Culture amplification in human colon adenocarcinoma cell line (CaCo-2) combined with an ELISA as a supplementary assay for accurate diagnosis of rotavirus

Culture amplification in colon adenocarcinoma cell line (CaCo-2) combined with enzyme immunoassay (Pathfinder ELISA) was developed as a supplementary tool for rotavirus diagnosis. One hundred and thirty stools in which results by polyacrylamide gel electrophoresis (PAGE) were in agreement with those obtained by ELISA were amplified in the CaCo-2 cell line. After the first passage 100% specimens were revealed as positive by ELISA. This result was confirmed by PAGE and direct electron microscopy (EM) which increased the rates of rotavirus detection up to 100% after the third and fifth cell passages, respectively. All of the amplified negative stools were confirmed as negative. Among discordant results, three of the eight specimens positive by ELISA but negative by PAGE were confirmed as true positive after the third cell passage. False positive ELISA results could be discarded when the samples were culture amplified and retested by the same ELISA. Using the CaCo-2 amplification-ELISA as supplementary assay, sensitivity and specificity were 1.000 and 0.953 for ELISA and 0.917 and 1.000 for PAGE, respectively. The combined CaCo-2 cell line amplification-immunoassay method proved to be suitable both to evaluate increase in sensitivity of newly developed rotavirus assays and for rotaviral amplification before antigen assays.     

Flow graph development method

The present paper demonstrates the use of graph theory to find the steady state behaviour of multi-state systems described by Markov models.Two applications are demonstrated and compared with results obtained by Laplace Transform technique. The agreement between the two techniques appears to be excellent.The developed method is also compared with another method which uses the graph theory to calculate the steady state probabilities.     

SPICE application in the study of the behaviour of multi-state systems described by Markov models

This paper shows the applicability of the SPICE circuit analysis computer program for studying the behaviour of multi-state desribed by Markov models. Two samples are considered and the results are compared with those obtained by the Laplace transform and the flow graph methods. Agreement between the three techniques is excellent.     

MATCHING OF SEPARATELY EXCITED DC MOTORS TO PHOTOVOLTAIC GENERATORS FOR MAXIMUM POWER OUTPUT

This paper addresses the matching of separately excited dc motors to photovoltaic generators (PVG) for maximum power output. The dc motor is used to drive a centrifugal water pump. A PVG is a nonlinear device having insolation dependent I–V (current–voltage) characteristic, and hence a natural mismatch exists between the motor loads and the PVG. Therefore, considering the high initial cost of PVG, it is of vital importance to develop an appropriate matching process, to utilize PVG efficiently. In this article a procedure is developed to express the field current of the motor directly in terms of the maximum power point current and voltage of the PVG. It is shown that by adjusting the field current according to the developed relation, the motor is forced to follow the maximum power trajectory of the PVG, i.e. the input power of the motor is always equal to the maximum output power of the PVG at any available solar insolation. The effect of temperature on the I–V characteristic of the PVG is neglected at this stage. Finally a general expression is proposed relating the optimum field current directly to the available insolation level, which may be used as base for best matching.     

The visuo-motor pathway in the local circuit of the rat superior colliculus

Intrinsic circuit of the superior colliculus (SC), in particular the pathway from the optic tract (OT) to neurons in the intermediate layer (SGI), was investigated by whole-cell patch-clamp recording in slice preparations obtained from 17- to 24-d-old rats. Stimulation of the OT induced monosynaptic EPSPs in neurons in the superficial gray layer (SGS) and the optic layer (SO), and disynaptic or polysynaptic EPSPs in a majority of SGI neurons. Stimulation of the SGS induced monosynaptic or oligosynaptic EPSPs in the SGI neurons. Both the monosynaptic EPSPs induced in the SGS/SO neurons by stimulation of the OT and those induced in the SGI neurons by stimulation of the SGS were mediated by AMPA- and NMDA-type glutamate receptors. Thus, we have clarified the existence of the glutamatergic excitatory pathway from the OT to the SGI neurons via SGS and SO neurons. The EPSPs in the SGI neurons induced by stimulation of the OT or SGS were remarkably enhanced by bicuculline, suggesting that the signal transmission in this pathway is under strong suppression by the GABAergic system.     

Stress intensity factor calculation for a modified round bend bar by 3-D finite element analysis

Stress intensity factors were calculated for a modified round bend bar (MRBB) using 3-D finite element analysis. The results were compared with published solutions for a rectangular and round bend bars. The stress intensity values for the MRBB are between those for the two other geometries as expected. The stress intensity solutions were non-dimensionalized utilizing limit solution for short and long cracks.     

Assessment of evolutionary algorithms in predicting non-deposition sediment transport

In this article, the densimetric Froude number of the flow is estimated using the parameters of volumetric sediment concentration (C_V), the relative depth of flow (d/R), dimensionless particle number (D_gr) and the overall sediment friction factor (λ_s). The particle swarm optimization (PSO) and imperialist competitive algorithms (ICA) were used to estimate the densimetric Froude number. To study the effects of sediment transport parameters on the densimetric Froude number, six different models are presented. The PSO algorithm with root mean square error (RMSE) = 0.014 and mean absolute percentage error (MAPE) = 5.1% present the results with a relatively good accuracy. The accuracy of the results presented for the selected model by the ICA algorithm is also in the form of RMSE = 0.007 and MAPE = 5.6%. Although both algorithms return good results in estimating the densimetric Froude number for the selected model, it should be mentioned that for all the six presented models ICA returns better results than PSO.     

Fault detection and location in gears by the smoothed instantaneous power spectrum distribution

Time–frequency methods are effective tools for analysing diagnostics signals and have been widely used to describe machine condition. This paper introduces a time–frequency distribution, called the smoothed instantaneous power spectrum (SIPS) distribution, and demonstrates its use in the detection and location of local tooth defects in gears. The SIPS distribution is derived from the frequency domain definition of the instantaneous power spectrum (IPS) distribution, but has the added advantage that provides a considerable reduction in the ringing effect of the IPS transform, which results in a smoother and clearer time–frequency representation. A simulated gear vibration signal is used to show the capabilities of the proposed method over the IPS distribution and spectrogram. Healthy and faulty vibration signals monitored from a gear test rig are analysed, the results of which show that a local gear tooth defect can clearly be detected by the SIPS distribution.     

Acid‐Based Surfactant‐Aided Dispersion of Multi‐Walled Carbon Nanotubes in Epoxy‐Based Nanocomposites

In this study, the dispersion of multi‐walled carbon nanotubes (MWCNTs) in epoxy was facilitated by an anionic surfactant, linear alkyl benzene sulfonic acid. Different types of composites were prepared using a fixed amount of MWCNTs (0.5 wt%), in absence of solvent/surfactant, in presence of solvent and solvent/surfactant. The composites were characterized using Fourier transform infrared spectrophotometer, thermogravimetric analyzer (TGA), differential scanning calorimeter (DSC), universal testing machine, pendulum impact system, X‐ray diffraction, and scanning electron microscope. The epoxy/MWCNTs nanocomposite exhibited significantly higher mechanical properties due to the better dispersion in the presence of the surfactant. The tensile strength and flexural strength were increased by 75% and 108%, respectively. The thermal, structural, and morphological analyses were also excellent as a result of the better dispersion. In addition, the solvent‐surfactant behavior was hypothesized for the epoxy/MWCNTs system. POLYM. ENG. SCI., 59:E80–E87, 2019. © 2018 Society of Plastics Engineers