Relationship between resist related outgassing and witness sample contamination in the NXE outgas qualification using electrons and EUV

2013 ◽  
Author(s):  
I. Pollentier ◽  
R. Lokasani ◽  
R. Gronheid ◽  
S. Hill ◽  
C. Tarrio ◽  
...  
Keyword(s):  
Sample Contamination ◽  
Witness Sample

scholarly journals Sensitive detection of DNA contamination in tumor samples via microhaplotypes

2020 ◽  
Author(s):  
Brett Whitty ◽  
John F. Thompson
Keyword(s):  
Sequence Data ◽  
Accurate Determination ◽  
Sensitive Detection ◽  
European Ancestry ◽  
Somatic Variation ◽  
Dna Mixtures ◽  
Accurate Identification ◽  
Sample Contamination ◽  
Dna Contamination ◽  
Low Levels

AbstractBackgroundLow levels of sample contamination can have disastrous effects on the accurate identification of somatic variation in tumor samples. Detection of sample contamination in DNA is generally based on observation of low frequency variants that suggest more than a single source of DNA is present. This strategy works with standard DNA samples but is especially problematic in solid tumor FFPE samples because there can be huge variations in allele frequency (AF) due to massive copy number changes arising from large gains and losses across the genome. The tremendously variable allele frequencies make detection of contamination challenging. A method not based on individual AF is needed for accurate determination of whether a sample is contaminated and to what degree.MethodsWe used microhaplotypes to determine whether sample contamination is present. Microhaplotypes are sets of variants on the same sequencing read that can be unambiguously phased. Instead of measuring AF, the number and frequency of microhaplotypes is determined. Contamination detection becomes based on fundamental genomic properties, linkage disequilibrium (LD) and the diploid nature of human DNA, rather than variant frequencies. We optimized microhaplotype content based on 164 single nucleotide variant sets located in genes already sequenced within a cancer panel. Thus, contamination detection uses existing sequence data and does not require sequencing of any extraneous regions. The content is chosen based on LD data from the 1000 Genomes Project to be ancestry agnostic, providing the same sensitivity for contamination detection with samples from individuals of African, East Asian, and European ancestry.ResultsDetection of contamination at 1% and below is possible using this design. The methods described here can also be extended to other DNA mixtures such as forensic and non-invasive prenatal testing samples where DNA mixes of 1% or less can be similarly detected.ConclusionsThe microhaplotype method allows sensitive detection of DNA contamination in FFPE tumor samples. These methods provide a foundation for examining DNA mixtures in a variety of contexts. With the appropriate panels and high sequencing depth, low levels of secondary DNA can be detected and this can be valuable in a variety of applications.

scholarly journals Air pollution: smog and fog in the large cities of Ukraine.

2017 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Rostyslav Sipakov
Keyword(s):  
Mathematical Model ◽  
Air Pollution ◽  
Chemical Kinetics ◽  
Gaseous Pollutants ◽  
Scattering Process ◽  
Large Cities ◽  
Sample Contamination ◽  
Factors Of Influence ◽  
Main Factors ◽  
Harmful Substances

The main factors of air pollution in large cities in Ukraine are described in the article and the main factors of smog have been analyzed on the example of Kyiv in the period January - February 2017. For the analysis of sample contamination points in Kyiv, we used a mathematical model of the spread of solid and gaseous pollutants with the main factors of influence on the scattering process of contaminants in the air: heat, turbulence, chemical kinetics, etc. As a result of the simulation it was confirmed that the smog in Kyiv and surroundings was formed as a result of anticyclone and air pollution by harmful substances, soot and etc.

scholarly journals Photometry and Spectroscopy of i-drop Galaxies: Possible Detection of A Proto-cluster at z=6

2006 ◽  
Vol 2 (S235) ◽  
pp. 406-407
Author(s):  
Kazuaki Ota
Keyword(s):  
Local Density ◽  
The Other ◽  
Line Of Sight ◽  
Sample Contamination ◽  
Density Excess

AbstractWe discovered 30 candidate galaxies are clustering in a small ~200 Mpc2 region at z = 6 with 5σ local density excess in a wide 876 arcmin2 field. Four of them were spectroscopically identified as z = 5.9–6.0 Lyα emitters (~34 Mpc in line-of-sight). This structure is comparable to z = 4.8 and 5.7 galaxy proto-clusters previously found. Since the other candidates are likely to be real galaxies due to low sample contamination, the overdensity can be a z~6 proto-cluster.

scholarly journals Isotope-Ratio and Background Corrections for Accelerator Mass Spectrometry Radiocarbon Measurements

Radiocarbon ◽  
1990 ◽  
Vol 32 (2) ◽  
pp. 135-142 ◽  
Author(s):  
D J Donahue ◽  
T W Linick ◽  
A J T Jull
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometer ◽  
Accelerator Mass Spectrometry ◽  
Isotope Ratio ◽  
Isotope Ratios ◽  
Sample Contamination ◽  
Accelerator Mass Spectrometer

We present here the method we use to convert to radiocarbon ages (14C/13C) ratios measured in the Arizona Accelerator Mass Spectrometer facility. We describe the procedures we use to convert sample and standard isotope ratios to values appropriate for calculation of radiocarbon ages. We also discuss, in some detail, corrections to account for sample contamination.

scholarly journals Assessing the Effect of Laboratory Environment on Sample Contamination for I-129 Accelerator Mass Spectrometry

2020 ◽  
Vol 36 (5) ◽  
pp. 631-636
Author(s):  
Masumi MATSUMURA ◽  
Kimikazu SASA ◽  
Tetsuya MATSUNAKA ◽  
Keisuke SUEKI ◽  
Tsutomu TAKAHASHI ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Laboratory Environment ◽  
Sample Contamination
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