scholarly journals A Microfluidic Device for Automated High Throughput Detection of Ice Nucleation of Snomax®

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 296
Author(s):  
Priyatanu Roy ◽  
Margaret House ◽  
Cari Dutcher
Keyword(s):  
Heat Treatment ◽  
Microfluidic Device ◽  
High Throughput ◽  
Pure Water ◽  
Ice Nucleation ◽  
Food Storage ◽  
Detection Methods ◽  
Microfluidic Platform ◽  
Ambient Temperatures ◽  
Effects Of Aging

Measurement of ice nucleation (IN) temperature of liquid solutions at sub-ambient temperatures has applications in atmospheric, water quality, food storage, protein crystallography and pharmaceutical sciences. Here we present details on the construction of a temperature-controlled microfluidic platform with multiple individually addressable temperature zones and on-chip temperature sensors for high-throughput IN studies in droplets. We developed, for the first time, automated droplet freezing detection methods in a microfluidic device, using a deep neural network (DNN) and a polarized optical method based on intensity thresholding to classify droplets without manual counting. This platform has potential applications in continuous monitoring of liquid samples consisting of aerosols to quantify their IN behavior, or in checking for contaminants in pure water. A case study of the two detection methods was performed using Snomax® (Snomax International, Englewood, CO, USA), an ideal ice nucleating particle (INP). Effects of aging and heat treatment of Snomax® were studied with Fourier transform infrared (FTIR) spectroscopy and a microfluidic platform to correlate secondary structure change of the IN protein in Snomax® to IN temperature. It was found that aging at room temperature had a mild impact on the ice nucleation ability but heat treatment at 95 °C had a more pronounced effect by reducing the ice nucleation onset temperature by more than 7 °C and flattening the overall frozen fraction curve. Results also demonstrated that our setup can generate droplets at a rate of about 1500/min and requires minimal human intervention for DNN classification.

A versatile microfluidic device for high throughput production of microparticles and cell microencapsulation

Lab on a Chip ◽  
2017 ◽  
Vol 17 (12) ◽  
pp. 2067-2075 ◽  
Author(s):  
Samin Akbari ◽  
Tohid Pirbodaghi ◽  
Roger D. Kamm ◽  
Paula T. Hammond
Keyword(s):  
Production Rate ◽  
Microfluidic Device ◽  
High Throughput ◽  
Microfluidic Platform ◽  
Generation Frequency ◽  
Cell Microencapsulation

We introduce a robust microfluidic platform for production of relatively homogenous microdroplets at generation frequency of up to 3.1 MHz, about three orders of magnitude higher than the production rate of a conventional microfluidic dropmaker.

scholarly journals A generalised approach for high-throughput instance segmentation of stomata in microscope images

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Hiranya Jayakody ◽  
Paul Petrie ◽  
Hugo Jan de Boer ◽  
Mark Whitty
Keyword(s):  
High Throughput ◽  
Imaging Techniques ◽  
Detection Algorithm ◽  
Input Image ◽  
Detection Methods ◽  
Sample Collection ◽  
High Throughput Analysis ◽  
General Applicability ◽  
Additional Image ◽  
Bounding Boxes

Abstract Background Stomata analysis using microscope imagery provides important insight into plant physiology, health and the surrounding environmental conditions. Plant scientists are now able to conduct automated high-throughput analysis of stomata in microscope data, however, existing detection methods are sensitive to the appearance of stomata in the training images, thereby limiting general applicability. In addition, existing methods only generate bounding-boxes around detected stomata, which require users to implement additional image processing steps to study stomata morphology. In this paper, we develop a fully automated, robust stomata detection algorithm which can also identify individual stomata boundaries regardless of the plant species, sample collection method, imaging technique and magnification level. Results The proposed solution consists of three stages. First, the input image is pre-processed to remove any colour space biases occurring from different sample collection and imaging techniques. Then, a Mask R-CNN is applied to estimate individual stomata boundaries. The feature pyramid network embedded in the Mask R-CNN is utilised to identify stomata at different scales. Finally, a statistical filter is implemented at the Mask R-CNN output to reduce the number of false positive generated by the network. The algorithm was tested using 16 datasets from 12 sources, containing over 60,000 stomata. For the first time in this domain, the proposed solution was tested against 7 microscope datasets never seen by the algorithm to show the generalisability of the solution. Results indicated that the proposed approach can detect stomata with a precision, recall, and F-score of 95.10%, 83.34%, and 88.61%, respectively. A separate test conducted by comparing estimated stomata boundary values with manually measured data showed that the proposed method has an IoU score of 0.70; a 7% improvement over the bounding-box approach. Conclusions The proposed method shows robust performance across multiple microscope image datasets of different quality and scale. This generalised stomata detection algorithm allows plant scientists to conduct stomata analysis whilst eliminating the need to re-label and re-train for each new dataset. The open-source code shared with this project can be directly deployed in Google Colab or any other Tensorflow environment.

