Autonomous multielectrode system for monitoring the interactions of isoflavonoids with lung cancer cells

The cytotoxic effect of isoflavonoids in the development of different forms of cancer has been reported by epidemiological and dietary studies. Consequently, there is a search for an accurate and reliable method for monitoring the interactions of these chemicals with cancerous cells. We have developed and optimized a fully autonomous electrochemical biosensor for studying the role of isoflavonoids on A549 lung adenocarcinoma cell line. This advanced biosensor uses a prototype 96-electrode (DOX-96) well-type device that allows the measurement of cell respiratory activity via the consumption of dissolved oxygen. The system provides a continuous, real-time monitoring of cell activity upon exposure to naturally occurring polyphenols, specifically resveratrol, genistein, and quercetin. The system is equipped with a multipotentiostat, a 96-electrode well for measurements and cell culturing with 3 disposable electrodes fitted into each well. A comparison with classical "cell culture" techniques indicates that the biosensor provides real-time measurement with no added reagents. A detection limit of 1 x 10(4) was recorded versus 200 and 6 x 10(3) cells/well for MTT and fluorescence assays, respectively. This method was optimized with respect to cell stability, reproducibility, applied potential, cell density per well, volume/composition of cell culture medium per well, and incubation. Others include total measuring time, temperature, and sterilization procedure. This study represents a basic research tool that may allow researchers to study the type, level, and specific influence of isoflavonoids on cells.     

Integrating waveguide biosensor

A capillary biosensor is demonstrated which uses the waveguiding properties of the capillary to integrate the signal over an increased surface area without simultaneously increasing the background noise from the detector. This biosensor achieves limits of detection of 30-50 pg/mL in immunoassays using a diode laser for excitation and a PMT for detection. This is approximately 2 orders of magnitude greater sensitivity than was achieved using the same immunoassay reagents in a fiber optic biosensor or a planar array biosensor. Two different approaches to using the capillaries as immunosensors are described, either of which could be adapted for multianalyte sensing.     

Propagation of acceleration waves in micropolar elastic solids

The propagation and growth of acceleration waves of arbitrary form propagating into a deformed micropolar elastic solid are investigated. The speeds of propagation are obtained for isotropic micropolar elastic materials and the growth equation is established. The growth equation of acceleration wave is integrated in the case of principle waves for isotropic materials and the decay conditions are examined for both macro- and micro-amplitudes.     

Influence of dietary protein sources on the amino acid profiles available for digestion and metabolism in lactating cows

Six lactating Holstein cows, fitted with T-type cannulas in the proximal duodenum, were used in a replicated 3 x 3 Latin square design to determine influence of supplemental protein on amino acid profiles of duodenal chyme and plasma. Protein sources were blood meal, corn gluten meal, and cottonseed meal, which furnished approximately 46% of the total protein in corn-grain corn silage diets. Markers were 15N to estimate rumen bacteria and chromic oxide to estimate nutrient flow. Dry matter intake was lowest on blood meal. Duodenal flow of N exceeded N intake 23% on blood meal and corn gluten meal. Percentages of organic matter and protein digested in the rumen were 56.5, 41.8; 61.2, 53.4; and 50.6, 56.2 for the respective diets. Variation in patterns of amino acids flowing to the duodenum, but not in coccygeal blood, closely reflected dietary differences with six of eight essential amino acids highest for the same treatment in both diet and duodenal chyme. Essential amino acids in least abundance for milk production, measured by mammary extraction coefficients, differed among diets. We conclude that supplemental protein source influences greatly the quantity and pattern of amino acids available for digestion in lactating dairy cows.     

