In this report, a simple and highly selective homogeneous sandwich immunoassay was developed for ultrasensitive detection of Staphylococcal Enterotoxin B (SEB) using Surface Enhanced Raman Scattering (SERS). The assay uses polyclonal-antibody functionalized magnetic gold nanorod particles as capture probes for SEB, which can be collected via a simple magnet. After separating SEB from the sample matrix, they are sandwiched by using binding-specific antibody-antigen pairs with the help of gold nanorod particles. Gold nanorod particles are bifunctional by design and contain self-assembled monolayers (SAMs) of a SERS tag molecule (5,5-dithiobis (2-nitrobenzoic acid), DTNB) and carboxylic functionalities of DTNB for coupling with a suitable antibody. The correlation between the SEB concentration and SERS signal was found to be linear within the range of 3 fM to 0.3 μM. The limit of detection for the assay was determined to be 768 aM (ca., 9250 SEB molecules per 20 μL sample volume). The gold heterogeneous assay system for SEB detection was also compared with the same SERS probes and gold-coated surfaces as capture substrates. The developed method was further evaluated for detecting SEB in artificially contaminated milk. Finally, the method was used for investigating the SEB specificity on bovine serum albumin (BSA) and avidin.
An inferential control methodology, that utilizes an artificial neural network (ANN) estimator for a model predictive controller (MPC), is developed for an industrial multicomponent distillation column. In the control of product compositions by a feedback control system, because of the difficulty of on-line measurements of compositions, temperature measurements can be utilized. The selection of the temperature measurement points for the inferential control is done by the help of singular value decomposition (SVD) analysis together with column dynamics information. A moving window ANN estimator is designed to estimate the product compositions from tray temperature measurements. The composition predictions are further corrected with the actual composition data in 30-min intervals. A multi input multi output (MIMO) MPC is used with the developed ANN estimator for the dual composition control of the column. The performance of the developed control system utilizing ANN estimator is tested considering set-point tracking and disturbance rejection performances for the unconstrained and constrained cases. It is observed that the controller utilizing ANN estimator is as good as the controller utilizing direct composition values.
The critical Reynolds number is calculated as a function of the duct aspect ratio for flow of Newtonian fluids in ducts of rectangular cross sections. A simplified procedure is also presented using an approximate velocity distribution.
Parylene C has been preferred in various microfluidic and packaging applications as a chemical barrier; therefore, its durability in chemicals is critical to maintain functionality of the devices. In this paper, we investigated solvent compatibility of Parylene C in a range of solvents with regard to swelling of it and the change in its surface roughness at room temperature. The results of Parylene C swelling were associated with solubility parameter, δ (cal/cm 3 ) 1/2 , which is predicted from the parameters of dispersion, polar, and hydrogen-bonding forces. Solvents that swelled Parylene C film layer mostly were benzene, chloroform, trichloroethylene, and toluene, while methanol, 2-propanol, ethylene glycol, and water did not cause any swelling. Subsequently, the adverse effects of diffusion of solvents through a Parylene C film layer were demonstrated by stripping of the encapsulated photoresist. In addition, a comparison was made between Parylene C and poly(dimethyl)siloxane (PDMS) considering the data of swelling ratios obtained from the experimental findings and the literature, respectively. Experimental findings showed that Parylene C is much more compatible to solvents than PDMS in high-throughput microfluidic and packaging applications. These results will be of great value to scientists for understanding compatibility of any selected solvent on Parylene C in the applications of micro devices.[2013-0113]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.