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1 – 10 of 394Mehdi Habibi, Yunus Dawji, Ebrahim Ghafar-Zadeh and Sebastian Magierowski
Nanopore-based molecular sensing and measurement, specifically DNA sequencing, is advancing at a fast pace. Some embodiments have matured from coarse particle counters to enabling…
Abstract
Purpose
Nanopore-based molecular sensing and measurement, specifically DNA sequencing, is advancing at a fast pace. Some embodiments have matured from coarse particle counters to enabling full human genome assembly. This evolution has been powered not only by improvements in the sensors themselves, but also in the assisting microelectronic CMOS readout circuitry closely interfaced to them. In this light, this paper aims to review established and emerging nanopore-based sensing modalities considered for DNA sequencing and CMOS microelectronic methods currently being used.
Design/methodology/approach
Readout and amplifier circuits, which are potentially appropriate for conditioning and conversion of nanopore signals for downstream processing, are studied. Furthermore, arrayed CMOS readout implementations are focused on and the relevant status of the nanopore sensor technology is reviewed as well.
Findings
Ion channel nanopore devices have unique properties compared with other electrochemical cells. Currently biological nanopores are the only variants reported which can be used for actual DNA sequencing. The translocation rate of DNA through such pores, the current range at which these cells operate on and the cell capacitance effect, all impose the necessity of using low-noise circuits in the process of signal detection. The requirement of using in-pixel low-noise circuits in turn tends to impose challenges in the implementation of large size arrays.
Originality/value
The study presents an overview on the readout circuits used for signal acquisition in electrochemical cell arrays and investigates the specific requirements necessary for implementation of nanopore-type electrochemical cell amplifiers and their associated readout electronics.
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Abstract
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Acoustic pattern recognition has shown itself to be a powerful inspection aid.
Linlin Wang, Jianyao Yao, Huiming Ning, Liangke Wu, Dongyang Sun and Ning Hu
This paper aims to investigate the effects of the pia matter on cerebral cortical folding.
Abstract
Purpose
This paper aims to investigate the effects of the pia matter on cerebral cortical folding.
Design/methodology/approach
A three-layer buckling simulation model composited by the white matter, gray matter and the pia matter is adopted to analyze the effect of the pia matter on cortical folding. The volume growth of brain tissues is simulated using thermal expansion. The effects of the pia matter growth rate, thickness and stiffness on cortical folding is investigated.
Findings
The simulation results show that all of these three aforementioned factors of pia matter have obvious effects on cerebral cortical folding. Especially, the thickening of the pia matter may lead to cortical folding malformation such as polymicrogyria, which is in good agreement with the recent reported anatomical findings.
Originality/value
The three-layer model in this paper composited by the white matter, gray matter and the pia matter is different from the usually used two-layer model only composited by the white matter and gray matter. This three-layer model has successfully validated the effect of the pia matter on cerebral cortical folding. The simulation results can explain the anatomical findings very well.
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Jose Maria Lopez Pedrosa and Mark Bradley
The purpose of this paper is to develop a high‐throughput approach to optimize printing of pigment‐based formulations.
Abstract
Purpose
The purpose of this paper is to develop a high‐throughput approach to optimize printing of pigment‐based formulations.
Design/methodology/approach
A total of 40 formulations were robotically prepared by varying the concentrations of diethyleneglycol, glycerol and surfynol. In addition, a variety of inkjet printer (process) variables (voltage, pulse width and frequency) was varied. The combined influence of these two sets of variables on printing performance were determined, analysed and optimised using the Statistical Software Package (MODDE 8), which uses multiple linear regression and partial least square analysis.
Findings
The components diethyleneglycol and surfynol were observed to predominantly control viscosity and surface tension of all formulations, which voltage and pulse width were found to be the main factors controlling the spread of the droplet on the substrate.