A microfluidic platform for the high-throughput study of pathological cardiac hypertrophy

Lab on a Chip ◽  
2017 ◽  
Vol 17 (19) ◽  
pp. 3264-3271 ◽  
Author(s):  
Hesam Parsa ◽  
Bryan Z. Wang ◽  
Gordana Vunjak-Novakovic
Keyword(s):  
Cardiac Hypertrophy ◽  
High Throughput ◽  
Volume Overload ◽  
Microfluidic Platform ◽  
Pathological Cardiac Hypertrophy ◽  
High Throughput Study

Currentin vitromodels fall short in deciphering the mechanisms of cardiac hypertrophy induced by volume overload.

scholarly journals Advances in the Use of Microfluidics to Study Crystallization Fundamentals

2019 ◽  
Vol 10 (1) ◽  
pp. 59-83 ◽  
Author(s):  
Nadine Candoni ◽  
Romain Grossier ◽  
Mehdi Lagaize ◽  
Stéphane Veesler
Keyword(s):  
Phase Diagram ◽  
Diffraction Analysis ◽  
High Throughput ◽  
Concentration Measurement ◽  
Ultraviolet Spectroscopy ◽  
X Ray Diffraction ◽  
Chemical Library ◽  
Microfluidic Platform ◽  
X Ray ◽  
Phase Diagram Determination

This review compares droplet-based microfluidic systems used to study crystallization fundamentals in chemistry and biology. An original high-throughput droplet-based microfluidic platform is presented. It uses nanoliter droplets, generates a chemical library, and directly solubilizes powder, thus economizing both material and time. It is compatible with all solvents without the need for surfactant. Its flexibility permits phase diagram determination and crystallization studies (screening and optimizing experiments) and makes it easy to use for nonspecialists in microfluidics. Moreover, it allows concentration measurement via ultraviolet spectroscopy and solid characterization via X-ray diffraction analysis.

scholarly journals Ice nucleation activity of silicates and aluminosilicates in pure water and aqueous solutions – Part 2: Quartz and amorphous silica

2019 ◽  
Vol 19 (9) ◽  
pp. 6035-6058 ◽  
Author(s):  
Anand Kumar ◽  
Claudia Marcolli ◽  
Thomas Peter
Keyword(s):  
Aqueous Solutions ◽  
Amorphous Silica ◽  
Pure Water ◽  
Ice Nucleation ◽  
Water Volume ◽  
Special Focus ◽  
Quartz Surface ◽  
Mineral Surface ◽  
Glass Vial ◽  
Immersion Freezing

Abstract. Divergent ice nucleation (IN) efficiencies of quartz, an important component of atmospheric mineral dust, have been reported in previous studies. We show here that quartz particles obtain their IN activity from milling and that quartz aged in water loses most of its IN efficiency relative to freshly milled quartz. Since most studies so far reported IN activities of commercial quartz dusts that were milled already by the manufacturer, IN active samples prevailed. Also, the quartz surface – much in contrast to that of feldspars – is not prone to ammonia-induced IN enhancement. In detail we investigate the influence of solutes on the IN efficiency of various silica (SiO2) particles (crystalline and amorphous) with special focus on quartz. We performed immersion freezing experiments and relate the observed variability in IN activity to the influence of milling, the aging time and to the exposure conditions since milling. Immersion freezing with silica particles suspended in pure water or aqueous solutions of NH3, (NH4)2SO4, NH4HSO4, Na2SO4 and NaOH, with solute concentrations corresponding to water activities aw=0.9–1.0, were investigated in emulsified droplets by means of differential scanning calorimetry (DSC) and analyzed in terms of the onset temperature of the heterogeneous freezing signal Thet and the heterogeneously frozen water volume fraction Fhet. Quartz particles, which originate from milling coarse samples, show a strong heterogeneous freezing peak in pure water with Thet equal to 247–251 K. This IN activity disappears almost completely after aging for 7 months in pure water in a glass vial. During this time quartz slowly grew by incorporating silicic acid leached from the glass vial. Conversely, the synthesized amorphous silica samples show no discernable heterogeneous freezing signal unless they were milled. This implies that defects provide IN activity to silica surfaces, whereas the IN activity of a natural quartz surface is negligible, when it grew under near-equilibrium conditions. For suspensions containing milled quartz and the solutes (NH4)2SO4, NH4HSO4 or Na2SO4, Thet approximately follows ThetΔawhet(aw), the heterogeneous freezing onset temperatures that obey Δawhet criterion, i.e., ThetΔawhet(aw)=Tmelt(aw+Δawhet) with Δawhet being a constant offset with respect to the ice melting point curve, similar to homogeneous IN. This water-activity-based description is expected to hold when the mineral surface is not altered by the presence of the solutes. On the other hand, we observe a slight enhancement in Fhet in the presence of these solutes, implying that the compliance with the Δawhet criterion does not necessarily imply constant Fhet. In contrast to the sulfates, dilute solutions of NH3 or NaOH (molality ≥5×10-4 mol kg−1) reveal Thet by 3–8 K lower than ThetΔawhet(aw), indicating a significant impact on the mineral surface. The lowering of Thet of quartz suspended in dilute NH3 solutions is opposite to the distinct increase in Thet that we found in emulsion freezing experiments with aluminosilicates, namely feldspars, kaolinite, gibbsite and micas. We ascribe this decrease in IN activity to the increased dissolution of quartz under alkaline conditions. The defects that constitute the active sites appear to be more susceptible to dissolution and therefore disappear first on a dissolving surface.

