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.

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>

A high-throughput multiplexed microfluidic device for COVID-19 serology assays

Lab on a Chip ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 93-104
Author(s):  
Roberto Rodriguez-Moncayo ◽  
Diana F. Cedillo-Alcantar ◽  
Pablo E. Guevara-Pantoja ◽  
Oriana G. Chavez-Pineda ◽  
Jose A. Hernandez-Ortiz ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
High Throughput ◽  
Spike Protein ◽  
Serum Samples

A microfluidic device to quantitate antibody reactivities to SARS-CoV-2 antigens: spike protein, RDB, S1 subunit, and nucleocapsid, from 50 serum samples.

Comparison of wavelet continuous transform and signal averaged ECG for high frequency content and late potential detection in healthy individuals

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Garcia Iglesias ◽  
J.M Rubin Lopez ◽  
D Perez Diez ◽  
C Moris De La Tassa ◽  
F.J De Cos Juez ◽  
...  
Keyword(s):  
High Frequency ◽  
Classical Method ◽  
Total Power ◽  
Frequency Content ◽  
Healthy Individuals ◽  
Time Frequency ◽  
Qt Intervals ◽  
Long Time ◽  
Power Content ◽  
High Frequency Content

Abstract Introduction The Signal Averaged ECG (SAECG) is a classical method forSudden Cardiac Death (SCD) risk assessment, by means of Late Potentials (LP) in the filtered QRS (fQRS)[1]. But it is highly dependent on noise and require long time records, which make it tedious to use. Wavelet Continuous Transform (WCT) meanwhile is easier to use, and may let us to measure the High Frequency Content (HFC) of the QRS and QT intervals, which also correlates with the risk of SCD [2,3]. Whether the HFC of the QRS and QT measured with the WCT is a possible subrogate of LP, has never been demonstrated. Objective To demonstrate if there is any relationship between the HFC measured with the WCT and the LP analyzed with the SAECG. Methods Data from 50 consecutive healthy individuals. The standard ECG was digitally collected for 3 consecutive minutes. For the WCT Analysis 8 consecutive QT complexes were used and for the SAECG Analysis all available QRS were used. The time-frequency data of each QT complex were collected using the WCT as previously described [3] and the Total, QRS and QT power were obtained from each patient. For the SAECG, bipolar X, Y and Z leads were used with a bidirectional filter at 40 to 250 Hz [1]. LP were defined as less than 0.05 z in the terminal part of the filtered QRS and the duration (SAECG LP duration) and root mean square (SAECG LP Content) of this LP were calculated. Pearson's test was used to correlate the Power content with WCT analysis and the LP in the SAECG. Results There is a strong correlation between Total Power and the SAECG LP content (r=0.621, p&lt;0.001). Both ST Power (r=0.567, p&lt;0.001) and QRS Power (r=0.404, p=0.004) are related with the SAECG LP content. No correlation were found between the Power content (Total, QRS or ST Power) and the SAECG LP duration. Also no correlation was found between de SAECG LP content and duration. Conclusions Total, QRS and ST Power measured with the WCT are good surrogates of SAECG LP content. No correlation were found between WCT analysis and the SAECG LP duration. Also no correlation was found between the SAECG LP content and duration. This can be of high interest, since WCT is an easier technique, not needing long recordings and being less affected by noise. Funding Acknowledgement Type of funding source: None

Boundary Friction for a Line Contact Model: An Empirical Approach

2015 ◽  
Vol 642 ◽  
pp. 8-12
Author(s):  
William W.F. Chong ◽  
Miguel de La Cruz
Keyword(s):  
Steel Plate ◽  
Friction Model ◽  
Boundary Friction ◽  
Slider Bearing ◽  
Base Oil ◽  
Atomic Force ◽  
Alternative Approach ◽  
Nanoscale Friction ◽  
Friction Measurements ◽  
Good Agreement

The paper introduces an alternative approach to predict boundary friction for rough surfaces at micros-scale through the empirical integration of asperity-like nanoscale friction measurements. The nanoscale friction is measured using an atomic force microscope (AFM) tip sliding on a steel plate, confining the test lubricant, i.e. base oil for the fully formulated SAE grade 10w40. The approach, based on the Greenwood and Tripp’s friction model, is combined with the modified Elrod’s cavitation algorithm in order to predict the friction generated by a slider-bearing test rig. The numerical simulation results, using an improved boundary friction model, showed good agreement with the measured friction data.

scholarly journals Quantification of a Proteotypic Peptide from Protein C Inhibitor by Liquid Chromatography–Free SISCAPA-MALDI Mass Spectrometry: Application to Identification of Recurrence of Prostate Cancer

2013 ◽  
Vol 59 (10) ◽  
pp. 1514-1522 ◽  
Author(s):  
Morteza Razavi ◽  
Lisa DS Johnson ◽  
Julian J Lum ◽  
Gary Kruppa ◽  
N Leigh Anderson ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Liquid Chromatography ◽  
High Throughput ◽  
Protein C ◽  
Specific Antigen ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Biomarker Validation ◽  
Protein C Inhibitor ◽  
Proteotypic Peptide