Practical implications
Optimisation of pigment‐based formulations has typically involved the one‐by‐one systematic variation of components in a stepwise manner. The work reported here allowed the generation of a robust model allowing the properties of any new formulation to be accurately predicted. Importantly, the experimental tools and methods developed can be applied quite generally to the preparation of any new formulation for inkjet printing application.
Originality/value
Experimental design and high‐throughput technology allow new formulations to be accurately predicted for diverse inkjet applications.
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Benjamin T. Schmidt, Joseph M. Feduska, Ashley M. Witt and Bridget M. Deasy
The purpose of this paper is to focus on the advantages of a robotic time‐lapsed microscopic imaging system for tracking stem cells in in vitro biological assays which measure…
Abstract
Purpose
The purpose of this paper is to focus on the advantages of a robotic time‐lapsed microscopic imaging system for tracking stem cells in in vitro biological assays which measure stem cell activities.
Design/methodology/approach
The unique aspects of the system include robotic movement of stem cell culture flasks which enables selection of a large number of regions of interest for data collection. Numerous locations of a cell culture flask can be explored and selected for time‐lapsed analysis. The system includes an environmentally controlled chamber to maintain experimental conditions including temperature, gas levels, and humidity, such that stem cells can be tracked by visible and epifluorescence imaging over extended periods of time.
Findings
This is an extremely unique system for both individual cell tracking and cell population tracking in real‐time with high‐throughput experimental capability. In comparison to a conventional manual cell culture and assay approach, this system provides stem cell biologists with the ability to quantify numerous and unique temporal changes in stem cell populations, this drastically reduces man‐hours, consumes fewer laboratory resources and provides standardization to biological assays.
Research limitations/implications
Fundamental basic biology questions can be addressed using this approach.
Practical implications
Stem cells are often available only in small numbers – due both to their inherent low frequency in the post‐natal tissue as compared to somatic cells, and their slow growth rates. The unique capabilities of this robotic cell culture system allow for the study of cell populations which are few in number.
Originality/value
The robotic time‐lapsed imaging system is a novel approach to stem cell research.
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In SMT manufacturing, automation is the key to achieving the highest throughput at the lowest cost. Complex devices of various shapes and sizes often require final electrical…
Abstract
In SMT manufacturing, automation is the key to achieving the highest throughput at the lowest cost. Complex devices of various shapes and sizes often require final electrical adjustments under operating conditions to ensure conformance to electrical specifications. This paper describes the process of laser trimming completed SMT devices and the advantages it has over conventional trimming methods. The material presented is based on laser trimming systems currently used in SMT production applications that will also be described.
V. Nemkov, R. Ruffini, R. Goldstein, J. Jackowski, T.L. DeWeese and R. Ivkov
The purpose of this paper is to continue studies previously reported with the primary focus of optimizing an inductor design. The potential benefits of hyperthermia for cancer…
Abstract
Purpose
The purpose of this paper is to continue studies previously reported with the primary focus of optimizing an inductor design. The potential benefits of hyperthermia for cancer therapy, particularly metastatic cancers of the prostate, may be realized by the use of targeted magnetic nanoparticles that are heated by alternating magnetic fields (AMFs).
Design/methodology/approach
To further explore the potential of this technology, a high‐throughput cell culture treatment system is needed. The AMF requirements for this research present challenges to the design and manufacture of an induction system because a high flux density field at high frequency must be created in a relatively large volume. Additional challenges are presented by the requirement that the inductor must maintain an operating temperature between 35 and 39°C with continuous duty operation for 1 h or longer. Results of simulation and design of two devices for culture samples and for in vitro tests of multiple samples in uniform field are described.
Findings
The inductor design chosen provides a uniform distribution of relatively high magnetic field strength while providing an optimal reduction in the voltage and power requirement. Through development of design and selection of magnetic concentrator, the exposure of the cell cultures to the heat generated by the inductor is minimized.
Originality/value
This method of generating uniform high AC magnetic fields in a large volume is beneficial for the study of hyperthermia in cells for a high throughput, necessary for cancer treatment research.
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