DSP techniques for implementation of perfectly matched layer fortruncating FDTD domains

A new algorithm for implementing the perfectly matched layer (PML) using digital signal processing (DSP) is presented for truncating finite difference time-domain (FDTD) domains. The algorithm is based on incorporating digital filtering techniques into the PML formulation. A simple, unsplit-field and material independent PML formulation is achieved     

Utilization of Discretization method on the diagnosis of optic nerve disease

The optic nerve disease is an important disease that appears commonly in public. In this paper, we propose a hybrid diagnostic system based on discretization (quantization) method and classification algorithms including C4.5 decision tree classifier, artificial neural network (ANN), and least square support vector machine (LSSVM) to diagnose the optic nerve disease from Visual Evoked Potential (VEP) signals with discrete values. The aim of this paper is to investigate the effect of Discretization method on the classification of optic nerve disease. Since the VEP signals are non-linearly-separable, low classification accuracy can be obtained by classifier algorithms. In order to overcome this problem, we have used the Discretization method as data pre-processing. The proposed method consists of two phases: (i) quantization of VEP signals using Discretization method, and (ii) diagnosis of discretized VEP signals using classification algorithms including C4.5 decision tree classifier, ANN, and LSSVM. The classification accuracies obtained by these hybrid methods (combination of C4.5 decision tree classifier-quantization method, combination of ANN-quantization method, and combination of LSSVM-quantization method) with and without quantization strategy are 84.6-96.92%, 94.20-96.76%, and 73.44-100%, respectively. As can be seen from these results, the best model used to classify the optic nerve disease from VEP signals is obtained for the combination of LSSVM classifier and quantization strategy. The obtained results denote that the proposed method can make an effective interpretation and point out the ability of design of a new intelligent assistance diagnosis system.     

Q-switched pulse generation in a bidirectionally pumped EDFL utilizing Lu2O3 as saturable absorber

In this paper, we have successfully demonstrated a Q-switched pulse generation utilizing lutetium oxide (Lu2O3) thin film based saturable absorber (SA) in all-fiber erbium-doped fiber laser (EDFL) cavity with a bidirectional pumping. The Lu2O3 powder is mixed with isopropyl alcohol (IPA) solution before we add polyvinyl alcohol (PVA) as our host polymer to make the Lu2O3 into a thin film. By inserting the Lu2O3-PVA thin film into a bidirectional pumped EDFL cavity, a stable Q-switched pulse is realized with repetition rate in a range of rose from 43.67 kHz to 57.74 kHz whereas the pulse width decreased from 14.48 µs to 11.20 µs. This result indicates that the Lu2O3 can be implemented as an SA device in an EDFL as it owns a linear absorption of around 3 dB at 1 567 nm.     

Detection of femoral artery occlusion from spectral density of Doppler signals using the artificial neural network

This research is concentrated on the diagnosis of occlusion disease through the analysis of femoral artery Doppler signals with the help of Artificial Neural Network (ANN). Doppler femoral artery signals belong to occlusion patient and healthy subjects were recorded. Afterwards, power spectral densities (PSD) of these signals were obtained using Welch method and Autoregressive (AR) modeling. Multilayer feed forward ANN trained with a Levenberg Marquart (LM) backpropagation algorithm was implemented to these PSD. The designed classification structure has about 98% sensitivity, 97–100% specifity and correct classification is calculated to be 98–99% (for AR modeling and Welch method respectively). The end results are classified as healthy and diseased. Testing results were found to be compliant with the expected results that are derived from the physician's direct diagnosis. The end benefit would be to assist the physician to make the final decision without hesitation.     

Misalignment correction for optical interconnects using vertical cavity semiconductor optical amplifiers

In board-to-board optical interconnects, the misalignment between the board and the backplane connections can cause both optical loss and interchannel cross talk. A vertical cavity semiconductor optical amplifier (VCSOA) is proposed to correct optical misalignment in an optical connector between the board and the backplane. Angular or lateral misalignment can be corrected with the designed module. The correction ability is determined by the acceptance angle of the VCSOA, which was characterized to be 9.4 degrees full angle at a 3 dB gain drop for a 30 microW optical signal at 1 GHz. The lateral misalignment correction ability is 0.16f, where f is the focal length of the mini lens to converge the input light onto the VCSOA.