scholarly journals Fabrication Of Sieved-Microwells For Single Particle Capture

2021 ◽  
Author(s):  
Lauren Romita
Keyword(s):  
Microfluidic Device ◽  
High Throughput ◽  
Single Particle ◽  
Particle Deposition ◽  
Ease Of Use ◽  
Fabrication Method ◽  
Particle Capture ◽  
Alternative Approach ◽  
Through Flow ◽  
Wide Range

<div>The use of microwells is popular for a wide range of applications due to its’ ease of use. However, the seeding of conventional microwells, which are closed at the bottom, is restricted to gravitational sedimentation for cell or particle deposition and therefore require lengthy settling times to maximize well occupancy. Microfluidics has accelerated cell or particle capture through flow but is mostly limited to gravitationally-driven settling for capture into the wells. An alternative approach to conventional closed-microwells, sieved microwells supersedes reliance on gravity by using hydrodynamic forces through the open pores at the bottom of the microwells to draw targets into the wells. The aim of this thesis is to develop a rapid and high-throughput fabrication method for sieved microwells and integrate the microwells into a double-layered microfluidic device to enable crossflow trapping. The resulting device achieves an 87% well occupancy in under 10 seconds.</div>

scholarly journals Fabrication Of Sieved-Microwells For Single Particle Capture

2021 ◽  
Author(s):  
Lauren Romita
Keyword(s):  
Microfluidic Device ◽  
High Throughput ◽  
Single Particle ◽  
Particle Deposition ◽  
Ease Of Use ◽  
Fabrication Method ◽  
Particle Capture ◽  
Alternative Approach ◽  
Through Flow ◽  
Wide Range

<div>The use of microwells is popular for a wide range of applications due to its’ ease of use. However, the seeding of conventional microwells, which are closed at the bottom, is restricted to gravitational sedimentation for cell or particle deposition and therefore require lengthy settling times to maximize well occupancy. Microfluidics has accelerated cell or particle capture through flow but is mostly limited to gravitationally-driven settling for capture into the wells. An alternative approach to conventional closed-microwells, sieved microwells supersedes reliance on gravity by using hydrodynamic forces through the open pores at the bottom of the microwells to draw targets into the wells. The aim of this thesis is to develop a rapid and high-throughput fabrication method for sieved microwells and integrate the microwells into a double-layered microfluidic device to enable crossflow trapping. The resulting device achieves an 87% well occupancy in under 10 seconds.</div>

scholarly journals Rapid fabrication of sieved microwells and cross-flow microparticle trapping

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lauren Romita ◽  
Shyan Thompson ◽  
Dae Kun Hwang
Keyword(s):  
Particle Deposition ◽  
Cross Flow ◽  
Particle Dispersion ◽  
Hydrodynamic Forces ◽  
Fabrication Method ◽  
Capture Process ◽  
Step Process ◽  
Alternative Approach ◽  
Rapid Fabrication ◽  
Wide Range

Abstract The use of microwells is popular for a wide range of applications due to its’ simplicity. However, the seeding of conventional microwells, which are closed at the bottom, is restricted to gravitational sedimentation for cell or particle deposition and therefore require lengthy settling times to maximize well occupancy. The addition of microfluidics to the capture process has accelerated cell or particle dispersion and improved capture ability but is mostly limited to gravitationally-driven settling for capture into the wells. An alternative approach to conventional closed-microwells, sieved microwells supersedes reliance on gravity by using hydrodynamic forces through the open pores at the bottom of the microwells to draw targets into the wells. We have developed a rapid fabrication method, based on flow lithography techniques, which allows us to easily customize the mesh pore sizes in a simple two-step process. Finally, by combining this microwell design with cross-flow trapping in a microfluidic two-layered channel, we achieve an 88 ± 6% well occupancy in under 10 s.

scholarly journals 230 Genome editing applications in plants: high-throughput CRISPR/Cas editing for crop improvement

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 56-56
Author(s):  
Michael Thomson
Keyword(s):  
Genome Editing ◽  
High Throughput ◽  
Positional Cloning ◽  
Gene Editing ◽  
Crop Improvement ◽  
Cost Effective ◽  
Gene Families ◽  
Ease Of Use ◽  
Plant Genome ◽  
Wide Range

