During the last decade, saliva has emerged as a potentially ideal diagnostic biofluid for noninvasive testing. In this paper, we present an automated, integrated platform useable by minimally trained personnel in the field for the diagnosis of respiratory diseases using human saliva as a sample specimen. In this platform, a saliva sample is loaded onto a disposable microfluidic chip containing all the necessary reagents and components required for saliva analysis. The chip is then inserted into the automated analyzer, the SDReader, where multiple potential protein biomarkers for respiratory diseases are measured simultaneously using a microsphere-based array via fluorescence sandwich immunoassays. The results are read optically, and the images are analyzed by a custom-designed algorithm. The fully automated assay requires as little as 10 μL of saliva sample, and the results are reported in 70 min. The performance of the platform was characterized by testing protein standard solutions, and the results were comparable to those from the 3.5-h lab bench assay that we have previously reported. The device was also deployed in two clinical environments where 273 human saliva samples collected from different subjects were successfully tested, demonstrating the device’s potential to assist clinicians with the diagnosis of respiratory diseases by providing timely protein biomarker profiling information. This platform, which combines non-invasive sample collection and fully automated analysis, can also be utilized in point-of-care diagnostics.

This paper describes a novel method for fabricating and sealing high-density arrays of femtoliter reaction chambers. We chemically etch one end of a 2.3 mm diameter glass optical fiber bundle to create an array of microwells. We then use a contact printing method to selectively modify the surface of the material between microwells with a hydrophobic silane. This modification makes it possible to fill the wells with aqueous solution and then seal them with a droplet of oil, forming an array of isolated reaction chambers. Individual β-galactosidase molecules trapped in these reaction chambers convert a substrate into a fluorescent product that can be readily detected because a high local concentration of product is achieved. This binary readout can be used for ultra-sensitive measurements of enzyme concentration. We observed that the percentage of wells showing enzyme activity was linearly dependent on the concentration of soluble β-galactosidase in the picomolar range. A similar response was also observed for streptavidin-β-galactosidase captured by biotinylated beads. These arrays are also suitable for performing single-molecule kinetics studies on hundreds to thousands of enzyme molecules simultaneously. We observed a broad distribution of catalytic rates for individual β-galactosidase molecules trapped in the microwells, in agreement with previous studies using similar arrays that were mechanically sealed. We have further demonstrated that this femtoliter fiber-optic array can be integrated into a PDMS microfluidic channel system and sealed with oil on-chip, creating an easy to use and high-throughput device for single-molecule analysis.

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As one of the very few countries using coal as its dominant energy resources, China has the coal production exceeding one thirds of in the world, added to it are the problems of environmental damages and soil resource destructions result from the solid waste, such as mining waste discharged in the process of coal production and fly ash deserted from the electric power plant etc. In this paper, the mineral ingredient of waste and fly ash was tested by X-ray Diffraction. Meanwhile, the deformation characteristics of the backfilling bodies with different waste and fly ash mixture ratio was tested by MTS815.02 electro-hydraulic servo rock mechanical test system, the optimal mixture ratio of waste and fly ash was 1:0.3, and it proposes that the backfilling body should be firstly tamped after being backfilled into the goaf. Moreover, technological framework for backfilling technology of substituting waste and fly ash for coal underground was expatiated, and the system layout of substituting waste and fly ash for coal was introduced systematically. Ultimately, the engineering application results witnessed the solution for the problems of environmental damages and soil resource destructions result from the waste and fly ash, based on the effective control of the strata and ground, and the environmental benefits and economic benefits with high production and recovery.