scholarly journals Ozone Detection by Crack-Induced Opacity in Rubber

1999 ◽  
Vol 72 (4) ◽  
pp. 769-778 ◽  
Author(s):  
P. H. Mott ◽  
C. M. Roland
Keyword(s):  
Dynamic Range ◽  
Crack Nucleation ◽  
High Sensitivity ◽  
Nucleation And Growth ◽  
Atmospheric Ozone ◽  
Surface Cracks ◽  
Broad Dynamic Range ◽  
Consequent Reduction ◽  
Ozone Detection ◽  
Crack Nucleation And Growth

Abstract Initially transparent polybutadiene develops micron-sized surface cracks when stretched and exposed to ozone. The consequent reduction in the transparency of the rubber provides a facile method for quantifying the ambient ozone concentration. The rate at which opacity develops is linearly dependent on the amount of ozone, and increases with increasing strain. This method of detecting atmospheric ozone has high sensitivity (1 ppb), a broad dynamic range, and is unaffected by the presence of other chemicals. The surface morphology of exposed material can be interpreted in terms of crack nucleation and growth.

Ultra-sensitive detection of biomarkers and applications in pharmaceutical discovery and development. Example application to rat cardiac troponin I assay via nanoparticle probes

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14594-e14594
Author(s):  
P. Bao ◽  
T. Lubben ◽  
T. Holzman
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Cardiac Troponin I ◽  
Drug Induced ◽  
Drug Candidates ◽  
Broad Dynamic Range ◽  
Probe Test ◽  
Detection Of Biomarkers

e14594 Although specific to heart, rat cardiac troponin I (cTnI) is an example of an important biomarker for assessing drug-induced cardiotoxicity in animal models used in various phases of drug discovery and development. Current commercially available assays can only detect 10 ∼ 100 pg/mL in serum at the lowest limits. To improve the sensitivity of rat cTnI assay, we have developed a generically applicable, microarray based nano-probe test. Our rat cTnI assay algorithm uses a multi-step robotic process, which relies on non- isotropically oriented antibodies on functionalized glass as multiplexed microarrays to capture cTnI from serum. Functionalized, 130 angstrom diameter gold nano-probes (measured by static light scattering, 5 nm S.D.) also bind to the troponin through a molecular-scale complex containing antibodies. The troponin-bound molecular complex is then quantified through silver enhancement of the functionalized gold. Assays in this format can be rapidly configured and implemented for a wide array of potential biomarkers. For cTnI we have demonstrated a robust and ultra-sensitive assay with an LOD of less than 500 femtograms of rat cTnI per mL serum, and an overall CV of less than 20%. The assay also shows very low background, a broad dynamic range and over 3 logs of linear dose response. As an example of the potential of high sensitivity, the nanoparticle-based rat cTnI assay could significantly increase the effectiveness of measuring drug-induced heart damage at very low drug dosages and early times. Such sensitive and early measurements can improve examination of the safety of drug candidates while correspondingly reducing drug development time and cost. [Table: see text]

Probabilistic Treatment of Crack Nucleation and Growth for Gas Turbine Engine Materials

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
M. P. Enright ◽  
R. C. McClung ◽  
S. J. Hudak ◽  
W. L. Francis
Keyword(s):  
Gas Turbine ◽  
Life Prediction ◽  
Crack Nucleation ◽  
Gas Turbine Engine ◽  
Nucleation And Growth ◽  
Smooth Specimen ◽  
Growth Phases ◽  
Adequate Treatment ◽  
Turbine Engine ◽  
Crack Nucleation And Growth

The empirical models commonly used for probabilistic life prediction do not provide adequate treatment of the physical parameters that characterize fatigue damage development. For these models, probabilistic treatment is limited to statistical analysis of strain-life regression fit parameters. In this paper, a model is proposed for life prediction that is based on separate nucleation and growth phases of total fatigue life. The model was calibrated using existing smooth specimen strain-life data, and it has been validated for other geometries. Crack nucleation scatter is estimated based on the variability associated with smooth specimen and fatigue crack growth data, including the influences of correlation among crack nucleation and growth phases. The influences of crack nucleation and growth variability on life and probability of fracture are illustrated for a representative gas turbine engine disk geometry.

Three-dimensional simulation of fretting crack nucleation and growth

2012 ◽  
Vol 96 ◽  
pp. 447-460 ◽  
Author(s):  
B.J. Carter ◽  
E.C. Schenck ◽  
P.A. Wawrzynek ◽  
A.R. Ingraffea ◽  
K.W. Barlow
Keyword(s):  
Crack Nucleation ◽  
Three Dimensional ◽  
Nucleation And Growth ◽  
Dimensional Simulation ◽  
Crack Nucleation And Growth

scholarly journals Multi-platforms approach for plasma proteomics: complementarity of Olink PEA technology to mass spectrometry-based protein profiling

2020 ◽  
Author(s):  
Agnese Petrera ◽  
Christine von Toerne ◽  
Jennifer Behler ◽  
Cornelia Huth ◽  
Barbara Thorand ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Plasma Proteins ◽  
Biomarker Discovery ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Living Organism ◽  
Protein Profiling ◽  
German Population ◽  
Plasma Proteome ◽  
Broad Dynamic Range

AbstractThe plasma proteome is the ultimate target for biomarker discovery. It stores an endless amount of information on the pathophysiological status of a living organism, which is however still difficult to comprehensively access. The high structural complexity of the plasma proteome can be addressed by either a system-wide and unbiased tool such as mass spectrometry (LC-MS/MS) or a highly sensitive targeted immunoassay such as the Proximity Extension Assays (PEA). In order to address relevant differences and important shared characteristics, we tested the performance of LC-MS/MS in data-dependent and -independent acquisition modes and PEA Olink to measure circulating plasma proteins in 173 human plasma samples from a Southern German population-based cohort. We demonstrated the measurement of more than 300 proteins with both LC-MS/MS approaches applied, mainly including high abundance plasma proteins. By the use of the PEA technology, we measured 728 plasma proteins, covering a broad dynamic range with high sensitivity down to pg/ml concentrations. In a next step, we quantified 35 overlapping proteins with all three analytical platforms, verifying the reproducibility of data distributions, measurement correlation and gender-based differential expression. Our work highlights the limitations and the advantages of both, targeted and untargeted approaches, and prove their complementary strengths. We demonstrated a significant gain in proteome coverage depth and subsequent biological insight by platforms combination – a promising approach for future biomarker and mechanistic studies.

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