71 research outputs found
Automated on-disc total RNA extraction from whole blood towards point-of-care for early-stage diagnostics
We present a novel integrated, centrifugo-pneumatic
micro-homogenizer (“μHomogenizer”) for automated
sample preparation and total RNA extraction from whole
blood. Using a Trizol based protocol, this novel
μHomogenizer efficiently lyses whole blood spiked with
E. coli, retains the organic-mixed fraction and yields the
aqueous phase with the total RNA content. By the
interplay of microfluidic design and a protocol of
rotational frequencies, we concatenate (and parallelize) a
sequence of five subsequent liquid handling operations
that complete in less than 10 minutes. A comparison of
the total nucleotide content yields similar performance as
conventional, essentially manual off-disc sample
preparation methods
Rotational-pulse actuated dissolvable-film valves for automated purification of total RNA from E. Coli
In this work we report for the first time on a repertoire of valving technologies which are combined to enable automated purification of total RNA from cell homogenate. Process control is implemented us-ing rotational-pulse actuated dissolvable-film (DF) valves; where the order of valve actuation is deter-mined by the disc architecture while the timing of valve actuation is governed by pulses in the spin rate. Selective liquid routing is enabled by combining a heavy, inert and immiscible liquid plug with a DF. The combination of these technologies enables bead-based extraction of amplifiable RNA, with a yield comparable to gold-standard bench-top protocols
Airborne Fungal Spore Review, New Advances and Automatisation
Fungal spores make up a significant portion of Primary Biological Aerosol Particles (PBAPs) with large quantities of such particles noted in the air. Fungal particles are of interest because of their potential to affect the health of both plants and humans. They are omnipresent in the atmosphere year-round, with concentrations varying due to meteorological parameters and location. Equally, differences between indoor and outdoor fungal spore concentrations and dispersal play an important role in occupational health. This review attempts to summarise the different spore sampling methods, identify the most important spore types in terms of negative effects on crops and the public, the factors affecting their growth/dispersal, and different methods of predicting fungal spore concentrations currently in use
Development of an on-disc isothermal in vitro amplification and detection of bacterial RNA
This document is the Accepted Manuscript version, made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License CC BY NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/). The final, published version is available online at doi: https://doi.org/10.1016/j.snb.2016.08.018. Published by Elsevier B. V.We present a centrifugal microfluidic “Lab-on-a-Disc” (LoaD) system capable of implementing nucleic acid in vitro amplification using non-contact heating and fluorescence detection. The system functionality is verified by implementing a Nucleic Acid Sequence Based Amplification (NASBA) reaction, targeting the tmRNA transcript of Haemophilus influenzae. The NASBA assay incorporates fluorescent molecular beacon probes reporting target tmRNA amplification for endpoint detection. The system implements non-contact IR heating to heat the NASBA reaction to the required target temperatures during denaturation and amplification steps. The LoaD control system facilitates spin speed and chamber positioning for heating and fluorescence detection. The LoaD alignment system uses magnetic fields to locate and lock the chamber in the required position (heating or detection). The NASBA assay was implemented on the system using Haemophilus influenzae tmRNA over the range 102–104 cell equivalent (CE) units. For comparison, identical qNASBA assays were implemented on a Roche LightCycler 2.0 over this concentration range.Peer reviewe
Ensemble-Empirical-Mode-Decomposition based micro-Doppler signal separation and classification
The target echo signals obtained by Synthetic Aperture Radar (SAR) and Ground Moving Target Indicator (GMTI platforms are mainly composed of two parts, the micro-Doppler signal and the target body part signal. The wheeled vehicle and the track vehicle are classified according to the different character of their micro-Doppler signal. In order to overcome the mode mixing problem in Empirical Mode Decomposition (EMD), Ensemble Empirical Mode Decomposition (EEMD) is employed to decompose the original signal into a number of Intrinsic Mode Functions (IMF). The correlation analysis is then carried out to select IMFs which have a relatively high correlation with the micro-Doppler signal. Thereafter, four discriminative features are extracted and Support Vector Machine (SVM) classifier is applied for classification. The experimental results show that the features extracted after EEMD decomposition are effective, with up 90% success rate for classification using one feature. In addition, these four features are complementary in different target velocity and azimuth angles
Solvent-selective routing for centrifugally automated solid-phase purification of RNA
The final publication is available at Springer via https://doi.org/10.1007/s10404-014-1477-9.We present a disc-based module for rotationally controlled solid-phase purification of RNA from cell lysate. To this end, multi-stage routing of a sequence of aqueous and organic liquids into designated waste and elution reservoirs is implemented by a network of strategically placed, solvent-selective composite valves. Using a bead-based stationary phase at the entrance of the router, we show that total RNA is purified with high integrity from cultured MCF7 and T47D cell lines, human leucocytes and Haemophilus influenzae cell lysates. Furthermore, we demonstrate the broad applicability of the device through the in vitro amplification of RNA purified on-disc using RT-PCR and NASBA. Our novel router will be at the pivot of a forthcoming, fully integrated and automated sample preparation system for RNA-based analysis.Peer reviewe
Commercial design of four indirect-fired fluidized bed gasifer systems
This thesis deals with the design and cost analysis of four scaled up gasification plants. Reactor outputs range from 10 to 40 million Btu/hr (heating value of gas). Scale-up design parameters are based on data obtained from a 20 inch indirectly heated steam fluidized bed gasifier. This produces a medium Btu gas (450 Btu/ft3). The gas may be burnt on site or used as a chemical feedstock.
The plant designs consider reactor sizes, steam plant dimensions, specifications for feedhoppers, cyclones, conveying equipment, internal firetube heat exchangers, and drying plants.
The economic analysis deals with the cost of the above, and calculates the costs of producing 1 million Btu of the gas for each reactor size, thus allowing a comparison to be made with the current cost of natural gas, or gas produced by some other process.
Results of the analysis indicate a price of 13.30/million Btu for the 40x106 Btu/hr plant, which are in excess of $6/million Btu which is the approximate cost of natural gas per million Btu.
These costs can be reduced by one third if feedflux values are increased from 140 to 185 lb/hr. Other factors may make the plants viable, such as close proximity of abundant supplies of waste wood --Abstract, page iii
Silicon microstructure arrays for DNA extraction by solid phase sample contacting at high flow rates
Rapid and large sample volume processing capabilities are required for many clinical and environmental point of care genetic diagnostics scenarios. In this paper we describe the development of a silicon monolithic device for high flow rate DNA extraction. The silicon presents silica surfaces and with chaotropic salt solutions can be used for solid phase extraction. The microfluidic device was designed with the aid of simulation methods and consists of a chamber containing a densely packed alternating array of teardrop-shaped microstructures. The microstructures repeatedly separate and recombine flows, and produce a near homogeneous flow distribution to favour DNA contact with the large silica surface areas. Extremely high flow rate operation (e.g. 10 mL min-1 can be achieved without device failure. Low DNA loading and elution flow rates C At high flow rates the DNA extraction capability is retained and is independent of were used to determine a binding capacity of 57 ± 15 ng cm-2 the sample DNA concentration. High flow rate operation is preferred for the rapid extraction of rare DNA species from large sample volumes, and makes the device ideal for inclusion within a fully integrated genetic diagnostics system
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