Abstract The precision and ease of use of CRISPR nucleases, such as Cas9 and Cpf1, for plant genome editing has the potential to accelerate a wide range of applications for crop improvement. For upstream research on gene discovery and validation, rapid gene knock-outs can enable testing of single genes and multi-gene families for functional effects. Large chromosomal deletions can test the function of tandem gene arrays and assist with positional cloning of QTLs by helping to narrow down the target region. Nuclease-deactivated Cas9 fusion proteins with transcriptional activators and repressors can be used to up and down-regulate gene expression. Even more promising, gene insertions and allele replacements can provide the opportunity to rapidly test the effects of different alleles at key loci in the same genetic background, providing a more precise alternative to marker-assisted backcrossing. Recently, Texas A&M AgriLife Research has supported the development of a Crop Genome Editing Lab at Texas A&M working towards optimizing a high-throughput gene editing pipeline and providing an efficient and cost-effective gene editing service for research and breeding groups. The lab is using rice as a model to test and optimize new approaches aimed towards overcoming current bottlenecks. For example, a wealth of genomics data from the rice community enables the development of novel approaches to predict which genes and target modifications may be most beneficial for crop improvement, taking advantage of known major genes, high-resolution GWAS data, multiple high-quality reference genomes, transcriptomics data, and resequencing data from the 3,000 Rice Genomes Project. Current projects have now expanded to work across multiple crops to provide breeding and research groups with a rapid gene editing pipeline to test candidate genes in their programs, with the ultimate goal of developing nutritious, high-yielding, stress-tolerant crops for the future.

scholarly journals seqCAT: a Bioconductor R-package for variant analysis of high throughput sequencing data

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1466 ◽  
Author(s):  
Erik Fasterius ◽  
Cristina Al-Khalili Szigyarto
Keyword(s):  
Genetic Variation ◽  
Liver Cancer ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
R Package ◽  
Ease Of Use ◽  
Sequencing Data ◽  
Dna And Rna ◽  
High Throughput Sequencing Data ◽  
Wide Range

High throughput sequencing technologies are flourishing in the biological sciences, enabling unprecedented insights into e.g. genetic variation, but require extensive bioinformatic expertise for the analysis. There is thus a need for simple yet effective software that can analyse both existing and novel data, providing interpretable biological results with little bioinformatic prowess. We present seqCAT, a Bioconductor toolkit for analysing genetic variation in high throughput sequencing data. It is a highly accessible, easy-to-use and well-documented R-package that enables a wide range of researchers to analyse their own and publicly available data, providing biologically relevant conclusions and publication-ready figures. SeqCAT can provide information regarding genetic similarities between an arbitrary number of samples, validate specific variants as well as define functionally similar variant groups for further downstream analyses. Its ease of use, installation, complete data-to-conclusions functionality and the inherent flexibility of the R programming language make seqCAT a powerful tool for variant analyses compared to already existing solutions. A publicly available dataset of liver cancer-derived organoids is analysed herein using the seqCAT package, demonstrating that the organoids are genetically stable. A previously known liver cancer-related mutation is additionally shown to be present in a sample though it was not listed in the original publication. Differences between DNA- and RNA-based variant calls in this dataset are also analysed revealing a high median concordance of 97.5%.

scholarly journals Measurement of Carcinoembryonic Antigen in Clinical Serum Samples Using a Centrifugal Microfluidic Device

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 470 ◽  
Author(s):  
Zhigang Gao ◽  
Zongzheng Chen ◽  
Jiu Deng ◽  
Xiaorui Li ◽  
Yueyang Qu ◽  
...  
Keyword(s):  
Carcinoembryonic Antigen ◽  
Microfluidic Device ◽  
High Throughput ◽  
Classical Method ◽  
Gradient Centrifugation ◽  
Serum Samples ◽  
Clinical Method ◽  
Alternative Approach ◽  
Long Time ◽  
Good Agreement

Carcinoembryonic antigen (CEA) is a broad-spectrum tumor marker used in clinical applications. The primarily clinical method for measuring CEA is based on chemiluminescence in serum during enzyme-linked immunosorbent assays (ELISA) in 96-well plates. However, this multi-step process requires large and expensive instruments, and takes a long time. In this study, a high-throughput centrifugal microfluidic device was developed for detecting CEA in serum without the need for cumbersome washing steps normally used in immunoreactions. This centrifugal microdevice contains 14 identical pencil-like units, and the CEA molecules are separated from the bulk serum for subsequent immunofluorescence detection using density gradient centrifugation in each unit simultaneously. To determine the optimal conditions for CEA detection in serum, the effects of the density of the medium, rotation speed, and spin duration were investigated. The measured values from 34 clinical serum samples using this high-throughput centrifugal microfluidic device showed good agreement with the known values (average relative error = 9.22%). These results indicate that the high-throughput centrifugal microfluidic device could provide an alternative approach for replacing the classical method for CEA detection in clinical serum samples.

