29 research outputs found
Temperature Correction in Optical Enzymatic Assays Using Thermochromic Liquid Crystals
Many point of care devices use enzymatic assays to quantify the analyte of interest. Enzyme efficiency can be strongly temperature dependent. Therefore, it is important to correct for temperature effects during the analysis of experimental results. This disclosure describes techniques to correct for temperature effects in enzymatic assaying by using thermochromic liquid crystals in parallel with the enzymatic assay to track real time temperature variation at the assay location. Temperature can thus be tracked at the precise assay location, rather than at some nearby point. By thus directly and empirically measuring temperature at the location that matters, assumptions about the distribution of temperature can be eliminated. Accurate knowledge of the temperature at the exact point of assay is thus obtained, improving accuracy in situations where relatively small variations in temperature can cause significant variations in experimental results
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Yucca Mountain Waste Package Closure System
The current disposal path for high-level waste is to place the material into secure waste packages that are inserted into a repository. The Idaho National Laboratory has been tasked with the development, design, and demonstration of the waste package closure system for the repository project. The closure system design includes welding three lids and a purge port cap, four methods of nondestructive examination, and evacuation and backfill of the waste package, all performed in a remote environment. A demonstration of the closure system will be performed with a full-scale waste package
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Exome Sequencing Identifies Rare Variants in Multiple Genes in Atrioventricular Septal Defect
Purpose The genetic etiology of atrioventricular septal defect (AVSD) is unknown in 40% cases. Conventional sequencing and arrays have identified the etiology in only a minority of non-syndromic individuals with AVSD. Methods: Whole exome sequencing was performed in 81 unrelated probands with AVSD to identify potentially causal variants in a comprehensive set of 112 genes with strong biological relevance to AVSD. Results: A significant enrichment of rare and rare/damaging variants was identified in the gene set, compared with controls (odds ratio 1.52, 95% confidence interval 1.35–1.71, p = 4.8 x 10-11). The enrichment was specific to AVSD probands compared with a non-AVSD cohort with tetralogy of Fallot (odds ratio 2.25, 95% confidence interval 1.84-2.76, p = 2.2 x 10-16). Six genes (NIPBL, CHD7, CEP152, BMPR1a, ZFPM2 and MDM4) were enriched for rare variants in AVSD compared to controls, including three syndrome-associated genes (NIPBL, CHD7, CEP152). The findings were confirmed in a replication cohort of 81 AVSD probands. Conclusion: Mutations in genes with strong biological relevance to AVSD, including syndrome-associated genes, can contribute to AVSD even in those with isolated heart disease. The identification of a gene set associated with AVSD will facilitate targeted genetic screening in this cohort
Random coil negative control reproduces the discrepancy between scattering and FRET measurements of denatured protein dimensions.
Effects of crowding on the stability of a surface-tethered biopolymer: an experimental study of folding in a highly crowded regime.
Experimental Measurement of Surface Charge Effects on the Stability of a Surface-Bound Biopolymer.
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An Integrated Optical Sensor for GMAW Feedback Control
The integrated optical sensor (IOS) is a multifunction feedback control sensor for arc welding, that is computer automated and independent of significant operator interaction. It is based on three major off-the-shelf'' components: a charged coupled device (CCD) camera, a diode laser, and a processing computer. The sensor head is compact and lightweight to avoid interference with weld head mobility, hardened to survive the harsh operating environment, and free of specialized cooling and power requirements. The sensor is positioned behind the GMAW torch and measures weld pool position and width, standoff distance, and postweld centerline cooling rate. Weld pool position and width are used in a feedback loop, by the weld controller, to track the weld pool relative to the weld joint, thus allowing compensation for such phenomena as arc blow. Sensor stand off distance is used in a feedback loop to control the contact tip to base metal distance during the welding process. Cooling rate information is used to infer the final metallurgical state of the weld bead and heat affected zone, thereby providing a means of controlling post weld mechanical properties
The Effect of Magnesium on the Thermodynamics of Nucleic Acid Tertiary Contact Formation
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Effects of Crowding on the Stability of a Surface-Tethered Biopolymer: An Experimental Study of Folding in a Highly Crowded Regime
The high packing densities and fixed
geometries with which biomolecules
can be attached to macroscopic surfaces suggest that crowding effects
may be particularly significant under these often densely packed conditions.
Exploring this question experimentally, we report here the effects
of crowding on the stability of a simple, surface-attached DNA stem-loop.
We find that crowding by densely packed, folded biomolecules destabilizes
our test-bed biomolecule by ∼2 kJ/mol relative to the dilute
(noninteracting) regime, an effect that presumably occurs due to steric
and electrostatic repulsion arising from compact neighbors. Crowding
by a dense brush of unfolded biomolecules, in contrast, enhances its
stability by ∼6 kJ/mol, presumably due to excluded volume and
electrostatic effects that reduce the entropy of the unfolded state.
Finally, crowding by like copies of the same biomolecule produces
a significantly broader unfolding transition, likely because, under
these circumstances, the stabilizing effects of crowding by unfolded
molecules increase (and the destabilizing effects of neighboring folded
molecules decrease) as more and more neighbors unfold. The crowding
of surface-attached biomolecules may thus be a richer, more complex
phenomenon than that seen in homogeneous solution