viewed as a constrained multi-objective optimization and a multiple criteria decision making problem. The task is specially challenging for the game of cricket where a team requires players who are efficient in multiple roles. In the formation of a good and successful cricket team, batting strength and bowling strength of a team are major factors affecting its performance and an optimum trade-off needs to be reached. We propose a novel gene representation scheme and a multi-objective approach using the NSGA-II algorithm to optimize the overall batting and bowling strength of a team with 11 players as variables. Fielding performance and a number of other cricketing criteria are also used in the optimization and decision-making process. Using the information from the trade-off front obtained, a multi-criteria decision making approach is then proposed for the final selection of team. Case studies using a set of players auctioned in Indian Premier League (IPL) 4th edition are illustrated and players’ current statistical data is used to define performance indicators. The proposed computational techniques are ready to be extended according to individualistic preferences of different franchises and league managers in order to form a preferred team within the budget constraints. It is also shown how such an analysis can help in dynamic auction environments, like selecting a team under player-by-player auction. The methodology is generic and can be easily extended to other sports like American football, baseball and other league games.     

Development of novel chitin/nanosilver composite scaffolds for wound dressing applications

Antibiotic resistance of microorganisms is one of the major problems faced in the field of wound care and management resulting in complications like infection and delayed wound healing. Currently a lot of research is focused on developing newer antimicrobials to treat wounds infected with antibiotic resistant microorganisms. Silver has been used as an antimicrobial agent for a long time in the form of metallic silver and silver sulfadiazine ointments. Recently silver nanoparticles have come up as a potent antimicrobial agent and are finding diverse medical applications ranging from silver based dressings to silver coated medical devices. Chitin is a natural biopolymer with properties like biocompatibility and biodegradability. It is widely used as a scaffold for tissue engineering applications. In this work, we developed and characterized novel chitin/nanosilver composite scaffolds for wound healing applications. The antibacterial, blood clotting and cytotoxicity of the prepared composite scaffolds were also studied. These chitin/nanosilver composite scaffolds were found to be bactericidal against S. aureus and E. coli and good blood clotting ability. These results suggested that these chitin/nanosilver composite scaffolds could be used for wound healing applications.     

Nanogold‐Loaded Sharp‐Edged Carbon Bullets as Plant‐Gene Carriers

The higher DNA delivery efficiency into plants by gold nanoparticles embedded in sharp carbonaceous carriers is demonstrated. These nanogold‐embedded carbon matrices are prepared by heat treatment of biogenic intracellular gold nanoparticles. The DNA‐delivery efficiency is tested on a model plant, Nicotiana tabacum, and is further extended to the monocot, Oryza sativa, and a hard dicot tree species, Leucaena leucocephala. These materials reveal good dispersion of the transport material, producing a greater number of GUS foci per unit area. The added advantages of the composite carrier are the lower plasmid and gold requirements. Plant‐cell damage with the carbon‐supported particles is very minimal and can be gauged from the increased plant regeneration and transformation efficiency compared with that of the commercial micrometer‐sized gold particles. This is ascribed to the sharp edges that the carbon supports possess, which lead to better piercing capabilities with minimum damage.     

Finite Element Simulation of Laser Welding of 904L Super Austenitic Stainless Steel

Experiments on Laser butt welding of 904L super austenitic stainless steel was conducted using diffusion cooled 3.5 kW slab CO₂ laser welding system. The weld geometries such as bead width and depth of penetration were measured. The laser welding process has also been simulated using ANSYS a Finite Element Analysis tool. The effect of laser power, welding speed and focal point position on the bead geometry was investigated. The experimental plan was developed based on the Taguchi technique. The comparison of the results of the simulation indicates that Finite Element Method (FEM) can predict the responses adequately within the limits of welding parameters being used. It is suggested that FEM can be used as a tool for predicting the bead geometry at low values of heat input on laser welding.     

An integrated software system for processing, analyzing, and classifying Raman spectra

Raman spectroscopy is a powerful technique for analyzing various substances, but a significant amount of processing is required to extract useful information from raw spectra. Many research groups develop custom software systems to process spectra, which leads to standard algorithms being repeatedly implemented and novel techniques being difficult to share. This paper presents an integrated software system that processes, analyzes, and classifies Raman spectra. The system is freely available (http://cares.wayne.edu/rp/), open, cross-platform, and extensible, enabling interested parties to utilize and contribute to a common implementation of Raman processing algorithms.A wide variety of useful features are included, such as noise filtering, automated background fluorescence subtraction, principal component analysis, linear discriminant analysis, artificial neural network classification, and support vector machine classification. The system supports customizable groupings of related spectra and is able to retrieve spectra using a searchable database. Everything is executed through a simple graphical user interface.The developed system was used to process two data sets containing different types of spectra. The results demonstrate that the system is capable of fast, accurate processing of Raman spectra. The open system will become even more powerful if other developers are willing to add new and improved features. In addition, it is intended that the freely available system will make Raman spectroscopy more accessible to all researchers and promote progress in the field.     

Investigation of flow characteristics in supersonic combustion ramjet combustor toward improvement of combustion efficiency

Supersonic combustion ramjet (scramjet) is a variant of ramjet in which the combustion takes place at supersonic velocity. The flow physics inside the scramjet combustor is quite complex due to the fact that the mixing and completion of the combustion take place in a short time, which is of the order of milliseconds. This study focuses on flow characteristics within the combustion chamber of the scramjet engine that is designed to improve energy efficiency by enhancing combustion efficiency. The effect on combustion performance and thereby the energy efficiency on using strut‐based flame stabilizer is evaluated at different positions. Reynolds averaged Navier‐Stokes equations are solved with the Shear Stress Transport k‐ω turbulence model. Single strut configuration is used to validate with the experimental data. Single strut is then compared with three‐strut configuration. In the three‐strut configuration, the location of the primary strut is kept constant, and the secondary struts are relocated in x and y directions. Combustion performance was evaluated for the cases of flow from primary strut only and through three struts. It was found that the placement of secondary strut in a three‐strut configuration plays a vital role in improving energy efficiency. A maximum of 33.86% improvement in combustion efficiency was observed in comparison to the single strut combustor. A reduction in unburned fuel was observed, making the system more energy efficient. If the struts are not placed optimally, the combustion performance of the combustor was observed to be lower than that of a single‐strut configuration. The shock reflection and expansion fans within the primary combustion zone and the secondary strut region enhance the combustion efficiency. The wall static pressure was observed to increase with the addition of secondary struts. For certain strut configurations, flow separation was seen on the combustor walls. If the secondary strut was placed close to the primary strut, combustion efficiency was found to enhance. It was seen that combustion efficiency was also enhanced for the cases of reacting flow from primary strut only. It could also help to increase fuel efficiency, as additional fuel is not supplied to the secondary strut, making the overall system energy efficient. As the secondary strut is introduced, total pressure loss also increases. It could also be noted that if the combustor length was increased, there could be further increased in combustion efficiency.