scholarly journals Microfluidic on-demand droplet generation, storage, retrieval, and merging for single-cell pairing

Lab on a Chip ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 493-502 ◽  
Author(s):  
Hesam Babahosseini ◽  
Tom Misteli ◽  
Don L. DeVoe
Keyword(s):  
Single Cell ◽  
Aqueous Phase ◽  
Microfluidic Device ◽  
Droplet Generation ◽  
Microfluidic Platform ◽  
On Demand

A multifunctional microfluidic platform combining on-demand aqueous-phase droplet generation, multi-droplet storage, and controlled merging of droplets selected from a storage library in a single integrated microfluidic device is described.

scholarly journals Ultra-high capacity microfluidic trapping of giant vesicles for high-throughput membrane studies

Lab on a Chip ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 626-633 ◽  
Author(s):  
Naresh Yandrapalli ◽  
Tom Robinson
Keyword(s):  
High Throughput ◽  
High Capacity ◽  
Giant Vesicles ◽  
Microfluidic Platform

A high-capacity microfluidic platform designed to capture tens of thousands of giant vesicles for high-throughput membrane analysis.

Freezing of micrometer-sized liquid droplets of pure water evaporatively cooled in a vacuum

2018 ◽  
Vol 20 (45) ◽  
pp. 28435-28444 ◽  
Author(s):  
Kota Ando ◽  
Masashi Arakawa ◽  
Akira Terasaki
Keyword(s):  
Pure Water ◽  
Ice Nucleation ◽  
Nucleation Theory ◽  
Liquid Droplets ◽  
Freezing Time ◽  
Water Droplets

The freezing time of pure-water droplets is measured in a vacuum and simulated by ice nucleation theory.

Robust hybridization-based genotyping probes for HPV 6, 11, 16 and 18 obtained via in vitro selection

2010 ◽  
Vol 1 (1) ◽  
pp. 3
Author(s):  
Ivan B. Brukner ◽  
Anne-Marie Larose ◽  
Izabella Gorska-Flipot ◽  
Maja Krajinovic ◽  
Damian Labuda
Keyword(s):  
Rational Design ◽  
In Vitro Selection ◽  
Clinical Performance ◽  
Initial Step ◽  
Detection Methods ◽  
Ambient Temperatures ◽  
Hybridization Probes ◽  
Specificity And Sensitivity ◽  
Hpv Types

This paper describes the technical and analytical performance of a novel set of hybridization probes for the four GARDASIL® vaccine-relevant HPV types (6, 11, 16 and 18). These probes are obtained through i<em>n vitro </em>selection from a pool of random oligonucleotides, rather than the traditional “rational design” approach typically used as the initial step in assay development. The type-specific segment of the HPV genome was amplified using a GP5+/6+ PCR protocol and 39 synthetic oligonucleotide templates derived from each of the HPV types, as PCR targets. The robust performance of the 4 selected hybridization probes was demonstrated by monitoring the preservation of the specificity and sensitivity of the typing assay over all 39 HPV types, using a different spectrum of HPV (genome equivalent: 103-109) and human DNA concentrations (10-100 ng) as well as temperature and buffer composition variations. To the Authors’ knowledge, this is a unique hybridization-based multiplex typing assay. It performs at ambient temperatures, does not require the strict temperature control of hybridization conditions, and is functional with a number of different non-denaturing buffers, thereby offering downstream compatibility with a variety of detection methods. Studies aimed at demonstrating clinical performance are needed to validate the applicability of this strategy.

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