Particulate and Emulsion Sorting Using Microfluidics

2014 ◽  
Author(s):  
Li Lu ◽  
Rebecca M. Irwin ◽  
Jeffrey W. Schertzer ◽  
Paul R. Chiarot
Keyword(s):  
Microfluidic Device ◽  
High Throughput ◽  
Hydrodynamic Forces ◽  
Fluid Stream ◽  
High Concentration ◽  
Flow Rates ◽  
Membrane Biology ◽  
Wide Range ◽  
Delivery Vehicles ◽  
Oil Emulsions

We report on a microfluidic device capable of sorting nanoscale particulates and water-in-oil emulsions at high-throughput. The device is passive, relying solely on hydrodynamic forces and the emulsion mass to achieve separation. We use the microfluidic device to deliver surfactants and lipids to the emulsion surface. This is achieved by immersing the emulsions in a fluid stream with a high concentration of the nano-particulates. The particulates assemble on the surface of the emulsions as they are transported along the stream. The emulsions are then transferred (i.e. separated) into a second fluid stream that is devoid of surrounding material. The performance of the device is evaluated for a range of flow rates, nano-particulate concentrations, and emulsion sizes. We report separation efficiencies that exceed current technologies over a wide range of flow rates. The microfluidic device can be used to produce delivery vehicles for pharmaceuticals and models for membrane biology studies.

scholarly journals seqCAT: a Bioconductor R-package for variant analysis of high throughput sequencing data

F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 1466 ◽  
Author(s):  
Erik Fasterius ◽  
Cristina Al-Khalili Szigyarto
Keyword(s):  
Genetic Variation ◽  
Liver Cancer ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
R Package ◽  
Ease Of Use ◽  
Sequencing Data ◽  
Dna And Rna ◽  
High Throughput Sequencing Data ◽  
Wide Range

High throughput sequencing technologies are flourishing in the biological sciences, enabling unprecedented insights into e.g. genetic variation, but require extensive bioinformatic expertise for the analysis. There is thus a need for simple yet effective software that can analyse both existing and novel data, providing interpretable biological results with little bioinformatic prowess. We present seqCAT, a Bioconductor toolkit for analysing genetic variation in high throughput sequencing data. It is a highly accessible, easy-to-use and well-documented R-package that enables a wide range of researchers to analyse their own and publicly available data, providing biologically relevant conclusions and publication-ready figures. SeqCAT can provide information regarding genetic similarities between an arbitrary number of samples, validate specific variants as well as define functionally similar variant groups for further downstream analyses. Its ease of use, installation, complete data-to-conclusions functionality and the inherent flexibility of the R programming language make seqCAT a powerful tool for variant analyses compared to already existing solutions. A publicly available dataset of liver cancer-derived organoids is analysed herein using the seqCAT package, corroborating the original authors' conclusions that the organoids are genetically stable. A previously known liver cancer-related mutation is additionally shown to be present in a sample though it was not listed in the original publication. Differences between DNA- and RNA-based variant calls in this dataset are also analysed revealing a high median concordance of 97.5%. SeqCAT is an open source software under a MIT licence available at https://bioconductor.org/packages/release/bioc/html/seqCAT.html.

Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability

2019 ◽  
Author(s):  
Theodoros Tsoulos ◽  
Supriya Atta ◽  
Maureen Lagos ◽  
Michael Beetz ◽  
Philip Batson ◽  
...  
Keyword(s):  
Single Particle ◽  
Structural Complexity ◽  
Field Enhancement ◽  
Hot Electron ◽  
Structure Property ◽  
Plasmon Band ◽  
Gold Nanostars ◽  
Wide Range ◽  
Particle Level ◽  
Spectrally Resolved

<div>Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags or phototherapeutic agents, or to design novel hot-electron based photocatalysts. From a fundamental standpoint, they represent important tunable platforms to study the dependence of hot carrier energy and dynamics on plasmon band intensity and position. Toward the realization of these platforms, holistic approaches taking into account both theory and experiments to study the fundamental behavior of these</div><div>particles are needed. Arguably, the intrinsic difficulties underlying this goal stem from the inability to rationally design and effectively synthesize nanoparticles that are sufficiently monodispersed to be employed for corroborations of the theoretical results without the need of single particle experiments. Herein, we report on our concerted computational and experimental effort to design, synthesize, and explain the origin and morphology-dependence of the plasmon modes of a novel gold nanostar system, with an approach that builds upon the well-known plasmon hybridization model. We have synthesized monodispersed samples of gold nanostars with finely tunable morphology employing seed-mediated colloidal protocols, and experimentally observed narrow and spectrally resolved harmonics of the primary surface plasmon resonance mode both at the single particle level (via electron energy loss spectroscopy) and in ensemble (by UV-Vis and ATR-FTIR spectroscopies). Computational results on complex anisotropic gold nanostructures are validated experimentally on samples prepared colloidally, underscoring their importance as ideal testbeds for the study of structure-property relationships in colloidal nanostructures of high structural complexity.</div>

From the history of the development of electronic dictionaries: foreign and domestic experience

2020 ◽  
Vol 11 (1) ◽  
pp. 6-12
Author(s):  
O. Y. Balalaieva ◽  
Keyword(s):  
Human Activity ◽  
Current Level ◽  
Ease Of Use ◽  
Advanced Search ◽  
Wide Range ◽  
Promising Area ◽  
History Of ◽  
Machine Readable ◽  
Everyday Communication ◽  
Educational Professional

The purpose of the article is to study the dynamics of electronic dictionaries development abroad and in Ukraine using methods of analysis of scientific sources, comparison, generalization and systematization. Electronic dictionaries have been found to be a relatively new phenomenon in the lexicographic market, evolving from machine-readable dictionaries, exact copies of paper editions to complex digital lexicographic systems with a powerful arsenal of functions over the decades. The stages of development of autonomous and online dictionaries are described. Electronic dictionaries due to the advanced search capabilities, speed, simplicity, ease of use, accessibility and compactness have gained popularity among a wide range of users. Today they are used in many spheres of human activity – scientific, educational, professional, everyday communication. However, the analysis of the current level of development of Ukrainian electronic resources indicates a shortage of electronic dictionaries both common and terminological vocabulary. The lack of electronic dictionaries is due to a number of objective problems, both practical and theoretical, that is why research in the field of domestic computer lexicography is a promising area of further research.

scholarly journals A Numerical Study of the Effect of Particle Size on Particle Deposition on Turbine Vanes and Blades

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110178
Author(s):  
Zhengang Liu ◽  
Weinan Diao ◽  
Zhenxia Liu ◽  
Fei Zhang
Keyword(s):  
Particle Size ◽  
Particle Deposition ◽  
Numerical Study ◽  
Stokes Number ◽  
Capture Efficiency ◽  
Particle Capture ◽  
Factors Affecting ◽  
Pressure Surface ◽  
Deposition Area ◽  
Turbine Vanes

Particle deposition could decrease the aerodynamic performance and cooling efficiency of turbine vanes and blades. The particle motion in the flow and its temperature are two important factors affecting its deposition. The size of the particle influences both its motion and temperature. In this study, the motion of particles with the sizes from 1 to 20 μm in the first stage of a turbine are firstly numerically simulated with the steady method, then the particle deposition on the vanes and blades are numerically simulated with the unsteady method based on the critical viscosity model. It is discovered that the particle deposition on vanes mainly formed near the leading and trailing edge on the pressure surface, and the deposition area expands slowly to the whole pressure surface with the particle size increasing. For the particle deposition on blades, the deposition area moves from the entire pressure surface toward the tip with the particle size increasing due to the effect of rotation. For vanes, the particle capture efficiency increases with the particle size increasing since Stokes number and temperature of the particle both increase with its size. For blades, the particle capture efficiency increases firstly and then decreases with the particle size increasing.

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