BACKGROUND Biomarker validation remains one of the most challenging constraints to the development of new diagnostic assays. To facilitate biomarker validation, we previously developed a chromatography-free stable isotope standards and capture by antipeptide antibodies (SISCAPA)-MALDI assay allowing rapid, high-throughput quantification of protein analytes in large sample sets. Here we applied this assay to the measurement of a surrogate proteotypic peptide from protein C inhibitor (PCI) in sera from patients with prostate cancer. METHODS A 2-plex SISCAPA-MALDI assay for quantification of proteotypic peptides from PCI and soluble transferrin receptor (sTfR) was used to measure these peptides in 159 trypsin-digested sera collected from 51 patients with prostate cancer. These patients had been treated with radiation with or without neoadjuvant androgen deprivation. RESULTS Patients who experienced biochemical recurrence of prostate cancer showed decreased serum concentrations of the PCI peptide analyte within 18 months of treatment. The PCI peptide concentrations remained increased in the sera of patients who did not experience cancer recurrence. Prostate-specific antigen concentrations had no predictive value during the same time period. CONCLUSIONS The high-throughput, liquid chromatography–free SISCAPA-MALDI assay is capable of rapid quantification of proteotypic PCI and sTfR peptide analytes in complex serum samples. Decreased serum concentrations of the PCI peptide were found to be related to recurrence of prostate cancer in patients treated with radiation with or without hormone therapy. However, a larger cohort of patients will be required for unequivocal validation of the PCI peptide as a biomarker for clinical use.

Expressions for the effective diffusivity in materials with interphase boundaries

2004 ◽  
Vol 819 ◽  
Author(s):  
Irina V. Belova ◽  
Graeme E. Murch
Keyword(s):  
Polycrystalline Material ◽  
Effective Diffusivity ◽  
Poor Agreement ◽  
Two Phase ◽  
Interphase Boundaries ◽  
Long Time ◽  
Simulation Results ◽  
The Individual ◽  
Individual Grains ◽  
Good Agreement

AbstractWe address the problem of calculating the long-time-limit effective diffusivity in stable two- phase polycrystalline material. A phenomenological model is used where the high diffusivity interphase boundaries are treated as connected “coatings” of the individual grains. Derivation of expressions for the effective diffusivity with segregation is made along Maxwell lines. Monte Carlo simulation using lattice-based random walks is used to test the validity of the expressions. It is shown that for the case analysed the derived expressions for the effective diffusivity are in very good agreement with simulation results. The equivalent of the Hart equation is also derived. It is shown to be in poor agreement with simulation results.

scholarly journals Triadic resonances in precessing rapidly rotating cylinder flows

2015 ◽  
Vol 778 ◽  
Author(s):  
T. Albrecht ◽  
H. M. Blackburn ◽  
J. M. Lopez ◽  
R. Manasseh ◽  
P. Meunier
Keyword(s):  
Rotating Cylinder ◽  
Direct Numerical Simulations ◽  
Mode Shapes ◽  
Resonance Model ◽  
Rapid Rotation ◽  
Nutation Angle ◽  
Resonant Instability ◽  
Theoretical Predictions ◽  
Long Time ◽  
Good Agreement

Direct numerical simulations of flows in cylinders subjected to both rapid rotation and axial precession are presented and analysed in the context of a stability theory based on the triadic resonance of Kelvin modes. For a case that was chosen to provide a finely tuned resonant instability with a small nutation angle, the simulations are in good agreement with the theory and previous experiments in terms of mode shapes and dynamics, including long-time-scale regularization of the flow and recurrent collapses. Cases not tuned to the most unstable triad, but with the nutation angle still small, are also in quite good agreement with theoretical predictions, showing that the presence of viscosity makes the physics of the triadic-resonance model robust to detuning. Finally, for a case with $45^{\circ }$ nutation angle for which it has been suggested that resonance does not occur, the simulations show that a slowly growing triadic resonance predicted by theory is in fact observed if sufficient evolution time is allowed.

New Developments for the Description of Oil Leakages by Advective Migration From Submarine Pipelines

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Renan Martins Baptista ◽  
Ricardo Antonio Francisco Machado ◽  
Marintho Bastos Quadri ◽  
Ariovaldo Bolzan ◽  
André Lourenço Nogueira ◽  
...  
Keyword(s):  
Horizontal Plane ◽  
Immiscible Displacement ◽  
Preliminary Evaluation ◽  
Leakage Detection ◽  
New Developments ◽  
Gravitational Flow ◽  
The Third ◽  
Alternative Approach ◽  
High Standards ◽  
Good Agreement

The significant growth in offshore operations increases the risk of a pipeline rupture, even considering the high standards of safety involved. Throughout a submarine leakage, four different amounts of oil may be accounted. The first one is the oil volume released until the leakage detection. The second one is the volume leaked throughout mitigation initiatives (e.g., pump shutdown and valve closure). The third parcel is the amount released by gravitational flow. Finally, the fourth and last amount of oil is released due to the water-oil entrainment, generally known as advective migration. Normally, a considerable amount of oil is released in this step. It begins just after the internal pipeline pressure becomes equal to the external one. The present work continues to introduce a mathematical alternative approach, based on the theories of perturbation and unstable immiscible displacement, to accurately estimate the leakage kinetics and the amount of oil released by the advective migration phenomenon. Situations considering different hole sizes and thicknesses were tested experimentally and through simulations. Additional experiments were accomplished using smooth and rough edge surfaces, besides different slopes (using the horizontal plane as reference). Those experiments permitted a preliminary evaluation of the importance of these factors. The results obtained with the model showed good agreement with the experimental data in many situations considered.

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